xref: /freebsd/sbin/routed/main.c (revision 2f02600abfddfc4e9f20dd384a2e729b451e16bd)
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  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  */
31 
32 #include "defs.h"
33 #include "pathnames.h"
34 #ifdef sgi
35 #include "math.h"
36 #endif
37 #include <signal.h>
38 #include <fcntl.h>
39 #include <sys/file.h>
40 
41 __COPYRIGHT("@(#) Copyright (c) 1983, 1988, 1993 "
42 	    "The Regents of the University of California."
43 	    "  All rights reserved.");
44 #ifdef __NetBSD__
45 __RCSID("$NetBSD$");
46 #include <util.h>
47 #elif defined(__FreeBSD__)
48 __RCSID("$FreeBSD$");
49 #else
50 __RCSID("$Revision: 2.31 $");
51 #ident "$Revision: 2.31 $"
52 #endif
53 
54 pid_t	mypid;
55 
56 naddr	myaddr;				/* system address */
57 static char myname[MAXHOSTNAMELEN+1];
58 
59 static int verbose;
60 
61 int	supplier;			/* supply or broadcast updates */
62 int	supplier_set;
63 static int ipforwarding = 1;		/* kernel forwarding on */
64 
65 static int default_gateway;		/* 1=advertise default */
66 static int background = 1;
67 int	ridhosts;			/* 1=reduce host routes */
68 int	mhome;				/* 1=want multi-homed host route */
69 int	advertise_mhome;		/* 1=must continue advertising it */
70 int	auth_ok = 1;			/* 1=ignore auth if we do not care */
71 
72 struct timeval epoch;			/* when started */
73 struct timeval clk;
74 static struct timeval prev_clk;
75 static int usec_fudge;
76 struct timeval now;			/* current idea of time */
77 time_t	now_stale;
78 time_t	now_expire;
79 time_t	now_garbage;
80 
81 static struct timeval next_bcast;	/* next general broadcast */
82 struct timeval no_flash = {		/* inhibit flash update */
83 	EPOCH+SUPPLY_INTERVAL, 0
84 };
85 
86 static struct timeval flush_kern_timer;
87 
88 static fd_set fdbits;
89 static int sock_max;
90 int	rip_sock = -1;			/* RIP socket */
91 const struct interface *rip_sock_mcast;	/* current multicast interface */
92 int	rt_sock;			/* routing socket */
93 int	rt_sock_seqno;
94 
95 
96 static  int get_rip_sock(naddr, int);
97 static void timevalsub(struct timeval *, struct timeval *, struct timeval *);
98 static void sigalrm(int s UNUSED);
99 static void sigterm(int sig);
100 
101 int
102 main(int argc,
103      char *argv[])
104 {
105 	int n, mib[4], off;
106 	size_t len;
107 	char *p, *q;
108 	const char *cp;
109 	struct timeval wtime, t2;
110 	time_t dt;
111 	fd_set ibits;
112 	naddr p_net, p_mask;
113 	struct interface *ifp;
114 	struct parm parm;
115 	char *tracename = 0;
116 
117 
118 	/* Some shells are badly broken and send SIGHUP to backgrounded
119 	 * processes.
