xref: /netbsd-src/sbin/routed/main.c (revision 404fbe5fb94ca1e054339640cabb2801ce52dd30)
1 /*	$NetBSD: main.c,v 1.40 2008/07/20 01:20:23 lukem Exp $	*/
2 
3 /*
4  * Copyright (c) 1983, 1988, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgment:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include "defs.h"
37 #include "pathnames.h"
38 #ifdef sgi
39 #include "math.h"
40 #endif
41 #include <signal.h>
42 #include <fcntl.h>
43 #include <sys/file.h>
44 
45 __COPYRIGHT("@(#) Copyright (c) 1983, 1988, 1993\
46  The Regents of the University of California.  All rights reserved.");
47 #ifdef __NetBSD__
48 __RCSID("$NetBSD: main.c,v 1.40 2008/07/20 01:20:23 lukem Exp $");
49 #elif defined(__FreeBSD__)
50 __RCSID("$FreeBSD$");
51 #else
52 __RCSID("Revision: 2.27 ");
53 #ident "Revision: 2.27 "
54 #endif
55 
56 #if defined(__NetBSD__)
57 #include <util.h>
58 #endif
59 
60 pid_t	mypid;
61 
62 naddr	myaddr;				/* system address */
63 char	myname[MAXHOSTNAMELEN+1];
64 
65 int	verbose;
66 
67 int	supplier;			/* supply or broadcast updates */
68 int	supplier_set;
69 int	ipforwarding = 1;		/* kernel forwarding on */
70 
71 int	default_gateway;		/* 1=advertise default */
72 int	background = 1;
73 int	ridhosts;			/* 1=reduce host routes */
74 int	mhome;				/* 1=want multi-homed host route */
75 int	advertise_mhome;		/* 1=must continue advertising it */
76 int	auth_ok = 1;			/* 1=ignore auth if we do not care */
77 
78 struct timeval epoch;			/* when started */
79 struct timeval clk, prev_clk;
80 static int usec_fudge;
81 struct timeval now;			/* current idea of time */
82 time_t	now_stale;
83 time_t	now_expire;
84 time_t	now_garbage;
85 
86 struct timeval next_bcast;		/* next general broadcast */
87 struct timeval no_flash = {		/* inhibit flash update */
88 	EPOCH+SUPPLY_INTERVAL, 0
89 };
90 
91 struct timeval flush_kern_timer;
92 
93 fd_set	*fdbitsp;
94 int	sock_max;
95 int	rip_sock = -1;			/* RIP socket */
96 struct interface *rip_sock_mcast;	/* current multicast interface */
97 int	rt_sock;			/* routing socket */
98 int	rt_sock_seqno;
99 
100 
101 static  int get_rip_sock(naddr, int);
102 static void timevalsub(struct timeval *, struct timeval *, struct timeval *);
103 
104 int
105 main(int argc,
106      char *argv[])
107 {
108 	int n, mib[4], off;
109 	size_t len;
110 	char *p, *q;
111 	const char *cp;
112 	struct timeval wtime, t2;
113 	time_t dt;
114 	fd_set *ibitsp = NULL;
115 	naddr p_net, p_mask;
116 	struct interface *ifp;
117 	struct parm parm;
118 	char *tracename = 0;
119 
120 
121 	/* Some shells are badly broken and send SIGHUP to backgrounded
122 	 * processes.
