1 /* $OpenBSD: dhclient.c,v 1.63 2005/02/06 17:10:13 krw Exp $ */
2
3 /*
4 * Copyright 2004 Henning Brauer <henning@openbsd.org>
5 * Copyright (c) 1995, 1996, 1997, 1998, 1999
6 * The Internet Software Consortium. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of The Internet Software Consortium nor the names
18 * of its contributors may be used to endorse or promote products derived
19 * from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
22 * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
23 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
25 * DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
26 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
27 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
28 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
29 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
30 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
31 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
32 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * This software has been written for the Internet Software Consortium
36 * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
37 * Enterprises. To learn more about the Internet Software Consortium,
38 * see ``http://www.vix.com/isc''. To learn more about Vixie
39 * Enterprises, see ``http://www.vix.com''.
40 *
41 * This client was substantially modified and enhanced by Elliot Poger
42 * for use on Linux while he was working on the MosquitoNet project at
43 * Stanford.
44 *
45 * The current version owes much to Elliot's Linux enhancements, but
46 * was substantially reorganized and partially rewritten by Ted Lemon
47 * so as to use the same networking framework that the Internet Software
48 * Consortium DHCP server uses. Much system-specific configuration code
49 * was moved into a shell script so that as support for more operating
50 * systems is added, it will not be necessary to port and maintain
51 * system-specific configuration code to these operating systems - instead,
52 * the shell script can invoke the native tools to accomplish the same
53 * purpose.
54 */
55
56 #include <sys/cdefs.h>
57 __FBSDID("$FreeBSD$");
58
59 #include <sys/capsicum.h>
60
61 #include "dhcpd.h"
62 #include "privsep.h"
63
64 #include <sys/capsicum.h>
65
66 #include <net80211/ieee80211_freebsd.h>
67
68 #ifndef _PATH_VAREMPTY
69 #define _PATH_VAREMPTY "/var/empty"
70 #endif
71
72 #define PERIOD 0x2e
73 #define hyphenchar(c) ((c) == 0x2d)
74 #define bslashchar(c) ((c) == 0x5c)
75 #define periodchar(c) ((c) == PERIOD)
76 #define asterchar(c) ((c) == 0x2a)
77 #define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) || \
78 ((c) >= 0x61 && (c) <= 0x7a))
79 #define digitchar(c) ((c) >= 0x30 && (c) <= 0x39)
80 #define whitechar(c) ((c) == ' ' || (c) == '\t')
81
82 #define borderchar(c) (alphachar(c) || digitchar(c))
83 #define middlechar(c) (borderchar(c) || hyphenchar(c))
84 #define domainchar(c) ((c) > 0x20 && (c) < 0x7f)
85
86 #define CLIENT_PATH "PATH=/usr/bin:/usr/sbin:/bin:/sbin"
87
88 time_t cur_time;
89 time_t default_lease_time = 43200; /* 12 hours... */
90
91 char *path_dhclient_conf = _PATH_DHCLIENT_CONF;
92 char *path_dhclient_db = NULL;
93
94 int log_perror = 1;
95 int privfd;
96 int nullfd = -1;
97
98 char hostname[_POSIX_HOST_NAME_MAX + 1];
99
100 struct iaddr iaddr_broadcast = { 4, { 255, 255, 255, 255 } };
101 struct in_addr inaddr_any, inaddr_broadcast;
102
103 char *path_dhclient_pidfile;
104 struct pidfh *pidfile;
105
106 /*
107 * ASSERT_STATE() does nothing now; it used to be
108 * assert (state_is == state_shouldbe).
109 */
110 #define ASSERT_STATE(state_is, state_shouldbe) {}
111
112 #define TIME_MAX 2147483647
113
114 int log_priority;
115 int no_daemon;
116 int unknown_ok = 1;
117 int routefd;
118
119 struct interface_info *ifi;
120
121 int findproto(char *, int);
122 struct sockaddr *get_ifa(char *, int);
123 void routehandler(struct protocol *);
124 void usage(void);
125 int check_option(struct client_lease *l, int option);
126 int check_classless_option(unsigned char *data, int len);
127 int ipv4addrs(char * buf);
128 int res_hnok(const char *dn);
129 int check_search(const char *srch);
130 char *option_as_string(unsigned int code, unsigned char *data, int len);
131 int fork_privchld(int, int);
132
133 #define ROUNDUP(a) \
134 ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
135 #define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))
136
137 static time_t scripttime;
138
139 int
findproto(char * cp,int n)140 findproto(char *cp, int n)
141 {
142 struct sockaddr *sa;
143 int i;
144
145 if (n == 0)
146 return -1;
147 for (i = 1; i; i <<= 1) {
148 if (i & n) {
149 sa = (struct sockaddr *)cp;
150 switch (i) {
151 case RTA_IFA:
152 case RTA_DST:
153 case RTA_GATEWAY:
154 case RTA_NETMASK:
155 if (sa->sa_family == AF_INET)
156 return AF_INET;
157 if (sa->sa_family == AF_INET6)
158 return AF_INET6;
159 break;
160 case RTA_IFP:
161 break;
162 }
163 ADVANCE(cp, sa);
164 }
165 }
166 return (-1);
167 }
168
169 struct sockaddr *
get_ifa(char * cp,int n)170 get_ifa(char *cp, int n)
171 {
172 struct sockaddr *sa;
173 int i;
174
175 if (n == 0)
176 return (NULL);
177 for (i = 1; i; i <<= 1)
178 if (i & n) {
179 sa = (struct sockaddr *)cp;
180 if (i == RTA_IFA)
181 return (sa);
182 ADVANCE(cp, sa);
183 }
184
185 return (NULL);
186 }
187
188 struct iaddr defaddr = { 4 };
189 uint8_t curbssid[6];
190
191 static void
disassoc(void * arg)192 disassoc(void *arg)
193 {
194 struct interface_info *ifi = arg;
195
196 /*
197 * Clear existing state.
198 */
199 if (ifi->client->active != NULL) {
200 script_init("EXPIRE", NULL);
201 script_write_params("old_",
202 ifi->client->active);
203 if (ifi->client->alias)
204 script_write_params("alias_",
205 ifi->client->alias);
206 script_go();
207 }
208 ifi->client->state = S_INIT;
209 }
210
211 /* ARGSUSED */
212 void
routehandler(struct protocol * p)213 routehandler(struct protocol *p)
214 {
215 char msg[2048], *addr;
216 struct rt_msghdr *rtm;
217 struct if_msghdr *ifm;
218 struct ifa_msghdr *ifam;
219 struct if_announcemsghdr *ifan;
220 struct ieee80211_join_event *jev;
221 struct client_lease *l;
222 time_t t = time(NULL);
223 struct sockaddr *sa;
224 struct iaddr a;
225 ssize_t n;
226 int linkstat;
227
228 n = read(routefd, &msg, sizeof(msg));
229 rtm = (struct rt_msghdr *)msg;
230 if (n < sizeof(rtm->rtm_msglen) || n < rtm->rtm_msglen ||
231 rtm->rtm_version != RTM_VERSION)
232 return;
233
234 switch (rtm->rtm_type) {
235 case RTM_NEWADDR:
236 case RTM_DELADDR:
237 ifam = (struct ifa_msghdr *)rtm;
238
239 if (ifam->ifam_index != ifi->index)
240 break;
241 if (findproto((char *)(ifam + 1), ifam->ifam_addrs) != AF_INET)
242 break;
243 if (scripttime == 0 || t < scripttime + 10)
244 break;
245
246 sa = get_ifa((char *)(ifam + 1), ifam->ifam_addrs);
247 if (sa == NULL)
248 break;
249
250 if ((a.len = sizeof(struct in_addr)) > sizeof(a.iabuf))
251 error("king bula sez: len mismatch");
252 memcpy(a.iabuf, &((struct sockaddr_in *)sa)->sin_addr, a.len);
253 if (addr_eq(a, defaddr))
254 break;
255
256 for (l = ifi->client->active; l != NULL; l = l->next)
257 if (addr_eq(a, l->address))
258 break;
259
260 if (l == NULL) /* added/deleted addr is not the one we set */
261 break;
262
263 addr = inet_ntoa(((struct sockaddr_in *)sa)->sin_addr);
264 if (rtm->rtm_type == RTM_NEWADDR) {
265 /*
266 * XXX: If someone other than us adds our address,
267 * should we assume they are taking over from us,
268 * delete the lease record, and exit without modifying
269 * the interface?
270 */
271 warning("My address (%s) was re-added", addr);
272 } else {
273 warning("My address (%s) was deleted, dhclient exiting",
274 addr);
275 goto die;
276 }
277 break;
278 case RTM_IFINFO:
279 ifm = (struct if_msghdr *)rtm;
280 if (ifm->ifm_index != ifi->index)
281 break;
282 if ((rtm->rtm_flags & RTF_UP) == 0) {
283 warning("Interface %s is down, dhclient exiting",
284 ifi->name);
285 goto die;
286 }
287 linkstat = interface_link_status(ifi->name);
288 if (linkstat != ifi->linkstat) {
289 debug("%s link state %s -> %s", ifi->name,
290 ifi->linkstat ? "up" : "down",
291 linkstat ? "up" : "down");
292 ifi->linkstat = linkstat;
293 if (linkstat)
294 state_reboot(ifi);
295 }
296 break;
297 case RTM_IFANNOUNCE:
298 ifan = (struct if_announcemsghdr *)rtm;
299 if (ifan->ifan_what == IFAN_DEPARTURE &&
300 ifan->ifan_index == ifi->index) {
301 warning("Interface %s is gone, dhclient exiting",
302 ifi->name);
303 goto die;
304 }
305 break;
306 case RTM_IEEE80211:
307 ifan = (struct if_announcemsghdr *)rtm;
308 if (ifan->ifan_index != ifi->index)
309 break;
310 switch (ifan->ifan_what) {
311 case RTM_IEEE80211_ASSOC:
312 case RTM_IEEE80211_REASSOC:
313 /*
314 * Use assoc/reassoc event to kick state machine
315 * in case we roam. Otherwise fall back to the
316 * normal state machine just like a wired network.
317 */
318 jev = (struct ieee80211_join_event *) &ifan[1];
319 if (memcmp(curbssid, jev->iev_addr, 6)) {
320 disassoc(ifi);
321 state_reboot(ifi);
322 }
323 memcpy(curbssid, jev->iev_addr, 6);
324 break;
325 }
326 break;
327 default:
328 break;
329 }
330 return;
331
332 die:
333 script_init("FAIL", NULL);
334 if (ifi->client->alias)
335 script_write_params("alias_", ifi->client->alias);
336 script_go();
337 if (pidfile != NULL)
338 pidfile_remove(pidfile);
339 exit(1);
340 }
341
342 int
main(int argc,char * argv[])343 main(int argc, char *argv[])
344 {
345 extern char *__progname;
346 int ch, fd, quiet = 0, i = 0;
347 int pipe_fd[2];
348 int immediate_daemon = 0;
349 struct passwd *pw;
350 pid_t otherpid;
351 cap_rights_t rights;
352
353 /* Initially, log errors to stderr as well as to syslogd. */
354 openlog(__progname, LOG_PID | LOG_NDELAY, DHCPD_LOG_FACILITY);
355 setlogmask(LOG_UPTO(LOG_DEBUG));
356
357 while ((ch = getopt(argc, argv, "bc:dl:p:qu")) != -1)
358 switch (ch) {
359 case 'b':
360 immediate_daemon = 1;
361 break;
362 case 'c':
363 path_dhclient_conf = optarg;
364 break;
365 case 'd':
366 no_daemon = 1;
367 break;
368 case 'l':
369 path_dhclient_db = optarg;
370 break;
371 case 'p':
372 path_dhclient_pidfile = optarg;
373 break;
374 case 'q':
375 quiet = 1;
376 break;
377 case 'u':
378 unknown_ok = 0;
379 break;
380 default:
381 usage();
382 }
383
384 argc -= optind;
385 argv += optind;
386
387 if (argc != 1)
388 usage();
389
390 if (path_dhclient_pidfile == NULL) {
391 asprintf(&path_dhclient_pidfile,
392 "%sdhclient.%s.pid", _PATH_VARRUN, *argv);
393 if (path_dhclient_pidfile == NULL)
394 error("asprintf");
395 }
396 pidfile = pidfile_open(path_dhclient_pidfile, 0600, &otherpid);
397 if (pidfile == NULL) {
398 if (errno == EEXIST)
399 error("dhclient already running, pid: %d.", otherpid);
400 if (errno == EAGAIN)
401 error("dhclient already running.");
402 warning("Cannot open or create pidfile: %m");
403 }
404
405 if ((ifi = calloc(1, sizeof(struct interface_info))) == NULL)
406 error("calloc");
407 if (strlcpy(ifi->name, argv[0], IFNAMSIZ) >= IFNAMSIZ)
408 error("Interface name too long");
409 if (path_dhclient_db == NULL && asprintf(&path_dhclient_db, "%s.%s",
410 _PATH_DHCLIENT_DB, ifi->name) == -1)
411 error("asprintf");
412
413 if (quiet)
414 log_perror = 0;
415
416 tzset();
417 time(&cur_time);
418
419 inaddr_broadcast.s_addr = INADDR_BROADCAST;
420 inaddr_any.s_addr = INADDR_ANY;
421
422 read_client_conf();
423
424 /* The next bit is potentially very time-consuming, so write out
425 the pidfile right away. We will write it out again with the
426 correct pid after daemonizing. */
427 if (pidfile != NULL)
428 pidfile_write(pidfile);
429
430 if (!interface_link_status(ifi->name)) {
431 fprintf(stderr, "%s: no link ...", ifi->name);
432 fflush(stderr);
433 sleep(1);
434 while (!interface_link_status(ifi->name)) {
435 fprintf(stderr, ".");
436 fflush(stderr);
437 if (++i > 10) {
438 fprintf(stderr, " giving up\n");
439 exit(1);
440 }
441 sleep(1);
442 }
443 fprintf(stderr, " got link\n");
444 }
445 ifi->linkstat = 1;
446
447 if ((nullfd = open(_PATH_DEVNULL, O_RDWR, 0)) == -1)
448 error("cannot open %s: %m", _PATH_DEVNULL);
449
450 if ((pw = getpwnam("_dhcp")) == NULL) {
451 warning("no such user: _dhcp, falling back to \"nobody\"");
452 if ((pw = getpwnam("nobody")) == NULL)
453 error("no such user: nobody");
454 }
455
456 /*
457 * Obtain hostname before entering capability mode - it won't be
458 * possible then, as reading kern.hostname is not permitted.