120 	 */
121 	signal(SIGHUP, SIG_IGN);
122 
123 	openlog("routed", LOG_PID, LOG_DAEMON);
124 	ftrace = stdout;
125 
126 	gettimeofday(&clk, 0);
127 	prev_clk = clk;
128 	epoch = clk;
129 	epoch.tv_sec -= EPOCH;
130 	now.tv_sec = EPOCH;
131 	now_stale = EPOCH - STALE_TIME;
132 	now_expire = EPOCH - EXPIRE_TIME;
133 	now_garbage = EPOCH - GARBAGE_TIME;
134 	wtime.tv_sec = 0;
135 
136 	(void)gethostname(myname, sizeof(myname)-1);
137 	(void)gethost(myname, &myaddr);
138 
139 	while ((n = getopt(argc, argv, "sqdghmAtvT:F:P:")) != -1) {
140 		switch (n) {
141 		case 's':
142 			supplier = 1;
143 			supplier_set = 1;
144 			break;
145 
146 		case 'q':
147 			supplier = 0;
148 			supplier_set = 1;
149 			break;
150 
151 		case 'd':
152 			background = 0;
153 			break;
154 
155 		case 'g':
156 			memset(&parm, 0, sizeof(parm));
157 			parm.parm_d_metric = 1;
158 			cp = check_parms(&parm);
159 			if (cp != 0)
160 				msglog("bad -g: %s", cp);
161 			else
162 				default_gateway = 1;
163 			break;
164 
165 		case 'h':		/* suppress extra host routes */
166 			ridhosts = 1;
167 			break;
168 
169 		case 'm':		/* advertise host route */
170 			mhome = 1;	/* on multi-homed hosts */
171 			break;
172 
173 		case 'A':
174 			/* Ignore authentication if we do not care.
175 			 * Crazy as it is, that is what RFC 1723 requires.
176 			 */
177 			auth_ok = 0;
178 			break;
179 
180 		case 't':
181 			new_tracelevel++;
182 			break;
183 
184 		case 'T':
185 			tracename = optarg;
186 			break;
187 
188 		case 'F':		/* minimal routes for SLIP */
189 			n = FAKE_METRIC;
190 			p = strchr(optarg,',');
191 			if (p && *p != '\0') {
192 				n = (int)strtoul(p+1, &q, 0);
193 				if (*q == '\0'
194 				    && n <= HOPCNT_INFINITY-1
195 				    && n >= 1)
196 					*p = '\0';
197 			}
198 			if (!getnet(optarg, &p_net, &p_mask)) {
199 				msglog("bad network; \"-F %s\"",
200 				       optarg);
201 				break;
202 			}
203 			memset(&parm, 0, sizeof(parm));
204 			parm.parm_net = p_net;
205 			parm.parm_mask = p_mask;
206 			parm.parm_d_metric = n;
207 			cp = check_parms(&parm);
208 			if (cp != 0)
209 				msglog("bad -F: %s", cp);
210 			break;
211 
212 		case 'P':
213 			/* handle arbitrary parameters.
214 			 */
215 			q = strdup(optarg);
216 			cp = parse_parms(q, 0);
217 			if (cp != 0)
218 				msglog("%s in \"-P %s\"", cp, optarg);
219 			free(q);
220 			break;
221 
222 		case 'v':
223 			/* display version */
224 			verbose++;
225 			msglog("version 2.31");
226 			break;
227 
228 		default:
229 			goto usage;
230 		}
231 	}
232 	argc -= optind;
233 	argv += optind;
234 
235 	if (tracename == 0 && argc >= 1) {
236 		tracename = *argv++;
237 		argc--;
238 	}
239 	if (tracename != 0 && tracename[0] == '\0')
240 		goto usage;
241 	if (argc != 0) {
242 usage:
243 		logbad(0, "usage: routed [-sqdghmAtv] [-T tracefile]"
244 		       " [-F net[,metric]] [-P parms]");
245 	}
246 	if (geteuid() != 0) {
247 		if (verbose)
248 			exit(0);
249 		logbad(0, "requires UID 0");
250 	}
251 
252 	mib[0] = CTL_NET;
253 	mib[1] = PF_INET;
254 	mib[2] = IPPROTO_IP;
255 	mib[3] = IPCTL_FORWARDING;
256 	len = sizeof(ipforwarding);
257 	if (sysctl(mib, 4, &ipforwarding, &len, 0, 0) < 0)
258 		LOGERR("sysctl(IPCTL_FORWARDING)");
259 
260 	if (!ipforwarding) {
261 		if (supplier)
