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main.c revision 1.32
      1 /*	$NetBSD: main.c,v 1.32 2003/04/21 08:54:42 itojun 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 #ifdef sgi
     39 #include "math.h"
     40 #endif
     41 #include <signal.h>
     42 #include <fcntl.h>
     43 #include <sys/file.h>
     44 
     45 __COPYRIGHT("@(#) Copyright (c) 1983, 1988, 1993\n"
     46 	    "The Regents of the University of California."
     47 	    "  All rights reserved.\n");
     48 #ifdef __NetBSD__
     49 __RCSID("$NetBSD: main.c,v 1.32 2003/04/21 08:54:42 itojun Exp $");
     50 #elif defined(__FreeBSD__)
     51 __RCSID("$FreeBSD$");
     52 #else
     53 __RCSID("Revision: 2.27 ");
     54 #ident "Revision: 2.27 "
     55 #endif
     56 
     57 #if defined(__NetBSD__)
     58 #include <util.h>
     59 #endif
     60 
     61 pid_t	mypid;
     62 
     63 naddr	myaddr;				/* system address */
     64 char	myname[MAXHOSTNAMELEN+1];
     65 
     66 int	verbose;
     67 
     68 int	supplier;			/* supply or broadcast updates */
     69 int	supplier_set;
     70 int	ipforwarding = 1;		/* kernel forwarding on */
     71 
     72 int	default_gateway;		/* 1=advertise default */
     73 int	background = 1;
     74 int	ridhosts;			/* 1=reduce host routes */
     75 int	mhome;				/* 1=want multi-homed host route */
     76 int	advertise_mhome;		/* 1=must continue advertising it */
     77 int	auth_ok = 1;			/* 1=ignore auth if we do not care */
     78 
     79 struct timeval epoch;			/* when started */
     80 struct timeval clk, prev_clk;
     81 static int usec_fudge;
     82 struct timeval now;			/* current idea of time */
     83 time_t	now_stale;
     84 time_t	now_expire;
     85 time_t	now_garbage;
     86 
     87 struct timeval next_bcast;		/* next general broadcast */
     88 struct timeval no_flash = {		/* inhibit flash update */
     89 	EPOCH+SUPPLY_INTERVAL, 0
     90 };
     91 
     92 struct timeval flush_kern_timer;
     93 
     94 fd_set	fdbits;
     95 int	sock_max;
     96 int	rip_sock = -1;			/* RIP socket */
     97 struct interface *rip_sock_mcast;	/* current multicast interface */
     98 int	rt_sock;			/* routing socket */
     99 int	rt_sock_seqno;
    100 
    101 
    102 static  int get_rip_sock(naddr, int);
    103 static void timevalsub(struct timeval *, struct timeval *, struct timeval *);
    104 
    105 int
    106 main(int argc,
    107      char *argv[])
    108 {
    109 	int n, mib[4], off;
    110 	size_t len;
    111 	char *p, *q;
    112 	const char *cp;
    113 	struct timeval wtime, t2;
    114 	time_t dt;
    115 	fd_set ibits;
    116 	naddr p_net, p_mask;
    117 	struct interface *ifp;
    118 	struct parm parm;
    119 	char *tracename = 0;
    120 
    121 
    122 	/* Some shells are badly broken and send SIGHUP to backgrounded
    123 	 * processes.
