Test SIOCGSKNS across setns. Create a socket in netns A, switch to netns B, verify SIOCGSKNS still returns netns A. Signed-off-by: Christian Brauner --- .../testing/selftests/namespaces/siocgskns_test.c | 51 ++++++++++++++++++++++ 1 file changed, 51 insertions(+) diff --git a/tools/testing/selftests/namespaces/siocgskns_test.c b/tools/testing/selftests/namespaces/siocgskns_test.c index 3f46ac0c96df..3aed6e3d60a3 100644 --- a/tools/testing/selftests/namespaces/siocgskns_test.c +++ b/tools/testing/selftests/namespaces/siocgskns_test.c @@ -257,4 +257,55 @@ TEST(siocgskns_socket_types) close(sock_udp); } +/* + * Test SIOCGSKNS across setns. + * Create a socket in netns A, switch to netns B, verify SIOCGSKNS still + * returns netns A. + */ +TEST(siocgskns_across_setns) +{ + int sock_fd, netns_a_fd, netns_b_fd, result_fd; + struct stat st_a; + + /* Get current netns (A) */ + netns_a_fd = open("/proc/self/ns/net", O_RDONLY); + ASSERT_GE(netns_a_fd, 0); + ASSERT_EQ(fstat(netns_a_fd, &st_a), 0); + + /* Create socket in netns A */ + sock_fd = socket(AF_INET, SOCK_STREAM, 0); + ASSERT_GE(sock_fd, 0); + + /* Create new netns (B) */ + ASSERT_EQ(unshare(CLONE_NEWNET), 0); + + netns_b_fd = open("/proc/self/ns/net", O_RDONLY); + ASSERT_GE(netns_b_fd, 0); + + /* Get netns from socket created in A */ + result_fd = ioctl(sock_fd, SIOCGSKNS); + if (result_fd < 0) { + close(sock_fd); + setns(netns_a_fd, CLONE_NEWNET); + close(netns_a_fd); + close(netns_b_fd); + if (errno == ENOTTY || errno == EINVAL) + SKIP(return, "SIOCGSKNS not supported"); + ASSERT_GE(result_fd, 0); + } + + /* Verify it still points to netns A */ + struct stat st_result_stat; + ASSERT_EQ(fstat(result_fd, &st_result_stat), 0); + ASSERT_EQ(st_a.st_ino, st_result_stat.st_ino); + + close(result_fd); + close(sock_fd); + close(netns_b_fd); + + /* Restore original netns */ + ASSERT_EQ(setns(netns_a_fd, CLONE_NEWNET), 0); + close(netns_a_fd); +} + TEST_HARNESS_MAIN -- 2.47.3