dhclient - Fix OpenBSD CVS ids to match current version.
[dragonfly.git] / sbin / dhclient / dhclient.c
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5b2020b1 1/* $OpenBSD: src/sbin/dhclient/dhclient.c,v 1.119 2008/05/26 03:11:48 deraadt Exp $ */
846204b6
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2
3/*
4 * Copyright 2004 Henning Brauer <henning@openbsd.org>
5 * Copyright (c) 1995, 1996, 1997, 1998, 1999
6 * The Internet Software Consortium. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of The Internet Software Consortium nor the names
18 * of its contributors may be used to endorse or promote products derived
19 * from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
22 * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
23 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
25 * DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
26 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
27 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
28 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
29 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
30 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
31 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
32 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * This software has been written for the Internet Software Consortium
36 * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
37 * Enterprises. To learn more about the Internet Software Consortium,
38 * see ``http://www.vix.com/isc''. To learn more about Vixie
39 * Enterprises, see ``http://www.vix.com''.
40 *
41 * This client was substantially modified and enhanced by Elliot Poger
42 * for use on Linux while he was working on the MosquitoNet project at
43 * Stanford.
44 *
45 * The current version owes much to Elliot's Linux enhancements, but
46 * was substantially reorganized and partially rewritten by Ted Lemon
47 * so as to use the same networking framework that the Internet Software
48 * Consortium DHCP server uses. Much system-specific configuration code
49 * was moved into a shell script so that as support for more operating
50 * systems is added, it will not be necessary to port and maintain
51 * system-specific configuration code to these operating systems - instead,
52 * the shell script can invoke the native tools to accomplish the same
53 * purpose.
54 */
55
56#include <ctype.h>
57#include <poll.h>
58#include <pwd.h>
a05d48e6 59#include <unistd.h>
846204b6
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60
61#include "dhcpd.h"
62#include "privsep.h"
63
64#define CLIENT_PATH "PATH=/usr/bin:/usr/sbin:/bin:/sbin"
65#define DEFAULT_LEASE_TIME 43200 /* 12 hours... */
66#define TIME_MAX 2147483647
a05d48e6
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67#define POLL_FAILURES 10
68#define POLL_FAILURE_WAIT 1 /* Back off multiplier (seconds) */
846204b6
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69
70time_t cur_time;
71
72char *path_dhclient_conf = _PATH_DHCLIENT_CONF;
73char *path_dhclient_db = NULL;
74
75int log_perror = 1;
76int privfd;
77int nullfd = -1;
78int no_daemon;
79int unknown_ok = 1;
80int routefd = -1;
81
82struct iaddr iaddr_broadcast = { 4, { 255, 255, 255, 255 } };
83struct in_addr inaddr_any;
84struct sockaddr_in sockaddr_broadcast;
85
86struct interface_info *ifi;
87struct client_state *client;
88struct client_config *config;
89
90int findproto(char *, int);
91struct sockaddr *get_ifa(char *, int);
92void usage(void);
93int check_option(struct client_lease *l, int option);
94int ipv4addrs(char * buf);
95int res_hnok(const char *dn);
96char *option_as_string(unsigned int code, unsigned char *data, int len);
97int fork_privchld(int, int);
98
99#define ROUNDUP(a) \
100 ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
101#define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))
102
103time_t scripttime;
104static FILE *leaseFile;
105
106int
107findproto(char *cp, int n)
108{
109 struct sockaddr *sa;
110 int i;
111
112 if (n == 0)
113 return -1;
114 for (i = 1; i; i <<= 1) {
115 if (i & n) {
116 sa = (struct sockaddr *)cp;
117 switch (i) {
118 case RTA_IFA:
119 case RTA_DST:
120 case RTA_GATEWAY:
121 case RTA_NETMASK:
122 if (sa->sa_family == AF_INET)
123 return AF_INET;
124 if (sa->sa_family == AF_INET6)
125 return AF_INET6;
126 break;
127 case RTA_IFP:
128 break;
129 }
130 ADVANCE(cp, sa);
131 }
132 }
133 return (-1);
134}
135
136struct sockaddr *
137get_ifa(char *cp, int n)
138{
139 struct sockaddr *sa;
140 int i;
141
142 if (n == 0)
143 return (NULL);
144 for (i = 1; i; i <<= 1)
145 if (i & n) {
146 sa = (struct sockaddr *)cp;
147 if (i == RTA_IFA)
148 return (sa);
149 ADVANCE(cp, sa);
150 }
151
152 return (NULL);
153}
be18cf74 154struct iaddr defaddr = { .len = 4 }; /* NULL is for silence warnings */
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155
156/* ARGSUSED */
157void
158routehandler(void)
159{
160 int linkstat;
161 char msg[2048];
162 struct rt_msghdr *rtm;
163 struct if_msghdr *ifm;
164 struct ifa_msghdr *ifam;
165 struct if_announcemsghdr *ifan;
166 struct client_lease *l;
167 time_t t = time(NULL);
168 struct sockaddr *sa;
169 struct iaddr a;
170 ssize_t n;
171
172 do {
173 n = read(routefd, &msg, sizeof(msg));
174 } while (n == -1 && errno == EINTR);
175
176 rtm = (struct rt_msghdr *)msg;
177 if (n < sizeof(rtm->rtm_msglen) || n < rtm->rtm_msglen ||
178 rtm->rtm_version != RTM_VERSION)
179 return;
180
181 switch (rtm->rtm_type) {
182 case RTM_NEWADDR:
183 ifam = (struct ifa_msghdr *)rtm;
184 if (ifam->ifam_index != ifi->index)
185 break;
186 if (findproto((char *)(ifam + 1), ifam->ifam_addrs) != AF_INET)
187 break;
188 sa = get_ifa((char *)(ifam + 1), ifam->ifam_addrs);
189 if (sa == NULL)
190 goto die;
191
192 if ((a.len = sizeof(struct in_addr)) > sizeof(a.iabuf))
193 error("king bula sez: len mismatch");
194 memcpy(a.iabuf, &((struct sockaddr_in *)sa)->sin_addr, a.len);
195 if (addr_eq(a, defaddr))
196 break;
197
198 for (l = client->active; l != NULL; l = l->next)
199 if (addr_eq(a, l->address))
200 break;
201
202 if (l != NULL || (client->alias &&
203 addr_eq(a, client->alias->address)))
204 /* new addr is the one we set */
205 break;
206
207 goto die;
208 case RTM_DELADDR:
209 ifam = (struct ifa_msghdr *)rtm;
210 if (ifam->ifam_index != ifi->index)
211 break;
212 if (findproto((char *)(ifam + 1), ifam->ifam_addrs) != AF_INET)
213 break;
214 if (scripttime == 0 || t < scripttime + 10)
215 break;
216 goto die;
217 case RTM_IFINFO:
218 ifm = (struct if_msghdr *)rtm;
219 if (ifm->ifm_index != ifi->index)
220 break;
221 if ((rtm->rtm_flags & RTF_UP) == 0)
222 goto die;
223
224 linkstat =
225 LINK_STATE_IS_UP(ifm->ifm_data.ifi_link_state) ? 1 : 0;
226 if (linkstat != ifi->linkstat) {
227 debug("link state %s -> %s",
228 ifi->linkstat ? "up" : "down",
229 linkstat ? "up" : "down");
230 ifi->linkstat = interface_link_status(ifi->name);
231 if (ifi->linkstat) {
232 client->state = S_INIT;
233 state_reboot();
234 }
235 }
236 break;
237 case RTM_IFANNOUNCE:
238 ifan = (struct if_announcemsghdr *)rtm;
239 if (ifan->ifan_what == IFAN_DEPARTURE &&
240 ifan->ifan_index == ifi->index)
241 goto die;
242 break;
243 default:
244 break;
245 }
246 return;
247
248die:
249 script_init("FAIL", NULL);
