xref: /dragonfly/sbin/routed/main.c (revision 44753b81)
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  * 3. 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: src/sbin/routed/main.c,v 1.11.2.1 2000/08/14 17:00:03 sheldonh Exp $
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 #if !defined(sgi) && !defined(__NetBSD__)
42 char copyright[] =
43 "@(#) Copyright (c) 1983, 1988, 1993\n\
44 	The Regents of the University of California.  All rights reserved.\n";
45 static char sccsid[] __attribute__((unused)) = "@(#)main.c	8.1 (Berkeley) 6/5/93";
46 #elif defined(__NetBSD__)
47 __RCSID("$NetBSD$");
48 __COPYRIGHT("@(#) Copyright (c) 1983, 1988, 1993\n\
49 	The Regents of the University of California.  All rights reserved.\n");
50 #endif
51 
52 
53 pid_t	mypid;
54 
55 naddr	myaddr;				/* system address */
56 char	myname[MAXHOSTNAMELEN+1];
57 
58 int	verbose;
59 
60 int	supplier;			/* supply or broadcast updates */
61 int	supplier_set;
62 int	ipforwarding = 1;		/* kernel forwarding on */
63 
64 int	default_gateway;		/* 1=advertise default */
65 int	background = 1;
66 int	ridhosts;			/* 1=reduce host routes */
67 int	mhome;				/* 1=want multi-homed host route */
68 int	advertise_mhome;		/* 1=must continue advertising it */
69 int	auth_ok = 1;			/* 1=ignore auth if we do not care */
70 
71 struct timeval epoch;			/* when started */
72 struct timeval clk, prev_clk;
73 static int usec_fudge;
74 struct timeval now;			/* current idea of time */
75 time_t	now_stale;
76 time_t	now_expire;
77 time_t	now_garbage;
78 
79 struct timeval next_bcast;		/* next general broadcast */
80 struct timeval no_flash = {		/* inhibit flash update */
81 	EPOCH+SUPPLY_INTERVAL, 0
82 };
83 
84 struct timeval flush_kern_timer;
85 
86 fd_set	fdbits;
87 int	sock_max;
88 int	rip_sock = -1;			/* RIP socket */
89 struct interface *rip_sock_mcast;	/* current multicast interface */
90 int	rt_sock;			/* routing socket */
91 int	rt_sock_seqno;
92 
93 
94 static  int get_rip_sock(naddr, int);
95 static void timevalsub(struct timeval *, struct timeval *, struct timeval *);
96 
97 int
98 main(int argc,
99      char *argv[])
100 {
101 	int n, mib[4], off;
102 	size_t len;
103 	char *p, *q;
104 	const char *cp;
105 	struct timeval wtime, t2;
106 	time_t dt;
107 	fd_set ibits;
108 	naddr p_net, p_mask;
109 	struct interface *ifp;
110 	struct parm parm;
111 	char *tracename = 0;
112 
113 
114 	/* Some shells are badly broken and send SIGHUP to backgrounded
115 	 * processes.
116 	 */
117 	signal(SIGHUP, SIG_IGN);
118 
119 	openlog("routed", LOG_PID | LOG_ODELAY, LOG_DAEMON);
120 	ftrace = stdout;
121 
122 	gettimeofday(&clk, 0);
123 	prev_clk = clk;
124 	epoch = clk;
125 	epoch.tv_sec -= EPOCH;
126 	now.tv_sec = EPOCH;
127 	now_stale = EPOCH - STALE_TIME;
128 	now_expire = EPOCH - EXPIRE_TIME;
129 	now_garbage = EPOCH - GARBAGE_TIME;
130 	wtime.tv_sec = 0;
131 
132 	gethostname(myname, sizeof(myname)-1);
133 	gethost(myname, &myaddr);
134 
135 	while ((n = getopt(argc, argv, "sqdghmpAtvT:F:P:")) != -1) {
136 		switch (n) {
137 		case 's':
138 			supplier = 1;
139 			supplier_set = 1;
140 			break;
141 
142 		case 'q':
143 			supplier = 0;
144 			supplier_set = 1;
145 			break;
146 
147 		case 'd':
148 			background = 0;
149 			break;
150 
151 		case 'g':
152 			memset(&parm, 0, sizeof(parm));
153 			parm.parm_d_metric = 1;
154 			cp = check_parms(&parm);
155 			if (cp != 0)
156 				msglog("bad -g: %s", cp);
157 			else
158 				default_gateway = 1;
159 			break;
160 
161 		case 'h':		/* suppress extra host routes */
162 			ridhosts = 1;
163 			break;
164 
165 		case 'm':		/* advertise host route */
166 			mhome = 1;	/* on multi-homed hosts */
167 			break;
168 
169 		case 'A':
170 			/* Ignore authentication if we do not care.
