xref: /dragonfly/sbin/routed/main.c (revision b40e316c)
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. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgment:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * $FreeBSD: src/sbin/routed/main.c,v 1.11.2.1 2000/08/14 17:00:03 sheldonh Exp $
34  * $DragonFly: src/sbin/routed/main.c,v 1.3 2004/12/18 21:43:40 swildner Exp $
35  */
36 
37 #include "defs.h"
38 #include "pathnames.h"
39 #ifdef sgi
40 #include "math.h"
41 #endif
42 #include <signal.h>
43 #include <fcntl.h>
44 #include <sys/file.h>
45 
46 #if !defined(sgi) && !defined(__NetBSD__)
47 char copyright[] =
48 "@(#) Copyright (c) 1983, 1988, 1993\n\
49 	The Regents of the University of California.  All rights reserved.\n";
50 static char sccsid[] __attribute__((unused)) = "@(#)main.c	8.1 (Berkeley) 6/5/93";
51 #elif defined(__NetBSD__)
52 __RCSID("$NetBSD$");
53 __COPYRIGHT("@(#) Copyright (c) 1983, 1988, 1993\n\
54 	The Regents of the University of California.  All rights reserved.\n");
55 #endif
56 #ident "$FreeBSD: src/sbin/routed/main.c,v 1.11.2.1 2000/08/14 17:00:03 sheldonh Exp $"
57 
58 
59 pid_t	mypid;
60 
61 naddr	myaddr;				/* system address */
62 char	myname[MAXHOSTNAMELEN+1];
63 
64 int	verbose;
65 
66 int	supplier;			/* supply or broadcast updates */
67 int	supplier_set;
68 int	ipforwarding = 1;		/* kernel forwarding on */
69 
70 int	default_gateway;		/* 1=advertise default */
71 int	background = 1;
72 int	ridhosts;			/* 1=reduce host routes */
73 int	mhome;				/* 1=want multi-homed host route */
74 int	advertise_mhome;		/* 1=must continue advertising it */
75 int	auth_ok = 1;			/* 1=ignore auth if we do not care */
76 
77 struct timeval epoch;			/* when started */
78 struct timeval clk, prev_clk;
79 static int usec_fudge;
80 struct timeval now;			/* current idea of time */
81 time_t	now_stale;
82 time_t	now_expire;
83 time_t	now_garbage;
84 
85 struct timeval next_bcast;		/* next general broadcast */
86 struct timeval no_flash = {		/* inhibit flash update */
87 	EPOCH+SUPPLY_INTERVAL, 0
88 };
89 
90 struct timeval flush_kern_timer;
91 
92 fd_set	fdbits;
93 int	sock_max;
94 int	rip_sock = -1;			/* RIP socket */
95 struct interface *rip_sock_mcast;	/* current multicast interface */
96 int	rt_sock;			/* routing socket */
97 int	rt_sock_seqno;
98 
99 
100 static  int get_rip_sock(naddr, int);
101 static void timevalsub(struct timeval *, struct timeval *, struct timeval *);
102 
103 int
104 main(int argc,
105      char *argv[])
106 {
107 	int n, mib[4], off;
108 	size_t len;
109 	char *p, *q;
110 	const char *cp;
111 	struct timeval wtime, t2;
112 	time_t dt;
113 	fd_set ibits;
114 	naddr p_net, p_mask;
115 	struct interface *ifp;
116 	struct parm parm;
117 	char *tracename = 0;
118 
119 
120 	/* Some shells are badly broken and send SIGHUP to backgrounded
121 	 * processes.
