diff options
Diffstat (limited to 'pkg/sentry')
317 files changed, 8606 insertions, 3530 deletions
diff --git a/pkg/sentry/arch/BUILD b/pkg/sentry/arch/BUILD index 901e0f320..4af4d6e84 100644 --- a/pkg/sentry/arch/BUILD +++ b/pkg/sentry/arch/BUILD @@ -22,6 +22,7 @@ go_library( "signal_info.go", "signal_stack.go", "stack.go", + "stack_unsafe.go", "syscalls_amd64.go", "syscalls_arm64.go", ], @@ -33,11 +34,12 @@ go_library( "//pkg/context", "//pkg/cpuid", "//pkg/log", + "//pkg/marshal", + "//pkg/marshal/primitive", "//pkg/sentry/limits", "//pkg/sync", "//pkg/syserror", "//pkg/usermem", - "//tools/go_marshal/marshal", ], ) diff --git a/pkg/sentry/arch/arch.go b/pkg/sentry/arch/arch.go index a903d031c..d75d665ae 100644 --- a/pkg/sentry/arch/arch.go +++ b/pkg/sentry/arch/arch.go @@ -23,6 +23,7 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/cpuid" "gvisor.dev/gvisor/pkg/log" + "gvisor.dev/gvisor/pkg/marshal" "gvisor.dev/gvisor/pkg/sentry/limits" "gvisor.dev/gvisor/pkg/usermem" ) @@ -72,12 +73,12 @@ type Context interface { // with return values of varying sizes (for example ARCH_GETFS). This // is a simple utility function to convert to the native size in these // cases, and then we can CopyOut. - Native(val uintptr) interface{} + Native(val uintptr) marshal.Marshallable // Value converts a native type back to a generic value. // Once a value has been converted to native via the above call -- it // can be converted back here. - Value(val interface{}) uintptr + Value(val marshal.Marshallable) uintptr // Width returns the number of bytes for a native value. Width() uint @@ -205,7 +206,7 @@ type Context interface { // equivalent of arch_ptrace(): // PtracePeekUser implements ptrace(PTRACE_PEEKUSR). - PtracePeekUser(addr uintptr) (interface{}, error) + PtracePeekUser(addr uintptr) (marshal.Marshallable, error) // PtracePokeUser implements ptrace(PTRACE_POKEUSR). PtracePokeUser(addr, data uintptr) error diff --git a/pkg/sentry/arch/arch_amd64.go b/pkg/sentry/arch/arch_amd64.go index 1c3e3c14c..c7d3a206d 100644 --- a/pkg/sentry/arch/arch_amd64.go +++ b/pkg/sentry/arch/arch_amd64.go @@ -23,6 +23,8 @@ import ( "syscall" "gvisor.dev/gvisor/pkg/cpuid" + "gvisor.dev/gvisor/pkg/marshal" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/limits" "gvisor.dev/gvisor/pkg/usermem" ) @@ -179,14 +181,14 @@ func (c *context64) SetOldRSeqInterruptedIP(value uintptr) { } // Native returns the native type for the given val. -func (c *context64) Native(val uintptr) interface{} { - v := uint64(val) +func (c *context64) Native(val uintptr) marshal.Marshallable { + v := primitive.Uint64(val) return &v } // Value returns the generic val for the given native type. -func (c *context64) Value(val interface{}) uintptr { - return uintptr(*val.(*uint64)) +func (c *context64) Value(val marshal.Marshallable) uintptr { + return uintptr(*val.(*primitive.Uint64)) } // Width returns the byte width of this architecture. @@ -293,7 +295,7 @@ func (c *context64) PIELoadAddress(l MmapLayout) usermem.Addr { const userStructSize = 928 // PtracePeekUser implements Context.PtracePeekUser. -func (c *context64) PtracePeekUser(addr uintptr) (interface{}, error) { +func (c *context64) PtracePeekUser(addr uintptr) (marshal.Marshallable, error) { if addr&7 != 0 || addr >= userStructSize { return nil, syscall.EIO } diff --git a/pkg/sentry/arch/arch_arm64.go b/pkg/sentry/arch/arch_arm64.go index 550741d8c..680d23a9f 100644 --- a/pkg/sentry/arch/arch_arm64.go +++ b/pkg/sentry/arch/arch_arm64.go @@ -22,6 +22,8 @@ import ( "syscall" "gvisor.dev/gvisor/pkg/cpuid" + "gvisor.dev/gvisor/pkg/marshal" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/limits" "gvisor.dev/gvisor/pkg/usermem" ) @@ -163,14 +165,14 @@ func (c *context64) SetOldRSeqInterruptedIP(value uintptr) { } // Native returns the native type for the given val. -func (c *context64) Native(val uintptr) interface{} { - v := uint64(val) +func (c *context64) Native(val uintptr) marshal.Marshallable { + v := primitive.Uint64(val) return &v } // Value returns the generic val for the given native type. -func (c *context64) Value(val interface{}) uintptr { - return uintptr(*val.(*uint64)) +func (c *context64) Value(val marshal.Marshallable) uintptr { + return uintptr(*val.(*primitive.Uint64)) } // Width returns the byte width of this architecture. @@ -274,7 +276,7 @@ func (c *context64) PIELoadAddress(l MmapLayout) usermem.Addr { } // PtracePeekUser implements Context.PtracePeekUser. -func (c *context64) PtracePeekUser(addr uintptr) (interface{}, error) { +func (c *context64) PtracePeekUser(addr uintptr) (marshal.Marshallable, error) { // TODO(gvisor.dev/issue/1239): Full ptrace supporting for Arm64. return c.Native(0), nil } diff --git a/pkg/sentry/arch/signal_act.go b/pkg/sentry/arch/signal_act.go index 32173aa20..d3e2324a8 100644 --- a/pkg/sentry/arch/signal_act.go +++ b/pkg/sentry/arch/signal_act.go @@ -14,7 +14,7 @@ package arch -import "gvisor.dev/gvisor/tools/go_marshal/marshal" +import "gvisor.dev/gvisor/pkg/marshal" // Special values for SignalAct.Handler. const ( diff --git a/pkg/sentry/arch/signal_amd64.go b/pkg/sentry/arch/signal_amd64.go index 6fb756f0e..72e07a988 100644 --- a/pkg/sentry/arch/signal_amd64.go +++ b/pkg/sentry/arch/signal_amd64.go @@ -17,17 +17,19 @@ package arch import ( - "encoding/binary" "math" "syscall" "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/log" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/usermem" ) // SignalContext64 is equivalent to struct sigcontext, the type passed as the // second argument to signal handlers set by signal(2). +// +// +marshal type SignalContext64 struct { R8 uint64 R9 uint64 @@ -68,6 +70,8 @@ const ( ) // UContext64 is equivalent to ucontext_t on 64-bit x86. +// +// +marshal type UContext64 struct { Flags uint64 Link uint64 @@ -172,12 +176,7 @@ func (c *context64) SignalSetup(st *Stack, act *SignalAct, info *SignalInfo, alt // "... the value (%rsp+8) is always a multiple of 16 (...) when // control is transferred to the function entry point." - AMD64 ABI - ucSize := binary.Size(uc) - if ucSize < 0 { - // This can only happen if we've screwed up the definition of - // UContext64. - panic("can't get size of UContext64") - } + ucSize := uc.SizeBytes() // st.Arch.Width() is for the restorer address. sizeof(siginfo) == 128. frameSize := int(st.Arch.Width()) + ucSize + 128 frameBottom := (sp-usermem.Addr(frameSize)) & ^usermem.Addr(15) - 8 @@ -195,18 +194,18 @@ func (c *context64) SignalSetup(st *Stack, act *SignalAct, info *SignalInfo, alt info.FixSignalCodeForUser() // Set up the stack frame. - infoAddr, err := st.Push(info) - if err != nil { + if _, err := info.CopyOut(st, StackBottomMagic); err != nil { return err } - ucAddr, err := st.Push(uc) - if err != nil { + infoAddr := st.Bottom + if _, err := uc.CopyOut(st, StackBottomMagic); err != nil { return err } + ucAddr := st.Bottom if act.HasRestorer() { // Push the restorer return address. // Note that this doesn't need to be popped. - if _, err := st.Push(usermem.Addr(act.Restorer)); err != nil { + if _, err := primitive.CopyUint64Out(st, StackBottomMagic, act.Restorer); err != nil { return err } } else { @@ -240,11 +239,11 @@ func (c *context64) SignalSetup(st *Stack, act *SignalAct, info *SignalInfo, alt func (c *context64) SignalRestore(st *Stack, rt bool) (linux.SignalSet, SignalStack, error) { // Copy out the stack frame. var uc UContext64 - if _, err := st.Pop(&uc); err != nil { + if _, err := uc.CopyIn(st, StackBottomMagic); err != nil { return 0, SignalStack{}, err } var info SignalInfo - if _, err := st.Pop(&info); err != nil { + if _, err := info.CopyIn(st, StackBottomMagic); err != nil { return 0, SignalStack{}, err } diff --git a/pkg/sentry/arch/signal_arm64.go b/pkg/sentry/arch/signal_arm64.go index 642c79dda..7fde5d34e 100644 --- a/pkg/sentry/arch/signal_arm64.go +++ b/pkg/sentry/arch/signal_arm64.go @@ -12,10 +12,11 @@ // See the License for the specific language governing permissions and // limitations under the License. +// +build arm64 + package arch import ( - "encoding/binary" "syscall" "gvisor.dev/gvisor/pkg/abi/linux" @@ -25,6 +26,8 @@ import ( // SignalContext64 is equivalent to struct sigcontext, the type passed as the // second argument to signal handlers set by signal(2). +// +// +marshal type SignalContext64 struct { FaultAddr uint64 Regs [31]uint64 @@ -36,6 +39,7 @@ type SignalContext64 struct { Reserved [3568]uint8 } +// +marshal type aarch64Ctx struct { Magic uint32 Size uint32 @@ -43,6 +47,8 @@ type aarch64Ctx struct { // FpsimdContext is equivalent to struct fpsimd_context on arm64 // (arch/arm64/include/uapi/asm/sigcontext.h). +// +// +marshal type FpsimdContext struct { Head aarch64Ctx Fpsr uint32 @@ -51,13 +57,15 @@ type FpsimdContext struct { } // UContext64 is equivalent to ucontext on arm64(arch/arm64/include/uapi/asm/ucontext.h). +// +// +marshal type UContext64 struct { Flags uint64 Link uint64 Stack SignalStack Sigset linux.SignalSet // glibc uses a 1024-bit sigset_t - _pad [(1024 - 64) / 8]byte + _pad [120]byte // (1024 - 64) / 8 = 120 // sigcontext must be aligned to 16-byte _pad2 [8]byte // last for future expansion @@ -94,11 +102,7 @@ func (c *context64) SignalSetup(st *Stack, act *SignalAct, info *SignalInfo, alt }, Sigset: sigset, } - - ucSize := binary.Size(uc) - if ucSize < 0 { - panic("can't get size of UContext64") - } + ucSize := uc.SizeBytes() // frameSize = ucSize + sizeof(siginfo). // sizeof(siginfo) == 128. @@ -119,14 +123,14 @@ func (c *context64) SignalSetup(st *Stack, act *SignalAct, info *SignalInfo, alt info.FixSignalCodeForUser() // Set up the stack frame. - infoAddr, err := st.Push(info) - if err != nil { + if _, err := info.CopyOut(st, StackBottomMagic); err != nil { return err } - ucAddr, err := st.Push(uc) - if err != nil { + infoAddr := st.Bottom + if _, err := uc.CopyOut(st, StackBottomMagic); err != nil { return err } + ucAddr := st.Bottom // Set up registers. c.Regs.Sp = uint64(st.Bottom) @@ -147,11 +151,11 @@ func (c *context64) SignalSetup(st *Stack, act *SignalAct, info *SignalInfo, alt func (c *context64) SignalRestore(st *Stack, rt bool) (linux.SignalSet, SignalStack, error) { // Copy out the stack frame. var uc UContext64 - if _, err := st.Pop(&uc); err != nil { + if _, err := uc.CopyIn(st, StackBottomMagic); err != nil { return 0, SignalStack{}, err } var info SignalInfo - if _, err := st.Pop(&info); err != nil { + if _, err := info.CopyIn(st, StackBottomMagic); err != nil { return 0, SignalStack{}, err } diff --git a/pkg/sentry/arch/signal_stack.go b/pkg/sentry/arch/signal_stack.go index 0fa738a1d..a1eae98f9 100644 --- a/pkg/sentry/arch/signal_stack.go +++ b/pkg/sentry/arch/signal_stack.go @@ -17,8 +17,8 @@ package arch import ( + "gvisor.dev/gvisor/pkg/marshal" "gvisor.dev/gvisor/pkg/usermem" - "gvisor.dev/gvisor/tools/go_marshal/marshal" ) const ( diff --git a/pkg/sentry/arch/stack.go b/pkg/sentry/arch/stack.go index 1108fa0bd..5f06c751d 100644 --- a/pkg/sentry/arch/stack.go +++ b/pkg/sentry/arch/stack.go @@ -15,14 +15,16 @@ package arch import ( - "encoding/binary" - "fmt" - "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/usermem" ) -// Stack is a simple wrapper around a usermem.IO and an address. +// Stack is a simple wrapper around a usermem.IO and an address. Stack +// implements marshal.CopyContext, and marshallable values can be pushed or +// popped from the stack through the marshal.Marshallable interface. +// +// Stack is not thread-safe. type Stack struct { // Our arch info. // We use this for automatic Native conversion of usermem.Addrs during @@ -34,105 +36,60 @@ type Stack struct { // Our current stack bottom. Bottom usermem.Addr -} -// Push pushes the given values on to the stack. -// -// (This method supports Addrs and treats them as native types.) -func (s *Stack) Push(vals ...interface{}) (usermem.Addr, error) { - for _, v := range vals { - - // We convert some types to well-known serializable quanities. - var norm interface{} - - // For array types, we will automatically add an appropriate - // terminal value. This is done simply to make the interface - // easier to use. - var term interface{} - - switch v.(type) { - case string: - norm = []byte(v.(string)) - term = byte(0) - case []int8, []uint8: - norm = v - term = byte(0) - case []int16, []uint16: - norm = v - term = uint16(0) - case []int32, []uint32: - norm = v - term = uint32(0) - case []int64, []uint64: - norm = v - term = uint64(0) - case []usermem.Addr: - // Special case: simply push recursively. - _, err := s.Push(s.Arch.Native(uintptr(0))) - if err != nil { - return 0, err - } - varr := v.([]usermem.Addr) - for i := len(varr) - 1; i >= 0; i-- { - _, err := s.Push(varr[i]) - if err != nil { - return 0, err - } - } - continue - case usermem.Addr: - norm = s.Arch.Native(uintptr(v.(usermem.Addr))) - default: - norm = v - } + // Scratch buffer used for marshalling to avoid having to repeatedly + // allocate scratch memory. + scratchBuf []byte +} - if term != nil { - _, err := s.Push(term) - if err != nil { - return 0, err - } - } +// scratchBufLen is the default length of Stack.scratchBuf. The +// largest structs the stack regularly serializes are arch.SignalInfo +// and arch.UContext64. We'll set the default size as the larger of +// the two, arch.UContext64. +var scratchBufLen = (*UContext64)(nil).SizeBytes() - c := binary.Size(norm) - if c < 0 { - return 0, fmt.Errorf("bad binary.Size for %T", v) - } - n, err := usermem.CopyObjectOut(context.Background(), s.IO, s.Bottom-usermem.Addr(c), norm, usermem.IOOpts{}) - if err != nil || c != n { - return 0, err - } +// CopyScratchBuffer implements marshal.CopyContext.CopyScratchBuffer. +func (s *Stack) CopyScratchBuffer(size int) []byte { + if len(s.scratchBuf) < size { + s.scratchBuf = make([]byte, size) + } + return s.scratchBuf[:size] +} +// StackBottomMagic is the special address callers must past to all stack +// marshalling operations to cause the src/dst address to be computed based on +// the current end of the stack. +const StackBottomMagic = ^usermem.Addr(0) // usermem.Addr(-1) + +// CopyOutBytes implements marshal.CopyContext.CopyOutBytes. CopyOutBytes +// computes an appropriate address based on the current end of the +// stack. Callers use the sentinel address StackBottomMagic to marshal methods +// to indicate this. +func (s *Stack) CopyOutBytes(sentinel usermem.Addr, b []byte) (int, error) { + if sentinel != StackBottomMagic { + panic("Attempted to copy out to stack with absolute address") + } + c := len(b) + n, err := s.IO.CopyOut(context.Background(), s.Bottom-usermem.Addr(c), b, usermem.IOOpts{}) + if err == nil && n == c { s.Bottom -= usermem.Addr(n) } - - return s.Bottom, nil + return n, err } -// Pop pops the given values off the stack. -// -// (This method supports Addrs and treats them as native types.) -func (s *Stack) Pop(vals ...interface{}) (usermem.Addr, error) { - for _, v := range vals { - - vaddr, isVaddr := v.(*usermem.Addr) - - var n int - var err error - if isVaddr { - value := s.Arch.Native(uintptr(0)) - n, err = usermem.CopyObjectIn(context.Background(), s.IO, s.Bottom, value, usermem.IOOpts{}) - *vaddr = usermem.Addr(s.Arch.Value(value)) - } else { - n, err = usermem.CopyObjectIn(context.Background(), s.IO, s.Bottom, v, usermem.IOOpts{}) - } - if err != nil { - return 0, err - } - +// CopyInBytes implements marshal.CopyContext.CopyInBytes. CopyInBytes computes +// an appropriate address based on the current end of the stack. Callers must +// use the sentinel address StackBottomMagic to marshal methods to indicate +// this. +func (s *Stack) CopyInBytes(sentinel usermem.Addr, b []byte) (int, error) { + if sentinel != StackBottomMagic { + panic("Attempted to copy in from stack with absolute address") + } + n, err := s.IO.CopyIn(context.Background(), s.Bottom, b, usermem.IOOpts{}) + if err == nil { s.Bottom += usermem.Addr(n) } - - return s.Bottom, nil + return n, err } // Align aligns the stack to the given offset. @@ -142,6 +99,22 @@ func (s *Stack) Align(offset int) { } } +// PushNullTerminatedByteSlice writes bs to the stack, followed by an extra null +// byte at the end. On error, the contents of the stack and the bottom cursor +// are undefined. +func (s *Stack) PushNullTerminatedByteSlice(bs []byte) (int, error) { + // Note: Stack grows up, so write the terminal null byte first. + nNull, err := primitive.CopyUint8Out(s, StackBottomMagic, 0) + if err != nil { + return 0, err + } + n, err := primitive.CopyByteSliceOut(s, StackBottomMagic, bs) + if err != nil { + return 0, err + } + return n + nNull, nil +} + // StackLayout describes the location of the arguments and environment on the // stack. type StackLayout struct { @@ -177,11 +150,10 @@ func (s *Stack) Load(args []string, env []string, aux Auxv) (StackLayout, error) l.EnvvEnd = s.Bottom envAddrs := make([]usermem.Addr, len(env)) for i := len(env) - 1; i >= 0; i-- { - addr, err := s.Push(env[i]) - if err != nil { + if _, err := s.PushNullTerminatedByteSlice([]byte(env[i])); err != nil { return StackLayout{}, err } - envAddrs[i] = addr + envAddrs[i] = s.Bottom } l.EnvvStart = s.Bottom @@ -189,11 +161,10 @@ func (s *Stack) Load(args []string, env []string, aux Auxv) (StackLayout, error) l.ArgvEnd = s.Bottom argAddrs := make([]usermem.Addr, len(args)) for i := len(args) - 1; i >= 0; i-- { - addr, err := s.Push(args[i]) - if err != nil { + if _, err := s.PushNullTerminatedByteSlice([]byte(args[i])); err != nil { return StackLayout{}, err } - argAddrs[i] = addr + argAddrs[i] = s.Bottom } l.ArgvStart = s.Bottom @@ -222,26 +193,26 @@ func (s *Stack) Load(args []string, env []string, aux Auxv) (StackLayout, error) auxv = append(auxv, usermem.Addr(a.Key), a.Value) } auxv = append(auxv, usermem.Addr(0)) - _, err := s.Push(auxv) + _, err := s.pushAddrSliceAndTerminator(auxv) if err != nil { return StackLayout{}, err } // Push environment. - _, err = s.Push(envAddrs) + _, err = s.pushAddrSliceAndTerminator(envAddrs) if err != nil { return StackLayout{}, err } // Push args. - _, err = s.Push(argAddrs) + _, err = s.pushAddrSliceAndTerminator(argAddrs) if err != nil { return StackLayout{}, err } // Push arg count. - _, err = s.Push(usermem.Addr(len(args))) - if err != nil { + lenP := s.Arch.Native(uintptr(len(args))) + if _, err = lenP.CopyOut(s, StackBottomMagic); err != nil { return StackLayout{}, err } diff --git a/pkg/sentry/arch/stack_unsafe.go b/pkg/sentry/arch/stack_unsafe.go new file mode 100644 index 000000000..a90d297ee --- /dev/null +++ b/pkg/sentry/arch/stack_unsafe.go @@ -0,0 +1,69 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package arch + +import ( + "reflect" + "runtime" + "unsafe" + + "gvisor.dev/gvisor/pkg/marshal/primitive" + "gvisor.dev/gvisor/pkg/usermem" +) + +// pushAddrSliceAndTerminator copies a slices of addresses to the stack, and +// also pushes an extra null address element at the end of the slice. +// +// Internally, we unsafely transmute the slice type from the arch-dependent +// []usermem.Addr type, to a slice of fixed-sized ints so that we can pass it to +// go-marshal. +// +// On error, the contents of the stack and the bottom cursor are undefined. +func (s *Stack) pushAddrSliceAndTerminator(src []usermem.Addr) (int, error) { + // Note: Stack grows upwards, so push the terminator first. + srcHdr := (*reflect.SliceHeader)(unsafe.Pointer(&src)) + switch s.Arch.Width() { + case 8: + nNull, err := primitive.CopyUint64Out(s, StackBottomMagic, 0) + if err != nil { + return 0, err + } + var dst []uint64 + dstHdr := (*reflect.SliceHeader)(unsafe.Pointer(&dst)) + dstHdr.Data = srcHdr.Data + dstHdr.Len = srcHdr.Len + dstHdr.Cap = srcHdr.Cap + n, err := primitive.CopyUint64SliceOut(s, StackBottomMagic, dst) + // Ensures src doesn't get GCed until we're done using it through dst. + runtime.KeepAlive(src) + return n + nNull, err + case 4: + nNull, err := primitive.CopyUint32Out(s, StackBottomMagic, 0) + if err != nil { + return 0, err + } + var dst []uint32 + dstHdr := (*reflect.SliceHeader)(unsafe.Pointer(&dst)) + dstHdr.Data = srcHdr.Data + dstHdr.Len = srcHdr.Len + dstHdr.Cap = srcHdr.Cap + n, err := primitive.CopyUint32SliceOut(s, StackBottomMagic, dst) + // Ensure src doesn't get GCed until we're done using it through dst. + runtime.KeepAlive(src) + return n + nNull, err + default: + panic("Unsupported arch width") + } +} diff --git a/pkg/sentry/control/BUILD b/pkg/sentry/control/BUILD index 2c5d14be5..deaf5fa23 100644 --- a/pkg/sentry/control/BUILD +++ b/pkg/sentry/control/BUILD @@ -35,7 +35,6 @@ go_library( "//pkg/sync", "//pkg/tcpip/link/sniffer", "//pkg/urpc", - "@org_golang_x_sys//unix:go_default_library", ], ) diff --git a/pkg/sentry/control/proc.go b/pkg/sentry/control/proc.go index dfa936563..668f47802 100644 --- a/pkg/sentry/control/proc.go +++ b/pkg/sentry/control/proc.go @@ -23,8 +23,8 @@ import ( "text/tabwriter" "time" - "golang.org/x/sys/unix" "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/fd" "gvisor.dev/gvisor/pkg/sentry/fdimport" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/fs/host" @@ -203,27 +203,17 @@ func (proc *Proc) execAsync(args *ExecArgs) (*kernel.ThreadGroup, kernel.ThreadI } initArgs.Filename = resolved - fds := make([]int, len(args.FilePayload.Files)) - for i, file := range args.FilePayload.Files { - if kernel.VFS2Enabled { - // Need to dup to remove ownership from os.File. - dup, err := unix.Dup(int(file.Fd())) - if err != nil { - return nil, 0, nil, nil, fmt.Errorf("duplicating payload files: %w", err) - } - fds[i] = dup - } else { - // VFS1 dups the file on import. - fds[i] = int(file.Fd()) - } + fds, err := fd.NewFromFiles(args.Files) + if err != nil { + return nil, 0, nil, nil, fmt.Errorf("duplicating payload files: %w", err) } + defer func() { + for _, fd := range fds { + _ = fd.Close() + } + }() ttyFile, ttyFileVFS2, err := fdimport.Import(ctx, fdTable, args.StdioIsPty, fds) if err != nil { - if kernel.VFS2Enabled { - for _, fd := range fds { - unix.Close(fd) - } - } return nil, 0, nil, nil, err } diff --git a/pkg/sentry/devices/memdev/BUILD b/pkg/sentry/devices/memdev/BUILD index abe58f818..4c8604d58 100644 --- a/pkg/sentry/devices/memdev/BUILD +++ b/pkg/sentry/devices/memdev/BUILD @@ -18,9 +18,10 @@ go_library( "//pkg/rand", "//pkg/safemem", "//pkg/sentry/fsimpl/devtmpfs", + "//pkg/sentry/fsimpl/tmpfs", + "//pkg/sentry/kernel", + "//pkg/sentry/kernel/auth", "//pkg/sentry/memmap", - "//pkg/sentry/mm", - "//pkg/sentry/pgalloc", "//pkg/sentry/vfs", "//pkg/syserror", "//pkg/usermem", diff --git a/pkg/sentry/devices/memdev/full.go b/pkg/sentry/devices/memdev/full.go index 511179e31..fece3e762 100644 --- a/pkg/sentry/devices/memdev/full.go +++ b/pkg/sentry/devices/memdev/full.go @@ -24,6 +24,8 @@ import ( const fullDevMinor = 7 // fullDevice implements vfs.Device for /dev/full. +// +// +stateify savable type fullDevice struct{} // Open implements vfs.Device.Open. @@ -38,6 +40,8 @@ func (fullDevice) Open(ctx context.Context, mnt *vfs.Mount, vfsd *vfs.Dentry, op } // fullFD implements vfs.FileDescriptionImpl for /dev/full. +// +// +stateify savable type fullFD struct { vfsfd vfs.FileDescription vfs.FileDescriptionDefaultImpl diff --git a/pkg/sentry/devices/memdev/null.go b/pkg/sentry/devices/memdev/null.go index 4918dbeeb..ff5837747 100644 --- a/pkg/sentry/devices/memdev/null.go +++ b/pkg/sentry/devices/memdev/null.go @@ -25,6 +25,8 @@ import ( const nullDevMinor = 3 // nullDevice implements vfs.Device for /dev/null. +// +// +stateify savable type nullDevice struct{} // Open implements vfs.Device.Open. @@ -39,6 +41,8 @@ func (nullDevice) Open(ctx context.Context, mnt *vfs.Mount, vfsd *vfs.Dentry, op } // nullFD implements vfs.FileDescriptionImpl for /dev/null. +// +// +stateify savable type nullFD struct { vfsfd vfs.FileDescription vfs.FileDescriptionDefaultImpl diff --git a/pkg/sentry/devices/memdev/random.go b/pkg/sentry/devices/memdev/random.go index 5e7fe0280..ac943e3ba 100644 --- a/pkg/sentry/devices/memdev/random.go +++ b/pkg/sentry/devices/memdev/random.go @@ -30,6 +30,8 @@ const ( ) // randomDevice implements vfs.Device for /dev/random and /dev/urandom. +// +// +stateify savable type randomDevice struct{} // Open implements vfs.Device.Open. @@ -44,6 +46,8 @@ func (randomDevice) Open(ctx context.Context, mnt *vfs.Mount, vfsd *vfs.Dentry, } // randomFD implements vfs.FileDescriptionImpl for /dev/random. +// +// +stateify savable type randomFD struct { vfsfd vfs.FileDescription vfs.FileDescriptionDefaultImpl diff --git a/pkg/sentry/devices/memdev/zero.go b/pkg/sentry/devices/memdev/zero.go index 2e631a252..1929e41cd 100644 --- a/pkg/sentry/devices/memdev/zero.go +++ b/pkg/sentry/devices/memdev/zero.go @@ -16,9 +16,10 @@ package memdev import ( "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/sentry/fsimpl/tmpfs" + "gvisor.dev/gvisor/pkg/sentry/kernel" + "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/sentry/memmap" - "gvisor.dev/gvisor/pkg/sentry/mm" - "gvisor.dev/gvisor/pkg/sentry/pgalloc" "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/usermem" ) @@ -26,6 +27,8 @@ import ( const zeroDevMinor = 5 // zeroDevice implements vfs.Device for /dev/zero. +// +// +stateify savable type zeroDevice struct{} // Open implements vfs.Device.Open. @@ -40,6 +43,8 @@ func (zeroDevice) Open(ctx context.Context, mnt *vfs.Mount, vfsd *vfs.Dentry, op } // zeroFD implements vfs.FileDescriptionImpl for /dev/zero. +// +// +stateify savable type zeroFD struct { vfsfd vfs.FileDescription vfs.FileDescriptionDefaultImpl @@ -79,11 +84,22 @@ func (fd *zeroFD) Seek(ctx context.Context, offset int64, whence int32) (int64, // ConfigureMMap implements vfs.FileDescriptionImpl.ConfigureMMap. func (fd *zeroFD) ConfigureMMap(ctx context.Context, opts *memmap.MMapOpts) error { - m, err := mm.NewSharedAnonMappable(opts.Length, pgalloc.MemoryFileProviderFromContext(ctx)) + if opts.Private || !opts.MaxPerms.Write { + // This mapping will never permit writing to the "underlying file" (in + // Linux terms, it isn't VM_SHARED), so implement it as an anonymous + // mapping, but back it with fd; this is what Linux does, and is + // actually application-visible because the resulting VMA will show up + // in /proc/[pid]/maps with fd.vfsfd.VirtualDentry()'s path rather than + // "/dev/zero (deleted)". + opts.Offset = 0 + opts.MappingIdentity = &fd.vfsfd + opts.MappingIdentity.IncRef() + return nil + } + tmpfsFD, err := tmpfs.NewZeroFile(ctx, auth.CredentialsFromContext(ctx), kernel.KernelFromContext(ctx).ShmMount(), opts.Length) if err != nil { return err } - opts.MappingIdentity = m - opts.Mappable = m - return nil + defer tmpfsFD.DecRef(ctx) + return tmpfsFD.ConfigureMMap(ctx, opts) } diff --git a/pkg/sentry/devices/ttydev/ttydev.go b/pkg/sentry/devices/ttydev/ttydev.go index 664e54498..a287c65ca 100644 --- a/pkg/sentry/devices/ttydev/ttydev.go +++ b/pkg/sentry/devices/ttydev/ttydev.go @@ -30,6 +30,8 @@ const ( ) // ttyDevice implements vfs.Device for /dev/tty. +// +// +stateify savable type ttyDevice struct{} // Open implements vfs.Device.Open. diff --git a/pkg/sentry/fdimport/BUILD b/pkg/sentry/fdimport/BUILD index 5e41ceb4e..6b4f8b0ed 100644 --- a/pkg/sentry/fdimport/BUILD +++ b/pkg/sentry/fdimport/BUILD @@ -10,6 +10,7 @@ go_library( visibility = ["//pkg/sentry:internal"], deps = [ "//pkg/context", + "//pkg/fd", "//pkg/sentry/fs", "//pkg/sentry/fs/host", "//pkg/sentry/fsimpl/host", diff --git a/pkg/sentry/fdimport/fdimport.go b/pkg/sentry/fdimport/fdimport.go index 1b7cb94c0..314661475 100644 --- a/pkg/sentry/fdimport/fdimport.go +++ b/pkg/sentry/fdimport/fdimport.go @@ -18,6 +18,7 @@ import ( "fmt" "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/fd" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/fs/host" hostvfs2 "gvisor.dev/gvisor/pkg/sentry/fsimpl/host" @@ -27,8 +28,9 @@ import ( // Import imports a slice of FDs into the given FDTable. If console is true, // sets up TTY for the first 3 FDs in the slice representing stdin, stdout, -// stderr. Upon success, Import takes ownership of all FDs. -func Import(ctx context.Context, fdTable *kernel.FDTable, console bool, fds []int) (*host.TTYFileOperations, *hostvfs2.TTYFileDescription, error) { +// stderr. Used FDs are either closed or released. It's safe for the caller to +// close any remaining files upon return. +func Import(ctx context.Context, fdTable *kernel.FDTable, console bool, fds []*fd.FD) (*host.TTYFileOperations, *hostvfs2.TTYFileDescription, error) { if kernel.VFS2Enabled { ttyFile, err := importVFS2(ctx, fdTable, console, fds) return nil, ttyFile, err @@ -37,7 +39,7 @@ func Import(ctx context.Context, fdTable *kernel.FDTable, console bool, fds []in return ttyFile, nil, err } -func importFS(ctx context.Context, fdTable *kernel.FDTable, console bool, fds []int) (*host.TTYFileOperations, error) { +func importFS(ctx context.Context, fdTable *kernel.FDTable, console bool, fds []*fd.FD) (*host.TTYFileOperations, error) { var ttyFile *fs.File for appFD, hostFD := range fds { var appFile *fs.File @@ -46,11 +48,12 @@ func importFS(ctx context.Context, fdTable *kernel.FDTable, console bool, fds [] // Import the file as a host TTY file. if ttyFile == nil { var err error - appFile, err = host.ImportFile(ctx, hostFD, true /* isTTY */) + appFile, err = host.ImportFile(ctx, hostFD.FD(), true /* isTTY */) if err != nil { return nil, err } defer appFile.DecRef(ctx) + _ = hostFD.Close() // FD is dup'd i ImportFile. // Remember this in the TTY file, as we will // use it for the other stdio FDs. @@ -65,11 +68,12 @@ func importFS(ctx context.Context, fdTable *kernel.FDTable, console bool, fds [] } else { // Import the file as a regular host file. var err error - appFile, err = host.ImportFile(ctx, hostFD, false /* isTTY */) + appFile, err = host.ImportFile(ctx, hostFD.FD(), false /* isTTY */) if err != nil { return nil, err } defer appFile.DecRef(ctx) + _ = hostFD.Close() // FD is dup'd i ImportFile. } // Add the file to the FD map. @@ -84,7 +88,7 @@ func importFS(ctx context.Context, fdTable *kernel.FDTable, console bool, fds [] return ttyFile.FileOperations.(*host.TTYFileOperations), nil } -func importVFS2(ctx context.Context, fdTable *kernel.FDTable, console bool, stdioFDs []int) (*hostvfs2.TTYFileDescription, error) { +func importVFS2(ctx context.Context, fdTable *kernel.FDTable, console bool, stdioFDs []*fd.FD) (*hostvfs2.TTYFileDescription, error) { k := kernel.KernelFromContext(ctx) if k == nil { return nil, fmt.Errorf("cannot find kernel from context") @@ -98,11 +102,12 @@ func importVFS2(ctx context.Context, fdTable *kernel.FDTable, console bool, stdi // Import the file as a host TTY file. if ttyFile == nil { var err error - appFile, err = hostvfs2.ImportFD(ctx, k.HostMount(), hostFD, true /* isTTY */) + appFile, err = hostvfs2.ImportFD(ctx, k.HostMount(), hostFD.FD(), true /* isTTY */) if err != nil { return nil, err } defer appFile.DecRef(ctx) + hostFD.Release() // FD is transfered to host FD. // Remember this in the TTY file, as we will use it for the other stdio // FDs. @@ -115,11 +120,12 @@ func importVFS2(ctx context.Context, fdTable *kernel.FDTable, console bool, stdi } } else { var err error - appFile, err = hostvfs2.ImportFD(ctx, k.HostMount(), hostFD, false /* isTTY */) + appFile, err = hostvfs2.ImportFD(ctx, k.HostMount(), hostFD.FD(), false /* isTTY */) if err != nil { return nil, err } defer appFile.DecRef(ctx) + hostFD.Release() // FD is transfered to host FD. } if err := fdTable.NewFDAtVFS2(ctx, int32(appFD), appFile, kernel.FDFlags{}); err != nil { diff --git a/pkg/sentry/fs/g3doc/fuse.md b/pkg/sentry/fs/g3doc/fuse.md index 2ca84dd74..05e043583 100644 --- a/pkg/sentry/fs/g3doc/fuse.md +++ b/pkg/sentry/fs/g3doc/fuse.md @@ -79,7 +79,7 @@ ops can be implemented in parallel. - Implement `/dev/fuse` - a character device used to establish an FD for communication between the sentry and the server daemon. -- Implement basic FUSE ops like `FUSE_INIT`, `FUSE_DESTROY`. +- Implement basic FUSE ops like `FUSE_INIT`. #### Read-only mount with basic file operations @@ -95,6 +95,103 @@ ops can be implemented in parallel. - Implement the remaining FUSE ops and decide if we can omit rarely used operations like ioctl. +### Design Details + +#### Lifecycle for a FUSE Request + +- User invokes a syscall +- Sentry prepares corresponding request + - If FUSE device is available + - Write the request in binary + - If FUSE device is full + - Kernel task blocked until available +- Sentry notifies the readers of fuse device that it's ready for read +- FUSE daemon reads the request and processes it +- Sentry waits until a reply is written to the FUSE device + - but returns directly for async requests +- FUSE daemon writes to the fuse device +- Sentry processes the reply + - For sync requests, unblock blocked kernel task + - For async requests, execute pre-specified callback if any +- Sentry returns the syscall to the user + +#### Channels and Queues for Requests in Different Stages + +`connection.initializedChan` + +- a channel that the requests issued before connection initialization blocks + on. + +`fd.queue` + +- a queue of requests that haven’t been read by the FUSE daemon yet. + +`fd.completions` + +- a map of the requests that have been prepared but not yet received a + response, including the ones on the `fd.queue`. + +`fd.waitQueue` + +- a queue of waiters that is waiting for the fuse device fd to be available, + such as the FUSE daemon. + +`fd.fullQueueCh` + +- a channel that the kernel task will be blocked on when the fd is not + available. + +#### Basic I/O Implementation + +Currently we have implemented basic functionalities of read and write for our +FUSE. We describe the design and ways to improve it here: + +##### Basic FUSE Read + +The vfs2 expects implementations of `vfs.FileDescriptionImpl.Read()` and +`vfs.FileDescriptionImpl.PRead()`. When a syscall is made, it will eventually +reach our implementation of those interface functions located at +`pkg/sentry/fsimpl/fuse/regular_file.go` for regular files. + +After validation checks of the input, sentry sends `FUSE_READ` requests to the +FUSE daemon. The FUSE daemon returns data after the `fuse_out_header` as the +responses. For the first version, we create a copy in kernel memory of those +data. They are represented as a byte slice in the marshalled struct. This +happens as a common process for all the FUSE responses at this moment at +`pkg/sentry/fsimpl/fuse/dev.go:writeLocked()`. We then directly copy from this +intermediate buffer to the input buffer provided by the read syscall. + +There is an extra requirement for FUSE: When mounting the FUSE fs, the mounter +or the FUSE daemon can specify a `max_read` or a `max_pages` parameter. They are +the upperbound of the bytes to read in each `FUSE_READ` request. We implemented +the code to handle the fragmented reads. + +To improve the performance: ideally we should have buffer cache to copy those +data from the responses of FUSE daemon into, as is also the design of several +other existing file system implementations for sentry, instead of a single-use +temporary buffer. Directly mapping the memory of one process to another could +also boost the performance, but to keep them isolated, we did not choose to do +so. + +##### Basic FUSE Write + +The vfs2 invokes implementations of `vfs.FileDescriptionImpl.Write()` and +`vfs.FileDescriptionImpl.PWrite()` on the regular file descriptor of FUSE when a +user makes write(2) and pwrite(2) syscall. + +For valid writes, sentry sends the bytes to write after a `FUSE_WRITE` header +(can be regarded as a request with 2 payloads) to the FUSE daemon. For the first +version, we allocate a buffer inside kernel memory to store the bytes from the +user, and copy directly from that buffer to the memory of FUSE daemon. This +happens at `pkg/sentry/fsimpl/fuse/dev.go:readLocked()` + +The parameters `max_write` and `max_pages` restrict the number of bytes in one +`FUSE_WRITE`. There are code handling fragmented writes in current +implementation. + +To have better performance: the extra copy created to store the bytes to write +can be replaced by the buffer cache as well. + # Appendix ## FUSE Protocol diff --git a/pkg/sentry/fs/host/BUILD b/pkg/sentry/fs/host/BUILD index 42a6c41c2..1368014c4 100644 --- a/pkg/sentry/fs/host/BUILD +++ b/pkg/sentry/fs/host/BUILD @@ -32,6 +32,7 @@ go_library( "//pkg/fdnotifier", "//pkg/iovec", "//pkg/log", + "//pkg/marshal/primitive", "//pkg/refs", "//pkg/safemem", "//pkg/secio", @@ -55,7 +56,6 @@ go_library( "//pkg/unet", "//pkg/usermem", "//pkg/waiter", - "//tools/go_marshal/primitive", ], ) diff --git a/pkg/sentry/fs/host/socket_unsafe.go b/pkg/sentry/fs/host/socket_unsafe.go index 5d4f312cf..c8231e0aa 100644 --- a/pkg/sentry/fs/host/socket_unsafe.go +++ b/pkg/sentry/fs/host/socket_unsafe.go @@ -65,10 +65,10 @@ func fdReadVec(fd int, bufs [][]byte, control []byte, peek bool, maxlen int64) ( controlTrunc = msg.Flags&syscall.MSG_CTRUNC == syscall.MSG_CTRUNC if n > length { - return length, n, msg.Controllen, controlTrunc, err + return length, n, msg.Controllen, controlTrunc, nil } - return n, n, msg.Controllen, controlTrunc, err + return n, n, msg.Controllen, controlTrunc, nil } // fdWriteVec sends from bufs to fd. diff --git a/pkg/sentry/fs/host/tty.go b/pkg/sentry/fs/host/tty.go index 67a807f9d..1183727ab 100644 --- a/pkg/sentry/fs/host/tty.go +++ b/pkg/sentry/fs/host/tty.go @@ -17,6 +17,7 @@ package host import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/kernel" @@ -24,7 +25,6 @@ import ( "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/usermem" - "gvisor.dev/gvisor/tools/go_marshal/primitive" ) // LINT.IfChange @@ -54,7 +54,7 @@ type TTYFileOperations struct { func newTTYFile(ctx context.Context, dirent *fs.Dirent, flags fs.FileFlags, iops *inodeOperations) *fs.File { return fs.NewFile(ctx, dirent, flags, &TTYFileOperations{ fileOperations: fileOperations{iops: iops}, - termios: linux.DefaultSlaveTermios, + termios: linux.DefaultReplicaTermios, }) } diff --git a/pkg/sentry/fs/inode.go b/pkg/sentry/fs/inode.go index b79cd9877..004910453 100644 --- a/pkg/sentry/fs/inode.go +++ b/pkg/sentry/fs/inode.go @@ -270,7 +270,7 @@ func (i *Inode) GetXattr(ctx context.Context, name string, size uint64) (string, // SetXattr calls i.InodeOperations.SetXattr with i as the Inode. func (i *Inode) SetXattr(ctx context.Context, d *Dirent, name, value string, flags uint32) error { if i.overlay != nil { - return overlaySetxattr(ctx, i.overlay, d, name, value, flags) + return overlaySetXattr(ctx, i.overlay, d, name, value, flags) } return i.InodeOperations.SetXattr(ctx, i, name, value, flags) } diff --git a/pkg/sentry/fs/inode_overlay.go b/pkg/sentry/fs/inode_overlay.go index dc2e353d9..b16ab08ba 100644 --- a/pkg/sentry/fs/inode_overlay.go +++ b/pkg/sentry/fs/inode_overlay.go @@ -16,7 +16,6 @@ package fs import ( "fmt" - "strings" "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" @@ -539,7 +538,7 @@ func overlayGetXattr(ctx context.Context, o *overlayEntry, name string, size uin // Don't forward the value of the extended attribute if it would // unexpectedly change the behavior of a wrapping overlay layer. - if strings.HasPrefix(XattrOverlayPrefix, name) { + if isXattrOverlay(name) { return "", syserror.ENODATA } @@ -553,9 +552,9 @@ func overlayGetXattr(ctx context.Context, o *overlayEntry, name string, size uin return s, err } -func overlaySetxattr(ctx context.Context, o *overlayEntry, d *Dirent, name, value string, flags uint32) error { +func overlaySetXattr(ctx context.Context, o *overlayEntry, d *Dirent, name, value string, flags uint32) error { // Don't allow changes to overlay xattrs through a setxattr syscall. - if strings.HasPrefix(XattrOverlayPrefix, name) { + if isXattrOverlay(name) { return syserror.EPERM } @@ -578,7 +577,7 @@ func overlayListXattr(ctx context.Context, o *overlayEntry, size uint64) (map[st for name := range names { // Same as overlayGetXattr, we shouldn't forward along // overlay attributes. - if strings.HasPrefix(XattrOverlayPrefix, name) { + if isXattrOverlay(name) { delete(names, name) } } @@ -587,7 +586,7 @@ func overlayListXattr(ctx context.Context, o *overlayEntry, size uint64) (map[st func overlayRemoveXattr(ctx context.Context, o *overlayEntry, d *Dirent, name string) error { // Don't allow changes to overlay xattrs through a removexattr syscall. - if strings.HasPrefix(XattrOverlayPrefix, name) { + if isXattrOverlay(name) { return syserror.EPERM } diff --git a/pkg/sentry/fs/proc/BUILD b/pkg/sentry/fs/proc/BUILD index 77c2c5c0e..b8b2281a8 100644 --- a/pkg/sentry/fs/proc/BUILD +++ b/pkg/sentry/fs/proc/BUILD @@ -50,6 +50,7 @@ go_library( "//pkg/sync", "//pkg/syserror", "//pkg/tcpip/header", + "//pkg/tcpip/network/ipv4", "//pkg/usermem", "//pkg/waiter", ], diff --git a/pkg/sentry/fs/proc/sys_net.go b/pkg/sentry/fs/proc/sys_net.go index 8615b60f0..e555672ad 100644 --- a/pkg/sentry/fs/proc/sys_net.go +++ b/pkg/sentry/fs/proc/sys_net.go @@ -26,6 +26,7 @@ import ( "gvisor.dev/gvisor/pkg/sentry/fs/ramfs" "gvisor.dev/gvisor/pkg/sentry/inet" "gvisor.dev/gvisor/pkg/sync" + "gvisor.dev/gvisor/pkg/tcpip/network/ipv4" "gvisor.dev/gvisor/pkg/usermem" "gvisor.dev/gvisor/pkg/waiter" ) @@ -54,7 +55,7 @@ type tcpMemInode struct { // size stores the tcp buffer size during save, and sets the buffer // size in netstack in restore. We must save/restore this here, since - // netstack itself is stateless. + // a netstack instance is created on restore. size inet.TCPBufferSize // mu protects against concurrent reads/writes to files based on this @@ -258,6 +259,9 @@ func (f *tcpSackFile) Write(ctx context.Context, _ *fs.File, src usermem.IOSeque if src.NumBytes() == 0 { return 0, nil } + + // Only consider size of one memory page for input for performance reasons. + // We are only reading if it's zero or not anyway. src = src.TakeFirst(usermem.PageSize - 1) var v int32 @@ -383,11 +387,125 @@ func (p *proc) newSysNetCore(ctx context.Context, msrc *fs.MountSource, s inet.S return newProcInode(ctx, d, msrc, fs.SpecialDirectory, nil) } +// ipForwarding implements fs.InodeOperations. +// +// ipForwarding is used to enable/disable packet forwarding of netstack. +// +// +stateify savable +type ipForwarding struct { + fsutil.SimpleFileInode + + stack inet.Stack `state:"wait"` + + // enabled stores the IPv4 forwarding state on save. + // We must save/restore this here, since a netstack instance + // is created on restore. + enabled *bool +} + +func newIPForwardingInode(ctx context.Context, msrc *fs.MountSource, s inet.Stack) *fs.Inode { + ipf := &ipForwarding{ + SimpleFileInode: *fsutil.NewSimpleFileInode(ctx, fs.RootOwner, fs.FilePermsFromMode(0444), linux.PROC_SUPER_MAGIC), + stack: s, + } + sattr := fs.StableAttr{ + DeviceID: device.ProcDevice.DeviceID(), + InodeID: device.ProcDevice.NextIno(), + BlockSize: usermem.PageSize, + Type: fs.SpecialFile, + } + return fs.NewInode(ctx, ipf, msrc, sattr) +} + +// Truncate implements fs.InodeOperations.Truncate. Truncate is called when +// O_TRUNC is specified for any kind of existing Dirent but is not called via +// (f)truncate for proc files. +func (*ipForwarding) Truncate(context.Context, *fs.Inode, int64) error { + return nil +} + +// +stateify savable +type ipForwardingFile struct { + fsutil.FileGenericSeek `state:"nosave"` + fsutil.FileNoIoctl `state:"nosave"` + fsutil.FileNoMMap `state:"nosave"` + fsutil.FileNoSplice `state:"nosave"` + fsutil.FileNoopFlush `state:"nosave"` + fsutil.FileNoopFsync `state:"nosave"` + fsutil.FileNoopRelease `state:"nosave"` + fsutil.FileNotDirReaddir `state:"nosave"` + fsutil.FileUseInodeUnstableAttr `state:"nosave"` + waiter.AlwaysReady `state:"nosave"` + + ipf *ipForwarding + + stack inet.Stack `state:"wait"` +} + +// GetFile implements fs.InodeOperations.GetFile. +func (ipf *ipForwarding) GetFile(ctx context.Context, dirent *fs.Dirent, flags fs.FileFlags) (*fs.File, error) { + flags.Pread = true + flags.Pwrite = true + return fs.NewFile(ctx, dirent, flags, &ipForwardingFile{ + stack: ipf.stack, + ipf: ipf, + }), nil +} + +// Read implements fs.FileOperations.Read. +func (f *ipForwardingFile) Read(ctx context.Context, _ *fs.File, dst usermem.IOSequence, offset int64) (int64, error) { + if offset != 0 { + return 0, io.EOF + } + + if f.ipf.enabled == nil { + enabled := f.stack.Forwarding(ipv4.ProtocolNumber) + f.ipf.enabled = &enabled + } + + val := "0\n" + if *f.ipf.enabled { + // Technically, this is not quite compatible with Linux. Linux + // stores these as an integer, so if you write "2" into + // ip_forward, you should get 2 back. + val = "1\n" + } + n, err := dst.CopyOut(ctx, []byte(val)) + return int64(n), err +} + +// Write implements fs.FileOperations.Write. +// +// Offset is ignored, multiple writes are not supported. +func (f *ipForwardingFile) Write(ctx context.Context, _ *fs.File, src usermem.IOSequence, offset int64) (int64, error) { + if src.NumBytes() == 0 { + return 0, nil + } + + // Only consider size of one memory page for input for performance reasons. + // We are only reading if it's zero or not anyway. + src = src.TakeFirst(usermem.PageSize - 1) + + var v int32 + n, err := usermem.CopyInt32StringInVec(ctx, src.IO, src.Addrs, &v, src.Opts) + if err != nil { + return n, err + } + if f.ipf.enabled == nil { + f.ipf.enabled = new(bool) + } + *f.ipf.enabled = v != 0 + return n, f.stack.SetForwarding(ipv4.ProtocolNumber, *f.ipf.enabled) +} + func (p *proc) newSysNetIPv4Dir(ctx context.Context, msrc *fs.MountSource, s inet.Stack) *fs.Inode { contents := map[string]*fs.Inode{ // Add tcp_sack. "tcp_sack": newTCPSackInode(ctx, msrc, s), + // Add ip_forward. + "ip_forward": newIPForwardingInode(ctx, msrc, s), + // The following files are simple stubs until they are // implemented in netstack, most of these files are // configuration related. We use the value closest to the diff --git a/pkg/sentry/fs/proc/sys_net_state.go b/pkg/sentry/fs/proc/sys_net_state.go index 6eba709c6..4cb4741af 100644 --- a/pkg/sentry/fs/proc/sys_net_state.go +++ b/pkg/sentry/fs/proc/sys_net_state.go @@ -14,7 +14,11 @@ package proc -import "fmt" +import ( + "fmt" + + "gvisor.dev/gvisor/pkg/tcpip/network/ipv4" +) // beforeSave is invoked by stateify. func (t *tcpMemInode) beforeSave() { @@ -40,3 +44,12 @@ func (s *tcpSack) afterLoad() { } } } + +// afterLoad is invoked by stateify. +func (ipf *ipForwarding) afterLoad() { + if ipf.enabled != nil { + if err := ipf.stack.SetForwarding(ipv4.ProtocolNumber, *ipf.enabled); err != nil { + panic(fmt.Sprintf("failed to set IPv4 forwarding [%v]: %v", *ipf.enabled, err)) + } + } +} diff --git a/pkg/sentry/fs/proc/sys_net_test.go b/pkg/sentry/fs/proc/sys_net_test.go index 355e83d47..6ef5738e7 100644 --- a/pkg/sentry/fs/proc/sys_net_test.go +++ b/pkg/sentry/fs/proc/sys_net_test.go @@ -123,3 +123,76 @@ func TestConfigureRecvBufferSize(t *testing.T) { } } } + +// TestIPForwarding tests the implementation of +// /proc/sys/net/ipv4/ip_forwarding +func TestIPForwarding(t *testing.T) { + ctx := context.Background() + s := inet.NewTestStack() + + var cases = []struct { + comment string + initial bool + str string + final bool + }{ + { + comment: `Forwarding is disabled; write 1 and enable forwarding`, + initial: false, + str: "1", + final: true, + }, + { + comment: `Forwarding is disabled; write 0 and disable forwarding`, + initial: false, + str: "0", + final: false, + }, + { + comment: `Forwarding is enabled; write 1 and enable forwarding`, + initial: true, + str: "1", + final: true, + }, + { + comment: `Forwarding is enabled; write 0 and disable forwarding`, + initial: true, + str: "0", + final: false, + }, + { + comment: `Forwarding is disabled; write 2404 and enable forwarding`, + initial: false, + str: "2404", + final: true, + }, + { + comment: `Forwarding is enabled; write 2404 and enable forwarding`, + initial: true, + str: "2404", + final: true, + }, + } + for _, c := range cases { + t.Run(c.comment, func(t *testing.T) { + s.IPForwarding = c.initial + ipf := &ipForwarding{stack: s} + file := &ipForwardingFile{ + stack: s, + ipf: ipf, + } + + // Write the values. + src := usermem.BytesIOSequence([]byte(c.str)) + if n, err := file.Write(ctx, nil, src, 0); n != int64(len(c.str)) || err != nil { + t.Errorf("file.Write(ctx, nil, %q, 0) = (%d, %v); want (%d, nil)", c.str, n, err, len(c.str)) + } + + // Read the values from the stack and check them. + if got, want := s.IPForwarding, c.final; got != want { + t.Errorf("s.IPForwarding incorrect; got: %v, want: %v", got, want) + } + + }) + } +} diff --git a/pkg/sentry/fs/proc/task.go b/pkg/sentry/fs/proc/task.go index 9cf7f2a62..22d658acf 100644 --- a/pkg/sentry/fs/proc/task.go +++ b/pkg/sentry/fs/proc/task.go @@ -84,6 +84,7 @@ func (p *proc) newTaskDir(t *kernel.Task, msrc *fs.MountSource, isThreadGroup bo "auxv": newAuxvec(t, msrc), "cmdline": newExecArgInode(t, msrc, cmdlineExecArg), "comm": newComm(t, msrc), + "cwd": newCwd(t, msrc), "environ": newExecArgInode(t, msrc, environExecArg), "exe": newExe(t, msrc), "fd": newFdDir(t, msrc), @@ -300,6 +301,49 @@ func (e *exe) Readlink(ctx context.Context, inode *fs.Inode) (string, error) { return exec.PathnameWithDeleted(ctx), nil } +// cwd is an fs.InodeOperations symlink for the /proc/PID/cwd file. +// +// +stateify savable +type cwd struct { + ramfs.Symlink + + t *kernel.Task +} + +func newCwd(t *kernel.Task, msrc *fs.MountSource) *fs.Inode { + cwdSymlink := &cwd{ + Symlink: *ramfs.NewSymlink(t, fs.RootOwner, ""), + t: t, + } + return newProcInode(t, cwdSymlink, msrc, fs.Symlink, t) +} + +// Readlink implements fs.InodeOperations. +func (e *cwd) Readlink(ctx context.Context, inode *fs.Inode) (string, error) { + if !kernel.ContextCanTrace(ctx, e.t, false) { + return "", syserror.EACCES + } + if err := checkTaskState(e.t); err != nil { + return "", err + } + cwd := e.t.FSContext().WorkingDirectory() + if cwd == nil { + // It could have raced with process deletion. + return "", syserror.ESRCH + } + defer cwd.DecRef(ctx) + + root := fs.RootFromContext(ctx) + if root == nil { + // It could have raced with process deletion. + return "", syserror.ESRCH + } + defer root.DecRef(ctx) + + name, _ := cwd.FullName(root) + return name, nil +} + // namespaceSymlink represents a symlink in the namespacefs, such as the files // in /proc/<pid>/ns. // @@ -604,7 +648,7 @@ func (s *statusData) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ( var vss, rss, data uint64 s.t.WithMuLocked(func(t *kernel.Task) { if fdTable := t.FDTable(); fdTable != nil { - fds = fdTable.Size() + fds = fdTable.CurrentMaxFDs() } if mm := t.MemoryManager(); mm != nil { vss = mm.VirtualMemorySize() diff --git a/pkg/sentry/fs/tty/BUILD b/pkg/sentry/fs/tty/BUILD index 5cb0e0417..e6d0eb359 100644 --- a/pkg/sentry/fs/tty/BUILD +++ b/pkg/sentry/fs/tty/BUILD @@ -10,13 +10,14 @@ go_library( "line_discipline.go", "master.go", "queue.go", - "slave.go", + "replica.go", "terminal.go", ], visibility = ["//pkg/sentry:internal"], deps = [ "//pkg/abi/linux", "//pkg/context", + "//pkg/marshal/primitive", "//pkg/refs", "//pkg/safemem", "//pkg/sentry/arch", diff --git a/pkg/sentry/fs/tty/dir.go b/pkg/sentry/fs/tty/dir.go index 463f6189e..c2da80bc2 100644 --- a/pkg/sentry/fs/tty/dir.go +++ b/pkg/sentry/fs/tty/dir.go @@ -37,14 +37,14 @@ import ( // This indirectly manages all terminals within the mount. // // New Terminals are created by masterInodeOperations.GetFile, which registers -// the slave Inode in the this directory for discovery via Lookup/Readdir. The -// slave inode is unregistered when the master file is Released, as the slave +// the replica Inode in the this directory for discovery via Lookup/Readdir. The +// replica inode is unregistered when the master file is Released, as the replica // is no longer discoverable at that point. // // References on the underlying Terminal are held by masterFileOperations and -// slaveInodeOperations. +// replicaInodeOperations. // -// masterInodeOperations and slaveInodeOperations hold a pointer to +// masterInodeOperations and replicaInodeOperations hold a pointer to // dirInodeOperations, which is reference counted by the refcount their // corresponding Dirents hold on their parent (this directory). // @@ -76,16 +76,16 @@ type dirInodeOperations struct { // master is the master PTY inode. master *fs.Inode - // slaves contains the slave inodes reachable from the directory. + // replicas contains the replica inodes reachable from the directory. // - // A new slave is added by allocateTerminal and is removed by + // A new replica is added by allocateTerminal and is removed by // masterFileOperations.Release. // - // A reference is held on every slave in the map. - slaves map[uint32]*fs.Inode + // A reference is held on every replica in the map. + replicas map[uint32]*fs.Inode // dentryMap is a SortedDentryMap used to implement Readdir containing - // the master and all entries in slaves. + // the master and all entries in replicas. dentryMap *fs.SortedDentryMap // next is the next pty index to use. @@ -101,7 +101,7 @@ func newDir(ctx context.Context, m *fs.MountSource) *fs.Inode { d := &dirInodeOperations{ InodeSimpleAttributes: fsutil.NewInodeSimpleAttributes(ctx, fs.RootOwner, fs.FilePermsFromMode(0555), linux.DEVPTS_SUPER_MAGIC), msrc: m, - slaves: make(map[uint32]*fs.Inode), + replicas: make(map[uint32]*fs.Inode), dentryMap: fs.NewSortedDentryMap(nil), } // Linux devpts uses a default mode of 0000 for ptmx which can be @@ -133,7 +133,7 @@ func (d *dirInodeOperations) Release(ctx context.Context) { defer d.mu.Unlock() d.master.DecRef(ctx) - if len(d.slaves) != 0 { + if len(d.replicas) != 0 { panic(fmt.Sprintf("devpts directory still contains active terminals: %+v", d)) } } @@ -149,14 +149,14 @@ func (d *dirInodeOperations) Lookup(ctx context.Context, dir *fs.Inode, name str return fs.NewDirent(ctx, d.master, name), nil } - // Slave number? + // Replica number? n, err := strconv.ParseUint(name, 10, 32) if err != nil { // Not found. return nil, syserror.ENOENT } - s, ok := d.slaves[uint32(n)] + s, ok := d.replicas[uint32(n)] if !ok { return nil, syserror.ENOENT } @@ -236,7 +236,7 @@ func (d *dirInodeOperations) allocateTerminal(ctx context.Context) (*Terminal, e return nil, syserror.ENOMEM } - if _, ok := d.slaves[n]; ok { + if _, ok := d.replicas[n]; ok { panic(fmt.Sprintf("pty index collision; index %d already exists", n)) } @@ -244,19 +244,19 @@ func (d *dirInodeOperations) allocateTerminal(ctx context.Context) (*Terminal, e d.next++ // The reference returned by newTerminal is returned to the caller. - // Take another for the slave inode. + // Take another for the replica inode. t.IncRef() // Create a pts node. The owner is based on the context that opens // ptmx. creds := auth.CredentialsFromContext(ctx) uid, gid := creds.EffectiveKUID, creds.EffectiveKGID - slave := newSlaveInode(ctx, d, t, fs.FileOwner{uid, gid}, fs.FilePermsFromMode(0666)) + replica := newReplicaInode(ctx, d, t, fs.FileOwner{uid, gid}, fs.FilePermsFromMode(0666)) - d.slaves[n] = slave + d.replicas[n] = replica d.dentryMap.Add(strconv.FormatUint(uint64(n), 10), fs.DentAttr{ - Type: slave.StableAttr.Type, - InodeID: slave.StableAttr.InodeID, + Type: replica.StableAttr.Type, + InodeID: replica.StableAttr.InodeID, }) return t, nil @@ -267,18 +267,18 @@ func (d *dirInodeOperations) masterClose(ctx context.Context, t *Terminal) { d.mu.Lock() defer d.mu.Unlock() - // The slave end disappears from the directory when the master end is - // closed, even if the slave end is open elsewhere. + // The replica end disappears from the directory when the master end is + // closed, even if the replica end is open elsewhere. // // N.B. since we're using a backdoor method to remove a directory entry // we won't properly fire inotify events like Linux would. - s, ok := d.slaves[t.n] + s, ok := d.replicas[t.n] if !ok { panic(fmt.Sprintf("Terminal %+v doesn't exist in %+v?", t, d)) } s.DecRef(ctx) - delete(d.slaves, t.n) + delete(d.replicas, t.n) d.dentryMap.Remove(strconv.FormatUint(uint64(t.n), 10)) } diff --git a/pkg/sentry/fs/tty/fs.go b/pkg/sentry/fs/tty/fs.go index 2d4d44bf3..13f4901db 100644 --- a/pkg/sentry/fs/tty/fs.go +++ b/pkg/sentry/fs/tty/fs.go @@ -79,8 +79,8 @@ type superOperations struct{} // // It always returns true, forcing a Lookup for all entries. // -// Slave entries are dropped from dir when their master is closed, so an -// existing slave Dirent in the tree is not sufficient to guarantee that it +// Replica entries are dropped from dir when their master is closed, so an +// existing replica Dirent in the tree is not sufficient to guarantee that it // still exists on the filesystem. func (superOperations) Revalidate(context.Context, string, *fs.Inode, *fs.Inode) bool { return true diff --git a/pkg/sentry/fs/tty/line_discipline.go b/pkg/sentry/fs/tty/line_discipline.go index 2e9dd2d55..b34f4a0eb 100644 --- a/pkg/sentry/fs/tty/line_discipline.go +++ b/pkg/sentry/fs/tty/line_discipline.go @@ -21,6 +21,7 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/sentry/arch" + "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/usermem" @@ -43,7 +44,7 @@ const ( ) // lineDiscipline dictates how input and output are handled between the -// pseudoterminal (pty) master and slave. It can be configured to alter I/O, +// pseudoterminal (pty) master and replica. It can be configured to alter I/O, // modify control characters (e.g. Ctrl-C for SIGINT), etc. The following man // pages are good resources for how to affect the line discipline: // @@ -54,8 +55,8 @@ const ( // // lineDiscipline has a simple structure but supports a multitude of options // (see the above man pages). It consists of two queues of bytes: one from the -// terminal master to slave (the input queue) and one from slave to master (the -// output queue). When bytes are written to one end of the pty, the line +// terminal master to replica (the input queue) and one from replica to master +// (the output queue). When bytes are written to one end of the pty, the line // discipline reads the bytes, modifies them or takes special action if // required, and enqueues them to be read by the other end of the pty: // @@ -64,7 +65,7 @@ const ( // | (inputQueueWrite) +-------------+ (inputQueueRead) | // | | // | v -// masterFD slaveFD +// masterFD replicaFD // ^ | // | | // | output to terminal +--------------+ output from process | @@ -103,8 +104,8 @@ type lineDiscipline struct { // masterWaiter is used to wait on the master end of the TTY. masterWaiter waiter.Queue `state:"zerovalue"` - // slaveWaiter is used to wait on the slave end of the TTY. - slaveWaiter waiter.Queue `state:"zerovalue"` + // replicaWaiter is used to wait on the replica end of the TTY. + replicaWaiter waiter.Queue `state:"zerovalue"` } func newLineDiscipline(termios linux.KernelTermios) *lineDiscipline { @@ -115,27 +116,23 @@ func newLineDiscipline(termios linux.KernelTermios) *lineDiscipline { } // getTermios gets the linux.Termios for the tty. -func (l *lineDiscipline) getTermios(ctx context.Context, io usermem.IO, args arch.SyscallArguments) (uintptr, error) { +func (l *lineDiscipline) getTermios(task *kernel.Task, args arch.SyscallArguments) (uintptr, error) { l.termiosMu.RLock() defer l.termiosMu.RUnlock() // We must copy a Termios struct, not KernelTermios. t := l.termios.ToTermios() - _, err := usermem.CopyObjectOut(ctx, io, args[2].Pointer(), t, usermem.IOOpts{ - AddressSpaceActive: true, - }) + _, err := t.CopyOut(task, args[2].Pointer()) return 0, err } // setTermios sets a linux.Termios for the tty. -func (l *lineDiscipline) setTermios(ctx context.Context, io usermem.IO, args arch.SyscallArguments) (uintptr, error) { +func (l *lineDiscipline) setTermios(task *kernel.Task, args arch.SyscallArguments) (uintptr, error) { l.termiosMu.Lock() defer l.termiosMu.Unlock() oldCanonEnabled := l.termios.LEnabled(linux.ICANON) // We must copy a Termios struct, not KernelTermios. var t linux.Termios - _, err := usermem.CopyObjectIn(ctx, io, args[2].Pointer(), &t, usermem.IOOpts{ - AddressSpaceActive: true, - }) + _, err := t.CopyIn(task, args[2].Pointer()) l.termios.FromTermios(t) // If canonical mode is turned off, move bytes from inQueue's wait @@ -146,27 +143,23 @@ func (l *lineDiscipline) setTermios(ctx context.Context, io usermem.IO, args arc l.inQueue.pushWaitBufLocked(l) l.inQueue.readable = true l.inQueue.mu.Unlock() - l.slaveWaiter.Notify(waiter.EventIn) + l.replicaWaiter.Notify(waiter.EventIn) } return 0, err } -func (l *lineDiscipline) windowSize(ctx context.Context, io usermem.IO, args arch.SyscallArguments) error { +func (l *lineDiscipline) windowSize(t *kernel.Task, args arch.SyscallArguments) error { l.sizeMu.Lock() defer l.sizeMu.Unlock() - _, err := usermem.CopyObjectOut(ctx, io, args[2].Pointer(), l.size, usermem.IOOpts{ - AddressSpaceActive: true, - }) + _, err := l.size.CopyOut(t, args[2].Pointer()) return err } -func (l *lineDiscipline) setWindowSize(ctx context.Context, io usermem.IO, args arch.SyscallArguments) error { +func (l *lineDiscipline) setWindowSize(t *kernel.Task, args arch.SyscallArguments) error { l.sizeMu.Lock() defer l.sizeMu.Unlock() - _, err := usermem.CopyObjectIn(ctx, io, args[2].Pointer(), &l.size, usermem.IOOpts{ - AddressSpaceActive: true, - }) + _, err := l.size.CopyIn(t, args[2].Pointer()) return err } @@ -176,14 +169,14 @@ func (l *lineDiscipline) masterReadiness() waiter.EventMask { return l.inQueue.writeReadiness(&linux.MasterTermios) | l.outQueue.readReadiness(&linux.MasterTermios) } -func (l *lineDiscipline) slaveReadiness() waiter.EventMask { +func (l *lineDiscipline) replicaReadiness() waiter.EventMask { l.termiosMu.RLock() defer l.termiosMu.RUnlock() return l.outQueue.writeReadiness(&l.termios) | l.inQueue.readReadiness(&l.termios) } -func (l *lineDiscipline) inputQueueReadSize(ctx context.Context, io usermem.IO, args arch.SyscallArguments) error { - return l.inQueue.readableSize(ctx, io, args) +func (l *lineDiscipline) inputQueueReadSize(t *kernel.Task, args arch.SyscallArguments) error { + return l.inQueue.readableSize(t, args) } func (l *lineDiscipline) inputQueueRead(ctx context.Context, dst usermem.IOSequence) (int64, error) { @@ -196,7 +189,7 @@ func (l *lineDiscipline) inputQueueRead(ctx context.Context, dst usermem.IOSeque if n > 0 { l.masterWaiter.Notify(waiter.EventOut) if pushed { - l.slaveWaiter.Notify(waiter.EventIn) + l.replicaWaiter.Notify(waiter.EventIn) } return n, nil } @@ -211,14 +204,14 @@ func (l *lineDiscipline) inputQueueWrite(ctx context.Context, src usermem.IOSequ return 0, err } if n > 0 { - l.slaveWaiter.Notify(waiter.EventIn) + l.replicaWaiter.Notify(waiter.EventIn) return n, nil } return 0, syserror.ErrWouldBlock } -func (l *lineDiscipline) outputQueueReadSize(ctx context.Context, io usermem.IO, args arch.SyscallArguments) error { - return l.outQueue.readableSize(ctx, io, args) +func (l *lineDiscipline) outputQueueReadSize(t *kernel.Task, args arch.SyscallArguments) error { + return l.outQueue.readableSize(t, args) } func (l *lineDiscipline) outputQueueRead(ctx context.Context, dst usermem.IOSequence) (int64, error) { @@ -229,7 +222,7 @@ func (l *lineDiscipline) outputQueueRead(ctx context.Context, dst usermem.IOSequ return 0, err } if n > 0 { - l.slaveWaiter.Notify(waiter.EventOut) + l.replicaWaiter.Notify(waiter.EventOut) if pushed { l.masterWaiter.Notify(waiter.EventIn) } diff --git a/pkg/sentry/fs/tty/master.go b/pkg/sentry/fs/tty/master.go index e00746017..b91184b1b 100644 --- a/pkg/sentry/fs/tty/master.go +++ b/pkg/sentry/fs/tty/master.go @@ -17,9 +17,11 @@ package tty import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/fs/fsutil" + "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/unimpl" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/usermem" @@ -152,46 +154,51 @@ func (mf *masterFileOperations) Write(ctx context.Context, _ *fs.File, src userm // Ioctl implements fs.FileOperations.Ioctl. func (mf *masterFileOperations) Ioctl(ctx context.Context, _ *fs.File, io usermem.IO, args arch.SyscallArguments) (uintptr, error) { + t := kernel.TaskFromContext(ctx) + if t == nil { + // ioctl(2) may only be called from a task goroutine. + return 0, syserror.ENOTTY + } + switch cmd := args[1].Uint(); cmd { case linux.FIONREAD: // linux.FIONREAD == linux.TIOCINQ // Get the number of bytes in the output queue read buffer. - return 0, mf.t.ld.outputQueueReadSize(ctx, io, args) + return 0, mf.t.ld.outputQueueReadSize(t, args) case linux.TCGETS: // N.B. TCGETS on the master actually returns the configuration - // of the slave end. - return mf.t.ld.getTermios(ctx, io, args) + // of the replica end. + return mf.t.ld.getTermios(t, args) case linux.TCSETS: // N.B. TCSETS on the master actually affects the configuration - // of the slave end. - return mf.t.ld.setTermios(ctx, io, args) + // of the replica end. + return mf.t.ld.setTermios(t, args) case linux.TCSETSW: // TODO(b/29356795): This should drain the output queue first. - return mf.t.ld.setTermios(ctx, io, args) + return mf.t.ld.setTermios(t, args) case linux.TIOCGPTN: - _, err := usermem.CopyObjectOut(ctx, io, args[2].Pointer(), uint32(mf.t.n), usermem.IOOpts{ - AddressSpaceActive: true, - }) + nP := primitive.Uint32(mf.t.n) + _, err := nP.CopyOut(t, args[2].Pointer()) return 0, err case linux.TIOCSPTLCK: // TODO(b/29356795): Implement pty locking. For now just pretend we do. return 0, nil case linux.TIOCGWINSZ: - return 0, mf.t.ld.windowSize(ctx, io, args) + return 0, mf.t.ld.windowSize(t, args) case linux.TIOCSWINSZ: - return 0, mf.t.ld.setWindowSize(ctx, io, args) + return 0, mf.t.ld.setWindowSize(t, args) case linux.TIOCSCTTY: // Make the given terminal the controlling terminal of the // calling process. - return 0, mf.t.setControllingTTY(ctx, io, args, true /* isMaster */) + return 0, mf.t.setControllingTTY(ctx, args, true /* isMaster */) case linux.TIOCNOTTY: // Release this process's controlling terminal. - return 0, mf.t.releaseControllingTTY(ctx, io, args, true /* isMaster */) + return 0, mf.t.releaseControllingTTY(ctx, args, true /* isMaster */) case linux.TIOCGPGRP: // Get the foreground process group. - return mf.t.foregroundProcessGroup(ctx, io, args, true /* isMaster */) + return mf.t.foregroundProcessGroup(ctx, args, true /* isMaster */) case linux.TIOCSPGRP: // Set the foreground process group. - return mf.t.setForegroundProcessGroup(ctx, io, args, true /* isMaster */) + return mf.t.setForegroundProcessGroup(ctx, args, true /* isMaster */) default: maybeEmitUnimplementedEvent(ctx, cmd) return 0, syserror.ENOTTY diff --git a/pkg/sentry/fs/tty/queue.go b/pkg/sentry/fs/tty/queue.go index c5d7ec717..79975d812 100644 --- a/pkg/sentry/fs/tty/queue.go +++ b/pkg/sentry/fs/tty/queue.go @@ -17,8 +17,10 @@ package tty import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/safemem" "gvisor.dev/gvisor/pkg/sentry/arch" + "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/usermem" @@ -32,7 +34,7 @@ import ( const waitBufMaxBytes = 131072 // queue represents one of the input or output queues between a pty master and -// slave. Bytes written to a queue are added to the read buffer until it is +// replica. Bytes written to a queue are added to the read buffer until it is // full, at which point they are written to the wait buffer. Bytes are // processed (i.e. undergo termios transformations) as they are added to the // read buffer. The read buffer is readable when its length is nonzero and @@ -85,17 +87,15 @@ func (q *queue) writeReadiness(t *linux.KernelTermios) waiter.EventMask { } // readableSize writes the number of readable bytes to userspace. -func (q *queue) readableSize(ctx context.Context, io usermem.IO, args arch.SyscallArguments) error { +func (q *queue) readableSize(t *kernel.Task, args arch.SyscallArguments) error { q.mu.Lock() defer q.mu.Unlock() - var size int32 + size := primitive.Int32(0) if q.readable { - size = int32(len(q.readBuf)) + size = primitive.Int32(len(q.readBuf)) } - _, err := usermem.CopyObjectOut(ctx, io, args[2].Pointer(), size, usermem.IOOpts{ - AddressSpaceActive: true, - }) + _, err := size.CopyOut(t, args[2].Pointer()) return err } diff --git a/pkg/sentry/fs/tty/slave.go b/pkg/sentry/fs/tty/replica.go index 7c7292687..385d230fb 100644 --- a/pkg/sentry/fs/tty/slave.go +++ b/pkg/sentry/fs/tty/replica.go @@ -17,9 +17,11 @@ package tty import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/fs/fsutil" + "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/usermem" "gvisor.dev/gvisor/pkg/waiter" @@ -27,11 +29,11 @@ import ( // LINT.IfChange -// slaveInodeOperations are the fs.InodeOperations for the slave end of the +// replicaInodeOperations are the fs.InodeOperations for the replica end of the // Terminal (pts file). // // +stateify savable -type slaveInodeOperations struct { +type replicaInodeOperations struct { fsutil.SimpleFileInode // d is the containing dir. @@ -41,13 +43,13 @@ type slaveInodeOperations struct { t *Terminal } -var _ fs.InodeOperations = (*slaveInodeOperations)(nil) +var _ fs.InodeOperations = (*replicaInodeOperations)(nil) -// newSlaveInode creates an fs.Inode for the slave end of a terminal. +// newReplicaInode creates an fs.Inode for the replica end of a terminal. // -// newSlaveInode takes ownership of t. -func newSlaveInode(ctx context.Context, d *dirInodeOperations, t *Terminal, owner fs.FileOwner, p fs.FilePermissions) *fs.Inode { - iops := &slaveInodeOperations{ +// newReplicaInode takes ownership of t. +func newReplicaInode(ctx context.Context, d *dirInodeOperations, t *Terminal, owner fs.FileOwner, p fs.FilePermissions) *fs.Inode { + iops := &replicaInodeOperations{ SimpleFileInode: *fsutil.NewSimpleFileInode(ctx, owner, p, linux.DEVPTS_SUPER_MAGIC), d: d, t: t, @@ -64,18 +66,18 @@ func newSlaveInode(ctx context.Context, d *dirInodeOperations, t *Terminal, owne Type: fs.CharacterDevice, // See fs/devpts/inode.c:devpts_fill_super. BlockSize: 1024, - DeviceFileMajor: linux.UNIX98_PTY_SLAVE_MAJOR, + DeviceFileMajor: linux.UNIX98_PTY_REPLICA_MAJOR, DeviceFileMinor: t.n, }) } // Release implements fs.InodeOperations.Release. -func (si *slaveInodeOperations) Release(ctx context.Context) { +func (si *replicaInodeOperations) Release(ctx context.Context) { si.t.DecRef(ctx) } // Truncate implements fs.InodeOperations.Truncate. -func (*slaveInodeOperations) Truncate(context.Context, *fs.Inode, int64) error { +func (*replicaInodeOperations) Truncate(context.Context, *fs.Inode, int64) error { return nil } @@ -83,14 +85,15 @@ func (*slaveInodeOperations) Truncate(context.Context, *fs.Inode, int64) error { // // This may race with destruction of the terminal. If the terminal is gone, it // returns ENOENT. -func (si *slaveInodeOperations) GetFile(ctx context.Context, d *fs.Dirent, flags fs.FileFlags) (*fs.File, error) { - return fs.NewFile(ctx, d, flags, &slaveFileOperations{si: si}), nil +func (si *replicaInodeOperations) GetFile(ctx context.Context, d *fs.Dirent, flags fs.FileFlags) (*fs.File, error) { + return fs.NewFile(ctx, d, flags, &replicaFileOperations{si: si}), nil } -// slaveFileOperations are the fs.FileOperations for the slave end of a terminal. +// replicaFileOperations are the fs.FileOperations for the replica end of a +// terminal. // // +stateify savable -type slaveFileOperations struct { +type replicaFileOperations struct { fsutil.FilePipeSeek `state:"nosave"` fsutil.FileNotDirReaddir `state:"nosave"` fsutil.FileNoFsync `state:"nosave"` @@ -100,79 +103,84 @@ type slaveFileOperations struct { fsutil.FileUseInodeUnstableAttr `state:"nosave"` // si is the inode operations. - si *slaveInodeOperations + si *replicaInodeOperations } -var _ fs.FileOperations = (*slaveFileOperations)(nil) +var _ fs.FileOperations = (*replicaFileOperations)(nil) // Release implements fs.FileOperations.Release. -func (sf *slaveFileOperations) Release(context.Context) { +func (sf *replicaFileOperations) Release(context.Context) { } // EventRegister implements waiter.Waitable.EventRegister. -func (sf *slaveFileOperations) EventRegister(e *waiter.Entry, mask waiter.EventMask) { - sf.si.t.ld.slaveWaiter.EventRegister(e, mask) +func (sf *replicaFileOperations) EventRegister(e *waiter.Entry, mask waiter.EventMask) { + sf.si.t.ld.replicaWaiter.EventRegister(e, mask) } // EventUnregister implements waiter.Waitable.EventUnregister. -func (sf *slaveFileOperations) EventUnregister(e *waiter.Entry) { - sf.si.t.ld.slaveWaiter.EventUnregister(e) +func (sf *replicaFileOperations) EventUnregister(e *waiter.Entry) { + sf.si.t.ld.replicaWaiter.EventUnregister(e) } // Readiness implements waiter.Waitable.Readiness. -func (sf *slaveFileOperations) Readiness(mask waiter.EventMask) waiter.EventMask { - return sf.si.t.ld.slaveReadiness() +func (sf *replicaFileOperations) Readiness(mask waiter.EventMask) waiter.EventMask { + return sf.si.t.ld.replicaReadiness() } // Read implements fs.FileOperations.Read. -func (sf *slaveFileOperations) Read(ctx context.Context, _ *fs.File, dst usermem.IOSequence, _ int64) (int64, error) { +func (sf *replicaFileOperations) Read(ctx context.Context, _ *fs.File, dst usermem.IOSequence, _ int64) (int64, error) { return sf.si.t.ld.inputQueueRead(ctx, dst) } // Write implements fs.FileOperations.Write. -func (sf *slaveFileOperations) Write(ctx context.Context, _ *fs.File, src usermem.IOSequence, _ int64) (int64, error) { +func (sf *replicaFileOperations) Write(ctx context.Context, _ *fs.File, src usermem.IOSequence, _ int64) (int64, error) { return sf.si.t.ld.outputQueueWrite(ctx, src) } // Ioctl implements fs.FileOperations.Ioctl. -func (sf *slaveFileOperations) Ioctl(ctx context.Context, _ *fs.File, io usermem.IO, args arch.SyscallArguments) (uintptr, error) { +func (sf *replicaFileOperations) Ioctl(ctx context.Context, _ *fs.File, io usermem.IO, args arch.SyscallArguments) (uintptr, error) { + t := kernel.TaskFromContext(ctx) + if t == nil { + // ioctl(2) may only be called from a task goroutine. + return 0, syserror.ENOTTY + } + switch cmd := args[1].Uint(); cmd { case linux.FIONREAD: // linux.FIONREAD == linux.TIOCINQ // Get the number of bytes in the input queue read buffer. - return 0, sf.si.t.ld.inputQueueReadSize(ctx, io, args) + return 0, sf.si.t.ld.inputQueueReadSize(t, args) case linux.TCGETS: - return sf.si.t.ld.getTermios(ctx, io, args) + return sf.si.t.ld.getTermios(t, args) case linux.TCSETS: - return sf.si.t.ld.setTermios(ctx, io, args) + return sf.si.t.ld.setTermios(t, args) case linux.TCSETSW: // TODO(b/29356795): This should drain the output queue first. - return sf.si.t.ld.setTermios(ctx, io, args) + return sf.si.t.ld.setTermios(t, args) case linux.TIOCGPTN: - _, err := usermem.CopyObjectOut(ctx, io, args[2].Pointer(), uint32(sf.si.t.n), usermem.IOOpts{ - AddressSpaceActive: true, - }) + nP := primitive.Uint32(sf.si.t.n) + _, err := nP.CopyOut(t, args[2].Pointer()) return 0, err case linux.TIOCGWINSZ: - return 0, sf.si.t.ld.windowSize(ctx, io, args) + return 0, sf.si.t.ld.windowSize(t, args) case linux.TIOCSWINSZ: - return 0, sf.si.t.ld.setWindowSize(ctx, io, args) + return 0, sf.si.t.ld.setWindowSize(t, args) case linux.TIOCSCTTY: // Make the given terminal the controlling terminal of the // calling process. - return 0, sf.si.t.setControllingTTY(ctx, io, args, false /* isMaster */) + return 0, sf.si.t.setControllingTTY(ctx, args, false /* isMaster */) case linux.TIOCNOTTY: // Release this process's controlling terminal. - return 0, sf.si.t.releaseControllingTTY(ctx, io, args, false /* isMaster */) + return 0, sf.si.t.releaseControllingTTY(ctx, args, false /* isMaster */) case linux.TIOCGPGRP: // Get the foreground process group. - return sf.si.t.foregroundProcessGroup(ctx, io, args, false /* isMaster */) + return sf.si.t.foregroundProcessGroup(ctx, args, false /* isMaster */) case linux.TIOCSPGRP: // Set the foreground process group. - return sf.si.t.setForegroundProcessGroup(ctx, io, args, false /* isMaster */) + return sf.si.t.setForegroundProcessGroup(ctx, args, false /* isMaster */) default: maybeEmitUnimplementedEvent(ctx, cmd) return 0, syserror.ENOTTY } } -// LINT.ThenChange(../../fsimpl/devpts/slave.go) +// LINT.ThenChange(../../fsimpl/devpts/replica.go) diff --git a/pkg/sentry/fs/tty/terminal.go b/pkg/sentry/fs/tty/terminal.go index ddcccf4da..4f431d74d 100644 --- a/pkg/sentry/fs/tty/terminal.go +++ b/pkg/sentry/fs/tty/terminal.go @@ -17,10 +17,10 @@ package tty import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/refs" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/kernel" - "gvisor.dev/gvisor/pkg/usermem" ) // LINT.IfChange @@ -44,19 +44,19 @@ type Terminal struct { // this terminal. This field is immutable. masterKTTY *kernel.TTY - // slaveKTTY contains the controlling process of the slave end of this + // replicaKTTY contains the controlling process of the replica end of this // terminal. This field is immutable. - slaveKTTY *kernel.TTY + replicaKTTY *kernel.TTY } func newTerminal(ctx context.Context, d *dirInodeOperations, n uint32) *Terminal { - termios := linux.DefaultSlaveTermios + termios := linux.DefaultReplicaTermios t := Terminal{ - d: d, - n: n, - ld: newLineDiscipline(termios), - masterKTTY: &kernel.TTY{Index: n}, - slaveKTTY: &kernel.TTY{Index: n}, + d: d, + n: n, + ld: newLineDiscipline(termios), + masterKTTY: &kernel.TTY{Index: n}, + replicaKTTY: &kernel.TTY{Index: n}, } t.EnableLeakCheck("tty.Terminal") return &t @@ -64,7 +64,7 @@ func newTerminal(ctx context.Context, d *dirInodeOperations, n uint32) *Terminal // setControllingTTY makes tm the controlling terminal of the calling thread // group. -func (tm *Terminal) setControllingTTY(ctx context.Context, io usermem.IO, args arch.SyscallArguments, isMaster bool) error { +func (tm *Terminal) setControllingTTY(ctx context.Context, args arch.SyscallArguments, isMaster bool) error { task := kernel.TaskFromContext(ctx) if task == nil { panic("setControllingTTY must be called from a task context") @@ -75,7 +75,7 @@ func (tm *Terminal) setControllingTTY(ctx context.Context, io usermem.IO, args a // releaseControllingTTY removes tm as the controlling terminal of the calling // thread group. -func (tm *Terminal) releaseControllingTTY(ctx context.Context, io usermem.IO, args arch.SyscallArguments, isMaster bool) error { +func (tm *Terminal) releaseControllingTTY(ctx context.Context, args arch.SyscallArguments, isMaster bool) error { task := kernel.TaskFromContext(ctx) if task == nil { panic("releaseControllingTTY must be called from a task context") @@ -85,7 +85,7 @@ func (tm *Terminal) releaseControllingTTY(ctx context.Context, io usermem.IO, ar } // foregroundProcessGroup gets the process group ID of tm's foreground process. -func (tm *Terminal) foregroundProcessGroup(ctx context.Context, io usermem.IO, args arch.SyscallArguments, isMaster bool) (uintptr, error) { +func (tm *Terminal) foregroundProcessGroup(ctx context.Context, args arch.SyscallArguments, isMaster bool) (uintptr, error) { task := kernel.TaskFromContext(ctx) if task == nil { panic("foregroundProcessGroup must be called from a task context") @@ -97,24 +97,21 @@ func (tm *Terminal) foregroundProcessGroup(ctx context.Context, io usermem.IO, a } // Write it out to *arg. - _, err = usermem.CopyObjectOut(ctx, io, args[2].Pointer(), int32(ret), usermem.IOOpts{ - AddressSpaceActive: true, - }) + retP := primitive.Int32(ret) + _, err = retP.CopyOut(task, args[2].Pointer()) return 0, err } // foregroundProcessGroup sets tm's foreground process. -func (tm *Terminal) setForegroundProcessGroup(ctx context.Context, io usermem.IO, args arch.SyscallArguments, isMaster bool) (uintptr, error) { +func (tm *Terminal) setForegroundProcessGroup(ctx context.Context, args arch.SyscallArguments, isMaster bool) (uintptr, error) { task := kernel.TaskFromContext(ctx) if task == nil { panic("setForegroundProcessGroup must be called from a task context") } // Read in the process group ID. - var pgid int32 - if _, err := usermem.CopyObjectIn(ctx, io, args[2].Pointer(), &pgid, usermem.IOOpts{ - AddressSpaceActive: true, - }); err != nil { + var pgid primitive.Int32 + if _, err := pgid.CopyIn(task, args[2].Pointer()); err != nil { return 0, err } @@ -126,7 +123,7 @@ func (tm *Terminal) tty(isMaster bool) *kernel.TTY { if isMaster { return tm.masterKTTY } - return tm.slaveKTTY + return tm.replicaKTTY } // LINT.ThenChange(../../fsimpl/devpts/terminal.go) diff --git a/pkg/sentry/fs/tty/tty_test.go b/pkg/sentry/fs/tty/tty_test.go index 2cbc05678..49edee83d 100644 --- a/pkg/sentry/fs/tty/tty_test.go +++ b/pkg/sentry/fs/tty/tty_test.go @@ -22,8 +22,8 @@ import ( "gvisor.dev/gvisor/pkg/usermem" ) -func TestSimpleMasterToSlave(t *testing.T) { - ld := newLineDiscipline(linux.DefaultSlaveTermios) +func TestSimpleMasterToReplica(t *testing.T) { + ld := newLineDiscipline(linux.DefaultReplicaTermios) ctx := contexttest.Context(t) inBytes := []byte("hello, tty\n") src := usermem.BytesIOSequence(inBytes) diff --git a/pkg/sentry/fsimpl/devpts/BUILD b/pkg/sentry/fsimpl/devpts/BUILD index 3f64fab3a..48e13613a 100644 --- a/pkg/sentry/fsimpl/devpts/BUILD +++ b/pkg/sentry/fsimpl/devpts/BUILD @@ -21,8 +21,8 @@ go_library( "line_discipline.go", "master.go", "queue.go", + "replica.go", "root_inode_refs.go", - "slave.go", "terminal.go", ], visibility = ["//pkg/sentry:internal"], @@ -30,6 +30,8 @@ go_library( "//pkg/abi/linux", "//pkg/context", "//pkg/log", + "//pkg/marshal", + "//pkg/marshal/primitive", "//pkg/refs", "//pkg/safemem", "//pkg/sentry/arch", diff --git a/pkg/sentry/fsimpl/devpts/devpts.go b/pkg/sentry/fsimpl/devpts/devpts.go index 57580f4d4..903135fae 100644 --- a/pkg/sentry/fsimpl/devpts/devpts.go +++ b/pkg/sentry/fsimpl/devpts/devpts.go @@ -35,6 +35,8 @@ import ( const Name = "devpts" // FilesystemType implements vfs.FilesystemType. +// +// +stateify savable type FilesystemType struct{} // Name implements vfs.FilesystemType.Name. @@ -58,6 +60,7 @@ func (fstype FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt return fs.Filesystem.VFSFilesystem(), root.VFSDentry(), nil } +// +stateify savable type filesystem struct { kernfs.Filesystem @@ -79,7 +82,7 @@ func (fstype FilesystemType) newFilesystem(vfsObj *vfs.VirtualFilesystem, creds // Construct the root directory. This is always inode id 1. root := &rootInode{ - slaves: make(map[uint32]*slaveInode), + replicas: make(map[uint32]*replicaInode), } root.InodeAttrs.Init(creds, linux.UNNAMED_MAJOR, devMinor, 1, linux.ModeDirectory|0555) root.OrderedChildren.Init(kernfs.OrderedChildrenOptions{}) @@ -110,6 +113,8 @@ func (fs *filesystem) Release(ctx context.Context) { } // rootInode is the root directory inode for the devpts mounts. +// +// +stateify savable type rootInode struct { implStatFS kernfs.AlwaysValid @@ -131,10 +136,10 @@ type rootInode struct { root *rootInode // mu protects the fields below. - mu sync.Mutex + mu sync.Mutex `state:"nosave"` - // slaves maps pty ids to slave inodes. - slaves map[uint32]*slaveInode + // replicas maps pty ids to replica inodes. + replicas map[uint32]*replicaInode // nextIdx is the next pty index to use. Must be accessed atomically. // @@ -154,22 +159,22 @@ func (i *rootInode) allocateTerminal(creds *auth.Credentials) (*Terminal, error) idx := i.nextIdx i.nextIdx++ - // Sanity check that slave with idx does not exist. - if _, ok := i.slaves[idx]; ok { + // Sanity check that replica with idx does not exist. + if _, ok := i.replicas[idx]; ok { panic(fmt.Sprintf("pty index collision; index %d already exists", idx)) } - // Create the new terminal and slave. + // Create the new terminal and replica. t := newTerminal(idx) - slave := &slaveInode{ + replica := &replicaInode{ root: i, t: t, } // Linux always uses pty index + 3 as the inode id. See // fs/devpts/inode.c:devpts_pty_new(). - slave.InodeAttrs.Init(creds, i.InodeAttrs.DevMajor(), i.InodeAttrs.DevMinor(), uint64(idx+3), linux.ModeCharacterDevice|0600) - slave.dentry.Init(slave) - i.slaves[idx] = slave + replica.InodeAttrs.Init(creds, i.InodeAttrs.DevMajor(), i.InodeAttrs.DevMinor(), uint64(idx+3), linux.ModeCharacterDevice|0600) + replica.dentry.Init(replica) + i.replicas[idx] = replica return t, nil } @@ -179,16 +184,16 @@ func (i *rootInode) masterClose(t *Terminal) { i.mu.Lock() defer i.mu.Unlock() - // Sanity check that slave with idx exists. - if _, ok := i.slaves[t.n]; !ok { + // Sanity check that replica with idx exists. + if _, ok := i.replicas[t.n]; !ok { panic(fmt.Sprintf("pty with index %d does not exist", t.n)) } - delete(i.slaves, t.n) + delete(i.replicas, t.n) } // Open implements kernfs.Inode.Open. -func (i *rootInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { - fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &i.OrderedChildren, &i.locks, &opts, kernfs.GenericDirectoryFDOptions{ +func (i *rootInode) Open(ctx context.Context, rp *vfs.ResolvingPath, d *kernfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { + fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), d, &i.OrderedChildren, &i.locks, &opts, kernfs.GenericDirectoryFDOptions{ SeekEnd: kernfs.SeekEndStaticEntries, }) if err != nil { @@ -198,16 +203,16 @@ func (i *rootInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.D } // Lookup implements kernfs.Inode.Lookup. -func (i *rootInode) Lookup(ctx context.Context, name string) (*vfs.Dentry, error) { +func (i *rootInode) Lookup(ctx context.Context, name string) (*kernfs.Dentry, error) { idx, err := strconv.ParseUint(name, 10, 32) if err != nil { return nil, syserror.ENOENT } i.mu.Lock() defer i.mu.Unlock() - if si, ok := i.slaves[uint32(idx)]; ok { + if si, ok := i.replicas[uint32(idx)]; ok { si.dentry.IncRef() - return si.dentry.VFSDentry(), nil + return &si.dentry, nil } return nil, syserror.ENOENT @@ -217,8 +222,8 @@ func (i *rootInode) Lookup(ctx context.Context, name string) (*vfs.Dentry, error func (i *rootInode) IterDirents(ctx context.Context, cb vfs.IterDirentsCallback, offset, relOffset int64) (int64, error) { i.mu.Lock() defer i.mu.Unlock() - ids := make([]int, 0, len(i.slaves)) - for id := range i.slaves { + ids := make([]int, 0, len(i.replicas)) + for id := range i.replicas { ids = append(ids, int(id)) } sort.Ints(ids) @@ -226,7 +231,7 @@ func (i *rootInode) IterDirents(ctx context.Context, cb vfs.IterDirentsCallback, dirent := vfs.Dirent{ Name: strconv.FormatUint(uint64(id), 10), Type: linux.DT_CHR, - Ino: i.slaves[uint32(id)].InodeAttrs.Ino(), + Ino: i.replicas[uint32(id)].InodeAttrs.Ino(), NextOff: offset + 1, } if err := cb.Handle(dirent); err != nil { @@ -237,11 +242,12 @@ func (i *rootInode) IterDirents(ctx context.Context, cb vfs.IterDirentsCallback, return offset, nil } -// DecRef implements kernfs.Inode. +// DecRef implements kernfs.Inode.DecRef. func (i *rootInode) DecRef(context.Context) { i.rootInodeRefs.DecRef(i.Destroy) } +// +stateify savable type implStatFS struct{} // StatFS implements kernfs.Inode.StatFS. diff --git a/pkg/sentry/fsimpl/devpts/devpts_test.go b/pkg/sentry/fsimpl/devpts/devpts_test.go index b7c149047..448390cfe 100644 --- a/pkg/sentry/fsimpl/devpts/devpts_test.go +++ b/pkg/sentry/fsimpl/devpts/devpts_test.go @@ -22,8 +22,8 @@ import ( "gvisor.dev/gvisor/pkg/usermem" ) -func TestSimpleMasterToSlave(t *testing.T) { - ld := newLineDiscipline(linux.DefaultSlaveTermios) +func TestSimpleMasterToReplica(t *testing.T) { + ld := newLineDiscipline(linux.DefaultReplicaTermios) ctx := contexttest.Context(t) inBytes := []byte("hello, tty\n") src := usermem.BytesIOSequence(inBytes) diff --git a/pkg/sentry/fsimpl/devpts/line_discipline.go b/pkg/sentry/fsimpl/devpts/line_discipline.go index f7bc325d1..e6b0e81cf 100644 --- a/pkg/sentry/fsimpl/devpts/line_discipline.go +++ b/pkg/sentry/fsimpl/devpts/line_discipline.go @@ -21,6 +21,7 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/sentry/arch" + "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/usermem" @@ -41,7 +42,7 @@ const ( ) // lineDiscipline dictates how input and output are handled between the -// pseudoterminal (pty) master and slave. It can be configured to alter I/O, +// pseudoterminal (pty) master and replica. It can be configured to alter I/O, // modify control characters (e.g. Ctrl-C for SIGINT), etc. The following man // pages are good resources for how to affect the line discipline: // @@ -52,8 +53,8 @@ const ( // // lineDiscipline has a simple structure but supports a multitude of options // (see the above man pages). It consists of two queues of bytes: one from the -// terminal master to slave (the input queue) and one from slave to master (the -// output queue). When bytes are written to one end of the pty, the line +// terminal master to replica (the input queue) and one from replica to master +// (the output queue). When bytes are written to one end of the pty, the line // discipline reads the bytes, modifies them or takes special action if // required, and enqueues them to be read by the other end of the pty: // @@ -62,7 +63,7 @@ const ( // | (inputQueueWrite) +-------------+ (inputQueueRead) | // | | // | v -// masterFD slaveFD +// masterFD replicaFD // ^ | // | | // | output to terminal +--------------+ output from process | @@ -101,8 +102,8 @@ type lineDiscipline struct { // masterWaiter is used to wait on the master end of the TTY. masterWaiter waiter.Queue `state:"zerovalue"` - // slaveWaiter is used to wait on the slave end of the TTY. - slaveWaiter waiter.Queue `state:"zerovalue"` + // replicaWaiter is used to wait on the replica end of the TTY. + replicaWaiter waiter.Queue `state:"zerovalue"` } func newLineDiscipline(termios linux.KernelTermios) *lineDiscipline { @@ -113,27 +114,23 @@ func newLineDiscipline(termios linux.KernelTermios) *lineDiscipline { } // getTermios gets the linux.Termios for the tty. -func (l *lineDiscipline) getTermios(ctx context.Context, io usermem.IO, args arch.SyscallArguments) (uintptr, error) { +func (l *lineDiscipline) getTermios(task *kernel.Task, args arch.SyscallArguments) (uintptr, error) { l.termiosMu.RLock() defer l.termiosMu.RUnlock() // We must copy a Termios struct, not KernelTermios. t := l.termios.ToTermios() - _, err := usermem.CopyObjectOut(ctx, io, args[2].Pointer(), t, usermem.IOOpts{ - AddressSpaceActive: true, - }) + _, err := t.CopyOut(task, args[2].Pointer()) return 0, err } // setTermios sets a linux.Termios for the tty. -func (l *lineDiscipline) setTermios(ctx context.Context, io usermem.IO, args arch.SyscallArguments) (uintptr, error) { +func (l *lineDiscipline) setTermios(task *kernel.Task, args arch.SyscallArguments) (uintptr, error) { l.termiosMu.Lock() defer l.termiosMu.Unlock() oldCanonEnabled := l.termios.LEnabled(linux.ICANON) // We must copy a Termios struct, not KernelTermios. var t linux.Termios - _, err := usermem.CopyObjectIn(ctx, io, args[2].Pointer(), &t, usermem.IOOpts{ - AddressSpaceActive: true, - }) + _, err := t.CopyIn(task, args[2].Pointer()) l.termios.FromTermios(t) // If canonical mode is turned off, move bytes from inQueue's wait @@ -144,27 +141,23 @@ func (l *lineDiscipline) setTermios(ctx context.Context, io usermem.IO, args arc l.inQueue.pushWaitBufLocked(l) l.inQueue.readable = true l.inQueue.mu.Unlock() - l.slaveWaiter.Notify(waiter.EventIn) + l.replicaWaiter.Notify(waiter.EventIn) } return 0, err } -func (l *lineDiscipline) windowSize(ctx context.Context, io usermem.IO, args arch.SyscallArguments) error { +func (l *lineDiscipline) windowSize(t *kernel.Task, args arch.SyscallArguments) error { l.sizeMu.Lock() defer l.sizeMu.Unlock() - _, err := usermem.CopyObjectOut(ctx, io, args[2].Pointer(), l.size, usermem.IOOpts{ - AddressSpaceActive: true, - }) + _, err := l.size.CopyOut(t, args[2].Pointer()) return err } -func (l *lineDiscipline) setWindowSize(ctx context.Context, io usermem.IO, args arch.SyscallArguments) error { +func (l *lineDiscipline) setWindowSize(t *kernel.Task, args arch.SyscallArguments) error { l.sizeMu.Lock() defer l.sizeMu.Unlock() - _, err := usermem.CopyObjectIn(ctx, io, args[2].Pointer(), &l.size, usermem.IOOpts{ - AddressSpaceActive: true, - }) + _, err := l.size.CopyIn(t, args[2].Pointer()) return err } @@ -174,14 +167,14 @@ func (l *lineDiscipline) masterReadiness() waiter.EventMask { return l.inQueue.writeReadiness(&linux.MasterTermios) | l.outQueue.readReadiness(&linux.MasterTermios) } -func (l *lineDiscipline) slaveReadiness() waiter.EventMask { +func (l *lineDiscipline) replicaReadiness() waiter.EventMask { l.termiosMu.RLock() defer l.termiosMu.RUnlock() return l.outQueue.writeReadiness(&l.termios) | l.inQueue.readReadiness(&l.termios) } -func (l *lineDiscipline) inputQueueReadSize(ctx context.Context, io usermem.IO, args arch.SyscallArguments) error { - return l.inQueue.readableSize(ctx, io, args) +func (l *lineDiscipline) inputQueueReadSize(t *kernel.Task, io usermem.IO, args arch.SyscallArguments) error { + return l.inQueue.readableSize(t, io, args) } func (l *lineDiscipline) inputQueueRead(ctx context.Context, dst usermem.IOSequence) (int64, error) { @@ -194,7 +187,7 @@ func (l *lineDiscipline) inputQueueRead(ctx context.Context, dst usermem.IOSeque if n > 0 { l.masterWaiter.Notify(waiter.EventOut) if pushed { - l.slaveWaiter.Notify(waiter.EventIn) + l.replicaWaiter.Notify(waiter.EventIn) } return n, nil } @@ -209,14 +202,14 @@ func (l *lineDiscipline) inputQueueWrite(ctx context.Context, src usermem.IOSequ return 0, err } if n > 0 { - l.slaveWaiter.Notify(waiter.EventIn) + l.replicaWaiter.Notify(waiter.EventIn) return n, nil } return 0, syserror.ErrWouldBlock } -func (l *lineDiscipline) outputQueueReadSize(ctx context.Context, io usermem.IO, args arch.SyscallArguments) error { - return l.outQueue.readableSize(ctx, io, args) +func (l *lineDiscipline) outputQueueReadSize(t *kernel.Task, io usermem.IO, args arch.SyscallArguments) error { + return l.outQueue.readableSize(t, io, args) } func (l *lineDiscipline) outputQueueRead(ctx context.Context, dst usermem.IOSequence) (int64, error) { @@ -227,7 +220,7 @@ func (l *lineDiscipline) outputQueueRead(ctx context.Context, dst usermem.IOSequ return 0, err } if n > 0 { - l.slaveWaiter.Notify(waiter.EventOut) + l.replicaWaiter.Notify(waiter.EventOut) if pushed { l.masterWaiter.Notify(waiter.EventIn) } diff --git a/pkg/sentry/fsimpl/devpts/master.go b/pkg/sentry/fsimpl/devpts/master.go index 60feb1993..69c2fe951 100644 --- a/pkg/sentry/fsimpl/devpts/master.go +++ b/pkg/sentry/fsimpl/devpts/master.go @@ -17,9 +17,11 @@ package devpts import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/arch" fslock "gvisor.dev/gvisor/pkg/sentry/fs/lock" "gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs" + "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/sentry/unimpl" "gvisor.dev/gvisor/pkg/sentry/vfs" @@ -29,6 +31,8 @@ import ( ) // masterInode is the inode for the master end of the Terminal. +// +// +stateify savable type masterInode struct { implStatFS kernfs.InodeAttrs @@ -48,20 +52,18 @@ type masterInode struct { var _ kernfs.Inode = (*masterInode)(nil) // Open implements kernfs.Inode.Open. -func (mi *masterInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { +func (mi *masterInode) Open(ctx context.Context, rp *vfs.ResolvingPath, d *kernfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { t, err := mi.root.allocateTerminal(rp.Credentials()) if err != nil { return nil, err } - mi.IncRef() fd := &masterFileDescription{ inode: mi, t: t, } fd.LockFD.Init(&mi.locks) - if err := fd.vfsfd.Init(fd, opts.Flags, rp.Mount(), vfsd, &vfs.FileDescriptionOptions{}); err != nil { - mi.DecRef(ctx) + if err := fd.vfsfd.Init(fd, opts.Flags, rp.Mount(), d.VFSDentry(), &vfs.FileDescriptionOptions{}); err != nil { return nil, err } return &fd.vfsfd, nil @@ -87,6 +89,7 @@ func (mi *masterInode) SetStat(ctx context.Context, vfsfs *vfs.Filesystem, creds return mi.InodeAttrs.SetStat(ctx, vfsfs, creds, opts) } +// +stateify savable type masterFileDescription struct { vfsfd vfs.FileDescription vfs.FileDescriptionDefaultImpl @@ -101,7 +104,6 @@ var _ vfs.FileDescriptionImpl = (*masterFileDescription)(nil) // Release implements vfs.FileDescriptionImpl.Release. func (mfd *masterFileDescription) Release(ctx context.Context) { mfd.inode.root.masterClose(mfd.t) - mfd.inode.DecRef(ctx) } // EventRegister implements waiter.Waitable.EventRegister. @@ -131,46 +133,51 @@ func (mfd *masterFileDescription) Write(ctx context.Context, src usermem.IOSeque // Ioctl implements vfs.FileDescriptionImpl.Ioctl. func (mfd *masterFileDescription) Ioctl(ctx context.Context, io usermem.IO, args arch.SyscallArguments) (uintptr, error) { + t := kernel.TaskFromContext(ctx) + if t == nil { + // ioctl(2) may only be called from a task goroutine. + return 0, syserror.ENOTTY + } + switch cmd := args[1].Uint(); cmd { case linux.FIONREAD: // linux.FIONREAD == linux.TIOCINQ // Get the number of bytes in the output queue read buffer. - return 0, mfd.t.ld.outputQueueReadSize(ctx, io, args) + return 0, mfd.t.ld.outputQueueReadSize(t, io, args) case linux.TCGETS: // N.B. TCGETS on the master actually returns the configuration - // of the slave end. - return mfd.t.ld.getTermios(ctx, io, args) + // of the replica end. + return mfd.t.ld.getTermios(t, args) case linux.TCSETS: // N.B. TCSETS on the master actually affects the configuration - // of the slave end. - return mfd.t.ld.setTermios(ctx, io, args) + // of the replica end. + return mfd.t.ld.setTermios(t, args) case linux.TCSETSW: // TODO(b/29356795): This should drain the output queue first. - return mfd.t.ld.setTermios(ctx, io, args) + return mfd.t.ld.setTermios(t, args) case linux.TIOCGPTN: - _, err := usermem.CopyObjectOut(ctx, io, args[2].Pointer(), uint32(mfd.t.n), usermem.IOOpts{ - AddressSpaceActive: true, - }) + nP := primitive.Uint32(mfd.t.n) + _, err := nP.CopyOut(t, args[2].Pointer()) return 0, err case linux.TIOCSPTLCK: // TODO(b/29356795): Implement pty locking. For now just pretend we do. return 0, nil case linux.TIOCGWINSZ: - return 0, mfd.t.ld.windowSize(ctx, io, args) + return 0, mfd.t.ld.windowSize(t, args) case linux.TIOCSWINSZ: - return 0, mfd.t.ld.setWindowSize(ctx, io, args) + return 0, mfd.t.ld.setWindowSize(t, args) case linux.TIOCSCTTY: // Make the given terminal the controlling terminal of the // calling process. - return 0, mfd.t.setControllingTTY(ctx, io, args, true /* isMaster */) + return 0, mfd.t.setControllingTTY(ctx, args, true /* isMaster */) case linux.TIOCNOTTY: // Release this process's controlling terminal. - return 0, mfd.t.releaseControllingTTY(ctx, io, args, true /* isMaster */) + return 0, mfd.t.releaseControllingTTY(ctx, args, true /* isMaster */) case linux.TIOCGPGRP: // Get the foreground process group. - return mfd.t.foregroundProcessGroup(ctx, io, args, true /* isMaster */) + return mfd.t.foregroundProcessGroup(ctx, args, true /* isMaster */) case linux.TIOCSPGRP: // Set the foreground process group. - return mfd.t.setForegroundProcessGroup(ctx, io, args, true /* isMaster */) + return mfd.t.setForegroundProcessGroup(ctx, args, true /* isMaster */) default: maybeEmitUnimplementedEvent(ctx, cmd) return 0, syserror.ENOTTY diff --git a/pkg/sentry/fsimpl/devpts/queue.go b/pkg/sentry/fsimpl/devpts/queue.go index 331c13997..55bff3e60 100644 --- a/pkg/sentry/fsimpl/devpts/queue.go +++ b/pkg/sentry/fsimpl/devpts/queue.go @@ -17,8 +17,10 @@ package devpts import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/safemem" "gvisor.dev/gvisor/pkg/sentry/arch" + "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/usermem" @@ -30,7 +32,7 @@ import ( const waitBufMaxBytes = 131072 // queue represents one of the input or output queues between a pty master and -// slave. Bytes written to a queue are added to the read buffer until it is +// replica. Bytes written to a queue are added to the read buffer until it is // full, at which point they are written to the wait buffer. Bytes are // processed (i.e. undergo termios transformations) as they are added to the // read buffer. The read buffer is readable when its length is nonzero and @@ -83,17 +85,15 @@ func (q *queue) writeReadiness(t *linux.KernelTermios) waiter.EventMask { } // readableSize writes the number of readable bytes to userspace. -func (q *queue) readableSize(ctx context.Context, io usermem.IO, args arch.SyscallArguments) error { +func (q *queue) readableSize(t *kernel.Task, io usermem.IO, args arch.SyscallArguments) error { q.mu.Lock() defer q.mu.Unlock() - var size int32 + size := primitive.Int32(0) if q.readable { - size = int32(len(q.readBuf)) + size = primitive.Int32(len(q.readBuf)) } - _, err := usermem.CopyObjectOut(ctx, io, args[2].Pointer(), size, usermem.IOOpts{ - AddressSpaceActive: true, - }) + _, err := size.CopyOut(t, args[2].Pointer()) return err } diff --git a/pkg/sentry/fsimpl/devpts/replica.go b/pkg/sentry/fsimpl/devpts/replica.go new file mode 100644 index 000000000..6515c5536 --- /dev/null +++ b/pkg/sentry/fsimpl/devpts/replica.go @@ -0,0 +1,204 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package devpts + +import ( + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/marshal/primitive" + "gvisor.dev/gvisor/pkg/sentry/arch" + fslock "gvisor.dev/gvisor/pkg/sentry/fs/lock" + "gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs" + "gvisor.dev/gvisor/pkg/sentry/kernel" + "gvisor.dev/gvisor/pkg/sentry/kernel/auth" + "gvisor.dev/gvisor/pkg/sentry/vfs" + "gvisor.dev/gvisor/pkg/syserror" + "gvisor.dev/gvisor/pkg/usermem" + "gvisor.dev/gvisor/pkg/waiter" +) + +// replicaInode is the inode for the replica end of the Terminal. +// +// +stateify savable +type replicaInode struct { + implStatFS + kernfs.InodeAttrs + kernfs.InodeNoopRefCount + kernfs.InodeNotDirectory + kernfs.InodeNotSymlink + + locks vfs.FileLocks + + // Keep a reference to this inode's dentry. + dentry kernfs.Dentry + + // root is the devpts root inode. + root *rootInode + + // t is the connected Terminal. + t *Terminal +} + +var _ kernfs.Inode = (*replicaInode)(nil) + +// Open implements kernfs.Inode.Open. +func (ri *replicaInode) Open(ctx context.Context, rp *vfs.ResolvingPath, d *kernfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { + fd := &replicaFileDescription{ + inode: ri, + } + fd.LockFD.Init(&ri.locks) + if err := fd.vfsfd.Init(fd, opts.Flags, rp.Mount(), d.VFSDentry(), &vfs.FileDescriptionOptions{}); err != nil { + return nil, err + } + return &fd.vfsfd, nil + +} + +// Valid implements kernfs.Inode.Valid. +func (ri *replicaInode) Valid(context.Context) bool { + // Return valid if the replica still exists. + ri.root.mu.Lock() + defer ri.root.mu.Unlock() + _, ok := ri.root.replicas[ri.t.n] + return ok +} + +// Stat implements kernfs.Inode.Stat. +func (ri *replicaInode) Stat(ctx context.Context, vfsfs *vfs.Filesystem, opts vfs.StatOptions) (linux.Statx, error) { + statx, err := ri.InodeAttrs.Stat(ctx, vfsfs, opts) + if err != nil { + return linux.Statx{}, err + } + statx.Blksize = 1024 + statx.RdevMajor = linux.UNIX98_PTY_REPLICA_MAJOR + statx.RdevMinor = ri.t.n + return statx, nil +} + +// SetStat implements kernfs.Inode.SetStat +func (ri *replicaInode) SetStat(ctx context.Context, vfsfs *vfs.Filesystem, creds *auth.Credentials, opts vfs.SetStatOptions) error { + if opts.Stat.Mask&linux.STATX_SIZE != 0 { + return syserror.EINVAL + } + return ri.InodeAttrs.SetStat(ctx, vfsfs, creds, opts) +} + +// +stateify savable +type replicaFileDescription struct { + vfsfd vfs.FileDescription + vfs.FileDescriptionDefaultImpl + vfs.LockFD + + inode *replicaInode +} + +var _ vfs.FileDescriptionImpl = (*replicaFileDescription)(nil) + +// Release implements fs.FileOperations.Release. +func (rfd *replicaFileDescription) Release(ctx context.Context) {} + +// EventRegister implements waiter.Waitable.EventRegister. +func (rfd *replicaFileDescription) EventRegister(e *waiter.Entry, mask waiter.EventMask) { + rfd.inode.t.ld.replicaWaiter.EventRegister(e, mask) +} + +// EventUnregister implements waiter.Waitable.EventUnregister. +func (rfd *replicaFileDescription) EventUnregister(e *waiter.Entry) { + rfd.inode.t.ld.replicaWaiter.EventUnregister(e) +} + +// Readiness implements waiter.Waitable.Readiness. +func (rfd *replicaFileDescription) Readiness(mask waiter.EventMask) waiter.EventMask { + return rfd.inode.t.ld.replicaReadiness() +} + +// Read implements vfs.FileDescriptionImpl.Read. +func (rfd *replicaFileDescription) Read(ctx context.Context, dst usermem.IOSequence, _ vfs.ReadOptions) (int64, error) { + return rfd.inode.t.ld.inputQueueRead(ctx, dst) +} + +// Write implements vfs.FileDescriptionImpl.Write. +func (rfd *replicaFileDescription) Write(ctx context.Context, src usermem.IOSequence, _ vfs.WriteOptions) (int64, error) { + return rfd.inode.t.ld.outputQueueWrite(ctx, src) +} + +// Ioctl implements vfs.FileDescriptionImpl.Ioctl. +func (rfd *replicaFileDescription) Ioctl(ctx context.Context, io usermem.IO, args arch.SyscallArguments) (uintptr, error) { + t := kernel.TaskFromContext(ctx) + if t == nil { + // ioctl(2) may only be called from a task goroutine. + return 0, syserror.ENOTTY + } + + switch cmd := args[1].Uint(); cmd { + case linux.FIONREAD: // linux.FIONREAD == linux.TIOCINQ + // Get the number of bytes in the input queue read buffer. + return 0, rfd.inode.t.ld.inputQueueReadSize(t, io, args) + case linux.TCGETS: + return rfd.inode.t.ld.getTermios(t, args) + case linux.TCSETS: + return rfd.inode.t.ld.setTermios(t, args) + case linux.TCSETSW: + // TODO(b/29356795): This should drain the output queue first. + return rfd.inode.t.ld.setTermios(t, args) + case linux.TIOCGPTN: + nP := primitive.Uint32(rfd.inode.t.n) + _, err := nP.CopyOut(t, args[2].Pointer()) + return 0, err + case linux.TIOCGWINSZ: + return 0, rfd.inode.t.ld.windowSize(t, args) + case linux.TIOCSWINSZ: + return 0, rfd.inode.t.ld.setWindowSize(t, args) + case linux.TIOCSCTTY: + // Make the given terminal the controlling terminal of the + // calling process. + return 0, rfd.inode.t.setControllingTTY(ctx, args, false /* isMaster */) + case linux.TIOCNOTTY: + // Release this process's controlling terminal. + return 0, rfd.inode.t.releaseControllingTTY(ctx, args, false /* isMaster */) + case linux.TIOCGPGRP: + // Get the foreground process group. + return rfd.inode.t.foregroundProcessGroup(ctx, args, false /* isMaster */) + case linux.TIOCSPGRP: + // Set the foreground process group. + return rfd.inode.t.setForegroundProcessGroup(ctx, args, false /* isMaster */) + default: + maybeEmitUnimplementedEvent(ctx, cmd) + return 0, syserror.ENOTTY + } +} + +// SetStat implements