123 	 */
124 	signal(SIGHUP, SIG_IGN);
125 
126 	openlog("routed", LOG_PID, LOG_DAEMON);
127 	ftrace = stdout;
128 
129 	gettimeofday(&clk, 0);
130 	prev_clk = clk;
131 	epoch = clk;
132 	epoch.tv_sec -= EPOCH;
133 	now.tv_sec = EPOCH;
134 	now_stale = EPOCH - STALE_TIME;
135 	now_expire = EPOCH - EXPIRE_TIME;
136 	now_garbage = EPOCH - GARBAGE_TIME;
137 	wtime.tv_sec = 0;
138 
139 	(void)gethostname(myname, sizeof(myname) - 1);
140 	(void)gethost(myname, &myaddr);
141 
142 	while ((n = getopt(argc, argv, "sqdghmAtvT:F:P:")) != -1) {
143 		switch (n) {
144 		case 's':
145 			supplier = 1;
146 			supplier_set = 1;
147 			break;
148 
149 		case 'q':
150 			supplier = 0;
151 			supplier_set = 1;
152 			break;
153 
154 		case 'd':
155 			background = 0;
156 			break;
157 
158 		case 'g':
159 			memset(&parm, 0, sizeof(parm));
160 			parm.parm_d_metric = 1;
161 			cp = check_parms(&parm);
162 			if (cp != 0)
163 				msglog("bad -g: %s", cp);
164 			else
165 				default_gateway = 1;
166 			break;
167 
168 		case 'h':		/* suppress extra host routes */
169 			ridhosts = 1;
170 			break;
171 
172 		case 'm':		/* advertise host route */
173 			mhome = 1;	/* on multi-homed hosts */
174 			break;
175 
176 		case 'A':
177 			/* Ignore authentication if we do not care.
178 			 * Crazy as it is, that is what RFC 1723 requires.
179 			 */
180 			auth_ok = 0;
181 			break;
182 
183 		case 't':
184 			new_tracelevel++;
185 			break;
186 
187 		case 'T':
188 			tracename = optarg;
189 			break;
190 
191 		case 'F':		/* minimal routes for SLIP */
192 			n = FAKE_METRIC;
193 			p = strchr(optarg,',');
194 			if (p && *p != '\0') {
195 				n = (int)strtoul(p+1, &q, 0);
196 				if (*q == '\0'
197 				    && n <= HOPCNT_INFINITY-1
198 				    && n >= 1)
199 					*p = '\0';
200 			}
201 			if (!getnet(optarg, &p_net, &p_mask)) {
202 				msglog("bad network; \"-F %s\"",
203 				       optarg);
204 				break;
205 			}
206 			memset(&parm, 0, sizeof(parm));
207 			parm.parm_net = p_net;
208 			parm.parm_mask = p_mask;
209 			parm.parm_d_metric = n;
210 			cp = check_parms(&parm);
211 			if (cp != 0)
212 				msglog("bad -F: %s", cp);
213 			break;
214 
215 		case 'P':
216 			/* handle arbitrary parameters.
217 			 */
218 			q = strdup(optarg);
219 			cp = parse_parms(q, 0);
220 			if (cp != 0)
221 				msglog("%s in \"-P %s\"", cp, optarg);
222 			free(q);
223 			break;
224 
225 		case 'v':
226 			/* display version */
227 			verbose++;
228 			msglog("version 2.28");
229 			break;
230 
231 		default:
232 			goto usage;
233 		}
234 	}
235 	argc -= optind;
236 	argv += optind;
237 
238 	if (tracename == 0 && argc >= 1) {
239 		tracename = *argv++;
240 		argc--;
241 	}
242 	if (tracename != 0 && tracename[0] == '\0')
243 		goto usage;
244 	if (argc != 0) {
245 usage:
246 		logbad(0, "usage: routed [-sqdghmAtv] [-T tracefile]"
247 		       " [-F net[/mask[,metric]]] [-P parms]");
248 	}
249 	if (geteuid() != 0) {
250 		if (verbose)
251 			exit(0);
252 		logbad(0, "requires UID 0");
253 	}
254 
255 	mib[0] = CTL_NET;
256 	mib[1] = PF_INET;
257 	mib[2] = IPPROTO_IP;
258 	mib[3] = IPCTL_FORWARDING;
259 	len = sizeof(ipforwarding);
260 	if (sysctl(mib, 4, &ipforwarding, &len, 0, 0) < 0)
261 		LOGERR("sysctl(IPCTL_FORWARDING)");
262 
263 	if (!ipforwarding) {
264 		if (supplier)
265 			msglog("-s incompatible with ipforwarding=0");
266 		if (default_gateway) {
267 			msglog("-g incompatible with ipforwarding=0");
268 			default_gateway = 0;
269 		}
270 		supplier = 0;
271 		supplier_set = 1;
272 	}
273 	if (default_gateway) {
274 		if (supplier_set && !supplier) {
275 			msglog("-g and -q incompatible");
276 		} else {
277 			supplier = 1;
278 			supplier_set = 1;
279 		}
280 	}
281 
282 
283 	signal(SIGALRM, sigalrm);
284 	if (!background)
285 		signal(SIGHUP, sigterm);    /* SIGHUP fatal during debugging */
286 	signal(SIGTERM, sigterm);
287 	signal(SIGINT, sigterm);
288 	signal(SIGUSR1, sigtrace_on);
289 	signal(SIGUSR2, sigtrace_off);
290 
291 	/* get into the background */
292 #ifdef sgi
293 	if (0 > _daemonize(background ? 0 : (_DF_NOCHDIR|_DF_NOFORK),
294 			   STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO))
295 		BADERR(0, "_daemonize()");
296 #else
297 	if (background && daemon(0, 1) < 0)
298 		BADERR(0,"daemon()");
299 #endif
300 
301 #if defined(__NetBSD__)
302 	pidfile(NULL);
303 #endif
304 	mypid = getpid();
305 
306 	/* prepare socket connected to the kernel.
