[RFC PATCH 2/2] landlock: selftests for bind and connect hooks

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

Support 4 tests for bind and connect networks actions:
1. bind() a socket with no landlock restrictions.
2. bind() sockets with landllock restrictions.
3. connect() a socket to listening one with no landlock restricitons.
4. connect() sockets with landlock restrictions.

Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com>
---
 .../testing/selftests/landlock/network_test.c | 346 ++++++++++++++++++
 1 file changed, 346 insertions(+)
 create mode 100644 tools/testing/selftests/landlock/network_test.c

diff --git a/tools/testing/selftests/landlock/network_test.c b/tools/testing/selftests/landlock/network_test.c
new file mode 100644
index 000000000000..9dfe37a2fb20
--- /dev/null
+++ b/tools/testing/selftests/landlock/network_test.c
@@ -0,0 +1,346 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Landlock tests - Common user space base
+ *
+ * Copyright © 2017-2020 Mickaël Salaün <mic@digikod.net>
+ * Copyright © 2019-2020 ANSSI
+ */
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/landlock.h>
+#include <string.h>
+#include <sys/prctl.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+#include "common.h"
+
+#define SOCK_PORT_1 3470
+#define SOCK_PORT_2 3480
+#define SOCK_PORT_3 3490
+
+#define IP_ADDRESS "127.0.0.1"
+
+/* Number pending connections queue tobe hold */
+#define BACKLOG 10
+
+TEST(socket_bind_no_restrictions) {
+
+	int sockfd;
+	struct sockaddr_in addr;
+	const int one = 1;
+
+	/* Create a socket */
+	sockfd = socket(AF_INET, SOCK_STREAM, 0);
+	ASSERT_LE(0, sockfd);
+	/* Allow reuse of local addresses */
+	ASSERT_EQ(0, setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)));
+
+	/* Set socket address parameters */
+	addr.sin_family = AF_INET;
+	addr.sin_port = htons(SOCK_PORT_1);
+	addr.sin_addr.s_addr = inet_addr(IP_ADDRESS);
+	memset(&(addr.sin_zero), '\0', 8);
+
+	/* Bind the socket to IP address */
+	ASSERT_EQ(0, bind(sockfd, (struct sockaddr *)&addr, sizeof(addr)));
+}
+
+TEST(sockets_bind_with_restrictions) {
+
+	int sockfd_1, sockfd_2, sockfd_3;
+	struct sockaddr_in addr_1, addr_2, addr_3;
+	const int one = 1;
+
+	struct landlock_ruleset_attr ruleset_attr = {
+		.handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP |
+				      LANDLOCK_ACCESS_NET_CONNECT_TCP,
+	};
+	struct landlock_net_service_attr net_service_1 = {
+		.allowed_access = LANDLOCK_ACCESS_NET_BIND_TCP |
+				  LANDLOCK_ACCESS_NET_CONNECT_TCP,
+		.port = SOCK_PORT_1,
+	};
+	struct landlock_net_service_attr net_service_2 = {
+		.allowed_access = LANDLOCK_ACCESS_NET_CONNECT_TCP,
+		.port = SOCK_PORT_2,
+	};
+	struct landlock_net_service_attr net_service_3 = {
+		.allowed_access = 0,
+		.port = SOCK_PORT_3,
+	};
+
+	const int ruleset_fd = landlock_create_ruleset(&ruleset_attr,
+			sizeof(ruleset_attr), 0);
+	ASSERT_LE(0, ruleset_fd);
+
+	/* Allow connect and bind operations to the SOCK_PORT_1 socket "object" */