459 */
460 if (gethostname(hostname, sizeof(hostname)) < 0)
461 hostname[0] = '\0';
462
463 priv_script_init("PREINIT", NULL);
464 if (ifi->client->alias)
465 priv_script_write_params("alias_", ifi->client->alias);
466 priv_script_go();
467
468 /* set up the interface */
469 discover_interfaces(ifi);
470
471 if (pipe(pipe_fd) == -1)
472 error("pipe");
473
474 fork_privchld(pipe_fd[0], pipe_fd[1]);
475
476 close(ifi->ufdesc);
477 ifi->ufdesc = -1;
478 close(ifi->wfdesc);
479 ifi->wfdesc = -1;
480
481 close(pipe_fd[0]);
482 privfd = pipe_fd[1];
483 cap_rights_init(&rights, CAP_READ, CAP_WRITE);
484 if (cap_rights_limit(privfd, &rights) < 0 && errno != ENOSYS)
485 error("can't limit private descriptor: %m");
486
487 if ((fd = open(path_dhclient_db, O_RDONLY|O_EXLOCK|O_CREAT, 0)) == -1)
488 error("can't open and lock %s: %m", path_dhclient_db);
489 read_client_leases();
490 rewrite_client_leases();
491 close(fd);
492
493 if ((routefd = socket(PF_ROUTE, SOCK_RAW, 0)) != -1)
494 add_protocol("AF_ROUTE", routefd, routehandler, ifi);
495 if (shutdown(routefd, SHUT_WR) < 0)
496 error("can't shutdown route socket: %m");
497 cap_rights_init(&rights, CAP_EVENT, CAP_READ);
498 if (cap_rights_limit(routefd, &rights) < 0 && errno != ENOSYS)
499 error("can't limit route socket: %m");
500
501 if (chroot(_PATH_VAREMPTY) == -1)
502 error("chroot");
503 if (chdir("/") == -1)
504 error("chdir(\"/\")");
505
506 if (setgroups(1, &pw->pw_gid) ||
507 setegid(pw->pw_gid) || setgid(pw->pw_gid) ||
508 seteuid(pw->pw_uid) || setuid(pw->pw_uid))
509 error("can't drop privileges: %m");
510
511 endpwent();
512
513 setproctitle("%s", ifi->name);
514
515 if (cap_enter() < 0 && errno != ENOSYS)
516 error("can't enter capability mode: %m");
517
518 if (immediate_daemon)
519 go_daemon();
520
521 ifi->client->state = S_INIT;
522 state_reboot(ifi);
523
524 bootp_packet_handler = do_packet;
525
526 dispatch();
527
528 /* not reached */
529 return (0);
530 }
531
532 void
usage(void)533 usage(void)
534 {
535 extern char *__progname;
536
537 fprintf(stderr, "usage: %s [-bdqu] ", __progname);
538 fprintf(stderr, "[-c conffile] [-l leasefile] interface\n");
539 exit(1);
540 }
541
542 /*
543 * Individual States:
544 *
545 * Each routine is called from the dhclient_state_machine() in one of
546 * these conditions:
547 * -> entering INIT state
548 * -> recvpacket_flag == 0: timeout in this state
549 * -> otherwise: received a packet in this state
550 *
551 * Return conditions as handled by dhclient_state_machine():
552 * Returns 1, sendpacket_flag = 1: send packet, reset timer.
553 * Returns 1, sendpacket_flag = 0: just reset the timer (wait for a milestone).
554 * Returns 0: finish the nap which was interrupted for no good reason.
555 *
556 * Several per-interface variables are used to keep track of the process:
557 * active_lease: the lease that is being used on the interface
558 * (null pointer if not configured yet).
559 * offered_leases: leases corresponding to DHCPOFFER messages that have
560 * been sent to us by DHCP servers.
561 * acked_leases: leases corresponding to DHCPACK messages that have been
562 * sent to us by DHCP servers.
563 * sendpacket: DHCP packet we're trying to send.
564 * destination: IP address to send sendpacket to
565 * In addition, there are several relevant per-lease variables.
566 * T1_expiry, T2_expiry, lease_expiry: lease milestones
567 * In the active lease, these control the process of renewing the lease;
568 * In leases on the acked_leases list, this simply determines when we
569 * can no longer legitimately use the lease.
570 */
571
572 void
state_reboot(void * ipp)573 state_reboot(void *ipp)
574 {
575 struct interface_info *ip = ipp;
576
577 /* If we don't remember an active lease, go straight to INIT. */
578 if (!ip->client->active || ip->client->active->is_bootp) {
579 state_init(ip);
580 return;
581 }
582
583 /* We are in the rebooting state. */
584 ip->client->state = S_REBOOTING;
585
586 /* make_request doesn't initialize xid because it normally comes
587 from the DHCPDISCOVER, but we haven't sent a DHCPDISCOVER,
588 so pick an xid now. */
589 ip->client->xid = arc4random();
590
591 /* Make a DHCPREQUEST packet, and set appropriate per-interface
592 flags. */
593 make_request(ip, ip->client->active);
594 ip->client->destination = iaddr_broadcast;
595 ip->client->first_sending = cur_time;
596 ip->client->interval = ip->client->config->initial_interval;
597
598 /* Zap the medium list... */
599 ip->client->medium = NULL;
600
601 /* Send out the first DHCPREQUEST packet. */
602 send_request(ip);
603 }
604
605 /*
606 * Called when a lease has completely expired and we've
607 * been unable to renew it.
608 */
609 void
state_init(void * ipp)610 state_init(void *ipp)
611 {
612 struct interface_info *ip = ipp;
613
614 ASSERT_STATE(state, S_INIT);
615
616 /* Make a DHCPDISCOVER packet, and set appropriate per-interface
617 flags. */
618 make_discover(ip, ip->client->active);
619 ip->client->xid = ip->client->packet.xid;
620 ip->client->destination = iaddr_broadcast;
621 ip->client->state = S_SELECTING;
622 ip->client->first_sending = cur_time;
623 ip->client->interval = ip->client->config->initial_interval;
624
625 /* Add an immediate timeout to cause the first DHCPDISCOVER packet
626 to go out. */
627 send_discover(ip);
628 }
629
630 /*
631 * state_selecting is called when one or more DHCPOFFER packets
632 * have been received and a configurable period of time has passed.
633 */
634 void
state_selecting(void * ipp)635 state_selecting(void *ipp)
636 {
637 struct interface_info *ip = ipp;
638 struct client_lease *lp, *next, *picked;
639
640 ASSERT_STATE(state, S_SELECTING);
641
642 /* Cancel state_selecting and send_discover timeouts, since either
643 one could have got us here. */
644 cancel_timeout(state_selecting, ip);
645 cancel_timeout(send_discover, ip);
646
647 /* We have received one or more DHCPOFFER packets. Currently,
648 the only criterion by which we judge leases is whether or
649 not we get a response when we arp for them. */
650 picked = NULL;
651 for (lp = ip->client->offered_leases; lp; lp = next) {
652 next = lp->next;
653
654 /* Check to see if we got an ARPREPLY for the address
655 in this particular lease. */
656 if (!picked) {
657 script_init("ARPCHECK", lp->medium);
658 script_write_params("check_", lp);
659
660 /* If the ARPCHECK code detects another
661 machine using the offered address, it exits
662 nonzero. We need to send a DHCPDECLINE and
663 toss the lease. */
664 if (script_go()) {
665 make_decline(ip, lp);
666 send_decline(ip);
667 goto freeit;
668 }
669 picked = lp;
670 picked->next = NULL;
671 } else {
672 freeit:
673 free_client_lease(lp);
674 }
675 }
676 ip->client->offered_leases = NULL;
677
678 /* If we just tossed all the leases we were offered, go back
679 to square one. */
680 if (!picked) {
681 ip->client->state = S_INIT;
682 state_init(ip);
683 return;
684 }
685
686 /* If it was a BOOTREPLY, we can just take the address right now. */
687 if (!picked->options[DHO_DHCP_MESSAGE_TYPE].len) {
688 ip->client->new = picked;
689
690 /* Make up some lease expiry times
691 XXX these should be configurable. */
692 ip->client->new->expiry = cur_time + 12000;
693 ip->client->new->renewal += cur_time + 8000;
694 ip->client->new->rebind += cur_time + 10000;
695
696 ip->client->state = S_REQUESTING;
697
698 /* Bind to the address we received. */
699 bind_lease(ip);
700 return;
701 }
702
703 /* Go to the REQUESTING state. */
704 ip->client->destination = iaddr_broadcast;
705 ip->client->state = S_REQUESTING;
706 ip->client->first_sending = cur_time;
707 ip->client->interval = ip->client->config->initial_interval;
708
709 /* Make a DHCPREQUEST packet from the lease we picked. */
710 make_request(ip, picked);
711 ip->client->xid = ip->client->packet.xid;
712
713 /* Toss the lease we picked - we'll get it back in a DHCPACK. */
714 free_client_lease(picked);
715
716 /* Add an immediate timeout to send the first DHCPREQUEST packet. */
717 send_request(ip);
718 }
719
720 /* state_requesting is called when we receive a DHCPACK message after
721 having sent out one or more DHCPREQUEST packets. */
722
723 void
dhcpack(struct packet * packet)724 dhcpack(struct packet *packet)
725 {
726 struct interface_info *ip = packet->interface;
727 struct client_lease *lease;
728
729 /* If we're not receptive to an offer right now, or if the offer
730 has an unrecognizable transaction id, then just drop it. */
731 if (packet->interface->client->xid != packet->raw->xid ||
732 (packet->interface->hw_address.hlen != packet->raw->hlen) ||
733 (memcmp(packet->interface->hw_address.haddr,
734 packet->raw->chaddr, packet->raw->hlen)))
735 return;
736
737 if (ip->client->state != S_REBOOTING &&
738 ip->client->state != S_REQUESTING &&
739 ip->client->state != S_RENEWING &&
740 ip->client->state != S_REBINDING)
741 return;
742
743 note("DHCPACK from %s", piaddr(packet->client_addr));
744
745 lease = packet_to_lease(packet);
746 if (!lease) {
747 note("packet_to_lease failed.");
748 return;
749 }
750
751 ip->client->new = lease;
752
753 /* Stop resending DHCPREQUEST. */
754 cancel_timeout(send_request, ip);
755
756 /* Figure out the lease time. */
757 if (ip->client->new->options[DHO_DHCP_LEASE_TIME].data)
758 ip->client->new->expiry = getULong(
759 ip->client->new->options[DHO_DHCP_LEASE_TIME].data);
760 else
761 ip->client->new->expiry = default_lease_time;
762 /* A number that looks negative here is really just very large,
763 because the lease expiry offset is unsigned. */
764 if (ip->client->new->expiry < 0)
765 ip->client->new->expiry = TIME_MAX;
766 /* XXX should be fixed by resetting the client state */
767 if (ip->client->new->expiry < 60)
768 ip->client->new->expiry = 60;
769
770 /* Take the server-provided renewal time if there is one;
771 otherwise figure it out according to the spec. */
772 if (ip->client->new->options[DHO_DHCP_RENEWAL_TIME].len)
773 ip->client->new->renewal = getULong(
774 ip->client->new->options[DHO_DHCP_RENEWAL_TIME].data);
775 else
776 ip->client->new->renewal = ip->client->new->expiry / 2;
777
778 /* Same deal with the rebind time. */
779 if (ip->client->new->options[DHO_DHCP_REBINDING_TIME].len)
780 ip->client->new->rebind = getULong(
781 ip->client->new->options[DHO_DHCP_REBINDING_TIME].data);
782 else
783 ip->client->new->rebind = ip->client->new->renewal +
784 ip->client->new->renewal / 2 + ip->client->new->renewal / 4;
785
786 ip->client->new->expiry += cur_time;
787 /* Lease lengths can never be negative. */
788 if (ip->client->new->expiry < cur_time)
789 ip->client->new->expiry = TIME_MAX;
790 ip->client->new->renewal += cur_time;
791 if (ip->client->new->renewal < cur_time)
792 ip->client->new->renewal = TIME_MAX;
793 ip->client->new->rebind += cur_time;
794 if (ip->client->new->rebind < cur_time)
795 ip->client->new->rebind = TIME_MAX;
796
797 bind_lease(ip);
798 }
799
800 void
bind_lease(struct interface_info * ip)801 bind_lease(struct interface_info *ip)
802 {
803 /* Remember the medium. */
804 ip->client->new->medium = ip->client->medium;
805
806 /* Write out the new lease. */
807 write_client_lease(ip, ip->client->new, 0);
808
809 /* Run the client script with the new parameters. */
810 script_init((ip->client->state == S_REQUESTING ? "BOUND" :
811 (ip->client->state == S_RENEWING ? "RENEW" :
812 (ip->client->state == S_REBOOTING ? "REBOOT" : "REBIND"))),
813 ip->client->new->medium);
814 if (ip->client->active && ip->client->state != S_REBOOTING)
815 script_write_params("old_", ip->client->active);
816 script_write_params("new_", ip->client->new);
817 if (ip->client->alias)
818 script_write_params("alias_", ip->client->alias);
819 script_go();
820
821 /* Replace the old active lease with the new one. */
822 if (ip->client->active)
823 free_client_lease(ip->client->active);
824 ip->client->active = ip->client->new;
825 ip->client->new = NULL;
826
827 /* Set up a timeout to start the renewal process. */
828 add_timeout(ip->client->active->renewal, state_bound, ip);
829
830 note("bound to %s -- renewal in %d seconds.",
831 piaddr(ip->client->active->address),
832 (int)(ip->client->active->renewal - cur_time));
833 ip->client->state = S_BOUND;
834 reinitialize_interfaces();
835 go_daemon();
836 }
837
838 /*
839 * state_bound is called when we've successfully bound to a particular
840 * lease, but the renewal time on that lease has expired. We are
841 * expected to unicast a DHCPREQUEST to the server that gave us our
842 * original lease.
