dhclient - Error out if _dhcp user is missing.
[dragonfly.git] / sbin / dhclient / dhclient.c
CommitLineData
38623c79 1/* $OpenBSD: src/sbin/dhclient/dhclient.c,v 1.126 2009/05/20 20:37:43 thib Exp $ */
846204b6
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2
3/*
4 * Copyright 2004 Henning Brauer <henning@openbsd.org>
5 * Copyright (c) 1995, 1996, 1997, 1998, 1999
6 * The Internet Software Consortium. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of The Internet Software Consortium nor the names
18 * of its contributors may be used to endorse or promote products derived
19 * from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
22 * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
23 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
25 * DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
26 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
27 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
28 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
29 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
30 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
31 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
32 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * This software has been written for the Internet Software Consortium
36 * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
37 * Enterprises. To learn more about the Internet Software Consortium,
38 * see ``http://www.vix.com/isc''. To learn more about Vixie
39 * Enterprises, see ``http://www.vix.com''.
40 *
41 * This client was substantially modified and enhanced by Elliot Poger
42 * for use on Linux while he was working on the MosquitoNet project at
43 * Stanford.
44 *
45 * The current version owes much to Elliot's Linux enhancements, but
46 * was substantially reorganized and partially rewritten by Ted Lemon
47 * so as to use the same networking framework that the Internet Software
48 * Consortium DHCP server uses. Much system-specific configuration code
49 * was moved into a shell script so that as support for more operating
50 * systems is added, it will not be necessary to port and maintain
51 * system-specific configuration code to these operating systems - instead,
52 * the shell script can invoke the native tools to accomplish the same
53 * purpose.
54 */
55
56#include <ctype.h>
57#include <poll.h>
58#include <pwd.h>
a05d48e6 59#include <unistd.h>
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60
61#include "dhcpd.h"
62#include "privsep.h"
63
64#define CLIENT_PATH "PATH=/usr/bin:/usr/sbin:/bin:/sbin"
65#define DEFAULT_LEASE_TIME 43200 /* 12 hours... */
66#define TIME_MAX 2147483647
a05d48e6
SG
67#define POLL_FAILURES 10
68#define POLL_FAILURE_WAIT 1 /* Back off multiplier (seconds) */
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69
70time_t cur_time;
71
72char *path_dhclient_conf = _PATH_DHCLIENT_CONF;
73char *path_dhclient_db = NULL;
74
75int log_perror = 1;
76int privfd;
77int nullfd = -1;
78int no_daemon;
79int unknown_ok = 1;
80int routefd = -1;
81
82struct iaddr iaddr_broadcast = { 4, { 255, 255, 255, 255 } };
83struct in_addr inaddr_any;
84struct sockaddr_in sockaddr_broadcast;
85
86struct interface_info *ifi;
87struct client_state *client;
88struct client_config *config;
89
90int findproto(char *, int);
91struct sockaddr *get_ifa(char *, int);
92void usage(void);
93int check_option(struct client_lease *l, int option);
94int ipv4addrs(char * buf);
95int res_hnok(const char *dn);
96char *option_as_string(unsigned int code, unsigned char *data, int len);
97int fork_privchld(int, int);
98
99#define ROUNDUP(a) \
100 ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
101#define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))
102
103time_t scripttime;
104static FILE *leaseFile;
105
106int
107findproto(char *cp, int n)
108{
109 struct sockaddr *sa;
110 int i;
111
112 if (n == 0)
113 return -1;
114 for (i = 1; i; i <<= 1) {
115 if (i & n) {
116 sa = (struct sockaddr *)cp;
117 switch (i) {
118 case RTA_IFA:
119 case RTA_DST:
120 case RTA_GATEWAY:
121 case RTA_NETMASK:
122 if (sa->sa_family == AF_INET)
123 return AF_INET;
124 if (sa->sa_family == AF_INET6)
125 return AF_INET6;
126 break;
127 case RTA_IFP:
128 break;
129 }
130 ADVANCE(cp, sa);
131 }
132 }
133 return (-1);
134}
135
136struct sockaddr *
137get_ifa(char *cp, int n)
138{
139 struct sockaddr *sa;
140 int i;
141
142 if (n == 0)
143 return (NULL);
144 for (i = 1; i; i <<= 1)
145 if (i & n) {
146 sa = (struct sockaddr *)cp;
147 if (i == RTA_IFA)
148 return (sa);
149 ADVANCE(cp, sa);
150 }
151
152 return (NULL);
153}
be18cf74 154struct iaddr defaddr = { .len = 4 }; /* NULL is for silence warnings */
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155
156/* ARGSUSED */
157void
158routehandler(void)
159{
160 int linkstat;
161 char msg[2048];
162 struct rt_msghdr *rtm;
163 struct if_msghdr *ifm;
164 struct ifa_msghdr *ifam;
165 struct if_announcemsghdr *ifan;
166 struct client_lease *l;
167 time_t t = time(NULL);
168 struct sockaddr *sa;
169 struct iaddr a;
170 ssize_t n;
171
172 do {
173 n = read(routefd, &msg, sizeof(msg));
174 } while (n == -1 && errno == EINTR);
175
176 rtm = (struct rt_msghdr *)msg;
177 if (n < sizeof(rtm->rtm_msglen) || n < rtm->rtm_msglen ||
178 rtm->rtm_version != RTM_VERSION)
179 return;
180
181 switch (rtm->rtm_type) {
182 case RTM_NEWADDR:
183 ifam = (struct ifa_msghdr *)rtm;
184 if (ifam->ifam_index != ifi->index)
185 break;
186 if (findproto((char *)(ifam + 1), ifam->ifam_addrs) != AF_INET)
187 break;
188 sa = get_ifa((char *)(ifam + 1), ifam->ifam_addrs);
189 if (sa == NULL)
190 goto die;
191
192 if ((a.len = sizeof(struct in_addr)) > sizeof(a.iabuf))
193 error("king bula sez: len mismatch");
194 memcpy(a.iabuf, &((struct sockaddr_in *)sa)->sin_addr, a.len);
195 if (addr_eq(a, defaddr))
196 break;
197
198 for (l = client->active; l != NULL; l = l->next)
199 if (addr_eq(a, l->address))
200 break;
201
202 if (l != NULL || (client->alias &&
203 addr_eq(a, client->alias->address)))
204 /* new addr is the one we set */
205 break;
206
207 goto die;
208 case RTM_DELADDR:
209 ifam = (struct ifa_msghdr *)rtm;
210 if (ifam->ifam_index != ifi->index)
211 break;
212 if (findproto((char *)(ifam + 1), ifam->ifam_addrs) != AF_INET)
213 break;
214 if (scripttime == 0 || t < scripttime + 10)
215 break;
216 goto die;
217 case RTM_IFINFO:
218 ifm = (struct if_msghdr *)rtm;
219 if (ifm->ifm_index != ifi->index)
220 break;
221 if ((rtm->rtm_flags & RTF_UP) == 0)
222 goto die;
223
224 linkstat =
225 LINK_STATE_IS_UP(ifm->ifm_data.ifi_link_state) ? 1 : 0;
226 if (linkstat != ifi->linkstat) {
227 debug("link state %s -> %s",
228 ifi->linkstat ? "up" : "down",
229 linkstat ? "up" : "down");
230 ifi->linkstat = interface_link_status(ifi->name);
231 if (ifi->linkstat) {
232 client->state = S_INIT;
233 state_reboot();
234 }
235 }
236 break;
237 case RTM_IFANNOUNCE:
238 ifan = (struct if_announcemsghdr *)rtm;
239 if (ifan->ifan_what == IFAN_DEPARTURE &&
240 ifan->ifan_index == ifi->index)
241 goto die;
242 break;
243 default:
244 break;
245 }
246 return;
247
248die:
249 script_init("FAIL", NULL);
250 if (client->alias)
251 script_write_params("alias_", client->alias);
