node-gamedig/protocols/core.js

var EventEmitter = require('events').EventEmitter,
	dns = require('dns'),
	net = require('net'),
	async = require('async'),
	Class = require('../lib/Class'),
	Reader = require('../lib/reader');

module.exports = Class.extend(EventEmitter,{
	init: function() {
		this._super();
		this.options = {
			tcpTimeout: 1000,
			udpTimeout: 1000
		};
		this.maxAttempts = 1;
		this.attempt = 1;
		this.finished = false;
		this.encoding = 'utf8';
		this.byteorder = 'le';
		this.delimiter = '\0';

		var self = this;
		this.globalTimeoutTimer = setTimeout(function() {
			self.fatal('timeout');
		},10000);
	},

	fatal: function(err,noretry) {
		if(!noretry && this.attempt < this.maxAttempts) {
			this.attempt++;
			this.start();
			return;
		}

		this.done({error: err.toString()});
	},
	initState: function() {
		return {
			name: '',
			map: '',
			password: false,
			
			raw: {},

			maxplayers: 0,
			players: [],
			bots: []
		};
	},
	finalizeState: function(state) {},

	finish: function(state) {
		this.finalizeState(state);
		this.done(state);
	},

	done: function(state) {
		if(this.finished) return;
		clearTimeout(this.globalTimeoutTimer);

		if(this.options.notes)
			state.notes = this.options.notes;

		state.query = {};
		if('host' in this.options) state.query.host = this.options.host;
		if('address' in this.options) state.query.address = this.options.address;
		if('port' in this.options) state.query.port = this.options.port;
		if('port_query' in this.options) state.query.port_query = this.options.port_query;
		state.query.type = this.type;
		if('pretty' in this) state.query.pretty = this.pretty;

		this.reset();
		this.finished = true;
		this.emit('finished',state);
		if(this.options.callback) this.options.callback(state);
	},

	reset: function() {
		if(this.timers) {
			this.timers.forEach(function(timer) {
				clearTimeout(timer);
			});
		}
		this.timers = [];
		
		if(this.tcpSocket) {
			this.tcpSocket.destroy();
			delete this.tcpSocket;
		}

		this.udpTimeoutTimer = false;
		this.udpCallback = false;
	},
	start: function() {
		var self = this;
		var options = self.options;
		this.reset();

		async.series([
			function(c) {
				// resolve host names
				if(!('host' in options)) return c();
				if(options.host.match(/\d+\.\d+\.\d+\.\d+/)) {
					options.address = options.host;
					c();
				} else {
					self.parseDns(options.host,c);
				}
			},
			function(c) {
				// calculate query port if needed
				if(!('port_query' in options) && 'port' in options) {
					var offset = options.port_query_offset || 0;
					options.port_query = options.port + offset;
				}
				c();
			},
			function(c) {
				// run
				self.run(self.initState());
			}

		]);
	},
	parseDns: function(host,c) {
		var self = this;
		
		function resolveStandard(host,c) {
			dns.lookup(host, function(err,address,family) {
				if(err) return self.fatal(err);
				self.options.address = address;
				c();
			});
		}
		function resolveSrv(srv,host,c) {
			dns.resolve(srv+'.'+host, 'SRV', function(err,addresses) {
				if(err) return resolveStandard(host,c);
				if(addresses.length >= 1) {
					var line = addresses[0];
					self.options.port = line.port;
					var srvhost = line.name;
					
					if(srvhost.match(/\d+\.\d+\.\d+\.\d+/)) {
						self.options.address = srvhost;
						c();
					} else {
						// resolve yet again
						resolveStandard(srvhost,c);
					}
					return;
				}
				return resolveStandard(host,c);
			});
		}

		if(this.srvRecord) resolveSrv(this.srvRecord,host,c);
		else resolveStandard(host,c);
	},

	// utils
	reader: function(buffer) {
		return new Reader(this,buffer);
	},
	translate: function(obj,trans) {
		for(var from in trans) {
			var to = trans[from];
			if(from in obj) {
				if(to) obj[to] = obj[from];
				delete obj[from];
			}
		}
	},
	setTimeout: function(c,t) {
		if(this.finished) return 0;
		var id = setTimeout(c,t);
		this.timers.push(id);
		return id;
	},

