public Boolean Capture()
{
try
{
_socket.SetSocketOption(SocketOptionLevel.IP, SocketOptionName.HeaderIncluded, 1);
var inBytes = new Byte[] { 1, 0, 0, 0 };
var outBytes = new Byte[] { 0, 0, 0, 0 };
_socket.IOControl(IOControlCode.ReceiveAll, inBytes, outBytes);
if (0 != outBytes[0] + outBytes[1] + outBytes[2] + outBytes[3])
{
return(false);
}
}
catch (SocketException)
{
return(false);
}
while (_socket != null)
{
var buffer = new Byte[1500];
var count = _socket.Receive(buffer, SocketFlags.None);
var pk = new Packet(buffer, 0, count);
OnReceive?.Invoke(buffer, count);
if (OnTcpReceive != null)
{
var ip = new IPPacket(pk);
if (ip.Protocol == ProtocolType.Tcp)
{
var tcp = new TcpPacket(ip);
OnTcpReceive(tcp);
}
}
}
return(true);
}
public TcpPacket(IPPacket packet)
{
if (packet == null)
{
throw new ArgumentNullException(nameof(packet));
}
if (packet.Protocol != ProtocolType.Tcp)
{
throw new NotSupportedException();
}
IPPacket = packet;
var pk = packet.Data;
var data = pk.ReadBytes(0, 20);
SrcPort = (UInt16)((data[0] << 8) + data[1]);
DestPort = (UInt16)((data[2] << 8) + data[3]);
SequenceNo = ((UInt32)data[7] << 24) + ((UInt32)data[6] << 16) + ((UInt32)data[5] << 8) + data[4];
NextSeqNo = ((UInt32)data[11] << 24) + ((UInt32)data[10] << 16) + ((UInt32)data[9] << 8) + data[8];
HeadLength = (Byte)(((data[12] & 0xF0) >> 4) * 4);
// 6bit保留位
Flag = (Byte)(data[13] & 0x3F);
WindowSize = (UInt16)((data[14] << 8) + data[15]);
CheckSum = (UInt16)((data[16] << 8) + data[17]);
UrgPtr = (UInt16)((data[18] << 8) + data[19]);
// 可选项
if (HeadLength > 20)
{
Option = pk.ReadBytes(20, HeadLength - 20);
}
Data = pk.Sub(HeadLength);
}