xref: /freebsd/sbin/routed/main.c (revision a8445737e740901f5f2c8d24c12ef7fc8b00134e)
1 /*
2  * Copyright (c) 1983, 1988, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 char copyright[] =
36 "@(#) Copyright (c) 1983, 1988, 1993\n\
37 	The Regents of the University of California.  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #ifndef lint
41 #if 0
42 static char sccsid[] = "@(#)main.c	8.1 (Berkeley) 6/5/93";
43 #endif
44 static const char rcsid[] =
45 	"$Id$";
46 #endif /* not lint */
47 
48 #include "defs.h"
49 #ifdef sgi
50 #include "math.h"
51 #endif
52 #include <fcntl.h>
53 
54 pid_t	mypid;
55 
56 naddr	myaddr;				/* system address */
57 char	myname[MAXHOSTNAMELEN+1];
58 
59 int	supplier;			/* supply or broadcast updates */
60 int	supplier_set;
61 int	ipforwarding = 1;		/* kernel forwarding on */
62 
63 int	default_gateway;		/* 1=advertise default */
64 int	background = 1;
65 int	ridhosts;			/* 1=reduce host routes */
66 int	mhome;				/* 1=want multi-homed host route */
67 int	advertise_mhome;		/* 1=must continue advertising it */
68 int	auth_ok = 1;			/* 1=ignore auth if we do not care */
69 
70 struct timeval epoch;			/* when started */
71 struct timeval clk, prev_clk;
72 struct timeval now;			/* current idea of time */
73 time_t	now_stale;
74 time_t	now_expire;
75 time_t	now_garbage;
76 
77 struct timeval next_bcast;		/* next general broadcast */
78 struct timeval no_flash = {EPOCH+SUPPLY_INTERVAL};  /* inhibit flash update */
79 
80 fd_set	fdbits;
81 int	sock_max;
82 int	rip_sock = -1;			/* RIP socket */
83 struct interface *rip_sock_mcast;	/* current multicast interface */
84 int	rt_sock;			/* routing socket */
85 int	rt_sock_seqno;
86 
87 
88 static  int get_rip_sock(naddr, int);
89 static void timevalsub(struct timeval *, struct timeval *, struct timeval *);
90 
91 int
92 main(int argc,
93      char *argv[])
94 {
95 	int n, mib[4], off;
96 	size_t len;
97 	char *p, *q;
98 	struct timeval wtime, t2;
99 	time_t dt;
100 	fd_set ibits;
101 	naddr p_net, p_mask;
102 	struct interface *ifp;
103 	struct parm parm;
104 	char *tracename = 0;
105 
106 
107 	/* Some shells are badly broken and send SIGHUP to backgrounded
108 	 * processes.
109 	 */
110 	signal(SIGHUP, SIG_IGN);
111 
112 	openlog("routed", LOG_PID | LOG_ODELAY, LOG_DAEMON);
113 	ftrace = stdout;
114 
115 	gettimeofday(&clk, 0);
116 	prev_clk = clk;
117 	epoch = clk;
118 	epoch.tv_sec -= EPOCH;
119 	now.tv_sec = EPOCH;
120 	now_stale = EPOCH - STALE_TIME;
121 	now_expire = EPOCH - EXPIRE_TIME;
122 	now_garbage = EPOCH - GARBAGE_TIME;
123 	wtime.tv_sec = 0;
124 
125 	(void)gethostname(myname, sizeof(myname)-1);
126 	(void)gethost(myname, &myaddr);
127 
128 	while ((n = getopt(argc, argv, "sqdghmAtT:F:P:")) != -1) {
129 		switch (n) {
130 		case 's':
131 			supplier = 1;
132 			supplier_set = 1;
133 			break;
134 
135 		case 'q':
136 			supplier = 0;
137 			supplier_set = 1;
138 			break;
139 
140 		case 'd':
141 			background = 0;
142 			break;
143 
144 		case 'g':
145 			bzero(&parm, sizeof(parm));
146 			parm.parm_d_metric = 1;
147 			p = check_parms(&parm);
148 			if (p != 0)
149 				msglog("bad -g: %s", p);
150 			else
151 				default_gateway = 1;
152 			break;
153 
154 		case 'h':		/* suppress extra host routes */
155 			ridhosts = 1;
156 			break;
157 
158 		case 'm':		/* advertise host route */
159 			mhome = 1;	/* on multi-homed hosts */
160 			break;
161 
162 		case 'A':
163 			/* Ignore authentication if we do not care.
