xref: /freebsd/sbin/routed/main.c (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include "defs.h"
33 #include "pathnames.h"
34 #include <signal.h>
35 #include <fcntl.h>
36 #include <sys/file.h>
37 
38 pid_t	mypid;
39 
40 naddr	myaddr;				/* system address */
41 static char myname[MAXHOSTNAMELEN+1];
42 
43 static int verbose;
44 
45 int	supplier;			/* supply or broadcast updates */
46 int	supplier_set;
47 static int ipforwarding = 1;		/* kernel forwarding on */
48 
49 static int default_gateway;		/* 1=advertise default */
50 static int background = 1;
51 int	ridhosts;			/* 1=reduce host routes */
52 int	mhome;				/* 1=want multi-homed host route */
53 int	advertise_mhome;		/* 1=must continue advertising it */
54 int	auth_ok = 1;			/* 1=ignore auth if we do not care */
55 int	insecure;			/* Reply to special queries or not */
56 
57 struct timeval epoch;			/* when started */
58 struct timeval clk;
59 static struct timeval prev_clk;
60 static int usec_fudge;
61 struct timeval now;			/* current idea of time */
62 time_t	now_stale;
63 time_t	now_expire;
64 time_t	now_garbage;
65 
66 static struct timeval next_bcast;	/* next general broadcast */
67 struct timeval no_flash = {		/* inhibit flash update */
68 	EPOCH+SUPPLY_INTERVAL, 0
69 };
70 
71 static struct timeval flush_kern_timer;
72 
73 static fd_set fdbits;
74 static int sock_max;
75 int	rip_sock = -1;			/* RIP socket */
76 const struct interface *rip_sock_mcast;	/* current multicast interface */
77 int	rt_sock;			/* routing socket */
78 int	rt_sock_seqno;
79 
80 
81 static  int get_rip_sock(naddr, int);
82 static void timevalsub(struct timeval *, struct timeval *, struct timeval *);
83 static void sigalrm(int s UNUSED);
84 static void sigterm(int sig);
85 
86 int
87 main(int argc,
88      char *argv[])
89 {
90 	int n, mib[4], off;
91 	size_t len;
92 	char *p, *q;
93 	const char *cp;
94 	struct timeval wtime, t2;
95 	time_t dt;
96 	fd_set ibits;
97 	naddr p_net, p_mask;
98 	struct interface *ifp;
99 	struct parm parm;
100 	char *tracename = 0;
101 
102 
103 	/* Some shells are badly broken and send SIGHUP to backgrounded
104 	 * processes.
105 	 */
106 	signal(SIGHUP, SIG_IGN);
107 
108 	openlog("routed", LOG_PID, LOG_DAEMON);
109 	ftrace = stdout;
110 
111 	gettimeofday(&clk, 0);
112 	prev_clk = clk;
113 	epoch = clk;
114 	epoch.tv_sec -= EPOCH;
115 	now.tv_sec = EPOCH;
116 	now_stale = EPOCH - STALE_TIME;
117 	now_expire = EPOCH - EXPIRE_TIME;
118 	now_garbage = EPOCH - GARBAGE_TIME;
119 	wtime.tv_sec = 0;
120 
121 	(void)gethostname(myname, sizeof(myname)-1);
122 	(void)gethost(myname, &myaddr);
123 
124 	while ((n = getopt(argc, argv, "isqdghmAtvT:F:P:")) != -1) {
125 		switch (n) {
126 		case 'i':
127 			insecure++;
128 			break;
129 		case 's':
130 			supplier = 1;
131 			supplier_set = 1;
132 			break;
133 
134 		case 'q':
135 			supplier = 0;
136 			supplier_set = 1;
137 			break;
138 
139 		case 'd':
140 			background = 0;
141 			break;
142 
143 		case 'g':
144 			memset(&parm, 0, sizeof(parm));
145 			parm.parm_d_metric = 1;
146 			cp = check_parms(&parm);
147 			if (cp != 0)
148 				msglog("bad -g: %s", cp);
149 			else
150 				default_gateway = 1;
151 			break;
152 
153 		case 'h':		/* suppress extra host routes */
154 			ridhosts = 1;
155 			break;
156 
157 		case 'm':		/* advertise host route */
158 			mhome = 1;	/* on multi-homed hosts */
159 			break;
160 
161 		case 'A':
162 			/* Ignore authentication if we do not care.
