Python implements a simple TCP proxy server

This article describes the Python implementation of a simple TCP Proxy server method, share to everyone for your reference.

The specific implementation code is as follows:

#-*-Coding:utf-8-*-"Filename:rtcp.py@desc: Using Python's socket port forwarding for remote maintenance if the connection is not remote, it will sleep 36s, up to 200 (i.e. two hours) @usage:. /rtcp.py stream1 Stream2stream is: L:port or c:host:portl:port indicates that the listener specifies the local port C:host:port, which listens for remote specified ports @author:watercloud, ZD, Knownsec team@web:www.knownsec.com, blog.knownsec.com@date:2009-7 "Import Socketimport sysimport Threadingimport Timestreams = [None, none] # store two data streams (all Socketobj objects) that require data forwarding debug = 1 # Debug State 0 or 1def _usage (): print ' usage:./rtcp.py s tream1 Stream2\nstream:l:port or C:host:port ' def _get_another_stream (num): "' gets another stream object from streams, and if it is currently empty, wait for ' if num = = 0:num = 1 elif num = = 1:num = 0 else:raise "ERROR" while true:if streams[num] = = ' Quit ': print ("Can ' t connect to th  E Target, quit now! ") Sys.exit (1) if streams[num]! = None:return Streams[num] Else:time.sleep (1) def _xstream (num, s1, s2): "Exchange two streams of data num for Current stream number, mainly used for debugging purposes, distinguish two loop state. "' Try:while True: #注意, the recv function will block until the end of the pair is closed completely (it takes time to close after close, the quickest way to close is Shutdow) buff = S1.RECV (1024x768) If debug > 0:  Print num, "recv" If len (buff) = = 0: #对端关闭连接, cannot read data print num, "one closed" break s2.sendall (Buff) if debug > 0:p Rint 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): ' Processing service , NUM is the stream number (number No. 0 or 1th) ' 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 # put the Stream object s2 = _get_another_stream (num) # Get the other end stream object _xstream (NUM, conn, S2) def _connect (host, Port, Nu m): ' Processing the connection, NUM is the stream number (number No. 0 or 1th) @note: If the connection is not remote, will sleep 36s, up to 200 (i.e. two hours) "Not_connet_time = 0 Wait_time = try_cnt = 1 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 = [] # thread List , eventually storing two thread objects targv = [sys.argv[1], sys.argv[2]] for i in [0, 1]: s = targv[i] # Stream Description C:ip:port or 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:ho St: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)

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Hopefully this article will help you with Python programming.

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