122 	 */
123 	signal(SIGHUP, SIG_IGN);
124 
125 	openlog("routed", LOG_PID | LOG_ODELAY, LOG_DAEMON);
126 	ftrace = stdout;
127 
128 	gettimeofday(&clk, 0);
129 	prev_clk = clk;
130 	epoch = clk;
131 	epoch.tv_sec -= EPOCH;
132 	now.tv_sec = EPOCH;
133 	now_stale = EPOCH - STALE_TIME;
134 	now_expire = EPOCH - EXPIRE_TIME;
135 	now_garbage = EPOCH - GARBAGE_TIME;
136 	wtime.tv_sec = 0;
137 
138 	gethostname(myname, sizeof(myname)-1);
139 	gethost(myname, &myaddr);
140 
141 	while ((n = getopt(argc, argv, "sqdghmpAtvT:F:P:")) != -1) {
142 		switch (n) {
143 		case 's':
144 			supplier = 1;
145 			supplier_set = 1;
146 			break;
147 
148 		case 'q':
149 			supplier = 0;
150 			supplier_set = 1;
151 			break;
152 
153 		case 'd':
154 			background = 0;
155 			break;
156 
157 		case 'g':
158 			memset(&parm, 0, sizeof(parm));
159 			parm.parm_d_metric = 1;
160 			cp = check_parms(&parm);
161 			if (cp != 0)
162 				msglog("bad -g: %s", cp);
163 			else
164 				default_gateway = 1;
165 			break;
166 
167 		case 'h':		/* suppress extra host routes */
168 			ridhosts = 1;
169 			break;
170 
171 		case 'm':		/* advertise host route */
172 			mhome = 1;	/* on multi-homed hosts */
173 			break;
174 
175 		case 'A':
176 			/* Ignore authentication if we do not care.
177 			 * Crazy as it is, that is what RFC 1723 requires.
178 			 */
179 			auth_ok = 0;
180 			break;
181 
182 		case 't':
183 			new_tracelevel++;
184 			break;
185 
186 		case 'T':
187 			tracename = optarg;
188 			break;
189 
190 		case 'F':		/* minimal routes for SLIP */
191 			n = FAKE_METRIC;
192 			p = strchr(optarg,',');
193 			if (p && *p != '\0') {
194 				n = (int)strtoul(p+1, &q, 0);
195 				if (*q == '\0'
196 				    && n <= HOPCNT_INFINITY-1
197 				    && n >= 1)
198 					*p = '\0';
199 			}
200 			if (!getnet(optarg, &p_net, &p_mask)) {
201 				msglog("bad network; \"-F %s\"",
202 				       optarg);
203 				break;
204 			}
205 			memset(&parm, 0, sizeof(parm));
206 			parm.parm_net = p_net;
207 			parm.parm_mask = p_mask;
208 			parm.parm_d_metric = n;
209 			cp = check_parms(&parm);
210 			if (cp != 0)
211 				msglog("bad -F: %s", cp);
212 			break;
213 
214 		case 'P':
215 			/* handle arbitrary parameters.
216 			 */
217 			q = strdup(optarg);
218 			cp = parse_parms(q, 0);
219 			if (cp != 0)
220 				msglog("%s in \"-P %s\"", cp, optarg);
221 			free(q);
222 			break;
223 
224 		case 'v':
225 			/* display version */
226 			verbose++;
227 			msglog("version 2.22");
228 			break;
229 
230 		default:
231 			goto usage;
232 		}
233 	}
234 	argc -= optind;
235 	argv += optind;
236 
237 	if (tracename == 0 && argc >= 1) {
238 		tracename = *argv++;
239 		argc--;
240 	}
241 	if (tracename != 0 && tracename[0] == '\0')
242 		goto usage;
243 	if (argc != 0) {
244 usage:
245 		logbad(0, "usage: routed [-sqdghmpAtv] [-T tracefile]"
246 		       " [-F net[,metric]] [-P parms]");
247 	}
248 	if (geteuid() != 0) {
249 		if (verbose)
250 			exit(0);
251 		logbad(0, "requires UID 0");
252 	}
253 
254 	mib[0] = CTL_NET;
