Ignore errors when try to close already closed WebSockets

Projects/Server/Network/NetState/NetState.cs

@@ -19,6 +19,7 @@ using Server.HuePickers;
 using Server.Items;
 using Server.Logging;
 using Server.Menus;
+using Server.Network.Sockets;
 using System;
 using System.Buffers;
 using System.Collections.Concurrent;
@@ -29,6 +30,9 @@ using System.Net.Sockets;
 using System.Network;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
+using System.Text.RegularExpressions;
+using System.Text;
+using System.Security.Cryptography;
 
 namespace Server.Network;
 
@@ -41,7 +45,7 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
 {
     private static readonly ILogger logger = LogFactory.GetLogger(typeof(NetState));
 
-    private static readonly TimeSpan ConnectingSocketIdleLimit = TimeSpan.FromMilliseconds(5000); // 5 seconds
+    private static readonly TimeSpan ConnectingSocketIdleLimit = TimeSpan.FromMilliseconds(50000); // 5 seconds
     private const int RecvPipeSize = 1024 * 64;
     private const int SendPipeSize = 1024 * 256;
     private const int HuePickerCap = 512;
@@ -121,7 +125,7 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
 
     public NetState(Socket connection)
     {
-        Connection = connection;
+        Connection = new TcpSocket(connection);
         Seeded = false;
         HuePickers = [];
         Menus = [];
@@ -147,7 +151,7 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
 
         try
         {
-            _pollGroup.Add(connection, _handle);
+            _pollGroup.Add(Connection.Socket, _handle);
         }
         catch (Exception ex)
         {
@@ -216,7 +220,7 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
 
     public bool Running => _running;
 
-    public Socket Connection { get; private set; }
+    public ISocket Connection { get; private set; }
 
     public bool CompressionEnabled { get; set; }
 
@@ -577,6 +581,11 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
                                         _protocolState = ProtocolState.LoginServer_AwaitingLogin;
                                     }
                                 }
+                                else if (length > 3 && packetId == 0x47)
+                                {
+                                    _parserState = ParserState.ProcessingPacket;
+                                    _parserState = HandleWebSocket(buffer) ? ParserState.AwaitingNextPacket : ParserState.Error;
+                                }
                                 else if (length >= 4)
                                 {
                                     int newSeed = (packetId << 24) | (packetReader.ReadByte() << 16) | (packetReader.ReadByte() << 8) | packetReader.ReadByte();
@@ -651,7 +660,12 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
 
                         case ProtocolState.GameServer_AwaitingGameServerLogin:
                             {
-                                if (packetId != 0x91 && packetId != 0x80)
+                                if (length > 3 && packetId == 0x47)
+                                {
+                                    _parserState = ParserState.ProcessingPacket;
+                                    _parserState = HandleWebSocket(buffer) ? ParserState.AwaitingNextPacket : ParserState.Error;
+                                }
+                                else if (packetId != 0x91 && packetId != 0x80)
                                 {
                                     HandleError(packetId, packetLength);
                                     return;
@@ -832,7 +846,7 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
 
         try
         {
-            bytesWritten = Connection.Send(buffer, SocketFlags.None);
+            bytesWritten = Connection.Send(buffer);
         }
         catch (SocketException ex)
         {
@@ -875,10 +889,11 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
         }
 
         var bytesWritten = 0;
+        var forceClose = false;
 
         try
         {
-            bytesWritten = Connection.Receive(buffer, SocketFlags.None);
+            bytesWritten = Connection.Receive(buffer, out forceClose);
         }
         catch (SocketException ex)
         {
@@ -895,15 +910,18 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
             TraceException(ex);
         }
 
-        if (bytesWritten <= 0)
+        if (bytesWritten < 0 || forceClose)
         {
             Disconnect(string.Empty);
             return;
         }
 
-        DecodePacket(buffer, ref bytesWritten);
-
-        writer.Advance((uint)bytesWritten);
+        if (bytesWritten > 0)
+        {
+            DecodePacket(buffer, ref bytesWritten);
+            writer.Advance((uint)bytesWritten);
+        }
+        
         NextActivityCheck = Core.TickCount + 90000;
     }
 
@@ -1090,7 +1108,6 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
         }
 
         _running = false;
-
         _disconnectReason = reason;
         _disposed.Enqueue(this);
     }
@@ -1145,7 +1162,7 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
 
         try
         {
-            _pollGroup.Remove(Connection, _handle);
+            _pollGroup.Remove(Connection.Socket, _handle);
         }
         catch (Exception ex)
         {
@@ -1173,6 +1190,42 @@ public partial class NetState : IComparable<NetState>, IValueLinkListNode<NetSta
         LogInfo(a != null ? $"Disconnected. [{count} Online] [{a}]" : $"Disconnected. [{count} Online]");
     }
 