	
	
	trueTest: function(str) {
		if(typeof str == 'boolean') return str;
		if(typeof str == 'number') return str != 0;
		if(typeof str == 'string') {
			if(str.toLowerCase() == 'true') return true;
			if(str == 'yes') return true;
			if(str == '1') return true;
		}
		return false;
	},
	debugBuffer: function(buffer) {
		var out = '';
		var out2 = '';
		for(var i = 0; i < buffer.length; i++) {
			var sliced = buffer.slice(i,i+1);
			out += sliced.toString('hex')+' ';
			var chr = sliced.toString();
			if(chr < ' ' || chr > '~') chr = ' ';
			out2 += chr+'  ';
			if(out.length > 60) {
				console.log(out);
				console.log(out2);
				out = out2 = '';
			}
		}
		console.log(out);
		console.log(out2);
	},




	_tcpConnect: function(c) {
		var self = this;
		if(this.tcpSocket) return c(this.tcpSocket);

		var connected = false;
		var received = new Buffer(0);
		var address = this.options.address;
		var port = this.options.port_query;

		var socket = this.tcpSocket = net.connect(port,address,function() {
			if(self.debug) console.log(address+':'+port+" TCPCONNECTED");
			connected = true;
			c(socket);
		});
		socket.setTimeout(10000);
		socket.setNoDelay(true);
		if(this.debug) console.log(address+':'+port+" TCPCONNECT");
		
		var writeHook = socket.write;
		socket.write = function(data) {
			if(self.debug) console.log(address+':'+port+" TCP--> "+data.toString('hex'));
			writeHook.apply(this,arguments);
		}

		socket.on('error', function() {});
		socket.on('close', function() {
			if(!self.tcpCallback) return;
			if(connected) return self.fatal('Socket closed while waiting on TCP');
			else return self.fatal('TCP Connection Refused');
		});
		socket.on('data', function(data) {
			if(!self.tcpCallback) return;
			if(self.debug) console.log(address+':'+port+" <--TCP "+data.toString('hex'));
			received = Buffer.concat([received,data]);
			if(self.tcpCallback(received)) {
				clearTimeout(self.tcpTimeoutTimer);
				self.tcpCallback = false;
				received = new Buffer(0);
			}
		});
	},
	tcpSend: function(buffer,ondata) {
		var self = this;
		process.nextTick(function() {
			if(self.tcpCallback) return self.fatal('Attempted to send TCP packet while still waiting on a managed response');
			self._tcpConnect(function(socket) {
				socket.write(buffer);
			});
			if(!ondata) return;

			self.tcpTimeoutTimer = self.setTimeout(function() {
				self.tcpCallback = false;
				self.fatal('TCP Watchdog Timeout');
			},self.options.tcpTimeout);
			self.tcpCallback = ondata;
		});
	},



	udpSend: function(buffer,onpacket,ontimeout) {
		var self = this;
		process.nextTick(function() {
			if(self.udpCallback) return self.fatal('Attempted to send UDP packet while still waiting on a managed response');
			self._udpSendNow(buffer);
			if(!onpacket) return;

			self.udpTimeoutTimer = self.setTimeout(function() {
				self.udpCallback = false;
				var timeout = false;
				if(!ontimeout || ontimeout() !== true) timeout = true;
				if(timeout) self.fatal('UDP Watchdog Timeout');
			},self.options.udpTimeout);
			self.udpCallback = onpacket;
		});
	},
	_udpSendNow: function(buffer) {
		if(!('port_query' in this.options)) return this.fatal('Attempted to send without setting a port');
		if(!('address' in this.options)) return this.fatal('Attempted to send without setting an address');

		if(typeof buffer == 'string') buffer = new Buffer(buffer,'binary');
		
		if(this.debug) console.log(this.options.address+':'+this.options.port_query+" UDP--> "+buffer.toString('hex'));
		this.udpSocket.send(buffer,0,buffer.length,this.options.port_query,this.options.address);
	},
	_udpResponse: function(buffer) {
		if(this.udpCallback) {
			var result = this.udpCallback(buffer);
			if(result === true) {
				// we're done with this udp session
				clearTimeout(this.udpTimeoutTimer);
				this.udpCallback = false;
			}
		} else {
			this.udpResponse(buffer);
		}
	},
	udpResponse: function() {}
});