c396a8a86add0f76b50d9439f0f676cffe87e934
[dragonfly.git] / sbin / dhclient / dhclient.c
1 /*      $OpenBSD: src/sbin/dhclient/dhclient.c,v 1.132 2009/11/12 14:18:45 jsg 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 <ctype.h>
57 #include <poll.h>
58 #include <pwd.h>
59 #include <unistd.h>
60
61 #include "dhcpd.h"
62 #include "privsep.h"
63
64 #define CLIENT_PATH             "PATH=/usr/bin:/usr/sbin:/bin:/sbin"
65 #define DEFAULT_LEASE_TIME      43200   /* 12 hours... */
66 #define TIME_MAX                2147483647
67 #define POLL_FAILURES           10
68 #define POLL_FAILURE_WAIT       1       /* Back off multiplier (seconds) */
69
70 time_t cur_time;
71
72 char *path_dhclient_conf = _PATH_DHCLIENT_CONF;
73 char *path_dhclient_db = NULL;
74
75 int log_perror = 1;
76 int privfd;
77 int nullfd = -1;
78 int no_daemon;
79 int unknown_ok = 1;
80 int routefd = -1;
81
82 struct iaddr iaddr_broadcast = { 4, { 255, 255, 255, 255 } };
83 struct in_addr inaddr_any;
84 struct sockaddr_in sockaddr_broadcast;
85
86 struct interface_info *ifi;
87 struct client_state *client;
88 struct client_config *config;
89
90 int              findproto(char *, int);
91 struct sockaddr *get_ifa(char *, int);
92 void             usage(void);
93 int              check_option(struct client_lease *l, int option);
94 int              ipv4addrs(char * buf);
95 int              res_hnok(const char *dn);
96 char            *option_as_string(unsigned int code, unsigned char *data, int len);
97 int              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
103 time_t  scripttime;
104 static FILE *leaseFile;
105
106 int
107 findproto(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
136 struct sockaddr *
137 get_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 }
154 struct iaddr defaddr = { .len = 4 }; /* NULL is for silence warnings */
155
156 void
157 routehandler(void)
158 {
159         int linkstat;
160         char msg[2048];
161         struct rt_msghdr *rtm;
162         struct if_msghdr *ifm;
163         struct ifa_msghdr *ifam;
164         struct if_announcemsghdr *ifan;
165         struct client_lease *l;
166         time_t t = time(NULL);
167         struct sockaddr *sa;
168         struct iaddr a;
169         ssize_t n;
170         char *errmsg, buf[64];
171
172         do {
173                 n = read(routefd, &msg, sizeof(msg));
174         } while (n == -1 && errno == EINTR);
175
176         rtm = (struct rt_msghdr *)msg;
177         if (n < sizeof(rtm->rtm_msglen) || n < rtm->rtm_msglen ||
178             rtm->rtm_version != RTM_VERSION)
179                 return;
180
181         switch (rtm->rtm_type) {
182         case RTM_NEWADDR:
183                 ifam = (struct ifa_msghdr *)rtm;
184                 if (ifam->ifam_index != ifi->index)
185                         break;
186                 if (findproto((char *)(ifam + 1), ifam->ifam_addrs) != AF_INET)
187                         break;
188                 sa = get_ifa((char *)(ifam + 1), ifam->ifam_addrs);
189                 if (sa == NULL) {
190                         errmsg = "sa == NULL";
191                         goto die;
192                 }
193
194                 if ((a.len = sizeof(struct in_addr)) > sizeof(a.iabuf))
195                         error("king bula sez: len mismatch");
196                 memcpy(a.iabuf, &((struct sockaddr_in *)sa)->sin_addr, a.len);
197                 if (addr_eq(a, defaddr))
198                         break;
199
200                 /* state_panic() can try unexpired existing leases */
201                 if (client->active && addr_eq(a, client->active->address))
202                         break;
203                 for (l = client->leases; l != NULL; l = l->next)
204                         if (addr_eq(a, l->address))
205                                 break;
206
207                 if (l != NULL || (client->alias &&
208                     addr_eq(a, client->alias->address)))
209                         /* new addr is the one we set */
210                         break;
211                 snprintf(buf, sizeof(buf), "%s: %s",
212                     "new address not one we set", piaddr(a));
213                 errmsg = buf;
214                 goto die;
215         case RTM_DELADDR:
216                 ifam = (struct ifa_msghdr *)rtm;
217                 if (ifam->ifam_index != ifi->index)
218                         break;
219                 if (findproto((char *)(ifam + 1), ifam->ifam_addrs) != AF_INET)
220                         break;
221                 /* XXX check addrs like RTM_NEWADDR instead of this? */
222                 if (scripttime == 0 || t < scripttime + 10)
223                         break;
224                 errmsg = "interface address deleted";
225                 goto die;
226         case RTM_IFINFO:
227                 ifm = (struct if_msghdr *)rtm;
228                 if (ifm->ifm_index != ifi->index)
229                         break;
230                 if ((rtm->rtm_flags & RTF_UP) == 0) {
231                         errmsg = "interface down";
232                         goto die;
233                 }
234
235                 linkstat =
236                     LINK_STATE_IS_UP(ifm->ifm_data.ifi_link_state) ? 1 : 0;
237                 if (linkstat != ifi->linkstat) {
238 #ifdef DEBUG
239                         debug("link state %s -> %s",
240                             ifi->linkstat ? "up" : "down",
241                             linkstat ? "up" : "down");
242 #endif
243                         ifi->linkstat = interface_link_status(ifi->name);
244                         if (ifi->linkstat) {
245                                 client->state = S_INIT;
246                                 state_reboot();
247                         }
248                 }
249                 break;
250         case RTM_IFANNOUNCE:
251                 ifan = (struct if_announcemsghdr *)rtm;
252                 if (ifan->ifan_what == IFAN_DEPARTURE &&
253                     ifan->ifan_index == ifi->index) {
254                         errmsg = "interface departure";
255                         goto die;
256                 }
257                 break;
258         default:
259                 break;
260         }
261         return;
262
263 die:
264         script_init("FAIL", NULL);
265         if (client->alias)
266                 script_write_params("alias_", client->alias);
267         script_go();
268         error("routehandler: %s", errmsg);
269 }
270
271 int
272 main(int argc, char *argv[])
273 {
274         int      ch, fd, quiet = 0, i = 0, pipe_fd[2];
275         struct passwd *pw;
276
277         /* Initially, log errors to stderr as well as to syslogd. */
278         openlog(getprogname(), LOG_PID | LOG_NDELAY, DHCPD_LOG_FACILITY);
279         setlogmask(LOG_UPTO(LOG_INFO));
280
281         while ((ch = getopt(argc, argv, "c:dl:qu")) != -1)
282                 switch (ch) {
283                 case 'c':
284                         path_dhclient_conf = optarg;
285                         break;
286                 case 'd':
287                         no_daemon = 1;
288                         break;
289                 case 'l':
290                         path_dhclient_db = optarg;
291                         break;
292                 case 'q':
293                         quiet = 1;
294                         break;
295                 case 'u':
296                         unknown_ok = 0;
297                         break;
298                 default:
299                         usage();
300                 }
301
302         argc -= optind;
303         argv += optind;
304
305         if (argc != 1)
306                 usage();
307
308         ifi = calloc(1, sizeof(*ifi));
309         if (ifi == NULL)
310                 error("ifi calloc");
311         client = calloc(1, sizeof(*client));
312         if (client == NULL)
313                 error("client calloc");
314         config = calloc(1, sizeof(*config));
315         if (config == NULL)
316                 error("config calloc");
317
318         if (strlcpy(ifi->name, argv[0], IFNAMSIZ) >= IFNAMSIZ)
319                 error("Interface name too long");
320         if (path_dhclient_db == NULL && asprintf(&path_dhclient_db, "%s.%s",
321             _PATH_DHCLIENT_DB, ifi->name) == -1)
322                 error("asprintf");
323
324         if (quiet)
325                 log_perror = 0;
326
327         tzset();
328         time(&cur_time);
329
330         memset(&sockaddr_broadcast, 0, sizeof(sockaddr_broadcast));
331         sockaddr_broadcast.sin_family = AF_INET;
332         sockaddr_broadcast.sin_port = htons(REMOTE_PORT);
333         sockaddr_broadcast.sin_addr.s_addr = INADDR_BROADCAST;
334         sockaddr_broadcast.sin_len = sizeof(sockaddr_broadcast);
335         inaddr_any.s_addr = INADDR_ANY;
336
337         read_client_conf();
338
339         if (interface_status(ifi->name) == 0) {
340                 interface_link_forceup(ifi->name);
341                 /* Give it up to 4 seconds of silent grace to find link */
342                 i = -4;
343         } else
344                 i = 0;
345
346         while (!(ifi->linkstat = interface_link_status(ifi->name))) {
347                 if (i == 0)
348                         fprintf(stderr, "%s: no link ...", ifi->name);
349                 else if (i > 0)
350                         fprintf(stderr, ".");
351                 fflush(stderr);
352                 if (++i > config->link_timeout) {
353                         fprintf(stderr, " sleeping\n");
354                         goto dispatch;
355                 }
356                 sleep(1);
357         }
358         if (i > 0)
359                 fprintf(stderr, " got link\n");
360
361  dispatch:
362         if ((nullfd = open(_PATH_DEVNULL, O_RDWR, 0)) == -1)
363                 error("cannot open %s: %m", _PATH_DEVNULL);
364
365         if ((pw = getpwnam("_dhcp")) == NULL)
366                 error("no such user: _dhcp");
367
368         if (pipe(pipe_fd) == -1)
369                 error("pipe");
370
371         fork_privchld(pipe_fd[0], pipe_fd[1]);
372
373         close(pipe_fd[0]);
374         privfd = pipe_fd[1];
375
376         if ((fd = open(path_dhclient_db, O_RDONLY|O_EXLOCK|O_CREAT, 0)) == -1)
377                 error("can't open and lock %s: %m", path_dhclient_db);
378         read_client_leases();
379         if ((leaseFile = fopen(path_dhclient_db, "w")) == NULL)
380                 error("can't open %s: %m", path_dhclient_db);
381         rewrite_client_leases();
382         close(fd);
383
384         priv_script_init("PREINIT", NULL);
385         if (client->alias)
386                 priv_script_write_params("alias_", client->alias);
387         priv_script_go();
388
389         if ((routefd = socket(PF_ROUTE, SOCK_RAW, 0)) == -1)
390                 error("socket(PF_ROUTE, SOCK_RAW): %m");
391
392         /* set up the interface */
393         discover_interface();
394
395         if (chroot(_PATH_VAREMPTY) == -1)
396                 error("chroot");
397         if (chdir("/") == -1)
398                 error("chdir(\"/\")");
399
400         if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1)
401                 error("setresgid");
402         if (setgroups(1, &pw->pw_gid) == -1)
403                 error("setgroups");
404         if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1)
405                 error("setresuid");
406
407         endpwent();
408
409         setproctitle("%s", ifi->name);
410
411         if (ifi->linkstat) {
412                 client->state = S_INIT;
413                 state_reboot();
414         } else
415                 go_daemon();
416
417         dispatch();
418
419         /* not reached */
420         return (0);
421 }
422
423 void
424 usage(void)
425 {
426         fprintf(stderr, "usage: %s [-dqu] [-c file] [-l file] interface\n",
427             getprogname());
428         exit(1);
429 }
430
431 /*
432  * Individual States:
433  *
434  * Each routine is called from the dhclient_state_machine() in one of
435  * these conditions:
436  * -> entering INIT state
437  * -> recvpacket_flag == 0: timeout in this state
438  * -> otherwise: received a packet in this state
439  *
440  * Return conditions as handled by dhclient_state_machine():
441  * Returns 1, sendpacket_flag = 1: send packet, reset timer.
