/*      $NetBSD: mrinfo.c,v 1.30 2016/11/17 09:29:01 shm Exp $  */

/*
 * 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) 1992, 2001 Xerox Corporation.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, 
 * are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 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.

 * Neither name of the Xerox, PARC, nor the names of its contributors may be used
 * to endorse or promote products derived from this software 
 * without specific prior written permission. 
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 XEROX CORPORATION 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. 
 */

#include <sys/cdefs.h>
#ifndef lint
#if 0
static char rcsid[] =
    "@(#) Header: mrinfo.c,v 1.6 93/04/08 15:14:16 van Exp (LBL)";
#else
__RCSID("$NetBSD: mrinfo.c,v 1.30 2016/11/17 09:29:01 shm Exp $");
#endif
#endif

#include <ctype.h>
#include <string.h>
#include <netdb.h>
#include <sys/time.h>
#include <poll.h>
#include "defs.h"
#include <arpa/inet.h>
#include <stdarg.h>

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

u_int32_t       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 = 0;
vifi_t  numvifs;                /* to keep loader happy */
                                /* (see COPY_TABLES macro called in kern.c) */

const char *            inet_name(u_int32_t addr);
void                    ask(u_int32_t dst);
void                    ask2(u_int32_t dst);
int                     get_number(int *var, int deflt, char ***pargv,
                                   int *pargc);
u_int32_t               host_addr(char *name);
__dead void                     usage(void);

/* logit() prototyped in defs.h */


const char *
inet_name(u_int32_t 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
logit(int severity, int syserr, const char *format, ...)
{
        va_list ap;

        switch (debug) {
        case 0:
                if (severity > LOG_WARNING)
                        return;
                /* FALLTHROUGH */
        case 1:
                if (severity > LOG_NOTICE)
                        return;
                /* FALLTHROUGH */
        case 2:
                if (severity > LOG_INFO)
                        return;
                /* FALLTHROUGH */
        default:
                if (severity == LOG_WARNING)
                        fprintf(stderr, "warning - ");
                va_start(ap, format);
                vfprintf(stderr, format, ap);
                va_end(ap);
                if (syserr == 0)
                        fprintf(stderr, "\n");
                else
                        fprintf(stderr, ": %s\n", strerror(syserr));
        }

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

/*
 * Send a neighbors-list request.
 */
void 
ask(u_int32_t dst)
{
        send_igmp(our_addr, dst, IGMP_DVMRP, DVMRP_ASK_NEIGHBORS,
                        htonl(MROUTED_LEVEL), 0);
}

void 
ask2(u_int32_t dst)
{
        send_igmp(our_addr, dst, IGMP_DVMRP, DVMRP_ASK_NEIGHBORS2,
                        htonl(MROUTED_LEVEL), 0);
}

/*
 * Process an incoming neighbor-list message.
 */
void 
accept_neighbors(u_int32_t src, u_int32_t dst, u_char *p, int datalen,
                 u_int32_t level)
{
        u_char *ep = p + datalen;
#define GET_ADDR(a) (a = ((u_int32_t)*p++ << 24), a += ((u_int32_t)*p++ << 16),\
                     a += ((u_int32_t)*p++ << 8), a += *p++)

        printf("%s (%s):\n", inet_fmt(src), inet_name(src));
        while (p < ep) {
                u_int32_t laddr;
                u_char metric;
                u_char thresh;
                int ncount;

                GET_ADDR(laddr);
                laddr = htonl(laddr);
                metric = *p++;
                thresh = *p++;
                ncount = *p++;
                while (--ncount >= 0) {
                        u_int32_t neighbor;
                        GET_ADDR(neighbor);
                        neighbor = htonl(neighbor);
                        printf("  %s -> ", inet_fmt(laddr));
                        printf("%s (%s) [%d/%d]\n",
                                inet_fmt(neighbor),
                               inet_name(neighbor), metric, thresh);
                }
        }
}

void 
accept_neighbors2(u_int32_t src, u_int32_t dst, u_char *p, int datalen,
                  u_int32_t level)
{
        u_char *ep = p + datalen;
        u_int broken_cisco = ((level & 0xffff) == 0x020a); /* 10.2 */
        /* well, only possibly_broken_cisco, but that's too long to type. */

        printf("%s (%s) [version %d.%d", inet_fmt(src),
                inet_name(src), level & 0xff, (level >> 8) & 0xff);
        if ((level >> 16) & NF_LEAF)   { printf (",leaf"); }
        if ((level >> 16) & NF_PRUNE)  { printf (",prune"); }
        if ((level >> 16) & NF_GENID)  { printf (",genid"); }
        if ((level >> 16) & NF_MTRACE) { printf (",mtrace"); }
        printf ("]:\n");
        
