diff options
Diffstat (limited to 'runsc/boot')
-rw-r--r-- | runsc/boot/BUILD | 28 | ||||
-rw-r--r-- | runsc/boot/compat.go | 10 | ||||
-rw-r--r-- | runsc/boot/compat_amd64.go | 22 | ||||
-rw-r--r-- | runsc/boot/compat_arm64.go | 22 | ||||
-rw-r--r-- | runsc/boot/config.go | 20 | ||||
-rw-r--r-- | runsc/boot/controller.go | 24 | ||||
-rw-r--r-- | runsc/boot/fds.go | 81 | ||||
-rw-r--r-- | runsc/boot/filter/config.go | 23 | ||||
-rw-r--r-- | runsc/boot/filter/extra_filters_msan.go | 2 | ||||
-rw-r--r-- | runsc/boot/fs.go | 110 | ||||
-rw-r--r-- | runsc/boot/loader.go | 422 | ||||
-rw-r--r-- | runsc/boot/loader_amd64.go | 27 | ||||
-rw-r--r-- | runsc/boot/loader_arm64.go | 27 | ||||
-rw-r--r-- | runsc/boot/loader_test.go | 178 | ||||
-rw-r--r-- | runsc/boot/network.go | 77 | ||||
-rw-r--r-- | runsc/boot/pprof/BUILD | 11 | ||||
-rw-r--r-- | runsc/boot/pprof/pprof.go (renamed from runsc/boot/pprof.go) | 6 | ||||
-rw-r--r-- | runsc/boot/user.go | 170 | ||||
-rw-r--r-- | runsc/boot/user_test.go | 254 | ||||
-rw-r--r-- | runsc/boot/vfs.go | 375 |
20 files changed, 1069 insertions, 820 deletions
diff --git a/runsc/boot/BUILD b/runsc/boot/BUILD index ae4dd102a..a907c103b 100644 --- a/runsc/boot/BUILD +++ b/runsc/boot/BUILD @@ -12,18 +12,15 @@ go_library( "controller.go", "debug.go", "events.go", - "fds.go", "fs.go", "limits.go", "loader.go", - "loader_amd64.go", - "loader_arm64.go", "network.go", - "pprof.go", "strace.go", - "user.go", + "vfs.go", ], visibility = [ + "//pkg/test:__subpackages__", "//runsc:__subpackages__", "//test:__subpackages__", ], @@ -34,6 +31,7 @@ go_library( "//pkg/control/server", "//pkg/cpuid", "//pkg/eventchannel", + "//pkg/fspath", "//pkg/log", "//pkg/memutil", "//pkg/rand", @@ -41,6 +39,8 @@ go_library( "//pkg/sentry/arch", "//pkg/sentry/arch:registers_go_proto", "//pkg/sentry/control", + "//pkg/sentry/devices/memdev", + "//pkg/sentry/fdimport", "//pkg/sentry/fs", "//pkg/sentry/fs/dev", "//pkg/sentry/fs/gofer", @@ -50,6 +50,14 @@ go_library( "//pkg/sentry/fs/sys", "//pkg/sentry/fs/tmpfs", "//pkg/sentry/fs/tty", + "//pkg/sentry/fs/user", + "//pkg/sentry/fsimpl/devpts", + "//pkg/sentry/fsimpl/devtmpfs", + "//pkg/sentry/fsimpl/gofer", + "//pkg/sentry/fsimpl/host", + "//pkg/sentry/fsimpl/proc", + "//pkg/sentry/fsimpl/sys", + "//pkg/sentry/fsimpl/tmpfs", "//pkg/sentry/inet", "//pkg/sentry/kernel", "//pkg/sentry/kernel:uncaught_signal_go_proto", @@ -67,17 +75,18 @@ go_library( "//pkg/sentry/socket/unix", "//pkg/sentry/state", "//pkg/sentry/strace", - "//pkg/sentry/syscalls/linux", "//pkg/sentry/syscalls/linux/vfs2", "//pkg/sentry/time", "//pkg/sentry/unimpl:unimplemented_syscall_go_proto", "//pkg/sentry/usage", + "//pkg/sentry/vfs", "//pkg/sentry/watchdog", "//pkg/sync", "//pkg/syserror", "//pkg/tcpip", "//pkg/tcpip/link/fdbased", "//pkg/tcpip/link/loopback", + "//pkg/tcpip/link/qdisc/fifo", "//pkg/tcpip/link/sniffer", "//pkg/tcpip/network/arp", "//pkg/tcpip/network/ipv4", @@ -88,9 +97,9 @@ go_library( "//pkg/tcpip/transport/tcp", "//pkg/tcpip/transport/udp", "//pkg/urpc", - "//pkg/usermem", "//runsc/boot/filter", "//runsc/boot/platforms", + "//runsc/boot/pprof", "//runsc/specutils", "@com_github_golang_protobuf//proto:go_default_library", "@com_github_opencontainers_runtime-spec//specs-go:go_default_library", @@ -105,19 +114,20 @@ go_test( "compat_test.go", "fs_test.go", "loader_test.go", - "user_test.go", ], library = ":boot", deps = [ "//pkg/control/server", + "//pkg/fspath", "//pkg/log", "//pkg/p9", "//pkg/sentry/contexttest", "//pkg/sentry/fs", - "//pkg/sentry/kernel/auth", + "//pkg/sentry/vfs", "//pkg/sync", "//pkg/unet", "//runsc/fsgofer", "@com_github_opencontainers_runtime-spec//specs-go:go_default_library", + "@org_golang_x_sys//unix:go_default_library", ], ) diff --git a/runsc/boot/compat.go b/runsc/boot/compat.go index 8995d678e..84c67cbc2 100644 --- a/runsc/boot/compat.go +++ b/runsc/boot/compat.go @@ -65,7 +65,7 @@ func newCompatEmitter(logFD int) (*compatEmitter, error) { if logFD > 0 { f := os.NewFile(uintptr(logFD), "user log file") - target := &log.MultiEmitter{c.sink, &log.K8sJSONEmitter{log.Writer{Next: f}}} + target := &log.MultiEmitter{c.sink, log.K8sJSONEmitter{&log.Writer{Next: f}}} c.sink = &log.BasicLogger{Level: log.Info, Emitter: target} } return c, nil @@ -119,7 +119,13 @@ func (c *compatEmitter) emitUnimplementedSyscall(us *spb.UnimplementedSyscall) { } if tr.shouldReport(regs) { - c.sink.Infof("Unsupported syscall: %s, regs: %+v", c.nameMap.Name(uintptr(sysnr)), regs) + name := c.nameMap.Name(uintptr(sysnr)) + c.sink.Infof("Unsupported syscall %s(%#x,%#x,%#x,%#x,%#x,%#x). It is "+ + "likely that you can safely ignore this message and that this is not "+ + "the cause of any error. Please, refer to %s/%s for more information.", + name, argVal(0, regs), argVal(1, regs), argVal(2, regs), argVal(3, regs), + argVal(4, regs), argVal(5, regs), syscallLink, name) + tr.onReported(regs) } } diff --git a/runsc/boot/compat_amd64.go b/runsc/boot/compat_amd64.go index 42b0ca8b0..8eb76b2ba 100644 --- a/runsc/boot/compat_amd64.go +++ b/runsc/boot/compat_amd64.go @@ -24,8 +24,12 @@ import ( "gvisor.dev/gvisor/pkg/sentry/strace" ) -// reportLimit is the max number of events that should be reported per tracker. -const reportLimit = 100 +const ( + // reportLimit is the max number of events that should be reported per + // tracker. + reportLimit = 100 + syscallLink = "https://gvisor.dev/c/linux/amd64" +) // newRegs create a empty Registers instance. func newRegs() *rpb.Registers { @@ -36,22 +40,22 @@ func newRegs() *rpb.Registers { } } -func argVal(argIdx int, regs *rpb.Registers) uint32 { +func argVal(argIdx int, regs *rpb.Registers) uint64 { amd64Regs := regs.GetArch().(*rpb.Registers_Amd64).Amd64 switch argIdx { case 0: - return uint32(amd64Regs.Rdi) + return amd64Regs.Rdi case 1: - return uint32(amd64Regs.Rsi) + return amd64Regs.Rsi case 2: - return uint32(amd64Regs.Rdx) + return amd64Regs.Rdx case 3: - return uint32(amd64Regs.R10) + return amd64Regs.R10 case 4: - return uint32(amd64Regs.R8) + return amd64Regs.R8 case 5: - return uint32(amd64Regs.R9) + return amd64Regs.R9 } panic(fmt.Sprintf("invalid syscall argument index %d", argIdx)) } diff --git a/runsc/boot/compat_arm64.go b/runsc/boot/compat_arm64.go index f784cd237..bce9d95b3 100644 --- a/runsc/boot/compat_arm64.go +++ b/runsc/boot/compat_arm64.go @@ -23,8 +23,12 @@ import ( "gvisor.dev/gvisor/pkg/sentry/strace" ) -// reportLimit is the max number of events that should be reported per tracker. -const reportLimit = 100 +const ( + // reportLimit is the max number of events that should be reported per + // tracker. + reportLimit = 100 + syscallLink = "https://gvisor.dev/c/linux/arm64" +) // newRegs create a empty Registers instance. func newRegs() *rpb.Registers { @@ -35,22 +39,22 @@ func newRegs() *rpb.Registers { } } -func argVal(argIdx int, regs *rpb.Registers) uint32 { +func argVal(argIdx int, regs *rpb.Registers) uint64 { arm64Regs := regs.GetArch().(*rpb.Registers_Arm64).Arm64 switch argIdx { case 0: - return uint32(arm64Regs.R0) + return arm64Regs.R0 case 1: - return uint32(arm64Regs.R1) + return arm64Regs.R1 case 2: - return uint32(arm64Regs.R2) + return arm64Regs.R2 case 3: - return uint32(arm64Regs.R3) + return arm64Regs.R3 case 4: - return uint32(arm64Regs.R4) + return arm64Regs.R4 case 5: - return uint32(arm64Regs.R5) + return arm64Regs.R5 } panic(fmt.Sprintf("invalid syscall argument index %d", argIdx)) } diff --git a/runsc/boot/config.go b/runsc/boot/config.go index 35391030f..bcec7e4db 100644 --- a/runsc/boot/config.go +++ b/runsc/boot/config.go @@ -158,6 +158,9 @@ type Config struct { // DebugLog is the path to log debug information to, if not empty. DebugLog string + // PanicLog is the path to log GO's runtime messages, if not empty. + PanicLog string + // DebugLogFormat is the log format for debug. DebugLogFormat string @@ -184,6 +187,10 @@ type Config struct { // SoftwareGSO indicates that software segmentation offload is enabled. SoftwareGSO bool + // QDisc indicates the type of queuening discipline to use by default + // for non-loopback interfaces. + QDisc QueueingDiscipline + // LogPackets indicates that all network packets should be logged. LogPackets bool @@ -234,8 +241,10 @@ type Config struct { // ReferenceLeakMode sets reference leak check mode ReferenceLeakMode refs.LeakMode - // OverlayfsStaleRead causes cached FDs to reopen after a file is opened for - // write to workaround overlayfs limitation on kernels before 4.19. + // OverlayfsStaleRead instructs the sandbox to assume that the root mount + // is on a Linux overlayfs mount, which does not necessarily preserve + // coherence between read-only and subsequent writable file descriptors + // representing the "same" file. OverlayfsStaleRead bool // TestOnlyAllowRunAsCurrentUserWithoutChroot should only be used in @@ -269,6 +278,7 @@ func (c *Config) ToFlags() []string { "--log=" + c.LogFilename, "--log-format=" + c.LogFormat, "--debug-log=" + c.DebugLog, + "--panic-log=" + c.PanicLog, "--debug-log-format=" + c.DebugLogFormat, "--file-access=" + c.FileAccess.String(), "--overlay=" + strconv.FormatBool(c.Overlay), @@ -290,6 +300,7 @@ func (c *Config) ToFlags() []string { "--gso=" + strconv.FormatBool(c.HardwareGSO), "--software-gso=" + strconv.FormatBool(c.SoftwareGSO), "--overlayfs-stale-read=" + strconv.FormatBool(c.OverlayfsStaleRead), + "--qdisc=" + c.QDisc.String(), } if c.CPUNumFromQuota { f = append(f, "--cpu-num-from-quota") @@ -301,5 +312,10 @@ func (c *Config) ToFlags() []string { if len(c.TestOnlyTestNameEnv) != 0 { f = append(f, "--TESTONLY-test-name-env="+c.TestOnlyTestNameEnv) } + + if c.VFS2 { + f = append(f, "--vfs2=true") + } + return f } diff --git a/runsc/boot/controller.go b/runsc/boot/controller.go index 9c9e94864..8125d5061 100644 --- a/runsc/boot/controller.go +++ b/runsc/boot/controller.go @@ -32,6 +32,7 @@ import ( "gvisor.dev/gvisor/pkg/sentry/watchdog" "gvisor.dev/gvisor/pkg/tcpip/stack" "gvisor.dev/gvisor/pkg/urpc" + "gvisor.dev/gvisor/runsc/boot/pprof" "gvisor.dev/gvisor/runsc/specutils" ) @@ -100,11 +101,14 @@ const ( // Profiling related commands (see pprof.go for more details). const ( - StartCPUProfile = "Profile.StartCPUProfile" - StopCPUProfile = "Profile.StopCPUProfile" - HeapProfile = "Profile.HeapProfile" - StartTrace = "Profile.StartTrace" - StopTrace = "Profile.StopTrace" + StartCPUProfile = "Profile.StartCPUProfile" + StopCPUProfile = "Profile.StopCPUProfile" + HeapProfile = "Profile.HeapProfile" + GoroutineProfile = "Profile.GoroutineProfile" + BlockProfile = "Profile.BlockProfile" + MutexProfile = "Profile.MutexProfile" + StartTrace = "Profile.StartTrace" + StopTrace = "Profile.StopTrace" ) // Logging related commands (see logging.go for more details). @@ -142,7 +146,7 @@ func newController(fd int, l *Loader) (*controller, error) { } srv.Register(manager) - if eps, ok := l.k.NetworkStack().(*netstack.Stack); ok { + if eps, ok := l.k.RootNetworkNamespace().Stack().