/*      $NetBSD: mrinfo.c,v 1.4 1995/12/10 11:00:51 mycroft 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 <string.h>
#include <netdb.h>
#include <sys/time.h>
#include "defs.h"
#include <arpa/inet.h>
#include <stdarg.h>
#include <poll.h>
#include <limits.h>
#include <err.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) */

char            *inet_name(u_int32_t addr);
void            ask(u_int32_t dst);
void            ask2(u_int32_t dst);
void            usage(void);

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, char *format, ...)
{
        va_list ap;

        switch (debug) {
        case 0:
                if (severity > LOG_WARNING)
                        return;
        case 1:
                if (severity > LOG_NOTICE)
                        return;
        case 2:
                if (severity > LOG_INFO)
                        return;
        default:
                if (severity == LOG_WARNING)
                        fprintf(stderr, "warning - ");
                va_start(ap, format);
                vfprintf(stderr, format, ap);
                va_end(ap);
                if (syserr == 0)
                        fputc('\n', stderr);
                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(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, s1), inet_name(src));
        while (p < ep) {
                u_char metric, thresh;
                u_int32_t laddr;
                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, s1));
                        printf("%s (%s) [%d/%d]\n", inet_fmt(neighbor, s1),
                            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, s1), 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, thresh, flags;
                u_int32_t laddr = *(u_int32_t*)p;
                int ncount;

                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, 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_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");
                }
        }
}

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

int
main(int argc, char *argv[])
{
        int tries, trynew, curaddr, udp, ch;
        struct hostent *hp, bogus;
        struct sockaddr_in addr;
        socklen_t addrlen;
        struct timeval et;
        char *host;
        uid_t uid;
        const char *errstr;

        if (geteuid() != 0) {
                fprintf(stderr, "mrinfo: must be root\n");
                exit(1);
        }

        init_igmp();

        uid = getuid();
        if (setresuid(uid, uid, uid) == -1)
                err(1, "setresuid");

        setvbuf(stderr, NULL, _IOLBF, 0);

        while ((ch = getopt(argc, argv, "d::nr:t:")) != -1) {
                switch (ch) {
                case 'd':
                        if (!optarg)
                                debug = DEFAULT_DEBUG;
                        else {
                                debug = strtonum(optarg, 0, 3, &errstr);
                                if (errstr) {
                                        warnx("debug level %s", errstr);
                                        debug = DEFAULT_DEBUG;
                                }
                        }
                        break;
                case 'n':
                        ++nflag;
                        break;
                case 'r':
                        retries = strtonum(optarg, 0, INT_MAX, &errstr);
                        if (errstr) {
                                warnx("retries %s", errstr);
                                usage();
                        }
                        break;
                case 't':
                        timeout = strtonum(optarg, 0, INT_MAX, &errstr);
                        if (errstr) {
                                warnx("timeout %s", errstr);
                                usage();
                        }
                        break;
                default:
                        usage();
                }
        }
        argc -= optind;
        argv += optind;
                        
        if (argc > 1)
                usage();
        if (argc == 1)
                host = argv[0];
        else
                host = "127.0.0.1";

        if ((target_addr = inet_addr(host)) != -1) {
                hp = &bogus;
                hp->h_length = sizeof(target_addr);
                if (!(hp->h_addr_list = calloc(2, sizeof(char *))))
                        err(1, "can't allocate memory");
                if (!(hp->h_addr_list[0] = malloc(hp->h_length)))
                        err(1, "can't allocate memory");
                memcpy(hp->h_addr_list[0], &target_addr, hp->h_length);
                hp->h_addr_list[1] = 0;
        } 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], hp->h_length);
                /* Find a good local address for us. */
                addrlen = sizeof(addr);
                memset(&addr, 0, sizeof addr);
                addr.sin_family = AF_INET;
                addr.sin_len = sizeof addr;
                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)) == -1 ||
                    connect(udp, (struct sockaddr *) & addr, sizeof(addr)) == -1 ||
                    getsockname(udp, (struct sockaddr *) & addr, &addrlen) == -1) {
                        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 (;;) {
                        int count, recvlen, ipdatalen, iphdrlen, igmpdatalen;
                        u_int32_t src, dst, group;
                        struct timeval tv, now;
                        socklen_t dummy = 0;
                        struct igmp *igmp;
                        struct ip *ip;
                        struct pollfd pfd[1];

                        pfd[0].fd = igmp_socket;
                        pfd[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)
                                timerclear(&tv);

                        count = poll(pfd, 1, tv.tv_sec * 1000);

                        if (count == -1) {
                                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 < 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 = ntohs(ip->ip_len) - iphdrlen;
                        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, s1));
                                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, s1));
                                        fprintf(stderr, " instead of %s\n",
                                            inet_fmt(target_addr, s1));
                                        /*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)
{
}