refactor(SocketLayer)!: moving MaxPacketSize to SocketFactory

Allows max packet size to be set by sockets rather than the general peer config.

BREAKING CHANGE: socket factories now have to override MaxPacketSize property

Assets/Mirage/Runtime/NetworkClient.cs

@@ -116,15 +116,16 @@ public void Connect(string address = null, ushort? port = null)
             if (logger.LogEnabled()) logger.Log($"Client connecting to endpoint: {endPoint}");
 
             ISocket socket = SocketFactory.CreateClientSocket();
+            int maxPacketSize = SocketFactory.MaxPacketSize;
             MessageHandler = new MessageHandler(World, DisconnectOnException);
             var dataHandler = new DataHandler(MessageHandler);
             Metrics = EnablePeerMetrics ? new Metrics(MetricsSize) : null;
 
             Config config = PeerConfig ?? new Config();
 
-            NetworkWriterPool.Configure(config.MaxPacketSize);
+            NetworkWriterPool.Configure(maxPacketSize);
 
-            peer = new Peer(socket, dataHandler, config, LogFactory.GetLogger<Peer>(), Metrics);
+            peer = new Peer(socket, maxPacketSize, dataHandler, config, LogFactory.GetLogger<Peer>(), Metrics);
             peer.OnConnected += Peer_OnConnected;
             peer.OnConnectionFailed += Peer_OnConnectionFailed;
             peer.OnDisconnected += Peer_OnDisconnected;

Assets/Mirage/Runtime/NetworkServer.cs

@@ -211,7 +211,8 @@ public void StartServer(NetworkClient localClient = null)
                 };
             }
 
-            NetworkWriterPool.Configure(config.MaxPacketSize);
+            int maxPacketSize = SocketFactory.MaxPacketSize;
+            NetworkWriterPool.Configure(maxPacketSize);
 
             // Are we listening for incoming connections?
             // If yes, set up a socket for incoming connections (we're a multiplayer game).
@@ -222,7 +223,7 @@ public void StartServer(NetworkClient localClient = null)
                 ISocket socket = SocketFactory.CreateServerSocket();
 
                 // Tell the peer to use that newly created socket.
-                peer = new Peer(socket, dataHandler, config, LogFactory.GetLogger<Peer>(), Metrics);
+                peer = new Peer(socket, maxPacketSize, dataHandler, config, LogFactory.GetLogger<Peer>(), Metrics);
                 peer.OnConnected += Peer_OnConnected;
                 peer.OnDisconnected += Peer_OnDisconnected;
                 // Bind it to the endpoint.

Assets/Mirage/Runtime/Serialization/NetworkWriterPool.cs

@@ -18,8 +18,8 @@ public static class NetworkWriterPool
         static NetworkWriterPool()
         {
             // auto configure so that pool can be used without having to manually call it
-            var config = new Config();
-            Configure(config.MaxPacketSize);
+            // 1300 is greater than udp's MTU value
+            Configure(1300);
         }
 
         /// <summary>

Assets/Mirage/Runtime/SocketLayer/AckSystem.cs

@@ -77,7 +77,7 @@ internal class AckSystem
         /// <param name="connection"></param>
         /// <param name="ackTimeout">how long after last send before sending empty ack</param>
         /// <param name="time"></param>
-        public AckSystem(IRawConnection connection, Config config, ITime time, Pool<ByteBuffer> bufferPool, Metrics metrics = null)
+        public AckSystem(IRawConnection connection, Config config, int maxPacketSize, ITime time, Pool<ByteBuffer> bufferPool, Metrics metrics = null)
         {
             if (config == null) throw new ArgumentNullException(nameof(config));
 
@@ -90,7 +90,7 @@ public AckSystem(IRawConnection connection, Config config, ITime time, Pool<Byte
             ackTimeout = config.TimeBeforeEmptyAck;
             emptyAckLimit = config.EmptyAckLimit;
             receivesBeforeEmpty = config.ReceivesBeforeEmptyAck;
-            maxPacketSize = config.MaxPacketSize;
+            this.maxPacketSize = maxPacketSize;
             maxPacketsInSendBufferPerConnection = config.MaxReliablePacketsInSendBufferPerConnection;
 
             maxFragments = config.MaxReliableFragments;

Assets/Mirage/Runtime/SocketLayer/Config.cs

@@ -48,24 +48,6 @@ public class Config
         /// </summary>
         public float DisconnectDuration = 1;
 
