diff options
Diffstat (limited to 'pkg/sentry/fsimpl/gofer')
-rw-r--r-- | pkg/sentry/fsimpl/gofer/filesystem.go | 62 | ||||
-rw-r--r-- | pkg/sentry/fsimpl/gofer/gofer.go | 23 | ||||
-rw-r--r-- | pkg/sentry/fsimpl/gofer/special_file.go | 28 |
3 files changed, 84 insertions, 29 deletions
diff --git a/pkg/sentry/fsimpl/gofer/filesystem.go b/pkg/sentry/fsimpl/gofer/filesystem.go index 4a32821bd..7f2181216 100644 --- a/pkg/sentry/fsimpl/gofer/filesystem.go +++ b/pkg/sentry/fsimpl/gofer/filesystem.go @@ -21,6 +21,8 @@ import ( "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/fspath" "gvisor.dev/gvisor/pkg/p9" + "gvisor.dev/gvisor/pkg/sentry/fsimpl/host" + "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/sentry/kernel/pipe" "gvisor.dev/gvisor/pkg/sentry/socket/unix/transport" @@ -835,6 +837,9 @@ func (d *dentry) openLocked(ctx context.Context, rp *vfs.ResolvingPath, opts *vf if d.isSynthetic() { return nil, syserror.ENXIO } + if d.fs.iopts.OpenSocketsByConnecting { + return d.connectSocketLocked(ctx, opts) + } case linux.S_IFIFO: if d.isSynthetic() { return d.pipe.Open(ctx, mnt, &d.vfsd, opts.Flags) @@ -843,10 +848,28 @@ func (d *dentry) openLocked(ctx context.Context, rp *vfs.ResolvingPath, opts *vf return d.openSpecialFileLocked(ctx, mnt, opts) } +func (d *dentry) connectSocketLocked(ctx context.Context, opts *vfs.OpenOptions) (*vfs.FileDescription, error) { + if opts.Flags&linux.O_DIRECT != 0 { + return nil, syserror.EINVAL + } + fdObj, err := d.file.connect(ctx, p9.AnonymousSocket) + if err != nil { + return nil, err + } + fd, err := host.NewFD(ctx, kernel.KernelFromContext(ctx).HostMount(), fdObj.FD(), &host.NewFDOptions{ + HaveFlags: true, + Flags: opts.Flags, + }) + if err != nil { + fdObj.Close() + return nil, err + } + fdObj.Release() + return fd, nil +} + func (d *dentry) openSpecialFileLocked(ctx context.Context, mnt *vfs.Mount, opts *vfs.OpenOptions) (*vfs.FileDescription, error) { ats := vfs.AccessTypesForOpenFlags(opts) - // Treat as a special file. This is done for non-synthetic pipes as well as - // regular files when d.fs.opts.regularFilesUseSpecialFileFD is true. if opts.Flags&linux.O_DIRECT != 0 { return nil, syserror.EINVAL } @@ -854,10 +877,15 @@ func (d *dentry) openSpecialFileLocked(ctx context.Context, mnt *vfs.Mount, opts if err != nil { return nil, err } + seekable := d.fileType() == linux.S_IFREG fd := &specialFileFD{ - handle: h, + handle: h, + seekable: seekable, } - if err := fd.vfsfd.Init(fd, opts.Flags, mnt, &d.vfsd, &vfs.FileDescriptionOptions{}); err != nil { + if err := fd.vfsfd.Init(fd, opts.Flags, mnt, &d.vfsd, &vfs.FileDescriptionOptions{ + DenyPRead: !seekable, + DenyPWrite: !seekable, + }); err != nil { h.close(ctx) return nil, err } @@ -888,7 +916,11 @@ func (d *dentry) createAndOpenChildLocked(ctx context.Context, rp *vfs.Resolving } creds := rp.Credentials() name := rp.Component() - fdobj, openFile, createQID, _, err := dirfile.create(ctx, name, (p9.OpenFlags)(opts.Flags), (p9.FileMode)(opts.Mode), (p9.UID)(creds.EffectiveKUID), (p9.GID)(creds.EffectiveKGID)) + // Filter file creation flags and O_LARGEFILE out; the create RPC already + // has the semantics of O_CREAT|O_EXCL, while some servers will choke on + // O_LARGEFILE. + createFlags := p9.OpenFlags(opts.Flags &^ (linux.O_CREAT | linux.O_EXCL | linux.O_NOCTTY | linux.O_TRUNC | linux.O_LARGEFILE)) + fdobj, openFile, createQID, _, err := dirfile.create(ctx, name, createFlags, (p9.FileMode)(opts.Mode), (p9.UID)(creds.EffectiveKUID), (p9.GID)(creds.EffectiveKGID)) if err != nil { dirfile.close(ctx) return nil, err @@ -896,7 +928,7 @@ func (d *dentry) createAndOpenChildLocked(ctx context.Context, rp *vfs.Resolving // Then we need to walk to the file we just created to get a non-open fid // representing it, and to get its metadata. This must use d.file since, as // explained above, dirfile was invalidated by dirfile.Create(). - walkQID, nonOpenFile, attrMask, attr, err := d.file.walkGetAttrOne(ctx, name) + _, nonOpenFile, attrMask, attr, err := d.file.walkGetAttrOne(ctx, name) if err != nil { openFile.close(ctx) if fdobj != nil { @@ -904,17 +936,6 @@ func (d *dentry) createAndOpenChildLocked(ctx context.Context, rp *vfs.Resolving } return nil, err } - // Sanity-check that we walked to the file we created. - if createQID.Path != walkQID.Path { - // Probably due to concurrent remote filesystem mutation? - ctx.Warningf("gofer.dentry.createAndOpenChildLocked: created file has QID %v before walk, QID %v after (interop=%v)", createQID, walkQID, d.fs.opts.interop) - nonOpenFile.close(ctx) - openFile.close(ctx) - if fdobj != nil { - fdobj.Close() - } - return nil, syserror.EAGAIN - } // Construct the new dentry. child, err := d.fs.newDentry(ctx, nonOpenFile, createQID, attrMask, &attr) @@ -960,16 +981,21 @@ func (d *dentry) createAndOpenChildLocked(ctx context.Context, rp *vfs.Resolving } childVFSFD = &fd.vfsfd } else { + seekable := child.fileType() == linux.S_IFREG fd := &specialFileFD{ handle: handle{ file: openFile, fd: -1, }, + seekable: seekable, } if fdobj != nil { fd.handle.fd = int32(fdobj.Release()) } - if err := fd.vfsfd.Init(fd, opts.Flags, mnt, &child.vfsd, &vfs.FileDescriptionOptions{}); err != nil { + if err := fd.vfsfd.Init(fd, opts.Flags, mnt, &child.vfsd, &vfs.FileDescriptionOptions{ + DenyPRead: !seekable, + DenyPWrite: !seekable, + }); err != nil { fd.handle.close(ctx) return nil, err } diff --git a/pkg/sentry/fsimpl/gofer/gofer.go b/pkg/sentry/fsimpl/gofer/gofer.go index 9ab8fdc65..1da8d5d82 100644 --- a/pkg/sentry/fsimpl/gofer/gofer.go +++ b/pkg/sentry/fsimpl/gofer/gofer.go @@ -81,6 +81,9 @@ type filesystem struct { // clock is a realtime clock used to set timestamps in file operations. clock ktime.Clock + // devMinor is the filesystem's minor device number. devMinor is immutable. + devMinor uint32 + // uid and gid are the effective KUID and KGID of the filesystem's creator, // and are used as the owner and group for files that don't specify one. // uid and gid are immutable. @@ -218,6 +221,10 @@ type InternalFilesystemOptions struct { // which servers can handle only a single client and report failure if that // client disconnects. LeakConnection bool + + // If OpenSocketsByConnecting is true, silently translate attempts to open + // files identifying as sockets to connect RPCs. + OpenSocketsByConnecting bool } // Name implements vfs.FilesystemType.Name. @@ -399,14 +406,21 @@ func (fstype FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt } // Construct the filesystem object. + devMinor, err := vfsObj.GetAnonBlockDevMinor() + if err != nil { + attachFile.close(ctx) + client.Close() + return nil, nil, err + } fs := &filesystem{ mfp: mfp, opts: fsopts, iopts: iopts, - uid: creds.EffectiveKUID, - gid: creds.EffectiveKGID, client: client, clock: ktime.RealtimeClockFromContext(ctx), + devMinor: devMinor, + uid: creds.EffectiveKUID, + gid: creds.EffectiveKGID, syncableDentries: make(map[*dentry]struct{}), specialFileFDs: make(map[*specialFileFD]struct{}), } @@ -464,6 +478,8 @@ func (fs *filesystem) Release() { // Close the connection to the server. This implicitly