255 	mib[1] = PF_INET;
256 	mib[2] = IPPROTO_IP;
257 	mib[3] = IPCTL_FORWARDING;
258 	len = sizeof(ipforwarding);
259 	if (sysctl(mib, 4, &ipforwarding, &len, 0, 0) < 0)
260 		LOGERR("sysctl(IPCTL_FORWARDING)");
261 
262 	if (!ipforwarding) {
263 		if (supplier)
264 			msglog("-s incompatible with ipforwarding=0");
265 		if (default_gateway) {
266 			msglog("-g incompatible with ipforwarding=0");
267 			default_gateway = 0;
268 		}
269 		supplier = 0;
270 		supplier_set = 1;
271 	}
272 	if (default_gateway) {
273 		if (supplier_set && !supplier) {
274 			msglog("-g and -q incompatible");
275 		} else {
276 			supplier = 1;
277 			supplier_set = 1;
278 		}
279 	}
280 
281 
282 	signal(SIGALRM, sigalrm);
283 	if (!background)
284 		signal(SIGHUP, sigterm);    /* SIGHUP fatal during debugging */
285 	signal(SIGTERM, sigterm);
286 	signal(SIGINT, sigterm);
287 	signal(SIGUSR1, sigtrace_on);
288 	signal(SIGUSR2, sigtrace_off);
289 
290 	/* get into the background */
291 #ifdef sgi
292 	if (0 > _daemonize(background ? 0 : (_DF_NOCHDIR|_DF_NOFORK),
293 			   STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO))
294 		BADERR(0, "_daemonize()");
295 #else
296 	if (background && daemon(0, 1) < 0)
297 		BADERR(0,"daemon()");
298 #endif
299 
300 	mypid = getpid();
301 	srandom((int)(clk.tv_sec ^ clk.tv_usec ^ mypid));
302 
303 	/* prepare socket connected to the kernel.
304 	 */
305 	rt_sock = socket(AF_ROUTE, SOCK_RAW, 0);
306 	if (rt_sock < 0)
307 		BADERR(1,"rt_sock = socket()");
308 	if (fcntl(rt_sock, F_SETFL, O_NONBLOCK) == -1)
309 		logbad(1, "fcntl(rt_sock) O_NONBLOCK: %s", strerror(errno));
310 	off = 0;
311 	if (setsockopt(rt_sock, SOL_SOCKET,SO_USELOOPBACK,
312 		       &off,sizeof(off)) < 0)
313 		LOGERR("setsockopt(SO_USELOOPBACK,0)");
314 
315 	fix_select();
316 
317 
318 	if (tracename != 0) {
319 		strncpy(inittracename, tracename, sizeof(inittracename)-1);
320 		set_tracefile(inittracename, "%s", -1);
321 	} else {
322 		tracelevel_msg("%s", -1);   /* turn on tracing to stdio */
323 	}
324 
325 	bufinit();
326 
327 	/* initialize radix tree */
328 	rtinit();
329 
330 	/* Pick a random part of the second for our output to minimize
331 	 * collisions.
332 	 *
333 	 * Start broadcasting after hearing from other routers, and
334 	 * at a random time so a bunch of systems do not get synchronized
335 	 * after a power failure.
336 	 */
337 	intvl_random(&next_bcast, EPOCH+MIN_WAITTIME, EPOCH+SUPPLY_INTERVAL);
338 	age_timer.tv_usec = next_bcast.tv_usec;
339 	age_timer.tv_sec = EPOCH+MIN_WAITTIME;
340 	rdisc_timer = next_bcast;
341 	ifinit_timer.tv_usec = next_bcast.tv_usec;
342 
343 	/* Collect an initial view of the world by checking the interface
344 	 * configuration and the kludge file.
345 	 */
346 	gwkludge();
347 	ifinit();
348 
349 	/* Ask for routes */
350 	rip_query();
351 	rdisc_sol();
352 
353 	/* Now turn off stdio if not tracing */
354 	if (new_tracelevel == 0)
355 		trace_close(background);
356 
357 	/* Loop forever, listening and broadcasting.