-        /// <summary>
-        /// IPv6 + UDP Header
-        /// </summary>
-        const int HEADER_SIZE = 40 + 8;
-
-        /// <summary>
-        /// MTU is expected to be atleast this number
-        /// </summary>
-        const int MIN_MTU = 1280;
-
-        /// <summary>
-        /// Max size of array that will be sent to or can be received from <see cref="ISocket"/>
-        /// <para>This will also be the size of all buffers used by <see cref="Peer"/></para>
-        /// <para>This is not max message size because this size includes packets header added by <see cref="Peer"/></para>
-        /// </summary>
-        // todo move these settings to socket
-        public int MaxPacketSize = MIN_MTU - HEADER_SIZE;
-
         /// <summary>
         /// How many buffers to create at start
         /// </summary>
@@ -111,7 +93,7 @@ public class Config
 
         /// <summary>
         /// How many fragments large reliable message can be split into
-        /// <para>if set to 0 then messages over <see cref="MaxPacketSize"/> will not be allowed to be sent</para>
+        /// <para>if set to 0 then messages over <see cref="SocketFactory.MaxPacketSize"/> will not be allowed to be sent</para>
         /// <para>max value is 255</para>
         /// </summary>
         public int MaxReliableFragments = 5;

Assets/Mirage/Runtime/SocketLayer/Connection.cs

@@ -109,7 +109,7 @@ public ConnectionState State
 
         IEndPoint IConnection.EndPoint => EndPoint;
 
-        internal Connection(Peer peer, IEndPoint endPoint, IDataHandler dataHandler, Config config, Time time, Pool<ByteBuffer> bufferPool, ILogger logger, Metrics metrics)
+        internal Connection(Peer peer, IEndPoint endPoint, IDataHandler dataHandler, Config config, int maxPacketSize, Time time, Pool<ByteBuffer> bufferPool, ILogger logger, Metrics metrics)
         {
             this.peer = peer;
             this.logger = logger;
@@ -124,7 +124,7 @@ internal Connection(Peer peer, IEndPoint endPoint, IDataHandler dataHandler, Con
             disconnectedTracker = new DisconnectedTracker(config, time);
 
             this.metrics = metrics;
-            ackSystem = new AckSystem(this, config, time, bufferPool, metrics);
+            ackSystem = new AckSystem(this, config, maxPacketSize, time, bufferPool, metrics);
         }
 
         public override string ToString()

Assets/Mirage/Runtime/SocketLayer/Peer.cs

@@ -42,6 +42,7 @@ public sealed class Peer : IPeer
         readonly ISocket socket;
         readonly IDataHandler dataHandler;
         readonly Config config;
+        readonly int maxPacketSize;
         readonly Time time;
 
         readonly ConnectKeyValidator connectKeyValidator;
@@ -59,19 +60,22 @@ public sealed class Peer : IPeer
         /// </summary>
         bool active;
 
-        public Peer(ISocket socket, IDataHandler dataHandler, Config config = null, ILogger logger = null, Metrics metrics = null)
+        public Peer(ISocket socket, int maxPacketSize, IDataHandler dataHandler, Config config = null, ILogger logger = null, Metrics metrics = null)
         {
             this.logger = logger;
             this.metrics = metrics;
             this.config = config ?? new Config();
+            this.maxPacketSize = maxPacketSize;
+            if (maxPacketSize < AckSystem.MIN_RELIABLE_HEADER_SIZE + 1)
+                throw new ArgumentException($"Max packet size too small for AckSystem header", nameof(maxPacketSize));
 
             this.socket = socket ?? throw new ArgumentNullException(nameof(socket));
             this.dataHandler = dataHandler ?? throw new ArgumentNullException(nameof(dataHandler));
             time = new Time();
 
             connectKeyValidator = new ConnectKeyValidator(this.config.key);
 
-            bufferPool = new Pool<ByteBuffer>(ByteBuffer.CreateNew, this.config.MaxPacketSize, this.config.BufferPoolStartSize, this.config.BufferPoolMaxSize, this.logger);
+            bufferPool = new Pool<ByteBuffer>(ByteBuffer.CreateNew, maxPacketSize, this.config.BufferPoolStartSize, this.config.BufferPoolMaxSize, this.logger);
             Application.quitting += Application_quitting;
         }
 
