dhclient - Add 6-byte MAC address to the log entries for DHCP ACK/NAK/OFFER.
[dragonfly.git] / sbin / dhclient / dhclient.c
CommitLineData
bdf60627 1/* $OpenBSD: src/sbin/dhclient/dhclient.c,v 1.124 2009/03/10 23:19:36 krw Exp $ */
846204b6
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2
3/*
4 * Copyright 2004 Henning Brauer <henning@openbsd.org>
5 * Copyright (c) 1995, 1996, 1997, 1998, 1999
6 * The Internet Software Consortium. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of The Internet Software Consortium nor the names
18 * of its contributors may be used to endorse or promote products derived
19 * from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
22 * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
23 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
25 * DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
26 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
27 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
28 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
29 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
30 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
31 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
32 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * This software has been written for the Internet Software Consortium
36 * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
37 * Enterprises. To learn more about the Internet Software Consortium,
38 * see ``http://www.vix.com/isc''. To learn more about Vixie
39 * Enterprises, see ``http://www.vix.com''.
40 *
41 * This client was substantially modified and enhanced by Elliot Poger
42 * for use on Linux while he was working on the MosquitoNet project at
43 * Stanford.
44 *
45 * The current version owes much to Elliot's Linux enhancements, but
46 * was substantially reorganized and partially rewritten by Ted Lemon
47 * so as to use the same networking framework that the Internet Software
48 * Consortium DHCP server uses. Much system-specific configuration code
49 * was moved into a shell script so that as support for more operating
50 * systems is added, it will not be necessary to port and maintain
51 * system-specific configuration code to these operating systems - instead,
52 * the shell script can invoke the native tools to accomplish the same
53 * purpose.
54 */
55
56#include <ctype.h>
57#include <poll.h>
58#include <pwd.h>
a05d48e6 59#include <unistd.h>
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60
61#include "dhcpd.h"
62#include "privsep.h"
63
64#define CLIENT_PATH "PATH=/usr/bin:/usr/sbin:/bin:/sbin"
65#define DEFAULT_LEASE_TIME 43200 /* 12 hours... */
66#define TIME_MAX 2147483647
a05d48e6
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67#define POLL_FAILURES 10
68#define POLL_FAILURE_WAIT 1 /* Back off multiplier (seconds) */
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69
70time_t cur_time;
71
72char *path_dhclient_conf = _PATH_DHCLIENT_CONF;
73char *path_dhclient_db = NULL;
74
75int log_perror = 1;
76int privfd;
77int nullfd = -1;
78int no_daemon;
79int unknown_ok = 1;
80int routefd = -1;
81
82struct iaddr iaddr_broadcast = { 4, { 255, 255, 255, 255 } };
83struct in_addr inaddr_any;
84struct sockaddr_in sockaddr_broadcast;
85
86struct interface_info *ifi;
87struct client_state *client;
88struct client_config *config;
89
90int findproto(char *, int);
91struct sockaddr *get_ifa(char *, int);
92void usage(void);
93int check_option(struct client_lease *l, int option);
94int ipv4addrs(char * buf);
95int res_hnok(const char *dn);
96char *option_as_string(unsigned int code, unsigned char *data, int len);
97int fork_privchld(int, int);
98
99#define ROUNDUP(a) \
100 ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
101#define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))
102
103time_t scripttime;
104static FILE *leaseFile;
105
106int
107findproto(char *cp, int n)
108{
109 struct sockaddr *sa;
110 int i;
111
112 if (n == 0)
113 return -1;
114 for (i = 1; i; i <<= 1) {
115 if (i & n) {
116 sa = (struct sockaddr *)cp;
117 switch (i) {
118 case RTA_IFA:
119 case RTA_DST:
120 case RTA_GATEWAY:
121 case RTA_NETMASK:
122 if (sa->sa_family == AF_INET)
123 return AF_INET;
124 if (sa->sa_family == AF_INET6)
125 return AF_INET6;
126 break;
127 case RTA_IFP:
128 break;
129 }
130 ADVANCE(cp, sa);
131 }
132 }
133 return (-1);
134}
135
136struct sockaddr *
137get_ifa(char *cp, int n)
138{
139 struct sockaddr *sa;
140 int i;
141
142 if (n == 0)
143 return (NULL);
144 for (i = 1; i; i <<= 1)
145 if (i & n) {
146 sa = (struct sockaddr *)cp;
147 if (i == RTA_IFA)
148 return (sa);
149 ADVANCE(cp, sa);
150 }
151
152 return (NULL);
153}
be18cf74 154struct iaddr defaddr = { .len = 4 }; /* NULL is for silence warnings */
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155
156/* ARGSUSED */
157void
158routehandler(void)
159{
160 int linkstat;
161 char msg[2048];
162 struct rt_msghdr *rtm;
163 struct if_msghdr *ifm;
164 struct ifa_msghdr *ifam;
165 struct if_announcemsghdr *ifan;
166 struct client_lease *l;
167 time_t t = time(NULL);
168 struct sockaddr *sa;
169 struct iaddr a;
170 ssize_t n;
171
172 do {
173 n = read(routefd, &msg, sizeof(msg));
174 } while (n == -1 && errno == EINTR);
175
176 rtm = (struct rt_msghdr *)msg;
177 if (n < sizeof(rtm->rtm_msglen) || n < rtm->rtm_msglen ||
178 rtm->rtm_version != RTM_VERSION)
179 return;
180
181 switch (rtm->rtm_type) {
182 case RTM_NEWADDR:
183 ifam = (struct ifa_msghdr *)rtm;
184 if (ifam->ifam_index != ifi->index)
185 break;
186 if (findproto((char *)(ifam + 1), ifam->ifam_addrs) != AF_INET)
187 break;
188 sa = get_ifa((char *)(ifam + 1), ifam->ifam_addrs);
189 if (sa == NULL)
190 goto die;
191
192 if ((a.len = sizeof(struct in_addr)) > sizeof(a.iabuf))
193 error("king bula sez: len mismatch");
194 memcpy(a.iabuf, &((struct sockaddr_in *)sa)->sin_addr, a.len);
195 if (addr_eq(a, defaddr))
196 break;
197
198 for (l = client->active; l != NULL; l = l->next)
199 if (addr_eq(a, l->address))
200 break;
201
202 if (l != NULL || (client->alias &&
203 addr_eq(a, client->alias->address)))
204 /* new addr is the one we set */
205 break;
206
207 goto die;
208 case RTM_DELADDR:
209 ifam = (struct ifa_msghdr *)rtm;
210 if (ifam->ifam_index != ifi->index)
211 break;
212 if (findproto((char *)(ifam + 1), ifam->ifam_addrs) != AF_INET)
213 break;
214 if (scripttime == 0 || t < scripttime + 10)
215 break;
216 goto die;
217 case RTM_IFINFO:
218 ifm = (struct if_msghdr *)rtm;
219 if (ifm->ifm_index != ifi->index)
220 break;
221 if ((rtm->rtm_flags & RTF_UP) == 0)
222 goto die;
223
224 linkstat =
225 LINK_STATE_IS_UP(ifm->ifm_data.ifi_link_state) ? 1 : 0;
226 if (linkstat != ifi->linkstat) {
227 debug("link state %s -> %s",
228 ifi->linkstat ? "up" : "down",
229 linkstat ? "up" : "down");
230 ifi->linkstat = interface_link_status(ifi->name);
231 if (ifi->linkstat) {
232 client->state = S_INIT;
233 state_reboot();
234 }
235 }
236 break;
237 case RTM_IFANNOUNCE:
238 ifan = (struct if_announcemsghdr *)rtm;
239 if (ifan->ifan_what == IFAN_DEPARTURE &&
240 ifan->ifan_index == ifi->index)
241 goto die;
242 break;
243 default:
244 break;
245 }
246 return;
247
248die:
249 script_init("FAIL", NULL);
250 if (client->alias)
