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-rw-r--r--pkg/sentry/fsimpl/mqfs/BUILD6
-rw-r--r--pkg/sentry/fsimpl/mqfs/queue.go145
-rw-r--r--pkg/sentry/fsimpl/mqfs/root.go (renamed from pkg/sentry/fsimpl/mqfs/inodes.go)2
3 files changed, 150 insertions, 3 deletions
diff --git a/pkg/sentry/fsimpl/mqfs/BUILD b/pkg/sentry/fsimpl/mqfs/BUILD
index afe1f3cd5..6b22ffabd 100644
--- a/pkg/sentry/fsimpl/mqfs/BUILD
+++ b/pkg/sentry/fsimpl/mqfs/BUILD
@@ -18,7 +18,8 @@ go_library(
name = "mqfs",
srcs = [
"mqfs.go",
- "inodes.go",
+ "root.go",
+ "queue.go",
"root_inode_refs.go",
],
visibility = ["//pkg/sentry:internal"],
@@ -29,6 +30,9 @@ go_library(
"//pkg/refsvfs2",
"//pkg/sentry/fsimpl/kernfs",
"//pkg/sentry/kernel/auth",
+ "//pkg/sentry/kernel/mq",
"//pkg/sentry/vfs",
+ "//pkg/usermem",
+ "//pkg/waiter",
],
)
diff --git a/pkg/sentry/fsimpl/mqfs/queue.go b/pkg/sentry/fsimpl/mqfs/queue.go
new file mode 100644
index 000000000..a8e9bc722
--- /dev/null
+++ b/pkg/sentry/fsimpl/mqfs/queue.go
@@ -0,0 +1,145 @@
+// Copyright 2021 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 mqfs
+
+import (
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/context"
+ "gvisor.dev/gvisor/pkg/errors/linuxerr"
+ "gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs"
+ "gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+ "gvisor.dev/gvisor/pkg/sentry/kernel/mq"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/usermem"
+ "gvisor.dev/gvisor/pkg/waiter"
+)
+
+// queueInode represents an inode for a message queue (/dev/mqueue/[name]).
+//
+// +stateify savable
+type queueInode struct {
+ kernfs.DynamicBytesFile
+
+ // queue is the message queue backing this inode.
+ queue *mq.Queue
+}
+
+var _ kernfs.Inode = (*queueInode)(nil)
+
+// newQueueInode returns a new, initialized queueInode.
+func (fs *filesystem) newQueueInode(ctx context.Context, creds *auth.Credentials, q *mq.Queue, perm linux.FileMode) kernfs.Inode {
+ inode := &queueInode{queue: q}
+ inode.Init(ctx, creds, linux.UNNAMED_MAJOR, fs.devMinor, fs.NextIno(), q, perm)
+ return inode
+}
+
+// Keep implements kernfs.Inode.Keep.
+func (q *queueInode) Keep() bool {
+ // Return true so that the fs keeps newly created dentries. This is done
+ // because inodes returned by root.Lookup are not temporary, they exist
+ // in the fs, and refer to message queues.
+ return true
+}
+
+// queueFD implements vfs.FileDescriptionImpl for FD backed by a POSIX message
+// queue. It's mostly similar to DynamicBytesFD, but implements more operations.
+//
+// +stateify savable
+type queueFD struct {
+ vfs.FileDescriptionDefaultImpl
+ vfs.DynamicBytesFileDescriptionImpl
+ vfs.LockFD
+
+ vfsfd vfs.FileDescription
+ inode kernfs.Inode
+
+ // queue is the queue backing this fd.
+ queue *mq.Queue
+}
+
+// Init initializes a queueFD. Mostly copied from DynamicBytesFD.Init, but uses
+// the queueFD as FileDescriptionImpl.
+func (fd *queueFD) Init(m *vfs.Mount, d *kernfs.Dentry, data vfs.DynamicBytesSource, locks *vfs.FileLocks, flags uint32) error {
+ fd.LockFD.Init(locks)
+ if err := fd.vfsfd.Init(fd, flags, m, d.VFSDentry(), &vfs.FileDescriptionOptions{}); err != nil {
+ return err
+ }
+ fd.inode = d.Inode()
+ fd.SetDataSource(data)
+ return nil
+}
+
+// Seek implements vfs.FileDescriptionImpl.Seek.
+func (fd *queueFD) Seek(ctx context.Context, offset int64, whence int32) (int64, error) {
+ return fd.DynamicBytesFileDescriptionImpl.Seek(ctx, offset, whence)
+}
+
+// Read implements vfs.FileDescriptionImpl.Read.
+func (fd *queueFD) Read(ctx context.Context, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) {
+ return fd.DynamicBytesFileDescriptionImpl.Read(ctx, dst, opts)
+}
+
+// PRead implements vfs.FileDescriptionImpl.PRead.
+func (fd *queueFD) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) {
+ return fd.DynamicBytesFileDescriptionImpl.PRead(ctx, dst, offset, opts)
+}
+
+// Write implements vfs.FileDescriptionImpl.Write.
+func (fd *queueFD) Write(ctx context.Context, src usermem.IOSequence, opts vfs.WriteOptions) (int64, error) {
+ return fd.DynamicBytesFileDescriptionImpl.Write(ctx, src, opts)
+}
+
+// PWrite implements vfs.FileDescriptionImpl.PWrite.
+func (fd *queueFD) PWrite(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) {
+ return fd.DynamicBytesFileDescriptionImpl.PWrite(ctx, src, offset, opts)
+}
+
+// Release implements vfs.FileDescriptionImpl.Release.
+func (fd *queueFD) Release(context.Context) {}
+
+// Stat implements vfs.FileDescriptionImpl.Stat.
+func (fd *queueFD) Stat(ctx context.Context, opts vfs.StatOptions) (linux.Statx, error) {
+ fs := fd.vfsfd.VirtualDentry().Mount().Filesystem()
+ return fd.inode.Stat(ctx, fs, opts)
+}
+
+// SetStat implements vfs.FileDescriptionImpl.SetStat.
+func (fd *queueFD) SetStat(context.Context, vfs.SetStatOptions) error {
+ // DynamicBytesFiles are immutable.
+ return linuxerr.EPERM
+}
+
+// OnClose implements FileDescriptionImpl.OnClose similar to
+// ipc/mqueue.c::mqueue_flush_file.
+func (fd *queueFD) OnClose(ctx context.Context) error {
+ fd.queue.Flush(ctx)
+ return nil
+}
+
+// Readiness implements waiter.Waitable.Readiness similar to
+// ipc/mqueue.c::mqueue_poll_file.
+func (fd *queueFD) Readiness(mask waiter.EventMask) waiter.EventMask {
+ return fd.queue.Readiness(mask)
+}
+
+// EventRegister implements Waitable.EventRegister.
+func (fd *queueFD) EventRegister(e *waiter.Entry, mask waiter.EventMask) {
+ fd.queue.EventRegister(e, mask)
+}
+
+// EventUnregister implements Waitable.EventUnregister.
+func (fd *queueFD) EventUnregister(e *waiter.Entry) {
+ fd.queue.EventUnregister(e)
+}
diff --git a/pkg/sentry/fsimpl/mqfs/inodes.go b/pkg/sentry/fsimpl/mqfs/root.go
index 702db59ee..37b5749fb 100644
--- a/pkg/sentry/fsimpl/mqfs/inodes.go
+++ b/pkg/sentry/fsimpl/mqfs/root.go
@@ -15,8 +15,6 @@
package mqfs
import (
- "bytes"
-
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/context"
"gvisor.dev/gvisor/pkg/errors/linuxerr"