307 	 */
308 	rt_sock = socket(AF_ROUTE, SOCK_RAW, 0);
309 	if (rt_sock < 0)
310 		BADERR(1,"rt_sock = socket()");
311 	if (fcntl(rt_sock, F_SETFL, O_NONBLOCK) == -1)
312 		logbad(1, "fcntl(rt_sock) O_NONBLOCK: %s", strerror(errno));
313 	off = 0;
314 	if (setsockopt(rt_sock, SOL_SOCKET,SO_USELOOPBACK,
315 		       &off,sizeof(off)) < 0)
316 		LOGERR("setsockopt(SO_USELOOPBACK,0)");
317 
318 	fix_select();
319 
320 
321 	if (tracename != 0) {
322 		strlcpy(inittracename, tracename, sizeof(inittracename));
323 		set_tracefile(inittracename, "%s", -1);
324 	} else {
325 		tracelevel_msg("%s", -1);   /* turn on tracing to stdio */
326 	}
327 
328 	bufinit();
329 
330 	/* initialize radix tree */
331 	rtinit();
332 
333 	/* Pick a random part of the second for our output to minimize
334 	 * collisions.
335 	 *
336 	 * Start broadcasting after hearing from other routers, and
337 	 * at a random time so a bunch of systems do not get synchronized
338 	 * after a power failure.
339 	 */
340 	intvl_random(&next_bcast, EPOCH+MIN_WAITTIME, EPOCH+SUPPLY_INTERVAL);
341 	age_timer.tv_usec = next_bcast.tv_usec;
342 	age_timer.tv_sec = EPOCH+MIN_WAITTIME;
343 	rdisc_timer = next_bcast;
344 	ifinit_timer.tv_usec = next_bcast.tv_usec;
345 
346 	/* Collect an initial view of the world by checking the interface
347 	 * configuration and the kludge file.
348 	 */
349 	gwkludge();
350 	ifinit();
351 
352 	/* Ask for routes */
353 	rip_query();
354 	rdisc_sol();
355 
356 	/* Now turn off stdio if not tracing */
357 	if (new_tracelevel == 0)
358 		trace_close(background);
359 
360 	/* Loop forever, listening and broadcasting.
361 	 */
362 	for (;;) {
363 		prev_clk = clk;
364 		gettimeofday(&clk, 0);
365 		if (prev_clk.tv_sec == clk.tv_sec
366 		    && prev_clk.tv_usec == clk.tv_usec+usec_fudge) {
367 			/* Much of `routed` depends on time always advancing.
368 			 * On systems that do not guarantee that gettimeofday()
369 			 * produces unique timestamps even if called within
370 			 * a single tick, use trickery like that in classic
371 			 * BSD kernels.
372 			 */
373 			clk.tv_usec += ++usec_fudge;
374 
375 		} else {
376 			usec_fudge = 0;
377 
378 			timevalsub(&t2, &clk, &prev_clk);
379 			if (t2.tv_sec < 0
380 			    || t2.tv_sec > wtime.tv_sec + 5) {
381 				/* Deal with time changes before other
382 				 * housekeeping to keep everything straight.