252 script_go();
253 exit(1);
254}
255
256int
257main(int argc, char *argv[])
258{
259 int ch, fd, quiet = 0, i = 0, pipe_fd[2];
260 struct passwd *pw;
261
262 /* Initially, log errors to stderr as well as to syslogd. */
263 openlog(getprogname(), LOG_PID | LOG_NDELAY, DHCPD_LOG_FACILITY);
264 setlogmask(LOG_UPTO(LOG_INFO));
265
266 while ((ch = getopt(argc, argv, "c:dl:qu")) != -1)
267 switch (ch) {
268 case 'c':
269 path_dhclient_conf = optarg;
270 break;
271 case 'd':
272 no_daemon = 1;
273 break;
274 case 'l':
275 path_dhclient_db = optarg;
276 break;
277 case 'q':
278 quiet = 1;
279 break;
280 case 'u':
281 unknown_ok = 0;
282 break;
283 default:
284 usage();
285 }
286
287 argc -= optind;
288 argv += optind;
289
290 if (argc != 1)
291 usage();
292
293 ifi = calloc(1, sizeof(*ifi));
294 if (ifi == NULL)
295 error("ifi calloc");
296 client = calloc(1, sizeof(*client));
297 if (client == NULL)
298 error("client calloc");
299 config = calloc(1, sizeof(*config));
300 if (config == NULL)
301 error("config calloc");
302
303 if (strlcpy(ifi->name, argv[0], IFNAMSIZ) >= IFNAMSIZ)
304 error("Interface name too long");
305 if (path_dhclient_db == NULL && asprintf(&path_dhclient_db, "%s.%s",
306 _PATH_DHCLIENT_DB, ifi->name) == -1)
307 error("asprintf");
308
309 if (quiet)
310 log_perror = 0;
311
312 tzset();
313 time(&cur_time);
314
315 memset(&sockaddr_broadcast, 0, sizeof(sockaddr_broadcast));
316 sockaddr_broadcast.sin_family = AF_INET;
317 sockaddr_broadcast.sin_port = htons(REMOTE_PORT);
318 sockaddr_broadcast.sin_addr.s_addr = INADDR_BROADCAST;
319 sockaddr_broadcast.sin_len = sizeof(sockaddr_broadcast);
320 inaddr_any.s_addr = INADDR_ANY;
321
322 read_client_conf();
323
324 if (interface_status(ifi->name) == 0) {
325 interface_link_forceup(ifi->name);
326 /* Give it up to 4 seconds of silent grace to find link */
327 i = -4;
328 } else
329 i = 0;
330
331 while (!(ifi->linkstat = interface_link_status(ifi->name))) {
332 if (i == 0)
333 fprintf(stderr, "%s: no link ...", ifi->name);
334 else if (i > 0)
335 fprintf(stderr, ".");
336 fflush(stderr);
337 if (++i > config->link_timeout) {
338 fprintf(stderr, " sleeping\n");
339 goto dispatch;
340 }
341 sleep(1);
846204b6 342 }
ade429c6 343 if (i > 0)
77a69a5f 344 fprintf(stderr, " got link\n");
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345
346 dispatch:
347 if ((nullfd = open(_PATH_DEVNULL, O_RDWR, 0)) == -1)
348 error("cannot open %s: %m", _PATH_DEVNULL);
349
38623c79
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350 if ((pw = getpwnam("_dhcp")) == NULL)
351 error("no such user: _dhcp");
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352
353 if (pipe(pipe_fd) == -1)
354 error("pipe");
355
356 fork_privchld(pipe_fd[0], pipe_fd[1]);
357
358 close(pipe_fd[0]);
359 privfd = pipe_fd[1];
360
361 if ((fd = open(path_dhclient_db, O_RDONLY|O_EXLOCK|O_CREAT, 0)) == -1)
362 error("can't open and lock %s: %m", path_dhclient_db);
363 read_client_leases();
364 if ((leaseFile = fopen(path_dhclient_db, "w")) == NULL)
365 error("can't open %s: %m", path_dhclient_db);
366 rewrite_client_leases();
367 close(fd);
368
369 priv_script_init("PREINIT", NULL);
370 if (client->alias)
371 priv_script_write_params("alias_", client->alias);
372 priv_script_go();
373
374 if ((routefd = socket(PF_ROUTE, SOCK_RAW, 0)) == -1)
375 error("socket(PF_ROUTE, SOCK_RAW): %m");
376
377 /* set up the interface */
378 discover_interface();
379
380 if (chroot(_PATH_VAREMPTY) == -1)
381 error("chroot");
382 if (chdir("/") == -1)
383 error("chdir(\"/\")");
384
385 if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1)
386 error("setresgid");
387 if (setgroups(1, &pw->pw_gid) == -1)
388 error("setgroups");
389 if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1)
390 error("setresuid");
391
392 endpwent();
393
394 setproctitle("%s", ifi->name);
395
396 if (ifi->linkstat) {
397 client->state = S_INIT;
398 state_reboot();
399 } else
400 go_daemon();
401
402 dispatch();
403
404 /* not reached */
405 return (0);
406}
407
408void
409usage(void)
410{
411 fprintf(stderr, "usage: %s [-dqu] [-c file] [-l file] interface\n",
412 getprogname());
413 exit(1);
414}
415
416/*
417 * Individual States:
418 *
419 * Each routine is called from the dhclient_state_machine() in one of
420 * these conditions:
421 * -> entering INIT state
422 * -> recvpacket_flag == 0: timeout in this state
423 * -> otherwise: received a packet in this state
424 *
425 * Return conditions as handled by dhclient_state_machine():
426 * Returns 1, sendpacket_flag = 1: send packet, reset timer.
427 * Returns 1, sendpacket_flag = 0: just reset the timer (wait for a milestone).
428 * Returns 0: finish the nap which was interrupted for no good reason.
429 *
430 * Several per-interface variables are used to keep track of the process:
431 * active_lease: the lease that is being used on the interface
432 * (null pointer if not configured yet).
433 * offered_leases: leases corresponding to DHCPOFFER messages that have
434 * been sent to us by DHCP servers.
435 * acked_leases: leases corresponding to DHCPACK messages that have been
436 * sent to us by DHCP servers.
437 * sendpacket: DHCP packet we're trying to send.
438 * destination: IP address to send sendpacket to
439 * In addition, there are several relevant per-lease variables.
440 * T1_expiry, T2_expiry, lease_expiry: lease milestones
441 * In the active lease, these control the process of renewing the lease;
442 * In leases on the acked_leases list, this simply determines when we
443 * can no longer legitimately use the lease.
444 */
445void
446state_reboot(void)
447{
448 /* If we don't remember an active lease, go straight to INIT. */
449 if (!client->active || client->active->is_bootp) {
450 state_init();
451 return;
452 }
453
454 /* We are in the rebooting state. */
455 client->state = S_REBOOTING;
456
457 /* make_request doesn't initialize xid because it normally comes
458 from the DHCPDISCOVER, but we haven't sent a DHCPDISCOVER,
459 so pick an xid now. */
460 client->xid = arc4random();
461
462 /* Make a DHCPREQUEST packet, and set appropriate per-interface
463 flags. */
464 make_request(client->active);
465 client->destination = iaddr_broadcast;
466 client->first_sending = cur_time;
467 client->interval = config->initial_interval;
468
469 /* Zap the medium list... */
470 client->medium = NULL;
471
472 /* Send out the first DHCPREQUEST packet. */
473 send_request();
474}
475
476/*
477 * Called when a lease has completely expired and we've
478 * been unable to renew it.
479 */
480void
481state_init(void)
482{
483 /* Make a DHCPDISCOVER packet, and set appropriate per-interface
484 flags. */
485 make_discover(client->active);
486 client->xid = client->packet.xid;
487 client->destination = iaddr_broadcast;
488 client->state = S_SELECTING;
489 client->first_sending = cur_time;
490 client->interval = config->initial_interval;
491
492 /* Add an immediate timeout to cause the first DHCPDISCOVER packet
493 to go out. */
494 send_discover();
495}
496
497/*
498 * state_selecting is called when one or more DHCPOFFER packets
499 * have been received and a configurable period of time has passed.
