diff options
| -rw-r--r-- | pkg/sentry/fsimpl/sockfs/BUILD | 16 | ||||
| -rw-r--r-- | pkg/sentry/fsimpl/sockfs/sockfs.go | 73 | ||||
| -rw-r--r-- | pkg/sentry/kernel/BUILD | 1 | ||||
| -rw-r--r-- | pkg/sentry/kernel/kernel.go | 24 | ||||
| -rw-r--r-- | test/syscalls/linux/socket_unix.cc | 2 |
5 files changed, 116 insertions, 0 deletions
diff --git a/pkg/sentry/fsimpl/sockfs/BUILD b/pkg/sentry/fsimpl/sockfs/BUILD new file mode 100644 index 000000000..790d50e65 --- /dev/null +++ b/pkg/sentry/fsimpl/sockfs/BUILD @@ -0,0 +1,16 @@ +load("//tools:defs.bzl", "go_library") + +licenses(["notice"]) + +go_library( + name = "sockfs", + srcs = ["sockfs.go"], + visibility = ["//pkg/sentry:internal"], + deps = [ + "//pkg/context", + "//pkg/sentry/fsimpl/kernfs", + "//pkg/sentry/kernel/auth", + "//pkg/sentry/vfs", + "//pkg/syserror", + ], +) diff --git a/pkg/sentry/fsimpl/sockfs/sockfs.go b/pkg/sentry/fsimpl/sockfs/sockfs.go new file mode 100644 index 000000000..c13511de2 --- /dev/null +++ b/pkg/sentry/fsimpl/sockfs/sockfs.go @@ -0,0 +1,73 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// Package sockfs provides a filesystem implementation for anonymous sockets. +package sockfs + +import ( + "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs" + "gvisor.dev/gvisor/pkg/sentry/kernel/auth" + "gvisor.dev/gvisor/pkg/sentry/vfs" + "gvisor.dev/gvisor/pkg/syserror" +) + +// NewFilesystem creates a new sockfs filesystem. +// +// Note that there should only ever be one instance of sockfs.Filesystem, +// backing a global socket mount. +func NewFilesystem(vfsObj *vfs.VirtualFilesystem) *vfs.Filesystem { + fs, _, err := filesystemType{}.GetFilesystem(nil, vfsObj, nil, "", vfs.GetFilesystemOptions{}) + if err != nil { + panic("failed to create sockfs filesystem") + } + return fs +} + +// filesystemType implements vfs.FilesystemType. +type filesystemType struct{} + +// GetFilesystem implements FilesystemType.GetFilesystem. +func (fsType filesystemType) GetFilesystem(_ context.Context, vfsObj *vfs.VirtualFilesystem, _ *auth.Credentials, _ string, _ vfs.GetFilesystemOptions) (*vfs.Filesystem, *vfs.Dentry, error) { + fs := &filesystem{} + fs.Init(vfsObj, fsType) + return fs.VFSFilesystem(), nil, nil +} + +// Name implements FilesystemType.Name. +// +// Note that registering sockfs is unnecessary, except for the fact that it +// will not show up under /proc/filesystems as a result. This is a very minor +// discrepancy from Linux. +func (filesystemType) Name() string { + return "sockfs" +} + +// filesystem implements vfs.FilesystemImpl. +type filesystem struct { + kernfs.Filesystem +} + +// inode implements kernfs.Inode. +type inode struct { + kernfs.InodeNotDirectory + kernfs.InodeNotSymlink + kernfs.InodeAttrs + kernfs.InodeNoopRefCount +} + +// Open implements kernfs.Inode.Open. +func (i *inode) Open(rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { + return nil, syserror.ENXIO +} diff --git a/pkg/sentry/kernel/BUILD b/pkg/sentry/kernel/BUILD index beba29a09..bb7e3cbc3 100644 --- a/pkg/sentry/kernel/BUILD +++ b/pkg/sentry/kernel/BUILD @@ -169,6 +169,7 @@ go_library( "//pkg/sentry/fs/lock", "//pkg/sentry/fs/timerfd", "//pkg/sentry/fsbridge", + "//pkg/sentry/fsimpl/sockfs", "//pkg/sentry/hostcpu", "//pkg/sentry/inet", "//pkg/sentry/kernel/auth", diff --git a/pkg/sentry/kernel/kernel.go b/pkg/sentry/kernel/kernel.go index 6feda8fa1..0a448b57c 100644 --- a/pkg/sentry/kernel/kernel.go +++ b/pkg/sentry/kernel/kernel.go @@ -50,6 +50,7 @@ import ( "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/fs/timerfd" "gvisor.dev/gvisor/pkg/sentry/fsbridge" + "gvisor.dev/gvisor/pkg/sentry/fsimpl/sockfs" "gvisor.dev/gvisor/pkg/sentry/hostcpu" "gvisor.dev/gvisor/pkg/sentry/inet" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" @@ -225,6 +226,11 @@ type Kernel struct { // by extMu. nextSocketEntry uint64 + // socketMount is a disconnected vfs.Mount, not included in k.vfs, + // representing a sockfs.filesystem. socketMount is used to back + // VirtualDentries representing anonymous sockets. + socketMount *vfs.Mount + // deviceRegistry is used to save/restore device.SimpleDevices. deviceRegistry struct{} `state:".(*device.Registry)"` @@ -348,6 +354,19 @@ func (k *Kernel) Init(args InitKernelArgs) error { k.monotonicClock = &timekeeperClock{tk: args.Timekeeper, c: sentrytime.Monotonic} k.futexes = futex.NewManager() k.netlinkPorts = port.New() + if VFS2Enabled { + if err := k.vfs.Init(); err != nil { + return fmt.Errorf("failed to initialize VFS: %v", err) + } + fs := sockfs.NewFilesystem(&k.vfs) + // NewDisconnectedMount will take an additional reference on fs. + defer fs.DecRef() + sm, err := k.vfs.NewDisconnectedMount(fs, nil, &vfs.MountOptions{}) + if err != nil { + return fmt.Errorf("failed to initialize socket mount: %v", err) + } + k.socketMount = sm + } return nil } @@ -1452,6 +1471,11 @@ func (k *Kernel) ListSockets() []*SocketEntry { return socks } +// SocketMount returns the global socket mount. +func (k *Kernel) SocketMount() *vfs.Mount { + return k.socketMount +} + // supervisorContext is a privileged context. type supervisorContext struct { context.NoopSleeper diff --git a/test/syscalls/linux/socket_unix.cc b/test/syscalls/linux/socket_unix.cc index 4cf1f76f1..8bf663e8b 100644 --- a/test/syscalls/linux/socket_unix.cc +++ b/test/syscalls/linux/socket_unix.cc @@ -257,6 +257,8 @@ TEST_P(UnixSocketPairTest, ShutdownWrite) { TEST_P(UnixSocketPairTest, SocketReopenFromProcfs) { // TODO(b/122310852): We should be returning ENXIO and NOT EIO. + // TODO(github.dev/issue/1624): This should be resolved in VFS2. Verify + // that this is the case and delete the SKIP_IF once we delete VFS1. SKIP_IF(IsRunningOnGvisor()); auto sockets = ASSERT_NO_ERRNO_AND_VALUE(NewSocketPair()); |