(*netstack.Stack); ok { net := &Network{ Stack: eps.Stack, } @@ -341,7 +345,7 @@ func (cm *containerManager) Restore(o *RestoreOpts, _ *struct{}) error { return fmt.Errorf("creating memory file: %v", err) } k.SetMemoryFile(mf) - networkStack := cm.l.k.NetworkStack() + networkStack := cm.l.k.RootNetworkNamespace().Stack() cm.l.k = k // Set up the restore environment. @@ -365,9 +369,9 @@ func (cm *containerManager) Restore(o *RestoreOpts, _ *struct{}) error { } if cm.l.conf.ProfileEnable { - // initializePProf opens /proc/self/maps, so has to be - // called before installing seccomp filters. - initializePProf() + // pprof.Initialize opens /proc/self/maps, so has to be called before + // installing seccomp filters. + pprof.Initialize() } // Seccomp filters have to be applied before parsing the state file. diff --git a/runsc/boot/fds.go b/runsc/boot/fds.go deleted file mode 100644 index 417d2d5fb..000000000 --- a/runsc/boot/fds.go +++ /dev/null @@ -1,81 +0,0 @@ -// Copyright 2018 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 boot - -import ( - "fmt" - - "gvisor.dev/gvisor/pkg/context" - "gvisor.dev/gvisor/pkg/sentry/fs" - "gvisor.dev/gvisor/pkg/sentry/fs/host" - "gvisor.dev/gvisor/pkg/sentry/kernel" -) - -// createFDTable creates an FD table that contains stdin, stdout, and stderr. -// If console is true, then ioctl calls will be passed through to the host FD. -// Upon success, createFDMap dups then closes stdioFDs. -func createFDTable(ctx context.Context, console bool, stdioFDs []int) (*kernel.FDTable, error) { - if len(stdioFDs) != 3 { - return nil, fmt.Errorf("stdioFDs should contain exactly 3 FDs (stdin, stdout, and stderr), but %d FDs received", len(stdioFDs)) - } - - k := kernel.KernelFromContext(ctx) - fdTable := k.NewFDTable() - defer fdTable.DecRef() - mounter := fs.FileOwnerFromContext(ctx) - - var ttyFile *fs.File - for appFD, hostFD := range stdioFDs { - var appFile *fs.File - - if console && appFD < 3 { - // Import the file as a host TTY file. - if ttyFile == nil { - var err error - appFile, err = host.ImportFile(ctx, hostFD, mounter, true /* isTTY */) - if err != nil { - return nil, err - } - defer appFile.DecRef() - - // Remember this in the TTY file, as we will - // use it for the other stdio FDs. - ttyFile = appFile - } else { - // Re-use the existing TTY file, as all three - // stdio FDs must point to the same fs.File in - // order to share TTY state, specifically the - // foreground process group id. - appFile = ttyFile - } - } else { - // Import the file as a regular host file. - var err error - appFile, err = host.ImportFile(ctx, hostFD, mounter, false /* isTTY */) - if err != nil { - return nil, err - } - defer appFile.DecRef() - } - - // Add the file to the FD map. - if err := fdTable.NewFDAt(ctx, int32(appFD), appFile, kernel.FDFlags{}); err != nil { - return nil, err - } - } - - fdTable.IncRef() - return fdTable, nil -} diff --git a/runsc/boot/filter/config.go b/runsc/boot/filter/config.go index c69f4c602..60e33425f 100644 --- a/runsc/boot/filter/config.go +++ b/runsc/boot/filter/config.go @@ -44,7 +44,7 @@ var allowedSyscalls = seccomp.SyscallRules{ { seccomp.AllowAny{}, seccomp.AllowAny{}, - seccomp.AllowValue(0), + seccomp.AllowValue(syscall.O_CLOEXEC), }, }, syscall.SYS_EPOLL_CREATE1: {}, @@ -229,7 +229,11 @@ var allowedSyscalls = seccomp.SyscallRules{ syscall.SYS_NANOSLEEP: {}, syscall.SYS_PPOLL: {}, syscall.SYS_PREAD64: {}, + syscall.SYS_PREADV: {}, + unix.SYS_PREADV2: {}, syscall.SYS_PWRITE64: {}, + syscall.SYS_PWRITEV: {}, + unix.SYS_PWRITEV2: {}, syscall.SYS_READ: {}, syscall.SYS_RECVMSG: []seccomp.Rule{ { @@ -282,12 +286,29 @@ var allowedSyscalls = seccomp.SyscallRules{ {seccomp.AllowAny{}, seccomp.AllowValue(syscall.SHUT_RDWR)}, }, syscall.SYS_SIGALTSTACK: {}, + unix.SYS_STATX: {}, syscall.SYS_SYNC_FILE_RANGE: {}, + syscall.SYS_TEE: []seccomp.Rule{ + { + seccomp.AllowAny{}, + seccomp.AllowAny{}, + seccomp.AllowValue(1), /* len */ + seccomp.AllowValue(unix.SPLICE_F_NONBLOCK), /* flags */ + }, + }, syscall.SYS_TGKILL: []seccomp.Rule{ { seccomp.AllowValue(uint64(os.Getpid())), }, }, + syscall.SYS_UTIMENSAT: []seccomp.Rule{ + { + seccomp.AllowAny{}, + seccomp.AllowValue(0), /* null pathname */ + seccomp.AllowAny{}, + seccomp.AllowValue(0), /* flags */ + }, + }, syscall.SYS_WRITE: {}, // The only user in rawfile.NonBlockingWrite3 always passes iovcnt with // values 2 or 3. Three iovec-s are passed, when the PACKET_VNET_HDR diff --git a/runsc/boot/filter/extra_filters_msan.go b/runsc/boot/filter/extra_filters_msan.go index 5e5a3c998..209e646a7 100644 --- a/runsc/boot/filter/extra_filters_msan.go +++ b/runsc/boot/filter/extra_filters_msan.go @@ -26,6 +26,8 @@ import ( func instrumentationFilters() seccomp.SyscallRules { Report("MSAN is enabled: syscall filters less restrictive!") return seccomp.SyscallRules{ + syscall.SYS_CLONE: {}, + syscall.SYS_MMAP: {}, syscall.SYS_SCHED_GETAFFINITY: {}, syscall.SYS_SET_ROBUST_LIST: {}, } diff --git a/runsc/boot/fs.go b/runsc/boot/fs.go index 0f62842ea..b98a1eb50 100644 --- a/runsc/boot/fs.go +++ b/runsc/boot/fs.go @@ -37,6 +37,13 @@ import ( "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/fs/gofer" "gvisor.dev/gvisor/pkg/sentry/fs/ramfs" + "gvisor.dev/gvisor/pkg/sentry/fs/user" + "gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts" + "gvisor.dev/gvisor/pkg/sentry/fsimpl/devtmpfs" + gofervfs2 "gvisor.dev/gvisor/pkg/sentry/fsimpl/gofer" + procvfs2 "gvisor.dev/gvisor/pkg/sentry/fsimpl/proc" + sysvfs2 "gvisor.dev/gvisor/pkg/sentry/fsimpl/sys" + tmpfsvfs2 "gvisor.dev/gvisor/pkg/sentry/fsimpl/tmpfs" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/syserror" @@ -44,27 +51,19 @@ import ( ) const ( - // Filesystem name for 9p gofer mounts. - rootFsName = "9p" - // Device name for root mount. rootDevice = "9pfs-/" // MountPrefix is the annotation prefix for mount hints. MountPrefix = "dev.gvisor.spec.mount." - // Filesystems that runsc supports. - bind = "bind" - devpts = "devpts" - devtmpfs = "devtmpfs" - proc = "proc" - sysfs = "sysfs" - tmpfs = "tmpfs" - nonefs = "none" + // Supported filesystems that map to different internal filesystem. + bind = "bind" + nonefs = "none" ) // tmpfs has some extra supported options that we must pass through. -var tmpfsAllowedOptions = []string{"mode", "uid", "gid"} +var tmpfsAllowedData = []string{"mode", "uid", "gid"} func addOverlay(ctx context.Context, conf *Config, lower *fs.Inode, name string, lowerFlags fs.MountSourceFlags) (*fs.Inode, error) { // Upper layer uses the same flags as lower, but it must be read-write. @@ -108,12 +107,12 @@ func compileMounts(spec *specs.Spec) []specs.Mount { // Always mount /dev. mounts = append(mounts, specs.Mount{ - Type: devtmpfs, + Type: devtmpfs.Name, Destination: "/dev", }) mounts = append(mounts, specs.Mount{ - Type: devpts, + Type: devpts.Name, Destination: "/dev/pts", }) @@ -137,13 +136,13 @@ func compileMounts(spec *specs.Spec) []specs.Mount { var mandatoryMounts []specs.Mount if !procMounted { mandatoryMounts = append(mandatoryMounts, specs.Mount{ - Type: proc, + Type: procvfs2.Name, Destination: "/proc", }) } if !sysMounted { mandatoryMounts = append(mandatoryMounts, specs.Mount{ - Type: sysfs, + Type: sysvfs2.Name, Destination: "/sys", }) } @@ -155,13 +154,17 @@ func compileMounts(spec *specs.Spec) []specs.Mount { return mounts } -// p9MountOptions creates a slice of options for a p9 mount. -func p9MountOptions(fd int, fa FileAccessType) []string { +// p9MountData creates a slice of p9 mount data. +func p9MountData(fd int, fa FileAccessType, vfs2 bool) []string { opts := []string{ "trans=fd", "rfdno=" + strconv.Itoa(fd), "wfdno=" + strconv.Itoa(fd), - "privateunixsocket=true", + } + if !vfs2 { + // privateunixsocket is always enabled in VFS2. VFS1 requires explicit + // enablement. + opts = append(opts, "privateunixsocket=true") } if fa == FileAccessShared { opts = append(opts, "cache=remote_revalidating") @@ -231,8 +234,8 @@ func isSupportedMountFlag(fstype, opt string) bool { case "rw", "ro", "noatime", "noexec": return true } - if fstype == tmpfs { - ok, err := parseMountOption(opt, tmpfsAllowedOptions...) + if fstype == tmpfsvfs2.Name { + ok, err := parseMountOption(opt, tmpfsAllowedData...) return ok && err == nil } return false @@ -278,6 +281,9 @@ func subtargets(root string, mnts []specs.Mount) []string { } func setupContainerFS(ctx context.Context, conf *Config, mntr *containerMounter, procArgs *kernel.CreateProcessArgs) error { + if conf.VFS2 { + return setupContainerVFS2(ctx, conf, mntr, procArgs) + } mns, err := mntr.setupFS(conf, procArgs) if err != nil { return err @@ -286,17 +292,10 @@ func setupContainerFS(ctx context.Context, conf *Config, mntr *containerMounter, // Set namespace here so that it can be found in ctx. procArgs.MountNamespace = mns - return setExecutablePath(ctx, procArgs) -} - -// setExecutablePath sets the procArgs.Filename by searching the PATH for an -// executable matching the procArgs.Argv[0]. -func setExecutablePath(ctx context.Context, procArgs *kernel.CreateProcessArgs) error { - paths := fs.GetPath(procArgs.Envv) - exe := procArgs.Argv[0] - f, err := procArgs.MountNamespace.ResolveExecutablePath(ctx, procArgs.WorkingDirectory, exe, paths) + // Resolve the executable path from working dir and environment. + f, err := user.ResolveExecutablePath(ctx, procArgs.Credentials, procArgs.MountNamespace, procArgs.Envv, procArgs.WorkingDirectory, procArgs.Argv[0]) if err != nil { - return fmt.Errorf("searching for executable %q, cwd: %q, $PATH=%q: %v", exe, procArgs.WorkingDirectory, strings.Join(paths, ":"), err) + return fmt.Errorf("searching for executable %q, cwd: %q, envv: %q: %v", procArgs.Argv[0], procArgs.WorkingDirectory, procArgs.Envv, err) } procArgs.Filename = f return nil @@ -438,7 +437,7 @@ func (m *mountHint) setOptions(val string) error { } func (m *mountHint) isSupported() bool { - return m.mount.Type == tmpfs && m.share == pod + return m.mount.Type == tmpfsvfs2.Name && m.share == pod } // checkCompatible verifies that shared mount is compatible with master. @@ -573,11 +572,14 @@ func newContainerMounter(spec *specs.Spec, goferFDs []int, k *kernel.Kernel, hin // should be mounted (e.g. a volume shared between containers). It must be // called for the root container only. func (c *containerMounter) processHints(conf *Config) error { + if conf.VFS2 { + return nil + } ctx := c.k.SupervisorContext() for _, hint := range c.hints.mounts { // TODO(b/142076984): Only support tmpfs for now. Bind mounts require a // common gofer to mount all shared volumes. - if hint.mount.Type != tmpfs { + if hint.mount.Type != tmpfsvfs2.Name { continue } log.Infof("Mounting master of shared mount %q from %q type %q", hint.name, hint.mount.Source, hint.mount.Type) @@ -714,7 +716,7 @@ func (c *containerMounter) createRootMount(ctx context.Context, conf *Config) (* fd := c.fds.remove() log.Infof("Mounting root over 9P, ioFD: %d", fd) p9FS := mustFindFilesystem("9p") - opts := p9MountOptions(fd, conf.FileAccess) + opts := p9MountData(fd, conf.FileAccess, false /* vfs2 */) if conf.OverlayfsStaleRead { // We can't check for overlayfs here because sandbox is chroot'ed and gofer @@ -760,30 +762,27 @@ func (c *containerMounter) getMountNameAndOptions(conf *Config, m specs.Mount) ( ) switch m.Type { - case devpts, devtmpfs, proc, sysfs: + case devpts.Name, devtmpfs.Name, procvfs2.Name, sysvfs2.Name: fsName = m.Type case nonefs: - fsName = sysfs - case tmpfs: + fsName = sysvfs2.Name + case tmpfsvfs2.Name: fsName = m.Type var err error - opts, err = parseAndFilterOptions(m.Options, tmpfsAllowedOptions...) + opts, err = parseAndFilterOptions(m.Options, tmpfsAllowedData...) if err != nil { return "", nil, false, err } case bind: fd := c.fds.remove() - fsName = "9p" - opts = p9MountOptions(fd, c.getMountAccessType(m)) + fsName = gofervfs2.Name + opts = p9MountData(fd, c.getMountAccessType(m), conf.VFS2) // If configured, add overlay to all writable mounts. useOverlay = conf.Overlay && !mountFlags(m.Options).ReadOnly default: - // TODO(nlacasse): Support all the mount types and make this a fatal error. - // Most applications will "just work" without them, so this is a warning - // for now. log.Warningf("ignoring unknown filesystem type %q", m.Type) } return fsName, opts, useOverlay, nil @@ -824,7 +823,20 @@ func (c *containerMounter) mountSubmount(ctx context.Context, conf *Config, mns inode, err := filesystem.Mount(ctx, mountDevice(m), mf, strings.Join(opts, ","), nil) if err != nil { - return fmt.Errorf("creating mount with source %q: %v", m.Source, err) + err := fmt.Errorf("creating mount with source %q: %v", m.Source, err) + // Check to see if this is a common error due to a Linux bug. + // This error is generated here in order to cause it to be + // printed to the user using Docker via 'runsc create' etc. rather + // than simply printed to the logs for the 'runsc boot' command. + // + // We check the error message string rather than type because the + // actual error types (syscall.EIO, syscall.EPIPE) are lost by file system + // implementation (e.g. p9). + // TODO(gvisor.dev/issue/1765): Remove message when bug is resolved. + if strings.Contains(err.Error(), syscall.EIO.Error()) || strings.Contains(err.Error(), syscall.EPIPE.Error()) { + return fmt.Errorf("%v: %s", err, specutils.FaqErrorMsg("memlock", "you may be encountering a Linux kernel bug")) + } + return err } // If there are submounts, we need to overlay the mount on top of a ramfs @@ -919,7 +931,7 @@ func (c *containerMounter) createRestoreEnvironment(conf *Config) (*fs.RestoreEn // Add root mount. fd := c.fds.remove() - opts := p9MountOptions(fd, conf.FileAccess) + opts := p9MountData(fd, conf.FileAccess, false /* vfs2 */) mf := fs.MountSourceFlags{} if c.root.Readonly || conf.Overlay { @@ -931,7 +943,7 @@ func (c *containerMounter) createRestoreEnvironment(conf *Config) (*fs.RestoreEn Flags: mf, DataString: strings.Join(opts, ","), } - renv.MountSources[rootFsName] = append(renv.MountSources[rootFsName], rootMount) + renv.MountSources[gofervfs2.Name] = append(renv.MountSources[gofervfs2.Name], rootMount) // Add submounts. var tmpMounted bool @@ -947,7 +959,7 @@ func (c *containerMounter) createRestoreEnvironment(conf *Config) (*fs.RestoreEn // TODO(b/67958150): handle '/tmp' properly (see mountTmp()). if !tmpMounted { tmpMount := specs.Mount{ - Type: tmpfs, + Type: tmpfsvfs2.Name, Destination: "/tmp", } if err := c.addRestoreMount(conf, renv, tmpMount); err != nil { @@ -1003,11 +1015,11 @@ func (c *containerMounter) mountTmp(ctx context.Context, conf *Config, mns *fs.M // No '/tmp' found (or fallthrough from above). Safe to mount internal // tmpfs. tmpMount := specs.Mount{ - Type: tmpfs, + Type: tmpfsvfs2.Name, Destination: "/tmp", // Sticky bit is added to prevent accidental deletion of files from // another user. This is normally done for /tmp. - Options: []string{"mode=1777"}, + Options: []string{"mode=01777"}, } return c.mountSubmount(ctx, conf, mns, root, tmpMount) diff --git a/runsc/boot/loader.go b/runsc/boot/loader.go index 9f0d5d7af..002479612 100644 --- a/runsc/boot/loader.go +++ b/runsc/boot/loader.go @@ -26,16 +26,19 @@ import ( specs "github.com/opencontainers/runtime-spec/specs-go" "golang.org/x/sys/unix" - "gvisor.dev/gvisor/pkg/abi" "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/cpuid" "gvisor.dev/gvisor/pkg/log" "gvisor.dev/gvisor/pkg/memutil" "gvisor.dev/gvisor/pkg/rand" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/control" + "gvisor.dev/gvisor/pkg/sentry/fdimport" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/fs/host" + "gvisor.dev/gvisor/pkg/sentry/fs/user" + hostvfs2 "gvisor.dev/gvisor/pkg/sentry/fsimpl/host" "gvisor.dev/gvisor/pkg/sentry/inet" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" @@ -46,9 +49,11 @@ import ( "gvisor.dev/gvisor/pkg/sentry/syscalls/linux/vfs2" "gvisor.dev/gvisor/pkg/sentry/time" "gvisor.dev/gvisor/pkg/sentry/usage" + "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/sentry/watchdog" "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/tcpip" + "gvisor.dev/gvisor/pkg/tcpip/link/loopback" "gvisor.dev/gvisor/pkg/tcpip/link/sniffer" "gvisor.dev/gvisor/pkg/tcpip/network/arp" "gvisor.dev/gvisor/pkg/tcpip/network/ipv4" @@ -60,6 +65,7 @@ import ( "gvisor.dev/gvisor/pkg/tcpip/transport/udp" "gvisor.dev/gvisor/runsc/boot/filter" _ "gvisor.dev/gvisor/runsc/boot/platforms" // register all platforms. + "gvisor.dev/gvisor/runsc/boot/pprof" "gvisor.dev/gvisor/runsc/specutils" // Include supported socket providers. @@ -137,6 +143,9 @@ type execProcess struct { // tty will be nil if the process is not attached to a terminal. tty *host.TTYFileOperations + // tty will be nil if the process is not attached to a terminal. + ttyVFS2 *hostvfs2.TTYFileDescription + // pidnsPath is the pid namespace path in spec pidnsPath string } @@ -154,13 +163,17 @@ type Args struct { Spec *specs.Spec // Conf is the system configuration. Conf *Config - // ControllerFD is the FD to the URPC controller. + // ControllerFD is the FD to the URPC controller. The Loader takes ownership + // of this FD and may close it at any time. ControllerFD int - // Device is an optional argument that is passed to the platform. + // Device is an optional argument that is passed to the platform. The Loader + // takes ownership of this file and may close it at any time. Device *os.File - // GoferFDs is an array of FDs used to connect with the Gofer. + // GoferFDs is an array of FDs used to connect with the Gofer. The Loader + // takes ownership of these FDs and may close them at any time. GoferFDs []int - // StdioFDs is the stdio for the application. + // StdioFDs is the stdio for the application. The Loader takes ownership of + // these FDs and may close them at any time. StdioFDs []int // Console is set to true if using TTY. Console bool @@ -173,6 +186,9 @@ type Args struct { UserLogFD int } +// make sure stdioFDs are always the same on initial start and on restore +const startingStdioFD = 64 + // New initializes a new kernel loader configured by spec. // New also handles setting up a kernel for restoring a container. func New(args Args) (*Loader, error) { @@ -186,11 +202,10 @@ func New(args Args) (*Loader, error) { return nil, fmt.Errorf("setting up memory usage: %v", err) } + // Is this a VFSv2 kernel? if args.Conf.VFS2 { - st, ok := kernel.LookupSyscallTable(abi.Linux, arch.Host) - if ok { - vfs2.Override(st.Table) - } + kernel.VFS2Enabled = true + vfs2.Override() } // Create kernel and platform. @@ -230,11 +245,8 @@ func New(args Args) (*Loader, error) { return nil, fmt.Errorf("enabling strace: %v", err) } - // Create an empty network stack because the network namespace may be empty at - // this point. Netns is configured before Run() is called. Netstack is - // configured using a control uRPC message. Host network is configured inside - // Run(). - networkStack, err := newEmptyNetworkStack(args.Conf, k, k) + // Create root network namespace/stack. + netns, err := newRootNetworkNamespace(args.Conf, k, k) if err != nil { return nil, fmt.Errorf("creating network: %v", err) } @@ -277,7 +289,7 @@ func New(args Args) (*Loader, error) { FeatureSet: cpuid.HostFeatureSet(), Timekeeper: tk, RootUserNamespace: creds.UserNamespace, - NetworkStack: networkStack, + RootNetworkNamespace: netns, ApplicationCores: uint(args.NumCPU), Vdso: vdso, RootUTSNamespace: kernel.NewUTSNamespace(args.Spec.Hostname, args.Spec.Hostname, creds.UserNamespace), @@ -320,6 +332,38 @@ func New(args Args) (*Loader, error) { return nil, fmt.Errorf("creating pod mount hints: %v", err) } + if kernel.VFS2Enabled { + // Set up host mount that will be used for imported fds. + hostFilesystem, err := hostvfs2.NewFilesystem(k.VFS()) + if err != nil { + return nil, fmt.Errorf("failed to create hostfs filesystem: %v", err) + } + defer hostFilesystem.DecRef() + hostMount, err := k.VFS().NewDisconnectedMount(hostFilesystem, nil, &vfs.MountOptions{}) + if err != nil { + return nil, fmt.Errorf("failed to create hostfs mount: %v", err) + } + k.SetHostMount(hostMount) + } + + // Make host FDs stable between invocations. Host FDs must map to the exact + // same number when the sandbox is restored. Otherwise the wrong FD will be + // used. + var stdioFDs []int + newfd := startingStdioFD + for _, fd := range args.StdioFDs { + err := syscall.Dup3(fd, newfd, syscall.O_CLOEXEC) + if err != nil { + return nil, fmt.Errorf("dup3 of stdioFDs failed: %v", err) + } + stdioFDs = append(stdioFDs, newfd) + err = syscall.Close(fd) + if err != nil { + return nil, fmt.Errorf("close original stdioFDs failed: %v", err) + } + newfd++ + } + eid := execID{cid: args.ID} l := &Loader{ k: k, @@ -328,7 +372,7 @@ func New(args Args) (*Loader, error) { watchdog: dog, spec: args.Spec, goferFDs: args.GoferFDs, - stdioFDs: args.StdioFDs, + stdioFDs: stdioFDs, rootProcArgs: procArgs, sandboxID: args.ID, processes: map[execID]*execProcess{eid: {}}, @@ -368,11 +412,16 @@ func newProcess(id string, spec *specs.Spec, creds *auth.Credentials, k *kernel. return kernel.CreateProcessArgs{}, fmt.Errorf("creating limits: %v", err) } + wd := spec.Process.Cwd + if wd == "" { + wd = "/" + } + // Create the process arguments. procArgs := kernel.CreateProcessArgs{ Argv: spec.Process.Args, Envv: spec.Process.Env, - WorkingDirectory: spec.Process.Cwd, // Defaults to '/' if empty. + WorkingDirectory: wd, Credentials: creds, Umask: 0022, Limits: ls, @@ -466,7 +515,7 @@ func (l *Loader) run() error { // Delay host network configuration to this point because network namespace // is configured after the loader is created and before Run() is called. log.Debugf("Configuring host network") - stack := l.k.NetworkStack().(*hostinet.Stack) + stack := l.k.RootNetworkNamespace().Stack().