dhclient - Fix old bug that could cause lease mangling.
[dragonfly.git] / sbin / dhclient / dhclient.c
CommitLineData
44967127 1/* $OpenBSD: src/sbin/dhclient/dhclient.c,v 1.127 2009/05/25 00:17:40 stevesk Exp $ */
846204b6
HT
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
HT
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) */
846204b6
HT
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;
44967127 171 char *errmsg, buf[64];
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172
173 do {
174 n = read(routefd, &msg, sizeof(msg));
175 } while (n == -1 && errno == EINTR);
176
177 rtm = (struct rt_msghdr *)msg;
178 if (n < sizeof(rtm->rtm_msglen) || n < rtm->rtm_msglen ||
179 rtm->rtm_version != RTM_VERSION)
180 return;
181
182 switch (rtm->rtm_type) {
183 case RTM_NEWADDR:
184 ifam = (struct ifa_msghdr *)rtm;
185 if (ifam->ifam_index != ifi->index)
186 break;
187 if (findproto((char *)(ifam + 1), ifam->ifam_addrs) != AF_INET)
188 break;
189 sa = get_ifa((char *)(ifam + 1), ifam->ifam_addrs);
44967127
AHJ
190 if (sa == NULL) {
191 errmsg = "sa == NULL";
846204b6 192 goto die;
44967127 193 }
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HT
194
195 if ((a.len = sizeof(struct in_addr)) > sizeof(a.iabuf))
196 error("king bula sez: len mismatch");
197 memcpy(a.iabuf, &((struct sockaddr_in *)sa)->sin_addr, a.len);
198 if (addr_eq(a, defaddr))
199 break;
200
201 for (l = client->active; l != NULL; l = l->next)
202 if (addr_eq(a, l->address))
203 break;
204
205 if (l != NULL || (client->alias &&
206 addr_eq(a, client->alias->address)))
207 /* new addr is the one we set */
208 break;
44967127
AHJ
209 snprintf(buf, sizeof(buf), "%s: %s",
210 "new address not one we set", piaddr(a));
211 errmsg = buf;
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212 goto die;
213 case RTM_DELADDR:
214 ifam = (struct ifa_msghdr *)rtm;
215 if (ifam->ifam_index != ifi->index)
216 break;
217 if (findproto((char *)(ifam + 1), ifam->ifam_addrs) != AF_INET)
218 break;
219 if (scripttime == 0 || t < scripttime + 10)
220 break;
44967127 221 errmsg = "interface address deleted";
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222 goto die;
223 case RTM_IFINFO:
224 ifm = (struct if_msghdr *)rtm;
225 if (ifm->ifm_index != ifi->index)
226 break;
44967127
AHJ
227 if ((rtm->rtm_flags & RTF_UP) == 0) {
228 errmsg = "interface down";
846204b6 229 goto die;
44967127 230 }
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231
232 linkstat =
233 LINK_STATE_IS_UP(ifm->ifm_data.ifi_link_state) ? 1 : 0;
234 if (linkstat != ifi->linkstat) {
235 debug("link state %s -> %s",
236 ifi->linkstat ? "up" : "down",
237 linkstat ? "up" : "down");
238 ifi->linkstat = interface_link_status(ifi->name);
239 if (ifi->linkstat) {
240 client->state = S_INIT;
241 state_reboot();
242 }
243 }
244 break;
245 case RTM_IFANNOUNCE:
246 ifan = (struct if_announcemsghdr *)rtm;
247 if (ifan->ifan_what == IFAN_DEPARTURE &&
44967127
AHJ
248 ifan->ifan_index == ifi->index) {
249 errmsg = "interface departure";
846204b6 250 goto die;
44967127 251 }
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252 break;
253 default:
254 break;
255 }
256 return;
257
258die:
259 script_init("FAIL", NULL);
260 if (client->alias)
261 script_write_params("alias_", client->alias);
262 script_go();
44967127 263 error("routehandler: %s", errmsg);
846204b6
HT
264}
265
266int
267main(int argc, char *argv[])
268{
269 int ch, fd, quiet = 0, i = 0, pipe_fd[2];
270 struct passwd *pw;
271
272 /* Initially, log errors to stderr as well as to syslogd. */
273 openlog(getprogname(), LOG_PID | LOG_NDELAY, DHCPD_LOG_FACILITY);
274 setlogmask(LOG_UPTO(LOG_INFO));
275
276 while ((ch = getopt(argc, argv, "c:dl:qu")) != -1)
277 switch (ch) {
278 case 'c':
279 path_dhclient_conf = optarg;
280 break;
281 case 'd':
282 no_daemon = 1;
283 break;
284 case 'l':
285 path_dhclient_db = optarg;
286 break;
287 case 'q':
288 quiet = 1;
289 break;
290 case 'u':
291 unknown_ok = 0;
292 break;
293 default:
294 usage();
295 }
296
297 argc -= optind;
298 argv += optind;
299
300 if (argc != 1)
301 usage();
302
303 ifi = calloc(1, sizeof(*ifi));
304 if (ifi == NULL)
305 error("ifi calloc");
306 client = calloc(1, sizeof(*client));
307 if (client == NULL)
308 error("client calloc");
309 config = calloc(1, sizeof(*config));
310 if (config == NULL)
311 error("config calloc");
312
313 if (strlcpy(ifi->name, argv[0], IFNAMSIZ) >= IFNAMSIZ)
314 error("Interface name too long");
315 if (path_dhclient_db == NULL && asprintf(&path_dhclient_db, "%s.%s",
316 _PATH_DHCLIENT_DB, ifi->name) == -1)
317 error("asprintf");
318
319 if (quiet)
320 log_perror = 0;
321
322 tzset();
323 time(&cur_time);
324
325 memset(&sockaddr_broadcast, 0, sizeof(sockaddr_broadcast));
326 sockaddr_broadcast.sin_family = AF_INET;
327 sockaddr_broadcast.sin_port = htons(REMOTE_PORT);
328 sockaddr_broadcast.sin_addr.s_addr = INADDR_BROADCAST;
329 sockaddr_broadcast.sin_len = sizeof(sockaddr_broadcast);
330 inaddr_any.s_addr = INADDR_ANY;
331
332 read_client_conf();
333
334 if (interface_status(ifi->name) == 0) {
335 interface_link_forceup(ifi->name);
336 /* Give it up to 4 seconds of silent grace to find link */
337 i = -4;
338 } else
339 i = 0;
340
341 while (!(ifi->linkstat = interface_link_status(ifi->name))) {
342 if (i == 0)
343 fprintf(stderr, "%s: no link ...", ifi->name);
344 else if (i > 0)
345 fprintf(stderr, ".");
346 fflush(stderr);
347 if (++i > config->link_timeout) {
348 fprintf(stderr, " sleeping\n");
349 goto dispatch;
350 }
351 sleep(1);
846204b6 352 }
ade429c6 353 if (i > 0)
77a69a5f 354 fprintf(stderr, " got link\n");
846204b6
HT
355
356 dispatch:
357 if ((nullfd = open(_PATH_DEVNULL, O_RDWR, 0)) == -1)
358 error("cannot open %s: %m", _PATH_DEVNULL);
359
38623c79
AHJ
360 if ((pw = getpwnam("_dhcp")) == NULL)
361 error("no such user: _dhcp");
846204b6
HT
362
363 if (pipe(pipe_fd) == -1)
364 error("pipe");
365
366 fork_privchld(pipe_fd[0], pipe_fd[1]);
367
368 close(pipe_fd[0]);
369 privfd = pipe_fd[1];
370
371 if ((fd = open(path_dhclient_db, O_RDONLY|O_EXLOCK|O_CREAT, 0)) == -1)
372 error("can't open and lock %s: %m", path_dhclient_db);
373 read_client_leases();
374 if ((leaseFile = fopen(path_dhclient_db, "w")) == NULL)
375 error("can't open %s: %m", path_dhclient_db);
376 rewrite_client_leases();
377 close(fd);
378
379 priv_script_init("PREINIT", NULL);
380 if (client->alias)
381 priv_script_write_params("alias_", client->alias);
382 priv_script_go();
383
384 if ((routefd = socket(PF_ROUTE, SOCK_RAW, 0)) == -1)
385 error("socket(PF_ROUTE, SOCK_RAW): %m");
386
387 /* set up the interface */
388 discover_interface();
389
390 if (chroot(_PATH_VAREMPTY) == -1)
391 error("chroot");
392 if (chdir("/") == -1)
393 error("chdir(\"/\")");
394
395 if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1)
396 error("setresgid");
397 if (setgroups(1, &pw->pw_gid) == -1)
398 error("setgroups");
399 if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1)
400 error("setresuid");
401
402 endpwent();
403
404 setproctitle("%s", ifi->name);
405
406 if (ifi->linkstat) {
407 client->state = S_INIT;
408 state_reboot();
409 } else
410 go_daemon();
411
412 dispatch();
413
414 /* not reached */
415 return (0);
416}
417
418void
419usage(void)
420{
421 fprintf(stderr, "usage: %s [-dqu] [-c file] [-l file] interface\n",
422 getprogname());
423 exit(1);
424}
425
426/*
427 * Individual States:
428 *
429 * Each routine is called from the dhclient_state_machine() in one of
430 * these conditions:
431 * -> entering INIT state
432 * -> recvpacket_flag == 0: timeout in this state
433 * -> otherwise: received a packet in this state
434 *
435 * Return conditions as handled by dhclient_state_machine():
436 * Returns 1, sendpacket_flag = 1: send packet, reset timer.