262 			msglog("-s incompatible with ipforwarding=0");
263 		if (default_gateway) {
264 			msglog("-g incompatible with ipforwarding=0");
265 			default_gateway = 0;
266 		}
267 		supplier = 0;
268 		supplier_set = 1;
269 	}
270 	if (default_gateway) {
271 		if (supplier_set && !supplier) {
272 			msglog("-g and -q incompatible");
273 		} else {
274 			supplier = 1;
275 			supplier_set = 1;
276 		}
277 	}
278 
279 
280 	signal(SIGALRM, sigalrm);
281 	if (!background)
282 		signal(SIGHUP, sigterm);    /* SIGHUP fatal during debugging */
283 	signal(SIGTERM, sigterm);
284 	signal(SIGINT, sigterm);
285 	signal(SIGUSR1, sigtrace_on);
286 	signal(SIGUSR2, sigtrace_off);
287 
288 	/* get into the background */
289 #ifdef sgi
290 	if (0 > _daemonize(background ? 0 : (_DF_NOCHDIR|_DF_NOFORK),
291 			   STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO))
292 		BADERR(0, "_daemonize()");
293 #else
294 	if (background && daemon(0, 1) < 0)
295 		BADERR(0,"daemon()");
296 #endif
297 
298 #if defined(__NetBSD__)
299 	pidfile(0);
300 #endif
301 	mypid = getpid();
302 #ifdef __FreeBSD__
303 	srandomdev();
304 #else
305 	srandom((int)(clk.tv_sec ^ clk.tv_usec ^ mypid));
306 #endif
307 
308 	/* prepare socket connected to the kernel.
309 	 */
310 	rt_sock = socket(AF_ROUTE, SOCK_RAW, 0);
311 	if (rt_sock < 0)
312 		BADERR(1,"rt_sock = socket()");
313 	if (fcntl(rt_sock, F_SETFL, O_NONBLOCK) == -1)
314 		logbad(1, "fcntl(rt_sock) O_NONBLOCK: %s", strerror(errno));
315 	off = 0;
316 	if (setsockopt(rt_sock, SOL_SOCKET,SO_USELOOPBACK,
317 		       &off,sizeof(off)) < 0)
318 		LOGERR("setsockopt(SO_USELOOPBACK,0)");
319 
320 	fix_select();
321 
322 
323 	if (tracename != 0) {
324 		strncpy(inittracename, tracename, sizeof(inittracename)-1);
325 		set_tracefile(inittracename, "%s", -1);
326 	} else {
327 		tracelevel_msg("%s", -1);   /* turn on tracing to stdio */
328 	}
329 
330 	bufinit();
331 
332 	/* initialize radix tree */
333 	rtinit();
334 
335 	/* Pick a random part of the second for our output to minimize
336 	 * collisions.
337 	 *
338 	 * Start broadcasting after hearing from other routers, and
339 	 * at a random time so a bunch of systems do not get synchronized
340 	 * after a power failure.
341 	 */
342 	intvl_random(&next_bcast, EPOCH+MIN_WAITTIME, EPOCH+SUPPLY_INTERVAL);
343 	age_timer.tv_usec = next_bcast.tv_usec;
344 	age_timer.tv_sec = EPOCH+MIN_WAITTIME;
345 	rdisc_timer = next_bcast;
346 	ifinit_timer.tv_usec = next_bcast.tv_usec;
347 
348 	/* Collect an initial view of the world by checking the interface
349 	 * configuration and the kludge file.
350 	 */
351 	gwkludge();
352 	ifinit();
353 
354 	/* Ask for routes */
355 	rip_query();
356 	rdisc_sol();
357 
358 	/* Now turn off stdio if not tracing */
359 	if (new_tracelevel == 0)
360 		trace_close(background);
361 
362 	/* Loop forever, listening and broadcasting.
363 	 */
364 	for (;;) {
365 		prev_clk = clk;
366 		gettimeofday(&clk, 0);
367 		if (prev_clk.tv_sec == clk.tv_sec
368 		    && prev_clk.tv_usec == clk.tv_usec+usec_fudge) {
369 			/* Much of `routed` depends on time always advancing.
370 			 * On systems that do not guarantee that gettimeofday()
371 			 * produces unique timestamps even if called within
372 			 * a single tick, use trickery like that in classic
373 			 * BSD kernels.
