Bypass the proxy using TcpClient

问题:

I'm trying to write a local proxy application. I know how proxy applications work in theory. I've done everything related to handle incoming connections. But the problem is how should I send request which client requested to specified Url. When I try to create a connection with TcpClient to specified Url and port, it throws following exception :

No such host is known

Edit : I think I should bypass the proxy something like FireFox is doing even system proxy set.

Any idea will be helpful. Thanks in advance.

回答1:

These links might be of help:

• http://www.replicator.org/journal/201011170043-net-connecting-a-tcpclient-through-an-http-proxy-with-authentication

• http://alandean.blogspot.co.uk/2010/06/routing-tcpclient-http-requests-through.html

回答2:

Based on colinsmith provided links, I've done to bypass proxy using TcpClient. Here is how I did that :

    public static TcpClient CreateTcpClient(string url)
    {
        var webRequest = WebRequest.Create(url);
        webRequest.Proxy = null;

        var webResponse = webRequest.GetResponse();
        var resposeStream = webResponse.GetResponseStream();

        const BindingFlags flags = BindingFlags.NonPublic | BindingFlags.Instance;

        var rsType = resposeStream.GetType();
        var connectionProperty = rsType.GetProperty("Connection", flags);

        var connection = connectionProperty.GetValue(resposeStream, null);
        var connectionType = connection.GetType();
        var networkStreamProperty = connectionType.GetProperty("NetworkStream", flags);

        var networkStream = networkStreamProperty.GetValue(connection, null);
        var nsType = networkStream.GetType();
        var socketProperty = nsType.GetProperty("Socket", flags);
        var socket = (Socket)socketProperty.GetValue(networkStream, null);

        return new TcpClient { Client = socket };
    }

Hope this help for others.