fix: increases maximum message size to int.MaxValue (#1384)

com.unity.netcode.gameobjects/Runtime/Configuration/NetworkConstants.cs

@@ -5,6 +5,6 @@ namespace Unity.Netcode
     /// </summary>
     internal static class NetworkConstants
     {
-        internal const string PROTOCOL_VERSION = "14.0.0";
+        internal const string PROTOCOL_VERSION = "15.0.0";
     }
 }

com.unity.netcode.gameobjects/Runtime/Core/NetworkBehaviour.cs

@@ -82,7 +82,8 @@ internal void __sendServerRpc(FastBufferWriter writer, uint rpcMethodId, ServerR
                     SystemOwner = NetworkManager,
                     // header information isn't valid since it's not a real message.
                     // Passing false to canDefer prevents it being accessed.
-                    Header = new MessageHeader()
+                    Header = new MessageHeader(),
+                    SerializedHeaderSize = 0,
                 };
                 message.Handle(tempBuffer, context, NetworkManager, NetworkManager.ServerClientId, false);
                 rpcMessageSize = tempBuffer.Length;
@@ -188,7 +189,8 @@ internal unsafe void __sendClientRpc(FastBufferWriter writer, uint rpcMethodId,
                     SystemOwner = NetworkManager,
                     // header information isn't valid since it's not a real message.
                     // Passing false to canDefer prevents it being accessed.
-                    Header = new MessageHeader()
+                    Header = new MessageHeader(),
+                    SerializedHeaderSize = 0,
                 };
                 message.Handle(tempBuffer, context, NetworkManager, NetworkManager.ServerClientId, false);
                 messageSize = tempBuffer.Length;

com.unity.netcode.gameobjects/Runtime/Messaging/CustomMessageManager.cs

@@ -28,7 +28,7 @@ internal CustomMessagingManager(NetworkManager networkManager)
         /// </summary>
         public event UnnamedMessageDelegate OnUnnamedMessage;
 
-        internal void InvokeUnnamedMessage(ulong clientId, FastBufferReader reader)
+        internal void InvokeUnnamedMessage(ulong clientId, FastBufferReader reader, int serializedHeaderSize)
         {
             if (OnUnnamedMessage != null)
             {
@@ -40,7 +40,7 @@ internal void InvokeUnnamedMessage(ulong clientId, FastBufferReader reader)
                     ((UnnamedMessageDelegate)handler).Invoke(clientId, reader);
                 }
             }
-            m_NetworkManager.NetworkMetrics.TrackUnnamedMessageReceived(clientId, reader.Length + FastBufferWriter.GetWriteSize<MessageHeader>());
+            m_NetworkManager.NetworkMetrics.TrackUnnamedMessageReceived(clientId, reader.Length + serializedHeaderSize);
         }
 
         /// <summary>
@@ -115,9 +115,9 @@ public void SendUnnamedMessage(ulong clientId, FastBufferWriter messageBuffer, N
         private Dictionary<ulong, string> m_MessageHandlerNameLookup32 = new Dictionary<ulong, string>();
         private Dictionary<ulong, string> m_MessageHandlerNameLookup64 = new Dictionary<ulong, string>();
 
-        internal void InvokeNamedMessage(ulong hash, ulong sender, FastBufferReader reader)
+        internal void InvokeNamedMessage(ulong hash, ulong sender, FastBufferReader reader, int serializedHeaderSize)
         {
-            var bytesCount = reader.Length + FastBufferWriter.GetWriteSize<MessageHeader>();
+            var bytesCount = reader.Length + serializedHeaderSize;
 
             if (m_NetworkManager == null)
             {

com.unity.netcode.gameobjects/Runtime/Messaging/MessageHeader.cs

@@ -11,11 +11,12 @@ internal struct MessageHeader
         /// unchanged - if new messages are added or messages are removed, MessageType assignments may be
         /// calculated differently.
         /// </summary>
-        public byte MessageType;
+        public uint MessageType;
 