442  * Returns 1, sendpacket_flag = 0: just reset the timer (wait for a milestone).
443  * Returns 0: finish the nap which was interrupted for no good reason.
444  *
445  * Several per-interface variables are used to keep track of the process:
446  *   active_lease: the lease that is being used on the interface
447  *                 (null pointer if not configured yet).
448  *   offered_leases: leases corresponding to DHCPOFFER messages that have
449  *                   been sent to us by DHCP servers.
450  *   acked_leases: leases corresponding to DHCPACK messages that have been
451  *                 sent to us by DHCP servers.
452  *   sendpacket: DHCP packet we're trying to send.
453  *   destination: IP address to send sendpacket to
454  * In addition, there are several relevant per-lease variables.
455  *   T1_expiry, T2_expiry, lease_expiry: lease milestones
456  * In the active lease, these control the process of renewing the lease;
457  * In leases on the acked_leases list, this simply determines when we
458  * can no longer legitimately use the lease.
459  */
460 void
461 state_reboot(void)
462 {
463         /* If we don't remember an active lease, go straight to INIT. */
464         if (!client->active || client->active->is_bootp) {
465                 state_init();
466                 return;
467         }
468
469         /* We are in the rebooting state. */
470         client->state = S_REBOOTING;
471
472         /* make_request doesn't initialize xid because it normally comes
473            from the DHCPDISCOVER, but we haven't sent a DHCPDISCOVER,
474            so pick an xid now. */
475         client->xid = arc4random();
476
477         /* Make a DHCPREQUEST packet, and set appropriate per-interface
478            flags. */
479         make_request(client->active);
480         client->destination = iaddr_broadcast;
481         client->first_sending = cur_time;
482         client->interval = config->initial_interval;
483
484         /* Zap the medium list... */
485         client->medium = NULL;
486
487         /* Send out the first DHCPREQUEST packet. */
488         send_request();
489 }
490
491 /*
492  * Called when a lease has completely expired and we've
493  * been unable to renew it.
494  */
495 void
496 state_init(void)
497 {
498         /* Make a DHCPDISCOVER packet, and set appropriate per-interface
499            flags. */
500         make_discover(client->active);
501         client->xid = client->packet.xid;
502         client->destination = iaddr_broadcast;
503         client->state = S_SELECTING;
504         client->first_sending = cur_time;
505         client->interval = config->initial_interval;
506
507         /* Add an immediate timeout to cause the first DHCPDISCOVER packet
508            to go out. */
509         send_discover();
510 }
511
512 /*
513  * state_selecting is called when one or more DHCPOFFER packets
514  * have been received and a configurable period of time has passed.
515  */
516 void
517 state_selecting(void)
518 {
519         struct client_lease *lp, *next, *picked;
520
521         /* Cancel state_selecting and send_discover timeouts, since either
522            one could have got us here. */
523         cancel_timeout(state_selecting);
524         cancel_timeout(send_discover);
525
526         /* We have received one or more DHCPOFFER packets.   Currently,
527            the only criterion by which we judge leases is whether or
528            not we get a response when we arp for them. */
529         picked = NULL;
530         for (lp = client->offered_leases; lp; lp = next) {
531                 next = lp->next;
532
533                 /* Check to see if we got an ARPREPLY for the address
534                    in this particular lease. */
535                 if (!picked) {
536                         script_init("ARPCHECK", lp->medium);
537                         script_write_params("check_", lp);
538
539                         /* If the ARPCHECK code detects another
540                            machine using the offered address, it exits
541                            nonzero.  We need to send a DHCPDECLINE and
542                            toss the lease. */
543                         if (script_go()) {
544                                 make_decline(lp);
545                                 send_decline();
546                                 goto freeit;
547                         }
548                         picked = lp;
549                         picked->next = NULL;
550                 } else {
551 freeit:
552                         free_client_lease(lp);
553                 }
554         }
555         client->offered_leases = NULL;
556
557         /* If we just tossed all the leases we were offered, go back
558            to square one. */
559         if (!picked) {
560                 client->state = S_INIT;
561                 state_init();
562                 return;
563         }
564
565         /* If it was a BOOTREPLY, we can just take the address right now. */
566         if (!picked->options[DHO_DHCP_MESSAGE_TYPE].len) {
567                 client->new = picked;
568
569                 /* Make up some lease expiry times
570                    XXX these should be configurable. */
571                 client->new->expiry = cur_time + 12000;
572                 client->new->renewal += cur_time + 8000;
573                 client->new->rebind += cur_time + 10000;
574
575                 client->state = S_REQUESTING;
576
577                 /* Bind to the address we received. */
578                 bind_lease();
579                 return;
580         }
581
582         /* Go to the REQUESTING state. */
583         client->destination = iaddr_broadcast;
584         client->state = S_REQUESTING;
585         client->first_sending = cur_time;
586         client->interval = config->initial_interval;
587
588         /* Make a DHCPREQUEST packet from the lease we picked. */
589         make_request(picked);
590         client->xid = client->packet.xid;
591
592         /* Toss the lease we picked - we'll get it back in a DHCPACK. */
593         free_client_lease(picked);
594
595         /* Add an immediate timeout to send the first DHCPREQUEST packet. */
596         send_request();
597 }
598
599 void
600 dhcpack(struct iaddr client_addr, struct option_data *options)
601 {
602         struct client_lease *lease;
603
604
605         if (client->state != S_REBOOTING &&
606             client->state != S_REQUESTING &&
607             client->state != S_RENEWING &&
608             client->state != S_REBINDING)
609                 return;
610
611
612         lease = packet_to_lease(options);
613         if (!lease) {
614                 note("packet_to_lease failed.");
615                 return;
616         }
617
618         client->new = lease;
619
620         /* Stop resending DHCPREQUEST. */
621         cancel_timeout(send_request);
622
623         /* Figure out the lease time. */
624         if (client->new->options[DHO_DHCP_LEASE_TIME].data)
625                 client->new->expiry =
626                     getULong(client->new->options[DHO_DHCP_LEASE_TIME].data);
627         else
628                 client->new->expiry = DEFAULT_LEASE_TIME;
629         /* A number that looks negative here is really just very large,
630            because the lease expiry offset is unsigned. */
631         if (client->new->expiry < 0)
632                 client->new->expiry = TIME_MAX;
633         /* XXX should be fixed by resetting the client state */
634         if (client->new->expiry < 60)
635                 client->new->expiry = 60;
636
637         /* Take the server-provided renewal time if there is one;
638            otherwise figure it out according to the spec. */
639         if (client->new->options[DHO_DHCP_RENEWAL_TIME].len)
640                 client->new->renewal =
641                     getULong(client->new->options[DHO_DHCP_RENEWAL_TIME].data);
642         else
643                 client->new->renewal = client->new->expiry / 2;
644
645         /* Same deal with the rebind time. */
646         if (client->new->options[DHO_DHCP_REBINDING_TIME].len)
647                 client->new->rebind =
648                     getULong(client->new->options[DHO_DHCP_REBINDING_TIME].data);
649         else
650                 client->new->rebind = client->new->renewal +
651                     client->new->renewal / 2 + client->new->renewal / 4;
652
653         client->new->expiry += cur_time;
654         /* Lease lengths can never be negative. */
655         if (client->new->expiry < cur_time)
656                 client->new->expiry = TIME_MAX;
657         client->new->renewal += cur_time;
658         if (client->new->renewal < cur_time)
659                 client->new->renewal = TIME_MAX;
660         client->new->rebind += cur_time;
661         if (client->new->rebind < cur_time)
662                 client->new->rebind = TIME_MAX;
663
664         bind_lease();
665 }
666
667 void
668 bind_lease(void)
669 {
670         /* Remember the medium. */
671         client->new->medium = client->medium;
672
673         /* Write out the new lease. */
674         write_client_lease(client->new, 0);
675
676         /* Run the client script with the new parameters. */
677         script_init((client->state == S_REQUESTING ? "BOUND" :
678             (client->state == S_RENEWING ? "RENEW" :
679             (client->state == S_REBOOTING ? "REBOOT" : "REBIND"))),
680             client->new->medium);
681         if (client->active && client->state != S_REBOOTING)
682                 script_write_params("old_", client->active);
683         script_write_params("new_", client->new);
684         if (client->alias)
685                 script_write_params("alias_", client->alias);
686         script_go();
687
688         /* Replace the old active lease with the new one. */
689         if (client->active)
690                 free_client_lease(client->active);
691         client->active = client->new;
692         client->new = NULL;
693
694         /* Set up a timeout to start the renewal process. */
695         add_timeout(client->active->renewal, state_bound);
696
697         note("bound to %s -- renewal in %ld seconds.",
698             piaddr(client->active->address),
699             client->active->renewal - cur_time);
700         client->state = S_BOUND;
701         reinitialize_interface();
702         go_daemon();
703 }
704
705 /*
706  * state_bound is called when we've successfully bound to a particular
707  * lease, but the renewal time on that lease has expired.   We are
708  * expected to unicast a DHCPREQUEST to the server that gave us our
709  * original lease.