164 			 * Crazy as it is, that is what RFC 1723 requires.
165 			 */
166 			auth_ok = 0;
167 			break;
168 
169 		case 't':
170 			new_tracelevel++;
171 			break;
172 
173 		case 'T':
174 			tracename = optarg;
175 			break;
176 
177 		case 'F':		/* minimal routes for SLIP */
178 			n = FAKE_METRIC;
179 			p = strchr(optarg,',');
180 			if (p && *p != '\0') {
181 				n = (int)strtoul(p+1, &q, 0);
182 				if (*q == '\0'
183 				    && n <= HOPCNT_INFINITY-1
184 				    && n >= 1)
185 					*p = '\0';
186 			}
187 			if (!getnet(optarg, &p_net, &p_mask)) {
188 				msglog("bad network; \"-F %s\"",
189 				       optarg);
190 				break;
191 			}
192 			bzero(&parm, sizeof(parm));
193 			parm.parm_net = p_net;
194 			parm.parm_mask = p_mask;
195 			parm.parm_d_metric = n;
196 			p = check_parms(&parm);
197 			if (p != 0)
198 				msglog("bad -F: %s", p);
199 			break;
200 
201 		case 'P':
202 			/* handle arbitrary, (usually) per-interface
203 			 * parameters.
204 			 */
205 			p = parse_parms(optarg, 0);
206 			if (p != 0) {
207 				if (strcasecmp(p,optarg))
208 					msglog("%s in \"%s\"", p, optarg);
209 				else
210 					msglog("bad \"-P %s\"", optarg);
211 			}
212 			break;
213 
214 		default:
215 			goto usage;
216 		}
217 	}
218 	argc -= optind;
219 	argv += optind;
220 
221 	if (tracename == 0 && argc >= 1) {
222 		tracename = *argv++;
223 		argc--;
224 	}
225 	if (tracename != 0 && tracename[0] == '\0')
226 		goto usage;
227 	if (argc != 0) {
228 usage:
229 		logbad(0, "usage: routed [-sqdghmpAt] [-T tracefile]"
230 		       " [-F net[/mask[,metric]]] [-P parms]");
231 	}
232 	if (geteuid() != 0)
233 		logbad(0, "requires UID 0");
234 
235 	mib[0] = CTL_NET;
236 	mib[1] = PF_INET;
237 	mib[2] = IPPROTO_IP;
238 	mib[3] = IPCTL_FORWARDING;
239 	len = sizeof(ipforwarding);
240 	if (sysctl(mib, 4, &ipforwarding, &len, 0, 0) < 0)
241 		LOGERR("sysctl(IPCTL_FORWARDING)");
242 
243 	if (!ipforwarding) {
244 		if (supplier)
245 			msglog("-s incompatible with ipforwarding=0");
246 		if (default_gateway) {
247 			msglog("-g incompatible with ipforwarding=0");
248 			default_gateway = 0;
249 		}
250 		supplier = 0;
251 		supplier_set = 1;
252 	}
253 	if (default_gateway) {
254 		if (supplier_set && !supplier) {
255 			msglog("-g and -q incompatible");
256 		} else {
257 			supplier = 1;
258 			supplier_set = 1;
259 		}
260 	}
261 
262 
263 	signal(SIGALRM, sigalrm);
264 	if (!background)
265 		signal(SIGHUP, sigterm);    /* SIGHUP fatal during debugging */
266 	signal(SIGTERM, sigterm);
267 	signal(SIGINT, sigterm);
268 	signal(SIGUSR1, sigtrace_on);
269 	signal(SIGUSR2, sigtrace_off);
270 
271 	/* get into the background */
272 #ifdef sgi
273 	if (0 > _daemonize(background ? 0 : (_DF_NOCHDIR|_DF_NOFORK),
274 			   new_tracelevel == 0 ? -1 : STDOUT_FILENO,
275 			   new_tracelevel == 0 ? -1 : STDERR_FILENO,
276 			   -1))
277 		BADERR(0, "_daemonize()");
278 #else
279 	if (background && daemon(0, new_tracelevel) < 0)
280 		BADERR(0,"daemon()");
281 #endif
282 
283 	mypid = getpid();
284 	srandom((int)(clk.tv_sec ^ clk.tv_usec ^ mypid));
285 
286 	/* prepare socket connected to the kernel.
