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mrinfo.c revision 1.4
      1 /*	$NetBSD: mrinfo.c,v 1.4 1995/12/10 11:00:51 mycroft Exp $	*/
      2 
      3 /*
      4  * This tool requests configuration info from a multicast router
      5  * and prints the reply (if any).  Invoke it as:
      6  *
      7  *	mrinfo router-name-or-address
      8  *
      9  * Written Wed Mar 24 1993 by Van Jacobson (adapted from the
     10  * multicast mapper written by Pavel Curtis).
     11  *
     12  * The lawyers insist we include the following UC copyright notice.
     13  * The mapper from which this is derived contained a Xerox copyright
     14  * notice which follows the UC one.  Try not to get depressed noting
     15  * that the legal gibberish is larger than the program.
     16  *
     17  * Copyright (c) 1993 Regents of the University of California.
     18  * All rights reserved.
     19  *
     20  * Redistribution and use in source and binary forms, with or without
     21  * modification, are permitted provided that the following conditions
     22  * are met:
     23  * 1. Redistributions of source code must retain the above copyright
     24  *    notice, this list of conditions and the following disclaimer.
     25  * 2. Redistributions in binary form must reproduce the above copyright
     26  *    notice, this list of conditions and the following disclaimer in the
     27  *    documentation and/or other materials provided with the distribution.
     28  * 3. All advertising materials mentioning features or use of this software
     29  *    must display the following acknowledgement:
     30  *	This product includes software developed by the Computer Systems
     31  *	Engineering Group at Lawrence Berkeley Laboratory.
     32  * 4. Neither the name of the University nor of the Laboratory may be used
     33  *    to endorse or promote products derived from this software without
     34  *    specific prior written permission.
     35  *
     36  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     37  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     39  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     40  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     41  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     42  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     43  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     44  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     45  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     46  * SUCH DAMAGE.
     47  * ---------------------------------
     48  * Copyright (c) Xerox Corporation 1992. All rights reserved.
     49  *
     50  * License is granted to copy, to use, and to make and to use derivative works
     51  * for research and evaluation purposes, provided that Xerox is acknowledged
     52  * in all documentation pertaining to any such copy or derivative work. Xerox
     53  * grants no other licenses expressed or implied. The Xerox trade name should
     54  * not be used in any advertising without its written permission.
     55  *
     56  * XEROX CORPORATION MAKES NO REPRESENTATIONS CONCERNING EITHER THE
     57  * MERCHANTABILITY OF THIS SOFTWARE OR THE SUITABILITY OF THIS SOFTWARE FOR
     58  * ANY PARTICULAR PURPOSE.  The software is provided "as is" without express
     59  * or implied warranty of any kind.
     60  *
     61  * These notices must be retained in any copies of any part of this software.
     62  */
     63 
     64 #ifndef lint
     65 static char rcsid[] =
     66     "@(#) $NetBSD: mrinfo.c,v 1.4 1995/12/10 11:00:51 mycroft Exp $";
     67 /*  original rcsid:
     68     "@(#) Header: mrinfo.c,v 1.6 93/04/08 15:14:16 van Exp (LBL)";
     69 */
     70 #endif
     71 
     72 #include <string.h>
     73 #include <netdb.h>
     74 #include <sys/time.h>
     75 #include "defs.h"
     76 #include <arpa/inet.h>
     77 #ifdef __STDC__
     78 #include <stdarg.h>
     79 #else
     80 #include <varargs.h>
     81 #endif
     82 
     83 #define DEFAULT_TIMEOUT	4	/* How long to wait before retrying requests */
     84 #define DEFAULT_RETRIES 3	/* How many times to ask each router */
     85 
     86 u_int32_t	our_addr, target_addr = 0;	/* in NET order */
     87 int     debug = 0;
     88 int	nflag = 0;
     89 int     retries = DEFAULT_RETRIES;
     90 int     timeout = DEFAULT_TIMEOUT;
     91 int	target_level = 0;
     92 vifi_t  numvifs;		/* to keep loader happy */
     93 				/* (see COPY_TABLES macro called in kern.c) */
     94 
     95 char *			inet_name __P((u_int32_t addr));
     96 void			ask __P((u_int32_t dst));
     97 void			ask2 __P((u_int32_t dst));
     98 int			get_number __P((int *var, int deflt, char ***pargv,
     99 					int *pargc));
    100 u_int32_t			host_addr __P((char *name));
    101 void			usage __P((void));
    102 
    103 /* to shut up -Wstrict-prototypes */
    104 int			main __P((int argc, char *argv[]));
    105 
    106 
    107 char   *
    108 inet_name(addr)
    109 	u_int32_t  addr;
    110 {
    111 	struct hostent *e;
    112 	struct in_addr in;
    113 
    114 	if (addr == 0)
    115 		return "local";
    116 
    117 	if (nflag ||
    118 	    (e = gethostbyaddr((char *)&addr, sizeof(addr), AF_INET)) == NULL) {
    119 		in.s_addr = addr;
    120 		return (inet_ntoa(in));
    121 	}
    122 	return (e->h_name);
    123 }
    124 
    125 /*
    126  * Log errors and other messages to stderr, according to the severity of the
    127  * message and the current debug level.  For errors of severity LOG_ERR or
    128  * worse, terminate the program.
    129  */
    130 #ifdef __STDC__
    131 void
    132 log(int severity, int syserr, char *format, ...)
    133 {
    134 	va_list ap;
    135 	char    fmt[100];
    136 
    137 	va_start(ap, format);
    138 #else
    139 void
    140 log(severity, syserr, format, va_alist)
    141 	int     severity, syserr;
    142 	char   *format;
    143 	va_dcl
    144 {
    145 	va_list ap;
    146 	char    fmt[100];
    147 
    148 	va_start(ap);
    149 #endif
    150 	switch (debug) {
    151 	case 0:
    152 		if (severity > LOG_WARNING)
    153 			return;
    154 	case 1:
    155 		if (severity > LOG_NOTICE)
    156 			return;
    157 	case 2:
    158 		if (severity > LOG_INFO)
    159 			return;
    160 	default:
    161 		fmt[0] = '\0';
    162 		if (severity == LOG_WARNING)
    163 			strcat(fmt, "warning - ");
    164 		strncat(fmt, format, 80);
    165 		vfprintf(stderr, fmt, ap);
    166 		if (syserr == 0)
    167 			fprintf(stderr, "\n");
    168 		else if (syserr < sys_nerr)
    169 			fprintf(stderr, ": %s\n", sys_errlist[syserr]);
    170 		else
    171 			fprintf(stderr, ": errno %d\n", syserr);
    172 	}
    173 
    174 	if (severity <= LOG_ERR)
    175 		exit(-1);
    176 }
    177 
    178 /*
    179  * Send a neighbors-list request.
    180  */
    181 void
    182 ask(dst)
    183 	u_int32_t  dst;
    184 {
    185 	send_igmp(our_addr, dst, IGMP_DVMRP, DVMRP_ASK_NEIGHBORS,
    186 			htonl(MROUTED_LEVEL), 0);
    187 }
    188 
    189 void
    190 ask2(dst)
    191 	u_int32_t  dst;
    192 {
    193 	send_igmp(our_addr, dst, IGMP_DVMRP, DVMRP_ASK_NEIGHBORS2,
    194 			htonl(MROUTED_LEVEL), 0);
    195 }
    196 
    197 /*
    198  * Process an incoming neighbor-list message.
