1 /* $OpenBSD: dhclient.c,v 1.109 2007/02/13 21:54:22 stevesk Exp $ */
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>
59 #include <stdbool.h>
60
61 #include "dhcpd.h"
62 #include "privsep.h"
63
64 __RCSID("$MirOS: src/sbin/dhclient/dhclient.c,v 1.9 2009/07/24 17:22:54 tg Exp $");
65
66 #define CLIENT_PATH "PATH=/usr/bin:/usr/sbin:/bin:/sbin"
67
68 time_t cur_time;
69 time_t default_lease_time = 43200; /* 12 hours... */
70
71 char *path_dhclient_conf = _PATH_DHCLIENT_CONF;
72 char *path_dhclient_db = NULL;
73
74 int log_perror = 1;
75 int privfd;
76 int nullfd = -1;
77 int no_daemon;
78 int unknown_ok = 1;
79 int routefd = -1;
80
81 struct iaddr iaddr_broadcast = { 4, { 255, 255, 255, 255 } };
82 struct in_addr inaddr_any;
83 struct sockaddr_in sockaddr_broadcast;
84
85 #define TIME_MAX 2147483647
86
87 struct interface_info *ifi;
88 struct client_state *client;
89 struct client_config *config;
90
91 int findproto(char *, int);
92 struct sockaddr *get_ifa(char *, int);
93 void usage(void);
94 int check_option(struct client_lease *l, int option);
95 int ipv4addrs(char * buf);
96 int res_hnok(const char *dn, bool wsp_ok);
97 char *option_as_string(unsigned int code, unsigned char *data, int len);
98 int fork_privchld(int, int);
99
100 #define ROUNDUP(a) \
101 ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
102 #define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))
103
104 time_t scripttime;
105
106 int
findproto(char * cp,int n)107 findproto(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
136 struct sockaddr *
get_ifa(char * cp,int n)137 get_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 }
154 struct iaddr defaddr = { 4 };
155
156 /* ARGSUSED */
157 void
routehandler(void)158 routehandler(void)
159 {
160 char msg[2048];
161 struct rt_msghdr *rtm;
162 struct if_msghdr *ifm;
163 struct ifa_msghdr *ifam;
164 struct if_announcemsghdr *ifan;
165 struct client_lease *l;
166 time_t t = time(NULL);
167 struct sockaddr *sa;
168 struct iaddr a;
169 ssize_t n;
170
171 do {
172 n = read(routefd, &msg, sizeof(msg));
173 } while (n == -1 && errno == EINTR);
174
175 rtm = (struct rt_msghdr *)msg;
176 if (n < sizeof(rtm->rtm_msglen) || n < rtm->rtm_msglen ||
177 rtm->rtm_version != RTM_VERSION)
178 return;
179
180 switch (rtm->rtm_type) {
181 case RTM_NEWADDR:
182 ifam = (struct ifa_msghdr *)rtm;
183 if (ifam->ifam_index != ifi->index)
184 break;
185 if (findproto((char *)(ifam + 1), ifam->ifam_addrs) != AF_INET)
186 break;
187 sa = get_ifa((char *)(ifam + 1), ifam->ifam_addrs);
188 if (sa == NULL)
189 goto die;
190
191 if ((a.len = sizeof(struct in_addr)) > sizeof(a.iabuf))
192 error("king bula sez: len mismatch");
193 memcpy(a.iabuf, &((struct sockaddr_in *)sa)->sin_addr, a.len);
194 if (addr_eq(a, defaddr))
195 break;
196
197 for (l = client->active; l != NULL; l = l->next)
198 if (addr_eq(a, l->address))
199 break;
200
201 if (l != NULL || (client->alias &&
202 addr_eq(a, client->alias->address)))
203 /* new addr is the one we set */
204 break;
205
206 goto die;
207 case RTM_DELADDR:
208 ifam = (struct ifa_msghdr *)rtm;
209 if (ifam->ifam_index != ifi->index)
210 break;
211 if (findproto((char *)(ifam + 1), ifam->ifam_addrs) != AF_INET)
212 break;
213 if (scripttime == 0 || t < scripttime + 10)
214 break;
215 goto die;
216 case RTM_IFINFO:
217 ifm = (struct if_msghdr *)rtm;
218 if (ifm->ifm_index != ifi->index)
219 break;
220 if ((rtm->rtm_flags & RTF_UP) == 0)
221 goto die;
222 break;
223 case RTM_IFANNOUNCE:
224 ifan = (struct if_announcemsghdr *)rtm;
225 if (ifan->ifan_what == IFAN_DEPARTURE &&
226 ifan->ifan_index == ifi->index)
227 goto die;
228 break;
229 default:
230 break;
231 }
232 return;
233
234 die:
235 script_init("FAIL", NULL);
236 if (client->alias)
237 script_write_params("alias_", client->alias);
238 script_go();
239 exit(1);
240 }
241
242 int
main(int argc,char * argv[])243 main(int argc, char *argv[])
244 {
245 int ch, fd, quiet = 0, i = 0, pipe_fd[2];
246 extern char *__progname;
247 struct passwd *pw;
248
249 /* Initially, log errors to stderr as well as to syslogd. */
250 openlog(__progname, LOG_PID | LOG_NDELAY, DHCPD_LOG_FACILITY);
251 setlogmask(LOG_UPTO(LOG_INFO));
252
253 while ((ch = getopt(argc, argv, "c:dl:qu")) != -1)
254 switch (ch) {
255 case 'c':
256 path_dhclient_conf = optarg;
257 break;
258 case 'd':
259 no_daemon = 1;
260 break;
261 case 'l':
262 path_dhclient_db = optarg;
263 break;
264 case 'q':
265 quiet = 1;
266 break;
267 case 'u':
268 unknown_ok = 0;
269 break;
270 default:
271 usage();
272 }
273
274 argc -= optind;
275 argv += optind;
276
277 if (argc != 1)
278 usage();
279
280 ifi = calloc(1, sizeof(*ifi));
281 if (ifi == NULL)
282 error("ifi calloc");
283 client = calloc(1, sizeof(*client));
284 if (client == NULL)
285 error("client calloc");
286 config = calloc(1, sizeof(*config));
287 if (config == NULL)
288 error("config calloc");
289
290 if (strlcpy(ifi->name, argv[0], IFNAMSIZ) >= IFNAMSIZ)
291 error("Interface name too long");
292 if (path_dhclient_db == NULL && asprintf(&path_dhclient_db, "%s.%s",
293 _PATH_DHCLIENT_DB, ifi->name) == -1)
294 error("asprintf");
295
296 if (quiet)
297 log_perror = 0;
298
299 tzset();
300 time(&cur_time);
301
302 memset(&sockaddr_broadcast, 0, sizeof(sockaddr_broadcast));
303 sockaddr_broadcast.sin_family = AF_INET;
304 sockaddr_broadcast.sin_port = htons(REMOTE_PORT);
305 sockaddr_broadcast.sin_addr.s_addr = INADDR_BROADCAST;
306 sockaddr_broadcast.sin_len = sizeof(sockaddr_broadcast);
