feat: Upgrades networking to use io_uring. (#2315)

> [!IMPORTANT]
> **Breaking Changes**
> - DecodePacket and EncodePacket delegates replaced with IClientEncryption interface
> - NetState.Connection (Socket) replaced with internal RingSocket management
> - NetState.RecvPipe and NetState.SendPipe removed (buffers managed internally)

## Summary

Upgrades the networking stack from PollGroup-based I/O to io_uring, significantly improving I/O performance on Linux.
This also adds native client encryption support for encrypted UO clients.

## Major Changes

io_uring Networking Architecture
- Replaced PollGroup with IORingGroup for async socket I/O operations
- Removed Pipe.cs (mirrored ring buffer) and TcpServer.cs in favor of RingSocketManager
- Added NetState.Network.cs - centralized network infrastructure handling accept, recv, send, and disconnect
completions
- Added SocketHelper.cs - platform-specific socket utilities for raw socket handle operations (getpeername,
getsockname)
- Buffer management now handled by RingSocketManager with configurable slab allocation

### Client Encryption Support
- Added full encryption stack in Network/Encryption/:
  - EncryptionConfig.cs - configurable encryption modes (None, Unencrypted, Encrypted, Both)
  - EncryptionManager.cs - encryption detection and initialization for login/game packets
  - LoginEncryption.cs - handles login packet encryption with version-derived keys
  - GameEncryption.cs - handles game server encryption using Twofish
  - TwofishEngine.cs - optimized Twofish block cipher implementation
  - LoginKeys.cs - encryption key table for client versions
  - IClientEncryption.cs - interface for client encryption implementations

### NetState Improvements
- Replaced Socket Connection with RingSocket _socket for managed socket lifecycle
- Changed from GCHandle polling to event-based completion processing
- Disconnect handling now properly waits for pending sends to flush
- Simplified connecting socket management using lazy queue removal

### Configuration
- New settings: network.encryptionMode and network.encryptionDebug
- Encryption mode flags: Unencrypted, Encrypted, or Both

### Dependencies
- Replaced PollGroup NuGet package with IORingGroup
- Linux requires liburing-dev / liburing-devel package

### Test plan

- Verify server starts and accepts connections on Linux with io_uring
- Verify server starts and accepts connections on Windows (fallback to IOCP)
- Test unencrypted client connections (ClassicUO with encryption disabled)
- Test encrypted client connections if available
- Verify graceful disconnect flushes pending data
- Confirm CI builds pass on all target platforms

.github/workflows/build-test.yml

@@ -42,7 +42,9 @@ jobs:
 
   build-linux:
     runs-on: ubuntu-latest
-    container: ${{ matrix.container }}
+    container:
+      image: ${{ matrix.container }}
+      options: --security-opt seccomp=unconfined
     name: Build (${{ matrix.name }})
     strategy:
       fail-fast: false
@@ -68,14 +70,17 @@ jobs:
             packageManager: dnf
 
     steps:
-      - name: Enable EPEL
-        run: dnf upgrade --refresh -y && dnf install -y epel-release epel-next-release
-        if: ${{ startsWith(matrix.name, 'CentOS')  }}
+      - name: Enable EPEL and CRB for CentOS
+        run: |
+          dnf upgrade --refresh -y
+          dnf install -y epel-release epel-next-release
+          dnf config-manager --set-enabled crb
+        if: ${{ startsWith(matrix.name, 'CentOS') }}
       - name: Install Prerequisites using dnf
-        run: dnf makecache --refresh && dnf install -y findutils libicu libdeflate-devel zstd libargon2-devel
+        run: dnf makecache --refresh && dnf install -y findutils libicu libdeflate-devel zstd libargon2-devel liburing-devel
         if: ${{ matrix.packageManager == 'dnf' }}
       - name: Install Prerequisites using apt
-        run: apt-get update -y && apt-get install -y curl libicu-dev libdeflate-dev zstd libargon2-dev tzdata
+        run: apt-get update -y && apt-get install -y curl libicu-dev libdeflate-dev zstd libargon2-dev tzdata liburing-dev
         if: ${{ matrix.packageManager == 'apt' }}
       - uses: actions/checkout@v4
         with:

Projects/Server.Tests/Fixtures/TestServerInitializer.cs

@@ -78,6 +78,9 @@ public static class TestServerInitializer
             Core.LoopContext = new EventLoopContext();
             Core.Expansion = Expansion.EJ;
 
+            // Configure networking (initializes RingSocketManager for tests)
+            Server.Network.NetState.Configure();
+
             // Configure / Initialize
             TestMapDefinitions.ConfigureTestMapDefinitions();
 

Projects/Server.Tests/Helpers/PacketTestUtilities.cs

@@ -1,16 +1,94 @@
 using System;
+using System.Collections.Generic;
+using System.Net;
 using System.Net.Sockets;
+using System.Network;
 using Server.Network;
 
-namespace Server.Tests.Network
-{
-    public static class PacketTestUtilities
-    {
-        public static Span<byte> Compile(this Packet p) =>
-            p.Compile(false, out var length).AsSpan(0, length);
+namespace Server.Tests.Network;
 
-        public static NetState CreateTestNetState() => new(
-            new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
-        );
+public static class PacketTestUtilities
+{
+    private static nint _testListener;
+    private static int _testPort;
+    private static readonly List<Socket> _testSocketClients = [];
+
+    public static Span<byte> Compile(this Packet p) => p.Compile(false, out var length).AsSpan(0, length);
+
+    /// <summary>
+    /// Creates a NetState for unit testing.
+    /// Uses a real Socket and RingSocket with actual buffers.
+    /// Must be disposed after use (use 'using' statement).
+    /// </summary>
+    public static NetState CreateTestNetState()
+    {
+        NetState.Slice(); // Process disconnects/disposes
+
+        for (var i = _testSocketClients.Count - 1; i >= 0; i--)
+        {
+            var sock = _testSocketClients[i];
+            if (!sock.Connected)
+            {
+                sock.Dispose();
+                _testSocketClients.RemoveAt(i);
+            }
+        }
+
+        var ring = NetState.Ring;
+
+        // Create a test listener if we don't have one (using the ring for RIO-compatible sockets)
+        if (_testListener == 0)
+        {
+            // Disable rate limiter for tests - we don't want connection attempts to be throttled
+            // NetState.DisableRateLimiter();
+
+            _testListener = ring.CreateListener("127.0.0.1", 0, 128);
+            if (_testListener == -1)
+            {
+                throw new InvalidOperationException("Failed to create test listener");
+            }
+
+            _testPort = SocketHelper.GetLocalEndPoint(_testListener)?.Port ?? 0;
+            if (_testPort == 0)
+            {
+                throw new InvalidOperationException("Failed to get test listener port");
+            }
+        }
+
+        // Queue an accept operation
+        ring.PrepareAccept(_testListener, 0, 0, IORingUserData.EncodeAccept());
+        ring.Submit();
+
+        Core._now = DateTime.UtcNow;
+
+        // Create a client socket and connect to trigger the accept
+        var testSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
+        testSocket.Connect(IPAddress.Loopback, _testPort);
+        _testSocketClients.Add(testSocket);
+
+        // Slice until we have a new NetState instance added
+        // AcceptEx is asynchronous, so we may need to wait/retry
+        const int maxRetries = 100;
+        for (var i = 0; i < maxRetries; i++)
+        {
+            NetState.Slice();
+
+            // Get the latest instance connected.
+            foreach (var ns in NetState.Instances)
+            {
+                if (ns.ConnectedOn == Core._now)
+                {
+                    return ns;
+                }
+            }
+
+            // Wait a bit for AcceptEx to complete
+            if (i < maxRetries - 1)
+            {
+                System.Threading.Thread.Sleep(1);
+            }
+        }
+
+        throw new Exception("Failed to slice for test NetState instance after retries");
     }
 }

Projects/Server.Tests/Server.Tests.csproj

@@ -16,6 +16,13 @@
         <DataFiles Include="$(SolutionDir)\Distribution\Data\**" />
         <ProjectReference Include="..\UOContent\UOContent.csproj" />
     </ItemGroup>
+    <!-- Copy native ioring.dll for tests -->
+    <ItemGroup>
+        <Content Include="C:\Repositories\IORingGroup\IORingGroup\runtimes\win-x64\native\ioring.dll" Condition="Exists('C:\Repositories\IORingGroup\IORingGroup\runtimes\win-x64\native\ioring.dll')">
+            <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+            <Link>ioring.dll</Link>
+        </Content>
+    </ItemGroup>
     <Target Name="CopyData" AfterTargets="AfterBuild">
         <Copy SourceFiles="@(DataFiles)" DestinationFolder="$(OutDir)\Data\%(RecursiveDir)" />
     </Target>

Projects/Server.Tests/Tests/Maps/ClientEnumeratorTests.cs

@@ -1,8 +1,8 @@
 using System;
 using System.Collections.Generic;
-using System.Net.Sockets;
 using Server.Accounting;
 using Server.Network;
+using Server.Tests.Network;
 using Xunit;
 
 namespace Server.Tests.Maps;
@@ -356,7 +356,7 @@ public class ClientEnumeratorTests
     {
         var map = Map.Felucca;
         var center = new Point3D(900, 900, 0);
-        var range = 5;
+        const int range = 5;
 
         var clients = new (NetState, Mobile)[3];
         try
@@ -456,8 +456,8 @@ public class ClientEnumeratorTests
 
     private static (NetState, Mobile) CreateClientWithMobile(Map map, Point3D location)
     {
-        var socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
-        var ns = new NetState(socket);
+        // Create test NetState with real socket and buffers
+        var ns = PacketTestUtilities.CreateTestNetState();
 
         // Assign a mock account to avoid null reference issues
         ns.Account = new MockAccount();
@@ -533,16 +533,16 @@ public class ClientEnumeratorTests
         }
     }
 
-    private static void DeleteAll((NetState, Mobile)[] clients)
+    private static void DeleteAll((NetState state, Mobile m)[] clients)
     {
         for (var i = 0; i < clients.Length; i++)
         {
-            if (clients[i].Item1 != null)
+            if (clients[i].state != null)
             {
-                clients[i].Item1.Mobile = null;
-                clients[i].Item1.Disconnect("Test cleanup");
+                clients[i].state.Mobile = null;
+                clients[i].state.Dispose();
             }
-            clients[i].Item2?.Delete();
+            clients[i].m?.Delete();
         }
     }
 }

Projects/Server.Tests/Tests/Maps/MapSelectionTests.cs

@@ -4,7 +4,7 @@ using Server.Json;
 using System.Text.Json.Serialization;
 using System.Text.Json;
 
-namespace Server.Tests.Tests.Maps
+namespace Server.Tests.Maps
 {
     public class MapSelectionTests
     {

Projects/Server.Tests/Tests/Network/Packets/Outgoing/AccountPacketTests.cs

@@ -92,7 +92,7 @@ public class AccountPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendChangeCharacter(account);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -105,7 +105,7 @@ public class AccountPacketTests
 
         ns.SendClientVersionRequest();
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -117,7 +117,7 @@ public class AccountPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendCharacterDeleteResult(DeleteResultType.BadRequest);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -129,7 +129,7 @@ public class AccountPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendPopupMessage(PMMessage.LoginSyncError);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -156,7 +156,7 @@ public class AccountPacketTests
         var expected = new SupportedFeatures(ns).Compile();
         ns.SendSupportedFeature();
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -177,7 +177,7 @@ public class AccountPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendLoginConfirmation(m);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -189,7 +189,7 @@ public class AccountPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendLoginComplete();
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -214,7 +214,7 @@ public class AccountPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendCharacterListUpdate(account);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -248,7 +248,7 @@ public class AccountPacketTests
 
         ns.SendCharacterList();
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -281,7 +281,7 @@ public class AccountPacketTests
 
         ns.SendCharacterList();
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -294,7 +294,7 @@ public class AccountPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendAccountLoginRejected(reason);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -313,7 +313,7 @@ public class AccountPacketTests
 
         ns.SendAccountLoginAck();
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -321,7 +321,7 @@ public class AccountPacketTests
     public void TestPlayServerAck()
     {
         var si = new ServerInfo("Test Server", 0, TimeZoneInfo.Local, IPEndPoint.Parse("127.0.0.1"));
-        var authId = 0x123456;
+        const int authId = 0x123456;
 
         var expected = new PlayServerAck(si, authId).Compile();
 
@@ -329,7 +329,7 @@ public class AccountPacketTests
 
         ns.SendPlayServerAck(si, authId);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/Server.Tests/Tests/Network/Packets/Outgoing/CombatPacketTests.cs

@@ -17,7 +17,7 @@ public class CombatPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendSwing(attacker, defender);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -29,7 +29,7 @@ public class CombatPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendSetWarMode(warmode);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -43,7 +43,7 @@ public class CombatPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendChangeCombatant(serial);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/Server.Tests/Tests/Network/Packets/Outgoing/ContainerPacketTests.cs

@@ -7,7 +7,6 @@ namespace Server.Tests.Network;
 [Collection("Sequential Server Tests")]
 public class ContainerPacketTests
 {
-
     [Fact]
     public void TestContainerDisplay()
     {
@@ -19,7 +18,7 @@ public class ContainerPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendDisplayContainer(serial, gumpId);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -35,7 +34,7 @@ public class ContainerPacketTests
         ns.ProtocolChanges = ns.ProtocolChanges | ProtocolChanges.ContainerGridLines | ProtocolChanges.HighSeas;
         ns.SendDisplayContainer(serial, gumpId);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -49,7 +48,7 @@ public class ContainerPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendDisplaySpellbook(serial);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -64,7 +63,7 @@ public class ContainerPacketTests
         ns.ProtocolChanges = ns.ProtocolChanges | ProtocolChanges.ContainerGridLines | ProtocolChanges.HighSeas;
         ns.SendDisplaySpellbook(serial);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -85,7 +84,7 @@ public class ContainerPacketTests
         ns.SendSpellbookContent(serial, graphic, offset, content);
         ObjectPropertyList.Enabled = opl;
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -102,7 +101,7 @@ public class ContainerPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendSpellbookContent(serial, graphic, offset, content);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -120,7 +119,7 @@ public class ContainerPacketTests
         ns.ProtocolChanges |= ProtocolChanges.ContainerGridLines;
         ns.SendSpellbookContent(serial, graphic, offset, content);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -135,7 +134,7 @@ public class ContainerPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendContainerContentUpdate(item);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -151,7 +150,7 @@ public class ContainerPacketTests
         ns.ProtocolChanges |= ProtocolChanges.ContainerGridLines;
         ns.SendContainerContentUpdate(item);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -172,7 +171,7 @@ public class ContainerPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendContainerContent(m, cont);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -194,7 +193,7 @@ public class ContainerPacketTests
         ns.ProtocolChanges |= ProtocolChanges.ContainerGridLines;
         ns.SendContainerContent(m, cont);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/Server.Tests/Tests/Network/Packets/Outgoing/DamagePacketTests.cs

@@ -16,7 +16,7 @@ public class DamagePacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendDamage(serial, inputAmount);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -32,7 +32,7 @@ public class DamagePacketTests
 
         ns.SendDamage(serial, inputAmount);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/Server.Tests/Tests/Network/Packets/Outgoing/EffectPacketTests.cs

@@ -17,7 +17,7 @@ public class EffectPackets
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendSoundEffect(soundID, p);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -99,7 +99,7 @@ public class EffectPackets
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendScreenEffect(screenType);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 

Projects/Server.Tests/Tests/Network/Packets/Outgoing/EquipmentPacketTests.cs

@@ -42,7 +42,7 @@ public class EquipmentPacketTests
             new List<EquipInfoAttribute>(info.Attributes)
         );
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -59,7 +59,7 @@ public class EquipmentPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendEquipUpdate(item);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/Server.Tests/Tests/Network/Packets/Outgoing/GumpPacketTests.cs

@@ -15,7 +15,7 @@ public class GumpPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendCloseGump(typeId, buttonId);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -32,7 +32,7 @@ public class GumpPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendDisplaySignGump(gumpSerial, gumpId, unknownString, caption);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -46,7 +46,7 @@ public class GumpPacketTests
         var expected = gump.Compile(ns).Compile();
         ns.SendGump(gump);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -65,7 +65,7 @@ public class GumpPacketTests
         var expected = gump.Compile(ns).Compile();
         ns.SendGump(gump);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/Server.Tests/Tests/Network/Packets/Outgoing/ItemPacketTests.cs

@@ -38,7 +38,7 @@ public class ItemPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendWorldItem(item);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -74,7 +74,7 @@ public class ItemPacketTests
         ns.ProtocolChanges = ProtocolChanges.StygianAbyss;
         ns.SendWorldItem(item);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -110,7 +110,7 @@ public class ItemPacketTests
         ns.ProtocolChanges = ProtocolChanges.StygianAbyss | ProtocolChanges.HighSeas;
         ns.SendWorldItem(item);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/Server.Tests/Tests/Network/Packets/Outgoing/LightPacketTests.cs

@@ -15,7 +15,7 @@ public class LightPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendGlobalLightLevel(lightLevel);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -29,7 +29,7 @@ public class LightPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendPersonalLightLevel(serial, lightLevel);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/Server.Tests/Tests/Network/Packets/Outgoing/MapPacketTests.cs

@@ -15,7 +15,7 @@ public class MapPatchesTests
 
         ns.SendMapPatches();
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -27,7 +27,7 @@ public class MapPatchesTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendInvalidMap();
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -42,7 +42,7 @@ public class MapPatchesTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendMapChange(map);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/Server.Tests/Tests/Network/Packets/Outgoing/MenuPacketTests.cs

@@ -47,7 +47,7 @@ public class MenuPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendDisplayItemListMenu(menu);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -67,7 +67,7 @@ public class MenuPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendDisplayQuestionMenu(menu);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -95,7 +95,7 @@ public class MenuPacketTests
 
         ns.SendDisplayContextMenu(menu);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/Server.Tests/Tests/Network/Packets/Outgoing/MessagePacketTests.cs

@@ -42,7 +42,7 @@ public class MessageTests
             args
         );
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -87,7 +87,7 @@ public class MessageTests
             args
         );
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -125,7 +125,7 @@ public class MessageTests
             text
         );
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -165,7 +165,7 @@ public class MessageTests
             text
         );
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -180,7 +180,7 @@ public class MessageTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendFollowMessage(serial, serial2);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -195,7 +195,7 @@ public class MessageTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendHelpResponse(s, text);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -215,9 +215,8 @@ public class MessageTests
             using var ns = PacketTestUtilities.CreateTestNetState();
             ns.SendPrompt(prompt);
 
-            var result = ns.SendPipe.Reader.AvailableToRead();
+            var result = ns.SendBuffer.GetReadSpan();
             AssertThat.Equal(result, expected);
-
         }
     }
 }