    199  */
    200 void
    201 accept_neighbors(src, dst, p, datalen, level)
    202 	u_int32_t	src, dst, level;
    203 	u_char	*p;
    204 	int     datalen;
    205 {
    206 	u_char *ep = p + datalen;
    207 #define GET_ADDR(a) (a = ((u_int32_t)*p++ << 24), a += ((u_int32_t)*p++ << 16),\
    208 		     a += ((u_int32_t)*p++ << 8), a += *p++)
    209 
    210 	printf("%s (%s):\n", inet_fmt(src, s1), inet_name(src));
    211 	while (p < ep) {
    212 		register u_int32_t laddr;
    213 		register u_char metric;
    214 		register u_char thresh;
    215 		register int ncount;
    216 
    217 		GET_ADDR(laddr);
    218 		laddr = htonl(laddr);
    219 		metric = *p++;
    220 		thresh = *p++;
    221 		ncount = *p++;
    222 		while (--ncount >= 0) {
    223 			register u_int32_t neighbor;
    224 			GET_ADDR(neighbor);
    225 			neighbor = htonl(neighbor);
    226 			printf("  %s -> ", inet_fmt(laddr, s1));
    227 			printf("%s (%s) [%d/%d]\n", inet_fmt(neighbor, s1),
    228 			       inet_name(neighbor), metric, thresh);
    229 		}
    230 	}
    231 }
    232 
    233 void
    234 accept_neighbors2(src, dst, p, datalen, level)
    235 	u_int32_t	src, dst, level;
    236 	u_char	*p;
    237 	int     datalen;
    238 {
    239 	u_char *ep = p + datalen;
    240 	u_int broken_cisco = ((level & 0xffff) == 0x020a); /* 10.2 */
    241 	/* well, only possibly_broken_cisco, but that's too long to type. */
    242 
    243 	printf("%s (%s) [version %d.%d", inet_fmt(src, s1), inet_name(src),
    244 	       level & 0xff, (level >> 8) & 0xff);
    245 	if ((level >> 16) & NF_LEAF)   { printf (",leaf"); }
    246 	if ((level >> 16) & NF_PRUNE)  { printf (",prune"); }
    247 	if ((level >> 16) & NF_GENID)  { printf (",genid"); }
    248 	if ((level >> 16) & NF_MTRACE) { printf (",mtrace"); }
    249 	printf ("]:\n");
    250 
    251 	while (p < ep) {
    252 		register u_char metric;
    253 		register u_char thresh;
    254 		register u_char flags;
    255 		register int ncount;
    256 		register u_int32_t laddr = *(u_int32_t*)p;
    257 
    258 		p += 4;
    259 		metric = *p++;
    260 		thresh = *p++;
    261 		flags = *p++;
    262 		ncount = *p++;
    263 		if (broken_cisco && ncount == 0)	/* dumb Ciscos */
    264 			ncount = 1;
    265 		if (broken_cisco && ncount > 15)	/* dumb Ciscos */
    266 			ncount = ncount & 0xf;
    267 		while (--ncount >= 0 && p < ep) {
    268 			register u_int32_t neighbor = *(u_int32_t*)p;
    269 			p += 4;
    270 			printf("  %s -> ", inet_fmt(laddr, s1));
    271 			printf("%s (%s) [%d/%d", inet_fmt(neighbor, s1),
    272 			       inet_name(neighbor), metric, thresh);
    273 			if (flags & DVMRP_NF_TUNNEL)
    274 				printf("/tunnel");
    275 			if (flags & DVMRP_NF_SRCRT)
    276 				printf("/srcrt");
    277 			if (flags & DVMRP_NF_PIM)
    278 				printf("/pim");
    279 			if (flags & DVMRP_NF_QUERIER)
    280 				printf("/querier");
    281 			if (flags & DVMRP_NF_DISABLED)
    282 				printf("/disabled");
    283 			if (flags & DVMRP_NF_DOWN)
    284 				printf("/down");
    285 			if (flags & DVMRP_NF_LEAF)
    286 				printf("/leaf");
    287 			printf("]\n");
    288 		}
    289 	}
    290 }
    291 
    292 int
    293 get_number(var, deflt, pargv, pargc)
    294 	int    *var, *pargc, deflt;
    295 	char ***pargv;
    296 {