500 */
501void
502state_selecting(void)
503{
504 struct client_lease *lp, *next, *picked;
505
506 /* Cancel state_selecting and send_discover timeouts, since either
507 one could have got us here. */
508 cancel_timeout(state_selecting);
509 cancel_timeout(send_discover);
510
511 /* We have received one or more DHCPOFFER packets. Currently,
512 the only criterion by which we judge leases is whether or
513 not we get a response when we arp for them. */
514 picked = NULL;
515 for (lp = client->offered_leases; lp; lp = next) {
516 next = lp->next;
517
518 /* Check to see if we got an ARPREPLY for the address
519 in this particular lease. */
520 if (!picked) {
521 script_init("ARPCHECK", lp->medium);
522 script_write_params("check_", lp);
523
524 /* If the ARPCHECK code detects another
525 machine using the offered address, it exits
526 nonzero. We need to send a DHCPDECLINE and
527 toss the lease. */
528 if (script_go()) {
529 make_decline(lp);
530 send_decline();
531 goto freeit;
532 }
533 picked = lp;
534 picked->next = NULL;
535 } else {
536freeit:
537 free_client_lease(lp);
538 }
539 }
540 client->offered_leases = NULL;
541
542 /* If we just tossed all the leases we were offered, go back
543 to square one. */
544 if (!picked) {
545 client->state = S_INIT;
546 state_init();
547 return;
548 }
549
550 /* If it was a BOOTREPLY, we can just take the address right now. */
551 if (!picked->options[DHO_DHCP_MESSAGE_TYPE].len) {
552 client->new = picked;
553
554 /* Make up some lease expiry times
555 XXX these should be configurable. */
556 client->new->expiry = cur_time + 12000;
557 client->new->renewal += cur_time + 8000;
558 client->new->rebind += cur_time + 10000;
559
560 client->state = S_REQUESTING;
561
562 /* Bind to the address we received. */
563 bind_lease();
564 return;
565 }
566
567 /* Go to the REQUESTING state. */
568 client->destination = iaddr_broadcast;
569 client->state = S_REQUESTING;
570 client->first_sending = cur_time;
571 client->interval = config->initial_interval;
572
573 /* Make a DHCPREQUEST packet from the lease we picked. */
574 make_request(picked);
575 client->xid = client->packet.xid;
576
577 /* Toss the lease we picked - we'll get it back in a DHCPACK. */
578 free_client_lease(picked);
579
580 /* Add an immediate timeout to send the first DHCPREQUEST packet. */
581 send_request();
582}
583
584void
585dhcpack(struct iaddr client_addr, struct option_data *options)
586{
587 struct client_lease *lease;
588
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589
590 if (client->state != S_REBOOTING &&
591 client->state != S_REQUESTING &&
592 client->state != S_RENEWING &&
593 client->state != S_REBINDING)
594 return;
595
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596
597 lease = packet_to_lease(options);
598 if (!lease) {
599 note("packet_to_lease failed.");
600 return;
601 }
602
603 client->new = lease;
604
605 /* Stop resending DHCPREQUEST. */
606 cancel_timeout(send_request);
607
608 /* Figure out the lease time. */
609 if (client->new->options[DHO_DHCP_LEASE_TIME].data)
610 client->new->expiry =
611 getULong(client->new->options[DHO_DHCP_LEASE_TIME].data);
612 else
613 client->new->expiry = DEFAULT_LEASE_TIME;
614 /* A number that looks negative here is really just very large,
615 because the lease expiry offset is unsigned. */
616 if (client->new->expiry < 0)
617 client->new->expiry = TIME_MAX;
618 /* XXX should be fixed by resetting the client state */
619 if (client->new->expiry < 60)
620 client->new->expiry = 60;
621
622 /* Take the server-provided renewal time if there is one;
623 otherwise figure it out according to the spec. */
624 if (client->new->options[DHO_DHCP_RENEWAL_TIME].len)
625 client->new->renewal =
626 getULong(client->new->options[DHO_DHCP_RENEWAL_TIME].data);
627 else
628 client->new->renewal = client->new->expiry / 2;
629
630 /* Same deal with the rebind time. */
631 if (client->new->options[DHO_DHCP_REBINDING_TIME].len)
632 client->new->rebind =
633 getULong(client->new->options[DHO_DHCP_REBINDING_TIME].data);
634 else
635 client->new->rebind = client->new->renewal +
636 client->new->renewal / 2 + client->new->renewal / 4;
637
638 client->new->expiry += cur_time;
639 /* Lease lengths can never be negative. */
640 if (client->new->expiry < cur_time)
641 client->new->expiry = TIME_MAX;
642 client->new->renewal += cur_time;
643 if (client->new->renewal < cur_time)
644 client->new->renewal = TIME_MAX;
645 client->new->rebind += cur_time;
646 if (client->new->rebind < cur_time)
647 client->new->rebind = TIME_MAX;
648
649 bind_lease();
650}
651
652void
653bind_lease(void)
654{
655 /* Remember the medium. */
656 client->new->medium = client->medium;
657
658 /* Write out the new lease. */
659 write_client_lease(client->new, 0);
660
661 /* Run the client script with the new parameters. */
662 script_init((client->state == S_REQUESTING ? "BOUND" :
663 (client->state == S_RENEWING ? "RENEW" :
664 (client->state == S_REBOOTING ? "REBOOT" : "REBIND"))),
665 client->new->medium);
666 if (client->active && client->state != S_REBOOTING)
667 script_write_params("old_", client->active);
668 script_write_params("new_", client->new);
669 if (client->alias)
670 script_write_params("alias_", client->alias);
671 script_go();
672
673 /* Replace the old active lease with the new one. */
674 if (client->active)
675 free_client_lease(client->active);
676 client->active = client->new;
677 client->new = NULL;
678
679 /* Set up a timeout to start the renewal process. */
680 add_timeout(client->active->renewal, state_bound);
681
682 note("bound to %s -- renewal in %ld seconds.",
683 piaddr(client->active->address),
684 client->active->renewal - cur_time);
685 client->state = S_BOUND;
686 reinitialize_interface();
687 go_daemon();
688}
689
690/*
691 * state_bound is called when we've successfully bound to a particular
692 * lease, but the renewal time on that lease has expired. We are
693 * expected to unicast a DHCPREQUEST to the server that gave us our
694 * original lease.
695 */
696void
697state_bound(void)
698{
699 /* T1 has expired. */
700 make_request(client->active);
701 client->xid = client->packet.xid;
702
703 if (client->active->options[DHO_DHCP_SERVER_IDENTIFIER].len == 4) {
704 memcpy(client->destination.iabuf,
705 client->active->options[DHO_DHCP_SERVER_IDENTIFIER].data,
706 4);
707 client->destination.len = 4;
708 } else
709 client->destination = iaddr_broadcast;
710
711 client->first_sending = cur_time;
712 client->interval = config->initial_interval;
713 client->state = S_RENEWING;
714
715 /* Send the first packet immediately. */
716 send_request();
717}
718
719void
720dhcpoffer(struct iaddr client_addr, struct option_data *options)
721{
722 struct client_lease *lease, *lp;
723 int i;
724 int arp_timeout_needed, stop_selecting;
725 char *name = options[DHO_DHCP_MESSAGE_TYPE].len ? "DHCPOFFER" :
726 "BOOTREPLY";
727
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728
729 if (client->state != S_SELECTING)
730 return;
731
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732
733 /* If this lease doesn't supply the minimum required parameters,
734 blow it off. */
735 for (i = 0; config->required_options[i]; i++) {
736 if (!options[config->required_options[i]].len) {
737 note("%s isn't satisfactory.", name);
738 return;
739 }
740 }
741
742 /* If we've already seen this lease, don't record it again. */
743 for (lease = client->offered_leases;
744 lease; lease = lease->next) {
745 if (lease->address.len == sizeof(client->packet.yiaddr) &&
746 !memcmp(lease->address.iabuf,
747 &client->packet.yiaddr, lease->address.len)) {
748 debug("%s already seen.", name);
749 return;
750 }
751 }
752
753 lease = packet_to_lease(options);
754 if (!lease) {
755 note("packet_to_lease failed.");
756 return;
757 }
758
759 /* If this lease was acquired through a BOOTREPLY, record that
760 fact. */
761 if (!options[DHO_DHCP_MESSAGE_TYPE].len)
762 lease->is_bootp = 1;
763
764 /* Record the medium under which this lease was offered. */
765 lease->medium = client->medium;
766
767 /* Send out an ARP Request for the offered IP address. */
768 script_init("ARPSEND", lease->medium);
769 script_write_params("check_", lease);
770 /* If the script can't send an ARP request without waiting,
771 we'll be waiting when we do the ARPCHECK, so don't wait now. */
772 if (script_go())
773 arp_timeout_needed = 0;
774 else
775 arp_timeout_needed = 2;
776
777 /* Figure out when we're supposed to stop selecting. */
778 stop_selecting = client->first_sending + config->select_interval;
779
780 /* If this is the lease we asked for, put it at the head of the
781 list, and don't mess with the arp request timeout. */
782 if (lease->address.len == client->requested_address.len &&
783 !memcmp(lease->address.iabuf,
784 client->requested_address.iabuf,
785 client->requested_address.len)) {
786 lease->next = client->offered_leases;
787 client->offered_leases = lease;
788 } else {
789 /* If we already have an offer, and arping for this
790 offer would take us past the selection timeout,
791 then don't extend the timeout - just hope for the
792 best. */
793 if (client->offered_leases &&
794 (cur_time + arp_timeout_needed) > stop_selecting)
795 arp_timeout_needed = 0;
796
797 /* Put the lease at the end of the list. */
798 lease->next = NULL;
799 if (!client->offered_leases)
800 client->offered_leases = lease;
801 else {
802 for (lp = client->offered_leases; lp->next;
803 lp = lp->next)
804 ; /* nothing */
805 lp->next = lease;
806 }
807 }
808
809 /* If we're supposed to stop selecting before we've had time
810 to wait for the ARPREPLY, add some delay to wait for
811 the ARPREPLY. */
812 if (stop_selecting - cur_time < arp_timeout_needed)
813 stop_selecting = cur_time + arp_timeout_needed;
814
815 /* If the selecting interval has expired, go immediately to
816 state_selecting(). Otherwise, time out into
817 state_selecting at the select interval. */
818 if (stop_selecting <= 0)
819 state_selecting();
820 else {
821 add_timeout(stop_selecting, state_selecting);
822 cancel_timeout(send_discover);
823 }
824}
825
826/*
827 * Allocate a client_lease structure and initialize it from the
828 * parameters in the specified packet.
