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main.c revision 1.18
      1 /*	$NetBSD: main.c,v 1.18 1998/06/02 18:02:55 thorpej 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 acknowledgement:
     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 1.18 1998/06/02 18:02:55 thorpej 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 adverising 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)-1);
    137 	(void)gethost(myname, &myaddr);
    138 
    139 	while ((n = getopt(argc, argv, "sqdghmpAtvT:F:P:")) != -1) {
    140 		switch (n) {
    141 		case 's':
    142 			supplier = 1;
    143 			supplier_set = 1;
    144 			break;
    145 
    146 		case 'q':
    147 			supplier = 0;
    148 			supplier_set = 1;
    149 			break;
    150 
    151 		case 'd':
    152 			background = 0;
    153 			break;
    154 
    155 		case 'g':
    156 			memset(&parm, 0, sizeof(parm));
    157 			parm.parm_d_metric = 1;
    158 			p = check_parms(&parm);
    159 			if (p != 0)
    160 				msglog("bad -g: %s", p);
    161 			else
    162 				default_gateway = 1;
    163 			break;
    164 
    165 		case 'h':		/* suppress extra host routes */
    166 			ridhosts = 1;
    167 			break;
    168 
    169 		case 'm':		/* advertise host route */
    170 			mhome = 1;	/* on multi-homed hosts */
    171 			break;
    172 
    173 		case 'A':
    174 			/* Ignore authentication if we do not care.
    175 			 * Crazy as it is, that is what RFC 1723 requires.
    176 			 */
    177 			auth_ok = 0;
    178 			break;
    179 
    180 		case 't':
    181 			new_tracelevel++;
    182 			break;
    183 
    184 		case 'T':
    185 			tracename = optarg;
    186 			break;
    187 
    188 		case 'F':		/* minimal routes for SLIP */
    189 			n = FAKE_METRIC;
    190 			p = strchr(optarg,',');
    191 			if (p && *p != '\0') {
    192 				n = (int)strtoul(p+1, &q, 0);
    193 				if (*q == '\0'
    194 				    && n <= HOPCNT_INFINITY-1
    195 				    && n >= 1)
    196 					*p = '\0';
    197 			}
    198 			if (!getnet(optarg, &p_net, &p_mask)) {
    199 				msglog("bad network; \"-F %s\"",
    200 				       optarg);
    201 				break;
    202 			}
    203 			memset(&parm, 0, sizeof(parm));
    204 			parm.parm_net = p_net;
    205 			parm.parm_mask = p_mask;
    206 			parm.parm_d_metric = n;
    207 			p = check_parms(&parm);
    208 			if (p != 0)
    209 				msglog("bad -F: %s", p);
    210 			break;
    211 
    212 		case 'P':
    213 			/* handle arbitrary parameters.
    214 			 */
    215 			q = strdup(optarg);
    216 			p = parse_parms(q, 0);
    217 			if (p != 0)
    218 				msglog("%s in \"-P %s\"", p, optarg);
    219 			free(q);
    220 			break;
    221 
    222 		case 'v':
    223 			/* display version */
    224 			verbose++;
    225 			msglog("version 2.10");
    226 			break;
    227 
    228 		default:
    229 			goto usage;
    230 		}
    231 	}
    232 	argc -= optind;
    233 	argv += optind;
    234 
    235 	if (tracename == 0 && argc >= 1) {
    236 		tracename = *argv++;
    237 		argc--;
    238 	}
    239 	if (tracename != 0 && tracename[0] == '\0')
    240 		goto usage;
    241 	if (argc != 0) {
    242 usage:
    243 		logbad(0, "usage: routed [-sqdghmpAtv] [-T tracefile]"
    244 		       " [-F net[,metric]] [-P parms]");
    245 	}
    246 	if (geteuid() != 0) {
    247 		if (verbose)
    248 			exit(0);
    249 		logbad(0, "requires UID 0");
    250 	}
    251 
