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loader: update elf module code from FreeBSD
[dragonfly.git] / sbin / dhclient / dhclient.c
blob1d7882971e9dbced8a37599edb2c97c19d2411c5
1 /* $OpenBSD: dhclient.c,v 1.118 2008/05/09 05:19:14 reyk Exp $ */
2 /* $DragonFly: src/sbin/dhclient/dhclient.c,v 1.2 2008/09/10 10:01:18 matthias Exp $ */
3
4 /*
5 * Copyright 2004 Henning Brauer <henning@openbsd.org>
6 * Copyright (c) 1995, 1996, 1997, 1998, 1999
7 * The Internet Software Consortium. All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of The Internet Software Consortium nor the names
19 * of its contributors may be used to endorse or promote products derived
20 * from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
23 * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
24 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
25 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
26 * DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
27 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
29 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
30 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
31 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
32 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
33 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * This software has been written for the Internet Software Consortium
37 * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
38 * Enterprises. To learn more about the Internet Software Consortium,
39 * see ``http://www.vix.com/isc''. To learn more about Vixie
40 * Enterprises, see ``http://www.vix.com''.
41 *
42 * This client was substantially modified and enhanced by Elliot Poger
43 * for use on Linux while he was working on the MosquitoNet project at
44 * Stanford.
45 *
46 * The current version owes much to Elliot's Linux enhancements, but
47 * was substantially reorganized and partially rewritten by Ted Lemon
48 * so as to use the same networking framework that the Internet Software
49 * Consortium DHCP server uses. Much system-specific configuration code
50 * was moved into a shell script so that as support for more operating
51 * systems is added, it will not be necessary to port and maintain
52 * system-specific configuration code to these operating systems - instead,
53 * the shell script can invoke the native tools to accomplish the same
54 * purpose.
55 */
56
57 #include <ctype.h>
58 #include <poll.h>
59 #include <pwd.h>
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
67
68 time_t cur_time;
69
70 char *path_dhclient_conf = _PATH_DHCLIENT_CONF;
71 char *path_dhclient_db = NULL;
72
73 int log_perror = 1;
74 int privfd;
75 int nullfd = -1;
76 int no_daemon;
77 int unknown_ok = 1;
78 int routefd = -1;
79
80 struct iaddr iaddr_broadcast = { 4, { 255, 255, 255, 255 } };
81 struct in_addr inaddr_any;
82 struct sockaddr_in sockaddr_broadcast;
83
84 struct interface_info *ifi;
85 struct client_state *client;
86 struct client_config *config;
87
88 int findproto(char *, int);
89 struct sockaddr *get_ifa(char *, int);
90 void usage(void);
91 int check_option(struct client_lease *l, int option);
92 int ipv4addrs(char * buf);
93 int res_hnok(const char *dn);
94 char *option_as_string(unsigned int code, unsigned char *data, int len);
95 int fork_privchld(int, int);
96
97 #define ROUNDUP(a) \
98 ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
99 #define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))
100
101 time_t scripttime;
102 static FILE *leaseFile;
103
104 int
105 findproto(char *cp, int n)
106 {
107 struct sockaddr *sa;
108 int i;
109
110 if (n == 0)
111 return -1;
112 for (i = 1; i; i <<= 1) {
113 if (i & n) {
114 sa = (struct sockaddr *)cp;
115 switch (i) {
116 case RTA_IFA:
117 case RTA_DST:
118 case RTA_GATEWAY:
119 case RTA_NETMASK:
120 if (sa->sa_family == AF_INET)
121 return AF_INET;
122 if (sa->sa_family == AF_INET6)
123 return AF_INET6;
124 break;
125 case RTA_IFP:
126 break;
127 }
128 ADVANCE(cp, sa);
129 }
130 }
131 return (-1);
132 }
133
134 struct sockaddr *
135 get_ifa(char *cp, int n)
136 {
137 struct sockaddr *sa;
138 int i;
139
140 if (n == 0)
141 return (NULL);
142 for (i = 1; i; i <<= 1)
143 if (i & n) {
144 sa = (struct sockaddr *)cp;
145 if (i == RTA_IFA)
146 return (sa);
147 ADVANCE(cp, sa);
148 }
149
150 return (NULL);
151 }
152 struct iaddr defaddr = { .len = 4 }; /* NULL is for silence warnings */
153
154 /* ARGSUSED */
155 void
156 routehandler(void)
157 {
158 int linkstat;
159 char msg[2048];
160 struct rt_msghdr *rtm;
161 struct if_msghdr *ifm;
162 struct ifa_msghdr *ifam;
163 struct if_announcemsghdr *ifan;
164 struct client_lease *l;
165 time_t t = time(NULL);
166 struct sockaddr *sa;
167 struct iaddr a;
168 ssize_t n;
169
170 do {
171 n = read(routefd, &msg, sizeof(msg));
172 } while (n == -1 && errno == EINTR);
173
174 rtm = (struct rt_msghdr *)msg;
175 if (n < sizeof(rtm->rtm_msglen) || n < rtm->rtm_msglen ||
176 rtm->rtm_version != RTM_VERSION)
177 return;
178
179 switch (rtm->rtm_type) {
180 case RTM_NEWADDR:
181 ifam = (struct ifa_msghdr *)rtm;
182 if (ifam->ifam_index != ifi->index)
183 break;
184 if (findproto((char *)(ifam + 1), ifam->ifam_addrs) != AF_INET)
185 break;
186 sa = get_ifa((char *)(ifam + 1), ifam->ifam_addrs);
187 if (sa == NULL)
188 goto die;
189
190 if ((a.len = sizeof(struct in_addr)) > sizeof(a.iabuf))
191 error("king bula sez: len mismatch");
192 memcpy(a.iabuf, &((struct sockaddr_in *)sa)->sin_addr, a.len);
193 if (addr_eq(a, defaddr))
194 break;
195
196 for (l = client->active; l != NULL; l = l->next)
197 if (addr_eq(a, l->address))
198 break;
199
200 if (l != NULL || (client->alias &&
201 addr_eq(a, client->alias->address)))
202 /* new addr is the one we set */
203 break;
204
205 goto die;
206 case RTM_DELADDR:
207 ifam = (struct ifa_msghdr *)rtm;
208 if (ifam->ifam_index != ifi->index)
209 break;
210 if (findproto((char *)(ifam + 1), ifam->ifam_addrs) != AF_INET)
211 break;
212 if (scripttime == 0 || t < scripttime + 10)
213 break;
214 goto die;
215 case RTM_IFINFO:
216 ifm = (struct if_msghdr *)rtm;
217 if (ifm->ifm_index != ifi->index)
218 break;
219 if ((rtm->rtm_flags & RTF_UP) == 0)
220 goto die;
221
222 linkstat =
223 LINK_STATE_IS_UP(ifm->ifm_data.ifi_link_state) ? 1 : 0;
224 if (linkstat != ifi->linkstat) {
225 debug("link state %s -> %s",
226 ifi->linkstat ? "up" : "down",
227 linkstat ? "up" : "down");
228 ifi->linkstat = interface_link_status(ifi->name);
229 if (ifi->linkstat) {
230 client->state = S_INIT;
231 state_reboot();
232 }
233 }
234 break;
235 case RTM_IFANNOUNCE:
236 ifan = (struct if_announcemsghdr *)rtm;
237 if (ifan->ifan_what == IFAN_DEPARTURE &&
238 ifan->ifan_index == ifi->index)
239 goto die;
240 break;
241 default:
242 break;
243 }
244 return;
245
246 die:
247 script_init("FAIL", NULL);
248 if (client->alias)
249 script_write_params("alias_", client->alias);
250 script_go();
251 exit(1);
252 }
253
254 int
255 main(int argc, char *argv[])
256 {
