2 This file is part of systemd.
4 Copyright (C) 2013 Intel Corporation. All rights reserved.
6 systemd is free software; you can redistribute it and/or modify it
7 under the terms of the GNU Lesser General Public License as published by
8 the Free Software Foundation; either version 2.1 of the License, or
9 (at your option) any later version.
11 systemd is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public License
17 along with systemd; If not, see <http://www.gnu.org/licenses/>.
24 #include <net/ethernet.h>
25 #include <net/if_arp.h>
26 #include <sys/param.h>
27 #include <sys/ioctl.h>
32 #include "dhcp-protocol.h"
33 #include "dhcp-internal.h"
34 #include "dhcp-lease-internal.h"
35 #include "sd-dhcp-client.h"
37 struct sd_dhcp_client {
41 sd_event_source *timeout_resend;
44 union sockaddr_union link;
45 sd_event_source *receive_message;
47 size_t req_opts_allocated;
52 struct ether_addr mac_addr;
59 sd_event_source *timeout_t1;
60 sd_event_source *timeout_t2;
61 sd_event_source *timeout_expire;
62 sd_dhcp_client_cb_t cb;
67 static const uint8_t default_req_opts[] = {
68 DHCP_OPTION_SUBNET_MASK,
70 DHCP_OPTION_HOST_NAME,
71 DHCP_OPTION_DOMAIN_NAME,
72 DHCP_OPTION_DOMAIN_NAME_SERVER,
73 DHCP_OPTION_NTP_SERVER,
76 static int client_receive_message_raw(sd_event_source *s, int fd,
77 uint32_t revents, void *userdata);
78 static int client_receive_message_udp(sd_event_source *s, int fd,
79 uint32_t revents, void *userdata);
81 int sd_dhcp_client_set_callback(sd_dhcp_client *client, sd_dhcp_client_cb_t cb,
83 assert_return(client, -EINVAL);
86 client->userdata = userdata;
91 int sd_dhcp_client_set_request_option(sd_dhcp_client *client, uint8_t option) {
94 assert_return(client, -EINVAL);
95 assert_return (client->state == DHCP_STATE_INIT, -EBUSY);
99 case DHCP_OPTION_OVERLOAD:
100 case DHCP_OPTION_MESSAGE_TYPE:
101 case DHCP_OPTION_PARAMETER_REQUEST_LIST:
102 case DHCP_OPTION_END:
109 for (i = 0; i < client->req_opts_size; i++)
110 if (client->req_opts[i] == option)
113 if (!GREEDY_REALLOC(client->req_opts, client->req_opts_allocated,
114 client->req_opts_size + 1))
117 client->req_opts[client->req_opts_size++] = option;
122 int sd_dhcp_client_set_request_address(sd_dhcp_client *client,
123 const struct in_addr *last_addr) {
124 assert_return(client, -EINVAL);
125 assert_return(client->state == DHCP_STATE_INIT, -EBUSY);
128 client->last_addr = last_addr->s_addr;
130 client->last_addr = INADDR_ANY;
135 int sd_dhcp_client_set_index(sd_dhcp_client *client, int interface_index) {
136 assert_return(client, -EINVAL);
137 assert_return(client->state == DHCP_STATE_INIT, -EBUSY);
138 assert_return(interface_index >= -1, -EINVAL);
140 client->index = interface_index;
145 int sd_dhcp_client_set_mac(sd_dhcp_client *client,
146 const struct ether_addr *addr) {
147 bool need_restart = false;
149 assert_return(client, -EINVAL);
150 assert_return(addr, -EINVAL);
152 if (memcmp(&client->client_id.mac_addr, addr, ETH_ALEN) == 0)
155 if (client->state != DHCP_STATE_INIT) {
156 log_dhcp_client(client, "Changing MAC address on running DHCP "
157 "client, restarting");
158 sd_dhcp_client_stop(client);
162 memcpy(&client->client_id.mac_addr, addr, ETH_ALEN);