vfs.FileDescriptionImpl.SetStat. +func (rfd *replicaFileDescription) SetStat(ctx context.Context, opts vfs.SetStatOptions) error { + creds := auth.CredentialsFromContext(ctx) + fs := rfd.vfsfd.VirtualDentry().Mount().Filesystem() + return rfd.inode.SetStat(ctx, fs, creds, opts) +} + +// Stat implements vfs.FileDescriptionImpl.Stat. +func (rfd *replicaFileDescription) Stat(ctx context.Context, opts vfs.StatOptions) (linux.Statx, error) { + fs := rfd.vfsfd.VirtualDentry().Mount().Filesystem() + return rfd.inode.Stat(ctx, fs, opts) +} + +// LockPOSIX implements vfs.FileDescriptionImpl.LockPOSIX. +func (rfd *replicaFileDescription) LockPOSIX(ctx context.Context, uid fslock.UniqueID, t fslock.LockType, start, length uint64, whence int16, block fslock.Blocker) error { + return rfd.Locks().LockPOSIX(ctx, &rfd.vfsfd, uid, t, start, length, whence, block) +} + +// UnlockPOSIX implements vfs.FileDescriptionImpl.UnlockPOSIX. +func (rfd *replicaFileDescription) UnlockPOSIX(ctx context.Context, uid fslock.UniqueID, start, length uint64, whence int16) error { + return rfd.Locks().UnlockPOSIX(ctx, &rfd.vfsfd, uid, start, length, whence) +} diff --git a/pkg/sentry/fsimpl/devpts/slave.go b/pkg/sentry/fsimpl/devpts/slave.go deleted file mode 100644 index a9da7af64..000000000 --- a/pkg/sentry/fsimpl/devpts/slave.go +++ /dev/null @@ -1,198 +0,0 @@ -// Copyright 2020 The gVisor Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// http://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. - -package devpts - -import ( - "gvisor.dev/gvisor/pkg/abi/linux" - "gvisor.dev/gvisor/pkg/context" - "gvisor.dev/gvisor/pkg/sentry/arch" - fslock "gvisor.dev/gvisor/pkg/sentry/fs/lock" - "gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs" - "gvisor.dev/gvisor/pkg/sentry/kernel/auth" - "gvisor.dev/gvisor/pkg/sentry/vfs" - "gvisor.dev/gvisor/pkg/syserror" - "gvisor.dev/gvisor/pkg/usermem" - "gvisor.dev/gvisor/pkg/waiter" -) - -// slaveInode is the inode for the slave end of the Terminal. -type slaveInode struct { - implStatFS - kernfs.InodeAttrs - kernfs.InodeNoopRefCount - kernfs.InodeNotDirectory - kernfs.InodeNotSymlink - - locks vfs.FileLocks - - // Keep a reference to this inode's dentry. - dentry kernfs.Dentry - - // root is the devpts root inode. - root *rootInode - - // t is the connected Terminal. - t *Terminal -} - -var _ kernfs.Inode = (*slaveInode)(nil) - -// Open implements kernfs.Inode.Open. -func (si *slaveInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { - si.IncRef() - fd := &slaveFileDescription{ - inode: si, - } - fd.LockFD.Init(&si.locks) - if err := fd.vfsfd.Init(fd, opts.Flags, rp.Mount(), vfsd, &vfs.FileDescriptionOptions{}); err != nil { - si.DecRef(ctx) - return nil, err - } - return &fd.vfsfd, nil - -} - -// Valid implements kernfs.Inode.Valid. -func (si *slaveInode) Valid(context.Context) bool { - // Return valid if the slave still exists. - si.root.mu.Lock() - defer si.root.mu.Unlock() - _, ok := si.root.slaves[si.t.n] - return ok -} - -// Stat implements kernfs.Inode.Stat. -func (si *slaveInode) Stat(ctx context.Context, vfsfs *vfs.Filesystem, opts vfs.StatOptions) (linux.Statx, error) { - statx, err := si.InodeAttrs.Stat(ctx, vfsfs, opts) - if err != nil { - return linux.Statx{}, err - } - statx.Blksize = 1024 - statx.RdevMajor = linux.UNIX98_PTY_SLAVE_MAJOR - statx.RdevMinor = si.t.n - return statx, nil -} - -// SetStat implements kernfs.Inode.SetStat -func (si *slaveInode) SetStat(ctx context.Context, vfsfs *vfs.Filesystem, creds *auth.Credentials, opts vfs.SetStatOptions) error { - if opts.Stat.Mask&linux.STATX_SIZE != 0 { - return syserror.EINVAL - } - return si.InodeAttrs.SetStat(ctx, vfsfs, creds, opts) -} - -type slaveFileDescription struct { - vfsfd vfs.FileDescription - vfs.FileDescriptionDefaultImpl - vfs.LockFD - - inode *slaveInode -} - -var _ vfs.FileDescriptionImpl = (*slaveFileDescription)(nil) - -// Release implements fs.FileOperations.Release. -func (sfd *slaveFileDescription) Release(ctx context.Context) { - sfd.inode.DecRef(ctx) -} - -// EventRegister implements waiter.Waitable.EventRegister. -func (sfd *slaveFileDescription) EventRegister(e *waiter.Entry, mask waiter.EventMask) { - sfd.inode.t.ld.slaveWaiter.EventRegister(e, mask) -} - -// EventUnregister implements waiter.Waitable.EventUnregister. -func (sfd *slaveFileDescription) EventUnregister(e *waiter.Entry) { - sfd.inode.t.ld.slaveWaiter.EventUnregister(e) -} - -// Readiness implements waiter.Waitable.Readiness. -func (sfd *slaveFileDescription) Readiness(mask waiter.EventMask) waiter.EventMask { - return sfd.inode.t.ld.slaveReadiness() -} - -// Read implements vfs.FileDescriptionImpl.Read. -func (sfd *slaveFileDescription) Read(ctx context.Context, dst usermem.IOSequence, _ vfs.ReadOptions) (int64, error) { - return sfd.inode.t.ld.inputQueueRead(ctx, dst) -} - -// Write implements vfs.FileDescriptionImpl.Write. -func (sfd *slaveFileDescription) Write(ctx context.Context, src usermem.IOSequence, _ vfs.WriteOptions) (int64, error) { - return sfd.inode.t.ld.outputQueueWrite(ctx, src) -} - -// Ioctl implements vfs.FileDescriptionImpl.Ioctl. -func (sfd *slaveFileDescription) Ioctl(ctx context.Context, io usermem.IO, args arch.SyscallArguments) (uintptr, error) { - switch cmd := args[1].Uint(); cmd { - case linux.FIONREAD: // linux.FIONREAD == linux.TIOCINQ - // Get the number of bytes in the input queue read buffer. - return 0, sfd.inode.t.ld.inputQueueReadSize(ctx, io, args) - case linux.TCGETS: - return sfd.inode.t.ld.getTermios(ctx, io, args) - case linux.TCSETS: - return sfd.inode.t.ld.setTermios(ctx, io, args) - case linux.TCSETSW: - // TODO(b/29356795): This should drain the output queue first. - return sfd.inode.t.ld.setTermios(ctx, io, args) - case linux.TIOCGPTN: - _, err := usermem.CopyObjectOut(ctx, io, args[2].Pointer(), uint32(sfd.inode.t.n), usermem.IOOpts{ - AddressSpaceActive: true, - }) - return 0, err - case linux.TIOCGWINSZ: - return 0, sfd.inode.t.ld.windowSize(ctx, io, args) - case linux.TIOCSWINSZ: - return 0, sfd.inode.t.ld.setWindowSize(ctx, io, args) - case linux.TIOCSCTTY: - // Make the given terminal the controlling terminal of the - // calling process. - return 0, sfd.inode.t.setControllingTTY(ctx, io, args, false /* isMaster */) - case linux.TIOCNOTTY: - // Release this process's controlling terminal. - return 0, sfd.inode.t.releaseControllingTTY(ctx, io, args, false /* isMaster */) - case linux.TIOCGPGRP: - // Get the foreground process group. - return sfd.inode.t.foregroundProcessGroup(ctx, io, args, false /* isMaster */) - case linux.TIOCSPGRP: - // Set the foreground process group. - return sfd.inode.t.setForegroundProcessGroup(ctx, io, args, false /* isMaster */) - default: - maybeEmitUnimplementedEvent(ctx, cmd) - return 0, syserror.ENOTTY - } -} - -// SetStat implements vfs.FileDescriptionImpl.SetStat. -func (sfd *slaveFileDescription) SetStat(ctx context.Context, opts vfs.SetStatOptions) error { - creds := auth.CredentialsFromContext(ctx) - fs := sfd.vfsfd.VirtualDentry().Mount().Filesystem() - return sfd.inode.SetStat(ctx, fs, creds, opts) -} - -// Stat implements vfs.FileDescriptionImpl.Stat. -func (sfd *slaveFileDescription) Stat(ctx context.Context, opts vfs.StatOptions) (linux.Statx, error) { - fs := sfd.vfsfd.VirtualDentry().Mount().Filesystem() - return sfd.inode.Stat(ctx, fs, opts) -} - -// LockPOSIX implements vfs.FileDescriptionImpl.LockPOSIX. -func (sfd *slaveFileDescription) LockPOSIX(ctx context.Context, uid fslock.UniqueID, t fslock.LockType, start, length uint64, whence int16, block fslock.Blocker) error { - return sfd.Locks().LockPOSIX(ctx, &sfd.vfsfd, uid, t, start, length, whence, block) -} - -// UnlockPOSIX implements vfs.FileDescriptionImpl.UnlockPOSIX. -func (sfd *slaveFileDescription) UnlockPOSIX(ctx context.Context, uid fslock.UniqueID, start, length uint64, whence int16) error { - return sfd.Locks().UnlockPOSIX(ctx, &sfd.vfsfd, uid, start, length, whence) -} diff --git a/pkg/sentry/fsimpl/devpts/terminal.go b/pkg/sentry/fsimpl/devpts/terminal.go index 7d2781c54..510bd6d89 100644 --- a/pkg/sentry/fsimpl/devpts/terminal.go +++ b/pkg/sentry/fsimpl/devpts/terminal.go @@ -17,9 +17,9 @@ package devpts import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/kernel" - "gvisor.dev/gvisor/pkg/usermem" ) // Terminal is a pseudoterminal. @@ -36,25 +36,25 @@ type Terminal struct { // this terminal. This field is immutable. masterKTTY *kernel.TTY - // slaveKTTY contains the controlling process of the slave end of this + // replicaKTTY contains the controlling process of the replica end of this // terminal. This field is immutable. - slaveKTTY *kernel.TTY + replicaKTTY *kernel.TTY } func newTerminal(n uint32) *Terminal { - termios := linux.DefaultSlaveTermios + termios := linux.DefaultReplicaTermios t := Terminal{ - n: n, - ld: newLineDiscipline(termios), - masterKTTY: &kernel.TTY{Index: n}, - slaveKTTY: &kernel.TTY{Index: n}, + n: n, + ld: newLineDiscipline(termios), + masterKTTY: &kernel.TTY{Index: n}, + replicaKTTY: &kernel.TTY{Index: n}, } return &t } // setControllingTTY makes tm the controlling terminal of the calling thread // group. -func (tm *Terminal) setControllingTTY(ctx context.Context, io usermem.IO, args arch.SyscallArguments, isMaster bool) error { +func (tm *Terminal) setControllingTTY(ctx context.Context, args arch.SyscallArguments, isMaster bool) error { task := kernel.TaskFromContext(ctx) if task == nil { panic("setControllingTTY must be called from a task context") @@ -65,7 +65,7 @@ func (tm *Terminal) setControllingTTY(ctx context.Context, io usermem.IO, args a // releaseControllingTTY removes tm as the controlling terminal of the calling // thread group. -func (tm *Terminal) releaseControllingTTY(ctx context.Context, io usermem.IO, args arch.SyscallArguments, isMaster bool) error { +func (tm *Terminal) releaseControllingTTY(ctx context.Context, args arch.SyscallArguments, isMaster bool) error { task := kernel.TaskFromContext(ctx) if task == nil { panic("releaseControllingTTY must be called from a task context") @@ -75,7 +75,7 @@ func (tm *Terminal) releaseControllingTTY(ctx context.Context, io usermem.IO, ar } // foregroundProcessGroup gets the process group ID of tm's foreground process. -func (tm *Terminal) foregroundProcessGroup(ctx context.Context, io usermem.IO, args arch.SyscallArguments, isMaster bool) (uintptr, error) { +func (tm *Terminal) foregroundProcessGroup(ctx context.Context, args arch.SyscallArguments, isMaster bool) (uintptr, error) { task := kernel.TaskFromContext(ctx) if task == nil { panic("foregroundProcessGroup must be called from a task context") @@ -87,24 +87,21 @@ func (tm *Terminal) foregroundProcessGroup(ctx context.Context, io usermem.IO, a } // Write it out to *arg. - _, err = usermem.CopyObjectOut(ctx, io, args[2].Pointer(), int32(ret), usermem.IOOpts{ - AddressSpaceActive: true, - }) + retP := primitive.Int32(ret) + _, err = retP.CopyOut(task, args[2].Pointer()) return 0, err } // foregroundProcessGroup sets tm's foreground process. -func (tm *Terminal) setForegroundProcessGroup(ctx context.Context, io usermem.IO, args arch.SyscallArguments, isMaster bool) (uintptr, error) { +func (tm *Terminal) setForegroundProcessGroup(ctx context.Context, args arch.SyscallArguments, isMaster bool) (uintptr, error) { task := kernel.TaskFromContext(ctx) if task == nil { panic("setForegroundProcessGroup must be called from a task context") } // Read in the process group ID. - var pgid int32 - if _, err := usermem.CopyObjectIn(ctx, io, args[2].Pointer(), &pgid, usermem.IOOpts{ - AddressSpaceActive: true, - }); err != nil { + var pgid primitive.Int32 + if _, err := pgid.CopyIn(task, args[2].Pointer()); err != nil { return 0, err } @@ -116,5 +113,5 @@ func (tm *Terminal) tty(isMaster bool) *kernel.TTY { if isMaster { return tm.masterKTTY } - return tm.slaveKTTY + return tm.replicaKTTY } diff --git a/pkg/sentry/fsimpl/devtmpfs/devtmpfs.go b/pkg/sentry/fsimpl/devtmpfs/devtmpfs.go index 52f44f66d..6d1753080 100644 --- a/pkg/sentry/fsimpl/devtmpfs/devtmpfs.go +++ b/pkg/sentry/fsimpl/devtmpfs/devtmpfs.go @@ -33,8 +33,10 @@ import ( const Name = "devtmpfs" // FilesystemType implements vfs.FilesystemType. +// +// +stateify savable type FilesystemType struct { - initOnce sync.Once + initOnce sync.Once `state:"nosave"` // FIXME(gvisor.dev/issue/1664): not yet supported. initErr error // fs is the tmpfs filesystem that backs all mounts of this FilesystemType. @@ -80,7 +82,7 @@ type Accessor struct { // NewAccessor returns an Accessor that supports creation of device special // files in the devtmpfs instance registered with name fsTypeName in vfsObj. func NewAccessor(ctx context.Context, vfsObj *vfs.VirtualFilesystem, creds *auth.Credentials, fsTypeName string) (*Accessor, error) { - mntns, err := vfsObj.NewMountNamespace(ctx, creds, "devtmpfs" /* source */, fsTypeName, &vfs.GetFilesystemOptions{}) + mntns, err := vfsObj.NewMountNamespace(ctx, creds, "devtmpfs" /* source */, fsTypeName, &vfs.MountOptions{}) if err != nil { return nil, err } diff --git a/pkg/sentry/fsimpl/devtmpfs/devtmpfs_test.go b/pkg/sentry/fsimpl/devtmpfs/devtmpfs_test.go index 827a608cb..3a38b8bb4 100644 --- a/pkg/sentry/fsimpl/devtmpfs/devtmpfs_test.go +++ b/pkg/sentry/fsimpl/devtmpfs/devtmpfs_test.go @@ -48,7 +48,7 @@ func setupDevtmpfs(t *testing.T) (context.Context, *auth.Credentials, *vfs.Virtu }) // Create a test mount namespace with devtmpfs mounted at "/dev". - mntns, err := vfsObj.NewMountNamespace(ctx, creds, "tmpfs" /* source */, "tmpfs" /* fsTypeName */, &vfs.GetFilesystemOptions{}) + mntns, err := vfsObj.NewMountNamespace(ctx, creds, "tmpfs" /* source */, "tmpfs" /* fsTypeName */, &vfs.MountOptions{}) if err != nil { t.Fatalf("failed to create tmpfs root mount: %v", err) } diff --git a/pkg/sentry/fsimpl/eventfd/eventfd.go b/pkg/sentry/fsimpl/eventfd/eventfd.go index 812171fa3..1c27ad700 100644 --- a/pkg/sentry/fsimpl/eventfd/eventfd.go +++ b/pkg/sentry/fsimpl/eventfd/eventfd.go @@ -30,9 +30,11 @@ import ( "gvisor.dev/gvisor/pkg/waiter" ) -// EventFileDescription implements FileDescriptionImpl for file-based event +// EventFileDescription implements vfs.FileDescriptionImpl for file-based event // notification (eventfd). Eventfds are usually internal to the Sentry but in // certain situations they may be converted into a host-backed eventfd. +// +// +stateify savable type EventFileDescription struct { vfsfd vfs.FileDescription vfs.FileDescriptionDefaultImpl @@ -106,7 +108,7 @@ func (efd *EventFileDescription) HostFD() (int, error) { return efd.hostfd, nil } -// Release implements FileDescriptionImpl.Release() +// Release implements vfs.FileDescriptionImpl.Release. func (efd *EventFileDescription) Release(context.Context) { efd.mu.Lock() defer efd.mu.Unlock() @@ -119,7 +121,7 @@ func (efd *EventFileDescription) Release(context.Context) { } } -// Read implements FileDescriptionImpl.Read. +// Read implements vfs.FileDescriptionImpl.Read. func (efd *EventFileDescription) Read(ctx context.Context, dst usermem.IOSequence, _ vfs.ReadOptions) (int64, error) { if dst.NumBytes() < 8 { return 0, syscall.EINVAL @@ -130,7 +132,7 @@ func (efd *EventFileDescription) Read(ctx context.Context, dst usermem.IOSequenc return 8, nil } -// Write implements FileDescriptionImpl.Write. +// Write implements vfs.FileDescriptionImpl.Write. func (efd *EventFileDescription) Write(ctx context.Context, src usermem.IOSequence, _ vfs.WriteOptions) (int64, error) { if src.NumBytes() < 8 { return 0, syscall.EINVAL diff --git a/pkg/sentry/fsimpl/ext/BUILD b/pkg/sentry/fsimpl/ext/BUILD index abc610ef3..7b1eec3da 100644 --- a/pkg/sentry/fsimpl/ext/BUILD +++ b/pkg/sentry/fsimpl/ext/BUILD @@ -51,6 +51,8 @@ go_library( "//pkg/fd", "//pkg/fspath", "//pkg/log", + "//pkg/marshal", + "//pkg/marshal/primitive", "//pkg/safemem", "//pkg/sentry/arch", "//pkg/sentry/fs", @@ -86,9 +88,9 @@ go_test( library = ":ext", deps = [ "//pkg/abi/linux", - "//pkg/binary", "//pkg/context", "//pkg/fspath", + "//pkg/marshal/primitive", "//pkg/sentry/contexttest", "//pkg/sentry/fsimpl/ext/disklayout", "//pkg/sentry/kernel/auth", diff --git a/pkg/sentry/fsimpl/ext/benchmark/benchmark_test.go b/pkg/sentry/fsimpl/ext/benchmark/benchmark_test.go index a2cc9b59f..c349b886e 100644 --- a/pkg/sentry/fsimpl/ext/benchmark/benchmark_test.go +++ b/pkg/sentry/fsimpl/ext/benchmark/benchmark_test.go @@ -59,7 +59,11 @@ func setUp(b *testing.B, imagePath string) (context.Context, *vfs.VirtualFilesys vfsObj.MustRegisterFilesystemType("extfs", ext.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{ AllowUserMount: true, }) - mntns, err := vfsObj.NewMountNamespace(ctx, creds, imagePath, "extfs", &vfs.GetFilesystemOptions{InternalData: int(f.Fd())}) + mntns, err := vfsObj.NewMountNamespace(ctx, creds, imagePath, "extfs", &vfs.MountOptions{ + GetFilesystemOptions: vfs.GetFilesystemOptions{ + InternalData: int(f.Fd()), + }, + }) if err != nil { f.Close() return nil, nil, nil, nil, err diff --git a/pkg/sentry/fsimpl/ext/block_map_file.go b/pkg/sentry/fsimpl/ext/block_map_file.go index 8bb104ff0..1165234f9 100644 --- a/pkg/sentry/fsimpl/ext/block_map_file.go +++ b/pkg/sentry/fsimpl/ext/block_map_file.go @@ -18,7 +18,7 @@ import ( "io" "math" - "gvisor.dev/gvisor/pkg/binary" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/syserror" ) @@ -34,19 +34,19 @@ type blockMapFile struct { // directBlks are the direct blocks numbers. The physical blocks pointed by // these holds file data. Contains file blocks 0 to 11. - directBlks [numDirectBlks]uint32 + directBlks [numDirectBlks]primitive.Uint32 // indirectBlk is the physical block which contains (blkSize/4) direct block // numbers (as uint32 integers). - indirectBlk uint32 + indirectBlk primitive.Uint32 // doubleIndirectBlk is the physical block which contains (blkSize/4) indirect // block numbers (as uint32 integers). - doubleIndirectBlk uint32 + doubleIndirectBlk primitive.Uint32 // tripleIndirectBlk is the physical block which contains (blkSize/4) doubly // indirect block numbers (as uint32 integers). - tripleIndirectBlk uint32 + tripleIndirectBlk primitive.Uint32 // coverage at (i)th index indicates the amount of file data a node at // height (i) covers. Height 0 is the direct block. @@ -68,10 +68,12 @@ func newBlockMapFile(args inodeArgs) (*blockMapFile, error) { } blkMap := file.regFile.inode.diskInode.Data() - binary.Unmarshal(blkMap[:numDirectBlks*4], binary.LittleEndian, &file.directBlks) - binary.Unmarshal(blkMap[numDirectBlks*4:(numDirectBlks+1)*4], binary.LittleEndian, &file.indirectBlk) - binary.Unmarshal(blkMap[(numDirectBlks+1)*4:(numDirectBlks+2)*4], binary.LittleEndian, &file.doubleIndirectBlk) - binary.Unmarshal(blkMap[(numDirectBlks+2)*4:(numDirectBlks+3)*4], binary.LittleEndian, &file.tripleIndirectBlk) + for i := 0; i < numDirectBlks; i++ { + file.directBlks[i].UnmarshalBytes(blkMap[i*4 : (i+1)*4]) + } + file.indirectBlk.UnmarshalBytes(blkMap[numDirectBlks*4 : (numDirectBlks+1)*4]) + file.doubleIndirectBlk.UnmarshalBytes(blkMap[(numDirectBlks+1)*4 : (numDirectBlks+2)*4]) + file.tripleIndirectBlk.UnmarshalBytes(blkMap[(numDirectBlks+2)*4 : (numDirectBlks+3)*4]) return file, nil } @@ -117,16 +119,16 @@ func (f *blockMapFile) ReadAt(dst []byte, off int64) (int, error) { switch { case offset < dirBlksEnd: // Direct block. - curR, err = f.read(f.directBlks[offset/f.regFile.inode.blkSize], offset%f.regFile.inode.blkSize, 0, dst[read:]) + curR, err = f.read(uint32(f.directBlks[offset/f.regFile.inode.blkSize]), offset%f.regFile.inode.blkSize, 0, dst[read:]) case offset < indirBlkEnd: // Indirect block. - curR, err = f.read(f.indirectBlk, offset-dirBlksEnd, 1, dst[read:]) + curR, err = f.read(uint32(f.indirectBlk), offset-dirBlksEnd, 1, dst[read:]) case offset < doubIndirBlkEnd: // Doubly indirect block. - curR, err = f.read(f.doubleIndirectBlk, offset-indirBlkEnd, 2, dst[read:]) + curR, err = f.read(uint32(f.doubleIndirectBlk), offset-indirBlkEnd, 2, dst[read:]) default: // Triply indirect block. - curR, err = f.read(f.tripleIndirectBlk, offset-doubIndirBlkEnd, 3, dst[read:]) + curR, err = f.read(uint32(f.tripleIndirectBlk), offset-doubIndirBlkEnd, 3, dst[read:]) } read += curR @@ -174,13 +176,13 @@ func (f *blockMapFile) read(curPhyBlk uint32, relFileOff uint64, height uint, ds read := 0 curChildOff := relFileOff % childCov for i := startIdx; i < endIdx; i++ { - var childPhyBlk uint32 + var childPhyBlk primitive.Uint32 err := readFromDisk(f.regFile.inode.fs.dev, curPhyBlkOff+int64(i*4), &childPhyBlk) if err != nil { return read, err } - n, err := f.read(childPhyBlk, curChildOff, height-1, dst[read:]) + n, err := f.read(uint32(childPhyBlk), curChildOff, height-1, dst[read:]) read += n if err != nil { return read, err diff --git a/pkg/sentry/fsimpl/ext/block_map_test.go b/pkg/sentry/fsimpl/ext/block_map_test.go index 6fa84e7aa..ed98b482e 100644 --- a/pkg/sentry/fsimpl/ext/block_map_test.go +++ b/pkg/sentry/fsimpl/ext/block_map_test.go @@ -20,7 +20,7 @@ import ( "testing" "github.com/google/go-cmp/cmp" - "gvisor.dev/gvisor/pkg/binary" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/fsimpl/ext/disklayout" ) @@ -87,29 +87,33 @@ func blockMapSetUp(t *testing.T) (*blockMapFile, []byte) { mockDisk := make([]byte, mockBMDiskSize) var fileData []byte blkNums := newBlkNumGen() - var data []byte + off := 0 + data := make([]byte, (numDirectBlks+3)*(*primitive.Uint32)(nil).SizeBytes()) // Write the direct blocks. for i := 0; i < numDirectBlks; i++ { - curBlkNum := blkNums.next() - data = binary.Marshal(data, binary.LittleEndian, curBlkNum) - fileData = append(fileData, writeFileDataToBlock(mockDisk, curBlkNum, 0, blkNums)...) + curBlkNum := primitive.Uint32(blkNums.next()) + curBlkNum.MarshalBytes(data[off:]) + off += curBlkNum.SizeBytes() + fileData = append(fileData, writeFileDataToBlock(mockDisk, uint32(curBlkNum), 0, blkNums)...) } // Write to indirect block. - indirectBlk := blkNums.next() - data = binary.Marshal(data, binary.LittleEndian, indirectBlk) - fileData = append(fileData, writeFileDataToBlock(mockDisk, indirectBlk, 1, blkNums)...) - - // Write to indirect block. - doublyIndirectBlk := blkNums.next() - data = binary.Marshal(data, binary.LittleEndian, doublyIndirectBlk) - fileData = append(fileData, writeFileDataToBlock(mockDisk, doublyIndirectBlk, 2, blkNums)...) - - // Write to indirect block. - triplyIndirectBlk := blkNums.next() - data = binary.Marshal(data, binary.LittleEndian, triplyIndirectBlk) - fileData = append(fileData, writeFileDataToBlock(mockDisk, triplyIndirectBlk, 3, blkNums)...) + indirectBlk := primitive.Uint32(blkNums.next()) + indirectBlk.MarshalBytes(data[off:]) + off += indirectBlk.SizeBytes() + fileData = append(fileData, writeFileDataToBlock(mockDisk, uint32(indirectBlk), 1, blkNums)...) + + // Write to double indirect block. + doublyIndirectBlk := primitive.Uint32(blkNums.next()) + doublyIndirectBlk.MarshalBytes(data[off:]) + off += doublyIndirectBlk.SizeBytes() + fileData = append(fileData, writeFileDataToBlock(mockDisk, uint32(doublyIndirectBlk), 2, blkNums)...) + + // Write to triple indirect block. + triplyIndirectBlk := primitive.Uint32(blkNums.next()) + triplyIndirectBlk.MarshalBytes(data[off:]) + fileData = append(fileData, writeFileDataToBlock(mockDisk, uint32(triplyIndirectBlk), 3, blkNums)...) args := inodeArgs{ fs: &filesystem{ @@ -142,9 +146,9 @@ func writeFileDataToBlock(disk []byte, blkNum uint32, height uint, blkNums *blkN var fileData []byte for off := blkNum * mockBMBlkSize; off < (blkNum+1)*mockBMBlkSize; off += 4 { - curBlkNum := blkNums.next() - copy(disk[off:off+4], binary.Marshal(nil, binary.LittleEndian, curBlkNum)) - fileData = append(fileData, writeFileDataToBlock(disk, curBlkNum, height-1, blkNums)...) + curBlkNum := primitive.Uint32(blkNums.next()) + curBlkNum.MarshalBytes(disk[off : off+4]) + fileData = append(fileData, writeFileDataToBlock(disk, uint32(curBlkNum), height-1, blkNums)...) } return fileData } diff --git a/pkg/sentry/fsimpl/ext/dentry.go b/pkg/sentry/fsimpl/ext/dentry.go index 7a1b4219f..9bfed883a 100644 --- a/pkg/sentry/fsimpl/ext/dentry.go +++ b/pkg/sentry/fsimpl/ext/dentry.go @@ -20,6 +20,8 @@ import ( ) // dentry implements vfs.DentryImpl. +// +// +stateify savable type dentry struct { vfsd vfs.Dentry diff --git a/pkg/sentry/fsimpl/ext/directory.go b/pkg/sentry/fsimpl/ext/directory.go index 0fc01668d..0ad79b381 100644 --- a/pkg/sentry/fsimpl/ext/directory.go +++ b/pkg/sentry/fsimpl/ext/directory.go @@ -16,7 +16,6 @@ package ext import ( "gvisor.dev/gvisor/pkg/abi/linux" - "gvisor.dev/gvisor/pkg/binary" "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/log" "gvisor.dev/gvisor/pkg/sentry/fs" @@ -28,6 +27,8 @@ import ( ) // directory represents a directory inode. It holds the childList in memory. +// +// +stateify savable type directory struct { inode inode @@ -39,7 +40,7 @@ type directory struct { // Lock Order (outermost locks must be taken first): // directory.mu // filesystem.mu - mu sync.Mutex + mu sync.Mutex `state:"nosave"` // childList is a list containing (1) child dirents and (2) fake dirents // (with diskDirent == nil) that represent the iteration position of @@ -98,7 +99,7 @@ func newDirectory(args inodeArgs, newDirent bool) (*directory, error) { } else { curDirent.diskDirent = &disklayout.DirentOld{} } - binary.Unmarshal(buf, binary.LittleEndian, curDirent.diskDirent) + curDirent.diskDirent.UnmarshalBytes(buf) if curDirent.diskDirent.Inode() != 0 && len(curDirent.diskDirent.FileName()) != 0 { // Inode number and name length fields being set to 0 is used to indicate @@ -120,6 +121,8 @@ func (i *inode) isDir() bool { } // dirent is the directory.childList node. +// +// +stateify savable type dirent struct { diskDirent disklayout.Dirent @@ -129,6 +132,8 @@ type dirent struct { // directoryFD represents a directory file description. It implements // vfs.FileDescriptionImpl. +// +// +stateify savable type directoryFD struct { fileDescription vfs.DirectoryFileDescriptionDefaultImpl diff --git a/pkg/sentry/fsimpl/ext/disklayout/BUILD b/pkg/sentry/fsimpl/ext/disklayout/BUILD index 9bd9c76c0..d98a05dd8 100644 --- a/pkg/sentry/fsimpl/ext/disklayout/BUILD +++ b/pkg/sentry/fsimpl/ext/disklayout/BUILD @@ -22,10 +22,11 @@ go_library( "superblock_old.go", "test_utils.go", ], + marshal = True, visibility = ["//pkg/sentry:internal"], deps = [ "//pkg/abi/linux", - "//pkg/binary", + "//pkg/marshal", "//pkg/sentry/fs", "//pkg/sentry/kernel/auth", "//pkg/sentry/kernel/time", diff --git a/pkg/sentry/fsimpl/ext/disklayout/block_group.go b/pkg/sentry/fsimpl/ext/disklayout/block_group.go index ad6f4fef8..0d56ae9da 100644 --- a/pkg/sentry/fsimpl/ext/disklayout/block_group.go +++ b/pkg/sentry/fsimpl/ext/disklayout/block_group.go @@ -14,6 +14,10 @@ package disklayout +import ( + "gvisor.dev/gvisor/pkg/marshal" +) + // BlockGroup represents a Linux ext block group descriptor. An ext file system // is split into a series of block groups. This provides an access layer to // information needed to access and use a block group. @@ -30,6 +34,8 @@ package disklayout // // See https://www.kernel.org/doc/html/latest/filesystems/ext4/globals.html#block-group-descriptors. type BlockGroup interface { + marshal.Marshallable + // InodeTable returns the absolute block number of the block containing the // inode table. This points to an array of Inode structs. Inode tables are // statically allocated at mkfs time. The superblock records the number of diff --git a/pkg/sentry/fsimpl/ext/disklayout/block_group_32.go b/pkg/sentry/fsimpl/ext/disklayout/block_group_32.go index 3e16c76db..a35fa22a0 100644 --- a/pkg/sentry/fsimpl/ext/disklayout/block_group_32.go +++ b/pkg/sentry/fsimpl/ext/disklayout/block_group_32.go @@ -17,6 +17,8 @@ package disklayout // BlockGroup32Bit emulates the first half of struct ext4_group_desc in // fs/ext4/ext4.h. It is the block group descriptor struct for ext2, ext3 and // 32-bit ext4 filesystems. It implements BlockGroup interface. +// +// +marshal type BlockGroup32Bit struct { BlockBitmapLo uint32 InodeBitmapLo uint32 diff --git a/pkg/sentry/fsimpl/ext/disklayout/block_group_64.go b/pkg/sentry/fsimpl/ext/disklayout/block_group_64.go index 9a809197a..d54d1d345 100644 --- a/pkg/sentry/fsimpl/ext/disklayout/block_group_64.go +++ b/pkg/sentry/fsimpl/ext/disklayout/block_group_64.go @@ -18,6 +18,8 @@ package disklayout // It is the block group descriptor struct for 64-bit ext4 filesystems. // It implements BlockGroup interface. It is an extension of the 32-bit // version of BlockGroup. +// +// +marshal type BlockGroup64Bit struct { // We embed the 32-bit struct here because 64-bit version is just an extension // of the 32-bit version. diff --git a/pkg/sentry/fsimpl/ext/disklayout/block_group_test.go b/pkg/sentry/fsimpl/ext/disklayout/block_group_test.go index 0ef4294c0..e4ce484e4 100644 --- a/pkg/sentry/fsimpl/ext/disklayout/block_group_test.go +++ b/pkg/sentry/fsimpl/ext/disklayout/block_group_test.go @@ -21,6 +21,8 @@ import ( // TestBlockGroupSize tests that the block group descriptor structs are of the // correct size. func TestBlockGroupSize(t *testing.T) { - assertSize(t, BlockGroup32Bit{}, 32) - assertSize(t, BlockGroup64Bit{}, 64) + var bgSmall BlockGroup32Bit + assertSize(t, &bgSmall, 32) + var bgBig BlockGroup64Bit + assertSize(t, &bgBig, 64) } diff --git a/pkg/sentry/fsimpl/ext/disklayout/dirent.go b/pkg/sentry/fsimpl/ext/disklayout/dirent.go index 417b6cf65..568c8cb4c 100644 --- a/pkg/sentry/fsimpl/ext/disklayout/dirent.go +++ b/pkg/sentry/fsimpl/ext/disklayout/dirent.go @@ -15,6 +15,7 @@ package disklayout import ( + "gvisor.dev/gvisor/pkg/marshal" "gvisor.dev/gvisor/pkg/sentry/fs" ) @@ -51,6 +52,8 @@ var ( // // See https://www.kernel.org/doc/html/latest/filesystems/ext4/dynamic.html#linear-classic-directories. type Dirent interface { + marshal.Marshallable + // Inode returns the absolute inode number of the underlying inode. // Inode number 0 signifies an unused dirent. Inode() uint32 diff --git a/pkg/sentry/fsimpl/ext/disklayout/dirent_new.go b/pkg/sentry/fsimpl/ext/disklayout/dirent_new.go index 29ae4a5c2..51f9c2946 100644 --- a/pkg/sentry/fsimpl/ext/disklayout/dirent_new.go +++ b/pkg/sentry/fsimpl/ext/disklayout/dirent_new.go @@ -29,12 +29,14 @@ import ( // Note: This struct can be of variable size on disk. The one described below // is of maximum size and the FileName beyond NameLength bytes might contain // garbage. +// +// +marshal type DirentNew struct { InodeNumber uint32 RecordLength uint16 NameLength uint8 FileTypeRaw uint8 - FileNameRaw [MaxFileName]byte + FileNameRaw [MaxFileName]byte `marshal:"unaligned"` } // Compiles only if DirentNew implements Dirent. diff --git a/pkg/sentry/fsimpl/ext/disklayout/dirent_old.go b/pkg/sentry/fsimpl/ext/disklayout/dirent_old.go index 6fff12a6e..d4b19e086 100644 --- a/pkg/sentry/fsimpl/ext/disklayout/dirent_old.go +++ b/pkg/sentry/fsimpl/ext/disklayout/dirent_old.go @@ -22,11 +22,13 @@ import "gvisor.dev/gvisor/pkg/sentry/fs" // Note: This struct can be of variable size on disk. The one described below // is of maximum size and the FileName beyond NameLength bytes might contain // garbage. +// +// +marshal type DirentOld struct { InodeNumber uint32 RecordLength uint16 NameLength uint16 - FileNameRaw [MaxFileName]byte + FileNameRaw [MaxFileName]byte `marshal:"unaligned"` } // Compiles only if DirentOld implements Dirent. diff --git a/pkg/sentry/fsimpl/ext/disklayout/dirent_test.go b/pkg/sentry/fsimpl/ext/disklayout/dirent_test.go index 934919f8a..3486864dc 100644 --- a/pkg/sentry/fsimpl/ext/disklayout/dirent_test.go +++ b/pkg/sentry/fsimpl/ext/disklayout/dirent_test.go @@ -21,6 +21,8 @@ import ( // TestDirentSize tests that the dirent structs are of the correct // size. func TestDirentSize(t *testing.T) { - assertSize(t, DirentOld{}, uintptr(DirentSize)) - assertSize(t, DirentNew{}, uintptr(DirentSize)) + var dOld DirentOld + assertSize(t, &dOld, DirentSize) + var dNew DirentNew + assertSize(t, &dNew, DirentSize) } diff --git a/pkg/sentry/fsimpl/ext/disklayout/disklayout.go b/pkg/sentry/fsimpl/ext/disklayout/disklayout.go index bdf4e2132..0834e9ba8 100644 --- a/pkg/sentry/fsimpl/ext/disklayout/disklayout.go +++ b/pkg/sentry/fsimpl/ext/disklayout/disklayout.go @@ -36,8 +36,6 @@ // escape analysis on an unknown implementation at compile time. // // Notes: -// - All fields in these structs are exported because binary.Read would -// panic otherwise. // - All structures on disk are in little-endian order. Only jbd2 (journal) // structures are in big-endian order. // - All OS dependent fields in these structures will be interpretted using diff --git a/pkg/sentry/fsimpl/ext/disklayout/extent.go b/pkg/sentry/fsimpl/ext/disklayout/extent.go index 4110649ab..b13999bfc 100644 --- a/pkg/sentry/fsimpl/ext/disklayout/extent.go +++ b/pkg/sentry/fsimpl/ext/disklayout/extent.go @@ -14,6 +14,10 @@ package disklayout +import ( + "gvisor.dev/gvisor/pkg/marshal" +) + // Extents were introduced in ext4 and provide huge performance gains in terms // data locality and reduced metadata block usage. Extents are organized in // extent trees. The root node is contained in inode.BlocksRaw. @@ -64,6 +68,8 @@ type ExtentNode struct { // ExtentEntry represents an extent tree node entry. The entry can either be // an ExtentIdx or Extent itself. This exists to simplify navigation logic. type ExtentEntry interface { + marshal.Marshallable + // FileBlock returns the first file block number covered by this entry. FileBlock() uint32 @@ -75,6 +81,8 @@ type ExtentEntry interface { // tree node begins with this and is followed by `NumEntries` number of: // - Extent if `Depth` == 0 // - ExtentIdx otherwise +// +// +marshal type ExtentHeader struct { // Magic in the extent magic number, must be 0xf30a. Magic uint16 @@ -96,6 +104,8 @@ type ExtentHeader struct { // internal nodes. Sorted in ascending order based on FirstFileBlock since // Linux does a binary search on this. This points to a block containing the // child node. +// +// +marshal type ExtentIdx struct { FirstFileBlock uint32 ChildBlockLo uint32 @@ -121,6 +131,8 @@ func (ei *ExtentIdx) PhysicalBlock() uint64 { // nodes. Sorted in ascending order based on FirstFileBlock since Linux does a // binary search on this. This points to an array of data blocks containing the // file data. It covers `Length` data blocks starting from `StartBlock`. +// +// +marshal type Extent struct { FirstFileBlock uint32 Length uint16 diff --git a/pkg/sentry/fsimpl/ext/disklayout/extent_test.go b/pkg/sentry/fsimpl/ext/disklayout/extent_test.go index 8762b90db..c96002e19 100644 --- a/pkg/sentry/fsimpl/ext/disklayout/extent_test.go +++ b/pkg/sentry/fsimpl/ext/disklayout/extent_test.go @@ -21,7 +21,10 @@ import ( // TestExtentSize tests that the extent structs are of the correct // size. func TestExtentSize(t *testing.T) { - assertSize(t, ExtentHeader{}, ExtentHeaderSize) - assertSize(t, ExtentIdx{}, ExtentEntrySize) - assertSize(t, Extent{}, ExtentEntrySize) + var h ExtentHeader + assertSize(t, &h, ExtentHeaderSize) + var i ExtentIdx + assertSize(t, &i, ExtentEntrySize) + var e Extent + assertSize(t, &e, ExtentEntrySize) } diff --git a/pkg/sentry/fsimpl/ext/disklayout/inode.go b/pkg/sentry/fsimpl/ext/disklayout/inode.go index 88ae913f5..ef25040a9 100644 --- a/pkg/sentry/fsimpl/ext/disklayout/inode.go +++ b/pkg/sentry/fsimpl/ext/disklayout/inode.go @@ -16,6 +16,7 @@ package disklayout import ( "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/marshal" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/sentry/kernel/time" ) @@ -38,6 +39,8 @@ const ( // // See https://www.kernel.org/doc/html/latest/filesystems/ext4/dynamic.html#index-nodes. type Inode interface { + marshal.Marshallable + // Mode returns the linux file mode which is majorly used to extract // information like: // - File permissions (read/write/execute by user/group/others). diff --git a/pkg/sentry/fsimpl/ext/disklayout/inode_new.go b/pkg/sentry/fsimpl/ext/disklayout/inode_new.go index 8f9f574ce..a4503f5cf 100644 --- a/pkg/sentry/fsimpl/ext/disklayout/inode_new.go +++ b/pkg/sentry/fsimpl/ext/disklayout/inode_new.go @@ -27,6 +27,8 @@ import "gvisor.dev/gvisor/pkg/sentry/kernel/time" // are used to provide nanoscond precision. Hence, these timestamps will now // overflow in May 2446. // See https://www.kernel.org/doc/html/latest/filesystems/ext4/dynamic.html#inode-timestamps. +// +// +marshal type InodeNew struct { InodeOld diff --git a/pkg/sentry/fsimpl/ext/disklayout/inode_old.go b/pkg/sentry/fsimpl/ext/disklayout/inode_old.go index db25b11b6..e6b28babf 100644 --- a/pkg/sentry/fsimpl/ext/disklayout/inode_old.go +++ b/pkg/sentry/fsimpl/ext/disklayout/inode_old.go @@ -30,6 +30,8 @@ const ( // // All fields representing time are in seconds since the epoch. Which means that // they will overflow in January 2038. +// +// +marshal type InodeOld struct { ModeRaw uint16 UIDLo uint16 diff --git a/pkg/sentry/fsimpl/ext/disklayout/inode_test.go b/pkg/sentry/fsimpl/ext/disklayout/inode_test.go index dd03ee50e..90744e956 100644 --- a/pkg/sentry/fsimpl/ext/disklayout/inode_test.go +++ b/pkg/sentry/fsimpl/ext/disklayout/inode_test.go @@ -24,10 +24,12 @@ import ( // TestInodeSize tests that the inode structs are of the correct size. func TestInodeSize(t *testing.T) { - assertSize(t, InodeOld{}, OldInodeSize) + var iOld InodeOld + assertSize(t, &iOld, OldInodeSize) // This was updated from 156 bytes to 160 bytes in Oct 2015. - assertSize(t, InodeNew{}, 160) + var iNew InodeNew + assertSize(t, &iNew, 160) } // TestTimestampSeconds tests that the seconds part of [a/c/m] timestamps in diff --git a/pkg/sentry/fsimpl/ext/disklayout/superblock.go b/pkg/sentry/fsimpl/ext/disklayout/superblock.go index 8bb327006..70948ebe9 100644 --- a/pkg/sentry/fsimpl/ext/disklayout/superblock.go +++ b/pkg/sentry/fsimpl/ext/disklayout/superblock.go @@ -14,6 +14,10 @@ package disklayout +import ( + "gvisor.dev/gvisor/pkg/marshal" +) + const ( // SbOffset is the absolute offset at which the superblock is placed. SbOffset = 1024 @@ -38,6 +42,8 @@ const ( // // See https://www.kernel.org/doc/html/latest/filesystems/ext4/globals.html#super-block. type SuperBlock interface { + marshal.Marshallable + // InodesCount returns the total number of inodes in this filesystem. InodesCount() uint32 diff --git a/pkg/sentry/fsimpl/ext/disklayout/superblock_32.go b/pkg/sentry/fsimpl/ext/disklayout/superblock_32.go index 53e515fd3..4dc6080fb 100644 --- a/pkg/sentry/fsimpl/ext/disklayout/superblock_32.go +++ b/pkg/sentry/fsimpl/ext/disklayout/superblock_32.go @@ -17,6 +17,8 @@ package disklayout // SuperBlock32Bit implements SuperBlock and represents the 32-bit version of // the ext4_super_block struct in fs/ext4/ext4.h. Should be used only if // RevLevel = DynamicRev and 64-bit feature is disabled. +// +// +marshal type SuperBlock32Bit struct { // We embed the old superblock struct here because the 32-bit version is just // an extension of the old version. diff --git a/pkg/sentry/fsimpl/ext/disklayout/superblock_64.go b/pkg/sentry/fsimpl/ext/disklayout/superblock_64.go index 7c1053fb4..2c9039327 100644 --- a/pkg/sentry/fsimpl/ext/disklayout/superblock_64.go +++ b/pkg/sentry/fsimpl/ext/disklayout/superblock_64.go @@ -19,6 +19,8 @@ package disklayout // 1024 bytes (smallest possible block size) and hence the superblock always // fits in no more than one data block. Should only be used when the 64-bit // feature is set. +// +// +marshal type SuperBlock64Bit struct { // We embed the 32-bit struct here because 64-bit version is just an extension // of the 32-bit version. diff --git a/pkg/sentry/fsimpl/ext/disklayout/superblock_old.go b/pkg/sentry/fsimpl/ext/disklayout/superblock_old.go index 9221e0251..e4709f23c 100644 --- a/pkg/sentry/fsimpl/ext/disklayout/superblock_old.go +++ b/pkg/sentry/fsimpl/ext/disklayout/superblock_old.go @@ -16,6 +16,8 @@ package disklayout // SuperBlockOld implements SuperBlock and represents the old version of the // superblock struct. Should be used only if RevLevel = OldRev. +// +// +marshal type SuperBlockOld struct { InodesCountRaw uint32 BlocksCountLo uint32 diff --git a/pkg/sentry/fsimpl/ext/disklayout/superblock_test.go b/pkg/sentry/fsimpl/ext/disklayout/superblock_test.go index 463b5ba21..b734b6987 100644 --- a/pkg/sentry/fsimpl/ext/disklayout/superblock_test.go +++ b/pkg/sentry/fsimpl/ext/disklayout/superblock_test.go @@ -21,7 +21,10 @@ import ( // TestSuperBlockSize tests that the superblock structs are of the correct // size. func TestSuperBlockSize(t *testing.T) { - assertSize(t, SuperBlockOld{}, 84) - assertSize(t, SuperBlock32Bit{}, 336) - assertSize(t, SuperBlock64Bit{}, 1024) + var sbOld SuperBlockOld + assertSize(t, &sbOld, 84) + var sb32 SuperBlock32Bit + assertSize(t, &sb32, 336) + var sb64 SuperBlock64Bit + assertSize(t, &sb64, 1024) } diff --git a/pkg/sentry/fsimpl/ext/disklayout/test_utils.go b/pkg/sentry/fsimpl/ext/disklayout/test_utils.go index 9c63f04c0..a4bc08411 100644 --- a/pkg/sentry/fsimpl/ext/disklayout/test_utils.go +++ b/pkg/sentry/fsimpl/ext/disklayout/test_utils.go @@ -18,13 +18,13 @@ import ( "reflect" "testing" - "gvisor.dev/gvisor/pkg/binary" + "gvisor.dev/gvisor/pkg/marshal" ) -func assertSize(t *testing.T, v interface{}, want uintptr) { +func assertSize(t *testing.T, v marshal.Marshallable, want int) { t.Helper() - if got := binary.Size(v); got != want { + if got := v.SizeBytes(); got != want { t.Errorf("struct %s should be exactly %d bytes but is %d bytes", reflect.TypeOf(v).Name(), want, got) } } diff --git a/pkg/sentry/fsimpl/ext/ext.go b/pkg/sentry/fsimpl/ext/ext.go index 08ffc2834..aca258d40 100644 --- a/pkg/sentry/fsimpl/ext/ext.go +++ b/pkg/sentry/fsimpl/ext/ext.go @@ -34,6 +34,8 @@ import ( const Name = "ext" // FilesystemType implements vfs.FilesystemType. +// +// +stateify savable type FilesystemType struct{} // Compiles only if FilesystemType implements vfs.FilesystemType. diff --git a/pkg/sentry/fsimpl/ext/ext_test.go b/pkg/sentry/fsimpl/ext/ext_test.go index 2dbaee287..0989558cd 100644 --- a/pkg/sentry/fsimpl/ext/ext_test.go +++ b/pkg/sentry/fsimpl/ext/ext_test.go @@ -71,7 +71,11 @@ func setUp(t *testing.T, imagePath string) (context.Context, *vfs.VirtualFilesys vfsObj.MustRegisterFilesystemType("extfs", FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{ AllowUserMount: true, }) - mntns, err := vfsObj.NewMountNamespace(ctx, creds, localImagePath, "extfs", &vfs.GetFilesystemOptions{InternalData: int(f.Fd())}) + mntns, err := vfsObj.NewMountNamespace(ctx, creds, localImagePath, "extfs", &vfs.MountOptions{ + GetFilesystemOptions: vfs.GetFilesystemOptions{ + InternalData: int(f.Fd()), + }, + }) if err != nil { f.Close() return nil, nil, nil, nil, err diff --git a/pkg/sentry/fsimpl/ext/extent_file.go b/pkg/sentry/fsimpl/ext/extent_file.go index c36225a7c..778460107 100644 --- a/pkg/sentry/fsimpl/ext/extent_file.go +++ b/pkg/sentry/fsimpl/ext/extent_file.go @@ -18,12 +18,13 @@ import ( "io" "sort" - "gvisor.dev/gvisor/pkg/binary" "gvisor.dev/gvisor/pkg/sentry/fsimpl/ext/disklayout" "gvisor.dev/gvisor/pkg/syserror" ) // extentFile is a type of regular file which uses extents to store file data. +// +// +stateify savable type extentFile struct { regFile regularFile @@ -58,7 +59,7 @@ func newExtentFile(args inodeArgs) (*extentFile, error) { func (f *extentFile) buildExtTree() error { rootNodeData := f.regFile.inode.diskInode.Data() - binary.Unmarshal(rootNodeData[:disklayout.ExtentHeaderSize], binary.LittleEndian, &f.root.Header) + f.root.Header.UnmarshalBytes(rootNodeData[:disklayout.ExtentHeaderSize]) // Root node can not have more than 4 entries: 60 bytes = 1 header + 4 entries. if f.root.Header.NumEntries > 4 { @@ -77,7 +78,7 @@ func (f *extentFile) buildExtTree() error { // Internal node. curEntry = &disklayout.ExtentIdx{} } - binary.Unmarshal(rootNodeData[off:off+disklayout.ExtentEntrySize], binary.LittleEndian, curEntry) + curEntry.UnmarshalBytes(rootNodeData[off : off+disklayout.ExtentEntrySize]) f.root.Entries[i].Entry = curEntry } diff --git a/pkg/sentry/fsimpl/ext/extent_test.go b/pkg/sentry/fsimpl/ext/extent_test.go index cd10d46ee..985f76ac0 100644 --- a/pkg/sentry/fsimpl/ext/extent_test.go +++ b/pkg/sentry/fsimpl/ext/extent_test.go @@ -21,7 +21,6 @@ import ( "github.com/google/go-cmp/cmp" "github.com/google/go-cmp/cmp/cmpopts" - "gvisor.dev/gvisor/pkg/binary" "gvisor.dev/gvisor/pkg/sentry/fsimpl/ext/disklayout" ) @@ -202,13 +201,14 @@ func extentTreeSetUp(t *testing.T, root *disklayout.ExtentNode) (*extentFile, [] // writeTree writes the tree represented by `root` to the inode and disk. It // also writes random file data on disk. func writeTree(in *inode, disk []byte, root *disklayout.ExtentNode, mockExtentBlkSize uint64) []byte { - rootData := binary.Marshal(nil, binary.LittleEndian, root.Header) + rootData := in.diskInode.Data() + root.Header.MarshalBytes(rootData) + off := root.Header.SizeBytes() for _, ep := range root.Entries { - rootData = binary.Marshal(rootData, binary.LittleEndian, ep.Entry) + ep.Entry.MarshalBytes(rootData[off:]) + off += ep.Entry.SizeBytes() } - copy(in.diskInode.Data(), rootData) - var fileData []byte for _, ep := range root.Entries { if root.Header.Height == 0 { @@ -223,13 +223,14 @@ func writeTree(in *inode, disk []byte, root *disklayout.ExtentNode, mockExtentBl // writeTreeToDisk is the recursive step for writeTree which writes the tree // on the disk only. Also writes random file data on disk. func writeTreeToDisk(disk []byte, curNode disklayout.ExtentEntryPair) []byte { - nodeData := binary.Marshal(nil, binary.LittleEndian, curNode.Node.Header) + nodeData := disk[curNode.Entry.PhysicalBlock()*mockExtentBlkSize:] + curNode.Node.Header.MarshalBytes(nodeData) + off := curNode.Node.Header.SizeBytes() for _, ep := range curNode.Node.Entries { - nodeData = binary.Marshal(nodeData, binary.LittleEndian, ep.Entry) + ep.Entry.MarshalBytes(nodeData[off:]) + off += ep.Entry.SizeBytes() } - copy(disk[curNode.Entry.PhysicalBlock()*mockExtentBlkSize:], nodeData) - var fileData []byte for _, ep := range curNode.Node.Entries { if curNode.Node.Header.Height == 0 { diff --git a/pkg/sentry/fsimpl/ext/filesystem.go b/pkg/sentry/fsimpl/ext/filesystem.go index 8565d1a66..917f1873d 100644 --- a/pkg/sentry/fsimpl/ext/filesystem.go +++ b/pkg/sentry/fsimpl/ext/filesystem.go @@ -38,11 +38,13 @@ var ( ) // filesystem implements vfs.FilesystemImpl. +// +// +stateify savable type filesystem struct { vfsfs vfs.Filesystem // mu serializes changes to the Dentry tree. - mu sync.RWMutex + mu sync.RWMutex `state:"nosave"` // dev represents the underlying fs device. It does not require protection // because io.ReaderAt permits concurrent read calls to it. It translates to @@ -490,7 +492,7 @@ func (fs *filesystem) UnlinkAt(ctx context.Context, rp *vfs.ResolvingPath) error return syserror.EROFS } -// BoundEndpointAt implements FilesystemImpl.BoundEndpointAt. +// BoundEndpointAt implements vfs.FilesystemImpl.BoundEndpointAt. func (fs *filesystem) BoundEndpointAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.BoundEndpointOptions) (transport.BoundEndpoint, error) { _, inode, err := fs.walk(ctx, rp, false) if err != nil { @@ -504,8 +506,8 @@ func (fs *filesystem) BoundEndpointAt(ctx context.Context, rp *vfs.ResolvingPath return nil, syserror.ECONNREFUSED } -// ListxattrAt implements vfs.FilesystemImpl.ListxattrAt. -func (fs *filesystem) ListxattrAt(ctx context.Context, rp *vfs.ResolvingPath, size uint64) ([]string, error) { +// ListXattrAt implements vfs.FilesystemImpl.ListXattrAt. +func (fs *filesystem) ListXattrAt(ctx context.Context, rp *vfs.ResolvingPath, size uint64) ([]string, error) { _, _, err := fs.walk(ctx, rp, false) if err != nil { return nil, err @@ -513,8 +515,8 @@ func (fs *filesystem) ListxattrAt(ctx context.Context, rp *vfs.ResolvingPath, si return nil, syserror.ENOTSUP } -// GetxattrAt implements vfs.FilesystemImpl.GetxattrAt. -func (fs *filesystem) GetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.GetxattrOptions) (string, error) { +// GetXattrAt implements vfs.FilesystemImpl.GetXattrAt. +func (fs *filesystem) GetXattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.GetXattrOptions) (string, error) { _, _, err := fs.walk(ctx, rp, false) if err != nil { return "", err @@ -522,8 +524,8 @@ func (fs *filesystem) GetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opt return "", syserror.ENOTSUP } -// SetxattrAt implements vfs.FilesystemImpl.SetxattrAt. -func (fs *filesystem) SetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.SetxattrOptions) error { +// SetXattrAt implements vfs.FilesystemImpl.SetXattrAt. +func (fs *filesystem) SetXattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.SetXattrOptions) error { _, _, err := fs.walk(ctx, rp, false) if err != nil { return err @@ -531,8 +533,8 @@ func (fs *filesystem) SetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opt return syserror.ENOTSUP } -// RemovexattrAt implements vfs.FilesystemImpl.RemovexattrAt. -func (fs *filesystem) RemovexattrAt(ctx context.Context, rp *vfs.ResolvingPath, name string) error { +// RemoveXattrAt implements vfs.FilesystemImpl.RemoveXattrAt. +func (fs *filesystem) RemoveXattrAt(ctx context.Context, rp *vfs.ResolvingPath, name string) error { _, _, err := fs.walk(ctx, rp, false) if err != nil { return err diff --git a/pkg/sentry/fsimpl/ext/inode.go b/pkg/sentry/fsimpl/ext/inode.go index 30636cf66..9009ba3c7 100644 --- a/pkg/sentry/fsimpl/ext/inode.go +++ b/pkg/sentry/fsimpl/ext/inode.go @@ -37,6 +37,8 @@ import ( // |-- regular-- // |-- extent file // |-- block map file +// +// +stateify savable type inode struct { // refs is a reference count. refs is accessed using atomic memory operations. refs int64 diff --git a/pkg/sentry/fsimpl/ext/regular_file.go b/pkg/sentry/fsimpl/ext/regular_file.go index e73e740d6..4a5539b37 100644 --- a/pkg/sentry/fsimpl/ext/regular_file.go +++ b/pkg/sentry/fsimpl/ext/regular_file.go @@ -31,6 +31,8 @@ import ( // regularFile represents a regular file's inode. This too follows the // inheritance pattern prevelant in the vfs layer described in // pkg/sentry/vfs/README.md. +// +// +stateify savable type regularFile struct { inode inode @@ -67,6 +69,8 @@ func (in *inode) isRegular() bool { // directoryFD represents a directory file description. It implements // vfs.FileDescriptionImpl. +// +// +stateify savable type regularFileFD struct { fileDescription vfs.LockFD @@ -75,7 +79,7 @@ type regularFileFD struct { off int64 // offMu serializes operations that may mutate off. - offMu sync.Mutex + offMu sync.Mutex `state:"nosave"` } // Release implements vfs.FileDescriptionImpl.Release. diff --git a/pkg/sentry/fsimpl/ext/symlink.go b/pkg/sentry/fsimpl/ext/symlink.go index 2fd0d1fa8..5e2bcc837 100644 --- a/pkg/sentry/fsimpl/ext/symlink.go +++ b/pkg/sentry/fsimpl/ext/symlink.go @@ -23,6 +23,8 @@ import ( ) // symlink represents a symlink inode. +// +// +stateify savable type symlink struct { inode inode target string // immutable @@ -61,9 +63,11 @@ func (in *inode) isSymlink() bool { return ok } -// symlinkFD represents a symlink file description and implements implements +// symlinkFD represents a symlink file description and implements // vfs.FileDescriptionImpl. which may only be used if open options contains // O_PATH. For this reason most of the functions return EBADF. +// +// +stateify savable type symlinkFD struct { fileDescription vfs.NoLockFD diff --git a/pkg/sentry/fsimpl/ext/utils.go b/pkg/sentry/fsimpl/ext/utils.go index d8b728f8c..58ef7b9b8 100644 --- a/pkg/sentry/fsimpl/ext/utils.go +++ b/pkg/sentry/fsimpl/ext/utils.go @@ -17,21 +17,21 @@ package ext import ( "io" - "gvisor.dev/gvisor/pkg/binary" + "gvisor.dev/gvisor/pkg/marshal" "gvisor.dev/gvisor/pkg/sentry/fsimpl/ext/disklayout" "gvisor.dev/gvisor/pkg/syserror" ) // readFromDisk performs a binary read from disk into the given struct from // the absolute offset provided. -func readFromDisk(dev io.ReaderAt, abOff int64, v interface{}) error { - n := binary.Size(v) +func readFromDisk(dev io.ReaderAt, abOff int64, v marshal.Marshallable) error { + n := v.SizeBytes() buf := make([]byte, n) if read, _ := dev.ReadAt(buf, abOff); read < int(n) { return syserror.EIO } - binary.Unmarshal(buf, binary.LittleEndian, v) + v.UnmarshalBytes(buf) return nil } diff --git a/pkg/sentry/fsimpl/fuse/BUILD b/pkg/sentry/fsimpl/fuse/BUILD index 53a4f3012..045d7ab08 100644 --- a/pkg/sentry/fsimpl/fuse/BUILD +++ b/pkg/sentry/fsimpl/fuse/BUILD @@ -30,19 +30,26 @@ go_library( name = "fuse", srcs = [ "connection.go", + "connection_control.go", "dev.go", + "directory.go", + "file.go", "fusefs.go", - "init.go", "inode_refs.go", + "read_write.go", "register.go", + "regular_file.go", "request_list.go", + "request_response.go", ], visibility = ["//pkg/sentry:internal"], deps = [ "//pkg/abi/linux", "//pkg/context", "//pkg/log", + "//pkg/marshal", "//pkg/refs", + "//pkg/safemem", "//pkg/sentry/fsimpl/devtmpfs", "//pkg/sentry/fsimpl/kernfs", "//pkg/sentry/kernel", @@ -52,7 +59,6 @@ go_library( "//pkg/syserror", "//pkg/usermem", "//pkg/waiter", - "//tools/go_marshal/marshal", "@org_golang_x_sys//unix:go_default_library", ], ) @@ -60,10 +66,15 @@ go_library( go_test( name = "fuse_test", size = "small", - srcs = ["dev_test.go"], + srcs = [ + "connection_test.go", + "dev_test.go", + "utils_test.go", + ], library = ":fuse", deps = [ "//pkg/abi/linux", + "//pkg/marshal", "//pkg/sentry/fsimpl/testutil", "//pkg/sentry/kernel", "//pkg/sentry/kernel/auth", @@ -71,6 +82,5 @@ go_test( "//pkg/syserror", "//pkg/usermem", "//pkg/waiter", - "//tools/go_marshal/marshal", ], ) diff --git a/pkg/sentry/fsimpl/fuse/connection.go b/pkg/sentry/fsimpl/fuse/connection.go index 6df2728ab..8ccda1264 100644 --- a/pkg/sentry/fsimpl/fuse/connection.go +++ b/pkg/sentry/fsimpl/fuse/connection.go @@ -15,31 +15,17 @@ package fuse import ( - "errors" - "fmt" "sync" - "sync/atomic" - "syscall" "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/log" "gvisor.dev/gvisor/pkg/sentry/kernel" - "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/waiter" - "gvisor.dev/gvisor/tools/go_marshal/marshal" ) -// maxActiveRequestsDefault is the default setting controlling the upper bound -// on the number of active requests at any given time. -const maxActiveRequestsDefault = 10000 - -// Ordinary requests have even IDs, while interrupts IDs are odd. -// Used to increment the unique ID for each FUSE request. -var reqIDStep uint64 = 2 - const ( // fuseDefaultMaxBackground is the default value for MaxBackground. fuseDefaultMaxBackground = 12 @@ -52,43 +38,39 @@ const ( fuseDefaultMaxPagesPerReq = 32 ) -// Request represents a FUSE operation request that hasn't been sent to the -// server yet. +// connection is the struct by which the sentry communicates with the FUSE server daemon. // -// +stateify savable -type Request struct { - requestEntry - - id linux.FUSEOpID - hdr *linux.FUSEHeaderIn - data []byte -} - -// Response represents an actual response from the server, including the -// response payload. +// Lock order: +// - conn.fd.mu +// - conn.mu +// - conn.asyncMu // // +stateify savable -type Response struct { - opcode linux.FUSEOpcode - hdr linux.FUSEHeaderOut - data []byte -} - -// connection is the struct by which the sentry communicates with the FUSE server daemon. type connection struct { fd *DeviceFD + // mu protects access to struct memebers. + mu sync.Mutex `state:"nosave"` + + // attributeVersion is the version of connection's attributes. + attributeVersion uint64 + + // We target FUSE 7.23. // The following FUSE_INIT flags are currently unsupported by this implementation: - // - FUSE_ATOMIC_O_TRUNC: requires open(..., O_TRUNC) // - FUSE_EXPORT_SUPPORT - // - FUSE_HANDLE_KILLPRIV // - FUSE_POSIX_LOCKS: requires POSIX locks // - FUSE_FLOCK_LOCKS: requires POSIX locks // - FUSE_AUTO_INVAL_DATA: requires page caching eviction - // - FUSE_EXPLICIT_INVAL_DATA: requires page caching eviction // - FUSE_DO_READDIRPLUS/FUSE_READDIRPLUS_AUTO: requires FUSE_READDIRPLUS implementation // - FUSE_ASYNC_DIO - // - FUSE_POSIX_ACL: affects defaultPermissions, posixACL, xattr handler + // - FUSE_PARALLEL_DIROPS (7.25) + // - FUSE_HANDLE_KILLPRIV (7.26) + // - FUSE_POSIX_ACL: affects defaultPermissions, posixACL, xattr handler (7.26) + // - FUSE_ABORT_ERROR (7.27) + // - FUSE_CACHE_SYMLINKS (7.28) + // - FUSE_NO_OPENDIR_SUPPORT (7.29) + // - FUSE_EXPLICIT_INVAL_DATA: requires page caching eviction (7.30) + // - FUSE_MAP_ALIGNMENT (7.31) // initialized after receiving FUSE_INIT reply. // Until it's set, suspend sending FUSE requests. @@ -96,11 +78,7 @@ type connection struct { initialized int32 // initializedChan is used to block requests before initialization. - initializedChan chan struct{} - - // blocked when there are too many outstading backgrounds requests (NumBackground == MaxBackground). - // TODO(gvisor.dev/issue/3185): update the numBackground accordingly; use a channel to block. - blocked bool + initializedChan chan struct{} `state:".(bool)"` // connected (connection established) when a new FUSE file system is created. // Set to false when: @@ -109,48 +87,55 @@ type connection struct { // device release. connected bool - // aborted via sysfs. - // TODO(gvisor.dev/issue/3185): abort all queued requests. - aborted bool - // connInitError if FUSE_INIT encountered error (major version mismatch). // Only set in INIT. connInitError bool // connInitSuccess if FUSE_INIT is successful. // Only set in INIT. - // Used for destory. + // Used for destory (not yet implemented). connInitSuccess bool - // TODO(gvisor.dev/issue/3185): All the queue logic are working in progress. - - // NumberBackground is the number of requests in the background. - numBackground uint16 + // aborted via sysfs, and will send ECONNABORTED to read after disconnection (instead of ENODEV). + // Set only if abortErr is true and via fuse control fs (not yet implemented). + // TODO(gvisor.dev/issue/3525): set this to true when user aborts. + aborted bool - // congestionThreshold for NumBackground. - // Negotiated in FUSE_INIT. - congestionThreshold uint16 + // numWating is the number of requests waiting to be + // sent to FUSE device or being processed by FUSE daemon. + numWaiting uint32 - // maxBackground is the maximum number of NumBackground. - // Block connection when it is reached. - // Negotiated in FUSE_INIT. - maxBackground uint16 + // Terminology note: + // + // - `asyncNumMax` is the `MaxBackground` in the FUSE_INIT_IN struct. + // + // - `asyncCongestionThreshold` is the `CongestionThreshold` in the FUSE_INIT_IN struct. + // + // We call the "background" requests in unix term as async requests. + // The "async requests" in unix term is our async requests that expect a reply, + // i.e. `!request.noReply` - // numActiveBackground is the number of requests in background and has being marked as active. - numActiveBackground uint16 + // asyncMu protects the async request fields. + asyncMu sync.Mutex `state:"nosave"` - // numWating is the number of requests waiting for completion. - numWaiting uint32 + // asyncNum is the number of async requests. + // Protected by asyncMu. + asyncNum uint16 - // TODO(gvisor.dev/issue/3185): BgQueue - // some queue for background queued requests. + // asyncCongestionThreshold the number of async requests. + // Negotiated in FUSE_INIT as "CongestionThreshold". + // TODO(gvisor.dev/issue/3529): add congestion control. + // Protected by asyncMu. + asyncCongestionThreshold uint16 - // bgLock protects: - // MaxBackground, CongestionThreshold, NumBackground, - // NumActiveBackground, BgQueue, Blocked. - bgLock sync.Mutex + // asyncNumMax is the maximum number of asyncNum. + // Connection blocks the async requests when it is reached. + // Negotiated in FUSE_INIT as "MaxBackground". + // Protected by asyncMu. + asyncNumMax uint16 // maxRead is the maximum size of a read buffer in in bytes. + // Initialized from a fuse fs parameter. maxRead uint32 // maxWrite is the maximum size of a write buffer in bytes. @@ -165,23 +150,20 @@ type connection struct { // Negotiated and only set in INIT. minor uint32 - // asyncRead if read pages asynchronously. + // atomicOTrunc is true when FUSE does not send a separate SETATTR request + // before open with O_TRUNC flag. // Negotiated and only set in INIT. - asyncRead bool + atomicOTrunc bool - // abortErr is true if kernel need to return an unique read error after abort. + // asyncRead if read pages asynchronously. // Negotiated and only set in INIT. - abortErr bool + asyncRead bool // writebackCache is true for write-back cache policy, // false for write-through policy. // Negotiated and only set in INIT. writebackCache bool - // cacheSymlinks if filesystem needs to cache READLINK responses in page cache. - // Negotiated and only set in INIT. - cacheSymlinks bool - // bigWrites if doing multi-page cached writes. // Negotiated and only set in INIT. bigWrites bool @@ -189,116 +171,86 @@ type connection struct { // dontMask if filestestem does not apply umask to creation modes. // Negotiated in INIT. dontMask bool + + // noOpen if FUSE server doesn't support open operation. + // This flag only influence performance, not correctness of the program. + noOpen bool +} + +func (conn *connection) saveInitializedChan() bool { + select { + case <-conn.initializedChan: + return true // Closed. + default: + return false // Not closed. + } +} + +func (conn *connection) loadInitializedChan(closed bool) { + conn.initializedChan = make(chan struct{}, 1) + if closed { + close(conn.initializedChan) + } } // newFUSEConnection creates a FUSE connection to fd. -func newFUSEConnection(_ context.Context, fd *vfs.FileDescription, maxInFlightRequests uint64) (*connection, error) { +func newFUSEConnection(_ context.Context, fd *vfs.FileDescription, opts *filesystemOptions) (*connection, error) { // Mark the device as ready so it can be used. /dev/fuse can only be used if the FD was used to // mount a FUSE filesystem. fuseFD := fd.Impl().(*DeviceFD) - fuseFD.mounted = true // Create the writeBuf for the header to be stored in. hdrLen := uint32((*linux.FUSEHeaderOut)(nil).SizeBytes()) fuseFD.writeBuf = make([]byte, hdrLen) fuseFD.completions = make(map[linux.FUSEOpID]*futureResponse) - fuseFD.fullQueueCh = make(chan struct{}, maxInFlightRequests) + fuseFD.fullQueueCh = make(chan struct{}, opts.maxActiveRequests) fuseFD.writeCursor = 0 return &connection{ - fd: fuseFD, - maxBackground: fuseDefaultMaxBackground, - congestionThreshold: fuseDefaultCongestionThreshold, - maxPages: fuseDefaultMaxPagesPerReq, - initializedChan: make(chan struct{}), - connected: true, - }, nil -} - -// SetInitialized atomically sets the connection as initialized. -func (conn *connection) SetInitialized() { - // Unblock the requests sent before INIT. - close(conn.initializedChan) - - // Close the channel first to avoid the non-atomic situation - // where conn.initialized is true but there are - // tasks being blocked on the channel. - // And it prevents the newer tasks from gaining - // unnecessary higher chance to be issued before the blocked one. - - atomic.StoreInt32(&(conn.initialized), int32(1)) -} - -// IsInitialized atomically check if the connection is initialized. -// pairs with SetInitialized(). -func (conn *connection) Initialized() bool { - return atomic.LoadInt32(&(conn.initialized)) != 0 -} - -// NewRequest creates a new request that can be sent to the FUSE server. -func (conn *connection) NewRequest(creds *auth.Credentials, pid uint32, ino uint64, opcode linux.FUSEOpcode, payload marshal.Marshallable) (*Request, error) { - conn.fd.mu.Lock() - defer conn.fd.mu.Unlock() - conn.fd.nextOpID += linux.FUSEOpID(reqIDStep) - - hdrLen := (*linux.FUSEHeaderIn)(nil).SizeBytes() - hdr := linux.FUSEHeaderIn{ - Len: uint32(hdrLen + payload.SizeBytes()), - Opcode: opcode, - Unique: conn.fd.nextOpID, - NodeID: ino, - UID: uint32(creds.EffectiveKUID), - GID: uint32(creds.EffectiveKGID), - PID: pid, - } - - buf := make([]byte, hdr.Len) - hdr.MarshalUnsafe(buf[:hdrLen]) - payload.MarshalUnsafe(buf[hdrLen:]) - - return &Request{ - id: hdr.Unique, - hdr: &hdr, - data: buf, + fd: fuseFD, + asyncNumMax: fuseDefaultMaxBackground, + asyncCongestionThreshold: fuseDefaultCongestionThreshold, + maxRead: opts.maxRead, + maxPages: fuseDefaultMaxPagesPerReq, + initializedChan: make(chan struct{}), + connected: true, }, nil } -// Call makes a request to the server and blocks the invoking task until a -// server responds with a response. Task should never be nil. -// Requests will not be sent before the connection is initialized. -// For async tasks, use CallAsync(). -func (conn *connection) Call(t *kernel.Task, r *Request) (*Response, error) { - // Block requests sent before connection is initalized. - if !conn.Initialized() { - if err := t.Block(conn.initializedChan); err != nil { - return nil, err - } - } - - return conn.call(t, r) +// CallAsync makes an async (aka background) request. +// It's a simple wrapper around Call(). +func (conn *connection) CallAsync(t *kernel.Task, r *Request) error { + r.async = true + _, err := conn.Call(t, r) + return err } -// CallAsync makes an async (aka background) request. -// Those requests either do not expect a response (e.g. release) or -// the response should be handled by others (e.g. init). -// Return immediately unless the connection is blocked (before initialization). -// Async call example: init, release, forget, aio, interrupt. +// Call makes a request to the server. +// Block before the connection is initialized. // When the Request is FUSE_INIT, it will not be blocked before initialization. -func (conn *connection) CallAsync(t *kernel.Task, r *Request) error { +// Task should never be nil. +// +// For a sync request, it blocks the invoking task until +// a server responds with a response. +// +// For an async request (that do not expect a response immediately), +// it returns directly unless being blocked either before initialization +// or when there are too many async requests ongoing. +// +// Example for async request: +// init, readahead, write, async read/write, fuse_notify_reply, +// non-sync release, interrupt, forget. +// +// The forget request does not have a reply, +// as documented in include/uapi/linux/fuse.h:FUSE_FORGET. +func (conn *connection) Call(t *kernel.Task, r *Request) (*Response, error) { // Block requests sent before connection is initalized. if !conn.Initialized() && r.hdr.Opcode != linux.FUSE_INIT { if err := t.Block(conn.initializedChan); err != nil { - return err + return nil, err } } - // This should be the only place that invokes call() with a nil task. - _, err := conn.call(nil, r) - return err -} - -// call makes a call without blocking checks. -func (conn *connection) call(t *kernel.Task, r *Request) (*Response, error) { if !conn.connected { return nil, syserror.ENOTCONN } @@ -315,31 +267,6 @@ func (conn *connection) call(t *kernel.Task, r *Request) (*Response, error) { return fut.resolve(t) } -// Error returns the error of the FUSE call. -func (r *Response) Error() error { - errno := r.hdr.Error - if errno >= 0 { - return nil - } - - sysErrNo := syscall.Errno(-errno) - return error(sysErrNo) -} - -// UnmarshalPayload unmarshals the response data into m. -func (r *Response) UnmarshalPayload(m marshal.Marshallable) error { - hdrLen := r.hdr.SizeBytes() - haveDataLen := r.hdr.Len - uint32(hdrLen) - wantDataLen := uint32(m.SizeBytes()) - - if haveDataLen < wantDataLen { - return fmt.Errorf("payload too small. Minimum data lenth required: %d, but got data length %d", wantDataLen, haveDataLen) - } - - m.UnmarshalUnsafe(r.data[hdrLen:]) - return nil -} - // callFuture makes a request to the server and returns a future response. // Call resolve() when the response needs to be fulfilled. func (conn *connection) callFuture(t *kernel.Task, r *Request) (*futureResponse, error) { @@ -358,11 +285,6 @@ func (conn *connection) callFuture(t *kernel.Task, r *Request) (*futureResponse, // if there are always too many ongoing requests all the time. The // supported maxActiveRequests setting should be really high to avoid this. for conn.fd.numActiveRequests == conn.fd.fs.opts.maxActiveRequests { - if t == nil { - // Since there is no task that is waiting. We must error out. - return nil, errors.New("FUSE request queue full") - } - log.Infof("Blocking request %v from being queued. Too many active requests: %v", r.id, conn.fd.numActiveRequests) conn.fd.mu.Unlock() @@ -378,9 +300,19 @@ func (conn *connection) callFuture(t *kernel.Task, r *Request) (*futureResponse, // callFutureLocked makes a request to the server and returns a future response. func (conn *connection) callFutureLocked(t *kernel.Task, r *Request) (*futureResponse, error) { + // Check connected again holding conn.mu. + conn.mu.Lock() + if !conn.connected { + conn.mu.Unlock() + // we checked connected before, + // this must be due to aborted connection. + return nil, syserror.ECONNABORTED + } + conn.mu.Unlock() + conn.fd.queue.PushBack(r) - conn.fd.numActiveRequests += 1 - fut := newFutureResponse(r.hdr.Opcode) + conn.fd.numActiveRequests++ + fut := newFutureResponse(r) conn.fd.completions[r.id] = fut // Signal the readers that there is something to read. @@ -388,50 +320,3 @@ func (conn *connection) callFutureLocked(t *kernel.Task, r *Request) (*futureRes return fut, nil } - -// futureResponse represents an in-flight request, that may or may not have -// completed yet. Convert it to a resolved Response by calling Resolve, but note -// that this may block. -// -// +stateify savable -type futureResponse struct { - opcode linux.FUSEOpcode - ch chan struct{} - hdr *linux.FUSEHeaderOut - data []byte -} - -// newFutureResponse creates a future response to a FUSE request. -func newFutureResponse(opcode linux.FUSEOpcode) *futureResponse { - return &futureResponse{ - opcode: opcode, - ch: make(chan struct{}), - } -} - -// resolve blocks the task until the server responds to its corresponding request, -// then returns a resolved response. -func (f *futureResponse) resolve(t *kernel.Task) (*Response, error) { - // If there is no Task associated with this request - then we don't try to resolve - // the response. Instead, the task writing the response (proxy to the server) will - // process the response on our behalf. - if t == nil { - log.Infof("fuse.Response.resolve: Not waiting on a response from server.") - return nil, nil - } - - if err := t.Block(f.ch); err != nil { - return nil, err - } - - return f.getResponse(), nil -} - -// getResponse creates a Response from the data the futureResponse has. -func (f *futureResponse) getResponse() *Response { - return &Response{ - opcode: f.opcode, - hdr: *f.hdr, - data: f.data, - } -} diff --git a/pkg/sentry/fsimpl/fuse/init.go b/pkg/sentry/fsimpl/fuse/connection_control.go index 779c2bd3f..bfde78559 100644 --- a/pkg/sentry/fsimpl/fuse/init.go +++ b/pkg/sentry/fsimpl/fuse/connection_control.go @@ -15,7 +15,11 @@ package fuse import ( + "sync/atomic" + "syscall" + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" ) @@ -29,9 +33,10 @@ const ( // Follow the same behavior as unix fuse implementation. fuseMaxTimeGranNs = 1000000000 - // Minimum value for MaxWrite. + // Minimum value for MaxWrite and MaxRead. // Follow the same behavior as unix fuse implementation. fuseMinMaxWrite = 4096 + fuseMinMaxRead = 4096 // Temporary default value for max readahead, 128kb. fuseDefaultMaxReadahead = 131072 @@ -49,6 +54,26 @@ var ( MaxUserCongestionThreshold uint16 = fuseDefaultCongestionThreshold ) +// SetInitialized atomically sets the connection as initialized. +func (conn *connection) SetInitialized() { + // Unblock the requests sent before INIT. + close(conn.initializedChan) + + // Close the channel first to avoid the non-atomic situation + // where conn.initialized is true but there are + // tasks being blocked on the channel. + // And it prevents the newer tasks from gaining + // unnecessary higher chance to be issued before the blocked one. + + atomic.StoreInt32(&(conn.initialized), int32(1)) +} + +// IsInitialized atomically check if the connection is initialized. +// pairs with SetInitialized(). +func (conn *connection) Initialized() bool { + return atomic.LoadInt32(&(conn.initialized)) != 0 +} + // InitSend sends a FUSE_INIT request. func (conn *connection) InitSend(creds *auth.Credentials, pid uint32) error { in := linux.FUSEInitIn{ @@ -70,29 +95,31 @@ func (conn *connection) InitSend(creds *auth.Credentials, pid uint32) error { } // InitRecv receives a FUSE_INIT reply and process it. +// +// Preconditions: conn.asyncMu must not be held if minor verion is newer than 13. func (conn *connection) InitRecv(res *Response, hasSysAdminCap bool) error { if err := res.Error(); err != nil { return err } - var out linux.FUSEInitOut - if err := res.UnmarshalPayload(&out); err != nil { + initRes := fuseInitRes{initLen: res.DataLen()} + if err := res.UnmarshalPayload(&initRes); err != nil { return err } - return conn.initProcessReply(&out, hasSysAdminCap) + return conn.initProcessReply(&initRes.initOut, hasSysAdminCap) } // Process the FUSE_INIT reply from the FUSE server. +// It tries to acquire the conn.asyncMu lock if minor version is newer than 13. func (conn *connection) initProcessReply(out *linux.FUSEInitOut, hasSysAdminCap bool) error { + // No matter error or not, always set initialzied. + // to unblock the blocked requests. + defer conn.SetInitialized() + // No support for old major fuse versions. if out.Major != linux.FUSE_KERNEL_VERSION { conn.connInitError = true - - // Set the connection as initialized and unblock the blocked requests - // (i.e. return error for them). - conn.SetInitialized() - return nil } @@ -100,29 +127,14 @@ func (conn *connection) initProcessReply(out *linux.FUSEInitOut, hasSysAdminCap conn.connInitSuccess = true conn.minor = out.Minor - // No support for limits before minor version 13. - if out.Minor >= 13 { - conn.bgLock.Lock() - - if out.MaxBackground > 0 { - conn.maxBackground = out.MaxBackground - - if !hasSysAdminCap && - conn.maxBackground > MaxUserBackgroundRequest { - conn.maxBackground = MaxUserBackgroundRequest - } - } - - if out.CongestionThreshold > 0 { - conn.congestionThreshold = out.CongestionThreshold - - if !hasSysAdminCap && - conn.congestionThreshold > MaxUserCongestionThreshold { - conn.congestionThreshold = MaxUserCongestionThreshold - } - } - - conn.bgLock.Unlock() + // No support for negotiating MaxWrite before minor version 5. + if out.Minor >= 5 { + conn.maxWrite = out.MaxWrite + } else { + conn.maxWrite = fuseMinMaxWrite + } + if conn.maxWrite < fuseMinMaxWrite { + conn.maxWrite = fuseMinMaxWrite } // No support for the following flags before minor version 6. @@ -131,8 +143,6 @@ func (conn *connection) initProcessReply(out *linux.FUSEInitOut, hasSysAdminCap conn.bigWrites = out.Flags&linux.FUSE_BIG_WRITES != 0 conn.dontMask = out.Flags&linux.FUSE_DONT_MASK != 0 conn.writebackCache = out.Flags&linux.FUSE_WRITEBACK_CACHE != 0 - conn.cacheSymlinks = out.Flags&linux.FUSE_CACHE_SYMLINKS != 0 - conn.abortErr = out.Flags&linux.FUSE_ABORT_ERROR != 0 // TODO(gvisor.dev/issue/3195): figure out how to use TimeGran (0 < TimeGran <= fuseMaxTimeGranNs). @@ -148,19 +158,90 @@ func (conn *connection) initProcessReply(out *linux.FUSEInitOut, hasSysAdminCap } } - // No support for negotiating MaxWrite before minor version 5. - if out.Minor >= 5 { - conn.maxWrite = out.MaxWrite - } else { - conn.maxWrite = fuseMinMaxWrite + // No support for limits before minor version 13. + if out.Minor >= 13 { + conn.asyncMu.Lock() + + if out.MaxBackground > 0 { + conn.asyncNumMax = out.MaxBackground + + if !hasSysAdminCap && + conn.asyncNumMax > MaxUserBackgroundRequest { + conn.asyncNumMax = MaxUserBackgroundRequest + } + } + + if out.CongestionThreshold > 0 { + conn.asyncCongestionThreshold = out.CongestionThreshold + + if !hasSysAdminCap && + conn.asyncCongestionThreshold > MaxUserCongestionThreshold { + conn.asyncCongestionThreshold = MaxUserCongestionThreshold + } + } + + conn.asyncMu.Unlock() } - if conn.maxWrite < fuseMinMaxWrite { - conn.maxWrite = fuseMinMaxWrite + + return nil +} + +// Abort this FUSE connection. +// It tries to acquire conn.fd.mu, conn.lock, conn.bgLock in order. +// All possible requests waiting or blocking will be aborted. +// +// Preconditions: conn.fd.mu is locked. +func (conn *connection) Abort(ctx context.Context) { + conn.mu.Lock() + conn.asyncMu.Lock() + + if !conn.connected { + conn.asyncMu.Unlock() + conn.mu.Unlock() + conn.fd.mu.Unlock() + return } - // Set connection as initialized and unblock the requests - // issued before init. - conn.SetInitialized() + conn.connected = false - return nil + // Empty the `fd.queue` that holds the requests + // not yet read by the FUSE daemon yet. + // These are a subset of the requests in `fuse.completion` map. + for !conn.fd.queue.Empty() { + req := conn.fd.queue.Front() + conn.fd.queue.Remove(req) + } + + var terminate []linux.FUSEOpID + + // 2. Collect the requests have not been sent to FUSE daemon, + // or have not received a reply. + for unique := range conn.fd.completions { + terminate = append(terminate, unique) + } + + // Release locks to avoid deadlock. + conn.asyncMu.Unlock() + conn.mu.Unlock() + + // 1. The requets blocked before initialization. + // Will reach call() `connected` check and return. + if !conn.Initialized() { + conn.SetInitialized() + } + + // 2. Terminate the requests collected above. + // Set ECONNABORTED error. + // sendError() will remove them from `fd.completion` map. + // Will enter the path of a normally received error. + for _, toTerminate := range terminate { + conn.fd.sendError(ctx, -int32(syscall.ECONNABORTED), toTerminate) + } + + // 3. The requests not yet written to FUSE device. + // Early terminate. + // Will reach callFutureLocked() `connected` check and return. + close(conn.fd.fullQueueCh) + + // TODO(gvisor.dev/issue/3528): Forget all pending forget reqs. } diff --git a/pkg/sentry/fsimpl/fuse/connection_test.go b/pkg/sentry/fsimpl/fuse/connection_test.go new file mode 100644 index 000000000..91d16c1cf --- /dev/null +++ b/pkg/sentry/fsimpl/fuse/connection_test.go @@ -0,0 +1,117 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package fuse + +import ( + "math/rand" + "syscall" + "testing" + + "gvisor.dev/gvisor/pkg/sentry/kernel" + "gvisor.dev/gvisor/pkg/sentry/kernel/auth" + "gvisor.dev/gvisor/pkg/syserror" +) + +// TestConnectionInitBlock tests if initialization +// correctly blocks and unblocks the connection. +// Since it's unfeasible to test kernelTask.Block() in unit test, +// the code in Call() are not tested here. +func TestConnectionInitBlock(t *testing.T) { + s := setup(t) + defer s.Destroy() + + k := kernel.KernelFromContext(s.Ctx) + + conn, _, err := newTestConnection(s, k, maxActiveRequestsDefault) + if err != nil { + t.Fatalf("newTestConnection: %v", err) + } + + select { + case <-conn.initializedChan: + t.Fatalf("initializedChan should be blocking before SetInitialized") + default: + } + + conn.SetInitialized() + + select { + case <-conn.initializedChan: + default: + t.Fatalf("initializedChan should not be blocking after SetInitialized") + } +} + +func TestConnectionAbort(t *testing.T) { + s := setup(t) + defer s.Destroy() + + k := kernel.KernelFromContext(s.Ctx) + creds := auth.CredentialsFromContext(s.Ctx) + task := kernel.TaskFromContext(s.Ctx) + + const numRequests uint64 = 256 + + conn, _, err := newTestConnection(s, k, numRequests) + if err != nil { + t.Fatalf("newTestConnection: %v", err) + } + + testObj := &testPayload{ + data: rand.Uint32(), + } + + var futNormal []*futureResponse + + for i := 0; i < int(numRequests); i++ { + req, err := conn.NewRequest(creds, uint32(i), uint64(i), 0, testObj) + if err != nil { + t.Fatalf("NewRequest creation failed: %v", err) + } + fut, err := conn.callFutureLocked(task, req) + if err != nil { + t.Fatalf("callFutureLocked failed: %v", err) + } + futNormal = append(futNormal, fut) + } + + conn.Abort(s.Ctx) + + // Abort should unblock the initialization channel. + // Note: no test requests are actually blocked on `conn.initializedChan`. + select { + case <-conn.initializedChan: + default: + t.Fatalf("initializedChan should not be blocking after SetInitialized") + } + + // Abort will return ECONNABORTED error to unblocked requests. + for _, fut := range futNormal { + if fut.getResponse().hdr.Error != -int32(syscall.ECONNABORTED) { + t.Fatalf("Incorrect error code received for aborted connection: %v", fut.getResponse().hdr.Error) + } + } + + // After abort, Call() should return directly with ENOTCONN. + req, err := conn.NewRequest(creds, 0, 0, 0, testObj) + if err != nil { + t.Fatalf("NewRequest creation failed: %v", err) + } + _, err = conn.Call(task, req) + if err != syserror.ENOTCONN { + t.Fatalf("Incorrect error code received for Call() after connection aborted") + } + +} diff --git a/pkg/sentry/fsimpl/fuse/dev.go b/pkg/sentry/fsimpl/fuse/dev.go index e522ff9a0..1b86a4b4c 100644 --- a/pkg/sentry/fsimpl/fuse/dev.go +++ b/pkg/sentry/fsimpl/fuse/dev.go @@ -19,7 +19,6 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" - "gvisor.dev/gvisor/pkg/log" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/sentry/vfs" @@ -32,6 +31,8 @@ import ( const fuseDevMinor = 229 // fuseDevice implements vfs.Device for /dev/fuse. +// +// +stateify savable type fuseDevice struct{} // Open implements vfs.Device.Open. @@ -50,15 +51,14 @@ func (fuseDevice) Open(ctx context.Context, mnt *vfs.Mount, vfsd *vfs.Dentry, op } // DeviceFD implements vfs.FileDescriptionImpl for /dev/fuse. +// +// +stateify savable type DeviceFD struct { vfsfd vfs.FileDescription vfs.FileDescriptionDefaultImpl vfs.DentryMetadataFileDescriptionImpl vfs.NoLockFD - // mounted specifies whether a FUSE filesystem was mounted using the DeviceFD. - mounted bool - // nextOpID is used to create new requests. nextOpID linux.FUSEOpID @@ -83,7 +83,7 @@ type DeviceFD struct { writeCursorFR *futureResponse // mu protects all the queues, maps, buffers and cursors and nextOpID. - mu sync.Mutex + mu sync.Mutex `state:"nosave"` // waitQueue is used to notify interested parties when the device becomes // readable or writable. @@ -92,21 +92,36 @@ type DeviceFD struct { // fullQueueCh is a channel used to synchronize the readers with the writers. // Writers (inbound requests to the filesystem) block if there are too many // unprocessed in-flight requests. - fullQueueCh chan struct{} + fullQueueCh chan struct{} `state:".(int)"` // fs is the FUSE filesystem that this FD is being used for. fs *filesystem } +func (fd *DeviceFD) saveFullQueueCh() int { + return cap(fd.fullQueueCh) +} + +func (fd *DeviceFD) loadFullQueueCh(capacity int) { + fd.fullQueueCh = make(chan struct{}, capacity) +} + // Release implements vfs.FileDescriptionImpl.Release. -func (fd *DeviceFD) Release(context.Context) { - fd.fs.conn.connected = false +func (fd *DeviceFD) Release(ctx context.Context) { + if fd.fs != nil { + fd.fs.conn.mu.Lock() + fd.fs.conn.connected = false + fd.fs.conn.mu.Unlock() + + fd.fs.VFSFilesystem().DecRef(ctx) + fd.fs = nil + } } // PRead implements vfs.FileDescriptionImpl.PRead. func (fd *DeviceFD) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) { // Operations on /dev/fuse don't make sense until a FUSE filesystem is mounted. - if !fd.mounted { + if fd.fs == nil { return 0, syserror.EPERM } @@ -116,10 +131,16 @@ func (fd *DeviceFD) PRead(ctx context.Context, dst usermem.IOSequence, offset in // Read implements vfs.FileDescriptionImpl.Read. func (fd *DeviceFD) Read(ctx context.Context, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) { // Operations on /dev/fuse don't make sense until a FUSE filesystem is mounted. - if !fd.mounted { + if fd.fs == nil { return 0, syserror.EPERM } + // Return ENODEV if the filesystem is umounted. + if fd.fs.umounted { + // TODO(gvisor.dev/issue/3525): return ECONNABORTED if aborted via fuse control fs. + return 0, syserror.ENODEV + } + // We require that any Read done on this filesystem have a sane minimum // read buffer. It must have the capacity for the fixed parts of any request // header (Linux uses the request header and the FUSEWriteIn header for this @@ -143,58 +164,82 @@ func (fd *DeviceFD) Read(ctx context.Context, dst usermem.IOSequence, opts vfs.R } // readLocked implements the reading of the fuse device while locked with DeviceFD.mu. +// +// Preconditions: dst is large enough for any reasonable request. func (fd *DeviceFD) readLocked(ctx context.Context, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) { - if fd.queue.Empty() { - return 0, syserror.ErrWouldBlock - } + var req *Request - var readCursor uint32 - var bytesRead int64 - for { - req := fd.queue.Front() - if dst.NumBytes() < int64(req.hdr.Len) { - // The request is too large. Cannot process it. All requests must be smaller than the - // negotiated size as specified by Connection.MaxWrite set as part of the FUSE_INIT - // handshake. - errno := -int32(syscall.EIO) - if req.hdr.Opcode == linux.FUSE_SETXATTR { - errno = -int32(syscall.E2BIG) - } + // Find the first valid request. + // For the normal case this loop only execute once. + for !fd.queue.Empty() { + req = fd.queue.Front() - // Return the error to the calling task. - if err := fd.sendError(ctx, errno, req); err != nil { - return 0, err - } + if int64(req.hdr.Len)+int64(len(req.payload)) <= dst.NumBytes() { + break + } - // We're done with this request. - fd.queue.Remove(req) + // The request is too large. Cannot process it. All requests must be smaller than the + // negotiated size as specified by Connection.MaxWrite set as part of the FUSE_INIT + // handshake. + errno := -int32(syscall.EIO) + if req.hdr.Opcode == linux.FUSE_SETXATTR { + errno = -int32(syscall.E2BIG) + } - // Restart the read as this request was invalid. - log.Warningf("fuse.DeviceFD.Read: request found was too large. Restarting read.") - return fd.readLocked(ctx, dst, opts) + // Return the error to the calling task. + if err := fd.sendError(ctx, errno, req.hdr.Unique); err != nil { + return 0, err } - n, err := dst.CopyOut(ctx, req.data[readCursor:]) + // We're done with this request. + fd.queue.Remove(req) + req = nil + } + + if req == nil { + return 0, syserror.ErrWouldBlock + } + + // We already checked the size: dst must be able to fit the whole request. + // Now we write the marshalled header, the payload, + // and the potential additional payload + // to the user memory IOSequence. + + n, err := dst.CopyOut(ctx, req.data) + if err != nil { + return 0, err + } + if n != len(req.data) { + return 0, syserror.EIO + } + + if req.hdr.Opcode == linux.FUSE_WRITE { + written, err := dst.DropFirst(n).CopyOut(ctx, req.payload) if err != nil { return 0, err } - readCursor += uint32(n) - bytesRead += int64(n) - - if readCursor >= req.hdr.Len { - // Fully done with this req, remove it from the queue. - fd.queue.Remove(req) - break + if written != len(req.payload) { + return 0, syserror.EIO } + n += int(written) } - return bytesRead, nil + // Fully done with this req, remove it from the queue. + fd.queue.Remove(req) + + // Remove noReply ones from map of requests expecting a reply. + if req.noReply { + fd.numActiveRequests -= 1 + delete(fd.completions, req.hdr.Unique) + } + + return int64(n), nil } // PWrite implements vfs.FileDescriptionImpl.PWrite. func (fd *DeviceFD) PWrite(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) { // Operations on /dev/fuse don't make sense until a FUSE filesystem is mounted. - if !fd.mounted { + if fd.fs == nil { return 0, syserror.EPERM } @@ -211,10 +256,15 @@ func (fd *DeviceFD) Write(ctx context.Context, src usermem.IOSequence, opts vfs. // writeLocked implements writing to the fuse device while locked with DeviceFD.mu. func (fd *DeviceFD) writeLocked(ctx context.Context, src usermem.IOSequence, opts vfs.WriteOptions) (int64, error) { // Operations on /dev/fuse don't make sense until a FUSE filesystem is mounted. - if !fd.mounted { + if fd.fs == nil { return 0, syserror.EPERM } + // Return ENODEV if the filesystem is umounted. + if fd.fs.umounted { + return 0, syserror.ENODEV + } + var cn, n int64 hdrLen := uint32((*linux.FUSEHeaderOut)(nil).SizeBytes()) @@ -276,7 +326,8 @@ func (fd *DeviceFD) writeLocked(ctx context.Context, src usermem.IOSequence, opt fut, ok := fd.completions[hdr.Unique] if !ok { - // Server sent us a response for a request we never sent? + // Server sent us a response for a request we never sent, + // or for which we already received a reply (e.g. aborted), an unlikely event. return 0, syserror.EINVAL } @@ -307,8 +358,23 @@ func (fd *DeviceFD) writeLocked(ctx context.Context, src usermem.IOSequence, opt // Readiness implements vfs.FileDescriptionImpl.Readiness. func (fd *DeviceFD) Readiness(mask waiter.EventMask) waiter.EventMask { + fd.mu.Lock() + defer fd.mu.Unlock() + return fd.readinessLocked(mask) +} + +// readinessLocked implements checking the readiness of the fuse device while +// locked with DeviceFD.mu. +func (fd *DeviceFD) readinessLocked(mask waiter.EventMask) waiter.EventMask { var ready waiter.EventMask - ready |= waiter.EventOut // FD is always writable + + if fd.fs.umounted { + ready |= waiter.EventErr + return ready & mask + } + + // FD is always writable. + ready |= waiter.EventOut if !fd.queue.Empty() { // Have reqs available, FD is readable. ready |= waiter.EventIn @@ -330,7 +396,7 @@ func (fd *DeviceFD) EventUnregister(e *waiter.Entry) { // Seek implements vfs.FileDescriptionImpl.Seek. func (fd *DeviceFD) Seek(ctx context.Context, offset int64, whence int32) (int64, error) { // Operations on /dev/fuse don't make sense until a FUSE filesystem is mounted. - if !fd.mounted { + if fd.fs == nil { return 0, syserror.EPERM } @@ -338,59 +404,59 @@ func (fd *DeviceFD) Seek(ctx context.Context, offset int64, whence int32) (int64 } // sendResponse sends a response to the waiting task (if any). +// +// Preconditions: fd.mu must be held. func (fd *DeviceFD) sendResponse(ctx context.Context, fut *futureResponse) error { - // See if the running task need to perform some action before returning. - // Since we just finished writing the future, we can be sure that - // getResponse generates a populated response. - if err := fd.noReceiverAction(ctx, fut.getResponse()); err != nil { - return err - } + // Signal the task waiting on a response if any. + defer close(fut.ch) // Signal that the queue is no longer full. select { case fd.fullQueueCh <- struct{}{}: default: } - fd.numActiveRequests -= 1 + fd.numActiveRequests-- + + if fut.async { + return fd.asyncCallBack(ctx, fut.getResponse()) + } - // Signal the task waiting on a response. - close(fut.ch) return nil } -// sendError sends an error response to the waiting task (if any). -func (fd *DeviceFD) sendError(ctx context.Context, errno int32, req *Request) error { +// sendError sends an error response to the waiting task (if any) by calling sendResponse(). +// +// Preconditions: fd.mu must be held. +func (fd *DeviceFD) sendError(ctx context.Context, errno int32, unique linux.FUSEOpID) error { // Return the error to the calling task. outHdrLen := uint32((*linux.FUSEHeaderOut)(nil).SizeBytes()) respHdr := linux.FUSEHeaderOut{ Len: outHdrLen, Error: errno, - Unique: req.hdr.Unique, + Unique: unique, } fut, ok := fd.completions[respHdr.Unique] if !ok { - // Server sent us a response for a request we never sent? + // A response for a request we never sent, + // or for which we already received a reply (e.g. aborted). return syserror.EINVAL } delete(fd.completions, respHdr.Unique) fut.hdr = &respHdr - if err := fd.sendResponse(ctx, fut); err != nil { - return err - } - - return nil + return fd.sendResponse(ctx, fut) } -// noReceiverAction has the calling kernel.Task do some action if its known that no -// receiver is going to be waiting on the future channel. This is to be used by: -// FUSE_INIT. -func (fd *DeviceFD) noReceiverAction(ctx context.Context, r *Response) error { - if r.opcode == linux.FUSE_INIT { +// asyncCallBack executes pre-defined callback function for async requests. +// Currently used by: FUSE_INIT. +func (fd *DeviceFD) asyncCallBack(ctx context.Context, r *Response) error { + switch r.opcode { + case linux.FUSE_INIT: creds := auth.CredentialsFromContext(ctx) rootUserNs := kernel.KernelFromContext(ctx).RootUserNamespace() return fd.fs.conn.InitRecv(r, creds.HasCapabilityIn(linux.CAP_SYS_ADMIN, rootUserNs)) + // TODO(gvisor.dev/issue/3247): support async read: correctly process the response. } return nil diff --git a/pkg/sentry/fsimpl/fuse/dev_test.go b/pkg/sentry/fsimpl/fuse/dev_test.go index 1ffe7ccd2..5986133e9 100644 --- a/pkg/sentry/fsimpl/fuse/dev_test.go +++ b/pkg/sentry/fsimpl/fuse/dev_test.go @@ -16,7 +16,6 @@ package fuse import ( "fmt" - "io" "math/rand" "testing" @@ -28,17 +27,12 @@ import ( "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/usermem" "gvisor.dev/gvisor/pkg/waiter" - "gvisor.dev/gvisor/tools/go_marshal/marshal" ) // echoTestOpcode is the Opcode used during testing. The server used in tests // will simply echo the payload back with the appropriate headers. const echoTestOpcode linux.FUSEOpcode = 1000 -type testPayload struct { - data uint32 -} - // TestFUSECommunication tests that the communication layer between the Sentry and the // FUSE server daemon works as expected. func TestFUSECommunication(t *testing.T) { @@ -327,102 +321,3 @@ func fuseServerRun(t *testing.T, s *testutil.System, k *kernel.Kernel, fd *vfs.F } } } - -func setup(t *testing.T) *testutil.System { - k, err := testutil.Boot() - if err != nil { - t.Fatalf("Error creating kernel: %v", err) - } - - ctx := k.SupervisorContext() - creds := auth.CredentialsFromContext(ctx) - - k.VFS().MustRegisterFilesystemType(Name, &FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{ - AllowUserList: true, - AllowUserMount: true, - }) - - mntns, err := k.VFS().NewMountNamespace(ctx, creds, "", "tmpfs", &vfs.GetFilesystemOptions{}) - if err != nil { - t.Fatalf("NewMountNamespace(): %v", err) - } - - return testutil.NewSystem(ctx, t, k.VFS(), mntns) -} - -// newTestConnection creates a fuse connection that the sentry can communicate with -// and the FD for the server to communicate with. -func newTestConnection(system *testutil.System, k *kernel.Kernel, maxActiveRequests uint64) (*connection, *vfs.FileDescription, error) { - vfsObj := &vfs.VirtualFilesystem{} - fuseDev := &DeviceFD{} - - if err := vfsObj.Init(system.Ctx); err != nil { - return nil, nil, err - } - - vd := vfsObj.NewAnonVirtualDentry("genCountFD") - defer vd.DecRef(system.Ctx) - if err := fuseDev.vfsfd.Init(fuseDev, linux.O_RDWR|linux.O_CREAT, vd.Mount(), vd.Dentry(), &vfs.FileDescriptionOptions{}); err != nil { - return nil, nil, err - } - - fsopts := filesystemOptions{ - maxActiveRequests: maxActiveRequests, - } - fs, err := NewFUSEFilesystem(system.Ctx, 0, &fsopts, &fuseDev.vfsfd) - if err != nil { - return nil, nil, err - } - - return fs.conn, &fuseDev.vfsfd, nil -} - -// SizeBytes implements marshal.Marshallable.SizeBytes. -func (t *testPayload) SizeBytes() int { - return 4 -} - -// MarshalBytes implements marshal.Marshallable.MarshalBytes. -func (t *testPayload) MarshalBytes(dst []byte) { - usermem.ByteOrder.PutUint32(dst[:4], t.data) -} - -// UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes. -func (t *testPayload) UnmarshalBytes(src []byte) { - *t = testPayload{data: usermem.ByteOrder.Uint32(src[:4])} -} - -// Packed implements marshal.Marshallable.Packed. -func (t *testPayload) Packed() bool { - return true -} - -// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe. -func (t *testPayload) MarshalUnsafe(dst []byte) { - t.MarshalBytes(dst) -} - -// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe. -func (t *testPayload) UnmarshalUnsafe(src []byte) { - t.UnmarshalBytes(src) -} - -// CopyOutN implements marshal.Marshallable.CopyOutN. -func (t *testPayload) CopyOutN(task marshal.Task, addr usermem.Addr, limit int) (int, error) { - panic("not implemented") -} - -// CopyOut implements marshal.Marshallable.CopyOut. -func (t *testPayload) CopyOut(task marshal.Task, addr usermem.Addr) (int, error) { - panic("not implemented") -} - -// CopyIn implements marshal.Marshallable.CopyIn. -func (t *testPayload) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) { - panic("not implemented") -} - -// WriteTo implements io.WriterTo.WriteTo. -func (t *testPayload) WriteTo(w io.Writer) (int64, error) { - panic("not implemented") -} diff --git a/pkg/sentry/fsimpl/fuse/directory.go b/pkg/sentry/fsimpl/fuse/directory.go new file mode 100644 index 000000000..8f220a04b --- /dev/null +++ b/pkg/sentry/fsimpl/fuse/directory.go @@ -0,0 +1,105 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package fuse + +import ( + "sync/atomic" + + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/sentry/kernel" + "gvisor.dev/gvisor/pkg/sentry/kernel/auth" + "gvisor.dev/gvisor/pkg/sentry/vfs" + "gvisor.dev/gvisor/pkg/syserror" + "gvisor.dev/gvisor/pkg/usermem" +) + +type directoryFD struct { + fileDescription +} + +// Allocate implements directoryFD.Allocate. +func (*directoryFD) Allocate(ctx context.Context, mode, offset, length uint64) error { + return syserror.EISDIR +} + +// PRead implements vfs.FileDescriptionImpl.PRead. +func (*directoryFD) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) { + return 0, syserror.EISDIR +} + +// Read implements vfs.FileDescriptionImpl.Read. +func (*directoryFD) Read(ctx context.Context, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) { + return 0, syserror.EISDIR +} + +// PWrite implements vfs.FileDescriptionImpl.PWrite. +func (*directoryFD) PWrite(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) { + return 0, syserror.EISDIR +} + +// Write implements vfs.FileDescriptionImpl.Write. +func (*directoryFD) Write(ctx context.Context, src usermem.IOSequence, opts vfs.WriteOptions) (int64, error) { + return 0, syserror.EISDIR +} + +// IterDirents implements vfs.FileDescriptionImpl.IterDirents. +func (dir *directoryFD) IterDirents(ctx context.Context, callback vfs.IterDirentsCallback) error { + fusefs := dir.inode().fs + task, creds := kernel.TaskFromContext(ctx), auth.CredentialsFromContext(ctx) + + in := linux.FUSEReadIn{ + Fh: dir.Fh, + Offset: uint64(atomic.LoadInt64(&dir.off)), + Size: linux.FUSE_PAGE_SIZE, + Flags: dir.statusFlags(), + } + + // TODO(gVisor.dev/issue/3404): Support FUSE_READDIRPLUS. + req, err := fusefs.conn.NewRequest(creds, uint32(task.ThreadID()), dir.inode().nodeID, linux.FUSE_READDIR, &in) + if err != nil { + return err + } + + res, err := fusefs.conn.Call(task, req) + if err != nil { + return err + } + if err := res.Error(); err != nil { + return err + } + + var out linux.FUSEDirents + if err := res.UnmarshalPayload(&out); err != nil { + return err + } + + for _, fuseDirent := range out.Dirents { + nextOff := int64(fuseDirent.Meta.Off) + dirent := vfs.Dirent{ + Name: fuseDirent.Name, + Type: uint8(fuseDirent.Meta.Type), + Ino: fuseDirent.Meta.Ino, + NextOff: nextOff, + } + + if err := callback.Handle(dirent); err != nil { + return err + } + atomic.StoreInt64(&dir.off, nextOff) + } + + return nil +} diff --git a/pkg/sentry/fsimpl/fuse/file.go b/pkg/sentry/fsimpl/fuse/file.go new file mode 100644 index 000000000..83f2816b7 --- /dev/null +++ b/pkg/sentry/fsimpl/fuse/file.go @@ -0,0 +1,133 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package fuse + +import ( + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs" + "gvisor.dev/gvisor/pkg/sentry/kernel" + "gvisor.dev/gvisor/pkg/sentry/kernel/auth" + "gvisor.dev/gvisor/pkg/sentry/vfs" + "gvisor.dev/gvisor/pkg/usermem" +) + +// fileDescription implements vfs.FileDescriptionImpl for fuse. +type fileDescription struct { + vfsfd vfs.FileDescription + vfs.FileDescriptionDefaultImpl + vfs.DentryMetadataFileDescriptionImpl + vfs.NoLockFD + + // the file handle used in userspace. + Fh uint64 + + // Nonseekable is indicate cannot perform seek on a file. + Nonseekable bool + + // DirectIO suggest fuse to use direct io operation. + DirectIO bool + + // OpenFlag is the flag returned by open. + OpenFlag uint32 + + // off is the file offset. + off int64 +} + +func (fd *fileDescription) dentry() *kernfs.Dentry { + return fd.vfsfd.Dentry().Impl().(*kernfs.Dentry) +} + +func (fd *fileDescription) inode() *inode { + return fd.dentry().Inode().(*inode) +} + +func (fd *fileDescription) filesystem() *vfs.Filesystem { + return fd.vfsfd.VirtualDentry().Mount().Filesystem() +} + +func (fd *fileDescription) statusFlags() uint32 { + return fd.vfsfd.StatusFlags() +} + +// Release implements vfs.FileDescriptionImpl.Release. +func (fd *fileDescription) Release(ctx context.Context) { + // no need to release if FUSE server doesn't implement Open. + conn := fd.inode().fs.conn + if conn.noOpen { + return + } + + in := linux.FUSEReleaseIn{ + Fh: fd.Fh, + Flags: fd.statusFlags(), + } + // TODO(gvisor.dev/issue/3245): add logic when we support file lock owner. + var opcode linux.FUSEOpcode + if fd.inode().Mode().IsDir() { + opcode = linux.FUSE_RELEASEDIR + } else { + opcode = linux.FUSE_RELEASE + } + kernelTask := kernel.TaskFromContext(ctx) + // ignoring errors and FUSE server reply is analogous to Linux's behavior. + req, err := conn.NewRequest(auth.CredentialsFromContext(ctx), uint32(kernelTask.ThreadID()), fd.inode().nodeID, opcode, &in) + if err != nil { + // No way to invoke Call() with an errored request. + return + } + // The reply will be ignored since no callback is defined in asyncCallBack(). + conn.CallAsync(kernelTask, req) +} + +// PRead implements vfs.FileDescriptionImpl.PRead. +func (fd *fileDescription) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) { + return 0, nil +} + +// Read implements vfs.FileDescriptionImpl.Read. +func (fd *fileDescription) Read(ctx context.Context, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) { + return 0, nil +} + +// PWrite implements vfs.FileDescriptionImpl.PWrite. +func (fd *fileDescription) PWrite(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) { + return 0, nil +} + +// Write implements vfs.FileDescriptionImpl.Write. +func (fd *fileDescription) Write(ctx context.Context, src usermem.IOSequence, opts vfs.WriteOptions) (int64, error) { + return 0, nil +} + +// Seek implements vfs.FileDescriptionImpl.Seek. +func (fd *fileDescription) Seek(ctx context.Context, offset int64, whence int32) (int64, error) { + return 0, nil +} + +// Stat implements vfs.FileDescriptionImpl.Stat. +func (fd *fileDescription) Stat(ctx context.Context, opts vfs.StatOptions) (linux.Statx, error) { + fs := fd.filesystem() + inode := fd.inode() + return inode.Stat(ctx, fs, opts) +} + +// SetStat implements vfs.FileDescriptionImpl.SetStat. +func (fd *fileDescription) SetStat(ctx context.Context, opts vfs.SetStatOptions) error { + fs := fd.filesystem() + creds := auth.CredentialsFromContext(ctx) + return fd.inode().setAttr(ctx, fs, creds, opts, true, fd.Fh) +} diff --git a/pkg/sentry/fsimpl/fuse/fusefs.go b/pkg/sentry/fsimpl/fuse/fusefs.go index 810819ae4..65786e42a 100644 --- a/pkg/sentry/fsimpl/fuse/fusefs.go +++ b/pkg/sentry/fsimpl/fuse/fusefs.go @@ -16,24 +16,36 @@ package fuse import ( + "math" "strconv" + "sync" + "sync/atomic" "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/log" + "gvisor.dev/gvisor/pkg/marshal" "gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/syserror" + "gvisor.dev/gvisor/pkg/waiter" ) // Name is the default filesystem name. const Name = "fuse" +// maxActiveRequestsDefault is the default setting controlling the upper bound +// on the number of active requests at any given time. +const maxActiveRequestsDefault = 10000 + // FilesystemType implements vfs.FilesystemType. +// +// +stateify savable type FilesystemType struct{} +// +stateify savable type filesystemOptions struct { // userID specifies the numeric uid of the mount owner. // This option should not be specified by the filesystem owner. @@ -56,9 +68,16 @@ type filesystemOptions struct { // exist at any time. Any further requests will block when trying to // Call the server. maxActiveRequests uint64 + + // maxRead is the max number of bytes to read, + // specified as "max_read" in fs parameters. + // If not specified by user, use math.MaxUint32 as default value. + maxRead uint32 } // filesystem implements vfs.FilesystemImpl. +// +// +stateify savable type filesystem struct { kernfs.Filesystem devMinor uint32 @@ -69,6 +88,9 @@ type filesystem struct { // opts is the options the fusefs is initialized with. opts *filesystemOptions + + // umounted is true if filesystem.Release() has been called. + umounted bool } // Name implements vfs.FilesystemType.Name. @@ -142,14 +164,29 @@ func (fsType FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt // Set the maxInFlightRequests option. fsopts.maxActiveRequests = maxActiveRequestsDefault + if maxReadStr, ok := mopts["max_read"]; ok { + delete(mopts, "max_read") + maxRead, err := strconv.ParseUint(maxReadStr, 10, 32) + if err != nil { + log.Warningf("%s.GetFilesystem: invalid max_read: max_read=%s", fsType.Name(), maxReadStr) + return nil, nil, syserror.EINVAL + } + if maxRead < fuseMinMaxRead { + maxRead = fuseMinMaxRead + } + fsopts.maxRead = uint32(maxRead) + } else { + fsopts.maxRead = math.MaxUint32 + } + // Check for unparsed options. if len(mopts) != 0 { - log.Warningf("%s.GetFilesystem: unknown options: %v", fsType.Name(), mopts) + log.Warningf("%s.GetFilesystem: unsupported or unknown options: %v", fsType.Name(), mopts) return nil, nil, syserror.EINVAL } // Create a new FUSE filesystem. - fs, err := NewFUSEFilesystem(ctx, devMinor, &fsopts, fuseFd) + fs, err := newFUSEFilesystem(ctx, devMinor, &fsopts, fuseFd) if err != nil { log.Warningf("%s.NewFUSEFilesystem: failed with error: %v", fsType.Name(), err) return nil, nil, err @@ -165,26 +202,28 @@ func (fsType FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt } // root is the fusefs root directory. - root := fs.newInode(creds, fsopts.rootMode) + root := fs.newRootInode(creds, fsopts.rootMode) return fs.VFSFilesystem(), root.VFSDentry(), nil } -// NewFUSEFilesystem creates a new FUSE filesystem. -func NewFUSEFilesystem(ctx context.Context, devMinor uint32, opts *filesystemOptions, device *vfs.FileDescription) (*filesystem, error) { - fs := &filesystem{ - devMinor: devMinor, - opts: opts, - } - - conn, err := newFUSEConnection(ctx, device, opts.maxActiveRequests) +// newFUSEFilesystem creates a new FUSE filesystem. +func newFUSEFilesystem(ctx context.Context, devMinor uint32, opts *filesystemOptions, device *vfs.FileDescription) (*filesystem, error) { + conn, err := newFUSEConnection(ctx, device, opts) if err != nil { log.Warningf("fuse.NewFUSEFilesystem: NewFUSEConnection failed with error: %v", err) return nil, syserror.EINVAL } - fs.conn = conn fuseFD := device.Impl().