xref: /freebsd/sbin/routed/main.c (revision bc96366c864c07ef352edb92017357917c75b36c)
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 #ifdef __FreeBSD__
307 	srandomdev();
308 #else
309 	srandom((int)(clk.tv_sec ^ clk.tv_usec ^ mypid));
310 #endif
311 
312 	/* prepare socket connected to the kernel.
313 	 */
314 	rt_sock = socket(AF_ROUTE, SOCK_RAW, 0);
315 	if (rt_sock < 0)
316 		BADERR(1,"rt_sock = socket()");
317 	if (fcntl(rt_sock, F_SETFL, O_NONBLOCK) == -1)
318 		logbad(1, "fcntl(rt_sock) O_NONBLOCK: %s", strerror(errno));
319 	off = 0;
320 	if (setsockopt(rt_sock, SOL_SOCKET,SO_USELOOPBACK,
321 		       &off,sizeof(off)) < 0)
322 		LOGERR("setsockopt(SO_USELOOPBACK,0)");
323 
324 	fix_select();
325 
326 
327 	if (tracename != 0) {
328 		strncpy(inittracename, tracename, sizeof(inittracename)-1);
329 		set_tracefile(inittracename, "%s", -1);
330 	} else {
331 		tracelevel_msg("%s", -1);   /* turn on tracing to stdio */
332 	}
333 
334 	bufinit();
335 
336 	/* initialize radix tree */
337 	rtinit();
338 
339 	/* Pick a random part of the second for our output to minimize
340 	 * collisions.
341 	 *
342 	 * Start broadcasting after hearing from other routers, and
343 	 * at a random time so a bunch of systems do not get synchronized
344 	 * after a power failure.
345 	 */
346 	intvl_random(&next_bcast, EPOCH+MIN_WAITTIME, EPOCH+SUPPLY_INTERVAL);
347 	age_timer.tv_usec = next_bcast.tv_usec;
348 	age_timer.tv_sec = EPOCH+MIN_WAITTIME;
349 	rdisc_timer = next_bcast;
350 	ifinit_timer.tv_usec = next_bcast.tv_usec;
351 
352 	/* Collect an initial view of the world by checking the interface
353 	 * configuration and the kludge file.
354 	 */
355 	gwkludge();
356 	ifinit();
357 
358 	/* Ask for routes */
359 	rip_query();
360 	rdisc_sol();
361 
362 	/* Now turn off stdio if not tracing */
363 	if (new_tracelevel == 0)
364 		trace_close(background);
365 
366 	/* Loop forever, listening and broadcasting.
367 	 */
368 	for (;;) {
369 		prev_clk = clk;
370 		gettimeofday(&clk, 0);
371 		if (prev_clk.tv_sec == clk.tv_sec
372 		    && prev_clk.tv_usec == clk.tv_usec+usec_fudge) {
373 			/* Much of `routed` depends on time always advancing.
374 			 * On systems that do not guarantee that gettimeofday()
375 			 * produces unique timestamps even if called within
376 			 * a single tick, use trickery like that in classic
377 			 * BSD kernels.
378 			 */
379 			clk.tv_usec += ++usec_fudge;
380 
381 		} else {
382 			usec_fudge = 0;
383 
384 			timevalsub(&t2, &clk, &prev_clk);
385 			if (t2.tv_sec < 0
386 			    || t2.tv_sec > wtime.tv_sec + 5) {
387 				/* Deal with time changes before other
388 				 * housekeeping to keep everything straight.
389 				 */
390 				dt = t2.tv_sec;
391 				if (dt > 0)
392 					dt -= wtime.tv_sec;
393 				trace_act("time changed by %d sec", (int)dt);
394 				epoch.tv_sec += dt;
395 			}
396 		}
397 		timevalsub(&now, &clk, &epoch);
398 		now_stale = now.tv_sec - STALE_TIME;
399 		now_expire = now.tv_sec - EXPIRE_TIME;
400 		now_garbage = now.tv_sec - GARBAGE_TIME;
401 
402 		/* deal with signals that should affect tracing */
403 		set_tracelevel();
404 
405 		if (stopint != 0) {
406 			rip_bcast(0);
407 			rdisc_adv();
408 			trace_off("exiting with signal %d", stopint);
409 			exit(stopint | 128);
410 		}
411 
412 		/* look for new or dead interfaces */
413 		timevalsub(&wtime, &ifinit_timer, &now);
414 		if (wtime.tv_sec <= 0) {
415 			wtime.tv_sec = 0;
416 			ifinit();
417 			rip_query();
418 			continue;
419 		}
420 
421 		/* Check the kernel table occasionally for mysteriously
422 		 * evaporated routes
423 		 */
424 		timevalsub(&t2, &flush_kern_timer, &now);
425 		if (t2.tv_sec <= 0) {
426 			flush_kern();
427 			flush_kern_timer.tv_sec = (now.tv_sec
428 						   + CHECK_QUIET_INTERVAL);
429 			continue;
430 		}
431 		if (timercmp(&t2, &wtime, <))
432 			wtime = t2;
433 
434 		/* If it is time, then broadcast our routes.
