python_proxy

唯一目的：短平快
语言：python
模块：sys,socket,threading

服务器IP：192.168.1.6
中间机器：192.168.138.128
客户端IP：192.168.1.6
服务器和客户端都是真实物理机，中间机器是VMware虚拟机。用三个不同机器效果也一样。

#coding=utf-8
import sys
import threading
import socket

def main():
    if len(sys.argv[1:])!=5:
        print "Example: python tcp_proxy 127.0.0.1 9999 10.12.131.1 90000 True"
        sys.exit(0)
    local_host=sys.argv[1]
    local_port=int(sys.argv[2])

    remote_host=sys.argv[3]
    remote_port=int(sys.argv[4])

    receive_first=sys.argv[5]

    if "True" in receive_first:
        receive_first=True
    else:
        receive_first=False

    server_loop(local_host,local_port,remote_host,remote_port,receive_first)


def server_loop(local_host,local_port,remote_host,remote_port,receive_first):

    server=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
    try:
        server.bind((local_host,local_port))
    except:
        print "failed!!,check the sockets or correct permisssion!"
        sys.exit(0)
    print "listening on %s,%d" % (local_host,local_port)

    server.listen(5)

    while True:
        client_socekt,addr=server.accept()

        print "received incoming connection from %s,%d"% (addr[0],addr[1])

        proxy_thread=threading.Thread(target=proxy_handler,args=(client_socekt,remote_host,remote_port,receive_first))

        proxy_thread.start()


def proxy_handler(client_socket,remote_host,remote_port,receive_first):

    #下面两句连接服务器，获得socket对象！
    remote_socket=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
    remote_socket.connect((remote_host,remote_port))

    while True:
        #如果接受到来自客户的数据，就转发到服务器
        local_buffer=receive_from(client_socket)
        if len(local_buffer):
            print "received %d bytes from localhost" % len(local_buffer)
            remote_socket.send(local_buffer)
            print "send to remote >>>"

        #如果接受到来自服务器的数据，就转发到客户端
        remote_buffer=receive_from(remote_socket)
        if len(remote_buffer):
            print "received %d bytes from remote ." % (len(remote_buffer))
            client_socket.send(remote_buffer)
            print "send to localhost <<<"
        #如果双方都没数据发过来，哈哈，那我就关闭，睡觉喽。  
        if not len(local_buffer) or not len(remote_buffer):
            client_socket.close()
            remote_socket.close()
            print "no more information, closing connnection !!"

            break

#接收发送端发送的所有消息       
def receive_from(connection):
    buffer=""
    connection.settimeout(2)
    try:
        while True:
            data=connection.recv(4096)
            if not data:
                break
            buffer+=data
    except:
        pass
    return buffer

main()

代理可用来突破分段网络：