Proxy and Port Mapping With Python

import socket
import sys
import thread

def main(setup, error):
    sys.stderr = file(error, 'a')
    for settings in parse(setup):
        thread.start_new_thread(server, settings)
    lock = thread.allocate_lock()
    lock.acquire()
    lock.acquire()

def parse(setup):
    settings = list()
    for line in file(setup):
        parts = line.split()
        settings.append((parts[0], int(parts[1]), int(parts[2])))
    return settings

def server(*settings):
    try:
        dock_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        dock_socket.bind(('', settings[2]))
        dock_socket.listen(5)
        while True:
            client_socket = dock_socket.accept()[0]
            server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
            server_socket.connect((settings[0], settings[1]))
            thread.start_new_thread(forward, (client_socket, server_socket))
            thread.start_new_thread(forward, (server_socket, client_socket))
    finally:
        thread.start_new_thread(server, settings)

def forward(source, destination):
    string = ' '
    while string:
        string = source.recv(1024)
        if string:
            destination.sendall(string)
        else:
            source.shutdown(socket.SHUT_RD)
            destination.shutdown(socket.SHUT_WR)

if __name__ == '__main__':
    main('proxy.ini', 'error.log')

'''
microproxy.py

A very low-level, simple-minded proxy that just forwards the data.

You can do whatever you please with this code, knock yourself out.

btw, the comments were erased on purpose.

If you wish to understand the code, google 3 things:
1. python socket example
2. python regular excodessions
3. python thread

'''

import re
import socket
from threading import *

regex = re.compile(r'http://(.*?)/', re.IGNORECASE)

class ConnectionThread(Thread):
  def __init__(self, (conn,addr)):
    self.conn = conn
    self.addr = addr
    Thread.__init__(self)
 
  def run(self):
    data = self.conn.recv(1024*1024)
   
    host = regex.search(data).groups()[0]
   
    request = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    request.settimeout(6)
    request.connect((host,80))
    request.send(data)
   
    reply = ''
    try:
      while 1:
        temp = request.recv(1024)
       
        if ('' == temp):
          break
       
        reply += temp
       
    except Exception:
      pass
   
    self.conn.send(reply)
    self.conn.close()



class ProxyThread(Thread):
  def __init__(self, port):
    self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    self.sock.bind(('localhost', port))
    Thread.__init__(self)
 
  def run(self):
    self.sock.listen(10)
    while 1:
      temp = ConnectionThread(self.sock.accept())
      temp.start()


if __name__ == "__main__":
  a = ProxyThread(8000)
  a.start()
  print "Started a proxy on port 8000"