    252 	mib[0] = CTL_NET;
    253 	mib[1] = PF_INET;
    254 	mib[2] = IPPROTO_IP;
    255 	mib[3] = IPCTL_FORWARDING;
    256 	len = sizeof(ipforwarding);
    257 	if (sysctl(mib, 4, &ipforwarding, &len, 0, 0) < 0)
    258 		LOGERR("sysctl(IPCTL_FORWARDING)");
    259 
    260 	if (!ipforwarding) {
    261 		if (supplier)
    262 			msglog("-s incompatible with ipforwarding=0");
    263 		if (default_gateway) {
    264 			msglog("-g incompatible with ipforwarding=0");
    265 			default_gateway = 0;
    266 		}
    267 		supplier = 0;
    268 		supplier_set = 1;
    269 	}
    270 	if (default_gateway) {
    271 		if (supplier_set && !supplier) {
    272 			msglog("-g and -q incompatible");
    273 		} else {
    274 			supplier = 1;
    275 			supplier_set = 1;
    276 		}
    277 	}
    278 
    279 
    280 	signal(SIGALRM, sigalrm);
    281 	if (!background)
    282 		signal(SIGHUP, sigterm);    /* SIGHUP fatal during debugging */
    283 	signal(SIGTERM, sigterm);
    284 	signal(SIGINT, sigterm);
    285 	signal(SIGUSR1, sigtrace_on);
    286 	signal(SIGUSR2, sigtrace_off);
    287 
    288 	/* get into the background */
    289 #ifdef sgi
    290 	if (0 > _daemonize(background ? 0 : (_DF_NOCHDIR|_DF_NOFORK),
    291 			   STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO))
    292 		BADERR(0, "_daemonize()");
    293 #else
    294 	if (background && daemon(0, 1) < 0)
    295 		BADERR(0,"daemon()");
    296 #endif
    297 
    298 	mypid = getpid();
    299 	srandom((int)(clk.tv_sec ^ clk.tv_usec ^ mypid));
    300 
    301 	/* prepare socket connected to the kernel.
    302 	 */
    303 	rt_sock = cap_socket(AF_ROUTE, SOCK_RAW, 0);
    304 	if (rt_sock < 0)
    305 		BADERR(1,"rt_sock = socket()");
    306 	if (fcntl(rt_sock, F_SETFL, O_NONBLOCK) == -1)
    307 		logbad(1, "fcntl(rt_sock) O_NONBLOCK: %s", strerror(errno));
    308 	off = 0;
    309 	if (setsockopt(rt_sock, SOL_SOCKET,SO_USELOOPBACK,
    310 		       &off,sizeof(off)) < 0)
    311 		LOGERR("setsockopt(SO_USELOOPBACK,0)");
    312 
    313 	fix_select();
    314 
    315 
    316 	if (tracename != 0) {
    317 		strncpy(inittracename, tracename, sizeof(inittracename)-1);
    318 		set_tracefile(inittracename, "%s", -1);
    319 	} else {
    320 		tracelevel_msg("%s", -1);   /* turn on tracing to stdio */
    321 	}
    322 
    323 	bufinit();
    324 
    325 	/* initialize radix tree */
    326 	rtinit();
    327 
    328 	/* Pick a random part of the second for our output to minimize
    329 	 * collisions.
    330 	 *
    331 	 * Start broadcasting after hearing from other routers, and
    332 	 * at a random time so a bunch of systems do not get synchronized
    333 	 * after a power failure.
    334 	 */
    335 	intvl_random(&next_bcast, EPOCH+MIN_WAITTIME, EPOCH+SUPPLY_INTERVAL);
    336 	age_timer.tv_usec = next_bcast.tv_usec;
    337 	age_timer.tv_sec = EPOCH+MIN_WAITTIME;
    338 	rdisc_timer = next_bcast;
    339 	ifinit_timer.tv_usec = next_bcast.tv_usec;
    340 
    341 	/* Collect an initial view of the world by checking the interface
    342 	 * configuration and the kludge file.
    343 	 */
    344 	gwkludge();
    345 	ifinit();
    346 
    347 	/* Ask for routes */
    348 	rip_query();
    349 	rdisc_sol();
    350 
    351 	/* Now turn off stdio if not tracing */
    352 	if (new_tracelevel == 0)
    353 		trace_close(background);
    354 
    355 	/* Loop forever, listening and broadcasting.
