c# 实现端口转发可以用来实现远程桌面连接内网主机

gYP.Start（）方法调用后填写一台公网主机ip和端口（11111）然后公网主机用lcx转发11111到22222端口，远程桌面在公网主机连自己（127.0.0.1:22222）的22222端口就可以了可能需要点2次连接

protected void wDZ(object sender, EventArgs e)
{
if (iXdh.Text == "" || eEpm.Text.Length < 7 || ZHS.Text == "") return;
PortForward gYP = new PortForward();
gYP.Start(llH.Text, int.Parse(ZHS.Text), eEpm.Text, int.Parse(iXdh.Text));
}

protected void vJNsE(object sender, EventArgs e)
{
PortForward gYP = new PortForward();
gYP.lyTOK();

}
protected void tYoZ(object sender, EventArgs e)
{
}
}

public class PortForward
{
public string Localaddress;
public int LocalPort;
public string RemoteAddress;
public int RemotePort;
string type;
Socket ltcpClient;
Socket rtcpClient;
Socket server;
byte[] DPrPL = new byte[2048];
byte[] wvZv = new byte[2048];
public struct session
{
public Socket rdel;
public Socket ldel;
public int llen;
public int rlen;
}
public static IPEndPoint mtJ(string host, int port)
{
IPEndPoint iep = null;
IPHostEntry aGN = Dns.Resolve(host);
IPAddress rmt = aGN.AddressList[0];
iep = new IPEndPoint(rmt, port);
return iep;
}
public void Start(string Rip, int Rport, string lip, int lport)
{
try
{
LocalPort = lport;
RemoteAddress = Rip;
RemotePort = Rport;
Localaddress = lip;
rtcpClient = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
ltcpClient = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
rtcpClient.BeginConnect(mtJ(RemoteAddress, RemotePort), new AsyncCallback(iiGFO), rtcpClient);
}
catch (Exception ex) { }
}

protected void iiGFO(IAsyncResult ar)
{
try
{
session RKXy = new session();
RKXy.ldel = ltcpClient;
RKXy.rdel = rtcpClient;
ltcpClient.BeginConnect(mtJ(Localaddress, LocalPort), new AsyncCallback(VTp), RKXy);
}
catch (Exception ex) { }
}

protected void VTp(IAsyncResult ar)
{
try
{
session RKXy = (session)ar.AsyncState;
ltcpClient.EndConnect(ar);
RKXy.rdel.BeginReceive(DPrPL, 0, DPrPL.Length, SocketFlags.None, new AsyncCallback(LFYM), RKXy);
RKXy.ldel.BeginReceive(wvZv, 0, wvZv.Length, SocketFlags.None, new AsyncCallback(xPS), RKXy);
}
catch (Exception ex) { }
}
private void LFYM(IAsyncResult ar)
{
try
{
session RKXy = (session)ar.AsyncState;
int Ret = RKXy.rdel.EndReceive(ar);
if (Ret > 0)
ltcpClient.BeginSend(DPrPL, 0, Ret, SocketFlags.None, new AsyncCallback(JTcp), RKXy);
else lyTOK();
}
catch (Exception ex) { }
}
private void JTcp(IAsyncResult ar)
{
try
{
session RKXy = (session)ar.AsyncState;
RKXy.ldel.EndSend(ar);
RKXy.rdel.BeginReceive(DPrPL, 0, DPrPL.Length, SocketFlags.None, new AsyncCallback(this.LFYM), RKXy);
}
catch (Exception ex) { }
}
private void xPS(IAsyncResult ar)
{
try
{
session RKXy = (session)ar.AsyncState;
int Ret = RKXy.ldel.EndReceive(ar);
if (Ret > 0)
RKXy.rdel.BeginSend(wvZv, 0, Ret, SocketFlags.None, new AsyncCallback(IZU), RKXy);
else lyTOK();
}
catch (Exception ex) { }
}
private void IZU(IAsyncResult ar)
{
try
{
session RKXy = (session)ar.AsyncState;
RKXy.rdel.EndSend(ar);
RKXy.ldel.BeginReceive(wvZv, 0, wvZv.Length, SocketFlags.None, new AsyncCallback(this.xPS), RKXy);
}
catch (Exception ex) { }
}
public void lyTOK()
{
try
{
if (ltcpClient != null)
{
ltcpClient.Close();
}
if (rtcpClient != null)
rtcpClient.Close();
}
catch (Exception ex) { }
}
}
}