257 int ch, fd, quiet = 0, i = 0, pipe_fd[2];
258 struct passwd *pw;
259
260 /* Initially, log errors to stderr as well as to syslogd. */
261 openlog(getprogname(), LOG_PID | LOG_NDELAY, DHCPD_LOG_FACILITY);
262 setlogmask(LOG_UPTO(LOG_INFO));
263
264 while ((ch = getopt(argc, argv, "c:dl:qu")) != -1)
265 switch (ch) {
266 case 'c':
267 path_dhclient_conf = optarg;
268 break;
269 case 'd':
270 no_daemon = 1;
271 break;
272 case 'l':
273 path_dhclient_db = optarg;
274 break;
275 case 'q':
276 quiet = 1;
277 break;
278 case 'u':
279 unknown_ok = 0;
280 break;
281 default:
282 usage();
283 }
284
285 argc -= optind;
286 argv += optind;
287
288 if (argc != 1)
289 usage();
290
291 ifi = calloc(1, sizeof(*ifi));
292 if (ifi == NULL)
293 error("ifi calloc");
294 client = calloc(1, sizeof(*client));
295 if (client == NULL)
296 error("client calloc");
297 config = calloc(1, sizeof(*config));
298 if (config == NULL)
299 error("config calloc");
300
301 if (strlcpy(ifi->name, argv[0], IFNAMSIZ) >= IFNAMSIZ)
302 error("Interface name too long");
303 if (path_dhclient_db == NULL && asprintf(&path_dhclient_db, "%s.%s",
304 _PATH_DHCLIENT_DB, ifi->name) == -1)
305 error("asprintf");
306
307 if (quiet)
308 log_perror = 0;
309
310 tzset();
311 time(&cur_time);
312
313 memset(&sockaddr_broadcast, 0, sizeof(sockaddr_broadcast));
314 sockaddr_broadcast.sin_family = AF_INET;
315 sockaddr_broadcast.sin_port = htons(REMOTE_PORT);
316 sockaddr_broadcast.sin_addr.s_addr = INADDR_BROADCAST;
317 sockaddr_broadcast.sin_len = sizeof(sockaddr_broadcast);
318 inaddr_any.s_addr = INADDR_ANY;
319
320 read_client_conf();
321
322 if (interface_status(ifi->name) == 0) {
323 interface_link_forceup(ifi->name);
324 /* Give it up to 4 seconds of silent grace to find link */
325 i = -4;
326 } else
327 i = 0;
328
329 while (!(ifi->linkstat = interface_link_status(ifi->name))) {
330 if (i == 0)
331 fprintf(stderr, "%s: no link ...", ifi->name);
332 else if (i > 0)
333 fprintf(stderr, ".");
334 fflush(stderr);
335 if (++i > config->link_timeout) {
336 fprintf(stderr, " sleeping\n");
337 goto dispatch;
338 }
339 sleep(1);
340 }
341 if (i >= 0)
342 fprintf(stderr, " got link\n");
343
344 dispatch:
345 if ((nullfd = open(_PATH_DEVNULL, O_RDWR, 0)) == -1)
346 error("cannot open %s: %m", _PATH_DEVNULL);
347
348 if ((pw = getpwnam("_dhcp")) == NULL) {
349 warning("no such user: _dhcp, falling back to \"nobody\"");
350 if ((pw = getpwnam("nobody")) == NULL)
351 error("no such user: nobody");
352 }
353
354 if (pipe(pipe_fd) == -1)
355 error("pipe");
356
357 fork_privchld(pipe_fd[0], pipe_fd[1]);
358
359 close(pipe_fd[0]);
360 privfd = pipe_fd[1];
361
362 if ((fd = open(path_dhclient_db, O_RDONLY|O_EXLOCK|O_CREAT, 0)) == -1)
363 error("can't open and lock %s: %m", path_dhclient_db);
364 read_client_leases();
365 if ((leaseFile = fopen(path_dhclient_db, "w")) == NULL)
366 error("can't open %s: %m", path_dhclient_db);
367 rewrite_client_leases();
368 close(fd);
369
370 priv_script_init("PREINIT", NULL);
371 if (client->alias)
372 priv_script_write_params("alias_", client->alias);
373 priv_script_go();
374
375 if ((routefd = socket(PF_ROUTE, SOCK_RAW, 0)) == -1)
376 error("socket(PF_ROUTE, SOCK_RAW): %m");
377
378 /* set up the interface */
379 discover_interface();
380
381 if (chroot(_PATH_VAREMPTY) == -1)
382 error("chroot");
383 if (chdir("/") == -1)
384 error("chdir(\"/\")");
385
386 if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1)
387 error("setresgid");
388 if (setgroups(1, &pw->pw_gid) == -1)
389 error("setgroups");
390 if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1)
391 error("setresuid");
392
393 endpwent();
394
395 setproctitle("%s", ifi->name);
396
397 if (ifi->linkstat) {
398 client->state = S_INIT;
399 state_reboot();
400 } else
401 go_daemon();
402
403 dispatch();
404
405 /* not reached */
406 return (0);
407 }
408
409 void
410 usage(void)
411 {
412 fprintf(stderr, "usage: %s [-dqu] [-c file] [-l file] interface\n",
413 getprogname());
414 exit(1);
415 }
416
417 /*
418 * Individual States:
419 *
420 * Each routine is called from the dhclient_state_machine() in one of
421 * these conditions:
422 * -> entering INIT state
423 * -> recvpacket_flag == 0: timeout in this state
424 * -> otherwise: received a packet in this state
425 *
426 * Return conditions as handled by dhclient_state_machine():
427 * Returns 1, sendpacket_flag = 1: send packet, reset timer.
428 * Returns 1, sendpacket_flag = 0: just reset the timer (wait for a milestone).
429 * Returns 0: finish the nap which was interrupted for no good reason.
430 *
431 * Several per-interface variables are used to keep track of the process:
432 * active_lease: the lease that is being used on the interface
433 * (null pointer if not configured yet).
434 * offered_leases: leases corresponding to DHCPOFFER messages that have
435 * been sent to us by DHCP servers.
436 * acked_leases: leases corresponding to DHCPACK messages that have been
437 * sent to us by DHCP servers.
438 * sendpacket: DHCP packet we're trying to send.
439 * destination: IP address to send sendpacket to
440 * In addition, there are several relevant per-lease variables.
441 * T1_expiry, T2_expiry, lease_expiry: lease milestones
442 * In the active lease, these control the process of renewing the lease;
443 * In leases on the acked_leases list, this simply determines when we
444 * can no longer legitimately use the lease.
445 */
446 void
447 state_reboot(void)
448 {
449 /* If we don't remember an active lease, go straight to INIT. */
450 if (!client->active || client->active->is_bootp) {
451 state_init();
452 return;
453 }
454
455 /* We are in the rebooting state. */
456 client->state = S_REBOOTING;
457
458 /* make_request doesn't initialize xid because it normally comes
459 from the DHCPDISCOVER, but we haven't sent a DHCPDISCOVER,
460 so pick an xid now. */
461 client->xid = arc4random();
462
463 /* Make a DHCPREQUEST packet, and set appropriate per-interface
464 flags. */
465 make_request(client->active);
466 client->destination = iaddr_broadcast;
467 client->first_sending = cur_time;
468 client->interval = config->initial_interval;
469
470 /* Zap the medium list... */
471 client->medium = NULL;
472
473 /* Send out the first DHCPREQUEST packet. */
474 send_request();
475 }
476
477 /*
478 * Called when a lease has completely expired and we've
479 * been unable to renew it.
480 */
481 void
482 state_init(void)
483 {
484 /* Make a DHCPDISCOVER packet, and set appropriate per-interface
485 flags. */
486 make_discover(client->active);
487 client->xid = client->packet.xid;
488 client->destination = iaddr_broadcast;
489 client->state = S_SELECTING;
490 client->first_sending = cur_time;
491 client->interval = config->initial_interval;
492
493 /* Add an immediate timeout to cause the first DHCPDISCOVER packet
494 to go out. */
495 send_discover();
496 }
497
498 /*
499 * state_selecting is called when one or more DHCPOFFER packets
500 * have been received and a configurable period of time has passed.