250 if (client->alias)
251 script_write_params("alias_", client->alias);
252 script_go();
253 exit(1);
254}
255
256int
257main(int argc, char *argv[])
258{
259 int ch, fd, quiet = 0, i = 0, pipe_fd[2];
260 struct passwd *pw;
261
262 /* Initially, log errors to stderr as well as to syslogd. */
263 openlog(getprogname(), LOG_PID | LOG_NDELAY, DHCPD_LOG_FACILITY);
264 setlogmask(LOG_UPTO(LOG_INFO));
265
266 while ((ch = getopt(argc, argv, "c:dl:qu")) != -1)
267 switch (ch) {
268 case 'c':
269 path_dhclient_conf = optarg;
270 break;
271 case 'd':
272 no_daemon = 1;
273 break;
274 case 'l':
275 path_dhclient_db = optarg;
276 break;
277 case 'q':
278 quiet = 1;
279 break;
280 case 'u':
281 unknown_ok = 0;
282 break;
283 default:
284 usage();
285 }
286
287 argc -= optind;
288 argv += optind;
289
290 if (argc != 1)
291 usage();
292
293 ifi = calloc(1, sizeof(*ifi));
294 if (ifi == NULL)
295 error("ifi calloc");
296 client = calloc(1, sizeof(*client));
297 if (client == NULL)
298 error("client calloc");
299 config = calloc(1, sizeof(*config));
300 if (config == NULL)
301 error("config calloc");
302
303 if (strlcpy(ifi->name, argv[0], IFNAMSIZ) >= IFNAMSIZ)
304 error("Interface name too long");
305 if (path_dhclient_db == NULL && asprintf(&path_dhclient_db, "%s.%s",
306 _PATH_DHCLIENT_DB, ifi->name) == -1)
307 error("asprintf");
308
309 if (quiet)
310 log_perror = 0;
311
312 tzset();
313 time(&cur_time);
314
315 memset(&sockaddr_broadcast, 0, sizeof(sockaddr_broadcast));
316 sockaddr_broadcast.sin_family = AF_INET;
317 sockaddr_broadcast.sin_port = htons(REMOTE_PORT);
318 sockaddr_broadcast.sin_addr.s_addr = INADDR_BROADCAST;
319 sockaddr_broadcast.sin_len = sizeof(sockaddr_broadcast);
320 inaddr_any.s_addr = INADDR_ANY;
321
322 read_client_conf();
323
324 if (interface_status(ifi->name) == 0) {
325 interface_link_forceup(ifi->name);
326 /* Give it up to 4 seconds of silent grace to find link */
327 i = -4;
328 } else
329 i = 0;
330
331 while (!(ifi->linkstat = interface_link_status(ifi->name))) {
332 if (i == 0)
333 fprintf(stderr, "%s: no link ...", ifi->name);
334 else if (i > 0)
335 fprintf(stderr, ".");
336 fflush(stderr);
337 if (++i > config->link_timeout) {
338 fprintf(stderr, " sleeping\n");
339 goto dispatch;
340 }
341 sleep(1);
846204b6 342 }
77a69a5f
MS
343 if (i >= 0)
344 fprintf(stderr, " got link\n");
846204b6
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345
346 dispatch:
347 if ((nullfd = open(_PATH_DEVNULL, O_RDWR, 0)) == -1)
348 error("cannot open %s: %m", _PATH_DEVNULL);
349
350 if ((pw = getpwnam("_dhcp")) == NULL) {
351 warning("no such user: _dhcp, falling back to \"nobody\"");
352 if ((pw = getpwnam("nobody")) == NULL)
353 error("no such user: nobody");
354 }
355
356 if (pipe(pipe_fd) == -1)
357 error("pipe");
358
359 fork_privchld(pipe_fd[0], pipe_fd[1]);
360
361 close(pipe_fd[0]);
362 privfd = pipe_fd[1];
363
364 if ((fd = open(path_dhclient_db, O_RDONLY|O_EXLOCK|O_CREAT, 0)) == -1)
365 error("can't open and lock %s: %m", path_dhclient_db);
366 read_client_leases();
367 if ((leaseFile = fopen(path_dhclient_db, "w")) == NULL)
368 error("can't open %s: %m", path_dhclient_db);
369 rewrite_client_leases();
370 close(fd);
371
372 priv_script_init("PREINIT", NULL);
373 if (client->alias)
374 priv_script_write_params("alias_", client->alias);
375 priv_script_go();
376
377 if ((routefd = socket(PF_ROUTE, SOCK_RAW, 0)) == -1)
378 error("socket(PF_ROUTE, SOCK_RAW): %m");
379
380 /* set up the interface */
381 discover_interface();
382
383 if (chroot(_PATH_VAREMPTY) == -1)
384 error("chroot");
385 if (chdir("/") == -1)
386 error("chdir(\"/\")");
387
388 if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1)
389 error("setresgid");
390 if (setgroups(1, &pw->pw_gid) == -1)
391 error("setgroups");
392 if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1)
393 error("setresuid");
394
395 endpwent();
396
397 setproctitle("%s", ifi->name);
398
399 if (ifi->linkstat) {
400 client->state = S_INIT;
401 state_reboot();
402 } else
403 go_daemon();
404
405 dispatch();
406
407 /* not reached */
408 return (0);
409}
410
411void
412usage(void)
413{
414 fprintf(stderr, "usage: %s [-dqu] [-c file] [-l file] interface\n",
415 getprogname());
416 exit(1);
417}
418
419/*
420 * Individual States:
421 *
422 * Each routine is called from the dhclient_state_machine() in one of
423 * these conditions:
424 * -> entering INIT state
425 * -> recvpacket_flag == 0: timeout in this state
426 * -> otherwise: received a packet in this state
427 *
428 * Return conditions as handled by dhclient_state_machine():
429 * Returns 1, sendpacket_flag = 1: send packet, reset timer.
430 * Returns 1, sendpacket_flag = 0: just reset the timer (wait for a milestone).
431 * Returns 0: finish the nap which was interrupted for no good reason.
432 *
433 * Several per-interface variables are used to keep track of the process:
434 * active_lease: the lease that is being used on the interface
435 * (null pointer if not configured yet).
436 * offered_leases: leases corresponding to DHCPOFFER messages that have
437 * been sent to us by DHCP servers.
438 * acked_leases: leases corresponding to DHCPACK messages that have been
439 * sent to us by DHCP servers.
440 * sendpacket: DHCP packet we're trying to send.
441 * destination: IP address to send sendpacket to
442 * In addition, there are several relevant per-lease variables.
443 * T1_expiry, T2_expiry, lease_expiry: lease milestones
444 * In the active lease, these control the process of renewing the lease;
445 * In leases on the acked_leases list, this simply determines when we
446 * can no longer legitimately use the lease.
447 */
448void
449state_reboot(void)
450{
451 /* If we don't remember an active lease, go straight to INIT. */
452 if (!client->active || client->active->is_bootp) {
453 state_init();
454 return;
455 }
456
457 /* We are in the rebooting state. */
458 client->state = S_REBOOTING;
459
460 /* make_request doesn't initialize xid because it normally comes
461 from the DHCPDISCOVER, but we haven't sent a DHCPDISCOVER,
462 so pick an xid now. */
463 client->xid = arc4random();
464
465 /* Make a DHCPREQUEST packet, and set appropriate per-interface
466 flags. */
467 make_request(client->active);
468 client->destination = iaddr_broadcast;
469 client->first_sending = cur_time;
470 client->interval = config->initial_interval;
471
472 /* Zap the medium list... */
473 client->medium = NULL;
474
475 /* Send out the first DHCPREQUEST packet. */
476 send_request();
477}
478
479/*
480 * Called when a lease has completely expired and we've
481 * been unable to renew it.
482 */
483void
484state_init(void)
485{
486 /* Make a DHCPDISCOVER packet, and set appropriate per-interface
487 flags. */
488 make_discover(client->active);
489 client->xid = client->packet.xid;
490 client->destination = iaddr_broadcast;
491 client->state = S_SELECTING;
492 client->first_sending = cur_time;
493 client->interval = config->initial_interval;
494
495 /* Add an immediate timeout to cause the first DHCPDISCOVER packet
496 to go out. */
497 send_discover();
498}
499
500/*
501 * state_selecting is called when one or more DHCPOFFER packets
502 * have been received and a configurable period of time has passed.