843 */
844 void
state_bound(void * ipp)845 state_bound(void *ipp)
846 {
847 struct interface_info *ip = ipp;
848
849 ASSERT_STATE(state, S_BOUND);
850
851 /* T1 has expired. */
852 make_request(ip, ip->client->active);
853 ip->client->xid = ip->client->packet.xid;
854
855 if (ip->client->active->options[DHO_DHCP_SERVER_IDENTIFIER].len == 4) {
856 memcpy(ip->client->destination.iabuf, ip->client->active->
857 options[DHO_DHCP_SERVER_IDENTIFIER].data, 4);
858 ip->client->destination.len = 4;
859 } else
860 ip->client->destination = iaddr_broadcast;
861
862 ip->client->first_sending = cur_time;
863 ip->client->interval = ip->client->config->initial_interval;
864 ip->client->state = S_RENEWING;
865
866 /* Send the first packet immediately. */
867 send_request(ip);
868 }
869
870 void
bootp(struct packet * packet)871 bootp(struct packet *packet)
872 {
873 struct iaddrlist *ap;
874
875 if (packet->raw->op != BOOTREPLY)
876 return;
877
878 /* If there's a reject list, make sure this packet's sender isn't
879 on it. */
880 for (ap = packet->interface->client->config->reject_list;
881 ap; ap = ap->next) {
882 if (addr_eq(packet->client_addr, ap->addr)) {
883 note("BOOTREPLY from %s rejected.", piaddr(ap->addr));
884 return;
885 }
886 }
887 dhcpoffer(packet);
888 }
889
890 void
dhcp(struct packet * packet)891 dhcp(struct packet *packet)
892 {
893 struct iaddrlist *ap;
894 void (*handler)(struct packet *);
895 char *type;
896
897 switch (packet->packet_type) {
898 case DHCPOFFER:
899 handler = dhcpoffer;
900 type = "DHCPOFFER";
901 break;
902 case DHCPNAK:
903 handler = dhcpnak;
904 type = "DHCPNACK";
905 break;
906 case DHCPACK:
907 handler = dhcpack;
908 type = "DHCPACK";
909 break;
910 default:
911 return;
912 }
913
914 /* If there's a reject list, make sure this packet's sender isn't
915 on it. */
916 for (ap = packet->interface->client->config->reject_list;
917 ap; ap = ap->next) {
918 if (addr_eq(packet->client_addr, ap->addr)) {
919 note("%s from %s rejected.", type, piaddr(ap->addr));
920 return;
921 }
922 }
923 (*handler)(packet);
924 }
925
926 void
dhcpoffer(struct packet * packet)927 dhcpoffer(struct packet *packet)
928 {
929 struct interface_info *ip = packet->interface;
930 struct client_lease *lease, *lp;
931 int i;
932 int arp_timeout_needed, stop_selecting;
933 char *name = packet->options[DHO_DHCP_MESSAGE_TYPE].len ?
934 "DHCPOFFER" : "BOOTREPLY";
935
936 /* If we're not receptive to an offer right now, or if the offer
937 has an unrecognizable transaction id, then just drop it. */
938 if (ip->client->state != S_SELECTING ||
939 packet->interface->client->xid != packet->raw->xid ||
940 (packet->interface->hw_address.hlen != packet->raw->hlen) ||
941 (memcmp(packet->interface->hw_address.haddr,
942 packet->raw->chaddr, packet->raw->hlen)))
943 return;
944
945 note("%s from %s", name, piaddr(packet->client_addr));
946
947
948 /* If this lease doesn't supply the minimum required parameters,
949 blow it off. */
950 for (i = 0; ip->client->config->required_options[i]; i++) {
951 if (!packet->options[ip->client->config->
952 required_options[i]].len) {
953 note("%s isn't satisfactory.", name);
954 return;
955 }
956 }
957
958 /* If we've already seen this lease, don't record it again. */
959 for (lease = ip->client->offered_leases;
960 lease; lease = lease->next) {
961 if (lease->address.len == sizeof(packet->raw->yiaddr) &&
962 !memcmp(lease->address.iabuf,
963 &packet->raw->yiaddr, lease->address.len)) {
964 debug("%s already seen.", name);
965 return;
966 }
967 }
968
969 lease = packet_to_lease(packet);
970 if (!lease) {
971 note("packet_to_lease failed.");
972 return;
973 }
974
975 /* If this lease was acquired through a BOOTREPLY, record that
976 fact. */
977 if (!packet->options[DHO_DHCP_MESSAGE_TYPE].len)
978 lease->is_bootp = 1;
979
980 /* Record the medium under which this lease was offered. */
981 lease->medium = ip->client->medium;
982
983 /* Send out an ARP Request for the offered IP address. */
984 script_init("ARPSEND", lease->medium);
985 script_write_params("check_", lease);
986 /* If the script can't send an ARP request without waiting,
987 we'll be waiting when we do the ARPCHECK, so don't wait now. */
988 if (script_go())
989 arp_timeout_needed = 0;
990 else
991 arp_timeout_needed = 2;
992
993 /* Figure out when we're supposed to stop selecting. */
994 stop_selecting =
995 ip->client->first_sending + ip->client->config->select_interval;
996
997 /* If this is the lease we asked for, put it at the head of the
998 list, and don't mess with the arp request timeout. */
999 if (lease->address.len == ip->client->requested_address.len &&
1000 !memcmp(lease->address.iabuf,
1001 ip->client->requested_address.iabuf,
1002 ip->client->requested_address.len)) {
1003 lease->next = ip->client->offered_leases;
1004 ip->client->offered_leases = lease;
1005 } else {
1006 /* If we already have an offer, and arping for this
1007 offer would take us past the selection timeout,
1008 then don't extend the timeout - just hope for the
1009 best. */
1010 if (ip->client->offered_leases &&
1011 (cur_time + arp_timeout_needed) > stop_selecting)
1012 arp_timeout_needed = 0;
1013
1014 /* Put the lease at the end of the list. */
1015 lease->next = NULL;
1016 if (!ip->client->offered_leases)
1017 ip->client->offered_leases = lease;
1018 else {
1019 for (lp = ip->client->offered_leases; lp->next;
1020 lp = lp->next)
1021 ; /* nothing */
1022 lp->next = lease;
1023 }
1024 }
1025
1026 /* If we're supposed to stop selecting before we've had time
1027 to wait for the ARPREPLY, add some delay to wait for
1028 the ARPREPLY. */
1029 if (stop_selecting - cur_time < arp_timeout_needed)
1030 stop_selecting = cur_time + arp_timeout_needed;
1031
1032 /* If the selecting interval has expired, go immediately to
1033 state_selecting(). Otherwise, time out into
1034 state_selecting at the select interval. */
1035 if (stop_selecting <= 0)
1036 state_selecting(ip);
1037 else {
1038 add_timeout(stop_selecting, state_selecting, ip);
1039 cancel_timeout(send_discover, ip);
1040 }
1041 }
1042
1043 /* Allocate a client_lease structure and initialize it from the parameters
1044 in the specified packet. */
1045
1046 struct client_lease *
packet_to_lease(struct packet * packet)1047 packet_to_lease(struct packet *packet)
1048 {
1049 struct client_lease *lease;
1050 int i;
1051
1052 lease = malloc(sizeof(struct client_lease));
1053
1054 if (!lease) {
1055 warning("dhcpoffer: no memory to record lease.");
1056 return (NULL);
1057 }
1058
1059 memset(lease, 0, sizeof(*lease));
1060
1061 /* Copy the lease options. */
1062 for (i = 0; i < 256; i++) {
1063 if (packet->options[i].len) {
1064 lease->options[i].data =
1065 malloc(packet->options[i].len + 1);
1066 if (!lease->options[i].data) {
1067 warning("dhcpoffer: no memory for option %d", i);
1068 free_client_lease(lease);
1069 return (NULL);
1070 } else {
1071 memcpy(lease->options[i].data,
1072 packet->options[i].data,
1073 packet->options[i].len);
1074 lease->options[i].len =
1075 packet->options[i].len;
1076 lease->options[i].data[lease->options[i].len] =
1077 0;
1078 }
1079 if (!check_option(lease,i)) {
1080 /* ignore a bogus lease offer */
1081 warning("Invalid lease option - ignoring offer");
1082 free_client_lease(lease);
1083 return (NULL);
1084 }
1085 }
1086 }
1087
1088 lease->address.len = sizeof(packet->raw->yiaddr);
1089 memcpy(lease->address.iabuf, &packet->raw->yiaddr, lease->address.len);
1090
1091 lease->nextserver.len = sizeof(packet->raw->siaddr);
1092 memcpy(lease->nextserver.iabuf, &packet->raw->siaddr, lease->nextserver.len);
1093
1094 /* If the server name was filled out, copy it.
