diff options
Diffstat (limited to 'pkg/abi')
| -rw-r--r-- | pkg/abi/linux/BUILD | 3 | ||||
| -rw-r--r-- | pkg/abi/linux/context.go | 36 | ||||
| -rw-r--r-- | pkg/abi/linux/ioctl_tun.go | 3 | ||||
| -rw-r--r-- | pkg/abi/linux/signal.go | 344 | ||||
| -rw-r--r-- | pkg/abi/linux/xattr.go | 6 |
5 files changed, 374 insertions, 18 deletions
diff --git a/pkg/abi/linux/BUILD b/pkg/abi/linux/BUILD index a461bb65e..38288bdb7 100644 --- a/pkg/abi/linux/BUILD +++ b/pkg/abi/linux/BUILD @@ -15,6 +15,7 @@ go_library( "bpf.go", "capability.go", "clone.go", + "context.go", "dev.go", "elf.go", "epoll.go", @@ -77,6 +78,8 @@ go_library( deps = [ "//pkg/abi", "//pkg/bits", + "//pkg/context", + "//pkg/hostarch", "//pkg/marshal", "//pkg/marshal/primitive", ], diff --git a/pkg/abi/linux/context.go b/pkg/abi/linux/context.go new file mode 100644 index 000000000..d2dbba183 --- /dev/null +++ b/pkg/abi/linux/context.go @@ -0,0 +1,36 @@ +// Copyright 2021 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 linux + +import ( + "gvisor.dev/gvisor/pkg/context" +) + +// contextID is the linux package's type for context.Context.Value keys. +type contextID int + +const ( + // CtxSignalNoInfoFunc is a Context.Value key for a function to send signals. + CtxSignalNoInfoFunc contextID = iota +) + +// SignalNoInfoFuncFromContext returns a callback function that can be used to send a +// signal to the given context. +func SignalNoInfoFuncFromContext(ctx context.Context) func(Signal) error { + if f := ctx.Value(CtxSignalNoInfoFunc); f != nil { + return f.(func(Signal) error) + } + return nil +} diff --git a/pkg/abi/linux/ioctl_tun.go b/pkg/abi/linux/ioctl_tun.go index c59c9c136..ea4fdca0f 100644 --- a/pkg/abi/linux/ioctl_tun.go +++ b/pkg/abi/linux/ioctl_tun.go @@ -26,4 +26,7 @@ const ( IFF_TAP = 0x0002 IFF_NO_PI = 0x1000 IFF_NOFILTER = 0x1000 + + // According to linux/if_tun.h "This flag has no real effect" + IFF_ONE_QUEUE = 0x2000 ) diff --git a/pkg/abi/linux/signal.go b/pkg/abi/linux/signal.go index 6ca57ffbb..06a4c6401 100644 --- a/pkg/abi/linux/signal.go +++ b/pkg/abi/linux/signal.go @@ -16,6 +16,7 @@ package linux import ( "gvisor.dev/gvisor/pkg/bits" + "gvisor.dev/gvisor/pkg/hostarch" ) const ( @@ -165,7 +166,7 @@ const ( SIG_IGN = 1 ) -// Signal action flags for rt_sigaction(2), from uapi/asm-generic/signal.h +// Signal action flags for rt_sigaction(2), from uapi/asm-generic/signal.h. const ( SA_NOCLDSTOP = 0x00000001 SA_NOCLDWAIT = 0x00000002 @@ -179,21 +180,17 @@ const ( SA_ONESHOT = SA_RESETHAND ) -// Signal info types. +// Signal stack flags for signalstack(2), from include/uapi/linux/signal.h. const ( - SI_MASK = 0xffff0000 - SI_KILL = 0 << 16 - SI_TIMER = 1 << 16 - SI_POLL = 2 << 16 - SI_FAULT = 3 << 16 - SI_CHLD = 4 << 16 - SI_RT = 5 << 16 - SI_MESGQ = 6 << 16 - SI_SYS = 7 << 16 + SS_ONSTACK = 1 + SS_DISABLE = 2 ) // SIGPOLL si_codes. const ( + // SI_POLL is defined as __SI_POLL in Linux 2.6. + SI_POLL = 2 << 16 + // POLL_IN indicates that data input available. POLL_IN = SI_POLL | 1 @@ -213,6 +210,75 @@ const ( POLL_HUP = SI_POLL | 6 ) +// Possible values for si_code. +const ( + // SI_USER is sent