[PATCH v5 11/15] seltests/landlock: connect() with AF_UNSPEC tests

[Konstantin Meskhidze]

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 at huawei.com>
---

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

Changes since v4:
* Refactoring code with self->port, self->addr4 variables.
* Adds bind() hook check for with AF_UNSPEC family.

---
 tools/testing/selftests/landlock/net_test.c | 121 ++++++++++++++++++++
 1 file changed, 121 insertions(+)

diff --git a/tools/testing/selftests/landlock/net_test.c b/tools/testing/selftests/landlock/net_test.c
index cf914d311eb3..bf8e49466d1d 100644
--- a/tools/testing/selftests/landlock/net_test.c
+++ b/tools/testing/selftests/landlock/net_test.c
@@ -449,6 +449,7 @@ TEST_F_FORK(socket_test, connect_with_restrictions_ip6) {
 	int new_fd;
 	int sockfd_1, sockfd_2;
 	pid_t child_1, child_2;
+
 	int status;

 	struct landlock_ruleset_attr ruleset_attr = {
@@ -467,10 +468,12 @@ TEST_F_FORK(socket_test, connect_with_restrictions_ip6) {

 	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));
 	/* Allows connect and deny bind operations to the port[1] socket */
 	ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_NET_SERVICE,
@@ -480,6 +483,7 @@ TEST_F_FORK(socket_test, connect_with_restrictions_ip6) {
 	enforce_ruleset(_metadata, ruleset_fd);

 	/* Creates a server socket 1 */
+
 	sockfd_1 = create_socket(_metadata, true, false);
 	ASSERT_LE(0, sockfd_1);

@@ -556,4 +560,121 @@ TEST_F_FORK(socket_test, connect_with_restrictions_ip6) {
 	ASSERT_EQ(1, WIFEXITED(status));
 	ASSERT_EQ(EXIT_SUCCESS, WEXITSTATUS(status));
 }
+
+TEST_F_FORK(socket_test, connect_afunspec_no_restictions) {
+
+	int sockfd;
+	pid_t child;
+	int status;
+
+	/* Creates a server socket 1 */
+	sockfd = create_socket(_metadata, false, false);
+	ASSERT_LE(0, sockfd);
+
+	/* Binds the socket 1 to address with port[0] with AF_UNSPEC family */
+	self->addr4[0].sin_family = AF_UNSPEC;
+	ASSERT_EQ(0, bind(sockfd, (struct sockaddr *)&self->addr4[0], sizeof(self->addr4[0])));
+
+	/* Makes connection to socket with port[0] */
+	ASSERT_EQ(0, connect(sockfd, (struct sockaddr *)&self->addr4[0],
+						   sizeof(self->addr4[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_test, connect_afunspec_with_restictions) {
+
+	int sockfd;
+	pid_t child;
+	int status;
+
+	struct landlock_ruleset_attr ruleset_attr_1 = {
+		.handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP,
+	};
+	struct landlock_net_service_attr net_service_1 = {
+		.allowed_access = LANDLOCK_ACCESS_NET_BIND_TCP,
+
+		.port = self->port[0],
+	};
+
+	struct landlock_ruleset_attr ruleset_attr_2 = {
+		.handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP |
+				      LANDLOCK_ACCESS_NET_CONNECT_TCP,
+	};
+	struct landlock_net_service_attr net_service_2 = {
+		.allowed_access = LANDLOCK_ACCESS_NET_BIND_TCP |
+				  LANDLOCK_ACCESS_NET_CONNECT_TCP,
+
+		.port = self->port[0],
+	};
+
+	const int ruleset_fd_1 = landlock_create_ruleset(&ruleset_attr_1,
+					sizeof(ruleset_attr_1), 0);
+	ASSERT_LE(0, ruleset_fd_1);
+
+	/* Allows bind operations to the port[0] socket */
+	ASSERT_EQ(0, landlock_add_rule(ruleset_fd_1, LANDLOCK_RULE_NET_SERVICE,
+				       &net_service_1, 0));
+
+	/* Enforces the ruleset. */
+	enforce_ruleset(_metadata, ruleset_fd_1);
+
+	/* Creates a server socket 1 */
+	sockfd = create_socket(_metadata, false, false);
+	ASSERT_LE(0, sockfd);
+
+	/* Binds the socket 1 to address with port[0] with AF_UNSPEC family */
+	self->addr4[0].sin_family = AF_UNSPEC;
+	ASSERT_EQ(0, bind(sockfd, (struct sockaddr *)&self->addr4[0], sizeof(self->addr4[0])));
+
+	/* Makes connection to socket with port[0] */
+	ASSERT_EQ(0, connect(sockfd, (struct sockaddr *)&self->addr4[0],
+						   sizeof(self->addr4[0])));
+
+	const int ruleset_fd_2 = landlock_create_ruleset(&ruleset_attr_2,
+					sizeof(ruleset_attr_2), 0);
+	ASSERT_LE(0, ruleset_fd_2);
+
+	/* Allows connect and bind operations to the port[0] socket */
+	ASSERT_EQ(0, landlock_add_rule(ruleset_fd_2, LANDLOCK_RULE_NET_SERVICE,
+				       &net_service_2, 0));
+
+	/* Enforces the ruleset. */
+	enforce_ruleset(_metadata, ruleset_fd_2);
+
+	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