diff options
Diffstat (limited to 'pkg/sentry')
-rw-r--r-- | pkg/sentry/fsimpl/memfs/BUILD | 20 | ||||
-rw-r--r-- | pkg/sentry/fsimpl/memfs/filesystem.go | 55 | ||||
-rw-r--r-- | pkg/sentry/fsimpl/memfs/memfs.go | 2 | ||||
-rw-r--r-- | pkg/sentry/fsimpl/memfs/named_pipe.go | 59 | ||||
-rw-r--r-- | pkg/sentry/fsimpl/memfs/pipe_test.go | 233 | ||||
-rw-r--r-- | pkg/sentry/kernel/pipe/vfs.go | 2 | ||||
-rw-r--r-- | pkg/sentry/platform/ptrace/subprocess.go | 16 | ||||
-rw-r--r-- | pkg/sentry/platform/ptrace/subprocess_linux.go | 3 | ||||
-rw-r--r-- | pkg/sentry/socket/netstack/netstack.go | 40 | ||||
-rw-r--r-- | pkg/sentry/socket/netstack/provider.go | 53 | ||||
-rw-r--r-- | pkg/sentry/syscalls/linux/linux64.go | 11 | ||||
-rw-r--r-- | pkg/sentry/syscalls/linux/linux64_amd64.go | 8 | ||||
-rw-r--r-- | pkg/sentry/syscalls/linux/linux64_arm64.go | 6 | ||||
-rw-r--r-- | pkg/sentry/syscalls/linux/sys_thread.go | 48 | ||||
-rw-r--r-- | pkg/sentry/syscalls/linux/sys_write.go | 1 | ||||
-rw-r--r-- | pkg/sentry/vfs/syscalls.go | 22 |
16 files changed, 542 insertions, 37 deletions
diff --git a/pkg/sentry/fsimpl/memfs/BUILD b/pkg/sentry/fsimpl/memfs/BUILD index 7e364c5fd..04d667273 100644 --- a/pkg/sentry/fsimpl/memfs/BUILD +++ b/pkg/sentry/fsimpl/memfs/BUILD @@ -24,14 +24,18 @@ go_library( "directory.go", "filesystem.go", "memfs.go", + "named_pipe.go", "regular_file.go", "symlink.go", ], importpath = "gvisor.dev/gvisor/pkg/sentry/fsimpl/memfs", deps = [ "//pkg/abi/linux", + "//pkg/amutex", + "//pkg/sentry/arch", "//pkg/sentry/context", "//pkg/sentry/kernel/auth", + "//pkg/sentry/kernel/pipe", "//pkg/sentry/usermem", "//pkg/sentry/vfs", "//pkg/syserror", @@ -54,3 +58,19 @@ go_test( "//pkg/syserror", ], ) + +go_test( + name = "memfs_test", + size = "small", + srcs = ["pipe_test.go"], + embed = [":memfs"], + deps = [ + "//pkg/abi/linux", + "//pkg/sentry/context", + "//pkg/sentry/context/contexttest", + "//pkg/sentry/kernel/auth", + "//pkg/sentry/usermem", + "//pkg/sentry/vfs", + "//pkg/syserror", + ], +) diff --git a/pkg/sentry/fsimpl/memfs/filesystem.go b/pkg/sentry/fsimpl/memfs/filesystem.go index f79e2d9c8..f006c40cd 100644 --- a/pkg/sentry/fsimpl/memfs/filesystem.go +++ b/pkg/sentry/fsimpl/memfs/filesystem.go @@ -233,7 +233,7 @@ func (fs *filesystem) MknodAt(ctx context.Context, rp *vfs.ResolvingPath, opts v if err != nil { return err } - _, err = checkCreateLocked(rp, parentVFSD, parentInode) + pc, err := checkCreateLocked(rp, parentVFSD, parentInode) if err != nil { return err } @@ -241,8 +241,40 @@ func (fs *filesystem) MknodAt(ctx context.Context, rp *vfs.ResolvingPath, opts v return err } defer rp.Mount().EndWrite() - // TODO: actually implement mknod - return syserror.EPERM + + switch opts.Mode.FileType() { + case 0: + // "Zero file type is equivalent to type S_IFREG." - mknod(2) + fallthrough + case linux.ModeRegular: + // TODO(b/138862511): Implement. + return syserror.EINVAL + + case linux.ModeNamedPipe: + child := fs.newDentry(fs.newNamedPipe(rp.Credentials(), opts.Mode)) + parentVFSD.InsertChild(&child.vfsd, pc) + parentInode.impl.(*directory).childList.PushBack(child) + return nil + + case linux.ModeSocket: + // TODO(b/138862511): Implement. + return syserror.EINVAL + + case linux.ModeCharacterDevice: + fallthrough + case linux.ModeBlockDevice: + // TODO(b/72101894): We don't support creating block or character + // devices at the moment. + // + // When we start supporting block and character devices, we'll + // need to check for CAP_MKNOD here. + return syserror.EPERM + + default: + // "EINVAL - mode requested creation of something other than a + // regular file, device special file, FIFO or socket." - mknod(2) + return syserror.EINVAL + } } // OpenAt implements vfs.FilesystemImpl.OpenAt. @@ -250,8 +282,9 @@ func (fs *filesystem) OpenAt(ctx context.Context, rp *vfs.ResolvingPath, opts vf // Filter out flags that are not supported by memfs. O_DIRECTORY and // O_NOFOLLOW have no effect here (they're handled