xref: /netbsd-src/sbin/routed/main.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: main.c,v 1.39 2004/07/06 16:43:18 wiz Exp $	*/
2 
3 /*
4  * Copyright (c) 1983, 1988, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgment:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include "defs.h"
37 #include "pathnames.h"
38 #ifdef sgi
39 #include "math.h"
40 #endif
41 #include <signal.h>
42 #include <fcntl.h>
43 #include <sys/file.h>
44 
45 __COPYRIGHT("@(#) Copyright (c) 1983, 1988, 1993\n"
46 	    "The Regents of the University of California."
47 	    "  All rights reserved.\n");
48 #ifdef __NetBSD__
49 __RCSID("$NetBSD: main.c,v 1.39 2004/07/06 16:43:18 wiz Exp $");
50 #elif defined(__FreeBSD__)
51 __RCSID("$FreeBSD$");
52 #else
53 __RCSID("Revision: 2.27 ");
54 #ident "Revision: 2.27 "
55 #endif
56 
57 #if defined(__NetBSD__)
58 #include <util.h>
59 #endif
60 
61 pid_t	mypid;
62 
63 naddr	myaddr;				/* system address */
64 char	myname[MAXHOSTNAMELEN+1];
65 
66 int	verbose;
67 
68 int	supplier;			/* supply or broadcast updates */
69 int	supplier_set;
70 int	ipforwarding = 1;		/* kernel forwarding on */
71 
72 int	default_gateway;		/* 1=advertise default */
73 int	background = 1;
74 int	ridhosts;			/* 1=reduce host routes */
75 int	mhome;				/* 1=want multi-homed host route */
76 int	advertise_mhome;		/* 1=must continue advertising it */
77 int	auth_ok = 1;			/* 1=ignore auth if we do not care */
78 
79 struct timeval epoch;			/* when started */
80 struct timeval clk, prev_clk;
81 static int usec_fudge;
82 struct timeval now;			/* current idea of time */
83 time_t	now_stale;
84 time_t	now_expire;
85 time_t	now_garbage;
86 
87 struct timeval next_bcast;		/* next general broadcast */
88 struct timeval no_flash = {		/* inhibit flash update */
89 	EPOCH+SUPPLY_INTERVAL, 0
90 };
91 
92 struct timeval flush_kern_timer;
93 
94 fd_set	*fdbitsp;
95 int	sock_max;
96 int	rip_sock = -1;			/* RIP socket */
97 struct interface *rip_sock_mcast;	/* current multicast interface */
98 int	rt_sock;			/* routing socket */
99 int	rt_sock_seqno;
100 
101 
102 static  int get_rip_sock(naddr, int);
103 static void timevalsub(struct timeval *, struct timeval *, struct timeval *);
104 
105 int
106 main(int argc,
107      char *argv[])
108 {
109 	int n, mib[4], off;
110 	size_t len;
111 	char *p, *q;
112 	const char *cp;
113 	struct timeval wtime, t2;
114 	time_t dt;
115 	fd_set *ibitsp = NULL;
116 	naddr p_net, p_mask;
117 	struct interface *ifp;
118 	struct parm parm;
119 	char *tracename = 0;
120 
121 
122 	/* Some shells are badly broken and send SIGHUP to backgrounded
123 	 * processes.
