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authorkevin.xu <cming.xu@gmail.com>2020-04-27 21:51:31 +0800
committerGitHub <noreply@github.com>2020-04-27 21:51:31 +0800
commite896ca54db67524afc20b644d43c72185e72dc0e (patch)
tree2a16f3a62a5cafd098f1f028c621f1b655589d69 /pkg/sentry/vfs/syscalls.go
parent1f19624fa127d7d59cabe29593cc80b7fe6c81f8 (diff)
parent3c67754663f424f2ebbc0ff2a4c80e30618d5355 (diff)
Merge pull request #1 from google/master
catch up
Diffstat (limited to 'pkg/sentry/vfs/syscalls.go')
-rw-r--r--pkg/sentry/vfs/syscalls.go235
1 files changed, 0 insertions, 235 deletions
diff --git a/pkg/sentry/vfs/syscalls.go b/pkg/sentry/vfs/syscalls.go
deleted file mode 100644
index abde0feaa..000000000
--- a/pkg/sentry/vfs/syscalls.go
+++ /dev/null
@@ -1,235 +0,0 @@
-// Copyright 2019 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 vfs
-
-import (
- "gvisor.dev/gvisor/pkg/abi/linux"
- "gvisor.dev/gvisor/pkg/sentry/context"
- "gvisor.dev/gvisor/pkg/sentry/kernel/auth"
- "gvisor.dev/gvisor/pkg/syserror"
-)
-
-// PathOperation specifies the path operated on by a VFS method.
-//
-// PathOperation is passed to VFS methods by pointer to reduce memory copying:
-// it's somewhat large and should never escape. (Options structs are passed by
-// pointer to VFS and FileDescription methods for the same reason.)
-type PathOperation struct {
- // Root is the VFS root. References on Root are borrowed from the provider
- // of the PathOperation.
- //
- // Invariants: Root.Ok().
- Root VirtualDentry
-
- // Start is the starting point for the path traversal. References on Start
- // are borrowed from the provider of the PathOperation (i.e. the caller of
- // the VFS method to which the PathOperation was passed).
- //
- // Invariants: Start.Ok(). If Pathname.Absolute, then Start == Root.
- Start VirtualDentry
-
- // Path is the pathname traversed by this operation.
- Pathname string
-
- // If FollowFinalSymlink is true, and the Dentry traversed by the final
- // path component represents a symbolic link, the symbolic link should be
- // followed.
- FollowFinalSymlink bool
-}
-
-// GetDentryAt returns a VirtualDentry representing the given path, at which a
-// file must exist. A reference is taken on the returned VirtualDentry.
-func (vfs *VirtualFilesystem) GetDentryAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, opts *GetDentryOptions) (VirtualDentry, error) {
- rp, err := vfs.getResolvingPath(creds, pop)
- if err != nil {
- return VirtualDentry{}, err
- }
- for {
- d, err := rp.mount.fs.impl.GetDentryAt(ctx, rp, *opts)
- if err == nil {
- vd := VirtualDentry{
- mount: rp.mount,
- dentry: d,
- }
- rp.mount.incRef()
- vfs.putResolvingPath(rp)
- return vd, nil
- }
- if !rp.handleError(err) {
- vfs.putResolvingPath(rp)
- return VirtualDentry{}, err
- }
- }
-}
-
-// MkdirAt creates a directory at the given path.
-func (vfs *VirtualFilesystem) MkdirAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, opts *MkdirOptions) error {
- // "Under Linux, apart from the permission bits, the S_ISVTX mode bit is
- // also honored." - mkdir(2)
- opts.Mode &= 01777
- rp, err := vfs.getResolvingPath(creds, pop)
- if err != nil {
- return err
- }
- for {
- err := rp.mount.fs.impl.MkdirAt(ctx, rp, *opts)
- if err == nil {
- vfs.putResolvingPath(rp)
- return nil
- }
- if !rp.handleError(err) {
- vfs.putResolvingPath(rp)
- return err
- }
- }
-}
-
-// MknodAt creates a file of the given mode at the given path. It returns an
-// error from the syserror package.
-func (vfs *VirtualFilesystem) MknodAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, opts *MknodOptions) error {
- rp, err := vfs.getResolvingPath(creds, pop)
- if err != nil {
- return nil
- }
- for {
- if err = rp.mount.fs.impl.MknodAt(ctx, rp, *opts); err == nil {
- vfs.putResolvingPath(rp)
- return nil
- }
- // Handle mount traversals.