by VFS by setting // appropriate bits in rp), but are returned by - // FileDescriptionImpl.StatusFlags(). - opts.Flags &= linux.O_ACCMODE | linux.O_CREAT | linux.O_EXCL | linux.O_TRUNC | linux.O_DIRECTORY | linux.O_NOFOLLOW + // FileDescriptionImpl.StatusFlags(). O_NONBLOCK is supported only by + // pipes. + opts.Flags &= linux.O_ACCMODE | linux.O_CREAT | linux.O_EXCL | linux.O_TRUNC | linux.O_DIRECTORY | linux.O_NOFOLLOW | linux.O_NONBLOCK if opts.Flags&linux.O_CREAT == 0 { fs.mu.RLock() @@ -260,7 +293,7 @@ func (fs *filesystem) OpenAt(ctx context.Context, rp *vfs.ResolvingPath, opts vf if err != nil { return nil, err } - return inode.open(rp, vfsd, opts.Flags, false) + return inode.open(ctx, rp, vfsd, opts.Flags, false) } mustCreate := opts.Flags&linux.O_EXCL != 0 @@ -275,7 +308,7 @@ func (fs *filesystem) OpenAt(ctx context.Context, rp *vfs.ResolvingPath, opts vf if mustCreate { return nil, syserror.EEXIST } - return inode.open(rp, vfsd, opts.Flags, false) + return inode.open(ctx, rp, vfsd, opts.Flags, false) } afterTrailingSymlink: // Walk to the parent directory of the last path component. @@ -320,7 +353,7 @@ afterTrailingSymlink: child := fs.newDentry(childInode) vfsd.InsertChild(&child.vfsd, pc) inode.impl.(*directory).childList.PushBack(child) - return childInode.open(rp, &child.vfsd, opts.Flags, true) + return childInode.open(ctx, rp, &child.vfsd, opts.Flags, true) } // Open existing file or follow symlink. if mustCreate { @@ -336,10 +369,10 @@ afterTrailingSymlink: // symlink target. goto afterTrailingSymlink } - return childInode.open(rp, childVFSD, opts.Flags, false) + return childInode.open(ctx, rp, childVFSD, opts.Flags, false) } -func (i *inode) open(rp *vfs.ResolvingPath, vfsd *vfs.Dentry, flags uint32, afterCreate bool) (*vfs.FileDescription, error) { +func (i *inode) open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, flags uint32, afterCreate bool) (*vfs.FileDescription, error) { ats := vfs.AccessTypesForOpenFlags(flags) if !afterCreate { if err := i.checkPermissions(rp.Credentials(), ats, i.isDir()); err != nil { @@ -378,6 +411,8 @@ func (i *inode) open(rp *vfs.ResolvingPath, vfsd *vfs.Dentry, flags uint32, afte case *symlink: // Can't open symlinks without O_PATH (which is unimplemented). return nil, syserror.ELOOP + case *namedPipe: + return newNamedPipeFD(ctx, impl, rp, vfsd, flags) default: panic(fmt.Sprintf("unknown inode type: %T", i.impl)) } diff --git a/pkg/sentry/fsimpl/memfs/memfs.go b/pkg/sentry/fsimpl/memfs/memfs.go index b78471c0f..64c851c1a 100644 --- a/pkg/sentry/fsimpl/memfs/memfs.go +++ b/pkg/sentry/fsimpl/memfs/memfs.go @@ -227,6 +227,8 @@ func (i *inode) statTo(stat *linux.Statx) { stat.Mask |= linux.STATX_SIZE | linux.STATX_BLOCKS stat.Size = uint64(len(impl.target)) stat.Blocks = allocatedBlocksForSize(stat.Size) + case *namedPipe: + stat.Mode |= linux.S_IFIFO default: panic(fmt.Sprintf("unknown inode type: %T", i.impl)) } diff --git a/pkg/sentry/fsimpl/memfs/named_pipe.go b/pkg/sentry/fsimpl/memfs/named_pipe.go new file mode 100644 index 000000000..732ed7c58 --- /dev/null +++ b/pkg/sentry/fsimpl/memfs/named_pipe.go @@ -0,0 +1,59 @@ +// 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 memfs + +import ( + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/sentry/context" + "gvisor.dev/gvisor/pkg/sentry/kernel/auth" + "gvisor.dev/gvisor/pkg/sentry/kernel/pipe" + "gvisor.dev/gvisor/pkg/sentry/usermem" + "gvisor.dev/gvisor/pkg/sentry/vfs" +) + +type namedPipe struct { + inode inode + + pipe *pipe.VFSPipe +} + +// Preconditions: +// * fs.mu must be locked. +// * rp.Mount().CheckBeginWrite() has been called successfully. +func (fs *filesystem) newNamedPipe(creds *auth.Credentials, mode linux.FileMode) *inode { + file := &namedPipe{pipe: pipe.NewVFSPipe(pipe.DefaultPipeSize, usermem.PageSize)} + file.inode.init(file, fs, creds, mode) + file.inode.nlink = 1 // Only the parent has a link. + return &file.inode +} + +// namedPipeFD implements vfs.FileDescriptionImpl. Methods