Adds selftests for bind() socket action. The first is with no landlock restrictions: - bind without restrictions for ip4; - bind without restrictions for ip6; The second ones is with mixed landlock rules: - bind with restrictions for ip4; - bind with restrictions for ip6; Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@xxxxxxxxxx> --- Changes since v5: * Splits commit. * Adds local address 127.0.0.1. * Adds FIXTURE_VARIANT and FIXTURE_VARIANT_ADD helpers to support both ip4 and ip6 family tests and shorten the code. * Adds create_socket_variant() and bind_variant() helpers. * Gets rid of reuse_addr variable in create_socket_variant. * Formats code with clang-format-14. Changes since v4: * Adds port[MAX_SOCKET_NUM], struct sockaddr_in addr4 and struct sockaddr_in addr6 in FIXTURE. * Refactors FIXTURE_SETUP: - initializing self->port, self->addr4 and self->addr6. - adding network namespace. * Refactors code with self->port, self->addr4 and self->addr6 variables. * Adds selftests for IP6 family: - bind_no_restrictions_ip6. - bind_with_restrictions_ip6. * Refactors selftests/landlock/config * Moves enforce_ruleset() into common.h Changes since v3: * Split commit. * Add helper create_socket. * Add FIXTURE_SETUP. --- tools/testing/selftests/landlock/config | 4 + tools/testing/selftests/landlock/net_test.c | 180 ++++++++++++++++++++ 2 files changed, 184 insertions(+) create mode 100644 tools/testing/selftests/landlock/net_test.c diff --git a/tools/testing/selftests/landlock/config b/tools/testing/selftests/landlock/config index 0f0a65287bac..71f7e9a8a64c 100644 --- a/tools/testing/selftests/landlock/config +++ b/tools/testing/selftests/landlock/config @@ -1,3 +1,7 @@ +CONFIG_INET=y +CONFIG_IPV6=y +CONFIG_NET=y +CONFIG_NET_NS=y CONFIG_OVERLAY_FS=y CONFIG_SECURITY_LANDLOCK=y CONFIG_SECURITY_PATH=y diff --git a/tools/testing/selftests/landlock/net_test.c b/tools/testing/selftests/landlock/net_test.c new file mode 100644 index 000000000000..a0e02b6bd79f --- /dev/null +++ b/tools/testing/selftests/landlock/net_test.c @@ -0,0 +1,180 @@ +// 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" + +FIXTURE(socket) +{ + uint port[MAX_SOCKET_NUM]; + struct sockaddr_in addr4[MAX_SOCKET_NUM]; + struct sockaddr_in6 addr6[MAX_SOCKET_NUM]; +}; + +FIXTURE_VARIANT(socket) +{ + const bool is_ipv4; +}; + +/* clang-format off */ +FIXTURE_VARIANT_ADD(socket, ipv4) { + /* clang-format on */ + .is_ipv4 = true, +}; + +/* clang-format off */ +FIXTURE_VARIANT_ADD(socket, ipv6) { + /* clang-format on */ + .is_ipv4 = false, +}; + +static int create_socket_variant(const FIXTURE_VARIANT(socket) * const variant, + const int type) +{ + if (variant->is_ipv4) + return socket(AF_INET, type | SOCK_CLOEXEC, 0); + else + return socket(AF_INET6, type | SOCK_CLOEXEC, 0); +} + +static int bind_variant(const FIXTURE_VARIANT(socket) * const variant, + const int sockfd, + const FIXTURE_DATA(socket) * const self, + const size_t index) +{ + if (variant->is_ipv4) + return bind(sockfd, &self->addr4[index], + sizeof(self->addr4[index])); + else + return bind(sockfd, &self->addr6[index], + sizeof(self->addr6[index])); +} + +FIXTURE_SETUP(socket) +{ + 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 = inet_addr(IP_ADDRESS); + 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]); + inet_pton(AF_INET6, IP_ADDRESS, &(self->addr6[i].sin6_addr)); + } + + 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_F(socket, bind_no_restrictions) +{ + int sockfd; + + sockfd = create_socket_variant(variant, SOCK_STREAM); + ASSERT_LE(0, sockfd); + + /* Binds a socket to port[0]. */ + ASSERT_EQ(0, bind_variant(variant, sockfd, self, 0)); + + ASSERT_EQ(0, close(sockfd)); +} + +TEST_F(socket, bind_with_restrictions) +{ + 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_variant(variant, SOCK_STREAM); + ASSERT_LE(0, sockfd); + /* Binds a socket to port[0]. */ + ASSERT_EQ(0, bind_variant(variant, sockfd, self, 0)); + + /* Close bounded socket. */ + ASSERT_EQ(0, close(sockfd)); + + sockfd = create_socket_variant(variant, SOCK_STREAM); + ASSERT_LE(0, sockfd); + /* Binds a socket to port[1]. */ + ASSERT_EQ(-1, bind_variant(variant, sockfd, self, 1)); + ASSERT_EQ(EACCES, errno); + + sockfd = create_socket_variant(variant, SOCK_STREAM); + ASSERT_LE(0, sockfd); + /* Binds a socket to port[2]. */ + ASSERT_EQ(-1, bind_variant(variant, sockfd, self, 2)); + ASSERT_EQ(EACCES, errno); +} +TEST_HARNESS_MAIN -- 2.25.1