dhclient - Cancel all timeouts in state_reboot().
[dragonfly.git] / sbin / dhclient / dhclient.c
1 /*      $OpenBSD: src/sbin/dhclient/dhclient.c,v 1.143 2012/06/20 21:53:51 kettenis 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 #include <sys/ioctl.h>
56
57 #include <ctype.h>
58 #include <poll.h>
59 #include <pwd.h>
60 #include <unistd.h>
61
62 #include "dhcpd.h"
63 #include "privsep.h"
64
65 #define CLIENT_PATH             "PATH=/usr/bin:/usr/sbin:/bin:/sbin"
66 #define DEFAULT_LEASE_TIME      43200   /* 12 hours... */
67 #define TIME_MAX                2147483647
68 #define POLL_FAILURES           10
69 #define POLL_FAILURE_WAIT       1       /* Back off multiplier (seconds) */
70
71 time_t cur_time;
72
73 char *path_dhclient_conf = _PATH_DHCLIENT_CONF;
74 char *path_dhclient_db = NULL;
75
76 int log_perror = 1;
77 int privfd;
78 int nullfd = -1;
79 int no_daemon;
80 int unknown_ok = 1;
81 int routefd = -1;
82
83 struct iaddr iaddr_broadcast = { 4, { 255, 255, 255, 255 } };
84 struct in_addr inaddr_any;
85 struct sockaddr_in sockaddr_broadcast;
86
87 struct interface_info *ifi;
88 struct client_state *client;
89 struct client_config *config;
90
91 int              findproto(char *, int);
92 struct sockaddr *get_ifa(char *, int);
93 void             usage(void);
94 int              check_option(struct client_lease *l, int option);
95 int              ipv4addrs(char * buf);
96 int              res_hnok(const char *dn);
97 char            *option_as_string(unsigned int code, unsigned char *data, int len);
98 int              fork_privchld(int, int);
99 void             get_ifname(char *, char *);
100 #define ROUNDUP(a) \
101             ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
102 #define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))
103
104 time_t  scripttime;
105 static FILE *leaseFile;
106
107 int
108 findproto(char *cp, int n)
109 {
110         struct sockaddr *sa;
111         int i;
112
113         if (n == 0)
114                 return -1;
115         for (i = 1; i; i <<= 1) {
116                 if (i & n) {
117                         sa = (struct sockaddr *)cp;
118                         switch (i) {
119                         case RTA_IFA:
120                         case RTA_DST:
121                         case RTA_GATEWAY:
122                         case RTA_NETMASK:
123                                 if (sa->sa_family == AF_INET)
124                                         return AF_INET;
125                                 if (sa->sa_family == AF_INET6)
126                                         return AF_INET6;
127                                 break;
128                         case RTA_IFP:
129                                 break;
130                         }
131                         ADVANCE(cp, sa);
132                 }
133         }
134         return (-1);
135 }
136
137 struct sockaddr *
138 get_ifa(char *cp, int n)
139 {
140         struct sockaddr *sa;
141         int i;
142
143         if (n == 0)
144                 return (NULL);
145         for (i = 1; i; i <<= 1)
146                 if (i & n) {
147                         sa = (struct sockaddr *)cp;
148                         if (i == RTA_IFA)
149                                 return (sa);
150                         ADVANCE(cp, sa);
151                 }
152
153         return (NULL);
154 }
155 struct iaddr defaddr = { .len = 4 }; /* NULL is for silence warnings */
156
157 void
158 routehandler(void)
159 {
160         int linkstat;
161         char msg[2048];
162         struct rt_msghdr *rtm;
163         struct if_msghdr *ifm;
164         struct ifa_msghdr *ifam;
165         struct if_announcemsghdr *ifan;
166         struct client_lease *l;
167         time_t t = time(NULL);
168         struct sockaddr *sa;
169         struct iaddr a;
170         ssize_t n;
171         char *errmsg, buf[64];
172
173         do {
174                 n = read(routefd, &msg, sizeof(msg));
175         } while (n == -1 && errno == EINTR);
176
177         rtm = (struct rt_msghdr *)msg;
178         if (n < sizeof(rtm->rtm_msglen) || n < rtm->rtm_msglen ||
179             rtm->rtm_version != RTM_VERSION)
180                 return;
181
182         switch (rtm->rtm_type) {
183         case RTM_NEWADDR:
184                 ifam = (struct ifa_msghdr *)rtm;
185                 if (ifam->ifam_index != ifi->index)
186                         break;
187                 if (findproto((char *)(ifam + 1), ifam->ifam_addrs) != AF_INET)
188                         break;
189                 sa = get_ifa((char *)(ifam + 1), ifam->ifam_addrs);
190                 if (sa == NULL) {
191                         errmsg = "sa == NULL";
192                         goto die;
193                 }
194
195                 if ((a.len = sizeof(struct in_addr)) > sizeof(a.iabuf))
196                         error("king bula sez: len mismatch");
197                 memcpy(a.iabuf, &((struct sockaddr_in *)sa)->sin_addr, a.len);
198                 if (addr_eq(a, defaddr))
199                         break;
200
201                 /* state_panic() can try unexpired existing leases */
202                 if (client->active && addr_eq(a, client->active->address))
203                         break;
204                 for (l = client->leases; l != NULL; l = l->next)
205                         if (addr_eq(a, l->address))
206                                 break;
207
208                 if (l != NULL)
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");
265         script_go();
266         error("routehandler: %s", errmsg);
267 }
268
269 int
270 main(int argc, char *argv[])
271 {
272         int      ch, fd, quiet = 0, i = 0, pipe_fd[2];
273         struct passwd *pw;
274
275         /* Initially, log errors to stderr as well as to syslogd. */
276         openlog(getprogname(), LOG_PID | LOG_NDELAY, DHCPD_LOG_FACILITY);
277         setlogmask(LOG_UPTO(LOG_INFO));
278
279         while ((ch = getopt(argc, argv, "c:dl:qu")) != -1)
280                 switch (ch) {
281                 case 'c':
282                         path_dhclient_conf = optarg;
283                         break;
284                 case 'd':
285                         no_daemon = 1;
286                         break;
287                 case 'l':
288                         path_dhclient_db = optarg;
289                         break;
290                 case 'q':
291                         quiet = 1;
292                         break;
293                 case 'u':
294                         unknown_ok = 0;
295                         break;
296                 default:
297                         usage();
298                 }
299
300         argc -= optind;
301         argv += optind;
302
303         if (argc != 1)
304                 usage();
305
306         ifi = calloc(1, sizeof(*ifi));
307         if (ifi == NULL)
308                 error("ifi calloc");
309         client = calloc(1, sizeof(*client));
310         if (client == NULL)
311                 error("client calloc");
312         config = calloc(1, sizeof(*config));
313         if (config == NULL)
314                 error("config calloc");
315
316         get_ifname(ifi->name, argv[0]);
317         if (path_dhclient_db == NULL && asprintf(&path_dhclient_db, "%s.%s",
318             _PATH_DHCLIENT_DB, ifi->name) == -1)
319                 error("asprintf");
320
321         if (quiet)
322                 log_perror = 0;
323
324         tzset();
325         time(&cur_time);
326
327         memset(&sockaddr_broadcast, 0, sizeof(sockaddr_broadcast));
328         sockaddr_broadcast.sin_family = AF_INET;
329         sockaddr_broadcast.sin_port = htons(REMOTE_PORT);
330         sockaddr_broadcast.sin_addr.s_addr = INADDR_BROADCAST;
331         sockaddr_broadcast.sin_len = sizeof(sockaddr_broadcast);
332         inaddr_any.s_addr = INADDR_ANY;
333
334         read_client_conf();
335
336         if (interface_status(ifi->name) == 0) {
337                 interface_link_forceup(ifi->name);
338                 /* Give it up to 4 seconds of silent grace to find link */
339                 i = -4;
340         } else
341                 i = 0;
342
343         while (!(ifi->linkstat = interface_link_status(ifi->name))) {
344                 if (i == 0)
345                         fprintf(stderr, "%s: no link ...", ifi->name);
346                 else if (i > 0)
347                         fprintf(stderr, ".");
348                 fflush(stderr);
349                 if (++i > config->link_timeout) {
350                         fprintf(stderr, " sleeping\n");
351                         goto dispatch;
352                 }
353                 sleep(1);
354         }
355         if (i > 0)
356                 fprintf(stderr, " got link\n");
357
358  dispatch:
359         if ((nullfd = open(_PATH_DEVNULL, O_RDWR, 0)) == -1)
360                 error("cannot open %s: %m", _PATH_DEVNULL);
361
362         if ((pw = getpwnam("_dhcp")) == NULL)
363                 error("no such user: _dhcp");
364
365         if (pipe(pipe_fd) == -1)
366                 error("pipe");
367
368         fork_privchld(pipe_fd[0], pipe_fd[1]);
369
370         close(pipe_fd[0]);
371         privfd = pipe_fd[1];
372
373         if ((fd = open(path_dhclient_db, O_RDONLY|O_EXLOCK|O_CREAT, 0)) == -1)
374                 error("can't open and lock %s: %m", path_dhclient_db);
375         read_client_leases();
376         if ((leaseFile = fopen(path_dhclient_db, "w")) == NULL)
377                 error("can't open %s: %m", path_dhclient_db);
378         rewrite_client_leases();
379         close(fd);
380
381         if ((routefd = socket(PF_ROUTE, SOCK_RAW, 0)) == -1)
382                 error("socket(PF_ROUTE, SOCK_RAW): %m");
383
384         /* set up the interface */
385         discover_interface();
386
387         if (chroot(_PATH_VAREMPTY) == -1)
388                 error("chroot");
389         if (chdir("/") == -1)
390                 error("chdir(\"/\")");
391
392         if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1)
393                 error("setresgid");
394         if (setgroups(1, &pw->pw_gid) == -1)
395                 error("setgroups");
396         if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1)
397                 error("setresuid");
398
399         endpwent();
400
401         setproctitle("%s", ifi->name);
402
403         if (ifi->linkstat) {
404                 client->state = S_INIT;
405                 state_reboot();
406         } else
407                 go_daemon();
408
409         dispatch();
410
411         /* not reached */
412         return (0);
413 }
414
415 void
416 usage(void)
417 {
418         fprintf(stderr, "usage: %s [-dqu] [-c file] [-l file] interface\n",
419             getprogname());
420         exit(1);
421 }
422
423 /*
424  * Individual States:
425  *
426  * Each routine is called from the dhclient_state_machine() in one of
427  * these conditions:
428  * -> entering INIT state
429  * -> recvpacket_flag == 0: timeout in this state
430  * -> otherwise: received a packet in this state
431  *
432  * Return conditions as handled by dhclient_state_machine():
433  * Returns 1, sendpacket_flag = 1: send packet, reset timer.