         /// <summary>
         /// The total size of the message, NOT including the header.
+        /// Stored as a uint to avoid zig-zag encoding, but capped at int.MaxValue.
         /// </summary>
-        public ushort MessageSize;
+        public uint MessageSize;
     }
 }

com.unity.netcode.gameobjects/Runtime/Messaging/Messages/NamedMessage.cs

@@ -16,7 +16,7 @@ public static void Receive(FastBufferReader reader, in NetworkContext context)
             var message = new NamedMessage();
             reader.ReadValueSafe(out message.Hash);
 
-            ((NetworkManager)context.SystemOwner).CustomMessagingManager.InvokeNamedMessage(message.Hash, context.SenderId, reader);
+            ((NetworkManager)context.SystemOwner).CustomMessagingManager.InvokeNamedMessage(message.Hash, context.SenderId, reader, context.SerializedHeaderSize);
         }
     }
 }

com.unity.netcode.gameobjects/Runtime/Messaging/Messages/UnnamedMessage.cs

@@ -11,7 +11,7 @@ public unsafe void Serialize(FastBufferWriter writer)
 
         public static void Receive(FastBufferReader reader, in NetworkContext context)
         {
-            ((NetworkManager)context.SystemOwner).CustomMessagingManager.InvokeUnnamedMessage(context.SenderId, reader);
+            ((NetworkManager)context.SystemOwner).CustomMessagingManager.InvokeUnnamedMessage(context.SenderId, reader, context.SerializedHeaderSize);
         }
     }
 }

com.unity.netcode.gameobjects/Runtime/Messaging/MessagingSystem.cs

@@ -23,6 +23,7 @@ private struct ReceiveQueueItem
             public MessageHeader Header;
             public ulong SenderId;
             public float Timestamp;
+            public int MessageHeaderSerializedSize;
         }
 
         private struct SendQueueItem
@@ -46,27 +47,27 @@ public SendQueueItem(NetworkDelivery delivery, int writerSize, Allocator writerA
         private MessageHandler[] m_MessageHandlers = new MessageHandler[255];
         private Type[] m_ReverseTypeMap = new Type[255];
 
-        private Dictionary<Type, byte> m_MessageTypes = new Dictionary<Type, byte>();
+        private Dictionary<Type, uint> m_MessageTypes = new Dictionary<Type, uint>();
         private Dictionary<ulong, NativeList<SendQueueItem>> m_SendQueues = new Dictionary<ulong, NativeList<SendQueueItem>>();
 
         private List<INetworkHooks> m_Hooks = new List<INetworkHooks>();
 
-        private byte m_HighMessageType;
+        private uint m_HighMessageType;
         private object m_Owner;
         private IMessageSender m_MessageSender;
         private bool m_Disposed;
 
         internal Type[] MessageTypes => m_ReverseTypeMap;
         internal MessageHandler[] MessageHandlers => m_MessageHandlers;
-        internal int MessageHandlerCount => m_HighMessageType;
+        internal uint MessageHandlerCount => m_HighMessageType;
 
-        internal byte GetMessageType(Type t)
+        internal uint GetMessageType(Type t)
         {
             return m_MessageTypes[t];
         }
 
         public const int NON_FRAGMENTED_MESSAGE_MAX_SIZE = 1300;
-        public const int FRAGMENTED_MESSAGE_MAX_SIZE = 64000;
+        public const int FRAGMENTED_MESSAGE_MAX_SIZE = int.MaxValue;
 
         internal struct MessageWithHandler
         {
@@ -165,14 +166,23 @@ internal void HandleIncomingData(ulong clientId, ArraySegment<byte> data, float
 
                     for (var messageIdx = 0; messageIdx < batchHeader.BatchSize; ++messageIdx)
                     {
-                        if (!batchReader.TryBeginRead(sizeof(MessageHeader)))
+
+                        var messageHeader = new MessageHeader();
+                        var position = batchReader.Position;
+                        try
+                        {
+                            ByteUnpacker.ReadValueBitPacked(batchReader, out messageHeader.MessageType);
+                            ByteUnpacker.ReadValueBitPacked(batchReader, out messageHeader.MessageSize);
+                        }
+                        catch (OverflowException)
                         {
                             NetworkLog.LogWarning("Received a batch that didn't have enough data for all of its batches, ending early!");
-                            return;
+                            throw;
                         }
-                        batchReader.ReadValue(out MessageHeader messageHeader);
 
