[RFC PATCH v4 12/15] seltest/landlock: connect() with AF_UNSPEC tests

[Konstantin Meskhidze <konstantin.meskhidze@huawei.com>]

Adds two selftests for connect() action with
AF_UNSPEC family flag.
The one is with no landlock restrictions
allows to disconnect already conneted socket
with connect(..., AF_UNSPEC, ...):
    - connect_afunspec_no_restictions;
The second one refuses landlocked process
to disconnect already connected socket:
    - connect_afunspec_with_restictions;

Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com>
---

Changes since v3:
* Add connect_afunspec_no_restictions test.
* Add connect_afunspec_with_restictions test.

---
 .../testing/selftests/landlock/network_test.c | 94 +++++++++++++++++++
 1 file changed, 94 insertions(+)

diff --git a/tools/testing/selftests/landlock/network_test.c b/tools/testing/selftests/landlock/network_test.c
index 20f2d94d6d85..6fce31cad368 100644
--- a/tools/testing/selftests/landlock/network_test.c
+++ b/tools/testing/selftests/landlock/network_test.c
@@ -312,4 +312,98 @@ TEST_F_FORK(socket, connect_with_restrictions) {
 	ASSERT_EQ(EXIT_SUCCESS, WEXITSTATUS(status));
 }

+TEST_F_FORK(socket, connect_afunspec_no_restictions) {
+
+	int sockfd;
+	pid_t child;
+	int status;
+
+	/* Creates a server socket 1 */
+	sockfd = create_socket(_metadata);
+	ASSERT_LE(0, sockfd);
+
+	/* Binds the socket 1 to address with port[0] */
+	ASSERT_EQ(0, bind(sockfd, (struct sockaddr *)&addr[0], sizeof(addr[0])));
+
+	/* Makes connection to socket with port[0] */
+	ASSERT_EQ(0, connect(sockfd, (struct sockaddr *)&addr[0],
+						   sizeof(addr[0])));
+
+	child = fork();
+	ASSERT_LE(0, child);
+	if (child == 0) {
+		struct sockaddr addr_unspec = {.sa_family = AF_UNSPEC};
+
+		/* Child tries to disconnect already connected socket */
+		ASSERT_EQ(0, connect(sockfd, (struct sockaddr *)&addr_unspec,
+						sizeof(addr_unspec)));
+		_exit(_metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE);
+		return;
+	}
+	/* Closes listening socket 1 for the parent*/
+	ASSERT_EQ(0, close(sockfd));
+
+	ASSERT_EQ(child, waitpid(child, &status, 0));
+	ASSERT_EQ(1, WIFEXITED(status));
+	ASSERT_EQ(EXIT_SUCCESS, WEXITSTATUS(status));
+}
+
+TEST_F_FORK(socket, connect_afunspec_with_restictions) {
+
+	int sockfd;
+	pid_t child;
+	int status;
+
+	struct landlock_ruleset_attr ruleset_attr = {
+		.handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP |
+				      LANDLOCK_ACCESS_NET_CONNECT_TCP,
+	};
+	struct landlock_net_service_attr net_service_1 = {
+		.allowed_access = LANDLOCK_ACCESS_NET_BIND_TCP |
+				  LANDLOCK_ACCESS_NET_CONNECT_TCP,
+
+		.port = port[0],
+	};
+
+	const int ruleset_fd = landlock_create_ruleset(&ruleset_attr,
+					sizeof(ruleset_attr), 0);
+	ASSERT_LE(0, ruleset_fd);
+
+	/* Allows connect and bind operations to the port[0] socket */
+	ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_NET_SERVICE,
+				       &net_service_1, 0));
+
+	/* Enforces the ruleset. */
+	enforce_ruleset(_metadata, ruleset_fd);
+
+	/* Creates a server socket 1 */
+	sockfd = create_socket(_metadata);
+	ASSERT_LE(0, sockfd);
+
+	/* Binds the socket 1 to address with port[0] */
+	ASSERT_EQ(0, bind(sockfd, (struct sockaddr *)&addr[0], sizeof(addr[0])));
+
+	/* Makes connection to socket with port[0] */
+	ASSERT_EQ(0, connect(sockfd, (struct sockaddr *)&addr[0],
+						   sizeof(addr[0])));
+
+	child = fork();
+	ASSERT_LE(0, child);
+	if (child == 0) {
+		struct sockaddr addr_unspec = {.sa_family = AF_UNSPEC};
+
+		/* Child tries to disconnect already connected socket */
+		ASSERT_EQ(-1, connect(sockfd, (struct sockaddr *)&addr_unspec,
+						sizeof(addr_unspec)));
+		ASSERT_EQ(EACCES, errno);
+		_exit(_metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE);
+		return;
+	}
+	/* Closes listening socket 1 for the parent*/
+	ASSERT_EQ(0, close(sockfd));
+
+	ASSERT_EQ(child, waitpid(child, &status, 0));
+	ASSERT_EQ(1, WIFEXITED(status));
+	ASSERT_EQ(EXIT_SUCCESS, WEXITSTATUS(status));
+}
 TEST_HARNESS_MAIN
--
2.25.1