829 */
830struct client_lease *
831packet_to_lease(struct option_data *options)
832{
833 struct client_lease *lease;
834 int i;
835
836 lease = malloc(sizeof(struct client_lease));
837
838 if (!lease) {
839 warning("dhcpoffer: no memory to record lease.");
840 return (NULL);
841 }
842
843 memset(lease, 0, sizeof(*lease));
844
845 /* Copy the lease options. */
846 for (i = 0; i < 256; i++) {
847 if (options[i].len) {
848 lease->options[i] = options[i];
849 options[i].data = NULL;
850 options[i].len = 0;
851 if (!check_option(lease, i)) {
852 warning("Invalid lease option - ignoring offer");
853 free_client_lease(lease);
854 return (NULL);
855 }
856 }
857 }
858
859 lease->address.len = sizeof(client->packet.yiaddr);
860 memcpy(lease->address.iabuf, &client->packet.yiaddr,
861 lease->address.len);
862
863 /* If the server name was filled out, copy it. */
864 if ((!lease->options[DHO_DHCP_OPTION_OVERLOAD].len ||
865 !(lease->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 2)) &&
866 client->packet.sname[0]) {
867 lease->server_name = malloc(DHCP_SNAME_LEN + 1);
868 if (!lease->server_name) {
869 warning("dhcpoffer: no memory for server name.");
870 free_client_lease(lease);
871 return (NULL);
872 }
873 memcpy(lease->server_name, client->packet.sname,
874 DHCP_SNAME_LEN);
875 lease->server_name[DHCP_SNAME_LEN] = '\0';
876 if (!res_hnok(lease->server_name)) {
877 warning("Bogus server name %s", lease->server_name);
878 free(lease->server_name);
879 lease->server_name = NULL;
880 }
881 }
882
883 /* Ditto for the filename. */
884 if ((!lease->options[DHO_DHCP_OPTION_OVERLOAD].len ||
885 !(lease->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 1)) &&
886 client->packet.file[0]) {
887 /* Don't count on the NUL terminator. */
888 lease->filename = malloc(DHCP_FILE_LEN + 1);
889 if (!lease->filename) {
890 warning("dhcpoffer: no memory for filename.");
891 free_client_lease(lease);
892 return (NULL);
893 }
894 memcpy(lease->filename, client->packet.file, DHCP_FILE_LEN);
895 lease->filename[DHCP_FILE_LEN] = '\0';
896 }
897 return lease;
898}
899
900void
901dhcpnak(struct iaddr client_addr, struct option_data *options)
902{
846204b6
HT
903
904 if (client->state != S_REBOOTING &&
905 client->state != S_REQUESTING &&
906 client->state != S_RENEWING &&
907 client->state != S_REBINDING)
908 return;
909
846204b6
HT
910
911 if (!client->active) {
912 note("DHCPNAK with no active lease.");
913 return;
914 }
915
916 free_client_lease(client->active);
917 client->active = NULL;
918
919 /* Stop sending DHCPREQUEST packets... */
920 cancel_timeout(send_request);
921
922 client->state = S_INIT;
923 state_init();
924}
925
926/*
927 * Send out a DHCPDISCOVER packet, and set a timeout to send out another
928 * one after the right interval has expired. If we don't get an offer by
929 * the time we reach the panic interval, call the panic function.
930 */
931void
932send_discover(void)
933{
934 int interval, increase = 1;
935
936 /* Figure out how long it's been since we started transmitting. */
937 interval = cur_time - client->first_sending;
938
939 /* If we're past the panic timeout, call the script and tell it
940 we haven't found anything for this interface yet. */
941 if (interval > config->timeout) {
942 state_panic();
943 return;
944 }
945
946 /* If we're selecting media, try the whole list before doing
947 the exponential backoff, but if we've already received an
948 offer, stop looping, because we obviously have it right. */
949 if (!client->offered_leases && config->media) {
950 int fail = 0;
951again:
952 if (client->medium) {
953 client->medium = client->medium->next;
954 increase = 0;
955 }
956 if (!client->medium) {
957 if (fail)
958 error("No valid media types for %s!", ifi->name);
959 client->medium = config->media;
960 increase = 1;
961 }
962
963 note("Trying medium \"%s\" %d", client->medium->string,
964 increase);
965 script_init("MEDIUM", client->medium);
966 if (script_go())
967 goto again;
968 }
969
970 /*
971 * If we're supposed to increase the interval, do so. If it's
972 * currently zero (i.e., we haven't sent any packets yet), set
973 * it to initial_interval; otherwise, add to it a random
974 * number between zero and two times itself. On average, this
975 * means that it will double with every transmission.
976 */
977 if (increase) {
978 if (!client->interval)
979 client->interval = config->initial_interval;
980 else {
981 client->interval += (arc4random() >> 2) %
982 (2 * client->interval);
983 }
984
985 /* Don't backoff past cutoff. */
986 if (client->interval > config->backoff_cutoff)
987 client->interval = ((config->backoff_cutoff / 2)
988 + ((arc4random() >> 2) %
989 config->backoff_cutoff));
990 } else if (!client->interval)
991 client->interval = config->initial_interval;
992
993 /* If the backoff would take us to the panic timeout, just use that
994 as the interval. */
995 if (cur_time + client->interval >
996 client->first_sending + config->timeout)
997 client->interval = (client->first_sending +
998 config->timeout) - cur_time + 1;
999
1000 /* Record the number of seconds since we started sending. */
1001 if (interval < 65536)
1002 client->packet.secs = htons(interval);
1003 else
1004 client->packet.secs = htons(65535);
1005 client->secs = client->packet.secs;
1006
1007 note("DHCPDISCOVER on %s to %s port %d interval %ld",
1008 ifi->name, inet_ntoa(sockaddr_broadcast.sin_addr),
1009 ntohs(sockaddr_broadcast.sin_port), client->interval);
1010
1011 /* Send out a packet. */
1012 send_packet(inaddr_any, &sockaddr_broadcast, NULL);
1013
1014 add_timeout(cur_time + client->interval, send_discover);
1015}
1016
1017/*
1018 * state_panic gets called if we haven't received any offers in a preset
1019 * amount of time. When this happens, we try to use existing leases
1020 * that haven't yet expired, and failing that, we call the client script
1021 * and hope it can do something.
1022 */
1023void
1024state_panic(void)
1025{
1026 struct client_lease *loop = client->active;
1027 struct client_lease *lp;
1028
1029 note("No DHCPOFFERS received.");
1030
1031 /* We may not have an active lease, but we may have some
1032 predefined leases that we can try. */
1033 if (!client->active && client->leases)
1034 goto activate_next;
1035
1036 /* Run through the list of leases and see if one can be used. */
1037 while (client->active) {
1038 if (client->active->expiry > cur_time) {
1039 note("Trying recorded lease %s",
1040 piaddr(client->active->address));
1041 /* Run the client script with the existing
1042 parameters. */
1043 script_init("TIMEOUT",
1044 client->active->medium);
1045 script_write_params("new_", client->active);
1046 if (client->alias)
1047 script_write_params("alias_",
1048 client->alias);
1049
1050 /* If the old lease is still good and doesn't
1051 yet need renewal, go into BOUND state and
1052 timeout at the renewal time. */
1053 if (!script_go()) {
1054 if (cur_time <
1055 client->active->renewal) {
1056 client->state = S_BOUND;
1057 note("bound: renewal in %ld seconds.",
1058 client->active->renewal -
1059 cur_time);
1060 add_timeout(client->active->renewal,
1061 state_bound);
1062 } else {
1063 client->state = S_BOUND;
1064 note("bound: immediate renewal.");
1065 state_bound();
1066 }
1067 reinitialize_interface();
1068 go_daemon();
1069 return;
1070 }
1071 }
1072
1073 /* If there are no other leases, give up. */
1074 if (!client->leases) {
1075 client->leases = client->active;
1076 client->active = NULL;
1077 break;
1078 }
1079
1080activate_next:
1081 /* Otherwise, put the active lease at the end of the
1082 lease list, and try another lease.. */
1083 for (lp = client->leases; lp->next; lp = lp->next)
1084 ;
1085 lp->next = client->active;
1086 if (lp->next)
1087 lp->next->next = NULL;
1088 client->active = client->leases;
1089 client->leases = client->leases->next;