    356 	 */
    357 	for (;;) {
    358 		prev_clk = clk;
    359 		gettimeofday(&clk, 0);
    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 housekeeping to
    364 			 * 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", dt);
    370 			epoch.tv_sec += dt;
    371 		}
    372 		timevalsub(&now, &clk, &epoch);
    373 		now_stale = now.tv_sec - STALE_TIME;
    374 		now_expire = now.tv_sec - EXPIRE_TIME;
    375 		now_garbage = now.tv_sec - GARBAGE_TIME;
    376 
    377 		/* deal with signals that should affect tracing */
    378 		set_tracelevel();
    379 
    380 		if (stopint != 0) {
    381 			rip_bcast(0);
    382 			rdisc_adv();
    383 			trace_off("exiting with signal %d", stopint);
    384 			exit(stopint | 128);
    385 		}
    386 
    387 		/* look for new or dead interfaces */
    388 		timevalsub(&wtime, &ifinit_timer, &now);
    389 		if (wtime.tv_sec <= 0) {
    390 			wtime.tv_sec = 0;
    391 			ifinit();
    392 			rip_query();
    393 			continue;
    394 		}
    395 
    396 		/* Check the kernel table occassionally for mysteriously
    397 		 * evaporated routes
    398 		 */
    399 		timevalsub(&t2, &flush_kern_timer, &now);
    400 		if (t2.tv_sec <= 0) {
    401 			flush_kern();
    402 			flush_kern_timer.tv_sec = (now.tv_sec
    403 						   + CHECK_QUIET_INTERVAL);
    404 			continue;
    405 		}
    406 		if (timercmp(&t2, &wtime, <))
    407 			wtime = t2;
    408 
    409 		/* If it is time, then broadcast our routes.
    410 		 */
    411 		if (supplier || advertise_mhome) {
    412 			timevalsub(&t2, &next_bcast, &now);
    413 			if (t2.tv_sec <= 0) {
    414 				/* Synchronize the aging and broadcast
    415 				 * timers to minimize awakenings
    416 				 */
    417 				age(0);
    418 
    419 				rip_bcast(0);
    420 
    421 				/* It is desirable to send routing updates
    422 				 * regularly.  So schedule the next update
    423 				 * 30 seconds after the previous one was
    424 				 * secheduled, instead of 30 seconds after
    425 				 * the previous update was finished.
    426 				 * Even if we just started after discovering
    427 				 * a 2nd interface or were otherwise delayed,
    428 				 * pick a 30-second aniversary of the
    429 				 * original broadcast time.
    430 				 */
    431 				n = 1 + (0-t2.tv_sec)/SUPPLY_INTERVAL;
    432 				next_bcast.tv_sec += n*SUPPLY_INTERVAL;
    433 
    434 				continue;
    435 			}
    436 
    437 			if (timercmp(&t2, &wtime, <))
    438 				wtime = t2;
    439 		}
    440 
    441 		/* If we need a flash update, either do it now or
    442 		 * set the delay to end when it is time.
    443 		 *
    444 		 * If we are within MIN_WAITTIME seconds of a full update,
    445 		 * do not bother.
    446 		 */
    447 		if (need_flash
    448 		    && supplier
    449 		    && no_flash.tv_sec+MIN_WAITTIME < next_bcast.tv_sec) {
    450 			/* accurate to the millisecond */
    451 			if (!timercmp(&no_flash, &now, >))
    452 				rip_bcast(1);
    453 			timevalsub(&t2, &no_flash, &now);
    454 			if (timercmp(&t2, &wtime, <))
    455 				wtime = t2;
    456 		}
    457 
    458 		/* trigger the main aging timer.
