SGIP - serverinfo.php - Get info about a specific JJ2 server

<?php
// For SGIP:
// http://djazz.mine.nu/apps/sgip/

header("content-type: text/html");
header("Access-Control-Allow-Origin: *");
set_time_limit(3);

$ip = $_GET['ip'];
$port = isset($_GET['port'])? intval($_GET['port']) : 10052;
$password = isset($_GET['pswd'])? $_GET['pswd'] : '';
$serverVersion = isset($_GET['v']) ? str_pad(substr($_GET['v'], 0, 4), 4, " ") : "24  ";

$result = array();
$result['error'] = 0;
$result['disconnect'] = 0;
$result['pswd_ok'] = 0;

function echoPacket($title, $pack) {
    $len = strlen($pack);
    echo "<!-- Echo of packet $title - START -->\n<table border=\"1\">\n";
    echo "<tr>\n<td> </td>";        //Offsets
    for ($i = 0; $i < $len; $i++) echo "<td>".$i."</td>";
    echo "\n</tr>\n";
    echo "<tr>\n<td>$title (txt):</td>\n";  //echo in text form
    for ($i = 0; $i < $len; $i++) echo "<td>".$pack[$i]."</td>";
    echo "\n</tr>\n";
    echo "<tr>\n<td>$title (hex):</td>\n";  //Echo in hex form
    for ($i = 0; $i < $len; $i++) echo "<td>".strtoupper(str_pad(dechex(ord($pack[$i])), 2, "0", STR_PAD_LEFT))."</td>";
    echo "\n</tr>\n";
    echo "<tr>\n<td>$title (dec):</td>\n";  //Echo in decimal form
    for ($i = 0; $i < $len; $i++) echo "<td>".str_pad(ord($pack[$i]),2,"0",STR_PAD_LEFT)."</td>";
    echo "\n</tr>\n";
    echo "</table>\n<!-- Echo of packet $title - END -->\n";
}

function udpchecksum ($buf) {
    $x = 1;
    $y = 1;
    $size = strlen($buf);
    for($i = 2; $i < $size; $i++) {
        $x += ord($buf[$i]);
        $y += $x;
    }
    $buf[0] = chr($x % 251);
    $buf[1] = chr($y % 251);
    return $buf;
}
function sendTCP($s) {
    global $tcp;
    $s[0] = chr(strlen($s));
    fwrite($tcp, $s, strlen($s));
}
function sendUDP($s) {
    global $udp;
    $s = udpchecksum($s);
    fwrite($udp, $s);
}
$debug_start = microtime(true);

if($password) {
    $fp = fsockopen("udp://".$ip, $port, $errno, $errstr);
    socket_set_timeout ($fp, 3);
    if (!$fp) {
        $result['pswd_ok'] = 0;
    }
    else {

        $pass = "yy"."\x0A".chr(strlen($password)).$password; // Password packet

        $pass = udpchecksum($pass);

        if (fwrite($fp, $pass)) {

            $reply = fread($fp, 26);
            if (!$reply) {
                $result['pswd_ok'] = 0;
            }
            else {
                if (ord($reply[2]) === 11) {    // Check if it's the right packet
                    if(ord($reply[3])) {
                        $result['pswd_ok'] = 1;
                    }
                }
            }
        }
        else {
            $result['pswd_ok'] = 0;
        }
        fclose($fp);
    }
}


$tcp = @fsockopen($ip, $port, $errno, $errstr, 10);
if(!$tcp) {
    $result['error'] = 5;
    echo json_encode($result);
    exit;
}

$toSend = "y\x0F\x00\x00".$serverVersion."\x01";
sendTCP($toSend);

$socknum = -1;
$closed=false;
$totalplayers=0;
$isPlus = false;
$player = array();
while (!$closed && $res = @fread($tcp, 8192)) {
    $p = 0; $j = strlen($res);
    $special = false;
    while ($p < $j) {                                           //Puts all the packets in an array.