374 			 */
375 			clk.tv_usec += ++usec_fudge;
376 
377 		} else {
378 			usec_fudge = 0;
379 
380 			timevalsub(&t2, &clk, &prev_clk);
381 			if (t2.tv_sec < 0
382 			    || t2.tv_sec > wtime.tv_sec + 5) {
383 				/* Deal with time changes before other
384 				 * housekeeping to keep everything straight.
385 				 */
386 				dt = t2.tv_sec;
387 				if (dt > 0)
388 					dt -= wtime.tv_sec;
389 				trace_act("time changed by %d sec", (int)dt);
390 				epoch.tv_sec += dt;
391 			}
392 		}
393 		timevalsub(&now, &clk, &epoch);
394 		now_stale = now.tv_sec - STALE_TIME;
395 		now_expire = now.tv_sec - EXPIRE_TIME;
396 		now_garbage = now.tv_sec - GARBAGE_TIME;
397 
398 		/* deal with signals that should affect tracing */
399 		set_tracelevel();
400 
401 		if (stopint != 0) {
402 			rip_bcast(0);
403 			rdisc_adv();
404 			trace_off("exiting with signal %d", stopint);
405 			exit(stopint | 128);
406 		}
407 
408 		/* look for new or dead interfaces */
409 		timevalsub(&wtime, &ifinit_timer, &now);
410 		if (wtime.tv_sec <= 0) {
411 			wtime.tv_sec = 0;
412 			ifinit();
413 			rip_query();
414 			continue;
415 		}
416 
417 		/* Check the kernel table occasionally for mysteriously
418 		 * evaporated routes
419 		 */
420 		timevalsub(&t2, &flush_kern_timer, &now);
421 		if (t2.tv_sec <= 0) {
422 			flush_kern();
423 			flush_kern_timer.tv_sec = (now.tv_sec
424 						   + CHECK_QUIET_INTERVAL);
425 			continue;
426 		}
427 		if (timercmp(&t2, &wtime, <))
428 			wtime = t2;
429 
430 		/* If it is time, then broadcast our routes.
431 		 */
432 		if (supplier || advertise_mhome) {
433 			timevalsub(&t2, &next_bcast, &now);
434 			if (t2.tv_sec <= 0) {
435 				/* Synchronize the aging and broadcast
436 				 * timers to minimize awakenings
437 				 */
438 				age(0);
439 
440 				rip_bcast(0);
441 
442 				/* It is desirable to send routing updates
443 				 * regularly.  So schedule the next update
444 				 * 30 seconds after the previous one was
445 				 * scheduled, instead of 30 seconds after
446 				 * the previous update was finished.
447 				 * Even if we just started after discovering
448 				 * a 2nd interface or were otherwise delayed,
449 				 * pick a 30-second anniversary of the
450 				 * original broadcast time.
451 				 */
452 				n = 1 + (0-t2.tv_sec)/SUPPLY_INTERVAL;
453 				next_bcast.tv_sec += n*SUPPLY_INTERVAL;
454 
455 				continue;
456 			}
457 
458 			if (timercmp(&t2, &wtime, <))
459 				wtime = t2;
460 		}
461 
462 		/* If we need a flash update, either do it now or
463 		 * set the delay to end when it is time.
464 		 *
465 		 * If we are within MIN_WAITTIME seconds of a full update,
466 		 * do not bother.
467 		 */
468 		if (need_flash
469 		    && supplier
470 		    && no_flash.tv_sec+MIN_WAITTIME < next_bcast.tv_sec) {
471 			/* accurate to the millisecond */
472 			if (!timercmp(&no_flash, &now, >))
473 				rip_bcast(1);
474 			timevalsub(&t2, &no_flash, &now);
475 			if (timercmp(&t2, &wtime, <))
476 				wtime = t2;
477 		}
478 
479 		/* trigger the main aging timer.