383 				 */
384 				dt = t2.tv_sec;
385 				if (dt > 0)
386 					dt -= wtime.tv_sec;
387 				trace_act("time changed by %d sec", (int)dt);
388 				epoch.tv_sec += dt;
389 			}
390 		}
391 		timevalsub(&now, &clk, &epoch);
392 		now_stale = now.tv_sec - STALE_TIME;
393 		now_expire = now.tv_sec - EXPIRE_TIME;
394 		now_garbage = now.tv_sec - GARBAGE_TIME;
395 
396 		/* deal with signals that should affect tracing */
397 		set_tracelevel();
398 
399 		if (stopint != 0) {
400 			rip_bcast(0);
401 			rdisc_adv();
402 			trace_off("exiting with signal %d", stopint);
403 			exit(stopint | 128);
404 		}
405 
406 		/* look for new or dead interfaces */
407 		timevalsub(&wtime, &ifinit_timer, &now);
408 		if (wtime.tv_sec <= 0) {
409 			wtime.tv_sec = 0;
410 			ifinit();
411 			rip_query();
412 			continue;
413 		}
414 
415 		/* Check the kernel table occassionally for mysteriously
416 		 * evaporated routes
417 		 */
418 		timevalsub(&t2, &flush_kern_timer, &now);
419 		if (t2.tv_sec <= 0) {
420 			flush_kern();
421 			flush_kern_timer.tv_sec = (now.tv_sec
422 						   + CHECK_QUIET_INTERVAL);
423 			continue;
424 		}
425 		if (timercmp(&t2, &wtime, <))
426 			wtime = t2;
427 
428 		/* If it is time, then broadcast our routes.
429 		 */
430 		if (supplier || advertise_mhome) {
431 			timevalsub(&t2, &next_bcast, &now);
432 			if (t2.tv_sec <= 0) {
433 				/* Synchronize the aging and broadcast
434 				 * timers to minimize awakenings
435 				 */
436 				age(0);
437 
438 				rip_bcast(0);
439 
440 				/* It is desirable to send routing updates
441 				 * regularly.  So schedule the next update
442 				 * 30 seconds after the previous one was
443 				 * scheduled, instead of 30 seconds after
444 				 * the previous update was finished.
445 				 * Even if we just started after discovering
446 				 * a 2nd interface or were otherwise delayed,
447 				 * pick a 30-second aniversary of the
448 				 * original broadcast time.
449 				 */
450 				n = 1 + (0-t2.tv_sec)/SUPPLY_INTERVAL;
451 				next_bcast.tv_sec += n*SUPPLY_INTERVAL;
452 
453 				continue;
454 			}
455 
456 			if (timercmp(&t2, &wtime, <))
457 				wtime = t2;
458 		}
459 
460 		/* If we need a flash update, either do it now or
461 		 * set the delay to end when it is time.
462 		 *
463 		 * If we are within MIN_WAITTIME seconds of a full update,
464 		 * do not bother.
465 		 */
466 		if (need_flash
467 		    && supplier
468 		    && no_flash.tv_sec+MIN_WAITTIME < next_bcast.tv_sec) {
469 			/* accurate to the millisecond */
470 			if (!timercmp(&no_flash, &now, >))
471 				rip_bcast(1);
472 			timevalsub(&t2, &no_flash, &now);
473 			if (timercmp(&t2, &wtime, <))
474 				wtime = t2;
475 		}
476 
477 		/* trigger the main aging timer.