Projects/Server.Tests/Tests/Network/Packets/Outgoing/MobilePacketTests.cs

@@ -17,7 +17,7 @@ public class MobilePacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendDeathAnimation(killed, corpse);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -32,7 +32,7 @@ public class MobilePacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendBondedStatus(petSerial, bonded);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -52,7 +52,7 @@ public class MobilePacketTests
 
         ns.SendMobileMoving(m, noto);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -70,7 +70,7 @@ public class MobilePacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendMobileName(m);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -102,7 +102,7 @@ public class MobilePacketTests
             delay
         );
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -128,7 +128,7 @@ public class MobilePacketTests
             delay
         );
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -148,7 +148,7 @@ public class MobilePacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendMobileHealthbar(m, Healthbar.Poison);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -169,7 +169,7 @@ public class MobilePacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendMobileHealthbar(m, Healthbar.Yellow);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -192,7 +192,7 @@ public class MobilePacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendMobileStatusCompact(m, canBeRenamed);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -225,7 +225,7 @@ public class MobilePacketTests
         var expected = new MobileStatus(beholder, beheld, ns).Compile();
         ns.SendMobileStatus(beholder, beheld);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -263,7 +263,7 @@ public class MobilePacketTests
         var expected = new MobileStatusExtended(m, ns).Compile();
         ns.SendMobileStatus(m, m);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
         Core.Expansion = oldExpansion;
         expansionInfo.MobileStatusVersion = oldVersion;
@@ -284,7 +284,7 @@ public class MobilePacketTests
         var expected = new MobileUpdate(m, ns.StygianAbyss).Compile();
         ns.SendMobileUpdate(m);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -339,7 +339,7 @@ public class MobilePacketTests
         var expected = new MobileIncoming(ns, beholder, beheld).Compile();
         ns.SendMobileIncoming(beholder, beheld);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -356,7 +356,7 @@ public class MobilePacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendMobileHits(m);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -373,7 +373,7 @@ public class MobilePacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendMobileHits(m, true);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -390,7 +390,7 @@ public class MobilePacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendMobileMana(m);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -407,7 +407,7 @@ public class MobilePacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendMobileMana(m, true);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -424,7 +424,7 @@ public class MobilePacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendMobileStam(m);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -441,7 +441,7 @@ public class MobilePacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendMobileStam(m, true);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -462,7 +462,7 @@ public class MobilePacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendMobileAttributes(m);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -483,7 +483,7 @@ public class MobilePacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendMobileAttributes(m, true);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -496,7 +496,7 @@ public class MobilePacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendRemoveEntity(e);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/Server.Tests/Tests/Network/Packets/Outgoing/MovementPacketTests.cs

@@ -17,7 +17,7 @@ public class MovementPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendSpeedControl((SpeedControlSetting)speedControl);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -30,7 +30,7 @@ public class MovementPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendMovePlayer(d);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -47,7 +47,7 @@ public class MovementPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendMovementRej(seq, m);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -64,7 +64,7 @@ public class MovementPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendMovementAck(seq, m);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/Server.Tests/Tests/Network/Packets/Outgoing/PlayerPacketTests.cs

@@ -23,7 +23,7 @@ public class PlayerPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendStatLockInfo(m);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -38,7 +38,7 @@ public class PlayerPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendChangeUpdateRange((byte)range);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -50,7 +50,7 @@ public class PlayerPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendDeathStatus();
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -64,7 +64,7 @@ public class PlayerPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendDisplayProfile((Serial)serial, header, body, footer);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -78,7 +78,7 @@ public class PlayerPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendLiftReject(reason);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -90,7 +90,7 @@ public class PlayerPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendLogoutAck();
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -105,7 +105,7 @@ public class PlayerPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendWeather((byte)type, (byte)density, (byte)temp);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -120,7 +120,7 @@ public class PlayerPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendServerChange(p, map);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -135,7 +135,7 @@ public class PlayerPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendSequence(num);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -151,7 +151,7 @@ public class PlayerPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendLaunchBrowser(uri);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -175,7 +175,7 @@ public class PlayerPacketTests
             itemId, hue, amount
         );
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -189,7 +189,7 @@ public class PlayerPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendSeasonChange((byte)season, playSound);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -204,7 +204,7 @@ public class PlayerPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendDisplayPaperdoll((Serial)m, title, warmode, canLift);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -219,7 +219,7 @@ public class PlayerPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendPlayMusic(music);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -233,7 +233,7 @@ public class PlayerPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendScrollMessage(type, tip ,text);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -247,7 +247,7 @@ public class PlayerPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendCurrentTime(date);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -261,7 +261,7 @@ public class PlayerPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendPathfindMessage(p);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -276,7 +276,7 @@ public class PlayerPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendPingAck(ping);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -291,7 +291,7 @@ public class PlayerPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendDisplayHuePicker(huePicker.Serial, huePicker.ItemID);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/Server.Tests/Tests/Network/Packets/Outgoing/SecureTradePacketTests.cs

@@ -23,7 +23,7 @@ public class SecureTradePacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendDisplaySecureTrade(m, firstCont, secondCont, name);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -37,7 +37,7 @@ public class SecureTradePacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendCloseSecureTrade(cont);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -55,7 +55,7 @@ public class SecureTradePacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendUpdateSecureTrade(cont, first, second);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -70,7 +70,7 @@ public class SecureTradePacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendUpdateSecureTrade(cont, flag, gold, plat);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -88,7 +88,7 @@ public class SecureTradePacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendSecureTradeEquip(itemInCont, m);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -108,7 +108,7 @@ public class SecureTradePacketTests
 
         ns.SendSecureTradeEquip(itemInCont, m);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/Server.Tests/Tests/Network/Packets/Outgoing/TargetPacketsTests.cs

@@ -44,7 +44,7 @@ public class TargetPacketsTests
         ns.ProtocolChanges |= ProtocolChanges.HighSeas;
         ns.SendMultiTargetReq(t);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -60,7 +60,7 @@ public class TargetPacketsTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendMultiTargetReq(t);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -71,7 +71,7 @@ public class TargetPacketsTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendCancelTarget();
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -84,7 +84,7 @@ public class TargetPacketsTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendTargetReq(t);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/Server.Tests/Tests/Network/Packets/Outgoing/VendorBuyPacketTests.cs

@@ -29,7 +29,7 @@ public class VendorBuyPacketTests
 
         ns.SendVendorBuyContent(buyStates);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -48,7 +48,7 @@ public class VendorBuyPacketTests
 
         ns.SendDisplayBuyList(vendor.Serial);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -72,7 +72,7 @@ public class VendorBuyPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendVendorBuyList(vendor, buyStates);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -87,7 +87,7 @@ public class VendorBuyPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendEndVendorBuy(vendor.Serial);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/Server.Tests/Tests/Network/Packets/Outgoing/VendorSellPacketTests.cs

@@ -30,7 +30,7 @@ public class VendorSellPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendVendorSellList(vendor.Serial, sellStates);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -45,7 +45,7 @@ public class VendorSellPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendEndVendorSell(vendor.Serial);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/Server.Tests/Tests/Network/Packets/Outgoing/VirtualHairPacketTests.cs

@@ -20,7 +20,7 @@ public class VirtualHairPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendHairEquipUpdatePacket(m, (uint)m.Hair.VirtualSerial, m.Hair.ItemId, m.Hair.Hue, Layer.Hair);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -35,7 +35,7 @@ public class VirtualHairPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendRemoveHairPacket((uint) m.Hair.VirtualSerial);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/Server.Tests/Tests/Network/PipeTests.cs

@@ -1,89 +0,0 @@
-using System;
-using Server.Network;
-using Xunit;
-
-namespace Server.Tests.Network;
-
-public class PipeTests
-{
-    [Fact]
-    public void TestSizeMatchesPageSize()
-    {
-        var pageSize = (uint)Environment.SystemPageSize;
-        using var pipe = new Pipe(128);
-
-        // Available memory should be in increments of system page size minus one.
-        Assert.Equal(pageSize, pipe.Size);
-        Assert.Equal(pageSize - 1, (uint)pipe.Writer.AvailableToWrite().Length);
-    }
-
-    [Fact]
-    public void TestWriteReadsWrap()
-    {
-        var pageSize = (uint)Environment.SystemPageSize;
-        using var pipe = new Pipe(pageSize);
-
-        var span = pipe.Writer.AvailableToWrite();
-
-        for (var i = 0; i < span.Length; i++)
-        {
-            span[i] = (byte)(i % 256);
-        }
-
-        pipe.Writer.Advance((uint)(span.Length - 10));
-
-        var readBytes = pipe.Reader.AvailableToRead();
-
-        // Make a sequence from what we expect.
-        Span<byte> seq = new byte[readBytes.Length];
-        for (var i = 0; i < readBytes.Length; i++)
-        {
-            seq[i] = (byte)(i % 256);
-        }
-
-        AssertThat.Equal(readBytes, seq);
-
-        // Advance by half. Expected writer length should be half + 10
-        pipe.Reader.Advance(pageSize / 2);
-
-        span = pipe.Writer.AvailableToWrite();
-
-        var halfStart = pageSize / 2 + 10;
-
-        Assert.Equal(halfStart, (uint)span.Length);
-
-        seq = new byte[20];
-
-        for (var i = 0; i < 10; i++)
-        {
-            seq[i] = (byte)(0xF5 + i);
-        }
-
-        // The last element, the sentinel, is excluded.
-        // The wrap around values start at 11
-        for (var i = 11; i < 20; i++)
-        {
-            seq[i] = (byte)(i - 11);
-        }
-
-        // Test the uncommitted overwritten memory and shifted offset to make sure the ring is working
-        AssertThat.Equal(span[..20], seq[..20]);
-    }
-
-    [Fact]
-    public void TestWriteReadMatches()
-    {
-        var pipe = new Pipe(16);
-
-        var reader = pipe.Reader;
-        var writer = pipe.Writer;
-
-        for (uint i = 0; i < 16; i++)
-        {
-            writer.Advance(i);
-
-            Assert.Equal((int)i, reader.AvailableToRead().Length);
-            reader.Advance(i);
-        }
-    }
-}

Projects/Server.Tests/Tests/Network/PollGroupTests.cs

@@ -1,37 +0,0 @@
-using System;
-using System.Runtime.InteropServices;
-using System.Threading;
-using Server.Network;
-using Xunit;
-
-namespace Server.Tests.Network;
-
-public class PollGroupTests
-{
-    [Fact]
-    public void TestPollGroup()
-    {
-        // var group = new KQueuePollGroup();
-        var nss = new NetState[2048];
-        var handles = new IntPtr[2048];
-        for (var i = 0; i < nss.Length; i++)
-        {
-            nss[i] = PacketTestUtilities.CreateTestNetState();
-            handles[i] = (IntPtr)nss[i].Handle;
-        }
-
-        GC.AddMemoryPressure(10000000000);
-        GC.Collect();
-        GC.RemoveMemoryPressure(10000000000);
-        GC.Collect();
-
-        Thread.Sleep(1000);
-
-        for (var i = 0; i < nss.Length; i++)
-        {
-            Assert.Equal(nss[i].Handle, (GCHandle)handles[i]);
-        }
-
-        // group.Dispose();
-    }
-}

Projects/Server/Events/SocketConnectionEvent.cs

@@ -1,6 +1,6 @@
 /*************************************************************************
  * ModernUO                                                              *
- * Copyright 2019-2023 - ModernUO Development Team                       *
+ * Copyright 2019-2026 - ModernUO Development Team                       *
  * Email: hi@modernuo.com                                                *
  * File: SocketConnectionEvent.cs                                        *
  *                                                                       *
@@ -14,20 +14,20 @@
  *************************************************************************/
 
 using System;
-using System.Net.Sockets;
+using System.Net;
 using System.Runtime.CompilerServices;
 
 namespace Server;
 
 public class SocketConnectEventArgs
 {
-    public SocketConnectEventArgs(Socket c)
+    public SocketConnectEventArgs(IPAddress address)
     {
-        Connection = c;
+        Address = address;
         AllowConnection = true;
     }
 
-    public Socket Connection { get; }
+    public IPAddress Address { get; }
 
     public bool AllowConnection { get; set; }
 }

Projects/Server/Main.cs

@@ -339,7 +339,7 @@ public static class Core
         World.WaitForWriteCompletion();
         World.ExitSerializationThreads();
         PingServer.Shutdown();
-        TcpServer.Shutdown();
+        NetState.Shutdown();
 
         if (!_crashed)
         {
@@ -447,7 +447,7 @@ public static class Core
 
         AssemblyHandler.Invoke("Initialize");
 
-        TcpServer.Start();
+        NetState.Start();
         PingServer.Start();
         EventSink.InvokeServerStarted();
         RunEventLoop();

Projects/Server/Mobiles/Mobile.cs

@@ -1245,7 +1245,7 @@ public partial class Mobile : IHued, IComparable<Mobile>, ISpawnable, IObjectPro
     {
         get
         {
-            if (m_NetState?.Connection == null)
+            if (m_NetState is not { IsConnected: true })
             {
                 m_NetState = null;
             }

Projects/Server/Network/Encryption/EncryptionConfig.cs

@@ -0,0 +1,45 @@
+/*************************************************************************
+ * ModernUO                                                              *
+ * Copyright 2019-2025 - ModernUO Development Team                       *
+ * Email: hi@modernuo.com                                                *
+ * File: EncryptionConfig.cs                                             *
+ *                                                                       *
+ * This program is free software: you can redistribute it and/or modify  *
+ * it under the terms of the GNU General Public License as published by  *
+ * the Free Software Foundation, either version 3 of the License, or     *
+ * (at your option) any later version.                                   *
+ *                                                                       *
+ * You should have received a copy of the GNU General Public License     *
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>. *
+ *************************************************************************/
+
+using System;
+
+namespace Server.Network;
+
+/// <summary>
+/// Specifies which encryption modes the server will accept.
+/// </summary>
+[Flags]
+public enum EncryptionMode
+{
+    /// <summary>
+    /// Encryption handling is disabled. Current behavior.
+    /// </summary>
+    None = 0x0,
+
+    /// <summary>
+    /// Accept unencrypted clients (e.g., ClassicUO with encryption disabled).
+    /// </summary>
+    Unencrypted = 0x1,
+
+    /// <summary>
+    /// Accept encrypted clients (original UO client, Enhanced Client).
+    /// </summary>
+    Encrypted = 0x2,
+
+    /// <summary>
+    /// Auto-detect and accept both encrypted and unencrypted clients.
+    /// </summary>
+    Both = Unencrypted | Encrypted
+}

Projects/Server/Network/Encryption/EncryptionManager.cs

@@ -0,0 +1,207 @@
+/*************************************************************************
+ * ModernUO                                                              *
+ * Copyright 2019-2025 - ModernUO Development Team                       *
+ * Email: hi@modernuo.com                                                *
+ * File: EncryptionManager.cs                                            *
+ *                                                                       *
+ * This program is free software: you can redistribute it and/or modify  *
+ * it under the terms of the GNU General Public License as published by  *
+ * the Free Software Foundation, either version 3 of the License, or     *
+ * (at your option) any later version.                                   *
+ *                                                                       *
+ * You should have received a copy of the GNU General Public License     *
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>. *
+ *************************************************************************/
+
+using System;
+using System.Buffers.Binary;
+using Server.Logging;
+
+namespace Server.Network;
+
+/// <summary>
+/// Manages encryption detection and configuration for client connections.
+/// </summary>
+public static class EncryptionManager
+{
+    private static readonly ILogger logger = LogFactory.GetLogger(typeof(EncryptionManager));
+
+    private static EncryptionMode _mode = EncryptionMode.None;
+    private static bool _debug;
+
+    /// <summary>
+    /// Gets whether encryption handling is enabled.
+    /// </summary>
+    public static bool Enabled => _mode != EncryptionMode.None;
+
+    /// <summary>
+    /// Gets the current encryption mode.
+    /// </summary>
+    public static EncryptionMode Mode => _mode;
+
+    /// <summary>
+    /// Gets whether debug logging is enabled for encryption.
+    /// </summary>
+    public static bool Debug => _debug;
+
+    /// <summary>
+    /// Configures encryption settings from server configuration.
+    /// </summary>
+    public static void Configure()
+    {
+        _mode = ServerConfiguration.GetSetting("network.encryptionMode", EncryptionMode.Both);
+        _debug = ServerConfiguration.GetSetting("network.encryptionDebug", false);
+
+        if (_mode != EncryptionMode.None)
+        {
+            logger.Information("Encryption support enabled: {Mode}", _mode);
+        }
+    }
+
+    /// <param name="ns">The network state.</param>
+    extension(NetState ns)
+    {
+        /// <summary>
+        /// Detects and initializes encryption for a login packet (0x80).
+        /// </summary>
+        /// <param name="buffer">The 62-byte login packet buffer.</param>
+        /// <param name="encryption">The detected encryption, or null if unencrypted.</param>
+        /// <returns>True if detection succeeded (encrypted or unencrypted), false if rejected.</returns>
+        public bool DetectLoginEncryption(ReadOnlySpan<byte> buffer, out IClientEncryption encryption)
+        {
+            encryption = null;
+
+            if (buffer.Length < 62)
+            {
+                return false;
+            }
+
+            // Check if unencrypted:
+            // - Packet ID is 0x80, OR
+            // - Username and password null terminators are present
+            var isUnencrypted = buffer[0] == 0x80 || buffer[30] == 0x00 && buffer[60] == 0x00;
+
+            if (isUnencrypted)
+            {
+                if (!_mode.HasFlag(EncryptionMode.Unencrypted))
+                {
+                    if (_debug)
+                    {
+                        logger.Debug("Client {Address}: Unencrypted login rejected (mode: {Mode})", ns.Address, _mode);
+                    }
+                    return false;
+                }
+
+                if (_debug)
+                {
+                    logger.Debug("Client {Address}: Unencrypted login detected", ns.Address);
+                }
+
+                return true;
+            }
+
+            // Try encrypted
+            if (!_mode.HasFlag(EncryptionMode.Encrypted))
+            {
+                if (_debug)
+                {
+                    logger.Debug("Client {Address}: Encrypted login rejected (mode: {Mode})", ns.Address, _mode);
+                }
+                return false;
+            }
+
+            // Attempt decryption with version-derived keys
+            if (LoginEncryption.TryDecrypt(ns.Version, (uint)ns.Seed, buffer, out var loginEncryption))
+            {
+                encryption = loginEncryption;
+
+                if (_debug)
+                {
+                    logger.Debug("Client {Address}: Encrypted login detected (version: {Version})", ns.Address, ns.Version);
+                }
+
+                return true;
+            }
+
+            if (_debug)
+            {
+                logger.Debug("Client {Address}: Login encryption detection failed", ns.Address);
+            }
+
+            return false;
+        }
+
+        /// <summary>
+        /// Detects and initializes encryption for a game server login packet (0x91).
+        /// </summary>
+        /// <param name="buffer">The 65-byte game login packet buffer.</param>
+        /// <param name="encryption">The detected encryption, or null if unencrypted.</param>
+        /// <returns>True if detection succeeded (encrypted or unencrypted), false if rejected.</returns>
+        public bool DetectGameEncryption(ReadOnlySpan<byte> buffer, out IClientEncryption encryption)
+        {
+            encryption = null;
+
+            if (buffer.Length < 65)
+            {
+                return false;
+            }
+
+            // Extract auth ID from packet (bytes 1-4, big-endian)
+            var authId = BinaryPrimitives.ReadUInt32BigEndian(buffer[1..]);
+
+            // Check if unencrypted:
+            // - Packet ID is 0x91, OR
+            // - Auth ID equals seed (indicates no encryption applied)
+            var isUnencrypted = buffer[0] == 0x91 || authId == (uint)ns.Seed;
+
+            if (isUnencrypted)
+            {
+                if (!_mode.HasFlag(EncryptionMode.Unencrypted))
+                {
+                    if (_debug)
+                    {
+                        logger.Debug("Client {Address}: Unencrypted game login rejected (mode: {Mode})", ns.Address, _mode);
+                    }
+                    return false;
+                }
+
+                if (_debug)
+                {
+                    logger.Debug("Client {Address}: Unencrypted game login detected", ns.Address);
+                }
+
+                return true;
+            }
+
+            // Try encrypted
+            if (!_mode.HasFlag(EncryptionMode.Encrypted))
+            {
+                if (_debug)
+                {
+                    logger.Debug("Client {Address}: Encrypted game login rejected (mode: {Mode})", ns.Address, _mode);
+                }
+                return false;
+            }
+
+            // Attempt decryption with seed-derived Twofish
+            if (GameEncryption.TryDecrypt((uint)ns.Seed, buffer, out var gameEncryption))
+            {
+                encryption = gameEncryption;
+
+                if (_debug)
+                {
+                    logger.Debug("Client {Address}: Encrypted game login detected (seed: 0x{Seed:X8})", ns.Address, ns.Seed);
+                }
+
+                return true;
+            }
+
+            if (_debug)
+            {
+                logger.Debug("Client {Address}: Game encryption detection failed", ns.Address);
+            }
+
+            return false;
+        }
+    }
+}