434  * Returns 1, sendpacket_flag = 0: just reset the timer (wait for a milestone).
435  * Returns 0: finish the nap which was interrupted for no good reason.
436  *
437  * Several per-interface variables are used to keep track of the process:
438  *   active_lease: the lease that is being used on the interface
439  *                 (null pointer if not configured yet).
440  *   offered_leases: leases corresponding to DHCPOFFER messages that have
441  *                   been sent to us by DHCP servers.
442  *   acked_leases: leases corresponding to DHCPACK messages that have been
443  *                 sent to us by DHCP servers.
444  *   sendpacket: DHCP packet we're trying to send.
445  *   destination: IP address to send sendpacket to
446  * In addition, there are several relevant per-lease variables.
447  *   T1_expiry, T2_expiry, lease_expiry: lease milestones
448  * In the active lease, these control the process of renewing the lease;
449  * In leases on the acked_leases list, this simply determines when we
450  * can no longer legitimately use the lease.
451  */
452 void
453 state_reboot(void)
454 {
455         /* Cancel all timeouts, since a link state change gets us here
456            and can happen anytime. */
457         cancel_timeout(state_init);
458         cancel_timeout(state_selecting);
459         cancel_timeout(state_bound);
460         cancel_timeout(send_discover);
461         cancel_timeout(send_request);
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 = 0;
483
484         /* Send out the first DHCPREQUEST packet. */
485         send_request();
486 }
487
488 /*
489  * Called when a lease has completely expired and we've
490  * been unable to renew it.
491  */
492 void
493 state_init(void)
494 {
495         /* Make a DHCPDISCOVER packet, and set appropriate per-interface
496            flags. */
497         make_discover(client->active);
498         client->xid = client->packet.xid;
499         client->destination = iaddr_broadcast;
500         client->state = S_SELECTING;
501         client->first_sending = cur_time;
502         client->interval = 0;
503
504         /* Add an immediate timeout to cause the first DHCPDISCOVER packet
505            to go out. */
506         send_discover();
507 }
508
509 /*
510  * state_selecting is called when one or more DHCPOFFER packets
511  * have been received and a configurable period of time has passed.
512  */
513 void
514 state_selecting(void)
515 {
516         struct client_lease *lp, *next, *picked;
517
518         /* Cancel state_selecting and send_discover timeouts, since either
519            one could have got us here. */
520         cancel_timeout(state_selecting);
521         cancel_timeout(send_discover);
522
523         /* We have received one or more DHCPOFFER packets.   Currently,
524            the only criterion by which we judge leases is whether or
525            not we get a response when we arp for them. */
526         picked = NULL;
527         for (lp = client->offered_leases; lp; lp = next) {
528                 next = lp->next;
529
530                 if (!picked) {
531                         picked = lp;
532                 } else {
533                         make_decline(lp);
534                         send_decline();
535                         free_client_lease(lp);
536                 }
537         }
538         client->offered_leases = NULL;
539
540         /* If we just tossed all the leases we were offered, go back
541            to square one. */
542         if (!picked) {
543                 client->state = S_INIT;
544                 state_init();
545                 return;
546         }
547         picked->next = NULL;
548
549         /* If it was a BOOTREPLY, we can just take the address right now. */
550         if (!picked->options[DHO_DHCP_MESSAGE_TYPE].len) {
551                 client->new = picked;
552
553                 /* Make up some lease expiry times
554                    XXX these should be configurable. */
555                 client->new->expiry = cur_time + 12000;
556                 client->new->renewal += cur_time + 8000;
557                 client->new->rebind += cur_time + 10000;
558
559                 client->state = S_REQUESTING;
560
561                 /* Bind to the address we received. */
562                 bind_lease();
563                 return;
564         }
565
566         /* Go to the REQUESTING state. */
567         client->destination = iaddr_broadcast;
568         client->state = S_REQUESTING;
569         client->first_sending = cur_time;
570         client->interval = 0;
571
572         /* Make a DHCPREQUEST packet from the lease we picked. */
573         make_request(picked);
574         client->xid = client->packet.xid;
575
576         /* Toss the lease we picked - we'll get it back in a DHCPACK. */
577         free_client_lease(picked);
578
579         /* Add an immediate timeout to send the first DHCPREQUEST packet. */
580         send_request();
581 }
582
583 void
584 dhcpack(struct iaddr client_addr, struct option_data *options)
585 {
586         struct client_lease *lease;
587
588
589         if (client->state != S_REBOOTING &&
590             client->state != S_REQUESTING &&
591             client->state != S_RENEWING &&
592             client->state != S_REBINDING)
593                 return;
594
595
596         lease = packet_to_lease(options);
597         if (!lease) {
598                 note("packet_to_lease failed.");
599                 return;
600         }
601
602         client->new = lease;
603
604         /* Stop resending DHCPREQUEST. */
605         cancel_timeout(send_request);
606
607         /* Figure out the lease time. */
608         if (client->new->options[DHO_DHCP_LEASE_TIME].data)
609                 client->new->expiry =
610                     getULong(client->new->options[DHO_DHCP_LEASE_TIME].data);
611         else
612                 client->new->expiry = DEFAULT_LEASE_TIME;
613         /* A number that looks negative here is really just very large,
614            because the lease expiry offset is unsigned. */
615         if (client->new->expiry < 0)
616                 client->new->expiry = TIME_MAX;
617         /* XXX should be fixed by resetting the client state */
618         if (client->new->expiry < 60)
619                 client->new->expiry = 60;
620
621         /* Take the server-provided renewal time if there is one;
622            otherwise figure it out according to the spec. */
623         if (client->new->options[DHO_DHCP_RENEWAL_TIME].len)
624                 client->new->renewal =
625                     getULong(client->new->options[DHO_DHCP_RENEWAL_TIME].data);
626         else
627                 client->new->renewal = client->new->expiry / 2;
628
629         /* Same deal with the rebind time. */
630         if (client->new->options[DHO_DHCP_REBINDING_TIME].len)
631                 client->new->rebind =
632                     getULong(client->new->options[DHO_DHCP_REBINDING_TIME].data);
633         else
634                 client->new->rebind = client->new->renewal +
635                     client->new->renewal / 2 + client->new->renewal / 4;
636
637         client->new->expiry += cur_time;
638         /* Lease lengths can never be negative. */
639         if (client->new->expiry < cur_time)
640                 client->new->expiry = TIME_MAX;
641         client->new->renewal += cur_time;
642         if (client->new->renewal < cur_time)
643                 client->new->renewal = TIME_MAX;
644         client->new->rebind += cur_time;
645         if (client->new->rebind < cur_time)
646                 client->new->rebind = TIME_MAX;
647
648         bind_lease();
649 }
650
651 void
652 bind_lease(void)
653 {
654         /* Run the client script with the new parameters. */
655         script_init((client->state == S_REQUESTING ? "BOUND" :
656             (client->state == S_RENEWING ? "RENEW" :
657                 (client->state == S_REBOOTING ? "REBOOT" : "REBIND"))));
658         if (client->active && client->state != S_REBOOTING)
659                 script_write_params("old_", client->active);
660         script_write_params("new_", client->new);
661         script_go();
662
663         /* Replace the old active lease with the new one. */
664         if (client->active)
665                 free_client_lease(client->active);
666         client->active = client->new;
667         client->new = NULL;
668
669         /* Write out new leases file. */
670         rewrite_client_leases();
671
672         /* Set up a timeout to start the renewal process. */
673         add_timeout(client->active->renewal, state_bound);
674
675         note("bound to %s -- renewal in %ld seconds.",
676             piaddr(client->active->address),
677             client->active->renewal - cur_time);
678         client->state = S_BOUND;
679         reinitialize_interface();
680         go_daemon();
681 }
682
683 /*
684  * state_bound is called when we've successfully bound to a particular
685  * lease, but the renewal time on that lease has expired.   We are
686  * expected to unicast a DHCPREQUEST to the server that gave us our
687  * original lease.
