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Merge pull request #1058 from spasche/hwdb-logitech-mice
[thirdparty/systemd.git] / src / libsystemd-network / sd-dhcp-client.c
1 /***
2 This file is part of systemd.
3
4 Copyright (C) 2013 Intel Corporation. All rights reserved.
5
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.
10
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.
15
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/>.
18 ***/
19
20 #include <stdlib.h>
21 #include <errno.h>
22 #include <string.h>
23 #include <stdio.h>
24 #include <net/ethernet.h>
25 #include <net/if_arp.h>
26 #include <linux/if_infiniband.h>
27 #include <sys/ioctl.h>
28
29 #include "util.h"
30 #include "random-util.h"
31 #include "async.h"
32
33 #include "dhcp-protocol.h"
34 #include "dhcp-internal.h"
35 #include "dhcp-lease-internal.h"
36 #include "dhcp-identifier.h"
37 #include "sd-dhcp-client.h"
38
39 #define MAX_CLIENT_ID_LEN (sizeof(uint32_t) + MAX_DUID_LEN) /* Arbitrary limit */
40 #define MAX_MAC_ADDR_LEN CONST_MAX(INFINIBAND_ALEN, ETH_ALEN)
41
42 struct sd_dhcp_client {
43 unsigned n_ref;
44
45 DHCPState state;
46 sd_event *event;
47 int event_priority;
48 sd_event_source *timeout_resend;
49 int index;
50 int fd;
51 union sockaddr_union link;
52 sd_event_source *receive_message;
53 bool request_broadcast;
54 uint8_t *req_opts;
55 size_t req_opts_allocated;
56 size_t req_opts_size;
57 be32_t last_addr;
58 uint8_t mac_addr[MAX_MAC_ADDR_LEN];
59 size_t mac_addr_len;
60 uint16_t arp_type;
61 struct {
62 uint8_t type;
63 union {
64 struct {
65 /* 0: Generic (non-LL) (RFC 2132) */
66 uint8_t data[MAX_CLIENT_ID_LEN];
67 } _packed_ gen;
68 struct {
69 /* 1: Ethernet Link-Layer (RFC 2132) */
70 uint8_t haddr[ETH_ALEN];
71 } _packed_ eth;
72 struct {
73 /* 2 - 254: ARP/Link-Layer (RFC 2132) */
74 uint8_t haddr[0];
75 } _packed_ ll;
76 struct {
77 /* 255: Node-specific (RFC 4361) */
78 uint32_t iaid;
79 struct duid duid;
80 } _packed_ ns;
81 struct {
82 uint8_t data[MAX_CLIENT_ID_LEN];
83 } _packed_ raw;
84 };
85 } _packed_ client_id;
86 size_t client_id_len;
87 char *hostname;
88 char *vendor_class_identifier;
89 uint32_t mtu;
90 uint32_t xid;
91 usec_t start_time;
92 unsigned int attempt;
93 usec_t request_sent;
94 sd_event_source *timeout_t1;
95 sd_event_source *timeout_t2;
96 sd_event_source *timeout_expire;
97 sd_dhcp_client_cb_t cb;
98 void *userdata;
99 sd_dhcp_lease *lease;
100 };
101
102 static const uint8_t default_req_opts[] = {
103 DHCP_OPTION_SUBNET_MASK,
104 DHCP_OPTION_ROUTER,
105 DHCP_OPTION_HOST_NAME,
106 DHCP_OPTION_DOMAIN_NAME,
107 DHCP_OPTION_DOMAIN_NAME_SERVER,
108 };
109
110 static int client_receive_message_raw(sd_event_source *s, int fd,
111 uint32_t revents, void *userdata);
112 static int client_receive_message_udp(sd_event_source *s, int fd,
113 uint32_t revents, void *userdata);
114 static void client_stop(sd_dhcp_client *client, int error);
115
116 int sd_dhcp_client_set_callback(sd_dhcp_client *client, sd_dhcp_client_cb_t cb,
117 void *userdata) {
118 assert_return(client, -EINVAL);
119
120 client->cb = cb;
121 client->userdata = userdata;
122
123 return 0;
124 }
125
126 int sd_dhcp_client_set_request_broadcast(sd_dhcp_client *client, int broadcast) {
127 assert_return(client, -EINVAL);
128
129 client->request_broadcast = !!broadcast;
130
131 return 0;
132 }
133
134 int sd_dhcp_client_set_request_option(sd_dhcp_client *client, uint8_t option) {
135 size_t i;
136
137 assert_return(client, -EINVAL);
138 assert_return (IN_SET(client->state, DHCP_STATE_INIT,
139 DHCP_STATE_STOPPED), -EBUSY);
140
141 switch(option) {
142 case DHCP_OPTION_PAD:
143 case DHCP_OPTION_OVERLOAD:
144 case DHCP_OPTION_MESSAGE_TYPE:
145 case DHCP_OPTION_PARAMETER_REQUEST_LIST:
146 case DHCP_OPTION_END:
147 return -EINVAL;
148
149 default:
150 break;
151 }
152
153 for (i = 0; i < client->req_opts_size; i++)
154 if (client->req_opts[i] == option)
155 return -EEXIST;
156
157 if (!GREEDY_REALLOC(client->req_opts, client->req_opts_allocated,
158 client->req_opts_size + 1))
159 return -ENOMEM;
160
161 client->req_opts[client->req_opts_size++] = option;
162
163 return 0;
164 }
165
166 int sd_dhcp_client_set_request_address(sd_dhcp_client *client,
167 const struct in_addr *last_addr) {
168 assert_return(client, -EINVAL);
169 assert_return (IN_SET(client->state, DHCP_STATE_INIT,
170 DHCP_STATE_STOPPED), -EBUSY);
171
172 if (last_addr)
173 client->last_addr = last_addr->s_addr;
174 else
175 client->last_addr = INADDR_ANY;
176
177 return 0;
178 }
179
180 int sd_dhcp_client_set_index(sd_dhcp_client *client, int interface_index) {
181 assert_return(client, -EINVAL);
182 assert_return (IN_SET(client->state, DHCP_STATE_INIT,
183 DHCP_STATE_STOPPED), -EBUSY);
184 assert_return(interface_index > 0, -EINVAL);
185
186 client->index = interface_index;
187
188 return 0;
189 }
190
191 int sd_dhcp_client_set_mac(sd_dhcp_client *client, const uint8_t *addr,
192 size_t addr_len, uint16_t arp_type) {
193 DHCP_CLIENT_DONT_DESTROY(client);
194 bool need_restart = false;
195
196 assert_return(client, -EINVAL);
197 assert_return(addr, -EINVAL);
198 assert_return(addr_len > 0 && addr_len <= MAX_MAC_ADDR_LEN, -EINVAL);
199 assert_return(arp_type > 0, -EINVAL);
200
201 if (arp_type == ARPHRD_ETHER)
202 assert_return(addr_len == ETH_ALEN, -EINVAL);
203 else if (arp_type == ARPHRD_INFINIBAND)
204 assert_return(addr_len == INFINIBAND_ALEN, -EINVAL);
205 else
206 return -EINVAL;
207
208 if (client->mac_addr_len == addr_len &&
209 memcmp(&client->mac_addr, addr, addr_len) == 0)
210 return 0;
211
212 if (!IN_SET(client->state, DHCP_STATE_INIT, DHCP_STATE_STOPPED)) {
213 log_dhcp_client(client, "Changing MAC address on running DHCP "
214 "client, restarting");
215 need_restart = true;
216 client_stop(client, DHCP_EVENT_STOP);
217 }
218
219 memcpy(&client->mac_addr, addr, addr_len);
220 client->mac_addr_len = addr_len;
221 client->arp_type = arp_type;
222
223 if (need_restart && client->state != DHCP_STATE_STOPPED)
224 sd_dhcp_client_start(client);
225
226 return 0;
227 }
228
229 int sd_dhcp_client_get_client_id(sd_dhcp_client *client, uint8_t *type,