Projects/Server/Network/Encryption/GameEncryption.cs

@@ -0,0 +1,204 @@
+/*************************************************************************
+ * ModernUO                                                              *
+ * Copyright 2019-2025 - ModernUO Development Team                       *
+ * Email: hi@modernuo.com                                                *
+ * File: GameEncryption.cs                                               *
+ *                                                                       *
+ * This program is free software: you can redistribute it and/or modify  *
+ * it under the terms of the GNU General Public License as published by  *
+ * the Free Software Foundation, either version 3 of the License, or     *
+ * (at your option) any later version.                                   *
+ *                                                                       *
+ * You should have received a copy of the GNU General Public License     *
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>. *
+ *************************************************************************/
+
+using System;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using System.Runtime.Intrinsics;
+using System.Security.Cryptography;
+using Server.Logging;
+
+namespace Server.Network;
+
+/// <summary>
+/// Implements game packet encryption/decryption using Twofish + MD5.
+/// Used for all game packets after login (0x91 and onwards).
+/// </summary>
+public sealed class GameEncryption : IClientEncryption
+{
+    private static readonly ILogger logger = LogFactory.GetLogger(typeof(GameEncryption));
+
+    private const int CipherTableSize = 256;
+    private const int BlockSize = 16;
+
+    // Static identity table [0..255] for vectorized CopyTo initialization
+    private static readonly byte[] IdentityTable = CreateIdentityTable();
+
+    private static byte[] CreateIdentityTable()
+    {
+        var table = new byte[CipherTableSize];
+        for (var i = 0; i < CipherTableSize; i++)
+        {
+            table[i] = (byte)i;
+        }
+        return table;
+    }
+
+    private readonly TwofishEngine _twofish;
+    private readonly byte[] _cipherTable;
+    private readonly byte[] _xorKey;
+
+    private ushort _recvPos;
+    private byte _sendPos;
+
+    public GameEncryption(uint seed)
+    {
+        // Create 16-byte key from seed (repeated 4 times)
+        Span<byte> key = stackalloc byte[16];
+        key[0] = key[4] = key[8] = key[12] = (byte)((seed >> 24) & 0xFF);
+        key[1] = key[5] = key[9] = key[13] = (byte)((seed >> 16) & 0xFF);
+        key[2] = key[6] = key[10] = key[14] = (byte)((seed >> 8) & 0xFF);
+        key[3] = key[7] = key[11] = key[15] = (byte)(seed & 0xFF);
+
+        _twofish = new TwofishEngine(key);
+
+        // Initialize cipher table with identity [0..255] using vectorized copy
+        _cipherTable = GC.AllocateUninitializedArray<byte>(CipherTableSize);
+        IdentityTable.CopyTo(_cipherTable, 0);
+
+        // Encrypt cipher table with Twofish
+        RefreshCipherTable();
+
+        // Compute MD5 hash of cipher table for server->client XOR key
+        _xorKey = MD5.HashData(_cipherTable);
+    }
+
+    /// <summary>
+    /// Refreshes the cipher table by encrypting it with Twofish.
+    /// Called every 256 bytes of received data.
+    /// </summary>
+    private void RefreshCipherTable()
+    {
+        // Encrypt cipher table in 16-byte blocks
+        for (var i = 0; i < CipherTableSize; i += BlockSize)
+        {
+            _twofish.EncryptBlock(_cipherTable.AsSpan(i, BlockSize));
+        }
+
+        _recvPos = 0;
+    }
+
+    /// <summary>
+    /// Decrypts incoming data from the client (in-place).
+    /// XORs with cipher table, refreshing every 256 bytes.
+    /// </summary>
+    public void ClientDecrypt(Span<byte> buffer)
+    {
+        for (var i = 0; i < buffer.Length; i++)
+        {
+            if (_recvPos >= CipherTableSize)
+            {
+                RefreshCipherTable();
+            }
+
+            buffer[i] ^= _cipherTable[_recvPos++];
+        }
+    }
+
+    /// <summary>
+    /// Encrypts outgoing data to the client (in-place).
+    /// XORs with MD5 hash of cipher table (16-byte rotating key).
+    /// Uses SIMD optimization for larger buffers.
+    /// </summary>
+    public void ServerEncrypt(Span<byte> buffer)
+    {
+        var i = 0;
+
+        // SIMD path: process 16 bytes at a time when aligned with key
+        if (_sendPos == 0 && buffer.Length >= 16 && Vector128.IsHardwareAccelerated)
+        {
+            var keyVec = Vector128.Create(_xorKey);
+
+            for (; i + 16 <= buffer.Length; i += 16)
+            {
+                var chunk = Vector128.LoadUnsafe(ref buffer[i]);
+                var result = Vector128.Xor(chunk, keyVec);
+                result.StoreUnsafe(ref buffer[i]);
+            }
+        }
+
+        // Scalar path for remainder or when not aligned
+        for (; i < buffer.Length; i++)
+        {
+            buffer[i] ^= _xorKey[_sendPos++];
+            _sendPos &= 0x0F; // Wrap at 16
+        }
+    }
+
+    /// <summary>
+    /// Attempts to decrypt a game login packet and validate it.
+    /// Returns true if the packet appears to be validly encrypted.
+    /// </summary>
+    public static bool TryDecrypt(uint seed, ReadOnlySpan<byte> encryptedPacket, out GameEncryption encryption)
+    {
+        const int GameLoginPacketSize = 65;
+
+        encryption = null;
+
+        if (encryptedPacket.Length < GameLoginPacketSize)
+        {
+            if (EncryptionManager.Debug)
+            {
+                logger.Debug("GameEncryption.TryDecrypt: Invalid buffer length {Length}", encryptedPacket.Length);
+            }
+            return false;
+        }
+
+        if (EncryptionManager.Debug)
+        {
+            logger.Debug("GameEncryption.TryDecrypt: Seed=0x{Seed:X8}", seed);
+            logger.Debug("GameEncryption.TryDecrypt: Encrypted[0..16]: {Bytes}", Convert.ToHexString(encryptedPacket[..16]));
+        }
+
+        // Copy and decrypt
+        Span<byte> decrypted = stackalloc byte[GameLoginPacketSize];
+        encryptedPacket[..GameLoginPacketSize].CopyTo(decrypted);
+        var enc = new GameEncryption(seed);
+
+        if (EncryptionManager.Debug)
+        {
+            logger.Debug("GameEncryption.TryDecrypt: CipherTable[0..16]: {Bytes}",
+                Convert.ToHexString(enc._cipherTable.AsSpan(0, 16)));
+            logger.Debug("GameEncryption.TryDecrypt: XorKey: {Bytes}", Convert.ToHexString(enc._xorKey));
+        }
+
+        enc.ClientDecrypt(decrypted);
+
+        if (EncryptionManager.Debug)
+        {
+            logger.Debug("GameEncryption.TryDecrypt: Decrypted[0..16]: {Bytes}", Convert.ToHexString(decrypted[..16]));
+            logger.Debug("GameEncryption.TryDecrypt: First byte=0x{Byte:X2} (expected 0x91)", decrypted[0]);
+        }
+
+        // Validate: first byte must be 0x91 (game server login packet ID)
+        if (decrypted[0] != 0x91)
+        {
+            if (EncryptionManager.Debug)
+            {
+                logger.Debug("GameEncryption.TryDecrypt: Validation FAILED - first byte is not 0x91");
+            }
+            return false;
+        }
+
+        if (EncryptionManager.Debug)
+        {
+            logger.Debug("GameEncryption.TryDecrypt: Validation PASSED");
+        }
+
+        // Re-create encryption for actual use
+        encryption = new GameEncryption(seed);
+        return true;
+    }
+}

Projects/Server/Network/Encryption/IClientEncryption.cs

@@ -0,0 +1,37 @@
+/*************************************************************************
+ * ModernUO                                                              *
+ * Copyright 2019-2025 - ModernUO Development Team                       *
+ * Email: hi@modernuo.com                                                *
+ * File: IClientEncryption.cs                                            *
+ *                                                                       *
+ * This program is free software: you can redistribute it and/or modify  *
+ * it under the terms of the GNU General Public License as published by  *
+ * the Free Software Foundation, either version 3 of the License, or     *
+ * (at your option) any later version.                                   *
+ *                                                                       *
+ * You should have received a copy of the GNU General Public License     *
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>. *
+ *************************************************************************/
+
+using System;
+
+namespace Server.Network;
+
+/// <summary>
+/// Interface for client encryption implementations.
+/// Uses Span-based API for zero-allocation in the hot path.
+/// </summary>
+public interface IClientEncryption
+{
+    /// <summary>
+    /// Decrypts incoming data from the client (in-place).
+    /// </summary>
+    /// <param name="buffer">The buffer containing encrypted data. Modified in-place.</param>
+    void ClientDecrypt(Span<byte> buffer);
+
+    /// <summary>
+    /// Encrypts outgoing data to the client (in-place).
+    /// </summary>
+    /// <param name="buffer">The buffer containing plaintext data. Modified in-place.</param>
+    void ServerEncrypt(Span<byte> buffer);
+}

Projects/Server/Network/Encryption/LoginEncryption.cs

@@ -0,0 +1,123 @@
+/*************************************************************************
+ * ModernUO                                                              *
+ * Copyright 2019-2025 - ModernUO Development Team                       *
+ * Email: hi@modernuo.com                                                *
+ * File: LoginEncryption.cs                                              *
+ *                                                                       *
+ * This program is free software: you can redistribute it and/or modify  *
+ * it under the terms of the GNU General Public License as published by  *
+ * the Free Software Foundation, either version 3 of the License, or     *
+ * (at your option) any later version.                                   *
+ *                                                                       *
+ * You should have received a copy of the GNU General Public License     *
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>. *
+ *************************************************************************/
+
+using System;
+
+namespace Server.Network;
+
+/// <summary>
+/// Implements login packet encryption/decryption using XOR with version-derived keys.
+/// Used for the initial account login packet (0x80).
+/// </summary>
+public sealed class LoginEncryption : IClientEncryption
+{
+    private uint _table1;
+    private uint _table2;
+    private readonly uint _key1;
+    private readonly uint _key2;
+
+    public LoginEncryption(uint seed, LoginKeys keys)
+    {
+        _key1 = keys.Key1;
+        _key2 = keys.Key2;
+
+        // Initialize state tables from seed
+        _table1 = ((~seed ^ 0x00001357) << 16) | ((seed ^ 0xFFFFAAAA) & 0x0000FFFF);
+        _table2 = ((seed ^ 0x43210000) >> 16) | ((~seed ^ 0xABCDFFFF) & 0xFFFF0000);
+    }
+
+    /// <summary>
+    /// Attempts to initialize login encryption and validate the packet.
+    /// Returns true if the packet appears to be validly encrypted with this scheme.
+    /// </summary>
+    public static bool TryDecrypt(
+        ClientVersion version,
+        uint seed,
+        ReadOnlySpan<byte> encryptedPacket,
+        out LoginEncryption encryption)
+    {
+        const int LoginPacketSize = 62;
+
+        encryption = null;
+
+        var keys = LoginKeys.GetKeys(version);
+        if (keys is { Key1: 0, Key2: 0 })
+        {
+            return false;
+        }
+
+        if (encryptedPacket.Length < LoginPacketSize)
+        {
+            return false;
+        }
+
+        // Copy and decrypt
+        Span<byte> decrypted = stackalloc byte[LoginPacketSize];
+        encryptedPacket[..LoginPacketSize].CopyTo(decrypted);
+        var enc = new LoginEncryption(seed, keys);
+        enc.ClientDecrypt(decrypted);
+
+        // Validate decrypted packet structure:
+        // - Byte 0 must be 0x80 (account login packet ID)
+        // - Byte 30 must be 0x00 (null terminator for username)
+        // - Byte 60 must be 0x00 (null terminator for password)
+        if (decrypted[0] != 0x80 || decrypted[30] != 0x00 || decrypted[60] != 0x00)
+        {
+            return false;
+        }
+
+        // Re-initialize encryption state for actual use
+        encryption = new LoginEncryption(seed, keys);
+        return true;
+    }
+
+    /// <summary>
+    /// Decrypts incoming data from the client (in-place).
+    /// </summary>
+    public void ClientDecrypt(Span<byte> buffer)
+    {
+        for (var i = 0; i < buffer.Length; i++)
+        {
+            buffer[i] ^= (byte)(_table1 & 0xFF);
+
+            var edx = _table2;
+            var esi = _table1 << 31;
+            var eax = _table2 >> 1;
+
+            eax |= esi;
+            eax ^= _key1 - 1;
+            edx <<= 31;
+            eax >>= 1;
+
+            var ecx = _table1 >> 1;
+
+            eax |= esi;
+            ecx |= edx;
+            eax ^= _key1;
+            ecx ^= _key2;
+
+            _table1 = ecx;
+            _table2 = eax;
+        }
+    }
+
+    /// <summary>
+    /// Server does not encrypt login responses, so this is a no-op.
+    /// </summary>
+    public void ServerEncrypt(Span<byte> buffer)
+    {
+        // Login encryption is client-to-server only
+    }
+}

Projects/Server/Network/Encryption/LoginKeys.cs

@@ -0,0 +1,89 @@
+/*************************************************************************
+ * ModernUO                                                              *
+ * Copyright 2019-2025 - ModernUO Development Team                       *
+ * Email: hi@modernuo.com                                                *
+ * File: LoginKeys.cs                                                    *
+ *                                                                       *
+ * This program is free software: you can redistribute it and/or modify  *
+ * it under the terms of the GNU General Public License as published by  *
+ * the Free Software Foundation, either version 3 of the License, or     *
+ * (at your option) any later version.                                   *
+ *                                                                       *
+ * You should have received a copy of the GNU General Public License     *
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>. *
+ *************************************************************************/
+
+using System.Collections.Generic;
+using System.Runtime.CompilerServices;
+
+namespace Server.Network;
+
+/// <summary>
+/// Represents encryption keys derived from a client version.
+/// Used for login packet encryption/decryption.
+/// </summary>
+public readonly struct LoginKeys
+{
+    public static readonly LoginKeys Empty = new(0, 0);
+
+    private static readonly Dictionary<ClientVersion, LoginKeys> _cache = [];
+
+    public uint Key1 { get; }
+    public uint Key2 { get; }
+
+    private LoginKeys(uint key1, uint key2)
+    {
+        Key1 = key1;
+        Key2 = key2;
+    }
+
+    /// <summary>
+    /// Gets or computes encryption keys for the specified client version.
+    /// Results are cached for performance.
+    /// </summary>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static LoginKeys GetKeys(ClientVersion version)
+    {
+        if (version == null)
+        {
+            return Empty;
+        }
+
+        if (_cache.TryGetValue(version, out var keys))
+        {
+            return keys;
+        }
+
+        keys = ComputeKeys(version);
+        _cache[version] = keys;
+        return keys;
+    }
+
+    /// <summary>
+    /// Computes encryption keys from client version using the UO key derivation algorithm.
+    /// </summary>
+    private static LoginKeys ComputeKeys(ClientVersion version)
+    {
+        uint major = (uint)version.Major;
+        uint minor = (uint)version.Minor;
+        uint revision = (uint)version.Revision;
+
+        // Key1 derivation
+        uint key1 = (major << 23) | (minor << 14) | (revision << 4);
+        key1 ^= (revision * revision) << 9;
+        key1 ^= minor * minor;
+        key1 ^= (minor * 11) << 24;
+        key1 ^= (revision * 7) << 19;
+        key1 ^= 0x2C13A5FD;
+
+        // Key2 derivation
+        uint key2 = (major << 22) | (revision << 13) | (minor << 3);
+        key2 ^= (revision * revision * 3) << 10;
+        key2 ^= minor * minor;
+        key2 ^= (minor * 13) << 23;
+        key2 ^= (revision * 7) << 18;
+        key2 ^= 0xA31D527F;
+
+        return new LoginKeys(key1, key2);
+    }
+}