    459 		 */
    460 		timevalsub(&t2, &age_timer, &now);
    461 		if (t2.tv_sec <= 0) {
    462 			age(0);
    463 			continue;
    464 		}
    465 		if (timercmp(&t2, &wtime, <))
    466 			wtime = t2;
    467 
    468 		/* update the kernel routing table
    469 		 */
    470 		timevalsub(&t2, &need_kern, &now);
    471 		if (t2.tv_sec <= 0) {
    472 			age(0);
    473 			continue;
    474 		}
    475 		if (timercmp(&t2, &wtime, <))
    476 			wtime = t2;
    477 
    478 		/* take care of router discovery,
    479 		 * but do it in the correct the millisecond
    480 		 */
    481 		if (!timercmp(&rdisc_timer, &now, >)) {
    482 			rdisc_age(0);
    483 			continue;
    484 		}
    485 		timevalsub(&t2, &rdisc_timer, &now);
    486 		if (timercmp(&t2, &wtime, <))
    487 			wtime = t2;
    488 
    489 
    490 		/* wait for input or a timer to expire.
    491 		 */
    492 		trace_flush();
    493 		ibits = fdbits;
    494 		n = select(sock_max, &ibits, 0, 0, &wtime);
    495 		if (n <= 0) {
    496 			if (n < 0 && errno != EINTR && errno != EAGAIN)
    497 				BADERR(1,"select");
    498 			continue;
    499 		}
    500 
    501 		if (FD_ISSET(rt_sock, &ibits)) {
    502 			read_rt();
    503 			n--;
    504 		}
    505 		if (rdisc_sock >= 0 && FD_ISSET(rdisc_sock, &ibits)) {
    506 			read_d();
    507 			n--;
    508 		}
    509 		if (rip_sock >= 0 && FD_ISSET(rip_sock, &ibits)) {
    510 			read_rip(rip_sock, 0);
    511 			n--;
    512 		}
    513 
    514 		for (ifp = ifnet; n > 0 && 0 != ifp; ifp = ifp->int_next) {
    515 			if (ifp->int_rip_sock >= 0
    516 			    && FD_ISSET(ifp->int_rip_sock, &ibits)) {
    517 				read_rip(ifp->int_rip_sock, ifp);
    518 				n--;
    519 			}
    520 		}
    521 	}
    522 }
    523 
    524 
    525 /* ARGSUSED */
    526 void
    527 sigalrm(int s)
    528 {
    529 	/* Historically, SIGALRM would cause the daemon to check for
    530 	 * new and broken interfaces.
    531 	 */
    532 	ifinit_timer.tv_sec = now.tv_sec;
    533 	trace_act("SIGALRM");
    534 }
    535 
    536 
    537 /* watch for fatal signals */
    538 void
    539 sigterm(int sig)
    540 {
    541 	stopint = sig;
    542 	(void)signal(sig, SIG_DFL);	/* catch it only once */
    543 }
    544 
    545 
    546 void
    547 fix_select(void)
    548 {
    549 	struct interface *ifp;
    550 
    551 
    552 	FD_ZERO(&fdbits);
    553 	sock_max = 0;
    554 
    555 	FD_SET(rt_sock, &fdbits);
    556 	if (sock_max <= rt_sock)
    557 		sock_max = rt_sock+1;
    558 	if (rip_sock >= 0) {
    559 		FD_SET(rip_sock, &fdbits);
    560 		if (sock_max <= rip_sock)
    561 			sock_max = rip_sock+1;
    562 	}
    563 	for (ifp = ifnet; 0 != ifp; ifp = ifp->int_next) {
    564 		if (ifp->int_rip_sock >= 0) {
    565 			FD_SET(ifp->int_rip_sock, &fdbits);
    566 			if (sock_max <= ifp->int_rip_sock)
    567 				sock_max = ifp->int_rip_sock+1;
    568 		}
    569 	}
    570 	if (rdisc_sock >= 0) {
    571 		FD_SET(rdisc_sock, &fdbits);
    572 		if (sock_max <= rdisc_sock)
