xref: /netbsd-src/sbin/routed/main.c (revision 2e9df72ec394f443f02e2e3b5922bfdfe348dab9)
1 /*	$NetBSD: main.c,v 1.43 2022/04/07 19:33:37 andvar 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 #include "defs.h"
37 #include "pathnames.h"
38 #if defined(__NetBSD__)
39 #include <util.h>
40 #endif
41 #include <signal.h>
42 #include <fcntl.h>
43 #include <sys/file.h>
44 
45 __COPYRIGHT("@(#) Copyright (c) 1983, 1988, 1993\
46  The Regents of the University of California.  All rights reserved.");
47 #ifdef __NetBSD__
48 __RCSID("$NetBSD: main.c,v 1.43 2022/04/07 19:33:37 andvar Exp $");
49 #elif defined(__FreeBSD__)
50 __RCSID("$FreeBSD$");
51 #else
52 __RCSID("Revision: 2.27 ");
53 #ident "Revision: 2.27 "
54 #endif
55 
56 pid_t	mypid;
57 
58 naddr	myaddr;				/* system address */
59 char	myname[MAXHOSTNAMELEN+1];
60 
61 int	verbose;
62 
63 int	supplier;			/* supply or broadcast updates */
64 int	supplier_set;
65 int	ipforwarding = 1;		/* kernel forwarding on */
66 
67 int	default_gateway;		/* 1=advertise default */
68 int	background = 1;
69 int	ridhosts;			/* 1=reduce host routes */
70 int	mhome;				/* 1=want multi-homed host route */
71 int	advertise_mhome;		/* 1=must continue advertising it */
72 int	auth_ok = 1;			/* 1=ignore auth if we do not care */
73 
74 struct timeval epoch;			/* when started */
75 struct timeval clk, prev_clk;
76 static int usec_fudge;
77 struct timeval now;			/* current idea of time */
78 time_t	now_stale;
79 time_t	now_expire;
80 time_t	now_garbage;
81 
82 struct timeval next_bcast;		/* next general broadcast */
83 struct timeval no_flash = {		/* inhibit flash update */
84 	EPOCH+SUPPLY_INTERVAL, 0
85 };
86 
87 struct timeval flush_kern_timer;
88 
89 fd_set	*fdbitsp;
90 int	sock_max;
91 int	rip_sock = -1;			/* RIP socket */
92 struct interface *rip_sock_mcast;	/* current multicast interface */
93 int	rt_sock;			/* routing socket */
94 int	rt_sock_seqno;
95 
96 
97 static  int get_rip_sock(naddr, int);
98 static void timevalsub(struct timeval *, struct timeval *, struct timeval *);
99 
100 int
main(int argc,char * argv[])101 main(int argc,
102      char *argv[])
103 {
104 	int n, mib[4], off;
105 	size_t len;
106 	char *p, *q;
107 	const char *cp;
108 	struct timeval wtime, t2;
109 	time_t dt;
110 	fd_set *ibitsp = NULL;
111 	naddr p_net, p_mask;
112 	struct interface *ifp;
113 	struct parm parm;
114 	char *tracename = 0;
115 
116 
117 	/* Some shells are badly broken and send SIGHUP to backgrounded
118 	 * processes.
