1 /* $NetBSD: main.c,v 1.26 2019/02/03 03:19:31 mrg Exp $ */
2
3 /*
4 * The mrouted program is covered by the license in the accompanying file
5 * named "LICENSE". Use of the mrouted program represents acceptance of
6 * the terms and conditions listed in that file.
7 *
8 * The mrouted program is COPYRIGHT 1989 by The Board of Trustees of
9 * Leland Stanford Junior University.
10 */
11
12 /*
13 * Written by Steve Deering, Stanford University, February 1989.
14 *
15 * (An earlier version of DVMRP was implemented by David Waitzman of
16 * BBN STC by extending Berkeley's routed program. Some of Waitzman's
17 * extensions have been incorporated into mrouted, but none of the
18 * original routed code has been adopted.)
19 */
20
21
22 #include "defs.h"
23 #include <stdarg.h>
24 #include <fcntl.h>
25
26 #ifdef SNMP
27 #include "snmp.h"
28 #endif
29
30 #include <sys/cdefs.h>
31 #ifndef lint
32 __RCSID("@(#) $NetBSD: main.c,v 1.26 2019/02/03 03:19:31 mrg Exp $");
33 #endif
34
35 #include <ctype.h>
36 #include <err.h>
37 #include <util.h>
38
39 extern char *configfilename;
40 char versionstring[100];
41
42 static char dumpfilename[] = _PATH_MROUTED_DUMP;
43 static char cachefilename[] = _PATH_MROUTED_CACHE;
44 static char genidfilename[] = _PATH_MROUTED_GENID;
45
46 int cache_lifetime = DEFAULT_CACHE_LIFETIME;
47 int max_prune_lifetime = DEFAULT_CACHE_LIFETIME * 2;
48
49 int debug = 0;
50 u_char pruning = 1; /* Enable pruning by default */
51
52 #ifdef SNMP
53 #define NHANDLERS 34
54 #else
55 #define NHANDLERS 2
56 #endif
57
58 static struct ihandler {
59 int fd; /* File descriptor */
60 ihfunc_t func; /* Function to call with &fd_set */
61 } ihandlers[NHANDLERS];
62 static int nhandlers = 0;
63
64 /*
65 * Forward declarations.
66 */
67 static void fasttimer(int);
68 __dead static void done(int);
69 static void dump(int);
70 static void fdump(int);
71 static void cdump(int);
72 static void restart(int);
73 static void timer(void);
74 static void cleanup(void);
75 static void resetlogging(void *);
76
77 /* To shut up gcc -Wstrict-prototypes */
78 int main(int argc, char *argv[]);
79 void logit(int severity, int syserr, const char *format, ...)
80 __attribute__((__format__(__printf__, 3, 4)));
81
82 int
register_input_handler(int fd,ihfunc_t func)83 register_input_handler(int fd, ihfunc_t func)
84 {
85 if (nhandlers >= NHANDLERS)
86 return -1;
87
88 ihandlers[nhandlers].fd = fd;
89 ihandlers[nhandlers++].func = func;
90
91 return 0;
92 }
93
94 int
main(int argc,char * argv[])95 main(int argc, char *argv[])
96 {
97 int recvlen;
98 int omask;
99 socklen_t dummy;
100 FILE *fp;
101 struct timeval tv;
102 u_int32_t prev_genid;
103 int vers;
104 fd_set rfds, readers;
105 int nfds, n, i;
106 #ifdef SNMP
107 struct timeval timeout, *tvp = &timeout;
108 struct timeval sched, *svp = &sched, now, *nvp = &now;
109 int index, block;
110 #endif
111
112 setlinebuf(stderr);
113
114 if (geteuid() != 0) {
115 fprintf(stderr, "must be root\n");
116 exit(1);
117 }
118
119 argv++, argc--;
120 while (argc > 0 && *argv[0] == '-') {
121 if (strcmp(*argv, "-d") == 0) {
122 if (argc > 1 && isdigit((unsigned char)*(argv + 1)[0])) {
123 argv++, argc--;
124 debug = atoi(*argv);
125 } else
126 debug = DEFAULT_DEBUG;
127 } else if (strcmp(*argv, "-c") == 0) {
128 if (argc > 1) {
129 argv++, argc--;
130 configfilename = *argv;
131 } else
132 goto usage;