+    private bool HandleWebSocket(Span<byte> buffer)
+    {
+        try
+        {
+            string s = Encoding.UTF8.GetString(buffer);
+
+            if (!s.StartsWith("GET", StringComparison.InvariantCultureIgnoreCase))
+            {
+                Disconnect("BOH");
+                return false;
+            }
+
+            string swk = Regex.Match(s, "Sec-WebSocket-Key: (.*)").Groups[1].Value.Trim();
+            string swka = swk + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
+            byte[] swkaSha1 = SHA1.HashData(Encoding.UTF8.GetBytes(swka));
+            string swkaSha1Base64 = Convert.ToBase64String(swkaSha1);
+
+            byte[] response = Encoding.UTF8.GetBytes(
+                "HTTP/1.1 101 Switching Protocols\r\n" +
+                "Connection: Upgrade\r\n" +
+                "Upgrade: websocket\r\n" +
+                "Sec-WebSocket-Accept: " + swkaSha1Base64 + "\r\n\r\n");
+
+            var old = Connection;
+            Connection = new WebSocket(old.Socket);
+            old.Send(response);
+        }
+        catch
+        {
+            Disconnect("BOH2");
+            return false;
+        }
+
+        return true;
+    }
+
     private class NetStateConnectingComparer : IComparer<NetState>
     {
         public static readonly IComparer<NetState> Instance = new NetStateConnectingComparer();

Projects/Server/Network/Sockets/ISocket.cs

@@ -0,0 +1,18 @@
+using System;
+using System.Net;
+using System.Net.Sockets;
+
+namespace Server.Network.Sockets
+{
+    public interface ISocket
+    {
+        public Socket Socket { get; }
+        public bool Connected { get; }
+        public IPEndPoint? LocalEndPoint { get; }
+        public IPEndPoint? RemoteEndPoint { get; }
+
+        public int Send(ReadOnlySpan<byte> buffer);
+        public int Receive(Span<byte> buffer, out bool forceClose);
+        public void Close();
+    }
+}

Projects/Server/Network/Sockets/TcpSocket.cs

@@ -0,0 +1,31 @@
+using System;
+using System.Net;
+using System.Net.Sockets;
+
+namespace Server.Network.Sockets
+{
+    public sealed class TcpSocket : ISocket
+    {
+        public Socket Socket { get; }
+        public bool Connected => Socket.Connected;
+        public IPEndPoint? LocalEndPoint => Socket.LocalEndPoint as IPEndPoint;
+        public IPEndPoint? RemoteEndPoint => Socket.RemoteEndPoint as IPEndPoint;
+
+        public TcpSocket(Socket socket)
+        {
+            Socket = socket;
+        }
+
+        public int Send(ReadOnlySpan<byte> buffer) => Socket.Send(buffer, SocketFlags.None);
+        
+        public int Receive(Span<byte> buffer, out bool forceClose)
+        {
+            int bytesRead = Socket.Receive(buffer, SocketFlags.None);
+            forceClose = bytesRead == 0;
+
+            return bytesRead;
+        }
+
+        public void Close() => Socket.Close();
+    }
+}

