usr.sbin/mrouted/mrinfo.c

/*
 * 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.
 */

#ifndef lint
static char rcsid[] =
    "@(#) $Id: mrinfo.c,v 1.3 1993/06/24 05:11:16 deering Exp $";
/*  original rcsid:
    "@(#) Header: mrinfo.c,v 1.6 93/04/08 15:14:16 van Exp (LBL)";
*/
#endif

#include <netdb.h>
#include <sys/time.h>
#include "defs.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     retries = DEFAULT_RETRIES;
int     timeout = DEFAULT_TIMEOUT;
int     target_level;

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

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

        e = gethostbyaddr((char *)&addr, sizeof(addr), AF_INET);

        return e ? 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 = gethostbyname(name);
        int     addr;

        if (e)
                memcpy(&addr, e->h_addr_list[0], e->h_length);
        else {
                addr = inet_addr(name);
                if (addr == -1)
                        addr = 0;
        }

        return addr;
}

void
usage()
{
        fprintf(stderr, "Usage: mrinfo [-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 '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();

        target_addr = host_addr(argv[0]);
        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()
{
}