xref: /netbsd-src/sbin/routed/main.c (revision 76dfffe33547c37f8bdd446e3e4ab0f3c16cea4b)
1 /*	$NetBSD: main.c,v 1.15 1996/09/24 16:24:15 christos 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 acknowledgement:
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 char copyright[] =
37 "@(#) Copyright (c) 1983, 1988, 1993\n\
38 	The Regents of the University of California.  All rights reserved.\n";
39 #if !defined(lint) && !defined(sgi) && !defined(__NetBSD__)
40 static char sccsid[] = "@(#)main.c	8.1 (Berkeley) 6/5/93";
41 #elif defined(__NetBSD__)
42 static char rcsid[] = "$NetBSD: main.c,v 1.15 1996/09/24 16:24:15 christos Exp $";
43 #endif
44 
45 #include "defs.h"
46 #include "pathnames.h"
47 #ifdef sgi
48 #include "math.h"
49 #endif
50 #include <signal.h>
51 #include <fcntl.h>
52 #include <sys/file.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 adverising 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_addr, p_mask;
102 	struct interface *ifp;
103 	struct parm parm;
104 	char *tracename = 0;
105 
106 
107 	openlog("routed", LOG_PID | LOG_ODELAY, LOG_DAEMON);
108 	ftrace = stdout;
109 
110 	gettimeofday(&clk, 0);
111 	prev_clk = clk;
112 	epoch = clk;
113 	epoch.tv_sec -= EPOCH;
114 	now.tv_sec = EPOCH;
115 	now_stale = EPOCH - STALE_TIME;
116 	now_expire = EPOCH - EXPIRE_TIME;
117 	now_garbage = EPOCH - GARBAGE_TIME;
118 	wtime.tv_sec = 0;
119 
120 	(void)gethostname(myname, sizeof(myname)-1);
121 	(void)gethost(myname, &myaddr);
122 
123 	while ((n = getopt(argc, argv, "sqdghmpAtT:F:P:")) != EOF) {
124 		switch (n) {
125 		case 's':
126 			supplier = 1;
127 			supplier_set = 1;
128 			break;
129 
130 		case 'q':
131 			supplier = 0;
132 			supplier_set = 1;
133 			break;
134 
135 		case 'd':
136 			background = 0;
137 			break;
138 
139 		case 'g':
140 			bzero(&parm, sizeof(parm));
141 			parm.parm_d_metric = 1;
142 			p = check_parms(&parm);
143 			if (p != 0)
144 				msglog("bad -g: %s", p);
145 			else
146 				default_gateway = 1;
147 			break;
148 
149 		case 'h':		/* suppress extra host routes */
150 			ridhosts = 1;
151 			break;
152 
153 		case 'm':		/* advertise host route */
154 			mhome = 1;	/* on multi-homed hosts */
155 			break;
156 
157 		case 'A':
158 			/* Ignore authentication if we do not care.
159 			 * Crazy as it is, that is what RFC 1723 requires.
160 			 */
161 			auth_ok = 0;
162 			break;
163 
164 		case 't':
165 			new_tracelevel++;
166 			break;
167 
168 		case 'T':
169 			tracename = optarg;
170 			break;
171 
172 		case 'F':		/* minimal routes for SLIP */
173 			n = HOPCNT_INFINITY-2;
174 			p = strchr(optarg,',');
175 			if (p && *p != '\0') {
176 				n = (int)strtoul(p+1, &q, 0);
177 				if (*q == '\0'
178 				    && n <= HOPCNT_INFINITY-1
179 				    && n >= 1)
180 					*p = '\0';
181 			}
182 			if (!getnet(optarg, &p_addr, &p_mask)) {
183 				msglog("bad network; \"-F %s\"",
184 				       optarg);
185 				break;
186 			}
187 			bzero(&parm, sizeof(parm));
188 			parm.parm_addr_h = ntohl(p_addr);
189 			parm.parm_mask = p_mask;
190 			parm.parm_d_metric = n;
191 			p = check_parms(&parm);
192 			if (p != 0)
193 				msglog("bad -F: %s", p);
194 			break;
195 
196 		case 'P':
197 			/* handle arbirary, (usually) per-interface
198 			 * parameters.
