Writing .NET proxy/tunnel engine for the HTTP

In my home network I have 2 computers: one of them is connected to the internet via dial-up connection. My pc has no modem, that is why to access the Internet I have to work on the other PC. I know that there is a bunch of gateway/proxy software that has the required functionality for tunneling http requests, but they aren’t open source and cannot be extended.

My goal is write extensible proxy engine, with default http tunneling implementation. And in the future other protocols may be added to it.

So, for now I’m studying RFC 2617 (Hypertext Transfer Protocol)…