171 			 * Crazy as it is, that is what RFC 1723 requires.
172 			 */
173 			auth_ok = 0;
174 			break;
175 
176 		case 't':
177 			new_tracelevel++;
178 			break;
179 
180 		case 'T':
181 			tracename = optarg;
182 			break;
183 
184 		case 'F':		/* minimal routes for SLIP */
185 			n = FAKE_METRIC;
186 			p = strchr(optarg,',');
187 			if (p && *p != '\0') {
188 				n = (int)strtoul(p+1, &q, 0);
189 				if (*q == '\0'
190 				    && n <= HOPCNT_INFINITY-1
191 				    && n >= 1)
192 					*p = '\0';
193 			}
194 			if (!getnet(optarg, &p_net, &p_mask)) {
195 				msglog("bad network; \"-F %s\"",
196 				       optarg);
197 				break;
198 			}
199 			memset(&parm, 0, sizeof(parm));
200 			parm.parm_net = p_net;
201 			parm.parm_mask = p_mask;
202 			parm.parm_d_metric = n;
203 			cp = check_parms(&parm);
204 			if (cp != 0)
205 				msglog("bad -F: %s", cp);
206 			break;
207 
208 		case 'P':
209 			/* handle arbitrary parameters.
210 			 */
211 			q = strdup(optarg);
212 			cp = parse_parms(q, 0);
213 			if (cp != 0)
214 				msglog("%s in \"-P %s\"", cp, optarg);
215 			free(q);
216 			break;
217 
218 		case 'v':
219 			/* display version */
220 			verbose++;
221 			msglog("version 2.22");
222 			break;
223 
224 		default:
225 			goto usage;
226 		}
227 	}
228 	argc -= optind;
229 	argv += optind;
230 
231 	if (tracename == 0 && argc >= 1) {
232 		tracename = *argv++;
233 		argc--;
234 	}
235 	if (tracename != 0 && tracename[0] == '\0')
236 		goto usage;
237 	if (argc != 0) {
238 usage:
239 		logbad(0, "usage: routed [-sqdghmpAtv] [-T tracefile]"
240 		       " [-F net[,metric]] [-P parms]");
241 	}
242 	if (geteuid() != 0) {
243 		if (verbose)
244 			exit(0);
245 		logbad(0, "requires UID 0");
246 	}
247 
248 	mib[0] = CTL_NET;
249 	mib[1] = PF_INET;
250 	mib[2] = IPPROTO_IP;
251 	mib[3] = IPCTL_FORWARDING;
252 	len = sizeof(ipforwarding);
253 	if (sysctl(mib, 4, &ipforwarding, &len, 0, 0) < 0)
254 		LOGERR("sysctl(IPCTL_FORWARDING)");
255 
256 	if (!ipforwarding) {
257 		if (supplier)
258 			msglog("-s incompatible with ipforwarding=0");
259 		if (default_gateway) {
260 			msglog("-g incompatible with ipforwarding=0");
261 			default_gateway = 0;
262 		}
263 		supplier = 0;
264 		supplier_set = 1;
265 	}
266 	if (default_gateway) {
267 		if (supplier_set && !supplier) {
268 			msglog("-g and -q incompatible");
269 		} else {
270 			supplier = 1;
271 			supplier_set = 1;
272 		}
273 	}
274 
275 
276 	signal(SIGALRM, sigalrm);
277 	if (!background)
278 		signal(SIGHUP, sigterm);    /* SIGHUP fatal during debugging */
279 	signal(SIGTERM, sigterm);
280 	signal(SIGINT, sigterm);