are implemented +// entirely via struct embedding. +type namedPipeFD struct { + fileDescription + + *pipe.VFSPipeFD +} + +func newNamedPipeFD(ctx context.Context, np *namedPipe, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, flags uint32) (*vfs.FileDescription, error) { + var err error + var fd namedPipeFD + fd.VFSPipeFD, err = np.pipe.NewVFSPipeFD(ctx, rp, vfsd, &fd.vfsfd, flags) + if err != nil { + return nil, err + } + fd.vfsfd.Init(&fd, rp.Mount(), vfsd) + return &fd.vfsfd, nil +} diff --git a/pkg/sentry/fsimpl/memfs/pipe_test.go b/pkg/sentry/fsimpl/memfs/pipe_test.go new file mode 100644 index 000000000..0674b81a3 --- /dev/null +++ b/pkg/sentry/fsimpl/memfs/pipe_test.go @@ -0,0 +1,233 @@ +// 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 memfs + +import ( + "bytes" + "testing" + + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/sentry/context" + "gvisor.dev/gvisor/pkg/sentry/context/contexttest" + "gvisor.dev/gvisor/pkg/sentry/kernel/auth" + "gvisor.dev/gvisor/pkg/sentry/usermem" + "gvisor.dev/gvisor/pkg/sentry/vfs" + "gvisor.dev/gvisor/pkg/syserror" +) + +const fileName = "mypipe" + +func TestSeparateFDs(t *testing.T) { + ctx, creds, vfsObj, root := setup(t) + defer root.DecRef() + + // Open the read side. This is done in a concurrently because opening + // One end the pipe blocks until the other end is opened. + pop := vfs.PathOperation{ + Root: root, + Start: root, + Pathname: fileName, + FollowFinalSymlink: true, + } + rfdchan := make(chan *vfs.FileDescription) + go func() { + openOpts := vfs.OpenOptions{Flags: linux.O_RDONLY} + rfd, _ := vfsObj.OpenAt(ctx, creds, &pop, &openOpts) + rfdchan <- rfd + }() + + // Open the write side. + openOpts := vfs.OpenOptions{Flags: linux.O_WRONLY} + wfd, err := vfsObj.OpenAt(ctx, creds, &pop, &openOpts) + if err != nil { + t.Fatalf("failed to open pipe for writing %q: %v", fileName, err) + } + defer wfd.DecRef() + + rfd, ok := <-rfdchan + if !ok { + t.Fatalf("failed to open pipe for reading %q", fileName) + } + defer rfd.DecRef() + + const msg = "vamos azul" + checkEmpty(ctx, t, rfd) + checkWrite(ctx, t, wfd, msg) + checkRead(ctx, t, rfd, msg) +} + +func TestNonblockingRead(t *testing.T) { + ctx, creds, vfsObj, root := setup(t) + defer root.DecRef() + + // Open the read side as nonblocking. + pop := vfs.PathOperation{ + Root: root, + Start: root, + Pathname: fileName, + FollowFinalSymlink: true, + } + openOpts := vfs.OpenOptions{Flags: linux.O_RDONLY | linux.O_NONBLOCK} + rfd, err := vfsObj.OpenAt(ctx, creds, &pop, &openOpts) + if err != nil { + t.Fatalf("failed to open pipe for reading %q: %v", fileName, err) + } + defer rfd.DecRef() + + // Open the write side. + openOpts = vfs.OpenOptions{Flags: linux.O_WRONLY} + wfd, err := vfsObj.OpenAt(ctx, creds, &pop, &openOpts) + if err != nil { + t.Fatalf("failed to open pipe for writing %q: %v", fileName, err) + } + defer wfd.DecRef() + + const msg = "geh blau" + checkEmpty(ctx, t, rfd) + checkWrite(ctx, t, wfd, msg) + checkRead(ctx, t, rfd, msg) +} + +func TestNonblockingWriteError(t *testing.T) { + ctx, creds, vfsObj, root := setup(t) + defer root.DecRef() + + // Open the write side as nonblocking, which should return ENXIO. + pop := vfs.PathOperation{ + Root: root, + Start: root, + Pathname: fileName, + FollowFinalSymlink: true, + } + openOpts := vfs.OpenOptions{Flags: linux.O_WRONLY | linux.O_NONBLOCK} + _, err := vfsObj.OpenAt(ctx, creds, &pop, &openOpts) + if err != syserror.ENXIO { + t.Fatalf("expected ENXIO, but got error: %v", err) + } +} + +func TestSingleFD(t *testing.T) { + ctx, creds, vfsObj, root := setup(t) + defer root.DecRef() + + // Open the pipe as readable and writable. + pop := vfs.PathOperation{ + Root: root, + Start: root, + Pathname: fileName, + FollowFinalSymlink: true, + } + openOpts := vfs.OpenOptions{Flags: linux.O_RDWR} + fd, err := vfsObj.OpenAt(ctx, creds, &pop, &openOpts) + if err != nil { + t.Fatalf("failed to open pipe for writing %q: %v", fileName, err) + } + defer