        while (p < ep) {
                u_char metric;
                u_char thresh;
                u_char flags;
                int ncount;
                u_int32_t laddr = *(u_int32_t*)p;

                p += 4;
                metric = *p++;
                thresh = *p++;
                flags = *p++;
                ncount = *p++;
                if (broken_cisco && ncount == 0)        /* dumb Ciscos */
                        ncount = 1;
                if (broken_cisco && ncount > 15)        /* dumb Ciscos */
                        ncount = ncount & 0xf;
                while (--ncount >= 0 && p < ep) {
                        u_int32_t neighbor = *(u_int32_t*)p;
                        p += 4;
                        printf("  %s -> ", inet_fmt(laddr));
                        printf("%s (%s) [%d/%d",
                                inet_fmt(neighbor),
                                inet_name(neighbor), metric, thresh);
                        if (flags & DVMRP_NF_TUNNEL)
                                printf("/tunnel");
                        if (flags & DVMRP_NF_SRCRT)
                                printf("/srcrt");
                        if (flags & DVMRP_NF_PIM)
                                printf("/pim");
                        if (flags & DVMRP_NF_QUERIER)
                                printf("/querier");
                        if (flags & DVMRP_NF_DISABLED)
                                printf("/disabled");
                        if (flags & DVMRP_NF_DOWN)
                                printf("/down");
                        if (flags & DVMRP_NF_LEAF)
                                printf("/leaf");
                        printf("]\n");
                }
        }
}

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

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

int
main(int argc, char *argv[])
{
        int tries;
        int trynew;
        struct timeval et;
        struct hostent *hp;
        struct hostent bogus;
        const char *host;
        int curaddr;

        if (geteuid() != 0) {
                fprintf(stderr, "mrinfo: must be root\n");
                exit(1);
        }
        init_igmp();
        if (setuid(getuid()) == -1)
                logit(LOG_ERR, errno, "setuid");

        setlinebuf(stderr);

        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)
                host = argv[0];
        else
                host = "127.0.0.1";

        if ((target_addr = inet_addr(host)) != (in_addr_t)-1) {
                hp = &bogus;
                hp->h_length = sizeof(target_addr);
                hp->h_addr_list = (char **)malloc(2 * sizeof(char *));
                if (hp->h_addr_list == NULL)
                        logit(LOG_ERR, errno, "malloc");
                hp->h_addr_list[0] = malloc(hp->h_length);
                if (hp->h_addr_list[0] == NULL)
                        logit(LOG_ERR, errno, "malloc");
                memcpy(hp->h_addr_list[0], &target_addr, hp->h_length);
                hp->h_addr_list[1] = NULL;
        } else
                hp = gethostbyname(host);

        if (hp == NULL || hp->h_length != sizeof(target_addr)) {
                fprintf(stderr, "mrinfo: %s: no such host\n", argv[0]);
                exit(1);
        }
        if (debug)
                fprintf(stderr, "Debug level %u\n", debug);

        /* Check all addresses; mrouters often have unreachable interfaces */
        for (curaddr = 0; hp->h_addr_list[curaddr] != NULL; curaddr++) {
            memcpy(&target_addr, hp->h_addr_list[curaddr], sizeof(target_addr));
            {                   /* Find a good local address for us. */
                int     udp;
                struct sockaddr_in addr;
                socklen_t addrlen = sizeof(addr);

                memset(&addr, 0, sizeof(addr));
                addr.sin_family = AF_INET;
#if (defined(BSD) && (BSD >= 199103))
                addr.sin_len = sizeof addr;
#endif
                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;
            }

            tries = 0;
            trynew = 1;
            /*
             * New strategy: send 'ask2' for two timeouts, then fall back
             * to 'ask', since it's not very likely that we are going to
             * find someone who only responds to 'ask' these days
             */
            ask2(target_addr);

            gettimeofday(&et, 0);
            et.tv_sec += timeout;