710  */
711 void
712 state_bound(void)
713 {
714         /* T1 has expired. */
715         make_request(client->active);
716         client->xid = client->packet.xid;
717
718         if (client->active->options[DHO_DHCP_SERVER_IDENTIFIER].len == 4) {
719                 memcpy(client->destination.iabuf,
720                     client->active->options[DHO_DHCP_SERVER_IDENTIFIER].data,
721                     4);
722                 client->destination.len = 4;
723         } else
724                 client->destination = iaddr_broadcast;
725
726         client->first_sending = cur_time;
727         client->interval = config->initial_interval;
728         client->state = S_RENEWING;
729
730         /* Send the first packet immediately. */
731         send_request();
732 }
733
734 void
735 dhcpoffer(struct iaddr client_addr, struct option_data *options)
736 {
737         struct client_lease *lease, *lp;
738         int i;
739         int arp_timeout_needed, stop_selecting;
740         char *name = options[DHO_DHCP_MESSAGE_TYPE].len ? "DHCPOFFER" :
741             "BOOTREPLY";
742
743
744         if (client->state != S_SELECTING)
745                 return;
746
747
748         /* If this lease doesn't supply the minimum required parameters,
749            blow it off. */
750         for (i = 0; config->required_options[i]; i++) {
751                 if (!options[config->required_options[i]].len) {
752                         note("%s isn't satisfactory.", name);
753                         return;
754                 }
755         }
756
757         /* If we've already seen this lease, don't record it again. */
758         for (lease = client->offered_leases;
759             lease; lease = lease->next) {
760                 if (lease->address.len == sizeof(client->packet.yiaddr) &&
761                     !memcmp(lease->address.iabuf,
762                     &client->packet.yiaddr, lease->address.len)) {
763 #ifdef DEBUG
764                         debug("%s already seen.", name);
765 #endif
766                         return;
767                 }
768         }
769
770         lease = packet_to_lease(options);
771         if (!lease) {
772                 note("packet_to_lease failed.");
773                 return;
774         }
775
776         /* If this lease was acquired through a BOOTREPLY, record that
777            fact. */
778         if (!options[DHO_DHCP_MESSAGE_TYPE].len)
779                 lease->is_bootp = 1;
780
781         /* Record the medium under which this lease was offered. */
782         lease->medium = client->medium;
783
784         /* Send out an ARP Request for the offered IP address. */
785         script_init("ARPSEND", lease->medium);
786         script_write_params("check_", lease);
787         /* If the script can't send an ARP request without waiting,
788            we'll be waiting when we do the ARPCHECK, so don't wait now. */
789         if (script_go())
790                 arp_timeout_needed = 0;
791         else
792                 arp_timeout_needed = 2;
793
794         /* Figure out when we're supposed to stop selecting. */
795         stop_selecting = client->first_sending + config->select_interval;
796
797         /* If this is the lease we asked for, put it at the head of the
798            list, and don't mess with the arp request timeout. */
799         if (addr_eq(lease->address, client->requested_address)) {
800                 lease->next = client->offered_leases;
801                 client->offered_leases = lease;
802         } else {
803                 /* If we already have an offer, and arping for this
804                    offer would take us past the selection timeout,
805                    then don't extend the timeout - just hope for the
806                    best. */
807                 if (client->offered_leases &&
808                     (cur_time + arp_timeout_needed) > stop_selecting)
809                         arp_timeout_needed = 0;
810
811                 /* Put the lease at the end of the list. */
812                 lease->next = NULL;
813                 if (!client->offered_leases)
814                         client->offered_leases = lease;
815                 else {
816                         for (lp = client->offered_leases; lp->next;
817                             lp = lp->next)
818                                 ;       /* nothing */
819                         lp->next = lease;
820                 }
821         }
822
823         /* If we're supposed to stop selecting before we've had time
824            to wait for the ARPREPLY, add some delay to wait for
825            the ARPREPLY. */
826         if (stop_selecting - cur_time < arp_timeout_needed)
827                 stop_selecting = cur_time + arp_timeout_needed;
828
829         /* If the selecting interval has expired, go immediately to
830            state_selecting().  Otherwise, time out into
831            state_selecting at the select interval. */
832         if (stop_selecting <= 0)
833                 state_selecting();
834         else {
835                 add_timeout(stop_selecting, state_selecting);
836                 cancel_timeout(send_discover);
837         }
838 }
839
840 /*
841  * Allocate a client_lease structure and initialize it from the
842  * parameters in the specified packet.
843  */
844 struct client_lease *
845 packet_to_lease(struct option_data *options)
846 {
847         struct client_lease *lease;
848         int i;
849
850         lease = malloc(sizeof(struct client_lease));
851
852         if (!lease) {
853                 warning("dhcpoffer: no memory to record lease.");
854                 return (NULL);
855         }
856
857         memset(lease, 0, sizeof(*lease));
858
859         /* Copy the lease options. */
860         for (i = 0; i < 256; i++) {
861                 if (options[i].len) {
862                         lease->options[i] = options[i];
863                         options[i].data = NULL;
864                         options[i].len = 0;
865                         if (!check_option(lease, i)) {
866                                 warning("Invalid lease option - ignoring offer");
867                                 free_client_lease(lease);
868                                 return (NULL);
869                         }
870                 }
871         }
872
873         lease->address.len = sizeof(client->packet.yiaddr);
874         memcpy(lease->address.iabuf, &client->packet.yiaddr,
875             lease->address.len);
876
877         /* If the server name was filled out, copy it. */
878         if ((!lease->options[DHO_DHCP_OPTION_OVERLOAD].len ||
879             !(lease->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 2)) &&
880             client->packet.sname[0]) {
881                 lease->server_name = malloc(DHCP_SNAME_LEN + 1);
882                 if (!lease->server_name) {
883                         warning("dhcpoffer: no memory for server name.");
884                         free_client_lease(lease);
885                         return (NULL);
886                 }
887                 memcpy(lease->server_name, client->packet.sname,
888                     DHCP_SNAME_LEN);
889                 lease->server_name[DHCP_SNAME_LEN] = '\0';
890                 if (!res_hnok(lease->server_name)) {
891                         warning("Bogus server name %s", lease->server_name);
892                         free(lease->server_name);
893                         lease->server_name = NULL;
894                 }
895         }
896
897         /* Ditto for the filename. */
898         if ((!lease->options[DHO_DHCP_OPTION_OVERLOAD].len ||
899             !(lease->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 1)) &&
900             client->packet.file[0]) {
901                 /* Don't count on the NUL terminator. */
902                 lease->filename = malloc(DHCP_FILE_LEN + 1);
903                 if (!lease->filename) {
904                         warning("dhcpoffer: no memory for filename.");
905                         free_client_lease(lease);
906                         return (NULL);
907                 }
908                 memcpy(lease->filename, client->packet.file, DHCP_FILE_LEN);
909                 lease->filename[DHCP_FILE_LEN] = '\0';
910         }
911         return lease;
912 }
913
914 void
915 dhcpnak(struct iaddr client_addr, struct option_data *options)
916 {
917
918         if (client->state != S_REBOOTING &&
919             client->state != S_REQUESTING &&
920             client->state != S_RENEWING &&
921             client->state != S_REBINDING)
922                 return;
923
924
925         if (!client->active) {
926                 note("DHCPNAK with no active lease.");
927                 return;
928         }
929
930         free_client_lease(client->active);
931         client->active = NULL;
932
933         /* Stop sending DHCPREQUEST packets... */
934         cancel_timeout(send_request);
935
936         client->state = S_INIT;
937         state_init();
938 }
939
940 /*
941  * Send out a DHCPDISCOVER packet, and set a timeout to send out another
942  * one after the right interval has expired.  If we don't get an offer by
943  * the time we reach the panic interval, call the panic function.
