<?php

// Типы пакетов, описаны в структуре, файл src/network/core/udp.h
define('PACKET_UDP_CLIENT_FIND_SERVER', 0);   ///< Queries a game server for game information
define('PACKET_UDP_SERVER_RESPONSE', 1);      ///< Reply of the game server with game information
define('PACKET_UDP_CLIENT_DETAIL_INFO', 2);   ///< Queries a game server about details of the game'); such as companies
define('PACKET_UDP_SERVER_DETAIL_INFO', 3);   ///< Reply of the game server about details of the game'); such as companies
define('PACKET_UDP_SERVER_REGISTER', 4);      ///< Packet to register itself to the master server
define('PACKET_UDP_MASTER_ACK_REGISTER', 5);  ///< Packet indicating registration has succedeed
define('PACKET_UDP_CLIENT_GET_LIST', 6);      ///< Request for serverlist from master server
define('PACKET_UDP_MASTER_RESPONSE_LIST', 7); ///< Response from master server with server ip's + port's
define('PACKET_UDP_SERVER_UNREGISTER', 8);    ///< Request to be removed from the server-list
define('PACKET_UDP_CLIENT_GET_NEWGRFS', 9);   ///< Requests the name for a list of GRFs (GRF_ID and MD5)
define('PACKET_UDP_SERVER_NEWGRFS', 10);      ///< Sends the list of NewGRF's requested.
define('PACKET_UDP_MASTER_SESSION_KEY', 11);  ///< Sends a fresh session key to the client
define('PACKET_UDP_END', 12);                 ///< Must ALWAYS be on the end of this list!! (period)

// Версии сетевого протокола, файл файл src/network/core/config.h
define('NETWORK_GAME_ADMIN_VERSION', 1);    ///< What version of the admin network do we use?
define('NETWORK_GAME_INFO_VERSION', 4);     ///< What version of game-info do we use?
define('NETWORK_COMPANY_INFO_VERSION', 6);  ///< What version of company info is this?
define('NETWORK_MASTER_SERVER_VERSION', 2); ///< What version of master-server-protocol do we use?

// Типы спискоа серверов (server list type), файл src/network/core/udp.h
define('SLT_IPv4', 0);       ///< Get the IPv4 addresses
define('SLT_IPv6', 1);       ///< Get the IPv6 addresses
define('SLT_AUTODETECT', 2); ///< Autodetect the type based on the connection

function format_packet($type, $data)
 {
 if ($type<0 or $type>65535) return false;
 $datlen = strlen($data);
 if ($datlen>65511) return false;
 $result = "   $data";
 $type = pack('C', $type);
 $length = pack('S', $datlen+3);
 $result[0] = $length[0];
 $result[1] = $length[1];
 $result[2] = $type[0];
 return $result;
 }

function recv_packet($sock, $timeout=10)
 {
 static $buffer = '';
 static $buflen = 0;
 $datlen = false;
 $type = false;
 for ($sec=0; $sec<$timeout; $sec++)
  {
  sleep(1);
  while ($data=fread($sock, 512))
   {
   $buffer .= $data;
   $buflen += strlen($data);
   }
  if ($buflen<3) continue;
  if ($datlen===false)
   {
   extract(unpack('Sdatlen/Ctype', substr($buffer, 0, 3)));
   $datlen -= 3;
   }
  if ($buflen-3>=$datlen)
   {
   $result = array($type, substr($buffer, 3, $datlen));
   $buffer = substr($buffer, 3+$datlen);
   $buflen = strlen($buffer);
   return $result;
   }
  }
 return false;
 }

$master_ip = gethostbyname('openttd.org');
if ($master_ip=='openttd.org') die('не могу определить ip-адрес openttd.org');

$sock = fsockopen("udp://$master_ip", 3978);
stream_set_blocking($sock, 0);
$data = pack('CC', NETWORK_MASTER_SERVER_VERSION, SLT_IPv4);
$packet = format_packet(PACKET_UDP_CLIENT_GET_LIST, $data);
fwrite($sock, $packet);
$packet_servers = recv_packet($sock, 10);
if (!is_array($packet_servers)) die('не удалось получить список серверов');
if ($packet_servers[0]<>PACKET_UDP_MASTER_RESPONSE_LIST) die('принят неопознанный пакет (1)');
if (strlen($packet_servers[1])<3) errmsg('принят неверный пакет (1)');
$header = substr($packet_servers[1], 0, 3);
extract(unpack('Cproto/Sservnum', $header));
preg_match_all('/[\x00-\xFF]{6}/', substr($packet_servers[1], 3), $addrs);

$servers = array();
foreach ($addrs[0] as $addr)
 {
 extract(unpack('Nip/Sport', $addr));
 $servers[]= array(long2ip($ip), $port);
 }

print_r($servers);

?>