fd.DecRef() + + const msg = "forza blu" + checkEmpty(ctx, t, fd) + checkWrite(ctx, t, fd, msg) + checkRead(ctx, t, fd, msg) +} + +// setup creates a VFS with a pipe in the root directory at path fileName. The +// returned VirtualDentry must be DecRef()'d be the caller. It calls t.Fatal +// upon failure. +func setup(t *testing.T) (context.Context, *auth.Credentials, *vfs.VirtualFilesystem, vfs.VirtualDentry) { + ctx := contexttest.Context(t) + creds := auth.CredentialsFromContext(ctx) + + // Create VFS. + vfsObj := vfs.New() + vfsObj.MustRegisterFilesystemType("memfs", FilesystemType{}) + mntns, err := vfsObj.NewMountNamespace(ctx, creds, "", "memfs", &vfs.NewFilesystemOptions{}) + if err != nil { + t.Fatalf("failed to create tmpfs root mount: %v", err) + } + + // Create the pipe. + root := mntns.Root() + pop := vfs.PathOperation{ + Root: root, + Start: root, + Pathname: fileName, + FollowFinalSymlink: true, + } + mknodOpts := vfs.MknodOptions{Mode: linux.ModeNamedPipe | 0644} + if err := vfsObj.MknodAt(ctx, creds, &pop, &mknodOpts); err != nil { + t.Fatalf("failed to create file %q: %v", fileName, err) + } + + // Sanity check: the file pipe exists and has the correct mode. + stat, err := vfsObj.StatAt(ctx, creds, &vfs.PathOperation{ + Root: root, + Start: root, + Pathname: fileName, + FollowFinalSymlink: true, + }, &vfs.StatOptions{}) + if err != nil { + t.Fatalf("stat(%q) failed: %v", fileName, err) + } + if stat.Mode&^linux.S_IFMT != 0644 { + t.Errorf("got wrong permissions (%0o)", stat.Mode) + } + if stat.Mode&linux.S_IFMT != linux.ModeNamedPipe { + t.Errorf("got wrong file type (%0o)", stat.Mode) + } + + return ctx, creds, vfsObj, root +} + +// checkEmpty calls t.Fatal if the pipe in fd is not empty. +func checkEmpty(ctx context.Context, t *testing.T, fd *vfs.FileDescription) { + readData := make([]byte, 1) + dst := usermem.BytesIOSequence(readData) + bytesRead, err := fd.Impl().Read(ctx, dst, vfs.ReadOptions{}) + if err != syserror.ErrWouldBlock { + t.Fatalf("expected ErrWouldBlock reading from empty pipe %q, but got: %v", fileName, err) + } + if bytesRead != 0 { + t.Fatalf("expected to read 0 bytes, but got %d", bytesRead) + } +} + +// checkWrite calls t.Fatal if it fails to write all of msg to fd. +func checkWrite(ctx context.Context, t *testing.T, fd *vfs.FileDescription, msg string) { + writeData := []byte(msg) + src := usermem.BytesIOSequence(writeData) + bytesWritten, err := fd.Impl().Write(ctx, src, vfs.WriteOptions{}) + if err != nil { + t.Fatalf("error writing to pipe %q: %v", fileName, err) + } + if bytesWritten != int64(len(writeData)) { + t.Fatalf("expected to write %d bytes, but wrote %d", len(writeData), bytesWritten) + } +} + +// checkRead calls t.Fatal if it fails to read msg from fd. +func checkRead(ctx context.Context, t *testing.T, fd *vfs.FileDescription, msg string) { + readData := make([]byte, len(msg)) + dst := usermem.BytesIOSequence(readData) + bytesRead, err := fd.Impl().Read(ctx, dst, vfs.ReadOptions{}) + if err != nil { + t.Fatalf("error reading from pipe %q: %v", fileName, err) + } + if bytesRead != int64(len(msg)) { + t.Fatalf("expected to read %d bytes, but got %d", len(msg), bytesRead) + } + if !bytes.Equal(readData, []byte(msg)) { + t.Fatalf("expected to read %q from pipe, but got %q", msg, string(readData)) + } +} diff --git a/pkg/sentry/kernel/pipe/vfs.go b/pkg/sentry/kernel/pipe/vfs.go index 02320b830..6416e0dd8 100644 --- a/pkg/sentry/kernel/pipe/vfs.go +++ b/pkg/sentry/kernel/pipe/vfs.go @@ -182,7 +182,7 @@ func (fd *VFSPipeFD) Release() { } // OnClose implements vfs.FileDescriptionImpl.OnClose. -func (fd *VFSPipeFD) OnClose() error { +func (fd *VFSPipeFD) OnClose(_ context.Context) error { return nil } diff --git a/pkg/sentry/platform/ptrace/subprocess.go b/pkg/sentry/platform/ptrace/subprocess.go index 9f0ecfbe4..b699b057d 100644 --- a/pkg/sentry/platform/ptrace/subprocess.go +++ b/pkg/sentry/platform/ptrace/subprocess.go @@ -327,6 +327,19 @@ func (t *thread) dumpAndPanic(message string) { panic(message) } +func (t *thread) unexpectedStubExit() { + msg, err := t.getEventMessage() + status := syscall.WaitStatus(msg) + if status.Signaled() && status.Signal() == syscall.SIGKILL { + // SIGKILL can be only sent by an user or OOM-killer. In both + // these cases, we don't need to panic. There is no reasons to + // think that something wrong in gVisor. + log.Warningf("The ptrace stub process %v has been killed by SIGKILL.", t.tgid) + syscall.Kill(os.Getpid(), syscall.SIGKILL) + } + t.dumpAndPanic(fmt.Sprintf("wait failed: the process %d:%d exited: %x (err %v)", t.tgid, t.tid, msg, err)) +} + // wait waits for a stop event. // // Precondition: outcome is a valid waitOutcome. @@ -355,8 +368,7 @@ func (t *thread) wait(outcome waitOutcome) syscall.Signal { } if stopSig == syscall.SIGTRAP { if status.TrapCause() == syscall.PTRACE_EVENT_EXIT { - msg, err := t.getEventMessage() - t.dumpAndPanic(fmt.Sprintf("wait failed: the process %d:%d exited: %x (err %v)", t.tgid, t.tid, msg, err)) + t.unexpectedStubExit() } // Re-encode the trap cause the way it's expected. return stopSig | syscall.Signal(status.TrapCause()<<8) diff --git a/pkg/sentry/platform/ptrace/subprocess_linux.go b/pkg/sentry/platform/ptrace/subprocess_linux.go index c075b5f91..3782d4332 100644 --- a/pkg/sentry/platform/ptrace/subprocess_linux.go +++ b/pkg/sentry/platform/ptrace/subprocess_linux.go @@ -129,6 +129,9 @@ func createStub() (*thread, error) { // transitively) will be killed as well. It's simply not possible to // safely handle a single stub getting killed: the exact state of // execution is unknown and not recoverable. + // + // In addition, we set the PTRACE_O_TRACEEXIT option to log more + // information about a stub process when it receives a fatal signal. return attachedThread(uintptr(syscall.SIGKILL)|syscall.CLONE_FILES, defaultAction) } diff --git a/pkg/sentry/socket/netstack/netstack.go b/pkg/sentry/socket/netstack/netstack.go index 0ae573b45..debf9bce0 100644 --- a/pkg/sentry/socket/netstack/netstack.go +++ b/pkg/sentry/socket/netstack/netstack.go @@ -53,6 +53,7 @@ import ( "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/tcpip/buffer" + "gvisor.dev/gvisor/pkg/tcpip/header" "gvisor.dev/gvisor/pkg/tcpip/stack" "gvisor.dev/gvisor/pkg/tcpip/transport/tcp" "gvisor.dev/gvisor/pkg/tcpip/transport/udp" @@ -296,6 +297,7 @@ func New(t *kernel.Task, family int, skType linux.SockType, protocol int, queue var sockAddrInetSize = int(binary.Size(linux.SockAddrInet{})) var sockAddrInet6Size = int(binary.Size(linux.SockAddrInet6{})) +var sockAddrLinkSize = int(binary.Size(linux.SockAddrLink{})) // bytesToIPAddress converts an IPv4 or IPv6 address from the user to the // netstack representation taking any addresses into account. @@ -307,12 +309,12 @@ func bytesToIPAddress(addr []byte) tcpip.Address { } // AddressAndFamily reads an sockaddr struct from the given address and -// converts it to the FullAddress format. It supports AF_UNIX, AF_INET and -// AF_INET6 addresses. +// converts it to the FullAddress format. It supports AF_UNIX, AF_INET, +// AF_INET6, and AF_PACKET addresses. // // strict indicates whether addresses with the AF_UNSPEC family are accepted of not. // -// AddressAndFamily returns an address, its family. +// AddressAndFamily returns an address and its family. func AddressAndFamily(sfamily int, addr []byte, strict bool) (tcpip.FullAddress, uint16, *syserr.Error) { // Make sure we have at least 2 bytes for the address family. if len(addr) < 2 { @@ -371,6 +373,22 @@ func AddressAndFamily(sfamily int, addr []byte, strict bool) (tcpip.FullAddress, } return out, family, nil + case linux.AF_PACKET: + var a linux.SockAddrLink + if len(addr) < sockAddrLinkSize { + return tcpip.FullAddress{}, family, syserr.ErrInvalidArgument + } + binary.Unmarshal(addr[:sockAddrLinkSize], usermem.ByteOrder, &a) + if a.Family != linux.AF_PACKET || a.HardwareAddrLen != header.EthernetAddressSize { + return