- if !rp.handleError(err) {
- vfs.putResolvingPath(rp)
- return err
- }
- }
-}
-
-// OpenAt returns a FileDescription providing access to the file at the given
-// path. A reference is taken on the returned FileDescription.
-func (vfs *VirtualFilesystem) OpenAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, opts *OpenOptions) (*FileDescription, error) {
- // Remove:
- //
- // - O_LARGEFILE, which we always report in FileDescription status flags
- // since only 64-bit architectures are supported at this time.
- //
- // - O_CLOEXEC, which affects file descriptors and therefore must be
- // handled outside of VFS.
- //
- // - Unknown flags.
- opts.Flags &= linux.O_ACCMODE | linux.O_CREAT | linux.O_EXCL | linux.O_NOCTTY | linux.O_TRUNC | linux.O_APPEND | linux.O_NONBLOCK | linux.O_DSYNC | linux.O_ASYNC | linux.O_DIRECT | linux.O_DIRECTORY | linux.O_NOFOLLOW | linux.O_NOATIME | linux.O_SYNC | linux.O_PATH | linux.O_TMPFILE
- // Linux's __O_SYNC (which we call linux.O_SYNC) implies O_DSYNC.
- if opts.Flags&linux.O_SYNC != 0 {
- opts.Flags |= linux.O_DSYNC
- }
- // Linux's __O_TMPFILE (which we call linux.O_TMPFILE) must be specified
- // with O_DIRECTORY and a writable access mode (to ensure that it fails on
- // filesystem implementations that do not support it).
- if opts.Flags&linux.O_TMPFILE != 0 {
- if opts.Flags&linux.O_DIRECTORY == 0 {
- return nil, syserror.EINVAL
- }
- if opts.Flags&linux.O_CREAT != 0 {
- return nil, syserror.EINVAL
- }
- if opts.Flags&linux.O_ACCMODE == linux.O_RDONLY {
- return nil, syserror.EINVAL
- }
- }
- // O_PATH causes most other flags to be ignored.
- if opts.Flags&linux.O_PATH != 0 {
- opts.Flags &= linux.O_DIRECTORY | linux.O_NOFOLLOW | linux.O_PATH
- }
- // "On Linux, the following bits are also honored in mode: [S_ISUID,
- // S_ISGID, S_ISVTX]" - open(2)
- opts.Mode &= 07777
-
- if opts.Flags&linux.O_NOFOLLOW != 0 {
- pop.FollowFinalSymlink = false
- }
- rp, err := vfs.getResolvingPath(creds, pop)
- if err != nil {
- return nil, err
- }
- if opts.Flags&linux.O_DIRECTORY != 0 {
- rp.mustBeDir = true
- rp.mustBeDirOrig = true
- }
- for {
- fd, err := rp.mount.fs.impl.OpenAt(ctx, rp, *opts)
- if err == nil {
- vfs.putResolvingPath(rp)
- return fd, nil
- }
- if !rp.handleError(err) {
- vfs.putResolvingPath(rp)
- return nil, err
- }
- }
-}
-
-// StatAt returns metadata for the file at the given path.
-func (vfs *VirtualFilesystem) StatAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, opts *StatOptions) (linux.Statx, error) {
- rp, err := vfs.getResolvingPath(creds, pop)
- if err != nil {
- return linux.Statx{}, err
- }
- for {
- stat, err := rp.mount.fs.impl.StatAt(ctx, rp, *opts)
- if err == nil {
- vfs.putResolvingPath(rp)
- return stat, nil
- }
- if !rp.handleError(err) {
- vfs.putResolvingPath(rp)
- return linux.Statx{}, err
- }
- }
-}
-
-// StatusFlags returns file description status flags.
-func (fd *FileDescription) StatusFlags(ctx context.Context) (uint32, error) {
- flags, err := fd.impl.StatusFlags(ctx)
- flags |= linux.O_LARGEFILE
- return flags, err
-}
-
-// SetStatusFlags sets file description status flags.
-func (fd *FileDescription) SetStatusFlags(ctx context.Context, flags uint32) error {
- return fd.impl.SetStatusFlags(ctx, flags)
-}
-
-// TODO:
-//
-// - VFS.SyncAllFilesystems() for sync(2)
-//
-// - Something for syncfs(2)
-//
-// - VFS.LinkAt()
-//
-// - VFS.ReadlinkAt()
-//
-// - VFS.RenameAt()
-//
-// - VFS.RmdirAt()
-//
-// - VFS.SetStatAt()
-//
-// - VFS.StatFSAt()
-//
-// - VFS.SymlinkAt()
-//
-// - VFS.UnlinkAt()
-//
-// - FileDescription.(almost everything)