163 client->client_id.type = 0x01;
166 sd_dhcp_client_start(client);
171 int sd_dhcp_client_get_lease(sd_dhcp_client *client, sd_dhcp_lease **ret) {
172 assert_return(client, -EINVAL);
173 assert_return(ret, -EINVAL);
175 if (client->state != DHCP_STATE_BOUND &&
176 client->state != DHCP_STATE_RENEWING &&
177 client->state != DHCP_STATE_REBINDING)
178 return -EADDRNOTAVAIL;
180 *ret = sd_dhcp_lease_ref(client->lease);
185 static int client_notify(sd_dhcp_client *client, int event) {
187 client->cb(client, event, client->userdata);
192 static int client_initialize(sd_dhcp_client *client) {
193 assert_return(client, -EINVAL);
195 client->receive_message =
196 sd_event_source_unref(client->receive_message);
198 client->fd = safe_close(client->fd);
200 client->timeout_resend = sd_event_source_unref(client->timeout_resend);
202 client->timeout_t1 = sd_event_source_unref(client->timeout_t1);
203 client->timeout_t2 = sd_event_source_unref(client->timeout_t2);
204 client->timeout_expire = sd_event_source_unref(client->timeout_expire);
208 client->state = DHCP_STATE_INIT;
212 client->lease = sd_dhcp_lease_unref(client->lease);
217 static int client_stop(sd_dhcp_client *client, int error) {
218 assert_return(client, -EINVAL);
220 client_notify(client, error);
222 client_initialize(client);
224 log_dhcp_client(client, "STOPPED");
229 static int client_message_init(sd_dhcp_client *client, DHCPMessage *message,
230 uint8_t type, uint8_t **opt, size_t *optlen) {
234 assert(client->secs);
239 r = dhcp_message_init(message, BOOTREQUEST, client->xid, type, opt,
244 /* Although 'secs' field is a SHOULD in RFC 2131, certain DHCP servers
245 refuse to issue an DHCP lease if 'secs' is set to zero */
246 message->secs = htobe16(client->secs);
248 memcpy(&message->chaddr, &client->client_id.mac_addr, ETH_ALEN);
250 if (client->state == DHCP_STATE_RENEWING ||
251 client->state == DHCP_STATE_REBINDING)
252 message->ciaddr = client->lease->address;
254 /* Some DHCP servers will refuse to issue an DHCP lease if the Client
255 Identifier option is not set */
256 r = dhcp_option_append(opt, optlen, DHCP_OPTION_CLIENT_IDENTIFIER,
257 sizeof(client->client_id), &client->client_id);
261 if (type == DHCP_DISCOVER || type == DHCP_REQUEST) {
264 r = dhcp_option_append(opt, optlen,
265 DHCP_OPTION_PARAMETER_REQUEST_LIST,
266 client->req_opts_size,
271 /* Some DHCP servers will send bigger DHCP packets than the
272 defined default size unless the Maximum Messge Size option
273 is explicitely set */
274 max_size = htobe16(DHCP_IP_UDP_SIZE + DHCP_MESSAGE_SIZE +
275 DHCP_MIN_OPTIONS_SIZE);
276 r = dhcp_option_append(opt, optlen,
277 DHCP_OPTION_MAXIMUM_MESSAGE_SIZE,
286 static int dhcp_client_send_raw(sd_dhcp_client *client, DHCPPacket *packet,
288 dhcp_packet_append_ip_headers(packet, INADDR_ANY, DHCP_PORT_CLIENT,
289 INADDR_BROADCAST, DHCP_PORT_SERVER, len);
291 return dhcp_network_send_raw_socket(client->fd, &client->link,
295 static int client_send_discover(sd_dhcp_client *client) {
296 _cleanup_free_ DHCPPacket *discover = NULL;
304 r = sd_event_now(client->event, CLOCK_MONOTONIC, &time_now);
307 assert(time_now >= client->start_time);
309 /* seconds between sending first and last DISCOVER
