xref: /netbsd-src/sbin/routed/main.c (revision dc306354b0b29af51801a7632f1e95265a68cd81)
1 /*	$NetBSD: main.c,v 1.20 1998/10/25 14:56:07 christos 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 char copyright[] =
37 "@(#) Copyright (c) 1983, 1988, 1993\n\
38 	The Regents of the University of California.  All rights reserved.\n";
39 #if !defined(lint) && !defined(sgi) && !defined(__NetBSD__)
40 static char sccsid[] = "@(#)main.c	8.1 (Berkeley) 6/5/93";
41 #elif defined(__NetBSD__)
42 #include <sys/cdefs.h>
43 __RCSID("$NetBSD: main.c,v 1.20 1998/10/25 14:56:07 christos Exp $");
44 #endif
45 
46 #include "defs.h"
47 #include "pathnames.h"
48 #ifdef sgi
49 #include "math.h"
50 #endif
51 #include <signal.h>
52 #include <fcntl.h>
53 #include <sys/file.h>
54 #if defined(sgi) && !defined(PRE_KUDZU)
55 #include <cap_net.h>
56 #else
57 #define cap_socket socket
58 #define cap_bind bind
59 #endif
60 
61 pid_t	mypid;
62 
63 naddr	myaddr;				/* system address */
64 char	myname[MAXHOSTNAMELEN+1];
65 
66 int	verbose;
67 
68 int	supplier;			/* supply or broadcast updates */
69 int	supplier_set;
70 int	ipforwarding = 1;		/* kernel forwarding on */
71 
72 int	default_gateway;		/* 1=advertise default */
73 int	background = 1;
74 int	ridhosts;			/* 1=reduce host routes */
75 int	mhome;				/* 1=want multi-homed host route */
76 int	advertise_mhome;		/* 1=must continue advertising it */
77 int	auth_ok = 1;			/* 1=ignore auth if we do not care */
78 
79 struct timeval epoch;			/* when started */
80 struct timeval clk, prev_clk;
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 = {EPOCH+SUPPLY_INTERVAL};  /* inhibit flash update */
88 
89 struct timeval flush_kern_timer;
90 
91 fd_set	fdbits;
92 int	sock_max;
93 int	rip_sock = -1;			/* RIP socket */
94 struct interface *rip_sock_mcast;	/* current multicast interface */
95 int	rt_sock;			/* routing socket */
96 int	rt_sock_seqno;
97 
98 
99 static  int get_rip_sock(naddr, int);
100 static void timevalsub(struct timeval *, struct timeval *, struct timeval *);
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 	struct timeval wtime, t2;
110 	time_t dt;
111 	fd_set ibits;
112 	naddr p_net, p_mask;
113 	struct interface *ifp;
114 	struct parm parm;
115 	char *tracename = 0;
116 
117 
118 	/* Some shells are badly broken and send SIGHUP to backgrounded
119 	 * processes.
120 	 */
121 	signal(SIGHUP, SIG_IGN);
122 
123 	openlog("routed", LOG_PID | LOG_ODELAY, LOG_DAEMON);
124 	ftrace = stdout;
125 
126 	gettimeofday(&clk, 0);
127 	prev_clk = clk;
128 	epoch = clk;
129 	epoch.tv_sec -= EPOCH;
130 	now.tv_sec = EPOCH;
131 	now_stale = EPOCH - STALE_TIME;
132 	now_expire = EPOCH - EXPIRE_TIME;
133 	now_garbage = EPOCH - GARBAGE_TIME;
134 	wtime.tv_sec = 0;
135 
136 	(void)gethostname(myname, sizeof(myname));
137 	myname[sizeof(myname) - 1] = '\0';
138 	(void)gethost(myname, &myaddr);
139 
140 	while ((n = getopt(argc, argv, "sqdghmpAtvT:F:P:")) != -1) {
141 		switch (n) {
142 		case 's':
143 			supplier = 1;
144 			supplier_set = 1;
145 			break;
146 
147 		case 'q':
148 			supplier = 0;
149 			supplier_set = 1;
150 			break;
151 
152 		case 'd':
153 			background = 0;
154 			break;
155 
156 		case 'g':
157 			memset(&parm, 0, sizeof(parm));
158 			parm.parm_d_metric = 1;
159 			p = check_parms(&parm);
160 			if (p != 0)
161 				msglog("bad -g: %s", p);
162 			else
163 				default_gateway = 1;
164 			break;
165 
166 		case 'h':		/* suppress extra host routes */
167 			ridhosts = 1;
168 			break;
169 
170 		case 'm':		/* advertise host route */
171 			mhome = 1;	/* on multi-homed hosts */
172 			break;
173 
174 		case 'A':
175 			/* Ignore authentication if we do not care.