        $l = ord(substr($res,$p,1));

        if ($l === 0) $l++;                                     //Safety measure
        if ($isPlus && $special) {
            $res_a[$p] = chr($l).substr($res,$p+2,$l);
            $p+=2;

        } else {
            $res_a[$p] = substr($res,$p,$l);
        }
        $p += $l;
        if ($isPlus && $p < $j && ord($res[$p]) === 0) {
            $p++;
            $special = true;
        }
    }

    foreach ($res_a as $key => $res1) {                     //Loops through packet array

        if($closed) break;
        $packetID = ord(substr($res1,1,1));
        //echo "tcp packet $packetID: ".(microtime(true) - $debug_start)."\n";
        //echo dechex($packetID)." ";
        switch($packetID) {

            case 0x0D:
                if(ord($res1[3]) === $socknum || $socknum === -1) {
                    $result['disconnect'] = ord($res1[2]);

                    $closed = true;
                }
                break;

            case 0x10: //0x10 Server details
                //We're jj2+
                //$toSend = "y\x3F\x20\x01\x00\x00\x03\x00";
                //$toSend = "y\x3F\x20\x00\x02\x00\x00\x00";
                $toSend = "y\x3F\x20\x01\x00\x00\x03\x00";
                sendTCP($toSend);
                $i = 2;
                $socknum = ord($res1[$i++]);
                $playernum = ord($res1[$i++]);

                $lvlFLen = ord($res1[$i++]);
                $result['level'] = substr($res1, 5, $lvlFLen);
                $i += $lvlFLen;
                $i += 8; // Skips CRC lvl + tileset
                $result['gamemode'] = ord($res1[$i++]);
                $result['maxscore'] = ord($res1[$i++]);


                $n = chr(167).chr(124).chr(167)."1"."SGIP"; // Will look like "SGIP joined the game" on nonplus JJ2 servers
                $toSend = "y\x0E\x01".chr($playernum)."\x00"."SGIP".$n."\x00";

                sendTCP($toSend);
                break;

            case 0x12:
                $packetLength = strlen($res1);
                $i = 3;

                while ($packetLength > $i) {
                    //echo decbin(ord($res1[$i-2]))." ".$res1[$i-2]."<br>";
                    $psock = ord(substr($res1,$i,1)); $i++;
                    $pplayer = ord(substr($res1,$i,1)); $i++;
                    $player[$pplayer]['sock'] = $psock;

                    if($isPlus) {
                        $player[$pplayer]['char'] = ord($res1[$i++]);
                        $player[$pplayer]['team'] = ord($res1[$i++]);
                    }
                    else {
                        $pcharTeam = ord(substr($res1,$i,1)); $i++;
                        $player[$pplayer]['char'] = $pcharTeam & 3;
                        $player[$pplayer]['team'] = ($pcharTeam & 16)/16;
                    }

                    $player[$pplayer]['fur'][0] = ord(substr($res1,$i,1)); $i++;
                    $player[$pplayer]['fur'][1] = ord(substr($res1,$i,1)); $i++;
                    $player[$pplayer]['fur'][2] = ord(substr($res1,$i,1)); $i++;
                    $player[$pplayer]['fur'][3] = ord(substr($res1,$i,1)); $i++;

                    $pname = "";
                    while (ord(substr($res1,$i,1)) !== 0) { $pname .= substr($res1,$i,1); $i++; } // Append character to $pname until null
                    $i++;
                    $player[$pplayer]['name'] = htmlentities(utf8_encode($pname));

                    if($psock === $socknum) {
                        unset($player[$pplayer]);

                    }
                    else {
                        $totalplayers++;
                    }

                }
                break;

            case 0x13: // Game initiation
                //sendTCP("y\x1A");

                $closed = true;
                fclose($tcp);

                break;

            case 0x3F:
                $isPlus = true;
                $i = 2;
                list(,$minor,$major) = unpack("v2", substr($res1,$i,4));
                $result['plus']['version'] = $major.".".$minor;
                $i+=4;

                $result['plus']['customMode'] = ord(substr($res1,$i,1)); $i++;
                $result['plus']['startHealth'] = ord(substr($res1,$i,1)); $i++;
                $result['plus']['maxHealth'] = ord(substr($res1,$i,1)); $i++;
                $plusByte = ord(substr($res1,$i,1)); $i++;

                $result['plus']['plusOnly'] = $plusByte&1;
                $result['plus']['friendlyFire'] = ($plusByte>>1)&1;
                $result['plus']['noMovement'] = ($plusByte>>2)&1;
                $result['plus']['noBlink'] = ($plusByte>>3)&1;

                break;

            default:

                break;

        }
    }
}

$result['players'] = $player;
$result['totalplayers'] = $totalplayers;

//echo "all done: ".(microtime(true) - $debug_start)."\n";

echo json_encode($result);