User:Pizzahut/msqp.php

This is a code example for querying a Half-Life master server using the PHP language.
See also User:Pizzahut/test.php - a test script in PHP to check which master servers respond.

<?php

/*

Version history

1     - Initial release.
2     - Added option to use the official domain name instead of IPs and retry if
        a timeout occurs.
2.1   - Added more master servers.
2.1.1 - Fixed a bug, program didn't terminate if all master servers time out.
2.1.2 - Removed a now redundant variable.
2.2   - Seeding for long server lists.
      - Removed the domain name because it's often better to try different
        servers.
2.2.1 - Bug fix: Timeout showed wrong master server IP.
      - Bug fix: Check whether the new seed starts with a duplicate or not.
      - Bug fix: Don't close socket twice.
2.3   - Retry queries on timeout if the first query was successful.
2.3.1 - Reading the whole address again if it starts with a zero.
      - Increased timeout to avoid a communication issue.
      - Removed maximum number of timeouts for testing.
2.4   - Again using hl1master.steampowered.com because IPs change often.
      - Endless retries because this server often times out.
2.5   - Trying following ports on timeout or if the response wasn't correct.
2.5.3 - Cosmetic changes (defines, variable name).
2.5.4 - Code optimisation.
2.6   - Repeat until list isn't empty.
*/

// HL1 master server IPs taken from "Steam\config\MasterServer2.vdf".
// "hl1master.steampowered.com" can be used as well.
// Another source for master server IPs: start a game server, type setmaster in server console.
// (This command isn't available on some games, e.g. TF2.)
$master_servers = array("68.177.101.62", "69.28.158.131", "208.64.200.117", "208.64.200.118");

define("MIN_PORT", 27010); // Range of port numbers which the master servers
define("MAX_PORT", 27013); // potentially use.
define("FILTER", '\gamedir\tfc'); // game = Team Fortress Classic
define("REGION", "\xFF"); // region = world
define("TIMEOUT", 2.0); // 2s timeout

function query_timeout(&$socket, $seed)
{
   echo "Sending query to master server.\n";
   stream_set_timeout($socket, TIMEOUT);
   if (!fwrite($socket, "1".REGION."$seed\0".FILTER."\0"))
   {
      fclose($socket);
      exit("fwrite error\n");
   }

   echo "Reading response header.\n";
   stream_set_timeout($socket, TIMEOUT);
   $s = bin2hex(fread($socket, 6));
   $info = stream_get_meta_data($socket);
   if ($info['timed_out'])
      echo "Master server timed out.\n";
   else
   {
      if ($s !== "ffffffff660a")
      {
         fclose($socket);
         if ($s == "")
            echo "Expected ff ff ff ff 66 0a (hex) but got nothing.\n";
         else
            echo "Expected ff ff ff ff 66 0a (hex) but got $s.\n";
         return True;
      }
   }
   return $info['timed_out'];
}

// Connect to master server, return timeout info.
// The socket is passed as reference and thus returned as well.

function master_server_timeout(&$socket, $ip)
{
   $port = MIN_PORT;
   do {
      echo "Connecting to master server \"$ip:$port\".\n";
      $socket = fsockopen("udp://$ip", $port, $errno, $errstr, TIMEOUT);
      if (!$socket) exit("Error $errno : $errstr \n");
      $timeout = query_timeout($socket, "0.0.0.0:0");
      $port = $port + 1;
   } while ($timeout && ($port <= MAX_PORT));
   return $timeout;
}

// Repeat until list isn't empty.

do
{

	// Try all master servers until we find one that isn't timing out.

	do
	   foreach ($master_servers as $ip)
		  if ($timeout=master_server_timeout($socket, $ip))
			 fclose($socket);
		  else
			 break;
	while ($timeout);

	// Read list with server addresses (IP:port).

	$count = 0;
	$old_a1 = 0; $old_a2 = 0; $old_a3 = 0; $old_a4 = 0; $old_a5 = 0;
	$max_timeouts = 6;
	do
	{
	   stream_set_timeout($socket, TIMEOUT);
	   $a1 = ord(fread($socket,1));
	   $info = stream_get_meta_data($socket);
	   if ($info['timed_out'])
	   {
		  $seed = "$old_a1.$old_a2.$old_a3.$old_a4:$old_a5";
		  echo "Seed: $seed\n";
		  while (query_timeout($socket, $seed));
		  stream_set_timeout($socket, TIMEOUT);
		  $a1 = ord(fread($socket,1));
		  $info = stream_get_meta_data($socket);
		  if ($info['timed_out'])
		  {
			 echo "Timeout occured.\n";
			 break;
		  }
		  $check_for_duplicate = 1;
	   }
	   else
		  $check_for_duplicate = 0;

	   // Let's always read the rest of the address (even if it starts with 0) in
	   // order to empty the master server's write buffer. This may avoid subsequent
	   // problems, but I'm paranoid here.
	   $a2 = ord(fread($socket,1));
	   $a3 = ord(fread($socket,1));
	   $a4 = ord(fread($socket,1));
	   $a5 = ord(fread($socket,1))*256 + ord(fread($socket,1));

	   if ($a1 != 0)
	   {
		  if (($check_for_duplicate==0)||($a1!=$old_a1)||($a2!=$old_a2)||
		  ($a3!=$old_a3)||($a4!=$old_a4)||($a5!=$old_a5))
		  {
			 $count++;
			 echo "$count $a1.$a2.$a3.$a4:$a5\n";
		  }
		  $old_a1 = $a1; $old_a2 = $a2; $old_a3 = $a3; $old_a4 = $a4; $old_a5 = $a5;
	   }
	} while ($a1 != 0);
	fclose($socket);

} while ($count == 0);

echo "Retrieved $count server addresses.\n";

?>