119 	 */
120 	signal(SIGHUP, SIG_IGN);
121 
122 	openlog("routed", LOG_PID, LOG_DAEMON);
123 	ftrace = stdout;
124 
125 	gettimeofday(&clk, 0);
126 	prev_clk = clk;
127 	epoch = clk;
128 	epoch.tv_sec -= EPOCH;
129 	now.tv_sec = EPOCH;
130 	now_stale = EPOCH - STALE_TIME;
131 	now_expire = EPOCH - EXPIRE_TIME;
132 	now_garbage = EPOCH - GARBAGE_TIME;
133 	wtime.tv_sec = 0;
134 
135 	(void)gethostname(myname, sizeof(myname) - 1);
136 	(void)gethost(myname, &myaddr);
137 
138 	while ((n = getopt(argc, argv, "sqdghmAtvT:F:P:")) != -1) {
139 		switch (n) {
140 		case 's':
141 			supplier = 1;
142 			supplier_set = 1;
143 			break;
144 
145 		case 'q':
146 			supplier = 0;
147 			supplier_set = 1;
148 			break;
149 
150 		case 'd':
151 			background = 0;
152 			break;
153 
154 		case 'g':
155 			memset(&parm, 0, sizeof(parm));
156 			parm.parm_d_metric = 1;
157 			cp = check_parms(&parm);
158 			if (cp != 0)
159 				msglog("bad -g: %s", cp);
160 			else
161 				default_gateway = 1;
162 			break;
163 
164 		case 'h':		/* suppress extra host routes */
165 			ridhosts = 1;
166 			break;
167 
168 		case 'm':		/* advertise host route */
169 			mhome = 1;	/* on multi-homed hosts */
170 			break;
171 
172 		case 'A':
173 			/* Ignore authentication if we do not care.
174 			 * Crazy as it is, that is what RFC 1723 requires.
175 			 */
176 			auth_ok = 0;
177 			break;
178 
179 		case 't':
180 			new_tracelevel++;
181 			break;
182 
183 		case 'T':
184 			tracename = optarg;
185 			break;
186 
187 		case 'F':		/* minimal routes for SLIP */
188 			n = FAKE_METRIC;
189 			p = strchr(optarg,',');
190 			if (p && *p != '\0') {
191 				n = (int)strtoul(p+1, &q, 0);
192 				if (*q == '\0'
193 				    && n <= HOPCNT_INFINITY-1
194 				    && n >= 1)
195 					*p = '\0';
196 			}
197 			if (!getnet(optarg, &p_net, &p_mask)) {
198 				msglog("bad network; \"-F %s\"",
199 				       optarg);
200 				break;
201 			}
202 			memset(&parm, 0, sizeof(parm));
203 			parm.parm_net = p_net;
204 			parm.parm_mask = p_mask;
205 			parm.parm_d_metric = n;
206 			cp = check_parms(&parm);
207 			if (cp != 0)
208 				msglog("bad -F: %s", cp);
209 			break;
210 
211 		case 'P':
212 			/* handle arbitrary parameters.
213 			 */
214 			q = strdup(optarg);
215 			cp = parse_parms(q, 0);
216 			if (cp != 0)
217 				msglog("%s in \"-P %s\"", cp, optarg);
218 			free(q);
219 			break;
220 
221 		case 'v':
222 			/* display version */
223 			verbose++;
224 			msglog("version 2.32");
225 			break;
226 
227 		default:
228 			goto usage;
229 		}
230 	}
231 	argc -= optind;
232 	argv += optind;
233 
234 	if (tracename == 0 && argc >= 1) {
235 		tracename = *argv++;
236 		argc--;
237 	}
238 	if (tracename != 0 && tracename[0] == '\0')
239 		goto usage;
240 	if (argc != 0) {
241 usage:
242 		logbad(0, "usage: routed [-sqdghmAtv] [-T tracefile]"
243 		       " [-F net[/mask[,metric]]] [-P parms]");
244 	}
245 	if (geteuid() != 0) {
246 		if (verbose)
247 			exit(0);
248 		logbad(0, "requires UID 0");
249 	}
250 
251 	mib[0] = CTL_NET;
252 	mib[1] = PF_INET;
253 	mib[2] = IPPROTO_IP;
254 	mib[3] = IPCTL_FORWARDING;
255 	len = sizeof(ipforwarding);
256 	if (sysctl(mib, 4, &ipforwarding, &len, 0, 0) < 0)
257 		LOGERR("sysctl(IPCTL_FORWARDING)");
258 
259 	if (!ipforwarding) {
260 		if (supplier)
261 			msglog("-s incompatible with ipforwarding=0");
262 		if (default_gateway) {
263 			msglog("-g incompatible with ipforwarding=0");
264 			default_gateway = 0;
265 		}
266 		supplier = 0;
267 		supplier_set = 1;
268 	}
269 	if (default_gateway) {
270 		if (supplier_set && !supplier) {
271 			msglog("-g and -q incompatible");
272 		} else {
273 			supplier = 1;
274 			supplier_set = 1;
275 		}
276 	}
277 
278 
279 	signal(SIGALRM, sigalrm);
280 	if (!background)
281 		signal(SIGHUP, sigterm);    /* SIGHUP fatal during debugging */
282 	signal(SIGTERM, sigterm);
283 	signal(SIGINT, sigterm);
284 	signal(SIGUSR1, sigtrace_on);
285 	signal(SIGUSR2, sigtrace_off);
286 
287 	/* get into the background */
288 	if (background && daemon(0, 1) < 0)
289 		BADERR(0,"daemon()");
290 
291 #if defined(__NetBSD__)
292 	pidfile(NULL);
293 #endif
294 	mypid = getpid();
295 
296 	/* prepare socket connected to the kernel.
