diff options
Diffstat (limited to 'pkg/sentry/fsimpl/proc/task_fds.go')
| -rw-r--r-- | pkg/sentry/fsimpl/proc/task_fds.go | 287 |
1 files changed, 0 insertions, 287 deletions
diff --git a/pkg/sentry/fsimpl/proc/task_fds.go b/pkg/sentry/fsimpl/proc/task_fds.go deleted file mode 100644 index 76bfc5307..000000000 --- a/pkg/sentry/fsimpl/proc/task_fds.go +++ /dev/null @@ -1,287 +0,0 @@ -// 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 proc - -import ( - "bytes" - "fmt" - "sort" - "strconv" - - "gvisor.dev/gvisor/pkg/abi/linux" - "gvisor.dev/gvisor/pkg/context" - "gvisor.dev/gvisor/pkg/refs" - "gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs" - "gvisor.dev/gvisor/pkg/sentry/kernel" - "gvisor.dev/gvisor/pkg/sentry/kernel/auth" - "gvisor.dev/gvisor/pkg/sentry/vfs" - "gvisor.dev/gvisor/pkg/syserror" -) - -type fdDir struct { - inoGen InoGenerator - task *kernel.Task - - // When produceSymlinks is set, dirents produces for the FDs are reported - // as symlink. Otherwise, they are reported as regular files. - produceSymlink bool -} - -func (i *fdDir) lookup(name string) (*vfs.FileDescription, kernel.FDFlags, error) { - fd, err := strconv.ParseUint(name, 10, 64) - if err != nil { - return nil, kernel.FDFlags{}, syserror.ENOENT - } - - var ( - file *vfs.FileDescription - flags kernel.FDFlags - ) - i.task.WithMuLocked(func(t *kernel.Task) { - if fdTable := t.FDTable(); fdTable != nil { - file, flags = fdTable.GetVFS2(int32(fd)) - } - }) - if file == nil { - return nil, kernel.FDFlags{}, syserror.ENOENT - } - return file, flags, nil -} - -// IterDirents implements kernfs.inodeDynamicLookup. -func (i *fdDir) IterDirents(ctx context.Context, cb vfs.IterDirentsCallback, absOffset, relOffset int64) (int64, error) { - var fds []int32 - i.task.WithMuLocked(func(t *kernel.Task) { - if fdTable := t.FDTable(); fdTable != nil { - fds = fdTable.GetFDs() - } - }) - - offset := absOffset + relOffset - typ := uint8(linux.DT_REG) - if i.produceSymlink { - typ = linux.DT_LNK - } - - // Find the appropriate starting point. - idx := sort.Search(len(fds), func(i int) bool { return fds[i] >= int32(relOffset) }) - if idx >= len(fds) { - return offset, nil - } - for _, fd := range fds[idx:] { - dirent := vfs.Dirent{ - Name: strconv.FormatUint(uint64(fd), 10), - Type: typ, - Ino: i.inoGen.NextIno(), - NextOff: offset + 1, - } - if err := cb.Handle(dirent); err != nil { - return offset, err - } - offset++ - } - return offset, nil -} - -// fdDirInode represents the inode for /proc/[pid]/fd directory. -// -// +stateify savable -type fdDirInode struct { - kernfs.InodeNotSymlink - kernfs.InodeDirectoryNoNewChildren - kernfs.InodeAttrs - kernfs.OrderedChildren - kernfs.AlwaysValid - fdDir -} - -var _ kernfs.Inode = (*fdDirInode)(nil) - -func newFDDirInode(task *kernel.Task, inoGen InoGenerator) *kernfs.Dentry { - inode := &fdDirInode{ - fdDir: fdDir{ - inoGen: inoGen, - task: task, - produceSymlink: true, - }, - } - inode.InodeAttrs.Init(task.Credentials(), inoGen.NextIno(), linux.ModeDirectory|0555) - - dentry := &kernfs.Dentry{} - dentry.Init(inode) - inode.OrderedChildren.Init(kernfs.OrderedChildrenOptions{}) - - return dentry -} - -// Lookup implements kernfs.inodeDynamicLookup. -func (i *fdDirInode) Lookup(ctx context.Context, name string) (*vfs.Dentry, error) { - file, _, err := i.lookup(name) - if err != nil { - return nil, err - } - taskDentry := newFDSymlink(i.task.Credentials(), file, i.inoGen.NextIno()) - return taskDentry.VFSDentry(), nil -} - -// Open implements kernfs.Inode. -func (i *fdDirInode) Open(rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { - fd := &kernfs.GenericDirectoryFD{} - fd.Init(rp.Mount(), vfsd, &i.OrderedChildren, &opts) - return fd.VFSFileDescription(), nil -} - -// CheckPermissions implements kernfs.Inode. -// -// This is to match Linux, which uses