503 */
504void
505state_selecting(void)
506{
507 struct client_lease *lp, *next, *picked;
508
509 /* Cancel state_selecting and send_discover timeouts, since either
510 one could have got us here. */
511 cancel_timeout(state_selecting);
512 cancel_timeout(send_discover);
513
514 /* We have received one or more DHCPOFFER packets. Currently,
515 the only criterion by which we judge leases is whether or
516 not we get a response when we arp for them. */
517 picked = NULL;
518 for (lp = client->offered_leases; lp; lp = next) {
519 next = lp->next;
520
521 /* Check to see if we got an ARPREPLY for the address
522 in this particular lease. */
523 if (!picked) {
524 script_init("ARPCHECK", lp->medium);
525 script_write_params("check_", lp);
526
527 /* If the ARPCHECK code detects another
528 machine using the offered address, it exits
529 nonzero. We need to send a DHCPDECLINE and
530 toss the lease. */
531 if (script_go()) {
532 make_decline(lp);
533 send_decline();
534 goto freeit;
535 }
536 picked = lp;
537 picked->next = NULL;
538 } else {
539freeit:
540 free_client_lease(lp);
541 }
542 }
543 client->offered_leases = NULL;
544
545 /* If we just tossed all the leases we were offered, go back
546 to square one. */
547 if (!picked) {
548 client->state = S_INIT;
549 state_init();
550 return;
551 }
552
553 /* If it was a BOOTREPLY, we can just take the address right now. */
554 if (!picked->options[DHO_DHCP_MESSAGE_TYPE].len) {
555 client->new = picked;
556
557 /* Make up some lease expiry times
558 XXX these should be configurable. */
559 client->new->expiry = cur_time + 12000;
560 client->new->renewal += cur_time + 8000;
561 client->new->rebind += cur_time + 10000;
562
563 client->state = S_REQUESTING;
564
565 /* Bind to the address we received. */
566 bind_lease();
567 return;
568 }
569
570 /* Go to the REQUESTING state. */
571 client->destination = iaddr_broadcast;
572 client->state = S_REQUESTING;
573 client->first_sending = cur_time;
574 client->interval = config->initial_interval;
575
576 /* Make a DHCPREQUEST packet from the lease we picked. */
577 make_request(picked);
578 client->xid = client->packet.xid;
579
580 /* Toss the lease we picked - we'll get it back in a DHCPACK. */
581 free_client_lease(picked);
582
583 /* Add an immediate timeout to send the first DHCPREQUEST packet. */
584 send_request();
585}
586
587void
588dhcpack(struct iaddr client_addr, struct option_data *options)
589{
590 struct client_lease *lease;
591
592 if (client->xid != client->packet.xid)
593 return;
594
595 if (client->state != S_REBOOTING &&
596 client->state != S_REQUESTING &&
597 client->state != S_RENEWING &&
598 client->state != S_REBINDING)
599 return;
600
601 note("DHCPACK from %s", piaddr(client_addr));
602
603 lease = packet_to_lease(options);
604 if (!lease) {
605 note("packet_to_lease failed.");
606 return;
607 }
608
609 client->new = lease;
610
611 /* Stop resending DHCPREQUEST. */
612 cancel_timeout(send_request);
613
614 /* Figure out the lease time. */
615 if (client->new->options[DHO_DHCP_LEASE_TIME].data)
616 client->new->expiry =
617 getULong(client->new->options[DHO_DHCP_LEASE_TIME].data);
618 else
619 client->new->expiry = DEFAULT_LEASE_TIME;
620 /* A number that looks negative here is really just very large,
621 because the lease expiry offset is unsigned. */
622 if (client->new->expiry < 0)
623 client->new->expiry = TIME_MAX;
624 /* XXX should be fixed by resetting the client state */
625 if (client->new->expiry < 60)
626 client->new->expiry = 60;
627
628 /* Take the server-provided renewal time if there is one;
629 otherwise figure it out according to the spec. */
630 if (client->new->options[DHO_DHCP_RENEWAL_TIME].len)
631 client->new->renewal =
632 getULong(client->new->options[DHO_DHCP_RENEWAL_TIME].data);
633 else
634 client->new->renewal = client->new->expiry / 2;
635
636 /* Same deal with the rebind time. */
637 if (client->new->options[DHO_DHCP_REBINDING_TIME].len)
638 client->new->rebind =
639 getULong(client->new->options[DHO_DHCP_REBINDING_TIME].data);
640 else
641 client->new->rebind = client->new->renewal +
642 client->new->renewal / 2 + client->new->renewal / 4;
643
644 client->new->expiry += cur_time;
645 /* Lease lengths can never be negative. */
646 if (client->new->expiry < cur_time)
647 client->new->expiry = TIME_MAX;
648 client->new->renewal += cur_time;
649 if (client->new->renewal < cur_time)
650 client->new->renewal = TIME_MAX;
651 client->new->rebind += cur_time;
652 if (client->new->rebind < cur_time)
653 client->new->rebind = TIME_MAX;
654
655 bind_lease();
656}
657
658void
659bind_lease(void)
660{
661 /* Remember the medium. */
662 client->new->medium = client->medium;
663
664 /* Write out the new lease. */
665 write_client_lease(client->new, 0);
666
667 /* Run the client script with the new parameters. */
668 script_init((client->state == S_REQUESTING ? "BOUND" :
669 (client->state == S_RENEWING ? "RENEW" :
670 (client->state == S_REBOOTING ? "REBOOT" : "REBIND"))),
671 client->new->medium);
672 if (client->active && client->state != S_REBOOTING)
673 script_write_params("old_", client->active);
674 script_write_params("new_", client->new);
675 if (client->alias)
676 script_write_params("alias_", client->alias);
677 script_go();
678
679 /* Replace the old active lease with the new one. */
680 if (client->active)
681 free_client_lease(client->active);
682 client->active = client->new;
683 client->new = NULL;
684
685 /* Set up a timeout to start the renewal process. */
686 add_timeout(client->active->renewal, state_bound);
687
688 note("bound to %s -- renewal in %ld seconds.",
689 piaddr(client->active->address),
690 client->active->renewal - cur_time);
691 client->state = S_BOUND;
692 reinitialize_interface();
693 go_daemon();
694}
695
696/*
697 * state_bound is called when we've successfully bound to a particular
698 * lease, but the renewal time on that lease has expired. We are
699 * expected to unicast a DHCPREQUEST to the server that gave us our
700 * original lease.
701 */
702void
703state_bound(void)
704{
705 /* T1 has expired. */
706 make_request(client->active);
707 client->xid = client->packet.xid;
708
709 if (client->active->options[DHO_DHCP_SERVER_IDENTIFIER].len == 4) {
710 memcpy(client->destination.iabuf,
711 client->active->options[DHO_DHCP_SERVER_IDENTIFIER].data,
712 4);
713 client->destination.len = 4;
714 } else
715 client->destination = iaddr_broadcast;
716
717 client->first_sending = cur_time;
718 client->interval = config->initial_interval;
719 client->state = S_RENEWING;
720
721 /* Send the first packet immediately. */
722 send_request();
723}
724
725void
726dhcpoffer(struct iaddr client_addr, struct option_data *options)
727{
728 struct client_lease *lease, *lp;
729 int i;
730 int arp_timeout_needed, stop_selecting;
731 char *name = options[DHO_DHCP_MESSAGE_TYPE].len ? "DHCPOFFER" :
732 "BOOTREPLY";
733
734 if (client->xid != client->packet.xid)
735 return;
736
737 if (client->state != S_SELECTING)
738 return;
739
740 note("%s from %s", name, piaddr(client_addr));
741
742 /* If this lease doesn't supply the minimum required parameters,
743 blow it off. */
744 for (i = 0; config->required_options[i]; i++) {
745 if (!options[config->required_options[i]].len) {
746 note("%s isn't satisfactory.", name);
747 return;
748 }
749 }
750
751 /* If we've already seen this lease, don't record it again. */
752 for (lease = client->offered_leases;
753 lease; lease = lease->next) {
754 if (lease->address.len == sizeof(client->packet.yiaddr) &&
755 !memcmp(lease->address.iabuf,
756 &client->packet.yiaddr, lease->address.len)) {
757 debug("%s already seen.", name);
758 return;
759 }
760 }
761
762 lease = packet_to_lease(options);
763 if (!lease) {
764 note("packet_to_lease failed.");
765 return;
766 }
767
768 /* If this lease was acquired through a BOOTREPLY, record that
769 fact. */
770 if (!options[DHO_DHCP_MESSAGE_TYPE].len)
771 lease->is_bootp = 1;
772
773 /* Record the medium under which this lease was offered. */
774 lease->medium = client->medium;
775
776 /* Send out an ARP Request for the offered IP address. */
777 script_init("ARPSEND", lease->medium);
778 script_write_params("check_", lease);
779 /* If the script can't send an ARP request without waiting,
780 we'll be waiting when we do the ARPCHECK, so don't wait now. */
781 if (script_go())
782 arp_timeout_needed = 0;
783 else
784 arp_timeout_needed = 2;
785
786 /* Figure out when we're supposed to stop selecting. */
787 stop_selecting = client->first_sending + config->select_interval;
788
789 /* If this is the lease we asked for, put it at the head of the
790 list, and don't mess with the arp request timeout. */
791 if (lease->address.len == client->requested_address.len &&
792 !memcmp(lease->address.iabuf,
793 client->requested_address.iabuf,
794 client->requested_address.len)) {
795 lease->next = client->offered_leases;
796 client->offered_leases = lease;
797 } else {
798 /* If we already have an offer, and arping for this
799 offer would take us past the selection timeout,
800 then don't extend the timeout - just hope for the
801 best. */
802 if (client->offered_leases &&
803 (cur_time + arp_timeout_needed) > stop_selecting)
804 arp_timeout_needed = 0;
805
806 /* Put the lease at the end of the list. */
807 lease->next = NULL;
808 if (!client->offered_leases)
809 client->offered_leases = lease;
810 else {
811 for (lp = client->offered_leases; lp->next;
812 lp = lp->next)
813 ; /* nothing */
814 lp->next = lease;
815 }
816 }
817
818 /* If we're supposed to stop selecting before we've had time
819 to wait for the ARPREPLY, add some delay to wait for
820 the ARPREPLY. */
821 if (stop_selecting - cur_time < arp_timeout_needed)
822 stop_selecting = cur_time + arp_timeout_needed;
823
824 /* If the selecting interval has expired, go immediately to
825 state_selecting(). Otherwise, time out into
826 state_selecting at the select interval. */
827 if (stop_selecting <= 0)
828 state_selecting();
829 else {
830 add_timeout(stop_selecting, state_selecting);
831 cancel_timeout(send_discover);
832 }
833}
834
835/*
836 * Allocate a client_lease structure and initialize it from the
837 * parameters in the specified packet.
