[RFC PATCH v3 07/19] selftests/landlock: Test adding a rule for empty access

[Mikhail Ivanov]

Add test that validates behaviour of Landlock after rule with
empty access is added.

Signed-off-by: Mikhail Ivanov <ivanov.mikhail1 at huawei-partners.com>
---
Changes since v2:
* Renames protocol.inval into protocol.rule_with_empty_access.
* Replaces ASSERT_EQ with EXPECT_EQ for landlock_add_rule().
* Closes ruleset_fd.
* Refactors commit message and title.
* Minor fixes.

Changes since v1:
* Refactors commit message.
---
 .../testing/selftests/landlock/socket_test.c  | 33 +++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/tools/testing/selftests/landlock/socket_test.c b/tools/testing/selftests/landlock/socket_test.c
index d2fedfca7193..d323f649a183 100644
--- a/tools/testing/selftests/landlock/socket_test.c
+++ b/tools/testing/selftests/landlock/socket_test.c
@@ -384,4 +384,37 @@ TEST_F(protocol, rule_with_unhandled_access)
 	ASSERT_EQ(0, close(ruleset_fd));
 }
 
+TEST_F(protocol, rule_with_empty_access)
+{
+	const struct landlock_ruleset_attr ruleset_attr = {
+		.handled_access_socket = LANDLOCK_ACCESS_SOCKET_CREATE
+	};
+	struct landlock_socket_attr protocol_allowed = {
+		.allowed_access = LANDLOCK_ACCESS_SOCKET_CREATE,
+		.family = self->prot.family,
+		.type = self->prot.type,
+	};
+	struct landlock_socket_attr protocol_denied = {
+		.allowed_access = 0,
+		.family = self->prot.family,
+		.type = self->prot.type,
+	};
+	int ruleset_fd;
+
+	ruleset_fd =
+		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
+	ASSERT_LE(0, ruleset_fd);
+
+	/* Checks zero access value. */
+	EXPECT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_SOCKET,
+					&protocol_denied, 0));
+	EXPECT_EQ(ENOMSG, errno);
+
+	/* Adds with legitimate value. */
+	EXPECT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_SOCKET,
+				       &protocol_allowed, 0));
+
+	ASSERT_EQ(0, close(ruleset_fd));
+}
+
 TEST_HARNESS_MAIN
-- 
2.34.1