+	ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_NET_SERVICE,
+				&net_service_1, 0));
+	/* Allow connect and deny bind operations to the SOCK_PORT_2 socket "object" */
+	ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_NET_SERVICE,
+				&net_service_2, 0));
+	/* Empty allowed_access (i.e. deny rules) are ignored in network actions
+	 * for SOCK_PORT_3 socket "object"
+	 */
+	ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_NET_SERVICE,
+				&net_service_3, 0));
+	ASSERT_EQ(ENOMSG, errno);
+
+	/* Enforces the ruleset. */
+	ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0));
+	ASSERT_EQ(0, landlock_restrict_self(ruleset_fd, 0));
+	ASSERT_EQ(0, close(ruleset_fd));
+
+	/* Create a socket 1 */
+	sockfd_1 = socket(AF_INET, SOCK_STREAM, 0);
+	ASSERT_LE(0, sockfd_1);
+	/* Allow reuse of local addresses */
+	ASSERT_EQ(0, setsockopt(sockfd_1, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)));
+
+	/* Set socket 1 address parameters */
+	addr_1.sin_family = AF_INET;
+	addr_1.sin_port = htons(SOCK_PORT_1);
+	addr_1.sin_addr.s_addr = inet_addr(IP_ADDRESS);
+	memset(&(addr_1.sin_zero), '\0', 8);
+	/* Bind the socket 1 to IP address */
+	ASSERT_EQ(0, bind(sockfd_1, (struct sockaddr  *)&addr_1, sizeof(addr_1)));
+
+	/* Create a socket 2 */
+	sockfd_2 = socket(AF_INET, SOCK_STREAM, 0);
+	ASSERT_LE(0, sockfd_2);
+	/* Allow reuse of local addresses */
+	ASSERT_EQ(0, setsockopt(sockfd_2, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)));
+
+	/* Set socket 2 address parameters */
+	addr_2.sin_family = AF_INET;
+	addr_2.sin_port = htons(SOCK_PORT_2);
+	addr_2.sin_addr.s_addr = inet_addr(IP_ADDRESS);
+	memset(&(addr_2.sin_zero), '\0', 8);
+	/* Bind the socket 2 to IP address */
+	ASSERT_EQ(-1, bind(sockfd_2, (struct sockaddr *)&addr_2, sizeof(addr_2)));
+	ASSERT_EQ(EACCES, errno);
+
+	/* Create a socket 3 */
+	sockfd_3 = socket(AF_INET, SOCK_STREAM, 0);
+	ASSERT_LE(0, sockfd_3);
+	/* Allow reuse of local addresses */
+	ASSERT_EQ(0, setsockopt(sockfd_3, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)));
+
+	/* Set socket 3 address parameters */
+	addr_3.sin_family = AF_INET;
+	addr_3.sin_port = htons(SOCK_PORT_3);
+	addr_3.sin_addr.s_addr = inet_addr(IP_ADDRESS);
+	memset(&(addr_3.sin_zero), '\0', 8);
+	/* Bind the socket 3 to IP address */
+	ASSERT_EQ(0, bind(sockfd_3, (struct sockaddr *)&addr_3, sizeof(addr_3)));
+}
+
+TEST(socket_connect_no_restrictions) {
+
+	int sockfd, new_fd;
+	struct sockaddr_in addr;
+	pid_t child;
+	int status;
+	const int one = 1;
+
+	/* Create a server socket */
+	sockfd = socket(AF_INET, SOCK_STREAM, 0);
+	ASSERT_LE(0, sockfd);
+	/* Allow reuse of local addresses */
+	ASSERT_EQ(0, setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)));
+
+	/* Set socket address parameters */
+	addr.sin_family = AF_INET;
+	addr.sin_port = htons(SOCK_PORT_1);
+	addr.sin_addr.s_addr = inet_addr(IP_ADDRESS);
+	memset(&(addr.sin_zero), '\0', 8);
+
+	/* Bind the socket to IP address */
