Bug fixes and stability improvements:

- Fix crash on improper websocket disconnect
- Fix some race conditions by moving to synchronized Queue and List
- Fix allowing invalid usernames

collab-vm-server-1.3/TurnQueue.cs

@@ -1,3 +1,4 @@
+using System.Collections.Concurrent;
 using System.Timers;
 using Timer = System.Timers.Timer;
 
@@ -9,7 +10,7 @@ public class TurnQueue
     public event EventHandler<TurnStatus> Turn;
     
     // Private fields
-    private readonly Queue<User> queue;
+    private readonly ConcurrentQueue<User> queue;
     private readonly uint turnTime;
     private readonly Timer timer;
     private uint currentTurnRemainingTime;
@@ -32,7 +33,8 @@ public class TurnQueue
         if (indefiniteTurn != null) return;
         if (queue.Count == 0) return; // This shouldn't happen, but just in case
         currentTurnRemainingTime--;
-        Utilities.Log(LogLevel.DEBUG, $"Turn tick, {currentTurnRemainingTime} seconds remaining on {queue.Peek().Username}'s turn");
+        if (!queue.TryPeek(out var u)) return;
+        Utilities.Log(LogLevel.DEBUG, $"Turn tick, {currentTurnRemainingTime} seconds remaining on {u.Username}'s turn");
         if (currentTurnRemainingTime == 0)
         {
             NextTurn();
@@ -48,10 +50,11 @@ public class TurnQueue
             SendTurnUpdate();
             return;
         }
-        queue.Dequeue();
+        queue.TryDequeue(out _);
         if (queue.Count > 0)
         {
-            Utilities.Log(LogLevel.DEBUG, $"It is now {queue.Peek().Username}'s turn");
+            if (!queue.TryPeek(out var u)) return;
+            Utilities.Log(LogLevel.DEBUG, $"It is now {u.Username}'s turn");
             currentTurnRemainingTime = turnTime;
         }
         SendTurnUpdate();
@@ -100,7 +103,8 @@ public class TurnQueue
         }
         if (!queue.Contains(user)) return;
         Utilities.Log(LogLevel.DEBUG, $"Removing user {user.Username} to turn queue");
-        if (queue.Peek() == user && indefiniteTurn == null)
+        if (!queue.TryPeek(out var _u)) return;
+        if (_u == user && indefiniteTurn == null)
         {
             NextTurn();
             return;
@@ -128,7 +132,8 @@ public class TurnQueue
     {
         if (indefiniteTurn != null) return indefiniteTurn;
         if (queue.Count == 0) return null;
-        return queue.Peek();
+        if (!queue.TryPeek(out var u)) return null;
+        return u;
     }
 
     public void GiveTurn(User user)
@@ -145,7 +150,8 @@ public class TurnQueue
             AddUser(user);
             return;
         }
-        if (queue.Peek() == user) return;
+        if (!queue.TryPeek(out var _u)) return;
+        if (_u == user) return;
         RemoveUser(user);
         var _queue = queue.ToArray();
         queue.Clear();

collab-vm-server-1.3/User.cs

@@ -79,8 +79,12 @@ public class User
         {
             return;
         }
+
+        try
+        {
             await socket.SendAsync(new ArraySegment<byte>(Encoding.UTF8.GetBytes(msg)), WebSocketMessageType.Text, true,
                 CancellationToken.None);
+        } catch { /* ignored */ }
     }
 