199 			 */
200 			p = parse_parms(optarg);
201 			if (p != 0)
202 				msglog("bad \"%s\" in \"%s\"",
203 				       p, optarg);
204 			break;
205 
206 		default:
207 			goto usage;
208 		}
209 	}
210 	argc -= optind;
211 	argv += optind;
212 
213 	if (tracename == 0 && argc >= 1) {
214 		tracename = *argv++;
215 		argc--;
216 	}
217 	if (argc != 0) {
218 usage:
219 		logbad(0, "usage: routed [-sqdghmpAt] [-T /tracefile]"
220 		       " [-F net[,metric]] [-P parms]");
221 	}
222 	if (geteuid() != 0)
223 		logbad(0, "requires UID 0");
224 
225 	mib[0] = CTL_NET;
226 	mib[1] = PF_INET;
227 	mib[2] = IPPROTO_IP;
228 	mib[3] = IPCTL_FORWARDING;
229 	len = sizeof(ipforwarding);
230 	if (sysctl(mib, 4, &ipforwarding, &len, 0, 0) < 0)
231 		LOGERR("sysctl(IPCTL_FORWARDING)");
232 
233 	if (!ipforwarding) {
234 		if (supplier)
235 			msglog("-s incompatible with ipforwarding=0");
236 		if (default_gateway) {
237 			msglog("-g incompatible with ipforwarding=0");
238 			default_gateway = 0;
239 		}
240 		supplier = 0;
241 		supplier_set = 1;
242 	}
243 	if (default_gateway) {
244 		if (supplier_set && !supplier) {
245 			msglog("-g and -q incompatible");
246 		} else {
247 			supplier = 1;
248 			supplier_set = 1;
249 		}
250 	}
251 
252 
253 	signal(SIGALRM, sigalrm);
254 	if (!background)
255 		signal(SIGHUP, sigterm);    /* SIGHUP fatal during debugging */
256 	else
257 		signal(SIGHUP, SIG_IGN);
258 	signal(SIGTERM, sigterm);
259 	signal(SIGINT, sigterm);
260 	signal(SIGUSR1, sigtrace_on);
261 	signal(SIGUSR2, sigtrace_off);
262 
263 	/* get into the background */
264 	if (background) {
265 #ifdef sgi
266 		if (0 > _daemonize(_DF_NOCHDIR,
267 				   new_tracelevel == 0 ? -1 : STDOUT_FILENO,
268 				   new_tracelevel == 0 ? -1 : STDERR_FILENO,
269 				   -1))
270 			BADERR(0, "_daemonize()");
271 #else
272 		if (daemon(1, 1) < 0)
273 			BADERR(0,"daemon()");
274 #endif
275 	}
276 
277 	mypid = getpid();
278 	srandom((int)(clk.tv_sec ^ clk.tv_usec ^ mypid));
279 
280 	/* prepare socket connected to the kernel.
281 	 */
282 	rt_sock = socket(AF_ROUTE, SOCK_RAW, 0);
283 	if (rt_sock < 0)
284 		BADERR(1,"rt_sock = socket()");
285 	if (fcntl(rt_sock, F_SETFL, O_NONBLOCK) == -1)
286 		logbad(1, "fcntl(rt_sock) O_NONBLOCK: %s", strerror(errno));
287 	off = 0;
288 	if (setsockopt(rt_sock, SOL_SOCKET,SO_USELOOPBACK,
289 		       &off,sizeof(off)) < 0)
290 		LOGERR("setsockopt(SO_USELOOPBACK,0)");
291 
292 	fix_select();
293 
294 
295 	if (background && new_tracelevel == 0)
296 		ftrace = 0;
297 	if (tracename != 0) {
298 		trace_on(tracename, 1);
299 		if (new_tracelevel == 0)	/* use stdout if file is bad */
300 			new_tracelevel = 1;
301 	}
302 	set_tracelevel();
303 
304 	/* initialize radix tree */
305 	rtinit();
306 
307 	/* Pick a random part of the second for our output to minimize
308 	 * collisions.
309 	 *
310 	 * Start broadcasting after hearing from other routers, and
311 	 * at a random time so a bunch of systems do not get synchronized
312 	 * after a power failure.