124 	 */
125 	signal(SIGHUP, SIG_IGN);
126 
127 	openlog("routed", LOG_PID, LOG_DAEMON);
128 	ftrace = stdout;
129 
130 	gettimeofday(&clk, 0);
131 	prev_clk = clk;
132 	epoch = clk;
133 	epoch.tv_sec -= EPOCH;
134 	now.tv_sec = EPOCH;
135 	now_stale = EPOCH - STALE_TIME;
136 	now_expire = EPOCH - EXPIRE_TIME;
137 	now_garbage = EPOCH - GARBAGE_TIME;
138 	wtime.tv_sec = 0;
139 
140 	(void)gethostname(myname, sizeof(myname) - 1);
141 	(void)gethost(myname, &myaddr);
142 
143 	while ((n = getopt(argc, argv, "sqdghmAtvT:F:P:")) != -1) {
144 		switch (n) {
145 		case 's':
146 			supplier = 1;
147 			supplier_set = 1;
148 			break;
149 
150 		case 'q':
151 			supplier = 0;
152 			supplier_set = 1;
153 			break;
154 
155 		case 'd':
156 			background = 0;
157 			break;
158 
159 		case 'g':
160 			memset(&parm, 0, sizeof(parm));
161 			parm.parm_d_metric = 1;
162 			cp = check_parms(&parm);
163 			if (cp != 0)
164 				msglog("bad -g: %s", cp);
165 			else
166 				default_gateway = 1;
167 			break;
168 
169 		case 'h':		/* suppress extra host routes */
170 			ridhosts = 1;
171 			break;
172 
173 		case 'm':		/* advertise host route */
174 			mhome = 1;	/* on multi-homed hosts */
175 			break;
176 
177 		case 'A':
178 			/* Ignore authentication if we do not care.
179 			 * Crazy as it is, that is what RFC 1723 requires.
180 			 */
181 			auth_ok = 0;
182 			break;
183 
184 		case 't':
185 			new_tracelevel++;
186 			break;
187 
188 		case 'T':
189 			tracename = optarg;
190 			break;
191 
192 		case 'F':		/* minimal routes for SLIP */
193 			n = FAKE_METRIC;
194 			p = strchr(optarg,',');
195 			if (p && *p != '\0') {
196 				n = (int)strtoul(p+1, &q, 0);
197 				if (*q == '\0'
198 				    && n <= HOPCNT_INFINITY-1
199 				    && n >= 1)
200 					*p = '\0';
201 			}
202 			if (!getnet(optarg, &p_net, &p_mask)) {
203 				msglog("bad network; \"-F %s\"",
204 				       optarg);
205 				break;
206 			}
207 			memset(&parm, 0, sizeof(parm));
208 			parm.parm_net = p_net;
209 			parm.parm_mask = p_mask;
210 			parm.parm_d_metric = n;
211 			cp = check_parms(&parm);
212 			if (cp != 0)
213 				msglog("bad -F: %s", cp);
214 			break;
215 
216 		case 'P':
217 			/* handle arbitrary parameters.
218 			 */
219 			q = strdup(optarg);
220 			cp = parse_parms(q, 0);
221 			if (cp != 0)
222 				msglog("%s in \"-P %s\"", cp, optarg);
223 			free(q);
224 			break;
225 
226 		case 'v':
227 			/* display version */
228 			verbose++;
229 			msglog("version 2.28");
230 			break;
231 
232 		default:
233 			goto usage;
234 		}
235 	}
236 	argc -= optind;
237 	argv += optind;
238 
239 	if (tracename == 0 && argc >= 1) {
240 		tracename = *argv++;
241 		argc--;
242 	}
243 	if (tracename != 0 && tracename[0] == '\0')
244 		goto usage;
245 	if (argc != 0) {
246 usage:
247 		logbad(0, "usage: routed [-sqdghmAtv] [-T tracefile]"
248 		       " [-F net[/mask[,metric]]] [-P parms]");
249 	}
250 	if (geteuid() != 0) {
251 		if (verbose)
252 			exit(0);
253 		logbad(0, "requires UID 0");
254 	}
255 
256 	mib[0] = CTL_NET;
257 	mib[1] = PF_INET;
258 	mib[2] = IPPROTO_IP;
259 	mib[3] = IPCTL_FORWARDING;
260 	len = sizeof(ipforwarding);
261 	if (sysctl(mib, 4, &ipforwarding, &len, 0, 0) < 0)
262 		LOGERR("sysctl(IPCTL_FORWARDING)");
263 
264 	if (!ipforwarding) {
265 		if (supplier)
266 			msglog("-s incompatible with ipforwarding=0");
267 		if (default_gateway) {
268 			msglog("-g incompatible with ipforwarding=0");
269 			default_gateway = 0;
270 		}
271 		supplier = 0;
272 		supplier_set = 1;
273 	}
274 	if (default_gateway) {
275 		if (supplier_set && !supplier) {
276 			msglog("-g and -q incompatible");
277 		} else {
278 			supplier = 1;
279 			supplier_set = 1;
280 		}
281 	}
282 
283 
284 	signal(SIGALRM, sigalrm);
285 	if (!background)
286 		signal(SIGHUP, sigterm);    /* SIGHUP fatal during debugging */
287 	signal(SIGTERM, sigterm);
288 	signal(SIGINT, sigterm);
289 	signal(SIGUSR1, sigtrace_on);
290 	signal(SIGUSR2, sigtrace_off);
291 
292 	/* get into the background */
293 #ifdef sgi
294 	if (0 > _daemonize(background ? 0 : (_DF_NOCHDIR|_DF_NOFORK),
295 			   STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO))
296 		BADERR(0, "_daemonize()");
297 #else
298 	if (background && daemon(0, 1) < 0)
299 		BADERR(0,"daemon()");
300 #endif
301 
302 #if defined(__NetBSD__)
303 	pidfile(NULL);
304 #endif
305 	mypid = getpid();
306 
307 	/* prepare socket connected to the kernel.
