Clients send the latest received campaign ID to the server when in the lobby instead of requesting it once with a reliable message. -> Now the server reattempts sending the save file if the transfer fails at either end.

Barotrauma/BarotraumaClient/Source/Networking/FileTransfer/FileReceiver.cs

@@ -1,4 +1,5 @@
 using Lidgren.Network;
+using Microsoft.Xna.Framework;
 using System;
 using System.Collections.Generic;
 using System.IO;
@@ -86,10 +87,13 @@ namespace Barotrauma.Networking
 
                 Connection = connection;               
 
+                Status = FileTransferStatus.NotStarted;
+            }
+
+            public void OpenStream()
+            {
                 WriteStream = new FileStream(FilePath, FileMode.Create, FileAccess.Write, FileShare.None);
                 TimeStarted = Environment.TickCount;
-
-                Status = FileTransferStatus.NotStarted;
             }
 
             public void ReadBytes(NetIncomingMessage inc)
@@ -103,7 +107,7 @@ namespace Barotrauma.Networking
 
                 if (GameSettings.VerboseLogging)
                 {
-                    DebugConsole.Log("Received "+all.Length+" bytes of the file "+FileName+" ("+Received+"/"+FileSize+" received)");
+                    DebugConsole.Log("Received " + all.Length + " bytes of the file " + FileName + " (" + Received + "/" + FileSize + " received)");
                 }
 
                 BytesPerSecond = Received / psec;
@@ -137,8 +141,9 @@ namespace Barotrauma.Networking
 
         const int MaxFileSize = 1000000;
         
-        public delegate void OnFinishedDelegate(FileTransferIn fileStreamReceiver);
+        public delegate void TransferInDelegate(FileTransferIn fileStreamReceiver);
-        public OnFinishedDelegate OnFinished;
+        public TransferInDelegate OnFinished;
+        public TransferInDelegate OnTransferFailed;
 
         private List<FileTransferIn> activeTransfers;
 
@@ -223,11 +228,25 @@ namespace Barotrauma.Networking
                         }
                     }
 
-                    var newTransfer = new FileTransferIn(inc.SenderConnection, Path.Combine(downloadFolder, fileName), (FileTransferType)fileType);
+                    FileTransferIn newTransfer = new FileTransferIn(inc.SenderConnection, Path.Combine(downloadFolder, fileName), (FileTransferType)fileType);
                     newTransfer.SequenceChannel = inc.SequenceChannel;
                     newTransfer.Status = FileTransferStatus.Receiving;
                     newTransfer.FileSize = fileSize;
 
+                    try
+                    {
+                        newTransfer.OpenStream();
+                    }
+                    catch (IOException e)
+                    {
+                        GameMain.Client.CancelFileTransfer(inc.SequenceChannel);
+                        DebugConsole.NewMessage("Failed to initiate a file transfer {" + e.Message + "}", Color.Red);
+
+                        newTransfer.Status = FileTransferStatus.Error;
+                        OnTransferFailed(newTransfer);
+                        return;
+                    }
+
                     activeTransfers.Add(newTransfer);
 
                     break;
@@ -240,7 +259,7 @@ namespace Barotrauma.Networking
                         return;
                     }
 
-                    if (activeTransfer.Received + (ulong)(inc.LengthBytes-inc.PositionInBytes) > activeTransfer.FileSize)
+                    if (activeTransfer.Received + (ulong)(inc.LengthBytes - inc.PositionInBytes) > activeTransfer.FileSize)
                     {
                         GameMain.Client.CancelFileTransfer(inc.SequenceChannel);
                         DebugConsole.ThrowError("File transfer error: Received more data than expected");
@@ -256,7 +275,7 @@ namespace Barotrauma.Networking
                     catch (Exception e)
                     {
                         GameMain.Client.CancelFileTransfer(inc.SequenceChannel);
-                        DebugConsole.ThrowError("File transfer error: "+e.Message);
+                        DebugConsole.ThrowError("File transfer error: " + e.Message);
                         activeTransfer.Status = FileTransferStatus.Error;
                         StopTransfer(activeTransfer, true);
                         return;

Barotrauma/BarotraumaClient/Source/Networking/GameClient.cs

@@ -990,7 +990,15 @@ namespace Barotrauma.Networking
             outmsg.Write(ChatMessage.LastID);
 
             var campaign = GameMain.GameSession?.GameMode as MultiplayerCampaign;
-            outmsg.Write(campaign == null ? 0 : campaign.LastUpdateID);
+            if (campaign == null || campaign.LastSaveID == 0)
+            {
+                outmsg.Write((UInt16)0);
+            }
+            else
+            {
+                outmsg.Write(campaign.LastSaveID);
+                outmsg.Write(campaign.LastUpdateID);
+            }
 