287 	 */
288 	rt_sock = socket(AF_ROUTE, SOCK_RAW, 0);
289 	if (rt_sock < 0)
290 		BADERR(1,"rt_sock = socket()");
291 	if (fcntl(rt_sock, F_SETFL, O_NONBLOCK) == -1)
292 		logbad(1, "fcntl(rt_sock) O_NONBLOCK: %s", strerror(errno));
293 	off = 0;
294 	if (setsockopt(rt_sock, SOL_SOCKET,SO_USELOOPBACK,
295 		       &off,sizeof(off)) < 0)
296 		LOGERR("setsockopt(SO_USELOOPBACK,0)");
297 
298 	fix_select();
299 
300 
301 	if (background && new_tracelevel == 0)
302 		ftrace = 0;
303 	if (tracename != 0) {
304 		strncpy(inittracename, tracename, sizeof(inittracename)-1);
305 		set_tracefile(inittracename, "%s\n", -1);
306 	} else {
307 		tracelevel_msg("%s\n", -1); /* turn on tracing to stdio */
308 	}
309 
310 	bufinit();
311 
312 	/* initialize radix tree */
313 	rtinit();
314 
315 	/* Pick a random part of the second for our output to minimize
316 	 * collisions.
317 	 *
318 	 * Start broadcasting after hearing from other routers, and
319 	 * at a random time so a bunch of systems do not get synchronized
320 	 * after a power failure.
321 	 */
322 	intvl_random(&next_bcast, EPOCH+MIN_WAITTIME, EPOCH+SUPPLY_INTERVAL);
323 	age_timer.tv_usec = next_bcast.tv_usec;
324 	age_timer.tv_sec = EPOCH+MIN_WAITTIME;
325 	rdisc_timer = next_bcast;
326 	ifinit_timer.tv_usec = next_bcast.tv_usec;
327 
328 	/* Collect an initial view of the world by checking the interface
329 	 * configuration and the kludge file.
330 	 */
331 	gwkludge();
332 	ifinit();
333 	flush_kern();
334 
335 	/* Ask for routes */
336 	rip_query();
337 	rdisc_sol();
338 
339 	/* Loop forever, listening and broadcasting.
340 	 */
341 	for (;;) {
342 		prev_clk = clk;
343 		gettimeofday(&clk, 0);
344 		timevalsub(&t2, &clk, &prev_clk);
345 		if (t2.tv_sec < 0
346 		    || t2.tv_sec > wtime.tv_sec + 5) {
347 			/* Deal with time changes before other housekeeping to
348 			 * keep everything straight.
349 			 */
350 			dt = t2.tv_sec;
351 			if (dt > 0)
352 				dt -= wtime.tv_sec;
353 			trace_act("time changed by %d sec", dt);
354 			epoch.tv_sec += dt;
355 		}
356 		timevalsub(&now, &clk, &epoch);
357 		now_stale = now.tv_sec - STALE_TIME;
358 		now_expire = now.tv_sec - EXPIRE_TIME;
359 		now_garbage = now.tv_sec - GARBAGE_TIME;
360 
361 		/* deal with signals that should affect tracing */
362 		set_tracelevel();
363 
364 		if (stopint != 0) {
365 			rip_bcast(0);
366 			rdisc_adv();
367 			trace_off("exiting with signal %d\n", stopint);
368 			exit(stopint | 128);
369 		}
370 
371 		/* look for new or dead interfaces */
372 		timevalsub(&wtime, &ifinit_timer, &now);
373 		if (wtime.tv_sec <= 0) {
374 			wtime.tv_sec = 0;
375 			ifinit();
376 			rip_query();
377 			continue;
378 		}
379 
380 		/* If it is time, then broadcast our routes.