176 			 * Crazy as it is, that is what RFC 1723 requires.
177 			 */
178 			auth_ok = 0;
179 			break;
180 
181 		case 't':
182 			new_tracelevel++;
183 			break;
184 
185 		case 'T':
186 			tracename = optarg;
187 			break;
188 
189 		case 'F':		/* minimal routes for SLIP */
190 			n = FAKE_METRIC;
191 			p = strchr(optarg,',');
192 			if (p && *p != '\0') {
193 				n = (int)strtoul(p+1, &q, 0);
194 				if (*q == '\0'
195 				    && n <= HOPCNT_INFINITY-1
196 				    && n >= 1)
197 					*p = '\0';
198 			}
199 			if (!getnet(optarg, &p_net, &p_mask)) {
200 				msglog("bad network; \"-F %s\"",
201 				       optarg);
202 				break;
203 			}
204 			memset(&parm, 0, sizeof(parm));
205 			parm.parm_net = p_net;
206 			parm.parm_mask = p_mask;
207 			parm.parm_d_metric = n;
208 			p = check_parms(&parm);
209 			if (p != 0)
210 				msglog("bad -F: %s", p);
211 			break;
212 
213 		case 'P':
214 			/* handle arbitrary parameters.
215 			 */
216 			q = strdup(optarg);
217 			p = parse_parms(q, 0);
218 			if (p != 0)
219 				msglog("%s in \"-P %s\"", p, optarg);
220 			free(q);
221 			break;
222 
223 		case 'v':
224 			/* display version */
225 			verbose++;
226 			msglog("version 2.15");
227 			break;
228 
229 		default:
230 			goto usage;
231 		}
232 	}
233 	argc -= optind;
234 	argv += optind;
235 
236 	if (tracename == 0 && argc >= 1) {
237 		tracename = *argv++;
238 		argc--;
239 	}
240 	if (tracename != 0 && tracename[0] == '\0')
241 		goto usage;
242 	if (argc != 0) {
243 usage:
244 		logbad(0, "usage: routed [-sqdghmpAtv] [-T tracefile]"
245 		       " [-F net[,metric]] [-P parms]");
246 	}
247 	if (geteuid() != 0) {
248 		if (verbose)
249 			exit(0);
250 		logbad(0, "requires UID 0");
251 	}
252 
253 	mib[0] = CTL_NET;
254 	mib[1] = PF_INET;
255 	mib[2] = IPPROTO_IP;
256 	mib[3] = IPCTL_FORWARDING;
257 	len = sizeof(ipforwarding);
258 	if (sysctl(mib, 4, &ipforwarding, &len, 0, 0) < 0)
259 		LOGERR("sysctl(IPCTL_FORWARDING)");
260 
261 	if (!ipforwarding) {
262 		if (supplier)
263 			msglog("-s incompatible with ipforwarding=0");
264 		if (default_gateway) {
265 			msglog("-g incompatible with ipforwarding=0");
266 			default_gateway = 0;
267 		}
268 		supplier = 0;
269 		supplier_set = 1;
270 	}
271 	if (default_gateway) {
272 		if (supplier_set && !supplier) {
273 			msglog("-g and -q incompatible");
274 		} else {
275 			supplier = 1;
276 			supplier_set = 1;
277 		}
278 	}
279 
280 
281 	signal(SIGALRM, sigalrm);
282 	if (!background)
283 		signal(SIGHUP, sigterm);    /* SIGHUP fatal during debugging */
284 	signal(SIGTERM, sigterm);
285 	signal(SIGINT, sigterm);
286 	signal(SIGUSR1, sigtrace_on);
287 	signal(SIGUSR2, sigtrace_off);
288 
289 	/* get into the background */
290 #ifdef sgi
291 	if (0 > _daemonize(background ? 0 : (_DF_NOCHDIR|_DF_NOFORK),
292 			   STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO))
293 		BADERR(0, "_daemonize()");
294 #else
295 	if (background && daemon(0, 1) < 0)
296 		BADERR(0,"daemon()");
297 #endif
298 
299 	mypid = getpid();
300 	srandom((int)(clk.tv_sec ^ clk.tv_usec ^ mypid));
301 
302 	/* prepare socket connected to the kernel.