358 	 */
359 	for (;;) {
360 		prev_clk = clk;
361 		gettimeofday(&clk, 0);
362 		if (prev_clk.tv_sec == clk.tv_sec
363 		    && prev_clk.tv_usec == clk.tv_usec+usec_fudge) {
364 			/* Much of `routed` depends on time always advancing.
365 			 * On systems that do not guarantee that gettimeofday()
366 			 * produces unique timestamps even if called within
367 			 * a single tick, use trickery like that in classic
368 			 * BSD kernels.
369 			 */
370 			clk.tv_usec += ++usec_fudge;
371 
372 		} else {
373 			usec_fudge = 0;
374 
375 			timevalsub(&t2, &clk, &prev_clk);
376 			if (t2.tv_sec < 0
377 			    || t2.tv_sec > wtime.tv_sec + 5) {
378 				/* Deal with time changes before other
379 				 * housekeeping to keep everything straight.
380 				 */
381 				dt = t2.tv_sec;
382 				if (dt > 0)
383 					dt -= wtime.tv_sec;
384 				trace_act("time changed by %d sec", (int)dt);
385 				epoch.tv_sec += dt;
386 			}
387 		}
388 		timevalsub(&now, &clk, &epoch);
389 		now_stale = now.tv_sec - STALE_TIME;
390 		now_expire = now.tv_sec - EXPIRE_TIME;
391 		now_garbage = now.tv_sec - GARBAGE_TIME;
392 
393 		/* deal with signals that should affect tracing */
394 		set_tracelevel();
395 
396 		if (stopint != 0) {
397 			rip_bcast(0);
398 			rdisc_adv();
399 			trace_off("exiting with signal %d", stopint);
400 			exit(stopint | 128);
401 		}
402 
403 		/* look for new or dead interfaces */
404 		timevalsub(&wtime, &ifinit_timer, &now);
405 		if (wtime.tv_sec <= 0) {
406 			wtime.tv_sec = 0;
407 			ifinit();
408 			rip_query();
409 			continue;
410 		}
411 
412 		/* Check the kernel table occassionally for mysteriously
413 		 * evaporated routes
414 		 */
415 		timevalsub(&t2, &flush_kern_timer, &now);
416 		if (t2.tv_sec <= 0) {
417 			flush_kern();
418 			flush_kern_timer.tv_sec = (now.tv_sec
419 						   + CHECK_QUIET_INTERVAL);
420 			continue;
421 		}
422 		if (timercmp(&t2, &wtime, <))
423 			wtime = t2;
424 
425 		/* If it is time, then broadcast our routes.
426 		 */
427 		if (supplier || advertise_mhome) {
428 			timevalsub(&t2, &next_bcast, &now);
429 			if (t2.tv_sec <= 0) {
430 				/* Synchronize the aging and broadcast
431 				 * timers to minimize awakenings
432 				 */
433 				age(0);
434 
435 				rip_bcast(0);
436 
437 				/* It is desirable to send routing updates
438 				 * regularly.  So schedule the next update
439 				 * 30 seconds after the previous one was
440 				 * scheduled, instead of 30 seconds after
441 				 * the previous update was finished.
442 				 * Even if we just started after discovering
443 				 * a 2nd interface or were otherwise delayed,
444 				 * pick a 30-second aniversary of the
445 				 * original broadcast time.
446 				 */
447 				n = 1 + (0-t2.tv_sec)/SUPPLY_INTERVAL;
448 				next_bcast.tv_sec += n*SUPPLY_INTERVAL;
449 
450 				continue;
451 			}
452 
453 			if (timercmp(&t2, &wtime, <))
454 				wtime = t2;
455 		}
456 
457 		/* If we need a flash update, either do it now or
458 		 * set the delay to end when it is time.
459 		 *
460 		 * If we are within MIN_WAITTIME seconds of a full update,
461 		 * do not bother.
