first commit

NitroxServer/Communication/LANBroadcastServer.cs

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+using System.Net;
+using System.Threading;
+using LiteNetLib;
+using LiteNetLib.Utils;
+using NitroxModel.Constants;
+
+namespace NitroxServer.Communication;
+
+public static class LANBroadcastServer
+{
+    private static NetManager server;
+    private static EventBasedNetListener listener;
+    private static Timer pollTimer;
+
+    public static void Start(CancellationToken ct)
+    {
+        listener = new EventBasedNetListener();
+        listener.NetworkReceiveUnconnectedEvent += NetworkReceiveUnconnected;
+        server = new NetManager(listener);
+        server.AutoRecycle = true;
+        server.BroadcastReceiveEnabled = true;
+        server.UnconnectedMessagesEnabled = true;
+
+        foreach (int port in LANDiscoveryConstants.BROADCAST_PORTS)
+        {
+            if (server.Start(port))
+            {
+                break;
+            }
+        }
+
+        pollTimer = new Timer(_ => server.PollEvents());
+        pollTimer.Change(0, 100);
+        Log.Debug($"{nameof(LANBroadcastServer)} started");
+    }
+
+    public static void Stop()
+    {
+        listener?.ClearNetworkReceiveUnconnectedEvent();
+        server?.Stop();
+        pollTimer?.Dispose();
+        Log.Debug($"{nameof(LANBroadcastServer)} stopped");
+    }
+
+    private static void NetworkReceiveUnconnected(IPEndPoint remoteEndPoint, NetPacketReader reader, UnconnectedMessageType messageType)
+    {
+        if (messageType == UnconnectedMessageType.Broadcast)
+        {
+            string requestString = reader.GetString();
+            if (requestString == LANDiscoveryConstants.BROADCAST_REQUEST_STRING)
+            {
+                NetDataWriter writer = new();
+                writer.Put(LANDiscoveryConstants.BROADCAST_RESPONSE_STRING);
+                writer.Put(Server.Instance.Port);
+
+                server.SendBroadcast(writer, remoteEndPoint.Port);
+            }
+        }
+    }
+}