163 			 * Crazy as it is, that is what RFC 1723 requires.
164 			 */
165 			auth_ok = 0;
166 			break;
167 
168 		case 't':
169 			new_tracelevel++;
170 			break;
171 
172 		case 'T':
173 			tracename = optarg;
174 			break;
175 
176 		case 'F':		/* minimal routes for SLIP */
177 			n = FAKE_METRIC;
178 			p = strchr(optarg,',');
179 			if (p && *p != '\0') {
180 				n = (int)strtoul(p+1, &q, 0);
181 				if (*q == '\0'
182 				    && n <= HOPCNT_INFINITY-1
183 				    && n >= 1)
184 					*p = '\0';
185 			}
186 			if (!getnet(optarg, &p_net, &p_mask)) {
187 				msglog("bad network; \"-F %s\"",
188 				       optarg);
189 				break;
190 			}
191 			memset(&parm, 0, sizeof(parm));
192 			parm.parm_net = p_net;
193 			parm.parm_mask = p_mask;
194 			parm.parm_d_metric = n;
195 			cp = check_parms(&parm);
196 			if (cp != 0)
197 				msglog("bad -F: %s", cp);
198 			break;
199 
200 		case 'P':
201 			/* handle arbitrary parameters.
202 			 */
203 			q = strdup(optarg);
204 			cp = parse_parms(q, 0);
205 			if (cp != 0)
206 				msglog("%s in \"-P %s\"", cp, optarg);
207 			free(q);
208 			break;
209 
210 		case 'v':
211 			/* display version */
212 			verbose++;
213 			msglog("version 2.31");
214 			break;
215 
216 		default:
217 			goto usage;
218 		}
219 	}
220 	argc -= optind;
221 	argv += optind;
222 
223 	if (tracename == 0 && argc >= 1) {
224 		tracename = *argv++;
225 		argc--;
226 	}
227 	if (tracename != 0 && tracename[0] == '\0')
228 		goto usage;
229 	if (argc != 0) {
230 usage:
231 		logbad(0, "usage: routed [-sqdghmAtv] [-T tracefile]"
232 		       " [-F net[,metric]] [-P parms]");
233 	}
234 	if (geteuid() != 0) {
235 		if (verbose)
236 			exit(0);
237 		logbad(0, "requires UID 0");
238 	}
239 
240 	mib[0] = CTL_NET;
241 	mib[1] = PF_INET;
242 	mib[2] = IPPROTO_IP;
243 	mib[3] = IPCTL_FORWARDING;
244 	len = sizeof(ipforwarding);
245 	if (sysctl(mib, 4, &ipforwarding, &len, 0, 0) < 0)
246 		LOGERR("sysctl(IPCTL_FORWARDING)");
247 
248 	if (!ipforwarding) {
249 		if (supplier)
250 			msglog("-s incompatible with ipforwarding=0");
251 		if (default_gateway) {
252 			msglog("-g incompatible with ipforwarding=0");
253 			default_gateway = 0;
254 		}
255 		supplier = 0;
256 		supplier_set = 1;
257 	}
258 	if (default_gateway) {
259 		if (supplier_set && !supplier) {
260 			msglog("-g and -q incompatible");
261 		} else {
262 			supplier = 1;
263 			supplier_set = 1;
264 		}
265 	}
266 
267 
268 	signal(SIGALRM, sigalrm);
269 	if (!background)
270 		signal(SIGHUP, sigterm);    /* SIGHUP fatal during debugging */
271 	signal(SIGTERM, sigterm);
272 	signal(SIGINT, sigterm);
273 	signal(SIGUSR1, sigtrace_on);
274 	signal(SIGUSR2, sigtrace_off);
275 
276 	/* get into the background */
277 	if (background && daemon(0, 1) < 0)
278 		BADERR(0,"daemon()");
279 
280 	mypid = getpid();
281 
282 	/* prepare socket connected to the kernel.