478 		 */
479 		timevalsub(&t2, &age_timer, &now);
480 		if (t2.tv_sec <= 0) {
481 			age(0);
482 			continue;
483 		}
484 		if (timercmp(&t2, &wtime, <))
485 			wtime = t2;
486 
487 		/* update the kernel routing table
488 		 */
489 		timevalsub(&t2, &need_kern, &now);
490 		if (t2.tv_sec <= 0) {
491 			age(0);
492 			continue;
493 		}
494 		if (timercmp(&t2, &wtime, <))
495 			wtime = t2;
496 
497 		/* take care of router discovery,
498 		 * but do it in the correct the millisecond
499 		 */
500 		if (!timercmp(&rdisc_timer, &now, >)) {
501 			rdisc_age(0);
502 			continue;
503 		}
504 		timevalsub(&t2, &rdisc_timer, &now);
505 		if (timercmp(&t2, &wtime, <))
506 			wtime = t2;
507 
508 
509 		/* wait for input or a timer to expire.
510 		 */
511 		trace_flush();
512 		if (ibitsp)
513 			free(ibitsp);
514 		ibitsp = (fd_set *)calloc(howmany(sock_max, NFDBITS),
515 		    sizeof(fd_mask));
516 		if (ibitsp == NULL)
517 			BADERR(1, "calloc");
518 		memcpy(ibitsp, fdbitsp, howmany(sock_max, NFDBITS) *
519 		    sizeof(fd_mask));
520 		n = select(sock_max, ibitsp, 0, 0, &wtime);
521 		if (n <= 0) {
522 			if (n < 0 && errno != EINTR && errno != EAGAIN)
523 				BADERR(1,"select");
524 			continue;
525 		}
526 
527 		if (FD_ISSET(rt_sock, ibitsp)) {
528 			read_rt();
529 			n--;
530 		}
531 		if (rdisc_sock >= 0 && FD_ISSET(rdisc_sock, ibitsp)) {
532 			read_d();
533 			n--;
534 		}
535 		if (rip_sock >= 0 && FD_ISSET(rip_sock, ibitsp)) {
536 			read_rip(rip_sock, 0);
537 			n--;
538 		}
539 
540 		for (ifp = ifnet; n > 0 && 0 != ifp; ifp = ifp->int_next) {
541 			if (ifp->int_rip_sock >= 0
542 			    && FD_ISSET(ifp->int_rip_sock, ibitsp)) {
543 				read_rip(ifp->int_rip_sock, ifp);
544 				n--;
545 			}
546 		}
547 	}
548 }
549 
550 
551 /* ARGSUSED */
552 void
553 sigalrm(int s UNUSED)
554 {
555 	/* Historically, SIGALRM would cause the daemon to check for
556 	 * new and broken interfaces.
557 	 */
558 	ifinit_timer.tv_sec = now.tv_sec;
559 	trace_act("SIGALRM");
560 }
561 
562 
563 /* watch for fatal signals */
564 void
565 sigterm(int sig)
566 {
567 	stopint = sig;
568 	(void)signal(sig, SIG_DFL);	/* catch it only once */
569 }
570 
571 
572 void
573 fix_select(void)
574 {
575 	struct interface *ifp;
576 
577 	sock_max = 0;
578 
579 	if (sock_max <= rt_sock)
580 		sock_max = rt_sock + 1;
581 	if (rip_sock >= 0)
582 		if (sock_max <= rip_sock)
583 			sock_max = rip_sock + 1;
584 	for (ifp = ifnet; 0 != ifp; ifp = ifp->int_next) {
585 		if (ifp->int_rip_sock >= 0)
586 			if (sock_max <= ifp->int_rip_sock)
587 				sock_max = ifp->int_rip_sock + 1;
588 	}
589 	if (rdisc_sock >= 0)
590 		if (sock_max <= rdisc_sock)
591 			sock_max = rdisc_sock + 1;
592 
593 	if (fdbitsp)
594 		free(fdbitsp);
595 	fdbitsp = (fd_set *)calloc(howmany(sock_max, NFDBITS),
596 	    sizeof(fd_mask));
597 	if (fdbitsp == NULL)
598 		BADERR(1, "calloc");
