Python implements a simple Proxy Server

This article mainly introduces Python's simple proxy server, which can implement the Basic packet forwarding function of the proxy server. It has some reference value, for more information about how to implement a simple proxy server in Python, see the example in this article. Share it with you for your reference. The details are as follows:

It has a simple management function. After running, telnet localhost 9000 port can be managed. The main function is packet forwarding. If there is a bridge server, it can be used for Internet access to the Intranet, which is still very useful.

#/bin/env python #coding:utf-8 import socket,select,sys,time import thread s_list = [] def loop(cs,addr,s_ip,s_port):  print '%s %d connected.' % addr  ts = socket.socket()  try:   ts.connect((s_ip,s_port))  except:   cs.close()   print '%s %d closed.' % addr   sys.exit(0)  while True:   rl,wl,xl = select.select([cs.fileno(),ts.fileno()],[],[cs.fileno(),ts.fileno()])   if len(xl) > 0:    cs.close()    ts.close()    print '%s %d closed.' % addr    sys.exit(0)   if len(rl) > 0:    if rl[0] == cs.fileno():     rs = ts     ws = cs    else:     rs = cs     ws = ts    try:     buffer = ws.recv(10000)     if len(buffer) == 0:      raise     rs.send(buffer)    except:     rs.close()     ts.close()     print '%s %d closed.' % addr     sys.exit(0) def mainserver(l_port,s_ip,s_port):  global s_list  try:   ss = socket.socket()   ss.bind(('0.0.0.0',l_port))   ss.listen(10)   s_list.append((l_port,s_ip,s_port))    except:   sys.exit(0)  while True:   cs,addr = ss.accept()   thread.start_new_thread(loop,(cs,addr,s_ip,s_port)) def manager(l_port):  global start,s_list  ss = socket.socket()  ss.bind(('0.0.0.0',l_port))  ss.listen(10)  while True:   cs,addr = ss.accept()   cs.send("""trans server 1.0\r\ntype 'help' to get help\r\n""")  buffer = ''   while True:    buf = cs.recv(10000)    if len(buf) == 0:     cs.close()     break    if buf[-1] not in ('\r','\n'):     buffer += buf     continue    buffer += buf    cmd = buffer.strip()    buffer = ''    if cmd == 'exit':     cs.close()     break    elif cmd == 'stop':     start = 0     cs.close()     sys.exit(0)    elif cmd == 'list':     b = ''     for l in s_list:      b += '%4d %s:%d\r\n' % l     if len(b) > 0:      cs.send(b)    elif cmd in ('help','?'):     cs.send("""-------------------------------------------\rexit\r  exit telnet\r start localport serverip:serverport\r  start a new server\r list\r  list all server\r -------------------------------------------\r """)    else:     cmds = cmd.split(" ",1)     if len(cmds) > 1 and cmds[0] == 'start':      args = cmds[1].strip().split(" ",1)      if len(args) != 2:       cs.send('start localport serverip:serverport\r\n')       continue      arg = args[1].split(":",1)      if len(arg) != 2:       cs.send('start localport serverip:serverport\r\n')       continue      try:       l_port = int(args[0])       s_ip = arg[0]       s_port = int(arg[1])      except:       cs.send('start localport serverip:serverport\r\n')       continue      thread.start_new_thread(mainserver,(l_port,s_ip,s_port))      cs.send('start OK!\r\n')     else:      cs.send('no command [%s]\r\n' % cmd)      continue def main():  global start  if len(sys.argv) == 3:   try:    l_port = int(sys.argv[1])    s_ip,s_port = sys.argv[2].split(":")    s_port = int(s_port)    thread.start_new_thread(mainserver,(l_port,s_ip,s_port))   except:    pass  start = 1  thread.start_new_thread(manager,(9000,))  while start:   time.sleep(1) if __name__ == '__main__':  start = 0  main()

I hope this article will help you with Python programming.