251 script_write_params("alias_", client->alias);
252 script_go();
253 exit(1);
254}
255
256int
257main(int argc, char *argv[])
258{
259 int ch, fd, quiet = 0, i = 0, pipe_fd[2];
260 struct passwd *pw;
261
262 /* Initially, log errors to stderr as well as to syslogd. */
263 openlog(getprogname(), LOG_PID | LOG_NDELAY, DHCPD_LOG_FACILITY);
264 setlogmask(LOG_UPTO(LOG_INFO));
265
266 while ((ch = getopt(argc, argv, "c:dl:qu")) != -1)
267 switch (ch) {
268 case 'c':
269 path_dhclient_conf = optarg;
270 break;
271 case 'd':
272 no_daemon = 1;
273 break;
274 case 'l':
275 path_dhclient_db = optarg;
276 break;
277 case 'q':
278 quiet = 1;
279 break;
280 case 'u':
281 unknown_ok = 0;
282 break;
283 default:
284 usage();
285 }
286
287 argc -= optind;
288 argv += optind;
289
290 if (argc != 1)
291 usage();
292
293 ifi = calloc(1, sizeof(*ifi));
294 if (ifi == NULL)
295 error("ifi calloc");
296 client = calloc(1, sizeof(*client));
297 if (client == NULL)
298 error("client calloc");
299 config = calloc(1, sizeof(*config));
300 if (config == NULL)
301 error("config calloc");
302
303 if (strlcpy(ifi->name, argv[0], IFNAMSIZ) >= IFNAMSIZ)
304 error("Interface name too long");
305 if (path_dhclient_db == NULL && asprintf(&path_dhclient_db, "%s.%s",
306 _PATH_DHCLIENT_DB, ifi->name) == -1)
307 error("asprintf");
308
309 if (quiet)
310 log_perror = 0;
311
312 tzset();
313 time(&cur_time);
314
315 memset(&sockaddr_broadcast, 0, sizeof(sockaddr_broadcast));
316 sockaddr_broadcast.sin_family = AF_INET;
317 sockaddr_broadcast.sin_port = htons(REMOTE_PORT);
318 sockaddr_broadcast.sin_addr.s_addr = INADDR_BROADCAST;
319 sockaddr_broadcast.sin_len = sizeof(sockaddr_broadcast);
320 inaddr_any.s_addr = INADDR_ANY;
321
322 read_client_conf();
323
324 if (interface_status(ifi->name) == 0) {
325 interface_link_forceup(ifi->name);
326 /* Give it up to 4 seconds of silent grace to find link */
327 i = -4;
328 } else
329 i = 0;
330
331 while (!(ifi->linkstat = interface_link_status(ifi->name))) {
332 if (i == 0)
333 fprintf(stderr, "%s: no link ...", ifi->name);
334 else if (i > 0)
335 fprintf(stderr, ".");
336 fflush(stderr);
337 if (++i > config->link_timeout) {
338 fprintf(stderr, " sleeping\n");
339 goto dispatch;
340 }
341 sleep(1);
846204b6 342 }
ade429c6 343 if (i > 0)
77a69a5f 344 fprintf(stderr, " got link\n");
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345
346 dispatch:
347 if ((nullfd = open(_PATH_DEVNULL, O_RDWR, 0)) == -1)
348 error("cannot open %s: %m", _PATH_DEVNULL);
349
350 if ((pw = getpwnam("_dhcp")) == NULL) {
351 warning("no such user: _dhcp, falling back to \"nobody\"");
352 if ((pw = getpwnam("nobody")) == NULL)
353 error("no such user: nobody");
354 }
355
356 if (pipe(pipe_fd) == -1)
357 error("pipe");
358
359 fork_privchld(pipe_fd[0], pipe_fd[1]);
360
361 close(pipe_fd[0]);
362 privfd = pipe_fd[1];
363
364 if ((fd = open(path_dhclient_db, O_RDONLY|O_EXLOCK|O_CREAT, 0)) == -1)
365 error("can't open and lock %s: %m", path_dhclient_db);
366 read_client_leases();
367 if ((leaseFile = fopen(path_dhclient_db, "w")) == NULL)
368 error("can't open %s: %m", path_dhclient_db);
369 rewrite_client_leases();
370 close(fd);
371
372 priv_script_init("PREINIT", NULL);
373 if (client->alias)
374 priv_script_write_params("alias_", client->alias);
375 priv_script_go();
376
377 if ((routefd = socket(PF_ROUTE, SOCK_RAW, 0)) == -1)
378 error("socket(PF_ROUTE, SOCK_RAW): %m");
379
380 /* set up the interface */
381 discover_interface();
382
383 if (chroot(_PATH_VAREMPTY) == -1)
384 error("chroot");
385 if (chdir("/") == -1)
386 error("chdir(\"/\")");
387
388 if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1)
389 error("setresgid");
390 if (setgroups(1, &pw->pw_gid) == -1)
391 error("setgroups");
392 if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1)
393 error("setresuid");
394
395 endpwent();
396
397 setproctitle("%s", ifi->name);
398
399 if (ifi->linkstat) {
400 client->state = S_INIT;
401 state_reboot();
402 } else
403 go_daemon();
404
405 dispatch();
406
407 /* not reached */
408 return (0);
409}
410
411void
412usage(void)
413{
414 fprintf(stderr, "usage: %s [-dqu] [-c file] [-l file] interface\n",
415 getprogname());
416 exit(1);
417}
418
419/*
420 * Individual States:
421 *
422 * Each routine is called from the dhclient_state_machine() in one of
423 * these conditions:
424 * -> entering INIT state
425 * -> recvpacket_flag == 0: timeout in this state
426 * -> otherwise: received a packet in this state
427 *
428 * Return conditions as handled by dhclient_state_machine():
429 * Returns 1, sendpacket_flag = 1: send packet, reset timer.
430 * Returns 1, sendpacket_flag = 0: just reset the timer (wait for a milestone).
431 * Returns 0: finish the nap which was interrupted for no good reason.
432 *
433 * Several per-interface variables are used to keep track of the process:
434 * active_lease: the lease that is being used on the interface
435 * (null pointer if not configured yet).
436 * offered_leases: leases corresponding to DHCPOFFER messages that have
437 * been sent to us by DHCP servers.
438 * acked_leases: leases corresponding to DHCPACK messages that have been
439 * sent to us by DHCP servers.
440 * sendpacket: DHCP packet we're trying to send.
441 * destination: IP address to send sendpacket to
442 * In addition, there are several relevant per-lease variables.
443 * T1_expiry, T2_expiry, lease_expiry: lease milestones
444 * In the active lease, these control the process of renewing the lease;
445 * In leases on the acked_leases list, this simply determines when we
446 * can no longer legitimately use the lease.
447 */
448void
449state_reboot(void)
450{
451 /* If we don't remember an active lease, go straight to INIT. */
452 if (!client->active || client->active->is_bootp) {
453 state_init();
454 return;
455 }
456
457 /* We are in the rebooting state. */
458 client->state = S_REBOOTING;
459
460 /* make_request doesn't initialize xid because it normally comes
461 from the DHCPDISCOVER, but we haven't sent a DHCPDISCOVER,
462 so pick an xid now. */
463 client->xid = arc4random();
464
465 /* Make a DHCPREQUEST packet, and set appropriate per-interface
466 flags. */
467 make_request(client->active);
468 client->destination = iaddr_broadcast;
469 client->first_sending = cur_time;
470 client->interval = config->initial_interval;
471
472 /* Zap the medium list... */
473 client->medium = NULL;
474
475 /* Send out the first DHCPREQUEST packet. */
476 send_request();
477}
478
479/*
480 * Called when a lease has completely expired and we've
481 * been unable to renew it.
482 */
483void
484state_init(void)
485{
486 /* Make a DHCPDISCOVER packet, and set appropriate per-interface
487 flags. */
488 make_discover(client->active);
489 client->xid = client->packet.xid;
490 client->destination = iaddr_broadcast;
491 client->state = S_SELECTING;
492 client->first_sending = cur_time;
493 client->interval = config->initial_interval;
494
495 /* Add an immediate timeout to cause the first DHCPDISCOVER packet
496 to go out. */
497 send_discover();
498}
499
500/*
501 * state_selecting is called when one or more DHCPOFFER packets
502 * have been received and a configurable period of time has passed.