310 * must always be strictly positive to deal with broken servers */
311 client->secs = ((time_now - client->start_time) / USEC_PER_SEC) ? : 1;
313 optlen = DHCP_MIN_OPTIONS_SIZE;
314 len = sizeof(DHCPPacket) + optlen;
316 discover = malloc0(len);
320 r = client_message_init(client, &discover->dhcp, DHCP_DISCOVER,
325 if (client->last_addr != INADDR_ANY) {
326 r = dhcp_option_append(&opt, &optlen,
327 DHCP_OPTION_REQUESTED_IP_ADDRESS,
328 4, &client->last_addr);
333 r = dhcp_option_append(&opt, &optlen, DHCP_OPTION_END, 0, NULL);
337 r = dhcp_client_send_raw(client, discover, len - optlen);
341 log_dhcp_client(client, "DISCOVER");
346 static int client_send_request(sd_dhcp_client *client) {
347 _cleanup_free_ DHCPPacket *request;
352 optlen = DHCP_MIN_OPTIONS_SIZE;
353 len = sizeof(DHCPPacket) + optlen;
355 request = malloc0(len);
359 r = client_message_init(client, &request->dhcp, DHCP_REQUEST, &opt,
364 switch (client->state) {
366 case DHCP_STATE_INIT_REBOOT:
367 r = dhcp_option_append(&opt, &optlen,
368 DHCP_OPTION_REQUESTED_IP_ADDRESS,
369 4, &client->last_addr);
374 case DHCP_STATE_REQUESTING:
375 r = dhcp_option_append(&opt, &optlen,
376 DHCP_OPTION_REQUESTED_IP_ADDRESS,
377 4, &client->lease->address);
381 r = dhcp_option_append(&opt, &optlen,
382 DHCP_OPTION_SERVER_IDENTIFIER,
383 4, &client->lease->server_address);
388 case DHCP_STATE_INIT:
389 case DHCP_STATE_SELECTING:
390 case DHCP_STATE_REBOOTING:
391 case DHCP_STATE_BOUND:
392 case DHCP_STATE_RENEWING:
393 case DHCP_STATE_REBINDING:
398 r = dhcp_option_append(&opt, &optlen, DHCP_OPTION_END, 0, NULL);
402 if (client->state == DHCP_STATE_RENEWING) {
403 r = dhcp_network_send_udp_socket(client->fd,
404 client->lease->server_address,
407 len - optlen - DHCP_IP_UDP_SIZE);
409 r = dhcp_client_send_raw(client, request, len - optlen);
414 log_dhcp_client(client, "REQUEST");
419 static int client_timeout_resend(sd_event_source *s, uint64_t usec,
421 sd_dhcp_client *client = userdata;
422 usec_t next_timeout = 0;
429 assert(client->event);
431 r = sd_event_now(client->event, CLOCK_MONOTONIC, &time_now);
435 switch (client->state) {
436 case DHCP_STATE_RENEWING:
438 time_left = (client->lease->t2 - client->lease->t1) / 2;
442 next_timeout = time_now + time_left * USEC_PER_SEC;
446 case DHCP_STATE_REBINDING:
448 time_left = (client->lease->lifetime - client->lease->t2) / 2;
452 next_timeout = time_now + time_left * USEC_PER_SEC;
455 case DHCP_STATE_REBOOTING:
456 /* start over as we did not receive a timely ack or nak */
457 client->state = DHCP_STATE_INIT;
459 client->xid = random_u32();
462 case DHCP_STATE_INIT:
463 case DHCP_STATE_INIT_REBOOT:
464 case DHCP_STATE_SELECTING:
465 case DHCP_STATE_REQUESTING:
466 case DHCP_STATE_BOUND:
468 if (client->attempt < 64)
469 client->attempt *= 2;
471 next_timeout = time_now + (client->attempt - 1) * USEC_PER_SEC;
476 next_timeout += (random_u32() & 0x1fffff);
478 client->timeout_resend = sd_event_source_unref(client->timeout_resend);
480 r = sd_event_add_time(client->event,
481 &client->timeout_resend,
483 next_timeout, 10 * USEC_PER_MSEC,
484 client_timeout_resend, client);
488 r = sd_event_source_set_priority(client->timeout_resend,