by kill, sigsend, raise. + SI_USER = 0 + + // SI_KERNEL is sent by the kernel from somewhere. + SI_KERNEL = 0x80 + + // SI_QUEUE is sent by sigqueue. + SI_QUEUE = -1 + + // SI_TIMER is sent by timer expiration. + SI_TIMER = -2 + + // SI_MESGQ is sent by real time mesq state change. + SI_MESGQ = -3 + + // SI_ASYNCIO is sent by AIO completion. + SI_ASYNCIO = -4 + + // SI_SIGIO is sent by queued SIGIO. + SI_SIGIO = -5 + + // SI_TKILL is sent by tkill system call. + SI_TKILL = -6 + + // SI_DETHREAD is sent by execve() killing subsidiary threads. + SI_DETHREAD = -7 + + // SI_ASYNCNL is sent by glibc async name lookup completion. + SI_ASYNCNL = -60 +) + +// CLD_* codes are only meaningful for SIGCHLD. +const ( + // CLD_EXITED indicates that a task exited. + CLD_EXITED = 1 + + // CLD_KILLED indicates that a task was killed by a signal. + CLD_KILLED = 2 + + // CLD_DUMPED indicates that a task was killed by a signal and then dumped + // core. + CLD_DUMPED = 3 + + // CLD_TRAPPED indicates that a task was stopped by ptrace. + CLD_TRAPPED = 4 + + // CLD_STOPPED indicates that a thread group completed a group stop. + CLD_STOPPED = 5 + + // CLD_CONTINUED indicates that a group-stopped thread group was continued. + CLD_CONTINUED = 6 +) + +// SYS_* codes are only meaningful for SIGSYS. +const ( + // SYS_SECCOMP indicates that a signal originates from seccomp. + SYS_SECCOMP = 1 +) + +// Possible values for Sigevent.Notify, aka struct sigevent::sigev_notify. +const ( + SIGEV_SIGNAL = 0 + SIGEV_NONE = 1 + SIGEV_THREAD = 2 + SIGEV_THREAD_ID = 4 +) + // Sigevent represents struct sigevent. // // +marshal @@ -227,10 +293,252 @@ type Sigevent struct { UnRemainder [44]byte } -// Possible values for Sigevent.Notify, aka struct sigevent::sigev_notify. -const ( - SIGEV_SIGNAL = 0 - SIGEV_NONE = 1 - SIGEV_THREAD = 2 - SIGEV_THREAD_ID = 4 -) +// SigAction represents struct sigaction. +// +// +marshal +// +stateify savable +type SigAction struct { + Handler uint64 + Flags uint64 + Restorer uint64 + Mask SignalSet +} + +// SignalStack represents information about a user stack, and is equivalent to +// stack_t. +// +// +marshal +// +stateify savable +type SignalStack struct { + Addr uint64 + Flags uint32 + _ uint32 + Size uint64 +} + +// Contains checks if the stack pointer is within this stack. +func (s *SignalStack) Contains(sp hostarch.Addr) bool { + return hostarch.Addr(s.Addr) < sp && sp <= hostarch.Addr(s.Addr+s.Size) +} + +// Top returns the stack's top address. +func (s *SignalStack) Top() hostarch.Addr { + return hostarch.Addr(s.Addr + s.Size) +} + +// IsEnabled returns true iff this signal stack is marked as enabled. +func (s *SignalStack) IsEnabled() bool { + return s.Flags&SS_DISABLE == 0 +} + +// SignalInfo represents information about a signal being delivered, and is +// equivalent to struct siginfo in linux kernel(linux/include/uapi/asm-generic/siginfo.h). +// +// +marshal +// +stateify savable +type SignalInfo struct { + Signo int32 // Signal number + Errno int32 // Errno value + Code int32 // Signal code + _ uint32 + + // struct siginfo::_sifields is a union. In SignalInfo, fields in the