(*hostinet.Stack) if err := stack.Configure(); err != nil { return err } @@ -483,9 +532,11 @@ func (l *Loader) run() error { // If we are restoring, we do not want to create a process. // l.restore is set by the container manager when a restore call is made. + var ttyFile *host.TTYFileOperations + var ttyFileVFS2 *hostvfs2.TTYFileDescription if !l.restore { if l.conf.ProfileEnable { - initializePProf() + pprof.Initialize() } // Finally done with all configuration. Setup filters before user code @@ -497,13 +548,14 @@ func (l *Loader) run() error { // Create the FD map, which will set stdin, stdout, and stderr. If console // is true, then ioctl calls will be passed through to the host fd. ctx := l.rootProcArgs.NewContext(l.k) - fdTable, err := createFDTable(ctx, l.console, l.stdioFDs) + var err error + + // CreateProcess takes a reference on FDMap if successful. We won't need + // ours either way. + l.rootProcArgs.FDTable, ttyFile, ttyFileVFS2, err = createFDTable(ctx, l.console, l.stdioFDs) if err != nil { return fmt.Errorf("importing fds: %v", err) } - // CreateProcess takes a reference on FDMap if successful. We won't need - // ours either way. - l.rootProcArgs.FDTable = fdTable // Setup the root container file system. l.startGoferMonitor(l.sandboxID, l.goferFDs) @@ -517,7 +569,15 @@ func (l *Loader) run() error { } // Add the HOME enviroment variable if it is not already set. - envv, err := maybeAddExecUserHome(ctx, l.rootProcArgs.MountNamespace, l.rootProcArgs.Credentials.RealKUID, l.rootProcArgs.Envv) + var envv []string + if kernel.VFS2Enabled { + envv, err = user.MaybeAddExecUserHomeVFS2(ctx, l.rootProcArgs.MountNamespaceVFS2, + l.rootProcArgs.Credentials.RealKUID, l.rootProcArgs.Envv) + + } else { + envv, err = user.MaybeAddExecUserHome(ctx, l.rootProcArgs.MountNamespace, + l.rootProcArgs.Credentials.RealKUID, l.rootProcArgs.Envv) + } if err != nil { return err } @@ -538,14 +598,16 @@ func (l *Loader) run() error { ep.pidnsPath = ns.Path } if l.console { - ttyFile, _ := l.rootProcArgs.FDTable.Get(0) - defer ttyFile.DecRef() - ep.tty = ttyFile.FileOperations.(*host.TTYFileOperations) - - // Set the foreground process group on the TTY to the global - // init process group, since that is what we are about to - // start running. - ep.tty.InitForegroundProcessGroup(ep.tg.ProcessGroup()) + // Set the foreground process group on the TTY to the global init process + // group, since that is what we are about to start running. + switch { + case ttyFileVFS2 != nil: + ep.ttyVFS2 = ttyFileVFS2 + ttyFileVFS2.InitForegroundProcessGroup(ep.tg.ProcessGroup()) + case ttyFile != nil: + ep.tty = ttyFile + ttyFile.InitForegroundProcessGroup(ep.tg.ProcessGroup()) + } } // Handle signals by forwarding them to the root container process @@ -570,6 +632,19 @@ func (l *Loader) run() error { } }) + // l.stdioFDs are derived from dup() in boot.New() and they are now dup()ed again + // either in createFDTable() during initial start or in descriptor.initAfterLoad() + // during restore, we can release l.stdioFDs now. VFS2 takes ownership of the + // passed FDs, so only close for VFS1. + if !kernel.VFS2Enabled { + for _, fd := range l.stdioFDs { + err := syscall.Close(fd) + if err != nil { + return fmt.Errorf("close dup()ed stdioFDs: %v", err) + } + } + } + log.Infof("Process should have started...") l.watchdog.Start() return l.k.Start() @@ -653,7 +728,7 @@ func (l *Loader) startContainer(spec *specs.Spec, conf *Config, cid string, file // Create the FD map, which will set stdin, stdout, and stderr. ctx := procArgs.NewContext(l.k) - fdTable, err := createFDTable(ctx, false, stdioFDs) + fdTable, _, _, err := createFDTable(ctx, false, stdioFDs) if err != nil { return fmt.Errorf("importing fds: %v", err) } @@ -738,14 +813,14 @@ func (l *Loader) destroyContainer(cid string) error { l.mu.Lock() defer l.mu.Unlock() - _, _, started, err := l.threadGroupFromIDLocked(execID{cid: cid}) + tg, err := l.tryThreadGroupFromIDLocked(execID{cid: cid}) if err != nil { // Container doesn't exist. return err } - // The container exists, has it been started? - if started { + // The container exists, but has it been started? + if tg != nil { if err := l.signalAllProcesses(cid, int32(linux.SIGKILL)); err != nil { return fmt.Errorf("sending SIGKILL to all container processes: %v", err) } @@ -787,45 +862,65 @@ func (l *Loader) executeAsync(args *control.ExecArgs) (kernel.ThreadID, error) { l.mu.Lock() defer l.mu.Unlock() - tg, _, started, err := l.threadGroupFromIDLocked(execID{cid: args.ContainerID}) + tg, err := l.tryThreadGroupFromIDLocked(execID{cid: args.ContainerID}) if err != nil { return 0, err } - if !started { + if tg == nil { return 0, fmt.Errorf("container %q not started", args.ContainerID) } // Get the container MountNamespace from the Task. - tg.Leader().WithMuLocked(func(t *kernel.Task) { - // task.MountNamespace() does not take a ref, so we must do so - // ourselves. - args.MountNamespace = t.MountNamespace() - args.MountNamespace.IncRef() - }) - defer args.MountNamespace.DecRef() + if kernel.VFS2Enabled { + // task.MountNamespace() does not take a ref, so we must do so ourselves. + args.MountNamespaceVFS2 = tg.Leader().MountNamespaceVFS2() + args.MountNamespaceVFS2.IncRef() + } else { + tg.Leader().WithMuLocked(func(t *kernel.Task) { + // task.MountNamespace() does not take a ref, so we must do so ourselves. + args.MountNamespace = t.MountNamespace() + args.MountNamespace.IncRef() + }) + } - // Add the HOME enviroment varible if it is not already set. - root := args.MountNamespace.Root() - defer root.DecRef() - ctx := fs.WithRoot(l.k.SupervisorContext(), root) - envv, err := maybeAddExecUserHome(ctx, args.MountNamespace, args.KUID, args.Envv) - if err != nil { - return 0, err + // Add the HOME environment variable if it is not already set. + if kernel.VFS2Enabled { + defer args.MountNamespaceVFS2.DecRef() + + root := args.MountNamespaceVFS2.Root() + defer root.DecRef() + ctx := vfs.WithRoot(l.k.SupervisorContext(), root) + envv, err := user.MaybeAddExecUserHomeVFS2(ctx, args.MountNamespaceVFS2, args.KUID, args.Envv) + if err != nil { + return 0, err + } + args.Envv = envv + } else { + defer args.MountNamespace.DecRef() + + root := args.MountNamespace.Root() + defer root.DecRef() + ctx := fs.WithRoot(l.k.SupervisorContext(), root) + envv, err := user.MaybeAddExecUserHome(ctx, args.MountNamespace, args.KUID, args.Envv) + if err != nil { + return 0, err + } + args.Envv = envv } - args.Envv = envv // Start the process. proc := control.Proc{Kernel: l.k} args.PIDNamespace = tg.PIDNamespace() - newTG, tgid, ttyFile, err := control.ExecAsync(&proc, args) + newTG, tgid, ttyFile, ttyFileVFS2, err := control.ExecAsync(&proc, args) if err != nil { return 0, err } eid := execID{cid: args.ContainerID, pid: tgid} l.processes[eid] = &execProcess{ - tg: newTG, - tty: ttyFile, + tg: newTG, + tty: ttyFile, + ttyVFS2: ttyFileVFS2, } log.Debugf("updated processes: %v", l.processes) @@ -836,7 +931,7 @@ func (l *Loader) executeAsync(args *control.ExecArgs) (kernel.ThreadID, error) { func (l *Loader) waitContainer(cid string, waitStatus *uint32) error { // Don't defer unlock, as doing so would make it impossible for // multiple clients to wait on the same container. - tg, _, err := l.threadGroupFromID(execID{cid: cid}) + tg, err := l.threadGroupFromID(execID{cid: cid}) if err != nil { return fmt.Errorf("can't wait for container %q: %v", cid, err) } @@ -855,7 +950,7 @@ func (l *Loader) waitPID(tgid kernel.ThreadID, cid string, waitStatus *uint32) e // Try to find a process that was exec'd eid := execID{cid: cid, pid: tgid} - execTG, _, err := l.threadGroupFromID(eid) + execTG, err := l.threadGroupFromID(eid) if err == nil { ws := l.wait(execTG) *waitStatus = ws @@ -869,7 +964,7 @@ func (l *Loader) waitPID(tgid kernel.ThreadID, cid string, waitStatus *uint32) e // The caller may be waiting on a process not started directly via exec. // In this case, find the process in the container's PID namespace. - initTG, _, err := l.threadGroupFromID(execID{cid: cid}) + initTG, err := l.threadGroupFromID(execID{cid: cid}) if err != nil { return fmt.Errorf("waiting for PID %d: %v", tgid, err) } @@ -905,48 +1000,92 @@ func (l *Loader) WaitExit() kernel.ExitStatus { return l.k.GlobalInit().ExitStatus() } -func newEmptyNetworkStack(conf *Config, clock tcpip.Clock, uniqueID stack.UniqueID) (inet.Stack, error) { +func newRootNetworkNamespace(conf *Config, clock tcpip.Clock, uniqueID stack.UniqueID) (*inet.Namespace, error) { + // Create an empty network stack because the network namespace may be empty at + // this point. Netns is configured before Run() is called. Netstack is + // configured using a control uRPC message. Host network is configured inside + // Run(). switch conf.Network { case NetworkHost: - return hostinet.NewStack(), nil + // No network namespacing support for hostinet yet, hence creator is nil. + return inet.NewRootNamespace(hostinet.NewStack(), nil), nil case NetworkNone, NetworkSandbox: - // NetworkNone sets up loopback using netstack. - netProtos := []stack.NetworkProtocol{ipv4.NewProtocol(), ipv6.NewProtocol(), arp.NewProtocol()} - transProtos := []stack.TransportProtocol{tcp.NewProtocol(), udp.NewProtocol(), icmp.NewProtocol4()} - s := netstack.Stack{stack.New(stack.Options{ - NetworkProtocols: netProtos, - TransportProtocols: transProtos, - Clock: clock, - Stats: netstack.Metrics, - HandleLocal: true, - // Enable raw sockets for users with sufficient - // privileges. - RawFactory: raw.EndpointFactory{}, - UniqueID: uniqueID, - })} - - // Enable SACK Recovery. - if err := s.Stack.SetTransportProtocolOption(tcp.ProtocolNumber, tcp.SACKEnabled(true)); err != nil { - return nil, fmt.Errorf("failed to enable SACK: %v", err) + s, err := newEmptySandboxNetworkStack(clock, uniqueID) + if err != nil { + return nil, err + } + creator := &sandboxNetstackCreator{ + clock: clock, + uniqueID: uniqueID, } + return inet.NewRootNamespace(s, creator), nil - // Set default TTLs as required by socket/netstack. - s.Stack.SetNetworkProtocolOption(ipv4.ProtocolNumber, tcpip.DefaultTTLOption(netstack.DefaultTTL)) - s.Stack.SetNetworkProtocolOption(ipv6.ProtocolNumber, tcpip.DefaultTTLOption(netstack.DefaultTTL)) + default: + panic(fmt.Sprintf("invalid network configuration: %v", conf.Network)) + } - // Enable Receive Buffer Auto-Tuning. - if err := s.Stack.SetTransportProtocolOption(tcp.ProtocolNumber, tcpip.ModerateReceiveBufferOption(true)); err != nil { - return nil, fmt.Errorf("SetTransportProtocolOption failed: %v", err) - } +} + +func newEmptySandboxNetworkStack(clock tcpip.Clock, uniqueID stack.UniqueID) (inet.Stack, error) { + netProtos := []stack.NetworkProtocol{ipv4.NewProtocol(), ipv6.NewProtocol(), arp.NewProtocol()} + transProtos := []stack.TransportProtocol{tcp.NewProtocol(), udp.NewProtocol(), icmp.NewProtocol4()} + s := netstack.Stack{stack.New(stack.Options{ + NetworkProtocols: netProtos, + TransportProtocols: transProtos, + Clock: clock, + Stats: netstack.Metrics, + HandleLocal: true, + // Enable raw sockets for users with sufficient + // privileges. + RawFactory: raw.EndpointFactory{}, + UniqueID: uniqueID, + })} - s.FillDefaultIPTables() + // Enable SACK Recovery. + if err := s.Stack.SetTransportProtocolOption(tcp.ProtocolNumber, tcp.SACKEnabled(true)); err != nil { + return nil, fmt.Errorf("failed to enable SACK: %v", err) + } - return &s, nil + // Set default TTLs as required by socket/netstack. + s.Stack.SetNetworkProtocolOption(ipv4.ProtocolNumber, tcpip.DefaultTTLOption(netstack.DefaultTTL)) + s.Stack.SetNetworkProtocolOption(ipv6.ProtocolNumber, tcpip.DefaultTTLOption(netstack.DefaultTTL)) - default: - panic(fmt.Sprintf("invalid network configuration: %v", conf.Network)) + // Enable Receive Buffer Auto-Tuning. + if err := s.Stack.SetTransportProtocolOption(tcp.ProtocolNumber, tcpip.ModerateReceiveBufferOption(true)); err != nil { + return nil, fmt.Errorf("SetTransportProtocolOption failed: %v", err) + } + + s.FillIPTablesMetadata() + + return &s, nil +} + +// sandboxNetstackCreator implements kernel.NetworkStackCreator. +// +// +stateify savable +type sandboxNetstackCreator struct { + clock tcpip.Clock + uniqueID stack.UniqueID +} + +// CreateStack implements kernel.NetworkStackCreator.CreateStack. +func (f *sandboxNetstackCreator) CreateStack() (inet.Stack, error) { + s, err := newEmptySandboxNetworkStack(f.clock, f.uniqueID) + if err != nil { + return nil, err + } + + // Setup loopback. + n := &Network{Stack: s.