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 <sys/param.h>
26 #include <sys/ioctl.h>
31 #include "dhcp-protocol.h"
32 #include "dhcp-internal.h"
33 #include "dhcp-lease-internal.h"
34 #include "sd-dhcp-client.h"
36 struct sd_dhcp_client {
40 sd_event_source *timeout_resend;
43 union sockaddr_union link;
44 sd_event_source *receive_message;
46 size_t req_opts_allocated;
51 struct ether_addr mac_addr;
58 sd_event_source *timeout_t1;
59 sd_event_source *timeout_t2;
60 sd_event_source *timeout_expire;
61 sd_dhcp_client_cb_t cb;
66 static const uint8_t default_req_opts[] = {
67 DHCP_OPTION_SUBNET_MASK,
69 DHCP_OPTION_HOST_NAME,
70 DHCP_OPTION_DOMAIN_NAME,
71 DHCP_OPTION_DOMAIN_NAME_SERVER,
72 DHCP_OPTION_NTP_SERVER,
75 static int client_receive_message_raw(sd_event_source *s, int fd,
76 uint32_t revents, void *userdata);
77 static int client_receive_message_udp(sd_event_source *s, int fd,
78 uint32_t revents, void *userdata);
80 int sd_dhcp_client_set_callback(sd_dhcp_client *client, sd_dhcp_client_cb_t cb,
82 assert_return(client, -EINVAL);
85 client->userdata = userdata;
90 int sd_dhcp_client_set_request_option(sd_dhcp_client *client, uint8_t option) {
93 assert_return(client, -EINVAL);
94 assert_return (client->state == DHCP_STATE_INIT, -EBUSY);
98 case DHCP_OPTION_OVERLOAD:
99 case DHCP_OPTION_MESSAGE_TYPE:
100 case DHCP_OPTION_PARAMETER_REQUEST_LIST:
101 case DHCP_OPTION_END:
108 for (i = 0; i < client->req_opts_size; i++)
109 if (client->req_opts[i] == option)
112 if (!GREEDY_REALLOC(client->req_opts, client->req_opts_allocated,
113 client->req_opts_size + 1))
116 client->req_opts[client->req_opts_size++] = option;
121 int sd_dhcp_client_set_request_address(sd_dhcp_client *client,
122 const struct in_addr *last_addr) {
123 assert_return(client, -EINVAL);
124 assert_return(client->state == DHCP_STATE_INIT, -EBUSY);
127 client->last_addr = last_addr->s_addr;
129 client->last_addr = INADDR_ANY;
134 int sd_dhcp_client_set_index(sd_dhcp_client *client, int interface_index) {
135 assert_return(client, -EINVAL);
136 assert_return(client->state == DHCP_STATE_INIT, -EBUSY);
137 assert_return(interface_index >= -1, -EINVAL);
139 client->index = interface_index;
144 int sd_dhcp_client_set_mac(sd_dhcp_client *client,
145 const struct ether_addr *addr) {
146 assert_return(client, -EINVAL);
147 assert_return(client->state == DHCP_STATE_INIT, -EBUSY);
149 log_dhcp_client(client, "set MAC address to "
150 "%02hhx:%02hhx:%02hhx:%02hhx:%02hhx:%02hhx",
151 addr->ether_addr_octet[0],
152 addr->ether_addr_octet[1],
153 addr->ether_addr_octet[2],
154 addr->ether_addr_octet[3],
155 addr->ether_addr_octet[4],
156 addr->ether_addr_octet[5]);
158 memcpy(&client->client_id.mac_addr, addr, ETH_ALEN);
159 client->client_id.type = 0x01;
164 int sd_dhcp_client_get_lease(sd_dhcp_client *client, sd_dhcp_lease **ret) {
165 assert_return(client, -EINVAL);
166 assert_return(ret, -EINVAL);
168 if (client->state != DHCP_STATE_BOUND &&
169 client->state != DHCP_STATE_RENEWING &&
170 client->state != DHCP_STATE_REBINDING)
171 return -EADDRNOTAVAIL;
173 *ret = sd_dhcp_lease_ref(client->lease);
178 static int client_notify(sd_dhcp_client *client, int event) {
180 client->cb(client, event, client->userdata);
185 static int client_initialize(sd_dhcp_client *client) {
186 assert_return(client, -EINVAL);
188 client->receive_message =