501 */
502 void
503 state_selecting(void)
504 {
505 struct client_lease *lp, *next, *picked;
506
507 /* Cancel state_selecting and send_discover timeouts, since either
508 one could have got us here. */
509 cancel_timeout(state_selecting);
510 cancel_timeout(send_discover);
511
512 /* We have received one or more DHCPOFFER packets. Currently,
513 the only criterion by which we judge leases is whether or
514 not we get a response when we arp for them. */
515 picked = NULL;
516 for (lp = client->offered_leases; lp; lp = next) {
517 next = lp->next;
518
519 /* Check to see if we got an ARPREPLY for the address
520 in this particular lease. */
521 if (!picked) {
522 script_init("ARPCHECK", lp->medium);
523 script_write_params("check_", lp);
524
525 /* If the ARPCHECK code detects another
526 machine using the offered address, it exits
527 nonzero. We need to send a DHCPDECLINE and
528 toss the lease. */
529 if (script_go()) {
530 make_decline(lp);
531 send_decline();
532 goto freeit;
533 }
534 picked = lp;
535 picked->next = NULL;
536 } else {
537 freeit:
538 free_client_lease(lp);
539 }
540 }
541 client->offered_leases = NULL;
542
543 /* If we just tossed all the leases we were offered, go back
544 to square one. */
545 if (!picked) {
546 client->state = S_INIT;
547 state_init();
548 return;
549 }
550
551 /* If it was a BOOTREPLY, we can just take the address right now. */
552 if (!picked->options[DHO_DHCP_MESSAGE_TYPE].len) {
553 client->new = picked;
554
555 /* Make up some lease expiry times
556 XXX these should be configurable. */
557 client->new->expiry = cur_time + 12000;
558 client->new->renewal += cur_time + 8000;
559 client->new->rebind += cur_time + 10000;
560
561 client->state = S_REQUESTING;
562
563 /* Bind to the address we received. */
564 bind_lease();
565 return;
566 }
567
568 /* Go to the REQUESTING state. */
569 client->destination = iaddr_broadcast;
570 client->state = S_REQUESTING;
571 client->first_sending = cur_time;
572 client->interval = config->initial_interval;
573
574 /* Make a DHCPREQUEST packet from the lease we picked. */
575 make_request(picked);
576 client->xid = client->packet.xid;
577
578 /* Toss the lease we picked - we'll get it back in a DHCPACK. */
579 free_client_lease(picked);
580
581 /* Add an immediate timeout to send the first DHCPREQUEST packet. */
582 send_request();
583 }
584
585 void
586 dhcpack(struct iaddr client_addr, struct option_data *options)
587 {
588 struct client_lease *lease;
589
590 if (client->xid != client->packet.xid)
591 return;
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
599 note("DHCPACK from %s", piaddr(client_addr));
600
601 lease = packet_to_lease(options);
602 if (!lease) {
603 note("packet_to_lease failed.");
604 return;
605 }
606
607 client->new = lease;
608
609 /* Stop resending DHCPREQUEST. */
610 cancel_timeout(send_request);
611
612 /* Figure out the lease time. */
613 if (client->new->options[DHO_DHCP_LEASE_TIME].data)
614 client->new->expiry =
615 getULong(client->new->options[DHO_DHCP_LEASE_TIME].data);
616 else
617 client->new->expiry = DEFAULT_LEASE_TIME;
618 /* A number that looks negative here is really just very large,
619 because the lease expiry offset is unsigned. */
620 if (client->new->expiry < 0)
621 client->new->expiry = TIME_MAX;
622 /* XXX should be fixed by resetting the client state */
623 if (client->new->expiry < 60)
624 client->new->expiry = 60;
625
626 /* Take the server-provided renewal time if there is one;
627 otherwise figure it out according to the spec. */
628 if (client->new->options[DHO_DHCP_RENEWAL_TIME].len)
629 client->new->renewal =
630 getULong(client->new->options[DHO_DHCP_RENEWAL_TIME].data);
631 else
632 client->new->renewal = client->new->expiry / 2;
633
634 /* Same deal with the rebind time. */
635 if (client->new->options[DHO_DHCP_REBINDING_TIME].len)
636 client->new->rebind =
637 getULong(client->new->options[DHO_DHCP_REBINDING_TIME].data);
638 else
639 client->new->rebind = client->new->renewal +
640 client->new->renewal / 2 + client->new->renewal / 4;
641
642 client->new->expiry += cur_time;
643 /* Lease lengths can never be negative. */
644 if (client->new->expiry < cur_time)
645 client->new->expiry = TIME_MAX;
646 client->new->renewal += cur_time;
647 if (client->new->renewal < cur_time)
648 client->new->renewal = TIME_MAX;
649 client->new->rebind += cur_time;
650 if (client->new->rebind < cur_time)
651 client->new->rebind = TIME_MAX;
652
653 bind_lease();
654 }
655
656 void
657 bind_lease(void)
658 {
659 /* Remember the medium. */
660 client->new->medium = client->medium;
661
662 /* Write out the new lease. */
663 write_client_lease(client->new, 0);
664
665 /* Run the client script with the new parameters. */
666 script_init((client->state == S_REQUESTING ? "BOUND" :
667 (client->state == S_RENEWING ? "RENEW" :
668 (client->state == S_REBOOTING ? "REBOOT" : "REBIND"))),
669 client->new->medium);
670 if (client->active && client->state != S_REBOOTING)
671 script_write_params("old_", client->active);
672 script_write_params("new_", client->new);
673 if (client->alias)
674 script_write_params("alias_", client->alias);
675 script_go();
676
677 /* Replace the old active lease with the new one. */
678 if (client->active)
679 free_client_lease(client->active);
680 client->active = client->new;
681 client->new = NULL;
682
683 /* Set up a timeout to start the renewal process. */
684 add_timeout(client->active->renewal, state_bound);
685
686 note("bound to %s -- renewal in %ld seconds.",
687 piaddr(client->active->address),
688 client->active->renewal - cur_time);
689 client->state = S_BOUND;
690 reinitialize_interface();
691 go_daemon();
692 }
693
694 /*
695 * state_bound is called when we've successfully bound to a particular
696 * lease, but the renewal time on that lease has expired. We are
697 * expected to unicast a DHCPREQUEST to the server that gave us our
698 * original lease.
699 */
700 void
701 state_bound(void)
702 {
703 /* T1 has expired. */
704 make_request(client->active);
705 client->xid = client->packet.xid;
706
707 if (client->active->options[DHO_DHCP_SERVER_IDENTIFIER].len == 4) {
708 memcpy(client->destination.iabuf,
709 client->active->options[DHO_DHCP_SERVER_IDENTIFIER].data,
710 4);
711 client->destination.len = 4;
712 } else
713 client->destination = iaddr_broadcast;
714
715 client->first_sending = cur_time;
716 client->interval = config->initial_interval;
717 client->state = S_RENEWING;
718
719 /* Send the first packet immediately. */
720 send_request();
721 }
722
723 void
724 dhcpoffer(struct iaddr client_addr, struct option_data *options)
725 {
726 struct client_lease *lease, *lp;
727 int i;
728 int arp_timeout_needed, stop_selecting;
729 char *name = options[DHO_DHCP_MESSAGE_TYPE].len ? "DHCPOFFER" :
730 "BOOTREPLY";
731
732 if (client->xid != client->packet.xid)
733 return;
734
735 if (client->state != S_SELECTING)
736 return;
737
738 note("%s from %s", name, piaddr(client_addr));
739
740 /* If this lease doesn't supply the minimum required parameters,
741 blow it off. */
742 for (i = 0; config->required_options[i]; i++) {
743 if (!options[config->required_options[i]].len) {
744 note("%s isn't satisfactory.", name);
745 return;
746 }
747 }
748
749 /* If we've already seen this lease, don't record it again. */
750 for (lease = client->offered_leases;
751 lease; lease = lease->next) {
752 if (lease->address.len == sizeof(client->packet.yiaddr) &&
753 !memcmp(lease->address.iabuf,
754 &client->packet.yiaddr, lease->address.len)) {
755 debug("%s already seen.", name);
756 return;
757 }
758 }
759
760 lease = packet_to_lease(options);
761 if (!lease) {
762 note("packet_to_lease failed.");
763 return;
764 }
765
766 /* If this lease was acquired through a BOOTREPLY, record that
767 fact. */
768 if (!options[DHO_DHCP_MESSAGE_TYPE].len)
769 lease->is_bootp = 1;
770
771 /* Record the medium under which this lease was offered. */
772 lease->medium = client->medium;
773
774 /* Send out an ARP Request for the offered IP address. */
775 script_init("ARPSEND", lease->medium);
776 script_write_params("check_", lease);
777 /* If the script can't send an ARP request without waiting,
778 we'll be waiting when we do the ARPCHECK, so don't wait now. */
779 if (script_go())
780 arp_timeout_needed = 0;
781 else
782 arp_timeout_needed = 2;
783
784 /* Figure out when we're supposed to stop selecting. */
785 stop_selecting = client->first_sending + config->select_interval;
786
787 /* If this is the lease we asked for, put it at the head of the
788 list, and don't mess with the arp request timeout. */
789 if (lease->address.len == client->requested_address.len &&
790 !memcmp(lease->address.iabuf,
791 client->requested_address.iabuf,
792 client->requested_address.len)) {
793 lease->next = client->offered_leases;
794 client->offered_leases = lease;
795 } else {
796 /* If we already have an offer, and arping for this
797 offer would take us past the selection timeout,
798 then don't extend the timeout - just hope for the
799 best. */
800 if (client->offered_leases &&
801 (cur_time + arp_timeout_needed) > stop_selecting)
802 arp_timeout_needed = 0;
803
804 /* Put the lease at the end of the list. */
805 lease->next = NULL;
806 if (!client->offered_leases)
807 client->offered_leases = lease;
808 else {
809 for (lp = client->offered_leases; lp->next;
810 lp = lp->next)
811 ; /* nothing */
812 lp->next = lease;
813 }
814 }
815
816 /* If we're supposed to stop selecting before we've had time
817 to wait for the ARPREPLY, add some delay to wait for
818 the ARPREPLY. */
819 if (stop_selecting - cur_time < arp_timeout_needed)
820 stop_selecting = cur_time + arp_timeout_needed;
821
822 /* If the selecting interval has expired, go immediately to
823 state_selecting(). Otherwise, time out into
824 state_selecting at the select interval. */
825 if (stop_selecting <= 0)
826 state_selecting();
827 else {
828 add_timeout(stop_selecting, state_selecting);
829 cancel_timeout(send_discover);
830 }
831 }
832
833 /*
834 * Allocate a client_lease structure and initialize it from the
835 * parameters in the specified packet.