303 	 */
304 	rt_sock = cap_socket(AF_ROUTE, SOCK_RAW, 0);
305 	if (rt_sock < 0)
306 		BADERR(1,"rt_sock = socket()");
307 	if (fcntl(rt_sock, F_SETFL, O_NONBLOCK) == -1)
308 		logbad(1, "fcntl(rt_sock) O_NONBLOCK: %s", strerror(errno));
309 	off = 0;
310 	if (setsockopt(rt_sock, SOL_SOCKET,SO_USELOOPBACK,
311 		       &off,sizeof(off)) < 0)
312 		LOGERR("setsockopt(SO_USELOOPBACK,0)");
313 
314 	fix_select();
315 
316 
317 	if (tracename != 0) {
318 		strncpy(inittracename, tracename, sizeof(inittracename)-1);
319 		set_tracefile(inittracename, "%s", -1);
320 	} else {
321 		tracelevel_msg("%s", -1);   /* turn on tracing to stdio */
322 	}
323 
324 	bufinit();
325 
326 	/* initialize radix tree */
327 	rtinit();
328 
329 	/* Pick a random part of the second for our output to minimize
330 	 * collisions.
331 	 *
332 	 * Start broadcasting after hearing from other routers, and
333 	 * at a random time so a bunch of systems do not get synchronized
334 	 * after a power failure.
335 	 */
336 	intvl_random(&next_bcast, EPOCH+MIN_WAITTIME, EPOCH+SUPPLY_INTERVAL);
337 	age_timer.tv_usec = next_bcast.tv_usec;
338 	age_timer.tv_sec = EPOCH+MIN_WAITTIME;
339 	rdisc_timer = next_bcast;
340 	ifinit_timer.tv_usec = next_bcast.tv_usec;
341 
342 	/* Collect an initial view of the world by checking the interface
343 	 * configuration and the kludge file.
344 	 */
345 	gwkludge();
346 	ifinit();
347 
348 	/* Ask for routes */
349 	rip_query();
350 	rdisc_sol();
351 
352 	/* Now turn off stdio if not tracing */
353 	if (new_tracelevel == 0)
354 		trace_close(background);
355 
356 	/* Loop forever, listening and broadcasting.
357 	 */
358 	for (;;) {
359 		prev_clk = clk;
360 		gettimeofday(&clk, 0);
361 		timevalsub(&t2, &clk, &prev_clk);
362 		if (t2.tv_sec < 0
363 		    || t2.tv_sec > wtime.tv_sec + 5) {
364 			/* Deal with time changes before other housekeeping to
365 			 * keep everything straight.
366 			 */
367 			dt = t2.tv_sec;
368 			if (dt > 0)
369 				dt -= wtime.tv_sec;
370 			trace_act("time changed by %d sec", dt);
371 			epoch.tv_sec += dt;
372 		}
373 		timevalsub(&now, &clk, &epoch);
374 		now_stale = now.tv_sec - STALE_TIME;
375 		now_expire = now.tv_sec - EXPIRE_TIME;
376 		now_garbage = now.tv_sec - GARBAGE_TIME;
377 
378 		/* deal with signals that should affect tracing */
379 		set_tracelevel();
380 
381 		if (stopint != 0) {
382 			rip_bcast(0);
383 			rdisc_adv();
384 			trace_off("exiting with signal %d", stopint);
385 			exit(stopint | 128);
386 		}
387 
388 		/* look for new or dead interfaces */
389 		timevalsub(&wtime, &ifinit_timer, &now);
390 		if (wtime.tv_sec <= 0) {
391 			wtime.tv_sec = 0;
392 			ifinit();
393 			rip_query();
394 			continue;
395 		}
396 
397 		/* Check the kernel table occassionally for mysteriously
398 		 * evaporated routes
399 		 */
400 		timevalsub(&t2, &flush_kern_timer, &now);
401 		if (t2.tv_sec <= 0) {
402 			flush_kern();
403 			flush_kern_timer.tv_sec = (now.tv_sec
404 						   + CHECK_QUIET_INTERVAL);
405 			continue;
406 		}
407 		if (timercmp(&t2, &wtime, <))
408 			wtime = t2;
409 
410 		/* If it is time, then broadcast our routes.