1090
1091 /* If we already tried this lease, we've exhausted the
1092 set of leases, so we might as well give up for
1093 now. */
1094 if (client->active == loop)
1095 break;
1096 else if (!loop)
1097 loop = client->active;
1098 }
1099
1100 /* No leases were available, or what was available didn't work, so
1101 tell the shell script that we failed to allocate an address,
1102 and try again later. */
1103 note("No working leases in persistent database - sleeping.");
1104 script_init("FAIL", NULL);
1105 if (client->alias)
1106 script_write_params("alias_", client->alias);
1107 script_go();
1108 client->state = S_INIT;
1109 add_timeout(cur_time + config->retry_interval, state_init);
1110 go_daemon();
1111}
1112
1113void
1114send_request(void)
1115{
1116 struct sockaddr_in destination;
1117 struct in_addr from;
1118 int interval;
1119
1120 /* Figure out how long it's been since we started transmitting. */
1121 interval = cur_time - client->first_sending;
1122
1123 /* If we're in the INIT-REBOOT or REQUESTING state and we're
1124 past the reboot timeout, go to INIT and see if we can
1125 DISCOVER an address... */
1126 /* XXX In the INIT-REBOOT state, if we don't get an ACK, it
1127 means either that we're on a network with no DHCP server,
1128 or that our server is down. In the latter case, assuming
1129 that there is a backup DHCP server, DHCPDISCOVER will get
1130 us a new address, but we could also have successfully
1131 reused our old address. In the former case, we're hosed
1132 anyway. This is not a win-prone situation. */
1133 if ((client->state == S_REBOOTING ||
1134 client->state == S_REQUESTING) &&
1135 interval > config->reboot_timeout) {
1136cancel:
1137 client->state = S_INIT;
1138 cancel_timeout(send_request);
1139 state_init();
1140 return;
1141 }
1142
1143 /* If we're in the reboot state, make sure the media is set up
1144 correctly. */
1145 if (client->state == S_REBOOTING &&
1146 !client->medium &&
1147 client->active->medium) {
1148 script_init("MEDIUM", client->active->medium);
1149
1150 /* If the medium we chose won't fly, go to INIT state. */
1151 if (script_go())
1152 goto cancel;
1153
1154 /* Record the medium. */
1155 client->medium = client->active->medium;
1156 }
1157
1158 /* If the lease has expired, relinquish the address and go back
1159 to the INIT state. */
1160 if (client->state != S_REQUESTING &&
1161 cur_time > client->active->expiry) {
1162 /* Run the client script with the new parameters. */
1163 script_init("EXPIRE", NULL);
1164 script_write_params("old_", client->active);
1165 if (client->alias)
1166 script_write_params("alias_", client->alias);
1167 script_go();
1168
1169 /* Now do a preinit on the interface so that we can
1170 discover a new address. */
1171 script_init("PREINIT", NULL);
1172 if (client->alias)
1173 script_write_params("alias_", client->alias);
1174 script_go();
1175
1176 client->state = S_INIT;
1177 state_init();
1178 return;
1179 }
1180
1181 /* Do the exponential backoff... */
1182 if (!client->interval)
1183 client->interval = config->initial_interval;
1184 else
1185 client->interval += ((arc4random() >> 2) %
1186 (2 * client->interval));
1187
1188 /* Don't backoff past cutoff. */
1189 if (client->interval > config->backoff_cutoff)
1190 client->interval = ((config->backoff_cutoff / 2) +
1191 ((arc4random() >> 2) % client->interval));
1192
1193 /* If the backoff would take us to the expiry time, just set the
1194 timeout to the expiry time. */
1195 if (client->state != S_REQUESTING && cur_time + client->interval >
1196 client->active->expiry)
1197 client->interval = client->active->expiry - cur_time + 1;
1198
1199 /* If the lease T2 time has elapsed, or if we're not yet bound,
1200 broadcast the DHCPREQUEST rather than unicasting. */
1201 memset(&destination, 0, sizeof(destination));
1202 if (client->state == S_REQUESTING ||
1203 client->state == S_REBOOTING ||
1204 cur_time > client->active->rebind)
1205 destination.sin_addr.s_addr = INADDR_BROADCAST;
1206 else
1207 memcpy(&destination.sin_addr.s_addr, client->destination.iabuf,
1208 sizeof(destination.sin_addr.s_addr));
1209 destination.sin_port = htons(REMOTE_PORT);
1210 destination.sin_family = AF_INET;
1211 destination.sin_len = sizeof(destination);
1212
1213 if (client->state != S_REQUESTING)
1214 memcpy(&from, client->active->address.iabuf, sizeof(from));
1215 else
1216 from.s_addr = INADDR_ANY;
1217
1218 /* Record the number of seconds since we started sending. */
1219 if (client->state == S_REQUESTING)
1220 client->packet.secs = client->secs;
1221 else {
1222 if (interval < 65536)
1223 client->packet.secs = htons(interval);
1224 else
1225 client->packet.secs = htons(65535);
1226 }
1227
1228 note("DHCPREQUEST on %s to %s port %d", ifi->name,
1229 inet_ntoa(destination.sin_addr), ntohs(destination.sin_port));
1230
1231 /* Send out a packet. */
1232 send_packet(from, &destination, NULL);
1233
1234 add_timeout(cur_time + client->interval, send_request);
1235}
1236
1237void
1238send_decline(void)
1239{
1240 note("DHCPDECLINE on %s to %s port %d", ifi->name,
1241 inet_ntoa(sockaddr_broadcast.sin_addr),
1242 ntohs(sockaddr_broadcast.sin_port));
1243
1244 /* Send out a packet. */
1245 send_packet(inaddr_any, &sockaddr_broadcast, NULL);
1246}
1247
1248void
1249make_discover(struct client_lease *lease)
1250{
1251 unsigned char discover = DHCPDISCOVER;
1252 struct option_data options[256];
1253 int i;
1254
1255 memset(options, 0, sizeof(options));
1256 memset(&client->packet, 0, sizeof(client->packet));
1257
1258 /* Set DHCP_MESSAGE_TYPE to DHCPDISCOVER */
1259 i = DHO_DHCP_MESSAGE_TYPE;
1260 options[i].data = &discover;
1261 options[i].len = sizeof(discover);
1262
1263 /* Request the options we want */
1264 i = DHO_DHCP_PARAMETER_REQUEST_LIST;
1265 options[i].data = config->requested_options;
1266 options[i].len = config->requested_option_count;
1267
1268 /* If we had an address, try to get it again. */
1269 if (lease) {
1270 client->requested_address = lease->address;
1271 i = DHO_DHCP_REQUESTED_ADDRESS;
1272 options[i].data = lease->address.iabuf;
1273 options[i].len = lease->address.len;
1274 } else
1275 client->requested_address.len = 0;
1276
1277 /* Send any options requested in the config file. */
1278 for (i = 0; i < 256; i++)
1279 if (!options[i].data &&
1280 config->send_options[i].data) {
1281 options[i].data = config->send_options[i].data;
1282 options[i].len = config->send_options[i].len;
1283 }
1284
1285 /* Set up the option buffer to fit in a minimal UDP packet. */
1286 i = cons_options(client->packet.options, 576 - DHCP_FIXED_LEN,
1287 options);
1288 if (i == -1 || client->packet.options[i] != DHO_END)
1289 error("options do not fit in DHCPDISCOVER packet.");
1290 client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1291 if (client->packet_length < BOOTP_MIN_LEN)
1292 client->packet_length = BOOTP_MIN_LEN;
1293
1294 client->packet.op = BOOTREQUEST;
1295 client->packet.htype = ifi->hw_address.htype;
1296 client->packet.hlen = ifi->hw_address.hlen;
1297 client->packet.hops = 0;
1298 client->packet.xid = arc4random();
1299 client->packet.secs = 0; /* filled in by send_discover. */
1300 client->packet.flags = 0;
1301
1302 memset(&client->packet.ciaddr, 0, sizeof(client->packet.ciaddr));
1303 memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1304 memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1305 memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1306 memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1307 ifi->hw_address.hlen);
1308}
1309
1310void
1311make_request(struct client_lease * lease)
1312{
1313 unsigned char request = DHCPREQUEST;
1314 struct option_data options[256];
1315 int i;
1316
1317 memset(options, 0, sizeof(options));
1318 memset(&client->packet, 0, sizeof(client->packet));
1319