    124 	 */
    125 	signal(SIGHUP, SIG_IGN);
    126 
    127 	openlog("routed", LOG_PID, LOG_DAEMON);
    128 	ftrace = stdout;
    129 
    130 	gettimeofday(&clk, 0);
    131 	prev_clk = clk;
    132 	epoch = clk;
    133 	epoch.tv_sec -= EPOCH;
    134 	now.tv_sec = EPOCH;
    135 	now_stale = EPOCH - STALE_TIME;
    136 	now_expire = EPOCH - EXPIRE_TIME;
    137 	now_garbage = EPOCH - GARBAGE_TIME;
    138 	wtime.tv_sec = 0;
    139 
    140 	(void)gethostname(myname, sizeof(myname) - 1);
    141 	(void)gethost(myname, &myaddr);
    142 
    143 	while ((n = getopt(argc, argv, "sqdghmpAtvT:F:P:")) != -1) {
    144 		switch (n) {
    145 		case 's':
    146 			supplier = 1;
    147 			supplier_set = 1;
    148 			break;
    149 
    150 		case 'q':
    151 			supplier = 0;
    152 			supplier_set = 1;
    153 			break;
    154 
    155 		case 'd':
    156 			background = 0;
    157 			break;
    158 
    159 		case 'g':
    160 			memset(&parm, 0, sizeof(parm));
    161 			parm.parm_d_metric = 1;
    162 			cp = check_parms(&parm);
    163 			if (cp != 0)
    164 				msglog("bad -g: %s", cp);
    165 			else
    166 				default_gateway = 1;
    167 			break;
    168 
    169 		case 'h':		/* suppress extra host routes */
    170 			ridhosts = 1;
    171 			break;
    172 
    173 		case 'm':		/* advertise host route */
    174 			mhome = 1;	/* on multi-homed hosts */
    175 			break;
    176 
    177 		case 'A':
    178 			/* Ignore authentication if we do not care.
    179 			 * Crazy as it is, that is what RFC 1723 requires.
    180 			 */
    181 			auth_ok = 0;
    182 			break;
    183 
    184 		case 't':
    185 			new_tracelevel++;
    186 			break;
    187 
    188 		case 'T':
    189 			tracename = optarg;
    190 			break;
    191 
    192 		case 'F':		/* minimal routes for SLIP */
    193 			n = FAKE_METRIC;
    194 			p = strchr(optarg,',');
    195 			if (p && *p != '\0') {
    196 				n = (int)strtoul(p+1, &q, 0);
    197 				if (*q == '\0'
    198 				    && n <= HOPCNT_INFINITY-1
    199 				    && n >= 1)
    200 					*p = '\0';
    201 			}
    202 			if (!getnet(optarg, &p_net, &p_mask)) {
    203 				msglog("bad network; \"-F %s\"",
    204 				       optarg);
    205 				break;
    206 			}
    207 			memset(&parm, 0, sizeof(parm));
    208 			parm.parm_net = p_net;
    209 			parm.parm_mask = p_mask;
    210 			parm.parm_d_metric = n;
    211 			cp = check_parms(&parm);
    212 			if (cp != 0)
    213 				msglog("bad -F: %s", cp);
    214 			break;
    215 
    216 		case 'P':
    217 			/* handle arbitrary parameters.
    218 			 */
    219 			q = strdup(optarg);
    220 			cp = parse_parms(q, 0);
    221 			if (cp != 0)
    222 				msglog("%s in \"-P %s\"", cp, optarg);
    223 			free(q);
    224 			break;
    225 
    226 		case 'v':
    227 			/* display version */
    228 			verbose++;
    229 			msglog("version 2.25");
    230 			break;
    231 
    232 		default:
    233 			goto usage;
    234 		}
    235 	}
    236 	argc -= optind;
    237 	argv += optind;
    238 
    239 	if (tracename == 0 && argc >= 1) {
    240 		tracename = *argv++;
    241 		argc--;
    242 	}
    243 	if (tracename != 0 && tracename[0] == '\0')
    244 		goto usage;
    245 	if (argc != 0) {
    246 usage:
    247 		logbad(0, "usage: routed [-sqdghmpAtv] [-T tracefile]"
    248 		       " [-F net[,metric]] [-P parms]");
    249 	}
    250 	if (geteuid() != 0) {
    251 		if (verbose)
    252 			exit(0);
    253 		logbad(0, "requires UID 0");
    254 	}
    255 
    256 	mib[0] = CTL_NET;
    257 	mib[1] = PF_INET;
    258 	mib[2] = IPPROTO_IP;
    259 	mib[3] = IPCTL_FORWARDING;
    260 	len = sizeof(ipforwarding);
    261 	if (sysctl(mib, 4, &ipforwarding, &len, 0, 0) < 0)