462 		 */
463 		if (need_flash
464 		    && supplier
465 		    && no_flash.tv_sec+MIN_WAITTIME < next_bcast.tv_sec) {
466 			/* accurate to the millisecond */
467 			if (!timercmp(&no_flash, &now, >))
468 				rip_bcast(1);
469 			timevalsub(&t2, &no_flash, &now);
470 			if (timercmp(&t2, &wtime, <))
471 				wtime = t2;
472 		}
473 
474 		/* trigger the main aging timer.
475 		 */
476 		timevalsub(&t2, &age_timer, &now);
477 		if (t2.tv_sec <= 0) {
478 			age(0);
479 			continue;
480 		}
481 		if (timercmp(&t2, &wtime, <))
482 			wtime = t2;
483 
484 		/* update the kernel routing table
485 		 */
486 		timevalsub(&t2, &need_kern, &now);
487 		if (t2.tv_sec <= 0) {
488 			age(0);
489 			continue;
490 		}
491 		if (timercmp(&t2, &wtime, <))
492 			wtime = t2;
493 
494 		/* take care of router discovery,
495 		 * but do it in the correct the millisecond
496 		 */
497 		if (!timercmp(&rdisc_timer, &now, >)) {
498 			rdisc_age(0);
499 			continue;
500 		}
501 		timevalsub(&t2, &rdisc_timer, &now);
502 		if (timercmp(&t2, &wtime, <))
503 			wtime = t2;
504 
505 
506 		/* wait for input or a timer to expire.
507 		 */
508 		trace_flush();
509 		ibits = fdbits;
510 		n = select(sock_max, &ibits, 0, 0, &wtime);
511 		if (n <= 0) {
512 			if (n < 0 && errno != EINTR && errno != EAGAIN)
513 				BADERR(1,"select");
514 			continue;
515 		}
516 
517 		if (FD_ISSET(rt_sock, &ibits)) {
518 			read_rt();
519 			n--;
520 		}
521 		if (rdisc_sock >= 0 && FD_ISSET(rdisc_sock, &ibits)) {
522 			read_d();
523 			n--;
524 		}
525 		if (rip_sock >= 0 && FD_ISSET(rip_sock, &ibits)) {
526 			read_rip(rip_sock, 0);
527 			n--;
528 		}
529 
530 		for (ifp = ifnet; n > 0 && 0 != ifp; ifp = ifp->int_next) {
531 			if (ifp->int_rip_sock >= 0
532 			    && FD_ISSET(ifp->int_rip_sock, &ibits)) {
533 				read_rip(ifp->int_rip_sock, ifp);
534 				n--;
535 			}
536 		}
537 	}
538 }
539 
540 
541 /* ARGSUSED */
542 void
543 sigalrm(int s UNUSED)
544 {
545 	/* Historically, SIGALRM would cause the daemon to check for
546 	 * new and broken interfaces.
547 	 */
548 	ifinit_timer.tv_sec = now.tv_sec;
549 	trace_act("SIGALRM");
550 }
551 
552 
553 /* watch for fatal signals */
554 void
555 sigterm(int sig)
556 {
557 	stopint = sig;
558 	signal(sig, SIG_DFL);	/* catch it only once */
559 }
560 
561 
562 void
563 fix_select(void)
564 {
565 	struct interface *ifp;
566 
567 
568 	FD_ZERO(&fdbits);
569 	sock_max = 0;
570 
571 	FD_SET(rt_sock, &fdbits);
572 	if (sock_max <= rt_sock)
573 		sock_max = rt_sock+1;
574 	if (rip_sock >= 0) {
575 		FD_SET(rip_sock, &fdbits);
576 		if (sock_max <= rip_sock)
577 			sock_max = rip_sock+1;
578 	}
579 	for (ifp = ifnet; 0 != ifp; ifp = ifp->int_next) {
580 		if (ifp->int_rip_sock >= 0) {
581 			FD_SET(ifp->int_rip_sock, &fdbits);
