1 files changed, 126 insertions, 0 deletions
diff --git a/pkg/sentry/fs/fsutil/handle.go b/pkg/sentry/fs/fsutil/handle.go
new file mode 100644
index 000000000..149c0f84a
--- /dev/null
+++ b/pkg/sentry/fs/fsutil/handle.go
@@ -0,0 +1,126 @@
+// Copyright 2018 Google Inc.
+//
+// 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 fsutil
+
+import (
+	"gvisor.googlesource.com/gvisor/pkg/sentry/context"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/fs"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/memmap"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/usermem"
+	"gvisor.googlesource.com/gvisor/pkg/syserror"
+	"gvisor.googlesource.com/gvisor/pkg/waiter"
+)
+
+// Handle implements FileOperations.
+//
+// FIXME: Remove Handle entirely in favor of individual fs.File
+// implementations using simple generic utilities.
+type Handle struct {
+	NoopRelease      `state:"nosave"`
+	NoIoctl          `state:"nosave"`
+	HandleOperations fs.HandleOperations
+
+	// dirCursor is the directory cursor.
+	dirCursor string
+}
+
+// NewHandle returns a File backed by the Dirent and FileFlags.
+func NewHandle(ctx context.Context, dirent *fs.Dirent, flags fs.FileFlags, hops fs.HandleOperations) *fs.File {
+	if !fs.IsPipe(dirent.Inode.StableAttr) && !fs.IsSocket(dirent.Inode.StableAttr) {
+		// Allow reading/writing at an arbitrary offset for non-pipes
+		// and non-sockets.
+		flags.Pread = true
+		flags.Pwrite = true
+	}
+
+	return fs.NewFile(ctx, dirent, flags, &Handle{HandleOperations: hops})
+}
+
+// Readiness implements waiter.Waitable.Readiness.
+func (h *Handle) Readiness(mask waiter.EventMask) waiter.EventMask {
+	return h.HandleOperations.Readiness(mask)
+}
+
+// EventRegister implements waiter.Waitable.EventRegister.
+func (h *Handle) EventRegister(e *waiter.Entry, mask waiter.EventMask) {
+	h.HandleOperations.EventRegister(e, mask)
+}
+
+// EventUnregister implements waiter.Waitable.EventUnregister.
+func (h *Handle) EventUnregister(e *waiter.Entry) {
+	h.HandleOperations.EventUnregister(e)
+}
+
+// Readdir implements FileOperations.Readdir.
+func (h *Handle) Readdir(ctx context.Context, file *fs.File, serializer fs.DentrySerializer) (int64, error) {
+	root := fs.RootFromContext(ctx)
+	defer root.DecRef()
+	dirCtx := &fs.DirCtx{
+		Serializer: serializer,
+		DirCursor:  &h.dirCursor,
+	}
+	n, err := fs.DirentReaddir(ctx, file.Dirent, h, root, dirCtx, file.Offset())
+	return n, err
+}
+
+// Seek implements FileOperations.Seek.
+func (h *Handle) Seek(ctx context.Context, file *fs.File, whence fs.SeekWhence, offset int64) (int64, error) {
+	return SeekWithDirCursor(ctx, file, whence, offset, &h.dirCursor)
+}
+
+// IterateDir implements DirIterator.IterateDir.
+func (h *Handle) IterateDir(ctx context.Context, dirCtx *fs.DirCtx, offset int) (int, error) {
+	return h.HandleOperations.DeprecatedReaddir(ctx, dirCtx, offset)
+}
+
+// Read implements FileOperations.Read.
+func (h *Handle) Read(ctx context.Context, file *fs.File, dst usermem.IOSequence, offset int64) (int64, error) {
+	return h.HandleOperations.DeprecatedPreadv(ctx, dst, offset)
+}
+
+// Write implements FileOperations.Write.
+func (h *Handle) Write(ctx context.Context, file *fs.File, src usermem.IOSequence, offset int64) (int64, error) {
+	return h.HandleOperations.DeprecatedPwritev(ctx, src, offset)
+}
+
+// Fsync implements FileOperations.Fsync.
+func (h *Handle) Fsync(ctx context.Context, file *fs.File, start int64, end int64, syncType fs.SyncType) error {
+	switch syncType {
+	case fs.SyncAll, fs.SyncData:
+		// Write out metadata.
+		if err := file.Dirent.Inode.WriteOut(ctx); err != nil {
+			return err
+		}
+		fallthrough
+	case fs.SyncBackingStorage:
+		// Use DeprecatedFsync to sync disks.
+		return h.HandleOperations.DeprecatedFsync()
+	}
+	panic("invalid sync type")
+}
+
+// Flush implements FileOperations.Flush.
+func (h *Handle) Flush(context.Context, *fs.File) error {
+	return h.HandleOperations.DeprecatedFlush()
+}
+
+// ConfigureMMap implements FileOperations.ConfigureMMap.
+func (h *Handle) ConfigureMMap(ctx context.Context, file *fs.File, opts *memmap.MMapOpts) error {
+	mappable := file.Dirent.Inode.Mappable()
+	if mappable == nil {
+		return syserror.ENODEV
+	}
+	return GenericConfigureMMap(file, mappable, opts)
+}