    573 			sock_max = rdisc_sock+1;
    574 	}
    575 }
    576 
    577 
    578 void
    579 fix_sock(int sock,
    580 	 char *name)
    581 {
    582 	int on;
    583 #define MIN_SOCKBUF (4*1024)
    584 	static int rbuf;
    585 
    586 	if (fcntl(sock, F_SETFL, O_NONBLOCK) == -1)
    587 		logbad(1, "fcntl(%s) O_NONBLOCK: %s",
    588 		       name, strerror(errno));
    589 	on = 1;
    590 	if (setsockopt(sock, SOL_SOCKET,SO_BROADCAST, &on,sizeof(on)) < 0)
    591 		msglog("setsockopt(%s,SO_BROADCAST): %s",
    592 		       name, strerror(errno));
    593 #ifdef USE_PASSIFNAME
    594 	on = 1;
    595 	if (setsockopt(sock, SOL_SOCKET, SO_PASSIFNAME, &on,sizeof(on)) < 0)
    596 		msglog("setsockopt(%s,SO_PASSIFNAME): %s",
    597 		       name, strerror(errno));
    598 #endif
    599 
    600 	if (rbuf >= MIN_SOCKBUF) {
    601 		if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
    602 			       &rbuf, sizeof(rbuf)) < 0)
    603 			msglog("setsockopt(%s,SO_RCVBUF=%d): %s",
    604 			       name, rbuf, strerror(errno));
    605 	} else {
    606 		for (rbuf = 60*1024; ; rbuf -= 4096) {
    607 			if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
    608 				       &rbuf, sizeof(rbuf)) == 0) {
    609 				trace_act("RCVBUF=%d", rbuf);
    610 				break;
    611 			}
    612 			if (rbuf < MIN_SOCKBUF) {
    613 				msglog("setsockopt(%s,SO_RCVBUF = %d): %s",
    614 				       name, rbuf, strerror(errno));
    615 				break;
    616 			}
    617 		}
    618 	}
    619 }
    620 
    621 
    622 /* get a rip socket
    623  */
    624 static int				/* <0 or file descriptor */
    625 get_rip_sock(naddr addr,
    626 	     int serious)		/* 1=failure to bind is serious */
    627 {
    628 	struct sockaddr_in sin;
    629 	unsigned char ttl;
    630 	int s;
    631 
    632 
    633 	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
    634 		BADERR(1,"rip_sock = socket()");
    635 
    636 	memset(&sin, 0, sizeof(sin));
    637 #ifdef _HAVE_SIN_LEN
    638 	sin.sin_len = sizeof(sin);
    639 #endif
    640 	sin.sin_family = AF_INET;
    641 	sin.sin_port = htons(RIP_PORT);
    642 	sin.sin_addr.s_addr = addr;
    643 	if (cap_bind(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
    644 		if (serious)
    645 			BADERR(errno != EADDRINUSE, "bind(rip_sock)");
    646 		return -1;
    647 	}
    648 	fix_sock(s,"rip_sock");
    649 
    650 	ttl = 1;
    651 	if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL,
    652 		       &ttl, sizeof(ttl)) < 0)
    653 		DBGERR(1,"rip_sock setsockopt(IP_MULTICAST_TTL)");
    654 
    655 	return s;
    656 }
    657 
    658 
    659 /* turn off main RIP socket */
    660 void
    661 rip_off(void)
    662 {
    663 	struct interface *ifp;
    664 	naddr addr;
    665 
    666 
    667 	if (rip_sock >= 0 && !mhome) {
    668 		trace_act("turn off RIP");
    669 
    670 		(void)close(rip_sock);
    671 		rip_sock = -1;
    672 
    673 		/* get non-broadcast sockets to listen to queries.