281 	signal(SIGUSR1, sigtrace_on);
282 	signal(SIGUSR2, sigtrace_off);
283 
284 	/* get into the background */
285 #ifdef sgi
286 	if (0 > _daemonize(background ? 0 : (_DF_NOCHDIR|_DF_NOFORK),
287 			   STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO))
288 		BADERR(0, "_daemonize()");
289 #else
290 	if (background && daemon(0, 1) < 0)
291 		BADERR(0,"daemon()");
292 #endif
293 
294 	mypid = getpid();
295 	srandom((int)(clk.tv_sec ^ clk.tv_usec ^ mypid));
296 
297 	/* prepare socket connected to the kernel.
298 	 */
299 	rt_sock = socket(AF_ROUTE, SOCK_RAW, 0);
300 	if (rt_sock < 0)
301 		BADERR(1,"rt_sock = socket()");
302 	if (fcntl(rt_sock, F_SETFL, O_NONBLOCK) == -1)
303 		logbad(1, "fcntl(rt_sock) O_NONBLOCK: %s", strerror(errno));
304 	off = 0;
305 	if (setsockopt(rt_sock, SOL_SOCKET,SO_USELOOPBACK,
306 		       &off,sizeof(off)) < 0)
307 		LOGERR("setsockopt(SO_USELOOPBACK,0)");
308 
309 	fix_select();
310 
311 
312 	if (tracename != 0) {
313 		strncpy(inittracename, tracename, sizeof(inittracename)-1);
314 		set_tracefile(inittracename, "%s", -1);
315 	} else {
316 		tracelevel_msg("%s", -1);   /* turn on tracing to stdio */
317 	}
318 
319 	bufinit();
320 
321 	/* initialize radix tree */
322 	rtinit();
323 
324 	/* Pick a random part of the second for our output to minimize
325 	 * collisions.
326 	 *
327 	 * Start broadcasting after hearing from other routers, and
328 	 * at a random time so a bunch of systems do not get synchronized
329 	 * after a power failure.
330 	 */
331 	intvl_random(&next_bcast, EPOCH+MIN_WAITTIME, EPOCH+SUPPLY_INTERVAL);
332 	age_timer.tv_usec = next_bcast.tv_usec;
333 	age_timer.tv_sec = EPOCH+MIN_WAITTIME;
334 	rdisc_timer = next_bcast;
335 	ifinit_timer.tv_usec = next_bcast.tv_usec;
336 
337 	/* Collect an initial view of the world by checking the interface
338 	 * configuration and the kludge file.
339 	 */
340 	gwkludge();
341 	ifinit();
342 
343 	/* Ask for routes */
344 	rip_query();
345 	rdisc_sol();
346 
347 	/* Now turn off stdio if not tracing */
348 	if (new_tracelevel == 0)
349 		trace_close(background);
350 
351 	/* Loop forever, listening and broadcasting.
352 	 */
353 	for (;;) {
354 		prev_clk = clk;
355 		gettimeofday(&clk, 0);
356 		if (prev_clk.tv_sec == clk.tv_sec
357 		    && prev_clk.tv_usec == clk.tv_usec+usec_fudge) {
358 			/* Much of `routed` depends on time always advancing.
359 			 * On systems that do not guarantee that gettimeofday()
360 			 * produces unique timestamps even if called within
361 			 * a single tick, use trickery like that in classic
362 			 * BSD kernels.