(*DeviceFD) + + fs := &filesystem{ + devMinor: devMinor, + opts: opts, + conn: conn, + } + + fs.VFSFilesystem().IncRef() fuseFD.fs = fs return fs, nil @@ -192,11 +231,22 @@ func NewFUSEFilesystem(ctx context.Context, devMinor uint32, opts *filesystemOpt // Release implements vfs.FilesystemImpl.Release. func (fs *filesystem) Release(ctx context.Context) { + fs.conn.fd.mu.Lock() + + fs.umounted = true + fs.conn.Abort(ctx) + // Notify all the waiters on this fd. + fs.conn.fd.waitQueue.Notify(waiter.EventIn) + + fs.conn.fd.mu.Unlock() + fs.Filesystem.VFSFilesystem().VirtualFilesystem().PutAnonBlockDevMinor(fs.devMinor) fs.Filesystem.Release(ctx) } // inode implements kernfs.Inode. +// +// +stateify savable type inode struct { inodeRefs kernfs.InodeAttrs @@ -205,14 +255,50 @@ type inode struct { kernfs.InodeNotSymlink kernfs.OrderedChildren + dentry kernfs.Dentry + + // the owning filesystem. fs is immutable. + fs *filesystem + + // metaDataMu protects the metadata of this inode. + metadataMu sync.Mutex + + nodeID uint64 + locks vfs.FileLocks - dentry kernfs.Dentry + // size of the file. + size uint64 + + // attributeVersion is the version of inode's attributes. + attributeVersion uint64 + + // attributeTime is the remaining vaild time of attributes. + attributeTime uint64 + + // version of the inode. + version uint64 + + // link is result of following a symbolic link. + link string +} + +func (fs *filesystem) newRootInode(creds *auth.Credentials, mode linux.FileMode) *kernfs.Dentry { + i := &inode{fs: fs} + i.InodeAttrs.Init(creds, linux.UNNAMED_MAJOR, fs.devMinor, 1, linux.ModeDirectory|0755) + i.OrderedChildren.Init(kernfs.OrderedChildrenOptions{}) + i.EnableLeakCheck() + i.dentry.Init(i) + i.nodeID = 1 + + return &i.dentry } -func (fs *filesystem) newInode(creds *auth.Credentials, mode linux.FileMode) *kernfs.Dentry { - i := &inode{} - i.InodeAttrs.Init(creds, linux.UNNAMED_MAJOR, fs.devMinor, fs.NextIno(), linux.ModeDirectory|0755) +func (fs *filesystem) newInode(nodeID uint64, attr linux.FUSEAttr) *kernfs.Dentry { + i := &inode{fs: fs, nodeID: nodeID} + creds := auth.Credentials{EffectiveKGID: auth.KGID(attr.UID), EffectiveKUID: auth.KUID(attr.UID)} + i.InodeAttrs.Init(&creds, linux.UNNAMED_MAJOR, fs.devMinor, fs.NextIno(), linux.FileMode(attr.Mode)) + atomic.StoreUint64(&i.size, attr.Size) i.OrderedChildren.Init(kernfs.OrderedChildrenOptions{}) i.EnableLeakCheck() i.dentry.Init(i) @@ -221,14 +307,292 @@ func (fs *filesystem) newInode(creds *auth.Credentials, mode linux.FileMode) *ke } // Open implements kernfs.Inode.Open. -func (i *inode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { - fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &i.OrderedChildren, &i.locks, &opts, kernfs.GenericDirectoryFDOptions{ - SeekEnd: kernfs.SeekEndStaticEntries, - }) +func (i *inode) Open(ctx context.Context, rp *vfs.ResolvingPath, d *kernfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { + isDir := i.InodeAttrs.Mode().IsDir() + // return error if specified to open directory but inode is not a directory. + if !isDir && opts.Mode.IsDir() { + return nil, syserror.ENOTDIR + } + if opts.Flags&linux.O_LARGEFILE == 0 && atomic.LoadUint64(&i.size) > linux.MAX_NON_LFS { + return nil, syserror.EOVERFLOW + } + + var fd *fileDescription + var fdImpl vfs.FileDescriptionImpl + if isDir { + directoryFD := &directoryFD{} + fd = &(directoryFD.fileDescription) + fdImpl = directoryFD + } else { + regularFD := ®ularFileFD{} + fd = &(regularFD.fileDescription) + fdImpl = regularFD + } + // FOPEN_KEEP_CACHE is the defualt flag for noOpen. + fd.OpenFlag = linux.FOPEN_KEEP_CACHE + + // Only send open request when FUSE server support open or is opening a directory. + if !i.fs.conn.noOpen || isDir { + kernelTask := kernel.TaskFromContext(ctx) + if kernelTask == nil { + log.Warningf("fusefs.Inode.Open: couldn't get kernel task from context") + return nil, syserror.EINVAL + } + + // Build the request. + var opcode linux.FUSEOpcode + if isDir { + opcode = linux.FUSE_OPENDIR + } else { + opcode = linux.FUSE_OPEN + } + + in := linux.FUSEOpenIn{Flags: opts.Flags & ^uint32(linux.O_CREAT|linux.O_EXCL|linux.O_NOCTTY)} + if !i.fs.conn.atomicOTrunc { + in.Flags &= ^uint32(linux.O_TRUNC) + } + + req, err := i.fs.conn.NewRequest(auth.CredentialsFromContext(ctx), uint32(kernelTask.ThreadID()), i.nodeID, opcode, &in) + if err != nil { + return nil, err + } + + // Send the request and receive the reply. + res, err := i.fs.conn.Call(kernelTask, req) + if err != nil { + return nil, err + } + if err := res.Error(); err == syserror.ENOSYS && !isDir { + i.fs.conn.noOpen = true + } else if err != nil { + return nil, err + } else { + out := linux.FUSEOpenOut{} + if err := res.UnmarshalPayload(&out); err != nil { + return nil, err + } + + // Process the reply. + fd.OpenFlag = out.OpenFlag + if isDir { + fd.OpenFlag &= ^uint32(linux.FOPEN_DIRECT_IO) + } + + fd.Fh = out.Fh + } + } + + // TODO(gvisor.dev/issue/3234): invalidate mmap after implemented it for FUSE Inode + fd.DirectIO = fd.OpenFlag&linux.FOPEN_DIRECT_IO != 0 + fdOptions := &vfs.FileDescriptionOptions{} + if fd.OpenFlag&linux.FOPEN_NONSEEKABLE != 0 { + fdOptions.DenyPRead = true + fdOptions.DenyPWrite = true + fd.Nonseekable = true + } + + // If we don't send SETATTR before open (which is indicated by atomicOTrunc) + // and O_TRUNC is set, update the inode's version number and clean existing data + // by setting the file size to 0. + if i.fs.conn.atomicOTrunc && opts.Flags&linux.O_TRUNC != 0 { + i.fs.conn.mu.Lock() + i.fs.conn.attributeVersion++ + i.attributeVersion = i.fs.conn.attributeVersion + atomic.StoreUint64(&i.size, 0) + i.fs.conn.mu.Unlock() + i.attributeTime = 0 + } + + if err := fd.vfsfd.Init(fdImpl, opts.Flags, rp.Mount(), d.VFSDentry(), fdOptions); err != nil { + return nil, err + } + return &fd.vfsfd, nil +} + +// Lookup implements kernfs.Inode.Lookup. +func (i *inode) Lookup(ctx context.Context, name string) (*kernfs.Dentry, error) { + in := linux.FUSELookupIn{Name: name} + return i.newEntry(ctx, name, 0, linux.FUSE_LOOKUP, &in) +} + +// IterDirents implements kernfs.Inode.IterDirents. +func (*inode) IterDirents(ctx context.Context, callback vfs.IterDirentsCallback, offset, relOffset int64) (int64, error) { + return offset, nil +} + +// Valid implements kernfs.Inode.Valid. +func (*inode) Valid(ctx context.Context) bool { + return true +} + +// NewFile implements kernfs.Inode.NewFile. +func (i *inode) NewFile(ctx context.Context, name string, opts vfs.OpenOptions) (*kernfs.Dentry, error) { + kernelTask := kernel.TaskFromContext(ctx) + if kernelTask == nil { + log.Warningf("fusefs.Inode.NewFile: couldn't get kernel task from context", i.nodeID) + return nil, syserror.EINVAL + } + in := linux.FUSECreateIn{ + CreateMeta: linux.FUSECreateMeta{ + Flags: opts.Flags, + Mode: uint32(opts.Mode) | linux.S_IFREG, + Umask: uint32(kernelTask.FSContext().Umask()), + }, + Name: name, + } + return i.newEntry(ctx, name, linux.S_IFREG, linux.FUSE_CREATE, &in) +} + +// NewNode implements kernfs.Inode.NewNode. +func (i *inode) NewNode(ctx context.Context, name string, opts vfs.MknodOptions) (*kernfs.Dentry, error) { + in := linux.FUSEMknodIn{ + MknodMeta: linux.FUSEMknodMeta{ + Mode: uint32(opts.Mode), + Rdev: linux.MakeDeviceID(uint16(opts.DevMajor), opts.DevMinor), + Umask: uint32(kernel.TaskFromContext(ctx).FSContext().Umask()), + }, + Name: name, + } + return i.newEntry(ctx, name, opts.Mode.FileType(), linux.FUSE_MKNOD, &in) +} + +// NewSymlink implements kernfs.Inode.NewSymlink. +func (i *inode) NewSymlink(ctx context.Context, name, target string) (*kernfs.Dentry, error) { + in := linux.FUSESymLinkIn{ + Name: name, + Target: target, + } + return i.newEntry(ctx, name, linux.S_IFLNK, linux.FUSE_SYMLINK, &in) +} + +// Unlink implements kernfs.Inode.Unlink. +func (i *inode) Unlink(ctx context.Context, name string, child *kernfs.Dentry) error { + kernelTask := kernel.TaskFromContext(ctx) + if kernelTask == nil { + log.Warningf("fusefs.Inode.newEntry: couldn't get kernel task from context", i.nodeID) + return syserror.EINVAL + } + in := linux.FUSEUnlinkIn{Name: name} + req, err := i.fs.conn.NewRequest(auth.CredentialsFromContext(ctx), uint32(kernelTask.ThreadID()), i.nodeID, linux.FUSE_UNLINK, &in) + if err != nil { + return err + } + res, err := i.fs.conn.Call(kernelTask, req) + if err != nil { + return err + } + // only return error, discard res. + if err := res.Error(); err != nil { + return err + } + return i.dentry.RemoveChildLocked(name, child) +} + +// NewDir implements kernfs.Inode.NewDir. +func (i *inode) NewDir(ctx context.Context, name string, opts vfs.MkdirOptions) (*kernfs.Dentry, error) { + in := linux.FUSEMkdirIn{ + MkdirMeta: linux.FUSEMkdirMeta{ + Mode: uint32(opts.Mode), + Umask: uint32(kernel.TaskFromContext(ctx).FSContext().Umask()), + }, + Name: name, + } + return i.newEntry(ctx, name, linux.S_IFDIR, linux.FUSE_MKDIR, &in) +} + +// RmDir implements kernfs.Inode.RmDir. +func (i *inode) RmDir(ctx context.Context, name string, child *kernfs.Dentry) error { + fusefs := i.fs + task, creds := kernel.TaskFromContext(ctx), auth.CredentialsFromContext(ctx) + + in := linux.FUSERmDirIn{Name: name} + req, err := fusefs.conn.NewRequest(creds, uint32(task.ThreadID()), i.nodeID, linux.FUSE_RMDIR, &in) + if err != nil { + return err + } + + res, err := i.fs.conn.Call(task, req) + if err != nil { + return err + } + if err := res.Error(); err != nil { + return err + } + + return i.dentry.RemoveChildLocked(name, child) +} + +// newEntry calls FUSE server for entry creation and allocates corresponding entry according to response. +// Shared by FUSE_MKNOD, FUSE_MKDIR, FUSE_SYMLINK, FUSE_LINK and FUSE_LOOKUP. +func (i *inode) newEntry(ctx context.Context, name string, fileType linux.FileMode, opcode linux.FUSEOpcode, payload marshal.Marshallable) (*kernfs.Dentry, error) { + kernelTask := kernel.TaskFromContext(ctx) + if kernelTask == nil { + log.Warningf("fusefs.Inode.newEntry: couldn't get kernel task from context", i.nodeID) + return nil, syserror.EINVAL + } + req, err := i.fs.conn.NewRequest(auth.CredentialsFromContext(ctx), uint32(kernelTask.ThreadID()), i.nodeID, opcode, payload) + if err != nil { + return nil, err + } + res, err := i.fs.conn.Call(kernelTask, req) if err != nil { return nil, err } - return fd.VFSFileDescription(), nil + if err := res.Error(); err != nil { + return nil, err + } + out := linux.FUSEEntryOut{} + if err := res.UnmarshalPayload(&out); err != nil { + return nil, err + } + if opcode != linux.FUSE_LOOKUP && ((out.Attr.Mode&linux.S_IFMT)^uint32(fileType) != 0 || out.NodeID == 0 || out.NodeID == linux.FUSE_ROOT_ID) { + return nil, syserror.EIO + } + child := i.fs.newInode(out.NodeID, out.Attr) + return child, nil +} + +// Getlink implements kernfs.Inode.Getlink. +func (i *inode) Getlink(ctx context.Context, mnt *vfs.Mount) (vfs.VirtualDentry, string, error) { + path, err := i.Readlink(ctx, mnt) + return vfs.VirtualDentry{}, path, err +} + +// Readlink implements kernfs.Inode.Readlink. +func (i *inode) Readlink(ctx context.Context, mnt *vfs.Mount) (string, error) { + if i.Mode().FileType()&linux.S_IFLNK == 0 { + return "", syserror.EINVAL + } + if len(i.link) == 0 { + kernelTask := kernel.TaskFromContext(ctx) + if kernelTask == nil { + log.Warningf("fusefs.Inode.Readlink: couldn't get kernel task from context") + return "", syserror.EINVAL + } + req, err := i.fs.conn.NewRequest(auth.CredentialsFromContext(ctx), uint32(kernelTask.ThreadID()), i.nodeID, linux.FUSE_READLINK, &linux.FUSEEmptyIn{}) + if err != nil { + return "", err + } + res, err := i.fs.conn.Call(kernelTask, req) + if err != nil { + return "", err + } + i.link = string(res.data[res.hdr.SizeBytes():]) + if !mnt.Options().ReadOnly { + i.attributeTime = 0 + } + } + return i.link, nil +} + +// getFUSEAttr returns a linux.FUSEAttr of this inode stored in local cache. +// TODO(gvisor.dev/issue/3679): Add support for other fields. +func (i *inode) getFUSEAttr() linux.FUSEAttr { + return linux.FUSEAttr{ + Ino: i.Ino(), + Size: atomic.LoadUint64(&i.size), + Mode: uint32(i.Mode()), + } } // statFromFUSEAttr makes attributes from linux.FUSEAttr to linux.Statx. The @@ -284,50 +648,92 @@ func statFromFUSEAttr(attr linux.FUSEAttr, mask, devMinor uint32) linux.Statx { return stat } -// Stat implements kernfs.Inode.Stat. -func (i *inode) Stat(ctx context.Context, fs *vfs.Filesystem, opts vfs.StatOptions) (linux.Statx, error) { - fusefs := fs.Impl().(*filesystem) - conn := fusefs.conn - task, creds := kernel.TaskFromContext(ctx), auth.CredentialsFromContext(ctx) +// getAttr gets the attribute of this inode by issuing a FUSE_GETATTR request +// or read from local cache. It updates the corresponding attributes if +// necessary. +func (i *inode) getAttr(ctx context.Context, fs *vfs.Filesystem, opts vfs.StatOptions, flags uint32, fh uint64) (linux.FUSEAttr, error) { + attributeVersion := atomic.LoadUint64(&i.fs.conn.attributeVersion) + + // TODO(gvisor.dev/issue/3679): send the request only if + // - invalid local cache for fields specified in the opts.Mask + // - forced update + // - i.attributeTime expired + // If local cache is still valid, return local cache. + // Currently we always send a request, + // and we always set the metadata with the new result, + // unless attributeVersion has changed. + + task := kernel.TaskFromContext(ctx) if task == nil { log.Warningf("couldn't get kernel task from context") - return linux.Statx{}, syserror.EINVAL + return linux.FUSEAttr{}, syserror.EINVAL } - var in linux.FUSEGetAttrIn - // We don't set any attribute in the request, because in VFS2 fstat(2) will - // finally be translated into vfs.FilesystemImpl.StatAt() (see - // pkg/sentry/syscalls/linux/vfs2/stat.go), resulting in the same flow - // as stat(2). Thus GetAttrFlags and Fh variable will never be used in VFS2. - req, err := conn.NewRequest(creds, uint32(task.ThreadID()), i.Ino(), linux.FUSE_GETATTR, &in) + creds := auth.CredentialsFromContext(ctx) + + in := linux.FUSEGetAttrIn{ + GetAttrFlags: flags, + Fh: fh, + } + req, err := i.fs.conn.NewRequest(creds, uint32(task.ThreadID()), i.nodeID, linux.FUSE_GETATTR, &in) if err != nil { - return linux.Statx{}, err + return linux.FUSEAttr{}, err } - res, err := conn.Call(task, req) + res, err := i.fs.conn.Call(task, req) if err != nil { - return linux.Statx{}, err + return linux.FUSEAttr{}, err } if err := res.Error(); err != nil { - return linux.Statx{}, err + return linux.FUSEAttr{}, err } var out linux.FUSEGetAttrOut if err := res.UnmarshalPayload(&out); err != nil { - return linux.Statx{}, err + return linux.FUSEAttr{}, err + } + + // Local version is newer, return the local one. + // Skip the update. + if attributeVersion != 0 && atomic.LoadUint64(&i.attributeVersion) > attributeVersion { + return i.getFUSEAttr(), nil } - // Set all metadata into kernfs.InodeAttrs. - if err := i.SetStat(ctx, fs, creds, vfs.SetStatOptions{ - Stat: statFromFUSEAttr(out.Attr, linux.STATX_ALL, fusefs.devMinor), + // Set the metadata of kernfs.InodeAttrs. + if err := i.SetInodeStat(ctx, fs, creds, vfs.SetStatOptions{ + Stat: statFromFUSEAttr(out.Attr, linux.STATX_ALL, i.fs.devMinor), }); err != nil { + return linux.FUSEAttr{}, err + } + + // Set the size if no error (after SetStat() check). + atomic.StoreUint64(&i.size, out.Attr.Size) + + return out.Attr, nil +} + +// reviseAttr attempts to update the attributes for internal purposes +// by calling getAttr with a pre-specified mask. +// Used by read, write, lseek. +func (i *inode) reviseAttr(ctx context.Context, flags uint32, fh uint64) error { + // Never need atime for internal purposes. + _, err := i.getAttr(ctx, i.fs.VFSFilesystem(), vfs.StatOptions{ + Mask: linux.STATX_BASIC_STATS &^ linux.STATX_ATIME, + }, flags, fh) + return err +} + +// Stat implements kernfs.Inode.Stat. +func (i *inode) Stat(ctx context.Context, fs *vfs.Filesystem, opts vfs.StatOptions) (linux.Statx, error) { + attr, err := i.getAttr(ctx, fs, opts, 0, 0) + if err != nil { return linux.Statx{}, err } - return statFromFUSEAttr(out.Attr, opts.Mask, fusefs.devMinor), nil + return statFromFUSEAttr(attr, opts.Mask, i.fs.devMinor), nil } -// DecRef implements kernfs.Inode. +// DecRef implements kernfs.Inode.DecRef. func (i *inode) DecRef(context.Context) { i.inodeRefs.DecRef(i.Destroy) } @@ -337,3 +743,84 @@ func (i *inode) StatFS(ctx context.Context, fs *vfs.Filesystem) (linux.Statfs, e // TODO(gvisor.dev/issues/3413): Complete the implementation of statfs. return vfs.GenericStatFS(linux.FUSE_SUPER_MAGIC), nil } + +// fattrMaskFromStats converts vfs.SetStatOptions.Stat.Mask to linux stats mask +// aligned with the attribute mask defined in include/linux/fs.h. +func fattrMaskFromStats(mask uint32) uint32 { + var fuseAttrMask uint32 + maskMap := map[uint32]uint32{ + linux.STATX_MODE: linux.FATTR_MODE, + linux.STATX_UID: linux.FATTR_UID, + linux.STATX_GID: linux.FATTR_GID, + linux.STATX_SIZE: linux.FATTR_SIZE, + linux.STATX_ATIME: linux.FATTR_ATIME, + linux.STATX_MTIME: linux.FATTR_MTIME, + linux.STATX_CTIME: linux.FATTR_CTIME, + } + for statxMask, fattrMask := range maskMap { + if mask&statxMask != 0 { + fuseAttrMask |= fattrMask + } + } + return fuseAttrMask +} + +// SetStat implements kernfs.Inode.SetStat. +func (i *inode) SetStat(ctx context.Context, fs *vfs.Filesystem, creds *auth.Credentials, opts vfs.SetStatOptions) error { + return i.setAttr(ctx, fs, creds, opts, false, 0) +} + +func (i *inode) setAttr(ctx context.Context, fs *vfs.Filesystem, creds *auth.Credentials, opts vfs.SetStatOptions, useFh bool, fh uint64) error { + conn := i.fs.conn + task := kernel.TaskFromContext(ctx) + if task == nil { + log.Warningf("couldn't get kernel task from context") + return syserror.EINVAL + } + + // We should retain the original file type when assigning new mode. + fileType := uint16(i.Mode()) & linux.S_IFMT + fattrMask := fattrMaskFromStats(opts.Stat.Mask) + if useFh { + fattrMask |= linux.FATTR_FH + } + in := linux.FUSESetAttrIn{ + Valid: fattrMask, + Fh: fh, + Size: opts.Stat.Size, + Atime: uint64(opts.Stat.Atime.Sec), + Mtime: uint64(opts.Stat.Mtime.Sec), + Ctime: uint64(opts.Stat.Ctime.Sec), + AtimeNsec: opts.Stat.Atime.Nsec, + MtimeNsec: opts.Stat.Mtime.Nsec, + CtimeNsec: opts.Stat.Ctime.Nsec, + Mode: uint32(fileType | opts.Stat.Mode), + UID: opts.Stat.UID, + GID: opts.Stat.GID, + } + req, err := conn.NewRequest(creds, uint32(task.ThreadID()), i.nodeID, linux.FUSE_SETATTR, &in) + if err != nil { + return err + } + + res, err := conn.Call(task, req) + if err != nil { + return err + } + if err := res.Error(); err != nil { + return err + } + out := linux.FUSEGetAttrOut{} + if err := res.UnmarshalPayload(&out); err != nil { + return err + } + + // Set the metadata of kernfs.InodeAttrs. + if err := i.SetInodeStat(ctx, fs, creds, vfs.SetStatOptions{ + Stat: statFromFUSEAttr(out.Attr, linux.STATX_ALL, i.fs.devMinor), + }); err != nil { + return err + } + + return nil +} diff --git a/pkg/sentry/fsimpl/fuse/read_write.go b/pkg/sentry/fsimpl/fuse/read_write.go new file mode 100644 index 000000000..625d1547f --- /dev/null +++ b/pkg/sentry/fsimpl/fuse/read_write.go @@ -0,0 +1,242 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package fuse + +import ( + "io" + "sync/atomic" + + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/log" + "gvisor.dev/gvisor/pkg/sentry/kernel" + "gvisor.dev/gvisor/pkg/sentry/kernel/auth" + "gvisor.dev/gvisor/pkg/syserror" + "gvisor.dev/gvisor/pkg/usermem" +) + +// ReadInPages sends FUSE_READ requests for the size after round it up to +// a multiple of page size, blocks on it for reply, processes the reply +// and returns the payload (or joined payloads) as a byte slice. +// This is used for the general purpose reading. +// We do not support direct IO (which read the exact number of bytes) +// at this moment. +func (fs *filesystem) ReadInPages(ctx context.Context, fd *regularFileFD, off uint64, size uint32) ([][]byte, uint32, error) { + attributeVersion := atomic.LoadUint64(&fs.conn.attributeVersion) + + t := kernel.TaskFromContext(ctx) + if t == nil { + log.Warningf("fusefs.Read: couldn't get kernel task from context") + return nil, 0, syserror.EINVAL + } + + // Round up to a multiple of page size. + readSize, _ := usermem.PageRoundUp(uint64(size)) + + // One request cannnot exceed either maxRead or maxPages. + maxPages := fs.conn.maxRead >> usermem.PageShift + if maxPages > uint32(fs.conn.maxPages) { + maxPages = uint32(fs.conn.maxPages) + } + + var outs [][]byte + var sizeRead uint32 + + // readSize is a multiple of usermem.PageSize. + // Always request bytes as a multiple of pages. + pagesRead, pagesToRead := uint32(0), uint32(readSize>>usermem.PageShift) + + // Reuse the same struct for unmarshalling to avoid unnecessary memory allocation. + in := linux.FUSEReadIn{ + Fh: fd.Fh, + LockOwner: 0, // TODO(gvisor.dev/issue/3245): file lock + ReadFlags: 0, // TODO(gvisor.dev/issue/3245): |= linux.FUSE_READ_LOCKOWNER + Flags: fd.statusFlags(), + } + + // This loop is intended for fragmented read where the bytes to read is + // larger than either the maxPages or maxRead. + // For the majority of reads with normal size, this loop should only + // execute once. + for pagesRead < pagesToRead { + pagesCanRead := pagesToRead - pagesRead + if pagesCanRead > maxPages { + pagesCanRead = maxPages + } + + in.Offset = off + (uint64(pagesRead) << usermem.PageShift) + in.Size = pagesCanRead << usermem.PageShift + + req, err := fs.conn.NewRequest(auth.CredentialsFromContext(ctx), uint32(t.ThreadID()), fd.inode().nodeID, linux.FUSE_READ, &in) + if err != nil { + return nil, 0, err + } + + // TODO(gvisor.dev/issue/3247): support async read. + + res, err := fs.conn.Call(t, req) + if err != nil { + return nil, 0, err + } + if err := res.Error(); err != nil { + return nil, 0, err + } + + // Not enough bytes in response, + // either we reached EOF, + // or the FUSE server sends back a response + // that cannot even fit the hdr. + if len(res.data) <= res.hdr.SizeBytes() { + // We treat both case as EOF here for now + // since there is no reliable way to detect + // the over-short hdr case. + break + } + + // Directly using the slice to avoid extra copy. + out := res.data[res.hdr.SizeBytes():] + + outs = append(outs, out) + sizeRead += uint32(len(out)) + + pagesRead += pagesCanRead + } + + defer fs.ReadCallback(ctx, fd, off, size, sizeRead, attributeVersion) + + // No bytes returned: offset >= EOF. + if len(outs) == 0 { + return nil, 0, io.EOF + } + + return outs, sizeRead, nil +} + +// ReadCallback updates several information after receiving a read response. +// Due to readahead, sizeRead can be larger than size. +func (fs *filesystem) ReadCallback(ctx context.Context, fd *regularFileFD, off uint64, size uint32, sizeRead uint32, attributeVersion uint64) { + // TODO(gvisor.dev/issue/3247): support async read. + // If this is called by an async read, correctly process it. + // May need to update the signature. + + i := fd.inode() + // TODO(gvisor.dev/issue/1193): Invalidate or update atime. + + // Reached EOF. + if sizeRead < size { + // TODO(gvisor.dev/issue/3630): If we have writeback cache, then we need to fill this hole. + // Might need to update the buf to be returned from the Read(). + + // Update existing size. + newSize := off + uint64(sizeRead) + fs.conn.mu.Lock() + if attributeVersion == i.attributeVersion && newSize < atomic.LoadUint64(&i.size) { + fs.conn.attributeVersion++ + i.attributeVersion = i.fs.conn.attributeVersion + atomic.StoreUint64(&i.size, newSize) + } + fs.conn.mu.Unlock() + } +} + +// Write sends FUSE_WRITE requests and return the bytes +// written according to the response. +// +// Preconditions: len(data) == size. +func (fs *filesystem) Write(ctx context.Context, fd *regularFileFD, off uint64, size uint32, data []byte) (uint32, error) { + t := kernel.TaskFromContext(ctx) + if t == nil { + log.Warningf("fusefs.Read: couldn't get kernel task from context") + return 0, syserror.EINVAL + } + + // One request cannnot exceed either maxWrite or maxPages. + maxWrite := uint32(fs.conn.maxPages) << usermem.PageShift + if maxWrite > fs.conn.maxWrite { + maxWrite = fs.conn.maxWrite + } + + // Reuse the same struct for unmarshalling to avoid unnecessary memory allocation. + in := linux.FUSEWriteIn{ + Fh: fd.Fh, + // TODO(gvisor.dev/issue/3245): file lock + LockOwner: 0, + // TODO(gvisor.dev/issue/3245): |= linux.FUSE_READ_LOCKOWNER + // TODO(gvisor.dev/issue/3237): |= linux.FUSE_WRITE_CACHE (not added yet) + WriteFlags: 0, + Flags: fd.statusFlags(), + } + + var written uint32 + + // This loop is intended for fragmented write where the bytes to write is + // larger than either the maxWrite or maxPages or when bigWrites is false. + // Unless a small value for max_write is explicitly used, this loop + // is expected to execute only once for the majority of the writes. + for written < size { + toWrite := size - written + + // Limit the write size to one page. + // Note that the bigWrites flag is obsolete, + // latest libfuse always sets it on. + if !fs.conn.bigWrites && toWrite > usermem.PageSize { + toWrite = usermem.PageSize + } + + // Limit the write size to maxWrite. + if toWrite > maxWrite { + toWrite = maxWrite + } + + in.Offset = off + uint64(written) + in.Size = toWrite + + req, err := fs.conn.NewRequest(auth.CredentialsFromContext(ctx), uint32(t.ThreadID()), fd.inode().nodeID, linux.FUSE_WRITE, &in) + if err != nil { + return 0, err + } + + req.payload = data[written : written+toWrite] + + // TODO(gvisor.dev/issue/3247): support async write. + + res, err := fs.conn.Call(t, req) + if err != nil { + return 0, err + } + if err := res.Error(); err != nil { + return 0, err + } + + out := linux.FUSEWriteOut{} + if err := res.UnmarshalPayload(&out); err != nil { + return 0, err + } + + // Write more than requested? EIO. + if out.Size > toWrite { + return 0, syserror.EIO + } + + written += out.Size + + // Break if short write. Not necessarily an error. + if out.Size != toWrite { + break + } + } + + return written, nil +} diff --git a/pkg/sentry/fsimpl/fuse/regular_file.go b/pkg/sentry/fsimpl/fuse/regular_file.go new file mode 100644 index 000000000..5bdd096c3 --- /dev/null +++ b/pkg/sentry/fsimpl/fuse/regular_file.go @@ -0,0 +1,230 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package fuse + +import ( + "io" + "math" + "sync" + "sync/atomic" + + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/sentry/vfs" + "gvisor.dev/gvisor/pkg/syserror" + "gvisor.dev/gvisor/pkg/usermem" +) + +type regularFileFD struct { + fileDescription + + // off is the file offset. + off int64 + // offMu protects off. + offMu sync.Mutex +} + +// PRead implements vfs.FileDescriptionImpl.PRead. +func (fd *regularFileFD) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) { + if offset < 0 { + return 0, syserror.EINVAL + } + + // Check that flags are supported. + // + // TODO(gvisor.dev/issue/2601): Support select preadv2 flags. + if opts.Flags&^linux.RWF_HIPRI != 0 { + return 0, syserror.EOPNOTSUPP + } + + size := dst.NumBytes() + if size == 0 { + // Early return if count is 0. + return 0, nil + } else if size > math.MaxUint32 { + // FUSE only supports uint32 for size. + // Overflow. + return 0, syserror.EINVAL + } + + // TODO(gvisor.dev/issue/3678): Add direct IO support. + + inode := fd.inode() + + // Reading beyond EOF, update file size if outdated. + if uint64(offset+size) > atomic.LoadUint64(&inode.size) { + if err := inode.reviseAttr(ctx, linux.FUSE_GETATTR_FH, fd.Fh); err != nil { + return 0, err + } + // If the offset after update is still too large, return error. + if uint64(offset) >= atomic.LoadUint64(&inode.size) { + return 0, io.EOF + } + } + + // Truncate the read with updated file size. + fileSize := atomic.LoadUint64(&inode.size) + if uint64(offset+size) > fileSize { + size = int64(fileSize) - offset + } + + buffers, n, err := inode.fs.ReadInPages(ctx, fd, uint64(offset), uint32(size)) + if err != nil { + return 0, err + } + + // TODO(gvisor.dev/issue/3237): support indirect IO (e.g. caching), + // store the bytes that were read ahead. + + // Update the number of bytes to copy for short read. + if n < uint32(size) { + size = int64(n) + } + + // Copy the bytes read to the dst. + // This loop is intended for fragmented reads. + // For the majority of reads, this loop only execute once. + var copied int64 + for _, buffer := range buffers { + toCopy := int64(len(buffer)) + if copied+toCopy > size { + toCopy = size - copied + } + cp, err := dst.DropFirst64(copied).CopyOut(ctx, buffer[:toCopy]) + if err != nil { + return 0, err + } + if int64(cp) != toCopy { + return 0, syserror.EIO + } + copied += toCopy + } + + return copied, nil +} + +// Read implements vfs.FileDescriptionImpl.Read. +func (fd *regularFileFD) Read(ctx context.Context, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) { + fd.offMu.Lock() + n, err := fd.PRead(ctx, dst, fd.off, opts) + fd.off += n + fd.offMu.Unlock() + return n, err +} + +// PWrite implements vfs.FileDescriptionImpl.PWrite. +func (fd *regularFileFD) PWrite(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) { + n, _, err := fd.pwrite(ctx, src, offset, opts) + return n, err +} + +// Write implements vfs.FileDescriptionImpl.Write. +func (fd *regularFileFD) Write(ctx context.Context, src usermem.IOSequence, opts vfs.WriteOptions) (int64, error) { + fd.offMu.Lock() + n, off, err := fd.pwrite(ctx, src, fd.off, opts) + fd.off = off + fd.offMu.Unlock() + return n, err +} + +// pwrite returns the number of bytes written, final offset and error. The +// final offset should be ignored by PWrite. +func (fd *regularFileFD) pwrite(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (written, finalOff int64, err error) { + if offset < 0 { + return 0, offset, syserror.EINVAL + } + + // Check that flags are supported. + // + // TODO(gvisor.dev/issue/2601): Support select preadv2 flags. + if opts.Flags&^linux.RWF_HIPRI != 0 { + return 0, offset, syserror.EOPNOTSUPP + } + + inode := fd.inode() + inode.metadataMu.Lock() + defer inode.metadataMu.Unlock() + + // If the file is opened with O_APPEND, update offset to file size. + // Note: since our Open() implements the interface of kernfs, + // and kernfs currently does not support O_APPEND, this will never + // be true before we switch out from kernfs. + if fd.vfsfd.StatusFlags()&linux.O_APPEND != 0 { + // Locking inode.metadataMu is sufficient for reading size + offset = int64(inode.size) + } + + srclen := src.NumBytes() + + if srclen > math.MaxUint32 { + // FUSE only supports uint32 for size. + // Overflow. + return 0, offset, syserror.EINVAL + } + if end := offset + srclen; end < offset { + // Overflow. + return 0, offset, syserror.EINVAL + } + + srclen, err = vfs.CheckLimit(ctx, offset, srclen) + if err != nil { + return 0, offset, err + } + + if srclen == 0 { + // Return before causing any side effects. + return 0, offset, nil + } + + src = src.TakeFirst64(srclen) + + // TODO(gvisor.dev/issue/3237): Add cache support: + // buffer cache. Ideally we write from src to our buffer cache first. + // The slice passed to fs.Write() should be a slice from buffer cache. + data := make([]byte, srclen) + // Reason for making a copy here: connection.Call() blocks on kerneltask, + // which in turn acquires mm.activeMu lock. Functions like CopyInTo() will + // attemp to acquire the mm.activeMu lock as well -> deadlock. + // We must finish reading from the userspace memory before + // t.Block() deactivates it. + cp, err := src.CopyIn(ctx, data) + if err != nil { + return 0, offset, err + } + if int64(cp) != srclen { + return 0, offset, syserror.EIO + } + + n, err := fd.inode().fs.Write(ctx, fd, uint64(offset), uint32(srclen), data) + if err != nil { + return 0, offset, err + } + + if n == 0 { + // We have checked srclen != 0 previously. + // If err == nil, then it's a short write and we return EIO. + return 0, offset, syserror.EIO + } + + written = int64(n) + finalOff = offset + written + + if finalOff > int64(inode.size) { + atomic.StoreUint64(&inode.size, uint64(finalOff)) + atomic.AddUint64(&inode.fs.conn.attributeVersion, 1) + } + + return +} diff --git a/pkg/sentry/fsimpl/fuse/request_response.go b/pkg/sentry/fsimpl/fuse/request_response.go new file mode 100644 index 000000000..7fa00569b --- /dev/null +++ b/pkg/sentry/fsimpl/fuse/request_response.go @@ -0,0 +1,229 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package fuse + +import ( + "fmt" + "syscall" + + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/marshal" + "gvisor.dev/gvisor/pkg/sentry/kernel" + "gvisor.dev/gvisor/pkg/sentry/kernel/auth" + "gvisor.dev/gvisor/pkg/usermem" +) + +// fuseInitRes is a variable-length wrapper of linux.FUSEInitOut. The FUSE +// server may implement an older version of FUSE protocol, which contains a +// linux.FUSEInitOut with less attributes. +// +// Dynamically-sized objects cannot be marshalled. +type fuseInitRes struct { + marshal.StubMarshallable + + // initOut contains the response from the FUSE server. + initOut linux.FUSEInitOut + + // initLen is the total length of bytes of the response. + initLen uint32 +} + +// UnmarshalBytes deserializes src to the initOut attribute in a fuseInitRes. +func (r *fuseInitRes) UnmarshalBytes(src []byte) { + out := &r.initOut + + // Introduced before FUSE kernel version 7.13. + out.Major = uint32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + out.Minor = uint32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + out.MaxReadahead = uint32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + out.Flags = uint32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + out.MaxBackground = uint16(usermem.ByteOrder.Uint16(src[:2])) + src = src[2:] + out.CongestionThreshold = uint16(usermem.ByteOrder.Uint16(src[:2])) + src = src[2:] + out.MaxWrite = uint32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + + // Introduced in FUSE kernel version 7.23. + if len(src) >= 4 { + out.TimeGran = uint32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + } + // Introduced in FUSE kernel version 7.28. + if len(src) >= 2 { + out.MaxPages = uint16(usermem.ByteOrder.Uint16(src[:2])) + src = src[2:] + } +} + +// SizeBytes is the size of the payload of the FUSE_INIT response. +func (r *fuseInitRes) SizeBytes() int { + return int(r.initLen) +} + +// Ordinary requests have even IDs, while interrupts IDs are odd. +// Used to increment the unique ID for each FUSE request. +var reqIDStep uint64 = 2 + +// Request represents a FUSE operation request that hasn't been sent to the +// server yet. +// +// +stateify savable +type Request struct { + requestEntry + + id linux.FUSEOpID + hdr *linux.FUSEHeaderIn + data []byte + + // payload for this request: extra bytes to write after + // the data slice. Used by FUSE_WRITE. + payload []byte + + // If this request is async. + async bool + // If we don't care its response. + // Manually set by the caller. + noReply bool +} + +// NewRequest creates a new request that can be sent to the FUSE server. +func (conn *connection) NewRequest(creds *auth.Credentials, pid uint32, ino uint64, opcode linux.FUSEOpcode, payload marshal.Marshallable) (*Request, error) { + conn.fd.mu.Lock() + defer conn.fd.mu.Unlock() + conn.fd.nextOpID += linux.FUSEOpID(reqIDStep) + + hdrLen := (*linux.FUSEHeaderIn)(nil).SizeBytes() + hdr := linux.FUSEHeaderIn{ + Len: uint32(hdrLen + payload.SizeBytes()), + Opcode: opcode, + Unique: conn.fd.nextOpID, + NodeID: ino, + UID: uint32(creds.EffectiveKUID), + GID: uint32(creds.EffectiveKGID), + PID: pid, + } + + buf := make([]byte, hdr.Len) + + // TODO(gVisor.dev/issue/3698): Use the unsafe version once go_marshal is safe to use again. + hdr.MarshalBytes(buf[:hdrLen]) + payload.MarshalBytes(buf[hdrLen:]) + + return &Request{ + id: hdr.Unique, + hdr: &hdr, + data: buf, + }, nil +} + +// futureResponse represents an in-flight request, that may or may not have +// completed yet. Convert it to a resolved Response by calling Resolve, but note +// that this may block. +// +// +stateify savable +type futureResponse struct { + opcode linux.FUSEOpcode + ch chan struct{} + hdr *linux.FUSEHeaderOut + data []byte + + // If this request is async. + async bool +} + +// newFutureResponse creates a future response to a FUSE request. +func newFutureResponse(req *Request) *futureResponse { + return &futureResponse{ + opcode: req.hdr.Opcode, + ch: make(chan struct{}), + async: req.async, + } +} + +// resolve blocks the task until the server responds to its corresponding request, +// then returns a resolved response. +func (f *futureResponse) resolve(t *kernel.Task) (*Response, error) { + // Return directly for async requests. + if f.async { + return nil, nil + } + + if err := t.Block(f.ch); err != nil { + return nil, err + } + + return f.getResponse(), nil +} + +// getResponse creates a Response from the data the futureResponse has. +func (f *futureResponse) getResponse() *Response { + return &Response{ + opcode: f.opcode, + hdr: *f.hdr, + data: f.data, + } +} + +// Response represents an actual response from the server, including the +// response payload. +// +// +stateify savable +type Response struct { + opcode linux.FUSEOpcode + hdr linux.FUSEHeaderOut + data []byte +} + +// Error returns the error of the FUSE call. +func (r *Response) Error() error { + errno := r.hdr.Error + if errno >= 0 { + return nil + } + + sysErrNo := syscall.Errno(-errno) + return error(sysErrNo) +} + +// DataLen returns the size of the response without the header. +func (r *Response) DataLen() uint32 { + return r.hdr.Len - uint32(r.hdr.SizeBytes()) +} + +// UnmarshalPayload unmarshals the response data into m. +func (r *Response) UnmarshalPayload(m marshal.Marshallable) error { + hdrLen := r.hdr.SizeBytes() + haveDataLen := r.hdr.Len - uint32(hdrLen) + wantDataLen := uint32(m.SizeBytes()) + + if haveDataLen < wantDataLen { + return fmt.Errorf("payload too small. Minimum data lenth required: %d, but got data length %d", wantDataLen, haveDataLen) + } + + // The response data is empty unless there is some payload. And so, doesn't + // need to be unmarshalled. + if r.data == nil { + return nil + } + + // TODO(gVisor.dev/issue/3698): Use the unsafe version once go_marshal is safe to use again. + m.UnmarshalBytes(r.data[hdrLen:]) + return nil +} diff --git a/pkg/sentry/fsimpl/fuse/utils_test.go b/pkg/sentry/fsimpl/fuse/utils_test.go new file mode 100644 index 000000000..e1d9e3365 --- /dev/null +++ b/pkg/sentry/fsimpl/fuse/utils_test.go @@ -0,0 +1,132 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package fuse + +import ( + "io" + "testing" + + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/marshal" + "gvisor.dev/gvisor/pkg/sentry/fsimpl/testutil" + "gvisor.dev/gvisor/pkg/sentry/kernel" + "gvisor.dev/gvisor/pkg/sentry/kernel/auth" + "gvisor.dev/gvisor/pkg/sentry/vfs" + "gvisor.dev/gvisor/pkg/usermem" +) + +func setup(t *testing.T) *testutil.System { + k, err := testutil.Boot() + if err != nil { + t.Fatalf("Error creating kernel: %v", err) + } + + ctx := k.SupervisorContext() + creds := auth.CredentialsFromContext(ctx) + + k.VFS().MustRegisterFilesystemType(Name, &FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{ + AllowUserList: true, + AllowUserMount: true, + }) + + mntns, err := k.VFS().NewMountNamespace(ctx, creds, "", "tmpfs", &vfs.MountOptions{}) + if err != nil { + t.Fatalf("NewMountNamespace(): %v", err) + } + + return testutil.NewSystem(ctx, t, k.VFS(), mntns) +} + +// newTestConnection creates a fuse connection that the sentry can communicate with +// and the FD for the server to communicate with. +func newTestConnection(system *testutil.System, k *kernel.Kernel, maxActiveRequests uint64) (*connection, *vfs.FileDescription, error) { + vfsObj := &vfs.VirtualFilesystem{} + fuseDev := &DeviceFD{} + + if err := vfsObj.Init(system.Ctx); err != nil { + return nil, nil, err + } + + vd := vfsObj.NewAnonVirtualDentry("genCountFD") + defer vd.DecRef(system.Ctx) + if err := fuseDev.vfsfd.Init(fuseDev, linux.O_RDWR|linux.O_CREAT, vd.Mount(), vd.Dentry(), &vfs.FileDescriptionOptions{}); err != nil { + return nil, nil, err + } + + fsopts := filesystemOptions{ + maxActiveRequests: maxActiveRequests, + } + fs, err := newFUSEFilesystem(system.Ctx, 0, &fsopts, &fuseDev.vfsfd) + if err != nil { + return nil, nil, err + } + + return fs.conn, &fuseDev.vfsfd, nil +} + +type testPayload struct { + marshal.StubMarshallable + data uint32 +} + +// SizeBytes implements marshal.Marshallable.SizeBytes. +func (t *testPayload) SizeBytes() int { + return 4 +} + +// MarshalBytes implements marshal.Marshallable.MarshalBytes. +func (t *testPayload) MarshalBytes(dst []byte) { + usermem.ByteOrder.PutUint32(dst[:4], t.data) +} + +// UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes. +func (t *testPayload) UnmarshalBytes(src []byte) { + *t = testPayload{data: usermem.ByteOrder.Uint32(src[:4])} +} + +// Packed implements marshal.Marshallable.Packed. +func (t *testPayload) Packed() bool { + return true +} + +// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe. +func (t *testPayload) MarshalUnsafe(dst []byte) { + t.MarshalBytes(dst) +} + +// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe. +func (t *testPayload) UnmarshalUnsafe(src []byte) { + t.UnmarshalBytes(src) +} + +// CopyOutN implements marshal.Marshallable.CopyOutN. +func (t *testPayload) CopyOutN(task marshal.CopyContext, addr usermem.Addr, limit int) (int, error) { + panic("not implemented") +} + +// CopyOut implements marshal.Marshallable.CopyOut. +func (t *testPayload) CopyOut(task marshal.CopyContext, addr usermem.Addr) (int, error) { + panic("not implemented") +} + +// CopyIn implements marshal.Marshallable.CopyIn. +func (t *testPayload) CopyIn(task marshal.CopyContext, addr usermem.Addr) (int, error) { + panic("not implemented") +} + +// WriteTo implements io.WriterTo.WriteTo. +func (t *testPayload) WriteTo(w io.Writer) (int64, error) { + panic("not implemented") +} diff --git a/pkg/sentry/fsimpl/gofer/directory.go b/pkg/sentry/fsimpl/gofer/directory.go index 91d2ae199..18c884b59 100644 --- a/pkg/sentry/fsimpl/gofer/directory.go +++ b/pkg/sentry/fsimpl/gofer/directory.go @@ -117,11 +117,12 @@ func (d *dentry) createSyntheticChildLocked(opts *createSyntheticOpts) { d.syntheticChildren++ } +// +stateify savable type directoryFD struct { fileDescription vfs.DirectoryFileDescriptionDefaultImpl - mu sync.Mutex + mu sync.Mutex `state:"nosave"` off int64 dirents []vfs.Dirent } diff --git a/pkg/sentry/fsimpl/gofer/filesystem.go b/pkg/sentry/fsimpl/gofer/filesystem.go index 5d0f487db..94d96261b 100644 --- a/pkg/sentry/fsimpl/gofer/filesystem.go +++ b/pkg/sentry/fsimpl/gofer/filesystem.go @@ -1026,7 +1026,7 @@ func (d *dentry) open(ctx context.Context, rp *vfs.ResolvingPath, opts *vfs.Open // step is required even if !d.cachedMetadataAuthoritative() because // d.mappings has to be updated. // d.metadataMu has already been acquired if trunc == true. - d.updateFileSizeLocked(0) + d.updateSizeLocked(0) if d.cachedMetadataAuthoritative() { d.touchCMtimeLocked() @@ -1311,6 +1311,9 @@ func (fs *filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa if !renamed.isDir() { return syserror.EISDIR } + if genericIsAncestorDentry(replaced, renamed) { + return syserror.ENOTEMPTY + } } else { if rp.MustBeDir() || renamed.isDir() { return syserror.ENOTDIR @@ -1361,14 +1364,15 @@ func (fs *filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa // with reference counts and queue oldParent for checkCachingLocked if the // parent isn't actually changing. if oldParent != newParent { + oldParent.decRefLocked() ds = appendDentry(ds, oldParent) newParent.IncRef() if renamed.isSynthetic() { oldParent.syntheticChildren-- newParent.syntheticChildren++ } + renamed.parent = newParent } - renamed.parent = newParent renamed.name = newName if newParent.children == nil { newParent.children = make(map[string]*dentry) @@ -1412,11 +1416,11 @@ func (fs *filesystem) SetStatAt(ctx context.Context, rp *vfs.ResolvingPath, opts fs.renameMuRUnlockAndCheckCaching(ctx, &ds) return err } - if err := d.setStat(ctx, rp.Credentials(), &opts, rp.Mount()); err != nil { - fs.renameMuRUnlockAndCheckCaching(ctx, &ds) + err = d.setStat(ctx, rp.Credentials(), &opts, rp.Mount()) + fs.renameMuRUnlockAndCheckCaching(ctx, &ds) + if err != nil { return err } - fs.renameMuRUnlockAndCheckCaching(ctx, &ds) if ev := vfs.InotifyEventFromStatMask(opts.Stat.Mask); ev != 0 { d.InotifyWithParent(ctx, ev, 0, vfs.InodeEvent) @@ -1491,7 +1495,7 @@ func (fs *filesystem) UnlinkAt(ctx context.Context, rp *vfs.ResolvingPath) error return fs.unlinkAt(ctx, rp, false /* dir */) } -// BoundEndpointAt implements FilesystemImpl.BoundEndpointAt. +// BoundEndpointAt implements vfs.FilesystemImpl.BoundEndpointAt. func (fs *filesystem) BoundEndpointAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.BoundEndpointOptions) (transport.BoundEndpoint, error) { var ds *[]*dentry fs.renameMu.RLock() @@ -1519,8 +1523,8 @@ func (fs *filesystem) BoundEndpointAt(ctx context.Context, rp *vfs.ResolvingPath return nil, syserror.ECONNREFUSED } -// ListxattrAt implements vfs.FilesystemImpl.ListxattrAt. -func (fs *filesystem) ListxattrAt(ctx context.Context, rp *vfs.ResolvingPath, size uint64) ([]string, error) { +// ListXattrAt implements vfs.FilesystemImpl.ListXattrAt. +func (fs *filesystem) ListXattrAt(ctx context.Context, rp *vfs.ResolvingPath, size uint64) ([]string, error) { var ds *[]*dentry fs.renameMu.RLock() defer fs.renameMuRUnlockAndCheckCaching(ctx, &ds) @@ -1528,11 +1532,11 @@ func (fs *filesystem) ListxattrAt(ctx context.Context, rp *vfs.ResolvingPath, si if err != nil { return nil, err } - return d.listxattr(ctx, rp.Credentials(), size) + return d.listXattr(ctx, rp.Credentials(), size) } -// GetxattrAt implements vfs.FilesystemImpl.GetxattrAt. -func (fs *filesystem) GetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.GetxattrOptions) (string, error) { +// GetXattrAt implements vfs.FilesystemImpl.GetXattrAt. +func (fs *filesystem) GetXattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.GetXattrOptions) (string, error) { var ds *[]*dentry fs.renameMu.RLock() defer fs.renameMuRUnlockAndCheckCaching(ctx, &ds) @@ -1540,11 +1544,11 @@ func (fs *filesystem) GetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opt if err != nil { return "", err } - return d.getxattr(ctx, rp.Credentials(), &opts) + return d.getXattr(ctx, rp.Credentials(), &opts) } -// SetxattrAt implements vfs.FilesystemImpl.SetxattrAt. -func (fs *filesystem) SetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.SetxattrOptions) error { +// SetXattrAt implements vfs.FilesystemImpl.SetXattrAt. +func (fs *filesystem) SetXattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.SetXattrOptions) error { var ds *[]*dentry fs.renameMu.RLock() d, err := fs.resolveLocked(ctx, rp, &ds) @@ -1552,18 +1556,18 @@ func (fs *filesystem) SetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opt fs.renameMuRUnlockAndCheckCaching(ctx, &ds) return err } - if err := d.setxattr(ctx, rp.Credentials(), &opts); err != nil { - fs.renameMuRUnlockAndCheckCaching(ctx, &ds) + err = d.setXattr(ctx, rp.Credentials(), &opts) + fs.renameMuRUnlockAndCheckCaching(ctx, &ds) + if err != nil { return err } - fs.renameMuRUnlockAndCheckCaching(ctx, &ds) d.InotifyWithParent(ctx, linux.IN_ATTRIB, 0, vfs.InodeEvent) return nil } -// RemovexattrAt implements vfs.FilesystemImpl.RemovexattrAt. -func (fs *filesystem) RemovexattrAt(ctx context.Context, rp *vfs.ResolvingPath, name string) error { +// RemoveXattrAt implements vfs.FilesystemImpl.RemoveXattrAt. +func (fs *filesystem) RemoveXattrAt(ctx context.Context, rp *vfs.ResolvingPath, name string) error { var ds *[]*dentry fs.renameMu.RLock() d, err := fs.resolveLocked(ctx, rp, &ds) @@ -1571,11 +1575,11 @@ func (fs *filesystem) RemovexattrAt(ctx context.Context, rp *vfs.ResolvingPath, fs.renameMuRUnlockAndCheckCaching(ctx, &ds) return err } - if err := d.removexattr(ctx, rp.Credentials(), name); err != nil { - fs.renameMuRUnlockAndCheckCaching(ctx, &ds) + err = d.removeXattr(ctx, rp.Credentials(), name) + fs.renameMuRUnlockAndCheckCaching(ctx, &ds) + if err != nil { return err } - fs.renameMuRUnlockAndCheckCaching(ctx, &ds) d.InotifyWithParent(ctx, linux.IN_ATTRIB, 0, vfs.InodeEvent) return nil diff --git a/pkg/sentry/fsimpl/gofer/gofer.go b/pkg/sentry/fsimpl/gofer/gofer.go index 57bff1789..8608471f8 100644 --- a/pkg/sentry/fsimpl/gofer/gofer.go +++ b/pkg/sentry/fsimpl/gofer/gofer.go @@ -62,9 +62,13 @@ import ( const Name = "9p" // FilesystemType implements vfs.FilesystemType. +// +// +stateify savable type FilesystemType struct{} // filesystem implements vfs.FilesystemImpl. +// +// +stateify savable type filesystem struct { vfsfs vfs.Filesystem @@ -77,7 +81,7 @@ type filesystem struct { iopts InternalFilesystemOptions // client is the client used by this filesystem. client is immutable. - client *p9.Client + client *p9.Client `state:"nosave"` // FIXME(gvisor.dev/issue/1663): not yet supported. // clock is a realtime clock used to set timestamps in file operations. clock ktime.Clock @@ -95,7 +99,7 @@ type filesystem struct { // reference count (such that it is usable as vfs.ResolvingPath.Start() or // is reachable from its children), or if it is a child dentry (such that // it is reachable from its parent). - renameMu sync.RWMutex + renameMu sync.RWMutex `state:"nosave"` // cachedDentries contains all dentries with 0 references. (Due to race // conditions, it may also contain dentries with non-zero references.) @@ -107,7 +111,7 @@ type filesystem struct { // syncableDentries contains all dentries in this filesystem for which // !dentry.file.isNil(). specialFileFDs contains all open specialFileFDs. // These fields are protected by syncMu. - syncMu sync.Mutex + syncMu sync.Mutex `state:"nosave"` syncableDentries map[*dentry]struct{} specialFileFDs map[*specialFileFD]struct{} @@ -120,6 +124,8 @@ type filesystem struct { // dentries, it comes from QID.Path from the 9P server. Synthetic dentries // have have their inodeNumber generated sequentially, with the MSB reserved to // prevent conflicts with regular dentries. +// +// +stateify savable type inodeNumber uint64 // Reserve MSB for synthetic mounts. @@ -132,6 +138,7 @@ func inoFromPath(path uint64) inodeNumber { return inodeNumber(path &^ syntheticInoMask) } +// +stateify savable type filesystemOptions struct { // "Standard" 9P options. fd int @@ -177,6 +184,8 @@ type filesystemOptions struct { // InteropMode controls the client's interaction with other remote filesystem // users. +// +// +stateify savable type InteropMode uint32 const ( @@ -195,11 +204,7 @@ const ( // and consistent with Linux's semantics (in particular, it is not always // possible for clients to set arbitrary atimes and mtimes depending on the // remote filesystem implementation, and never possible for clients to set - // arbitrary ctimes.) If a dentry containing a client-defined atime or - // mtime is evicted from cache, client timestamps will be sent to the - // remote filesystem on a best-effort basis to attempt to ensure that - // timestamps will be preserved when another dentry representing the same - // file is instantiated. + // arbitrary ctimes.) InteropModeExclusive InteropMode = iota // InteropModeWritethrough is appropriate when there are read-only users of @@ -239,6 +244,8 @@ const ( // InternalFilesystemOptions may be passed as // vfs.GetFilesystemOptions.InternalData to FilesystemType.GetFilesystem. +// +// +stateify savable type InternalFilesystemOptions struct { // If LeakConnection is true, do not close the connection to the server // when the Filesystem is released. This is necessary for deployments in @@ -538,6 +545,8 @@ func (fs *filesystem) Release(ctx context.Context) { } // dentry implements vfs.DentryImpl. +// +// +stateify savable type dentry struct { vfsd vfs.Dentry @@ -567,7 +576,7 @@ type dentry struct { // If file.isNil(), this dentry represents a synthetic file, i.e. a file // that does not exist on the remote filesystem. As of this writing, the // only files that can be synthetic are sockets, pipes, and directories. - file p9file + file p9file `state:"nosave"` // FIXME(gvisor.dev/issue/1663): not yet supported. // If deleted is non-zero, the file represented by this dentry has been // deleted. deleted is accessed using atomic memory operations. @@ -579,7 +588,7 @@ type dentry struct { cached bool dentryEntry - dirMu sync.Mutex + dirMu sync.Mutex `state:"nosave"` // If this dentry represents a directory, children contains: // @@ -611,7 +620,7 @@ type dentry struct { // To mutate: // - Lock metadataMu and use atomic operations to update because we might // have atomic readers that don't hold the lock. - metadataMu sync.Mutex + metadataMu sync.Mutex `state:"nosave"` ino inodeNumber // immutable mode uint32 // type is immutable, perms are mutable uid uint32 // auth.KUID, but stored as raw uint32 for sync/atomic @@ -642,7 +651,7 @@ type dentry struct { // other metadata fields. nlink uint32 - mapsMu sync.Mutex + mapsMu sync.Mutex `state:"nosave"` // If this dentry represents a regular file, mappings tracks mappings of // the file into memmap.MappingSpaces. mappings is protected by mapsMu. @@ -666,12 +675,12 @@ type dentry struct { // either p9.File transitions from closed (isNil() == true) to open // (isNil() == false), it may be mutated with handleMu locked, but cannot // be closed until the dentry is destroyed. - handleMu sync.RWMutex - readFile p9file - writeFile p9file + handleMu sync.RWMutex `state:"nosave"` + readFile p9file `state:"nosave"` // FIXME(gvisor.dev/issue/1663): not yet supported. + writeFile p9file `state:"nosave"` // FIXME(gvisor.dev/issue/1663): not yet supported. hostFD int32 - dataMu sync.RWMutex + dataMu sync.RWMutex `state:"nosave"` // If this dentry represents a regular file that is client-cached, cache // maps offsets into the cached file to offsets into @@ -837,7 +846,7 @@ func (d *dentry) updateFromP9AttrsLocked(mask p9.AttrMask, attr *p9.Attr) { atomic.StoreUint32(&d.nlink, uint32(attr.NLink)) } if mask.Size { - d.updateFileSizeLocked(attr.Size) + d.updateSizeLocked(attr.Size) } } @@ -991,7 +1000,7 @@ func (d *dentry) setStat(ctx context.Context, creds *auth.Credentials, opts *vfs // d.size should be kept up to date, and privatized // copy-on-write mappings of truncated pages need to be // invalidated, even if InteropModeShared is in effect. - d.updateFileSizeLocked(stat.Size) + d.updateSizeLocked(stat.Size) } } if d.fs.opts.interop == InteropModeShared { @@ -1028,8 +1037,31 @@ func (d *dentry) setStat(ctx context.Context, creds *auth.Credentials, opts *vfs return nil } +// doAllocate performs an allocate operation on d. Note that d.metadataMu will +// be held when allocate is called. +func (d *dentry) doAllocate(ctx context.Context, offset, length uint64, allocate func() error) error { + d.metadataMu.Lock() + defer d.metadataMu.Unlock() + + // Allocating a smaller size is a noop. + size := offset + length + if d.cachedMetadataAuthoritative() && size <= d.size { + return nil + } + + err := allocate() + if err != nil { + return err + } + d.updateSizeLocked(size) + if d.cachedMetadataAuthoritative() { + d.touchCMtimeLocked() + } + return nil +} + // Preconditions: d.metadataMu must be locked. -func (d *dentry) updateFileSizeLocked(newSize uint64) { +func (d *dentry) updateSizeLocked(newSize uint64) { d.dataMu.Lock() oldSize := d.size atomic.StoreUint64(&d.size, newSize) @@ -1067,6 +1099,21 @@ func (d *dentry) checkPermissions(creds *auth.Credentials, ats vfs.AccessTypes) return vfs.GenericCheckPermissions(creds, ats, linux.FileMode(atomic.LoadUint32(&d.mode)), auth.KUID(atomic.LoadUint32(&d.uid)), auth.KGID(atomic.LoadUint32(&d.gid))) } +func (d *dentry) checkXattrPermissions(creds *auth.Credentials, name string, ats vfs.AccessTypes) error { + // We only support xattrs prefixed with "user." (see b/148380782). Currently, + // there is no need to expose any other xattrs through a gofer. + if !strings.HasPrefix(name, linux.XATTR_USER_PREFIX) { + return syserror.EOPNOTSUPP + } + mode := linux.FileMode(atomic.LoadUint32(&d.mode)) + kuid := auth.KUID(atomic.LoadUint32(&d.uid)) + kgid := auth.KGID(atomic.LoadUint32(&d.gid)) + if err := vfs.GenericCheckPermissions(creds, ats, mode, kuid, kgid); err != nil { + return err + } + return vfs.CheckXattrPermissions(creds, ats, mode, kuid, name) +} + func (d *dentry) mayDelete(creds *auth.Credentials, child *dentry) error { return vfs.CheckDeleteSticky(creds, linux.FileMode(atomic.LoadUint32(&d.mode)), auth.KUID(atomic.LoadUint32(&child.uid))) } @@ -1300,30 +1347,19 @@ func (d *dentry) destroyLocked(ctx context.Context) { d.handleMu.Unlock() if !d.file.isNil() { - if !d.isDeleted() { - // Write dirty timestamps back to the remote filesystem. - atimeDirty := atomic.LoadUint32(&d.atimeDirty) != 0 - mtimeDirty := atomic.LoadUint32(&d.mtimeDirty) != 0 - if atimeDirty || mtimeDirty { - atime := atomic.LoadInt64(&d.atime) - mtime := atomic.LoadInt64(&d.mtime) - if err := d.file.setAttr(ctx, p9.SetAttrMask{ - ATime: atimeDirty, - ATimeNotSystemTime: atimeDirty, - MTime: mtimeDirty, - MTimeNotSystemTime: mtimeDirty, - }, p9.SetAttr{ - ATimeSeconds: uint64(atime / 1e9), - ATimeNanoSeconds: uint64(atime % 1e9), - MTimeSeconds: uint64(mtime / 1e9), - MTimeNanoSeconds: uint64(mtime % 1e9), - }); err != nil { - log.Warningf("gofer.dentry.destroyLocked: failed to write dirty timestamps back: %v", err) - } - } + // Note that it's possible that d.atimeDirty or d.mtimeDirty are true, + // i.e. client and server timestamps may differ (because e.g. a client + // write was serviced by the page cache, and only written back to the + // remote file later). Ideally, we'd write client timestamps back to + // the remote filesystem so that timestamps for a new dentry + // instantiated for the same file would remain coherent. Unfortunately, + // this turns out to be too expensive in many cases, so for now we + // don't do this. + if err := d.file.close(ctx); err != nil { + log.Warningf("gofer.dentry.destroyLocked: failed to close file: %v", err) } - d.file.close(ctx) d.file = p9file{} + // Remove d from the set of syncable dentries. d.fs.syncMu.Lock() delete(d.fs.syncableDentries, d) @@ -1351,9 +1387,7 @@ func (d *dentry) setDeleted() { atomic.StoreUint32(&d.deleted, 1) } -// We only support xattrs prefixed with "user." (see b/148380782). Currently, -// there is no need to expose any other xattrs through a gofer. -func (d *dentry) listxattr(ctx context.Context, creds *auth.Credentials, size uint64) ([]string, error) { +func (d *dentry) listXattr(ctx context.Context, creds *auth.Credentials, size uint64) ([]string, error) { if d.file.isNil() || !d.userXattrSupported() { return nil, nil } @@ -1363,6 +1397,7 @@ func (d *dentry) listxattr(ctx context.Context, creds *auth.Credentials, size ui } xattrs := make([]string, 0, len(xattrMap)) for x := range xattrMap { + // We only support xattrs in the user.* namespace. if strings.HasPrefix(x, linux.XATTR_USER_PREFIX) { xattrs = append(xattrs, x) } @@ -1370,51 +1405,33 @@ func (d *dentry) listxattr(ctx context.Context, creds *auth.Credentials, size ui return xattrs, nil } -func (d *dentry) getxattr(ctx context.Context, creds *auth.Credentials, opts *vfs.GetxattrOptions) (string, error) { +func (d *dentry) getXattr(ctx context.Context, creds *auth.Credentials, opts *vfs.GetXattrOptions) (string, error) { if d.file.isNil() { return "", syserror.ENODATA } - if err := d.checkPermissions(creds, vfs.MayRead); err != nil { + if err := d.checkXattrPermissions(creds, opts.Name, vfs.MayRead); err != nil { return "", err } - if !strings.HasPrefix(opts.Name, linux.XATTR_USER_PREFIX) { - return "", syserror.EOPNOTSUPP - } - if !d.userXattrSupported() { - return "", syserror.ENODATA - } return d.file.getXattr(ctx, opts.Name, opts.Size) } -func (d *dentry) setxattr(ctx context.Context, creds *auth.Credentials, opts *vfs.SetxattrOptions) error { +func (d *dentry) setXattr(ctx context.Context, creds *auth.Credentials, opts *vfs.SetXattrOptions) error { if d.file.isNil() { return syserror.EPERM } - if err := d.checkPermissions(creds, vfs.MayWrite); err != nil { + if err := d.checkXattrPermissions(creds, opts.Name, vfs.MayWrite); err != nil { return err } - if !strings.HasPrefix(opts.Name, linux.XATTR_USER_PREFIX) { - return syserror.EOPNOTSUPP - } - if !d.userXattrSupported() { - return syserror.EPERM - } return d.file.setXattr(ctx, opts.Name, opts.Value, opts.Flags) } -func (d *dentry) removexattr(ctx context.Context, creds *auth.Credentials, name string) error { +func (d *dentry) removeXattr(ctx context.Context, creds *auth.Credentials, name string) error { if d.file.isNil() { return syserror.EPERM } - if err := d.checkPermissions(creds, vfs.MayWrite); err != nil { + if err := d.checkXattrPermissions(creds, name, vfs.MayWrite); err != nil { return err } - if !strings.HasPrefix(name, linux.XATTR_USER_PREFIX) { - return syserror.EOPNOTSUPP - } - if !d.userXattrSupported() { - return syserror.EPERM - } return d.file.removeXattr(ctx, name) } @@ -1623,12 +1640,14 @@ func (d *dentry) decLinks() { // fileDescription is embedded by gofer implementations of // vfs.FileDescriptionImpl. +// +// +stateify savable type fileDescription struct { vfsfd vfs.FileDescription vfs.FileDescriptionDefaultImpl vfs.LockFD - lockLogging sync.Once + lockLogging sync.Once `state:"nosave"` // FIXME(gvisor.dev/issue/1663): not yet supported. } func (fd *fileDescription) filesystem() *filesystem { @@ -1666,30 +1685,30 @@ func (fd *fileDescription) SetStat(ctx context.Context, opts vfs.SetStatOptions) return nil } -// Listxattr implements vfs.FileDescriptionImpl.Listxattr. -func (fd *fileDescription) Listxattr(ctx context.Context, size uint64) ([]string, error) { - return fd.dentry().listxattr(ctx, auth.CredentialsFromContext(ctx), size) +// ListXattr implements vfs.FileDescriptionImpl.ListXattr. +func (fd *fileDescription) ListXattr(ctx context.Context, size uint64) ([]string, error) { + return fd.dentry().listXattr(ctx, auth.CredentialsFromContext(ctx), size) } -// Getxattr implements vfs.FileDescriptionImpl.Getxattr. -func (fd *fileDescription) Getxattr(ctx context.Context, opts vfs.GetxattrOptions) (string, error) { - return fd.dentry().getxattr(ctx, auth.CredentialsFromContext(ctx), &opts) +// GetXattr implements vfs.FileDescriptionImpl.GetXattr. +func (fd *fileDescription) GetXattr(ctx context.Context, opts vfs.GetXattrOptions) (string, error) { + return fd.dentry().getXattr(ctx, auth.CredentialsFromContext(ctx), &opts) } -// Setxattr implements vfs.FileDescriptionImpl.Setxattr. -func (fd *fileDescription) Setxattr(ctx context.Context, opts vfs.SetxattrOptions) error { +// SetXattr implements vfs.FileDescriptionImpl.SetXattr. +func (fd *fileDescription) SetXattr(ctx context.Context, opts vfs.SetXattrOptions) error { d := fd.dentry() - if err := d.setxattr(ctx, auth.CredentialsFromContext(ctx), &opts); err != nil { + if err := d.setXattr(ctx, auth.CredentialsFromContext(ctx), &opts); err != nil { return err } d.InotifyWithParent(ctx, linux.IN_ATTRIB, 0, vfs.InodeEvent) return nil } -// Removexattr implements vfs.FileDescriptionImpl.Removexattr. -func (fd *fileDescription) Removexattr(ctx context.Context, name string) error { +// RemoveXattr implements vfs.FileDescriptionImpl.RemoveXattr. +func (fd *fileDescription) RemoveXattr(ctx context.Context, name string) error { d := fd.dentry() - if err := d.removexattr(ctx, auth.CredentialsFromContext(ctx), name); err != nil { + if err := d.removeXattr(ctx, auth.CredentialsFromContext(ctx), name); err != nil { return err } d.InotifyWithParent(ctx, linux.IN_ATTRIB, 0, vfs.InodeEvent) diff --git a/pkg/sentry/fsimpl/gofer/handle.go b/pkg/sentry/fsimpl/gofer/handle.go index 104157512..a9ebe1206 100644 --- a/pkg/sentry/fsimpl/gofer/handle.go +++ b/pkg/sentry/fsimpl/gofer/handle.go @@ -25,6 +25,8 @@ import ( // handle represents a remote "open file descriptor", consisting of an opened // fid (p9.File) and optionally a host file descriptor. +// +// These are explicitly not savable. type handle struct { file p9file fd int32 // -1 if unavailable diff --git a/pkg/sentry/fsimpl/gofer/p9file.go b/pkg/sentry/fsimpl/gofer/p9file.go index 87f0b877f..21b4a96fe 100644 --- a/pkg/sentry/fsimpl/gofer/p9file.go +++ b/pkg/sentry/fsimpl/gofer/p9file.go @@ -127,6 +127,13 @@ func (f p9file) close(ctx context.Context) error { return err } +func (f p9file) setAttrClose(ctx context.Context, valid p9.SetAttrMask, attr p9.SetAttr) error { + ctx.UninterruptibleSleepStart(false) + err := f.file.SetAttrClose(valid, attr) + ctx.UninterruptibleSleepFinish(false) + return err +} + func (f p9file) open(ctx context.Context, flags p9.OpenFlags) (*fd.FD, p9.QID, uint32, error) { ctx.UninterruptibleSleepStart(false) fdobj, qid, iounit, err := f.file.Open(flags) diff --git a/pkg/sentry/fsimpl/gofer/regular_file.go b/pkg/sentry/fsimpl/gofer/regular_file.go index a2e9342d5..eeaf6e444 100644 --- a/pkg/sentry/fsimpl/gofer/regular_file.go +++ b/pkg/sentry/fsimpl/gofer/regular_file.go @@ -39,11 +39,12 @@ func (d *dentry) isRegularFile() bool { return d.fileType() == linux.S_IFREG } +// +stateify savable type regularFileFD struct { fileDescription // off is the file offset. off is protected by mu. - mu sync.Mutex + mu sync.Mutex `state:"nosave"` off int64 } @@ -79,28 +80,11 @@ func (fd *regularFileFD) OnClose(ctx context.Context) error { // Allocate implements vfs.FileDescriptionImpl.Allocate. func (fd *regularFileFD) Allocate(ctx context.Context, mode, offset, length uint64) error { d := fd.dentry() - d.metadataMu.Lock() - defer d.metadataMu.Unlock() - - // Allocating a smaller size is a noop. - size := offset + length - if d.cachedMetadataAuthoritative() && size <= d.size { - return nil - } - - d.handleMu.RLock() - err := d.writeFile.allocate(ctx, p9.ToAllocateMode(mode), offset, length) - d.handleMu.RUnlock() - if err != nil { - return err - } - d.dataMu.Lock() - atomic.StoreUint64(&d.size, size) - d.dataMu.Unlock() - if d.cachedMetadataAuthoritative() { - d.touchCMtimeLocked() - } - return nil + return d.doAllocate(ctx, offset, length, func() error { + d.handleMu.RLock() + defer d.handleMu.RUnlock() + return d.writeFile.allocate(ctx, p9.ToAllocateMode(mode), offset, length) + }) } // PRead implements vfs.FileDescriptionImpl.PRead. @@ -915,6 +899,8 @@ func (d *dentry) Evict(ctx context.Context, er pgalloc.EvictableRange) { // dentryPlatformFile is only used when a host FD representing the remote file // is available (i.e. dentry.hostFD >= 0), and that FD is used for application // memory mappings (i.e. !filesystem.opts.forcePageCache). +// +// +stateify savable type dentryPlatformFile struct { *dentry @@ -927,7 +913,7 @@ type dentryPlatformFile struct { hostFileMapper fsutil.HostFileMapper // hostFileMapperInitOnce is used to lazily initialize hostFileMapper. - hostFileMapperInitOnce sync.Once + hostFileMapperInitOnce sync.Once `state:"nosave"` // FIXME(gvisor.dev/issue/1663): not yet supported. } // IncRef implements memmap.File.IncRef. diff --git a/pkg/sentry/fsimpl/gofer/socket.go b/pkg/sentry/fsimpl/gofer/socket.go index 85d2bee72..326b940a7 100644 --- a/pkg/sentry/fsimpl/gofer/socket.go +++ b/pkg/sentry/fsimpl/gofer/socket.go @@ -36,12 +36,14 @@ func (d *dentry) isSocket() bool { // An endpoint's lifetime is the time between when filesystem.BoundEndpointAt() // is called and either BoundEndpoint.BidirectionalConnect or // BoundEndpoint.UnidirectionalConnect is called. +// +// +stateify savable type endpoint struct { // dentry is the filesystem dentry which produced this endpoint. dentry *dentry // file is the p9 file that contains a single unopened fid. - file p9.File + file p9.File `state:"nosave"` // FIXME(gvisor.dev/issue/1663): not yet supported. // path is the sentry path where this endpoint is bound. path string diff --git a/pkg/sentry/fsimpl/gofer/special_file.go b/pkg/sentry/fsimpl/gofer/special_file.go index 3c39aa9b7..71581736c 100644 --- a/pkg/sentry/fsimpl/gofer/special_file.go +++ b/pkg/sentry/fsimpl/gofer/special_file.go @@ -22,6 +22,7 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/fdnotifier" + "gvisor.dev/gvisor/pkg/p9" "gvisor.dev/gvisor/pkg/safemem" "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/syserror" @@ -33,11 +34,13 @@ import ( // special files, and (when filesystemOptions.regularFilesUseSpecialFileFD is // in effect) regular files. specialFileFD differs from regularFileFD by using // per-FD handles instead of shared per-dentry handles, and never buffering I/O. +// +// +stateify savable type specialFileFD struct { fileDescription // handle is used for file I/O. handle is immutable. - handle handle + handle handle `state:"nosave"` // FIXME(gvisor.dev/issue/1663): not yet supported. // isRegularFile is true if this FD represents a regular file which is only // possible when filesystemOptions.regularFilesUseSpecialFileFD is in @@ -55,7 +58,7 @@ type specialFileFD struct { queue waiter.Queue // If seekable is true, off is the file offset. off is protected by mu. - mu sync.Mutex + mu sync.Mutex `state:"nosave"` off int64 } @@ -135,6 +138,16 @@ func (fd *specialFileFD) EventUnregister(e *waiter.Entry) { fd.fileDescription.EventUnregister(e) } +func (fd *specialFileFD) Allocate(ctx context.Context, mode, offset, length uint64) error { + if fd.isRegularFile { + d := fd.dentry() + return d.doAllocate(ctx, offset, length, func() error { + return fd.handle.file.allocate(ctx, p9.ToAllocateMode(mode), offset, length) + }) + } + return fd.FileDescriptionDefaultImpl.Allocate(ctx, mode, offset, length) +} + // PRead implements vfs.FileDescriptionImpl.PRead. func (fd *specialFileFD) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) { if fd.seekable && offset < 0 { @@ -235,11 +248,12 @@ func (fd *specialFileFD) pwrite(ctx context.Context, src usermem.IOSequence, off d.touchCMtime() } buf := make([]byte, src.NumBytes()) - // Don't do partial writes if we get a partial read from src. - if _, err := src.CopyIn(ctx, buf); err != nil { - return 0, offset, err + copied, copyErr := src.CopyIn(ctx, buf) + if copied == 0 && copyErr != nil { + // Only return the error if we didn't get any data. + return 0, offset, copyErr } - n, err := fd.handle.writeFromBlocksAt(ctx, safemem.BlockSeqOf(safemem.BlockFromSafeSlice(buf)), uint64(offset)) + n, err := fd.handle.writeFromBlocksAt(ctx, safemem.BlockSeqOf(safemem.BlockFromSafeSlice(buf[:copied])), uint64(offset)) if err == syserror.EAGAIN { err = syserror.ErrWouldBlock } @@ -256,7 +270,10 @@ func (fd *specialFileFD) pwrite(ctx context.Context, src usermem.IOSequence, off atomic.StoreUint64(&d.size, uint64(offset)) } } - return int64(n), offset, err + if err != nil { + return int64(n), offset, err + } + return int64(n), offset, copyErr } // Write implements vfs.FileDescriptionImpl.Write. diff --git a/pkg/sentry/fsimpl/host/BUILD b/pkg/sentry/fsimpl/host/BUILD index be1c88c82..56bcf9bdb 100644 --- a/pkg/sentry/fsimpl/host/BUILD +++ b/pkg/sentry/fsimpl/host/BUILD @@ -49,6 +49,7 @@ go_library( "//pkg/fspath", "//pkg/iovec", "//pkg/log", + "//pkg/marshal/primitive", "//pkg/refs", "//pkg/safemem", "//pkg/sentry/arch", @@ -72,7 +73,6 @@ go_library( "//pkg/unet", "//pkg/usermem", "//pkg/waiter", - "//tools/go_marshal/primitive", "@org_golang_x_sys//unix:go_default_library", ], ) diff --git a/pkg/sentry/fsimpl/host/host.go b/pkg/sentry/fsimpl/host/host.go index 7561f821c..ffe4ddb32 100644 --- a/pkg/sentry/fsimpl/host/host.go +++ b/pkg/sentry/fsimpl/host/host.go @@ -58,7 +58,7 @@ func newInode(fs *filesystem, hostFD int, fileType linux.FileMode, isTTY bool) ( canMap: fileType == linux.S_IFREG, } i.pf.inode = i - i.refs.EnableLeakCheck() + i.EnableLeakCheck() // Non-seekable files can't be memory mapped, assert this. if !i.seekable && i.canMap { @@ -126,7 +126,7 @@ func NewFD(ctx context.Context, mnt *vfs.Mount, hostFD int, opts *NewFDOptions) // For simplicity, fileDescription.offset is set to 0. Technically, we // should only set to 0 on files that are not seekable (sockets, pipes, // etc.), and use the offset from the host fd otherwise when importing. - return i.open(ctx, d.VFSDentry(), mnt, flags) + return i.open(ctx, d, mnt, flags) } // ImportFD sets up and returns a vfs.FileDescription from a donated fd. @@ -137,14 +137,16 @@ func ImportFD(ctx context.Context, mnt *vfs.Mount, hostFD int, isTTY bool) (*vfs } // filesystemType implements vfs.FilesystemType. +// +// +stateify savable type filesystemType struct{} -// GetFilesystem implements FilesystemType.GetFilesystem. +// GetFilesystem implements vfs.FilesystemType.GetFilesystem. func (filesystemType) GetFilesystem(context.Context, *vfs.VirtualFilesystem, *auth.Credentials, string, vfs.GetFilesystemOptions) (*vfs.Filesystem, *vfs.Dentry, error) { panic("host.filesystemType.GetFilesystem should never be called") } -// Name implements FilesystemType.Name. +// Name implements vfs.FilesystemType.Name. func (filesystemType) Name() string { return "none" } @@ -166,6 +168,8 @@ func NewFilesystem(vfsObj *vfs.VirtualFilesystem) (*vfs.Filesystem, error) { } // filesystem implements vfs.FilesystemImpl. +// +// +stateify savable type filesystem struct { kernfs.Filesystem @@ -185,6 +189,8 @@ func (fs *filesystem) PrependPath(ctx context.Context, vfsroot, vd vfs.VirtualDe } // inode implements kernfs.Inode. +// +// +stateify savable type inode struct { kernfs.InodeNoStatFS kernfs.InodeNotDirectory @@ -193,7 +199,7 @@ type inode struct { locks vfs.FileLocks // When the reference count reaches zero, the host fd is closed. - refs inodeRefs + inodeRefs // hostFD contains the host fd that this file was originally created from, // which must be available at time of restore. @@ -233,7 +239,7 @@ type inode struct { canMap bool // mapsMu protects mappings. - mapsMu sync.Mutex + mapsMu sync.Mutex `state:"nosave"` // If canMap is true, mappings tracks mappings of hostFD into // memmap.MappingSpaces. @@ -243,7 +249,7 @@ type inode struct { pf inodePlatformFile } -// CheckPermissions implements kernfs.Inode. +// CheckPermissions implements kernfs.Inode.CheckPermissions. func (i *inode) CheckPermissions(ctx context.Context, creds *auth.Credentials, ats vfs.AccessTypes) error { var s syscall.Stat_t if err := syscall.Fstat(i.hostFD, &s); err != nil { @@ -252,7 +258,7 @@ func (i *inode) CheckPermissions(ctx context.Context, creds *auth.Credentials, a return vfs.GenericCheckPermissions(creds, ats, linux.FileMode(s.Mode), auth.KUID(s.Uid), auth.KGID(s.Gid)) } -// Mode implements kernfs.Inode. +// Mode implements kernfs.Inode.Mode. func (i *inode) Mode() linux.FileMode { var s syscall.Stat_t if err := syscall.Fstat(i.hostFD, &s); err != nil { @@ -263,7 +269,7 @@ func (i *inode) Mode() linux.FileMode { return linux.FileMode(s.Mode) } -// Stat implements kernfs.Inode. +// Stat implements kernfs.Inode.Stat. func (i *inode) Stat(ctx context.Context, vfsfs *vfs.Filesystem, opts vfs.StatOptions) (linux.Statx, error) { if opts.Mask&linux.STATX__RESERVED != 0 { return linux.Statx{}, syserror.EINVAL @@ -376,7 +382,7 @@ func (i *inode) fstat(fs *filesystem) (linux.Statx, error) { }, nil } -// SetStat implements kernfs.Inode. +// SetStat implements kernfs.Inode.SetStat. func (i *inode) SetStat(ctx context.Context, fs *vfs.Filesystem, creds *auth.Credentials, opts vfs.SetStatOptions) error { s := &opts.Stat @@ -435,19 +441,9 @@ func (i *inode) SetStat(ctx context.Context, fs *vfs.Filesystem, creds *auth.Cre return nil } -// IncRef implements kernfs.Inode. -func (i *inode) IncRef() { - i.refs.IncRef() -} - -// TryIncRef implements kernfs.Inode. -func (i *inode) TryIncRef() bool { - return i.refs.TryIncRef() -} - -// DecRef implements kernfs.Inode. +// DecRef implements kernfs.Inode.DecRef. func (i *inode) DecRef(ctx context.Context) { - i.refs.DecRef(func() { + i.inodeRefs.DecRef(func() { if i.wouldBlock { fdnotifier.RemoveFD(int32(i.hostFD)) } @@ -457,16 +453,16 @@ func (i *inode) DecRef(ctx context.Context) { }) } -// Open implements kernfs.Inode. -func (i *inode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { +// Open implements kernfs.Inode.Open. +func (i *inode) Open(ctx context.Context, rp *vfs.ResolvingPath, d *kernfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { // Once created, we cannot re-open a socket fd through /proc/[pid]/fd/. if i.Mode().FileType() == linux.S_IFSOCK { return nil, syserror.ENXIO } - return i.open(ctx, vfsd, rp.Mount(), opts.Flags) + return i.open(ctx, d, rp.Mount(), opts.Flags) } -func (i *inode) open(ctx context.Context, d *vfs.Dentry, mnt *vfs.Mount, flags uint32) (*vfs.FileDescription, error) { +func (i *inode) open(ctx context.Context, d *kernfs.Dentry, mnt *vfs.Mount, flags uint32) (*vfs.FileDescription, error) { var s syscall.Stat_t if err := syscall.Fstat(i.hostFD, &s); err != nil { return nil, err @@ -490,17 +486,17 @@ func (i *inode) open(ctx context.Context, d *vfs.Dentry, mnt *vfs.Mount, flags u return nil, err } // Currently, we only allow Unix sockets to be imported. - return unixsocket.NewFileDescription(ep, ep.Type(), flags, mnt, d, &i.locks) + return unixsocket.NewFileDescription(ep, ep.Type(), flags, mnt, d.VFSDentry(), &i.locks) case syscall.S_IFREG, syscall.S_IFIFO, syscall.S_IFCHR: if i.isTTY { fd := &TTYFileDescription{ fileDescription: fileDescription{inode: i}, - termios: linux.DefaultSlaveTermios, + termios: linux.DefaultReplicaTermios, } fd.LockFD.Init(&i.locks) vfsfd := &fd.vfsfd - if err := vfsfd.Init(fd, flags, mnt, d, &vfs.FileDescriptionOptions{}); err != nil { + if err := vfsfd.Init(fd, flags, mnt, d.VFSDentry(), &vfs.FileDescriptionOptions{}); err != nil { return nil, err } return vfsfd, nil @@ -509,7 +505,7 @@ func (i *inode) open(ctx context.Context, d *vfs.Dentry, mnt *vfs.Mount, flags u fd := &fileDescription{inode: i} fd.LockFD.Init(&i.locks) vfsfd := &fd.vfsfd - if err := vfsfd.Init(fd, flags, mnt, d, &vfs.FileDescriptionOptions{}); err != nil { + if err := vfsfd.Init(fd, flags, mnt, d.VFSDentry(), &vfs.FileDescriptionOptions{}); err != nil { return nil, err } return vfsfd, nil @@ -521,6 +517,8 @@ func (i *inode) open(ctx context.Context, d *vfs.Dentry, mnt *vfs.Mount, flags u } // fileDescription is embedded by host fd implementations of FileDescriptionImpl. +// +// +stateify savable type fileDescription struct { vfsfd vfs.FileDescription vfs.FileDescriptionDefaultImpl @@ -535,40 +533,35 @@ type fileDescription struct { inode *inode // offsetMu protects offset. - offsetMu sync.Mutex + offsetMu sync.Mutex `state:"nosave"` // offset specifies the current file offset. It is only meaningful when // inode.seekable is true. offset int64 } -// SetStat implements vfs.FileDescriptionImpl. +// SetStat implements vfs.FileDescriptionImpl.SetStat. func (f *fileDescription) SetStat(ctx context.Context, opts vfs.SetStatOptions) error { creds := auth.CredentialsFromContext(ctx) return f.inode.SetStat(ctx, f.vfsfd.Mount().Filesystem(), creds, opts) } -// Stat implements vfs.FileDescriptionImpl. +// Stat implements vfs.FileDescriptionImpl.Stat. func (f *fileDescription) Stat(ctx context.Context, opts vfs.StatOptions) (linux.Statx, error) { return f.inode.Stat(ctx, f.vfsfd.Mount().Filesystem(), opts) } -// Release implements vfs.FileDescriptionImpl. +// Release implements vfs.FileDescriptionImpl.Release. func (f *fileDescription) Release(context.Context) { // noop } -// Allocate implements vfs.FileDescriptionImpl. +// Allocate implements vfs.FileDescriptionImpl.Allocate. func (f *fileDescription) Allocate(ctx context.Context, mode, offset, length uint64) error { - if !f.inode.seekable { - return syserror.ESPIPE - } - - // TODO(gvisor.dev/issue/3589): Implement Allocate for non-pipe hostfds. - return syserror.EOPNOTSUPP + return unix.Fallocate(f.inode.hostFD, uint32(mode), int64(offset), int64(length)) } -// PRead implements FileDescriptionImpl. +// PRead implements vfs.FileDescriptionImpl.PRead. func (f *fileDescription) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) { i := f.inode if !i.seekable { @@ -578,7 +571,7 @@ func (f *fileDescription) PRead(ctx context.Context, dst usermem.IOSequence, off return readFromHostFD(ctx, i.hostFD, dst, offset, opts.Flags) } -// Read implements FileDescriptionImpl. +// Read implements vfs.FileDescriptionImpl.Read. func (f *fileDescription) Read(ctx context.Context, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) { i := f.inode if !i.seekable { @@ -615,7 +608,7 @@ func readFromHostFD(ctx context.Context, hostFD int, dst usermem.IOSequence, off return int64(n), err } -// PWrite implements FileDescriptionImpl. +// PWrite implements vfs.FileDescriptionImpl.PWrite. func (f *fileDescription) PWrite(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) { if !f.inode.seekable { return 0, syserror.ESPIPE @@ -624,7 +617,7 @@ func (f *fileDescription) PWrite(ctx context.Context, src usermem.IOSequence, of return f.writeToHostFD(ctx, src, offset, opts.Flags) } -// Write implements FileDescriptionImpl. +// Write implements vfs.FileDescriptionImpl.Write. func (f *fileDescription) Write(ctx context.Context, src usermem.IOSequence, opts vfs.WriteOptions) (int64, error) { i := f.inode if !i.seekable { @@ -672,7 +665,7 @@ func (f *fileDescription) writeToHostFD(ctx context.Context, src usermem.IOSeque return int64(n), err } -// Seek implements FileDescriptionImpl. +// Seek implements vfs.FileDescriptionImpl.Seek. // // Note that we do not support seeking on directories, since we do not even // allow directory fds to be imported at all. @@ -737,13 +730,13 @@ func (f *fileDescription) Seek(_ context.Context, offset int64, whence int32) (i return f.offset, nil } -// Sync implements FileDescriptionImpl. +// Sync implements vfs.FileDescriptionImpl.Sync. func (f *fileDescription) Sync(context.Context) error { // TODO(gvisor.dev/issue/1897): Currently, we always sync everything. return unix.Fsync(f.inode.hostFD) } -// ConfigureMMap implements FileDescriptionImpl. +// ConfigureMMap implements vfs.FileDescriptionImpl.ConfigureMMap. func (f *fileDescription) ConfigureMMap(_ context.Context, opts *memmap.MMapOpts) error { if !f.inode.canMap { return syserror.ENODEV diff --git a/pkg/sentry/fsimpl/host/mmap.go b/pkg/sentry/fsimpl/host/mmap.go index 65d3af38c..b51a17bed 100644 --- a/pkg/sentry/fsimpl/host/mmap.go +++ b/pkg/sentry/fsimpl/host/mmap.go @@ -27,11 +27,13 @@ import ( // cannot implement both kernfs.Inode.IncRef and memmap.File.IncRef. // // inodePlatformFile should only be used if inode.canMap is true. +// +// +stateify savable type inodePlatformFile struct { *inode // fdRefsMu protects fdRefs. - fdRefsMu sync.Mutex + fdRefsMu sync.Mutex `state:"nosave"` // fdRefs counts references on memmap.File offsets. It is used solely for // memory accounting. @@ -41,7 +43,7 @@ type inodePlatformFile struct { fileMapper fsutil.HostFileMapper // fileMapperInitOnce is used to lazily initialize fileMapper. - fileMapperInitOnce sync.Once + fileMapperInitOnce sync.Once `state:"nosave"` // FIXME(gvisor.dev/issue/1663): not yet supported. } // IncRef implements memmap.File.IncRef. diff --git a/pkg/sentry/fsimpl/host/socket_unsafe.go b/pkg/sentry/fsimpl/host/socket_unsafe.go index 35ded24bc..c0bf45f08 100644 --- a/pkg/sentry/fsimpl/host/socket_unsafe.go +++ b/pkg/sentry/fsimpl/host/socket_unsafe.go @@ -63,10 +63,10 @@ func fdReadVec(fd int, bufs [][]byte, control []byte, peek bool, maxlen int64) ( controlTrunc = msg.Flags&syscall.MSG_CTRUNC == syscall.MSG_CTRUNC if n > length { - return length, n, msg.Controllen, controlTrunc, err + return length, n, msg.Controllen, controlTrunc, nil } - return n, n, msg.Controllen, controlTrunc, err + return n, n, msg.Controllen, controlTrunc, nil } // fdWriteVec sends from bufs to fd. diff --git a/pkg/sentry/fsimpl/host/tty.go b/pkg/sentry/fsimpl/host/tty.go index 7a9be4b97..f5c596fec 100644 --- a/pkg/sentry/fsimpl/host/tty.go +++ b/pkg/sentry/fsimpl/host/tty.go @@ -17,6 +17,7 @@ package host import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/arch" fslock "gvisor.dev/gvisor/pkg/sentry/fs/lock" "gvisor.dev/gvisor/pkg/sentry/kernel" @@ -25,11 +26,12 @@ import ( "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/usermem" - "gvisor.dev/gvisor/tools/go_marshal/primitive" ) // TTYFileDescription implements vfs.FileDescriptionImpl for a host file // descriptor that wraps a TTY FD. +// +// +stateify savable type TTYFileDescription struct { fileDescription @@ -76,7 +78,7 @@ func (t *TTYFileDescription) Release(ctx context.Context) { t.fileDescription.Release(ctx) } -// PRead implements vfs.FileDescriptionImpl. +// PRead implements vfs.FileDescriptionImpl.PRead. // // Reading from a TTY is only allowed for foreground process groups. Background // process groups will either get EIO or a SIGTTIN. @@ -94,7 +96,7 @@ func (t *TTYFileDescription) PRead(ctx context.Context, dst usermem.IOSequence, return t.fileDescription.PRead(ctx, dst, offset, opts) } -// Read implements vfs.FileDescriptionImpl. +// Read implements vfs.FileDescriptionImpl.Read. // // Reading from a TTY is only allowed for foreground process groups. Background // process groups will either get EIO or a SIGTTIN. @@ -112,7 +114,7 @@ func (t *TTYFileDescription) Read(ctx context.Context, dst usermem.IOSequence, o return t.fileDescription.Read(ctx, dst, opts) } -// PWrite implements vfs.FileDescriptionImpl. +// PWrite implements vfs.FileDescriptionImpl.PWrite. func (t *TTYFileDescription) PWrite(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) { t.mu.Lock() defer t.mu.Unlock() @@ -127,7 +129,7 @@ func (t *TTYFileDescription) PWrite(ctx context.Context, src usermem.IOSequence, return t.fileDescription.PWrite(ctx, src, offset, opts) } -// Write implements vfs.FileDescriptionImpl. +// Write implements vfs.FileDescriptionImpl.Write. func (t *TTYFileDescription) Write(ctx context.Context, src usermem.IOSequence, opts vfs.WriteOptions) (int64, error) { t.mu.Lock() defer t.mu.Unlock() @@ -142,7 +144,7 @@ func (t *TTYFileDescription) Write(ctx context.Context, src usermem.IOSequence, return t.fileDescription.Write(ctx, src, opts) } -// Ioctl implements vfs.FileDescriptionImpl. +// Ioctl implements vfs.FileDescriptionImpl.Ioctl. func (t *TTYFileDescription) Ioctl(ctx context.Context, io usermem.IO, args arch.SyscallArguments) (uintptr, error) { task := kernel.TaskFromContext(ctx) if task == nil { diff --git a/pkg/sentry/fsimpl/kernfs/BUILD b/pkg/sentry/fsimpl/kernfs/BUILD index 637dca70c..5e91e0536 100644 --- a/pkg/sentry/fsimpl/kernfs/BUILD +++ b/pkg/sentry/fsimpl/kernfs/BUILD @@ -83,6 +83,7 @@ go_library( "slot_list.go", "static_directory_refs.go", "symlink.go", + "synthetic_directory.go", ], visibility = ["//pkg/sentry:internal"], deps = [ diff --git a/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go b/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go index 1ee089620..b929118b1 100644 --- a/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go +++ b/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go @@ -56,9 +56,9 @@ func (f *DynamicBytesFile) Init(creds *auth.Credentials, devMajor, devMinor uint } // Open implements Inode.Open. -func (f *DynamicBytesFile) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { +func (f *DynamicBytesFile) Open(ctx context.Context, rp *vfs.ResolvingPath, d *Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { fd := &DynamicBytesFD{} - if err := fd.Init(rp.Mount(), vfsd, f.data, &f.locks, opts.Flags); err != nil { + if err := fd.Init(rp.Mount(), d, f.data, &f.locks, opts.Flags); err != nil { return nil, err } return &fd.vfsfd, nil @@ -87,12 +87,12 @@ type DynamicBytesFD struct { } // Init initializes a DynamicBytesFD. -func (fd *DynamicBytesFD) Init(m *vfs.Mount, d *vfs.Dentry, data vfs.DynamicBytesSource, locks *vfs.FileLocks, flags uint32) error { +func (fd *DynamicBytesFD) Init(m *vfs.Mount, d *Dentry, data vfs.DynamicBytesSource, locks *vfs.FileLocks, flags uint32) error { fd.LockFD.Init(locks) - if err := fd.vfsfd.Init(fd, flags, m, d, &vfs.FileDescriptionOptions{}); err != nil { + if err := fd.vfsfd.Init(fd, flags, m, d.VFSDentry(), &vfs.FileDescriptionOptions{}); err != nil { return err } - fd.inode = d.Impl().(*Dentry).inode + fd.inode = d.inode fd.SetDataSource(data) return nil } diff --git a/pkg/sentry/fsimpl/kernfs/fd_impl_util.go b/pkg/sentry/fsimpl/kernfs/fd_impl_util.go index 6518ff5cd..0a4cd4057 100644 --- a/pkg/sentry/fsimpl/kernfs/fd_impl_util.go +++ b/pkg/sentry/fsimpl/kernfs/fd_impl_util.go @@ -29,6 +29,8 @@ import ( ) // SeekEndConfig describes the SEEK_END behaviour for FDs. +// +// +stateify savable type SeekEndConfig int // Constants related to SEEK_END behaviour for FDs. @@ -41,6 +43,8 @@ const ( ) // GenericDirectoryFDOptions contains configuration for a GenericDirectoryFD. +// +// +stateify savable type GenericDirectoryFDOptions struct { SeekEnd SeekEndConfig } @@ -56,6 +60,8 @@ type GenericDirectoryFDOptions struct { // Must be initialize with Init before first use. // // Lock ordering: mu => children.mu. +// +// +stateify savable type GenericDirectoryFD struct { vfs.FileDescriptionDefaultImpl vfs.DirectoryFileDescriptionDefaultImpl @@ -68,7 +74,7 @@ type GenericDirectoryFD struct { children *OrderedChildren // mu protects the fields below. - mu sync.Mutex + mu sync.Mutex `state:"nosave"` // off is the current directory offset. Protected by "mu". off int64 @@ -76,12 +82,12 @@ type GenericDirectoryFD struct { // NewGenericDirectoryFD creates a new GenericDirectoryFD and returns its // dentry. -func NewGenericDirectoryFD(m *vfs.Mount, d *vfs.Dentry, children *OrderedChildren, locks *vfs.FileLocks, opts *vfs.OpenOptions, fdOpts GenericDirectoryFDOptions) (*GenericDirectoryFD, error) { +func NewGenericDirectoryFD(m *vfs.Mount, d *Dentry, children *OrderedChildren, locks *vfs.FileLocks, opts *vfs.OpenOptions, fdOpts GenericDirectoryFDOptions) (*GenericDirectoryFD, error) { fd := &GenericDirectoryFD{} if err := fd.Init(children, locks, opts, fdOpts); err != nil { return nil, err } - if err := fd.vfsfd.Init(fd, opts.Flags, m, d, &vfs.FileDescriptionOptions{}); err != nil { + if err := fd.vfsfd.Init(fd, opts.Flags, m, d.VFSDentry(), &vfs.FileDescriptionOptions{}); err != nil { return nil, err } return fd, nil @@ -195,8 +201,7 @@ func (fd *GenericDirectoryFD) IterDirents(ctx context.Context, cb vfs.IterDirent // these. childIdx := fd.off - 2 for it := fd.children.nthLocked(childIdx); it != nil; it = it.Next() { - inode := it.Dentry.Impl().(*Dentry).inode - stat, err := inode.Stat(ctx, fd.filesystem(), opts) + stat, err := it.Dentry.inode.Stat(ctx, fd.filesystem(), opts) if err != nil { return err } diff --git a/pkg/sentry/fsimpl/kernfs/filesystem.go b/pkg/sentry/fsimpl/kernfs/filesystem.go index 0e3011689..5cc1c4281 100644 --- a/pkg/sentry/fsimpl/kernfs/filesystem.go +++ b/pkg/sentry/fsimpl/kernfs/filesystem.go @@ -37,8 +37,7 @@ import ( // * !rp.Done(). // // Postcondition: Caller must call fs.processDeferredDecRefs*. -func (fs *Filesystem) stepExistingLocked(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, mayFollowSymlinks bool) (*vfs.Dentry, error) { - d := vfsd.Impl().(*Dentry) +func (fs *Filesystem) stepExistingLocked(ctx context.Context, rp *vfs.ResolvingPath, d *Dentry, mayFollowSymlinks bool) (*Dentry, error) { if !d.isDir() { return nil, syserror.ENOTDIR } @@ -55,20 +54,20 @@ afterSymlink: // calls d_revalidate(), but walk_component() => handle_dots() does not. if name == "." { rp.Advance() - return vfsd, nil + return d, nil } if name == ".." { - if isRoot, err := rp.CheckRoot(ctx, vfsd); err != nil { + if isRoot, err := rp.CheckRoot(ctx, d.VFSDentry()); err != nil { return nil, err } else if isRoot || d.parent == nil { rp.Advance() - return vfsd, nil + return d, nil } - if err := rp.CheckMount(ctx, &d.parent.vfsd); err != nil { + if err := rp.CheckMount(ctx, d.parent.VFSDentry()); err != nil { return nil, err } rp.Advance() - return &d.parent.vfsd, nil + return d.parent, nil } if len(name) > linux.NAME_MAX { return nil, syserror.ENAMETOOLONG @@ -79,7 +78,7 @@ afterSymlink: if err != nil { return nil, err } - if err := rp.CheckMount(ctx, &next.vfsd); err != nil { + if err := rp.CheckMount(ctx, next.VFSDentry()); err != nil { return nil, err } // Resolve any symlink at current path component. @@ -102,7 +101,7 @@ afterSymlink: goto afterSymlink } rp.Advance() - return &next.vfsd, nil + return next, nil } // revalidateChildLocked must be called after a call to parent.vfsd.Child(name) @@ -122,25 +121,21 @@ func (fs *Filesystem) revalidateChildLocked(ctx context.Context, vfsObj *vfs.Vir if !child.inode.Valid(ctx) { delete(parent.children, name) vfsObj.InvalidateDentry(ctx, &child.vfsd) - fs.deferDecRef(&child.vfsd) // Reference from Lookup. + fs.deferDecRef(child) // Reference from Lookup. child = nil } } if child == nil { - // Dentry isn't cached; it either doesn't exist or failed - // revalidation. Attempt to resolve it via Lookup. - // - // FIXME(gvisor.dev/issue/1193): Inode.Lookup() should return - // *(kernfs.)Dentry, not *vfs.Dentry, since (kernfs.)Filesystem assumes - // that all dentries in the filesystem are (kernfs.)Dentry and performs - // vfs.DentryImpl casts accordingly. - childVFSD, err := parent.inode.Lookup(ctx, name) + // Dentry isn't cached; it either doesn't exist or failed revalidation. + // Attempt to resolve it via Lookup. + c, err := parent.inode.Lookup(ctx, name) if err != nil { return nil, err } - // Reference on childVFSD dropped by a corresponding Valid. - child = childVFSD.Impl().(*Dentry) - parent.insertChildLocked(name, child) + // Reference on c (provided by Lookup) will be dropped when the dentry + // fails validation. + parent.InsertChildLocked(name, c) + child = c } return child, nil } @@ -153,20 +148,19 @@ func (fs *Filesystem) revalidateChildLocked(ctx context.Context, vfsObj *vfs.Vir // Preconditions: Filesystem.mu must be locked for at least reading. // // Postconditions: Caller must call fs.processDeferredDecRefs*. -func (fs *Filesystem) walkExistingLocked(ctx context.Context, rp *vfs.ResolvingPath) (*vfs.Dentry, Inode, error) { - vfsd := rp.Start() +func (fs *Filesystem) walkExistingLocked(ctx context.Context, rp *vfs.ResolvingPath) (*Dentry, error) { + d := rp.Start().Impl().(*Dentry) for !rp.Done() { var err error - vfsd, err = fs.stepExistingLocked(ctx, rp, vfsd, true /* mayFollowSymlinks */) + d, err = fs.stepExistingLocked(ctx, rp, d, true /* mayFollowSymlinks */) if err != nil { - return nil, nil, err + return nil, err } } - d := vfsd.Impl().(*Dentry) if rp.MustBeDir() && !d.isDir() { - return nil, nil, syserror.ENOTDIR + return nil, syserror.ENOTDIR } - return vfsd, d.inode, nil + return d, nil } // walkParentDirLocked resolves all but the last path component of rp to an @@ -181,20 +175,19 @@ func (fs *Filesystem) walkExistingLocked(ctx context.Context, rp *vfs.ResolvingP // * !rp.Done(). // // Postconditions: Caller must call fs.processDeferredDecRefs*. -func (fs *Filesystem) walkParentDirLocked(ctx context.Context, rp *vfs.ResolvingPath) (*vfs.Dentry, Inode, error) { - vfsd := rp.Start() +func (fs *Filesystem) walkParentDirLocked(ctx context.Context, rp *vfs.ResolvingPath) (*Dentry, error) { + d := rp.Start().Impl().(*Dentry) for !rp.Final() { var err error - vfsd, err = fs.stepExistingLocked(ctx, rp, vfsd, true /* mayFollowSymlinks */) + d, err = fs.stepExistingLocked(ctx, rp, d, true /* mayFollowSymlinks */) if err != nil { - return nil, nil, err + return nil, err } } - d := vfsd.Impl().(*Dentry) if !d.isDir() { - return nil, nil, syserror.ENOTDIR + return nil, syserror.ENOTDIR } - return vfsd, d.inode, nil + return d, nil } // checkCreateLocked checks that a file named rp.Component() may be created in @@ -202,10 +195,9 @@ func (fs *Filesystem) walkParentDirLocked(ctx context.Context, rp *vfs.Resolving // // Preconditions: // * Filesystem.mu must be locked for at least reading. -// * parentInode == parentVFSD.Impl().(*Dentry).Inode. // * isDir(parentInode) == true. -func checkCreateLocked(ctx context.Context, rp *vfs.ResolvingPath, parentVFSD *vfs.Dentry, parentInode Inode) (string, error) { - if err := parentInode.CheckPermissions(ctx, rp.Credentials(), vfs.MayWrite|vfs.MayExec); err != nil { +func checkCreateLocked(ctx context.Context, rp *vfs.ResolvingPath, parent *Dentry) (string, error) { + if err := parent.inode.CheckPermissions(ctx, rp.Credentials(), vfs.MayWrite|vfs.MayExec); err != nil { return "", err } pc := rp.Component() @@ -215,11 +207,10 @@ func checkCreateLocked(ctx context.Context, rp *vfs.ResolvingPath, parentVFSD *v if len(pc) > linux.NAME_MAX { return "", syserror.ENAMETOOLONG } - // FIXME(gvisor.dev/issue/1193): Data race due to not holding dirMu. - if _, ok := parentVFSD.Impl().(*Dentry).children[pc]; ok { + if _, ok := parent.children[pc]; ok { return "", syserror.EEXIST } - if parentVFSD.IsDead() { + if parent.VFSDentry().IsDead() { return "", syserror.ENOENT } return pc, nil @@ -228,8 +219,8 @@ func checkCreateLocked(ctx context.Context, rp *vfs.ResolvingPath, parentVFSD *v // checkDeleteLocked checks that the file represented by vfsd may be deleted. // // Preconditions: Filesystem.mu must be locked for at least reading. -func checkDeleteLocked(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry) error { - parent := vfsd.Impl().(*Dentry).parent +func checkDeleteLocked(ctx context.Context, rp *vfs.ResolvingPath, d *Dentry) error { + parent := d.parent if parent == nil { return syserror.EBUSY } @@ -258,11 +249,11 @@ func (fs *Filesystem) AccessAt(ctx context.Context, rp *vfs.ResolvingPath, creds defer fs.processDeferredDecRefs(ctx) defer fs.mu.RUnlock() - _, inode, err := fs.walkExistingLocked(ctx, rp) + d, err := fs.walkExistingLocked(ctx, rp) if err != nil { return err } - return inode.CheckPermissions(ctx, creds, ats) + return d.inode.CheckPermissions(ctx, creds, ats) } // GetDentryAt implements vfs.FilesystemImpl.GetDentryAt. @@ -270,20 +261,20 @@ func (fs *Filesystem) GetDentryAt(ctx context.Context, rp *vfs.ResolvingPath, op fs.mu.RLock() defer fs.processDeferredDecRefs(ctx) defer fs.mu.RUnlock() - vfsd, inode, err := fs.walkExistingLocked(ctx, rp) + d, err := fs.walkExistingLocked(ctx, rp) if err != nil { return nil, err } if opts.CheckSearchable { - d := vfsd.Impl().(*Dentry) if !d.isDir() { return nil, syserror.ENOTDIR } - if err := inode.CheckPermissions(ctx, rp.Credentials(), vfs.MayExec); err != nil { + if err := d.inode.CheckPermissions(ctx, rp.Credentials(), vfs.MayExec); err != nil { return nil, err } } + vfsd := d.VFSDentry() vfsd.IncRef() // Ownership transferred to caller. return vfsd, nil } @@ -293,12 +284,12 @@ func (fs *Filesystem) GetParentDentryAt(ctx context.Context, rp *vfs.ResolvingPa fs.mu.RLock() defer fs.processDeferredDecRefs(ctx) defer fs.mu.RUnlock() - vfsd, _, err := fs.walkParentDirLocked(ctx, rp) + d, err := fs.walkParentDirLocked(ctx, rp) if err != nil { return nil, err } - vfsd.IncRef() // Ownership transferred to caller. - return vfsd, nil + d.IncRef() // Ownership transferred to caller. + return d.VFSDentry(), nil } // LinkAt implements vfs.FilesystemImpl.LinkAt. @@ -308,12 +299,15 @@ func (fs *Filesystem) LinkAt(ctx context.Context, rp *vfs.ResolvingPath, vd vfs. } fs.mu.Lock() defer fs.mu.Unlock() - parentVFSD, parentInode, err := fs.walkParentDirLocked(ctx, rp) + parent, err := fs.walkParentDirLocked(ctx, rp) fs.processDeferredDecRefsLocked(ctx) if err != nil { return err } - pc, err := checkCreateLocked(ctx, rp, parentVFSD, parentInode) + + parent.dirMu.Lock() + defer parent.dirMu.Unlock() + pc, err := checkCreateLocked(ctx, rp, parent) if err != nil { return err } @@ -330,11 +324,11 @@ func (fs *Filesystem) LinkAt(ctx context.Context, rp *vfs.ResolvingPath, vd vfs. return syserror.EPERM } - childVFSD, err := parentInode.NewLink(ctx, pc, d.inode) + child, err := parent.inode.NewLink(ctx, pc, d.inode) if err != nil { return err } - parentVFSD.Impl().(*Dentry).InsertChild(pc, childVFSD.Impl().(*Dentry)) + parent.InsertChildLocked(pc, child) return nil } @@ -345,12 +339,15 @@ func (fs *Filesystem) MkdirAt(ctx context.Context, rp *vfs.ResolvingPath, opts v } fs.mu.Lock() defer fs.mu.Unlock() - parentVFSD, parentInode, err := fs.walkParentDirLocked(ctx, rp) + parent, err := fs.walkParentDirLocked(ctx, rp) fs.processDeferredDecRefsLocked(ctx) if err != nil { return err } - pc, err := checkCreateLocked(ctx, rp, parentVFSD, parentInode) + + parent.dirMu.Lock() + defer parent.dirMu.Unlock() + pc, err := checkCreateLocked(ctx, rp, parent) if err != nil { return err } @@ -358,11 +355,14 @@ func (fs *Filesystem) MkdirAt(ctx context.Context, rp *vfs.ResolvingPath, opts v return err } defer rp.Mount().EndWrite() - childVFSD, err := parentInode.NewDir(ctx, pc, opts) + child, err := parent.inode.NewDir(ctx, pc, opts) if err != nil { - return err + if !opts.ForSyntheticMountpoint || err == syserror.EEXIST { + return err + } + child = newSyntheticDirectory(rp.Credentials(), opts.Mode) } - parentVFSD.Impl().(*Dentry).InsertChild(pc, childVFSD.Impl().(*Dentry)) + parent.InsertChildLocked(pc, child) return nil } @@ -373,12 +373,15 @@ func (fs *Filesystem) MknodAt(ctx context.Context, rp *vfs.ResolvingPath, opts v } fs.mu.Lock() defer fs.mu.Unlock() - parentVFSD, parentInode, err := fs.walkParentDirLocked(ctx, rp) + parent, err := fs.walkParentDirLocked(ctx, rp) fs.processDeferredDecRefsLocked(ctx) if err != nil { return err } - pc, err := checkCreateLocked(ctx, rp, parentVFSD, parentInode) + + parent.dirMu.Lock() + defer parent.dirMu.Unlock() + pc, err := checkCreateLocked(ctx, rp, parent) if err != nil { return err } @@ -386,11 +389,11 @@ func (fs *Filesystem) MknodAt(ctx context.Context, rp *vfs.ResolvingPath, opts v return err } defer rp.Mount().EndWrite() - newVFSD, err := parentInode.NewNode(ctx, pc, opts) + newD, err := parent.inode.NewNode(ctx, pc, opts) if err != nil { return err } - parentVFSD.Impl().(*Dentry).InsertChild(pc, newVFSD.Impl().(*Dentry)) + parent.InsertChildLocked(pc, newD) return nil } @@ -406,28 +409,27 @@ func (fs *Filesystem) OpenAt(ctx context.Context, rp *vfs.ResolvingPath, opts vf // Do not create new file. if opts.Flags&linux.O_CREAT == 0 { fs.mu.RLock() - vfsd, inode, err := fs.walkExistingLocked(ctx, rp) + d, err := fs.walkExistingLocked(ctx, rp) if err != nil { fs.mu.RUnlock() fs.processDeferredDecRefs(ctx) return nil, err } - if err := inode.CheckPermissions(ctx, rp.Credentials(), ats); err != nil { + if err := d.inode.CheckPermissions(ctx, rp.Credentials(), ats); err != nil { fs.mu.RUnlock() fs.processDeferredDecRefs(ctx) return nil, err } - inode.IncRef() - defer inode.DecRef(ctx) + d.inode.IncRef() + defer d.inode.DecRef(ctx) fs.mu.RUnlock() fs.processDeferredDecRefs(ctx) - return inode.Open(ctx, rp, vfsd, opts) + return d.inode.Open(ctx, rp, d, opts) } // May create new file. mustCreate := opts.Flags&linux.O_EXCL != 0 - vfsd := rp.Start() - inode := vfsd.Impl().(*Dentry).inode + d := rp.Start().Impl().(*Dentry) fs.mu.Lock() unlocked := false unlock := func() { @@ -444,22 +446,22 @@ func (fs *Filesystem) OpenAt(ctx context.Context, rp *vfs.ResolvingPath, opts vf if mustCreate { return nil, syserror.EEXIST } - if err := inode.CheckPermissions(ctx, rp.Credentials(), ats); err != nil { + if err := d.inode.CheckPermissions(ctx, rp.Credentials(), ats); err != nil { return nil, err } - inode.IncRef() - defer inode.DecRef(ctx) + d.inode.IncRef() + defer d.inode.DecRef(ctx) unlock() - return inode.Open(ctx, rp, vfsd, opts) + return d.inode.Open(ctx, rp, d, opts) } afterTrailingSymlink: - parentVFSD, parentInode, err := fs.walkParentDirLocked(ctx, rp) + parent, err := fs.walkParentDirLocked(ctx, rp) fs.processDeferredDecRefsLocked(ctx) if err != nil { return nil, err } // Check for search permission in the parent directory. - if err := parentInode.CheckPermissions(ctx, rp.Credentials(), vfs.MayExec); err != nil { + if err := parent.inode.CheckPermissions(ctx, rp.Credentials(), vfs.MayExec); err != nil { return nil, err } // Reject attempts to open directories with O_CREAT. @@ -474,10 +476,10 @@ afterTrailingSymlink: return nil, syserror.ENAMETOOLONG } // Determine whether or not we need to create a file. - childVFSD, err := fs.stepExistingLocked(ctx, rp, parentVFSD, false /* mayFollowSymlinks */) + child, err := fs.stepExistingLocked(ctx, rp, parent, false /* mayFollowSymlinks */) if err == syserror.ENOENT { // Already checked for searchability above; now check for writability. - if err := parentInode.CheckPermissions(ctx, rp.Credentials(), vfs.MayWrite); err != nil { + if err := parent.inode.CheckPermissions(ctx, rp.Credentials(), vfs.MayWrite); err != nil { return nil, err } if err := rp.Mount().CheckBeginWrite(); err != nil { @@ -485,16 +487,18 @@ afterTrailingSymlink: } defer rp.Mount().EndWrite() // Create and open the child. - childVFSD, err = parentInode.NewFile(ctx, pc, opts) + child, err := parent.inode.NewFile(ctx, pc, opts) if err != nil { return nil, err } - child := childVFSD.Impl().(*Dentry) - parentVFSD.Impl().(*Dentry).InsertChild(pc, child) + // FIXME(gvisor.dev/issue/1193): Race between checking existence with + // fs.stepExistingLocked and parent.InsertChild. If possible, we should hold + // dirMu from one to the other. + parent.InsertChild(pc, child) child.inode.IncRef() defer child.inode.DecRef(ctx) unlock() - return child.inode.Open(ctx, rp, childVFSD, opts) + return child.inode.Open(ctx, rp, child, opts) } if err != nil { return nil, err @@ -503,7 +507,6 @@ afterTrailingSymlink: if mustCreate { return nil, syserror.EEXIST } - child := childVFSD.Impl().