TcpPortForward.py

#/usr/bin/python env
# -*- coding: utf-8 -*-
'''
filename:TcpPortForward.py
@desc:
利用python的socket端口转发，用于远程维护,Hack
如果连接不到远程，会sleep 36s，最多尝试200(即两小时)

@usage:
./TcpPortForward.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
'''

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: ./TcpPortForward.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)