944  */
945 void
946 send_discover(void)
947 {
948         int interval, increase = 1;
949
950         /* Figure out how long it's been since we started transmitting. */
951         interval = cur_time - client->first_sending;
952
953         /* If we're past the panic timeout, call the script and tell it
954            we haven't found anything for this interface yet. */
955         if (interval > config->timeout) {
956                 state_panic();
957                 return;
958         }
959
960         /* If we're selecting media, try the whole list before doing
961            the exponential backoff, but if we've already received an
962            offer, stop looping, because we obviously have it right. */
963         if (!client->offered_leases && config->media) {
964                 int fail = 0;
965 again:
966                 if (client->medium) {
967                         client->medium = client->medium->next;
968                         increase = 0;
969                 }
970                 if (!client->medium) {
971                         if (fail)
972                                 error("No valid media types for %s!", ifi->name);
973                         client->medium = config->media;
974                         increase = 1;
975                 }
976
977                 note("Trying medium \"%s\" %d", client->medium->string,
978                     increase);
979                 script_init("MEDIUM", client->medium);
980                 if (script_go())
981                         goto again;
982         }
983
984         /*
985          * If we're supposed to increase the interval, do so.  If it's
986          * currently zero (i.e., we haven't sent any packets yet), set
987          * it to initial_interval; otherwise, add to it a random
988          * number between zero and two times itself.  On average, this
989          * means that it will double with every transmission.
990          */
991         if (increase) {
992                 if (!client->interval)
993                         client->interval = config->initial_interval;
994                 else {
995                         client->interval += (arc4random() >> 2) %
996                             (2 * client->interval);
997                 }
998
999                 /* Don't backoff past cutoff. */
1000                 if (client->interval > config->backoff_cutoff)
1001                         client->interval = ((config->backoff_cutoff / 2)
1002                                  + ((arc4random() >> 2) %
1003                                     config->backoff_cutoff));
1004         } else if (!client->interval)
1005                 client->interval = config->initial_interval;
1006
1007         /* If the backoff would take us to the panic timeout, just use that
1008            as the interval. */
1009         if (cur_time + client->interval >
1010             client->first_sending + config->timeout)
1011                 client->interval = (client->first_sending +
1012                          config->timeout) - cur_time + 1;
1013
1014         /* Record the number of seconds since we started sending. */
1015         if (interval < 65536)
1016                 client->packet.secs = htons(interval);
1017         else
1018                 client->packet.secs = htons(65535);
1019         client->secs = client->packet.secs;
1020
1021         note("DHCPDISCOVER on %s to %s port %d interval %ld",
1022             ifi->name, inet_ntoa(sockaddr_broadcast.sin_addr),
1023             ntohs(sockaddr_broadcast.sin_port), client->interval);
1024
1025         /* Send out a packet. */
1026         send_packet(inaddr_any, &sockaddr_broadcast, NULL);
1027
1028         add_timeout(cur_time + client->interval, send_discover);
1029 }
1030
1031 /*
1032  * state_panic gets called if we haven't received any offers in a preset
1033  * amount of time.   When this happens, we try to use existing leases
1034  * that haven't yet expired, and failing that, we call the client script
1035  * and hope it can do something.
1036  */
1037 void
1038 state_panic(void)
1039 {
1040         struct client_lease *loop = client->active;
1041         struct client_lease *lp;
1042
1043         note("No DHCPOFFERS received.");
1044
1045         /* We may not have an active lease, but we may have some
1046            predefined leases that we can try. */
1047         if (!client->active && client->leases)
1048                 goto activate_next;
1049
1050         /* Run through the list of leases and see if one can be used. */
1051         while (client->active) {
1052                 if (client->active->expiry > cur_time) {
1053                         note("Trying recorded lease %s",
1054                             piaddr(client->active->address));
1055                         /* Run the client script with the existing
1056                            parameters. */
1057                         script_init("TIMEOUT",
1058                             client->active->medium);
1059                         script_write_params("new_", client->active);
1060                         if (client->alias)
1061                                 script_write_params("alias_",
1062                                     client->alias);
1063
1064                         /* If the old lease is still good and doesn't
1065                            yet need renewal, go into BOUND state and
1066                            timeout at the renewal time. */
1067                         if (!script_go()) {
1068                                 if (cur_time <
1069                                     client->active->renewal) {
1070                                         client->state = S_BOUND;
1071                                         note("bound: renewal in %ld seconds.",
1072                                             client->active->renewal -
1073                                             cur_time);
1074                                         add_timeout(client->active->renewal,
1075                                             state_bound);
1076                                 } else {
1077                                         client->state = S_BOUND;
1078                                         note("bound: immediate renewal.");
1079                                         state_bound();
1080                                 }
1081                                 reinitialize_interface();
1082                                 go_daemon();
1083                                 return;
1084                         }
1085                 }
1086
1087                 /* If there are no other leases, give up. */
1088                 if (!client->leases) {
1089                         client->leases = client->active;
1090                         client->active = NULL;
1091                         break;
1092                 }
1093
1094 activate_next:
1095                 /* Otherwise, put the active lease at the end of the
1096                    lease list, and try another lease.. */
1097                 for (lp = client->leases; lp->next; lp = lp->next)
1098                         ;
1099                 lp->next = client->active;
1100                 if (lp->next)
1101                         lp->next->next = NULL;
1102                 client->active = client->leases;
1103                 client->leases = client->leases->next;
1104
1105                 /* If we already tried this lease, we've exhausted the
1106                    set of leases, so we might as well give up for
1107                    now. */
1108                 if (client->active == loop)
1109                         break;
1110                 else if (!loop)
1111                         loop = client->active;
1112         }
1113
1114         /* No leases were available, or what was available didn't work, so
1115            tell the shell script that we failed to allocate an address,
1116            and try again later. */
1117         note("No working leases in persistent database - sleeping.");
1118         script_init("FAIL", NULL);
1119         if (client->alias)
1120                 script_write_params("alias_", client->alias);
1121         script_go();
1122         client->state = S_INIT;
1123         add_timeout(cur_time + config->retry_interval, state_init);
1124         go_daemon();
1125 }
1126
1127 void
1128 send_request(void)
1129 {
1130         struct sockaddr_in destination;
1131         struct in_addr from;
1132         int interval;
1133
1134         /* Figure out how long it's been since we started transmitting. */
1135         interval = cur_time - client->first_sending;
1136
1137         /* If we're in the INIT-REBOOT or REQUESTING state and we're
1138            past the reboot timeout, go to INIT and see if we can
1139            DISCOVER an address... */
1140         /* XXX In the INIT-REBOOT state, if we don't get an ACK, it
1141            means either that we're on a network with no DHCP server,
1142            or that our server is down.  In the latter case, assuming
1143            that there is a backup DHCP server, DHCPDISCOVER will get
1144            us a new address, but we could also have successfully
1145            reused our old address.  In the former case, we're hosed
1146            anyway.  This is not a win-prone situation. */
1147         if ((client->state == S_REBOOTING ||
1148             client->state == S_REQUESTING) &&
1149             interval > config->reboot_timeout) {
1150 cancel:
1151                 client->state = S_INIT;
1152                 cancel_timeout(send_request);
1153                 state_init();
1154                 return;
1155         }
1156
1157         /* If we're in the reboot state, make sure the media is set up
1158            correctly. */
1159         if (client->state == S_REBOOTING &&
1160             !client->medium &&
1161             client->active->medium) {
1162                 script_init("MEDIUM", client->active->medium);
1163
1164                 /* If the medium we chose won't fly, go to INIT state. */