838 */
839struct client_lease *
840packet_to_lease(struct option_data *options)
841{
842 struct client_lease *lease;
843 int i;
844
845 lease = malloc(sizeof(struct client_lease));
846
847 if (!lease) {
848 warning("dhcpoffer: no memory to record lease.");
849 return (NULL);
850 }
851
852 memset(lease, 0, sizeof(*lease));
853
854 /* Copy the lease options. */
855 for (i = 0; i < 256; i++) {
856 if (options[i].len) {
857 lease->options[i] = options[i];
858 options[i].data = NULL;
859 options[i].len = 0;
860 if (!check_option(lease, i)) {
861 warning("Invalid lease option - ignoring offer");
862 free_client_lease(lease);
863 return (NULL);
864 }
865 }
866 }
867
868 lease->address.len = sizeof(client->packet.yiaddr);
869 memcpy(lease->address.iabuf, &client->packet.yiaddr,
870 lease->address.len);
871
872 /* If the server name was filled out, copy it. */
873 if ((!lease->options[DHO_DHCP_OPTION_OVERLOAD].len ||
874 !(lease->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 2)) &&
875 client->packet.sname[0]) {
876 lease->server_name = malloc(DHCP_SNAME_LEN + 1);
877 if (!lease->server_name) {
878 warning("dhcpoffer: no memory for server name.");
879 free_client_lease(lease);
880 return (NULL);
881 }
882 memcpy(lease->server_name, client->packet.sname,
883 DHCP_SNAME_LEN);
884 lease->server_name[DHCP_SNAME_LEN] = '\0';
885 if (!res_hnok(lease->server_name)) {
886 warning("Bogus server name %s", lease->server_name);
887 free(lease->server_name);
888 lease->server_name = NULL;
889 }
890 }
891
892 /* Ditto for the filename. */
893 if ((!lease->options[DHO_DHCP_OPTION_OVERLOAD].len ||
894 !(lease->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 1)) &&
895 client->packet.file[0]) {
896 /* Don't count on the NUL terminator. */
897 lease->filename = malloc(DHCP_FILE_LEN + 1);
898 if (!lease->filename) {
899 warning("dhcpoffer: no memory for filename.");
900 free_client_lease(lease);
901 return (NULL);
902 }
903 memcpy(lease->filename, client->packet.file, DHCP_FILE_LEN);
904 lease->filename[DHCP_FILE_LEN] = '\0';
905 }
906 return lease;
907}
908
909void
910dhcpnak(struct iaddr client_addr, struct option_data *options)
911{
912 if (client->xid != client->packet.xid)
913 return;
914
915 if (client->state != S_REBOOTING &&
916 client->state != S_REQUESTING &&
917 client->state != S_RENEWING &&
918 client->state != S_REBINDING)
919 return;
920
921 note("DHCPNAK from %s", piaddr(client_addr));
922
923 if (!client->active) {
924 note("DHCPNAK with no active lease.");
925 return;
926 }
927
928 free_client_lease(client->active);
929 client->active = NULL;
930
931 /* Stop sending DHCPREQUEST packets... */
932 cancel_timeout(send_request);
933
934 client->state = S_INIT;
935 state_init();
936}
937
938/*
939 * Send out a DHCPDISCOVER packet, and set a timeout to send out another
940 * one after the right interval has expired. If we don't get an offer by
941 * the time we reach the panic interval, call the panic function.
942 */
943void
944send_discover(void)
945{
946 int interval, increase = 1;
947
948 /* Figure out how long it's been since we started transmitting. */
949 interval = cur_time - client->first_sending;
950
951 /* If we're past the panic timeout, call the script and tell it
952 we haven't found anything for this interface yet. */
953 if (interval > config->timeout) {
954 state_panic();
955 return;
956 }
957
958 /* If we're selecting media, try the whole list before doing
959 the exponential backoff, but if we've already received an
960 offer, stop looping, because we obviously have it right. */
961 if (!client->offered_leases && config->media) {
962 int fail = 0;
963again:
964 if (client->medium) {
965 client->medium = client->medium->next;
966 increase = 0;
967 }
968 if (!client->medium) {
969 if (fail)
970 error("No valid media types for %s!", ifi->name);
971 client->medium = config->media;
972 increase = 1;
973 }
974
975 note("Trying medium \"%s\" %d", client->medium->string,
976 increase);
977 script_init("MEDIUM", client->medium);
978 if (script_go())
979 goto again;
980 }
981
982 /*
983 * If we're supposed to increase the interval, do so. If it's
984 * currently zero (i.e., we haven't sent any packets yet), set
985 * it to initial_interval; otherwise, add to it a random
986 * number between zero and two times itself. On average, this
987 * means that it will double with every transmission.
988 */
989 if (increase) {
990 if (!client->interval)
991 client->interval = config->initial_interval;
992 else {
993 client->interval += (arc4random() >> 2) %
994 (2 * client->interval);
995 }
996
997 /* Don't backoff past cutoff. */
998 if (client->interval > config->backoff_cutoff)
999 client->interval = ((config->backoff_cutoff / 2)
1000 + ((arc4random() >> 2) %
1001 config->backoff_cutoff));
1002 } else if (!client->interval)
1003 client->interval = config->initial_interval;
1004
1005 /* If the backoff would take us to the panic timeout, just use that
1006 as the interval. */
1007 if (cur_time + client->interval >
1008 client->first_sending + config->timeout)
1009 client->interval = (client->first_sending +
1010 config->timeout) - cur_time + 1;
1011
1012 /* Record the number of seconds since we started sending. */
1013 if (interval < 65536)
1014 client->packet.secs = htons(interval);
1015 else
1016 client->packet.secs = htons(65535);
1017 client->secs = client->packet.secs;
1018
1019 note("DHCPDISCOVER on %s to %s port %d interval %ld",
1020 ifi->name, inet_ntoa(sockaddr_broadcast.sin_addr),
1021 ntohs(sockaddr_broadcast.sin_port), client->interval);
1022
1023 /* Send out a packet. */
1024 send_packet(inaddr_any, &sockaddr_broadcast, NULL);
1025
1026 add_timeout(cur_time + client->interval, send_discover);
1027}
1028
1029/*
1030 * state_panic gets called if we haven't received any offers in a preset
1031 * amount of time. When this happens, we try to use existing leases
1032 * that haven't yet expired, and failing that, we call the client script
1033 * and hope it can do something.
1034 */
1035void
1036state_panic(void)
1037{
1038 struct client_lease *loop = client->active;
1039 struct client_lease *lp;
1040
1041 note("No DHCPOFFERS received.");
1042
1043 /* We may not have an active lease, but we may have some
1044 predefined leases that we can try. */
1045 if (!client->active && client->leases)
1046 goto activate_next;
1047
1048 /* Run through the list of leases and see if one can be used. */
1049 while (client->active) {
1050 if (client->active->expiry > cur_time) {
1051 note("Trying recorded lease %s",
1052 piaddr(client->active->address));
1053 /* Run the client script with the existing
1054 parameters. */
1055 script_init("TIMEOUT",
1056 client->active->medium);
1057 script_write_params("new_", client->active);
1058 if (client->alias)
1059 script_write_params("alias_",
1060 client->alias);
1061
1062 /* If the old lease is still good and doesn't
1063 yet need renewal, go into BOUND state and
1064 timeout at the renewal time. */
1065 if (!script_go()) {
1066 if (cur_time <
1067 client->active->renewal) {
1068 client->state = S_BOUND;
1069 note("bound: renewal in %ld seconds.",
1070 client->active->renewal -
1071 cur_time);
1072 add_timeout(client->active->renewal,
1073 state_bound);
1074 } else {
1075 client->state = S_BOUND;
1076 note("bound: immediate renewal.");
1077 state_bound();
1078 }
1079 reinitialize_interface();
1080 go_daemon();
1081 return;
1082 }
1083 }
1084
1085 /* If there are no other leases, give up. */
1086 if (!client->leases) {
1087 client->leases = client->active;
1088 client->active = NULL;
1089 break;
1090 }
1091
1092activate_next:
1093 /* Otherwise, put the active lease at the end of the
1094 lease list, and try another lease.. */
1095 for (lp = client->leases; lp->next; lp = lp->next)
1096 ;
1097 lp->next = client->active;
1098 if (lp->next)
1099 lp->next->next = NULL;