503 */
504void
505state_selecting(void)
506{
507 struct client_lease *lp, *next, *picked;
508
509 /* Cancel state_selecting and send_discover timeouts, since either
510 one could have got us here. */
511 cancel_timeout(state_selecting);
512 cancel_timeout(send_discover);
513
514 /* We have received one or more DHCPOFFER packets. Currently,
515 the only criterion by which we judge leases is whether or
516 not we get a response when we arp for them. */
517 picked = NULL;
518 for (lp = client->offered_leases; lp; lp = next) {
519 next = lp->next;
520
521 /* Check to see if we got an ARPREPLY for the address
522 in this particular lease. */
523 if (!picked) {
524 script_init("ARPCHECK", lp->medium);
525 script_write_params("check_", lp);
526
527 /* If the ARPCHECK code detects another
528 machine using the offered address, it exits
529 nonzero. We need to send a DHCPDECLINE and
530 toss the lease. */
531 if (script_go()) {
532 make_decline(lp);
533 send_decline();
534 goto freeit;
535 }
536 picked = lp;
537 picked->next = NULL;
538 } else {
539freeit:
540 free_client_lease(lp);
541 }
542 }
543 client->offered_leases = NULL;
544
545 /* If we just tossed all the leases we were offered, go back
546 to square one. */
547 if (!picked) {
548 client->state = S_INIT;
549 state_init();
550 return;
551 }
552
553 /* If it was a BOOTREPLY, we can just take the address right now. */
554 if (!picked->options[DHO_DHCP_MESSAGE_TYPE].len) {
555 client->new = picked;
556
557 /* Make up some lease expiry times
558 XXX these should be configurable. */
559 client->new->expiry = cur_time + 12000;
560 client->new->renewal += cur_time + 8000;
561 client->new->rebind += cur_time + 10000;
562
563 client->state = S_REQUESTING;
564
565 /* Bind to the address we received. */
566 bind_lease();
567 return;
568 }
569
570 /* Go to the REQUESTING state. */
571 client->destination = iaddr_broadcast;
572 client->state = S_REQUESTING;
573 client->first_sending = cur_time;
574 client->interval = config->initial_interval;
575
576 /* Make a DHCPREQUEST packet from the lease we picked. */
577 make_request(picked);
578 client->xid = client->packet.xid;
579
580 /* Toss the lease we picked - we'll get it back in a DHCPACK. */
581 free_client_lease(picked);
582
583 /* Add an immediate timeout to send the first DHCPREQUEST packet. */
584 send_request();
585}
586
587void
588dhcpack(struct iaddr client_addr, struct option_data *options)
589{
590 struct client_lease *lease;
591
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592
593 if (client->state != S_REBOOTING &&
594 client->state != S_REQUESTING &&
595 client->state != S_RENEWING &&
596 client->state != S_REBINDING)
597 return;
598
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599
600 lease = packet_to_lease(options);
601 if (!lease) {
602 note("packet_to_lease failed.");
603 return;
604 }
605
606 client->new = lease;
607
608 /* Stop resending DHCPREQUEST. */
609 cancel_timeout(send_request);
610
611 /* Figure out the lease time. */
612 if (client->new->options[DHO_DHCP_LEASE_TIME].data)
613 client->new->expiry =
614 getULong(client->new->options[DHO_DHCP_LEASE_TIME].data);
615 else
616 client->new->expiry = DEFAULT_LEASE_TIME;
617 /* A number that looks negative here is really just very large,
618 because the lease expiry offset is unsigned. */
619 if (client->new->expiry < 0)
620 client->new->expiry = TIME_MAX;
621 /* XXX should be fixed by resetting the client state */
622 if (client->new->expiry < 60)
623 client->new->expiry = 60;
624
625 /* Take the server-provided renewal time if there is one;
626 otherwise figure it out according to the spec. */
627 if (client->new->options[DHO_DHCP_RENEWAL_TIME].len)
628 client->new->renewal =
629 getULong(client->new->options[DHO_DHCP_RENEWAL_TIME].data);
630 else
631 client->new->renewal = client->new->expiry / 2;
632
633 /* Same deal with the rebind time. */
634 if (client->new->options[DHO_DHCP_REBINDING_TIME].len)
635 client->new->rebind =
636 getULong(client->new->options[DHO_DHCP_REBINDING_TIME].data);
637 else
638 client->new->rebind = client->new->renewal +
639 client->new->renewal / 2 + client->new->renewal / 4;
640
641 client->new->expiry += cur_time;
642 /* Lease lengths can never be negative. */
643 if (client->new->expiry < cur_time)
644 client->new->expiry = TIME_MAX;
645 client->new->renewal += cur_time;
646 if (client->new->renewal < cur_time)
647 client->new->renewal = TIME_MAX;
648 client->new->rebind += cur_time;
649 if (client->new->rebind < cur_time)
650 client->new->rebind = TIME_MAX;
651
652 bind_lease();
653}
654
655void
656bind_lease(void)
657{
658 /* Remember the medium. */
659 client->new->medium = client->medium;
660
661 /* Write out the new lease. */
662 write_client_lease(client->new, 0);
663
664 /* Run the client script with the new parameters. */
665 script_init((client->state == S_REQUESTING ? "BOUND" :
666 (client->state == S_RENEWING ? "RENEW" :
667 (client->state == S_REBOOTING ? "REBOOT" : "REBIND"))),
668 client->new->medium);
669 if (client->active && client->state != S_REBOOTING)
670 script_write_params("old_", client->active);
671 script_write_params("new_", client->new);
672 if (client->alias)
673 script_write_params("alias_", client->alias);
674 script_go();
675
676 /* Replace the old active lease with the new one. */
677 if (client->active)
678 free_client_lease(client->active);
679 client->active = client->new;
680 client->new = NULL;
681
682 /* Set up a timeout to start the renewal process. */
683 add_timeout(client->active->renewal, state_bound);
684
685 note("bound to %s -- renewal in %ld seconds.",
686 piaddr(client->active->address),
687 client->active->renewal - cur_time);
688 client->state = S_BOUND;
689 reinitialize_interface();
690 go_daemon();
691}
692
693/*
694 * state_bound is called when we've successfully bound to a particular
695 * lease, but the renewal time on that lease has expired. We are
696 * expected to unicast a DHCPREQUEST to the server that gave us our
697 * original lease.
698 */
699void
700state_bound(void)
701{
702 /* T1 has expired. */
703 make_request(client->active);
704 client->xid = client->packet.xid;
705
706 if (client->active->options[DHO_DHCP_SERVER_IDENTIFIER].len == 4) {
707 memcpy(client->destination.iabuf,
708 client->active->options[DHO_DHCP_SERVER_IDENTIFIER].data,
709 4);
710 client->destination.len = 4;
711 } else
712 client->destination = iaddr_broadcast;
713
714 client->first_sending = cur_time;
715 client->interval = config->initial_interval;
716 client->state = S_RENEWING;
717
718 /* Send the first packet immediately. */
719 send_request();
720}
721
722void
723dhcpoffer(struct iaddr client_addr, struct option_data *options)
724{
725 struct client_lease *lease, *lp;
726 int i;
727 int arp_timeout_needed, stop_selecting;
728 char *name = options[DHO_DHCP_MESSAGE_TYPE].len ? "DHCPOFFER" :
729 "BOOTREPLY";
730
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731
732 if (client->state != S_SELECTING)
733 return;
734
846204b6
HT
735
736 /* If this lease doesn't supply the minimum required parameters,
737 blow it off. */
738 for (i = 0; config->required_options[i]; i++) {
739 if (!options[config->required_options[i]].len) {
740 note("%s isn't satisfactory.", name);
741 return;
742 }
743 }
744
745 /* If we've already seen this lease, don't record it again. */
746 for (lease = client->offered_leases;
747 lease; lease = lease->next) {
748 if (lease->address.len == sizeof(client->packet.yiaddr) &&
749 !memcmp(lease->address.iabuf,
750 &client->packet.yiaddr, lease->address.len)) {
751 debug("%s already seen.", name);
752 return;
753 }
754 }
755
756 lease = packet_to_lease(options);
757 if (!lease) {
758 note("packet_to_lease failed.");
759 return;
760 }
761
762 /* If this lease was acquired through a BOOTREPLY, record that
763 fact. */
764 if (!options[DHO_DHCP_MESSAGE_TYPE].len)
765 lease->is_bootp = 1;
766
767 /* Record the medium under which this lease was offered. */
768 lease->medium = client->medium;
769
770 /* Send out an ARP Request for the offered IP address. */
771 script_init("ARPSEND", lease->medium);
772 script_write_params("check_", lease);
773 /* If the script can't send an ARP request without waiting,
774 we'll be waiting when we do the ARPCHECK, so don't wait now. */
775 if (script_go())
776 arp_timeout_needed = 0;
777 else
778 arp_timeout_needed = 2;
779
780 /* Figure out when we're supposed to stop selecting. */
781 stop_selecting = client->first_sending + config->select_interval;
782
783 /* If this is the lease we asked for, put it at the head of the
784 list, and don't mess with the arp request timeout. */
785 if (lease->address.len == client->requested_address.len &&
786 !memcmp(lease->address.iabuf,
787 client->requested_address.iabuf,
788 client->requested_address.len)) {
789 lease->next = client->offered_leases;
790 client->offered_leases = lease;
791 } else {
792 /* If we already have an offer, and arping for this
793 offer would take us past the selection timeout,
794 then don't extend the timeout - just hope for the
795 best. */
796 if (client->offered_leases &&
797 (cur_time + arp_timeout_needed) > stop_selecting)
798 arp_timeout_needed = 0;
799
800 /* Put the lease at the end of the list. */
801 lease->next = NULL;
802 if (!client->offered_leases)
803 client->offered_leases = lease;
804 else {
805 for (lp = client->offered_leases; lp->next;
806 lp = lp->next)
807 ; /* nothing */
808 lp->next = lease;
809 }
810 }
811
812 /* If we're supposed to stop selecting before we've had time
813 to wait for the ARPREPLY, add some delay to wait for
814 the ARPREPLY. */
815 if (stop_selecting - cur_time < arp_timeout_needed)
816 stop_selecting = cur_time + arp_timeout_needed;
817
818 /* If the selecting interval has expired, go immediately to
819 state_selecting(). Otherwise, time out into
820 state_selecting at the select interval. */
821 if (stop_selecting <= 0)
822 state_selecting();
823 else {
824 add_timeout(stop_selecting, state_selecting);
825 cancel_timeout(send_discover);
826 }
827}
828
829/*
830 * Allocate a client_lease structure and initialize it from the
831 * parameters in the specified packet.