189 sd_event_source_unref(client->receive_message);
191 client->fd = safe_close(client->fd);
193 client->timeout_resend = sd_event_source_unref(client->timeout_resend);
195 client->timeout_t1 = sd_event_source_unref(client->timeout_t1);
196 client->timeout_t2 = sd_event_source_unref(client->timeout_t2);
197 client->timeout_expire = sd_event_source_unref(client->timeout_expire);
201 client->state = DHCP_STATE_INIT;
205 client->lease = sd_dhcp_lease_unref(client->lease);
210 static int client_stop(sd_dhcp_client *client, int error) {
211 assert_return(client, -EINVAL);
213 client_notify(client, error);
215 client_initialize(client);
217 log_dhcp_client(client, "STOPPED");
222 static int client_message_init(sd_dhcp_client *client, DHCPMessage *message,
223 uint8_t type, uint8_t **opt, size_t *optlen) {
227 assert(client->secs);
232 r = dhcp_message_init(message, BOOTREQUEST, client->xid, type, opt,
237 /* Although 'secs' field is a SHOULD in RFC 2131, certain DHCP servers
238 refuse to issue an DHCP lease if 'secs' is set to zero */
239 message->secs = htobe16(client->secs);
241 memcpy(&message->chaddr, &client->client_id.mac_addr, ETH_ALEN);
243 if (client->state == DHCP_STATE_RENEWING ||
244 client->state == DHCP_STATE_REBINDING)
245 message->ciaddr = client->lease->address;
247 /* Some DHCP servers will refuse to issue an DHCP lease if the Client
248 Identifier option is not set */
249 r = dhcp_option_append(opt, optlen, DHCP_OPTION_CLIENT_IDENTIFIER,
250 sizeof(client->client_id), &client->client_id);
254 if (type == DHCP_DISCOVER || type == DHCP_REQUEST) {
257 r = dhcp_option_append(opt, optlen,
258 DHCP_OPTION_PARAMETER_REQUEST_LIST,
259 client->req_opts_size,
264 /* Some DHCP servers will send bigger DHCP packets than the
265 defined default size unless the Maximum Messge Size option
266 is explicitely set */
267 max_size = htobe16(DHCP_IP_UDP_SIZE + DHCP_MESSAGE_SIZE +
268 DHCP_MIN_OPTIONS_SIZE);
269 r = dhcp_option_append(opt, optlen,
270 DHCP_OPTION_MAXIMUM_MESSAGE_SIZE,
279 static int dhcp_client_send_raw(sd_dhcp_client *client, DHCPPacket *packet,
281 dhcp_packet_append_ip_headers(packet, INADDR_ANY, DHCP_PORT_CLIENT,
282 INADDR_BROADCAST, DHCP_PORT_SERVER, len);
284 return dhcp_network_send_raw_socket(client->fd, &client->link,
288 static int client_send_discover(sd_dhcp_client *client) {
289 _cleanup_free_ DHCPPacket *discover;
297 r = sd_event_get_now_monotonic(client->event, &time_now);
300 assert(time_now >= client->start_time);
302 /* seconds between sending first and last DISCOVER
303 * must always be strictly positive to deal with broken servers */
304 client->secs = ((time_now - client->start_time) / USEC_PER_SEC) ? : 1;
306 optlen = DHCP_MIN_OPTIONS_SIZE;
307 len = sizeof(DHCPPacket) + optlen;
309 discover = malloc0(len);
313 r = client_message_init(client, &discover->dhcp, DHCP_DISCOVER,
318 if (client->last_addr != INADDR_ANY) {
319 r = dhcp_option_append(&opt, &optlen,
320 DHCP_OPTION_REQUESTED_IP_ADDRESS,
321 4, &client->last_addr);
326 r = dhcp_option_append(&opt, &optlen, DHCP_OPTION_END, 0, NULL);
330 r = dhcp_client_send_raw(client, discover, len - optlen);
334 log_dhcp_client(client, "DISCOVER");
339 static int client_send_request(sd_dhcp_client *client) {
340 _cleanup_free_ DHCPPacket *request;
345 optlen = DHCP_MIN_OPTIONS_SIZE;
346 len = sizeof(DHCPPacket) + optlen;
348 request = malloc0(len);
