xref: /freebsd/sbin/routed/main.c (revision 18849b5da0c5eaa88500b457be05b038813b51b1)
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 int	insecure;			/* Reply to special queries or not */
72 
73 struct timeval epoch;			/* when started */
74 struct timeval clk;
75 static struct timeval prev_clk;
76 static int usec_fudge;
77 struct timeval now;			/* current idea of time */
78 time_t	now_stale;
79 time_t	now_expire;
80 time_t	now_garbage;
81 
82 static struct timeval next_bcast;	/* next general broadcast */
83 struct timeval no_flash = {		/* inhibit flash update */
84 	EPOCH+SUPPLY_INTERVAL, 0
85 };
86 
87 static struct timeval flush_kern_timer;
88 
89 static fd_set fdbits;
90 static int sock_max;
91 int	rip_sock = -1;			/* RIP socket */
92 const struct interface *rip_sock_mcast;	/* current multicast interface */
93 int	rt_sock;			/* routing socket */
94 int	rt_sock_seqno;
95 
96 
97 static  int get_rip_sock(naddr, int);
98 static void timevalsub(struct timeval *, struct timeval *, struct timeval *);
99 static void sigalrm(int s UNUSED);
100 static void sigterm(int sig);
101 
102 int
103 main(int argc,
104      char *argv[])
105 {
106 	int n, mib[4], off;
107 	size_t len;
108 	char *p, *q;
109 	const char *cp;
110 	struct timeval wtime, t2;
111 	time_t dt;
112 	fd_set ibits;
113 	naddr p_net, p_mask;
114 	struct interface *ifp;
115 	struct parm parm;
116 	char *tracename = 0;
117 
118 
119 	/* Some shells are badly broken and send SIGHUP to backgrounded
120 	 * processes.
121 	 */
122 	signal(SIGHUP, SIG_IGN);
123 
124 	openlog("routed", LOG_PID, LOG_DAEMON);
125 	ftrace = stdout;
126 
127 	gettimeofday(&clk, 0);
128 	prev_clk = clk;
129 	epoch = clk;
130 	epoch.tv_sec -= EPOCH;
131 	now.tv_sec = EPOCH;
132 	now_stale = EPOCH - STALE_TIME;
133 	now_expire = EPOCH - EXPIRE_TIME;
134 	now_garbage = EPOCH - GARBAGE_TIME;
135 	wtime.tv_sec = 0;
136 
137 	(void)gethostname(myname, sizeof(myname)-1);
138 	(void)gethost(myname, &myaddr);
139 
140 	while ((n = getopt(argc, argv, "isqdghmAtvT:F:P:")) != -1) {
141 		switch (n) {
142 		case 'i':
143 			insecure++;
144 			break;
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 2.31");
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[,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(0);
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 		strncpy(inittracename, tracename, sizeof(inittracename)-1);
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 occasionally 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 anniversary 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 		ibits = fdbits;
514 		n = select(sock_max, &ibits, 0, 0, &wtime);
515 		if (n <= 0) {
516 			if (n < 0 && errno != EINTR && errno != EAGAIN)
517 				BADERR(1,"select");
518 			continue;
519 		}
520 
521 		if (FD_ISSET(rt_sock, &ibits)) {
522 			read_rt();
523 			n--;
524 		}
525 		if (rdisc_sock >= 0 && FD_ISSET(rdisc_sock, &ibits)) {
526 			read_d();
527 			n--;
528 		}
529 		if (rip_sock >= 0 && FD_ISSET(rip_sock, &ibits)) {
530 			read_rip(rip_sock, 0);
531 			n--;
532 		}
533 
534 		LIST_FOREACH(ifp, &ifnet, int_list) {
535 			if (n <= 0)
536 				break;
537 			if (ifp->int_rip_sock >= 0
538 			    && FD_ISSET(ifp->int_rip_sock, &ibits)) {
539 				read_rip(ifp->int_rip_sock, ifp);
540 				n--;
541 			}
542 		}
543 	}
544 }
545 
546 
547 /* ARGSUSED */
548 static void
549 sigalrm(int s UNUSED)
550 {
551 	/* Historically, SIGALRM would cause the daemon to check for
552 	 * new and broken interfaces.