+	ASSERT_EQ(0, bind(sockfd, (struct sockaddr *)&addr, sizeof(addr)));
+
+	/* Make listening socket */
+	ASSERT_EQ(0, listen(sockfd, BACKLOG));
+
+	child = fork();
+	ASSERT_LE(0, child);
+	if (child == 0) {
+		int child_sockfd;
+		struct sockaddr_in connect_addr;
+
+		/* Close listening socket for the child */
+		ASSERT_EQ(0, close(sockfd));
+		/* Create a stream client socket */
+		child_sockfd = socket(AF_INET, SOCK_STREAM, 0);
+		ASSERT_LE(0, child_sockfd);
+
+		/* Set server's socket address parameters*/
+		connect_addr.sin_family = AF_INET;
+		connect_addr.sin_port = htons(SOCK_PORT_1);
+		connect_addr.sin_addr.s_addr = htonl(INADDR_ANY);
+		memset(&(connect_addr.sin_zero), '\0', 8);
+
+		/* Make connection to the listening socket */
+		ASSERT_EQ(0, connect(child_sockfd, (struct sockaddr *)&connect_addr,
+					   sizeof(struct sockaddr)));
+		_exit(_metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE);
+		return;
+	}
+	/* Accept connection from the child */
+	new_fd = accept(sockfd, NULL, 0);
+	ASSERT_LE(0, new_fd);
+
+	/* Close connection */
+	ASSERT_EQ(0, close(new_fd));
+
+	ASSERT_EQ(child, waitpid(child, &status, 0));
+	ASSERT_EQ(1, WIFEXITED(status));
+	ASSERT_EQ(EXIT_SUCCESS, WEXITSTATUS(status));
+}
+
+TEST(sockets_connect_with_restrictions) {
+
+	int new_fd;
+	int sockfd_1, sockfd_2;
+	struct sockaddr_in addr_1, addr_2;
+	pid_t child_1, child_2;
+	int status;
+	const int one = 1;
+
+	struct landlock_ruleset_attr ruleset_attr = {
+		.handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP |
+				      LANDLOCK_ACCESS_NET_CONNECT_TCP,
+	};
+	struct landlock_net_service_attr net_service_1 = {
+		.allowed_access = LANDLOCK_ACCESS_NET_BIND_TCP |
+				  LANDLOCK_ACCESS_NET_CONNECT_TCP,
+		.port = SOCK_PORT_1,
+	};
+	struct landlock_net_service_attr net_service_2 = {
+		.allowed_access = LANDLOCK_ACCESS_NET_BIND_TCP,
+		.port = SOCK_PORT_2,
+	};
+
+	const int ruleset_fd = landlock_create_ruleset(&ruleset_attr,
+			sizeof(ruleset_attr), 0);
+	ASSERT_LE(0, ruleset_fd);
+
+	/* Allow connect and bind operations to the SOCK_PORT_1 socket "object" */
+	ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_NET_SERVICE,
+				&net_service_1, 0));
+	/* Allow connect and deny bind operations to the SOCK_PORT_2 socket "object" */
+	ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_NET_SERVICE,
+				&net_service_2, 0));
+
+	/* Enforces the ruleset. */
+	ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0));
+	ASSERT_EQ(0, landlock_restrict_self(ruleset_fd, 0));
+	ASSERT_EQ(0, close(ruleset_fd));
+
+	/* Create a server socket 1 */
+	sockfd_1 = socket(AF_INET, SOCK_STREAM, 0);
+	ASSERT_LE(0, sockfd_1);
+	/* Allow reuse of local addresses */
+	ASSERT_EQ(0, setsockopt(sockfd_1, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)));
+
+	/* Set socket 1 address parameters */
+	addr_1.sin_family = AF_INET;
+	addr_1.sin_port = htons(SOCK_PORT_1);
+	addr_1.sin_addr.s_addr = inet_addr(IP_ADDRESS);