313 	 */
314 	intvl_random(&next_bcast, EPOCH+MIN_WAITTIME, EPOCH+SUPPLY_INTERVAL);
315 	age_timer.tv_usec = next_bcast.tv_usec;
316 	age_timer.tv_sec = EPOCH+MIN_WAITTIME;
317 	rdisc_timer = next_bcast;
318 	ifinit_timer.tv_usec = next_bcast.tv_usec;
319 
320 	/* Collect an initial view of the world by checking the interface
321 	 * configuration and the kludge file.
322 	 */
323 	gwkludge();
324 	ifinit();
325 	flush_kern();
326 
327 	/* Ask for routes */
328 	rip_query();
329 	if (!supplier)
330 		rdisc_sol();
331 
332 	/* Loop forever, listening and broadcasting.
333 	 */
334 	for (;;) {
335 		prev_clk = clk;
336 		gettimeofday(&clk, 0);
337 		timevalsub(&t2, &clk, &prev_clk);
338 		if (t2.tv_sec < 0
339 		    || t2.tv_sec > wtime.tv_sec + 5) {
340 			/* Deal with time changes before other housekeeping to
341 			 * keep everything straight.
342 			 */
343 			dt = t2.tv_sec;
344 			if (dt > 0)
345 				dt -= wtime.tv_sec;
346 			trace_act("time changed by %d sec\n", dt);
347 			epoch.tv_sec += dt;
348 		}
349 		timevalsub(&now, &clk, &epoch);
350 		now_stale = now.tv_sec - STALE_TIME;
351 		now_expire = now.tv_sec - EXPIRE_TIME;
352 		now_garbage = now.tv_sec - GARBAGE_TIME;
353 
354 		/* deal with interrupts that should affect tracing */
355 		set_tracelevel();
356 
357 		if (stopint != 0) {
358 			if (supplier) {
359 				rip_bcast(0);
360 				rdisc_adv();
361 			}
362 			trace_off("exiting with signal %d\n", stopint);
363 			exit(stopint | 128);
364 		}
365 
366 		/* look for new or dead interfaces */
367 		timevalsub(&wtime, &ifinit_timer, &now);
368 		if (wtime.tv_sec <= 0) {
369 			wtime.tv_sec = 0;
370 			ifinit();
371 			rip_query();
372 			continue;
373 		}
374 
375 		/* If it is time, then broadcast our routes.
376 		 */
377 		if (supplier || advertise_mhome) {
378 			timevalsub(&t2, &next_bcast, &now);
379 			if (t2.tv_sec <= 0) {
380 				/* Synchronize the aging and broadcast
381 				 * timers to minimize awakenings
382 				 */
383 				age(0);
384 
385 				rip_bcast(0);
386 
387 				/* It is desirable to send routing updates
388 				 * regularly.  So schedule the next update
389 				 * 30 seconds after the previous one was
390 				 * secheduled, instead of 30 seconds after
391 				 * the previous update was finished.
392 				 * Even if we just started after discovering
393 				 * a 2nd interface or were otherwise delayed,
394 				 * pick a 30-second aniversary of the
395 				 * original broadcast time.
396 				 */
397 				n = 1 + (0-t2.tv_sec)/SUPPLY_INTERVAL;
398 				next_bcast.tv_sec += n*SUPPLY_INTERVAL;
399 
400 				continue;
401 			}
402 
403 			if (timercmp(&t2, &wtime, <))
404 				wtime = t2;
405 		}
406 
407 		/* If we need a flash update, either do it now or
408 		 * set the delay to end when it is time.
409 		 *
410 		 * If we are within MIN_WAITTIME seconds of a full update,
411 		 * do not bother.
412 		 */
413 		if (need_flash
414 		    && supplier
415 		    && no_flash.tv_sec+MIN_WAITTIME < next_bcast.tv_sec) {
416 			/* accurate to the millisecond */
417 			if (!timercmp(&no_flash, &now, >))
418 				rip_bcast(1);
419 			timevalsub(&t2, &no_flash, &now);
420 			if (timercmp(&t2, &wtime, <))
421 				wtime = t2;
422 		}
423 
424 		/* trigger the main aging timer.