489 client->event_priority);
493 switch (client->state) {
494 case DHCP_STATE_INIT:
495 r = client_send_discover(client);
497 client->state = DHCP_STATE_SELECTING;
500 if (client->attempt >= 64)
506 case DHCP_STATE_SELECTING:
507 r = client_send_discover(client);
508 if (r < 0 && client->attempt >= 64)
513 case DHCP_STATE_INIT_REBOOT:
514 case DHCP_STATE_REQUESTING:
515 case DHCP_STATE_RENEWING:
516 case DHCP_STATE_REBINDING:
517 r = client_send_request(client);
518 if (r < 0 && client->attempt >= 64)
521 if (client->state == DHCP_STATE_INIT_REBOOT)
522 client->state = DHCP_STATE_REBOOTING;
524 client->request_sent = time_now;
528 case DHCP_STATE_REBOOTING:
529 case DHCP_STATE_BOUND:
537 client_stop(client, r);
539 /* Errors were dealt with when stopping the client, don't spill
540 errors into the event loop handler */
544 static int client_initialize_events(sd_dhcp_client *client,
545 sd_event_io_handler_t io_callback) {
549 assert(client->event);
551 r = sd_event_add_io(client->event, &client->receive_message,
552 client->fd, EPOLLIN, io_callback,
557 r = sd_event_source_set_priority(client->receive_message,
558 client->event_priority);
562 client->timeout_resend = sd_event_source_unref(client->timeout_resend);
564 r = sd_event_add_time(client->event,
565 &client->timeout_resend,
568 client_timeout_resend, client);
572 r = sd_event_source_set_priority(client->timeout_resend,
573 client->event_priority);
577 client_stop(client, r);
583 static int client_start(sd_dhcp_client *client) {
586 assert_return(client, -EINVAL);
587 assert_return(client->event, -EINVAL);
588 assert_return(client->index > 0, -EINVAL);
589 assert_return(client->fd < 0, -EBUSY);
590 assert_return(client->xid == 0, -EINVAL);
591 assert_return(client->state == DHCP_STATE_INIT ||
592 client->state == DHCP_STATE_INIT_REBOOT, -EBUSY);
594 client->xid = random_u32();
596 r = dhcp_network_bind_raw_socket(client->index, &client->link, client->xid);
599 client_stop(client, r);
604 if (client->state == DHCP_STATE_INIT) {
605 client->start_time = now(CLOCK_MONOTONIC);
609 log_dhcp_client(client, "STARTED");
611 return client_initialize_events(client, client_receive_message_raw);
614 static int client_timeout_expire(sd_event_source *s, uint64_t usec,
616 sd_dhcp_client *client = userdata;
618 log_dhcp_client(client, "EXPIRED");
620 client_notify(client, DHCP_EVENT_EXPIRED);
622 /* start over as the lease was lost */
623 client_initialize(client);
624 client_start(client);
629 static int client_timeout_t2(sd_event_source *s, uint64_t usec, void *userdata) {
630 sd_dhcp_client *client = userdata;
633 client->receive_message = sd_event_source_unref(client->receive_message);
634 client->fd = safe_close(client->fd);
636 client->state = DHCP_STATE_REBINDING;
639 r = dhcp_network_bind_raw_socket(client->index, &client->link, client->xid);
641 client_stop(client, r);
647 log_dhcp_client(client, "TIMEOUT T2");
649 return client_initialize_events(client, client_receive_message_raw);
652 static int client_timeout_t1(sd_event_source *s, uint64_t usec,
654 sd_dhcp_client *client = userdata;
657 client->state = DHCP_STATE_RENEWING;
660 r = dhcp_network_bind_udp_socket(client->index,
