[PATCH v5 09/15] seltests/landlock: add tests for bind() hooks

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

Adds selftests for bind socket action.
The first is with no landlock restrictions:
    - bind_no_restrictions_ip4;
    - bind_no_restrictions_ip6;
The second ones is with mixed landlock rules:
    - bind_with_restrictions_ip4;
    - bind_with_restrictions_ip6;

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

Changes since v3:
* Split commit.
* Add helper create_socket.
* Add FIXTURE_SETUP.

Changes since v4:
* Adds port[MAX_SOCKET_NUM], struct sockaddr_in addr4
and struct sockaddr_in addr6 in FIXTURE.
* Refactoring FIXTURE_SETUP:
    - initializing self->port, self->addr4 and self->addr6.
    - adding network namespace.
* Refactoring code with self->port, self->addr4 and
self->addr6 variables.
* Adds selftests for IP6 family:
    - bind_no_restrictions_ip6.
    - bind_with_restrictions_ip6.
* Refactoring selftests/landlock/config
* Moves enforce_ruleset() into common.h

---
 tools/testing/selftests/landlock/common.h   |   9 +
 tools/testing/selftests/landlock/config     |   5 +-
 tools/testing/selftests/landlock/fs_test.c  |  10 -
 tools/testing/selftests/landlock/net_test.c | 237 ++++++++++++++++++++
 4 files changed, 250 insertions(+), 11 deletions(-)
 create mode 100644 tools/testing/selftests/landlock/net_test.c

diff --git a/tools/testing/selftests/landlock/common.h b/tools/testing/selftests/landlock/common.h
index 7ba18eb23783..c5381e641dfd 100644
--- a/tools/testing/selftests/landlock/common.h
+++ b/tools/testing/selftests/landlock/common.h
@@ -102,6 +102,15 @@ static inline int landlock_restrict_self(const int ruleset_fd,
 }
 #endif

+static void enforce_ruleset(struct __test_metadata *const _metadata,
+		const int ruleset_fd)
+{
+	ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0));
+	ASSERT_EQ(0, landlock_restrict_self(ruleset_fd, 0)) {
+		TH_LOG("Failed to enforce ruleset: %s", strerror(errno));
+	}
+}
+
 static void _init_caps(struct __test_metadata *const _metadata, bool drop_all)
 {
 	cap_t cap_p;
diff --git a/tools/testing/selftests/landlock/config b/tools/testing/selftests/landlock/config
index 0f0a65287bac..b56f3274d3f5 100644
--- a/tools/testing/selftests/landlock/config
+++ b/tools/testing/selftests/landlock/config
@@ -1,7 +1,10 @@
+CONFIG_INET=y
+CONFIG_IPV6=y
+CONFIG_NET=y
 CONFIG_OVERLAY_FS=y
 CONFIG_SECURITY_LANDLOCK=y
 CONFIG_SECURITY_PATH=y
 CONFIG_SECURITY=y
 CONFIG_SHMEM=y
 CONFIG_TMPFS_XATTR=y
-CONFIG_TMPFS=y
+CONFIG_TMPFS=y
\ No newline at end of file
diff --git a/tools/testing/selftests/landlock/fs_test.c b/tools/testing/selftests/landlock/fs_test.c
index 21a2ce8fa739..036dd6f8f9ea 100644
--- a/tools/testing/selftests/landlock/fs_test.c
+++ b/tools/testing/selftests/landlock/fs_test.c
@@ -551,16 +551,6 @@ static int create_ruleset(struct __test_metadata *const _metadata,
 	return ruleset_fd;
 }