688  */
689 void
690 state_bound(void)
691 {
692         /* T1 has expired. */
693         make_request(client->active);
694         client->xid = client->packet.xid;
695
696         if (client->active->options[DHO_DHCP_SERVER_IDENTIFIER].len == 4) {
697                 memcpy(client->destination.iabuf,
698                     client->active->options[DHO_DHCP_SERVER_IDENTIFIER].data,
699                     4);
700                 client->destination.len = 4;
701         } else
702                 client->destination = iaddr_broadcast;
703
704         client->first_sending = cur_time;
705         client->interval = 0;
706         client->state = S_RENEWING;
707
708         /* Send the first packet immediately. */
709         send_request();
710 }
711
712 void
713 dhcpoffer(struct iaddr client_addr, struct option_data *options)
714 {
715         struct client_lease *lease, *lp;
716         int i;
717         int stop_selecting;
718         char *name = options[DHO_DHCP_MESSAGE_TYPE].len ? "DHCPOFFER" :
719             "BOOTREPLY";
720
721
722         if (client->state != S_SELECTING)
723                 return;
724
725
726         /* If this lease doesn't supply the minimum required parameters,
727            blow it off. */
728         for (i = 0; config->required_options[i]; i++) {
729                 if (!options[config->required_options[i]].len) {
730                         note("%s isn't satisfactory.", name);
731                         return;
732                 }
733         }
734
735         /* If we've already seen this lease, don't record it again. */
736         for (lease = client->offered_leases;
737             lease; lease = lease->next) {
738                 if (lease->address.len == sizeof(client->packet.yiaddr) &&
739                     !memcmp(lease->address.iabuf,
740                     &client->packet.yiaddr, lease->address.len)) {
741 #ifdef DEBUG
742                         debug("%s already seen.", name);
743 #endif
744                         return;
745                 }
746         }
747
748         lease = packet_to_lease(options);
749         if (!lease) {
750                 note("packet_to_lease failed.");
751                 return;
752         }
753
754         /* If this lease was acquired through a BOOTREPLY, record that
755            fact. */
756         if (!options[DHO_DHCP_MESSAGE_TYPE].len)
757                 lease->is_bootp = 1;
758
759         /* Figure out when we're supposed to stop selecting. */
760         stop_selecting = client->first_sending + config->select_interval;
761
762         /* If this is the lease we asked for, put it at the head of the
763            list, and don't mess with the arp request timeout. */
764         if (addr_eq(lease->address, client->requested_address)) {
765                 lease->next = client->offered_leases;
766                 client->offered_leases = lease;
767         } else {
768                 /* Put the lease at the end of the list. */
769                 lease->next = NULL;
770                 if (!client->offered_leases)
771                         client->offered_leases = lease;
772                 else {
773                         for (lp = client->offered_leases; lp->next;
774                             lp = lp->next)
775                                 ;       /* nothing */
776                         lp->next = lease;
777                 }
778         }
779
780         /* If the selecting interval has expired, go immediately to
781            state_selecting().  Otherwise, time out into
782            state_selecting at the select interval. */
783         if (stop_selecting <= cur_time)
784                 state_selecting();
785         else {
786                 add_timeout(stop_selecting, state_selecting);
787                 cancel_timeout(send_discover);
788         }
789 }
790
791 /*
792  * Allocate a client_lease structure and initialize it from the
793  * parameters in the specified packet.
794  */
795 struct client_lease *
796 packet_to_lease(struct option_data *options)
797 {
798         struct client_lease *lease;
799         int i;
800
801         lease = malloc(sizeof(struct client_lease));
802
803         if (!lease) {
804                 warning("dhcpoffer: no memory to record lease.");
805                 return (NULL);
806         }
807
808         memset(lease, 0, sizeof(*lease));
809
810         /* Copy the lease options. */
811         for (i = 0; i < 256; i++) {
812                 if (options[i].len) {
813                         lease->options[i] = options[i];
814                         options[i].data = NULL;
815                         options[i].len = 0;
816                         if (!check_option(lease, i)) {
817                                 warning("Invalid lease option - ignoring offer");
818                                 free_client_lease(lease);
819                                 return (NULL);
820                         }
821                 }
822         }
823
824         lease->address.len = sizeof(client->packet.yiaddr);
825         memcpy(lease->address.iabuf, &client->packet.yiaddr,
826             lease->address.len);
827
828         /* If the server name was filled out, copy it. */
829         if ((!lease->options[DHO_DHCP_OPTION_OVERLOAD].len ||
830             !(lease->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 2)) &&
831             client->packet.sname[0]) {
832                 lease->server_name = malloc(DHCP_SNAME_LEN + 1);
833                 if (!lease->server_name) {
834                         warning("dhcpoffer: no memory for server name.");
835                         free_client_lease(lease);
836                         return (NULL);
837                 }
838                 memcpy(lease->server_name, client->packet.sname,
839                     DHCP_SNAME_LEN);
840                 lease->server_name[DHCP_SNAME_LEN] = '\0';
841                 if (!res_hnok(lease->server_name)) {
842                         warning("Bogus server name %s", lease->server_name);
843                         free(lease->server_name);
844                         lease->server_name = NULL;
845                 }
846         }
847
848         /* Ditto for the filename. */
849         if ((!lease->options[DHO_DHCP_OPTION_OVERLOAD].len ||
850             !(lease->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 1)) &&
851             client->packet.file[0]) {
852                 /* Don't count on the NUL terminator. */
853                 lease->filename = malloc(DHCP_FILE_LEN + 1);
854                 if (!lease->filename) {
855                         warning("dhcpoffer: no memory for filename.");
856                         free_client_lease(lease);
857                         return (NULL);
858                 }
859                 memcpy(lease->filename, client->packet.file, DHCP_FILE_LEN);
860                 lease->filename[DHCP_FILE_LEN] = '\0';
861         }
862         return lease;
863 }
864
865 void
866 dhcpnak(struct iaddr client_addr, struct option_data *options)
867 {
868
869         if (client->state != S_REBOOTING &&
870             client->state != S_REQUESTING &&
871             client->state != S_RENEWING &&
872             client->state != S_REBINDING)
873                 return;
874
875
876         if (!client->active) {
877                 note("DHCPNAK with no active lease.");
878                 return;
879         }
880
881         free_client_lease(client->active);
882         client->active = NULL;
883
884         /* Stop sending DHCPREQUEST packets... */
885         cancel_timeout(send_request);
886
887         client->state = S_INIT;
888         state_init();
889 }
890
891 /*
892  * Send out a DHCPDISCOVER packet, and set a timeout to send out another
893  * one after the right interval has expired.  If we don't get an offer by
894  * the time we reach the panic interval, call the panic function.
895  */
896 void
897 send_discover(void)
898 {
899         int interval, increase = 1;
900
901         /* Figure out how long it's been since we started transmitting. */
902         interval = cur_time - client->first_sending;
903
904         /* If we're past the panic timeout, call the script and tell it
905            we haven't found anything for this interface yet. */
906         if (interval > config->timeout) {
907                 state_panic();
908                 return;
909         }
910
911         /*
912          * If we're supposed to increase the interval, do so.  If it's
913          * currently zero (i.e., we haven't sent any packets yet), set
914          * it to initial_interval; otherwise, add to it a random
915          * number between zero and two times itself.  On average, this
916          * means that it will double with every transmission.
