diff options
| -rw-r--r-- | pkg/abi/linux/dev.go | 4 | ||||
| -rw-r--r-- | pkg/sentry/devices/miscdev/BUILD | 20 | ||||
| -rw-r--r-- | pkg/sentry/devices/miscdev/fuse.go | 78 | ||||
| -rw-r--r-- | pkg/sentry/devices/miscdev/miscdev.go | 54 | ||||
| -rw-r--r-- | test/syscalls/linux/dev.cc | 20 |
5 files changed, 176 insertions, 0 deletions
diff --git a/pkg/abi/linux/dev.go b/pkg/abi/linux/dev.go index fa3ae5f18..192e2093b 100644 --- a/pkg/abi/linux/dev.go +++ b/pkg/abi/linux/dev.go @@ -46,6 +46,10 @@ const ( // TTYAUX_MAJOR is the major device number for alternate TTY devices. TTYAUX_MAJOR = 5 + // MISC_MAJOR is the major device number for non-serial mice, misc feature + // devices. + MISC_MAJOR = 10 + // UNIX98_PTY_MASTER_MAJOR is the initial major device number for // Unix98 PTY masters. UNIX98_PTY_MASTER_MAJOR = 128 diff --git a/pkg/sentry/devices/miscdev/BUILD b/pkg/sentry/devices/miscdev/BUILD new file mode 100644 index 000000000..aaa76c5d2 --- /dev/null +++ b/pkg/sentry/devices/miscdev/BUILD @@ -0,0 +1,20 @@ +load("//tools:defs.bzl", "go_library") + +licenses(["notice"]) + +go_library( + name = "miscdev", + srcs = [ + "fuse.go", + "miscdev.go", + ], + visibility = ["//pkg/sentry:internal"], + deps = [ + "//pkg/abi/linux", + "//pkg/context", + "//pkg/sentry/fsimpl/devtmpfs", + "//pkg/sentry/vfs", + "//pkg/syserror", + "//pkg/usermem", + ], +) diff --git a/pkg/sentry/devices/miscdev/fuse.go b/pkg/sentry/devices/miscdev/fuse.go new file mode 100644 index 000000000..d0a963191 --- /dev/null +++ b/pkg/sentry/devices/miscdev/fuse.go @@ -0,0 +1,78 @@ +// 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 miscdev + +import ( + "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/sentry/vfs" + "gvisor.dev/gvisor/pkg/syserror" + "gvisor.dev/gvisor/pkg/usermem" +) + +const fuseDevMinor = 229 + +// fuseDevice implements vfs.Device for /dev/fuse. +type fuseDevice struct{} + +// Open implements vfs.Device.Open. +func (fuseDevice) Open(ctx context.Context, mnt *vfs.Mount, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { + var fd FUSEDeviceFile + if err := fd.vfsfd.Init(&fd, opts.Flags, mnt, vfsd, &vfs.FileDescriptionOptions{ + UseDentryMetadata: true, + }); err != nil { + return nil, err + } + return &fd.vfsfd, nil +} + +// FUSEDeviceFile implements vfs.FileDescriptionImpl for /dev/fuse. +type FUSEDeviceFile struct { + vfsfd vfs.FileDescription + vfs.FileDescriptionDefaultImpl + vfs.DentryMetadataFileDescriptionImpl + vfs.NoLockFD + + // TODO(gvisor.dev/issue/2987): Add all the data structures needed to enqueue + // and deque requests, control synchronization and establish communication + // between the FUSE kernel module and the /dev/fuse character device. +} + +// Release implements vfs.FileDescriptionImpl.Release. +func (fd *FUSEDeviceFile) Release() {} + +// PRead implements vfs.FileDescriptionImpl.PRead. +func (fd *FUSEDeviceFile) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) { + return 0, syserror.ENOSYS +} + +// Read implements vfs.FileDescriptionImpl.Read. +func (fd *FUSEDeviceFile) Read(ctx context.Context, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) { + return 