363 			 */
364 			clk.tv_usec += ++usec_fudge;
365 
366 		} else {
367 			usec_fudge = 0;
368 
369 			timevalsub(&t2, &clk, &prev_clk);
370 			if (t2.tv_sec < 0
371 			    || t2.tv_sec > wtime.tv_sec + 5) {
372 				/* Deal with time changes before other
373 				 * housekeeping to keep everything straight.
374 				 */
375 				dt = t2.tv_sec;
376 				if (dt > 0)
377 					dt -= wtime.tv_sec;
378 				trace_act("time changed by %d sec", (int)dt);
379 				epoch.tv_sec += dt;
380 			}
381 		}
382 		timevalsub(&now, &clk, &epoch);
383 		now_stale = now.tv_sec - STALE_TIME;
384 		now_expire = now.tv_sec - EXPIRE_TIME;
385 		now_garbage = now.tv_sec - GARBAGE_TIME;
386 
387 		/* deal with signals that should affect tracing */
388 		set_tracelevel();
389 
390 		if (stopint != 0) {
391 			rip_bcast(0);
392 			rdisc_adv();
393 			trace_off("exiting with signal %d", stopint);
394 			exit(stopint | 128);
395 		}
396 
397 		/* look for new or dead interfaces */
398 		timevalsub(&wtime, &ifinit_timer, &now);
399 		if (wtime.tv_sec <= 0) {
400 			wtime.tv_sec = 0;
401 			ifinit();
402 			rip_query();
403 			continue;
404 		}
405 
406 		/* Check the kernel table occassionally for mysteriously
407 		 * evaporated routes
408 		 */
409 		timevalsub(&t2, &flush_kern_timer, &now);
410 		if (t2.tv_sec <= 0) {
411 			flush_kern();
412 			flush_kern_timer.tv_sec = (now.tv_sec
413 						   + CHECK_QUIET_INTERVAL);
414 			continue;
415 		}
416 		if (timercmp(&t2, &wtime, <))
417 			wtime = t2;
418 
419 		/* If it is time, then broadcast our routes.
420 		 */
421 		if (supplier || advertise_mhome) {
422 			timevalsub(&t2, &next_bcast, &now);
423 			if (t2.tv_sec <= 0) {
424 				/* Synchronize the aging and broadcast
425 				 * timers to minimize awakenings
426 				 */
427 				age(0);
428 
429 				rip_bcast(0);
430 
431 				/* It is desirable to send routing updates
432 				 * regularly.  So schedule the next update
433 				 * 30 seconds after the previous one was
434 				 * scheduled, instead of 30 seconds after
435 				 * the previous update was finished.
436 				 * Even if we just started after discovering
437 				 * a 2nd interface or were otherwise delayed,
438 				 * pick a 30-second aniversary of the
439 				 * original broadcast time.
440 				 */
441 				n = 1 + (0-t2.tv_sec)/SUPPLY_INTERVAL;
442 				next_bcast.tv_sec += n*SUPPLY_INTERVAL;
443 
444 				continue;
445 			}
446 
447 			if (timercmp(&t2, &wtime, <))
448 				wtime = t2;
449 		}
450 
451 		/* If we need a flash update, either do it now or
452 		 * set the delay to end when it is time.
453 		 *
454 		 * If we are within MIN_WAITTIME seconds of a full update,
455 		 * do not bother.
456 		 */
457 		if (need_flash
458 		    && supplier
459 		    && no_flash.tv_sec+MIN_WAITTIME < next_bcast.tv_sec) {
460 			/* accurate to the millisecond */
461 			if (!timercmp(&no_flash, &now, >))
462 				rip_bcast(1);
463 			timevalsub(&t2, &no_flash, &now);
464 			if (timercmp(&t2, &wtime, <))
465 				wtime = t2;
466 		}
467 
468 		/* trigger the main aging timer.