599 
600 	FD_SET(rt_sock, fdbitsp);
601 	if (rip_sock >= 0)
602 		FD_SET(rip_sock, fdbitsp);
603 	for (ifp = ifnet; 0 != ifp; ifp = ifp->int_next) {
604 		if (ifp->int_rip_sock >= 0)
605 			FD_SET(ifp->int_rip_sock, fdbitsp);
606 	}
607 	if (rdisc_sock >= 0)
608 		FD_SET(rdisc_sock, fdbitsp);
609 }
610 
611 
612 void
613 fix_sock(int sock,
614 	 const char *name)
615 {
616 	int on;
617 #define MIN_SOCKBUF (4*1024)
618 	static int rbuf;
619 
620 	if (fcntl(sock, F_SETFL, O_NONBLOCK) == -1)
621 		logbad(1, "fcntl(%s) O_NONBLOCK: %s",
622 		       name, strerror(errno));
623 	on = 1;
624 	if (setsockopt(sock, SOL_SOCKET,SO_BROADCAST, &on,sizeof(on)) < 0)
625 		msglog("setsockopt(%s,SO_BROADCAST): %s",
626 		       name, strerror(errno));
627 #ifdef USE_PASSIFNAME
628 	on = 1;
629 	if (setsockopt(sock, SOL_SOCKET, SO_PASSIFNAME, &on,sizeof(on)) < 0)
630 		msglog("setsockopt(%s,SO_PASSIFNAME): %s",
631 		       name, strerror(errno));
632 #endif
633 
634 	if (rbuf >= MIN_SOCKBUF) {
635 		if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
636 			       &rbuf, sizeof(rbuf)) < 0)
637 			msglog("setsockopt(%s,SO_RCVBUF=%d): %s",
638 			       name, rbuf, strerror(errno));
639 	} else {
640 		for (rbuf = 60*1024; ; rbuf -= 4096) {
641 			if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
642 				       &rbuf, sizeof(rbuf)) == 0) {
643 				trace_act("RCVBUF=%d", rbuf);
644 				break;
645 			}
646 			if (rbuf < MIN_SOCKBUF) {
647 				msglog("setsockopt(%s,SO_RCVBUF = %d): %s",
648 				       name, rbuf, strerror(errno));
649 				break;
650 			}
651 		}
652 	}
653 }
654 
655 
656 /* get a rip socket
657  */
658 static int				/* <0 or file descriptor */
659 get_rip_sock(naddr addr,
660 	     int serious)		/* 1=failure to bind is serious */
661 {
662 	struct sockaddr_in rsin;
663 	unsigned char ttl;
664 	int s;
665 
666 
667 	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
668 		BADERR(1,"rip_sock = socket()");
669 
670 	memset(&rsin, 0, sizeof(rsin));
671 #ifdef _HAVE_SIN_LEN
672 	rsin.sin_len = sizeof(rsin);
673 #endif
674 	rsin.sin_family = AF_INET;
675 	rsin.sin_port = htons(RIP_PORT);
676 	rsin.sin_addr.s_addr = addr;
677 	if (bind(s, (struct sockaddr *)&rsin, sizeof(rsin)) < 0) {
678 		if (serious)
679 			BADERR(errno != EADDRINUSE, "bind(rip_sock)");
680 		return -1;
681 	}
682 	fix_sock(s,"rip_sock");
683 
684 	ttl = 1;
685 	if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL,
686 		       &ttl, sizeof(ttl)) < 0)
687 		DBGERR(1,"rip_sock setsockopt(IP_MULTICAST_TTL)");
688 
689 	return s;
690 }
691 
692 
693 /* turn off main RIP socket */
694 void
695 rip_off(void)
696 {
697 	struct interface *ifp;
698 	naddr addr;
699 
700 
701 	if (rip_sock >= 0 && !mhome) {
702 		trace_act("turn off RIP");
703 
704 		(void)close(rip_sock);
705 		rip_sock = -1;
706 
707 		/* get non-broadcast sockets to listen to queries.
