[PATCH v6 15/17] seltests/landlock: adds ruleset expanding test

[Konstantin Meskhidze <konstantin.meskhidze@huawei.com>]

This patch adds expanding rulesets in which
rules are gradually added one by one, restricting
sockets' connections.

Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com>
---

Changes since v5:
* Formats code with clang-format-14.

Changes since v4:
* Refactors code with self->port, self->addr4 variables.

Changes since v3:
* Adds ruleset_expanding test.

---
 tools/testing/selftests/landlock/net_test.c | 166 ++++++++++++++++++++
 1 file changed, 166 insertions(+)

diff --git a/tools/testing/selftests/landlock/net_test.c b/tools/testing/selftests/landlock/net_test.c
index 18ffd36f959c..a9cb47836a21 100644
--- a/tools/testing/selftests/landlock/net_test.c
+++ b/tools/testing/selftests/landlock/net_test.c
@@ -553,4 +553,170 @@ TEST_F(socket, ruleset_overlap)
 	ASSERT_EQ(0, close(sockfd));
 }

+TEST_F(socket, ruleset_expanding)
+{
+	int sockfd_1, sockfd_2;
+	int one = 1;
+
+	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],
+	};
+
+	const int ruleset_fd_1 = landlock_create_ruleset(
+		&ruleset_attr_1, sizeof(ruleset_attr_1), 0);
+	ASSERT_LE(0, ruleset_fd_1);
+
+	/* Adds rule to 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);
+	ASSERT_EQ(0, close(ruleset_fd_1));
+
+	/* Creates a socket 1. */
+	sockfd_1 = create_socket_variant(variant, SOCK_STREAM);
+	ASSERT_LE(0, sockfd_1);
+	/* Allows to reuse of local address. */
+	ASSERT_EQ(0, setsockopt(sockfd_1, SOL_SOCKET, SO_REUSEADDR, &one,
+				sizeof(one)));
+
+	/* Binds the socket 1 to address with port[0]. */
+	ASSERT_EQ(0, bind_variant(variant, sockfd_1, self, 0));
+
+	/* Makes connection to socket 1 with port[0]. */
+	ASSERT_EQ(0, connect_variant(variant, sockfd_1, self, 0));
+
+	/* Closes socket 1. */
+	ASSERT_EQ(0, close(sockfd_1));
+
+	/* Creates a socket 2. */
+	sockfd_2 = create_socket_variant(variant, SOCK_STREAM);
+	ASSERT_LE(0, sockfd_2);
+	/* Allows to reuse of local address. */
+	ASSERT_EQ(0, setsockopt(sockfd_2, SOL_SOCKET, SO_REUSEADDR, &one,
+				sizeof(one)));
+
+	/*
+	 * Forbids to bind the socket 2 to address with port[1],
+	 * cause there is no rule with bind() access for port[1].
+	 */
+	ASSERT_EQ(-1, bind_variant(variant, sockfd_2, self, 1));
+	ASSERT_EQ(EACCES, errno);
+
+	/* Expands network mask. */
+	struct landlock_ruleset_attr ruleset_attr_2 = {
+		.handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP |
+				      LANDLOCK_ACCESS_NET_CONNECT_TCP,
+	};
+
+	/* Adds connect() access to port[0]. */
+	struct landlock_net_service_attr net_service_2 = {
+		.allowed_access = LANDLOCK_ACCESS_NET_BIND_TCP |
+				  LANDLOCK_ACCESS_NET_CONNECT_TCP,
+
+		.port = self->port[0],
+	};
+	/* Adds bind() access to port[1]. */
+	struct landlock_net_service_attr net_service_3 = {
+		.allowed_access = LANDLOCK_ACCESS_NET_BIND_TCP,
+
+		.port = self->port[1],
+	};
+