1165                 if (script_go())
1166                         goto cancel;
1167
1168                 /* Record the medium. */
1169                 client->medium = client->active->medium;
1170         }
1171
1172         /* If the lease has expired, relinquish the address and go back
1173            to the INIT state. */
1174         if (client->state != S_REQUESTING &&
1175             cur_time > client->active->expiry) {
1176                 /* Run the client script with the new parameters. */
1177                 script_init("EXPIRE", NULL);
1178                 script_write_params("old_", client->active);
1179                 if (client->alias)
1180                         script_write_params("alias_", client->alias);
1181                 script_go();
1182
1183                 /* Now do a preinit on the interface so that we can
1184                    discover a new address. */
1185                 script_init("PREINIT", NULL);
1186                 if (client->alias)
1187                         script_write_params("alias_", client->alias);
1188                 script_go();
1189
1190                 client->state = S_INIT;
1191                 state_init();
1192                 return;
1193         }
1194
1195         /* Do the exponential backoff... */
1196         if (!client->interval)
1197                 client->interval = config->initial_interval;
1198         else
1199                 client->interval += ((arc4random() >> 2) %
1200                     (2 * client->interval));
1201
1202         /* Don't backoff past cutoff. */
1203         if (client->interval > config->backoff_cutoff)
1204                 client->interval = ((config->backoff_cutoff / 2) +
1205                     ((arc4random() >> 2) % client->interval));
1206
1207         /* If the backoff would take us to the expiry time, just set the
1208            timeout to the expiry time. */
1209         if (client->state != S_REQUESTING && cur_time + client->interval >
1210             client->active->expiry)
1211                 client->interval = client->active->expiry - cur_time + 1;
1212
1213         /* If the lease T2 time has elapsed, or if we're not yet bound,
1214            broadcast the DHCPREQUEST rather than unicasting. */
1215         memset(&destination, 0, sizeof(destination));
1216         if (client->state == S_REQUESTING ||
1217             client->state == S_REBOOTING ||
1218             cur_time > client->active->rebind)
1219                 destination.sin_addr.s_addr = INADDR_BROADCAST;
1220         else
1221                 memcpy(&destination.sin_addr.s_addr, client->destination.iabuf,
1222                     sizeof(destination.sin_addr.s_addr));
1223         destination.sin_port = htons(REMOTE_PORT);
1224         destination.sin_family = AF_INET;
1225         destination.sin_len = sizeof(destination);
1226
1227         if (client->state != S_REQUESTING)
1228                 memcpy(&from, client->active->address.iabuf, sizeof(from));
1229         else
1230                 from.s_addr = INADDR_ANY;
1231
1232         /* Record the number of seconds since we started sending. */
1233         if (client->state == S_REQUESTING)
1234                 client->packet.secs = client->secs;
1235         else {
1236                 if (interval < 65536)
1237                         client->packet.secs = htons(interval);
1238                 else
1239                         client->packet.secs = htons(65535);
1240         }
1241
1242         note("DHCPREQUEST on %s to %s port %d", ifi->name,
1243             inet_ntoa(destination.sin_addr), ntohs(destination.sin_port));
1244
1245         /* Send out a packet. */
1246         send_packet(from, &destination, NULL);
1247
1248         add_timeout(cur_time + client->interval, send_request);
1249 }
1250
1251 void
1252 send_decline(void)
1253 {
1254         note("DHCPDECLINE on %s to %s port %d", ifi->name,
1255             inet_ntoa(sockaddr_broadcast.sin_addr),
1256             ntohs(sockaddr_broadcast.sin_port));
1257
1258         /* Send out a packet. */
1259         send_packet(inaddr_any, &sockaddr_broadcast, NULL);
1260 }
1261
1262 void
1263 make_discover(struct client_lease *lease)
1264 {
1265         unsigned char discover = DHCPDISCOVER;
1266         struct option_data options[256];
1267         int i;
1268
1269         memset(options, 0, sizeof(options));
1270         memset(&client->packet, 0, sizeof(client->packet));
1271
1272         /* Set DHCP_MESSAGE_TYPE to DHCPDISCOVER */
1273         i = DHO_DHCP_MESSAGE_TYPE;
1274         options[i].data = &discover;
1275         options[i].len = sizeof(discover);
1276
1277         /* Request the options we want */
1278         i  = DHO_DHCP_PARAMETER_REQUEST_LIST;
1279         options[i].data = config->requested_options;
1280         options[i].len = config->requested_option_count;
1281
1282         /* If we had an address, try to get it again. */
1283         if (lease) {
1284                 client->requested_address = lease->address;
1285                 i = DHO_DHCP_REQUESTED_ADDRESS;
1286                 options[i].data = lease->address.iabuf;
1287                 options[i].len = lease->address.len;
1288         } else
1289                 client->requested_address.len = 0;
1290
1291         /* Send any options requested in the config file. */
1292         for (i = 0; i < 256; i++)
1293                 if (!options[i].data &&
1294                     config->send_options[i].data) {
1295                         options[i].data = config->send_options[i].data;
1296                         options[i].len = config->send_options[i].len;
1297                 }
1298
1299         /* Set up the option buffer to fit in a minimal UDP packet. */
1300         i = cons_options(client->packet.options, 576 - DHCP_FIXED_LEN,
1301             options);
1302         if (i == -1 || client->packet.options[i] != DHO_END)
1303                 error("options do not fit in DHCPDISCOVER packet.");
1304         client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1305         if (client->packet_length < BOOTP_MIN_LEN)
1306                 client->packet_length = BOOTP_MIN_LEN;
1307
1308         client->packet.op = BOOTREQUEST;
1309         client->packet.htype = ifi->hw_address.htype;
1310         client->packet.hlen = ifi->hw_address.hlen;
1311         client->packet.hops = 0;
1312         client->packet.xid = arc4random();
1313         client->packet.secs = 0; /* filled in by send_discover. */
1314         client->packet.flags = 0;
1315
1316         memset(&client->packet.ciaddr, 0, sizeof(client->packet.ciaddr));
1317         memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1318         memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1319         memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1320         memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1321             ifi->hw_address.hlen);
1322 }
1323
1324 void
1325 make_request(struct client_lease * lease)
1326 {
1327         unsigned char request = DHCPREQUEST;
1328         struct option_data options[256];
1329         int i;
1330
1331         memset(options, 0, sizeof(options));
1332         memset(&client->packet, 0, sizeof(client->packet));
1333
1334         /* Set DHCP_MESSAGE_TYPE to DHCPREQUEST */
1335         i = DHO_DHCP_MESSAGE_TYPE;
1336         options[i].data = &request;
1337         options[i].len = sizeof(request);
1338
1339         /* Request the options we want */
1340         i = DHO_DHCP_PARAMETER_REQUEST_LIST;
1341         options[i].data = config->requested_options;
1342         options[i].len = config->requested_option_count;
1343
1344         /* If we are requesting an address that hasn't yet been assigned
1345            to us, use the DHCP Requested Address option. */
1346         if (client->state == S_REQUESTING) {
1347                 /* Send back the server identifier... */
1348                 i = DHO_DHCP_SERVER_IDENTIFIER;
1349                 options[i].data = lease->options[i].data;
1350                 options[i].len = lease->options[i].len;
1351         }
1352         if (client->state == S_REQUESTING ||
1353             client->state == S_REBOOTING) {
1354                 client->requested_address = lease->address;
1355                 i = DHO_DHCP_REQUESTED_ADDRESS;
1356                 options[i].data = lease->address.iabuf;
1357                 options[i].len = lease->address.len;
1358         } else
1359                 client->requested_address.len = 0;
1360
1361         /* Send any options requested in the config file. */
1362         for (i = 0; i < 256; i++)
1363                 if (!options[i].data && config->send_options[i].data) {
1364                         options[i].data = config->send_options[i].data;
1365                         options[i].len = config->send_options[i].len;
1366                 }
1367
1368         /* Set up the option buffer to fit in a minimal UDP packet. */
1369         i = cons_options(client->packet.options, 576 - DHCP_FIXED_LEN,
1370             options);
1371         if (i == -1 || client->packet.options[i] != DHO_END)
1372                 error("options do not fit in DHCPREQUEST packet.");
1373         client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1374         if (client->packet_length < BOOTP_MIN_LEN)
1375                 client->packet_length = BOOTP_MIN_LEN;
1376
1377         client->packet.op = BOOTREQUEST;
1378         client->packet.htype = ifi->hw_address.htype;
1379         client->packet.hlen = ifi->hw_address.hlen;
1380         client->packet.hops = 0;
1381         client->packet.xid = client->xid;
1382         client->packet.secs = 0; /* Filled in by send_request. */
1383         client->packet.flags = 0;
1384
1385         /* If we own the address we're requesting, put it in ciaddr;
1386            otherwise set ciaddr to zero. */
1387         if (client->state == S_BOUND ||
1388             client->state == S_RENEWING ||
1389             client->state == S_REBINDING) {
1390                 memcpy(&client->packet.ciaddr,