297 	 */
298 	rt_sock = socket(AF_ROUTE, SOCK_RAW, 0);
299 	if (rt_sock < 0)
300 		BADERR(1,"rt_sock = socket()");
301 	if (fcntl(rt_sock, F_SETFL, O_NONBLOCK) == -1)
302 		logbad(1, "fcntl(rt_sock) O_NONBLOCK: %s", strerror(errno));
303 	off = 0;
304 	if (setsockopt(rt_sock, SOL_SOCKET,SO_USELOOPBACK,
305 		       &off,sizeof(off)) < 0)
306 		LOGERR("setsockopt(SO_USELOOPBACK,0)");
307 
308 	fix_select();
309 
310 
311 	if (tracename != 0) {
312 		strlcpy(inittracename, tracename, sizeof(inittracename));
313 		set_tracefile(inittracename, "%s", -1);
314 	} else {
315 		tracelevel_msg("%s", -1);   /* turn on tracing to stdio */
316 	}
317 
318 	bufinit();
319 
320 	/* initialize radix tree */
321 	rtinit();
322 
323 	/* Pick a random part of the second for our output to minimize
324 	 * collisions.
325 	 *
326 	 * Start broadcasting after hearing from other routers, and
327 	 * at a random time so a bunch of systems do not get synchronized
328 	 * after a power failure.
329 	 */
330 	intvl_random(&next_bcast, EPOCH+MIN_WAITTIME, EPOCH+SUPPLY_INTERVAL);
331 	age_timer.tv_usec = next_bcast.tv_usec;
332 	age_timer.tv_sec = EPOCH+MIN_WAITTIME;
333 	rdisc_timer = next_bcast;
334 	ifinit_timer.tv_usec = next_bcast.tv_usec;
335 
336 	/* Collect an initial view of the world by checking the interface
337 	 * configuration and the kludge file.
338 	 */
339 	gwkludge();
340 	ifinit();
341 
342 	/* Ask for routes */
343 	rip_query();
344 	rdisc_sol();
345 
346 	/* Now turn off stdio if not tracing */
347 	if (new_tracelevel == 0)
348 		trace_close(background);
349 
350 	/* Loop forever, listening and broadcasting.
351 	 */
352 	for (;;) {
353 		prev_clk = clk;
354 		gettimeofday(&clk, 0);
355 		if (prev_clk.tv_sec == clk.tv_sec
356 		    && prev_clk.tv_usec == clk.tv_usec+usec_fudge) {
357 			/* Much of `routed` depends on time always advancing.
358 			 * On systems that do not guarantee that gettimeofday()
359 			 * produces unique timestamps even if called within
360 			 * a single tick, use trickery like that in classic
361 			 * BSD kernels.
362 			 */
363 			clk.tv_usec += ++usec_fudge;
364 
365 		} else {
366 			usec_fudge = 0;
367 
368 			timevalsub(&t2, &clk, &prev_clk);
369 			if (t2.tv_sec < 0
370 			    || t2.tv_sec > wtime.tv_sec + 5) {
371 				/* Deal with time changes before other
372 				 * housekeeping to keep everything straight.