283 	 */
284 	rt_sock = socket(AF_ROUTE, SOCK_RAW, 0);
285 	if (rt_sock < 0)
286 		BADERR(1,"rt_sock = socket()");
287 	if (fcntl(rt_sock, F_SETFL, O_NONBLOCK) == -1)
288 		logbad(1, "fcntl(rt_sock) O_NONBLOCK: %s", strerror(errno));
289 	off = 0;
290 	if (setsockopt(rt_sock, SOL_SOCKET,SO_USELOOPBACK,
291 		       &off,sizeof(off)) < 0)
292 		LOGERR("setsockopt(SO_USELOOPBACK,0)");
293 
294 	fix_select();
295 
296 
297 	if (tracename != 0) {
298 		strncpy(inittracename, tracename, sizeof(inittracename)-1);
299 		set_tracefile(inittracename, "%s", -1);
300 	} else {
301 		tracelevel_msg("%s", -1);   /* turn on tracing to stdio */
302 	}
303 
304 	bufinit();
305 
306 	/* initialize radix tree */
307 	rtinit();
308 
309 	/* Pick a random part of the second for our output to minimize
310 	 * collisions.
311 	 *
312 	 * Start broadcasting after hearing from other routers, and
313 	 * at a random time so a bunch of systems do not get synchronized
314 	 * after a power failure.
315 	 */
316 	intvl_random(&next_bcast, EPOCH+MIN_WAITTIME, EPOCH+SUPPLY_INTERVAL);
317 	age_timer.tv_usec = next_bcast.tv_usec;
318 	age_timer.tv_sec = EPOCH+MIN_WAITTIME;
319 	rdisc_timer = next_bcast;
320 	ifinit_timer.tv_usec = next_bcast.tv_usec;
321 
322 	/* Collect an initial view of the world by checking the interface
323 	 * configuration and the kludge file.
324 	 */
325 	gwkludge();
326 	ifinit();
327 
328 	/* Ask for routes */
329 	rip_query();
330 	rdisc_sol();
331 
332 	/* Now turn off stdio if not tracing */
333 	if (new_tracelevel == 0)
334 		trace_close(background);
335 
336 	/* Loop forever, listening and broadcasting.
337 	 */
338 	for (;;) {
339 		prev_clk = clk;
340 		gettimeofday(&clk, 0);
341 		if (prev_clk.tv_sec == clk.tv_sec
342 		    && prev_clk.tv_usec == clk.tv_usec+usec_fudge) {
343 			/* Much of `routed` depends on time always advancing.
344 			 * On systems that do not guarantee that gettimeofday()
345 			 * produces unique timestamps even if called within
346 			 * a single tick, use trickery like that in classic
347 			 * BSD kernels.
348 			 */
349 			clk.tv_usec += ++usec_fudge;
350 
351 		} else {
352 			usec_fudge = 0;
353 
354 			timevalsub(&t2, &clk, &prev_clk);
355 			if (t2.tv_sec < 0
356 			    || t2.tv_sec > wtime.tv_sec + 5) {
357 				/* Deal with time changes before other
358 				 * housekeeping to keep everything straight.