1320 /* Set DHCP_MESSAGE_TYPE to DHCPREQUEST */
1321 i = DHO_DHCP_MESSAGE_TYPE;
1322 options[i].data = &request;
1323 options[i].len = sizeof(request);
1324
1325 /* Request the options we want */
1326 i = DHO_DHCP_PARAMETER_REQUEST_LIST;
1327 options[i].data = config->requested_options;
1328 options[i].len = config->requested_option_count;
1329
1330 /* If we are requesting an address that hasn't yet been assigned
1331 to us, use the DHCP Requested Address option. */
1332 if (client->state == S_REQUESTING) {
1333 /* Send back the server identifier... */
1334 i = DHO_DHCP_SERVER_IDENTIFIER;
1335 options[i].data = lease->options[i].data;
1336 options[i].len = lease->options[i].len;
1337 }
1338 if (client->state == S_REQUESTING ||
1339 client->state == S_REBOOTING) {
1340 client->requested_address = lease->address;
1341 i = DHO_DHCP_REQUESTED_ADDRESS;
1342 options[i].data = lease->address.iabuf;
1343 options[i].len = lease->address.len;
1344 } else
1345 client->requested_address.len = 0;
1346
1347 /* Send any options requested in the config file. */
1348 for (i = 0; i < 256; i++)
1349 if (!options[i].data && config->send_options[i].data) {
1350 options[i].data = config->send_options[i].data;
1351 options[i].len = config->send_options[i].len;
1352 }
1353
1354 /* Set up the option buffer to fit in a minimal UDP packet. */
1355 i = cons_options(client->packet.options, 576 - DHCP_FIXED_LEN,
1356 options);
1357 if (i == -1 || client->packet.options[i] != DHO_END)
1358 error("options do not fit in DHCPREQUEST packet.");
1359 client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1360 if (client->packet_length < BOOTP_MIN_LEN)
1361 client->packet_length = BOOTP_MIN_LEN;
1362
1363 client->packet.op = BOOTREQUEST;
1364 client->packet.htype = ifi->hw_address.htype;
1365 client->packet.hlen = ifi->hw_address.hlen;
1366 client->packet.hops = 0;
1367 client->packet.xid = client->xid;
1368 client->packet.secs = 0; /* Filled in by send_request. */
1369 client->packet.flags = 0;
1370
1371 /* If we own the address we're requesting, put it in ciaddr;
1372 otherwise set ciaddr to zero. */
1373 if (client->state == S_BOUND ||
1374 client->state == S_RENEWING ||
1375 client->state == S_REBINDING) {
1376 memcpy(&client->packet.ciaddr,
1377 lease->address.iabuf, lease->address.len);
1378 } else {
1379 memset(&client->packet.ciaddr, 0,
1380 sizeof(client->packet.ciaddr));
1381 }
1382
1383 memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1384 memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1385 memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1386 memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1387 ifi->hw_address.hlen);
1388}
1389
1390void
1391make_decline(struct client_lease *lease)
1392{
1393 struct option_data options[256];
1394 unsigned char decline = DHCPDECLINE;
1395 int i;
1396
1397 memset(options, 0, sizeof(options));
1398 memset(&client->packet, 0, sizeof(client->packet));
1399
1400 /* Set DHCP_MESSAGE_TYPE to DHCPDECLINE */
1401 i = DHO_DHCP_MESSAGE_TYPE;
1402 options[i].data = &decline;
1403 options[i].len = sizeof(decline);
1404
1405 /* Send back the server identifier... */
1406 i = DHO_DHCP_SERVER_IDENTIFIER;
1407 options[i].data = lease->options[i].data;
1408 options[i].len = lease->options[i].len;
1409
1410 /* Send back the address we're declining. */
1411 i = DHO_DHCP_REQUESTED_ADDRESS;
1412 options[i].data = lease->address.iabuf;
1413 options[i].len = lease->address.len;
1414
1415 /* Send the uid if the user supplied one. */
1416 i = DHO_DHCP_CLIENT_IDENTIFIER;
1417 if (config->send_options[i].len) {
1418 options[i].data = config->send_options[i].data;
1419 options[i].len = config->send_options[i].len;
1420 }
1421
1422 /* Set up the option buffer to fit in a minimal UDP packet. */
1423 i = cons_options(client->packet.options, 576 - DHCP_FIXED_LEN,
1424 options);
1425 if (i == -1 || client->packet.options[i] != DHO_END)
1426 error("options do not fit in DHCPDECLINE packet.");
1427 client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1428 if (client->packet_length < BOOTP_MIN_LEN)
1429 client->packet_length = BOOTP_MIN_LEN;
1430
1431 client->packet.op = BOOTREQUEST;
1432 client->packet.htype = ifi->hw_address.htype;
1433 client->packet.hlen = ifi->hw_address.hlen;
1434 client->packet.hops = 0;
1435 client->packet.xid = client->xid;
1436 client->packet.secs = 0; /* Filled in by send_request. */
1437 client->packet.flags = 0;
1438
1439 /* ciaddr must always be zero. */
1440 memset(&client->packet.ciaddr, 0, sizeof(client->packet.ciaddr));
1441 memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1442 memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1443 memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1444 memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1445 ifi->hw_address.hlen);
1446}
1447
1448void
1449free_client_lease(struct client_lease *lease)
1450{
1451 int i;
1452
1453 if (lease->server_name)
1454 free(lease->server_name);
1455 if (lease->filename)
1456 free(lease->filename);
1457 for (i = 0; i < 256; i++) {
1458 if (lease->options[i].len)
1459 free(lease->options[i].data);
1460 }
1461 free(lease);
1462}
1463
1464void
1465rewrite_client_leases(void)
1466{
1467 struct client_lease *lp;
1468
1469 if (!leaseFile) /* XXX */
1470 error("lease file not open");
1471
1472 fflush(leaseFile);
1473 rewind(leaseFile);
1474
1475 for (lp = client->leases; lp; lp = lp->next)
1476 write_client_lease(lp, 1);
1477 if (client->active)
1478 write_client_lease(client->active, 1);
1479
1480 fflush(leaseFile);
1481 ftruncate(fileno(leaseFile), ftello(leaseFile));
1482 fsync(fileno(leaseFile));
1483}
1484
1485void
1486write_client_lease(struct client_lease *lease, int rewrite)
1487{
1488 static int leases_written;
1489 struct tm *t;
1490 int i;
1491
1492 if (!rewrite) {
1493 if (leases_written++ > 20) {
1494 rewrite_client_leases();
1495 leases_written = 0;
1496 }
1497 }
1498
1499 /* If the lease came from the config file, we don't need to stash
1500 a copy in the lease database. */
1501 if (lease->is_static)
1502 return;
1503
1504 if (!leaseFile) /* XXX */
1505 error("lease file not open");
1506
1507 fprintf(leaseFile, "lease {\n");
1508 if (lease->is_bootp)
1509 fprintf(leaseFile, " bootp;\n");
1510 fprintf(leaseFile, " interface \"%s\";\n", ifi->name);
1511 fprintf(leaseFile, " fixed-address %s;\n", piaddr(lease->address));
1512 if (lease->filename)
1513 fprintf(leaseFile, " filename \"%s\";\n", lease->filename);
1514 if (lease->server_name)
1515 fprintf(leaseFile, " server-name \"%s\";\n",
1516 lease->server_name);
1517 if (lease->medium)
1518 fprintf(leaseFile, " medium \"%s\";\n", lease->medium->string);
1519 for (i = 0; i < 256; i++)
1520 if (lease->options[i].len)
1521 fprintf(leaseFile, " option %s %s;\n",
1522 dhcp_options[i].name,
1523 pretty_print_option(i, lease->options[i].data,
1524 lease->options[i].len, 1, 1));
1525
1526 t = gmtime(&lease->renewal);
1527 fprintf(leaseFile, " renew %d %d/%d/%d %02d:%02d:%02d;\n",
1528 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1529 t->tm_hour, t->tm_min, t->tm_sec);
1530 t = gmtime(&lease->rebind);
1531 fprintf(leaseFile, " rebind %d %d/%d/%d %02d:%02d:%02d;\n",
1532 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1533 t->tm_hour, t->tm_min, t->tm_sec);
1534 t = gmtime(&lease->expiry);
1535 fprintf(leaseFile, " expire %d %d/%d/%d %02d:%02d:%02d;\n",
1536 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1537 t->tm_hour, t->tm_min, t->tm_sec);
1538 fprintf(leaseFile, "}\n");
1539 fflush(leaseFile);
1540}
1541
1542void
1543script_init(char *reason, struct string_list *medium)
1544{
1545 size_t len, mediumlen = 0;
1546 struct imsg_hdr hdr;
1547 struct buf *buf;
1548
1549 if (medium != NULL && medium->string != NULL)
1550 mediumlen = strlen(medium->string);
1551
1552 hdr.code = IMSG_SCRIPT_INIT;