+	memset(&(addr_1.sin_zero), '\0', 8);
+
+	/* Bind the socket 1 to IP address */
+	ASSERT_EQ(0, bind(sockfd_1, (struct sockaddr *)&addr_1, sizeof(addr_1)));
+
+	/* Make listening socket 1 */
+	ASSERT_EQ(0, listen(sockfd_1, BACKLOG));
+
+	child_1 = fork();
+	ASSERT_LE(0, child_1);
+	if (child_1 == 0) {
+		int child_sockfd;
+		struct sockaddr_in connect_addr;
+
+		/* Close listening socket for the child */
+		ASSERT_EQ(0, close(sockfd_1));
+		/* Create a stream client socket */
+		child_sockfd = socket(AF_INET, SOCK_STREAM, 0);
+		ASSERT_LE(0, child_sockfd);
+
+		/* Set server's socket 1 address parameters*/
+		connect_addr.sin_family = AF_INET;
+		connect_addr.sin_port = htons(SOCK_PORT_1);
+		connect_addr.sin_addr.s_addr = htonl(INADDR_ANY);
+		memset(&(connect_addr.sin_zero), '\0', 8);
+
+		/* Make connection to the listening socket 1 */
+		ASSERT_EQ(0, connect(child_sockfd, (struct sockaddr *)&connect_addr,
+					   sizeof(struct sockaddr)));
+		_exit(_metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE);
+		return;
+	}
+	/* Accept connection from the child 1 */
+	new_fd = accept(sockfd_1, NULL, 0);
+	ASSERT_LE(0, new_fd);
+
+	/* Close connection */
+	ASSERT_EQ(0, close(new_fd));
+
+	ASSERT_EQ(child_1, waitpid(child_1, &status, 0));
+	ASSERT_EQ(1, WIFEXITED(status));
+	ASSERT_EQ(EXIT_SUCCESS, WEXITSTATUS(status));
+
+	/* Create a server socket 2 */
+	sockfd_2 = socket(AF_INET, SOCK_STREAM, 0);
+	ASSERT_LE(0, sockfd_2);
+	/* Allow reuse of local addresses */
+	ASSERT_EQ(0, setsockopt(sockfd_2, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)));
+
+	/* Set socket 2 address parameters */
+	addr_2.sin_family = AF_INET;
+	addr_2.sin_port = htons(SOCK_PORT_2);
+	addr_2.sin_addr.s_addr = inet_addr(IP_ADDRESS);
+	memset(&(addr_2.sin_zero), '\0', 8);
+
+	/* Bind the socket 2 to IP address */
+	ASSERT_EQ(0, bind(sockfd_2, (struct sockaddr *)&addr_2, sizeof(addr_2)));
+
+	/* Make listening socket 2 */
+	ASSERT_EQ(0, listen(sockfd_2, BACKLOG));
+
+	child_2 = fork();
+	ASSERT_LE(0, child_2);
+	if (child_2 == 0) {
+		int child_sockfd;
+		struct sockaddr_in connect_addr;
+
+		/* Close listening socket for the child */
+		ASSERT_EQ(0, close(sockfd_2));
+		/* Create a stream client socket */
+		child_sockfd = socket(AF_INET, SOCK_STREAM, 0);
+		ASSERT_LE(0, child_sockfd);
+
+		/* Set server's socket address parameters*/
+		connect_addr.sin_family = AF_INET;
+		connect_addr.sin_port = htons(SOCK_PORT_2);
+		connect_addr.sin_addr.s_addr = htonl(INADDR_ANY);
+		memset(&(connect_addr.sin_zero), '\0', 8);
+
+		/* Make connection to the listening socket */
+		ASSERT_EQ(-1, connect(child_sockfd, (struct sockaddr *)&connect_addr,
+					   sizeof(struct sockaddr)));
+		ASSERT_EQ(EACCES, errno);
+		_exit(_metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE);
+		return;
+	}
+
+	ASSERT_EQ(child_2, waitpid(child_2, &status, 0));
+	ASSERT_EQ(1, WIFEXITED(status));
+	ASSERT_EQ(EXIT_SUCCESS, WEXITSTATUS(status));
+}
+
+TEST_HARNESS_MAIN
-- 
2.25.1