307 inaddr_any.s_addr = INADDR_ANY;
308
309 read_client_conf();
310
311 if (!interface_link_status(ifi->name)) {
312 int linkstat = interface_link_forceup(ifi->name);
313
314 fprintf(stderr, "%s: no link ...", ifi->name);
315 if (config->link_timeout == 0) {
316 fprintf(stderr, " giving up\n");
317 if (linkstat == 0)
318 interface_link_forcedown(ifi->name);
319 exit(1);
320 }
321 fflush(stderr);
322 sleep(1);
323 while (!interface_link_status(ifi->name)) {
324 fprintf(stderr, ".");
325 fflush(stderr);
326 if (++i > config->link_timeout) {
327 fprintf(stderr, " giving up\n");
328 if (linkstat == 0)
329 interface_link_forcedown(ifi->name);
330 exit(1);
331 }
332 sleep(1);
333 }
334 fprintf(stderr, " got link\n");
335 }
336
337 if ((nullfd = open(_PATH_DEVNULL, O_RDWR, 0)) == -1)
338 error("cannot open %s: %m", _PATH_DEVNULL);
339
340 if ((pw = getpwnam("_dhcp")) == NULL) {
341 warning("no such user: _dhcp, falling back to \"nobody\"");
342 if ((pw = getpwnam("nobody")) == NULL)
343 error("no such user: nobody");
344 }
345
346 if (pipe(pipe_fd) == -1)
347 error("pipe");
348
349 fork_privchld(pipe_fd[0], pipe_fd[1]);
350
351 close(pipe_fd[0]);
352 privfd = pipe_fd[1];
353
354 if ((fd = open(path_dhclient_db, O_RDONLY|O_EXLOCK|O_CREAT, 0)) == -1)
355 error("can't open and lock %s: %m", path_dhclient_db);
356 read_client_leases();
357 rewrite_client_leases();
358 close(fd);
359
360 priv_script_init("PREINIT", NULL);
361 if (client->alias)
362 priv_script_write_params("alias_", client->alias);
363 priv_script_go();
364
365 if ((routefd = socket(PF_ROUTE, SOCK_RAW, 0)) == -1)
366 error("socket(PF_ROUTE, SOCK_RAW): %m");
367
368 /* set up the interface */
369 discover_interface();
370
371 if (chroot(_PATH_VAREMPTY) == -1)
372 error("chroot");
373 if (chdir("/") == -1)
374 error("chdir(\"/\")");
375
376 if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1)
377 error("setresgid");
378 if (setgroups(1, &pw->pw_gid) == -1)
379 error("setgroups");
380 if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1)
381 error("setresuid");
382
383 endpwent();
384
385 setproctitle("%s", ifi->name);
386
387 client->state = S_INIT;
388 state_reboot();
389
390 dispatch();
391
392 /* not reached */
393 return (0);
394 }
395
396 void
usage(void)397 usage(void)
398 {
399 extern char *__progname;
400
401 fprintf(stderr, "usage: %s [-dqu] ", __progname);
402 fprintf(stderr, "[-c conffile] [-l leasefile] interface\n");
403 exit(1);
404 }
405
406 /*
407 * Individual States:
408 *
409 * Each routine is called from the dhclient_state_machine() in one of
410 * these conditions:
411 * -> entering INIT state
412 * -> recvpacket_flag == 0: timeout in this state
413 * -> otherwise: received a packet in this state
414 *
415 * Return conditions as handled by dhclient_state_machine():
416 * Returns 1, sendpacket_flag = 1: send packet, reset timer.
417 * Returns 1, sendpacket_flag = 0: just reset the timer (wait for a milestone).
418 * Returns 0: finish the nap which was interrupted for no good reason.
419 *
420 * Several per-interface variables are used to keep track of the process:
421 * active_lease: the lease that is being used on the interface
422 * (null pointer if not configured yet).
423 * offered_leases: leases corresponding to DHCPOFFER messages that have
424 * been sent to us by DHCP servers.
425 * acked_leases: leases corresponding to DHCPACK messages that have been
426 * sent to us by DHCP servers.
427 * sendpacket: DHCP packet we're trying to send.
428 * destination: IP address to send sendpacket to
429 * In addition, there are several relevant per-lease variables.
430 * T1_expiry, T2_expiry, lease_expiry: lease milestones
431 * In the active lease, these control the process of renewing the lease;
432 * In leases on the acked_leases list, this simply determines when we
433 * can no longer legitimately use the lease.
434 */
435 void
state_reboot(void)436 state_reboot(void)
437 {
438 /* If we don't remember an active lease, go straight to INIT. */
439 if (!client->active || client->active->is_bootp) {
440 state_init();
441 return;
442 }
443
444 /* We are in the rebooting state. */
445 client->state = S_REBOOTING;
446
447 /* make_request doesn't initialize xid because it normally comes
448 from the DHCPDISCOVER, but we haven't sent a DHCPDISCOVER,
449 so pick an xid now. */
450 client->xid = arc4random();
451
452 /* Make a DHCPREQUEST packet, and set appropriate per-interface
453 flags. */
454 make_request(client->active);
455 client->destination = iaddr_broadcast;
456 client->first_sending = cur_time;
457 client->interval = config->initial_interval;
458
459 /* Zap the medium list... */
460 client->medium = NULL;
461
462 /* Send out the first DHCPREQUEST packet. */
463 send_request();
464 }
465
466 /*
467 * Called when a lease has completely expired and we've
468 * been unable to renew it.
469 */
470 void
state_init(void)471 state_init(void)
472 {
473 /* Make a DHCPDISCOVER packet, and set appropriate per-interface
474 flags. */
475 make_discover(client->active);
476 client->xid = client->packet.xid;
477 client->destination = iaddr_broadcast;
478 client->state = S_SELECTING;
479 client->first_sending = cur_time;
480 client->interval = config->initial_interval;
481
482 /* Add an immediate timeout to cause the first DHCPDISCOVER packet
483 to go out. */
484 send_discover();
485 }
486
487 /*
488 * state_selecting is called when one or more DHCPOFFER packets
489 * have been received and a configurable period of time has passed.