437 * Returns 1, sendpacket_flag = 0: just reset the timer (wait for a milestone).
438 * Returns 0: finish the nap which was interrupted for no good reason.
439 *
440 * Several per-interface variables are used to keep track of the process:
441 * active_lease: the lease that is being used on the interface
442 * (null pointer if not configured yet).
443 * offered_leases: leases corresponding to DHCPOFFER messages that have
444 * been sent to us by DHCP servers.
445 * acked_leases: leases corresponding to DHCPACK messages that have been
446 * sent to us by DHCP servers.
447 * sendpacket: DHCP packet we're trying to send.
448 * destination: IP address to send sendpacket to
449 * In addition, there are several relevant per-lease variables.
450 * T1_expiry, T2_expiry, lease_expiry: lease milestones
451 * In the active lease, these control the process of renewing the lease;
452 * In leases on the acked_leases list, this simply determines when we
453 * can no longer legitimately use the lease.
454 */
455void
456state_reboot(void)
457{
458 /* If we don't remember an active lease, go straight to INIT. */
459 if (!client->active || client->active->is_bootp) {
460 state_init();
461 return;
462 }
463
464 /* We are in the rebooting state. */
465 client->state = S_REBOOTING;
466
467 /* make_request doesn't initialize xid because it normally comes
468 from the DHCPDISCOVER, but we haven't sent a DHCPDISCOVER,
469 so pick an xid now. */
470 client->xid = arc4random();
471
472 /* Make a DHCPREQUEST packet, and set appropriate per-interface
473 flags. */
474 make_request(client->active);
475 client->destination = iaddr_broadcast;
476 client->first_sending = cur_time;
477 client->interval = config->initial_interval;
478
479 /* Zap the medium list... */
480 client->medium = NULL;
481
482 /* Send out the first DHCPREQUEST packet. */
483 send_request();
484}
485
486/*
487 * Called when a lease has completely expired and we've
488 * been unable to renew it.
489 */
490void
491state_init(void)
492{
493 /* Make a DHCPDISCOVER packet, and set appropriate per-interface
494 flags. */
495 make_discover(client->active);
496 client->xid = client->packet.xid;
497 client->destination = iaddr_broadcast;
498 client->state = S_SELECTING;
499 client->first_sending = cur_time;
500 client->interval = config->initial_interval;
501
502 /* Add an immediate timeout to cause the first DHCPDISCOVER packet
503 to go out. */
504 send_discover();
505}
506
507/*
508 * state_selecting is called when one or more DHCPOFFER packets
509 * have been received and a configurable period of time has passed.
510 */
511void
512state_selecting(void)
513{
514 struct client_lease *lp, *next, *picked;
515
516 /* Cancel state_selecting and send_discover timeouts, since either
517 one could have got us here. */
518 cancel_timeout(state_selecting);
519 cancel_timeout(send_discover);
520
521 /* We have received one or more DHCPOFFER packets. Currently,
522 the only criterion by which we judge leases is whether or
523 not we get a response when we arp for them. */
524 picked = NULL;
525 for (lp = client->offered_leases; lp; lp = next) {
526 next = lp->next;
527
528 /* Check to see if we got an ARPREPLY for the address
529 in this particular lease. */
530 if (!picked) {
531 script_init("ARPCHECK", lp->medium);
532 script_write_params("check_", lp);
533
534 /* If the ARPCHECK code detects another
535 machine using the offered address, it exits
536 nonzero. We need to send a DHCPDECLINE and
537 toss the lease. */
538 if (script_go()) {
539 make_decline(lp);
540 send_decline();
541 goto freeit;
542 }
543 picked = lp;
544 picked->next = NULL;
545 } else {
546freeit:
547 free_client_lease(lp);
548 }
549 }
550 client->offered_leases = NULL;
551
552 /* If we just tossed all the leases we were offered, go back
553 to square one. */
554 if (!picked) {
555 client->state = S_INIT;
556 state_init();
557 return;
558 }
559
560 /* If it was a BOOTREPLY, we can just take the address right now. */
561 if (!picked->options[DHO_DHCP_MESSAGE_TYPE].len) {
562 client->new = picked;
563
564 /* Make up some lease expiry times
565 XXX these should be configurable. */
566 client->new->expiry = cur_time + 12000;
567 client->new->renewal += cur_time + 8000;
568 client->new->rebind += cur_time + 10000;
569
570 client->state = S_REQUESTING;
571
572 /* Bind to the address we received. */
573 bind_lease();
574 return;
575 }
576
577 /* Go to the REQUESTING state. */
578 client->destination = iaddr_broadcast;
579 client->state = S_REQUESTING;
580 client->first_sending = cur_time;
581 client->interval = config->initial_interval;
582
583 /* Make a DHCPREQUEST packet from the lease we picked. */
584 make_request(picked);
585 client->xid = client->packet.xid;
586
587 /* Toss the lease we picked - we'll get it back in a DHCPACK. */
588 free_client_lease(picked);
589
590 /* Add an immediate timeout to send the first DHCPREQUEST packet. */
591 send_request();
592}
593
594void
595dhcpack(struct iaddr client_addr, struct option_data *options)
596{
597 struct client_lease *lease;
598
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HT
599
600 if (client->state != S_REBOOTING &&
601 client->state != S_REQUESTING &&
602 client->state != S_RENEWING &&
603 client->state != S_REBINDING)
604 return;
605
846204b6
HT
606
607 lease = packet_to_lease(options);
608 if (!lease) {
609 note("packet_to_lease failed.");
610 return;
611 }
612
613 client->new = lease;
614
615 /* Stop resending DHCPREQUEST. */
616 cancel_timeout(send_request);
617
618 /* Figure out the lease time. */
619 if (client->new->options[DHO_DHCP_LEASE_TIME].data)
620 client->new->expiry =
621 getULong(client->new->options[DHO_DHCP_LEASE_TIME].data);
622 else
623 client->new->expiry = DEFAULT_LEASE_TIME;
624 /* A number that looks negative here is really just very large,
625 because the lease expiry offset is unsigned. */
626 if (client->new->expiry < 0)
627 client->new->expiry = TIME_MAX;
628 /* XXX should be fixed by resetting the client state */
629 if (client->new->expiry < 60)
630 client->new->expiry = 60;
631
632 /* Take the server-provided renewal time if there is one;
633 otherwise figure it out according to the spec. */
634 if (client->new->options[DHO_DHCP_RENEWAL_TIME].len)
635 client->new->renewal =
636 getULong(client->new->options[DHO_DHCP_RENEWAL_TIME].data);
637 else
638 client->new->renewal = client->new->expiry / 2;
639
640 /* Same deal with the rebind time. */
641 if (client->new->options[DHO_DHCP_REBINDING_TIME].len)
642 client->new->rebind =
643 getULong(client->new->options[DHO_DHCP_REBINDING_TIME].data);
644 else
645 client->new->rebind = client->new->renewal +
646 client->new->renewal / 2 + client->new->renewal / 4;
647
648 client->new->expiry += cur_time;
649 /* Lease lengths can never be negative. */
650 if (client->new->expiry < cur_time)
651 client->new->expiry = TIME_MAX;
652 client->new->renewal += cur_time;
653 if (client->new->renewal < cur_time)
654 client->new->renewal = TIME_MAX;
655 client->new->rebind += cur_time;
656 if (client->new->rebind < cur_time)
657 client->new->rebind = TIME_MAX;
658
659 bind_lease();
660}
661
662void
663bind_lease(void)
664{
665 /* Remember the medium. */
666 client->new->medium = client->medium;
667
668 /* Write out the new lease. */
669 write_client_lease(client->new, 0);
670
671 /* Run the client script with the new parameters. */
672 script_init((client->state == S_REQUESTING ? "BOUND" :
673 (client->state == S_RENEWING ? "RENEW" :
674 (client->state == S_REBOOTING ? "REBOOT" : "REBIND"))),
675 client->new->medium);
676 if (client->active && client->state != S_REBOOTING)
677 script_write_params("old_", client->active);
678 script_write_params("new_", client->new);
679 if (client->alias)
680 script_write_params("alias_", client->alias);
681 script_go();
682
683 /* Replace the old active lease with the new one. */
684 if (client->active)
685 free_client_lease(client->active);
686 client->active = client->new;
687 client->new = NULL;
688
689 /* Set up a timeout to start the renewal process. */
690 add_timeout(client->active->renewal, state_bound);
691
692 note("bound to %s -- renewal in %ld seconds.",
693 piaddr(client->active->address),
694 client->active->renewal - cur_time);
695 client->state = S_BOUND;
696 reinitialize_interface();
697 go_daemon();
698}
699
700/*
701 * state_bound is called when we've successfully bound to a particular
702 * lease, but the renewal time on that lease has expired. We are
703 * expected to unicast a DHCPREQUEST to the server that gave us our
704 * original lease.