917          */
918         if (increase) {
919                 if (!client->interval)
920                         client->interval = config->initial_interval;
921                 else {
922                         client->interval += (arc4random() >> 2) %
923                             (2 * client->interval);
924                 }
925
926                 /* Don't backoff past cutoff. */
927                 if (client->interval > config->backoff_cutoff)
928                         client->interval = ((config->backoff_cutoff / 2)
929                                  + ((arc4random() >> 2) %
930                                     config->backoff_cutoff));
931         } else if (!client->interval)
932                 client->interval = config->initial_interval;
933
934         /* If the backoff would take us to the panic timeout, just use that
935            as the interval. */
936         if (cur_time + client->interval >
937             client->first_sending + config->timeout)
938                 client->interval = (client->first_sending +
939                          config->timeout) - cur_time + 1;
940
941         /* Record the number of seconds since we started sending. */
942         if (interval < 65536)
943                 client->packet.secs = htons(interval);
944         else
945                 client->packet.secs = htons(65535);
946         client->secs = client->packet.secs;
947
948         note("DHCPDISCOVER on %s to %s port %d interval %ld",
949             ifi->name, inet_ntoa(sockaddr_broadcast.sin_addr),
950             ntohs(sockaddr_broadcast.sin_port), client->interval);
951
952         /* Send out a packet. */
953         send_packet(inaddr_any, &sockaddr_broadcast, NULL);
954
955         add_timeout(cur_time + client->interval, send_discover);
956 }
957
958 /*
959  * state_panic gets called if we haven't received any offers in a preset
960  * amount of time.   When this happens, we try to use existing leases
961  * that haven't yet expired, and failing that, we call the client script
962  * and hope it can do something.
963  */
964 void
965 state_panic(void)
966 {
967         struct client_lease *loop = client->active;
968         struct client_lease *lp;
969
970         note("No DHCPOFFERS received.");
971
972         /* We may not have an active lease, but we may have some
973            predefined leases that we can try. */
974         if (!client->active && client->leases)
975                 goto activate_next;
976
977         /* Run through the list of leases and see if one can be used. */
978         while (client->active) {
979                 if (client->active->expiry > cur_time) {
980                         note("Trying recorded lease %s",
981                             piaddr(client->active->address));
982                         /* Run the client script with the existing
983                            parameters. */
984                         script_init("TIMEOUT");
985                         script_write_params("new_", client->active);
986
987                         /* If the old lease is still good and doesn't
988                            yet need renewal, go into BOUND state and
989                            timeout at the renewal time. */
990                         if (!script_go()) {
991                                 if (cur_time <
992                                     client->active->renewal) {
993                                         client->state = S_BOUND;
994                                         note("bound: renewal in %ld seconds.",
995                                             client->active->renewal -
996                                             cur_time);
997                                         add_timeout(client->active->renewal,
998                                             state_bound);
999                                 } else {
1000                                         client->state = S_BOUND;
1001                                         note("bound: immediate renewal.");
1002                                         state_bound();
1003                                 }
1004                                 reinitialize_interface();
1005                                 go_daemon();
1006                                 return;
1007                         }
1008                 }
1009
1010                 /* If there are no other leases, give up. */
1011                 if (!client->leases) {
1012                         client->leases = client->active;
1013                         client->active = NULL;
1014                         break;
1015                 }
1016
1017 activate_next:
1018                 /* Otherwise, put the active lease at the end of the
1019                    lease list, and try another lease.. */
1020                 for (lp = client->leases; lp->next; lp = lp->next)
1021                         ;
1022                 lp->next = client->active;
1023                 if (lp->next)
1024                         lp->next->next = NULL;
1025                 client->active = client->leases;
1026                 client->leases = client->leases->next;
1027
1028                 /* If we already tried this lease, we've exhausted the
1029                    set of leases, so we might as well give up for
1030                    now. */
1031                 if (client->active == loop)
1032                         break;
1033                 else if (!loop)
1034                         loop = client->active;
1035         }
1036
1037         /* No leases were available, or what was available didn't work, so
1038            tell the shell script that we failed to allocate an address,
1039            and try again later. */
1040         note("No working leases in persistent database - sleeping.");
1041         script_init("FAIL");
1042         script_go();
1043         client->state = S_INIT;
1044         add_timeout(cur_time + config->retry_interval, state_init);
1045         go_daemon();
1046 }
1047
1048 void
1049 send_request(void)
1050 {
1051         struct sockaddr_in destination;
1052         struct in_addr from;
1053         int interval;
1054
1055         /* Figure out how long it's been since we started transmitting. */
1056         interval = cur_time - client->first_sending;
1057
1058         /* If we're in the INIT-REBOOT or REQUESTING state and we're
1059            past the reboot timeout, go to INIT and see if we can
1060            DISCOVER an address... */
1061         /* XXX In the INIT-REBOOT state, if we don't get an ACK, it
1062            means either that we're on a network with no DHCP server,
1063            or that our server is down.  In the latter case, assuming
1064            that there is a backup DHCP server, DHCPDISCOVER will get
1065            us a new address, but we could also have successfully
1066            reused our old address.  In the former case, we're hosed
1067            anyway.  This is not a win-prone situation. */
1068         if ((client->state == S_REBOOTING ||
1069             client->state == S_REQUESTING) &&
1070             interval > config->reboot_timeout) {
1071                 client->state = S_INIT;
1072                 cancel_timeout(send_request);
1073                 state_init();
1074                 return;
1075         }
1076
1077         /* If the lease has expired, relinquish the address and go back
1078            to the INIT state. */
1079         if (client->state != S_REQUESTING &&
1080             cur_time > client->active->expiry) {
1081                 /* Run the client script with the new parameters. */
1082                 script_init("EXPIRE");
1083                 script_write_params("old_", client->active);
1084                 script_go();
1085
1086                 client->state = S_INIT;
1087                 state_init();
1088                 return;
1089         }
1090
1091         /* Do the exponential backoff... */
1092         if (!client->interval)
1093                 client->interval = config->initial_interval;
1094         else
1095                 client->interval += ((arc4random() >> 2) %
1096                     (2 * client->interval));
1097
1098         /* Don't backoff past cutoff. */
1099         if (client->interval > config->backoff_cutoff)
1100                 client->interval = ((config->backoff_cutoff / 2) +
1101                     ((arc4random() >> 2) % client->interval));
1102
1103         /* If the backoff would take us to the expiry time, just set the
1104            timeout to the expiry time. */
1105         if (client->state != S_REQUESTING && cur_time + client->interval >
1106             client->active->expiry)
1107                 client->interval = client->active->expiry - cur_time + 1;
1108
1109         /* If the lease T2 time has elapsed, or if we're not yet bound,
1110            broadcast the DHCPREQUEST rather than unicasting. */
1111         memset(&destination, 0, sizeof(destination));
1112         if (client->state == S_REQUESTING ||
1113             client->state == S_REBOOTING ||
1114             cur_time > client->active->rebind)
1115                 destination.sin_addr.s_addr = INADDR_BROADCAST;
1116         else
1117                 memcpy(&destination.sin_addr.s_addr, client->destination.iabuf,
1118                     sizeof(destination.sin_addr.s_addr));
1119         destination.sin_port = htons(REMOTE_PORT);
1120         destination.sin_family = AF_INET;
1121         destination.sin_len = sizeof(destination);
1122
1123         if (client->state != S_REQUESTING)
1124                 memcpy(&from, client->active->address.iabuf, sizeof(from));
1125         else
1126                 from.s_addr = INADDR_ANY;
1127
1128         /* Record the number of seconds since we started sending. */