553 	 */
554 	ifinit_timer.tv_sec = now.tv_sec;
555 	trace_act("SIGALRM");
556 }
557 
558 
559 /* watch for fatal signals */
560 static void
561 sigterm(int sig)
562 {
563 	stopint = sig;
564 	(void)signal(sig, SIG_DFL);	/* catch it only once */
565 }
566 
567 
568 void
569 fix_select(void)
570 {
571 	struct interface *ifp;
572 
573 
574 	FD_ZERO(&fdbits);
575 	sock_max = 0;
576 
577 	FD_SET(rt_sock, &fdbits);
578 	if (sock_max <= rt_sock)
579 		sock_max = rt_sock+1;
580 	if (rip_sock >= 0) {
581 		FD_SET(rip_sock, &fdbits);
582 		if (sock_max <= rip_sock)
583 			sock_max = rip_sock+1;
584 	}
585 	LIST_FOREACH(ifp, &ifnet, int_list) {
586 		if (ifp->int_rip_sock >= 0) {
587 			FD_SET(ifp->int_rip_sock, &fdbits);
588 			if (sock_max <= ifp->int_rip_sock)
589 				sock_max = ifp->int_rip_sock+1;
590 		}
591 	}
592 	if (rdisc_sock >= 0) {
593 		FD_SET(rdisc_sock, &fdbits);
594 		if (sock_max <= rdisc_sock)
595 			sock_max = rdisc_sock+1;
596 	}
597 }
598 
599 
600 void
601 fix_sock(int sock,
602 	 const char *name)
603 {
604 	int on;
605 #define MIN_SOCKBUF (4*1024)
606 	static int rbuf;
607 
608 	if (fcntl(sock, F_SETFL, O_NONBLOCK) == -1)
609 		logbad(1, "fcntl(%s) O_NONBLOCK: %s",
610 		       name, strerror(errno));
611 	on = 1;
612 	if (setsockopt(sock, SOL_SOCKET,SO_BROADCAST, &on,sizeof(on)) < 0)
613 		msglog("setsockopt(%s,SO_BROADCAST): %s",
614 		       name, strerror(errno));
615 #ifdef USE_PASSIFNAME
616 	on = 1;
617 	if (setsockopt(sock, SOL_SOCKET, SO_PASSIFNAME, &on,sizeof(on)) < 0)
618 		msglog("setsockopt(%s,SO_PASSIFNAME): %s",
619 		       name, strerror(errno));
620 #endif
621 
622 	if (rbuf >= MIN_SOCKBUF) {
623 		if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
624 			       &rbuf, sizeof(rbuf)) < 0)
625 			msglog("setsockopt(%s,SO_RCVBUF=%d): %s",
626 			       name, rbuf, strerror(errno));
627 	} else {
628 		for (rbuf = 60*1024; ; rbuf -= 4096) {
629 			if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
630 				       &rbuf, sizeof(rbuf)) == 0) {
631 				trace_act("RCVBUF=%d", rbuf);
632 				break;
633 			}
634 			if (rbuf < MIN_SOCKBUF) {
635 				msglog("setsockopt(%s,SO_RCVBUF = %d): %s",
636 				       name, rbuf, strerror(errno));
637 				break;
638 			}
639 		}
640 	}
641 }
642 
643 
644 /* get a rip socket
645  */
646 static int				/* <0 or file descriptor */
647 get_rip_sock(naddr addr,
648 	     int serious)		/* 1=failure to bind is serious */
649 {
650 	struct sockaddr_in rsin;
651 	unsigned char ttl;
652 	int s;
653 
654 
655 	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
656 		BADERR(1,"rip_sock = socket()");
657 
658 	memset(&rsin, 0, sizeof(rsin));
659 #ifdef _HAVE_SIN_LEN
660 	rsin.sin_len = sizeof(rsin);
661 #endif
662 	rsin.sin_family = AF_INET;
663 	rsin.sin_port = htons(RIP_PORT);
664 	rsin.sin_addr.s_addr = addr;
665 	if (bind(s, (struct sockaddr *)&rsin, sizeof(rsin)) < 0) {
666 		if (serious)
667 			BADERR(errno != EADDRINUSE, "bind(rip_sock)");
668 		return -1;
669 	}
670 	fix_sock(s,"rip_sock");
671 
672 	ttl = 1;
673 	if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL,
674 		       &ttl, sizeof(ttl)) < 0)
675 		DBGERR(1,"rip_sock setsockopt(IP_MULTICAST_TTL)");
676 
677 	return s;
678 }
679 
680 
681 /* turn off main RIP socket */
682 void
683 rip_off(void)
684 {
685 	struct interface *ifp;
686 	naddr addr;
687 
688 
689 	if (rip_sock >= 0 && !mhome) {
690 		trace_act("turn off RIP");
691 
692 		(void)close(rip_sock);
693 		rip_sock = -1;
694 
695 		/* get non-broadcast sockets to listen to queries.