    674 		 */
    675 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
    676 			if (ifp->int_state & IS_REMOTE)
    677 				continue;
    678 			if (ifp->int_rip_sock < 0) {
    679 				addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
    680 					? ifp->int_dstaddr
    681 					: ifp->int_addr);
    682 				ifp->int_rip_sock = get_rip_sock(addr, 0);
    683 			}
    684 		}
    685 
    686 		fix_select();
    687 
    688 		age(0);
    689 	}
    690 }
    691 
    692 
    693 /* turn on RIP multicast input via an interface
    694  */
    695 static void
    696 rip_mcast_on(struct interface *ifp)
    697 {
    698 	struct ip_mreq m;
    699 
    700 	if (!IS_RIP_IN_OFF(ifp->int_state)
    701 	    && (ifp->int_if_flags & IFF_MULTICAST)
    702 #ifdef MCAST_PPP_BUG
    703 	    && !(ifp->int_if_flags & IFF_POINTOPOINT)
    704 #endif
    705 	    && !(ifp->int_state & IS_ALIAS)) {
    706 		m.imr_multiaddr.s_addr = htonl(INADDR_RIP_GROUP);
    707 		m.imr_interface.s_addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
    708 					  ? ifp->int_dstaddr
    709 					  : ifp->int_addr);
    710 		if (setsockopt(rip_sock,IPPROTO_IP, IP_ADD_MEMBERSHIP,
    711 			       &m, sizeof(m)) < 0)
    712 			LOGERR("setsockopt(IP_ADD_MEMBERSHIP RIP)");
    713 	}
    714 }
    715 
    716 
    717 /* Prepare socket used for RIP.
    718  */
    719 void
    720 rip_on(struct interface *ifp)
    721 {
    722 	/* If the main RIP socket is already alive, only start receiving
    723 	 * multicasts for this interface.
    724 	 */
    725 	if (rip_sock >= 0) {
    726 		if (ifp != 0)
    727 			rip_mcast_on(ifp);
    728 		return;
    729 	}
    730 
    731 	/* If the main RIP socket is off and it makes sense to turn it on,
    732 	 * then turn it on for all of the interfaces.
    733 	 * It makes sense if either router discovery is off, or if
    734 	 * router discover is on and at most one interface is doing RIP.
    735 	 */
    736 	if (rip_interfaces > 0 && (!rdisc_ok || rip_interfaces > 1)) {
    737 		trace_act("turn on RIP");
    738 
    739 		/* Close all of the query sockets so that we can open
    740 		 * the main socket.  SO_REUSEPORT is not a solution,
    741 		 * since that would let two daemons bind to the broadcast
    742 		 * socket.
    743 		 */
    744 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
    745 			if (ifp->int_rip_sock >= 0) {
    746 				(void)close(ifp->int_rip_sock);
    747 				ifp->int_rip_sock = -1;
    748 			}
    749 		}
    750 
    751 		rip_sock = get_rip_sock(INADDR_ANY, 1);
    752 		rip_sock_mcast = 0;
    753 
    754 		/* Do not advertise anything until we have heard something
    755 		 */
    756 		if (next_bcast.tv_sec < now.tv_sec+MIN_WAITTIME)
    757 			next_bcast.tv_sec = now.tv_sec+MIN_WAITTIME;
    758 
    759 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
    760 			ifp->int_query_time = NEVER;
    761 			rip_mcast_on(ifp);
    762 		}
    763 		ifinit_timer.tv_sec = now.tv_sec;
    764 
    765 	} else if (ifp != 0
    766 		   && !(ifp->int_state & IS_REMOTE)
    767 		   && ifp->int_rip_sock < 0) {
    768 		/* RIP is off, so ensure there are sockets on which
    769 		 * to listen for queries.
    770 		 */
    771 		ifp->int_rip_sock = get_rip_sock(ifp->int_addr, 0);
    772 	}
    773 
    774 	fix_select();
    775 }
    776 
    777 
    778 /* die if malloc(3) fails
    779  */
    780 void *
    781 rtmalloc(size_t size,
    782 	 char *msg)
    783 {
    784 	void *p = malloc(size);
    785 	if (p == 0)
    786 		logbad(1,"malloc(%d) failed in %s", size, msg);
    787 	return p;
    788 }
    789 
    790 
    791 /* get a random instant in an interval
    792  */
    793 void
    794 intvl_random(struct timeval *tp,	/* put value here */
    795 	     u_long lo,			/* value is after this second */
    796 	     u_long hi)			/* and before this */
    797 {
    798 	tp->tv_sec = (time_t)(hi == lo
    799 			      ? lo
    800 			      : (lo + random() % ((hi - lo))));
    801 	tp->tv_usec = random() % 1000000;
    802 }
    803 
    804 
    805 void
    806 timevaladd(struct timeval *t1,
    807 	   struct timeval *t2)
    808 {
    809 
    810 	t1->tv_sec += t2->tv_sec;
    811 	if ((t1->tv_usec += t2->tv_usec) > 1000000) {
    812 		t1->tv_sec++;
    813 		t1->tv_usec -= 1000000;
    814 	}
    815 }
    816 
    817 
    818 /* t1 = t2 - t3
    819  */
    820 static void
    821 timevalsub(struct timeval *t1,
    822 	   struct timeval *t2,
    823 	   struct timeval *t3)
    824 {
    825 	t1->tv_sec = t2->tv_sec - t3->tv_sec;
    826 	if ((t1->tv_usec = t2->tv_usec - t3->tv_usec) < 0) {
    827 		t1->tv_sec--;
    828 		t1->tv_usec += 1000000;
    829 	}
    830 }
    831 
    832 
    833 /* put a message into the system log
    834  */
    835 void
    836 msglog(char *p, ...)