1129         if (client->state == S_REQUESTING)
1130                 client->packet.secs = client->secs;
1131         else {
1132                 if (interval < 65536)
1133                         client->packet.secs = htons(interval);
1134                 else
1135                         client->packet.secs = htons(65535);
1136         }
1137
1138         note("DHCPREQUEST on %s to %s port %d", ifi->name,
1139             inet_ntoa(destination.sin_addr), ntohs(destination.sin_port));
1140
1141         /* Send out a packet. */
1142         send_packet(from, &destination, NULL);
1143
1144         add_timeout(cur_time + client->interval, send_request);
1145 }
1146
1147 void
1148 send_decline(void)
1149 {
1150         note("DHCPDECLINE on %s to %s port %d", ifi->name,
1151             inet_ntoa(sockaddr_broadcast.sin_addr),
1152             ntohs(sockaddr_broadcast.sin_port));
1153
1154         /* Send out a packet. */
1155         send_packet(inaddr_any, &sockaddr_broadcast, NULL);
1156 }
1157
1158 void
1159 make_discover(struct client_lease *lease)
1160 {
1161         unsigned char discover = DHCPDISCOVER;
1162         struct option_data options[256];
1163         int i;
1164
1165         memset(options, 0, sizeof(options));
1166         memset(&client->packet, 0, sizeof(client->packet));
1167
1168         /* Set DHCP_MESSAGE_TYPE to DHCPDISCOVER */
1169         i = DHO_DHCP_MESSAGE_TYPE;
1170         options[i].data = &discover;
1171         options[i].len = sizeof(discover);
1172
1173         /* Request the options we want */
1174         i  = DHO_DHCP_PARAMETER_REQUEST_LIST;
1175         options[i].data = config->requested_options;
1176         options[i].len = config->requested_option_count;
1177
1178         /* If we had an address, try to get it again. */
1179         if (lease) {
1180                 client->requested_address = lease->address;
1181                 i = DHO_DHCP_REQUESTED_ADDRESS;
1182                 options[i].data = lease->address.iabuf;
1183                 options[i].len = lease->address.len;
1184         } else
1185                 client->requested_address.len = 0;
1186
1187         /* Send any options requested in the config file. */
1188         for (i = 0; i < 256; i++)
1189                 if (!options[i].data &&
1190                     config->send_options[i].data) {
1191                         options[i].data = config->send_options[i].data;
1192                         options[i].len = config->send_options[i].len;
1193                 }
1194
1195         /* Set up the option buffer to fit in a minimal UDP packet. */
1196         i = cons_options(options);
1197         if (i == -1 || client->packet.options[i] != DHO_END)
1198                 error("options do not fit in DHCPDISCOVER packet.");
1199         client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1200         if (client->packet_length < BOOTP_MIN_LEN)
1201                 client->packet_length = BOOTP_MIN_LEN;
1202
1203         client->packet.op = BOOTREQUEST;
1204         client->packet.htype = ifi->hw_address.htype;
1205         client->packet.hlen = ifi->hw_address.hlen;
1206         client->packet.hops = 0;
1207         client->packet.xid = arc4random();
1208         client->packet.secs = 0; /* filled in by send_discover. */
1209         client->packet.flags = 0;
1210
1211         memset(&client->packet.ciaddr, 0, sizeof(client->packet.ciaddr));
1212         memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1213         memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1214         memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1215         memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1216             ifi->hw_address.hlen);
1217 }
1218
1219 void
1220 make_request(struct client_lease * lease)
1221 {
1222         unsigned char request = DHCPREQUEST;
1223         struct option_data options[256];
1224         int i;
1225
1226         memset(options, 0, sizeof(options));
1227         memset(&client->packet, 0, sizeof(client->packet));
1228
1229         /* Set DHCP_MESSAGE_TYPE to DHCPREQUEST */
1230         i = DHO_DHCP_MESSAGE_TYPE;
1231         options[i].data = &request;
1232         options[i].len = sizeof(request);
1233
1234         /* Request the options we want */
1235         i = DHO_DHCP_PARAMETER_REQUEST_LIST;
1236         options[i].data = config->requested_options;
1237         options[i].len = config->requested_option_count;
1238
1239         /* If we are requesting an address that hasn't yet been assigned
1240            to us, use the DHCP Requested Address option. */
1241         if (client->state == S_REQUESTING) {
1242                 /* Send back the server identifier... */
1243                 i = DHO_DHCP_SERVER_IDENTIFIER;
1244                 options[i].data = lease->options[i].data;
1245                 options[i].len = lease->options[i].len;
1246         }
1247         if (client->state == S_REQUESTING ||
1248             client->state == S_REBOOTING) {
1249                 client->requested_address = lease->address;
1250                 i = DHO_DHCP_REQUESTED_ADDRESS;
1251                 options[i].data = lease->address.iabuf;
1252                 options[i].len = lease->address.len;
1253         } else
1254                 client->requested_address.len = 0;
1255
1256         /* Send any options requested in the config file. */
1257         for (i = 0; i < 256; i++)
1258                 if (!options[i].data && config->send_options[i].data) {
1259                         options[i].data = config->send_options[i].data;
1260                         options[i].len = config->send_options[i].len;
1261                 }
1262
1263         /* Set up the option buffer to fit in a minimal UDP packet. */
1264         i = cons_options(options);
1265         if (i == -1 || client->packet.options[i] != DHO_END)
1266                 error("options do not fit in DHCPREQUEST packet.");
1267         client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1268         if (client->packet_length < BOOTP_MIN_LEN)
1269                 client->packet_length = BOOTP_MIN_LEN;
1270
1271         client->packet.op = BOOTREQUEST;
1272         client->packet.htype = ifi->hw_address.htype;
1273         client->packet.hlen = ifi->hw_address.hlen;
1274         client->packet.hops = 0;
1275         client->packet.xid = client->xid;
1276         client->packet.secs = 0; /* Filled in by send_request. */
1277         client->packet.flags = 0;
1278
1279         /* If we own the address we're requesting, put it in ciaddr;
1280            otherwise set ciaddr to zero. */
1281         if (client->state == S_BOUND ||
1282             client->state == S_RENEWING ||
1283             client->state == S_REBINDING) {
1284                 memcpy(&client->packet.ciaddr,
1285                     lease->address.iabuf, lease->address.len);
1286         } else {
1287                 memset(&client->packet.ciaddr, 0,
1288                     sizeof(client->packet.ciaddr));
1289         }
1290
1291         memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1292         memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1293         memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1294         memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1295             ifi->hw_address.hlen);
1296 }
1297
1298 void
1299 make_decline(struct client_lease *lease)
1300 {
1301         struct option_data options[256];
1302         unsigned char decline = DHCPDECLINE;
1303         int i;
1304
1305         memset(options, 0, sizeof(options));
1306         memset(&client->packet, 0, sizeof(client->packet));
1307
1308         /* Set DHCP_MESSAGE_TYPE to DHCPDECLINE */
1309         i = DHO_DHCP_MESSAGE_TYPE;
1310         options[i].data = &decline;
1311         options[i].len = sizeof(decline);
1312
1313         /* Send back the server identifier... */
1314         i = DHO_DHCP_SERVER_IDENTIFIER;
1315         options[i].data = lease->options[i].data;
1316         options[i].len = lease->options[i].len;
1317
1318         /* Send back the address we're declining. */
1319         i = DHO_DHCP_REQUESTED_ADDRESS;
1320         options[i].data = lease->address.iabuf;
1321         options[i].len = lease->address.len;
1322
1323         /* Send the uid if the user supplied one. */
1324         i = DHO_DHCP_CLIENT_IDENTIFIER;
1325         if (config->send_options[i].len) {
1326                 options[i].data = config->send_options[i].data;
1327                 options[i].len = config->send_options[i].len;
1328         }
1329
1330         /* Set up the option buffer to fit in a minimal UDP packet. */
1331         i = cons_options(options);
1332         if (i == -1 || client->packet.options[i] != DHO_END)
1333                 error("options do not fit in DHCPDECLINE packet.");
1334         client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1335         if (client->packet_length < BOOTP_MIN_LEN)
1336                 client->packet_length = BOOTP_MIN_LEN;
1337
1338         client->packet.op = BOOTREQUEST;
1339         client->packet.htype = ifi->hw_address.htype;
1340         client->packet.hlen = ifi->hw_address.hlen;
1341         client->packet.hops = 0;
1342         client->packet.xid = client->xid;
1343         client->packet.secs = 0; /* Filled in by send_request. */
1344         client->packet.flags = 0;
1345
1346         /* ciaddr must always be zero. */
1347         memset(&client->packet.ciaddr, 0, sizeof(client->packet.ciaddr));
1348         memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1349         memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1350         memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1351         memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1352             ifi->hw_address.hlen);
