[RFC PATCH v3 08/19] selftests/landlock: Test overlapped restriction

[Günther Noack]

On Wed, Sep 04, 2024 at 06:48:13PM +0800, Mikhail Ivanov wrote:
> Add test that validates Landlock behaviour with overlapped socket
> restriction.
> 
> Signed-off-by: Mikhail Ivanov <ivanov.mikhail1 at huawei-partners.com>
> ---
> Changes since v2:
> * Removes `tcp_layers` fixture and replaces it with `protocol` fixture
>   for this test. protocol.ruleset_overlap tests every layers depth
>   in a single run.
> * Adds add_ruleset_layer() helper that enforces ruleset and allows access
>   if such is given.
> * Replaces EXPECT_EQ with ASSERT_EQ for close().
> * Refactors commit message and title.
> 
> Changes since v1:
> * Replaces test_socket_create() with test_socket().
> * Formats code with clang-format.
> * Refactors commit message.
> * Minor fixes.
> ---
>  .../testing/selftests/landlock/socket_test.c  | 46 +++++++++++++++++++
>  1 file changed, 46 insertions(+)
> 
> diff --git a/tools/testing/selftests/landlock/socket_test.c b/tools/testing/selftests/landlock/socket_test.c
> index d323f649a183..e7b4165a85cd 100644
> --- a/tools/testing/selftests/landlock/socket_test.c
> +++ b/tools/testing/selftests/landlock/socket_test.c
> @@ -417,4 +417,50 @@ TEST_F(protocol, rule_with_empty_access)
>  	ASSERT_EQ(0, close(ruleset_fd));
>  }
>  
> +static void add_ruleset_layer(struct __test_metadata *const _metadata,
> +			      const struct landlock_socket_attr *socket_attr)
> +{
> +	const struct landlock_ruleset_attr ruleset_attr = {
> +		.handled_access_socket = LANDLOCK_ACCESS_SOCKET_CREATE,
> +	};
> +	int ruleset_fd =
> +		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
> +	ASSERT_LE(0, ruleset_fd);
> +
> +	if (socket_attr) {
> +		ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_SOCKET,
> +					       socket_attr, 0));
> +	}
> +
> +	enforce_ruleset(_metadata, ruleset_fd);
> +	ASSERT_EQ(0, close(ruleset_fd));
> +}
> +
> +TEST_F(protocol, ruleset_overlap)
> +{
> +	const struct landlock_socket_attr create_socket_attr = {
> +		.allowed_access = LANDLOCK_ACCESS_SOCKET_CREATE,
> +		.family = self->prot.family,
> +		.type = self->prot.type,
> +	};
> +
> +	/* socket(2) is allowed if there are no restrictions. */
> +	ASSERT_EQ(0, test_socket_variant(&self->prot));
> +
> +	/* Creates ruleset with socket(2) allowed. */
> +	add_ruleset_layer(_metadata, &create_socket_attr);
> +	EXPECT_EQ(0, test_socket_variant(&self->prot));
> +
> +	/* Adds ruleset layer with socket(2) restricted. */
> +	add_ruleset_layer(_metadata, NULL);
> +	EXPECT_EQ(EACCES, test_socket_variant(&self->prot));
> +
> +	/*
> +	 * Adds ruleset layer with socket(2) allowed. socket(2) is restricted
> +	 * by second layer of the ruleset.
> +	 */
> +	add_ruleset_layer(_metadata, &create_socket_attr);
> +	EXPECT_EQ(EACCES, test_socket_variant(&self->prot));
> +}
> +
>  TEST_HARNESS_MAIN
> -- 
> 2.34.1
> 

Reviewed-by: Günther Noack <gnoack at google.com>