First commit, most of the backend system! :)

lib/ping.js

@@ -0,0 +1,96 @@
+var mcpc = require('./mcpc_buffer');
+var net = require('net');
+
+function pingMinecraftPC(host, port, timeout, callback) {
+	var client = new net.Socket();
+	var milliseconds = (new Date).getTime();
+
+	client.connect(port, host, function() {
+		// Write out handshake packet.
+		var handshakeBuffer = mcpc.createBuffer();
+
+		handshakeBuffer.writeVarInt(0);
+		handshakeBuffer.writeVarInt(47);
+		handshakeBuffer.writeString(host);
+		handshakeBuffer.writeUShort(port);
+		handshakeBuffer.writeVarInt(1);
+
+		writePCBuffer(client, handshakeBuffer);
+
+		// Write the set connection state packet, we should get the MOTD after this.
+		var setModeBuffer = mcpc.createBuffer();
+
+		setModeBuffer.writeVarInt(0);
+
+		writePCBuffer(client, setModeBuffer);
+	});
+
+	var readingBuffer = new Buffer(0);
+
+    client.on('data', function(data) {
+        readingBuffer = Buffer.concat([readingBuffer, data]);
+
+        var buffer = mcpc.createBuffer(readingBuffer);
+        var length;
+
+        try {
+            length = buffer.readVarInt();
+        } catch(err) {
+        	// The buffer isn't long enough yet, wait for more data!
+            return;
+        }
+
+        // Make sure we have the data we need!
+        if (readingBuffer.length < length - buffer.offset() ) {
+            return;
+        }
+
+        // Read the packet ID, throw it away.
+        buffer.readVarInt();
+
+        try {
+            var json = JSON.parse(buffer.readString());
+
+            json.latency = (new Date).getTime() - milliseconds;
+
+            // We parsed it, send it along!
+            callback(null, json);
+        } catch (err) {
+        	// Our data is corrupt? Fail hard.
+        	callback(err, null);
+
+            return;
+        }
+
+        // We're done here.
+        client.destroy();
+    });
+
+	client.on('error', function(err) {
+		callback(err, null);
+	});
+
+	// Make sure we don't go overtime.
+	setTimeout(function() {
+		client.end();
+	}, timeout);
+}
+
+// Wraps our Buffer into another to fit the Minecraft protocol.
+function writePCBuffer(client, buffer) {
+	var length = mcpc.createBuffer();
+
+	length.writeVarInt(buffer.buffer().length);
+
+	client.write(Buffer.concat([length.buffer(), buffer.buffer()]));
+}
+
+exports.ping = function(host, port, type, timeout, callback) {
+	if (type === 'PC') {
+		pingMinecraftPC(host, port, timeout, callback);
+	} else if (type === 'PE') {
+
+	} else {
+		throw new Error('Unsupported type: ' + type);
+	}
+};