python实现简单的TCP代理服务器

本文实例讲述了python实现简单的TCP代理服务器的方法，分享给大家供大家参考。

具体实现代码如下：

    # -*- coding: utf-8 -*-

    '''
    filename:rtcp.py
    @desc:
    利用python的socket端口转发，用于远程维护
    如果连接不到远程，会sleep 36s，最多尝试200(即两小时)

    @usage:
    ./rtcp.py stream1 stream2
    stream为：l:port或c:host:port
    l:port表示监听指定的本地端口
    c:host:port表示监听远程指定的端口

    @author: watercloud, zd, knownsec team
    @web: www.knownsec.com, blog.knownsec.com
    @date: 2009-7
    '''

    import socket
    import sys
    import threading
    import time

    streams = [None, None] # 存放需要进行数据转发的两个数据流（都是SocketObj对象）
    debug = 1 # 调试状态 0 or 1

    def _usage():
     print 'Usage: ./rtcp.py stream1 stream2\nstream : l:port or c:host:port'

    def _get_another_stream(num):
     '''
     从streams获取另外一个流对象，如果当前为空，则等待
     '''
     if num == 0:
     num = 1
     elif num == 1:
     num = 0
     else:
     raise "ERROR"

     while True:
     if streams[num] == 'quit':
      print("can't connect to the target, quit now!")
      sys.exit(1)

     if streams[num] != None:
      return streams[num]
     else:
      time.sleep(1)

    def _xstream(num, s1, s2):
     '''
     交换两个流的数据
     num为当前流编号,主要用于调试目的，区分两个回路状态用。
     '''
     try:
     while True:
      #注意，recv函数会阻塞，直到对端完全关闭（close后还需要一定时间才能关闭，最快关闭方法是shutdow）
      buff = s1.recv(1024)
      if debug > 0:
      print num,"recv"
      if len(buff) == 0: #对端关闭连接，读不到数据
      print num,"one closed"
      break
      s2.sendall(buff)
      if debug > 0:
      print num,"sendall"
     except :
     print num,"one connect closed."

     try:
     s1.shutdown(socket.SHUT_RDWR)
     s1.close()
     except:
     pass

     try:
     s2.shutdown(socket.SHUT_RDWR)
     s2.close()
     except:
     pass

     streams[0] = None
     streams[1] = None
     print num, "CLOSED"

    def _server(port, num):
     '''
     处理服务情况,num为流编号（第0号还是第1号）
     '''
     srv = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
     srv.bind(('0.0.0.0', port))
     srv.listen(1)
     while True:
     conn, addr = srv.accept()
     print "connected from:", addr
     streams[num] = conn # 放入本端流对象
     s2 = _get_another_stream(num) # 获取另一端流对象
     _xstream(num, conn, s2)

    def _connect(host, port, num):
     ''' 处理连接，num为流编号（第0号还是第1号）

     @note: 如果连接不到远程，会sleep 36s，最多尝试200(即两小时)
     '''
     not_connet_time = 0
     wait_time = 36
     try_cnt = 199
     while True:
     if not_connet_time > try_cnt:
      streams[num] = 'quit'
      print('not connected')
      return None

     conn = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
     try:
      conn.connect((host, port))
     except Exception, e:
      print ('can not connect %s:%s!' % (host, port))
      not_connet_time += 1
      time.sleep(wait_time)
      continue

     print "connected to %s:%i" % (host, port)
     streams[num] = conn #放入本端流对象
     s2 = _get_another_stream(num) #获取另一端流对象
     _xstream(num, conn, s2)


    if __name__ == '__main__':
     if len(sys.argv) != 3:
     _usage()
     sys.exit(1)
     tlist = [] # 线程列表，最终存放两个线程对象
     targv = [sys.argv[1], sys.argv[2] ]
     for i in [0, 1]:
     s = targv[i] # stream描述 c:ip:port 或 l:port
     sl = s.split(':')
     if len(sl) == 2 and (sl[0] == 'l' or sl[0] == 'L'): # l:port
      t = threading.Thread(target=_server, args=(int(sl[1]), i))
      tlist.append(t)
     elif len(sl) == 3 and (sl[0] == 'c' or sl[0] == 'C'): # c:host:port
      t = threading.Thread(target=_connect, args=(sl[1], int(sl[2]), i))
      tlist.append(t)
     else:
      _usage()
      sys.exit(1)

     for t in tlist:
     t.start()
     for t in tlist:
     t.join()
     sys.exit(0)

完整实例代码点击此处本站下载。

希望本文所述对大家的Python程序设计有所帮助。