1100 client->active = client->leases;
1101 client->leases = client->leases->next;
1102
1103 /* If we already tried this lease, we've exhausted the
1104 set of leases, so we might as well give up for
1105 now. */
1106 if (client->active == loop)
1107 break;
1108 else if (!loop)
1109 loop = client->active;
1110 }
1111
1112 /* No leases were available, or what was available didn't work, so
1113 tell the shell script that we failed to allocate an address,
1114 and try again later. */
1115 note("No working leases in persistent database - sleeping.");
1116 script_init("FAIL", NULL);
1117 if (client->alias)
1118 script_write_params("alias_", client->alias);
1119 script_go();
1120 client->state = S_INIT;
1121 add_timeout(cur_time + config->retry_interval, state_init);
1122 go_daemon();
1123}
1124
1125void
1126send_request(void)
1127{
1128 struct sockaddr_in destination;
1129 struct in_addr from;
1130 int interval;
1131
1132 /* Figure out how long it's been since we started transmitting. */
1133 interval = cur_time - client->first_sending;
1134
1135 /* If we're in the INIT-REBOOT or REQUESTING state and we're
1136 past the reboot timeout, go to INIT and see if we can
1137 DISCOVER an address... */
1138 /* XXX In the INIT-REBOOT state, if we don't get an ACK, it
1139 means either that we're on a network with no DHCP server,
1140 or that our server is down. In the latter case, assuming
1141 that there is a backup DHCP server, DHCPDISCOVER will get
1142 us a new address, but we could also have successfully
1143 reused our old address. In the former case, we're hosed
1144 anyway. This is not a win-prone situation. */
1145 if ((client->state == S_REBOOTING ||
1146 client->state == S_REQUESTING) &&
1147 interval > config->reboot_timeout) {
1148cancel:
1149 client->state = S_INIT;
1150 cancel_timeout(send_request);
1151 state_init();
1152 return;
1153 }
1154
1155 /* If we're in the reboot state, make sure the media is set up
1156 correctly. */
1157 if (client->state == S_REBOOTING &&
1158 !client->medium &&
1159 client->active->medium) {
1160 script_init("MEDIUM", client->active->medium);
1161
1162 /* If the medium we chose won't fly, go to INIT state. */
1163 if (script_go())
1164 goto cancel;
1165
1166 /* Record the medium. */
1167 client->medium = client->active->medium;
1168 }
1169
1170 /* If the lease has expired, relinquish the address and go back
1171 to the INIT state. */
1172 if (client->state != S_REQUESTING &&
1173 cur_time > client->active->expiry) {
1174 /* Run the client script with the new parameters. */
1175 script_init("EXPIRE", NULL);
1176 script_write_params("old_", client->active);
1177 if (client->alias)
1178 script_write_params("alias_", client->alias);
1179 script_go();
1180
1181 /* Now do a preinit on the interface so that we can
1182 discover a new address. */
1183 script_init("PREINIT", NULL);
1184 if (client->alias)
1185 script_write_params("alias_", client->alias);
1186 script_go();
1187
1188 client->state = S_INIT;
1189 state_init();
1190 return;
1191 }
1192
1193 /* Do the exponential backoff... */
1194 if (!client->interval)
1195 client->interval = config->initial_interval;
1196 else
1197 client->interval += ((arc4random() >> 2) %
1198 (2 * client->interval));
1199
1200 /* Don't backoff past cutoff. */
1201 if (client->interval > config->backoff_cutoff)
1202 client->interval = ((config->backoff_cutoff / 2) +
1203 ((arc4random() >> 2) % client->interval));
1204
1205 /* If the backoff would take us to the expiry time, just set the
1206 timeout to the expiry time. */
1207 if (client->state != S_REQUESTING && cur_time + client->interval >
1208 client->active->expiry)
1209 client->interval = client->active->expiry - cur_time + 1;
1210
1211 /* If the lease T2 time has elapsed, or if we're not yet bound,
1212 broadcast the DHCPREQUEST rather than unicasting. */
1213 memset(&destination, 0, sizeof(destination));
1214 if (client->state == S_REQUESTING ||
1215 client->state == S_REBOOTING ||
1216 cur_time > client->active->rebind)
1217 destination.sin_addr.s_addr = INADDR_BROADCAST;
1218 else
1219 memcpy(&destination.sin_addr.s_addr, client->destination.iabuf,
1220 sizeof(destination.sin_addr.s_addr));
1221 destination.sin_port = htons(REMOTE_PORT);
1222 destination.sin_family = AF_INET;
1223 destination.sin_len = sizeof(destination);
1224
1225 if (client->state != S_REQUESTING)
1226 memcpy(&from, client->active->address.iabuf, sizeof(from));
1227 else
1228 from.s_addr = INADDR_ANY;
1229
1230 /* Record the number of seconds since we started sending. */
1231 if (client->state == S_REQUESTING)
1232 client->packet.secs = client->secs;
1233 else {
1234 if (interval < 65536)
1235 client->packet.secs = htons(interval);
1236 else
1237 client->packet.secs = htons(65535);
1238 }
1239
1240 note("DHCPREQUEST on %s to %s port %d", ifi->name,
1241 inet_ntoa(destination.sin_addr), ntohs(destination.sin_port));
1242
1243 /* Send out a packet. */
1244 send_packet(from, &destination, NULL);
1245
1246 add_timeout(cur_time + client->interval, send_request);
1247}
1248
1249void
1250send_decline(void)
1251{
1252 note("DHCPDECLINE on %s to %s port %d", ifi->name,
1253 inet_ntoa(sockaddr_broadcast.sin_addr),
1254 ntohs(sockaddr_broadcast.sin_port));
1255
1256 /* Send out a packet. */
1257 send_packet(inaddr_any, &sockaddr_broadcast, NULL);
1258}
1259
1260void
1261make_discover(struct client_lease *lease)
1262{
1263 unsigned char discover = DHCPDISCOVER;
1264 struct option_data options[256];
1265 int i;
1266
1267 memset(options, 0, sizeof(options));
1268 memset(&client->packet, 0, sizeof(client->packet));
1269
1270 /* Set DHCP_MESSAGE_TYPE to DHCPDISCOVER */
1271 i = DHO_DHCP_MESSAGE_TYPE;
1272 options[i].data = &discover;
1273 options[i].len = sizeof(discover);
1274
1275 /* Request the options we want */
1276 i = DHO_DHCP_PARAMETER_REQUEST_LIST;
1277 options[i].data = config->requested_options;
1278 options[i].len = config->requested_option_count;
1279
1280 /* If we had an address, try to get it again. */
1281 if (lease) {
1282 client->requested_address = lease->address;
1283 i = DHO_DHCP_REQUESTED_ADDRESS;
1284 options[i].data = lease->address.iabuf;
1285 options[i].len = lease->address.len;
1286 } else
1287 client->requested_address.len = 0;
1288
1289 /* Send any options requested in the config file. */
1290 for (i = 0; i < 256; i++)
1291 if (!options[i].data &&
1292 config->send_options[i].data) {
1293 options[i].data = config->send_options[i].data;
1294 options[i].len = config->send_options[i].len;
1295 }
1296
1297 /* Set up the option buffer to fit in a minimal UDP packet. */
1298 i = cons_options(client->packet.options, 576 - DHCP_FIXED_LEN,
1299 options);
1300 if (i == -1 || client->packet.options[i] != DHO_END)
1301 error("options do not fit in DHCPDISCOVER packet.");
1302 client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1303 if (client->packet_length < BOOTP_MIN_LEN)
1304 client->packet_length = BOOTP_MIN_LEN;
1305
1306 client->packet.op = BOOTREQUEST;
1307 client->packet.htype = ifi->hw_address.htype;
1308 client->packet.hlen = ifi->hw_address.hlen;
1309 client->packet.hops = 0;
1310 client->packet.xid = arc4random();
1311 client->packet.secs = 0; /* filled in by send_discover. */
1312 client->packet.flags = 0;
1313
1314 memset(&client->packet.ciaddr, 0, sizeof(client->packet.ciaddr));
1315 memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1316 memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1317 memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1318 memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1319 ifi->hw_address.hlen);
1320}
1321
1322void
1323make_request(struct client_lease * lease)
1324{
1325 unsigned char request = DHCPREQUEST;
1326 struct option_data options[256];
1327 int i;
1328
1329 memset(options, 0, sizeof(options));
