例子,python实现TCP代理服务器的方法。
代码:
# -*- coding: utf-8 -*- ''' filename:rtcp.py @desc: 利用python的socket端口转发,用于远程维护 www.jb200.com 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 stream2nstream : 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)