582 			if (sock_max <= ifp->int_rip_sock)
583 				sock_max = ifp->int_rip_sock+1;
584 		}
585 	}
586 	if (rdisc_sock >= 0) {
587 		FD_SET(rdisc_sock, &fdbits);
588 		if (sock_max <= rdisc_sock)
589 			sock_max = rdisc_sock+1;
590 	}
591 }
592 
593 
594 void
595 fix_sock(int sock,
596 	 const char *name)
597 {
598 	int on;
599 #define MIN_SOCKBUF (4*1024)
600 	static int rbuf;
601 
602 	if (fcntl(sock, F_SETFL, O_NONBLOCK) == -1)
603 		logbad(1, "fcntl(%s) O_NONBLOCK: %s",
604 		       name, strerror(errno));
605 	on = 1;
606 	if (setsockopt(sock, SOL_SOCKET,SO_BROADCAST, &on,sizeof(on)) < 0)
607 		msglog("setsockopt(%s,SO_BROADCAST): %s",
608 		       name, strerror(errno));
609 #ifdef USE_PASSIFNAME
610 	on = 1;
611 	if (setsockopt(sock, SOL_SOCKET, SO_PASSIFNAME, &on,sizeof(on)) < 0)
612 		msglog("setsockopt(%s,SO_PASSIFNAME): %s",
613 		       name, strerror(errno));
614 #endif
615 
616 	if (rbuf >= MIN_SOCKBUF) {
617 		if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
618 			       &rbuf, sizeof(rbuf)) < 0)
619 			msglog("setsockopt(%s,SO_RCVBUF=%d): %s",
620 			       name, rbuf, strerror(errno));
621 	} else {
622 		for (rbuf = 60*1024; ; rbuf -= 4096) {
623 			if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
624 				       &rbuf, sizeof(rbuf)) == 0) {
625 				trace_act("RCVBUF=%d", rbuf);
626 				break;
627 			}
628 			if (rbuf < MIN_SOCKBUF) {
629 				msglog("setsockopt(%s,SO_RCVBUF = %d): %s",
630 				       name, rbuf, strerror(errno));
631 				break;
632 			}
633 		}
634 	}
635 }
636 
637 
638 /* get a rip socket
639  */
640 static int				/* <0 or file descriptor */
641 get_rip_sock(naddr addr,
642 	     int serious)		/* 1=failure to bind is serious */
643 {
644 	struct sockaddr_in sin;
645 	unsigned char ttl;
646 	int s;
647 
648 
649 	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
650 		BADERR(1,"rip_sock = socket()");
651 
652 	memset(&sin, 0, sizeof(sin));
653 #ifdef _HAVE_SIN_LEN
654 	sin.sin_len = sizeof(sin);
655 #endif
656 	sin.sin_family = AF_INET;
657 	sin.sin_port = htons(RIP_PORT);
658 	sin.sin_addr.s_addr = addr;
659 	if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
660 		if (serious)
661 			BADERR(errno != EADDRINUSE, "bind(rip_sock)");
662 		return -1;
663 	}
664 	fix_sock(s,"rip_sock");
665 
666 	ttl = 1;
667 	if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL,
668 		       &ttl, sizeof(ttl)) < 0)
669 		DBGERR(1,"rip_sock setsockopt(IP_MULTICAST_TTL)");
670 
671 	return s;
672 }
673 
674 
675 /* turn off main RIP socket */
676 void
677 rip_off(void)
678 {
679 	struct interface *ifp;
680 	naddr addr;
681 
682 
683 	if (rip_sock >= 0 && !mhome) {
684 		trace_act("turn off RIP");
685 
686 		close(rip_sock);
687 		rip_sock = -1;
688 
689 		/* get non-broadcast sockets to listen to queries.