490 */
491 void
state_selecting(void)492 state_selecting(void)
493 {
494 struct client_lease *lp, *next, *picked;
495
496 /* Cancel state_selecting and send_discover timeouts, since either
497 one could have got us here. */
498 cancel_timeout(state_selecting);
499 cancel_timeout(send_discover);
500
501 /* We have received one or more DHCPOFFER packets. Currently,
502 the only criterion by which we judge leases is whether or
503 not we get a response when we arp for them. */
504 picked = NULL;
505 for (lp = client->offered_leases; lp; lp = next) {
506 next = lp->next;
507
508 /* Check to see if we got an ARPREPLY for the address
509 in this particular lease. */
510 if (!picked) {
511 script_init("ARPCHECK", lp->medium);
512 script_write_params("check_", lp);
513
514 /* If the ARPCHECK code detects another
515 machine using the offered address, it exits
516 nonzero. We need to send a DHCPDECLINE and
517 toss the lease. */
518 if (script_go()) {
519 make_decline(lp);
520 send_decline();
521 goto freeit;
522 }
523 picked = lp;
524 picked->next = NULL;
525 } else {
526 freeit:
527 free_client_lease(lp);
528 }
529 }
530 client->offered_leases = NULL;
531
532 /* If we just tossed all the leases we were offered, go back
533 to square one. */
534 if (!picked) {
535 client->state = S_INIT;
536 state_init();
537 return;
538 }
539
540 /* If it was a BOOTREPLY, we can just take the address right now. */
541 if (!picked->options[DHO_DHCP_MESSAGE_TYPE].len) {
542 client->new = picked;
543
544 /* Make up some lease expiry times
545 XXX these should be configurable. */
546 client->new->expiry = cur_time + 12000;
547 client->new->renewal += cur_time + 8000;
548 client->new->rebind += cur_time + 10000;
549
550 client->state = S_REQUESTING;
551
552 /* Bind to the address we received. */
553 bind_lease();
554 return;
555 }
556
557 /* Go to the REQUESTING state. */
558 client->destination = iaddr_broadcast;
559 client->state = S_REQUESTING;
560 client->first_sending = cur_time;
561 client->interval = config->initial_interval;
562
563 /* Make a DHCPREQUEST packet from the lease we picked. */
564 make_request(picked);
565 client->xid = client->packet.xid;
566
567 /* Toss the lease we picked - we'll get it back in a DHCPACK. */
568 free_client_lease(picked);
569
570 /* Add an immediate timeout to send the first DHCPREQUEST packet. */
571 send_request();
572 }
573
574 /*
575 * state_requesting is called when we receive a DHCPACK message after
576 * having sent out one or more DHCPREQUEST packets.
577 */
578 void
dhcpack(struct iaddr client_addr,struct option_data * options)579 dhcpack(struct iaddr client_addr, struct option_data *options)
580 {
581 struct client_lease *lease;
582
583 if (client->xid != client->packet.xid)
584 return;
585
586 if (client->state != S_REBOOTING &&
587 client->state != S_REQUESTING &&
588 client->state != S_RENEWING &&
589 client->state != S_REBINDING)
590 return;
591
592 note("DHCPACK from %s", piaddr(client_addr));
593
594 lease = packet_to_lease(client_addr, options);
595 if (!lease) {
596 note("packet_to_lease failed.");
597 return;
598 }
599
600 client->new = lease;
601
602 /* Stop resending DHCPREQUEST. */
603 cancel_timeout(send_request);
604
605 /* Figure out the lease time. */
606 if (client->new->options[DHO_DHCP_LEASE_TIME].data)
607 client->new->expiry =
608 getULong(client->new->options[DHO_DHCP_LEASE_TIME].data);
609 else
610 client->new->expiry = default_lease_time;
611 /* A number that looks negative here is really just very large,
612 because the lease expiry offset is unsigned. */
613 if (client->new->expiry < 0)
614 client->new->expiry = TIME_MAX;
615 /* XXX should be fixed by resetting the client state */
616 if (client->new->expiry < 60)
617 client->new->expiry = 60;
618
619 /* Take the server-provided renewal time if there is one;
620 otherwise figure it out according to the spec. */
621 if (client->new->options[DHO_DHCP_RENEWAL_TIME].len)
622 client->new->renewal =
623 getULong(client->new->options[DHO_DHCP_RENEWAL_TIME].data);
624 else
625 client->new->renewal = client->new->expiry / 2;
626
627 /* Same deal with the rebind time. */
628 if (client->new->options[DHO_DHCP_REBINDING_TIME].len)
629 client->new->rebind =
630 getULong(client->new->options[DHO_DHCP_REBINDING_TIME].data);
631 else
632 client->new->rebind = client->new->renewal +
633 client->new->renewal / 2 + client->new->renewal / 4;
634
635 client->new->expiry += cur_time;
636 /* Lease lengths can never be negative. */
637 if (client->new->expiry < cur_time)
638 client->new->expiry = TIME_MAX;
639 client->new->renewal += cur_time;
640 if (client->new->renewal < cur_time)
641 client->new->renewal = TIME_MAX;
642 client->new->rebind += cur_time;
643 if (client->new->rebind < cur_time)
644 client->new->rebind = TIME_MAX;
645
646 bind_lease();
647 }
648
649 void
bind_lease(void)650 bind_lease(void)
651 {
652 /* Remember the medium. */
653 client->new->medium = client->medium;
654
655 /* Write out the new lease. */
656 write_client_lease(client->new, 0);
657
658 /* Run the client script with the new parameters. */
659 script_init((client->state == S_REQUESTING ? "BOUND" :
660 (client->state == S_RENEWING ? "RENEW" :
661 (client->state == S_REBOOTING ? "REBOOT" : "REBIND"))),
662 client->new->medium);
663 if (client->active && client->state != S_REBOOTING)
664 script_write_params("old_", client->active);
665 script_write_params("new_", client->new);
666 if (client->alias)
667 script_write_params("alias_", client->alias);
668 script_go();
669
670 /* Replace the old active lease with the new one. */
671 if (client->active)
672 free_client_lease(client->active);
673 client->active = client->new;
674 client->new = NULL;
675
676 /* Set up a timeout to start the renewal process. */
677 add_timeout(client->active->renewal, state_bound);
678
679 note("bound to %s -- renewal in %ld seconds.",
680 piaddr(client->active->address),
681 (long)(client->active->renewal - cur_time));
682 client->state = S_BOUND;
683 reinitialize_interface();
684 go_daemon();
685 }
686
687 /*
688 * state_bound is called when we've successfully bound to a particular
689 * lease, but the renewal time on that lease has expired. We are
690 * expected to unicast a DHCPREQUEST to the server that gave us our
691 * original lease.