(*Dentry) if rp.ShouldFollowSymlink() && child.isSymlink() { targetVD, targetPathname, err := child.inode.Getlink(ctx, rp.Mount()) if err != nil { @@ -530,22 +533,22 @@ afterTrailingSymlink: child.inode.IncRef() defer child.inode.DecRef(ctx) unlock() - return child.inode.Open(ctx, rp, &child.vfsd, opts) + return child.inode.Open(ctx, rp, child, opts) } // ReadlinkAt implements vfs.FilesystemImpl.ReadlinkAt. func (fs *Filesystem) ReadlinkAt(ctx context.Context, rp *vfs.ResolvingPath) (string, error) { fs.mu.RLock() - d, inode, err := fs.walkExistingLocked(ctx, rp) + d, err := fs.walkExistingLocked(ctx, rp) fs.mu.RUnlock() fs.processDeferredDecRefs(ctx) if err != nil { return "", err } - if !d.Impl().(*Dentry).isSymlink() { + if !d.isSymlink() { return "", syserror.EINVAL } - return inode.Readlink(ctx) + return d.inode.Readlink(ctx, rp.Mount()) } // RenameAt implements vfs.FilesystemImpl.RenameAt. @@ -562,11 +565,10 @@ func (fs *Filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa // Resolve the destination directory first to verify that it's on this // Mount. - dstDirVFSD, dstDirInode, err := fs.walkParentDirLocked(ctx, rp) + dstDir, err := fs.walkParentDirLocked(ctx, rp) if err != nil { return err } - dstDir := dstDirVFSD.Impl().(*Dentry) mnt := rp.Mount() if mnt != oldParentVD.Mount() { return syserror.EXDEV @@ -584,16 +586,15 @@ func (fs *Filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa if err != nil { return err } - srcVFSD := &src.vfsd // Can we remove the src dentry? - if err := checkDeleteLocked(ctx, rp, srcVFSD); err != nil { + if err := checkDeleteLocked(ctx, rp, src); err != nil { return err } // Can we create the dst dentry? var dst *Dentry - pc, err := checkCreateLocked(ctx, rp, dstDirVFSD, dstDirInode) + pc, err := checkCreateLocked(ctx, rp, dstDir) switch err { case nil: // Ok, continue with rename as replacement. @@ -604,14 +605,14 @@ func (fs *Filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa } dst = dstDir.children[pc] if dst == nil { - panic(fmt.Sprintf("Child %q for parent Dentry %+v disappeared inside atomic section?", pc, dstDirVFSD)) + panic(fmt.Sprintf("Child %q for parent Dentry %+v disappeared inside atomic section?", pc, dstDir)) } default: return err } var dstVFSD *vfs.Dentry if dst != nil { - dstVFSD = &dst.vfsd + dstVFSD = dst.VFSDentry() } mntns := vfs.MountNamespaceFromContext(ctx) @@ -627,17 +628,18 @@ func (fs *Filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa defer dstDir.dirMu.Unlock() } + srcVFSD := src.VFSDentry() if err := virtfs.PrepareRenameDentry(mntns, srcVFSD, dstVFSD); err != nil { return err } - replaced, err := srcDir.inode.Rename(ctx, src.name, pc, srcVFSD, dstDirVFSD) + replaced, err := srcDir.inode.Rename(ctx, src.name, pc, src, dstDir) if err != nil { virtfs.AbortRenameDentry(srcVFSD, dstVFSD) return err } delete(srcDir.children, src.name) if srcDir != dstDir { - fs.deferDecRef(srcDirVFSD) + fs.deferDecRef(srcDir) dstDir.IncRef() } src.parent = dstDir @@ -646,7 +648,11 @@ func (fs *Filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa dstDir.children = make(map[string]*Dentry) } dstDir.children[pc] = src - virtfs.CommitRenameReplaceDentry(ctx, srcVFSD, replaced) + var replaceVFSD *vfs.Dentry + if replaced != nil { + replaceVFSD = replaced.VFSDentry() + } + virtfs.CommitRenameReplaceDentry(ctx, srcVFSD, replaceVFSD) return nil } @@ -654,7 +660,8 @@ func (fs *Filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa func (fs *Filesystem) RmdirAt(ctx context.Context, rp *vfs.ResolvingPath) error { fs.mu.Lock() defer fs.mu.Unlock() - vfsd, inode, err := fs.walkExistingLocked(ctx, rp) + + d, err := fs.walkExistingLocked(ctx, rp) fs.processDeferredDecRefsLocked(ctx) if err != nil { return err @@ -663,14 +670,13 @@ func (fs *Filesystem) RmdirAt(ctx context.Context, rp *vfs.ResolvingPath) error return err } defer rp.Mount().EndWrite() - if err := checkDeleteLocked(ctx, rp, vfsd); err != nil { + if err := checkDeleteLocked(ctx, rp, d); err != nil { return err } - d := vfsd.Impl().(*Dentry) if !d.isDir() { return syserror.ENOTDIR } - if inode.HasChildren() { + if d.inode.HasChildren() { return syserror.ENOTEMPTY } virtfs := rp.VirtualFilesystem() @@ -680,10 +686,12 @@ func (fs *Filesystem) RmdirAt(ctx context.Context, rp *vfs.ResolvingPath) error mntns := vfs.MountNamespaceFromContext(ctx) defer mntns.DecRef(ctx) + vfsd := d.VFSDentry() if err := virtfs.PrepareDeleteDentry(mntns, vfsd); err != nil { return err } - if err := parentDentry.inode.RmDir(ctx, rp.Component(), vfsd); err != nil { + + if err := parentDentry.inode.RmDir(ctx, d.name, d); err != nil { virtfs.AbortDeleteDentry(vfsd) return err } @@ -694,7 +702,7 @@ func (fs *Filesystem) RmdirAt(ctx context.Context, rp *vfs.ResolvingPath) error // SetStatAt implements vfs.FilesystemImpl.SetStatAt. func (fs *Filesystem) SetStatAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.SetStatOptions) error { fs.mu.RLock() - _, inode, err := fs.walkExistingLocked(ctx, rp) + d, err := fs.walkExistingLocked(ctx, rp) fs.mu.RUnlock() fs.processDeferredDecRefs(ctx) if err != nil { @@ -703,31 +711,31 @@ func (fs *Filesystem) SetStatAt(ctx context.Context, rp *vfs.ResolvingPath, opts if opts.Stat.Mask == 0 { return nil } - return inode.SetStat(ctx, fs.VFSFilesystem(), rp.Credentials(), opts) + return d.inode.SetStat(ctx, fs.VFSFilesystem(), rp.Credentials(), opts) } // StatAt implements vfs.FilesystemImpl.StatAt. func (fs *Filesystem) StatAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.StatOptions) (linux.Statx, error) { fs.mu.RLock() - _, inode, err := fs.walkExistingLocked(ctx, rp) + d, err := fs.walkExistingLocked(ctx, rp) fs.mu.RUnlock() fs.processDeferredDecRefs(ctx) if err != nil { return linux.Statx{}, err } - return inode.Stat(ctx, fs.VFSFilesystem(), opts) + return d.inode.Stat(ctx, fs.VFSFilesystem(), opts) } // StatFSAt implements vfs.FilesystemImpl.StatFSAt. func (fs *Filesystem) StatFSAt(ctx context.Context, rp *vfs.ResolvingPath) (linux.Statfs, error) { fs.mu.RLock() - _, inode, err := fs.walkExistingLocked(ctx, rp) + d, err := fs.walkExistingLocked(ctx, rp) fs.mu.RUnlock() fs.processDeferredDecRefs(ctx) if err != nil { return linux.Statfs{}, err } - return inode.StatFS(ctx, fs.VFSFilesystem()) + return d.inode.StatFS(ctx, fs.VFSFilesystem()) } // SymlinkAt implements vfs.FilesystemImpl.SymlinkAt. @@ -737,12 +745,15 @@ func (fs *Filesystem) SymlinkAt(ctx context.Context, rp *vfs.ResolvingPath, targ } fs.mu.Lock() defer fs.mu.Unlock() - parentVFSD, parentInode, err := fs.walkParentDirLocked(ctx, rp) + parent, err := fs.walkParentDirLocked(ctx, rp) fs.processDeferredDecRefsLocked(ctx) if err != nil { return err } - pc, err := checkCreateLocked(ctx, rp, parentVFSD, parentInode) + parent.dirMu.Lock() + defer parent.dirMu.Unlock() + + pc, err := checkCreateLocked(ctx, rp, parent) if err != nil { return err } @@ -750,11 +761,11 @@ func (fs *Filesystem) SymlinkAt(ctx context.Context, rp *vfs.ResolvingPath, targ return err } defer rp.Mount().EndWrite() - childVFSD, err := parentInode.NewSymlink(ctx, pc, target) + child, err := parent.inode.NewSymlink(ctx, pc, target) if err != nil { return err } - parentVFSD.Impl().(*Dentry).InsertChild(pc, childVFSD.Impl().(*Dentry)) + parent.InsertChildLocked(pc, child) return nil } @@ -762,7 +773,8 @@ func (fs *Filesystem) SymlinkAt(ctx context.Context, rp *vfs.ResolvingPath, targ func (fs *Filesystem) UnlinkAt(ctx context.Context, rp *vfs.ResolvingPath) error { fs.mu.Lock() defer fs.mu.Unlock() - vfsd, _, err := fs.walkExistingLocked(ctx, rp) + + d, err := fs.walkExistingLocked(ctx, rp) fs.processDeferredDecRefsLocked(ctx) if err != nil { return err @@ -771,10 +783,9 @@ func (fs *Filesystem) UnlinkAt(ctx context.Context, rp *vfs.ResolvingPath) error return err } defer rp.Mount().EndWrite() - if err := checkDeleteLocked(ctx, rp, vfsd); err != nil { + if err := checkDeleteLocked(ctx, rp, d); err != nil { return err } - d := vfsd.Impl().(*Dentry) if d.isDir() { return syserror.EISDIR } @@ -784,10 +795,11 @@ func (fs *Filesystem) UnlinkAt(ctx context.Context, rp *vfs.ResolvingPath) error defer parentDentry.dirMu.Unlock() mntns := vfs.MountNamespaceFromContext(ctx) defer mntns.DecRef(ctx) + vfsd := d.VFSDentry() if err := virtfs.PrepareDeleteDentry(mntns, vfsd); err != nil { return err } - if err := parentDentry.inode.Unlink(ctx, rp.Component(), vfsd); err != nil { + if err := parentDentry.inode.Unlink(ctx, d.name, d); err != nil { virtfs.AbortDeleteDentry(vfsd) return err } @@ -795,25 +807,25 @@ func (fs *Filesystem) UnlinkAt(ctx context.Context, rp *vfs.ResolvingPath) error return nil } -// BoundEndpointAt implements FilesystemImpl.BoundEndpointAt. +// BoundEndpointAt implements vfs.FilesystemImpl.BoundEndpointAt. func (fs *Filesystem) BoundEndpointAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.BoundEndpointOptions) (transport.BoundEndpoint, error) { fs.mu.RLock() - _, inode, err := fs.walkExistingLocked(ctx, rp) + d, err := fs.walkExistingLocked(ctx, rp) fs.mu.RUnlock() fs.processDeferredDecRefs(ctx) if err != nil { return nil, err } - if err := inode.CheckPermissions(ctx, rp.Credentials(), vfs.MayWrite); err != nil { + if err := d.inode.CheckPermissions(ctx, rp.Credentials(), vfs.MayWrite); err != nil { return nil, err } return nil, syserror.ECONNREFUSED } -// ListxattrAt implements vfs.FilesystemImpl.ListxattrAt. -func (fs *Filesystem) ListxattrAt(ctx context.Context, rp *vfs.ResolvingPath, size uint64) ([]string, error) { +// ListXattrAt implements vfs.FilesystemImpl.ListXattrAt. +func (fs *Filesystem) ListXattrAt(ctx context.Context, rp *vfs.ResolvingPath, size uint64) ([]string, error) { fs.mu.RLock() - _, _, err := fs.walkExistingLocked(ctx, rp) + _, err := fs.walkExistingLocked(ctx, rp) fs.mu.RUnlock() fs.processDeferredDecRefs(ctx) if err != nil { @@ -823,10 +835,10 @@ func (fs *Filesystem) ListxattrAt(ctx context.Context, rp *vfs.ResolvingPath, si return nil, syserror.ENOTSUP } -// GetxattrAt implements vfs.FilesystemImpl.GetxattrAt. -func (fs *Filesystem) GetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.GetxattrOptions) (string, error) { +// GetXattrAt implements vfs.FilesystemImpl.GetXattrAt. +func (fs *Filesystem) GetXattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.GetXattrOptions) (string, error) { fs.mu.RLock() - _, _, err := fs.walkExistingLocked(ctx, rp) + _, err := fs.walkExistingLocked(ctx, rp) fs.mu.RUnlock() fs.processDeferredDecRefs(ctx) if err != nil { @@ -836,10 +848,10 @@ func (fs *Filesystem) GetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opt return "", syserror.ENOTSUP } -// SetxattrAt implements vfs.FilesystemImpl.SetxattrAt. -func (fs *Filesystem) SetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.SetxattrOptions) error { +// SetXattrAt implements vfs.FilesystemImpl.SetXattrAt. +func (fs *Filesystem) SetXattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.SetXattrOptions) error { fs.mu.RLock() - _, _, err := fs.walkExistingLocked(ctx, rp) + _, err := fs.walkExistingLocked(ctx, rp) fs.mu.RUnlock() fs.processDeferredDecRefs(ctx) if err != nil { @@ -849,10 +861,10 @@ func (fs *Filesystem) SetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opt return syserror.ENOTSUP } -// RemovexattrAt implements vfs.FilesystemImpl.RemovexattrAt. -func (fs *Filesystem) RemovexattrAt(ctx context.Context, rp *vfs.ResolvingPath, name string) error { +// RemoveXattrAt implements vfs.FilesystemImpl.RemoveXattrAt. +func (fs *Filesystem) RemoveXattrAt(ctx context.Context, rp *vfs.ResolvingPath, name string) error { fs.mu.RLock() - _, _, err := fs.walkExistingLocked(ctx, rp) + _, err := fs.walkExistingLocked(ctx, rp) fs.mu.RUnlock() fs.processDeferredDecRefs(ctx) if err != nil { diff --git a/pkg/sentry/fsimpl/kernfs/inode_impl_util.go b/pkg/sentry/fsimpl/kernfs/inode_impl_util.go index c0b863ba4..49210e748 100644 --- a/pkg/sentry/fsimpl/kernfs/inode_impl_util.go +++ b/pkg/sentry/fsimpl/kernfs/inode_impl_util.go @@ -31,6 +31,8 @@ import ( // count for inodes, performing no extra actions when references are obtained or // released. This is suitable for simple file inodes that don't reference any // resources. +// +// +stateify savable type InodeNoopRefCount struct { } @@ -50,30 +52,32 @@ func (InodeNoopRefCount) TryIncRef() bool { // InodeDirectoryNoNewChildren partially implements the Inode interface. // InodeDirectoryNoNewChildren represents a directory inode which does not // support creation of new children. +// +// +stateify savable type InodeDirectoryNoNewChildren struct{} // NewFile implements Inode.NewFile. -func (InodeDirectoryNoNewChildren) NewFile(context.Context, string, vfs.OpenOptions) (*vfs.Dentry, error) { +func (InodeDirectoryNoNewChildren) NewFile(context.Context, string, vfs.OpenOptions) (*Dentry, error) { return nil, syserror.EPERM } // NewDir implements Inode.NewDir. -func (InodeDirectoryNoNewChildren) NewDir(context.Context, string, vfs.MkdirOptions) (*vfs.Dentry, error) { +func (InodeDirectoryNoNewChildren) NewDir(context.Context, string, vfs.MkdirOptions) (*Dentry, error) { return nil, syserror.EPERM } // NewLink implements Inode.NewLink. -func (InodeDirectoryNoNewChildren) NewLink(context.Context, string, Inode) (*vfs.Dentry, error) { +func (InodeDirectoryNoNewChildren) NewLink(context.Context, string, Inode) (*Dentry, error) { return nil, syserror.EPERM } // NewSymlink implements Inode.NewSymlink. -func (InodeDirectoryNoNewChildren) NewSymlink(context.Context, string, string) (*vfs.Dentry, error) { +func (InodeDirectoryNoNewChildren) NewSymlink(context.Context, string, string) (*Dentry, error) { return nil, syserror.EPERM } // NewNode implements Inode.NewNode. -func (InodeDirectoryNoNewChildren) NewNode(context.Context, string, vfs.MknodOptions) (*vfs.Dentry, error) { +func (InodeDirectoryNoNewChildren) NewNode(context.Context, string, vfs.MknodOptions) (*Dentry, error) { return nil, syserror.EPERM } @@ -81,6 +85,8 @@ func (InodeDirectoryNoNewChildren) NewNode(context.Context, string, vfs.MknodOpt // inodeDirectory and inodeDynamicDirectory sub interfaces. Inodes that do not // represent directories can embed this to provide no-op implementations for // directory-related functions. +// +// +stateify savable type InodeNotDirectory struct { } @@ -90,47 +96,47 @@ func (InodeNotDirectory) HasChildren() bool { } // NewFile implements Inode.NewFile. -func (InodeNotDirectory) NewFile(context.Context, string, vfs.OpenOptions) (*vfs.Dentry, error) { +func (InodeNotDirectory) NewFile(context.Context, string, vfs.OpenOptions) (*Dentry, error) { panic("NewFile called on non-directory inode") } // NewDir implements Inode.NewDir. -func (InodeNotDirectory) NewDir(context.Context, string, vfs.MkdirOptions) (*vfs.Dentry, error) { +func (InodeNotDirectory) NewDir(context.Context, string, vfs.MkdirOptions) (*Dentry, error) { panic("NewDir called on non-directory inode") } // NewLink implements Inode.NewLinkink. -func (InodeNotDirectory) NewLink(context.Context, string, Inode) (*vfs.Dentry, error) { +func (InodeNotDirectory) NewLink(context.Context, string, Inode) (*Dentry, error) { panic("NewLink called on non-directory inode") } // NewSymlink implements Inode.NewSymlink. -func (InodeNotDirectory) NewSymlink(context.Context, string, string) (*vfs.Dentry, error) { +func (InodeNotDirectory) NewSymlink(context.Context, string, string) (*Dentry, error) { panic("NewSymlink called on non-directory inode") } // NewNode implements Inode.NewNode. -func (InodeNotDirectory) NewNode(context.Context, string, vfs.MknodOptions) (*vfs.Dentry, error) { +func (InodeNotDirectory) NewNode(context.Context, string, vfs.MknodOptions) (*Dentry, error) { panic("NewNode called on non-directory inode") } // Unlink implements Inode.Unlink. -func (InodeNotDirectory) Unlink(context.Context, string, *vfs.Dentry) error { +func (InodeNotDirectory) Unlink(context.Context, string, *Dentry) error { panic("Unlink called on non-directory inode") } // RmDir implements Inode.RmDir. -func (InodeNotDirectory) RmDir(context.Context, string, *vfs.Dentry) error { +func (InodeNotDirectory) RmDir(context.Context, string, *Dentry) error { panic("RmDir called on non-directory inode") } // Rename implements Inode.Rename. -func (InodeNotDirectory) Rename(context.Context, string, string, *vfs.Dentry, *vfs.Dentry) (*vfs.Dentry, error) { +func (InodeNotDirectory) Rename(context.Context, string, string, *Dentry, *Dentry) (*Dentry, error) { panic("Rename called on non-directory inode") } // Lookup implements Inode.Lookup. -func (InodeNotDirectory) Lookup(ctx context.Context, name string) (*vfs.Dentry, error) { +func (InodeNotDirectory) Lookup(ctx context.Context, name string) (*Dentry, error) { panic("Lookup called on non-directory inode") } @@ -149,10 +155,12 @@ func (InodeNotDirectory) Valid(context.Context) bool { // dymanic entries (i.e. entries that are not "hashed" into the // vfs.Dentry.children) can embed this to provide no-op implementations for // functions related to dynamic entries. +// +// +stateify savable type InodeNoDynamicLookup struct{} // Lookup implements Inode.Lookup. -func (InodeNoDynamicLookup) Lookup(ctx context.Context, name string) (*vfs.Dentry, error) { +func (InodeNoDynamicLookup) Lookup(ctx context.Context, name string) (*Dentry, error) { return nil, syserror.ENOENT } @@ -169,10 +177,12 @@ func (InodeNoDynamicLookup) Valid(ctx context.Context) bool { // InodeNotSymlink partially implements the Inode interface, specifically the // inodeSymlink sub interface. All inodes that are not symlinks may embed this // to return the appropriate errors from symlink-related functions. +// +// +stateify savable type InodeNotSymlink struct{} // Readlink implements Inode.Readlink. -func (InodeNotSymlink) Readlink(context.Context) (string, error) { +func (InodeNotSymlink) Readlink(context.Context, *vfs.Mount) (string, error) { return "", syserror.EINVAL } @@ -186,6 +196,8 @@ func (InodeNotSymlink) Getlink(context.Context, *vfs.Mount) (vfs.VirtualDentry, // inode attributes. // // Must be initialized by Init prior to first use. +// +// +stateify savable type InodeAttrs struct { devMajor uint32 devMinor uint32 @@ -256,12 +268,29 @@ func (a *InodeAttrs) Stat(context.Context, *vfs.Filesystem, vfs.StatOptions) (li // SetStat implements Inode.SetStat. func (a *InodeAttrs) SetStat(ctx context.Context, fs *vfs.Filesystem, creds *auth.Credentials, opts vfs.SetStatOptions) error { + return a.SetInodeStat(ctx, fs, creds, opts) +} + +// SetInodeStat sets the corresponding attributes from opts to InodeAttrs. +// This function can be used by other kernfs-based filesystem implementation to +// sets the unexported attributes into kernfs.InodeAttrs. +func (a *InodeAttrs) SetInodeStat(ctx context.Context, fs *vfs.Filesystem, creds *auth.Credentials, opts vfs.SetStatOptions) error { if opts.Stat.Mask == 0 { return nil } - if opts.Stat.Mask&^(linux.STATX_MODE|linux.STATX_UID|linux.STATX_GID) != 0 { + + // Note that not all fields are modifiable. For example, the file type and + // inode numbers are immutable after node creation. Setting the size is often + // allowed by kernfs files but does not do anything. If some other behavior is + // needed, the embedder should consider extending SetStat. + // + // TODO(gvisor.dev/issue/1193): Implement other stat fields like timestamps. + if opts.Stat.Mask&^(linux.STATX_MODE|linux.STATX_UID|linux.STATX_GID|linux.STATX_SIZE) != 0 { return syserror.EPERM } + if opts.Stat.Mask&linux.STATX_SIZE != 0 && a.Mode().IsDir() { + return syserror.EISDIR + } if err := vfs.CheckSetStat(ctx, creds, &opts, a.Mode(), auth.KUID(atomic.LoadUint32(&a.uid)), auth.KGID(atomic.LoadUint32(&a.gid))); err != nil { return err } @@ -284,13 +313,6 @@ func (a *InodeAttrs) SetStat(ctx context.Context, fs *vfs.Filesystem, creds *aut atomic.StoreUint32(&a.gid, stat.GID) } - // Note that not all fields are modifiable. For example, the file type and - // inode numbers are immutable after node creation. - - // TODO(gvisor.dev/issue/1193): Implement other stat fields like timestamps. - // Also, STATX_SIZE will need some special handling, because read-only static - // files should return EIO for truncate operations. - return nil } @@ -320,13 +342,16 @@ func (a *InodeAttrs) DecLinks() { } } +// +stateify savable type slot struct { Name string - Dentry *vfs.Dentry + Dentry *Dentry slotEntry } // OrderedChildrenOptions contains initialization options for OrderedChildren. +// +// +stateify savable type OrderedChildrenOptions struct { // Writable indicates whether vfs.FilesystemImpl methods implemented by // OrderedChildren may modify the tracked children. This applies to @@ -342,12 +367,14 @@ type OrderedChildrenOptions struct { // directories. // // Must be initialize with Init before first use. +// +// +stateify savable type OrderedChildren struct { // Can children be modified by user syscalls? It set to false, interface // methods that would modify the children return EPERM. Immutable. writable bool - mu sync.RWMutex + mu sync.RWMutex `state:"nosave"` order slotList set map[string]*slot } @@ -380,7 +407,7 @@ func (o *OrderedChildren) Populate(d *Dentry, children map[string]*Dentry) uint3 if child.isDir() { links++ } - if err := o.Insert(name, child.VFSDentry()); err != nil { + if err := o.Insert(name, child); err != nil { panic(fmt.Sprintf("Collision when attempting to insert child %q (%+v) into %+v", name, child, d)) } d.InsertChild(name, child) @@ -397,7 +424,7 @@ func (o *OrderedChildren) HasChildren() bool { // Insert inserts child into o. This ignores the writability of o, as this is // not part of the vfs.FilesystemImpl interface, and is a lower-level operation. -func (o *OrderedChildren) Insert(name string, child *vfs.Dentry) error { +func (o *OrderedChildren) Insert(name string, child *Dentry) error { o.mu.Lock() defer o.mu.Unlock() if _, ok := o.set[name]; ok { @@ -421,10 +448,10 @@ func (o *OrderedChildren) removeLocked(name string) { } // Precondition: caller must hold o.mu for writing. -func (o *OrderedChildren) replaceChildLocked(name string, new *vfs.Dentry) *vfs.Dentry { +func (o *OrderedChildren) replaceChildLocked(name string, new *Dentry) *Dentry { if s, ok := o.set[name]; ok { // Existing slot with given name, simply replace the dentry. - var old *vfs.Dentry + var old *Dentry old, s.Dentry = s.Dentry, new return old } @@ -440,7 +467,7 @@ func (o *OrderedChildren) replaceChildLocked(name string, new *vfs.Dentry) *vfs. } // Precondition: caller must hold o.mu for reading or writing. -func (o *OrderedChildren) checkExistingLocked(name string, child *vfs.Dentry) error { +func (o *OrderedChildren) checkExistingLocked(name string, child *Dentry) error { s, ok := o.set[name] if !ok { return syserror.ENOENT @@ -452,7 +479,7 @@ func (o *OrderedChildren) checkExistingLocked(name string, child *vfs.Dentry) er } // Unlink implements Inode.Unlink. -func (o *OrderedChildren) Unlink(ctx context.Context, name string, child *vfs.Dentry) error { +func (o *OrderedChildren) Unlink(ctx context.Context, name string, child *Dentry) error { if !o.writable { return syserror.EPERM } @@ -468,12 +495,13 @@ func (o *OrderedChildren) Unlink(ctx context.Context, name string, child *vfs.De } // Rmdir implements Inode.Rmdir. -func (o *OrderedChildren) RmDir(ctx context.Context, name string, child *vfs.Dentry) error { +func (o *OrderedChildren) RmDir(ctx context.Context, name string, child *Dentry) error { // We're not responsible for checking that child is a directory, that it's // empty, or updating any link counts; so this is the same as unlink. return o.Unlink(ctx, name, child) } +// +stateify savable type renameAcrossDifferentImplementationsError struct{} func (renameAcrossDifferentImplementationsError) Error() string { @@ -489,8 +517,8 @@ func (renameAcrossDifferentImplementationsError) Error() string { // that will support Rename. // // Postcondition: reference on any replaced dentry transferred to caller. -func (o *OrderedChildren) Rename(ctx context.Context, oldname, newname string, child, dstDir *vfs.Dentry) (*vfs.Dentry, error) { - dst, ok := dstDir.Impl().(*Dentry).inode.(interface{}).(*OrderedChildren) +func (o *OrderedChildren) Rename(ctx context.Context, oldname, newname string, child, dstDir *Dentry) (*Dentry, error) { + dst, ok := dstDir.inode.(interface{}).(*OrderedChildren) if !ok { return nil, renameAcrossDifferentImplementationsError{} } @@ -532,12 +560,14 @@ func (o *OrderedChildren) nthLocked(i int64) *slot { } // InodeSymlink partially implements Inode interface for symlinks. +// +// +stateify savable type InodeSymlink struct { InodeNotDirectory } // Open implements Inode.Open. -func (InodeSymlink) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { +func (InodeSymlink) Open(ctx context.Context, rp *vfs.ResolvingPath, d *Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { return nil, syserror.ELOOP } @@ -564,6 +594,7 @@ var _ Inode = (*StaticDirectory)(nil) func NewStaticDir(creds *auth.Credentials, devMajor, devMinor uint32, ino uint64, perm linux.FileMode, children map[string]*Dentry, fdOpts GenericDirectoryFDOptions) *Dentry { inode := &StaticDirectory{} inode.Init(creds, devMajor, devMinor, ino, perm, fdOpts) + inode.EnableLeakCheck() dentry := &Dentry{} dentry.Init(inode) @@ -584,9 +615,9 @@ func (s *StaticDirectory) Init(creds *auth.Credentials, devMajor, devMinor uint3 s.InodeAttrs.Init(creds, devMajor, devMinor, ino, linux.ModeDirectory|perm) } -// Open implements kernfs.Inode. -func (s *StaticDirectory) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { - fd, err := NewGenericDirectoryFD(rp.Mount(), vfsd, &s.OrderedChildren, &s.locks, &opts, s.fdOpts) +// Open implements kernfs.Inode.Open. +func (s *StaticDirectory) Open(ctx context.Context, rp *vfs.ResolvingPath, d *Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { + fd, err := NewGenericDirectoryFD(rp.Mount(), d, &s.OrderedChildren, &s.locks, &opts, s.fdOpts) if err != nil { return nil, err } @@ -598,21 +629,25 @@ func (*StaticDirectory) SetStat(context.Context, *vfs.Filesystem, *auth.Credenti return syserror.EPERM } -// DecRef implements kernfs.Inode. +// DecRef implements kernfs.Inode.DecRef. func (s *StaticDirectory) DecRef(context.Context) { s.StaticDirectoryRefs.DecRef(s.Destroy) } // AlwaysValid partially implements kernfs.inodeDynamicLookup. +// +// +stateify savable type AlwaysValid struct{} -// Valid implements kernfs.inodeDynamicLookup. +// Valid implements kernfs.inodeDynamicLookup.Valid. func (*AlwaysValid) Valid(context.Context) bool { return true } // InodeNoStatFS partially implements the Inode interface, where the client // filesystem doesn't support statfs(2). +// +// +stateify savable type InodeNoStatFS struct{} // StatFS implements Inode.StatFS. diff --git a/pkg/sentry/fsimpl/kernfs/kernfs.go b/pkg/sentry/fsimpl/kernfs/kernfs.go index 88fcd54aa..6d3d79333 100644 --- a/pkg/sentry/fsimpl/kernfs/kernfs.go +++ b/pkg/sentry/fsimpl/kernfs/kernfs.go @@ -29,7 +29,7 @@ // // Reference Model: // -// Kernfs dentries represents named pointers to inodes. Dentries and inode have +// Kernfs dentries represents named pointers to inodes. Dentries and inodes have // independent lifetimes and reference counts. A child dentry unconditionally // holds a reference on its parent directory's dentry. A dentry also holds a // reference on the inode it points to. Multiple dentries can point to the same @@ -60,20 +60,23 @@ import ( "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/sync" + "gvisor.dev/gvisor/pkg/syserror" ) // Filesystem mostly implements vfs.FilesystemImpl for a generic in-memory // filesystem. Concrete implementations are expected to embed this in their own // Filesystem type. +// +// +stateify savable type Filesystem struct { vfsfs vfs.Filesystem - droppedDentriesMu sync.Mutex + droppedDentriesMu sync.Mutex `state:"nosave"` // droppedDentries is a list of dentries waiting to be DecRef()ed. This is // used to defer dentry destruction until mu can be acquired for // writing. Protected by droppedDentriesMu. - droppedDentries []*vfs.Dentry + droppedDentries []*Dentry // mu synchronizes the lifetime of Dentries on this filesystem. Holding it // for reading guarantees continued existence of any resolved dentries, but @@ -96,7 +99,7 @@ type Filesystem struct { // defer fs.mu.RUnlock() // ... // fs.deferDecRef(dentry) - mu sync.RWMutex + mu sync.RWMutex `state:"nosave"` // nextInoMinusOne is used to to allocate inode numbers on this // filesystem. Must be accessed by atomic operations. @@ -107,7 +110,7 @@ type Filesystem struct { // processDeferredDecRefs{,Locked}. See comment on Filesystem.mu. // // Precondition: d must not already be pending destruction. -func (fs *Filesystem) deferDecRef(d *vfs.Dentry) { +func (fs *Filesystem) deferDecRef(d *Dentry) { fs.droppedDentriesMu.Lock() fs.droppedDentries = append(fs.droppedDentries, d) fs.droppedDentriesMu.Unlock() @@ -159,6 +162,8 @@ const ( // to, and child dentries hold a reference on their parent. // // Must be initialized by Init prior to first use. +// +// +stateify savable type Dentry struct { DentryRefs @@ -172,7 +177,11 @@ type Dentry struct { name string // dirMu protects children and the names of child Dentries. - dirMu sync.Mutex + // + // Note that holding fs.mu for writing is not sufficient; + // revalidateChildLocked(), which is a very hot path, may modify children with + // fs.mu acquired for reading only. + dirMu sync.Mutex `state:"nosave"` children map[string]*Dentry inode Inode @@ -239,24 +248,25 @@ func (d *Dentry) Watches() *vfs.Watches { func (d *Dentry) OnZeroWatches(context.Context) {} // InsertChild inserts child into the vfs dentry cache with the given name under -// this dentry. This does not update the directory inode, so calling this on -// its own isn't sufficient to insert a child into a directory. InsertChild -// updates the link count on d if required. +// this dentry. This does not update the directory inode, so calling this on its +// own isn't sufficient to insert a child into a directory. // // Precondition: d must represent a directory inode. func (d *Dentry) InsertChild(name string, child *Dentry) { d.dirMu.Lock() - d.insertChildLocked(name, child) + d.InsertChildLocked(name, child) d.dirMu.Unlock() } -// insertChildLocked is equivalent to InsertChild, with additional +// InsertChildLocked is equivalent to InsertChild, with additional // preconditions. // -// Precondition: d.dirMu must be locked. -func (d *Dentry) insertChildLocked(name string, child *Dentry) { +// Preconditions: +// * d must represent a directory inode. +// * d.dirMu must be locked. +func (d *Dentry) InsertChildLocked(name string, child *Dentry) { if !d.isDir() { - panic(fmt.Sprintf("InsertChild called on non-directory Dentry: %+v.", d)) + panic(fmt.Sprintf("InsertChildLocked called on non-directory Dentry: %+v.", d)) } d.IncRef() // DecRef in child's Dentry.destroy. child.parent = d @@ -267,6 +277,36 @@ func (d *Dentry) insertChildLocked(name string, child *Dentry) { d.children[name] = child } +// RemoveChild removes child from the vfs dentry cache. This does not update the +// directory inode or modify the inode to be unlinked. So calling this on its own +// isn't sufficient to remove a child from a directory. +// +// Precondition: d must represent a directory inode. +func (d *Dentry) RemoveChild(name string, child *Dentry) error { + d.dirMu.Lock() + defer d.dirMu.Unlock() + return d.RemoveChildLocked(name, child) +} + +// RemoveChildLocked is equivalent to RemoveChild, with additional +// preconditions. +// +// Precondition: d.dirMu must be locked. +func (d *Dentry) RemoveChildLocked(name string, child *Dentry) error { + if !d.isDir() { + panic(fmt.Sprintf("RemoveChild called on non-directory Dentry: %+v.", d)) + } + c, ok := d.children[name] + if !ok { + return syserror.ENOENT + } + if c != child { + panic(fmt.Sprintf("Dentry hashed into inode doesn't match what vfs thinks! Child: %+v, vfs: %+v", c, child)) + } + delete(d.children, name) + return nil +} + // Inode returns the dentry's inode. func (d *Dentry) Inode() Inode { return d.inode @@ -287,7 +327,6 @@ func (d *Dentry) Inode() Inode { // // - Checking that dentries passed to methods are of the appropriate file type. // - Checking permissions. -// - Updating link and reference counts. // // Specific responsibilities of implementations are documented below. type Inode interface { @@ -297,7 +336,8 @@ type Inode interface { inodeRefs // Methods related to node metadata. A generic implementation is provided by - // InodeAttrs. + // InodeAttrs. Note that a concrete filesystem using kernfs is responsible for + // managing link counts. inodeMetadata // Method for inodes that represent symlink. InodeNotSymlink provides a @@ -315,11 +355,11 @@ type Inode interface { // Open creates a file description for the filesystem object represented by // this inode. The returned file description should hold a reference on the - // inode for its lifetime. + // dentry for its lifetime. // // Precondition: rp.Done(). vfsd.Impl() must be the kernfs Dentry containing // the inode on which Open() is being called. - Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) + Open(ctx context.Context, rp *vfs.ResolvingPath, d *Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) // StatFS returns filesystem statistics for the client filesystem. This // corresponds to vfs.FilesystemImpl.StatFSAt. If the client filesystem @@ -369,30 +409,30 @@ type inodeDirectory interface { HasChildren() bool // NewFile creates a new regular file inode. - NewFile(ctx context.Context, name string, opts vfs.OpenOptions) (*vfs.Dentry, error) + NewFile(ctx context.Context, name string, opts vfs.OpenOptions) (*Dentry, error) // NewDir creates a new directory inode. - NewDir(ctx context.Context, name string, opts vfs.MkdirOptions) (*vfs.Dentry, error) + NewDir(ctx context.Context, name string, opts vfs.MkdirOptions) (*Dentry, error) // NewLink creates a new hardlink to a specified inode in this // directory. Implementations should create a new kernfs Dentry pointing to // target, and update target's link count. - NewLink(ctx context.Context, name string, target Inode) (*vfs.Dentry, error) + NewLink(ctx context.Context, name string, target Inode) (*Dentry, error) // NewSymlink creates a new symbolic link inode. - NewSymlink(ctx context.Context, name, target string) (*vfs.Dentry, error) + NewSymlink(ctx context.Context, name, target string) (*Dentry, error) // NewNode creates a new filesystem node for a mknod syscall. - NewNode(ctx context.Context, name string, opts vfs.MknodOptions) (*vfs.Dentry, error) + NewNode(ctx context.Context, name string, opts vfs.MknodOptions) (*Dentry, error) // Unlink removes a child dentry from this directory inode. - Unlink(ctx context.Context, name string, child *vfs.Dentry) error + Unlink(ctx context.Context, name string, child *Dentry) error // RmDir removes an empty child directory from this directory // inode. Implementations must update the parent directory's link count, // if required. Implementations are not responsible for checking that child // is a directory, checking for an empty directory. - RmDir(ctx context.Context, name string, child *vfs.Dentry) error + RmDir(ctx context.Context, name string, child *Dentry) error // Rename is called on the source directory containing an inode being // renamed. child should point to the resolved child in the source @@ -400,7 +440,7 @@ type inodeDirectory interface { // should return the replaced dentry or nil otherwise. // // Precondition: Caller must serialize concurrent calls to Rename. - Rename(ctx context.Context, oldname, newname string, child, dstDir *vfs.Dentry) (replaced *vfs.Dentry, err error) + Rename(ctx context.Context, oldname, newname string, child, dstDir *Dentry) (replaced *Dentry, err error) } type inodeDynamicLookup interface { @@ -418,14 +458,14 @@ type inodeDynamicLookup interface { // // Lookup returns the child with an extra reference and the caller owns this // reference. - Lookup(ctx context.Context, name string) (*vfs.Dentry, error) + Lookup(ctx context.Context, name string) (*Dentry, error) // Valid should return true if this inode is still valid, or needs to // be resolved again by a call to Lookup. Valid(ctx context.Context) bool // IterDirents is used to iterate over dynamically created entries. It invokes - // cb on each entry in the directory represented by the FileDescription. + // cb on each entry in the directory represented by the Inode. // 'offset' is the offset for the entire IterDirents call, which may include // results from the caller (e.g. "." and ".."). 'relOffset' is the offset // inside the entries returned by this IterDirents invocation. In other words, @@ -437,7 +477,7 @@ type inodeDynamicLookup interface { type inodeSymlink interface { // Readlink returns the target of a symbolic link. If an inode is not a // symlink, the implementation should return EINVAL. - Readlink(ctx context.Context) (string, error) + Readlink(ctx context.Context, mnt *vfs.Mount) (string, error) // Getlink returns the target of a symbolic link, as used by path // resolution: diff --git a/pkg/sentry/fsimpl/kernfs/kernfs_test.go b/pkg/sentry/fsimpl/kernfs/kernfs_test.go index 675587c6b..e413242dc 100644 --- a/pkg/sentry/fsimpl/kernfs/kernfs_test.go +++ b/pkg/sentry/fsimpl/kernfs/kernfs_test.go @@ -52,7 +52,7 @@ func newTestSystem(t *testing.T, rootFn RootDentryFn) *testutil.System { v.MustRegisterFilesystemType("testfs", &fsType{rootFn: rootFn}, &vfs.RegisterFilesystemTypeOptions{ AllowUserMount: true, }) - mns, err := v.NewMountNamespace(ctx, creds, "", "testfs", &vfs.GetFilesystemOptions{}) + mns, err := v.NewMountNamespace(ctx, creds, "", "testfs", &vfs.MountOptions{}) if err != nil { t.Fatalf("Failed to create testfs root mount: %v", err) } @@ -121,8 +121,8 @@ func (fs *filesystem) newReadonlyDir(creds *auth.Credentials, mode linux.FileMod return &dir.dentry } -func (d *readonlyDir) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { - fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &d.OrderedChildren, &d.locks, &opts, kernfs.GenericDirectoryFDOptions{ +func (d *readonlyDir) Open(ctx context.Context, rp *vfs.ResolvingPath, kd *kernfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { + fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), kd, &d.OrderedChildren, &d.locks, &opts, kernfs.GenericDirectoryFDOptions{ SeekEnd: kernfs.SeekEndStaticEntries, }) if err != nil { @@ -162,8 +162,8 @@ func (fs *filesystem) newDir(creds *auth.Credentials, mode linux.FileMode, conte return &dir.dentry } -func (d *dir) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { - fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &d.OrderedChildren, &d.locks, &opts, kernfs.GenericDirectoryFDOptions{ +func (d *dir) Open(ctx context.Context, rp *vfs.ResolvingPath, kd *kernfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { + fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), kd, &d.OrderedChildren, &d.locks, &opts, kernfs.GenericDirectoryFDOptions{ SeekEnd: kernfs.SeekEndStaticEntries, }) if err != nil { @@ -176,38 +176,36 @@ func (d *dir) DecRef(context.Context) { d.dirRefs.DecRef(d.Destroy) } -func (d *dir) NewDir(ctx context.Context, name string, opts vfs.MkdirOptions) (*vfs.Dentry, error) { +func (d *dir) NewDir(ctx context.Context, name string, opts vfs.MkdirOptions) (*kernfs.Dentry, error) { creds := auth.CredentialsFromContext(ctx) dir := d.fs.newDir(creds, opts.Mode, nil) - dirVFSD := dir.VFSDentry() - if err := d.OrderedChildren.Insert(name, dirVFSD); err != nil { + if err := d.OrderedChildren.Insert(name, dir); err != nil { dir.DecRef(ctx) return nil, err } d.IncLinks(1) - return dirVFSD, nil + return dir, nil } -func (d *dir) NewFile(ctx context.Context, name string, opts vfs.OpenOptions) (*vfs.Dentry, error) { +func (d *dir) NewFile(ctx context.Context, name string, opts vfs.OpenOptions) (*kernfs.Dentry, error) { creds := auth.CredentialsFromContext(ctx) f := d.fs.newFile(creds, "") - fVFSD := f.VFSDentry() - if err := d.OrderedChildren.Insert(name, fVFSD); err != nil { + if err := d.OrderedChildren.Insert(name, f); err != nil { f.DecRef(ctx) return nil, err } - return fVFSD, nil + return f, nil } -func (*dir) NewLink(context.Context, string, kernfs.Inode) (*vfs.Dentry, error) { +func (*dir) NewLink(context.Context, string, kernfs.Inode) (*kernfs.Dentry, error) { return nil, syserror.EPERM } -func (*dir) NewSymlink(context.Context, string, string) (*vfs.Dentry, error) { +func (*dir) NewSymlink(context.Context, string, string) (*kernfs.Dentry, error) { return nil, syserror.EPERM } -func (*dir) NewNode(context.Context, string, vfs.MknodOptions) (*vfs.Dentry, error) { +func (*dir) NewNode(context.Context, string, vfs.MknodOptions) (*kernfs.Dentry, error) { return nil, syserror.EPERM } diff --git a/pkg/sentry/fsimpl/kernfs/symlink.go b/pkg/sentry/fsimpl/kernfs/symlink.go index 64731a3e4..58a93eaac 100644 --- a/pkg/sentry/fsimpl/kernfs/symlink.go +++ b/pkg/sentry/fsimpl/kernfs/symlink.go @@ -24,6 +24,8 @@ import ( // StaticSymlink provides an Inode implementation for symlinks that point to // a immutable target. +// +// +stateify savable type StaticSymlink struct { InodeAttrs InodeNoopRefCount @@ -51,8 +53,8 @@ func (s *StaticSymlink) Init(creds *auth.Credentials, devMajor uint32, devMinor s.InodeAttrs.Init(creds, devMajor, devMinor, ino, linux.ModeSymlink|0777) } -// Readlink implements Inode. -func (s *StaticSymlink) Readlink(_ context.Context) (string, error) { +// Readlink implements Inode.Readlink. +func (s *StaticSymlink) Readlink(_ context.Context, _ *vfs.Mount) (string, error) { return s.target, nil } diff --git a/pkg/sentry/fsimpl/kernfs/synthetic_directory.go b/pkg/sentry/fsimpl/kernfs/synthetic_directory.go new file mode 100644 index 000000000..ea7f073eb --- /dev/null +++ b/pkg/sentry/fsimpl/kernfs/synthetic_directory.go @@ -0,0 +1,102 @@ +// Copyright 2019 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package kernfs + +import ( + "fmt" + + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/sentry/kernel/auth" + "gvisor.dev/gvisor/pkg/sentry/vfs" + "gvisor.dev/gvisor/pkg/syserror" +) + +// syntheticDirectory implements kernfs.Inode for a directory created by +// MkdirAt(ForSyntheticMountpoint=true). +// +// +stateify savable +type syntheticDirectory struct { + InodeAttrs + InodeNoStatFS + InodeNoopRefCount + InodeNoDynamicLookup + InodeNotSymlink + OrderedChildren + + locks vfs.FileLocks +} + +var _ Inode = (*syntheticDirectory)(nil) + +func newSyntheticDirectory(creds *auth.Credentials, perm linux.FileMode) *Dentry { + inode := &syntheticDirectory{} + inode.Init(creds, 0 /* devMajor */, 0 /* devMinor */, 0 /* ino */, perm) + d := &Dentry{} + d.Init(inode) + return d +} + +func (dir *syntheticDirectory) Init(creds *auth.Credentials, devMajor, devMinor uint32, ino uint64, perm linux.FileMode) { + if perm&^linux.PermissionsMask != 0 { + panic(fmt.Sprintf("perm contains non-permission bits: %#o", perm)) + } + dir.InodeAttrs.Init(creds, devMajor, devMinor, ino, linux.S_IFDIR|perm) + dir.OrderedChildren.Init(OrderedChildrenOptions{ + Writable: true, + }) +} + +// Open implements Inode.Open. +func (dir *syntheticDirectory) Open(ctx context.Context, rp *vfs.ResolvingPath, d *Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { + fd, err := NewGenericDirectoryFD(rp.Mount(), d, &dir.OrderedChildren, &dir.locks, &opts, GenericDirectoryFDOptions{}) + if err != nil { + return nil, err + } + return &fd.vfsfd, nil +} + +// NewFile implements Inode.NewFile. +func (dir *syntheticDirectory) NewFile(ctx context.Context, name string, opts vfs.OpenOptions) (*Dentry, error) { + return nil, syserror.EPERM +} + +// NewDir implements Inode.NewDir. +func (dir *syntheticDirectory) NewDir(ctx context.Context, name string, opts vfs.MkdirOptions) (*Dentry, error) { + if !opts.ForSyntheticMountpoint { + return nil, syserror.EPERM + } + subdird := newSyntheticDirectory(auth.CredentialsFromContext(ctx), opts.Mode&linux.PermissionsMask) + if err := dir.OrderedChildren.Insert(name, subdird); err != nil { + subdird.DecRef(ctx) + return nil, err + } + return subdird, nil +} + +// NewLink implements Inode.NewLink. +func (dir *syntheticDirectory) NewLink(ctx context.Context, name string, target Inode) (*Dentry, error) { + return nil, syserror.EPERM +} + +// NewSymlink implements Inode.NewSymlink. +func (dir *syntheticDirectory) NewSymlink(ctx context.Context, name, target string) (*Dentry, error) { + return nil, syserror.EPERM +} + +// NewNode implements Inode.NewNode. +func (dir *syntheticDirectory) NewNode(ctx context.Context, name string, opts vfs.MknodOptions) (*Dentry, error) { + return nil, syserror.EPERM +} diff --git a/pkg/sentry/fsimpl/overlay/copy_up.go b/pkg/sentry/fsimpl/overlay/copy_up.go index 13735eb05..73b126669 100644 --- a/pkg/sentry/fsimpl/overlay/copy_up.go +++ b/pkg/sentry/fsimpl/overlay/copy_up.go @@ -23,6 +23,7 @@ import ( "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/fspath" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" + "gvisor.dev/gvisor/pkg/sentry/memmap" "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/usermem" @@ -81,6 +82,8 @@ func (d *dentry) copyUpLocked(ctx context.Context) error { Start: d.parent.upperVD, Path: fspath.Parse(d.name), } + // Used during copy-up of memory-mapped regular files. + var mmapOpts *memmap.MMapOpts cleanupUndoCopyUp := func() { var err error if ftype == linux.S_IFDIR { @@ -89,7 +92,11 @@ func (d *dentry) copyUpLocked(ctx context.Context) error { err = vfsObj.UnlinkAt(ctx, d.fs.creds, &newpop) } if err != nil { - ctx.Warningf("Unrecoverable overlayfs inconsistency: failed to delete upper layer file after copy-up error: %v", err) + panic(fmt.Sprintf("unrecoverable overlayfs inconsistency: failed to delete upper layer file after copy-up error: %v", err)) + } + if d.upperVD.Ok() { + d.upperVD.DecRef(ctx) + d.upperVD = vfs.VirtualDentry{} } } switch ftype { @@ -132,6 +139,25 @@ func (d *dentry) copyUpLocked(ctx context.Context) error { break } } + d.mapsMu.Lock() + defer d.mapsMu.Unlock() + if d.wrappedMappable != nil { + // We may have memory mappings of the file on the lower layer. + // Switch to mapping the file on the upper layer instead. + mmapOpts = &memmap.MMapOpts{ + Perms: usermem.ReadWrite, + MaxPerms: usermem.ReadWrite, + } + if err := newFD.ConfigureMMap(ctx, mmapOpts); err != nil { + cleanupUndoCopyUp() + return err + } + if mmapOpts.MappingIdentity != nil { + mmapOpts.MappingIdentity.DecRef(ctx) + } + // Don't actually switch Mappables until the end of copy-up; see + // below for why. + } if err := newFD.SetStat(ctx, vfs.SetStatOptions{ Stat: linux.Statx{ Mask: linux.STATX_UID | linux.STATX_GID, @@ -234,7 +260,10 @@ func (d *dentry) copyUpLocked(ctx context.Context) error { panic(fmt.Sprintf("unexpected file type %o", ftype)) } - // TODO(gvisor.dev/issue/1199): copy up xattrs + if err := d.copyXattrsLocked(ctx); err != nil { + cleanupUndoCopyUp() + return err + } // Update the dentry's device and inode numbers (except for directories, // for which these remain overlay-assigned). @@ -246,14 +275,10 @@ func (d *dentry) copyUpLocked(ctx context.Context) error { Mask: linux.STATX_INO, }) if err != nil { - d.upperVD.DecRef(ctx) - d.upperVD = vfs.VirtualDentry{} cleanupUndoCopyUp() return err } if upperStat.Mask&linux.STATX_INO == 0 { - d.upperVD.DecRef(ctx) - d.upperVD = vfs.VirtualDentry{} cleanupUndoCopyUp() return syserror.EREMOTE } @@ -262,6 +287,135 @@ func (d *dentry) copyUpLocked(ctx context.Context) error { atomic.StoreUint64(&d.ino, upperStat.Ino) } + if mmapOpts != nil && mmapOpts.Mappable != nil { + // Note that if mmapOpts != nil, then d.mapsMu is locked for writing + // (from the S_IFREG path above). + + // Propagate mappings of d to the new Mappable. Remember which mappings + // we added so we can remove them on failure. + upperMappable := mmapOpts.Mappable + allAdded := make(map[memmap.MappableRange]memmap.MappingsOfRange) + for seg := d.lowerMappings.FirstSegment(); seg.Ok(); seg = seg.NextSegment() { + added := make(memmap.MappingsOfRange) + for m := range seg.Value() { + if err := upperMappable.AddMapping(ctx, m.MappingSpace, m.AddrRange, seg.Start(), m.Writable); err != nil { + for m := range added { + upperMappable.RemoveMapping(ctx, m.MappingSpace, m.AddrRange, seg.Start(), m.Writable) + } + for mr, mappings := range allAdded { + for m := range mappings { + upperMappable.RemoveMapping(ctx, m.MappingSpace, m.AddrRange, mr.Start, m.Writable) + } + } + return err + } + added[m] = struct{}{} + } + allAdded[seg.Range()] = added + } + + // Switch to the new Mappable. We do this at the end of copy-up + // because: + // + // - We need to switch Mappables (by changing d.wrappedMappable) before + // invalidating Translations from the old Mappable (to pick up + // Translations from the new one). + // + // - We need to lock d.dataMu while changing d.wrappedMappable, but + // must invalidate Translations with d.dataMu unlocked (due to lock + // ordering). + // + // - Consequently, once we unlock d.dataMu, other threads may + // immediately observe the new (copied-up) Mappable, which we want to + // delay until copy-up is guaranteed to succeed. + d.dataMu.Lock() + lowerMappable := d.wrappedMappable + d.wrappedMappable = upperMappable + d.dataMu.Unlock() + d.lowerMappings.InvalidateAll(memmap.InvalidateOpts{}) + + // Remove mappings from the old Mappable. + for seg := d.lowerMappings.FirstSegment(); seg.Ok(); seg = seg.NextSegment() { + for m := range seg.Value() { + lowerMappable.RemoveMapping(ctx, m.MappingSpace, m.AddrRange, seg.Start(), m.Writable) + } + } + d.lowerMappings.RemoveAll() + } + atomic.StoreUint32(&d.copiedUp, 1) return nil } + +// copyXattrsLocked copies a subset of lower's extended attributes to upper. +// Attributes that configure an overlay in the lower are not copied up. +// +// Preconditions: d.copyMu must be locked for writing. +func (d *dentry) copyXattrsLocked(ctx context.Context) error { + vfsObj := d.fs.vfsfs.VirtualFilesystem() + lowerPop := &vfs.PathOperation{Root: d.lowerVDs[0], Start: d.lowerVDs[0]} + upperPop := &vfs.PathOperation{Root: d.upperVD, Start: d.upperVD} + + lowerXattrs, err := vfsObj.ListXattrAt(ctx, d.fs.creds, lowerPop, 0) + if err != nil { + if err == syserror.EOPNOTSUPP { + // There are no guarantees as to the contents of lowerXattrs. + return nil + } + ctx.Infof("failed to copy up xattrs because ListXattrAt failed: %v", err) + return err + } + + for _, name := range lowerXattrs { + // Do not copy up overlay attributes. + if isOverlayXattr(name) { + continue + } + + value, err := vfsObj.GetXattrAt(ctx, d.fs.creds, lowerPop, &vfs.GetXattrOptions{Name: name, Size: 0}) + if err != nil { + ctx.Infof("failed to copy up xattrs because GetXattrAt failed: %v", err) + return err + } + + if err := vfsObj.SetXattrAt(ctx, d.fs.creds, upperPop, &vfs.SetXattrOptions{Name: name, Value: value}); err != nil { + ctx.Infof("failed to copy up xattrs because SetXattrAt failed: %v", err) + return err + } + } + return nil +} + +// copyUpDescendantsLocked ensures that all descendants of d are copied up. +// +// Preconditions: +// * filesystem.renameMu must be locked. +// * d.dirMu must be locked. +// * d.isDir(). +func (d *dentry) copyUpDescendantsLocked(ctx context.Context, ds **[]*dentry) error { + dirents, err := d.getDirentsLocked(ctx) + if err != nil { + return err + } + for _, dirent := range dirents { + if dirent.Name == "." || dirent.Name == ".." { + continue + } + child, err := d.fs.getChildLocked(ctx, d, dirent.Name, ds) + if err != nil { + return err + } + if err := child.copyUpLocked(ctx); err != nil { + return err + } + if child.isDir() { + child.dirMu.Lock() + err := child.copyUpDescendantsLocked(ctx, ds) + child.dirMu.Unlock() + if err != nil { + return err + } + } + } + return nil +} diff --git a/pkg/sentry/fsimpl/overlay/directory.go b/pkg/sentry/fsimpl/overlay/directory.go index b1b292e83..df4492346 100644 --- a/pkg/sentry/fsimpl/overlay/directory.go +++ b/pkg/sentry/fsimpl/overlay/directory.go @@ -100,12 +100,13 @@ func (d *dentry) collectWhiteoutsForRmdirLocked(ctx context.Context) (map[string return whiteouts, readdirErr } +// +stateify savable type directoryFD struct { fileDescription vfs.DirectoryFileDescriptionDefaultImpl vfs.DentryMetadataFileDescriptionImpl - mu sync.Mutex + mu sync.Mutex `state:"nosave"` off int64 dirents []vfs.Dirent } @@ -116,10 +117,12 @@ func (fd *directoryFD) Release(ctx context.Context) { // IterDirents implements vfs.FileDescriptionImpl.IterDirents. func (fd *directoryFD) IterDirents(ctx context.Context, cb vfs.IterDirentsCallback) error { + d := fd.dentry() + defer d.InotifyWithParent(ctx, linux.IN_ACCESS, 0, vfs.PathEvent) + fd.mu.Lock() defer fd.mu.Unlock() - d := fd.dentry() if fd.dirents == nil { ds, err := d.getDirents(ctx) if err != nil { @@ -143,7 +146,14 @@ func (d *dentry) getDirents(ctx context.Context) ([]vfs.Dirent, error) { defer d.fs.renameMu.RUnlock() d.dirMu.Lock() defer d.dirMu.Unlock() + return d.getDirentsLocked(ctx) +} +// Preconditions: +// * filesystem.renameMu must be locked. +// * d.dirMu must be locked. +// * d.isDir(). +func (d *dentry) getDirentsLocked(ctx context.Context) ([]vfs.Dirent, error) { if d.dirents != nil { return d.dirents, nil } diff --git a/pkg/sentry/fsimpl/overlay/filesystem.go b/pkg/sentry/fsimpl/overlay/filesystem.go index e720bfb0b..bd11372d5 100644 --- a/pkg/sentry/fsimpl/overlay/filesystem.go +++ b/pkg/sentry/fsimpl/overlay/filesystem.go @@ -15,6 +15,8 @@ package overlay import ( + "fmt" + "strings" "sync/atomic" "gvisor.dev/gvisor/pkg/abi/linux" @@ -27,10 +29,15 @@ import ( "gvisor.dev/gvisor/pkg/syserror" ) +// _OVL_XATTR_PREFIX is an extended attribute key prefix to identify overlayfs +// attributes. +// Linux: fs/overlayfs/overlayfs.h:OVL_XATTR_PREFIX +const _OVL_XATTR_PREFIX = linux.XATTR_TRUSTED_PREFIX + "overlay." + // _OVL_XATTR_OPAQUE is an extended attribute key whose value is set to "y" for // opaque directories. // Linux: fs/overlayfs/overlayfs.h:OVL_XATTR_OPAQUE -const _OVL_XATTR_OPAQUE = linux.XATTR_TRUSTED_PREFIX + "overlay.opaque" +const _OVL_XATTR_OPAQUE = _OVL_XATTR_PREFIX + "opaque" func isWhiteout(stat *linux.Statx) bool { return stat.Mode&linux.S_IFMT == linux.S_IFCHR && stat.RdevMajor == 0 && stat.RdevMinor == 0 @@ -205,6 +212,7 @@ func (fs *filesystem) lookupLocked(ctx context.Context, parent *dentry, name str lookupErr = err return false } + defer childVD.DecRef(ctx) mask := uint32(linux.STATX_TYPE) if !existsOnAnyLayer { @@ -243,6 +251,7 @@ func (fs *filesystem) lookupLocked(ctx context.Context, parent *dentry, name str } // Update child to include this layer. + childVD.IncRef() if isUpper { child.upperVD = childVD child.copiedUp = 1 @@ -267,10 +276,10 @@ func (fs *filesystem) lookupLocked(ctx context.Context, parent *dentry, name str // Directories are merged with directories from lower layers if they // are not explicitly opaque. - opaqueVal, err := vfsObj.GetxattrAt(ctx, fs.creds, &vfs.PathOperation{ + opaqueVal, err := vfsObj.GetXattrAt(ctx, fs.creds, &vfs.PathOperation{ Root: childVD, Start: childVD, - }, &vfs.GetxattrOptions{ + }, &vfs.GetXattrOptions{ Name: _OVL_XATTR_OPAQUE, Size: 1, }) @@ -490,7 +499,13 @@ func (fs *filesystem) doCreateAt(ctx context.Context, rp *vfs.ResolvingPath, dir if err := create(parent, name, childLayer == lookupLayerUpperWhiteout); err != nil { return err } + parent.dirents = nil + ev := linux.IN_CREATE + if dir { + ev |= linux.IN_ISDIR + } + parent.watches.Notify(ctx, name, uint32(ev), 0 /* cookie */, vfs.InodeEvent, false /* unlinked */) return nil } @@ -504,7 +519,7 @@ func (fs *filesystem) createWhiteout(ctx context.Context, vfsObj *vfs.VirtualFil func (fs *filesystem) cleanupRecreateWhiteout(ctx context.Context, vfsObj *vfs.VirtualFilesystem, pop *vfs.PathOperation) { if err := fs.createWhiteout(ctx, vfsObj, pop); err != nil { - ctx.Warningf("Unrecoverable overlayfs inconsistency: failed to recreate whiteout after failed file creation: %v", err) + panic(fmt.Sprintf("unrecoverable overlayfs inconsistency: failed to recreate whiteout after failed file creation: %v", err)) } } @@ -616,12 +631,13 @@ func (fs *filesystem) LinkAt(ctx context.Context, rp *vfs.ResolvingPath, vd vfs. }, }); err != nil { if cleanupErr := vfsObj.UnlinkAt(ctx, fs.creds, &newpop); cleanupErr != nil { - ctx.Warningf("Unrecoverable overlayfs inconsistency: failed to delete upper layer file after LinkAt metadata update failure: %v", cleanupErr) + panic(fmt.Sprintf("unrecoverable overlayfs inconsistency: failed to delete upper layer file after LinkAt metadata update failure: %v", cleanupErr)) } else if haveUpperWhiteout { fs.cleanupRecreateWhiteout(ctx, vfsObj, &newpop) } return err } + old.watches.Notify(ctx, "", linux.IN_ATTRIB, 0 /* cookie */, vfs.InodeEvent, false /* unlinked */) return nil }) } @@ -655,7 +671,7 @@ func (fs *filesystem) MkdirAt(ctx context.Context, rp *vfs.ResolvingPath, opts v }, }); err != nil { if cleanupErr := vfsObj.RmdirAt(ctx, fs.creds, &pop); cleanupErr != nil { - ctx.Warningf("Unrecoverable overlayfs inconsistency: failed to delete upper layer directory after MkdirAt metadata update failure: %v", cleanupErr) + panic(fmt.Sprintf("unrecoverable overlayfs inconsistency: failed to delete upper layer directory after MkdirAt metadata update failure: %v", cleanupErr)) } else if haveUpperWhiteout { fs.cleanupRecreateWhiteout(ctx, vfsObj, &pop) } @@ -665,12 +681,12 @@ func (fs *filesystem) MkdirAt(ctx context.Context, rp *vfs.ResolvingPath, opts v // There may be directories on lower layers (previously hidden by // the whiteout) that the new directory should not be merged with. // Mark it opaque to prevent merging. - if err := vfsObj.SetxattrAt(ctx, fs.creds, &pop, &vfs.SetxattrOptions{ + if err := vfsObj.SetXattrAt(ctx, fs.creds, &pop, &vfs.SetXattrOptions{ Name: _OVL_XATTR_OPAQUE, Value: "y", }); err != nil { if cleanupErr := vfsObj.RmdirAt(ctx, fs.creds, &pop); cleanupErr != nil { - ctx.Warningf("Unrecoverable overlayfs inconsistency: failed to delete upper layer directory after MkdirAt set-opaque failure: %v", cleanupErr) + panic(fmt.Sprintf("unrecoverable overlayfs inconsistency: failed to delete upper layer directory after MkdirAt set-opaque failure: %v", cleanupErr)) } else { fs.cleanupRecreateWhiteout(ctx, vfsObj, &pop) } @@ -714,7 +730,7 @@ func (fs *filesystem) MknodAt(ctx context.Context, rp *vfs.ResolvingPath, opts v }, }); err != nil { if cleanupErr := vfsObj.UnlinkAt(ctx, fs.creds, &pop); cleanupErr != nil { - ctx.Warningf("Unrecoverable overlayfs inconsistency: failed to delete upper layer file after MknodAt metadata update failure: %v", cleanupErr) + panic(fmt.Sprintf("unrecoverable overlayfs inconsistency: failed to delete upper layer file after MknodAt metadata update failure: %v", cleanupErr)) } else if haveUpperWhiteout { fs.cleanupRecreateWhiteout(ctx, vfsObj, &pop) } @@ -743,6 +759,9 @@ func (fs *filesystem) OpenAt(ctx context.Context, rp *vfs.ResolvingPath, opts vf start := rp.Start().Impl().(*dentry) if rp.Done() { + if mayCreate && rp.MustBeDir() { + return nil, syserror.EISDIR + } if mustCreate { return nil, syserror.EEXIST } @@ -766,6 +785,10 @@ afterTrailingSymlink: if err := parent.checkPermissions(rp.Credentials(), vfs.MayExec); err != nil { return nil, err } + // Reject attempts to open directories with O_CREAT. + if mayCreate && rp.MustBeDir() { + return nil, syserror.EISDIR + } // Determine whether or not we need to create a file. parent.dirMu.Lock() child, err := fs.stepLocked(ctx, rp, parent, false /* mayFollowSymlinks */, &ds) @@ -774,12 +797,11 @@ afterTrailingSymlink: parent.dirMu.Unlock() return fd, err } + parent.dirMu.Unlock() if err != nil { - parent.dirMu.Unlock() return nil, err } // Open existing child or follow symlink. - parent.dirMu.Unlock() if mustCreate { return nil, syserror.EEXIST } @@ -794,6 +816,9 @@ afterTrailingSymlink: start = parent goto afterTrailingSymlink } + if rp.MustBeDir() && !child.isDir() { + return nil, syserror.ENOTDIR + } if mayWrite { if err := child.copyUpLocked(ctx); err != nil { return nil, err @@ -925,7 +950,7 @@ func (fs *filesystem) createAndOpenLocked(ctx context.Context, rp *vfs.Resolving }, }); err != nil { if cleanupErr := vfsObj.UnlinkAt(ctx, fs.creds, &pop); cleanupErr != nil { - ctx.Warningf("Unrecoverable overlayfs inconsistency: failed to delete upper layer file after OpenAt(O_CREAT) metadata update failure: %v", cleanupErr) + panic(fmt.Sprintf("unrecoverable overlayfs inconsistency: failed to delete upper layer file after OpenAt(O_CREAT) metadata update failure: %v", cleanupErr)) } else if haveUpperWhiteout { fs.cleanupRecreateWhiteout(ctx, vfsObj, &pop) } @@ -936,7 +961,7 @@ func (fs *filesystem) createAndOpenLocked(ctx context.Context, rp *vfs.Resolving child, err := fs.getChildLocked(ctx, parent, childName, ds) if err != nil { if cleanupErr := vfsObj.UnlinkAt(ctx, fs.creds, &pop); cleanupErr != nil { - ctx.Warningf("Unrecoverable overlayfs inconsistency: failed to delete upper layer file after OpenAt(O_CREAT) dentry lookup failure: %v", cleanupErr) + panic(fmt.Sprintf("unrecoverable overlayfs inconsistency: failed to delete upper layer file after OpenAt(O_CREAT) dentry lookup failure: %v", cleanupErr)) } else if haveUpperWhiteout { fs.cleanupRecreateWhiteout(ctx, vfsObj, &pop) } @@ -957,6 +982,7 @@ func (fs *filesystem) createAndOpenLocked(ctx context.Context, rp *vfs.Resolving // just can't open it anymore for some reason. return nil, err } + parent.watches.Notify(ctx, childName, linux.IN_CREATE, 0 /* cookie */, vfs.PathEvent, false /* unlinked */) return &fd.vfsfd, nil } @@ -1002,9 +1028,224 @@ func (fs *filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa } defer mnt.EndWrite() - // FIXME(gvisor.dev/issue/1199): Actually implement rename. - _ = newParent - return syserror.EXDEV + oldParent := oldParentVD.Dentry().Impl().(*dentry) + creds := rp.Credentials() + if err := oldParent.checkPermissions(creds, vfs.MayWrite|vfs.MayExec); err != nil { + return err + } + // We need a dentry representing the renamed file since, if it's a + // directory, we need to check for write permission on it. + oldParent.dirMu.Lock() + defer oldParent.dirMu.Unlock() + renamed, err := fs.getChildLocked(ctx, oldParent, oldName, &ds) + if err != nil { + return err + } + if err := vfs.CheckDeleteSticky(creds, linux.FileMode(atomic.LoadUint32(&oldParent.mode)), auth.KUID(atomic.LoadUint32(&renamed.uid))); err != nil { + return err + } + if renamed.isDir() { + if renamed == newParent || genericIsAncestorDentry(renamed, newParent) { + return syserror.EINVAL + } + if oldParent != newParent { + if err := renamed.checkPermissions(creds, vfs.MayWrite); err != nil { + return err + } + } + } else { + if opts.MustBeDir || rp.MustBeDir() { + return syserror.ENOTDIR + } + } + + if oldParent != newParent { + if err := newParent.checkPermissions(creds, vfs.MayWrite|vfs.MayExec); err != nil { + return err + } + newParent.dirMu.Lock() + defer newParent.dirMu.Unlock() + } + if newParent.vfsd.IsDead() { + return syserror.ENOENT + } + replacedLayer, err := fs.lookupLayerLocked(ctx, newParent, newName) + if err != nil { + return err + } + var ( + replaced *dentry + replacedVFSD *vfs.Dentry + whiteouts map[string]bool + ) + if replacedLayer.existsInOverlay() { + replaced, err = fs.getChildLocked(ctx, newParent, newName, &ds) + if err != nil { + return err + } + replacedVFSD = &replaced.vfsd + if replaced.isDir() { + if !renamed.isDir() { + return syserror.EISDIR + } + if genericIsAncestorDentry(replaced, renamed) { + return syserror.ENOTEMPTY + } + replaced.dirMu.Lock() + defer replaced.dirMu.Unlock() + whiteouts, err = replaced.collectWhiteoutsForRmdirLocked(ctx) + if err != nil { + return err + } + } else { + if rp.MustBeDir() || renamed.isDir() { + return syserror.ENOTDIR + } + } + } + + if oldParent == newParent && oldName == newName { + return nil + } + + // renamed and oldParent need to be copied-up before they're renamed on the + // upper layer. + if err := renamed.copyUpLocked(ctx); err != nil { + return err + } + // If renamed is a directory, all of its descendants need to be copied-up + // before they're renamed on the upper layer. + if renamed.isDir() { + if err := renamed.copyUpDescendantsLocked(ctx, &ds); err != nil { + return err + } + } + // newParent must be copied-up before it can contain renamed on the upper + // layer. + if err := newParent.copyUpLocked(ctx); err != nil { + return err + } + // If replaced exists, it doesn't need to be copied-up, but we do need to + // serialize with copy-up. Holding renameMu for writing should be + // sufficient, but out of an abundance of caution... + if replaced != nil { + replaced.copyMu.RLock() + defer replaced.copyMu.RUnlock() + } + + vfsObj := rp.VirtualFilesystem() + mntns := vfs.MountNamespaceFromContext(ctx) + defer mntns.DecRef(ctx) + if err := vfsObj.PrepareRenameDentry(mntns, &renamed.vfsd, replacedVFSD); err != nil { + return err + } + + newpop := vfs.PathOperation{ + Root: newParent.upperVD, + Start: newParent.upperVD, + Path: fspath.Parse(newName), + } + + needRecreateWhiteouts := false + cleanupRecreateWhiteouts := func() { + if !needRecreateWhiteouts { + return + } + for whiteoutName, whiteoutUpper := range whiteouts { + if !whiteoutUpper { + continue + } + if err := fs.createWhiteout(ctx, vfsObj, &vfs.PathOperation{ + Root: replaced.upperVD, + Start: replaced.upperVD, + Path: fspath.Parse(whiteoutName), + }); err != nil && err != syserror.EEXIST { + panic(fmt.Sprintf("unrecoverable overlayfs inconsistency: failed to recreate deleted whiteout after RenameAt failure: %v", err)) + } + } + } + if renamed.isDir() { + if replacedLayer == lookupLayerUpper { + // Remove whiteouts from the directory being replaced. + needRecreateWhiteouts = true + for whiteoutName, whiteoutUpper := range whiteouts { + if !whiteoutUpper { + continue + } + if err := vfsObj.UnlinkAt(ctx, fs.creds, &vfs.PathOperation{ + Root: replaced.upperVD, + Start: replaced.upperVD, + Path: fspath.Parse(whiteoutName), + }); err != nil { + cleanupRecreateWhiteouts() + vfsObj.AbortRenameDentry(&renamed.vfsd, replacedVFSD) + return err + } + } + } else if replacedLayer == lookupLayerUpperWhiteout { + // We need to explicitly remove the whiteout since otherwise rename + // on the upper layer will fail with ENOTDIR. + if err := vfsObj.UnlinkAt(ctx, fs.creds, &newpop); err != nil { + vfsObj.AbortRenameDentry(&renamed.vfsd, replacedVFSD) + return err + } + } + } + + // Essentially no gVisor filesystem supports RENAME_WHITEOUT, so just do a + // regular rename and create the whiteout at the origin manually. Unlike + // RENAME_WHITEOUT, this isn't atomic with respect to other users of the + // upper filesystem, but this is already the case for virtually all other + // overlay filesystem operations too. + oldpop := vfs.PathOperation{ + Root: oldParent.upperVD, + Start: oldParent.upperVD, + Path: fspath.Parse(oldName), + } + if err := vfsObj.RenameAt(ctx, creds, &oldpop, &newpop, &opts); err != nil { + cleanupRecreateWhiteouts() + vfsObj.AbortRenameDentry(&renamed.vfsd, replacedVFSD) + return err + } + + // Below this point, the renamed dentry is now at newpop, and anything we + // replaced is gone forever. Commit the rename, update the overlay + // filesystem tree, and abandon attempts to recover from errors. + vfsObj.CommitRenameReplaceDentry(ctx, &renamed.vfsd, replacedVFSD) + delete(oldParent.children, oldName) + if replaced != nil { + ds = appendDentry(ds, replaced) + } + if oldParent != newParent { + newParent.dirents = nil + // This can't drop the last reference on oldParent because one is held + // by oldParentVD, so lock recursion is impossible. + oldParent.DecRef(ctx) + ds = appendDentry(ds, oldParent) + newParent.IncRef() + renamed.parent = newParent + } + renamed.name = newName + if newParent.children == nil { + newParent.children = make(map[string]*dentry) + } + newParent.children[newName] = renamed + oldParent.dirents = nil + + if err := fs.createWhiteout(ctx, vfsObj, &oldpop); err != nil { + panic(fmt.Sprintf("unrecoverable overlayfs inconsistency: failed to create whiteout at origin after RenameAt: %v", err)) + } + if renamed.isDir() { + if err := vfsObj.SetXattrAt(ctx, fs.creds, &newpop, &vfs.SetXattrOptions{ + Name: _OVL_XATTR_OPAQUE, + Value: "y", + }); err != nil { + panic(fmt.Sprintf("unrecoverable overlayfs inconsistency: failed to make renamed directory opaque: %v", err)) + } + } + + vfs.InotifyRename(ctx, &renamed.watches, &oldParent.watches, &newParent.watches, oldName, newName, renamed.isDir()) + return nil } // RmdirAt implements vfs.FilesystemImpl.RmdirAt. @@ -1083,7 +1324,7 @@ func (fs *filesystem) RmdirAt(ctx context.Context, rp *vfs.ResolvingPath) error Start: child.upperVD, Path: fspath.Parse(whiteoutName), }); err != nil && err != syserror.EEXIST { - ctx.Warningf("Unrecoverable overlayfs inconsistency: failed to recreate deleted whiteout after RmdirAt failure: %v", err) + panic(fmt.Sprintf("unrecoverable overlayfs inconsistency: failed to recreate deleted whiteout after RmdirAt failure: %v", err)) } } } @@ -1113,15 +1354,14 @@ func (fs *filesystem) RmdirAt(ctx context.Context, rp *vfs.ResolvingPath) error // Don't attempt to recover from this: the original directory is // already gone, so any dentries representing it are invalid, and // creating a new directory won't undo that. - ctx.Warningf("Unrecoverable overlayfs inconsistency: failed to create whiteout during RmdirAt: %v", err) - vfsObj.AbortDeleteDentry(&child.vfsd) - return err + panic(fmt.Sprintf("unrecoverable overlayfs inconsistency: failed to create whiteout during RmdirAt: %v", err)) } vfsObj.CommitDeleteDentry(ctx, &child.vfsd) delete(parent.children, name) ds = appendDentry(ds, child) parent.dirents = nil + parent.watches.Notify(ctx, name, linux.IN_DELETE|linux.IN_ISDIR, 0 /* cookie */, vfs.InodeEvent, true /* unlinked */) return nil } @@ -1129,12 +1369,25 @@ func (fs *filesystem) RmdirAt(ctx context.Context, rp *vfs.ResolvingPath) error func (fs *filesystem) SetStatAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.SetStatOptions) error { var ds *[]*dentry fs.renameMu.RLock() - defer fs.renameMuRUnlockAndCheckDrop(ctx, &ds) d, err := fs.resolveLocked(ctx, rp, &ds) if err != nil { + fs.renameMuRUnlockAndCheckDrop(ctx, &ds) return err } + err = d.setStatLocked(ctx, rp, opts) + fs.renameMuRUnlockAndCheckDrop(ctx, &ds) + if err != nil { + return err + } + + if ev := vfs.InotifyEventFromStatMask(opts.Stat.Mask); ev != 0 { + d.InotifyWithParent(ctx, ev, 0 /* cookie */, vfs.InodeEvent) + } + return nil +} +// Precondition: d.fs.renameMu must be held for reading. +func (d *dentry) setStatLocked(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.SetStatOptions) error { mode := linux.FileMode(atomic.LoadUint32(&d.mode)) if err := vfs.CheckSetStat(ctx, rp.Credentials(), &opts, mode, auth.KUID(atomic.LoadUint32(&d.uid)), auth.KGID(atomic.LoadUint32(&d.gid))); err != nil { return err @@ -1229,7 +1482,7 @@ func (fs *filesystem) SymlinkAt(ctx context.Context, rp *vfs.ResolvingPath, targ }, }); err != nil { if cleanupErr := vfsObj.UnlinkAt(ctx, fs.creds, &pop); cleanupErr != nil { - ctx.Warningf("Unrecoverable overlayfs inconsistency: failed to delete upper layer file after SymlinkAt metadata update failure: %v", cleanupErr) + panic(fmt.Sprintf("unrecoverable overlayfs inconsistency: failed to delete upper layer file after SymlinkAt metadata update failure: %v", cleanupErr)) } else if haveUpperWhiteout { fs.cleanupRecreateWhiteout(ctx, vfsObj, &pop) } @@ -1322,70 +1575,175 @@ func (fs *filesystem) UnlinkAt(ctx context.Context, rp *vfs.ResolvingPath) error } } if err := fs.createWhiteout(ctx, vfsObj, &pop); err != nil { - ctx.Warningf("Unrecoverable overlayfs inconsistency: failed to create whiteout during UnlinkAt: %v", err) - if child != nil { - vfsObj.AbortDeleteDentry(&child.vfsd) - } - return err + panic(fmt.Sprintf("unrecoverable overlayfs inconsistency: failed to create whiteout during UnlinkAt: %v", err)) } + var cw *vfs.Watches if child != nil { vfsObj.CommitDeleteDentry(ctx, &child.vfsd) delete(parent.children, name) ds = appendDentry(ds, child) + cw = &child.watches } + vfs.InotifyRemoveChild(ctx, cw, &parent.watches, name) parent.dirents = nil return nil } -// ListxattrAt implements vfs.FilesystemImpl.ListxattrAt. -func (fs *filesystem) ListxattrAt(ctx context.Context, rp *vfs.ResolvingPath, size uint64) ([]string, error) { +// isOverlayXattr returns whether the given extended attribute configures the +// overlay. +func isOverlayXattr(name string) bool { + return strings.HasPrefix(name, _OVL_XATTR_PREFIX) +} + +// ListXattrAt implements vfs.FilesystemImpl.ListXattrAt. +func (fs *filesystem) ListXattrAt(ctx context.Context, rp *vfs.ResolvingPath, size uint64) ([]string, error) { var ds *[]*dentry fs.renameMu.RLock() defer fs.renameMuRUnlockAndCheckDrop(ctx, &ds) - _, err := fs.resolveLocked(ctx, rp, &ds) + d, err := fs.resolveLocked(ctx, rp, &ds) if err != nil { return nil, err } - // TODO(gvisor.dev/issue/1199): Linux overlayfs actually allows listxattr, - // but not any other xattr syscalls. For now we just reject all of them. - return nil, syserror.ENOTSUP + + return fs.listXattr(ctx, d, size) } -// GetxattrAt implements vfs.FilesystemImpl.GetxattrAt. -func (fs *filesystem) GetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.GetxattrOptions) (string, error) { +func (fs *filesystem) listXattr(ctx context.Context, d *dentry, size uint64) ([]string, error) { + vfsObj := d.fs.vfsfs.VirtualFilesystem() + top := d.topLayer() + names, err := vfsObj.ListXattrAt(ctx, fs.creds, &vfs.PathOperation{Root: top, Start: top}, size) + if err != nil { + return nil, err + } + + // Filter out all overlay attributes. + n := 0 + for _, name := range names { + if !isOverlayXattr(name) { + names[n] = name + n++ + } + } + return names[:n], err +} + +// GetXattrAt implements vfs.FilesystemImpl.GetXattrAt. +func (fs *filesystem) GetXattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.GetXattrOptions) (string, error) { var ds *[]*dentry fs.renameMu.RLock() defer fs.renameMuRUnlockAndCheckDrop(ctx, &ds) - _, err := fs.resolveLocked(ctx, rp, &ds) + d, err := fs.resolveLocked(ctx, rp, &ds) if err != nil { return "", err } - return "", syserror.ENOTSUP + + return fs.getXattr(ctx, d, rp.Credentials(), &opts) } -// SetxattrAt implements vfs.FilesystemImpl.SetxattrAt. -func (fs *filesystem) SetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.SetxattrOptions) error { +func (fs *filesystem) getXattr(ctx context.Context, d *dentry, creds *auth.Credentials, opts *vfs.GetXattrOptions) (string, error) { + if err := d.checkXattrPermissions(creds, opts.Name, vfs.MayRead); err != nil { + return "", err + } + + // Return EOPNOTSUPP when fetching an overlay attribute. + // See fs/overlayfs/super.c:ovl_own_xattr_get(). + if isOverlayXattr(opts.Name) { + return "", syserror.EOPNOTSUPP + } + + // Analogous to fs/overlayfs/super.c:ovl_other_xattr_get(). + vfsObj := d.fs.vfsfs.VirtualFilesystem() + top := d.topLayer() + return vfsObj.GetXattrAt(ctx, fs.creds, &vfs.PathOperation{Root: top, Start: top}, opts) +} + +// SetXattrAt implements vfs.FilesystemImpl.SetXattrAt. +func (fs *filesystem) SetXattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.SetXattrOptions) error { var ds *[]*dentry fs.renameMu.RLock() - defer fs.renameMuRUnlockAndCheckDrop(ctx, &ds) - _, err := fs.resolveLocked(ctx, rp, &ds) + d, err := fs.resolveLocked(ctx, rp, &ds) + if err != nil { + fs.renameMuRUnlockAndCheckDrop(ctx, &ds) + return err + } + + err = fs.setXattrLocked(ctx, d, rp.Mount(), rp.Credentials(), &opts) + fs.renameMuRUnlockAndCheckDrop(ctx, &ds) if err != nil { return err } - return syserror.ENOTSUP + + d.InotifyWithParent(ctx, linux.IN_ATTRIB, 0 /* cookie */, vfs.InodeEvent) + return nil +} + +// Precondition: fs.renameMu must be locked. +func (fs *filesystem) setXattrLocked(ctx context.Context, d *dentry, mnt *vfs.Mount, creds *auth.Credentials, opts *vfs.SetXattrOptions) error { + if err := d.checkXattrPermissions(creds, opts.Name, vfs.MayWrite); err != nil { + return err + } + + // Return EOPNOTSUPP when setting an overlay attribute. + // See fs/overlayfs/super.c:ovl_own_xattr_set(). + if isOverlayXattr(opts.Name) { + return syserror.EOPNOTSUPP + } + + // Analogous to fs/overlayfs/super.c:ovl_other_xattr_set(). + if err := mnt.CheckBeginWrite(); err != nil { + return err + } + defer mnt.EndWrite() + if err := d.copyUpLocked(ctx); err != nil { + return err + } + vfsObj := d.fs.vfsfs.VirtualFilesystem() + return vfsObj.SetXattrAt(ctx, fs.creds, &vfs.PathOperation{Root: d.upperVD, Start: d.upperVD}, opts) } -// RemovexattrAt implements vfs.FilesystemImpl.RemovexattrAt. -func (fs *filesystem) RemovexattrAt(ctx context.Context, rp *vfs.ResolvingPath, name string) error { +// RemoveXattrAt implements vfs.FilesystemImpl.RemoveXattrAt. +func (fs *filesystem) RemoveXattrAt(ctx context.Context, rp *vfs.ResolvingPath, name string) error { var ds *[]*dentry fs.renameMu.RLock() - defer fs.renameMuRUnlockAndCheckDrop(ctx, &ds) - _, err := fs.resolveLocked(ctx, rp, &ds) + d, err := fs.resolveLocked(ctx, rp, &ds) + if err != nil { + fs.renameMuRUnlockAndCheckDrop(ctx, &ds) + return err + } + + err = fs.removeXattrLocked(ctx, d, rp.Mount(), rp.Credentials(), name) + fs.renameMuRUnlockAndCheckDrop(ctx, &ds) if err != nil { return err } - return syserror.ENOTSUP + + d.InotifyWithParent(ctx, linux.IN_ATTRIB, 0 /* cookie */, vfs.InodeEvent) + return nil +} + +// Precondition: fs.renameMu must be locked. +func (fs *filesystem) removeXattrLocked(ctx context.Context, d *dentry, mnt *vfs.Mount, creds *auth.Credentials, name string) error { + if err := d.checkXattrPermissions(creds, name, vfs.MayWrite); err != nil { + return err + } + + // Like SetXattrAt, return EOPNOTSUPP when removing an overlay attribute. + // Linux passes the remove request to xattr_handler->set. + // See fs/xattr.c:vfs_removexattr(). + if isOverlayXattr(name) { + return syserror.EOPNOTSUPP + } + + if err := mnt.CheckBeginWrite(); err != nil { + return err + } + defer mnt.EndWrite() + if err := d.copyUpLocked(ctx); err != nil { + return err + } + vfsObj := d.fs.vfsfs.VirtualFilesystem() + return vfsObj.RemoveXattrAt(ctx, fs.creds, &vfs.PathOperation{Root: d.upperVD, Start: d.upperVD}, name) } // PrependPath implements vfs.FilesystemImpl.PrependPath. diff --git a/pkg/sentry/fsimpl/overlay/non_directory.go b/pkg/sentry/fsimpl/overlay/non_directory.go index 268b32537..853aee951 100644 --- a/pkg/sentry/fsimpl/overlay/non_directory.go +++ b/pkg/sentry/fsimpl/overlay/non_directory.go @@ -23,6 +23,7 @@ import ( "gvisor.dev/gvisor/pkg/sentry/memmap" "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/sync" + "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/usermem" ) @@ -38,6 +39,7 @@ func (d *dentry) readlink(ctx context.Context) (string, error) { }) } +// +stateify savable type nonDirectoryFD struct { fileDescription @@ -46,7 +48,7 @@ type nonDirectoryFD struct { // fileDescription.dentry().upperVD. cachedFlags is the last known value of // cachedFD.StatusFlags(). copiedUp, cachedFD, and cachedFlags are // protected by mu. - mu sync.Mutex + mu sync.Mutex `state:"nosave"` copiedUp bool cachedFD *vfs.FileDescription cachedFlags uint32 @@ -146,6 +148,16 @@ func (fd *nonDirectoryFD) Stat(ctx context.Context, opts vfs.StatOptions) (linux return stat, nil } +// Allocate implements vfs.FileDescriptionImpl.Allocate. +func (fd *nonDirectoryFD) Allocate(ctx context.Context, mode, offset, length uint64) error { + wrappedFD, err := fd.getCurrentFD(ctx) + if err != nil { + return err + } + defer wrappedFD.DecRef(ctx) + return wrappedFD.Allocate(ctx, mode, offset, length) +} + // SetStat implements vfs.FileDescriptionImpl.SetStat. func (fd *nonDirectoryFD) SetStat(ctx context.Context, opts vfs.SetStatOptions) error { d := fd.dentry() @@ -172,6 +184,9 @@ func (fd *nonDirectoryFD) SetStat(ctx context.Context, opts vfs.SetStatOptions) return err } d.updateAfterSetStatLocked(&opts) + if ev := vfs.InotifyEventFromStatMask(opts.Stat.Mask); ev != 0 { + d.InotifyWithParent(ctx, ev, 0, vfs.InodeEvent) + } return nil } @@ -256,10 +271,105 @@ func (fd *nonDirectoryFD) Sync(ctx context.Context) error { // ConfigureMMap implements vfs.FileDescriptionImpl.ConfigureMMap. func (fd *nonDirectoryFD) ConfigureMMap(ctx context.Context, opts *memmap.MMapOpts) error { - wrappedFD, err := fd.getCurrentFD(ctx) + if err := fd.ensureMappable(ctx, opts); err != nil { + return err + } + return vfs.GenericConfigureMMap(&fd.vfsfd, fd.dentry(), opts) +} + +// ensureMappable ensures that fd.dentry().wrappedMappable is not nil. +func (fd *nonDirectoryFD) ensureMappable(ctx context.Context, opts *memmap.MMapOpts) error { + d := fd.dentry() + + // Fast path if we already have a Mappable for the current top layer. + if atomic.LoadUint32(&d.isMappable) != 0 { + return nil + } + + // Only permit mmap of regular files, since other file types may have + // unpredictable behavior when mmapped (e.g. /dev/zero). + if atomic.LoadUint32(&d.mode)&linux.S_IFMT != linux.S_IFREG { + return syserror.ENODEV + } + + // Get a Mappable for the current top layer. + fd.mu.Lock() + defer fd.mu.Unlock() + d.copyMu.RLock() + defer d.copyMu.RUnlock() + if atomic.LoadUint32(&d.isMappable) != 0 { + return nil + } + wrappedFD, err := fd.currentFDLocked(ctx) if err != nil { return err } - defer wrappedFD.DecRef(ctx) - return wrappedFD.ConfigureMMap(ctx, opts) + if err := wrappedFD.ConfigureMMap(ctx, opts); err != nil { + return err + } + if opts.MappingIdentity != nil { + opts.MappingIdentity.DecRef(ctx) + opts.MappingIdentity = nil + } + // Use this Mappable for all mappings of this layer (unless we raced with + // another call to ensureMappable). + d.mapsMu.Lock() + defer d.mapsMu.Unlock() + d.dataMu.Lock() + defer d.dataMu.Unlock() + if d.wrappedMappable == nil { + d.wrappedMappable = opts.Mappable + atomic.StoreUint32(&d.isMappable, 1) + } + return nil +} + +// AddMapping implements memmap.Mappable.AddMapping. +func (d *dentry) AddMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64, writable bool) error { + d.mapsMu.Lock() + defer d.mapsMu.Unlock() + if err := d.wrappedMappable.AddMapping(ctx, ms, ar, offset, writable); err != nil { + return err + } + if !d.isCopiedUp() { + d.lowerMappings.AddMapping(ms, ar, offset, writable) + } + return nil +} + +// RemoveMapping implements memmap.Mappable.RemoveMapping. +func (d *dentry) RemoveMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64, writable bool) { + d.mapsMu.Lock() + defer d.mapsMu.Unlock() + d.wrappedMappable.RemoveMapping(ctx, ms, ar, offset, writable) + if !d.isCopiedUp() { + d.lowerMappings.RemoveMapping(ms, ar, offset, writable) + } +} + +// CopyMapping implements memmap.Mappable.CopyMapping. +func (d *dentry) CopyMapping(ctx context.Context, ms memmap.MappingSpace, srcAR, dstAR usermem.AddrRange, offset uint64, writable bool) error { + d.mapsMu.Lock() + defer d.mapsMu.Unlock() + if err := d.wrappedMappable.CopyMapping(ctx, ms, srcAR, dstAR, offset, writable); err != nil { + return err + } + if !d.isCopiedUp() { + d.lowerMappings.AddMapping(ms, dstAR, offset, writable) + } + return nil +} + +// Translate implements memmap.Mappable.Translate. +func (d *dentry) Translate(ctx context.Context, required, optional memmap.MappableRange, at usermem.AccessType) ([]memmap.Translation, error) { + d.dataMu.RLock() + defer d.dataMu.RUnlock() + return d.wrappedMappable.Translate(ctx, required, optional, at) +} + +// InvalidateUnsavable implements memmap.Mappable.InvalidateUnsavable. +func (d *dentry) InvalidateUnsavable(ctx context.Context) error { + d.mapsMu.Lock() + defer d.mapsMu.Unlock() + return d.wrappedMappable.InvalidateUnsavable(ctx) } diff --git a/pkg/sentry/fsimpl/overlay/overlay.go b/pkg/sentry/fsimpl/overlay/overlay.go index 00562667f..dfbccd05f 100644 --- a/pkg/sentry/fsimpl/overlay/overlay.go +++ b/pkg/sentry/fsimpl/overlay/overlay.go @@ -22,6 +22,10 @@ // filesystem.renameMu // dentry.dirMu // dentry.copyMu +// *** "memmap.Mappable locks" below this point +// dentry.mapsMu +// *** "memmap.Mappable locks taken by Translate" below this point +// dentry.dataMu // // Locking dentry.dirMu in multiple dentries requires that parent dentries are // locked before child dentries, and that filesystem.renameMu is locked to @@ -37,6 +41,7 @@ import ( "gvisor.dev/gvisor/pkg/fspath" fslock "gvisor.dev/gvisor/pkg/sentry/fs/lock" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" + "gvisor.dev/gvisor/pkg/sentry/memmap" "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/syserror" @@ -46,6 +51,8 @@ import ( const Name = "overlay" // FilesystemType implements vfs.FilesystemType. +// +// +stateify savable type FilesystemType struct{} // Name implements vfs.FilesystemType.Name. @@ -55,6 +62,8 @@ func (FilesystemType) Name() string { // FilesystemOptions may be passed as vfs.GetFilesystemOptions.InternalData to // FilesystemType.GetFilesystem. +// +// +stateify savable type FilesystemOptions struct { // Callers passing FilesystemOptions to // overlay.FilesystemType.GetFilesystem() are responsible for ensuring that @@ -71,6 +80,8 @@ type FilesystemOptions struct { } // filesystem implements vfs.FilesystemImpl. +// +// +stateify savable type filesystem struct { vfsfs vfs.Filesystem @@ -93,7 +104,7 @@ type filesystem struct { // renameMu synchronizes renaming with non-renaming operations in order to // ensure consistent lock ordering between dentry.dirMu in different // dentries. - renameMu sync.RWMutex + renameMu sync.RWMutex `state:"nosave"` // lastDirIno is the last inode number assigned to a directory. lastDirIno // is accessed using atomic memory operations. @@ -106,16 +117,16 @@ func (fstype FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt fsoptsRaw := opts.InternalData fsopts, haveFSOpts := fsoptsRaw.(FilesystemOptions) if fsoptsRaw != nil && !haveFSOpts { - ctx.Warningf("overlay.FilesystemType.GetFilesystem: GetFilesystemOptions.InternalData has type %T, wanted overlay.FilesystemOptions or nil", fsoptsRaw) + ctx.Infof("overlay.FilesystemType.GetFilesystem: GetFilesystemOptions.InternalData has type %T, wanted overlay.FilesystemOptions or nil", fsoptsRaw) return nil, nil, syserror.EINVAL } if haveFSOpts { if len(fsopts.LowerRoots) == 0 { - ctx.Warningf("overlay.FilesystemType.GetFilesystem: LowerRoots must be non-empty") + ctx.Infof("overlay.FilesystemType.GetFilesystem: LowerRoots must be non-empty") return nil, nil, syserror.EINVAL } if len(fsopts.LowerRoots) < 2 && !fsopts.UpperRoot.Ok() { - ctx.Warningf("overlay.FilesystemType.GetFilesystem: at least two LowerRoots are required when UpperRoot is unspecified") + ctx.Infof("overlay.FilesystemType.GetFilesystem: at least two LowerRoots are required when UpperRoot is unspecified") return nil, nil, syserror.EINVAL } // We don't enforce a maximum number of lower layers when not @@ -132,7 +143,7 @@ func (fstype FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt delete(mopts, "workdir") upperPath := fspath.Parse(upperPathname) if !upperPath.Absolute { - ctx.Warningf("overlay.FilesystemType.GetFilesystem: upperdir %q must be absolute", upperPathname) + ctx.Infof("overlay.FilesystemType.GetFilesystem: upperdir %q must be absolute", upperPathname) return nil, nil, syserror.EINVAL } upperRoot, err := vfsObj.GetDentryAt(ctx, creds, &vfs.PathOperation{ @@ -144,13 +155,13 @@ func (fstype FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt CheckSearchable: true, }) if err != nil { - ctx.Warningf("overlay.FilesystemType.GetFilesystem: failed to resolve upperdir %q: %v", upperPathname, err) + ctx.Infof("overlay.FilesystemType.GetFilesystem: failed to resolve upperdir %q: %v", upperPathname, err) return nil, nil, err } defer upperRoot.DecRef(ctx) privateUpperRoot, err := clonePrivateMount(vfsObj, upperRoot, false /* forceReadOnly */) if err != nil { - ctx.Warningf("overlay.FilesystemType.GetFilesystem: failed to make private bind mount of upperdir %q: %v", upperPathname, err) + ctx.Infof("overlay.FilesystemType.GetFilesystem: failed to make private bind mount of upperdir %q: %v", upperPathname, err) return nil, nil, err } defer privateUpperRoot.DecRef(ctx) @@ -158,24 +169,24 @@ func (fstype FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt } lowerPathnamesStr, ok := mopts["lowerdir"] if !ok { - ctx.Warningf("overlay.FilesystemType.GetFilesystem: missing required option lowerdir") + ctx.Infof("overlay.FilesystemType.GetFilesystem: missing required option lowerdir") return nil, nil, syserror.EINVAL } delete(mopts, "lowerdir") lowerPathnames := strings.Split(lowerPathnamesStr, ":") const maxLowerLayers = 500 // Linux: fs/overlay/super.c:OVL_MAX_STACK if len(lowerPathnames) < 2 && !fsopts.UpperRoot.Ok() { - ctx.Warningf("overlay.FilesystemType.GetFilesystem: at least two lowerdirs are required when upperdir is unspecified") + ctx.Infof("overlay.FilesystemType.GetFilesystem: at least two lowerdirs are required when upperdir is unspecified") return nil, nil, syserror.EINVAL } if len(lowerPathnames) > maxLowerLayers { - ctx.Warningf("overlay.FilesystemType.GetFilesystem: %d lowerdirs specified, maximum %d", len(lowerPathnames), maxLowerLayers) + ctx.Infof("overlay.FilesystemType.GetFilesystem: %d lowerdirs specified, maximum %d", len(lowerPathnames), maxLowerLayers) return nil, nil, syserror.EINVAL } for _, lowerPathname := range lowerPathnames { lowerPath := fspath.Parse(lowerPathname) if !lowerPath.Absolute { - ctx.Warningf("overlay.FilesystemType.GetFilesystem: lowerdir %q must be absolute", lowerPathname) + ctx.Infof("overlay.FilesystemType.GetFilesystem: lowerdir %q must be absolute", lowerPathname) return nil, nil, syserror.EINVAL } lowerRoot, err := vfsObj.GetDentryAt(ctx, creds, &vfs.PathOperation{ @@ -187,13 +198,13 @@ func (fstype FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt CheckSearchable: true, }) if err != nil { - ctx.Warningf("overlay.FilesystemType.GetFilesystem: failed to resolve lowerdir %q: %v", lowerPathname, err) + ctx.Infof("overlay.FilesystemType.GetFilesystem: failed to resolve lowerdir %q: %v", lowerPathname, err) return nil, nil, err } defer lowerRoot.DecRef(ctx) privateLowerRoot, err := clonePrivateMount(vfsObj, lowerRoot, true /* forceReadOnly */) if err != nil { - ctx.Warningf("overlay.FilesystemType.GetFilesystem: failed to make private bind mount of lowerdir %q: %v", lowerPathname, err) + ctx.Infof("overlay.FilesystemType.GetFilesystem: failed to make private bind mount of lowerdir %q: %v", lowerPathname, err) return nil, nil, err } defer privateLowerRoot.DecRef(ctx) @@ -201,7 +212,7 @@ func (fstype FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt } } if len(mopts) != 0 { - ctx.Warningf("overlay.FilesystemType.GetFilesystem: unused options: %v", mopts) + ctx.Infof("overlay.FilesystemType.GetFilesystem: unused options: %v", mopts) return nil, nil, syserror.EINVAL } @@ -274,7 +285,7 @@ func (fstype FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt return nil, nil, syserror.EREMOTE } if isWhiteout(&rootStat) { - ctx.Warningf("overlay.FilesystemType.GetFilesystem: filesystem root is a whiteout") + ctx.Infof("overlay.FilesystemType.GetFilesystem: filesystem root is a whiteout") root.destroyLocked(ctx) fs.vfsfs.DecRef(ctx) return nil, nil, syserror.EINVAL @@ -362,6 +373,8 @@ func (fs *filesystem) newDirIno() uint64 { } // dentry implements vfs.DentryImpl. +// +// +stateify savable type dentry struct { vfsd vfs.Dentry @@ -394,7 +407,7 @@ type dentry struct { // and dirents (if not nil) is a cache of dirents as returned by // directoryFDs representing this directory. children is protected by // dirMu. - dirMu sync.Mutex + dirMu sync.Mutex `state:"nosave"` children map[string]*dentry dirents []vfs.Dirent @@ -404,7 +417,7 @@ type dentry struct { // If !upperVD.Ok(), it can transition to a valid vfs.VirtualDentry (i.e. // be copied up) with copyMu locked for writing; otherwise, it is // immutable. lowerVDs is always immutable. - copyMu sync.RWMutex + copyMu sync.RWMutex `state:"nosave"` upperVD vfs.VirtualDentry lowerVDs []vfs.VirtualDentry @@ -419,7 +432,43 @@ type dentry struct { devMinor uint32 ino uint64 + // If this dentry represents a regular file, then: + // + // - mapsMu is used to synchronize between copy-up and memmap.Mappable + // methods on dentry preceding mm.MemoryManager.activeMu in the lock order. + // + // - dataMu is used to synchronize between copy-up and + // dentry.(memmap.Mappable).Translate. + // + // - lowerMappings tracks memory mappings of the file. lowerMappings is + // used to invalidate mappings of the lower layer when the file is copied + // up to ensure that they remain coherent with subsequent writes to the + // file. (Note that, as of this writing, Linux overlayfs does not do this; + // this feature is a gVisor extension.) lowerMappings is protected by + // mapsMu. + // + // - If this dentry is copied-up, then wrappedMappable is the Mappable + // obtained from a call to the current top layer's + // FileDescription.ConfigureMMap(). Once wrappedMappable becomes non-nil + // (from a call to nonDirectoryFD.ensureMappable()), it cannot become nil. + // wrappedMappable is protected by mapsMu and dataMu. + // + // - isMappable is non-zero iff wrappedMappable is non-nil. isMappable is + // accessed using atomic memory operations. + mapsMu sync.Mutex + lowerMappings memmap.MappingSet + dataMu sync.RWMutex + wrappedMappable memmap.Mappable + isMappable uint32 + locks vfs.FileLocks + + // watches is the set of inotify watches on the file repesented by this dentry. + // + // Note that hard links to the same file will not share the same set of + // watches, due to the fact that we do not have inode structures in this + // overlay implementation. + watches vfs.Watches } // newDentry creates a new dentry. The dentry initially has no references; it @@ -479,6 +528,14 @@ func (d *dentry) checkDropLocked(ctx context.Context) { if atomic.LoadInt64(&d.refs) != 0 { return } + + // Make sure that we do not lose watches on dentries that have not been + // deleted. Note that overlayfs never calls VFS.InvalidateDentry(), so + // d.vfsd.IsDead() indicates that d was deleted. + if !d.vfsd.IsDead() && d.watches.Size() > 0 { + return + } + // Refs is still zero; destroy it. d.destroyLocked(ctx) return @@ -507,6 +564,8 @@ func (d *dentry) destroyLocked(ctx context.Context) { lowerVD.DecRef(ctx) } + d.watches.HandleDeletion(ctx) + if d.parent != nil { d.parent.dirMu.Lock() if !d.vfsd.IsDead() { @@ -525,19 +584,36 @@ func (d *dentry) destroyLocked(ctx context.Context) { // InotifyWithParent implements vfs.DentryImpl.InotifyWithParent. func (d *dentry) InotifyWithParent(ctx context.Context, events uint32, cookie uint32, et vfs.EventType) { - // TODO(gvisor.dev/issue/1479): Implement inotify. + if d.isDir() { + events |= linux.IN_ISDIR + } + + // overlayfs never calls VFS.InvalidateDentry(), so d.vfsd.IsDead() indicates + // that d was deleted. + deleted := d.vfsd.IsDead() + + d.fs.renameMu.RLock() + // The ordering below is important, Linux always notifies the parent first. + if d.parent != nil { + d.parent.watches.Notify(ctx, d.name, events, cookie, et, deleted) + } + d.watches.Notify(ctx, "", events, cookie, et, deleted) + d.fs.renameMu.RUnlock() } // Watches implements vfs.DentryImpl.Watches. func (d *dentry) Watches() *vfs.Watches { - // TODO(gvisor.dev/issue/1479): Implement inotify. - return nil + return &d.watches } // OnZeroWatches implements vfs.DentryImpl.OnZeroWatches. -// -// TODO(gvisor.dev/issue/1479): Implement inotify. -func (d *dentry) OnZeroWatches(context.Context) {} +func (d *dentry) OnZeroWatches(ctx context.Context) { + if atomic.LoadInt64(&d.refs) == 0 { + d.fs.renameMu.Lock() + d.checkDropLocked(ctx) + d.fs.renameMu.Unlock() + } +} // iterLayers invokes yield on each layer comprising d, from top to bottom. If // any call to yield returns false, iterLayer stops iteration. @@ -570,6 +646,16 @@ func (d *dentry) checkPermissions(creds *auth.Credentials, ats vfs.AccessTypes) return vfs.GenericCheckPermissions(creds, ats, linux.FileMode(atomic.LoadUint32(&d.mode)), auth.KUID(atomic.LoadUint32(&d.uid)), auth.KGID(atomic.LoadUint32(&d.gid))) } +func (d *dentry) checkXattrPermissions(creds *auth.Credentials, name string, ats vfs.AccessTypes) error { + mode := linux.FileMode(atomic.LoadUint32(&d.mode)) + kuid := auth.KUID(atomic.LoadUint32(&d.uid)) + kgid := auth.KGID(atomic.LoadUint32(&d.gid)) + if err := vfs.GenericCheckPermissions(creds, ats, mode, kuid, kgid); err != nil { + return err + } + return vfs.CheckXattrPermissions(creds, ats, mode, kuid, name) +} + // statInternalMask is the set of stat fields that is set by // dentry.statInternalTo(). const statInternalMask = linux.STATX_TYPE | linux.STATX_MODE | linux.STATX_UID | linux.STATX_GID | linux.STATX_INO @@ -608,6 +694,8 @@ func (d *dentry) updateAfterSetStatLocked(opts *vfs.SetStatOptions) { // fileDescription is embedded by overlay implementations of // vfs.FileDescriptionImpl. +// +// +stateify savable type fileDescription struct { vfsfd vfs.FileDescription vfs.FileDescriptionDefaultImpl @@ -622,6 +710,48 @@ func (fd *fileDescription) dentry() *dentry { return fd.vfsfd.Dentry().Impl().(*dentry) } +// ListXattr implements vfs.FileDescriptionImpl.ListXattr. +func (fd *fileDescription) ListXattr(ctx context.Context, size uint64) ([]string, error) { + return fd.filesystem().listXattr(ctx, fd.dentry(), size) +} + +// GetXattr implements vfs.FileDescriptionImpl.GetXattr. +func (fd *fileDescription) GetXattr(ctx context.Context, opts vfs.GetXattrOptions) (string, error) { + return fd.filesystem().getXattr(ctx, fd.dentry(), auth.CredentialsFromContext(ctx), &opts) +} + +// SetXattr implements vfs.FileDescriptionImpl.SetXattr. +func (fd *fileDescription) SetXattr(ctx context.Context, opts vfs.SetXattrOptions) error { + fs := fd.filesystem() + d := fd.dentry() + + fs.renameMu.RLock() + err := fs.setXattrLocked(ctx, d, fd.vfsfd.Mount(), auth.CredentialsFromContext(ctx), &opts) + fs.renameMu.RUnlock() + if err != nil { + return err + } + + d.InotifyWithParent(ctx, linux.IN_ATTRIB, 0, vfs.InodeEvent) + return nil +} + +// RemoveXattr implements vfs.FileDescriptionImpl.RemoveXattr. +func (fd *fileDescription) RemoveXattr(ctx context.Context, name string) error { + fs := fd.filesystem() + d := fd.dentry() + + fs.renameMu.RLock() + err := fs.removeXattrLocked(ctx, d, fd.vfsfd.Mount(), auth.CredentialsFromContext(ctx), name) + fs.renameMu.RUnlock() + if err != nil { + return err + } + + d.InotifyWithParent(ctx, linux.IN_ATTRIB, 0, vfs.InodeEvent) + return nil +} + // LockPOSIX implements vfs.FileDescriptionImpl.LockPOSIX. func (fd *fileDescription) LockPOSIX(ctx context.Context, uid fslock.UniqueID, t fslock.LockType, start, length uint64, whence int16, block fslock.Blocker) error { return fd.Locks().LockPOSIX(ctx, &fd.vfsfd, uid, t, start, length, whence, block) diff --git a/pkg/sentry/fsimpl/pipefs/pipefs.go b/pkg/sentry/fsimpl/pipefs/pipefs.go index 7053ad6db..4e2da4810 100644 --- a/pkg/sentry/fsimpl/pipefs/pipefs.go +++ b/pkg/sentry/fsimpl/pipefs/pipefs.go @@ -31,6 +31,7 @@ import ( "gvisor.dev/gvisor/pkg/usermem" ) +// +stateify savable type filesystemType struct{} // Name implements vfs.FilesystemType.Name. @@ -43,6 +44,7 @@ func (filesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.VirtualFile panic("pipefs.filesystemType.GetFilesystem should never be called") } +// +stateify savable type filesystem struct { kernfs.Filesystem @@ -76,6 +78,8 @@ func (fs *filesystem) PrependPath(ctx context.Context, vfsroot, vd vfs.VirtualDe } // inode implements kernfs.Inode. +// +// +stateify savable type inode struct { kernfs.InodeNotDirectory kernfs.InodeNotSymlink @@ -144,8 +148,8 @@ func (i *inode) SetStat(ctx context.Context, vfsfs *vfs.Filesystem, creds *auth. } // Open implements kernfs.Inode.Open. -func (i *inode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { - return i.pipe.Open(ctx, rp.Mount(), vfsd, opts.Flags, &i.locks) +func (i *inode) Open(ctx context.Context, rp *vfs.ResolvingPath, d *kernfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { + return i.pipe.Open(ctx, rp.Mount(), d.VFSDentry(), opts.Flags, &i.locks) } // StatFS implements kernfs.Inode.StatFS. diff --git a/pkg/sentry/fsimpl/proc/BUILD b/pkg/sentry/fsimpl/proc/BUILD index a45b44440..2e086e34c 100644 --- a/pkg/sentry/fsimpl/proc/BUILD +++ b/pkg/sentry/fsimpl/proc/BUILD @@ -100,6 +100,7 @@ go_library( "//pkg/sync", "//pkg/syserror", "//pkg/tcpip/header", + "//pkg/tcpip/network/ipv4", "//pkg/usermem", ], ) diff --git a/pkg/sentry/fsimpl/proc/filesystem.go b/pkg/sentry/fsimpl/proc/filesystem.go index 03b5941b9..05d7948ea 100644 --- a/pkg/sentry/fsimpl/proc/filesystem.go +++ b/pkg/sentry/fsimpl/proc/filesystem.go @@ -41,6 +41,7 @@ func (FilesystemType) Name() string { return Name } +// +stateify savable type filesystem struct { kernfs.Filesystem @@ -84,6 +85,8 @@ func (fs *filesystem) Release(ctx context.Context) { // dynamicInode is an overfitted interface for common Inodes with // dynamicByteSource types used in procfs. +// +// +stateify savable type dynamicInode interface { kernfs.Inode vfs.DynamicBytesSource @@ -99,6 +102,7 @@ func (fs *filesystem) newDentry(creds *auth.Credentials, ino uint64, perm linux. return d } +// +stateify savable type staticFile struct { kernfs.DynamicBytesFile vfs.StaticData @@ -118,10 +122,13 @@ func newStaticDir(creds *auth.Credentials, devMajor, devMinor uint32, ino uint64 // InternalData contains internal data passed in to the procfs mount via // vfs.GetFilesystemOptions.InternalData. +// +// +stateify savable type InternalData struct { Cgroups map[string]string } +// +stateify savable type implStatFS struct{} // StatFS implements kernfs.Inode.StatFS. diff --git a/pkg/sentry/fsimpl/proc/subtasks.go b/pkg/sentry/fsimpl/proc/subtasks.go index d57d94dbc..47ecd941c 100644 --- a/pkg/sentry/fsimpl/proc/subtasks.go +++ b/pkg/sentry/fsimpl/proc/subtasks.go @@ -68,8 +68,8 @@ func (fs *filesystem) newSubtasks(task *kernel.Task, pidns *kernel.PIDNamespace, return dentry } -// Lookup implements kernfs.inodeDynamicLookup. -func (i *subtasksInode) Lookup(ctx context.Context, name string) (*vfs.Dentry, error) { +// Lookup implements kernfs.inodeDynamicLookup.Lookup. +func (i *subtasksInode) Lookup(ctx context.Context, name string) (*kernfs.Dentry, error) { tid, err := strconv.ParseUint(name, 10, 32) if err != nil { return nil, syserror.ENOENT @@ -82,12 +82,10 @@ func (i *subtasksInode) Lookup(ctx context.Context, name string) (*vfs.Dentry, e if subTask.ThreadGroup() != i.task.ThreadGroup() { return nil, syserror.ENOENT } - - subTaskDentry := i.fs.newTaskInode(subTask, i.pidns, false, i.cgroupControllers) - return subTaskDentry.VFSDentry(), nil + return i.fs.newTaskInode(subTask, i.pidns, false, i.cgroupControllers), nil } -// IterDirents implements kernfs.inodeDynamicLookup. +// IterDirents implements kernfs.inodeDynamicLookup.IterDirents. func (i *subtasksInode) IterDirents(ctx context.Context, cb vfs.IterDirentsCallback, offset, relOffset int64) (int64, error) { tasks := i.task.ThreadGroup().MemberIDs(i.pidns) if len(tasks) == 0 { @@ -118,6 +116,7 @@ func (i *subtasksInode) IterDirents(ctx context.Context, cb vfs.IterDirentsCallb return offset, nil } +// +stateify savable type subtasksFD struct { kernfs.GenericDirectoryFD @@ -155,21 +154,21 @@ func (fd *subtasksFD) SetStat(ctx context.Context, opts vfs.SetStatOptions) erro return fd.GenericDirectoryFD.SetStat(ctx, opts) } -// Open implements kernfs.Inode. -func (i *subtasksInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { +// Open implements kernfs.Inode.Open. +func (i *subtasksInode) Open(ctx context.Context, rp *vfs.ResolvingPath, d *kernfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { fd := &subtasksFD{task: i.task} if err := fd.Init(&i.OrderedChildren, &i.locks, &opts, kernfs.GenericDirectoryFDOptions{ SeekEnd: kernfs.SeekEndZero, }); err != nil { return nil, err } - if err := fd.VFSFileDescription().Init(fd, opts.Flags, rp.Mount(), vfsd, &vfs.FileDescriptionOptions{}); err != nil { + if err := fd.VFSFileDescription().Init(fd, opts.Flags, rp.Mount(), d.VFSDentry(), &vfs.FileDescriptionOptions{}); err != nil { return nil, err } return fd.VFSFileDescription(), nil } -// Stat implements kernfs.Inode. +// Stat implements kernfs.Inode.Stat. func (i *subtasksInode) Stat(ctx context.Context, vsfs *vfs.Filesystem, opts vfs.StatOptions) (linux.Statx, error) { stat, err := i.InodeAttrs.Stat(ctx, vsfs, opts) if err != nil { @@ -181,12 +180,12 @@ func (i *subtasksInode) Stat(ctx context.Context, vsfs *vfs.Filesystem, opts vfs return stat, nil } -// SetStat implements Inode.SetStat not allowing inode attributes to be changed. +// SetStat implements kernfs.Inode.SetStat not allowing inode attributes to be changed. func (*subtasksInode) SetStat(context.Context, *vfs.Filesystem, *auth.Credentials, vfs.SetStatOptions) error { return syserror.EPERM } -// DecRef implements kernfs.Inode. +// DecRef implements kernfs.Inode.DecRef. func (i *subtasksInode) DecRef(context.Context) { i.subtasksInodeRefs.DecRef(i.Destroy) } diff --git a/pkg/sentry/fsimpl/proc/task.go b/pkg/sentry/fsimpl/proc/task.go index dbdb5d929..a7cd6f57e 100644 --- a/pkg/sentry/fsimpl/proc/task.go +++ b/pkg/sentry/fsimpl/proc/task.go @@ -53,6 +53,7 @@ func (fs *filesystem) newTaskInode(task *kernel.Task, pidns *kernel.PIDNamespace "auxv": fs.newTaskOwnedFile(task, fs.NextIno(), 0444, &auxvData{task: task}), "cmdline": fs.newTaskOwnedFile(task, fs.NextIno(), 0444, &cmdlineData{task: task, arg: cmdlineDataArg}), "comm": fs.newComm(task, fs.NextIno(), 0444), + "cwd": fs.newCwdSymlink(task, fs.NextIno()), "environ": fs.newTaskOwnedFile(task, fs.NextIno(), 0444, &cmdlineData{task: task, arg: environDataArg}), "exe": fs.newExeSymlink(task, fs.NextIno()), "fd": fs.newFDDirInode(task), @@ -106,9 +107,9 @@ func (i *taskInode) Valid(ctx context.Context) bool { return i.task.ExitState() != kernel.TaskExitDead } -// Open implements kernfs.Inode. -func (i *taskInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { - fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &i.OrderedChildren, &i.locks, &opts, kernfs.GenericDirectoryFDOptions{ +// Open implements kernfs.Inode.Open. +func (i *taskInode) Open(ctx context.Context, rp *vfs.ResolvingPath, d *kernfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { + fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), d, &i.OrderedChildren, &i.locks, &opts, kernfs.GenericDirectoryFDOptions{ SeekEnd: kernfs.SeekEndZero, }) if err != nil { @@ -117,18 +118,20 @@ func (i *taskInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.D return fd.VFSFileDescription(), nil } -// SetStat implements Inode.SetStat not allowing inode attributes to be changed. +// SetStat implements kernfs.Inode.SetStat not allowing inode attributes to be changed. func (*taskInode) SetStat(context.Context, *vfs.Filesystem, *auth.Credentials, vfs.SetStatOptions) error { return syserror.EPERM } -// DecRef implements kernfs.Inode. +// DecRef implements kernfs.Inode.DecRef. func (i *taskInode) DecRef(context.Context) { i.taskInodeRefs.DecRef(i.Destroy) } // taskOwnedInode implements kernfs.Inode and overrides inode owner with task // effective user and group. +// +// +stateify savable type taskOwnedInode struct { kernfs.Inode @@ -168,7 +171,7 @@ func (fs *filesystem) newTaskOwnedDir(task *kernel.Task, ino uint64, perm linux. return d } -// Stat implements kernfs.Inode. +// Stat implements kernfs.Inode.Stat. func (i *taskOwnedInode) Stat(ctx context.Context, fs *vfs.Filesystem, opts vfs.StatOptions) (linux.Statx, error) { stat, err := i.Inode.Stat(ctx, fs, opts) if err != nil { @@ -186,7 +189,7 @@ func (i *taskOwnedInode) Stat(ctx context.Context, fs *vfs.Filesystem, opts vfs. return stat, nil } -// CheckPermissions implements kernfs.Inode. +// CheckPermissions implements kernfs.Inode.CheckPermissions. func (i *taskOwnedInode) CheckPermissions(_ context.Context, creds *auth.Credentials, ats vfs.AccessTypes) error { mode := i.Mode() uid, gid := i.getOwner(mode) diff --git a/pkg/sentry/fsimpl/proc/task_fds.go b/pkg/sentry/fsimpl/proc/task_fds.go index 3f0d78461..0866cea2b 100644 --- a/pkg/sentry/fsimpl/proc/task_fds.go +++ b/pkg/sentry/fsimpl/proc/task_fds.go @@ -51,6 +51,7 @@ func taskFDExists(ctx context.Context, t *kernel.Task, fd int32) bool { return true } +// +stateify savable type fdDir struct { locks vfs.FileLocks @@ -62,7 +63,7 @@ type fdDir struct { produceSymlink bool } -// IterDirents implements kernfs.inodeDynamicLookup. +// IterDirents implements kernfs.inodeDynamicLookup.IterDirents. func (i *fdDir) IterDirents(ctx context.Context, cb vfs.IterDirentsCallback, offset, relOffset int64) (int64, error) { var fds []int32 i.task.WithMuLocked(func(t *kernel.Task) { @@ -86,14 +87,19 @@ func (i *fdDir) IterDirents(ctx context.Context, cb vfs.IterDirentsCallback, off Name: strconv.FormatUint(uint64(fd), 10), Type: typ, Ino: i.fs.NextIno(), - NextOff: offset + 1, + NextOff: int64(fd) + 3, } if err := cb.Handle(dirent); err != nil { - return offset, err + // Getdents should iterate correctly despite mutation + // of fds, so we return the next fd to serialize plus + // 2 (which accounts for the "." and ".." tracked by + // kernfs) as the offset. + return int64(fd) + 2, err } - offset++ } - return offset, nil + // We serialized them all. Next offset should be higher than last + // serialized fd. + return int64(fds[len(fds)-1]) + 3, nil } // fdDirInode represents the inode for /proc/[pid]/fd directory. @@ -130,8 +136,8 @@ func (fs *filesystem) newFDDirInode(task *kernel.Task) *kernfs.Dentry { return dentry } -// Lookup implements kernfs.inodeDynamicLookup. -func (i *fdDirInode) Lookup(ctx context.Context, name string) (*vfs.Dentry, error) { +// Lookup implements kernfs.inodeDynamicLookup.Lookup. +func (i *fdDirInode) Lookup(ctx context.Context, name string) (*kernfs.Dentry, error) { fdInt, err := strconv.ParseInt(name, 10, 32) if err != nil { return nil, syserror.ENOENT @@ -140,13 +146,12 @@ func (i *fdDirInode) Lookup(ctx context.Context, name string) (*vfs.Dentry, erro if !taskFDExists(ctx, i.task, fd) { return nil, syserror.ENOENT } - taskDentry := i.fs.newFDSymlink(i.task, fd, i.fs.NextIno()) - return taskDentry.VFSDentry(), nil + return i.fs.newFDSymlink(i.task, fd, i.fs.NextIno()), nil } -// Open implements kernfs.Inode. -func (i *fdDirInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { - fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &i.OrderedChildren, &i.locks, &opts, kernfs.GenericDirectoryFDOptions{ +// Open implements kernfs.Inode.Open. +func (i *fdDirInode) Open(ctx context.Context, rp *vfs.ResolvingPath, d *kernfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { + fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), d, &i.OrderedChildren, &i.locks, &opts, kernfs.GenericDirectoryFDOptions{ SeekEnd: kernfs.SeekEndZero, }) if err != nil { @@ -155,7 +160,7 @@ func (i *fdDirInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs. return fd.VFSFileDescription(), nil } -// CheckPermissions implements kernfs.Inode. +// CheckPermissions implements kernfs.Inode.CheckPermissions. // // This is to match Linux, which uses a special permission handler to guarantee // that a process can still access /proc/self/fd after it has executed @@ -177,7 +182,7 @@ func (i *fdDirInode) CheckPermissions(ctx context.Context, creds *auth.Credentia return err } -// DecRef implements kernfs.Inode. +// DecRef implements kernfs.Inode.DecRef. func (i *fdDirInode) DecRef(context.Context) { i.fdDirInodeRefs.DecRef(i.Destroy) } @@ -209,7 +214,7 @@ func (fs *filesystem) newFDSymlink(task *kernel.Task, fd int32, ino uint64) *ker return d } -func (s *fdSymlink) Readlink(ctx context.Context) (string, error) { +func (s *fdSymlink) Readlink(ctx context.Context, _ *vfs.Mount) (string, error) { file, _ := getTaskFD(s.task, s.fd) if file == nil { return "", syserror.ENOENT @@ -264,8 +269,8 @@ func (fs *filesystem) newFDInfoDirInode(task *kernel.Task) *kernfs.Dentry { return dentry } -// Lookup implements kernfs.inodeDynamicLookup. -func (i *fdInfoDirInode) Lookup(ctx context.Context, name string) (*vfs.Dentry, error) { +// Lookup implements kernfs.inodeDynamicLookup.Lookup. +func (i *fdInfoDirInode) Lookup(ctx context.Context, name string) (*kernfs.Dentry, error) { fdInt, err := strconv.ParseInt(name, 10, 32) if err != nil { return nil, syserror.ENOENT @@ -278,13 +283,12 @@ func (i *fdInfoDirInode) Lookup(ctx context.Context, name string) (*vfs.Dentry, task: i.task, fd: fd, } - dentry := i.fs.newTaskOwnedFile(i.task, i.fs.NextIno(), 0444, data) - return dentry.VFSDentry(), nil + return i.fs.newTaskOwnedFile(i.task, i.fs.NextIno(), 0444, data), nil } -// Open implements kernfs.Inode. -func (i *fdInfoDirInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { - fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &i.OrderedChildren, &i.locks, &opts, kernfs.GenericDirectoryFDOptions{ +// Open implements kernfs.Inode.Open. +func (i *fdInfoDirInode) Open(ctx context.Context, rp *vfs.ResolvingPath, d *kernfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { + fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), d, &i.OrderedChildren, &i.locks, &opts, kernfs.GenericDirectoryFDOptions{ SeekEnd: kernfs.SeekEndZero, }) if err != nil { @@ -293,7 +297,7 @@ func (i *fdInfoDirInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd * return fd.VFSFileDescription(), nil } -// DecRef implements kernfs.Inode. +// DecRef implements kernfs.Inode.DecRef. func (i *fdInfoDirInode) DecRef(context.Context) { i.fdInfoDirInodeRefs.DecRef(i.Destroy) } diff --git a/pkg/sentry/fsimpl/proc/task_files.go b/pkg/sentry/fsimpl/proc/task_files.go index 356036b9b..3fbf081a6 100644 --- a/pkg/sentry/fsimpl/proc/task_files.go +++ b/pkg/sentry/fsimpl/proc/task_files.go @@ -543,7 +543,7 @@ func (s *statusData) Generate(ctx context.Context, buf *bytes.Buffer) error { var vss, rss, data uint64 s.task.WithMuLocked(func(t *kernel.Task) { if fdTable := t.FDTable(); fdTable != nil { - fds = fdTable.Size() + fds = fdTable.CurrentMaxFDs() } if mm := t.MemoryManager(); mm != nil { vss = mm.VirtualMemorySize() @@ -667,20 +667,24 @@ func (fs *filesystem) newExeSymlink(task *kernel.Task, ino uint64) *kernfs.Dentr return d } -// Readlink implements kernfs.Inode. -func (s *exeSymlink) Readlink(ctx context.Context) (string, error) { - if !kernel.ContextCanTrace(ctx, s.task, false) { - return "", syserror.EACCES - } - - // Pull out the executable for /proc/[pid]/exe. - exec, err := s.executable() +// Readlink implements kernfs.Inode.Readlink. +func (s *exeSymlink) Readlink(ctx context.Context, _ *vfs.Mount) (string, error) { + exec, _, err := s.Getlink(ctx, nil) if err != nil { return "", err } defer exec.DecRef(ctx) - return exec.PathnameWithDeleted(ctx), nil + root := vfs.RootFromContext(ctx) + if !root.Ok() { + // It could have raced with process deletion. + return "", syserror.ESRCH + } + defer root.DecRef(ctx) + + vfsObj := exec.Mount().Filesystem().VirtualFilesystem() + name, _ := vfsObj.PathnameWithDeleted(ctx, root, exec) + return name, nil } // Getlink implements kernfs.Inode.Getlink. @@ -688,23 +692,12 @@ func (s *exeSymlink) Getlink(ctx context.Context, _ *vfs.Mount) (vfs.VirtualDent if !kernel.ContextCanTrace(ctx, s.task, false) { return vfs.VirtualDentry{}, "", syserror.EACCES } - - exec, err := s.executable() - if err != nil { - return vfs.VirtualDentry{}, "", err - } - defer exec.DecRef(ctx) - - vd := exec.