411 		 */
412 		if (supplier || advertise_mhome) {
413 			timevalsub(&t2, &next_bcast, &now);
414 			if (t2.tv_sec <= 0) {
415 				/* Synchronize the aging and broadcast
416 				 * timers to minimize awakenings
417 				 */
418 				age(0);
419 
420 				rip_bcast(0);
421 
422 				/* It is desirable to send routing updates
423 				 * regularly.  So schedule the next update
424 				 * 30 seconds after the previous one was
425 				 * scheduled, instead of 30 seconds after
426 				 * the previous update was finished.
427 				 * Even if we just started after discovering
428 				 * a 2nd interface or were otherwise delayed,
429 				 * pick a 30-second aniversary of the
430 				 * original broadcast time.
431 				 */
432 				n = 1 + (0-t2.tv_sec)/SUPPLY_INTERVAL;
433 				next_bcast.tv_sec += n*SUPPLY_INTERVAL;
434 
435 				continue;
436 			}
437 
438 			if (timercmp(&t2, &wtime, <))
439 				wtime = t2;
440 		}
441 
442 		/* If we need a flash update, either do it now or
443 		 * set the delay to end when it is time.
444 		 *
445 		 * If we are within MIN_WAITTIME seconds of a full update,
446 		 * do not bother.
447 		 */
448 		if (need_flash
449 		    && supplier
450 		    && no_flash.tv_sec+MIN_WAITTIME < next_bcast.tv_sec) {
451 			/* accurate to the millisecond */
452 			if (!timercmp(&no_flash, &now, >))
453 				rip_bcast(1);
454 			timevalsub(&t2, &no_flash, &now);
455 			if (timercmp(&t2, &wtime, <))
456 				wtime = t2;
457 		}
458 
459 		/* trigger the main aging timer.
460 		 */
461 		timevalsub(&t2, &age_timer, &now);
462 		if (t2.tv_sec <= 0) {
463 			age(0);
464 			continue;
465 		}
466 		if (timercmp(&t2, &wtime, <))
467 			wtime = t2;
468 
469 		/* update the kernel routing table
470 		 */
471 		timevalsub(&t2, &need_kern, &now);
472 		if (t2.tv_sec <= 0) {
473 			age(0);
474 			continue;
475 		}
476 		if (timercmp(&t2, &wtime, <))
477 			wtime = t2;
478 
479 		/* take care of router discovery,
480 		 * but do it in the correct the millisecond
481 		 */
482 		if (!timercmp(&rdisc_timer, &now, >)) {
483 			rdisc_age(0);
484 			continue;
485 		}
486 		timevalsub(&t2, &rdisc_timer, &now);
487 		if (timercmp(&t2, &wtime, <))
488 			wtime = t2;
489 
490 
491 		/* wait for input or a timer to expire.
492 		 */
493 		trace_flush();
494 		ibits = fdbits;
495 		n = select(sock_max, &ibits, 0, 0, &wtime);
496 		if (n <= 0) {
497 			if (n < 0 && errno != EINTR && errno != EAGAIN)
498 				BADERR(1,"select");
499 			continue;
500 		}
501 
502 		if (FD_ISSET(rt_sock, &ibits)) {
503 			read_rt();
504 			n--;
505 		}
506 		if (rdisc_sock >= 0 && FD_ISSET(rdisc_sock, &ibits)) {
507 			read_d();
508 			n--;
509 		}
510 		if (rip_sock >= 0 && FD_ISSET(rip_sock, &ibits)) {
511 			read_rip(rip_sock, 0);
512 			n--;
513 		}
514 
515 		for (ifp = ifnet; n > 0 && 0 != ifp; ifp = ifp->int_next) {
516 			if (ifp->int_rip_sock >= 0
517 			    && FD_ISSET(ifp->int_rip_sock, &ibits)) {
518 				read_rip(ifp->int_rip_sock, ifp);
519 				n--;
520 			}
521 		}
522 	}
523 }
524 
525 
526 /* ARGSUSED */
527 void
528 sigalrm(int s)
529 {
530 	/* Historically, SIGALRM would cause the daemon to check for
531 	 * new and broken interfaces.