    262 		LOGERR("sysctl(IPCTL_FORWARDING)");
    263 
    264 	if (!ipforwarding) {
    265 		if (supplier)
    266 			msglog("-s incompatible with ipforwarding=0");
    267 		if (default_gateway) {
    268 			msglog("-g incompatible with ipforwarding=0");
    269 			default_gateway = 0;
    270 		}
    271 		supplier = 0;
    272 		supplier_set = 1;
    273 	}
    274 	if (default_gateway) {
    275 		if (supplier_set && !supplier) {
    276 			msglog("-g and -q incompatible");
    277 		} else {
    278 			supplier = 1;
    279 			supplier_set = 1;
    280 		}
    281 	}
    282 
    283 
    284 	signal(SIGALRM, sigalrm);
    285 	if (!background)
    286 		signal(SIGHUP, sigterm);    /* SIGHUP fatal during debugging */
    287 	signal(SIGTERM, sigterm);
    288 	signal(SIGINT, sigterm);
    289 	signal(SIGUSR1, sigtrace_on);
    290 	signal(SIGUSR2, sigtrace_off);
    291 
    292 	/* get into the background */
    293 #ifdef sgi
    294 	if (0 > _daemonize(background ? 0 : (_DF_NOCHDIR|_DF_NOFORK),
    295 			   STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO))
    296 		BADERR(0, "_daemonize()");
    297 #else
    298 	if (background && daemon(0, 1) < 0)
    299 		BADERR(0,"daemon()");
    300 #endif
    301 
    302 #if defined(__NetBSD__)
    303 	pidfile(NULL);
    304 #endif
    305 	mypid = getpid();
    306 	srandom((int)(clk.tv_sec ^ clk.tv_usec ^ mypid));
    307 
    308 	/* prepare socket connected to the kernel.
    309 	 */
    310 	rt_sock = socket(AF_ROUTE, SOCK_RAW, 0);
    311 	if (rt_sock < 0)
    312 		BADERR(1,"rt_sock = socket()");
    313 	if (fcntl(rt_sock, F_SETFL, O_NONBLOCK) == -1)
    314 		logbad(1, "fcntl(rt_sock) O_NONBLOCK: %s", strerror(errno));
    315 	off = 0;
    316 	if (setsockopt(rt_sock, SOL_SOCKET,SO_USELOOPBACK,
    317 		       &off,sizeof(off)) < 0)
    318 		LOGERR("setsockopt(SO_USELOOPBACK,0)");
    319 
    320 	fix_select();
    321 
    322 
    323 	if (tracename != 0) {
    324 		strlcpy(inittracename, tracename, sizeof(inittracename));
    325 		set_tracefile(inittracename, "%s", -1);
    326 	} else {
    327 		tracelevel_msg("%s", -1);   /* turn on tracing to stdio */
    328 	}
    329 
    330 	bufinit();
    331 
    332 	/* initialize radix tree */
    333 	rtinit();
    334 
    335 	/* Pick a random part of the second for our output to minimize
    336 	 * collisions.
    337 	 *
    338 	 * Start broadcasting after hearing from other routers, and
    339 	 * at a random time so a bunch of systems do not get synchronized
    340 	 * after a power failure.
    341 	 */
    342 	intvl_random(&next_bcast, EPOCH+MIN_WAITTIME, EPOCH+SUPPLY_INTERVAL);
    343 	age_timer.tv_usec = next_bcast.tv_usec;
    344 	age_timer.tv_sec = EPOCH+MIN_WAITTIME;
    345 	rdisc_timer = next_bcast;
    346 	ifinit_timer.tv_usec = next_bcast.tv_usec;
    347 
    348 	/* Collect an initial view of the world by checking the interface
    349 	 * configuration and the kludge file.
    350 	 */
    351 	gwkludge();
    352 	ifinit();
    353 
    354 	/* Ask for routes */
    355 	rip_query();
    356 	rdisc_sol();
    357 
    358 	/* Now turn off stdio if not tracing */
    359 	if (new_tracelevel == 0)
    360 		trace_close(background);
    361 
    362 	/* Loop forever, listening and broadcasting.
    363 	 */
    364 	for (;;) {
    365 		prev_clk = clk;
    366 		gettimeofday(&clk, 0);
    367 		if (prev_clk.tv_sec == clk.tv_sec
    368 		    && prev_clk.tv_usec == clk.tv_usec+usec_fudge) {
    369 			/* Much of `routed` depends on time always advancing.
    370 			 * On systems that do not guarantee that gettimeofday()
    371 			 * produces unique timestamps even if called within
    372 			 * a single tick, use trickery like that in classic
    373 			 * BSD kernels.