union + // are accessed through methods. + // + // For reference, here is the definition of _sifields: (_sigfault._trapno, + // which does not exist on x86, omitted for clarity) + // + // union { + // int _pad[SI_PAD_SIZE]; + // + // /* kill() */ + // struct { + // __kernel_pid_t _pid; /* sender's pid */ + // __ARCH_SI_UID_T _uid; /* sender's uid */ + // } _kill; + // + // /* POSIX.1b timers */ + // struct { + // __kernel_timer_t _tid; /* timer id */ + // int _overrun; /* overrun count */ + // char _pad[sizeof( __ARCH_SI_UID_T) - sizeof(int)]; + // sigval_t _sigval; /* same as below */ + // int _sys_private; /* not to be passed to user */ + // } _timer; + // + // /* POSIX.1b signals */ + // struct { + // __kernel_pid_t _pid; /* sender's pid */ + // __ARCH_SI_UID_T _uid; /* sender's uid */ + // sigval_t _sigval; + // } _rt; + // + // /* SIGCHLD */ + // struct { + // __kernel_pid_t _pid; /* which child */ + // __ARCH_SI_UID_T _uid; /* sender's uid */ + // int _status; /* exit code */ + // __ARCH_SI_CLOCK_T _utime; + // __ARCH_SI_CLOCK_T _stime; + // } _sigchld; + // + // /* SIGILL, SIGFPE, SIGSEGV, SIGBUS */ + // struct { + // void *_addr; /* faulting insn/memory ref. */ + // short _addr_lsb; /* LSB of the reported address */ + // } _sigfault; + // + // /* SIGPOLL */ + // struct { + // __ARCH_SI_BAND_T _band; /* POLL_IN, POLL_OUT, POLL_MSG */ + // int _fd; + // } _sigpoll; + // + // /* SIGSYS */ + // struct { + // void *_call_addr; /* calling user insn */ + // int _syscall; /* triggering system call number */ + // unsigned int _arch; /* AUDIT_ARCH_* of syscall */ + // } _sigsys; + // } _sifields; + // + // _sifields is padded so that the size of siginfo is SI_MAX_SIZE = 128 + // bytes. + Fields [128 - 16]byte +} + +// FixSignalCodeForUser fixes up si_code. +// +// The si_code we get from Linux may contain the kernel-specific code in the +// top 16 bits if it's positive (e.g., from ptrace). Linux's +// copy_siginfo_to_user does +// err |= __put_user((short)from->si_code, &to->si_code); +// to mask out those bits and we need to do the same. +func (s *SignalInfo) FixSignalCodeForUser() { + if s.Code > 0 { + s.Code &= 0x0000ffff + } +} + +// PID returns the si_pid field. +func (s *SignalInfo) PID() int32 { + return int32(hostarch.ByteOrder.Uint32(s.Fields[0:4])) +} + +// SetPID mutates the si_pid field. +func (s *SignalInfo) SetPID(val int32) { + hostarch.ByteOrder.PutUint32(s.Fields[0:4], uint32(val)) +} + +// UID returns the si_uid field. +func (s *SignalInfo) UID() int32 { + return int32(hostarch.ByteOrder.Uint32(s.Fields[4:8])) +} + +// SetUID mutates the si_uid field. +func (s *SignalInfo) SetUID(val int32) { + hostarch.ByteOrder.PutUint32(s.Fields[4:8], uint32(val)) +} + +// Sigval returns the sigval field, which is aliased to both si_int and si_ptr. +func (s *SignalInfo) Sigval() uint64 { + return hostarch.ByteOrder.Uint64(s.Fields[8:16]) +} + +// SetSigval mutates the sigval field. +func (s *SignalInfo) SetSigval(val uint64) { + hostarch.ByteOrder.PutUint64(s.Fields[8:16], val) +} + +// TimerID returns the si_timerid field. +func (s *SignalInfo) TimerID() TimerID { + return