230 const uint8_t **data, size_t *data_len) {
231
232 assert_return(client, -EINVAL);
233 assert_return(type, -EINVAL);
234 assert_return(data, -EINVAL);
235 assert_return(data_len, -EINVAL);
236
237 *type = 0;
238 *data = NULL;
239 *data_len = 0;
240 if (client->client_id_len) {
241 *type = client->client_id.type;
242 *data = client->client_id.raw.data;
243 *data_len = client->client_id_len - sizeof(client->client_id.type);
244 }
245
246 return 0;
247 }
248
249 int sd_dhcp_client_set_client_id(sd_dhcp_client *client, uint8_t type,
250 const uint8_t *data, size_t data_len) {
251 DHCP_CLIENT_DONT_DESTROY(client);
252 bool need_restart = false;
253
254 assert_return(client, -EINVAL);
255 assert_return(data, -EINVAL);
256 assert_return(data_len > 0 && data_len <= MAX_CLIENT_ID_LEN, -EINVAL);
257
258 switch (type) {
259 case ARPHRD_ETHER:
260 if (data_len != ETH_ALEN)
261 return -EINVAL;
262 break;
263 case ARPHRD_INFINIBAND:
264 if (data_len != INFINIBAND_ALEN)
265 return -EINVAL;
266 break;
267 default:
268 break;
269 }
270
271 if (client->client_id_len == data_len + sizeof(client->client_id.type) &&
272 client->client_id.type == type &&
273 memcmp(&client->client_id.raw.data, data, data_len) == 0)
274 return 0;
275
276 if (!IN_SET(client->state, DHCP_STATE_INIT, DHCP_STATE_STOPPED)) {
277 log_dhcp_client(client, "Changing client ID on running DHCP "
278 "client, restarting");
279 need_restart = true;
280 client_stop(client, DHCP_EVENT_STOP);
281 }
282
283 client->client_id.type = type;
284 memcpy(&client->client_id.raw.data, data, data_len);
285 client->client_id_len = data_len + sizeof (client->client_id.type);
286
287 if (need_restart && client->state != DHCP_STATE_STOPPED)
288 sd_dhcp_client_start(client);
289
290 return 0;
291 }
292
293 int sd_dhcp_client_set_hostname(sd_dhcp_client *client,
294 const char *hostname) {
295 char *new_hostname = NULL;
296
297 assert_return(client, -EINVAL);
298
299 if (streq_ptr(client->hostname, hostname))
300 return 0;
301
302 if (hostname) {
303 new_hostname = strdup(hostname);
304 if (!new_hostname)
305 return -ENOMEM;
306 }
307
308 free(client->hostname);
309 client->hostname = new_hostname;
310
311 return 0;
312 }
313
314 int sd_dhcp_client_set_vendor_class_identifier(sd_dhcp_client *client,
315 const char *vci) {
316 char *new_vci = NULL;
317
318 assert_return(client, -EINVAL);
319
320 new_vci = strdup(vci);
321 if (!new_vci)
322 return -ENOMEM;
323
324 free(client->vendor_class_identifier);
325
326 client->vendor_class_identifier = new_vci;
327
328 return 0;
329 }
330
331 int sd_dhcp_client_set_mtu(sd_dhcp_client *client, uint32_t mtu) {
332 assert_return(client, -EINVAL);
333 assert_return(mtu >= DHCP_DEFAULT_MIN_SIZE, -ERANGE);
334
335 client->mtu = mtu;
336
337 return 0;
338 }
339
340 int sd_dhcp_client_get_lease(sd_dhcp_client *client, sd_dhcp_lease **ret) {
341 assert_return(client, -EINVAL);
342 assert_return(ret, -EINVAL);
343
344 if (client->state != DHCP_STATE_BOUND &&
345 client->state != DHCP_STATE_RENEWING &&
346 client->state != DHCP_STATE_REBINDING)
347 return -EADDRNOTAVAIL;
348
349 *ret = client->lease;
350
351 return 0;
352 }
353
354 static void client_notify(sd_dhcp_client *client, int event) {
355 if (client->cb)
356 client->cb(client, event, client->userdata);
357 }
358
359 static int client_initialize(sd_dhcp_client *client) {
360 assert_return(client, -EINVAL);
361
362 client->receive_message =
363 sd_event_source_unref(client->receive_message);
364
365 client->fd = asynchronous_close(client->fd);
366
367 client->timeout_resend = sd_event_source_unref(client->timeout_resend);
368
369 client->timeout_t1 = sd_event_source_unref(client->timeout_t1);
370 client->timeout_t2 = sd_event_source_unref(client->timeout_t2);
371 client->timeout_expire = sd_event_source_unref(client->timeout_expire);
372
373 client->attempt = 1;
374
375 client->state = DHCP_STATE_INIT;
376 client->xid = 0;
377
378 client->lease = sd_dhcp_lease_unref(client->lease);
379
380 return 0;
381 }
382
383 static void client_stop(sd_dhcp_client *client, int error) {
384 assert(client);
385
386 if (error < 0)
387 log_dhcp_client(client, "STOPPED: %s", strerror(-error));
388 else if (error == DHCP_EVENT_STOP)
389 log_dhcp_client(client, "STOPPED");
390 else
391 log_dhcp_client(client, "STOPPED: Unknown event");
392
393 client_notify(client, error);
394
395 client_initialize(client);
396 }
397
398 static int client_message_init(sd_dhcp_client *client, DHCPPacket **ret,
399 uint8_t type, size_t *_optlen, size_t *_optoffset) {
400 _cleanup_free_ DHCPPacket *packet;
401 size_t optlen, optoffset, size;
402 be16_t max_size;
403 usec_t time_now;
404 uint16_t secs;
405 int r;
406
407 assert(client);
408 assert(client->start_time);
409 assert(ret);
410 assert(_optlen);
411 assert(_optoffset);
412 assert(type == DHCP_DISCOVER || type == DHCP_REQUEST);
413
414 optlen = DHCP_MIN_OPTIONS_SIZE;
415 size = sizeof(DHCPPacket) + optlen;
416
417 packet = malloc0(size);
418 if (!packet)
419 return -ENOMEM;
420
421 r = dhcp_message_init(&packet->dhcp, BOOTREQUEST, client->xid, type,
422 client->arp_type, optlen, &optoffset);
423 if (r < 0)
424 return r;
425
426 /* Although 'secs' field is a SHOULD in RFC 2131, certain DHCP servers
427 refuse to issue an DHCP lease if 'secs' is set to zero */
428 r = sd_event_now(client->event, clock_boottime_or_monotonic(), &time_now);
429 if (r < 0)
430 return r;
431 assert(time_now >= client->start_time);
432
433 /* seconds between sending first and last DISCOVER
434 * must always be strictly positive to deal with broken servers */
435 secs = ((time_now - client->start_time) / USEC_PER_SEC) ? : 1;
436 packet->dhcp.secs = htobe16(secs);
437
438 /* RFC2132 section 4.1
439 A client that cannot receive unicast IP datagrams until its protocol
440 software has been configured with an IP address SHOULD set the
441 BROADCAST bit in the 'flags' field to 1 in any DHCPDISCOVER or
442 DHCPREQUEST messages that client sends. The BROADCAST bit will
443 provide a hint to the DHCP server and BOOTP relay agent to broadcast
444 any messages to the client on the client's subnet.