133 } else if (strcmp(*argv, "-p") == 0) {
134 pruning = 0;
135 #ifdef SNMP
136 } else if (strcmp(*argv, "-P") == 0) {
137 if (argc > 1 && isdigit(*(argv + 1)[0])) {
138 argv++, argc--;
139 dest_port = atoi(*argv);
140 } else
141 dest_port = DEFAULT_PORT;
142 #endif
143 } else
144 goto usage;
145 argv++, argc--;
146 }
147
148 if (argc > 0) {
149 usage: fprintf(stderr,
150 "usage: mrouted [-p] [-c configfile] [-d [debug_level]]\n");
151 exit(1);
152 }
153
154 if (debug == 0) {
155 /*
156 * Detach from the terminal
157 */
158 if (daemon(0, 0))
159 err(1, "can't fork");
160 pidfile(NULL);
161 }
162 else
163 fprintf(stderr, "debug level %u\n", debug);
164
165 #ifdef LOG_DAEMON
166 (void)openlog("mrouted", LOG_PID, LOG_DAEMON);
167 (void)setlogmask(LOG_UPTO(LOG_NOTICE));
168 #else
169 (void)openlog("mrouted", LOG_PID);
170 #endif
171 snprintf(versionstring, sizeof(versionstring),
172 "mrouted version %d.%d", PROTOCOL_VERSION, MROUTED_VERSION);
173
174 logit(LOG_NOTICE, 0, "%s", versionstring);
175
176 /*
177 * Get generation id
178 */
179 gettimeofday(&tv, 0);
180 dvmrp_genid = tv.tv_sec;
181
182 fp = fopen(genidfilename, "r");
183 if (fp != NULL) {
184 fscanf(fp, "%d", &prev_genid);
185 if (prev_genid == dvmrp_genid)
186 dvmrp_genid++;
187 (void) fclose(fp);
188 }
189
190 fp = fopen(genidfilename, "w");
191 if (fp != NULL) {
192 fprintf(fp, "%d", dvmrp_genid);
193 (void) fclose(fp);
194 }
195
196 callout_init();
197 init_igmp();
198 init_routes();
199 init_ktable();
200 k_init_dvmrp(); /* enable DVMRP routing in kernel */
201
202 #ifndef OLD_KERNEL
203 vers = k_get_version();
204 /*XXX
205 * This function must change whenever the kernel version changes
206 */
207 if ((((vers >> 8) & 0xff) != 3) ||
208 ((vers & 0xff) != 5))
209 logit(LOG_ERR, 0, "kernel (v%d.%d)/mrouted (v%d.%d) version mismatch",
210 (vers >> 8) & 0xff, vers & 0xff,
211 PROTOCOL_VERSION, MROUTED_VERSION);
212 #endif
213
214 #ifdef SNMP
215 if (i = snmp_init())
216 return i;
217
218 gettimeofday(nvp, 0);
219 if (nvp->tv_usec < 500000L){
220 svp->tv_usec = nvp->tv_usec + 500000L;
221 svp->tv_sec = nvp->tv_sec;
222 } else {
223 svp->tv_usec = nvp->tv_usec - 500000L;
224 svp->tv_sec = nvp->tv_sec + 1;
225 }
226 #endif /* SNMP */
227
228 init_vifs();
229
230 #ifdef RSRR
231 rsrr_init();
232 #endif /* RSRR */
233
234 /*
235 * Allow cleanup if unexpected exit. Apparently some architectures
236 * have a kernel bug where closing the socket doesn't do an
237 * ip_mrouter_done(), so we attempt to do it on exit.
238 */
239 atexit(cleanup);
240
241 if (debug)
242 fprintf(stderr, "pruning %s\n", pruning ? "on" : "off");
243
244 (void)signal(SIGALRM, fasttimer);
245
246 (void)signal(SIGHUP, restart);
247 (void)signal(SIGTERM, done);
248 (void)signal(SIGINT, done);
249 (void)signal(SIGUSR1, fdump);
250 (void)signal(SIGUSR2, cdump);
251 if (debug != 0)
252 (void)signal(SIGQUIT, dump);
253
254 FD_ZERO(&readers);
255 if (igmp_socket >= FD_SETSIZE)
256 logit(LOG_ERR, 0, "descriptor too big");
257 FD_SET(igmp_socket, &readers);
258 nfds = igmp_socket + 1;
259 for (i = 0; i < nhandlers; i++) {
260 if (ihandlers[i].fd >= FD_SETSIZE)
261 logit(LOG_ERR, 0, "descriptor too big");
262 FD_SET(ihandlers[i].fd, &readers);
263 if (ihandlers[i].fd >= nfds)
264 nfds = ihandlers[i].fd + 1;
265 }
266
267 /*
268 * Install the vifs in the kernel as late as possible in the
269 * initialization sequence.