708 		 */
709 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
710 			if (ifp->int_state & IS_REMOTE)
711 				continue;
712 			if (ifp->int_rip_sock < 0) {
713 				addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
714 					? ifp->int_dstaddr
715 					: ifp->int_addr);
716 				ifp->int_rip_sock = get_rip_sock(addr, 0);
717 			}
718 		}
719 
720 		fix_select();
721 
722 		age(0);
723 	}
724 }
725 
726 
727 /* turn on RIP multicast input via an interface
728  */
729 static void
730 rip_mcast_on(struct interface *ifp)
731 {
732 	struct ip_mreq m;
733 
734 	if (!IS_RIP_IN_OFF(ifp->int_state)
735 	    && (ifp->int_if_flags & IFF_MULTICAST)
736 #ifdef MCAST_PPP_BUG
737 	    && !(ifp->int_if_flags & IFF_POINTOPOINT)
738 #endif
739 	    && !(ifp->int_state & IS_ALIAS)) {
740 		m.imr_multiaddr.s_addr = htonl(INADDR_RIP_GROUP);
741 #ifdef MCAST_IFINDEX
742 		m.imr_interface.s_addr = htonl(ifp->int_index);
743 #else
744 		m.imr_interface.s_addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
745 					  ? ifp->int_dstaddr
746 					  : ifp->int_addr);
747 #endif
748 		if (setsockopt(rip_sock,IPPROTO_IP, IP_ADD_MEMBERSHIP,
749 			       &m, sizeof(m)) < 0)
750 			LOGERR("setsockopt(IP_ADD_MEMBERSHIP RIP)");
751 	}
752 }
753 
754 
755 /* Prepare socket used for RIP.
756  */
757 void
758 rip_on(struct interface *ifp)
759 {
760 	/* If the main RIP socket is already alive, only start receiving
761 	 * multicasts for this interface.
762 	 */
763 	if (rip_sock >= 0) {
764 		if (ifp != 0)
765 			rip_mcast_on(ifp);
766 		return;
767 	}
768 
769 	/* If the main RIP socket is off and it makes sense to turn it on,
770 	 * then turn it on for all of the interfaces.
771 	 * It makes sense if either router discovery is off, or if
772 	 * router discover is on and at most one interface is doing RIP.
773 	 */
774 	if (rip_interfaces > 0 && (!rdisc_ok || rip_interfaces > 1)) {
775 		trace_act("turn on RIP");
776 
777 		/* Close all of the query sockets so that we can open
778 		 * the main socket.  SO_REUSEPORT is not a solution,
779 		 * since that would let two daemons bind to the broadcast
780 		 * socket.
781 		 */
782 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
783 			if (ifp->int_rip_sock >= 0) {
784 				(void)close(ifp->int_rip_sock);
785 				ifp->int_rip_sock = -1;
786 			}
787 		}
788 
789 		rip_sock = get_rip_sock(INADDR_ANY, 1);
790 		rip_sock_mcast = 0;
791 
792 		/* Do not advertise anything until we have heard something
793 		 */
794 		if (next_bcast.tv_sec < now.tv_sec+MIN_WAITTIME)
795 			next_bcast.tv_sec = now.tv_sec+MIN_WAITTIME;
796 
797 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
798 			ifp->int_query_time = NEVER;
799 			rip_mcast_on(ifp);
800 		}
801 		ifinit_timer.tv_sec = now.tv_sec;
802 
803 	} else if (ifp != 0
804 		   && !(ifp->int_state & IS_REMOTE)
805 		   && ifp->int_rip_sock < 0) {
806 		/* RIP is off, so ensure there are sockets on which
807 		 * to listen for queries.