308 	 */
309 	rt_sock = socket(AF_ROUTE, SOCK_RAW, 0);
310 	if (rt_sock < 0)
311 		BADERR(1,"rt_sock = socket()");
312 	if (fcntl(rt_sock, F_SETFL, O_NONBLOCK) == -1)
313 		logbad(1, "fcntl(rt_sock) O_NONBLOCK: %s", strerror(errno));
314 	off = 0;
315 	if (setsockopt(rt_sock, SOL_SOCKET,SO_USELOOPBACK,
316 		       &off,sizeof(off)) < 0)
317 		LOGERR("setsockopt(SO_USELOOPBACK,0)");
318 
319 	fix_select();
320 
321 
322 	if (tracename != 0) {
323 		strlcpy(inittracename, tracename, sizeof(inittracename));
324 		set_tracefile(inittracename, "%s", -1);
325 	} else {
326 		tracelevel_msg("%s", -1);   /* turn on tracing to stdio */
327 	}
328 
329 	bufinit();
330 
331 	/* initialize radix tree */
332 	rtinit();
333 
334 	/* Pick a random part of the second for our output to minimize
335 	 * collisions.
336 	 *
337 	 * Start broadcasting after hearing from other routers, and
338 	 * at a random time so a bunch of systems do not get synchronized
339 	 * after a power failure.
340 	 */
341 	intvl_random(&next_bcast, EPOCH+MIN_WAITTIME, EPOCH+SUPPLY_INTERVAL);
342 	age_timer.tv_usec = next_bcast.tv_usec;
343 	age_timer.tv_sec = EPOCH+MIN_WAITTIME;
344 	rdisc_timer = next_bcast;
345 	ifinit_timer.tv_usec = next_bcast.tv_usec;
346 
347 	/* Collect an initial view of the world by checking the interface
348 	 * configuration and the kludge file.
349 	 */
350 	gwkludge();
351 	ifinit();
352 
353 	/* Ask for routes */
354 	rip_query();
355 	rdisc_sol();
356 
357 	/* Now turn off stdio if not tracing */
358 	if (new_tracelevel == 0)
359 		trace_close(background);
360 
361 	/* Loop forever, listening and broadcasting.
362 	 */
363 	for (;;) {
364 		prev_clk = clk;
365 		gettimeofday(&clk, 0);
366 		if (prev_clk.tv_sec == clk.tv_sec
367 		    && prev_clk.tv_usec == clk.tv_usec+usec_fudge) {
368 			/* Much of `routed` depends on time always advancing.
369 			 * On systems that do not guarantee that gettimeofday()
370 			 * produces unique timestamps even if called within
371 			 * a single tick, use trickery like that in classic
372 			 * BSD kernels.
373 			 */
374 			clk.tv_usec += ++usec_fudge;
375 
376 		} else {
377 			usec_fudge = 0;
378 
379 			timevalsub(&t2, &clk, &prev_clk);
380 			if (t2.tv_sec < 0
381 			    || t2.tv_sec > wtime.tv_sec + 5) {
382 				/* Deal with time changes before other
383 				 * housekeeping to keep everything straight.
