port_forward.py

#!/usr/bin/env python
# forward a local port
# usage $ python port_forward.py --local-port=8800

import argparse
import asyncore
import socket
#import sys
#sys.argv = ['--local-port=8800']

LOCAL_SERVER_HOST = 'localhost'
REMOTE_SERVER_HOST = 'www.gentoo.org'
BUFSIZE = 4096

class PortForwarder(asyncore.dispatcher):
    def __init__(self, ip, port, remoteip, remoteport, backlog=5):
        asyncore.dispatcher.__init__(self)
        self.remoteip=remoteip
        self.remoteport=remoteport
        self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
        self.set_reuse_addr()
        self.bind((ip,port))
        self.listen(backlog)
    def handle_accept(self):
        conn, addr = self.accept()
        print "Connected to:", addr
        Sender(Receiver(conn),self.remoteip,self.remoteport)

class Receiver(asyncore.dispatcher):
    def __init__(self,conn):
        asyncore.dispatcher.__init__(self, conn)
        self.from_remote_buffer=''
        self.to_remote_buffer=''
        self.sender=None
    def handle_connect(self):
        pass
    def handle_read(self):
        read = self.recv(BUFSIZE)
        self.from_remote_buffer += read
    def writable(self):
        return (len(self.to_remote_buffer) > 0)
    def handle_write(self):
        sent = self.send(self.to_remote_buffer)
        self.to_remote_buffer = self.to_remote_buffer[sent:]
    def handle_close(self):
        self.close()
        if self.sender:
            self.sender.close()

class Sender(asyncore.dispatcher):
    def __init__(self, receiver, remoteaddr, remoteport):
        asyncore.dispatcher.__init__(self)
        self.receiver=receiver
        receiver.sender = self
        self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
        self.connect((remoteaddr, remoteport))
    def handle_connect(self):
        pass
    def handle_read(self):
        read = self.recv(BUFSIZE)
        self.receiver.to_remote_buffer += read
    def writable(self):
        return (len(self.receiver.from_remote_buffer) > 0)
    def handle_write(self):
        sent = self.send(self.receiver.from_remote_buffer)
        self.receiver.from_remote_buffer = \
                                         self.receiver.from_remote_buffer[sent:]
    def handle_close(self):
        self.close()
        self.receiver.close()

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description='Port forwarding example')
    parser.add_argument('--local-host', action="store", dest="local_host", \
                        default=LOCAL_SERVER_HOST)
    parser.add_argument('--local-port', action="store", dest="local_port", \
                        type=int, required=True)
    parser.add_argument('--remote-host', action="store", \
                        dest="remote_host", default=REMOTE_SERVER_HOST)
    parser.add_argument('--remote-port', action="store", dest="remote_port", \
                        type=int, default=80)
    given_args = parser.parse_args()
    local_host, remote_host = given_args.local_host, given_args.remote_host
    local_port, remote_port = given_args.local_port, given_args.remote_port
    print "Starting port forwarding local %s:%s => remote %s:%s" % \
          (local_host, local_port, remote_host, remote_port)
    PortForwarder(local_host, local_port, remote_host, remote_port)
    asyncore.loop()
"""
Empty Page!
If you expected a real website instead something must be wrong. :-(
If you also got an SSL hostname mismatch, your browser doesn't
properly support SNI (e.g. IE8 on Windows XP).

was expecting Gentoo.org
I receive this on FF and Links
"""