+static int set_mtu_handler(sd_rtnl *rtnl, sd_rtnl_message *m, void *userdata) {
+ Link *link = userdata;
+ int r;
+
+ assert(m);
+ assert(link);
+ assert(link->ifname);
+
+ if (link->state == LINK_STATE_FAILED)
+ return 1;
+
+ r = sd_rtnl_message_get_errno(m);
+ if (r < 0 && r != -EEXIST)
+ log_warning_link(link, "Could not set MTU: %s", strerror(-r));
+
+ return 1;
+}
+
+static int link_set_mtu(Link *link, uint32_t mtu) {
+ _cleanup_sd_rtnl_message_unref_ sd_rtnl_message *req = NULL;
+ int r;
+
+ assert(link);
+ assert(link->manager);
+ assert(link->manager->rtnl);
+
+ log_debug_link(link, "setting MTU: %" PRIu32, mtu);
+
+ r = sd_rtnl_message_link_new(RTM_SETLINK, link->ifindex, &req);
+ if (r < 0) {
+ log_error_link(link, "Could not allocate RTM_SETLINK message");
+ return r;
+ }
+
+ r = sd_rtnl_message_append_u32(req, IFLA_MTU, mtu);
+ if (r < 0) {
+ log_error_link(link, "Could not append MTU: %s", strerror(-r));
+ return r;
+ }
+
+ r = sd_rtnl_call_async(link->manager->rtnl, req, set_mtu_handler, link, 0, NULL);
+ if (r < 0) {
+ log_error_link(link,
+ "Could not send rtnetlink message: %s", strerror(-r));
+ return r;
+ }
+
+ return 0;
+}
+