diff options
Diffstat (limited to 'pkg/sentry/fs/dev')
| -rw-r--r-- | pkg/sentry/fs/dev/dev.go | 146 | ||||
| -rwxr-xr-x | pkg/sentry/fs/dev/dev_state_autogen.go | 108 | ||||
| -rw-r--r-- | pkg/sentry/fs/dev/device.go | 20 | ||||
| -rw-r--r-- | pkg/sentry/fs/dev/fs.go | 99 | ||||
| -rw-r--r-- | pkg/sentry/fs/dev/full.go | 81 | ||||
| -rw-r--r-- | pkg/sentry/fs/dev/null.go | 130 | ||||
| -rw-r--r-- | pkg/sentry/fs/dev/random.go | 79 |
7 files changed, 663 insertions, 0 deletions
diff --git a/pkg/sentry/fs/dev/dev.go b/pkg/sentry/fs/dev/dev.go new file mode 100644 index 000000000..34ac01173 --- /dev/null +++ b/pkg/sentry/fs/dev/dev.go @@ -0,0 +1,146 @@ +// 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 dev provides a filesystem with simple devices. +package dev + +import ( + "math" + + "gvisor.googlesource.com/gvisor/pkg/sentry/context" + "gvisor.googlesource.com/gvisor/pkg/sentry/fs" + "gvisor.googlesource.com/gvisor/pkg/sentry/fs/ashmem" + "gvisor.googlesource.com/gvisor/pkg/sentry/fs/binder" + "gvisor.googlesource.com/gvisor/pkg/sentry/fs/ramfs" + "gvisor.googlesource.com/gvisor/pkg/sentry/fs/tmpfs" + "gvisor.googlesource.com/gvisor/pkg/sentry/usermem" +) + +// Memory device numbers are from Linux's drivers/char/mem.c +const ( + // Mem device major. + memDevMajor uint16 = 1 + + // Mem device minors. + nullDevMinor uint32 = 3 + zeroDevMinor uint32 = 5 + fullDevMinor uint32 = 7 + randomDevMinor uint32 = 8 + urandomDevMinor uint32 = 9 +) + +func newCharacterDevice(iops fs.InodeOperations, msrc *fs.MountSource) *fs.Inode { + return fs.NewInode(iops, msrc, fs.StableAttr{ + DeviceID: devDevice.DeviceID(), + InodeID: devDevice.NextIno(), + BlockSize: usermem.PageSize, + Type: fs.CharacterDevice, + }) +} + +func newMemDevice(iops fs.InodeOperations, msrc *fs.MountSource, minor uint32) *fs.Inode { + return fs.NewInode(iops, msrc, fs.StableAttr{ + DeviceID: devDevice.DeviceID(), + InodeID: devDevice.NextIno(), + BlockSize: usermem.PageSize, + Type: fs.CharacterDevice, + DeviceFileMajor: memDevMajor, + DeviceFileMinor: minor, + }) +} + +func newDirectory(ctx context.Context, msrc *fs.MountSource) *fs.Inode { + iops := ramfs.NewDir(ctx, nil, fs.RootOwner, fs.FilePermsFromMode(0555)) + return fs.NewInode(iops, msrc, fs.StableAttr{ + DeviceID: devDevice.DeviceID(), + InodeID: devDevice.NextIno(), + BlockSize: usermem.PageSize, + Type: fs.Directory, + }) +} + +func newSymlink(ctx context.Context, target string, msrc *fs.MountSource) *fs.Inode { + iops := ramfs.NewSymlink(ctx, fs.RootOwner, target) + return fs.NewInode(iops, msrc, fs.StableAttr{ + DeviceID: devDevice.DeviceID(), + InodeID: devDevice.NextIno(), + BlockSize: usermem.PageSize, + Type: fs.Symlink, + }) +} + +// New returns the root node of a device filesystem. +func New(ctx context.Context, msrc *fs.MountSource, binderEnabled bool, ashmemEnabled bool) *fs.Inode { + contents := map[string]*fs.Inode{ + "fd": newSymlink(ctx, "/proc/self/fd", msrc), + "stdin": newSymlink(ctx, "/proc/self/fd/0", msrc), + "stdout": newSymlink(ctx, "/proc/self/fd/1", msrc), + "stderr": newSymlink(ctx, "/proc/self/fd/2", msrc), + + "null": newMemDevice(newNullDevice(ctx, fs.RootOwner, 