381 		 */
382 		if (supplier || advertise_mhome) {
383 			timevalsub(&t2, &next_bcast, &now);
384 			if (t2.tv_sec <= 0) {
385 				/* Synchronize the aging and broadcast
386 				 * timers to minimize awakenings
387 				 */
388 				age(0);
389 
390 				rip_bcast(0);
391 
392 				/* It is desirable to send routing updates
393 				 * regularly.  So schedule the next update
394 				 * 30 seconds after the previous one was
395 				 * scheduled, instead of 30 seconds after
396 				 * the previous update was finished.
397 				 * Even if we just started after discovering
398 				 * a 2nd interface or were otherwise delayed,
399 				 * pick a 30-second aniversary of the
400 				 * original broadcast time.
401 				 */
402 				n = 1 + (0-t2.tv_sec)/SUPPLY_INTERVAL;
403 				next_bcast.tv_sec += n*SUPPLY_INTERVAL;
404 
405 				continue;
406 			}
407 
408 			if (timercmp(&t2, &wtime, <))
409 				wtime = t2;
410 		}
411 
412 		/* If we need a flash update, either do it now or
413 		 * set the delay to end when it is time.
414 		 *
415 		 * If we are within MIN_WAITTIME seconds of a full update,
416 		 * do not bother.
417 		 */
418 		if (need_flash
419 		    && supplier
420 		    && no_flash.tv_sec+MIN_WAITTIME < next_bcast.tv_sec) {
421 			/* accurate to the millisecond */
422 			if (!timercmp(&no_flash, &now, >))
423 				rip_bcast(1);
424 			timevalsub(&t2, &no_flash, &now);
425 			if (timercmp(&t2, &wtime, <))
426 				wtime = t2;
427 		}
428 
429 		/* trigger the main aging timer.
430 		 */
431 		timevalsub(&t2, &age_timer, &now);
432 		if (t2.tv_sec <= 0) {
433 			age(0);
434 			continue;
435 		}
436 		if (timercmp(&t2, &wtime, <))
437 			wtime = t2;
438 
439 		/* update the kernel routing table
440 		 */
441 		timevalsub(&t2, &need_kern, &now);
442 		if (t2.tv_sec <= 0) {
443 			age(0);
444 			continue;
445 		}
446 		if (timercmp(&t2, &wtime, <))
447 			wtime = t2;
448 
449 		/* take care of router discovery,
450 		 * but do it to the millisecond
451 		 */
452 		if (!timercmp(&rdisc_timer, &now, >)) {
453 			rdisc_age(0);
454 			continue;
455 		}
456 		timevalsub(&t2, &rdisc_timer, &now);
457 		if (timercmp(&t2, &wtime, <))
458 			wtime = t2;
459 
460 
461 		/* wait for input or a timer to expire.
462 		 */
463 		trace_flush();
464 		ibits = fdbits;
465 		n = select(sock_max, &ibits, 0, 0, &wtime);
466 		if (n <= 0) {
467 			if (n < 0 && errno != EINTR && errno != EAGAIN)
468 				BADERR(1,"select");
469 			continue;
470 		}
471 
472 		if (FD_ISSET(rt_sock, &ibits)) {
473 			read_rt();
474 			n--;
475 		}
476 		if (rdisc_sock >= 0 && FD_ISSET(rdisc_sock, &ibits)) {
477 			read_d();
478 			n--;
479 		}
480 		if (rip_sock >= 0 && FD_ISSET(rip_sock, &ibits)) {
481 			read_rip(rip_sock, 0);
482 			n--;
483 		}
484 
485 		for (ifp = ifnet; n > 0 && 0 != ifp; ifp = ifp->int_next) {
486 			if (ifp->int_rip_sock >= 0
487 			    && FD_ISSET(ifp->int_rip_sock, &ibits)) {
488 				read_rip(ifp->int_rip_sock, ifp);
489 				n--;
490 			}
491 		}
492 	}
493 }
494 
495 
496 /* ARGSUSED */
497 void
498 sigalrm(int s)
499 {
500 	/* Historically, SIGALRM would cause the daemon to check for
501 	 * new and broken interfaces.