532 	 */
533 	ifinit_timer.tv_sec = now.tv_sec;
534 	trace_act("SIGALRM");
535 }
536 
537 
538 /* watch for fatal signals */
539 void
540 sigterm(int sig)
541 {
542 	stopint = sig;
543 	(void)signal(sig, SIG_DFL);	/* catch it only once */
544 }
545 
546 
547 void
548 fix_select(void)
549 {
550 	struct interface *ifp;
551 
552 
553 	FD_ZERO(&fdbits);
554 	sock_max = 0;
555 
556 	FD_SET(rt_sock, &fdbits);
557 	if (sock_max <= rt_sock)
558 		sock_max = rt_sock+1;
559 	if (rip_sock >= 0) {
560 		FD_SET(rip_sock, &fdbits);
561 		if (sock_max <= rip_sock)
562 			sock_max = rip_sock+1;
563 	}
564 	for (ifp = ifnet; 0 != ifp; ifp = ifp->int_next) {
565 		if (ifp->int_rip_sock >= 0) {
566 			FD_SET(ifp->int_rip_sock, &fdbits);
567 			if (sock_max <= ifp->int_rip_sock)
568 				sock_max = ifp->int_rip_sock+1;
569 		}
570 	}
571 	if (rdisc_sock >= 0) {
572 		FD_SET(rdisc_sock, &fdbits);
573 		if (sock_max <= rdisc_sock)
574 			sock_max = rdisc_sock+1;
575 	}
576 }
577 
578 
579 void
580 fix_sock(int sock,
581 	 char *name)
582 {
583 	int on;
584 #define MIN_SOCKBUF (4*1024)
585 	static int rbuf;
586 
587 	if (fcntl(sock, F_SETFL, O_NONBLOCK) == -1)
588 		logbad(1, "fcntl(%s) O_NONBLOCK: %s",
589 		       name, strerror(errno));
590 	on = 1;
591 	if (setsockopt(sock, SOL_SOCKET,SO_BROADCAST, &on,sizeof(on)) < 0)
592 		msglog("setsockopt(%s,SO_BROADCAST): %s",
593 		       name, strerror(errno));
594 #ifdef USE_PASSIFNAME
595 	on = 1;
596 	if (setsockopt(sock, SOL_SOCKET, SO_PASSIFNAME, &on,sizeof(on)) < 0)
597 		msglog("setsockopt(%s,SO_PASSIFNAME): %s",
598 		       name, strerror(errno));
599 #endif
600 
601 	if (rbuf >= MIN_SOCKBUF) {
602 		if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
603 			       &rbuf, sizeof(rbuf)) < 0)
604 			msglog("setsockopt(%s,SO_RCVBUF=%d): %s",
605 			       name, rbuf, strerror(errno));
606 	} else {
607 		for (rbuf = 60*1024; ; rbuf -= 4096) {
608 			if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
609 				       &rbuf, sizeof(rbuf)) == 0) {
610 				trace_act("RCVBUF=%d", rbuf);
611 				break;
612 			}
613 			if (rbuf < MIN_SOCKBUF) {
614 				msglog("setsockopt(%s,SO_RCVBUF = %d): %s",
615 				       name, rbuf, strerror(errno));
616 				break;
617 			}
618 		}
619 	}
620 }
621 
622 
623 /* get a rip socket
624  */
625 static int				/* <0 or file descriptor */
626 get_rip_sock(naddr addr,
627 	     int serious)		/* 1=failure to bind is serious */
628 {
629 	struct sockaddr_in sin;
630 	unsigned char ttl;
631 	int s;
632 
633 
634 	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
635 		BADERR(1,"rip_sock = socket()");
636 
637 	memset(&sin, 0, sizeof(sin));
638 #ifdef _HAVE_SIN_LEN
639 	sin.sin_len = sizeof(sin);
640 #endif
641 	sin.sin_family = AF_INET;
642 	sin.sin_port = htons(RIP_PORT);
643 	sin.sin_addr.s_addr = addr;
644 	if (cap_bind(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
645 		if (serious)
646 			BADERR(errno != EADDRINUSE, "bind(rip_sock)");
647 		return -1;
648 	}
649 	fix_sock(s,"rip_sock");
650 
651 	ttl = 1;
652 	if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL,
653 		       &ttl, sizeof(ttl)) < 0)
654 		DBGERR(1,"rip_sock setsockopt(IP_MULTICAST_TTL)");
655 
656 	return s;
657 }
658 
659 
660 /* turn off main RIP socket */
661 void
662 rip_off(void)
663 {
664 	struct interface *ifp;
665 	naddr addr;
666 
667 
668 	if (rip_sock >= 0 && !mhome) {
669 		trace_act("turn off RIP");
670 
671 		(void)close(rip_sock);
672 		rip_sock = -1;
673 
674 		/* get non-broadcast sockets to listen to queries.
