Correctly set the test VFS environment variable.

Also fix test bugs uncovered now that they aren't silently skipped on
VFS2.

Updates #1487.

PiperOrigin-RevId: 316415807

test/runner/runner.go

@@ -352,11 +352,15 @@ func runTestCaseRunsc(testBin string, tc gtest.TestCase, t *testing.T) {
 
 	// Set environment variables that indicate we are running in gVisor with
 	// the given platform, network, and filesystem stack.
-	// TODO(gvisor.dev/issue/1487): Update this when the runner supports VFS2.
 	platformVar := "TEST_ON_GVISOR"
 	networkVar := "GVISOR_NETWORK"
+	env := append(os.Environ(), platformVar+"="+*platform, networkVar+"="+*network)
 	vfsVar := "GVISOR_VFS"
-	env := append(os.Environ(), platformVar+"="+*platform, networkVar+"="+*network, vfsVar+"=VFS1")
+	if *vfs2 {
+		env = append(env, vfsVar+"=VFS2")
+	} else {
+		env = append(env, vfsVar+"=VFS1")
+	}
 
 	// Remove env variables that cause the gunit binary to write output
 	// files, since they will stomp on eachother, and on the output files

test/syscalls/BUILD

@@ -68,6 +68,11 @@ syscall_test(
     vfs2 = "True",
 )
 
+syscall_test(
+    test = "//test/syscalls/linux:socket_capability_test",
+    vfs2 = "True",
+)
+
 syscall_test(
     size = "large",
     shard_count = 50,

test/syscalls/linux/BUILD

@@ -363,9 +363,24 @@ cc_binary(
     linkstatic = 1,
     deps = [
         ":socket_test_util",
+        gtest,
+        "//test/util:file_descriptor",
+        "//test/util:temp_umask",
+        "//test/util:test_main",
+        "//test/util:test_util",
+    ],
+)
+
+cc_binary(
+    name = "socket_capability_test",
+    testonly = 1,
+    srcs = ["socket_capability.cc"],
+    linkstatic = 1,
+    deps = [
+        ":socket_test_util",
+        "//test/util:capability_util",
         "//test/util:file_descriptor",
         gtest,
-        "//test/util:temp_umask",
         "//test/util:test_main",
         "//test/util:test_util",
     ],

test/syscalls/linux/socket.cc

@@ -86,37 +86,12 @@ TEST(SocketTest, UnixSocketStat) {
   EXPECT_EQ(statbuf.st_mode, S_IFSOCK | sock_perm & ~mask);
 
   // Timestamps should be equal and non-zero.
-  EXPECT_NE(statbuf.st_atime, 0);
-  EXPECT_EQ(statbuf.st_atime, statbuf.st_mtime);
-  EXPECT_EQ(statbuf.st_atime, statbuf.st_ctime);
-}
-
-TEST(SocketTest, UnixConnectNeedsWritePerm) {
-  SKIP_IF(IsRunningWithVFS1());
-
-  FileDescriptor bound =
-      ASSERT_NO_ERRNO_AND_VALUE(Socket(AF_UNIX, SOCK_STREAM, PF_UNIX));
-
-  struct sockaddr_un addr =
-      ASSERT_NO_ERRNO_AND_VALUE(UniqueUnixAddr(/*abstract=*/false, AF_UNIX));
-  ASSERT_THAT(bind(bound.get(), reinterpret_cast<struct sockaddr*>(&addr),
-                   sizeof(addr)),
-              SyscallSucceeds());
-  ASSERT_THAT(listen(bound.get(), 1), SyscallSucceeds());
-
-  // Connect should fail without write perms.
-  ASSERT_THAT(chmod(addr.sun_path, 0500), SyscallSucceeds());
-  FileDescriptor client =
-      ASSERT_NO_ERRNO_AND_VALUE(Socket(AF_UNIX, SOCK_STREAM, PF_UNIX));
-  EXPECT_THAT(connect(client.get(), reinterpret_cast<struct sockaddr*>(&addr),
-                      sizeof(addr)),
-              SyscallFailsWithErrno(EACCES));
-
-  // Connect should succeed with write perms.
-  ASSERT_THAT(chmod(addr.sun_path, 0200), SyscallSucceeds());
-  EXPECT_THAT(connect(client.get(), reinterpret_cast<struct sockaddr*>(&addr),
-                      sizeof(addr)),
-              SyscallSucceeds());
+  // TODO(b/158882152): Sockets currently don't implement timestamps.
+  if (!IsRunningOnGvisor()) {
+    EXPECT_NE(statbuf.st_atime, 0);
+    EXPECT_EQ(statbuf.st_atime, statbuf.st_mtime);
+    EXPECT_EQ(statbuf.st_atime, statbuf.st_ctime);
+  }
 }
 
 using SocketOpenTest = ::testing::TestWithParam<int>;

test/syscalls/linux/socket_capability.cc

@@ -0,0 +1,61 @@
+// Copyright 2018 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.
+
+// Subset of socket tests that need Linux-specific headers (compared to POSIX
+// headers).
+
+#include "gtest/gtest.h"
+#include "test/syscalls/linux/socket_test_util.h"
+#include "test/util/capability_util.h"
+#include "test/util/file_descriptor.h"
+#include "test/util/test_util.h"
+
+namespace gvisor {
+namespace testing {
+
+TEST(SocketTest, UnixConnectNeedsWritePerm) {
+  SKIP_IF(IsRunningWithVFS1());
+
+  FileDescriptor bound =
+      ASSERT_NO_ERRNO_AND_VALUE(Socket(AF_UNIX, SOCK_STREAM, PF_UNIX));
+
+  struct sockaddr_un addr =
+      ASSERT_NO_ERRNO_AND_VALUE(UniqueUnixAddr(/*abstract=*/false, AF_UNIX));
+  ASSERT_THAT(bind(bound.get(), reinterpret_cast<struct sockaddr*>(&addr),
+                   sizeof(addr)),
+              SyscallSucceeds());
+  ASSERT_THAT(listen(bound.get(), 1), SyscallSucceeds());
+
+  // Drop capabilites that allow us to override permision checks. Otherwise if
+  // the test is run as root, the connect below will bypass permission checks
+  // and succeed unexpectedly.
+  ASSERT_NO_ERRNO(SetCapability(CAP_DAC_OVERRIDE, false));
+
+  // Connect should fail without write perms.
+  ASSERT_THAT(chmod(addr.sun_path, 0500), SyscallSucceeds());
+  FileDescriptor client =
+      ASSERT_NO_ERRNO_AND_VALUE(Socket(AF_UNIX, SOCK_STREAM, PF_UNIX));
+  ASSERT_THAT(connect(client.get(), reinterpret_cast<struct sockaddr*>(&addr),
+                      sizeof(addr)),
+              SyscallFailsWithErrno(EACCES));
+
+  // Connect should succeed with write perms.
+  ASSERT_THAT(chmod(addr.sun_path, 0200), SyscallSucceeds());
+  EXPECT_THAT(connect(client.get(), reinterpret_cast<struct sockaddr*>(&addr),
+                      sizeof(addr)),
+              SyscallSucceeds());
+}
+
+}  // namespace testing
+}  // namespace gvisor