Nat introduction added; sample added (not finished yet)

Samples/MasterServerSample/MasterServer/Program.cs

@@ -0,0 +1,81 @@
+using System;
+using System.Collections.Generic;
+using Lidgren.Network;
+using System.Net;
+
+namespace MasterServer
+{
+	public enum MasterServerMessageType
+	{
+		RegisterHost,
+		RequestHostList,
+		RequestIntroduction,
+	}
+
+	public class Program
+	{
+		static void Main(string[] args)
+		{
+			List<IPEndPoint> registeredHosts = new List<IPEndPoint>();
+
+			NetPeerConfiguration config = new NetPeerConfiguration("masterserver");
+
+			NetPeer peer = new NetPeer(config);
+			peer.Start();
+
+			// keep going until ESCAPE is pressed
+			Console.WriteLine("Press ESC to quit");
+			while (!Console.KeyAvailable || Console.ReadKey().Key != ConsoleKey.Escape)
+			{
+				NetIncomingMessage msg;
+				while((msg = peer.ReadMessage()) != null)
+				{
+					switch (msg.MessageType)
+					{
+						case NetIncomingMessageType.UnconnectedData:
+							//
+							// We've received a message from a client or a host
+							//
+
+							// by design, the first byte always indicates action
+							switch ((MasterServerMessageType)msg.ReadByte())
+							{
+								case MasterServerMessageType.RegisterHost:
+									// It's a host wanting to register its presence
+									registeredHosts.Add(msg.SenderEndpoint);
+									break;
+
+								case MasterServerMessageType.RequestHostList:
+									// It's a client wanting a list of registered hosts
+									foreach (IPEndPoint ep in registeredHosts)
+									{
+										// send registered host to client
+										NetOutgoingMessage om = peer.CreateMessage();
+										om.Write(ep);
+										peer.SendUnconnectedMessage(om, msg.SenderEndpoint);
+									}
+
+									break;
+								case MasterServerMessageType.RequestIntroduction:
+									// It's a client wanting to connect to a specific host
+									IPEndPoint rh = msg.ReadIPEndpoint();
+									peer.Introduce(rh, msg.SenderEndpoint);
+									break;
+							}
+							break;
+
+						case NetIncomingMessageType.DebugMessage:
+						case NetIncomingMessageType.VerboseDebugMessage:
+						case NetIncomingMessageType.WarningMessage:
+						case NetIncomingMessageType.ErrorMessage:
+							// print diagnostics message
+							Console.WriteLine(msg.ReadString());
+							break;
+					}
+				}
+			}
+
+			peer.Shutdown("shutting down");
+		}
+	}
+}