(*netstack.Stack).Stack} + nicID := tcpip.NICID(f.uniqueID.UniqueID()) + link := DefaultLoopbackLink + linkEP := loopback.New() + if err := n.createNICWithAddrs(nicID, link.Name, linkEP, link.Addresses); err != nil { + return nil, err } + + return s, nil } // signal sends a signal to one or more processes in a container. If PID is 0, @@ -976,8 +1115,7 @@ func (l *Loader) signal(cid string, pid, signo int32, mode SignalDeliveryMode) e return fmt.Errorf("PID (%d) cannot be set when signaling all processes", pid) } // Check that the container has actually started before signaling it. - _, _, err := l.threadGroupFromID(execID{cid: cid}) - if err != nil { + if _, err := l.threadGroupFromID(execID{cid: cid}); err != nil { return err } if err := l.signalAllProcesses(cid, signo); err != nil { @@ -991,16 +1129,16 @@ func (l *Loader) signal(cid string, pid, signo int32, mode SignalDeliveryMode) e } func (l *Loader) signalProcess(cid string, tgid kernel.ThreadID, signo int32) error { - execTG, _, err := l.threadGroupFromID(execID{cid: cid, pid: tgid}) + execTG, err := l.threadGroupFromID(execID{cid: cid, pid: tgid}) if err == nil { // Send signal directly to the identified process. - return execTG.SendSignal(&arch.SignalInfo{Signo: signo}) + return l.k.SendExternalSignalThreadGroup(execTG, &arch.SignalInfo{Signo: signo}) } // The caller may be signaling a process not started directly via exec. // In this case, find the process in the container's PID namespace and // signal it. - initTG, _, err := l.threadGroupFromID(execID{cid: cid}) + initTG, err := l.threadGroupFromID(execID{cid: cid}) if err != nil { return fmt.Errorf("no thread group found: %v", err) } @@ -1011,25 +1149,43 @@ func (l *Loader) signalProcess(cid string, tgid kernel.ThreadID, signo int32) er if tg.Leader().ContainerID() != cid { return fmt.Errorf("process %d is part of a different container: %q", tgid, tg.Leader().ContainerID()) } - return tg.SendSignal(&arch.SignalInfo{Signo: signo}) + return l.k.SendExternalSignalThreadGroup(tg, &arch.SignalInfo{Signo: signo}) } +// signalForegrondProcessGroup looks up foreground process group from the TTY +// for the given "tgid" inside container "cid", and send the signal to it. func (l *Loader) signalForegrondProcessGroup(cid string, tgid kernel.ThreadID, signo int32) error { - // Lookup foreground process group from the TTY for the given process, - // and send the signal to it. - tg, tty, err := l.threadGroupFromID(execID{cid: cid, pid: tgid}) + l.mu.Lock() + tg, err := l.tryThreadGroupFromIDLocked(execID{cid: cid, pid: tgid}) if err != nil { + l.mu.Unlock() return fmt.Errorf("no thread group found: %v", err) } - if tty == nil { + if tg == nil { + l.mu.Unlock() + return fmt.Errorf("container %q not started", cid) + } + + tty, ttyVFS2, err := l.ttyFromIDLocked(execID{cid: cid, pid: tgid}) + l.mu.Unlock() + if err != nil { + return fmt.Errorf("no thread group found: %v", err) + } + + var pg *kernel.ProcessGroup + switch { + case ttyVFS2 != nil: + pg = ttyVFS2.ForegroundProcessGroup() + case tty != nil: + pg = tty.ForegroundProcessGroup() + default: return fmt.Errorf("no TTY attached") } - pg := tty.ForegroundProcessGroup() if pg == nil { // No foreground process group has been set. Signal the // original thread group. log.Warningf("No foreground process group for container %q and PID %d. Sending signal directly to PID %d.", cid, tgid, tgid) - return tg.SendSignal(&arch.SignalInfo{Signo: signo}) + return l.k.SendExternalSignalThreadGroup(tg, &arch.SignalInfo{Signo: signo}) } // Send the signal to all processes in the process group. var lastErr error @@ -1037,7 +1193,7 @@ func (l *Loader) signalForegrondProcessGroup(cid string, tgid kernel.ThreadID, s if tg.ProcessGroup() != pg { continue } - if err := tg.SendSignal(&arch.SignalInfo{Signo: signo}); err != nil { + if err := l.k.SendExternalSignalThreadGroup(tg, &arch.SignalInfo{Signo: signo}); err != nil { lastErr = err } } @@ -1055,33 +1211,57 @@ func (l *Loader) signalAllProcesses(cid string, signo int32) error { return l.k.SendContainerSignal(cid, &arch.SignalInfo{Signo: signo}) } -// threadGroupFromID same as threadGroupFromIDLocked except that it acquires -// mutex before calling it. -func (l *Loader) threadGroupFromID(key execID) (*kernel.ThreadGroup, *host.TTYFileOperations, error) { +// threadGroupFromID is similar to tryThreadGroupFromIDLocked except that it +// acquires mutex before calling it and fails in case container hasn't started +// yet. +func (l *Loader) threadGroupFromID(key execID) (*kernel.ThreadGroup, error) { l.mu.Lock() defer l.mu.Unlock() - tg, tty, ok, err := l.threadGroupFromIDLocked(key) + tg, err := l.tryThreadGroupFromIDLocked(key) if err != nil { - return nil, nil, err + return nil, err } - if !ok { - return nil, nil, fmt.Errorf("container %q not started", key.cid) + if tg == nil { + return nil, fmt.Errorf("container %q not started", key.cid) } - return tg, tty, nil + return tg, nil } -// threadGroupFromIDLocked returns the thread group and TTY for the given -// execution ID. TTY may be nil if the process is not attached to a terminal. -// Also returns a boolean indicating whether the container has already started. -// Returns error if execution ID is invalid or if the container cannot be -// found (maybe it has been deleted). Caller must hold 'mu'. -func (l *Loader) threadGroupFromIDLocked(key execID) (*kernel.ThreadGroup, *host.TTYFileOperations, bool, error) { +// tryThreadGroupFromIDLocked returns the thread group for the given execution +// ID. It may return nil in case the container has not started yet. Returns +// error if execution ID is invalid or if the container cannot be found (maybe +// it has been deleted). Caller must hold 'mu'. +func (l *Loader) tryThreadGroupFromIDLocked(key execID) (*kernel.ThreadGroup, error) { ep := l.processes[key] if ep == nil { - return nil, nil, false, fmt.Errorf("container %q not found", key.cid) + return nil, fmt.Errorf("container %q not found", key.cid) } - if ep.tg == nil { - return nil, nil, false, nil + return ep.tg, nil +} + +// ttyFromIDLocked returns the TTY files for the given execution ID. It may +// return nil in case the container has not started yet. Returns error if +// execution ID is invalid or if the container cannot be found (maybe it has +// been deleted). Caller must hold 'mu'. +func (l *Loader) ttyFromIDLocked(key execID) (*host.TTYFileOperations, *hostvfs2.TTYFileDescription, error) { + ep := l.processes[key] + if ep == nil { + return nil, nil, fmt.Errorf("container %q not found", key.cid) + } + return ep.tty, ep.ttyVFS2, nil +} + +func createFDTable(ctx context.Context, console bool, stdioFDs []int) (*kernel.FDTable, *host.TTYFileOperations, *hostvfs2.TTYFileDescription, error) { + if len(stdioFDs) != 3 { + return nil, nil, nil, fmt.Errorf("stdioFDs should contain exactly 3 FDs (stdin, stdout, and stderr), but %d FDs received", len(stdioFDs)) + } + + k := kernel.KernelFromContext(ctx) + fdTable := k.NewFDTable() + ttyFile, ttyFileVFS2, err := fdimport.Import(ctx, fdTable, console, stdioFDs) + if err != nil { + fdTable.DecRef() + return nil, nil, nil, err } - return ep.tg, ep.tty, true, nil + return fdTable, ttyFile, ttyFileVFS2, nil } diff --git a/runsc/boot/loader_amd64.go b/runsc/boot/loader_amd64.go deleted file mode 100644 index b9669f2ac..000000000 --- a/runsc/boot/loader_amd64.go +++ /dev/null @@ -1,27 +0,0 @@ -// 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. - -// +build amd64 - -package boot - -import ( - "gvisor.dev/gvisor/pkg/sentry/kernel" - "gvisor.dev/gvisor/pkg/sentry/syscalls/linux" -) - -func init() { - // Register the global syscall table. - kernel.RegisterSyscallTable(linux.AMD64) -} diff --git a/runsc/boot/loader_arm64.go b/runsc/boot/loader_arm64.go deleted file mode 100644 index cf64d28c8..000000000 --- a/runsc/boot/loader_arm64.go +++ /dev/null @@ -1,27 +0,0 @@ -// 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. - -// +build arm64 - -package boot - -import ( - "gvisor.dev/gvisor/pkg/sentry/kernel" - "gvisor.dev/gvisor/pkg/sentry/syscalls/linux" -) - -func init() { - // Register the global syscall table. - kernel.RegisterSyscallTable(linux.ARM64) -} diff --git a/runsc/boot/loader_test.go b/runsc/boot/loader_test.go index 44aa63196..e448fd773 100644 --- a/runsc/boot/loader_test.go +++ b/runsc/boot/loader_test.go @@ -24,11 +24,14 @@ import ( "time" specs "github.com/opencontainers/runtime-spec/specs-go" + "golang.org/x/sys/unix" "gvisor.dev/gvisor/pkg/control/server" + "gvisor.dev/gvisor/pkg/fspath" "gvisor.dev/gvisor/pkg/log" "gvisor.dev/gvisor/pkg/p9" "gvisor.dev/gvisor/pkg/sentry/contexttest" "gvisor.dev/gvisor/pkg/sentry/fs" + "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/unet" "gvisor.dev/gvisor/runsc/fsgofer" @@ -100,20 +103,29 @@ func startGofer(root string) (int, func(), error) { return sandboxEnd, cleanup, nil } -func createLoader() (*Loader, func(), error) { +func createLoader(vfsEnabled bool, spec *specs.Spec) (*Loader, func(), error) { fd, err := server.CreateSocket(ControlSocketAddr(fmt.Sprintf("%010d", rand.Int())[:10])) if err != nil { return nil, nil, err } conf := testConfig() - spec := testSpec() + conf.VFS2 = vfsEnabled sandEnd, cleanup, err := startGofer(spec.Root.Path) if err != nil { return nil, nil, err } - stdio := []int{int(os.Stdin.Fd()), int(os.Stdout.Fd()), int(os.Stderr.Fd())} + // Loader takes ownership of stdio. + var stdio []int + for _, f := range []*os.File{os.Stdin, os.Stdout, os.Stderr} { + newFd, err := unix.Dup(int(f.Fd())) + if err != nil { + return nil, nil, err + } + stdio = append(stdio, newFd) + } + args := Args{ ID: "foo", Spec: spec, @@ -132,10 +144,20 @@ func createLoader() (*Loader, func(), error) { // TestRun runs a simple application in a sandbox and checks that it succeeds. func TestRun(t *testing.T) { - l, cleanup, err := createLoader() + doRun(t, false) +} + +// TestRunVFS2 runs TestRun in VFSv2. +func TestRunVFS2(t *testing.T) { + doRun(t, true) +} + +func doRun(t *testing.T, vfsEnabled bool) { + l, cleanup, err := createLoader(vfsEnabled, testSpec()) if err != nil { t.Fatalf("error creating loader: %v", err) } + defer l.Destroy() defer cleanup() @@ -169,7 +191,16 @@ func TestRun(t *testing.T) { // TestStartSignal tests that the controller Start message will cause // WaitForStartSignal to return. func TestStartSignal(t *testing.T) { - l, cleanup, err := createLoader() + doStartSignal(t, false) +} + +// TestStartSignalVFS2 does TestStartSignal with VFS2. +func TestStartSignalVFS2(t *testing.T) { + doStartSignal(t, true) +} + +func doStartSignal(t *testing.T, vfsEnabled bool) { + l, cleanup, err := createLoader(vfsEnabled, testSpec()) if err != nil { t.Fatalf("error creating loader: %v", err) } @@ -217,18 +248,19 @@ func TestStartSignal(t *testing.T) { } -// Test that MountNamespace can be created with various specs. -func TestCreateMountNamespace(t *testing.T) { - testCases := []struct { - name string - // Spec that will be used to create the mount manager. Note - // that we can't mount procfs without a kernel, so each spec - // MUST contain something other than procfs mounted at /proc. - spec specs.Spec - // Paths that are expected to exist in the resulting fs. - expectedPaths []string - }{ - { +type CreateMountTestcase struct { + name string + // Spec that will be used to create the mount manager. Note + // that we can't mount procfs without a kernel, so each spec + // MUST contain something other than procfs mounted at /proc. + spec specs.Spec + // Paths that are expected to exist in the resulting fs. + expectedPaths []string +} + +func createMountTestcases(vfs2 bool) []*CreateMountTestcase { + testCases := []*CreateMountTestcase{ + &CreateMountTestcase{ // Only proc. name: "only proc mount", spec: specs.Spec{ @@ -270,7 +302,7 @@ func TestCreateMountNamespace(t *testing.T) { // /dev, and /sys. expectedPaths: []string{"/some/very/very/deep/path", "/proc", "/dev", "/sys"}, }, - { + &CreateMountTestcase{ // Mounts are nested inside each other. name: "nested mounts", spec: specs.Spec{ @@ -314,7 +346,7 @@ func TestCreateMountNamespace(t *testing.T) { expectedPaths: []string{"/foo", "/foo/bar", "/foo/bar/baz", "/foo/qux", "/foo/qux-quz", "/foo/some/very/very/deep/path", "/proc", "/dev", "/sys"}, }, - { + &CreateMountTestcase{ name: "mount inside /dev", spec: specs.Spec{ Root: &specs.Root{ @@ -357,40 +389,46 @@ func TestCreateMountNamespace(t *testing.T) { }, expectedPaths: []string{"/proc", "/dev", "/dev/fd-foo", "/dev/foo", "/dev/bar", "/sys"}, }, - { - name: "mounts inside mandatory mounts", - spec: specs.Spec{ - Root: &specs.Root{ - Path: os.TempDir(), - Readonly: true, + } + + vfsCase := &CreateMountTestcase{ + name: "mounts inside mandatory mounts", + spec: specs.Spec{ + Root: &specs.Root{ + Path: os.TempDir(), + Readonly: true, + }, + Mounts: []specs.Mount{ + { + Destination: "/proc", + Type: "tmpfs", }, - Mounts: []specs.Mount{ - { - Destination: "/proc", - Type: "tmpfs", - }, - // We don't include /sys, and /tmp in - // the spec, since they will be added - // automatically. - // - // Instead, add submounts inside these - // directories and make sure they are - // visible under the mandatory mounts. - { - Destination: "/sys/bar", - Type: "tmpfs", - }, - { - Destination: "/tmp/baz", - Type: "tmpfs", - }, + // TODO (gvisor.dev/issue/1487): Re-add this case when sysfs supports + // MkDirAt in VFS2 (and remove the reduntant append). + // { + // Destination: "/sys/bar", + // Type: "tmpfs", + // }, + // + { + Destination: "/tmp/baz", + Type: "tmpfs", }, }, - expectedPaths: []string{"/proc", "/sys", "/sys/bar", "/tmp", "/tmp/baz"}, }, + expectedPaths: []string{"/proc", "/sys" /* "/sys/bar" ,*/, "/tmp", "/tmp/baz"}, } - for _, tc := range testCases { + if !vfs2 { + vfsCase.spec.Mounts = append(vfsCase.spec.Mounts, specs.Mount{Destination: "/sys/bar", Type: "tmpfs"}) + vfsCase.expectedPaths = append(vfsCase.expectedPaths, "/sys/bar") + } + return append(testCases, vfsCase) +} + +// Test that MountNamespace can be created with various specs. +func TestCreateMountNamespace(t *testing.T) { + for _, tc := range createMountTestcases(false /* vfs2 */) { t.Run(tc.name, func(t *testing.T) { conf := testConfig() ctx := contexttest.Context(t) @@ -425,6 +463,52 @@ func TestCreateMountNamespace(t *testing.T) { } } +// Test that MountNamespace can be created with various specs. +func TestCreateMountNamespaceVFS2(t *testing.T) { + for _, tc := range createMountTestcases(true /* vfs2 */) { + t.Run(tc.name, func(t *testing.T) { + spec := testSpec() + spec.Mounts = tc.spec.Mounts + spec.Root = tc.spec.Root + + t.Logf("Using root: %q", spec.Root.Path) + l, loaderCleanup, err := createLoader(true /* VFS2 Enabled */, spec) + if err != nil { + t.Fatalf("failed to create loader: %v", err) + } + defer l.Destroy() + defer loaderCleanup() + + mntr := newContainerMounter(l.spec, l.goferFDs, l.k, l.mountHints) + if err := mntr.processHints(l.conf); err != nil { + t.Fatalf("failed process hints: %v", err) + } + + ctx := l.k.SupervisorContext() + mns, err := mntr.setupVFS2(ctx, l.conf, &l.rootProcArgs) + if err != nil { + t.Fatalf("failed to setupVFS2: %v", err) + } + + root := mns.Root() + defer root.DecRef() + for _, p := range tc.expectedPaths { + target := &vfs.PathOperation{ + Root: root, + Start: root, + Path: fspath.Parse(p), + } + + if d, err := l.k.VFS().GetDentryAt(ctx, l.rootProcArgs.Credentials, target, &vfs.GetDentryOptions{}); err != nil { + t.Errorf("expected path %v to exist with spec %v, but got error %v", p, tc.spec, err) + } else { + d.DecRef() + } + } + }) + } +} + // TestRestoreEnvironment tests that the correct mounts are collected from the spec and config // in order to build the environment for restoring. func TestRestoreEnvironment(t *testing.T) { diff --git a/runsc/boot/network.go b/runsc/boot/network.go index 6a8765ec8..0af30456e 100644 --- a/runsc/boot/network.go +++ b/runsc/boot/network.go @@ -17,12 +17,15 @@ package boot import ( "fmt" "net" + "runtime" + "strings" "syscall" "gvisor.dev/gvisor/pkg/log" "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/tcpip/link/fdbased" "gvisor.dev/gvisor/pkg/tcpip/link/loopback" + "gvisor.dev/gvisor/pkg/tcpip/link/qdisc/fifo" "gvisor.dev/gvisor/pkg/tcpip/link/sniffer" "gvisor.dev/gvisor/pkg/tcpip/network/arp" "gvisor.dev/gvisor/pkg/tcpip/network/ipv4" @@ -31,6 +34,32 @@ import ( "gvisor.dev/gvisor/pkg/urpc" ) +var ( + // DefaultLoopbackLink contains IP addresses and routes of "127.0.0.1/8" and + // "::1/8" on "lo" interface. + DefaultLoopbackLink = LoopbackLink{ + Name: "lo", + Addresses: []net.IP{ + net.IP("\x7f\x00\x00\x01"), + net.IPv6loopback, + }, + Routes: []Route{ + { + Destination: net.IPNet{ + IP: net.IPv4(0x7f, 0, 0, 0), + Mask: net.IPv4Mask(0xff, 0, 0, 0), + }, + }, + { + Destination: net.IPNet{ + IP: net.IPv6loopback, + Mask: net.IPMask(strings.Repeat("\xff", net.IPv6len)), + }, + }, + }, + } +) + // Network exposes methods that can be used to configure a network stack. type Network struct { Stack *stack.Stack @@ -48,6 +77,44 @@ type DefaultRoute struct { Name string } +// QueueingDiscipline is used to specify the kind of Queueing Discipline to +// apply for a give FDBasedLink. +type QueueingDiscipline int + +const ( + // QDiscNone disables any queueing for the underlying FD. + QDiscNone QueueingDiscipline = iota + + // QDiscFIFO applies a simple fifo based queue to the underlying + // FD. + QDiscFIFO +) + +// MakeQueueingDiscipline if possible the equivalent QueuingDiscipline for s +// else returns an error. +func MakeQueueingDiscipline(s string) (QueueingDiscipline, error) { + switch s { + case "none": + return QDiscNone, nil + case "fifo": + return QDiscFIFO, nil + default: + return 0, fmt.Errorf("unsupported qdisc specified: %q", s) + } +} + +// String implements fmt.Stringer. +func (q QueueingDiscipline) String() string { + switch q { + case QDiscNone: + return "none" + case QDiscFIFO: + return "fifo" + default: + panic(fmt.Sprintf("Invalid queueing discipline: %d", q)) + } +} + // FDBasedLink configures an fd-based link. type FDBasedLink struct { Name string @@ -57,6 +124,7 @@ type FDBasedLink struct { GSOMaxSize uint32 SoftwareGSOEnabled bool LinkAddress net.HardwareAddr + QDisc QueueingDiscipline // NumChannels controls how many underlying FD's are to be used to // create this endpoint. @@ -158,6 +226,8 @@ func (n *Network) CreateLinksAndRoutes(args *CreateLinksAndRoutesArgs, _ *struct } mac := tcpip.LinkAddress(link.LinkAddress) + log.Infof("gso max size is: %d", link.GSOMaxSize) + linkEP, err := fdbased.New(&fdbased.Options{ FDs: FDs, MTU: uint32(link.MTU), @@ -172,6 +242,13 @@ func (n *Network) CreateLinksAndRoutes(args *CreateLinksAndRoutesArgs, _ *struct return err } + switch link.QDisc { + case QDiscNone: + case QDiscFIFO: + log.Infof("Enabling FIFO QDisc on %q", link.Name) + linkEP = fifo.New(linkEP, runtime.GOMAXPROCS(0), 1000) + } + log.Infof("Enabling interface %q with id %d on addresses %+v (%v) w/ %d channels", link.Name, nicID, link.Addresses, mac, link.NumChannels) if err := n.createNICWithAddrs(nicID, link.Name, linkEP, link.Addresses); err != nil { return err diff --git a/runsc/boot/pprof/BUILD b/runsc/boot/pprof/BUILD new file mode 100644 index 000000000..29cb42b2f --- /dev/null +++ b/runsc/boot/pprof/BUILD @@ -0,0 +1,11 @@ +load("//tools:defs.bzl", "go_library") + +package(licenses = ["notice"]) + +go_library( + name = "pprof", + srcs = ["pprof.go"], + visibility = [ + "//runsc:__subpackages__", + ], +) diff --git a/runsc/boot/pprof.go b/runsc/boot/pprof/pprof.go index 463362f02..1ded20dee 100644 --- a/runsc/boot/pprof.go +++ b/runsc/boot/pprof/pprof.go @@ -12,7 +12,9 @@ // See the License for the specific language governing permissions and // limitations under the License. -package boot +// Package pprof provides a stub to initialize custom profilers. +package pprof -func initializePProf() { +// Initialize will be called at boot for initializing custom profilers. +func Initialize() { } diff --git a/runsc/boot/user.go b/runsc/boot/user.go deleted file mode 100644 index f0aa52135..000000000 --- a/runsc/boot/user.go +++ /dev/null @@ -1,170 +0,0 @@ -// 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 boot - -import ( - "bufio" - "fmt" - "io" - "strconv" - "strings" - - "gvisor.dev/gvisor/pkg/abi/linux" - "gvisor.dev/gvisor/pkg/context" - "gvisor.dev/gvisor/pkg/sentry/fs" - "gvisor.dev/gvisor/pkg/sentry/kernel/auth" - "gvisor.dev/gvisor/pkg/usermem" -) - -type