feat: Allow reliable sends to go over maximum payload size (#2081)

* feat: Allow reliable sends to go over maximum payload size

Author: simon-lemay-unity

com.unity.netcode.gameobjects/CHANGELOG.md

@@ -9,6 +9,8 @@ Additional documentation and release notes are available at [Multiplayer Documen
 
 ### Changed
 
+- When using `UnityTransport`, _reliable_ payloads are now allowed to exceed the configured 'Max Payload Size'. Unreliable payloads remain bounded by this setting. (#2081)
+
 ### Fixed
 
 - Fixed issue where NetworkAnimator was not removing its subscription from OnClientConnectedCallback when despawned during the shutdown sequence. (#2074)

com.unity.netcode.gameobjects/Runtime/Transports/UTP/UnityTransport.cs

@@ -158,11 +158,11 @@ public int MaxPacketQueueSize
             set => m_MaxPacketQueueSize = value;
         }
 
-        [Tooltip("The maximum size of a payload that can be handled by the transport.")]
+        [Tooltip("The maximum size of an unreliable payload that can be handled by the transport.")]
         [SerializeField]
         private int m_MaxPayloadSize = InitialMaxPayloadSize;
 
-        /// <summary>The maximum size of a payload that can be handled by the transport.</summary>
+        /// <summary>The maximum size of an unreliable payload that can be handled by the transport.</summary>
         public int MaxPayloadSize
         {
             get => m_MaxPayloadSize;
@@ -1148,14 +1148,14 @@ public override NetcodeNetworkEvent PollEvent(out ulong clientId, out ArraySegme
         /// <param name="networkDelivery">The delivery type (QoS) to send data with</param>
         public override void Send(ulong clientId, ArraySegment<byte> payload, NetworkDelivery networkDelivery)
         {
-            if (payload.Count > m_MaxPayloadSize)
+            var pipeline = SelectSendPipeline(networkDelivery);
+
+            if (pipeline != m_ReliableSequencedPipeline && payload.Count > m_MaxPayloadSize)
             {
-                Debug.LogError($"Payload of size {payload.Count} larger than configured 'Max Payload Size' ({m_MaxPayloadSize}).");
+                Debug.LogError($"Unreliable payload of size {payload.Count} larger than configured 'Max Payload Size' ({m_MaxPayloadSize}).");
                 return;
             }
 
-            var pipeline = SelectSendPipeline(networkDelivery);
-
             var sendTarget = new SendTarget(clientId, pipeline);
             if (!m_SendQueue.TryGetValue(sendTarget, out var queue))
             {

com.unity.netcode.gameobjects/Tests/Runtime/Transports/UnityTransportTests.cs

@@ -457,5 +457,26 @@ public IEnumerator SendQueuesFlushedOnRemoteClientDisconnect([ValueSource("k_Del
 
             yield return null;
         }
+
+        [UnityTest]
+        public IEnumerator ReliablePayloadsCanBeLargerThanMaximum()
+        {
+            InitializeTransport(out m_Server, out m_ServerEvents);
+            InitializeTransport(out m_Client1, out m_Client1Events);
+
+            m_Server.StartServer();
+            m_Client1.StartClient();
+
+            yield return WaitForNetworkEvent(NetworkEvent.Connect, m_Client1Events);
+
+            var payloadSize = UnityTransport.InitialMaxPayloadSize + 1;
+            var data = new ArraySegment<byte>(new byte[payloadSize]);
+
+            m_Server.Send(m_Client1.ServerClientId, data, NetworkDelivery.Reliable);
+
+            yield return WaitForNetworkEvent(NetworkEvent.Data, m_Client1Events);
+
+            yield return null;
+        }
     }
 }