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

[Mickaël Salaün]

I guess these tests would also work with IPv6. You can then use the 
"alternative" tests I explained.

On 16/05/2022 17:20, Konstantin Meskhidze wrote:
> 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);
> +

Please no…


>   	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,
> +

ditto

>   				&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
>