445
446 Note: some interfaces needs this to be enabled, but some networks
447 needs this to be disabled as broadcasts are filteretd, so this
448 needs to be configurable */
449 if (client->request_broadcast || client->arp_type != ARPHRD_ETHER)
450 packet->dhcp.flags = htobe16(0x8000);
451
452 /* RFC2132 section 4.1.1:
453 The client MUST include its hardware address in the ’chaddr’ field, if
454 necessary for delivery of DHCP reply messages. Non-Ethernet
455 interfaces will leave 'chaddr' empty and use the client identifier
456 instead (eg, RFC 4390 section 2.1).
457 */
458 if (client->arp_type == ARPHRD_ETHER)
459 memcpy(&packet->dhcp.chaddr, &client->mac_addr, ETH_ALEN);
460
461 /* If no client identifier exists, construct an RFC 4361-compliant one */
462 if (client->client_id_len == 0) {
463 size_t duid_len;
464
465 client->client_id.type = 255;
466
467 r = dhcp_identifier_set_iaid(client->index, client->mac_addr, client->mac_addr_len, &client->client_id.ns.iaid);
468 if (r < 0)
469 return r;
470
471 r = dhcp_identifier_set_duid_en(&client->client_id.ns.duid, &duid_len);
472 if (r < 0)
473 return r;
474
475 client->client_id_len = sizeof(client->client_id.type) + sizeof(client->client_id.ns.iaid) + duid_len;
476 }
477
478 /* Some DHCP servers will refuse to issue an DHCP lease if the Client
479 Identifier option is not set */
480 if (client->client_id_len) {
481 r = dhcp_option_append(&packet->dhcp, optlen, &optoffset, 0,
482 DHCP_OPTION_CLIENT_IDENTIFIER,
483 client->client_id_len,
484 &client->client_id);
485 if (r < 0)
486 return r;
487 }
488
489 /* RFC2131 section 3.5:
490 in its initial DHCPDISCOVER or DHCPREQUEST message, a
491 client may provide the server with a list of specific
492 parameters the client is interested in. If the client
493 includes a list of parameters in a DHCPDISCOVER message,
494 it MUST include that list in any subsequent DHCPREQUEST
495 messages.
496 */
497 r = dhcp_option_append(&packet->dhcp, optlen, &optoffset, 0,
498 DHCP_OPTION_PARAMETER_REQUEST_LIST,
499 client->req_opts_size, client->req_opts);
500 if (r < 0)
501 return r;
502
503 /* RFC2131 section 3.5:
504 The client SHOULD include the ’maximum DHCP message size’ option to
505 let the server know how large the server may make its DHCP messages.
506
507 Note (from ConnMan): Some DHCP servers will send bigger DHCP packets
508 than the defined default size unless the Maximum Messge Size option
509 is explicitly set
510
511 RFC3442 "Requirements to Avoid Sizing Constraints":
512 Because a full routing table can be quite large, the standard 576
513 octet maximum size for a DHCP message may be too short to contain
514 some legitimate Classless Static Route options. Because of this,
515 clients implementing the Classless Static Route option SHOULD send a
516 Maximum DHCP Message Size [4] option if the DHCP client's TCP/IP
517 stack is capable of receiving larger IP datagrams. In this case, the
518 client SHOULD set the value of this option to at least the MTU of the
519 interface that the client is configuring. The client MAY set the
520 value of this option higher, up to the size of the largest UDP packet
521 it is prepared to accept. (Note that the value specified in the
522 Maximum DHCP Message Size option is the total maximum packet size,
523 including IP and UDP headers.)
524 */
525 max_size = htobe16(size);
526 r = dhcp_option_append(&packet->dhcp, client->mtu, &optoffset, 0,
527 DHCP_OPTION_MAXIMUM_MESSAGE_SIZE,
528 2, &max_size);
529 if (r < 0)
530 return r;
531
532 *_optlen = optlen;
533 *_optoffset = optoffset;
534 *ret = packet;
535 packet = NULL;
536
537 return 0;
538 }
539
540 static int dhcp_client_send_raw(sd_dhcp_client *client, DHCPPacket *packet,
541 size_t len) {
542 dhcp_packet_append_ip_headers(packet, INADDR_ANY, DHCP_PORT_CLIENT,
543 INADDR_BROADCAST, DHCP_PORT_SERVER, len);
544
545 return dhcp_network_send_raw_socket(client->fd, &client->link,
546 packet, len);
547 }
548
549 static int client_send_discover(sd_dhcp_client *client) {
550 _cleanup_free_ DHCPPacket *discover = NULL;
551 size_t optoffset, optlen;
552 int r;
553
554 assert(client);
555 assert(client->state == DHCP_STATE_INIT ||
556 client->state == DHCP_STATE_SELECTING);
557
558 r = client_message_init(client, &discover, DHCP_DISCOVER,
559 &optlen, &optoffset);
560 if (r < 0)
561 return r;
562
563 /* the client may suggest values for the network address
564 and lease time in the DHCPDISCOVER message. The client may include
565 the ’requested IP address’ option to suggest that a particular IP
566 address be assigned, and may include the ’IP address lease time’
567 option to suggest the lease time it would like.
568 */
569 if (client->last_addr != INADDR_ANY) {
570 r = dhcp_option_append(&discover->dhcp, optlen, &optoffset, 0,
571 DHCP_OPTION_REQUESTED_IP_ADDRESS,
572 4, &client->last_addr);
573 if (r < 0)
574 return r;
575 }
576
577 /* it is unclear from RFC 2131 if client should send hostname in
578 DHCPDISCOVER but dhclient does and so we do as well
579 */
580 if (client->hostname) {
581 r = dhcp_option_append(&discover->dhcp, optlen, &optoffset, 0,
582 DHCP_OPTION_HOST_NAME,
583 strlen(client->hostname), client->hostname);
584 if (r < 0)
585 return r;
586 }
587
588 if (client->vendor_class_identifier) {
589 r = dhcp_option_append(&discover->dhcp, optlen, &optoffset, 0,
590 DHCP_OPTION_VENDOR_CLASS_IDENTIFIER,
591 strlen(client->vendor_class_identifier),
592 client->vendor_class_identifier);
593 if (r < 0)
594 return r;
595 }
596
597 r = dhcp_option_append(&discover->dhcp, optlen, &optoffset, 0,
598 DHCP_OPTION_END, 0, NULL);
599 if (r < 0)
600 return r;
601
602 /* We currently ignore:
603 The client SHOULD wait a random time between one and ten seconds to
604 desynchronize the use of DHCP at startup.
605 */
606 r = dhcp_client_send_raw(client, discover, sizeof(DHCPPacket) + optoffset);
607 if (r < 0)
608 return r;
609
610 log_dhcp_client(client, "DISCOVER");
611
612 return 0;
613 }
614
615 static int client_send_request(sd_dhcp_client *client) {
616 _cleanup_free_ DHCPPacket *request = NULL;
617 size_t optoffset, optlen;
618 int r;
619
620 r = client_message_init(client, &request, DHCP_REQUEST,
621 &optlen, &optoffset);
622 if (r < 0)
623 return r;
624
625 switch (client->state) {
626 /* See RFC2131 section 4.3.2 (note that there is a typo in the RFC,
627 SELECTING should be REQUESTING)
628 */
629
630 case DHCP_STATE_REQUESTING:
631 /* Client inserts the address of the selected server in ’server
632 identifier’, ’ciaddr’ MUST be zero, ’requested IP address’ MUST be
633 filled in with the yiaddr value from the chosen DHCPOFFER.