1353 }
1354
1355 void
1356 free_client_lease(struct client_lease *lease)
1357 {
1358         int i;
1359
1360         if (lease->server_name)
1361                 free(lease->server_name);
1362         if (lease->filename)
1363                 free(lease->filename);
1364         for (i = 0; i < 256; i++) {
1365                 if (lease->options[i].len)
1366                         free(lease->options[i].data);
1367         }
1368         free(lease);
1369 }
1370
1371 void
1372 rewrite_client_leases(void)
1373 {
1374         struct client_lease *lp;
1375
1376         if (!leaseFile) /* XXX */
1377                 error("lease file not open");
1378
1379         fflush(leaseFile);
1380         rewind(leaseFile);
1381
1382         for (lp = client->leases; lp; lp = lp->next) {
1383                 if (client->active && addr_eq(lp->address,
1384                         client->active->address))
1385                         continue;
1386                 write_client_lease(lp);
1387         }
1388
1389         if (client->active)
1390                 write_client_lease(client->active);
1391
1392         fflush(leaseFile);
1393         ftruncate(fileno(leaseFile), ftello(leaseFile));
1394         fsync(fileno(leaseFile));
1395 }
1396
1397 void
1398 write_client_lease(struct client_lease *lease)
1399 {
1400         struct tm *t;
1401         int i;
1402
1403         /* If the lease came from the config file, we don't need to stash
1404            a copy in the lease database. */
1405         if (lease->is_static)
1406                 return;
1407
1408         if (!leaseFile) /* XXX */
1409                 error("lease file not open");
1410
1411         fprintf(leaseFile, "lease {\n");
1412         if (lease->is_bootp)
1413                 fprintf(leaseFile, "  bootp;\n");
1414         fprintf(leaseFile, "  interface \"%s\";\n", ifi->name);
1415         fprintf(leaseFile, "  fixed-address %s;\n", piaddr(lease->address));
1416         if (lease->filename)
1417                 fprintf(leaseFile, "  filename \"%s\";\n", lease->filename);
1418         if (lease->server_name)
1419                 fprintf(leaseFile, "  server-name \"%s\";\n",
1420                     lease->server_name);
1421         for (i = 0; i < 256; i++)
1422                 if (lease->options[i].len)
1423                         fprintf(leaseFile, "  option %s %s;\n",
1424                             dhcp_options[i].name,
1425                             pretty_print_option(i, lease->options[i].data,
1426                             lease->options[i].len, 1, 1));
1427
1428         t = gmtime(&lease->renewal);
1429         fprintf(leaseFile, "  renew %d %d/%d/%d %02d:%02d:%02d;\n",
1430             t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1431             t->tm_hour, t->tm_min, t->tm_sec);
1432         t = gmtime(&lease->rebind);
1433         fprintf(leaseFile, "  rebind %d %d/%d/%d %02d:%02d:%02d;\n",
1434             t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1435             t->tm_hour, t->tm_min, t->tm_sec);
1436         t = gmtime(&lease->expiry);
1437         fprintf(leaseFile, "  expire %d %d/%d/%d %02d:%02d:%02d;\n",
1438             t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1439             t->tm_hour, t->tm_min, t->tm_sec);
1440         fprintf(leaseFile, "}\n");
1441         fflush(leaseFile);
1442 }
1443
1444 void
1445 script_init(char *reason)
1446 {
1447         size_t           len;
1448         struct imsg_hdr  hdr;
1449         struct buf      *buf;
1450
1451         hdr.code = IMSG_SCRIPT_INIT;
1452         hdr.len = sizeof(struct imsg_hdr) + sizeof(size_t) + strlen(reason);
1453         buf = buf_open(hdr.len);
1454
1455         buf_add(buf, &hdr, sizeof(hdr));
1456         len = strlen(reason);
1457         buf_add(buf, &len, sizeof(len));
1458         buf_add(buf, reason, len);
1459
1460         buf_close(privfd, buf);
1461 }
1462
1463 void
1464 priv_script_init(char *reason)
1465 {
1466         client->scriptEnvsize = 100;
1467         if (client->scriptEnv == NULL)
1468                 client->scriptEnv =
1469                     calloc(client->scriptEnvsize, sizeof(char *));
1470         if (client->scriptEnv == NULL)
1471                 error("script_init: no memory for environment");
1472
1473         client->scriptEnv[0] = strdup(CLIENT_PATH);
1474         if (client->scriptEnv[0] == NULL)
1475                 error("script_init: no memory for environment");
1476
1477         client->scriptEnv[1] = NULL;
1478
1479         script_set_env("", "interface", ifi->name);
1480
1481         script_set_env("", "reason", reason);
1482 }
1483
1484 void
1485 priv_script_write_params(char *prefix, struct client_lease *lease)
1486 {
1487         u_int8_t dbuf[1500];
1488         int i, len = 0;
1489         char tbuf[128];
1490
1491         script_set_env(prefix, "ip_address", piaddr(lease->address));
1492
1493         if (lease->options[DHO_SUBNET_MASK].len &&
1494             (lease->options[DHO_SUBNET_MASK].len <
1495             sizeof(lease->address.iabuf))) {
1496                 struct iaddr netmask, subnet, broadcast;
1497
1498                 memcpy(netmask.iabuf, lease->options[DHO_SUBNET_MASK].data,
1499                     lease->options[DHO_SUBNET_MASK].len);
1500                 netmask.len = lease->options[DHO_SUBNET_MASK].len;
1501
1502                 subnet = subnet_number(lease->address, netmask);
1503                 if (subnet.len) {
1504                         script_set_env(prefix, "network_number",
1505                             piaddr(subnet));
1506                         if (!lease->options[DHO_BROADCAST_ADDRESS].len) {
1507                                 broadcast = broadcast_addr(subnet, netmask);
1508                                 if (broadcast.len)
1509                                         script_set_env(prefix,
1510                                             "broadcast_address",
1511                                             piaddr(broadcast));
1512                         }
1513                 }
1514         }
1515
1516         if (lease->filename)
1517                 script_set_env(prefix, "filename", lease->filename);
1518         if (lease->server_name)
1519                 script_set_env(prefix, "server_name",
1520                     lease->server_name);
1521         for (i = 0; i < 256; i++) {
1522                 u_int8_t *dp = NULL;
1523
1524                 if (config->defaults[i].len) {
1525                         if (lease->options[i].len) {
1526                                 switch (config->default_actions[i]) {
1527                                 case ACTION_DEFAULT:
1528                                         dp = lease->options[i].data;
1529                                         len = lease->options[i].len;
1530                                         break;
1531                                 case ACTION_SUPERSEDE:
1532 supersede:
1533                                         dp = config->defaults[i].data;
1534                                         len = config->defaults[i].len;
1535                                         break;
1536                                 case ACTION_PREPEND:
1537                                         len = config->defaults[i].len +
1538                                             lease->options[i].len;
1539                                         if (len >= sizeof(dbuf)) {
1540                                                 warning("no space to %s %s",
1541                                                     "prepend option",
1542                                                     dhcp_options[i].name);
1543                                                 goto supersede;
1544                                         }
1545                                         dp = dbuf;
1546                                         memcpy(dp,
1547                                             config->defaults[i].data,
1548                                             config->defaults[i].len);
1549                                         memcpy(dp +
1550                                             config->defaults[i].len,
1551                                             lease->options[i].data,
1552                                             lease->options[i].len);
1553                                         dp[len] = '\0';
1554                                         break;
1555                                 case ACTION_APPEND:
1556                                         len = config->defaults[i].len +
1557                                             lease->options[i].len;
1558                                         if (len >= sizeof(dbuf)) {
1559                                                 warning("no space to %s %s",
1560                                                     "append option",
1561                                                     dhcp_options[i].name);
1562                                                 goto supersede;
1563                                         }
1564                                         dp = dbuf;
1565                                         memcpy(dp, lease->options[i].data,
1566                                             lease->options[i].len);
1567                                         memcpy(dp + lease->options[i].len,
1568                                             config->defaults[i].data,
1569                                             config->defaults[i].len);
1570                                         dp[len] = '\0';
1571                                 }
1572                         } else {
1573                                 dp = config->defaults[i].data;
1574                                 len = config->defaults[i].len;