705 */
706void
707state_bound(void)
708{
709 /* T1 has expired. */
710 make_request(client->active);
711 client->xid = client->packet.xid;
712
713 if (client->active->options[DHO_DHCP_SERVER_IDENTIFIER].len == 4) {
714 memcpy(client->destination.iabuf,
715 client->active->options[DHO_DHCP_SERVER_IDENTIFIER].data,
716 4);
717 client->destination.len = 4;
718 } else
719 client->destination = iaddr_broadcast;
720
721 client->first_sending = cur_time;
722 client->interval = config->initial_interval;
723 client->state = S_RENEWING;
724
725 /* Send the first packet immediately. */
726 send_request();
727}
728
729void
730dhcpoffer(struct iaddr client_addr, struct option_data *options)
731{
732 struct client_lease *lease, *lp;
733 int i;
734 int arp_timeout_needed, stop_selecting;
735 char *name = options[DHO_DHCP_MESSAGE_TYPE].len ? "DHCPOFFER" :
736 "BOOTREPLY";
737
846204b6
HT
738
739 if (client->state != S_SELECTING)
740 return;
741
846204b6
HT
742
743 /* If this lease doesn't supply the minimum required parameters,
744 blow it off. */
745 for (i = 0; config->required_options[i]; i++) {
746 if (!options[config->required_options[i]].len) {
747 note("%s isn't satisfactory.", name);
748 return;
749 }
750 }
751
752 /* If we've already seen this lease, don't record it again. */
753 for (lease = client->offered_leases;
754 lease; lease = lease->next) {
755 if (lease->address.len == sizeof(client->packet.yiaddr) &&
756 !memcmp(lease->address.iabuf,
757 &client->packet.yiaddr, lease->address.len)) {
758 debug("%s already seen.", name);
759 return;
760 }
761 }
762
763 lease = packet_to_lease(options);
764 if (!lease) {
765 note("packet_to_lease failed.");
766 return;
767 }
768
769 /* If this lease was acquired through a BOOTREPLY, record that
770 fact. */
771 if (!options[DHO_DHCP_MESSAGE_TYPE].len)
772 lease->is_bootp = 1;
773
774 /* Record the medium under which this lease was offered. */
775 lease->medium = client->medium;
776
777 /* Send out an ARP Request for the offered IP address. */
778 script_init("ARPSEND", lease->medium);
779 script_write_params("check_", lease);
780 /* If the script can't send an ARP request without waiting,
781 we'll be waiting when we do the ARPCHECK, so don't wait now. */
782 if (script_go())
783 arp_timeout_needed = 0;
784 else
785 arp_timeout_needed = 2;
786
787 /* Figure out when we're supposed to stop selecting. */
788 stop_selecting = client->first_sending + config->select_interval;
789
790 /* If this is the lease we asked for, put it at the head of the
791 list, and don't mess with the arp request timeout. */
792 if (lease->address.len == client->requested_address.len &&
793 !memcmp(lease->address.iabuf,
794 client->requested_address.iabuf,
795 client->requested_address.len)) {
796 lease->next = client->offered_leases;
797 client->offered_leases = lease;
798 } else {
799 /* If we already have an offer, and arping for this
800 offer would take us past the selection timeout,
801 then don't extend the timeout - just hope for the
802 best. */
803 if (client->offered_leases &&
804 (cur_time + arp_timeout_needed) > stop_selecting)
805 arp_timeout_needed = 0;
806
807 /* Put the lease at the end of the list. */
808 lease->next = NULL;
809 if (!client->offered_leases)
810 client->offered_leases = lease;
811 else {
812 for (lp = client->offered_leases; lp->next;
813 lp = lp->next)
814 ; /* nothing */
815 lp->next = lease;
816 }
817 }
818
819 /* If we're supposed to stop selecting before we've had time
820 to wait for the ARPREPLY, add some delay to wait for
821 the ARPREPLY. */
822 if (stop_selecting - cur_time < arp_timeout_needed)
823 stop_selecting = cur_time + arp_timeout_needed;
824
825 /* If the selecting interval has expired, go immediately to
826 state_selecting(). Otherwise, time out into
827 state_selecting at the select interval. */
828 if (stop_selecting <= 0)
829 state_selecting();
830 else {
831 add_timeout(stop_selecting, state_selecting);
832 cancel_timeout(send_discover);
833 }
834}
835
836/*
837 * Allocate a client_lease structure and initialize it from the
838 * parameters in the specified packet.
839 */
840struct client_lease *
841packet_to_lease(struct option_data *options)
842{
843 struct client_lease *lease;
844 int i;
845
846 lease = malloc(sizeof(struct client_lease));
847
848 if (!lease) {
849 warning("dhcpoffer: no memory to record lease.");
850 return (NULL);
851 }
852
853 memset(lease, 0, sizeof(*lease));
854
855 /* Copy the lease options. */
856 for (i = 0; i < 256; i++) {
857 if (options[i].len) {
858 lease->options[i] = options[i];
859 options[i].data = NULL;
860 options[i].len = 0;
861 if (!check_option(lease, i)) {
862 warning("Invalid lease option - ignoring offer");
863 free_client_lease(lease);
864 return (NULL);
865 }
866 }
867 }
868
869 lease->address.len = sizeof(client->packet.yiaddr);
870 memcpy(lease->address.iabuf, &client->packet.yiaddr,
871 lease->address.len);
872
873 /* If the server name was filled out, copy it. */
874 if ((!lease->options[DHO_DHCP_OPTION_OVERLOAD].len ||
875 !(lease->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 2)) &&
876 client->packet.sname[0]) {
877 lease->server_name = malloc(DHCP_SNAME_LEN + 1);
878 if (!lease->server_name) {
879 warning("dhcpoffer: no memory for server name.");
880 free_client_lease(lease);
881 return (NULL);
882 }
883 memcpy(lease->server_name, client->packet.sname,
884 DHCP_SNAME_LEN);
885 lease->server_name[DHCP_SNAME_LEN] = '\0';
886 if (!res_hnok(lease->server_name)) {
887 warning("Bogus server name %s", lease->server_name);
888 free(lease->server_name);
889 lease->server_name = NULL;
890 }
891 }
892
893 /* Ditto for the filename. */
894 if ((!lease->options[DHO_DHCP_OPTION_OVERLOAD].len ||
895 !(lease->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 1)) &&
896 client->packet.file[0]) {
897 /* Don't count on the NUL terminator. */
898 lease->filename = malloc(DHCP_FILE_LEN + 1);
899 if (!lease->filename) {
900 warning("dhcpoffer: no memory for filename.");
901 free_client_lease(lease);
902 return (NULL);
903 }
904 memcpy(lease->filename, client->packet.file, DHCP_FILE_LEN);
905 lease->filename[DHCP_FILE_LEN] = '\0';
906 }
907 return lease;
908}
909
910void
911dhcpnak(struct iaddr client_addr, struct option_data *options)
912{
846204b6
HT
913
914 if (client->state != S_REBOOTING &&
915 client->state != S_REQUESTING &&
916 client->state != S_RENEWING &&
917 client->state != S_REBINDING)
918 return;
919
846204b6
HT
920
921 if (!client->active) {
922 note("DHCPNAK with no active lease.");
923 return;
924 }
925
926 free_client_lease(client->active);
927 client->active = NULL;
928
929 /* Stop sending DHCPREQUEST packets... */
930 cancel_timeout(send_request);
931
932 client->state = S_INIT;
933 state_init();
934}
935
936/*
937 * Send out a DHCPDISCOVER packet, and set a timeout to send out another
938 * one after the right interval has expired. If we don't get an offer by
939 * the time we reach the panic interval, call the panic function.