fileReader struct { - // Ctx is the context for the file reader. - Ctx context.Context - - // File is the file to read from. - File *fs.File -} - -// Read implements io.Reader.Read. -func (r *fileReader) Read(buf []byte) (int, error) { - n, err := r.File.Readv(r.Ctx, usermem.BytesIOSequence(buf)) - return int(n), err -} - -// getExecUserHome returns the home directory of the executing user read from -// /etc/passwd as read from the container filesystem. -func getExecUserHome(ctx context.Context, rootMns *fs.MountNamespace, uid auth.KUID) (string, error) { - // The default user home directory to return if no user matching the user - // if found in the /etc/passwd found in the image. - const defaultHome = "/" - - // Open the /etc/passwd file from the dirent via the root mount namespace. - mnsRoot := rootMns.Root() - maxTraversals := uint(linux.MaxSymlinkTraversals) - dirent, err := rootMns.FindInode(ctx, mnsRoot, nil, "/etc/passwd", &maxTraversals) - if err != nil { - // NOTE: Ignore errors opening the passwd file. If the passwd file - // doesn't exist we will return the default home directory. - return defaultHome, nil - } - defer dirent.DecRef() - - // Check read permissions on the file. - if err := dirent.Inode.CheckPermission(ctx, fs.PermMask{Read: true}); err != nil { - // NOTE: Ignore permissions errors here and return default root dir. - return defaultHome, nil - } - - // Only open regular files. We don't open other files like named pipes as - // they may block and might present some attack surface to the container. - // Note that runc does not seem to do this kind of checking. - if !fs.IsRegular(dirent.Inode.StableAttr) { - return defaultHome, nil - } - - f, err := dirent.Inode.GetFile(ctx, dirent, fs.FileFlags{Read: true, Directory: false}) - if err != nil { - return "", err - } - defer f.DecRef() - - r := &fileReader{ - Ctx: ctx, - File: f, - } - - homeDir, err := findHomeInPasswd(uint32(uid), r, defaultHome) - if err != nil { - return "", err - } - - return homeDir, nil -} - -// maybeAddExecUserHome returns a new slice with the HOME enviroment variable -// set if the slice does not already contain it, otherwise it returns the -// original slice unmodified. -func maybeAddExecUserHome(ctx context.Context, mns *fs.MountNamespace, uid auth.KUID, envv []string) ([]string, error) { - // Check if the envv already contains HOME. - for _, env := range envv { - if strings.HasPrefix(env, "HOME=") { - // We have it. Return the original slice unmodified. - return envv, nil - } - } - - // Read /etc/passwd for the user's HOME directory and set the HOME - // environment variable as required by POSIX if it is not overridden by - // the user. - homeDir, err := getExecUserHome(ctx, mns, uid) - if err != nil { - return nil, fmt.Errorf("error reading exec user: %v", err) - } - return append(envv, "HOME="+homeDir), nil -} - -// findHomeInPasswd parses a passwd file and returns the given user's home -// directory. This function does it's best to replicate the runc's behavior. -func findHomeInPasswd(uid uint32, passwd io.Reader, defaultHome string) (string, error) { - s := bufio.NewScanner(passwd) - - for s.Scan() { - if err := s.Err(); err != nil { - return "", err - } - - line := strings.TrimSpace(s.Text()) - if line == "" { - continue - } - - // Pull out part of passwd entry. Loosely parse the passwd entry as some - // passwd files could be poorly written and for compatibility with runc. - // - // Per 'man 5 passwd' - // /etc/passwd contains one line for each user account, with seven - // fields delimited by colons (“:”). These fields are: - // - // - login name - // - optional encrypted password - // - numerical user ID - // - numerical group ID - // - user name or comment field - // - user home directory - // - optional user command interpreter - parts := strings.Split(line, ":") - - found := false - homeDir := "" - for i, p := range parts { - switch i { - case 2: - parsedUID, err := strconv.ParseUint(p, 10, 32) - if err == nil && parsedUID == uint64(uid) { - found = true - } - case 5: - homeDir = p - } - } - if found { - // NOTE: If the uid is present but the home directory is not - // present in the /etc/passwd entry we return an empty string. This - // is, for better or worse, what runc does. - return homeDir, nil - } - } - - return defaultHome, nil -} diff --git a/runsc/boot/user_test.go b/runsc/boot/user_test.go deleted file mode 100644 index fb4e13dfb..000000000 --- a/runsc/boot/user_test.go +++ /dev/null @@ -1,254 +0,0 @@ -// 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 boot - -import ( - "io/ioutil" - "os" - "path/filepath" - "strings" - "syscall" - "testing" - - specs "github.com/opencontainers/runtime-spec/specs-go" - "gvisor.dev/gvisor/pkg/sentry/contexttest" - "gvisor.dev/gvisor/pkg/sentry/fs" - "gvisor.dev/gvisor/pkg/sentry/kernel/auth" -) - -func setupTempDir() (string, error) { - tmpDir, err := ioutil.TempDir(os.TempDir(), "exec-user-test") - if err != nil { - return "", err - } - return tmpDir, nil -} - -func setupPasswd(contents string, perms os.FileMode) func() (string, error) { - return func() (string, error) { - tmpDir, err := setupTempDir() - if err != nil { - return "", err - } - - if err := os.Mkdir(filepath.Join(tmpDir, "etc"), 0777); err != nil { - return "", err - } - - f, err := os.Create(filepath.Join(tmpDir, "etc", "passwd")) - if err != nil { - return "", err - } - defer f.Close() - - _, err = f.WriteString(contents) - if err != nil { - return "", err - } - - err = f.Chmod(perms) - if err != nil { - return "", err - } - return tmpDir, nil - } -} - -// TestGetExecUserHome tests the getExecUserHome function. -func TestGetExecUserHome(t *testing.T) { - tests := map[string]struct { - uid auth.KUID - createRoot func() (string, error) - expected string - }{ - "success": { - uid: 1000, - createRoot: setupPasswd("adin::1000:1111::/home/adin:/bin/sh", 0666), - expected: "/home/adin", - }, - "no_passwd": { - uid: 1000, - createRoot: setupTempDir, - expected: "/", - }, - "no_perms": { - uid: 1000, - createRoot: setupPasswd("adin::1000:1111::/home/adin:/bin/sh", 0000), - expected: "/", - }, - "directory": { - uid: 1000, - createRoot: func() (string, error) { - tmpDir, err := setupTempDir() - if err != nil { - return "", err - } - - if err := os.Mkdir(filepath.Join(tmpDir, "etc"), 0777); err != nil { - return "", err - } - - if err := syscall.Mkdir(filepath.Join(tmpDir, "etc", "passwd"), 0666); err != nil { - return "", err - } - - return tmpDir, nil - }, - expected: "/", - }, - // Currently we don't allow named pipes. - "named_pipe": { - uid: 1000, - createRoot: func() (string, error) { - tmpDir, err := setupTempDir() - if err != nil { - return "", err - } - - if err := os.Mkdir(filepath.Join(tmpDir, "etc"), 0777); err != nil { - return "", err - } - - if err := syscall.Mkfifo(filepath.Join(tmpDir, "etc", "passwd"), 0666); err != nil { - return "", err - } - - return tmpDir, nil - }, - expected: "/", - }, - } - - for name, tc := range tests { - t.Run(name, func(t *testing.T) { - tmpDir, err := tc.createRoot() - if err != nil { - t.Fatalf("failed to create root dir: %v", err) - } - - sandEnd, cleanup, err := startGofer(tmpDir) - if err != nil { - t.Fatalf("failed to create gofer: %v", err) - } - defer cleanup() - - ctx := contexttest.Context(t) - conf := &Config{ - RootDir: "unused_root_dir", - Network: NetworkNone, - DisableSeccomp: true, - } - - spec := &specs.Spec{ - Root: &specs.Root{ - Path: tmpDir, - Readonly: true, - }, - // Add /proc mount as tmpfs to avoid needing a kernel. - Mounts: []specs.Mount{ - { - Destination: "/proc", - Type: "tmpfs", - }, - }, - } - - mntr := newContainerMounter(spec, []int{sandEnd}, nil, &podMountHints{}) - mns, err := mntr.createMountNamespace(ctx, conf) - if err != nil { - t.Fatalf("failed to create mount namespace: %v", err) - } - ctx = fs.WithRoot(ctx, mns.Root()) - if err := mntr.mountSubmounts(ctx, conf, mns); err != nil { - t.Fatalf("failed to create mount namespace: %v", err) - } - - got, err := getExecUserHome(ctx, mns, tc.uid) - if err != nil { - t.Fatalf("failed to get user home: %v", err) - } - - if got != tc.expected { - t.Fatalf("expected %v, got: %v", tc.expected, got) - } - }) - } -} - -// TestFindHomeInPasswd tests the findHomeInPasswd function's passwd file parsing. -func TestFindHomeInPasswd(t *testing.T) { - tests := map[string]struct { - uid uint32 - passwd string - expected string - def string - }{ - "empty": { - uid: 1000, - passwd: "", - expected: "/", - def: "/", - }, - "whitespace": { - uid: 1000, - passwd: " ", - expected: "/", - def: "/", - }, - "full": { - uid: 1000, - passwd: "adin::1000:1111::/home/adin:/bin/sh", - expected: "/home/adin", - def: "/", - }, - // For better or worse, this is how runc works. - "partial": { - uid: 1000, - passwd: "adin::1000:1111:", - expected: "", - def: "/", - }, - "multiple": { - uid: 1001, - passwd: "adin::1000:1111::/home/adin:/bin/sh\nian::1001:1111::/home/ian:/bin/sh", - expected: "/home/ian", - def: "/", - }, - "duplicate": { - uid: 1000, - passwd: "adin::1000:1111::/home/adin:/bin/sh\nian::1000:1111::/home/ian:/bin/sh", - expected: "/home/adin", - def: "/", - }, - "empty_lines": { - uid: 1001, - passwd: "adin::1000:1111::/home/adin:/bin/sh\n\n\nian::1001:1111::/home/ian:/bin/sh", - expected: "/home/ian", - def: "/", - }, - } - - for name, tc := range tests { - t.Run(name, func(t *testing.T) { - got, err := findHomeInPasswd(tc.uid, strings.NewReader(tc.passwd), tc.def) - if err != nil { - t.Fatalf("error parsing passwd: %v", err) - } - if tc.expected != got { - t.Fatalf("expected %v, got: %v", tc.expected, got) - } - }) - } -} diff --git a/runsc/boot/vfs.go b/runsc/boot/vfs.go new file mode 100644 index 000000000..7ed6801b4 --- /dev/null +++ b/runsc/boot/vfs.go @@ -0,0 +1,375 @@ +// Copyright 2018 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 boot + +import ( + "fmt" + "path" + "sort" + "strings" + + specs "github.com/opencontainers/runtime-spec/specs-go" + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/fspath" + "gvisor.dev/gvisor/pkg/log" + "gvisor.dev/gvisor/pkg/sentry/devices/memdev" + "gvisor.dev/gvisor/pkg/sentry/fs/user" + "gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts" + "gvisor.dev/gvisor/pkg/sentry/fsimpl/devtmpfs" + "gvisor.dev/gvisor/pkg/sentry/fsimpl/gofer" + "gvisor.dev/gvisor/pkg/sentry/fsimpl/proc" + "gvisor.dev/gvisor/pkg/sentry/fsimpl/sys" + "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/vfs" + "gvisor.dev/gvisor/pkg/syserror" +) + +func registerFilesystems(ctx context.Context, vfsObj *vfs.VirtualFilesystem, creds *auth.Credentials) error { + vfsObj.MustRegisterFilesystemType(devpts.Name, &devpts.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{ + AllowUserList: true, + // TODO(b/29356795): Users may mount this once the terminals are in a + // usable state. + AllowUserMount: false, + }) + vfsObj.MustRegisterFilesystemType(devtmpfs.Name, &devtmpfs.