diff options
| -rw-r--r-- | pkg/sentry/fs/dev/BUILD | 1 | ||||
| -rw-r--r-- | pkg/sentry/fs/dev/dev.go | 20 | ||||
| -rw-r--r-- | pkg/sentry/fs/dev/tty.go | 79 | ||||
| -rw-r--r-- | test/syscalls/linux/dev.cc | 7 |
4 files changed, 102 insertions, 5 deletions
diff --git a/pkg/sentry/fs/dev/BUILD b/pkg/sentry/fs/dev/BUILD index 59de615fb..80e106e6f 100644 --- a/pkg/sentry/fs/dev/BUILD +++ b/pkg/sentry/fs/dev/BUILD @@ -11,6 +11,7 @@ go_library( "full.go", "null.go", "random.go", + "tty.go", ], importpath = "gvisor.dev/gvisor/pkg/sentry/fs/dev", visibility = ["//pkg/sentry:internal"], diff --git a/pkg/sentry/fs/dev/dev.go b/pkg/sentry/fs/dev/dev.go index d4bbd9807..f739c476c 100644 --- a/pkg/sentry/fs/dev/dev.go +++ b/pkg/sentry/fs/dev/dev.go @@ -38,12 +38,20 @@ const ( urandomDevMinor uint32 = 9 ) -func newCharacterDevice(ctx context.Context, iops fs.InodeOperations, msrc *fs.MountSource) *fs.Inode { +// TTY major device number comes from include/uapi/linux/major.h. +const ( + ttyDevMinor = 0 + ttyDevMajor = 5 +) + +func newCharacterDevice(ctx context.Context, iops fs.InodeOperations, msrc *fs.MountSource, major uint16, minor uint32) *fs.Inode { return fs.NewInode(ctx, iops, msrc, fs.StableAttr{ - DeviceID: devDevice.DeviceID(), - InodeID: devDevice.NextIno(), - BlockSize: usermem.PageSize, - Type: fs.CharacterDevice, + DeviceID: devDevice.DeviceID(), + InodeID: devDevice.NextIno(), + BlockSize: usermem.PageSize, + Type: fs.CharacterDevice, + DeviceFileMajor: major, + DeviceFileMinor: minor, }) } @@ -114,6 +122,8 @@ func New(ctx context.Context, msrc *fs.MountSource) *fs.Inode { // If no devpts is mounted, this will simply be a dangling // symlink, which is fine. "ptmx": newSymlink(ctx, "pts/ptmx", msrc), + + "tty": newCharacterDevice(ctx, newTTYDevice(ctx, fs.RootOwner, 0666), msrc, ttyDevMajor, ttyDevMinor), } iops := ramfs.NewDir(ctx, contents, fs.RootOwner, fs.FilePermsFromMode(0555)) diff --git a/pkg/sentry/fs/dev/tty.go b/pkg/sentry/fs/dev/tty.go new file mode 100644 index 000000000..e1e4fa2cf --- /dev/null +++ b/pkg/sentry/fs/dev/tty.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.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/rand" + "gvisor.dev/gvisor/pkg/sentry/context" + "gvisor.dev/gvisor/pkg/sentry/fs" + "gvisor.dev/gvisor/pkg/sentry/fs/fsutil" + "gvisor.dev/gvisor/pkg/sentry/safemem" + "gvisor.dev/gvisor/pkg/sentry/usermem" + "gvisor.dev/gvisor/pkg/waiter" +) + +// +stateify savable +type ttyInodeOperations 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 = (*ttyInodeOperations)(nil) + +func newTTYDevice(ctx context.Context, owner fs.FileOwner, mode linux.FileMode) *ttyInodeOperations { + return &ttyInodeOperations{ + InodeSimpleAttributes: fsutil.NewInodeSimpleAttributes(ctx, owner, fs.FilePermsFromMode(mode), linux.TMPFS_MAGIC), + } +} + +// GetFile implements fs.InodeOperations.GetFile. +func (*ttyInodeOperations) GetFile(ctx context.Context, dirent *fs.Dirent, flags fs.FileFlags) (*fs.File, error) { + return fs.NewFile(ctx, dirent, flags, &ttyFileOperations{}), nil +} + +// +stateify savable +type ttyFileOperations struct { + fsutil.FileNoSeek `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.FileNoopRead `state:"nosave"` + fsutil.FileNotDirReaddir `state:"nosave"` + fsutil.FileUseInodeUnstableAttr `state:"nosave"` + waiter.AlwaysReady `state:"nosave"` +} + +var _ fs.FileOperations = (*ttyFileOperations)(nil) + +// Read implements fs.FileOperations.Read. +func (*ttyFileOperations) Read(ctx context.Context, _ *fs.File, dst usermem.IOSequence, _ int64) (int64, error) { + return dst.CopyOutFrom(ctx, safemem.FromIOReader{rand.Reader}) +} diff --git a/test/syscalls/linux/dev.cc b/test/syscalls/linux/dev.cc index b86ebe233..7b1dd14ef 100644 --- a/test/syscalls/linux/dev.cc +++ b/test/syscalls/linux/dev.cc @@ -13,6 +13,8 @@ // limitations under the License. #include <fcntl.h> +#include <sys/stat.h> +#include <sys/types.h> #include <unistd.h> #include <vector> @@ -143,6 +145,11 @@ TEST(DevTest, WriteDevFull) { EXPECT_THAT(WriteFd(fd.get(), "a", 1), SyscallFailsWithErrno(ENOSPC)); } +TEST(DevTest, TTYExists) { + struct stat statbuf = {}; + ASSERT_THAT(stat("/dev/tty", &statbuf), SyscallSucceeds()); +} + } // namespace } // namespace testing |