(*fsbridge.VFSFile).FileDescription().VirtualDentry() - vd.IncRef() - return vd, "", nil -} - -func (s *exeSymlink) executable() (file fsbridge.File, err error) { if err := checkTaskState(s.task); err != nil { - return nil, err + return vfs.VirtualDentry{}, "", err } + var err error + var exec fsbridge.File s.task.WithMuLocked(func(t *kernel.Task) { mm := t.MemoryManager() if mm == nil { @@ -715,12 +708,78 @@ func (s *exeSymlink) executable() (file fsbridge.File, err error) { // The MemoryManager may be destroyed, in which case // MemoryManager.destroy will simply set the executable to nil // (with locks held). - file = mm.Executable() - if file == nil { + exec = mm.Executable() + if exec == nil { err = syserror.ESRCH } }) - return + if err != nil { + return vfs.VirtualDentry{}, "", err + } + defer exec.DecRef(ctx) + + vd := exec.(*fsbridge.VFSFile).FileDescription().VirtualDentry() + vd.IncRef() + return vd, "", nil +} + +// cwdSymlink is an symlink for the /proc/[pid]/cwd file. +// +// +stateify savable +type cwdSymlink struct { + implStatFS + kernfs.InodeAttrs + kernfs.InodeNoopRefCount + kernfs.InodeSymlink + + task *kernel.Task +} + +var _ kernfs.Inode = (*cwdSymlink)(nil) + +func (fs *filesystem) newCwdSymlink(task *kernel.Task, ino uint64) *kernfs.Dentry { + inode := &cwdSymlink{task: task} + inode.Init(task.Credentials(), linux.UNNAMED_MAJOR, fs.devMinor, ino, linux.ModeSymlink|0777) + + d := &kernfs.Dentry{} + d.Init(inode) + return d +} + +// Readlink implements kernfs.Inode.Readlink. +func (s *cwdSymlink) Readlink(ctx context.Context, _ *vfs.Mount) (string, error) { + cwd, _, err := s.Getlink(ctx, nil) + if err != nil { + return "", err + } + defer cwd.DecRef(ctx) + + root := vfs.RootFromContext(ctx) + if !root.Ok() { + // It could have raced with process deletion. + return "", syserror.ESRCH + } + defer root.DecRef(ctx) + + vfsObj := cwd.Mount().Filesystem().VirtualFilesystem() + name, _ := vfsObj.PathnameWithDeleted(ctx, root, cwd) + return name, nil +} + +// Getlink implements kernfs.Inode.Getlink. +func (s *cwdSymlink) Getlink(ctx context.Context, _ *vfs.Mount) (vfs.VirtualDentry, string, error) { + if !kernel.ContextCanTrace(ctx, s.task, false) { + return vfs.VirtualDentry{}, "", syserror.EACCES + } + if err := checkTaskState(s.task); err != nil { + return vfs.VirtualDentry{}, "", err + } + cwd := s.task.FSContext().WorkingDirectoryVFS2() + if !cwd.Ok() { + // It could have raced with process deletion. + return vfs.VirtualDentry{}, "", syserror.ESRCH + } + return cwd, "", nil } // mountInfoData is used to implement /proc/[pid]/mountinfo. @@ -785,6 +844,7 @@ func (i *mountsData) Generate(ctx context.Context, buf *bytes.Buffer) error { return nil } +// +stateify savable type namespaceSymlink struct { kernfs.StaticSymlink @@ -807,15 +867,15 @@ func (fs *filesystem) newNamespaceSymlink(task *kernel.Task, ino uint64, ns stri return d } -// Readlink implements Inode. -func (s *namespaceSymlink) Readlink(ctx context.Context) (string, error) { +// Readlink implements kernfs.Inode.Readlink. +func (s *namespaceSymlink) Readlink(ctx context.Context, mnt *vfs.Mount) (string, error) { if err := checkTaskState(s.task); err != nil { return "", err } - return s.StaticSymlink.Readlink(ctx) + return s.StaticSymlink.Readlink(ctx, mnt) } -// Getlink implements Inode.Getlink. +// Getlink implements kernfs.Inode.Getlink. func (s *namespaceSymlink) Getlink(ctx context.Context, mnt *vfs.Mount) (vfs.VirtualDentry, string, error) { if err := checkTaskState(s.task); err != nil { return vfs.VirtualDentry{}, "", err @@ -832,6 +892,8 @@ func (s *namespaceSymlink) Getlink(ctx context.Context, mnt *vfs.Mount) (vfs.Vir // namespaceInode is a synthetic inode created to represent a namespace in // /proc/[pid]/ns/*. +// +// +stateify savable type namespaceInode struct { implStatFS kernfs.InodeAttrs @@ -852,12 +914,12 @@ func (i *namespaceInode) Init(creds *auth.Credentials, devMajor, devMinor uint32 i.InodeAttrs.Init(creds, devMajor, devMinor, ino, linux.ModeRegular|perm) } -// Open implements Inode.Open. -func (i *namespaceInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { +// Open implements kernfs.Inode.Open. +func (i *namespaceInode) Open(ctx context.Context, rp *vfs.ResolvingPath, d *kernfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { fd := &namespaceFD{inode: i} i.IncRef() fd.LockFD.Init(&i.locks) - if err := fd.vfsfd.Init(fd, opts.Flags, rp.Mount(), vfsd, &vfs.FileDescriptionOptions{}); err != nil { + if err := fd.vfsfd.Init(fd, opts.Flags, rp.Mount(), d.VFSDentry(), &vfs.FileDescriptionOptions{}); err != nil { return nil, err } return &fd.vfsfd, nil @@ -865,6 +927,8 @@ func (i *namespaceInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd * // namespace FD is a synthetic file that represents a namespace in // /proc/[pid]/ns/*. +// +// +stateify savable type namespaceFD struct { vfs.FileDescriptionDefaultImpl vfs.LockFD @@ -875,20 +939,20 @@ type namespaceFD struct { var _ vfs.FileDescriptionImpl = (*namespaceFD)(nil) -// Stat implements FileDescriptionImpl. +// Stat implements vfs.FileDescriptionImpl.Stat. func (fd *namespaceFD) Stat(ctx context.Context, opts vfs.StatOptions) (linux.Statx, error) { vfs := fd.vfsfd.VirtualDentry().Mount().Filesystem() return fd.inode.Stat(ctx, vfs, opts) } -// SetStat implements FileDescriptionImpl. +// SetStat implements vfs.FileDescriptionImpl.SetStat. func (fd *namespaceFD) SetStat(ctx context.Context, opts vfs.SetStatOptions) error { vfs := fd.vfsfd.VirtualDentry().Mount().Filesystem() creds := auth.CredentialsFromContext(ctx) return fd.inode.SetStat(ctx, vfs, creds, opts) } -// Release implements FileDescriptionImpl. +// Release implements vfs.FileDescriptionImpl.Release. func (fd *namespaceFD) Release(ctx context.Context) { fd.inode.DecRef(ctx) } diff --git a/pkg/sentry/fsimpl/proc/task_net.go b/pkg/sentry/fsimpl/proc/task_net.go index 4e69782c7..e7f748655 100644 --- a/pkg/sentry/fsimpl/proc/task_net.go +++ b/pkg/sentry/fsimpl/proc/task_net.go @@ -616,6 +616,7 @@ type netSnmpData struct { var _ dynamicInode = (*netSnmpData)(nil) +// +stateify savable type snmpLine struct { prefix string header string @@ -660,7 +661,7 @@ func sprintSlice(s []uint64) string { return r[1 : len(r)-1] // Remove "[]" introduced by fmt of slice. } -// Generate implements vfs.DynamicBytesSource. +// Generate implements vfs.DynamicBytesSource.Generate. func (d *netSnmpData) Generate(ctx context.Context, buf *bytes.Buffer) error { types := []interface{}{ &inet.StatSNMPIP{}, @@ -709,7 +710,7 @@ type netRouteData struct { var _ dynamicInode = (*netRouteData)(nil) -// Generate implements vfs.DynamicBytesSource. +// Generate implements vfs.DynamicBytesSource.Generate. // See Linux's net/ipv4/fib_trie.c:fib_route_seq_show. func (d *netRouteData) Generate(ctx context.Context, buf *bytes.Buffer) error { fmt.Fprintf(buf, "%-127s\n", "Iface\tDestination\tGateway\tFlags\tRefCnt\tUse\tMetric\tMask\tMTU\tWindow\tIRTT") @@ -773,7 +774,7 @@ type netStatData struct { var _ dynamicInode = (*netStatData)(nil) -// Generate implements vfs.DynamicBytesSource. +// Generate implements vfs.DynamicBytesSource.Generate. // See Linux's net/ipv4/fib_trie.c:fib_route_seq_show. func (d *netStatData) Generate(ctx context.Context, buf *bytes.Buffer) error { buf.WriteString("TcpExt: SyncookiesSent SyncookiesRecv SyncookiesFailed " + diff --git a/pkg/sentry/fsimpl/proc/tasks.go b/pkg/sentry/fsimpl/proc/tasks.go index 3ea00ab87..d8f5dd509 100644 --- a/pkg/sentry/fsimpl/proc/tasks.go +++ b/pkg/sentry/fsimpl/proc/tasks.go @@ -52,8 +52,8 @@ type tasksInode struct { // '/proc/self' and '/proc/thread-self' have custom directory offsets in // Linux. So handle them outside of OrderedChildren. - selfSymlink *vfs.Dentry - threadSelfSymlink *vfs.Dentry + selfSymlink *kernfs.Dentry + threadSelfSymlink *kernfs.Dentry // cgroupControllers is a map of controller name to directory in the // cgroup hierarchy. These controllers are immutable and will be listed @@ -81,8 +81,8 @@ func (fs *filesystem) newTasksInode(k *kernel.Kernel, pidns *kernel.PIDNamespace inode := &tasksInode{ pidns: pidns, fs: fs, - selfSymlink: fs.newSelfSymlink(root, fs.NextIno(), pidns).VFSDentry(), - threadSelfSymlink: fs.newThreadSelfSymlink(root, fs.NextIno(), pidns).VFSDentry(), + selfSymlink: fs.newSelfSymlink(root, fs.NextIno(), pidns), + threadSelfSymlink: fs.newThreadSelfSymlink(root, fs.NextIno(), pidns), cgroupControllers: cgroupControllers, } inode.InodeAttrs.Init(root, linux.UNNAMED_MAJOR, fs.devMinor, fs.NextIno(), linux.ModeDirectory|0555) @@ -98,8 +98,8 @@ func (fs *filesystem) newTasksInode(k *kernel.Kernel, pidns *kernel.PIDNamespace return inode, dentry } -// Lookup implements kernfs.inodeDynamicLookup. -func (i *tasksInode) Lookup(ctx context.Context, name string) (*vfs.Dentry, error) { +// Lookup implements kernfs.inodeDynamicLookup.Lookup. +func (i *tasksInode) Lookup(ctx context.Context, name string) (*kernfs.Dentry, error) { // Try to lookup a corresponding task. tid, err := strconv.ParseUint(name, 10, 64) if err != nil { @@ -118,11 +118,10 @@ func (i *tasksInode) Lookup(ctx context.Context, name string) (*vfs.Dentry, erro return nil, syserror.ENOENT } - taskDentry := i.fs.newTaskInode(task, i.pidns, true, i.cgroupControllers) - return taskDentry.VFSDentry(), nil + return i.fs.newTaskInode(task, i.pidns, true, i.cgroupControllers), nil } -// IterDirents implements kernfs.inodeDynamicLookup. +// IterDirents implements kernfs.inodeDynamicLookup.IterDirents. func (i *tasksInode) IterDirents(ctx context.Context, cb vfs.IterDirentsCallback, offset, _ int64) (int64, error) { // fs/proc/internal.h: #define FIRST_PROCESS_ENTRY 256 const FIRST_PROCESS_ENTRY = 256 @@ -200,9 +199,9 @@ func (i *tasksInode) IterDirents(ctx context.Context, cb vfs.IterDirentsCallback return maxTaskID, nil } -// Open implements kernfs.Inode. -func (i *tasksInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { - fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &i.OrderedChildren, &i.locks, &opts, kernfs.GenericDirectoryFDOptions{ +// Open implements kernfs.Inode.Open. +func (i *tasksInode) Open(ctx context.Context, rp *vfs.ResolvingPath, d *kernfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { + fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), d, &i.OrderedChildren, &i.locks, &opts, kernfs.GenericDirectoryFDOptions{ SeekEnd: kernfs.SeekEndZero, }) if err != nil { @@ -229,7 +228,7 @@ func (i *tasksInode) Stat(ctx context.Context, vsfs *vfs.Filesystem, opts vfs.St return stat, nil } -// DecRef implements kernfs.Inode. +// DecRef implements kernfs.Inode.DecRef. func (i *tasksInode) DecRef(context.Context) { i.tasksInodeRefs.DecRef(i.Destroy) } @@ -237,6 +236,8 @@ func (i *tasksInode) DecRef(context.Context) { // staticFileSetStat implements a special static file that allows inode // attributes to be set. This is to support /proc files that are readonly, but // allow attributes to be set. +// +// +stateify savable type staticFileSetStat struct { dynamicBytesFileSetAttr vfs.StaticData diff --git a/pkg/sentry/fsimpl/proc/tasks_files.go b/pkg/sentry/fsimpl/proc/tasks_files.go index 8c41729e4..f268c59b0 100644 --- a/pkg/sentry/fsimpl/proc/tasks_files.go +++ b/pkg/sentry/fsimpl/proc/tasks_files.go @@ -31,6 +31,7 @@ import ( "gvisor.dev/gvisor/pkg/usermem" ) +// +stateify savable type selfSymlink struct { implStatFS kernfs.InodeAttrs @@ -51,7 +52,7 @@ func (fs *filesystem) newSelfSymlink(creds *auth.Credentials, ino uint64, pidns return d } -func (s *selfSymlink) Readlink(ctx context.Context) (string, error) { +func (s *selfSymlink) Readlink(ctx context.Context, _ *vfs.Mount) (string, error) { t := kernel.TaskFromContext(ctx) if t == nil { // Who is reading this link? @@ -64,16 +65,17 @@ func (s *selfSymlink) Readlink(ctx context.Context) (string, error) { return strconv.FormatUint(uint64(tgid), 10), nil } -func (s *selfSymlink) Getlink(ctx context.Context, _ *vfs.Mount) (vfs.VirtualDentry, string, error) { - target, err := s.Readlink(ctx) +func (s *selfSymlink) Getlink(ctx context.Context, mnt *vfs.Mount) (vfs.VirtualDentry, string, error) { + target, err := s.Readlink(ctx, mnt) return vfs.VirtualDentry{}, target, err } -// SetStat implements Inode.SetStat not allowing inode attributes to be changed. +// SetStat implements kernfs.Inode.SetStat not allowing inode attributes to be changed. func (*selfSymlink) SetStat(context.Context, *vfs.Filesystem, *auth.Credentials, vfs.SetStatOptions) error { return syserror.EPERM } +// +stateify savable type threadSelfSymlink struct { implStatFS kernfs.InodeAttrs @@ -94,7 +96,7 @@ func (fs *filesystem) newThreadSelfSymlink(creds *auth.Credentials, ino uint64, return d } -func (s *threadSelfSymlink) Readlink(ctx context.Context) (string, error) { +func (s *threadSelfSymlink) Readlink(ctx context.Context, _ *vfs.Mount) (string, error) { t := kernel.TaskFromContext(ctx) if t == nil { // Who is reading this link? @@ -108,12 +110,12 @@ func (s *threadSelfSymlink) Readlink(ctx context.Context) (string, error) { return fmt.Sprintf("%d/task/%d", tgid, tid), nil } -func (s *threadSelfSymlink) Getlink(ctx context.Context, _ *vfs.Mount) (vfs.VirtualDentry, string, error) { - target, err := s.Readlink(ctx) +func (s *threadSelfSymlink) Getlink(ctx context.Context, mnt *vfs.Mount) (vfs.VirtualDentry, string, error) { + target, err := s.Readlink(ctx, mnt) return vfs.VirtualDentry{}, target, err } -// SetStat implements Inode.SetStat not allowing inode attributes to be changed. +// SetStat implements kernfs.Inode.SetStat not allowing inode attributes to be changed. func (*threadSelfSymlink) SetStat(context.Context, *vfs.Filesystem, *auth.Credentials, vfs.SetStatOptions) error { return syserror.EPERM } @@ -121,16 +123,20 @@ func (*threadSelfSymlink) SetStat(context.Context, *vfs.Filesystem, *auth.Creden // dynamicBytesFileSetAttr implements a special file that allows inode // attributes to be set. This is to support /proc files that are readonly, but // allow attributes to be set. +// +// +stateify savable type dynamicBytesFileSetAttr struct { kernfs.DynamicBytesFile } -// SetStat implements Inode.SetStat. +// SetStat implements kernfs.Inode.SetStat. func (d *dynamicBytesFileSetAttr) SetStat(ctx context.Context, fs *vfs.Filesystem, creds *auth.Credentials, opts vfs.SetStatOptions) error { return d.DynamicBytesFile.InodeAttrs.SetStat(ctx, fs, creds, opts) } // cpuStats contains the breakdown of CPU time for /proc/stat. +// +// +stateify savable type cpuStats struct { // user is time spent in userspace tasks with non-positive niceness. user uint64 diff --git a/pkg/sentry/fsimpl/proc/tasks_sys.go b/pkg/sentry/fsimpl/proc/tasks_sys.go index 038a194c7..3312b0418 100644 --- a/pkg/sentry/fsimpl/proc/tasks_sys.go +++ b/pkg/sentry/fsimpl/proc/tasks_sys.go @@ -27,9 +27,11 @@ import ( "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/syserror" + "gvisor.dev/gvisor/pkg/tcpip/network/ipv4" "gvisor.dev/gvisor/pkg/usermem" ) +// +stateify savable type tcpMemDir int const ( @@ -67,6 +69,7 @@ func (fs *filesystem) newSysNetDir(root *auth.Credentials, k *kernel.Kernel) *ke "tcp_rmem": fs.newDentry(root, fs.NextIno(), 0644, &tcpMemData{stack: stack, dir: tcpRMem}), "tcp_sack": fs.newDentry(root, fs.NextIno(), 0644, &tcpSackData{stack: stack}), "tcp_wmem": fs.newDentry(root, fs.NextIno(), 0644, &tcpMemData{stack: stack, dir: tcpWMem}), + "ip_forward": fs.newDentry(root, fs.NextIno(), 0444, &ipForwarding{stack: stack}), // The following files are simple stubs until they are implemented in // netstack, most of these files are configuration related. We use the @@ -174,7 +177,7 @@ type tcpSackData struct { var _ vfs.WritableDynamicBytesSource = (*tcpSackData)(nil) -// Generate implements vfs.DynamicBytesSource. +// Generate implements vfs.DynamicBytesSource.Generate. func (d *tcpSackData) Generate(ctx context.Context, buf *bytes.Buffer) error { if d.enabled == nil { sack, err := d.stack.TCPSACKEnabled() @@ -232,7 +235,7 @@ type tcpRecoveryData struct { var _ vfs.WritableDynamicBytesSource = (*tcpRecoveryData)(nil) -// Generate implements vfs.DynamicBytesSource. +// Generate implements vfs.DynamicBytesSource.Generate. func (d *tcpRecoveryData) Generate(ctx context.Context, buf *bytes.Buffer) error { recovery, err := d.stack.TCPRecovery() if err != nil { @@ -284,7 +287,7 @@ type tcpMemData struct { var _ vfs.WritableDynamicBytesSource = (*tcpMemData)(nil) -// Generate implements vfs.DynamicBytesSource. +// Generate implements vfs.DynamicBytesSource.Generate. func (d *tcpMemData) Generate(ctx context.Context, buf *bytes.Buffer) error { d.mu.Lock() defer d.mu.Unlock() @@ -354,3 +357,63 @@ func (d *tcpMemData) writeSizeLocked(size inet.TCPBufferSize) error { panic(fmt.Sprintf("unknown tcpMemFile type: %v", d.dir)) } } + +// ipForwarding implements vfs.WritableDynamicBytesSource for +// /proc/sys/net/ipv4/ip_forwarding. +// +// +stateify savable +type ipForwarding struct { + kernfs.DynamicBytesFile + + stack inet.Stack `state:"wait"` + enabled *bool +} + +var _ vfs.WritableDynamicBytesSource = (*ipForwarding)(nil) + +// Generate implements vfs.DynamicBytesSource.Generate. +func (ipf *ipForwarding) Generate(ctx context.Context, buf *bytes.Buffer) error { + if ipf.enabled == nil { + enabled := ipf.stack.Forwarding(ipv4.ProtocolNumber) + ipf.enabled = &enabled + } + + val := "0\n" + if *ipf.enabled { + // Technically, this is not quite compatible with Linux. Linux stores these + // as an integer, so if you write "2" into tcp_sack, you should get 2 back. + // Tough luck. + val = "1\n" + } + buf.WriteString(val) + + return nil +} + +// Write implements vfs.WritableDynamicBytesSource.Write. +func (ipf *ipForwarding) Write(ctx context.Context, src usermem.IOSequence, offset int64) (int64, error) { + if offset != 0 { + // No need to handle partial writes thus far. + return 0, syserror.EINVAL + } + if src.NumBytes() == 0 { + return 0, nil + } + + // Limit input size so as not to impact performance if input size is large. + src = src.TakeFirst(usermem.PageSize - 1) + + var v int32 + n, err := usermem.CopyInt32StringInVec(ctx, src.IO, src.Addrs, &v, src.Opts) + if err != nil { + return 0, err + } + if ipf.enabled == nil { + ipf.enabled = new(bool) + } + *ipf.enabled = v != 0 + if err := ipf.stack.SetForwarding(ipv4.ProtocolNumber, *ipf.enabled); err != nil { + return 0, err + } + return n, nil +} diff --git a/pkg/sentry/fsimpl/proc/tasks_sys_test.go b/pkg/sentry/fsimpl/proc/tasks_sys_test.go index be54897bb..6cee22823 100644 --- a/pkg/sentry/fsimpl/proc/tasks_sys_test.go +++ b/pkg/sentry/fsimpl/proc/tasks_sys_test.go @@ -20,8 +20,10 @@ import ( "testing" "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/sentry/contexttest" "gvisor.dev/gvisor/pkg/sentry/inet" + "gvisor.dev/gvisor/pkg/usermem" ) func newIPv6TestStack() *inet.TestStack { @@ -76,3 +78,72 @@ func TestIfinet6(t *testing.T) { t.Errorf("Got n.contents() = %v, want = %v", got, want) } } + +// TestIPForwarding tests the implementation of +// /proc/sys/net/ipv4/ip_forwarding +func TestConfigureIPForwarding(t *testing.T) { + ctx := context.Background() + s := inet.NewTestStack() + + var cases = []struct { + comment string + initial bool + str string + final bool + }{ + { + comment: `Forwarding is disabled; write 1 and enable forwarding`, + initial: false, + str: "1", + final: true, + }, + { + comment: `Forwarding is disabled; write 0 and disable forwarding`, + initial: false, + str: "0", + final: false, + }, + { + comment: `Forwarding is enabled; write 1 and enable forwarding`, + initial: true, + str: "1", + final: true, + }, + { + comment: `Forwarding is enabled; write 0 and disable forwarding`, + initial: true, + str: "0", + final: false, + }, + { + comment: `Forwarding is disabled; write 2404 and enable forwarding`, + initial: false, + str: "2404", + final: true, + }, + { + comment: `Forwarding is enabled; write 2404 and enable forwarding`, + initial: true, + str: "2404", + final: true, + }, + } + for _, c := range cases { + t.Run(c.comment, func(t *testing.T) { + s.IPForwarding = c.initial + + file := &ipForwarding{stack: s, enabled: &c.initial} + + // Write the values. + src := usermem.BytesIOSequence([]byte(c.str)) + if n, err := file.Write(ctx, src, 0); n != int64(len(c.str)) || err != nil { + t.Errorf("file.Write(ctx, nil, %q, 0) = (%d, %v); want (%d, nil)", c.str, n, err, len(c.str)) + } + + // Read the values from the stack and check them. + if got, want := s.IPForwarding, c.final; got != want { + t.Errorf("s.IPForwarding incorrect; got: %v, want: %v", got, want) + } + }) + } +} diff --git a/pkg/sentry/fsimpl/proc/tasks_test.go b/pkg/sentry/fsimpl/proc/tasks_test.go index d82b3d2f3..6975af5a7 100644 --- a/pkg/sentry/fsimpl/proc/tasks_test.go +++ b/pkg/sentry/fsimpl/proc/tasks_test.go @@ -67,6 +67,7 @@ var ( taskStaticFiles = map[string]testutil.DirentType{ "auxv": linux.DT_REG, "cgroup": linux.DT_REG, + "cwd": linux.DT_LNK, "cmdline": linux.DT_REG, "comm": linux.DT_REG, "environ": linux.DT_REG, @@ -104,7 +105,7 @@ func setup(t *testing.T) *testutil.System { AllowUserMount: true, }) - mntns, err := k.VFS().NewMountNamespace(ctx, creds, "", tmpfs.Name, &vfs.GetFilesystemOptions{}) + mntns, err := k.VFS().NewMountNamespace(ctx, creds, "", tmpfs.Name, &vfs.MountOptions{}) if err != nil { t.Fatalf("NewMountNamespace(): %v", err) } diff --git a/pkg/sentry/fsimpl/signalfd/signalfd.go b/pkg/sentry/fsimpl/signalfd/signalfd.go index 6297e1df4..bf11b425a 100644 --- a/pkg/sentry/fsimpl/signalfd/signalfd.go +++ b/pkg/sentry/fsimpl/signalfd/signalfd.go @@ -26,7 +26,9 @@ import ( "gvisor.dev/gvisor/pkg/waiter" ) -// SignalFileDescription implements FileDescriptionImpl for signal fds. +// SignalFileDescription implements vfs.FileDescriptionImpl for signal fds. +// +// +stateify savable type SignalFileDescription struct { vfsfd vfs.FileDescription vfs.FileDescriptionDefaultImpl @@ -43,7 +45,7 @@ type SignalFileDescription struct { target *kernel.Task // mu protects mask. - mu sync.Mutex + mu sync.Mutex `state:"nosave"` // mask is the signal mask. Protected by mu. mask linux.SignalSet @@ -83,7 +85,7 @@ func (sfd *SignalFileDescription) SetMask(mask linux.SignalSet) { sfd.mask = mask } -// Read implements FileDescriptionImpl.Read. +// Read implements vfs.FileDescriptionImpl.Read. func (sfd *SignalFileDescription) Read(ctx context.Context, dst usermem.IOSequence, _ vfs.ReadOptions) (int64, error) { // Attempt to dequeue relevant signals. info, err := sfd.target.Sigtimedwait(sfd.Mask(), 0) @@ -132,5 +134,5 @@ func (sfd *SignalFileDescription) EventUnregister(entry *waiter.Entry) { sfd.target.SignalUnregister(entry) } -// Release implements FileDescriptionImpl.Release() +// Release implements vfs.FileDescriptionImpl.Release. func (sfd *SignalFileDescription) Release(context.Context) {} diff --git a/pkg/sentry/fsimpl/sockfs/sockfs.go b/pkg/sentry/fsimpl/sockfs/sockfs.go index 94a998568..29e5371d6 100644 --- a/pkg/sentry/fsimpl/sockfs/sockfs.go +++ b/pkg/sentry/fsimpl/sockfs/sockfs.go @@ -28,14 +28,16 @@ import ( ) // filesystemType implements vfs.FilesystemType. +// +// +stateify savable type filesystemType struct{} -// GetFilesystem implements FilesystemType.GetFilesystem. +// GetFilesystem implements vfs.FilesystemType.GetFilesystem. func (fsType filesystemType) GetFilesystem(_ context.Context, vfsObj *vfs.VirtualFilesystem, _ *auth.Credentials, _ string, _ vfs.GetFilesystemOptions) (*vfs.Filesystem, *vfs.Dentry, error) { panic("sockfs.filesystemType.GetFilesystem should never be called") } -// Name implements FilesystemType.Name. +// Name implements vfs.FilesystemType.Name. // // Note that registering sockfs is unnecessary, except for the fact that it // will not show up under /proc/filesystems as a result. This is a very minor @@ -44,6 +46,7 @@ func (filesystemType) Name() string { return "sockfs" } +// +stateify savable type filesystem struct { kernfs.Filesystem @@ -80,6 +83,8 @@ func (fs *filesystem) PrependPath(ctx context.Context, vfsroot, vd vfs.VirtualDe } // inode implements kernfs.Inode. +// +// +stateify savable type inode struct { kernfs.InodeAttrs kernfs.InodeNoopRefCount @@ -88,7 +93,7 @@ type inode struct { } // Open implements kernfs.Inode.Open. -func (i *inode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { +func (i *inode) Open(ctx context.Context, rp *vfs.ResolvingPath, d *kernfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { return nil, syserror.ENXIO } diff --git a/pkg/sentry/fsimpl/sys/kcov.go b/pkg/sentry/fsimpl/sys/kcov.go index 73f3d3309..b75d70ae6 100644 --- a/pkg/sentry/fsimpl/sys/kcov.go +++ b/pkg/sentry/fsimpl/sys/kcov.go @@ -36,6 +36,8 @@ func (fs *filesystem) newKcovFile(ctx context.Context, creds *auth.Credentials) } // kcovInode implements kernfs.Inode. +// +// +stateify savable type kcovInode struct { kernfs.InodeAttrs kernfs.InodeNoopRefCount @@ -44,7 +46,7 @@ type kcovInode struct { implStatFS } -func (i *kcovInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { +func (i *kcovInode) Open(ctx context.Context, rp *vfs.ResolvingPath, d *kernfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { k := kernel.KernelFromContext(ctx) if k == nil { panic("KernelFromContext returned nil") @@ -54,7 +56,7 @@ func (i *kcovInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.D kcov: k.NewKcov(), } - if err := fd.vfsfd.Init(fd, opts.Flags, rp.Mount(), vfsd, &vfs.FileDescriptionOptions{ + if err := fd.vfsfd.Init(fd, opts.Flags, rp.Mount(), d.VFSDentry(), &vfs.FileDescriptionOptions{ DenyPRead: true, DenyPWrite: true, }); err != nil { @@ -63,6 +65,7 @@ func (i *kcovInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.D return &fd.vfsfd, nil } +// +stateify savable type kcovFD struct { vfs.FileDescriptionDefaultImpl vfs.NoLockFD diff --git a/pkg/sentry/fsimpl/sys/sys.go b/pkg/sentry/fsimpl/sys/sys.go index 39952d2d0..1568c581f 100644 --- a/pkg/sentry/fsimpl/sys/sys.go +++ b/pkg/sentry/fsimpl/sys/sys.go @@ -34,9 +34,13 @@ const Name = "sysfs" const defaultSysDirMode = linux.FileMode(0755) // FilesystemType implements vfs.FilesystemType. +// +// +stateify savable type FilesystemType struct{} // filesystem implements vfs.FilesystemImpl. +// +// +stateify savable type filesystem struct { kernfs.Filesystem @@ -117,6 +121,8 @@ func (fs *filesystem) Release(ctx context.Context) { } // dir implements kernfs.Inode. +// +// +stateify savable type dir struct { dirRefs kernfs.InodeAttrs @@ -148,8 +154,8 @@ func (*dir) SetStat(context.Context, *vfs.Filesystem, *auth.Credentials, vfs.Set } // Open implements kernfs.Inode.Open. -func (d *dir) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { - fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &d.OrderedChildren, &d.locks, &opts, kernfs.GenericDirectoryFDOptions{ +func (d *dir) Open(ctx context.Context, rp *vfs.ResolvingPath, kd *kernfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { + fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), kd, &d.OrderedChildren, &d.locks, &opts, kernfs.GenericDirectoryFDOptions{ SeekEnd: kernfs.SeekEndStaticEntries, }) if err != nil { @@ -169,6 +175,8 @@ func (d *dir) StatFS(ctx context.Context, fs *vfs.Filesystem) (linux.Statfs, err } // cpuFile implements kernfs.Inode. +// +// +stateify savable type cpuFile struct { implStatFS kernfs.DynamicBytesFile @@ -190,6 +198,7 @@ func (fs *filesystem) newCPUFile(creds *auth.Credentials, maxCores uint, mode li return d } +// +stateify savable type implStatFS struct{} // StatFS implements kernfs.Inode.StatFS. diff --git a/pkg/sentry/fsimpl/sys/sys_test.go b/pkg/sentry/fsimpl/sys/sys_test.go index 9fd38b295..0a0d914cc 100644 --- a/pkg/sentry/fsimpl/sys/sys_test.go +++ b/pkg/sentry/fsimpl/sys/sys_test.go @@ -38,7 +38,7 @@ func newTestSystem(t *testing.T) *testutil.System { AllowUserMount: true, }) - mns, err := k.VFS().NewMountNamespace(ctx, creds, "", sys.Name, &vfs.GetFilesystemOptions{}) + mns, err := k.VFS().NewMountNamespace(ctx, creds, "", sys.Name, &vfs.MountOptions{}) if err != nil { t.Fatalf("Failed to create new mount namespace: %v", err) } diff --git a/pkg/sentry/fsimpl/timerfd/timerfd.go b/pkg/sentry/fsimpl/timerfd/timerfd.go index 86beaa0a8..8853c8ad2 100644 --- a/pkg/sentry/fsimpl/timerfd/timerfd.go +++ b/pkg/sentry/fsimpl/timerfd/timerfd.go @@ -26,8 +26,10 @@ import ( "gvisor.dev/gvisor/pkg/waiter" ) -// TimerFileDescription implements FileDescriptionImpl for timer fds. It also +// TimerFileDescription implements vfs.FileDescriptionImpl for timer fds. It also // implements ktime.TimerListener. +// +// +stateify savable type TimerFileDescription struct { vfsfd vfs.FileDescription vfs.FileDescriptionDefaultImpl @@ -62,7 +64,7 @@ func New(ctx context.Context, vfsObj *vfs.VirtualFilesystem, clock ktime.Clock, return &tfd.vfsfd, nil } -// Read implements FileDescriptionImpl.Read. +// Read implements vfs.FileDescriptionImpl.Read. func (tfd *TimerFileDescription) Read(ctx context.Context, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) { const sizeofUint64 = 8 if dst.NumBytes() < sizeofUint64 { @@ -128,7 +130,7 @@ func (tfd *TimerFileDescription) ResumeTimer() { tfd.timer.Resume() } -// Release implements FileDescriptionImpl.Release() +// Release implements vfs.FileDescriptionImpl.Release. func (tfd *TimerFileDescription) Release(context.Context) { tfd.timer.Destroy() } diff --git a/pkg/sentry/fsimpl/tmpfs/benchmark_test.go b/pkg/sentry/fsimpl/tmpfs/benchmark_test.go index e5a4218e8..5209a17af 100644 --- a/pkg/sentry/fsimpl/tmpfs/benchmark_test.go +++ b/pkg/sentry/fsimpl/tmpfs/benchmark_test.go @@ -182,7 +182,7 @@ func BenchmarkVFS2TmpfsStat(b *testing.B) { vfsObj.MustRegisterFilesystemType("tmpfs", tmpfs.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{ AllowUserMount: true, }) - mntns, err := vfsObj.NewMountNamespace(ctx, creds, "", "tmpfs", &vfs.GetFilesystemOptions{}) + mntns, err := vfsObj.NewMountNamespace(ctx, creds, "", "tmpfs", &vfs.MountOptions{}) if err != nil { b.Fatalf("failed to create tmpfs root mount: %v", err) } @@ -376,7 +376,7 @@ func BenchmarkVFS2TmpfsMountStat(b *testing.B) { vfsObj.MustRegisterFilesystemType("tmpfs", tmpfs.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{ AllowUserMount: true, }) - mntns, err := vfsObj.NewMountNamespace(ctx, creds, "", "tmpfs", &vfs.GetFilesystemOptions{}) + mntns, err := vfsObj.NewMountNamespace(ctx, creds, "", "tmpfs", &vfs.MountOptions{}) if err != nil { b.Fatalf("failed to create tmpfs root mount: %v", err) } diff --git a/pkg/sentry/fsimpl/tmpfs/device_file.go b/pkg/sentry/fsimpl/tmpfs/device_file.go index ac54d420d..9129d35b7 100644 --- a/pkg/sentry/fsimpl/tmpfs/device_file.go +++ b/pkg/sentry/fsimpl/tmpfs/device_file.go @@ -22,6 +22,7 @@ import ( "gvisor.dev/gvisor/pkg/sentry/vfs" ) +// +stateify savable type deviceFile struct { inode inode kind vfs.DeviceKind diff --git a/pkg/sentry/fsimpl/tmpfs/directory.go b/pkg/sentry/fsimpl/tmpfs/directory.go index 070c75e68..e90669cf0 100644 --- a/pkg/sentry/fsimpl/tmpfs/directory.go +++ b/pkg/sentry/fsimpl/tmpfs/directory.go @@ -25,6 +25,7 @@ import ( "gvisor.dev/gvisor/pkg/syserror" ) +// +stateify savable type directory struct { // Since directories can't be hard-linked, each directory can only be // associated with a single dentry, which we can store in the directory @@ -44,7 +45,7 @@ type directory struct { // (with inode == nil) that represent the iteration position of // directoryFDs. childList is used to support directoryFD.IterDirents() // efficiently. childList is protected by iterMu. - iterMu sync.Mutex + iterMu sync.Mutex `state:"nosave"` childList dentryList } @@ -86,6 +87,7 @@ func (dir *directory) mayDelete(creds *auth.Credentials, child *dentry) error { return vfs.CheckDeleteSticky(creds, linux.FileMode(atomic.LoadUint32(&dir.inode.mode)), auth.KUID(atomic.LoadUint32(&child.inode.uid))) } +// +stateify savable type directoryFD struct { fileDescription vfs.DirectoryFileDescriptionDefaultImpl diff --git a/pkg/sentry/fsimpl/tmpfs/filesystem.go b/pkg/sentry/fsimpl/tmpfs/filesystem.go index e0de04e05..e39cd305b 100644 --- a/pkg/sentry/fsimpl/tmpfs/filesystem.go +++ b/pkg/sentry/fsimpl/tmpfs/filesystem.go @@ -673,11 +673,11 @@ func (fs *filesystem) SetStatAt(ctx context.Context, rp *vfs.ResolvingPath, opts fs.mu.RUnlock() return err } - if err := d.inode.setStat(ctx, rp.Credentials(), &opts); err != nil { - fs.mu.RUnlock() + err = d.inode.setStat(ctx, rp.Credentials(), &opts) + fs.mu.RUnlock() + if err != nil { return err } - fs.mu.RUnlock() if ev := vfs.InotifyEventFromStatMask(opts.Stat.Mask); ev != 0 { d.InotifyWithParent(ctx, ev, 0, vfs.InodeEvent) @@ -770,7 +770,7 @@ func (fs *filesystem) UnlinkAt(ctx context.Context, rp *vfs.ResolvingPath) error return nil } -// BoundEndpointAt implements FilesystemImpl.BoundEndpointAt. +// BoundEndpointAt implements vfs.FilesystemImpl.BoundEndpointAt. func (fs *filesystem) BoundEndpointAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.BoundEndpointOptions) (transport.BoundEndpoint, error) { fs.mu.RLock() defer fs.mu.RUnlock() @@ -792,59 +792,59 @@ func (fs *filesystem) BoundEndpointAt(ctx context.Context, rp *vfs.ResolvingPath } } -// ListxattrAt implements vfs.FilesystemImpl.ListxattrAt. -func (fs *filesystem) ListxattrAt(ctx context.Context, rp *vfs.ResolvingPath, size uint64) ([]string, error) { +// ListXattrAt implements vfs.FilesystemImpl.ListXattrAt. +func (fs *filesystem) ListXattrAt(ctx context.Context, rp *vfs.ResolvingPath, size uint64) ([]string, error) { fs.mu.RLock() defer fs.mu.RUnlock() d, err := resolveLocked(ctx, rp) if err != nil { return nil, err } - return d.inode.listxattr(size) + return d.inode.listXattr(size) } -// GetxattrAt implements vfs.FilesystemImpl.GetxattrAt. -func (fs *filesystem) GetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.GetxattrOptions) (string, error) { +// GetXattrAt implements vfs.FilesystemImpl.GetXattrAt. +func (fs *filesystem) GetXattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.GetXattrOptions) (string, error) { fs.mu.RLock() defer fs.mu.RUnlock() d, err := resolveLocked(ctx, rp) if err != nil { return "", err } - return d.inode.getxattr(rp.Credentials(), &opts) + return d.inode.getXattr(rp.Credentials(), &opts) } -// SetxattrAt implements vfs.FilesystemImpl.SetxattrAt. -func (fs *filesystem) SetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.SetxattrOptions) error { +// SetXattrAt implements vfs.FilesystemImpl.SetXattrAt. +func (fs *filesystem) SetXattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.SetXattrOptions) error { fs.mu.RLock() d, err := resolveLocked(ctx, rp) if err != nil { fs.mu.RUnlock() return err } - if err := d.inode.setxattr(rp.Credentials(), &opts); err != nil { - fs.mu.RUnlock() + err = d.inode.setXattr(rp.Credentials(), &opts) + fs.mu.RUnlock() + if err != nil { return err } - fs.mu.RUnlock() d.InotifyWithParent(ctx, linux.IN_ATTRIB, 0, vfs.InodeEvent) return nil } -// RemovexattrAt implements vfs.FilesystemImpl.RemovexattrAt. -func (fs *filesystem) RemovexattrAt(ctx context.Context, rp *vfs.ResolvingPath, name string) error { +// RemoveXattrAt implements vfs.FilesystemImpl.RemoveXattrAt. +func (fs *filesystem) RemoveXattrAt(ctx context.Context, rp *vfs.ResolvingPath, name string) error { fs.mu.RLock() d, err := resolveLocked(ctx, rp) if err != nil { fs.mu.RUnlock() return err } - if err := d.inode.removexattr(rp.Credentials(), name); err != nil { - fs.mu.RUnlock() + err = d.inode.removeXattr(rp.Credentials(), name) + fs.mu.RUnlock() + if err != nil { return err } - fs.mu.RUnlock() d.InotifyWithParent(ctx, linux.IN_ATTRIB, 0, vfs.InodeEvent) return nil @@ -865,8 +865,16 @@ func (fs *filesystem) PrependPath(ctx context.Context, vfsroot, vd vfs.VirtualDe } if d.parent == nil { if d.name != "" { - // This must be an anonymous memfd file. + // This file must have been created by + // newUnlinkedRegularFileDescription(). In Linux, + // mm/shmem.c:__shmem_file_setup() => + // fs/file_table.c:alloc_file_pseudo() sets the created + // dentry's dentry_operations to anon_ops, for which d_dname == + // simple_dname. fs/d_path.c:simple_dname() defines the + // dentry's pathname to be its name, prefixed with "/" and + // suffixed with " (deleted)". b.PrependComponent("/" + d.name) + b.AppendString(" (deleted)") return vfs.PrependPathSyntheticError{} } return vfs.PrependPathAtNonMountRootError{} diff --git a/pkg/sentry/fsimpl/tmpfs/named_pipe.go b/pkg/sentry/fsimpl/tmpfs/named_pipe.go index 5b0471ff4..d772db9e9 100644 --- a/pkg/sentry/fsimpl/tmpfs/named_pipe.go +++ b/pkg/sentry/fsimpl/tmpfs/named_pipe.go @@ -21,6 +21,7 @@ import ( "gvisor.dev/gvisor/pkg/usermem" ) +// +stateify savable type namedPipe struct { inode inode diff --git a/pkg/sentry/fsimpl/tmpfs/pipe_test.go b/pkg/sentry/fsimpl/tmpfs/pipe_test.go index ec2701d8b..be29a2363 100644 --- a/pkg/sentry/fsimpl/tmpfs/pipe_test.go +++ b/pkg/sentry/fsimpl/tmpfs/pipe_test.go @@ -158,7 +158,7 @@ func setup(t *testing.T) (context.Context, *auth.Credentials, *vfs.VirtualFilesy vfsObj.MustRegisterFilesystemType("tmpfs", FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{ AllowUserMount: true, }) - mntns, err := vfsObj.NewMountNamespace(ctx, creds, "", "tmpfs", &vfs.GetFilesystemOptions{}) + mntns, err := vfsObj.NewMountNamespace(ctx, creds, "", "tmpfs", &vfs.MountOptions{}) if err != nil { t.Fatalf("failed to create tmpfs root mount: %v", err) } diff --git a/pkg/sentry/fsimpl/tmpfs/regular_file.go b/pkg/sentry/fsimpl/tmpfs/regular_file.go index 0710b65db..a199eb33d 100644 --- a/pkg/sentry/fsimpl/tmpfs/regular_file.go +++ b/pkg/sentry/fsimpl/tmpfs/regular_file.go @@ -36,12 +36,18 @@ import ( ) // regularFile is a regular (=S_IFREG) tmpfs file. +// +// +stateify savable type regularFile struct { inode inode // memFile is a platform.File used to allocate pages to this regularFile. memFile *pgalloc.MemoryFile + // memoryUsageKind is the memory accounting category under which pages backing + // this regularFile's contents are accounted. + memoryUsageKind usage.MemoryKind + // mapsMu protects mappings. mapsMu sync.Mutex `state:"nosave"` @@ -62,7 +68,7 @@ type regularFile struct { writableMappingPages uint64 // dataMu protects the fields below. - dataMu sync.RWMutex + dataMu sync.RWMutex `state:"nosave"` // data maps offsets into the file to offsets into memFile that store // the file's data. @@ -86,14 +92,75 @@ type regularFile struct { func (fs *filesystem) newRegularFile(kuid auth.KUID, kgid auth.KGID, mode linux.FileMode) *inode { file := ®ularFile{ - memFile: fs.memFile, - seals: linux.F_SEAL_SEAL, + memFile: fs.memFile, + memoryUsageKind: usage.Tmpfs, + seals: linux.F_SEAL_SEAL, } file.inode.init(file, fs, kuid, kgid, linux.S_IFREG|mode) file.inode.nlink = 1 // from parent directory return &file.inode } +// newUnlinkedRegularFileDescription creates a regular file on the tmpfs +// filesystem represented by mount and returns an FD representing that file. +// The new file is not reachable by path traversal from any other file. +// +// newUnlinkedRegularFileDescription is analogous to Linux's +// mm/shmem.c:__shmem_file_setup(). +// +// Preconditions: mount must be a tmpfs mount. +func newUnlinkedRegularFileDescription(ctx context.Context, creds *auth.Credentials, mount *vfs.Mount, name string) (*regularFileFD, error) { + fs, ok := mount.Filesystem().Impl().(*filesystem) + if !ok { + panic("tmpfs.newUnlinkedRegularFileDescription() called with non-tmpfs mount") + } + + inode := fs.newRegularFile(creds.EffectiveKUID, creds.EffectiveKGID, 0777) + d := fs.newDentry(inode) + defer d.DecRef(ctx) + d.name = name + + fd := ®ularFileFD{} + fd.Init(&inode.locks) + flags := uint32(linux.O_RDWR) + if err := fd.vfsfd.Init(fd, flags, mount, &d.vfsd, &vfs.FileDescriptionOptions{}); err != nil { + return nil, err + } + return fd, nil +} + +// NewZeroFile creates a new regular file and file description as for +// mmap(MAP_SHARED | MAP_ANONYMOUS). The file has the given size and is +// initially (implicitly) filled with zeroes. +// +// Preconditions: mount must be a tmpfs mount. +func NewZeroFile(ctx context.Context, creds *auth.Credentials, mount *vfs.Mount, size uint64) (*vfs.FileDescription, error) { + // Compare mm/shmem.c:shmem_zero_setup(). + fd, err := newUnlinkedRegularFileDescription(ctx, creds, mount, "dev/zero") + if err != nil { + return nil, err + } + rf := fd.inode().impl.(*regularFile) + rf.memoryUsageKind = usage.Anonymous + rf.size = size + return &fd.vfsfd, err +} + +// NewMemfd creates a new regular file and file description as for +// memfd_create. +// +// Preconditions: mount must be a tmpfs mount. +func NewMemfd(ctx context.Context, creds *auth.Credentials, mount *vfs.Mount, allowSeals bool, name string) (*vfs.FileDescription, error) { + fd, err := newUnlinkedRegularFileDescription(ctx, creds, mount, name) + if err != nil { + return nil, err + } + if allowSeals { + fd.inode().impl.(*regularFile).seals = 0 + } + return &fd.vfsfd, nil +} + // truncate grows or shrinks the file to the given size. It returns true if the // file size was updated. func (rf *regularFile) truncate(newSize uint64) (bool, error) { @@ -226,7 +293,7 @@ func (rf *regularFile) Translate(ctx context.Context, required, optional memmap. optional.End = pgend } - cerr := rf.data.Fill(ctx, required, optional, rf.memFile, usage.Tmpfs, func(_ context.Context, dsts safemem.BlockSeq, _ uint64) (uint64, error) { + cerr := rf.data.Fill(ctx, required, optional, rf.memFile, rf.memoryUsageKind, func(_ context.Context, dsts safemem.BlockSeq, _ uint64) (uint64, error) { // Newly-allocated pages are zeroed, so we don't need to do anything. return dsts.NumBytes(), nil }) @@ -260,13 +327,14 @@ func (*regularFile) InvalidateUnsavable(context.Context) error { return nil } +// +stateify savable type regularFileFD struct { fileDescription // off is the file offset. off is accessed using atomic memory operations. // offMu serializes operations that may mutate off. off int64 - offMu sync.Mutex + offMu sync.Mutex `state:"nosave"` } // Release implements vfs.FileDescriptionImpl.Release. @@ -575,7 +643,7 @@ func (rw *regularFileReadWriter) WriteFromBlocks(srcs safemem.BlockSeq) (uint64, case gap.Ok(): // Allocate memory for the write. gapMR := gap.Range().Intersect(pgMR) - fr, err := rw.file.memFile.Allocate(gapMR.Length(), usage.Tmpfs) + fr, err := rw.file.memFile.Allocate(gapMR.Length(), rw.file.memoryUsageKind) if err != nil { retErr = err goto exitLoop diff --git a/pkg/sentry/fsimpl/tmpfs/socket_file.go b/pkg/sentry/fsimpl/tmpfs/socket_file.go index 3ed650474..5699d5975 100644 --- a/pkg/sentry/fsimpl/tmpfs/socket_file.go +++ b/pkg/sentry/fsimpl/tmpfs/socket_file.go @@ -21,6 +21,8 @@ import ( ) // socketFile is a socket (=S_IFSOCK) tmpfs file. +// +// +stateify savable type socketFile struct { inode inode ep transport.BoundEndpoint diff --git a/pkg/sentry/fsimpl/tmpfs/symlink.go b/pkg/sentry/fsimpl/tmpfs/symlink.go index b0de5fabe..a102a2ee2 100644 --- a/pkg/sentry/fsimpl/tmpfs/symlink.go +++ b/pkg/sentry/fsimpl/tmpfs/symlink.go @@ -19,6 +19,7 @@ import ( "gvisor.dev/gvisor/pkg/sentry/kernel/auth" ) +// +stateify savable type symlink struct { inode inode target string // immutable diff --git a/pkg/sentry/fsimpl/tmpfs/tmpfs.go b/pkg/sentry/fsimpl/tmpfs/tmpfs.go index c4cec4130..cefec8fde 100644 --- a/pkg/sentry/fsimpl/tmpfs/tmpfs.go +++ b/pkg/sentry/fsimpl/tmpfs/tmpfs.go @@ -51,9 +51,13 @@ import ( const Name = "tmpfs" // FilesystemType implements vfs.FilesystemType. +// +// +stateify savable type FilesystemType struct{} // filesystem implements vfs.FilesystemImpl. +// +// +stateify savable type filesystem struct { vfsfs vfs.Filesystem @@ -67,7 +71,7 @@ type filesystem struct { devMinor uint32 // mu serializes changes to the Dentry tree. - mu sync.RWMutex + mu sync.RWMutex `state:"nosave"` nextInoMinusOne uint64 // accessed using atomic memory operations } @@ -78,6 +82,8 @@ func (FilesystemType) Name() string { } // FilesystemOpts is used to pass configuration data to tmpfs. +// +// +stateify savable type FilesystemOpts struct { // RootFileType is the FileType of the filesystem root. Valid values // are: S_IFDIR, S_IFREG, and S_IFLNK. Defaults to S_IFDIR. @@ -221,6 +227,8 @@ var globalStatfs = linux.Statfs{ } // dentry implements vfs.DentryImpl. +// +// +stateify savable type dentry struct { vfsd vfs.Dentry @@ -300,6 +308,8 @@ func (d *dentry) Watches() *vfs.Watches { func (d *dentry) OnZeroWatches(context.Context) {} // inode represents a filesystem object. +// +// +stateify savable type inode struct { // fs is the owning filesystem. fs is immutable. fs *filesystem @@ -316,12 +326,12 @@ type inode struct { // Inode metadata. Writing multiple fields atomically requires holding // mu, othewise atomic operations can be used. - mu sync.Mutex - mode uint32 // file type and mode - nlink uint32 // protected by filesystem.mu instead of inode.mu - uid uint32 // auth.KUID, but stored as raw uint32 for sync/atomic - gid uint32 // auth.KGID, but ... - ino uint64 // immutable + mu sync.Mutex `state:"nosave"` + mode uint32 // file type and mode + nlink uint32 // protected by filesystem.mu instead of inode.mu + uid uint32 // auth.KUID, but stored as raw uint32 for sync/atomic + gid uint32 // auth.KGID, but ... + ino uint64 // immutable // Linux's tmpfs has no concept of btime. atime int64 // nanoseconds @@ -626,74 +636,50 @@ func (i *inode) touchCMtimeLocked() { atomic.StoreInt64(&i.ctime, now) } -func (i *inode) listxattr(size uint64) ([]string, error) { - return i.xattrs.Listxattr(size) +func (i *inode) listXattr(size uint64) ([]string, error) { + return i.xattrs.ListXattr(size) } -func (i *inode) getxattr(creds *auth.Credentials, opts *vfs.GetxattrOptions) (string, error) { +func (i *inode) getXattr(creds *auth.Credentials, opts *vfs.GetXattrOptions) (string, error) { if err := i.checkXattrPermissions(creds, opts.Name, vfs.MayRead); err != nil { return "", err } - return i.xattrs.Getxattr(opts) + return i.xattrs.GetXattr(opts) } -func (i *inode) setxattr(creds *auth.Credentials, opts *vfs.SetxattrOptions) error { +func (i *inode) setXattr(creds *auth.Credentials, opts *vfs.SetXattrOptions) error { if err := i.checkXattrPermissions(creds, opts.Name, vfs.MayWrite); err != nil { return err } - return i.xattrs.Setxattr(opts) + return i.xattrs.SetXattr(opts) } -func (i *inode) removexattr(creds *auth.Credentials, name string) error { +func (i *inode) removeXattr(creds *auth.Credentials, name string) error { if err := i.checkXattrPermissions(creds, name, vfs.MayWrite); err != nil { return err } - return i.xattrs.Removexattr(name) + return i.xattrs.RemoveXattr(name) } func (i *inode) checkXattrPermissions(creds *auth.Credentials, name string, ats vfs.AccessTypes) error { - switch { - case ats&vfs.MayRead == vfs.MayRead: - if err := i.checkPermissions(creds, vfs.MayRead); err != nil { - return err - } - case ats&vfs.MayWrite == vfs.MayWrite: - if err := i.checkPermissions(creds, vfs.MayWrite); err != nil { - return err - } - default: - panic(fmt.Sprintf("checkXattrPermissions called with impossible AccessTypes: %v", ats)) + // We currently only support extended attributes in the user.* and + // trusted.* namespaces. See b/148380782. + if !strings.HasPrefix(name, linux.XATTR_USER_PREFIX) && !strings.HasPrefix(name, linux.XATTR_TRUSTED_PREFIX) { + return syserror.EOPNOTSUPP } - - switch { - case strings.HasPrefix(name, linux.XATTR_TRUSTED_PREFIX): - // The trusted.* namespace can only be accessed by privileged - // users. - if creds.HasCapability(linux.CAP_SYS_ADMIN) { - return nil - } - if ats&vfs.MayWrite == vfs.MayWrite { - return syserror.EPERM - } - return syserror.ENODATA - case strings.HasPrefix(name, linux.XATTR_USER_PREFIX): - // Extended attributes in the user.* namespace are only - // supported for regular files and directories. - filetype := linux.S_IFMT & atomic.LoadUint32(&i.mode) - if filetype == linux.S_IFREG || filetype == linux.S_IFDIR { - return nil - } - if ats&vfs.MayWrite == vfs.MayWrite { - return syserror.EPERM - } - return syserror.ENODATA - + mode := linux.FileMode(atomic.LoadUint32(&i.mode)) + kuid := auth.KUID(atomic.LoadUint32(&i.uid)) + kgid := auth.KGID(atomic.LoadUint32(&i.gid)) + if err := vfs.GenericCheckPermissions(creds, ats, mode, kuid, kgid); err != nil { + return err } - return syserror.EOPNOTSUPP + return vfs.CheckXattrPermissions(creds, ats, mode, kuid, name) } // fileDescription is embedded by tmpfs implementations of // vfs.FileDescriptionImpl. +// +// +stateify savable type fileDescription struct { vfsfd vfs.FileDescription vfs.FileDescriptionDefaultImpl @@ -738,20 +724,20 @@ func (fd *fileDescription) StatFS(ctx context.Context) (linux.Statfs, error) { return globalStatfs, nil } -// Listxattr implements vfs.FileDescriptionImpl.Listxattr. -func (fd *fileDescription) Listxattr(ctx context.Context, size uint64) ([]string, error) { - return fd.inode().listxattr(size) +// ListXattr implements vfs.FileDescriptionImpl.ListXattr. +func (fd *fileDescription) ListXattr(ctx context.Context, size uint64) ([]string, error) { + return fd.inode().listXattr(size) } -// Getxattr implements vfs.FileDescriptionImpl.Getxattr. -func (fd *fileDescription) Getxattr(ctx context.Context, opts vfs.GetxattrOptions) (string, error) { - return fd.inode().getxattr(auth.CredentialsFromContext(ctx), &opts) +// GetXattr implements vfs.FileDescriptionImpl.GetXattr. +func (fd *fileDescription) GetXattr(ctx context.Context, opts vfs.GetXattrOptions) (string, error) { + return fd.inode().getXattr(auth.CredentialsFromContext(ctx), &opts) } -// Setxattr implements vfs.FileDescriptionImpl.Setxattr. -func (fd *fileDescription) Setxattr(ctx context.Context, opts vfs.SetxattrOptions) error { +// SetXattr implements vfs.FileDescriptionImpl.SetXattr. +func (fd *fileDescription) SetXattr(ctx context.Context, opts vfs.SetXattrOptions) error { d := fd.dentry() - if err := d.inode.setxattr(auth.CredentialsFromContext(ctx), &opts); err != nil { + if err := d.inode.setXattr(auth.CredentialsFromContext(ctx), &opts); err != nil { return err } @@ -760,10 +746,10 @@ func (fd *fileDescription) Setxattr(ctx context.Context, opts vfs.SetxattrOption return nil } -// Removexattr implements vfs.FileDescriptionImpl.Removexattr. -func (fd *fileDescription) Removexattr(ctx context.Context, name string) error { +// RemoveXattr implements vfs.FileDescriptionImpl.RemoveXattr. +func (fd *fileDescription) RemoveXattr(ctx context.Context, name string) error { d := fd.dentry() - if err := d.inode.removexattr(auth.CredentialsFromContext(ctx), name); err != nil { + if err := d.inode.removeXattr(auth.CredentialsFromContext(ctx), name); err != nil { return err } @@ -772,37 +758,6 @@ func (fd *fileDescription) Removexattr(ctx context.Context, name string) error { return nil } -// NewMemfd creates a new tmpfs regular file and file description that can back -// an anonymous fd created by memfd_create. -func NewMemfd(ctx context.Context, creds *auth.Credentials, mount *vfs.Mount, allowSeals bool, name string) (*vfs.FileDescription, error) { - fs, ok := mount.Filesystem().Impl().(*filesystem) - if !ok { - panic("NewMemfd() called with non-tmpfs mount") - } - - // Per Linux, mm/shmem.c:__shmem_file_setup(), memfd inodes are set up with - // S_IRWXUGO. - inode := fs.newRegularFile(creds.EffectiveKUID, creds.EffectiveKGID, 0777) - rf := inode.impl.(*regularFile) - if allowSeals { - rf.seals = 0 - } - - d := fs.newDentry(inode) - defer d.DecRef(ctx) - d.name = name - - // Per Linux, mm/shmem.c:__shmem_file_setup(), memfd files are set up with - // FMODE_READ | FMODE_WRITE. - var fd regularFileFD - fd.Init(&inode.locks) - flags := uint32(linux.O_RDWR) - if err := fd.vfsfd.Init(&fd, flags, mount, &d.vfsd, &vfs.FileDescriptionOptions{}); err != nil { - return nil, err - } - return &fd.vfsfd, nil -} - // LockPOSIX implements vfs.FileDescriptionImpl.LockPOSIX. func (fd *fileDescription) LockPOSIX(ctx context.Context, uid fslock.UniqueID, t fslock.LockType, start, length uint64, whence int16, block fslock.Blocker) error { return fd.Locks().LockPOSIX(ctx, &fd.vfsfd, uid, t, start, length, whence, block) diff --git a/pkg/sentry/fsimpl/tmpfs/tmpfs_test.go b/pkg/sentry/fsimpl/tmpfs/tmpfs_test.go index 6f3e3ae6f..99c8e3c0f 100644 --- a/pkg/sentry/fsimpl/tmpfs/tmpfs_test.go +++ b/pkg/sentry/fsimpl/tmpfs/tmpfs_test.go @@ -41,7 +41,7 @@ func newTmpfsRoot(ctx context.Context) (*vfs.VirtualFilesystem, vfs.VirtualDentr vfsObj.MustRegisterFilesystemType("tmpfs", FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{ AllowUserMount: true, }) - mntns, err := vfsObj.NewMountNamespace(ctx, creds, "", "tmpfs", &vfs.GetFilesystemOptions{}) + mntns, err := vfsObj.NewMountNamespace(ctx, creds, "", "tmpfs", &vfs.MountOptions{}) if err != nil { return nil, vfs.VirtualDentry{}, nil, fmt.Errorf("failed to create tmpfs root mount: %v", err) } diff --git a/pkg/sentry/fsimpl/verity/BUILD b/pkg/sentry/fsimpl/verity/BUILD index 326c4ed90..0ca750281 100644 --- a/pkg/sentry/fsimpl/verity/BUILD +++ b/pkg/sentry/fsimpl/verity/BUILD @@ -1,4 +1,4 @@ -load("//tools:defs.bzl", "go_library") +load("//tools:defs.bzl", "go_library", "go_test") licenses(["notice"]) @@ -13,12 +13,35 @@ go_library( "//pkg/abi/linux", "//pkg/context", "//pkg/fspath", + "//pkg/marshal/primitive", "//pkg/merkletree", + "//pkg/sentry/arch", "//pkg/sentry/fs/lock", + "//pkg/sentry/kernel", "//pkg/sentry/kernel/auth", "//pkg/sentry/socket/unix/transport", "//pkg/sentry/vfs", "//pkg/sync", "//pkg/syserror", + "//pkg/usermem", + ], +) + +go_test( + name = "verity_test", + srcs = [ + "verity_test.go", + ], + library = ":verity", + deps = [ + "//pkg/abi/linux", + "//pkg/context", + "//pkg/fspath", + "//pkg/sentry/arch", + "//pkg/sentry/fsimpl/tmpfs", + "//pkg/sentry/kernel/auth", + "//pkg/sentry/kernel/contexttest", + "//pkg/sentry/vfs", + "//pkg/usermem", ], ) diff --git a/pkg/sentry/fsimpl/verity/filesystem.go b/pkg/sentry/fsimpl/verity/filesystem.go index 0e17dbddc..a560b0797 100644 --- a/pkg/sentry/fsimpl/verity/filesystem.go +++ b/pkg/sentry/fsimpl/verity/filesystem.go @@ -19,6 +19,7 @@ import ( "fmt" "io" "strconv" + "strings" "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" @@ -179,23 +180,19 @@ func (fs *filesystem) verifyChild(ctx context.Context, parent *dentry, child *de // corresponding Merkle tree file. // This is the offset of the root hash for child in its parent's Merkle // tree file. - off, err := vfsObj.GetxattrAt(ctx, fs.creds, &vfs.PathOperation{ + off, err := vfsObj.GetXattrAt(ctx, fs.creds, &vfs.PathOperation{ Root: child.lowerMerkleVD, Start: child.lowerMerkleVD, - }, &vfs.GetxattrOptions{ + }, &vfs.GetXattrOptions{ Name: merkleOffsetInParentXattr, - // Offset is a 32 bit integer. - Size: sizeOfInt32, + Size: sizeOfStringInt32, }) // The Merkle tree file for the child should have been created and // contains the expected xattrs. If the file or the xattr does not // exist, it indicates unexpected modifications to the file system. if err == syserror.ENOENT || err == syserror.ENODATA { - if noCrashOnVerificationFailure { - return nil, err - } - panic(fmt.Sprintf("Failed to get xattr %s for %s: %v", merkleOffsetInParentXattr, childPath, err)) + return nil, alertIntegrityViolation(err, fmt.Sprintf("Failed to get xattr %s for %s: %v", merkleOffsetInParentXattr, childPath, err)) } if err != nil { return nil, err @@ -204,10 +201,7 @@ func (fs *filesystem) verifyChild(ctx context.Context, parent *dentry, child *de // unexpected modifications to the file system. offset, err := strconv.Atoi(off) if err != nil { - if noCrashOnVerificationFailure { - return nil, syserror.EINVAL - } - panic(fmt.Sprintf("Failed to convert xattr %s for %s to int: %v", merkleOffsetInParentXattr, childPath, err)) + return nil, alertIntegrityViolation(err, fmt.Sprintf("Failed to convert xattr %s for %s to int: %v", merkleOffsetInParentXattr, childPath, err)) } // Open parent Merkle tree file to read and verify child's root hash. @@ -221,10 +215,7 @@ func (fs *filesystem) verifyChild(ctx context.Context, parent *dentry, child *de // The parent Merkle tree file should have been created. If it's // missing, it indicates an unexpected modification to the file system. if err == syserror.ENOENT { - if noCrashOnVerificationFailure { - return nil, err - } - panic(fmt.Sprintf("Failed to open parent Merkle file for %s: %v", childPath, err)) + return nil, alertIntegrityViolation(err, fmt.Sprintf("Failed to open parent Merkle file for %s: %v", childPath, err)) } if err != nil { return nil, err @@ -233,19 +224,16 @@ func (fs *filesystem) verifyChild(ctx context.Context, parent *dentry, child *de // dataSize is the size of raw data for the Merkle tree. For a file, // dataSize is the size of the whole file. For a directory, dataSize is // the size of all its children's root hashes. - dataSize, err := parentMerkleFD.Getxattr(ctx, &vfs.GetxattrOptions{ + dataSize, err := parentMerkleFD.GetXattr(ctx, &vfs.GetXattrOptions{ Name: merkleSizeXattr, - Size: sizeOfInt32, + Size: sizeOfStringInt32, }) // The Merkle tree file for the child should have been created and // contains the expected xattrs. If the file or the xattr does not // exist, it indicates unexpected modifications to the file system. if err == syserror.ENOENT || err == syserror.ENODATA { - if noCrashOnVerificationFailure { - return nil, err - } - panic(fmt.Sprintf("Failed to get xattr %s for %s: %v", merkleSizeXattr, childPath, err)) + return nil, alertIntegrityViolation(err, fmt.Sprintf("Failed to get xattr %s for %s: %v", merkleSizeXattr, childPath, err)) } if err != nil { return nil, err @@ -255,10 +243,7 @@ func (fs *filesystem) verifyChild(ctx context.Context, parent *dentry, child *de // unexpected modifications to the file system. parentSize, err := strconv.Atoi(dataSize) if err != nil { - if noCrashOnVerificationFailure { - return nil, syserror.EINVAL - } - panic(fmt.Sprintf("Failed to convert xattr %s for %s to int: %v", merkleSizeXattr, childPath, err)) + return nil, alertIntegrityViolation(syserror.EINVAL, fmt.Sprintf("Failed to convert xattr %s for %s to int: %v", merkleSizeXattr, childPath, err)) } fdReader := vfs.FileReadWriteSeeker{ @@ -270,11 +255,8 @@ func (fs *filesystem) verifyChild(ctx context.Context, parent *dentry, child *de // contain the root hash of the children in the parent Merkle tree when // Verify returns with success. var buf bytes.Buffer - if err := merkletree.Verify(&buf, &fdReader, &fdReader, int64(parentSize), int64(offset), int64(merkletree.DigestSize()), parent.rootHash, true /* dataAndTreeInSameFile */); err != nil && err != io.EOF { - if noCrashOnVerificationFailure { - return nil, syserror.EIO - } - panic(fmt.Sprintf("Verification for %s failed: %v", childPath, err)) + if _, err := merkletree.Verify(&buf, &fdReader, &fdReader, int64(parentSize), int64(offset), int64(merkletree.DigestSize()), parent.rootHash, true /* dataAndTreeInSameFile */); err != nil && err != io.EOF { + return nil, alertIntegrityViolation(syserror.EIO, fmt.Sprintf("Verification for %s failed: %v", childPath, err)) } // Cache child root hash when it's verified the first time. @@ -370,10 +352,7 @@ func (fs *filesystem) lookupAndVerifyLocked(ctx context.Context, parent *dentry, // corresponding Merkle tree is found. This indicates an // unexpected modification to the file system that // removed/renamed the child. - if noCrashOnVerificationFailure { - return nil, childErr - } - panic(fmt.Sprintf("Target file %s is expected but missing", parentPath+"/"+name)) + return nil, alertIntegrityViolation(childErr, fmt.Sprintf("Target file %s is expected but missing", parentPath+"/"+name)) } else if childErr == nil && childMerkleErr == syserror.ENOENT { // If in allowRuntimeEnable mode, and the Merkle tree file is // not created yet, we create an empty Merkle tree file, so that @@ -392,6 +371,7 @@ func (fs *filesystem) lookupAndVerifyLocked(ctx context.Context, parent *dentry, Path: fspath.Parse(childMerkleFilename), }, &vfs.OpenOptions{ Flags: linux.O_RDWR | linux.O_CREAT, + Mode: 0644, }) if err != nil { return nil, err @@ -409,11 +389,16 @@ func (fs *filesystem) lookupAndVerifyLocked(ctx context.Context, parent *dentry, // If runtime enable is not allowed. This indicates an // unexpected modification to the file system that // removed/renamed the Merkle tree file. - if noCrashOnVerificationFailure { - return nil, childMerkleErr - } - panic(fmt.Sprintf("Expected Merkle file for target %s but none found", parentPath+"/"+name)) + return nil, alertIntegrityViolation(childMerkleErr, fmt.Sprintf("Expected Merkle file for target %s but none found", parentPath+"/"+name)) } + } else if childErr == syserror.ENOENT && childMerkleErr == syserror.ENOENT { + // Both the child and the corresponding Merkle tree are missing. + // This could be an unexpected modification or due to incorrect + // parameter. + // TODO(b/167752508): Investigate possible ways to differentiate + // cases that both files are deleted from cases that they never + // exist in the file system. + return nil, alertIntegrityViolation(childErr, fmt.Sprintf("Failed to find file %s", parentPath+"/"+name)) } mask := uint32(linux.STATX_TYPE | linux.STATX_MODE | linux.STATX_UID | linux.STATX_GID) @@ -572,8 +557,183 @@ func (fs *filesystem) MknodAt(ctx context.Context, rp *vfs.ResolvingPath, opts v // OpenAt implements vfs.FilesystemImpl.OpenAt. func (fs *filesystem) OpenAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.OpenOptions) (*vfs.FileDescription, error) { - //TODO(b/159261227): Implement OpenAt. - return nil, nil + // Verity fs is read-only. + if opts.Flags&(linux.O_WRONLY|linux.O_CREAT) != 0 { + return nil, syserror.EROFS + } + + var ds *[]*dentry + fs.renameMu.RLock() + defer fs.renameMuRUnlockAndCheckDrop(ctx, &ds) + + start := rp.Start().Impl().(*dentry) + if rp.Done() { + return start.openLocked(ctx, rp, &opts) + } + +afterTrailingSymlink: + parent, err := fs.walkParentDirLocked(ctx, rp, start, &ds) + if err != nil { + return nil, err + } + + // Check for search permission in the parent directory. + if err := parent.checkPermissions(rp.Credentials(), vfs.MayExec); err != nil { + return nil, err + } + + // Open existing child or follow symlink. + parent.dirMu.Lock() + child, err := fs.stepLocked(ctx, rp, parent, false /*mayFollowSymlinks*/, &ds) + parent.dirMu.Unlock() + if err != nil { + return nil, err + } + if child.isSymlink() && rp.ShouldFollowSymlink() { + target, err := child.readlink(ctx) + if err != nil { + return nil, err + } + if err := rp.HandleSymlink(target); err != nil { + return nil, err + } + start = parent + goto afterTrailingSymlink + } + return child.openLocked(ctx, rp, &opts) +} + +// Preconditions: fs.renameMu must be locked. +func (d *dentry) openLocked(ctx context.Context, rp *vfs.ResolvingPath, opts *vfs.OpenOptions) (*vfs.FileDescription, error) { + // Users should not open the Merkle tree files. Those are for verity fs + // use only. + if strings.Contains(d.name, merklePrefix) { + return nil, syserror.EPERM + } + ats := vfs.AccessTypesForOpenFlags(opts) + if err := d.checkPermissions(rp.Credentials(), ats); err != nil { + return nil, err + } + + // Verity fs is read-only. + if ats&vfs.MayWrite != 0 { + return nil, syserror.EROFS + } + + // Get the path to the target file. This is only used to provide path + // information in failure case. + path, err := d.fs.vfsfs.VirtualFilesystem().PathnameWithDeleted(ctx, d.fs.rootDentry.lowerVD, d.lowerVD) + if err != nil { + return nil, err + } + + // Open the file in the underlying file system. + lowerFD, err := rp.VirtualFilesystem().OpenAt(ctx, d.fs.creds, &vfs.PathOperation{ + Root: d.lowerVD, + Start: d.lowerVD, + }, opts) + + // The file should exist, as we succeeded in finding its dentry. If it's + // missing, it indicates an unexpected modification to the file system. + if err != nil { + if err == syserror.ENOENT { + return nil, alertIntegrityViolation(err, fmt.Sprintf("File %s expected but not found", path)) + } + return nil, err + } + + // lowerFD needs to be cleaned up if any error occurs. IncRef will be + // called if a verity FD is successfully created. + defer lowerFD.DecRef(ctx) + + // Open the Merkle tree file corresponding to the current file/directory + // to be used later for verifying Read/Walk. + merkleReader, err := rp.VirtualFilesystem().OpenAt(ctx, d.fs.creds, &vfs.PathOperation{ + Root: d.lowerMerkleVD, + Start: d.lowerMerkleVD, + }, &vfs.OpenOptions{ + Flags: linux.O_RDONLY, + }) + + // The Merkle tree file should exist, as we succeeded in finding its + // dentry. If it's missing, it indicates an unexpected modification to + // the file system. + if err != nil { + if err == syserror.ENOENT { + return nil, alertIntegrityViolation(err, fmt.Sprintf("Merkle file for %s expected but not found", path)) + } + return nil, err + } + + // merkleReader needs to be cleaned up if any error occurs. IncRef will + // be called if a verity FD is successfully created. + defer merkleReader.DecRef(ctx) + + lowerFlags := lowerFD.StatusFlags() + lowerFDOpts := lowerFD.Options() + var merkleWriter *vfs.FileDescription + var parentMerkleWriter *vfs.FileDescription + + // Only open the Merkle tree files for write if in allowRuntimeEnable + // mode. + if d.fs.allowRuntimeEnable { + merkleWriter, err = rp.VirtualFilesystem().OpenAt(ctx, d.fs.creds, &vfs.PathOperation{ + Root: d.lowerMerkleVD, + Start: d.lowerMerkleVD, + }, &vfs.OpenOptions{ + Flags: linux.O_WRONLY | linux.O_APPEND, + }) + if err != nil { + if err == syserror.ENOENT { + return nil, alertIntegrityViolation(err, fmt.Sprintf("Merkle file for %s expected but not found", path)) + } + return nil, err + } + // merkleWriter is cleaned up if any error occurs. IncRef will + // be called if a verity FD is created successfully. + defer merkleWriter.DecRef(ctx) + + if d.parent != nil { + parentMerkleWriter, err = rp.VirtualFilesystem().OpenAt(ctx, d.fs.creds, &vfs.PathOperation{ + Root: d.parent.lowerMerkleVD, + Start: d.parent.lowerMerkleVD, + }, &vfs.OpenOptions{ + Flags: linux.O_WRONLY | linux.O_APPEND, + }) + if err != nil { + if err == syserror.ENOENT { + parentPath, _ := d.fs.vfsfs.VirtualFilesystem().PathnameWithDeleted(ctx, d.fs.rootDentry.lowerVD, d.parent.lowerVD) + return nil, alertIntegrityViolation(err, fmt.Sprintf("Merkle file for %s expected but not found", parentPath)) + } + return nil, err + } + // parentMerkleWriter is cleaned up if any error occurs. IncRef + // will be called if a verity FD is created successfully. + defer parentMerkleWriter.DecRef(ctx) + } + } + + fd := &fileDescription{ + d: d, + lowerFD: lowerFD, + merkleReader: merkleReader, + merkleWriter: merkleWriter, + parentMerkleWriter: parentMerkleWriter, + isDir: d.isDir(), + } + + if err := fd.vfsfd.Init(fd, lowerFlags, rp.Mount(), &d.vfsd, &lowerFDOpts); err != nil { + return nil, err + } + lowerFD.IncRef() + merkleReader.IncRef() + if merkleWriter != nil { + merkleWriter.IncRef() + } + if parentMerkleWriter != nil { + parentMerkleWriter.IncRef() + } + return &fd.vfsfd, err } // ReadlinkAt implements vfs.FilesystemImpl.ReadlinkAt. @@ -649,7 +809,7 @@ func (fs *filesystem) UnlinkAt(ctx context.Context, rp *vfs.ResolvingPath) error return syserror.EROFS } -// BoundEndpointAt implements FilesystemImpl.BoundEndpointAt. +// BoundEndpointAt implements vfs.FilesystemImpl.BoundEndpointAt. func (fs *filesystem) BoundEndpointAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.BoundEndpointOptions) (transport.BoundEndpoint, error) { var ds *[]*dentry fs.renameMu.RLock() @@ -660,8 +820,8 @@ func (fs *filesystem) BoundEndpointAt(ctx context.Context, rp *vfs.ResolvingPath return nil, syserror.ECONNREFUSED } -// ListxattrAt implements vfs.FilesystemImpl.ListxattrAt. -func (fs *filesystem) ListxattrAt(ctx context.Context, rp *vfs.ResolvingPath, size uint64) ([]string, error) { +// ListXattrAt implements vfs.FilesystemImpl.ListXattrAt. +func (fs *filesystem) ListXattrAt(ctx context.Context, rp *vfs.ResolvingPath, size uint64) ([]string, error) { var ds *[]*dentry fs.renameMu.RLock() defer fs.renameMuRUnlockAndCheckDrop(ctx, &ds) @@ -670,14 +830,14 @@ func (fs *filesystem) ListxattrAt(ctx context.Context, rp *vfs.ResolvingPath, si return nil, err } lowerVD := d.lowerVD - return fs.vfsfs.VirtualFilesystem().ListxattrAt(ctx, d.fs.creds, &vfs.PathOperation{ + return fs.vfsfs.VirtualFilesystem().ListXattrAt(ctx, d.fs.creds, &vfs.PathOperation{ Root: lowerVD, Start: lowerVD, }, size) } -// GetxattrAt implements vfs.FilesystemImpl.GetxattrAt. -func (fs *filesystem) GetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.GetxattrOptions) (string, error) { +// GetXattrAt implements vfs.FilesystemImpl.GetXattrAt. +func (fs *filesystem) GetXattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.GetXattrOptions) (string, error) { var ds *[]*dentry fs.renameMu.RLock() defer fs.renameMuRUnlockAndCheckDrop(ctx, &ds) @@ -686,20 +846,20 @@ func (fs *filesystem) GetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opt return "", err } lowerVD := d.lowerVD - return fs.vfsfs.VirtualFilesystem().GetxattrAt(ctx, d.fs.creds, &vfs.PathOperation{ + return fs.vfsfs.VirtualFilesystem().GetXattrAt(ctx, d.fs.creds, &vfs.PathOperation{ Root: lowerVD, Start: lowerVD, }, &opts) } -// SetxattrAt implements vfs.FilesystemImpl.SetxattrAt. -func (fs *filesystem) SetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.SetxattrOptions) error { +// SetXattrAt implements vfs.FilesystemImpl.SetXattrAt. +func (fs *filesystem) SetXattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.SetXattrOptions) error { // Verity file system is read-only. return syserror.EROFS } -// RemovexattrAt implements vfs.FilesystemImpl.RemovexattrAt. -func (fs *filesystem) RemovexattrAt(ctx context.Context, rp *vfs.ResolvingPath, name string) error { +// RemoveXattrAt implements vfs.FilesystemImpl.RemoveXattrAt. +func (fs *filesystem) RemoveXattrAt(ctx context.Context, rp *vfs.ResolvingPath, name string) error { // Verity file system is read-only. return syserror.EROFS } diff --git a/pkg/sentry/fsimpl/verity/verity.go b/pkg/sentry/fsimpl/verity/verity.go index eedb5f484..fc5eabbca 100644 --- a/pkg/sentry/fsimpl/verity/verity.go +++ b/pkg/sentry/fsimpl/verity/verity.go @@ -22,16 +22,23 @@ package verity import ( + "fmt" + "strconv" "sync/atomic" "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/fspath" + "gvisor.dev/gvisor/pkg/marshal/primitive" + "gvisor.dev/gvisor/pkg/merkletree" + "gvisor.dev/gvisor/pkg/sentry/arch" fslock "gvisor.dev/gvisor/pkg/sentry/fs/lock" + "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/syserror" + "gvisor.dev/gvisor/pkg/usermem" ) // Name is the default filesystem name. @@ -50,8 +57,9 @@ const merkleOffsetInParentXattr = "user.merkle.offset" // whole file. For a directory, it's the size of all its children's root hashes. const merkleSizeXattr = "user.merkle.size" -// sizeOfInt32 is the size in bytes for a 32 bit integer in extended attributes. -const sizeOfInt32 = 4 +// sizeOfStringInt32 is the size for a 32 bit integer stored as string in +// extended attributes. The maximum value of a 32 bit integer is 10 digits. +const sizeOfStringInt32 = 10 // noCrashOnVerificationFailure indicates whether the sandbox should panic // whenever verification fails. If true, an error is returned instead of @@ -66,9 +74,13 @@ var noCrashOnVerificationFailure bool var verityMu sync.RWMutex // FilesystemType implements vfs.FilesystemType. +// +// +stateify savable type FilesystemType struct{} // filesystem implements vfs.FilesystemImpl. +// +// +stateify savable type filesystem struct { vfsfs vfs.Filesystem @@ -93,11 +105,13 @@ type filesystem struct { // renameMu synchronizes renaming with non-renaming operations in order // to ensure consistent lock ordering between dentry.dirMu in different // dentries. - renameMu sync.RWMutex + renameMu sync.RWMutex `state:"nosave"` } // InternalFilesystemOptions may be passed as // vfs.GetFilesystemOptions.InternalData to FilesystemType.GetFilesystem. +// +// +stateify savable type InternalFilesystemOptions struct { // RootMerkleFileName is the name of the verity root Merkle tree file. RootMerkleFileName string @@ -128,6 +142,16 @@ func (FilesystemType) Name() string { return Name } +// alertIntegrityViolation alerts a violation of integrity, which usually means +// unexpected modification to the file system is detected. In +// noCrashOnVerificationFailure mode, it returns an error, otherwise it panic. +func alertIntegrityViolation(err error, msg string) error { + if noCrashOnVerificationFailure { + return err + } + panic(msg) +} + // GetFilesystem implements vfs.FilesystemType.GetFilesystem. func (fstype FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.VirtualFilesystem, creds *auth.Credentials, source string, opts vfs.GetFilesystemOptions) (*vfs.Filesystem, *vfs.Dentry, error) { iopts, ok := opts.InternalData.(InternalFilesystemOptions) @@ -141,6 +165,7 @@ func (fstype FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt // verity, and should not be exposed or connected. mopts := &vfs.MountOptions{ GetFilesystemOptions: iopts.LowerGetFSOptions, + InternalMount: true, } mnt, err := vfsObj.MountDisconnected(ctx, creds, "", iopts.LowerName, mopts) if err != nil { @@ -197,15 +222,12 @@ func (fstype FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt return nil, nil, err } } else if err != nil { - // Failed to get dentry for the root Merkle file. This indicates - // an attack that removed/renamed the root Merkle file, or it's - // never generated. - if noCrashOnVerificationFailure { - fs.vfsfs.DecRef(ctx) - d.DecRef(ctx) - return nil, nil, err - } - panic("Failed to find root Merkle file") + // Failed to get dentry for the root Merkle file. This + // indicates an unexpected modification that removed/renamed + // the root Merkle file, or it's never generated. + fs.vfsfs.DecRef(ctx) + d.DecRef(ctx) + return nil, nil, alertIntegrityViolation(err, "Failed to find root Merkle file") } d.lowerMerkleVD = lowerMerkleVD @@ -243,6 +265,8 @@ func (fs *filesystem) Release(ctx context.Context) { } // dentry implements vfs.DentryImpl. +// +// +stateify savable type dentry struct { vfsd vfs.Dentry @@ -269,7 +293,7 @@ type dentry struct { // and dirents (if not nil) is a cache of dirents as returned by // directoryFDs representing this directory. children is protected by // dirMu. - dirMu sync.Mutex + dirMu sync.Mutex `state:"nosave"` children map[string]*dentry // lowerVD is the VirtualDentry in the underlying file system. @@ -413,6 +437,8 @@ func (d *dentry) readlink(ctx context.Context) (string, error) { // FileDescription is a wrapper of the underlying lowerFD, with support to build // Merkle trees through the Linux fs-verity API to verify contents read from // lowerFD. +// +// +stateify savable type fileDescription struct { vfsfd vfs.FileDescription vfs.FileDescriptionDefaultImpl @@ -471,12 +497,247 @@ func (fd *fileDescription) SetStat(ctx context.Context, opts vfs.SetStatOptions) return syserror.EPERM } +// generateMerkle generates a Merkle tree file for fd. If fd points to a file +// /foo/bar, a Merkle tree file /foo/.merkle.verity.bar is generated. The root +// hash of the generated Merkle tree and the data size is returned. +// If fd points to a regular file, the data is the content of the file. If fd +// points to a directory, the data is all root hahes of its children, written +// to the Merkle tree file. +func (fd *fileDescription) generateMerkle(ctx context.Context) ([]byte, uint64, error) { + fdReader := vfs.FileReadWriteSeeker{ + FD: fd.lowerFD, + Ctx: ctx, + } + merkleReader := vfs.FileReadWriteSeeker{ + FD: fd.merkleReader, + Ctx: ctx, + } + merkleWriter := vfs.FileReadWriteSeeker{ + FD: fd.merkleWriter, + Ctx: ctx, + } + var rootHash []byte + var dataSize uint64 + + switch atomic.LoadUint32(&fd.d.mode) & linux.S_IFMT { + case linux.S_IFREG: + // For a regular file, generate a Merkle tree based on its + // content. + var err error + stat, err := fd.lowerFD.Stat(ctx, vfs.StatOptions{}) + if err != nil { + return nil, 0, err + } + dataSize = stat.Size + + rootHash, err = merkletree.Generate(&fdReader, int64(dataSize), &merkleReader, &merkleWriter, false /* dataAndTreeInSameFile */) + if err != nil { + return nil, 0, err + } + case linux.S_IFDIR: + // For a directory, generate a Merkle tree based on the root + // hashes of its children that has already been written to the + // Merkle tree file. + merkleStat, err := fd.merkleReader.Stat(ctx, vfs.StatOptions{}) + if err != nil { + return nil, 0, err + } + dataSize = merkleStat.Size + + rootHash, err = merkletree.Generate(&merkleReader, int64(dataSize), &merkleReader, &merkleWriter, true /* dataAndTreeInSameFile */) + if err != nil { + return nil, 0, err + } + default: + // TODO(b/167728857): Investigate whether and how we should + // enable other types of file. + return nil, 0, syserror.EINVAL + } + return rootHash, dataSize, nil +} + +// enableVerity enables verity features on fd by generating a Merkle tree file +// and stores its root hash in its parent directory's Merkle tree. +func (fd *fileDescription) enableVerity(ctx context.Context, uio usermem.IO) (uintptr, error) { + if !fd.d.fs.allowRuntimeEnable { + return 0, syserror.EPERM + } + + // Lock to prevent other threads performing enable or access the file + // while it's being enabled. + verityMu.Lock() + defer verityMu.Unlock() + + // In allowRuntimeEnable mode, the underlying fd and read/write fd for + // the Merkle tree file should have all been initialized. For any file + // or directory other than the root, the parent Merkle tree file should + // have also been initialized. + if fd.lowerFD == nil || fd.merkleReader == nil || fd.merkleWriter == nil || (fd.parentMerkleWriter == nil && fd.d != fd.d.fs.rootDentry) { + return 0, alertIntegrityViolation(syserror.EIO, "Unexpected verity fd: missing expected underlying fds") + } + + rootHash, dataSize, err := fd.generateMerkle(ctx) + if err != nil { + return 0, err + } + + if fd.parentMerkleWriter != nil { + stat, err := fd.parentMerkleWriter.Stat(ctx, vfs.StatOptions{}) + if err != nil { + return 0, err + } + + // Write the root hash of fd to the parent directory's Merkle + // tree file, as it should be part of the parent Merkle tree + // data. parentMerkleWriter is open with O_APPEND, so it + // should write directly to the end of the file. + if _, err = fd.parentMerkleWriter.Write(ctx, usermem.BytesIOSequence(rootHash), vfs.WriteOptions{}); err != nil { + return 0, err + } + + // Record the offset of the root hash of fd in parent directory's + // Merkle tree file. + if err := fd.merkleWriter.SetXattr(ctx, &vfs.SetXattrOptions{ + Name: merkleOffsetInParentXattr, + Value: strconv.Itoa(int(stat.Size)), + }); err != nil { + return 0, err + } + } + + // Record the size of the data being hashed for fd. + if err := fd.merkleWriter.SetXattr(ctx, &vfs.SetXattrOptions{ + Name: merkleSizeXattr, + Value: strconv.Itoa(int(dataSize)), + }); err != nil { + return 0, err + } + fd.d.rootHash = append(fd.d.rootHash, rootHash...) + return 0, nil +} + +// measureVerity returns the root hash of fd, saved in args[2]. +func (fd *fileDescription) measureVerity(ctx context.Context, uio usermem.IO, verityDigest usermem.Addr) (uintptr, error) { + t := kernel.TaskFromContext(ctx) + var metadata linux.DigestMetadata + + // If allowRuntimeEnable is true, an empty fd.d.rootHash indicates that + // verity is not enabled for the file. If allowRuntimeEnable is false, + // this is an integrity violation because all files should have verity + // enabled, in which case fd.d.rootHash should be set. + if len(fd.d.rootHash) == 0 { + if fd.d.fs.allowRuntimeEnable { + return 0, syserror.ENODATA + } + return 0, alertIntegrityViolation(syserror.ENODATA, "Ioctl measureVerity: no root hash found") + } + + // The first part of VerityDigest is the metadata. + if _, err := metadata.CopyIn(t, verityDigest); err != nil { + return 0, err + } + if metadata.DigestSize < uint16(len(fd.d.rootHash)) { + return 0, syserror.EOVERFLOW + } + + // Populate the output digest size, since DigestSize is both input and + // output. + metadata.DigestSize = uint16(len(fd.d.rootHash)) + + // First copy the metadata. + if _, err := metadata.CopyOut(t, verityDigest); err != nil { + return 0, err + } + + // Now copy the root hash bytes to the memory after metadata. + _, err := t.CopyOutBytes(usermem.Addr(uintptr(verityDigest)+linux.SizeOfDigestMetadata), fd.d.rootHash) + return 0, err +} + +func (fd *fileDescription) verityFlags(ctx context.Context, uio usermem.IO, flags usermem.Addr) (uintptr, error) { + f := int32(0) + + // All enabled files should store a root hash. This flag is not settable + // via FS_IOC_SETFLAGS. + if len(fd.d.rootHash) != 0 { + f |= linux.FS_VERITY_FL + } + + t := kernel.TaskFromContext(ctx) + _, err := primitive.CopyInt32Out(t, flags, f) + return 0, err +} + +// Ioctl implements vfs.FileDescriptionImpl.Ioctl. +func (fd *fileDescription) Ioctl(ctx context.Context, uio usermem.IO, args arch.SyscallArguments) (uintptr, error) { + switch cmd := args[1].Uint(); cmd { + case linux.FS_IOC_ENABLE_VERITY: + return fd.enableVerity(ctx, uio) + case linux.FS_IOC_MEASURE_VERITY: + return fd.measureVerity(ctx, uio, args[2].Pointer()) + case linux.FS_IOC_GETFLAGS: + return fd.verityFlags(ctx, uio, args[2].Pointer()) + default: + // TODO(b/169682228): Investigate which ioctl commands should + // be allowed. + return 0, syserror.ENOSYS + } +} + +// PRead implements vfs.FileDescriptionImpl.PRead. +func (fd *fileDescription) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) { + // No need to verify if the file is not enabled yet in + // allowRuntimeEnable mode. + if fd.d.fs.allowRuntimeEnable && len(fd.d.rootHash) == 0 { + return fd.lowerFD.PRead(ctx, dst, offset, opts) + } + + // dataSize is the size of the whole file. + dataSize, err := fd.merkleReader.GetXattr(ctx, &vfs.GetXattrOptions{ + Name: merkleSizeXattr, + Size: sizeOfStringInt32, + }) + + // The Merkle tree file for the child should have been created and + // contains the expected xattrs. If the xattr does not exist, it + // indicates unexpected modifications to the file system. + if err == syserror.ENODATA { + return 0, alertIntegrityViolation(err, fmt.Sprintf("Failed to get xattr %s: %v", merkleSizeXattr, err)) + } + if err != nil { + return 0, err + } + + // The dataSize xattr should be an integer. If it's not, it indicates + // unexpected modifications to the file system. + size, err := strconv.Atoi(dataSize) + if err != nil { + return 0, alertIntegrityViolation(err, fmt.Sprintf("Failed to convert xattr %s to int: %v", merkleSizeXattr, err)) + } + + dataReader := vfs.FileReadWriteSeeker{ + FD: fd.lowerFD, + Ctx: ctx, + } + + merkleReader := vfs.FileReadWriteSeeker{ + FD: fd.merkleReader, + Ctx: ctx, + } + + n, err := merkletree.Verify(dst.Writer(ctx), &dataReader, &merkleReader, int64(size), offset, dst.NumBytes(), fd.d.rootHash, false /* dataAndTreeInSameFile */) + if err != nil { + return 0, alertIntegrityViolation(syserror.EINVAL, fmt.Sprintf("Verification failed: %v", err)) + } + return n, err +} + // LockPOSIX implements vfs.FileDescriptionImpl.LockPOSIX. func (fd *fileDescription) LockPOSIX(ctx context.Context, uid fslock.UniqueID, t fslock.LockType, start, length uint64, whence int16, block fslock.Blocker) error { - return fd.Locks().LockPOSIX(ctx, &fd.vfsfd, uid, t, start, length, whence, block) + return fd.lowerFD.LockPOSIX(ctx, uid, t, start, length, whence, block) } // UnlockPOSIX implements vfs.FileDescriptionImpl.UnlockPOSIX. func (fd *fileDescription) UnlockPOSIX(ctx context.Context, uid fslock.UniqueID, start, length uint64, whence int16) error { - return fd.Locks().UnlockPOSIX(ctx, &fd.vfsfd, uid, start, length, whence) + return fd.lowerFD.UnlockPOSIX(ctx, uid, start, length, whence) } diff --git a/pkg/sentry/fsimpl/verity/verity_test.go b/pkg/sentry/fsimpl/verity/verity_test.go new file mode 100644 index 000000000..9b5641092 --- /dev/null +++ b/pkg/sentry/fsimpl/verity/verity_test.go @@ -0,0 +1,349 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package verity + +import ( + "fmt" + "io" + "math/rand" + "testing" + "time" + + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/fspath" + "gvisor.dev/gvisor/pkg/sentry/arch" + "gvisor.dev/gvisor/pkg/sentry/fsimpl/tmpfs" + "gvisor.dev/gvisor/pkg/sentry/kernel/auth" + "gvisor.dev/gvisor/pkg/sentry/kernel/contexttest" + "gvisor.dev/gvisor/pkg/sentry/vfs" + "gvisor.dev/gvisor/pkg/usermem" +) + +// rootMerkleFilename is the name of the root Merkle tree file. +const rootMerkleFilename = "root.verity" + +// maxDataSize is the maximum data size written to the file for test. +const maxDataSize = 100000 + +// newVerityRoot creates a new verity mount, and returns the root. The +// underlying file system is tmpfs. If the error is not nil, then cleanup +// should be called when the root is no longer needed. +func newVerityRoot(ctx context.Context) (*vfs.VirtualFilesystem, vfs.VirtualDentry, func(), error) { + rand.Seed(time.Now().UnixNano()) + vfsObj := &vfs.VirtualFilesystem{} + if err := vfsObj.Init(ctx); err != nil { + return nil, vfs.VirtualDentry{}, nil, fmt.Errorf("VFS init: %v", err) + } + + vfsObj.MustRegisterFilesystemType("verity", FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{ + AllowUserMount: true, + }) + + vfsObj.MustRegisterFilesystemType("tmpfs", tmpfs.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{ + AllowUserMount: true, + }) + + mntns, err := vfsObj.NewMountNamespace(ctx, auth.CredentialsFromContext(ctx), "", "verity", &vfs.MountOptions{ + GetFilesystemOptions: vfs.GetFilesystemOptions{ + InternalData: InternalFilesystemOptions{ + RootMerkleFileName: rootMerkleFilename, + LowerName: "tmpfs", + AllowRuntimeEnable: true, + NoCrashOnVerificationFailure: true, + }, + }, + }) + if err != nil { + return nil, vfs.VirtualDentry{}, nil, fmt.Errorf("failed to create verity root mount: %v", err) + } + root := mntns.Root() + return vfsObj, root, func() { + root.DecRef(ctx) + mntns.DecRef(ctx) + }, nil +} + +// newFileFD creates a new file in the verity mount, and returns the FD. The FD +// points to a file that has random data generated. +func newFileFD(ctx context.Context, vfsObj *vfs.VirtualFilesystem, root vfs.VirtualDentry, filePath string, mode linux.FileMode) (*vfs.FileDescription, int, error) { + creds := auth.CredentialsFromContext(ctx) + lowerRoot := root.Dentry().Impl().(*dentry).lowerVD + + // Create the file in the underlying file system. + lowerFD, err := vfsObj.OpenAt(ctx, creds, &vfs.PathOperation{ + Root: lowerRoot, + Start: lowerRoot, + Path: fspath.Parse(filePath), + }, &vfs.OpenOptions{ + Flags: linux.O_RDWR | linux.O_CREAT | linux.O_EXCL, + Mode: linux.ModeRegular | mode, + }) + if err != nil { + return nil, 0, err + } + + // Generate random data to be written to the file. + dataSize := rand.Intn(maxDataSize) + 1 + data := make([]byte, dataSize) + rand.Read(data) + + // Write directly to the underlying FD, since verity FD is read-only. + n, err := lowerFD.Write(ctx, usermem.BytesIOSequence(data), vfs.WriteOptions{}) + if err != nil { + return nil, 0, err + } + + if n != int64(len(data)) { + return nil, 0, fmt.Errorf("lowerFD.Write got write length %d, want %d", n, len(data)) + } + + lowerFD.DecRef(ctx) + + // Now open the verity file descriptor. + fd, err := vfsObj.OpenAt(ctx, creds, &vfs.PathOperation{ + Root: root, + Start: root, + Path: fspath.Parse(filePath), + }, &vfs.OpenOptions{ + Flags: linux.O_RDONLY, + Mode: linux.ModeRegular | mode, + }) + return fd, dataSize, err +} + +// corruptRandomBit randomly flips a bit in the file represented by fd. +func corruptRandomBit(ctx context.Context, fd *vfs.FileDescription, size int) error { + // Flip a random bit in the underlying file. + randomPos := int64(rand.Intn(size)) + byteToModify := make([]byte, 1) + if _, err := fd.PRead(ctx, usermem.BytesIOSequence(byteToModify), randomPos, vfs.ReadOptions{}); err != nil { + return fmt.Errorf("lowerFD.PRead failed: %v", err) + } + byteToModify[0] ^= 1 + if _, err := fd.PWrite(ctx, usermem.BytesIOSequence(byteToModify), randomPos, vfs.WriteOptions{}); err != nil { + return fmt.Errorf("lowerFD.PWrite failed: %v", err) + } + return nil +} + +// TestOpen ensures that when a file is created, the corresponding Merkle tree +// file and the root Merkle tree file exist. +func TestOpen(t *testing.T) { + ctx := contexttest.Context(t) + vfsObj, root, cleanup, err := newVerityRoot(ctx) + if err != nil { + t.Fatalf("Failed to create new verity root: %v", err) + } + defer cleanup() + + filename := "verity-test-file" + if _, _, err := newFileFD(ctx, vfsObj, root, filename, 0644); err != nil { + t.Fatalf("Failed to create new file fd: %v", err) + } + + // Ensure that the corresponding Merkle tree file is created. + lowerRoot := root.Dentry().Impl().(*dentry).lowerVD + if _, err = vfsObj.OpenAt(ctx, auth.CredentialsFromContext(ctx), &vfs.PathOperation{ + Root: lowerRoot, + Start: lowerRoot, + Path: fspath.Parse(merklePrefix + filename), + }, &vfs.OpenOptions{ + Flags: linux.O_RDONLY, + }); err != nil { + t.Errorf("Failed to open Merkle tree file %s: %v", merklePrefix+filename, err) + } + + // Ensure the root merkle tree file is created. + if _, err = vfsObj.OpenAt(ctx, auth.CredentialsFromContext(ctx), &vfs.PathOperation{ + Root: lowerRoot, + Start: lowerRoot, + Path: fspath.Parse(merklePrefix + rootMerkleFilename), + }, &vfs.OpenOptions{ + Flags: linux.O_RDONLY, + }); err != nil { + t.Errorf("Failed to open root Merkle tree file %s: %v", merklePrefix+rootMerkleFilename, err) + } +} + +// TestUntouchedFileSucceeds ensures that read from an untouched verity file +// succeeds after enabling verity for it. +func TestReadUntouchedFileSucceeds(t *testing.T) { + ctx := contexttest.Context(t) + vfsObj, root, cleanup, err := newVerityRoot(ctx) + if err != nil { + t.Fatalf("Failed to create new verity root: %v", err) + } + defer cleanup() + + filename := "verity-test-file" + fd, size, err := newFileFD(ctx, vfsObj, root, filename, 0644) + if err != nil { + t.Fatalf("Failed to create new file fd: %v", err) + } + + // Enable verity on the file and confirm a normal read succeeds. + var args arch.SyscallArguments + args[1] = arch.SyscallArgument{Value: linux.FS_IOC_ENABLE_VERITY} + if _, err := fd.Ioctl(ctx, nil /* uio */, args); err != nil { + t.Fatalf("Ioctl failed: %v", err) + } + + buf := make([]byte, size) + n, err := fd.PRead(ctx, usermem.BytesIOSequence(buf), 0 /* offset */, vfs.ReadOptions{}) + if err != nil && err != io.EOF { + t.Fatalf("fd.PRead failed: %v", err) + } + + if n != int64(size) { + t.Errorf("fd.PRead got read length %d, want %d", n, size) + } +} + +// TestReopenUntouchedFileSucceeds ensures that reopen an untouched verity file +// succeeds after enabling verity for it. +func TestReopenUntouchedFileSucceeds(t *testing.T) { + ctx := contexttest.Context(t) + vfsObj, root, cleanup, err := newVerityRoot(ctx) + if err != nil { + t.Fatalf("Failed to create new verity root: %v", err) + } + defer cleanup() + + filename := "verity-test-file" + fd, _, err := newFileFD(ctx, vfsObj, root, filename, 0644) + if err != nil { + t.Fatalf("Failed to create new file fd: %v", err) + } + + // Enable verity on the file and confirms a normal read succeeds. + var args arch.SyscallArguments + args[1] = arch.SyscallArgument{Value: linux.FS_IOC_ENABLE_VERITY} + if _, err := fd.Ioctl(ctx, nil /* uio */, args); err != nil { + t.Fatalf("Ioctl failed: %v", err) + } + + // Ensure reopening the verity enabled file succeeds. + if _, err = vfsObj.OpenAt(ctx, auth.CredentialsFromContext(ctx), &vfs.PathOperation{ + Root: root, + Start: root, + Path: fspath.Parse(filename), + }, &vfs.OpenOptions{ + Flags: linux.O_RDONLY, + Mode: linux.ModeRegular, + }); err != nil { + t.Errorf("reopen enabled file failed: %v", err) + } +} + +// TestModifiedFileFails ensures that read from a modified verity file fails. +func TestModifiedFileFails(t *testing.T) { + ctx := contexttest.Context(t) + vfsObj, root, cleanup, err := newVerityRoot(ctx) + if err != nil { + t.Fatalf("Failed to create new verity root: %v", err) + } + defer cleanup() + + filename := "verity-test-file" + fd, size, err := newFileFD(ctx, vfsObj, root, filename, 0644) + if err != nil { + t.Fatalf("Failed to create new file fd: %v", err) + } + + // Enable verity on the file. + var args arch.SyscallArguments + args[1] = arch.SyscallArgument{Value: linux.FS_IOC_ENABLE_VERITY} + if _, err := fd.Ioctl(ctx, nil /* uio */, args); err != nil { + t.Fatalf("Ioctl failed: %v", err) + } + + // Open a new lowerFD that's read/writable. + lowerVD := fd.Impl().(*fileDescription).d.lowerVD + + lowerFD, err := vfsObj.OpenAt(ctx, auth.CredentialsFromContext(ctx), &vfs.PathOperation{ + Root: lowerVD, + Start: lowerVD, + }, &vfs.OpenOptions{ + Flags: linux.O_RDWR, + }) + if err != nil { + t.Fatalf("Open lowerFD failed: %v", err) + } + + if err := corruptRandomBit(ctx, lowerFD, size); err != nil { + t.Fatalf("%v", err) + } + + // Confirm that read from the modified file fails. + buf := make([]byte, size) + if _, err := fd.PRead(ctx, usermem.BytesIOSequence(buf), 0 /* offset */, vfs.ReadOptions{}); err == nil { + t.Fatalf("fd.PRead succeeded with modified file") + } +} + +// TestModifiedMerkleFails ensures that read from a verity file fails if the +// corresponding Merkle tree file is modified. +func TestModifiedMerkleFails(t *testing.T) { + ctx := contexttest.Context(t) + vfsObj, root, cleanup, err := newVerityRoot(ctx) + if err != nil { + t.Fatalf("Failed to create new verity root: %v", err) + } + defer cleanup() + + filename := "verity-test-file" + fd, size, err := newFileFD(ctx, vfsObj, root, filename, 0644) + if err != nil { + t.Fatalf("Failed to create new file fd: %v", err) + } + + // Enable verity on the file. + var args arch.SyscallArguments + args[1] = arch.SyscallArgument{Value: linux.FS_IOC_ENABLE_VERITY} + if _, err := fd.Ioctl(ctx, nil /* uio */, args); err != nil { + t.Fatalf("Ioctl failed: %v", err) + } + + // Open a new lowerMerkleFD that's read/writable. + lowerMerkleVD := fd.Impl().