373 				 */
374 				dt = t2.tv_sec;
375 				if (dt > 0)
376 					dt -= wtime.tv_sec;
377 				trace_act("time changed by %d sec", (int)dt);
378 				epoch.tv_sec += dt;
379 			}
380 		}
381 		timevalsub(&now, &clk, &epoch);
382 		now_stale = now.tv_sec - STALE_TIME;
383 		now_expire = now.tv_sec - EXPIRE_TIME;
384 		now_garbage = now.tv_sec - GARBAGE_TIME;
385 
386 		/* deal with signals that should affect tracing */
387 		set_tracelevel();
388 
389 		if (stopint != 0) {
390 			rip_bcast(0);
391 			rdisc_adv();
392 			trace_off("exiting with signal %d", stopint);
393 			exit(stopint | 128);
394 		}
395 
396 		/* look for new or dead interfaces */
397 		timevalsub(&wtime, &ifinit_timer, &now);
398 		if (wtime.tv_sec <= 0) {
399 			wtime.tv_sec = 0;
400 			ifinit();
401 			rip_query();
402 			continue;
403 		}
404 
405 		/* Check the kernel table occasionally for mysteriously
406 		 * evaporated routes
407 		 */
408 		timevalsub(&t2, &flush_kern_timer, &now);
409 		if (t2.tv_sec <= 0) {
410 			flush_kern();
411 			flush_kern_timer.tv_sec = (now.tv_sec
412 						   + CHECK_QUIET_INTERVAL);
413 			continue;
414 		}
415 		if (timercmp(&t2, &wtime, <))
416 			wtime = t2;
417 
418 		/* If it is time, then broadcast our routes.
419 		 */
420 		if (supplier || advertise_mhome) {
421 			timevalsub(&t2, &next_bcast, &now);
422 			if (t2.tv_sec <= 0) {
423 				/* Synchronize the aging and broadcast
424 				 * timers to minimize awakenings
425 				 */
426 				age(0);
427 
428 				rip_bcast(0);
429 
430 				/* It is desirable to send routing updates
431 				 * regularly.  So schedule the next update
432 				 * 30 seconds after the previous one was
433 				 * scheduled, instead of 30 seconds after
434 				 * the previous update was finished.
435 				 * Even if we just started after discovering
436 				 * a 2nd interface or were otherwise delayed,
437 				 * pick a 30-second aniversary of the
438 				 * original broadcast time.
439 				 */
440 				n = 1 + (0-t2.tv_sec)/SUPPLY_INTERVAL;
441 				next_bcast.tv_sec += n*SUPPLY_INTERVAL;
442 
443 				continue;
444 			}
445 
446 			if (timercmp(&t2, &wtime, <))
447 				wtime = t2;
448 		}
449 
450 		/* If we need a flash update, either do it now or
451 		 * set the delay to end when it is time.
452 		 *
453 		 * If we are within MIN_WAITTIME seconds of a full update,
454 		 * do not bother.
455 		 */
456 		if (need_flash
457 		    && supplier
458 		    && no_flash.tv_sec+MIN_WAITTIME < next_bcast.tv_sec) {
459 			/* accurate to the millisecond */
460 			if (!timercmp(&no_flash, &now, >))
461 				rip_bcast(1);
462 			timevalsub(&t2, &no_flash, &now);
463 			if (timercmp(&t2, &wtime, <))
464 				wtime = t2;
465 		}
466 
467 		/* trigger the main aging timer.
468 		 */
469 		timevalsub(&t2, &age_timer, &now);
470 		if (t2.tv_sec <= 0) {
471 			age(0);
472 			continue;
473 		}
474 		if (timercmp(&t2, &wtime, <))
475 			wtime = t2;
476 
477 		/* update the kernel routing table
478 		 */
479 		timevalsub(&t2, &need_kern, &now);
480 		if (t2.tv_sec <= 0) {
481 			age(0);
482 			continue;
483 		}
484 		if (timercmp(&t2, &wtime, <))
485 			wtime = t2;
486 
487 		/* take care of router discovery,
488 		 * but do it in the correct the millisecond
489 		 */
490 		if (!timercmp(&rdisc_timer, &now, >)) {
491 			rdisc_age(0);
492 			continue;
493 		}
494 		timevalsub(&t2, &rdisc_timer, &now);
495 		if (timercmp(&t2, &wtime, <))
496 			wtime = t2;
497 
498 
499 		/* wait for input or a timer to expire.