-                        if (!batchReader.TryBeginRead(messageHeader.MessageSize))
+                        var receivedHeaderSize = batchReader.Position - position;
+
+                        if (!batchReader.TryBeginRead((int)messageHeader.MessageSize))
                         {
                             NetworkLog.LogWarning("Received a message that claimed a size larger than the packet, ending early!");
                             return;
@@ -185,9 +195,10 @@ internal void HandleIncomingData(ulong clientId, ArraySegment<byte> data, float
                             // Copy the data for this message into a new FastBufferReader that owns that memory.
                             // We can't guarantee the memory in the ArraySegment stays valid because we don't own it,
                             // so we must move it to memory we do own.
-                            Reader = new FastBufferReader(batchReader.GetUnsafePtrAtCurrentPosition(), Allocator.TempJob, messageHeader.MessageSize)
+                            Reader = new FastBufferReader(batchReader.GetUnsafePtrAtCurrentPosition(), Allocator.TempJob, (int)messageHeader.MessageSize),
+                            MessageHeaderSerializedSize = receivedHeaderSize,
                         });
-                        batchReader.Seek(batchReader.Position + messageHeader.MessageSize);
+                        batchReader.Seek(batchReader.Position + (int)messageHeader.MessageSize);
                     }
                     for (var hookIdx = 0; hookIdx < m_Hooks.Count; ++hookIdx)
                     {
@@ -210,7 +221,7 @@ private bool CanReceive(ulong clientId, Type messageType)
             return true;
         }
 
-        public void HandleMessage(in MessageHeader header, FastBufferReader reader, ulong senderId, float timestamp)
+        public void HandleMessage(in MessageHeader header, FastBufferReader reader, ulong senderId, float timestamp, int serializedHeaderSize)
         {
             if (header.MessageType >= m_HighMessageType)
             {
@@ -223,8 +234,10 @@ public void HandleMessage(in MessageHeader header, FastBufferReader reader, ulon
                 SystemOwner = m_Owner,
                 SenderId = senderId,
                 Timestamp = timestamp,
-                Header = header
+                Header = header,
+                SerializedHeaderSize = serializedHeaderSize,
             };
+
             var type = m_ReverseTypeMap[header.MessageType];
             if (!CanReceive(senderId, type))
             {
@@ -236,6 +249,7 @@ public void HandleMessage(in MessageHeader header, FastBufferReader reader, ulon
             {
                 m_Hooks[hookIdx].OnBeforeReceiveMessage(senderId, type, reader.Length + FastBufferWriter.GetWriteSize<MessageHeader>());
             }
+
             var handler = m_MessageHandlers[header.MessageType];
             using (reader)
             {
@@ -265,7 +279,7 @@ internal unsafe void ProcessIncomingMessageQueue()
             {
                 // Avoid copies...
                 ref var item = ref m_IncomingMessageQueue.GetUnsafeList()->ElementAt(index);
-                HandleMessage(item.Header, item.Reader, item.SenderId, item.Timestamp);
+                HandleMessage(item.Header, item.Reader, item.SenderId, item.Timestamp, item.MessageHeaderSerializedSize);
                 if (m_Disposed)
                 {
                     return;
@@ -328,64 +342,68 @@ internal unsafe int SendMessage<TMessageType, TClientIdListType>(in TMessageType
             }
 
