Implement stubs for mq_open(2) and mq_unlink(2).

Support mq_open and mq_unlink, and enable syscall tests.

Updates #136

4 files changed, 113 insertions, 14 deletions

diff --git a/pkg/sentry/syscalls/linux/vfs2/BUILD b/pkg/sentry/syscalls/linux/vfs2/BUILD
index 1e3bd2a50..4a03008f8 100644
--- a/pkg/sentry/syscalls/linux/vfs2/BUILD
+++ b/pkg/sentry/syscalls/linux/vfs2/BUILD
@@ -19,6 +19,7 @@ go_library(
         "memfd.go",
         "mmap.go",
         "mount.go",
+        "mq.go",
         "path.go",
         "pipe.go",
         "poll.go",
@@ -59,6 +60,7 @@ go_library(
         "//pkg/sentry/kernel",
         "//pkg/sentry/kernel/auth",
         "//pkg/sentry/kernel/fasync",
+        "//pkg/sentry/kernel/mq",
         "//pkg/sentry/kernel/pipe",
         "//pkg/sentry/kernel/time",
         "//pkg/sentry/limits",
diff --git a/pkg/sentry/syscalls/linux/vfs2/mq.go b/pkg/sentry/syscalls/linux/vfs2/mq.go
new file mode 100644
index 000000000..d5d81c6e2
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/mq.go
@@ -0,0 +1,98 @@
+// 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 vfs2
+
+import (
+	"gvisor.dev/gvisor/pkg/abi/linux"
+	"gvisor.dev/gvisor/pkg/sentry/arch"
+	"gvisor.dev/gvisor/pkg/sentry/kernel"
+	"gvisor.dev/gvisor/pkg/sentry/kernel/mq"
+)
+
+// MqOpen implements mq_open(2).
+func MqOpen(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+	nameAddr := args[0].Pointer()
+	flag := args[1].Int()
+	mode := args[2].ModeT()
+	attrAddr := args[3].Pointer()
+
+	name, err := t.CopyInString(nameAddr, mq.MaxName)
+	if err != nil {
+		return 0, nil, err
+	}
+
+	rOnly := flag&linux.O_RDONLY == linux.O_RDONLY
+	wOnly := flag&linux.O_WRONLY == linux.O_WRONLY
+	readWrite := flag&linux.O_RDWR == linux.O_RDWR
+
+	create := flag&linux.O_CREAT == linux.O_CREAT
+	exclusive := flag&linux.O_EXCL == linux.O_EXCL
+	block := flag&linux.O_NONBLOCK != linux.O_NONBLOCK
+
+	var attr linux.MqAttr
+	var attrPtr *linux.MqAttr
+	if attrAddr != 0 {
+		if _, err := attr.CopyIn(t, attrAddr); err != nil {
+			return 0, nil, err
+		}
+		attrPtr = &attr
+	}
+
+	opts := openOpts(name, rOnly, wOnly, readWrite, create, exclusive, block)
+
+	r := t.IPCNamespace().PosixQueues()
+	queue, err := r.FindOrCreate(t, opts, linux.FileMode(mode), attrPtr)
+	if err != nil {
+		return 0, nil, err
+	}
+
+	fd, err := t.NewFDFromVFS2(0, queue, kernel.FDFlags{
+		CloseOnExec: flag&linux.O_CLOEXEC != 0,
+	})
+	if err != nil {
+		return 0, nil, err
+	}
+	return uintptr(fd), nil, nil
+}
+
+// MqUnlink implements mq_unlink(2).