836 */
837 struct client_lease *
838 packet_to_lease(struct option_data *options)
839 {
840 struct client_lease *lease;
841 int i;
842
843 lease = malloc(sizeof(struct client_lease));
844
845 if (!lease) {
846 warning("dhcpoffer: no memory to record lease.");
847 return (NULL);
848 }
849
850 memset(lease, 0, sizeof(*lease));
851
852 /* Copy the lease options. */
853 for (i = 0; i < 256; i++) {
854 if (options[i].len) {
855 lease->options[i] = options[i];
856 options[i].data = NULL;
857 options[i].len = 0;
858 if (!check_option(lease, i)) {
859 warning("Invalid lease option - ignoring offer");
860 free_client_lease(lease);
861 return (NULL);
862 }
863 }
864 }
865
866 lease->address.len = sizeof(client->packet.yiaddr);
867 memcpy(lease->address.iabuf, &client->packet.yiaddr,
868 lease->address.len);
869
870 /* If the server name was filled out, copy it. */
871 if ((!lease->options[DHO_DHCP_OPTION_OVERLOAD].len ||
872 !(lease->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 2)) &&
873 client->packet.sname[0]) {
874 lease->server_name = malloc(DHCP_SNAME_LEN + 1);
875 if (!lease->server_name) {
876 warning("dhcpoffer: no memory for server name.");
877 free_client_lease(lease);
878 return (NULL);
879 }
880 memcpy(lease->server_name, client->packet.sname,
881 DHCP_SNAME_LEN);
882 lease->server_name[DHCP_SNAME_LEN] = '\0';
883 if (!res_hnok(lease->server_name)) {
884 warning("Bogus server name %s", lease->server_name);
885 free(lease->server_name);
886 lease->server_name = NULL;
887 }
888 }
889
890 /* Ditto for the filename. */
891 if ((!lease->options[DHO_DHCP_OPTION_OVERLOAD].len ||
892 !(lease->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 1)) &&
893 client->packet.file[0]) {
894 /* Don't count on the NUL terminator. */
895 lease->filename = malloc(DHCP_FILE_LEN + 1);
896 if (!lease->filename) {
897 warning("dhcpoffer: no memory for filename.");
898 free_client_lease(lease);
899 return (NULL);
900 }
901 memcpy(lease->filename, client->packet.file, DHCP_FILE_LEN);
902 lease->filename[DHCP_FILE_LEN] = '\0';
903 }
904 return lease;
905 }
906
907 void
908 dhcpnak(struct iaddr client_addr, struct option_data *options)
909 {
910 if (client->xid != client->packet.xid)
911 return;
912
913 if (client->state != S_REBOOTING &&
914 client->state != S_REQUESTING &&
915 client->state != S_RENEWING &&
916 client->state != S_REBINDING)
917 return;
918
919 note("DHCPNAK from %s", piaddr(client_addr));
920
921 if (!client->active) {
922 note("DHCPNAK with no active lease.");
923 return;
924 }
925
926 free_client_lease(client->active);
927 client->active = NULL;
928
929 /* Stop sending DHCPREQUEST packets... */
930 cancel_timeout(send_request);
931
932 client->state = S_INIT;
933 state_init();
934 }
935
936 /*
937 * Send out a DHCPDISCOVER packet, and set a timeout to send out another
938 * one after the right interval has expired. If we don't get an offer by
939 * the time we reach the panic interval, call the panic function.
940 */
941 void
942 send_discover(void)
943 {
944 int interval, increase = 1;
945
946 /* Figure out how long it's been since we started transmitting. */
947 interval = cur_time - client->first_sending;
948
949 /* If we're past the panic timeout, call the script and tell it
950 we haven't found anything for this interface yet. */
951 if (interval > config->timeout) {
952 state_panic();
953 return;
954 }
955
956 /* If we're selecting media, try the whole list before doing
957 the exponential backoff, but if we've already received an
958 offer, stop looping, because we obviously have it right. */
959 if (!client->offered_leases && config->media) {
960 int fail = 0;
961 again:
962 if (client->medium) {
963 client->medium = client->medium->next;
964 increase = 0;
965 }
966 if (!client->medium) {
967 if (fail)
968 error("No valid media types for %s!", ifi->name);
969 client->medium = config->media;
970 increase = 1;
971 }
972
973 note("Trying medium \"%s\" %d", client->medium->string,
974 increase);
975 script_init("MEDIUM", client->medium);
976 if (script_go())
977 goto again;
978 }
979
980 /*
981 * If we're supposed to increase the interval, do so. If it's
982 * currently zero (i.e., we haven't sent any packets yet), set
983 * it to initial_interval; otherwise, add to it a random
984 * number between zero and two times itself. On average, this
985 * means that it will double with every transmission.
986 */
987 if (increase) {
988 if (!client->interval)
989 client->interval = config->initial_interval;
990 else {
991 client->interval += (arc4random() >> 2) %
992 (2 * client->interval);
993 }
994
995 /* Don't backoff past cutoff. */
996 if (client->interval > config->backoff_cutoff)
997 client->interval = ((config->backoff_cutoff / 2)
998 + ((arc4random() >> 2) %
999 config->backoff_cutoff));
1000 } else if (!client->interval)
1001 client->interval = config->initial_interval;
1002
1003 /* If the backoff would take us to the panic timeout, just use that
1004 as the interval. */
1005 if (cur_time + client->interval >
1006 client->first_sending + config->timeout)
1007 client->interval = (client->first_sending +
1008 config->timeout) - cur_time + 1;
1009
1010 /* Record the number of seconds since we started sending. */
1011 if (interval < 65536)
1012 client->packet.secs = htons(interval);
1013 else
1014 client->packet.secs = htons(65535);
1015 client->secs = client->packet.secs;
1016
1017 note("DHCPDISCOVER on %s to %s port %d interval %ld",
1018 ifi->name, inet_ntoa(sockaddr_broadcast.sin_addr),
1019 ntohs(sockaddr_broadcast.sin_port), client->interval);
1020
1021 /* Send out a packet. */
1022 send_packet(inaddr_any, &sockaddr_broadcast, NULL);
1023
1024 add_timeout(cur_time + client->interval, send_discover);
1025 }
1026
1027 /*
1028 * state_panic gets called if we haven't received any offers in a preset
1029 * amount of time. When this happens, we try to use existing leases
1030 * that haven't yet expired, and failing that, we call the client script
1031 * and hope it can do something.
1032 */
1033 void
1034 state_panic(void)
1035 {
1036 struct client_lease *loop = client->active;
1037 struct client_lease *lp;
1038
1039 note("No DHCPOFFERS received.");
1040
1041 /* We may not have an active lease, but we may have some
1042 predefined leases that we can try. */
1043 if (!client->active && client->leases)
1044 goto activate_next;
1045
1046 /* Run through the list of leases and see if one can be used. */
1047 while (client->active) {
1048 if (client->active->expiry > cur_time) {
1049 note("Trying recorded lease %s",
1050 piaddr(client->active->address));
1051 /* Run the client script with the existing
1052 parameters. */
1053 script_init("TIMEOUT",
1054 client->active->medium);
1055 script_write_params("new_", client->active);
1056 if (client->alias)
1057 script_write_params("alias_",
1058 client->alias);
1059
1060 /* If the old lease is still good and doesn't
1061 yet need renewal, go into BOUND state and
1062 timeout at the renewal time. */
1063 if (!script_go()) {
1064 if (cur_time <
1065 client->active->renewal) {
1066 client->state = S_BOUND;
1067 note("bound: renewal in %ld seconds.",
1068 client->active->renewal -
1069 cur_time);
1070 add_timeout(client->active->renewal,
1071 state_bound);
1072 } else {
1073 client->state = S_BOUND;
1074 note("bound: immediate renewal.");
1075 state_bound();
1076 }
1077 reinitialize_interface();
1078 go_daemon();
1079 return;
1080 }
1081 }
1082
1083 /* If there are no other leases, give up. */
1084 if (!client->leases) {
1085 client->leases = client->active;
1086 client->active = NULL;
1087 break;
1088 }
1089
1090 activate_next:
1091 /* Otherwise, put the active lease at the end of the
1092 lease list, and try another lease.. */
1093 for (lp = client->leases; lp->next; lp = lp->next)
1094 ;
1095 lp->next = client->active;