500 		 */
501 		trace_flush();
502 		if (ibitsp)
503 			free(ibitsp);
504 		ibitsp = (fd_set *)calloc(howmany(sock_max, NFDBITS),
505 		    sizeof(fd_mask));
506 		if (ibitsp == NULL)
507 			BADERR(1, "calloc");
508 		memcpy(ibitsp, fdbitsp, howmany(sock_max, NFDBITS) *
509 		    sizeof(fd_mask));
510 		n = select(sock_max, ibitsp, 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, ibitsp)) {
518 			read_rt();
519 			n--;
520 		}
521 		if (rdisc_sock >= 0 && FD_ISSET(rdisc_sock, ibitsp)) {
522 			read_d();
523 			n--;
524 		}
525 		if (rip_sock >= 0 && FD_ISSET(rip_sock, ibitsp)) {
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, ibitsp)) {
533 				read_rip(ifp->int_rip_sock, ifp);
534 				n--;
535 			}
536 		}
537 	}
538 }
539 
540 
541 /* ARGSUSED */
542 void
sigalrm(int s UNUSED)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
sigterm(int sig)555 sigterm(int sig)
556 {
557 	stopint = sig;
558 	(void)signal(sig, SIG_DFL);	/* catch it only once */
559 }
560 
561 
562 void
fix_select(void)563 fix_select(void)
564 {
565 	struct interface *ifp;
566 
567 	sock_max = 0;
568 
569 	if (sock_max <= rt_sock)
570 		sock_max = rt_sock + 1;
571 	if (rip_sock >= 0)
572 		if (sock_max <= rip_sock)
573 			sock_max = rip_sock + 1;
574 	for (ifp = ifnet; 0 != ifp; ifp = ifp->int_next) {
575 		if (ifp->int_rip_sock >= 0)
576 			if (sock_max <= ifp->int_rip_sock)
577 				sock_max = ifp->int_rip_sock + 1;
578 	}
579 	if (rdisc_sock >= 0)
580 		if (sock_max <= rdisc_sock)
581 			sock_max = rdisc_sock + 1;
582 
583 	if (fdbitsp)
584 		free(fdbitsp);
585 	fdbitsp = (fd_set *)calloc(howmany(sock_max, NFDBITS),
586 	    sizeof(fd_mask));
587 	if (fdbitsp == NULL)
588 		BADERR(1, "calloc");
589 
590 	FD_SET(rt_sock, fdbitsp);
591 	if (rip_sock >= 0)
592 		FD_SET(rip_sock, fdbitsp);
593 	for (ifp = ifnet; 0 != ifp; ifp = ifp->int_next) {
594 		if (ifp->int_rip_sock >= 0)
595 			FD_SET(ifp->int_rip_sock, fdbitsp);
596 	}
597 	if (rdisc_sock >= 0)
598 		FD_SET(rdisc_sock, fdbitsp);
599 }
600 
601 
602 void
fix_sock(int sock,const char * name)603 fix_sock(int sock,
604 	 const char *name)
605 {
606 	int on;
607 #define MIN_SOCKBUF (4*1024)
608 	static int rbuf;
609 
610 	if (fcntl(sock, F_SETFL, O_NONBLOCK) == -1)
611 		logbad(1, "fcntl(%s) O_NONBLOCK: %s",
612 		       name, strerror(errno));
613 	on = 1;
614 	if (setsockopt(sock, SOL_SOCKET,SO_BROADCAST, &on,sizeof(on)) < 0)
615 		msglog("setsockopt(%s,SO_BROADCAST): %s",
616 		       name, strerror(errno));
617 #ifdef USE_PASSIFNAME
618 	on = 1;
619 	if (setsockopt(sock, SOL_SOCKET, SO_PASSIFNAME, &on,sizeof(on)) < 0)
620 		msglog("setsockopt(%s,SO_PASSIFNAME): %s",
621 		       name, strerror(errno));
622 #endif
623 
624 	if (rbuf >= MIN_SOCKBUF) {
625 		if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
626 			       &rbuf, sizeof(rbuf)) < 0)
627 			msglog("setsockopt(%s,SO_RCVBUF=%d): %s",
628 			       name, rbuf, strerror(errno));
629 	} else {
630 		for (rbuf = 60*1024; ; rbuf -= 4096) {
