/*
 * This tool requests configuration info from a multicast router
 * and prints the reply (if any).  Invoke it as:
 *
 *	mrinfo router-name-or-address
 *
 * Written Wed Mar 24 1993 by Van Jacobson (adapted from the
 * multicast mapper written by Pavel Curtis).
 *
 * The lawyers insist we include the following UC copyright notice.
 * The mapper from which this is derived contained a Xerox copyright
 * notice which follows the UC one.  Try not to get depressed noting
 * that the legal gibberish is larger than the program.
 *
 * Copyright (c) 1993 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the Computer Systems
 *	Engineering Group at Lawrence Berkeley Laboratory.
 * 4. Neither the name of the University nor of the Laboratory may be used
 *    to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ---------------------------------
 * Copyright (c) Xerox Corporation 1992. All rights reserved.
 * 
 * License is granted to copy, to use, and to make and to use derivative works
 * for research and evaluation purposes, provided that Xerox is acknowledged
 * in all documentation pertaining to any such copy or derivative work. Xerox
 * grants no other licenses expressed or implied. The Xerox trade name should
 * not be used in any advertising without its written permission.
 * 
 * XEROX CORPORATION MAKES NO REPRESENTATIONS CONCERNING EITHER THE
 * MERCHANTABILITY OF THIS SOFTWARE OR THE SUITABILITY OF THIS SOFTWARE FOR
 * ANY PARTICULAR PURPOSE.  The software is provided "as is" without express
 * or implied warranty of any kind.
 * 
 * These notices must be retained in any copies of any part of this software.
 *
 * original rcsid:
 *   Header: mrinfo.c,v 1.6 93/04/08 15:14:16 van Exp (LBL)
 * From: Id: mrinfo.c,v 1.3 1993/06/24 05:11:16 deering Exp
 *      $Id: mrinfo.c,v 1.2 1994/05/08 15:08:58 brezak Exp $
 */

#ifndef lint
static char rcsid[] = "$Id: mrinfo.c,v 1.2 1994/05/08 15:08:58 brezak Exp $";
#endif

#include <netdb.h>
#include <sys/time.h>
#include "defs.h"
#include <arpa/inet.h>

#define DEFAULT_TIMEOUT	4	/* How long to wait before retrying requests */
#define DEFAULT_RETRIES 3	/* How many times to ask each router */

u_long  our_addr, target_addr = 0;	/* in NET order */
int     debug = 0;
int	nflag = 0;
int     retries = DEFAULT_RETRIES;
int     timeout = DEFAULT_TIMEOUT;
int	target_level;

char   *
inet_name(addr)
	u_long  addr;
{
	struct hostent *e;
	struct in_addr in;

	if (addr == 0)
		return "local";

	if (nflag ||
	    (e = gethostbyaddr((char *)&addr, sizeof(addr), AF_INET)) == NULL) {
		in.s_addr = addr;
		return (inet_ntoa(in));
	}
	return (e->h_name);
}

/*
 * Log errors and other messages to stderr, according to the severity of the
 * message and the current debug level.  For errors of severity LOG_ERR or
 * worse, terminate the program.
 */
void 
log(severity, syserr, format, a, b, c, d, e)
	int     severity, syserr;
	char   *format;
	int     a, b, c, d, e;
{
	char    fmt[100];

	switch (debug) {
	case 0:
		if (severity > LOG_WARNING)
			return;
	case 1:
		if (severity > LOG_NOTICE)
			return;
	case 2:
		if (severity > LOG_INFO)
			return;
	default:
		fmt[0] = '\0';
		if (severity == LOG_WARNING)
			strcat(fmt, "warning - ");
		strncat(fmt, format, 80);
		fprintf(stderr, fmt, a, b, c, d, e);
		if (syserr == 0)
			fprintf(stderr, "\n");
		else if (syserr < sys_nerr)
			fprintf(stderr, ": %s\n", sys_errlist[syserr]);
		else
			fprintf(stderr, ": errno %d\n", syserr);
	}

	if (severity <= LOG_ERR)
		exit(-1);
}

/*
 * Send a neighbors-list request.
 */
void 
ask(dst)
	u_long  dst;
{
	send_igmp(our_addr, dst, IGMP_DVMRP, DVMRP_ASK_NEIGHBORS,
			htonl(MROUTED_LEVEL), 0);
}

void 
ask2(dst)
	u_long  dst;
{
	send_igmp(our_addr, dst, IGMP_DVMRP, DVMRP_ASK_NEIGHBORS2,
			htonl(MROUTED_LEVEL), 0);
}