    374 			 */
    375 			clk.tv_usec += ++usec_fudge;
    376 
    377 		} else {
    378 			usec_fudge = 0;
    379 
    380 			timevalsub(&t2, &clk, &prev_clk);
    381 			if (t2.tv_sec < 0
    382 			    || t2.tv_sec > wtime.tv_sec + 5) {
    383 				/* Deal with time changes before other
    384 				 * housekeeping to keep everything straight.
    385 				 */
    386 				dt = t2.tv_sec;
    387 				if (dt > 0)
    388 					dt -= wtime.tv_sec;
    389 				trace_act("time changed by %d sec", (int)dt);
    390 				epoch.tv_sec += dt;
    391 			}
    392 		}
    393 		timevalsub(&now, &clk, &epoch);
    394 		now_stale = now.tv_sec - STALE_TIME;
    395 		now_expire = now.tv_sec - EXPIRE_TIME;
    396 		now_garbage = now.tv_sec - GARBAGE_TIME;
    397 
    398 		/* deal with signals that should affect tracing */
    399 		set_tracelevel();
    400 
    401 		if (stopint != 0) {
    402 			rip_bcast(0);
    403 			rdisc_adv();
    404 			trace_off("exiting with signal %d", stopint);
    405 			exit(stopint | 128);
    406 		}
    407 
    408 		/* look for new or dead interfaces */
    409 		timevalsub(&wtime, &ifinit_timer, &now);
    410 		if (wtime.tv_sec <= 0) {
    411 			wtime.tv_sec = 0;
    412 			ifinit();
    413 			rip_query();
    414 			continue;
    415 		}
    416 
    417 		/* Check the kernel table occassionally for mysteriously
    418 		 * evaporated routes
    419 		 */
    420 		timevalsub(&t2, &flush_kern_timer, &now);
    421 		if (t2.tv_sec <= 0) {
    422 			flush_kern();
    423 			flush_kern_timer.tv_sec = (now.tv_sec
    424 						   + CHECK_QUIET_INTERVAL);
    425 			continue;
    426 		}
    427 		if (timercmp(&t2, &wtime, <))
    428 			wtime = t2;
    429 
    430 		/* If it is time, then broadcast our routes.
    431 		 */
    432 		if (supplier || advertise_mhome) {
    433 			timevalsub(&t2, &next_bcast, &now);
    434 			if (t2.tv_sec <= 0) {
    435 				/* Synchronize the aging and broadcast
    436 				 * timers to minimize awakenings
    437 				 */
    438 				age(0);
    439 
    440 				rip_bcast(0);
    441 
    442 				/* It is desirable to send routing updates
    443 				 * regularly.  So schedule the next update
    444 				 * 30 seconds after the previous one was
    445 				 * scheduled, instead of 30 seconds after
    446 				 * the previous update was finished.
    447 				 * Even if we just started after discovering
    448 				 * a 2nd interface or were otherwise delayed,
    449 				 * pick a 30-second aniversary of the
    450 				 * original broadcast time.
    451 				 */
    452 				n = 1 + (0-t2.tv_sec)/SUPPLY_INTERVAL;
    453 				next_bcast.tv_sec += n*SUPPLY_INTERVAL;
    454 
    455 				continue;
    456 			}
    457 
    458 			if (timercmp(&t2, &wtime, <))
    459 				wtime = t2;
    460 		}
    461 
    462 		/* If we need a flash update, either do it now or
    463 		 * set the delay to end when it is time.
    464 		 *
    465 		 * If we are within MIN_WAITTIME seconds of a full update,
    466 		 * do not bother.
    467 		 */
    468 		if (need_flash
    469 		    && supplier
    470 		    && no_flash.tv_sec+MIN_WAITTIME < next_bcast.tv_sec) {
    471 			/* accurate to the millisecond */
    472 			if (!timercmp(&no_flash, &now, >))
    473 				rip_bcast(1);
    474 			timevalsub(&t2, &no_flash, &now);
    475 			if (timercmp(&t2, &wtime, <))
    476 				wtime = t2;
    477 		}
    478 
    479 		/* trigger the main aging timer.