634 */
635
636 r = dhcp_option_append(&request->dhcp, optlen, &optoffset, 0,
637 DHCP_OPTION_SERVER_IDENTIFIER,
638 4, &client->lease->server_address);
639 if (r < 0)
640 return r;
641
642 r = dhcp_option_append(&request->dhcp, optlen, &optoffset, 0,
643 DHCP_OPTION_REQUESTED_IP_ADDRESS,
644 4, &client->lease->address);
645 if (r < 0)
646 return r;
647
648 break;
649
650 case DHCP_STATE_INIT_REBOOT:
651 /* ’server identifier’ MUST NOT be filled in, ’requested IP address’
652 option MUST be filled in with client’s notion of its previously
653 assigned address. ’ciaddr’ MUST be zero.
654 */
655 r = dhcp_option_append(&request->dhcp, optlen, &optoffset, 0,
656 DHCP_OPTION_REQUESTED_IP_ADDRESS,
657 4, &client->last_addr);
658 if (r < 0)
659 return r;
660 break;
661
662 case DHCP_STATE_RENEWING:
663 /* ’server identifier’ MUST NOT be filled in, ’requested IP address’
664 option MUST NOT be filled in, ’ciaddr’ MUST be filled in with
665 client’s IP address.
666 */
667
668 /* fall through */
669 case DHCP_STATE_REBINDING:
670 /* ’server identifier’ MUST NOT be filled in, ’requested IP address’
671 option MUST NOT be filled in, ’ciaddr’ MUST be filled in with
672 client’s IP address.
673
674 This message MUST be broadcast to the 0xffffffff IP broadcast address.
675 */
676 request->dhcp.ciaddr = client->lease->address;
677
678 break;
679
680 case DHCP_STATE_INIT:
681 case DHCP_STATE_SELECTING:
682 case DHCP_STATE_REBOOTING:
683 case DHCP_STATE_BOUND:
684 case DHCP_STATE_STOPPED:
685 return -EINVAL;
686 }
687
688 if (client->hostname) {
689 r = dhcp_option_append(&request->dhcp, optlen, &optoffset, 0,
690 DHCP_OPTION_HOST_NAME,
691 strlen(client->hostname), client->hostname);
692 if (r < 0)
693 return r;
694 }
695
696 r = dhcp_option_append(&request->dhcp, optlen, &optoffset, 0,
697 DHCP_OPTION_END, 0, NULL);
698 if (r < 0)
699 return r;
700
701 if (client->state == DHCP_STATE_RENEWING) {
702 r = dhcp_network_send_udp_socket(client->fd,
703 client->lease->server_address,
704 DHCP_PORT_SERVER,
705 &request->dhcp,
706 sizeof(DHCPMessage) + optoffset);
707 } else {
708 r = dhcp_client_send_raw(client, request, sizeof(DHCPPacket) + optoffset);
709 }
710 if (r < 0)
711 return r;
712
713 switch (client->state) {
714 case DHCP_STATE_REQUESTING:
715 log_dhcp_client(client, "REQUEST (requesting)");
716 break;
717 case DHCP_STATE_INIT_REBOOT:
718 log_dhcp_client(client, "REQUEST (init-reboot)");
719 break;
720 case DHCP_STATE_RENEWING:
721 log_dhcp_client(client, "REQUEST (renewing)");
722 break;
723 case DHCP_STATE_REBINDING:
724 log_dhcp_client(client, "REQUEST (rebinding)");
725 break;
726 default:
727 log_dhcp_client(client, "REQUEST (invalid)");
728 break;
729 }
730
731 return 0;
732 }
733
734 static int client_start(sd_dhcp_client *client);
735
736 static int client_timeout_resend(sd_event_source *s, uint64_t usec,
737 void *userdata) {
738 sd_dhcp_client *client = userdata;
739 DHCP_CLIENT_DONT_DESTROY(client);
740 usec_t next_timeout = 0;
741 uint64_t time_now;
742 uint32_t time_left;
743 int r;
744
745 assert(s);
746 assert(client);
747 assert(client->event);
748
749 r = sd_event_now(client->event, clock_boottime_or_monotonic(), &time_now);
750 if (r < 0)
751 goto error;
752
753 switch (client->state) {
754 case DHCP_STATE_RENEWING:
755
756 time_left = (client->lease->t2 - client->lease->t1) / 2;
757 if (time_left < 60)
758 time_left = 60;
759
760 next_timeout = time_now + time_left * USEC_PER_SEC;
761
762 break;
763
764 case DHCP_STATE_REBINDING:
765
766 time_left = (client->lease->lifetime - client->lease->t2) / 2;
767 if (time_left < 60)
768 time_left = 60;
769
770 next_timeout = time_now + time_left * USEC_PER_SEC;
771 break;
772
773 case DHCP_STATE_REBOOTING:
774 /* start over as we did not receive a timely ack or nak */
775 r = client_initialize(client);
776 if (r < 0)
777 goto error;
778
779 r = client_start(client);
780 if (r < 0)
781 goto error;
782 else {
783 log_dhcp_client(client, "REBOOTED");
784 return 0;
785 }
786
787 case DHCP_STATE_INIT:
788 case DHCP_STATE_INIT_REBOOT:
789 case DHCP_STATE_SELECTING:
790 case DHCP_STATE_REQUESTING:
791 case DHCP_STATE_BOUND:
792
793 if (client->attempt < 64)
794 client->attempt *= 2;
795
796 next_timeout = time_now + (client->attempt - 1) * USEC_PER_SEC;
797
798 break;
799
800 case DHCP_STATE_STOPPED:
801 r = -EINVAL;
802 goto error;
803 }
804
805 next_timeout += (random_u32() & 0x1fffff);
806
807 client->timeout_resend = sd_event_source_unref(client->timeout_resend);
808
809 r = sd_event_add_time(client->event,
810 &client->timeout_resend,
811 clock_boottime_or_monotonic(),
812 next_timeout, 10 * USEC_PER_MSEC,
813 client_timeout_resend, client);
814 if (r < 0)
815 goto error;
816
817 r = sd_event_source_set_priority(client->timeout_resend,
818 client->event_priority);
819 if (r < 0)
820 goto error;
821
822 r = sd_event_source_set_description(client->timeout_resend, "dhcp4-resend-timer");
823 if (r < 0)
824 goto error;
825
826 switch (client->state) {
827 case DHCP_STATE_INIT:
828 r = client_send_discover(client);
829 if (r >= 0) {
830 client->state = DHCP_STATE_SELECTING;
831 client->attempt = 1;
832 } else {
833 if (client->attempt >= 64)
834 goto error;
835 }
836
837 break;
838
839 case DHCP_STATE_SELECTING:
840 r = client_send_discover(client);
841 if (r < 0 && client->attempt >= 64)
842 goto error;
843
844 break;
845
846 case DHCP_STATE_INIT_REBOOT:
847 case DHCP_STATE_REQUESTING:
848 case DHCP_STATE_RENEWING:
849 case DHCP_STATE_REBINDING:
850 r = client_send_request(client);
851 if (r < 0 && client->attempt >= 64)
852 goto error;
853
854 if (client->state == DHCP_STATE_INIT_REBOOT)
855 client->state = DHCP_STATE_REBOOTING;
856
857 client->request_sent = time_now;
858
859 break;
860
861 case DHCP_STATE_REBOOTING:
862 case DHCP_STATE_BOUND:
863
864 break;
865
866 case DHCP_STATE_STOPPED:
867 r = -EINVAL;
868 goto error;
869 }
870
871 return 0;
872
873 error:
874 client_stop(client, r);
875
876 /* Errors were dealt with when stopping the client, don't spill