1330 memset(&client->packet, 0, sizeof(client->packet));
1331
1332 /* Set DHCP_MESSAGE_TYPE to DHCPREQUEST */
1333 i = DHO_DHCP_MESSAGE_TYPE;
1334 options[i].data = &request;
1335 options[i].len = sizeof(request);
1336
1337 /* Request the options we want */
1338 i = DHO_DHCP_PARAMETER_REQUEST_LIST;
1339 options[i].data = config->requested_options;
1340 options[i].len = config->requested_option_count;
1341
1342 /* If we are requesting an address that hasn't yet been assigned
1343 to us, use the DHCP Requested Address option. */
1344 if (client->state == S_REQUESTING) {
1345 /* Send back the server identifier... */
1346 i = DHO_DHCP_SERVER_IDENTIFIER;
1347 options[i].data = lease->options[i].data;
1348 options[i].len = lease->options[i].len;
1349 }
1350 if (client->state == S_REQUESTING ||
1351 client->state == S_REBOOTING) {
1352 client->requested_address = lease->address;
1353 i = DHO_DHCP_REQUESTED_ADDRESS;
1354 options[i].data = lease->address.iabuf;
1355 options[i].len = lease->address.len;
1356 } else
1357 client->requested_address.len = 0;
1358
1359 /* Send any options requested in the config file. */
1360 for (i = 0; i < 256; i++)
1361 if (!options[i].data && config->send_options[i].data) {
1362 options[i].data = config->send_options[i].data;
1363 options[i].len = config->send_options[i].len;
1364 }
1365
1366 /* Set up the option buffer to fit in a minimal UDP packet. */
1367 i = cons_options(client->packet.options, 576 - DHCP_FIXED_LEN,
1368 options);
1369 if (i == -1 || client->packet.options[i] != DHO_END)
1370 error("options do not fit in DHCPREQUEST packet.");
1371 client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1372 if (client->packet_length < BOOTP_MIN_LEN)
1373 client->packet_length = BOOTP_MIN_LEN;
1374
1375 client->packet.op = BOOTREQUEST;
1376 client->packet.htype = ifi->hw_address.htype;
1377 client->packet.hlen = ifi->hw_address.hlen;
1378 client->packet.hops = 0;
1379 client->packet.xid = client->xid;
1380 client->packet.secs = 0; /* Filled in by send_request. */
1381 client->packet.flags = 0;
1382
1383 /* If we own the address we're requesting, put it in ciaddr;
1384 otherwise set ciaddr to zero. */
1385 if (client->state == S_BOUND ||
1386 client->state == S_RENEWING ||
1387 client->state == S_REBINDING) {
1388 memcpy(&client->packet.ciaddr,
1389 lease->address.iabuf, lease->address.len);
1390 } else {
1391 memset(&client->packet.ciaddr, 0,
1392 sizeof(client->packet.ciaddr));
1393 }
1394
1395 memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1396 memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1397 memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1398 memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1399 ifi->hw_address.hlen);
1400}
1401
1402void
1403make_decline(struct client_lease *lease)
1404{
1405 struct option_data options[256];
1406 unsigned char decline = DHCPDECLINE;
1407 int i;
1408
1409 memset(options, 0, sizeof(options));
1410 memset(&client->packet, 0, sizeof(client->packet));
1411
1412 /* Set DHCP_MESSAGE_TYPE to DHCPDECLINE */
1413 i = DHO_DHCP_MESSAGE_TYPE;
1414 options[i].data = &decline;
1415 options[i].len = sizeof(decline);
1416
1417 /* Send back the server identifier... */
1418 i = DHO_DHCP_SERVER_IDENTIFIER;
1419 options[i].data = lease->options[i].data;
1420 options[i].len = lease->options[i].len;
1421
1422 /* Send back the address we're declining. */
1423 i = DHO_DHCP_REQUESTED_ADDRESS;
1424 options[i].data = lease->address.iabuf;
1425 options[i].len = lease->address.len;
1426
1427 /* Send the uid if the user supplied one. */
1428 i = DHO_DHCP_CLIENT_IDENTIFIER;
1429 if (config->send_options[i].len) {
1430 options[i].data = config->send_options[i].data;
1431 options[i].len = config->send_options[i].len;
1432 }
1433
1434 /* Set up the option buffer to fit in a minimal UDP packet. */
1435 i = cons_options(client->packet.options, 576 - DHCP_FIXED_LEN,
1436 options);
1437 if (i == -1 || client->packet.options[i] != DHO_END)
1438 error("options do not fit in DHCPDECLINE packet.");
1439 client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1440 if (client->packet_length < BOOTP_MIN_LEN)
1441 client->packet_length = BOOTP_MIN_LEN;
1442
1443 client->packet.op = BOOTREQUEST;
1444 client->packet.htype = ifi->hw_address.htype;
1445 client->packet.hlen = ifi->hw_address.hlen;
1446 client->packet.hops = 0;
1447 client->packet.xid = client->xid;
1448 client->packet.secs = 0; /* Filled in by send_request. */
1449 client->packet.flags = 0;
1450
1451 /* ciaddr must always be zero. */
1452 memset(&client->packet.ciaddr, 0, sizeof(client->packet.ciaddr));
1453 memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1454 memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1455 memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1456 memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1457 ifi->hw_address.hlen);
1458}
1459
1460void
1461free_client_lease(struct client_lease *lease)
1462{
1463 int i;
1464
1465 if (lease->server_name)
1466 free(lease->server_name);
1467 if (lease->filename)
1468 free(lease->filename);
1469 for (i = 0; i < 256; i++) {
1470 if (lease->options[i].len)
1471 free(lease->options[i].data);
1472 }
1473 free(lease);
1474}
1475
1476void
1477rewrite_client_leases(void)
1478{
1479 struct client_lease *lp;
1480
1481 if (!leaseFile) /* XXX */
1482 error("lease file not open");
1483
1484 fflush(leaseFile);
1485 rewind(leaseFile);
1486
1487 for (lp = client->leases; lp; lp = lp->next)
1488 write_client_lease(lp, 1);
1489 if (client->active)
1490 write_client_lease(client->active, 1);
1491
1492 fflush(leaseFile);
1493 ftruncate(fileno(leaseFile), ftello(leaseFile));
1494 fsync(fileno(leaseFile));
1495}
1496
1497void
1498write_client_lease(struct client_lease *lease, int rewrite)
1499{
1500 static int leases_written;
1501 struct tm *t;
1502 int i;
1503
1504 if (!rewrite) {
1505 if (leases_written++ > 20) {
1506 rewrite_client_leases();
1507 leases_written = 0;
1508 }
1509 }
1510
1511 /* If the lease came from the config file, we don't need to stash
1512 a copy in the lease database. */
1513 if (lease->is_static)
1514 return;
1515
1516 if (!leaseFile) /* XXX */
1517 error("lease file not open");
1518
1519 fprintf(leaseFile, "lease {\n");
1520 if (lease->is_bootp)
1521 fprintf(leaseFile, " bootp;\n");
1522 fprintf(leaseFile, " interface \"%s\";\n", ifi->name);
1523 fprintf(leaseFile, " fixed-address %s;\n", piaddr(lease->address));
1524 if (lease->filename)
1525 fprintf(leaseFile, " filename \"%s\";\n", lease->filename);
1526 if (lease->server_name)
1527 fprintf(leaseFile, " server-name \"%s\";\n",
1528 lease->server_name);
1529 if (lease->medium)
1530 fprintf(leaseFile, " medium \"%s\";\n", lease->medium->string);
1531 for (i = 0; i < 256; i++)
1532 if (lease->options[i].len)
1533 fprintf(leaseFile, " option %s %s;\n",
1534 dhcp_options[i].name,
1535 pretty_print_option(i, lease->options[i].data,
1536 lease->options[i].len, 1, 1));
1537
1538 t = gmtime(&lease->renewal);
1539 fprintf(leaseFile, " renew %d %d/%d/%d %02d:%02d:%02d;\n",
1540 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1541 t->tm_hour, t->tm_min, t->tm_sec);
1542 t = gmtime(&lease->rebind);
1543 fprintf(leaseFile, " rebind %d %d/%d/%d %02d:%02d:%02d;\n",
1544 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1545 t->tm_hour, t->tm_min, t->tm_sec);
1546 t = gmtime(&lease->expiry);
1547 fprintf(leaseFile, " expire %d %d/%d/%d %02d:%02d:%02d;\n",
1548 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1549 t->tm_hour, t->tm_min, t->tm_sec);
1550 fprintf(leaseFile, "}\n");
1551 fflush(leaseFile);
1552}
1553
1554void
1555script_init(char *reason, struct string_list *medium)
1556{
1557 size_t len, mediumlen = 0;
1558 struct imsg_hdr hdr;
1559 struct buf *buf;
1560
1561 if (medium != NULL && medium->string != NULL)
1562 mediumlen = strlen(medium->string);