    480 		 */
    481 		timevalsub(&t2, &age_timer, &now);
    482 		if (t2.tv_sec <= 0) {
    483 			age(0);
    484 			continue;
    485 		}
    486 		if (timercmp(&t2, &wtime, <))
    487 			wtime = t2;
    488 
    489 		/* update the kernel routing table
    490 		 */
    491 		timevalsub(&t2, &need_kern, &now);
    492 		if (t2.tv_sec <= 0) {
    493 			age(0);
    494 			continue;
    495 		}
    496 		if (timercmp(&t2, &wtime, <))
    497 			wtime = t2;
    498 
    499 		/* take care of router discovery,
    500 		 * but do it in the correct the millisecond
    501 		 */
    502 		if (!timercmp(&rdisc_timer, &now, >)) {
    503 			rdisc_age(0);
    504 			continue;
    505 		}
    506 		timevalsub(&t2, &rdisc_timer, &now);
    507 		if (timercmp(&t2, &wtime, <))
    508 			wtime = t2;
    509 
    510 
    511 		/* wait for input or a timer to expire.
    512 		 */
    513 		trace_flush();
    514 		ibits = fdbits;
    515 		n = select(sock_max, &ibits, 0, 0, &wtime);
    516 		if (n <= 0) {
    517 			if (n < 0 && errno != EINTR && errno != EAGAIN)
    518 				BADERR(1,"select");
    519 			continue;
    520 		}
    521 
    522 		if (FD_ISSET(rt_sock, &ibits)) {
    523 			read_rt();
    524 			n--;
    525 		}
    526 		if (rdisc_sock >= 0 && FD_ISSET(rdisc_sock, &ibits)) {
    527 			read_d();
    528 			n--;
    529 		}
    530 		if (rip_sock >= 0 && FD_ISSET(rip_sock, &ibits)) {
    531 			read_rip(rip_sock, 0);
    532 			n--;
    533 		}
    534 
    535 		for (ifp = ifnet; n > 0 && 0 != ifp; ifp = ifp->int_next) {
    536 			if (ifp->int_rip_sock >= 0
    537 			    && FD_ISSET(ifp->int_rip_sock, &ibits)) {
    538 				read_rip(ifp->int_rip_sock, ifp);
    539 				n--;
    540 			}
    541 		}
    542 	}
    543 }
    544 
    545 
    546 /* ARGSUSED */
    547 void
    548 sigalrm(int s UNUSED)
    549 {
    550 	/* Historically, SIGALRM would cause the daemon to check for
    551 	 * new and broken interfaces.
    552 	 */
    553 	ifinit_timer.tv_sec = now.tv_sec;
    554 	trace_act("SIGALRM");
    555 }
    556 
    557 
    558 /* watch for fatal signals */
    559 void
    560 sigterm(int sig)
    561 {
    562 	stopint = sig;
    563 	(void)signal(sig, SIG_DFL);	/* catch it only once */
    564 }
    565 
    566 
    567 void
    568 fix_select(void)
    569 {
    570 	struct interface *ifp;
    571 
    572 
    573 	FD_ZERO(&fdbits);
    574 	sock_max = 0;
    575 
    576 	FD_SET(rt_sock, &fdbits);
    577 	if (sock_max <= rt_sock)
    578 		sock_max = rt_sock+1;
    579 	if (rip_sock >= 0) {
    580 		FD_SET(rip_sock, &fdbits);
    581 		if (sock_max <= rip_sock)
    582 			sock_max = rip_sock+1;
    583 	}
    584 	for (ifp = ifnet; 0 != ifp; ifp = ifp->int_next) {
    585 		if (ifp->int_rip_sock >= 0) {
    586 			FD_SET(ifp->int_rip_sock, &fdbits);
    587 			if (sock_max <= ifp->int_rip_sock)
    588 				sock_max = ifp->int_rip_sock+1;
    589 		}
    590 	}
    591 	if (rdisc_sock >= 0) {
    592 		FD_SET(rdisc_sock, &fdbits);
    593 		if (sock_max <= rdisc_sock)