832 */
833struct client_lease *
834packet_to_lease(struct option_data *options)
835{
836 struct client_lease *lease;
837 int i;
838
839 lease = malloc(sizeof(struct client_lease));
840
841 if (!lease) {
842 warning("dhcpoffer: no memory to record lease.");
843 return (NULL);
844 }
845
846 memset(lease, 0, sizeof(*lease));
847
848 /* Copy the lease options. */
849 for (i = 0; i < 256; i++) {
850 if (options[i].len) {
851 lease->options[i] = options[i];
852 options[i].data = NULL;
853 options[i].len = 0;
854 if (!check_option(lease, i)) {
855 warning("Invalid lease option - ignoring offer");
856 free_client_lease(lease);
857 return (NULL);
858 }
859 }
860 }
861
862 lease->address.len = sizeof(client->packet.yiaddr);
863 memcpy(lease->address.iabuf, &client->packet.yiaddr,
864 lease->address.len);
865
866 /* If the server name was filled out, copy it. */
867 if ((!lease->options[DHO_DHCP_OPTION_OVERLOAD].len ||
868 !(lease->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 2)) &&
869 client->packet.sname[0]) {
870 lease->server_name = malloc(DHCP_SNAME_LEN + 1);
871 if (!lease->server_name) {
872 warning("dhcpoffer: no memory for server name.");
873 free_client_lease(lease);
874 return (NULL);
875 }
876 memcpy(lease->server_name, client->packet.sname,
877 DHCP_SNAME_LEN);
878 lease->server_name[DHCP_SNAME_LEN] = '\0';
879 if (!res_hnok(lease->server_name)) {
880 warning("Bogus server name %s", lease->server_name);
881 free(lease->server_name);
882 lease->server_name = NULL;
883 }
884 }
885
886 /* Ditto for the filename. */
887 if ((!lease->options[DHO_DHCP_OPTION_OVERLOAD].len ||
888 !(lease->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 1)) &&
889 client->packet.file[0]) {
890 /* Don't count on the NUL terminator. */
891 lease->filename = malloc(DHCP_FILE_LEN + 1);
892 if (!lease->filename) {
893 warning("dhcpoffer: no memory for filename.");
894 free_client_lease(lease);
895 return (NULL);
896 }
897 memcpy(lease->filename, client->packet.file, DHCP_FILE_LEN);
898 lease->filename[DHCP_FILE_LEN] = '\0';
899 }
900 return lease;
901}
902
903void
904dhcpnak(struct iaddr client_addr, struct option_data *options)
905{
846204b6
HT
906
907 if (client->state != S_REBOOTING &&
908 client->state != S_REQUESTING &&
909 client->state != S_RENEWING &&
910 client->state != S_REBINDING)
911 return;
912
846204b6
HT
913
914 if (!client->active) {
915 note("DHCPNAK with no active lease.");
916 return;
917 }
918
919 free_client_lease(client->active);
920 client->active = NULL;
921
922 /* Stop sending DHCPREQUEST packets... */
923 cancel_timeout(send_request);
924
925 client->state = S_INIT;
926 state_init();
927}
928
929/*
930 * Send out a DHCPDISCOVER packet, and set a timeout to send out another
931 * one after the right interval has expired. If we don't get an offer by
932 * the time we reach the panic interval, call the panic function.
933 */
934void
935send_discover(void)
936{
937 int interval, increase = 1;
938
939 /* Figure out how long it's been since we started transmitting. */
940 interval = cur_time - client->first_sending;
941
942 /* If we're past the panic timeout, call the script and tell it
943 we haven't found anything for this interface yet. */
944 if (interval > config->timeout) {
945 state_panic();
946 return;
947 }
948
949 /* If we're selecting media, try the whole list before doing
950 the exponential backoff, but if we've already received an
951 offer, stop looping, because we obviously have it right. */
952 if (!client->offered_leases && config->media) {
953 int fail = 0;
954again:
955 if (client->medium) {
956 client->medium = client->medium->next;
957 increase = 0;
958 }
959 if (!client->medium) {
960 if (fail)
961 error("No valid media types for %s!", ifi->name);
962 client->medium = config->media;
963 increase = 1;
964 }
965
966 note("Trying medium \"%s\" %d", client->medium->string,
967 increase);
968 script_init("MEDIUM", client->medium);
969 if (script_go())
970 goto again;
971 }
972
973 /*
974 * If we're supposed to increase the interval, do so. If it's
975 * currently zero (i.e., we haven't sent any packets yet), set
976 * it to initial_interval; otherwise, add to it a random
977 * number between zero and two times itself. On average, this
978 * means that it will double with every transmission.
979 */
980 if (increase) {
981 if (!client->interval)
982 client->interval = config->initial_interval;
983 else {
984 client->interval += (arc4random() >> 2) %
985 (2 * client->interval);
986 }
987
988 /* Don't backoff past cutoff. */
989 if (client->interval > config->backoff_cutoff)
990 client->interval = ((config->backoff_cutoff / 2)
991 + ((arc4random() >> 2) %
992 config->backoff_cutoff));
993 } else if (!client->interval)
994 client->interval = config->initial_interval;
995
996 /* If the backoff would take us to the panic timeout, just use that
997 as the interval. */
998 if (cur_time + client->interval >
999 client->first_sending + config->timeout)
1000 client->interval = (client->first_sending +
1001 config->timeout) - cur_time + 1;
1002
1003 /* Record the number of seconds since we started sending. */
1004 if (interval < 65536)
1005 client->packet.secs = htons(interval);
1006 else
1007 client->packet.secs = htons(65535);
1008 client->secs = client->packet.secs;
1009
1010 note("DHCPDISCOVER on %s to %s port %d interval %ld",
1011 ifi->name, inet_ntoa(sockaddr_broadcast.sin_addr),
1012 ntohs(sockaddr_broadcast.sin_port), client->interval);
1013
1014 /* Send out a packet. */
1015 send_packet(inaddr_any, &sockaddr_broadcast, NULL);
1016
1017 add_timeout(cur_time + client->interval, send_discover);
1018}
1019
1020/*
1021 * state_panic gets called if we haven't received any offers in a preset
1022 * amount of time. When this happens, we try to use existing leases
1023 * that haven't yet expired, and failing that, we call the client script
1024 * and hope it can do something.
1025 */
1026void
1027state_panic(void)
1028{
1029 struct client_lease *loop = client->active;
1030 struct client_lease *lp;
1031
1032 note("No DHCPOFFERS received.");
1033
1034 /* We may not have an active lease, but we may have some
1035 predefined leases that we can try. */
1036 if (!client->active && client->leases)
1037 goto activate_next;
1038
1039 /* Run through the list of leases and see if one can be used. */
1040 while (client->active) {
1041 if (client->active->expiry > cur_time) {
1042 note("Trying recorded lease %s",
1043 piaddr(client->active->address));
1044 /* Run the client script with the existing
1045 parameters. */
1046 script_init("TIMEOUT",
1047 client->active->medium);
1048 script_write_params("new_", client->active);
1049 if (client->alias)
1050 script_write_params("alias_",
1051 client->alias);
1052
1053 /* If the old lease is still good and doesn't
1054 yet need renewal, go into BOUND state and
1055 timeout at the renewal time. */
1056 if (!script_go()) {
1057 if (cur_time <
1058 client->active->renewal) {
1059 client->state = S_BOUND;
1060 note("bound: renewal in %ld seconds.",
1061 client->active->renewal -
1062 cur_time);
1063 add_timeout(client->active->renewal,
1064 state_bound);
1065 } else {
1066 client->state = S_BOUND;
1067 note("bound: immediate renewal.");
1068 state_bound();
1069 }
1070 reinitialize_interface();
1071 go_daemon();
1072 return;
1073 }
1074 }
1075
1076 /* If there are no other leases, give up. */
1077 if (!client->leases) {
1078 client->leases = client->active;
1079 client->active = NULL;
1080 break;
1081 }
1082
1083activate_next:
1084 /* Otherwise, put the active lease at the end of the
1085 lease list, and try another lease.. */
1086 for (lp = client->leases; lp->next; lp = lp->next)
1087 ;
1088 lp->next = client->active;
1089 if (lp->next)
1090 lp->next->next = NULL;
1091 client->active = client->leases;
1092 client->leases = client->leases->next;