             var maxSize = delivery == NetworkDelivery.ReliableFragmentedSequenced ? FRAGMENTED_MESSAGE_MAX_SIZE : NON_FRAGMENTED_MESSAGE_MAX_SIZE;
-            var tmpSerializer = new FastBufferWriter(NON_FRAGMENTED_MESSAGE_MAX_SIZE - FastBufferWriter.GetWriteSize<MessageHeader>(), Allocator.Temp, maxSize - FastBufferWriter.GetWriteSize<MessageHeader>());
-            using (tmpSerializer)
+
+            using var tmpSerializer = new FastBufferWriter(NON_FRAGMENTED_MESSAGE_MAX_SIZE - FastBufferWriter.GetWriteSize<MessageHeader>(), Allocator.Temp, maxSize - FastBufferWriter.GetWriteSize<MessageHeader>());
+
+            message.Serialize(tmpSerializer);
+
+            using var headerSerializer = new FastBufferWriter(FastBufferWriter.GetWriteSize<MessageHeader>(), Allocator.Temp);
+
+            var header = new MessageHeader
             {
-                message.Serialize(tmpSerializer);
+                MessageSize = (ushort)tmpSerializer.Length,
+                MessageType = m_MessageTypes[typeof(TMessageType)],
+            };
+            BytePacker.WriteValueBitPacked(headerSerializer, header.MessageType);
+            BytePacker.WriteValueBitPacked(headerSerializer, header.MessageSize);
 
-                for (var i = 0; i < clientIds.Count; ++i)
-                {
-                    var clientId = clientIds[i];
+            for (var i = 0; i < clientIds.Count; ++i)
+            {
+                var clientId = clientIds[i];
 
-                    if (!CanSend(clientId, typeof(TMessageType), delivery))
-                    {
-                        continue;
-                    }
+                if (!CanSend(clientId, typeof(TMessageType), delivery))
+                {
+                    continue;
+                }
 
-                    for (var hookIdx = 0; hookIdx < m_Hooks.Count; ++hookIdx)
-                    {
-                        m_Hooks[hookIdx].OnBeforeSendMessage(clientId, typeof(TMessageType), delivery);
-                    }
+                for (var hookIdx = 0; hookIdx < m_Hooks.Count; ++hookIdx)
+                {
+                    m_Hooks[hookIdx].OnBeforeSendMessage(clientId, typeof(TMessageType), delivery);
+                }
 
-                    var sendQueueItem = m_SendQueues[clientId];
-                    if (sendQueueItem.Length == 0)
+                var sendQueueItem = m_SendQueues[clientId];
+                if (sendQueueItem.Length == 0)
+                {
+                    sendQueueItem.Add(new SendQueueItem(delivery, NON_FRAGMENTED_MESSAGE_MAX_SIZE, Allocator.TempJob,
+                        maxSize));
+                    sendQueueItem.GetUnsafeList()->ElementAt(0).Writer.Seek(sizeof(BatchHeader));
+                }
+                else
+                {
+                    ref var lastQueueItem = ref sendQueueItem.GetUnsafeList()->ElementAt(sendQueueItem.Length - 1);
+                    if (lastQueueItem.NetworkDelivery != delivery ||
+                        lastQueueItem.Writer.MaxCapacity - lastQueueItem.Writer.Position
+                        < tmpSerializer.Length + headerSerializer.Length)
                     {
                         sendQueueItem.Add(new SendQueueItem(delivery, NON_FRAGMENTED_MESSAGE_MAX_SIZE, Allocator.TempJob,
                             maxSize));
-                        sendQueueItem.GetUnsafeList()->ElementAt(0).Writer.Seek(sizeof(BatchHeader));
-                    }
-                    else
-                    {
-                        ref var lastQueueItem = ref sendQueueItem.GetUnsafeList()->ElementAt(sendQueueItem.Length - 1);
-                        if (lastQueueItem.NetworkDelivery != delivery ||
-                            lastQueueItem.Writer.MaxCapacity - lastQueueItem.Writer.Position
-                            < tmpSerializer.Length + FastBufferWriter.GetWriteSize<MessageHeader>())
-                        {
-                            sendQueueItem.Add(new SendQueueItem(delivery, NON_FRAGMENTED_MESSAGE_MAX_SIZE, Allocator.TempJob,
-                                maxSize));
-                            sendQueueItem.GetUnsafeList()->ElementAt(sendQueueItem.Length - 1).Writer.Seek(sizeof(BatchHeader));
-                        }
+                        sendQueueItem.GetUnsafeList()->ElementAt(sendQueueItem.Length - 1).Writer.Seek(sizeof(BatchHeader));
                     }
+                }
 