+	const int ruleset_fd_2 = landlock_create_ruleset(
+		&ruleset_attr_2, sizeof(ruleset_attr_2), 0);
+	ASSERT_LE(0, ruleset_fd_2);
+
+	/* Adds rule to port[0] socket. */
+	ASSERT_EQ(0, landlock_add_rule(ruleset_fd_2, LANDLOCK_RULE_NET_SERVICE,
+				       &net_service_2, 0));
+	/* Adds rule to port[1] socket. */
+	ASSERT_EQ(0, landlock_add_rule(ruleset_fd_2, LANDLOCK_RULE_NET_SERVICE,
+				       &net_service_3, 0));
+
+	/* Enforces the ruleset. */
+	enforce_ruleset(_metadata, ruleset_fd_2);
+	ASSERT_EQ(0, close(ruleset_fd_2));
+
+	/* Creates a socket 1. */
+	sockfd_1 = create_socket_variant(variant, SOCK_STREAM);
+	ASSERT_LE(0, sockfd_1);
+	/* Allows to reuse of local address. */
+	ASSERT_EQ(0, setsockopt(sockfd_1, SOL_SOCKET, SO_REUSEADDR, &one,
+				sizeof(one)));
+
+	/* Binds the socket 1 to address with port[0]. */
+	ASSERT_EQ(0, bind_variant(variant, sockfd_1, self, 0));
+
+	/* Makes connection to socket 1 with port[0]. */
+	ASSERT_EQ(0, connect_variant(variant, sockfd_1, self, 0));
+
+	/* Closes socket 1. */
+	ASSERT_EQ(0, close(sockfd_1));
+
+	/* Creates a socket 2. */
+	sockfd_2 = create_socket_variant(variant, SOCK_STREAM);
+	ASSERT_LE(0, sockfd_2);
+	/* Allows to reuse of local address. */
+	ASSERT_EQ(0, setsockopt(sockfd_2, SOL_SOCKET, SO_REUSEADDR, &one,
+				sizeof(one)));
+
+	/*
+	 * Forbids to bind the socket 2 to address with port[1],
+	 * cause just one layer has bind() access rule.
+	 */
+	ASSERT_EQ(-1, bind_variant(variant, sockfd_1, self, 1));
+	ASSERT_EQ(EACCES, errno);
+
+	/* Expands network mask. */
+	struct landlock_ruleset_attr ruleset_attr_3 = {
+		.handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP |
+				      LANDLOCK_ACCESS_NET_CONNECT_TCP,
+	};
+
+	/* Restricts connect() access to port[0]. */
+	struct landlock_net_service_attr net_service_4 = {
+		.allowed_access = LANDLOCK_ACCESS_NET_BIND_TCP,
+
+		.port = self->port[0],
+	};
+
+	const int ruleset_fd_3 = landlock_create_ruleset(
+		&ruleset_attr_3, sizeof(ruleset_attr_3), 0);
+	ASSERT_LE(0, ruleset_fd_3);
+
+	/* Adds rule to port[0] socket. */
+	ASSERT_EQ(0, landlock_add_rule(ruleset_fd_3, LANDLOCK_RULE_NET_SERVICE,
+				       &net_service_4, 0));
+
+	/* Enforces the ruleset. */
+	enforce_ruleset(_metadata, ruleset_fd_3);
+	ASSERT_EQ(0, close(ruleset_fd_3));
+
+	/* Creates a socket 1. */
+	sockfd_1 = create_socket_variant(variant, SOCK_STREAM);
+	ASSERT_LE(0, sockfd_1);
+	/* Allows to reuse of local address. */
+	ASSERT_EQ(0, setsockopt(sockfd_1, SOL_SOCKET, SO_REUSEADDR, &one,
+				sizeof(one)));
+
+	/* Binds the socket 1 to address with port[0]. */
+	ASSERT_EQ(0, bind_variant(variant, sockfd_1, self, 0));
+
+	/*
+	 * Forbids to connect the socket 1 to address with port[0],
+	 * cause just one layer has connect() access rule.
+	 */
+	ASSERT_EQ(-1, connect_variant(variant, sockfd_1, self, 0));
+	ASSERT_EQ(EACCES, errno);
+
+	/* Closes socket 1. */
+	ASSERT_EQ(0, close(sockfd_1));
+}
 TEST_HARNESS_MAIN
--
2.25.1