502 	 */
503 	ifinit_timer.tv_sec = now.tv_sec;
504 	trace_act("SIGALRM");
505 }
506 
507 
508 /* watch for fatal signals */
509 void
510 sigterm(int sig)
511 {
512 	stopint = sig;
513 	(void)signal(sig, SIG_DFL);	/* catch it only once */
514 }
515 
516 
517 void
518 fix_select(void)
519 {
520 	struct interface *ifp;
521 
522 
523 	FD_ZERO(&fdbits);
524 	sock_max = 0;
525 
526 	FD_SET(rt_sock, &fdbits);
527 	if (sock_max <= rt_sock)
528 		sock_max = rt_sock+1;
529 	if (rip_sock >= 0) {
530 		FD_SET(rip_sock, &fdbits);
531 		if (sock_max <= rip_sock)
532 			sock_max = rip_sock+1;
533 	}
534 	for (ifp = ifnet; 0 != ifp; ifp = ifp->int_next) {
535 		if (ifp->int_rip_sock >= 0) {
536 			FD_SET(ifp->int_rip_sock, &fdbits);
537 			if (sock_max <= ifp->int_rip_sock)
538 				sock_max = ifp->int_rip_sock+1;
539 		}
540 	}
541 	if (rdisc_sock >= 0) {
542 		FD_SET(rdisc_sock, &fdbits);
543 		if (sock_max <= rdisc_sock)
544 			sock_max = rdisc_sock+1;
545 	}
546 }
547 
548 
549 void
550 fix_sock(int sock,
551 	 char *name)
552 {
553 	int on;
554 #define MIN_SOCKBUF (4*1024)
555 	static int rbuf;
556 
557 	if (fcntl(sock, F_SETFL, O_NONBLOCK) == -1)
558 		logbad(1, "fcntl(%s) O_NONBLOCK: %s",
559 		       name, strerror(errno));
560 	on = 1;
561 	if (setsockopt(sock, SOL_SOCKET,SO_BROADCAST, &on,sizeof(on)) < 0)
562 		msglog("setsockopt(%s,SO_BROADCAST): %s",
563 		       name, strerror(errno));
564 #ifdef USE_PASSIFNAME
565 	on = 1;
566 	if (setsockopt(sock, SOL_SOCKET, SO_PASSIFNAME, &on,sizeof(on)) < 0)
567 		msglog("setsockopt(%s,SO_PASSIFNAME): %s",
568 		       name, strerror(errno));
569 #endif
570 
571 	if (rbuf >= MIN_SOCKBUF) {
572 		if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
573 			       &rbuf, sizeof(rbuf)) < 0)
574 			msglog("setsockopt(%s,SO_RCVBUF=%d): %s",
575 			       name, rbuf, strerror(errno));
576 	} else {
577 		for (rbuf = 60*1024; ; rbuf -= 4096) {
578 			if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
579 				       &rbuf, sizeof(rbuf)) == 0) {
580 				trace_act("RCVBUF=%d", rbuf);
581 				break;
582 			}
583 			if (rbuf < MIN_SOCKBUF) {
584 				msglog("setsockopt(%s,SO_RCVBUF = %d): %s",
585 				       name, rbuf, strerror(errno));
586 				break;
587 			}
588 		}
589 	}
590 }
591 
592 
593 /* get a rip socket
594  */
595 static int				/* <0 or file descriptor */
596 get_rip_sock(naddr addr,
597 	     int serious)		/* 1=failure to bind is serious */
598 {
599 	struct sockaddr_in sin;
600 	unsigned char ttl;
601 	int s;
602 
603 
604 	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
605 		BADERR(1,"rip_sock = socket()");
606 
607 	bzero(&sin,sizeof(sin));
608 #ifdef _HAVE_SIN_LEN
609 	sin.sin_len = sizeof(sin);
610 #endif
611 	sin.sin_family = AF_INET;
612 	sin.sin_port = htons(RIP_PORT);
613 	sin.sin_addr.s_addr = addr;
614 	if (bind(s, (struct sockaddr *)&sin,sizeof(sin)) < 0) {
615 		if (serious)
616 			BADERR(errno != EADDRINUSE, "bind(rip_sock)");
617 		return -1;
618 	}
619 	fix_sock(s,"rip_sock");
620 
621 	ttl = 1;
622 	if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL,
623 		       &ttl, sizeof(ttl)) < 0)
624 		DBGERR(1,"rip_sock setsockopt(IP_MULTICAST_TTL)");
625 
626 	return s;
627 }
628 
629 
630 /* turn off main RIP socket */
631 void
632 rip_off(void)
633 {
634 	struct interface *ifp;
635 	register naddr addr;
636 
637 
638 	if (rip_sock >= 0 && !mhome) {
639 		trace_act("turn off RIP");
640 
641 		(void)close(rip_sock);
642 		rip_sock = -1;
643 
644 		/* get non-broadcast sockets to listen to queries.