692 */
693 void
state_bound(void)694 state_bound(void)
695 {
696 /* T1 has expired. */
697 make_request(client->active);
698 client->xid = client->packet.xid;
699
700 if (client->active->options[DHO_DHCP_SERVER_IDENTIFIER].len == 4) {
701 memcpy(client->destination.iabuf,
702 client->active->options[DHO_DHCP_SERVER_IDENTIFIER].data,
703 4);
704 client->destination.len = 4;
705 } else
706 client->destination = iaddr_broadcast;
707
708 client->first_sending = cur_time;
709 client->interval = config->initial_interval;
710 client->state = S_RENEWING;
711
712 /* Send the first packet immediately. */
713 send_request();
714 }
715
716 void
dhcpoffer(struct iaddr client_addr,struct option_data * options)717 dhcpoffer(struct iaddr client_addr, struct option_data *options)
718 {
719 struct client_lease *lease, *lp;
720 int i;
721 int arp_timeout_needed, stop_selecting;
722 char *name = options[DHO_DHCP_MESSAGE_TYPE].len ? "DHCPOFFER" :
723 "BOOTREPLY";
724
725 if (client->xid != client->packet.xid)
726 return;
727
728 if (client->state != S_SELECTING)
729 return;
730
731 note("%s from %s", name, piaddr(client_addr));
732
733 /* If this lease doesn't supply the minimum required parameters,
734 blow it off. */
735 for (i = 0; config->required_options[i]; i++) {
736 if (!options[config->required_options[i]].len) {
737 note("%s isn't satisfactory.", name);
738 return;
739 }
740 }
741
742 /* If we've already seen this lease, don't record it again. */
743 for (lease = client->offered_leases;
744 lease; lease = lease->next) {
745 if (lease->address.len == sizeof(client->packet.yiaddr) &&
746 !memcmp(lease->address.iabuf,
747 &client->packet.yiaddr, lease->address.len)) {
748 debug("%s already seen.", name);
749 return;
750 }
751 }
752
753 lease = packet_to_lease(client_addr, options);
754 if (!lease) {
755 note("packet_to_lease failed.");
756 return;
757 }
758
759 /* If this lease was acquired through a BOOTREPLY, record that
760 fact. */
761 if (!options[DHO_DHCP_MESSAGE_TYPE].len)
762 lease->is_bootp = 1;
763
764 /* Record the medium under which this lease was offered. */
765 lease->medium = client->medium;
766
767 /* Send out an ARP Request for the offered IP address. */
768 script_init("ARPSEND", lease->medium);
769 script_write_params("check_", lease);
770 /* If the script can't send an ARP request without waiting,
771 we'll be waiting when we do the ARPCHECK, so don't wait now. */
772 if (script_go())
773 arp_timeout_needed = 0;
774 else
775 arp_timeout_needed = 2;
776
777 /* Figure out when we're supposed to stop selecting. */
778 stop_selecting = client->first_sending + config->select_interval;
779
780 /* If this is the lease we asked for, put it at the head of the
781 list, and don't mess with the arp request timeout. */
782 if (lease->address.len == client->requested_address.len &&
783 !memcmp(lease->address.iabuf,
784 client->requested_address.iabuf,
785 client->requested_address.len)) {
786 lease->next = client->offered_leases;
787 client->offered_leases = lease;
788 } else {
789 /* If we already have an offer, and arping for this
790 offer would take us past the selection timeout,
791 then don't extend the timeout - just hope for the
792 best. */
793 if (client->offered_leases &&
794 (cur_time + arp_timeout_needed) > stop_selecting)
795 arp_timeout_needed = 0;
796
797 /* Put the lease at the end of the list. */
798 lease->next = NULL;
799 if (!client->offered_leases)
800 client->offered_leases = lease;
801 else {
802 for (lp = client->offered_leases; lp->next;
803 lp = lp->next)
804 ; /* nothing */
805 lp->next = lease;
806 }
807 }
808
809 /* If we're supposed to stop selecting before we've had time
810 to wait for the ARPREPLY, add some delay to wait for
811 the ARPREPLY. */
812 if (stop_selecting - cur_time < arp_timeout_needed)
813 stop_selecting = cur_time + arp_timeout_needed;
814
815 /* If the selecting interval has expired, go immediately to
816 state_selecting(). Otherwise, time out into
817 state_selecting at the select interval. */
818 if (stop_selecting <= 0)
819 state_selecting();
820 else {
821 add_timeout(stop_selecting, state_selecting);
822 cancel_timeout(send_discover);
823 }
824 }
825
826 /*
827 * Allocate a client_lease structure and initialize it from the
828 * parameters in the specified packet.
829 */
830 struct client_lease *
packet_to_lease(struct iaddr client_addr,struct option_data * options)831 packet_to_lease(struct iaddr client_addr, struct option_data *options)
832 {
833 struct client_lease *lease;
834 int i;
835
836 lease = malloc(sizeof(struct client_lease));
837
838 if (!lease) {
839 warning("dhcpoffer: no memory to record lease.");
840 return (NULL);
841 }
842
843 memset(lease, 0, sizeof(*lease));
844
845 /* Copy the lease options. */
846 for (i = 0; i < 256; i++) {
847 if (options[i].len) {
848 lease->options[i] = options[i];
849 options[i].data = NULL;
850 options[i].len = 0;
851 if (!check_option(lease, i)) {
852 warning("Invalid lease option - ignoring offer");
853 free_client_lease(lease);
854 return (NULL);
855 }
856 }
857 }
858
859 lease->address.len = sizeof(client->packet.yiaddr);
860 memcpy(lease->address.iabuf, &client->packet.yiaddr,
861 lease->address.len);
862
863 /* If the server name was filled out, copy it. */
864 if ((!options[DHO_DHCP_OPTION_OVERLOAD].len ||
865 !(options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 2)) &&
866 client->packet.sname[0]) {
867 lease->server_name = malloc(DHCP_SNAME_LEN + 1);
868 if (!lease->server_name) {
