On Wed, Sep 04, 2024 at 06:48:21PM +0800, Mikhail Ivanov wrote:
> Add test validating that socket creation with accept(2) is not restricted
> by Landlock.
>
> Signed-off-by: Mikhail Ivanov <ivanov.mikhail1@xxxxxxxxxxxxxxxxxxx>
> ---
> .../testing/selftests/landlock/socket_test.c | 71 +++++++++++++++++++
> 1 file changed, 71 insertions(+)
>
> diff --git a/tools/testing/selftests/landlock/socket_test.c b/tools/testing/selftests/landlock/socket_test.c
> index 2ab27196fa3d..052dbe0d1227 100644
> --- a/tools/testing/selftests/landlock/socket_test.c
> +++ b/tools/testing/selftests/landlock/socket_test.c
> @@ -939,4 +939,75 @@ TEST_F(socket_creation, sctp_peeloff)
> ASSERT_EQ(0, close(server_fd));
> }
>
> +TEST_F(socket_creation, accept)
> +{
> + int status;
> + pid_t child;
> + struct sockaddr_in addr;
> + int server_fd, client_fd;
> + char buf;
> + const struct landlock_ruleset_attr ruleset_attr = {
> + .handled_access_socket = LANDLOCK_ACCESS_SOCKET_CREATE,
> + };
> + struct landlock_socket_attr tcp_socket_create = {
^^^^^^
Could be const as well, just like the ruleset_attr?
(I probably overlooked this as well in some of the other tests.)
> + .allowed_access = LANDLOCK_ACCESS_SOCKET_CREATE,
> + .family = AF_INET,
> + .type = SOCK_STREAM,
> + };
> +
> + server_fd = socket(AF_INET, SOCK_STREAM | SOCK_CLOEXEC, 0);
> + ASSERT_LE(0, server_fd);
> +
> + addr.sin_family = AF_INET;
> + addr.sin_port = htons(loopback_port);
> + addr.sin_addr.s_addr = inet_addr(loopback_ipv4);
> +
> + ASSERT_EQ(0, bind(server_fd, &addr, sizeof(addr)));
> + ASSERT_EQ(0, listen(server_fd, backlog));
> +
> + child = fork();
> + ASSERT_LE(0, child);
> + if (child == 0) {
Nit:
I feel like the child code would benefit from a higher level comment,
like "Connects to the server once and exits." or such.
> + /* Closes listening socket for the child. */
> + ASSERT_EQ(0, close(server_fd));
> +
> + client_fd = socket(AF_INET, SOCK_STREAM | SOCK_CLOEXEC, 0);
> + ASSERT_LE(0, client_fd);
> +
> + ASSERT_EQ(0, connect(client_fd, &addr, sizeof(addr)));
> + EXPECT_EQ(1, write(client_fd, ".", 1));
> +
> + ASSERT_EQ(0, close(client_fd));
> + _exit(_metadata->exit_code);
> + return;
> + }
> +
> + if (self->sandboxed) {
> + int ruleset_fd = landlock_create_ruleset(
> + &ruleset_attr, sizeof(ruleset_attr), 0);
> + ASSERT_LE(0, ruleset_fd);
> + if (self->allowed) {
> + ASSERT_EQ(0, landlock_add_rule(ruleset_fd,
> + LANDLOCK_RULE_SOCKET,
> + &tcp_socket_create, 0));
> + }
> + enforce_ruleset(_metadata, ruleset_fd);
> + ASSERT_EQ(0, close(ruleset_fd));
> + }
> +
> + client_fd = accept(server_fd, NULL, 0);
> +
> + /* accept(2) should not be restricted by Landlock. */
> + EXPECT_LE(0, client_fd);
Should be an ASSERT, IMHO.
If this fails, client_fd will be -1,
and a lot of the stuff afterwards will fail as well.
> +
> + EXPECT_EQ(1, read(client_fd, &buf, 1));
> + EXPECT_EQ('.', buf);
I'm torn on whether the "." write and the check for it is very useful in this test.
It muddies the test's purpose a bit, and makes it harder to recognize the main use case.
Might make the test a bit simpler to drop it.
> +
> + ASSERT_EQ(child, waitpid(child, &status, 0));
> + ASSERT_EQ(1, WIFEXITED(status));
> + ASSERT_EQ(EXIT_SUCCESS, WEXITSTATUS(status));
> +
> + ASSERT_EQ(0, close(server_fd));
You are missing to close client_fd.
> +}
> +
> TEST_HARNESS_MAIN
> --
> 2.34.1
>