480 		 */
481 		timevalsub(&t2, &age_timer, &now);
482 		if (t2.tv_sec <= 0) {
483 			age(0);
484 			continue;
485 		}
486 		if (timercmp(&t2, &wtime, <))
487 			wtime = t2;
488 
489 		/* update the kernel routing table
490 		 */
491 		timevalsub(&t2, &need_kern, &now);
492 		if (t2.tv_sec <= 0) {
493 			age(0);
494 			continue;
495 		}
496 		if (timercmp(&t2, &wtime, <))
497 			wtime = t2;
498 
499 		/* take care of router discovery,
500 		 * but do it in the correct the millisecond
501 		 */
502 		if (!timercmp(&rdisc_timer, &now, >)) {
503 			rdisc_age(0);
504 			continue;
505 		}
506 		timevalsub(&t2, &rdisc_timer, &now);
507 		if (timercmp(&t2, &wtime, <))
508 			wtime = t2;
509 
510 
511 		/* wait for input or a timer to expire.
512 		 */
513 		trace_flush();
514 		ibits = fdbits;
515 		n = select(sock_max, &ibits, 0, 0, &wtime);
516 		if (n <= 0) {
517 			if (n < 0 && errno != EINTR && errno != EAGAIN)
518 				BADERR(1,"select");
519 			continue;
520 		}
521 
522 		if (FD_ISSET(rt_sock, &ibits)) {
523 			read_rt();
524 			n--;
525 		}
526 		if (rdisc_sock >= 0 && FD_ISSET(rdisc_sock, &ibits)) {
527 			read_d();
528 			n--;
529 		}
530 		if (rip_sock >= 0 && FD_ISSET(rip_sock, &ibits)) {
531 			read_rip(rip_sock, 0);
532 			n--;
533 		}
534 
535 		LIST_FOREACH(ifp, &ifnet, int_list) {
536 			if (n <= 0)
537 				break;
538 			if (ifp->int_rip_sock >= 0
539 			    && FD_ISSET(ifp->int_rip_sock, &ibits)) {
540 				read_rip(ifp->int_rip_sock, ifp);
541 				n--;
542 			}
543 		}
544 	}
545 }
546 
547 
548 /* ARGSUSED */
549 static void
550 sigalrm(int s UNUSED)
551 {
552 	/* Historically, SIGALRM would cause the daemon to check for
553 	 * new and broken interfaces.
554 	 */
555 	ifinit_timer.tv_sec = now.tv_sec;
556 	trace_act("SIGALRM");
557 }
558 
559 
560 /* watch for fatal signals */
561 static void
562 sigterm(int sig)
563 {
564 	stopint = sig;
565 	(void)signal(sig, SIG_DFL);	/* catch it only once */
566 }
567 
568 
569 void
570 fix_select(void)
571 {
572 	struct interface *ifp;
573 
574 
575 	FD_ZERO(&fdbits);
576 	sock_max = 0;
577 
578 	FD_SET(rt_sock, &fdbits);
579 	if (sock_max <= rt_sock)
580 		sock_max = rt_sock+1;
581 	if (rip_sock >= 0) {
582 		FD_SET(rip_sock, &fdbits);
583 		if (sock_max <= rip_sock)
584 			sock_max = rip_sock+1;
585 	}
586 	LIST_FOREACH(ifp, &ifnet, int_list) {
587 		if (ifp->int_rip_sock >= 0) {
588 			FD_SET(ifp->int_rip_sock, &fdbits);
589 			if (sock_max <= ifp->int_rip_sock)
590 				sock_max = ifp->int_rip_sock+1;
591 		}
592 	}
593 	if (rdisc_sock >= 0) {
594 		FD_SET(rdisc_sock, &fdbits);
595 		if (sock_max <= rdisc_sock)