469 		 */
470 		timevalsub(&t2, &age_timer, &now);
471 		if (t2.tv_sec <= 0) {
472 			age(0);
473 			continue;
474 		}
475 		if (timercmp(&t2, &wtime, <))
476 			wtime = t2;
477 
478 		/* update the kernel routing table
479 		 */
480 		timevalsub(&t2, &need_kern, &now);
481 		if (t2.tv_sec <= 0) {
482 			age(0);
483 			continue;
484 		}
485 		if (timercmp(&t2, &wtime, <))
486 			wtime = t2;
487 
488 		/* take care of router discovery,
489 		 * but do it in the correct the millisecond
490 		 */
491 		if (!timercmp(&rdisc_timer, &now, >)) {
492 			rdisc_age(0);
493 			continue;
494 		}
495 		timevalsub(&t2, &rdisc_timer, &now);
496 		if (timercmp(&t2, &wtime, <))
497 			wtime = t2;
498 
499 
500 		/* wait for input or a timer to expire.
501 		 */
502 		trace_flush();
503 		ibits = fdbits;
504 		n = select(sock_max, &ibits, 0, 0, &wtime);
505 		if (n <= 0) {
506 			if (n < 0 && errno != EINTR && errno != EAGAIN)
507 				BADERR(1,"select");
508 			continue;
509 		}
510 
511 		if (FD_ISSET(rt_sock, &ibits)) {
512 			read_rt();
513 			n--;
514 		}
515 		if (rdisc_sock >= 0 && FD_ISSET(rdisc_sock, &ibits)) {
516 			read_d();
517 			n--;
518 		}
519 		if (rip_sock >= 0 && FD_ISSET(rip_sock, &ibits)) {
520 			read_rip(rip_sock, 0);
521 			n--;
522 		}
523 
524 		for (ifp = ifnet; n > 0 && 0 != ifp; ifp = ifp->int_next) {
525 			if (ifp->int_rip_sock >= 0
526 			    && FD_ISSET(ifp->int_rip_sock, &ibits)) {
527 				read_rip(ifp->int_rip_sock, ifp);
528 				n--;
529 			}
530 		}
531 	}
532 }
533 
534 
535 /* ARGSUSED */
536 void
537 sigalrm(int s UNUSED)
538 {
539 	/* Historically, SIGALRM would cause the daemon to check for
540 	 * new and broken interfaces.
541 	 */
542 	ifinit_timer.tv_sec = now.tv_sec;
543 	trace_act("SIGALRM");
544 }
545 
546 
547 /* watch for fatal signals */
548 void
549 sigterm(int sig)
550 {
551 	stopint = sig;
552 	signal(sig, SIG_DFL);	/* catch it only once */
553 }
554 
555 
556 void
557 fix_select(void)
558 {
559 	struct interface *ifp;
560 
561 
562 	FD_ZERO(&fdbits);
563 	sock_max = 0;
564 
565 	FD_SET(rt_sock, &fdbits);
566 	if (sock_max <= rt_sock)
567 		sock_max = rt_sock+1;
568 	if (rip_sock >= 0) {
569 		FD_SET(rip_sock, &fdbits);
570 		if (sock_max <= rip_sock)
571 			sock_max = rip_sock+1;
572 	}
573 	for (ifp = ifnet; NULL != ifp; ifp = ifp->int_next) {
574 		if (ifp->int_rip_sock >= 0) {
575 			FD_SET(ifp->int_rip_sock, &fdbits);
576 			if (sock_max <= ifp->int_rip_sock)
577 				sock_max = ifp->int_rip_sock+1;
578 		}
579 	}
580 	if (rdisc_sock >= 0) {
581 		FD_SET(rdisc_sock, &fdbits);
582 		if (sock_max <= rdisc_sock)
