+static int link_set_mtu(Link *link, uint32_t mtu) {
+ _cleanup_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_new_link(link->manager->rtnl, &req,
+ RTM_SETLINK, link->ifindex);
+ 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;
+}
+
+static int dhcp_lease_lost(Link *link) {
+ _cleanup_address_free_ Address *address = NULL;
+ struct in_addr addr;
+ struct in_addr netmask;
+ unsigned prefixlen;
+ int r;
+
+ assert(link);
+ assert(link->dhcp_lease);
+
+ log_warning_link(link, "DHCP lease lost");
+
+ r = address_new_dynamic(&address);
+ if (r >= 0) {
+ sd_dhcp_lease_get_address(link->dhcp_lease, &addr);
+ sd_dhcp_lease_get_netmask(link->dhcp_lease, &netmask);
+ prefixlen = net_netmask_to_prefixlen(&netmask);
+
+ address->family = AF_INET;
+ address->in_addr.in = addr;
+ address->prefixlen = prefixlen;
+
+ address_drop(address, link, &address_drop_handler);
+ }
+
+ if (link->network->dhcp_mtu) {
+ uint16_t mtu;
+
+ r = sd_dhcp_lease_get_mtu(link->dhcp_lease, &mtu);
+ if (r >= 0 && link->original_mtu != mtu) {
+ r = link_set_mtu(link, link->original_mtu);
+ if (r < 0) {
+ log_warning_link(link, "DHCP error: could not reset MTU");
+ link_enter_failed(link);
+ return r;
+ }
+ }
+ }
+
+ if (link->network->dhcp_hostname) {
+ const char *hostname = NULL;
+
+ r = sd_dhcp_lease_get_hostname(link->dhcp_lease, &hostname);
+ if (r >= 0 && hostname) {
+ r = set_hostname(link->manager->bus, "");
+ if (r < 0)
+ log_error("Failed to reset transient hostname");
+ }
+ }
+
+ link->dhcp_lease = sd_dhcp_lease_unref(link->dhcp_lease);
+
+ return 0;
+}
+
+static int dhcp_lease_acquired(sd_dhcp_client *client, Link *link) {
+ sd_dhcp_lease *lease;
+ struct in_addr address;
+ struct in_addr netmask;
+ struct in_addr gateway;
+ unsigned prefixlen;
+ struct in_addr *nameservers;
+ size_t nameservers_size;
+ int r;
+
+ assert(client);
+ assert(link);
+
+ r = sd_dhcp_client_get_lease(client, &lease);
+ if (r < 0) {
+ log_warning_link(link, "DHCP error: no lease: %s",
+ strerror(-r));
+ return r;
+ }
+
+ r = sd_dhcp_lease_get_address(lease, &address);
+ if (r < 0) {
+ log_warning_link(link, "DHCP error: no address: %s",
+ strerror(-r));
+ return r;
+ }
+
+ r = sd_dhcp_lease_get_netmask(lease, &netmask);
+ if (r < 0) {
+ log_warning_link(link, "DHCP error: no netmask: %s",
+ strerror(-r));
+ return r;
+ }
+
+ prefixlen = net_netmask_to_prefixlen(&netmask);
+
+ r = sd_dhcp_lease_get_router(lease, &gateway);
+ if (r < 0) {
+ log_warning_link(link, "DHCP error: no router: %s",
+ strerror(-r));
+ return r;
+ }
+
+ log_struct_link(LOG_INFO, link,
+ "MESSAGE=%s: DHCPv4 address %u.%u.%u.%u/%u via %u.%u.%u.%u",
+ link->ifname,
+ ADDRESS_FMT_VAL(address),
+ prefixlen,
+ ADDRESS_FMT_VAL(gateway),
+ "ADDRESS=%u.%u.%u.%u",
+ ADDRESS_FMT_VAL(address),
+ "PREFIXLEN=%u",
+ prefixlen,
+ "GATEWAY=%u.%u.%u.%u",
+ ADDRESS_FMT_VAL(gateway),
+ NULL);
+
+ link->dhcp_lease = lease;
+
+ if (link->network->dhcp_dns) {
+ r = sd_dhcp_lease_get_dns(lease, &nameservers, &nameservers_size);
+ if (r >= 0) {
+ r = manager_update_resolv_conf(link->manager);
+ if (r < 0)
+ log_error("Failed to update resolv.conf");
+ }
+ }
+
+ if (link->network->dhcp_mtu) {
+ uint16_t mtu;
+
+ r = sd_dhcp_lease_get_mtu(lease, &mtu);
+ if (r >= 0) {
+ r = link_set_mtu(link, mtu);
+ if (r < 0)
+ log_error_link(link, "Failed to set MTU "
+ "to %" PRIu16, mtu);
+ }
+ }
+
+ if (link->network->dhcp_hostname) {
+ const char *hostname;
+
+ r = sd_dhcp_lease_get_hostname(lease, &hostname);
+ if (r >= 0) {
+ r = set_hostname(link->manager->bus, hostname);
+ if (r < 0)
+ log_error("Failed to set transient hostname "
+ "to '%s'", hostname);
+ }
+ }
+
+ link_enter_set_addresses(link);
+
+ return 0;
+}
+
+static void dhcp_handler(sd_dhcp_client *client, int event, void *userdata) {
+ Link *link = userdata;