631 			if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
632 				       &rbuf, sizeof(rbuf)) == 0) {
633 				trace_act("RCVBUF=%d", rbuf);
634 				break;
635 			}
636 			if (rbuf < MIN_SOCKBUF) {
637 				msglog("setsockopt(%s,SO_RCVBUF = %d): %s",
638 				       name, rbuf, strerror(errno));
639 				break;
640 			}
641 		}
642 	}
643 }
644 
645 
646 /* get a rip socket
647  */
648 static int				/* <0 or file descriptor */
get_rip_sock(naddr addr,int serious)649 get_rip_sock(naddr addr,
650 	     int serious)		/* 1=failure to bind is serious */
651 {
652 	struct sockaddr_in rsin;
653 	unsigned char ttl;
654 	int s;
655 
656 
657 	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
658 		BADERR(1,"rip_sock = socket()");
659 
660 	memset(&rsin, 0, sizeof(rsin));
661 #ifdef _HAVE_SIN_LEN
662 	rsin.sin_len = sizeof(rsin);
663 #endif
664 	rsin.sin_family = AF_INET;
665 	rsin.sin_port = htons(RIP_PORT);
666 	rsin.sin_addr.s_addr = addr;
667 	if (bind(s, (struct sockaddr *)&rsin, sizeof(rsin)) < 0) {
668 		if (serious)
669 			BADERR(errno != EADDRINUSE, "bind(rip_sock)");
670 		return -1;
671 	}
672 	fix_sock(s,"rip_sock");
673 
674 	ttl = 1;
675 	if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL,
676 		       &ttl, sizeof(ttl)) < 0)
677 		DBGERR(1,"rip_sock setsockopt(IP_MULTICAST_TTL)");
678 
679 	return s;
680 }
681 
682 
683 /* turn off main RIP socket */
684 void
rip_off(void)685 rip_off(void)
686 {
687 	struct interface *ifp;
688 	naddr addr;
689 
690 
691 	if (rip_sock >= 0 && !mhome) {
692 		trace_act("turn off RIP");
693 
694 		(void)close(rip_sock);
695 		rip_sock = -1;
696 
697 		/* get non-broadcast sockets to listen to queries.
698 		 */
699 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
700 			if (ifp->int_state & IS_REMOTE)
701 				continue;
702 			if (ifp->int_rip_sock < 0) {
703 				addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
704 					? ifp->int_dstaddr
705 					: ifp->int_addr);
706 				ifp->int_rip_sock = get_rip_sock(addr, 0);
707 			}
708 		}
709 
710 		fix_select();
711 
712 		age(0);
713 	}
714 }
715 
716 
717 /* turn on RIP multicast input via an interface
718  */
719 static void
rip_mcast_on(struct interface * ifp)720 rip_mcast_on(struct interface *ifp)
721 {
722 	struct ip_mreq m;
723 
724 	if (!IS_RIP_IN_OFF(ifp->int_state)
725 	    && (ifp->int_if_flags & IFF_MULTICAST)
726 #ifdef MCAST_PPP_BUG
727 	    && !(ifp->int_if_flags & IFF_POINTOPOINT)
728 #endif
729 	    && !(ifp->int_state & IS_ALIAS)) {
730 		m.imr_multiaddr.s_addr = htonl(INADDR_RIP_GROUP);
731 #ifdef MCAST_IFINDEX
732 		m.imr_interface.s_addr = htonl(ifp->int_index);
733 #else
734 		m.imr_interface.s_addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
735 					  ? ifp->int_dstaddr
736 					  : ifp->int_addr);
737 #endif
738 		if (setsockopt(rip_sock,IPPROTO_IP, IP_ADD_MEMBERSHIP,
739 			       &m, sizeof(m)) < 0)
740 			LOGERR("setsockopt(IP_ADD_MEMBERSHIP RIP)");
741 	}
742 }
743 
744 
745 /* Prepare socket used for RIP.
