private void OnReceive(IAsyncResult ar)
{
var received = _socket.EndReceive(ar);
var buffer = new ArraySegment<byte>(ar.AsyncState as byte[], 0, 32*1024);
var ipHeader = new IPHeader(buffer);
var packet = ParseData(ipHeader);
ProcessPacket(ipHeader.ProtocolType, packet);
var header = new byte[32 * 1024];
_socket.BeginReceive(header, 0, 32 * 1024, SocketFlags.None, OnReceive, header);
}
private void OnReceive(IAsyncResult ar)
{
var received = _socket.EndReceive(ar);
var buffer = new ArraySegment <byte>(ar.AsyncState as byte[], 0, 32 * 1024);
var ipHeader = new IPHeader(buffer);
var packet = ParseData(ipHeader);
ProcessPacket(ipHeader.ProtocolType, packet);
var header = new byte[32 * 1024];
_socket.BeginReceive(header, 0, 32 * 1024, SocketFlags.None, OnReceive, header);
}
private object ParseData(IPHeader ipHeader)
{
switch (ipHeader.ProtocolType)
{
case ProtocolType.Tcp:
return new TcpHeader(ipHeader);
case ProtocolType.Udp:
return new UdpHeader(ipHeader);
case ProtocolType.Unknown:
return null;
}
throw new NotSupportedException();
}
private object ParseData(IPHeader ipHeader)
{
switch (ipHeader.ProtocolType)
{
case ProtocolType.Tcp:
return(new TcpHeader(ipHeader));
case ProtocolType.Udp:
return(new UdpHeader(ipHeader));
case ProtocolType.Unknown:
return(null);
}
throw new NotSupportedException();
}
public UdpHeader(IPHeader ipHeader)
{
IpHeader = ipHeader;
var buffer = IpHeader.Data;
using(var memoryStream = new MemoryStream(buffer.Array, buffer.Offset, buffer.Count))
{
using (var binaryReader = new BinaryReader(memoryStream))
{
SourcePort = (ushort) IPAddress.NetworkToHostOrder(binaryReader.ReadInt16());
DestinationPort = (ushort) IPAddress.NetworkToHostOrder(binaryReader.ReadInt16());
Length = (ushort) IPAddress.NetworkToHostOrder(binaryReader.ReadInt16());
Checksum = IPAddress.NetworkToHostOrder(binaryReader.ReadInt16());
}
}
Data = new ArraySegment<byte>(buffer.Array, buffer.Offset + 8, buffer.Count - 8);
}
public UdpHeader(IPHeader ipHeader)
{
IpHeader = ipHeader;
var buffer = IpHeader.Data;
using (var memoryStream = new MemoryStream(buffer.Array, buffer.Offset, buffer.Count))
{
using (var binaryReader = new BinaryReader(memoryStream))
{
SourcePort = (ushort)IPAddress.NetworkToHostOrder(binaryReader.ReadInt16());
DestinationPort = (ushort)IPAddress.NetworkToHostOrder(binaryReader.ReadInt16());
Length = (ushort)IPAddress.NetworkToHostOrder(binaryReader.ReadInt16());
Checksum = IPAddress.NetworkToHostOrder(binaryReader.ReadInt16());
}
}
Data = new ArraySegment <byte>(buffer.Array, buffer.Offset + 8, buffer.Count - 8);
}
public TcpHeader(IPHeader ipHeader)
{
IpHeader = ipHeader;
var buffer = IpHeader.Data;
using (var memoryStream = new MemoryStream(buffer.Array, buffer.Offset, buffer.Count))
{
using (var binaryReader = new BinaryReader(memoryStream))
{
SourcePort = (ushort) IPAddress.NetworkToHostOrder(binaryReader.ReadInt16());
DestinationPort = (ushort) IPAddress.NetworkToHostOrder(binaryReader.ReadInt16());
SequenceNumber = (uint) IPAddress.NetworkToHostOrder(binaryReader.ReadInt32());
_uiAcknowledgementNumber = (uint) IPAddress.NetworkToHostOrder(binaryReader.ReadInt32());
_usDataOffsetAndFlags = (ushort) IPAddress.NetworkToHostOrder(binaryReader.ReadInt16());
WindowSize = (ushort) IPAddress.NetworkToHostOrder(binaryReader.ReadInt16());
Checksum = (short) IPAddress.NetworkToHostOrder(binaryReader.ReadInt16());
_usUrgentPointer = (ushort) IPAddress.NetworkToHostOrder(binaryReader.ReadInt16());
HeaderLength = (byte) (_usDataOffsetAndFlags >> 12);
HeaderLength *= 4;
MessageLength = buffer.Count - HeaderLength;
}
}
Data = new ArraySegment<byte>(buffer.Array, buffer.Offset + HeaderLength, MessageLength);
}
public TcpHeader(IPHeader ipHeader)
{
IpHeader = ipHeader;
var buffer = IpHeader.Data;
using (var memoryStream = new MemoryStream(buffer.Array, buffer.Offset, buffer.Count))
{
using (var binaryReader = new BinaryReader(memoryStream))
{
SourcePort = (ushort)IPAddress.NetworkToHostOrder(binaryReader.ReadInt16());
DestinationPort = (ushort)IPAddress.NetworkToHostOrder(binaryReader.ReadInt16());
SequenceNumber = (uint)IPAddress.NetworkToHostOrder(binaryReader.ReadInt32());
_uiAcknowledgementNumber = (uint)IPAddress.NetworkToHostOrder(binaryReader.ReadInt32());
_usDataOffsetAndFlags = (ushort)IPAddress.NetworkToHostOrder(binaryReader.ReadInt16());
WindowSize = (ushort)IPAddress.NetworkToHostOrder(binaryReader.ReadInt16());
Checksum = (short)IPAddress.NetworkToHostOrder(binaryReader.ReadInt16());
_usUrgentPointer = (ushort)IPAddress.NetworkToHostOrder(binaryReader.ReadInt16());
HeaderLength = (byte)(_usDataOffsetAndFlags >> 12);
HeaderLength *= 4;
MessageLength = buffer.Count - HeaderLength;
}
}
Data = new ArraySegment <byte>(buffer.Array, buffer.Offset + HeaderLength, MessageLength);
}