696 		 */
697 		LIST_FOREACH(ifp, &ifnet, int_list) {
698 			if (ifp->int_state & IS_REMOTE)
699 				continue;
700 			if (ifp->int_rip_sock < 0) {
701 				addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
702 					? ifp->int_dstaddr
703 					: ifp->int_addr);
704 				ifp->int_rip_sock = get_rip_sock(addr, 0);
705 			}
706 		}
707 
708 		fix_select();
709 
710 		age(0);
711 	}
712 }
713 
714 
715 /* turn on RIP multicast input via an interface
716  */
717 static void
718 rip_mcast_on(struct interface *ifp)
719 {
720 	struct group_req gr;
721 	struct sockaddr_in *sin;
722 
723 	if (!IS_RIP_IN_OFF(ifp->int_state)
724 	    && (ifp->int_if_flags & IFF_MULTICAST)
725 	    && !(ifp->int_state & IS_ALIAS)) {
726 		memset(&gr, 0, sizeof(gr));
727 		gr.gr_interface = ifp->int_index;
728 		sin = (struct sockaddr_in *)&gr.gr_group;
729 		sin->sin_family = AF_INET;
730 #ifdef _HAVE_SIN_LEN
731 		sin->sin_len = sizeof(struct sockaddr_in);
732 #endif
733 		sin->sin_addr.s_addr = htonl(INADDR_RIP_GROUP);
734 		if (setsockopt(rip_sock, IPPROTO_IP, MCAST_JOIN_GROUP,
735 			       &gr, sizeof(gr)) < 0)
736 			LOGERR("setsockopt(MCAST_JOIN_GROUP RIP)");
737 	}
738 }
739 
740 
741 /* Prepare socket used for RIP.
742  */
743 void
744 rip_on(struct interface *ifp)
745 {
746 	/* If the main RIP socket is already alive, only start receiving
747 	 * multicasts for this interface.
748 	 */
749 	if (rip_sock >= 0) {
750 		if (ifp != NULL)
751 			rip_mcast_on(ifp);
752 		return;
753 	}
754 
755 	/* If the main RIP socket is off and it makes sense to turn it on,
756 	 * then turn it on for all of the interfaces.
757 	 * It makes sense if either router discovery is off, or if
758 	 * router discover is on and at most one interface is doing RIP.
759 	 */
760 	if (rip_interfaces > 0 && (!rdisc_ok || rip_interfaces > 1)) {
761 		trace_act("turn on RIP");
762 
763 		/* Close all of the query sockets so that we can open
764 		 * the main socket.  SO_REUSEPORT is not a solution,
765 		 * since that would let two daemons bind to the broadcast
766 		 * socket.
767 		 */
768 		LIST_FOREACH(ifp, &ifnet, int_list) {
769 			if (ifp->int_rip_sock >= 0) {
770 				(void)close(ifp->int_rip_sock);
771 				ifp->int_rip_sock = -1;
772 			}
773 		}
774 
775 		rip_sock = get_rip_sock(INADDR_ANY, 1);
776 		rip_sock_mcast = NULL;
777 
778 		/* Do not advertise anything until we have heard something
779 		 */
780 		if (next_bcast.tv_sec < now.tv_sec+MIN_WAITTIME)
781 			next_bcast.tv_sec = now.tv_sec+MIN_WAITTIME;
782 
783 		LIST_FOREACH(ifp, &ifnet, int_list) {
784 			ifp->int_query_time = NEVER;
785 			rip_mcast_on(ifp);
786 		}
787 		ifinit_timer.tv_sec = now.tv_sec;
788 
789 	} else if (ifp != NULL
790 		   && !(ifp->int_state & IS_REMOTE)
791 		   && ifp->int_rip_sock < 0) {
792 		/* RIP is off, so ensure there are sockets on which
793 		 * to listen for queries.