    297 	if ((*pargv)[0][2] == '\0') {	/* Get the value from the next
    298 					 * argument */
    299 		if (*pargc > 1 && isdigit((*pargv)[1][0])) {
    300 			(*pargv)++, (*pargc)--;
    301 			*var = atoi((*pargv)[0]);
    302 			return 1;
    303 		} else if (deflt >= 0) {
    304 			*var = deflt;
    305 			return 1;
    306 		} else
    307 			return 0;
    308 	} else {		/* Get value from the rest of this argument */
    309 		if (isdigit((*pargv)[0][2])) {
    310 			*var = atoi((*pargv)[0] + 2);
    311 			return 1;
    312 		} else {
    313 			return 0;
    314 		}
    315 	}
    316 }
    317 
    318 void
    319 usage()
    320 {
    321 	fprintf(stderr,
    322 	    "Usage: mrinfo [-n] [-t timeout] [-r retries] [router]\n");
    323 	exit(1);
    324 }
    325 
    326 int
    327 main(argc, argv)
    328 	int     argc;
    329 	char   *argv[];
    330 {
    331 	int tries;
    332 	int trynew;
    333 	struct timeval et;
    334 	struct hostent *hp;
    335 	struct hostent bogus;
    336 	char *host;
    337 	int curaddr;
    338 
    339 	setlinebuf(stderr);
    340 
    341 	if (geteuid() != 0) {
    342 		fprintf(stderr, "mrinfo: must be root\n");
    343 		exit(1);
    344 	}
    345 	argv++, argc--;
    346 	while (argc > 0 && argv[0][0] == '-') {
    347 		switch (argv[0][1]) {
    348 		case 'd':
    349 			if (!get_number(&debug, DEFAULT_DEBUG, &argv, &argc))
    350 				usage();
    351 			break;
    352 		case 'n':
    353 			++nflag;
    354 			break;
    355 		case 'r':
    356 			if (!get_number(&retries, -1, &argv, &argc))
    357 				usage();
    358 			break;
    359 		case 't':
    360 			if (!get_number(&timeout, -1, &argv, &argc))
    361 				usage();
    362 			break;
    363 		default:
    364 			usage();
    365 		}
    366 		argv++, argc--;
    367 	}
    368 	if (argc > 1)
    369 		usage();
    370 	if (argc == 1)
    371 		host = argv[0];
    372 	else
    373 		host = "127.0.0.1";
    374 
    375 	if ((target_addr = inet_addr(host)) != -1) {
    376 		hp = &bogus;
    377 		hp->h_length = sizeof(target_addr);
    378 		hp->h_addr_list = (char **)malloc(2 * sizeof(char *));
    379 		hp->h_addr_list[0] = malloc(hp->h_length);
    380 		memcpy(hp->h_addr_list[0], &target_addr, hp->h_length);
    381 		hp->h_addr_list[1] = 0;
    382 	} else
    383 		hp = gethostbyname(host);
    384 
    385 	if (hp == NULL) {
    386 		fprintf(stderr, "mrinfo: %s: no such host\n", argv[0]);
    387 		exit(1);
    388 	}
    389 	if (debug)
    390 		fprintf(stderr, "Debug level %u\n", debug);
    391 
    392 	init_igmp();
    393 
    394 	/* Check all addresses; mrouters often have unreachable interfaces */
    395 	for (curaddr = 0; hp->h_addr_list[curaddr] != NULL; curaddr++) {
    396 	    memcpy(&target_addr, hp->h_addr_list[curaddr], hp->h_length);
    397 	    {			/* Find a good local address for us. */
    398 		int     udp;
    399 		struct sockaddr_in addr;
    400 		int     addrlen = sizeof(addr);
    401 
    402 		addr.sin_family = AF_INET;
    403 #if (defined(BSD) && (BSD >= 199103))
    404 		addr.sin_len = sizeof addr;
    405 #endif
    406 		addr.sin_addr.s_addr = target_addr;
    407 		addr.sin_port = htons(2000);	/* any port over 1024 will
    408 						 * do... */
    409 		if ((udp = socket(AF_INET, SOCK_DGRAM, 0)) < 0