+func MqUnlink(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+	nameAddr := args[0].Pointer()
+	name, err := t.CopyInString(nameAddr, mq.MaxName)
+	if err != nil {
+		return 0, nil, err
+	}
+	return 0, nil, t.IPCNamespace().PosixQueues().Remove(t, name)
+}
+
+func openOpts(name string, rOnly, wOnly, readWrite, create, exclusive, block bool) mq.OpenOpts {
+	var access mq.AccessType
+	switch {
+	case readWrite:
+		access = mq.ReadWrite
+	case wOnly:
+		access = mq.WriteOnly
+	case rOnly:
+		access = mq.ReadOnly
+	}
+
+	return mq.OpenOpts{
+		Name:      name,
+		Access:    access,
+		Create:    create,
+		Exclusive: exclusive,
+		Block:     block,
+	}
+}
diff --git a/pkg/sentry/syscalls/linux/vfs2/vfs2.go b/pkg/sentry/syscalls/linux/vfs2/vfs2.go
index 0fc81e694..4eb15a7f2 100644
--- a/pkg/sentry/syscalls/linux/vfs2/vfs2.go
+++ b/pkg/sentry/syscalls/linux/vfs2/vfs2.go
@@ -112,6 +112,8 @@ func Override() {
 	s.Table[232] = syscalls.Supported("epoll_wait", EpollWait)
 	s.Table[233] = syscalls.Supported("epoll_ctl", EpollCtl)
 	s.Table[235] = syscalls.Supported("utimes", Utimes)
+	s.Table[240] = syscalls.Supported("mq_open", MqOpen)
+	s.Table[241] = syscalls.Supported("mq_unlink", MqUnlink)
 	s.Table[253] = syscalls.PartiallySupported("inotify_init", InotifyInit, "inotify events are only available inside the sandbox.", nil)
 	s.Table[254] = syscalls.PartiallySupported("inotify_add_watch", InotifyAddWatch, "inotify events are only available inside the sandbox.", nil)
 	s.Table[255] = syscalls.PartiallySupported("inotify_rm_watch", InotifyRmWatch, "inotify events are only available inside the sandbox.", nil)
@@ -241,6 +243,8 @@ func Override() {
 	s.Table[86] = syscalls.Supported("timerfd_settime", TimerfdSettime)
 	s.Table[87] = syscalls.Supported("timerfd_gettime", TimerfdGettime)
 	s.Table[88] = syscalls.Supported("utimensat", Utimensat)
+	s.Table[180] = syscalls.Supported("mq_open", MqOpen)
+	s.Table[181] = syscalls.Supported("mq_unlink", MqUnlink)
 	s.Table[198] = syscalls.Supported("socket", Socket)
 	s.Table[199] = syscalls.Supported("socketpair", SocketPair)
 	s.Table[200] = syscalls.Supported("bind", Bind)
@@ -271,6 +275,5 @@ func Override() {
 	s.Table[287] = syscalls.Supported("pwritev2", Pwritev2)
 	s.Table[291] = syscalls.Supported("statx", Statx)
 	s.Table[441] = syscalls.Supported("epoll_pwait2", EpollPwait2)
-
 	s.Init()
 }
diff --git a/test/syscalls/linux/mq.cc b/test/syscalls/linux/mq.cc
index 9a4a87dfe..b3cd6d1b9 100644
--- a/test/syscalls/linux/mq.cc
+++ b/test/syscalls/linux/mq.cc
@@ -121,14 +121,14 @@ PosixError MqClose(mqd_t fd) {
 
