feat: add server discovery

XIVChatPlugin/Configuration.cs

@@ -15,6 +15,8 @@ namespace XIVChatPlugin {
 
         public bool SendBattle { get; set; } = true;
 
+        public bool PairingMode { get; set; } = true;
+
         public Dictionary<Guid, Tuple<string, byte[]>> TrustedKeys { get; set; } = new Dictionary<Guid, Tuple<string, byte[]>>();
         public KeyPair KeyPair { get; set; } = null;
 

XIVChatPlugin/PluginUI.cs

@@ -73,6 +73,17 @@ namespace XIVChatPlugin {
 
         private static void TextWhite(string text) => WithWhiteText(() => ImGui.TextUnformatted(text));
 
+        private static void HelpMarker(string text) {
+            ImGui.TextDisabled("(?)");
+            if (ImGui.IsItemHovered()) {
+                ImGui.BeginTooltip();
+                ImGui.PushTextWrapPos(ImGui.GetFontSize() * 20f);
+                ImGui.TextUnformatted(text);
+                ImGui.PopTextWrapPos();
+                ImGui.EndTooltip();
+            }
+        }
+
         private void DrawInner() {
             this.AcceptPending();
 
@@ -129,6 +140,16 @@ namespace XIVChatPlugin {
                 }
 
                 ImGui.TextUnformatted("Changing this setting will not affect messages already in the backlog.");
+
+                ImGui.Spacing();
+
+                bool pairingMode = this.plugin.Config.PairingMode;
+                if (WithWhiteText(() => ImGui.Checkbox("Pairing mode", ref pairingMode))) {
+                    this.plugin.Config.PairingMode = pairingMode;
+                    this.plugin.Config.Save();
+                }
+                ImGui.SameLine();
+                HelpMarker("While in pairing mode, XIVChat Server will listen for information requests from clients broadcast on your local network and respond with information about the server. This will make it easier to add your server to a client, but this should be turned off when not actively adding new devices.");
             }
 
             if (WithWhiteText(() => ImGui.CollapsingHeader("Trusted keys"))) {

XIVChatPlugin/Server.cs

@@ -41,7 +41,7 @@ namespace XIVChatPlugin {
         private bool sendPlayerData = false;
 
         private volatile bool _running = false;
-        public bool Running { get => this._running; set => this._running = value; }
+        public bool Running => this._running;
 
         private InputChannel currentChannel = InputChannel.Say;
 
@@ -56,6 +56,82 @@ namespace XIVChatPlugin {
             this.plugin.Functions.ReceiveFriendList += this.OnReceiveFriendList;
         }
 
+        private void SpawnPairingModeTask() {
+            Task.Run(async () => {
+                // delay for 10 seconds because of the jank way we cancel below to prevent port bind issues
+                await Task.Delay(10_000);
+
+                const int multicastPort = 17444;
+                using var udp = new UdpClient(new IPEndPoint(IPAddress.Any, multicastPort));
+
+                var multicastAddr = IPAddress.Parse("224.0.0.147");
+                var endpoint = new IPEndPoint(multicastAddr, multicastPort);
+                udp.JoinMulticastGroup(multicastAddr);
+
+                string lastPlayerName = null;
+
+                Task<UdpReceiveResult> receiveTask = null;
+
+                while (this.Running) {
+                    if (!this.plugin.Config.PairingMode) {
+                        await Task.Delay(5_000);
+                        continue;
+                    }
+
+                    var playerName = this.plugin.Interface.ClientState.LocalPlayer?.Name;
+
+                    if (playerName != null) {
+                        lastPlayerName = playerName;
+                    }
+
+                    if (lastPlayerName == null) {
+                        await Task.Delay(5_000);
+                        continue;
+                    }
+
+                    if (receiveTask == null) {
+                        receiveTask = udp.ReceiveAsync();
+                    }
+
+                    var result = await Task.WhenAny(
+                        receiveTask,
+                        Task.Delay(1_500)
+                    );
+
+                    if (result != receiveTask) {
+                        if (!this.Running) {
+                            udp.Close();
+                        }
+
+                        continue;
+                    }
+
+                    var recv = await receiveTask;
+                    receiveTask = null;
+
+                    var data = recv.Buffer;
+                    if (data.Length != 1 || data[0] != 14) {
+                        continue;
+                    }
+
+                    var utf8 = Encoding.UTF8.GetBytes(lastPlayerName);
+                    var portBytes = BitConverter.GetBytes(this.plugin.Config.Port).Reverse().ToArray();
+                    var key = this.plugin.Config.KeyPair.PublicKey;
+                    // magic + string length + string + port + key
+                    var payload = new byte[1 + 1 + utf8.Length + portBytes.Length + key.Length]; // assuming names can only be 32 bytes here
+                    payload[0] = 14;
+                    payload[1] = (byte)utf8.Length;
+                    Array.Copy(utf8, 0, payload, 2, utf8.Length);
+                    Array.Copy(portBytes, 0, payload, 2 + utf8.Length, portBytes.Length);
+                    Array.Copy(key, 0, payload, 2 + utf8.Length + portBytes.Length, key.Length);
+
+                    await udp.SendAsync(payload, payload.Length, recv.RemoteEndPoint);
+                }
+
+                PluginLog.Log("Scan response thread done");
+            });
+        }
+
         private async void OnReceiveFriendList(List<Player> friends) {
             var msg = new ServerPlayerList {
                 Type = PlayerListType.Friend,
@@ -78,15 +154,15 @@ namespace XIVChatPlugin {
         }
 
         public void Spawn() {
-            var ip = IPAddress.Parse("0.0.0.0");
             var port = this.plugin.Config.Port;
 
             Task.Run(async () => {
-                this.listener = new TcpListener(ip, port);
+                this.listener = new TcpListener(IPAddress.Any, port);
                 this.listener.Start();
 
                 this._running = true;
                 PluginLog.Log("Running...");
+                this.SpawnPairingModeTask();
                 while (!this.tokenSource.IsCancellationRequested) {
                     var conn = await this.listener.GetTcpClient(this.tokenSource);
                     this.SpawnClientTask(conn);