/*      $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)
{
}