359 				 */
360 				dt = t2.tv_sec;
361 				if (dt > 0)
362 					dt -= wtime.tv_sec;
363 				trace_act("time changed by %d sec", (int)dt);
364 				epoch.tv_sec += dt;
365 			}
366 		}
367 		timevalsub(&now, &clk, &epoch);
368 		now_stale = now.tv_sec - STALE_TIME;
369 		now_expire = now.tv_sec - EXPIRE_TIME;
370 		now_garbage = now.tv_sec - GARBAGE_TIME;
371 
372 		/* deal with signals that should affect tracing */
373 		set_tracelevel();
374 
375 		if (stopint != 0) {
376 			rip_bcast(0);
377 			rdisc_adv();
378 			trace_off("exiting with signal %d", stopint);
379 			exit(stopint | 128);
380 		}
381 
382 		/* look for new or dead interfaces */
383 		timevalsub(&wtime, &ifinit_timer, &now);
384 		if (wtime.tv_sec <= 0) {
385 			wtime.tv_sec = 0;
386 			ifinit();
387 			rip_query();
388 			continue;
389 		}
390 
391 		/* Check the kernel table occasionally for mysteriously
392 		 * evaporated routes
393 		 */
394 		timevalsub(&t2, &flush_kern_timer, &now);
395 		if (t2.tv_sec <= 0) {
396 			flush_kern();
397 			flush_kern_timer.tv_sec = (now.tv_sec
398 						   + CHECK_QUIET_INTERVAL);
399 			continue;
400 		}
401 		if (timercmp(&t2, &wtime, <))
402 			wtime = t2;
403 
404 		/* If it is time, then broadcast our routes.
405 		 */
406 		if (supplier || advertise_mhome) {
407 			timevalsub(&t2, &next_bcast, &now);
408 			if (t2.tv_sec <= 0) {
409 				/* Synchronize the aging and broadcast
410 				 * timers to minimize awakenings
411 				 */
412 				age(0);
413 
414 				rip_bcast(0);
415 
416 				/* It is desirable to send routing updates
417 				 * regularly.  So schedule the next update
418 				 * 30 seconds after the previous one was
419 				 * scheduled, instead of 30 seconds after
420 				 * the previous update was finished.
421 				 * Even if we just started after discovering
422 				 * a 2nd interface or were otherwise delayed,
423 				 * pick a 30-second anniversary of the
424 				 * original broadcast time.
425 				 */
426 				n = 1 + (0-t2.tv_sec)/SUPPLY_INTERVAL;
427 				next_bcast.tv_sec += n*SUPPLY_INTERVAL;
428 
429 				continue;
430 			}
431 
432 			if (timercmp(&t2, &wtime, <))
433 				wtime = t2;
434 		}
435 
436 		/* If we need a flash update, either do it now or
437 		 * set the delay to end when it is time.
438 		 *
439 		 * If we are within MIN_WAITTIME seconds of a full update,
440 		 * do not bother.
441 		 */
442 		if (need_flash
443 		    && supplier
444 		    && no_flash.tv_sec+MIN_WAITTIME < next_bcast.tv_sec) {
445 			/* accurate to the millisecond */
446 			if (!timercmp(&no_flash, &now, >))
447 				rip_bcast(1);
448 			timevalsub(&t2, &no_flash, &now);
449 			if (timercmp(&t2, &wtime, <))
450 				wtime = t2;
451 		}
452 
453 		/* trigger the main aging timer.
454 		 */
455 		timevalsub(&t2, &age_timer, &now);
456 		if (t2.tv_sec <= 0) {
457 			age(0);
458 			continue;
459 		}
460 		if (timercmp(&t2, &wtime, <))
461 			wtime = t2;
462 
463 		/* update the kernel routing table
464 		 */
465 		timevalsub(&t2, &need_kern, &now);
466 		if (t2.tv_sec <= 0) {
467 			age(0);
468 			continue;
469 		}
470 		if (timercmp(&t2, &wtime, <))
471 			wtime = t2;
472 
473 		/* take care of router discovery,
474 		 * but do it in the correct the millisecond
475 		 */
476 		if (!timercmp(&rdisc_timer, &now, >)) {
477 			rdisc_age(0);
478 			continue;
479 		}
480 		timevalsub(&t2, &rdisc_timer, &now);
481 		if (timercmp(&t2, &wtime, <))
482 			wtime = t2;
483 
484 
485 		/* wait for input or a timer to expire.