a special permission handler to guarantee -// that a process can still access /proc/self/fd after it has executed -// setuid. See fs/proc/fd.c:proc_fd_permission. -func (i *fdDirInode) CheckPermissions(ctx context.Context, creds *auth.Credentials, ats vfs.AccessTypes) error { - err := i.InodeAttrs.CheckPermissions(ctx, creds, ats) - if err == nil { - // Access granted, no extra check needed. - return nil - } - if t := kernel.TaskFromContext(ctx); t != nil { - // Allow access if the task trying to access it is in the thread group - // corresponding to this directory. - if i.task.ThreadGroup() == t.ThreadGroup() { - // Access granted (overridden). - return nil - } - } - return err -} - -// fdSymlink is an symlink for the /proc/[pid]/fd/[fd] file. -// -// +stateify savable -type fdSymlink struct { - refs.AtomicRefCount - kernfs.InodeAttrs - kernfs.InodeSymlink - - file *vfs.FileDescription -} - -var _ kernfs.Inode = (*fdSymlink)(nil) - -func newFDSymlink(creds *auth.Credentials, file *vfs.FileDescription, ino uint64) *kernfs.Dentry { - file.IncRef() - inode := &fdSymlink{file: file} - inode.Init(creds, ino, linux.ModeSymlink|0777) - - d := &kernfs.Dentry{} - d.Init(inode) - return d -} - -func (s *fdSymlink) Readlink(ctx context.Context) (string, error) { - root := vfs.RootFromContext(ctx) - defer root.DecRef() - - vfsObj := s.file.VirtualDentry().Mount().Filesystem().VirtualFilesystem() - return vfsObj.PathnameWithDeleted(ctx, root, s.file.VirtualDentry()) -} - -func (s *fdSymlink) DecRef() { - s.AtomicRefCount.DecRefWithDestructor(func() { - s.Destroy() - }) -} - -func (s *fdSymlink) Destroy() { - s.file.DecRef() -} - -// fdInfoDirInode represents the inode for /proc/[pid]/fdinfo directory. -// -// +stateify savable -type fdInfoDirInode struct { - kernfs.InodeNotSymlink - kernfs.InodeDirectoryNoNewChildren - kernfs.InodeAttrs - kernfs.OrderedChildren - kernfs.AlwaysValid - fdDir -} - -var _ kernfs.Inode = (*fdInfoDirInode)(nil) - -func newFDInfoDirInode(task *kernel.Task, inoGen InoGenerator) *kernfs.Dentry { - inode := &fdInfoDirInode{ - fdDir: fdDir{ - inoGen: inoGen, - task: task, - }, - } - inode.InodeAttrs.Init(task.Credentials(), inoGen.NextIno(), linux.ModeDirectory|0555) - - dentry := &kernfs.Dentry{} - dentry.Init(inode) - inode.OrderedChildren.Init(kernfs.OrderedChildrenOptions{}) - - return dentry -} - -// Lookup implements kernfs.inodeDynamicLookup. -func (i *fdInfoDirInode) Lookup(ctx context.Context, name string) (*vfs.Dentry, error) { - file, flags, err := i.lookup(name) - if err != nil { - return nil, err - } - - data := &fdInfoData{file: file, flags: flags} - dentry := newTaskOwnedFile(i.task, i.inoGen.NextIno(), 0444, data) - return dentry.VFSDentry(), nil -} - -// Open implements kernfs.Inode. -func (i *fdInfoDirInode) Open(rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { - fd := &kernfs.GenericDirectoryFD{} - fd.Init(rp.Mount(), vfsd, &i.OrderedChildren, &opts) - return fd.VFSFileDescription(), nil -} - -// fdInfoData implements vfs.DynamicBytesSource for /proc/[pid]/fdinfo/[fd]. -// -// +stateify savable -type fdInfoData struct { - kernfs.DynamicBytesFile - refs.AtomicRefCount - - file *vfs.FileDescription - flags kernel.FDFlags -} - -var _ dynamicInode = (*fdInfoData)(nil) - -func (d *fdInfoData) DecRef() { - d.AtomicRefCount.DecRefWithDestructor(d.destroy) -} - -func (d *fdInfoData) destroy() { - d.file.DecRef() -} - -// Generate implements vfs.DynamicBytesSource.Generate. -func (d *fdInfoData) Generate(ctx context.Context, buf *bytes.Buffer) error { - // TODO(b/121266871): Include pos, locks, and other data. For now we only - // have flags. - // See https://www.kernel.org/doc/Documentation/filesystems/proc.txt - flags := uint(d.file.StatusFlags()) | d.flags.ToLinuxFileFlags() - fmt.Fprintf(buf, "flags:\t0%o\n", flags) - return nil -} |