435 		 */
436 		if (supplier || advertise_mhome) {
437 			timevalsub(&t2, &next_bcast, &now);
438 			if (t2.tv_sec <= 0) {
439 				/* Synchronize the aging and broadcast
440 				 * timers to minimize awakenings
441 				 */
442 				age(0);
443 
444 				rip_bcast(0);
445 
446 				/* It is desirable to send routing updates
447 				 * regularly.  So schedule the next update
448 				 * 30 seconds after the previous one was
449 				 * scheduled, instead of 30 seconds after
450 				 * the previous update was finished.
451 				 * Even if we just started after discovering
452 				 * a 2nd interface or were otherwise delayed,
453 				 * pick a 30-second anniversary of the
454 				 * original broadcast time.
455 				 */
456 				n = 1 + (0-t2.tv_sec)/SUPPLY_INTERVAL;
457 				next_bcast.tv_sec += n*SUPPLY_INTERVAL;
458 
459 				continue;
460 			}
461 
462 			if (timercmp(&t2, &wtime, <))
463 				wtime = t2;
464 		}
465 
466 		/* If we need a flash update, either do it now or
467 		 * set the delay to end when it is time.
468 		 *
469 		 * If we are within MIN_WAITTIME seconds of a full update,
470 		 * do not bother.
471 		 */
472 		if (need_flash
473 		    && supplier
474 		    && no_flash.tv_sec+MIN_WAITTIME < next_bcast.tv_sec) {
475 			/* accurate to the millisecond */
476 			if (!timercmp(&no_flash, &now, >))
477 				rip_bcast(1);
478 			timevalsub(&t2, &no_flash, &now);
479 			if (timercmp(&t2, &wtime, <))
480 				wtime = t2;
481 		}
482 
483 		/* trigger the main aging timer.
484 		 */
485 		timevalsub(&t2, &age_timer, &now);
486 		if (t2.tv_sec <= 0) {
487 			age(0);
488 			continue;
489 		}
490 		if (timercmp(&t2, &wtime, <))
491 			wtime = t2;
492 
493 		/* update the kernel routing table
494 		 */
495 		timevalsub(&t2, &need_kern, &now);
496 		if (t2.tv_sec <= 0) {
497 			age(0);
498 			continue;
499 		}
500 		if (timercmp(&t2, &wtime, <))
501 			wtime = t2;
502 
503 		/* take care of router discovery,
504 		 * but do it in the correct the millisecond
505 		 */
506 		if (!timercmp(&rdisc_timer, &now, >)) {
507 			rdisc_age(0);
508 			continue;
509 		}
510 		timevalsub(&t2, &rdisc_timer, &now);
511 		if (timercmp(&t2, &wtime, <))
512 			wtime = t2;
513 
514 
515 		/* wait for input or a timer to expire.
516 		 */
517 		trace_flush();
518 		ibits = fdbits;
519 		n = select(sock_max, &ibits, 0, 0, &wtime);
520 		if (n <= 0) {
521 			if (n < 0 && errno != EINTR && errno != EAGAIN)
522 				BADERR(1,"select");
523 			continue;
524 		}
525 
526 		if (FD_ISSET(rt_sock, &ibits)) {
527 			read_rt();
528 			n--;
529 		}
530 		if (rdisc_sock >= 0 && FD_ISSET(rdisc_sock, &ibits)) {
531 			read_d();
532 			n--;
533 		}
534 		if (rip_sock >= 0 && FD_ISSET(rip_sock, &ibits)) {
535 			read_rip(rip_sock, 0);
536 			n--;
537 		}
538 
539 		LIST_FOREACH(ifp, &ifnet, int_list) {
540 			if (n <= 0)
541 				break;
542 			if (ifp->int_rip_sock >= 0
543 			    && FD_ISSET(ifp->int_rip_sock, &ibits)) {
544 				read_rip(ifp->int_rip_sock, ifp);
545 				n--;
546 			}
547 		}
548 	}
549 }
550 
551 
552 /* ARGSUSED */
553 static void
554 sigalrm(int s UNUSED)
555 {
556 	/* Historically, SIGALRM would cause the daemon to check for
557 	 * new and broken interfaces.