Projects/Server/Network/Encryption/TwofishEngine.cs

@@ -0,0 +1,271 @@
+/*************************************************************************
+ * ModernUO                                                              *
+ * Copyright 2019-2025 - ModernUO Development Team                       *
+ * Email: hi@modernuo.com                                                *
+ * File: TwofishEngine.cs                                                *
+ *                                                                       *
+ * This program is free software: you can redistribute it and/or modify  *
+ * it under the terms of the GNU General Public License as published by  *
+ * the Free Software Foundation, either version 3 of the License, or     *
+ * (at your option) any later version.                                   *
+ *                                                                       *
+ * You should have received a copy of the GNU General Public License     *
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>. *
+ *************************************************************************/
+
+using System;
+using System.Numerics;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+namespace Server.Network;
+
+/// <summary>
+/// Twofish block cipher implementation for UO encryption.
+/// Implements 128-bit block encryption with 128-bit key in ECB mode.
+/// Based on the public domain Twofish algorithm by Bruce Schneier et al.
+/// </summary>
+public sealed class TwofishEngine
+{
+    private const int BlockSize = 16; // 128 bits
+    private const int Rounds = 16;
+    private const int InputWhiten = 0;
+    private const int OutputWhiten = 4;
+    private const int RoundSubkeys = 8;
+    private const int TotalSubkeys = RoundSubkeys + 2 * Rounds;
+
+    private const uint SkStep = 0x02020202u;
+    private const uint SkBump = 0x01010101u;
+    private const int SkRotl = 9;
+    private const uint RsGfFdbk = 0x14D;
+    private const int MdsGfFdbk = 0x169;
+
+    // P0 and P1 permutation tables
+    private static readonly byte[] P0 =
+    {
+        0xA9, 0x67, 0xB3, 0xE8, 0x04, 0xFD, 0xA3, 0x76, 0x9A, 0x92, 0x80, 0x78, 0xE4, 0xDD, 0xD1, 0x38,
+        0x0D, 0xC6, 0x35, 0x98, 0x18, 0xF7, 0xEC, 0x6C, 0x43, 0x75, 0x37, 0x26, 0xFA, 0x13, 0x94, 0x48,
+        0xF2, 0xD0, 0x8B, 0x30, 0x84, 0x54, 0xDF, 0x23, 0x19, 0x5B, 0x3D, 0x59, 0xF3, 0xAE, 0xA2, 0x82,
+        0x63, 0x01, 0x83, 0x2E, 0xD9, 0x51, 0x9B, 0x7C, 0xA6, 0xEB, 0xA5, 0xBE, 0x16, 0x0C, 0xE3, 0x61,
+        0xC0, 0x8C, 0x3A, 0xF5, 0x73, 0x2C, 0x25, 0x0B, 0xBB, 0x4E, 0x89, 0x6B, 0x53, 0x6A, 0xB4, 0xF1,
+        0xE1, 0xE6, 0xBD, 0x45, 0xE2, 0xF4, 0xB6, 0x66, 0xCC, 0x95, 0x03, 0x56, 0xD4, 0x1C, 0x1E, 0xD7,
+        0xFB, 0xC3, 0x8E, 0xB5, 0xE9, 0xCF, 0xBF, 0xBA, 0xEA, 0x77, 0x39, 0xAF, 0x33, 0xC9, 0x62, 0x71,
+        0x81, 0x79, 0x09, 0xAD, 0x24, 0xCD, 0xF9, 0xD8, 0xE5, 0xC5, 0xB9, 0x4D, 0x44, 0x08, 0x86, 0xE7,
+        0xA1, 0x1D, 0xAA, 0xED, 0x06, 0x70, 0xB2, 0xD2, 0x41, 0x7B, 0xA0, 0x11, 0x31, 0xC2, 0x27, 0x90,
+        0x20, 0xF6, 0x60, 0xFF, 0x96, 0x5C, 0xB1, 0xAB, 0x9E, 0x9C, 0x52, 0x1B, 0x5F, 0x93, 0x0A, 0xEF,
+        0x91, 0x85, 0x49, 0xEE, 0x2D, 0x4F, 0x8F, 0x3B, 0x47, 0x87, 0x6D, 0x46, 0xD6, 0x3E, 0x69, 0x64,
+        0x2A, 0xCE, 0xCB, 0x2F, 0xFC, 0x97, 0x05, 0x7A, 0xAC, 0x7F, 0xD5, 0x1A, 0x4B, 0x0E, 0xA7, 0x5A,
+        0x28, 0x14, 0x3F, 0x29, 0x88, 0x3C, 0x4C, 0x02, 0xB8, 0xDA, 0xB0, 0x17, 0x55, 0x1F, 0x8A, 0x7D,
+        0x57, 0xC7, 0x8D, 0x74, 0xB7, 0xC4, 0x9F, 0x72, 0x7E, 0x15, 0x22, 0x12, 0x58, 0x07, 0x99, 0x34,
+        0x6E, 0x50, 0xDE, 0x68, 0x65, 0xBC, 0xDB, 0xF8, 0xC8, 0xA8, 0x2B, 0x40, 0xDC, 0xFE, 0x32, 0xA4,
+        0xCA, 0x10, 0x21, 0xF0, 0xD3, 0x5D, 0x0F, 0x00, 0x6F, 0x9D, 0x36, 0x42, 0x4A, 0x5E, 0xC1, 0xE0
+    };
+
+    private static readonly byte[] P1 =
+    {
+        0x75, 0xF3, 0xC6, 0xF4, 0xDB, 0x7B, 0xFB, 0xC8, 0x4A, 0xD3, 0xE6, 0x6B, 0x45, 0x7D, 0xE8, 0x4B,
+        0xD6, 0x32, 0xD8, 0xFD, 0x37, 0x71, 0xF1, 0xE1, 0x30, 0x0F, 0xF8, 0x1B, 0x87, 0xFA, 0x06, 0x3F,
+        0x5E, 0xBA, 0xAE, 0x5B, 0x8A, 0x00, 0xBC, 0x9D, 0x6D, 0xC1, 0xB1, 0x0E, 0x80, 0x5D, 0xD2, 0xD5,
+        0xA0, 0x84, 0x07, 0x14, 0xB5, 0x90, 0x2C, 0xA3, 0xB2, 0x73, 0x4C, 0x54, 0x92, 0x74, 0x36, 0x51,
+        0x38, 0xB0, 0xBD, 0x5A, 0xFC, 0x60, 0x62, 0x96, 0x6C, 0x42, 0xF7, 0x10, 0x7C, 0x28, 0x27, 0x8C,
+        0x13, 0x95, 0x9C, 0xC7, 0x24, 0x46, 0x3B, 0x70, 0xCA, 0xE3, 0x85, 0xCB, 0x11, 0xD0, 0x93, 0xB8,
+        0xA6, 0x83, 0x20, 0xFF, 0x9F, 0x77, 0xC3, 0xCC, 0x03, 0x6F, 0x08, 0xBF, 0x40, 0xE7, 0x2B, 0xE2,
+        0x79, 0x0C, 0xAA, 0x82, 0x41, 0x3A, 0xEA, 0xB9, 0xE4, 0x9A, 0xA4, 0x97, 0x7E, 0xDA, 0x7A, 0x17,
+        0x66, 0x94, 0xA1, 0x1D, 0x3D, 0xF0, 0xDE, 0xB3, 0x0B, 0x72, 0xA7, 0x1C, 0xEF, 0xD1, 0x53, 0x3E,
+        0x8F, 0x33, 0x26, 0x5F, 0xEC, 0x76, 0x2A, 0x49, 0x81, 0x88, 0xEE, 0x21, 0xC4, 0x1A, 0xEB, 0xD9,
+        0xC5, 0x39, 0x99, 0xCD, 0xAD, 0x31, 0x8B, 0x01, 0x18, 0x23, 0xDD, 0x1F, 0x4E, 0x2D, 0xF9, 0x48,
+        0x4F, 0xF2, 0x65, 0x8E, 0x78, 0x5C, 0x58, 0x19, 0x8D, 0xE5, 0x98, 0x57, 0x67, 0x7F, 0x05, 0x64,
+        0xAF, 0x63, 0xB6, 0xFE, 0xF5, 0xB7, 0x3C, 0xA5, 0xCE, 0xE9, 0x68, 0x44, 0xE0, 0x4D, 0x43, 0x69,
+        0x29, 0x2E, 0xAC, 0x15, 0x59, 0xA8, 0x0A, 0x9E, 0x6E, 0x47, 0xDF, 0x34, 0x35, 0x6A, 0xCF, 0xDC,
+        0x22, 0xC9, 0xC0, 0x9B, 0x89, 0xD4, 0xED, 0xAB, 0x12, 0xA2, 0x0D, 0x52, 0xBB, 0x02, 0x2F, 0xA9,
+        0xD7, 0x61, 0x1E, 0xB4, 0x50, 0x04, 0xF6, 0xC2, 0x16, 0x25, 0x86, 0x56, 0x55, 0x09, 0xBE, 0x91
+    };
+
+    private readonly uint[] _sboxKeys = new uint[2]; // For 128-bit key
+    private readonly uint[] _subKeys = new uint[TotalSubkeys];
+
+    /// <summary>
+    /// Creates a new Twofish engine with the specified 128-bit key.
+    /// </summary>
+    public TwofishEngine(ReadOnlySpan<byte> key)
+    {
+        if (key.Length != 16)
+        {
+            throw new ArgumentException("Key must be 16 bytes (128 bits)", nameof(key));
+        }
+
+        GenerateSubkeys(MemoryMarshal.Cast<byte, uint>(key));
+    }
+
+    private void GenerateSubkeys(ReadOnlySpan<uint> keyWords)
+    {
+        // Split key into even and odd words
+        var k0 = keyWords[0];
+        var k1 = keyWords[1];
+        var k2 = keyWords[2];
+        var k3 = keyWords[3];
+
+        // Compute S-box keys using RS matrix
+        _sboxKeys[0] = RsMdsEncode(k2, k3);
+        _sboxKeys[1] = RsMdsEncode(k0, k1);
+
+        // Generate round subkeys
+        for (var i = 0; i < TotalSubkeys / 2; i++)
+        {
+            var a = F32((uint)(i * SkStep), k0, k2);
+            var b = F32((uint)(i * SkStep + SkBump), k1, k3);
+            b = BitOperations.RotateLeft(b, 8);
+
+            _subKeys[2 * i] = a + b;
+            _subKeys[2 * i + 1] = BitOperations.RotateLeft(a + 2 * b, SkRotl);
+        }
+    }
+
+    /// <summary>
+    /// Encrypts a 16-byte block in place.
+    /// </summary>
+    public void EncryptBlock(Span<byte> block)
+    {
+        if (block.Length < BlockSize)
+        {
+            throw new ArgumentException("Block must be at least 16 bytes", nameof(block));
+        }
+
+        var x = MemoryMarshal.Cast<byte, uint>(block);
+
+        // Input whitening
+        x[0] ^= _subKeys[InputWhiten];
+        x[1] ^= _subKeys[InputWhiten + 1];
+        x[2] ^= _subKeys[InputWhiten + 2];
+        x[3] ^= _subKeys[InputWhiten + 3];
+
+        // 16 rounds
+        for (var r = 0; r < Rounds; r++)
+        {
+            var t0 = F32Sbox(x[0]);
+            var t1 = F32Sbox(BitOperations.RotateLeft(x[1], 8));
+
+            x[3] = BitOperations.RotateLeft(x[3], 1);
+            x[2] ^= t0 + t1 + _subKeys[RoundSubkeys + 2 * r];
+            x[3] ^= t0 + 2 * t1 + _subKeys[RoundSubkeys + 2 * r + 1];
+            x[2] = BitOperations.RotateRight(x[2], 1);
+
+            if (r < Rounds - 1)
+            {
+                // Swap for next round
+                (x[0], x[2]) = (x[2], x[0]);
+                (x[1], x[3]) = (x[3], x[1]);
+            }
+        }
+
+        // Output whitening
+        x[0] ^= _subKeys[OutputWhiten];
+        x[1] ^= _subKeys[OutputWhiten + 1];
+        x[2] ^= _subKeys[OutputWhiten + 2];
+        x[3] ^= _subKeys[OutputWhiten + 3];
+    }
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private uint F32Sbox(uint x)
+    {
+        // For 128-bit key, use 2 S-box keys
+        // Permutation sequence from Twofish spec (P_ij constants):
+        // b0: P0[P0[P0[x]^k1]^k0] then P1 final
+        // b1: P0[P0[P1[x]^k1]^k0] then P0 final
+        // b2: P1[P1[P0[x]^k1]^k0] then P1 final
+        // b3: P1[P1[P1[x]^k1]^k0] then P0 final
+
+        var b0 = (byte)x;
+        var b1 = (byte)(x >> 8);
+        var b2 = (byte)(x >> 16);
+        var b3 = (byte)(x >> 24);
+
+        var k0 = _sboxKeys[0];
+        var k1 = _sboxKeys[1];
+
+        // First layer: P_02=0(P0), P_12=1(P1), P_22=0(P0), P_32=1(P1)
+        b0 = (byte)(P0[b0] ^ (byte)k1);
+        b1 = (byte)(P1[b1] ^ (byte)(k1 >> 8));
+        b2 = (byte)(P0[b2] ^ (byte)(k1 >> 16));
+        b3 = (byte)(P1[b3] ^ (byte)(k1 >> 24));
+
+        // Second layer: P_01=0(P0), P_11=0(P0), P_21=1(P1), P_31=1(P1)
+        b0 = (byte)(P0[b0] ^ (byte)k0);
+        b1 = (byte)(P0[b1] ^ (byte)(k0 >> 8));
+        b2 = (byte)(P1[b2] ^ (byte)(k0 >> 16));
+        b3 = (byte)(P1[b3] ^ (byte)(k0 >> 24));
+
+        // Final layer: P_00=1(P1), P_10=0(P0), P_20=1(P1), P_30=0(P0)
+        // MDS matrix multiply
+        return MdsMultiply(P1[b0], P0[b1], P1[b2], P0[b3]);
+    }
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private static uint F32(uint x, uint k0, uint k2)
+    {
+        var b0 = (byte)x;
+        var b1 = (byte)(x >> 8);
+        var b2 = (byte)(x >> 16);
+        var b3 = (byte)(x >> 24);
+
+        // First layer: P_02=0(P0), P_12=1(P1), P_22=0(P0), P_32=1(P1)
+        b0 = (byte)(P0[b0] ^ (byte)k2);
+        b1 = (byte)(P1[b1] ^ (byte)(k2 >> 8));
+        b2 = (byte)(P0[b2] ^ (byte)(k2 >> 16));
+        b3 = (byte)(P1[b3] ^ (byte)(k2 >> 24));
+
+        // Second layer: P_01=0(P0), P_11=0(P0), P_21=1(P1), P_31=1(P1)
+        b0 = (byte)(P0[b0] ^ (byte)k0);
+        b1 = (byte)(P0[b1] ^ (byte)(k0 >> 8));
+        b2 = (byte)(P1[b2] ^ (byte)(k0 >> 16));
+        b3 = (byte)(P1[b3] ^ (byte)(k0 >> 24));
+
+        // Final layer: P_00=1(P1), P_10=0(P0), P_20=1(P1), P_30=0(P0)
+        return MdsMultiply(P1[b0], P0[b1], P1[b2], P0[b3]);
+    }
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private static uint MdsMultiply(byte b0, byte b1, byte b2, byte b3)
+    {
+        // MDS matrix multiplication (Galois Field 2^8)
+        var m0 = (uint)(b0 ^ Lfsr2(b1) ^ Lfsr1(b2) ^ Lfsr1(b3));
+        var m1 = (uint)(Lfsr1(b0) ^ Lfsr2(b1) ^ Lfsr2(b2) ^ b3);
+        var m2 = (uint)(Lfsr2(b0) ^ Lfsr1(b1) ^ b2 ^ Lfsr2(b3));
+        var m3 = (uint)(Lfsr2(b0) ^ b1 ^ Lfsr2(b2) ^ Lfsr1(b3));
+
+        return m0 | (m1 << 8) | (m2 << 16) | (m3 << 24);
+    }
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private static int Lfsr1(int val) => val ^ Lfsr4(val);
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private static int Lfsr2(int val) => val ^ Lfsr3(val) ^ Lfsr4(val);
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private static int Lfsr3(int val) => (val >> 1) ^ ((val & 0x01) == 0x01 ? MdsGfFdbk / 2 : 0);
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private static int Lfsr4(int val) =>
+        (val >> 2) ^ ((val & 0x02) == 0x02 ? MdsGfFdbk / 2 : 0) ^ ((val & 0x01) == 0x01 ? MdsGfFdbk / 4 : 0);
+
+    private static uint RsMdsEncode(uint k0, uint k1)
+    {
+        uint r = 0;
+        for (var i = 0; i < 2; i++)
+        {
+            r ^= i > 0 ? k0 : k1;
+
+            for (var j = 0; j < 4; j++)
+            {
+                var v1 = (byte)(r >> 24);
+                var v2 = (uint)(((v1 << 1) ^ ((v1 & 0x80) == 0x80 ? RsGfFdbk : 0)) & 0xFF);
+                var v3 = (uint)(((v1 >> 1) & 0x7F) ^ ((v1 & 1) == 1 ? RsGfFdbk >> 1 : 0) ^ v2);
+
+                r = (r << 8) ^ (v3 << 24) ^ (v2 << 16) ^ (v3 << 8) ^ v1;
+            }
+        }
+
+        return r;
+    }
+}

Projects/Server/Network/NetState/DumpNetStates.cs

@@ -32,7 +32,7 @@ public static class DumpNetStates
 
         foreach (var ns in NetState.Instances)
         {
-            file.WriteLine($"{ns}, {ns.ConnectedOn}, {ns.NextActivityCheck}, {ns.Connection.Connected}, {ns._protocolState}, {ns._parserState}");
+            file.WriteLine($"{ns}, {ns.ConnectedOn}, {ns.NextActivityCheck}, {ns.IsConnected}, {ns._protocolState}, {ns._parserState}");
         }
     }
 }