1093
1094 /* If we already tried this lease, we've exhausted the
1095 set of leases, so we might as well give up for
1096 now. */
1097 if (client->active == loop)
1098 break;
1099 else if (!loop)
1100 loop = client->active;
1101 }
1102
1103 /* No leases were available, or what was available didn't work, so
1104 tell the shell script that we failed to allocate an address,
1105 and try again later. */
1106 note("No working leases in persistent database - sleeping.");
1107 script_init("FAIL", NULL);
1108 if (client->alias)
1109 script_write_params("alias_", client->alias);
1110 script_go();
1111 client->state = S_INIT;
1112 add_timeout(cur_time + config->retry_interval, state_init);
1113 go_daemon();
1114}
1115
1116void
1117send_request(void)
1118{
1119 struct sockaddr_in destination;
1120 struct in_addr from;
1121 int interval;
1122
1123 /* Figure out how long it's been since we started transmitting. */
1124 interval = cur_time - client->first_sending;
1125
1126 /* If we're in the INIT-REBOOT or REQUESTING state and we're
1127 past the reboot timeout, go to INIT and see if we can
1128 DISCOVER an address... */
1129 /* XXX In the INIT-REBOOT state, if we don't get an ACK, it
1130 means either that we're on a network with no DHCP server,
1131 or that our server is down. In the latter case, assuming
1132 that there is a backup DHCP server, DHCPDISCOVER will get
1133 us a new address, but we could also have successfully
1134 reused our old address. In the former case, we're hosed
1135 anyway. This is not a win-prone situation. */
1136 if ((client->state == S_REBOOTING ||
1137 client->state == S_REQUESTING) &&
1138 interval > config->reboot_timeout) {
1139cancel:
1140 client->state = S_INIT;
1141 cancel_timeout(send_request);
1142 state_init();
1143 return;
1144 }
1145
1146 /* If we're in the reboot state, make sure the media is set up
1147 correctly. */
1148 if (client->state == S_REBOOTING &&
1149 !client->medium &&
1150 client->active->medium) {
1151 script_init("MEDIUM", client->active->medium);
1152
1153 /* If the medium we chose won't fly, go to INIT state. */
1154 if (script_go())
1155 goto cancel;
1156
1157 /* Record the medium. */
1158 client->medium = client->active->medium;
1159 }
1160
1161 /* If the lease has expired, relinquish the address and go back
1162 to the INIT state. */
1163 if (client->state != S_REQUESTING &&
1164 cur_time > client->active->expiry) {
1165 /* Run the client script with the new parameters. */
1166 script_init("EXPIRE", NULL);
1167 script_write_params("old_", client->active);
1168 if (client->alias)
1169 script_write_params("alias_", client->alias);
1170 script_go();
1171
1172 /* Now do a preinit on the interface so that we can
1173 discover a new address. */
1174 script_init("PREINIT", NULL);
1175 if (client->alias)
1176 script_write_params("alias_", client->alias);
1177 script_go();
1178
1179 client->state = S_INIT;
1180 state_init();
1181 return;
1182 }
1183
1184 /* Do the exponential backoff... */
1185 if (!client->interval)
1186 client->interval = config->initial_interval;
1187 else
1188 client->interval += ((arc4random() >> 2) %
1189 (2 * client->interval));
1190
1191 /* Don't backoff past cutoff. */
1192 if (client->interval > config->backoff_cutoff)
1193 client->interval = ((config->backoff_cutoff / 2) +
1194 ((arc4random() >> 2) % client->interval));
1195
1196 /* If the backoff would take us to the expiry time, just set the
1197 timeout to the expiry time. */
1198 if (client->state != S_REQUESTING && cur_time + client->interval >
1199 client->active->expiry)
1200 client->interval = client->active->expiry - cur_time + 1;
1201
1202 /* If the lease T2 time has elapsed, or if we're not yet bound,
1203 broadcast the DHCPREQUEST rather than unicasting. */
1204 memset(&destination, 0, sizeof(destination));
1205 if (client->state == S_REQUESTING ||
1206 client->state == S_REBOOTING ||
1207 cur_time > client->active->rebind)
1208 destination.sin_addr.s_addr = INADDR_BROADCAST;
1209 else
1210 memcpy(&destination.sin_addr.s_addr, client->destination.iabuf,
1211 sizeof(destination.sin_addr.s_addr));
1212 destination.sin_port = htons(REMOTE_PORT);
1213 destination.sin_family = AF_INET;
1214 destination.sin_len = sizeof(destination);
1215
1216 if (client->state != S_REQUESTING)
1217 memcpy(&from, client->active->address.iabuf, sizeof(from));
1218 else
1219 from.s_addr = INADDR_ANY;
1220
1221 /* Record the number of seconds since we started sending. */
1222 if (client->state == S_REQUESTING)
1223 client->packet.secs = client->secs;
1224 else {
1225 if (interval < 65536)
1226 client->packet.secs = htons(interval);
1227 else
1228 client->packet.secs = htons(65535);
1229 }
1230
1231 note("DHCPREQUEST on %s to %s port %d", ifi->name,
1232 inet_ntoa(destination.sin_addr), ntohs(destination.sin_port));
1233
1234 /* Send out a packet. */
1235 send_packet(from, &destination, NULL);
1236
1237 add_timeout(cur_time + client->interval, send_request);
1238}
1239
1240void
1241send_decline(void)
1242{
1243 note("DHCPDECLINE on %s to %s port %d", ifi->name,
1244 inet_ntoa(sockaddr_broadcast.sin_addr),
1245 ntohs(sockaddr_broadcast.sin_port));
1246
1247 /* Send out a packet. */
1248 send_packet(inaddr_any, &sockaddr_broadcast, NULL);
1249}
1250
1251void
1252make_discover(struct client_lease *lease)
1253{
1254 unsigned char discover = DHCPDISCOVER;
1255 struct option_data options[256];
1256 int i;
1257
1258 memset(options, 0, sizeof(options));
1259 memset(&client->packet, 0, sizeof(client->packet));
1260
1261 /* Set DHCP_MESSAGE_TYPE to DHCPDISCOVER */
1262 i = DHO_DHCP_MESSAGE_TYPE;
1263 options[i].data = &discover;
1264 options[i].len = sizeof(discover);
1265
1266 /* Request the options we want */
1267 i = DHO_DHCP_PARAMETER_REQUEST_LIST;
1268 options[i].data = config->requested_options;
1269 options[i].len = config->requested_option_count;
1270
1271 /* If we had an address, try to get it again. */
1272 if (lease) {
1273 client->requested_address = lease->address;
1274 i = DHO_DHCP_REQUESTED_ADDRESS;
1275 options[i].data = lease->address.iabuf;
1276 options[i].len = lease->address.len;
1277 } else
1278 client->requested_address.len = 0;
1279
1280 /* Send any options requested in the config file. */
1281 for (i = 0; i < 256; i++)
1282 if (!options[i].data &&
1283 config->send_options[i].data) {
1284 options[i].data = config->send_options[i].data;
1285 options[i].len = config->send_options[i].len;
1286 }
1287
1288 /* Set up the option buffer to fit in a minimal UDP packet. */
1289 i = cons_options(client->packet.options, 576 - DHCP_FIXED_LEN,
1290 options);
1291 if (i == -1 || client->packet.options[i] != DHO_END)
1292 error("options do not fit in DHCPDISCOVER packet.");
1293 client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1294 if (client->packet_length < BOOTP_MIN_LEN)
1295 client->packet_length = BOOTP_MIN_LEN;
1296
1297 client->packet.op = BOOTREQUEST;
1298 client->packet.htype = ifi->hw_address.htype;
1299 client->packet.hlen = ifi->hw_address.hlen;
1300 client->packet.hops = 0;
1301 client->packet.xid = arc4random();
1302 client->packet.secs = 0; /* filled in by send_discover. */
1303 client->packet.flags = 0;
1304
1305 memset(&client->packet.ciaddr, 0, sizeof(client->packet.ciaddr));
1306 memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1307 memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1308 memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1309 memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1310 ifi->hw_address.hlen);
1311}
1312
1313void
1314make_request(struct client_lease * lease)
1315{
1316 unsigned char request = DHCPREQUEST;
1317 struct option_data options[256];
1318 int i;
1319
1320 memset(options, 0, sizeof(options));
1321 memset(&client->packet, 0, sizeof(client->packet));
1322