940 */
941void
942send_discover(void)
943{
944 int interval, increase = 1;
945
946 /* Figure out how long it's been since we started transmitting. */
947 interval = cur_time - client->first_sending;
948
949 /* If we're past the panic timeout, call the script and tell it
950 we haven't found anything for this interface yet. */
951 if (interval > config->timeout) {
952 state_panic();
953 return;
954 }
955
956 /* If we're selecting media, try the whole list before doing
957 the exponential backoff, but if we've already received an
958 offer, stop looping, because we obviously have it right. */
959 if (!client->offered_leases && config->media) {
960 int fail = 0;
961again:
962 if (client->medium) {
963 client->medium = client->medium->next;
964 increase = 0;
965 }
966 if (!client->medium) {
967 if (fail)
968 error("No valid media types for %s!", ifi->name);
969 client->medium = config->media;
970 increase = 1;
971 }
972
973 note("Trying medium \"%s\" %d", client->medium->string,
974 increase);
975 script_init("MEDIUM", client->medium);
976 if (script_go())
977 goto again;
978 }
979
980 /*
981 * If we're supposed to increase the interval, do so. If it's
982 * currently zero (i.e., we haven't sent any packets yet), set
983 * it to initial_interval; otherwise, add to it a random
984 * number between zero and two times itself. On average, this
985 * means that it will double with every transmission.
986 */
987 if (increase) {
988 if (!client->interval)
989 client->interval = config->initial_interval;
990 else {
991 client->interval += (arc4random() >> 2) %
992 (2 * client->interval);
993 }
994
995 /* Don't backoff past cutoff. */
996 if (client->interval > config->backoff_cutoff)
997 client->interval = ((config->backoff_cutoff / 2)
998 + ((arc4random() >> 2) %
999 config->backoff_cutoff));
1000 } else if (!client->interval)
1001 client->interval = config->initial_interval;
1002
1003 /* If the backoff would take us to the panic timeout, just use that
1004 as the interval. */
1005 if (cur_time + client->interval >
1006 client->first_sending + config->timeout)
1007 client->interval = (client->first_sending +
1008 config->timeout) - cur_time + 1;
1009
1010 /* Record the number of seconds since we started sending. */
1011 if (interval < 65536)
1012 client->packet.secs = htons(interval);
1013 else
1014 client->packet.secs = htons(65535);
1015 client->secs = client->packet.secs;
1016
1017 note("DHCPDISCOVER on %s to %s port %d interval %ld",
1018 ifi->name, inet_ntoa(sockaddr_broadcast.sin_addr),
1019 ntohs(sockaddr_broadcast.sin_port), client->interval);
1020
1021 /* Send out a packet. */
1022 send_packet(inaddr_any, &sockaddr_broadcast, NULL);
1023
1024 add_timeout(cur_time + client->interval, send_discover);
1025}
1026
1027/*
1028 * state_panic gets called if we haven't received any offers in a preset
1029 * amount of time. When this happens, we try to use existing leases
1030 * that haven't yet expired, and failing that, we call the client script
1031 * and hope it can do something.
1032 */
1033void
1034state_panic(void)
1035{
1036 struct client_lease *loop = client->active;
1037 struct client_lease *lp;
1038
1039 note("No DHCPOFFERS received.");
1040
1041 /* We may not have an active lease, but we may have some
1042 predefined leases that we can try. */
1043 if (!client->active && client->leases)
1044 goto activate_next;
1045
1046 /* Run through the list of leases and see if one can be used. */
1047 while (client->active) {
1048 if (client->active->expiry > cur_time) {
1049 note("Trying recorded lease %s",
1050 piaddr(client->active->address));
1051 /* Run the client script with the existing
1052 parameters. */
1053 script_init("TIMEOUT",
1054 client->active->medium);
1055 script_write_params("new_", client->active);
1056 if (client->alias)
1057 script_write_params("alias_",
1058 client->alias);
1059
1060 /* If the old lease is still good and doesn't
1061 yet need renewal, go into BOUND state and
1062 timeout at the renewal time. */
1063 if (!script_go()) {
1064 if (cur_time <
1065 client->active->renewal) {
1066 client->state = S_BOUND;
1067 note("bound: renewal in %ld seconds.",
1068 client->active->renewal -
1069 cur_time);
1070 add_timeout(client->active->renewal,
1071 state_bound);
1072 } else {
1073 client->state = S_BOUND;
1074 note("bound: immediate renewal.");
1075 state_bound();
1076 }
1077 reinitialize_interface();
1078 go_daemon();
1079 return;
1080 }
1081 }
1082
1083 /* If there are no other leases, give up. */
1084 if (!client->leases) {
1085 client->leases = client->active;
1086 client->active = NULL;
1087 break;
1088 }
1089
1090activate_next:
1091 /* Otherwise, put the active lease at the end of the
1092 lease list, and try another lease.. */
1093 for (lp = client->leases; lp->next; lp = lp->next)
1094 ;
1095 lp->next = client->active;
1096 if (lp->next)
1097 lp->next->next = NULL;
1098 client->active = client->leases;
1099 client->leases = client->leases->next;
1100
1101 /* If we already tried this lease, we've exhausted the
1102 set of leases, so we might as well give up for
1103 now. */
1104 if (client->active == loop)
1105 break;
1106 else if (!loop)
1107 loop = client->active;
1108 }
1109
1110 /* No leases were available, or what was available didn't work, so
1111 tell the shell script that we failed to allocate an address,
1112 and try again later. */
1113 note("No working leases in persistent database - sleeping.");
1114 script_init("FAIL", NULL);
1115 if (client->alias)
1116 script_write_params("alias_", client->alias);
1117 script_go();
1118 client->state = S_INIT;
1119 add_timeout(cur_time + config->retry_interval, state_init);
1120 go_daemon();
1121}
1122
1123void
1124send_request(void)
1125{
1126 struct sockaddr_in destination;
1127 struct in_addr from;
1128 int interval;
1129
1130 /* Figure out how long it's been since we started transmitting. */
1131 interval = cur_time - client->first_sending;
1132
1133 /* If we're in the INIT-REBOOT or REQUESTING state and we're
1134 past the reboot timeout, go to INIT and see if we can
1135 DISCOVER an address... */
1136 /* XXX In the INIT-REBOOT state, if we don't get an ACK, it
1137 means either that we're on a network with no DHCP server,
1138 or that our server is down. In the latter case, assuming
1139 that there is a backup DHCP server, DHCPDISCOVER will get
1140 us a new address, but we could also have successfully
1141 reused our old address. In the former case, we're hosed
1142 anyway. This is not a win-prone situation. */
1143 if ((client->state == S_REBOOTING ||
1144 client->state == S_REQUESTING) &&
1145 interval > config->reboot_timeout) {
1146cancel:
1147 client->state = S_INIT;
1148 cancel_timeout(send_request);
1149 state_init();
1150 return;
1151 }
1152
1153 /* If we're in the reboot state, make sure the media is set up
1154 correctly. */
1155 if (client->state == S_REBOOTING &&
1156 !client->medium &&
1157 client->active->medium) {
1158 script_init("MEDIUM", client->active->medium);
1159
1160 /* If the medium we chose won't fly, go to INIT state. */
1161 if (script_go())
1162 goto cancel;
1163
1164 /* Record the medium. */
1165 client->medium = client->active->medium;
1166 }
1167
1168 /* If the lease has expired, relinquish the address and go back
