Test combined listns() and file handle operations with socket-kept netns. Create a netns, keep it alive with a socket, verify it appears in listns(), then reopen it via file handle obtained from listns() entry. Signed-off-by: Christian Brauner --- .../testing/selftests/namespaces/siocgskns_test.c | 291 +++++++++++++++++++++ 1 file changed, 291 insertions(+) diff --git a/tools/testing/selftests/namespaces/siocgskns_test.c b/tools/testing/selftests/namespaces/siocgskns_test.c index 0ea5241f2b6f..a5a96509661e 100644 --- a/tools/testing/selftests/namespaces/siocgskns_test.c +++ b/tools/testing/selftests/namespaces/siocgskns_test.c @@ -984,4 +984,295 @@ TEST(siocgskns_file_handle) free(handle); } +/* + * Test combined listns() and file handle operations with socket-kept netns. + * Create a netns, keep it alive with a socket, verify it appears in listns(), + * then reopen it via file handle obtained from listns() entry. + */ +TEST(siocgskns_listns_and_file_handle) +{ + int sock_fd, netns_fd, userns_fd, reopened_fd; + int ipc_sockets[2]; + pid_t pid; + int status; + struct stat st; + ino_t netns_ino; + __u64 netns_id, userns_id; + struct ns_id_req req = { + .size = sizeof(req), + .spare = 0, + .ns_id = 0, + .ns_type = CLONE_NEWNET | CLONE_NEWUSER, + .spare2 = 0, + .user_ns_id = 0, + }; + __u64 ns_ids[256]; + int ret, i; + bool found_netns = false, found_userns = false; + struct file_handle *handle; + struct nsfs_file_handle *nsfs_fh; + + /* Allocate file_handle structure for nsfs */ + handle = malloc(sizeof(struct file_handle) + sizeof(struct nsfs_file_handle)); + ASSERT_NE(handle, NULL); + handle->handle_bytes = sizeof(struct nsfs_file_handle); + handle->handle_type = FILEID_NSFS; + + EXPECT_EQ(socketpair(AF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, ipc_sockets), 0); + + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) { + /* Child: create new userns and netns with socket */ + close(ipc_sockets[0]); + + if (setup_userns() < 0) { + close(ipc_sockets[1]); + exit(1); + } + + if (unshare(CLONE_NEWNET) < 0) { + close(ipc_sockets[1]); + exit(1); + } + + sock_fd = socket(AF_INET, SOCK_DGRAM, 0); + if (sock_fd < 0) { + close(ipc_sockets[1]); + exit(1); + } + + /* Send socket FD to parent via SCM_RIGHTS */ + struct msghdr msg = {0}; + struct iovec iov = {0}; + char buf[1] = {'X'}; + char cmsg_buf[CMSG_SPACE(sizeof(int))]; + + iov.iov_base = buf; + iov.iov_len = 1; + msg.msg_iov = &iov; + msg.msg_iovlen = 1; + msg.msg_control = cmsg_buf; + msg.msg_controllen = sizeof(cmsg_buf); + + struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg); + cmsg->cmsg_level = SOL_SOCKET; + cmsg->cmsg_type = SCM_RIGHTS; + cmsg->cmsg_len = CMSG_LEN(sizeof(int)); + memcpy(CMSG_DATA(cmsg), &sock_fd, sizeof(int)); + + if (sendmsg(ipc_sockets[1], &msg, 0) < 0) { + close(sock_fd); + close(ipc_sockets[1]); + exit(1); + } + + close(sock_fd); + close(ipc_sockets[1]); + exit(0); + } + + /* Parent: receive socket FD */ + close(ipc_sockets[1]); + + struct msghdr msg = {0}; + struct iovec iov = {0}; + char buf[1]; + char cmsg_buf[CMSG_SPACE(sizeof(int))]; + + iov.iov_base = buf; + iov.iov_len = 1; + msg.msg_iov = &iov; + msg.msg_iovlen = 1; + msg.msg_control = cmsg_buf; + msg.msg_controllen = sizeof(cmsg_buf); + + ssize_t n = recvmsg(ipc_sockets[0], &msg, 0); + close(ipc_sockets[0]); + ASSERT_EQ(n, 1); + + struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg); + ASSERT_NE(cmsg, NULL); + memcpy(&sock_fd, CMSG_DATA(cmsg), sizeof(int)); + + /* Wait for child to exit */ + waitpid(pid, &status, 0); + ASSERT_TRUE(WIFEXITED(status)); + if (WEXITSTATUS(status) != 0) { + free(handle); + SKIP(close(sock_fd); return, "Child failed to create namespace"); + } + + /* Get network namespace from socket */ + netns_fd = ioctl(sock_fd, SIOCGSKNS); + if (netns_fd < 0) { + free(handle); + close(sock_fd); + if (errno == ENOTTY || errno == EINVAL) + SKIP(return, "SIOCGSKNS not supported"); + ASSERT_GE(netns_fd, 0); + } + + ASSERT_EQ(fstat(netns_fd, &st), 0); + netns_ino = st.st_ino; + + /* Get namespace ID */ + ret = ioctl(netns_fd, NS_GET_ID, &netns_id); + if (ret < 0) { + free(handle); + close(sock_fd); + close(netns_fd); + if (errno == ENOTTY || errno == EINVAL) + SKIP(return, "NS_GET_ID not supported"); + ASSERT_EQ(ret, 0); + } + + /* Get owner user namespace */ + userns_fd = ioctl(netns_fd, NS_GET_USERNS); + if (userns_fd < 0) { + free(handle); + close(sock_fd); + close(netns_fd); + if (errno == ENOTTY || errno == EINVAL) + SKIP(return, "NS_GET_USERNS not supported"); + ASSERT_GE(userns_fd, 0); + } + + /* Get owner namespace ID */ + ret = ioctl(userns_fd, NS_GET_ID, &userns_id); + if (ret < 0) { + close(userns_fd); + free(handle); + close(sock_fd); + close(netns_fd); + ASSERT_EQ(ret, 0); + } + close(userns_fd); + + TH_LOG("Testing netns %lu (id=%llu) owned by userns id=%llu", netns_ino, netns_id, userns_id); + + /* Verify namespace appears in listns() */ + ret = sys_listns(&req, ns_ids, ARRAY_SIZE(ns_ids), 0); + if (ret < 0) { + free(handle); + close(sock_fd); + close(netns_fd); + if (errno == ENOSYS) + SKIP(return, "listns() not supported"); + TH_LOG("listns failed: %s", strerror(errno)); + ASSERT_GE(ret, 0); + } + + found_netns = false; + found_userns = false; + for (i = 0; i < ret; i++) { + if (ns_ids[i] == netns_id) + found_netns = true; + if (ns_ids[i] == userns_id) + found_userns = true; + } + ASSERT_TRUE(found_netns); + ASSERT_TRUE(found_userns); + TH_LOG("Found netns %llu in listns() output", netns_id); + + /* Construct file handle from namespace ID */ + nsfs_fh = (struct nsfs_file_handle *)handle->f_handle; + nsfs_fh->ns_id = netns_id; + nsfs_fh->ns_type = 0; + nsfs_fh->ns_inum = 0; + + reopened_fd = open_by_handle_at(FD_NSFS_ROOT, handle, O_RDONLY); + if (reopened_fd < 0) { + free(handle); + close(sock_fd); + if (errno == EOPNOTSUPP || errno == ENOSYS || errno == EBADF) + SKIP(return, "open_by_handle_at with FD_NSFS_ROOT not supported"); + TH_LOG("open_by_handle_at failed: %s", strerror(errno)); + ASSERT_GE(reopened_fd, 0); + } + + struct stat reopened_st; + ASSERT_EQ(fstat(reopened_fd, &reopened_st), 0); + ASSERT_EQ(reopened_st.st_ino, netns_ino); + + TH_LOG("Successfully reopened netns %lu via file handle (socket-kept)", netns_ino); + + close(reopened_fd); + close(netns_fd); + + /* Try to reopen via file handle - should fail since namespace is now inactive */ + reopened_fd = open_by_handle_at(FD_NSFS_ROOT, handle, O_RDONLY); + if (reopened_fd >= 0) { + /* This might succeed if there's still a reference somewhere */ + TH_LOG("Warning: reopened netns after socket closed (fd=%d)", reopened_fd); + close(reopened_fd); + } else { + TH_LOG("Correctly failed to reopen inactive netns: %s", strerror(errno)); + } + + /* Get network namespace from socket */ + netns_fd = ioctl(sock_fd, SIOCGSKNS); + if (netns_fd < 0) { + free(handle); + close(sock_fd); + if (errno == ENOTTY || errno == EINVAL) + SKIP(return, "SIOCGSKNS not supported"); + ASSERT_GE(netns_fd, 0); + } + + /* Verify namespace appears in listns() */ + ret = sys_listns(&req, ns_ids, ARRAY_SIZE(ns_ids), 0); + if (ret < 0) { + free(handle); + close(sock_fd); + close(netns_fd); + if (errno == ENOSYS) + SKIP(return, "listns() not supported"); + TH_LOG("listns failed: %s", strerror(errno)); + ASSERT_GE(ret, 0); + } + + found_netns = false; + found_userns = false; + for (i = 0; i < ret; i++) { + if (ns_ids[i] == netns_id) + found_netns = true; + if (ns_ids[i] == userns_id) + found_userns = true; + } + ASSERT_TRUE(found_netns); + ASSERT_TRUE(found_userns); + TH_LOG("Found netns %llu in listns() output", netns_id); + + close(netns_fd); + + /* Verify namespace appears in listns() */ + ret = sys_listns(&req, ns_ids, ARRAY_SIZE(ns_ids), 0); + if (ret < 0) { + free(handle); + close(sock_fd); + close(netns_fd); + if (errno == ENOSYS) + SKIP(return, "listns() not supported"); + TH_LOG("listns failed: %s", strerror(errno)); + ASSERT_GE(ret, 0); + } + + found_netns = false; + found_userns = false; + for (i = 0; i < ret; i++) { + if (ns_ids[i] == netns_id) + found_netns = true; + if (ns_ids[i] == userns_id) + found_userns = true; + } + ASSERT_FALSE(found_netns); + ASSERT_FALSE(found_userns); + TH_LOG("Netns %llu correctly disappeared from listns() after socket closed", netns_id); + + close(sock_fd); + free(handle); +} + TEST_HARNESS_MAIN -- 2.47.3