+static int setup_veth(pid_t pid, char iface_name[]) {
+ _cleanup_rtnl_message_unref_ sd_rtnl_message *m = NULL;
+ _cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL;
+ int r;
+
+ if (!arg_private_network)
+ return 0;
+
+ if (!arg_network_veth)
+ return 0;
+
+ strncpy(iface_name+3, arg_machine, IFNAMSIZ - 3);
+
+ r = sd_rtnl_open(0, &rtnl);
+ if (r < 0) {
+ log_error("Failed to connect to netlink: %s", strerror(-r));
+ return r;
+ }
+
+ r = sd_rtnl_message_new_link(RTM_NEWLINK, 0, &m);
+ if (r < 0) {
+ log_error("Failed to allocate netlink message: %s", strerror(-r));
+ return r;
+ }
+
+ r = sd_rtnl_message_append_string(m, IFLA_IFNAME, iface_name);
+ if (r < 0) {
+ log_error("Failed to add netlink interface name: %s", strerror(-r));
+ return r;
+ }
+
+ r = sd_rtnl_message_open_container(m, IFLA_LINKINFO);
+ if (r < 0) {
+ log_error("Failed to open netlink container: %s", strerror(-r));
+ return r;
+ }
+
+ r = sd_rtnl_message_append_string(m, IFLA_INFO_KIND, "veth");
+ if (r < 0) {
+ log_error("Failed to append netlink kind: %s", strerror(-r));
+ return r;
+ }
+
+ r = sd_rtnl_message_open_container(m, IFLA_INFO_DATA);
+ if (r < 0) {
+ log_error("Failed to open netlink container: %s", strerror(-r));
+ return r;
+ }
+
+ r = sd_rtnl_message_open_container(m, VETH_INFO_PEER);
+ if (r < 0) {
+ log_error("Failed to open netlink container: %s", strerror(-r));
+ return r;
+ }
+
+ r = sd_rtnl_message_append_string(m, IFLA_IFNAME, "host0");
+ if (r < 0) {
+ log_error("Failed to add netlink interface name: %s", strerror(-r));
+ return r;
+ }
+
+ r = sd_rtnl_message_append_u32(m, IFLA_NET_NS_PID, pid);
+ if (r < 0) {
+ log_error("Failed to add netlink namespace field: %s", strerror(-r));
+ return r;
+ }
+
+ r = sd_rtnl_message_close_container(m);
+ if (r < 0) {
+ log_error("Failed to close netlink container: %s", strerror(-r));
+ return r;
+ }
+
+ r = sd_rtnl_message_close_container(m);
+ if (r < 0) {
+ log_error("Failed to close netlink container: %s", strerror(-r));
+ return r;
+ }
+
+ r = sd_rtnl_message_close_container(m);
+ if (r < 0) {
+ log_error("Failed to close netlink container: %s", strerror(-r));
+ return r;
+ }
+
+ r = sd_rtnl_call(rtnl, m, 0, NULL);
+ if (r < 0) {
+ log_error("Failed to add new veth interfaces: %s", strerror(-r));
+ return r;
+ }
+
+ return 0;
+}
+
+static int setup_bridge(const char veth_name[]) {
+ _cleanup_rtnl_message_unref_ sd_rtnl_message *m = NULL;
+ _cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL;
+ int r, bridge;
+
+ if (!arg_private_network)
+ return 0;
+
+ if (!arg_network_veth)
+ return 0;
+
+ if (!arg_network_bridge)
+ return 0;
+
+ bridge = (int) if_nametoindex(arg_network_bridge);
+ if (bridge <= 0) {
+ log_error("Failed to resolve interface %s: %m", arg_network_bridge);
+ return -errno;
+ }
+
+ r = sd_rtnl_open(0, &rtnl);
+ if (r < 0) {
+ log_error("Failed to connect to netlink: %s", strerror(-r));
+ return r;
+ }
+
+ r = sd_rtnl_message_new_link(RTM_SETLINK, 0, &m);
+ if (r < 0) {
+ log_error("Failed to allocate netlink message: %s", strerror(-r));
+ return r;
+ }
+
+ r = sd_rtnl_message_append_string(m, IFLA_IFNAME, veth_name);
+ if (r < 0) {
+ log_error("Failed to add netlink interface name field: %s", strerror(-r));
+ return r;
+ }
+
+ r = sd_rtnl_message_append_u32(m, IFLA_MASTER, bridge);
+ if (r < 0) {
+ log_error("Failed to add netlink master field: %s", strerror(-r));
+ return r;
+ }
+
+ r = sd_rtnl_call(rtnl, m, 0, NULL);
+ if (r < 0) {
+ log_error("Failed to add veth interface to bridge: %s", strerror(-r));
+ return r;
+ }
+
+ return 0;
+}
+