675 		 */
676 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
677 			if (ifp->int_state & IS_REMOTE)
678 				continue;
679 			if (ifp->int_rip_sock < 0) {
680 				addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
681 					? ifp->int_dstaddr
682 					: ifp->int_addr);
683 				ifp->int_rip_sock = get_rip_sock(addr, 0);
684 			}
685 		}
686 
687 		fix_select();
688 
689 		age(0);
690 	}
691 }
692 
693 
694 /* turn on RIP multicast input via an interface
695  */
696 static void
697 rip_mcast_on(struct interface *ifp)
698 {
699 	struct ip_mreq m;
700 
701 	if (!IS_RIP_IN_OFF(ifp->int_state)
702 	    && (ifp->int_if_flags & IFF_MULTICAST)
703 #ifdef MCAST_PPP_BUG
704 	    && !(ifp->int_if_flags & IFF_POINTOPOINT)
705 #endif
706 	    && !(ifp->int_state & IS_ALIAS)) {
707 		m.imr_multiaddr.s_addr = htonl(INADDR_RIP_GROUP);
708 		m.imr_interface.s_addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
709 					  ? ifp->int_dstaddr
710 					  : ifp->int_addr);
711 		if (setsockopt(rip_sock,IPPROTO_IP, IP_ADD_MEMBERSHIP,
712 			       &m, sizeof(m)) < 0)
713 			LOGERR("setsockopt(IP_ADD_MEMBERSHIP RIP)");
714 	}
715 }
716 
717 
718 /* Prepare socket used for RIP.
719  */
720 void
721 rip_on(struct interface *ifp)
722 {
723 	/* If the main RIP socket is already alive, only start receiving
724 	 * multicasts for this interface.
725 	 */
726 	if (rip_sock >= 0) {
727 		if (ifp != 0)
728 			rip_mcast_on(ifp);
729 		return;
730 	}
731 
732 	/* If the main RIP socket is off and it makes sense to turn it on,
733 	 * then turn it on for all of the interfaces.
734 	 * It makes sense if either router discovery is off, or if
735 	 * router discover is on and at most one interface is doing RIP.
736 	 */
737 	if (rip_interfaces > 0 && (!rdisc_ok || rip_interfaces > 1)) {
738 		trace_act("turn on RIP");
739 
740 		/* Close all of the query sockets so that we can open
741 		 * the main socket.  SO_REUSEPORT is not a solution,
742 		 * since that would let two daemons bind to the broadcast
743 		 * socket.
744 		 */
745 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
746 			if (ifp->int_rip_sock >= 0) {
747 				(void)close(ifp->int_rip_sock);
748 				ifp->int_rip_sock = -1;
749 			}
750 		}
751 
752 		rip_sock = get_rip_sock(INADDR_ANY, 1);
753 		rip_sock_mcast = 0;
754 
755 		/* Do not advertise anything until we have heard something
756 		 */
757 		if (next_bcast.tv_sec < now.tv_sec+MIN_WAITTIME)
758 			next_bcast.tv_sec = now.tv_sec+MIN_WAITTIME;
759 
760 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
761 			ifp->int_query_time = NEVER;
762 			rip_mcast_on(ifp);
763 		}
764 		ifinit_timer.tv_sec = now.tv_sec;
765 
766 	} else if (ifp != 0
767 		   && !(ifp->int_state & IS_REMOTE)
768 		   && ifp->int_rip_sock < 0) {
769 		/* RIP is off, so ensure there are sockets on which
770 		 * to listen for queries.