Projects/Server/Network/NetState/NetState.Network.cs

@@ -0,0 +1,498 @@
+/*************************************************************************
+ * ModernUO                                                              *
+ * Copyright 2019-2025 - ModernUO Development Team                       *
+ * Email: hi@modernuo.com                                                *
+ * File: NetState.Network.cs                                             *
+ *                                                                       *
+ * This program is free software: you can redistribute it and/or modify  *
+ * it under the terms of the GNU General Public License as published by  *
+ * the Free Software Foundation, either version 3 of the License, or     *
+ * (at your option) any later version.                                   *
+ *                                                                       *
+ * You should have received a copy of the GNU General Public License     *
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.  *
+ *************************************************************************/
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net;
+using System.Net.NetworkInformation;
+using System.Network;
+
+namespace Server.Network;
+
+/// <summary>
+/// Network infrastructure for IORingGroup-based socket I/O.
+/// </summary>
+public partial class NetState
+{
+    // Buffer sizes
+    private const int RecvBufferSize = 1024 * 64;   // 64KB recv buffers
+    private const int SendBufferSize = 1024 * 256;  // 256KB send buffers
+    private const int MaxConnections = 4096;        // Max concurrent connections
+
+    // Socket manager handles buffer pools, socket lifecycle, and I/O operations
+    private static RingSocketManager _socketManager;
+
+    // NetState storage indexed by RingSocket.Id
+    private static readonly NetState[] _netStates = new NetState[MaxConnections];
+
+    // Events buffer for ProcessCompletions
+    private static readonly RingSocketEvent[] _events = new RingSocketEvent[MaxConnections * 2];
+
+    // Listener management
+    private static nint[] _listeners = Array.Empty<nint>();
+    private static int _pendingAcceptCount;
+    private const int PendingAcceptsPerListener = 32;
+
+    /// <summary>
+    /// Gets the IORingGroup instance for socket operations.
+    /// </summary>
+    public static IIORingGroup Ring => _socketManager?.Ring;
+
+    /// <summary>
+    /// Gets the listening addresses that the server is bound to.
+    /// </summary>
+    public static IPEndPoint[] ListeningAddresses { get; private set; }
+
+    private static IPRateLimiter _ipRateLimiter;
+
+    /// <summary>
+    /// Configures the IORingGroup and socket manager.
+    /// </summary>
+    private static void ConfigureNetwork()
+    {
+        // Skip if already configured
+        if (_socketManager != null)
+        {
+            return;
+        }
+
+        // Initialize IP rate limiter
+        _ipRateLimiter = new IPRateLimiter(10, 10000, 1000, 2.0, 3_600_000, Core.ClosingTokenSource.Token);
+
+        // Initialize IORingGroup
+        var ring = IORingGroup.Create(queueSize: MaxConnections * 2, maxConnections: MaxConnections);
+
+        // Create socket manager which handles buffer pools and socket lifecycle
+        _socketManager = new RingSocketManager(
+            ring,
+            maxSockets: MaxConnections,
+            recvBufferSize: RecvBufferSize,
+            sendBufferSize: SendBufferSize,
+            initialBufferSlabs: 8,
+            maxBufferSlabs: 32
+        );
+    }
+
+    /// <summary>
+    /// Starts the network server on configured listening addresses.
+    /// </summary>
+    public static void Start()
+    {
+        HashSet<IPEndPoint> listeningAddresses = [];
+        List<nint> listeners = [];
+
+        var ring = _socketManager.Ring;
+        for (var i = 0; i < ServerConfiguration.Listeners.Count; i++)
+        {
+            var ipep = ServerConfiguration.Listeners[i];
+            var listener = ring.CreateListener(ipep.Address.ToString(), (ushort)ipep.Port, 256);
+            if (listener == -1)
+            {
+                logger.Warning("Failed to create listener for {Address}", ipep);
+                continue;
+            }
+
+            if (ipep.Address.Equals(IPAddress.Any) || ipep.Address.Equals(IPAddress.IPv6Any))
+            {
+                listeningAddresses.UnionWith(GetListeningAddresses(ipep));
+            }
+            else
+            {
+                listeningAddresses.Add(ipep);
+            }
+
+            listeners.Add(listener);
+        }
+
+        foreach (var ipep in listeningAddresses)
+        {
+            logger.Information("Listening: {Address}", ipep);
+        }
+
+        ListeningAddresses = listeningAddresses.ToArray();
+
+        // Register listeners to start accepting connections
+        RegisterListeners(listeners.ToArray());
+    }
+
+    /// <summary>
+    /// Shuts down the network server and closes all listeners.
+    /// </summary>
+    public static void Shutdown()
+    {
+        CloseListeners();
+    }
+
+    /// <summary>
+    /// Gets the actual listening addresses for a wildcard endpoint.
+    /// </summary>
+    public static IEnumerable<IPEndPoint> GetListeningAddresses(IPEndPoint ipep) =>
+        NetworkInterface.GetAllNetworkInterfaces().SelectMany(adapter =>
+            adapter.GetIPProperties().UnicastAddresses
+                .Where(uip => ipep.AddressFamily == uip.Address.AddressFamily)
+                .Select(uip => new IPEndPoint(uip.Address, ipep.Port))
+        );
+
+    /// <summary>
+    /// Registers listeners with the ring and starts accepting connections.
+    /// </summary>
+    private static void RegisterListeners(nint[] listeners)
+    {
+        _listeners = listeners;
+
+        var ring = _socketManager.Ring;
+
+        // Queue initial accept operations for each listener
+        for (var i = 0; i < _listeners.Length; i++)
+        {
+            var listener = _listeners[i];
+            for (var j = 0; j < PendingAcceptsPerListener; j++)
+            {
+                ring.PrepareAccept(listener, 0, 0, IORingUserData.EncodeAccept());
+                _pendingAcceptCount++;
+            }
+        }
+    }
+
+    /// <summary>
+    /// Closes all listeners.
+    /// </summary>
+    private static void CloseListeners()
+    {
+        var ring = _socketManager?.Ring;
+        if (ring == null)
+        {
+            return;
+        }
+
+        foreach (var listener in _listeners)
+        {
+            ring.CloseListener(listener);
+        }
+
+        _listeners = [];
+    }
+
+    private static void HandleAcceptCompletion(int result)
+    {
+        _pendingAcceptCount--;
+
+        var ring = _socketManager.Ring;
+
+        // EAGAIN (-11) means no connection pending - just re-queue
+        if (result == -11)
+        {
+            goto ReplenishAccepts;
+        }
+
+        if (result >= 0)
+        {
+            var clientSocket = (nint)result;
+            var remoteIP = SocketHelper.GetRemoteAddress(clientSocket);
+
+            if (remoteIP != null)
+            {
+                if (_ipRateLimiter != null && !_ipRateLimiter.Verify(remoteIP, out var totalAttempts))
+                {
+                    logger.Debug("{Address} Past IP limit threshold ({TotalAttempts})", remoteIP, totalAttempts);
+                }
+                else if (Firewall.IsBlocked(remoteIP))
+                {
+                    logger.Debug("{Address} Firewalled", remoteIP);
+                }
+                else
+                {
+                    // Allow event handlers to reject the connection
+                    var args = new SocketConnectEventArgs(remoteIP);
+                    EventSink.InvokeSocketConnect(args);
+
+                    if (args.AllowConnection)
+                    {
+                        ring.ConfigureSocket(clientSocket);
+                        CreateFromSocket(clientSocket, remoteIP);
+                        goto ReplenishAccepts;
+                    }
+
+                    logger.Debug("{Address} Rejected by socket handler", remoteIP);
+                }
+            }
+
+            ring.CloseSocket(clientSocket);
+        }
+        else if (result != -4) // EINTR
+        {
+            logger.Debug("Accept error: {Result}", result);
+        }
+
+        ReplenishAccepts:
+        var targetAccepts = _listeners.Length * PendingAcceptsPerListener;
+        while (_pendingAcceptCount < targetAccepts && _listeners.Length > 0)
+        {
+            var listenerIndex = _pendingAcceptCount % _listeners.Length;
+            ring.PrepareAccept(_listeners[listenerIndex], 0, 0, IORingUserData.EncodeAccept());
+            _pendingAcceptCount++;
+        }
+    }
+
+    /// <summary>
+    /// Creates a NetState from an accepted socket handle.
+    /// </summary>
+    internal static NetState CreateFromSocket(nint socketHandle, IPAddress address)
+    {
+        // Use socket manager to create managed socket (handles buffers, registration, recv posting)
+        var socket = _socketManager.CreateSocket(socketHandle);
+        if (socket == null)
+        {
+            logger.Debug("Failed to create socket (resources exhausted)");
+            _socketManager.Ring.CloseSocket(socketHandle);
+            return null;
+        }
+
+        // Create NetState and map by socket ID
+        var ns = new NetState(socket, address);
+        return _netStates[socket.Id] = ns;
+    }
+
+    private static void DisconnectUnattachedSockets()
+    {
+        var now = Core.Now;
+
+        // Process connecting queue with lazy removal - O(1) operations
+        while (_connectingQueue.TryPeek(out var ns))
+        {
+            // Lazy removal: skip already-authenticated or disconnected connections
+            if (!ns.Running || ns.Account != null)
+            {
+                _connectingQueue.Dequeue();
+                continue;
+            }
+
+            // If the socket has been connected for less than the limit, we can stop
+            // (queue is ordered by connection time, so remaining entries are newer)
+            if (now - ns.ConnectedOn < ConnectingSocketIdleLimit)
+            {
+                break;
+            }
+
+            _connectingQueue.Dequeue();
+
+            // Socket must have finished the entire authentication process or be forcibly disconnected
+            if (!ns.SentFirstPacket || !ns.Seeded)
+            {
+                ns.Disconnect(null);
+            }
+        }
+    }
+
+    public static void FlushAll()
+    {
+        while (_flushPending.TryDequeue(out var ns))
+        {
+            if (ns == null)
+            {
+                continue;
+            }
+
+            // Reset flag to allow re-queueing if more data is added later
+            ns._flushQueued = false;
+
+            if (ns.Running)
+            {
+                ns._socket?.QueueSend();
+            }
+        }
+
+        // Submit any pending operations
+        _socketManager?.Submit();
+    }
+
+    public static void Slice()
+    {
+        DisconnectUnattachedSockets();
+
+        // Process throttled states
+        while (_throttled.Count > 0)
+        {
+            var ns = _throttled.Dequeue();
+            if (ns.Running)
+            {
+                ns.HandleReceive(true);
+            }
+        }
+
+        // This is enqueued by HandleReceive if already throttled and still throttled
+        while (_throttledPending.Count > 0)
+        {
+            _throttled.Enqueue(_throttledPending.Dequeue());
+        }
+
+        // Process all completions through the manager FIRST
+        // This ensures DataReceived events are processed and HandleReceive runs,
+        // which may call Send() and add to _flushPending
+        var eventCount = _socketManager.ProcessCompletions(_events);
+
+        for (var i = 0; i < eventCount; i++)
+        {
+            ref var evt = ref _events[i];
+
+            switch (evt.Type)
+            {
+                case RingSocketEventType.Accept:
+                    {
+                        // Handle accept - AcceptedSocketHandle contains the result
+                        HandleAcceptCompletion((int)evt.AcceptedSocketHandle);
+                        break;
+                    }
+
+                case RingSocketEventType.DataReceived:
+                    {
+                        var nsRecv = _netStates[evt.Socket.Id];
+                        // Verify generation via object identity to avoid stale completion issues
+                        if (nsRecv != null && nsRecv._socket == evt.Socket)
+                        {
+                            HandleDataReceived(nsRecv, evt.BytesTransferred);
+                        }
+                        break;
+                    }
+
+                case RingSocketEventType.DataSent:
+                    {
+                        var nsSend = _netStates[evt.Socket.Id];
+                        // Verify generation via object identity
+                        if (nsSend != null && nsSend._socket == evt.Socket)
+                        {
+                            // Update activity check on successful send
+                            nsSend.NextActivityCheck = Core.TickCount + 90000;
+                        }
+                        break;
+                    }
+
+                case RingSocketEventType.Disconnected:
+                    {
+                        var nsDisc = _netStates[evt.Socket.Id];
+                        // Verify generation via object identity
+                        if (nsDisc != null && nsDisc._socket == evt.Socket)
+                        {
+                            HandleDisconnected(nsDisc);
+                        }
+                        break;
+                    }
+            }
+        }
+
+        // Process flush queue AFTER event processing
+        // This ensures sends triggered by HandleReceive (via packet handlers like SendPlayServerAck)
+        // are queued in the SAME Slice, not the next one
+        while (_flushPending.TryDequeue(out var ns))
+        {
+            // Reset flag to allow re-queueing if more data is added later
+            ns._flushQueued = false;
+
+            if (ns.Running)
+            {
+                ns._socket?.QueueSend();
+            }
+        }
+
+        // CRITICAL: Process send queue NOW to post pending sends
+        // This ensures PostSend() runs and sets SendPending=true BEFORE disconnect checks
+        // Without this, Disconnect() would see SendPending=false even though data is queued
+        _socketManager.ProcessSendQueue();
+
+        // Process pending disconnects AFTER flush queue AND send queue processing
+        // This ensures the traditional order: Game Logic (Sends/Disconnects) → Receives → Flush → Disconnect
+        // Any Send() calls made after Disconnect() in the same tick are flushed before disconnect
+        while (_pendingDisconnects.TryDequeue(out var ns))
+        {
+            // Reset flag to allow re-queueing if reconnect happens
+            ns._disconnectQueued = false;
+
+            if (ns.Running && ns._socket != null)
+            {
+                // RingSocket.Disconnect() handles graceful disconnect:
+                // - Waits for pending sends to flush (if SendBuffer.ReadableBytes > 0)
+                // - Waits for in-flight I/O to complete
+                // - Ensures buffers aren't released while kernel is still using them
+                ns._socket.Disconnect();
+            }
+        }
+
+        // Submit any queued operations
+        _socketManager.Submit();
+
+        // Process disposes
+        while (_disposed.TryDequeue(out var ns))
+        {
+            ns.Dispose();
+        }
+    }
+
+    private static void HandleDataReceived(NetState ns, int bytesReceived)
+    {
+        if (!ns._running)
+        {
+            return;
+        }
+
+        // Data is already committed to buffer by RingSocketManager
+        // Decode if encryption is enabled
+        ns.DecryptRecvBuffer(bytesReceived);
+
+        // Process packets
+        ns.HandleReceive();
+    }
+
+    private static void HandleDisconnected(NetState ns)
+    {
+        var slotId = ns._socket.Id;
+
+        // IMPORTANT: Check if the slot still points to this NetState
+        // During quick reconnect, the slot might have been reused for a new connection
+        var currentNs = _netStates[slotId];
+        if (currentNs != ns)
+        {
+            // Slot was already reused - don't clear it!
+            // Just mark this NetState as not running and queue for dispose
+            ns._running = false;
+            _disposed.Enqueue(ns);
+            return;
+        }
+
+        // Clear the NetState slot
+        _netStates[slotId] = null;
+
+        // Mark as not running and queue for dispose
+        ns._running = false;
+        _disposed.Enqueue(ns);
+    }
+
+    public static void CheckAllAlive()
+    {
+        try
+        {
+            var curTicks = Core.TickCount;
+
+            foreach (var ns in Instances)
+            {
+                ns.CheckAlive(curTicks);
+            }
+        }
+        catch (Exception ex)
+        {
+            TraceException(ex);
+        }
+    }
+}

Projects/Server/Network/NetState/NetState.cs

@@ -1,6 +1,6 @@
 /*************************************************************************
  * ModernUO                                                              *
- * Copyright 2019-2023 - ModernUO Development Team                       *
+ * Copyright 2019-2025 - ModernUO Development Team                       *
  * Email: hi@modernuo.com                                                *
  * File: NetState.cs                                                     *
  *                                                                       *
@@ -25,55 +25,46 @@ using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.IO;
 using System.Net;
-using System.Net.Sockets;
 using System.Network;
 using System.Runtime.CompilerServices;
-using System.Runtime.InteropServices;
 
 namespace Server.Network;
 
-public delegate void DecodePacket(Span<byte> buffer, ref int length);
-public delegate int EncodePacket(ReadOnlySpan<byte> inputBuffer, Span<byte> outputBuffer);
-
 public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetState>, IDisposable
 {
     private static readonly ILogger logger = LogFactory.GetLogger(typeof(NetState));
 
     private static readonly TimeSpan ConnectingSocketIdleLimit = TimeSpan.FromMilliseconds(5000); // 5 seconds
-    private const int RecvPipeSize = 1024 * 64;
-    private const int SendPipeSize = 1024 * 256;
     private const int HuePickerCap = 512;
     private const int MenuCap = 512;
     private const int PacketPerSecondThreshold = 3000;
 
-    private static readonly GCHandle[] _polledStates = new GCHandle[2048];
-    private static readonly IPollGroup _pollGroup = PollGroup.Create();
     private static readonly Queue<NetState> _flushPending = new(2048);
-    private static readonly Queue<NetState> _flushedPartials = new(256);
+    private static readonly Queue<NetState> _pendingDisconnects = new(256); // Processed AFTER flush
     private static readonly ConcurrentQueue<NetState> _disposed = new();
     private static readonly Queue<NetState> _throttled = new(256);
     private static readonly Queue<NetState> _throttledPending = new(256);
 
-    private static readonly SortedSet<NetState> _connecting = new(NetStateConnectingComparer.Instance);
+    private static readonly Queue<NetState> _connectingQueue = new(2048);
     private static readonly HashSet<NetState> _instances = new(2048);
     public static IReadOnlySet<NetState> Instances => _instances;
 
     private readonly string _toString;
     private ClientVersion _version;
     private bool _running = true;
-    private volatile DecodePacket _packetDecoder;
-    private volatile EncodePacket _packetEncoder;
+    private IClientEncryption _encryption;
     private bool _flushQueued;
+    private bool _disconnectQueued; // Queued for disconnect processing (after flush)
     private long[] _packetThrottles;
     private long[] _packetCounts;
     private string _disconnectReason = string.Empty;
 
     internal ParserState _parserState = ParserState.AwaitingNextPacket;
     internal ProtocolState _protocolState = ProtocolState.AwaitingSeed;
-    internal GCHandle _handle;
     private bool _packetLogging;
 
-    public GCHandle Handle => _handle;
+    // Managed socket with buffers (handles lifecycle automatically)
+    internal RingSocket _socket;
 
     // Speed Hack Prevention
     internal long _movementCredit;
@@ -108,6 +99,9 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
     public static void Configure()
     {
         _packetLoggingPath = ServerConfiguration.GetSetting("netstate.packetLoggingPath", Path.Combine(Core.BaseDirectory, "Packets"));
+
+        // Initialize IORingGroup and buffer pools
+        ConfigureNetwork();
     }
 
     public static void Initialize()
@@ -115,45 +109,24 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
         Timer.DelayCall(TimeSpan.FromMinutes(1), TimeSpan.FromMinutes(1.5), CheckAllAlive);
     }
 
-    public NetState(Socket connection)
+    // Internal constructor for accepted sockets
+    private NetState(RingSocket socket, IPAddress address)
     {
-        Connection = connection;
+        _socket = socket;
+        Address = address;
+
         Seeded = false;
         HuePickers = [];
         Menus = [];
         Trades = [];
-        RecvPipe = new Pipe(RecvPipeSize);
-        SendPipe = new Pipe(SendPipeSize);
         NextActivityCheck = Core.TickCount + 30000;
         ConnectedOn = Core.Now;
-
-        try
-        {
-            Address = Utility.Intern((Connection?.RemoteEndPoint as IPEndPoint)?.Address);
-            _toString = Address?.ToString() ?? "(error)";
-        }
-        catch (Exception ex)
-        {
-            TraceException(ex);
-            Address = IPAddress.None;
-            _toString = "(error)";
-        }
+        _toString = address?.ToString() ?? "(error)";
 
         _instances.Add(this);
-        _connecting.Add(this);
-        _handle = GCHandle.Alloc(this);
+        _connectingQueue.Enqueue(this);
 
         LogInfo($"Connected. [{_instances.Count} Online]");
-
-        try
-        {
-            _pollGroup.Add(connection, _handle);
-        }
-        catch (Exception ex)
-        {
-            TraceException(ex);
-            Disconnect("Unable to add socket to poll group");
-        }
     }
 
     // Sectors
@@ -188,16 +161,10 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
 
     public IPAddress Address { get; }
 
-    public DecodePacket PacketDecoder
+    public IClientEncryption Encryption
     {
-        get => _packetDecoder;
-        set => _packetDecoder = value;
-    }
-
-    public EncodePacket PacketEncoder
-    {
-        get => _packetEncoder;
-        set => _packetEncoder = value;
+        get => _encryption;
+        set => _encryption = value;
     }
 
     public int CurrentPacket { get; internal set; }
@@ -210,13 +177,27 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
 
     public bool Seeded { get; set; }
 
-    public Pipe RecvPipe { get; }
-
-    public Pipe SendPipe { get; }
-
     public bool Running => _running;
 
-    public Socket Connection { get; private set; }
+    /// <summary>
+    /// Gets whether the socket is connected.
+    /// </summary>
+    public bool IsConnected => _running && _socket != null;
+
+    /// <summary>
+    /// Gets the socket handle.
+    /// </summary>
+    public nint SocketHandle => _socket?.Handle ?? 0;
+
+    /// <summary>
+    /// Gets the local endpoint (address/port) the client connected to.
+    /// </summary>
+    public IPEndPoint LocalEndPoint => _socket != null ? SocketHelper.GetLocalEndPoint(_socket.Handle) : null;
+
+    /// <summary>
+    /// Gets the send buffer for this connection.
+    /// </summary>
+    internal IORingBuffer SendBuffer => _socket?.SendBuffer;
 
     public bool CompressionEnabled { get; set; }
 
@@ -235,15 +216,7 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
     public IAccount Account
     {
         get => _account;
-        set
-        {
-            if (_account != null)
-            {
-                _connecting.Remove(this);
-            }
-
-            _account = value;
-        }
+        set => _account = value;
     }
 
     public string Assistant { get; set; }
@@ -464,8 +437,14 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
                 return false;
             }
 #endif
-        buffer = SendPipe.Writer.AvailableToWrite();
-        return !(SendPipe.Writer.IsClosed || buffer.Length <= 0);
+        if (!_running || _socket == null)
+        {
+            buffer = Span<byte>.Empty;
+            return false;
+        }
+
+        buffer = _socket.SendBuffer.GetWriteSpan();
+        return buffer.Length > 0;
     }
 
     public void Send(ReadOnlySpan<byte> span)
@@ -483,21 +462,25 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
 
         try
         {
-            if (_packetEncoder != null)
+            // Apply encoding first (e.g., compression from UOContent)
+            if (CompressionEnabled)
             {
-                length = _packetEncoder(span, buffer);
+                length = NetworkCompression.Compress(span, buffer);
             }
             else
             {
                 span.CopyTo(buffer);
             }
 
+            // Then encrypt (if encryption is enabled)
+            _encryption?.ServerEncrypt(buffer[..length]);
+
             if (PacketLogging)
             {
                 LogPacket(span, false);
             }
 
-            SendPipe.Writer.Advance((uint)length);
+            _socket.SendBuffer.CommitWrite(length);
 
             if (!_flushQueued)
             {
@@ -554,26 +537,34 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
         }
     }
 
-    public void HandleReceive(bool throttled = false)
+    private void DecryptRecvBuffer(int bytesReceived)
     {
-        if (!_running)
+        if (_socket == null || _encryption == null)
         {
             return;
         }
 
-        if (!throttled)
+        // Get the portion of the buffer that was just written (the new data)
+        var readSpan = _socket.RecvBuffer.GetReadSpan();
+        var newDataStart = Math.Max(0, readSpan.Length - bytesReceived);
+
+        _encryption?.ClientDecrypt(readSpan.Slice(newDataStart, bytesReceived));
+    }
+
+    public void HandleReceive(bool throttled = false)
+    {
+        if (!_running || _socket == null)
         {
-            ReceiveData();
+            return;
         }
 
-        var reader = RecvPipe.Reader;
-
+        // Data already in recv buffer from recv completion - no need to call ReceiveData
         try
         {
             // Process as many packets as we can synchronously
             while (_running && _parserState != ParserState.Error && _protocolState != ProtocolState.Error)
             {
-                var buffer = reader.AvailableToRead();
+                var buffer = _socket.RecvBuffer.GetReadSpan();
                 var length = buffer.Length;
 
                 if (length <= 0)
@@ -632,13 +623,63 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
 
                         case ProtocolState.LoginServer_AwaitingLogin:
                             {
-                                if (packetId != 0x80)
+                                // Check for unencrypted login packet
+                                if (packetId == 0x80)
+                                {
+                                    // Unencrypted - check if allowed
+                                    if (EncryptionManager.Enabled && !EncryptionManager.Mode.HasFlag(EncryptionMode.Unencrypted))
+                                    {
+                                        LogInfo("Unencrypted client rejected by encryption policy.");
+                                        HandleError(packetId, packetLength);
+                                        return;
+                                    }
+
+                                    _parserState = ParserState.ProcessingPacket;
+                                    _parserState = HandlePacket(packetReader, packetId, out packetLength);
+                                    if (_parserState == ParserState.AwaitingNextPacket)
+                                    {
+                                        _protocolState = ProtocolState.LoginServer_AwaitingServerSelect;
+                                    }
+                                    break;
+                                }
+
+                                // First byte isn't 0x80 - might be encrypted
+                                if (!EncryptionManager.Enabled)
                                 {
                                     LogInfo("Possible encrypted client detected, disconnecting...");
                                     HandleError(packetId, packetLength);
                                     return;
                                 }
 
+                                // Need 62 bytes for login packet to attempt decryption
+                                if (length < 62)
+                                {
+                                    _parserState = ParserState.AwaitingPartialPacket;
+                                    break;
+                                }
+
+                                // Try to detect and decrypt encrypted login
+                                if (!this.DetectLoginEncryption(buffer[..62], out var loginEncryption))
+                                {
+                                    LogInfo("Encrypted client detection failed, disconnecting...");
+                                    HandleError(packetId, packetLength);
+                                    return;
+                                }
+
+                                // Decryption succeeded - set up encryption and process
+                                if (loginEncryption != null)
+                                {
+                                    _encryption = loginEncryption;
+
+                                    // Decrypt the buffer in place for processing
+                                    var mutableBuffer = _socket.RecvBuffer.GetReadSpan();
+                                    loginEncryption.ClientDecrypt(mutableBuffer[..62]);
+                                }
+
+                                // Now process as normal (first byte should now be 0x80)
+                                packetReader = new SpanReader(buffer);
+                                packetId = packetReader.ReadByte();
+
                                 _parserState = ParserState.ProcessingPacket;
                                 _parserState = HandlePacket(packetReader, packetId, out packetLength);
                                 if (_parserState == ParserState.AwaitingNextPacket)
@@ -680,17 +721,68 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
 