486 		 */
487 		trace_flush();
488 		ibits = fdbits;
489 		n = select(sock_max, &ibits, 0, 0, &wtime);
490 		if (n <= 0) {
491 			if (n < 0 && errno != EINTR && errno != EAGAIN)
492 				BADERR(1,"select");
493 			continue;
494 		}
495 
496 		if (FD_ISSET(rt_sock, &ibits)) {
497 			read_rt();
498 			n--;
499 		}
500 		if (rdisc_sock >= 0 && FD_ISSET(rdisc_sock, &ibits)) {
501 			read_d();
502 			n--;
503 		}
504 		if (rip_sock >= 0 && FD_ISSET(rip_sock, &ibits)) {
505 			read_rip(rip_sock, 0);
506 			n--;
507 		}
508 
509 		LIST_FOREACH(ifp, &ifnet, int_list) {
510 			if (n <= 0)
511 				break;
512 			if (ifp->int_rip_sock >= 0
513 			    && FD_ISSET(ifp->int_rip_sock, &ibits)) {
514 				read_rip(ifp->int_rip_sock, ifp);
515 				n--;
516 			}
517 		}
518 	}
519 }
520 
521 
522 /* ARGSUSED */
523 static void
524 sigalrm(int s UNUSED)
525 {
526 	/* Historically, SIGALRM would cause the daemon to check for
527 	 * new and broken interfaces.
528 	 */
529 	ifinit_timer.tv_sec = now.tv_sec;
530 	trace_act("SIGALRM");
531 }
532 
533 
534 /* watch for fatal signals */
535 static void
536 sigterm(int sig)
537 {
538 	stopint = sig;
539 	(void)signal(sig, SIG_DFL);	/* catch it only once */
540 }
541 
542 
543 void
544 fix_select(void)
545 {
546 	struct interface *ifp;
547 
548 
549 	FD_ZERO(&fdbits);
550 	sock_max = 0;
551 
552 	FD_SET(rt_sock, &fdbits);
553 	if (sock_max <= rt_sock)
554 		sock_max = rt_sock+1;
555 	if (rip_sock >= 0) {
556 		FD_SET(rip_sock, &fdbits);
557 		if (sock_max <= rip_sock)
558 			sock_max = rip_sock+1;
559 	}
560 	LIST_FOREACH(ifp, &ifnet, int_list) {
561 		if (ifp->int_rip_sock >= 0) {
562 			FD_SET(ifp->int_rip_sock, &fdbits);
563 			if (sock_max <= ifp->int_rip_sock)
564 				sock_max = ifp->int_rip_sock+1;
565 		}
566 	}
567 	if (rdisc_sock >= 0) {
568 		FD_SET(rdisc_sock, &fdbits);
569 		if (sock_max <= rdisc_sock)
570 			sock_max = rdisc_sock+1;
571 	}
572 }
573 
574 
575 void
576 fix_sock(int sock,
577 	 const char *name)
578 {
579 	int on;
580 #define MIN_SOCKBUF (4*1024)
581 	static int rbuf;
582 
583 	if (fcntl(sock, F_SETFL, O_NONBLOCK) == -1)
584 		logbad(1, "fcntl(%s) O_NONBLOCK: %s",
585 		       name, strerror(errno));
586 	on = 1;
587 	if (setsockopt(sock, SOL_SOCKET,SO_BROADCAST, &on,sizeof(on)) < 0)
588 		msglog("setsockopt(%s,SO_BROADCAST): %s",
589 		       name, strerror(errno));
590 #ifdef USE_PASSIFNAME
591 	on = 1;
592 	if (setsockopt(sock, SOL_SOCKET, SO_PASSIFNAME, &on,sizeof(on)) < 0)
593 		msglog("setsockopt(%s,SO_PASSIFNAME): %s",
594 		       name, strerror(errno));
595 #endif
596 
597 	if (rbuf >= MIN_SOCKBUF) {
598 		if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
599 			       &rbuf, sizeof(rbuf)) < 0)
600 			msglog("setsockopt(%s,SO_RCVBUF=%d): %s",
601 			       name, rbuf, strerror(errno));
602 	} else {
603 		for (rbuf = 60*1024; ; rbuf -= 4096) {