596 			sock_max = rdisc_sock+1;
597 	}
598 }
599 
600 
601 void
602 fix_sock(int sock,
603 	 const char *name)
604 {
605 	int on;
606 #define MIN_SOCKBUF (4*1024)
607 	static int rbuf;
608 
609 	if (fcntl(sock, F_SETFL, O_NONBLOCK) == -1)
610 		logbad(1, "fcntl(%s) O_NONBLOCK: %s",
611 		       name, strerror(errno));
612 	on = 1;
613 	if (setsockopt(sock, SOL_SOCKET,SO_BROADCAST, &on,sizeof(on)) < 0)
614 		msglog("setsockopt(%s,SO_BROADCAST): %s",
615 		       name, strerror(errno));
616 #ifdef USE_PASSIFNAME
617 	on = 1;
618 	if (setsockopt(sock, SOL_SOCKET, SO_PASSIFNAME, &on,sizeof(on)) < 0)
619 		msglog("setsockopt(%s,SO_PASSIFNAME): %s",
620 		       name, strerror(errno));
621 #endif
622 
623 	if (rbuf >= MIN_SOCKBUF) {
624 		if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
625 			       &rbuf, sizeof(rbuf)) < 0)
626 			msglog("setsockopt(%s,SO_RCVBUF=%d): %s",
627 			       name, rbuf, strerror(errno));
628 	} else {
629 		for (rbuf = 60*1024; ; rbuf -= 4096) {
630 			if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
631 				       &rbuf, sizeof(rbuf)) == 0) {
632 				trace_act("RCVBUF=%d", rbuf);
633 				break;
634 			}
635 			if (rbuf < MIN_SOCKBUF) {
636 				msglog("setsockopt(%s,SO_RCVBUF = %d): %s",
637 				       name, rbuf, strerror(errno));
638 				break;
639 			}
640 		}
641 	}
642 }
643 
644 
645 /* get a rip socket
646  */
647 static int				/* <0 or file descriptor */
648 get_rip_sock(naddr addr,
649 	     int serious)		/* 1=failure to bind is serious */
650 {
651 	struct sockaddr_in rsin;
652 	unsigned char ttl;
653 	int s;
654 
655 
656 	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
657 		BADERR(1,"rip_sock = socket()");
658 
659 	memset(&rsin, 0, sizeof(rsin));
660 #ifdef _HAVE_SIN_LEN
661 	rsin.sin_len = sizeof(rsin);
662 #endif
663 	rsin.sin_family = AF_INET;
664 	rsin.sin_port = htons(RIP_PORT);
665 	rsin.sin_addr.s_addr = addr;
666 	if (bind(s, (struct sockaddr *)&rsin, sizeof(rsin)) < 0) {
667 		if (serious)
668 			BADERR(errno != EADDRINUSE, "bind(rip_sock)");
669 		return -1;
670 	}
671 	fix_sock(s,"rip_sock");
672 
673 	ttl = 1;
674 	if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL,
675 		       &ttl, sizeof(ttl)) < 0)
676 		DBGERR(1,"rip_sock setsockopt(IP_MULTICAST_TTL)");
677 
678 	return s;
679 }
680 
681 
682 /* turn off main RIP socket */
683 void
684 rip_off(void)
685 {
686 	struct interface *ifp;
687 	naddr addr;
688 
689 
690 	if (rip_sock >= 0 && !mhome) {
691 		trace_act("turn off RIP");
692 
693 		(void)close(rip_sock);
694 		rip_sock = -1;
695 
696 		/* get non-broadcast sockets to listen to queries.