-static void enforce_ruleset(struct __test_metadata *const _metadata,
-			    const int ruleset_fd)
-{
-	ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0));
-	ASSERT_EQ(0, landlock_restrict_self(ruleset_fd, 0))
-	{
-		TH_LOG("Failed to enforce ruleset: %s", strerror(errno));
-	}
-}
-
 TEST_F_FORK(layout1, proc_nsfs)
 {
 	const struct rule rules[] = {
diff --git a/tools/testing/selftests/landlock/net_test.c b/tools/testing/selftests/landlock/net_test.c
new file mode 100644
index 000000000000..478ef2eff559
--- /dev/null
+++ b/tools/testing/selftests/landlock/net_test.c
@@ -0,0 +1,237 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Landlock tests - Network
+ *
+ * Copyright (C) 2022 Huawei Tech. Co., Ltd.
+ */
+
+#define _GNU_SOURCE
+#include <arpa/inet.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/landlock.h>
+#include <netinet/in.h>
+#include <sched.h>
+#include <string.h>
+#include <sys/prctl.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+
+#include "common.h"
+
+#define MAX_SOCKET_NUM 10
+
+#define SOCK_PORT_START 3470
+#define SOCK_PORT_ADD 10
+
+#define IP_ADDRESS "127.0.0.1"
+
+/* Number pending connections queue to be hold */
+#define BACKLOG 10
+
+static int create_socket(struct __test_metadata *const _metadata,
+			bool ip6, bool reuse_addr)
+{
+		int sockfd;
+		int one = 1;
+
+		if (ip6)
+			sockfd = socket(AF_INET6, SOCK_STREAM | SOCK_CLOEXEC, 0);
+		else
+			sockfd = socket(AF_INET, SOCK_STREAM | SOCK_CLOEXEC, 0);
+
+		ASSERT_LE(0, sockfd);
+		/* Allows to reuse of local address */
+		if (reuse_addr)
+			ASSERT_EQ(0, setsockopt(sockfd, SOL_SOCKET,
+					SO_REUSEADDR, &one, sizeof(one)));
+		return sockfd;
+}
+
+FIXTURE(socket_test) {
+	uint port[MAX_SOCKET_NUM];
+	struct sockaddr_in addr4[MAX_SOCKET_NUM];
+	struct sockaddr_in6 addr6[MAX_SOCKET_NUM];
+};
+
+FIXTURE_SETUP(socket_test)
+{
+	int i;
+	/* Creates IP4 socket addresses */
+	for (i = 0; i < MAX_SOCKET_NUM; i++) {
+		self->port[i] = SOCK_PORT_START + SOCK_PORT_ADD*i;
+		self->addr4[i].sin_family = AF_INET;
+		self->addr4[i].sin_port = htons(self->port[i]);
+		self->addr4[i].sin_addr.s_addr = htonl(INADDR_ANY);
+		memset(&(self->addr4[i].sin_zero), '\0', 8);
+	}
+
+	/* Creates IP6 socket addresses */
+	for (i = 0; i < MAX_SOCKET_NUM; i++) {
+		self->port[i] = SOCK_PORT_START + SOCK_PORT_ADD*i;
+		self->addr6[i].sin6_family = AF_INET6;
+		self->addr6[i].sin6_port = htons(self->port[i]);
+		self->addr6[i].sin6_addr = in6addr_any;
+	}
+
+	set_cap(_metadata, CAP_SYS_ADMIN);
+	ASSERT_EQ(0, unshare(CLONE_NEWNET));
+	ASSERT_EQ(0, system("ip link set dev lo up"));
+	clear_cap(_metadata, CAP_SYS_ADMIN);
+}
+
+FIXTURE_TEARDOWN(socket_test)
+{ }
+
+TEST_F_FORK(socket_test, bind_no_restrictions_ip4) {
+
+	int sockfd;
+
+	sockfd = create_socket(_metadata, false, false);
+	ASSERT_LE(0, sockfd);
+
+	/* Binds a socket to port[0] */
+	ASSERT_EQ(0, bind(sockfd, (struct sockaddr *)&self->addr4[0], sizeof(self->addr4[0])));
+
+	ASSERT_EQ(0, close(sockfd));
+}
+
+TEST_F_FORK(socket_test, bind_no_restrictions_ip6) {
+
+	int sockfd;
+
+	sockfd = create_socket(_metadata, true, false);
+	ASSERT_LE(0, sockfd);
+
+	/* Binds a socket to port[0] */
+	ASSERT_EQ(0, bind(sockfd, (struct sockaddr *)&self->addr6[0], sizeof(self->addr6[0])));
+
+	ASSERT_EQ(0, close(sockfd));
+}
+
+TEST_F_FORK(socket_test, bind_with_restrictions_ip4) {
+
+	int sockfd;
+
+	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 = self->port[0],