1563
1564 hdr.code = IMSG_SCRIPT_INIT;
1565 hdr.len = sizeof(struct imsg_hdr) +
1566 sizeof(size_t) + mediumlen +
1567 sizeof(size_t) + strlen(reason);
1568
1569 buf = buf_open(hdr.len);
1570
1571 buf_add(buf, &hdr, sizeof(hdr));
1572 buf_add(buf, &mediumlen, sizeof(mediumlen));
1573 if (mediumlen > 0)
1574 buf_add(buf, medium->string, mediumlen);
1575 len = strlen(reason);
1576 buf_add(buf, &len, sizeof(len));
1577 buf_add(buf, reason, len);
1578
1579 buf_close(privfd, buf);
1580}
1581
1582void
1583priv_script_init(char *reason, char *medium)
1584{
1585 client->scriptEnvsize = 100;
1586 if (client->scriptEnv == NULL)
1587 client->scriptEnv =
1588 calloc(client->scriptEnvsize, sizeof(char *));
1589 if (client->scriptEnv == NULL)
1590 error("script_init: no memory for environment");
1591
1592 client->scriptEnv[0] = strdup(CLIENT_PATH);
1593 if (client->scriptEnv[0] == NULL)
1594 error("script_init: no memory for environment");
1595
1596 client->scriptEnv[1] = NULL;
1597
1598 script_set_env("", "interface", ifi->name);
1599
1600 if (medium)
1601 script_set_env("", "medium", medium);
1602
1603 script_set_env("", "reason", reason);
1604}
1605
1606void
1607priv_script_write_params(char *prefix, struct client_lease *lease)
1608{
1609 u_int8_t dbuf[1500];
1610 int i, len = 0;
1611 char tbuf[128];
1612
1613 script_set_env(prefix, "ip_address", piaddr(lease->address));
1614
1615 if (lease->options[DHO_SUBNET_MASK].len &&
1616 (lease->options[DHO_SUBNET_MASK].len <
1617 sizeof(lease->address.iabuf))) {
1618 struct iaddr netmask, subnet, broadcast;
1619
1620 memcpy(netmask.iabuf, lease->options[DHO_SUBNET_MASK].data,
1621 lease->options[DHO_SUBNET_MASK].len);
1622 netmask.len = lease->options[DHO_SUBNET_MASK].len;
1623
1624 subnet = subnet_number(lease->address, netmask);
1625 if (subnet.len) {
1626 script_set_env(prefix, "network_number",
1627 piaddr(subnet));
1628 if (!lease->options[DHO_BROADCAST_ADDRESS].len) {
1629 broadcast = broadcast_addr(subnet, netmask);
1630 if (broadcast.len)
1631 script_set_env(prefix,
1632 "broadcast_address",
1633 piaddr(broadcast));
1634 }
1635 }
1636 }
1637
1638 if (lease->filename)
1639 script_set_env(prefix, "filename", lease->filename);
1640 if (lease->server_name)
1641 script_set_env(prefix, "server_name",
1642 lease->server_name);
1643 for (i = 0; i < 256; i++) {
1644 u_int8_t *dp = NULL;
1645
1646 if (config->defaults[i].len) {
1647 if (lease->options[i].len) {
1648 switch (config->default_actions[i]) {
1649 case ACTION_DEFAULT:
1650 dp = lease->options[i].data;
1651 len = lease->options[i].len;
1652 break;
1653 case ACTION_SUPERSEDE:
1654supersede:
1655 dp = config->defaults[i].data;
1656 len = config->defaults[i].len;
1657 break;
1658 case ACTION_PREPEND:
1659 len = config->defaults[i].len +
1660 lease->options[i].len;
1661 if (len > sizeof(dbuf)) {
1662 warning("no space to %s %s",
1663 "prepend option",
1664 dhcp_options[i].name);
1665 goto supersede;
1666 }
1667 dp = dbuf;
1668 memcpy(dp,
1669 config->defaults[i].data,
1670 config->defaults[i].len);
1671 memcpy(dp +
1672 config->defaults[i].len,
1673 lease->options[i].data,
1674 lease->options[i].len);
1675 dp[len] = '\0';
1676 break;
1677 case ACTION_APPEND:
1678 len = config->defaults[i].len +
1679 lease->options[i].len;
1680 if (len > sizeof(dbuf)) {
1681 warning("no space to %s %s",
1682 "append option",
1683 dhcp_options[i].name);
1684 goto supersede;
1685 }
1686 dp = dbuf;
1687 memcpy(dp, lease->options[i].data,
1688 lease->options[i].len);
1689 memcpy(dp + lease->options[i].len,
1690 config->defaults[i].data,
1691 config->defaults[i].len);
1692 dp[len] = '\0';
1693 }
1694 } else {
1695 dp = config->defaults[i].data;
1696 len = config->defaults[i].len;
1697 }
1698 } else if (lease->options[i].len) {
1699 len = lease->options[i].len;
1700 dp = lease->options[i].data;
1701 } else {
1702 len = 0;
1703 }
1704 if (len) {
1705 char name[256];
1706
1707 if (dhcp_option_ev_name(name, sizeof(name),
1708 &dhcp_options[i]))
1709 script_set_env(prefix, name,
1710 pretty_print_option(i, dp, len, 0, 0));
1711 }
1712 }
1713 snprintf(tbuf, sizeof(tbuf), "%d", (int)lease->expiry);
1714 script_set_env(prefix, "expiry", tbuf);
1715}
1716
1717void
1718script_write_params(char *prefix, struct client_lease *lease)
1719{
1720 size_t fn_len = 0, sn_len = 0, pr_len = 0;
1721 struct imsg_hdr hdr;
1722 struct buf *buf;
1723 int i;
1724
1725 if (lease->filename != NULL)
1726 fn_len = strlen(lease->filename);
1727 if (lease->server_name != NULL)
1728 sn_len = strlen(lease->server_name);
1729 if (prefix != NULL)
1730 pr_len = strlen(prefix);
1731
1732 hdr.code = IMSG_SCRIPT_WRITE_PARAMS;
1733 hdr.len = sizeof(hdr) + sizeof(struct client_lease) +
1734 sizeof(size_t) + fn_len + sizeof(size_t) + sn_len +
1735 sizeof(size_t) + pr_len;
1736
1737 for (i = 0; i < 256; i++)
1738 hdr.len += sizeof(int) + lease->options[i].len;
1739
1740 scripttime = time(NULL);
1741
1742 buf = buf_open(hdr.len);
1743
1744 buf_add(buf, &hdr, sizeof(hdr));
1745 buf_add(buf, lease, sizeof(struct client_lease));
1746 buf_add(buf, &fn_len, sizeof(fn_len));
1747 buf_add(buf, lease->filename, fn_len);
1748 buf_add(buf, &sn_len, sizeof(sn_len));
1749 buf_add(buf, lease->server_name, sn_len);
1750 buf_add(buf, &pr_len, sizeof(pr_len));
1751 buf_add(buf, prefix, pr_len);
1752
1753 for (i = 0; i < 256; i++) {
1754 buf_add(buf, &lease->options[i].len,
1755 sizeof(lease->options[i].len));
1756 buf_add(buf, lease->options[i].data,
1757 lease->options[i].len);
1758 }
1759
1760 buf_close(privfd, buf);
1761}
1762
1763int
1764script_go(void)
1765{
1766 struct imsg_hdr hdr;
1767 struct buf *buf;
1768 int ret;
1769
1770 scripttime = time(NULL);
1771
1772 hdr.code = IMSG_SCRIPT_GO;
1773 hdr.len = sizeof(struct imsg_hdr);
1774
1775 buf = buf_open(hdr.len);
1776
1777 buf_add(buf, &hdr, sizeof(hdr));
1778 buf_close(privfd, buf);
1779
1780 bzero(&hdr, sizeof(hdr));
1781 buf_read(privfd, &hdr, sizeof(hdr));
1782 if (hdr.code != IMSG_SCRIPT_GO_RET)
1783 error("unexpected msg type %u", hdr.code);
1784 if (hdr.len != sizeof(hdr) + sizeof(int))
1785 error("received corrupted message");
1786 buf_read(privfd, &ret, sizeof(ret));
1787
1788 return (ret);
1789}
1790
1791int
1792priv_script_go(void)
1793{
1794 char *scriptName, *argv[2], **envp;
1795 int pid, wpid, wstatus;
1796
1797 scripttime = time(NULL);
1798
1799 scriptName = config->script_name;
1800 envp = client->scriptEnv;
1801
1802 argv[0] = scriptName;
1803 argv[1] = NULL;
1804
1805 pid = fork();
1806 if (pid < 0) {
1807 error("fork: %m");
1808 wstatus = 0;
1809 } else if (pid) {
1810 do {
1811 wpid = wait(&wstatus);
1812 } while (wpid != pid && wpid > 0);
1813 if (wpid < 0) {
1814 error("wait: %m");
1815 wstatus = 0;
1816 }
1817 } else {
1818 execve(scriptName, argv, envp);
1819 error("execve (%s, ...): %m", scriptName);
1820 }
1821
1822 script_flush_env();
1823
1824 return (WEXITSTATUS(wstatus));
1825}
1826
1827void
1828script_set_env(const char *prefix, const char *name, const char *value)
1829{
1830 int i, j, namelen;
1831
1832 namelen = strlen(name);
1833
1834 for (i = 0; client->scriptEnv[i]; i++)
1835 if (strncmp(client->scriptEnv[i], name, namelen) == 0 &&
1836 client->scriptEnv[i][namelen] == '=')
1837 break;
1838
1839 if (client->scriptEnv[i])
1840 /* Reuse the slot. */
1841 free(client->scriptEnv[i]);
1842 else {
1843 /* New variable. Expand if necessary. */
1844 if (i >= client->scriptEnvsize - 1) {
1845 char **newscriptEnv;
1846 int newscriptEnvsize = client->scriptEnvsize + 50;
1847
1848 newscriptEnv = realloc(client->scriptEnv,
1849 newscriptEnvsize);
1850 if (newscriptEnv == NULL) {
1851 free(client->scriptEnv);
1852 client->scriptEnv = NULL;
1853 client->scriptEnvsize = 0;
1854 error("script_set_env: no memory for variable");
1855 }
1856 client->scriptEnv = newscriptEnv;
1857 client->scriptEnvsize = newscriptEnvsize;