270 */
271 init_installvifs();
272
273 if (debug >= 2) dump(0);
274
275 /* Start up the log rate-limiter */
276 resetlogging(NULL);
277
278 (void)alarm(1); /* schedule first timer interrupt */
279
280 /*
281 * Main receive loop.
282 */
283 for(;;) {
284 #ifdef SYSV
285 sigset_t block, oblock;
286 #endif
287 bcopy((char *)&readers, (char *)&rfds, sizeof(rfds));
288 #ifdef SNMP
289 gettimeofday(nvp, 0);
290 if (nvp->tv_sec > svp->tv_sec
291 || (nvp->tv_sec == svp->tv_sec && nvp->tv_usec > svp->tv_usec)){
292 alarmTimer(nvp);
293 eventTimer(nvp);
294 if (nvp->tv_usec < 500000L){
295 svp->tv_usec = nvp->tv_usec + 500000L;
296 svp->tv_sec = nvp->tv_sec;
297 } else {
298 svp->tv_usec = nvp->tv_usec - 500000L;
299 svp->tv_sec = nvp->tv_sec + 1;
300 }
301 }
302
303 tvp = &timeout;
304 tvp->tv_sec = 0;
305 tvp->tv_usec = 500000L;
306
307 block = 0;
308 snmp_select_info(&nfds, &rfds, tvp, &block);
309 if (block == 1)
310 tvp = NULL; /* block without timeout */
311 if ((n = select(nfds, &rfds, NULL, NULL, tvp)) < 0)
312 #else
313 if ((n = select(nfds, &rfds, NULL, NULL, NULL)) < 0)
314 #endif
315 {
316 if (errno != EINTR) /* SIGALRM is expected */
317 logit(LOG_WARNING, errno, "select failed");
318 continue;
319 }
320
321 if (FD_ISSET(igmp_socket, &rfds)) {
322 recvlen = recvfrom(igmp_socket, recv_buf, RECV_BUF_SIZE,
323 0, NULL, &dummy);
324 if (recvlen < 0) {
325 if (errno != EINTR) logit(LOG_ERR, errno, "recvfrom");
326 continue;
327 }
328 #ifdef SYSV
329 (void)sigemptyset(&block);
330 (void)sigaddset(&block, SIGALRM);
331 if (sigprocmask(SIG_BLOCK, &block, &oblock) < 0)
332 logit(LOG_ERR, errno, "sigprocmask");
333 #else
334 omask = sigblock(sigmask(SIGALRM));
335 #endif
336 accept_igmp(recvlen);
337 #ifdef SYSV
338 (void)sigprocmask(SIG_SETMASK, &oblock, NULL);
339 #else
340 (void)sigsetmask(omask);
341 #endif
342 }
343
344 for (i = 0; i < nhandlers; i++) {
345 if (FD_ISSET(ihandlers[i].fd, &rfds)) {
346 (*ihandlers[i].func)(ihandlers[i].fd, &rfds);
347 }
348 }
349
350 #ifdef SNMP
351 snmp_read(&rfds);
352 snmp_timeout(); /* poll */
353 #endif
354 }
355 }
356
357
358 /*
359 * routine invoked every second. Its main goal is to cycle through
360 * the routing table and send partial updates to all neighbors at a
361 * rate that will cause the entire table to be sent in ROUTE_REPORT_INTERVAL
362 * seconds. Also, every TIMER_INTERVAL seconds it calls timer() to
363 * do all the other time-based processing.
364 */
365 static void
fasttimer(int i)366 fasttimer(int i)
367 {
368 static unsigned int tlast;
369 static unsigned int nsent;
370 unsigned int t = tlast + 1;
371 int n;
372
373 /*
374 * if we're in the last second, send everything that's left.
375 * otherwise send at least the fraction we should have sent by now.
376 */
377 if (t >= ROUTE_REPORT_INTERVAL) {
378 int nleft = nroutes - nsent;
379 while (nleft > 0) {
380 if ((n = report_next_chunk()) <= 0)
381 break;
382 nleft -= n;
383 }
384 tlast = 0;
385 nsent = 0;
386 } else {
387 unsigned int ncum = nroutes * t / ROUTE_REPORT_INTERVAL;
388 while (nsent < ncum) {
389 if ((n = report_next_chunk()) <= 0)
390 break;
391 nsent += n;
392 }
393 tlast = t;
394 }
395 if ((t % TIMER_INTERVAL) == 0)
396 timer();
397
398 age_callout_queue();/* Advance the timer for the callout queue
399 for groups */
400 alarm(1);
401 }
402
403 /*
404 * The 'virtual_time' variable is initialized to a value that will cause the
405 * first invocation of timer() to send a probe or route report to all vifs
406 * and send group membership queries to all subnets for which this router is
407 * querier. This first invocation occurs approximately TIMER_INTERVAL seconds
408 * after the router starts up. Note that probes for neighbors and queries
409 * for group memberships are also sent at start-up time, as part of initial-
410 * ization. This repetition after a short interval is desirable for quickly
411 * building up topology and membership information in the presence of possible
412 * packet loss.