    594 			sock_max = rdisc_sock+1;
    595 	}
    596 }
    597 
    598 
    599 void
    600 fix_sock(int sock,
    601 	 const char *name)
    602 {
    603 	int on;
    604 #define MIN_SOCKBUF (4*1024)
    605 	static int rbuf;
    606 
    607 	if (fcntl(sock, F_SETFL, O_NONBLOCK) == -1)
    608 		logbad(1, "fcntl(%s) O_NONBLOCK: %s",
    609 		       name, strerror(errno));
    610 	on = 1;
    611 	if (setsockopt(sock, SOL_SOCKET,SO_BROADCAST, &on,sizeof(on)) < 0)
    612 		msglog("setsockopt(%s,SO_BROADCAST): %s",
    613 		       name, strerror(errno));
    614 #ifdef USE_PASSIFNAME
    615 	on = 1;
    616 	if (setsockopt(sock, SOL_SOCKET, SO_PASSIFNAME, &on,sizeof(on)) < 0)
    617 		msglog("setsockopt(%s,SO_PASSIFNAME): %s",
    618 		       name, strerror(errno));
    619 #endif
    620 
    621 	if (rbuf >= MIN_SOCKBUF) {
    622 		if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
    623 			       &rbuf, sizeof(rbuf)) < 0)
    624 			msglog("setsockopt(%s,SO_RCVBUF=%d): %s",
    625 			       name, rbuf, strerror(errno));
    626 	} else {
    627 		for (rbuf = 60*1024; ; rbuf -= 4096) {
    628 			if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
    629 				       &rbuf, sizeof(rbuf)) == 0) {
    630 				trace_act("RCVBUF=%d", rbuf);
    631 				break;
    632 			}
    633 			if (rbuf < MIN_SOCKBUF) {
    634 				msglog("setsockopt(%s,SO_RCVBUF = %d): %s",
    635 				       name, rbuf, strerror(errno));
    636 				break;
    637 			}
    638 		}
    639 	}
    640 }
    641 
    642 
    643 /* get a rip socket
    644  */
    645 static int				/* <0 or file descriptor */
    646 get_rip_sock(naddr addr,
    647 	     int serious)		/* 1=failure to bind is serious */
    648 {
    649 	struct sockaddr_in rsin;
    650 	unsigned char ttl;
    651 	int s;
    652 
    653 
    654 	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
    655 		BADERR(1,"rip_sock = socket()");
    656 
    657 	memset(&rsin, 0, sizeof(rsin));
    658 #ifdef _HAVE_SIN_LEN
    659 	rsin.sin_len = sizeof(rsin);
    660 #endif
    661 	rsin.sin_family = AF_INET;
    662 	rsin.sin_port = htons(RIP_PORT);
    663 	rsin.sin_addr.s_addr = addr;
    664 	if (bind(s, (struct sockaddr *)&rsin, sizeof(rsin)) < 0) {
    665 		if (serious)
    666 			BADERR(errno != EADDRINUSE, "bind(rip_sock)");
    667 		return -1;
    668 	}
    669 	fix_sock(s,"rip_sock");
    670 
    671 	ttl = 1;
    672 	if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL,
    673 		       &ttl, sizeof(ttl)) < 0)
    674 		DBGERR(1,"rip_sock setsockopt(IP_MULTICAST_TTL)");
    675 
    676 	return s;
    677 }
    678 
    679 
    680 /* turn off main RIP socket */
    681 void
    682 rip_off(void)
    683 {
    684 	struct interface *ifp;
    685 	naddr addr;
    686 
    687 
    688 	if (rip_sock >= 0 && !mhome) {
    689 		trace_act("turn off RIP");
    690 
    691 		(void)close(rip_sock);
    692 		rip_sock = -1;
    693 
    694 		/* get non-broadcast sockets to listen to queries.
