xref: /dragonfly/sbin/routed/main.c (revision a3127495)
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 #include <signal.h>
35 #include <fcntl.h>
36 #include <sys/file.h>
37 
38 #if !defined(__NetBSD__)
39 char copyright[] =
40 "@(#) Copyright (c) 1983, 1988, 1993\n\
41 	The Regents of the University of California.  All rights reserved.\n";
42 static char sccsid[] __attribute__((unused)) = "@(#)main.c	8.1 (Berkeley) 6/5/93";
43 #elif defined(__NetBSD__)
44 __RCSID("$NetBSD$");
45 __COPYRIGHT("@(#) Copyright (c) 1983, 1988, 1993\n\
46 	The Regents of the University of California.  All rights reserved.\n");
47 #endif
48 
49 
50 pid_t	mypid;
51 
52 naddr	myaddr;				/* system address */
53 char	myname[MAXHOSTNAMELEN+1];
54 
55 int	verbose;
56 
57 int	supplier;			/* supply or broadcast updates */
58 int	supplier_set;
59 int	ipforwarding = 1;		/* kernel forwarding on */
60 
61 int	default_gateway;		/* 1=advertise default */
62 int	background = 1;
63 int	ridhosts;			/* 1=reduce host routes */
64 int	mhome;				/* 1=want multi-homed host route */
65 int	advertise_mhome;		/* 1=must continue advertising it */
66 int	auth_ok = 1;			/* 1=ignore auth if we do not care */
67 
68 struct timeval epoch;			/* when started */
69 struct timeval clk, prev_clk;
70 static int usec_fudge;
71 struct timeval now;			/* current idea of time */
72 time_t	now_stale;
73 time_t	now_expire;
74 time_t	now_garbage;
75 
76 struct timeval next_bcast;		/* next general broadcast */
77 struct timeval no_flash = {		/* inhibit flash update */
78 	EPOCH+SUPPLY_INTERVAL, 0
79 };
80 
81 struct timeval flush_kern_timer;
82 
83 fd_set	fdbits;
84 int	sock_max;
85 int	rip_sock = -1;			/* RIP socket */
86 struct interface *rip_sock_mcast;	/* current multicast interface */
87 int	rt_sock;			/* routing socket */
88 int	rt_sock_seqno;
89 
90 
91 static  int get_rip_sock(naddr, int);
92 static void timevalsub(struct timeval *, struct timeval *, struct timeval *);
93 
94 int
95 main(int argc,
96      char *argv[])
97 {
98 	int n, mib[4], off;
99 	size_t len;
100 	char *p, *q;
101 	const char *cp;
102 	struct timeval wtime, t2;
103 	time_t dt;
104 	fd_set ibits;
105 	naddr p_net, p_mask;
106 	struct interface *ifp;
107 	struct parm parm;
108 	char *tracename = 0;
109 
110 
111 	/* Some shells are badly broken and send SIGHUP to backgrounded
112 	 * processes.
113 	 */
114 	signal(SIGHUP, SIG_IGN);
115 
116 	openlog("routed", LOG_PID | LOG_ODELAY, LOG_DAEMON);
117 	ftrace = stdout;
118 
119 	gettimeofday(&clk, 0);
120 	prev_clk = clk;
121 	epoch = clk;
122 	epoch.tv_sec -= EPOCH;
123 	now.tv_sec = EPOCH;
124 	now_stale = EPOCH - STALE_TIME;
125 	now_expire = EPOCH - EXPIRE_TIME;
126 	now_garbage = EPOCH - GARBAGE_TIME;
127 	wtime.tv_sec = 0;
128 
129 	gethostname(myname, sizeof(myname)-1);
130 	gethost(myname, &myaddr);
131 
132 	while ((n = getopt(argc, argv, "sqdghmpAtvT:F:P:")) != -1) {
133 		switch (n) {
134 		case 's':
135 			supplier = 1;
136 			supplier_set = 1;
137 			break;
138 
139 		case 'q':
140 			supplier = 0;
141 			supplier_set = 1;
142 			break;
143 
144 		case 'd':
145 			background = 0;
146 			break;
147 
148 		case 'g':
149 			memset(&parm, 0, sizeof(parm));
150 			parm.parm_d_metric = 1;
151 			cp = check_parms(&parm);
152 			if (cp != 0)
153 				msglog("bad -g: %s", cp);
154 			else
155 				default_gateway = 1;
156 			break;
157 
158 		case 'h':		/* suppress extra host routes */
159 			ridhosts = 1;
160 			break;
161 
162 		case 'm':		/* advertise host route */
163 			mhome = 1;	/* on multi-homed hosts */
164 			break;
165 
166 		case 'A':
167 			/* Ignore authentication if we do not care.