1169 to the INIT state. */
1170 if (client->state != S_REQUESTING &&
1171 cur_time > client->active->expiry) {
1172 /* Run the client script with the new parameters. */
1173 script_init("EXPIRE", NULL);
1174 script_write_params("old_", client->active);
1175 if (client->alias)
1176 script_write_params("alias_", client->alias);
1177 script_go();
1178
1179 /* Now do a preinit on the interface so that we can
1180 discover a new address. */
1181 script_init("PREINIT", NULL);
1182 if (client->alias)
1183 script_write_params("alias_", client->alias);
1184 script_go();
1185
1186 client->state = S_INIT;
1187 state_init();
1188 return;
1189 }
1190
1191 /* Do the exponential backoff... */
1192 if (!client->interval)
1193 client->interval = config->initial_interval;
1194 else
1195 client->interval += ((arc4random() >> 2) %
1196 (2 * client->interval));
1197
1198 /* Don't backoff past cutoff. */
1199 if (client->interval > config->backoff_cutoff)
1200 client->interval = ((config->backoff_cutoff / 2) +
1201 ((arc4random() >> 2) % client->interval));
1202
1203 /* If the backoff would take us to the expiry time, just set the
1204 timeout to the expiry time. */
1205 if (client->state != S_REQUESTING && cur_time + client->interval >
1206 client->active->expiry)
1207 client->interval = client->active->expiry - cur_time + 1;
1208
1209 /* If the lease T2 time has elapsed, or if we're not yet bound,
1210 broadcast the DHCPREQUEST rather than unicasting. */
1211 memset(&destination, 0, sizeof(destination));
1212 if (client->state == S_REQUESTING ||
1213 client->state == S_REBOOTING ||
1214 cur_time > client->active->rebind)
1215 destination.sin_addr.s_addr = INADDR_BROADCAST;
1216 else
1217 memcpy(&destination.sin_addr.s_addr, client->destination.iabuf,
1218 sizeof(destination.sin_addr.s_addr));
1219 destination.sin_port = htons(REMOTE_PORT);
1220 destination.sin_family = AF_INET;
1221 destination.sin_len = sizeof(destination);
1222
1223 if (client->state != S_REQUESTING)
1224 memcpy(&from, client->active->address.iabuf, sizeof(from));
1225 else
1226 from.s_addr = INADDR_ANY;
1227
1228 /* Record the number of seconds since we started sending. */
1229 if (client->state == S_REQUESTING)
1230 client->packet.secs = client->secs;
1231 else {
1232 if (interval < 65536)
1233 client->packet.secs = htons(interval);
1234 else
1235 client->packet.secs = htons(65535);
1236 }
1237
1238 note("DHCPREQUEST on %s to %s port %d", ifi->name,
1239 inet_ntoa(destination.sin_addr), ntohs(destination.sin_port));
1240
1241 /* Send out a packet. */
1242 send_packet(from, &destination, NULL);
1243
1244 add_timeout(cur_time + client->interval, send_request);
1245}
1246
1247void
1248send_decline(void)
1249{
1250 note("DHCPDECLINE on %s to %s port %d", ifi->name,
1251 inet_ntoa(sockaddr_broadcast.sin_addr),
1252 ntohs(sockaddr_broadcast.sin_port));
1253
1254 /* Send out a packet. */
1255 send_packet(inaddr_any, &sockaddr_broadcast, NULL);
1256}
1257
1258void
1259make_discover(struct client_lease *lease)
1260{
1261 unsigned char discover = DHCPDISCOVER;
1262 struct option_data options[256];
1263 int i;
1264
1265 memset(options, 0, sizeof(options));
1266 memset(&client->packet, 0, sizeof(client->packet));
1267
1268 /* Set DHCP_MESSAGE_TYPE to DHCPDISCOVER */
1269 i = DHO_DHCP_MESSAGE_TYPE;
1270 options[i].data = &discover;
1271 options[i].len = sizeof(discover);
1272
1273 /* Request the options we want */
1274 i = DHO_DHCP_PARAMETER_REQUEST_LIST;
1275 options[i].data = config->requested_options;
1276 options[i].len = config->requested_option_count;
1277
1278 /* If we had an address, try to get it again. */
1279 if (lease) {
1280 client->requested_address = lease->address;
1281 i = DHO_DHCP_REQUESTED_ADDRESS;
1282 options[i].data = lease->address.iabuf;
1283 options[i].len = lease->address.len;
1284 } else
1285 client->requested_address.len = 0;
1286
1287 /* Send any options requested in the config file. */
1288 for (i = 0; i < 256; i++)
1289 if (!options[i].data &&
1290 config->send_options[i].data) {
1291 options[i].data = config->send_options[i].data;
1292 options[i].len = config->send_options[i].len;
1293 }
1294
1295 /* Set up the option buffer to fit in a minimal UDP packet. */
1296 i = cons_options(client->packet.options, 576 - DHCP_FIXED_LEN,
1297 options);
1298 if (i == -1 || client->packet.options[i] != DHO_END)
1299 error("options do not fit in DHCPDISCOVER packet.");
1300 client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1301 if (client->packet_length < BOOTP_MIN_LEN)
1302 client->packet_length = BOOTP_MIN_LEN;
1303
1304 client->packet.op = BOOTREQUEST;
1305 client->packet.htype = ifi->hw_address.htype;
1306 client->packet.hlen = ifi->hw_address.hlen;
1307 client->packet.hops = 0;
1308 client->packet.xid = arc4random();
1309 client->packet.secs = 0; /* filled in by send_discover. */
1310 client->packet.flags = 0;
1311
1312 memset(&client->packet.ciaddr, 0, sizeof(client->packet.ciaddr));
1313 memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1314 memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1315 memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1316 memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1317 ifi->hw_address.hlen);
1318}
1319
1320void
1321make_request(struct client_lease * lease)
1322{
1323 unsigned char request = DHCPREQUEST;
1324 struct option_data options[256];
1325 int i;
1326
1327 memset(options, 0, sizeof(options));
1328 memset(&client->packet, 0, sizeof(client->packet));
1329
1330 /* Set DHCP_MESSAGE_TYPE to DHCPREQUEST */
1331 i = DHO_DHCP_MESSAGE_TYPE;
1332 options[i].data = &request;
1333 options[i].len = sizeof(request);
1334
1335 /* Request the options we want */
1336 i = DHO_DHCP_PARAMETER_REQUEST_LIST;
1337 options[i].data = config->requested_options;
1338 options[i].len = config->requested_option_count;
1339
1340 /* If we are requesting an address that hasn't yet been assigned
1341 to us, use the DHCP Requested Address option. */
1342 if (client->state == S_REQUESTING) {
1343 /* Send back the server identifier... */
1344 i = DHO_DHCP_SERVER_IDENTIFIER;
1345 options[i].data = lease->options[i].data;
1346 options[i].len = lease->options[i].len;
1347 }
1348 if (client->state == S_REQUESTING ||
1349 client->state == S_REBOOTING) {
1350 client->requested_address = lease->address;
1351 i = DHO_DHCP_REQUESTED_ADDRESS;
1352 options[i].data = lease->address.iabuf;
1353 options[i].len = lease->address.len;
1354 } else
1355 client->requested_address.len = 0;
1356
1357 /* Send any options requested in the config file. */
1358 for (i = 0; i < 256; i++)
1359 if (!options[i].data && config->send_options[i].data) {
1360 options[i].data = config->send_options[i].data;
1361 options[i].len = config->send_options[i].len;
1362 }
1363
1364 /* Set up the option buffer to fit in a minimal UDP packet. */
1365 i = cons_options(client->packet.options, 576 - DHCP_FIXED_LEN,
1366 options);
1367 if (i == -1 || client->packet.options[i] != DHO_END)
1368 error("options do not fit in DHCPREQUEST packet.");
1369 client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1370 if (client->packet_length < BOOTP_MIN_LEN)
1371 client->packet_length = BOOTP_MIN_LEN;
1372
1373 client->packet.op = BOOTREQUEST;