877 errors into the event loop handler */
878 return 0;
879 }
880
881 static int client_initialize_io_events(sd_dhcp_client *client,
882 sd_event_io_handler_t io_callback) {
883 int r;
884
885 assert(client);
886 assert(client->event);
887
888 r = sd_event_add_io(client->event, &client->receive_message,
889 client->fd, EPOLLIN, io_callback,
890 client);
891 if (r < 0)
892 goto error;
893
894 r = sd_event_source_set_priority(client->receive_message,
895 client->event_priority);
896 if (r < 0)
897 goto error;
898
899 r = sd_event_source_set_description(client->receive_message, "dhcp4-receive-message");
900 if (r < 0)
901 goto error;
902
903 error:
904 if (r < 0)
905 client_stop(client, r);
906
907 return 0;
908 }
909
910 static int client_initialize_time_events(sd_dhcp_client *client) {
911 int r;
912
913 assert(client);
914 assert(client->event);
915
916 client->timeout_resend = sd_event_source_unref(client->timeout_resend);
917
918 r = sd_event_add_time(client->event,
919 &client->timeout_resend,
920 clock_boottime_or_monotonic(),
921 0, 0,
922 client_timeout_resend, client);
923 if (r < 0)
924 goto error;
925
926 r = sd_event_source_set_priority(client->timeout_resend,
927 client->event_priority);
928 if (r < 0)
929 goto error;
930
931 r = sd_event_source_set_description(client->timeout_resend, "dhcp4-resend-timer");
932 if (r < 0)
933 goto error;
934
935 error:
936 if (r < 0)
937 client_stop(client, r);
938
939 return 0;
940
941 }
942
943 static int client_initialize_events(sd_dhcp_client *client,
944 sd_event_io_handler_t io_callback) {
945 client_initialize_io_events(client, io_callback);
946 client_initialize_time_events(client);
947
948 return 0;
949 }
950
951 static int client_start(sd_dhcp_client *client) {
952 int r;
953
954 assert_return(client, -EINVAL);
955 assert_return(client->event, -EINVAL);
956 assert_return(client->index > 0, -EINVAL);
957 assert_return(client->fd < 0, -EBUSY);
958 assert_return(client->xid == 0, -EINVAL);
959 assert_return(client->state == DHCP_STATE_INIT ||
960 client->state == DHCP_STATE_INIT_REBOOT, -EBUSY);
961
962 client->xid = random_u32();
963
964 r = dhcp_network_bind_raw_socket(client->index, &client->link,
965 client->xid, client->mac_addr,
966 client->mac_addr_len, client->arp_type);
967 if (r < 0) {
968 client_stop(client, r);
969 return r;
970 }
971 client->fd = r;
972
973 if (client->state == DHCP_STATE_INIT || client->state == DHCP_STATE_INIT_REBOOT)
974 client->start_time = now(clock_boottime_or_monotonic());
975
976 return client_initialize_events(client, client_receive_message_raw);
977 }
978
979 static int client_timeout_expire(sd_event_source *s, uint64_t usec,
980 void *userdata) {
981 sd_dhcp_client *client = userdata;
982 DHCP_CLIENT_DONT_DESTROY(client);
983
984 log_dhcp_client(client, "EXPIRED");
985
986 client_notify(client, DHCP_EVENT_EXPIRED);
987
988 /* lease was lost, start over if not freed or stopped in callback */
989 if (client->state != DHCP_STATE_STOPPED) {
990 client_initialize(client);
991 client_start(client);
992 }
993
994 return 0;
995 }
996
997 static int client_timeout_t2(sd_event_source *s, uint64_t usec, void *userdata) {
998 sd_dhcp_client *client = userdata;
999 DHCP_CLIENT_DONT_DESTROY(client);
1000 int r;
1001
1002 client->receive_message = sd_event_source_unref(client->receive_message);
1003 client->fd = asynchronous_close(client->fd);
1004
1005 client->state = DHCP_STATE_REBINDING;
1006 client->attempt = 1;
1007
1008 r = dhcp_network_bind_raw_socket(client->index, &client->link,
1009 client->xid, client->mac_addr,
1010 client->mac_addr_len, client->arp_type);
1011 if (r < 0) {
1012 client_stop(client, r);
1013 return 0;
1014 }
1015 client->fd = r;
1016
1017 return client_initialize_events(client, client_receive_message_raw);
1018 }
1019
1020 static int client_timeout_t1(sd_event_source *s, uint64_t usec,
1021 void *userdata) {
1022 sd_dhcp_client *client = userdata;
1023 DHCP_CLIENT_DONT_DESTROY(client);
1024
1025 client->state = DHCP_STATE_RENEWING;
1026 client->attempt = 1;
1027
1028 return client_initialize_time_events(client);
1029 }
1030
1031 static int client_handle_offer(sd_dhcp_client *client, DHCPMessage *offer,
1032 size_t len) {
1033 _cleanup_dhcp_lease_unref_ sd_dhcp_lease *lease = NULL;
1034 int r;
1035
1036 r = dhcp_lease_new(&lease);
1037 if (r < 0)
1038 return r;
1039
1040 if (client->client_id_len) {
1041 r = dhcp_lease_set_client_id(lease,
1042 (uint8_t *) &client->client_id,
1043 client->client_id_len);
1044 if (r < 0)
1045 return r;
1046 }
1047
1048 r = dhcp_option_parse(offer, len, dhcp_lease_parse_options, lease);
1049 if (r != DHCP_OFFER) {
1050 log_dhcp_client(client, "received message was not an OFFER, ignoring");
1051 return -ENOMSG;
1052 }
1053
1054 lease->next_server = offer->siaddr;
1055 lease->address = offer->yiaddr;
1056
1057 if (lease->address == 0 ||
1058 lease->server_address == 0 ||
1059 lease->lifetime == 0) {
1060 log_dhcp_client(client, "received lease lacks address, server address or lease lifetime, ignoring");
1061 return -ENOMSG;
1062 }
1063
1064 if (!lease->have_subnet_mask) {
1065 r = dhcp_lease_set_default_subnet_mask(lease);
1066 if (r < 0) {
1067 log_dhcp_client(client, "received lease lacks subnet "
1068 "mask, and a fallback one can not be "
1069 "generated, ignoring");
1070 return -ENOMSG;
1071 }
1072 }
1073
1074 sd_dhcp_lease_unref(client->lease);
1075 client->lease = lease;
1076 lease = NULL;
1077
1078 log_dhcp_client(client, "OFFER");
1079
1080 return 0;
1081 }
1082
1083 static int client_handle_forcerenew(sd_dhcp_client *client, DHCPMessage *force,
1084 size_t len) {
1085 int r;
1086
1087 r = dhcp_option_parse(force, len, NULL, NULL);
1088 if (r != DHCP_FORCERENEW)
1089 return -ENOMSG;
1090
1091 log_dhcp_client(client, "FORCERENEW");
1092
1093 return 0;
1094 }
1095
1096 static int client_handle_ack(sd_dhcp_client *client, DHCPMessage *ack,
1097 size_t len) {
1098 _cleanup_dhcp_lease_unref_ sd_dhcp_lease *lease = NULL;
1099 int r;
1100