1391                     lease->address.iabuf, lease->address.len);
1392         } else {
1393                 memset(&client->packet.ciaddr, 0,
1394                     sizeof(client->packet.ciaddr));
1395         }
1396
1397         memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1398         memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1399         memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1400         memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1401             ifi->hw_address.hlen);
1402 }
1403
1404 void
1405 make_decline(struct client_lease *lease)
1406 {
1407         struct option_data options[256];
1408         unsigned char decline = DHCPDECLINE;
1409         int i;
1410
1411         memset(options, 0, sizeof(options));
1412         memset(&client->packet, 0, sizeof(client->packet));
1413
1414         /* Set DHCP_MESSAGE_TYPE to DHCPDECLINE */
1415         i = DHO_DHCP_MESSAGE_TYPE;
1416         options[i].data = &decline;
1417         options[i].len = sizeof(decline);
1418
1419         /* Send back the server identifier... */
1420         i = DHO_DHCP_SERVER_IDENTIFIER;
1421         options[i].data = lease->options[i].data;
1422         options[i].len = lease->options[i].len;
1423
1424         /* Send back the address we're declining. */
1425         i = DHO_DHCP_REQUESTED_ADDRESS;
1426         options[i].data = lease->address.iabuf;
1427         options[i].len = lease->address.len;
1428
1429         /* Send the uid if the user supplied one. */
1430         i = DHO_DHCP_CLIENT_IDENTIFIER;
1431         if (config->send_options[i].len) {
1432                 options[i].data = config->send_options[i].data;
1433                 options[i].len = config->send_options[i].len;
1434         }
1435
1436         /* Set up the option buffer to fit in a minimal UDP packet. */
1437         i = cons_options(client->packet.options, 576 - DHCP_FIXED_LEN,
1438             options);
1439         if (i == -1 || client->packet.options[i] != DHO_END)
1440                 error("options do not fit in DHCPDECLINE packet.");
1441         client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1442         if (client->packet_length < BOOTP_MIN_LEN)
1443                 client->packet_length = BOOTP_MIN_LEN;
1444
1445         client->packet.op = BOOTREQUEST;
1446         client->packet.htype = ifi->hw_address.htype;
1447         client->packet.hlen = ifi->hw_address.hlen;
1448         client->packet.hops = 0;
1449         client->packet.xid = client->xid;
1450         client->packet.secs = 0; /* Filled in by send_request. */
1451         client->packet.flags = 0;
1452
1453         /* ciaddr must always be zero. */
1454         memset(&client->packet.ciaddr, 0, sizeof(client->packet.ciaddr));
1455         memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1456         memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1457         memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1458         memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1459             ifi->hw_address.hlen);
1460 }
1461
1462 void
1463 free_client_lease(struct client_lease *lease)
1464 {
1465         int i;
1466
1467         if (lease->server_name)
1468                 free(lease->server_name);
1469         if (lease->filename)
1470                 free(lease->filename);
1471         for (i = 0; i < 256; i++) {
1472                 if (lease->options[i].len)
1473                         free(lease->options[i].data);
1474         }
1475         free(lease);
1476 }
1477
1478 void
1479 rewrite_client_leases(void)
1480 {
1481         struct client_lease *lp;
1482
1483         if (!leaseFile) /* XXX */
1484                 error("lease file not open");
1485
1486         fflush(leaseFile);
1487         rewind(leaseFile);
1488
1489         for (lp = client->leases; lp; lp = lp->next)
1490                 write_client_lease(lp, 1);
1491         if (client->active)
1492                 write_client_lease(client->active, 1);
1493
1494         fflush(leaseFile);
1495         ftruncate(fileno(leaseFile), ftello(leaseFile));
1496         fsync(fileno(leaseFile));
1497 }
1498
1499 void
1500 write_client_lease(struct client_lease *lease, int rewrite)
1501 {
1502         static int leases_written;
1503         struct tm *t;
1504         int i;
1505
1506         if (!rewrite) {
1507                 if (leases_written++ > 20) {
1508                         rewrite_client_leases();
1509                         leases_written = 0;
1510                 }
1511         }
1512
1513         /* If the lease came from the config file, we don't need to stash
1514            a copy in the lease database. */
1515         if (lease->is_static)
1516                 return;
1517
1518         if (!leaseFile) /* XXX */
1519                 error("lease file not open");
1520
1521         fprintf(leaseFile, "lease {\n");
1522         if (lease->is_bootp)
1523                 fprintf(leaseFile, "  bootp;\n");
1524         fprintf(leaseFile, "  interface \"%s\";\n", ifi->name);
1525         fprintf(leaseFile, "  fixed-address %s;\n", piaddr(lease->address));
1526         if (lease->filename)
1527                 fprintf(leaseFile, "  filename \"%s\";\n", lease->filename);
1528         if (lease->server_name)
1529                 fprintf(leaseFile, "  server-name \"%s\";\n",
1530                     lease->server_name);
1531         if (lease->medium)
1532                 fprintf(leaseFile, "  medium \"%s\";\n", lease->medium->string);
1533         for (i = 0; i < 256; i++)
1534                 if (lease->options[i].len)
1535                         fprintf(leaseFile, "  option %s %s;\n",
1536                             dhcp_options[i].name,
1537                             pretty_print_option(i, lease->options[i].data,
1538                             lease->options[i].len, 1, 1));
1539
1540         t = gmtime(&lease->renewal);
1541         fprintf(leaseFile, "  renew %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->rebind);
1545         fprintf(leaseFile, "  rebind %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         t = gmtime(&lease->expiry);
1549         fprintf(leaseFile, "  expire %d %d/%d/%d %02d:%02d:%02d;\n",
1550             t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1551             t->tm_hour, t->tm_min, t->tm_sec);
1552         fprintf(leaseFile, "}\n");
1553         fflush(leaseFile);
1554 }
1555
1556 void
1557 script_init(char *reason, struct string_list *medium)
1558 {
1559         size_t           len, mediumlen = 0;
1560         struct imsg_hdr  hdr;
1561         struct buf      *buf;
1562
1563         if (medium != NULL && medium->string != NULL)
1564                 mediumlen = strlen(medium->string);
1565
1566         hdr.code = IMSG_SCRIPT_INIT;
1567         hdr.len = sizeof(struct imsg_hdr) +
1568             sizeof(size_t) + mediumlen +
1569             sizeof(size_t) + strlen(reason);
1570
1571         buf = buf_open(hdr.len);
1572
1573         buf_add(buf, &hdr, sizeof(hdr));
1574         buf_add(buf, &mediumlen, sizeof(mediumlen));
1575         if (mediumlen > 0)
1576                 buf_add(buf, medium->string, mediumlen);
1577         len = strlen(reason);
1578         buf_add(buf, &len, sizeof(len));
1579         buf_add(buf, reason, len);
1580
1581         buf_close(privfd, buf);
1582 }
1583
1584 void
1585 priv_script_init(char *reason, char *medium)
1586 {
1587         client->scriptEnvsize = 100;
1588         if (client->scriptEnv == NULL)
1589                 client->scriptEnv =
1590                     calloc(client->scriptEnvsize, sizeof(char *));
1591         if (client->scriptEnv == NULL)
1592                 error("script_init: no memory for environment");
1593
1594         client->scriptEnv[0] = strdup(CLIENT_PATH);
1595         if (client->scriptEnv[0] == NULL)
1596                 error("script_init: no memory for environment");
1597
1598         client->scriptEnv[1] = NULL;
1599
1600         script_set_env("", "interface", ifi->name);
1601
1602         if (medium)
1603                 script_set_env("", "medium", medium);
1604
1605         script_set_env("", "reason", reason);
1606 }
1607
1608 void
1609 priv_script_write_params(char *prefix, struct client_lease *lease)
1610 {
1611         u_int8_t dbuf[1500];
1612         int i, len = 0;
1613         char tbuf[128];
1614
1615         script_set_env(prefix, "ip_address", piaddr(lease->address));
1616
1617         if (lease->options[DHO_SUBNET_MASK].len &&
1618             (lease->options[DHO_SUBNET_MASK].len <
1619             sizeof(lease->address.iabuf))) {
1620                 struct iaddr netmask, subnet, broadcast;
1621
1622                 memcpy(netmask.iabuf, lease->options[DHO_SUBNET_MASK].data,
1623                     lease->options[DHO_SUBNET_MASK].len);
1624                 netmask.len = lease->options[DHO_SUBNET_MASK].len;
1625
1626                 subnet = subnet_number(lease->address, netmask);
1627                 if (subnet.len) {
1628                         script_set_env(prefix, "network_number",
1629                             piaddr(subnet));
1630                         if (!lease->options[DHO_BROADCAST_ADDRESS].len) {
1631                                 broadcast = broadcast_addr(subnet, netmask);
1632                                 if (broadcast.len)
1633                                         script_set_env(prefix,
1634                                             "broadcast_address",
1635                                             piaddr(broadcast));
1636                         }
1637                 }
1638         }
1639
1640         if (lease->filename)
1641                 script_set_env(prefix, "filename", lease->filename);
1642         if (lease->server_name)
1643                 script_set_env(prefix, "server_name",
1644                     lease->server_name);
1645         for (i = 0; i < 256; i++) {
1646                 u_int8_t *dp = NULL;
1647
1648                 if (config->defaults[i].len) {