583 			sock_max = rdisc_sock+1;
584 	}
585 }
586 
587 
588 void
589 fix_sock(int sock,
590 	 const char *name)
591 {
592 	int on;
593 #define MIN_SOCKBUF (4*1024)
594 	static int rbuf;
595 
596 	if (fcntl(sock, F_SETFL, O_NONBLOCK) == -1)
597 		logbad(1, "fcntl(%s) O_NONBLOCK: %s",
598 		       name, strerror(errno));
599 	on = 1;
600 	if (setsockopt(sock, SOL_SOCKET,SO_BROADCAST, &on,sizeof(on)) < 0)
601 		msglog("setsockopt(%s,SO_BROADCAST): %s",
602 		       name, strerror(errno));
603 #ifdef USE_PASSIFNAME
604 	on = 1;
605 	if (setsockopt(sock, SOL_SOCKET, SO_PASSIFNAME, &on,sizeof(on)) < 0)
606 		msglog("setsockopt(%s,SO_PASSIFNAME): %s",
607 		       name, strerror(errno));
608 #endif
609 
610 	if (rbuf >= MIN_SOCKBUF) {
611 		if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
612 			       &rbuf, sizeof(rbuf)) < 0)
613 			msglog("setsockopt(%s,SO_RCVBUF=%d): %s",
614 			       name, rbuf, strerror(errno));
615 	} else {
616 		for (rbuf = 60*1024; ; rbuf -= 4096) {
617 			if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
618 				       &rbuf, sizeof(rbuf)) == 0) {
619 				trace_act("RCVBUF=%d", rbuf);
620 				break;
621 			}
622 			if (rbuf < MIN_SOCKBUF) {
623 				msglog("setsockopt(%s,SO_RCVBUF = %d): %s",
624 				       name, rbuf, strerror(errno));
625 				break;
626 			}
627 		}
628 	}
629 }
630 
631 
632 /* get a rip socket
633  */
634 static int				/* <0 or file descriptor */
635 get_rip_sock(naddr addr,
636 	     int serious)		/* 1=failure to bind is serious */
637 {
638 	struct sockaddr_in in;
639 	unsigned char ttl;
640 	int s;
641 
642 
643 	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
644 		BADERR(1,"rip_sock = socket()");
645 
646 	memset(&in, 0, sizeof(in));
647 #ifdef _HAVE_SIN_LEN
648 	in.sin_len = sizeof(in);
649 #endif
650 	in.sin_family = AF_INET;
651 	in.sin_port = htons(RIP_PORT);
652 	in.sin_addr.s_addr = addr;
653 	if (bind(s, (struct sockaddr *)&in, sizeof(in)) < 0) {
654 		if (serious)
655 			BADERR(errno != EADDRINUSE, "bind(rip_sock)");
656 		return -1;
657 	}
658 	fix_sock(s,"rip_sock");
659 
660 	ttl = 1;
661 	if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL,
662 		       &ttl, sizeof(ttl)) < 0)
663 		DBGERR(1,"rip_sock setsockopt(IP_MULTICAST_TTL)");
664 
665 	return s;
666 }
667 
668 
669 /* turn off main RIP socket */
670 void
671 rip_off(void)
672 {
673 	struct interface *ifp;
674 	naddr addr;
675 
676 
677 	if (rip_sock >= 0 && !mhome) {
678 		trace_act("turn off RIP");
679 
680 		close(rip_sock);
681 		rip_sock = -1;
682 
683 		/* get non-broadcast sockets to listen to queries.