    695 		 */
    696 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
    697 			if (ifp->int_state & IS_REMOTE)
    698 				continue;
    699 			if (ifp->int_rip_sock < 0) {
    700 				addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
    701 					? ifp->int_dstaddr
    702 					: ifp->int_addr);
    703 				ifp->int_rip_sock = get_rip_sock(addr, 0);
    704 			}
    705 		}
    706 
    707 		fix_select();
    708 
    709 		age(0);
    710 	}
    711 }
    712 
    713 
    714 /* turn on RIP multicast input via an interface
    715  */
    716 static void
    717 rip_mcast_on(struct interface *ifp)
    718 {
    719 	struct ip_mreq m;
    720 
    721 	if (!IS_RIP_IN_OFF(ifp->int_state)
    722 	    && (ifp->int_if_flags & IFF_MULTICAST)
    723 #ifdef MCAST_PPP_BUG
    724 	    && !(ifp->int_if_flags & IFF_POINTOPOINT)
    725 #endif
    726 	    && !(ifp->int_state & IS_ALIAS)) {
    727 		m.imr_multiaddr.s_addr = htonl(INADDR_RIP_GROUP);
    728 #ifdef MCAST_IFINDEX
    729 		m.imr_interface.s_addr = htonl(ifp->int_index);
    730 #else
    731 		m.imr_interface.s_addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
    732 					  ? ifp->int_dstaddr
    733 					  : ifp->int_addr);
    734 #endif
    735 		if (setsockopt(rip_sock,IPPROTO_IP, IP_ADD_MEMBERSHIP,
    736 			       &m, sizeof(m)) < 0)
    737 			LOGERR("setsockopt(IP_ADD_MEMBERSHIP RIP)");
    738 	}
    739 }
    740 
    741 
    742 /* Prepare socket used for RIP.
    743  */
    744 void
    745 rip_on(struct interface *ifp)
    746 {
    747 	/* If the main RIP socket is already alive, only start receiving
    748 	 * multicasts for this interface.
    749 	 */
    750 	if (rip_sock >= 0) {
    751 		if (ifp != 0)
    752 			rip_mcast_on(ifp);
    753 		return;
    754 	}
    755 
    756 	/* If the main RIP socket is off and it makes sense to turn it on,
    757 	 * then turn it on for all of the interfaces.
    758 	 * It makes sense if either router discovery is off, or if
    759 	 * router discover is on and at most one interface is doing RIP.
    760 	 */
    761 	if (rip_interfaces > 0 && (!rdisc_ok || rip_interfaces > 1)) {
    762 		trace_act("turn on RIP");
    763 
    764 		/* Close all of the query sockets so that we can open
    765 		 * the main socket.  SO_REUSEPORT is not a solution,
    766 		 * since that would let two daemons bind to the broadcast
    767 		 * socket.
    768 		 */
    769 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
    770 			if (ifp->int_rip_sock >= 0) {
    771 				(void)close(ifp->int_rip_sock);
    772 				ifp->int_rip_sock = -1;
    773 			}
    774 		}
    775 
    776 		rip_sock = get_rip_sock(INADDR_ANY, 1);
    777 		rip_sock_mcast = 0;
    778 
    779 		/* Do not advertise anything until we have heard something
    780 		 */
    781 		if (next_bcast.tv_sec < now.tv_sec+MIN_WAITTIME)
    782 			next_bcast.tv_sec = now.tv_sec+MIN_WAITTIME;
    783 
    784 		for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
    785 			ifp->int_query_time = NEVER;
    786 			rip_mcast_on(ifp);
    787 		}
    788 		ifinit_timer.tv_sec = now.tv_sec;
    789 
    790 	} else if (ifp != 0
    791 		   && !(ifp->int_state & IS_REMOTE)
    792 		   && ifp->int_rip_sock < 0) {
    793 		/* RIP is off, so ensure there are sockets on which
    794 		 * to listen for queries.
    795 		 */
    796 		ifp->int_rip_sock = get_rip_sock(ifp->int_addr, 0);
    797 	}
    798 
    799 	fix_select();
    800 }
    801 
    802 
    803 /* die if malloc(3) fails
    804  */
    805 void *
    806 rtmalloc(size_t size,
    807 	 const char *msg)
    808 {
    809 	void *p = malloc(size);
    810 	if (p == 0)
    811 		logbad(1,"malloc(%lu) failed in %s", (u_long)size, msg);
    812 	return p;
    813 }
    814 
    815 
    816 /* get a random instant in an interval
    817  */
    818 void
    819 intvl_random(struct timeval *tp,	/* put value here */
    820 	     u_long lo,			/* value is after this second */
    821 	     u_long hi)			/* and before this */
    822 {
    823 	tp->tv_sec = (time_t)(hi == lo
    824 			      ? lo
    825 			      : (lo + random() % ((hi - lo))));
    826 	tp->tv_usec = random() % 1000000;
    827 }
    828 
    829 
    830 void
    831 timevaladd(struct timeval *t1,
    832 	   struct timeval *t2)
    833 {
    834 
    835 	t1->tv_sec += t2->tv_sec;
    836 	if ((t1->tv_usec += t2->tv_usec) >= 1000000) {
    837 		t1->tv_sec++;
    838 		t1->tv_usec -= 1000000;
    839 	}
    840 }
    841 
    842 
    843 /* t1 = t2 - t3
    844  */
    845 static void
    846 timevalsub(struct timeval *t1,
    847 	   struct timeval *t2,
    848 	   struct timeval *t3)
    849 {
    850 	t1->tv_sec = t2->tv_sec - t3->tv_sec;
    851 	if ((t1->tv_usec = t2->tv_usec - t3->tv_usec) < 0) {
    852 		t1->tv_sec--;
    853 		t1->tv_usec += 1000000;
    854 	}
    855 }
    856 
    857 
    858 /* put a message into the system log
    859  */
    860 void
    861 msglog(const char *p, ...)