0666), msrc, nullDevMinor), + "zero": newMemDevice(newZeroDevice(ctx, fs.RootOwner, 0666), msrc, zeroDevMinor), + "full": newMemDevice(newFullDevice(ctx, fs.RootOwner, 0666), msrc, fullDevMinor), + + // This is not as good as /dev/random in linux because go + // runtime uses sys_random and /dev/urandom internally. + // According to 'man 4 random', this will be sufficient unless + // application uses this to generate long-lived GPG/SSL/SSH + // keys. + "random": newMemDevice(newRandomDevice(ctx, fs.RootOwner, 0444), msrc, randomDevMinor), + "urandom": newMemDevice(newRandomDevice(ctx, fs.RootOwner, 0444), msrc, urandomDevMinor), + + "shm": tmpfs.NewDir(ctx, nil, fs.RootOwner, fs.FilePermsFromMode(0777), msrc), + + // A devpts is typically mounted at /dev/pts to provide + // pseudoterminal support. Place an empty directory there for + // the devpts to be mounted over. + "pts": newDirectory(ctx, msrc), + // Similarly, applications expect a ptmx device at /dev/ptmx + // connected to the terminals provided by /dev/pts/. Rather + // than creating a device directly (which requires a hairy + // lookup on open to determine if a devpts exists), just create + // a symlink to the ptmx provided by devpts. (The Linux devpts + // documentation recommends this). + // + // If no devpts is mounted, this will simply be a dangling + // symlink, which is fine. + "ptmx": newSymlink(ctx, "pts/ptmx", msrc), + } + + if binderEnabled { + binder := binder.NewDevice(ctx, fs.RootOwner, fs.FilePermsFromMode(0666)) + contents["binder"] = newCharacterDevice(binder, msrc) + } + + if ashmemEnabled { + ashmem := ashmem.NewDevice(ctx, fs.RootOwner, fs.FilePermsFromMode(0666)) + contents["ashmem"] = newCharacterDevice(ashmem, msrc) + } + + iops := ramfs.NewDir(ctx, contents, fs.RootOwner, fs.FilePermsFromMode(0555)) + return fs.NewInode(iops, msrc, fs.StableAttr{ + DeviceID: devDevice.DeviceID(), + InodeID: devDevice.NextIno(), + BlockSize: usermem.PageSize, + Type: fs.Directory, + }) +} + +// readZeros implements fs.FileOperations.Read with infinite null bytes. +type readZeros struct{} + +// Read implements fs.FileOperations.Read. +func (*readZeros) Read(ctx context.Context, file *fs.File, dst usermem.IOSequence, offset int64) (int64, error) { + return dst.ZeroOut(ctx, math.MaxInt64) +} diff --git a/pkg/sentry/fs/dev/dev_state_autogen.go b/pkg/sentry/fs/dev/dev_state_autogen.go new file mode 100755 index 000000000..afe94ff86 --- /dev/null +++ b/pkg/sentry/fs/dev/dev_state_autogen.go @@ -0,0 +1,108 @@ +// automatically generated by stateify. + +package dev + +import ( + "gvisor.googlesource.com/gvisor/pkg/state" +) + +func (x *filesystem) beforeSave() {} +func (x *filesystem) save(m state.Map) { + x.beforeSave() +} + +func (x *filesystem) afterLoad() {} +func (x *filesystem) load(m state.Map) { +} + +func (x *fullDevice) beforeSave() {} +func (x *fullDevice) save(m state.Map) { + x.beforeSave() + m.Save("InodeSimpleAttributes", &x.InodeSimpleAttributes) +} + +func (x *fullDevice) afterLoad() {} +func (x *fullDevice) load(m state.Map) { + m.Load("InodeSimpleAttributes", &x.InodeSimpleAttributes) +} + +func (x *fullFileOperations) beforeSave() {} +func (x *fullFileOperations) save(m state.Map) { + x.beforeSave() +} + +func (x *fullFileOperations) afterLoad() {} +func (x *fullFileOperations) load(m state.Map) { +} + +func (x *nullDevice) beforeSave() {} +func (x *nullDevice) save(m state.Map) { + x.beforeSave() + m.Save("InodeSimpleAttributes", &x.InodeSimpleAttributes) +} + +func (x *nullDevice) afterLoad() {} +func (x *nullDevice) load(m state.Map) { + m.Load("InodeSimpleAttributes", &x.InodeSimpleAttributes) +} + +func (x *nullFileOperations) beforeSave() {} +func (x *nullFileOperations) save(m state.Map) { + x.beforeSave() +} + +func (x *nullFileOperations) afterLoad() {} +func (x *nullFileOperations) load(m state.Map) { +} + +func (x *zeroDevice) beforeSave() {} +func (x *zeroDevice) save(m state.Map) { + x.beforeSave() + m.Save("nullDevice", &x.nullDevice) +} + +func (x *zeroDevice) afterLoad() {} +func (x *zeroDevice) load(m state.Map) { + m.Load("nullDevice", &x.nullDevice) +} + +func (x *zeroFileOperations) beforeSave() {} +func (x *zeroFileOperations) save(m state.Map) { + x.beforeSave() +} + +func (x *zeroFileOperations) afterLoad() {} +func (x *zeroFileOperations) load(m state.Map) { +} + +func (x *randomDevice) beforeSave() {} +func (x *randomDevice) save(m state.Map) { + x.beforeSave() + m.Save("InodeSimpleAttributes", &x.InodeSimpleAttributes) +} + +func (x *randomDevice) afterLoad() {} +func (x *randomDevice) load(m state.Map) { + m.Load("InodeSimpleAttributes", &x.InodeSimpleAttributes) +} + +func (x *randomFileOperations) beforeSave() {} +func (x *randomFileOperations) save(m state.Map) { + x.beforeSave() +} + +func (x *randomFileOperations) afterLoad() {} +func (x *randomFileOperations) load(m state.Map) { +} + +func init() { + state.Register("dev.filesystem", (*filesystem)(nil), state.Fns{Save: (*filesystem).save, Load: (*filesystem).load}) + state.Register("dev.fullDevice", (*fullDevice)(nil), state.Fns{Save: (*fullDevice).save, Load: (*fullDevice).load}) + state.Register("dev.fullFileOperations", (*fullFileOperations)(nil), state.Fns{Save: (*fullFileOperations).save, Load: (*fullFileOperations).load}) + state.Register("dev.nullDevice", (*nullDevice)(nil), state.Fns{Save: (*nullDevice).save, Load: (*nullDevice).load}) + state.Register("dev.nullFileOperations", (*nullFileOperations)(nil), state.Fns{Save: (*nullFileOperations).save, Load: (*nullFileOperations).load}) + state.Register("dev.zeroDevice", (*zeroDevice)(nil), state.Fns{Save: (*zeroDevice).save, Load: (*zeroDevice).load}) + state.Register("dev.zeroFileOperations", (*zeroFileOperations)(nil), state.Fns{Save: (*zeroFileOperations).save, Load: (*zeroFileOperations).load}) + state.Register("dev.randomDevice", (*randomDevice)(nil), state.Fns{Save: (*randomDevice).save, Load: (*randomDevice).load}) + state.Register("dev.randomFileOperations", (*randomFileOperations)(nil), state.Fns{Save: (*randomFileOperations).save, Load: (*randomFileOperations).load}) +} diff --git a/pkg/sentry/fs/dev/device.go b/pkg/sentry/fs/dev/device.go new file mode 100644 index 000000000..9f4e41fc9 --- /dev/null +++ b/pkg/sentry/fs/dev/device.go @@ -0,0 +1,20 @@ +// 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 dev + +import "gvisor.googlesource.com/gvisor/pkg/sentry/device" + +// devDevice is the pseudo-filesystem device. +var devDevice = device.NewAnonDevice() diff --git a/pkg/sentry/fs/dev/fs.go b/pkg/sentry/fs/dev/fs.go new file mode 100644 index 000000000..6096a40f8 --- /dev/null +++ b/pkg/sentry/fs/dev/fs.go @@ -0,0 +1,99 @@ +// 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 dev + +import ( + "strconv" + + "gvisor.googlesource.com/gvisor/pkg/sentry/context" + "gvisor.googlesource.com/gvisor/pkg/sentry/fs" + "gvisor.googlesource.com/gvisor/pkg/syserror" +) + +// Optional key containing boolean flag which specifies if Android Binder IPC should be enabled. +const binderEnabledKey = "binder_enabled" + +// Optional key containing boolean flag which specifies if Android ashmem should be enabled. +const ashmemEnabledKey = "ashmem_enabled" + +// filesystem is a devtmpfs. +// +// +stateify savable +type filesystem struct{} + +var _ fs.Filesystem = (*filesystem)(nil) + +func init() { + fs.RegisterFilesystem(&filesystem{}) +} + +// FilesystemName is the name underwhich the filesystem is registered. +// Name matches drivers/base/devtmpfs.c:dev_fs_type.name. +const FilesystemName = "devtmpfs" + +// Name is the name of the file system. +func (*filesystem) Name() string { + return FilesystemName +} + +// AllowUserMount allows users to mount(2) this file system. +func (*filesystem) AllowUserMount() bool { + return true +} + +// AllowUserList allows this filesystem to be listed in /proc/filesystems. +func (*filesystem) AllowUserList() bool { + return true +} + +// Flags returns that there is nothing special about this file system. +// +// In Linux, devtmpfs does the same thing. +func (*filesystem) Flags() fs.FilesystemFlags { + return 0 +} + +// Mount returns a devtmpfs root that can be positioned in the vfs. +func (f *filesystem) Mount(ctx context.Context, device string, flags fs.MountSourceFlags, data string, _ interface{}) (*fs.Inode, error) { + // device is always ignored. + // devtmpfs backed by ramfs ignores bad options. See fs/ramfs/inode.c:ramfs_parse_options. + // -> we should consider parsing the mode and backing devtmpfs by this. + + // Parse generic comma-separated key=value options. + options := fs.GenericMountSourceOptions(data) + + // binerEnabledKey is optional and binder is disabled by default. + binderEnabled := false + if beStr, exists := options[binderEnabledKey]; exists { + var err error + binderEnabled, err = strconv.ParseBool(beStr) + if err != nil { + return nil, syserror.EINVAL + } + } + + // ashmemEnabledKey is optional and ashmem is disabled by default. + ashmemEnabled := false + if aeStr, exists := options[ashmemEnabledKey]; exists { + var err error + ashmemEnabled, err = strconv.ParseBool(aeStr) + if err != nil { + return nil, syserror.EINVAL + } + } + + // Construct