1374 client->packet.htype = ifi->hw_address.htype;
1375 client->packet.hlen = ifi->hw_address.hlen;
1376 client->packet.hops = 0;
1377 client->packet.xid = client->xid;
1378 client->packet.secs = 0; /* Filled in by send_request. */
1379 client->packet.flags = 0;
1380
1381 /* If we own the address we're requesting, put it in ciaddr;
1382 otherwise set ciaddr to zero. */
1383 if (client->state == S_BOUND ||
1384 client->state == S_RENEWING ||
1385 client->state == S_REBINDING) {
1386 memcpy(&client->packet.ciaddr,
1387 lease->address.iabuf, lease->address.len);
1388 } else {
1389 memset(&client->packet.ciaddr, 0,
1390 sizeof(client->packet.ciaddr));
1391 }
1392
1393 memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1394 memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1395 memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1396 memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1397 ifi->hw_address.hlen);
1398}
1399
1400void
1401make_decline(struct client_lease *lease)
1402{
1403 struct option_data options[256];
1404 unsigned char decline = DHCPDECLINE;
1405 int i;
1406
1407 memset(options, 0, sizeof(options));
1408 memset(&client->packet, 0, sizeof(client->packet));
1409
1410 /* Set DHCP_MESSAGE_TYPE to DHCPDECLINE */
1411 i = DHO_DHCP_MESSAGE_TYPE;
1412 options[i].data = &decline;
1413 options[i].len = sizeof(decline);
1414
1415 /* Send back the server identifier... */
1416 i = DHO_DHCP_SERVER_IDENTIFIER;
1417 options[i].data = lease->options[i].data;
1418 options[i].len = lease->options[i].len;
1419
1420 /* Send back the address we're declining. */
1421 i = DHO_DHCP_REQUESTED_ADDRESS;
1422 options[i].data = lease->address.iabuf;
1423 options[i].len = lease->address.len;
1424
1425 /* Send the uid if the user supplied one. */
1426 i = DHO_DHCP_CLIENT_IDENTIFIER;
1427 if (config->send_options[i].len) {
1428 options[i].data = config->send_options[i].data;
1429 options[i].len = config->send_options[i].len;
1430 }
1431
1432 /* Set up the option buffer to fit in a minimal UDP packet. */
1433 i = cons_options(client->packet.options, 576 - DHCP_FIXED_LEN,
1434 options);
1435 if (i == -1 || client->packet.options[i] != DHO_END)
1436 error("options do not fit in DHCPDECLINE packet.");
1437 client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1438 if (client->packet_length < BOOTP_MIN_LEN)
1439 client->packet_length = BOOTP_MIN_LEN;
1440
1441 client->packet.op = BOOTREQUEST;
1442 client->packet.htype = ifi->hw_address.htype;
1443 client->packet.hlen = ifi->hw_address.hlen;
1444 client->packet.hops = 0;
1445 client->packet.xid = client->xid;
1446 client->packet.secs = 0; /* Filled in by send_request. */
1447 client->packet.flags = 0;
1448
1449 /* ciaddr must always be zero. */
1450 memset(&client->packet.ciaddr, 0, sizeof(client->packet.ciaddr));
1451 memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1452 memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1453 memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1454 memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1455 ifi->hw_address.hlen);
1456}
1457
1458void
1459free_client_lease(struct client_lease *lease)
1460{
1461 int i;
1462
1463 if (lease->server_name)
1464 free(lease->server_name);
1465 if (lease->filename)
1466 free(lease->filename);
1467 for (i = 0; i < 256; i++) {
1468 if (lease->options[i].len)
1469 free(lease->options[i].data);
1470 }
1471 free(lease);
1472}
1473
1474void
1475rewrite_client_leases(void)
1476{
1477 struct client_lease *lp;
1478
1479 if (!leaseFile) /* XXX */
1480 error("lease file not open");
1481
1482 fflush(leaseFile);
1483 rewind(leaseFile);
1484
1485 for (lp = client->leases; lp; lp = lp->next)
1486 write_client_lease(lp, 1);
1487 if (client->active)
1488 write_client_lease(client->active, 1);
1489
1490 fflush(leaseFile);
1491 ftruncate(fileno(leaseFile), ftello(leaseFile));
1492 fsync(fileno(leaseFile));
1493}
1494
1495void
1496write_client_lease(struct client_lease *lease, int rewrite)
1497{
1498 static int leases_written;
1499 struct tm *t;
1500 int i;
1501
1502 if (!rewrite) {
1503 if (leases_written++ > 20) {
1504 rewrite_client_leases();
1505 leases_written = 0;
1506 }
1507 }
1508
1509 /* If the lease came from the config file, we don't need to stash
1510 a copy in the lease database. */
1511 if (lease->is_static)
1512 return;
1513
1514 if (!leaseFile) /* XXX */
1515 error("lease file not open");
1516
1517 fprintf(leaseFile, "lease {\n");
1518 if (lease->is_bootp)
1519 fprintf(leaseFile, " bootp;\n");
1520 fprintf(leaseFile, " interface \"%s\";\n", ifi->name);
1521 fprintf(leaseFile, " fixed-address %s;\n", piaddr(lease->address));
1522 if (lease->filename)
1523 fprintf(leaseFile, " filename \"%s\";\n", lease->filename);
1524 if (lease->server_name)
1525 fprintf(leaseFile, " server-name \"%s\";\n",
1526 lease->server_name);
1527 if (lease->medium)
1528 fprintf(leaseFile, " medium \"%s\";\n", lease->medium->string);
1529 for (i = 0; i < 256; i++)
1530 if (lease->options[i].len)
1531 fprintf(leaseFile, " option %s %s;\n",
1532 dhcp_options[i].name,
1533 pretty_print_option(i, lease->options[i].data,
1534 lease->options[i].len, 1, 1));
1535
1536 t = gmtime(&lease->renewal);
1537 fprintf(leaseFile, " renew %d %d/%d/%d %02d:%02d:%02d;\n",
1538 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1539 t->tm_hour, t->tm_min, t->tm_sec);
1540 t = gmtime(&lease->rebind);
1541 fprintf(leaseFile, " rebind %d %d/%d/%d %02d:%02d:%02d;\n",
1542 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1543 t->tm_hour, t->tm_min, t->tm_sec);
1544 t = gmtime(&lease->expiry);
1545 fprintf(leaseFile, " expire %d %d/%d/%d %02d:%02d:%02d;\n",
1546 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1547 t->tm_hour, t->tm_min, t->tm_sec);
1548 fprintf(leaseFile, "}\n");
1549 fflush(leaseFile);
1550}
1551
1552void
1553script_init(char *reason, struct string_list *medium)
1554{
1555 size_t len, mediumlen = 0;
1556 struct imsg_hdr hdr;
1557 struct buf *buf;
1558
1559 if (medium != NULL && medium->string != NULL)
1560 mediumlen = strlen(medium->string);
1561
1562 hdr.code = IMSG_SCRIPT_INIT;
1563 hdr.len = sizeof(struct imsg_hdr) +
1564 sizeof(size_t) + mediumlen +
1565 sizeof(size_t) + strlen(reason);
1566
1567 buf = buf_open(hdr.len);
1568
1569 buf_add(buf, &hdr, sizeof(hdr));
1570 buf_add(buf, &mediumlen, sizeof(mediumlen));
1571 if (mediumlen > 0)
1572 buf_add(buf, medium->string, mediumlen);
1573 len = strlen(reason);
1574 buf_add(buf, &len, sizeof(len));
1575 buf_add(buf, reason, len);
1576
1577 buf_close(privfd, buf);
1578}
1579
1580void
1581priv_script_init(char *reason, char *medium)
1582{
1583 client->scriptEnvsize = 100;
1584 if (client->scriptEnv == NULL)
1585 client->scriptEnv =
1586 calloc(client->scriptEnvsize, sizeof(char *));
1587 if (client->scriptEnv == NULL)
1588 error("script_init: no memory for environment");
1589
1590 client->scriptEnv[0] = strdup(CLIENT_PATH);
1591 if (client->scriptEnv[0] == NULL)
1592 error("script_init: no memory for environment");
1593
1594 client->scriptEnv[1] = NULL;
1595
1596 script_set_env("", "interface", ifi->name);
1597
1598 if (medium)
1599 script_set_env("", "medium", medium);
1600
1601 script_set_env("", "reason", reason);
1602}
1603
1604void