1575                         }
1576                 } else if (lease->options[i].len) {
1577                         len = lease->options[i].len;
1578                         dp = lease->options[i].data;
1579                 } else {
1580                         len = 0;
1581                 }
1582                 if (len) {
1583                         char name[256];
1584
1585                         if (dhcp_option_ev_name(name, sizeof(name),
1586                             &dhcp_options[i]))
1587                                 script_set_env(prefix, name,
1588                                     pretty_print_option(i, dp, len, 0, 0));
1589                 }
1590         }
1591         snprintf(tbuf, sizeof(tbuf), "%d", (int)lease->expiry);
1592         script_set_env(prefix, "expiry", tbuf);
1593 }
1594
1595 void
1596 script_write_params(char *prefix, struct client_lease *lease)
1597 {
1598         size_t           fn_len = 0, sn_len = 0, pr_len = 0;
1599         struct imsg_hdr  hdr;
1600         struct buf      *buf;
1601         int              i;
1602
1603         if (lease->filename != NULL)
1604                 fn_len = strlen(lease->filename);
1605         if (lease->server_name != NULL)
1606                 sn_len = strlen(lease->server_name);
1607         if (prefix != NULL)
1608                 pr_len = strlen(prefix);
1609
1610         hdr.code = IMSG_SCRIPT_WRITE_PARAMS;
1611         hdr.len = sizeof(hdr) + sizeof(struct client_lease) +
1612             sizeof(size_t) + fn_len + sizeof(size_t) + sn_len +
1613             sizeof(size_t) + pr_len;
1614
1615         for (i = 0; i < 256; i++)
1616                 hdr.len += sizeof(int) + lease->options[i].len;
1617
1618         scripttime = time(NULL);
1619
1620         buf = buf_open(hdr.len);
1621
1622         buf_add(buf, &hdr, sizeof(hdr));
1623         buf_add(buf, lease, sizeof(struct client_lease));
1624         buf_add(buf, &fn_len, sizeof(fn_len));
1625         buf_add(buf, lease->filename, fn_len);
1626         buf_add(buf, &sn_len, sizeof(sn_len));
1627         buf_add(buf, lease->server_name, sn_len);
1628         buf_add(buf, &pr_len, sizeof(pr_len));
1629         buf_add(buf, prefix, pr_len);
1630
1631         for (i = 0; i < 256; i++) {
1632                 buf_add(buf, &lease->options[i].len,
1633                     sizeof(lease->options[i].len));
1634                 buf_add(buf, lease->options[i].data,
1635                     lease->options[i].len);
1636         }
1637
1638         buf_close(privfd, buf);
1639 }
1640
1641 int
1642 script_go(void)
1643 {
1644         struct imsg_hdr  hdr;
1645         struct buf      *buf;
1646         int              ret;
1647
1648         scripttime = time(NULL);
1649
1650         hdr.code = IMSG_SCRIPT_GO;
1651         hdr.len = sizeof(struct imsg_hdr);
1652
1653         buf = buf_open(hdr.len);
1654
1655         buf_add(buf, &hdr, sizeof(hdr));
1656         buf_close(privfd, buf);
1657
1658         bzero(&hdr, sizeof(hdr));
1659         buf_read(privfd, &hdr, sizeof(hdr));
1660         if (hdr.code != IMSG_SCRIPT_GO_RET)
1661                 error("unexpected msg type %u", hdr.code);
1662         if (hdr.len != sizeof(hdr) + sizeof(int))
1663                 error("received corrupted message");
1664         buf_read(privfd, &ret, sizeof(ret));
1665
1666         return (ret);
1667 }
1668
1669 int
1670 priv_script_go(void)
1671 {
1672         char *scriptName, *argv[2], **envp;
1673         int pid, wpid, wstatus;
1674
1675         scripttime = time(NULL);
1676
1677         scriptName = config->script_name;
1678         envp = client->scriptEnv;
1679
1680         argv[0] = scriptName;
1681         argv[1] = NULL;
1682
1683         pid = fork();
1684         if (pid < 0) {
1685                 error("fork: %m");
1686                 wstatus = 0;
1687         } else if (pid) {
1688                 do {
1689                         wpid = wait(&wstatus);
1690                 } while (wpid != pid && wpid > 0);
1691                 if (wpid < 0) {
1692                         error("wait: %m");
1693                         wstatus = 0;
1694                 }
1695         } else {
1696                 execve(scriptName, argv, envp);
1697                 error("execve (%s, ...): %m", scriptName);
1698         }
1699
1700         script_flush_env();
1701
1702         return (WEXITSTATUS(wstatus));
1703 }
1704
1705 void
1706 script_set_env(const char *prefix, const char *name, const char *value)
1707 {
1708         int i, j, namelen;
1709
1710         namelen = strlen(name);
1711
1712         for (i = 0; client->scriptEnv[i]; i++)
1713                 if (strncmp(client->scriptEnv[i], name, namelen) == 0 &&
1714                     client->scriptEnv[i][namelen] == '=')
1715                         break;
1716
1717         if (client->scriptEnv[i])
1718                 /* Reuse the slot. */
1719                 free(client->scriptEnv[i]);
1720         else {
1721                 /* New variable.  Expand if necessary. */
1722                 if (i >= client->scriptEnvsize - 1) {
1723                         char **newscriptEnv;
1724                         int newscriptEnvsize = client->scriptEnvsize + 50;
1725
1726                         newscriptEnv = realloc(client->scriptEnv,
1727                             newscriptEnvsize);
1728                         if (newscriptEnv == NULL) {
1729                                 free(client->scriptEnv);
1730                                 client->scriptEnv = NULL;
1731                                 client->scriptEnvsize = 0;
1732                                 error("script_set_env: no memory for variable");
1733                         }
1734                         client->scriptEnv = newscriptEnv;
1735                         client->scriptEnvsize = newscriptEnvsize;
1736                 }
1737                 /* need to set the NULL pointer at end of array beyond
1738                    the new slot. */
1739                 client->scriptEnv[i + 1] = NULL;
1740         }
1741         /* Allocate space and format the variable in the appropriate slot. */
1742         client->scriptEnv[i] = malloc(strlen(prefix) + strlen(name) + 1 +
1743             strlen(value) + 1);
1744         if (client->scriptEnv[i] == NULL)
1745                 error("script_set_env: no memory for variable assignment");
1746
1747         /* No `` or $() command substitution allowed in environment values! */
1748         for (j = 0; j < strlen(value); j++)
1749                 switch (value[j]) {
1750                 case '`':
1751                 case '$':
1752                         error("illegal character (%c) in value '%s'", value[j],
1753                             value);
1754                         /* not reached */
1755                 }
1756         snprintf(client->scriptEnv[i], strlen(prefix) + strlen(name) +
1757             1 + strlen(value) + 1, "%s%s=%s", prefix, name, value);
1758 }
1759
1760 void
1761 script_flush_env(void)
1762 {
1763         int i;
1764
1765         for (i = 0; client->scriptEnv[i]; i++) {
1766                 free(client->scriptEnv[i]);
1767                 client->scriptEnv[i] = NULL;
1768         }
1769         client->scriptEnvsize = 0;
1770 }
1771
1772 int
1773 dhcp_option_ev_name(char *buf, size_t buflen, const struct option *option)
1774 {
1775         size_t i;
1776
1777         for (i = 0; option->name[i]; i++) {
1778                 if (i + 1 == buflen)
1779                         return 0;
1780                 if (option->name[i] == '-')
1781                         buf[i] = '_';
1782                 else
1783                         buf[i] = option->name[i];
1784         }
1785
1786         buf[i] = 0;
1787         return 1;
1788 }
1789
1790 void
1791 go_daemon(void)
1792 {
1793         static int state = 0;
1794
1795         if (no_daemon || state)
1796                 return;
1797
1798         state = 1;
1799
1800         /* Stop logging to stderr... */
1801         log_perror = 0;
1802
1803         if (daemon(1, 0) == -1)
1804                 error("daemon");
1805
1806         /* we are chrooted, daemon(3) fails to open /dev/null */
1807         if (nullfd != -1) {
1808                 dup2(nullfd, STDIN_FILENO);
1809                 dup2(nullfd, STDOUT_FILENO);
1810                 dup2(nullfd, STDERR_FILENO);
1811                 close(nullfd);
1812                 nullfd = -1;
1813         }
1814 }
1815
1816 int
1817 check_option(struct client_lease *l, int option)
1818 {
1819         char *opbuf;
1820         char *sbuf;
1821
1822         /* we use this, since this is what gets passed to dhclient-script */
1823
1824         opbuf = pretty_print_option(option, l->options[option].data,
1825             l->options[option].len, 0, 0);
1826
1827         sbuf = option_as_string(option, l->options[option].data,
1828             l->options[option].len);
1829
1830         switch (option) {
1831         case DHO_SUBNET_MASK:
1832         case DHO_SWAP_SERVER:
1833         case DHO_BROADCAST_ADDRESS:
1834         case DHO_DHCP_SERVER_IDENTIFIER:
1835         case DHO_ROUTER_SOLICITATION_ADDRESS:
1836         case DHO_DHCP_REQUESTED_ADDRESS:
1837                 if (ipv4addrs(opbuf) == 0) {
1838                         warning("Invalid IP address in option %s: %s",
1839                             dhcp_options[option].name, opbuf);
1840                         return (0);
1841                 }
1842                 if (l->options[option].len != 4) { /* RFC 2132 */
1843                         warning("warning: Only 1 IP address allowed in "
1844                             "%s option; length %d, must be 4",
1845                             dhcp_options[option].name,