869 warning("dhcpoffer: no memory for server name.");
870 free_client_lease(lease);
871 return (NULL);
872 }
873 memcpy(lease->server_name, client->packet.sname,
874 DHCP_SNAME_LEN);
875 lease->server_name[DHCP_SNAME_LEN] = '\0';
876 if (!res_hnok(lease->server_name, false)) {
877 warning("Bogus server name %s", lease->server_name);
878 free(lease->server_name);
879 lease->server_name = NULL;
880 }
881 }
882
883 /* Ditto for the filename. */
884 if ((!options[DHO_DHCP_OPTION_OVERLOAD].len ||
885 !(options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 1)) &&
886 client->packet.file[0]) {
887 /* Don't count on the NUL terminator. */
888 lease->filename = malloc(DHCP_FILE_LEN + 1);
889 if (!lease->filename) {
890 warning("dhcpoffer: no memory for filename.");
891 free_client_lease(lease);
892 return (NULL);
893 }
894 memcpy(lease->filename, client->packet.file, DHCP_FILE_LEN);
895 lease->filename[DHCP_FILE_LEN] = '\0';
896 }
897 return lease;
898 }
899
900 void
dhcpnak(struct iaddr client_addr,struct option_data * options)901 dhcpnak(struct iaddr client_addr, struct option_data *options)
902 {
903 if (client->xid != client->packet.xid)
904 return;
905
906 if (client->state != S_REBOOTING &&
907 client->state != S_REQUESTING &&
908 client->state != S_RENEWING &&
909 client->state != S_REBINDING)
910 return;
911
912 note("DHCPNAK from %s", piaddr(client_addr));
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 */
934 void
send_discover(void)935 send_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;
954 again:
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), (long)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 */
1026 void
state_panic(void)1027 state_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 (long)(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
1083 activate_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
1116 void
send_request(void)1117 send_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) {
1139 cancel:
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
1240 void
send_decline(void)1241 send_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
1251 void
make_discover(struct client_lease * lease)1252 make_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
1313 void
make_request(struct client_lease * lease)1314 make_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
1393 void
make_decline(struct client_lease * lease)1394 make_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
1451 void
free_client_lease(struct client_lease * lease)1452 free_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
1467 FILE *leaseFile;
1468
1469 void
rewrite_client_leases(void)1470 rewrite_client_leases(void)
1471 {
1472 struct client_lease *lp;
1473
1474 if (!leaseFile) {
1475 leaseFile = fopen(path_dhclient_db, "w");
1476 if (!leaseFile)
1477 error("can't create %s: %m", path_dhclient_db);
1478 } else {
1479 fflush(leaseFile);
1480 rewind(leaseFile);
1481 }
1482
1483 for (lp = client->leases; lp; lp = lp->next)
1484 write_client_lease(lp, 1);
1485 if (client->active)
1486 write_client_lease(client->active, 1);
1487
1488 fflush(leaseFile);
1489 ftruncate(fileno(leaseFile), ftello(leaseFile));
1490 fsync(fileno(leaseFile));
1491 }
1492
1493 void
write_client_lease(struct client_lease * lease,int rewrite)1494 write_client_lease(struct client_lease *lease, int rewrite)
1495 {
1496 static int leases_written;
1497 struct tm *t;
1498 int i;
1499
1500 if (!rewrite) {
1501 if (leases_written++ > 20) {
1502 rewrite_client_leases();
1503 leases_written = 0;
1504 }
1505 }
1506
1507 /* If the lease came from the config file, we don't need to stash
1508 a copy in the lease database. */
1509 if (lease->is_static)
1510 return;
1511
1512 if (!leaseFile) { /* XXX */
1513 leaseFile = fopen(path_dhclient_db, "w");
1514 if (!leaseFile)
1515 error("can't create %s: %m", path_dhclient_db);
1516 }
1517
1518 fprintf(leaseFile, "lease {\n");
1519 if (lease->is_bootp)
1520 fprintf(leaseFile, " bootp;\n");
1521 fprintf(leaseFile, " interface \"%s\";\n", ifi->name);
1522 fprintf(leaseFile, " fixed-address %s;\n", piaddr(lease->address));
1523 if (lease->filename)
1524 fprintf(leaseFile, " filename \"%s\";\n", lease->filename);
1525 if (lease->server_name)
1526 fprintf(leaseFile, " server-name \"%s\";\n",
1527 lease->server_name);
1528 if (lease->medium)
1529 fprintf(leaseFile, " medium \"%s\";\n", lease->medium->string);
1530 for (i = 0; i < 256; i++)
1531 if (lease->options[i].len)
1532 fprintf(leaseFile, " option %s %s;\n",
1533 dhcp_options[i].name,
1534 pretty_print_option(i, lease->options[i].data,
1535 lease->options[i].len, 1, 1));
1536
1537 t = gmtime(&lease->renewal);
1538 fprintf(leaseFile, " renew %d %d/%d/%d %02d:%02d:%02d;\n",
1539 t->tm_wday, (int)t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1540 t->tm_hour, t->tm_min, t->tm_sec);
1541 t = gmtime(&lease->rebind);
1542 fprintf(leaseFile, " rebind %d %d/%d/%d %02d:%02d:%02d;\n",
1543 t->tm_wday, (int)t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1544 t->tm_hour, t->tm_min, t->tm_sec);
1545 t = gmtime(&lease->expiry);
1546 fprintf(leaseFile, " expire %d %d/%d/%d %02d:%02d:%02d;\n",
1547 t->tm_wday, (int)t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1548 t->tm_hour, t->tm_min, t->tm_sec);
1549 fprintf(leaseFile, "}\n");
1550 fflush(leaseFile);
1551 }
1552
1553 void
script_init(char * reason,struct string_list * medium)1554 script_init(char *reason, struct string_list *medium)
1555 {