352 r = client_message_init(client, &request->dhcp, DHCP_REQUEST, &opt,
357 switch (client->state) {
359 case DHCP_STATE_INIT_REBOOT:
360 r = dhcp_option_append(&opt, &optlen,
361 DHCP_OPTION_REQUESTED_IP_ADDRESS,
362 4, &client->last_addr);
367 case DHCP_STATE_REQUESTING:
368 r = dhcp_option_append(&opt, &optlen,
369 DHCP_OPTION_REQUESTED_IP_ADDRESS,
370 4, &client->lease->address);
374 r = dhcp_option_append(&opt, &optlen,
375 DHCP_OPTION_SERVER_IDENTIFIER,
376 4, &client->lease->server_address);
381 case DHCP_STATE_INIT:
382 case DHCP_STATE_SELECTING:
383 case DHCP_STATE_REBOOTING:
384 case DHCP_STATE_BOUND:
385 case DHCP_STATE_RENEWING:
386 case DHCP_STATE_REBINDING:
391 r = dhcp_option_append(&opt, &optlen, DHCP_OPTION_END, 0, NULL);
395 if (client->state == DHCP_STATE_RENEWING) {
396 r = dhcp_network_send_udp_socket(client->fd,
397 client->lease->server_address,
400 len - optlen - DHCP_IP_UDP_SIZE);
402 r = dhcp_client_send_raw(client, request, len - optlen);
407 log_dhcp_client(client, "REQUEST");
412 static int client_timeout_resend(sd_event_source *s, uint64_t usec,
414 sd_dhcp_client *client = userdata;
415 usec_t next_timeout = 0;
422 assert(client->event);
424 r = sd_event_get_now_monotonic(client->event, &time_now);
428 switch (client->state) {
429 case DHCP_STATE_RENEWING:
431 time_left = (client->lease->t2 - client->lease->t1) / 2;
435 next_timeout = time_now + time_left * USEC_PER_SEC;
439 case DHCP_STATE_REBINDING:
441 time_left = (client->lease->lifetime - client->lease->t2) / 2;
445 next_timeout = time_now + time_left * USEC_PER_SEC;
448 case DHCP_STATE_REBOOTING:
449 /* start over as we did not receive a timely ack or nak */
450 client->state = DHCP_STATE_INIT;
452 client->xid = random_u32();
455 case DHCP_STATE_INIT:
456 case DHCP_STATE_INIT_REBOOT:
457 case DHCP_STATE_SELECTING:
458 case DHCP_STATE_REQUESTING:
459 case DHCP_STATE_BOUND:
461 if (client->attempt < 64)
462 client->attempt *= 2;
464 next_timeout = time_now + (client->attempt - 1) * USEC_PER_SEC;
469 next_timeout += (random_u32() & 0x1fffff);
471 client->timeout_resend = sd_event_source_unref(client->timeout_resend);
473 r = sd_event_add_monotonic(client->event,
474 &client->timeout_resend,
477 client_timeout_resend, client);
481 r = sd_event_source_set_priority(client->timeout_resend,
482 client->event_priority);
486 switch (client->state) {
487 case DHCP_STATE_INIT:
488 r = client_send_discover(client);
490 client->state = DHCP_STATE_SELECTING;
493 if (client->attempt >= 64)
499 case DHCP_STATE_SELECTING:
500 r = client_send_discover(client);
501 if (r < 0 && client->attempt >= 64)
506 case DHCP_STATE_INIT_REBOOT:
507 case DHCP_STATE_REQUESTING:
508 case DHCP_STATE_RENEWING:
509 case DHCP_STATE_REBINDING:
510 r = client_send_request(client);
511 if (r < 0 && client->attempt >= 64)
514 if (client->state == DHCP_STATE_INIT_REBOOT)
515 client->state = DHCP_STATE_REBOOTING;
517 client->request_sent = time_now;
521 case DHCP_STATE_REBOOTING:
522 case DHCP_STATE_BOUND:
530 client_stop(client, r);
532 /* Errors were dealt with when stopping the client, don't spill
533 errors into the event loop handler */
537 static int client_initialize_events(sd_dhcp_client *client,
538 sd_event_io_handler_t io_callback) {
542 assert(client->event);
544 r = sd_event_add_io(client->event, &client->receive_message,
545 client->fd, EPOLLIN, io_callback,