1101 r = dhcp_lease_new(&lease);
1102 if (r < 0)
1103 return r;
1104
1105 if (client->client_id_len) {
1106 r = dhcp_lease_set_client_id(lease,
1107 (uint8_t *) &client->client_id,
1108 client->client_id_len);
1109 if (r < 0)
1110 return r;
1111 }
1112
1113 r = dhcp_option_parse(ack, len, dhcp_lease_parse_options, lease);
1114 if (r == DHCP_NAK) {
1115 log_dhcp_client(client, "NAK");
1116 return -EADDRNOTAVAIL;
1117 }
1118
1119 if (r != DHCP_ACK) {
1120 log_dhcp_client(client, "received message was not an ACK, ignoring");
1121 return -ENOMSG;
1122 }
1123
1124 lease->next_server = ack->siaddr;
1125
1126 lease->address = ack->yiaddr;
1127
1128 if (lease->address == INADDR_ANY ||
1129 lease->server_address == INADDR_ANY ||
1130 lease->lifetime == 0) {
1131 log_dhcp_client(client, "received lease lacks address, server "
1132 "address or lease lifetime, ignoring");
1133 return -ENOMSG;
1134 }
1135
1136 if (lease->subnet_mask == INADDR_ANY) {
1137 r = dhcp_lease_set_default_subnet_mask(lease);
1138 if (r < 0) {
1139 log_dhcp_client(client, "received lease lacks subnet "
1140 "mask, and a fallback one can not be "
1141 "generated, ignoring");
1142 return -ENOMSG;
1143 }
1144 }
1145
1146 r = DHCP_EVENT_IP_ACQUIRE;
1147 if (client->lease) {
1148 if (client->lease->address != lease->address ||
1149 client->lease->subnet_mask != lease->subnet_mask ||
1150 client->lease->router != lease->router) {
1151 r = DHCP_EVENT_IP_CHANGE;
1152 } else
1153 r = DHCP_EVENT_RENEW;
1154
1155 client->lease = sd_dhcp_lease_unref(client->lease);
1156 }
1157
1158 client->lease = lease;
1159 lease = NULL;
1160
1161 log_dhcp_client(client, "ACK");
1162
1163 return r;
1164 }
1165
1166 static uint64_t client_compute_timeout(sd_dhcp_client *client, uint32_t lifetime, double factor) {
1167 assert(client);
1168 assert(client->request_sent);
1169 assert(lifetime > 0);
1170
1171 if (lifetime > 3)
1172 lifetime -= 3;
1173 else
1174 lifetime = 0;
1175
1176 return client->request_sent + (lifetime * USEC_PER_SEC * factor) +
1177 + (random_u32() & 0x1fffff);
1178 }
1179
1180 static int client_set_lease_timeouts(sd_dhcp_client *client) {
1181 usec_t time_now;
1182 uint64_t lifetime_timeout;
1183 uint64_t t2_timeout;
1184 uint64_t t1_timeout;
1185 char time_string[FORMAT_TIMESPAN_MAX];
1186 int r;
1187
1188 assert(client);
1189 assert(client->event);
1190 assert(client->lease);
1191 assert(client->lease->lifetime);
1192
1193 client->timeout_t1 = sd_event_source_unref(client->timeout_t1);
1194 client->timeout_t2 = sd_event_source_unref(client->timeout_t2);
1195 client->timeout_expire = sd_event_source_unref(client->timeout_expire);
1196
1197 /* don't set timers for infinite leases */
1198 if (client->lease->lifetime == 0xffffffff)
1199 return 0;
1200
1201 r = sd_event_now(client->event, clock_boottime_or_monotonic(), &time_now);
1202 if (r < 0)
1203 return r;
1204 assert(client->request_sent <= time_now);
1205
1206 /* convert the various timeouts from relative (secs) to absolute (usecs) */
1207 lifetime_timeout = client_compute_timeout(client, client->lease->lifetime, 1);
1208 if (client->lease->t1 > 0 && client->lease->t2 > 0) {
1209 /* both T1 and T2 are given */
1210 if (client->lease->t1 < client->lease->t2 &&
1211 client->lease->t2 < client->lease->lifetime) {
1212 /* they are both valid */
1213 t2_timeout = client_compute_timeout(client, client->lease->t2, 1);
1214 t1_timeout = client_compute_timeout(client, client->lease->t1, 1);
1215 } else {
1216 /* discard both */
1217 t2_timeout = client_compute_timeout(client, client->lease->lifetime, 7.0 / 8.0);
1218 client->lease->t2 = (client->lease->lifetime * 7) / 8;
1219 t1_timeout = client_compute_timeout(client, client->lease->lifetime, 0.5);
1220 client->lease->t1 = client->lease->lifetime / 2;
1221 }
1222 } else if (client->lease->t2 > 0 && client->lease->t2 < client->lease->lifetime) {
1223 /* only T2 is given, and it is valid */
1224 t2_timeout = client_compute_timeout(client, client->lease->t2, 1);
1225 t1_timeout = client_compute_timeout(client, client->lease->lifetime, 0.5);
1226 client->lease->t1 = client->lease->lifetime / 2;
1227 if (t2_timeout <= t1_timeout) {
1228 /* the computed T1 would be invalid, so discard T2 */
1229 t2_timeout = client_compute_timeout(client, client->lease->lifetime, 7.0 / 8.0);
1230 client->lease->t2 = (client->lease->lifetime * 7) / 8;
1231 }
1232 } else if (client->lease->t1 > 0 && client->lease->t1 < client->lease->lifetime) {
1233 /* only T1 is given, and it is valid */
1234 t1_timeout = client_compute_timeout(client, client->lease->t1, 1);
1235 t2_timeout = client_compute_timeout(client, client->lease->lifetime, 7.0 / 8.0);
1236 client->lease->t2 = (client->lease->lifetime * 7) / 8;
1237 if (t2_timeout <= t1_timeout) {
1238 /* the computed T2 would be invalid, so discard T1 */
1239 t2_timeout = client_compute_timeout(client, client->lease->lifetime, 0.5);
1240 client->lease->t2 = client->lease->lifetime / 2;
1241 }
1242 } else {
1243 /* fall back to the default timeouts */
1244 t1_timeout = client_compute_timeout(client, client->lease->lifetime, 0.5);
1245 client->lease->t1 = client->lease->lifetime / 2;
1246 t2_timeout = client_compute_timeout(client, client->lease->lifetime, 7.0 / 8.0);
1247 client->lease->t2 = (client->lease->lifetime * 7) / 8;
1248 }
1249
1250 /* arm lifetime timeout */
1251 r = sd_event_add_time(client->event, &client->timeout_expire,
1252 clock_boottime_or_monotonic(),
1253 lifetime_timeout, 10 * USEC_PER_MSEC,
1254 client_timeout_expire, client);
1255 if (r < 0)
1256 return r;
1257
1258 r = sd_event_source_set_priority(client->timeout_expire,
1259 client->event_priority);
1260 if (r < 0)
1261 return r;
1262
1263 r = sd_event_source_set_description(client->timeout_expire, "dhcp4-lifetime");
1264 if (r < 0)
1265 return r;
1266
1267 log_dhcp_client(client, "lease expires in %s",
1268 format_timespan(time_string, FORMAT_TIMESPAN_MAX,
1269 lifetime_timeout - time_now, 0));
1270
1271 /* don't arm earlier timeouts if this has already expired */