384 				 */
385 				dt = t2.tv_sec;
386 				if (dt > 0)
387 					dt -= wtime.tv_sec;
388 				trace_act("time changed by %d sec", (int)dt);
389 				epoch.tv_sec += dt;
390 			}
391 		}
392 		timevalsub(&now, &clk, &epoch);
393 		now_stale = now.tv_sec - STALE_TIME;
394 		now_expire = now.tv_sec - EXPIRE_TIME;
395 		now_garbage = now.tv_sec - GARBAGE_TIME;
396 
397 		/* deal with signals that should affect tracing */
398 		set_tracelevel();
399 
400 		if (stopint != 0) {
401 			rip_bcast(0);
402 			rdisc_adv();
403 			trace_off("exiting with signal %d", stopint);
404 			exit(stopint | 128);
405 		}
406 
407 		/* look for new or dead interfaces */
408 		timevalsub(&wtime, &ifinit_timer, &now);
409 		if (wtime.tv_sec <= 0) {
410 			wtime.tv_sec = 0;
411 			ifinit();
412 			rip_query();
413 			continue;
414 		}
415 
416 		/* Check the kernel table occassionally for mysteriously
417 		 * evaporated routes
418 		 */
419 		timevalsub(&t2, &flush_kern_timer, &now);
420 		if (t2.tv_sec <= 0) {
421 			flush_kern();
422 			flush_kern_timer.tv_sec = (now.tv_sec
423 						   + CHECK_QUIET_INTERVAL);
424 			continue;
425 		}
426 		if (timercmp(&t2, &wtime, <))
427 			wtime = t2;
428 
429 		/* If it is time, then broadcast our routes.
430 		 */
431 		if (supplier || advertise_mhome) {
432 			timevalsub(&t2, &next_bcast, &now);
433 			if (t2.tv_sec <= 0) {
434 				/* Synchronize the aging and broadcast
435 				 * timers to minimize awakenings
436 				 */
437 				age(0);
438 
439 				rip_bcast(0);
440 
441 				/* It is desirable to send routing updates
442 				 * regularly.  So schedule the next update
443 				 * 30 seconds after the previous one was
444 				 * scheduled, instead of 30 seconds after
445 				 * the previous update was finished.
446 				 * Even if we just started after discovering
447 				 * a 2nd interface or were otherwise delayed,
448 				 * pick a 30-second aniversary of the
449 				 * original broadcast time.
450 				 */
451 				n = 1 + (0-t2.tv_sec)/SUPPLY_INTERVAL;
452 				next_bcast.tv_sec += n*SUPPLY_INTERVAL;
453 
454 				continue;
455 			}
456 
457 			if (timercmp(&t2, &wtime, <))
458 				wtime = t2;
459 		}
460 
461 		/* If we need a flash update, either do it now or
462 		 * set the delay to end when it is time.
463 		 *
464 		 * If we are within MIN_WAITTIME seconds of a full update,
465 		 * do not bother.
466 		 */
467 		if (need_flash
468 		    && supplier
469 		    && no_flash.tv_sec+MIN_WAITTIME < next_bcast.tv_sec) {
470 			/* accurate to the millisecond */
471 			if (!timercmp(&no_flash, &now, >))
472 				rip_bcast(1);
473 			timevalsub(&t2, &no_flash, &now);
474 			if (timercmp(&t2, &wtime, <))
475 				wtime = t2;
476 		}
477 
478 		/* trigger the main aging timer.
479 		 */
480 		timevalsub(&t2, &age_timer, &now);
481 		if (t2.tv_sec <= 0) {
482 			age(0);
483 			continue;
484 		}
485 		if (timercmp(&t2, &wtime, <))
486 			wtime = t2;
487 
488 		/* update the kernel routing table
489 		 */
490 		timevalsub(&t2, &need_kern, &now);
491 		if (t2.tv_sec <= 0) {
492 			age(0);
493 			continue;
494 		}
495 		if (timercmp(&t2, &wtime, <))
496 			wtime = t2;
497 
498 		/* take care of router discovery,
499 		 * but do it in the correct the millisecond
500 		 */
501 		if (!timercmp(&rdisc_timer, &now, >)) {
502 			rdisc_age(0);
503 			continue;
504 		}
505 		timevalsub(&t2, &rdisc_timer, &now);
506 		if (timercmp(&t2, &wtime, <))
507 			wtime = t2;
508 
509 
510 		/* wait for input or a timer to expire.