794 		 */
795 		ifp->int_rip_sock = get_rip_sock(ifp->int_addr, 0);
796 	}
797 
798 	fix_select();
799 }
800 
801 
802 /* die if malloc(3) fails
803  */
804 void *
805 rtmalloc(size_t size,
806 	 const char *msg)
807 {
808 	void *p = malloc(size);
809 	if (p == NULL)
810 		logbad(1,"malloc(%lu) failed in %s", (u_long)size, msg);
811 	return p;
812 }
813 
814 
815 /* get a random instant in an interval
816  */
817 void
818 intvl_random(struct timeval *tp,	/* put value here */
819 	     u_long lo,			/* value is after this second */
820 	     u_long hi)			/* and before this */
821 {
822 	tp->tv_sec = (time_t)(hi == lo
823 			      ? lo
824 			      : (lo + arc4random_uniform(1 + hi - lo)));
825 	tp->tv_usec = arc4random_uniform(1000000);
826 }
827 
828 
829 void
830 timevaladd(struct timeval *t1,
831 	   struct timeval *t2)
832 {
833 
834 	t1->tv_sec += t2->tv_sec;
835 	if ((t1->tv_usec += t2->tv_usec) >= 1000000) {
836 		t1->tv_sec++;
837 		t1->tv_usec -= 1000000;
838 	}
839 }
840 
841 
842 /* t1 = t2 - t3
843  */
844 static void
845 timevalsub(struct timeval *t1,
846 	   struct timeval *t2,
847 	   struct timeval *t3)
848 {
849 	t1->tv_sec = t2->tv_sec - t3->tv_sec;
850 	if ((t1->tv_usec = t2->tv_usec - t3->tv_usec) < 0) {
851 		t1->tv_sec--;
852 		t1->tv_usec += 1000000;
853 	}
854 }
855 
856 
857 /* put a message into the system log
858  */
859 void
860 msglog(const char *p, ...)
861 {
862 	va_list args;
863 
864 	trace_flush();
865 
866 	va_start(args, p);
867 	vsyslog(LOG_ERR, p, args);
868 	va_end(args);
869 	if (ftrace != NULL) {
870 		if (ftrace == stdout)
871 			(void)fputs("routed: ", ftrace);
872 		va_start(args, p);
873 		(void)vfprintf(ftrace, p, args);
874 		va_end(args);
875 		(void)fputc('\n', ftrace);
876 	}
877 }
878 
879 
880 /* Put a message about a bad system into the system log if
881  * we have not complained about it recently.
882  *
883  * It is desirable to complain about all bad systems, but not too often.
884  * In the worst case, it is not practical to keep track of all bad systems.
885  * For example, there can be many systems with the wrong password.
886  */
887 void
888 msglim(struct msg_limit *lim, naddr addr, const char *p, ...)
889 {
890 	va_list args;
891 	int i;
892 	struct msg_sub *ms1, *ms;
893 	const char *p1;
894 
895 	/* look for the oldest slot in the table
896 	 * or the slot for the bad router.
897 	 */
898 	ms = ms1 = lim->subs;
899 	for (i = MSG_SUBJECT_N; ; i--, ms1++) {
900 		if (i == 0) {
901 			/* Reuse a slot at most once every 10 minutes.
902 			 */
903 			if (lim->reuse > now.tv_sec) {
904 				ms = NULL;
905 			} else {
906 				ms = ms1;
907 				lim->reuse = now.tv_sec + 10*60;
908 			}
909 			break;
910 		}
911 		if (ms->addr == addr) {
912 			/* Repeat a complaint about a given system at
913 			 * most once an hour.
914 			 */
915 			if (ms->until > now.tv_sec)
916 				ms = NULL;
917 			break;
918 		}
919 		if (ms->until < ms1->until)
920 			ms = ms1;
921 	}
922 	if (ms != NULL) {
923 		ms->addr = addr;
924 		ms->until = now.tv_sec + 60*60;	/* 60 minutes */
925 
926 		trace_flush();
927 		for (p1 = p; *p1 == ' '; p1++)
928 			continue;
929 		va_start(args, p);
930 		vsyslog(LOG_ERR, p1, args);
931 		va_end(args);
932 	}
933 
934 	/* always display the message if tracing */
935 	if (ftrace != NULL) {
936 		va_start(args, p);
937 		(void)vfprintf(ftrace, p, args);
938 		va_end(args);
939 		(void)fputc('\n', ftrace);
940 	}
941 }
942 
943 
944 void
945 logbad(int dump, const char *p, ...)
946 {
947 	va_list args;
948 
949 	trace_flush();
950 
951 	va_start(args, p);
952 	vsyslog(LOG_ERR, p, args);
953 	va_end(args);
954 	(void)fputs("routed: ", stderr);
955 	va_start(args, p);
956 	(void)vfprintf(stderr, p, args);
957 	va_end(args);
958 	(void)fputs("; giving up\n",stderr);
959 	(void)fflush(stderr);
960 
961 	if (dump)
962 		abort();
963 	exit(1);
964 }
965