             chatMsgQueue.RemoveAll(cMsg => !NetIdUtils.IdMoreRecent(cMsg.NetStateID, lastSentChatMsgID));
             for (int i = 0; i < chatMsgQueue.Count && i < ChatMessage.MaxMessagesPerPacket; i++)
@@ -1090,10 +1098,10 @@ namespace Barotrauma.Networking
 
         private void OnFileReceived(FileReceiver.FileTransferIn transfer)
         {
-            new GUIMessageBox("Download finished", "File \"" + transfer.FileName + "\" was downloaded succesfully.");
             switch (transfer.FileType)
             {
                 case FileTransferType.Submarine:
+                    new GUIMessageBox("Download finished", "File \"" + transfer.FileName + "\" was downloaded succesfully.");
                     var newSub = new Submarine(transfer.FilePath);
                     Submarine.SavedSubmarines.RemoveAll(s => s.Name == newSub.Name && s.MD5Hash.Hash == newSub.MD5Hash.Hash);
                     Submarine.SavedSubmarines.Add(newSub);

Barotrauma/BarotraumaShared/Source/GameSession/GameModes/MultiplayerCampaign.cs

@@ -356,7 +356,7 @@ namespace Barotrauma
             //server has a newer save file
             if (NetIdUtils.IdMoreRecent(saveID, campaign.PendingSaveID))
             {
-                //stop any active campaign save transfers, they're outdated now
+                /*//stop any active campaign save transfers, they're outdated now
                 List<FileReceiver.FileTransferIn> saveTransfers = 
                     GameMain.Client.FileReceiver.ActiveTransfers.FindAll(t => t.FileType == FileTransferType.CampaignSave);
 
@@ -365,7 +365,7 @@ namespace Barotrauma
                     GameMain.Client.FileReceiver.StopTransfer(transfer);                    
                 }
 
-                GameMain.Client.RequestFile(FileTransferType.CampaignSave, null, null);
+                GameMain.Client.RequestFile(FileTransferType.CampaignSave, null, null);*/
                 campaign.PendingSaveID = saveID;
             }
             //we've got the latest save file

Barotrauma/BarotraumaShared/Source/Networking/Client.cs

@@ -44,6 +44,7 @@ namespace Barotrauma.Networking
         public UInt16 lastRecvEntityEventID = 0;
 
         public UInt16 lastRecvCampaignUpdate = 0;
+        public UInt16 lastRecvCampaignSave = 0;
 
         public List<ChatMessage> chatMsgQueue = new List<ChatMessage>();
         public UInt16 lastChatMsgQueueID;

Barotrauma/BarotraumaShared/Source/Networking/FileTransfer/FileSender.cs

@@ -156,6 +156,7 @@ namespace Barotrauma.Networking
             catch (Exception e)
             {
                 DebugConsole.ThrowError("Failed to initiate file transfer", e);
+                return null;
             }
 
             OnStarted(transfer);

Barotrauma/BarotraumaShared/Source/Networking/GameServer.cs

@@ -601,7 +601,11 @@ namespace Barotrauma.Networking
                         c.lastRecvGeneralUpdate = NetIdUtils.Clamp(inc.ReadUInt16(), c.lastRecvGeneralUpdate, GameMain.NetLobbyScreen.LastUpdateID);
                         c.lastRecvChatMsgID     = NetIdUtils.Clamp(inc.ReadUInt16(), c.lastRecvChatMsgID, c.lastChatMsgQueueID);
 
-                        c.lastRecvCampaignUpdate    = inc.ReadUInt16();
+                        c.lastRecvCampaignSave      = inc.ReadUInt16();
+                        if (c.lastRecvCampaignSave > 0)
+                        {
+                            c.lastRecvCampaignUpdate    = inc.ReadUInt16();
+                        }
                         break;
                     case ClientNetObject.CHAT_MESSAGE:
                         ChatMessage.ServerRead(inc, c);
@@ -816,6 +820,15 @@ namespace Barotrauma.Networking
                 }
 
                 ClientWriteLobby(c);
+
+                MultiplayerCampaign campaign = GameMain.GameSession?.GameMode as MultiplayerCampaign;
+                if (campaign != null && NetIdUtils.IdMoreRecent(campaign.LastSaveID, c.lastRecvCampaignSave))
+                { 
+                    if (!fileSender.ActiveTransfers.Any(t => t.Connection == c.Connection && t.FileType == FileTransferType.CampaignSave))
+                    {
+                        fileSender.StartTransfer(c.Connection, FileTransferType.CampaignSave, GameMain.GameSession.SavePath);
+                    }
+                }
             }
         }
 
@@ -1976,7 +1989,7 @@ namespace Barotrauma.Networking
                 gender = Gender.Male;
                 headSpriteId = 0;
 
-                DebugConsole.Log("Received invalid characterinfo from \"" +sender.name+"\"! { "+e.Message+" }");
+                DebugConsole.Log("Received invalid characterinfo from \"" + sender.name + "\"! { " + e.Message + " }");
             }
 
             List<JobPrefab> jobPreferences = new List<JobPrefab>();