425 		 */
426 		timevalsub(&t2, &age_timer, &now);
427 		if (t2.tv_sec <= 0) {
428 			age(0);
429 			continue;
430 		}
431 		if (timercmp(&t2, &wtime, <))
432 			wtime = t2;
433 
434 		/* update the kernel routing table
435 		 */
436 		timevalsub(&t2, &need_kern, &now);
437 		if (t2.tv_sec <= 0) {
438 			age(0);
439 			continue;
440 		}
441 		if (timercmp(&t2, &wtime, <))
442 			wtime = t2;
443 
444 		/* take care of router discovery,
445 		 * but do it to the millisecond
446 		 */
447 		if (!timercmp(&rdisc_timer, &now, >)) {
448 			rdisc_age(0);
449 			continue;
450 		}
451 		timevalsub(&t2, &rdisc_timer, &now);
452 		if (timercmp(&t2, &wtime, <))
453 			wtime = t2;
454 
455 
456 		/* wait for input or a timer to expire.
457 		 */
458 		trace_flush();
459 		ibits = fdbits;
460 		n = select(sock_max, &ibits, 0, 0, &wtime);
461 		if (n <= 0) {
462 			if (n < 0 && errno != EINTR && errno != EAGAIN)
463 				BADERR(1,"select");
464 			continue;
465 		}
466 
467 		if (FD_ISSET(rt_sock, &ibits)) {
468 			read_rt();
469 			n--;
470 		}
471 		if (rdisc_sock >= 0 && FD_ISSET(rdisc_sock, &ibits)) {
472 			read_d();
473 			n--;
474 		}
475 		if (rip_sock >= 0 && FD_ISSET(rip_sock, &ibits)) {
476 			read_rip(rip_sock, 0);
477 			n--;
478 		}
479 
480 		for (ifp = ifnet; n > 0 && 0 != ifp; ifp = ifp->int_next) {
481 			if (ifp->int_rip_sock >= 0
482 			    && FD_ISSET(ifp->int_rip_sock, &ibits)) {
483 				read_rip(ifp->int_rip_sock, ifp);
484 				n--;
485 			}
486 		}
487 	}
488 }
489 
490 
491 /* ARGSUSED */
492 void
493 sigalrm(int sig)
494 {
495 	/* Historically, SIGALRM would cause the daemon to check for
496 	 * new and broken interfaces.
497 	 */
498 	ifinit_timer.tv_sec = now.tv_sec;
499 	trace_act("SIGALRM\n");
500 }
501 
502 
503 /* watch for fatal signals */
504 void
505 sigterm(int sig)
506 {
507 	stopint = sig;
508 	(void)signal(sig, SIG_DFL);	/* catch it only once */
509 }
510 
511 
512 void
513 fix_select(void)
514 {
515 	struct interface *ifp;
516 
517 
518 	FD_ZERO(&fdbits);
519 	sock_max = 0;
520 
521 	FD_SET(rt_sock, &fdbits);
522 	if (sock_max <= rt_sock)
523 		sock_max = rt_sock+1;
524 	if (rip_sock >= 0) {
525 		FD_SET(rip_sock, &fdbits);
526 		if (sock_max <= rip_sock)
527 			sock_max = rip_sock+1;
528 	}
529 	for (ifp = ifnet; 0 != ifp; ifp = ifp->int_next) {
530 		if (ifp->int_rip_sock >= 0) {
531 			FD_SET(ifp->int_rip_sock, &fdbits);
532 			if (sock_max <= ifp->int_rip_sock)
533 				sock_max = ifp->int_rip_sock+1;
534 		}
535 	}
536 	if (rdisc_sock >= 0) {
537 		FD_SET(rdisc_sock, &fdbits);
538 		if (sock_max <= rdisc_sock)
539 			sock_max = rdisc_sock+1;
540 	}
541 }
542 
543 
544 void
545 fix_sock(int sock,
546 	 char *name)
547 {
548 	int on;
549 #define MIN_SOCKBUF (4*1024)
550 	static int rbuf;
551 
552 	if (fcntl(sock, F_SETFL, O_NONBLOCK) == -1)
553 		logbad(1, "fcntl(%s) O_NONBLOCK: %s",
554 		       name, strerror(errno));
555 	on = 1;
556 	if (setsockopt(sock, SOL_SOCKET,SO_BROADCAST,
557 		       &on,sizeof(on)) < 0)
558 		msglog("setsockopt(%s,SO_BROADCAST): %s",
559 		       name, strerror(errno));
560 	if (rbuf >= MIN_SOCKBUF) {
561 		if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
562 			       &rbuf, sizeof(rbuf)) < 0)
563 			msglog("setsockopt(%s,SO_RCVBUF=%d): %s",