604 			if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
605 				       &rbuf, sizeof(rbuf)) == 0) {
606 				trace_act("RCVBUF=%d", rbuf);
607 				break;
608 			}
609 			if (rbuf < MIN_SOCKBUF) {
610 				msglog("setsockopt(%s,SO_RCVBUF = %d): %s",
611 				       name, rbuf, strerror(errno));
612 				break;
613 			}
614 		}
615 	}
616 }
617 
618 
619 /* get a rip socket
620  */
621 static int				/* <0 or file descriptor */
622 get_rip_sock(naddr addr,
623 	     int serious)		/* 1=failure to bind is serious */
624 {
625 	struct sockaddr_in rsin;
626 	unsigned char ttl;
627 	int s;
628 
629 
630 	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
631 		BADERR(1,"rip_sock = socket()");
632 
633 	memset(&rsin, 0, sizeof(rsin));
634 #ifdef _HAVE_SIN_LEN
635 	rsin.sin_len = sizeof(rsin);
636 #endif
637 	rsin.sin_family = AF_INET;
638 	rsin.sin_port = htons(RIP_PORT);
639 	rsin.sin_addr.s_addr = addr;
640 	if (bind(s, (struct sockaddr *)&rsin, sizeof(rsin)) < 0) {
641 		if (serious)
642 			BADERR(errno != EADDRINUSE, "bind(rip_sock)");
643 		close(s);
644 		return -1;
645 	}
646 	fix_sock(s,"rip_sock");
647 
648 	ttl = 1;
649 	if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL,
650 		       &ttl, sizeof(ttl)) < 0)
651 		DBGERR(1,"rip_sock setsockopt(IP_MULTICAST_TTL)");
652 
653 	return s;
654 }
655 
656 
657 /* turn off main RIP socket */
658 void
659 rip_off(void)
660 {
661 	struct interface *ifp;
662 	naddr addr;
663 
664 
665 	if (rip_sock >= 0 && !mhome) {
666 		trace_act("turn off RIP");
667 
668 		(void)close(rip_sock);
669 		rip_sock = -1;
670 
671 		/* get non-broadcast sockets to listen to queries.
672 		 */
673 		LIST_FOREACH(ifp, &ifnet, int_list) {
674 			if (ifp->int_state & IS_REMOTE)
675 				continue;
676 			if (ifp->int_rip_sock < 0) {
677 				addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
678 					? ifp->int_dstaddr
679 					: ifp->int_addr);
680 				ifp->int_rip_sock = get_rip_sock(addr, 0);
681 			}
682 		}
683 
684 		fix_select();
685 
686 		age(0);
687 	}
688 }
689 
690 
691 /* turn on RIP multicast input via an interface
692  */
693 static void
694 rip_mcast_on(struct interface *ifp)
695 {
696 	struct group_req gr;
697 	struct sockaddr_in *sin;
698 
699 	if (!IS_RIP_IN_OFF(ifp->int_state)
700 	    && (ifp->int_if_flags & IFF_MULTICAST)
701 	    && !(ifp->int_state & IS_ALIAS)) {
702 		memset(&gr, 0, sizeof(gr));
703 		gr.gr_interface = ifp->int_index;
704 		sin = (struct sockaddr_in *)&gr.gr_group;
705 		sin->sin_family = AF_INET;
706 #ifdef _HAVE_SIN_LEN
707 		sin->sin_len = sizeof(struct sockaddr_in);
708 #endif
709 		sin->sin_addr.s_addr = htonl(INADDR_RIP_GROUP);
710 		if (setsockopt(rip_sock, IPPROTO_IP, MCAST_JOIN_GROUP,
711 			       &gr, sizeof(gr)) < 0)
712 			LOGERR("setsockopt(MCAST_JOIN_GROUP RIP)");
713 	}
714 }
715 
716 
717 /* Prepare socket used for RIP.