1323 /* Set DHCP_MESSAGE_TYPE to DHCPREQUEST */
1324 i = DHO_DHCP_MESSAGE_TYPE;
1325 options[i].data = &request;
1326 options[i].len = sizeof(request);
1327
1328 /* Request the options we want */
1329 i = DHO_DHCP_PARAMETER_REQUEST_LIST;
1330 options[i].data = config->requested_options;
1331 options[i].len = config->requested_option_count;
1332
1333 /* If we are requesting an address that hasn't yet been assigned
1334 to us, use the DHCP Requested Address option. */
1335 if (client->state == S_REQUESTING) {
1336 /* Send back the server identifier... */
1337 i = DHO_DHCP_SERVER_IDENTIFIER;
1338 options[i].data = lease->options[i].data;
1339 options[i].len = lease->options[i].len;
1340 }
1341 if (client->state == S_REQUESTING ||
1342 client->state == S_REBOOTING) {
1343 client->requested_address = lease->address;
1344 i = DHO_DHCP_REQUESTED_ADDRESS;
1345 options[i].data = lease->address.iabuf;
1346 options[i].len = lease->address.len;
1347 } else
1348 client->requested_address.len = 0;
1349
1350 /* Send any options requested in the config file. */
1351 for (i = 0; i < 256; i++)
1352 if (!options[i].data && config->send_options[i].data) {
1353 options[i].data = config->send_options[i].data;
1354 options[i].len = config->send_options[i].len;
1355 }
1356
1357 /* Set up the option buffer to fit in a minimal UDP packet. */
1358 i = cons_options(client->packet.options, 576 - DHCP_FIXED_LEN,
1359 options);
1360 if (i == -1 || client->packet.options[i] != DHO_END)
1361 error("options do not fit in DHCPREQUEST packet.");
1362 client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1363 if (client->packet_length < BOOTP_MIN_LEN)
1364 client->packet_length = BOOTP_MIN_LEN;
1365
1366 client->packet.op = BOOTREQUEST;
1367 client->packet.htype = ifi->hw_address.htype;
1368 client->packet.hlen = ifi->hw_address.hlen;
1369 client->packet.hops = 0;
1370 client->packet.xid = client->xid;
1371 client->packet.secs = 0; /* Filled in by send_request. */
1372 client->packet.flags = 0;
1373
1374 /* If we own the address we're requesting, put it in ciaddr;
1375 otherwise set ciaddr to zero. */
1376 if (client->state == S_BOUND ||
1377 client->state == S_RENEWING ||
1378 client->state == S_REBINDING) {
1379 memcpy(&client->packet.ciaddr,
1380 lease->address.iabuf, lease->address.len);
1381 } else {
1382 memset(&client->packet.ciaddr, 0,
1383 sizeof(client->packet.ciaddr));
1384 }
1385
1386 memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1387 memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1388 memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1389 memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1390 ifi->hw_address.hlen);
1391}
1392
1393void
1394make_decline(struct client_lease *lease)
1395{
1396 struct option_data options[256];
1397 unsigned char decline = DHCPDECLINE;
1398 int i;
1399
1400 memset(options, 0, sizeof(options));
1401 memset(&client->packet, 0, sizeof(client->packet));
1402
1403 /* Set DHCP_MESSAGE_TYPE to DHCPDECLINE */
1404 i = DHO_DHCP_MESSAGE_TYPE;
1405 options[i].data = &decline;
1406 options[i].len = sizeof(decline);
1407
1408 /* Send back the server identifier... */
1409 i = DHO_DHCP_SERVER_IDENTIFIER;
1410 options[i].data = lease->options[i].data;
1411 options[i].len = lease->options[i].len;
1412
1413 /* Send back the address we're declining. */
1414 i = DHO_DHCP_REQUESTED_ADDRESS;
1415 options[i].data = lease->address.iabuf;
1416 options[i].len = lease->address.len;
1417
1418 /* Send the uid if the user supplied one. */
1419 i = DHO_DHCP_CLIENT_IDENTIFIER;
1420 if (config->send_options[i].len) {
1421 options[i].data = config->send_options[i].data;
1422 options[i].len = config->send_options[i].len;
1423 }
1424
1425 /* Set up the option buffer to fit in a minimal UDP packet. */
1426 i = cons_options(client->packet.options, 576 - DHCP_FIXED_LEN,
1427 options);
1428 if (i == -1 || client->packet.options[i] != DHO_END)
1429 error("options do not fit in DHCPDECLINE packet.");
1430 client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1431 if (client->packet_length < BOOTP_MIN_LEN)
1432 client->packet_length = BOOTP_MIN_LEN;
1433
1434 client->packet.op = BOOTREQUEST;
1435 client->packet.htype = ifi->hw_address.htype;
1436 client->packet.hlen = ifi->hw_address.hlen;
1437 client->packet.hops = 0;
1438 client->packet.xid = client->xid;
1439 client->packet.secs = 0; /* Filled in by send_request. */
1440 client->packet.flags = 0;
1441
1442 /* ciaddr must always be zero. */
1443 memset(&client->packet.ciaddr, 0, sizeof(client->packet.ciaddr));
1444 memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1445 memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1446 memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1447 memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1448 ifi->hw_address.hlen);
1449}
1450
1451void
1452free_client_lease(struct client_lease *lease)
1453{
1454 int i;
1455
1456 if (lease->server_name)
1457 free(lease->server_name);
1458 if (lease->filename)
1459 free(lease->filename);
1460 for (i = 0; i < 256; i++) {
1461 if (lease->options[i].len)
1462 free(lease->options[i].data);
1463 }
1464 free(lease);
1465}
1466
1467void
1468rewrite_client_leases(void)
1469{
1470 struct client_lease *lp;
1471
1472 if (!leaseFile) /* XXX */
1473 error("lease file not open");
1474
1475 fflush(leaseFile);
1476 rewind(leaseFile);
1477
1478 for (lp = client->leases; lp; lp = lp->next)
1479 write_client_lease(lp, 1);
1480 if (client->active)
1481 write_client_lease(client->active, 1);
1482
1483 fflush(leaseFile);
1484 ftruncate(fileno(leaseFile), ftello(leaseFile));
1485 fsync(fileno(leaseFile));
1486}
1487
1488void
1489write_client_lease(struct client_lease *lease, int rewrite)
1490{
1491 static int leases_written;
1492 struct tm *t;
1493 int i;
1494
1495 if (!rewrite) {
1496 if (leases_written++ > 20) {
1497 rewrite_client_leases();
1498 leases_written = 0;
1499 }
1500 }
1501
1502 /* If the lease came from the config file, we don't need to stash
1503 a copy in the lease database. */
1504 if (lease->is_static)
1505 return;
1506
1507 if (!leaseFile) /* XXX */
1508 error("lease file not open");
1509
1510 fprintf(leaseFile, "lease {\n");
1511 if (lease->is_bootp)
1512 fprintf(leaseFile, " bootp;\n");
1513 fprintf(leaseFile, " interface \"%s\";\n", ifi->name);
1514 fprintf(leaseFile, " fixed-address %s;\n", piaddr(lease->address));
1515 if (lease->filename)
1516 fprintf(leaseFile, " filename \"%s\";\n", lease->filename);
1517 if (lease->server_name)
1518 fprintf(leaseFile, " server-name \"%s\";\n",
1519 lease->server_name);
1520 if (lease->medium)
1521 fprintf(leaseFile, " medium \"%s\";\n", lease->medium->string);
1522 for (i = 0; i < 256; i++)
1523 if (lease->options[i].len)
1524 fprintf(leaseFile, " option %s %s;\n",
1525 dhcp_options[i].name,
1526 pretty_print_option(i, lease->options[i].data,
1527 lease->options[i].len, 1, 1));
1528
1529 t = gmtime(&lease->renewal);
1530 fprintf(leaseFile, " renew %d %d/%d/%d %02d:%02d:%02d;\n",
1531 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1532 t->tm_hour, t->tm_min, t->tm_sec);
1533 t = gmtime(&lease->rebind);
1534 fprintf(leaseFile, " rebind %d %d/%d/%d %02d:%02d:%02d;\n",
1535 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1536 t->tm_hour, t->tm_min, t->tm_sec);
1537 t = gmtime(&lease->expiry);
1538 fprintf(leaseFile, " expire %d %d/%d/%d %02d:%02d:%02d;\n",
1539 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1540 t->tm_hour, t->tm_min, t->tm_sec);
1541 fprintf(leaseFile, "}\n");
1542 fflush(leaseFile);
1543}
1544
1545void
1546script_init(char *reason, struct string_list *medium)
1547{
1548 size_t len, mediumlen = 0;
1549 struct imsg_hdr hdr;
1550 struct buf *buf;
1551
1552 if (medium != NULL && medium->string != NULL)
1553 mediumlen = strlen(medium->string);
1554
1555 hdr.code = IMSG_SCRIPT_INIT;