558 	 */
559 	ifinit_timer.tv_sec = now.tv_sec;
560 	trace_act("SIGALRM");
561 }
562 
563 
564 /* watch for fatal signals */
565 static void
566 sigterm(int sig)
567 {
568 	stopint = sig;
569 	(void)signal(sig, SIG_DFL);	/* catch it only once */
570 }
571 
572 
573 void
574 fix_select(void)
575 {
576 	struct interface *ifp;
577 
578 
579 	FD_ZERO(&fdbits);
580 	sock_max = 0;
581 
582 	FD_SET(rt_sock, &fdbits);
583 	if (sock_max <= rt_sock)
584 		sock_max = rt_sock+1;
585 	if (rip_sock >= 0) {
586 		FD_SET(rip_sock, &fdbits);
587 		if (sock_max <= rip_sock)
588 			sock_max = rip_sock+1;
589 	}
590 	LIST_FOREACH(ifp, &ifnet, int_list) {
591 		if (ifp->int_rip_sock >= 0) {
592 			FD_SET(ifp->int_rip_sock, &fdbits);
593 			if (sock_max <= ifp->int_rip_sock)
594 				sock_max = ifp->int_rip_sock+1;
595 		}
596 	}
597 	if (rdisc_sock >= 0) {
598 		FD_SET(rdisc_sock, &fdbits);
599 		if (sock_max <= rdisc_sock)
600 			sock_max = rdisc_sock+1;
601 	}
602 }
603 
604 
605 void
606 fix_sock(int sock,
607 	 const char *name)
608 {
609 	int on;
610 #define MIN_SOCKBUF (4*1024)
611 	static int rbuf;
612 
613 	if (fcntl(sock, F_SETFL, O_NONBLOCK) == -1)
614 		logbad(1, "fcntl(%s) O_NONBLOCK: %s",
615 		       name, strerror(errno));
616 	on = 1;
617 	if (setsockopt(sock, SOL_SOCKET,SO_BROADCAST, &on,sizeof(on)) < 0)
618 		msglog("setsockopt(%s,SO_BROADCAST): %s",
619 		       name, strerror(errno));
620 #ifdef USE_PASSIFNAME
621 	on = 1;
622 	if (setsockopt(sock, SOL_SOCKET, SO_PASSIFNAME, &on,sizeof(on)) < 0)
623 		msglog("setsockopt(%s,SO_PASSIFNAME): %s",
624 		       name, strerror(errno));
625 #endif
626 
627 	if (rbuf >= MIN_SOCKBUF) {
628 		if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
629 			       &rbuf, sizeof(rbuf)) < 0)
630 			msglog("setsockopt(%s,SO_RCVBUF=%d): %s",
631 			       name, rbuf, strerror(errno));
632 	} else {
633 		for (rbuf = 60*1024; ; rbuf -= 4096) {
634 			if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
635 				       &rbuf, sizeof(rbuf)) == 0) {
636 				trace_act("RCVBUF=%d", rbuf);
637 				break;
638 			}
639 			if (rbuf < MIN_SOCKBUF) {
640 				msglog("setsockopt(%s,SO_RCVBUF = %d): %s",
641 				       name, rbuf, strerror(errno));
642 				break;
643 			}
644 		}
645 	}
646 }
647 
648 
649 /* get a rip socket
650  */
651 static int				/* <0 or file descriptor */
652 get_rip_sock(naddr addr,
653 	     int serious)		/* 1=failure to bind is serious */
654 {
655 	struct sockaddr_in rsin;
656 	unsigned char ttl;
657 	int s;
658 
659 
660 	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
661 		BADERR(1,"rip_sock = socket()");
662 
663 	memset(&rsin, 0, sizeof(rsin));
664 #ifdef _HAVE_SIN_LEN
665 	rsin.sin_len = sizeof(rsin);
666 #endif
667 	rsin.sin_family = AF_INET;
668 	rsin.sin_port = htons(RIP_PORT);
669 	rsin.sin_addr.s_addr = addr;
670 	if (bind(s, (struct sockaddr *)&rsin, sizeof(rsin)) < 0) {
671 		if (serious)
672 			BADERR(errno != EADDRINUSE, "bind(rip_sock)");
673 		return -1;
674 	}
675 	fix_sock(s,"rip_sock");
676 
677 	ttl = 1;
678 	if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL,
679 		       &ttl, sizeof(ttl)) < 0)
680 		DBGERR(1,"rip_sock setsockopt(IP_MULTICAST_TTL)");
681 
682 	return s;
683 }
684 
685 
686 /* turn off main RIP socket */
687 void
688 rip_off(void)
689 {
690 	struct interface *ifp;
691 	naddr addr;
692 
693 
694 	if (rip_sock >= 0 && !mhome) {
695 		trace_act("turn off RIP");
696 
697 		(void)close(rip_sock);
698 		rip_sock = -1;
699 
700 		/* get non-broadcast sockets to listen to queries.