1096 if (lp->next)
1097 lp->next->next = NULL;
1098 client->active = client->leases;
1099 client->leases = client->leases->next;
1100
1101 /* If we already tried this lease, we've exhausted the
1102 set of leases, so we might as well give up for
1103 now. */
1104 if (client->active == loop)
1105 break;
1106 else if (!loop)
1107 loop = client->active;
1108 }
1109
1110 /* No leases were available, or what was available didn't work, so
1111 tell the shell script that we failed to allocate an address,
1112 and try again later. */
1113 note("No working leases in persistent database - sleeping.");
1114 script_init("FAIL", NULL);
1115 if (client->alias)
1116 script_write_params("alias_", client->alias);
1117 script_go();
1118 client->state = S_INIT;
1119 add_timeout(cur_time + config->retry_interval, state_init);
1120 go_daemon();
1121 }
1122
1123 void
1124 send_request(void)
1125 {
1126 struct sockaddr_in destination;
1127 struct in_addr from;
1128 int interval;
1129
1130 /* Figure out how long it's been since we started transmitting. */
1131 interval = cur_time - client->first_sending;
1132
1133 /* If we're in the INIT-REBOOT or REQUESTING state and we're
1134 past the reboot timeout, go to INIT and see if we can
1135 DISCOVER an address... */
1136 /* XXX In the INIT-REBOOT state, if we don't get an ACK, it
1137 means either that we're on a network with no DHCP server,
1138 or that our server is down. In the latter case, assuming
1139 that there is a backup DHCP server, DHCPDISCOVER will get
1140 us a new address, but we could also have successfully
1141 reused our old address. In the former case, we're hosed
1142 anyway. This is not a win-prone situation. */
1143 if ((client->state == S_REBOOTING ||
1144 client->state == S_REQUESTING) &&
1145 interval > config->reboot_timeout) {
1146 cancel:
1147 client->state = S_INIT;
1148 cancel_timeout(send_request);
1149 state_init();
1150 return;
1151 }
1152
1153 /* If we're in the reboot state, make sure the media is set up
1154 correctly. */
1155 if (client->state == S_REBOOTING &&
1156 !client->medium &&
1157 client->active->medium) {
1158 script_init("MEDIUM", client->active->medium);
1159
1160 /* If the medium we chose won't fly, go to INIT state. */
1161 if (script_go())
1162 goto cancel;
1163
1164 /* Record the medium. */
1165 client->medium = client->active->medium;
1166 }
1167
1168 /* If the lease has expired, relinquish the address and go back
1169 to the INIT state. */
1170 if (client->state != S_REQUESTING &&
1171 cur_time > client->active->expiry) {
1172 /* Run the client script with the new parameters. */
1173 script_init("EXPIRE", NULL);
1174 script_write_params("old_", client->active);
1175 if (client->alias)
1176 script_write_params("alias_", client->alias);
1177 script_go();
1178
1179 /* Now do a preinit on the interface so that we can
1180 discover a new address. */
1181 script_init("PREINIT", NULL);
1182 if (client->alias)
1183 script_write_params("alias_", client->alias);
1184 script_go();
1185
1186 client->state = S_INIT;
1187 state_init();
1188 return;
1189 }
1190
1191 /* Do the exponential backoff... */
1192 if (!client->interval)
1193 client->interval = config->initial_interval;
1194 else
1195 client->interval += ((arc4random() >> 2) %
1196 (2 * client->interval));
1197
1198 /* Don't backoff past cutoff. */
1199 if (client->interval > config->backoff_cutoff)
1200 client->interval = ((config->backoff_cutoff / 2) +
1201 ((arc4random() >> 2) % client->interval));
1202
1203 /* If the backoff would take us to the expiry time, just set the
1204 timeout to the expiry time. */
1205 if (client->state != S_REQUESTING && cur_time + client->interval >
1206 client->active->expiry)
1207 client->interval = client->active->expiry - cur_time + 1;
1208
1209 /* If the lease T2 time has elapsed, or if we're not yet bound,
1210 broadcast the DHCPREQUEST rather than unicasting. */
1211 memset(&destination, 0, sizeof(destination));
1212 if (client->state == S_REQUESTING ||
1213 client->state == S_REBOOTING ||
1214 cur_time > client->active->rebind)
1215 destination.sin_addr.s_addr = INADDR_BROADCAST;
1216 else
1217 memcpy(&destination.sin_addr.s_addr, client->destination.iabuf,
1218 sizeof(destination.sin_addr.s_addr));
1219 destination.sin_port = htons(REMOTE_PORT);
1220 destination.sin_family = AF_INET;
1221 destination.sin_len = sizeof(destination);
1222
1223 if (client->state != S_REQUESTING)
1224 memcpy(&from, client->active->address.iabuf, sizeof(from));
1225 else
1226 from.s_addr = INADDR_ANY;
1227
1228 /* Record the number of seconds since we started sending. */
1229 if (client->state == S_REQUESTING)
1230 client->packet.secs = client->secs;
1231 else {
1232 if (interval < 65536)
1233 client->packet.secs = htons(interval);
1234 else
1235 client->packet.secs = htons(65535);
1236 }
1237
1238 note("DHCPREQUEST on %s to %s port %d", ifi->name,
1239 inet_ntoa(destination.sin_addr), ntohs(destination.sin_port));
1240
1241 /* Send out a packet. */
1242 send_packet(from, &destination, NULL);
1243
1244 add_timeout(cur_time + client->interval, send_request);
1245 }
1246
1247 void
1248 send_decline(void)
1249 {
1250 note("DHCPDECLINE on %s to %s port %d", ifi->name,
1251 inet_ntoa(sockaddr_broadcast.sin_addr),
1252 ntohs(sockaddr_broadcast.sin_port));
1253
1254 /* Send out a packet. */
1255 send_packet(inaddr_any, &sockaddr_broadcast, NULL);
1256 }
1257
1258 void
1259 make_discover(struct client_lease *lease)
1260 {
1261 unsigned char discover = DHCPDISCOVER;
1262 struct option_data options[256];
1263 int i;
1264
1265 memset(options, 0, sizeof(options));
1266 memset(&client->packet, 0, sizeof(client->packet));
1267
1268 /* Set DHCP_MESSAGE_TYPE to DHCPDISCOVER */
1269 i = DHO_DHCP_MESSAGE_TYPE;
1270 options[i].data = &discover;
1271 options[i].len = sizeof(discover);
1272
1273 /* Request the options we want */
1274 i = DHO_DHCP_PARAMETER_REQUEST_LIST;
1275 options[i].data = config->requested_options;
1276 options[i].len = config->requested_option_count;
1277
1278 /* If we had an address, try to get it again. */
1279 if (lease) {
1280 client->requested_address = lease->address;
1281 i = DHO_DHCP_REQUESTED_ADDRESS;
1282 options[i].data = lease->address.iabuf;
1283 options[i].len = lease->address.len;
1284 } else
1285 client->requested_address.len = 0;
1286
1287 /* Send any options requested in the config file. */
1288 for (i = 0; i < 256; i++)
1289 if (!options[i].data &&
1290 config->send_options[i].data) {
1291 options[i].data = config->send_options[i].data;
1292 options[i].len = config->send_options[i].len;
1293 }
1294
1295 /* Set up the option buffer to fit in a minimal UDP packet. */
1296 i = cons_options(client->packet.options, 576 - DHCP_FIXED_LEN,
1297 options);
1298 if (i == -1 || client->packet.options[i] != DHO_END)
1299 error("options do not fit in DHCPDISCOVER packet.");
1300 client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1301 if (client->packet_length < BOOTP_MIN_LEN)
1302 client->packet_length = BOOTP_MIN_LEN;
1303
1304 client->packet.op = BOOTREQUEST;
1305 client->packet.htype = ifi->hw_address.htype;
1306 client->packet.hlen = ifi->hw_address.hlen;
1307 client->packet.hops = 0;
1308 client->packet.xid = arc4random();
1309 client->packet.secs = 0; /* filled in by send_discover. */
1310 client->packet.flags = 0;
1311
1312 memset(&client->packet.ciaddr, 0, sizeof(client->packet.ciaddr));
1313 memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1314 memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1315 memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1316 memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1317 ifi->hw_address.hlen);
1318 }
1319
1320 void
1321 make_request(struct client_lease * lease)
1322 {
1323 unsigned char request = DHCPREQUEST;
1324 struct option_data options[256];