1095 Do not attempt to validate the server name as a host name.
1096 RFC 2131 merely states that sname is NUL-terminated (which do
1097 do not assume) and that it is the server's host name. Since
1098 the ISC client and server allow arbitrary characters, we do
1099 as well. */
1100 if ((!packet->options[DHO_DHCP_OPTION_OVERLOAD].len ||
1101 !(packet->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 2)) &&
1102 packet->raw->sname[0]) {
1103 lease->server_name = malloc(DHCP_SNAME_LEN + 1);
1104 if (!lease->server_name) {
1105 warning("dhcpoffer: no memory for server name.");
1106 free_client_lease(lease);
1107 return (NULL);
1108 }
1109 memcpy(lease->server_name, packet->raw->sname, DHCP_SNAME_LEN);
1110 lease->server_name[DHCP_SNAME_LEN]='\0';
1111 }
1112
1113 /* Ditto for the filename. */
1114 if ((!packet->options[DHO_DHCP_OPTION_OVERLOAD].len ||
1115 !(packet->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 1)) &&
1116 packet->raw->file[0]) {
1117 /* Don't count on the NUL terminator. */
1118 lease->filename = malloc(DHCP_FILE_LEN + 1);
1119 if (!lease->filename) {
1120 warning("dhcpoffer: no memory for filename.");
1121 free_client_lease(lease);
1122 return (NULL);
1123 }
1124 memcpy(lease->filename, packet->raw->file, DHCP_FILE_LEN);
1125 lease->filename[DHCP_FILE_LEN]='\0';
1126 }
1127 return lease;
1128 }
1129
1130 void
dhcpnak(struct packet * packet)1131 dhcpnak(struct packet *packet)
1132 {
1133 struct interface_info *ip = packet->interface;
1134
1135 /* If we're not receptive to an offer right now, or if the offer
1136 has an unrecognizable transaction id, then just drop it. */
1137 if (packet->interface->client->xid != packet->raw->xid ||
1138 (packet->interface->hw_address.hlen != packet->raw->hlen) ||
1139 (memcmp(packet->interface->hw_address.haddr,
1140 packet->raw->chaddr, packet->raw->hlen)))
1141 return;
1142
1143 if (ip->client->state != S_REBOOTING &&
1144 ip->client->state != S_REQUESTING &&
1145 ip->client->state != S_RENEWING &&
1146 ip->client->state != S_REBINDING)
1147 return;
1148
1149 note("DHCPNAK from %s", piaddr(packet->client_addr));
1150
1151 if (!ip->client->active) {
1152 note("DHCPNAK with no active lease.\n");
1153 return;
1154 }
1155
1156 free_client_lease(ip->client->active);
1157 ip->client->active = NULL;
1158
1159 /* Stop sending DHCPREQUEST packets... */
1160 cancel_timeout(send_request, ip);
1161
1162 ip->client->state = S_INIT;
1163 state_init(ip);
1164 }
1165
1166 /* Send out a DHCPDISCOVER packet, and set a timeout to send out another
1167 one after the right interval has expired. If we don't get an offer by
1168 the time we reach the panic interval, call the panic function. */
1169
1170 void
send_discover(void * ipp)1171 send_discover(void *ipp)
1172 {
1173 struct interface_info *ip = ipp;
1174 int interval, increase = 1;
1175
1176 /* Figure out how long it's been since we started transmitting. */
1177 interval = cur_time - ip->client->first_sending;
1178
1179 /* If we're past the panic timeout, call the script and tell it
1180 we haven't found anything for this interface yet. */
1181 if (interval > ip->client->config->timeout) {
1182 state_panic(ip);
1183 return;
1184 }
1185
1186 /* If we're selecting media, try the whole list before doing
1187 the exponential backoff, but if we've already received an
1188 offer, stop looping, because we obviously have it right. */
1189 if (!ip->client->offered_leases &&
1190 ip->client->config->media) {
1191 int fail = 0;
1192 again:
1193 if (ip->client->medium) {
1194 ip->client->medium = ip->client->medium->next;
1195 increase = 0;
1196 }
1197 if (!ip->client->medium) {
1198 if (fail)
1199 error("No valid media types for %s!", ip->name);
1200 ip->client->medium = ip->client->config->media;
1201 increase = 1;
1202 }
1203
1204 note("Trying medium \"%s\" %d", ip->client->medium->string,
1205 increase);
1206 script_init("MEDIUM", ip->client->medium);
1207 if (script_go())
1208 goto again;
1209 }
1210
1211 /*
1212 * If we're supposed to increase the interval, do so. If it's
1213 * currently zero (i.e., we haven't sent any packets yet), set
1214 * it to one; otherwise, add to it a random number between zero
1215 * and two times itself. On average, this means that it will
1216 * double with every transmission.
1217 */
1218 if (increase) {
1219 if (!ip->client->interval)
1220 ip->client->interval =
1221 ip->client->config->initial_interval;
1222 else {
1223 ip->client->interval += (arc4random() >> 2) %
1224 (2 * ip->client->interval);
1225 }
1226
1227 /* Don't backoff past cutoff. */
1228 if (ip->client->interval >
1229 ip->client->config->backoff_cutoff)
1230 ip->client->interval =
1231 ((ip->client->config->backoff_cutoff / 2)
1232 + ((arc4random() >> 2) %
1233 ip->client->config->backoff_cutoff));
1234 } else if (!ip->client->interval)
1235 ip->client->interval =
1236 ip->client->config->initial_interval;
1237
1238 /* If the backoff would take us to the panic timeout, just use that
1239 as the interval. */
1240 if (cur_time + ip->client->interval >
1241 ip->client->first_sending + ip->client->config->timeout)
1242 ip->client->interval =
1243 (ip->client->first_sending +
1244 ip->client->config->timeout) - cur_time + 1;
1245
1246 /* Record the number of seconds since we started sending. */
1247 if (interval < 65536)
1248 ip->client->packet.secs = htons(interval);
1249 else
1250 ip->client->packet.secs = htons(65535);
1251 ip->client->secs = ip->client->packet.secs;
1252
1253 note("DHCPDISCOVER on %s to %s port %d interval %d",
1254 ip->name, inet_ntoa(inaddr_broadcast), REMOTE_PORT,
1255 (int)ip->client->interval);
1256
1257 /* Send out a packet. */
1258 send_packet_unpriv(privfd, &ip->client->packet,
1259 ip->client->packet_length, inaddr_any, inaddr_broadcast);
1260
1261 add_timeout(cur_time + ip->client->interval, send_discover, ip);
1262 }
1263
1264 /*
1265 * state_panic gets called if we haven't received any offers in a preset
1266 * amount of time. When this happens, we try to use existing leases
1267 * that haven't yet expired, and failing that, we call the client script
1268 * and hope it can do something.
1269 */
1270 void
state_panic(void * ipp)1271 state_panic(void *ipp)
1272 {
1273 struct interface_info *ip = ipp;
1274 struct client_lease *loop = ip->client->active;
1275 struct client_lease *lp;
1276
1277 note("No DHCPOFFERS received.");
1278
1279 /* We may not have an active lease, but we may have some
1280 predefined leases that we can try. */
1281 if (!ip->client->active && ip->client->leases)
1282 goto activate_next;
1283
1284 /* Run through the list of leases and see if one can be used. */
1285 while (ip->client->active) {
1286 if (ip->client->active->expiry > cur_time) {
1287 note("Trying recorded lease %s",
1288 piaddr(ip->client->active->address));
1289 /* Run the client script with the existing
1290 parameters. */
1291 script_init("TIMEOUT",
1292 ip->client->active->medium);
1293 script_write_params("new_", ip->client->active);
1294 if (ip->client->alias)
1295 script_write_params("alias_",
1296 ip->client->alias);
1297
1298 /* If the old lease is still good and doesn't
1299 yet need renewal, go into BOUND state and
1300 timeout at the renewal time. */
1301 if (!script_go()) {
1302 if (cur_time <
1303 ip->client->active->renewal) {
1304 ip->client->state = S_BOUND;
1305 note("bound: renewal in %d seconds.",
1306 (int)(ip->client->active->renewal -
1307 cur_time));
1308 add_timeout(
1309 ip->client->active->renewal,
1310 state_bound, ip);
1311 } else {
1312 ip->client->state = S_BOUND;
1313 note("bound: immediate renewal.");
1314 state_bound(ip);
1315 }
1316 reinitialize_interfaces();
1317 go_daemon();
1318 return;
1319 }
1320 }
1321
1322 /* If there are no other leases, give up. */
1323 if (!ip->client->leases) {
1324 ip->client->leases = ip->client->active;
1325 ip->client->active = NULL;
1326 break;
1327 }
1328
1329 activate_next:
1330 /* Otherwise, put the active lease at the end of the
1331 lease list, and try another lease.. */
1332 for (lp = ip->client->leases; lp->next; lp = lp->next)
1333 ;
1334 lp->next = ip->client->active;
1335 if (lp->next)
1336 lp->next->next = NULL;
1337 ip->client->active = ip->client->leases;
1338 ip->client->leases = ip->client->leases->next;
1339
1340 /* If we already tried this lease, we've exhausted the
1341 set of leases, so we might as well give up for
1342 now. */
1343 if (ip->client->active == loop)
1344 break;
1345 else if (!loop)
1346 loop = ip->client->active;
1347 }
1348
1349 /* No leases were available, or what was available didn't work, so
1350 tell the shell script that we failed to allocate an address,
1351 and try again later. */
1352 note("No working leases in persistent database - sleeping.\n");
1353 script_init("FAIL", NULL);
1354 if (ip->client->alias)
1355 script_write_params("alias_", ip->client->alias);
1356 script_go();
1357 ip->client->state = S_INIT;
1358 add_timeout(cur_time + ip->client->config->retry_interval, state_init,
1359 ip);
1360 go_daemon();
1361 }
1362
1363 void
send_request(void * ipp)1364 send_request(void *ipp)
1365 {
1366 struct interface_info *ip = ipp;
1367 struct in_addr from, to;
1368 int interval;
1369
1370 /* Figure out how long it's been since we started transmitting. */
1371 interval = cur_time - ip->client->first_sending;
1372
1373 /* If we're in the INIT-REBOOT or REQUESTING state and we're
1374 past the reboot timeout, go to INIT and see if we can
1375 DISCOVER an address... */
1376 /* XXX In the INIT-REBOOT state, if we don't get an ACK, it
1377 means either that we're on a network with no DHCP server,
1378 or that our server is down. In the latter case, assuming
1379 that there is a backup DHCP server, DHCPDISCOVER will get
1380 us a new address, but we could also have successfully
1381 reused our old address. In the former case, we're hosed
1382 anyway. This is not a win-prone situation. */
1383 if ((ip->client->state == S_REBOOTING ||
1384 ip->client->state == S_REQUESTING) &&
1385 interval > ip->client->config->reboot_timeout) {
1386 cancel:
1387 ip->client->state = S_INIT;
1388 cancel_timeout(send_request, ip);
1389 state_init(ip);
1390 return;
1391 }
1392
1393 /* If we're in the reboot state, make sure the media is set up
1394 correctly. */
1395 if (ip->client->state == S_REBOOTING &&
1396 !ip->client->medium &&
1397 ip->client->active->medium ) {
1398 script_init("MEDIUM", ip->client->active->medium);
1399
1400 /* If the medium we chose won't fly, go to INIT state. */
1401 if (script_go())
1402 goto cancel;
1403
1404 /* Record the medium. */
1405 ip->client->medium = ip->client->active->medium;
1406 }
1407
