Example of port forwarding and redirection under TCP/IP protocol in Python

This article mainly introduces the example of port forwarding and redirection implemented by Python under the TCPIP protocol. it is demonstrated by a webpy site with two-way communication ports on the local machine. if you need a friend, refer to the following, we use webpy to write a simple website, listen to port 8080, and return the "Hello, EverET.org" page.

Then we use our forwarding. py to establish two communication pipelines between Port 80 and port 8080 for bidirectional communication.

At this point, we access our server through port 80.

The browser obtains:

Then, we can see the communication content between the browser and webpy in the output result of forwarding. py.

Code:

#!/usr/bin/env pythonimport sys, socket, time, threadingloglock = threading.Lock()def log(msg):  loglock.acquire()  try:    print '[%s]: \n%s\n' % (time.ctime(), msg.strip())    sys.stdout.flush()  finally:    loglock.release()class PipeThread(threading.Thread):  def __init__(self, source, target):    threading.Thread.__init__(self)    self.source = source    self.target = target  def run(self):    while True:      try:        data = self.source.recv(1024)        log(data)        if not data: break        self.target.send(data)      except:        break    log('PipeThread done')class Forwarding(threading.Thread):  def __init__(self, port, targethost, targetport):    threading.Thread.__init__(self)    self.targethost = targethost    self.targetport = targetport    self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)    self.sock.bind(('0.0.0.0', port))    self.sock.listen(10)  def run(self):    while True:      client_fd, client_addr = self.sock.accept()      target_fd = socket.socket(socket.AF_INET, socket.SOCK_STREAM)      target_fd.connect((self.targethost, self.targetport))      log('new connect')      # two direct pipe      PipeThread(target_fd, client_fd).start()      PipeThread(client_fd, target_fd).start()if __name__ == '__main__':  print 'Starting'  import sys  try:    port = int(sys.argv[1])    targethost = sys.argv[2]    try: targetport = int(sys.argv[3])    except IndexError: targetport = port  except (ValueError, IndexError):    print 'Usage: %s port targethost [targetport]' % sys.argv[0]    sys.exit(1)  #sys.stdout = open('forwaring.log', 'w')  Forwarding(port, targethost, targetport).start()