<?PHP
    /**
     * Created by Gachl
     * admin@bloodisgood.org
     * Please give credit where credit belongs.
     *
     * Resources used:
     * * http://php.net/pack
     * * https://developer.valvesoftware.com/wiki/Source_RCON_Protocol
     * * My own Rust server
     *
     * License: http://creativecommons.org/licenses/by-nc-sa/4.0/
     */
    class RustRcon
    {
            private $debug = false; // activate this flag if you want to see verbose communication
            private $read_timeout = 2; // 2 seconds read timeout
            private $packet_id = 0;
            private $stream;

            public function Connect($server, $port, $rcon_password)
            {
                    $error = 0;
                    $errorstring = "";
                    $this->stream = @fsockopen("tcp://$server", intval($port), $error, $errorstring);
                    if ($error !== 0 || $errorstring !== "")
                            throw new Exception("Could not connect to rust server: Error($error) $errorstring.");
                    stream_set_timeout($this->stream, 1); // don't take too long for requests
                    $auth = $this->internal_send(++$this->packet_id, 3, $rcon_password);
                    $this->read(); $this->read(); // discard auth messages (throws error on rcon pass)
            }

            public function Disconnect()
            {
                    fclose($this->stream);
            }

            public function Send($command)
            {
                    $this->internal_send(++$this->packet_id, 2, $command);
                    $response[] = $this->read();
                    while ($response[count($response) - 1] != null) // read the shit out of the server
                            $response[] = $this->read();
                    return $response;
            }

            private function internal_send($packet_id, $packet_type, $packet_body)
            {
                    $request = pack('VV', $packet_id, $packet_type) . $packet_body . "\x00\x00";
                    $request = Pack('V', strlen($request)) . $request;

                    if ($this->debug)
                    {
                            echo "> LEN " . strlen($request) . "\n" .
                                             "> ID $packet_id\n" .
                                             "> TYPE $packet_type\n" .
                                             "> BODY $packet_body\n\n\n";
                    }

                    fwrite($this->stream, $request); // Give no shits about how much data was sent
            }

            private function read()
            {
                    // wait 100 cycles if feof (unlikely)
                    $i = 0;
                    while (feof($this->stream))
                    {
                            if (++$i > 100)
                                    return null; // nope.
                    }

                    // try to read the packet size n times before aborting (n seconds)
                    $szr = fread($this->stream, 4);
                    $i = 0;
                    while (strlen($szr) == 0)
                    {
                            if (++$i > $this->read_timeout)
                                    return null; // more nope.
                            $szr = fread($this->stream, 4);
                    }

                    // Let's do this
                    $size = unpack('V', $szr);
                    $id = unpack('V', fread($this->stream, 4));
                    $type = unpack('V', fread($this->stream, 4));
                    $body = fread($this->stream, $size[1] - 8);

                    if ($this->debug)
                    {
                            echo "< LEN ${size[1]}\n" .
                                             "< ID ${id[1]}" . ($id[1] == 0xffffffff ? ' (-1)' : '') . "\n" .
                                             "< TYPE ${type[1]}\n" .
                                             "< BODY " . $body . "\n\n\n";
                    }

                    if ($id[1] == 0xffffffff)
                            throw new Exception("Rcon password invalid.");

                    return $body;
            }
    }