1408 /* If the lease has expired, relinquish the address and go back
1409 to the INIT state. */
1410 if (ip->client->state != S_REQUESTING &&
1411 cur_time > ip->client->active->expiry) {
1412 /* Run the client script with the new parameters. */
1413 script_init("EXPIRE", NULL);
1414 script_write_params("old_", ip->client->active);
1415 if (ip->client->alias)
1416 script_write_params("alias_", ip->client->alias);
1417 script_go();
1418
1419 /* Now do a preinit on the interface so that we can
1420 discover a new address. */
1421 script_init("PREINIT", NULL);
1422 if (ip->client->alias)
1423 script_write_params("alias_", ip->client->alias);
1424 script_go();
1425
1426 ip->client->state = S_INIT;
1427 state_init(ip);
1428 return;
1429 }
1430
1431 /* Do the exponential backoff... */
1432 if (!ip->client->interval)
1433 ip->client->interval = ip->client->config->initial_interval;
1434 else
1435 ip->client->interval += ((arc4random() >> 2) %
1436 (2 * ip->client->interval));
1437
1438 /* Don't backoff past cutoff. */
1439 if (ip->client->interval >
1440 ip->client->config->backoff_cutoff)
1441 ip->client->interval =
1442 ((ip->client->config->backoff_cutoff / 2) +
1443 ((arc4random() >> 2) % ip->client->interval));
1444
1445 /* If the backoff would take us to the expiry time, just set the
1446 timeout to the expiry time. */
1447 if (ip->client->state != S_REQUESTING &&
1448 cur_time + ip->client->interval >
1449 ip->client->active->expiry)
1450 ip->client->interval =
1451 ip->client->active->expiry - cur_time + 1;
1452
1453 /* If the lease T2 time has elapsed, or if we're not yet bound,
1454 broadcast the DHCPREQUEST rather than unicasting. */
1455 if (ip->client->state == S_REQUESTING ||
1456 ip->client->state == S_REBOOTING ||
1457 cur_time > ip->client->active->rebind)
1458 to.s_addr = INADDR_BROADCAST;
1459 else
1460 memcpy(&to.s_addr, ip->client->destination.iabuf,
1461 sizeof(to.s_addr));
1462
1463 if (ip->client->state != S_REQUESTING)
1464 memcpy(&from, ip->client->active->address.iabuf,
1465 sizeof(from));
1466 else
1467 from.s_addr = INADDR_ANY;
1468
1469 /* Record the number of seconds since we started sending. */
1470 if (ip->client->state == S_REQUESTING)
1471 ip->client->packet.secs = ip->client->secs;
1472 else {
1473 if (interval < 65536)
1474 ip->client->packet.secs = htons(interval);
1475 else
1476 ip->client->packet.secs = htons(65535);
1477 }
1478
1479 note("DHCPREQUEST on %s to %s port %d", ip->name, inet_ntoa(to),
1480 REMOTE_PORT);
1481
1482 /* Send out a packet. */
1483 send_packet_unpriv(privfd, &ip->client->packet,
1484 ip->client->packet_length, from, to);
1485
1486 add_timeout(cur_time + ip->client->interval, send_request, ip);
1487 }
1488
1489 void
send_decline(void * ipp)1490 send_decline(void *ipp)
1491 {
1492 struct interface_info *ip = ipp;
1493
1494 note("DHCPDECLINE on %s to %s port %d", ip->name,
1495 inet_ntoa(inaddr_broadcast), REMOTE_PORT);
1496
1497 /* Send out a packet. */
1498 send_packet_unpriv(privfd, &ip->client->packet,
1499 ip->client->packet_length, inaddr_any, inaddr_broadcast);
1500 }
1501
1502 void
make_discover(struct interface_info * ip,struct client_lease * lease)1503 make_discover(struct interface_info *ip, struct client_lease *lease)
1504 {
1505 unsigned char discover = DHCPDISCOVER;
1506 struct tree_cache *options[256];
1507 struct tree_cache option_elements[256];
1508 int i;
1509
1510 memset(option_elements, 0, sizeof(option_elements));
1511 memset(options, 0, sizeof(options));
1512 memset(&ip->client->packet, 0, sizeof(ip->client->packet));
1513
1514 /* Set DHCP_MESSAGE_TYPE to DHCPDISCOVER */
1515 i = DHO_DHCP_MESSAGE_TYPE;
1516 options[i] = &option_elements[i];
1517 options[i]->value = &discover;
1518 options[i]->len = sizeof(discover);
1519 options[i]->buf_size = sizeof(discover);
1520 options[i]->timeout = 0xFFFFFFFF;
1521
1522 /* Request the options we want */
1523 i = DHO_DHCP_PARAMETER_REQUEST_LIST;
1524 options[i] = &option_elements[i];
1525 options[i]->value = ip->client->config->requested_options;
1526 options[i]->len = ip->client->config->requested_option_count;
1527 options[i]->buf_size =
1528 ip->client->config->requested_option_count;
1529 options[i]->timeout = 0xFFFFFFFF;
1530
1531 /* If we had an address, try to get it again. */
1532 if (lease) {
1533 ip->client->requested_address = lease->address;
1534 i = DHO_DHCP_REQUESTED_ADDRESS;
1535 options[i] = &option_elements[i];
1536 options[i]->value = lease->address.iabuf;
1537 options[i]->len = lease->address.len;
1538 options[i]->buf_size = lease->address.len;
1539 options[i]->timeout = 0xFFFFFFFF;
1540 } else
1541 ip->client->requested_address.len = 0;
1542
1543 /* Send any options requested in the config file. */
1544 for (i = 0; i < 256; i++)
1545 if (!options[i] &&
1546 ip->client->config->send_options[i].data) {
1547 options[i] = &option_elements[i];
1548 options[i]->value =
1549 ip->client->config->send_options[i].data;
1550 options[i]->len =
1551 ip->client->config->send_options[i].len;
1552 options[i]->buf_size =
1553 ip->client->config->send_options[i].len;
1554 options[i]->timeout = 0xFFFFFFFF;
1555 }
1556
1557 /* send host name if not set via config file. */
1558 if (!options[DHO_HOST_NAME]) {
1559 if (hostname[0] != '\0') {
1560 size_t len;
1561 char* posDot = strchr(hostname, '.');
1562 if (posDot != NULL)
1563 len = posDot - hostname;
1564 else
1565 len = strlen(hostname);
1566 options[DHO_HOST_NAME] = &option_elements[DHO_HOST_NAME];
1567 options[DHO_HOST_NAME]->value = hostname;
1568 options[DHO_HOST_NAME]->len = len;
1569 options[DHO_HOST_NAME]->buf_size = len;
1570 options[DHO_HOST_NAME]->timeout = 0xFFFFFFFF;
1571 }
1572 }
1573
1574 /* set unique client identifier */
1575 char client_ident[sizeof(struct hardware)];
1576 if (!options[DHO_DHCP_CLIENT_IDENTIFIER]) {
1577 int hwlen = (ip->hw_address.hlen < sizeof(client_ident)-1) ?
1578 ip->hw_address.hlen : sizeof(client_ident)-1;
1579 client_ident[0] = ip->hw_address.htype;
1580 memcpy(&client_ident[1], ip->hw_address.haddr, hwlen);
1581 options[DHO_DHCP_CLIENT_IDENTIFIER] = &option_elements[DHO_DHCP_CLIENT_IDENTIFIER];
1582 options[DHO_DHCP_CLIENT_IDENTIFIER]->value = client_ident;
1583 options[DHO_DHCP_CLIENT_IDENTIFIER]->len = hwlen+1;
1584 options[DHO_DHCP_CLIENT_IDENTIFIER]->buf_size = hwlen+1;
1585 options[DHO_DHCP_CLIENT_IDENTIFIER]->timeout = 0xFFFFFFFF;
1586 }
1587
1588 /* Set up the option buffer... */
1589 ip->client->packet_length = cons_options(NULL, &ip->client->packet, 0,
1590 options, 0, 0, 0, NULL, 0);
1591 if (ip->client->packet_length < BOOTP_MIN_LEN)
1592 ip->client->packet_length = BOOTP_MIN_LEN;
1593
1594 ip->client->packet.op = BOOTREQUEST;
1595 ip->client->packet.htype = ip->hw_address.htype;
1596 ip->client->packet.hlen = ip->hw_address.hlen;
1597 ip->client->packet.hops = 0;
1598 ip->client->packet.xid = arc4random();
1599 ip->client->packet.secs = 0; /* filled in by send_discover. */
1600 ip->client->packet.flags = 0;
1601
1602 memset(&(ip->client->packet.ciaddr),
1603 0, sizeof(ip->client->packet.ciaddr));
1604 memset(&(ip->client->packet.yiaddr),
1605 0, sizeof(ip->client->packet.yiaddr));
1606 memset(&(ip->client->packet.siaddr),
1607 0, sizeof(ip->client->packet.siaddr));
1608 memset(&(ip->client->packet.giaddr),
1609 0, sizeof(ip->client->packet.giaddr));
1610 memcpy(ip->client->packet.chaddr,
1611 ip->hw_address.haddr, ip->hw_address.hlen);
1612 }
1613
1614
1615 void
make_request(struct interface_info * ip,struct client_lease * lease)1616 make_request(struct interface_info *ip, struct client_lease * lease)
1617 {
1618 unsigned char request = DHCPREQUEST;
1619 struct tree_cache *options[256];
1620 struct tree_cache option_elements[256];
1621 int i;
1622
1623 memset(options, 0, sizeof(options));
1624 memset(&ip->client->packet, 0, sizeof(ip->client->packet));
1625
1626 /* Set DHCP_MESSAGE_TYPE to DHCPREQUEST */
1627 i = DHO_DHCP_MESSAGE_TYPE;
1628 options[i] = &option_elements[i];
1629 options[i]->value = &request;
1630 options[i]->len = sizeof(request);
1631 options[i]->buf_size = sizeof(request);
1632 options[i]->timeout = 0xFFFFFFFF;
1633
1634 /* Request the options we want */
1635 i = DHO_DHCP_PARAMETER_REQUEST_LIST;
1636 options[i] = &option_elements[i];
1637 options[i]->value = ip->client->config->requested_options;
1638 options[i]->len = ip->client->config->requested_option_count;
1639 options[i]->buf_size =
1640 ip->client->config->requested_option_count;
1641 options[i]->timeout = 0xFFFFFFFF;
1642
1643 /* If we are requesting an address that hasn't yet been assigned
1644 to us, use the DHCP Requested Address option. */
1645 if (ip->client->state == S_REQUESTING) {
1646 /* Send back the server identifier... */
1647 i = DHO_DHCP_SERVER_IDENTIFIER;
1648 options[i] = &option_elements[i];
1649 options[i]->value = lease->options[i].data;
1650 options[i]->len = lease->options[i].len;
1651 options[i]->buf_size = lease->options[i].len;
1652 options[i]->timeout = 0xFFFFFFFF;
1653 }
1654 if (ip->client->state == S_REQUESTING ||
1655 ip->client->state == S_REBOOTING) {
1656 ip->client->requested_address = lease->address;
1657 i = DHO_DHCP_REQUESTED_ADDRESS;
1658 options[i] = &option_elements[i];
1659 options[i]->value = lease->address.iabuf;
1660 options[i]->len = lease->address.len;
1661 options[i]->buf_size = lease->address.len;
1662 options[i]->timeout = 0xFFFFFFFF;
1663 } else
1664 ip->client->requested_address.len = 0;
1665
1666 /* Send any options requested in the config file. */
1667 for (i = 0; i < 256; i++)
1668 if (!options[i] &&
1669 ip->client->config->send_options[i].data) {
1670 options[i] = &option_elements[i];
1671 options[i]->value =
1672 ip->client->config->send_options[i].data;
1673 options[i]->len =
1674 ip->client->config->send_options[i].len;
1675 options[i]->buf_size =
1676 ip->client->config->send_options[i].len;
1677 options[i]->timeout = 0xFFFFFFFF;
1678 }
1679
1680 /* send host name if not set via config file. */
1681 if (!options[DHO_HOST_NAME]) {
1682 if (hostname[0] != '\0') {
1683 size_t len;
1684 char* posDot = strchr(hostname, '.');
1685 if (posDot != NULL)
1686 len = posDot - hostname;
1687 else
1688 len = strlen(hostname);
1689 options[DHO_HOST_NAME] = &option_elements[DHO_HOST_NAME];
1690 options[DHO_HOST_NAME]->value = hostname;
1691 options[DHO_HOST_NAME]->len = len;
1692 options[DHO_HOST_NAME]->buf_size = len;
1693 options[DHO_HOST_NAME]->timeout = 0xFFFFFFFF;
1694 }
1695 }
1696
1697 /* set unique client identifier */
1698 char client_ident[sizeof(struct hardware)];
1699 if (!options[DHO_DHCP_CLIENT_IDENTIFIER]) {
1700 int hwlen = (ip->hw_address.hlen < sizeof(client_ident)-1) ?