1858 }
1859 /* need to set the NULL pointer at end of array beyond
1860 the new slot. */
1861 client->scriptEnv[i + 1] = NULL;
1862 }
1863 /* Allocate space and format the variable in the appropriate slot. */
1864 client->scriptEnv[i] = malloc(strlen(prefix) + strlen(name) + 1 +
1865 strlen(value) + 1);
1866 if (client->scriptEnv[i] == NULL)
1867 error("script_set_env: no memory for variable assignment");
1868
1869 /* No `` or $() command substitution allowed in environment values! */
1870 for (j = 0; j < strlen(value); j++)
1871 switch (value[j]) {
1872 case '`':
1873 case '$':
1874 error("illegal character (%c) in value '%s'", value[j],
1875 value);
1876 /* not reached */
1877 }
1878 snprintf(client->scriptEnv[i], strlen(prefix) + strlen(name) +
1879 1 + strlen(value) + 1, "%s%s=%s", prefix, name, value);
1880}
1881
1882void
1883script_flush_env(void)
1884{
1885 int i;
1886
1887 for (i = 0; client->scriptEnv[i]; i++) {
1888 free(client->scriptEnv[i]);
1889 client->scriptEnv[i] = NULL;
1890 }
1891 client->scriptEnvsize = 0;
1892}
1893
1894int
1895dhcp_option_ev_name(char *buf, size_t buflen, const struct option *option)
1896{
1897 size_t i;
1898
1899 for (i = 0; option->name[i]; i++) {
1900 if (i + 1 == buflen)
1901 return 0;
1902 if (option->name[i] == '-')
1903 buf[i] = '_';
1904 else
1905 buf[i] = option->name[i];
1906 }
1907
1908 buf[i] = 0;
1909 return 1;
1910}
1911
1912void
1913go_daemon(void)
1914{
1915 static int state = 0;
1916
1917 if (no_daemon || state)
1918 return;
1919
1920 state = 1;
1921
1922 /* Stop logging to stderr... */
1923 log_perror = 0;
1924
1925 if (daemon(1, 0) == -1)
1926 error("daemon");
1927
1928 /* we are chrooted, daemon(3) fails to open /dev/null */
1929 if (nullfd != -1) {
1930 dup2(nullfd, STDIN_FILENO);
1931 dup2(nullfd, STDOUT_FILENO);
1932 dup2(nullfd, STDERR_FILENO);
1933 close(nullfd);
1934 nullfd = -1;
1935 }
1936}
1937
1938int
1939check_option(struct client_lease *l, int option)
1940{
1941 char *opbuf;
1942 char *sbuf;
1943
1944 /* we use this, since this is what gets passed to dhclient-script */
1945
1946 opbuf = pretty_print_option(option, l->options[option].data,
1947 l->options[option].len, 0, 0);
1948
1949 sbuf = option_as_string(option, l->options[option].data,
1950 l->options[option].len);
1951
1952 switch (option) {
1953 case DHO_SUBNET_MASK:
1954 case DHO_TIME_SERVERS:
1955 case DHO_NAME_SERVERS:
1956 case DHO_ROUTERS:
1957 case DHO_DOMAIN_NAME_SERVERS:
1958 case DHO_LOG_SERVERS:
1959 case DHO_COOKIE_SERVERS:
1960 case DHO_LPR_SERVERS:
1961 case DHO_IMPRESS_SERVERS:
1962 case DHO_RESOURCE_LOCATION_SERVERS:
1963 case DHO_SWAP_SERVER:
1964 case DHO_BROADCAST_ADDRESS:
1965 case DHO_NIS_SERVERS:
1966 case DHO_NTP_SERVERS:
1967 case DHO_NETBIOS_NAME_SERVERS:
1968 case DHO_NETBIOS_DD_SERVER:
1969 case DHO_FONT_SERVERS:
1970 case DHO_DHCP_SERVER_IDENTIFIER:
1971 if (!ipv4addrs(opbuf)) {
1972 warning("Invalid IP address in option: %s", opbuf);
1973 return (0);
1974 }
1975 return (1);
1976 case DHO_HOST_NAME:
1977 case DHO_DOMAIN_NAME:
1978 case DHO_NIS_DOMAIN:
1979 if (!res_hnok(sbuf)) {
1980 warning("Bogus Host Name option %d: %s (%s)", option,
1981 sbuf, opbuf);
1982 l->options[option].len = 0;
1983 free(l->options[option].data);
1984 }
1985 return (1);
1986 case DHO_PAD:
1987 case DHO_TIME_OFFSET:
1988 case DHO_BOOT_SIZE:
1989 case DHO_MERIT_DUMP:
1990 case DHO_ROOT_PATH:
1991 case DHO_EXTENSIONS_PATH:
1992 case DHO_IP_FORWARDING:
1993 case DHO_NON_LOCAL_SOURCE_ROUTING:
1994 case DHO_POLICY_FILTER:
1995 case DHO_MAX_DGRAM_REASSEMBLY:
1996 case DHO_DEFAULT_IP_TTL:
1997 case DHO_PATH_MTU_AGING_TIMEOUT:
1998 case DHO_PATH_MTU_PLATEAU_TABLE:
1999 case DHO_INTERFACE_MTU:
2000 case DHO_ALL_SUBNETS_LOCAL:
2001 case DHO_PERFORM_MASK_DISCOVERY:
2002 case DHO_MASK_SUPPLIER:
2003 case DHO_ROUTER_DISCOVERY:
2004 case DHO_ROUTER_SOLICITATION_ADDRESS:
2005 case DHO_STATIC_ROUTES:
2006 case DHO_TRAILER_ENCAPSULATION:
2007 case DHO_ARP_CACHE_TIMEOUT:
2008 case DHO_IEEE802_3_ENCAPSULATION:
2009 case DHO_DEFAULT_TCP_TTL:
2010 case DHO_TCP_KEEPALIVE_INTERVAL:
2011 case DHO_TCP_KEEPALIVE_GARBAGE:
2012 case DHO_VENDOR_ENCAPSULATED_OPTIONS:
2013 case DHO_NETBIOS_NODE_TYPE:
2014 case DHO_NETBIOS_SCOPE:
2015 case DHO_X_DISPLAY_MANAGER:
2016 case DHO_DHCP_REQUESTED_ADDRESS:
2017 case DHO_DHCP_LEASE_TIME:
2018 case DHO_DHCP_OPTION_OVERLOAD:
2019 case DHO_DHCP_MESSAGE_TYPE:
2020 case DHO_DHCP_PARAMETER_REQUEST_LIST:
2021 case DHO_DHCP_MESSAGE:
2022 case DHO_DHCP_MAX_MESSAGE_SIZE:
2023 case DHO_DHCP_RENEWAL_TIME:
2024 case DHO_DHCP_REBINDING_TIME:
2025 case DHO_DHCP_CLASS_IDENTIFIER:
2026 case DHO_DHCP_CLIENT_IDENTIFIER:
2027 case DHO_DHCP_USER_CLASS_ID:
2028 case DHO_END:
2029 return (1);
2030 default:
2031 warning("unknown dhcp option value 0x%x", option);
2032 return (unknown_ok);
2033 }
2034}
2035
2036int
2037res_hnok(const char *name)
2038{
2039 const char *dn = name;
2040 int pch = '.', ch = *dn++;
2041 int warn = 0;
2042
2043 while (ch != '\0') {
2044 int nch = *dn++;
2045
2046 if (ch == '.') {
2047 ;
2048 } else if (pch == '.' || nch == '.' || nch == '\0') {
2049 if (!isalnum(ch))
2050 return (0);
2051 } else if (!isalnum(ch) && ch != '-' && ch != '_')
2052 return (0);
2053 else if (ch == '_' && warn == 0) {
2054 warning("warning: hostname %s contains an "
2055 "underscore which violates RFC 952", name);
2056 warn++;
2057 }
2058 pch = ch, ch = nch;
2059 }
2060 return (1);
2061}
2062
2063/* Does buf consist only of dotted decimal ipv4 addrs?
2064 * return how many if so,
2065 * otherwise, return 0
2066 */
2067int
2068ipv4addrs(char * buf)
2069{
2070 struct in_addr jnk;
2071 int count = 0;
2072
2073 while (inet_aton(buf, &jnk) == 1){
2074 count++;
2075 while (*buf == '.' || isdigit(*buf))
2076 buf++;
2077 if (*buf == '\0')
2078 return (count);
2079 while (*buf == ' ')
2080 buf++;
2081 }
2082 return (0);
2083}
2084
2085char *
2086option_as_string(unsigned int code, unsigned char *data, int len)
2087{
2088 static char optbuf[32768]; /* XXX */
2089 char *op = optbuf;
2090 int opleft = sizeof(optbuf);
2091 unsigned char *dp = data;
2092
2093 if (code > 255)
2094 error("option_as_string: bad code %d", code);
2095
2096 for (; dp < data + len; dp++) {
2097 if (!isascii(*dp) || !isprint(*dp)) {
2098 if (dp + 1 != data + len || *dp != 0) {
2099 size_t oplen;
2100 snprintf(op, opleft, "\\%03o", *dp);
2101 oplen = strlen(op);
2102 op += oplen;
2103 opleft -= oplen;
2104 }
2105 } else if (*dp == '"' || *dp == '\'' || *dp == '$' ||
2106 *dp == '`' || *dp == '\\') {
2107 *op++ = '\\';
2108 *op++ = *dp;
2109 opleft -= 2;
2110 } else {
2111 *op++ = *dp;
2112 opleft--;
2113 }
2114 }
2115 if (opleft < 1)
2116 goto toobig;
2117 *op = 0;
2118 return optbuf;
2119toobig:
2120 warning("dhcp option too large");
2121 return "<error>";
2122}
2123
2124int
2125fork_privchld(int fd, int fd2)
2126{
2127 struct pollfd pfd[1];
a05d48e6 2128 int nfds, pfail = 0;
846204b6
HT
2129
2130 switch (fork()) {
2131 case -1:
2132 error("cannot fork");
2133 break;
2134 case 0:
2135 break;
2136 default:
2137 return (0);
2138 }
2139
2140 if (chdir("/") == -1)
2141 error("chdir(\"/\")");
2142
2143 setproctitle("%s [priv]", ifi->name);
2144
2145 dup2(nullfd, STDIN_FILENO);
2146 dup2(nullfd, STDOUT_FILENO);
2147 dup2(nullfd, STDERR_FILENO);
2148 close(nullfd);
2149 close(fd2);
2150
2151 for (;;) {
2152 pfd[0].fd = fd;
2153 pfd[0].events = POLLIN;
2154 if ((nfds = poll(pfd, 1, INFTIM)) == -1)
2155 if (errno != EINTR)
2156 error("poll error");
2157
a05d48e6
SG
2158 /*
2159 * Handle temporary errors, but bail if they persist.
2160 */
2161 if (nfds == 0 || !(pfd[0].revents & POLLIN)) {
2162 if (pfail > POLL_FAILURES)
2163 error("poll failed > %d times", POLL_FAILURES);
2164 sleep(pfail * POLL_FAILURE_WAIT);
2165 pfail++;
846204b6 2166 continue;
a05d48e6 2167 }
846204b6
HT
2168
2169 dispatch_imsg(fd);
2170 }
2171}