1325 int i;
1326
1327 memset(options, 0, sizeof(options));
1328 memset(&client->packet, 0, sizeof(client->packet));
1329
1330 /* Set DHCP_MESSAGE_TYPE to DHCPREQUEST */
1331 i = DHO_DHCP_MESSAGE_TYPE;
1332 options[i].data = &request;
1333 options[i].len = sizeof(request);
1334
1335 /* Request the options we want */
1336 i = DHO_DHCP_PARAMETER_REQUEST_LIST;
1337 options[i].data = config->requested_options;
1338 options[i].len = config->requested_option_count;
1339
1340 /* If we are requesting an address that hasn't yet been assigned
1341 to us, use the DHCP Requested Address option. */
1342 if (client->state == S_REQUESTING) {
1343 /* Send back the server identifier... */
1344 i = DHO_DHCP_SERVER_IDENTIFIER;
1345 options[i].data = lease->options[i].data;
1346 options[i].len = lease->options[i].len;
1347 }
1348 if (client->state == S_REQUESTING ||
1349 client->state == S_REBOOTING) {
1350 client->requested_address = lease->address;
1351 i = DHO_DHCP_REQUESTED_ADDRESS;
1352 options[i].data = lease->address.iabuf;
1353 options[i].len = lease->address.len;
1354 } else
1355 client->requested_address.len = 0;
1356
1357 /* Send any options requested in the config file. */
1358 for (i = 0; i < 256; i++)
1359 if (!options[i].data && config->send_options[i].data) {
1360 options[i].data = config->send_options[i].data;
1361 options[i].len = config->send_options[i].len;
1362 }
1363
1364 /* Set up the option buffer to fit in a minimal UDP packet. */
1365 i = cons_options(client->packet.options, 576 - DHCP_FIXED_LEN,
1366 options);
1367 if (i == -1 || client->packet.options[i] != DHO_END)
1368 error("options do not fit in DHCPREQUEST packet.");
1369 client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1370 if (client->packet_length < BOOTP_MIN_LEN)
1371 client->packet_length = BOOTP_MIN_LEN;
1372
1373 client->packet.op = BOOTREQUEST;
1374 client->packet.htype = ifi->hw_address.htype;
1375 client->packet.hlen = ifi->hw_address.hlen;
1376 client->packet.hops = 0;
1377 client->packet.xid = client->xid;
1378 client->packet.secs = 0; /* Filled in by send_request. */
1379 client->packet.flags = 0;
1380
1381 /* If we own the address we're requesting, put it in ciaddr;
1382 otherwise set ciaddr to zero. */
1383 if (client->state == S_BOUND ||
1384 client->state == S_RENEWING ||
1385 client->state == S_REBINDING) {
1386 memcpy(&client->packet.ciaddr,
1387 lease->address.iabuf, lease->address.len);
1388 } else {
1389 memset(&client->packet.ciaddr, 0,
1390 sizeof(client->packet.ciaddr));
1391 }
1392
1393 memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1394 memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1395 memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1396 memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1397 ifi->hw_address.hlen);
1398 }
1399
1400 void
1401 make_decline(struct client_lease *lease)
1402 {
1403 struct option_data options[256];
1404 unsigned char decline = DHCPDECLINE;
1405 int i;
1406
1407 memset(options, 0, sizeof(options));
1408 memset(&client->packet, 0, sizeof(client->packet));
1409
1410 /* Set DHCP_MESSAGE_TYPE to DHCPDECLINE */
1411 i = DHO_DHCP_MESSAGE_TYPE;
1412 options[i].data = &decline;
1413 options[i].len = sizeof(decline);
1414
1415 /* Send back the server identifier... */
1416 i = DHO_DHCP_SERVER_IDENTIFIER;
1417 options[i].data = lease->options[i].data;
1418 options[i].len = lease->options[i].len;
1419
1420 /* Send back the address we're declining. */
1421 i = DHO_DHCP_REQUESTED_ADDRESS;
1422 options[i].data = lease->address.iabuf;
1423 options[i].len = lease->address.len;
1424
1425 /* Send the uid if the user supplied one. */
1426 i = DHO_DHCP_CLIENT_IDENTIFIER;
1427 if (config->send_options[i].len) {
1428 options[i].data = config->send_options[i].data;
1429 options[i].len = config->send_options[i].len;
1430 }
1431
1432 /* Set up the option buffer to fit in a minimal UDP packet. */
1433 i = cons_options(client->packet.options, 576 - DHCP_FIXED_LEN,
1434 options);
1435 if (i == -1 || client->packet.options[i] != DHO_END)
1436 error("options do not fit in DHCPDECLINE packet.");
1437 client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1438 if (client->packet_length < BOOTP_MIN_LEN)
1439 client->packet_length = BOOTP_MIN_LEN;
1440
1441 client->packet.op = BOOTREQUEST;
1442 client->packet.htype = ifi->hw_address.htype;
1443 client->packet.hlen = ifi->hw_address.hlen;
1444 client->packet.hops = 0;
1445 client->packet.xid = client->xid;
1446 client->packet.secs = 0; /* Filled in by send_request. */
1447 client->packet.flags = 0;
1448
1449 /* ciaddr must always be zero. */
1450 memset(&client->packet.ciaddr, 0, sizeof(client->packet.ciaddr));
1451 memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1452 memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1453 memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1454 memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1455 ifi->hw_address.hlen);
1456 }
1457
1458 void
1459 free_client_lease(struct client_lease *lease)
1460 {
1461 int i;
1462
1463 if (lease->server_name)
1464 free(lease->server_name);
1465 if (lease->filename)
1466 free(lease->filename);
1467 for (i = 0; i < 256; i++) {
1468 if (lease->options[i].len)
1469 free(lease->options[i].data);
1470 }
1471 free(lease);
1472 }
1473
1474 void
1475 rewrite_client_leases(void)
1476 {
1477 struct client_lease *lp;
1478
1479 if (!leaseFile) /* XXX */
1480 error("lease file not open");
1481
1482 fflush(leaseFile);
1483 rewind(leaseFile);
1484
1485 for (lp = client->leases; lp; lp = lp->next)
1486 write_client_lease(lp, 1);
1487 if (client->active)
1488 write_client_lease(client->active, 1);
1489
1490 fflush(leaseFile);
1491 ftruncate(fileno(leaseFile), ftello(leaseFile));
1492 fsync(fileno(leaseFile));
1493 }
1494
1495 void
1496 write_client_lease(struct client_lease *lease, int rewrite)
1497 {
1498 static int leases_written;
1499 struct tm *t;
1500 int i;
1501
1502 if (!rewrite) {
1503 if (leases_written++ > 20) {
1504 rewrite_client_leases();
1505 leases_written = 0;
1506 }
1507 }
1508
1509 /* If the lease came from the config file, we don't need to stash
1510 a copy in the lease database. */
1511 if (lease->is_static)
1512 return;
1513
1514 if (!leaseFile) /* XXX */
1515 error("lease file not open");
1516
1517 fprintf(leaseFile, "lease {\n");
1518 if (lease->is_bootp)
1519 fprintf(leaseFile, " bootp;\n");
1520 fprintf(leaseFile, " interface \"%s\";\n", ifi->name);
1521 fprintf(leaseFile, " fixed-address %s;\n", piaddr(lease->address));
1522 if (lease->filename)
1523 fprintf(leaseFile, " filename \"%s\";\n", lease->filename);
1524 if (lease->server_name)
1525 fprintf(leaseFile, " server-name \"%s\";\n",
1526 lease->server_name);
1527 if (lease->medium)
1528 fprintf(leaseFile, " medium \"%s\";\n", lease->medium->string);
1529 for (i = 0; i < 256; i++)
1530 if (lease->options[i].len)
1531 fprintf(leaseFile, " option %s %s;\n",
1532 dhcp_options[i].name,
1533 pretty_print_option(i, lease->options[i].data,
1534 lease->options[i].len, 1, 1));
1535
1536 t = gmtime(&lease->renewal);
1537 fprintf(leaseFile, " renew %d %d/%d/%d %02d:%02d:%02d;\n",
1538 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1539 t->tm_hour, t->tm_min, t->tm_sec);
1540 t = gmtime(&lease->rebind);
1541 fprintf(leaseFile, " rebind %d %d/%d/%d %02d:%02d:%02d;\n",
1542 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1543 t->tm_hour, t->tm_min, t->tm_sec);
1544 t = gmtime(&lease->expiry);
1545 fprintf(leaseFile, " expire %d %d/%d/%d %02d:%02d:%02d;\n",
1546 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1547 t->tm_hour, t->tm_min, t->tm_sec);
1548 fprintf(leaseFile, "}\n");
1549 fflush(leaseFile);
1550 }
1551
1552 void
1553 script_init(char *reason, struct string_list *medium)
1554 {
1555 size_t len, mediumlen = 0;