1701 ip->hw_address.hlen : sizeof(client_ident)-1;
1702 client_ident[0] = ip->hw_address.htype;
1703 memcpy(&client_ident[1], ip->hw_address.haddr, hwlen);
1704 options[DHO_DHCP_CLIENT_IDENTIFIER] = &option_elements[DHO_DHCP_CLIENT_IDENTIFIER];
1705 options[DHO_DHCP_CLIENT_IDENTIFIER]->value = client_ident;
1706 options[DHO_DHCP_CLIENT_IDENTIFIER]->len = hwlen+1;
1707 options[DHO_DHCP_CLIENT_IDENTIFIER]->buf_size = hwlen+1;
1708 options[DHO_DHCP_CLIENT_IDENTIFIER]->timeout = 0xFFFFFFFF;
1709 }
1710
1711 /* Set up the option buffer... */
1712 ip->client->packet_length = cons_options(NULL, &ip->client->packet, 0,
1713 options, 0, 0, 0, NULL, 0);
1714 if (ip->client->packet_length < BOOTP_MIN_LEN)
1715 ip->client->packet_length = BOOTP_MIN_LEN;
1716
1717 ip->client->packet.op = BOOTREQUEST;
1718 ip->client->packet.htype = ip->hw_address.htype;
1719 ip->client->packet.hlen = ip->hw_address.hlen;
1720 ip->client->packet.hops = 0;
1721 ip->client->packet.xid = ip->client->xid;
1722 ip->client->packet.secs = 0; /* Filled in by send_request. */
1723
1724 /* If we own the address we're requesting, put it in ciaddr;
1725 otherwise set ciaddr to zero. */
1726 if (ip->client->state == S_BOUND ||
1727 ip->client->state == S_RENEWING ||
1728 ip->client->state == S_REBINDING) {
1729 memcpy(&ip->client->packet.ciaddr,
1730 lease->address.iabuf, lease->address.len);
1731 ip->client->packet.flags = 0;
1732 } else {
1733 memset(&ip->client->packet.ciaddr, 0,
1734 sizeof(ip->client->packet.ciaddr));
1735 ip->client->packet.flags = 0;
1736 }
1737
1738 memset(&ip->client->packet.yiaddr, 0,
1739 sizeof(ip->client->packet.yiaddr));
1740 memset(&ip->client->packet.siaddr, 0,
1741 sizeof(ip->client->packet.siaddr));
1742 memset(&ip->client->packet.giaddr, 0,
1743 sizeof(ip->client->packet.giaddr));
1744 memcpy(ip->client->packet.chaddr,
1745 ip->hw_address.haddr, ip->hw_address.hlen);
1746 }
1747
1748 void
make_decline(struct interface_info * ip,struct client_lease * lease)1749 make_decline(struct interface_info *ip, struct client_lease *lease)
1750 {
1751 struct tree_cache *options[256], message_type_tree;
1752 struct tree_cache requested_address_tree;
1753 struct tree_cache server_id_tree, client_id_tree;
1754 unsigned char decline = DHCPDECLINE;
1755 int i;
1756
1757 memset(options, 0, sizeof(options));
1758 memset(&ip->client->packet, 0, sizeof(ip->client->packet));
1759
1760 /* Set DHCP_MESSAGE_TYPE to DHCPDECLINE */
1761 i = DHO_DHCP_MESSAGE_TYPE;
1762 options[i] = &message_type_tree;
1763 options[i]->value = &decline;
1764 options[i]->len = sizeof(decline);
1765 options[i]->buf_size = sizeof(decline);
1766 options[i]->timeout = 0xFFFFFFFF;
1767
1768 /* Send back the server identifier... */
1769 i = DHO_DHCP_SERVER_IDENTIFIER;
1770 options[i] = &server_id_tree;
1771 options[i]->value = lease->options[i].data;
1772 options[i]->len = lease->options[i].len;
1773 options[i]->buf_size = lease->options[i].len;
1774 options[i]->timeout = 0xFFFFFFFF;
1775
1776 /* Send back the address we're declining. */
1777 i = DHO_DHCP_REQUESTED_ADDRESS;
1778 options[i] = &requested_address_tree;
1779 options[i]->value = lease->address.iabuf;
1780 options[i]->len = lease->address.len;
1781 options[i]->buf_size = lease->address.len;
1782 options[i]->timeout = 0xFFFFFFFF;
1783
1784 /* Send the uid if the user supplied one. */
1785 i = DHO_DHCP_CLIENT_IDENTIFIER;
1786 if (ip->client->config->send_options[i].len) {
1787 options[i] = &client_id_tree;
1788 options[i]->value = ip->client->config->send_options[i].data;
1789 options[i]->len = ip->client->config->send_options[i].len;
1790 options[i]->buf_size = ip->client->config->send_options[i].len;
1791 options[i]->timeout = 0xFFFFFFFF;
1792 }
1793
1794
1795 /* Set up the option buffer... */
1796 ip->client->packet_length = cons_options(NULL, &ip->client->packet, 0,
1797 options, 0, 0, 0, NULL, 0);
1798 if (ip->client->packet_length < BOOTP_MIN_LEN)
1799 ip->client->packet_length = BOOTP_MIN_LEN;
1800
1801 ip->client->packet.op = BOOTREQUEST;
1802 ip->client->packet.htype = ip->hw_address.htype;
1803 ip->client->packet.hlen = ip->hw_address.hlen;
1804 ip->client->packet.hops = 0;
1805 ip->client->packet.xid = ip->client->xid;
1806 ip->client->packet.secs = 0; /* Filled in by send_request. */
1807 ip->client->packet.flags = 0;
1808
1809 /* ciaddr must always be zero. */
1810 memset(&ip->client->packet.ciaddr, 0,
1811 sizeof(ip->client->packet.ciaddr));
1812 memset(&ip->client->packet.yiaddr, 0,
1813 sizeof(ip->client->packet.yiaddr));
1814 memset(&ip->client->packet.siaddr, 0,
1815 sizeof(ip->client->packet.siaddr));
1816 memset(&ip->client->packet.giaddr, 0,
1817 sizeof(ip->client->packet.giaddr));
1818 memcpy(ip->client->packet.chaddr,
1819 ip->hw_address.haddr, ip->hw_address.hlen);
1820 }
1821
1822 void
free_client_lease(struct client_lease * lease)1823 free_client_lease(struct client_lease *lease)
1824 {
1825 int i;
1826
1827 if (lease->server_name)
1828 free(lease->server_name);
1829 if (lease->filename)
1830 free(lease->filename);
1831 for (i = 0; i < 256; i++) {
1832 if (lease->options[i].len)
1833 free(lease->options[i].data);
1834 }
1835 free(lease);
1836 }
1837
1838 FILE *leaseFile;
1839
1840 void
rewrite_client_leases(void)1841 rewrite_client_leases(void)
1842 {
1843 struct client_lease *lp;
1844 cap_rights_t rights;
1845
1846 if (!leaseFile) {
1847 leaseFile = fopen(path_dhclient_db, "w");
1848 if (!leaseFile)
1849 error("can't create %s: %m", path_dhclient_db);
1850 cap_rights_init(&rights, CAP_FCNTL, CAP_FSTAT, CAP_FSYNC,
1851 CAP_FTRUNCATE, CAP_SEEK, CAP_WRITE);
1852 if (cap_rights_limit(fileno(leaseFile), &rights) < 0 &&
1853 errno != ENOSYS) {
1854 error("can't limit lease descriptor: %m");
1855 }
1856 if (cap_fcntls_limit(fileno(leaseFile), CAP_FCNTL_GETFL) < 0 &&
1857 errno != ENOSYS) {
1858 error("can't limit lease descriptor fcntls: %m");
1859 }
1860 } else {
1861 fflush(leaseFile);
1862 rewind(leaseFile);
1863 }
1864
1865 for (lp = ifi->client->leases; lp; lp = lp->next)
1866 write_client_lease(ifi, lp, 1);
1867 if (ifi->client->active)
1868 write_client_lease(ifi, ifi->client->active, 1);
1869
1870 fflush(leaseFile);
1871 ftruncate(fileno(leaseFile), ftello(leaseFile));
1872 fsync(fileno(leaseFile));
1873 }
1874
1875 void
write_client_lease(struct interface_info * ip,struct client_lease * lease,int rewrite)1876 write_client_lease(struct interface_info *ip, struct client_lease *lease,
1877 int rewrite)
1878 {
1879 static int leases_written;
1880 struct tm *t;
1881 int i;
1882
1883 if (!rewrite) {
1884 if (leases_written++ > 20) {
1885 rewrite_client_leases();
1886 leases_written = 0;
1887 }
1888 }
1889
1890 /* If the lease came from the config file, we don't need to stash
1891 a copy in the lease database. */
1892 if (lease->is_static)
1893 return;
1894
1895 if (!leaseFile) { /* XXX */
1896 leaseFile = fopen(path_dhclient_db, "w");
1897 if (!leaseFile)
1898 error("can't create %s: %m", path_dhclient_db);
1899 }
1900
1901 fprintf(leaseFile, "lease {\n");
1902 if (lease->is_bootp)
1903 fprintf(leaseFile, " bootp;\n");
1904 fprintf(leaseFile, " interface \"%s\";\n", ip->name);
1905 fprintf(leaseFile, " fixed-address %s;\n", piaddr(lease->address));
1906 if (lease->nextserver.len == sizeof(inaddr_any) &&
1907 0 != memcmp(lease->nextserver.iabuf, &inaddr_any,
1908 sizeof(inaddr_any)))
1909 fprintf(leaseFile, " next-server %s;\n",
1910 piaddr(lease->nextserver));
1911 if (lease->filename)
1912 fprintf(leaseFile, " filename \"%s\";\n", lease->filename);
1913 if (lease->server_name)
1914 fprintf(leaseFile, " server-name \"%s\";\n",
1915 lease->server_name);
1916 if (lease->medium)
1917 fprintf(leaseFile, " medium \"%s\";\n", lease->medium->string);
1918 for (i = 0; i < 256; i++)
1919 if (lease->options[i].len)
1920 fprintf(leaseFile, " option %s %s;\n",
1921 dhcp_options[i].name,
1922 pretty_print_option(i, lease->options[i].data,
1923 lease->options[i].len, 1, 1));
1924
1925 t = gmtime(&lease->renewal);
1926 fprintf(leaseFile, " renew %d %d/%d/%d %02d:%02d:%02d;\n",
1927 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1928 t->tm_hour, t->tm_min, t->tm_sec);
1929 t = gmtime(&lease->rebind);
1930 fprintf(leaseFile, " rebind %d %d/%d/%d %02d:%02d:%02d;\n",
1931 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1932 t->tm_hour, t->tm_min, t->tm_sec);
1933 t = gmtime(&lease->expiry);
1934 fprintf(leaseFile, " expire %d %d/%d/%d %02d:%02d:%02d;\n",
1935 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1936 t->tm_hour, t->tm_min, t->tm_sec);
1937 fprintf(leaseFile, "}\n");
1938 fflush(leaseFile);
1939 }
1940
1941 void
script_init(char * reason,struct string_list * medium)1942 script_init(char *reason, struct string_list *medium)
1943 {
1944 size_t len, mediumlen = 0;
1945 struct imsg_hdr hdr;
1946 struct buf *buf;
1947 int errs;
1948
1949 if (medium != NULL && medium->string != NULL)
1950 mediumlen = strlen(medium->string);
1951
1952 hdr.code = IMSG_SCRIPT_INIT;
1953 hdr.len = sizeof(struct imsg_hdr) +
1954 sizeof(size_t) + mediumlen +
1955 sizeof(size_t) + strlen(reason);
1956
1957 if ((buf = buf_open(hdr.len)) == NULL)
1958 error("buf_open: %m");
1959
1960 errs = 0;
1961 errs += buf_add(buf, &hdr, sizeof(hdr));
1962 errs += buf_add(buf, &mediumlen, sizeof(mediumlen));
1963 if (mediumlen > 0)
1964 errs += buf_add(buf, medium->string, mediumlen);
1965 len = strlen(reason);
1966 errs += buf_add(buf, &len, sizeof(len));
1967 errs += buf_add(buf, reason, len);
1968
1969 if (errs)
1970 error("buf_add: %m");
1971
1972 if (buf_close(privfd, buf) == -1)
1973 error("buf_close: %m");
1974 }
1975
1976 void
priv_script_init(char * reason,char * medium)1977 priv_script_init(char *reason, char *medium)
1978 {
1979 struct interface_info *ip = ifi;
1980
1981 if (ip) {
1982 ip->client->scriptEnvsize = 100;
1983 if (ip->client->scriptEnv == NULL)
1984 ip->client->scriptEnv =
1985 malloc(ip->client->scriptEnvsize * sizeof(char *));
1986 if (ip->client->scriptEnv == NULL)
1987 error("script_init: no memory for environment");
1988
1989 ip->client->scriptEnv[0] = strdup(CLIENT_PATH);
1990 if (ip->client->scriptEnv[0] == NULL)
1991 error("script_init: no memory for environment");
1992
1993 ip->client->scriptEnv[1] = NULL;
1994
1995 script_set_env(ip->client, "", "interface", ip->name);
1996
1997 if (medium)
1998 script_set_env(ip->client, "", "medium", medium);
1999
2000 script_set_env(ip->client, "", "reason", reason);
2001 }
2002 }
2003
2004 void
priv_script_write_params(char * prefix,struct client_lease * lease)2005 priv_script_write_params(char *prefix, struct client_lease *lease)
2006 {
2007 struct interface_info *ip = ifi;
2008 u_int8_t dbuf[1500], *dp = NULL;
2009 int i, len;
2010 char tbuf[128];
2011
2012 script_set_env(ip->client, prefix, "ip_address",
2013 piaddr(lease->address));
2014
2015 if (ip->client->config->default_actions[DHO_SUBNET_MASK] ==
2016 ACTION_SUPERSEDE) {
2017 dp = ip->client->config->defaults[DHO_SUBNET_MASK].data;
2018 len = ip->client->config->defaults[DHO_SUBNET_MASK].len;
2019 } else {
2020 dp = lease->options[DHO_SUBNET_MASK].data;
2021 len = lease->options[DHO_SUBNET_MASK].len;
2022 }
2023 if (len && (len < sizeof(lease->address.iabuf))) {
2024 struct iaddr netmask, subnet, broadcast;
2025
2026 memcpy(netmask.iabuf, dp, len);
2027 netmask.len = len;
2028 subnet = subnet_number(lease->address, netmask);
2029 if (subnet.len) {
2030 script_set_env(ip->client, prefix, "network_number",
2031 piaddr(subnet));
2032 if (!lease->options[DHO_BROADCAST_ADDRESS].len) {
2033 broadcast = broadcast_addr(subnet, netmask);
2034 if (broadcast.len)
2035 script_set_env(ip->client, prefix,
2036 "broadcast_address",
2037 piaddr(broadcast));
2038 }
2039 }
2040 }
2041
2042 if (lease->filename)
2043 script_set_env(ip->client, prefix, "filename", lease->filename);
2044 if (lease->server_name)
2045 script_set_env(ip->client, prefix, "server_name",
2046 lease->server_name);
2047 for (i = 0; i < 256; i++) {
2048 len = 0;
2049
2050 if (ip->client->config->defaults[i].len) {
2051 if (lease->options[i].len) {
2052 switch (
2053 ip->client->config->default_actions[i]) {
2054 case ACTION_DEFAULT:
2055 dp = lease->options[i].data;
2056 len = lease->options[i].len;
2057 break;
2058 case ACTION_SUPERSEDE:
2059 supersede:
2060 dp = ip->client->
2061 config->defaults[i].data;
2062 len = ip->client->
2063 config->defaults[i].len;
2064 break;
2065 case ACTION_PREPEND:
2066 len = ip->client->
2067 config->defaults[i].len +
2068 lease->options[i].len;
2069 if (len >= sizeof(dbuf)) {
2070 warning("no space to %s %s",
2071 "prepend option",
2072 dhcp_options[i].name);
2073 goto supersede;
2074 }
2075 dp = dbuf;
2076 memcpy(dp,
2077 ip->client->
2078 config->defaults[i].data,
2079 ip->client->
2080 config->defaults[i].len);
2081 memcpy(dp + ip->client->
2082 config->defaults[i].len,
2083 lease->options[i].data,
2084 lease->options[i].len);
2085 dp[len] = '\0';
2086 break;
2087 case ACTION_APPEND:
2088 /*
2089 * When we append, we assume that we're
2090 * appending to text. Some MS servers
2091 * include a NUL byte at the end of
2092 * the search string provided.