    410 		|| connect(udp, (struct sockaddr *) & addr, sizeof(addr)) < 0
    411 		    || getsockname(udp, (struct sockaddr *) & addr, &addrlen) < 0) {
    412 			perror("Determining local address");
    413 			exit(-1);
    414 		}
    415 		close(udp);
    416 		our_addr = addr.sin_addr.s_addr;
    417 	    }
    418 
    419 	    tries = 0;
    420 	    trynew = 1;
    421 	    /*
    422 	     * New strategy: send 'ask2' for two timeouts, then fall back
    423 	     * to 'ask', since it's not very likely that we are going to
    424 	     * find someone who only responds to 'ask' these days
    425 	     */
    426 	    ask2(target_addr);
    427 
    428 	    gettimeofday(&et, 0);
    429 	    et.tv_sec += timeout;
    430 
    431 	    /* Main receive loop */
    432 	    for (;;) {
    433 		fd_set  fds;
    434 		struct timeval tv, now;
    435 		int     count, recvlen, dummy = 0;
    436 		register u_int32_t src, dst, group;
    437 		struct ip *ip;
    438 		struct igmp *igmp;
    439 		int     ipdatalen, iphdrlen, igmpdatalen;
    440 
    441 		FD_ZERO(&fds);
    442 		FD_SET(igmp_socket, &fds);
    443 
    444 		gettimeofday(&now, 0);
    445 		tv.tv_sec = et.tv_sec - now.tv_sec;
    446 		tv.tv_usec = et.tv_usec - now.tv_usec;
    447 
    448 		if (tv.tv_usec < 0) {
    449 			tv.tv_usec += 1000000L;
    450 			--tv.tv_sec;
    451 		}
    452 		if (tv.tv_sec < 0)
    453 			tv.tv_sec = tv.tv_usec = 0;
    454 
    455 		count = select(igmp_socket + 1, &fds, 0, 0, &tv);
    456 
    457 		if (count < 0) {
    458 			if (errno != EINTR)
    459 				perror("select");
    460 			continue;
    461 		} else if (count == 0) {
    462 			log(LOG_DEBUG, 0, "Timed out receiving neighbor lists");
    463 			if (++tries > retries)
    464 				break;
    465 			/* If we've tried ASK_NEIGHBORS2 twice with
    466 			 * no response, fall back to ASK_NEIGHBORS
    467 			 */
    468 			if (tries == 2 && target_level == 0)
    469 				trynew = 0;
    470 			if (target_level == 0 && trynew == 0)
    471 				ask(target_addr);
    472 			else
    473 				ask2(target_addr);
    474 			gettimeofday(&et, 0);
    475 			et.tv_sec += timeout;
    476 			continue;
    477 		}
    478 		recvlen = recvfrom(igmp_socket, recv_buf, RECV_BUF_SIZE,
    479 				   0, NULL, &dummy);
    480 		if (recvlen <= 0) {
    481 			if (recvlen && errno != EINTR)
    482 				perror("recvfrom");
    483 			continue;
    484 		}
    485 
    486 		if (recvlen < sizeof(struct ip)) {
    487 			log(LOG_WARNING, 0,
    488 			    "packet too short (%u bytes) for IP header",
    489 			    recvlen);
    490 			continue;
    491 		}
    492 		ip = (struct ip *) recv_buf;
    493 		if (ip->ip_p == 0)
    494 			continue;	/* Request to install cache entry */
    495 		src = ip->ip_src.s_addr;
    496 		dst = ip->ip_dst.s_addr;
    497 		iphdrlen = ip->ip_hl << 2;
    498 		ipdatalen = ip->ip_len;
    499 		if (iphdrlen + ipdatalen != recvlen) {
    500 		    log(LOG_WARNING, 0,
    501 		      "packet shorter (%u bytes) than hdr+data length (%u+%u)",
    502 		      recvlen, iphdrlen, ipdatalen);
    503 		    continue;
    504 		}
    505 		igmp = (struct igmp *) (recv_buf + iphdrlen);
    506 		group = igmp->igmp_group.s_addr;
    507 		igmpdatalen = ipdatalen - IGMP_MINLEN;
    508 		if (igmpdatalen < 0) {
    509 		    log(LOG_WARNING, 0,