746  */
747 void
rip_on(struct interface * ifp)748 rip_on(struct interface *ifp)
749 {
750 	/* If the main RIP socket is already alive, only start receiving
751 	 * multicasts for this interface.
752 	 */
753 	if (rip_sock >= 0) {
754 		if (ifp != 0)
755 			rip_mcast_on(ifp);
756 		return;
757 	}
758 
759 	/* If the main RIP socket is off and it makes sense to turn it on,
760 	 * then turn it on for all of the interfaces.
761 	 * It makes sense if either router discovery is off, or if
762 	 * router discover is on and at most one interface is doing RIP.
763 	 */
764 	if (rip_interfaces > 0 && (!rdisc_ok || rip_interfaces > 1)) {
765 		trace_act("turn on RIP");
766 
767 		/* Close all of the query sockets so that we can open
768 		 * the main socket.  SO_REUSEPORT is not a solution,
769 		 * since that would let two daemons bind to the broadcast
770 		 * socket.
771 		 */
772 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
773 			if (ifp->int_rip_sock >= 0) {
774 				(void)close(ifp->int_rip_sock);
775 				ifp->int_rip_sock = -1;
776 			}
777 		}
778 
779 		rip_sock = get_rip_sock(INADDR_ANY, 1);
780 		rip_sock_mcast = 0;
781 
782 		/* Do not advertise anything until we have heard something
783 		 */
784 		if (next_bcast.tv_sec < now.tv_sec+MIN_WAITTIME)
785 			next_bcast.tv_sec = now.tv_sec+MIN_WAITTIME;
786 
787 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
788 			ifp->int_query_time = NEVER;
789 			rip_mcast_on(ifp);
790 		}
791 		ifinit_timer.tv_sec = now.tv_sec;
792 
793 	} else if (ifp != 0
794 		   && !(ifp->int_state & IS_REMOTE)
795 		   && ifp->int_rip_sock < 0) {
796 		/* RIP is off, so ensure there are sockets on which
797 		 * to listen for queries.
798 		 */
799 		ifp->int_rip_sock = get_rip_sock(ifp->int_addr, 0);
800 	}
801 
802 	fix_select();
803 }
804 
805 
806 /* die if malloc(3) fails
807  */
808 void *
rtmalloc(size_t size,const char * msg)809 rtmalloc(size_t size,
810 	 const char *msg)
811 {
812 	void *p = malloc(size);
813 	if (p == 0)
814 		logbad(1,"malloc(%lu) failed in %s", (u_long)size, msg);
815 	return p;
816 }
817 
818 
819 /* get a random instant in an interval
820  */
821 void
intvl_random(struct timeval * tp,u_long lo,u_long hi)822 intvl_random(struct timeval *tp,	/* put value here */
823 	     u_long lo,			/* value is after this second */
824 	     u_long hi)			/* and before this */
825 {
826 	tp->tv_sec = (time_t)(hi == lo
827 			      ? lo
828 			      : (lo + arc4random() % ((hi - lo))));
829 	tp->tv_usec = arc4random() % 1000000;
830 }
831 
832 
833 void
timevaladd(struct timeval * t1,struct timeval * t2)834 timevaladd(struct timeval *t1,
835 	   struct timeval *t2)
836 {
837 
838 	t1->tv_sec += t2->tv_sec;
839 	if ((t1->tv_usec += t2->tv_usec) >= 1000000) {
840 		t1->tv_sec++;
841 		t1->tv_usec -= 1000000;
842 	}
843 }
844 
845 
846 /* t1 = t2 - t3
847  */
848 static void
timevalsub(struct timeval * t1,struct timeval * t2,struct timeval * t3)849 timevalsub(struct timeval *t1,
850 	   struct timeval *t2,
851 	   struct timeval *t3)
852 {
853 	t1->tv_sec = t2->tv_sec - t3->tv_sec;
854 	if ((t1->tv_usec = t2->tv_usec - t3->tv_usec) < 0) {
855 		t1->tv_sec--;
856 		t1->tv_usec += 1000000;
857 	}
858 }
859 
860 
861 /* put a message into the system log
862  */
863 void
msglog(const char * p,...)864 msglog(const char *p, ...)
