Как распознать сервер CS 1.6?

fwrite($fp, "\xFF\xFF\xFF\xFFTSource Engine Query\x00");
$buffer = fread($fp, 4096);
if($buffer && !preg_match("/(csgo|czero|css|source|1.0.0.34)/i", $buffer))
{
    $buffer = substr($buffer, 4);
    if(ord($buffer[0]) === 0)
        return $serv;
    
    if(!function_exists('get_string'))
    {
        function get_string()
        {
            global $buffer;
            $p = 0;
            $str = "";
            
            while(isset($buffer[$p]) && ($buffer[$p] != "\0"))
            {
                $str .= $buffer[$p];
                $p++;
            }
            $buffer = substr($buffer, mb_strlen($str) + 1);
                return $str;
        }
    }
    if(ord($buffer[0]) == 109)
    {
        get_string();
        $serv["hostname"] = trim(get_string());
        $serv["mapname"] = trim(get_string());
        get_string();
        get_string();
        $serv["player"] = ord($buffer[0]);
        $serv["maxplayer"] = ord($buffer[1]);
    }
    elseif(ord($buffer[0]) == 73)
    {
        $buffer = substr($buffer, 2);
        $serv["hostname"] = trim(get_string());
        $serv["mapname"] = trim(get_string());
        get_string();
        get_string();
        $serv["player"] = ord($buffer[2]);
        $serv["maxplayer"] = ord($buffer[3]);
    }
}