feat(chat): (2) add server-side rate limiting

GenOnlineService/Constants.cs

@@ -658,6 +658,30 @@ public static List<UserSession> GetAllDataFromUser(Int64 userID)
 			return lstRet;
 		}
 
+		public static async Task DisconnectUser(Int64 userID, byte[] finalMessage)
+		{
+			List<UserSession> userSessions = GetAllDataFromUser(userID);
+
+			foreach (UserSession userSession in userSessions)
+			{
+				try
+				{
+					UserWebSocketInstance? oldWS = GetWebSocketForSession(userSession);
+					if (oldWS != null)
+					{
+						await oldWS.SendAsync(finalMessage, WebSocketMessageType.Text);
+					}
+
+					await DeleteSession(userID, userSession.GetSessionType(), oldWS, true);
+				}
+				catch (Exception ex)
+				{
+					Console.WriteLine($"[ERROR] DisconnectUser failed for user {userID}, session {userSession.GetSessionType()}: {ex.Message}");
+					SentrySdk.CaptureException(ex);
+				}
+			}
+		}
+
 		public static async Task<bool> ClearDataFromUser(Int64 userID, EUserSessionType sessionType)
 		{
 			// NOTE: This is when a player is truly disconnected and we can destroy session, remove form lobby etc, websocket disconnect doesnt mean that because the clietn reconnects
@@ -819,9 +843,11 @@ public static async Task MarkRoomMemberListAsDirty(int roomID)
 	}
 
 	// NOTE: only one instance for ALL websockets/sessions, and is destroyed when the last one of the former is destroyed
-	public class SharedUserData
-	{
-		private int m_RefCount = 0;
+	public class SharedUserData
+	{
+		private int m_RefCount = 0;
+		private readonly Queue<Int64> m_chatMessageTimestamps = new();
+		private Int64? m_lastChatRateLimitNoticeTimestamp;
 
 		public void IncrementRefCount()
 		{
@@ -849,7 +875,49 @@ public bool NeedsGC()
 
 		public UserSocialContainer GetSocialContainer() { return m_socialContainer; }
 
-		public bool IsAdmin() { return m_bIsAdmin; }
+		public bool IsAdmin() { return m_bIsAdmin; }
+
+		public bool TryConsumeChatMessage()
+		{
+			const int maxMessages = 3;
+			const Int64 windowMilliseconds = 9000;
+			Int64 now = Environment.TickCount64;
+
+			lock (m_chatMessageTimestamps)
+			{
+				while (m_chatMessageTimestamps.TryPeek(out Int64 timestamp)
+					&& now - timestamp >= windowMilliseconds)
+				{
+					m_chatMessageTimestamps.Dequeue();
+				}
+
+				if (m_chatMessageTimestamps.Count >= maxMessages)
+				{
+					return false;
+				}
+
+				m_chatMessageTimestamps.Enqueue(now);
+				return true;
+			}
+		}
+
+		public bool TryConsumeChatRateLimitNotice()
+		{
+			const Int64 intervalMilliseconds = 9000;
+			Int64 now = Environment.TickCount64;
+
+			lock (m_chatMessageTimestamps)
+			{
+				if (m_lastChatRateLimitNoticeTimestamp.HasValue
+					&& now - m_lastChatRateLimitNoticeTimestamp.Value < intervalMilliseconds)
+				{
+					return false;
+				}
+
+				m_lastChatRateLimitNoticeTimestamp = now;
+				return true;
+			}
+		}
 
 		public SharedUserData(Int64 ownerID, UserSocialContainer socialContainer, string strDisplayName, bool bIsAdmin, PlayerStats userStats)
 		{
@@ -2545,7 +2613,10 @@ public enum EWebSocketMessageID
 		AC_REGISTER_PLAYER = 40,
 		AC_DEREGISTER_PLAYER = 41,
 		WS_KEEPALIVE = 42,
-		WS_KEEPALIVE_CLIENT = 43
+		WS_KEEPALIVE_CLIENT = 43,
+		MODERATION_NOTICE = 46,
+		MODERATION_COMMAND = 47,
+		MODERATION_COMMAND_RESULT = 48
 	};
 
 	public static class UserPresence
@@ -2643,6 +2714,34 @@ public class WebSocketMessage_StartMatch : WebSocketMessage
 		public string screenshot_url { get; set; } = String.Empty;
 	}
 
