[PATCH v6 13/17] seltests/landlock: adds AF_UNSPEC family test

[Konstantin Meskhidze]

Adds two selftests for connect() action with
AF_UNSPEC family flag.
The one is with no landlock restrictions
allows to disconnect already connected 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 v5:
* Formats code with clang-format-14.

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

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

---
 tools/testing/selftests/landlock/net_test.c | 113 ++++++++++++++++++++
 1 file changed, 113 insertions(+)

diff --git a/tools/testing/selftests/landlock/net_test.c b/tools/testing/selftests/landlock/net_test.c
index ce6fd51a922d..c5fe4284c38f 100644
--- a/tools/testing/selftests/landlock/net_test.c
+++ b/tools/testing/selftests/landlock/net_test.c
@@ -351,4 +351,117 @@ TEST_F(socket, connect_with_restrictions)
 	ASSERT_EQ(1, WIFEXITED(status));
 	ASSERT_EQ(EXIT_SUCCESS, WEXITSTATUS(status));
 }
+
+TEST_F(socket, connect_afunspec_no_restictions)
+{
+	int sockfd;
+	pid_t child;
+	int status;
+
+	/* Creates a server socket 1. */
+	sockfd = create_socket_variant(variant, SOCK_STREAM);
+	ASSERT_LE(0, sockfd);
+
+	/* Binds the socket 1 to address with port[0]. */
+	ASSERT_EQ(0, bind_variant(variant, sockfd, self, 0));
+
+	/* Makes connection to the socket with port[0]. */
+	ASSERT_EQ(0, connect_variant(variant, sockfd, self, 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(socket, 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_variant(variant, SOCK_STREAM);
+	ASSERT_LE(0, sockfd);
+
+	/* Binds the socket 1 to address with port[0]. */
+	ASSERT_EQ(0, bind_variant(variant, sockfd, self, 0));
+
+	/* Makes connection to socket with port[0]. */
+	ASSERT_EQ(0, connect_variant(variant, sockfd, self, 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