1272 if (lifetime_timeout <= time_now)
1273 return 0;
1274
1275 /* arm T2 timeout */
1276 r = sd_event_add_time(client->event,
1277 &client->timeout_t2,
1278 clock_boottime_or_monotonic(),
1279 t2_timeout,
1280 10 * USEC_PER_MSEC,
1281 client_timeout_t2, client);
1282 if (r < 0)
1283 return r;
1284
1285 r = sd_event_source_set_priority(client->timeout_t2,
1286 client->event_priority);
1287 if (r < 0)
1288 return r;
1289
1290 r = sd_event_source_set_description(client->timeout_t2, "dhcp4-t2-timeout");
1291 if (r < 0)
1292 return r;
1293
1294 log_dhcp_client(client, "T2 expires in %s",
1295 format_timespan(time_string, FORMAT_TIMESPAN_MAX,
1296 t2_timeout - time_now, 0));
1297
1298 /* don't arm earlier timeout if this has already expired */
1299 if (t2_timeout <= time_now)
1300 return 0;
1301
1302 /* arm T1 timeout */
1303 r = sd_event_add_time(client->event,
1304 &client->timeout_t1,
1305 clock_boottime_or_monotonic(),
1306 t1_timeout, 10 * USEC_PER_MSEC,
1307 client_timeout_t1, client);
1308 if (r < 0)
1309 return r;
1310
1311 r = sd_event_source_set_priority(client->timeout_t1,
1312 client->event_priority);
1313 if (r < 0)
1314 return r;
1315
1316 r = sd_event_source_set_description(client->timeout_t1, "dhcp4-t1-timer");
1317 if (r < 0)
1318 return r;
1319
1320 log_dhcp_client(client, "T1 expires in %s",
1321 format_timespan(time_string, FORMAT_TIMESPAN_MAX,
1322 t1_timeout - time_now, 0));
1323
1324 return 0;
1325 }
1326
1327 static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message,
1328 int len) {
1329 DHCP_CLIENT_DONT_DESTROY(client);
1330 int r = 0, notify_event = 0;
1331
1332 assert(client);
1333 assert(client->event);
1334 assert(message);
1335
1336 switch (client->state) {
1337 case DHCP_STATE_SELECTING:
1338
1339 r = client_handle_offer(client, message, len);
1340 if (r >= 0) {
1341
1342 client->timeout_resend =
1343 sd_event_source_unref(client->timeout_resend);
1344
1345 client->state = DHCP_STATE_REQUESTING;
1346 client->attempt = 1;
1347
1348 r = sd_event_add_time(client->event,
1349 &client->timeout_resend,
1350 clock_boottime_or_monotonic(),
1351 0, 0,
1352 client_timeout_resend, client);
1353 if (r < 0)
1354 goto error;
1355
1356 r = sd_event_source_set_priority(client->timeout_resend,
1357 client->event_priority);
1358 if (r < 0)
1359 goto error;
1360
1361 r = sd_event_source_set_description(client->timeout_resend, "dhcp4-resend-timer");
1362 if (r < 0)
1363 goto error;
1364 } else if (r == -ENOMSG)
1365 /* invalid message, let's ignore it */
1366 return 0;
1367
1368 break;
1369
1370 case DHCP_STATE_REBOOTING:
1371 case DHCP_STATE_REQUESTING:
1372 case DHCP_STATE_RENEWING:
1373 case DHCP_STATE_REBINDING:
1374
1375 r = client_handle_ack(client, message, len);
1376 if (r >= 0) {
1377 client->timeout_resend =
1378 sd_event_source_unref(client->timeout_resend);
1379 client->receive_message =
1380 sd_event_source_unref(client->receive_message);
1381 client->fd = asynchronous_close(client->fd);
1382
1383 if (IN_SET(client->state, DHCP_STATE_REQUESTING,
1384 DHCP_STATE_REBOOTING))
1385 notify_event = DHCP_EVENT_IP_ACQUIRE;
1386 else if (r != DHCP_EVENT_IP_ACQUIRE)
1387 notify_event = r;
1388
1389 client->state = DHCP_STATE_BOUND;
1390 client->attempt = 1;
1391
1392 client->last_addr = client->lease->address;
1393
1394 r = client_set_lease_timeouts(client);
1395 if (r < 0) {
1396 log_dhcp_client(client, "could not set lease timeouts");
1397 goto error;
1398 }
1399
1400 r = dhcp_network_bind_udp_socket(client->lease->address,
1401 DHCP_PORT_CLIENT);
1402 if (r < 0) {
1403 log_dhcp_client(client, "could not bind UDP socket");
1404 goto error;
1405 }
1406
1407 client->fd = r;
1408
1409 client_initialize_io_events(client, client_receive_message_udp);
1410
1411 if (notify_event) {
1412 client_notify(client, notify_event);
1413 if (client->state == DHCP_STATE_STOPPED)
1414 return 0;
1415 }
1416
1417 } else if (r == -EADDRNOTAVAIL) {
1418 /* got a NAK, let's restart the client */
1419 client->timeout_resend =
1420 sd_event_source_unref(client->timeout_resend);
1421
1422 r = client_initialize(client);
1423 if (r < 0)
1424 goto error;
1425
1426 r = client_start(client);
1427 if (r < 0)
1428 goto error;
1429
1430 log_dhcp_client(client, "REBOOTED");
1431
1432 return 0;
1433 } else if (r == -ENOMSG)
1434 /* invalid message, let's ignore it */
1435 return 0;
1436
1437 break;
1438
1439 case DHCP_STATE_BOUND:
1440 r = client_handle_forcerenew(client, message, len);
1441 if (r >= 0) {
1442 r = client_timeout_t1(NULL, 0, client);
1443 if (r < 0)
1444 goto error;
1445 } else if (r == -ENOMSG)
1446 /* invalid message, let's ignore it */
1447 return 0;
1448
1449 break;
1450
1451 case DHCP_STATE_INIT:
1452 case DHCP_STATE_INIT_REBOOT:
1453
1454 break;
1455
1456 case DHCP_STATE_STOPPED:
1457 r = -EINVAL;
1458 goto error;
1459 }
1460
1461 error:
1462 if (r < 0)
1463 client_stop(client, r);
1464
1465 return r;
1466 }
1467
1468 static int client_receive_message_udp(sd_event_source *s, int fd,
1469 uint32_t revents, void *userdata) {
1470 sd_dhcp_client *client = userdata;
1471 _cleanup_free_ DHCPMessage *message = NULL;
1472 int buflen = 0, len, r;
1473 const struct ether_addr zero_mac = { { 0, 0, 0, 0, 0, 0 } };
1474 const struct ether_addr *expected_chaddr = NULL;
1475 uint8_t expected_hlen = 0;
1476
1477 assert(s);
1478 assert(client);
1479
1480 r = ioctl(fd, FIONREAD, &buflen);
1481 if (r < 0)
1482 return r;
1483
1484 if (buflen < 0)
1485 /* this can't be right */
1486 return -EIO;
1487
1488 message = malloc0(buflen);
1489 if (!message)
1490 return -ENOMEM;
1491
1492 len = read(fd, message, buflen);
1493 if (len < 0) {
1494 log_dhcp_client(client, "could not receive message from UDP "
1495 "socket: %m");
1496 return 0;
1497 } else if ((size_t)len < sizeof(DHCPMessage)) {
1498 log_dhcp_client(client, "too small to be a DHCP message: ignoring");
1499 return 0;
1500 }
1501
1502 if (be32toh(message->magic) != DHCP_MAGIC_COOKIE) {
1503 log_dhcp_client(client, "not a DHCP message: ignoring");