+	public class WebSocketMessage_ModerationNotice : WebSocketMessage
+	{
+		public string action_type { get; set; } = String.Empty;
+		public string reason { get; set; } = String.Empty;
+
+		[System.Text.Json.Serialization.JsonIgnore(Condition = System.Text.Json.Serialization.JsonIgnoreCondition.WhenWritingNull)]
+		public string? scope_type { get; set; }
+	}
+
+	public sealed class WebSocketMessage_ModerationCommand : WebSocketMessage
+	{
+		public UInt64 request_id { get; set; }
+		public string action_type { get; set; } = String.Empty;
+		public Int64? target_user_id { get; set; }
+		public string reason { get; set; } = String.Empty;
+	}
+
+	public sealed class WebSocketMessage_ModerationCommandResult : WebSocketMessage
+	{
+		public UInt64 request_id { get; set; }
+		public bool success { get; set; }
+
+		[System.Text.Json.Serialization.JsonIgnore(Condition = System.Text.Json.Serialization.JsonIgnoreCondition.WhenWritingNull)]
+		public string? error_code { get; set; }
+
+		public string message { get; set; } = String.Empty;
+	}
+
 	public abstract class WebSocketMessage
 	{
 		public int msg_id { get; set; }
@@ -2829,4 +2928,4 @@ public class WebSocketMessage_MatchmakerStartGame : WebSocketMessage
 
 	}
 
-}
+}

GenOnlineService/Controllers/CheckLogin/CheckLoginController.cs

@@ -41,6 +41,7 @@ public override Type GetReturnType()
 		public string refresh_token { get; set; } = "";
 		public Int64 user_id { get; set; } = -1;
 		public string display_name { get; set; } = "";
+		public string ban_reason { get; set; } = "";
 
 		public string ws_uri { get; set; } = "";
 	}
@@ -176,12 +177,14 @@ public async Task<APIResult> Post_InternalHandler(string jsonData, string ipAddr
 										Int64 user_id = loginEntry.user_id;
 
 										// ban check
-										bool bIsBanned = await Database.Users.IsUserBanned(db, user_id);
-										if (bIsBanned)
+										UserBanStatus? banStatus = await Database.Users.GetUserBanStatus(db, user_id);
+										if (banStatus?.IsBanned == true)
 										{
 											await TokenRevocationManager.RevokeAllTokensForUser(user_id, "user is banned");
+											await ModerationManager.DisconnectUser(user_id, EModerationAction.Ban, banStatus.BanReason);
 
 											result.result = EPendingLoginState.LoginFailed;
+											result.ban_reason = banStatus.BanReason;
 											Response.StatusCode = (int)HttpStatusCode.Locked;
 											return result;
 										}

GenOnlineService/Controllers/LoginWithToken/LoginWithTokenController.cs

@@ -41,6 +41,7 @@ public override Type GetReturnType()
 		public string refresh_token { get; set; } = "";
 		public Int64 user_id { get; set; } = -1;
 		public string display_name { get; set; } = "";
+		public string ban_reason { get; set; } = "";
 
 		public string ws_uri { get; set; } = "";
 	}
@@ -129,13 +130,15 @@ public async Task<APIResult> Post_InternalHandler(string jsonData, string ipAddr
 						}
 
 						// ban check
-						bool bIsBanned = await Database.Users.IsUserBanned(db, user_id);
-						if (bIsBanned)
+						UserBanStatus? banStatus = await Database.Users.GetUserBanStatus(db, user_id);
+						if (banStatus?.IsBanned == true)
 						{
 							// kill every token they hold, not just this request
 							await TokenRevocationManager.RevokeAllTokensForUser(user_id, "user is banned");
+							await ModerationManager.DisconnectUser(user_id, EModerationAction.Ban, banStatus.BanReason);
 
 							result.result = EPendingLoginState.LoginFailed;
+							result.ban_reason = banStatus.BanReason;
 							Response.StatusCode = (int)HttpStatusCode.Locked;
 							return result;
 						}