TimerID(hostarch.ByteOrder.Uint32(s.Fields[0:4])) +} + +// SetTimerID sets the si_timerid field. +func (s *SignalInfo) SetTimerID(val TimerID) { + hostarch.ByteOrder.PutUint32(s.Fields[0:4], uint32(val)) +} + +// Overrun returns the si_overrun field. +func (s *SignalInfo) Overrun() int32 { + return int32(hostarch.ByteOrder.Uint32(s.Fields[4:8])) +} + +// SetOverrun sets the si_overrun field. +func (s *SignalInfo) SetOverrun(val int32) { + hostarch.ByteOrder.PutUint32(s.Fields[4:8], uint32(val)) +} + +// Addr returns the si_addr field. +func (s *SignalInfo) Addr() uint64 { + return hostarch.ByteOrder.Uint64(s.Fields[0:8]) +} + +// SetAddr sets the si_addr field. +func (s *SignalInfo) SetAddr(val uint64) { + hostarch.ByteOrder.PutUint64(s.Fields[0:8], val) +} + +// Status returns the si_status field. +func (s *SignalInfo) Status() int32 { + return int32(hostarch.ByteOrder.Uint32(s.Fields[8:12])) +} + +// SetStatus mutates the si_status field. +func (s *SignalInfo) SetStatus(val int32) { + hostarch.ByteOrder.PutUint32(s.Fields[8:12], uint32(val)) +} + +// CallAddr returns the si_call_addr field. +func (s *SignalInfo) CallAddr() uint64 { + return hostarch.ByteOrder.Uint64(s.Fields[0:8]) +} + +// SetCallAddr mutates the si_call_addr field. +func (s *SignalInfo) SetCallAddr(val uint64) { + hostarch.ByteOrder.PutUint64(s.Fields[0:8], val) +} + +// Syscall returns the si_syscall field. +func (s *SignalInfo) Syscall() int32 { + return int32(hostarch.ByteOrder.Uint32(s.Fields[8:12])) +} + +// SetSyscall mutates the si_syscall field. +func (s *SignalInfo) SetSyscall(val int32) { + hostarch.ByteOrder.PutUint32(s.Fields[8:12], uint32(val)) +} + +// Arch returns the si_arch field. +func (s *SignalInfo) Arch() uint32 { + return hostarch.ByteOrder.Uint32(s.Fields[12:16]) +} + +// SetArch mutates the si_arch field. +func (s *SignalInfo) SetArch(val uint32) { + hostarch.ByteOrder.PutUint32(s.Fields[12:16], val) +} + +// Band returns the si_band field. +func (s *SignalInfo) Band() int64 { + return int64(hostarch.ByteOrder.Uint64(s.Fields[0:8])) +} + +// SetBand mutates the si_band field. +func (s *SignalInfo) SetBand(val int64) { + // Note: this assumes the platform uses `long` as `__ARCH_SI_BAND_T`. + // On some platforms, which gVisor doesn't support, `__ARCH_SI_BAND_T` is + // `int`. See siginfo.h. + hostarch.ByteOrder.PutUint64(s.Fields[0:8], uint64(val)) +} + +// FD returns the si_fd field. +func (s *SignalInfo) FD() uint32 { + return hostarch.ByteOrder.Uint32(s.Fields[8:12]) +} + +// SetFD mutates the si_fd field. +func (s *SignalInfo) SetFD(val uint32) { + hostarch.ByteOrder.PutUint32(s.Fields[8:12], val) +} diff --git a/pkg/abi/linux/xattr.go b/pkg/abi/linux/xattr.go index 8ef837f27..1fa7a4f4f 100644 --- a/pkg/abi/linux/xattr.go +++ b/pkg/abi/linux/xattr.go @@ -23,6 +23,12 @@ const ( XATTR_CREATE = 1 XATTR_REPLACE = 2 + XATTR_SECURITY_PREFIX = "security." + XATTR_SECURITY_PREFIX_LEN = len(XATTR_SECURITY_PREFIX) + + XATTR_SYSTEM_PREFIX = "system." + XATTR_SYSTEM_PREFIX_LEN = len(XATTR_SYSTEM_PREFIX) + XATTR_TRUSTED_PREFIX = "trusted." XATTR_TRUSTED_PREFIX_LEN = len(XATTR_TRUSTED_PREFIX) |