865 {
866 	va_list args;
867 
868 	trace_flush();
869 
870 	va_start(args, p);
871 	vsyslog(LOG_ERR, p, args);
872 	va_end(args);
873 
874 	if (ftrace != 0) {
875 		if (ftrace == stdout)
876 			(void)fputs("routed: ", ftrace);
877 		va_start(args, p);
878 		(void)vfprintf(ftrace, p, args);
879 		va_end(args);
880 		(void)fputc('\n', ftrace);
881 	}
882 }
883 
884 
885 /* Put a message about a bad system into the system log if
886  * we have not complained about it recently.
887  *
888  * It is desirable to complain about all bad systems, but not too often.
889  * In the worst case, it is not practical to keep track of all bad systems.
890  * For example, there can be many systems with the wrong password.
891  */
892 void
msglim(struct msg_limit * lim,naddr addr,const char * p,...)893 msglim(struct msg_limit *lim, naddr addr, const char *p, ...)
894 {
895 	va_list args;
896 	int i;
897 	struct msg_sub *ms1, *ms;
898 	const char *p1;
899 
900 	/* look for the oldest slot in the table
901 	 * or the slot for the bad router.
902 	 */
903 	ms = ms1 = lim->subs;
904 	for (i = MSG_SUBJECT_N; ; i--, ms1++) {
905 		if (i == 0) {
906 			/* Reuse a slot at most once every 10 minutes.
907 			 */
908 			if (lim->reuse > now.tv_sec) {
909 				ms = 0;
910 			} else {
911 				ms = ms1;
912 				lim->reuse = now.tv_sec + 10*60;
913 			}
914 			break;
915 		}
916 		if (ms->addr == addr) {
917 			/* Repeat a complaint about a given system at
918 			 * most once an hour.
919 			 */
920 			if (ms->until > now.tv_sec)
921 				ms = 0;
922 			break;
923 		}
924 		if (ms->until < ms1->until)
925 			ms = ms1;
926 	}
927 	if (ms != 0) {
928 		ms->addr = addr;
929 		ms->until = now.tv_sec + 60*60;	/* 60 minutes */
930 
931 		trace_flush();
932 		for (p1 = p; *p1 == ' '; p1++)
933 			continue;
934 		va_start(args, p);
935 		vsyslog(LOG_ERR, p1, args);
936 		va_end(args);
937 	}
938 
939 	/* always display the message if tracing */
940 	if (ftrace != 0) {
941 		va_start(args, p);
942 		(void)vfprintf(ftrace, p, args);
943 		(void)fputc('\n', ftrace);
944 		va_end(args);
945 	}
946 }
947 
948 
949 void
logbad(int dump,const char * p,...)950 logbad(int dump, const char *p, ...)
951 {
952 	va_list args;
953 
954 	trace_flush();
955 
956 	va_start(args, p);
957 	vsyslog(LOG_ERR, p, args);
958 	va_end(args);
959 
960 	(void)fputs("routed: ", stderr);
961 	va_start(args, p);
962 	(void)vfprintf(stderr, p, args);
963 	va_end(args);
964 	(void)fputs("; giving up\n",stderr);
965 	(void)fflush(stderr);
966 
967 	if (dump)
968 		abort();
969 	exit(1);
970 }
971