550 r = sd_event_source_set_priority(client->receive_message,
551 client->event_priority);
555 client->timeout_resend = sd_event_source_unref(client->timeout_resend);
557 r = sd_event_add_monotonic(client->event,
558 &client->timeout_resend, 0, 0,
559 client_timeout_resend, client);
563 r = sd_event_source_set_priority(client->timeout_resend,
564 client->event_priority);
568 client_stop(client, r);
574 static int client_start(sd_dhcp_client *client) {
577 assert_return(client, -EINVAL);
578 assert_return(client->event, -EINVAL);
579 assert_return(client->index > 0, -EINVAL);
580 assert_return(client->fd < 0, -EBUSY);
581 assert_return(client->xid == 0, -EINVAL);
582 assert_return(client->state == DHCP_STATE_INIT ||
583 client->state == DHCP_STATE_INIT_REBOOT, -EBUSY);
585 client->xid = random_u32();
587 r = dhcp_network_bind_raw_socket(client->index, &client->link);
590 client_stop(client, r);
595 if (client->state == DHCP_STATE_INIT) {
596 client->start_time = now(CLOCK_MONOTONIC);
600 log_dhcp_client(client, "STARTED");
602 return client_initialize_events(client, client_receive_message_raw);
605 static int client_timeout_expire(sd_event_source *s, uint64_t usec,
607 sd_dhcp_client *client = userdata;
609 log_dhcp_client(client, "EXPIRED");
611 client_notify(client, DHCP_EVENT_EXPIRED);
613 /* start over as the lease was lost */
614 client_initialize(client);
615 client_start(client);
620 static int client_timeout_t2(sd_event_source *s, uint64_t usec, void *userdata) {
621 sd_dhcp_client *client = userdata;
624 client->receive_message = sd_event_source_unref(client->receive_message);
625 client->fd = safe_close(client->fd);
627 client->state = DHCP_STATE_REBINDING;
630 r = dhcp_network_bind_raw_socket(client->index, &client->link);
632 client_stop(client, r);
638 log_dhcp_client(client, "TIMEOUT T2");
640 return client_initialize_events(client, client_receive_message_raw);
643 static int client_timeout_t1(sd_event_source *s, uint64_t usec,
645 sd_dhcp_client *client = userdata;
648 client->state = DHCP_STATE_RENEWING;
651 r = dhcp_network_bind_udp_socket(client->index,
652 client->lease->address,
655 client_stop(client, r);
661 log_dhcp_client(client, "TIMEOUT T1");
663 return client_initialize_events(client, client_receive_message_udp);
666 static int client_handle_offer(sd_dhcp_client *client, DHCPMessage *offer,
668 _cleanup_dhcp_lease_unref_ sd_dhcp_lease *lease = NULL;
671 r = dhcp_lease_new(&lease);
675 r = dhcp_option_parse(offer, len, dhcp_lease_parse_options, lease);
679 lease->next_server = offer->siaddr;
681 lease->address = offer->yiaddr;
683 if (lease->address == INADDR_ANY ||
684 lease->server_address == INADDR_ANY ||
685 lease->subnet_mask == INADDR_ANY ||
686 lease->lifetime == 0)
689 client->lease = lease;
692 log_dhcp_client(client, "OFFER");
697 static int client_handle_ack(sd_dhcp_client *client, DHCPMessage *ack,
699 _cleanup_dhcp_lease_unref_ sd_dhcp_lease *lease = NULL;
702 r = dhcp_lease_new(&lease);
706 r = dhcp_option_parse(ack, len, dhcp_lease_parse_options, lease);
708 log_dhcp_client(client, "NAK");
709 return DHCP_EVENT_NO_LEASE;
715 lease->next_server = ack->siaddr;
717 lease->address = ack->yiaddr;
719 if (lease->address == INADDR_ANY ||
720 lease->server_address == INADDR_ANY ||
721 lease->subnet_mask == INADDR_ANY || lease->lifetime == 0)
724 r = DHCP_EVENT_IP_ACQUIRE;