1556 struct imsg_hdr hdr;
1557 struct buf *buf;
1558
1559 if (medium != NULL && medium->string != NULL)
1560 mediumlen = strlen(medium->string);
1561
1562 hdr.code = IMSG_SCRIPT_INIT;
1563 hdr.len = sizeof(struct imsg_hdr) +
1564 sizeof(size_t) + mediumlen +
1565 sizeof(size_t) + strlen(reason);
1566
1567 buf = buf_open(hdr.len);
1568
1569 buf_add(buf, &hdr, sizeof(hdr));
1570 buf_add(buf, &mediumlen, sizeof(mediumlen));
1571 if (mediumlen > 0)
1572 buf_add(buf, medium->string, mediumlen);
1573 len = strlen(reason);
1574 buf_add(buf, &len, sizeof(len));
1575 buf_add(buf, reason, len);
1576
1577 buf_close(privfd, buf);
1578 }
1579
1580 void
1581 priv_script_init(char *reason, char *medium)
1582 {
1583 client->scriptEnvsize = 100;
1584 if (client->scriptEnv == NULL)
1585 client->scriptEnv =
1586 calloc(client->scriptEnvsize, sizeof(char *));
1587 if (client->scriptEnv == NULL)
1588 error("script_init: no memory for environment");
1589
1590 client->scriptEnv[0] = strdup(CLIENT_PATH);
1591 if (client->scriptEnv[0] == NULL)
1592 error("script_init: no memory for environment");
1593
1594 client->scriptEnv[1] = NULL;
1595
1596 script_set_env("", "interface", ifi->name);
1597
1598 if (medium)
1599 script_set_env("", "medium", medium);
1600
1601 script_set_env("", "reason", reason);
1602 }
1603
1604 void
1605 priv_script_write_params(char *prefix, struct client_lease *lease)
1606 {
1607 u_int8_t dbuf[1500];
1608 int i, len = 0;
1609 char tbuf[128];
1610
1611 script_set_env(prefix, "ip_address", piaddr(lease->address));
1612
1613 if (lease->options[DHO_SUBNET_MASK].len &&
1614 (lease->options[DHO_SUBNET_MASK].len <
1615 sizeof(lease->address.iabuf))) {
1616 struct iaddr netmask, subnet, broadcast;
1617
1618 memcpy(netmask.iabuf, lease->options[DHO_SUBNET_MASK].data,
1619 lease->options[DHO_SUBNET_MASK].len);
1620 netmask.len = lease->options[DHO_SUBNET_MASK].len;
1621
1622 subnet = subnet_number(lease->address, netmask);
1623 if (subnet.len) {
1624 script_set_env(prefix, "network_number",
1625 piaddr(subnet));
1626 if (!lease->options[DHO_BROADCAST_ADDRESS].len) {
1627 broadcast = broadcast_addr(subnet, netmask);
1628 if (broadcast.len)
1629 script_set_env(prefix,
1630 "broadcast_address",
1631 piaddr(broadcast));
1632 }
1633 }
1634 }
1635
1636 if (lease->filename)
1637 script_set_env(prefix, "filename", lease->filename);
1638 if (lease->server_name)
1639 script_set_env(prefix, "server_name",
1640 lease->server_name);
1641 for (i = 0; i < 256; i++) {
1642 u_int8_t *dp = NULL;
1643
1644 if (config->defaults[i].len) {
1645 if (lease->options[i].len) {
1646 switch (config->default_actions[i]) {
1647 case ACTION_DEFAULT:
1648 dp = lease->options[i].data;
1649 len = lease->options[i].len;
1650 break;
1651 case ACTION_SUPERSEDE:
1652 supersede:
1653 dp = config->defaults[i].data;
1654 len = config->defaults[i].len;
1655 break;
1656 case ACTION_PREPEND:
1657 len = config->defaults[i].len +
1658 lease->options[i].len;
1659 if (len > sizeof(dbuf)) {
1660 warning("no space to %s %s",
1661 "prepend option",
1662 dhcp_options[i].name);
1663 goto supersede;
1664 }
1665 dp = dbuf;
1666 memcpy(dp,
1667 config->defaults[i].data,
1668 config->defaults[i].len);
1669 memcpy(dp +
1670 config->defaults[i].len,
1671 lease->options[i].data,
1672 lease->options[i].len);
1673 dp[len] = '\0';
1674 break;
1675 case ACTION_APPEND:
1676 len = config->defaults[i].len +
1677 lease->options[i].len;
1678 if (len > sizeof(dbuf)) {
1679 warning("no space to %s %s",
1680 "append option",
1681 dhcp_options[i].name);
1682 goto supersede;
1683 }
1684 dp = dbuf;
1685 memcpy(dp, lease->options[i].data,
1686 lease->options[i].len);
1687 memcpy(dp + lease->options[i].len,
1688 config->defaults[i].data,
1689 config->defaults[i].len);
1690 dp[len] = '\0';
1691 }
1692 } else {
1693 dp = config->defaults[i].data;
1694 len = config->defaults[i].len;
1695 }
1696 } else if (lease->options[i].len) {
1697 len = lease->options[i].len;
1698 dp = lease->options[i].data;
1699 } else {
1700 len = 0;
1701 }
1702 if (len) {
1703 char name[256];
1704
1705 if (dhcp_option_ev_name(name, sizeof(name),
1706 &dhcp_options[i]))
1707 script_set_env(prefix, name,
1708 pretty_print_option(i, dp, len, 0, 0));
1709 }
1710 }
1711 snprintf(tbuf, sizeof(tbuf), "%d", (int)lease->expiry);
1712 script_set_env(prefix, "expiry", tbuf);
1713 }
1714
1715 void
1716 script_write_params(char *prefix, struct client_lease *lease)
1717 {
1718 size_t fn_len = 0, sn_len = 0, pr_len = 0;
1719 struct imsg_hdr hdr;
1720 struct buf *buf;
1721 int i;
1722
1723 if (lease->filename != NULL)
1724 fn_len = strlen(lease->filename);
1725 if (lease->server_name != NULL)
1726 sn_len = strlen(lease->server_name);
1727 if (prefix != NULL)
1728 pr_len = strlen(prefix);
1729
1730 hdr.code = IMSG_SCRIPT_WRITE_PARAMS;
1731 hdr.len = sizeof(hdr) + sizeof(struct client_lease) +
1732 sizeof(size_t) + fn_len + sizeof(size_t) + sn_len +
1733 sizeof(size_t) + pr_len;
1734
1735 for (i = 0; i < 256; i++)
1736 hdr.len += sizeof(int) + lease->options[i].len;
1737
1738 scripttime = time(NULL);
1739
1740 buf = buf_open(hdr.len);
1741
1742 buf_add(buf, &hdr, sizeof(hdr));
1743 buf_add(buf, lease, sizeof(struct client_lease));
1744 buf_add(buf, &fn_len, sizeof(fn_len));
1745 buf_add(buf, lease->filename, fn_len);
1746 buf_add(buf, &sn_len, sizeof(sn_len));
1747 buf_add(buf, lease->server_name, sn_len);
1748 buf_add(buf, &pr_len, sizeof(pr_len));
1749 buf_add(buf, prefix, pr_len);
1750
1751 for (i = 0; i < 256; i++) {
1752 buf_add(buf, &lease->options[i].len,
1753 sizeof(lease->options[i].len));
1754 buf_add(buf, lease->options[i].data,
1755 lease->options[i].len);
1756 }
1757
1758 buf_close(privfd, buf);
1759 }
1760
1761 int
1762 script_go(void)
1763 {
1764 struct imsg_hdr hdr;
1765 struct buf *buf;
1766 int ret;
1767
1768 scripttime = time(NULL);
1769
1770 hdr.code = IMSG_SCRIPT_GO;
1771 hdr.len = sizeof(struct imsg_hdr);
1772
1773 buf = buf_open(hdr.len);
1774
1775 buf_add(buf, &hdr, sizeof(hdr));
1776 buf_close(privfd, buf);
1777
1778 bzero(&hdr, sizeof(hdr));
1779 buf_read(privfd, &hdr, sizeof(hdr));
1780 if (hdr.code != IMSG_SCRIPT_GO_RET)
1781 error("unexpected msg type %u", hdr.code);
1782 if (hdr.len != sizeof(hdr) + sizeof(int))
1783 error("received corrupted message");
1784 buf_read(privfd, &ret, sizeof(ret));
1785
1786 return (ret);
1787 }
1788
1789 int
1790 priv_script_go(void)
1791 {
1792 char *scriptName, *argv[2], **envp;
1793 int pid, wpid, wstatus;
1794
1795 scripttime = time(NULL);
1796
1797 scriptName = config->script_name;
1798 envp = client->scriptEnv;
1799
1800 argv[0] = scriptName;
1801 argv[1] = NULL;
1802
1803 pid = fork();
1804 if (pid < 0) {
1805 error("fork: %m");
1806 wstatus = 0;
1807 } else if (pid) {
1808 do {
1809 wpid = wait(&wstatus);
1810 } while (wpid != pid && wpid > 0);
1811 if (wpid < 0) {
1812 error("wait: %m");
1813 wstatus = 0;
1814 }
1815 } else {
1816 execve(scriptName, argv, envp);
1817 error("execve (%s, ...): %m", scriptName);
1818 }
1819
1820 script_flush_env();
1821
1822 return (WEXITSTATUS(wstatus));
1823 }
1824
1825 void
1826 script_set_env(const char *prefix, const char *name, const char *value)
1827 {
1828 int i, j, namelen;
1829
1830 namelen = strlen(name);
1831
1832 for (i = 0; client->scriptEnv[i]; i++)
1833 if (strncmp(client->scriptEnv[i], name, namelen) == 0 &&
1834 client->scriptEnv[i][namelen] == '=')
1835 break;
1836
1837 if (client->scriptEnv[i])
1838 /* Reuse the slot. */
1839 free(client->scriptEnv[i]);
1840 else {
1841 /* New variable. Expand if necessary. */
1842 if (i >= client->scriptEnvsize - 1) {
1843 char **newscriptEnv;
1844 int newscriptEnvsize = client->scriptEnvsize + 50;
1845
1846 newscriptEnv = realloc(client->scriptEnv,
1847 newscriptEnvsize);
1848 if (newscriptEnv == NULL) {
1849 free(client->scriptEnv);