            /* Main receive loop */
            for (;;) {
                struct pollfd set[1];
                struct timeval tv, now;
                int     count, recvlen;
                socklen_t dummy;
                u_int32_t src, dst, group;
                struct ip *ip;
                struct igmp *igmp;
                int     ipdatalen, iphdrlen, igmpdatalen;

                set[0].fd = igmp_socket;
                set[0].events = POLLIN;

                gettimeofday(&now, 0);
                tv.tv_sec = et.tv_sec - now.tv_sec;
                tv.tv_usec = et.tv_usec - now.tv_usec;

                if (tv.tv_usec < 0) {
                        tv.tv_usec += 1000000L;
                        --tv.tv_sec;
                }
                if (tv.tv_sec < 0)
                        tv.tv_sec = tv.tv_usec = 0;

                count = poll(set, 1, tv.tv_sec * 1000 + tv.tv_usec / 1000);

                if (count < 0) {
                        if (errno != EINTR)
                                perror("select");
                        continue;
                } else if (count == 0) {
                        logit(LOG_DEBUG, 0, "Timed out receiving neighbor lists");
                        if (++tries > retries)
                                break;
                        /* If we've tried ASK_NEIGHBORS2 twice with
                         * no response, fall back to ASK_NEIGHBORS
                         */
                        if (tries == 2 && target_level == 0)
                                trynew = 0;
                        if (target_level == 0 && trynew == 0)
                                ask(target_addr);
                        else
                                ask2(target_addr);
                        gettimeofday(&et, 0);
                        et.tv_sec += timeout;
                        continue;
                }
                recvlen = recvfrom(igmp_socket, recv_buf, RECV_BUF_SIZE,
                                   0, NULL, &dummy);
                if (recvlen <= 0) {
                        if (recvlen && errno != EINTR)
                                perror("recvfrom");
                        continue;
                }

                if (recvlen < (int)sizeof(struct ip)) {
                        logit(LOG_WARNING, 0,
                            "packet too short (%u bytes) for IP header",
                            recvlen);
                        continue;
                }
                ip = (struct ip *) recv_buf;
                if (ip->ip_p == 0)
                        continue;       /* Request to install cache entry */
                src = ip->ip_src.s_addr;
                dst = ip->ip_dst.s_addr;
                iphdrlen = ip->ip_hl << 2;
                ipdatalen = ip->ip_len;
                if (iphdrlen + ipdatalen != recvlen) {
                    logit(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) {
                    logit(LOG_WARNING, 0,
                        "IP data field too short (%u bytes) for IGMP, from %s",
                        ipdatalen, inet_fmt(src));
                    continue;
                }
                if (igmp->igmp_type != IGMP_DVMRP)
                        continue;

                switch (igmp->igmp_code) {
                case DVMRP_NEIGHBORS:
                case DVMRP_NEIGHBORS2:
                        if (src != target_addr) {
                                fprintf(stderr, "mrinfo: got reply from %s",
                                        inet_fmt(src));
                                fprintf(stderr, " instead of %s\n",
                                        inet_fmt(target_addr));
                                /*continue;*/
                        }
                        break;
                default:
                        continue;       /* ignore all other DVMRP messages */
                }

                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, (u_char *)(igmp + 1),
                                                 igmpdatalen, ntohl(group));
                                exit(0);
                        }
                        break;

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

/* dummies */
void accept_probe(u_int32_t src, u_int32_t dst, char *p, int datalen,
                  u_int32_t level)
{
}
void accept_group_report(u_int32_t src, u_int32_t dst, u_int32_t group,
                         int r_type)
{
}
void accept_neighbor_request2(u_int32_t src, u_int32_t dst)
{
}
void accept_report(u_int32_t src, u_int32_t dst, char *p, int datalen,
                   u_int32_t level)
{
}
void accept_neighbor_request(u_int32_t src, u_int32_t dst)
{
}
void accept_prune(u_int32_t src, u_int32_t dst, char *p, int datalen)
{
}
void accept_graft(u_int32_t src, u_int32_t dst, char *p, int datalen)
{
}
void accept_g_ack(u_int32_t src, u_int32_t dst, char *p, int datalen)
{
}
void add_table_entry(u_int32_t origin, u_int32_t mcastgrp)
{
}
void check_vif_state(void)
{
}
void accept_leave_message(u_int32_t src, u_int32_t dst, u_int32_t group)
{
}
void accept_mtrace(u_int32_t src, u_int32_t dst, u_int32_t group, char *data,
                   u_int no, int datalen)
{
}
void accept_membership_query(u_int32_t src, u_int32_t dst, u_int32_t group,
                             int tmo)
{
}
void accept_info_request(u_int32_t src, u_int32_t dst, u_char *p, int datalen)
{
}
void accept_info_reply(u_int32_t src, u_int32_t dst, u_char *p, int datalen)
{
}