 // Test simple opening and closing of a message queue.
 TEST(MqTest, Open) {
-  GTEST_SKIP();
+  SKIP_IF(IsRunningWithVFS1());
   EXPECT_THAT(MqOpen(O_RDWR | O_CREAT | O_EXCL, 0777, nullptr),
               IsPosixErrorOkAndHolds(_));
 }
 
 // Test mq_open(2) after mq_unlink(2).
 TEST(MqTest, OpenAfterUnlink) {
-  GTEST_SKIP();
+  SKIP_IF(IsRunningWithVFS1());
 
   PosixQueue queue = ASSERT_NO_ERRNO_AND_VALUE(
       MqOpen(O_RDWR | O_CREAT | O_EXCL, 0777, nullptr));
@@ -140,7 +140,7 @@ TEST(MqTest, OpenAfterUnlink) {
 
 // Test using invalid args with mq_open.
 TEST(MqTest, OpenInvalidArgs) {
-  GTEST_SKIP();
+  SKIP_IF(IsRunningWithVFS1());
 
   // Name must start with a slash.
   EXPECT_THAT(MqOpen("test", O_RDWR), PosixErrorIs(EINVAL));
@@ -180,7 +180,7 @@ TEST(MqTest, OpenInvalidArgs) {
 
 // Test creating a queue that already exists.
 TEST(MqTest, CreateAlreadyExists) {
-  GTEST_SKIP();
+  SKIP_IF(IsRunningWithVFS1());
 
   PosixQueue queue = ASSERT_NO_ERRNO_AND_VALUE(
       MqOpen(O_RDWR | O_CREAT | O_EXCL, 0777, nullptr));
@@ -191,7 +191,7 @@ TEST(MqTest, CreateAlreadyExists) {
 
 // Test opening a queue that doesn't exists.
 TEST(MqTest, NoQueueExists) {
-  GTEST_SKIP();
+  SKIP_IF(IsRunningWithVFS1());
 
   // Choose a name to pass that's unlikely to exist if the test is run locally.
   EXPECT_THAT(MqOpen("/gvisor-mq-test-nonexistent-queue", O_RDWR),
@@ -236,8 +236,8 @@ TEST(MqTest, OpenWriteAccess) {
 
 // Test changing IPC namespace.
 TEST(MqTest, ChangeIpcNamespace) {
-  GTEST_SKIP();
-  SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_SYS_ADMIN)));
+  SKIP_IF(IsRunningWithVFS1() ||
+          !ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_SYS_ADMIN)));
 
   // When changing IPC namespaces, Linux doesn't invalidate or close the
   // previously opened file descriptions and allows operations to be performed
@@ -267,7 +267,6 @@ TEST(MqTest, ChangeIpcNamespace) {
 
 // Test mounting the mqueue filesystem.
 TEST(MqTest, Mount) {
-  GTEST_SKIP();
   SKIP_IF(IsRunningWithVFS1() ||
           !ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_SYS_ADMIN)));
 
@@ -280,7 +279,6 @@ TEST(MqTest, Mount) {
 
 // Test mounting the mqueue filesystem to several places.
 TEST(MqTest, MountSeveral) {
-  GTEST_SKIP();
   SKIP_IF(IsRunningWithVFS1() ||
           !ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_SYS_ADMIN)));
 
@@ -299,7 +297,6 @@ TEST(MqTest, MountSeveral) {
 
 // Test mounting mqueue and opening a queue as normal file.
 TEST(MqTest, OpenAsFile) {
-  GTEST_SKIP();
   SKIP_IF(IsRunningWithVFS1() ||
           !ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_SYS_ADMIN)));
 
@@ -328,7 +325,6 @@ TEST(MqTest, OpenAsFile) {
 
 // Test removing a queue using unlink(2).
 TEST(MqTest, UnlinkAsFile) {
-  GTEST_SKIP();
   SKIP_IF(IsRunningWithVFS1() ||
           !ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_SYS_ADMIN)));
 
@@ -349,7 +345,7 @@ TEST(MqTest, UnlinkAsFile) {
 
 // Test read(2) from an empty queue.
 TEST(MqTest, ReadEmpty) {
-  GTEST_SKIP();
+  SKIP_IF(IsRunningWithVFS1());
 
   PosixQueue queue = ASSERT_NO_ERRNO_AND_VALUE(
       MqOpen(O_RDWR | O_CREAT | O_EXCL, 0777, nullptr));
@@ -368,7 +364,7 @@ TEST(MqTest, ReadEmpty) {
 
 // Test poll(2) on an empty queue.
 TEST(MqTest, PollEmpty) {
-  GTEST_SKIP();
+  SKIP_IF(IsRunningWithVFS1());
 
   PosixQueue queue = ASSERT_NO_ERRNO_AND_VALUE(
       MqOpen(O_RDWR | O_CREAT | O_EXCL, 0777, nullptr));