clunks all fids. fs.client.Close() } + + fs.vfsfs.VirtualFilesystem().PutAnonBlockDevMinor(fs.devMinor) } // dentry implements vfs.DentryImpl. @@ -796,7 +812,8 @@ func (d *dentry) statTo(stat *linux.Statx) { stat.Btime = statxTimestampFromDentry(atomic.LoadInt64(&d.btime)) stat.Ctime = statxTimestampFromDentry(atomic.LoadInt64(&d.ctime)) stat.Mtime = statxTimestampFromDentry(atomic.LoadInt64(&d.mtime)) - // TODO(gvisor.dev/issue/1198): device number + stat.DevMajor = linux.UNNAMED_MAJOR + stat.DevMinor = d.fs.devMinor } func (d *dentry) setStat(ctx context.Context, creds *auth.Credentials, stat *linux.Statx, mnt *vfs.Mount) error { diff --git a/pkg/sentry/fsimpl/gofer/special_file.go b/pkg/sentry/fsimpl/gofer/special_file.go index 507e0e276..a464e6a94 100644 --- a/pkg/sentry/fsimpl/gofer/special_file.go +++ b/pkg/sentry/fsimpl/gofer/special_file.go @@ -33,13 +33,14 @@ import ( type specialFileFD struct { fileDescription - // handle is immutable. + // handle is used for file I/O. handle is immutable. handle handle - // off is the file offset. off is protected by mu. (POSIX 2.9.7 only - // requires operations using the file offset to be atomic for regular files - // and symlinks; however, since specialFileFD may be used for regular - // files, we apply this atomicity unconditionally.) + // seekable is true if this file description represents a file for which + // file offset is significant, i.e. a regular file. seekable is immutable. + seekable bool + + // If seekable is true, off is the file offset. off is protected by mu. mu sync.Mutex off int64 } @@ -63,7 +64,7 @@ func (fd *specialFileFD) OnClose(ctx context.Context) error { // PRead implements vfs.FileDescriptionImpl.PRead. func (fd *specialFileFD) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) { - if offset < 0 { + if fd.seekable && offset < 0 { return 0, syserror.EINVAL } if opts.Flags != 0 { @@ -91,6 +92,10 @@ func (fd *specialFileFD) PRead(ctx context.Context, dst usermem.IOSequence, offs // Read implements vfs.FileDescriptionImpl.Read. func (fd *specialFileFD) Read(ctx context.Context, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) { + if !fd.seekable { + return fd.PRead(ctx, dst, -1, opts) + } + fd.mu.Lock() n, err := fd.PRead(ctx, dst, fd.off, opts) fd.off += n @@ -100,14 +105,14 @@ func (fd *specialFileFD) Read(ctx context.Context, dst usermem.IOSequence, opts // PWrite implements vfs.FileDescriptionImpl.PWrite. func (fd *specialFileFD) PWrite(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) { - if offset < 0 { + if fd.seekable && offset < 0 { return 0, syserror.EINVAL } if opts.Flags != 0 { return 0, syserror.EOPNOTSUPP } - if fd.dentry().fileType() == linux.S_IFREG { + if fd.seekable { limit, err := vfs.CheckLimit(ctx, offset, src.NumBytes()) if err != nil { return 0, err @@ -130,6 +135,10 @@ func (fd *specialFileFD) PWrite(ctx context.Context, src usermem.IOSequence, off // Write implements vfs.FileDescriptionImpl.Write. func (fd *specialFileFD) Write(ctx context.Context, src usermem.IOSequence, opts vfs.WriteOptions) (int64, error) { + if !fd.seekable { + return fd.PWrite(ctx, src, -1, opts) + } + fd.mu.Lock() n, err := fd.PWrite(ctx, src, fd.off, opts) fd.off += n @@ -139,6 +148,9 @@ func (fd *specialFileFD) Write(ctx context.Context, src usermem.IOSequence, opts // Seek implements vfs.FileDescriptionImpl.Seek. func (fd *specialFileFD) Seek(ctx context.Context, offset int64, whence int32) (int64, error) { + if !fd.seekable { + return 0, syserror.ESPIPE + } fd.mu.Lock() defer fd.mu.Unlock() switch whence { |