2093 */
2094 len = ip->client->
2095 config->defaults[i].len +
2096 lease->options[i].len;
2097 if (len >= sizeof(dbuf)) {
2098 warning("no space to %s %s",
2099 "append option",
2100 dhcp_options[i].name);
2101 goto supersede;
2102 }
2103 memcpy(dbuf,
2104 lease->options[i].data,
2105 lease->options[i].len);
2106 for (dp = dbuf + lease->options[i].len;
2107 dp > dbuf; dp--, len--)
2108 if (dp[-1] != '\0')
2109 break;
2110 memcpy(dp,
2111 ip->client->
2112 config->defaults[i].data,
2113 ip->client->
2114 config->defaults[i].len);
2115 dp = dbuf;
2116 dp[len] = '\0';
2117 }
2118 } else {
2119 dp = ip->client->
2120 config->defaults[i].data;
2121 len = ip->client->
2122 config->defaults[i].len;
2123 }
2124 } else if (lease->options[i].len) {
2125 len = lease->options[i].len;
2126 dp = lease->options[i].data;
2127 } else {
2128 len = 0;
2129 }
2130 if (len) {
2131 char name[256];
2132
2133 if (dhcp_option_ev_name(name, sizeof(name),
2134 &dhcp_options[i]))
2135 script_set_env(ip->client, prefix, name,
2136 pretty_print_option(i, dp, len, 0, 0));
2137 }
2138 }
2139 snprintf(tbuf, sizeof(tbuf), "%d", (int)lease->expiry);
2140 script_set_env(ip->client, prefix, "expiry", tbuf);
2141 }
2142
2143 void
script_write_params(char * prefix,struct client_lease * lease)2144 script_write_params(char *prefix, struct client_lease *lease)
2145 {
2146 size_t fn_len = 0, sn_len = 0, pr_len = 0;
2147 struct imsg_hdr hdr;
2148 struct buf *buf;
2149 int errs, i;
2150
2151 if (lease->filename != NULL)
2152 fn_len = strlen(lease->filename);
2153 if (lease->server_name != NULL)
2154 sn_len = strlen(lease->server_name);
2155 if (prefix != NULL)
2156 pr_len = strlen(prefix);
2157
2158 hdr.code = IMSG_SCRIPT_WRITE_PARAMS;
2159 hdr.len = sizeof(hdr) + sizeof(struct client_lease) +
2160 sizeof(size_t) + fn_len + sizeof(size_t) + sn_len +
2161 sizeof(size_t) + pr_len;
2162
2163 for (i = 0; i < 256; i++)
2164 hdr.len += sizeof(int) + lease->options[i].len;
2165
2166 scripttime = time(NULL);
2167
2168 if ((buf = buf_open(hdr.len)) == NULL)
2169 error("buf_open: %m");
2170
2171 errs = 0;
2172 errs += buf_add(buf, &hdr, sizeof(hdr));
2173 errs += buf_add(buf, lease, sizeof(struct client_lease));
2174 errs += buf_add(buf, &fn_len, sizeof(fn_len));
2175 errs += buf_add(buf, lease->filename, fn_len);
2176 errs += buf_add(buf, &sn_len, sizeof(sn_len));
2177 errs += buf_add(buf, lease->server_name, sn_len);
2178 errs += buf_add(buf, &pr_len, sizeof(pr_len));
2179 errs += buf_add(buf, prefix, pr_len);
2180
2181 for (i = 0; i < 256; i++) {
2182 errs += buf_add(buf, &lease->options[i].len,
2183 sizeof(lease->options[i].len));
2184 errs += buf_add(buf, lease->options[i].data,
2185 lease->options[i].len);
2186 }
2187
2188 if (errs)
2189 error("buf_add: %m");
2190
2191 if (buf_close(privfd, buf) == -1)
2192 error("buf_close: %m");
2193 }
2194
2195 int
script_go(void)2196 script_go(void)
2197 {
2198 struct imsg_hdr hdr;
2199 struct buf *buf;
2200 int ret;
2201
2202 hdr.code = IMSG_SCRIPT_GO;
2203 hdr.len = sizeof(struct imsg_hdr);
2204
2205 if ((buf = buf_open(hdr.len)) == NULL)
2206 error("buf_open: %m");
2207
2208 if (buf_add(buf, &hdr, sizeof(hdr)))
2209 error("buf_add: %m");
2210
2211 if (buf_close(privfd, buf) == -1)
2212 error("buf_close: %m");
2213
2214 bzero(&hdr, sizeof(hdr));
2215 buf_read(privfd, &hdr, sizeof(hdr));
2216 if (hdr.code != IMSG_SCRIPT_GO_RET)
2217 error("unexpected msg type %u", hdr.code);
2218 if (hdr.len != sizeof(hdr) + sizeof(int))
2219 error("received corrupted message");
2220 buf_read(privfd, &ret, sizeof(ret));
2221
2222 scripttime = time(NULL);
2223
2224 return (ret);
2225 }
2226
2227 int
priv_script_go(void)2228 priv_script_go(void)
2229 {
2230 char *scriptName, *argv[2], **envp, *epp[3], reason[] = "REASON=NBI";
2231 static char client_path[] = CLIENT_PATH;
2232 struct interface_info *ip = ifi;
2233 int pid, wpid, wstatus;
2234
2235 scripttime = time(NULL);
2236
2237 if (ip) {
2238 scriptName = ip->client->config->script_name;
2239 envp = ip->client->scriptEnv;
2240 } else {
2241 scriptName = top_level_config.script_name;
2242 epp[0] = reason;
2243 epp[1] = client_path;
2244 epp[2] = NULL;
2245 envp = epp;
2246 }
2247
2248 argv[0] = scriptName;
2249 argv[1] = NULL;
2250
2251 pid = fork();
2252 if (pid < 0) {
2253 error("fork: %m");
2254 wstatus = 0;
2255 } else if (pid) {
2256 do {
2257 wpid = wait(&wstatus);
2258 } while (wpid != pid && wpid > 0);
2259 if (wpid < 0) {
2260 error("wait: %m");
2261 wstatus = 0;
2262 }
2263 } else {
2264 execve(scriptName, argv, envp);
2265 error("execve (%s, ...): %m", scriptName);
2266 }
2267
2268 if (ip)
2269 script_flush_env(ip->client);
2270
2271 return (wstatus & 0xff);
2272 }
2273
2274 void
script_set_env(struct client_state * client,const char * prefix,const char * name,const char * value)2275 script_set_env(struct client_state *client, const char *prefix,
2276 const char *name, const char *value)
2277 {
2278 int i, j, namelen;
2279
2280 namelen = strlen(name);
2281
2282 for (i = 0; client->scriptEnv[i]; i++)
2283 if (strncmp(client->scriptEnv[i], name, namelen) == 0 &&
2284 client->scriptEnv[i][namelen] == '=')
2285 break;
2286
2287 if (client->scriptEnv[i])
2288 /* Reuse the slot. */
2289 free(client->scriptEnv[i]);
2290 else {
2291 /* New variable. Expand if necessary. */
2292 if (i >= client->scriptEnvsize - 1) {
2293 char **newscriptEnv;
2294 int newscriptEnvsize = client->scriptEnvsize + 50;
2295
2296 newscriptEnv = realloc(client->scriptEnv,
2297 newscriptEnvsize);
2298 if (newscriptEnv == NULL) {
2299 free(client->scriptEnv);
2300 client->scriptEnv = NULL;
2301 client->scriptEnvsize = 0;
2302 error("script_set_env: no memory for variable");
2303 }
2304 client->scriptEnv = newscriptEnv;
2305 client->scriptEnvsize = newscriptEnvsize;
2306 }
2307 /* need to set the NULL pointer at end of array beyond
2308 the new slot. */
2309 client->scriptEnv[i + 1] = NULL;
2310 }
2311 /* Allocate space and format the variable in the appropriate slot. */
2312 client->scriptEnv[i] = malloc(strlen(prefix) + strlen(name) + 1 +
2313 strlen(value) + 1);
2314 if (client->scriptEnv[i] == NULL)
2315 error("script_set_env: no memory for variable assignment");
2316
2317 /* No `` or $() command substitution allowed in environment values! */
2318 for (j=0; j < strlen(value); j++)
2319 switch (value[j]) {
2320 case '`':
2321 case '$':
2322 error("illegal character (%c) in value '%s'", value[j],
2323 value);
2324 /* not reached */
2325 }
2326 snprintf(client->scriptEnv[i], strlen(prefix) + strlen(name) +
2327 1 + strlen(value) + 1, "%s%s=%s", prefix, name, value);
2328 }
2329
2330 void
script_flush_env(struct client_state * client)2331 script_flush_env(struct client_state *client)
2332 {
2333 int i;
2334
2335 for (i = 0; client->scriptEnv[i]; i++) {
2336 free(client->scriptEnv[i]);
2337 client->scriptEnv[i] = NULL;
2338 }
2339 client->scriptEnvsize = 0;
2340 }
2341
2342 int
dhcp_option_ev_name(char * buf,size_t buflen,struct option * option)2343 dhcp_option_ev_name(char *buf, size_t buflen, struct option *option)
2344 {
2345 int i;
2346
2347 for (i = 0; option->name[i]; i++) {
2348 if (i + 1 == buflen)
2349 return 0;
2350 if (option->name[i] == '-')
2351 buf[i] = '_';
2352 else
2353 buf[i] = option->name[i];
2354 }
2355
2356 buf[i] = 0;
2357 return 1;
2358 }
2359
2360 void
go_daemon(void)2361 go_daemon(void)
2362 {
2363 static int state = 0;
2364 cap_rights_t rights;
2365
2366 if (no_daemon || state)
2367 return;
2368
2369 state = 1;
2370
2371 /* Stop logging to stderr... */
2372 log_perror = 0;
2373
2374 if (daemon(1, 0) == -1)
2375 error("daemon");
2376
2377 cap_rights_init(&rights);
2378
2379 if (pidfile != NULL) {
2380 pidfile_write(pidfile);
2381 if (cap_rights_limit(pidfile_fileno(pidfile), &rights) < 0 &&
2382 errno != ENOSYS) {
2383 error("can't limit pidfile descriptor: %m");
2384 }
2385 }
2386
2387 /* we are chrooted, daemon(3) fails to open /dev/null */
2388 if (nullfd != -1) {
2389 dup2(nullfd, STDIN_FILENO);
2390 dup2(nullfd, STDOUT_FILENO);
2391 dup2(nullfd, STDERR_FILENO);
2392 close(nullfd);
2393 nullfd = -1;
2394 }
2395
2396 if (cap_rights_limit(STDIN_FILENO, &rights) < 0 && errno != ENOSYS)
2397 error("can't limit stdin: %m");
2398 cap_rights_init(&rights, CAP_WRITE);
2399 if (cap_rights_limit(STDOUT_FILENO, &rights) < 0 && errno != ENOSYS)
2400 error("can't limit stdout: %m");
2401 if (cap_rights_limit(STDERR_FILENO, &rights) < 0 && errno != ENOSYS)
2402 error("can't limit stderr: %m");
2403 }
2404
2405 int
check_option(struct client_lease * l,int option)2406 check_option(struct client_lease *l, int option)
2407 {
2408 char *opbuf;
2409 char *sbuf;
2410
2411 /* we use this, since this is what gets passed to dhclient-script */
2412
2413 opbuf = pretty_print_option(option, l->options[option].data,
2414 l->options[option].len, 0, 0);