661 client->lease->address,
664 client_stop(client, r);
670 log_dhcp_client(client, "TIMEOUT T1");
672 return client_initialize_events(client, client_receive_message_udp);
675 static int client_handle_offer(sd_dhcp_client *client, DHCPMessage *offer,
677 _cleanup_dhcp_lease_unref_ sd_dhcp_lease *lease = NULL;
680 r = dhcp_lease_new(&lease);
684 r = dhcp_option_parse(offer, len, dhcp_lease_parse_options, lease);
685 if (r != DHCP_OFFER) {
686 log_dhcp_client(client, "receieved message was not an OFFER, ignoring");
690 lease->next_server = offer->siaddr;
692 lease->address = offer->yiaddr;
694 if (lease->address == INADDR_ANY ||
695 lease->server_address == INADDR_ANY ||
696 lease->lifetime == 0) {
697 log_dhcp_client(client, "receieved lease lacks address, server "
698 "address or lease lifetime, ignoring");
702 if (lease->subnet_mask == INADDR_ANY) {
703 r = dhcp_lease_set_default_subnet_mask(lease);
705 log_dhcp_client(client, "receieved lease lacks subnet "
706 "mask, and a fallback one can not be "
707 "generated, ignoring");
712 client->lease = lease;
715 log_dhcp_client(client, "OFFER");
720 static int client_handle_ack(sd_dhcp_client *client, DHCPMessage *ack,
722 _cleanup_dhcp_lease_unref_ sd_dhcp_lease *lease = NULL;
725 r = dhcp_lease_new(&lease);
729 r = dhcp_option_parse(ack, len, dhcp_lease_parse_options, lease);
731 log_dhcp_client(client, "NAK");
732 return DHCP_EVENT_NO_LEASE;
736 log_dhcp_client(client, "receieved message was not an ACK, ignoring");
740 lease->next_server = ack->siaddr;
742 lease->address = ack->yiaddr;
744 if (lease->address == INADDR_ANY ||
745 lease->server_address == INADDR_ANY ||
746 lease->lifetime == 0) {
747 log_dhcp_client(client, "receieved lease lacks address, server "
748 "address or lease lifetime, ignoring");
752 if (lease->subnet_mask == INADDR_ANY) {
753 r = dhcp_lease_set_default_subnet_mask(lease);
755 log_dhcp_client(client, "receieved lease lacks subnet "
756 "mask, and a fallback one can not be "
757 "generated, ignoring");
762 r = DHCP_EVENT_IP_ACQUIRE;
764 if (client->lease->address != lease->address ||
765 client->lease->subnet_mask != lease->subnet_mask ||
766 client->lease->router != lease->router) {
767 r = DHCP_EVENT_IP_CHANGE;
770 client->lease = sd_dhcp_lease_unref(client->lease);
773 client->lease = lease;
776 log_dhcp_client(client, "ACK");
781 static uint64_t client_compute_timeout(sd_dhcp_client *client,
782 uint32_t lifetime, double factor) {
784 assert(client->request_sent);
787 return client->request_sent + ((lifetime - 3) * USEC_PER_SEC * factor) +
788 + (random_u32() & 0x1fffff);
791 static int client_set_lease_timeouts(sd_dhcp_client *client) {
793 uint64_t lifetime_timeout;
796 char time_string[FORMAT_TIMESPAN_MAX];
800 assert(client->event);
801 assert(client->lease);
802 assert(client->lease->lifetime);
804 client->timeout_t1 = sd_event_source_unref(client->timeout_t1);
805 client->timeout_t2 = sd_event_source_unref(client->timeout_t2);
806 client->timeout_expire = sd_event_source_unref(client->timeout_expire);
808 /* don't set timers for infinite leases */
809 if (client->lease->lifetime == 0xffffffff)
812 r = sd_event_now(client->event, CLOCK_MONOTONIC, &time_now);