/*
 * Process an incoming neighbor-list message.
 */
void 
accept_neighbors(src, dst, p, datalen)
	u_long  src, dst;
	u_char *p;
	int     datalen;
{
	u_char *ep = p + datalen;
#define GET_ADDR(a) (a = ((u_long)*p++ << 24), a += ((u_long)*p++ << 16),\
		     a += ((u_long)*p++ << 8), a += *p++)

	printf("%s (%s):\n", inet_fmt(src, s1), inet_name(src));
	while (p < ep) {
		register u_long laddr;
		register u_char metric;
		register u_char thresh;
		register int ncount;

		GET_ADDR(laddr);
		laddr = htonl(laddr);
		metric = *p++;
		thresh = *p++;
		ncount = *p++;
		while (--ncount >= 0) {
			register u_long neighbor;
			GET_ADDR(neighbor);
			neighbor = htonl(neighbor);
			printf("  %s -> ", inet_fmt(laddr, s1));
			printf("%s (%s) [%d/%d]\n", inet_fmt(neighbor, s1),
			       inet_name(neighbor), metric, thresh);
		}
	}
}

void 
accept_neighbors2(src, dst, p, datalen)
	u_long  src, dst;
	u_char *p;
	int     datalen;
{
	u_char *ep = p + datalen;

	printf("%s (%s) [version %d.%d]:\n", inet_fmt(src, s1), inet_name(src),
	       target_level & 0xff, (target_level >> 8) & 0xff);
	while (p < ep) {
		register u_char metric;
		register u_char thresh;
		register u_char flags;
		register int ncount;
		register u_long laddr = *(u_long*)p;

		p += 4;
		metric = *p++;
		thresh = *p++;
		flags = *p++;
		ncount = *p++;
		while (--ncount >= 0) {
			register u_long neighbor = *(u_long*)p;
			p += 4;
			printf("  %s -> ", inet_fmt(laddr, s1));
			printf("%s (%s) [%d/%d", inet_fmt(neighbor, s1),
			       inet_name(neighbor), metric, thresh);
			if (flags & DVMRP_NF_TUNNEL)
				printf("/tunnel");
			if (flags & DVMRP_NF_SRCRT)
				printf("/srcrt");
			if (flags & DVMRP_NF_QUERIER)
				printf("/querier");
			if (flags & DVMRP_NF_DISABLED)
				printf("/disabled");
			if (flags & DVMRP_NF_DOWN)
				printf("/down");
			printf("]\n");
		}
	}
}

int 
get_number(var, deflt, pargv, pargc)
	int    *var, *pargc, deflt;
	char ***pargv;
{
	if ((*pargv)[0][2] == '\0') {	/* Get the value from the next
					 * argument */
		if (*pargc > 1 && isdigit((*pargv)[1][0])) {
			(*pargv)++, (*pargc)--;
			*var = atoi((*pargv)[0]);
			return 1;
		} else if (deflt >= 0) {
			*var = deflt;
			return 1;
		} else
			return 0;
	} else {		/* Get value from the rest of this argument */
		if (isdigit((*pargv)[0][2])) {
			*var = atoi((*pargv)[0] + 2);
			return 1;
		} else {
			return 0;
		}
	}
}

u_long 
host_addr(name)
	char   *name;
{
	struct hostent *e;
	u_long addr;

	addr = inet_addr(name);
	if ((int)addr == -1) {
		e = gethostbyname(name);
		if (e == NULL || e->h_length != sizeof(addr))
			return (0);
		memcpy(&addr, e->h_addr_list[0], e->h_length);
	}
	return (addr);
}

void
usage()
{
	fprintf(stderr,
	    "Usage: mrinfo [-n] [-t timeout] [-r retries] [router]\n");
	exit(1);
}

main(argc, argv)
	int     argc;
	char   *argv[];
{
	setlinebuf(stderr);

	if (geteuid() != 0) {
		fprintf(stderr, "mrinfo: must be root\n");
		exit(1);
	}
	argv++, argc--;
	while (argc > 0 && argv[0][0] == '-') {
		switch (argv[0][1]) {
		case 'd':
			if (!get_number(&debug, DEFAULT_DEBUG, &argv, &argc))
				usage();
			break;
		case 'n':
			++nflag;
			break;
		case 'r':
			if (!get_number(&retries, -1, &argv, &argc))
				usage();
			break;
		case 't':
			if (!get_number(&timeout, -1, &argv, &argc))
				usage();
			break;
		default:
			usage();
		}
		argv++, argc--;
	}
	if (argc > 1)
		usage();
	if (argc == 1)
		target_addr = host_addr(argv[0]);
	else
		target_addr = host_addr("127.0.0.1");

	if (target_addr == 0) {
		fprintf(stderr, "mrinfo: %s: no such host\n", argv[0]);
		exit(1);
	}
	if (debug)
		fprintf(stderr, "Debug level %u\n", debug);

	init_igmp();