1556 hdr.len = sizeof(struct imsg_hdr) +
1557 sizeof(size_t) + mediumlen +
1558 sizeof(size_t) + strlen(reason);
1559
1560 buf = buf_open(hdr.len);
1561
1562 buf_add(buf, &hdr, sizeof(hdr));
1563 buf_add(buf, &mediumlen, sizeof(mediumlen));
1564 if (mediumlen > 0)
1565 buf_add(buf, medium->string, mediumlen);
1566 len = strlen(reason);
1567 buf_add(buf, &len, sizeof(len));
1568 buf_add(buf, reason, len);
1569
1570 buf_close(privfd, buf);
1571}
1572
1573void
1574priv_script_init(char *reason, char *medium)
1575{
1576 client->scriptEnvsize = 100;
1577 if (client->scriptEnv == NULL)
1578 client->scriptEnv =
1579 calloc(client->scriptEnvsize, sizeof(char *));
1580 if (client->scriptEnv == NULL)
1581 error("script_init: no memory for environment");
1582
1583 client->scriptEnv[0] = strdup(CLIENT_PATH);
1584 if (client->scriptEnv[0] == NULL)
1585 error("script_init: no memory for environment");
1586
1587 client->scriptEnv[1] = NULL;
1588
1589 script_set_env("", "interface", ifi->name);
1590
1591 if (medium)
1592 script_set_env("", "medium", medium);
1593
1594 script_set_env("", "reason", reason);
1595}
1596
1597void
1598priv_script_write_params(char *prefix, struct client_lease *lease)
1599{
1600 u_int8_t dbuf[1500];
1601 int i, len = 0;
1602 char tbuf[128];
1603
1604 script_set_env(prefix, "ip_address", piaddr(lease->address));
1605
1606 if (lease->options[DHO_SUBNET_MASK].len &&
1607 (lease->options[DHO_SUBNET_MASK].len <
1608 sizeof(lease->address.iabuf))) {
1609 struct iaddr netmask, subnet, broadcast;
1610
1611 memcpy(netmask.iabuf, lease->options[DHO_SUBNET_MASK].data,
1612 lease->options[DHO_SUBNET_MASK].len);
1613 netmask.len = lease->options[DHO_SUBNET_MASK].len;
1614
1615 subnet = subnet_number(lease->address, netmask);
1616 if (subnet.len) {
1617 script_set_env(prefix, "network_number",
1618 piaddr(subnet));
1619 if (!lease->options[DHO_BROADCAST_ADDRESS].len) {
1620 broadcast = broadcast_addr(subnet, netmask);
1621 if (broadcast.len)
1622 script_set_env(prefix,
1623 "broadcast_address",
1624 piaddr(broadcast));
1625 }
1626 }
1627 }
1628
1629 if (lease->filename)
1630 script_set_env(prefix, "filename", lease->filename);
1631 if (lease->server_name)
1632 script_set_env(prefix, "server_name",
1633 lease->server_name);
1634 for (i = 0; i < 256; i++) {
1635 u_int8_t *dp = NULL;
1636
1637 if (config->defaults[i].len) {
1638 if (lease->options[i].len) {
1639 switch (config->default_actions[i]) {
1640 case ACTION_DEFAULT:
1641 dp = lease->options[i].data;
1642 len = lease->options[i].len;
1643 break;
1644 case ACTION_SUPERSEDE:
1645supersede:
1646 dp = config->defaults[i].data;
1647 len = config->defaults[i].len;
1648 break;
1649 case ACTION_PREPEND:
1650 len = config->defaults[i].len +
1651 lease->options[i].len;
1652 if (len > sizeof(dbuf)) {
1653 warning("no space to %s %s",
1654 "prepend option",
1655 dhcp_options[i].name);
1656 goto supersede;
1657 }
1658 dp = dbuf;
1659 memcpy(dp,
1660 config->defaults[i].data,
1661 config->defaults[i].len);
1662 memcpy(dp +
1663 config->defaults[i].len,
1664 lease->options[i].data,
1665 lease->options[i].len);
1666 dp[len] = '\0';
1667 break;
1668 case ACTION_APPEND:
1669 len = config->defaults[i].len +
1670 lease->options[i].len;
1671 if (len > sizeof(dbuf)) {
1672 warning("no space to %s %s",
1673 "append option",
1674 dhcp_options[i].name);
1675 goto supersede;
1676 }
1677 dp = dbuf;
1678 memcpy(dp, lease->options[i].data,
1679 lease->options[i].len);
1680 memcpy(dp + lease->options[i].len,
1681 config->defaults[i].data,
1682 config->defaults[i].len);
1683 dp[len] = '\0';
1684 }
1685 } else {
1686 dp = config->defaults[i].data;
1687 len = config->defaults[i].len;
1688 }
1689 } else if (lease->options[i].len) {
1690 len = lease->options[i].len;
1691 dp = lease->options[i].data;
1692 } else {
1693 len = 0;
1694 }
1695 if (len) {
1696 char name[256];
1697
1698 if (dhcp_option_ev_name(name, sizeof(name),
1699 &dhcp_options[i]))
1700 script_set_env(prefix, name,
1701 pretty_print_option(i, dp, len, 0, 0));
1702 }
1703 }
1704 snprintf(tbuf, sizeof(tbuf), "%d", (int)lease->expiry);
1705 script_set_env(prefix, "expiry", tbuf);
1706}
1707
1708void
1709script_write_params(char *prefix, struct client_lease *lease)
1710{
1711 size_t fn_len = 0, sn_len = 0, pr_len = 0;
1712 struct imsg_hdr hdr;
1713 struct buf *buf;
1714 int i;
1715
1716 if (lease->filename != NULL)
1717 fn_len = strlen(lease->filename);
1718 if (lease->server_name != NULL)
1719 sn_len = strlen(lease->server_name);
1720 if (prefix != NULL)
1721 pr_len = strlen(prefix);
1722
1723 hdr.code = IMSG_SCRIPT_WRITE_PARAMS;
1724 hdr.len = sizeof(hdr) + sizeof(struct client_lease) +
1725 sizeof(size_t) + fn_len + sizeof(size_t) + sn_len +
1726 sizeof(size_t) + pr_len;
1727
1728 for (i = 0; i < 256; i++)
1729 hdr.len += sizeof(int) + lease->options[i].len;
1730
1731 scripttime = time(NULL);
1732
1733 buf = buf_open(hdr.len);
1734
1735 buf_add(buf, &hdr, sizeof(hdr));
1736 buf_add(buf, lease, sizeof(struct client_lease));
1737 buf_add(buf, &fn_len, sizeof(fn_len));
1738 buf_add(buf, lease->filename, fn_len);
1739 buf_add(buf, &sn_len, sizeof(sn_len));
1740 buf_add(buf, lease->server_name, sn_len);
1741 buf_add(buf, &pr_len, sizeof(pr_len));
1742 buf_add(buf, prefix, pr_len);
1743
1744 for (i = 0; i < 256; i++) {
1745 buf_add(buf, &lease->options[i].len,
1746 sizeof(lease->options[i].len));
1747 buf_add(buf, lease->options[i].data,
1748 lease->options[i].len);
1749 }
1750
1751 buf_close(privfd, buf);
1752}
1753
1754int
1755script_go(void)
1756{
1757 struct imsg_hdr hdr;
1758 struct buf *buf;
1759 int ret;
1760
1761 scripttime = time(NULL);
1762
1763 hdr.code = IMSG_SCRIPT_GO;
1764 hdr.len = sizeof(struct imsg_hdr);
1765
1766 buf = buf_open(hdr.len);
1767
1768 buf_add(buf, &hdr, sizeof(hdr));
1769 buf_close(privfd, buf);
1770
1771 bzero(&hdr, sizeof(hdr));
1772 buf_read(privfd, &hdr, sizeof(hdr));
1773 if (hdr.code != IMSG_SCRIPT_GO_RET)
1774 error("unexpected msg type %u", hdr.code);
1775 if (hdr.len != sizeof(hdr) + sizeof(int))
1776 error("received corrupted message");
1777 buf_read(privfd, &ret, sizeof(ret));
1778
1779 return (ret);
1780}
1781
1782int
1783priv_script_go(void)
1784{
1785 char *scriptName, *argv[2], **envp;
1786 int pid, wpid, wstatus;
1787
1788 scripttime = time(NULL);
1789
1790 scriptName = config->script_name;
1791 envp = client->scriptEnv;
1792
1793 argv[0] = scriptName;
1794 argv[1] = NULL;
1795
1796 pid = fork();
1797 if (pid < 0) {
1798 error("fork: %m");
1799 wstatus = 0;
1800 } else if (pid) {
1801 do {
1802 wpid = wait(&wstatus);
1803 } while (wpid != pid && wpid > 0);
1804 if (wpid < 0) {
1805 error("wait: %m");
1806 wstatus = 0;
1807 }
1808 } else {
1809 execve(scriptName, argv, envp);
1810 error("execve (%s, ...): %m", scriptName);
1811 }
1812
1813 script_flush_env();
1814
1815 return (WEXITSTATUS(wstatus));
1816}
1817
1818void
1819script_set_env(const char *prefix, const char *name, const char *value)
1820{
1821 int i, j, namelen;
1822
1823 namelen = strlen(name);
1824
1825 for (i = 0; client->scriptEnv[i]; i++)
1826 if (strncmp(client->scriptEnv[i], name, namelen) == 0 &&
1827 client->scriptEnv[i][namelen] == '=')
1828 break;
1829
1830 if (client->scriptEnv[i])
1831 /* Reuse the slot. */
1832 free(client->scriptEnv[i]);
1833 else {
1834 /* New variable. Expand if necessary. */
1835 if (i >= client->scriptEnvsize - 1) {
1836 char **newscriptEnv;
1837 int newscriptEnvsize = client->scriptEnvsize + 50;
1838
1839 newscriptEnv = realloc(client->scriptEnv,
1840 newscriptEnvsize);
1841 if (newscriptEnv == NULL) {
1842 free(client->scriptEnv);
1843 client->scriptEnv = NULL;
1844 client->scriptEnvsize = 0;
1845 error("script_set_env: no memory for variable");
1846 }
1847 client->scriptEnv = newscriptEnv;
1848 client->scriptEnvsize = newscriptEnvsize;
1849 }