511 		 */
512 		trace_flush();
513 		if (ibitsp)
514 			free(ibitsp);
515 		ibitsp = (fd_set *)calloc(howmany(sock_max, NFDBITS),
516 		    sizeof(fd_mask));
517 		if (ibitsp == NULL)
518 			BADERR(1, "calloc");
519 		memcpy(ibitsp, fdbitsp, howmany(sock_max, NFDBITS) *
520 		    sizeof(fd_mask));
521 		n = select(sock_max, ibitsp, 0, 0, &wtime);
522 		if (n <= 0) {
523 			if (n < 0 && errno != EINTR && errno != EAGAIN)
524 				BADERR(1,"select");
525 			continue;
526 		}
527 
528 		if (FD_ISSET(rt_sock, ibitsp)) {
529 			read_rt();
530 			n--;
531 		}
532 		if (rdisc_sock >= 0 && FD_ISSET(rdisc_sock, ibitsp)) {
533 			read_d();
534 			n--;
535 		}
536 		if (rip_sock >= 0 && FD_ISSET(rip_sock, ibitsp)) {
537 			read_rip(rip_sock, 0);
538 			n--;
539 		}
540 
541 		for (ifp = ifnet; n > 0 && 0 != ifp; ifp = ifp->int_next) {
542 			if (ifp->int_rip_sock >= 0
543 			    && FD_ISSET(ifp->int_rip_sock, ibitsp)) {
544 				read_rip(ifp->int_rip_sock, ifp);
545 				n--;
546 			}
547 		}
548 	}
549 }
550 
551 
552 /* ARGSUSED */
553 void
554 sigalrm(int s UNUSED)
555 {
556 	/* Historically, SIGALRM would cause the daemon to check for
557 	 * new and broken interfaces.
558 	 */
559 	ifinit_timer.tv_sec = now.tv_sec;
560 	trace_act("SIGALRM");
561 }
562 
563 
564 /* watch for fatal signals */
565 void
566 sigterm(int sig)
567 {
568 	stopint = sig;
569 	(void)signal(sig, SIG_DFL);	/* catch it only once */
570 }
571 
572 
573 void
574 fix_select(void)
575 {
576 	struct interface *ifp;
577 
578 	sock_max = 0;
579 
580 	if (sock_max <= rt_sock)
581 		sock_max = rt_sock + 1;
582 	if (rip_sock >= 0)
583 		if (sock_max <= rip_sock)
584 			sock_max = rip_sock + 1;
585 	for (ifp = ifnet; 0 != ifp; ifp = ifp->int_next) {
586 		if (ifp->int_rip_sock >= 0)
587 			if (sock_max <= ifp->int_rip_sock)
588 				sock_max = ifp->int_rip_sock + 1;
589 	}
590 	if (rdisc_sock >= 0)
591 		if (sock_max <= rdisc_sock)
592 			sock_max = rdisc_sock + 1;
593 
594 	if (fdbitsp)
595 		free(fdbitsp);
596 	fdbitsp = (fd_set *)calloc(howmany(sock_max, NFDBITS),
597 	    sizeof(fd_mask));
598 	if (fdbitsp == NULL)
599 		BADERR(1, "calloc");
600 
601 	FD_SET(rt_sock, fdbitsp);
602 	if (rip_sock >= 0)
603 		FD_SET(rip_sock, fdbitsp);
604 	for (ifp = ifnet; 0 != ifp; ifp = ifp->int_next) {
605 		if (ifp->int_rip_sock >= 0)
606 			FD_SET(ifp->int_rip_sock, fdbitsp);
607 	}
608 	if (rdisc_sock >= 0)
609 		FD_SET(rdisc_sock, fdbitsp);
610 }
611 
612 
613 void
614 fix_sock(int sock,
615 	 const char *name)
616 {