    862 {
    863 	va_list args;
    864 
    865 	trace_flush();
    866 
    867 	va_start(args, p);
    868 	vsyslog(LOG_ERR, p, args);
    869 	va_end(args);
    870 
    871 	if (ftrace != 0) {
    872 		if (ftrace == stdout)
    873 			(void)fputs("routed: ", ftrace);
    874 		va_start(args, p);
    875 		(void)vfprintf(ftrace, p, args);
    876 		va_end(args);
    877 		(void)fputc('\n', ftrace);
    878 	}
    879 }
    880 
    881 
    882 /* Put a message about a bad system into the system log if
    883  * we have not complained about it recently.
    884  *
    885  * It is desirable to complain about all bad systems, but not too often.
    886  * In the worst case, it is not practical to keep track of all bad systems.
    887  * For example, there can be many systems with the wrong password.
    888  */
    889 void
    890 msglim(struct msg_limit *lim, naddr addr, const char *p, ...)
    891 {
    892 	va_list args;
    893 	int i;
    894 	struct msg_sub *ms1, *ms;
    895 	const char *p1;
    896 
    897 	/* look for the oldest slot in the table
    898 	 * or the slot for the bad router.
    899 	 */
    900 	ms = ms1 = lim->subs;
    901 	for (i = MSG_SUBJECT_N; ; i--, ms1++) {
    902 		if (i == 0) {
    903 			/* Reuse a slot at most once every 10 minutes.
    904 			 */
    905 			if (lim->reuse > now.tv_sec) {
    906 				ms = 0;
    907 			} else {
    908 				ms = ms1;
    909 				lim->reuse = now.tv_sec + 10*60;
    910 			}
    911 			break;
    912 		}
    913 		if (ms->addr == addr) {
    914 			/* Repeat a complaint about a given system at
    915 			 * most once an hour.
    916 			 */
    917 			if (ms->until > now.tv_sec)
    918 				ms = 0;
    919 			break;
    920 		}
    921 		if (ms->until < ms1->until)
    922 			ms = ms1;
    923 	}
    924 	if (ms != 0) {
    925 		ms->addr = addr;
    926 		ms->until = now.tv_sec + 60*60;	/* 60 minutes */
    927 
    928 		trace_flush();
    929 		for (p1 = p; *p1 == ' '; p1++)
    930 			continue;
    931 		va_start(args, p);
    932 		vsyslog(LOG_ERR, p1, args);
    933 		va_end(args);
    934 	}
    935 
    936 	/* always display the message if tracing */
    937 	if (ftrace != 0) {
    938 		va_start(args, p);
    939 		(void)vfprintf(ftrace, p, args);
    940 		(void)fputc('\n', ftrace);
    941 		va_end(args);
    942 	}
    943 }
    944 
    945 
    946 void
    947 logbad(int dump, const char *p, ...)
    948 {
    949 	va_list args;
    950 
    951 	trace_flush();
    952 
    953 	va_start(args, p);
    954 	vsyslog(LOG_ERR, p, args);
    955 	va_end(args);
    956 
    957 	(void)fputs("routed: ", stderr);
    958 	va_start(args, p);
    959 	(void)vfprintf(stderr, p, args);
    960 	va_end(args);
    961 	(void)fputs("; giving up\n",stderr);
    962 	(void)fflush(stderr);
    963 
    964 	if (dump)
    965 		abort();
    966 	exit(1);
    967 }
    968