645 		 */
646 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
647 			if (ifp->int_state & IS_REMOTE)
648 				continue;
649 			if (ifp->int_rip_sock < 0) {
650 				addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
651 					? ifp->int_dstaddr
652 					: ifp->int_addr);
653 				ifp->int_rip_sock = get_rip_sock(addr, 0);
654 			}
655 		}
656 
657 		fix_select();
658 
659 		age(0);
660 	}
661 }
662 
663 
664 /* turn on RIP multicast input via an interface
665  */
666 static void
667 rip_mcast_on(struct interface *ifp)
668 {
669 	struct ip_mreq m;
670 
671 	if (!IS_RIP_IN_OFF(ifp->int_state)
672 	    && (ifp->int_if_flags & IFF_MULTICAST)
673 #ifdef MCAST_PPP_BUG
674 	    && !(ifp->int_if_flags & IFF_POINTOPOINT)
675 #endif
676 	    && !(ifp->int_state & IS_ALIAS)) {
677 		m.imr_multiaddr.s_addr = htonl(INADDR_RIP_GROUP);
678 		m.imr_interface.s_addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
679 					  ? ifp->int_dstaddr
680 					  : ifp->int_addr);
681 		if (setsockopt(rip_sock,IPPROTO_IP, IP_ADD_MEMBERSHIP,
682 			       &m, sizeof(m)) < 0)
683 			LOGERR("setsockopt(IP_ADD_MEMBERSHIP RIP)");
684 	}
685 }
686 
687 
688 /* Prepare socket used for RIP.
689  */
690 void
691 rip_on(struct interface *ifp)
692 {
693 	/* If the main RIP socket is already alive, only start receiving
694 	 * multicasts for this interface.
695 	 */
696 	if (rip_sock >= 0) {
697 		if (ifp != 0)
698 			rip_mcast_on(ifp);
699 		return;
700 	}
701 
702 	/* If the main RIP socket is off and it makes sense to turn it on,
703 	 * then turn it on for all of the interfaces.
704 	 */
705 	if (rip_interfaces > 0 && !rdisc_ok) {
706 		trace_act("turn on RIP");
707 
708 		/* Close all of the query sockets so that we can open
709 		 * the main socket.  SO_REUSEPORT is not a solution,
710 		 * since that would let two daemons bind to the broadcast
711 		 * socket.
712 		 */
713 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
714 			if (ifp->int_rip_sock >= 0) {
715 				(void)close(ifp->int_rip_sock);
716 				ifp->int_rip_sock = -1;
717 			}
718 		}
719 
720 		rip_sock = get_rip_sock(INADDR_ANY, 1);
721 		rip_sock_mcast = 0;
722 
723 		/* Do not advertise anything until we have heard something
724 		 */
725 		if (next_bcast.tv_sec < now.tv_sec+MIN_WAITTIME)
726 			next_bcast.tv_sec = now.tv_sec+MIN_WAITTIME;
727 
728 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
729 			ifp->int_query_time = NEVER;
730 			rip_mcast_on(ifp);
731 		}
732 		ifinit_timer.tv_sec = now.tv_sec;
733 
734 	} else if (ifp != 0
735 		   && !(ifp->int_state & IS_REMOTE)
736 		   && ifp->int_rip_sock < 0) {
737 		/* RIP is off, so ensure there are sockets on which
738 		 * to listen for queries.