617 	int on;
618 #define MIN_SOCKBUF (4*1024)
619 	static int rbuf;
620 
621 	if (fcntl(sock, F_SETFL, O_NONBLOCK) == -1)
622 		logbad(1, "fcntl(%s) O_NONBLOCK: %s",
623 		       name, strerror(errno));
624 	on = 1;
625 	if (setsockopt(sock, SOL_SOCKET,SO_BROADCAST, &on,sizeof(on)) < 0)
626 		msglog("setsockopt(%s,SO_BROADCAST): %s",
627 		       name, strerror(errno));
628 #ifdef USE_PASSIFNAME
629 	on = 1;
630 	if (setsockopt(sock, SOL_SOCKET, SO_PASSIFNAME, &on,sizeof(on)) < 0)
631 		msglog("setsockopt(%s,SO_PASSIFNAME): %s",
632 		       name, strerror(errno));
633 #endif
634 
635 	if (rbuf >= MIN_SOCKBUF) {
636 		if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
637 			       &rbuf, sizeof(rbuf)) < 0)
638 			msglog("setsockopt(%s,SO_RCVBUF=%d): %s",
639 			       name, rbuf, strerror(errno));
640 	} else {
641 		for (rbuf = 60*1024; ; rbuf -= 4096) {
642 			if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
643 				       &rbuf, sizeof(rbuf)) == 0) {
644 				trace_act("RCVBUF=%d", rbuf);
645 				break;
646 			}
647 			if (rbuf < MIN_SOCKBUF) {
648 				msglog("setsockopt(%s,SO_RCVBUF = %d): %s",
649 				       name, rbuf, strerror(errno));
650 				break;
651 			}
652 		}
653 	}
654 }
655 
656 
657 /* get a rip socket
658  */
659 static int				/* <0 or file descriptor */
660 get_rip_sock(naddr addr,
661 	     int serious)		/* 1=failure to bind is serious */
662 {
663 	struct sockaddr_in rsin;
664 	unsigned char ttl;
665 	int s;
666 
667 
668 	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
669 		BADERR(1,"rip_sock = socket()");
670 
671 	memset(&rsin, 0, sizeof(rsin));
672 #ifdef _HAVE_SIN_LEN
673 	rsin.sin_len = sizeof(rsin);
674 #endif
675 	rsin.sin_family = AF_INET;
676 	rsin.sin_port = htons(RIP_PORT);
677 	rsin.sin_addr.s_addr = addr;
678 	if (bind(s, (struct sockaddr *)&rsin, sizeof(rsin)) < 0) {
679 		if (serious)
680 			BADERR(errno != EADDRINUSE, "bind(rip_sock)");
681 		return -1;
682 	}
683 	fix_sock(s,"rip_sock");
684 
685 	ttl = 1;
686 	if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL,
687 		       &ttl, sizeof(ttl)) < 0)
688 		DBGERR(1,"rip_sock setsockopt(IP_MULTICAST_TTL)");
689 
690 	return s;
691 }
692 
693 
694 /* turn off main RIP socket */
695 void
696 rip_off(void)
697 {
698 	struct interface *ifp;
699 	naddr addr;
700 
701 
702 	if (rip_sock >= 0 && !mhome) {
703 		trace_act("turn off RIP");
704 
705 		(void)close(rip_sock);
706 		rip_sock = -1;
707 
708 		/* get non-broadcast sockets to listen to queries.