697 		 */
698 		LIST_FOREACH(ifp, &ifnet, int_list) {
699 			if (ifp->int_state & IS_REMOTE)
700 				continue;
701 			if (ifp->int_rip_sock < 0) {
702 				addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
703 					? ifp->int_dstaddr
704 					: ifp->int_addr);
705 				ifp->int_rip_sock = get_rip_sock(addr, 0);
706 			}
707 		}
708 
709 		fix_select();
710 
711 		age(0);
712 	}
713 }
714 
715 
716 /* turn on RIP multicast input via an interface
717  */
718 static void
719 rip_mcast_on(struct interface *ifp)
720 {
721 	struct group_req gr;
722 	struct sockaddr_in *sin;
723 
724 	if (!IS_RIP_IN_OFF(ifp->int_state)
725 	    && (ifp->int_if_flags & IFF_MULTICAST)
726 	    && !(ifp->int_state & IS_ALIAS)) {
727 		memset(&gr, 0, sizeof(gr));
728 		gr.gr_interface = ifp->int_index;
729 		sin = (struct sockaddr_in *)&gr.gr_group;
730 		sin->sin_family = AF_INET;
731 #ifdef _HAVE_SIN_LEN
732 		sin->sin_len = sizeof(struct sockaddr_in);
733 #endif
734 		sin->sin_addr.s_addr = htonl(INADDR_RIP_GROUP);
735 		if (setsockopt(rip_sock, IPPROTO_IP, MCAST_JOIN_GROUP,
736 			       &gr, sizeof(gr)) < 0)
737 			LOGERR("setsockopt(MCAST_JOIN_GROUP RIP)");
738 	}
739 }
740 
741 
742 /* Prepare socket used for RIP.
743  */
744 void
745 rip_on(struct interface *ifp)
746 {
747 	/* If the main RIP socket is already alive, only start receiving
748 	 * multicasts for this interface.
749 	 */
750 	if (rip_sock >= 0) {
751 		if (ifp != 0)
752 			rip_mcast_on(ifp);
753 		return;
754 	}
755 
756 	/* If the main RIP socket is off and it makes sense to turn it on,
757 	 * then turn it on for all of the interfaces.
758 	 * It makes sense if either router discovery is off, or if
759 	 * router discover is on and at most one interface is doing RIP.
760 	 */
761 	if (rip_interfaces > 0 && (!rdisc_ok || rip_interfaces > 1)) {
762 		trace_act("turn on RIP");
763 
764 		/* Close all of the query sockets so that we can open
765 		 * the main socket.  SO_REUSEPORT is not a solution,
766 		 * since that would let two daemons bind to the broadcast
767 		 * socket.
768 		 */
769 		LIST_FOREACH(ifp, &ifnet, int_list) {
770 			if (ifp->int_rip_sock >= 0) {
771 				(void)close(ifp->int_rip_sock);
772 				ifp->int_rip_sock = -1;
773 			}
774 		}
775 
776 		rip_sock = get_rip_sock(INADDR_ANY, 1);
777 		rip_sock_mcast = 0;
778 
779 		/* Do not advertise anything until we have heard something
780 		 */
781 		if (next_bcast.tv_sec < now.tv_sec+MIN_WAITTIME)
782 			next_bcast.tv_sec = now.tv_sec+MIN_WAITTIME;
783 
784 		LIST_FOREACH(ifp, &ifnet, int_list) {
785 			ifp->int_query_time = NEVER;
786 			rip_mcast_on(ifp);
787 		}
788 		ifinit_timer.tv_sec = now.tv_sec;
789 
790 	} else if (ifp != 0
791 		   && !(ifp->int_state & IS_REMOTE)
792 		   && ifp->int_rip_sock < 0) {
793 		/* RIP is off, so ensure there are sockets on which
794 		 * to listen for queries.
795 		 */
796 		ifp->int_rip_sock = get_rip_sock(ifp->int_addr, 0);
797 	}
798 
799 	fix_select();
800 }
801 
802 
803 /* die if malloc(3) fails
804  */
805 void *
806 rtmalloc(size_t size,
807 	 const char *msg)
808 {
809 	void *p = malloc(size);
810 	if (p == 0)
811 		logbad(1,"malloc(%lu) failed in %s", (u_long)size, msg);
812 	return p;
813 }
814 
815 
816 /* get a random instant in an interval
817  */
818 void
819 intvl_random(struct timeval *tp,	/* put value here */
820 	     u_long lo,			/* value is after this second */
821 	     u_long hi)			/* and before this */
822 {
823 	tp->tv_sec = (time_t)(hi == lo
824 			      ? lo
825 			      : (lo + random() % ((hi - lo))));
826 	tp->tv_usec = random() % 1000000;
827 }
828 
829 
830 void
831 timevaladd(struct timeval *t1,
832 	   struct timeval *t2)
833 {
834 
835 	t1->tv_sec += t2->tv_sec;
836 	if ((t1->tv_usec += t2->tv_usec) >= 1000000) {
837 		t1->tv_sec++;
838 		t1->tv_usec -= 1000000;
839 	}
840 }
841 
842 
843 /* t1 = t2 - t3
844  */
845 static void
846 timevalsub(struct timeval *t1,
847 	   struct timeval *t2,
848 	   struct timeval *t3)
849 {
850 	t1->tv_sec = t2->tv_sec - t3->tv_sec;
851 	if ((t1->tv_usec = t2->tv_usec - t3->tv_usec) < 0) {
852 		t1->tv_sec--;
853 		t1->tv_usec += 1000000;
854 	}
855 }
856 
857 
858 /* put a message into the system log
859  */
860 void
861 msglog(const char *p, ...)