564 			       name, rbuf, strerror(errno));
565 	} else {
566 		for (rbuf = 60*1024; ; rbuf -= 4096) {
567 			if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
568 				       &rbuf, sizeof(rbuf)) == 0) {
569 				trace_act("RCVBUF=%d\n", rbuf);
570 				break;
571 			}
572 			if (rbuf < MIN_SOCKBUF) {
573 				msglog("setsockopt(%s,SO_RCVBUF = %d): %s",
574 				       name, rbuf, strerror(errno));
575 				break;
576 			}
577 		}
578 	}
579 }
580 
581 
582 /* get a rip socket
583  */
584 static int				/* <0 or file descriptor */
585 get_rip_sock(naddr addr,
586 	     int serious)		/* 1=failure to bind is serious */
587 {
588 	struct sockaddr_in sin;
589 	unsigned char ttl;
590 	int s;
591 
592 
593 	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
594 		BADERR(1,"rip_sock = socket()");
595 
596 	bzero(&sin,sizeof(sin));
597 #ifdef _HAVE_SIN_LEN
598 	sin.sin_len = sizeof(sin);
599 #endif
600 	sin.sin_family = AF_INET;
601 	sin.sin_port = htons(RIP_PORT);
602 	sin.sin_addr.s_addr = addr;
603 	if (bind(s, (struct sockaddr *)&sin,sizeof(sin)) < 0) {
604 		if (serious)
605 			BADERR(errno != EADDRINUSE, "bind(rip_sock)");
606 		return -1;
607 	}
608 	fix_sock(s,"rip_sock");
609 
610 	ttl = 1;
611 	if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL,
612 		       &ttl, sizeof(ttl)) < 0)
613 		DBGERR(1,"rip_sock setsockopt(IP_MULTICAST_TTL)");
614 
615 	return s;
616 }
617 
618 
619 /* turn off main RIP socket */
620 void
621 rip_off(void)
622 {
623 	struct interface *ifp;
624 	register naddr addr;
625 
626 
627 	if (rip_sock >= 0 && !mhome) {
628 		trace_act("turn off RIP\n");
629 
630 		(void)close(rip_sock);
631 		rip_sock = -1;
632 
633 		/* get non-broadcast sockets to listen to queries.
634 		 */
635 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
636 			if (ifp->int_rip_sock < 0
637 			    && !(ifp->int_state & IS_ALIAS)) {
638 				addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
639 					? ifp->int_dstaddr
640 					: ifp->int_addr);
641 				ifp->int_rip_sock = get_rip_sock(addr, 0);
642 			}
643 		}
644 
645 		fix_select();
646 
647 		age(0);
648 	}
649 }
650 
651 
652 /* turn on RIP multicast input via an interface
653  */
654 static void
655 rip_mcast_on(struct interface *ifp)
656 {
657 	struct ip_mreq m;
658 
659 	if (!IS_RIP_IN_OFF(ifp->int_state)
660 	    && (ifp->int_if_flags & IFF_MULTICAST)
661 #ifdef MCAST_PPP_BUG
662 	    && !(ifp->int_if_flags & IFF_POINTOPOINT)
663 #endif
664 	    && !(ifp->int_state & IS_ALIAS)) {
665 		m.imr_multiaddr.s_addr = htonl(INADDR_RIP_GROUP);
666 		m.imr_interface.s_addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
667 					  ? ifp->int_dstaddr
668 					  : ifp->int_addr);
669 		if (setsockopt(rip_sock,IPPROTO_IP, IP_ADD_MEMBERSHIP,
670 			       &m, sizeof(m)) < 0)
671 			LOGERR("setsockopt(IP_ADD_MEMBERSHIP RIP)");
672 	}
673 }
674 
675 
676 /* Prepare socket used for RIP.
677  */
678 void
679 rip_on(struct interface *ifp)
680 {
681 	/* If the main RIP socket is already alive, only start receiving
682 	 * multicasts for this interface.
683 	 */
684 	if (rip_sock >= 0) {
685 		if (ifp != 0)
686 			rip_mcast_on(ifp);
687 		return;
688 	}
689 
690 	/* If the main RIP socket is off, and it makes sense to turn it on,
691 	 * turn it on for all of the interfaces.
