Minecraft server Query in PHP (updated 2013-01-15)

<?php

// A simple version of server query.
// Only returns the MOTD and the number of players and max players.
// Should work even when enable-query=false in the server.properties
function ping($host, $port = 25565, $timeout_s = 1, $timeout_us = 0)
{
    $errno = 0;
    $errstr = "";

    //Set up our socket
    $fp = @fsockopen("tcp://" . $host, $port, $errno, $errstr);

    if(!$fp)
    {
        //echo "no socket!<br />\n";
        return array();
    }

    //Send 0xFE: Server list ping
    fwrite($fp, "\xFE");

    // Set the time out limit
    stream_set_timeout($fp, $timeout_s, $timeout_us);
    $arr = stream_get_meta_data($fp);

    if($arr['timed_out'])
    {
        //echo "timed out!<br />\n";
        return array();
    }

    //Read as much data as we can (max packet size: 241 bytes)
    $d = fread($fp, 256);

    //Check we've got a 0xFF Disconnect
    if($d[0] != "\xFF")
    {
        //echo "not a disconnect!<br />\n";
        return array();
    }

    //Remove the packet ident (0xFF) and the short containing the length of the string
    $d = substr($d, 3);

    //Decode UCS-2 string
    $d = mb_convert_encoding($d, 'auto', 'UCS-2');

    //Split into array
    $d = explode("\xA7", $d);

    //Return an associative array of values
    return array(
            'motd'      => $d[0],
            'players'   => intval($d[1]),
            'max_players'   => intval($d[2])
        );
}


// A verbose version of server query. Requires enable-query=true in server.properties
function full_stat($host, $port = 25565, $timeout_s = 1, $timeout_us = 0)
{
    $errno = 0;
    $errstr = "";

    //Set up our socket
    $fp = @fsockopen("udp://" . $host, $port, $errno, $errstr);

    if(!$fp)
    {
        //echo "no socket!<br />\n";
        return array();
    }

    // Handshake:
    // Get the challenge token; send 0xFE 0xFD 0x09 and a 4-byte session id
    $str1 = "\xFE\xFD\x09\x00\x00\x00\x01"; // Arbitrary session id at the end (4 bytes) (we use 00 00 00 01 here)
    fwrite($fp, $str1);

    // Set the time out limit
    stream_set_timeout($fp, $timeout_s, $timeout_us);
    $arr = stream_get_meta_data($fp);

    if($arr['timed_out'])
    {
        //echo "timed out!<br />\n";
        return array();
    }

    $resp = fread($fp, 4096);

    // Check that we got something back
    if(strlen($resp) == 0)
    {
        //echo "empty response!<br />\n";
        return array();
    }

    // Check for a valid response
    if($resp[0] != "\x09")
    {
        //echo "not a valid response!<br />\n";
        return array();
    }

    // Parse the challenge token from string to integer
    $token = 0;
    for($i = 5; $i < (strlen($resp) - 1); $i++)
    {
        $token *= 10;
        $token += $resp[$i];
    }

    // Divide the int32 into 4 bytes
    $token_arr = array( 0 => ($token / (256*256*256)) % 256,
                1 => ($token / (256*256)) % 256,
                2 => ($token / 256) % 256,
                3 => ($token % 256)
            );

    // Note that the challenge token is bound to your IP and port (as opposed to the [session ID]), and
    // lasts up to 30 seconds. You read that right, it's up to; it's not "your token will expire
    // after 30 seconds", it's "every token ever" is expired every 30 seconds. This means it's entirely
    // possible that you may get a token and use it within the same second and have it expire.