1553 hdr.len = sizeof(struct imsg_hdr) +
1554 sizeof(size_t) + mediumlen +
1555 sizeof(size_t) + strlen(reason);
1556
1557 buf = buf_open(hdr.len);
1558
1559 buf_add(buf, &hdr, sizeof(hdr));
1560 buf_add(buf, &mediumlen, sizeof(mediumlen));
1561 if (mediumlen > 0)
1562 buf_add(buf, medium->string, mediumlen);
1563 len = strlen(reason);
1564 buf_add(buf, &len, sizeof(len));
1565 buf_add(buf, reason, len);
1566
1567 buf_close(privfd, buf);
1568}
1569
1570void
1571priv_script_init(char *reason, char *medium)
1572{
1573 client->scriptEnvsize = 100;
1574 if (client->scriptEnv == NULL)
1575 client->scriptEnv =
1576 calloc(client->scriptEnvsize, sizeof(char *));
1577 if (client->scriptEnv == NULL)
1578 error("script_init: no memory for environment");
1579
1580 client->scriptEnv[0] = strdup(CLIENT_PATH);
1581 if (client->scriptEnv[0] == NULL)
1582 error("script_init: no memory for environment");
1583
1584 client->scriptEnv[1] = NULL;
1585
1586 script_set_env("", "interface", ifi->name);
1587
1588 if (medium)
1589 script_set_env("", "medium", medium);
1590
1591 script_set_env("", "reason", reason);
1592}
1593
1594void
1595priv_script_write_params(char *prefix, struct client_lease *lease)
1596{
1597 u_int8_t dbuf[1500];
1598 int i, len = 0;
1599 char tbuf[128];
1600
1601 script_set_env(prefix, "ip_address", piaddr(lease->address));
1602
1603 if (lease->options[DHO_SUBNET_MASK].len &&
1604 (lease->options[DHO_SUBNET_MASK].len <
1605 sizeof(lease->address.iabuf))) {
1606 struct iaddr netmask, subnet, broadcast;
1607
1608 memcpy(netmask.iabuf, lease->options[DHO_SUBNET_MASK].data,
1609 lease->options[DHO_SUBNET_MASK].len);
1610 netmask.len = lease->options[DHO_SUBNET_MASK].len;
1611
1612 subnet = subnet_number(lease->address, netmask);
1613 if (subnet.len) {
1614 script_set_env(prefix, "network_number",
1615 piaddr(subnet));
1616 if (!lease->options[DHO_BROADCAST_ADDRESS].len) {
1617 broadcast = broadcast_addr(subnet, netmask);
1618 if (broadcast.len)
1619 script_set_env(prefix,
1620 "broadcast_address",
1621 piaddr(broadcast));
1622 }
1623 }
1624 }
1625
1626 if (lease->filename)
1627 script_set_env(prefix, "filename", lease->filename);
1628 if (lease->server_name)
1629 script_set_env(prefix, "server_name",
1630 lease->server_name);
1631 for (i = 0; i < 256; i++) {
1632 u_int8_t *dp = NULL;
1633
1634 if (config->defaults[i].len) {
1635 if (lease->options[i].len) {
1636 switch (config->default_actions[i]) {
1637 case ACTION_DEFAULT:
1638 dp = lease->options[i].data;
1639 len = lease->options[i].len;
1640 break;
1641 case ACTION_SUPERSEDE:
1642supersede:
1643 dp = config->defaults[i].data;
1644 len = config->defaults[i].len;
1645 break;
1646 case ACTION_PREPEND:
1647 len = config->defaults[i].len +
1648 lease->options[i].len;
1649 if (len > sizeof(dbuf)) {
1650 warning("no space to %s %s",
1651 "prepend option",
1652 dhcp_options[i].name);
1653 goto supersede;
1654 }
1655 dp = dbuf;
1656 memcpy(dp,
1657 config->defaults[i].data,
1658 config->defaults[i].len);
1659 memcpy(dp +
1660 config->defaults[i].len,
1661 lease->options[i].data,
1662 lease->options[i].len);
1663 dp[len] = '\0';
1664 break;
1665 case ACTION_APPEND:
1666 len = config->defaults[i].len +
1667 lease->options[i].len;
1668 if (len > sizeof(dbuf)) {
1669 warning("no space to %s %s",
1670 "append option",
1671 dhcp_options[i].name);
1672 goto supersede;
1673 }
1674 dp = dbuf;
1675 memcpy(dp, lease->options[i].data,
1676 lease->options[i].len);
1677 memcpy(dp + lease->options[i].len,
1678 config->defaults[i].data,
1679 config->defaults[i].len);
1680 dp[len] = '\0';
1681 }
1682 } else {
1683 dp = config->defaults[i].data;
1684 len = config->defaults[i].len;
1685 }
1686 } else if (lease->options[i].len) {
1687 len = lease->options[i].len;
1688 dp = lease->options[i].data;
1689 } else {
1690 len = 0;
1691 }
1692 if (len) {
1693 char name[256];
1694
1695 if (dhcp_option_ev_name(name, sizeof(name),
1696 &dhcp_options[i]))
1697 script_set_env(prefix, name,
1698 pretty_print_option(i, dp, len, 0, 0));
1699 }
1700 }
1701 snprintf(tbuf, sizeof(tbuf), "%d", (int)lease->expiry);
1702 script_set_env(prefix, "expiry", tbuf);
1703}
1704
1705void
1706script_write_params(char *prefix, struct client_lease *lease)
1707{
1708 size_t fn_len = 0, sn_len = 0, pr_len = 0;
1709 struct imsg_hdr hdr;
1710 struct buf *buf;
1711 int i;
1712
1713 if (lease->filename != NULL)
1714 fn_len = strlen(lease->filename);
1715 if (lease->server_name != NULL)
1716 sn_len = strlen(lease->server_name);
1717 if (prefix != NULL)
1718 pr_len = strlen(prefix);
1719
1720 hdr.code = IMSG_SCRIPT_WRITE_PARAMS;
1721 hdr.len = sizeof(hdr) + sizeof(struct client_lease) +
1722 sizeof(size_t) + fn_len + sizeof(size_t) + sn_len +
1723 sizeof(size_t) + pr_len;
1724
1725 for (i = 0; i < 256; i++)
1726 hdr.len += sizeof(int) + lease->options[i].len;
1727
1728 scripttime = time(NULL);
1729
1730 buf = buf_open(hdr.len);
1731
1732 buf_add(buf, &hdr, sizeof(hdr));
1733 buf_add(buf, lease, sizeof(struct client_lease));
1734 buf_add(buf, &fn_len, sizeof(fn_len));
1735 buf_add(buf, lease->filename, fn_len);
1736 buf_add(buf, &sn_len, sizeof(sn_len));
1737 buf_add(buf, lease->server_name, sn_len);
1738 buf_add(buf, &pr_len, sizeof(pr_len));
1739 buf_add(buf, prefix, pr_len);
1740
1741 for (i = 0; i < 256; i++) {
1742 buf_add(buf, &lease->options[i].len,
1743 sizeof(lease->options[i].len));
1744 buf_add(buf, lease->options[i].data,
1745 lease->options[i].len);
1746 }
1747
1748 buf_close(privfd, buf);
1749}
1750
1751int
1752script_go(void)
1753{
1754 struct imsg_hdr hdr;
1755 struct buf *buf;
1756 int ret;
1757
1758 scripttime = time(NULL);
1759
1760 hdr.code = IMSG_SCRIPT_GO;
1761 hdr.len = sizeof(struct imsg_hdr);
1762
1763 buf = buf_open(hdr.len);
1764
1765 buf_add(buf, &hdr, sizeof(hdr));
1766 buf_close(privfd, buf);
1767
1768 bzero(&hdr, sizeof(hdr));
1769 buf_read(privfd, &hdr, sizeof(hdr));
1770 if (hdr.code != IMSG_SCRIPT_GO_RET)
1771 error("unexpected msg type %u", hdr.code);
1772 if (hdr.len != sizeof(hdr) + sizeof(int))
1773 error("received corrupted message");
1774 buf_read(privfd, &ret, sizeof(ret));
1775
1776 return (ret);
1777}
1778
1779int
1780priv_script_go(void)
1781{
1782 char *scriptName, *argv[2], **envp;
1783 int pid, wpid, wstatus;
1784
1785 scripttime = time(NULL);
1786
1787 scriptName = config->script_name;
1788 envp = client->scriptEnv;
1789
1790 argv[0] = scriptName;
1791 argv[1] = NULL;
1792
1793 pid = fork();
1794 if (pid < 0) {
1795 error("fork: %m");
1796 wstatus = 0;
1797 } else if (pid) {
1798 do {
1799 wpid = wait(&wstatus);
1800 } while (wpid != pid && wpid > 0);
1801 if (wpid < 0) {
1802 error("wait: %m");
1803 wstatus = 0;
1804 }
1805 } else {
1806 execve(scriptName, argv, envp);
1807 error("execve (%s, ...): %m", scriptName);
1808 }
1809
1810 script_flush_env();
1811
1812 return (WEXITSTATUS(wstatus));
1813}
1814
1815void
1816script_set_env(const char *prefix, const char *name, const char *value)
1817{
1818 int i, j, namelen;
1819
1820 namelen = strlen(name);
1821
1822 for (i = 0; client->scriptEnv[i]; i++)
1823 if (strncmp(client->scriptEnv[i], name, namelen) == 0 &&
1824 client->scriptEnv[i][namelen] == '=')
1825 break;
1826
1827 if (client->scriptEnv[i])
1828 /* Reuse the slot. */
1829 free(client->scriptEnv[i]);
1830 else {
1831 /* New variable. Expand if necessary. */
1832 if (i >= client->scriptEnvsize - 1) {
1833 char **newscriptEnv;
1834 int newscriptEnvsize = client->scriptEnvsize + 50;
1835
1836 newscriptEnv = realloc(client->scriptEnv,
1837 newscriptEnvsize);
1838 if (newscriptEnv == NULL) {
1839 free(client->scriptEnv);
1840 client->scriptEnv = NULL;
1841 client->scriptEnvsize = 0;
1842 error("script_set_env: no memory for variable");
1843 }
1844 client->scriptEnv = newscriptEnv;
1845 client->scriptEnvsize = newscriptEnvsize;
1846 }
