fix: Fixed NetworkVariables being truncated to short.MaxValue when NetworkConfig.EnsureNetworkVariableLengthSafety is enabled. (#1811)

* fix: Fixed NetworkVariables being truncated to short.MaxValue when NetworkConfig.EnsureNetworkVariableLengthSafety is enabled.

In the process it was discovered that FRAGMENTED_MESSAGE_MAX_SIZE was actually larger than BytePacker.WriteValueBitPacked can support, so that was reduced to the actual correct max value.

* changelog

* minor syntax fix

Co-authored-by: Fatih Mar <[email protected]>

Author: ShadauxCat

com.unity.netcode.gameobjects/CHANGELOG.md

@@ -25,6 +25,7 @@ Additional documentation and release notes are available at [Multiplayer Documen
 - Fixed issue where NetworkManager would continue starting even if the NetworkTransport selected failed. (#1780)
 - Fixed issue when spawning new player if an already existing player exists it does not remove IsPlayer from the previous player (#1779)
 - Fixed lack of notification that NetworkManager and NetworkObject cannot be added to the same GameObject with in-editor notifications (#1777)
+- Network variable updates are no longer limited to 32,768 bytes when NetworkConfig.EnsureNetworkVariableLengthSafety is enabled. The limits are now determined by what the transport can send in a message. (#1811)
 
 ## [1.0.0-pre.6] - 2022-03-02
 

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

@@ -57,7 +57,7 @@ public void Serialize(FastBufferWriter writer)
                 {
                     if (!shouldWrite)
                     {
-                        writer.WriteValueSafe((ushort)0);
+                        BytePacker.WriteValueBitPacked(writer, 0);
                     }
                 }
                 else
@@ -69,15 +69,15 @@ public void Serialize(FastBufferWriter writer)
                 {
                     if (NetworkBehaviour.NetworkManager.NetworkConfig.EnsureNetworkVariableLengthSafety)
                     {
-                        var tempWriter = new FastBufferWriter(MessagingSystem.NON_FRAGMENTED_MESSAGE_MAX_SIZE, Allocator.Temp, short.MaxValue);
-                        networkVariable.WriteDelta(tempWriter);
+                        var tempWriter = new FastBufferWriter(MessagingSystem.NON_FRAGMENTED_MESSAGE_MAX_SIZE, Allocator.Temp, MessagingSystem.FRAGMENTED_MESSAGE_MAX_SIZE);
+                        NetworkBehaviour.NetworkVariableFields[i].WriteDelta(tempWriter);
+                        BytePacker.WriteValueBitPacked(writer, tempWriter.Length);
 
-                        if (!writer.TryBeginWrite(FastBufferWriter.GetWriteSize<ushort>() + tempWriter.Length))
+                        if (!writer.TryBeginWrite(tempWriter.Length))
                         {
                             throw new OverflowException($"Not enough space in the buffer to write {nameof(NetworkVariableDeltaMessage)}");
                         }
 
-                        writer.WriteValue((ushort)tempWriter.Length);
                         tempWriter.CopyTo(writer);
                     }
                     else
@@ -135,10 +135,10 @@ public void Handle(ref NetworkContext context)
                 {
                     for (int i = 0; i < networkBehaviour.NetworkVariableFields.Count; i++)
                     {
-                        ushort varSize = 0;
+                        int varSize = 0;
                         if (networkManager.NetworkConfig.EnsureNetworkVariableLengthSafety)
                         {
-                            m_ReceivedNetworkVariableData.ReadValueSafe(out varSize);
+                            ByteUnpacker.ReadValueBitPacked(m_ReceivedNetworkVariableData, out varSize);
 
                             if (varSize == 0)
                             {

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

@@ -67,7 +67,7 @@ internal uint GetMessageType(Type t)
         }
 
         public const int NON_FRAGMENTED_MESSAGE_MAX_SIZE = 1300;
-        public const int FRAGMENTED_MESSAGE_MAX_SIZE = int.MaxValue;
+        public const int FRAGMENTED_MESSAGE_MAX_SIZE = BytePacker.BitPackedIntMax;
 
         internal struct MessageWithHandler
         {

com.unity.netcode.gameobjects/Runtime/Serialization/BytePacker.cs

@@ -10,7 +10,7 @@ namespace Unity.Netcode
     public static class BytePacker
     {
 #if UNITY_NETCODE_DEBUG_NO_PACKING
-        
+
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void WriteValuePacked<T>(FastBufferWriter writer, T value) where T: unmanaged => writer.WriteValueSafe(value);
 #else
@@ -277,10 +277,21 @@ public static void WriteValuePacked(FastBufferWriter writer, string s)
 
 
 #if UNITY_NETCODE_DEBUG_NO_PACKING
-        
+
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void WriteValueBitPacked<T>(FastBufferWriter writer, T value) where T: unmanaged => writer.WriteValueSafe(value);
 #else
+
+        public const ushort BitPackedUshortMax = (1 << 15) - 1;
+        public const short BitPackedShortMax = (1 << 14) - 1;
+        public const short BitPackedShortMin = -(1 << 14);
+        public const uint BitPackedUintMax = (1 << 30) - 1;
+        public const int BitPackedIntMax = (1 << 29) - 1;
+        public const int BitPackedIntMin = -(1 << 29);
+        public const ulong BitPackedULongMax = (1L << 61) - 1;
+        public const long BitPackedLongMax = (1L << 60) - 1;
+        public const long BitPackedLongMin = -(1L << 60);
+
         /// <summary>
         /// Writes a 14-bit signed short to the buffer in a bit-encoded packed format.
         /// The first bit indicates whether the value is 1 byte or 2.
@@ -307,7 +318,7 @@ public static void WriteValuePacked(FastBufferWriter writer, string s)
         public static void WriteValueBitPacked(FastBufferWriter writer, ushort value)
         {
 #if DEVELOPMENT_BUILD || UNITY_EDITOR
-            if (value >= 0b1000_0000_0000_0000)
+            if (value >= BitPackedUshortMax)
             {
                 throw new ArgumentException("BitPacked ushorts must be <= 15 bits");
             }
@@ -356,7 +367,7 @@ public static void WriteValueBitPacked(FastBufferWriter writer, ushort value)
         public static void WriteValueBitPacked(FastBufferWriter writer, uint value)
         {
 #if DEVELOPMENT_BUILD || UNITY_EDITOR
-            if (value >= 0b0100_0000_0000_0000_0000_0000_0000_0000)
+            if (value > BitPackedUintMax)
             {
                 throw new ArgumentException("BitPacked uints must be <= 30 bits");
             }
@@ -396,7 +407,7 @@ public static void WriteValueBitPacked(FastBufferWriter writer, uint value)
         public static void WriteValueBitPacked(FastBufferWriter writer, ulong value)
         {
 #if DEVELOPMENT_BUILD || UNITY_EDITOR
-            if (value >= 0b0010_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000)
+            if (value > BitPackedULongMax)
             {
                 throw new ArgumentException("BitPacked ulongs must be <= 61 bits");
             }