-                    ref var writeQueueItem = ref sendQueueItem.GetUnsafeList()->ElementAt(sendQueueItem.Length - 1);
-                    writeQueueItem.Writer.TryBeginWrite(tmpSerializer.Length + FastBufferWriter.GetWriteSize<MessageHeader>());
-                    var header = new MessageHeader
-                    {
-                        MessageSize = (ushort)tmpSerializer.Length,
-                        MessageType = m_MessageTypes[typeof(TMessageType)],
-                    };
+                ref var writeQueueItem = ref sendQueueItem.GetUnsafeList()->ElementAt(sendQueueItem.Length - 1);
+                writeQueueItem.Writer.TryBeginWrite(tmpSerializer.Length + headerSerializer.Length);
 
-                    writeQueueItem.Writer.WriteValue(header);
-                    writeQueueItem.Writer.WriteBytes(tmpSerializer.GetUnsafePtr(), tmpSerializer.Length);
-                    writeQueueItem.BatchHeader.BatchSize++;
-                    for (var hookIdx = 0; hookIdx < m_Hooks.Count; ++hookIdx)
-                    {
-                        m_Hooks[hookIdx].OnAfterSendMessage(clientId, typeof(TMessageType), delivery, tmpSerializer.Length + FastBufferWriter.GetWriteSize<MessageHeader>());
-                    }
+                writeQueueItem.Writer.WriteBytes(headerSerializer.GetUnsafePtr(), headerSerializer.Length);
+                writeQueueItem.Writer.WriteBytes(tmpSerializer.GetUnsafePtr(), tmpSerializer.Length);
+                writeQueueItem.BatchHeader.BatchSize++;
+                for (var hookIdx = 0; hookIdx < m_Hooks.Count; ++hookIdx)
+                {
+                    m_Hooks[hookIdx].OnAfterSendMessage(clientId, typeof(TMessageType), delivery, tmpSerializer.Length + headerSerializer.Length);
                 }
-
-                return tmpSerializer.Length + FastBufferWriter.GetWriteSize<MessageHeader>();
             }
+
+            return tmpSerializer.Length + headerSerializer.Length;
         }
 
         private struct PointerListWrapper<T> : IReadOnlyList<T>

com.unity.netcode.gameobjects/Runtime/Messaging/NetworkContext.cs

@@ -25,5 +25,10 @@ internal ref struct NetworkContext
         /// The header data that was sent with the message
         /// </summary>
         public MessageHeader Header;
+
+        /// <summary>
+        /// The actual serialized size of the header when packed into the buffer
+        /// </summary>
+        public int SerializedHeaderSize;
     }
 }

com.unity.netcode.gameobjects/Runtime/Spawning/NetworkSpawnManager.cs

@@ -27,6 +27,7 @@ private struct TriggerData
             public MessageHeader Header;
             public ulong SenderId;
             public float Timestamp;
+            public int SerializedHeaderSize;
         }
         private struct TriggerInfo
         {
@@ -117,7 +118,8 @@ internal unsafe void TriggerOnSpawn(ulong networkObjectId, FastBufferReader read
                 Reader = new FastBufferReader(reader.GetUnsafePtr(), Allocator.Persistent, reader.Length),
                 Header = context.Header,
                 Timestamp = context.Timestamp,
-                SenderId = context.SenderId
+                SenderId = context.SenderId,
+                SerializedHeaderSize = context.SerializedHeaderSize
             });
         }
 
@@ -501,7 +503,7 @@ private void SpawnNetworkObjectLocallyCommon(NetworkObject networkObject, ulong
                 foreach (var trigger in triggerInfo.TriggerData)
                 {
                     // Reader will be disposed within HandleMessage
-                    NetworkManager.MessagingSystem.HandleMessage(trigger.Header, trigger.Reader, trigger.SenderId, trigger.Timestamp);
+                    NetworkManager.MessagingSystem.HandleMessage(trigger.Header, trigger.Reader, trigger.SenderId, trigger.Timestamp, trigger.SerializedHeaderSize);
                 }
 
                 triggerInfo.TriggerData.Dispose();