mcpe-ping-fixed/index.js

Pings an MCPE server for simple data.

'use strict';
var dgram = require('dgram');
var ByteBuffer = require('bytebuffer');
var portfinder = require('portfinder');
var dns = require('dns');

var START_TIME = new Date().getTime();
var RAKNET = {
  STRUCTURE: 5,
  MAGIC: "00ffff00fefefefefdfdfdfd12345678",
  SERVER_ID: 925686942,
  UNCONNECTED_PING: 0x01,
  UNCONNECTED_PING_OPEN_CONNECTIONS: 0x02,

  OPEN_CONNECTION_REQUEST_1: 0x05,
  OPEN_CONNECTION_REPLY_1: 0x06,
  OPEN_CONNECTION_REQUEST_2: 0x07,
  OPEN_CONNECTION_REPLY_2: 0x08,

  INCOMPATIBLE_PROTOCOL_VERSION: 0x1a, //CHECK THIS

  UNCONNECTED_PONG: 0x1c,
  ADVERTISE_SYSTEM: 0x1d,
  DATA_PACKET_0: 0x80,
  DATA_PACKET_1: 0x81,
  DATA_PACKET_2: 0x82,
  DATA_PACKET_3: 0x83,
  DATA_PACKET_4: 0x84,
  DATA_PACKET_5: 0x85,
  DATA_PACKET_6: 0x86,
  DATA_PACKET_7: 0x87,
  DATA_PACKET_8: 0x88,
  DATA_PACKET_9: 0x89,
  DATA_PACKET_A: 0x8a,
  DATA_PACKET_B: 0x8b,
  DATA_PACKET_C: 0x8c,
  DATA_PACKET_D: 0x8d,
  DATA_PACKET_E: 0x8e,
  DATA_PACKET_F: 0x8f,

  NACK: 0xa0,
  ACK: 0xc0
};
var UNCONNECTED_PING = function (pingId) {
  this.bb = new ByteBuffer();
  this.bb.buffer[0] = RAKNET.UNCONNECTED_PING;
  this.bb.offset = 1;
  this.pingId = pingId;
};
UNCONNECTED_PING.prototype.encode = function () {
//  console.log(this.pingId);
  this.bb.writeLong(this.pingId);
  this.bb.append(RAKNET.MAGIC, "hex");
  this.bb.writeLong(0);
  this.bb.flip();
  this.bb.compact();
};


var UNCONNECTED_PONG = function (buf) {
  this.bb = buf;
  this.bb.offset = 1;
};
UNCONNECTED_PONG.prototype.decode = function () {
  this.pingId = this.bb.readLong();
  this.serverId = this.bb.readLong();
  this.bb.offset += 16;
  this.nameLength = this.bb.readShort();
  try {
    this.advertiseString = this.bb.readUTF8String(this.nameLength);
  }
  catch(e){ //FIXME
    this.advertiseString = this.bb.readUTF8String(parseInt(e.message.substr(e.message.indexOf(",")+2, 3)));
  }
  var splitString = this.advertiseString.split(/;/g);
  this.gameId = splitString[0];
  this.name = splitString[1];
  this.unknownId = splitString[2];
  this.gameVersion = splitString[3];
  this.currentPlayers = splitString[4];
  this.maxPlayers = splitString[5];
};

var ping = function (server, port, callback, timeout) {
  var MCPE_DEFAULT_PORT = 19132;
  if (typeof port === "function") {
    callback = port;
    port = MCPE_DEFAULT_PORT;
  }

  if (typeof port !== "number") {
    port = MCPE_DEFAULT_PORT;
  }

  if (typeof timeout === "undefined") {
    timeout = 5000;
  }
  if(checkIsIPV4(server)){
    pingIP(server, port, callback, timeout)
  }
  else{
    dns.lookup(server, function(err, res){
      if(err === null){
        pingIP(res, port, callback, timeout);
      }
      else{
        callback({error: true, description: "DNS lookup failed."}, null);
      }
    });
  }

};
var pingIP = function (server, port, callback, timeout) {
  var client = dgram.createSocket("udp4");
  var broadcastIntervalId = setInterval((function () {
    try {
      var ping = new UNCONNECTED_PING(new Date().getTime());
      ping.encode();
      client.send(ping.bb.buffer, 0, ping.bb.buffer.length, port, server);
    }
    catch(e){
      clearInterval(broadcastIntervalId);
      clearTimeout(timeoutId);
      client.close();
      callback({error: true, description: "Error sending ping."}, null);
    }
  }).bind(this), 50);
  var timeoutId = setTimeout(function(){
    clearInterval(broadcastIntervalId);
    client.close();
    callback({error: true, description: "Ping session timed out."}, null);
  }, timeout);
  client.on("message", ((function (msg, rinfo) {
//    console.log("Message received" + msg);
    var buf = new ByteBuffer().append(msg, "hex").flip();
    var id = buf.buffer[0];
    switch (id) {
      case RAKNET.UNCONNECTED_PONG:
        var pong = new UNCONNECTED_PONG(buf);
        pong.decode();
        var clientData = {
          'rinfo': rinfo,
          'advertise': pong.advertiseString,
          'serverId': pong.serverId,
          'pingId': pong.pingId,
          'game': pong.gameId,
          'version': pong.gameVersion,
          'name': pong.name,
          'cleanName': pong.name.replace(/\xA7[0-9A-FK-OR]/ig, ''),
          'currentPlayers': pong.currentPlayers,
          'maxPlayers': pong.maxPlayers,
          'ackId': new Date().getTime() - START_TIME,
          'connected': true
        };
        clearInterval(broadcastIntervalId);
        clearTimeout(timeoutId);
        client.close();
        callback(null, clientData);
        break;
      default:
        break;
    }
  }).bind(this)));
};
function checkIsIPV4(entry) {
  var blocks = entry.split(".");
  if(blocks.length === 4) {
    return blocks.every(function(block) {
      return parseInt(block,10) >=0 && parseInt(block,10) <= 255;
    });
  }
  return false;
}
module.exports = ping;