return 0;
}
-int move_network_interfaces(pid_t pid, char **ifaces) {
+int move_network_interfaces(int netns_fd, char **ifaces) {
_cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
char **i;
int r;
if (r < 0)
return log_error_errno(r, "Failed to allocate netlink message: %m");
- r = sd_netlink_message_append_u32(m, IFLA_NET_NS_PID, pid);
+ r = sd_netlink_message_append_u32(m, IFLA_NET_NS_FD, netns_fd);
if (r < 0)
- return log_error_errno(r, "Failed to append namespace PID to netlink message: %m");
+ return log_error_errno(r, "Failed to append namespace fd to netlink message: %m");
r = sd_netlink_call(rtnl, m, 0, NULL);
if (r < 0)
int ifi = 0, r;
ssize_t l;
sigset_t mask_chld;
- _cleanup_close_ int netns_fd = -1;
+ _cleanup_close_ int child_netns_fd = -1;
assert_se(sigemptyset(&mask_chld) == 0);
assert_se(sigaddset(&mask_chld, SIGCHLD) == 0);
return log_error_errno(errno, "Failed to install SIGCHLD handler: %m");
if (arg_network_namespace_path) {
- netns_fd = open(arg_network_namespace_path, O_RDONLY|O_NOCTTY|O_CLOEXEC);
- if (netns_fd < 0)
+ child_netns_fd = open(arg_network_namespace_path, O_RDONLY|O_NOCTTY|O_CLOEXEC);
+ if (child_netns_fd < 0)
return log_error_errno(errno, "Cannot open file %s: %m", arg_network_namespace_path);
- r = fd_is_network_ns(netns_fd);
+ r = fd_is_network_ns(child_netns_fd);
if (r == -EUCLEAN)
log_debug_errno(r, "Cannot determine if passed network namespace path '%s' really refers to a network namespace, assuming it does.", arg_network_namespace_path);
else if (r < 0)
master_pty_socket_pair[1],
unified_cgroup_hierarchy_socket_pair[1],
fds,
- netns_fd);
+ child_netns_fd);
if (r < 0)
_exit(EXIT_FAILURE);
return log_error_errno(SYNTHETIC_ERRNO(ESRCH), "Child died too early");
}
- r = move_network_interfaces(*pid, arg_network_interfaces);
+ if (child_netns_fd < 0) {
+ /* Make sure we have an open file descriptor to the child's network
+ * namespace so it stays alive even if the child exits. */
+ r = namespace_open(*pid, NULL, NULL, &child_netns_fd, NULL, NULL);
+ if (r < 0)
+ return log_error_errno(r, "Failed to open child network namespace: %m");
+ }
+
+ r = move_network_interfaces(child_netns_fd, arg_network_interfaces);
if (r < 0)
return r;
/* Normally redundant, but better safe than sorry */
(void) kill(*pid, SIGKILL);
+ if (arg_private_network) {
+ /* Move network interfaces back to the parent network namespace. We use `safe_fork`
+ * to avoid having to move the parent to the child network namespace. */
+ r = safe_fork(NULL, FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_WAIT|FORK_LOG, NULL);
+ if (r < 0)
+ return r;
+
+ if (r == 0) {
+ _cleanup_close_ int parent_netns_fd = -1;
+
+ r = namespace_open(getpid(), NULL, NULL, &parent_netns_fd, NULL, NULL);
+ if (r < 0) {
+ log_error_errno(r, "Failed to open parent network namespace: %m");
+ _exit(EXIT_FAILURE);
+ }
+
+ r = namespace_enter(-1, -1, child_netns_fd, -1, -1);
+ if (r < 0) {
+ log_error_errno(r, "Failed to enter child network namespace: %m");
+ _exit(EXIT_FAILURE);
+ }
+
+ r = move_network_interfaces(parent_netns_fd, arg_network_interfaces);
+ if (r < 0)
+ log_error_errno(r, "Failed to move network interfaces back to parent network namespace: %m");
+
+ _exit(r < 0 ? EXIT_FAILURE : EXIT_SUCCESS);
+ }
+ }
+
r = wait_for_container(*pid, &container_status);
*pid = 0;