168 			 * Crazy as it is, that is what RFC 1723 requires.
169 			 */
170 			auth_ok = 0;
171 			break;
172 
173 		case 't':
174 			new_tracelevel++;
175 			break;
176 
177 		case 'T':
178 			tracename = optarg;
179 			break;
180 
181 		case 'F':		/* minimal routes for SLIP */
182 			n = FAKE_METRIC;
183 			p = strchr(optarg,',');
184 			if (p && *p != '\0') {
185 				n = (int)strtoul(p+1, &q, 0);
186 				if (*q == '\0'
187 				    && n <= HOPCNT_INFINITY-1
188 				    && n >= 1)
189 					*p = '\0';
190 			}
191 			if (!getnet(optarg, &p_net, &p_mask)) {
192 				msglog("bad network; \"-F %s\"",
193 				       optarg);
194 				break;
195 			}
196 			memset(&parm, 0, sizeof(parm));
197 			parm.parm_net = p_net;
198 			parm.parm_mask = p_mask;
199 			parm.parm_d_metric = n;
200 			cp = check_parms(&parm);
201 			if (cp != 0)
202 				msglog("bad -F: %s", cp);
203 			break;
204 
205 		case 'P':
206 			/* handle arbitrary parameters.
207 			 */
208 			q = strdup(optarg);
209 			cp = parse_parms(q, 0);
210 			if (cp != 0)
211 				msglog("%s in \"-P %s\"", cp, optarg);
212 			free(q);
213 			break;
214 
215 		case 'v':
216 			/* display version */
217 			verbose++;
218 			msglog("version 2.22");
219 			break;
220 
221 		default:
222 			goto usage;
223 		}
224 	}
225 	argc -= optind;
226 	argv += optind;
227 
228 	if (tracename == 0 && argc >= 1) {
229 		tracename = *argv++;
230 		argc--;
231 	}
232 	if (tracename != 0 && tracename[0] == '\0')
233 		goto usage;
234 	if (argc != 0) {
235 usage:
236 		logbad(0, "usage: routed [-sqdghmpAtv] [-T tracefile]"
237 		       " [-F net[,metric]] [-P parms]");
238 	}
239 	if (geteuid() != 0) {
240 		if (verbose)
241 			exit(0);
242 		logbad(0, "requires UID 0");
243 	}
244 
245 	mib[0] = CTL_NET;
246 	mib[1] = PF_INET;
247 	mib[2] = IPPROTO_IP;
248 	mib[3] = IPCTL_FORWARDING;
249 	len = sizeof(ipforwarding);
250 	if (sysctl(mib, 4, &ipforwarding, &len, 0, 0) < 0)
251 		LOGERR("sysctl(IPCTL_FORWARDING)");
252 
253 	if (!ipforwarding) {
254 		if (supplier)
255 			msglog("-s incompatible with ipforwarding=0");
256 		if (default_gateway) {
257 			msglog("-g incompatible with ipforwarding=0");
258 			default_gateway = 0;
259 		}
260 		supplier = 0;
261 		supplier_set = 1;
262 	}
263 	if (default_gateway) {
264 		if (supplier_set && !supplier) {
265 			msglog("-g and -q incompatible");
266 		} else {
267 			supplier = 1;
268 			supplier_set = 1;
269 		}
270 	}
271 
272 
273 	signal(SIGALRM, sigalrm);
274 	if (!background)
275 		signal(SIGHUP, sigterm);    /* SIGHUP fatal during debugging */
276 	signal(SIGTERM, sigterm);
277 	signal(SIGINT, sigterm);
278 	signal(SIGUSR1, sigtrace_on);
279 	signal(SIGUSR2, sigtrace_off);
280 
281 	/* get into the background */
282 	if (background && daemon(0, 1) < 0)
283 		BADERR(0,"daemon()");
284 
285 	mypid = getpid();
286 	srandom((int)(clk.tv_sec ^ clk.tv_usec ^ mypid));
287 
288 	/* prepare socket connected to the kernel.
289 	 */
290 	rt_sock = socket(AF_ROUTE, SOCK_RAW, 0);
291 	if (rt_sock < 0)
292 		BADERR(1,"rt_sock = socket()");
293 	if (fcntl(rt_sock, F_SETFL, O_NONBLOCK) == -1)
294 		logbad(1, "fcntl(rt_sock) O_NONBLOCK: %s", strerror(errno));
295 	off = 0;
296 	if (setsockopt(rt_sock, SOL_SOCKET,SO_USELOOPBACK,
297 		       &off,sizeof(off)) < 0)
298 		LOGERR("setsockopt(SO_USELOOPBACK,0)");
299 
300 	fix_select();
301 
302 
303 	if (tracename != 0) {
304 		strncpy(inittracename, tracename, sizeof(inittracename)-1);
305 		set_tracefile(inittracename, "%s", -1);
306 	} else {
307 		tracelevel_msg("%s", -1);   /* turn on tracing to stdio */
308 	}
309 
310 	bufinit();
311 
312 	/* initialize radix tree */
313 	rtinit();
314 
315 	/* Pick a random part of the second for our output to minimize
316 	 * collisions.