1649                         if (lease->options[i].len) {
1650                                 switch (config->default_actions[i]) {
1651                                 case ACTION_DEFAULT:
1652                                         dp = lease->options[i].data;
1653                                         len = lease->options[i].len;
1654                                         break;
1655                                 case ACTION_SUPERSEDE:
1656 supersede:
1657                                         dp = config->defaults[i].data;
1658                                         len = config->defaults[i].len;
1659                                         break;
1660                                 case ACTION_PREPEND:
1661                                         len = config->defaults[i].len +
1662                                             lease->options[i].len;
1663                                         if (len >= sizeof(dbuf)) {
1664                                                 warning("no space to %s %s",
1665                                                     "prepend option",
1666                                                     dhcp_options[i].name);
1667                                                 goto supersede;
1668                                         }
1669                                         dp = dbuf;
1670                                         memcpy(dp,
1671                                             config->defaults[i].data,
1672                                             config->defaults[i].len);
1673                                         memcpy(dp +
1674                                             config->defaults[i].len,
1675                                             lease->options[i].data,
1676                                             lease->options[i].len);
1677                                         dp[len] = '\0';
1678                                         break;
1679                                 case ACTION_APPEND:
1680                                         len = config->defaults[i].len +
1681                                             lease->options[i].len;
1682                                         if (len >= sizeof(dbuf)) {
1683                                                 warning("no space to %s %s",
1684                                                     "append option",
1685                                                     dhcp_options[i].name);
1686                                                 goto supersede;
1687                                         }
1688                                         dp = dbuf;
1689                                         memcpy(dp, lease->options[i].data,
1690                                             lease->options[i].len);
1691                                         memcpy(dp + lease->options[i].len,
1692                                             config->defaults[i].data,
1693                                             config->defaults[i].len);
1694                                         dp[len] = '\0';
1695                                 }
1696                         } else {
1697                                 dp = config->defaults[i].data;
1698                                 len = config->defaults[i].len;
1699                         }
1700                 } else if (lease->options[i].len) {
1701                         len = lease->options[i].len;
1702                         dp = lease->options[i].data;
1703                 } else {
1704                         len = 0;
1705                 }
1706                 if (len) {
1707                         char name[256];
1708
1709                         if (dhcp_option_ev_name(name, sizeof(name),
1710                             &dhcp_options[i]))
1711                                 script_set_env(prefix, name,
1712                                     pretty_print_option(i, dp, len, 0, 0));
1713                 }
1714         }
1715         snprintf(tbuf, sizeof(tbuf), "%d", (int)lease->expiry);
1716         script_set_env(prefix, "expiry", tbuf);
1717 }
1718
1719 void
1720 script_write_params(char *prefix, struct client_lease *lease)
1721 {
1722         size_t           fn_len = 0, sn_len = 0, pr_len = 0;
1723         struct imsg_hdr  hdr;
1724         struct buf      *buf;
1725         int              i;
1726
1727         if (lease->filename != NULL)
1728                 fn_len = strlen(lease->filename);
1729         if (lease->server_name != NULL)
1730                 sn_len = strlen(lease->server_name);
1731         if (prefix != NULL)
1732                 pr_len = strlen(prefix);
1733
1734         hdr.code = IMSG_SCRIPT_WRITE_PARAMS;
1735         hdr.len = sizeof(hdr) + sizeof(struct client_lease) +
1736             sizeof(size_t) + fn_len + sizeof(size_t) + sn_len +
1737             sizeof(size_t) + pr_len;
1738
1739         for (i = 0; i < 256; i++)
1740                 hdr.len += sizeof(int) + lease->options[i].len;
1741
1742         scripttime = time(NULL);
1743
1744         buf = buf_open(hdr.len);
1745
1746         buf_add(buf, &hdr, sizeof(hdr));
1747         buf_add(buf, lease, sizeof(struct client_lease));
1748         buf_add(buf, &fn_len, sizeof(fn_len));
1749         buf_add(buf, lease->filename, fn_len);
1750         buf_add(buf, &sn_len, sizeof(sn_len));
1751         buf_add(buf, lease->server_name, sn_len);
1752         buf_add(buf, &pr_len, sizeof(pr_len));
1753         buf_add(buf, prefix, pr_len);
1754
1755         for (i = 0; i < 256; i++) {
1756                 buf_add(buf, &lease->options[i].len,
1757                     sizeof(lease->options[i].len));
1758                 buf_add(buf, lease->options[i].data,
1759                     lease->options[i].len);
1760         }
1761
1762         buf_close(privfd, buf);
1763 }
1764
1765 int
1766 script_go(void)
1767 {
1768         struct imsg_hdr  hdr;
1769         struct buf      *buf;
1770         int              ret;
1771
1772         scripttime = time(NULL);
1773
1774         hdr.code = IMSG_SCRIPT_GO;
1775         hdr.len = sizeof(struct imsg_hdr);
1776
1777         buf = buf_open(hdr.len);
1778
1779         buf_add(buf, &hdr, sizeof(hdr));
1780         buf_close(privfd, buf);
1781
1782         bzero(&hdr, sizeof(hdr));
1783         buf_read(privfd, &hdr, sizeof(hdr));
1784         if (hdr.code != IMSG_SCRIPT_GO_RET)
1785                 error("unexpected msg type %u", hdr.code);
1786         if (hdr.len != sizeof(hdr) + sizeof(int))
1787                 error("received corrupted message");
1788         buf_read(privfd, &ret, sizeof(ret));
1789
1790         return (ret);
1791 }
1792
1793 int
1794 priv_script_go(void)
1795 {
1796         char *scriptName, *argv[2], **envp;
1797         int pid, wpid, wstatus;
1798
1799         scripttime = time(NULL);
1800
1801         scriptName = config->script_name;
1802         envp = client->scriptEnv;
1803
1804         argv[0] = scriptName;
1805         argv[1] = NULL;
1806
1807         pid = fork();
1808         if (pid < 0) {
1809                 error("fork: %m");
1810                 wstatus = 0;
1811         } else if (pid) {
1812                 do {
1813                         wpid = wait(&wstatus);
1814                 } while (wpid != pid && wpid > 0);
1815                 if (wpid < 0) {
1816                         error("wait: %m");
1817                         wstatus = 0;
1818                 }
1819         } else {
1820                 execve(scriptName, argv, envp);
1821                 error("execve (%s, ...): %m", scriptName);
1822         }
1823
1824         script_flush_env();
1825
1826         return (WEXITSTATUS(wstatus));
1827 }
1828
1829 void
1830 script_set_env(const char *prefix, const char *name, const char *value)
1831 {
1832         int i, j, namelen;
1833
1834         namelen = strlen(name);
1835
1836         for (i = 0; client->scriptEnv[i]; i++)
1837                 if (strncmp(client->scriptEnv[i], name, namelen) == 0 &&
1838                     client->scriptEnv[i][namelen] == '=')
1839                         break;
1840
1841         if (client->scriptEnv[i])
1842                 /* Reuse the slot. */
1843                 free(client->scriptEnv[i]);
1844         else {
1845                 /* New variable.  Expand if necessary. */
1846                 if (i >= client->scriptEnvsize - 1) {
1847                         char **newscriptEnv;
1848                         int newscriptEnvsize = client->scriptEnvsize + 50;
1849
1850                         newscriptEnv = realloc(client->scriptEnv,
1851                             newscriptEnvsize);
1852                         if (newscriptEnv == NULL) {
1853                                 free(client->scriptEnv);
1854                                 client->scriptEnv = NULL;
1855                                 client->scriptEnvsize = 0;
1856                                 error("script_set_env: no memory for variable");
1857                         }
1858                         client->scriptEnv = newscriptEnv;
1859                         client->scriptEnvsize = newscriptEnvsize;
1860                 }
1861                 /* need to set the NULL pointer at end of array beyond
1862                    the new slot. */
1863                 client->scriptEnv[i + 1] = NULL;
1864         }
1865         /* Allocate space and format the variable in the appropriate slot. */
1866         client->scriptEnv[i] = malloc(strlen(prefix) + strlen(name) + 1 +
1867             strlen(value) + 1);
1868         if (client->scriptEnv[i] == NULL)
1869                 error("script_set_env: no memory for variable assignment");
1870
1871         /* No `` or $() command substitution allowed in environment values! */
1872         for (j = 0; j < strlen(value); j++)
1873                 switch (value[j]) {
1874                 case '`':
1875                 case '$':
1876                         error("illegal character (%c) in value '%s'", value[j],
1877                             value);
1878                         /* not reached */