862 {
863 	va_list args;
864 
865 	trace_flush();
866 
867 	va_start(args, p);
868 	vsyslog(LOG_ERR, p, args);
869 	va_end(args);
870 	if (ftrace != 0) {
871 		if (ftrace == stdout)
872 			(void)fputs("routed: ", ftrace);
873 		va_start(args, p);
874 		(void)vfprintf(ftrace, p, args);
875 		va_end(args);
876 		(void)fputc('\n', ftrace);
877 	}
878 }
879 
880 
881 /* Put a message about a bad system into the system log if
882  * we have not complained about it recently.
883  *
884  * It is desirable to complain about all bad systems, but not too often.
885  * In the worst case, it is not practical to keep track of all bad systems.
886  * For example, there can be many systems with the wrong password.
887  */
888 void
889 msglim(struct msg_limit *lim, naddr addr, const char *p, ...)
890 {
891 	va_list args;
892 	int i;
893 	struct msg_sub *ms1, *ms;
894 	const char *p1;
895 
896 	/* look for the oldest slot in the table
897 	 * or the slot for the bad router.
898 	 */
899 	ms = ms1 = lim->subs;
900 	for (i = MSG_SUBJECT_N; ; i--, ms1++) {
901 		if (i == 0) {
902 			/* Reuse a slot at most once every 10 minutes.
903 			 */
904 			if (lim->reuse > now.tv_sec) {
905 				ms = 0;
906 			} else {
907 				ms = ms1;
908 				lim->reuse = now.tv_sec + 10*60;
909 			}
910 			break;
911 		}
912 		if (ms->addr == addr) {
913 			/* Repeat a complaint about a given system at
914 			 * most once an hour.
915 			 */
916 			if (ms->until > now.tv_sec)
917 				ms = 0;
918 			break;
919 		}
920 		if (ms->until < ms1->until)
921 			ms = ms1;
922 	}
923 	if (ms != 0) {
924 		ms->addr = addr;
925 		ms->until = now.tv_sec + 60*60;	/* 60 minutes */
926 
927 		trace_flush();
928 		for (p1 = p; *p1 == ' '; p1++)
929 			continue;
930 		va_start(args, p);
931 		vsyslog(LOG_ERR, p1, args);
932 		va_end(args);
933 	}
934 
935 	/* always display the message if tracing */
936 	if (ftrace != 0) {
937 		va_start(args, p);
938 		(void)vfprintf(ftrace, p, args);
939 		va_end(args);
940 		(void)fputc('\n', ftrace);
941 	}
942 }
943 
944 
945 void
946 logbad(int dump, const char *p, ...)
947 {
948 	va_list args;
949 
950 	trace_flush();
951 
952 	va_start(args, p);
953 	vsyslog(LOG_ERR, p, args);
954 	va_end(args);
955 	(void)fputs("routed: ", stderr);
956 	va_start(args, p);
957 	(void)vfprintf(stderr, p, args);
958 	va_end(args);
959 	(void)fputs("; giving up\n",stderr);
960 	(void)fflush(stderr);
961 
962 	if (dump)
963 		abort();
964 	exit(1);
965 }
966