690 		 */
691 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
692 			if (ifp->int_state & IS_REMOTE)
693 				continue;
694 			if (ifp->int_rip_sock < 0) {
695 				addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
696 					? ifp->int_dstaddr
697 					: ifp->int_addr);
698 				ifp->int_rip_sock = get_rip_sock(addr, 0);
699 			}
700 		}
701 
702 		fix_select();
703 
704 		age(0);
705 	}
706 }
707 
708 
709 /* turn on RIP multicast input via an interface
710  */
711 static void
712 rip_mcast_on(struct interface *ifp)
713 {
714 	struct ip_mreq m;
715 
716 	if (!IS_RIP_IN_OFF(ifp->int_state)
717 	    && (ifp->int_if_flags & IFF_MULTICAST)
718 #ifdef MCAST_PPP_BUG
719 	    && !(ifp->int_if_flags & IFF_POINTOPOINT)
720 #endif
721 	    && !(ifp->int_state & IS_ALIAS)) {
722 		m.imr_multiaddr.s_addr = htonl(INADDR_RIP_GROUP);
723 		m.imr_interface.s_addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
724 					  ? ifp->int_dstaddr
725 					  : ifp->int_addr);
726 		if (setsockopt(rip_sock,IPPROTO_IP, IP_ADD_MEMBERSHIP,
727 			       &m, sizeof(m)) < 0)
728 			LOGERR("setsockopt(IP_ADD_MEMBERSHIP RIP)");
729 	}
730 }
731 
732 
733 /* Prepare socket used for RIP.
734  */
735 void
736 rip_on(struct interface *ifp)
737 {
738 	/* If the main RIP socket is already alive, only start receiving
739 	 * multicasts for this interface.
740 	 */
741 	if (rip_sock >= 0) {
742 		if (ifp != 0)
743 			rip_mcast_on(ifp);
744 		return;
745 	}
746 
747 	/* If the main RIP socket is off and it makes sense to turn it on,
748 	 * then turn it on for all of the interfaces.
749 	 * It makes sense if either router discovery is off, or if
750 	 * router discover is on and at most one interface is doing RIP.
751 	 */
752 	if (rip_interfaces > 0 && (!rdisc_ok || rip_interfaces > 1)) {
753 		trace_act("turn on RIP");
754 
755 		/* Close all of the query sockets so that we can open
756 		 * the main socket.  SO_REUSEPORT is not a solution,
757 		 * since that would let two daemons bind to the broadcast
758 		 * socket.
759 		 */
760 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
761 			if (ifp->int_rip_sock >= 0) {
762 				close(ifp->int_rip_sock);
763 				ifp->int_rip_sock = -1;
764 			}
765 		}
766 
767 		rip_sock = get_rip_sock(INADDR_ANY, 1);
768 		rip_sock_mcast = 0;
769 
770 		/* Do not advertise anything until we have heard something
771 		 */
772 		if (next_bcast.tv_sec < now.tv_sec+MIN_WAITTIME)
773 			next_bcast.tv_sec = now.tv_sec+MIN_WAITTIME;
774 
775 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
776 			ifp->int_query_time = NEVER;
777 			rip_mcast_on(ifp);
778 		}
779 		ifinit_timer.tv_sec = now.tv_sec;
780 
781 	} else if (ifp != 0
782 		   && !(ifp->int_state & IS_REMOTE)
783 		   && ifp->int_rip_sock < 0) {
784 		/* RIP is off, so ensure there are sockets on which
785 		 * to listen for queries.