1846                             l->options[option].len);
1847                         l->options[option].len = 4;
1848                 }
1849                 return (1);
1850         case DHO_TIME_SERVERS:
1851         case DHO_NAME_SERVERS:
1852         case DHO_ROUTERS:
1853         case DHO_DOMAIN_NAME_SERVERS:
1854         case DHO_LOG_SERVERS:
1855         case DHO_COOKIE_SERVERS:
1856         case DHO_LPR_SERVERS:
1857         case DHO_IMPRESS_SERVERS:
1858         case DHO_RESOURCE_LOCATION_SERVERS:
1859         case DHO_NIS_SERVERS:
1860         case DHO_NTP_SERVERS:
1861         case DHO_NETBIOS_NAME_SERVERS:
1862         case DHO_NETBIOS_DD_SERVER:
1863         case DHO_FONT_SERVERS:
1864                 if (ipv4addrs(opbuf) == 0) {
1865                         warning("Invalid IP address in option %s: %s",
1866                             dhcp_options[option].name, opbuf);
1867                         return (0);
1868                 }
1869                 return (1);
1870         case DHO_HOST_NAME:
1871         case DHO_DOMAIN_NAME:
1872         case DHO_NIS_DOMAIN:
1873                 if (!res_hnok(sbuf)) {
1874                         warning("Bogus Host Name option %d: %s (%s)", option,
1875                             sbuf, opbuf);
1876                         l->options[option].len = 0;
1877                         free(l->options[option].data);
1878                 }
1879                 return (1);
1880         case DHO_PAD:
1881         case DHO_TIME_OFFSET:
1882         case DHO_BOOT_SIZE:
1883         case DHO_MERIT_DUMP:
1884         case DHO_ROOT_PATH:
1885         case DHO_EXTENSIONS_PATH:
1886         case DHO_IP_FORWARDING:
1887         case DHO_NON_LOCAL_SOURCE_ROUTING:
1888         case DHO_POLICY_FILTER:
1889         case DHO_MAX_DGRAM_REASSEMBLY:
1890         case DHO_DEFAULT_IP_TTL:
1891         case DHO_PATH_MTU_AGING_TIMEOUT:
1892         case DHO_PATH_MTU_PLATEAU_TABLE:
1893         case DHO_INTERFACE_MTU:
1894         case DHO_ALL_SUBNETS_LOCAL:
1895         case DHO_PERFORM_MASK_DISCOVERY:
1896         case DHO_MASK_SUPPLIER:
1897         case DHO_ROUTER_DISCOVERY:
1898         case DHO_STATIC_ROUTES:
1899         case DHO_TRAILER_ENCAPSULATION:
1900         case DHO_ARP_CACHE_TIMEOUT:
1901         case DHO_IEEE802_3_ENCAPSULATION:
1902         case DHO_DEFAULT_TCP_TTL:
1903         case DHO_TCP_KEEPALIVE_INTERVAL:
1904         case DHO_TCP_KEEPALIVE_GARBAGE:
1905         case DHO_VENDOR_ENCAPSULATED_OPTIONS:
1906         case DHO_NETBIOS_NODE_TYPE:
1907         case DHO_NETBIOS_SCOPE:
1908         case DHO_X_DISPLAY_MANAGER:
1909         case DHO_DHCP_LEASE_TIME:
1910         case DHO_DHCP_OPTION_OVERLOAD:
1911         case DHO_DHCP_MESSAGE_TYPE:
1912         case DHO_DHCP_PARAMETER_REQUEST_LIST:
1913         case DHO_DHCP_MESSAGE:
1914         case DHO_DHCP_MAX_MESSAGE_SIZE:
1915         case DHO_DHCP_RENEWAL_TIME:
1916         case DHO_DHCP_REBINDING_TIME:
1917         case DHO_DHCP_CLASS_IDENTIFIER:
1918         case DHO_DHCP_CLIENT_IDENTIFIER:
1919         case DHO_DHCP_USER_CLASS_ID:
1920         case DHO_TFTP_SERVER:
1921         case DHO_END:
1922                 return (1);
1923         default:
1924                 if (!unknown_ok)
1925                         warning("unknown dhcp option value 0x%x", option);
1926                 return (unknown_ok);
1927         }
1928 }
1929
1930 int
1931 res_hnok(const char *name)
1932 {
1933         const char *dn = name;
1934         int pch = '.', ch = *dn++;
1935         int warn = 0;
1936
1937         while (ch != '\0') {
1938                 int nch = *dn++;
1939
1940                 if (ch == '.') {
1941                         ;
1942                 } else if (pch == '.' || nch == '.' || nch == '\0') {
1943                         if (!isalnum(ch))
1944                                 return (0);
1945                 } else if (!isalnum(ch) && ch != '-' && ch != '_')
1946                                 return (0);
1947                 else if (ch == '_' && warn == 0) {
1948                         warning("warning: hostname %s contains an "
1949                             "underscore which violates RFC 952", name);
1950                         warn++;
1951                 }
1952                 pch = ch, ch = nch;
1953         }
1954         return (1);
1955 }
1956
1957 /* Does buf consist only of dotted decimal ipv4 addrs?
1958  * return how many if so,
1959  * otherwise, return 0
1960  */
1961 int
1962 ipv4addrs(char * buf)
1963 {
1964         struct in_addr jnk;
1965         int count = 0;
1966
1967         while (inet_aton(buf, &jnk) == 1){
1968                 count++;
1969                 while (*buf == '.' || isdigit(*buf))
1970                         buf++;
1971                 if (*buf == '\0')
1972                         return (count);
1973                 while (*buf ==  ' ')
1974                         buf++;
1975         }
1976         return (0);
1977 }
1978
1979 char *
1980 option_as_string(unsigned int code, unsigned char *data, int len)
1981 {
1982         static char optbuf[32768]; /* XXX */
1983         char *op = optbuf;
1984         int opleft = sizeof(optbuf);
1985         unsigned char *dp = data;
1986
1987         if (code > 255)
1988                 error("option_as_string: bad code %d", code);
1989
1990         for (; dp < data + len; dp++) {
1991                 if (!isascii(*dp) || !isprint(*dp)) {
1992                         if (dp + 1 != data + len || *dp != 0) {
1993                                 size_t oplen;
1994                                 snprintf(op, opleft, "\\%03o", *dp);
1995                                 oplen = strlen(op);
1996                                 op += oplen;
1997                                 opleft -= oplen;
1998                         }
1999                 } else if (*dp == '"' || *dp == '\'' || *dp == '$' ||
2000                     *dp == '`' || *dp == '\\') {
2001                         *op++ = '\\';
2002                         *op++ = *dp;
2003                         opleft -= 2;
2004                 } else {
2005                         *op++ = *dp;
2006                         opleft--;
2007                 }
2008         }
2009         if (opleft < 1)
2010                 goto toobig;
2011         *op = 0;
2012         return optbuf;
2013 toobig:
2014         warning("dhcp option too large");
2015         return "<error>";
2016 }
2017
2018 int
2019 fork_privchld(int fd, int fd2)
2020 {
2021         struct pollfd pfd[1];
2022         int nfds, pfail = 0;
2023
2024         switch (fork()) {
2025         case -1:
2026                 error("cannot fork");
2027                 break;
2028         case 0:
2029                 break;
2030         default:
2031                 return (0);
2032         }
2033
2034         if (chdir("/") == -1)
2035                 error("chdir(\"/\")");
2036
2037         setproctitle("%s [priv]", ifi->name);
2038
2039         dup2(nullfd, STDIN_FILENO);
2040         dup2(nullfd, STDOUT_FILENO);
2041         dup2(nullfd, STDERR_FILENO);
2042         close(nullfd);
2043         close(fd2);
2044
2045         for (;;) {
2046                 pfd[0].fd = fd;
2047                 pfd[0].events = POLLIN;
2048                 if ((nfds = poll(pfd, 1, INFTIM)) == -1)
2049                         if (errno != EINTR)
2050                                 error("poll error");
2051
2052                 /*
2053                  * Handle temporary errors, but bail if they persist.
2054                  */
2055                 if (nfds == 0 || !(pfd[0].revents & POLLIN)) {
2056                         if (pfail > POLL_FAILURES)
2057                                 error("poll failed > %d times", POLL_FAILURES);
2058                         sleep(pfail * POLL_FAILURE_WAIT);
2059                         pfail++;
2060                         continue;
2061                 }
2062
2063                 dispatch_imsg(fd);
2064         }
2065 }
2066
2067 void
2068 get_ifname(char *ifname, char *arg)
2069 {
2070         struct ifgroupreq ifgr;
2071         struct ifg_req *ifg;
2072         int s, len;
2073
2074         if (!strcmp(arg, "egress")) {
2075                 s = socket(AF_INET, SOCK_DGRAM, 0);
2076                 if (s == -1)
2077                         error("socket error");
2078                 bzero(&ifgr, sizeof(ifgr));
2079                 strlcpy(ifgr.ifgr_name, "egress", sizeof(ifgr.ifgr_name));
2080                 if (ioctl(s, SIOCGIFGMEMB, (caddr_t)&ifgr) == -1) {
2081                         if (errno == ENOENT)
2082                                 error("no interface in group egress found");
2083                         error("ioctl SIOCGIFGMEMB: %m");
2084                 }
2085                 len = ifgr.ifgr_len;
2086                 if ((ifgr.ifgr_groups = calloc(1, len)) == NULL)
2087                         error("get_ifname");
2088                 if (ioctl(s, SIOCGIFGMEMB, (caddr_t)&ifgr) == -1)
2089                         error("ioctl SIOCGIFGMEMB: %m");
2090
2091                 arg = NULL;
2092                 for (ifg = ifgr.ifgr_groups;
2093                      ifg && len >= sizeof(struct ifg_req); ifg++) {
2094                         len -= sizeof(struct ifg_req);
2095                         if (arg)
2096                                 error("too many interfaces in group egress");
2097                         arg = ifg->ifgrq_member;
2098                 }
2099
2100                 if (strlcpy(ifi->name, arg, IFNAMSIZ) >= IFNAMSIZ)
2101                         error("Interface name too long: %m");
2102
2103                 free(ifgr.ifgr_groups);
2104                 close(s);
2105         } else if (strlcpy(ifi->name, arg, IFNAMSIZ) >= IFNAMSIZ)
2106                 error("Interface name too long");
2107 }