(*fileDescription).d.lowerMerkleVD + + lowerMerkleFD, err := vfsObj.OpenAt(ctx, auth.CredentialsFromContext(ctx), &vfs.PathOperation{ + Root: lowerMerkleVD, + Start: lowerMerkleVD, + }, &vfs.OpenOptions{ + Flags: linux.O_RDWR, + }) + if err != nil { + t.Fatalf("Open lowerMerkleFD failed: %v", err) + } + + // Flip a random bit in the Merkle tree file. + stat, err := lowerMerkleFD.Stat(ctx, vfs.StatOptions{}) + if err != nil { + t.Fatalf("Failed to get lowerMerkleFD stat: %v", err) + } + merkleSize := int(stat.Size) + if err := corruptRandomBit(ctx, lowerMerkleFD, merkleSize); err != nil { + t.Fatalf("%v", err) + } + + // Confirm that read from a file with modified Merkle tree fails. + buf := make([]byte, size) + if _, err := fd.PRead(ctx, usermem.BytesIOSequence(buf), 0 /* offset */, vfs.ReadOptions{}); err == nil { + fmt.Println(buf) + t.Fatalf("fd.PRead succeeded with modified Merkle file") + } +} diff --git a/pkg/sentry/inet/BUILD b/pkg/sentry/inet/BUILD index 07bf39fed..5bba9de0b 100644 --- a/pkg/sentry/inet/BUILD +++ b/pkg/sentry/inet/BUILD @@ -15,6 +15,7 @@ go_library( ], deps = [ "//pkg/context", + "//pkg/tcpip", "//pkg/tcpip/stack", ], ) diff --git a/pkg/sentry/inet/inet.go b/pkg/sentry/inet/inet.go index c0b4831d1..fbe6d6aa6 100644 --- a/pkg/sentry/inet/inet.go +++ b/pkg/sentry/inet/inet.go @@ -15,7 +15,10 @@ // Package inet defines semantics for IP stacks. package inet -import "gvisor.dev/gvisor/pkg/tcpip/stack" +import ( + "gvisor.dev/gvisor/pkg/tcpip" + "gvisor.dev/gvisor/pkg/tcpip/stack" +) // Stack represents a TCP/IP stack. type Stack interface { @@ -80,6 +83,12 @@ type Stack interface { // RestoreCleanupEndpoints adds endpoints to cleanup tracking. This is useful // for restoring a stack after a save. RestoreCleanupEndpoints([]stack.TransportEndpoint) + + // Forwarding returns if packet forwarding between NICs is enabled. + Forwarding(protocol tcpip.NetworkProtocolNumber) bool + + // SetForwarding enables or disables packet forwarding between NICs. + SetForwarding(protocol tcpip.NetworkProtocolNumber, enable bool) error } // Interface contains information about a network interface. diff --git a/pkg/sentry/inet/test_stack.go b/pkg/sentry/inet/test_stack.go index 9771f01fc..1779cc6f3 100644 --- a/pkg/sentry/inet/test_stack.go +++ b/pkg/sentry/inet/test_stack.go @@ -14,7 +14,10 @@ package inet -import "gvisor.dev/gvisor/pkg/tcpip/stack" +import ( + "gvisor.dev/gvisor/pkg/tcpip" + "gvisor.dev/gvisor/pkg/tcpip/stack" +) // TestStack is a dummy implementation of Stack for tests. type TestStack struct { @@ -26,6 +29,7 @@ type TestStack struct { TCPSendBufSize TCPBufferSize TCPSACKFlag bool Recovery TCPLossRecovery + IPForwarding bool } // NewTestStack returns a TestStack with no network interfaces. The value of @@ -128,3 +132,14 @@ func (s *TestStack) CleanupEndpoints() []stack.TransportEndpoint { // RestoreCleanupEndpoints implements inet.Stack.RestoreCleanupEndpoints. func (s *TestStack) RestoreCleanupEndpoints([]stack.TransportEndpoint) {} + +// Forwarding implements inet.Stack.Forwarding. +func (s *TestStack) Forwarding(protocol tcpip.NetworkProtocolNumber) bool { + return s.IPForwarding +} + +// SetForwarding implements inet.Stack.SetForwarding. +func (s *TestStack) SetForwarding(protocol tcpip.NetworkProtocolNumber, enable bool) error { + s.IPForwarding = enable + return nil +} diff --git a/pkg/sentry/kernel/BUILD b/pkg/sentry/kernel/BUILD index d436daab4..083071b5e 100644 --- a/pkg/sentry/kernel/BUILD +++ b/pkg/sentry/kernel/BUILD @@ -69,8 +69,8 @@ go_template_instance( prefix = "socket", template = "//pkg/ilist:generic_list", types = { - "Element": "*SocketEntry", - "Linker": "*SocketEntry", + "Element": "*SocketRecordVFS1", + "Linker": "*SocketRecordVFS1", }, ) @@ -197,6 +197,7 @@ go_library( "gvisor.dev/gvisor/pkg/sentry/device", "gvisor.dev/gvisor/pkg/tcpip", ], + marshal = True, visibility = ["//:sandbox"], deps = [ ":uncaught_signal_go_proto", @@ -212,6 +213,8 @@ go_library( "//pkg/eventchannel", "//pkg/fspath", "//pkg/log", + "//pkg/marshal", + "//pkg/marshal/primitive", "//pkg/metric", "//pkg/refs", "//pkg/refs_vfs2", @@ -261,7 +264,6 @@ go_library( "//pkg/tcpip/stack", "//pkg/usermem", "//pkg/waiter", - "//tools/go_marshal/marshal", ], ) diff --git a/pkg/sentry/kernel/auth/BUILD b/pkg/sentry/kernel/auth/BUILD index 2bc49483a..869e49ebc 100644 --- a/pkg/sentry/kernel/auth/BUILD +++ b/pkg/sentry/kernel/auth/BUILD @@ -57,6 +57,7 @@ go_library( "id_map_set.go", "user_namespace.go", ], + marshal = True, visibility = ["//pkg/sentry:internal"], deps = [ "//pkg/abi/linux", diff --git a/pkg/sentry/kernel/auth/id.go b/pkg/sentry/kernel/auth/id.go index 0a58ba17c..4c32ee703 100644 --- a/pkg/sentry/kernel/auth/id.go +++ b/pkg/sentry/kernel/auth/id.go @@ -19,9 +19,13 @@ import ( ) // UID is a user ID in an unspecified user namespace. +// +// +marshal type UID uint32 // GID is a group ID in an unspecified user namespace. +// +// +marshal slice:GIDSlice type GID uint32 // In the root user namespace, user/group IDs have a 1-to-1 relationship with diff --git a/pkg/sentry/kernel/fd_table.go b/pkg/sentry/kernel/fd_table.go index 5773244ac..0ec7344cd 100644 --- a/pkg/sentry/kernel/fd_table.go +++ b/pkg/sentry/kernel/fd_table.go @@ -111,8 +111,11 @@ func (f *FDTable) saveDescriptorTable() map[int32]descriptor { func (f *FDTable) loadDescriptorTable(m map[int32]descriptor) { ctx := context.Background() f.init() // Initialize table. + f.used = 0 for fd, d := range m { - f.setAll(fd, d.file, d.fileVFS2, d.flags) + if file, fileVFS2 := f.setAll(ctx, fd, d.file, d.fileVFS2, d.flags); file != nil || fileVFS2 != nil { + panic("VFS1 or VFS2 files set") + } // Note that we do _not_ need to acquire a extra table reference here. The // table reference will already be accounted for in the file, so we drop the @@ -127,7 +130,7 @@ func (f *FDTable) loadDescriptorTable(m map[int32]descriptor) { } // drop drops the table reference. -func (f *FDTable) drop(file *fs.File) { +func (f *FDTable) drop(ctx context.Context, file *fs.File) { // Release locks. file.Dirent.Inode.LockCtx.Posix.UnlockRegion(f, lock.LockRange{0, lock.LockEOF}) @@ -145,14 +148,13 @@ func (f *FDTable) drop(file *fs.File) { d.InotifyEvent(ev, 0) // Drop the table reference. - file.DecRef(context.Background()) + file.DecRef(ctx) } // dropVFS2 drops the table reference. -func (f *FDTable) dropVFS2(file *vfs.FileDescription) { +func (f *FDTable) dropVFS2(ctx context.Context, file *vfs.FileDescription) { // Release any POSIX lock possibly held by the FDTable. Range {0, 0} means the // entire file. - ctx := context.Background() err := file.UnlockPOSIX(ctx, f, 0, 0, linux.SEEK_SET) if err != nil && err != syserror.ENOLCK { panic(fmt.Sprintf("UnlockPOSIX failed: %v", err)) @@ -187,12 +189,6 @@ func (f *FDTable) DecRef(ctx context.Context) { }) } -// Size returns the number of file descriptor slots currently allocated. -func (f *FDTable) Size() int { - size := atomic.LoadInt32(&f.used) - return int(size) -} - // forEach iterates over all non-nil files in sorted order. // // It is the caller's responsibility to acquire an appropriate lock. @@ -279,7 +275,6 @@ func (f *FDTable) NewFDs(ctx context.Context, fd int32, files []*fs.File, flags } f.mu.Lock() - defer f.mu.Unlock() // From f.next to find available fd. if fd < f.next { @@ -289,15 +284,25 @@ func (f *FDTable) NewFDs(ctx context.Context, fd int32, files []*fs.File, flags // Install all entries. for i := fd; i < end && len(fds) < len(files); i++ { if d, _, _ := f.get(i); d == nil { - f.set(i, files[len(fds)], flags) // Set the descriptor. - fds = append(fds, i) // Record the file descriptor. + // Set the descriptor. + f.set(ctx, i, files[len(fds)], flags) + fds = append(fds, i) // Record the file descriptor. } } // Failure? Unwind existing FDs. if len(fds) < len(files) { for _, i := range fds { - f.set(i, nil, FDFlags{}) // Zap entry. + f.set(ctx, i, nil, FDFlags{}) + } + f.mu.Unlock() + + // Drop the reference taken by the call to f.set() that + // originally installed the file. Don't call f.drop() + // (generating inotify events, etc.) since the file should + // appear to have never been inserted into f. + for _, file := range files[:len(fds)] { + file.DecRef(ctx) } return nil, syscall.EMFILE } @@ -307,6 +312,7 @@ func (f *FDTable) NewFDs(ctx context.Context, fd int32, files []*fs.File, flags f.next = fds[len(fds)-1] + 1 } + f.mu.Unlock() return fds, nil } @@ -334,7 +340,6 @@ func (f *FDTable) NewFDsVFS2(ctx context.Context, fd int32, files []*vfs.FileDes } f.mu.Lock() - defer f.mu.Unlock() // From f.next to find available fd. if fd < f.next { @@ -344,15 +349,25 @@ func (f *FDTable) NewFDsVFS2(ctx context.Context, fd int32, files []*vfs.FileDes // Install all entries. for i := fd; i < end && len(fds) < len(files); i++ { if d, _, _ := f.getVFS2(i); d == nil { - f.setVFS2(i, files[len(fds)], flags) // Set the descriptor. - fds = append(fds, i) // Record the file descriptor. + // Set the descriptor. + f.setVFS2(ctx, i, files[len(fds)], flags) + fds = append(fds, i) // Record the file descriptor. } } // Failure? Unwind existing FDs. if len(fds) < len(files) { for _, i := range fds { - f.setVFS2(i, nil, FDFlags{}) // Zap entry. + f.setVFS2(ctx, i, nil, FDFlags{}) + } + f.mu.Unlock() + + // Drop the reference taken by the call to f.setVFS2() that + // originally installed the file. Don't call f.dropVFS2() + // (generating inotify events, etc.) since the file should + // appear to have never been inserted into f. + for _, file := range files[:len(fds)] { + file.DecRef(ctx) } return nil, syscall.EMFILE } @@ -362,6 +377,7 @@ func (f *FDTable) NewFDsVFS2(ctx context.Context, fd int32, files []*vfs.FileDes f.next = fds[len(fds)-1] + 1 } + f.mu.Unlock() return fds, nil } @@ -397,7 +413,7 @@ func (f *FDTable) NewFDVFS2(ctx context.Context, minfd int32, file *vfs.FileDesc } for fd < end { if d, _, _ := f.getVFS2(fd); d == nil { - f.setVFS2(fd, file, flags) + f.setVFS2(ctx, fd, file, flags) if fd == f.next { // Update next search start position. f.next = fd + 1 @@ -413,40 +429,55 @@ func (f *FDTable) NewFDVFS2(ctx context.Context, minfd int32, file *vfs.FileDesc // reference for that FD, the ref count for that existing reference is // decremented. func (f *FDTable) NewFDAt(ctx context.Context, fd int32, file *fs.File, flags FDFlags) error { - return f.newFDAt(ctx, fd, file, nil, flags) + df, _, err := f.newFDAt(ctx, fd, file, nil, flags) + if err != nil { + return err + } + if df != nil { + f.drop(ctx, df) + } + return nil } // NewFDAtVFS2 sets the file reference for the given FD. If there is an active // reference for that FD, the ref count for that existing reference is // decremented. func (f *FDTable) NewFDAtVFS2(ctx context.Context, fd int32, file *vfs.FileDescription, flags FDFlags) error { - return f.newFDAt(ctx, fd, nil, file, flags) + _, dfVFS2, err := f.newFDAt(ctx, fd, nil, file, flags) + if err != nil { + return err + } + if dfVFS2 != nil { + f.dropVFS2(ctx, dfVFS2) + } + return nil } -func (f *FDTable) newFDAt(ctx context.Context, fd int32, file *fs.File, fileVFS2 *vfs.FileDescription, flags FDFlags) error { +func (f *FDTable) newFDAt(ctx context.Context, fd int32, file *fs.File, fileVFS2 *vfs.FileDescription, flags FDFlags) (*fs.File, *vfs.FileDescription, error) { if fd < 0 { // Don't accept negative FDs. - return syscall.EBADF + return nil, nil, syscall.EBADF } // Check the limit for the provided file. if limitSet := limits.FromContext(ctx); limitSet != nil { if lim := limitSet.Get(limits.NumberOfFiles); lim.Cur != limits.Infinity && uint64(fd) >= lim.Cur { - return syscall.EMFILE + return nil, nil, syscall.EMFILE } } // Install the entry. f.mu.Lock() defer f.mu.Unlock() - f.setAll(fd, file, fileVFS2, flags) - return nil + + df, dfVFS2 := f.setAll(ctx, fd, file, fileVFS2, flags) + return df, dfVFS2, nil } // SetFlags sets the flags for the given file descriptor. // // True is returned iff flags were changed. -func (f *FDTable) SetFlags(fd int32, flags FDFlags) error { +func (f *FDTable) SetFlags(ctx context.Context, fd int32, flags FDFlags) error { if fd < 0 { // Don't accept negative FDs. return syscall.EBADF @@ -462,14 +493,14 @@ func (f *FDTable) SetFlags(fd int32, flags FDFlags) error { } // Update the flags. - f.set(fd, file, flags) + f.set(ctx, fd, file, flags) return nil } // SetFlagsVFS2 sets the flags for the given file descriptor. // // True is returned iff flags were changed. -func (f *FDTable) SetFlagsVFS2(fd int32, flags FDFlags) error { +func (f *FDTable) SetFlagsVFS2(ctx context.Context, fd int32, flags FDFlags) error { if fd < 0 { // Don't accept negative FDs. return syscall.EBADF @@ -485,7 +516,7 @@ func (f *FDTable) SetFlagsVFS2(fd int32, flags FDFlags) error { } // Update the flags. - f.setVFS2(fd, file, flags) + f.setVFS2(ctx, fd, file, flags) return nil } @@ -551,30 +582,6 @@ func (f *FDTable) GetFDs(ctx context.Context) []int32 { return fds } -// GetRefs returns a stable slice of references to all files and bumps the -// reference count on each. The caller must use DecRef on each reference when -// they're done using the slice. -func (f *FDTable) GetRefs(ctx context.Context) []*fs.File { - files := make([]*fs.File, 0, f.Size()) - f.forEach(ctx, func(_ int32, file *fs.File, _ *vfs.FileDescription, _ FDFlags) { - file.IncRef() // Acquire a reference for caller. - files = append(files, file) - }) - return files -} - -// GetRefsVFS2 returns a stable slice of references to all files and bumps the -// reference count on each. The caller must use DecRef on each reference when -// they're done using the slice. -func (f *FDTable) GetRefsVFS2(ctx context.Context) []*vfs.FileDescription { - files := make([]*vfs.FileDescription, 0, f.Size()) - f.forEach(ctx, func(_ int32, _ *fs.File, file *vfs.FileDescription, _ FDFlags) { - file.IncRef() // Acquire a reference for caller. - files = append(files, file) - }) - return files -} - // Fork returns an independent FDTable. func (f *FDTable) Fork(ctx context.Context) *FDTable { clone := f.k.NewFDTable() @@ -582,11 +589,8 @@ func (f *FDTable) Fork(ctx context.Context) *FDTable { f.forEach(ctx, func(fd int32, file *fs.File, fileVFS2 *vfs.FileDescription, flags FDFlags) { // The set function here will acquire an appropriate table // reference for the clone. We don't need anything else. - switch { - case file != nil: - clone.set(fd, file, flags) - case fileVFS2 != nil: - clone.setVFS2(fd, fileVFS2, flags) + if df, dfVFS2 := clone.setAll(ctx, fd, file, fileVFS2, flags); df != nil || dfVFS2 != nil { + panic("VFS1 or VFS2 files set") } }) return clone @@ -595,13 +599,12 @@ func (f *FDTable) Fork(ctx context.Context) *FDTable { // Remove removes an FD from and returns a non-file iff successful. // // N.B. Callers are required to use DecRef when they are done. -func (f *FDTable) Remove(fd int32) (*fs.File, *vfs.FileDescription) { +func (f *FDTable) Remove(ctx context.Context, fd int32) (*fs.File, *vfs.FileDescription) { if fd < 0 { return nil, nil } f.mu.Lock() - defer f.mu.Unlock() // Update current available position. if fd < f.next { @@ -617,24 +620,51 @@ func (f *FDTable) Remove(fd int32) (*fs.File, *vfs.FileDescription) { case orig2 != nil: orig2.IncRef() } + if orig != nil || orig2 != nil { - f.setAll(fd, nil, nil, FDFlags{}) // Zap entry. + orig, orig2 = f.setAll(ctx, fd, nil, nil, FDFlags{}) // Zap entry. + } + f.mu.Unlock() + + if orig != nil { + f.drop(ctx, orig) } + if orig2 != nil { + f.dropVFS2(ctx, orig2) + } + return orig, orig2 } // RemoveIf removes all FDs where cond is true. func (f *FDTable) RemoveIf(ctx context.Context, cond func(*fs.File, *vfs.FileDescription, FDFlags) bool) { - f.mu.Lock() - defer f.mu.Unlock() + // TODO(gvisor.dev/issue/1624): Remove fs.File slice. + var files []*fs.File + var filesVFS2 []*vfs.FileDescription + f.mu.Lock() f.forEach(ctx, func(fd int32, file *fs.File, fileVFS2 *vfs.FileDescription, flags FDFlags) { if cond(file, fileVFS2, flags) { - f.set(fd, nil, FDFlags{}) // Clear from table. + df, dfVFS2 := f.setAll(ctx, fd, nil, nil, FDFlags{}) // Clear from table. + if df != nil { + files = append(files, df) + } + if dfVFS2 != nil { + filesVFS2 = append(filesVFS2, dfVFS2) + } // Update current available position. if fd < f.next { f.next = fd } } }) + f.mu.Unlock() + + for _, file := range files { + f.drop(ctx, file) + } + + for _, file := range filesVFS2 { + f.dropVFS2(ctx, file) + } } diff --git a/pkg/sentry/kernel/fd_table_test.go b/pkg/sentry/kernel/fd_table_test.go index e3f30ba2a..bf5460083 100644 --- a/pkg/sentry/kernel/fd_table_test.go +++ b/pkg/sentry/kernel/fd_table_test.go @@ -72,7 +72,7 @@ func TestFDTableMany(t *testing.T) { } i := int32(2) - fdTable.Remove(i) + fdTable.Remove(ctx, i) if fds, err := fdTable.NewFDs(ctx, 0, []*fs.File{file}, FDFlags{}); err != nil || fds[0] != i { t.Fatalf("Allocated %v FDs but wanted to allocate %v: %v", i, maxFD, err) } @@ -93,7 +93,7 @@ func TestFDTableOverLimit(t *testing.T) { t.Fatalf("fdTable.NewFDs(maxFD-3, {f,f,f}): got %v, wanted nil", err) } else { for _, fd := range fds { - fdTable.Remove(fd) + fdTable.Remove(ctx, fd) } } @@ -150,13 +150,13 @@ func TestFDTable(t *testing.T) { t.Fatalf("fdTable.Get(2): got a %v, wanted nil", ref) } - ref, _ := fdTable.Remove(1) + ref, _ := fdTable.Remove(ctx, 1) if ref == nil { t.Fatalf("fdTable.Remove(1) for an existing FD: failed, want success") } ref.DecRef(ctx) - if ref, _ := fdTable.Remove(1); ref != nil { + if ref, _ := fdTable.Remove(ctx, 1); ref != nil { t.Fatalf("r.Remove(1) for a removed FD: got success, want failure") } }) diff --git a/pkg/sentry/kernel/fd_table_unsafe.go b/pkg/sentry/kernel/fd_table_unsafe.go index 6b8feb107..da79e6627 100644 --- a/pkg/sentry/kernel/fd_table_unsafe.go +++ b/pkg/sentry/kernel/fd_table_unsafe.go @@ -18,6 +18,7 @@ import ( "sync/atomic" "unsafe" + "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/vfs" ) @@ -78,33 +79,37 @@ func (f *FDTable) getAll(fd int32) (*fs.File, *vfs.FileDescription, FDFlags, boo return d.file, d.fileVFS2, d.flags, true } -// set sets an entry. -// -// This handles accounting changes, as well as acquiring and releasing the -// reference needed by the table iff the file is different. +// CurrentMaxFDs returns the number of file descriptors that may be stored in f +// without reallocation. +func (f *FDTable) CurrentMaxFDs() int { + slice := *(*[]unsafe.Pointer)(atomic.LoadPointer(&f.slice)) + return len(slice) +} + +// set sets an entry for VFS1, refer to setAll(). // // Precondition: mu must be held. -func (f *FDTable) set(fd int32, file *fs.File, flags FDFlags) { - f.setAll(fd, file, nil, flags) +func (f *FDTable) set(ctx context.Context, fd int32, file *fs.File, flags FDFlags) *fs.File { + dropFile, _ := f.setAll(ctx, fd, file, nil, flags) + return dropFile } -// setVFS2 sets an entry. -// -// This handles accounting changes, as well as acquiring and releasing the -// reference needed by the table iff the file is different. +// setVFS2 sets an entry for VFS2, refer to setAll(). // // Precondition: mu must be held. -func (f *FDTable) setVFS2(fd int32, file *vfs.FileDescription, flags FDFlags) { - f.setAll(fd, nil, file, flags) +func (f *FDTable) setVFS2(ctx context.Context, fd int32, file *vfs.FileDescription, flags FDFlags) *vfs.FileDescription { + _, dropFile := f.setAll(ctx, fd, nil, file, flags) + return dropFile } -// setAll sets an entry. -// -// This handles accounting changes, as well as acquiring and releasing the -// reference needed by the table iff the file is different. +// setAll sets the file description referred to by fd to file/fileVFS2. If +// file/fileVFS2 are non-nil, it takes a reference on them. If setAll replaces +// an existing file description, it returns it with the FDTable's reference +// transferred to the caller, which must call f.drop/dropVFS2() on the returned +// file after unlocking f.mu. // // Precondition: mu must be held. -func (f *FDTable) setAll(fd int32, file *fs.File, fileVFS2 *vfs.FileDescription, flags FDFlags) { +func (f *FDTable) setAll(ctx context.Context, fd int32, file *fs.File, fileVFS2 *vfs.FileDescription, flags FDFlags) (*fs.File, *vfs.FileDescription) { if file != nil && fileVFS2 != nil { panic("VFS1 and VFS2 files set") } @@ -147,25 +152,25 @@ func (f *FDTable) setAll(fd int32, file *fs.File, fileVFS2 *vfs.FileDescription, } } - // Drop the table reference. + // Adjust used. + switch { + case orig == nil && desc != nil: + atomic.AddInt32(&f.used, 1) + case orig != nil && desc == nil: + atomic.AddInt32(&f.used, -1) + } + if orig != nil { switch { case orig.file != nil: if desc == nil || desc.file != orig.file { - f.drop(orig.file) + return orig.file, nil } case orig.fileVFS2 != nil: if desc == nil || desc.fileVFS2 != orig.fileVFS2 { - f.dropVFS2(orig.fileVFS2) + return nil, orig.fileVFS2 } } } - - // Adjust used. - switch { - case orig == nil && desc != nil: - atomic.AddInt32(&f.used, 1) - case orig != nil && desc == nil: - atomic.AddInt32(&f.used, -1) - } + return nil, nil } diff --git a/pkg/sentry/kernel/kcov.go b/pkg/sentry/kernel/kcov.go index aad63aa99..d3e76ca7b 100644 --- a/pkg/sentry/kernel/kcov.go +++ b/pkg/sentry/kernel/kcov.go @@ -89,6 +89,10 @@ func (kcov *Kcov) TaskWork(t *Task) { kcov.mu.Lock() defer kcov.mu.Unlock() + if kcov.mode != linux.KCOV_TRACE_PC { + return + } + rw := &kcovReadWriter{ mf: kcov.mfp.MemoryFile(), fr: kcov.mappable.FileRange(), diff --git a/pkg/sentry/kernel/kernel.go b/pkg/sentry/kernel/kernel.go index 402aa1718..d6c21adb7 100644 --- a/pkg/sentry/kernel/kernel.go +++ b/pkg/sentry/kernel/kernel.go @@ -220,13 +220,18 @@ type Kernel struct { // danglingEndpoints is used to save / restore tcpip.DanglingEndpoints. danglingEndpoints struct{} `state:".([]tcpip.Endpoint)"` - // sockets is the list of all network sockets the system. Protected by - // extMu. + // sockets is the list of all network sockets in the system. + // Protected by extMu. + // TODO(gvisor.dev/issue/1624): Only used by VFS1. sockets socketList - // nextSocketEntry is the next entry number to use in sockets. Protected + // socketsVFS2 records all network sockets in the system. Protected by + // extMu. + socketsVFS2 map[*vfs.FileDescription]*SocketRecord + + // nextSocketRecord is the next entry number to use in sockets. Protected // by extMu. - nextSocketEntry uint64 + nextSocketRecord uint64 // deviceRegistry is used to save/restore device.SimpleDevices. deviceRegistry struct{} `state:".(*device.Registry)"` @@ -414,6 +419,8 @@ func (k *Kernel) Init(args InitKernelArgs) error { return fmt.Errorf("failed to create sockfs mount: %v", err) } k.socketMount = socketMount + + k.socketsVFS2 = make(map[*vfs.FileDescription]*SocketRecord) } return nil @@ -507,6 +514,10 @@ func (k *Kernel) SaveTo(w wire.Writer) error { // flushMountSourceRefs flushes the MountSources for all mounted filesystems // and open FDs. func (k *Kernel) flushMountSourceRefs(ctx context.Context) error { + if VFS2Enabled { + return nil // Not relevant. + } + // Flush all mount sources for currently mounted filesystems in each task. flushed := make(map[*fs.MountNamespace]struct{}) k.tasks.mu.RLock() @@ -533,11 +544,6 @@ func (k *Kernel) flushMountSourceRefs(ctx context.Context) error { // // Precondition: Must be called with the kernel paused. func (ts *TaskSet) forEachFDPaused(ctx context.Context, f func(*fs.File, *vfs.FileDescription) error) (err error) { - // TODO(gvisor.dev/issue/1663): Add save support for VFS2. - if VFS2Enabled { - return nil - } - ts.mu.RLock() defer ts.mu.RUnlock() for t := range ts.Root.tids { @@ -556,6 +562,10 @@ func (ts *TaskSet) forEachFDPaused(ctx context.Context, f func(*fs.File, *vfs.Fi func (ts *TaskSet) flushWritesToFiles(ctx context.Context) error { // TODO(gvisor.dev/issue/1663): Add save support for VFS2. + if VFS2Enabled { + return nil + } + return ts.forEachFDPaused(ctx, func(file *fs.File, _ *vfs.FileDescription) error { if flags := file.Flags(); !flags.Write { return nil @@ -888,17 +898,18 @@ func (k *Kernel) CreateProcess(args CreateProcessArgs) (*ThreadGroup, ThreadID, opener fsbridge.Lookup fsContext *FSContext mntns *fs.MountNamespace + mntnsVFS2 *vfs.MountNamespace ) if VFS2Enabled { - mntnsVFS2 := args.MountNamespaceVFS2 + mntnsVFS2 = args.MountNamespaceVFS2 if mntnsVFS2 == nil { // MountNamespaceVFS2 adds a reference to the namespace, which is // transferred to the new process. mntnsVFS2 = k.globalInit.Leader().MountNamespaceVFS2() } // Get the root directory from the MountNamespace. - root := args.MountNamespaceVFS2.Root() + root := mntnsVFS2.Root() // The call to newFSContext below will take a reference on root, so we // don't need to hold this one. defer root.DecRef(ctx) @@ -1008,7 +1019,7 @@ func (k *Kernel) CreateProcess(args CreateProcessArgs) (*ThreadGroup, ThreadID, UTSNamespace: args.UTSNamespace, IPCNamespace: args.IPCNamespace, AbstractSocketNamespace: args.AbstractSocketNamespace, - MountNamespaceVFS2: args.MountNamespaceVFS2, + MountNamespaceVFS2: mntnsVFS2, ContainerID: args.ContainerID, } t, err := k.tasks.NewTask(config) @@ -1508,20 +1519,27 @@ func (k *Kernel) SupervisorContext() context.Context { } } -// SocketEntry represents a socket recorded in Kernel.sockets. It implements +// SocketRecord represents a socket recorded in Kernel.socketsVFS2. +// +// +stateify savable +type SocketRecord struct { + k *Kernel + Sock *refs.WeakRef // TODO(gvisor.dev/issue/1624): Only used by VFS1. + SockVFS2 *vfs.FileDescription // Only used by VFS2. + ID uint64 // Socket table entry number. +} + +// SocketRecordVFS1 represents a socket recorded in Kernel.sockets. It implements // refs.WeakRefUser for sockets stored in the socket table. // // +stateify savable -type SocketEntry struct { +type SocketRecordVFS1 struct { socketEntry - k *Kernel - Sock *refs.WeakRef - SockVFS2 *vfs.FileDescription - ID uint64 // Socket table entry number. + SocketRecord } // WeakRefGone implements refs.WeakRefUser.WeakRefGone. -func (s *SocketEntry) WeakRefGone(context.Context) { +func (s *SocketRecordVFS1) WeakRefGone(context.Context) { s.k.extMu.Lock() s.k.sockets.Remove(s) s.k.extMu.Unlock() @@ -1532,9 +1550,14 @@ func (s *SocketEntry) WeakRefGone(context.Context) { // Precondition: Caller must hold a reference to sock. func (k *Kernel) RecordSocket(sock *fs.File) { k.extMu.Lock() - id := k.nextSocketEntry - k.nextSocketEntry++ - s := &SocketEntry{k: k, ID: id} + id := k.nextSocketRecord + k.nextSocketRecord++ + s := &SocketRecordVFS1{ + SocketRecord: SocketRecord{ + k: k, + ID: id, + }, + } s.Sock = refs.NewWeakRef(sock, s) k.sockets.PushBack(s) k.extMu.Unlock() @@ -1546,29 +1569,45 @@ func (k *Kernel) RecordSocket(sock *fs.File) { // Precondition: Caller must hold a reference to sock. // // Note that the socket table will not hold a reference on the -// vfs.FileDescription, because we do not support weak refs on VFS2 files. +// vfs.FileDescription. func (k *Kernel) RecordSocketVFS2(sock *vfs.FileDescription) { k.extMu.Lock() - id := k.nextSocketEntry - k.nextSocketEntry++ - s := &SocketEntry{ + if _, ok := k.socketsVFS2[sock]; ok { + panic(fmt.Sprintf("Socket %p added twice", sock)) + } + id := k.nextSocketRecord + k.nextSocketRecord++ + s := &SocketRecord{ k: k, ID: id, SockVFS2: sock, } - k.sockets.PushBack(s) + k.socketsVFS2[sock] = s + k.extMu.Unlock() +} + +// DeleteSocketVFS2 removes a VFS2 socket from the system-wide socket table. +func (k *Kernel) DeleteSocketVFS2(sock *vfs.FileDescription) { + k.extMu.Lock() + delete(k.socketsVFS2, sock) k.extMu.Unlock() } // ListSockets returns a snapshot of all sockets. // -// Callers of ListSockets() in VFS2 should use SocketEntry.SockVFS2.TryIncRef() +// Callers of ListSockets() in VFS2 should use SocketRecord.SockVFS2.TryIncRef() // to get a reference on a socket in the table. -func (k *Kernel) ListSockets() []*SocketEntry { +func (k *Kernel) ListSockets() []*SocketRecord { k.extMu.Lock() - var socks []*SocketEntry - for s := k.sockets.Front(); s != nil; s = s.Next() { - socks = append(socks, s) + var socks []*SocketRecord + if VFS2Enabled { + for _, s := range k.socketsVFS2 { + socks = append(socks, s) + } + } else { + for s := k.sockets.Front(); s != nil; s = s.Next() { + socks = append(socks, &s.SocketRecord) + } } k.extMu.Unlock() return socks diff --git a/pkg/sentry/kernel/pipe/BUILD b/pkg/sentry/kernel/pipe/BUILD index 449643118..99134e634 100644 --- a/pkg/sentry/kernel/pipe/BUILD +++ b/pkg/sentry/kernel/pipe/BUILD @@ -21,6 +21,7 @@ go_library( "//pkg/amutex", "//pkg/buffer", "//pkg/context", + "//pkg/marshal/primitive", "//pkg/safemem", "//pkg/sentry/arch", "//pkg/sentry/device", diff --git a/pkg/sentry/kernel/pipe/pipe.go b/pkg/sentry/kernel/pipe/pipe.go index c410c96aa..67beb0ad6 100644 --- a/pkg/sentry/kernel/pipe/pipe.go +++ b/pkg/sentry/kernel/pipe/pipe.go @@ -17,6 +17,7 @@ package pipe import ( "fmt" + "io" "sync/atomic" "syscall" @@ -215,7 +216,7 @@ func (p *Pipe) readLocked(ctx context.Context, ops readOps) (int64, error) { if p.view.Size() == 0 { if !p.HasWriters() { // There are no writers, return EOF. - return 0, nil + return 0, io.EOF } return 0, syserror.ErrWouldBlock } diff --git a/pkg/sentry/kernel/pipe/pipe_util.go b/pkg/sentry/kernel/pipe/pipe_util.go index 6d58b682f..f665920cb 100644 --- a/pkg/sentry/kernel/pipe/pipe_util.go +++ b/pkg/sentry/kernel/pipe/pipe_util.go @@ -23,6 +23,7 @@ import ( "gvisor.dev/gvisor/pkg/amutex" "gvisor.dev/gvisor/pkg/buffer" "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/usermem" @@ -145,9 +146,14 @@ func (p *Pipe) Ioctl(ctx context.Context, io usermem.IO, args arch.SyscallArgume v = math.MaxInt32 // Silently truncate. } // Copy result to userspace. - _, err := usermem.CopyObjectOut(ctx, io, args[2].Pointer(), int32(v), usermem.IOOpts{ - AddressSpaceActive: true, - }) + iocc := primitive.IOCopyContext{ + IO: io, + Ctx: ctx, + Opts: usermem.IOOpts{ + AddressSpaceActive: true, + }, + } + _, err := primitive.CopyInt32Out(&iocc, args[2].Pointer(), int32(v)) return 0, err default: return 0, syscall.ENOTTY diff --git a/pkg/sentry/kernel/pipe/vfs.go b/pkg/sentry/kernel/pipe/vfs.go index f223d59e1..f61039f5b 100644 --- a/pkg/sentry/kernel/pipe/vfs.go +++ b/pkg/sentry/kernel/pipe/vfs.go @@ -67,6 +67,11 @@ func (vp *VFSPipe) ReaderWriterPair(mnt *vfs.Mount, vfsd *vfs.Dentry, statusFlag return vp.newFD(mnt, vfsd, linux.O_RDONLY|statusFlags, locks), vp.newFD(mnt, vfsd, linux.O_WRONLY|statusFlags, locks) } +// Allocate implements vfs.FileDescriptionImpl.Allocate. +func (*VFSPipe) Allocate(context.Context, uint64, uint64, uint64) error { + return syserror.ESPIPE +} + // Open opens the pipe represented by vp. func (vp *VFSPipe) Open(ctx context.Context, mnt *vfs.Mount, vfsd *vfs.Dentry, statusFlags uint32, locks *vfs.FileLocks) (*vfs.FileDescription, error) { vp.mu.Lock() diff --git a/pkg/sentry/kernel/ptrace.go b/pkg/sentry/kernel/ptrace.go index 50df179c3..1145faf13 100644 --- a/pkg/sentry/kernel/ptrace.go +++ b/pkg/sentry/kernel/ptrace.go @@ -18,6 +18,7 @@ import ( "fmt" "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/mm" "gvisor.dev/gvisor/pkg/syserror" @@ -999,18 +1000,15 @@ func (t *Task) Ptrace(req int64, pid ThreadID, addr, data usermem.Addr) error { // at the address specified by the data parameter, and the return value // is the error flag." - ptrace(2) word := t.Arch().Native(0) - if _, err := usermem.CopyObjectIn(t, target.MemoryManager(), addr, word, usermem.IOOpts{ - IgnorePermissions: true, - }); err != nil { + if _, err := word.CopyIn(target.AsCopyContext(usermem.IOOpts{IgnorePermissions: true}), addr); err != nil { return err } - _, err := t.CopyOut(data, word) + _, err := word.CopyOut(t, data) return err case linux.PTRACE_POKETEXT, linux.PTRACE_POKEDATA: - _, err := usermem.CopyObjectOut(t, target.MemoryManager(), addr, t.Arch().Native(uintptr(data)), usermem.IOOpts{ - IgnorePermissions: true, - }) + word := t.Arch().Native(uintptr(data)) + _, err := word.CopyOut(target.AsCopyContext(usermem.IOOpts{IgnorePermissions: true}), addr) return err case linux.PTRACE_GETREGSET: @@ -1078,12 +1076,12 @@ func (t *Task) Ptrace(req int64, pid ThreadID, addr, data usermem.Addr) error { if target.ptraceSiginfo == nil { return syserror.EINVAL } - _, err := t.CopyOut(data, target.ptraceSiginfo) + _, err := target.ptraceSiginfo.CopyOut(t, data) return err case linux.PTRACE_SETSIGINFO: var info arch.SignalInfo - if _, err := t.CopyIn(data, &info); err != nil { + if _, err := info.CopyIn(t, data); err != nil { return err } t.tg.pidns.owner.mu.RLock() @@ -1098,7 +1096,8 @@ func (t *Task) Ptrace(req int64, pid ThreadID, addr, data usermem.Addr) error { if addr != linux.SignalSetSize { return syserror.EINVAL } - _, err := t.CopyOut(data, target.SignalMask()) + mask := target.SignalMask() + _, err := mask.CopyOut(t, data) return err case linux.PTRACE_SETSIGMASK: @@ -1106,7 +1105,7 @@ func (t *Task) Ptrace(req int64, pid ThreadID, addr, data usermem.Addr) error { return syserror.EINVAL } var mask linux.SignalSet - if _, err := t.CopyIn(data, &mask); err != nil { + if _, err := mask.CopyIn(t, data); err != nil { return err } // The target's task goroutine is stopped, so this is safe: @@ -1121,7 +1120,7 @@ func (t *Task) Ptrace(req int64, pid ThreadID, addr, data usermem.Addr) error { case linux.PTRACE_GETEVENTMSG: t.tg.pidns.owner.mu.RLock() defer t.tg.pidns.owner.mu.RUnlock() - _, err := t.CopyOut(usermem.Addr(data), target.ptraceEventMsg) + _, err := primitive.CopyUint64Out(t, usermem.Addr(data), target.ptraceEventMsg) return err // PEEKSIGINFO is unimplemented but seems to have no users anywhere. diff --git a/pkg/sentry/kernel/ptrace_amd64.go b/pkg/sentry/kernel/ptrace_amd64.go index cef1276ec..609ad3941 100644 --- a/pkg/sentry/kernel/ptrace_amd64.go +++ b/pkg/sentry/kernel/ptrace_amd64.go @@ -30,7 +30,7 @@ func (t *Task) ptraceArch(target *Task, req int64, addr, data usermem.Addr) erro if err != nil { return err } - _, err = t.CopyOut(data, n) + _, err = n.CopyOut(t, data) return err case linux.PTRACE_POKEUSR: // aka PTRACE_POKEUSER diff --git a/pkg/sentry/kernel/syscalls.go b/pkg/sentry/kernel/syscalls.go index 413111faf..332bdb8e8 100644 --- a/pkg/sentry/kernel/syscalls.go +++ b/pkg/sentry/kernel/syscalls.go @@ -348,6 +348,16 @@ func (s *SyscallTable) LookupName(sysno uintptr) string { return fmt.Sprintf("sys_%d", sysno) // Unlikely. } +// LookupNo looks up a syscall number by name. +func (s *SyscallTable) LookupNo(name string) (uintptr, error) { + for i, syscall := range s.Table { + if syscall.Name == name { + return uintptr(i), nil + } + } + return 0, fmt.Errorf("syscall %q not found", name) +} + // LookupEmulate looks up an emulation syscall number. func (s *SyscallTable) LookupEmulate(addr usermem.Addr) (uintptr, bool) { sysno, ok := s.Emulate[addr] diff --git a/pkg/sentry/kernel/task_clone.go b/pkg/sentry/kernel/task_clone.go index 9d7a9128f..fce1064a7 100644 --- a/pkg/sentry/kernel/task_clone.go +++ b/pkg/sentry/kernel/task_clone.go @@ -341,12 +341,12 @@ func (t *Task) Clone(opts *CloneOptions) (ThreadID, *SyscallControl, error) { nt.SetClearTID(opts.ChildTID) } if opts.ChildSetTID { - // Can't use Task.CopyOut, which assumes AddressSpaceActive. - usermem.CopyObjectOut(t, nt.MemoryManager(), opts.ChildTID, nt.ThreadID(), usermem.IOOpts{}) + ctid := nt.ThreadID() + ctid.CopyOut(nt.AsCopyContext(usermem.IOOpts{AddressSpaceActive: false}), opts.ChildTID) } ntid := t.tg.pidns.IDOfTask(nt) if opts.ParentSetTID { - t.CopyOut(opts.ParentTID, ntid) + ntid.CopyOut(t, opts.ParentTID) } kind := ptraceCloneKindClone diff --git a/pkg/sentry/kernel/task_context.go b/pkg/sentry/kernel/task_context.go index 9fa528384..d1136461a 100644 --- a/pkg/sentry/kernel/task_context.go +++ b/pkg/sentry/kernel/task_context.go @@ -126,7 +126,11 @@ func (t *Task) SyscallTable() *SyscallTable { // Preconditions: The caller must be running on the task goroutine, or t.mu // must be locked. func (t *Task) Stack() *arch.Stack { - return &arch.Stack{t.Arch(), t.MemoryManager(), usermem.Addr(t.Arch().Stack())} + return &arch.Stack{ + Arch: t.Arch(), + IO: t.MemoryManager(), + Bottom: usermem.Addr(t.Arch().Stack()), + } } // LoadTaskImage loads a specified file into a new TaskContext. diff --git a/pkg/sentry/kernel/task_exit.go b/pkg/sentry/kernel/task_exit.go index b76f7f503..b400a8b41 100644 --- a/pkg/sentry/kernel/task_exit.go +++ b/pkg/sentry/kernel/task_exit.go @@ -248,7 +248,8 @@ func (*runExitMain) execute(t *Task) taskRunState { signaled := t.tg.exiting && t.tg.exitStatus.Signaled() t.tg.signalHandlers.mu.Unlock() if !signaled { - if _, err := t.CopyOut(t.cleartid, ThreadID(0)); err == nil { + zero := ThreadID(0) + if _, err := zero.CopyOut(t, t.cleartid); err == nil { t.Futex().Wake(t, t.cleartid, false, ^uint32(0), 1) } // If the CopyOut fails, there's nothing we can do. diff --git a/pkg/sentry/kernel/task_futex.go b/pkg/sentry/kernel/task_futex.go index 4b535c949..c80391475 100644 --- a/pkg/sentry/kernel/task_futex.go +++ b/pkg/sentry/kernel/task_futex.go @@ -16,6 +16,7 @@ package kernel import ( "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/kernel/futex" "gvisor.dev/gvisor/pkg/usermem" ) @@ -87,7 +88,7 @@ func (t *Task) exitRobustList() { return } - next := rl.List + next := primitive.Uint64(rl.List) done := 0 var pendingLockAddr usermem.Addr if rl.ListOpPending != 0 { @@ -99,12 +100,12 @@ func (t *Task) exitRobustList() { // We traverse to the next element of the list before we // actually wake anything. This prevents the race where waking // this futex causes a modification of the list. - thisLockAddr := usermem.Addr(next + rl.FutexOffset) + thisLockAddr := usermem.Addr(uint64(next) + rl.FutexOffset) // Try to decode the next element in the list before waking the // current futex. But don't check the error until after we've // woken the current futex. Linux does it in this order too - _, nextErr := t.CopyIn(usermem.Addr(next), &next) + _, nextErr := next.CopyIn(t, usermem.Addr(next)) // Wakeup the current futex if it's not pending. if thisLockAddr != pendingLockAddr { diff --git a/pkg/sentry/kernel/task_run.go b/pkg/sentry/kernel/task_run.go index aa3a573c0..8dc3fec90 100644 --- a/pkg/sentry/kernel/task_run.go +++ b/pkg/sentry/kernel/task_run.go @@ -141,7 +141,7 @@ func (*runApp) handleCPUIDInstruction(t *Task) error { region := trace.StartRegion(t.traceContext, cpuidRegion) expected := arch.CPUIDInstruction[:] found := make([]byte, len(expected)) - _, err := t.CopyIn(usermem.Addr(t.Arch().IP()), &found) + _, err := t.CopyInBytes(usermem.Addr(t.Arch().IP()), found) if err == nil && bytes.Equal(expected, found) { // Skip the cpuid instruction. t.Arch().CPUIDEmulate(t) diff --git a/pkg/sentry/kernel/task_signals.go b/pkg/sentry/kernel/task_signals.go index feaa38596..ebdb83061 100644 --- a/pkg/sentry/kernel/task_signals.go +++ b/pkg/sentry/kernel/task_signals.go @@ -259,7 +259,11 @@ func (t *Task) deliverSignalToHandler(info *arch.SignalInfo, act arch.SignalAct) // Set up the signal handler. If we have a saved signal mask, the signal // handler should run with the current mask, but sigreturn should restore // the saved one. - st := &arch.Stack{t.Arch(), mm, sp} + st := &arch.Stack{ + Arch: t.Arch(), + IO: mm, + Bottom: sp, + } mask := t.signalMask if t.haveSavedSignalMask { mask = t.savedSignalMask diff --git a/pkg/sentry/kernel/task_syscall.go b/pkg/sentry/kernel/task_syscall.go index 2dbf86547..0141459e7 100644 --- a/pkg/sentry/kernel/task_syscall.go +++ b/pkg/sentry/kernel/task_syscall.go @@ -22,6 +22,7 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/bits" + "gvisor.dev/gvisor/pkg/marshal" "gvisor.dev/gvisor/pkg/metric" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/memmap" @@ -287,7 +288,7 @@ func (t *Task) doVsyscall(addr usermem.Addr, sysno uintptr) taskRunState { // Grab the caller up front, to make sure there's a sensible stack. caller := t.Arch().Native(uintptr(0)) - if _, err := t.CopyIn(usermem.Addr(t.Arch().Stack()), caller); err != nil { + if _, err := caller.CopyIn(t, usermem.Addr(t.Arch().Stack())); err != nil { t.Debugf("vsyscall %d: error reading return address from stack: %v", sysno, err) t.forceSignal(linux.SIGSEGV, false /* unconditional */) t.SendSignal(SignalInfoPriv(linux.SIGSEGV)) @@ -323,7 +324,7 @@ func (t *Task) doVsyscall(addr usermem.Addr, sysno uintptr) taskRunState { type runVsyscallAfterPtraceEventSeccomp struct { addr usermem.Addr sysno uintptr - caller interface{} + caller marshal.Marshallable } func (r *runVsyscallAfterPtraceEventSeccomp) execute(t *Task) taskRunState { @@ -346,7 +347,7 @@ func (r *runVsyscallAfterPtraceEventSeccomp) execute(t *Task) taskRunState { return t.doVsyscallInvoke(sysno, t.Arch().SyscallArgs(), r.caller) } -func (t *Task) doVsyscallInvoke(sysno uintptr, args arch.SyscallArguments, caller interface{}) taskRunState { +func (t *Task) doVsyscallInvoke(sysno uintptr, args arch.SyscallArguments, caller marshal.Marshallable) taskRunState { rval, ctrl, err := t.executeSyscall(sysno, args) if ctrl != nil { t.Debugf("vsyscall %d, caller %x: syscall control: %v", sysno, t.Arch().Value(caller), ctrl) diff --git a/pkg/sentry/kernel/task_usermem.go b/pkg/sentry/kernel/task_usermem.go index 0cb86e390..ce134bf54 100644 --- a/pkg/sentry/kernel/task_usermem.go +++ b/pkg/sentry/kernel/task_usermem.go @@ -18,6 +18,7 @@ import ( "math" "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/marshal" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/usermem" ) @@ -43,17 +44,6 @@ func (t *Task) Deactivate() { } } -// CopyIn copies a fixed-size value or slice of fixed-size values in from the -// task's memory. The copy will fail with syscall.EFAULT if it traverses user -// memory that is unmapped or not readable by the user. -// -// This Task's AddressSpace must be active. -func (t *Task) CopyIn(addr usermem.Addr, dst interface{}) (int, error) { - return usermem.CopyObjectIn(t, t.MemoryManager(), addr, dst, usermem.IOOpts{ - AddressSpaceActive: true, - }) -} - // CopyInBytes is a fast version of CopyIn if the caller can serialize the // data without reflection and pass in a byte slice. // @@ -64,17 +54,6 @@ func (t *Task) CopyInBytes(addr usermem.Addr, dst []byte) (int, error) { }) } -// CopyOut copies a fixed-size value or slice of fixed-size values out to the -// task's memory. The copy will fail with syscall.EFAULT if it traverses user -// memory that is unmapped or not writeable by the user. -// -// This Task's AddressSpace must be active. -func (t *Task) CopyOut(addr usermem.Addr, src interface{}) (int, error) { - return usermem.CopyObjectOut(t, t.MemoryManager(), addr, src, usermem.IOOpts{ - AddressSpaceActive: true, - }) -} - // CopyOutBytes is a fast version of CopyOut if the caller can serialize the // data without reflection and pass in a byte slice. // @@ -114,7 +93,7 @@ func (t *Task) CopyInVector(addr usermem.Addr, maxElemSize, maxTotalSize int) ([ var v []string for { argAddr := t.Arch().Native(0) - if _, err := t.CopyIn(addr, argAddr); err != nil { + if _, err := argAddr.CopyIn(t, addr); err != nil { return v, err } if t.Arch().Value(argAddr) == 0 { @@ -302,29 +281,29 @@ func (t *Task) IovecsIOSequence(addr usermem.Addr, iovcnt int, opts usermem.IOOp }, nil } -// CopyContextWithOpts wraps a task to allow copying memory to and from the -// task memory with user specified usermem.IOOpts. -type CopyContextWithOpts struct { +// copyContext implements marshal.CopyContext. It wraps a task to allow copying +// memory to and from the task memory with custom usermem.IOOpts. +type copyContext struct { *Task opts usermem.IOOpts } -// AsCopyContextWithOpts wraps the task and returns it as CopyContextWithOpts. -func (t *Task) AsCopyContextWithOpts(opts usermem.IOOpts) *CopyContextWithOpts { - return &CopyContextWithOpts{t, opts} +// AsCopyContext wraps the task and returns it as CopyContext. +func (t *Task) AsCopyContext(opts usermem.IOOpts) marshal.CopyContext { + return ©Context{t, opts} } // CopyInString copies a string in from the task's memory. -func (t *CopyContextWithOpts) CopyInString(addr usermem.Addr, maxLen int) (string, error) { +func (t *copyContext) CopyInString(addr usermem.Addr, maxLen int) (string, error) { return usermem.CopyStringIn(t, t.MemoryManager(), addr, maxLen, t.opts) } // CopyInBytes copies task memory into dst from an IO context. -func (t *CopyContextWithOpts) CopyInBytes(addr usermem.Addr, dst []byte) (int, error) { +func (t *copyContext) CopyInBytes(addr usermem.Addr, dst []byte) (int, error) { return t.MemoryManager().CopyIn(t, addr, dst, t.opts) } // CopyOutBytes copies src into task memoryfrom an IO context. -func (t *CopyContextWithOpts) CopyOutBytes(addr usermem.Addr, src []byte) (int, error) { +func (t *copyContext) CopyOutBytes(addr usermem.Addr, src []byte) (int, error) { return t.MemoryManager().CopyOut(t, addr, src, t.opts) } diff --git a/pkg/sentry/kernel/threads.go b/pkg/sentry/kernel/threads.go index 872e1a82d..5ae5906e8 100644 --- a/pkg/sentry/kernel/threads.go +++ b/pkg/sentry/kernel/threads.go @@ -36,6 +36,8 @@ import ( const TasksLimit = (1 << 16) // ThreadID is a generic thread identifier. +// +// +marshal type ThreadID int32 // String returns a decimal representation of the ThreadID. diff --git a/pkg/sentry/loader/loader.go b/pkg/sentry/loader/loader.go index 15c88aa7c..c69b62db9 100644 --- a/pkg/sentry/loader/loader.go +++ b/pkg/sentry/loader/loader.go @@ -122,7 +122,7 @@ func allocStack(ctx context.Context, m *mm.MemoryManager, a arch.Context) (*arch if err != nil { return nil, err } - return &arch.Stack{a, m, ar.End}, nil + return &arch.Stack{Arch: a, IO: m, Bottom: ar.End}, nil } const ( @@ -247,20 +247,20 @@ func Load(ctx context.Context, args LoadArgs, extraAuxv []arch.AuxEntry, vdso *V } // Push the original filename to the stack, for AT_EXECFN. - execfn, err := stack.Push(args.Filename) - if err != nil { + if _, err := stack.PushNullTerminatedByteSlice([]byte(args.Filename)); err != nil { return 0, nil, "", syserr.NewDynamic(fmt.Sprintf("Failed to push exec filename: %v", err), syserr.FromError(err).ToLinux()) } + execfn := stack.Bottom // Push 16 random bytes on the stack which AT_RANDOM will point to. var b [16]byte if _, err := rand.Read(b[:]); err != nil { return 0, nil, "", syserr.NewDynamic(fmt.Sprintf("Failed to read random bytes: %v", err), syserr.FromError(err).ToLinux()) } - random, err := stack.Push(b) - if err != nil { + if _, err = stack.PushNullTerminatedByteSlice(b[:]); err != nil { return 0, nil, "", syserr.NewDynamic(fmt.Sprintf("Failed to push random bytes: %v", err), syserr.FromError(err).ToLinux()) } + random := stack.Bottom c := auth.CredentialsFromContext(ctx) diff --git a/pkg/sentry/mm/mm.go b/pkg/sentry/mm/mm.go index 3e85964e4..8c9f11cce 100644 --- a/pkg/sentry/mm/mm.go +++ b/pkg/sentry/mm/mm.go @@ -242,7 +242,7 @@ type MemoryManager struct { // +stateify savable type vma struct { // mappable is the virtual memory object mapped by this vma. If mappable is - // nil, the vma represents a private anonymous mapping. + // nil, the vma represents an anonymous mapping. mappable memmap.Mappable // off is the offset into mappable at which this vma begins. If mappable is diff --git a/pkg/sentry/mm/mm_test.go b/pkg/sentry/mm/mm_test.go index fdc308542..acac3d357 100644 --- a/pkg/sentry/mm/mm_test.go +++ b/pkg/sentry/mm/mm_test.go @@ -51,7 +51,8 @@ func TestUsageASUpdates(t *testing.T) { defer mm.DecUsers(ctx) addr, err := mm.MMap(ctx, memmap.MMapOpts{ - Length: 2 * usermem.PageSize, + Length: 2 * usermem.PageSize, + Private: true, }) if err != nil { t.Fatalf("MMap got err %v want nil", err) diff --git a/pkg/sentry/mm/special_mappable.go b/pkg/sentry/mm/special_mappable.go index f4c93baeb..2dbe5b751 100644 --- a/pkg/sentry/mm/special_mappable.go +++ b/pkg/sentry/mm/special_mappable.go @@ -136,9 +136,12 @@ func (m *SpecialMappable) Length() uint64 { // NewSharedAnonMappable returns a SpecialMappable that implements the // semantics of mmap(MAP_SHARED|MAP_ANONYMOUS) and mappings of /dev/zero. // -// TODO(jamieliu): The use of SpecialMappable is a lazy code reuse hack. Linux -// uses an ephemeral file created by mm/shmem.c:shmem_zero_setup(); we should -// do the same to get non-zero device and inode IDs. +// TODO(gvisor.dev/issue/1624): Linux uses an ephemeral file created by +// mm/shmem.c:shmem_zero_setup(), and VFS2 does something analogous. VFS1 uses +// a SpecialMappable instead, incorrectly getting device and inode IDs of zero +// and causing memory for shared anonymous mappings to be allocated up-front +// instead of on first touch; this is to avoid exacerbating the fs.MountSource +// leak (b/143656263). Delete this function along with VFS1. func NewSharedAnonMappable(length uint64, mfp pgalloc.MemoryFileProvider) (*SpecialMappable, error) { if length == 0 { return nil, syserror.EINVAL diff --git a/pkg/sentry/mm/syscalls.go b/pkg/sentry/mm/syscalls.go index 4c9a575e7..a2555ba1a 100644 --- a/pkg/sentry/mm/syscalls.go +++ b/pkg/sentry/mm/syscalls.go @@ -24,7 +24,6 @@ import ( "gvisor.dev/gvisor/pkg/sentry/kernel/futex" "gvisor.dev/gvisor/pkg/sentry/limits" "gvisor.dev/gvisor/pkg/sentry/memmap" - "gvisor.dev/gvisor/pkg/sentry/pgalloc" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/usermem" ) @@ -93,18 +92,6 @@ func (mm *MemoryManager) MMap(ctx context.Context, opts memmap.MMapOpts) (userme } } else { opts.Offset = 0 - if !opts.Private { - if opts.MappingIdentity != nil { - return 0, syserror.EINVAL - } - m, err := NewSharedAnonMappable(opts.Length, pgalloc.MemoryFileProviderFromContext(ctx)) - if err != nil { - return 0, err - } - defer m.DecRef(ctx) - opts.MappingIdentity = m - opts.Mappable = m - } } if opts.Addr.RoundDown() != opts.Addr { diff --git a/pkg/sentry/platform/kvm/BUILD b/pkg/sentry/platform/kvm/BUILD index 3970dd81d..323837fb1 100644 --- a/pkg/sentry/platform/kvm/BUILD +++ b/pkg/sentry/platform/kvm/BUILD @@ -9,12 +9,12 @@ go_library( "bluepill.go", "bluepill_allocator.go", "bluepill_amd64.go", - "bluepill_amd64.s", "bluepill_amd64_unsafe.go", "bluepill_arm64.go", "bluepill_arm64.s", "bluepill_arm64_unsafe.go", "bluepill_fault.go", + "bluepill_impl_amd64.s", "bluepill_unsafe.go", "context.go", "filters_amd64.go", @@ -81,3 +81,11 @@ go_test( "//pkg/usermem", ], ) + +genrule( + name = "bluepill_impl_amd64", + srcs = ["bluepill_amd64.s"], + outs = ["bluepill_impl_amd64.s"], + cmd = "(echo -e '// build +amd64\\n' && $(location //pkg/sentry/platform/ring0/gen_offsets) && cat $(SRCS)) > $@", + tools = ["//pkg/sentry/platform/ring0/gen_offsets"], +) diff --git a/pkg/sentry/platform/kvm/bluepill_amd64.s b/pkg/sentry/platform/kvm/bluepill_amd64.s index 2bc34a435..025ea93b5 100644 --- a/pkg/sentry/platform/kvm/bluepill_amd64.s +++ b/pkg/sentry/platform/kvm/bluepill_amd64.s @@ -19,11 +19,6 @@ // This is guaranteed to be zero. #define VCPU_CPU 0x0 -// CPU_SELF is the self reference in ring0's percpu. -// -// This is guaranteed to be zero. -#define CPU_SELF 0x0 - // Context offsets. // // Only limited use of the context is done in the assembly stub below, most is @@ -44,7 +39,7 @@ begin: LEAQ VCPU_CPU(AX), BX BYTE CLI; check_vcpu: - MOVQ CPU_SELF(GS), CX + MOVQ ENTRY_CPU_SELF(GS), CX CMPQ BX, CX JE right_vCPU wrong_vcpu: diff --git a/pkg/sentry/platform/kvm/kvm.go b/pkg/sentry/platform/kvm/kvm.go index ae813e24e..d46946402 100644 --- a/pkg/sentry/platform/kvm/kvm.go +++ b/pkg/sentry/platform/kvm/kvm.go @@ -156,15 +156,7 @@ func (*KVM) MaxUserAddress() usermem.Addr { func (k *KVM) NewAddressSpace(_ interface{}) (platform.AddressSpace, <-chan struct{}, error) { // Allocate page tables and install system mappings. pageTables := pagetables.New(newAllocator()) - applyPhysicalRegions(func(pr physicalRegion) bool { - // Map the kernel in the upper half. - pageTables.Map( - usermem.Addr(ring0.KernelStartAddress|pr.virtual), - pr.length, - pagetables.MapOpts{AccessType: usermem.AnyAccess}, - pr.physical) - return true // Keep iterating. - }) + k.machine.mapUpperHalf(pageTables) // Return the new address space. return &addressSpace{ diff --git a/pkg/sentry/platform/kvm/machine.go b/pkg/sentry/platform/kvm/machine.go index 372a4cbd7..75da253c5 100644 --- a/pkg/sentry/platform/kvm/machine.go +++ b/pkg/sentry/platform/kvm/machine.go @@ -155,7 +155,7 @@ func (m *machine) newVCPU() *vCPU { fd: int(fd), machine: m, } - c.CPU.Init(&m.kernel, c) + c.CPU.Init(&m.kernel, c.id, c) m.vCPUsByID[c.id] = c // Ensure the signal mask is correct. @@ -183,9 +183,6 @@ func newMachine(vm int) (*machine, error) { // Create the machine. m := &machine{fd: vm} m.available.L = &m.mu - m.kernel.Init(ring0.KernelOpts{ - PageTables: pagetables.New(newAllocator()), - }) // Pull the maximum vCPUs. maxVCPUs, _, errno := syscall.RawSyscall(syscall.SYS_IOCTL, uintptr(m.fd), _KVM_CHECK_EXTENSION, _KVM_CAP_MAX_VCPUS) @@ -197,6 +194,9 @@ func newMachine(vm int) (*machine, error) { log.Debugf("The maximum number of vCPUs is %d.", m.maxVCPUs) m.vCPUsByTID = make(map[uint64]*vCPU) m.vCPUsByID = make([]*vCPU, m.maxVCPUs) + m.kernel.Init(ring0.KernelOpts{ + PageTables: pagetables.New(newAllocator()), + }, m.maxVCPUs) // Pull the maximum slots. maxSlots, _, errno := syscall.RawSyscall(syscall.SYS_IOCTL, uintptr(m.fd), _KVM_CHECK_EXTENSION, _KVM_CAP_MAX_MEMSLOTS) @@ -219,15 +219,9 @@ func newMachine(vm int) (*machine, error) { pagetables.MapOpts{AccessType: usermem.AnyAccess}, pr.physical) - // And keep everything in the upper half. - m.kernel.PageTables.Map( - usermem.Addr(ring0.KernelStartAddress|pr.virtual), - pr.length, - pagetables.MapOpts{AccessType: usermem.AnyAccess}, - pr.physical) - return true // Keep iterating. }) + m.mapUpperHalf(m.kernel.PageTables) var physicalRegionsReadOnly []physicalRegion var physicalRegionsAvailable []physicalRegion @@ -365,6 +359,11 @@ func (m *machine) Destroy() { // Get gets an available vCPU. // // This will return with the OS thread locked. +// +// It is guaranteed that if any OS thread TID is in guest, m.vCPUs[TID] points +// to the vCPU in which the OS thread TID is running. So if Get() returns with +// the corrent context in guest, the vCPU of it must be the same as what +// Get() returns. func (m *machine) Get() *vCPU { m.mu.RLock() runtime.LockOSThread() diff --git a/pkg/sentry/platform/kvm/machine_amd64.go b/pkg/sentry/platform/kvm/machine_amd64.go index acc823ba6..6849ab113 100644 --- a/pkg/sentry/platform/kvm/machine_amd64.go +++ b/pkg/sentry/platform/kvm/machine_amd64.go @@ -144,6 +144,7 @@ func (c *vCPU) initArchState() error { // Set the entrypoint for the kernel. kernelUserRegs.RIP = uint64(reflect.ValueOf(ring0.Start).Pointer()) kernelUserRegs.RAX = uint64(reflect.ValueOf(&c.CPU).Pointer()) + kernelUserRegs.RSP = c.StackTop() kernelUserRegs.RFLAGS = ring0.KernelFlagsSet // Set the system registers. @@ -345,3 +346,43 @@ func rdonlyRegionsForSetMem() (phyRegions []physicalRegion) { func availableRegionsForSetMem() (phyRegions []physicalRegion) { return physicalRegions } + +var execRegions []region + +func init() { + applyVirtualRegions(func(vr virtualRegion) { + if excludeVirtualRegion(vr) || vr.filename == "[vsyscall]" { + return + } + + if vr.accessType.Execute { + execRegions = append(execRegions, vr.region) + } + }) +} + +func (m *machine) mapUpperHalf(pageTable *pagetables.PageTables) { + for _, r := range execRegions { + physical, length, ok := translateToPhysical(r.virtual) + if !ok || length < r.length { + panic("impossilbe translation") + } + pageTable.Map( + usermem.Addr(ring0.KernelStartAddress|r.virtual), + r.length, + pagetables.MapOpts{AccessType: usermem.Execute}, + physical) + } + for start, end := range m.kernel.EntryRegions() { + regionLen := end - start + physical, length, ok := translateToPhysical(start) + if !ok || length < regionLen { + panic("impossible translation") + } + pageTable.Map( + usermem.Addr(ring0.KernelStartAddress|start), + regionLen, + pagetables.MapOpts{AccessType: usermem.ReadWrite}, + physical) + } +} diff --git a/pkg/sentry/platform/kvm/machine_arm64.go b/pkg/sentry/platform/kvm/machine_arm64.go index 9db171af9..2df762991 100644 --- a/pkg/sentry/platform/kvm/machine_arm64.go +++ b/pkg/sentry/platform/kvm/machine_arm64.go @@ -19,6 +19,7 @@ package kvm import ( "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/platform" + "gvisor.dev/gvisor/pkg/sentry/platform/ring0" "gvisor.dev/gvisor/pkg/sentry/platform/ring0/pagetables" "gvisor.dev/gvisor/pkg/usermem" ) @@ -48,6 +49,18 @@ const ( poolPCIDs = 8 ) +func (m *machine) mapUpperHalf(pageTable *pagetables.PageTables) { + applyPhysicalRegions(func(pr physicalRegion) bool { + pageTable.Map( + usermem.Addr(ring0.KernelStartAddress|pr.virtual), + pr.length, + pagetables.MapOpts{AccessType: usermem.AnyAccess}, + pr.physical) + + return true // Keep iterating. + }) +} + // Get all read-only physicalRegions. func rdonlyRegionsForSetMem() (phyRegions []physicalRegion) { var rdonlyRegions []region diff --git a/pkg/sentry/platform/kvm/machine_arm64_unsafe.go b/pkg/sentry/platform/kvm/machine_arm64_unsafe.go index 905712076..537419657 100644 --- a/pkg/sentry/platform/kvm/machine_arm64_unsafe.go +++ b/pkg/sentry/platform/kvm/machine_arm64_unsafe.go @@ -79,7 +79,7 @@ func (c *vCPU) initArchState() error { } // tcr_el1 - data = _TCR_TXSZ_VA48 | _TCR_CACHE_FLAGS | _TCR_SHARED | _TCR_TG_FLAGS | _TCR_ASID16 | _TCR_IPS_40BITS + data = _TCR_TXSZ_VA48 | _TCR_CACHE_FLAGS | _TCR_SHARED | _TCR_TG_FLAGS | _TCR_ASID16 | _TCR_IPS_40BITS | _TCR_A1 reg.id = _KVM_ARM64_REGS_TCR_EL1 if err := c.setOneRegister(®); err != nil { return err @@ -103,7 +103,7 @@ func (c *vCPU) initArchState() error { c.SetTtbr0Kvm(uintptr(data)) // ttbr1_el1 - data = c.machine.kernel.PageTables.TTBR1_EL1(false, 0) + data = c.machine.kernel.PageTables.TTBR1_EL1(false, 1) reg.id = _KVM_ARM64_REGS_TTBR1_EL1 if err := c.setOneRegister(®); err != nil { diff --git a/pkg/sentry/platform/ptrace/BUILD b/pkg/sentry/platform/ptrace/BUILD index e04165fbf..fc43cc3c0 100644 --- a/pkg/sentry/platform/ptrace/BUILD +++ b/pkg/sentry/platform/ptrace/BUILD @@ -30,7 +30,6 @@ go_library( "//pkg/safecopy", "//pkg/seccomp", "//pkg/sentry/arch", - "//pkg/sentry/hostcpu", "//pkg/sentry/memmap", "//pkg/sentry/platform", "//pkg/sentry/platform/interrupt", diff --git a/pkg/sentry/platform/ptrace/filters.go b/pkg/sentry/platform/ptrace/filters.go index 1e07cfd0d..b0970e356 100644 --- a/pkg/sentry/platform/ptrace/filters.go +++ b/pkg/sentry/platform/ptrace/filters.go @@ -24,10 +24,9 @@ import ( // SyscallFilters returns syscalls made exclusively by the ptrace platform. func (*PTrace) SyscallFilters() seccomp.SyscallRules { return seccomp.SyscallRules{ - unix.SYS_GETCPU: {}, - unix.SYS_SCHED_SETAFFINITY: {}, - syscall.SYS_PTRACE: {}, - syscall.SYS_TGKILL: {}, - syscall.SYS_WAIT4: {}, + unix.SYS_GETCPU: {}, + syscall.SYS_PTRACE: {}, + syscall.SYS_TGKILL: {}, + syscall.SYS_WAIT4: {}, } } diff --git a/pkg/sentry/platform/ptrace/subprocess.go b/pkg/sentry/platform/ptrace/subprocess.go index e1d54d8a2..812ab80ef 100644 --- a/pkg/sentry/platform/ptrace/subprocess.go +++ b/pkg/sentry/platform/ptrace/subprocess.go @@ -518,11 +518,6 @@ func (s *subprocess) switchToApp(c *context, ac arch.Context) bool { } defer c.interrupt.Disable() - // Ensure that the CPU set is bound appropriately; this makes the - // emulation below several times faster, presumably by avoiding - // interprocessor wakeups and by simplifying the schedule. - t.bind() - // Set registers. if err := t.setRegs(regs); err != nil { panic(fmt.Sprintf("ptrace set regs (%+v) failed: %v", regs, err)) diff --git a/pkg/sentry/platform/ptrace/subprocess_amd64.go b/pkg/sentry/platform/ptrace/subprocess_amd64.go index 84b699f0d..020bbda79 100644 --- a/pkg/sentry/platform/ptrace/subprocess_amd64.go +++ b/pkg/sentry/platform/ptrace/subprocess_amd64.go @@ -201,7 +201,7 @@ func appendArchSeccompRules(rules []seccomp.RuleSet, defaultAction linux.BPFActi seccomp.RuleSet{ Rules: seccomp.SyscallRules{ syscall.SYS_ARCH_PRCTL: []seccomp.Rule{ - {seccomp.AllowValue(linux.ARCH_SET_CPUID), seccomp.AllowValue(0)}, + {seccomp.EqualTo(linux.ARCH_SET_CPUID), seccomp.EqualTo(0)}, }, }, Action: linux.SECCOMP_RET_ALLOW, diff --git a/pkg/sentry/platform/ptrace/subprocess_linux.go b/pkg/sentry/platform/ptrace/subprocess_linux.go index 2ce528601..8548853da 100644 --- a/pkg/sentry/platform/ptrace/subprocess_linux.go +++ b/pkg/sentry/platform/ptrace/subprocess_linux.go @@ -80,9 +80,9 @@ func attachedThread(flags uintptr, defaultAction linux.BPFAction) (*thread, erro Rules: seccomp.SyscallRules{ syscall.SYS_CLONE: []seccomp.Rule{ // Allow creation of new subprocesses (used by the master). - {seccomp.AllowValue(syscall.CLONE_FILES | syscall.SIGKILL)}, + {seccomp.EqualTo(syscall.CLONE_FILES | syscall.SIGKILL)}, // Allow creation of new threads within a single address space (used by addresss spaces). - {seccomp.AllowValue( + {seccomp.EqualTo( syscall.CLONE_FILES | syscall.CLONE_FS | syscall.CLONE_SIGHAND | @@ -97,14 +97,14 @@ func attachedThread(flags uintptr, defaultAction linux.BPFAction) (*thread, erro // For the stub prctl dance (all). syscall.SYS_PRCTL: []seccomp.Rule{ - {seccomp.AllowValue(syscall.PR_SET_PDEATHSIG), seccomp.AllowValue(syscall.SIGKILL)}, + {seccomp.EqualTo(syscall.PR_SET_PDEATHSIG), seccomp.EqualTo(syscall.SIGKILL)}, }, syscall.SYS_GETPPID: {}, // For the stub to stop itself (all). syscall.SYS_GETPID: {}, syscall.SYS_KILL: []seccomp.Rule{ - {seccomp.AllowAny{}, seccomp.AllowValue(syscall.SIGSTOP)}, + {seccomp.MatchAny{}, seccomp.EqualTo(syscall.SIGSTOP)}, }, // Injected to support the address space operations. @@ -115,7 +115,7 @@ func attachedThread(flags uintptr, defaultAction linux.BPFAction) (*thread, erro }) } rules = appendArchSeccompRules(rules, defaultAction) - instrs, err := seccomp.BuildProgram(rules, defaultAction) + instrs, err := seccomp.BuildProgram(rules, defaultAction, defaultAction) if err != nil { return nil, err } diff --git a/pkg/sentry/platform/ptrace/subprocess_linux_unsafe.go b/pkg/sentry/platform/ptrace/subprocess_linux_unsafe.go index 245b20722..533e45497 100644 --- a/pkg/sentry/platform/ptrace/subprocess_linux_unsafe.go +++ b/pkg/sentry/platform/ptrace/subprocess_linux_unsafe.go @@ -18,29 +18,12 @@ package ptrace import ( - "sync/atomic" "syscall" "unsafe" - "golang.org/x/sys/unix" "gvisor.dev/gvisor/pkg/abi/linux" - "gvisor.dev/gvisor/pkg/sentry/hostcpu" - "gvisor.dev/gvisor/pkg/sync" ) -// maskPool contains reusable CPU masks for setting affinity. Unfortunately, -// runtime.NumCPU doesn't actually record the number of CPUs on the system, it -// just records the number of CPUs available in the scheduler affinity set at -// startup. This may a) change over time and b) gives a number far lower than -// the maximum indexable CPU. To prevent lots of allocation in the hot path, we -// use a pool to store large masks that we can reuse during bind. -var maskPool = sync.Pool{ - New: func() interface{} { - const maxCPUs = 1024 // Not a hard limit; see below. - return make([]uintptr, maxCPUs/64) - }, -} - // unmaskAllSignals unmasks all signals on the current thread. // //go:nosplit @@ -49,47 +32,3 @@ func unmaskAllSignals() syscall.Errno { _, _, errno := syscall.RawSyscall6(syscall.SYS_RT_SIGPROCMASK, linux.SIG_SETMASK, uintptr(unsafe.Pointer(&set)), 0, linux.SignalSetSize, 0, 0) return errno } - -// setCPU sets the CPU affinity. -func (t *thread) setCPU(cpu uint32) error { - mask := maskPool.Get().([]uintptr) - n := int(cpu / 64) - v := uintptr(1 << uintptr(cpu%64)) - if n >= len(mask) { - // See maskPool note above. We've actually exceeded the number - // of available cores. Grow the mask and return it. - mask = make([]uintptr, n+1) - } - mask[n] |= v - if _, _, errno := syscall.RawSyscall( - unix.SYS_SCHED_SETAFFINITY, - uintptr(t.tid), - uintptr(len(mask)*8), - uintptr(unsafe.Pointer(&mask[0]))); errno != 0 { - return errno - } - mask[n] &^= v - maskPool.Put(mask) - return nil -} - -// bind attempts to ensure that the thread is on the same CPU as the current -// thread. This provides no guarantees as it is fundamentally a racy operation: -// CPU sets may change and we may be rescheduled in the middle of this -// operation. As a result, no failures are reported. -// -// Precondition: the current runtime thread should be locked. -func (t *thread) bind() { - currentCPU := hostcpu.GetCPU() - - if oldCPU := atomic.SwapUint32(&t.cpu, currentCPU); oldCPU != currentCPU { - // Set the affinity on the thread and save the CPU for next - // round; we don't expect CPUs to bounce around too frequently. - // - // (It's worth noting that we could move CPUs between this point - // and when the tracee finishes executing. But that would be - // roughly the status quo anyways -- we're just maximizing our - // chances of colocation, not guaranteeing it.) - t.setCPU(currentCPU) - } -} diff --git a/pkg/sentry/platform/ring0/defs_amd64.go b/pkg/sentry/platform/ring0/defs_amd64.go index 9c6c2cf5c..f617519fa 100644 --- a/pkg/sentry/platform/ring0/defs_amd64.go +++ b/pkg/sentry/platform/ring0/defs_amd64.go @@ -76,15 +76,42 @@ type KernelOpts struct { type KernelArchState struct { KernelOpts + // cpuEntries is array of kernelEntry for all cpus + cpuEntries []kernelEntry + // globalIDT is our set of interrupt gates. - globalIDT idt64 + globalIDT *idt64 } -// CPUArchState contains CPU-specific arch state. -type CPUArchState struct { +// kernelEntry contains minimal CPU-specific arch state +// that can be mapped at the upper of the address space. +// Malicious APP might steal info from it via CPU bugs. +type kernelEntry struct { // stack is the stack used for interrupts on this CPU. stack [256]byte + // scratch space for temporary usage. + scratch0 uint64 + scratch1 uint64 + + // stackTop is the top of the stack. + stackTop uint64 + + // cpuSelf is back reference to CPU. + cpuSelf *CPU + + // kernelCR3 is the cr3 used for sentry kernel. + kernelCR3 uintptr + + // gdt is the CPU's descriptor table. + gdt descriptorTable + + // tss is the CPU's task state. + tss TaskState64 +} + +// CPUArchState contains CPU-specific arch state. +type CPUArchState struct { // errorCode is the error code from the last exception. errorCode uintptr @@ -97,11 +124,7 @@ type CPUArchState struct { // exception. errorType uintptr - // gdt is the CPU's descriptor table. - gdt descriptorTable - - // tss is the CPU's task state. - tss TaskState64 + *kernelEntry } // ErrorCode returns the last error code. diff --git a/pkg/sentry/platform/ring0/defs_arm64.go b/pkg/sentry/platform/ring0/defs_arm64.go index 0e2ab716c..508236e46 100644 --- a/pkg/sentry/platform/ring0/defs_arm64.go +++ b/pkg/sentry/platform/ring0/defs_arm64.go @@ -77,6 +77,9 @@ type CPUArchState struct { // lazyVFP is the value of cpacr_el1. lazyVFP uintptr + + // appASID is the asid value of guest application. + appASID uintptr } // ErrorCode returns the last error code. diff --git a/pkg/sentry/platform/ring0/entry_amd64.go b/pkg/sentry/platform/ring0/entry_amd64.go index 7fa43c2f5..d87b1fd00 100644 --- a/pkg/sentry/platform/ring0/entry_amd64.go +++ b/pkg/sentry/platform/ring0/entry_amd64.go @@ -36,12 +36,15 @@ func sysenter() // This must be called prior to sysret/iret. func swapgs() +// jumpToKernel jumps to the kernel version of the current RIP. +func jumpToKernel() + // sysret returns to userspace from a system call. // // The return code is the vector that interrupted execution. // // See stubs.go for a note regarding the frame size of this function. -func sysret(*CPU, *arch.Registers) Vector +func sysret(cpu *CPU, regs *arch.Registers, userCR3 uintptr) Vector // "iret is the cadillac of CPL switching." // @@ -50,7 +53,7 @@ func sysret(*CPU, *arch.Registers) Vector // iret is nearly identical to sysret, except an iret is used to fully restore // all user state. This must be called in cases where all registers need to be // restored. -func iret(*CPU, *arch.Registers) Vector +func iret(cpu *CPU, regs *arch.Registers, userCR3 uintptr) Vector // exception is the generic exception entry. // diff --git a/pkg/sentry/platform/ring0/entry_amd64.s b/pkg/sentry/platform/ring0/entry_amd64.s index 02df38331..82689a194 100644 --- a/pkg/sentry/platform/ring0/entry_amd64.s +++ b/pkg/sentry/platform/ring0/entry_amd64.s @@ -63,6 +63,15 @@ MOVQ offset+PTRACE_RSI(reg), SI; \ MOVQ offset+PTRACE_RDI(reg), DI; +// WRITE_CR3() writes the given CR3 value. +// +// The code corresponds to: +// +// mov %rax, %cr3 +// +#define WRITE_CR3() \ + BYTE $0x0f; BYTE $0x22; BYTE $0xd8; + // SWAP_GS swaps the kernel GS (CPU). #define SWAP_GS() \ BYTE $0x0F; BYTE $0x01; BYTE $0xf8; @@ -75,15 +84,9 @@ #define SYSRET64() \ BYTE $0x48; BYTE $0x0f; BYTE $0x07; -// LOAD_KERNEL_ADDRESS loads a kernel address. -#define LOAD_KERNEL_ADDRESS(from, to) \ - MOVQ from, to; \ - ORQ ·KernelStartAddress(SB), to; - // LOAD_KERNEL_STACK loads the kernel stack. -#define LOAD_KERNEL_STACK(from) \ - LOAD_KERNEL_ADDRESS(CPU_SELF(from), SP); \ - LEAQ CPU_STACK_TOP(SP), SP; +#define LOAD_KERNEL_STACK(entry) \ + MOVQ ENTRY_STACK_TOP(entry), SP; // See kernel.go. TEXT ·Halt(SB),NOSPLIT,$0 @@ -95,58 +98,93 @@ TEXT ·swapgs(SB),NOSPLIT,$0 SWAP_GS() RET +// jumpToKernel changes execution to the kernel address space. +// +// This works by changing the return value to the kernel version. +TEXT ·jumpToKernel(SB),NOSPLIT,$0 + MOVQ 0(SP), AX + ORQ ·KernelStartAddress(SB), AX // Future return value. + MOVQ AX, 0(SP) + RET + // See entry_amd64.go. TEXT ·sysret(SB),NOSPLIT,$0-24 - // Save original state. - LOAD_KERNEL_ADDRESS(cpu+0(FP), BX) - LOAD_KERNEL_ADDRESS(regs+8(FP), AX) + CALL ·jumpToKernel(SB) + // Save original state and stack. sysenter() or exception() + // from APP(gr3) will switch to this stack, set the return + // value (vector: 32(SP)) and then do RET, which will also + // automatically return to the lower half. + MOVQ cpu+0(FP), BX + MOVQ regs+8(FP), AX + MOVQ userCR3+16(FP), CX MOVQ SP, CPU_REGISTERS+PTRACE_RSP(BX) MOVQ BP, CPU_REGISTERS+PTRACE_RBP(BX) MOVQ AX, CPU_REGISTERS+PTRACE_RAX(BX) + // save SP AX userCR3 on the kernel stack. + MOVQ CPU_ENTRY(BX), BX + LOAD_KERNEL_STACK(BX) + PUSHQ PTRACE_RSP(AX) + PUSHQ PTRACE_RAX(AX) + PUSHQ CX + // Restore user register state. REGISTERS_LOAD(AX, 0) MOVQ PTRACE_RIP(AX), CX // Needed for SYSRET. MOVQ PTRACE_FLAGS(AX), R11 // Needed for SYSRET. - MOVQ PTRACE_RSP(AX), SP // Restore the stack directly. - MOVQ PTRACE_RAX(AX), AX // Restore AX (scratch). + + // restore userCR3, AX, SP. + POPQ AX // Get userCR3. + WRITE_CR3() // Switch to userCR3. + POPQ AX // Restore AX. + POPQ SP // Restore SP. SYSRET64() // See entry_amd64.go. TEXT ·iret(SB),NOSPLIT,$0-24 - // Save original state. - LOAD_KERNEL_ADDRESS(cpu+0(FP), BX) - LOAD_KERNEL_ADDRESS(regs+8(FP), AX) + CALL ·jumpToKernel(SB) + // Save original state and stack. sysenter() or exception() + // from APP(gr3) will switch to this stack, set the return + // value (vector: 32(SP)) and then do RET, which will also + // automatically return to the lower half. + MOVQ cpu+0(FP), BX + MOVQ regs+8(FP), AX + MOVQ userCR3+16(FP), CX MOVQ SP, CPU_REGISTERS+PTRACE_RSP(BX) MOVQ BP, CPU_REGISTERS+PTRACE_RBP(BX) MOVQ AX, CPU_REGISTERS+PTRACE_RAX(BX) // Build an IRET frame & restore state. + MOVQ CPU_ENTRY(BX), BX LOAD_KERNEL_STACK(BX) - MOVQ PTRACE_SS(AX), BX; PUSHQ BX - MOVQ PTRACE_RSP(AX), CX; PUSHQ CX - MOVQ PTRACE_FLAGS(AX), DX; PUSHQ DX - MOVQ PTRACE_CS(AX), DI; PUSHQ DI - MOVQ PTRACE_RIP(AX), SI; PUSHQ SI - REGISTERS_LOAD(AX, 0) // Restore most registers. - MOVQ PTRACE_RAX(AX), AX // Restore AX (scratch). + PUSHQ PTRACE_SS(AX) + PUSHQ PTRACE_RSP(AX) + PUSHQ PTRACE_FLAGS(AX) + PUSHQ PTRACE_CS(AX) + PUSHQ PTRACE_RIP(AX) + PUSHQ PTRACE_RAX(AX) // Save AX on kernel stack. + PUSHQ CX // Save userCR3 on kernel stack. + REGISTERS_LOAD(AX, 0) // Restore most registers. + POPQ AX // Get userCR3. + WRITE_CR3() // Switch to userCR3. + POPQ AX // Restore AX. IRET() // See entry_amd64.go. TEXT ·resume(SB),NOSPLIT,$0 // See iret, above. - MOVQ CPU_REGISTERS+PTRACE_SS(GS), BX; PUSHQ BX - MOVQ CPU_REGISTERS+PTRACE_RSP(GS), CX; PUSHQ CX - MOVQ CPU_REGISTERS+PTRACE_FLAGS(GS), DX; PUSHQ DX - MOVQ CPU_REGISTERS+PTRACE_CS(GS), DI; PUSHQ DI - MOVQ CPU_REGISTERS+PTRACE_RIP(GS), SI; PUSHQ SI - REGISTERS_LOAD(GS, CPU_REGISTERS) - MOVQ CPU_REGISTERS+PTRACE_RAX(GS), AX + MOVQ ENTRY_CPU_SELF(GS), AX // Load vCPU. + PUSHQ CPU_REGISTERS+PTRACE_SS(AX) + PUSHQ CPU_REGISTERS+PTRACE_RSP(AX) + PUSHQ CPU_REGISTERS+PTRACE_FLAGS(AX) + PUSHQ CPU_REGISTERS+PTRACE_CS(AX) + PUSHQ CPU_REGISTERS+PTRACE_RIP(AX) + REGISTERS_LOAD(AX, CPU_REGISTERS) + MOVQ CPU_REGISTERS+PTRACE_RAX(AX), AX IRET() // See entry_amd64.go. TEXT ·Start(SB),NOSPLIT,$0 - LOAD_KERNEL_STACK(AX) // Set the stack. PUSHQ $0x0 // Previous frame pointer. MOVQ SP, BP // Set frame pointer. PUSHQ AX // First argument (CPU). @@ -164,44 +202,54 @@ TEXT ·sysenter(SB),NOSPLIT,$0 user: SWAP_GS() - XCHGQ CPU_REGISTERS+PTRACE_RSP(GS), SP // Swap stacks. - XCHGQ CPU_REGISTERS+PTRACE_RAX(GS), AX // Swap for AX (regs). + MOVQ AX, ENTRY_SCRATCH0(GS) // Save user AX on scratch. + MOVQ ENTRY_KERNEL_CR3(GS), AX // Get kernel cr3 on AX. + WRITE_CR3() // Switch to kernel cr3. + + MOVQ ENTRY_CPU_SELF(GS), AX // Load vCPU. + MOVQ CPU_REGISTERS+PTRACE_RAX(AX), AX // Get user regs. REGISTERS_SAVE(AX, 0) // Save all except IP, FLAGS, SP, AX. - MOVQ CPU_REGISTERS+PTRACE_RAX(GS), BX // Load saved AX value. - MOVQ BX, PTRACE_RAX(AX) // Save everything else. - MOVQ BX, PTRACE_ORIGRAX(AX) MOVQ CX, PTRACE_RIP(AX) MOVQ R11, PTRACE_FLAGS(AX) - MOVQ CPU_REGISTERS+PTRACE_RSP(GS), BX; MOVQ BX, PTRACE_RSP(AX) - MOVQ $0, CPU_ERROR_CODE(GS) // Clear error code. - MOVQ $1, CPU_ERROR_TYPE(GS) // Set error type to user. + MOVQ SP, PTRACE_RSP(AX) + MOVQ ENTRY_SCRATCH0(GS), CX // Load saved user AX value. + MOVQ CX, PTRACE_RAX(AX) // Save everything else. + MOVQ CX, PTRACE_ORIGRAX(AX) + + MOVQ ENTRY_CPU_SELF(GS), AX // Load vCPU. + MOVQ CPU_REGISTERS+PTRACE_RSP(AX), SP // Get stacks. + MOVQ $0, CPU_ERROR_CODE(AX) // Clear error code. + MOVQ $1, CPU_ERROR_TYPE(AX) // Set error type to user. // Return to the kernel, where the frame is: // - // vector (sp+24) + // vector (sp+32) + // userCR3 (sp+24) // regs (sp+16) // cpu (sp+8) // vcpu.Switch (sp+0) // - MOVQ CPU_REGISTERS+PTRACE_RBP(GS), BP // Original base pointer. - MOVQ $Syscall, 24(SP) // Output vector. + MOVQ CPU_REGISTERS+PTRACE_RBP(AX), BP // Original base pointer. + MOVQ $Syscall, 32(SP) // Output vector. RET kernel: // We can't restore the original stack, but we can access the registers // in the CPU state directly. No need for temporary juggling. - MOVQ AX, CPU_REGISTERS+PTRACE_ORIGRAX(GS) - MOVQ AX, CPU_REGISTERS+PTRACE_RAX(GS) - REGISTERS_SAVE(GS, CPU_REGISTERS) - MOVQ CX, CPU_REGISTERS+PTRACE_RIP(GS) - MOVQ R11, CPU_REGISTERS+PTRACE_FLAGS(GS) - MOVQ SP, CPU_REGISTERS+PTRACE_RSP(GS) - MOVQ $0, CPU_ERROR_CODE(GS) // Clear error code. - MOVQ $0, CPU_ERROR_TYPE(GS) // Set error type to kernel. + MOVQ AX, ENTRY_SCRATCH0(GS) + MOVQ ENTRY_CPU_SELF(GS), AX // Load vCPU. + REGISTERS_SAVE(AX, CPU_REGISTERS) + MOVQ CX, CPU_REGISTERS+PTRACE_RIP(AX) + MOVQ R11, CPU_REGISTERS+PTRACE_FLAGS(AX) + MOVQ SP, CPU_REGISTERS+PTRACE_RSP(AX) + MOVQ ENTRY_SCRATCH0(GS), BX + MOVQ BX, CPU_REGISTERS+PTRACE_ORIGRAX(AX) + MOVQ BX, CPU_REGISTERS+PTRACE_RAX(AX) + MOVQ $0, CPU_ERROR_CODE(AX) // Clear error code. + MOVQ $0, CPU_ERROR_TYPE(AX) // Set error type to kernel. // Call the syscall trampoline. LOAD_KERNEL_STACK(GS) - MOVQ CPU_SELF(GS), AX // Load vCPU. PUSHQ AX // First argument (vCPU). CALL ·kernelSyscall(SB) // Call the trampoline. POPQ AX // Pop vCPU. @@ -237,9 +285,14 @@ user: SWAP_GS() ADDQ $-8, SP // Adjust for flags. MOVQ $_KERNEL_FLAGS, 0(SP); BYTE $0x9d; // Reset flags (POPFQ). - XCHGQ CPU_REGISTERS+PTRACE_RAX(GS), AX // Swap for user regs. + PUSHQ AX // Save user AX on stack. + MOVQ ENTRY_KERNEL_CR3(GS), AX // Get kernel cr3 on AX. + WRITE_CR3() // Switch to kernel cr3. + + MOVQ ENTRY_CPU_SELF(GS), AX // Load vCPU. + MOVQ CPU_REGISTERS+PTRACE_RAX(AX), AX // Get user regs. REGISTERS_SAVE(AX, 0) // Save all except IP, FLAGS, SP, AX. - MOVQ CPU_REGISTERS+PTRACE_RAX(GS), BX // Restore original AX. + POPQ BX // Restore original AX. MOVQ BX, PTRACE_RAX(AX) // Save it. MOVQ BX, PTRACE_ORIGRAX(AX) MOVQ 16(SP), BX; MOVQ BX, PTRACE_RIP(AX) @@ -249,34 +302,36 @@ user: MOVQ 48(SP), SI; MOVQ SI, PTRACE_SS(AX) // Copy out and return. + MOVQ ENTRY_CPU_SELF(GS), AX // Load vCPU. MOVQ 0(SP), BX // Load vector. MOVQ 8(SP), CX // Load error code. - MOVQ CPU_REGISTERS+PTRACE_RSP(GS), SP // Original stack (kernel version). - MOVQ CPU_REGISTERS+PTRACE_RBP(GS), BP // Original base pointer. - MOVQ CX, CPU_ERROR_CODE(GS) // Set error code. - MOVQ $1, CPU_ERROR_TYPE(GS) // Set error type to user. - MOVQ BX, 24(SP) // Output vector. + MOVQ CPU_REGISTERS+PTRACE_RSP(AX), SP // Original stack (kernel version). + MOVQ CPU_REGISTERS+PTRACE_RBP(AX), BP // Original base pointer. + MOVQ CX, CPU_ERROR_CODE(AX) // Set error code. + MOVQ $1, CPU_ERROR_TYPE(AX) // Set error type to user. + MOVQ BX, 32(SP) // Output vector. RET kernel: // As per above, we can save directly. - MOVQ AX, CPU_REGISTERS+PTRACE_RAX(GS) - MOVQ AX, CPU_REGISTERS+PTRACE_ORIGRAX(GS) - REGISTERS_SAVE(GS, CPU_REGISTERS) - MOVQ 16(SP), AX; MOVQ AX, CPU_REGISTERS+PTRACE_RIP(GS) - MOVQ 32(SP), BX; MOVQ BX, CPU_REGISTERS+PTRACE_FLAGS(GS) - MOVQ 40(SP), CX; MOVQ CX, CPU_REGISTERS+PTRACE_RSP(GS) + PUSHQ AX + MOVQ ENTRY_CPU_SELF(GS), AX // Load vCPU. + REGISTERS_SAVE(AX, CPU_REGISTERS) + POPQ BX + MOVQ BX, CPU_REGISTERS+PTRACE_RAX(AX) + MOVQ BX, CPU_REGISTERS+PTRACE_ORIGRAX(AX) + MOVQ 16(SP), BX; MOVQ BX, CPU_REGISTERS+PTRACE_RIP(AX) + MOVQ 32(SP), BX; MOVQ BX, CPU_REGISTERS+PTRACE_FLAGS(AX) + MOVQ 40(SP), BX; MOVQ BX, CPU_REGISTERS+PTRACE_RSP(AX) // Set the error code and adjust the stack. - MOVQ 8(SP), AX // Load the error code. - MOVQ AX, CPU_ERROR_CODE(GS) // Copy out to the CPU. - MOVQ $0, CPU_ERROR_TYPE(GS) // Set error type to kernel. + MOVQ 8(SP), BX // Load the error code. + MOVQ BX, CPU_ERROR_CODE(AX) // Copy out to the CPU. + MOVQ $0, CPU_ERROR_TYPE(AX) // Set error type to kernel. MOVQ 0(SP), BX // BX contains the vector. - ADDQ $48, SP // Drop the exception frame. // Call the exception trampoline. LOAD_KERNEL_STACK(GS) - MOVQ CPU_SELF(GS), AX // Load vCPU. PUSHQ BX // Second argument (vector). PUSHQ AX // First argument (vCPU). CALL ·kernelException(SB) // Call the trampoline. diff --git a/pkg/sentry/platform/ring0/entry_arm64.s b/pkg/sentry/platform/ring0/entry_arm64.s index 9d29b7168..5f63cbd45 100644 --- a/pkg/sentry/platform/ring0/entry_arm64.s +++ b/pkg/sentry/platform/ring0/entry_arm64.s @@ -27,7 +27,9 @@ // ERET returns using the ELR and SPSR for the current exception level. #define ERET() \ - WORD $0xd69f03e0 + WORD $0xd69f03e0; \ + DSB $7; \ + ISB $15; // RSV_REG is a register that holds el1 information temporarily. #define RSV_REG R18_PLATFORM @@ -300,17 +302,23 @@ // SWITCH_TO_APP_PAGETABLE sets a new pagetable for a container application. #define SWITCH_TO_APP_PAGETABLE(from) \ - MOVD CPU_TTBR0_APP(from), RSV_REG; \ - WORD $0xd5182012; \ // MSR R18, TTBR0_EL1 + MRS TTBR1_EL1, R0; \ + MOVD CPU_APP_ASID(from), R1; \ + BFI $48, R1, $16, R0; \ + MSR R0, TTBR1_EL1; \ // set the ASID in TTBR1_EL1 (since TCR.A1 is set) ISB $15; \ - DSB $15; + MOVD CPU_TTBR0_APP(from), RSV_REG; \ + MSR RSV_REG, TTBR0_EL1; // SWITCH_TO_KVM_PAGETABLE sets the kvm pagetable. #define SWITCH_TO_KVM_PAGETABLE(from) \ - MOVD CPU_TTBR0_KVM(from), RSV_REG; \ - WORD $0xd5182012; \ // MSR R18, TTBR0_EL1 + MRS TTBR1_EL1, R0; \ + MOVD $1, R1; \ + BFI $48, R1, $16, R0; \ + MSR R0, TTBR1_EL1; \ ISB $15; \ - DSB $15; + MOVD CPU_TTBR0_KVM(from), RSV_REG; \ + MSR RSV_REG, TTBR0_EL1; #define VFP_ENABLE \ MOVD $FPEN_ENABLE, R0; \ @@ -326,23 +334,20 @@ #define KERNEL_ENTRY_FROM_EL0 \ SUB $16, RSP, RSP; \ // step1, save r18, r9 into kernel temporary stack. STP (RSV_REG, RSV_REG_APP), 16*0(RSP); \ - WORD $0xd538d092; \ //MRS TPIDR_EL1, R18, step2, switch user pagetable. - SWITCH_TO_KVM_PAGETABLE(RSV_REG); \ - WORD $0xd538d092; \ //MRS TPIDR_EL1, R18 - MOVD CPU_APP_ADDR(RSV_REG), RSV_REG_APP; \ // step3, load app context pointer. - REGISTERS_SAVE(RSV_REG_APP, 0); \ // step4, save app context. + WORD $0xd538d092; \ // MRS TPIDR_EL1, R18 + MOVD CPU_APP_ADDR(RSV_REG), RSV_REG_APP; \ // step2, load app context pointer. + REGISTERS_SAVE(RSV_REG_APP, 0); \ // step3, save app context. MOVD RSV_REG_APP, R20; \ LDP 16*0(RSP), (RSV_REG, RSV_REG_APP); \ ADD $16, RSP, RSP; \ MOVD RSV_REG, PTRACE_R18(R20); \ MOVD RSV_REG_APP, PTRACE_R9(R20); \ - MOVD R20, RSV_REG_APP; \ WORD $0xd5384003; \ // MRS SPSR_EL1, R3 - MOVD R3, PTRACE_PSTATE(RSV_REG_APP); \ + MOVD R3, PTRACE_PSTATE(R20); \ MRS ELR_EL1, R3; \ - MOVD R3, PTRACE_PC(RSV_REG_APP); \ + MOVD R3, PTRACE_PC(R20); \ WORD $0xd5384103; \ // MRS SP_EL0, R3 - MOVD R3, PTRACE_SP(RSV_REG_APP); + MOVD R3, PTRACE_SP(R20); // KERNEL_ENTRY_FROM_EL1 is the entry code of the vcpu from el1 to el1. #define KERNEL_ENTRY_FROM_EL1 \ @@ -357,6 +362,13 @@ MOVD R4, CPU_REGISTERS+PTRACE_SP(RSV_REG); \ LOAD_KERNEL_STACK(RSV_REG); // Load the temporary stack. +// storeAppASID writes the application's asid value. +TEXT ·storeAppASID(SB),NOSPLIT,$0-8 + MOVD asid+0(FP), R1 + MRS TPIDR_EL1, RSV_REG + MOVD R1, CPU_APP_ASID(RSV_REG) + RET + // Halt halts execution. TEXT ·Halt(SB),NOSPLIT,$0 // Clear bluepill. @@ -414,7 +426,7 @@ TEXT ·Current(SB),NOSPLIT,$0-8 MOVD R8, ret+0(FP) RET -#define STACK_FRAME_SIZE 16 +#define STACK_FRAME_SIZE 32 // kernelExitToEl0 is the entrypoint for application in guest_el0. // Prepare the vcpu environment for container application. @@ -458,15 +470,16 @@ TEXT ·kernelExitToEl0(SB),NOSPLIT,$0 SUB $STACK_FRAME_SIZE, RSP, RSP STP (RSV_REG, RSV_REG_APP), 16*0(RSP) + STP (R0, R1), 16*1(RSP) WORD $0xd538d092 //MRS TPIDR_EL1, R18 SWITCH_TO_APP_PAGETABLE(RSV_REG) + LDP 16*1(RSP), (R0, R1) LDP 16*0(RSP), (RSV_REG, RSV_REG_APP) ADD $STACK_FRAME_SIZE, RSP, RSP - ISB $15 ERET() // kernelExitToEl1 is the entrypoint for sentry in guest_el1. @@ -482,6 +495,9 @@ TEXT ·kernelExitToEl1(SB),NOSPLIT,$0 MOVD CPU_REGISTERS+PTRACE_SP(RSV_REG), R1 MOVD R1, RSP + SWITCH_TO_KVM_PAGETABLE(RSV_REG) + MRS TPIDR_EL1, RSV_REG + REGISTERS_LOAD(RSV_REG, CPU_REGISTERS) MOVD CPU_REGISTERS+PTRACE_R9(RSV_REG), RSV_REG_APP diff --git a/pkg/sentry/platform/ring0/gen_offsets/BUILD b/pkg/sentry/platform/ring0/gen_offsets/BUILD index 549f3d228..9742308d8 100644 --- a/pkg/sentry/platform/ring0/gen_offsets/BUILD +++ b/pkg/sentry/platform/ring0/gen_offsets/BUILD @@ -24,7 +24,10 @@ go_binary( "defs_impl_arm64.go", "main.go", ], - visibility = ["//pkg/sentry/platform/ring0:__pkg__"], + visibility = [ + "//pkg/sentry/platform/kvm:__pkg__", + "//pkg/sentry/platform/ring0:__pkg__", + ], deps = [ "//pkg/cpuid", "//pkg/sentry/arch", diff --git a/pkg/sentry/platform/ring0/kernel.go b/pkg/sentry/platform/ring0/kernel.go index 021693791..264be23d3 100644 --- a/pkg/sentry/platform/ring0/kernel.go +++ b/pkg/sentry/platform/ring0/kernel.go @@ -19,8 +19,8 @@ package ring0 // N.B. that constraints on KernelOpts must be satisfied. // //go:nosplit -func (k *Kernel) Init(opts KernelOpts) { - k.init(opts) +func (k *Kernel) Init(opts KernelOpts, maxCPUs int) { + k.init(opts, maxCPUs) } // Halt halts execution. @@ -49,6 +49,11 @@ func (defaultHooks) KernelException(Vector) { // kernelSyscall is a trampoline. // +// When in amd64, it is called with %rip on the upper half, so it can +// NOT access to any global data which is not mapped on upper and must +// call to function pointers or interfaces to switch to the lower half +// so that callee can access to global data. +// // +checkescape:hard,stack // //go:nosplit @@ -58,6 +63,11 @@ func kernelSyscall(c *CPU) { // kernelException is a trampoline. // +// When in amd64, it is called with %rip on the upper half, so it can +// NOT access to any global data which is not mapped on upper and must +// call to function pointers or interfaces to switch to the lower half +// so that callee can access to global data. +// // +checkescape:hard,stack // //go:nosplit @@ -68,10 +78,10 @@ func kernelException(c *CPU, vector Vector) { // Init initializes a new CPU. // // Init allows embedding in other objects. -func (c *CPU) Init(k *Kernel, hooks Hooks) { - c.self = c // Set self reference. - c.kernel = k // Set kernel reference. - c.init() // Perform architectural init. +func (c *CPU) Init(k *Kernel, cpuID int, hooks Hooks) { + c.self = c // Set self reference. + c.kernel = k // Set kernel reference. + c.init(cpuID) // Perform architectural init. // Require hooks. if hooks != nil { diff --git a/pkg/sentry/platform/ring0/kernel_amd64.go b/pkg/sentry/platform/ring0/kernel_amd64.go index d37981dbf..3a9dff4cc 100644 --- a/pkg/sentry/platform/ring0/kernel_amd64.go +++ b/pkg/sentry/platform/ring0/kernel_amd64.go @@ -18,13 +18,42 @@ package ring0 import ( "encoding/binary" + "reflect" + + "gvisor.dev/gvisor/pkg/usermem" ) // init initializes architecture-specific state. -func (k *Kernel) init(opts KernelOpts) { +func (k *Kernel) init(opts KernelOpts, maxCPUs int) { // Save the root page tables. k.PageTables = opts.PageTables + entrySize := reflect.TypeOf(kernelEntry{}).Size() + var ( + entries []kernelEntry + padding = 1 + ) + for { + entries = make([]kernelEntry, maxCPUs+padding-1) + totalSize := entrySize * uintptr(maxCPUs+padding-1) + addr := reflect.ValueOf(&entries[0]).Pointer() + if addr&(usermem.PageSize-1) == 0 && totalSize >= usermem.PageSize { + // The runtime forces power-of-2 alignment for allocations, and we are therefore + // safe once the first address is aligned and the chunk is at least a full page. + break + } + padding = padding << 1 + } + k.cpuEntries = entries + + k.globalIDT = &idt64{} + if reflect.TypeOf(idt64{}).Size() != usermem.PageSize { + panic("Size of globalIDT should be PageSize") + } + if reflect.ValueOf(k.globalIDT).Pointer()&(usermem.PageSize-1) != 0 { + panic("Allocated globalIDT should be page aligned") + } + // Setup the IDT, which is uniform. for v, handler := range handlers { // Allow Breakpoint and Overflow to be called from all @@ -39,8 +68,26 @@ func (k *Kernel) init(opts KernelOpts) { } } +func (k *Kernel) EntryRegions() map[uintptr]uintptr { + regions := make(map[uintptr]uintptr) + + addr := reflect.ValueOf(&k.cpuEntries[0]).Pointer() + size := reflect.TypeOf(kernelEntry{}).Size() * uintptr(len(k.cpuEntries)) + end, _ := usermem.Addr(addr + size).RoundUp() + regions[uintptr(usermem.Addr(addr).RoundDown())] = uintptr(end) + + addr = reflect.ValueOf(k.globalIDT).Pointer() + size = reflect.TypeOf(idt64{}).Size() + end, _ = usermem.Addr(addr + size).RoundUp() + regions[uintptr(usermem.Addr(addr).RoundDown())] = uintptr(end) + + return regions +} + // init initializes architecture-specific state. -func (c *CPU) init() { +func (c *CPU) init(cpuID int) { + c.kernelEntry = &c.kernel.cpuEntries[cpuID] + c.cpuSelf = c // Null segment. c.gdt[0].setNull() @@ -65,6 +112,7 @@ func (c *CPU) init() { // Set the kernel stack pointer in the TSS (virtual address). stackAddr := c.StackTop() + c.stackTop = stackAddr c.tss.rsp0Lo = uint32(stackAddr) c.tss.rsp0Hi = uint32(stackAddr >> 32) c.tss.ist1Lo = uint32(stackAddr) @@ -183,7 +231,7 @@ func IsCanonical(addr uint64) bool { //go:nosplit func (c *CPU) SwitchToUser(switchOpts SwitchOpts) (vector Vector) { userCR3 := switchOpts.PageTables.CR3(!switchOpts.Flush, switchOpts.UserPCID) - kernelCR3 := c.kernel.PageTables.CR3(true, switchOpts.KernelPCID) + c.kernelCR3 = uintptr(c.kernel.PageTables.CR3(true, switchOpts.KernelPCID)) // Sanitize registers. regs := switchOpts.Registers @@ -197,15 +245,11 @@ func (c *CPU) SwitchToUser(switchOpts SwitchOpts) (vector Vector) { WriteFS(uintptr(regs.Fs_base)) // escapes: no. Set application FS. WriteGS(uintptr(regs.Gs_base)) // escapes: no. Set application GS. LoadFloatingPoint(switchOpts.FloatingPointState) // escapes: no. Copy in floating point. - jumpToKernel() // Switch to upper half. - writeCR3(uintptr(userCR3)) // Change to user address space. if switchOpts.FullRestore { - vector = iret(c, regs) + vector = iret(c, regs, uintptr(userCR3)) } else { - vector = sysret(c, regs) + vector = sysret(c, regs, uintptr(userCR3)) } - writeCR3(uintptr(kernelCR3)) // Return to kernel address space. - jumpToUser() // Return to lower half. SaveFloatingPoint(switchOpts.FloatingPointState) // escapes: no. Copy out floating point. WriteFS(uintptr(c.registers.Fs_base)) // escapes: no. Restore kernel FS. return @@ -219,7 +263,7 @@ func (c *CPU) SwitchToUser(switchOpts SwitchOpts) (vector Vector) { //go:nosplit func start(c *CPU) { // Save per-cpu & FS segment. - WriteGS(kernelAddr(c)) + WriteGS(kernelAddr(c.kernelEntry)) WriteFS(uintptr(c.registers.Fs_base)) // Initialize floating point. diff --git a/pkg/sentry/platform/ring0/kernel_arm64.go b/pkg/sentry/platform/ring0/kernel_arm64.go index d0afa1aaa..0ca98a7c7 100644 --- a/pkg/sentry/platform/ring0/kernel_arm64.go +++ b/pkg/sentry/platform/ring0/kernel_arm64.go @@ -25,13 +25,13 @@ func HaltAndResume() func HaltEl1SvcAndResume() // init initializes architecture-specific state. -func (k *Kernel) init(opts KernelOpts) { +func (k *Kernel) init(opts KernelOpts, maxCPUs int) { // Save the root page tables. k.PageTables = opts.PageTables } // init initializes architecture-specific state. -func (c *CPU) init() { +func (c *CPU) init(cpuID int) { // Set the kernel stack pointer(virtual address). c.registers.Sp = uint64(c.StackTop()) @@ -53,6 +53,11 @@ func IsCanonical(addr uint64) bool { //go:nosplit func (c *CPU) SwitchToUser(switchOpts SwitchOpts) (vector Vector) { + storeAppASID(uintptr(switchOpts.UserASID)) + if switchOpts.Flush { + FlushTlbAll() + } + regs := switchOpts.Registers regs.Pstate &= ^uint64(PsrFlagsClear) diff --git a/pkg/sentry/platform/ring0/lib_amd64.go b/pkg/sentry/platform/ring0/lib_amd64.go index ca968a036..0ec5c3bc5 100644 --- a/pkg/sentry/platform/ring0/lib_amd64.go +++ b/pkg/sentry/platform/ring0/lib_amd64.go @@ -61,21 +61,9 @@ func wrgsbase(addr uintptr) // wrgsmsr writes to the GS_BASE MSR. func wrgsmsr(addr uintptr) -// writeCR3 writes the CR3 value. -func writeCR3(phys uintptr) - -// readCR3 reads the current CR3 value. -func readCR3() uintptr - // readCR2 reads the current CR2 value. func readCR2() uintptr -// jumpToKernel jumps to the kernel version of the current RIP. -func jumpToKernel() - -// jumpToUser jumps to the user version of the current RIP. -func jumpToUser() - // fninit initializes the floating point unit. func fninit() diff --git a/pkg/sentry/platform/ring0/lib_amd64.s b/pkg/sentry/platform/ring0/lib_amd64.s index 75d742750..2fe83568a 100644 --- a/pkg/sentry/platform/ring0/lib_amd64.s +++ b/pkg/sentry/platform/ring0/lib_amd64.s @@ -127,53 +127,6 @@ TEXT ·wrgsmsr(SB),NOSPLIT,$0-8 BYTE $0x0f; BYTE $0x30; // WRMSR RET -// jumpToUser changes execution to the user address. -// -// This works by changing the return value to the user version. -TEXT ·jumpToUser(SB),NOSPLIT,$0 - MOVQ 0(SP), AX - MOVQ ·KernelStartAddress(SB), BX - NOTQ BX - ANDQ BX, SP // Switch the stack. - ANDQ BX, BP // Switch the frame pointer. - ANDQ BX, AX // Future return value. - MOVQ AX, 0(SP) - RET - -// jumpToKernel changes execution to the kernel address space. -// -// This works by changing the return value to the kernel version. -TEXT ·jumpToKernel(SB),NOSPLIT,$0 - MOVQ 0(SP), AX - MOVQ ·KernelStartAddress(SB), BX - ORQ BX, SP // Switch the stack. - ORQ BX, BP // Switch the frame pointer. - ORQ BX, AX // Future return value. - MOVQ AX, 0(SP) - RET - -// writeCR3 writes the given CR3 value. -// -// The code corresponds to: -// -// mov %rax, %cr3 -// -TEXT ·writeCR3(SB),NOSPLIT,$0-8 - MOVQ cr3+0(FP), AX - BYTE $0x0f; BYTE $0x22; BYTE $0xd8; - RET - -// readCR3 reads the current CR3 value. -// -// The code corresponds to: -// -// mov %cr3, %rax -// -TEXT ·readCR3(SB),NOSPLIT,$0-8 - BYTE $0x0f; BYTE $0x20; BYTE $0xd8; - MOVQ AX, ret+0(FP) - RET - // readCR2 reads the current CR2 value. // // The code corresponds to: diff --git a/pkg/sentry/platform/ring0/lib_arm64.go b/pkg/sentry/platform/ring0/lib_arm64.go index 00e52c8af..2f1abcb0f 100644 --- a/pkg/sentry/platform/ring0/lib_arm64.go +++ b/pkg/sentry/platform/ring0/lib_arm64.go @@ -16,6 +16,15 @@ package ring0 +// storeAppASID writes the application's asid value. +func storeAppASID(asid uintptr) + +// LocalFlushTlbAll same as FlushTlbAll, but only applies to the calling CPU. +func LocalFlushTlbAll() + +// FlushTlbAll flush all tlb. +func FlushTlbAll() + // CPACREL1 returns the value of the CPACR_EL1 register. func CPACREL1() (value uintptr) diff --git a/pkg/sentry/platform/ring0/lib_arm64.s b/pkg/sentry/platform/ring0/lib_arm64.s index 86bfbe46f..8aabf7d0e 100644 --- a/pkg/sentry/platform/ring0/lib_arm64.s +++ b/pkg/sentry/platform/ring0/lib_arm64.s @@ -15,6 +15,20 @@ #include "funcdata.h" #include "textflag.h" +TEXT ·LocalFlushTlbAll(SB),NOSPLIT,$0 + DSB $6 // dsb(nshst) + WORD $0xd508871f // __tlbi(vmalle1) + DSB $7 // dsb(nsh) + ISB $15 + RET + +TEXT ·FlushTlbAll(SB),NOSPLIT,$0 + DSB $10 // dsb(ishst) + WORD $0xd508831f // __tlbi(vmalle1is) + DSB $11 // dsb(ish) + ISB $15 + RET + TEXT ·GetTLS(SB),NOSPLIT,$0-8 MRS TPIDR_EL0, R1 MOVD R1, ret+0(FP) diff --git a/pkg/sentry/platform/ring0/offsets_amd64.go b/pkg/sentry/platform/ring0/offsets_amd64.go index b8ab120a0..bcb73cb31 100644 --- a/pkg/sentry/platform/ring0/offsets_amd64.go +++ b/pkg/sentry/platform/ring0/offsets_amd64.go @@ -30,11 +30,18 @@ func Emit(w io.Writer) { c := &CPU{} fmt.Fprintf(w, "\n// CPU offsets.\n") - fmt.Fprintf(w, "#define CPU_SELF 0x%02x\n", reflect.ValueOf(&c.self).Pointer()-reflect.ValueOf(c).Pointer()) fmt.Fprintf(w, "#define CPU_REGISTERS 0x%02x\n", reflect.ValueOf(&c.registers).Pointer()-reflect.ValueOf(c).Pointer()) - fmt.Fprintf(w, "#define CPU_STACK_TOP 0x%02x\n", reflect.ValueOf(&c.stack[0]).Pointer()-reflect.ValueOf(c).Pointer()+uintptr(len(c.stack))) fmt.Fprintf(w, "#define CPU_ERROR_CODE 0x%02x\n", reflect.ValueOf(&c.errorCode).Pointer()-reflect.ValueOf(c).Pointer()) fmt.Fprintf(w, "#define CPU_ERROR_TYPE 0x%02x\n", reflect.ValueOf(&c.errorType).Pointer()-reflect.ValueOf(c).Pointer()) + fmt.Fprintf(w, "#define CPU_ENTRY 0x%02x\n", reflect.ValueOf(&c.kernelEntry).Pointer()-reflect.ValueOf(c).Pointer()) + + e := &kernelEntry{} + fmt.Fprintf(w, "\n// CPU entry offsets.\n") + fmt.Fprintf(w, "#define ENTRY_SCRATCH0 0x%02x\n", reflect.ValueOf(&e.scratch0).Pointer()-reflect.ValueOf(e).Pointer()) + fmt.Fprintf(w, "#define ENTRY_SCRATCH1 0x%02x\n", reflect.ValueOf(&e.scratch1).Pointer()-reflect.ValueOf(e).Pointer()) + fmt.Fprintf(w, "#define ENTRY_STACK_TOP 0x%02x\n", reflect.ValueOf(&e.stackTop).Pointer()-reflect.ValueOf(e).Pointer()) + fmt.Fprintf(w, "#define ENTRY_CPU_SELF 0x%02x\n", reflect.ValueOf(&e.cpuSelf).Pointer()-reflect.ValueOf(e).Pointer()) + fmt.Fprintf(w, "#define ENTRY_KERNEL_CR3 0x%02x\n", reflect.ValueOf(&e.kernelCR3).Pointer()-reflect.ValueOf(e).Pointer()) fmt.Fprintf(w, "\n// Bits.\n") fmt.Fprintf(w, "#define _RFLAGS_IF 0x%02x\n", _RFLAGS_IF) diff --git a/pkg/sentry/platform/ring0/offsets_arm64.go b/pkg/sentry/platform/ring0/offsets_arm64.go index f3de962f0..1d86b4bcf 100644 --- a/pkg/sentry/platform/ring0/offsets_arm64.go +++ b/pkg/sentry/platform/ring0/offsets_arm64.go @@ -41,6 +41,7 @@ func Emit(w io.Writer) { fmt.Fprintf(w, "#define CPU_VECTOR_CODE 0x%02x\n", reflect.ValueOf(&c.vecCode).Pointer()-reflect.ValueOf(c).Pointer()) fmt.Fprintf(w, "#define CPU_APP_ADDR 0x%02x\n", reflect.ValueOf(&c.appAddr).Pointer()-reflect.ValueOf(c).Pointer()) fmt.Fprintf(w, "#define CPU_LAZY_VFP 0x%02x\n", reflect.ValueOf(&c.lazyVFP).Pointer()-reflect.ValueOf(c).Pointer()) + fmt.Fprintf(w, "#define CPU_APP_ASID 0x%02x\n", reflect.ValueOf(&c.appASID).Pointer()-reflect.ValueOf(c).Pointer()) fmt.Fprintf(w, "\n// Bits.\n") fmt.Fprintf(w, "#define _KERNEL_FLAGS 0x%02x\n", KernelFlagsSet) diff --git a/pkg/sentry/platform/ring0/x86.go b/pkg/sentry/platform/ring0/x86.go index 9da0ea685..e99da0b35 100644 --- a/pkg/sentry/platform/ring0/x86.go +++ b/pkg/sentry/platform/ring0/x86.go @@ -104,7 +104,7 @@ const ( VirtualizationException SecurityException = 0x1e SyscallInt80 = 0x80 - _NR_INTERRUPTS = SyscallInt80 + 1 + _NR_INTERRUPTS = 0x100 ) // System call vectors. diff --git a/pkg/sentry/socket/BUILD b/pkg/sentry/socket/BUILD index c0fd3425b..a3f775d15 100644 --- a/pkg/sentry/socket/BUILD +++ b/pkg/sentry/socket/BUILD @@ -10,6 +10,7 @@ go_library( "//pkg/abi/linux", "//pkg/binary", "//pkg/context", + "//pkg/marshal", "//pkg/sentry/device", "//pkg/sentry/fs", "//pkg/sentry/fs/fsutil", @@ -20,6 +21,5 @@ go_library( "//pkg/syserr", "//pkg/tcpip", "//pkg/usermem", - "//tools/go_marshal/marshal", ], ) diff --git a/pkg/sentry/socket/hostinet/BUILD b/pkg/sentry/socket/hostinet/BUILD index e76e498de..b6ebe29d6 100644 --- a/pkg/sentry/socket/hostinet/BUILD +++ b/pkg/sentry/socket/hostinet/BUILD @@ -21,6 +21,8 @@ go_library( "//pkg/context", "//pkg/fdnotifier", "//pkg/log", + "//pkg/marshal", + "//pkg/marshal/primitive", "//pkg/safemem", "//pkg/sentry/arch", "//pkg/sentry/device", @@ -37,11 +39,12 @@ go_library( "//pkg/sentry/vfs", "//pkg/syserr", "//pkg/syserror", + "//pkg/tcpip", + "//pkg/tcpip/network/ipv4", + "//pkg/tcpip/network/ipv6", "//pkg/tcpip/stack", "//pkg/usermem", "//pkg/waiter", - "//tools/go_marshal/marshal", - "//tools/go_marshal/primitive", "@org_golang_x_sys//unix:go_default_library", ], ) diff --git a/pkg/sentry/socket/hostinet/socket.go b/pkg/sentry/socket/hostinet/socket.go index 242e6bf76..7d3c4a01c 100644 --- a/pkg/sentry/socket/hostinet/socket.go +++ b/pkg/sentry/socket/hostinet/socket.go @@ -24,6 +24,8 @@ import ( "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/fdnotifier" "gvisor.dev/gvisor/pkg/log" + "gvisor.dev/gvisor/pkg/marshal" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/safemem" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/fs" @@ -36,8 +38,6 @@ import ( "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/usermem" "gvisor.dev/gvisor/pkg/waiter" - "gvisor.dev/gvisor/tools/go_marshal/marshal" - "gvisor.dev/gvisor/tools/go_marshal/primitive" ) const ( diff --git a/pkg/sentry/socket/hostinet/socket_vfs2.go b/pkg/sentry/socket/hostinet/socket_vfs2.go index 8a1d52ebf..163af329b 100644 --- a/pkg/sentry/socket/hostinet/socket_vfs2.go +++ b/pkg/sentry/socket/hostinet/socket_vfs2.go @@ -52,6 +52,7 @@ var _ = socket.SocketVFS2(&socketVFS2{}) func newVFS2Socket(t *kernel.Task, family int, stype linux.SockType, protocol int, fd int, flags uint32) (*vfs.FileDescription, *syserr.Error) { mnt := t.Kernel().SocketMount() d := sockfs.NewDentry(t.Credentials(), mnt) + defer d.DecRef(t) s := &socketVFS2{ socketOpsCommon: socketOpsCommon{ @@ -77,6 +78,13 @@ func newVFS2Socket(t *kernel.Task, family int, stype linux.SockType, protocol in return vfsfd, nil } +// Release implements vfs.FileDescriptionImpl.Release. +func (s *socketVFS2) Release(ctx context.Context) { + t := kernel.TaskFromContext(ctx) + t.Kernel().DeleteSocketVFS2(&s.vfsfd) + s.socketOpsCommon.Release(ctx) +} + // Readiness implements waiter.Waitable.Readiness. func (s *socketVFS2) Readiness(mask waiter.EventMask) waiter.EventMask { return s.socketOpsCommon.Readiness(mask) @@ -97,11 +105,6 @@ func (s *socketVFS2) Ioctl(ctx context.Context, uio usermem.IO, args arch.Syscal return ioctl(ctx, s.fd, uio, args) } -// Allocate implements vfs.FileDescriptionImpl.Allocate. -func (s *socketVFS2) Allocate(ctx context.Context, mode, offset, length uint64) error { - return syserror.ENODEV -} - // PRead implements vfs.FileDescriptionImpl.PRead. func (s *socketVFS2) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) { return 0, syserror.ESPIPE diff --git a/pkg/sentry/socket/hostinet/stack.go b/pkg/sentry/socket/hostinet/stack.go index fda3dcb35..faa61160e 100644 --- a/pkg/sentry/socket/hostinet/stack.go +++ b/pkg/sentry/socket/hostinet/stack.go @@ -30,6 +30,9 @@ import ( "gvisor.dev/gvisor/pkg/sentry/inet" "gvisor.dev/gvisor/pkg/syserr" "gvisor.dev/gvisor/pkg/syserror" + "gvisor.dev/gvisor/pkg/tcpip" + "gvisor.dev/gvisor/pkg/tcpip/network/ipv4" + "gvisor.dev/gvisor/pkg/tcpip/network/ipv6" "gvisor.dev/gvisor/pkg/tcpip/stack" "gvisor.dev/gvisor/pkg/usermem" ) @@ -59,6 +62,8 @@ type Stack struct { tcpSACKEnabled bool netDevFile *os.File netSNMPFile *os.File + ipv4Forwarding bool + ipv6Forwarding bool } // NewStack returns an empty Stack containing no configuration. @@ -118,6 +123,13 @@ func (s *Stack) Configure() error { s.netSNMPFile = f } + s.ipv6Forwarding = false + if ipForwarding, err := ioutil.ReadFile("/proc/sys/net/ipv6/conf/all/forwarding"); err == nil { + s.ipv6Forwarding = strings.TrimSpace(string(ipForwarding)) != "0" + } else { + log.Warningf("Failed to read if ipv6 forwarding is enabled, setting to false") + } + return nil } @@ -468,3 +480,21 @@ func (s *Stack) CleanupEndpoints() []stack.TransportEndpoint { return nil } // RestoreCleanupEndpoints implements inet.Stack.RestoreCleanupEndpoints. func (s *Stack) RestoreCleanupEndpoints([]stack.TransportEndpoint) {} + +// Forwarding implements inet.Stack.Forwarding. +func (s *Stack) Forwarding(protocol tcpip.NetworkProtocolNumber) bool { + switch protocol { + case ipv4.ProtocolNumber: + return s.ipv4Forwarding + case ipv6.ProtocolNumber: + return s.ipv6Forwarding + default: + log.Warningf("Forwarding(%v) failed: unsupported protocol", protocol) + return false + } +} + +// SetForwarding implements inet.Stack.SetForwarding. +func (s *Stack) SetForwarding(protocol tcpip.NetworkProtocolNumber, enable bool) error { + return syserror.EACCES +} diff --git a/pkg/sentry/socket/netfilter/extensions.go b/pkg/sentry/socket/netfilter/extensions.go index 0336a32d8..549787955 100644 --- a/pkg/sentry/socket/netfilter/extensions.go +++ b/pkg/sentry/socket/netfilter/extensions.go @@ -19,6 +19,8 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/binary" + "gvisor.dev/gvisor/pkg/syserr" + "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/tcpip/stack" "gvisor.dev/gvisor/pkg/usermem" ) @@ -37,7 +39,7 @@ type matchMaker interface { // name is the matcher name as stored in the xt_entry_match struct. name() string - // marshal converts from an stack.Matcher to an ABI struct. + // marshal converts from a stack.Matcher to an ABI struct. marshal(matcher stack.Matcher) []byte // unmarshal converts from the ABI matcher struct to an @@ -93,3 +95,71 @@ func unmarshalMatcher(match linux.XTEntryMatch, filter stack.IPHeaderFilter, buf } return matchMaker.unmarshal(buf, filter) } + +// targetMaker knows how to (un)marshal a target. Once registered, +// marshalTarget and unmarshalTarget can be used. +type targetMaker interface { + // id uniquely identifies the target. + id() stack.TargetID + + // marshal converts from a stack.Target to an ABI struct. + marshal(target stack.Target) []byte + + // unmarshal converts from the ABI matcher struct to a stack.Target. + unmarshal(buf []byte, filter stack.IPHeaderFilter) (stack.Target, *syserr.Error) +} + +// targetMakers maps the TargetID of supported targets to the targetMaker that +// marshals and unmarshals it. It is immutable after package initialization. +var targetMakers = map[stack.TargetID]targetMaker{} + +func targetRevision(name string, netProto tcpip.NetworkProtocolNumber, rev uint8) (uint8, bool) { + tid := stack.TargetID{ + Name: name, + NetworkProtocol: netProto, + Revision: rev, + } + if _, ok := targetMakers[tid]; !ok { + return 0, false + } + + // Return the highest supported revision unless rev is higher. + for _, other := range targetMakers { + otherID := other.id() + if name == otherID.Name && netProto == otherID.NetworkProtocol && otherID.Revision > rev { + rev = uint8(otherID.Revision) + } + } + return rev, true +} + +// registerTargetMaker should be called by target extensions to register them +// with the netfilter package. +func registerTargetMaker(tm targetMaker) { + if _, ok := targetMakers[tm.id()]; ok { + panic(fmt.Sprintf("multiple targets registered with name %q.", tm.id())) + } + targetMakers[tm.id()] = tm +} + +func marshalTarget(target stack.Target) []byte { + targetMaker, ok := targetMakers[target.ID()] + if !ok { + panic(fmt.Sprintf("unknown target of type %T with id %+v.", target, target.ID())) + } + return targetMaker.marshal(target) +} + +func unmarshalTarget(target linux.XTEntryTarget, filter stack.IPHeaderFilter, buf []byte) (stack.Target, *syserr.Error) { + tid := stack.TargetID{ + Name: target.Name.String(), + NetworkProtocol: filter.NetworkProtocol(), + Revision: target.Revision, + } + targetMaker, ok := targetMakers[tid] + if !ok { + nflog("unsupported target with name %q", target.Name.String()) + return nil, syserr.ErrInvalidArgument + } + return targetMaker.unmarshal(buf, filter) +} diff --git a/pkg/sentry/socket/netfilter/ipv4.go b/pkg/sentry/socket/netfilter/ipv4.go index e4c55a100..b560fae0d 100644 --- a/pkg/sentry/socket/netfilter/ipv4.go +++ b/pkg/sentry/socket/netfilter/ipv4.go @@ -181,18 +181,23 @@ func modifyEntries4(stk *stack.Stack, optVal []byte, replace *linux.IPTReplace, nflog("entry doesn't have enough room for its target (only %d bytes remain)", len(optVal)) return nil, syserr.ErrInvalidArgument } - target, err := parseTarget(filter, optVal[:targetSize]) - if err != nil { - nflog("failed to parse target: %v", err) - return nil, syserr.ErrInvalidArgument - } - optVal = optVal[targetSize:] - table.Rules = append(table.Rules, stack.Rule{ + rule := stack.Rule{ Filter: filter, - Target: target, Matchers: matchers, - }) + } + + { + target, err := parseTarget(filter, optVal[:targetSize], false /* ipv6 */) + if err != nil { + nflog("failed to parse target: %v", err) + return nil, err + } + rule.Target = target + } + optVal = optVal[targetSize:] + + table.Rules = append(table.Rules, rule) offsets[offset] = int(entryIdx) offset += uint32(entry.NextOffset) diff --git a/pkg/sentry/socket/netfilter/ipv6.go b/pkg/sentry/socket/netfilter/ipv6.go index 3b2c1becd..4253f7bf4 100644 --- a/pkg/sentry/socket/netfilter/ipv6.go +++ b/pkg/sentry/socket/netfilter/ipv6.go @@ -184,18 +184,23 @@ func modifyEntries6(stk *stack.Stack, optVal []byte, replace *linux.IPTReplace, nflog("entry doesn't have enough room for its target (only %d bytes remain)", len(optVal)) return nil, syserr.ErrInvalidArgument } - target, err := parseTarget(filter, optVal[:targetSize]) - if err != nil { - nflog("failed to parse target: %v", err) - return nil, syserr.ErrInvalidArgument - } - optVal = optVal[targetSize:] - table.Rules = append(table.Rules, stack.Rule{ + rule := stack.Rule{ Filter: filter, - Target: target, Matchers: matchers, - }) + } + + { + target, err := parseTarget(filter, optVal[:targetSize], true /* ipv6 */) + if err != nil { + nflog("failed to parse target: %v", err) + return nil, err + } + rule.Target = target + } + optVal = optVal[targetSize:] + + table.Rules = append(table.Rules, rule) offsets[offset] = int(entryIdx) offset += uint32(entry.NextOffset) diff --git a/pkg/sentry/socket/netfilter/netfilter.go b/pkg/sentry/socket/netfilter/netfilter.go index 3e1735079..904a12e38 100644 --- a/pkg/sentry/socket/netfilter/netfilter.go +++ b/pkg/sentry/socket/netfilter/netfilter.go @@ -25,6 +25,7 @@ import ( "gvisor.dev/gvisor/pkg/log" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/syserr" + "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/tcpip/stack" "gvisor.dev/gvisor/pkg/usermem" ) @@ -195,7 +196,7 @@ func SetEntries(stk *stack.Stack, optVal []byte, ipv6 bool) *syserr.Error { // Check the user chains. for ruleIdx, rule := range table.Rules { - if _, ok := rule.Target.(stack.UserChainTarget); !ok { + if _, ok := rule.Target.(*stack.UserChainTarget); !ok { continue } @@ -216,7 +217,7 @@ func SetEntries(stk *stack.Stack, optVal []byte, ipv6 bool) *syserr.Error { // Set each jump to point to the appropriate rule. Right now they hold byte // offsets. for ruleIdx, rule := range table.Rules { - jump, ok := rule.Target.(JumpTarget) + jump, ok := rule.Target.(*JumpTarget) if !ok { continue } @@ -307,7 +308,7 @@ func validUnderflow(rule stack.Rule, ipv6 bool) bool { return false } switch rule.Target.(type) { - case stack.AcceptTarget, stack.DropTarget: + case *stack.AcceptTarget, *stack.DropTarget: return true default: return false @@ -318,7 +319,7 @@ func isUnconditionalAccept(rule stack.Rule, ipv6 bool) bool { if !validUnderflow(rule, ipv6) { return false } - _, ok := rule.Target.(stack.AcceptTarget) + _, ok := rule.Target.