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 stream2stream为：l:port或c:host:portl: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 socketimport sysimport threadingimport timestreams = [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 1def _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)