Add initial test cases for msgget(2).

Updates #135

test/syscalls/BUILD

@@ -330,6 +330,10 @@ syscall_test(
     test = "//test/syscalls/linux:mremap_test",
 )
 
+syscall_test(
+    test = "//test/syscalls/linux:msgqueue_test",
+)
+
 syscall_test(
     size = "medium",
     test = "//test/syscalls/linux:msync_test",

test/syscalls/linux/BUILD

@@ -4170,6 +4170,18 @@ cc_binary(
     ],
 )
 
+cc_binary(
+    name = "msgqueue_test",
+    testonly = 1,
+    srcs = ["msgqueue.cc"],
+    linkstatic = 1,
+    deps = [
+        "//test/util:temp_path",
+        "//test/util:test_main",
+        "//test/util:test_util",
+    ],
+)
+
 cc_binary(
     name = "fadvise64_test",
     testonly = 1,

test/syscalls/linux/msgqueue.cc

@@ -0,0 +1,96 @@
+// 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.
+
+#include <sys/ipc.h>
+#include <sys/msg.h>
+#include <sys/types.h>
+
+#include "test/util/temp_path.h"
+#include "test/util/test_util.h"
+
+namespace gvisor {
+namespace testing {
+namespace {
+
+// Queue is a RAII class used to automatically clean message queues.
+class Queue {
+ public:
+  explicit Queue(int id) : id_(id) {}
+
+  ~Queue() {
+    if (id_ >= 0) {
+      EXPECT_THAT(msgctl(id_, IPC_RMID, nullptr), SyscallSucceeds());
+    }
+  }
+
+  int release() {
+    int old = id_;
+    id_ = -1;
+    return old;
+  }
+
+  int get() { return id_; }
+
+ private:
+  int id_ = -1;
+};
+
+// Test simple creation and retrieval for msgget(2).
+TEST(MsgqueueTest, MsgGet) {
+  // Don't run test until syscall is implemented.
+  GTEST_SKIP();
+
+  const TempPath keyfile = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile());
+  const key_t key = ftok(keyfile.path().c_str(), 1);
+  ASSERT_THAT(key, SyscallSucceeds());
+
+  Queue queue(msgget(key, IPC_CREAT));
+  ASSERT_THAT(queue.get(), SyscallSucceeds());
+  EXPECT_THAT(msgget(key, 0), SyscallSucceedsWithValue(queue.get()));
+}
+
+// Test simple failure scenarios for msgget(2).
+TEST(MsgqueueTest, MsgGetFail) {
+  // Don't run test until syscall is implemented.
+  GTEST_SKIP();
+
+  const TempPath keyfile = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile());
+  const key_t key = ftok(keyfile.path().c_str(), 1);
+  ASSERT_THAT(key, SyscallSucceeds());
+
+  EXPECT_THAT(msgget(key, 0), SyscallFailsWithErrno(ENOENT));
+
+  Queue queue(msgget(key, IPC_CREAT));
+  ASSERT_THAT(queue.get(), SyscallSucceeds());
+
+  EXPECT_THAT(msgget(key, IPC_CREAT | IPC_EXCL), SyscallFailsWithErrno(EEXIST));
+}
+
+// Test using msgget(2) with IPC_PRIVATE option.
+TEST(MsgqueueTest, MsgGetIpcPrivate) {
+  // Don't run test until syscall is implemented.
+  GTEST_SKIP();
+
+  Queue queue1(msgget(IPC_PRIVATE, 0));
+  ASSERT_THAT(queue1.get(), SyscallSucceeds());
+
+  Queue queue2(msgget(IPC_PRIVATE, 0));
+  ASSERT_THAT(queue2.get(), SyscallSucceeds());
+
+  EXPECT_NE(queue1.get(), queue2.get());
+}
+
+}  // namespace
+}  // namespace testing
+}  // namespace gvisor