317 	 *
318 	 * Start broadcasting after hearing from other routers, and
319 	 * at a random time so a bunch of systems do not get synchronized
320 	 * after a power failure.
321 	 */
322 	intvl_random(&next_bcast, EPOCH+MIN_WAITTIME, EPOCH+SUPPLY_INTERVAL);
323 	age_timer.tv_usec = next_bcast.tv_usec;
324 	age_timer.tv_sec = EPOCH+MIN_WAITTIME;
325 	rdisc_timer = next_bcast;
326 	ifinit_timer.tv_usec = next_bcast.tv_usec;
327 
328 	/* Collect an initial view of the world by checking the interface
329 	 * configuration and the kludge file.
330 	 */
331 	gwkludge();
332 	ifinit();
333 
334 	/* Ask for routes */
335 	rip_query();
336 	rdisc_sol();
337 
338 	/* Now turn off stdio if not tracing */
339 	if (new_tracelevel == 0)
340 		trace_close(background);
341 
342 	/* Loop forever, listening and broadcasting.
343 	 */
344 	for (;;) {
345 		prev_clk = clk;
346 		gettimeofday(&clk, 0);
347 		if (prev_clk.tv_sec == clk.tv_sec
348 		    && prev_clk.tv_usec == clk.tv_usec+usec_fudge) {
349 			/* Much of `routed` depends on time always advancing.
350 			 * On systems that do not guarantee that gettimeofday()
351 			 * produces unique timestamps even if called within
352 			 * a single tick, use trickery like that in classic
353 			 * BSD kernels.
354 			 */
355 			clk.tv_usec += ++usec_fudge;
356 
357 		} else {
358 			usec_fudge = 0;
359 
360 			timevalsub(&t2, &clk, &prev_clk);
361 			if (t2.tv_sec < 0
362 			    || t2.tv_sec > wtime.tv_sec + 5) {
363 				/* Deal with time changes before other
364 				 * housekeeping to keep everything straight.
365 				 */
366 				dt = t2.tv_sec;
367 				if (dt > 0)
368 					dt -= wtime.tv_sec;
369 				trace_act("time changed by %d sec", (int)dt);
370 				epoch.tv_sec += dt;
371 			}
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 UNUSED)
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 	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; NULL != 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 	 const 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 in;
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(&in, 0, sizeof(in));
638 #ifdef _HAVE_SIN_LEN
639 	in.sin_len = sizeof(in);
640 #endif
641 	in.sin_family = AF_INET;
642 	in.sin_port = htons(RIP_PORT);
643 	in.sin_addr.s_addr = addr;
644 	if (bind(s, (struct sockaddr *)&in, sizeof(in)) < 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 		close(rip_sock);
672 		rip_sock = -1;
673 
674 		/* get non-broadcast sockets to listen to queries.
675 		 */
676 		for (ifp = ifnet; ifp != NULL; 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 != NULL)
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 != NULL; ifp = ifp->int_next) {
746 			if (ifp->int_rip_sock >= 0) {
747 				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 = NULL;
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 != NULL; 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 != NULL
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 	 const char *msg)
784 {
785 	void *p = malloc(size);
786 	if (p == NULL)
787 		logbad(1,"malloc(%lu) failed in %s", (u_long)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(const 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 			fputs("routed: ", ftrace);
849 		vfprintf(ftrace, p, args);
850 		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, const char *p, ...)
864 {
865 	va_list args;
866 	int i;
867 	struct msg_sub *ms1, *ms;
868 	const 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 = NULL;
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 = NULL;
894 			break;
895 		}
896 		if (ms->until < ms1->until)
897 			ms = ms1;
898 	}
899 	if (ms != NULL) {
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 		vfprintf(ftrace, p, args);
912 		fputc('\n', ftrace);
913 	}
914 }
915 
916 
917 void
918 logbad(int dump, const 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 	fputs("routed: ", stderr);
928 	vfprintf(stderr, p, args);
929 	fputs("; giving up\n",stderr);
930 	fflush(stderr);
931 
932 	if (dump)
933 		abort();
934 	exit(1);
935 }
936