808 		 */
809 		ifp->int_rip_sock = get_rip_sock(ifp->int_addr, 0);
810 	}
811 
812 	fix_select();
813 }
814 
815 
816 /* die if malloc(3) fails
817  */
818 void *
819 rtmalloc(size_t size,
820 	 const char *msg)
821 {
822 	void *p = malloc(size);
823 	if (p == 0)
824 		logbad(1,"malloc(%lu) failed in %s", (u_long)size, msg);
825 	return p;
826 }
827 
828 
829 /* get a random instant in an interval
830  */
831 void
832 intvl_random(struct timeval *tp,	/* put value here */
833 	     u_long lo,			/* value is after this second */
834 	     u_long hi)			/* and before this */
835 {
836 	tp->tv_sec = (time_t)(hi == lo
837 			      ? lo
838 			      : (lo + arc4random() % ((hi - lo))));
839 	tp->tv_usec = arc4random() % 1000000;
840 }
841 
842 
843 void
844 timevaladd(struct timeval *t1,
845 	   struct timeval *t2)
846 {
847 
848 	t1->tv_sec += t2->tv_sec;
849 	if ((t1->tv_usec += t2->tv_usec) >= 1000000) {
850 		t1->tv_sec++;
851 		t1->tv_usec -= 1000000;
852 	}
853 }
854 
855 
856 /* t1 = t2 - t3
857  */
858 static void
859 timevalsub(struct timeval *t1,
860 	   struct timeval *t2,
861 	   struct timeval *t3)
862 {
863 	t1->tv_sec = t2->tv_sec - t3->tv_sec;
864 	if ((t1->tv_usec = t2->tv_usec - t3->tv_usec) < 0) {
865 		t1->tv_sec--;
866 		t1->tv_usec += 1000000;
867 	}
868 }
869 
870 
871 /* put a message into the system log
872  */
873 void
874 msglog(const char *p, ...)
875 {
876 	va_list args;
877 
878 	trace_flush();
879 
880 	va_start(args, p);
881 	vsyslog(LOG_ERR, p, args);
882 	va_end(args);
883 
884 	if (ftrace != 0) {
885 		if (ftrace == stdout)
886 			(void)fputs("routed: ", ftrace);
887 		va_start(args, p);
888 		(void)vfprintf(ftrace, p, args);
889 		va_end(args);
890 		(void)fputc('\n', ftrace);
891 	}
892 }
893 
894 
895 /* Put a message about a bad system into the system log if
896  * we have not complained about it recently.
897  *
898  * It is desirable to complain about all bad systems, but not too often.
899  * In the worst case, it is not practical to keep track of all bad systems.
900  * For example, there can be many systems with the wrong password.
901  */
902 void
903 msglim(struct msg_limit *lim, naddr addr, const char *p, ...)
904 {
905 	va_list args;
906 	int i;
907 	struct msg_sub *ms1, *ms;
908 	const char *p1;
909 
910 	/* look for the oldest slot in the table
911 	 * or the slot for the bad router.
912 	 */
913 	ms = ms1 = lim->subs;
914 	for (i = MSG_SUBJECT_N; ; i--, ms1++) {
915 		if (i == 0) {
916 			/* Reuse a slot at most once every 10 minutes.
917 			 */
918 			if (lim->reuse > now.tv_sec) {
919 				ms = 0;
920 			} else {
921 				ms = ms1;
922 				lim->reuse = now.tv_sec + 10*60;
923 			}
924 			break;
925 		}
926 		if (ms->addr == addr) {
927 			/* Repeat a complaint about a given system at
928 			 * most once an hour.
929 			 */
930 			if (ms->until > now.tv_sec)
931 				ms = 0;
932 			break;
933 		}
934 		if (ms->until < ms1->until)
935 			ms = ms1;
936 	}
937 	if (ms != 0) {
938 		ms->addr = addr;
939 		ms->until = now.tv_sec + 60*60;	/* 60 minutes */
940 
941 		trace_flush();
942 		for (p1 = p; *p1 == ' '; p1++)
943 			continue;
944 		va_start(args, p);
945 		vsyslog(LOG_ERR, p1, args);
946 		va_end(args);
947 	}
948 
949 	/* always display the message if tracing */
950 	if (ftrace != 0) {
951 		va_start(args, p);
952 		(void)vfprintf(ftrace, p, args);
953 		(void)fputc('\n', ftrace);
954 		va_end(args);
955 	}
956 }
957 
958 
959 void
960 logbad(int dump, const char *p, ...)
961 {
962 	va_list args;
963 
964 	trace_flush();
965 
966 	va_start(args, p);
967 	vsyslog(LOG_ERR, p, args);
968 	va_end(args);
969 
970 	(void)fputs("routed: ", stderr);
971 	va_start(args, p);
972 	(void)vfprintf(stderr, p, args);
973 	va_end(args);
974 	(void)fputs("; giving up\n",stderr);
975 	(void)fflush(stderr);
976 
977 	if (dump)
978 		abort();
979 	exit(1);
980 }
981