    510 			"IP data field too short (%u bytes) for IGMP, from %s",
    511 			ipdatalen, inet_fmt(src, s1));
    512 		    continue;
    513 		}
    514 		if (igmp->igmp_type != IGMP_DVMRP)
    515 			continue;
    516 
    517 		switch (igmp->igmp_code) {
    518 		case DVMRP_NEIGHBORS:
    519 		case DVMRP_NEIGHBORS2:
    520 			if (src != target_addr) {
    521 				fprintf(stderr, "mrinfo: got reply from %s",
    522 					inet_fmt(src, s1));
    523 				fprintf(stderr, " instead of %s\n",
    524 					inet_fmt(target_addr, s1));
    525 				/*continue;*/
    526 			}
    527 			break;
    528 		default:
    529 			continue;	/* ignore all other DVMRP messages */
    530 		}
    531 
    532 		switch (igmp->igmp_code) {
    533 
    534 		case DVMRP_NEIGHBORS:
    535 			if (group) {
    536 				/* knows about DVMRP_NEIGHBORS2 msg */
    537 				if (target_level == 0) {
    538 					target_level = ntohl(group);
    539 					ask2(target_addr);
    540 				}
    541 			} else {
    542 				accept_neighbors(src, dst, (u_char *)(igmp + 1),
    543 						 igmpdatalen, ntohl(group));
    544 				exit(0);
    545 			}
    546 			break;
    547 
    548 		case DVMRP_NEIGHBORS2:
    549 			accept_neighbors2(src, dst, (u_char *)(igmp + 1),
    550 					  igmpdatalen, ntohl(group));
    551 			exit(0);
    552 		}
    553 	    }
    554 	}
    555 	exit(1);
    556 }
    557 
    558 /* dummies */
    559 void accept_probe(src, dst, p, datalen, level)
    560 	u_int32_t src, dst, level;
    561 	char *p;
    562 	int datalen;
    563 {
    564 }
    565 void accept_group_report(src, dst, group, r_type)
    566 	u_int32_t src, dst, group;
    567 	int r_type;
    568 {
    569 }
    570 void accept_neighbor_request2(src, dst)
    571 	u_int32_t src, dst;
    572 {
    573 }
    574 void accept_report(src, dst, p, datalen, level)
    575 	u_int32_t src, dst, level;
    576 	char *p;
    577 	int datalen;
    578 {
    579 }
    580 void accept_neighbor_request(src, dst)
    581 	u_int32_t src, dst;
    582 {
    583 }
    584 void accept_prune(src, dst, p, datalen)
    585 	u_int32_t src, dst;
    586 	char *p;
    587 	int datalen;
    588 {
    589 }
    590 void accept_graft(src, dst, p, datalen)
    591 	u_int32_t src, dst;
    592 	char *p;
    593 	int datalen;
    594 {
    595 }
    596 void accept_g_ack(src, dst, p, datalen)
    597 	u_int32_t src, dst;
    598 	char *p;
    599 	int datalen;
    600 {
    601 }
    602 void add_table_entry(origin, mcastgrp)
    603 	u_int32_t origin, mcastgrp;
    604 {
    605 }
    606 void check_vif_state()
    607 {
    608 }
    609 void accept_leave_message(src, dst, group)
    610 	u_int32_t src, dst, group;
    611 {
    612 }
    613 void accept_mtrace(src, dst, group, data, no, datalen)
    614 	u_int32_t src, dst, group;
    615 	char *data;
    616 	u_int no;
    617 	int datalen;
    618 {
    619 }
    620 void accept_membership_query(src, dst, group, tmo)
    621 	u_int32_t src, dst, group;
    622 	int tmo;
    623 {
    624 }
    625 void accept_info_request(src, dst, p, datalen)
    626 	u_int32_t src, dst;
    627 	u_char *p;
    628 	int datalen;
    629 {
    630 }
    631 void accept_info_reply(src, dst, p, datalen)
    632 	u_int32_t src, dst;
    633 	u_char *p;
    634 	int datalen;
    635 {
    636 }
    637