	{			/* Find a good local address for us. */
		int     udp;
		struct sockaddr_in addr;
		int     addrlen = sizeof(addr);

		addr.sin_family = AF_INET;
		addr.sin_addr.s_addr = target_addr;
		addr.sin_port = htons(2000);	/* any port over 1024 will
						 * do... */
		if ((udp = socket(AF_INET, SOCK_DGRAM, 0)) < 0
		|| connect(udp, (struct sockaddr *) & addr, sizeof(addr)) < 0
		    || getsockname(udp, (struct sockaddr *) & addr, &addrlen) < 0) {
			perror("Determining local address");
			exit(-1);
		}
		close(udp);
		our_addr = addr.sin_addr.s_addr;
	}

	ask(target_addr);

	/* Main receive loop */
	for (;;) {
		fd_set  fds;
		struct timeval tv;
		int     count, recvlen, dummy = 0;
		register u_long src, dst, group;
		struct ip *ip;
		struct igmp *igmp;
		int     ipdatalen, iphdrlen, igmpdatalen;

		FD_ZERO(&fds);
		FD_SET(igmp_socket, &fds);

		tv.tv_sec = timeout;
		tv.tv_usec = 0;

		count = select(igmp_socket + 1, &fds, 0, 0, &tv);

		if (count < 0) {
			if (errno != EINTR)
				perror("select");
			continue;
		} else if (count == 0) {
			log(LOG_DEBUG, 0, "Timed out receiving neighbor lists");
			if (--retries < 0)
				exit(1);
			if (target_level == 0)
				ask(target_addr);
			else
				ask2(target_addr);
			continue;
		}
		recvlen = recvfrom(igmp_socket, recv_buf, sizeof(recv_buf),
				   0, NULL, &dummy);
		if (recvlen <= 0) {
			if (recvlen && errno != EINTR)
				perror("recvfrom");
			continue;
		}

		if (recvlen < sizeof(struct ip)) {
			log(LOG_WARNING, 0,
			    "packet too short (%u bytes) for IP header",
			    recvlen);
			continue;
		}
		ip = (struct ip *) recv_buf;
		src = ip->ip_src.s_addr;
		if (src != target_addr) {
			fprintf(stderr, "mrinfo: got reply from %s",
				inet_fmt(src, s1));
			fprintf(stderr, " instead of %s\n",
				inet_fmt(target_addr, s1));
			continue;
		}
		dst = ip->ip_dst.s_addr;
		iphdrlen = ip->ip_hl << 2;
		ipdatalen = ip->ip_len;
		if (iphdrlen + ipdatalen != recvlen) {
			log(LOG_WARNING, 0,
			    "packet shorter (%u bytes) than hdr+data length (%u+%u)",
			    recvlen, iphdrlen, ipdatalen);
			continue;
		}
		igmp = (struct igmp *) (recv_buf + iphdrlen);
		group = igmp->igmp_group.s_addr;
		igmpdatalen = ipdatalen - IGMP_MINLEN;
		if (igmpdatalen < 0) {
			log(LOG_WARNING, 0,
			    "IP data field too short (%u bytes) for IGMP, from %s",
			    ipdatalen, inet_fmt(src, s1));
			continue;
		}
		if (igmp->igmp_type != IGMP_DVMRP)
			continue;

		switch (igmp->igmp_code) {

		case DVMRP_NEIGHBORS:
			if (group) {
				/* knows about DVMRP_NEIGHBORS2 msg */
				if (target_level == 0) {
					target_level = ntohl(group);
					ask2(target_addr);
				}
			} else {
				accept_neighbors(src, dst, (char *)(igmp + 1),
						 igmpdatalen);
				exit(0);
			}
			break;

		case DVMRP_NEIGHBORS2:
			accept_neighbors2(src, dst, (char *)(igmp + 1),
					  igmpdatalen);
			exit(0);
		}
	}
}

/* dummies */
void accept_probe()
{
}
void accept_group_report()
{
}
void accept_neighbor_request2()
{
}
void accept_report()
{
}
void accept_neighbor_request()
{
}
void check_vif_state()
{
}