709 		 */
710 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
711 			if (ifp->int_state & IS_REMOTE)
712 				continue;
713 			if (ifp->int_rip_sock < 0) {
714 				addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
715 					? ifp->int_dstaddr
716 					: ifp->int_addr);
717 				ifp->int_rip_sock = get_rip_sock(addr, 0);
718 			}
719 		}
720 
721 		fix_select();
722 
723 		age(0);
724 	}
725 }
726 
727 
728 /* turn on RIP multicast input via an interface
729  */
730 static void
731 rip_mcast_on(struct interface *ifp)
732 {
733 	struct ip_mreq m;
734 
735 	if (!IS_RIP_IN_OFF(ifp->int_state)
736 	    && (ifp->int_if_flags & IFF_MULTICAST)
737 #ifdef MCAST_PPP_BUG
738 	    && !(ifp->int_if_flags & IFF_POINTOPOINT)
739 #endif
740 	    && !(ifp->int_state & IS_ALIAS)) {
741 		m.imr_multiaddr.s_addr = htonl(INADDR_RIP_GROUP);
742 #ifdef MCAST_IFINDEX
743 		m.imr_interface.s_addr = htonl(ifp->int_index);
744 #else
745 		m.imr_interface.s_addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
746 					  ? ifp->int_dstaddr
747 					  : ifp->int_addr);
748 #endif
749 		if (setsockopt(rip_sock,IPPROTO_IP, IP_ADD_MEMBERSHIP,
750 			       &m, sizeof(m)) < 0)
751 			LOGERR("setsockopt(IP_ADD_MEMBERSHIP RIP)");
752 	}
753 }
754 
755 
756 /* Prepare socket used for RIP.
757  */
758 void
759 rip_on(struct interface *ifp)
760 {
761 	/* If the main RIP socket is already alive, only start receiving
762 	 * multicasts for this interface.
763 	 */
764 	if (rip_sock >= 0) {
765 		if (ifp != 0)
766 			rip_mcast_on(ifp);
767 		return;
768 	}
769 
770 	/* If the main RIP socket is off and it makes sense to turn it on,
771 	 * then turn it on for all of the interfaces.
772 	 * It makes sense if either router discovery is off, or if
773 	 * router discover is on and at most one interface is doing RIP.
774 	 */
775 	if (rip_interfaces > 0 && (!rdisc_ok || rip_interfaces > 1)) {
776 		trace_act("turn on RIP");
777 
778 		/* Close all of the query sockets so that we can open
779 		 * the main socket.  SO_REUSEPORT is not a solution,
780 		 * since that would let two daemons bind to the broadcast
781 		 * socket.
782 		 */
783 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
784 			if (ifp->int_rip_sock >= 0) {
785 				(void)close(ifp->int_rip_sock);
786 				ifp->int_rip_sock = -1;
787 			}
788 		}
789 
790 		rip_sock = get_rip_sock(INADDR_ANY, 1);
791 		rip_sock_mcast = 0;
792 
793 		/* Do not advertise anything until we have heard something
794 		 */
795 		if (next_bcast.tv_sec < now.tv_sec+MIN_WAITTIME)
796 			next_bcast.tv_sec = now.tv_sec+MIN_WAITTIME;
797 
798 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
799 			ifp->int_query_time = NEVER;
800 			rip_mcast_on(ifp);
801 		}
802 		ifinit_timer.tv_sec = now.tv_sec;
803 
804 	} else if (ifp != 0
805 		   && !(ifp->int_state & IS_REMOTE)
806 		   && ifp->int_rip_sock < 0) {
807 		/* RIP is off, so ensure there are sockets on which
808 		 * to listen for queries.
809 		 */
810 		ifp->int_rip_sock = get_rip_sock(ifp->int_addr, 0);
811 	}
812 
813 	fix_select();
814 }
815 
816 
817 /* die if malloc(3) fails
818  */
819 void *
820 rtmalloc(size_t size,
821 	 const char *msg)
822 {
823 	void *p = malloc(size);
824 	if (p == 0)
825 		logbad(1,"malloc(%lu) failed in %s", (u_long)size, msg);
826 	return p;
827 }
828 
829 
830 /* get a random instant in an interval
831  */
832 void
833 intvl_random(struct timeval *tp,	/* put value here */
834 	     u_long lo,			/* value is after this second */
835 	     u_long hi)			/* and before this */
836 {
837 	tp->tv_sec = (time_t)(hi == lo
838 			      ? lo
839 			      : (lo + arc4random() % ((hi - lo))));
840 	tp->tv_usec = arc4random() % 1000000;
841 }
842 
843 
844 void
845 timevaladd(struct timeval *t1,
846 	   struct timeval *t2)
847 {
848 
849 	t1->tv_sec += t2->tv_sec;
850 	if ((t1->tv_usec += t2->tv_usec) >= 1000000) {
851 		t1->tv_sec++;
852 		t1->tv_usec -= 1000000;
853 	}
854 }
855 
856 
857 /* t1 = t2 - t3
858  */
859 static void
860 timevalsub(struct timeval *t1,
861 	   struct timeval *t2,
862 	   struct timeval *t3)
863 {
864 	t1->tv_sec = t2->tv_sec - t3->tv_sec;
865 	if ((t1->tv_usec = t2->tv_usec - t3->tv_usec) < 0) {
866 		t1->tv_sec--;
867 		t1->tv_usec += 1000000;
868 	}
869 }
870 
871 
872 /* put a message into the system log
873  */
874 void
875 msglog(const char *p, ...)
