<?php

//Default configuration
$DEF_PROV_ITERATIONS = 10; //Default provider iterations = 30 times.
$DEF_PROV_DELAY = 10; //Default provider delay = 10 seconds
//!Default configuration

/*
  Send a message on UDP.
  For multicast, the IP_str is the multicast address.
*/
function send_msg($data, $IP_str, $port, $localport = 0)
{
  $sock = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);
  socket_bind($sock, '0.0.0.0', $localport);
  socket_sendto($sock, $data, strlen($data), 0, $IP_str, $port);
  socket_close($sock);
}
//!function send_msg

/*
  Listen on multicast.
  Joins MCAST_group on interface specified, listens on port specified.
*/
function listen_multicast($IP_str, $port, $interface_id)
{
  $sock = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP); 
  socket_bind($sock, '0.0.0.0', $port);
  $err = socket_set_option($sock, getprotobyname("ip"), MCAST_JOIN_GROUP, array("group"=>$IP_str,"interface"=>$interface_id));
  while(1)
  {
    $from = '';
    $portfrom = 0;
    socket_recvfrom($sock, $buf, 32768, MSG_WAITALL, $from, $portfrom); 
    echo 'got "', $buf, '" from "', $from, '" and port "', $portfrom, "\"\n";
    //socket_sendto($sock, $buf, strlen($bc_buf), 0, $IP_send, $PORT_send);
  }
  socket_close($sock);
}
//!function listen_multicast

//function router_loop
function router_loop($IP_str_in, $port_in, $IP_str_out, $port_out, $interface_id = 0)
{
  $sock = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP); 
  socket_bind($sock, '0.0.0.0', $port_in);
  $err = socket_set_option($sock, getprotobyname("ip"), MCAST_JOIN_GROUP, array("group"=>$IP_str_in,"interface"=>$interface_id));
  while(1)
  {
    $from = '';
    $portfrom = 0;
    socket_recvfrom($sock, $buf, 32768, MSG_WAITALL, $from, $portfrom); 
    echo 'passing "', $buf, '" from "', $from, '" and port "', $portfrom, "\"\n";
    send_msg($buf, $IP_str_out, $port_out);
    //socket_sendto($sock, $buf, strlen($bc_buf), 0, $IP_send, $PORT_send);
  }
  socket_close($sock);
}
//!function router_loop
//startup
$mode = 0; //0 = error, 1 = provider, 2 = consumer, 3 = router;
$IP_listen = ''; //IP address to listen on. Multicast address.
$Port_listen = 0; //port to listen on.
$IP_send = ''; //IP address to send on. Multicast address, router only.
$Port_send = 0; //port to send on. 

//[provider | consumer | router]
if(strcasecmp($argv[1], 'provider') === 0)
{
  $mode = 1;
}
else if(strcasecmp($argv[1], 'consumer') === 0)
{
  $mode = 2;
}
else if(strcasecmp($argv[1], 'router') === 0)
{
  $mode = 3;
}
//![provider | consumer | router]

//provider
if($mode === 1)
{
  $IP_str = $argv[2];
  $port = $argv[3];
  $buf = $argv[4];
  //set default options
  $iterations = $DEF_PROV_ITERATIONS;
  $delay = $DEF_PROV_DELAY;
  $localport = 0;
  //handle optional things
  $opts = explode(',', $argv[5]);
  foreach($opts as $o)
  {
    $o = explode('=', $o);
    if(strcasecmp($o[0], 'iterations') === 0)
    {
      $iterations = $o[1];
    }
    else if(strcasecmp($o[0], 'delay') === 0)
    {
      $delay = $o[1];
    }
    else if(strcasecmp($o[0], 'localport') === 0)
    {
      $localport = $o[1];
    }
  }
  echo "Provider\nsending messges on ", $IP_str, ':', $port, ' ', $iterations, ' times with a delay of ', $delay, ' seconds.', "\n";
  $i = 0;
  while($iterations === 0 || ++$i <= $iterations)
  {
    send_msg($buf, $IP_str, $port);
    echo "sent\n";
    sleep($delay);
  }
}
//!provider

//consumer
if($mode === 2)
{
  $IP_str = $argv[2];
  $port = $argv[3];
  echo "Consumer:\nListening on ", $IP_str, ':', $port, "\n";
  listen_multicast($IP_str, $port, 0);
}
//!consumer

//router
if($mode === 3)
{
  $IP_str_in = $argv[2];
  $port_in = $argv[3];
  $IP_str_out = $argv[4];
  $port_out = $argv[5];
  echo "Router:\nWhen traffics is recieved on ", $IP_str_in, ':', $port_in, "\nit will be passed onto ", $IP_str_out, ':', $port_out, "\n";
  router_loop($IP_str_in, $port_in, $IP_str_out, $port_out);
}
//!router

//no mode
if($mode === 0)
{
?>
  UDPTrix -- stupid multicast tool
  Usage:
  php udptrix.php [ provider | consumer | router ] 
    provider: 239.194.0.73 5555 "blah" [iterations=32,delay=10,localport=5309]
      IP to multicast onto, port, message. 
      The last parameter is an optional list of comma separated options:
      delay      the number of seconds to wait before reiterating. Default 10.
      iterations the number of iterations. 0 for infinite. Default 10.
      localport  set the source port. 0 for automatic. default 0.
    consumer: 239.194.0.73 5555
      IP of multicast group to join, port to listen on.
    router: 239.194.0.73 5555 239.195.0.73 7777
      Route traffic from multicast group 1 (239.194), listening on port 5555,
      to group 2 (239.195) on port 7777.
<?php
}
?>