[RFC PATCH v3 12/19] selftests/landlock: Test that kernel space sockets are not restricted

[Mikhail Ivanov]

Add test validating that Landlock provides restriction of user space
sockets only.

Signed-off-by: Mikhail Ivanov <ivanov.mikhail1 at huawei-partners.com>
---
 .../testing/selftests/landlock/socket_test.c  | 39 ++++++++++++++++++-
 1 file changed, 38 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/landlock/socket_test.c b/tools/testing/selftests/landlock/socket_test.c
index ff5ace711697..23698b8c2f4d 100644
--- a/tools/testing/selftests/landlock/socket_test.c
+++ b/tools/testing/selftests/landlock/socket_test.c
@@ -7,7 +7,7 @@
 
 #define _GNU_SOURCE
 
-#include <linux/landlock.h>
+#include "landlock.h"
 #include <linux/pfkeyv2.h>
 #include <linux/kcm.h>
 #include <linux/can.h>
@@ -628,4 +628,41 @@ TEST(unsupported_af_and_prot)
 	EXPECT_EQ(ESOCKTNOSUPPORT, test_socket(AF_UNIX, SOCK_PACKET, 0));
 }
 
+TEST(kernel_socket)
+{
+	const struct landlock_ruleset_attr ruleset_attr = {
+		.handled_access_socket = LANDLOCK_ACCESS_SOCKET_CREATE,
+	};
+	struct landlock_socket_attr smc_socket_create = {
+		.allowed_access = LANDLOCK_ACCESS_SOCKET_CREATE,
+		.family = AF_SMC,
+		.type = SOCK_STREAM,
+	};
+	int ruleset_fd;
+
+	/*
+	 * Checks that SMC socket is created sucessfuly without
+	 * landlock restrictions.
+	 */
+	ASSERT_EQ(0, test_socket(AF_SMC, SOCK_STREAM, 0));
+
+	ruleset_fd =
+		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
+	ASSERT_LE(0, ruleset_fd);
+
+	ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_SOCKET,
+				       &smc_socket_create, 0));
+	enforce_ruleset(_metadata, ruleset_fd);
+	ASSERT_EQ(0, close(ruleset_fd));
+
+	/*
+	 * During the creation of an SMC socket, an internal service TCP socket
+	 * is also created (Cf. smc_create_clcsk).
+	 *
+	 * Checks that Landlock does not restrict creation of the kernel space
+	 * socket.
+	 */
+	EXPECT_EQ(0, test_socket(AF_SMC, SOCK_STREAM, 0));
+}
+
 TEST_HARNESS_MAIN
-- 
2.34.1