771 		 */
772 		ifp->int_rip_sock = get_rip_sock(ifp->int_addr, 0);
773 	}
774 
775 	fix_select();
776 }
777 
778 
779 /* die if malloc(3) fails
780  */
781 void *
782 rtmalloc(size_t size,
783 	 char *msg)
784 {
785 	void *p = malloc(size);
786 	if (p == 0)
787 		logbad(1,"malloc(%d) failed in %s", size, msg);
788 	return p;
789 }
790 
791 
792 /* get a random instant in an interval
793  */
794 void
795 intvl_random(struct timeval *tp,	/* put value here */
796 	     u_long lo,			/* value is after this second */
797 	     u_long hi)			/* and before this */
798 {
799 	tp->tv_sec = (time_t)(hi == lo
800 			      ? lo
801 			      : (lo + random() % ((hi - lo))));
802 	tp->tv_usec = random() % 1000000;
803 }
804 
805 
806 void
807 timevaladd(struct timeval *t1,
808 	   struct timeval *t2)
809 {
810 
811 	t1->tv_sec += t2->tv_sec;
812 	if ((t1->tv_usec += t2->tv_usec) >= 1000000) {
813 		t1->tv_sec++;
814 		t1->tv_usec -= 1000000;
815 	}
816 }
817 
818 
819 /* t1 = t2 - t3
820  */
821 static void
822 timevalsub(struct timeval *t1,
823 	   struct timeval *t2,
824 	   struct timeval *t3)
825 {
826 	t1->tv_sec = t2->tv_sec - t3->tv_sec;
827 	if ((t1->tv_usec = t2->tv_usec - t3->tv_usec) < 0) {
828 		t1->tv_sec--;
829 		t1->tv_usec += 1000000;
830 	}
831 }
832 
833 
834 /* put a message into the system log
835  */
836 void
837 msglog(char *p, ...)
838 {
839 	va_list args;
840 
841 	trace_flush();
842 
843 	va_start(args, p);
844 	vsyslog(LOG_ERR, p, args);
845 
846 	if (ftrace != 0) {
847 		if (ftrace == stdout)
848 			(void)fputs("routed: ", ftrace);
849 		(void)vfprintf(ftrace, p, args);
850 		(void)fputc('\n', ftrace);
851 	}
852 }
853 
854 
855 /* Put a message about a bad system into the system log if
856  * we have not complained about it recently.
857  *
858  * It is desirable to complain about all bad systems, but not too often.
859  * In the worst case, it is not practical to keep track of all bad systems.
860  * For example, there can be many systems with the wrong password.
861  */
862 void
863 msglim(struct msg_limit *lim, naddr addr, char *p, ...)
864 {
865 	va_list args;
866 	int i;
867 	struct msg_sub *ms1, *ms;
868 	char *p1;
869 
870 	va_start(args, p);
871 
872 	/* look for the oldest slot in the table
873 	 * or the slot for the bad router.
874 	 */
875 	ms = ms1 = lim->subs;
876 	for (i = MSG_SUBJECT_N; ; i--, ms1++) {
877 		if (i == 0) {
878 			/* Reuse a slot at most once every 10 minutes.
879 			 */
880 			if (lim->reuse > now.tv_sec) {
881 				ms = 0;
882 			} else {
883 				ms = ms1;
884 				lim->reuse = now.tv_sec + 10*60;
885 			}
886 			break;
887 		}
888 		if (ms->addr == addr) {
889 			/* Repeat a complaint about a given system at
890 			 * most once an hour.
891 			 */
892 			if (ms->until > now.tv_sec)
893 				ms = 0;
894 			break;
895 		}
896 		if (ms->until < ms1->until)
897 			ms = ms1;
898 	}
899 	if (ms != 0) {
900 		ms->addr = addr;
901 		ms->until = now.tv_sec + 60*60;	/* 60 minutes */
902 
903 		trace_flush();
904 		for (p1 = p; *p1 == ' '; p1++)
905 			continue;
906 		vsyslog(LOG_ERR, p1, args);
907 	}
908 
909 	/* always display the message if tracing */
910 	if (ftrace != 0) {
911 		(void)vfprintf(ftrace, p, args);
912 		(void)fputc('\n', ftrace);
913 	}
914 }
915 
916 
917 void
918 logbad(int dump, char *p, ...)
919 {
920 	va_list args;
921 
922 	trace_flush();
923 
924 	va_start(args, p);
925 	vsyslog(LOG_ERR, p, args);
926 
927 	(void)fputs("routed: ", stderr);
928 	(void)vfprintf(stderr, p, args);
929 	(void)fputs("; giving up\n",stderr);
930 	(void)fflush(stderr);
931 
932 	if (dump)
933 		abort();
934 	exit(1);
935 }
936