我使用System.Net和System.Net.Sockets的同步方法和类在C＃中编写了一个简单的代理服务器。除了一个小故障外，大部分事情都已完成。
当我从代理客户端（例如www.google.com）浏览网址时，它打开正常。当我进行关键字搜索时也很顺利。但是，当我点击搜索结果时，客户端再次在屏幕上看到google.com主页！但是，客户端浏览器URL栏仍显示单击的搜索结果URL。 也许这是因为谷歌结果页面没有提供到结果网址的直接链接，而是链接回谷歌本身，我认为我的代码中的中继逻辑无法处理。你能帮帮我吗？我的代码如下： （ThreadHandleClient（）方法是处理所有客户端请求并中继请求和响应的重要方法）
public void Start(IPAddress ip, int port)
{
try
{
TcpListener listener = new TcpListener(ip, port);
listener.Start(100);
while (!stopFlag)
{
Socket client = listener.AcceptSocket();
IPEndPoint rep = (IPEndPoint)client.RemoteEndPoint;
Thread th = new Thread(ThreadHandleClient);
th.Start(client);
}
listener.Stop();
}
catch (Exception ex)
{
Debug.Print("START: " + ex.Message);
}
}
public void Stop()
{
stopFlag = true;
}
public void ThreadHandleClient(object o)
{
try
{
Socket client = (Socket)o;
Debug.Print("lingerstate=" + client.LingerState.Enabled.ToString() + " timeout=" + client.LingerState.LingerTime.ToString());
NetworkStream ns = new NetworkStream(client);
//RECEIVE CLIENT DATA
byte[] buffer = new byte[2048];
int rec = 0, sent = 0, transferred = 0, rport = 0;
string data = "";
do
{
rec = ns.Read(buffer, 0, buffer.Length);
data += Encoding.ASCII.GetString(buffer, 0, rec);
} while (rec == buffer.Length);
//PARSE DESTINATION AND SEND REQUEST
string line = data.Replace("\r\n", "\n").Split(new string[] { "\n" }, StringSplitOptions.None)[0];
Uri uri = new Uri(line.Split(new string[] { " " }, StringSplitOptions.None)[1]);
Debug.Print("CLIENT REQUEST RECEIVED: " + uri.OriginalString);
if (uri.Scheme == "https")
{
rport = 443;
Debug.Print("HTTPS - 443");
//rq = HttpVersion + " 200 Connection established\r\nProxy-Agent: Prahlad`s Proxy Server\r\n\r\n";
//ClientSocket.BeginSend(Encoding.ASCII.GetBytes(rq), 0, rq.Length, SocketFlags.None, new AsyncCallback(this.OnOkSent), ClientSocket);
}
else
{
rport = 80;
Debug.Print("HTTP - 443");
}
IPHostEntry rh = Dns.GetHostEntry(uri.Host);
Socket webserver = new Socket(rh.AddressList[0].AddressFamily, SocketType.Stream, ProtocolType.IP);
webserver.Connect(new IPEndPoint(rh.AddressList[0], rport));
byte[] databytes = Encoding.ASCII.GetBytes(data);
webserver.Send(databytes, databytes.Length, SocketFlags.None);
Debug.Print("SENT TO SERVER. WILL NOW RELAY: " + data);
//START RELAY
buffer = new byte[2048];
bool firstTime = true;
rec = 0;
data = "";
do
{
transferred = 0;
do
{
if (webserver.Poll((firstTime ? 9000 : 2000) * 1000, SelectMode.SelectRead))
{
rec = webserver.Receive(buffer, buffer.Length, SocketFlags.None);
Debug.Print("RECEIVED FROM WEBSERVER[" + rec.ToString() + "]: " + Encoding.ASCII.GetString(buffer, 0, rec));
firstTime = false;
sent = client.Send(buffer, rec, SocketFlags.None);
Debug.Print("SENT TO CLIENT[" + sent.ToString() + "]: " + Encoding.ASCII.GetString(buffer, 0, rec));
transferred += rec;
}
else
{
Debug.Print("No data polled from webserver");
}
} while (rec == buffer.Length);
Debug.Print("loop-1 finished");
//if (transferred == 0)
// break;
//transferred = 0;
rec = 0;
do
{
if (client.Poll(1000 * 1000, SelectMode.SelectRead))
{
rec = client.Receive(buffer, buffer.Length, SocketFlags.None);
Debug.Print("RECEIVED FROM CLIENT: " + Encoding.ASCII.GetString(buffer, 0, rec));
sent = webserver.Send(buffer, rec, SocketFlags.None);
Debug.Print("SENT TO WEBSERVER[" + sent.ToString() + "]: " + Encoding.ASCII.GetString(buffer, 0, rec));
transferred += rec;
}
else
{
Debug.Print("No data polled from client");
}
} while (rec == buffer.Length);
Debug.Print("loop-2 finished");
} while (transferred > 0);
Debug.Print("LOOP ENDS. EXITING THREAD");
client.Close();
webserver.Close();
}
catch (Exception ex)
{
Debug.Print("Error occured: " + ex.Message);
}
finally {
Debug.Print("Client thread closed");
}
}
答案 0 :(得分：0)
经过一些试验和错误，我找到了解决方案，因此我回答了我自己的问题。我的中继逻辑的问题在于它曾用于中继两种方式，即来自webserver-＆gt;客户端和客户端＆gt; webserver。 我意识到转发第二部分可能会导致重定向出现问题，因为在重定向中，标题的url部分（“GET http://debian.org HTTP / 1.1”）会突然改变，因此它会与网络不同 - 服务器被中继!!例如，谷歌重定向指向debian.org，而代理仍然会转发来自google.com而非debian.org的流量。 为了避免这种情况，我删除了第二个中继部分（即客户端 - >网络服务器）。如果客户端发送新请求，最好在单独的线程中处理，以便将其定向到正确的URL主机。所以，我所要做的就是在我的继电器逻辑中注释出第二个内部循环：
//rec = 0;
//do
//{
// if (client.Poll(3000 * 1000, SelectMode.SelectRead))
// {
// rec = client.Receive(buffer, buffer.Length, SocketFlags.None);
// Debug.Print("RECEIVED FROM CLIENT: " + Encoding.ASCII.GetString(buffer, 0, rec));
// sent = webserver.Send(buffer, rec, SocketFlags.None);
// Debug.Print("SENT TO WEBSERVER[" + sent.ToString() + "]: " + Encoding.ASCII.GetString(buffer, 0, rec));
// transferred += rec;
// }
// else
// {
// Debug.Print("No data polled from client");
// }
//} while (rec == buffer.Length);
//Debug.Print("loop-2 finished");