@@ -253,8 +257,8 @@ private void ReceiveLoop()
                     int length = socket.Receive(buffer.array, out IEndPoint receiveEndPoint);
 
                     // this should never happen. buffer size is only MTU, if socket returns higher length then it has a bug.
-                    if (length > config.MaxPacketSize)
-                        throw new IndexOutOfRangeException($"Socket returned length above MTU. MaxPacketSize:{config.MaxPacketSize} length:{length}");
+                    if (length > maxPacketSize)
+                        throw new IndexOutOfRangeException($"Socket returned length above MTU. MaxPacketSize:{maxPacketSize} length:{length}");
 
                     var packet = new Packet(buffer, length);
 
@@ -432,7 +436,7 @@ private Connection CreateNewConnection(IEndPoint _newEndPoint)
             // this is so that we can re-use the endpoint (reduces alloc) for receive and not worry about changing internal data needed for each connection
             IEndPoint endPoint = _newEndPoint?.CreateCopy();
 
-            var connection = new Connection(this, endPoint, dataHandler, config, time, bufferPool, logger, metrics);
+            var connection = new Connection(this, endPoint, dataHandler, config, maxPacketSize, time, bufferPool, logger, metrics);
             connection.SetReceiveTime();
             connections.Add(endPoint, connection);
             return connection;

Assets/Mirage/Runtime/SocketLayer/SocketFactory.cs

@@ -31,6 +31,10 @@ public interface IHasPort
     /// </remarks>
     public abstract class SocketFactory : MonoBehaviour
     {
+        /// <summary>Max size for packets sent to or received from Socket
+        /// <para>Called once when Sockets are created</para></summary>
+        public abstract int MaxPacketSize { get; }
+
         /// <summary>Creates a <see cref="ISocket"/> to be used by <see cref="Peer"/> on the server</summary>
         /// <exception cref="NotSupportedException">Throw when Server is not supported on current platform</exception>
         public abstract ISocket CreateServerSocket();

Assets/Mirage/Runtime/Sockets/Udp/UdpSocketFactory.cs

@@ -20,6 +20,8 @@ public sealed class UdpSocketFactory : SocketFactory, IHasAddress, IHasPort
         [Header("NanoSocket options")]
         public int BufferSize = 256 * 1024;
 
+        public override int MaxPacketSize => UdpMTU.MaxPacketSize;
+
         bool useNanoSocket => SocketLib == SocketLib.Native || (SocketLib == SocketLib.Automatic && IsDesktop);
 
         string IHasAddress.Address
@@ -178,4 +180,25 @@ IEndPoint IEndPoint.CreateCopy()
             return new EndPointWrapper(copy);
         }
     }
+
+    public class UdpMTU
+    {
+        /// <summary>
+        /// IPv6 + UDP Header
+        /// </summary>
+        const int HEADER_SIZE = 40 + 8;
+
+        /// <summary>
+        /// MTU is expected to be atleast this number
+        /// </summary>
+        const int MIN_MTU = 1280;
+
+        /// <summary>
+        /// Max size of array that will be sent to or can be received from <see cref="ISocket"/>
+        /// <para>This will also be the size of all buffers used by <see cref="Peer"/></para>
+        /// <para>This is not max message size because this size includes packets header added by <see cref="Peer"/></para>
+        /// </summary>
+        // todo move these settings to socket
+        public static int MaxPacketSize => MIN_MTU - HEADER_SIZE;
+    }
 }

Assets/Tests/Common/TestSocketFactory.cs

@@ -141,6 +141,7 @@ public class TestSocketFactory : SocketFactory
 
         int clientNameIndex;
         int serverNameIndex;
+        public override int MaxPacketSize => 1300;
         public override ISocket CreateClientSocket()
         {
             return new TestSocket($"Client {clientNameIndex++}");