718  */
719 void
720 rip_on(struct interface *ifp)
721 {
722 	/* If the main RIP socket is already alive, only start receiving
723 	 * multicasts for this interface.
724 	 */
725 	if (rip_sock >= 0) {
726 		if (ifp != NULL)
727 			rip_mcast_on(ifp);
728 		return;
729 	}
730 
731 	/* If the main RIP socket is off and it makes sense to turn it on,
732 	 * then turn it on for all of the interfaces.
733 	 * It makes sense if either router discovery is off, or if
734 	 * router discover is on and at most one interface is doing RIP.
735 	 */
736 	if (rip_interfaces > 0 && (!rdisc_ok || rip_interfaces > 1)) {
737 		trace_act("turn on RIP");
738 
739 		/* Close all of the query sockets so that we can open
740 		 * the main socket.  SO_REUSEPORT is not a solution,
741 		 * since that would let two daemons bind to the broadcast
742 		 * socket.
743 		 */
744 		LIST_FOREACH(ifp, &ifnet, int_list) {
745 			if (ifp->int_rip_sock >= 0) {
746 				(void)close(ifp->int_rip_sock);
747 				ifp->int_rip_sock = -1;
748 			}
749 		}
750 
751 		rip_sock = get_rip_sock(INADDR_ANY, 1);
752 		rip_sock_mcast = NULL;
753 
754 		/* Do not advertise anything until we have heard something
755 		 */
756 		if (next_bcast.tv_sec < now.tv_sec+MIN_WAITTIME)
757 			next_bcast.tv_sec = now.tv_sec+MIN_WAITTIME;
758 
759 		LIST_FOREACH(ifp, &ifnet, int_list) {
760 			ifp->int_query_time = NEVER;
761 			rip_mcast_on(ifp);
762 		}
763 		ifinit_timer.tv_sec = now.tv_sec;
764 
765 	} else if (ifp != NULL
766 		   && !(ifp->int_state & IS_REMOTE)
767 		   && ifp->int_rip_sock < 0) {
768 		/* RIP is off, so ensure there are sockets on which
769 		 * to listen for queries.
770 		 */
771 		ifp->int_rip_sock = get_rip_sock(ifp->int_addr, 0);
772 	}
773 
774 	fix_select();
775 }
776 
777 
778 /* die if malloc(3) fails
779  */
780 void *
781 rtmalloc(size_t size,
782 	 const char *msg)
783 {
784 	void *p = malloc(size);
785 	if (p == NULL)
786 		logbad(1,"malloc(%lu) failed in %s", (u_long)size, msg);
787 	return p;
788 }
789 
790 
791 /* get a random instant in an interval
792  */
793 void
794 intvl_random(struct timeval *tp,	/* put value here */
795 	     u_long lo,			/* value is after this second */
796 	     u_long hi)			/* and before this */
797 {
798 	tp->tv_sec = (time_t)(hi == lo
799 			      ? lo
800 			      : (lo + arc4random_uniform(1 + hi - lo)));
801 	tp->tv_usec = arc4random_uniform(1000000);
802 }
803 
804 
805 void
806 timevaladd(struct timeval *t1,
807 	   struct timeval *t2)
808 {
809 
810 	t1->tv_sec += t2->tv_sec;
811 	if ((t1->tv_usec += t2->tv_usec) >= 1000000) {
812 		t1->tv_sec++;
813 		t1->tv_usec -= 1000000;
814 	}
815 }
816 
817 
818 /* t1 = t2 - t3
819  */
820 static void
821 timevalsub(struct timeval *t1,
822 	   struct timeval *t2,
823 	   struct timeval *t3)
824 {
825 	t1->tv_sec = t2->tv_sec - t3->tv_sec;
826 	if ((t1->tv_usec = t2->tv_usec - t3->tv_usec) < 0) {
827 		t1->tv_sec--;
828 		t1->tv_usec += 1000000;
829 	}
830 }
831 
832 
833 /* put a message into the system log
834  */
835 void
836 msglog(const char *p, ...)