701 		 */
702 		LIST_FOREACH(ifp, &ifnet, int_list) {
703 			if (ifp->int_state & IS_REMOTE)
704 				continue;
705 			if (ifp->int_rip_sock < 0) {
706 				addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
707 					? ifp->int_dstaddr
708 					: ifp->int_addr);
709 				ifp->int_rip_sock = get_rip_sock(addr, 0);
710 			}
711 		}
712 
713 		fix_select();
714 
715 		age(0);
716 	}
717 }
718 
719 
720 /* turn on RIP multicast input via an interface
721  */
722 static void
723 rip_mcast_on(struct interface *ifp)
724 {
725 	struct group_req gr;
726 	struct sockaddr_in *sin;
727 
728 	if (!IS_RIP_IN_OFF(ifp->int_state)
729 	    && (ifp->int_if_flags & IFF_MULTICAST)
730 	    && !(ifp->int_state & IS_ALIAS)) {
731 		memset(&gr, 0, sizeof(gr));
732 		gr.gr_interface = ifp->int_index;
733 		sin = (struct sockaddr_in *)&gr.gr_group;
734 		sin->sin_family = AF_INET;
735 #ifdef _HAVE_SIN_LEN
736 		sin->sin_len = sizeof(struct sockaddr_in);
737 #endif
738 		sin->sin_addr.s_addr = htonl(INADDR_RIP_GROUP);
739 		if (setsockopt(rip_sock, IPPROTO_IP, MCAST_JOIN_GROUP,
740 			       &gr, sizeof(gr)) < 0)
741 			LOGERR("setsockopt(MCAST_JOIN_GROUP RIP)");
742 	}
743 }
744 
745 
746 /* Prepare socket used for RIP.
747  */
748 void
749 rip_on(struct interface *ifp)
750 {
751 	/* If the main RIP socket is already alive, only start receiving
752 	 * multicasts for this interface.
753 	 */
754 	if (rip_sock >= 0) {
755 		if (ifp != 0)
756 			rip_mcast_on(ifp);
757 		return;
758 	}
759 
760 	/* If the main RIP socket is off and it makes sense to turn it on,
761 	 * then turn it on for all of the interfaces.
762 	 * It makes sense if either router discovery is off, or if
763 	 * router discover is on and at most one interface is doing RIP.
764 	 */
765 	if (rip_interfaces > 0 && (!rdisc_ok || rip_interfaces > 1)) {
766 		trace_act("turn on RIP");
767 
768 		/* Close all of the query sockets so that we can open
769 		 * the main socket.  SO_REUSEPORT is not a solution,
770 		 * since that would let two daemons bind to the broadcast
771 		 * socket.
772 		 */
773 		LIST_FOREACH(ifp, &ifnet, int_list) {
774 			if (ifp->int_rip_sock >= 0) {
775 				(void)close(ifp->int_rip_sock);
776 				ifp->int_rip_sock = -1;
777 			}
778 		}
779 
780 		rip_sock = get_rip_sock(INADDR_ANY, 1);
781 		rip_sock_mcast = 0;
782 
783 		/* Do not advertise anything until we have heard something
784 		 */
785 		if (next_bcast.tv_sec < now.tv_sec+MIN_WAITTIME)
786 			next_bcast.tv_sec = now.tv_sec+MIN_WAITTIME;
787 
788 		LIST_FOREACH(ifp, &ifnet, int_list) {
789 			ifp->int_query_time = NEVER;
790 			rip_mcast_on(ifp);
791 		}
792 		ifinit_timer.tv_sec = now.tv_sec;
793 
794 	} else if (ifp != 0
795 		   && !(ifp->int_state & IS_REMOTE)
796 		   && ifp->int_rip_sock < 0) {
797 		/* RIP is off, so ensure there are sockets on which
798 		 * to listen for queries.