    837 {
    838 	va_list args;
    839 
    840 	trace_flush();
    841 
    842 	va_start(args, p);
    843 	vsyslog(LOG_ERR, p, args);
    844 
    845 	if (ftrace != 0) {
    846 		if (ftrace == stdout)
    847 			(void)fputs("routed: ", ftrace);
    848 		(void)vfprintf(ftrace, p, args);
    849 		(void)fputc('\n', ftrace);
    850 	}
    851 }
    852 
    853 
    854 /* Put a message about a bad system into the system log if
    855  * we have not complained about it recently.
    856  *
    857  * It is desirable to complain about all bad systems, but not too often.
    858  * In the worst case, it is not practical to keep track of all bad systems.
    859  * For example, there can be many systems with the wrong password.
    860  */
    861 void
    862 msglim(struct msg_limit *lim, naddr addr, char *p, ...)
    863 {
    864 	va_list args;
    865 	int i;
    866 	struct msg_sub *ms1, *ms;
    867 	char *p1;
    868 
    869 	va_start(args, p);
    870 
    871 	/* look for the oldest slot in the table
    872 	 * or the slot for the bad router.
    873 	 */
    874 	ms = ms1 = lim->subs;
    875 	for (i = MSG_SUBJECT_N; ; i--, ms1++) {
    876 		if (i == 0) {
    877 			/* Reuse a slot at most once every 10 minutes.
    878 			 */
    879 			if (lim->reuse > now.tv_sec) {
    880 				ms = 0;
    881 			} else {
    882 				ms = ms1;
    883 				lim->reuse = now.tv_sec + 10*60;
    884 			}
    885 			break;
    886 		}
    887 		if (ms->addr == addr) {
    888 			/* Repeat a complaint about a given system at
    889 			 * most once an hour.
    890 			 */
    891 			if (ms->until > now.tv_sec)
    892 				ms = 0;
    893 			break;
    894 		}
    895 		if (ms->until < ms1->until)
    896 			ms = ms1;
    897 	}
    898 	if (ms != 0) {
    899 		ms->addr = addr;
    900 		ms->until = now.tv_sec + 60*60;	/* 60 minutes */
    901 
    902 		trace_flush();
    903 		for (p1 = p; *p1 == ' '; p1++)
    904 			continue;
    905 		vsyslog(LOG_ERR, p1, args);
    906 	}
    907 
    908 	/* always display the message if tracing */
    909 	if (ftrace != 0) {
    910 		(void)vfprintf(ftrace, p, args);
    911 		(void)fputc('\n', ftrace);
    912 	}
    913 }
    914 
    915 
    916 void
    917 logbad(int dump, char *p, ...)
    918 {
    919 	va_list args;
    920 
    921 	trace_flush();
    922 
    923 	va_start(args, p);
    924 	vsyslog(LOG_ERR, p, args);
    925 
    926 	(void)fputs("routed: ", stderr);
    927 	(void)vfprintf(stderr, p, args);
    928 	(void)fputs("; giving up\n",stderr);
    929 	(void)fflush(stderr);
    930 
    931 	if (dump)
    932 		abort();
    933 	exit(1);
    934 }
    935