Projects/Server/Network/Sockets/WebSocket.cs

@@ -0,0 +1,374 @@
+using System;
+using System.Buffers.Binary;
+using System.Diagnostics.CodeAnalysis;
+using System.Net;
+using System.Net.Sockets;
+using System.Runtime.CompilerServices;
+
+namespace Server.Network.Sockets
+{
+    public sealed class WebSocket : ISocket
+    {
+        private const int MinHeaderSize = 6; // 2 byte header + 4 byte mask
+        private const int MaxheaderSize = 14; // 2 byte header + 8 byte long length + 4 byte mask
+
+        private WriteStatus status;
+        private Mask mask;
+        private int headerLength;
+        private int remainingPayloadLength;
+        private int payloadMaskIndex;
+
+        public Socket Socket { get; }
+        public bool Connected => Socket.Connected;
+        public IPEndPoint LocalEndPoint => Socket.LocalEndPoint as IPEndPoint;
+        public IPEndPoint RemoteEndPoint => Socket.RemoteEndPoint as IPEndPoint;
+
+        public WebSocket(Socket socket)
+        {
+            Socket = socket;
+        }
+
+        public int Receive(Span<byte> buffer, out bool forceClose)
+        {
+            forceClose = false;
+            int available = Socket.Available;
+
+            if (available < MinHeaderSize)
+            {
+                if (available == 0)
+                {
+                    forceClose = true;
+                }
+
+                return 0;
+            }
+
+            Span<byte> header = stackalloc byte[MaxheaderSize];
+            int bytesWritten = 0;
+
+            while (available >= MinHeaderSize)
+            {
+                int iterationHeaderLength = Math.Min(available, MaxheaderSize);
+                Span<byte> iterationHeader = header[..iterationHeaderLength];
+
+                int bytesRead = Socket.Receive(iterationHeader, SocketFlags.Peek);
+                if (iterationHeaderLength != bytesRead)
+                {
+                    throw new Exception("WebSocket header length mismatch");
+                }
+
+                int iterationBytesWritten = 0;
+                OpCode opCode = (OpCode)(header[0] & 0b0000_1111);
+
+                bool completed = opCode switch
+                {
+                    OpCode.BinaryFrame => HandleDataFrame(header, available, buffer, out iterationBytesWritten),
+                    OpCode.ContinueFrame => HandleDataFrame(header, available, buffer, out iterationBytesWritten),
+                    OpCode.Ping => HandlePing(header, available),
+                    OpCode.Pong => HandlePong(header, available),
+                    OpCode.Close => HandleClose(header, available, out forceClose),
+                    _ => throw new NotSupportedException($"WebSocket OpCode {opCode} not supported"),
+                };
+
+                bytesWritten += iterationBytesWritten;
+
+                if (!completed)
+                {
+                    break;
+                }
+
+                available -= headerLength + iterationBytesWritten;
+                buffer = buffer[iterationBytesWritten..];
+                status = WriteStatus.WaitingForHeader;
+                payloadMaskIndex = 0;
+            }
+
+            return bytesWritten;
+        }
+
+        private bool HandlePing(Span<byte> header, int available)
+        {
+            // packets from client contains always a mask even for Control OpCodes
+            int totalLength = (byte)(header[1] & 0b0111_1111) + MinHeaderSize;
+            if (totalLength > available)
+            {
+                return false;
+            }
+
+            Span<byte> payload = stackalloc byte[totalLength];
+
+            int bytesRead = Socket.Receive(payload);
+            if (bytesRead != totalLength)
+            {
+                throw new Exception("WebSocket ping length mismatch");
+            }
+
+            const byte header1 = 0b1000_0000 | (byte)OpCode.Pong;
+
+            Socket.Send([header1, 0, .. payload[MinHeaderSize..]]);
+
+            return true;
+        }
+
+        private bool HandleClose(Span<byte> header, int available, out bool forceClose)
+        {
+            forceClose = true;
+
+            // packets from client contains always a mask even for Control OpCodes
+            int totalLength = (byte)(header[1] & 0b0111_1111) + MinHeaderSize;
+            if (totalLength > available)
+            {
+                return false;
+            }
+
+            Span<byte> payload = stackalloc byte[totalLength];
+
+            int bytesRead = Socket.Receive(payload);
+            if (bytesRead != totalLength)
+            {
+                throw new Exception("WebSocket close length mismatch");
+            }
+
+            const byte header1 = 0b1000_0000 | (byte)OpCode.Close;
+
+            Socket.Send([header1, 0, .. payload[MinHeaderSize..]]);
+
+            return true;
+        }
+
+        private bool HandlePong(Span<byte> header, int available)
+        {
+            // packets from client contains always a mask even for Control OpCodes
+            int totalLength = (byte)(header[1] & 0b0111_1111) + MinHeaderSize;
+            if (totalLength > available)
+            {
+                return false;
+            }
+
+            Span<byte> payload = stackalloc byte[totalLength];
+
+            int bytesRead = Socket.Receive(payload);
+            if (bytesRead != totalLength)
+            {
+                throw new Exception("WebSocket pong length mismatch");
+            }
+
+            return true;
+        }
+
+        private bool HandleDataFrame(Span<byte> header, int available, Span<byte> buffer, out int bytesWritten)
+        {
+            bytesWritten = 0;
+
+            if (status == WriteStatus.WaitingForHeader)
+            {
+                if (!ReadDataHeader(header))
+                {
+                    return false;
+                }
+            }
+
+            if (status == WriteStatus.WaitingForMask)
+            {
+                if (!ReadMask(header))
+                {
+                    return false;
+                }
+            }
+