815 assert(client->request_sent <= time_now);
817 /* convert the various timeouts from relative (secs) to absolute (usecs) */
818 lifetime_timeout = client_compute_timeout(client, client->lease->lifetime, 1);
819 if (client->lease->t1 && client->lease->t2) {
820 /* both T1 and T2 are given */
821 if (client->lease->t1 < client->lease->t2 &&
822 client->lease->t2 < client->lease->lifetime) {
823 /* they are both valid */
824 t2_timeout = client_compute_timeout(client, client->lease->t2, 1);
825 t1_timeout = client_compute_timeout(client, client->lease->t1, 1);
828 t2_timeout = client_compute_timeout(client, client->lease->lifetime, 7.0 / 8.0);
829 client->lease->t2 = (client->lease->lifetime * 7) / 8;
830 t1_timeout = client_compute_timeout(client, client->lease->lifetime, 0.5);
831 client->lease->t1 = client->lease->lifetime / 2;
833 } else if (client->lease->t2 && client->lease->t2 < client->lease->lifetime) {
834 /* only T2 is given, and it is valid */
835 t2_timeout = client_compute_timeout(client, client->lease->t2, 1);
836 t1_timeout = client_compute_timeout(client, client->lease->lifetime, 0.5);
837 client->lease->t1 = client->lease->lifetime / 2;
838 if (t2_timeout <= t1_timeout) {
839 /* the computed T1 would be invalid, so discard T2 */
840 t2_timeout = client_compute_timeout(client, client->lease->lifetime, 7.0 / 8.0);
841 client->lease->t2 = (client->lease->lifetime * 7) / 8;
843 } else if (client->lease->t1 && client->lease->t1 < client->lease->lifetime) {
844 /* only T1 is given, and it is valid */
845 t1_timeout = client_compute_timeout(client, client->lease->t1, 1);
846 t2_timeout = client_compute_timeout(client, client->lease->lifetime, 7.0 / 8.0);
847 client->lease->t2 = (client->lease->lifetime * 7) / 8;
848 if (t2_timeout <= t1_timeout) {
849 /* the computed T2 would be invalid, so discard T1 */
850 t2_timeout = client_compute_timeout(client, client->lease->lifetime, 0.5);
851 client->lease->t2 = client->lease->lifetime / 2;
854 /* fall back to the default timeouts */
855 t1_timeout = client_compute_timeout(client, client->lease->lifetime, 0.5);
856 client->lease->t1 = client->lease->lifetime / 2;
857 t2_timeout = client_compute_timeout(client, client->lease->lifetime, 7.0 / 8.0);
858 client->lease->t2 = (client->lease->lifetime * 7) / 8;
861 /* arm lifetime timeout */
862 r = sd_event_add_time(client->event, &client->timeout_expire,
864 lifetime_timeout, 10 * USEC_PER_MSEC,
865 client_timeout_expire, client);
869 r = sd_event_source_set_priority(client->timeout_expire,
870 client->event_priority);
874 log_dhcp_client(client, "lease expires in %s",
875 format_timespan(time_string, FORMAT_TIMESPAN_MAX,
876 lifetime_timeout - time_now, 0));
878 /* don't arm earlier timeouts if this has already expired */
879 if (lifetime_timeout <= time_now)
883 r = sd_event_add_time(client->event,
888 client_timeout_t2, client);
892 r = sd_event_source_set_priority(client->timeout_t2,
893 client->event_priority);
897 log_dhcp_client(client, "T2 expires in %s",
898 format_timespan(time_string, FORMAT_TIMESPAN_MAX,
899 t2_timeout - time_now, 0));
901 /* don't arm earlier timeout if this has already expired */
902 if (t2_timeout <= time_now)
