2/1/2022 9:31 PM, Mickaël Salaün пишет:
On 24/01/2022 09:02, Konstantin Meskhidze wrote:Support 4 tests for bind and connect networks actions:Good to see such tests!1. bind() a socket with no landlock restrictions. 2. bind() sockets with landllock restrictions.You can leverage the FIXTURE_VARIANT helpers to factor out this kind of tests (see ptrace_test.c).
Thanks. I will check this out.
3. connect() a socket to listening one with no landlock restricitons. 4. connect() sockets with landlock restrictions.Same here, you can factor out code. I guess you could create helpers for client and server parts.
Ok. I got it.
We also need to test with IPv4, IPv6 and the AF_UNSPEC tricks.
Yep. I will add AF_UNSPEC case.
Please provide the kernel test coverage and explain why the uncovered code cannot be covered: https://www.kernel.org/doc/html/latest/dev-tools/gcov.html
Thanks for the link. I will check it out.
You'll probably see that there are a multiple parts of the kernel that are not covered. For instance, it is important to test different combinations of layered network rules (see layout1/ruleset_overlap, layer_rule_unions, non_overlapping_accesses, interleaved_masked_accesses… in fs_test.c). Tests in fs_test.c are more complex because handling file system rules is more complex, but you can get some inspiration in it, especially the edge cases.
I got your point. I agree that we need to cover as many network rules combinations as possible.
We also need to test invalid user space supplied data (see layout1/inval test in fs_test.c).
Ok. I will add this kind of test. Thanks.
Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@xxxxxxxxxx> --- .../testing/selftests/landlock/network_test.c | 346 ++++++++++++++++++ 1 file changed, 346 insertions(+) create mode 100644 tools/testing/selftests/landlock/network_test.cdiff --git a/tools/testing/selftests/landlock/network_test.c b/tools/testing/selftests/landlock/network_test.cnew 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@xxxxxxxxxxx> + * Copyright © 2019-2020 ANSSIYou need to update this header with an appropriate description and the copyright holder (your employer).
Ok. I got it.
+ */ + +#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>To make it determinisitic (and ease patching/diff/merging), you should sort all the included files (in tests and in the kernel code).
Sorry. Did not get your point here. Could you explain in a bit more details please.
+ +#include "common.h" + +#define SOCK_PORT_1 3470 +#define SOCK_PORT_2 3480 +#define SOCK_PORT_3 3490To avoid port collision and create a clean and stable test environement (to avoid flaky tests), you should create a network namespace with FIXTURE_SETUP, test with TEST_F_FORK (to not polute the parent process, and which works with test variants), and use the set_cap and clear_cap helpers (see fs_test.c).
Ok. I got it.
+ +#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)));With a dedicated namespace, SO_REUSEADDR should not be required.
Yes. I agree. Will be refactored.
+ + /* 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, + };Good to have these three different rules!+ + 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" */You can omit "object" but use full sentences at the third person (because it explains what do the next lines).
Ok. I got it.
+ 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);Please create all FD with SOCK_CLOEXEC and also close them when not needed. This could also reduce the number of FD.
Ok. Thanks for noticing. It makes sense.
+ 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);These part could be factored out with helpers or/and test variants.
Thanks. Will be factored out.
+ /* 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)));Why is it allowed to bind to SOCK_PORT_3 whereas net_service_3 forbids it?
It's allowed cause net_service_3 has empty access field.
/* 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);
Applying this rule returns ENOMSG errno:
/* Informs about useless rule: empty allowed_access (i.e. deny rules)
* are ignored in network actions
*/
if (!net_service_attr.allowed_access) {
err = -ENOMSG;
goto out_put_ruleset;
}
This means binding socket 3 is not restricted.
For path_beneath_attr.allowed_access = 0 there is the same logic.
+} + +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.