     private async Task ProcessMessage(string[] msgArr)
@@ -343,7 +347,7 @@ public class User
                     {
                         // Ban
                         if (_rank != Rank.Admin && (_rank != Rank.Moderator || !Program.Config.ModPermissions.Ban) || msgArr.Length < 3 || vm == null) return;
-                        var user = vm.Users.Find(u => u.Username == msgArr[2]);
+                        var user = vm.Users.First(u => u.Username == msgArr[2]);
                         if (user == null) return;
                         await user.Ban(msgArr.Length == 4 ? msgArr[3] : null);
                     }
@@ -366,7 +370,7 @@ public class User
                     {
                         // Mute
                         if (_rank != Rank.Admin && (_rank != Rank.Moderator || !Program.Config.ModPermissions.Mute) || msgArr.Length != 4 || vm == null) return;
-                        var user = vm.Users.Find(u => u.Username == msgArr[2]);
+                        var user = vm.Users.First(u => u.Username == msgArr[2]);
                         if (user == null) return;
                         bool? permanent = msgArr[3] == "1" ? true : msgArr[3] == "0" ? false : null;
                         if (permanent == null) return;
@@ -377,7 +381,7 @@ public class User
                     {
                         // Kick
                         if (_rank != Rank.Admin && (_rank != Rank.Moderator || !Program.Config.ModPermissions.Kick) || msgArr.Length != 3 || vm == null) return;
-                        var user = vm.Users.Find(u => u.Username == msgArr[2]);
+                        var user = vm.Users.First(u => u.Username == msgArr[2]);
                         if (user == null) return;
                         await user.Close();
                     }
@@ -386,7 +390,7 @@ public class User
                     {
                         // End turn
                         if (_rank != Rank.Admin && (_rank != Rank.Moderator || !Program.Config.ModPermissions.BypassTurn) || msgArr.Length != 3 || vm == null) return;
-                        var user = vm.Users.Find(u => u.Username == msgArr[2]);
+                        var user = vm.Users.First(u => u.Username == msgArr[2]);
                         if (user == null) return;
                         vm.TurnQueue.RemoveUser(user);
                     }
@@ -404,7 +408,7 @@ public class User
                     {
                         // Rename user
                         if (_rank != Rank.Admin && (_rank != Rank.Moderator || !Program.Config.ModPermissions.Rename) || msgArr.Length != 4 || vm == null) return;
-                        var user = vm.Users.Find(u => u.Username == msgArr[2]);
+                        var user = vm.Users.First(u => u.Username == msgArr[2]);
                         if (user == null) return;
                         await user.Rename(msgArr[3]);
                     }
@@ -413,7 +417,7 @@ public class User
                     {
                         // Get IP
                         if (_rank != Rank.Admin && (_rank != Rank.Moderator || !Program.Config.ModPermissions.GrabIP) || msgArr.Length != 3 || vm == null) return;
-                        var user = vm.Users.Find(u => u.Username == msgArr[2]);
+                        var user = vm.Users.First(u => u.Username == msgArr[2]);
                         if (user == null) return;
                         await SendAsync(Guacutils.Encode("admin", "19", msgArr[2], user.IP.ToString()));
                     }
@@ -496,8 +500,16 @@ public class User
         {
             using MemoryStream ms = new MemoryStream();
             do
+            {
+                try
                 {
                     result = await socket.ReceiveAsync(receivebuffer, token);
+                }
+                catch (WebSocketException ex)
+                {
+                    await Close(false);
+                    return;
+                }
                 if (result.MessageType == WebSocketMessageType.Close)
                 {
                     Disconnected.Invoke(this, new EventArgs());
@@ -546,9 +558,9 @@ public class User
     {
         await SendAsync(Guacutils.Encode("size", "0", size.Width.ToString(), size.Height.ToString()));
     }
-    public async Task Close()
+    public async Task Close(bool sendDisconnect = true)
     {
-        await SendAsync(Guacutils.Encode("disconnect"));
+        if (sendDisconnect) SendAsync(Guacutils.Encode("disconnect"));
         try
         {
             await socket.CloseAsync(WebSocketCloseStatus.NormalClosure, null, CancellationToken.None);
@@ -608,6 +620,7 @@ public class User
                 return;
             }
             await this.SendAsync(Guacutils.Encode("rename", "0", "2", _username, ((int)this._rank).ToString()));
+            return;
         }
         this._username = newname;
         if (oldname != null) this.Renamed.Invoke(this, oldname);

collab-vm-server-1.3/VM.cs

@@ -1,3 +1,5 @@
+using System.Collections;
+using System.Collections.Concurrent;
 using System.Net;
 using CollabVM.Server.Config;
 using SixLabors.ImageSharp;
@@ -14,7 +16,7 @@ public class VM
     // Public properties and events
     public VMController Controller { get; }
     public VMConfig Config { get; }
-    public List<User> Users { get; } = new();
+    public SynchronizedCollection<User> Users { get; } = new();
     public CircularBuffer.CircularBuffer<ChatMessage> ChatHistory { get; } = new((int)Program.Config.Chat.ChatHistoryLength);
     public TurnQueue TurnQueue { get; } = new(Program.Config.Turns.TurnTime);
     public ResetVote? Vote { get; private set; }

collab-vm-server-1.3/collab-vm-server-1.3.csproj

@@ -15,6 +15,7 @@
       <PackageReference Include="Samboy063.Tomlet" Version="5.2.0" />
       <PackageReference Include="SixLabors.ImageSharp" Version="3.1.1" />
       <PackageReference Include="Swashbuckle.AspNetCore" Version="6.5.0" />
+      <PackageReference Include="System.ServiceModel.Primitives" Version="8.0.0" />
     </ItemGroup>
 
     <ItemGroup>