906 r = sd_event_add_time(client->event,
909 t1_timeout, 10 * USEC_PER_MSEC,
910 client_timeout_t1, client);
914 r = sd_event_source_set_priority(client->timeout_t1,
915 client->event_priority);
919 log_dhcp_client(client, "T1 expires in %s",
920 format_timespan(time_string, FORMAT_TIMESPAN_MAX,
921 t1_timeout - time_now, 0));
926 static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message,
928 int r = 0, notify_event = 0;
931 assert(client->event);
934 if (be32toh(message->magic) != DHCP_MAGIC_COOKIE) {
935 log_dhcp_client(client, "not a DHCP message: ignoring");
939 if (message->op != BOOTREPLY) {
940 log_dhcp_client(client, "not a BOOTREPLY message: ignoring");
944 if (be32toh(message->xid) != client->xid) {
945 log_dhcp_client(client, "received xid (%u) does not match "
946 "expected (%u): ignoring",
947 be32toh(message->xid), client->xid);
951 if (message->htype != ARPHRD_ETHER || message->hlen != ETHER_ADDR_LEN) {
952 log_dhcp_client(client, "not an ethernet packet");
956 if (memcmp(&message->chaddr[0], &client->client_id.mac_addr,
958 log_dhcp_client(client, "received chaddr does not match "
959 "expected: ignoring");
963 switch (client->state) {
964 case DHCP_STATE_SELECTING:
966 r = client_handle_offer(client, message, len);
969 client->timeout_resend =
970 sd_event_source_unref(client->timeout_resend);
972 client->state = DHCP_STATE_REQUESTING;
975 r = sd_event_add_time(client->event,
976 &client->timeout_resend,
979 client_timeout_resend, client);
983 r = sd_event_source_set_priority(client->timeout_resend,
984 client->event_priority);
987 } else if (r == -ENOMSG)
988 /* invalid message, let's ignore it */
993 case DHCP_STATE_REBOOTING:
994 case DHCP_STATE_REQUESTING:
995 case DHCP_STATE_RENEWING:
996 case DHCP_STATE_REBINDING:
998 r = client_handle_ack(client, message, len);
999 if (r == DHCP_EVENT_NO_LEASE) {
1001 client->timeout_resend =
1002 sd_event_source_unref(client->timeout_resend);
1004 if (client->state == DHCP_STATE_REBOOTING) {
1005 r = client_initialize(client);
1009 r = client_start(client);
1015 } else if (r >= 0) {
1016 client->timeout_resend =
1017 sd_event_source_unref(client->timeout_resend);
1019 if (IN_SET(client->state, DHCP_STATE_REQUESTING,
1020 DHCP_STATE_REBOOTING))
1021 notify_event = DHCP_EVENT_IP_ACQUIRE;
1022 else if (r != DHCP_EVENT_IP_ACQUIRE)
1025 client->state = DHCP_STATE_BOUND;
1026 client->attempt = 1;
1028 client->last_addr = client->lease->address;
1030 r = client_set_lease_timeouts(client);
1035 client_notify(client, notify_event);
1037 client->receive_message =
1038 sd_event_source_unref(client->receive_message);
1039 client->fd = safe_close(client->fd);
1040 } else if (r == -ENOMSG)
1041 /* invalid message, let's ignore it */
1046 case DHCP_STATE_INIT:
1047 case DHCP_STATE_INIT_REBOOT:
1048 case DHCP_STATE_BOUND:
1054 if (r < 0 || r == DHCP_EVENT_NO_LEASE)
1055 return client_stop(client, r);
1060 static int client_receive_message_udp(sd_event_source *s, int fd,
1061 uint32_t revents, void *userdata) {
1062 sd_dhcp_client *client = userdata;
1063 _cleanup_free_ DHCPMessage *message = NULL;
1064 int buflen = 0, len, r;
1069 r = ioctl(fd, FIONREAD, &buflen);
1070 if (r < 0 || buflen <= 0)