                         case ProtocolState.GameServer_AwaitingGameServerLogin:
                             {
+                                // Some clients send 0x80 on game server connection
                                 if (packetId == 0x80)
                                 {
                                     goto case ProtocolState.LoginServer_AwaitingLogin;
                                 }
 
-                                if (packetId != 0x91)
+                                // Check for unencrypted game login packet
+                                if (packetId == 0x91)
+                                {
+                                    // Unencrypted - check if allowed
+                                    if (EncryptionManager.Enabled && !EncryptionManager.Mode.HasFlag(EncryptionMode.Unencrypted))
+                                    {
+                                        LogInfo("Unencrypted game client rejected by encryption policy.");
+                                        HandleError(packetId, packetLength);
+                                        return;
+                                    }
+
+                                    _parserState = ParserState.ProcessingPacket;
+                                    _parserState = HandlePacket(packetReader, packetId, out packetLength);
+                                    if (_parserState == ParserState.AwaitingNextPacket)
+                                    {
+                                        _protocolState = ProtocolState.GameServer_LoggedIn;
+                                    }
+                                    break;
+                                }
+
+                                // First byte isn't 0x91 - might be encrypted
+                                if (!EncryptionManager.Enabled)
                                 {
                                     HandleError(packetId, packetLength);
                                     return;
                                 }
 
+                                // Need 65 bytes for game login packet to attempt decryption
+                                if (length < 65)
+                                {
+                                    _parserState = ParserState.AwaitingPartialPacket;
+                                    break;
+                                }
+
+                                // Try to detect and decrypt encrypted game login
+                                if (!this.DetectGameEncryption(buffer[..65], out var gameEncryption))
+                                {
+                                    LogInfo("Encrypted game client detection failed, disconnecting...");
+                                    HandleError(packetId, packetLength);
+                                    return;
+                                }
+
+                                // Decryption succeeded - set up encryption and process
+                                if (gameEncryption != null)
+                                {
+                                    _encryption = gameEncryption;
+
+                                    // Decrypt the buffer in place for processing
+                                    var mutableBuffer = _socket.RecvBuffer.GetReadSpan();
+                                    gameEncryption.ClientDecrypt(mutableBuffer[..65]);
+                                }
+
+                                // Now process as normal (first byte should now be 0x91)
+                                packetReader = new SpanReader(buffer);
+                                packetId = packetReader.ReadByte();
+
                                 _parserState = ParserState.ProcessingPacket;
                                 _parserState = HandlePacket(packetReader, packetId, out packetLength);
                                 if (_parserState == ParserState.AwaitingNextPacket)
@@ -711,7 +803,7 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
 
                 if (_parserState is ParserState.AwaitingNextPacket)
                 {
-                    reader.Advance((uint)packetLength);
+                    _socket.RecvBuffer.CommitRead(packetLength);
                 }
                 else if (_parserState is ParserState.Throttled)
                 {
@@ -844,225 +936,15 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
         return ParserState.AwaitingNextPacket;
     }
 
-    private bool Flush()
-    {
-        _flushQueued = false;
-
-        // We don't have a running check since we need to send the last bits of data even after a disconnect, but before a dispose.
-        if (Connection == null)
-        {
-            return true;
-        }
-
-        var reader = SendPipe.Reader;
-        var buffer = reader.AvailableToRead();
-
-        if (reader.IsClosed || buffer.Length == 0)
-        {
-            return true;
-        }
-
-        var bytesWritten = 0;
-
-        try
-        {
-            bytesWritten = Connection.Send(buffer, SocketFlags.None);
-        }
-        catch (SocketException ex)
-        {
-            if (ex.SocketErrorCode != SocketError.WouldBlock)
-            {
-                logger.Debug(ex, "Disconnected due to a socket exception");
-                Disconnect(string.Empty);
-                return true;
-            }
-        }
-        catch (Exception ex)
-        {
-            Disconnect($"Disconnected with error: {ex}");
-            TraceException(ex);
-            return true;
-        }
-
-        if (bytesWritten > 0)
-        {
-            NextActivityCheck = Core.TickCount + 90000;
-            reader.Advance((uint)bytesWritten);
-        }
-
-        return bytesWritten == buffer.Length;
-    }
-
-    private void DecodePacket(Span<byte> buffer, ref int length)
-    {
-        _packetDecoder?.Invoke(buffer, ref length);
-    }
-
-    private void ReceiveData()
-    {
-        var writer = RecvPipe.Writer;
-        var buffer = writer.AvailableToWrite();
-
-        if (writer.IsClosed || buffer.Length == 0)
-        {
-            return;
-        }
-
-        var bytesWritten = 0;
-
-        try
-        {
-            bytesWritten = Connection.Receive(buffer, SocketFlags.None);
-        }
-        catch (SocketException ex)
-        {
-            if (ex.ErrorCode is not 54 and not 89 and not 995)
-            {
-                logger.Debug(ex, "Disconnected due to a socket exception");
-            }
-
-            Disconnect(string.Empty);
-        }
-        catch (Exception ex)
-        {
-            Disconnect($"Disconnected with error: {ex}");
-            TraceException(ex);
-        }
-
-        if (bytesWritten <= 0)
-        {
-            Disconnect(string.Empty);
-            return;
-        }
-
-        DecodePacket(buffer, ref bytesWritten);
-
-        writer.Advance((uint)bytesWritten);
-        NextActivityCheck = Core.TickCount + 90000;
-    }
-
-    private static void DisconnectUnattachedSockets()
-    {
-        var now = Core.Now;
-
-        // Clear out any sockets that have been connecting for too long
-        while (_connecting.Count > 0)
-        {
-            var ns = _connecting.Min;
-            var socketTime = ns.ConnectedOn;
-
-            // If the socket has been connected for less than the limit, we can stop checking
-            if (now - socketTime < ConnectingSocketIdleLimit)
-            {
-                break;
-            }
-
-            // Socket must have finished the entire authentication process or be forcibly disconnected.
-            if (!ns.Running || !ns.SentFirstPacket || !ns.Seeded || ns.Account == null)
-            {
-                // Not sending a message because it will fill up the logs.
-                ns.Disconnect(null);
-            }
-
-            _connecting.Remove(ns);
-        }
-    }
-
-    public static void FlushAll()
-    {
-        while (_flushPending.Count != 0)
-        {
-            _flushPending.Dequeue()?.Flush();
-        }
-    }
-
-    public static void Slice()
-    {
-        DisconnectUnattachedSockets();
-
-        while (_throttled.Count > 0)
-        {
-            var ns = _throttled.Dequeue();
-            if (ns.Running)
-            {
-                ns.HandleReceive(true);
-            }
-        }
-
-        // This is enqueued by HandleReceive if already throttled and still throttled
-        while (_throttledPending.Count > 0)
-        {
-            _throttled.Enqueue(_throttledPending.Dequeue());
-        }
-
-        var count = _pollGroup.Poll(_polledStates);
-
-        if (count > 0)
-        {
-            for (var i = 0; i < count; i++)
-            {
-                (_polledStates[i].Target as NetState)?.HandleReceive();
-                _polledStates[i] = default;
-            }
-        }
-
-        while (_flushPending.TryDequeue(out var ns))
-        {
-            if (!ns.Flush())
-            {
-                // Incomplete data, so we need to requeue
-                _flushedPartials.Enqueue(ns);
-            }
-        }
-
-        var hasDisposes = false;
-        while (_disposed.TryDequeue(out var ns))
-        {
-            hasDisposes = true;
-            ns.Dispose();
-        }
-
-        // If they weren't disconnected, requeue them
-        while (_flushedPartials.TryDequeue(out var ns))
-        {
-            if (ns.Running)
-            {
-                _flushPending.Enqueue(ns);
-            }
-        }
-
-        if (hasDisposes)
-        {
-            _pollGroup.Poll(_polledStates.Length);
-        }
-    }
-
     public void CheckAlive(long curTicks)
     {
-        if (Connection != null && NextActivityCheck - curTicks < 0)
+        if (_socket != null && NextActivityCheck - curTicks < 0)
         {
             LogInfo("Disconnecting due to inactivity...");
             Disconnect("Disconnecting due to inactivity.");
         }
     }
 
-    public static void CheckAllAlive()
-    {
-        try
-        {
-            var curTicks = Core.TickCount;
-
-            foreach (var ns in Instances)
-            {
-                ns.CheckAlive(curTicks);
-            }
-        }
-        catch (Exception ex)
-        {
-            TraceException(ex);
-        }
-    }
-
     public void Trace(ReadOnlySpan<byte> buffer)
     {
         // We don't have data, so nothing to trace
@@ -1105,17 +987,24 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
         Console.WriteLine(ex);
     }
 
+    /// <summary>
+    /// Requests a graceful disconnect. The disconnect is queued and processed after the flush
+    /// queue in Slice(), ensuring Send() calls made in the same tick are processed first.
+    /// </summary>
     public void Disconnect(string reason)
     {
-        if (!_running)
+        if (!_running || _socket == null)
         {
             return;
         }
 
-        _running = false;
-
         _disconnectReason = reason;
-        _disposed.Enqueue(this);
+
+        if (!_disconnectQueued)
+        {
+            _disconnectQueued = true;
+            _pendingDisconnects.Enqueue(this);
+        }
     }
 
     public static void TraceDisconnect(string reason, string ip)
@@ -1148,16 +1037,18 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
     {
         _running = false;
         // It's possible we could queue for dispose multiple times
-        if (Connection == null)
+        if (_socket == null)
         {
             return;
         }
 
         TraceDisconnect(_disconnectReason, _toString);
 
+        // If still running, force immediate disconnect
         if (_running)
         {
-            throw new Exception("Disconnected a NetState that is still running.");
+            _running = false;
+            _socketManager?.DisconnectImmediate(_socket);
         }
 
         var m = Mobile;
@@ -1167,21 +1058,17 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
         }
 
         _instances.Remove(this);
-        _connecting.Remove(this);
 
-        try
+        // Clear the NetState slot
+        var slotId = _socket.Id;
+        if (slotId >= 0 && slotId < _netStates.Length && _netStates[slotId] == this)
         {
-            _pollGroup.Remove(Connection, _handle);
-        }
-        catch (Exception ex)
-        {
-            TraceException(ex);
+            _netStates[slotId] = null;
         }
 
-        Connection.Close();
-        _handle.Free();
-        RecvPipe.Dispose();
-        SendPipe.Dispose();
+        // Note: RingSocketManager handles cleanup of ring resources (unregister, close, buffer release)
+        // when it processes the disconnect event. We just clear our reference.
+        _socket = null;
 
         Mobile = null;
 
@@ -1192,46 +1079,9 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
         Account = null;
         ServerInfo = null;
         CityInfo = null;
-        Connection = null;
 
         var count = _instances.Count;
 
         LogInfo(a != null ? $"Disconnected. [{count} Online] [{a}]" : $"Disconnected. [{count} Online]");
     }
-
-    private class NetStateConnectingComparer : IComparer<NetState>
-    {
-        public static readonly IComparer<NetState> Instance = new NetStateConnectingComparer();
-
-        public int Compare(NetState x, NetState y)
-        {
-            if (x == null && y == null)
-            {
-                return 0;
-            }
-
-            if (x == null)
-            {
-                return -1;
-            }
-
-            if (y == null)
-            {
-                return 1;
-            }
-
-            if (ReferenceEquals(x, y))
-            {
-                return 0;
-            }
-
-            var connectedOn = x.ConnectedOn.CompareTo(y.ConnectedOn);
-            if (connectedOn != 0)
-            {
-                return connectedOn;
-            }
-
-            return x.CompareTo(y);
-        }
-    }
 }

Projects/Server/Network/Packets/OutgoingPackets.cs

@@ -7,7 +7,7 @@ public static class OutgoingPackets
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static bool CannotSendPackets(this NetState ns) =>
         // Do not check for NetState.Running. Packets are sent to a "disconnected" socket as part of the OnDisconnect events
-        // up until the Connection is nulled. Closing the connection is done synchronously, therefore packets will not be sent
+        // up until the socket is closed. Closing the connection is done synchronously, therefore packets will not be sent
         // once the Mobile.NetState is null.
-        ns?.Connection == null || ns.BlockAllPackets;
+        ns == null || ns.SocketHandle == 0 || ns.BlockAllPackets;
 }

Projects/Server/Network/PingServer.cs

@@ -61,7 +61,7 @@ public static class PingServer
 
             if (ipep.Address.Equals(IPAddress.Any) || ipep.Address.Equals(IPAddress.IPv6Any))
             {
-                listeningAddresses.UnionWith(TcpServer.GetListeningAddresses(ipep));
+                listeningAddresses.UnionWith(NetState.GetListeningAddresses(ipep));
             }
             else
             {

