TransformiceHandler.cs

using Transformice.Game;
using Transformice.Utils;

using System;
using System.Text;

using DotNetty.Buffers;
using DotNetty.Transport.Channels;

/**
 * Transformice sucks.
 *
 * @author Macaco <shcnedi@gmail.com>
 */

namespace Transformice.Network
{
    class NetworkHandler : ChannelHandlerAdapter
    {
        private Client _client;
        private byte[] _lastPacket;

        public override void ChannelRead(IChannelHandlerContext context, object message)
        {
            IByteBuffer buffer = message as IByteBuffer;
            if (buffer.ReadableBytes < 2) return;

            byte[] buff = new byte[buffer.ReadableBytes];
            buffer.ReadBytes(buff);

            string content = Encoding.ASCII.GetString(buff);
            if (content.StartsWith("<policy-file-request/>"))
            {
                byte[] policy = Encoding.Default.GetBytes("<cross-domain-policy><allow-access-from domain=\"*\" to-ports=\"*\" /></cross-domain-policy>");
                context.WriteAndFlushAsync(Unpooled.CopiedBuffer(policy));
            }

            if (_lastPacket != null) _lastPacket = null;

            var packet = new DataInputStream(new ByteArrayInputStream(buff));
            ParsePacket(packet, buff);
        }

        public void ParsePacket(DataInputStream packet, byte[] buff)
        {
            sbyte sizeBytes = packet.ReadByte();
            int length = sizeBytes == 1 ? packet.ReadUnsignedByte() : sizeBytes == 2 ? packet.ReadUnsignedShort() : sizeBytes == 3 ? ((packet.ReadUnsignedByte() & 0xFF) << 16) | ((packet.ReadUnsignedByte() & 0xFF) << 8) | (packet.ReadUnsignedByte() & 0xFF) : 0;

            if (length == 0) return;

            sbyte packetId = packet.ReadByte();
            if (packet.Available() == length)
            {
                if (packet.Available() == length)
                {
                    byte[] strBuff = new byte[packet.Available()];
                    packet.ReadFully(strBuff);

                }
            }
            else if (packet.Available() < length)
            {
                _lastPacket = buff;
            }
            else if (packet.Available() < length)
            {
                byte[] realPacket = new byte[length];
                packet.Read(realPacket, 0, length);

                if (length >= 2) _client.ParsePacket(new DataInputStream(new ByteArrayInputStream(realPacket)), realPacket, packetId);

                if (packet.Available() >= 2)
                {
                    byte[] rest = new byte[packet.Available()];
                    packet.ReadFully(rest);
                    ParsePacket(new DataInputStream(new ByteArrayInputStream(rest)), rest);
                }
            }
        }
    }
}