726 if (client->lease->address != lease->address ||
727 client->lease->subnet_mask != lease->subnet_mask ||
728 client->lease->router != lease->router) {
729 r = DHCP_EVENT_IP_CHANGE;
732 client->lease = sd_dhcp_lease_unref(client->lease);
735 client->lease = lease;
738 log_dhcp_client(client, "ACK");
743 static uint64_t client_compute_timeout(sd_dhcp_client *client,
744 uint32_t lifetime, double factor) {
746 assert(client->request_sent);
749 return client->request_sent + ((lifetime - 3) * USEC_PER_SEC * factor) +
750 + (random_u32() & 0x1fffff);
753 static int client_set_lease_timeouts(sd_dhcp_client *client) {
755 uint64_t lifetime_timeout;
758 char time_string[FORMAT_TIMESPAN_MAX];
762 assert(client->event);
763 assert(client->lease);
764 assert(client->lease->lifetime);
766 client->timeout_t1 = sd_event_source_unref(client->timeout_t1);
767 client->timeout_t2 = sd_event_source_unref(client->timeout_t2);
768 client->timeout_expire = sd_event_source_unref(client->timeout_expire);
770 /* don't set timers for infinite leases */
771 if (client->lease->lifetime == 0xffffffff)
774 r = sd_event_get_now_monotonic(client->event, &time_now);
777 assert(client->request_sent <= time_now);
779 /* convert the various timeouts from relative (secs) to absolute (usecs) */
780 lifetime_timeout = client_compute_timeout(client, client->lease->lifetime, 1);
781 if (client->lease->t1 && client->lease->t2) {
782 /* both T1 and T2 are given */
783 if (client->lease->t1 < client->lease->t2 &&
784 client->lease->t2 < client->lease->lifetime) {
785 /* they are both valid */
786 t2_timeout = client_compute_timeout(client, client->lease->t2, 1);
787 t1_timeout = client_compute_timeout(client, client->lease->t1, 1);
790 t2_timeout = client_compute_timeout(client, client->lease->lifetime, 7.0 / 8.0);
791 client->lease->t2 = (client->lease->lifetime * 7) / 8;
792 t1_timeout = client_compute_timeout(client, client->lease->lifetime, 0.5);
793 client->lease->t1 = client->lease->lifetime / 2;
795 } else if (client->lease->t2 && client->lease->t2 < client->lease->lifetime) {
796 /* only T2 is given, and it is valid */
797 t2_timeout = client_compute_timeout(client, client->lease->t2, 1);
798 t1_timeout = client_compute_timeout(client, client->lease->lifetime, 0.5);
799 client->lease->t1 = client->lease->lifetime / 2;
800 if (t2_timeout <= t1_timeout) {
801 /* the computed T1 would be invalid, so discard T2 */
802 t2_timeout = client_compute_timeout(client, client->lease->lifetime, 7.0 / 8.0);
803 client->lease->t2 = (client->lease->lifetime * 7) / 8;
805 } else if (client->lease->t1 && client->lease->t1 < client->lease->lifetime) {
806 /* only T1 is given, and it is valid */
807 t1_timeout = client_compute_timeout(client, client->lease->t1, 1);
808 t2_timeout = client_compute_timeout(client, client->lease->lifetime, 7.0 / 8.0);
809 client->lease->t2 = (client->lease->lifetime * 7) / 8;
810 if (t2_timeout <= t1_timeout) {
811 /* the computed T2 would be invalid, so discard T1 */
812 t2_timeout = client_compute_timeout(client, client->lease->lifetime, 0.5);
813 client->lease->t2 = client->lease->lifetime / 2;
816 /* fall back to the default timeouts */
817 t1_timeout = client_compute_timeout(client, client->lease->lifetime, 0.5);
818 client->lease->t1 = client->lease->lifetime / 2;
819 t2_timeout = client_compute_timeout(client, client->lease->lifetime, 7.0 / 8.0);