Projects/Server/Network/Pipe.cs

@@ -1,519 +0,0 @@
-/*************************************************************************
- * ModernUO                                                              *
- * Copyright 2019-2023 - ModernUO Development Team                       *
- * Email: hi@modernuo.com                                                *
- * File: Pipe.cs                                                         *
- *                                                                       *
- * This program is free software: you can redistribute it and/or modify  *
- * it under the terms of the GNU General Public License as published by  *
- * the Free Software Foundation, either version 3 of the License, or     *
- * (at your option) any later version.                                   *
- *                                                                       *
- * You should have received a copy of the GNU General Public License     *
- * along with this program.  If not, see <http://www.gnu.org/licenses/>. *
- *************************************************************************/
-
-using System;
-using System.IO;
-using System.Runtime.InteropServices;
-
-namespace Server.Network;
-
-public partial class Pipe : IDisposable
-{
-    public class PipeWriter
-    {
-        private readonly Pipe _pipe;
-
-        internal PipeWriter(Pipe pipe) => _pipe = pipe;
-
-        public unsafe Span<byte> AvailableToWrite()
-        {
-            var read = _pipe._readIdx;
-            var write = _pipe._writeIdx;
-
-            uint sz;
-            if (read <= write)
-            {
-                sz = _pipe.Size - write + read - 1;
-            }
-            else
-            {
-                sz = read - write - 1;
-            }
-
-            return new Span<byte>((void*)(_pipe._buffer + write), (int)sz);
-        }
-
-        public void Advance(uint count)
-        {
-            var read = _pipe._readIdx;
-            var write = _pipe._writeIdx;
-
-            if (count == 0)
-            {
-                return;
-            }
-
-            if (count > _pipe.Size - 1)
-            {
-                throw new EndOfPipeException("Unable to advance beyond the end of the pipe.");
-            }
-
-            if (read <= write)
-            {
-                if (count > read + _pipe.Size - write - 1)
-                {
-                    throw new EndOfPipeException("Unable to advance beyond the end of the pipe.");
-                }
-
-                var sz = Math.Min(count, _pipe.Size - write);
-
-                write += sz;
-                if (write > _pipe.Size - 1)
-                {
-                    write = 0;
-                }
-                count -= sz;
-
-                if (count > 0)
-                {
-                    if (count >= read)
-                    {
-                        throw new EndOfPipeException("Unable to advance beyond the end of the pipe.");
-                    }
-
-                    write = count;
-                }
-            }
-            else
-            {
-                if (count > read - write - 1)
-                {
-                    throw new EndOfPipeException("Unable to advance beyond the end of the pipe.");
-                }
-
-                write += count;
-            }
-
-            // It's never valid to advance the write pointer to become equal to
-            // the read pointer. Check that here.
-            if (write == read)
-            {
-                throw new EndOfPipeException("Unable to advance beyond the end of the pipe.");
-            }
-
-            _pipe._writeIdx = write;
-        }
-
-        public void Close() => _pipe._closed = true;
-
-        public bool IsClosed => _pipe._closed;
-    }
-
-    public class PipeReader
-    {
-        private readonly Pipe _pipe;
-
-        internal PipeReader(Pipe pipe) => _pipe = pipe;
-
-        public unsafe Span<byte> AvailableToRead()
-        {
-            var read = _pipe._readIdx;
-            var write = _pipe._writeIdx;
-
-            uint sz;
-            if (read <= write)
-            {
-                sz = write - read;
-            }
-            else
-            {
-                sz = _pipe.Size - read + write;
-            }
-
-            return new Span<byte>((void*)(_pipe._buffer + read), (int)sz);
-        }
-
-        public void Advance(uint count)
-        {
-            var read = _pipe._readIdx;
-            var write = _pipe._writeIdx;
-
-            if (read <= write)
-            {
-                if (count > write - read)
-                {
-                    throw new EndOfPipeException("Unable to advance beyond the end of the pipe.");
-                }
-
-                read += count;
-            }
-            else
-            {
-                var sz = Math.Min(count, _pipe.Size - read);
-
-                read += sz;
-                if (read > _pipe.Size - 1)
-                {
-                    read = 0;
-                }
-                count -= sz;
-
-                if (count > 0)
-                {
-                    if (count > write)
-                    {
-                        throw new EndOfPipeException("Unable to advance beyond the end of the pipe.");
-                    }
-
-                    read = count;
-                }
-            }
-
-            if (read == write)
-            {
-                // If the read pointer catches up to the write pointer, then the pipe is empty.
-                // As a performance optimization, set both to 0. This should improve the chances cache lines are hit.
-                _pipe._readIdx = 0;
-                _pipe._writeIdx = 0;
-            }
-            else
-            {
-                _pipe._readIdx = read;
-            }
-        }
-
-        public void Close() => _pipe._closed = true;
-
-        public bool IsClosed => _pipe._closed;
-    }
-
-    private IntPtr _handle; // Doubles as the file descriptor for linux/darwin
-    private IntPtr _buffer;
-    private readonly uint _bufferSize;
-    private uint _writeIdx;
-    private uint _readIdx;
-    private bool _closed;
-
-    public PipeWriter Writer { get; }
-    public PipeReader Reader { get; }
-
-    public uint Size => _bufferSize;
-
-    public bool Closed => _closed;
-
-    public Pipe(uint size)
-    {
-        var pageSize = (uint)Environment.SystemPageSize;
-
-        // Virtual allocation requires multiples of system page size
-        // So let's adjust the requested size rounded to the next available page size
-        var adjustedSize = (size + pageSize - 1) & ~(pageSize - 1);
-
-        if (Core.IsWindows)
-        {
-            // Reserve a region of virtual memory. We need twice the size so we can later mirror.
-            var region = NativeMethods_Windows.VirtualAlloc2(
-                IntPtr.Zero,
-                IntPtr.Zero,
-                adjustedSize * 2,
-                NativeMethods_Windows.MEM_RESERVE | NativeMethods_Windows.MEM_RESERVE_PLACEHOLDER,
-                NativeMethods_Windows.PAGE_NOACCESS,
-                IntPtr.Zero,
-                0
-            );
-
-            if (region == IntPtr.Zero)
-            {
-                throw new InvalidOperationException($"Allocating virtual memory failed. ({Marshal.GetLastPInvokeError()})");
-            }
-
-            // Releases half of the region so we can map the same memory region twice
-            var freed = NativeMethods_Windows.VirtualFree(
-                region,
-                adjustedSize,
-                NativeMethods_Windows.MEM_RELEASE | NativeMethods_Windows.MEM_PRESERVE_PLACEHOLDER
-            );
-
-            if (!freed)
-            {
-                throw new InvalidOperationException($"Creating virtual placeholder failed. ({Marshal.GetLastPInvokeError()})");
-            }
-
-            // Create a file descriptor
-            _handle = NativeMethods_Windows.CreateFileMappingW(
-                NativeMethods_Windows.InvalidHandleValue,
-                IntPtr.Zero,
-                NativeMethods_Windows.PAGE_READWRITE,
-                0,
-                adjustedSize,
-                null
-            );
-
-            if (_handle == IntPtr.Zero)
-            {
-                throw new InvalidOperationException($"Creating file mapping failed. ({Marshal.GetLastPInvokeError()})");
-            }
-
-            // Map the region to the first half of the virtual space
-            _buffer = NativeMethods_Windows.MapViewOfFile3(
-                _handle,
-                IntPtr.Zero,
-                region,
-                0,
-                adjustedSize,
-                NativeMethods_Windows.MEM_REPLACE_PLACEHOLDER,
-                NativeMethods_Windows.PAGE_READWRITE,
-                IntPtr.Zero,
-                0
-            );
-
-            if (_buffer == IntPtr.Zero)
-            {
-                throw new InvalidOperationException($"Mapping file view failed. ({Marshal.GetLastPInvokeError()})");
-            }
-
-            // Map the same region to the second half of the virtual space
-            var view2 = NativeMethods_Windows.MapViewOfFile3(
-                _handle,
-                IntPtr.Zero,
-                new IntPtr(_buffer + adjustedSize),
-                0,
-                adjustedSize,
-                NativeMethods_Windows.MEM_REPLACE_PLACEHOLDER,
-                NativeMethods_Windows.PAGE_READWRITE,
-                IntPtr.Zero,
-                0
-            );
-
-            if (view2 == IntPtr.Zero)
-            {
-                throw new InvalidOperationException($"Mapping file view mirror failed. ({Marshal.GetLastPInvokeError()})");
-            }
-        }
-        else if (Core.IsLinux || Core.IsDarwin)
-        {
-            var anon = Core.IsLinux ? NativeMethods_Linux.MAP_ANONYMOUS : NativeMethods_Linux.MAP_ANON;
-
-            int fd;
-
-            if (Core.IsLinux)
-            {
-                // Create a memory-backed file descriptor
-                fd = NativeMethods_Linux.memfd_create("mirrored_ring_buffer", 0);
-            }
-            else
-            {
-                var fdName = $"/muo/ring/{GetHashCode()}";
-                fd = NativeMethods_Linux.shm_open(fdName, NativeMethods_Linux.O_CREAT | NativeMethods_Linux.O_RDWR, 0600);
-
-                // Unlink immediately to emulate memfd_create() functionality
-                NativeMethods_Linux.shm_unlink(fdName);
-            }
-
-            if (fd == NativeMethods_Linux.InvalidPtrValue)
-            {
-                throw new InvalidOperationException($"Creating file descriptor failed. ({Marshal.GetLastPInvokeError()})");
-            }
-
-            // Set the size of the file descriptor
-            if (NativeMethods_Linux.ftruncate(fd, (int)adjustedSize) != 0)
-            {
-                throw new InvalidOperationException($"Setting file descriptor size failed. ({Marshal.GetLastPInvokeError()})");
-            }
-
-            // Get virtual address space, must be double the size so we can map twice
-            _buffer = NativeMethods_Linux.mmap(IntPtr.Zero, adjustedSize * 2,
-                NativeMethods_Linux.PROT_READ | NativeMethods_Linux.PROT_WRITE,
-                NativeMethods_Linux.MAP_PRIVATE | anon, NativeMethods_Linux.InvalidFileDescriptor, 0);
-
-            if (_buffer == NativeMethods_Linux.InvalidPtrValue)
-            {
-                throw new InsufficientMemoryException($"Allocating virtual memory failed. ({Marshal.GetLastPInvokeError()})");
-            }
-
-            // Map the file descriptor to the first half of the virtual space
-            var view1 = NativeMethods_Linux.mmap(_buffer, adjustedSize,
-                NativeMethods_Linux.PROT_READ | NativeMethods_Linux.PROT_WRITE,
-                NativeMethods_Linux.MAP_SHARED | NativeMethods_Linux.MAP_FIXED, fd, 0);
-
-            if (view1 == NativeMethods_Linux.InvalidPtrValue)
-            {
-                throw new InvalidOperationException($"Mapping memory failed. ({Marshal.GetLastPInvokeError()})");
-            }
-
-            // Map the file descriptor to the second half of the virtual space
-            var view2 = NativeMethods_Linux.mmap(new IntPtr(_buffer + adjustedSize), adjustedSize,
-                NativeMethods_Linux.PROT_READ | NativeMethods_Linux.PROT_WRITE,
-                NativeMethods_Linux.MAP_SHARED | NativeMethods_Linux.MAP_FIXED, fd, 0);
-
-            if (view2 == NativeMethods_Linux.InvalidPtrValue)
-            {
-                throw new InvalidOperationException($"Mapping mirrored memory failed. ({Marshal.GetLastPInvokeError()})");
-            }
-
-            _handle = fd;
-        }
-
-        _bufferSize = adjustedSize;
-        _writeIdx = 0;
-        _readIdx = 0;
-        _closed = false;
-
-        Writer = new PipeWriter(this);
-        Reader = new PipeReader(this);
-    }
-
-    private static partial class NativeMethods_Windows
-    {
-        private const string Kernel32 = "kernel32.dll";
-        private const string KernelBase = "kernelbase.dll";
-        public const IntPtr InvalidHandleValue = -1;
-
-        [LibraryImport(Kernel32, SetLastError = true, StringMarshalling = StringMarshalling.Utf16)]
-        public static partial IntPtr CreateFileMappingW(
-            IntPtr hFile, IntPtr lpFileMappingAttributes, uint flProtect, uint dwMaximumSizeHigh, uint dwMaximumSizeLow,
-            string lpName
-        );
-
-        [LibraryImport(KernelBase, SetLastError = true)]
-        public static partial IntPtr MapViewOfFile3(
-            IntPtr hFileMappingObject, IntPtr processHandle, IntPtr pvBaseAddress, ulong ullOffset, ulong ullSize,
-            uint allocFlags, uint dwDesiredAccess,
-            IntPtr hExtendedParameter, int parameterCount
-        );
-
-        [LibraryImport(Kernel32, SetLastError = true)]
-        [return: MarshalAs(UnmanagedType.Bool)]
-        public static partial bool UnmapViewOfFile(IntPtr lpBaseAddress);
-
-        [LibraryImport(Kernel32, SetLastError = true)]
-        [return: MarshalAs(UnmanagedType.Bool)]
-        public static partial bool CloseHandle(IntPtr hObject);
-
-        [LibraryImport(KernelBase, SetLastError = true)]
-        public static partial IntPtr VirtualAlloc2(
-            IntPtr process,
-            IntPtr address,
-            ulong size,
-            uint allocationType,
-            uint protect,
-            IntPtr extendedParameters,
-            uint parameterCount
-        );
-
-        [LibraryImport(Kernel32, SetLastError = true)]
-        [return: MarshalAs(UnmanagedType.Bool)]
-        public static partial bool VirtualFree(IntPtr lpAddress, uint dwSize, uint dwFreeType);
-
-        public const uint MEM_PRESERVE_PLACEHOLDER = 0x02;
-        public const uint MEM_RESERVE = 0x2000;
-        public const uint MEM_REPLACE_PLACEHOLDER = 0x4000;
-        public const uint MEM_RELEASE = 0x8000;
-        public const uint MEM_RESERVE_PLACEHOLDER = 0x40000;
-        public const uint PAGE_NOACCESS = 0x01;
-        public const uint PAGE_READWRITE = 0x04;
-    }
-
-    private static partial class NativeMethods_Linux
-    {
-        private const string LibC = "libc";
-        public const IntPtr InvalidPtrValue = -1;
-        public const int InvalidFileDescriptor = -1;
-
-        // For MacOS
-        [LibraryImport(LibC, SetLastError = true, StringMarshalling = StringMarshalling.Utf8)]
-        public static partial int shm_open(string name, int oflag, int mode);
-
-        [LibraryImport(LibC, SetLastError = true, StringMarshalling = StringMarshalling.Utf8)]
-        public static partial int shm_unlink(string name);
-
-        [LibraryImport(LibC, SetLastError = true, StringMarshalling = StringMarshalling.Utf8)]
-        public static partial int memfd_create(string name, uint flags);
-
-        [LibraryImport(LibC, SetLastError = true)]
-        public static partial int ftruncate(int fd, int length);
-
-        [LibraryImport(LibC, SetLastError = true)]
-        public static partial int close(int fd);
-
-        [LibraryImport(LibC, SetLastError = true)]
-        public static partial IntPtr mmap(IntPtr addr, ulong length, int prot, int flags, int fd, int offset);
-
-        [LibraryImport(LibC, SetLastError = true)]
-        public static partial int munmap(IntPtr addr, ulong length);
-
-        public const int PROT_READ = 0x1;
-        public const int PROT_WRITE = 0x2;
-        public const int MAP_PRIVATE = 0x02;
-        public const int MAP_SHARED = 0x01;
-        public const int MAP_FIXED = 0x10;
-        public const int MAP_ANONYMOUS = 0x20;
-
-        // Darwin
-        public const int O_RDWR = 0x2;
-        public const int O_CREAT = 0x200;
-        public const int MAP_ANON = 0x1000;
-    }
-
-    private void ReleaseUnmanagedResources()
-    {
-        if (_buffer == IntPtr.Zero)
-        {
-            return;
-        }
-
-        if (Core.IsWindows)
-        {
-            if (_handle != IntPtr.Zero)
-            {
-                NativeMethods_Windows.CloseHandle(_handle);
-                _handle = IntPtr.Zero;
-            }
-
-            if (_buffer != IntPtr.Zero)
-            {
-                NativeMethods_Windows.UnmapViewOfFile(_buffer);
-                NativeMethods_Windows.UnmapViewOfFile(new IntPtr(_buffer + _bufferSize));
-            }
-        }
-        else if (Core.IsLinux || Core.IsDarwin)
-        {
-            if (_handle != NativeMethods_Linux.InvalidFileDescriptor)
-            {
-#pragma warning disable CA2020
-                NativeMethods_Linux.close((int)_handle);
-#pragma warning restore CA2020
-
-                _handle = NativeMethods_Linux.InvalidFileDescriptor;
-            }
-
-            if (_buffer != IntPtr.Zero)
-            {
-                NativeMethods_Linux.munmap(_buffer, _bufferSize);
-                NativeMethods_Linux.munmap(new IntPtr(_buffer + _bufferSize), _bufferSize);
-            }
-        }
-
-        _buffer = IntPtr.Zero;
-    }
-
-    public void Dispose()
-    {
-        ReleaseUnmanagedResources();
-        GC.SuppressFinalize(this);
-    }
-
-    ~Pipe()
-    {
-        ReleaseUnmanagedResources();
-    }
-}
-
-public class EndOfPipeException : IOException
-{
-    public EndOfPipeException(string message) : base(message)
-    {
-    }
-}

Projects/Server/Network/SocketHelper.cs

@@ -0,0 +1,218 @@
+/*************************************************************************
+ * ModernUO                                                              *
+ * Copyright 2019-2025 - ModernUO Development Team                       *
+ * Email: hi@modernuo.com                                                *
+ * File: SocketHelper.cs                                                 *
+ *                                                                       *
+ * This program is free software: you can redistribute it and/or modify  *
+ * it under the terms of the GNU General Public License as published by  *
+ * the Free Software Foundation, either version 3 of the License, or     *
+ * (at your option) any later version.                                   *
+ *                                                                       *
+ * You should have received a copy of the GNU General Public License     *
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>. *
+ *************************************************************************/
+
+using System;
+using System.Net;
+using System.Net.Sockets;
+using System.Runtime.InteropServices;
+
+namespace Server.Network;
+
+/// <summary>
+/// Platform-specific socket utilities for working with raw socket handles.
+/// </summary>
+public static partial class SocketHelper
+{
+    /// <summary>
+    /// Gets the remote IP address from a socket handle.
+    /// </summary>
+    /// <param name="socket">The socket handle.</param>
+    /// <returns>The remote IP address, or null if unable to retrieve.</returns>
+    public static IPAddress GetRemoteAddress(nint socket)
+    {
+        if (socket is 0 or -1)
+        {
+            return null;
+        }
+
+        try
+        {
+            return RuntimeInformation.IsOSPlatform(OSPlatform.Windows)
+                ? GetRemoteAddressWindows(socket)
+                : GetRemoteAddressUnix(socket);
+        }
+        catch
+        {
+            return null;
+        }
+    }
+
+    private static unsafe IPAddress GetRemoteAddressWindows(nint socket)
+    {
+        Span<byte> buffer = stackalloc byte[128];
+        var len = buffer.Length;
+
+        fixed (byte* ptr = buffer)
+        {
+            if (getpeername(socket, ptr, ref len) != 0)
+            {
+                return null;
+            }
+        }
+
+        return ParseSockAddr(buffer[..len]);
+    }
+
+    private static unsafe IPAddress GetRemoteAddressUnix(nint socket)
+    {
+        Span<byte> buffer = stackalloc byte[128];
+        var len = (uint)buffer.Length;
+
+        fixed (byte* ptr = buffer)
+        {
+            if (getpeername_unix(socket, ptr, ref len) != 0)
+            {
+                return null;
+            }
+        }
+
+        return ParseSockAddr(buffer[..(int)len]);
+    }
+
+    /// <summary>
+    /// Gets the local endpoint from a socket handle.
+    /// </summary>
+    /// <param name="socket">The socket handle.</param>
+    /// <returns>The local endpoint, or null if unable to retrieve.</returns>
+    public static IPEndPoint GetLocalEndPoint(nint socket)
+    {
+        if (socket is 0 or -1)
+        {
+            return null;
+        }
+
+        try
+        {
+            return RuntimeInformation.IsOSPlatform(OSPlatform.Windows)
+                ? GetLocalEndPointWindows(socket)
+                : GetLocalEndPointUnix(socket);
+        }
+        catch
+        {
+            return null;
+        }
+    }
+
+    private static unsafe IPEndPoint GetLocalEndPointWindows(nint socket)
+    {
+        Span<byte> buffer = stackalloc byte[128];
+        var len = buffer.Length;
+
+        fixed (byte* ptr = buffer)
+        {
+            if (getsockname(socket, ptr, ref len) != 0)
+            {
+                return null;
+            }
+        }
+
+        return ParseSockAddrEndPoint(buffer[..len]);
+    }
+
+    private static unsafe IPEndPoint GetLocalEndPointUnix(nint socket)
+    {
+        Span<byte> buffer = stackalloc byte[128];
+        var len = (uint)buffer.Length;
+
+        fixed (byte* ptr = buffer)
+        {
+            if (getsockname_unix(socket, ptr, ref len) != 0)
+            {
+                return null;
+            }
+        }
+
+        return ParseSockAddrEndPoint(buffer[..(int)len]);
+    }
+
+    private static IPAddress ParseSockAddr(ReadOnlySpan<byte> buffer)
+    {
+        if (buffer.Length < 2)
+        {
+            return null;
+        }
+
+        // macOS/BSD: sockaddr has sin_len (1 byte) + sin_family (1 byte)
+        // Linux: sockaddr has sa_family (2 bytes)
+        var isBsd = RuntimeInformation.IsOSPlatform(OSPlatform.OSX) ||
+                    RuntimeInformation.IsOSPlatform(OSPlatform.FreeBSD);
+        var family = isBsd
+            ? (AddressFamily)buffer[1]  // BSD: family is second byte
+            : (AddressFamily)BitConverter.ToInt16(buffer);  // Linux: family is first 2 bytes
+
+        if (family == AddressFamily.InterNetwork && buffer.Length >= 8)
+        {
+            // IPv4: family (2) + port (2) + addr (4)
+            return new IPAddress(buffer.Slice(4, 4));
+        }
+
+        if (family == AddressFamily.InterNetworkV6 && buffer.Length >= 28)
+        {
+            // IPv6: family (2) + port (2) + flowinfo (4) + addr (16) + scope (4)
+            return new IPAddress(buffer.Slice(8, 16));
+        }
+
+        return null;
+    }
+
+    private static IPEndPoint ParseSockAddrEndPoint(ReadOnlySpan<byte> buffer)
+    {
+        if (buffer.Length < 4)
+        {
+            return null;
+        }
+
+        // macOS/BSD: sockaddr has sin_len (1 byte) + sin_family (1 byte)
+        // Linux: sockaddr has sa_family (2 bytes)
+        var isBsd = RuntimeInformation.IsOSPlatform(OSPlatform.OSX) ||
+                    RuntimeInformation.IsOSPlatform(OSPlatform.FreeBSD);
+        var family = isBsd
+            ? (AddressFamily)buffer[1]  // BSD: family is second byte
+            : (AddressFamily)BitConverter.ToInt16(buffer);  // Linux: family is first 2 bytes
+
+        // Port is in network byte order (big-endian), at offset 2 on both platforms
+        var port = (buffer[2] << 8) | buffer[3];
+
+        if (family == AddressFamily.InterNetwork && buffer.Length >= 8)
+        {
+            // IPv4: family (2) + port (2) + addr (4)
+            return new IPEndPoint(new IPAddress(buffer.Slice(4, 4)), port);
+        }
+
+        if (family == AddressFamily.InterNetworkV6 && buffer.Length >= 28)
+        {
+            // IPv6: family (2) + port (2) + flowinfo (4) + addr (16) + scope (4)
+            return new IPEndPoint(new IPAddress(buffer.Slice(8, 16)), port);
+        }
+
+        return null;
+    }
+
+    // Windows getpeername
+    [LibraryImport("ws2_32.dll", SetLastError = true)]
+    private static unsafe partial int getpeername(nint s, byte* name, ref int namelen);
+
+    // Unix/Linux getpeername
+    [LibraryImport("libc", EntryPoint = "getpeername", SetLastError = true)]
+    private static unsafe partial int getpeername_unix(nint sockfd, byte* addr, ref uint addrlen);
+
+    // Windows getsockname
+    [LibraryImport("ws2_32.dll", SetLastError = true)]
+    private static unsafe partial int getsockname(nint s, byte* name, ref int namelen);
+
+    // Unix/Linux getsockname
+    [LibraryImport("libc", EntryPoint = "getsockname", SetLastError = true)]
+    private static unsafe partial int getsockname_unix(nint sockfd, byte* addr, ref uint addrlen);
+}