GenOnlineService/Controllers/RefreshToken/RefreshTokenController.cs

@@ -35,6 +35,7 @@ public override Type GetReturnType()
 		public string refresh_token { get; set; } = "";
 		public Int64 user_id { get; set; } = -1;
 		public string display_name { get; set; } = "";
+		public string ban_reason { get; set; } = "";
 	}
 
 	// Pure token rotation. Unlike LoginWithToken this does NOT establish a session - the caller's
@@ -97,13 +98,15 @@ public async Task<APIResult> Post_InternalHandler(string ipAddr)
 
 				// re-check the ban on every rotation so a ban applied since the last refresh takes
 				// effect immediately rather than waiting for the periodic reconcile
-				bool bIsBanned = await Database.Users.IsUserBanned(db, user_id);
-				if (bIsBanned)
+				UserBanStatus? banStatus = await Database.Users.GetUserBanStatus(db, user_id);
+				if (banStatus?.IsBanned == true)
 				{
 					// kill every token they hold, not just this request
 					await TokenRevocationManager.RevokeAllTokensForUser(user_id, "user is banned");
+					await ModerationManager.DisconnectUser(user_id, EModerationAction.Ban, banStatus.BanReason);
 
 					result.result = EPendingLoginState.LoginFailed;
+					result.ban_reason = banStatus.BanReason;
 					Response.StatusCode = (int)HttpStatusCode.Locked;
 					return result;
 				}

GenOnlineService/Controllers/WebSocket/WebSocketController.cs

@@ -41,11 +41,28 @@ public WebSocketController(LobbyManager lobbyManager, IDbContextFactory<AppDbCon
 			_dbFactory = dbFactory;
 		}
 
-		private static readonly JsonSerializerOptions JsonOpts = new()
+		private static readonly JsonSerializerOptions JsonOpts = new()
 		{
 			PropertyNameCaseInsensitive = true,
 			AllowOutOfOrderMetadataProperties = true
-		};
+		};
+
+		private static void QueueChatRateLimited(UserSession session, SharedUserData userData, string scopeType)
+		{
+			if (!userData.TryConsumeChatRateLimitNotice())
+			{
+				return;
+			}
+
+			WebSocketMessage_ModerationNotice message = new()
+			{
+				msg_id = (int)EWebSocketMessageID.MODERATION_NOTICE,
+				action_type = "rate_limit",
+				reason = "Rate limit: Please wait before sending another message.",
+				scope_type = scopeType
+			};
+			session.QueueWebsocketSend(Encoding.UTF8.GetBytes(JsonSerializer.Serialize(message)));
+		}
 
 		// GeoIP DB is designed to be reused; opening per request is expensive.
 		// It is gitignored and absent in fresh clones, so a failure to open must
@@ -375,9 +392,25 @@ private async Task ProcessWSMessage(UserWebSocketInstance sourceWS, UserSession
 					WebSocketMessage_Social_FriendChatMessage_Inbound? chatMessage =
 						JsonSerializer.Deserialize<WebSocketMessage_Social_FriendChatMessage_Inbound>(payload, JsonOpts);
 
-					if (chatMessage != null)
-					{
-						// must be online & friends
+					if (chatMessage != null)
+					{
+						if (!sourceUserData.TryConsumeChatMessage())
+						{
+							if (sourceUserData.TryConsumeChatRateLimitNotice())
+							{
+								WebSocketMessage_Social_FriendChatMessage_Outbound rateLimitMessage = new()
+								{
+									msg_id = (int)EWebSocketMessageID.SOCIAL_FRIEND_CHAT_MESSAGE_SERVER_TO_CLIENT,
+									source_user_id = sourceUserSession.m_UserID,
+									target_user_id = chatMessage.target_user_id,
+									message = "Rate limit: Please wait before sending another message."
+								};
+								sourceUserSession.QueueWebsocketSend(Encoding.UTF8.GetBytes(JsonSerializer.Serialize(rateLimitMessage)));
+							}
+							return;
+						}
+
+						// must be online & friends
 
 						SharedUserData? targetUserData = WebSocketManager.GetSharedDataForUser(chatMessage.target_user_id);
 