692 	 */
693 	if (rip_interfaces > 0 && !rdisc_ok) {
694 		trace_act("turn on RIP\n");
695 
696 		/* Close all of the query sockets so that we can open
697 		 * the main socket.  SO_REUSEPORT is not a solution,
698 		 * since that would let two daemons bind to the broadcast
699 		 * socket.
700 		 */
701 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
702 			if (ifp->int_rip_sock >= 0) {
703 				(void)close(ifp->int_rip_sock);
704 				ifp->int_rip_sock = -1;
705 			}
706 		}
707 
708 		rip_sock = get_rip_sock(INADDR_ANY, 1);
709 		rip_sock_mcast = 0;
710 
711 		/* Do not advertise anything until we have heard something
712 		 */
713 		if (next_bcast.tv_sec < now.tv_sec+MIN_WAITTIME)
714 			next_bcast.tv_sec = now.tv_sec+MIN_WAITTIME;
715 
716 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
717 			if (!IS_RIP_IN_OFF(ifp->int_state))
718 				ifp->int_state &= ~IS_RIP_QUERIED;
719 			rip_mcast_on(ifp);
720 		}
721 
722 		ifinit_timer.tv_sec = now.tv_sec;
723 
724 		fix_select();
725 
726 	} else if (ifp != 0
727 		   && ifp->int_rip_sock < 0
728 		   && !(ifp->int_state & IS_ALIAS)) {
729 		/* RIP is off, so ensure there are sockets on which
730 		 * to listen for queries.
731 		 */
732 		ifp->int_rip_sock = get_rip_sock(ifp->int_addr, 0);
733 
734 		fix_select();
735 	}
736 }
737 
738 
739 /* die if malloc(3) fails
740  */
741 void *
742 rtmalloc(size_t size,
743 	 char *msg)
744 {
745 	void *p = malloc(size);
746 	if (p == 0)
747 		logbad(1,"malloc() failed in %s", msg);
748 	return p;
749 }
750 
751 
752 /* get a random instant in an interval
753  */
754 void
755 intvl_random(struct timeval *tp,	/* put value here */
756 	     u_long lo,			/* value is after this second */
757 	     u_long hi)			/* and before this */
758 {
759 	tp->tv_sec = (time_t)(hi == lo
760 			      ? lo
761 			      : (lo + random() % ((hi - lo))));
762 	tp->tv_usec = random() % 1000000;
763 }
764 
765 
766 void
767 timevaladd(struct timeval *t1,
768 	   struct timeval *t2)
769 {
770 
771 	t1->tv_sec += t2->tv_sec;
772 	if ((t1->tv_usec += t2->tv_usec) > 1000000) {
773 		t1->tv_sec++;
774 		t1->tv_usec -= 1000000;
775 	}
776 }
777 
778 
779 /* t1 = t2 - t3
780  */
781 static void
782 timevalsub(struct timeval *t1,
783 	   struct timeval *t2,
784 	   struct timeval *t3)
785 {
786 	t1->tv_sec = t2->tv_sec - t3->tv_sec;
787 	if ((t1->tv_usec = t2->tv_usec - t3->tv_usec) < 0) {
788 		t1->tv_sec--;
789 		t1->tv_usec += 1000000;
790 	}
791 }
792 
793 
794 void
795 msglog(char *p, ...)
796 {
797 	va_list args;
798 
799 	trace_flush();
800 
801 	va_start(args, p);
802 	vsyslog(LOG_ERR, p, args);
803 
804 	if (ftrace != 0) {
805 		if (ftrace == stdout)
806 			(void)fputs("routed: ", ftrace);
807 		(void)vfprintf(ftrace, p, args);
808 		(void)fputc('\n', ftrace);
809 	}
810 }
811 
812 
813 void
814 logbad(int dump, char *p, ...)
815 {
816 	va_list args;
817 
818 	trace_flush();
819 
820 	va_start(args, p);
821 	vsyslog(LOG_ERR, p, args);
822 
823 	(void)fputs("routed: ", stderr);
824 	(void)vfprintf(stderr, p, args);
825 	(void)fputs("; giving up\n",stderr);
826 	(void)fflush(stderr);
827 
828 	if (dump)
829 		abort();
830 	exit(1);
831 }
832