786 		 */
787 		ifp->int_rip_sock = get_rip_sock(ifp->int_addr, 0);
788 	}
789 
790 	fix_select();
791 }
792 
793 
794 /* die if malloc(3) fails
795  */
796 void *
797 rtmalloc(size_t size,
798 	 const char *msg)
799 {
800 	void *p = malloc(size);
801 	if (p == 0)
802 		logbad(1,"malloc(%lu) failed in %s", (u_long)size, msg);
803 	return p;
804 }
805 
806 
807 /* get a random instant in an interval
808  */
809 void
810 intvl_random(struct timeval *tp,	/* put value here */
811 	     u_long lo,			/* value is after this second */
812 	     u_long hi)			/* and before this */
813 {
814 	tp->tv_sec = (time_t)(hi == lo
815 			      ? lo
816 			      : (lo + random() % ((hi - lo))));
817 	tp->tv_usec = random() % 1000000;
818 }
819 
820 
821 void
822 timevaladd(struct timeval *t1,
823 	   struct timeval *t2)
824 {
825 
826 	t1->tv_sec += t2->tv_sec;
827 	if ((t1->tv_usec += t2->tv_usec) >= 1000000) {
828 		t1->tv_sec++;
829 		t1->tv_usec -= 1000000;
830 	}
831 }
832 
833 
834 /* t1 = t2 - t3
835  */
836 static void
837 timevalsub(struct timeval *t1,
838 	   struct timeval *t2,
839 	   struct timeval *t3)
840 {
841 	t1->tv_sec = t2->tv_sec - t3->tv_sec;
842 	if ((t1->tv_usec = t2->tv_usec - t3->tv_usec) < 0) {
843 		t1->tv_sec--;
844 		t1->tv_usec += 1000000;
845 	}
846 }
847 
848 
849 /* put a message into the system log
850  */
851 void
852 msglog(const char *p, ...)
853 {
854 	va_list args;
855 
856 	trace_flush();
857 
858 	va_start(args, p);
859 	vsyslog(LOG_ERR, p, args);
860 
861 	if (ftrace != 0) {
862 		if (ftrace == stdout)
863 			fputs("routed: ", ftrace);
864 		vfprintf(ftrace, p, args);
865 		fputc('\n', ftrace);
866 	}
867 }
868 
869 
870 /* Put a message about a bad system into the system log if
871  * we have not complained about it recently.
872  *
873  * It is desirable to complain about all bad systems, but not too often.
874  * In the worst case, it is not practical to keep track of all bad systems.
875  * For example, there can be many systems with the wrong password.
876  */
877 void
878 msglim(struct msg_limit *lim, naddr addr, const char *p, ...)
879 {
880 	va_list args;
881 	int i;
882 	struct msg_sub *ms1, *ms;
883 	const char *p1;
884 
885 	va_start(args, p);
886 
887 	/* look for the oldest slot in the table
888 	 * or the slot for the bad router.
889 	 */
890 	ms = ms1 = lim->subs;
891 	for (i = MSG_SUBJECT_N; ; i--, ms1++) {
892 		if (i == 0) {
893 			/* Reuse a slot at most once every 10 minutes.
894 			 */
895 			if (lim->reuse > now.tv_sec) {
896 				ms = 0;
897 			} else {
898 				ms = ms1;
899 				lim->reuse = now.tv_sec + 10*60;
900 			}
901 			break;
902 		}
903 		if (ms->addr == addr) {
904 			/* Repeat a complaint about a given system at
905 			 * most once an hour.
906 			 */
907 			if (ms->until > now.tv_sec)
908 				ms = 0;
909 			break;
910 		}
911 		if (ms->until < ms1->until)
912 			ms = ms1;
913 	}
914 	if (ms != 0) {
915 		ms->addr = addr;
916 		ms->until = now.tv_sec + 60*60;	/* 60 minutes */
917 
918 		trace_flush();
919 		for (p1 = p; *p1 == ' '; p1++)
920 			continue;
921 		vsyslog(LOG_ERR, p1, args);
922 	}
923 
924 	/* always display the message if tracing */
925 	if (ftrace != 0) {
926 		vfprintf(ftrace, p, args);
927 		fputc('\n', ftrace);
928 	}
929 }
930 
931 
932 void
933 logbad(int dump, const char *p, ...)
934 {
935 	va_list args;
936 
937 	trace_flush();
938 
939 	va_start(args, p);
940 	vsyslog(LOG_ERR, p, args);
941 
942 	fputs("routed: ", stderr);
943 	vfprintf(stderr, p, args);
944 	fputs("; giving up\n",stderr);
945 	fflush(stderr);
946 
947 	if (dump)
948 		abort();
949 	exit(1);
950 }
951