Assets/Tests/SocketLayer/AckSystem/AckSystemTest.cs

@@ -20,8 +20,9 @@ public static void SendReliable(this AckSystem ackSystem, byte[] array)
     /// </summary>
     public class AckSystemTestBase
     {
+        public const int MAX_PACKET_SIZE = 1300;
         protected readonly Random rand = new Random();
-        protected Pool<ByteBuffer> bufferPool = new Pool<ByteBuffer>(ByteBuffer.CreateNew, 1300, 100, 1000);
+        protected Pool<ByteBuffer> bufferPool = new Pool<ByteBuffer>(ByteBuffer.CreateNew, MAX_PACKET_SIZE, 100, 1000);
 
         protected byte[] createRandomData(int id)
         {

Assets/Tests/SocketLayer/AckSystem/AckSystemTest_BufferSize.cs

@@ -19,7 +19,7 @@ public void ThrowsIfTooManyMessageAreSent()
             {
                 connection = new SubIRawConnection()
             };
-            instance.ackSystem = new AckSystem(instance.connection, config, time, bufferPool);
+            instance.ackSystem = new AckSystem(instance.connection, config, MAX_PACKET_SIZE, time, bufferPool);
 
             for (int i = 0; i < 50; i++)
             {
@@ -50,7 +50,7 @@ public void ThrowIfRingBufferIsfull()
             {
                 connection = new SubIRawConnection()
             };
-            instance.ackSystem = new AckSystem(instance.connection, config, time, bufferPool);
+            instance.ackSystem = new AckSystem(instance.connection, config, MAX_PACKET_SIZE, time, bufferPool);
 
             for (int i = 0; i < 255; i++)
             {

Assets/Tests/SocketLayer/AckSystem/AckSystemTest_Fragmentation_Receive.cs

@@ -18,21 +18,21 @@ public class AckSystemTest_Fragmentation_Receive : AckSystemTestBase
         public void SetUp()
         {
             config = new Config();
-            int mtu = config.MaxPacketSize;
+            int mtu = MAX_PACKET_SIZE;
             int bigSize = (int)(mtu * 1.5f);
 
             message = CreateBigData(1, bigSize);
 
             var sender = new AckTestInstance();
             sender.connection = new SubIRawConnection();
-            sender.ackSystem = new AckSystem(sender.connection, config, new Time(), bufferPool);
+            sender.ackSystem = new AckSystem(sender.connection, config, MAX_PACKET_SIZE, new Time(), bufferPool);
             sender.ackSystem.SendReliable(message);
             packet1 = sender.packet(0);
             packet2 = sender.packet(1);
 
 
             var connection = new SubIRawConnection();
-            ackSystem = new AckSystem(connection, config, new Time(), bufferPool);
+            ackSystem = new AckSystem(connection, config, MAX_PACKET_SIZE, new Time(), bufferPool);
         }
 
         byte[] CreateBigData(int id, int size)
@@ -80,7 +80,7 @@ public void MessageShouldBeInQueueAfterReceive()
 
             ackSystem.ReceiveReliable(packet2, packet2.Length, true);
 
-            int bytesIn1 = config.MaxPacketSize - AckSystem.MIN_RELIABLE_FRAGMENT_HEADER_SIZE;
+            int bytesIn1 = MAX_PACKET_SIZE - AckSystem.MIN_RELIABLE_FRAGMENT_HEADER_SIZE;
             int bytesIn2 = message.Length - bytesIn1;
 
             Assert.IsTrue(ackSystem.NextReliablePacket(out AckSystem.ReliableReceived first));

Assets/Tests/SocketLayer/AckSystem/AckSystemTest_Fragmentation_Send.cs

@@ -15,14 +15,14 @@ public class AckSystemTest_Fragmentation_Send : AckSystemTestBase
         public void SetUp()
         {
             var config = new Config();
-            int mtu = config.MaxPacketSize;
+            int mtu = MAX_PACKET_SIZE;
             int bigSize = (int)(mtu * 1.5f);
 
             byte[] message = CreateBigData(1, bigSize);
 
             instance = new AckTestInstance();
             instance.connection = new SubIRawConnection();
-            instance.ackSystem = new AckSystem(instance.connection, config, new Time(), bufferPool);
+            instance.ackSystem = new AckSystem(instance.connection, config, MAX_PACKET_SIZE, new Time(), bufferPool);
 
             // create and send n messages
             instance.messages = new List<byte[]>();

Assets/Tests/SocketLayer/AckSystem/AckSystemTest_Notify_1stSend.cs

@@ -29,7 +29,7 @@ public void SetUp()
             maxSequence = (ushort)((1 << config.SequenceSize) - 1);
 
             connection = new SubIRawConnection();
-            ackSystem = new AckSystem(connection, config, new Time(), bufferPool);
+            ackSystem = new AckSystem(connection, config, MAX_PACKET_SIZE, new Time(), bufferPool);
 
             message = createRandomData(1);
             ackSystem.SendNotify(message);