1850 client->scriptEnv = NULL;
1851 client->scriptEnvsize = 0;
1852 error("script_set_env: no memory for variable");
1853 }
1854 client->scriptEnv = newscriptEnv;
1855 client->scriptEnvsize = newscriptEnvsize;
1856 }
1857 /* need to set the NULL pointer at end of array beyond
1858 the new slot. */
1859 client->scriptEnv[i + 1] = NULL;
1860 }
1861 /* Allocate space and format the variable in the appropriate slot. */
1862 client->scriptEnv[i] = malloc(strlen(prefix) + strlen(name) + 1 +
1863 strlen(value) + 1);
1864 if (client->scriptEnv[i] == NULL)
1865 error("script_set_env: no memory for variable assignment");
1866
1867 /* No `` or $() command substitution allowed in environment values! */
1868 for (j = 0; j < strlen(value); j++)
1869 switch (value[j]) {
1870 case '`':
1871 case '$':
1872 error("illegal character (%c) in value '%s'", value[j],
1873 value);
1874 /* not reached */
1875 }
1876 snprintf(client->scriptEnv[i], strlen(prefix) + strlen(name) +
1877 1 + strlen(value) + 1, "%s%s=%s", prefix, name, value);
1878 }
1879
1880 void
1881 script_flush_env(void)
1882 {
1883 int i;
1884
1885 for (i = 0; client->scriptEnv[i]; i++) {
1886 free(client->scriptEnv[i]);
1887 client->scriptEnv[i] = NULL;
1888 }
1889 client->scriptEnvsize = 0;
1890 }
1891
1892 int
1893 dhcp_option_ev_name(char *buf, size_t buflen, const struct option *option)
1894 {
1895 size_t i;
1896
1897 for (i = 0; option->name[i]; i++) {
1898 if (i + 1 == buflen)
1899 return 0;
1900 if (option->name[i] == '-')
1901 buf[i] = '_';
1902 else
1903 buf[i] = option->name[i];
1904 }
1905
1906 buf[i] = 0;
1907 return 1;
1908 }
1909
1910 void
1911 go_daemon(void)
1912 {
1913 static int state = 0;
1914
1915 if (no_daemon || state)
1916 return;
1917
1918 state = 1;
1919
1920 /* Stop logging to stderr... */
1921 log_perror = 0;
1922
1923 if (daemon(1, 0) == -1)
1924 error("daemon");
1925
1926 /* we are chrooted, daemon(3) fails to open /dev/null */
1927 if (nullfd != -1) {
1928 dup2(nullfd, STDIN_FILENO);
1929 dup2(nullfd, STDOUT_FILENO);
1930 dup2(nullfd, STDERR_FILENO);
1931 close(nullfd);
1932 nullfd = -1;
1933 }
1934 }
1935
1936 int
1937 check_option(struct client_lease *l, int option)
1938 {
1939 char *opbuf;
1940 char *sbuf;
1941
1942 /* we use this, since this is what gets passed to dhclient-script */
1943
1944 opbuf = pretty_print_option(option, l->options[option].data,
1945 l->options[option].len, 0, 0);
1946
1947 sbuf = option_as_string(option, l->options[option].data,
1948 l->options[option].len);
1949
1950 switch (option) {
1951 case DHO_SUBNET_MASK:
1952 case DHO_TIME_SERVERS:
1953 case DHO_NAME_SERVERS:
1954 case DHO_ROUTERS:
1955 case DHO_DOMAIN_NAME_SERVERS:
1956 case DHO_LOG_SERVERS:
1957 case DHO_COOKIE_SERVERS:
1958 case DHO_LPR_SERVERS:
1959 case DHO_IMPRESS_SERVERS:
1960 case DHO_RESOURCE_LOCATION_SERVERS:
1961 case DHO_SWAP_SERVER:
1962 case DHO_BROADCAST_ADDRESS:
1963 case DHO_NIS_SERVERS:
1964 case DHO_NTP_SERVERS:
1965 case DHO_NETBIOS_NAME_SERVERS:
1966 case DHO_NETBIOS_DD_SERVER:
1967 case DHO_FONT_SERVERS:
1968 case DHO_DHCP_SERVER_IDENTIFIER:
1969 if (!ipv4addrs(opbuf)) {
1970 warning("Invalid IP address in option: %s", opbuf);
1971 return (0);
1972 }
1973 return (1);
1974 case DHO_HOST_NAME:
1975 case DHO_DOMAIN_NAME:
1976 case DHO_NIS_DOMAIN:
1977 if (!res_hnok(sbuf)) {
1978 warning("Bogus Host Name option %d: %s (%s)", option,
1979 sbuf, opbuf);
1980 l->options[option].len = 0;
1981 free(l->options[option].data);
1982 }
1983 return (1);
1984 case DHO_PAD:
1985 case DHO_TIME_OFFSET:
1986 case DHO_BOOT_SIZE:
1987 case DHO_MERIT_DUMP:
1988 case DHO_ROOT_PATH:
1989 case DHO_EXTENSIONS_PATH:
1990 case DHO_IP_FORWARDING:
1991 case DHO_NON_LOCAL_SOURCE_ROUTING:
1992 case DHO_POLICY_FILTER:
1993 case DHO_MAX_DGRAM_REASSEMBLY:
1994 case DHO_DEFAULT_IP_TTL:
1995 case DHO_PATH_MTU_AGING_TIMEOUT:
1996 case DHO_PATH_MTU_PLATEAU_TABLE:
1997 case DHO_INTERFACE_MTU:
1998 case DHO_ALL_SUBNETS_LOCAL:
1999 case DHO_PERFORM_MASK_DISCOVERY:
2000 case DHO_MASK_SUPPLIER:
2001 case DHO_ROUTER_DISCOVERY:
2002 case DHO_ROUTER_SOLICITATION_ADDRESS:
2003 case DHO_STATIC_ROUTES:
2004 case DHO_TRAILER_ENCAPSULATION:
2005 case DHO_ARP_CACHE_TIMEOUT:
2006 case DHO_IEEE802_3_ENCAPSULATION:
2007 case DHO_DEFAULT_TCP_TTL:
2008 case DHO_TCP_KEEPALIVE_INTERVAL:
2009 case DHO_TCP_KEEPALIVE_GARBAGE:
2010 case DHO_VENDOR_ENCAPSULATED_OPTIONS:
2011 case DHO_NETBIOS_NODE_TYPE:
2012 case DHO_NETBIOS_SCOPE:
2013 case DHO_X_DISPLAY_MANAGER:
2014 case DHO_DHCP_REQUESTED_ADDRESS:
2015 case DHO_DHCP_LEASE_TIME:
2016 case DHO_DHCP_OPTION_OVERLOAD:
2017 case DHO_DHCP_MESSAGE_TYPE:
2018 case DHO_DHCP_PARAMETER_REQUEST_LIST:
2019 case DHO_DHCP_MESSAGE:
2020 case DHO_DHCP_MAX_MESSAGE_SIZE:
2021 case DHO_DHCP_RENEWAL_TIME:
2022 case DHO_DHCP_REBINDING_TIME:
2023 case DHO_DHCP_CLASS_IDENTIFIER:
2024 case DHO_DHCP_CLIENT_IDENTIFIER:
2025 case DHO_DHCP_USER_CLASS_ID:
2026 case DHO_END:
2027 return (1);
2028 default:
2029 warning("unknown dhcp option value 0x%x", option);
2030 return (unknown_ok);
2031 }
2032 }
2033
2034 int
2035 res_hnok(const char *name)
2036 {
2037 const char *dn = name;
2038 int pch = '.', ch = *dn++;
2039 int warn = 0;
2040
2041 while (ch != '\0') {
2042 int nch = *dn++;
2043
2044 if (ch == '.') {
2045 ;
2046 } else if (pch == '.' || nch == '.' || nch == '\0') {
2047 if (!isalnum(ch))
2048 return (0);
2049 } else if (!isalnum(ch) && ch != '-' && ch != '_')
2050 return (0);
2051 else if (ch == '_' && warn == 0) {
2052 warning("warning: hostname %s contains an "
2053 "underscore which violates RFC 952", name);
2054 warn++;
2055 }
2056 pch = ch, ch = nch;
2057 }
2058 return (1);
2059 }
2060
2061 /* Does buf consist only of dotted decimal ipv4 addrs?
2062 * return how many if so,
2063 * otherwise, return 0
2064 */
2065 int
2066 ipv4addrs(char * buf)
2067 {
2068 struct in_addr jnk;
2069 int count = 0;
2070
2071 while (inet_aton(buf, &jnk) == 1){
2072 count++;
2073 while (*buf == '.' || isdigit(*buf))
2074 buf++;
2075 if (*buf == '\0')
2076 return (count);
2077 while (*buf == ' ')
2078 buf++;
2079 }
2080 return (0);
2081 }
2082
2083 char *
2084 option_as_string(unsigned int code, unsigned char *data, int len)
2085 {
2086 static char optbuf[32768]; /* XXX */
2087 char *op = optbuf;
2088 int opleft = sizeof(optbuf);
2089 unsigned char *dp = data;
2090
2091 if (code > 255)
2092 error("option_as_string: bad code %d", code);
2093
2094 for (; dp < data + len; dp++) {
2095 if (!isascii(*dp) || !isprint(*dp)) {
2096 if (dp + 1 != data + len || *dp != 0) {
2097 size_t oplen;
2098 snprintf(op, opleft, "\\%03o", *dp);
2099 oplen = strlen(op);
2100 op += oplen;
2101 opleft -= oplen;
2102 }
2103 } else if (*dp == '"' || *dp == '\'' || *dp == '$' ||
2104 *dp == '`' || *dp == '\\') {
2105 *op++ = '\\';
2106 *op++ = *dp;
2107 opleft -= 2;
2108 } else {
2109 *op++ = *dp;
2110 opleft--;
2111 }
2112 }
2113 if (opleft < 1)
2114 goto toobig;
2115 *op = 0;
2116 return optbuf;
2117 toobig:
2118 warning("dhcp option too large");
2119 return "<error>";
2120 }
2121
2122 int
2123 fork_privchld(int fd, int fd2)
2124 {
2125 struct pollfd pfd[1];
2126 int nfds;
2127
2128 switch (fork()) {
2129 case -1:
2130 error("cannot fork");
2131 break;
2132 case 0:
2133 break;
2134 default:
2135 return (0);
2136 }
2137
2138 if (chdir("/") == -1)
2139 error("chdir(\"/\")");
2140
2141 setproctitle("%s [priv]", ifi->name);
2142
2143 dup2(nullfd, STDIN_FILENO);
2144 dup2(nullfd, STDOUT_FILENO);
2145 dup2(nullfd, STDERR_FILENO);
2146 close(nullfd);
2147 close(fd2);
2148
2149 for (;;) {
2150 pfd[0].fd = fd;
2151 pfd[0].events = POLLIN;
2152 if ((nfds = poll(pfd, 1, INFTIM)) == -1)
2153 if (errno != EINTR)
2154 error("poll error");
2155
2156 if (nfds == 0 || !(pfd[0].revents & POLLIN))
2157 continue;
2158
2159 dispatch_imsg(fd);
2160 }
2161 }
DragonFly BSD