684 		 */
685 		for (ifp = ifnet; ifp != NULL; ifp = ifp->int_next) {
686 			if (ifp->int_state & IS_REMOTE)
687 				continue;
688 			if (ifp->int_rip_sock < 0) {
689 				addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
690 					? ifp->int_dstaddr
691 					: ifp->int_addr);
692 				ifp->int_rip_sock = get_rip_sock(addr, 0);
693 			}
694 		}
695 
696 		fix_select();
697 
698 		age(0);
699 	}
700 }
701 
702 
703 /* turn on RIP multicast input via an interface
704  */
705 static void
706 rip_mcast_on(struct interface *ifp)
707 {
708 	struct ip_mreq m;
709 
710 	if (!IS_RIP_IN_OFF(ifp->int_state)
711 	    && (ifp->int_if_flags & IFF_MULTICAST)
712 #ifdef MCAST_PPP_BUG
713 	    && !(ifp->int_if_flags & IFF_POINTOPOINT)
714 #endif
715 	    && !(ifp->int_state & IS_ALIAS)) {
716 		m.imr_multiaddr.s_addr = htonl(INADDR_RIP_GROUP);
717 		m.imr_interface.s_addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
718 					  ? ifp->int_dstaddr
719 					  : ifp->int_addr);
720 		if (setsockopt(rip_sock,IPPROTO_IP, IP_ADD_MEMBERSHIP,
721 			       &m, sizeof(m)) < 0)
722 			LOGERR("setsockopt(IP_ADD_MEMBERSHIP RIP)");
723 	}
724 }
725 
726 
727 /* Prepare socket used for RIP.
728  */
729 void
730 rip_on(struct interface *ifp)
731 {
732 	/* If the main RIP socket is already alive, only start receiving
733 	 * multicasts for this interface.
734 	 */
735 	if (rip_sock >= 0) {
736 		if (ifp != NULL)
737 			rip_mcast_on(ifp);
738 		return;
739 	}
740 
741 	/* If the main RIP socket is off and it makes sense to turn it on,
742 	 * then turn it on for all of the interfaces.
743 	 * It makes sense if either router discovery is off, or if
744 	 * router discover is on and at most one interface is doing RIP.
745 	 */
746 	if (rip_interfaces > 0 && (!rdisc_ok || rip_interfaces > 1)) {
747 		trace_act("turn on RIP");
748 
749 		/* Close all of the query sockets so that we can open
750 		 * the main socket.  SO_REUSEPORT is not a solution,
751 		 * since that would let two daemons bind to the broadcast
752 		 * socket.
753 		 */
754 		for (ifp = ifnet; ifp != NULL; ifp = ifp->int_next) {
755 			if (ifp->int_rip_sock >= 0) {
756 				close(ifp->int_rip_sock);
757 				ifp->int_rip_sock = -1;
758 			}
759 		}
760 
761 		rip_sock = get_rip_sock(INADDR_ANY, 1);
762 		rip_sock_mcast = NULL;
763 
764 		/* Do not advertise anything until we have heard something
765 		 */
766 		if (next_bcast.tv_sec < now.tv_sec+MIN_WAITTIME)
767 			next_bcast.tv_sec = now.tv_sec+MIN_WAITTIME;
768 
769 		for (ifp = ifnet; ifp != NULL; ifp = ifp->int_next) {
770 			ifp->int_query_time = NEVER;
771 			rip_mcast_on(ifp);
772 		}
773 		ifinit_timer.tv_sec = now.tv_sec;
774 
775 	} else if (ifp != NULL
776 		   && !(ifp->int_state & IS_REMOTE)
777 		   && ifp->int_rip_sock < 0) {
778 		/* RIP is off, so ensure there are sockets on which
779 		 * to listen for queries.