0, syserror.ENOSYS +} + +// PWrite implements vfs.FileDescriptionImpl.PWrite. +func (fd *FUSEDeviceFile) PWrite(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) { + return 0, syserror.ENOSYS +} + +// Write implements vfs.FileDescriptionImpl.Write. +func (fd *FUSEDeviceFile) Write(ctx context.Context, src usermem.IOSequence, opts vfs.WriteOptions) (int64, error) { + return 0, syserror.ENOSYS +} + +// Seek implements vfs.FileDescriptionImpl.Seek. +func (fd *FUSEDeviceFile) Seek(ctx context.Context, offset int64, whence int32) (int64, error) { + return 0, syserror.ENOSYS +} diff --git a/pkg/sentry/devices/miscdev/miscdev.go b/pkg/sentry/devices/miscdev/miscdev.go new file mode 100644 index 000000000..500d92ed9 --- /dev/null +++ b/pkg/sentry/devices/miscdev/miscdev.go @@ -0,0 +1,54 @@ +// 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 miscdev implements "misc" character devices, as implemented in Linux +// by drivers/char/misc.c and fs/fuse/dev.c. +package miscdev + +import ( + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/sentry/fsimpl/devtmpfs" + "gvisor.dev/gvisor/pkg/sentry/vfs" +) + +// miscDevMajor is the major device number for devices defined in this package. +const miscDevMajor = linux.MISC_MAJOR + +// Register registers all devices implemented by this package in vfsObj. +func Register(vfsObj *vfs.VirtualFilesystem) error { + for minor, dev := range map[uint32]vfs.Device{ + fuseDevMinor: fuseDevice{}, + } { + if err := vfsObj.RegisterDevice(vfs.CharDevice, miscDevMajor, minor, dev, &vfs.RegisterDeviceOptions{ + GroupName: "misc", + }); err != nil { + return err + } + } + return nil +} + +// CreateDevtmpfsFiles creates device special files in dev representing all +// devices implemented by this package. +func CreateDevtmpfsFiles(ctx context.Context, dev *devtmpfs.Accessor) error { + for minor, name := range map[uint32]string{ + fuseDevMinor: "fuse", + } { + if err := dev.CreateDeviceFile(ctx, name, vfs.CharDevice, miscDevMajor, minor, 0666 /* mode */); err != nil { + return err + } + } + return nil +} diff --git a/test/syscalls/linux/dev.cc b/test/syscalls/linux/dev.cc index 4dd302eed..82b115981 100644 --- a/test/syscalls/linux/dev.cc +++ b/test/syscalls/linux/dev.cc @@ -146,7 +146,27 @@ TEST(DevTest, WriteDevFull) { EXPECT_THAT(WriteFd(fd.get(), "a", 1), SyscallFailsWithErrno(ENOSPC)); } +TEST(DevTest, ReadDevFuse) { + SKIP_IF(IsRunningWithVFS1()); + + const FileDescriptor fd = + ASSERT_NO_ERRNO_AND_VALUE(Open("/dev/fuse", O_RDONLY)); + std::vector<char> buf(1); + EXPECT_THAT(ReadFd(fd.get(), buf.data(), sizeof(buf)), SyscallFailsWithErrno(ENOSYS)); +} + +TEST(DevTest, WriteDevFuse) { + SKIP_IF(IsRunningWithVFS1()); + + const FileDescriptor fd = + ASSERT_NO_ERRNO_AND_VALUE(Open("/dev/fuse", O_WRONLY)); + const char* testStr = "test"; + EXPECT_THAT(WriteFd(fd.get(), testStr, sizeof(testStr)), SyscallFailsWithErrno(ENOSYS)); +} + TEST(DevTest, TTYExists) { + SKIP_IF(!IsRunningWithVFS1()); + struct stat statbuf = {}; ASSERT_THAT(stat("/dev/tty", &statbuf), SyscallSucceeds()); // Check that it's a character device with rw-rw-rw- permissions. |