.net and Socket Programming

Question

I have problems about writing a system in c# language that will, listen the port 10 on my computer for incoming data and transfer every data to IIS(running on port 80) on another computer and gets the responses from IIS then sends all responses back to client. In summary it is a bridge program. Anyone has an idea to build such a system? Thank you!

Administrator · Answer

Conceptually this is easy to do. Create a listening socket on TCP port 10. You could use either the Socket or the TCP Listener class. e.g. Socket MySocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); MySocket.Bind(new IPEndPoint((IPAddress)ipAddress, 10)); MySocket.Listen(CONNECTION_LIMIT); MyConnectedSocket = AdminSocket.Accept(); while(true) { byte[] RecvBuf = new byte[4096]; int BytesRead = MyConnectedSocket.Receive(RecvBuf, 0, RecvBuf.Length, SocketFlags.None); } Once you have the data in the buffer you would need to send it to a seperate socket which you have connected to the web server. This is also straight forward, there are lots of samples showing how to create and use sockets. Where the problems come in is HTTP1.1 web servers shutting down your socket. You need to send and receive on the web server socket so if the web server shuts it down you need to re-create it at the same time making sure that the socket listening on port 10 doesn't try and write to it if you are in the middle of re-creating it. It gets a fairly involved. Aaron