780 		 */
781 		ifp->int_rip_sock = get_rip_sock(ifp->int_addr, 0);
782 	}
783 
784 	fix_select();
785 }
786 
787 
788 /* die if malloc(3) fails
789  */
790 void *
791 rtmalloc(size_t size,
792 	 const char *msg)
793 {
794 	void *p = malloc(size);
795 	if (p == NULL)
796 		logbad(1,"malloc(%lu) failed in %s", (u_long)size, msg);
797 	return p;
798 }
799 
800 
801 /* get a random instant in an interval
802  */
803 void
804 intvl_random(struct timeval *tp,	/* put value here */
805 	     u_long lo,			/* value is after this second */
806 	     u_long hi)			/* and before this */
807 {
808 	tp->tv_sec = (time_t)(hi == lo
809 			      ? lo
810 			      : (lo + random() % ((hi - lo))));
811 	tp->tv_usec = random() % 1000000;
812 }
813 
814 
815 void
816 timevaladd(struct timeval *t1,
817 	   struct timeval *t2)
818 {
819 
820 	t1->tv_sec += t2->tv_sec;
821 	if ((t1->tv_usec += t2->tv_usec) >= 1000000) {
822 		t1->tv_sec++;
823 		t1->tv_usec -= 1000000;
824 	}
825 }
826 
827 
828 /* t1 = t2 - t3
829  */
830 static void
831 timevalsub(struct timeval *t1,
832 	   struct timeval *t2,
833 	   struct timeval *t3)
834 {
835 	t1->tv_sec = t2->tv_sec - t3->tv_sec;
836 	if ((t1->tv_usec = t2->tv_usec - t3->tv_usec) < 0) {
837 		t1->tv_sec--;
838 		t1->tv_usec += 1000000;
839 	}
840 }
841 
842 
843 /* put a message into the system log
844  */
845 void
846 msglog(const char *p, ...)
847 {
848 	va_list args;
849 
850 	trace_flush();
851 
852 	va_start(args, p);
853 	vsyslog(LOG_ERR, p, args);
854 
855 	if (ftrace != 0) {
856 		if (ftrace == stdout)
857 			fputs("routed: ", ftrace);
858 		vfprintf(ftrace, p, args);
859 		fputc('\n', ftrace);
860 	}
861 }
862 
863 
864 /* Put a message about a bad system into the system log if
865  * we have not complained about it recently.
866  *
867  * It is desirable to complain about all bad systems, but not too often.
868  * In the worst case, it is not practical to keep track of all bad systems.
869  * For example, there can be many systems with the wrong password.
870  */
871 void
872 msglim(struct msg_limit *lim, naddr addr, const char *p, ...)
873 {
874 	va_list args;
875 	int i;
876 	struct msg_sub *ms1, *ms;
877 	const char *p1;
878 
879 	va_start(args, p);
880 
881 	/* look for the oldest slot in the table
882 	 * or the slot for the bad router.
883 	 */
884 	ms = ms1 = lim->subs;
885 	for (i = MSG_SUBJECT_N; ; i--, ms1++) {
886 		if (i == 0) {
887 			/* Reuse a slot at most once every 10 minutes.
888 			 */
889 			if (lim->reuse > now.tv_sec) {
890 				ms = NULL;
891 			} else {
892 				ms = ms1;
893 				lim->reuse = now.tv_sec + 10*60;
894 			}
895 			break;
896 		}
897 		if (ms->addr == addr) {
898 			/* Repeat a complaint about a given system at
899 			 * most once an hour.
900 			 */
901 			if (ms->until > now.tv_sec)
902 				ms = NULL;
903 			break;
904 		}
905 		if (ms->until < ms1->until)
906 			ms = ms1;
907 	}
908 	if (ms != NULL) {
909 		ms->addr = addr;
910 		ms->until = now.tv_sec + 60*60;	/* 60 minutes */
911 
912 		trace_flush();
913 		for (p1 = p; *p1 == ' '; p1++)
914 			continue;
915 		vsyslog(LOG_ERR, p1, args);
916 	}
917 
918 	/* always display the message if tracing */
919 	if (ftrace != 0) {
920 		vfprintf(ftrace, p, args);
921 		fputc('\n', ftrace);
922 	}
923 }
924 
925 
926 void
927 logbad(int dump, const char *p, ...)
928 {
929 	va_list args;
930 
931 	trace_flush();
932 
933 	va_start(args, p);
934 	vsyslog(LOG_ERR, p, args);
935 
936 	fputs("routed: ", stderr);
937 	vfprintf(stderr, p, args);
938 	fputs("; giving up\n",stderr);
939 	fflush(stderr);
940 
941 	if (dump)
942 		abort();
943 	exit(1);
944 }
945