876 {
877 	va_list args;
878 
879 	trace_flush();
880 
881 	va_start(args, p);
882 	vsyslog(LOG_ERR, p, args);
883 	va_end(args);
884 
885 	if (ftrace != 0) {
886 		if (ftrace == stdout)
887 			(void)fputs("routed: ", ftrace);
888 		va_start(args, p);
889 		(void)vfprintf(ftrace, p, args);
890 		va_end(args);
891 		(void)fputc('\n', ftrace);
892 	}
893 }
894 
895 
896 /* Put a message about a bad system into the system log if
897  * we have not complained about it recently.
898  *
899  * It is desirable to complain about all bad systems, but not too often.
900  * In the worst case, it is not practical to keep track of all bad systems.
901  * For example, there can be many systems with the wrong password.
902  */
903 void
904 msglim(struct msg_limit *lim, naddr addr, const char *p, ...)
905 {
906 	va_list args;
907 	int i;
908 	struct msg_sub *ms1, *ms;
909 	const char *p1;
910 
911 	/* look for the oldest slot in the table
912 	 * or the slot for the bad router.
913 	 */
914 	ms = ms1 = lim->subs;
915 	for (i = MSG_SUBJECT_N; ; i--, ms1++) {
916 		if (i == 0) {
917 			/* Reuse a slot at most once every 10 minutes.
918 			 */
919 			if (lim->reuse > now.tv_sec) {
920 				ms = 0;
921 			} else {
922 				ms = ms1;
923 				lim->reuse = now.tv_sec + 10*60;
924 			}
925 			break;
926 		}
927 		if (ms->addr == addr) {
928 			/* Repeat a complaint about a given system at
929 			 * most once an hour.
930 			 */
931 			if (ms->until > now.tv_sec)
932 				ms = 0;
933 			break;
934 		}
935 		if (ms->until < ms1->until)
936 			ms = ms1;
937 	}
938 	if (ms != 0) {
939 		ms->addr = addr;
940 		ms->until = now.tv_sec + 60*60;	/* 60 minutes */
941 
942 		trace_flush();
943 		for (p1 = p; *p1 == ' '; p1++)
944 			continue;
945 		va_start(args, p);
946 		vsyslog(LOG_ERR, p1, args);
947 		va_end(args);
948 	}
949 
950 	/* always display the message if tracing */
951 	if (ftrace != 0) {
952 		va_start(args, p);
953 		(void)vfprintf(ftrace, p, args);
954 		(void)fputc('\n', ftrace);
955 		va_end(args);
956 	}
957 }
958 
959 
960 void
961 logbad(int dump, const char *p, ...)
962 {
963 	va_list args;
964 
965 	trace_flush();
966 
967 	va_start(args, p);
968 	vsyslog(LOG_ERR, p, args);
969 	va_end(args);
970 
971 	(void)fputs("routed: ", stderr);
972 	va_start(args, p);
973 	(void)vfprintf(stderr, p, args);
974 	va_end(args);
975 	(void)fputs("; giving up\n",stderr);
976 	(void)fflush(stderr);
977 
978 	if (dump)
979 		abort();
980 	exit(1);
981 }
982