Add test that validates behaviour of Landlock after rule of
LANDLOCK_RULE_SOCKET type is added
  * with all possible access rights;
  * with unknown access rights;
  * with unhandled access rights;
  * with empty access.

Signed-off-by: Mikhail Ivanov <ivanov.mikhail1@huawei-partners.com>
---
Changes since v3:
* Squashes commits related to checking rule adding
* Removes "protocol" fixture dependency. Use single TCP protocol for
  testing instead.
* Fixes semantics of test "rule_with_unhandled_access".

Changes since v2:
* Replaces EXPECT_EQ with ASSERT_EQ for close().
* Refactors commit message and title.

Changes since v1:
* Formats code with clang-format.
* Refactors commit message.
---
 .../testing/selftests/landlock/socket_test.c  | 107 ++++++++++++++++++
 1 file changed, 107 insertions(+)

diff --git a/tools/testing/selftests/landlock/socket_test.c b/tools/testing/selftests/landlock/socket_test.c
index d5716149d03f..fcc0f92075a7 100644
--- a/tools/testing/selftests/landlock/socket_test.c
+++ b/tools/testing/selftests/landlock/socket_test.c
@@ -44,4 +44,111 @@ TEST_F(mini, ruleset_with_unknown_access)
 	}
 }
 
+TEST_F(mini, rule_with_supported_access)
+{
+	const struct landlock_ruleset_attr ruleset_attr = {
+		.handled_access_socket = ACCESS_ALL,
+	};
+	struct landlock_socket_attr protocol = {
+		.family = AF_INET,
+		.type = SOCK_STREAM,
+		.protocol = 0,
+	};
+	int ruleset_fd;
+	__u64 access;
+
+	ruleset_fd =
+		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
+	ASSERT_LE(0, ruleset_fd);
+
+	for (access = 1; access <= ACCESS_LAST; access <<= 1) {
+		protocol.allowed_access = access;
+		EXPECT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_SOCKET,
+					       &protocol, 0))
+		{
+			TH_LOG("Failed to add rule with access 0x%llx: %s",
+			       access, strerror(errno));
+		}
+	}
+	ASSERT_EQ(0, close(ruleset_fd));
+}
+
+TEST_F(mini, rule_with_unknown_access)
+{
+	const struct landlock_ruleset_attr ruleset_attr = {
+		.handled_access_socket = ACCESS_ALL,
+	};
+	struct landlock_socket_attr protocol = { .family = AF_INET,
+						 .type = SOCK_STREAM,
+						 .protocol = 0 };
+	int ruleset_fd;
+	__u64 access;
+
+	ruleset_fd =
+		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
+	ASSERT_LE(0, ruleset_fd);
+
+	for (access = 1ULL << 63; access != ACCESS_LAST; access >>= 1) {
+		protocol.allowed_access = access;
+		EXPECT_EQ(-1,
+			  landlock_add_rule(ruleset_fd, LANDLOCK_RULE_SOCKET,
+					    &protocol, 0));
+		EXPECT_EQ(EINVAL, errno);
+	}
+	ASSERT_EQ(0, close(ruleset_fd));
+}
+
+TEST_F(mini, rule_with_unhandled_access)
+{
+	/* Prepares ruleset that handles network access instead of socket access. */
+	const struct landlock_ruleset_attr ruleset_attr = {
+		.handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP,
+	};
+	struct landlock_socket_attr protocol = { .family = AF_UNIX,
+						 .type = SOCK_STREAM,
+						 .protocol = 0 };
+	int ruleset_fd;
+	__u64 access;
+
+	ruleset_fd =
+		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
+	ASSERT_LE(0, ruleset_fd);
+
+	for (access = ACCESS_LAST; access > 0; access <<= 1) {
+		int err;
+
+		protocol.allowed_access = access;
+		err = landlock_add_rule(ruleset_fd, LANDLOCK_RULE_SOCKET,
+					&protocol, 0);
+		EXPECT_EQ(-1, err);
+		EXPECT_EQ(EINVAL, errno);
+	}
+
+	ASSERT_EQ(0, close(ruleset_fd));
+}
+
+TEST_F(mini, rule_with_empty_access)
+{
+	const struct landlock_ruleset_attr ruleset_attr = {
+		.handled_access_socket = LANDLOCK_ACCESS_SOCKET_CREATE
+	};
+	const struct landlock_socket_attr protocol_denied = {
+		.allowed_access = 0,
+		.family = AF_UNIX,
+		.type = SOCK_STREAM,
+		.protocol = 0,
+	};
+	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);
+	ASSERT_EQ(0, close(ruleset_fd));
+}
+
 TEST_HARNESS_MAIN
-- 
2.34.1