413 *
414 * 'virtual_time' advances at a rate that is only a crude approximation of
415 * real time, because it does not take into account any time spent processing,
416 * and because the timer intervals are sometimes shrunk by a random amount to
417 * avoid unwanted synchronization with other routers.
418 */
419
420 static u_long virtual_time = 0;
421
422
423 /*
424 * Timer routine. Performs periodic neighbor probing, route reporting, and
425 * group querying duties, and drives various timers in routing entries and
426 * virtual interface data structures.
427 */
428 static void
timer(void)429 timer(void)
430 {
431 age_routes(); /* Advance the timers in the route entries */
432 age_vifs(); /* Advance the timers for neighbors */
433 age_table_entry(); /* Advance the timers for the cache entries */
434
435 if (virtual_time % GROUP_QUERY_INTERVAL == 0) {
436 /*
437 * Time to query the local group memberships on all subnets
438 * for which this router is the elected querier.
439 */
440 query_groups();
441 }
442
443 if (virtual_time % NEIGHBOR_PROBE_INTERVAL == 0) {
444 /*
445 * Time to send a probe on all vifs from which no neighbors have
446 * been heard. Also, check if any inoperative interfaces have now
447 * come up. (If they have, they will also be probed as part of
448 * their initialization.)
449 */
450 probe_for_neighbors();
451
452 if (vifs_down)
453 check_vif_state();
454 }
455
456 delay_change_reports = FALSE;
457 if (routes_changed) {
458 /*
459 * Some routes have changed since the last timer interrupt, but
460 * have not been reported yet. Report the changed routes to all
461 * neighbors.
462 */
463 report_to_all_neighbors(CHANGED_ROUTES);
464 }
465
466 #ifdef SNMP
467 sync_timer();
468 #endif
469
470 /*
471 * Advance virtual time
472 */
473 virtual_time += TIMER_INTERVAL;
474 }
475
476
477 /*
478 * On termination, let everyone know we're going away.
479 */
480 static void
done(int i)481 done(int i)
482 {
483 logit(LOG_NOTICE, 0, "%s exiting", versionstring);
484 cleanup();
485 _exit(1);
486 }
487
488 static void
cleanup(void)489 cleanup(void)
490 {
491 static int in_cleanup = 0;
492
493 if (!in_cleanup) {
494 in_cleanup++;
495 #ifdef RSRR
496 rsrr_clean();
497 #endif /* RSRR */
498 expire_all_routes();
499 report_to_all_neighbors(ALL_ROUTES);
500 k_stop_dvmrp();
501 }
502 }
503
504
505 /*
506 * Dump internal data structures to stderr.
507 */
508 static void
dump(int i)509 dump(int i)
510 {
511 dump_vifs(stderr);
512 dump_routes(stderr);
513 }
514
515
516 /*
517 * Dump internal data structures to a file.
518 */
519 static void
fdump(int i)520 fdump(int i)
521 {
522 FILE *fp;
523
524 fp = fopen(dumpfilename, "w");
525 if (fp != NULL) {
526 dump_vifs(fp);
527 dump_routes(fp);
528 (void) fclose(fp);
529 }
530 }
531
532
533 /*
534 * Dump local cache contents to a file.
