Add masterserver.downloadServerList function

lib/masterserver.js

@@ -0,0 +1,55 @@
+var net = require("net");
+var _ = require("underscore");
+var constants = require("./constants");
+
+function defaultOptions(){
+  return {
+    hostname: "sauerbraten.org",
+    port: constants.MASTERSERVER_PORT
+  };
+}
+
+function downloadServerList(options){
+
+  options = _.extend(defaultOptions(), {callback:function(){}}, options);
+
+  var socket = new net.Socket();
+  var buffer = "";
+
+  socket.setEncoding("ascii");
+
+  socket.on("connect", function(){
+    socket.write("list\n");
+  });
+
+  socket.on("error", function(exception){
+    options.callback(null, exception);
+  });
+
+  socket.on("data", function(data){
+    buffer += data;
+  });
+
+  socket.on("end", function(){
+
+    var servers = [];
+    var lines = buffer.split("\n");
+
+    for(var i = 0; i < lines.length; i++){
+      var args = lines[i].split(" ");
+      if(args.length >= 3){
+        var ip = args[1];
+        var port = parseInt(args[2], 10);
+        servers.push([ip, port]);
+      }
+    }
+
+    options.callback(servers);
+  });
+
+  socket.connect(options.port, options.hostname);
+}
+
+module.exports = {
+  downloadServerList: downloadServerList
+};