Assets/Tests/SocketLayer/AckSystem/AckSystemTest_Notify_DroppedSends.cs

@@ -39,12 +39,12 @@ public void SetUp()
 
             instance1 = new AckTestInstance();
             instance1.connection = new SubIRawConnection();
-            instance1.ackSystem = new AckSystem(instance1.connection, config, new Time(), bufferPool);
+            instance1.ackSystem = new AckSystem(instance1.connection, config, MAX_PACKET_SIZE, new Time(), bufferPool);
 
 
             instance2 = new AckTestInstance();
             instance2.connection = new SubIRawConnection();
-            instance2.ackSystem = new AckSystem(instance2.connection, config, new Time(), bufferPool);
+            instance2.ackSystem = new AckSystem(instance2.connection, config, MAX_PACKET_SIZE, new Time(), bufferPool);
 
             // create and send n messages
             instance1.messages = new List<byte[]>();

Assets/Tests/SocketLayer/AckSystem/AckSystemTest_Notify_ManySends.cs

@@ -22,7 +22,7 @@ public void SetUp()
 
             instance = new AckTestInstance();
             instance.connection = new SubIRawConnection();
-            instance.ackSystem = new AckSystem(instance.connection, new Config(), new Time(), bufferPool);
+            instance.ackSystem = new AckSystem(instance.connection, new Config(), MAX_PACKET_SIZE, new Time(), bufferPool);
 
             // create and send n messages
             instance.messages = new List<byte[]>();

Assets/Tests/SocketLayer/AckSystem/AckSystemTest_Notify_NoDroppedSends.cs

@@ -28,13 +28,13 @@ public void SetUp()
 
             instance1 = new AckTestInstance();
             instance1.connection = new SubIRawConnection();
-            instance1.ackSystem = new AckSystem(instance1.connection, config, new Time(), bufferPool);
+            instance1.ackSystem = new AckSystem(instance1.connection, config, MAX_PACKET_SIZE, new Time(), bufferPool);
             received1 = new List<ArraySegment<byte>>();
 
 
             instance2 = new AckTestInstance();
             instance2.connection = new SubIRawConnection();
-            instance2.ackSystem = new AckSystem(instance2.connection, config, new Time(), bufferPool);
+            instance2.ackSystem = new AckSystem(instance2.connection, config, MAX_PACKET_SIZE, new Time(), bufferPool);
             received2 = new List<ArraySegment<byte>>();
 
             // create and send n messages

Assets/Tests/SocketLayer/AckSystem/AckSystemTest_Reliable.cs

@@ -138,12 +138,12 @@ public void SetUp()
 
             instance1 = new AckTestInstance();
             instance1.connection = new SubIRawConnection();
-            instance1.ackSystem = new AckSystem(instance1.connection, config, time, bufferPool);
+            instance1.ackSystem = new AckSystem(instance1.connection, config, MAX_PACKET_SIZE, time, bufferPool);
 
 
             instance2 = new AckTestInstance();
             instance2.connection = new SubIRawConnection();
-            instance2.ackSystem = new AckSystem(instance2.connection, config, time, bufferPool);
+            instance2.ackSystem = new AckSystem(instance2.connection, config, MAX_PACKET_SIZE, time, bufferPool);
 
             badSocket = new BadSocket(instance1, instance2);
 

Assets/Tests/SocketLayer/ByteUtilsTest.cs

@@ -88,7 +88,7 @@ public void WriteReadULongTest()
         }
 
         [Test]
-        [Explicit("c# only lets you bit shift by max of 63, It only takes first 6 bits, so will drop any extra bits and try to shift anyway")]
+        [Ignore("c# only lets you bit shift by max of 63, It only takes first 6 bits, so will drop any extra bits and try to shift anyway")]
         public void UlongShift()
         {
             ulong value = 0xfUL;
@@ -100,7 +100,7 @@ public void UlongShift()
 
         [Test]
         [Description("this test should fail")]
-        [Explicit("c# only lets you bit shift by max of 63. It only takes first 6 bits, so will drop any extra bits and try to shift anyway")]
+        [Ignore("c# only lets you bit shift by max of 63. It only takes first 6 bits, so will drop any extra bits and try to shift anyway")]
         public void UlongShift_ShouldFail()
         {
             ulong value = 0xfUL;