    // Get the full version of server status
    // Session ID and challenge tokens appended to magic header 0xFE 0xFD and command byte 0x00
    // Payload padded to 8 bytes
    $str = "\xFE\xFD\x00\x00\x00\x00\x01"
        . chr($token_arr[0]) . chr($token_arr[1]) . chr($token_arr[2]) . chr($token_arr[3])
        . "\x00\x00\x00\x00";
    fwrite($fp, $str);

    $data = fread($fp, 4096);
    $full_stat = substr($data, 16);     // Strip the crap from the start

    $tmp = explode("\x00\x01player_\x00\x00", $full_stat);  // First, split the payload in two parts
    $keysvalues = explode("\x00", $tmp[0]);         // Divide the first part from every NULL-terminated string end into key1 val1 key2 val2...
    unset($keysvalues[count($keysvalues) - 1]);     // Unset the last entry, because the are two 0x00 bytes at the end

    // Strip all the NULL-bytes from the end of the player list
    $tmp = $tmp[1];
    $i = strlen($tmp) - 1;
    while($i >= 0)
    {
        if(ord($tmp[$i]) != 0)
        {
            break;
        }
        $i--;
    }

    // Split the player information (if any)
    if($i > 0)
    {
        $tmp = substr($tmp, 0, $i + 1);
        $players = explode("\x00", $tmp);       // Explode the player information from the NULL-byte positions
    }
    else
    {
        $tmp = FALSE;
    }

    // Arrange the key => value pairs into an array
    $info = array();
    for($i = 0; $i < count($keysvalues); $i += 2)
    {
        if($keysvalues[$i] == "")
            break;

        $info[$keysvalues[$i]] = $keysvalues[$i + 1];
    }

    // Collect all the information into one array
    $full_stat = $info;
    $full_stat['players'] = $players;

    return $full_stat;
}

// -----------------------------------------------------------------------------------------

// These are here as an example and to test that the query works. You can edit the addresses to match
// your server, and have the script dump the "raw" arrays with all the data.
// If you only have one server, an easy example of usage would be:
// $data = full_stat("some.addre.ss", 25565);
// Just change the address and port to match your server.
// You can add timeout values after the port, the default timeout is 1 second:
// $data = full_stat("some.addre.ss", 25565, 0, 300000);
// The first value is in seconds and the second is in microseconds. So the example above
// would timeout after 300 000 microseconds = 300 milliseconds = 0.3 seconds

// Note that the full_stat() function will only work if the server has query enabled
// ie. enable-query=true in server.properties file.
// The ping() function should always work, as it uses the same method that the client does
// in the server list menu (and thus only has the same data to display, MOTD and players/max players).
// After you have your data, for example in the $data variable as in the example above, you
// can then print what you want from it. The possible keys are easily seen if running
// the test below, as it dumps the full arrays.
// The keys are in brackets (for example [hostname]), so when you want
// to print it, use some of PHP's print methods, for example echo:
// echo $data['hostname'];
// or printf:
// printf("Hostname follows this example: %s\n", $data['hostname']);

// To recap: to test this script for your server:
// 1. Save this script to your web server, for example as a test.php
// 2. Edit the array below to include your server (address and port).
// You can delete the rest of the example servers.
// Use either full_stat, if you have enable-query=true, or ping, if you have enable-query=false.
// Ping will of course work also when enable-query=true.
// 3. Load the page in your web browser. If everything works, you should see an array with
// some data about you server. You can use the keys shown in brackets to print only
// the data you want in your final page.
// echo $data['hostname']; if using the example above or
// echo $servers['foo']['hostname']; if using the array below (foo is just a key/index in the array for the given server)

// Put your server(s) here to test the query:
$servers = array(
    'server1'   => full_stat("some.addre.ss", 25565),
    'server2'   => full_stat("some.addre.ss", 25590),
    'foo'       => full_stat("some.addre.ss", 25565, 2, 0), // An example with a 2 second timeout
    'pingserver'    => ping("some.addre.ss", 25585, 2, 0)
);

// Dump all the test data:
echo "<pre>\n";

foreach($servers as $server => $data)
{
    echo "$server:\n";
    print_r($data);
}

echo "</pre>\n";

?>