tcpip.FullAddress{}, family, syserr.ErrInvalidArgument + } + + // TODO(b/129292371): Return protocol too. + return tcpip.FullAddress{ + NIC: tcpip.NICID(a.InterfaceIndex), + Addr: tcpip.Address(a.HardwareAddr[:header.EthernetAddressSize]), + }, family, nil + case linux.AF_UNSPEC: return tcpip.FullAddress{}, family, nil @@ -1951,12 +1969,14 @@ func ConvertAddress(family int, addr tcpip.FullAddress) (linux.SockAddr, uint32) return &out, uint32(2 + l) } return &out, uint32(3 + l) + case linux.AF_INET: var out linux.SockAddrInet copy(out.Addr[:], addr.Addr) out.Family = linux.AF_INET out.Port = htons(addr.Port) - return &out, uint32(binary.Size(out)) + return &out, uint32(sockAddrInetSize) + case linux.AF_INET6: var out linux.SockAddrInet6 if len(addr.Addr) == 4 { @@ -1972,7 +1992,17 @@ func ConvertAddress(family int, addr tcpip.FullAddress) (linux.SockAddr, uint32) if isLinkLocal(addr.Addr) { out.Scope_id = uint32(addr.NIC) } - return &out, uint32(binary.Size(out)) + return &out, uint32(sockAddrInet6Size) + + case linux.AF_PACKET: + // TODO(b/129292371): Return protocol too. + var out linux.SockAddrLink + out.Family = linux.AF_PACKET + out.InterfaceIndex = int32(addr.NIC) + out.HardwareAddrLen = header.EthernetAddressSize + copy(out.HardwareAddr[:], addr.Addr) + return &out, uint32(sockAddrLinkSize) + default: return nil, 0 } diff --git a/pkg/sentry/socket/netstack/provider.go b/pkg/sentry/socket/netstack/provider.go index 357a664cc..2d2c1ba2a 100644 --- a/pkg/sentry/socket/netstack/provider.go +++ b/pkg/sentry/socket/netstack/provider.go @@ -62,6 +62,10 @@ func getTransportProtocol(ctx context.Context, stype linux.SockType, protocol in } case linux.SOCK_RAW: + // TODO(b/142504697): "In order to create a raw socket, a + // process must have the CAP_NET_RAW capability in the user + // namespace that governs its network namespace." - raw(7) + // Raw sockets require CAP_NET_RAW. creds := auth.CredentialsFromContext(ctx) if !creds.HasCapability(linux.CAP_NET_RAW) { @@ -85,7 +89,8 @@ func getTransportProtocol(ctx context.Context, stype linux.SockType, protocol in return 0, true, syserr.ErrProtocolNotSupported } -// Socket creates a new socket object for the AF_INET or AF_INET6 family. +// Socket creates a new socket object for the AF_INET, AF_INET6, or AF_PACKET +// family. func (p *provider) Socket(t *kernel.Task, stype linux.SockType, protocol int) (*fs.File, *syserr.Error) { // Fail right away if we don't have a stack. stack := t.NetworkContext() @@ -99,6 +104,12 @@ func (p *provider) Socket(t *kernel.Task, stype linux.SockType, protocol int) (* return nil, nil } + // Packet sockets are handled separately, since they are neither INET + // nor INET6 specific. + if p.family == linux.AF_PACKET { + return packetSocket(t, eps, stype, protocol) + } + // Figure out the transport protocol. transProto, associated, err := getTransportProtocol(t, stype, protocol) if err != nil { @@ -121,12 +132,47 @@ func (p *provider) Socket(t *kernel.Task, stype linux.SockType, protocol int) (* return New(t, p.family, stype, int(transProto), wq, ep) } +func packetSocket(t *kernel.Task, epStack *Stack, stype linux.SockType, protocol int) (*fs.File, *syserr.Error) { + // TODO(b/142504697): "In order to create a packet socket, a process + // must have the CAP_NET_RAW capability in the user namespace that + // governs its network namespace." - packet(7) + + // Packet sockets require CAP_NET_RAW. + creds := auth.CredentialsFromContext(t) + if !creds.HasCapability(linux.CAP_NET_RAW) { + return nil, syserr.ErrNotPermitted + } + + // "cooked" packets don't contain link layer information. + var cooked bool + switch stype { + case linux.SOCK_DGRAM: + cooked = true + case linux.SOCK_RAW: + cooked = false + default: + return nil, syserr.ErrProtocolNotSupported + } + + // protocol is passed in network byte order, but netstack wants it in + // host order. + netProto := tcpip.NetworkProtocolNumber(ntohs(uint16(protocol))) + + wq := &waiter.Queue{} + ep, err := epStack.Stack.NewPacketEndpoint(cooked, netProto, wq) + if err != nil { + return nil, syserr.TranslateNetstackError(err) + } + + return New(t, linux.AF_PACKET, stype, protocol, wq, ep) +} + // Pair just returns nil sockets (not supported). func (*provider) Pair(*kernel.Task, linux.SockType, int) (*fs.File, *fs.File, *syserr.Error) { return nil, nil, nil } -// init registers socket providers for AF_INET and AF_INET6. +// init registers socket providers for AF_INET, AF_INET6, and AF_PACKET. func init() { // Providers backed by netstack. p := []provider{ @@ -138,6 +184,9 @@ func init() { family: linux.AF_INET6, netProto: ipv6.ProtocolNumber, }, + { + family: linux.AF_PACKET, + }, } for i := range p { diff --git a/pkg/sentry/syscalls/linux/linux64.go b/pkg/sentry/syscalls/linux/linux64.go index b317cb99d..68589a377 100644 --- a/pkg/sentry/syscalls/linux/linux64.go +++ b/pkg/sentry/syscalls/linux/linux64.go @@ -16,7 +16,12 @@ package linux const ( - _LINUX_SYSNAME = "Linux" - _LINUX_RELEASE = "4.4.0" - _LINUX_VERSION = "#1 SMP Sun Jan 10 15:06:54 PST 2016" + // LinuxSysname is the OS name advertised by gVisor. + LinuxSysname = "Linux" + + // LinuxRelease is the Linux release version number advertised by gVisor. + LinuxRelease = "4.4.0" + + // LinuxVersion is the version info advertised by gVisor. + LinuxVersion = "#1 SMP Sun Jan 10 15:06:54 PST 2016" ) diff --git a/pkg/sentry/syscalls/linux/linux64_amd64.go b/pkg/sentry/syscalls/linux/linux64_amd64.go index e215ac049..aedb6d774 100644 --- a/pkg/sentry/syscalls/linux/linux64_amd64.go +++ b/pkg/sentry/syscalls/linux/linux64_amd64.go @@ -34,9 +34,9 @@ var AMD64 = &kernel.SyscallTable{ // guides the interface provided by this syscall table. The build // version is that for a clean build with default kernel config, at 5 // minutes after v4.4 was tagged. - Sysname: _LINUX_SYSNAME, - Release: _LINUX_RELEASE, - Version: _LINUX_VERSION, + Sysname: LinuxSysname, + Release: LinuxRelease, + Version: LinuxVersion, }, AuditNumber: linux.AUDIT_ARCH_X86_64, Table: map[uintptr]kernel.Syscall{ @@ -362,7 +362,7 @@ var AMD64 = &kernel.SyscallTable{ 319: syscalls.Supported("memfd_create", MemfdCreate), 320: syscalls.CapError("kexec_file_load", linux.CAP_SYS_BOOT, "", nil), 321: syscalls.CapError("bpf", linux.CAP_SYS_ADMIN, "", nil), - 322: syscalls.ErrorWithEvent("execveat", syserror.ENOSYS, "", []string{"gvisor.dev/issue/265"}), // TODO(b/118901836) + 322: syscalls.PartiallySupported("execveat", Execveat, "No support for AT_EMPTY_PATH, AT_SYMLINK_FOLLOW.", nil), 323: syscalls.ErrorWithEvent("userfaultfd", syserror.ENOSYS, "", []string{"gvisor.dev/issue/266"}), // TODO(b/118906345) 324: syscalls.ErrorWithEvent("membarrier", syserror.ENOSYS, "", []string{"gvisor.dev/issue/267"}), // TODO(b/118904897) 325: syscalls.PartiallySupported("mlock2", Mlock2, "Stub implementation. The sandbox lacks appropriate permissions.", nil), diff --git a/pkg/sentry/syscalls/linux/linux64_arm64.go b/pkg/sentry/syscalls/linux/linux64_arm64.go index f82dfac31..4cf7f836a 100644 --- a/pkg/sentry/syscalls/linux/linux64_arm64.go +++ b/pkg/sentry/syscalls/linux/linux64_arm64.go @@ -30,9 +30,9 @@ var ARM64 = &kernel.SyscallTable{ OS: abi.Linux, Arch: arch.ARM64, Version: kernel.Version{ - Sysname: _LINUX_SYSNAME, - Release: _LINUX_RELEASE, - Version: _LINUX_VERSION, + Sysname: LinuxSysname, + Release: LinuxRelease, + Version: LinuxVersion, }, AuditNumber: linux.AUDIT_ARCH_AARCH64, Table: map[uintptr]kernel.Syscall{ diff --git a/pkg/sentry/syscalls/linux/sys_thread.go b/pkg/sentry/syscalls/linux/sys_thread.go index 8ab7ffa25..6e425f1ec 100644 --- a/pkg/sentry/syscalls/linux/sys_thread.go +++ b/pkg/sentry/syscalls/linux/sys_thread.go @@ -15,10 +15,12 @@ package linux import ( + "path" "syscall" "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/sentry/arch" + "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/kernel/sched" "gvisor.dev/gvisor/pkg/sentry/usermem" @@ -67,8 +69,22 @@ func