1504 return 0;
1505 }
1506
1507 if (message->op != BOOTREPLY) {
1508 log_dhcp_client(client, "not a BOOTREPLY message: ignoring");
1509 return 0;
1510 }
1511
1512 if (message->htype != client->arp_type) {
1513 log_dhcp_client(client, "packet type does not match client type");
1514 return 0;
1515 }
1516
1517 if (client->arp_type == ARPHRD_ETHER) {
1518 expected_hlen = ETH_ALEN;
1519 expected_chaddr = (const struct ether_addr *) &client->mac_addr;
1520 } else {
1521 /* Non-ethernet links expect zero chaddr */
1522 expected_hlen = 0;
1523 expected_chaddr = &zero_mac;
1524 }
1525
1526 if (message->hlen != expected_hlen) {
1527 log_dhcp_client(client, "unexpected packet hlen %d", message->hlen);
1528 return 0;
1529 }
1530
1531 if (memcmp(&message->chaddr[0], expected_chaddr, ETH_ALEN)) {
1532 log_dhcp_client(client, "received chaddr does not match "
1533 "expected: ignoring");
1534 return 0;
1535 }
1536
1537 if (client->state != DHCP_STATE_BOUND &&
1538 be32toh(message->xid) != client->xid) {
1539 /* in BOUND state, we may receive FORCERENEW with xid set by server,
1540 so ignore the xid in this case */
1541 log_dhcp_client(client, "received xid (%u) does not match "
1542 "expected (%u): ignoring",
1543 be32toh(message->xid), client->xid);
1544 return 0;
1545 }
1546
1547 return client_handle_message(client, message, len);
1548 }
1549
1550 static int client_receive_message_raw(sd_event_source *s, int fd,
1551 uint32_t revents, void *userdata) {
1552 sd_dhcp_client *client = userdata;
1553 _cleanup_free_ DHCPPacket *packet = NULL;
1554 uint8_t cmsgbuf[CMSG_LEN(sizeof(struct tpacket_auxdata))];
1555 struct iovec iov = {};
1556 struct msghdr msg = {
1557 .msg_iov = &iov,
1558 .msg_iovlen = 1,
1559 .msg_control = cmsgbuf,
1560 .msg_controllen = sizeof(cmsgbuf),
1561 };
1562 struct cmsghdr *cmsg;
1563 bool checksum = true;
1564 int buflen = 0, len, r;
1565
1566 assert(s);
1567 assert(client);
1568
1569 r = ioctl(fd, FIONREAD, &buflen);
1570 if (r < 0)
1571 return r;
1572
1573 if (buflen < 0)
1574 /* this can't be right */
1575 return -EIO;
1576
1577 packet = malloc0(buflen);
1578 if (!packet)
1579 return -ENOMEM;
1580
1581 iov.iov_base = packet;
1582 iov.iov_len = buflen;
1583
1584 len = recvmsg(fd, &msg, 0);
1585 if (len < 0) {
1586 log_dhcp_client(client, "could not receive message from raw "
1587 "socket: %m");
1588 return 0;
1589 } else if ((size_t)len < sizeof(DHCPPacket))
1590 return 0;
1591
1592 CMSG_FOREACH(cmsg, &msg) {
1593 if (cmsg->cmsg_level == SOL_PACKET &&
1594 cmsg->cmsg_type == PACKET_AUXDATA &&
1595 cmsg->cmsg_len == CMSG_LEN(sizeof(struct tpacket_auxdata))) {
1596 struct tpacket_auxdata *aux = (struct tpacket_auxdata*)CMSG_DATA(cmsg);
1597
1598 checksum = !(aux->tp_status & TP_STATUS_CSUMNOTREADY);
1599 break;
1600 }
1601 }
1602
1603 r = dhcp_packet_verify_headers(packet, len, checksum);
1604 if (r < 0)
1605 return 0;
1606
1607 len -= DHCP_IP_UDP_SIZE;
1608
1609 return client_handle_message(client, &packet->dhcp, len);
1610 }
1611
1612 int sd_dhcp_client_start(sd_dhcp_client *client) {
1613 int r;
1614
1615 assert_return(client, -EINVAL);
1616
1617 r = client_initialize(client);
1618 if (r < 0)
1619 return r;
1620
1621 if (client->last_addr)
1622 client->state = DHCP_STATE_INIT_REBOOT;
1623
1624 r = client_start(client);
1625 if (r >= 0)
1626 log_dhcp_client(client, "STARTED on ifindex %i", client->index);
1627
1628 return r;
1629 }
1630
1631 int sd_dhcp_client_stop(sd_dhcp_client *client) {
1632 DHCP_CLIENT_DONT_DESTROY(client);
1633
1634 assert_return(client, -EINVAL);
1635
1636 client_stop(client, DHCP_EVENT_STOP);
1637 client->state = DHCP_STATE_STOPPED;
1638
1639 return 0;
1640 }
1641
1642 int sd_dhcp_client_attach_event(sd_dhcp_client *client, sd_event *event,
1643 int priority) {
1644 int r;
1645
1646 assert_return(client, -EINVAL);
1647 assert_return(!client->event, -EBUSY);
1648
1649 if (event)
1650 client->event = sd_event_ref(event);
1651 else {
1652 r = sd_event_default(&client->event);
1653 if (r < 0)
1654 return 0;
1655 }
1656
1657 client->event_priority = priority;
1658
1659 return 0;
1660 }
1661
1662 int sd_dhcp_client_detach_event(sd_dhcp_client *client) {
1663 assert_return(client, -EINVAL);
1664
1665 client->event = sd_event_unref(client->event);
1666
1667 return 0;
1668 }
1669
1670 sd_event *sd_dhcp_client_get_event(sd_dhcp_client *client) {
1671 if (!client)
1672 return NULL;
1673
1674 return client->event;
1675 }
1676
1677 sd_dhcp_client *sd_dhcp_client_ref(sd_dhcp_client *client) {
1678
1679 if (!client)
1680 return NULL;
1681
1682 assert(client->n_ref >= 1);
1683 client->n_ref++;
1684
1685 return client;
1686 }
1687
1688 sd_dhcp_client *sd_dhcp_client_unref(sd_dhcp_client *client) {
1689
1690 if (!client)
1691 return NULL;
1692
1693 assert(client->n_ref >= 1);
1694 client->n_ref--;
1695
1696 if (client->n_ref > 0)
1697 return NULL;
1698
1699 log_dhcp_client(client, "FREE");
1700
1701 client_initialize(client);
1702
1703 client->receive_message = sd_event_source_unref(client->receive_message);
1704
1705 sd_dhcp_client_detach_event(client);
1706
1707 sd_dhcp_lease_unref(client->lease);
1708
1709 free(client->req_opts);
1710 free(client->hostname);
1711 free(client->vendor_class_identifier);
1712 free(client);
1713
1714 return NULL;
1715 }
1716
1717 int sd_dhcp_client_new(sd_dhcp_client **ret) {
1718 _cleanup_dhcp_client_unref_ sd_dhcp_client *client = NULL;
1719
1720 assert_return(ret, -EINVAL);
1721
1722 client = new0(sd_dhcp_client, 1);
1723 if (!client)
1724 return -ENOMEM;
1725
1726 client->n_ref = 1;
1727 client->state = DHCP_STATE_INIT;
1728 client->index = -1;
1729 client->fd = -1;
1730 client->attempt = 1;
1731 client->mtu = DHCP_DEFAULT_MIN_SIZE;
1732
1733 client->req_opts_size = ELEMENTSOF(default_req_opts);
1734
1735 client->req_opts = memdup(default_req_opts, client->req_opts_size);
1736 if (!client->req_opts)
1737 return -ENOMEM;
1738
1739 *ret = client;
1740 client = NULL;
1741
1742 return 0;
1743 }
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