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{ + AllowUserMount: true, + AllowUserList: true, + }) + vfsObj.MustRegisterFilesystemType(gofer.Name, &gofer.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{ + AllowUserList: true, + }) + vfsObj.MustRegisterFilesystemType(proc.Name, &proc.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{ + AllowUserMount: true, + AllowUserList: true, + }) + vfsObj.MustRegisterFilesystemType(sys.Name, &sys.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{ + AllowUserMount: true, + AllowUserList: true, + }) + vfsObj.MustRegisterFilesystemType(tmpfs.Name, &tmpfs.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{ + AllowUserMount: true, + AllowUserList: true, + }) + + // Setup files in devtmpfs. + if err := memdev.Register(vfsObj); err != nil { + return fmt.Errorf("registering memdev: %w", err) + } + a, err := devtmpfs.NewAccessor(ctx, vfsObj, creds, devtmpfs.Name) + if err != nil { + return fmt.Errorf("creating devtmpfs accessor: %w", err) + } + defer a.Release() + + if err := a.UserspaceInit(ctx); err != nil { + return fmt.Errorf("initializing userspace: %w", err) + } + if err := memdev.CreateDevtmpfsFiles(ctx, a); err != nil { + return fmt.Errorf("creating devtmpfs files: %w", err) + } + return nil +} + +func setupContainerVFS2(ctx context.Context, conf *Config, mntr *containerMounter, procArgs *kernel.CreateProcessArgs) error { + if err := mntr.k.VFS().Init(); err != nil { + return fmt.Errorf("failed to initialize VFS: %w", err) + } + mns, err := mntr.setupVFS2(ctx, conf, procArgs) + if err != nil { + return fmt.Errorf("failed to setupFS: %w", err) + } + procArgs.MountNamespaceVFS2 = mns + + // Resolve the executable path from working dir and environment. + f, err := user.ResolveExecutablePathVFS2(ctx, procArgs.Credentials, procArgs.MountNamespaceVFS2, procArgs.Envv, procArgs.WorkingDirectory, procArgs.Argv[0]) + if err != nil { + return fmt.Errorf("searching for executable %q, cwd: %q, envv: %q: %v", procArgs.Argv[0], procArgs.WorkingDirectory, procArgs.Envv, err) + } + procArgs.Filename = f + return nil +} + +func (c *containerMounter) setupVFS2(ctx context.Context, conf *Config, procArgs *kernel.CreateProcessArgs) (*vfs.MountNamespace, error) { + log.Infof("Configuring container's file system with VFS2") + + // Create context with root credentials to mount the filesystem (the current + // user may not be privileged enough). + rootCreds := auth.NewRootCredentials(procArgs.Credentials.UserNamespace) + rootProcArgs := *procArgs + rootProcArgs.WorkingDirectory = "/" + rootProcArgs.Credentials = rootCreds + rootProcArgs.Umask = 0022 + rootProcArgs.MaxSymlinkTraversals = linux.MaxSymlinkTraversals + rootCtx := procArgs.NewContext(c.k) + + if err := registerFilesystems(rootCtx, c.k.VFS(), rootCreds); err != nil { + return nil, fmt.Errorf("register filesystems: %w", err) + } + + mns, err := c.createMountNamespaceVFS2(rootCtx, conf, rootCreds) + if err != nil { + return nil, fmt.Errorf("creating mount namespace: %w", err) + } + rootProcArgs.MountNamespaceVFS2 = mns + + // Mount submounts. + if err := c.mountSubmountsVFS2(rootCtx, conf, mns, rootCreds); err != nil { + return nil, fmt.Errorf("mounting submounts vfs2: %w", err) + } + return mns, nil +} + +func (c *containerMounter) createMountNamespaceVFS2(ctx context.Context, conf *Config, creds *auth.Credentials) (*vfs.MountNamespace, error) { + fd := c.fds.remove() + opts := strings.Join(p9MountData(fd, conf.FileAccess, true /* vfs2 */), ",") + + log.Infof("Mounting root over 9P, ioFD: %d", fd) + mns, err := c.k.VFS().NewMountNamespace(ctx, creds, "", gofer.Name, &vfs.GetFilesystemOptions{Data: opts}) + if err != nil { + return nil, fmt.Errorf("setting up mount namespace: %w", err) + } + return mns, nil +} + +func (c *containerMounter) mountSubmountsVFS2(ctx context.Context, conf *Config, mns *vfs.MountNamespace, creds *auth.Credentials) error { + mounts, err := c.prepareMountsVFS2() + if err != nil { + return err + } + + for i := range mounts { + submount := &mounts[i] + log.Debugf("Mounting %q to %q, type: %s, options: %s", submount.Source, submount.Destination, submount.Type, submount.Options) + if err := c.mountSubmountVFS2(ctx, conf, mns, creds, submount); err != nil { + return err + } + } + + if err := c.mountTmpVFS2(ctx, conf, creds, mns); err != nil { + return fmt.Errorf(`mount submount "\tmp": %w`, err) + } + return nil +} + +type mountAndFD struct { + specs.Mount + fd int +} + +func (c *containerMounter) prepareMountsVFS2() ([]mountAndFD, error) { + // Associate bind mounts with their FDs before sorting since there is an + // undocumented assumption that FDs are dispensed in the order in which + // they are required by mounts. + var mounts []mountAndFD + for _, m := range c.mounts { + fd := -1 + // Only bind mounts use host FDs; see + // containerMounter.getMountNameAndOptionsVFS2. + if m.Type == bind { + fd = c.fds.remove() + } + mounts = append(mounts, mountAndFD{ + Mount: m, + fd: fd, + }) + } + if err := c.checkDispenser(); err != nil { + return nil, err + } + + // Sort the mounts so that we don't place children before parents. + sort.Slice(mounts, func(i, j int) bool { + return len(mounts[i].Destination) < len(mounts[j].Destination) + }) + + return mounts, nil +} + +func (c *containerMounter) mountSubmountVFS2(ctx context.Context, conf *Config, mns *vfs.MountNamespace, creds *auth.Credentials, submount *mountAndFD) error { + root := mns.Root() + defer root.DecRef() + target := &vfs.PathOperation{ + Root: root, + Start: root, + Path: fspath.Parse(submount.Destination), + } + fsName, opts, err := c.getMountNameAndOptionsVFS2(conf, submount) + if err != nil { + return fmt.Errorf("mountOptions failed: %w", err) + } + if len(fsName) == 0 { + // Filesystem is not supported (e.g. cgroup), just skip it. + return nil + } + + if err := c.makeSyntheticMount(ctx, submount.Destination, root, creds); err != nil { + return err + } + if err := c.k.VFS().MountAt(ctx, creds, "", target, fsName, opts); err != nil { + return fmt.Errorf("failed to mount %q (type: %s): %w, opts: %v", submount.Destination, submount.Type, err, opts) + } + log.Infof("Mounted %q to %q type: %s, internal-options: %q", submount.Source, submount.Destination, submount.Type, opts.GetFilesystemOptions.Data) + return nil +} + +// getMountNameAndOptionsVFS2 retrieves the fsName, opts, and useOverlay values +// used for mounts. +func (c *containerMounter) getMountNameAndOptionsVFS2(conf *Config, m *mountAndFD) (string, *vfs.MountOptions, error) { + var ( + fsName string + data []string + ) + + // Find filesystem name and FS specific data field. + switch m.Type { + case devpts.Name, devtmpfs.Name, proc.Name, sys.Name: + fsName = m.Type + case nonefs: + fsName = sys.Name + case tmpfs.Name: + fsName = m.Type + + var err error + data, err = parseAndFilterOptions(m.Options, tmpfsAllowedData...) + if err != nil { + return "", nil, err + } + + case bind: + fsName = gofer.Name + data = p9MountData(m.fd, c.getMountAccessType(m.Mount), true /* vfs2 */) + + default: + log.Warningf("ignoring unknown filesystem type %q", m.Type) + } + + opts := &vfs.MountOptions{ + GetFilesystemOptions: vfs.GetFilesystemOptions{ + Data: strings.Join(data, ","), + }, + InternalMount: true, + } + + for _, o := range m.Options { + switch o { + case "rw": + opts.ReadOnly = false + case "ro": + opts.ReadOnly = true + case "noatime": + opts.Flags.NoATime = true + case "noexec": + opts.Flags.NoExec = true + default: + log.Warningf("ignoring unknown mount option %q", o) + } + } + + if conf.Overlay { + // All writes go to upper, be paranoid and make lower readonly. + opts.ReadOnly = true + } + return fsName, opts, nil +} + +func (c *containerMounter) makeSyntheticMount(ctx context.Context, currentPath string, root vfs.VirtualDentry, creds *auth.Credentials) error { + target := &vfs.PathOperation{ + Root: root, + Start: root, + Path: fspath.Parse(currentPath), + } + _, err := c.k.VFS().StatAt(ctx, creds, target, &vfs.StatOptions{}) + if err == nil { + // Mount point exists, nothing else to do. + return nil + } + if err != syserror.ENOENT { + return fmt.Errorf("stat failed for %q during mount point creation: %w", currentPath, err) + } + + // Recurse to ensure parent is created and then create the mount point. + if err := c.makeSyntheticMount(ctx, path.Dir(currentPath), root, creds); err != nil { + return err + } + log.Debugf("Creating dir %q for mount point", currentPath) + mkdirOpts := &vfs.MkdirOptions{Mode: 0777, ForSyntheticMountpoint: true} + if err := c.k.VFS().MkdirAt(ctx, creds, target, mkdirOpts); err != nil { + return fmt.Errorf("failed to create directory %q for mount: %w", currentPath, err) + } + return nil +} + +// mountTmpVFS2 mounts an internal tmpfs at '/tmp' if it's safe to do so. +// Technically we don't have to mount tmpfs at /tmp, as we could just rely on +// the host /tmp, but this is a nice optimization, and fixes some apps that call +// mknod in /tmp. It's unsafe to mount tmpfs if: +// 1. /tmp is mounted explicitly: we should not override user's wish +// 2. /tmp is not empty: mounting tmpfs would hide existing files in /tmp +// +// Note that when there are submounts inside of '/tmp', directories for the +// mount points must be present, making '/tmp' not empty anymore. +func (c *containerMounter) mountTmpVFS2(ctx context.Context, conf *Config, creds *auth.Credentials, mns *vfs.MountNamespace) error { + for _, m := range c.mounts { + // m.Destination has been cleaned, so it's to use equality here. + if m.Destination == "/tmp" { + log.Debugf(`Explict "/tmp" mount found, skipping internal tmpfs, mount: %+v`, m) + return nil + } + } + + root := mns.Root() + defer root.DecRef() + pop := vfs.PathOperation{ + Root: root, + Start: root, + Path: fspath.Parse("/tmp"), + } + // TODO(gvisor.dev/issue/2782): Use O_PATH when available. + statx, err := c.k.VFS().StatAt(ctx, creds, &pop, &vfs.StatOptions{}) + switch err { + case nil: + // Found '/tmp' in filesystem, check if it's empty. + if linux.FileMode(statx.Mode).FileType() != linux.ModeDirectory { + // Not a dir?! Leave it be. + return nil + } + if statx.Nlink > 2 { + // If more than "." and ".." is found, skip internal tmpfs to prevent + // hiding existing files. + log.Infof(`Skipping internal tmpfs mount for "/tmp" because it's not empty`) + return nil + } + log.Infof(`Mounting internal tmpfs on top of empty "/tmp"`) + fallthrough + + case syserror.ENOENT: + // No '/tmp' found (or fallthrough from above). It's safe to mount internal + // tmpfs. + tmpMount := specs.Mount{ + Type: tmpfs.Name, + Destination: "/tmp", + // Sticky bit is added to prevent accidental deletion of files from + // another user. This is normally done for /tmp. + Options: []string{"mode=01777"}, + } + return c.mountSubmountVFS2(ctx, conf, mns, creds, &mountAndFD{Mount: tmpMount}) + + default: + return fmt.Errorf(`stating "/tmp" inside container: %w`, err) + } +} |