Execve(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal argvAddr := args[1].Pointer() envvAddr := args[2].Pointer() - // Extract our arguments. - filename, err := t.CopyInString(filenameAddr, linux.PATH_MAX) + return execveat(t, linux.AT_FDCWD, filenameAddr, argvAddr, envvAddr, 0) +} + +// Execveat implements linux syscall execveat(2). +func Execveat(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { + dirFD := args[0].Int() + pathnameAddr := args[1].Pointer() + argvAddr := args[2].Pointer() + envvAddr := args[3].Pointer() + flags := args[4].Int() + + return execveat(t, dirFD, pathnameAddr, argvAddr, envvAddr, flags) +} + +func execveat(t *kernel.Task, dirFD int32, pathnameAddr, argvAddr, envvAddr usermem.Addr, flags int32) (uintptr, *kernel.SyscallControl, error) { + pathname, err := t.CopyInString(pathnameAddr, linux.PATH_MAX) if err != nil { return 0, nil, err } @@ -89,14 +105,38 @@ func Execve(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal } } + if flags != 0 { + // TODO(b/128449944): Handle AT_EMPTY_PATH and AT_SYMLINK_NOFOLLOW. + t.Kernel().EmitUnimplementedEvent(t) + return 0, nil, syserror.ENOSYS + } + root := t.FSContext().RootDirectory() defer root.DecRef() - wd := t.FSContext().WorkingDirectory() + + var wd *fs.Dirent + if dirFD == linux.AT_FDCWD || path.IsAbs(pathname) { + // If pathname is absolute, LoadTaskImage() will ignore the wd. + wd = t.FSContext().WorkingDirectory() + } else { + // Need to extract the given FD. + f := t.GetFile(dirFD) + if f == nil { + return 0, nil, syserror.EBADF + } + defer f.DecRef() + + wd = f.Dirent + wd.IncRef() + if !fs.IsDir(wd.Inode.StableAttr) { + return 0, nil, syserror.ENOTDIR + } + } defer wd.DecRef() // Load the new TaskContext. maxTraversals := uint(linux.MaxSymlinkTraversals) - tc, se := t.Kernel().LoadTaskImage(t, t.MountNamespace(), root, wd, &maxTraversals, filename, nil, argv, envv, t.Arch().FeatureSet()) + tc, se := t.Kernel().LoadTaskImage(t, t.MountNamespace(), root, wd, &maxTraversals, pathname, nil, argv, envv, t.Arch().FeatureSet()) if se != nil { return 0, nil, se.ToError() } diff --git a/pkg/sentry/syscalls/linux/sys_write.go b/pkg/sentry/syscalls/linux/sys_write.go index 27cd2c336..ad4b67806 100644 --- a/pkg/sentry/syscalls/linux/sys_write.go +++ b/pkg/sentry/syscalls/linux/sys_write.go @@ -191,7 +191,6 @@ func Pwritev(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysca } // Pwritev2 implements linux syscall pwritev2(2). -// TODO(b/120161091): Implement O_SYNC and D_SYNC functionality. func Pwritev2(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { // While the syscall is // pwritev2(int fd, struct iovec* iov, int iov_cnt, off_t offset, int flags) diff --git a/pkg/sentry/vfs/syscalls.go b/pkg/sentry/vfs/syscalls.go index 23f2b9e08..abde0feaa 100644 --- a/pkg/sentry/vfs/syscalls.go +++ b/pkg/sentry/vfs/syscalls.go @@ -96,6 +96,26 @@ func (vfs *VirtualFilesystem) MkdirAt(ctx context.Context, creds *auth.Credentia } } +// MknodAt creates a file of the given mode at the given path. It returns an +// error from the syserror package. +func (vfs *VirtualFilesystem) MknodAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, opts *MknodOptions) error { + rp, err := vfs.getResolvingPath(creds, pop) + if err != nil { + return nil + } + for { + if err = rp.mount.fs.impl.MknodAt(ctx, rp, *opts); err == nil { + vfs.putResolvingPath(rp) + return nil + } + // Handle mount traversals. + if !rp.handleError(err) { + vfs.putResolvingPath(rp) + return err + } + } +} + // OpenAt returns a FileDescription providing access to the file at the given // path. A reference is taken on the returned FileDescription. func (vfs *VirtualFilesystem) OpenAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, opts *OpenOptions) (*FileDescription, error) { @@ -198,8 +218,6 @@ func (fd *FileDescription) SetStatusFlags(ctx context.Context, flags uint32) err // // - VFS.LinkAt() // -// - VFS.MknodAt() -// // - VFS.ReadlinkAt() // // - VFS.RenameAt() |