selftests/landlock: Extend access right tests to directories

Make sure that all filesystem access rights can be tied to directories.

Rename layout1.file_access_rights to layout1.file_and_dir_access_rights
to reflect this change.

Cc: Shuah Khan <shuah@kernel.org>
Link: https://lore.kernel.org/r/20220506160820.524344-6-mic@digikod.net
Cc: stable@vger.kernel.org
Signed-off-by: Mickaël Salaün <mic@digikod.net>

tools/testing/selftests/landlock/fs_test.c

@@ -418,11 +418,12 @@ TEST_F_FORK(layout1, inval)
 
 /* clang-format on */
 
-TEST_F_FORK(layout1, file_access_rights)
+TEST_F_FORK(layout1, file_and_dir_access_rights)
 {
 	__u64 access;
 	int err;
-	struct landlock_path_beneath_attr path_beneath = {};
+	struct landlock_path_beneath_attr path_beneath_file = {},
+					  path_beneath_dir = {};
 	struct landlock_ruleset_attr ruleset_attr = {
 		.handled_access_fs = ACCESS_ALL,
 	};
@@ -432,20 +433,33 @@ TEST_F_FORK(layout1, file_access_rights)
 	ASSERT_LE(0, ruleset_fd);
 
 	/* Tests access rights for files. */
-	path_beneath.parent_fd = open(file1_s1d2, O_PATH | O_CLOEXEC);
-	ASSERT_LE(0, path_beneath.parent_fd);
+	path_beneath_file.parent_fd = open(file1_s1d2, O_PATH | O_CLOEXEC);
+	ASSERT_LE(0, path_beneath_file.parent_fd);
+
+	/* Tests access rights for directories. */
+	path_beneath_dir.parent_fd =
+		open(dir_s1d2, O_PATH | O_DIRECTORY | O_CLOEXEC);
+	ASSERT_LE(0, path_beneath_dir.parent_fd);
+
 	for (access = 1; access <= ACCESS_LAST; access <<= 1) {
-		path_beneath.allowed_access = access;
+		path_beneath_dir.allowed_access = access;
+		ASSERT_EQ(0, landlock_add_rule(ruleset_fd,
+					       LANDLOCK_RULE_PATH_BENEATH,
+					       &path_beneath_dir, 0));
+
+		path_beneath_file.allowed_access = access;
 		err = landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
-					&path_beneath, 0);
-		if ((access | ACCESS_FILE) == ACCESS_FILE) {
+					&path_beneath_file, 0);
+		if (access & ACCESS_FILE) {
 			ASSERT_EQ(0, err);
 		} else {
 			ASSERT_EQ(-1, err);
 			ASSERT_EQ(EINVAL, errno);
 		}
 	}
-	ASSERT_EQ(0, close(path_beneath.parent_fd));
+	ASSERT_EQ(0, close(path_beneath_file.parent_fd));
+	ASSERT_EQ(0, close(path_beneath_dir.parent_fd));
+	ASSERT_EQ(0, close(ruleset_fd));
 }
 
 TEST_F_FORK(layout1, unknown_access_rights)