1605priv_script_write_params(char *prefix, struct client_lease *lease)
1606{
1607 u_int8_t dbuf[1500];
1608 int i, len = 0;
1609 char tbuf[128];
1610
1611 script_set_env(prefix, "ip_address", piaddr(lease->address));
1612
1613 if (lease->options[DHO_SUBNET_MASK].len &&
1614 (lease->options[DHO_SUBNET_MASK].len <
1615 sizeof(lease->address.iabuf))) {
1616 struct iaddr netmask, subnet, broadcast;
1617
1618 memcpy(netmask.iabuf, lease->options[DHO_SUBNET_MASK].data,
1619 lease->options[DHO_SUBNET_MASK].len);
1620 netmask.len = lease->options[DHO_SUBNET_MASK].len;
1621
1622 subnet = subnet_number(lease->address, netmask);
1623 if (subnet.len) {
1624 script_set_env(prefix, "network_number",
1625 piaddr(subnet));
1626 if (!lease->options[DHO_BROADCAST_ADDRESS].len) {
1627 broadcast = broadcast_addr(subnet, netmask);
1628 if (broadcast.len)
1629 script_set_env(prefix,
1630 "broadcast_address",
1631 piaddr(broadcast));
1632 }
1633 }
1634 }
1635
1636 if (lease->filename)
1637 script_set_env(prefix, "filename", lease->filename);
1638 if (lease->server_name)
1639 script_set_env(prefix, "server_name",
1640 lease->server_name);
1641 for (i = 0; i < 256; i++) {
1642 u_int8_t *dp = NULL;
1643
1644 if (config->defaults[i].len) {
1645 if (lease->options[i].len) {
1646 switch (config->default_actions[i]) {
1647 case ACTION_DEFAULT:
1648 dp = lease->options[i].data;
1649 len = lease->options[i].len;
1650 break;
1651 case ACTION_SUPERSEDE:
1652supersede:
1653 dp = config->defaults[i].data;
1654 len = config->defaults[i].len;
1655 break;
1656 case ACTION_PREPEND:
1657 len = config->defaults[i].len +
1658 lease->options[i].len;
1659 if (len > sizeof(dbuf)) {
1660 warning("no space to %s %s",
1661 "prepend option",
1662 dhcp_options[i].name);
1663 goto supersede;
1664 }
1665 dp = dbuf;
1666 memcpy(dp,
1667 config->defaults[i].data,
1668 config->defaults[i].len);
1669 memcpy(dp +
1670 config->defaults[i].len,
1671 lease->options[i].data,
1672 lease->options[i].len);
1673 dp[len] = '\0';
1674 break;
1675 case ACTION_APPEND:
1676 len = config->defaults[i].len +
1677 lease->options[i].len;
1678 if (len > sizeof(dbuf)) {
1679 warning("no space to %s %s",
1680 "append option",
1681 dhcp_options[i].name);
1682 goto supersede;
1683 }
1684 dp = dbuf;
1685 memcpy(dp, lease->options[i].data,
1686 lease->options[i].len);
1687 memcpy(dp + lease->options[i].len,
1688 config->defaults[i].data,
1689 config->defaults[i].len);
1690 dp[len] = '\0';
1691 }
1692 } else {
1693 dp = config->defaults[i].data;
1694 len = config->defaults[i].len;
1695 }
1696 } else if (lease->options[i].len) {
1697 len = lease->options[i].len;
1698 dp = lease->options[i].data;
1699 } else {
1700 len = 0;
1701 }
1702 if (len) {
1703 char name[256];
1704
1705 if (dhcp_option_ev_name(name, sizeof(name),
1706 &dhcp_options[i]))
1707 script_set_env(prefix, name,
1708 pretty_print_option(i, dp, len, 0, 0));
1709 }
1710 }
1711 snprintf(tbuf, sizeof(tbuf), "%d", (int)lease->expiry);
1712 script_set_env(prefix, "expiry", tbuf);
1713}
1714
1715void
1716script_write_params(char *prefix, struct client_lease *lease)
1717{
1718 size_t fn_len = 0, sn_len = 0, pr_len = 0;
1719 struct imsg_hdr hdr;
1720 struct buf *buf;
1721 int i;
1722
1723 if (lease->filename != NULL)
1724 fn_len = strlen(lease->filename);
1725 if (lease->server_name != NULL)
1726 sn_len = strlen(lease->server_name);
1727 if (prefix != NULL)
1728 pr_len = strlen(prefix);
1729
1730 hdr.code = IMSG_SCRIPT_WRITE_PARAMS;
1731 hdr.len = sizeof(hdr) + sizeof(struct client_lease) +
1732 sizeof(size_t) + fn_len + sizeof(size_t) + sn_len +
1733 sizeof(size_t) + pr_len;
1734
1735 for (i = 0; i < 256; i++)
1736 hdr.len += sizeof(int) + lease->options[i].len;
1737
1738 scripttime = time(NULL);
1739
1740 buf = buf_open(hdr.len);
1741
1742 buf_add(buf, &hdr, sizeof(hdr));
1743 buf_add(buf, lease, sizeof(struct client_lease));
1744 buf_add(buf, &fn_len, sizeof(fn_len));
1745 buf_add(buf, lease->filename, fn_len);
1746 buf_add(buf, &sn_len, sizeof(sn_len));
1747 buf_add(buf, lease->server_name, sn_len);
1748 buf_add(buf, &pr_len, sizeof(pr_len));
1749 buf_add(buf, prefix, pr_len);
1750
1751 for (i = 0; i < 256; i++) {
1752 buf_add(buf, &lease->options[i].len,
1753 sizeof(lease->options[i].len));
1754 buf_add(buf, lease->options[i].data,
1755 lease->options[i].len);
1756 }
1757
1758 buf_close(privfd, buf);
1759}
1760
1761int
1762script_go(void)
1763{
1764 struct imsg_hdr hdr;
1765 struct buf *buf;
1766 int ret;
1767
1768 scripttime = time(NULL);
1769
1770 hdr.code = IMSG_SCRIPT_GO;
1771 hdr.len = sizeof(struct imsg_hdr);
1772
1773 buf = buf_open(hdr.len);
1774
1775 buf_add(buf, &hdr, sizeof(hdr));
1776 buf_close(privfd, buf);
1777
1778 bzero(&hdr, sizeof(hdr));
1779 buf_read(privfd, &hdr, sizeof(hdr));
1780 if (hdr.code != IMSG_SCRIPT_GO_RET)
1781 error("unexpected msg type %u", hdr.code);
1782 if (hdr.len != sizeof(hdr) + sizeof(int))
1783 error("received corrupted message");
1784 buf_read(privfd, &ret, sizeof(ret));
1785
1786 return (ret);
1787}
1788
1789int
1790priv_script_go(void)
1791{
1792 char *scriptName, *argv[2], **envp;
1793 int pid, wpid, wstatus;
1794
1795 scripttime = time(NULL);
1796
1797 scriptName = config->script_name;
1798 envp = client->scriptEnv;
1799
1800 argv[0] = scriptName;
1801 argv[1] = NULL;
1802
1803 pid = fork();
1804 if (pid < 0) {
1805 error("fork: %m");
1806 wstatus = 0;
1807 } else if (pid) {
1808 do {
1809 wpid = wait(&wstatus);
1810 } while (wpid != pid && wpid > 0);
1811 if (wpid < 0) {
1812 error("wait: %m");
1813 wstatus = 0;
1814 }
1815 } else {
1816 execve(scriptName, argv, envp);
1817 error("execve (%s, ...): %m", scriptName);
1818 }
1819
1820 script_flush_env();
1821
1822 return (WEXITSTATUS(wstatus));
1823}
1824
1825void
1826script_set_env(const char *prefix, const char *name, const char *value)
1827{
1828 int i, j, namelen;
1829
1830 namelen = strlen(name);
1831
1832 for (i = 0; client->scriptEnv[i]; i++)
1833 if (strncmp(client->scriptEnv[i], name, namelen) == 0 &&
1834 client->scriptEnv[i][namelen] == '=')
1835 break;
1836
1837 if (client->scriptEnv[i])
1838 /* Reuse the slot. */
1839 free(client->scriptEnv[i]);
1840 else {
1841 /* New variable. Expand if necessary. */
1842 if (i >= client->scriptEnvsize - 1) {
1843 char **newscriptEnv;
1844 int newscriptEnvsize = client->scriptEnvsize + 50;
1845
1846 newscriptEnv = realloc(client->scriptEnv,
1847 newscriptEnvsize);
1848 if (newscriptEnv == NULL) {
1849 free(client->scriptEnv);
1850 client->scriptEnv = NULL;
1851 client->scriptEnvsize = 0;
1852 error("script_set_env: no memory for variable");
1853 }
1854 client->scriptEnv = newscriptEnv;
1855 client->scriptEnvsize = newscriptEnvsize;
1856 }
1857 /* need to set the NULL pointer at end of array beyond
1858 the new slot. */
1859 client->scriptEnv[i + 1] = NULL;
1860 }
1861 /* Allocate space and format the variable in the appropriate slot. */
1862 client->scriptEnv[i] = malloc(strlen(prefix) + strlen(name) + 1 +
1863 strlen(value) + 1);
1864 if (client->scriptEnv[i] == NULL)
1865 error("script_set_env: no memory for variable assignment");
1866
1867 /* No `` or $() command substitution allowed in environment values! */
1868 for (j = 0; j < strlen(value); j++)
1869 switch (value[j]) {
1870 case '`':
1871 case '$':