the devtmpfs root. + return New(ctx, fs.NewNonCachingMountSource(f, flags), binderEnabled, ashmemEnabled), nil +} diff --git a/pkg/sentry/fs/dev/full.go b/pkg/sentry/fs/dev/full.go new file mode 100644 index 000000000..8f6c6da2d --- /dev/null +++ b/pkg/sentry/fs/dev/full.go @@ -0,0 +1,81 @@ +// 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 dev + +import ( + "gvisor.googlesource.com/gvisor/pkg/abi/linux" + "gvisor.googlesource.com/gvisor/pkg/sentry/context" + "gvisor.googlesource.com/gvisor/pkg/sentry/fs" + "gvisor.googlesource.com/gvisor/pkg/sentry/fs/fsutil" + "gvisor.googlesource.com/gvisor/pkg/sentry/usermem" + "gvisor.googlesource.com/gvisor/pkg/syserror" + "gvisor.googlesource.com/gvisor/pkg/waiter" +) + +// fullDevice is used to implement /dev/full. +// +// +stateify savable +type fullDevice struct { + fsutil.InodeGenericChecker `state:"nosave"` + fsutil.InodeNoExtendedAttributes `state:"nosave"` + fsutil.InodeNoopAllocate `state:"nosave"` + fsutil.InodeNoopRelease `state:"nosave"` + fsutil.InodeNoopTruncate `state:"nosave"` + fsutil.InodeNoopWriteOut `state:"nosave"` + fsutil.InodeNotDirectory `state:"nosave"` + fsutil.InodeNotMappable `state:"nosave"` + fsutil.InodeNotSocket `state:"nosave"` + fsutil.InodeNotSymlink `state:"nosave"` + fsutil.InodeVirtual `state:"nosave"` + + fsutil.InodeSimpleAttributes +} + +var _ fs.InodeOperations = (*fullDevice)(nil) + +func newFullDevice(ctx context.Context, owner fs.FileOwner, mode linux.FileMode) *fullDevice { + f := &fullDevice{ + InodeSimpleAttributes: fsutil.NewInodeSimpleAttributes(ctx, owner, fs.FilePermsFromMode(mode), linux.TMPFS_MAGIC), + } + return f +} + +// GetFile implements fs.InodeOperations.GetFile. +func (f *fullDevice) GetFile(ctx context.Context, dirent *fs.Dirent, flags fs.FileFlags) (*fs.File, error) { + flags.Pread = true + return fs.NewFile(ctx, dirent, flags, &fullFileOperations{}), nil +} + +// +stateify savable +type fullFileOperations struct { + waiter.AlwaysReady `state:"nosave"` + fsutil.FileGenericSeek `state:"nosave"` + fsutil.FileNoIoctl `state:"nosave"` + fsutil.FileNoMMap `state:"nosave"` + fsutil.FileNoopFlush `state:"nosave"` + fsutil.FileNoopFsync `state:"nosave"` + fsutil.FileNoopRelease `state:"nosave"` + fsutil.FileNotDirReaddir `state:"nosave"` + fsutil.FileUseInodeUnstableAttr `state:"nosave"` + fsutil.FileNoSplice `state:"nosave"` + readZeros `state:"nosave"` +} + +var _ fs.FileOperations = (*fullFileOperations)(nil) + +// Write implements FileOperations.Write. +func (*fullFileOperations) Write(context.Context, *fs.File, usermem.IOSequence, int64) (int64, error) { + return 0, syserror.ENOSPC +} diff --git a/pkg/sentry/fs/dev/null.go b/pkg/sentry/fs/dev/null.go new file mode 100644 index 000000000..3f1accef8 --- /dev/null +++ b/pkg/sentry/fs/dev/null.go @@ -0,0 +1,130 @@ +// 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 dev + +import ( + "gvisor.googlesource.com/gvisor/pkg/abi/linux" + "gvisor.googlesource.com/gvisor/pkg/sentry/context" + "gvisor.googlesource.com/gvisor/pkg/sentry/fs" + "gvisor.googlesource.com/gvisor/pkg/sentry/fs/fsutil" + "gvisor.googlesource.com/gvisor/pkg/sentry/memmap" + "gvisor.googlesource.com/gvisor/pkg/sentry/mm" + "gvisor.googlesource.com/gvisor/pkg/sentry/pgalloc" + "gvisor.googlesource.com/gvisor/pkg/waiter" +) + +// +stateify savable +type nullDevice struct { + fsutil.InodeGenericChecker `state:"nosave"` + fsutil.InodeNoExtendedAttributes `state:"nosave"` + fsutil.InodeNoopAllocate `state:"nosave"` + fsutil.InodeNoopRelease `state:"nosave"` + fsutil.InodeNoopTruncate `state:"nosave"` + fsutil.InodeNoopWriteOut `state:"nosave"` + fsutil.InodeNotDirectory `state:"nosave"` + fsutil.InodeNotMappable `state:"nosave"` + fsutil.InodeNotSocket `state:"nosave"` + fsutil.InodeNotSymlink `state:"nosave"` + fsutil.InodeVirtual `state:"nosave"` + + fsutil.InodeSimpleAttributes +} + +var _ fs.InodeOperations = (*nullDevice)(nil) + +func newNullDevice(ctx context.Context, owner fs.FileOwner, mode linux.FileMode) *nullDevice { + n := &nullDevice{ + InodeSimpleAttributes: fsutil.NewInodeSimpleAttributes(ctx, owner, fs.FilePermsFromMode(mode), linux.TMPFS_MAGIC), + } + return n +} + +// GetFile implements fs.FileOperations.GetFile. +func (n *nullDevice) GetFile(ctx context.Context, dirent *fs.Dirent, flags fs.FileFlags) (*fs.File, error) { + flags.Pread = true + flags.Pwrite = true + + return fs.NewFile(ctx, dirent, flags, &nullFileOperations{}), nil +} + +// +stateify savable +type nullFileOperations struct { + fsutil.FileGenericSeek `state:"nosave"` + fsutil.FileNoIoctl `state:"nosave"` + fsutil.FileNoMMap `state:"nosave"` + fsutil.FileNoSplice `state:"nosave"` + fsutil.FileNoopFlush `state:"nosave"` + fsutil.FileNoopFsync `state:"nosave"` + fsutil.FileNoopRead `state:"nosave"` + fsutil.FileNoopRelease `state:"nosave"` + fsutil.FileNoopWrite `state:"nosave"` + fsutil.FileNotDirReaddir `state:"nosave"` + fsutil.FileUseInodeUnstableAttr `state:"nosave"` + waiter.AlwaysReady `state:"nosave"` +} + +var _ fs.FileOperations = (*nullFileOperations)(nil) + +// +stateify savable +type zeroDevice struct { + nullDevice +} + +var _ fs.InodeOperations = (*zeroDevice)(nil) + +func newZeroDevice(ctx context.Context, owner fs.FileOwner, mode linux.FileMode) *zeroDevice { + zd := &zeroDevice{ + nullDevice: nullDevice{ + InodeSimpleAttributes: fsutil.NewInodeSimpleAttributes(ctx, owner, fs.FilePermsFromMode(mode), linux.TMPFS_MAGIC), + }, + } + return zd +} + +// GetFile implements fs.FileOperations.GetFile. +func (zd *zeroDevice) GetFile(ctx context.Context, dirent *fs.Dirent, flags fs.FileFlags) (*fs.File, error) { + flags.Pread = true + flags.Pwrite = true + + return fs.NewFile(ctx, dirent, flags, &zeroFileOperations{}), nil +} + +// +stateify savable +type zeroFileOperations struct { + fsutil.FileGenericSeek `state:"nosave"` + fsutil.FileNoIoctl `state:"nosave"` + fsutil.FileNoSplice `state:"nosave"` + fsutil.FileNoopFlush `state:"nosave"` + fsutil.FileNoopFsync `state:"nosave"` + fsutil.FileNoopRelease `state:"nosave"` + fsutil.FileNoopWrite `state:"nosave"` + fsutil.FileNotDirReaddir `state:"nosave"` + fsutil.FileUseInodeUnstableAttr `state:"nosave"` + waiter.AlwaysReady `state:"nosave"` + readZeros `state:"nosave"` +} + +var _ fs.FileOperations = (*zeroFileOperations)(nil) + +// ConfigureMMap implements fs.FileOperations.ConfigureMMap. +func (*zeroFileOperations) ConfigureMMap(ctx context.Context, file *fs.File, opts *memmap.MMapOpts) error { + m, err := mm.NewSharedAnonMappable(opts.Length, pgalloc.MemoryFileProviderFromContext(ctx)) + if err != nil { + return err + } + opts.MappingIdentity = m + opts.Mappable = m + return nil +} diff --git a/pkg/sentry/fs/dev/random.go b/pkg/sentry/fs/dev/random.go new file mode 100644 index 000000000..e5a01a906 --- /dev/null +++ b/pkg/sentry/fs/dev/random.go @@ -0,0 +1,79 @@ +// 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 dev + +import ( + "gvisor.googlesource.com/gvisor/pkg/abi/linux" + "gvisor.googlesource.com/gvisor/pkg/rand" + "gvisor.googlesource.com/gvisor/pkg/sentry/context" + "gvisor.googlesource.com/gvisor/pkg/sentry/fs" + "gvisor.googlesource.com/gvisor/pkg/sentry/fs/fsutil" + "gvisor.googlesource.com/gvisor/pkg/sentry/safemem" + "gvisor.googlesource.com/gvisor/pkg/sentry/usermem" + "gvisor.googlesource.com/gvisor/pkg/waiter" +) + +// +stateify savable +type randomDevice struct { + fsutil.InodeGenericChecker `state:"nosave"` + fsutil.InodeNoExtendedAttributes `state:"nosave"` + fsutil.InodeNoopAllocate `state:"nosave"` + fsutil.InodeNoopRelease `state:"nosave"` + fsutil.InodeNoopTruncate `state:"nosave"` + fsutil.InodeNoopWriteOut `state:"nosave"` + fsutil.InodeNotDirectory `state:"nosave"` + fsutil.InodeNotMappable `state:"nosave"` + fsutil.InodeNotSocket `state:"nosave"` + fsutil.InodeNotSymlink `state:"nosave"` + fsutil.InodeVirtual `state:"nosave"` + + fsutil.InodeSimpleAttributes +} + +var _ fs.InodeOperations = (*randomDevice)(nil) + +func newRandomDevice(ctx context.Context, owner fs.FileOwner, mode linux.FileMode) *randomDevice { + r := &randomDevice{ + InodeSimpleAttributes: fsutil.NewInodeSimpleAttributes(ctx, owner, fs.FilePermsFromMode(mode), linux.TMPFS_MAGIC), + } + return r +} + +// GetFile implements fs.InodeOperations.GetFile. +func (*randomDevice) GetFile(ctx context.Context, dirent *fs.Dirent, flags fs.FileFlags) (*fs.File, error) { + return fs.NewFile(ctx, dirent, flags, &randomFileOperations{}), nil +} + +// +stateify savable +type randomFileOperations struct { + fsutil.FileGenericSeek `state:"nosave"` + fsutil.FileNoIoctl `state:"nosave"` + fsutil.FileNoMMap `state:"nosave"` + fsutil.FileNoSplice `state:"nosave"` + fsutil.FileNoopFlush `state:"nosave"` + fsutil.FileNoopFsync `state:"nosave"` + fsutil.FileNoopRelease `state:"nosave"` + fsutil.FileNoopWrite `state:"nosave"` + fsutil.FileNotDirReaddir `state:"nosave"` + fsutil.FileUseInodeUnstableAttr `state:"nosave"` + waiter.AlwaysReady `state:"nosave"` +} + +var _ fs.FileOperations = (*randomFileOperations)(nil) + +// Read implements fs.FileOperations.Read. +func (*randomFileOperations) Read(ctx context.Context, _ *fs.File, dst usermem.IOSequence, _ int64) (int64, error) { + return dst.CopyOutFrom(ctx, safemem.FromIOReader{rand.Reader}) +} |