837 {
838 	va_list args;
839 
840 	trace_flush();
841 
842 	va_start(args, p);
843 	vsyslog(LOG_ERR, p, args);
844 	va_end(args);
845 	if (ftrace != NULL) {
846 		if (ftrace == stdout)
847 			(void)fputs("routed: ", ftrace);
848 		va_start(args, p);
849 		(void)vfprintf(ftrace, p, args);
850 		va_end(args);
851 		(void)fputc('\n', ftrace);
852 	}
853 }
854 
855 
856 /* Put a message about a bad system into the system log if
857  * we have not complained about it recently.
858  *
859  * It is desirable to complain about all bad systems, but not too often.
860  * In the worst case, it is not practical to keep track of all bad systems.
861  * For example, there can be many systems with the wrong password.
862  */
863 void
864 msglim(struct msg_limit *lim, naddr addr, const char *p, ...)
865 {
866 	va_list args;
867 	int i;
868 	struct msg_sub *ms1, *ms;
869 	const char *p1;
870 
871 	/* look for the oldest slot in the table
872 	 * or the slot for the bad router.
873 	 */
874 	ms = ms1 = lim->subs;
875 	for (i = MSG_SUBJECT_N; ; i--, ms1++) {
876 		if (i == 0) {
877 			/* Reuse a slot at most once every 10 minutes.
878 			 */
879 			if (lim->reuse > now.tv_sec) {
880 				ms = NULL;
881 			} else {
882 				ms = ms1;
883 				lim->reuse = now.tv_sec + 10*60;
884 			}
885 			break;
886 		}
887 		if (ms->addr == addr) {
888 			/* Repeat a complaint about a given system at
889 			 * most once an hour.
890 			 */
891 			if (ms->until > now.tv_sec)
892 				ms = NULL;
893 			break;
894 		}
895 		if (ms->until < ms1->until)
896 			ms = ms1;
897 	}
898 	if (ms != NULL) {
899 		ms->addr = addr;
900 		ms->until = now.tv_sec + 60*60;	/* 60 minutes */
901 
902 		trace_flush();
903 		for (p1 = p; *p1 == ' '; p1++)
904 			continue;
905 		va_start(args, p);
906 		vsyslog(LOG_ERR, p1, args);
907 		va_end(args);
908 	}
909 
910 	/* always display the message if tracing */
911 	if (ftrace != NULL) {
912 		va_start(args, p);
913 		(void)vfprintf(ftrace, p, args);
914 		va_end(args);
915 		(void)fputc('\n', ftrace);
916 	}
917 }
918 
919 
920 void
921 logbad(int dump, const char *p, ...)
922 {
923 	va_list args;
924 
925 	trace_flush();
926 
927 	va_start(args, p);
928 	vsyslog(LOG_ERR, p, args);
929 	va_end(args);
930 	(void)fputs("routed: ", stderr);
931 	va_start(args, p);
932 	(void)vfprintf(stderr, p, args);
933 	va_end(args);
934 	(void)fputs("; giving up\n",stderr);
935 	(void)fflush(stderr);
936 
937 	if (dump)
938 		abort();
939 	exit(1);
940 }
941