1879                 }
1880         snprintf(client->scriptEnv[i], strlen(prefix) + strlen(name) +
1881             1 + strlen(value) + 1, "%s%s=%s", prefix, name, value);
1882 }
1883
1884 void
1885 script_flush_env(void)
1886 {
1887         int i;
1888
1889         for (i = 0; client->scriptEnv[i]; i++) {
1890                 free(client->scriptEnv[i]);
1891                 client->scriptEnv[i] = NULL;
1892         }
1893         client->scriptEnvsize = 0;
1894 }
1895
1896 int
1897 dhcp_option_ev_name(char *buf, size_t buflen, const struct option *option)
1898 {
1899         size_t i;
1900
1901         for (i = 0; option->name[i]; i++) {
1902                 if (i + 1 == buflen)
1903                         return 0;
1904                 if (option->name[i] == '-')
1905                         buf[i] = '_';
1906                 else
1907                         buf[i] = option->name[i];
1908         }
1909
1910         buf[i] = 0;
1911         return 1;
1912 }
1913
1914 void
1915 go_daemon(void)
1916 {
1917         static int state = 0;
1918
1919         if (no_daemon || state)
1920                 return;
1921
1922         state = 1;
1923
1924         /* Stop logging to stderr... */
1925         log_perror = 0;
1926
1927         if (daemon(1, 0) == -1)
1928                 error("daemon");
1929
1930         /* we are chrooted, daemon(3) fails to open /dev/null */
1931         if (nullfd != -1) {
1932                 dup2(nullfd, STDIN_FILENO);
1933                 dup2(nullfd, STDOUT_FILENO);
1934                 dup2(nullfd, STDERR_FILENO);
1935                 close(nullfd);
1936                 nullfd = -1;
1937         }
1938 }
1939
1940 int
1941 check_option(struct client_lease *l, int option)
1942 {
1943         char *opbuf;
1944         char *sbuf;
1945
1946         /* we use this, since this is what gets passed to dhclient-script */
1947
1948         opbuf = pretty_print_option(option, l->options[option].data,
1949             l->options[option].len, 0, 0);
1950
1951         sbuf = option_as_string(option, l->options[option].data,
1952             l->options[option].len);
1953
1954         switch (option) {
1955         case DHO_SUBNET_MASK:
1956         case DHO_TIME_SERVERS:
1957         case DHO_NAME_SERVERS:
1958         case DHO_ROUTERS:
1959         case DHO_DOMAIN_NAME_SERVERS:
1960         case DHO_LOG_SERVERS:
1961         case DHO_COOKIE_SERVERS:
1962         case DHO_LPR_SERVERS:
1963         case DHO_IMPRESS_SERVERS:
1964         case DHO_RESOURCE_LOCATION_SERVERS:
1965         case DHO_SWAP_SERVER:
1966         case DHO_BROADCAST_ADDRESS:
1967         case DHO_NIS_SERVERS:
1968         case DHO_NTP_SERVERS:
1969         case DHO_NETBIOS_NAME_SERVERS:
1970         case DHO_NETBIOS_DD_SERVER:
1971         case DHO_FONT_SERVERS:
1972         case DHO_DHCP_SERVER_IDENTIFIER:
1973                 if (!ipv4addrs(opbuf)) {
1974                         warning("Invalid IP address in option: %s", opbuf);
1975                         return (0);
1976                 }
1977                 return (1);
1978         case DHO_HOST_NAME:
1979         case DHO_DOMAIN_NAME:
1980         case DHO_NIS_DOMAIN:
1981                 if (!res_hnok(sbuf)) {
1982                         warning("Bogus Host Name option %d: %s (%s)", option,
1983                             sbuf, opbuf);
1984                         l->options[option].len = 0;
1985                         free(l->options[option].data);
1986                 }
1987                 return (1);
1988         case DHO_PAD:
1989         case DHO_TIME_OFFSET:
1990         case DHO_BOOT_SIZE:
1991         case DHO_MERIT_DUMP:
1992         case DHO_ROOT_PATH:
1993         case DHO_EXTENSIONS_PATH:
1994         case DHO_IP_FORWARDING:
1995         case DHO_NON_LOCAL_SOURCE_ROUTING:
1996         case DHO_POLICY_FILTER:
1997         case DHO_MAX_DGRAM_REASSEMBLY:
1998         case DHO_DEFAULT_IP_TTL:
1999         case DHO_PATH_MTU_AGING_TIMEOUT:
2000         case DHO_PATH_MTU_PLATEAU_TABLE:
2001         case DHO_INTERFACE_MTU:
2002         case DHO_ALL_SUBNETS_LOCAL:
2003         case DHO_PERFORM_MASK_DISCOVERY:
2004         case DHO_MASK_SUPPLIER:
2005         case DHO_ROUTER_DISCOVERY:
2006         case DHO_ROUTER_SOLICITATION_ADDRESS:
2007         case DHO_STATIC_ROUTES:
2008         case DHO_TRAILER_ENCAPSULATION:
2009         case DHO_ARP_CACHE_TIMEOUT:
2010         case DHO_IEEE802_3_ENCAPSULATION:
2011         case DHO_DEFAULT_TCP_TTL:
2012         case DHO_TCP_KEEPALIVE_INTERVAL:
2013         case DHO_TCP_KEEPALIVE_GARBAGE:
2014         case DHO_VENDOR_ENCAPSULATED_OPTIONS:
2015         case DHO_NETBIOS_NODE_TYPE:
2016         case DHO_NETBIOS_SCOPE:
2017         case DHO_X_DISPLAY_MANAGER:
2018         case DHO_DHCP_REQUESTED_ADDRESS:
2019         case DHO_DHCP_LEASE_TIME:
2020         case DHO_DHCP_OPTION_OVERLOAD:
2021         case DHO_DHCP_MESSAGE_TYPE:
2022         case DHO_DHCP_PARAMETER_REQUEST_LIST:
2023         case DHO_DHCP_MESSAGE:
2024         case DHO_DHCP_MAX_MESSAGE_SIZE:
2025         case DHO_DHCP_RENEWAL_TIME:
2026         case DHO_DHCP_REBINDING_TIME:
2027         case DHO_DHCP_CLASS_IDENTIFIER:
2028         case DHO_DHCP_CLIENT_IDENTIFIER:
2029         case DHO_DHCP_USER_CLASS_ID:
2030         case DHO_END:
2031                 return (1);
2032         default:
2033                 warning("unknown dhcp option value 0x%x", option);
2034                 return (unknown_ok);
2035         }
2036 }
2037
2038 int
2039 res_hnok(const char *name)
2040 {
2041         const char *dn = name;
2042         int pch = '.', ch = *dn++;
2043         int warn = 0;
2044
2045         while (ch != '\0') {
2046                 int nch = *dn++;
2047
2048                 if (ch == '.') {
2049                         ;
2050                 } else if (pch == '.' || nch == '.' || nch == '\0') {
2051                         if (!isalnum(ch))
2052                                 return (0);
2053                 } else if (!isalnum(ch) && ch != '-' && ch != '_')
2054                                 return (0);
2055                 else if (ch == '_' && warn == 0) {
2056                         warning("warning: hostname %s contains an "
2057                             "underscore which violates RFC 952", name);
2058                         warn++;
2059                 }
2060                 pch = ch, ch = nch;
2061         }
2062         return (1);
2063 }
2064
2065 /* Does buf consist only of dotted decimal ipv4 addrs?
2066  * return how many if so,
2067  * otherwise, return 0
2068  */
2069 int
2070 ipv4addrs(char * buf)
2071 {
2072         struct in_addr jnk;
2073         int count = 0;
2074
2075         while (inet_aton(buf, &jnk) == 1){
2076                 count++;
2077                 while (*buf == '.' || isdigit(*buf))
2078                         buf++;
2079                 if (*buf == '\0')
2080                         return (count);
2081                 while (*buf ==  ' ')
2082                         buf++;
2083         }
2084         return (0);
2085 }
2086
2087 char *
2088 option_as_string(unsigned int code, unsigned char *data, int len)
2089 {
2090         static char optbuf[32768]; /* XXX */
2091         char *op = optbuf;
2092         int opleft = sizeof(optbuf);
2093         unsigned char *dp = data;
2094
2095         if (code > 255)
2096                 error("option_as_string: bad code %d", code);
2097
2098         for (; dp < data + len; dp++) {
2099                 if (!isascii(*dp) || !isprint(*dp)) {
2100                         if (dp + 1 != data + len || *dp != 0) {
2101                                 size_t oplen;
2102                                 snprintf(op, opleft, "\\%03o", *dp);
2103                                 oplen = strlen(op);
2104                                 op += oplen;
2105                                 opleft -= oplen;
2106                         }
2107                 } else if (*dp == '"' || *dp == '\'' || *dp == '$' ||
2108                     *dp == '`' || *dp == '\\') {
2109                         *op++ = '\\';
2110                         *op++ = *dp;
2111                         opleft -= 2;
2112                 } else {
2113                         *op++ = *dp;
2114                         opleft--;
2115                 }
2116         }
2117         if (opleft < 1)
2118                 goto toobig;
2119         *op = 0;
2120         return optbuf;
2121 toobig:
2122         warning("dhcp option too large");
2123         return "<error>";
2124 }
2125
2126 int
2127 fork_privchld(int fd, int fd2)
2128 {
2129         struct pollfd pfd[1];
2130         int nfds, pfail = 0;
2131
2132         switch (fork()) {
2133         case -1:
2134                 error("cannot fork");
2135                 break;
2136         case 0:
2137                 break;
2138         default:
2139                 return (0);
2140         }
2141
2142         if (chdir("/") == -1)
2143                 error("chdir(\"/\")");
2144
2145         setproctitle("%s [priv]", ifi->name);
2146
2147         dup2(nullfd, STDIN_FILENO);
2148         dup2(nullfd, STDOUT_FILENO);
2149         dup2(nullfd, STDERR_FILENO);
2150         close(nullfd);
2151         close(fd2);
2152
2153         for (;;) {
2154                 pfd[0].fd = fd;
2155                 pfd[0].events = POLLIN;
2156                 if ((nfds = poll(pfd, 1, INFTIM)) == -1)
2157                         if (errno != EINTR)
2158                                 error("poll error");
2159
2160                 /*
2161                  * Handle temporary errors, but bail if they persist.
2162                  */
2163                 if (nfds == 0 || !(pfd[0].revents & POLLIN)) {
2164                         if (pfail > POLL_FAILURES)
2165                                 error("poll failed > %d times", POLL_FAILURES);
2166                         sleep(pfail * POLL_FAILURE_WAIT);
2167                         pfail++;
2168                         continue;
2169                 }
2170
2171                 dispatch_imsg(fd);
2172         }
2173 }