799 		 */
800 		ifp->int_rip_sock = get_rip_sock(ifp->int_addr, 0);
801 	}
802 
803 	fix_select();
804 }
805 
806 
807 /* die if malloc(3) fails
808  */
809 void *
810 rtmalloc(size_t size,
811 	 const char *msg)
812 {
813 	void *p = malloc(size);
814 	if (p == 0)
815 		logbad(1,"malloc(%lu) failed in %s", (u_long)size, msg);
816 	return p;
817 }
818 
819 
820 /* get a random instant in an interval
821  */
822 void
823 intvl_random(struct timeval *tp,	/* put value here */
824 	     u_long lo,			/* value is after this second */
825 	     u_long hi)			/* and before this */
826 {
827 	tp->tv_sec = (time_t)(hi == lo
828 			      ? lo
829 			      : (lo + random() % ((hi - lo))));
830 	tp->tv_usec = random() % 1000000;
831 }
832 
833 
834 void
835 timevaladd(struct timeval *t1,
836 	   struct timeval *t2)
837 {
838 
839 	t1->tv_sec += t2->tv_sec;
840 	if ((t1->tv_usec += t2->tv_usec) >= 1000000) {
841 		t1->tv_sec++;
842 		t1->tv_usec -= 1000000;
843 	}
844 }
845 
846 
847 /* t1 = t2 - t3
848  */
849 static void
850 timevalsub(struct timeval *t1,
851 	   struct timeval *t2,
852 	   struct timeval *t3)
853 {
854 	t1->tv_sec = t2->tv_sec - t3->tv_sec;
855 	if ((t1->tv_usec = t2->tv_usec - t3->tv_usec) < 0) {
856 		t1->tv_sec--;
857 		t1->tv_usec += 1000000;
858 	}
859 }
860 
861 
862 /* put a message into the system log
863  */
864 void
865 msglog(const char *p, ...)
866 {
867 	va_list args;
868 
869 	trace_flush();
870 
871 	va_start(args, p);
872 	vsyslog(LOG_ERR, p, args);
873 	va_end(args);
874 	if (ftrace != 0) {
875 		if (ftrace == stdout)
876 			(void)fputs("routed: ", ftrace);
877 		va_start(args, p);
878 		(void)vfprintf(ftrace, p, args);
879 		va_end(args);
880 		(void)fputc('\n', ftrace);
881 	}
882 }
883 
884 
885 /* Put a message about a bad system into the system log if
886  * we have not complained about it recently.
887  *
888  * It is desirable to complain about all bad systems, but not too often.
889  * In the worst case, it is not practical to keep track of all bad systems.
890  * For example, there can be many systems with the wrong password.
891  */
892 void
893 msglim(struct msg_limit *lim, naddr addr, const char *p, ...)
894 {
895 	va_list args;
896 	int i;
897 	struct msg_sub *ms1, *ms;
898 	const char *p1;
899 
900 	/* look for the oldest slot in the table
901 	 * or the slot for the bad router.
902 	 */
903 	ms = ms1 = lim->subs;
904 	for (i = MSG_SUBJECT_N; ; i--, ms1++) {
905 		if (i == 0) {
906 			/* Reuse a slot at most once every 10 minutes.
907 			 */
908 			if (lim->reuse > now.tv_sec) {
909 				ms = 0;
910 			} else {
911 				ms = ms1;
912 				lim->reuse = now.tv_sec + 10*60;
913 			}
914 			break;
915 		}
916 		if (ms->addr == addr) {
917 			/* Repeat a complaint about a given system at
918 			 * most once an hour.
919 			 */
920 			if (ms->until > now.tv_sec)
921 				ms = 0;
922 			break;
923 		}
924 		if (ms->until < ms1->until)
925 			ms = ms1;
926 	}
927 	if (ms != 0) {
928 		ms->addr = addr;
929 		ms->until = now.tv_sec + 60*60;	/* 60 minutes */
930 
931 		trace_flush();
932 		for (p1 = p; *p1 == ' '; p1++)
933 			continue;
934 		va_start(args, p);
935 		vsyslog(LOG_ERR, p1, args);
936 		va_end(args);
937 	}
938 
939 	/* always display the message if tracing */
940 	if (ftrace != 0) {
941 		va_start(args, p);
942 		(void)vfprintf(ftrace, p, args);
943 		va_end(args);
944 		(void)fputc('\n', ftrace);
945 	}
946 }
947 
948 
949 void
950 logbad(int dump, const char *p, ...)
951 {
952 	va_list args;
953 
954 	trace_flush();
955 
956 	va_start(args, p);
957 	vsyslog(LOG_ERR, p, args);
958 	va_end(args);
959 	(void)fputs("routed: ", stderr);
960 	va_start(args, p);
961 	(void)vfprintf(stderr, p, args);
962 	va_end(args);
963 	(void)fputs("; giving up\n",stderr);
964 	(void)fflush(stderr);
965 
966 	if (dump)
967 		abort();
968 	exit(1);
969 }
970