535 */
536 static void
cdump(int i)537 cdump(int i)
538 {
539 FILE *fp;
540
541 fp = fopen(cachefilename, "w");
542 if (fp != NULL) {
543 dump_cache(fp);
544 (void) fclose(fp);
545 }
546 }
547
548
549 /*
550 * Restart mrouted
551 */
552 static void
restart(int i)553 restart(int i)
554 {
555 int omask;
556 #ifdef SYSV
557 sigset_t block, oblock;
558 #endif
559
560 logit(LOG_NOTICE, 0, "%s restart", versionstring);
561
562 /*
563 * reset all the entries
564 */
565 #ifdef SYSV
566 (void)sigemptyset(&block);
567 (void)sigaddset(&block, SIGALRM);
568 if (sigprocmask(SIG_BLOCK, &block, &oblock) < 0)
569 logit(LOG_ERR, errno, "sigprocmask");
570 #else
571 omask = sigblock(sigmask(SIGALRM));
572 #endif
573 free_all_prunes();
574 free_all_routes();
575 stop_all_vifs();
576 k_stop_dvmrp();
577 close(igmp_socket);
578 close(udp_socket);
579
580 /*
581 * start processing again
582 */
583 dvmrp_genid++;
584 pruning = 1;
585
586 init_igmp();
587 init_routes();
588 init_ktable();
589 init_vifs();
590 k_init_dvmrp(); /* enable DVMRP routing in kernel */
591 init_installvifs();
592
593 #ifdef SYSV
594 (void)sigprocmask(SIG_SETMASK, &oblock, NULL);
595 #else
596 (void)sigsetmask(omask);
597 #endif
598 }
599
600 #define LOG_MAX_MSGS 20 /* if > 20/minute then shut up for a while */
601 #define LOG_SHUT_UP 600 /* shut up for 10 minutes */
602 static int log_nmsgs = 0;
603
604 static void
resetlogging(void * arg)605 resetlogging(void *arg)
606 {
607 int nxttime = 60;
608 void *narg = NULL;
609
610 if (arg == NULL && log_nmsgs > LOG_MAX_MSGS) {
611 nxttime = LOG_SHUT_UP;
612 narg = (void *)&log_nmsgs; /* just need some valid void * */
613 syslog(LOG_WARNING, "logging too fast, shutting up for %d minutes",
614 LOG_SHUT_UP / 60);
615 } else {
616 log_nmsgs = 0;
617 }
618
619 timer_setTimer(nxttime, resetlogging, narg);
620 }
621
622 /*
623 * Log errors and other messages to the system log daemon and to stderr,
624 * according to the severity of the message and the current debug level.
625 * For errors of severity LOG_ERR or worse, terminate the program.
626 */
627 void
logit(int severity,int syserr,const char * format,...)628 logit(int severity, int syserr, const char *format, ...)
629 {
630 va_list ap;
631 static char fmt[211] = "warning - ";
632 char *msg;
633 char tbuf[20];
634 struct timeval now;
635 struct tm *thyme;
636 time_t t;
637
638 va_start(ap, format);
639 vsnprintf(&fmt[10], sizeof(fmt) - 10, format, ap);
640 va_end(ap);
641 msg = (severity == LOG_WARNING) ? fmt : &fmt[10];
642
643 switch (debug) {
644 case 0: break;
645 case 1: if (severity > LOG_NOTICE) break;
646 /* FALLTHROUGH */
647 case 2: if (severity > LOG_INFO ) break;
648 /* FALLTHROUGH */
649 default:
650 gettimeofday(&now,NULL);
651 t = now.tv_sec;
652 thyme = localtime(&t);
653 strftime(tbuf, sizeof(tbuf), "%X", thyme);
654 fprintf(stderr, "%s.%03ld %s", tbuf, (long)now.tv_usec / 1000,
655 msg);
656 if (syserr == 0)
657 fprintf(stderr, "\n");
658 else
659 fprintf(stderr, ": %s\n", strerror(syserr));
660 }
661
662 if (severity <= LOG_NOTICE) {
663 if (log_nmsgs++ < LOG_MAX_MSGS) {
664 if (syserr != 0) {
665 errno = syserr;
666 syslog(severity, "%s: %m", msg);
667 } else
668 syslog(severity, "%s", msg);
669 }
670
671 if (severity <= LOG_ERR) exit(1);
672 }
673 }
674
675 #ifdef DEBUG_MFC
676 void
md_log(int what,u_int32_t origin,u_int32_t mcastgrp)677 md_log(int what, u_int32_t origin, u_int32_t mcastgrp)
678 {
679 static FILE *f = NULL;
680 struct timeval tv;
681 u_int32_t buf[4];
682
683 if (!f) {
684 if ((f = fopen("/tmp/mrouted.clog", "w")) == NULL) {
685 logit(LOG_ERR, errno, "open /tmp/mrouted.clog");
686 }
687 }
688
689 gettimeofday(&tv, NULL);
690 buf[0] = tv.tv_sec;
691 buf[1] = what;
692 buf[2] = origin;
693 buf[3] = mcastgrp;
694
695 fwrite(buf, sizeof(u_int32_t), 4, f);
696 }
697 #endif
698