1850 /* need to set the NULL pointer at end of array beyond
1851 the new slot. */
1852 client->scriptEnv[i + 1] = NULL;
1853 }
1854 /* Allocate space and format the variable in the appropriate slot. */
1855 client->scriptEnv[i] = malloc(strlen(prefix) + strlen(name) + 1 +
1856 strlen(value) + 1);
1857 if (client->scriptEnv[i] == NULL)
1858 error("script_set_env: no memory for variable assignment");
1859
1860 /* No `` or $() command substitution allowed in environment values! */
1861 for (j = 0; j < strlen(value); j++)
1862 switch (value[j]) {
1863 case '`':
1864 case '$':
1865 error("illegal character (%c) in value '%s'", value[j],
1866 value);
1867 /* not reached */
1868 }
1869 snprintf(client->scriptEnv[i], strlen(prefix) + strlen(name) +
1870 1 + strlen(value) + 1, "%s%s=%s", prefix, name, value);
1871}
1872
1873void
1874script_flush_env(void)
1875{
1876 int i;
1877
1878 for (i = 0; client->scriptEnv[i]; i++) {
1879 free(client->scriptEnv[i]);
1880 client->scriptEnv[i] = NULL;
1881 }
1882 client->scriptEnvsize = 0;
1883}
1884
1885int
1886dhcp_option_ev_name(char *buf, size_t buflen, const struct option *option)
1887{
1888 size_t i;
1889
1890 for (i = 0; option->name[i]; i++) {
1891 if (i + 1 == buflen)
1892 return 0;
1893 if (option->name[i] == '-')
1894 buf[i] = '_';
1895 else
1896 buf[i] = option->name[i];
1897 }
1898
1899 buf[i] = 0;
1900 return 1;
1901}
1902
1903void
1904go_daemon(void)
1905{
1906 static int state = 0;
1907
1908 if (no_daemon || state)
1909 return;
1910
1911 state = 1;
1912
1913 /* Stop logging to stderr... */
1914 log_perror = 0;
1915
1916 if (daemon(1, 0) == -1)
1917 error("daemon");
1918
1919 /* we are chrooted, daemon(3) fails to open /dev/null */
1920 if (nullfd != -1) {
1921 dup2(nullfd, STDIN_FILENO);
1922 dup2(nullfd, STDOUT_FILENO);
1923 dup2(nullfd, STDERR_FILENO);
1924 close(nullfd);
1925 nullfd = -1;
1926 }
1927}
1928
1929int
1930check_option(struct client_lease *l, int option)
1931{
1932 char *opbuf;
1933 char *sbuf;
1934
1935 /* we use this, since this is what gets passed to dhclient-script */
1936
1937 opbuf = pretty_print_option(option, l->options[option].data,
1938 l->options[option].len, 0, 0);
1939
1940 sbuf = option_as_string(option, l->options[option].data,
1941 l->options[option].len);
1942
1943 switch (option) {
1944 case DHO_SUBNET_MASK:
1945 case DHO_TIME_SERVERS:
1946 case DHO_NAME_SERVERS:
1947 case DHO_ROUTERS:
1948 case DHO_DOMAIN_NAME_SERVERS:
1949 case DHO_LOG_SERVERS:
1950 case DHO_COOKIE_SERVERS:
1951 case DHO_LPR_SERVERS:
1952 case DHO_IMPRESS_SERVERS:
1953 case DHO_RESOURCE_LOCATION_SERVERS:
1954 case DHO_SWAP_SERVER:
1955 case DHO_BROADCAST_ADDRESS:
1956 case DHO_NIS_SERVERS:
1957 case DHO_NTP_SERVERS:
1958 case DHO_NETBIOS_NAME_SERVERS:
1959 case DHO_NETBIOS_DD_SERVER:
1960 case DHO_FONT_SERVERS:
1961 case DHO_DHCP_SERVER_IDENTIFIER:
1962 if (!ipv4addrs(opbuf)) {
1963 warning("Invalid IP address in option: %s", opbuf);
1964 return (0);
1965 }
1966 return (1);
1967 case DHO_HOST_NAME:
1968 case DHO_DOMAIN_NAME:
1969 case DHO_NIS_DOMAIN:
1970 if (!res_hnok(sbuf)) {
1971 warning("Bogus Host Name option %d: %s (%s)", option,
1972 sbuf, opbuf);
1973 l->options[option].len = 0;
1974 free(l->options[option].data);
1975 }
1976 return (1);
1977 case DHO_PAD:
1978 case DHO_TIME_OFFSET:
1979 case DHO_BOOT_SIZE:
1980 case DHO_MERIT_DUMP:
1981 case DHO_ROOT_PATH:
1982 case DHO_EXTENSIONS_PATH:
1983 case DHO_IP_FORWARDING:
1984 case DHO_NON_LOCAL_SOURCE_ROUTING:
1985 case DHO_POLICY_FILTER:
1986 case DHO_MAX_DGRAM_REASSEMBLY:
1987 case DHO_DEFAULT_IP_TTL:
1988 case DHO_PATH_MTU_AGING_TIMEOUT:
1989 case DHO_PATH_MTU_PLATEAU_TABLE:
1990 case DHO_INTERFACE_MTU:
1991 case DHO_ALL_SUBNETS_LOCAL:
1992 case DHO_PERFORM_MASK_DISCOVERY:
1993 case DHO_MASK_SUPPLIER:
1994 case DHO_ROUTER_DISCOVERY:
1995 case DHO_ROUTER_SOLICITATION_ADDRESS:
1996 case DHO_STATIC_ROUTES:
1997 case DHO_TRAILER_ENCAPSULATION:
1998 case DHO_ARP_CACHE_TIMEOUT:
1999 case DHO_IEEE802_3_ENCAPSULATION:
2000 case DHO_DEFAULT_TCP_TTL:
2001 case DHO_TCP_KEEPALIVE_INTERVAL:
2002 case DHO_TCP_KEEPALIVE_GARBAGE:
2003 case DHO_VENDOR_ENCAPSULATED_OPTIONS:
2004 case DHO_NETBIOS_NODE_TYPE:
2005 case DHO_NETBIOS_SCOPE:
2006 case DHO_X_DISPLAY_MANAGER:
2007 case DHO_DHCP_REQUESTED_ADDRESS:
2008 case DHO_DHCP_LEASE_TIME:
2009 case DHO_DHCP_OPTION_OVERLOAD:
2010 case DHO_DHCP_MESSAGE_TYPE:
2011 case DHO_DHCP_PARAMETER_REQUEST_LIST:
2012 case DHO_DHCP_MESSAGE:
2013 case DHO_DHCP_MAX_MESSAGE_SIZE:
2014 case DHO_DHCP_RENEWAL_TIME:
2015 case DHO_DHCP_REBINDING_TIME:
2016 case DHO_DHCP_CLASS_IDENTIFIER:
2017 case DHO_DHCP_CLIENT_IDENTIFIER:
2018 case DHO_DHCP_USER_CLASS_ID:
2019 case DHO_END:
2020 return (1);
2021 default:
2022 warning("unknown dhcp option value 0x%x", option);
2023 return (unknown_ok);
2024 }
2025}
2026
2027int
2028res_hnok(const char *name)
2029{
2030 const char *dn = name;
2031 int pch = '.', ch = *dn++;
2032 int warn = 0;
2033
2034 while (ch != '\0') {
2035 int nch = *dn++;
2036
2037 if (ch == '.') {
2038 ;
2039 } else if (pch == '.' || nch == '.' || nch == '\0') {
2040 if (!isalnum(ch))
2041 return (0);
2042 } else if (!isalnum(ch) && ch != '-' && ch != '_')
2043 return (0);
2044 else if (ch == '_' && warn == 0) {
2045 warning("warning: hostname %s contains an "
2046 "underscore which violates RFC 952", name);
2047 warn++;
2048 }
2049 pch = ch, ch = nch;
2050 }
2051 return (1);
2052}
2053
2054/* Does buf consist only of dotted decimal ipv4 addrs?
2055 * return how many if so,
2056 * otherwise, return 0
2057 */
2058int
2059ipv4addrs(char * buf)
2060{
2061 struct in_addr jnk;
2062 int count = 0;
2063
2064 while (inet_aton(buf, &jnk) == 1){
2065 count++;
2066 while (*buf == '.' || isdigit(*buf))
2067 buf++;
2068 if (*buf == '\0')
2069 return (count);
2070 while (*buf == ' ')
2071 buf++;
2072 }
2073 return (0);
2074}
2075
2076char *
2077option_as_string(unsigned int code, unsigned char *data, int len)
2078{
2079 static char optbuf[32768]; /* XXX */
2080 char *op = optbuf;
2081 int opleft = sizeof(optbuf);
2082 unsigned char *dp = data;
2083
2084 if (code > 255)
2085 error("option_as_string: bad code %d", code);
2086
2087 for (; dp < data + len; dp++) {
2088 if (!isascii(*dp) || !isprint(*dp)) {
2089 if (dp + 1 != data + len || *dp != 0) {
2090 size_t oplen;
2091 snprintf(op, opleft, "\\%03o", *dp);
2092 oplen = strlen(op);
2093 op += oplen;
2094 opleft -= oplen;
2095 }
2096 } else if (*dp == '"' || *dp == '\'' || *dp == '$' ||
2097 *dp == '`' || *dp == '\\') {
2098 *op++ = '\\';
2099 *op++ = *dp;
2100 opleft -= 2;
2101 } else {
2102 *op++ = *dp;
2103 opleft--;
2104 }
2105 }
2106 if (opleft < 1)
2107 goto toobig;
2108 *op = 0;
2109 return optbuf;
2110toobig:
2111 warning("dhcp option too large");
2112 return "<error>";
2113}
2114
2115int
2116fork_privchld(int fd, int fd2)
2117{
2118 struct pollfd pfd[1];
a05d48e6 2119 int nfds, pfail = 0;
846204b6
HT
2120
2121 switch (fork()) {
2122 case -1:
2123 error("cannot fork");
2124 break;
2125 case 0:
2126 break;
2127 default:
2128 return (0);
2129 }
2130
2131 if (chdir("/") == -1)
2132 error("chdir(\"/\")");
2133
2134 setproctitle("%s [priv]", ifi->name);
2135
2136 dup2(nullfd, STDIN_FILENO);
2137 dup2(nullfd, STDOUT_FILENO);
2138 dup2(nullfd, STDERR_FILENO);
2139 close(nullfd);
2140 close(fd2);
2141
2142 for (;;) {
2143 pfd[0].fd = fd;
2144 pfd[0].events = POLLIN;
2145 if ((nfds = poll(pfd, 1, INFTIM)) == -1)
2146 if (errno != EINTR)
2147 error("poll error");
2148
a05d48e6
SG
2149 /*
2150 * Handle temporary errors, but bail if they persist.
2151 */
2152 if (nfds == 0 || !(pfd[0].revents & POLLIN)) {
2153 if (pfail > POLL_FAILURES)
2154 error("poll failed > %d times", POLL_FAILURES);
2155 sleep(pfail * POLL_FAILURE_WAIT);
2156 pfail++;
846204b6 2157 continue;
a05d48e6 2158 }
846204b6
HT
2159
2160 dispatch_imsg(fd);
2161 }
2162}