(*stack.AcceptTarget) return ok } @@ -337,3 +338,20 @@ func hookFromLinux(hook int) stack.Hook { } panic(fmt.Sprintf("Unknown hook %d does not correspond to a builtin chain", hook)) } + +// TargetRevision returns a linux.XTGetRevision for a given target. It sets +// Revision to the highest supported value, unless the provided revision number +// is larger. +func TargetRevision(t *kernel.Task, revPtr usermem.Addr, netProto tcpip.NetworkProtocolNumber) (linux.XTGetRevision, *syserr.Error) { + // Read in the target name and version. + var rev linux.XTGetRevision + if _, err := rev.CopyIn(t, revPtr); err != nil { + return linux.XTGetRevision{}, syserr.FromError(err) + } + maxSupported, ok := targetRevision(rev.Name.String(), netProto, rev.Revision) + if !ok { + return linux.XTGetRevision{}, syserr.ErrProtocolNotSupported + } + rev.Revision = maxSupported + return rev, nil +} diff --git a/pkg/sentry/socket/netfilter/targets.go b/pkg/sentry/socket/netfilter/targets.go index 87e41abd8..0e14447fe 100644 --- a/pkg/sentry/socket/netfilter/targets.go +++ b/pkg/sentry/socket/netfilter/targets.go @@ -15,255 +15,357 @@ package netfilter import ( - "errors" "fmt" "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/binary" + "gvisor.dev/gvisor/pkg/syserr" "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/tcpip/header" "gvisor.dev/gvisor/pkg/tcpip/stack" "gvisor.dev/gvisor/pkg/usermem" ) -// errorTargetName is used to mark targets as error targets. Error targets -// shouldn't be reached - an error has occurred if we fall through to one. -const errorTargetName = "ERROR" +func init() { + // Standard targets include ACCEPT, DROP, RETURN, and JUMP. + registerTargetMaker(&standardTargetMaker{ + NetworkProtocol: header.IPv4ProtocolNumber, + }) + registerTargetMaker(&standardTargetMaker{ + NetworkProtocol: header.IPv6ProtocolNumber, + }) + + // Both user chains and actual errors are represented in iptables by + // error targets. + registerTargetMaker(&errorTargetMaker{ + NetworkProtocol: header.IPv4ProtocolNumber, + }) + registerTargetMaker(&errorTargetMaker{ + NetworkProtocol: header.IPv6ProtocolNumber, + }) + + registerTargetMaker(&redirectTargetMaker{ + NetworkProtocol: header.IPv4ProtocolNumber, + }) + registerTargetMaker(&nfNATTargetMaker{ + NetworkProtocol: header.IPv6ProtocolNumber, + }) +} -// redirectTargetName is used to mark targets as redirect targets. Redirect -// targets should be reached for only NAT and Mangle tables. These targets will -// change the destination port/destination IP for packets. -const redirectTargetName = "REDIRECT" +type standardTargetMaker struct { + NetworkProtocol tcpip.NetworkProtocolNumber +} -func marshalTarget(target stack.Target) []byte { +func (sm *standardTargetMaker) id() stack.TargetID { + // Standard targets have the empty string as a name and no revisions. + return stack.TargetID{ + NetworkProtocol: sm.NetworkProtocol, + } +} +func (*standardTargetMaker) marshal(target stack.Target) []byte { + // Translate verdicts the same way as the iptables tool. + var verdict int32 switch tg := target.(type) { - case stack.AcceptTarget: - return marshalStandardTarget(stack.RuleAccept) - case stack.DropTarget: - return marshalStandardTarget(stack.RuleDrop) - case stack.ErrorTarget: - return marshalErrorTarget(errorTargetName) - case stack.UserChainTarget: - return marshalErrorTarget(tg.Name) - case stack.ReturnTarget: - return marshalStandardTarget(stack.RuleReturn) - case stack.RedirectTarget: - return marshalRedirectTarget(tg) - case JumpTarget: - return marshalJumpTarget(tg) + case *stack.AcceptTarget: + verdict = -linux.NF_ACCEPT - 1 + case *stack.DropTarget: + verdict = -linux.NF_DROP - 1 + case *stack.ReturnTarget: + verdict = linux.NF_RETURN + case *JumpTarget: + verdict = int32(tg.Offset) default: panic(fmt.Errorf("unknown target of type %T", target)) } -} - -func marshalStandardTarget(verdict stack.RuleVerdict) []byte { - nflog("convert to binary: marshalling standard target") // The target's name will be the empty string. - target := linux.XTStandardTarget{ + xt := linux.XTStandardTarget{ Target: linux.XTEntryTarget{ TargetSize: linux.SizeOfXTStandardTarget, }, - Verdict: translateFromStandardVerdict(verdict), + Verdict: verdict, } ret := make([]byte, 0, linux.SizeOfXTStandardTarget) - return binary.Marshal(ret, usermem.ByteOrder, target) + return binary.Marshal(ret, usermem.ByteOrder, xt) +} + +func (*standardTargetMaker) unmarshal(buf []byte, filter stack.IPHeaderFilter) (stack.Target, *syserr.Error) { + if len(buf) != linux.SizeOfXTStandardTarget { + nflog("buf has wrong size for standard target %d", len(buf)) + return nil, syserr.ErrInvalidArgument + } + var standardTarget linux.XTStandardTarget + buf = buf[:linux.SizeOfXTStandardTarget] + binary.Unmarshal(buf, usermem.ByteOrder, &standardTarget) + + if standardTarget.Verdict < 0 { + // A Verdict < 0 indicates a non-jump verdict. + return translateToStandardTarget(standardTarget.Verdict, filter.NetworkProtocol()) + } + // A verdict >= 0 indicates a jump. + return &JumpTarget{ + Offset: uint32(standardTarget.Verdict), + NetworkProtocol: filter.NetworkProtocol(), + }, nil +} + +type errorTargetMaker struct { + NetworkProtocol tcpip.NetworkProtocolNumber +} + +func (em *errorTargetMaker) id() stack.TargetID { + // Error targets have no revision. + return stack.TargetID{ + Name: stack.ErrorTargetName, + NetworkProtocol: em.NetworkProtocol, + } } -func marshalErrorTarget(errorName string) []byte { +func (*errorTargetMaker) marshal(target stack.Target) []byte { + var errorName string + switch tg := target.(type) { + case *stack.ErrorTarget: + errorName = stack.ErrorTargetName + case *stack.UserChainTarget: + errorName = tg.Name + default: + panic(fmt.Sprintf("errorMakerTarget cannot marshal unknown type %T", target)) + } + // This is an error target named error - target := linux.XTErrorTarget{ + xt := linux.XTErrorTarget{ Target: linux.XTEntryTarget{ TargetSize: linux.SizeOfXTErrorTarget, }, } - copy(target.Name[:], errorName) - copy(target.Target.Name[:], errorTargetName) + copy(xt.Name[:], errorName) + copy(xt.Target.Name[:], stack.ErrorTargetName) ret := make([]byte, 0, linux.SizeOfXTErrorTarget) - return binary.Marshal(ret, usermem.ByteOrder, target) + return binary.Marshal(ret, usermem.ByteOrder, xt) } -func marshalRedirectTarget(rt stack.RedirectTarget) []byte { +func (*errorTargetMaker) unmarshal(buf []byte, filter stack.IPHeaderFilter) (stack.Target, *syserr.Error) { + if len(buf) != linux.SizeOfXTErrorTarget { + nflog("buf has insufficient size for error target %d", len(buf)) + return nil, syserr.ErrInvalidArgument + } + var errorTarget linux.XTErrorTarget + buf = buf[:linux.SizeOfXTErrorTarget] + binary.Unmarshal(buf, usermem.ByteOrder, &errorTarget) + + // Error targets are used in 2 cases: + // * An actual error case. These rules have an error + // named stack.ErrorTargetName. The last entry of the table + // is usually an error case to catch any packets that + // somehow fall through every rule. + // * To mark the start of a user defined chain. These + // rules have an error with the name of the chain. + switch name := errorTarget.Name.String(); name { + case stack.ErrorTargetName: + return &stack.ErrorTarget{NetworkProtocol: filter.NetworkProtocol()}, nil + default: + // User defined chain. + return &stack.UserChainTarget{ + Name: name, + NetworkProtocol: filter.NetworkProtocol(), + }, nil + } +} + +type redirectTargetMaker struct { + NetworkProtocol tcpip.NetworkProtocolNumber +} + +func (rm *redirectTargetMaker) id() stack.TargetID { + return stack.TargetID{ + Name: stack.RedirectTargetName, + NetworkProtocol: rm.NetworkProtocol, + } +} + +func (*redirectTargetMaker) marshal(target stack.Target) []byte { + rt := target.(*stack.RedirectTarget) // This is a redirect target named redirect - target := linux.XTRedirectTarget{ + xt := linux.XTRedirectTarget{ Target: linux.XTEntryTarget{ TargetSize: linux.SizeOfXTRedirectTarget, }, } - copy(target.Target.Name[:], redirectTargetName) + copy(xt.Target.Name[:], stack.RedirectTargetName) ret := make([]byte, 0, linux.SizeOfXTRedirectTarget) - target.NfRange.RangeSize = 1 - if rt.RangeProtoSpecified { - target.NfRange.RangeIPV4.Flags |= linux.NF_NAT_RANGE_PROTO_SPECIFIED + xt.NfRange.RangeSize = 1 + xt.NfRange.RangeIPV4.Flags |= linux.NF_NAT_RANGE_PROTO_SPECIFIED + xt.NfRange.RangeIPV4.MinPort = htons(rt.Port) + xt.NfRange.RangeIPV4.MaxPort = xt.NfRange.RangeIPV4.MinPort + return binary.Marshal(ret, usermem.ByteOrder, xt) +} + +func (*redirectTargetMaker) unmarshal(buf []byte, filter stack.IPHeaderFilter) (stack.Target, *syserr.Error) { + if len(buf) < linux.SizeOfXTRedirectTarget { + nflog("redirectTargetMaker: buf has insufficient size for redirect target %d", len(buf)) + return nil, syserr.ErrInvalidArgument + } + + if p := filter.Protocol; p != header.TCPProtocolNumber && p != header.UDPProtocolNumber { + nflog("redirectTargetMaker: bad proto %d", p) + return nil, syserr.ErrInvalidArgument + } + + var redirectTarget linux.XTRedirectTarget + buf = buf[:linux.SizeOfXTRedirectTarget] + binary.Unmarshal(buf, usermem.ByteOrder, &redirectTarget) + + // Copy linux.XTRedirectTarget to stack.RedirectTarget. + target := stack.RedirectTarget{NetworkProtocol: filter.NetworkProtocol()} + + // RangeSize should be 1. + nfRange := redirectTarget.NfRange + if nfRange.RangeSize != 1 { + nflog("redirectTargetMaker: bad rangesize %d", nfRange.RangeSize) + return nil, syserr.ErrInvalidArgument + } + + // TODO(gvisor.dev/issue/170): Check if the flags are valid. + // Also check if we need to map ports or IP. + // For now, redirect target only supports destination port change. + // Port range and IP range are not supported yet. + if nfRange.RangeIPV4.Flags != linux.NF_NAT_RANGE_PROTO_SPECIFIED { + nflog("redirectTargetMaker: invalid range flags %d", nfRange.RangeIPV4.Flags) + return nil, syserr.ErrInvalidArgument + } + + // TODO(gvisor.dev/issue/170): Port range is not supported yet. + if nfRange.RangeIPV4.MinPort != nfRange.RangeIPV4.MaxPort { + nflog("redirectTargetMaker: MinPort != MaxPort (%d, %d)", nfRange.RangeIPV4.MinPort, nfRange.RangeIPV4.MaxPort) + return nil, syserr.ErrInvalidArgument } - // Convert port from little endian to big endian. - port := make([]byte, 2) - binary.LittleEndian.PutUint16(port, rt.MinPort) - target.NfRange.RangeIPV4.MinPort = binary.BigEndian.Uint16(port) - binary.LittleEndian.PutUint16(port, rt.MaxPort) - target.NfRange.RangeIPV4.MaxPort = binary.BigEndian.Uint16(port) - return binary.Marshal(ret, usermem.ByteOrder, target) + if nfRange.RangeIPV4.MinIP != nfRange.RangeIPV4.MaxIP { + nflog("redirectTargetMaker: MinIP != MaxIP (%d, %d)", nfRange.RangeIPV4.MinPort, nfRange.RangeIPV4.MaxPort) + return nil, syserr.ErrInvalidArgument + } + + target.Addr = tcpip.Address(nfRange.RangeIPV4.MinIP[:]) + target.Port = ntohs(nfRange.RangeIPV4.MinPort) + + return &target, nil } -func marshalJumpTarget(jt JumpTarget) []byte { - nflog("convert to binary: marshalling jump target") +type nfNATTarget struct { + Target linux.XTEntryTarget + Range linux.NFNATRange +} - // The target's name will be the empty string. - target := linux.XTStandardTarget{ +const nfNATMarhsalledSize = linux.SizeOfXTEntryTarget + linux.SizeOfNFNATRange + +type nfNATTargetMaker struct { + NetworkProtocol tcpip.NetworkProtocolNumber +} + +func (rm *nfNATTargetMaker) id() stack.TargetID { + return stack.TargetID{ + Name: stack.RedirectTargetName, + NetworkProtocol: rm.NetworkProtocol, + } +} + +func (*nfNATTargetMaker) marshal(target stack.Target) []byte { + rt := target.(*stack.RedirectTarget) + nt := nfNATTarget{ Target: linux.XTEntryTarget{ - TargetSize: linux.SizeOfXTStandardTarget, + TargetSize: nfNATMarhsalledSize, + }, + Range: linux.NFNATRange{ + Flags: linux.NF_NAT_RANGE_PROTO_SPECIFIED, }, - // Verdict is overloaded by the ABI. When positive, it holds - // the jump offset from the start of the table. - Verdict: int32(jt.Offset), } + copy(nt.Target.Name[:], stack.RedirectTargetName) + copy(nt.Range.MinAddr[:], rt.Addr) + copy(nt.Range.MaxAddr[:], rt.Addr) - ret := make([]byte, 0, linux.SizeOfXTStandardTarget) - return binary.Marshal(ret, usermem.ByteOrder, target) + nt.Range.MinProto = htons(rt.Port) + nt.Range.MaxProto = nt.Range.MinProto + + ret := make([]byte, 0, nfNATMarhsalledSize) + return binary.Marshal(ret, usermem.ByteOrder, nt) } -// translateFromStandardVerdict translates verdicts the same way as the iptables -// tool. -func translateFromStandardVerdict(verdict stack.RuleVerdict) int32 { - switch verdict { - case stack.RuleAccept: - return -linux.NF_ACCEPT - 1 - case stack.RuleDrop: - return -linux.NF_DROP - 1 - case stack.RuleReturn: - return linux.NF_RETURN - default: - // TODO(gvisor.dev/issue/170): Support Jump. - panic(fmt.Sprintf("unknown standard verdict: %d", verdict)) +func (*nfNATTargetMaker) unmarshal(buf []byte, filter stack.IPHeaderFilter) (stack.Target, *syserr.Error) { + if size := nfNATMarhsalledSize; len(buf) < size { + nflog("nfNATTargetMaker: buf has insufficient size (%d) for nfNAT target (%d)", len(buf), size) + return nil, syserr.ErrInvalidArgument } + + if p := filter.Protocol; p != header.TCPProtocolNumber && p != header.UDPProtocolNumber { + nflog("nfNATTargetMaker: bad proto %d", p) + return nil, syserr.ErrInvalidArgument + } + + var natRange linux.NFNATRange + buf = buf[linux.SizeOfXTEntryTarget:nfNATMarhsalledSize] + binary.Unmarshal(buf, usermem.ByteOrder, &natRange) + + // We don't support port or address ranges. + if natRange.MinAddr != natRange.MaxAddr { + nflog("nfNATTargetMaker: MinAddr and MaxAddr are different") + return nil, syserr.ErrInvalidArgument + } + if natRange.MinProto != natRange.MaxProto { + nflog("nfNATTargetMaker: MinProto and MaxProto are different") + return nil, syserr.ErrInvalidArgument + } + + // TODO(gvisor.dev/issue/3549): Check for other flags. + // For now, redirect target only supports destination change. + if natRange.Flags != linux.NF_NAT_RANGE_PROTO_SPECIFIED { + nflog("nfNATTargetMaker: invalid range flags %d", natRange.Flags) + return nil, syserr.ErrInvalidArgument + } + + target := stack.RedirectTarget{ + NetworkProtocol: filter.NetworkProtocol(), + Addr: tcpip.Address(natRange.MinAddr[:]), + Port: ntohs(natRange.MinProto), + } + + return &target, nil } // translateToStandardTarget translates from the value in a // linux.XTStandardTarget to an stack.Verdict. -func translateToStandardTarget(val int32) (stack.Target, error) { +func translateToStandardTarget(val int32, netProto tcpip.NetworkProtocolNumber) (stack.Target, *syserr.Error) { // TODO(gvisor.dev/issue/170): Support other verdicts. switch val { case -linux.NF_ACCEPT - 1: - return stack.AcceptTarget{}, nil + return &stack.AcceptTarget{NetworkProtocol: netProto}, nil case -linux.NF_DROP - 1: - return stack.DropTarget{}, nil + return &stack.DropTarget{NetworkProtocol: netProto}, nil case -linux.NF_QUEUE - 1: - return nil, errors.New("unsupported iptables verdict QUEUE") + nflog("unsupported iptables verdict QUEUE") + return nil, syserr.ErrInvalidArgument case linux.NF_RETURN: - return stack.ReturnTarget{}, nil + return &stack.ReturnTarget{NetworkProtocol: netProto}, nil default: - return nil, fmt.Errorf("unknown iptables verdict %d", val) + nflog("unknown iptables verdict %d", val) + return nil, syserr.ErrInvalidArgument } } // parseTarget parses a target from optVal. optVal should contain only the // target. -func parseTarget(filter stack.IPHeaderFilter, optVal []byte) (stack.Target, error) { +func parseTarget(filter stack.IPHeaderFilter, optVal []byte, ipv6 bool) (stack.Target, *syserr.Error) { nflog("set entries: parsing target of size %d", len(optVal)) if len(optVal) < linux.SizeOfXTEntryTarget { - return nil, fmt.Errorf("optVal has insufficient size for entry target %d", len(optVal)) + nflog("optVal has insufficient size for entry target %d", len(optVal)) + return nil, syserr.ErrInvalidArgument } var target linux.XTEntryTarget buf := optVal[:linux.SizeOfXTEntryTarget] binary.Unmarshal(buf, usermem.ByteOrder, &target) - switch target.Name.String() { - case "": - // Standard target. - if len(optVal) != linux.SizeOfXTStandardTarget { - return nil, fmt.Errorf("optVal has wrong size for standard target %d", len(optVal)) - } - var standardTarget linux.XTStandardTarget - buf = optVal[:linux.SizeOfXTStandardTarget] - binary.Unmarshal(buf, usermem.ByteOrder, &standardTarget) - - if standardTarget.Verdict < 0 { - // A Verdict < 0 indicates a non-jump verdict. - return translateToStandardTarget(standardTarget.Verdict) - } - // A verdict >= 0 indicates a jump. - return JumpTarget{Offset: uint32(standardTarget.Verdict)}, nil - - case errorTargetName: - // Error target. - if len(optVal) != linux.SizeOfXTErrorTarget { - return nil, fmt.Errorf("optVal has insufficient size for error target %d", len(optVal)) - } - var errorTarget linux.XTErrorTarget - buf = optVal[:linux.SizeOfXTErrorTarget] - binary.Unmarshal(buf, usermem.ByteOrder, &errorTarget) - - // Error targets are used in 2 cases: - // * An actual error case. These rules have an error - // named errorTargetName. The last entry of the table - // is usually an error case to catch any packets that - // somehow fall through every rule. - // * To mark the start of a user defined chain. These - // rules have an error with the name of the chain. - switch name := errorTarget.Name.String(); name { - case errorTargetName: - nflog("set entries: error target") - return stack.ErrorTarget{}, nil - default: - // User defined chain. - nflog("set entries: user-defined target %q", name) - return stack.UserChainTarget{Name: name}, nil - } - - case redirectTargetName: - // Redirect target. - if len(optVal) < linux.SizeOfXTRedirectTarget { - return nil, fmt.Errorf("netfilter.SetEntries: optVal has insufficient size for redirect target %d", len(optVal)) - } - - if p := filter.Protocol; p != header.TCPProtocolNumber && p != header.UDPProtocolNumber { - return nil, fmt.Errorf("netfilter.SetEntries: bad proto %d", p) - } - - var redirectTarget linux.XTRedirectTarget - buf = optVal[:linux.SizeOfXTRedirectTarget] - binary.Unmarshal(buf, usermem.ByteOrder, &redirectTarget) - - // Copy linux.XTRedirectTarget to stack.RedirectTarget. - var target stack.RedirectTarget - nfRange := redirectTarget.NfRange - - // RangeSize should be 1. - if nfRange.RangeSize != 1 { - return nil, fmt.Errorf("netfilter.SetEntries: bad rangesize %d", nfRange.RangeSize) - } - - // TODO(gvisor.dev/issue/170): Check if the flags are valid. - // Also check if we need to map ports or IP. - // For now, redirect target only supports destination port change. - // Port range and IP range are not supported yet. - if nfRange.RangeIPV4.Flags&linux.NF_NAT_RANGE_PROTO_SPECIFIED == 0 { - return nil, fmt.Errorf("netfilter.SetEntries: invalid range flags %d", nfRange.RangeIPV4.Flags) - } - target.RangeProtoSpecified = true - - target.MinIP = tcpip.Address(nfRange.RangeIPV4.MinIP[:]) - target.MaxIP = tcpip.Address(nfRange.RangeIPV4.MaxIP[:]) - - // TODO(gvisor.dev/issue/170): Port range is not supported yet. - if nfRange.RangeIPV4.MinPort != nfRange.RangeIPV4.MaxPort { - return nil, fmt.Errorf("netfilter.SetEntries: minport != maxport (%d, %d)", nfRange.RangeIPV4.MinPort, nfRange.RangeIPV4.MaxPort) - } - - // Convert port from big endian to little endian. - port := make([]byte, 2) - binary.BigEndian.PutUint16(port, nfRange.RangeIPV4.MinPort) - target.MinPort = binary.LittleEndian.Uint16(port) - - binary.BigEndian.PutUint16(port, nfRange.RangeIPV4.MaxPort) - target.MaxPort = binary.LittleEndian.Uint16(port) - return target, nil - } - // Unknown target. - return nil, fmt.Errorf("unknown target %q doesn't exist or isn't supported yet", target.Name.String()) + return unmarshalTarget(target, filter, optVal) } // JumpTarget implements stack.Target. @@ -274,9 +376,31 @@ type JumpTarget struct { // RuleNum is the rule to jump to. RuleNum int + + // NetworkProtocol is the network protocol the target is used with. + NetworkProtocol tcpip.NetworkProtocolNumber +} + +// ID implements Target.ID. +func (jt *JumpTarget) ID() stack.TargetID { + return stack.TargetID{ + NetworkProtocol: jt.NetworkProtocol, + } } // Action implements stack.Target.Action. -func (jt JumpTarget) Action(*stack.PacketBuffer, *stack.ConnTrack, stack.Hook, *stack.GSO, *stack.Route, tcpip.Address) (stack.RuleVerdict, int) { +func (jt *JumpTarget) Action(*stack.PacketBuffer, *stack.ConnTrack, stack.Hook, *stack.GSO, *stack.Route, tcpip.Address) (stack.RuleVerdict, int) { return stack.RuleJump, jt.RuleNum } + +func ntohs(port uint16) uint16 { + buf := make([]byte, 2) + binary.BigEndian.PutUint16(buf, port) + return usermem.ByteOrder.Uint16(buf) +} + +func htons(port uint16) uint16 { + buf := make([]byte, 2) + usermem.ByteOrder.PutUint16(buf, port) + return binary.BigEndian.Uint16(buf) +} diff --git a/pkg/sentry/socket/netfilter/tcp_matcher.go b/pkg/sentry/socket/netfilter/tcp_matcher.go index 0bfd6c1f4..844acfede 100644 --- a/pkg/sentry/socket/netfilter/tcp_matcher.go +++ b/pkg/sentry/socket/netfilter/tcp_matcher.go @@ -97,17 +97,33 @@ func (*TCPMatcher) Name() string { // Match implements Matcher.Match. func (tm *TCPMatcher) Match(hook stack.Hook, pkt *stack.PacketBuffer, interfaceName string) (bool, bool) { - netHeader := header.IPv4(pkt.NetworkHeader().View()) + // TODO(gvisor.dev/issue/170): Proto checks should ultimately be moved + // into the stack.Check codepath as matchers are added. + switch pkt.NetworkProtocolNumber { + case header.IPv4ProtocolNumber: + netHeader := header.IPv4(pkt.NetworkHeader().View()) + if netHeader.TransportProtocol() != header.TCPProtocolNumber { + return false, false + } - if netHeader.TransportProtocol() != header.TCPProtocolNumber { - return false, false - } + // We don't match fragments. + if frag := netHeader.FragmentOffset(); frag != 0 { + if frag == 1 { + return false, true + } + return false, false + } - // We dont't match fragments. - if frag := netHeader.FragmentOffset(); frag != 0 { - if frag == 1 { - return false, true + case header.IPv6ProtocolNumber: + // As in Linux, we do not perform an IPv6 fragment check. See + // xt_action_param.fragoff in + // include/linux/netfilter/x_tables.h. + if header.IPv6(pkt.NetworkHeader().View()).TransportProtocol() != header.TCPProtocolNumber { + return false, false } + + default: + // We don't know the network protocol. return false, false } diff --git a/pkg/sentry/socket/netfilter/udp_matcher.go b/pkg/sentry/socket/netfilter/udp_matcher.go index 7ed05461d..63201201c 100644 --- a/pkg/sentry/socket/netfilter/udp_matcher.go +++ b/pkg/sentry/socket/netfilter/udp_matcher.go @@ -94,19 +94,33 @@ func (*UDPMatcher) Name() string { // Match implements Matcher.Match. func (um *UDPMatcher) Match(hook stack.Hook, pkt *stack.PacketBuffer, interfaceName string) (bool, bool) { - netHeader := header.IPv4(pkt.NetworkHeader().View()) - // TODO(gvisor.dev/issue/170): Proto checks should ultimately be moved // into the stack.Check codepath as matchers are added. - if netHeader.TransportProtocol() != header.UDPProtocolNumber { - return false, false - } + switch pkt.NetworkProtocolNumber { + case header.IPv4ProtocolNumber: + netHeader := header.IPv4(pkt.NetworkHeader().View()) + if netHeader.TransportProtocol() != header.UDPProtocolNumber { + return false, false + } - // We dont't match fragments. - if frag := netHeader.FragmentOffset(); frag != 0 { - if frag == 1 { - return false, true + // We don't match fragments. + if frag := netHeader.FragmentOffset(); frag != 0 { + if frag == 1 { + return false, true + } + return false, false } + + case header.IPv6ProtocolNumber: + // As in Linux, we do not perform an IPv6 fragment check. See + // xt_action_param.fragoff in + // include/linux/netfilter/x_tables.h. + if header.IPv6(pkt.NetworkHeader().View()).TransportProtocol() != header.UDPProtocolNumber { + return false, false + } + + default: + // We don't know the network protocol. return false, false } diff --git a/pkg/sentry/socket/netlink/BUILD b/pkg/sentry/socket/netlink/BUILD index 0546801bf..1f926aa91 100644 --- a/pkg/sentry/socket/netlink/BUILD +++ b/pkg/sentry/socket/netlink/BUILD @@ -16,6 +16,8 @@ go_library( "//pkg/abi/linux", "//pkg/binary", "//pkg/context", + "//pkg/marshal", + "//pkg/marshal/primitive", "//pkg/sentry/arch", "//pkg/sentry/device", "//pkg/sentry/fs", @@ -36,8 +38,6 @@ go_library( "//pkg/tcpip", "//pkg/usermem", "//pkg/waiter", - "//tools/go_marshal/marshal", - "//tools/go_marshal/primitive", ], ) diff --git a/pkg/sentry/socket/netlink/provider_vfs2.go b/pkg/sentry/socket/netlink/provider_vfs2.go index bb205be0d..e8930f031 100644 --- a/pkg/sentry/socket/netlink/provider_vfs2.go +++ b/pkg/sentry/socket/netlink/provider_vfs2.go @@ -52,6 +52,7 @@ func (*socketProviderVFS2) Socket(t *kernel.Task, stype linux.SockType, protocol vfsfd := &s.vfsfd mnt := t.Kernel().SocketMount() d := sockfs.NewDentry(t.Credentials(), mnt) + defer d.DecRef(t) if err := vfsfd.Init(s, linux.O_RDWR, mnt, d, &vfs.FileDescriptionOptions{ DenyPRead: true, DenyPWrite: true, diff --git a/pkg/sentry/socket/netlink/socket.go b/pkg/sentry/socket/netlink/socket.go index 68a9b9a96..5ddcd4be5 100644 --- a/pkg/sentry/socket/netlink/socket.go +++ b/pkg/sentry/socket/netlink/socket.go @@ -21,6 +21,8 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/binary" "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/marshal" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/device" "gvisor.dev/gvisor/pkg/sentry/fs" @@ -38,8 +40,6 @@ import ( "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/usermem" "gvisor.dev/gvisor/pkg/waiter" - "gvisor.dev/gvisor/tools/go_marshal/marshal" - "gvisor.dev/gvisor/tools/go_marshal/primitive" ) const sizeOfInt32 int = 4 diff --git a/pkg/sentry/socket/netlink/socket_vfs2.go b/pkg/sentry/socket/netlink/socket_vfs2.go index a38d25da9..c83b23242 100644 --- a/pkg/sentry/socket/netlink/socket_vfs2.go +++ b/pkg/sentry/socket/netlink/socket_vfs2.go @@ -82,6 +82,13 @@ func NewVFS2(t *kernel.Task, skType linux.SockType, protocol Protocol) (*SocketV return fd, nil } +// Release implements vfs.FileDescriptionImpl.Release. +func (s *SocketVFS2) Release(ctx context.Context) { + t := kernel.TaskFromContext(ctx) + t.Kernel().DeleteSocketVFS2(&s.vfsfd) + s.socketOpsCommon.Release(ctx) +} + // Readiness implements waiter.Waitable.Readiness. func (s *SocketVFS2) Readiness(mask waiter.EventMask) waiter.EventMask { return s.socketOpsCommon.Readiness(mask) diff --git a/pkg/sentry/socket/netstack/BUILD b/pkg/sentry/socket/netstack/BUILD index 1fb777a6c..fae3b6783 100644 --- a/pkg/sentry/socket/netstack/BUILD +++ b/pkg/sentry/socket/netstack/BUILD @@ -22,6 +22,8 @@ go_library( "//pkg/binary", "//pkg/context", "//pkg/log", + "//pkg/marshal", + "//pkg/marshal/primitive", "//pkg/metric", "//pkg/safemem", "//pkg/sentry/arch", @@ -51,8 +53,6 @@ go_library( "//pkg/tcpip/transport/udp", "//pkg/usermem", "//pkg/waiter", - "//tools/go_marshal/marshal", - "//tools/go_marshal/primitive", "@org_golang_x_sys//unix:go_default_library", ], ) diff --git a/pkg/sentry/socket/netstack/netstack.go b/pkg/sentry/socket/netstack/netstack.go index 0bf21f7d8..87e30d742 100644 --- a/pkg/sentry/socket/netstack/netstack.go +++ b/pkg/sentry/socket/netstack/netstack.go @@ -40,6 +40,8 @@ import ( "gvisor.dev/gvisor/pkg/binary" "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/log" + "gvisor.dev/gvisor/pkg/marshal" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/metric" "gvisor.dev/gvisor/pkg/safemem" "gvisor.dev/gvisor/pkg/sentry/arch" @@ -62,8 +64,6 @@ import ( "gvisor.dev/gvisor/pkg/tcpip/transport/udp" "gvisor.dev/gvisor/pkg/usermem" "gvisor.dev/gvisor/pkg/waiter" - "gvisor.dev/gvisor/tools/go_marshal/marshal" - "gvisor.dev/gvisor/tools/go_marshal/primitive" ) func mustCreateMetric(name, description string) *tcpip.StatCounter { @@ -158,6 +158,9 @@ var Metrics = tcpip.Stats{ OutgoingPacketErrors: mustCreateMetric("/netstack/ip/outgoing_packet_errors", "Total number of IP packets which failed to write to a link-layer endpoint."), MalformedPacketsReceived: mustCreateMetric("/netstack/ip/malformed_packets_received", "Total number of IP packets which failed IP header validation checks."), MalformedFragmentsReceived: mustCreateMetric("/netstack/ip/malformed_fragments_received", "Total number of IP fragments which failed IP fragment validation checks."), + IPTablesPreroutingDropped: mustCreateMetric("/netstack/ip/iptables/prerouting_dropped", "Total number of IP packets dropped in the Prerouting chain."), + IPTablesInputDropped: mustCreateMetric("/netstack/ip/iptables/input_dropped", "Total number of IP packets dropped in the Input chain."), + IPTablesOutputDropped: mustCreateMetric("/netstack/ip/iptables/output_dropped", "Total number of IP packets dropped in the Output chain."), }, TCP: tcpip.TCPStats{ ActiveConnectionOpenings: mustCreateMetric("/netstack/tcp/active_connection_openings", "Number of connections opened successfully via Connect."), @@ -195,7 +198,6 @@ var Metrics = tcpip.Stats{ PacketsSent: mustCreateMetric("/netstack/udp/packets_sent", "Number of UDP datagrams sent."), PacketSendErrors: mustCreateMetric("/netstack/udp/packet_send_errors", "Number of UDP datagrams failed to be sent."), ChecksumErrors: mustCreateMetric("/netstack/udp/checksum_errors", "Number of UDP datagrams dropped due to bad checksums."), - InvalidSourceAddress: mustCreateMetric("/netstack/udp/invalid_source", "Number of UDP datagrams dropped due to invalid source address."), }, } @@ -857,7 +859,7 @@ func (s *socketOpsCommon) Listen(t *kernel.Task, backlog int) *syserr.Error { // blockingAccept implements a blocking version of accept(2), that is, if no // connections are ready to be accept, it will block until one becomes ready. -func (s *socketOpsCommon) blockingAccept(t *kernel.Task) (tcpip.Endpoint, *waiter.Queue, *syserr.Error) { +func (s *socketOpsCommon) blockingAccept(t *kernel.Task, peerAddr *tcpip.FullAddress) (tcpip.Endpoint, *waiter.Queue, *syserr.Error) { // Register for notifications. e, ch := waiter.NewChannelEntry(nil) s.EventRegister(&e, waiter.EventIn) @@ -866,7 +868,7 @@ func (s *socketOpsCommon) blockingAccept(t *kernel.Task) (tcpip.Endpoint, *waite // Try to accept the connection again; if it fails, then wait until we // get a notification. for { - if ep, wq, err := s.Endpoint.Accept(); err != tcpip.ErrWouldBlock { + if ep, wq, err := s.Endpoint.Accept(peerAddr); err != tcpip.ErrWouldBlock { return ep, wq, syserr.TranslateNetstackError(err) } @@ -879,15 +881,18 @@ func (s *socketOpsCommon) blockingAccept(t *kernel.Task) (tcpip.Endpoint, *waite // Accept implements the linux syscall accept(2) for sockets backed by // tcpip.Endpoint. func (s *SocketOperations) Accept(t *kernel.Task, peerRequested bool, flags int, blocking bool) (int32, linux.SockAddr, uint32, *syserr.Error) { - // Issue the accept request to get the new endpoint. - ep, wq, terr := s.Endpoint.Accept() + var peerAddr *tcpip.FullAddress + if peerRequested { + peerAddr = &tcpip.FullAddress{} + } + ep, wq, terr := s.Endpoint.Accept(peerAddr) if terr != nil { if terr != tcpip.ErrWouldBlock || !blocking { return 0, nil, 0, syserr.TranslateNetstackError(terr) } var err *syserr.Error - ep, wq, err = s.blockingAccept(t) + ep, wq, err = s.blockingAccept(t, peerAddr) if err != nil { return 0, nil, 0, err } @@ -907,13 +912,8 @@ func (s *SocketOperations) Accept(t *kernel.Task, peerRequested bool, flags int, var addr linux.SockAddr var addrLen uint32 - if peerRequested { - // Get address of the peer and write it to peer slice. - var err *syserr.Error - addr, addrLen, err = ns.FileOperations.(*SocketOperations).GetPeerName(t) - if err != nil { - return 0, nil, 0, err - } + if peerAddr != nil { + addr, addrLen = ConvertAddress(s.family, *peerAddr) } fd, e := t.NewFDFrom(0, ns, kernel.FDFlags{ @@ -1187,7 +1187,7 @@ func getSockOptSocket(t *kernel.Task, s socket.SocketOps, ep commonEndpoint, fam var v tcpip.LingerOption var linger linux.Linger if err := ep.GetSockOpt(&v); err != nil { - return &linger, nil + return nil, syserr.TranslateNetstackError(err) } if v.Enabled { @@ -1512,8 +1512,17 @@ func getSockOptIPv6(t *kernel.Task, s socket.SocketOps, ep commonEndpoint, name return &vP, nil case linux.IP6T_ORIGINAL_DST: - // TODO(gvisor.dev/issue/170): ip6tables. - return nil, syserr.ErrInvalidArgument + if outLen < int(binary.Size(linux.SockAddrInet6{})) { + return nil, syserr.ErrInvalidArgument + } + + var v tcpip.OriginalDestinationOption + if err := ep.GetSockOpt(&v); err != nil { + return nil, syserr.TranslateNetstackError(err) + } + + a, _ := ConvertAddress(linux.AF_INET6, tcpip.FullAddress(v)) + return a.(*linux.SockAddrInet6), nil case linux.IP6T_SO_GET_INFO: if outLen < linux.SizeOfIPTGetinfo { @@ -1555,6 +1564,26 @@ func getSockOptIPv6(t *kernel.Task, s socket.SocketOps, ep commonEndpoint, name } return &entries, nil + case linux.IP6T_SO_GET_REVISION_TARGET: + if outLen < linux.SizeOfXTGetRevision { + return nil, syserr.ErrInvalidArgument + } + + // Only valid for raw IPv6 sockets. + if family, skType, _ := s.Type(); family != linux.AF_INET6 || skType != linux.SOCK_RAW { + return nil, syserr.ErrProtocolNotAvailable + } + + stack := inet.StackFromContext(t) + if stack == nil { + return nil, syserr.ErrNoDevice + } + ret, err := netfilter.TargetRevision(t, outPtr, header.IPv6ProtocolNumber) + if err != nil { + return nil, err + } + return &ret, nil + default: emitUnimplementedEventIPv6(t, name) } @@ -1718,6 +1747,26 @@ func getSockOptIP(t *kernel.Task, s socket.SocketOps, ep commonEndpoint, name in } return &entries, nil + case linux.IPT_SO_GET_REVISION_TARGET: + if outLen < linux.SizeOfXTGetRevision { + return nil, syserr.ErrInvalidArgument + } + + // Only valid for raw IPv4 sockets. + if family, skType, _ := s.Type(); family != linux.AF_INET || skType != linux.SOCK_RAW { + return nil, syserr.ErrProtocolNotAvailable + } + + stack := inet.StackFromContext(t) + if stack == nil { + return nil, syserr.ErrNoDevice + } + ret, err := netfilter.TargetRevision(t, outPtr, header.IPv4ProtocolNumber) + if err != nil { + return nil, err + } + return &ret, nil + default: emitUnimplementedEventIP(t, name) } @@ -1770,10 +1819,16 @@ func SetSockOpt(t *kernel.Task, s socket.SocketOps, ep commonEndpoint, level int case linux.SOL_IP: return setSockOptIP(t, s, ep, name, optVal) + case linux.SOL_PACKET: + // gVisor doesn't support any SOL_PACKET options just return not + // supported. Returning nil here will result in tcpdump thinking AF_PACKET + // features are supported and proceed to use them and break. + t.Kernel().EmitUnimplementedEvent(t) + return syserr.ErrProtocolNotAvailable + case linux.SOL_UDP, linux.SOL_ICMPV6, - linux.SOL_RAW, - linux.SOL_PACKET: + linux.SOL_RAW: t.Kernel().EmitUnimplementedEvent(t) } diff --git a/pkg/sentry/socket/netstack/netstack_vfs2.go b/pkg/sentry/socket/netstack/netstack_vfs2.go index 1f7d17f5f..4c6791fff 100644 --- a/pkg/sentry/socket/netstack/netstack_vfs2.go +++ b/pkg/sentry/socket/netstack/netstack_vfs2.go @@ -18,6 +18,8 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/amutex" "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/marshal" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/arch" fslock "gvisor.dev/gvisor/pkg/sentry/fs/lock" "gvisor.dev/gvisor/pkg/sentry/fsimpl/sockfs" @@ -29,8 +31,6 @@ import ( "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/usermem" "gvisor.dev/gvisor/pkg/waiter" - "gvisor.dev/gvisor/tools/go_marshal/marshal" - "gvisor.dev/gvisor/tools/go_marshal/primitive" ) // SocketVFS2 encapsulates all the state needed to represent a network stack @@ -79,6 +79,13 @@ func NewVFS2(t *kernel.Task, family int, skType linux.SockType, protocol int, qu return vfsfd, nil } +// Release implements vfs.FileDescriptionImpl.Release. +func (s *SocketVFS2) Release(ctx context.Context) { + t := kernel.TaskFromContext(ctx) + t.Kernel().DeleteSocketVFS2(&s.vfsfd) + s.socketOpsCommon.Release(ctx) +} + // Readiness implements waiter.Waitable.Readiness. func (s *SocketVFS2) Readiness(mask waiter.EventMask) waiter.EventMask { return s.socketOpsCommon.Readiness(mask) @@ -151,14 +158,18 @@ func (s *SocketVFS2) Write(ctx context.Context, src usermem.IOSequence, opts vfs // tcpip.Endpoint. func (s *SocketVFS2) Accept(t *kernel.Task, peerRequested bool, flags int, blocking bool) (int32, linux.SockAddr, uint32, *syserr.Error) { // Issue the accept request to get the new endpoint. - ep, wq, terr := s.Endpoint.Accept() + var peerAddr *tcpip.FullAddress + if peerRequested { + peerAddr = &tcpip.FullAddress{} + } + ep, wq, terr := s.Endpoint.Accept(peerAddr) if terr != nil { if terr != tcpip.ErrWouldBlock || !blocking { return 0, nil, 0, syserr.TranslateNetstackError(terr) } var err *syserr.Error - ep, wq, err = s.blockingAccept(t) + ep, wq, err = s.blockingAccept(t, peerAddr) if err != nil { return 0, nil, 0, err } @@ -176,13 +187,9 @@ func (s *SocketVFS2) Accept(t *kernel.Task, peerRequested bool, flags int, block var addr linux.SockAddr var addrLen uint32 - if peerRequested { + if peerAddr != nil { // Get address of the peer and write it to peer slice. - var err *syserr.Error - addr, addrLen, err = ns.Impl().(*SocketVFS2).GetPeerName(t) - if err != nil { - return 0, nil, 0, err - } + addr, addrLen = ConvertAddress(s.family, *peerAddr) } fd, e := t.NewFDFromVFS2(0, ns, kernel.FDFlags{ diff --git a/pkg/sentry/socket/netstack/stack.go b/pkg/sentry/socket/netstack/stack.go index f0fe18684..1028d2a6e 100644 --- a/pkg/sentry/socket/netstack/stack.go +++ b/pkg/sentry/socket/netstack/stack.go @@ -155,7 +155,7 @@ func (s *Stack) AddInterfaceAddr(idx int32, addr inet.InterfaceAddr) error { // TCPReceiveBufferSize implements inet.Stack.TCPReceiveBufferSize. func (s *Stack) TCPReceiveBufferSize() (inet.TCPBufferSize, error) { - var rs tcp.ReceiveBufferSizeOption + var rs tcpip.TCPReceiveBufferSizeRangeOption err := s.Stack.TransportProtocolOption(tcp.ProtocolNumber, &rs) return inet.TCPBufferSize{ Min: rs.Min, @@ -166,17 +166,17 @@ func (s *Stack) TCPReceiveBufferSize() (inet.TCPBufferSize, error) { // SetTCPReceiveBufferSize implements inet.Stack.SetTCPReceiveBufferSize. func (s *Stack) SetTCPReceiveBufferSize(size inet.TCPBufferSize) error { - rs := tcp.ReceiveBufferSizeOption{ + rs := tcpip.TCPReceiveBufferSizeRangeOption{ Min: size.Min, Default: size.Default, Max: size.Max, } - return syserr.TranslateNetstackError(s.Stack.SetTransportProtocolOption(tcp.ProtocolNumber, rs)).ToError() + return syserr.TranslateNetstackError(s.Stack.SetTransportProtocolOption(tcp.ProtocolNumber, &rs)).ToError() } // TCPSendBufferSize implements inet.Stack.TCPSendBufferSize. func (s *Stack) TCPSendBufferSize() (inet.TCPBufferSize, error) { - var ss tcp.SendBufferSizeOption + var ss tcpip.TCPSendBufferSizeRangeOption err := s.Stack.TransportProtocolOption(tcp.ProtocolNumber, &ss) return inet.TCPBufferSize{ Min: ss.Min, @@ -187,29 +187,30 @@ func (s *Stack) TCPSendBufferSize() (inet.TCPBufferSize, error) { // SetTCPSendBufferSize implements inet.Stack.SetTCPSendBufferSize. func (s *Stack) SetTCPSendBufferSize(size inet.TCPBufferSize) error { - ss := tcp.SendBufferSizeOption{ + ss := tcpip.TCPSendBufferSizeRangeOption{ Min: size.Min, Default: size.Default, Max: size.Max, } - return syserr.TranslateNetstackError(s.Stack.SetTransportProtocolOption(tcp.ProtocolNumber, ss)).ToError() + return syserr.TranslateNetstackError(s.Stack.SetTransportProtocolOption(tcp.ProtocolNumber, &ss)).ToError() } // TCPSACKEnabled implements inet.Stack.TCPSACKEnabled. func (s *Stack) TCPSACKEnabled() (bool, error) { - var sack tcp.SACKEnabled + var sack tcpip.TCPSACKEnabled err := s.Stack.TransportProtocolOption(tcp.ProtocolNumber, &sack) return bool(sack), syserr.TranslateNetstackError(err).ToError() } // SetTCPSACKEnabled implements inet.Stack.SetTCPSACKEnabled. func (s *Stack) SetTCPSACKEnabled(enabled bool) error { - return syserr.TranslateNetstackError(s.Stack.SetTransportProtocolOption(tcp.ProtocolNumber, tcp.SACKEnabled(enabled))).ToError() + opt := tcpip.TCPSACKEnabled(enabled) + return syserr.TranslateNetstackError(s.Stack.SetTransportProtocolOption(tcp.ProtocolNumber, &opt)).ToError() } // TCPRecovery implements inet.Stack.TCPRecovery. func (s *Stack) TCPRecovery() (inet.TCPLossRecovery, error) { - var recovery tcp.Recovery + var recovery tcpip.TCPRecovery if err := s.Stack.TransportProtocolOption(tcp.ProtocolNumber, &recovery); err != nil { return 0, syserr.TranslateNetstackError(err).ToError() } @@ -218,7 +219,8 @@ func (s *Stack) TCPRecovery() (inet.TCPLossRecovery, error) { // SetTCPRecovery implements inet.Stack.SetTCPRecovery. func (s *Stack) SetTCPRecovery(recovery inet.TCPLossRecovery) error { - return syserr.TranslateNetstackError(s.Stack.SetTransportProtocolOption(tcp.ProtocolNumber, tcp.Recovery(recovery))).ToError() + opt := tcpip.TCPRecovery(recovery) + return syserr.TranslateNetstackError(s.Stack.SetTransportProtocolOption(tcp.ProtocolNumber, &opt)).ToError() } // Statistics implements inet.Stack.Statistics. @@ -410,3 +412,24 @@ func (s *Stack) CleanupEndpoints() []stack.TransportEndpoint { func (s *Stack) RestoreCleanupEndpoints(es []stack.TransportEndpoint) { s.Stack.RestoreCleanupEndpoints(es) } + +// Forwarding implements inet.Stack.Forwarding. +func (s *Stack) Forwarding(protocol tcpip.NetworkProtocolNumber) bool { + switch protocol { + case ipv4.ProtocolNumber, ipv6.ProtocolNumber: + return s.Stack.Forwarding(protocol) + default: + panic(fmt.Sprintf("Forwarding(%v) failed: unsupported protocol", protocol)) + } +} + +// SetForwarding implements inet.Stack.SetForwarding. +func (s *Stack) SetForwarding(protocol tcpip.NetworkProtocolNumber, enable bool) error { + switch protocol { + case ipv4.ProtocolNumber, ipv6.ProtocolNumber: + s.Stack.SetForwarding(protocol, enable) + default: + panic(fmt.Sprintf("SetForwarding(%v) failed: unsupported protocol", protocol)) + } + return nil +} diff --git a/pkg/sentry/socket/socket.go b/pkg/sentry/socket/socket.go index 04b259d27..fd31479e5 100644 --- a/pkg/sentry/socket/socket.go +++ b/pkg/sentry/socket/socket.go @@ -25,6 +25,7 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/binary" "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/marshal" "gvisor.dev/gvisor/pkg/sentry/device" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/fs/fsutil" @@ -35,7 +36,6 @@ import ( "gvisor.dev/gvisor/pkg/syserr" "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/usermem" - "gvisor.dev/gvisor/tools/go_marshal/marshal" ) // ControlMessages represents the union of unix control messages and tcpip diff --git a/pkg/sentry/socket/unix/BUILD b/pkg/sentry/socket/unix/BUILD index cb953e4dc..cc7408698 100644 --- a/pkg/sentry/socket/unix/BUILD +++ b/pkg/sentry/socket/unix/BUILD @@ -7,10 +7,21 @@ go_template_instance( name = "socket_refs", out = "socket_refs.go", package = "unix", - prefix = "socketOpsCommon", + prefix = "socketOperations", template = "//pkg/refs_vfs2:refs_template", types = { - "T": "socketOpsCommon", + "T": "SocketOperations", + }, +) + +go_template_instance( + name = "socket_vfs2_refs", + out = "socket_vfs2_refs.go", + package = "unix", + prefix = "socketVFS2", + template = "//pkg/refs_vfs2:refs_template", + types = { + "T": "SocketVFS2", }, ) @@ -20,6 +31,7 @@ go_library( "device.go", "io.go", "socket_refs.go", + "socket_vfs2_refs.go", "unix.go", "unix_vfs2.go", ], @@ -29,6 +41,7 @@ go_library( "//pkg/context", "//pkg/fspath", "//pkg/log", + "//pkg/marshal", "//pkg/refs", "//pkg/safemem", "//pkg/sentry/arch", @@ -49,6 +62,5 @@ go_library( "//pkg/tcpip", "//pkg/usermem", "//pkg/waiter", - "//tools/go_marshal/marshal", ], ) diff --git a/pkg/sentry/socket/unix/transport/connectioned.go b/pkg/sentry/socket/unix/transport/connectioned.go index e3a75b519..aa4f3c04d 100644 --- a/pkg/sentry/socket/unix/transport/connectioned.go +++ b/pkg/sentry/socket/unix/transport/connectioned.go @@ -391,7 +391,7 @@ func (e *connectionedEndpoint) Listen(backlog int) *syserr.Error { } // Accept accepts a new connection. -func (e *connectionedEndpoint) Accept() (Endpoint, *syserr.Error) { +func (e *connectionedEndpoint) Accept(peerAddr *tcpip.FullAddress) (Endpoint, *syserr.Error) { e.Lock() defer e.Unlock() @@ -401,6 +401,18 @@ func (e *connectionedEndpoint) Accept() (Endpoint, *syserr.Error) { select { case ne := <-e.acceptedChan: + if peerAddr != nil { + ne.Lock() + c := ne.connected + ne.Unlock() + if c != nil { + addr, err := c.GetLocalAddress() + if err != nil { + return nil, syserr.TranslateNetstackError(err) + } + *peerAddr = addr + } + } return ne, nil default: diff --git a/pkg/sentry/socket/unix/transport/connectionless.go b/pkg/sentry/socket/unix/transport/connectionless.go index 4751b2fd8..f8aacca13 100644 --- a/pkg/sentry/socket/unix/transport/connectionless.go +++ b/pkg/sentry/socket/unix/transport/connectionless.go @@ -144,12 +144,12 @@ func (e *connectionlessEndpoint) Connect(ctx context.Context, server BoundEndpoi } // Listen starts listening on the connection. -func (e *connectionlessEndpoint) Listen(int) *syserr.Error { +func (*connectionlessEndpoint) Listen(int) *syserr.Error { return syserr.ErrNotSupported } // Accept accepts a new connection. -func (e *connectionlessEndpoint) Accept() (Endpoint, *syserr.Error) { +func (*connectionlessEndpoint) Accept(*tcpip.FullAddress) (Endpoint, *syserr.Error) { return nil, syserr.ErrNotSupported } diff --git a/pkg/sentry/socket/unix/transport/unix.go b/pkg/sentry/socket/unix/transport/unix.go index cc9d650fb..d6fc03520 100644 --- a/pkg/sentry/socket/unix/transport/unix.go +++ b/pkg/sentry/socket/unix/transport/unix.go @@ -151,7 +151,10 @@ type Endpoint interface { // block if no new connections are available. // // The returned Queue is the wait queue for the newly created endpoint. - Accept() (Endpoint, *syserr.Error) + // + // peerAddr if not nil will be populated with the address of the connected + // peer on a successful accept. + Accept(peerAddr *tcpip.FullAddress) (Endpoint, *syserr.Error) // Bind binds the endpoint to a specific local address and port. // Specifying a NIC is optional. @@ -743,6 +746,9 @@ type baseEndpoint struct { // path is not empty if the endpoint has been bound, // or may be used if the endpoint is connected. path string + + // linger is used for SO_LINGER socket option. + linger tcpip.LingerOption } // EventRegister implements waiter.Waitable.EventRegister. @@ -838,8 +844,14 @@ func (e *baseEndpoint) SendMsg(ctx context.Context, data [][]byte, c ControlMess return n, err } -// SetSockOpt sets a socket option. Currently not supported. -func (e *baseEndpoint) SetSockOpt(tcpip.SettableSocketOption) *tcpip.Error { +// SetSockOpt sets a socket option. +func (e *baseEndpoint) SetSockOpt(opt tcpip.SettableSocketOption) *tcpip.Error { + switch v := opt.(type) { + case *tcpip.LingerOption: + e.Lock() + e.linger = *v + e.Unlock() + } return nil } @@ -942,8 +954,11 @@ func (e *baseEndpoint) GetSockOptInt(opt tcpip.SockOptInt) (int, *tcpip.Error) { // GetSockOpt implements tcpip.Endpoint.GetSockOpt. func (e *baseEndpoint) GetSockOpt(opt tcpip.GettableSocketOption) *tcpip.Error { - switch opt.(type) { + switch o := opt.(type) { case *tcpip.LingerOption: + e.Lock() + *o = e.linger + e.Unlock() return nil default: diff --git a/pkg/sentry/socket/unix/unix.go b/pkg/sentry/socket/unix/unix.go index 0a7a26495..f80011ce4 100644 --- a/pkg/sentry/socket/unix/unix.go +++ b/pkg/sentry/socket/unix/unix.go @@ -24,6 +24,7 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/fspath" + "gvisor.dev/gvisor/pkg/marshal" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/fs/fsutil" @@ -39,7 +40,6 @@ import ( "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/usermem" "gvisor.dev/gvisor/pkg/waiter" - "gvisor.dev/gvisor/tools/go_marshal/marshal" ) // SocketOperations is a Unix socket. It is similar to a netstack socket, @@ -55,6 +55,7 @@ type SocketOperations struct { fsutil.FileNoopFlush `state:"nosave"` fsutil.FileUseInodeUnstableAttr `state:"nosave"` + socketOperationsRefs socketOpsCommon } @@ -84,11 +85,27 @@ func NewWithDirent(ctx context.Context, d *fs.Dirent, ep transport.Endpoint, sty return fs.NewFile(ctx, d, flags, &s) } +// DecRef implements RefCounter.DecRef. +func (s *SocketOperations) DecRef(ctx context.Context) { + s.socketOperationsRefs.DecRef(func() { + s.ep.Close(ctx) + if s.abstractNamespace != nil { + s.abstractNamespace.Remove(s.abstractName, s) + } + }) +} + +// Release implemements fs.FileOperations.Release. +func (s *SocketOperations) Release(ctx context.Context) { + // Release only decrements a reference on s because s may be referenced in + // the abstract socket namespace. + s.DecRef(ctx) +} + // socketOpsCommon contains the socket operations common to VFS1 and VFS2. // // +stateify savable type socketOpsCommon struct { - socketOpsCommonRefs socket.SendReceiveTimeout ep transport.Endpoint @@ -101,23 +118,6 @@ type socketOpsCommon struct { abstractNamespace *kernel.AbstractSocketNamespace } -// DecRef implements RefCounter.DecRef. -func (s *socketOpsCommon) DecRef(ctx context.Context) { - s.socketOpsCommonRefs.DecRef(func() { - s.ep.Close(ctx) - if s.abstractNamespace != nil { - s.abstractNamespace.Remove(s.abstractName, s) - } - }) -} - -// Release implemements fs.FileOperations.Release. -func (s *socketOpsCommon) Release(ctx context.Context) { - // Release only decrements a reference on s because s may be referenced in - // the abstract socket namespace. - s.DecRef(ctx) -} - func (s *socketOpsCommon) isPacket() bool { switch s.stype { case linux.SOCK_DGRAM, linux.SOCK_SEQPACKET: @@ -205,7 +205,7 @@ func (s *socketOpsCommon) Listen(t *kernel.Task, backlog int) *syserr.Error { // blockingAccept implements a blocking version of accept(2), that is, if no // connections are ready to be accept, it will block until one becomes ready. -func (s *SocketOperations) blockingAccept(t *kernel.Task) (transport.Endpoint, *syserr.Error) { +func (s *SocketOperations) blockingAccept(t *kernel.Task, peerAddr *tcpip.FullAddress) (transport.Endpoint, *syserr.Error) { // Register for notifications. e, ch := waiter.NewChannelEntry(nil) s.EventRegister(&e, waiter.EventIn) @@ -214,7 +214,7 @@ func (s *SocketOperations) blockingAccept(t *kernel.Task) (transport.Endpoint, * // Try to accept the connection; if it fails, then wait until we get a // notification. for { - if ep, err := s.ep.Accept(); err != syserr.ErrWouldBlock { + if ep, err := s.ep.Accept(peerAddr); err != syserr.ErrWouldBlock { return ep, err } @@ -227,15 +227,18 @@ func (s *SocketOperations) blockingAccept(t *kernel.Task) (transport.Endpoint, * // Accept implements the linux syscall accept(2) for sockets backed by // a transport.Endpoint. func (s *SocketOperations) Accept(t *kernel.Task, peerRequested bool, flags int, blocking bool) (int32, linux.SockAddr, uint32, *syserr.Error) { - // Issue the accept request to get the new endpoint. - ep, err := s.ep.Accept() + var peerAddr *tcpip.FullAddress + if peerRequested { + peerAddr = &tcpip.FullAddress{} + } + ep, err := s.ep.Accept(peerAddr) if err != nil { if err != syserr.ErrWouldBlock || !blocking { return 0, nil, 0, err } var err *syserr.Error - ep, err = s.blockingAccept(t) + ep, err = s.blockingAccept(t, peerAddr) if err != nil { return 0, nil, 0, err } @@ -252,13 +255,8 @@ func (s *SocketOperations) Accept(t *kernel.Task, peerRequested bool, flags int, var addr linux.SockAddr var addrLen uint32 - if peerRequested { - // Get address of the peer. - var err *syserr.Error - addr, addrLen, err = ns.FileOperations.(*SocketOperations).GetPeerName(t) - if err != nil { - return 0, nil, 0, err - } + if peerAddr != nil { + addr, addrLen = netstack.ConvertAddress(linux.AF_UNIX, *peerAddr) } fd, e := t.NewFDFrom(0, ns, kernel.FDFlags{ diff --git a/pkg/sentry/socket/unix/unix_vfs2.go b/pkg/sentry/socket/unix/unix_vfs2.go index 65a285b8f..3345124cc 100644 --- a/pkg/sentry/socket/unix/unix_vfs2.go +++ b/pkg/sentry/socket/unix/unix_vfs2.go @@ -18,6 +18,7 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/fspath" + "gvisor.dev/gvisor/pkg/marshal" "gvisor.dev/gvisor/pkg/sentry/arch" fslock "gvisor.dev/gvisor/pkg/sentry/fs/lock" "gvisor.dev/gvisor/pkg/sentry/fsimpl/sockfs" @@ -32,17 +33,19 @@ import ( "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/usermem" "gvisor.dev/gvisor/pkg/waiter" - "gvisor.dev/gvisor/tools/go_marshal/marshal" ) // SocketVFS2 implements socket.SocketVFS2 (and by extension, // vfs.FileDescriptionImpl) for Unix sockets. +// +// +stateify savable type SocketVFS2 struct { vfsfd vfs.FileDescription vfs.FileDescriptionDefaultImpl vfs.DentryMetadataFileDescriptionImpl vfs.LockFD + socketVFS2Refs socketOpsCommon } @@ -53,6 +56,7 @@ var _ = socket.SocketVFS2(&SocketVFS2{}) func NewSockfsFile(t *kernel.Task, ep transport.Endpoint, stype linux.SockType) (*vfs.FileDescription, *syserr.Error) { mnt := t.Kernel().SocketMount() d := sockfs.NewDentry(t.Credentials(), mnt) + defer d.DecRef(t) fd, err := NewFileDescription(ep, stype, linux.O_RDWR, mnt, d, &vfs.FileLocks{}) if err != nil { @@ -88,6 +92,25 @@ func NewFileDescription(ep transport.Endpoint, stype linux.SockType, flags uint3 return vfsfd, nil } +// DecRef implements RefCounter.DecRef. +func (s *SocketVFS2) DecRef(ctx context.Context) { + s.socketVFS2Refs.DecRef(func() { + t := kernel.TaskFromContext(ctx) + t.Kernel().DeleteSocketVFS2(&s.vfsfd) + s.ep.Close(ctx) + if s.abstractNamespace != nil { + s.abstractNamespace.Remove(s.abstractName, s) + } + }) +} + +// Release implements vfs.FileDescriptionImpl.Release. +func (s *SocketVFS2) Release(ctx context.Context) { + // Release only decrements a reference on s because s may be referenced in + // the abstract socket namespace. + s.DecRef(ctx) +} + // GetSockOpt implements the linux syscall getsockopt(2) for sockets backed by // a transport.Endpoint. func (s *SocketVFS2) GetSockOpt(t *kernel.Task, level, name int, outPtr usermem.Addr, outLen int) (marshal.Marshallable, *syserr.Error) { @@ -96,7 +119,7 @@ func (s *SocketVFS2) GetSockOpt(t *kernel.Task, level, name int, outPtr usermem. // blockingAccept implements a blocking version of accept(2), that is, if no // connections are ready to be accept, it will block until one becomes ready. -func (s *SocketVFS2) blockingAccept(t *kernel.Task) (transport.Endpoint, *syserr.Error) { +func (s *SocketVFS2) blockingAccept(t *kernel.Task, peerAddr *tcpip.FullAddress) (transport.Endpoint, *syserr.Error) { // Register for notifications. e, ch := waiter.NewChannelEntry(nil) s.socketOpsCommon.EventRegister(&e, waiter.EventIn) @@ -105,7 +128,7 @@ func (s *SocketVFS2) blockingAccept(t *kernel.Task) (transport.Endpoint, *syserr // Try to accept the connection; if it fails, then wait until we get a // notification. for { - if ep, err := s.ep.Accept(); err != syserr.ErrWouldBlock { + if ep, err := s.ep.Accept(peerAddr); err != syserr.ErrWouldBlock { return ep, err } @@ -118,15 +141,18 @@ func (s *SocketVFS2) blockingAccept(t *kernel.Task) (transport.Endpoint, *syserr // Accept implements the linux syscall accept(2) for sockets backed by // a transport.Endpoint. func (s *SocketVFS2) Accept(t *kernel.Task, peerRequested bool, flags int, blocking bool) (int32, linux.SockAddr, uint32, *syserr.Error) { - // Issue the accept request to get the new endpoint. - ep, err := s.ep.Accept() + var peerAddr *tcpip.FullAddress + if peerRequested { + peerAddr = &tcpip.FullAddress{} + } + ep, err := s.ep.Accept(peerAddr) if err != nil { if err != syserr.ErrWouldBlock || !blocking { return 0, nil, 0, err } var err *syserr.Error - ep, err = s.blockingAccept(t) + ep, err = s.blockingAccept(t, peerAddr) if err != nil { return 0, nil, 0, err } @@ -144,13 +170,8 @@ func (s *SocketVFS2) Accept(t *kernel.Task, peerRequested bool, flags int, block var addr linux.SockAddr var addrLen uint32 - if peerRequested { - // Get address of the peer. - var err *syserr.Error - addr, addrLen, err = ns.Impl().(*SocketVFS2).GetPeerName(t) - if err != nil { - return 0, nil, 0, err - } + if peerAddr != nil { + addr, addrLen = netstack.ConvertAddress(linux.AF_UNIX, *peerAddr) } fd, e := t.NewFDFromVFS2(0, ns, kernel.FDFlags{ diff --git a/pkg/sentry/state/state.go b/pkg/sentry/state/state.go index a06c9b8ab..245d2c5cf 100644 --- a/pkg/sentry/state/state.go +++ b/pkg/sentry/state/state.go @@ -61,8 +61,10 @@ func (opts SaveOpts) Save(k *kernel.Kernel, w *watchdog.Watchdog) error { log.Infof("Sandbox save started, pausing all tasks.") k.Pause() k.ReceiveTaskStates() - defer k.Unpause() - defer log.Infof("Tasks resumed after save.") + defer func() { + k.Unpause() + log.Infof("Tasks resumed after save.") + }() w.Stop() defer w.Start() diff --git a/pkg/sentry/strace/BUILD b/pkg/sentry/strace/BUILD index 88d5db9fc..a920180d3 100644 --- a/pkg/sentry/strace/BUILD +++ b/pkg/sentry/strace/BUILD @@ -28,6 +28,7 @@ go_library( "//pkg/binary", "//pkg/bits", "//pkg/eventchannel", + "//pkg/marshal/primitive", "//pkg/seccomp", "//pkg/sentry/arch", "//pkg/sentry/kernel", diff --git a/pkg/sentry/strace/epoll.go b/pkg/sentry/strace/epoll.go index 5d51a7792..ae3b998c8 100644 --- a/pkg/sentry/strace/epoll.go +++ b/pkg/sentry/strace/epoll.go @@ -26,7 +26,7 @@ import ( func epollEvent(t *kernel.Task, eventAddr usermem.Addr) string { var e linux.EpollEvent - if _, err := t.CopyIn(eventAddr, &e); err != nil { + if _, err := e.CopyIn(t, eventAddr); err != nil { return fmt.Sprintf("%#x {error reading event: %v}", eventAddr, err) } var sb strings.Builder @@ -41,7 +41,7 @@ func epollEvents(t *kernel.Task, eventsAddr usermem.Addr, numEvents, maxBytes ui addr := eventsAddr for i := uint64(0); i < numEvents; i++ { var e linux.EpollEvent - if _, err := t.CopyIn(addr, &e); err != nil { + if _, err := e.CopyIn(t, addr); err != nil { fmt.Fprintf(&sb, "{error reading event at %#x: %v}", addr, err) continue } diff --git a/pkg/sentry/strace/socket.go b/pkg/sentry/strace/socket.go index 08e97e6c4..cc5f70cd4 100644 --- a/pkg/sentry/strace/socket.go +++ b/pkg/sentry/strace/socket.go @@ -21,6 +21,7 @@ import ( "gvisor.dev/gvisor/pkg/abi" "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/binary" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/socket/netlink" "gvisor.dev/gvisor/pkg/sentry/socket/netstack" @@ -166,7 +167,7 @@ func cmsghdr(t *kernel.Task, addr usermem.Addr, length uint64, maxBytes uint64) } buf := make([]byte, length) - if _, err := t.CopyIn(addr, &buf); err != nil { + if _, err := t.CopyInBytes(addr, buf); err != nil { return fmt.Sprintf("%#x (error decoding control: %v)", addr, err) } @@ -302,7 +303,7 @@ func cmsghdr(t *kernel.Task, addr usermem.Addr, length uint64, maxBytes uint64) func msghdr(t *kernel.Task, addr usermem.Addr, printContent bool, maxBytes uint64) string { var msg slinux.MessageHeader64 - if err := slinux.CopyInMessageHeader64(t, addr, &msg); err != nil { + if _, err := msg.CopyIn(t, addr); err != nil { return fmt.Sprintf("%#x (error decoding msghdr: %v)", addr, err) } s := fmt.Sprintf( @@ -380,9 +381,9 @@ func postSockAddr(t *kernel.Task, addr usermem.Addr, lengthPtr usermem.Addr) str func copySockLen(t *kernel.Task, addr usermem.Addr) (uint32, error) { // socklen_t is 32-bits. - var l uint32 - _, err := t.CopyIn(addr, &l) - return l, err + var l primitive.Uint32 + _, err := l.CopyIn(t, addr) + return uint32(l), err } func sockLenPointer(t *kernel.Task, addr usermem.Addr) string { @@ -436,22 +437,22 @@ func getSockOptVal(t *kernel.Task, level, optname uint64, optVal usermem.Addr, o func sockOptVal(t *kernel.Task, level, optname uint64, optVal usermem.Addr, optLen uint64, maximumBlobSize uint) string { switch optLen { case 1: - var v uint8 - _, err := t.CopyIn(optVal, &v) + var v primitive.Uint8 + _, err := v.CopyIn(t, optVal) if err != nil { return fmt.Sprintf("%#x {error reading optval: %v}", optVal, err) } return fmt.Sprintf("%#x {value=%v}", optVal, v) case 2: - var v uint16 - _, err := t.CopyIn(optVal, &v) + var v primitive.Uint16 + _, err := v.CopyIn(t, optVal) if err != nil { return fmt.Sprintf("%#x {error reading optval: %v}", optVal, err) } return fmt.Sprintf("%#x {value=%v}", optVal, v) case 4: - var v uint32 - _, err := t.CopyIn(optVal, &v) + var v primitive.Uint32 + _, err := v.CopyIn(t, optVal) if err != nil { return fmt.Sprintf("%#x {error reading optval: %v}", optVal, err) } diff --git a/pkg/sentry/strace/strace.go b/pkg/sentry/strace/strace.go index 87b239730..396744597 100644 --- a/pkg/sentry/strace/strace.go +++ b/pkg/sentry/strace/strace.go @@ -17,17 +17,16 @@ package strace import ( - "encoding/binary" "fmt" "strconv" "strings" - "syscall" "time" "gvisor.dev/gvisor/pkg/abi" "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/bits" "gvisor.dev/gvisor/pkg/eventchannel" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/seccomp" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/kernel" @@ -91,7 +90,7 @@ func iovecs(t *kernel.Task, addr usermem.Addr, iovcnt int, printContent bool, ma } b := make([]byte, size) - amt, err := t.CopyIn(ar.Start, b) + amt, err := t.CopyInBytes(ar.Start, b) if err != nil { iovs[i] = fmt.Sprintf("{base=%#x, len=%d, %q..., error decoding string: %v}", ar.Start, ar.Length(), b[:amt], err) continue @@ -118,7 +117,7 @@ func dump(t *kernel.Task, addr usermem.Addr, size uint, maximumBlobSize uint) st } b := make([]byte, size) - amt, err := t.CopyIn(addr, b) + amt, err := t.CopyInBytes(addr, b) if err != nil { return fmt.Sprintf("%#x (error decoding string: %s)", addr, err) } @@ -199,7 +198,7 @@ func fdVFS2(t *kernel.Task, fd int32) string { func fdpair(t *kernel.Task, addr usermem.Addr) string { var fds [2]int32 - _, err := t.CopyIn(addr, &fds) + _, err := primitive.CopyInt32SliceIn(t, addr, fds[:]) if err != nil { return fmt.Sprintf("%#x (error decoding fds: %s)", addr, err) } @@ -209,7 +208,7 @@ func fdpair(t *kernel.Task, addr usermem.Addr) string { func uname(t *kernel.Task, addr usermem.Addr) string { var u linux.UtsName - if _, err := t.CopyIn(addr, &u); err != nil { + if _, err := u.CopyIn(t, addr); err != nil { return fmt.Sprintf("%#x (error decoding utsname: %s)", addr, err) } @@ -222,7 +221,7 @@ func utimensTimespec(t *kernel.Task, addr usermem.Addr) string { } var tim linux.Timespec - if _, err := t.CopyIn(addr, &tim); err != nil { + if _, err := tim.CopyIn(t, addr); err != nil { return fmt.Sprintf("%#x (error decoding timespec: %s)", addr, err) } @@ -244,7 +243,7 @@ func timespec(t *kernel.Task, addr usermem.Addr) string { } var tim linux.Timespec - if _, err := t.CopyIn(addr, &tim); err != nil { + if _, err := tim.CopyIn(t, addr); err != nil { return fmt.Sprintf("%#x (error decoding timespec: %s)", addr, err) } return fmt.Sprintf("%#x {sec=%v nsec=%v}", addr, tim.Sec, tim.Nsec) @@ -256,7 +255,7 @@ func timeval(t *kernel.Task, addr usermem.Addr) string { } var tim linux.Timeval - if _, err := t.CopyIn(addr, &tim); err != nil { + if _, err := tim.CopyIn(t, addr); err != nil { return fmt.Sprintf("%#x (error decoding timeval: %s)", addr, err) } @@ -268,8 +267,8 @@ func utimbuf(t *kernel.Task, addr usermem.Addr) string { return "null" } - var utim syscall.Utimbuf - if _, err := t.CopyIn(addr, &utim); err != nil { + var utim linux.Utime + if _, err := utim.CopyIn(t, addr); err != nil { return fmt.Sprintf("%#x (error decoding utimbuf: %s)", addr, err) } @@ -282,7 +281,7 @@ func stat(t *kernel.Task, addr usermem.Addr) string { } var stat linux.Stat - if _, err := t.CopyIn(addr, &stat); err != nil { + if _, err := stat.CopyIn(t, addr); err != nil { return fmt.Sprintf("%#x (error decoding stat: %s)", addr, err) } return fmt.Sprintf("%#x {dev=%d, ino=%d, mode=%s, nlink=%d, uid=%d, gid=%d, rdev=%d, size=%d, blksize=%d, blocks=%d, atime=%s, mtime=%s, ctime=%s}", addr, stat.Dev, stat.Ino, linux.FileMode(stat.Mode), stat.Nlink, stat.UID, stat.GID, stat.Rdev, stat.Size, stat.Blksize, stat.Blocks, time.Unix(stat.ATime.Sec, stat.ATime.Nsec), time.Unix(stat.MTime.Sec, stat.MTime.Nsec), time.Unix(stat.CTime.Sec, stat.CTime.Nsec)) @@ -294,7 +293,7 @@ func itimerval(t *kernel.Task, addr usermem.Addr) string { } interval := timeval(t, addr) - value := timeval(t, addr+usermem.Addr(binary.Size(linux.Timeval{}))) + value := timeval(t, addr+usermem.Addr((*linux.Timeval)(nil).SizeBytes())) return fmt.Sprintf("%#x {interval=%s, value=%s}", addr, interval, value) } @@ -304,7 +303,7 @@ func itimerspec(t *kernel.Task, addr usermem.Addr) string { } interval := timespec(t, addr) - value := timespec(t, addr+usermem.Addr(binary.Size(linux.Timespec{}))) + value := timespec(t, addr+usermem.Addr((*linux.Timespec)(nil).SizeBytes())) return fmt.Sprintf("%#x {interval=%s, value=%s}", addr, interval, value) } @@ -330,7 +329,7 @@ func rusage(t *kernel.Task, addr usermem.Addr) string { } var ru linux.Rusage - if _, err := t.CopyIn(addr, &ru); err != nil { + if _, err := ru.CopyIn(t, addr); err != nil { return fmt.Sprintf("%#x (error decoding rusage: %s)", addr, err) } return fmt.Sprintf("%#x %+v", addr, ru) @@ -342,7 +341,7 @@ func capHeader(t *kernel.Task, addr usermem.Addr) string { } var hdr linux.CapUserHeader - if _, err := t.CopyIn(addr, &hdr); err != nil { + if _, err := hdr.CopyIn(t, addr); err != nil { return fmt.Sprintf("%#x (error decoding header: %s)", addr, err) } @@ -367,7 +366,7 @@ func capData(t *kernel.Task, hdrAddr, dataAddr usermem.Addr) string { } var hdr linux.CapUserHeader - if _, err := t.CopyIn(hdrAddr, &hdr); err != nil { + if _, err := hdr.CopyIn(t, hdrAddr); err != nil { return fmt.Sprintf("%#x (error decoding header: %v)", dataAddr, err) } @@ -376,7 +375,7 @@ func capData(t *kernel.Task, hdrAddr, dataAddr usermem.Addr) string { switch hdr.Version { case linux.LINUX_CAPABILITY_VERSION_1: var data linux.CapUserData - if _, err := t.CopyIn(dataAddr, &data); err != nil { + if _, err := data.CopyIn(t, dataAddr); err != nil { return fmt.Sprintf("%#x (error decoding data: %v)", dataAddr, err) } p = uint64(data.Permitted) @@ -384,7 +383,7 @@ func capData(t *kernel.Task, hdrAddr, dataAddr usermem.Addr) string { e = uint64(data.Effective) case linux.LINUX_CAPABILITY_VERSION_2, linux.LINUX_CAPABILITY_VERSION_3: var data [2]linux.CapUserData - if _, err := t.CopyIn(dataAddr, &data); err != nil { + if _, err := linux.CopyCapUserDataSliceIn(t, dataAddr, data[:]); err != nil { return fmt.Sprintf("%#x (error decoding data: %v)", dataAddr, err) } p = uint64(data[0].Permitted) | (uint64(data[1].Permitted) << 32) diff --git a/pkg/sentry/syscalls/linux/BUILD b/pkg/sentry/syscalls/linux/BUILD index 4a9b04fd0..75752b2e6 100644 --- a/pkg/sentry/syscalls/linux/BUILD +++ b/pkg/sentry/syscalls/linux/BUILD @@ -56,6 +56,7 @@ go_library( "sys_xattr.go", "timespec.go", ], + marshal = True, visibility = ["//:sandbox"], deps = [ "//pkg/abi", @@ -64,6 +65,8 @@ go_library( "//pkg/bpf", "//pkg/context", "//pkg/log", + "//pkg/marshal", + "//pkg/marshal/primitive", "//pkg/metric", "//pkg/rand", "//pkg/safemem", @@ -99,7 +102,5 @@ go_library( "//pkg/syserror", "//pkg/usermem", "//pkg/waiter", - "//tools/go_marshal/marshal", - "//tools/go_marshal/primitive", ], ) diff --git a/pkg/sentry/syscalls/linux/linux64.go b/pkg/sentry/syscalls/linux/linux64.go index da6bd85e1..5f26697d2 100644 --- a/pkg/sentry/syscalls/linux/linux64.go +++ b/pkg/sentry/syscalls/linux/linux64.go @@ -138,7 +138,7 @@ var AMD64 = &kernel.SyscallTable{ 83: syscalls.Supported("mkdir", Mkdir), 84: syscalls.Supported("rmdir", Rmdir), 85: syscalls.Supported("creat", Creat), - 86: syscalls.Supported("link", Link), + 86: syscalls.PartiallySupported("link", Link, "Limited support with Gofer. Link count and linked files may get out of sync because gVisor is not aware of external hardlinks.", nil), 87: syscalls.Supported("unlink", Unlink), 88: syscalls.Supported("symlink", Symlink), 89: syscalls.Supported("readlink", Readlink), @@ -317,7 +317,7 @@ var AMD64 = &kernel.SyscallTable{ 262: syscalls.Supported("fstatat", Fstatat), 263: syscalls.Supported("unlinkat", Unlinkat), 264: syscalls.Supported("renameat", Renameat), - 265: syscalls.Supported("linkat", Linkat), + 265: syscalls.PartiallySupported("linkat", Linkat, "See link(2).", nil), 266: syscalls.Supported("symlinkat", Symlinkat), 267: syscalls.Supported("readlinkat", Readlinkat), 268: syscalls.Supported("fchmodat", Fchmodat), diff --git a/pkg/sentry/syscalls/linux/sys_aio.go b/pkg/sentry/syscalls/linux/sys_aio.go index e9d64dec5..0bf313a13 100644 --- a/pkg/sentry/syscalls/linux/sys_aio.go +++ b/pkg/sentry/syscalls/linux/sys_aio.go @@ -17,6 +17,7 @@ package linux import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/kernel" @@ -36,7 +37,7 @@ func IoSetup(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysca // // The context pointer _must_ be zero initially. var idIn uint64 - if _, err := t.CopyIn(idAddr, &idIn); err != nil { + if _, err := primitive.CopyUint64In(t, idAddr, &idIn); err != nil { return 0, nil, err } if idIn != 0 { @@ -49,7 +50,7 @@ func IoSetup(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysca } // Copy out the new ID. - if _, err := t.CopyOut(idAddr, &id); err != nil { + if _, err := primitive.CopyUint64Out(t, idAddr, id); err != nil { t.MemoryManager().DestroyAIOContext(t, id) return 0, nil, err } @@ -142,7 +143,7 @@ func IoGetevents(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.S ev := v.(*linux.IOEvent) // Copy out the result. - if _, err := t.CopyOut(eventsAddr, ev); err != nil { + if _, err := ev.CopyOut(t, eventsAddr); err != nil { if count > 0 { return uintptr(count), nil, nil } @@ -338,21 +339,27 @@ func IoSubmit(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc } for i := int32(0); i < nrEvents; i++ { - // Copy in the address. - cbAddrNative := t.Arch().Native(0) - if _, err := t.CopyIn(addr, cbAddrNative); err != nil { - if i > 0 { - // Some successful. - return uintptr(i), nil, nil + // Copy in the callback address. + var cbAddr usermem.Addr + switch t.Arch().Width() { + case 8: + var cbAddrP primitive.Uint64 + if _, err := cbAddrP.CopyIn(t, addr); err != nil { + if i > 0 { + // Some successful. + return uintptr(i), nil, nil + } + // Nothing done. + return 0, nil, err } - // Nothing done. - return 0, nil, err + cbAddr = usermem.Addr(cbAddrP) + default: + return 0, nil, syserror.ENOSYS } // Copy in this callback. var cb linux.IOCallback - cbAddr := usermem.Addr(t.Arch().Value(cbAddrNative)) - if _, err := t.CopyIn(cbAddr, &cb); err != nil { + if _, err := cb.CopyIn(t, cbAddr); err != nil { if i > 0 { // Some have been successful. diff --git a/pkg/sentry/syscalls/linux/sys_capability.go b/pkg/sentry/syscalls/linux/sys_capability.go index adf5ea5f2..d3b85e11b 100644 --- a/pkg/sentry/syscalls/linux/sys_capability.go +++ b/pkg/sentry/syscalls/linux/sys_capability.go @@ -45,7 +45,7 @@ func Capget(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal dataAddr := args[1].Pointer() var hdr linux.CapUserHeader - if _, err := t.CopyIn(hdrAddr, &hdr); err != nil { + if _, err := hdr.CopyIn(t, hdrAddr); err != nil { return 0, nil, err } // hdr.Pid doesn't need to be valid if this capget() is a "version probe" @@ -65,7 +65,7 @@ func Capget(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal Permitted: uint32(p), Inheritable: uint32(i), } - _, err = t.CopyOut(dataAddr, &data) + _, err = data.CopyOut(t, dataAddr) return 0, nil, err case linux.LINUX_CAPABILITY_VERSION_2, linux.LINUX_CAPABILITY_VERSION_3: @@ -88,12 +88,12 @@ func Capget(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal Inheritable: uint32(i >> 32), }, } - _, err = t.CopyOut(dataAddr, &data) + _, err = linux.CopyCapUserDataSliceOut(t, dataAddr, data[:]) return 0, nil, err default: hdr.Version = linux.HighestCapabilityVersion - if _, err := t.CopyOut(hdrAddr, &hdr); err != nil { + if _, err := hdr.CopyOut(t, hdrAddr); err != nil { return 0, nil, err } if dataAddr != 0 { @@ -109,7 +109,7 @@ func Capset(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal dataAddr := args[1].Pointer() var hdr linux.CapUserHeader - if _, err := t.CopyIn(hdrAddr, &hdr); err != nil { + if _, err := hdr.CopyIn(t, hdrAddr); err != nil { return 0, nil, err } switch hdr.Version { @@ -118,7 +118,7 @@ func Capset(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal return 0, nil, syserror.EPERM } var data linux.CapUserData - if _, err := t.CopyIn(dataAddr, &data); err != nil { + if _, err := data.CopyIn(t, dataAddr); err != nil { return 0, nil, err } p := auth.CapabilitySet(data.Permitted) & auth.AllCapabilities @@ -131,7 +131,7 @@ func Capset(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal return 0, nil, syserror.EPERM } var data [2]linux.CapUserData - if _, err := t.CopyIn(dataAddr, &data); err != nil { + if _, err := linux.CopyCapUserDataSliceIn(t, dataAddr, data[:]); err != nil { return 0, nil, err } p := (auth.CapabilitySet(data[0].Permitted) | (auth.CapabilitySet(data[1].Permitted) << 32)) & auth.AllCapabilities @@ -141,7 +141,7 @@ func Capset(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal default: hdr.Version = linux.HighestCapabilityVersion - if _, err := t.CopyOut(hdrAddr, &hdr); err != nil { + if _, err := hdr.CopyOut(t, hdrAddr); err != nil { return 0, nil, err } return 0, nil, syserror.EINVAL diff --git a/pkg/sentry/syscalls/linux/sys_file.go b/pkg/sentry/syscalls/linux/sys_file.go index 256422689..98331eb3c 100644 --- a/pkg/sentry/syscalls/linux/sys_file.go +++ b/pkg/sentry/syscalls/linux/sys_file.go @@ -19,6 +19,7 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/fs/lock" @@ -601,19 +602,19 @@ func Ioctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall // Shared flags between file and socket. switch request { case linux.FIONCLEX: - t.FDTable().SetFlags(fd, kernel.FDFlags{ + t.FDTable().SetFlags(t, fd, kernel.FDFlags{ CloseOnExec: false, }) return 0, nil, nil case linux.FIOCLEX: - t.FDTable().SetFlags(fd, kernel.FDFlags{ + t.FDTable().SetFlags(t, fd, kernel.FDFlags{ CloseOnExec: true, }) return 0, nil, nil case linux.FIONBIO: var set int32 - if _, err := t.CopyIn(args[2].Pointer(), &set); err != nil { + if _, err := primitive.CopyInt32In(t, args[2].Pointer(), &set); err != nil { return 0, nil, err } flags := file.Flags() @@ -627,7 +628,7 @@ func Ioctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall case linux.FIOASYNC: var set int32 - if _, err := t.CopyIn(args[2].Pointer(), &set); err != nil { + if _, err := primitive.CopyInt32In(t, args[2].Pointer(), &set); err != nil { return 0, nil, err } flags := file.Flags() @@ -641,15 +642,14 @@ func Ioctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall case linux.FIOSETOWN, linux.SIOCSPGRP: var set int32 - if _, err := t.CopyIn(args[2].Pointer(), &set); err != nil { + if _, err := primitive.CopyInt32In(t, args[2].Pointer(), &set); err != nil { return 0, nil, err } fSetOwn(t, file, set) return 0, nil, nil case linux.FIOGETOWN, linux.SIOCGPGRP: - who := fGetOwn(t, file) - _, err := t.CopyOut(args[2].Pointer(), &who) + _, err := primitive.CopyInt32Out(t, args[2].Pointer(), fGetOwn(t, file)) return 0, nil, err default: @@ -694,7 +694,7 @@ func Getcwd(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal } // Top it off with a terminator. - _, err = t.CopyOut(addr+usermem.Addr(bytes), []byte("\x00")) + _, err = t.CopyOutBytes(addr+usermem.Addr(bytes), []byte("\x00")) return uintptr(bytes + 1), nil, err } @@ -787,7 +787,7 @@ func Close(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall // Note that Remove provides a reference on the file that we may use to // flush. It is still active until we drop the final reference below // (and other reference-holding operations complete). - file, _ := t.FDTable().Remove(fd) + file, _ := t.FDTable().Remove(t, fd) if file == nil { return 0, nil, syserror.EBADF } @@ -941,7 +941,7 @@ func Fcntl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall return uintptr(flags.ToLinuxFDFlags()), nil, nil case linux.F_SETFD: flags := args[2].Uint() - err := t.FDTable().SetFlags(fd, kernel.FDFlags{ + err := t.FDTable().SetFlags(t, fd, kernel.FDFlags{ CloseOnExec: flags&linux.FD_CLOEXEC != 0, }) return 0, nil, err @@ -962,7 +962,7 @@ func Fcntl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall // Copy in the lock request. flockAddr := args[2].Pointer() var flock linux.Flock - if _, err := t.CopyIn(flockAddr, &flock); err != nil { + if _, err := flock.CopyIn(t, flockAddr); err != nil { return 0, nil, err } @@ -1052,12 +1052,12 @@ func Fcntl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall case linux.F_GETOWN_EX: addr := args[2].Pointer() owner := fGetOwnEx(t, file) - _, err := t.CopyOut(addr, &owner) + _, err := owner.CopyOut(t, addr) return 0, nil, err case linux.F_SETOWN_EX: addr := args[2].Pointer() var owner linux.FOwnerEx - _, err := t.CopyIn(addr, &owner) + _, err := owner.CopyIn(t, addr) if err != nil { return 0, nil, err } @@ -1154,6 +1154,10 @@ func Fadvise64(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sys return 0, nil, nil } +// LINT.ThenChange(vfs2/fd.go) + +// LINT.IfChange + func mkdirAt(t *kernel.Task, dirFD int32, addr usermem.Addr, mode linux.FileMode) error { path, _, err := copyInPath(t, addr, false /* allowEmpty */) if err != nil { @@ -1918,7 +1922,7 @@ func Utime(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall ts := defaultSetToSystemTimeSpec() if timesAddr != 0 { var times linux.Utime - if _, err := t.CopyIn(timesAddr, ×); err != nil { + if _, err := times.CopyIn(t, timesAddr); err != nil { return 0, nil, err } ts = fs.TimeSpec{ @@ -1938,7 +1942,7 @@ func Utimes(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal ts := defaultSetToSystemTimeSpec() if timesAddr != 0 { var times [2]linux.Timeval - if _, err := t.CopyIn(timesAddr, ×); err != nil { + if _, err := linux.CopyTimevalSliceIn(t, timesAddr, times[:]); err != nil { return 0, nil, err } ts = fs.TimeSpec{ @@ -1966,7 +1970,7 @@ func Utimensat(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sys ts := defaultSetToSystemTimeSpec() if timesAddr != 0 { var times [2]linux.Timespec - if _, err := t.CopyIn(timesAddr, ×); err != nil { + if _, err := linux.CopyTimespecSliceIn(t, timesAddr, times[:]); err != nil { return 0, nil, err } if !timespecIsValid(times[0]) || !timespecIsValid(times[1]) { @@ -2000,7 +2004,7 @@ func Futimesat(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sys ts := defaultSetToSystemTimeSpec() if timesAddr != 0 { var times [2]linux.Timeval - if _, err := t.CopyIn(timesAddr, ×); err != nil { + if _, err := linux.CopyTimevalSliceIn(t, timesAddr, times[:]); err != nil { return 0, nil, err } if times[0].Usec >= 1e6 || times[0].Usec < 0 || diff --git a/pkg/sentry/syscalls/linux/sys_futex.go b/pkg/sentry/syscalls/linux/sys_futex.go index 12b2fa690..f39ce0639 100644 --- a/pkg/sentry/syscalls/linux/sys_futex.go +++ b/pkg/sentry/syscalls/linux/sys_futex.go @@ -306,8 +306,8 @@ func GetRobustList(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel // Despite the syscall using the name 'pid' for this variable, it is // very much a tid. tid := args[0].Int() - head := args[1].Pointer() - size := args[2].Pointer() + headAddr := args[1].Pointer() + sizeAddr := args[2].Pointer() if tid < 0 { return 0, nil, syserror.EINVAL @@ -321,12 +321,16 @@ func GetRobustList(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel } // Copy out head pointer. - if _, err := t.CopyOut(head, uint64(ot.GetRobustList())); err != nil { + head := t.Arch().Native(uintptr(ot.GetRobustList())) + if _, err := head.CopyOut(t, headAddr); err != nil { return 0, nil, err } - // Copy out size, which is a constant. - if _, err := t.CopyOut(size, uint64(linux.SizeOfRobustListHead)); err != nil { + // Copy out size, which is a constant. Note that while size isn't + // an address, it is defined as the arch-dependent size_t, so it + // needs to be converted to a native-sized int. + size := t.Arch().Native(uintptr(linux.SizeOfRobustListHead)) + if _, err := size.CopyOut(t, sizeAddr); err != nil { return 0, nil, err } diff --git a/pkg/sentry/syscalls/linux/sys_getdents.go b/pkg/sentry/syscalls/linux/sys_getdents.go index 59004cefe..b25f7d881 100644 --- a/pkg/sentry/syscalls/linux/sys_getdents.go +++ b/pkg/sentry/syscalls/linux/sys_getdents.go @@ -19,7 +19,6 @@ import ( "io" "gvisor.dev/gvisor/pkg/abi/linux" - "gvisor.dev/gvisor/pkg/binary" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/kernel" @@ -93,19 +92,23 @@ func getdents(t *kernel.Task, fd int32, addr usermem.Addr, size int, f func(*dir } } -// oldDirentHdr is a fixed sized header matching the fixed size -// fields found in the old linux dirent struct. +// oldDirentHdr is a fixed sized header matching the fixed size fields found in +// the old linux dirent struct. +// +// +marshal type oldDirentHdr struct { Ino uint64 Off uint64 - Reclen uint16 + Reclen uint16 `marshal:"unaligned"` // Struct ends mid-word. } -// direntHdr is a fixed sized header matching the fixed size -// fields found in the new linux dirent struct. +// direntHdr is a fixed sized header matching the fixed size fields found in the +// new linux dirent struct. +// +// +marshal type direntHdr struct { OldHdr oldDirentHdr - Typ uint8 + Typ uint8 `marshal:"unaligned"` // Struct ends mid-word. } // dirent contains the data pointed to by a new linux dirent struct. @@ -134,20 +137,20 @@ func newDirent(width uint, name string, attr fs.DentAttr, offset uint64) *dirent // the old linux dirent format. func smallestDirent(a arch.Context) uint { d := dirent{} - return uint(binary.Size(d.Hdr.OldHdr)) + a.Width() + 1 + return uint(d.Hdr.OldHdr.SizeBytes()) + a.Width() + 1 } // smallestDirent64 returns the size of the smallest possible dirent using // the new linux dirent format. func smallestDirent64(a arch.Context) uint { d := dirent{} - return uint(binary.Size(d.Hdr)) + a.Width() + return uint(d.Hdr.SizeBytes()) + a.Width() } // padRec pads the name field until the rec length is a multiple of the width, // which must be a power of 2. It returns the padded rec length. func (d *dirent) padRec(width int) uint16 { - a := int(binary.Size(d.Hdr)) + len(d.Name) + a := d.Hdr.SizeBytes() + len(d.Name) r := (a + width) &^ (width - 1) padding := r - a d.Name = append(d.Name, make([]byte, padding)...) @@ -157,7 +160,7 @@ func (d *dirent) padRec(width int) uint16 { // Serialize64 serializes a Dirent struct to a byte slice, keeping the new // linux dirent format. Returns the number of bytes serialized or an error. func (d *dirent) Serialize64(w io.Writer) (int, error) { - n1, err := w.Write(binary.Marshal(nil, usermem.ByteOrder, d.Hdr)) + n1, err := d.Hdr.WriteTo(w) if err != nil { return 0, err } @@ -165,14 +168,14 @@ func (d *dirent) Serialize64(w io.Writer) (int, error) { if err != nil { return 0, err } - return n1 + n2, nil + return int(n1) + n2, nil } // Serialize serializes a Dirent struct to a byte slice, using the old linux // dirent format. // Returns the number of bytes serialized or an error. func (d *dirent) Serialize(w io.Writer) (int, error) { - n1, err := w.Write(binary.Marshal(nil, usermem.ByteOrder, d.Hdr.OldHdr)) + n1, err := d.Hdr.OldHdr.WriteTo(w) if err != nil { return 0, err } @@ -184,7 +187,7 @@ func (d *dirent) Serialize(w io.Writer) (int, error) { if err != nil { return 0, err } - return n1 + n2 + n3, nil + return int(n1) + n2 + n3, nil } // direntSerializer implements fs.InodeOperationsInfoSerializer, serializing dirents to an diff --git a/pkg/sentry/syscalls/linux/sys_identity.go b/pkg/sentry/syscalls/linux/sys_identity.go index 715ac45e6..a29d307e5 100644 --- a/pkg/sentry/syscalls/linux/sys_identity.go +++ b/pkg/sentry/syscalls/linux/sys_identity.go @@ -49,13 +49,13 @@ func Getresuid(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sys ruid := c.RealKUID.In(c.UserNamespace).OrOverflow() euid := c.EffectiveKUID.In(c.UserNamespace).OrOverflow() suid := c.SavedKUID.In(c.UserNamespace).OrOverflow() - if _, err := t.CopyOut(ruidAddr, ruid); err != nil { + if _, err := ruid.CopyOut(t, ruidAddr); err != nil { return 0, nil, err } - if _, err := t.CopyOut(euidAddr, euid); err != nil { + if _, err := euid.CopyOut(t, euidAddr); err != nil { return 0, nil, err } - if _, err := t.CopyOut(suidAddr, suid); err != nil { + if _, err := suid.CopyOut(t, suidAddr); err != nil { return 0, nil, err } return 0, nil, nil @@ -84,13 +84,13 @@ func Getresgid(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sys rgid := c.RealKGID.In(c.UserNamespace).OrOverflow() egid := c.EffectiveKGID.In(c.UserNamespace).OrOverflow() sgid := c.SavedKGID.In(c.UserNamespace).OrOverflow() - if _, err := t.CopyOut(rgidAddr, rgid); err != nil { + if _, err := rgid.CopyOut(t, rgidAddr); err != nil { return 0, nil, err } - if _, err := t.CopyOut(egidAddr, egid); err != nil { + if _, err := egid.CopyOut(t, egidAddr); err != nil { return 0, nil, err } - if _, err := t.CopyOut(sgidAddr, sgid); err != nil { + if _, err := sgid.CopyOut(t, sgidAddr); err != nil { return 0, nil, err } return 0, nil, nil @@ -157,7 +157,7 @@ func Getgroups(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sys for i, kgid := range kgids { gids[i] = kgid.In(t.UserNamespace()).OrOverflow() } - if _, err := t.CopyOut(args[1].Pointer(), gids); err != nil { + if _, err := auth.CopyGIDSliceOut(t, args[1].Pointer(), gids); err != nil { return 0, nil, err } return uintptr(len(gids)), nil, nil @@ -173,7 +173,7 @@ func Setgroups(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sys return 0, nil, t.SetExtraGIDs(nil) } gids := make([]auth.GID, size) - if _, err := t.CopyIn(args[1].Pointer(), &gids); err != nil { + if _, err := auth.CopyGIDSliceIn(t, args[1].Pointer(), gids); err != nil { return 0, nil, err } return 0, nil, t.SetExtraGIDs(gids) diff --git a/pkg/sentry/syscalls/linux/sys_mmap.go b/pkg/sentry/syscalls/linux/sys_mmap.go index d0109baa4..cd8dfdfa4 100644 --- a/pkg/sentry/syscalls/linux/sys_mmap.go +++ b/pkg/sentry/syscalls/linux/sys_mmap.go @@ -100,6 +100,15 @@ func Mmap(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallC if err := file.ConfigureMMap(t, &opts); err != nil { return 0, nil, err } + } else if shared { + // Back shared anonymous mappings with a special mappable. + opts.Offset = 0 + m, err := mm.NewSharedAnonMappable(opts.Length, t.Kernel()) + if err != nil { + return 0, nil, err + } + opts.MappingIdentity = m // transfers ownership of m to opts + opts.Mappable = m } rv, err := t.MemoryManager().MMap(t, opts) @@ -239,7 +248,7 @@ func Mincore(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysca return 0, nil, syserror.ENOMEM } resident := bytes.Repeat([]byte{1}, int(mapped/usermem.PageSize)) - _, err := t.CopyOut(vec, resident) + _, err := t.CopyOutBytes(vec, resident) return 0, nil, err } diff --git a/pkg/sentry/syscalls/linux/sys_pipe.go b/pkg/sentry/syscalls/linux/sys_pipe.go index 3149e4aad..849a47476 100644 --- a/pkg/sentry/syscalls/linux/sys_pipe.go +++ b/pkg/sentry/syscalls/linux/sys_pipe.go @@ -16,6 +16,7 @@ package linux import ( "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/kernel" @@ -46,9 +47,9 @@ func pipe2(t *kernel.Task, addr usermem.Addr, flags uint) (uintptr, error) { return 0, err } - if _, err := t.CopyOut(addr, fds); err != nil { + if _, err := primitive.CopyInt32SliceOut(t, addr, fds); err != nil { for _, fd := range fds { - if file, _ := t.FDTable().Remove(fd); file != nil { + if file, _ := t.FDTable().Remove(t, fd); file != nil { file.DecRef(t) } } diff --git a/pkg/sentry/syscalls/linux/sys_poll.go b/pkg/sentry/syscalls/linux/sys_poll.go index 789e2ed5b..254f4c9f9 100644 --- a/pkg/sentry/syscalls/linux/sys_poll.go +++ b/pkg/sentry/syscalls/linux/sys_poll.go @@ -162,7 +162,7 @@ func CopyInPollFDs(t *kernel.Task, addr usermem.Addr, nfds uint) ([]linux.PollFD pfd := make([]linux.PollFD, nfds) if nfds > 0 { - if _, err := t.CopyIn(addr, &pfd); err != nil { + if _, err := linux.CopyPollFDSliceIn(t, addr, pfd); err != nil { return nil, err } } @@ -189,7 +189,7 @@ func doPoll(t *kernel.Task, addr usermem.Addr, nfds uint, timeout time.Duration) // The poll entries are copied out regardless of whether // any are set or not. This aligns with the Linux behavior. if nfds > 0 && err == nil { - if _, err := t.CopyOut(addr, pfd); err != nil { + if _, err := linux.CopyPollFDSliceOut(t, addr, pfd); err != nil { return remainingTimeout, 0, err } } @@ -202,7 +202,7 @@ func CopyInFDSet(t *kernel.Task, addr usermem.Addr, nBytes, nBitsInLastPartialBy set := make([]byte, nBytes) if addr != 0 { - if _, err := t.CopyIn(addr, &set); err != nil { + if _, err := t.CopyInBytes(addr, set); err != nil { return nil, err } // If we only use part of the last byte, mask out the extraneous bits. @@ -329,19 +329,19 @@ func doSelect(t *kernel.Task, nfds int, readFDs, writeFDs, exceptFDs usermem.Add // Copy updated vectors back. if readFDs != 0 { - if _, err := t.CopyOut(readFDs, r); err != nil { + if _, err := t.CopyOutBytes(readFDs, r); err != nil { return 0, err } } if writeFDs != 0 { - if _, err := t.CopyOut(writeFDs, w); err != nil { + if _, err := t.CopyOutBytes(writeFDs, w); err != nil { return 0, err } } if exceptFDs != 0 { - if _, err := t.CopyOut(exceptFDs, e); err != nil { + if _, err := t.CopyOutBytes(exceptFDs, e); err != nil { return 0, err } } diff --git a/pkg/sentry/syscalls/linux/sys_prctl.go b/pkg/sentry/syscalls/linux/sys_prctl.go index 64a725296..a892d2c62 100644 --- a/pkg/sentry/syscalls/linux/sys_prctl.go +++ b/pkg/sentry/syscalls/linux/sys_prctl.go @@ -18,6 +18,7 @@ import ( "fmt" "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/fsbridge" @@ -43,7 +44,7 @@ func Prctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall return 0, nil, nil case linux.PR_GET_PDEATHSIG: - _, err := t.CopyOut(args[1].Pointer(), int32(t.ParentDeathSignal())) + _, err := primitive.CopyInt32Out(t, args[1].Pointer(), int32(t.ParentDeathSignal())) return 0, nil, err case linux.PR_GET_DUMPABLE: @@ -110,7 +111,7 @@ func Prctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall buf[len] = 0 len++ } - _, err := t.CopyOut(addr, buf[:len]) + _, err := t.CopyOutBytes(addr, buf[:len]) if err != nil { return 0, nil, err } diff --git a/pkg/sentry/syscalls/linux/sys_rlimit.go b/pkg/sentry/syscalls/linux/sys_rlimit.go index d5d5b6959..309c183a3 100644 --- a/pkg/sentry/syscalls/linux/sys_rlimit.go +++ b/pkg/sentry/syscalls/linux/sys_rlimit.go @@ -16,6 +16,7 @@ package linux import ( "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/marshal" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/limits" @@ -26,17 +27,13 @@ import ( // rlimit describes an implementation of 'struct rlimit', which may vary from // system-to-system. type rlimit interface { + marshal.Marshallable + // toLimit converts an rlimit to a limits.Limit. toLimit() *limits.Limit // fromLimit converts a limits.Limit to an rlimit. fromLimit(lim limits.Limit) - - // copyIn copies an rlimit from the untrusted app to the kernel. - copyIn(t *kernel.Task, addr usermem.Addr) error - - // copyOut copies an rlimit from the kernel to the untrusted app. - copyOut(t *kernel.Task, addr usermem.Addr) error } // newRlimit returns the appropriate rlimit type for 'struct rlimit' on this system. @@ -50,6 +47,7 @@ func newRlimit(t *kernel.Task) (rlimit, error) { } } +// +marshal type rlimit64 struct { Cur uint64 Max uint64 @@ -70,12 +68,12 @@ func (r *rlimit64) fromLimit(lim limits.Limit) { } func (r *rlimit64) copyIn(t *kernel.Task, addr usermem.Addr) error { - _, err := t.CopyIn(addr, r) + _, err := r.CopyIn(t, addr) return err } func (r *rlimit64) copyOut(t *kernel.Task, addr usermem.Addr) error { - _, err := t.CopyOut(addr, *r) + _, err := r.CopyOut(t, addr) return err } @@ -140,7 +138,8 @@ func Getrlimit(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sys return 0, nil, err } rlim.fromLimit(lim) - return 0, nil, rlim.copyOut(t, addr) + _, err = rlim.CopyOut(t, addr) + return 0, nil, err } // Setrlimit implements linux syscall setrlimit(2). @@ -155,7 +154,7 @@ func Setrlimit(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sys if err != nil { return 0, nil, err } - if err := rlim.copyIn(t, addr); err != nil { + if _, err := rlim.CopyIn(t, addr); err != nil { return 0, nil, syserror.EFAULT } _, err = prlimit64(t, resource, rlim.toLimit()) diff --git a/pkg/sentry/syscalls/linux/sys_rusage.go b/pkg/sentry/syscalls/linux/sys_rusage.go index 1674c7445..ac5c98a54 100644 --- a/pkg/sentry/syscalls/linux/sys_rusage.go +++ b/pkg/sentry/syscalls/linux/sys_rusage.go @@ -80,7 +80,7 @@ func Getrusage(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sys } ru := getrusage(t, which) - _, err := t.CopyOut(addr, &ru) + _, err := ru.CopyOut(t, addr) return 0, nil, err } @@ -104,7 +104,7 @@ func Times(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall CUTime: linux.ClockTFromDuration(cs2.UserTime), CSTime: linux.ClockTFromDuration(cs2.SysTime), } - if _, err := t.CopyOut(addr, &r); err != nil { + if _, err := r.CopyOut(t, addr); err != nil { return 0, nil, err } diff --git a/pkg/sentry/syscalls/linux/sys_sched.go b/pkg/sentry/syscalls/linux/sys_sched.go index 99f6993f5..bfcf44b6f 100644 --- a/pkg/sentry/syscalls/linux/sys_sched.go +++ b/pkg/sentry/syscalls/linux/sys_sched.go @@ -27,8 +27,10 @@ const ( ) // SchedParam replicates struct sched_param in sched.h. +// +// +marshal type SchedParam struct { - schedPriority int64 + schedPriority int32 } // SchedGetparam implements linux syscall sched_getparam(2). @@ -45,7 +47,7 @@ func SchedGetparam(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel return 0, nil, syserror.ESRCH } r := SchedParam{schedPriority: onlyPriority} - if _, err := t.CopyOut(param, r); err != nil { + if _, err := r.CopyOut(t, param); err != nil { return 0, nil, err } @@ -79,7 +81,7 @@ func SchedSetscheduler(t *kernel.Task, args arch.SyscallArguments) (uintptr, *ke return 0, nil, syserror.ESRCH } var r SchedParam - if _, err := t.CopyIn(param, &r); err != nil { + if _, err := r.CopyIn(t, param); err != nil { return 0, nil, syserror.EINVAL } if r.schedPriority != onlyPriority { diff --git a/pkg/sentry/syscalls/linux/sys_seccomp.go b/pkg/sentry/syscalls/linux/sys_seccomp.go index 5b7a66f4d..4fdb4463c 100644 --- a/pkg/sentry/syscalls/linux/sys_seccomp.go +++ b/pkg/sentry/syscalls/linux/sys_seccomp.go @@ -24,6 +24,8 @@ import ( ) // userSockFprog is equivalent to Linux's struct sock_fprog on amd64. +// +// +marshal type userSockFprog struct { // Len is the length of the filter in BPF instructions. Len uint16 @@ -33,7 +35,7 @@ type userSockFprog struct { // Filter is a user pointer to the struct sock_filter array that makes up // the filter program. Filter is a uint64 rather than a usermem.Addr // because usermem.Addr is actually uintptr, which is not a fixed-size - // type, and encoding/binary.Read objects to this. + // type. Filter uint64 } @@ -54,11 +56,11 @@ func seccomp(t *kernel.Task, mode, flags uint64, addr usermem.Addr) error { } var fprog userSockFprog - if _, err := t.CopyIn(addr, &fprog); err != nil { + if _, err := fprog.CopyIn(t, addr); err != nil { return err } filter := make([]linux.BPFInstruction, int(fprog.Len)) - if _, err := t.CopyIn(usermem.Addr(fprog.Filter), &filter); err != nil { + if _, err := linux.CopyBPFInstructionSliceIn(t, usermem.Addr(fprog.Filter), filter); err != nil { return err } compiledFilter, err := bpf.Compile(filter) diff --git a/pkg/sentry/syscalls/linux/sys_sem.go b/pkg/sentry/syscalls/linux/sys_sem.go index 5f54f2456..47dadb800 100644 --- a/pkg/sentry/syscalls/linux/sys_sem.go +++ b/pkg/sentry/syscalls/linux/sys_sem.go @@ -18,6 +18,7 @@ import ( "math" "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/kernel" @@ -66,7 +67,7 @@ func Semop(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall } ops := make([]linux.Sembuf, nsops) - if _, err := t.CopyIn(sembufAddr, ops); err != nil { + if _, err := linux.CopySembufSliceIn(t, sembufAddr, ops); err != nil { return 0, nil, err } @@ -116,8 +117,8 @@ func Semctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal case linux.IPC_SET: arg := args[3].Pointer() - s := linux.SemidDS{} - if _, err := t.CopyIn(arg, &s); err != nil { + var s linux.SemidDS + if _, err := s.CopyIn(t, arg); err != nil { return 0, nil, err } @@ -188,7 +189,7 @@ func setValAll(t *kernel.Task, id int32, array usermem.Addr) error { return syserror.EINVAL } vals := make([]uint16, set.Size()) - if _, err := t.CopyIn(array, vals); err != nil { + if _, err := primitive.CopyUint16SliceIn(t, array, vals); err != nil { return err } creds := auth.CredentialsFromContext(t) @@ -217,7 +218,7 @@ func getValAll(t *kernel.Task, id int32, array usermem.Addr) error { if err != nil { return err } - _, err = t.CopyOut(array, vals) + _, err = primitive.CopyUint16SliceOut(t, array, vals) return err } diff --git a/pkg/sentry/syscalls/linux/sys_shm.go b/pkg/sentry/syscalls/linux/sys_shm.go index f0ae8fa8e..584064143 100644 --- a/pkg/sentry/syscalls/linux/sys_shm.go +++ b/pkg/sentry/syscalls/linux/sys_shm.go @@ -112,18 +112,18 @@ func Shmctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal stat, err := segment.IPCStat(t) if err == nil { - _, err = t.CopyOut(buf, stat) + _, err = stat.CopyOut(t, buf) } return 0, nil, err case linux.IPC_INFO: params := r.IPCInfo() - _, err := t.CopyOut(buf, params) + _, err := params.CopyOut(t, buf) return 0, nil, err case linux.SHM_INFO: info := r.ShmInfo() - _, err := t.CopyOut(buf, info) + _, err := info.CopyOut(t, buf) return 0, nil, err } @@ -137,11 +137,10 @@ func Shmctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal switch cmd { case linux.IPC_SET: var ds linux.ShmidDS - _, err = t.CopyIn(buf, &ds) - if err != nil { + if _, err = ds.CopyIn(t, buf); err != nil { return 0, nil, err } - err = segment.Set(t, &ds) + err := segment.Set(t, &ds) return 0, nil, err case linux.IPC_RMID: diff --git a/pkg/sentry/syscalls/linux/sys_socket.go b/pkg/sentry/syscalls/linux/sys_socket.go index 38f573c14..9feaca0da 100644 --- a/pkg/sentry/syscalls/linux/sys_socket.go +++ b/pkg/sentry/syscalls/linux/sys_socket.go @@ -19,6 +19,8 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/binary" + "gvisor.dev/gvisor/pkg/marshal" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/kernel" @@ -29,8 +31,6 @@ import ( "gvisor.dev/gvisor/pkg/syserr" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/usermem" - "gvisor.dev/gvisor/tools/go_marshal/marshal" - "gvisor.dev/gvisor/tools/go_marshal/primitive" ) // LINT.IfChange @@ -67,10 +67,10 @@ const flagsOffset = 48 const sizeOfInt32 = 4 // messageHeader64Len is the length of a MessageHeader64 struct. -var messageHeader64Len = uint64(binary.Size(MessageHeader64{})) +var messageHeader64Len = uint64((*MessageHeader64)(nil).SizeBytes()) // multipleMessageHeader64Len is the length of a multipeMessageHeader64 struct. -var multipleMessageHeader64Len = uint64(binary.Size(multipleMessageHeader64{})) +var multipleMessageHeader64Len = uint64((*multipleMessageHeader64)(nil).SizeBytes()) // baseRecvFlags are the flags that are accepted across recvmsg(2), // recvmmsg(2), and recvfrom(2). @@ -78,6 +78,8 @@ const baseRecvFlags = linux.MSG_OOB | linux.MSG_DONTROUTE | linux.MSG_DONTWAIT | // MessageHeader64 is the 64-bit representation of the msghdr struct used in // the recvmsg and sendmsg syscalls. +// +// +marshal type MessageHeader64 struct { // Name is the optional pointer to a network address buffer. Name uint64 @@ -106,30 +108,14 @@ type MessageHeader64 struct { // multipleMessageHeader64 is the 64-bit representation of the mmsghdr struct used in // the recvmmsg and sendmmsg syscalls. +// +// +marshal type multipleMessageHeader64 struct { msgHdr MessageHeader64 msgLen uint32 _ int32 } -// CopyInMessageHeader64 copies a message header from user to kernel memory. -func CopyInMessageHeader64(t *kernel.Task, addr usermem.Addr, msg *MessageHeader64) error { - b := t.CopyScratchBuffer(52) - if _, err := t.CopyInBytes(addr, b); err != nil { - return err - } - - msg.Name = usermem.ByteOrder.Uint64(b[0:]) - msg.NameLen = usermem.ByteOrder.Uint32(b[8:]) - msg.Iov = usermem.ByteOrder.Uint64(b[16:]) - msg.IovLen = usermem.ByteOrder.Uint64(b[24:]) - msg.Control = usermem.ByteOrder.Uint64(b[32:]) - msg.ControlLen = usermem.ByteOrder.Uint64(b[40:]) - msg.Flags = int32(usermem.ByteOrder.Uint32(b[48:])) - - return nil -} - // CaptureAddress allocates memory for and copies a socket address structure // from the untrusted address space range. func CaptureAddress(t *kernel.Task, addr usermem.Addr, addrlen uint32) ([]byte, error) { @@ -148,10 +134,10 @@ func CaptureAddress(t *kernel.Task, addr usermem.Addr, addrlen uint32) ([]byte, // writeAddress writes a sockaddr structure and its length to an output buffer // in the unstrusted address space range. If the address is bigger than the // buffer, it is truncated. -func writeAddress(t *kernel.Task, addr interface{}, addrLen uint32, addrPtr usermem.Addr, addrLenPtr usermem.Addr) error { +func writeAddress(t *kernel.Task, addr linux.SockAddr, addrLen uint32, addrPtr usermem.Addr, addrLenPtr usermem.Addr) error { // Get the buffer length. var bufLen uint32 - if _, err := t.CopyIn(addrLenPtr, &bufLen); err != nil { + if _, err := primitive.CopyUint32In(t, addrLenPtr, &bufLen); err != nil { return err } @@ -160,7 +146,7 @@ func writeAddress(t *kernel.Task, addr interface{}, addrLen uint32, addrPtr user } // Write the length unconditionally. - if _, err := t.CopyOut(addrLenPtr, addrLen); err != nil { + if _, err := primitive.CopyUint32Out(t, addrLenPtr, addrLen); err != nil { return err } @@ -173,7 +159,8 @@ func writeAddress(t *kernel.Task, addr interface{}, addrLen uint32, addrPtr user } // Copy as much of the address as will fit in the buffer. - encodedAddr := binary.Marshal(nil, usermem.ByteOrder, addr) + encodedAddr := t.CopyScratchBuffer(addr.SizeBytes()) + addr.MarshalUnsafe(encodedAddr) if bufLen > uint32(len(encodedAddr)) { bufLen = uint32(len(encodedAddr)) } @@ -247,9 +234,9 @@ func SocketPair(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sy } // Copy the file descriptors out. - if _, err := t.CopyOut(socks, fds); err != nil { + if _, err := primitive.CopyInt32SliceOut(t, socks, fds); err != nil { for _, fd := range fds { - if file, _ := t.FDTable().Remove(fd); file != nil { + if file, _ := t.FDTable().Remove(t, fd); file != nil { file.DecRef(t) } } @@ -456,8 +443,8 @@ func GetSockOpt(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sy } // Read the length. Reject negative values. - optLen := int32(0) - if _, err := t.CopyIn(optLenAddr, &optLen); err != nil { + var optLen int32 + if _, err := primitive.CopyInt32In(t, optLenAddr, &optLen); err != nil { return 0, nil, err } if optLen < 0 { @@ -471,7 +458,7 @@ func GetSockOpt(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sy } vLen := int32(binary.Size(v)) - if _, err := t.CopyOut(optLenAddr, vLen); err != nil { + if _, err := primitive.CopyInt32Out(t, optLenAddr, vLen); err != nil { return 0, nil, err } @@ -733,7 +720,7 @@ func RecvMMsg(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc if !ok { return 0, nil, syserror.EFAULT } - if _, err = t.CopyOut(lp, uint32(n)); err != nil { + if _, err = primitive.CopyUint32Out(t, lp, uint32(n)); err != nil { break } count++ @@ -748,7 +735,7 @@ func RecvMMsg(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc func recvSingleMsg(t *kernel.Task, s socket.Socket, msgPtr usermem.Addr, flags int32, haveDeadline bool, deadline ktime.Time) (uintptr, error) { // Capture the message header and io vectors. var msg MessageHeader64 - if err := CopyInMessageHeader64(t, msgPtr, &msg); err != nil { + if _, err := msg.CopyIn(t, msgPtr); err != nil { return 0, err } @@ -780,7 +767,7 @@ func recvSingleMsg(t *kernel.Task, s socket.Socket, msgPtr usermem.Addr, flags i if int(msg.Flags) != mflags { // Copy out the flags to the caller. - if _, err := t.CopyOut(msgPtr+flagsOffset, int32(mflags)); err != nil { + if _, err := primitive.CopyInt32Out(t, msgPtr+flagsOffset, int32(mflags)); err != nil { return 0, err } } @@ -817,17 +804,17 @@ func recvSingleMsg(t *kernel.Task, s socket.Socket, msgPtr usermem.Addr, flags i } // Copy the control data to the caller. - if _, err := t.CopyOut(msgPtr+controlLenOffset, uint64(len(controlData))); err != nil { + if _, err := primitive.CopyUint64Out(t, msgPtr+controlLenOffset, uint64(len(controlData))); err != nil { return 0, err } if len(controlData) > 0 { - if _, err := t.CopyOut(usermem.Addr(msg.Control), controlData); err != nil { + if _, err := t.CopyOutBytes(usermem.Addr(msg.Control), controlData); err != nil { return 0, err } } // Copy out the flags to the caller. - if _, err := t.CopyOut(msgPtr+flagsOffset, int32(mflags)); err != nil { + if _, err := primitive.CopyInt32Out(t, msgPtr+flagsOffset, int32(mflags)); err != nil { return 0, err } @@ -996,7 +983,7 @@ func SendMMsg(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc if !ok { return 0, nil, syserror.EFAULT } - if _, err = t.CopyOut(lp, uint32(n)); err != nil { + if _, err = primitive.CopyUint32Out(t, lp, uint32(n)); err != nil { break } count++ @@ -1011,7 +998,7 @@ func SendMMsg(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc func sendSingleMsg(t *kernel.Task, s socket.Socket, file *fs.File, msgPtr usermem.Addr, flags int32) (uintptr, error) { // Capture the message header. var msg MessageHeader64 - if err := CopyInMessageHeader64(t, msgPtr, &msg); err != nil { + if _, err := msg.CopyIn(t, msgPtr); err != nil { return 0, err } @@ -1022,7 +1009,7 @@ func sendSingleMsg(t *kernel.Task, s socket.Socket, file *fs.File, msgPtr userme return 0, syserror.ENOBUFS } controlData = make([]byte, msg.ControlLen) - if _, err := t.CopyIn(usermem.Addr(msg.Control), &controlData); err != nil { + if _, err := t.CopyInBytes(usermem.Addr(msg.Control), controlData); err != nil { return 0, err } } diff --git a/pkg/sentry/syscalls/linux/sys_splice.go b/pkg/sentry/syscalls/linux/sys_splice.go index c69941feb..46616c961 100644 --- a/pkg/sentry/syscalls/linux/sys_splice.go +++ b/pkg/sentry/syscalls/linux/sys_splice.go @@ -16,6 +16,7 @@ package linux import ( "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/kernel" @@ -141,7 +142,7 @@ func Sendfile(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc // Copy in the offset. var offset int64 - if _, err := t.CopyIn(offsetAddr, &offset); err != nil { + if _, err := primitive.CopyInt64In(t, offsetAddr, &offset); err != nil { return 0, nil, err } @@ -149,11 +150,11 @@ func Sendfile(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc n, err = doSplice(t, outFile, inFile, fs.SpliceOpts{ Length: count, SrcOffset: true, - SrcStart: offset, + SrcStart: int64(offset), }, outFile.Flags().NonBlocking) // Copy out the new offset. - if _, err := t.CopyOut(offsetAddr, n+offset); err != nil { + if _, err := primitive.CopyInt64Out(t, offsetAddr, offset+n); err != nil { return 0, nil, err } } else { @@ -228,7 +229,7 @@ func Splice(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal } var offset int64 - if _, err := t.CopyIn(outOffset, &offset); err != nil { + if _, err := primitive.CopyInt64In(t, outOffset, &offset); err != nil { return 0, nil, err } @@ -246,7 +247,7 @@ func Splice(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal } var offset int64 - if _, err := t.CopyIn(inOffset, &offset); err != nil { + if _, err := primitive.CopyInt64In(t, inOffset, &offset); err != nil { return 0, nil, err } diff --git a/pkg/sentry/syscalls/linux/sys_stat.go b/pkg/sentry/syscalls/linux/sys_stat.go index a5826f2dd..cda29a8b5 100644 --- a/pkg/sentry/syscalls/linux/sys_stat.go +++ b/pkg/sentry/syscalls/linux/sys_stat.go @@ -221,7 +221,7 @@ func statx(t *kernel.Task, sattr fs.StableAttr, uattr fs.UnstableAttr, statxAddr DevMajor: uint32(devMajor), DevMinor: devMinor, } - _, err := t.CopyOut(statxAddr, &s) + _, err := s.CopyOut(t, statxAddr) return err } @@ -283,7 +283,7 @@ func statfsImpl(t *kernel.Task, d *fs.Dirent, addr usermem.Addr) error { FragmentSize: d.Inode.StableAttr.BlockSize, // Leave other fields 0 like simple_statfs does. } - _, err = t.CopyOut(addr, &statfs) + _, err = statfs.CopyOut(t, addr) return err } diff --git a/pkg/sentry/syscalls/linux/sys_sysinfo.go b/pkg/sentry/syscalls/linux/sys_sysinfo.go index 297de052a..674d341b6 100644 --- a/pkg/sentry/syscalls/linux/sys_sysinfo.go +++ b/pkg/sentry/syscalls/linux/sys_sysinfo.go @@ -43,6 +43,6 @@ func Sysinfo(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysca FreeRAM: memFree, Unit: 1, } - _, err := t.CopyOut(addr, si) + _, err := si.CopyOut(t, addr) return 0, nil, err } diff --git a/pkg/sentry/syscalls/linux/sys_thread.go b/pkg/sentry/syscalls/linux/sys_thread.go index 101096038..39ca9ea97 100644 --- a/pkg/sentry/syscalls/linux/sys_thread.go +++ b/pkg/sentry/syscalls/linux/sys_thread.go @@ -19,6 +19,7 @@ import ( "syscall" "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/fsbridge" @@ -311,13 +312,13 @@ func wait4(t *kernel.Task, pid int, statusAddr usermem.Addr, options int, rusage return 0, err } if statusAddr != 0 { - if _, err := t.CopyOut(statusAddr, wr.Status); err != nil { + if _, err := primitive.CopyUint32Out(t, statusAddr, wr.Status); err != nil { return 0, err } } if rusageAddr != 0 { ru := getrusage(wr.Task, linux.RUSAGE_BOTH) - if _, err := t.CopyOut(rusageAddr, &ru); err != nil { + if _, err := ru.CopyOut(t, rusageAddr); err != nil { return 0, err } } @@ -395,14 +396,14 @@ func Waitid(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal // as well. if infop != 0 { var si arch.SignalInfo - _, err = t.CopyOut(infop, &si) + _, err = si.CopyOut(t, infop) } } return 0, nil, err } if rusageAddr != 0 { ru := getrusage(wr.Task, linux.RUSAGE_BOTH) - if _, err := t.CopyOut(rusageAddr, &ru); err != nil { + if _, err := ru.CopyOut(t, rusageAddr); err != nil { return 0, nil, err } } @@ -441,7 +442,7 @@ func Waitid(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal default: t.Warningf("waitid got incomprehensible wait status %d", s) } - _, err = t.CopyOut(infop, &si) + _, err = si.CopyOut(t, infop) return 0, nil, err } @@ -558,9 +559,7 @@ func Getcpu(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal // third argument to this system call is nowadays unused. if cpu != 0 { - buf := t.CopyScratchBuffer(4) - usermem.ByteOrder.PutUint32(buf, uint32(t.CPU())) - if _, err := t.CopyOutBytes(cpu, buf); err != nil { + if _, err := primitive.CopyInt32Out(t, cpu, t.CPU()); err != nil { return 0, nil, err } } diff --git a/pkg/sentry/syscalls/linux/sys_time.go b/pkg/sentry/syscalls/linux/sys_time.go index a2a24a027..c5054d2f1 100644 --- a/pkg/sentry/syscalls/linux/sys_time.go +++ b/pkg/sentry/syscalls/linux/sys_time.go @@ -19,6 +19,7 @@ import ( "time" "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/kernel" ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time" @@ -168,7 +169,7 @@ func Time(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallC return uintptr(r), nil, nil } - if _, err := t.CopyOut(addr, r); err != nil { + if _, err := r.CopyOut(t, addr); err != nil { return 0, nil, err } return uintptr(r), nil, nil @@ -334,8 +335,8 @@ func Gettimeofday(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel. // Ask the time package for the timezone. _, offset := time.Now().Zone() // This int32 array mimics linux's struct timezone. - timezone := [2]int32{-int32(offset) / 60, 0} - _, err := t.CopyOut(tz, timezone) + timezone := []int32{-int32(offset) / 60, 0} + _, err := primitive.CopyInt32SliceOut(t, tz, timezone) return 0, nil, err } return 0, nil, nil diff --git a/pkg/sentry/syscalls/linux/sys_timer.go b/pkg/sentry/syscalls/linux/sys_timer.go index a4c400f87..45eef4feb 100644 --- a/pkg/sentry/syscalls/linux/sys_timer.go +++ b/pkg/sentry/syscalls/linux/sys_timer.go @@ -21,81 +21,63 @@ import ( "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/syserror" - "gvisor.dev/gvisor/pkg/usermem" ) const nsecPerSec = int64(time.Second) -// copyItimerValIn copies an ItimerVal from the untrusted app range to the -// kernel. The ItimerVal may be either 32 or 64 bits. -// A NULL address is allowed because because Linux allows -// setitimer(which, NULL, &old_value) which disables the timer. -// There is a KERN_WARN message saying this misfeature will be removed. -// However, that hasn't happened as of 3.19, so we continue to support it. -func copyItimerValIn(t *kernel.Task, addr usermem.Addr) (linux.ItimerVal, error) { - if addr == usermem.Addr(0) { - return linux.ItimerVal{}, nil - } - - switch t.Arch().Width() { - case 8: - // Native size, just copy directly. - var itv linux.ItimerVal - if _, err := t.CopyIn(addr, &itv); err != nil { - return linux.ItimerVal{}, err - } - - return itv, nil - default: - return linux.ItimerVal{}, syserror.ENOSYS - } -} - -// copyItimerValOut copies an ItimerVal to the untrusted app range. -// The ItimerVal may be either 32 or 64 bits. -// A NULL address is allowed, in which case no copy takes place -func copyItimerValOut(t *kernel.Task, addr usermem.Addr, itv *linux.ItimerVal) error { - if addr == usermem.Addr(0) { - return nil - } - - switch t.Arch().Width() { - case 8: - // Native size, just copy directly. - _, err := t.CopyOut(addr, itv) - return err - default: - return syserror.ENOSYS - } -} - // Getitimer implements linux syscall getitimer(2). func Getitimer(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { + if t.Arch().Width() != 8 { + // Definition of linux.ItimerVal assumes 64-bit architecture. + return 0, nil, syserror.ENOSYS + } + timerID := args[0].Int() - val := args[1].Pointer() + addr := args[1].Pointer() olditv, err := t.Getitimer(timerID) if err != nil { return 0, nil, err } - return 0, nil, copyItimerValOut(t, val, &olditv) + // A NULL address is allowed, in which case no copy out takes place. + if addr == 0 { + return 0, nil, nil + } + _, err = olditv.CopyOut(t, addr) + return 0, nil, err } // Setitimer implements linux syscall setitimer(2). func Setitimer(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { - timerID := args[0].Int() - newVal := args[1].Pointer() - oldVal := args[2].Pointer() + if t.Arch().Width() != 8 { + // Definition of linux.ItimerVal assumes 64-bit architecture. + return 0, nil, syserror.ENOSYS + } - newitv, err := copyItimerValIn(t, newVal) - if err != nil { - return 0, nil, err + timerID := args[0].Int() + newAddr := args[1].Pointer() + oldAddr := args[2].Pointer() + + var newitv linux.ItimerVal + // A NULL address is allowed because because Linux allows + // setitimer(which, NULL, &old_value) which disables the timer. There is a + // KERN_WARN message saying this misfeature will be removed. However, that + // hasn't happened as of 3.19, so we continue to support it. + if newAddr != 0 { + if _, err := newitv.CopyIn(t, newAddr); err != nil { + return 0, nil, err + } } olditv, err := t.Setitimer(timerID, newitv) if err != nil { return 0, nil, err } - return 0, nil, copyItimerValOut(t, oldVal, &olditv) + // A NULL address is allowed, in which case no copy out takes place. + if oldAddr == 0 { + return 0, nil, nil + } + _, err = olditv.CopyOut(t, oldAddr) + return 0, nil, err } // Alarm implements linux syscall alarm(2). @@ -131,7 +113,7 @@ func TimerCreate(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.S var sev *linux.Sigevent if sevp != 0 { sev = &linux.Sigevent{} - if _, err = t.CopyIn(sevp, sev); err != nil { + if _, err = sev.CopyIn(t, sevp); err != nil { return 0, nil, err } } @@ -141,7 +123,7 @@ func TimerCreate(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.S return 0, nil, err } - if _, err := t.CopyOut(timerIDp, &id); err != nil { + if _, err := id.CopyOut(t, timerIDp); err != nil { t.IntervalTimerDelete(id) return 0, nil, err } @@ -157,7 +139,7 @@ func TimerSettime(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel. oldValAddr := args[3].Pointer() var newVal linux.Itimerspec - if _, err := t.CopyIn(newValAddr, &newVal); err != nil { + if _, err := newVal.CopyIn(t, newValAddr); err != nil { return 0, nil, err } oldVal, err := t.IntervalTimerSettime(timerID, newVal, flags&linux.TIMER_ABSTIME != 0) @@ -165,9 +147,8 @@ func TimerSettime(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel. return 0, nil, err } if oldValAddr != 0 { - if _, err := t.CopyOut(oldValAddr, &oldVal); err != nil { - return 0, nil, err - } + _, err = oldVal.CopyOut(t, oldValAddr) + return 0, nil, err } return 0, nil, nil } @@ -181,7 +162,7 @@ func TimerGettime(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel. if err != nil { return 0, nil, err } - _, err = t.CopyOut(curValAddr, &curVal) + _, err = curVal.CopyOut(t, curValAddr) return 0, nil, err } diff --git a/pkg/sentry/syscalls/linux/sys_timerfd.go b/pkg/sentry/syscalls/linux/sys_timerfd.go index 34b03e4ee..cadd9d348 100644 --- a/pkg/sentry/syscalls/linux/sys_timerfd.go +++ b/pkg/sentry/syscalls/linux/sys_timerfd.go @@ -81,7 +81,7 @@ func TimerfdSettime(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kerne } var newVal linux.Itimerspec - if _, err := t.CopyIn(newValAddr, &newVal); err != nil { + if _, err := newVal.CopyIn(t, newValAddr); err != nil { return 0, nil, err } newS, err := ktime.SettingFromItimerspec(newVal, flags&linux.TFD_TIMER_ABSTIME != 0, tf.Clock()) @@ -91,7 +91,7 @@ func TimerfdSettime(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kerne tm, oldS := tf.SetTime(newS) if oldValAddr != 0 { oldVal := ktime.ItimerspecFromSetting(tm, oldS) - if _, err := t.CopyOut(oldValAddr, &oldVal); err != nil { + if _, err := oldVal.CopyOut(t, oldValAddr); err != nil { return 0, nil, err } } @@ -116,6 +116,6 @@ func TimerfdGettime(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kerne tm, s := tf.GetTime() curVal := ktime.ItimerspecFromSetting(tm, s) - _, err := t.CopyOut(curValAddr, &curVal) + _, err := curVal.CopyOut(t, curValAddr) return 0, nil, err } diff --git a/pkg/sentry/syscalls/linux/sys_tls_amd64.go b/pkg/sentry/syscalls/linux/sys_tls_amd64.go index b3eb96a1c..6ddd30d5c 100644 --- a/pkg/sentry/syscalls/linux/sys_tls_amd64.go +++ b/pkg/sentry/syscalls/linux/sys_tls_amd64.go @@ -18,6 +18,7 @@ package linux import ( "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/syserror" @@ -30,17 +31,19 @@ func ArchPrctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sys case linux.ARCH_GET_FS: addr := args[1].Pointer() fsbase := t.Arch().TLS() - _, err := t.CopyOut(addr, uint64(fsbase)) - if err != nil { - return 0, nil, err + switch t.Arch().Width() { + case 8: + if _, err := primitive.CopyUint64Out(t, addr, uint64(fsbase)); err != nil { + return 0, nil, err + } + default: + return 0, nil, syserror.ENOSYS } - case linux.ARCH_SET_FS: fsbase := args[1].Uint64() if !t.Arch().SetTLS(uintptr(fsbase)) { return 0, nil, syserror.EPERM } - case linux.ARCH_GET_GS, linux.ARCH_SET_GS: t.Kernel().EmitUnimplementedEvent(t) fallthrough diff --git a/pkg/sentry/syscalls/linux/sys_utsname.go b/pkg/sentry/syscalls/linux/sys_utsname.go index e9d702e8e..66c5974f5 100644 --- a/pkg/sentry/syscalls/linux/sys_utsname.go +++ b/pkg/sentry/syscalls/linux/sys_utsname.go @@ -46,7 +46,7 @@ func Uname(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall // Copy out the result. va := args[0].Pointer() - _, err := t.CopyOut(va, u) + _, err := u.CopyOut(t, va) return 0, nil, err } diff --git a/pkg/sentry/syscalls/linux/vfs2/BUILD b/pkg/sentry/syscalls/linux/vfs2/BUILD index 64696b438..9ee766552 100644 --- a/pkg/sentry/syscalls/linux/vfs2/BUILD +++ b/pkg/sentry/syscalls/linux/vfs2/BUILD @@ -44,6 +44,9 @@ go_library( "//pkg/context", "//pkg/fspath", "//pkg/gohacks", + "//pkg/log", + "//pkg/marshal", + "//pkg/marshal/primitive", "//pkg/sentry/arch", "//pkg/sentry/fs/lock", "//pkg/sentry/fsbridge", @@ -72,7 +75,5 @@ go_library( "//pkg/syserror", "//pkg/usermem", "//pkg/waiter", - "//tools/go_marshal/marshal", - "//tools/go_marshal/primitive", ], ) diff --git a/pkg/sentry/syscalls/linux/vfs2/aio.go b/pkg/sentry/syscalls/linux/vfs2/aio.go index 42559bf69..6d0a38330 100644 --- a/pkg/sentry/syscalls/linux/vfs2/aio.go +++ b/pkg/sentry/syscalls/linux/vfs2/aio.go @@ -17,6 +17,7 @@ package vfs2 import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/fsimpl/eventfd" "gvisor.dev/gvisor/pkg/sentry/kernel" @@ -38,21 +39,27 @@ func IoSubmit(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc } for i := int32(0); i < nrEvents; i++ { - // Copy in the address. - cbAddrNative := t.Arch().Native(0) - if _, err := t.CopyIn(addr, cbAddrNative); err != nil { - if i > 0 { - // Some successful. - return uintptr(i), nil, nil + // Copy in the callback address. + var cbAddr usermem.Addr + switch t.Arch().Width() { + case 8: + var cbAddrP primitive.Uint64 + if _, err := cbAddrP.CopyIn(t, addr); err != nil { + if i > 0 { + // Some successful. + return uintptr(i), nil, nil + } + // Nothing done. + return 0, nil, err } - // Nothing done. - return 0, nil, err + cbAddr = usermem.Addr(cbAddrP) + default: + return 0, nil, syserror.ENOSYS } // Copy in this callback. var cb linux.IOCallback - cbAddr := usermem.Addr(t.Arch().Value(cbAddrNative)) - if _, err := t.CopyIn(cbAddr, &cb); err != nil { + if _, err := cb.CopyIn(t, cbAddr); err != nil { if i > 0 { // Some have been successful. return uintptr(i), nil, nil diff --git a/pkg/sentry/syscalls/linux/vfs2/epoll.go b/pkg/sentry/syscalls/linux/vfs2/epoll.go index c62f03509..d0cbb77eb 100644 --- a/pkg/sentry/syscalls/linux/vfs2/epoll.go +++ b/pkg/sentry/syscalls/linux/vfs2/epoll.go @@ -24,7 +24,6 @@ import ( ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time" "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/syserror" - "gvisor.dev/gvisor/pkg/usermem" "gvisor.dev/gvisor/pkg/waiter" ) @@ -141,50 +140,26 @@ func EpollWait(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sys return 0, nil, syserror.EINVAL } - // Use a fixed-size buffer in a loop, instead of make([]linux.EpollEvent, - // maxEvents), so that the buffer can be allocated on the stack. + // Allocate space for a few events on the stack for the common case in + // which we don't have too many events. var ( - events [16]linux.EpollEvent - total int + eventsArr [16]linux.EpollEvent ch chan struct{} haveDeadline bool deadline ktime.Time ) for { - batchEvents := len(events) - if batchEvents > maxEvents { - batchEvents = maxEvents - } - n := ep.ReadEvents(events[:batchEvents]) - maxEvents -= n - if n != 0 { - // Copy what we read out. - copiedBytes, err := linux.CopyEpollEventSliceOut(t, eventsAddr, events[:n]) + events := ep.ReadEvents(eventsArr[:0], maxEvents) + if len(events) != 0 { + copiedBytes, err := linux.CopyEpollEventSliceOut(t, eventsAddr, events) copiedEvents := copiedBytes / sizeofEpollEvent // rounded down - eventsAddr += usermem.Addr(copiedEvents * sizeofEpollEvent) - total += copiedEvents - if err != nil { - if total != 0 { - return uintptr(total), nil, nil - } - return 0, nil, err - } - // If we've filled the application's event buffer, we're done. - if maxEvents == 0 { - return uintptr(total), nil, nil - } - // Loop if we read a full batch, under the expectation that there - // may be more events to read. - if n == batchEvents { - continue + if copiedEvents != 0 { + return uintptr(copiedEvents), nil, nil } + return 0, nil, err } - // We get here if n != batchEvents. If we read any number of events - // (just now, or in a previous iteration of this loop), or if timeout - // is 0 (such that epoll_wait should be non-blocking), return the - // events we've read so far to the application. - if total != 0 || timeout == 0 { - return uintptr(total), nil, nil + if timeout == 0 { + return 0, nil, nil } // In the first iteration of this loop, register with the epoll // instance for readability events, but then immediately continue the @@ -207,8 +182,6 @@ func EpollWait(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sys if err == syserror.ETIMEDOUT { err = nil } - // total must be 0 since otherwise we would have returned - // above. return 0, nil, err } } diff --git a/pkg/sentry/syscalls/linux/vfs2/fd.go b/pkg/sentry/syscalls/linux/vfs2/fd.go index 4856554fe..d8b8d9783 100644 --- a/pkg/sentry/syscalls/linux/vfs2/fd.go +++ b/pkg/sentry/syscalls/linux/vfs2/fd.go @@ -34,7 +34,7 @@ func Close(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall // Note that Remove provides a reference on the file that we may use to // flush. It is still active until we drop the final reference below // (and other reference-holding operations complete). - _, file := t.FDTable().Remove(fd) + _, file := t.FDTable().Remove(t, fd) if file == nil { return 0, nil, syserror.EBADF } @@ -137,7 +137,7 @@ func Fcntl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall return uintptr(flags.ToLinuxFDFlags()), nil, nil case linux.F_SETFD: flags := args[2].Uint() - err := t.FDTable().SetFlagsVFS2(fd, kernel.FDFlags{ + err := t.FDTable().SetFlagsVFS2(t, fd, kernel.FDFlags{ CloseOnExec: flags&linux.FD_CLOEXEC != 0, }) return 0, nil, err @@ -181,11 +181,11 @@ func Fcntl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall if !hasOwner { return 0, nil, nil } - _, err := t.CopyOut(args[2].Pointer(), &owner) + _, err := owner.CopyOut(t, args[2].Pointer()) return 0, nil, err case linux.F_SETOWN_EX: var owner linux.FOwnerEx - _, err := t.CopyIn(args[2].Pointer(), &owner) + _, err := owner.CopyIn(t, args[2].Pointer()) if err != nil { return 0, nil, err } @@ -286,7 +286,7 @@ func posixLock(t *kernel.Task, args arch.SyscallArguments, file *vfs.FileDescrip // Copy in the lock request. flockAddr := args[2].Pointer() var flock linux.Flock - if _, err := t.CopyIn(flockAddr, &flock); err != nil { + if _, err := flock.CopyIn(t, flockAddr); err != nil { return err } diff --git a/pkg/sentry/syscalls/linux/vfs2/ioctl.go b/pkg/sentry/syscalls/linux/vfs2/ioctl.go index 38778a388..2806c3f6f 100644 --- a/pkg/sentry/syscalls/linux/vfs2/ioctl.go +++ b/pkg/sentry/syscalls/linux/vfs2/ioctl.go @@ -16,6 +16,7 @@ package vfs2 import ( "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/syserror" @@ -34,20 +35,20 @@ func Ioctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall // Handle ioctls that apply to all FDs. switch args[1].Int() { case linux.FIONCLEX: - t.FDTable().SetFlagsVFS2(fd, kernel.FDFlags{ + t.FDTable().SetFlagsVFS2(t, fd, kernel.FDFlags{ CloseOnExec: false, }) return 0, nil, nil case linux.FIOCLEX: - t.FDTable().SetFlagsVFS2(fd, kernel.FDFlags{ + t.FDTable().SetFlagsVFS2(t, fd, kernel.FDFlags{ CloseOnExec: true, }) return 0, nil, nil case linux.FIONBIO: var set int32 - if _, err := t.CopyIn(args[2].Pointer(), &set); err != nil { + if _, err := primitive.CopyInt32In(t, args[2].Pointer(), &set); err != nil { return 0, nil, err } flags := file.StatusFlags() @@ -60,7 +61,7 @@ func Ioctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall case linux.FIOASYNC: var set int32 - if _, err := t.CopyIn(args[2].Pointer(), &set); err != nil { + if _, err := primitive.CopyInt32In(t, args[2].Pointer(), &set); err != nil { return 0, nil, err } flags := file.StatusFlags() @@ -82,12 +83,12 @@ func Ioctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall who = owner.PID } } - _, err := t.CopyOut(args[2].Pointer(), &who) + _, err := primitive.CopyInt32Out(t, args[2].Pointer(), who) return 0, nil, err case linux.FIOSETOWN, linux.SIOCSPGRP: var who int32 - if _, err := t.CopyIn(args[2].Pointer(), &who); err != nil { + if _, err := primitive.CopyInt32In(t, args[2].Pointer(), &who); err != nil { return 0, nil, err } ownerType := int32(linux.F_OWNER_PID) diff --git a/pkg/sentry/syscalls/linux/vfs2/mmap.go b/pkg/sentry/syscalls/linux/vfs2/mmap.go index dc05c2994..9d9dbf775 100644 --- a/pkg/sentry/syscalls/linux/vfs2/mmap.go +++ b/pkg/sentry/syscalls/linux/vfs2/mmap.go @@ -17,6 +17,7 @@ package vfs2 import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/sentry/arch" + "gvisor.dev/gvisor/pkg/sentry/fsimpl/tmpfs" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/memmap" "gvisor.dev/gvisor/pkg/syserror" @@ -85,6 +86,17 @@ func Mmap(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallC if err := file.ConfigureMMap(t, &opts); err != nil { return 0, nil, err } + } else if shared { + // Back shared anonymous mappings with an anonymous tmpfs file. + opts.Offset = 0 + file, err := tmpfs.NewZeroFile(t, t.Credentials(), t.Kernel().ShmMount(), opts.Length) + if err != nil { + return 0, nil, err + } + defer file.DecRef(t) + if err := file.ConfigureMMap(t, &opts); err != nil { + return 0, nil, err + } } rv, err := t.MemoryManager().MMap(t, opts) diff --git a/pkg/sentry/syscalls/linux/vfs2/pipe.go b/pkg/sentry/syscalls/linux/vfs2/pipe.go index 9b4848d9e..ee38fdca0 100644 --- a/pkg/sentry/syscalls/linux/vfs2/pipe.go +++ b/pkg/sentry/syscalls/linux/vfs2/pipe.go @@ -16,6 +16,7 @@ package vfs2 import ( "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/fsimpl/pipefs" "gvisor.dev/gvisor/pkg/sentry/kernel" @@ -51,9 +52,9 @@ func pipe2(t *kernel.Task, addr usermem.Addr, flags int32) error { if err != nil { return err } - if _, err := t.CopyOut(addr, fds); err != nil { + if _, err := primitive.CopyInt32SliceOut(t, addr, fds); err != nil { for _, fd := range fds { - if _, file := t.FDTable().Remove(fd); file != nil { + if _, file := t.FDTable().Remove(t, fd); file != nil { file.DecRef(t) } } diff --git a/pkg/sentry/syscalls/linux/vfs2/poll.go b/pkg/sentry/syscalls/linux/vfs2/poll.go index 79ad64039..c22e4ce54 100644 --- a/pkg/sentry/syscalls/linux/vfs2/poll.go +++ b/pkg/sentry/syscalls/linux/vfs2/poll.go @@ -165,7 +165,7 @@ func copyInPollFDs(t *kernel.Task, addr usermem.Addr, nfds uint) ([]linux.PollFD pfd := make([]linux.PollFD, nfds) if nfds > 0 { - if _, err := t.CopyIn(addr, &pfd); err != nil { + if _, err := linux.CopyPollFDSliceIn(t, addr, pfd); err != nil { return nil, err } } @@ -192,7 +192,7 @@ func doPoll(t *kernel.Task, addr usermem.Addr, nfds uint, timeout time.Duration) // The poll entries are copied out regardless of whether // any are set or not. This aligns with the Linux behavior. if nfds > 0 && err == nil { - if _, err := t.CopyOut(addr, pfd); err != nil { + if _, err := linux.CopyPollFDSliceOut(t, addr, pfd); err != nil { return remainingTimeout, 0, err } } @@ -205,7 +205,7 @@ func CopyInFDSet(t *kernel.Task, addr usermem.Addr, nBytes, nBitsInLastPartialBy set := make([]byte, nBytes) if addr != 0 { - if _, err := t.CopyIn(addr, &set); err != nil { + if _, err := t.CopyInBytes(addr, set); err != nil { return nil, err } // If we only use part of the last byte, mask out the extraneous bits. @@ -332,19 +332,19 @@ func doSelect(t *kernel.Task, nfds int, readFDs, writeFDs, exceptFDs usermem.Add // Copy updated vectors back. if readFDs != 0 { - if _, err := t.CopyOut(readFDs, r); err != nil { + if _, err := t.CopyOutBytes(readFDs, r); err != nil { return 0, err } } if writeFDs != 0 { - if _, err := t.CopyOut(writeFDs, w); err != nil { + if _, err := t.CopyOutBytes(writeFDs, w); err != nil { return 0, err } } if exceptFDs != 0 { - if _, err := t.CopyOut(exceptFDs, e); err != nil { + if _, err := t.CopyOutBytes(exceptFDs, e); err != nil { return 0, err } } @@ -497,6 +497,12 @@ func Select(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal return n, nil, err } +// +marshal +type sigSetWithSize struct { + sigsetAddr uint64 + sizeofSigset uint64 +} + // Pselect implements linux syscall pselect(2). func Pselect(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { nfds := int(args[0].Int()) // select(2) uses an int. @@ -538,12 +544,6 @@ func Pselect(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysca return n, nil, err } -// +marshal -type sigSetWithSize struct { - sigsetAddr uint64 - sizeofSigset uint64 -} - // copyTimespecInToDuration copies a Timespec from the untrusted app range, // validates it and converts it to a Duration. // diff --git a/pkg/sentry/syscalls/linux/vfs2/setstat.go b/pkg/sentry/syscalls/linux/vfs2/setstat.go index 5e6eb13ba..1ee37e5a8 100644 --- a/pkg/sentry/syscalls/linux/vfs2/setstat.go +++ b/pkg/sentry/syscalls/linux/vfs2/setstat.go @@ -346,7 +346,7 @@ func populateSetStatOptionsForUtimes(t *kernel.Task, timesAddr usermem.Addr, opt return nil } var times [2]linux.Timeval - if _, err := t.CopyIn(timesAddr, ×); err != nil { + if _, err := linux.CopyTimevalSliceIn(t, timesAddr, times[:]); err != nil { return err } if times[0].Usec < 0 || times[0].Usec > 999999 || times[1].Usec < 0 || times[1].Usec > 999999 { @@ -410,7 +410,7 @@ func populateSetStatOptionsForUtimens(t *kernel.Task, timesAddr usermem.Addr, op return nil } var times [2]linux.Timespec - if _, err := t.CopyIn(timesAddr, ×); err != nil { + if _, err := linux.CopyTimespecSliceIn(t, timesAddr, times[:]); err != nil { return err } if times[0].Nsec != linux.UTIME_OMIT { diff --git a/pkg/sentry/syscalls/linux/vfs2/socket.go b/pkg/sentry/syscalls/linux/vfs2/socket.go index a5032657a..bfae6b7e9 100644 --- a/pkg/sentry/syscalls/linux/vfs2/socket.go +++ b/pkg/sentry/syscalls/linux/vfs2/socket.go @@ -19,6 +19,8 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/binary" + "gvisor.dev/gvisor/pkg/marshal" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/kernel" ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time" @@ -30,8 +32,6 @@ import ( "gvisor.dev/gvisor/pkg/syserr" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/usermem" - "gvisor.dev/gvisor/tools/go_marshal/marshal" - "gvisor.dev/gvisor/tools/go_marshal/primitive" ) // minListenBacklog is the minimum reasonable backlog for listening sockets. @@ -66,10 +66,10 @@ const flagsOffset = 48 const sizeOfInt32 = 4 // messageHeader64Len is the length of a MessageHeader64 struct. -var messageHeader64Len = uint64(binary.Size(MessageHeader64{})) +var messageHeader64Len = uint64((*MessageHeader64)(nil).SizeBytes()) // multipleMessageHeader64Len is the length of a multipeMessageHeader64 struct. -var multipleMessageHeader64Len = uint64(binary.Size(multipleMessageHeader64{})) +var multipleMessageHeader64Len = uint64((*multipleMessageHeader64)(nil).SizeBytes()) // baseRecvFlags are the flags that are accepted across recvmsg(2), // recvmmsg(2), and recvfrom(2). @@ -77,6 +77,8 @@ const baseRecvFlags = linux.MSG_OOB | linux.MSG_DONTROUTE | linux.MSG_DONTWAIT | // MessageHeader64 is the 64-bit representation of the msghdr struct used in // the recvmsg and sendmsg syscalls. +// +// +marshal type MessageHeader64 struct { // Name is the optional pointer to a network address buffer. Name uint64 @@ -105,30 +107,14 @@ type MessageHeader64 struct { // multipleMessageHeader64 is the 64-bit representation of the mmsghdr struct used in // the recvmmsg and sendmmsg syscalls. +// +// +marshal type multipleMessageHeader64 struct { msgHdr MessageHeader64 msgLen uint32 _ int32 } -// CopyInMessageHeader64 copies a message header from user to kernel memory. -func CopyInMessageHeader64(t *kernel.Task, addr usermem.Addr, msg *MessageHeader64) error { - b := t.CopyScratchBuffer(52) - if _, err := t.CopyInBytes(addr, b); err != nil { - return err - } - - msg.Name = usermem.ByteOrder.Uint64(b[0:]) - msg.NameLen = usermem.ByteOrder.Uint32(b[8:]) - msg.Iov = usermem.ByteOrder.Uint64(b[16:]) - msg.IovLen = usermem.ByteOrder.Uint64(b[24:]) - msg.Control = usermem.ByteOrder.Uint64(b[32:]) - msg.ControlLen = usermem.ByteOrder.Uint64(b[40:]) - msg.Flags = int32(usermem.ByteOrder.Uint32(b[48:])) - - return nil -} - // CaptureAddress allocates memory for and copies a socket address structure // from the untrusted address space range. func CaptureAddress(t *kernel.Task, addr usermem.Addr, addrlen uint32) ([]byte, error) { @@ -147,10 +133,10 @@ func CaptureAddress(t *kernel.Task, addr usermem.Addr, addrlen uint32) ([]byte, // writeAddress writes a sockaddr structure and its length to an output buffer // in the unstrusted address space range. If the address is bigger than the // buffer, it is truncated. -func writeAddress(t *kernel.Task, addr interface{}, addrLen uint32, addrPtr usermem.Addr, addrLenPtr usermem.Addr) error { +func writeAddress(t *kernel.Task, addr linux.SockAddr, addrLen uint32, addrPtr usermem.Addr, addrLenPtr usermem.Addr) error { // Get the buffer length. var bufLen uint32 - if _, err := t.CopyIn(addrLenPtr, &bufLen); err != nil { + if _, err := primitive.CopyUint32In(t, addrLenPtr, &bufLen); err != nil { return err } @@ -159,7 +145,7 @@ func writeAddress(t *kernel.Task, addr interface{}, addrLen uint32, addrPtr user } // Write the length unconditionally. - if _, err := t.CopyOut(addrLenPtr, addrLen); err != nil { + if _, err := primitive.CopyUint32Out(t, addrLenPtr, addrLen); err != nil { return err } @@ -172,7 +158,8 @@ func writeAddress(t *kernel.Task, addr interface{}, addrLen uint32, addrPtr user } // Copy as much of the address as will fit in the buffer. - encodedAddr := binary.Marshal(nil, usermem.ByteOrder, addr) + encodedAddr := t.CopyScratchBuffer(addr.SizeBytes()) + addr.MarshalUnsafe(encodedAddr) if bufLen > uint32(len(encodedAddr)) { bufLen = uint32(len(encodedAddr)) } @@ -250,9 +237,9 @@ func SocketPair(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sy return 0, nil, err } - if _, err := t.CopyOut(addr, fds); err != nil { + if _, err := primitive.CopyInt32SliceOut(t, addr, fds); err != nil { for _, fd := range fds { - if _, file := t.FDTable().Remove(fd); file != nil { + if _, file := t.FDTable().Remove(t, fd); file != nil { file.DecRef(t) } } @@ -459,8 +446,8 @@ func GetSockOpt(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sy } // Read the length. Reject negative values. - optLen := int32(0) - if _, err := t.CopyIn(optLenAddr, &optLen); err != nil { + var optLen int32 + if _, err := primitive.CopyInt32In(t, optLenAddr, &optLen); err != nil { return 0, nil, err } if optLen < 0 { @@ -474,7 +461,7 @@ func GetSockOpt(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sy } vLen := int32(binary.Size(v)) - if _, err := t.CopyOut(optLenAddr, vLen); err != nil { + if _, err := primitive.CopyInt32Out(t, optLenAddr, vLen); err != nil { return 0, nil, err } @@ -736,7 +723,7 @@ func RecvMMsg(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc if !ok { return 0, nil, syserror.EFAULT } - if _, err = t.CopyOut(lp, uint32(n)); err != nil { + if _, err = primitive.CopyUint32Out(t, lp, uint32(n)); err != nil { break } count++ @@ -751,7 +738,7 @@ func RecvMMsg(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc func recvSingleMsg(t *kernel.Task, s socket.SocketVFS2, msgPtr usermem.Addr, flags int32, haveDeadline bool, deadline ktime.Time) (uintptr, error) { // Capture the message header and io vectors. var msg MessageHeader64 - if err := CopyInMessageHeader64(t, msgPtr, &msg); err != nil { + if _, err := msg.CopyIn(t, msgPtr); err != nil { return 0, err } @@ -783,7 +770,7 @@ func recvSingleMsg(t *kernel.Task, s socket.SocketVFS2, msgPtr usermem.Addr, fla if int(msg.Flags) != mflags { // Copy out the flags to the caller. - if _, err := t.CopyOut(msgPtr+flagsOffset, int32(mflags)); err != nil { + if _, err := primitive.CopyInt32Out(t, msgPtr+flagsOffset, int32(mflags)); err != nil { return 0, err } } @@ -820,17 +807,17 @@ func recvSingleMsg(t *kernel.Task, s socket.SocketVFS2, msgPtr usermem.Addr, fla } // Copy the control data to the caller. - if _, err := t.CopyOut(msgPtr+controlLenOffset, uint64(len(controlData))); err != nil { + if _, err := primitive.CopyUint64Out(t, msgPtr+controlLenOffset, uint64(len(controlData))); err != nil { return 0, err } if len(controlData) > 0 { - if _, err := t.CopyOut(usermem.Addr(msg.Control), controlData); err != nil { + if _, err := t.CopyOutBytes(usermem.Addr(msg.Control), controlData); err != nil { return 0, err } } // Copy out the flags to the caller. - if _, err := t.CopyOut(msgPtr+flagsOffset, int32(mflags)); err != nil { + if _, err := primitive.CopyInt32Out(t, msgPtr+flagsOffset, int32(mflags)); err != nil { return 0, err } @@ -999,7 +986,7 @@ func SendMMsg(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc if !ok { return 0, nil, syserror.EFAULT } - if _, err = t.CopyOut(lp, uint32(n)); err != nil { + if _, err = primitive.CopyUint32Out(t, lp, uint32(n)); err != nil { break } count++ @@ -1014,7 +1001,7 @@ func SendMMsg(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc func sendSingleMsg(t *kernel.Task, s socket.SocketVFS2, file *vfs.FileDescription, msgPtr usermem.Addr, flags int32) (uintptr, error) { // Capture the message header. var msg MessageHeader64 - if err := CopyInMessageHeader64(t, msgPtr, &msg); err != nil { + if _, err := msg.CopyIn(t, msgPtr); err != nil { return 0, err } @@ -1025,7 +1012,7 @@ func sendSingleMsg(t *kernel.Task, s socket.SocketVFS2, file *vfs.FileDescriptio return 0, syserror.ENOBUFS } controlData = make([]byte, msg.ControlLen) - if _, err := t.CopyIn(usermem.Addr(msg.Control), &controlData); err != nil { + if _, err := t.CopyInBytes(usermem.Addr(msg.Control), controlData); err != nil { return 0, err } } diff --git a/pkg/sentry/syscalls/linux/vfs2/splice.go b/pkg/sentry/syscalls/linux/vfs2/splice.go index 68ce94778..bf5c1171f 100644 --- a/pkg/sentry/syscalls/linux/vfs2/splice.go +++ b/pkg/sentry/syscalls/linux/vfs2/splice.go @@ -18,9 +18,12 @@ import ( "io" "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/log" + "gvisor.dev/gvisor/pkg/marshal/primitive" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/kernel/pipe" + slinux "gvisor.dev/gvisor/pkg/sentry/syscalls/linux" "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/usermem" @@ -88,7 +91,7 @@ func Splice(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal if inFile.Options().DenyPRead { return 0, nil, syserror.EINVAL } - if _, err := t.CopyIn(inOffsetPtr, &inOffset); err != nil { + if _, err := primitive.CopyInt64In(t, inOffsetPtr, &inOffset); err != nil { return 0, nil, err } if inOffset < 0 { @@ -103,7 +106,7 @@ func Splice(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal if outFile.Options().DenyPWrite { return 0, nil, syserror.EINVAL } - if _, err := t.CopyIn(outOffsetPtr, &outOffset); err != nil { + if _, err := primitive.CopyInt64In(t, outOffsetPtr, &outOffset); err != nil { return 0, nil, err } if outOffset < 0 { @@ -144,11 +147,6 @@ func Splice(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal panic("at least one end of splice must be a pipe") } - if n == 0 && err == io.EOF { - // We reached the end of the file. Eat the error and exit the loop. - err = nil - break - } if n != 0 || err != syserror.ErrWouldBlock || nonBlock { break } @@ -159,25 +157,26 @@ func Splice(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal // Copy updated offsets out. if inOffsetPtr != 0 { - if _, err := t.CopyOut(inOffsetPtr, &inOffset); err != nil { + if _, err := primitive.CopyInt64Out(t, inOffsetPtr, inOffset); err != nil { return 0, nil, err } } if outOffsetPtr != 0 { - if _, err := t.CopyOut(outOffsetPtr, &outOffset); err != nil { + if _, err := primitive.CopyInt64Out(t, outOffsetPtr, outOffset); err != nil { return 0, nil, err } } - if n == 0 { - return 0, nil, err + if n != 0 { + // On Linux, inotify behavior is not very consistent with splice(2). We try + // our best to emulate Linux for very basic calls to splice, where for some + // reason, events are generated for output files, but not input files. + outFile.Dentry().InotifyWithParent(t, linux.IN_MODIFY, 0, vfs.PathEvent) } - // On Linux, inotify behavior is not very consistent with splice(2). We try - // our best to emulate Linux for very basic calls to splice, where for some - // reason, events are generated for output files, but not input files. - outFile.Dentry().InotifyWithParent(t, linux.IN_MODIFY, 0, vfs.PathEvent) - return uintptr(n), nil, nil + // We can only pass a single file to handleIOError, so pick inFile arbitrarily. + // This is used only for debugging purposes. + return uintptr(n), nil, slinux.HandleIOErrorVFS2(t, n != 0, err, syserror.ERESTARTSYS, "splice", outFile) } // Tee implements Linux syscall tee(2). @@ -249,11 +248,20 @@ func Tee(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallCo break } } - if n == 0 { - return 0, nil, err + + if n != 0 { + outFile.Dentry().InotifyWithParent(t, linux.IN_MODIFY, 0, vfs.PathEvent) + + // If a partial write is completed, the error is dropped. Log it here. + if err != nil && err != io.EOF && err != syserror.ErrWouldBlock { + log.Debugf("tee completed a partial write with error: %v", err) + err = nil + } } - outFile.Dentry().InotifyWithParent(t, linux.IN_MODIFY, 0, vfs.PathEvent) - return uintptr(n), nil, nil + + // We can only pass a single file to handleIOError, so pick inFile arbitrarily. + // This is used only for debugging purposes. + return uintptr(n), nil, slinux.HandleIOErrorVFS2(t, n != 0, err, syserror.ERESTARTSYS, "tee", inFile) } // Sendfile implements linux system call sendfile(2). @@ -302,9 +310,12 @@ func Sendfile(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc if inFile.Options().DenyPRead { return 0, nil, syserror.ESPIPE } - if _, err := t.CopyIn(offsetAddr, &offset); err != nil { + var offsetP primitive.Int64 + if _, err := offsetP.CopyIn(t, offsetAddr); err != nil { return 0, nil, err } + offset = int64(offsetP) + if offset < 0 { return 0, nil, syserror.EINVAL } @@ -343,11 +354,6 @@ func Sendfile(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc for n < count { var spliceN int64 spliceN, err = outPipeFD.SpliceFromNonPipe(t, inFile, offset, count) - if spliceN == 0 && err == io.EOF { - // We reached the end of the file. Eat the error and exit the loop. - err = nil - break - } if offset != -1 { offset += spliceN } @@ -370,13 +376,6 @@ func Sendfile(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc } else { readN, err = inFile.Read(t, usermem.BytesIOSequence(buf), vfs.ReadOptions{}) } - if readN == 0 && err != nil { - if err == io.EOF { - // We reached the end of the file. Eat the error before exiting the loop. - err = nil - } - break - } n += readN // Write all of the bytes that we read. This may need @@ -390,16 +389,21 @@ func Sendfile(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc err = dw.waitForOut(t) } if err != nil { - // We didn't complete the write. Only - // report the bytes that were actually - // written, and rewind the offset. + // We didn't complete the write. Only report the bytes that were actually + // written, and rewind offsets as needed. notWritten := int64(len(wbuf)) n -= notWritten - if offset != -1 { - // TODO(gvisor.dev/issue/3779): The inFile offset will be incorrect if we - // roll back, because it has already been advanced by the full amount. - // Merely seeking on inFile does not work, because there may be concurrent - // file operations. + if offset == -1 { + // We modified the offset of the input file itself during the read + // operation. Rewind it. + if _, seekErr := inFile.Seek(t, -notWritten, linux.SEEK_CUR); seekErr != nil { + // Log the error but don't return it, since the write has already + // completed successfully. + log.Warningf("failed to roll back input file offset: %v", seekErr) + } + } else { + // The sendfile call was provided an offset parameter that should be + // adjusted to reflect the number of bytes sent. Rewind it. offset -= notWritten } break @@ -416,18 +420,26 @@ func Sendfile(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc if offsetAddr != 0 { // Copy out the new offset. - if _, err := t.CopyOut(offsetAddr, offset); err != nil { + offsetP := primitive.Uint64(offset) + if _, err := offsetP.CopyOut(t, offsetAddr); err != nil { return 0, nil, err } } - if n == 0 { - return 0, nil, err + if n != 0 { + inFile.Dentry().InotifyWithParent(t, linux.IN_ACCESS, 0, vfs.PathEvent) + outFile.Dentry().InotifyWithParent(t, linux.IN_MODIFY, 0, vfs.PathEvent) + + if err != nil && err != io.EOF && err != syserror.ErrWouldBlock { + // If a partial write is completed, the error is dropped. Log it here. + log.Debugf("sendfile completed a partial write with error: %v", err) + err = nil + } } - inFile.Dentry().InotifyWithParent(t, linux.IN_ACCESS, 0, vfs.PathEvent) - outFile.Dentry().InotifyWithParent(t, linux.IN_MODIFY, 0, vfs.PathEvent) - return uintptr(n), nil, nil + // We can only pass a single file to handleIOError, so pick inFile arbitrarily. + // This is used only for debugging purposes. + return uintptr(n), nil, slinux.HandleIOErrorVFS2(t, n != 0, err, syserror.ERESTARTSYS, "sendfile", inFile) } // dualWaiter is used to wait on one or both vfs.FileDescriptions. It is not diff --git a/pkg/sentry/syscalls/linux/vfs2/timerfd.go b/pkg/sentry/syscalls/linux/vfs2/timerfd.go index 7a26890ef..250870c03 100644 --- a/pkg/sentry/syscalls/linux/vfs2/timerfd.go +++ b/pkg/sentry/syscalls/linux/vfs2/timerfd.go @@ -87,7 +87,7 @@ func TimerfdSettime(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kerne } var newVal linux.Itimerspec - if _, err := t.CopyIn(newValAddr, &newVal); err != nil { + if _, err := newVal.CopyIn(t, newValAddr); err != nil { return 0, nil, err } newS, err := ktime.SettingFromItimerspec(newVal, flags&linux.TFD_TIMER_ABSTIME != 0, tfd.Clock()) @@ -97,7 +97,7 @@ func TimerfdSettime(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kerne tm, oldS := tfd.SetTime(newS) if oldValAddr != 0 { oldVal := ktime.ItimerspecFromSetting(tm, oldS) - if _, err := t.CopyOut(oldValAddr, &oldVal); err != nil { + if _, err := oldVal.CopyOut(t, oldValAddr); err != nil { return 0, nil, err } } @@ -122,6 +122,6 @@ func TimerfdGettime(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kerne tm, s := tfd.GetTime() curVal := ktime.ItimerspecFromSetting(tm, s) - _, err := t.CopyOut(curValAddr, &curVal) + _, err := curVal.CopyOut(t, curValAddr) return 0, nil, err } diff --git a/pkg/sentry/syscalls/linux/vfs2/vfs2.go b/pkg/sentry/syscalls/linux/vfs2/vfs2.go index c576d9475..0df3bd449 100644 --- a/pkg/sentry/syscalls/linux/vfs2/vfs2.go +++ b/pkg/sentry/syscalls/linux/vfs2/vfs2.go @@ -93,16 +93,16 @@ func Override() { s.Table[165] = syscalls.Supported("mount", Mount) s.Table[166] = syscalls.Supported("umount2", Umount2) s.Table[187] = syscalls.Supported("readahead", Readahead) - s.Table[188] = syscalls.Supported("setxattr", Setxattr) + s.Table[188] = syscalls.Supported("setxattr", SetXattr) s.Table[189] = syscalls.Supported("lsetxattr", Lsetxattr) s.Table[190] = syscalls.Supported("fsetxattr", Fsetxattr) - s.Table[191] = syscalls.Supported("getxattr", Getxattr) + s.Table[191] = syscalls.Supported("getxattr", GetXattr) s.Table[192] = syscalls.Supported("lgetxattr", Lgetxattr) s.Table[193] = syscalls.Supported("fgetxattr", Fgetxattr) - s.Table[194] = syscalls.Supported("listxattr", Listxattr) + s.Table[194] = syscalls.Supported("listxattr", ListXattr) s.Table[195] = syscalls.Supported("llistxattr", Llistxattr) s.Table[196] = syscalls.Supported("flistxattr", Flistxattr) - s.Table[197] = syscalls.Supported("removexattr", Removexattr) + s.Table[197] = syscalls.Supported("removexattr", RemoveXattr) s.Table[198] = syscalls.Supported("lremovexattr", Lremovexattr) s.Table[199] = syscalls.Supported("fremovexattr", Fremovexattr) s.Table[209] = syscalls.PartiallySupported("io_submit", IoSubmit, "Generally supported with exceptions. User ring optimizations are not implemented.", []string{"gvisor.dev/issue/204"}) @@ -163,16 +163,16 @@ func Override() { // Override ARM64. s = linux.ARM64 - s.Table[5] = syscalls.Supported("setxattr", Setxattr) + s.Table[5] = syscalls.Supported("setxattr", SetXattr) s.Table[6] = syscalls.Supported("lsetxattr", Lsetxattr) s.Table[7] = syscalls.Supported("fsetxattr", Fsetxattr) - s.Table[8] = syscalls.Supported("getxattr", Getxattr) + s.Table[8] = syscalls.Supported("getxattr", GetXattr) s.Table[9] = syscalls.Supported("lgetxattr", Lgetxattr) s.Table[10] = syscalls.Supported("fgetxattr", Fgetxattr) - s.Table[11] = syscalls.Supported("listxattr", Listxattr) + s.Table[11] = syscalls.Supported("listxattr", ListXattr) s.Table[12] = syscalls.Supported("llistxattr", Llistxattr) s.Table[13] = syscalls.Supported("flistxattr", Flistxattr) - s.Table[14] = syscalls.Supported("removexattr", Removexattr) + s.Table[14] = syscalls.Supported("removexattr", RemoveXattr) s.Table[15] = syscalls.Supported("lremovexattr", Lremovexattr) s.Table[16] = syscalls.Supported("fremovexattr", Fremovexattr) s.Table[17] = syscalls.Supported("getcwd", Getcwd) diff --git a/pkg/sentry/syscalls/linux/vfs2/xattr.go b/pkg/sentry/syscalls/linux/vfs2/xattr.go index ef99246ed..e05723ef9 100644 --- a/pkg/sentry/syscalls/linux/vfs2/xattr.go +++ b/pkg/sentry/syscalls/linux/vfs2/xattr.go @@ -26,8 +26,8 @@ import ( "gvisor.dev/gvisor/pkg/usermem" ) -// Listxattr implements Linux syscall listxattr(2). -func Listxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { +// ListXattr implements Linux syscall listxattr(2). +func ListXattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { return listxattr(t, args, followFinalSymlink) } @@ -51,7 +51,7 @@ func listxattr(t *kernel.Task, args arch.SyscallArguments, shouldFollowFinalSyml } defer tpop.Release(t) - names, err := t.Kernel().VFS().ListxattrAt(t, t.Credentials(), &tpop.pop, uint64(size)) + names, err := t.Kernel().VFS().ListXattrAt(t, t.Credentials(), &tpop.pop, uint64(size)) if err != nil { return 0, nil, err } @@ -74,7 +74,7 @@ func Flistxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sy } defer file.DecRef(t) - names, err := file.Listxattr(t, uint64(size)) + names, err := file.ListXattr(t, uint64(size)) if err != nil { return 0, nil, err } @@ -85,8 +85,8 @@ func Flistxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sy return uintptr(n), nil, nil } -// Getxattr implements Linux syscall getxattr(2). -func Getxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { +// GetXattr implements Linux syscall getxattr(2). +func GetXattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { return getxattr(t, args, followFinalSymlink) } @@ -116,7 +116,7 @@ func getxattr(t *kernel.Task, args arch.SyscallArguments, shouldFollowFinalSymli return 0, nil, err } - value, err := t.Kernel().VFS().GetxattrAt(t, t.Credentials(), &tpop.pop, &vfs.GetxattrOptions{ + value, err := t.Kernel().VFS().GetXattrAt(t, t.Credentials(), &tpop.pop, &vfs.GetXattrOptions{ Name: name, Size: uint64(size), }) @@ -148,7 +148,7 @@ func Fgetxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sys return 0, nil, err } - value, err := file.Getxattr(t, &vfs.GetxattrOptions{Name: name, Size: uint64(size)}) + value, err := file.GetXattr(t, &vfs.GetXattrOptions{Name: name, Size: uint64(size)}) if err != nil { return 0, nil, err } @@ -159,8 +159,8 @@ func Fgetxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sys return uintptr(n), nil, nil } -// Setxattr implements Linux syscall setxattr(2). -func Setxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { +// SetXattr implements Linux syscall setxattr(2). +func SetXattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { return 0, nil, setxattr(t, args, followFinalSymlink) } @@ -199,7 +199,7 @@ func setxattr(t *kernel.Task, args arch.SyscallArguments, shouldFollowFinalSymli return err } - return t.Kernel().VFS().SetxattrAt(t, t.Credentials(), &tpop.pop, &vfs.SetxattrOptions{ + return t.Kernel().VFS().SetXattrAt(t, t.Credentials(), &tpop.pop, &vfs.SetXattrOptions{ Name: name, Value: value, Flags: uint32(flags), @@ -233,15 +233,15 @@ func Fsetxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sys return 0, nil, err } - return 0, nil, file.Setxattr(t, &vfs.SetxattrOptions{ + return 0, nil, file.SetXattr(t, &vfs.SetXattrOptions{ Name: name, Value: value, Flags: uint32(flags), }) } -// Removexattr implements Linux syscall removexattr(2). -func Removexattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { +// RemoveXattr implements Linux syscall removexattr(2). +func RemoveXattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { return 0, nil, removexattr(t, args, followFinalSymlink) } @@ -269,7 +269,7 @@ func removexattr(t *kernel.Task, args arch.SyscallArguments, shouldFollowFinalSy return err } - return t.Kernel().VFS().RemovexattrAt(t, t.Credentials(), &tpop.pop, name) + return t.Kernel().VFS().RemoveXattrAt(t, t.Credentials(), &tpop.pop, name) } // Fremovexattr implements Linux syscall fremovexattr(2). @@ -288,7 +288,7 @@ func Fremovexattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel. return 0, nil, err } - return 0, nil, file.Removexattr(t, name) + return 0, nil, file.RemoveXattr(t, name) } func copyInXattrName(t *kernel.Task, nameAddr usermem.Addr) (string, error) { diff --git a/pkg/sentry/vfs/anonfs.go b/pkg/sentry/vfs/anonfs.go index 5a0e3e6b5..bdfd3ca8f 100644 --- a/pkg/sentry/vfs/anonfs.go +++ b/pkg/sentry/vfs/anonfs.go @@ -52,6 +52,8 @@ const ( ) // anonFilesystemType implements FilesystemType. +// +// +stateify savable type anonFilesystemType struct{} // GetFilesystem implements FilesystemType.GetFilesystem. @@ -69,12 +71,15 @@ func (anonFilesystemType) Name() string { // // Since all Dentries in anonFilesystem are non-directories, all FilesystemImpl // methods that would require an anonDentry to be a directory return ENOTDIR. +// +// +stateify savable type anonFilesystem struct { vfsfs Filesystem devMinor uint32 } +// +stateify savable type anonDentry struct { vfsd Dentry @@ -245,32 +250,32 @@ func (fs *anonFilesystem) BoundEndpointAt(ctx context.Context, rp *ResolvingPath return nil, syserror.ECONNREFUSED } -// ListxattrAt implements FilesystemImpl.ListxattrAt. -func (fs *anonFilesystem) ListxattrAt(ctx context.Context, rp *ResolvingPath, size uint64) ([]string, error) { +// ListXattrAt implements FilesystemImpl.ListXattrAt. +func (fs *anonFilesystem) ListXattrAt(ctx context.Context, rp *ResolvingPath, size uint64) ([]string, error) { if !rp.Done() { return nil, syserror.ENOTDIR } return nil, nil } -// GetxattrAt implements FilesystemImpl.GetxattrAt. -func (fs *anonFilesystem) GetxattrAt(ctx context.Context, rp *ResolvingPath, opts GetxattrOptions) (string, error) { +// GetXattrAt implements FilesystemImpl.GetXattrAt. +func (fs *anonFilesystem) GetXattrAt(ctx context.Context, rp *ResolvingPath, opts GetXattrOptions) (string, error) { if !rp.Done() { return "", syserror.ENOTDIR } return "", syserror.ENOTSUP } -// SetxattrAt implements FilesystemImpl.SetxattrAt. -func (fs *anonFilesystem) SetxattrAt(ctx context.Context, rp *ResolvingPath, opts SetxattrOptions) error { +// SetXattrAt implements FilesystemImpl.SetXattrAt. +func (fs *anonFilesystem) SetXattrAt(ctx context.Context, rp *ResolvingPath, opts SetXattrOptions) error { if !rp.Done() { return syserror.ENOTDIR } return syserror.EPERM } -// RemovexattrAt implements FilesystemImpl.RemovexattrAt. -func (fs *anonFilesystem) RemovexattrAt(ctx context.Context, rp *ResolvingPath, name string) error { +// RemoveXattrAt implements FilesystemImpl.RemoveXattrAt. +func (fs *anonFilesystem) RemoveXattrAt(ctx context.Context, rp *ResolvingPath, name string) error { if !rp.Done() { return syserror.ENOTDIR } diff --git a/pkg/sentry/vfs/dentry.go b/pkg/sentry/vfs/dentry.go index a69a5b2f1..320ab7ce1 100644 --- a/pkg/sentry/vfs/dentry.go +++ b/pkg/sentry/vfs/dentry.go @@ -89,6 +89,8 @@ func (d *Dentry) Impl() DentryImpl { // DentryImpl contains implementation details for a Dentry. Implementations of // DentryImpl should contain their associated Dentry by value as their first // field. +// +// +stateify savable type DentryImpl interface { // IncRef increments the Dentry's reference count. A Dentry with a non-zero // reference count must remain coherent with the state of the filesystem. diff --git a/pkg/sentry/vfs/device.go b/pkg/sentry/vfs/device.go index 1e9dffc8f..dde2ad79b 100644 --- a/pkg/sentry/vfs/device.go +++ b/pkg/sentry/vfs/device.go @@ -22,6 +22,8 @@ import ( ) // DeviceKind indicates whether a device is a block or character device. +// +// +stateify savable type DeviceKind uint32 const ( @@ -44,6 +46,7 @@ func (kind DeviceKind) String() string { } } +// +stateify savable type devTuple struct { kind DeviceKind major uint32 diff --git a/pkg/sentry/vfs/epoll.go b/pkg/sentry/vfs/epoll.go index 1b5af9f73..8f36c3e3b 100644 --- a/pkg/sentry/vfs/epoll.go +++ b/pkg/sentry/vfs/epoll.go @@ -27,6 +27,8 @@ import ( var epollCycleMu sync.Mutex // EpollInstance represents an epoll instance, as described by epoll(7). +// +// +stateify savable type EpollInstance struct { vfsfd FileDescription FileDescriptionDefaultImpl @@ -38,11 +40,11 @@ type EpollInstance struct { // interest is the set of file descriptors that are registered with the // EpollInstance for monitoring. interest is protected by interestMu. - interestMu sync.Mutex + interestMu sync.Mutex `state:"nosave"` interest map[epollInterestKey]*epollInterest // mu protects fields in registered epollInterests. - mu sync.Mutex + mu sync.Mutex `state:"nosave"` // ready is the set of file descriptors that may be "ready" for I/O. Note // that this must be an ordered list, not a map: "If more than maxevents @@ -55,6 +57,7 @@ type EpollInstance struct { ready epollInterestList } +// +stateify savable type epollInterestKey struct { // file is the registered FileDescription. No reference is held on file; // instead, when the last reference is dropped, FileDescription.DecRef() @@ -67,6 +70,8 @@ type epollInterestKey struct { } // epollInterest represents an EpollInstance's interest in a file descriptor. +// +// +stateify savable type epollInterest struct { // epoll is the owning EpollInstance. epoll is immutable. epoll *EpollInstance @@ -331,11 +336,9 @@ func (ep *EpollInstance) removeLocked(epi *epollInterest) { ep.mu.Unlock() } -// ReadEvents reads up to len(events) ready events into events and returns the -// number of events read. -// -// Preconditions: len(events) != 0. -func (ep *EpollInstance) ReadEvents(events []linux.EpollEvent) int { +// ReadEvents appends up to maxReady events to events and returns the updated +// slice of events. +func (ep *EpollInstance) ReadEvents(events []linux.EpollEvent, maxEvents int) []linux.EpollEvent { i := 0 // Hot path: avoid defer. ep.mu.Lock() @@ -368,16 +371,16 @@ func (ep *EpollInstance) ReadEvents(events []linux.EpollEvent) int { requeue.PushBack(epi) } // Report ievents. - events[i] = linux.EpollEvent{ + events = append(events, linux.EpollEvent{ Events: ievents.ToLinux(), Data: epi.userData, - } + }) i++ - if i == len(events) { + if i == maxEvents { break } } ep.ready.PushBackList(&requeue) ep.mu.Unlock() - return i + return events } diff --git a/pkg/sentry/vfs/file_description.go b/pkg/sentry/vfs/file_description.go index 22a54fa48..1eba0270f 100644 --- a/pkg/sentry/vfs/file_description.go +++ b/pkg/sentry/vfs/file_description.go @@ -37,11 +37,13 @@ import ( // FileDescription methods require that a reference is held. // // FileDescription is analogous to Linux's struct file. +// +// +stateify savable type FileDescription struct { FileDescriptionRefs // flagsMu protects statusFlags and asyncHandler below. - flagsMu sync.Mutex + flagsMu sync.Mutex `state:"nosave"` // statusFlags contains status flags, "initialized by open(2) and possibly // modified by fcntl()" - fcntl(2). statusFlags can be read using atomic @@ -56,7 +58,7 @@ type FileDescription struct { // epolls is the set of epollInterests registered for this FileDescription. // epolls is protected by epollMu. - epollMu sync.Mutex + epollMu sync.Mutex `state:"nosave"` epolls map[*epollInterest]struct{} // vd is the filesystem location at which this FileDescription was opened. @@ -88,6 +90,8 @@ type FileDescription struct { } // FileDescriptionOptions contains options to FileDescription.Init(). +// +// +stateify savable type FileDescriptionOptions struct { // If AllowDirectIO is true, allow O_DIRECT to be set on the file. AllowDirectIO bool @@ -101,7 +105,7 @@ type FileDescriptionOptions struct { // If UseDentryMetadata is true, calls to FileDescription methods that // interact with file and filesystem metadata (Stat, SetStat, StatFS, - // Listxattr, Getxattr, Setxattr, Removexattr) are implemented by calling + // ListXattr, GetXattr, SetXattr, RemoveXattr) are implemented by calling // the corresponding FilesystemImpl methods instead of the corresponding // FileDescriptionImpl methods. // @@ -326,6 +330,9 @@ type FileDescriptionImpl interface { // Allocate grows the file to offset + length bytes. // Only mode == 0 is supported currently. // + // Allocate should return EISDIR on directories, ESPIPE on pipes, and ENODEV on + // other files where it is not supported. + // // Preconditions: The FileDescription was opened for writing. Allocate(ctx context.Context, mode, offset, length uint64) error @@ -420,19 +427,19 @@ type FileDescriptionImpl interface { // Ioctl implements the ioctl(2) syscall. Ioctl(ctx context.Context, uio usermem.IO, args arch.SyscallArguments) (uintptr, error) - // Listxattr returns all extended attribute names for the file. - Listxattr(ctx context.Context, size uint64) ([]string, error) + // ListXattr returns all extended attribute names for the file. + ListXattr(ctx context.Context, size uint64) ([]string, error) - // Getxattr returns the value associated with the given extended attribute + // GetXattr returns the value associated with the given extended attribute // for the file. - Getxattr(ctx context.Context, opts GetxattrOptions) (string, error) + GetXattr(ctx context.Context, opts GetXattrOptions) (string, error) - // Setxattr changes the value associated with the given extended attribute + // SetXattr changes the value associated with the given extended attribute // for the file. - Setxattr(ctx context.Context, opts SetxattrOptions) error + SetXattr(ctx context.Context, opts SetXattrOptions) error - // Removexattr removes the given extended attribute from the file. - Removexattr(ctx context.Context, name string) error + // RemoveXattr removes the given extended attribute from the file. + RemoveXattr(ctx context.Context, name string) error // LockBSD tries to acquire a BSD-style advisory file lock. LockBSD(ctx context.Context, uid lock.UniqueID, t lock.LockType, block lock.Blocker) error @@ -448,6 +455,8 @@ type FileDescriptionImpl interface { } // Dirent holds the information contained in struct linux_dirent64. +// +// +stateify savable type Dirent struct { // Name is the filename. Name string @@ -635,25 +644,25 @@ func (fd *FileDescription) Ioctl(ctx context.Context, uio usermem.IO, args arch. return fd.impl.Ioctl(ctx, uio, args) } -// Listxattr returns all extended attribute names for the file represented by +// ListXattr returns all extended attribute names for the file represented by // fd. // // If the size of the list (including a NUL terminating byte after every entry) // would exceed size, ERANGE may be returned. Note that implementations // are free to ignore size entirely and return without error). In all cases, // if size is 0, the list should be returned without error, regardless of size. -func (fd *FileDescription) Listxattr(ctx context.Context, size uint64) ([]string, error) { +func (fd *FileDescription) ListXattr(ctx context.Context, size uint64) ([]string, error) { if fd.opts.UseDentryMetadata { vfsObj := fd.vd.mount.vfs rp := vfsObj.getResolvingPath(auth.CredentialsFromContext(ctx), &PathOperation{ Root: fd.vd, Start: fd.vd, }) - names, err := fd.vd.mount.fs.impl.ListxattrAt(ctx, rp, size) + names, err := fd.vd.mount.fs.impl.ListXattrAt(ctx, rp, size) vfsObj.putResolvingPath(ctx, rp) return names, err } - names, err := fd.impl.Listxattr(ctx, size) + names, err := fd.impl.ListXattr(ctx, size) if err == syserror.ENOTSUP { // Linux doesn't actually return ENOTSUP in this case; instead, // fs/xattr.c:vfs_listxattr() falls back to allowing the security @@ -664,57 +673,57 @@ func (fd *FileDescription) Listxattr(ctx context.Context, size uint64) ([]string return names, err } -// Getxattr returns the value associated with the given extended attribute for +// GetXattr returns the value associated with the given extended attribute for // the file represented by fd. // // If the size of the return value exceeds opts.Size, ERANGE may be returned // (note that implementations are free to ignore opts.Size entirely and return // without error). In all cases, if opts.Size is 0, the value should be // returned without error, regardless of size. -func (fd *FileDescription) Getxattr(ctx context.Context, opts *GetxattrOptions) (string, error) { +func (fd *FileDescription) GetXattr(ctx context.Context, opts *GetXattrOptions) (string, error) { if fd.opts.UseDentryMetadata { vfsObj := fd.vd.mount.vfs rp := vfsObj.getResolvingPath(auth.CredentialsFromContext(ctx), &PathOperation{ Root: fd.vd, Start: fd.vd, }) - val, err := fd.vd.mount.fs.impl.GetxattrAt(ctx, rp, *opts) + val, err := fd.vd.mount.fs.impl.GetXattrAt(ctx, rp, *opts) vfsObj.putResolvingPath(ctx, rp) return val, err } - return fd.impl.Getxattr(ctx, *opts) + return fd.impl.GetXattr(ctx, *opts) } -// Setxattr changes the value associated with the given extended attribute for +// SetXattr changes the value associated with the given extended attribute for // the file represented by fd. -func (fd *FileDescription) Setxattr(ctx context.Context, opts *SetxattrOptions) error { +func (fd *FileDescription) SetXattr(ctx context.Context, opts *SetXattrOptions) error { if fd.opts.UseDentryMetadata { vfsObj := fd.vd.mount.vfs rp := vfsObj.getResolvingPath(auth.CredentialsFromContext(ctx), &PathOperation{ Root: fd.vd, Start: fd.vd, }) - err := fd.vd.mount.fs.impl.SetxattrAt(ctx, rp, *opts) + err := fd.vd.mount.fs.impl.SetXattrAt(ctx, rp, *opts) vfsObj.putResolvingPath(ctx, rp) return err } - return fd.impl.Setxattr(ctx, *opts) + return fd.impl.SetXattr(ctx, *opts) } -// Removexattr removes the given extended attribute from the file represented +// RemoveXattr removes the given extended attribute from the file represented // by fd. -func (fd *FileDescription) Removexattr(ctx context.Context, name string) error { +func (fd *FileDescription) RemoveXattr(ctx context.Context, name string) error { if fd.opts.UseDentryMetadata { vfsObj := fd.vd.mount.vfs rp := vfsObj.getResolvingPath(auth.CredentialsFromContext(ctx), &PathOperation{ Root: fd.vd, Start: fd.vd, }) - err := fd.vd.mount.fs.impl.RemovexattrAt(ctx, rp, name) + err := fd.vd.mount.fs.impl.RemoveXattrAt(ctx, rp, name) vfsObj.putResolvingPath(ctx, rp) return err } - return fd.impl.Removexattr(ctx, name) + return fd.impl.RemoveXattr(ctx, name) } // SyncFS instructs the filesystem containing fd to execute the semantics of diff --git a/pkg/sentry/vfs/file_description_impl_util.go b/pkg/sentry/vfs/file_description_impl_util.go index 6b8b4ad49..48ca9de44 100644 --- a/pkg/sentry/vfs/file_description_impl_util.go +++ b/pkg/sentry/vfs/file_description_impl_util.go @@ -42,6 +42,8 @@ import ( // FileDescriptionDefaultImpl may be embedded by implementations of // FileDescriptionImpl to obtain implementations of many FileDescriptionImpl // methods with default behavior analogous to Linux's. +// +// +stateify savable type FileDescriptionDefaultImpl struct{} // OnClose implements FileDescriptionImpl.OnClose analogously to @@ -57,7 +59,11 @@ func (FileDescriptionDefaultImpl) StatFS(ctx context.Context) (linux.Statfs, err } // Allocate implements FileDescriptionImpl.Allocate analogously to -// fallocate called on regular file, directory or FIFO in Linux. +// fallocate called on an invalid type of file in Linux. +// +// Note that directories can rely on this implementation even though they +// should technically return EISDIR. Allocate should never be called for a +// directory, because it requires a writable fd. func (FileDescriptionDefaultImpl) Allocate(ctx context.Context, mode, offset, length uint64) error { return syserror.ENODEV } @@ -134,34 +140,36 @@ func (FileDescriptionDefaultImpl) Ioctl(ctx context.Context, uio usermem.IO, arg return 0, syserror.ENOTTY } -// Listxattr implements FileDescriptionImpl.Listxattr analogously to +// ListXattr implements FileDescriptionImpl.ListXattr analogously to // inode_operations::listxattr == NULL in Linux. -func (FileDescriptionDefaultImpl) Listxattr(ctx context.Context, size uint64) ([]string, error) { - // This isn't exactly accurate; see FileDescription.Listxattr. +func (FileDescriptionDefaultImpl) ListXattr(ctx context.Context, size uint64) ([]string, error) { + // This isn't exactly accurate; see FileDescription.ListXattr. return nil, syserror.ENOTSUP } -// Getxattr implements FileDescriptionImpl.Getxattr analogously to +// GetXattr implements FileDescriptionImpl.GetXattr analogously to // inode::i_opflags & IOP_XATTR == 0 in Linux. -func (FileDescriptionDefaultImpl) Getxattr(ctx context.Context, opts GetxattrOptions) (string, error) { +func (FileDescriptionDefaultImpl) GetXattr(ctx context.Context, opts GetXattrOptions) (string, error) { return "", syserror.ENOTSUP } -// Setxattr implements FileDescriptionImpl.Setxattr analogously to +// SetXattr implements FileDescriptionImpl.SetXattr analogously to // inode::i_opflags & IOP_XATTR == 0 in Linux. -func (FileDescriptionDefaultImpl) Setxattr(ctx context.Context, opts SetxattrOptions) error { +func (FileDescriptionDefaultImpl) SetXattr(ctx context.Context, opts SetXattrOptions) error { return syserror.ENOTSUP } -// Removexattr implements FileDescriptionImpl.Removexattr analogously to +// RemoveXattr implements FileDescriptionImpl.RemoveXattr analogously to // inode::i_opflags & IOP_XATTR == 0 in Linux. -func (FileDescriptionDefaultImpl) Removexattr(ctx context.Context, name string) error { +func (FileDescriptionDefaultImpl) RemoveXattr(ctx context.Context, name string) error { return syserror.ENOTSUP } // DirectoryFileDescriptionDefaultImpl may be embedded by implementations of // FileDescriptionImpl that always represent directories to obtain // implementations of non-directory I/O methods that return EISDIR. +// +// +stateify savable type DirectoryFileDescriptionDefaultImpl struct{} // Allocate implements DirectoryFileDescriptionDefaultImpl.Allocate. @@ -192,6 +200,8 @@ func (DirectoryFileDescriptionDefaultImpl) Write(ctx context.Context, src userme // DentryMetadataFileDescriptionImpl may be embedded by implementations of // FileDescriptionImpl for which FileDescriptionOptions.UseDentryMetadata is // true to obtain implementations of Stat and SetStat that panic. +// +// +stateify savable type DentryMetadataFileDescriptionImpl struct{} // Stat implements FileDescriptionImpl.Stat. @@ -206,12 +216,16 @@ func (DentryMetadataFileDescriptionImpl) SetStat(ctx context.Context, opts SetSt // DynamicBytesSource represents a data source for a // DynamicBytesFileDescriptionImpl. +// +// +stateify savable type DynamicBytesSource interface { // Generate writes the file's contents to buf. Generate(ctx context.Context, buf *bytes.Buffer) error } // StaticData implements DynamicBytesSource over a static string. +// +// +stateify savable type StaticData struct { Data string } @@ -238,14 +252,24 @@ type WritableDynamicBytesSource interface { // // DynamicBytesFileDescriptionImpl.SetDataSource() must be called before first // use. +// +// +stateify savable type DynamicBytesFileDescriptionImpl struct { data DynamicBytesSource // immutable - mu sync.Mutex // protects the following fields - buf bytes.Buffer + mu sync.Mutex `state:"nosave"` // protects the following fields + buf bytes.Buffer `state:".([]byte)"` off int64 lastRead int64 // offset at which the last Read, PRead, or Seek ended } +func (fd *DynamicBytesFileDescriptionImpl) saveBuf() []byte { + return fd.buf.Bytes() +} + +func (fd *DynamicBytesFileDescriptionImpl) loadBuf(p []byte) { + fd.buf.Write(p) +} + // SetDataSource must be called exactly once on fd before first use. func (fd *DynamicBytesFileDescriptionImpl) SetDataSource(data DynamicBytesSource) { fd.data = data @@ -378,6 +402,8 @@ func GenericConfigureMMap(fd *FileDescription, m memmap.Mappable, opts *memmap.M // LockFD may be used by most implementations of FileDescriptionImpl.Lock* // functions. Caller must call Init(). +// +// +stateify savable type LockFD struct { locks *FileLocks } @@ -405,6 +431,8 @@ func (fd *LockFD) UnlockBSD(ctx context.Context, uid fslock.UniqueID) error { // NoLockFD implements Lock*/Unlock* portion of FileDescriptionImpl interface // returning ENOLCK. +// +// +stateify savable type NoLockFD struct{} // LockBSD implements vfs.FileDescriptionImpl.LockBSD. diff --git a/pkg/sentry/vfs/filesystem.go b/pkg/sentry/vfs/filesystem.go index 46851f638..c93d94634 100644 --- a/pkg/sentry/vfs/filesystem.go +++ b/pkg/sentry/vfs/filesystem.go @@ -416,26 +416,26 @@ type FilesystemImpl interface { // ResolvingPath.Resolve*(), then !rp.Done(). UnlinkAt(ctx context.Context, rp *ResolvingPath) error - // ListxattrAt returns all extended attribute names for the file at rp. + // ListXattrAt returns all extended attribute names for the file at rp. // // Errors: // // - If extended attributes are not supported by the filesystem, - // ListxattrAt returns ENOTSUP. + // ListXattrAt returns ENOTSUP. // // - If the size of the list (including a NUL terminating byte after every // entry) would exceed size, ERANGE may be returned. Note that // implementations are free to ignore size entirely and return without // error). In all cases, if size is 0, the list should be returned without // error, regardless of size. - ListxattrAt(ctx context.Context, rp *ResolvingPath, size uint64) ([]string, error) + ListXattrAt(ctx context.Context, rp *ResolvingPath, size uint64) ([]string, error) - // GetxattrAt returns the value associated with the given extended + // GetXattrAt returns the value associated with the given extended // attribute for the file at rp. // // Errors: // - // - If extended attributes are not supported by the filesystem, GetxattrAt + // - If extended attributes are not supported by the filesystem, GetXattrAt // returns ENOTSUP. // // - If an extended attribute named opts.Name does not exist, ENODATA is @@ -445,30 +445,30 @@ type FilesystemImpl interface { // returned (note that implementations are free to ignore opts.Size entirely // and return without error). In all cases, if opts.Size is 0, the value // should be returned without error, regardless of size. - GetxattrAt(ctx context.Context, rp *ResolvingPath, opts GetxattrOptions) (string, error) + GetXattrAt(ctx context.Context, rp *ResolvingPath, opts GetXattrOptions) (string, error) - // SetxattrAt changes the value associated with the given extended + // SetXattrAt changes the value associated with the given extended // attribute for the file at rp. // // Errors: // - // - If extended attributes are not supported by the filesystem, SetxattrAt + // - If extended attributes are not supported by the filesystem, SetXattrAt // returns ENOTSUP. // // - If XATTR_CREATE is set in opts.Flag and opts.Name already exists, // EEXIST is returned. If XATTR_REPLACE is set and opts.Name does not exist, // ENODATA is returned. - SetxattrAt(ctx context.Context, rp *ResolvingPath, opts SetxattrOptions) error + SetXattrAt(ctx context.Context, rp *ResolvingPath, opts SetXattrOptions) error - // RemovexattrAt removes the given extended attribute from the file at rp. + // RemoveXattrAt removes the given extended attribute from the file at rp. // // Errors: // // - If extended attributes are not supported by the filesystem, - // RemovexattrAt returns ENOTSUP. + // RemoveXattrAt returns ENOTSUP. // // - If name does not exist, ENODATA is returned. - RemovexattrAt(ctx context.Context, rp *ResolvingPath, name string) error + RemoveXattrAt(ctx context.Context, rp *ResolvingPath, name string) error // BoundEndpointAt returns the Unix socket endpoint bound at the path rp. // @@ -506,6 +506,8 @@ type FilesystemImpl interface { // PrependPathAtVFSRootError is returned by implementations of // FilesystemImpl.PrependPath() when they encounter the contextual VFS root. +// +// +stateify savable type PrependPathAtVFSRootError struct{} // Error implements error.Error. @@ -516,6 +518,8 @@ func (PrependPathAtVFSRootError) Error() string { // PrependPathAtNonMountRootError is returned by implementations of // FilesystemImpl.PrependPath() when they encounter an independent ancestor // Dentry that is not the Mount root. +// +// +stateify savable type PrependPathAtNonMountRootError struct{} // Error implements error.Error. @@ -526,6 +530,8 @@ func (PrependPathAtNonMountRootError) Error() string { // PrependPathSyntheticError is returned by implementations of // FilesystemImpl.PrependPath() for which prepended names do not represent real // paths. +// +// +stateify savable type PrependPathSyntheticError struct{} // Error implements error.Error. diff --git a/pkg/sentry/vfs/filesystem_type.go b/pkg/sentry/vfs/filesystem_type.go index f2298f7f6..bc19db1d5 100644 --- a/pkg/sentry/vfs/filesystem_type.go +++ b/pkg/sentry/vfs/filesystem_type.go @@ -55,10 +55,13 @@ type registeredFilesystemType struct { // RegisterFilesystemTypeOptions contains options to // VirtualFilesystem.RegisterFilesystem(). +// +// +stateify savable type RegisterFilesystemTypeOptions struct { - // If AllowUserMount is true, allow calls to VirtualFilesystem.MountAt() - // for which MountOptions.InternalMount == false to use this filesystem - // type. + // AllowUserMount determines whether users are allowed to mount a file system + // of this type, i.e. through mount(2). If AllowUserMount is true, allow calls + // to VirtualFilesystem.MountAt() for which MountOptions.InternalMount == false + // to use this filesystem type. AllowUserMount bool // If AllowUserList is true, make this filesystem type visible in diff --git a/pkg/sentry/vfs/genericfstree/genericfstree.go b/pkg/sentry/vfs/genericfstree/genericfstree.go index 8882fa84a..2d27d9d35 100644 --- a/pkg/sentry/vfs/genericfstree/genericfstree.go +++ b/pkg/sentry/vfs/genericfstree/genericfstree.go @@ -27,6 +27,8 @@ import ( ) // Dentry is a required type parameter that is a struct with the given fields. +// +// +stateify savable type Dentry struct { // vfsd is the embedded vfs.Dentry corresponding to this vfs.DentryImpl. vfsd vfs.Dentry diff --git a/pkg/sentry/vfs/inotify.go b/pkg/sentry/vfs/inotify.go index aff220a61..3f0b8f45b 100644 --- a/pkg/sentry/vfs/inotify.go +++ b/pkg/sentry/vfs/inotify.go @@ -37,6 +37,8 @@ const inotifyEventBaseSize = 16 // // The way events are labelled appears somewhat arbitrary, but they must match // Linux so that IN_EXCL_UNLINK behaves as it does in Linux. +// +// +stateify savable type EventType uint8 // PathEvent and InodeEvent correspond to FSNOTIFY_EVENT_PATH and diff --git a/pkg/sentry/vfs/lock.go b/pkg/sentry/vfs/lock.go index 42666eebf..55783d4eb 100644 --- a/pkg/sentry/vfs/lock.go +++ b/pkg/sentry/vfs/lock.go @@ -33,6 +33,8 @@ import ( // Note that in Linux these two types of locks are _not_ cooperative, because // race and deadlock conditions make merging them prohibitive. We do the same // and keep them oblivious to each other. +// +// +stateify savable type FileLocks struct { // bsd is a set of BSD-style advisory file wide locks, see flock(2). bsd fslock.Locks diff --git a/pkg/sentry/vfs/memxattr/xattr.go b/pkg/sentry/vfs/memxattr/xattr.go index cc1e7d764..638b5d830 100644 --- a/pkg/sentry/vfs/memxattr/xattr.go +++ b/pkg/sentry/vfs/memxattr/xattr.go @@ -33,8 +33,8 @@ type SimpleExtendedAttributes struct { xattrs map[string]string } -// Getxattr returns the value at 'name'. -func (x *SimpleExtendedAttributes) Getxattr(opts *vfs.GetxattrOptions) (string, error) { +// GetXattr returns the value at 'name'. +func (x *SimpleExtendedAttributes) GetXattr(opts *vfs.GetXattrOptions) (string, error) { x.mu.RLock() value, ok := x.xattrs[opts.Name] x.mu.RUnlock() @@ -49,8 +49,8 @@ func (x *SimpleExtendedAttributes) Getxattr(opts *vfs.GetxattrOptions) (string, return value, nil } -// Setxattr sets 'value' at 'name'. -func (x *SimpleExtendedAttributes) Setxattr(opts *vfs.SetxattrOptions) error { +// SetXattr sets 'value' at 'name'. +func (x *SimpleExtendedAttributes) SetXattr(opts *vfs.SetXattrOptions) error { x.mu.Lock() defer x.mu.Unlock() if x.xattrs == nil { @@ -72,8 +72,8 @@ func (x *SimpleExtendedAttributes) Setxattr(opts *vfs.SetxattrOptions) error { return nil } -// Listxattr returns all names in xattrs. -func (x *SimpleExtendedAttributes) Listxattr(size uint64) ([]string, error) { +// ListXattr returns all names in xattrs. +func (x *SimpleExtendedAttributes) ListXattr(size uint64) ([]string, error) { // Keep track of the size of the buffer needed in listxattr(2) for the list. listSize := 0 x.mu.RLock() @@ -90,8 +90,8 @@ func (x *SimpleExtendedAttributes) Listxattr(size uint64) ([]string, error) { return names, nil } -// Removexattr removes the xattr at 'name'. -func (x *SimpleExtendedAttributes) Removexattr(name string) error { +// RemoveXattr removes the xattr at 'name'. +func (x *SimpleExtendedAttributes) RemoveXattr(name string) error { x.mu.Lock() defer x.mu.Unlock() if _, ok := x.xattrs[name]; !ok { diff --git a/pkg/sentry/vfs/mount.go b/pkg/sentry/vfs/mount.go index db5fb3bb1..dfc3ae6c0 100644 --- a/pkg/sentry/vfs/mount.go +++ b/pkg/sentry/vfs/mount.go @@ -18,14 +18,12 @@ import ( "bytes" "fmt" "math" - "path" "sort" "strings" "sync/atomic" "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" - "gvisor.dev/gvisor/pkg/fspath" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/syserror" ) @@ -67,7 +65,7 @@ type Mount struct { // // Invariant: key.parent != nil iff key.point != nil. key.point belongs to // key.parent.fs. - key mountKey + key mountKey `state:".(VirtualDentry)"` // ns is the namespace in which this Mount was mounted. ns is protected by // VirtualFilesystem.mountMu. @@ -154,13 +152,13 @@ type MountNamespace struct { // NewMountNamespace returns a new mount namespace with a root filesystem // configured by the given arguments. A reference is taken on the returned // MountNamespace. -func (vfs *VirtualFilesystem) NewMountNamespace(ctx context.Context, creds *auth.Credentials, source, fsTypeName string, opts *GetFilesystemOptions) (*MountNamespace, error) { +func (vfs *VirtualFilesystem) NewMountNamespace(ctx context.Context, creds *auth.Credentials, source, fsTypeName string, opts *MountOptions) (*MountNamespace, error) { rft := vfs.getFilesystemType(fsTypeName) if rft == nil { ctx.Warningf("Unknown filesystem type: %s", fsTypeName) return nil, syserror.ENODEV } - fs, root, err := rft.fsType.GetFilesystem(ctx, vfs, creds, source, *opts) + fs, root, err := rft.fsType.GetFilesystem(ctx, vfs, creds, source, opts.GetFilesystemOptions) if err != nil { return nil, err } @@ -169,7 +167,7 @@ func (vfs *VirtualFilesystem) NewMountNamespace(ctx context.Context, creds *auth mountpoints: make(map[*Dentry]uint32), } mntns.EnableLeakCheck() - mntns.root = newMount(vfs, fs, root, mntns, &MountOptions{}) + mntns.root = newMount(vfs, fs, root, mntns, opts) return mntns, nil } @@ -347,6 +345,7 @@ func (vfs *VirtualFilesystem) UmountAt(ctx context.Context, creds *auth.Credenti return nil } +// +stateify savable type umountRecursiveOptions struct { // If eager is true, ensure that future calls to Mount.tryIncMountedRef() // on umounted mounts fail. @@ -416,7 +415,7 @@ func (vfs *VirtualFilesystem) connectLocked(mnt *Mount, vd VirtualDentry, mntns } } mnt.IncRef() // dropped by callers of umountRecursiveLocked - mnt.storeKey(vd) + mnt.setKey(vd) if vd.mount.children == nil { vd.mount.children = make(map[*Mount]struct{}) } @@ -441,13 +440,13 @@ func (vfs *VirtualFilesystem) connectLocked(mnt *Mount, vd VirtualDentry, mntns // * vfs.mounts.seq must be in a writer critical section. // * mnt.parent() != nil. func (vfs *VirtualFilesystem) disconnectLocked(mnt *Mount) VirtualDentry { - vd := mnt.loadKey() + vd := mnt.getKey() if checkInvariants { if vd.mount != nil { panic("VFS.disconnectLocked called on disconnected mount") } } - mnt.storeKey(VirtualDentry{}) + mnt.loadKey(VirtualDentry{}) delete(vd.mount.children, mnt) atomic.AddUint32(&vd.dentry.mounts, math.MaxUint32) // -1 mnt.ns.mountpoints[vd.dentry]-- @@ -740,11 +739,23 @@ func (mntns *MountNamespace) Root() VirtualDentry { // // Preconditions: taskRootDir.Ok(). func (vfs *VirtualFilesystem) GenerateProcMounts(ctx context.Context, taskRootDir VirtualDentry, buf *bytes.Buffer) { - vfs.mountMu.Lock() - defer vfs.mountMu.Unlock() rootMnt := taskRootDir.mount + + vfs.mountMu.Lock() mounts := rootMnt.submountsLocked() + // Take a reference on mounts since we need to drop vfs.mountMu before + // calling vfs.PathnameReachable() (=> FilesystemImpl.PrependPath()). + for _, mnt := range mounts { + mnt.IncRef() + } + vfs.mountMu.Unlock() + defer func() { + for _, mnt := range mounts { + mnt.DecRef(ctx) + } + }() sort.Slice(mounts, func(i, j int) bool { return mounts[i].ID < mounts[j].ID }) + for _, mnt := range mounts { // Get the path to this mount relative to task root. mntRootVD := VirtualDentry{ @@ -755,7 +766,7 @@ func (vfs *VirtualFilesystem) GenerateProcMounts(ctx context.Context, taskRootDi if err != nil { // For some reason we didn't get a path. Log a warning // and run with empty path. - ctx.Warningf("Error getting pathname for mount root %+v: %v", mnt.root, err) + ctx.Warningf("VFS.GenerateProcMounts: error getting pathname for mount root %+v: %v", mnt.root, err) path = "" } if path == "" { @@ -789,11 +800,25 @@ func (vfs *VirtualFilesystem) GenerateProcMounts(ctx context.Context, taskRootDi // // Preconditions: taskRootDir.Ok(). func (vfs *VirtualFilesystem) GenerateProcMountInfo(ctx context.Context, taskRootDir VirtualDentry, buf *bytes.Buffer) { - vfs.mountMu.Lock() - defer vfs.mountMu.Unlock() rootMnt := taskRootDir.mount + + vfs.mountMu.Lock() mounts := rootMnt.submountsLocked() + // Take a reference on mounts since we need to drop vfs.mountMu before + // calling vfs.PathnameReachable() (=> FilesystemImpl.PrependPath()) or + // vfs.StatAt() (=> FilesystemImpl.StatAt()). + for _, mnt := range mounts { + mnt.IncRef() + } + vfs.mountMu.Unlock() + defer func() { + for _, mnt := range mounts { + mnt.DecRef(ctx) + } + }() sort.Slice(mounts, func(i, j int) bool { return mounts[i].ID < mounts[j].ID }) + + creds := auth.CredentialsFromContext(ctx) for _, mnt := range mounts { // Get the path to this mount relative to task root. mntRootVD := VirtualDentry{ @@ -804,7 +829,7 @@ func (vfs *VirtualFilesystem) GenerateProcMountInfo(ctx context.Context, taskRoo if err != nil { // For some reason we didn't get a path. Log a warning // and run with empty path. - ctx.Warningf("Error getting pathname for mount root %+v: %v", mnt.root, err) + ctx.Warningf("VFS.GenerateProcMountInfo: error getting pathname for mount root %+v: %v", mnt.root, err) path = "" } if path == "" { @@ -817,9 +842,10 @@ func (vfs *VirtualFilesystem) GenerateProcMountInfo(ctx context.Context, taskRoo Root: mntRootVD, Start: mntRootVD, } - statx, err := vfs.StatAt(ctx, auth.NewAnonymousCredentials(), pop, &StatOptions{}) + statx, err := vfs.StatAt(ctx, creds, pop, &StatOptions{}) if err != nil { // Well that's not good. Ignore this mount. + ctx.Warningf("VFS.GenerateProcMountInfo: failed to stat mount root %+v: %v", mnt.root, err) break } @@ -831,6 +857,9 @@ func (vfs *VirtualFilesystem) GenerateProcMountInfo(ctx context.Context, taskRoo fmt.Fprintf(buf, "%d ", mnt.ID) // (2) Parent ID (or this ID if there is no parent). + // Note that even if the call to mnt.parent() races with Mount + // destruction (which is possible since we're not holding vfs.mountMu), + // its Mount.ID will still be valid. pID := mnt.ID if p := mnt.parent(); p != nil { pID = p.ID @@ -879,30 +908,6 @@ func (vfs *VirtualFilesystem) GenerateProcMountInfo(ctx context.Context, taskRoo } } -// MakeSyntheticMountpoint creates parent directories of target if they do not -// exist and attempts to create a directory for the mountpoint. If a -// non-directory file already exists there then we allow it. -func (vfs *VirtualFilesystem) MakeSyntheticMountpoint(ctx context.Context, target string, root VirtualDentry, creds *auth.Credentials) error { - mkdirOpts := &MkdirOptions{Mode: 0777, ForSyntheticMountpoint: true} - - // Make sure the parent directory of target exists. - if err := vfs.MkdirAllAt(ctx, path.Dir(target), root, creds, mkdirOpts); err != nil { - return fmt.Errorf("failed to create parent directory of mountpoint %q: %w", target, err) - } - - // Attempt to mkdir the final component. If a file (of any type) exists - // then we let allow mounting on top of that because we do not require the - // target to be an existing directory, unlike Linux mount(2). - if err := vfs.MkdirAt(ctx, creds, &PathOperation{ - Root: root, - Start: root, - Path: fspath.Parse(target), - }, mkdirOpts); err != nil && err != syserror.EEXIST { - return fmt.Errorf("failed to create mountpoint %q: %w", target, err) - } - return nil -} - // manglePath replaces ' ', '\t', '\n', and '\\' with their octal equivalents. // See Linux fs/seq_file.c:mangle_path. func manglePath(p string) string { diff --git a/pkg/sentry/vfs/mount_test.go b/pkg/sentry/vfs/mount_test.go index 3335e4057..cb8c56bd3 100644 --- a/pkg/sentry/vfs/mount_test.go +++ b/pkg/sentry/vfs/mount_test.go @@ -38,7 +38,7 @@ func TestMountTableInsertLookup(t *testing.T) { mt.Init() mount := &Mount{} - mount.storeKey(VirtualDentry{&Mount{}, &Dentry{}}) + mount.setKey(VirtualDentry{&Mount{}, &Dentry{}}) mt.Insert(mount) if m := mt.Lookup(mount.parent(), mount.point()); m != mount { @@ -79,7 +79,7 @@ const enableComparativeBenchmarks = false func newBenchMount() *Mount { mount := &Mount{} - mount.storeKey(VirtualDentry{&Mount{}, &Dentry{}}) + mount.loadKey(VirtualDentry{&Mount{}, &Dentry{}}) return mount } @@ -94,7 +94,7 @@ func BenchmarkMountTableParallelLookup(b *testing.B) { for i := 0; i < numMounts; i++ { mount := newBenchMount() mt.Insert(mount) - keys = append(keys, mount.loadKey()) + keys = append(keys, mount.saveKey()) } var ready sync.WaitGroup @@ -146,7 +146,7 @@ func BenchmarkMountMapParallelLookup(b *testing.B) { keys := make([]VirtualDentry, 0, numMounts) for i := 0; i < numMounts; i++ { mount := newBenchMount() - key := mount.loadKey() + key := mount.saveKey() ms[key] = mount keys = append(keys, key) } @@ -201,7 +201,7 @@ func BenchmarkMountSyncMapParallelLookup(b *testing.B) { keys := make([]VirtualDentry, 0, numMounts) for i := 0; i < numMounts; i++ { mount := newBenchMount() - key := mount.loadKey() + key := mount.getKey() ms.Store(key, mount) keys = append(keys, key) } @@ -283,7 +283,7 @@ func BenchmarkMountMapNegativeLookup(b *testing.B) { ms := make(map[VirtualDentry]*Mount) for i := 0; i < numMounts; i++ { mount := newBenchMount() - ms[mount.loadKey()] = mount + ms[mount.getKey()] = mount } negkeys := make([]VirtualDentry, 0, numMounts) for i := 0; i < numMounts; i++ { @@ -318,7 +318,7 @@ func BenchmarkMountSyncMapNegativeLookup(b *testing.B) { var ms sync.Map for i := 0; i < numMounts; i++ { mount := newBenchMount() - ms.Store(mount.loadKey(), mount) + ms.Store(mount.saveKey(), mount) } negkeys := make([]VirtualDentry, 0, numMounts) for i := 0; i < numMounts; i++ { @@ -372,7 +372,7 @@ func BenchmarkMountMapInsert(b *testing.B) { b.ResetTimer() for i := range mounts { mount := mounts[i] - ms[mount.loadKey()] = mount + ms[mount.saveKey()] = mount } } @@ -392,7 +392,7 @@ func BenchmarkMountSyncMapInsert(b *testing.B) { b.ResetTimer() for i := range mounts { mount := mounts[i] - ms.Store(mount.loadKey(), mount) + ms.Store(mount.saveKey(), mount) } } @@ -425,13 +425,13 @@ func BenchmarkMountMapRemove(b *testing.B) { ms := make(map[VirtualDentry]*Mount) for i := range mounts { mount := mounts[i] - ms[mount.loadKey()] = mount + ms[mount.saveKey()] = mount } b.ResetTimer() for i := range mounts { mount := mounts[i] - delete(ms, mount.loadKey()) + delete(ms, mount.saveKey()) } } @@ -447,12 +447,12 @@ func BenchmarkMountSyncMapRemove(b *testing.B) { var ms sync.Map for i := range mounts { mount := mounts[i] - ms.Store(mount.loadKey(), mount) + ms.Store(mount.saveKey(), mount) } b.ResetTimer() for i := range mounts { mount := mounts[i] - ms.Delete(mount.loadKey()) + ms.Delete(mount.saveKey()) } } diff --git a/pkg/sentry/vfs/mount_unsafe.go b/pkg/sentry/vfs/mount_unsafe.go index da2a2e9c4..b7d122d22 100644 --- a/pkg/sentry/vfs/mount_unsafe.go +++ b/pkg/sentry/vfs/mount_unsafe.go @@ -34,6 +34,8 @@ import ( // structurally identical to VirtualDentry, but stores its fields as // unsafe.Pointer since mutators synchronize with VFS path traversal using // seqcounts. +// +// This is explicitly not savable. type mountKey struct { parent unsafe.Pointer // *Mount point unsafe.Pointer // *Dentry @@ -47,19 +49,23 @@ func (mnt *Mount) point() *Dentry { return (*Dentry)(atomic.LoadPointer(&mnt.key.point)) } -func (mnt *Mount) loadKey() VirtualDentry { +func (mnt *Mount) getKey() VirtualDentry { return VirtualDentry{ mount: mnt.parent(), dentry: mnt.point(), } } +func (mnt *Mount) saveKey() VirtualDentry { return mnt.getKey() } + // Invariant: mnt.key.parent == nil. vd.Ok(). -func (mnt *Mount) storeKey(vd VirtualDentry) { +func (mnt *Mount) setKey(vd VirtualDentry) { atomic.StorePointer(&mnt.key.parent, unsafe.Pointer(vd.mount)) atomic.StorePointer(&mnt.key.point, unsafe.Pointer(vd.dentry)) } +func (mnt *Mount) loadKey(vd VirtualDentry) { mnt.setKey(vd) } + // mountTable maps (mount parent, mount point) pairs to mounts. It supports // efficient concurrent lookup, even in the presence of concurrent mutators // (provided mutation is sufficiently uncommon). @@ -92,6 +98,7 @@ type mountTable struct { // length and cap in separate uint32s) for ~free. size uint64 + // FIXME(gvisor.dev/issue/1663): Slots need to be saved. slots unsafe.Pointer `state:"nosave"` // []mountSlot; never nil after Init } diff --git a/pkg/sentry/vfs/options.go b/pkg/sentry/vfs/options.go index dfc8573fd..bc79e5ecc 100644 --- a/pkg/sentry/vfs/options.go +++ b/pkg/sentry/vfs/options.go @@ -21,6 +21,8 @@ import ( // GetDentryOptions contains options to VirtualFilesystem.GetDentryAt() and // FilesystemImpl.GetDentryAt(). +// +// +stateify savable type GetDentryOptions struct { // If CheckSearchable is true, FilesystemImpl.GetDentryAt() must check that // the returned Dentry is a directory for which creds has search @@ -30,6 +32,8 @@ type GetDentryOptions struct { // MkdirOptions contains options to VirtualFilesystem.MkdirAt() and // FilesystemImpl.MkdirAt(). +// +// +stateify savable type MkdirOptions struct { // Mode is the file mode bits for the created directory. Mode linux.FileMode @@ -56,6 +60,8 @@ type MkdirOptions struct { // MknodOptions contains options to VirtualFilesystem.MknodAt() and // FilesystemImpl.MknodAt(). +// +// +stateify savable type MknodOptions struct { // Mode is the file type and mode bits for the created file. Mode linux.FileMode @@ -72,6 +78,8 @@ type MknodOptions struct { // MountFlags contains flags as specified for mount(2), e.g. MS_NOEXEC. // MS_RDONLY is not part of MountFlags because it's tracked in Mount.writers. +// +// +stateify savable type MountFlags struct { // NoExec is equivalent to MS_NOEXEC. NoExec bool @@ -93,6 +101,8 @@ type MountFlags struct { } // MountOptions contains options to VirtualFilesystem.MountAt(). +// +// +stateify savable type MountOptions struct { // Flags contains flags as specified for mount(2), e.g. MS_NOEXEC. Flags MountFlags @@ -103,13 +113,17 @@ type MountOptions struct { // GetFilesystemOptions contains options to FilesystemType.GetFilesystem(). GetFilesystemOptions GetFilesystemOptions - // If InternalMount is true, allow the use of filesystem types for which - // RegisterFilesystemTypeOptions.AllowUserMount == false. + // InternalMount indicates whether the mount operation is coming from the + // application, i.e. through mount(2). If InternalMount is true, allow the use + // of filesystem types for which RegisterFilesystemTypeOptions.AllowUserMount + // == false. InternalMount bool } // OpenOptions contains options to VirtualFilesystem.OpenAt() and // FilesystemImpl.OpenAt(). +// +// +stateify savable type OpenOptions struct { // Flags contains access mode and flags as specified for open(2). // @@ -135,6 +149,8 @@ type OpenOptions struct { // ReadOptions contains options to FileDescription.PRead(), // FileDescriptionImpl.PRead(), FileDescription.Read(), and // FileDescriptionImpl.Read(). +// +// +stateify savable type ReadOptions struct { // Flags contains flags as specified for preadv2(2). Flags uint32 @@ -142,6 +158,8 @@ type ReadOptions struct { // RenameOptions contains options to VirtualFilesystem.RenameAt() and // FilesystemImpl.RenameAt(). +// +// +stateify savable type RenameOptions struct { // Flags contains flags as specified for renameat2(2). Flags uint32 @@ -153,6 +171,8 @@ type RenameOptions struct { // SetStatOptions contains options to VirtualFilesystem.SetStatAt(), // FilesystemImpl.SetStatAt(), FileDescription.SetStat(), and // FileDescriptionImpl.SetStat(). +// +// +stateify savable type SetStatOptions struct { // Stat is the metadata that should be set. Only fields indicated by // Stat.Mask should be set. @@ -174,6 +194,8 @@ type SetStatOptions struct { // BoundEndpointOptions contains options to VirtualFilesystem.BoundEndpointAt() // and FilesystemImpl.BoundEndpointAt(). +// +// +stateify savable type BoundEndpointOptions struct { // Addr is the path of the file whose socket endpoint is being retrieved. // It is generally irrelevant: most endpoints are stored at a dentry that @@ -190,10 +212,12 @@ type BoundEndpointOptions struct { Addr string } -// GetxattrOptions contains options to VirtualFilesystem.GetxattrAt(), -// FilesystemImpl.GetxattrAt(), FileDescription.Getxattr(), and -// FileDescriptionImpl.Getxattr(). -type GetxattrOptions struct { +// GetXattrOptions contains options to VirtualFilesystem.GetXattrAt(), +// FilesystemImpl.GetXattrAt(), FileDescription.GetXattr(), and +// FileDescriptionImpl.GetXattr(). +// +// +stateify savable +type GetXattrOptions struct { // Name is the name of the extended attribute to retrieve. Name string @@ -204,10 +228,12 @@ type GetxattrOptions struct { Size uint64 } -// SetxattrOptions contains options to VirtualFilesystem.SetxattrAt(), -// FilesystemImpl.SetxattrAt(), FileDescription.Setxattr(), and -// FileDescriptionImpl.Setxattr(). -type SetxattrOptions struct { +// SetXattrOptions contains options to VirtualFilesystem.SetXattrAt(), +// FilesystemImpl.SetXattrAt(), FileDescription.SetXattr(), and +// FileDescriptionImpl.SetXattr(). +// +// +stateify savable +type SetXattrOptions struct { // Name is the name of the extended attribute being mutated. Name string @@ -221,6 +247,8 @@ type SetxattrOptions struct { // StatOptions contains options to VirtualFilesystem.StatAt(), // FilesystemImpl.StatAt(), FileDescription.Stat(), and // FileDescriptionImpl.Stat(). +// +// +stateify savable type StatOptions struct { // Mask is the set of fields in the returned Statx that the FilesystemImpl // or FileDescriptionImpl should provide. Bits are as in linux.Statx.Mask. @@ -238,6 +266,8 @@ type StatOptions struct { } // UmountOptions contains options to VirtualFilesystem.UmountAt(). +// +// +stateify savable type UmountOptions struct { // Flags contains flags as specified for umount2(2). Flags uint32 @@ -246,6 +276,8 @@ type UmountOptions struct { // WriteOptions contains options to FileDescription.PWrite(), // FileDescriptionImpl.PWrite(), FileDescription.Write(), and // FileDescriptionImpl.Write(). +// +// +stateify savable type WriteOptions struct { // Flags contains flags as specified for pwritev2(2). Flags uint32 diff --git a/pkg/sentry/vfs/permissions.go b/pkg/sentry/vfs/permissions.go index 014b928ed..d48520d58 100644 --- a/pkg/sentry/vfs/permissions.go +++ b/pkg/sentry/vfs/permissions.go @@ -16,6 +16,7 @@ package vfs import ( "math" + "strings" "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" @@ -25,6 +26,8 @@ import ( ) // AccessTypes is a bitmask of Unix file permissions. +// +// +stateify savable type AccessTypes uint16 // Bits in AccessTypes. @@ -284,3 +287,40 @@ func CheckLimit(ctx context.Context, offset, size int64) (int64, error) { } return size, nil } + +// CheckXattrPermissions checks permissions for extended attribute access. +// This is analogous to fs/xattr.c:xattr_permission(). Some key differences: +// * Does not check for read-only filesystem property. +// * Does not check inode immutability or append only mode. In both cases EPERM +// must be returned by filesystem implementations. +// * Does not do inode permission checks. Filesystem implementations should +// handle inode permission checks as they may differ across implementations. +func CheckXattrPermissions(creds *auth.Credentials, ats AccessTypes, mode linux.FileMode, kuid auth.KUID, name string) error { + switch { + case strings.HasPrefix(name, linux.XATTR_TRUSTED_PREFIX): + // The trusted.* namespace can only be accessed by privileged + // users. + if creds.HasCapability(linux.CAP_SYS_ADMIN) { + return nil + } + if ats.MayWrite() { + return syserror.EPERM + } + return syserror.ENODATA + case strings.HasPrefix(name, linux.XATTR_USER_PREFIX): + // In the user.* namespace, only regular files and directories can have + // extended attributes. For sticky directories, only the owner and + // privileged users can write attributes. + filetype := mode.FileType() + if filetype != linux.ModeRegular && filetype != linux.ModeDirectory { + if ats.MayWrite() { + return syserror.EPERM + } + return syserror.ENODATA + } + if filetype == linux.ModeDirectory && mode&linux.ModeSticky != 0 && ats.MayWrite() && !CanActAsOwner(creds, kuid) { + return syserror.EPERM + } + } + return nil +} diff --git a/pkg/sentry/vfs/resolving_path.go b/pkg/sentry/vfs/resolving_path.go index 3304372d9..e4fd55012 100644 --- a/pkg/sentry/vfs/resolving_path.go +++ b/pkg/sentry/vfs/resolving_path.go @@ -35,6 +35,8 @@ import ( // FilesystemImpl methods. // // ResolvingPath is loosely analogous to Linux's struct nameidata. +// +// +stateify savable type ResolvingPath struct { vfs *VirtualFilesystem root VirtualDentry // refs borrowed from PathOperation @@ -88,6 +90,7 @@ func init() { // so error "constants" are really mutable vars, necessitating somewhat // expensive interface object comparisons. +// +stateify savable type resolveMountRootOrJumpError struct{} // Error implements error.Error. @@ -95,6 +98,7 @@ func (resolveMountRootOrJumpError) Error() string { return "resolving mount root or jump" } +// +stateify savable type resolveMountPointError struct{} // Error implements error.Error. @@ -102,6 +106,7 @@ func (resolveMountPointError) Error() string { return "resolving mount point" } +// +stateify savable type resolveAbsSymlinkError struct{} // Error implements error.Error. diff --git a/pkg/sentry/vfs/vfs.go b/pkg/sentry/vfs/vfs.go index ec27562d6..5bd756ea5 100644 --- a/pkg/sentry/vfs/vfs.go +++ b/pkg/sentry/vfs/vfs.go @@ -163,6 +163,8 @@ func (vfs *VirtualFilesystem) Init(ctx context.Context) error { // PathOperation is passed to VFS methods by pointer to reduce memory copying: // it's somewhat large and should never escape. (Options structs are passed by // pointer to VFS and FileDescription methods for the same reason.) +// +// +stateify savable type PathOperation struct { // Root is the VFS root. References on Root are borrowed from the provider // of the PathOperation. @@ -297,6 +299,8 @@ func (vfs *VirtualFilesystem) LinkAt(ctx context.Context, creds *auth.Credential // MkdirAt creates a directory at the given path. func (vfs *VirtualFilesystem) MkdirAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, opts *MkdirOptions) error { if !pop.Path.Begin.Ok() { + // pop.Path should not be empty in operations that create/delete files. + // This is consistent with mkdirat(dirfd, "", mode). if pop.Path.Absolute { return syserror.EEXIST } @@ -333,6 +337,8 @@ func (vfs *VirtualFilesystem) MkdirAt(ctx context.Context, creds *auth.Credentia // error from the syserror package. func (vfs *VirtualFilesystem) MknodAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, opts *MknodOptions) error { if !pop.Path.Begin.Ok() { + // pop.Path should not be empty in operations that create/delete files. + // This is consistent with mknodat(dirfd, "", mode, dev). if pop.Path.Absolute { return syserror.EEXIST } @@ -518,6 +524,8 @@ func (vfs *VirtualFilesystem) RenameAt(ctx context.Context, creds *auth.Credenti // RmdirAt removes the directory at the given path. func (vfs *VirtualFilesystem) RmdirAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation) error { if !pop.Path.Begin.Ok() { + // pop.Path should not be empty in operations that create/delete files. + // This is consistent with unlinkat(dirfd, "", AT_REMOVEDIR). if pop.Path.Absolute { return syserror.EBUSY } @@ -599,6 +607,8 @@ func (vfs *VirtualFilesystem) StatFSAt(ctx context.Context, creds *auth.Credenti // SymlinkAt creates a symbolic link at the given path with the given target. func (vfs *VirtualFilesystem) SymlinkAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, target string) error { if !pop.Path.Begin.Ok() { + // pop.Path should not be empty in operations that create/delete files. + // This is consistent with symlinkat(oldpath, newdirfd, ""). if pop.Path.Absolute { return syserror.EEXIST } @@ -631,6 +641,8 @@ func (vfs *VirtualFilesystem) SymlinkAt(ctx context.Context, creds *auth.Credent // UnlinkAt deletes the non-directory file at the given path. func (vfs *VirtualFilesystem) UnlinkAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation) error { if !pop.Path.Begin.Ok() { + // pop.Path should not be empty in operations that create/delete files. + // This is consistent with unlinkat(dirfd, "", 0). if pop.Path.Absolute { return syserror.EBUSY } @@ -662,12 +674,6 @@ func (vfs *VirtualFilesystem) UnlinkAt(ctx context.Context, creds *auth.Credenti // BoundEndpointAt gets the bound endpoint at the given path, if one exists. func (vfs *VirtualFilesystem) BoundEndpointAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, opts *BoundEndpointOptions) (transport.BoundEndpoint, error) { - if !pop.Path.Begin.Ok() { - if pop.Path.Absolute { - return nil, syserror.ECONNREFUSED - } - return nil, syserror.ENOENT - } rp := vfs.getResolvingPath(creds, pop) for { bep, err := rp.mount.fs.impl.BoundEndpointAt(ctx, rp, *opts) @@ -687,12 +693,12 @@ func (vfs *VirtualFilesystem) BoundEndpointAt(ctx context.Context, creds *auth.C } } -// ListxattrAt returns all extended attribute names for the file at the given +// ListXattrAt returns all extended attribute names for the file at the given // path. -func (vfs *VirtualFilesystem) ListxattrAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, size uint64) ([]string, error) { +func (vfs *VirtualFilesystem) ListXattrAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, size uint64) ([]string, error) { rp := vfs.getResolvingPath(creds, pop) for { - names, err := rp.mount.fs.impl.ListxattrAt(ctx, rp, size) + names, err := rp.mount.fs.impl.ListXattrAt(ctx, rp, size) if err == nil { vfs.putResolvingPath(ctx, rp) return names, nil @@ -712,12 +718,12 @@ func (vfs *VirtualFilesystem) ListxattrAt(ctx context.Context, creds *auth.Crede } } -// GetxattrAt returns the value associated with the given extended attribute +// GetXattrAt returns the value associated with the given extended attribute // for the file at the given path. -func (vfs *VirtualFilesystem) GetxattrAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, opts *GetxattrOptions) (string, error) { +func (vfs *VirtualFilesystem) GetXattrAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, opts *GetXattrOptions) (string, error) { rp := vfs.getResolvingPath(creds, pop) for { - val, err := rp.mount.fs.impl.GetxattrAt(ctx, rp, *opts) + val, err := rp.mount.fs.impl.GetXattrAt(ctx, rp, *opts) if err == nil { vfs.putResolvingPath(ctx, rp) return val, nil @@ -729,12 +735,12 @@ func (vfs *VirtualFilesystem) GetxattrAt(ctx context.Context, creds *auth.Creden } } -// SetxattrAt changes the value associated with the given extended attribute +// SetXattrAt changes the value associated with the given extended attribute // for the file at the given path. -func (vfs *VirtualFilesystem) SetxattrAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, opts *SetxattrOptions) error { +func (vfs *VirtualFilesystem) SetXattrAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, opts *SetXattrOptions) error { rp := vfs.getResolvingPath(creds, pop) for { - err := rp.mount.fs.impl.SetxattrAt(ctx, rp, *opts) + err := rp.mount.fs.impl.SetXattrAt(ctx, rp, *opts) if err == nil { vfs.putResolvingPath(ctx, rp) return nil @@ -746,11 +752,11 @@ func (vfs *VirtualFilesystem) SetxattrAt(ctx context.Context, creds *auth.Creden } } -// RemovexattrAt removes the given extended attribute from the file at rp. -func (vfs *VirtualFilesystem) RemovexattrAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, name string) error { +// RemoveXattrAt removes the given extended attribute from the file at rp. +func (vfs *VirtualFilesystem) RemoveXattrAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, name string) error { rp := vfs.getResolvingPath(creds, pop) for { - err := rp.mount.fs.impl.RemovexattrAt(ctx, rp, name) + err := rp.mount.fs.impl.RemoveXattrAt(ctx, rp, name) if err == nil { vfs.putResolvingPath(ctx, rp) return nil @@ -815,6 +821,30 @@ func (vfs *VirtualFilesystem) MkdirAllAt(ctx context.Context, currentPath string return nil } +// MakeSyntheticMountpoint creates parent directories of target if they do not +// exist and attempts to create a directory for the mountpoint. If a +// non-directory file already exists there then we allow it. +func (vfs *VirtualFilesystem) MakeSyntheticMountpoint(ctx context.Context, target string, root VirtualDentry, creds *auth.Credentials) error { + mkdirOpts := &MkdirOptions{Mode: 0777, ForSyntheticMountpoint: true} + + // Make sure the parent directory of target exists. + if err := vfs.MkdirAllAt(ctx, path.Dir(target), root, creds, mkdirOpts); err != nil { + return fmt.Errorf("failed to create parent directory of mountpoint %q: %w", target, err) + } + + // Attempt to mkdir the final component. If a file (of any type) exists + // then we let allow mounting on top of that because we do not require the + // target to be an existing directory, unlike Linux mount(2). + if err := vfs.MkdirAt(ctx, creds, &PathOperation{ + Root: root, + Start: root, + Path: fspath.Parse(target), + }, mkdirOpts); err != nil && err != syserror.EEXIST { + return fmt.Errorf("failed to create mountpoint %q: %w", target, err) + } + return nil +} + // A VirtualDentry represents a node in a VFS tree, by combining a Dentry // (which represents a node in a Filesystem's tree) and a Mount (which // represents the Filesystem's position in a VFS mount tree). |