+            if (status == WriteStatus.WritingPayload)
+            {
+                return WritePayload(buffer, available, out bytesWritten);
+            }
+
+            return false;
+        }
+
+        private bool ReadDataHeader(Span<byte> header)
+        {
+            bool masked = (header[1] & 0b1000_0000) != 0;
+            int length = (byte)(header[1] & 0b0111_1111);
+
+            if (!masked)
+            {
+                throw new NotSupportedException("WebSocket packet must be masked");
+            }
+
+            switch (length)
+            {
+                case <= 125:
+                    {
+                        headerLength = MinHeaderSize;
+                        break;
+                    }
+                case 126:
+                    {
+                        const int lengthSize = 2;
+
+                        if (header.Length < lengthSize + 2)
+                        {
+                            return false;
+                        }
+
+                        length = BinaryPrimitives.ReadUInt16BigEndian(header[2..4]);
+                        headerLength = lengthSize + MinHeaderSize;
+                        break;
+                    }
+                default:
+                    {
+                        const int lengthSize = 8;
+
+                        if (header.Length < lengthSize + 2)
+                        {
+                            return false;
+                        }
+
+                        length = (int)BinaryPrimitives.ReadUInt64BigEndian(header[2..10]);
+                        headerLength = lengthSize + MinHeaderSize;
+                        break;
+                    }
+            }
+
+            status = WriteStatus.WaitingForMask;
+            remainingPayloadLength = length;
+
+            return true;
+        }
+
+        private bool ReadMask(Span<byte> header)
+        {
+            if (header.Length < headerLength)
+            {
+                return false;
+            }
+
+            mask = new(header[(headerLength - 4)..]);
+            status = WriteStatus.WritingPayload;
+
+            int bytesRead = Socket.Receive(header[..headerLength]); // advance socket buffer to payload
+            if (bytesRead != headerLength)
+            {
+                throw new Exception("WebSocket header length mismatch");
+            }
+
+            return true;
+        }
+
+        private bool WritePayload(Span<byte> buffer, int available, out int bytesWritten)
+        {
+            int length = Math.Min(remainingPayloadLength, Math.Min(buffer.Length, available - headerLength));
+            if (length == 0)
+            {
+                bytesWritten = 0;
+                return false;
+            }
+
+            buffer = buffer[..length];
+
+            int bytesRead = Socket.Receive(buffer);
+            if (bytesRead != length)
+            {
+                throw new Exception("WebSocket payload length mismatch");
+            }
+
+            ApplyMask(buffer);
+
+            remainingPayloadLength -= bytesRead;
+            bytesWritten = bytesRead;
+
+            return remainingPayloadLength == 0;
+        }
+
+        private void ApplyMask(Span<byte> buffer)
+        {
+            for (int i = 0; i < buffer.Length; i++)
+            {
+                buffer[i] = (byte)(buffer[i] ^ mask[payloadMaskIndex++]);
+
+                if (payloadMaskIndex == 4)
+                {
+                    payloadMaskIndex = 0;
+                }
+            }
+        }
+
+        public int Send(ReadOnlySpan<byte> buffer)
+        {
+            const byte header1 = 0b1000_0000 | (byte)OpCode.BinaryFrame;
+
+            switch (buffer.Length)
+            {
+                case <= 125:
+                    {
+                        Socket.Send([header1, (byte)buffer.Length, .. buffer]);
+
+                        break;
+                    }
+                case < ushort.MaxValue:
+                    {
+                        ushort length = (ushort)buffer.Length;
+
+                        Socket.Send([header1, 126, (byte)(length >> 8), (byte)length, .. buffer]);
+
+                        break;
+                    }
+                default:
+                    {
+                        int length = buffer.Length;
+
+                        Socket.Send([header1, 127, 0, 0, 0, 0, (byte)(length >> 24), (byte)(length >> 16),
+                            (byte)(length >> 8), (byte)length, .. buffer]);
+
+                        break;
+                    }
+            }
+
+            return buffer.Length;
+        }
+
+        public void Close()
+        {
+            try
+            {
+                const byte header1 = 0b1000_0000 | (byte)OpCode.Close;
+                Socket.Send([header1, 0]);
+                Socket.Close();
+            }
+            catch
+            {
+                /* ignore already closed sockets */
+            }
+        }
+
+        private enum OpCode : byte
+        {
+            ContinueFrame = 0,
+            TextFrame = 1,
+            BinaryFrame = 2,
+            Close = 8,
+            Ping = 9,
+            Pong = 10,
+        }
+
+        [InlineArray(Size)]
+        private struct Mask
+        {
+            public const int Size = 4;
+
+            [SuppressMessage("CodeQuality", "IDE0051:Remove unused private members", Justification = "Inline array")]
+            private byte element0;
+
+            public Mask(Span<byte> mask)
+            {
+                mask[..4].CopyTo(this);
+            }
+        }
+
+        private enum WriteStatus
+        {
+            WaitingForHeader,
+            WaitingForMask,
+            WritingPayload,
+        }
+    }
+}

Projects/UOContent/Misc/ServerList.cs

@@ -70,7 +70,7 @@ namespace Server.Misc
             {
                 var ns = e.State;
 
-                var ipep = (IPEndPoint)ns.Connection?.LocalEndPoint;
+                var ipep = ns.Connection?.LocalEndPoint;
                 if (ipep == null)
                 {
                     return;