1872 error("illegal character (%c) in value '%s'", value[j],
1873 value);
1874 /* not reached */
1875 }
1876 snprintf(client->scriptEnv[i], strlen(prefix) + strlen(name) +
1877 1 + strlen(value) + 1, "%s%s=%s", prefix, name, value);
1878}
1879
1880void
1881script_flush_env(void)
1882{
1883 int i;
1884
1885 for (i = 0; client->scriptEnv[i]; i++) {
1886 free(client->scriptEnv[i]);
1887 client->scriptEnv[i] = NULL;
1888 }
1889 client->scriptEnvsize = 0;
1890}
1891
1892int
1893dhcp_option_ev_name(char *buf, size_t buflen, const struct option *option)
1894{
1895 size_t i;
1896
1897 for (i = 0; option->name[i]; i++) {
1898 if (i + 1 == buflen)
1899 return 0;
1900 if (option->name[i] == '-')
1901 buf[i] = '_';
1902 else
1903 buf[i] = option->name[i];
1904 }
1905
1906 buf[i] = 0;
1907 return 1;
1908}
1909
1910void
1911go_daemon(void)
1912{
1913 static int state = 0;
1914
1915 if (no_daemon || state)
1916 return;
1917
1918 state = 1;
1919
1920 /* Stop logging to stderr... */
1921 log_perror = 0;
1922
1923 if (daemon(1, 0) == -1)
1924 error("daemon");
1925
1926 /* we are chrooted, daemon(3) fails to open /dev/null */
1927 if (nullfd != -1) {
1928 dup2(nullfd, STDIN_FILENO);
1929 dup2(nullfd, STDOUT_FILENO);
1930 dup2(nullfd, STDERR_FILENO);
1931 close(nullfd);
1932 nullfd = -1;
1933 }
1934}
1935
1936int
1937check_option(struct client_lease *l, int option)
1938{
1939 char *opbuf;
1940 char *sbuf;
1941
1942 /* we use this, since this is what gets passed to dhclient-script */
1943
1944 opbuf = pretty_print_option(option, l->options[option].data,
1945 l->options[option].len, 0, 0);
1946
1947 sbuf = option_as_string(option, l->options[option].data,
1948 l->options[option].len);
1949
1950 switch (option) {
1951 case DHO_SUBNET_MASK:
1952 case DHO_TIME_SERVERS:
1953 case DHO_NAME_SERVERS:
1954 case DHO_ROUTERS:
1955 case DHO_DOMAIN_NAME_SERVERS:
1956 case DHO_LOG_SERVERS:
1957 case DHO_COOKIE_SERVERS:
1958 case DHO_LPR_SERVERS:
1959 case DHO_IMPRESS_SERVERS:
1960 case DHO_RESOURCE_LOCATION_SERVERS:
1961 case DHO_SWAP_SERVER:
1962 case DHO_BROADCAST_ADDRESS:
1963 case DHO_NIS_SERVERS:
1964 case DHO_NTP_SERVERS:
1965 case DHO_NETBIOS_NAME_SERVERS:
1966 case DHO_NETBIOS_DD_SERVER:
1967 case DHO_FONT_SERVERS:
1968 case DHO_DHCP_SERVER_IDENTIFIER:
1969 if (!ipv4addrs(opbuf)) {
1970 warning("Invalid IP address in option: %s", opbuf);
1971 return (0);
1972 }
1973 return (1);
1974 case DHO_HOST_NAME:
1975 case DHO_DOMAIN_NAME:
1976 case DHO_NIS_DOMAIN:
1977 if (!res_hnok(sbuf)) {
1978 warning("Bogus Host Name option %d: %s (%s)", option,
1979 sbuf, opbuf);
1980 l->options[option].len = 0;
1981 free(l->options[option].data);
1982 }
1983 return (1);
1984 case DHO_PAD:
1985 case DHO_TIME_OFFSET:
1986 case DHO_BOOT_SIZE:
1987 case DHO_MERIT_DUMP:
1988 case DHO_ROOT_PATH:
1989 case DHO_EXTENSIONS_PATH:
1990 case DHO_IP_FORWARDING:
1991 case DHO_NON_LOCAL_SOURCE_ROUTING:
1992 case DHO_POLICY_FILTER:
1993 case DHO_MAX_DGRAM_REASSEMBLY:
1994 case DHO_DEFAULT_IP_TTL:
1995 case DHO_PATH_MTU_AGING_TIMEOUT:
1996 case DHO_PATH_MTU_PLATEAU_TABLE:
1997 case DHO_INTERFACE_MTU:
1998 case DHO_ALL_SUBNETS_LOCAL:
1999 case DHO_PERFORM_MASK_DISCOVERY:
2000 case DHO_MASK_SUPPLIER:
2001 case DHO_ROUTER_DISCOVERY:
2002 case DHO_ROUTER_SOLICITATION_ADDRESS:
2003 case DHO_STATIC_ROUTES:
2004 case DHO_TRAILER_ENCAPSULATION:
2005 case DHO_ARP_CACHE_TIMEOUT:
2006 case DHO_IEEE802_3_ENCAPSULATION:
2007 case DHO_DEFAULT_TCP_TTL:
2008 case DHO_TCP_KEEPALIVE_INTERVAL:
2009 case DHO_TCP_KEEPALIVE_GARBAGE:
2010 case DHO_VENDOR_ENCAPSULATED_OPTIONS:
2011 case DHO_NETBIOS_NODE_TYPE:
2012 case DHO_NETBIOS_SCOPE:
2013 case DHO_X_DISPLAY_MANAGER:
2014 case DHO_DHCP_REQUESTED_ADDRESS:
2015 case DHO_DHCP_LEASE_TIME:
2016 case DHO_DHCP_OPTION_OVERLOAD:
2017 case DHO_DHCP_MESSAGE_TYPE:
2018 case DHO_DHCP_PARAMETER_REQUEST_LIST:
2019 case DHO_DHCP_MESSAGE:
2020 case DHO_DHCP_MAX_MESSAGE_SIZE:
2021 case DHO_DHCP_RENEWAL_TIME:
2022 case DHO_DHCP_REBINDING_TIME:
2023 case DHO_DHCP_CLASS_IDENTIFIER:
2024 case DHO_DHCP_CLIENT_IDENTIFIER:
2025 case DHO_DHCP_USER_CLASS_ID:
2026 case DHO_END:
2027 return (1);
2028 default:
2029 warning("unknown dhcp option value 0x%x", option);
2030 return (unknown_ok);
2031 }
2032}
2033
2034int
2035res_hnok(const char *name)
2036{
2037 const char *dn = name;
2038 int pch = '.', ch = *dn++;
2039 int warn = 0;
2040
2041 while (ch != '\0') {
2042 int nch = *dn++;
2043
2044 if (ch == '.') {
2045 ;
2046 } else if (pch == '.' || nch == '.' || nch == '\0') {
2047 if (!isalnum(ch))
2048 return (0);
2049 } else if (!isalnum(ch) && ch != '-' && ch != '_')
2050 return (0);
2051 else if (ch == '_' && warn == 0) {
2052 warning("warning: hostname %s contains an "
2053 "underscore which violates RFC 952", name);
2054 warn++;
2055 }
2056 pch = ch, ch = nch;
2057 }
2058 return (1);
2059}
2060
2061/* Does buf consist only of dotted decimal ipv4 addrs?
2062 * return how many if so,
2063 * otherwise, return 0
2064 */
2065int
2066ipv4addrs(char * buf)
2067{
2068 struct in_addr jnk;
2069 int count = 0;
2070
2071 while (inet_aton(buf, &jnk) == 1){
2072 count++;
2073 while (*buf == '.' || isdigit(*buf))
2074 buf++;
2075 if (*buf == '\0')
2076 return (count);
2077 while (*buf == ' ')
2078 buf++;
2079 }
2080 return (0);
2081}
2082
2083char *
2084option_as_string(unsigned int code, unsigned char *data, int len)
2085{
2086 static char optbuf[32768]; /* XXX */
2087 char *op = optbuf;
2088 int opleft = sizeof(optbuf);
2089 unsigned char *dp = data;
2090
2091 if (code > 255)
2092 error("option_as_string: bad code %d", code);
2093
2094 for (; dp < data + len; dp++) {
2095 if (!isascii(*dp) || !isprint(*dp)) {
2096 if (dp + 1 != data + len || *dp != 0) {
2097 size_t oplen;
2098 snprintf(op, opleft, "\\%03o", *dp);
2099 oplen = strlen(op);
2100 op += oplen;
2101 opleft -= oplen;
2102 }
2103 } else if (*dp == '"' || *dp == '\'' || *dp == '$' ||
2104 *dp == '`' || *dp == '\\') {
2105 *op++ = '\\';
2106 *op++ = *dp;
2107 opleft -= 2;
2108 } else {
2109 *op++ = *dp;
2110 opleft--;
2111 }
2112 }
2113 if (opleft < 1)
2114 goto toobig;
2115 *op = 0;
2116 return optbuf;
2117toobig:
2118 warning("dhcp option too large");
2119 return "<error>";
2120}
2121
2122int
2123fork_privchld(int fd, int fd2)
2124{
2125 struct pollfd pfd[1];
a05d48e6 2126 int nfds, pfail = 0;
846204b6
HT
2127
2128 switch (fork()) {
2129 case -1:
2130 error("cannot fork");
2131 break;
2132 case 0:
2133 break;
2134 default:
2135 return (0);
2136 }
2137
2138 if (chdir("/") == -1)
2139 error("chdir(\"/\")");
2140
2141 setproctitle("%s [priv]", ifi->name);
2142
2143 dup2(nullfd, STDIN_FILENO);
2144 dup2(nullfd, STDOUT_FILENO);
2145 dup2(nullfd, STDERR_FILENO);
2146 close(nullfd);
2147 close(fd2);
2148
2149 for (;;) {
2150 pfd[0].fd = fd;
2151 pfd[0].events = POLLIN;
2152 if ((nfds = poll(pfd, 1, INFTIM)) == -1)
2153 if (errno != EINTR)
2154 error("poll error");
2155
a05d48e6
SG
2156 /*
2157 * Handle temporary errors, but bail if they persist.
2158 */
2159 if (nfds == 0 || !(pfd[0].revents & POLLIN)) {
2160 if (pfail > POLL_FAILURES)
2161 error("poll failed > %d times", POLL_FAILURES);
2162 sleep(pfail * POLL_FAILURE_WAIT);
2163 pfail++;
846204b6 2164 continue;
a05d48e6 2165 }
846204b6
HT
2166
2167 dispatch_imsg(fd);
2168 }
2169}