2415
2416 sbuf = option_as_string(option, l->options[option].data,
2417 l->options[option].len);
2418
2419 switch (option) {
2420 case DHO_SUBNET_MASK:
2421 case DHO_TIME_SERVERS:
2422 case DHO_NAME_SERVERS:
2423 case DHO_ROUTERS:
2424 case DHO_DOMAIN_NAME_SERVERS:
2425 case DHO_LOG_SERVERS:
2426 case DHO_COOKIE_SERVERS:
2427 case DHO_LPR_SERVERS:
2428 case DHO_IMPRESS_SERVERS:
2429 case DHO_RESOURCE_LOCATION_SERVERS:
2430 case DHO_SWAP_SERVER:
2431 case DHO_BROADCAST_ADDRESS:
2432 case DHO_NIS_SERVERS:
2433 case DHO_NTP_SERVERS:
2434 case DHO_NETBIOS_NAME_SERVERS:
2435 case DHO_NETBIOS_DD_SERVER:
2436 case DHO_FONT_SERVERS:
2437 case DHO_DHCP_SERVER_IDENTIFIER:
2438 case DHO_NISPLUS_SERVERS:
2439 case DHO_MOBILE_IP_HOME_AGENT:
2440 case DHO_SMTP_SERVER:
2441 case DHO_POP_SERVER:
2442 case DHO_NNTP_SERVER:
2443 case DHO_WWW_SERVER:
2444 case DHO_FINGER_SERVER:
2445 case DHO_IRC_SERVER:
2446 case DHO_STREETTALK_SERVER:
2447 case DHO_STREETTALK_DA_SERVER:
2448 if (!ipv4addrs(opbuf)) {
2449 warning("Invalid IP address in option: %s", opbuf);
2450 return (0);
2451 }
2452 return (1) ;
2453 case DHO_HOST_NAME:
2454 case DHO_NIS_DOMAIN:
2455 case DHO_NISPLUS_DOMAIN:
2456 case DHO_TFTP_SERVER_NAME:
2457 if (!res_hnok(sbuf)) {
2458 warning("Bogus Host Name option %d: %s (%s)", option,
2459 sbuf, opbuf);
2460 l->options[option].len = 0;
2461 free(l->options[option].data);
2462 }
2463 return (1);
2464 case DHO_DOMAIN_NAME:
2465 case DHO_DOMAIN_SEARCH:
2466 if (!res_hnok(sbuf)) {
2467 if (!check_search(sbuf)) {
2468 warning("Bogus domain search list %d: %s (%s)",
2469 option, sbuf, opbuf);
2470 l->options[option].len = 0;
2471 free(l->options[option].data);
2472 }
2473 }
2474 return (1);
2475 case DHO_PAD:
2476 case DHO_TIME_OFFSET:
2477 case DHO_BOOT_SIZE:
2478 case DHO_MERIT_DUMP:
2479 case DHO_ROOT_PATH:
2480 case DHO_EXTENSIONS_PATH:
2481 case DHO_IP_FORWARDING:
2482 case DHO_NON_LOCAL_SOURCE_ROUTING:
2483 case DHO_POLICY_FILTER:
2484 case DHO_MAX_DGRAM_REASSEMBLY:
2485 case DHO_DEFAULT_IP_TTL:
2486 case DHO_PATH_MTU_AGING_TIMEOUT:
2487 case DHO_PATH_MTU_PLATEAU_TABLE:
2488 case DHO_INTERFACE_MTU:
2489 case DHO_ALL_SUBNETS_LOCAL:
2490 case DHO_PERFORM_MASK_DISCOVERY:
2491 case DHO_MASK_SUPPLIER:
2492 case DHO_ROUTER_DISCOVERY:
2493 case DHO_ROUTER_SOLICITATION_ADDRESS:
2494 case DHO_STATIC_ROUTES:
2495 case DHO_TRAILER_ENCAPSULATION:
2496 case DHO_ARP_CACHE_TIMEOUT:
2497 case DHO_IEEE802_3_ENCAPSULATION:
2498 case DHO_DEFAULT_TCP_TTL:
2499 case DHO_TCP_KEEPALIVE_INTERVAL:
2500 case DHO_TCP_KEEPALIVE_GARBAGE:
2501 case DHO_VENDOR_ENCAPSULATED_OPTIONS:
2502 case DHO_NETBIOS_NODE_TYPE:
2503 case DHO_NETBIOS_SCOPE:
2504 case DHO_X_DISPLAY_MANAGER:
2505 case DHO_DHCP_REQUESTED_ADDRESS:
2506 case DHO_DHCP_LEASE_TIME:
2507 case DHO_DHCP_OPTION_OVERLOAD:
2508 case DHO_DHCP_MESSAGE_TYPE:
2509 case DHO_DHCP_PARAMETER_REQUEST_LIST:
2510 case DHO_DHCP_MESSAGE:
2511 case DHO_DHCP_MAX_MESSAGE_SIZE:
2512 case DHO_DHCP_RENEWAL_TIME:
2513 case DHO_DHCP_REBINDING_TIME:
2514 case DHO_DHCP_CLASS_IDENTIFIER:
2515 case DHO_DHCP_CLIENT_IDENTIFIER:
2516 case DHO_BOOTFILE_NAME:
2517 case DHO_DHCP_USER_CLASS_ID:
2518 case DHO_END:
2519 return (1);
2520 case DHO_CLASSLESS_ROUTES:
2521 return (check_classless_option(l->options[option].data,
2522 l->options[option].len));
2523 default:
2524 warning("unknown dhcp option value 0x%x", option);
2525 return (unknown_ok);
2526 }
2527 }
2528
2529 /* RFC 3442 The Classless Static Routes option checks */
2530 int
check_classless_option(unsigned char * data,int len)2531 check_classless_option(unsigned char *data, int len)
2532 {
2533 int i = 0;
2534 unsigned char width;
2535 in_addr_t addr, mask;
2536
2537 if (len < 5) {
2538 warning("Too small length: %d", len);
2539 return (0);
2540 }
2541 while(i < len) {
2542 width = data[i++];
2543 if (width == 0) {
2544 i += 4;
2545 continue;
2546 } else if (width < 9) {
2547 addr = (in_addr_t)(data[i] << 24);
2548 i += 1;
2549 } else if (width < 17) {
2550 addr = (in_addr_t)(data[i] << 24) +
2551 (in_addr_t)(data[i + 1] << 16);
2552 i += 2;
2553 } else if (width < 25) {
2554 addr = (in_addr_t)(data[i] << 24) +
2555 (in_addr_t)(data[i + 1] << 16) +
2556 (in_addr_t)(data[i + 2] << 8);
2557 i += 3;
2558 } else if (width < 33) {
2559 addr = (in_addr_t)(data[i] << 24) +
2560 (in_addr_t)(data[i + 1] << 16) +
2561 (in_addr_t)(data[i + 2] << 8) +
2562 data[i + 3];
2563 i += 4;
2564 } else {
2565 warning("Incorrect subnet width: %d", width);
2566 return (0);
2567 }
2568 mask = (in_addr_t)(~0) << (32 - width);
2569 addr = ntohl(addr);
2570 mask = ntohl(mask);
2571
2572 /*
2573 * From RFC 3442:
2574 * ... After deriving a subnet number and subnet mask
2575 * from each destination descriptor, the DHCP client
2576 * MUST zero any bits in the subnet number where the
2577 * corresponding bit in the mask is zero...
2578 */
2579 if ((addr & mask) != addr) {
2580 addr &= mask;
2581 data[i - 1] = (unsigned char)(
2582 (addr >> (((32 - width)/8)*8)) & 0xFF);
2583 }
2584 i += 4;
2585 }
2586 if (i > len) {
2587 warning("Incorrect data length: %d (must be %d)", len, i);
2588 return (0);
2589 }
2590 return (1);
2591 }
2592
2593 int
res_hnok(const char * dn)2594 res_hnok(const char *dn)
2595 {
2596 int pch = PERIOD, ch = *dn++;
2597
2598 while (ch != '\0') {
2599 int nch = *dn++;
2600
2601 if (periodchar(ch)) {
2602 ;
2603 } else if (periodchar(pch)) {
2604 if (!borderchar(ch))
2605 return (0);
2606 } else if (periodchar(nch) || nch == '\0') {
2607 if (!borderchar(ch))
2608 return (0);
2609 } else {
2610 if (!middlechar(ch))
2611 return (0);
2612 }
2613 pch = ch, ch = nch;
2614 }
2615 return (1);
2616 }
2617
2618 int
check_search(const char * srch)2619 check_search(const char *srch)
2620 {
2621 int pch = PERIOD, ch = *srch++;
2622 int domains = 1;
2623
2624 /* 256 char limit re resolv.conf(5) */
2625 if (strlen(srch) > 256)
2626 return (0);
2627
2628 while (whitechar(ch))
2629 ch = *srch++;
2630
2631 while (ch != '\0') {
2632 int nch = *srch++;
2633
2634 if (periodchar(ch) || whitechar(ch)) {
2635 ;
2636 } else if (periodchar(pch)) {
2637 if (!borderchar(ch))
2638 return (0);
2639 } else if (periodchar(nch) || nch == '\0') {
2640 if (!borderchar(ch))
2641 return (0);
2642 } else {
2643 if (!middlechar(ch))
2644 return (0);
2645 }
2646 if (!whitechar(ch)) {
2647 pch = ch;
2648 } else {
2649 while (whitechar(nch)) {
2650 nch = *srch++;
2651 }
2652 if (nch != '\0')
2653 domains++;
2654 pch = PERIOD;
2655 }
2656 ch = nch;
2657 }
2658 /* 6 domain limit re resolv.conf(5) */
2659 if (domains > 6)
2660 return (0);
2661 return (1);
2662 }
2663
2664 /* Does buf consist only of dotted decimal ipv4 addrs?
2665 * return how many if so,
2666 * otherwise, return 0
2667 */
2668 int
ipv4addrs(char * buf)2669 ipv4addrs(char * buf)
2670 {
2671 struct in_addr jnk;
2672 int count = 0;
2673
2674 while (inet_aton(buf, &jnk) == 1){
2675 count++;
2676 while (periodchar(*buf) || digitchar(*buf))
2677 buf++;
2678 if (*buf == '\0')
2679 return (count);
2680 while (*buf == ' ')
2681 buf++;
2682 }
2683 return (0);
2684 }
2685
2686
2687 char *
option_as_string(unsigned int code,unsigned char * data,int len)2688 option_as_string(unsigned int code, unsigned char *data, int len)
2689 {
2690 static char optbuf[32768]; /* XXX */
2691 char *op = optbuf;
2692 int opleft = sizeof(optbuf);
2693 unsigned char *dp = data;
2694
2695 if (code > 255)
2696 error("option_as_string: bad code %d", code);
2697
2698 for (; dp < data + len; dp++) {
2699 if (!isascii(*dp) || !isprint(*dp)) {
2700 if (dp + 1 != data + len || *dp != 0) {
2701 snprintf(op, opleft, "\\%03o", *dp);
2702 op += 4;
2703 opleft -= 4;
2704 }
2705 } else if (*dp == '"' || *dp == '\'' || *dp == '$' ||
2706 *dp == '`' || *dp == '\\') {
2707 *op++ = '\\';
2708 *op++ = *dp;
2709 opleft -= 2;
2710 } else {
2711 *op++ = *dp;
2712 opleft--;
2713 }
2714 }
2715 if (opleft < 1)
2716 goto toobig;
2717 *op = 0;
2718 return optbuf;
2719 toobig:
2720 warning("dhcp option too large");
2721 return "<error>";
2722 }
2723
2724 int
fork_privchld(int fd,int fd2)2725 fork_privchld(int fd, int fd2)
2726 {
2727 struct pollfd pfd[1];
2728 int nfds;
2729
2730 switch (fork()) {
2731 case -1:
2732 error("cannot fork");
2733 case 0:
2734 break;
2735 default:
2736 return (0);
2737 }
2738
2739 setproctitle("%s [priv]", ifi->name);
2740
2741 setsid();
2742 dup2(nullfd, STDIN_FILENO);
2743 dup2(nullfd, STDOUT_FILENO);
2744 dup2(nullfd, STDERR_FILENO);
2745 close(nullfd);
2746 close(fd2);
2747 close(ifi->rfdesc);
2748 ifi->rfdesc = -1;
2749
2750 for (;;) {
2751 pfd[0].fd = fd;
2752 pfd[0].events = POLLIN;
2753 if ((nfds = poll(pfd, 1, INFTIM)) == -1)
2754 if (errno != EINTR)
2755 error("poll error");
2756
2757 if (nfds == 0 || !(pfd[0].revents & POLLIN))
2758 continue;
2759
2760 dispatch_imsg(ifi, fd);
2761 }
2762 }
2763