1556 size_t len, mediumlen = 0;
1557 struct imsg_hdr hdr;
1558 struct buf *buf;
1559
1560 if (medium != NULL && medium->string != NULL)
1561 mediumlen = strlen(medium->string);
1562
1563 hdr.code = IMSG_SCRIPT_INIT;
1564 hdr.len = sizeof(struct imsg_hdr) +
1565 sizeof(size_t) + mediumlen +
1566 sizeof(size_t) + strlen(reason);
1567
1568 buf = buf_open(hdr.len);
1569
1570 buf_add(buf, &hdr, sizeof(hdr));
1571 buf_add(buf, &mediumlen, sizeof(mediumlen));
1572 if (mediumlen > 0)
1573 buf_add(buf, medium->string, mediumlen);
1574 len = strlen(reason);
1575 buf_add(buf, &len, sizeof(len));
1576 buf_add(buf, reason, len);
1577
1578 buf_close(privfd, buf);
1579 }
1580
1581 void
priv_script_init(char * reason,char * medium)1582 priv_script_init(char *reason, char *medium)
1583 {
1584 client->scriptEnvsize = 100;
1585 if (client->scriptEnv == NULL)
1586 client->scriptEnv =
1587 malloc(client->scriptEnvsize * sizeof(char *));
1588 if (client->scriptEnv == NULL)
1589 error("script_init: no memory for environment");
1590
1591 client->scriptEnv[0] = strdup(CLIENT_PATH);
1592 if (client->scriptEnv[0] == NULL)
1593 error("script_init: no memory for environment");
1594
1595 client->scriptEnv[1] = NULL;
1596
1597 script_set_env("", "interface", ifi->name);
1598
1599 if (medium)
1600 script_set_env("", "medium", medium);
1601
1602 script_set_env("", "reason", reason);
1603 }
1604
1605 void
priv_script_write_params(char * prefix,struct client_lease * lease)1606 priv_script_write_params(char *prefix, struct client_lease *lease)
1607 {
1608 u_int8_t dbuf[1500];
1609 int i, len = 0;
1610 char tbuf[128];
1611
1612 script_set_env(prefix, "ip_address", piaddr(lease->address));
1613
1614 if (lease->options[DHO_SUBNET_MASK].len &&
1615 (lease->options[DHO_SUBNET_MASK].len <
1616 sizeof(lease->address.iabuf))) {
1617 struct iaddr netmask, subnet, broadcast;
1618
1619 memcpy(netmask.iabuf, lease->options[DHO_SUBNET_MASK].data,
1620 lease->options[DHO_SUBNET_MASK].len);
1621 netmask.len = lease->options[DHO_SUBNET_MASK].len;
1622
1623 subnet = subnet_number(lease->address, netmask);
1624 if (subnet.len) {
1625 script_set_env(prefix, "network_number",
1626 piaddr(subnet));
1627 if (!lease->options[DHO_BROADCAST_ADDRESS].len) {
1628 broadcast = broadcast_addr(subnet, netmask);
1629 if (broadcast.len)
1630 script_set_env(prefix,
1631 "broadcast_address",
1632 piaddr(broadcast));
1633 }
1634 }
1635 }
1636
1637 if (lease->filename)
1638 script_set_env(prefix, "filename", lease->filename);
1639 if (lease->server_name)
1640 script_set_env(prefix, "server_name",
1641 lease->server_name);
1642 for (i = 0; i < 256; i++) {
1643 u_int8_t *dp = NULL;
1644
1645 if (config->defaults[i].len) {
1646 if (lease->options[i].len) {
1647 switch (config->default_actions[i]) {
1648 case ACTION_DEFAULT:
1649 dp = lease->options[i].data;
1650 len = lease->options[i].len;
1651 break;
1652 case ACTION_SUPERSEDE:
1653 supersede:
1654 dp = config->defaults[i].data;
1655 len = config->defaults[i].len;
1656 break;
1657 case ACTION_PREPEND:
1658 len = config->defaults[i].len +
1659 lease->options[i].len;
1660 if (len > sizeof(dbuf)) {
1661 warning("no space to %s %s",
1662 "prepend option",
1663 dhcp_options[i].name);
1664 goto supersede;
1665 }
1666 dp = dbuf;
1667 memcpy(dp,
1668 config->defaults[i].data,
1669 config->defaults[i].len);
1670 memcpy(dp +
1671 config->defaults[i].len,
1672 lease->options[i].data,
1673 lease->options[i].len);
1674 dp[len] = '\0';
1675 break;
1676 case ACTION_APPEND:
1677 len = config->defaults[i].len +
1678 lease->options[i].len;
1679 if (len > sizeof(dbuf)) {
1680 warning("no space to %s %s",
1681 "append option",
1682 dhcp_options[i].name);
1683 goto supersede;
1684 }
1685 dp = dbuf;
1686 memcpy(dp, lease->options[i].data,
1687 lease->options[i].len);
1688 memcpy(dp + lease->options[i].len,
1689 config->defaults[i].data,
1690 config->defaults[i].len);
1691 dp[len] = '\0';
1692 }
1693 } else {
1694 dp = config->defaults[i].data;
1695 len = config->defaults[i].len;
1696 }
1697 } else if (lease->options[i].len) {
1698 len = lease->options[i].len;
1699 dp = lease->options[i].data;
1700 } else {
1701 len = 0;
1702 }
1703 if (len) {
1704 char name[256];
1705
1706 if (dhcp_option_ev_name(name, sizeof(name),
1707 &dhcp_options[i]))
1708 script_set_env(prefix, name,
1709 pretty_print_option(i, dp, len, 0, 0));
1710 }
1711 }
1712 snprintf(tbuf, sizeof(tbuf), "%d", (int)lease->expiry);
1713 script_set_env(prefix, "expiry", tbuf);
1714 }
1715
1716 void
script_write_params(char * prefix,struct client_lease * lease)1717 script_write_params(char *prefix, struct client_lease *lease)
1718 {
1719 size_t fn_len = 0, sn_len = 0, pr_len = 0;
1720 struct imsg_hdr hdr;
1721 struct buf *buf;
1722 int i;
1723
1724 if (lease->filename != NULL)
1725 fn_len = strlen(lease->filename);
1726 if (lease->server_name != NULL)
1727 sn_len = strlen(lease->server_name);
1728 if (prefix != NULL)
1729 pr_len = strlen(prefix);
1730
1731 hdr.code = IMSG_SCRIPT_WRITE_PARAMS;
1732 hdr.len = sizeof(hdr) + sizeof(struct client_lease) +
1733 sizeof(size_t) + fn_len + sizeof(size_t) + sn_len +
1734 sizeof(size_t) + pr_len;
1735
1736 for (i = 0; i < 256; i++)
1737 hdr.len += sizeof(int) + lease->options[i].len;
1738
1739 scripttime = time(NULL);
1740
1741 buf = buf_open(hdr.len);
1742
1743 buf_add(buf, &hdr, sizeof(hdr));
1744 buf_add(buf, lease, sizeof(struct client_lease));
1745 buf_add(buf, &fn_len, sizeof(fn_len));
1746 buf_add(buf, lease->filename, fn_len);
1747 buf_add(buf, &sn_len, sizeof(sn_len));