Projects/Server/Network/TcpServer.cs

@@ -1,254 +0,0 @@
-/*************************************************************************
- * ModernUO                                                              *
- * Copyright 2019-2024 - ModernUO Development Team                       *
- * Email: hi@modernuo.com                                                *
- * File: TcpServer.cs                                                    *
- *                                                                       *
- * This program is free software: you can redistribute it and/or modify  *
- * it under the terms of the GNU General Public License as published by  *
- * the Free Software Foundation, either version 3 of the License, or     *
- * (at your option) any later version.                                   *
- *                                                                       *
- * You should have received a copy of the GNU General Public License     *
- * along with this program.  If not, see <http://www.gnu.org/licenses/>. *
- *************************************************************************/
-
-using System;
-using System.Buffers.Binary;
-using System.Collections.Generic;
-using System.Linq;
-using System.Net;
-using System.Net.NetworkInformation;
-using System.Net.Sockets;
-using System.Runtime.CompilerServices;
-using System.Threading;
-using System.Threading.Tasks;
-using Server.Logging;
-
-namespace Server.Network;
-
-public static class TcpServer
-{
-    private static readonly ILogger logger = LogFactory.GetLogger(typeof(TcpServer));
-
-    // AccountLoginReject BadComm
-    private static readonly byte[] _socketRejected = [0x82, 0xFF];
-
-    public static IPEndPoint[] ListeningAddresses { get; private set; }
-    public static Socket[] Listeners { get; private set; }
-
-    private static IPRateLimiter _ipRateLimiter;
-
-    public static void Start()
-    {
-        _ipRateLimiter = new IPRateLimiter(10, 10000, 1000, 2.0, 3_600_000, Core.ClosingTokenSource.Token);
-        HashSet<IPEndPoint> listeningAddresses = [];
-        List<Socket> listeners = [];
-        foreach (var ipep in ServerConfiguration.Listeners)
-        {
-            var listener = CreateListener(ipep);
-            if (listener == null)
-            {
-                continue;
-            }
-
-            if (ipep.Address.Equals(IPAddress.Any) || ipep.Address.Equals(IPAddress.IPv6Any))
-            {
-                listeningAddresses.UnionWith(GetListeningAddresses(ipep));
-            }
-            else
-            {
-                listeningAddresses.Add(ipep);
-            }
-
-            listeners.Add(listener);
-            BeginAcceptingSockets(listener);
-        }
-
-        foreach (var ipep in listeningAddresses)
-        {
-            logger.Information("Listening: {Address}", ipep);
-        }
-
-        ListeningAddresses = listeningAddresses.ToArray();
-        Listeners = listeners.ToArray();
-    }
-
-    public static void Shutdown()
-    {
-        foreach (var listener in Listeners)
-        {
-            listener.Close();
-        }
-    }
-
-    public static IEnumerable<IPEndPoint> GetListeningAddresses(IPEndPoint ipep) =>
-        NetworkInterface.GetAllNetworkInterfaces().SelectMany(adapter =>
-            adapter.GetIPProperties().UnicastAddresses
-                .Where(uip => ipep.AddressFamily == uip.Address.AddressFamily)
-                .Select(uip => new IPEndPoint(uip.Address, ipep.Port))
-        );
-
-    public static Socket CreateListener(IPEndPoint ipep)
-    {
-        var listener = new Socket(ipep.AddressFamily, SocketType.Stream, ProtocolType.Tcp)
-        {
-            LingerState = new LingerOption(false, 0),
-            ExclusiveAddressUse = true,
-            NoDelay = true,
-            Blocking = false,
-            SendBufferSize = 64 * 1024,
-            ReceiveBufferSize = 64 * 1024
-        };
-
-        try
-        {
-            listener.Bind(ipep);
-            listener.Listen(256);
-            return listener;
-        }
-        catch (SocketException se)
-        {
-            // WSAEADDRINUSE
-            if (se.ErrorCode == 10048)
-            {
-                logger.Warning("Listener: {Address} Exception: {Reason}", ipep, "Currently in use");
-            }
-            // WSAEADDRNOTAVAIL
-            else if (se.ErrorCode == 10049)
-            {
-                logger.Warning("Listener {Address} Exception: {Reason}", ipep, "Unavailable");
-            }
-            else
-            {
-                logger.Warning(se, "Listener {Address} Exception: {Reason}", ipep, se.Message);
-            }
-        }
-
-        return null;
-    }
-
-    private static async ValueTask BeginAcceptingSockets(Socket listener)
-    {
-        while (!Core.Closing)
-        {
-            try
-            {
-                var socket = await listener.AcceptAsync(Core.ClosingTokenSource.Token);
-                var remoteIP = ((IPEndPoint)socket.RemoteEndPoint)!.Address;
-
-                if (!_ipRateLimiter.Verify(remoteIP, out var totalAttempts))
-                {
-                    logger.Debug("{Address} Past IP limit threshold ({TotalAttempts})", remoteIP, totalAttempts);
-                }
-                else if (Firewall.IsBlocked(remoteIP))
-                {
-                    logger.Debug("{Address} Firewalled", remoteIP);
-                }
-                else
-                {
-                    _ = Task.Run(() => ProcessSocketConnection(socket), Core.ClosingTokenSource.Token);
-                }
-            }
-            catch
-            {
-                // ignored
-            }
-        }
-    }
-
-    [ThreadStatic]
-    private static byte[] _firstBytes;
-
-    private static async ValueTask ProcessSocketConnection(Socket socket)
-    {
-        _firstBytes ??= GC.AllocateUninitializedArray<byte>(128);
-
-        using var cts = CancellationTokenSource.CreateLinkedTokenSource(Core.ClosingTokenSource.Token);
-        cts.CancelAfter(TimeSpan.FromMilliseconds(500));
-
-        try
-        {
-            var bytesRead = await socket.ReceiveAsync(_firstBytes, SocketFlags.Peek, cts.Token);
-
-            var isValid =
-                // Sometimes when newer clients are connecting to the game server the first 4 bytes are sent separately
-                bytesRead == 4 ||
-
-                // Support Freeshard Protocol (UOGateway)
-                bytesRead == 8 &&
-                BinaryPrimitives.ReadUInt32BigEndian(_firstBytes.AsSpan(4)) is 0xF10004FF or 0xF10004FE ||
-
-                // Older clients only send the 4 byte seed first then 0x80
-                (UOClient.MinRequired == null || UOClient.MinRequired < ClientVersion.Version6050) &&
-                bytesRead >= 66 && _firstBytes[4] == 0x80 ||
-
-                // Newer clients
-                (UOClient.MaxRequired == null || UOClient.MaxRequired >= ClientVersion.Version6050) && (
-                    // Account Login - 0xEF + 0x80 (83 bytes)
-                    bytesRead >= 83 && _firstBytes[0] == 0xEF && _firstBytes[21] == 0x80 ||
-                    bytesRead == 21 && _firstBytes[0] == 0xEF ||
-                    // Game Login - 4 bytes + 0x91 (69 bytes)
-                    bytesRead >= 69 && _firstBytes[4] == 0x91
-                );
-
-            // TODO: Validate client version is v4 -> v7 for 0xEF packet
-            // TODO: Validate Account Login seed matches Game Login seed
-            // TODO: Validate AuthId for 0x91 packet
-            // TODO: Validate username is ascii and not empty
-            // TODO: Validate password is ascii and not empty
-            if (isValid)
-            {
-                var args = new SocketConnectEventArgs(socket);
-                EventSink.InvokeSocketConnect(args);
-
-                if (args.AllowConnection)
-                {
-                    Core.LoopContext.Post(() => _ = new NetState(socket), EventLoopContext.Priority.High);
-                    return;
-                }
-
-                logger.Debug("{Address} Rejected by socket handler", ((IPEndPoint)socket.RemoteEndPoint)!.Address);
-
-                cts.TryReset();
-                cts.CancelAfter(TimeSpan.FromMilliseconds(500));
-                await socket.SendAsync(_socketRejected, SocketFlags.None, cts.Token);
-                CloseSocket(socket);
-            }
-            else
-            {
-                ForceCloseSocket(socket);
-            }
-        }
-        catch
-        {
-            ForceCloseSocket(socket);
-        }
-    }
-
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    private static void CloseSocket(Socket socket)
-    {
-        try
-        {
-            socket.Shutdown(SocketShutdown.Both);
-        }
-        finally
-        {
-            socket.Close();
-        }
-    }
-
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    private static void ForceCloseSocket(Socket socket)
-    {
-        try
-        {
-            socket.Disconnect(false);
-        }
-        finally
-        {
-            socket.Close(0);
-        }
-    }
-}

Projects/Server/Server.csproj

@@ -21,12 +21,12 @@
         <Delete Files="..\..\Distribution\$(AssemblyName).runtimeconfig.json" ContinueOnError="true" />
         <Delete Files="..\..\Distribution\ModernUO.Serialization.Annotations.dll" ContinueOnError="true" />
         <Delete Files="..\..\Distribution\CommunityToolkit.HighPerformance.dll" ContinueOnError="true" />
-        <Delete Files="..\..\Distribution\PollGroup.dll" ContinueOnError="true" />
+        <Delete Files="..\..\Distribution\IORingGroup.dll" ContinueOnError="true" />
+        <Delete Files="..\..\Distribution\ioring.dll" ContinueOnError="true" />
         <Delete Files="..\..\Distribution\ref\$(AssemblyName).dll" ContinueOnError="true" />
         <Delete Files="..\..\Distribution\Serilog.dll" ContinueOnError="true" />
         <Delete Files="..\..\Distribution\Serilog.Sinks.Async.dll" ContinueOnError="true" />
         <Delete Files="..\..\Distribution\Serilog.Sinks.Console.dll" ContinueOnError="true" />
-        <Delete Files="..\..\Distribution\wepoll.dll" ContinueOnError="true" />
         <Delete Files="..\..\Distribution\LibDeflate.Bindings.dll" ContinueOnError="true" />
         <Delete Files="..\..\Distribution\libdeflate.dll" ContinueOnError="true" />
         <Delete Files="..\..\Distribution\libdeflate.dylib" ContinueOnError="true" />
@@ -34,9 +34,9 @@
     </Target>
     <ItemGroup>
         <ProjectReference Include="..\Logger\Logger.csproj" />
+        <PackageReference Include="IORingGroup" Version="1.0.0" />
         <PackageReference Include="CommunityToolkit.HighPerformance" Version="8.4.0" />
         <PackageReference Include="LibDeflate.Bindings" Version="1.0.2.120" />
-        <PackageReference Include="PollGroup" Version="1.7.1" />
         <PackageReference Include="System.IO.Hashing" Version="10.0.2" />
 
         <PackageReference Include="ModernUO.Serialization.Annotations" Version="2.14.0" />

Projects/Server/Utilities/BitMask256.cs

@@ -66,10 +66,22 @@ public struct BitMask256
 
         switch (segment)
         {
-            case 0: Bits0 |= mask; break;
-            case 1: Bits1 |= mask; break;
-            case 2: Bits2 |= mask; break;
-            case 3: Bits3 |= mask; break;
+            case 0:
+                {
+                    Bits0 |= mask; break;
+                }
+            case 1:
+                {
+                    Bits1 |= mask; break;
+                }
+            case 2:
+                {
+                    Bits2 |= mask; break;
+                }
+            case 3:
+                {
+                    Bits3 |= mask; break;
+                }
         }
     }
 
@@ -90,10 +102,22 @@ public struct BitMask256
 
         switch (segment)
         {
-            case 0: Bits0 &= ~mask; break;
-            case 1: Bits1 &= ~mask; break;
-            case 2: Bits2 &= ~mask; break;
-            case 3: Bits3 &= ~mask; break;
+            case 0:
+                {
+                    Bits0 &= ~mask; break;
+                }
+            case 1:
+                {
+                    Bits1 &= ~mask; break;
+                }
+            case 2:
+                {
+                    Bits2 &= ~mask; break;
+                }
+            case 3:
+                {
+                    Bits3 &= ~mask; break;
+                }
         }
     }
 

Projects/UOContent.Tests/Fixtures/UOContentFixture.cs

@@ -26,6 +26,9 @@ public class UOContentFixture : ICollectionFixture<UOContentFixture>, IDisposabl
         // Load Skills
         SkillsInfo.Configure();
 
+        // Configure networking (initializes RingSocketManager for tests)
+        Server.Network.NetState.Configure();
+
         // Configure / Initialize
         TestMapDefinitions.ConfigureTestMapDefinitions();
 

Projects/UOContent.Tests/Tests/Engines/Chat/ChatPacketTests.cs

@@ -5,7 +5,7 @@ using Xunit;
 
 namespace UOContent.Tests;
 
-[Collection("Sequential Server Tests")]
+[Collection("Sequential UOContent Tests")]
 public class ChatPacketTests
 {
     [Theory]
@@ -18,7 +18,7 @@ public class ChatPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendChatMessage(lang, number, param1, param2);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/UOContent.Tests/Tests/Engines/Help/TestHelpTopicPacket.cs

@@ -19,7 +19,7 @@ public class TestHelpTopicPacket
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendDisplayHelpTopic(topic, display);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/UOContent.Tests/Tests/Engines/ML Quests/MLQuestPacketTests.cs

@@ -73,7 +73,7 @@ public class MLQuestPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendRaceChanger(female, race);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -85,7 +85,7 @@ public class MLQuestPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendCloseRaceChanger();
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/UOContent.Tests/Tests/Engines/Party/PartyPacketTests.cs

@@ -19,7 +19,7 @@ public class PartyPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendPartyRemoveMember(m);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -40,7 +40,7 @@ public class PartyPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendPartyRemoveMember(member.Serial, p);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -61,7 +61,7 @@ public class PartyPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendPartyMemberList(p);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -78,7 +78,7 @@ public class PartyPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendPartyTextMessage(serial, text, toAll);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -92,7 +92,7 @@ public class PartyPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendPartyInvitation(m);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/UOContent.Tests/Tests/Engines/Veteran Rewards/Character Statue Maker/CharacterStatuePacketTests.cs

@@ -7,7 +7,7 @@ using Xunit;
 
 namespace UOContent.Tests;
 
-[Collection("Sequential Server Tests")]
+[Collection("Sequential UOContent Tests")]
 public class CharacterStatuePacketTests
 {
     [Theory]
@@ -19,7 +19,7 @@ public class CharacterStatuePacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendStatueAnimation((Serial)s, status, anim, frame);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/UOContent.Tests/Tests/Items/Books/BookPacketTests.cs

@@ -50,7 +50,7 @@ public class BookPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendBookCover(m, book);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -87,7 +87,7 @@ public class BookPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendBookContent(book);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/UOContent.Tests/Tests/Items/Bulletin Boards/BulletinBoardPacketTests.cs

@@ -23,7 +23,7 @@ public class BulletinBoardPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendBBDisplayBoard(bb);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -50,7 +50,7 @@ public class BulletinBoardPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendBBMessage(bb, msg, content);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/UOContent.Tests/Tests/Items/Games/Mahjong/MahjongPacketTests.cs

@@ -19,7 +19,7 @@ public class MahjongPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendMahjongJoinGame(game);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -39,7 +39,7 @@ public class MahjongPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendMahjongPlayersInfo(game, m);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -57,7 +57,7 @@ public class MahjongPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendMahjongGeneralInfo(game);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -77,7 +77,7 @@ public class MahjongPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendMahjongTilesInfo(game, m);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -97,7 +97,7 @@ public class MahjongPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendMahjongTileInfo(game.Tiles[0], m);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -111,7 +111,7 @@ public class MahjongPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendMahjongRelieve(game);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/UOContent.Tests/Tests/Items/Maps/TestMapItemPackets.cs

@@ -24,7 +24,7 @@ public class TestMapItemPackets
             (Packet)new MapDetailsNew(mapItem) : new MapDetails(mapItem)).Compile();
         ns.SendMapDetails(mapItem);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -42,7 +42,7 @@ public class TestMapItemPackets
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendMapCommand(mapItem, command, x, y, number > 0);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/UOContent.Tests/Tests/Items/Misc/Corpses/CorpsePacketTests.cs

@@ -26,7 +26,7 @@ public class CorpsePacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendCorpseEquip(m, c);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -50,7 +50,7 @@ public class CorpsePacketTests
 
         ns.SendCorpseContent(m, c);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/UOContent.Tests/Tests/Items/Weapons/Abilities/WeaponAbilityPacketTests.cs

@@ -20,7 +20,7 @@ public class WeaponAbilityPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendToggleSpecialAbility(abilityId, active);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -32,7 +32,7 @@ public class WeaponAbilityPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendClearWeaponAbility();
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/UOContent.Tests/Tests/Multis/Boats/BoatPacketTests.cs

@@ -59,7 +59,7 @@ public class BoatPacketTests
 
         ns.SendMoveBoatHS(boat, list, d, speed, xOffset, yOffset);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -103,7 +103,7 @@ public class BoatPacketTests
 
         ns.SendDisplayBoatHS(beholder, boat);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 

Projects/UOContent.Tests/Tests/Multis/Houses/HousePacketTests.cs

@@ -20,7 +20,7 @@ public class HousePacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendBeginHouseCustomization((Serial)serial);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -33,7 +33,7 @@ public class HousePacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendEndHouseCustomization((Serial)serial);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -47,7 +47,7 @@ public class HousePacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendDesignStateGeneral((Serial)serial, revision);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 

Projects/UOContent.Tests/Tests/Network/Packets/ArrowPacketTests.cs

@@ -14,7 +14,7 @@ public class ArrowPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendCancelArrow(0, 0, Serial.Zero);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -29,7 +29,7 @@ public class ArrowPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendSetArrow(x, y, Serial.Zero);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -47,7 +47,7 @@ public class ArrowPacketTests
         ns.ProtocolChanges = ProtocolChanges.HighSeas;
         ns.SendCancelArrow(x, y, serial);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -65,7 +65,7 @@ public class ArrowPacketTests
         ns.ProtocolChanges = ProtocolChanges.HighSeas;
         ns.SendSetArrow(x, y, serial);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/UOContent.Tests/Tests/Network/Packets/BuffIconPacketTests.cs

@@ -24,7 +24,7 @@ public class BuffIconPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendAddBuffPacket((Serial)mob, iconID, titleCliloc, secondaryCliloc, args, (int)timeSpan.TotalMilliseconds);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -38,7 +38,7 @@ public class BuffIconPacketTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendRemoveBuffPacket(m, buffIcon);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/UOContent.Tests/Tests/Skills/SkillPacketsTests.cs

@@ -27,7 +27,7 @@ public class SkillPacketsTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendSkillChange(skill);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 
@@ -45,7 +45,7 @@ public class SkillPacketsTests
         using var ns = PacketTestUtilities.CreateTestNetState();
         ns.SendSkillsUpdate(skills);
 
-        var result = ns.SendPipe.Reader.AvailableToRead();
+        var result = ns.SendBuffer.GetReadSpan();
         AssertThat.Equal(result, expected);
     }
 }

Projects/UOContent/Misc/ServerList.cs

@@ -79,14 +79,14 @@ namespace Server.Misc
             {
                 var ns = e.State;
 
-                var ipep = (IPEndPoint)ns.Connection?.LocalEndPoint;
-                if (ipep == null)
+                var localEndPoint = ns.LocalEndPoint;
+                if (localEndPoint == null)
                 {
                     return;
                 }
 
-                var localAddress = ipep.Address;
-                var localPort = ipep.Port;
+                var localAddress = localEndPoint.Address;
+                var localPort = localEndPoint.Port;
 
                 if (_useServerListingAddressConfig)
                 {
@@ -94,9 +94,8 @@ namespace Server.Misc
                 }
                 else if (localAddress.IsPrivateNetwork())
                 {
-                    ipep = (IPEndPoint)ns.Connection.RemoteEndPoint;
-
-                    if (ipep == null || !ipep.Address.IsPrivateNetwork() && _publicAddress != null)
+                    // Check if client is from a public network
+                    if (!ns.Address.IsPrivateNetwork() && _publicAddress != null)
                     {
                         localAddress = _publicAddress;
                     }

Projects/UOContent/Network/Packets/IncomingAccountPackets.cs

@@ -384,7 +384,6 @@ public static class IncomingAccountPackets
 
             // Comment out these lines to turn off huffman compression
             state.CompressionEnabled = true;
-            state.PacketEncoder ??= NetworkCompression.Compress;
 
             state.SendSupportedFeature();
             state.SendCharacterList();

Projects/UOContent/Special Systems/Engines/PreventInaccess.cs

@@ -69,7 +69,7 @@ namespace Server.Misc
             }
         }
 
-        private static bool HasDisconnected(Mobile m) => m.NetState?.Connection == null;
+        private static bool HasDisconnected(Mobile m) => m.NetState is not { IsConnected: true };
 
         private static LocationInfo GetRandomDestination() => m_Destinations.RandomElement();
 

README.md

@@ -71,13 +71,13 @@ ModernUO [![Discord](https://img.shields.io/discord/751317910504603701?logo=disc
 dnf upgrade --refresh -y
 # CentOS does not come with EPEL enabled
 dnf install -y epel-release epel-next-release
-dnf install -y findutils libicu libdeflate-devel zstd libargon2-devel
+dnf install -y findutils libicu libdeflate-devel zstd libargon2-devel liburing-devel
 ```
 
 ### Ubuntu, Debian, etc
 ```shell
 apt-get update -y
-apt-get install -y libicu-dev libdeflate-dev zstd libargon2-dev
+apt-get install -y libicu-dev libdeflate-dev zstd libargon2-dev liburing-dev
 ```
 
 ## OSX Requirements

version.json

@@ -1,4 +1,4 @@
 {
   "$schema": "https://raw.githubusercontent.com/dotnet/Nerdbank.GitVersioning/master/src/NerdBank.GitVersioning/version.schema.json",
-  "version": "0.15.4"
+  "version": "0.15.5"
 }