/*
  PIM for Quagga
  Copyright (C) 2008  Everton da Silva Marques

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details.
  
  You should have received a copy of the GNU General Public License
  along with this program; see the file COPYING; if not, write to the
  Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
  MA 02110-1301 USA
  
  $QuaggaId: $Format:%an, %ai, %h$ $
*/

#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <net/if.h>
#include <arpa/inet.h>

#include "pim_igmp_join.h"

const char *prog_name = 0;

static int iface_solve_index(const char *ifname)
{
  struct if_nameindex *ini;
  int ifindex = -1;
  int i;

  if (!ifname)
    return -1;

  ini = if_nameindex();
  if (!ini) {
    int err = errno;
    fprintf(stderr,
	    "%s: interface=%s: failure solving index: errno=%d: %s\n",
	    prog_name, ifname, err, strerror(err));
    errno = err;
    return -1;
  }

  for (i = 0; ini[i].if_index; ++i) {
#if 0
    fprintf(stderr,
	    "%s: interface=%s matching against local ifname=%s ifindex=%d\n",
	    prog_name, ifname, ini[i].if_name, ini[i].if_index);
#endif
    if (!strcmp(ini[i].if_name, ifname)) {
      ifindex = ini[i].if_index;
      break;
    }
  }

  if_freenameindex(ini);

  return ifindex;
}

int main(int argc, const char *argv[])
{
  struct in_addr group_addr;
  struct in_addr source_addr;
  const char *ifname;
  const char *group;
  const char *source;
  int ifindex;
  int result;
  int fd;

  prog_name = argv[0];

  fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
  if (fd < 0) {
    fprintf(stderr,
	    "%s: could not create socket: socket(): errno=%d: %s\n",
	    prog_name, errno, strerror(errno));
    exit(1);
  }

  if (argc != 4) {
    fprintf(stderr,
	    "usage:   %s interface group     source\n"
	    "example: %s eth0      232.1.1.1 1.1.1.1\n",
	    prog_name, prog_name);
    exit(1);
  }

  ifname = argv[1];
  group  = argv[2];
  source = argv[3];

  ifindex = iface_solve_index(ifname);
  if (ifindex < 0) {
    fprintf(stderr, "%s: could not find interface: %s\n",
	    prog_name, ifname);
    exit(1);
  }

  result = inet_pton(AF_INET, group, &group_addr);
  if (result <= 0) {
    fprintf(stderr, "%s: bad group address: %s\n",
	    prog_name, group);
    exit(1);
  }

  result = inet_pton(AF_INET, source, &source_addr);
  if (result <= 0) {
    fprintf(stderr, "%s: bad source address: %s\n",
	    prog_name, source);
    exit(1);
  }

  result = pim_igmp_join_source(fd, ifindex, group_addr, source_addr);
  if (result) {
    fprintf(stderr,
	    "%s: setsockopt(fd=%d) failure for IGMP group %s source %s ifindex %d on interface %s: errno=%d: %s\n",
	    prog_name, fd, group, source, ifindex, ifname,
	    errno, strerror(errno));
    exit(1);
  }

  printf("%s: joined channel (S,G)=(%s,%s) on interface %s\n",
	 prog_name, source, group, ifname);

  printf("%s: waiting...\n", prog_name);

  getchar();

  close(fd);

  printf("%s: left channel (S,G)=(%s,%s) on interface %s\n",
	 prog_name, source, group, ifname);

  exit(0);
}