820 client->lease->t2 = (client->lease->lifetime * 7) / 8;
823 /* arm lifetime timeout */
824 r = sd_event_add_monotonic(client->event,
825 &client->timeout_expire, lifetime_timeout,
827 client_timeout_expire, client);
831 r = sd_event_source_set_priority(client->timeout_expire,
832 client->event_priority);
836 log_dhcp_client(client, "lease expires in %s",
837 format_timespan(time_string, FORMAT_TIMESPAN_MAX,
838 lifetime_timeout - time_now, 0));
840 /* don't arm earlier timeouts if this has already expired */
841 if (lifetime_timeout <= time_now)
845 r = sd_event_add_monotonic(client->event,
849 client_timeout_t2, client);
853 r = sd_event_source_set_priority(client->timeout_t2,
854 client->event_priority);
858 log_dhcp_client(client, "T2 expires in %s",
859 format_timespan(time_string, FORMAT_TIMESPAN_MAX,
860 t2_timeout - time_now, 0));
862 /* don't arm earlier timeout if this has already expired */
863 if (t2_timeout <= time_now)
867 r = sd_event_add_monotonic(client->event,
871 client_timeout_t1, client);
875 r = sd_event_source_set_priority(client->timeout_t1,
876 client->event_priority);
880 log_dhcp_client(client, "T1 expires in %s",
881 format_timespan(time_string, FORMAT_TIMESPAN_MAX,
882 t1_timeout - time_now, 0));
887 static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message,
889 int r = 0, notify_event = 0;
892 assert(client->event);
895 if (len < DHCP_MESSAGE_SIZE) {
896 log_dhcp_client(client, "message too small (%d bytes): "
901 if (message->op != BOOTREPLY) {
902 log_dhcp_client(client, "not a BOOTREPLY message: ignoring");
906 if (be32toh(message->xid) != client->xid) {
907 log_dhcp_client(client, "received xid (%u) does not match "
908 "expected (%u): ignoring",
909 be32toh(message->xid), client->xid);
913 if (memcmp(&message->chaddr[0], &client->client_id.mac_addr,
915 log_dhcp_client(client, "received chaddr does not match "
916 "expected: ignoring");
920 switch (client->state) {
921 case DHCP_STATE_SELECTING:
923 r = client_handle_offer(client, message, len);
926 client->timeout_resend =
927 sd_event_source_unref(client->timeout_resend);
929 client->state = DHCP_STATE_REQUESTING;
932 r = sd_event_add_monotonic(client->event,
933 &client->timeout_resend, 0,
934 0, client_timeout_resend,
939 r = sd_event_source_set_priority(client->timeout_resend,
940 client->event_priority);
947 case DHCP_STATE_REBOOTING:
948 case DHCP_STATE_REQUESTING:
949 case DHCP_STATE_RENEWING:
950 case DHCP_STATE_REBINDING:
952 r = client_handle_ack(client, message, len);
954 if (r == DHCP_EVENT_NO_LEASE) {
956 client->timeout_resend =
957 sd_event_source_unref(client->timeout_resend);
959 if (client->state == DHCP_STATE_REBOOTING) {
960 r = client_initialize(client);
964 r = client_start(client);
973 client->timeout_resend =
974 sd_event_source_unref(client->timeout_resend);
976 if (IN_SET(client->state, DHCP_STATE_REQUESTING,
977 DHCP_STATE_REBOOTING))
978 notify_event = DHCP_EVENT_IP_ACQUIRE;
979 else if (r != DHCP_EVENT_IP_ACQUIRE)
982 client->state = DHCP_STATE_BOUND;
985 client->last_addr = client->lease->address;
987 r = client_set_lease_timeouts(client);
992 client_notify(client, notify_event);
994 client->receive_message =
995 sd_event_source_unref(client->receive_message);
996 client->fd = safe_close(client->fd);
1003 case DHCP_STATE_INIT:
1004 case DHCP_STATE_INIT_REBOOT:
1005 case DHCP_STATE_BOUND:
1011 if (r < 0 || r == DHCP_EVENT_NO_LEASE)
1012 return client_stop(client, r);
1017 static int client_receive_message_udp(sd_event_source *s, int fd,
1018 uint32_t revents, void *userdata) {
1019 sd_dhcp_client *client = userdata;
1020 _cleanup_free_ DHCPMessage *message = NULL;
1021 int buflen = 0, len, r;
1026 r = ioctl(fd, FIONREAD, &buflen);
1027 if (r < 0 || buflen <= 0)
1028 buflen = sizeof(DHCPMessage) + DHCP_MIN_OPTIONS_SIZE;
1030 message = malloc0(buflen);
1034 len = read(fd, message, buflen);
1038 return client_handle_message(client, message, len);
1041 static int client_receive_message_raw(sd_event_source *s, int fd,
1042 uint32_t revents, void *userdata) {
1043 sd_dhcp_client *client = userdata;
1044 _cleanup_free_ DHCPPacket *packet = NULL;
1045 uint8_t cmsgbuf[CMSG_LEN(sizeof(struct tpacket_auxdata))];
1046 struct iovec iov = {};
1047 struct msghdr msg = {
1050 .msg_control = cmsgbuf,
1051 .msg_controllen = sizeof(cmsgbuf),
1053 struct cmsghdr *cmsg;
1054 bool checksum = true;
1055 int buflen = 0, len, r;
1060 r = ioctl(fd, FIONREAD, &buflen);
1061 if (r < 0 || buflen <= 0)
1062 buflen = sizeof(DHCPPacket) + DHCP_MIN_OPTIONS_SIZE;
1064 packet = malloc0(buflen);
1068 iov.iov_base = packet;
1069 iov.iov_len = buflen;
1071 len = recvmsg(fd, &msg, 0);
1073 log_dhcp_client(client, "could not receive message from raw "
1074 "socket: %s", strerror(errno));
1078 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
1079 if (cmsg->cmsg_level == SOL_PACKET && cmsg->cmsg_type == PACKET_AUXDATA) {
1080 struct tpacket_auxdata *aux = (void *)CMSG_DATA(cmsg);
1082 checksum = !(aux->tp_status & TP_STATUS_CSUMNOTREADY);
1087 r = dhcp_packet_verify_headers(packet, len, checksum);
1091 len -= DHCP_IP_UDP_SIZE;
1093 return client_handle_message(client, &packet->dhcp, len);
1096 int sd_dhcp_client_start(sd_dhcp_client *client) {
1099 assert_return(client, -EINVAL);
1101 r = client_initialize(client);
1105 if (client->last_addr)
1106 client->state = DHCP_STATE_INIT_REBOOT;
1108 return client_start(client);
1111 int sd_dhcp_client_stop(sd_dhcp_client *client) {
1112 return client_stop(client, DHCP_EVENT_STOP);
1115 int sd_dhcp_client_attach_event(sd_dhcp_client *client, sd_event *event,
1119 assert_return(client, -EINVAL);
1120 assert_return(!client->event, -EBUSY);
1123 client->event = sd_event_ref(event);
1125 r = sd_event_default(&client->event);
1130 client->event_priority = priority;
1135 int sd_dhcp_client_detach_event(sd_dhcp_client *client) {
1136 assert_return(client, -EINVAL);
1138 client->event = sd_event_unref(client->event);
1143 sd_event *sd_dhcp_client_get_event(sd_dhcp_client *client) {
1147 return client->event;
1150 void sd_dhcp_client_free(sd_dhcp_client *client) {
1154 sd_dhcp_client_stop(client);
1155 sd_dhcp_client_detach_event(client);
1157 free(client->req_opts);
1161 DEFINE_TRIVIAL_CLEANUP_FUNC(sd_dhcp_client*, sd_dhcp_client_free);
1162 #define _cleanup_dhcp_client_free_ _cleanup_(sd_dhcp_client_freep)
1164 int sd_dhcp_client_new(sd_dhcp_client **ret) {
1165 _cleanup_dhcp_client_free_ sd_dhcp_client *client = NULL;
1167 assert_return(ret, -EINVAL);
1169 client = new0(sd_dhcp_client, 1);
1173 client->state = DHCP_STATE_INIT;
1176 client->attempt = 1;
1178 client->req_opts_size = ELEMENTSOF(default_req_opts);
1180 client->req_opts = memdup(default_req_opts, client->req_opts_size);
1181 if (!client->req_opts)