+	};
+	struct landlock_net_service_attr net_service_2 = {
+		.allowed_access = LANDLOCK_ACCESS_NET_CONNECT_TCP,
+		.port = self->port[1],
+	};
+	struct landlock_net_service_attr net_service_3 = {
+		.allowed_access = 0,
+		.port = self->port[2],
+	};
+
+	const int ruleset_fd = landlock_create_ruleset(&ruleset_attr,
+			sizeof(ruleset_attr), 0);
+	ASSERT_LE(0, ruleset_fd);
+
+	/* Allows connect and bind operations to the port[0] socket. */
+	ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_NET_SERVICE,
+				&net_service_1, 0));
+	/* Allows connect and deny bind operations to the port[1] socket. */
+	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 port[2] socket.
+	 */
+	ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_NET_SERVICE,
+				&net_service_3, 0));
+	ASSERT_EQ(ENOMSG, errno);
+
+	/* Enforces the ruleset. */
+	enforce_ruleset(_metadata, ruleset_fd);
+
+	sockfd = create_socket(_metadata, false, false);
+	ASSERT_LE(0, sockfd);
+	/* Binds a socket to port[0] */
+	ASSERT_EQ(0, bind(sockfd, (struct sockaddr *)&self->addr4[0], sizeof(self->addr4[0])));
+
+	/* Close bounded socket*/
+	ASSERT_EQ(0, close(sockfd));
+
+	sockfd = create_socket(_metadata, false, false);
+	ASSERT_LE(0, sockfd);
+	/* Binds a socket to port[1] */
+	ASSERT_EQ(-1, bind(sockfd, (struct sockaddr *)&self->addr4[1], sizeof(self->addr4[1])));
+	ASSERT_EQ(EACCES, errno);
+
+	sockfd = create_socket(_metadata, false, false);
+	ASSERT_LE(0, sockfd);
+	/* Binds a socket to port[2] */
+	ASSERT_EQ(-1, bind(sockfd, (struct sockaddr *)&self->addr4[2], sizeof(self->addr4[2])));
+	ASSERT_EQ(EACCES, errno);
+}
+
+TEST_F_FORK(socket_test, bind_with_restrictions_ip6) {
+
+	int sockfd;
+
+	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 = self->port[0],
+	};
+	struct landlock_net_service_attr net_service_2 = {
+		.allowed_access = LANDLOCK_ACCESS_NET_CONNECT_TCP,
+		.port = self->port[1],
+	};
+	struct landlock_net_service_attr net_service_3 = {
+		.allowed_access = 0,
+		.port = self->port[2],
+	};
+
+	const int ruleset_fd = landlock_create_ruleset(&ruleset_attr,
+			sizeof(ruleset_attr), 0);
+	ASSERT_LE(0, ruleset_fd);
+
+	/* Allows connect and bind operations to the port[0] socket. */
+	ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_NET_SERVICE,
+				&net_service_1, 0));
+	/* Allows connect and deny bind operations to the port[1] socket. */
+	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 port[2] socket.
+	 */
+	ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_NET_SERVICE,
+				&net_service_3, 0));
+	ASSERT_EQ(ENOMSG, errno);
+
+	/* Enforces the ruleset. */
+	enforce_ruleset(_metadata, ruleset_fd);
+
+	sockfd = create_socket(_metadata, true, false);
+	ASSERT_LE(0, sockfd);
+	/* Binds a socket to port[0] */
+	ASSERT_EQ(0, bind(sockfd, (struct sockaddr *)&self->addr6[0], sizeof(self->addr6[0])));
+
+	/* Close bounded socket*/
+	ASSERT_EQ(0, close(sockfd));
+
+	sockfd = create_socket(_metadata, false, false);
+	ASSERT_LE(0, sockfd);
+	/* Binds a socket to port[1] */
+	ASSERT_EQ(-1, bind(sockfd, (struct sockaddr *)&self->addr6[1], sizeof(self->addr6[1])));
+	ASSERT_EQ(EACCES, errno);
+
+	sockfd = create_socket(_metadata, false, false);
+	ASSERT_LE(0, sockfd);
+	/* Binds a socket to port[2] */
+	ASSERT_EQ(-1, bind(sockfd, (struct sockaddr *)&self->addr6[2], sizeof(self->addr6[2])));
+	ASSERT_EQ(EACCES, errno);
+}
+TEST_HARNESS_MAIN
--
2.25.1