1748 buf_add(buf, lease->server_name, sn_len);
1749 buf_add(buf, &pr_len, sizeof(pr_len));
1750 buf_add(buf, prefix, pr_len);
1751
1752 for (i = 0; i < 256; i++) {
1753 buf_add(buf, &lease->options[i].len,
1754 sizeof(lease->options[i].len));
1755 buf_add(buf, lease->options[i].data,
1756 lease->options[i].len);
1757 }
1758
1759 buf_close(privfd, buf);
1760 }
1761
1762 int
script_go(void)1763 script_go(void)
1764 {
1765 struct imsg_hdr hdr;
1766 struct buf *buf;
1767 int ret;
1768
1769 scripttime = time(NULL);
1770
1771 hdr.code = IMSG_SCRIPT_GO;
1772 hdr.len = sizeof(struct imsg_hdr);
1773
1774 buf = buf_open(hdr.len);
1775
1776 buf_add(buf, &hdr, sizeof(hdr));
1777 buf_close(privfd, buf);
1778
1779 bzero(&hdr, sizeof(hdr));
1780 buf_read(privfd, &hdr, sizeof(hdr));
1781 if (hdr.code != IMSG_SCRIPT_GO_RET)
1782 error("unexpected msg type %u", hdr.code);
1783 if (hdr.len != sizeof(hdr) + sizeof(int))
1784 error("received corrupted message");
1785 buf_read(privfd, &ret, sizeof(ret));
1786
1787 return (ret);
1788 }
1789
1790 int
priv_script_go(void)1791 priv_script_go(void)
1792 {
1793 char *scriptName, *argv[2], **envp;
1794 int pid, wpid, wstatus;
1795
1796 scripttime = time(NULL);
1797
1798 scriptName = config->script_name;
1799 envp = client->scriptEnv;
1800
1801 argv[0] = scriptName;
1802 argv[1] = NULL;
1803
1804 pid = fork();
1805 if (pid < 0) {
1806 error("fork: %m");
1807 wstatus = 0;
1808 } else if (pid) {
1809 do {
1810 wpid = wait(&wstatus);
1811 } while (wpid != pid && wpid > 0);
1812 if (wpid < 0) {
1813 error("wait: %m");
1814 wstatus = 0;
1815 }
1816 } else {
1817 execve(scriptName, argv, envp);
1818 error("execve (%s, ...): %m", scriptName);
1819 }
1820
1821 script_flush_env();
1822
1823 return (wstatus & 0xff);
1824 }
1825
1826 void
script_set_env(const char * prefix,const char * name,const char * value)1827 script_set_env(const char *prefix, const char *name, const char *value)
1828 {
1829 int i, j, namelen;
1830
1831 namelen = strlen(name);
1832
1833 for (i = 0; client->scriptEnv[i]; i++)
1834 if (strncmp(client->scriptEnv[i], name, namelen) == 0 &&
1835 client->scriptEnv[i][namelen] == '=')
1836 break;
1837
1838 if (client->scriptEnv[i])
1839 /* Reuse the slot. */
1840 free(client->scriptEnv[i]);
1841 else {
1842 /* New variable. Expand if necessary. */
1843 if (i >= client->scriptEnvsize - 1) {
1844 char **newscriptEnv;
1845 int newscriptEnvsize = client->scriptEnvsize + 50;
1846
1847 newscriptEnv = realloc(client->scriptEnv,
1848 newscriptEnvsize);
1849 if (newscriptEnv == NULL) {
1850 free(client->scriptEnv);
1851 client->scriptEnv = NULL;
1852 client->scriptEnvsize = 0;
1853 error("script_set_env: no memory for variable");
1854 }
1855 client->scriptEnv = newscriptEnv;
1856 client->scriptEnvsize = newscriptEnvsize;
1857 }
1858 /* need to set the NULL pointer at end of array beyond
1859 the new slot. */
1860 client->scriptEnv[i + 1] = NULL;
1861 }
1862 /* Allocate space and format the variable in the appropriate slot. */
1863 client->scriptEnv[i] = malloc(strlen(prefix) + strlen(name) + 1 +
1864 strlen(value) + 1);
1865 if (client->scriptEnv[i] == NULL)
1866 error("script_set_env: no memory for variable assignment");
1867
1868 /* No `` or $() command substitution allowed in environment values! */
1869 for (j = 0; j < strlen(value); j++)
1870 switch (value[j]) {
1871 case '`':
1872 case '$':
1873 error("illegal character (%c) in value '%s'", value[j],
1874 value);
1875 /* not reached */
1876 }
1877 snprintf(client->scriptEnv[i], strlen(prefix) + strlen(name) +
1878 1 + strlen(value) + 1, "%s%s=%s", prefix, name, value);
1879 }
1880
1881 void
script_flush_env(void)1882 script_flush_env(void)
1883 {
1884 int i;
1885
1886 for (i = 0; client->scriptEnv[i]; i++) {
1887 free(client->scriptEnv[i]);
1888 client->scriptEnv[i] = NULL;
1889 }
1890 client->scriptEnvsize = 0;
1891 }
1892
1893 int
dhcp_option_ev_name(char * buf,size_t buflen,const struct option * option)1894 dhcp_option_ev_name(char *buf, size_t buflen, const struct option *option)
1895 {
1896 int i;
1897
1898 for (i = 0; option->name[i]; i++) {
1899 if (i + 1 == buflen)
1900 return 0;
1901 if (option->name[i] == '-')
1902 buf[i] = '_';
1903 else
1904 buf[i] = option->name[i];
1905 }
1906
1907 buf[i] = 0;
1908 return 1;
1909 }
1910
1911 void
go_daemon(void)1912 go_daemon(void)
1913 {
1914 static int state = 0;
1915
1916 if (no_daemon || state)
1917 return;
1918
1919 state = 1;
1920
1921 /* Stop logging to stderr... */
1922 log_perror = 0;
1923
1924 if (daemon(1, 0) == -1)
1925 error("daemon");
1926
1927 /* we are chrooted, daemon(3) fails to open /dev/null */
1928 if (nullfd != -1) {
1929 dup2(nullfd, STDIN_FILENO);
1930 dup2(nullfd, STDOUT_FILENO);
1931 dup2(nullfd, STDERR_FILENO);
1932 close(nullfd);
1933 nullfd = -1;
1934 }
1935 }
1936
1937 int
check_option(struct client_lease * l,int option)1938 check_option(struct client_lease *l, int option)
1939 {
1940 char *opbuf;
1941 char *sbuf;
1942
1943 /* we use this, since this is what gets passed to dhclient-script */
1944
1945 opbuf = pretty_print_option(option, l->options[option].data,
1946 l->options[option].len, 0, 0);
1947
1948 sbuf = option_as_string(option, l->options[option].data,
1949 l->options[option].len);
1950
1951 switch (option) {
1952 case DHO_SUBNET_MASK:
1953 case DHO_TIME_SERVERS:
1954 case DHO_NAME_SERVERS:
1955 case DHO_ROUTERS:
1956 case DHO_DOMAIN_NAME_SERVERS:
1957 case DHO_LOG_SERVERS:
1958 case DHO_COOKIE_SERVERS:
1959 case DHO_LPR_SERVERS:
1960 case DHO_IMPRESS_SERVERS:
1961 case DHO_RESOURCE_LOCATION_SERVERS:
1962 case DHO_SWAP_SERVER:
1963 case DHO_BROADCAST_ADDRESS:
1964 case DHO_NIS_SERVERS:
1965 case DHO_NTP_SERVERS:
1966 case DHO_NETBIOS_NAME_SERVERS:
1967 case DHO_NETBIOS_DD_SERVER:
1968 case DHO_FONT_SERVERS:
1969 case DHO_DHCP_SERVER_IDENTIFIER:
1970 if (!ipv4addrs(opbuf)) {
1971 warning("Invalid IP address in option: %s", opbuf);
1972 return (0);
1973 }
1974 return (1);
1975 case DHO_HOST_NAME:
1976 case DHO_DOMAIN_NAME:
1977 case DHO_NIS_DOMAIN:
1978 if (!res_hnok(sbuf, option == DHO_DOMAIN_NAME)) {
1979 warning("Bogus Host Name option %d: %s (%s)", option,
1980 sbuf, opbuf);
1981 l->options[option].len = 0;
1982 free(l->options[option].data);
1983 }
1984 return (1);
1985 case DHO_PAD:
1986 case DHO_TIME_OFFSET:
1987 case DHO_BOOT_SIZE:
1988 case DHO_MERIT_DUMP:
1989 case DHO_ROOT_PATH:
1990 case DHO_EXTENSIONS_PATH:
1991 case DHO_IP_FORWARDING:
1992 case DHO_NON_LOCAL_SOURCE_ROUTING:
1993 case DHO_POLICY_FILTER:
1994 case DHO_MAX_DGRAM_REASSEMBLY:
1995 case DHO_DEFAULT_IP_TTL:
1996 case DHO_PATH_MTU_AGING_TIMEOUT:
1997 case DHO_PATH_MTU_PLATEAU_TABLE:
1998 case DHO_INTERFACE_MTU:
1999 case DHO_ALL_SUBNETS_LOCAL:
2000 case DHO_PERFORM_MASK_DISCOVERY:
2001 case DHO_MASK_SUPPLIER:
2002 case DHO_ROUTER_DISCOVERY:
2003 case DHO_ROUTER_SOLICITATION_ADDRESS:
2004 case DHO_STATIC_ROUTES:
2005 case DHO_TRAILER_ENCAPSULATION:
2006 case DHO_ARP_CACHE_TIMEOUT:
2007 case DHO_IEEE802_3_ENCAPSULATION:
2008 case DHO_DEFAULT_TCP_TTL:
2009 case DHO_TCP_KEEPALIVE_INTERVAL:
2010 case DHO_TCP_KEEPALIVE_GARBAGE:
2011 case DHO_VENDOR_ENCAPSULATED_OPTIONS:
2012 case DHO_NETBIOS_NODE_TYPE:
2013 case DHO_NETBIOS_SCOPE:
2014 case DHO_X_DISPLAY_MANAGER:
2015 case DHO_DHCP_REQUESTED_ADDRESS:
2016 case DHO_DHCP_LEASE_TIME:
2017 case DHO_DHCP_OPTION_OVERLOAD:
2018 case DHO_DHCP_MESSAGE_TYPE:
2019 case DHO_DHCP_PARAMETER_REQUEST_LIST:
2020 case DHO_DHCP_MESSAGE:
2021 case DHO_DHCP_MAX_MESSAGE_SIZE:
2022 case DHO_DHCP_RENEWAL_TIME:
2023 case DHO_DHCP_REBINDING_TIME:
2024 case DHO_DHCP_CLASS_IDENTIFIER:
2025 case DHO_DHCP_CLIENT_IDENTIFIER:
2026 case DHO_DHCP_USER_CLASS_ID:
2027 case DHO_END:
2028 return (1);
2029 default:
2030 warning("unknown dhcp option value 0x%x", option);
2031 return (unknown_ok);
2032 }
2033 }
2034
2035 int
res_hnok(const char * name,bool wsp_ok)2036 res_hnok(const char *name, bool wsp_ok)
2037 {
2038 const char *dn = name;
2039 int pch = '.', ch = *dn++;
2040 bool warn_us = false, warn_sp = false;
2041 const char *warntext = NULL;
2042
2043 while (ch != '\0') {
2044 int nch = *dn++;
2045
2046 if (ch == ' ' || ch == '\t') {
2047 ch = '.'; /* reset to initial state */
2048 if (!warn_sp) {
2049 warntext = "whitespace";
2050 warn_sp = true;
2051 }
2052 } else if (ch == '.') {
2053 ;
2054 } else if (pch == '.' || nch == '.' || nch == '\0') {
2055 if (!isalnum(ch))
2056 return (0);
2057 } else if (!isalnum(ch) && ch != '-' && ch != '_')
2058 return (0);
2059 else if (ch == '_' && !warn_us) {
2060 warn_us = true;
2061 warntext = "an underscore";
2062 }
2063 if (warntext) {
2064 warning("warning: hostname %s contains %s "
2065 "which violates RFC 952", name, warntext);
2066 warntext = NULL;
2067 }
2068 pch = ch, ch = nch;
2069 }
2070 return (1);
2071 }
2072
2073 /* Does buf consist only of dotted decimal ipv4 addrs?
2074 * return how many if so,
2075 * otherwise, return 0
2076 */
2077 int
ipv4addrs(char * buf)2078 ipv4addrs(char * buf)
2079 {
2080 struct in_addr jnk;
2081 int count = 0;
2082
2083 while (inet_aton(buf, &jnk) == 1){
2084 count++;
2085 while (*buf == '.' || isdigit(*buf))
2086 buf++;
2087 if (*buf == '\0')
2088 return (count);
2089 while (*buf == ' ')
2090 buf++;
2091 }
2092 return (0);
2093 }
2094
2095 char *
option_as_string(unsigned int code,unsigned char * data,int len)2096 option_as_string(unsigned int code, unsigned char *data, int len)
2097 {
2098 static char optbuf[32768]; /* XXX */
2099 char *op = optbuf;
2100 int opleft = sizeof(optbuf);
2101 unsigned char *dp = data;
2102
2103 if (code > 255)
2104 error("option_as_string: bad code %d", code);
2105
2106 for (; dp < data + len; dp++) {
2107 if (!isascii(*dp) || !isprint(*dp)) {
2108 if (dp + 1 != data + len || *dp != 0) {
2109 snprintf(op, opleft, "\\%03o", *dp);
2110 op += 4;
2111 opleft -= 4;
2112 }
2113 } else if (*dp == '"' || *dp == '\'' || *dp == '$' ||
2114 *dp == '`' || *dp == '\\') {
2115 *op++ = '\\';
2116 *op++ = *dp;
2117 opleft -= 2;
2118 } else {
2119 *op++ = *dp;
2120 opleft--;
2121 }
2122 }
2123 if (opleft < 1)
2124 goto toobig;
2125 *op = 0;
2126 return optbuf;
2127 toobig:
2128 warning("dhcp option too large");
2129 return "<error>";
2130 }
2131
2132 int
fork_privchld(int fd,int fd2)2133 fork_privchld(int fd, int fd2)
2134 {
2135 struct pollfd pfd[1];
2136 int nfds;
2137
2138 switch (fork()) {
2139 case -1:
2140 error("cannot fork");
2141 break;
2142 case 0:
2143 break;
2144 default:
2145 return (0);
2146 }
2147
2148 if (chdir("/") == -1)
2149 error("chdir(\"/\")");
2150
2151 setproctitle("%s [priv]", ifi->name);
2152
2153 dup2(nullfd, STDIN_FILENO);
2154 dup2(nullfd, STDOUT_FILENO);
2155 dup2(nullfd, STDERR_FILENO);
2156 close(nullfd);
2157 close(fd2);
2158
2159 for (;;) {
2160 pfd[0].fd = fd;
2161 pfd[0].events = POLLIN;
2162 if ((nfds = poll(pfd, 1, INFTIM)) == -1)
2163 if (errno != EINTR)
2164 error("poll error");
2165
2166 if (nfds == 0 || !(pfd[0].revents & POLLIN))
2167 continue;
2168
2169 dispatch_imsg(fd);
2170 }
2171 }
2172