1071 buflen = sizeof(DHCPMessage) + DHCP_MIN_OPTIONS_SIZE;
1073 message = malloc0(buflen);
1077 len = read(fd, message, buflen);
1079 log_dhcp_client(client, "could not receive message from UDP "
1080 "socket: %s", strerror(errno));
1082 } else if ((size_t)len < sizeof(DHCPMessage))
1085 return client_handle_message(client, message, len);
1088 static int client_receive_message_raw(sd_event_source *s, int fd,
1089 uint32_t revents, void *userdata) {
1090 sd_dhcp_client *client = userdata;
1091 _cleanup_free_ DHCPPacket *packet = NULL;
1092 uint8_t cmsgbuf[CMSG_LEN(sizeof(struct tpacket_auxdata))];
1093 struct iovec iov = {};
1094 struct msghdr msg = {
1097 .msg_control = cmsgbuf,
1098 .msg_controllen = sizeof(cmsgbuf),
1100 struct cmsghdr *cmsg;
1101 bool checksum = true;
1102 int buflen = 0, len, r;
1107 r = ioctl(fd, FIONREAD, &buflen);
1108 if (r < 0 || buflen <= 0)
1109 buflen = sizeof(DHCPPacket) + DHCP_MIN_OPTIONS_SIZE;
1111 packet = malloc0(buflen);
1115 iov.iov_base = packet;
1116 iov.iov_len = buflen;
1118 len = recvmsg(fd, &msg, 0);
1120 log_dhcp_client(client, "could not receive message from raw "
1121 "socket: %s", strerror(errno));
1123 } else if ((size_t)len < sizeof(DHCPPacket))
1126 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
1127 if (cmsg->cmsg_level == SOL_PACKET && cmsg->cmsg_type == PACKET_AUXDATA) {
1128 struct tpacket_auxdata *aux = (void *)CMSG_DATA(cmsg);
1130 checksum = !(aux->tp_status & TP_STATUS_CSUMNOTREADY);
1135 r = dhcp_packet_verify_headers(packet, len, checksum);
1139 len -= DHCP_IP_UDP_SIZE;
1141 return client_handle_message(client, &packet->dhcp, len);
1144 int sd_dhcp_client_start(sd_dhcp_client *client) {
1147 assert_return(client, -EINVAL);
1149 r = client_initialize(client);
1153 if (client->last_addr)
1154 client->state = DHCP_STATE_INIT_REBOOT;
1156 return client_start(client);
1159 int sd_dhcp_client_stop(sd_dhcp_client *client) {
1160 return client_stop(client, DHCP_EVENT_STOP);
1163 int sd_dhcp_client_attach_event(sd_dhcp_client *client, sd_event *event,
1167 assert_return(client, -EINVAL);
1168 assert_return(!client->event, -EBUSY);
1171 client->event = sd_event_ref(event);
1173 r = sd_event_default(&client->event);
1178 client->event_priority = priority;
1183 int sd_dhcp_client_detach_event(sd_dhcp_client *client) {
1184 assert_return(client, -EINVAL);
1186 client->event = sd_event_unref(client->event);
1191 sd_event *sd_dhcp_client_get_event(sd_dhcp_client *client) {
1195 return client->event;
1198 void sd_dhcp_client_free(sd_dhcp_client *client) {
1202 sd_dhcp_client_stop(client);
1203 sd_dhcp_client_detach_event(client);
1205 free(client->req_opts);
1209 DEFINE_TRIVIAL_CLEANUP_FUNC(sd_dhcp_client*, sd_dhcp_client_free);
1210 #define _cleanup_dhcp_client_free_ _cleanup_(sd_dhcp_client_freep)
1212 int sd_dhcp_client_new(sd_dhcp_client **ret) {
1213 _cleanup_dhcp_client_free_ sd_dhcp_client *client = NULL;
1215 assert_return(ret, -EINVAL);
1217 client = new0(sd_dhcp_client, 1);
1221 client->state = DHCP_STATE_INIT;
1224 client->attempt = 1;
1226 client->req_opts_size = ELEMENTSOF(default_req_opts);
1228 client->req_opts = memdup(default_req_opts, client->req_opts_size);
1229 if (!client->req_opts)