@@ -426,9 +459,15 @@ private async Task ProcessWSMessage(UserWebSocketInstance sourceWS, UserSession
 					WebSocketMessage_NetworkRoomChatMessageInbound? chatMessage =
 						JsonSerializer.Deserialize<WebSocketMessage_NetworkRoomChatMessageInbound>(payload, JsonOpts);
 
-					if (chatMessage != null)
-					{
-						// response
+					if (chatMessage != null)
+					{
+						if (!sourceUserData.TryConsumeChatMessage())
+						{
+							QueueChatRateLimited(sourceUserSession, sourceUserData, "room");
+							return;
+						}
+
+						// response
 						WebSocketMessage_NetworkRoomChatMessageOutbound outboundMsg = new WebSocketMessage_NetworkRoomChatMessageOutbound();
 						outboundMsg.msg_id = (int)EWebSocketMessageID.NETWORK_ROOM_CHAT_FROM_SERVER;
 
@@ -442,7 +481,7 @@ private async Task ProcessWSMessage(UserWebSocketInstance sourceWS, UserSession
 						{
 							if (sourceUserData.IsAdmin())
 							{
-								outboundMsg.message = String.Format("[\u2605\u2605GO STAFF\u2605\u2605]    [{0}] {1}", sourceUserData.m_strDisplayName, chatMessage.message);
+								outboundMsg.message = String.Format("[\u2605\u2605GO STAFF\u2605\u2605] [{0}] {1}", sourceUserData.m_strDisplayName, chatMessage.message);
 								outboundMsg.admin = true;
 								outboundMsg.name_change = false;
 							}
@@ -703,9 +742,15 @@ private async Task ProcessWSMessage(UserWebSocketInstance sourceWS, UserSession
 					WebSocketMessage_LobbyChatMessageInbound? chatMessage =
 						JsonSerializer.Deserialize<WebSocketMessage_LobbyChatMessageInbound>(payload, JsonOpts);
 
-					if (chatMessage != null)
-					{
-						// get lobby
+					if (chatMessage != null)
+					{
+						if (!sourceUserData.TryConsumeChatMessage())
+						{
+							QueueChatRateLimited(sourceUserSession, sourceUserData, "lobby");
+							return;
+						}
+
+						// get lobby
 						Lobby? playerLobby = _lobbyManager.GetLobby(sourceUserSession.currentLobbyID);
 
 						if (playerLobby != null)

GenOnlineService/Database/Database.User.cs

@@ -98,6 +98,12 @@ public class UserLobbyPreferences
 	public bool favorite_limit_superweapons = false;
 }
 
+public sealed class UserBanStatus
+{
+	public bool IsBanned { get; set; }
+	public string BanReason { get; set; } = String.Empty;
+}
+
 // TODO_EFCORE: add index for code
 public class PendingLoginConfiguration : IEntityTypeConfiguration<PendingLogin>
 {
@@ -279,6 +285,18 @@ public static class Users
 				  .Select(u => u.IsBanned)
 				  .FirstOrDefault());
 
+		private static readonly Func<AppDbContext, long, Task<UserBanStatus?>> _getUserBanStatusQuery =
+			EF.CompileAsyncQuery((AppDbContext db, long userId) =>
+				db.Users
+				  .AsNoTracking()
+				  .Where(u => u.ID == userId)
+				  .Select(u => new UserBanStatus
+				  {
+					  IsBanned = u.IsBanned,
+					  BanReason = u.BanReason ?? String.Empty
+				  })
+				  .FirstOrDefault());
+
 		private static readonly Func<AppDbContext, long, Task<string?>> _getDisplayNameQuery =
 				EF.CompileAsyncQuery((AppDbContext db, long userId) =>
 					db.Users
@@ -446,6 +464,20 @@ public static async Task<bool> IsUserBanned(AppDbContext db, long userId)
 			}
 		}
 
+		public static async Task<UserBanStatus?> GetUserBanStatus(AppDbContext db, long userId)
+		{
+			try
+			{
+				return await _getUserBanStatusQuery(db, userId);
+			}
+			catch (Exception ex)
+			{
+				Console.WriteLine($"[ERROR] GetUserBanStatus failed: {ex.Message}");
+				SentrySdk.CaptureException(ex);
+				return null;
+			}
+		}
+
 
 		public static async Task<string> GetDisplayName(AppDbContext db, long userId)
 		{