739 		 */
740 		ifp->int_rip_sock = get_rip_sock(ifp->int_addr, 0);
741 	}
742 
743 	fix_select();
744 }
745 
746 
747 /* die if malloc(3) fails
748  */
749 void *
750 rtmalloc(size_t size,
751 	 char *msg)
752 {
753 	void *p = malloc(size);
754 	if (p == NULL)
755 		logbad(1,"malloc() failed in %s", msg);
756 	return p;
757 }
758 
759 
760 /* get a random instant in an interval
761  */
762 void
763 intvl_random(struct timeval *tp,	/* put value here */
764 	     u_long lo,			/* value is after this second */
765 	     u_long hi)			/* and before this */
766 {
767 	tp->tv_sec = (time_t)(hi == lo
768 			      ? lo
769 			      : (lo + random() % ((hi - lo))));
770 	tp->tv_usec = random() % 1000000;
771 }
772 
773 
774 void
775 timevaladd(struct timeval *t1,
776 	   struct timeval *t2)
777 {
778 
779 	t1->tv_sec += t2->tv_sec;
780 	if ((t1->tv_usec += t2->tv_usec) >= 1000000) {
781 		t1->tv_sec++;
782 		t1->tv_usec -= 1000000;
783 	}
784 }
785 
786 
787 /* t1 = t2 - t3
788  */
789 static void
790 timevalsub(struct timeval *t1,
791 	   struct timeval *t2,
792 	   struct timeval *t3)
793 {
794 	t1->tv_sec = t2->tv_sec - t3->tv_sec;
795 	if ((t1->tv_usec = t2->tv_usec - t3->tv_usec) < 0) {
796 		t1->tv_sec--;
797 		t1->tv_usec += 1000000;
798 	}
799 }
800 
801 
802 /* put a message into the system log
803  */
804 void
805 msglog(char *p, ...)
806 {
807 	va_list args;
808 
809 	trace_flush();
810 
811 	va_start(args, p);
812 	vsyslog(LOG_ERR, p, args);
813 
814 	if (ftrace != 0) {
815 		if (ftrace == stdout)
816 			(void)fputs("routed: ", ftrace);
817 		(void)vfprintf(ftrace, p, args);
818 		(void)fputc('\n', ftrace);
819 	}
820 }
821 
822 
823 /* Put a message about a bad system into the system log if
824  * we have not complained about it recently.
825  *
826  * It is desirable to complain about all bad systems, but not too often.
827  * In the worst case, it is not practical to keep track of all bad systems.
828  * For example, there can be many systems with the wrong password.
829  */
830 void
831 msglim(struct msg_limit *lim, naddr addr, char *p, ...)
832 {
833 	va_list args;
834 	int i;
835 	struct msg_sub *ms1, *ms;
836 	char *p1;
837 
838 	va_start(args, p);
839 
840 	/* look for the oldest slot in the table
841 	 * or the slot for the bad router.
842 	 */
843 	ms = ms1 = lim->subs;
844 	for (i = MSG_SUBJECT_N; ; i--, ms1++) {
845 		if (i == 0) {
846 			/* Reuse a slot at most once every 10 minutes.
847 			 */
848 			if (lim->reuse > now.tv_sec) {
849 				ms = 0;
850 			} else {
851 				ms = ms1;
852 				lim->reuse = now.tv_sec + 10*60;
853 			}
854 			break;
855 		}
856 		if (ms->addr == addr) {
857 			/* Repeat a complaint about a given system at
858 			 * most once an hour.
859 			 */
860 			if (ms->until > now.tv_sec)
861 				ms = 0;
862 			break;
863 		}
864 		if (ms->until < ms1->until)
865 			ms = ms1;
866 	}
867 	if (ms != 0) {
868 		ms->addr = addr;
869 		ms->until = now.tv_sec + 60*60;	/* 60 minutes */
870 
871 		trace_flush();
872 		for (p1 = p; *p1 == ' '; p1++)
873 			continue;
874 		vsyslog(LOG_ERR, p1, args);
875 	}
876 
877 	/* always display the message if tracing */
878 	if (ftrace != 0) {
879 		(void)vfprintf(ftrace, p, args);
880 		(void)fputc('\n', ftrace);
881 	}
882 }
883 
884 
885 void
886 logbad(int dump, char *p, ...)
887 {
888 	va_list args;
889 
890 	trace_flush();
891 
892 	va_start(args, p);
893 	vsyslog(LOG_ERR, p, args);
894 
895 	(void)fputs("routed: ", stderr);
896 	(void)vfprintf(stderr, p, args);
897 	(void)fputs("; giving up\n",stderr);
898 	(void)fflush(stderr);
899 
900 	if (dump)
901 		abort();
902 	exit(1);
903 }
904