1847 /* need to set the NULL pointer at end of array beyond
1848 the new slot. */
1849 client->scriptEnv[i + 1] = NULL;
1850 }
1851 /* Allocate space and format the variable in the appropriate slot. */
1852 client->scriptEnv[i] = malloc(strlen(prefix) + strlen(name) + 1 +
1853 strlen(value) + 1);
1854 if (client->scriptEnv[i] == NULL)
1855 error("script_set_env: no memory for variable assignment");
1856
1857 /* No `` or $() command substitution allowed in environment values! */
1858 for (j = 0; j < strlen(value); j++)
1859 switch (value[j]) {
1860 case '`':
1861 case '$':
1862 error("illegal character (%c) in value '%s'", value[j],
1863 value);
1864 /* not reached */
1865 }
1866 snprintf(client->scriptEnv[i], strlen(prefix) + strlen(name) +
1867 1 + strlen(value) + 1, "%s%s=%s", prefix, name, value);
1868}
1869
1870void
1871script_flush_env(void)
1872{
1873 int i;
1874
1875 for (i = 0; client->scriptEnv[i]; i++) {
1876 free(client->scriptEnv[i]);
1877 client->scriptEnv[i] = NULL;
1878 }
1879 client->scriptEnvsize = 0;
1880}
1881
1882int
1883dhcp_option_ev_name(char *buf, size_t buflen, const struct option *option)
1884{
1885 size_t i;
1886
1887 for (i = 0; option->name[i]; i++) {
1888 if (i + 1 == buflen)
1889 return 0;
1890 if (option->name[i] == '-')
1891 buf[i] = '_';
1892 else
1893 buf[i] = option->name[i];
1894 }
1895
1896 buf[i] = 0;
1897 return 1;
1898}
1899
1900void
1901go_daemon(void)
1902{
1903 static int state = 0;
1904
1905 if (no_daemon || state)
1906 return;
1907
1908 state = 1;
1909
1910 /* Stop logging to stderr... */
1911 log_perror = 0;
1912
1913 if (daemon(1, 0) == -1)
1914 error("daemon");
1915
1916 /* we are chrooted, daemon(3) fails to open /dev/null */
1917 if (nullfd != -1) {
1918 dup2(nullfd, STDIN_FILENO);
1919 dup2(nullfd, STDOUT_FILENO);
1920 dup2(nullfd, STDERR_FILENO);
1921 close(nullfd);
1922 nullfd = -1;
1923 }
1924}
1925
1926int
1927check_option(struct client_lease *l, int option)
1928{
1929 char *opbuf;
1930 char *sbuf;
1931
1932 /* we use this, since this is what gets passed to dhclient-script */
1933
1934 opbuf = pretty_print_option(option, l->options[option].data,
1935 l->options[option].len, 0, 0);
1936
1937 sbuf = option_as_string(option, l->options[option].data,
1938 l->options[option].len);
1939
1940 switch (option) {
1941 case DHO_SUBNET_MASK:
1942 case DHO_TIME_SERVERS:
1943 case DHO_NAME_SERVERS:
1944 case DHO_ROUTERS:
1945 case DHO_DOMAIN_NAME_SERVERS:
1946 case DHO_LOG_SERVERS:
1947 case DHO_COOKIE_SERVERS:
1948 case DHO_LPR_SERVERS:
1949 case DHO_IMPRESS_SERVERS:
1950 case DHO_RESOURCE_LOCATION_SERVERS:
1951 case DHO_SWAP_SERVER:
1952 case DHO_BROADCAST_ADDRESS:
1953 case DHO_NIS_SERVERS:
1954 case DHO_NTP_SERVERS:
1955 case DHO_NETBIOS_NAME_SERVERS:
1956 case DHO_NETBIOS_DD_SERVER:
1957 case DHO_FONT_SERVERS:
1958 case DHO_DHCP_SERVER_IDENTIFIER:
1959 if (!ipv4addrs(opbuf)) {
1960 warning("Invalid IP address in option: %s", opbuf);
1961 return (0);
1962 }
1963 return (1);
1964 case DHO_HOST_NAME:
1965 case DHO_DOMAIN_NAME:
1966 case DHO_NIS_DOMAIN:
1967 if (!res_hnok(sbuf)) {
1968 warning("Bogus Host Name option %d: %s (%s)", option,
1969 sbuf, opbuf);
1970 l->options[option].len = 0;
1971 free(l->options[option].data);
1972 }
1973 return (1);
1974 case DHO_PAD:
1975 case DHO_TIME_OFFSET:
1976 case DHO_BOOT_SIZE:
1977 case DHO_MERIT_DUMP:
1978 case DHO_ROOT_PATH:
1979 case DHO_EXTENSIONS_PATH:
1980 case DHO_IP_FORWARDING:
1981 case DHO_NON_LOCAL_SOURCE_ROUTING:
1982 case DHO_POLICY_FILTER:
1983 case DHO_MAX_DGRAM_REASSEMBLY:
1984 case DHO_DEFAULT_IP_TTL:
1985 case DHO_PATH_MTU_AGING_TIMEOUT:
1986 case DHO_PATH_MTU_PLATEAU_TABLE:
1987 case DHO_INTERFACE_MTU:
1988 case DHO_ALL_SUBNETS_LOCAL:
1989 case DHO_PERFORM_MASK_DISCOVERY:
1990 case DHO_MASK_SUPPLIER:
1991 case DHO_ROUTER_DISCOVERY:
1992 case DHO_ROUTER_SOLICITATION_ADDRESS:
1993 case DHO_STATIC_ROUTES:
1994 case DHO_TRAILER_ENCAPSULATION:
1995 case DHO_ARP_CACHE_TIMEOUT:
1996 case DHO_IEEE802_3_ENCAPSULATION:
1997 case DHO_DEFAULT_TCP_TTL:
1998 case DHO_TCP_KEEPALIVE_INTERVAL:
1999 case DHO_TCP_KEEPALIVE_GARBAGE:
2000 case DHO_VENDOR_ENCAPSULATED_OPTIONS:
2001 case DHO_NETBIOS_NODE_TYPE:
2002 case DHO_NETBIOS_SCOPE:
2003 case DHO_X_DISPLAY_MANAGER:
2004 case DHO_DHCP_REQUESTED_ADDRESS:
2005 case DHO_DHCP_LEASE_TIME:
2006 case DHO_DHCP_OPTION_OVERLOAD:
2007 case DHO_DHCP_MESSAGE_TYPE:
2008 case DHO_DHCP_PARAMETER_REQUEST_LIST:
2009 case DHO_DHCP_MESSAGE:
2010 case DHO_DHCP_MAX_MESSAGE_SIZE:
2011 case DHO_DHCP_RENEWAL_TIME:
2012 case DHO_DHCP_REBINDING_TIME:
2013 case DHO_DHCP_CLASS_IDENTIFIER:
2014 case DHO_DHCP_CLIENT_IDENTIFIER:
2015 case DHO_DHCP_USER_CLASS_ID:
2016 case DHO_END:
2017 return (1);
2018 default:
2019 warning("unknown dhcp option value 0x%x", option);
2020 return (unknown_ok);
2021 }
2022}
2023
2024int
2025res_hnok(const char *name)
2026{
2027 const char *dn = name;
2028 int pch = '.', ch = *dn++;
2029 int warn = 0;
2030
2031 while (ch != '\0') {
2032 int nch = *dn++;
2033
2034 if (ch == '.') {
2035 ;
2036 } else if (pch == '.' || nch == '.' || nch == '\0') {
2037 if (!isalnum(ch))
2038 return (0);
2039 } else if (!isalnum(ch) && ch != '-' && ch != '_')
2040 return (0);
2041 else if (ch == '_' && warn == 0) {
2042 warning("warning: hostname %s contains an "
2043 "underscore which violates RFC 952", name);
2044 warn++;
2045 }
2046 pch = ch, ch = nch;
2047 }
2048 return (1);
2049}
2050
2051/* Does buf consist only of dotted decimal ipv4 addrs?
2052 * return how many if so,
2053 * otherwise, return 0
2054 */
2055int
2056ipv4addrs(char * buf)
2057{
2058 struct in_addr jnk;
2059 int count = 0;
2060
2061 while (inet_aton(buf, &jnk) == 1){
2062 count++;
2063 while (*buf == '.' || isdigit(*buf))
2064 buf++;
2065 if (*buf == '\0')
2066 return (count);
2067 while (*buf == ' ')
2068 buf++;
2069 }
2070 return (0);
2071}
2072
2073char *
2074option_as_string(unsigned int code, unsigned char *data, int len)
2075{
2076 static char optbuf[32768]; /* XXX */
2077 char *op = optbuf;
2078 int opleft = sizeof(optbuf);
2079 unsigned char *dp = data;
2080
2081 if (code > 255)
2082 error("option_as_string: bad code %d", code);
2083
2084 for (; dp < data + len; dp++) {
2085 if (!isascii(*dp) || !isprint(*dp)) {
2086 if (dp + 1 != data + len || *dp != 0) {
2087 size_t oplen;
2088 snprintf(op, opleft, "\\%03o", *dp);
2089 oplen = strlen(op);
2090 op += oplen;
2091 opleft -= oplen;
2092 }
2093 } else if (*dp == '"' || *dp == '\'' || *dp == '$' ||
2094 *dp == '`' || *dp == '\\') {
2095 *op++ = '\\';
2096 *op++ = *dp;
2097 opleft -= 2;
2098 } else {
2099 *op++ = *dp;
2100 opleft--;
2101 }
2102 }
2103 if (opleft < 1)
2104 goto toobig;
2105 *op = 0;
2106 return optbuf;
2107toobig:
2108 warning("dhcp option too large");
2109 return "<error>";
2110}
2111
2112int
2113fork_privchld(int fd, int fd2)
2114{
2115 struct pollfd pfd[1];
a05d48e6 2116 int nfds, pfail = 0;
846204b6
HT
2117
2118 switch (fork()) {
2119 case -1:
2120 error("cannot fork");
2121 break;
2122 case 0:
2123 break;
2124 default:
2125 return (0);
2126 }
2127
2128 if (chdir("/") == -1)
2129 error("chdir(\"/\")");
2130
2131 setproctitle("%s [priv]", ifi->name);
2132
2133 dup2(nullfd, STDIN_FILENO);
2134 dup2(nullfd, STDOUT_FILENO);
2135 dup2(nullfd, STDERR_FILENO);
2136 close(nullfd);
2137 close(fd2);
2138
2139 for (;;) {
2140 pfd[0].fd = fd;
2141 pfd[0].events = POLLIN;
2142 if ((nfds = poll(pfd, 1, INFTIM)) == -1)
2143 if (errno != EINTR)
2144 error("poll error");
2145
a05d48e6
SG
2146 /*
2147 * Handle temporary errors, but bail if they persist.
2148 */
2149 if (nfds == 0 || !(pfd[0].revents & POLLIN)) {
2150 if (pfail > POLL_FAILURES)
2151 error("poll failed > %d times", POLL_FAILURES);
2152 sleep(pfail * POLL_FAILURE_WAIT);
2153 pfail++;
846204b6 2154 continue;
a05d48e6 2155 }
846204b6
HT
2156
2157 dispatch_imsg(fd);
2158 }
2159}