# ------------------------------------------------------------

 # proxy_getter

 #   

 # Aquire the correct proxy settings of the current machine

 #

 # Autor: Mihai Bartha, <mihai.bartha@ait.ac.at>       

 #

 # Copyright 2013-2014 X-Net and AIT Austrian Institute of Technology

 # 

 # 

 #     X-Net Services GmbH

 #     Elisabethstrasse 1

 #     4020 Linz

 #     AUSTRIA

 #     https://www.x-net.at

 # 

 #     AIT Austrian Institute of Technology

 #     Donau City Strasse 1

 #     1220 Wien

 #     AUSTRIA

 #     http://www.ait.ac.at

 # 

 # 

 # Licensed under the Apache License, Version 2.0 (the "License");

 # you may not use this file except in compliance with the License.

 # You may obtain a copy of the License at

 # 

 #    http://www.apache.org/licenses/LICENSE-2.0

 # 

 # Unless required by applicable law or agreed to in writing, software

 # distributed under the License is distributed on an "AS IS" BASIS,

 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 # See the License for the specific language governing permissions and

 # limitations under the License.

 # ------------------------------------------------------------

 import socket

 import os

 import httplib

 import sys

 import _winreg

 import re

 DNS_WPAD_FILENAME = "wpad.dat"

 def check_for_wpad_file(server, path):

     wpad_url = "http://%s/%s"%(server, path)

     print "checking", wpad_url

     try:

         conn = httplib.HTTPConnection(server)

         conn.request("HEAD", "/%s"%path)

         r = conn.getresponse()

         if r.status == 200:

             return wpad_url

     except Exception, e:

         return None

     return None

 def get_wpad_server_searchlist():

     #get fully-qualified hostname

     fqhn = socket.getfqdn().split(" ")[0]

     #do we really have a fully-qualified name?

     #if not, linux offers a second possibility

     if fqhn.count(".") == 0 and os.name == 'posix':

         #weird method to get own ip address and fqhn 

         s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)

         s.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)

         s.connect(('<broadcast>', 0))

         my_ip = s.getsockname()[0]

         s.close()

         fqhn = socket.gethostbyaddr(my_ip)[0]

     parts = fqhn.split(".")

     if len(parts) < 3:

         return []

     servers = []

     parts[0] = "wpad"

     servers.append(".".join(parts))

     parts = parts[0:1]+parts[2:]

     #not correct for some suffixes, but everyone does it that way, see wikipedia for details

     while len(parts) >= 3:

         servers.append(".".join(parts))

         parts = parts[0:1]+parts[2:]

     return servers

 def search_for_wpad_url():

     #TODO: According to RFC we should check DHCP first, but it isn't used often

     #check most common case first

     wpad_server = "wpad"

     wpad_url = check_for_wpad_file(wpad_server, DNS_WPAD_FILENAME)

     if wpad_url:

         return wpad_url

     #wpad DNS search procedure

     possible_wpad_servers = get_wpad_server_searchlist()

     for server in possible_wpad_servers:

         wpad_url = check_for_wpad_file(server, DNS_WPAD_FILENAME)

         if wpad_url:

             return wpad_url

     #no wpad url found

     return None

 def getProxySettings():

     # try to autodetect domain wpad file

     wpad_url = search_for_wpad_url()

     if wpad_url:

         return {'ProxyAutoConfigURL': wpad_url}

     # get Proxy settings from registry      

     aReg = _winreg.ConnectRegistry(None,_winreg.HKEY_CURRENT_USER)

     aKey = _winreg.OpenKey(aReg, r"Software\Microsoft\Windows\CurrentVersion\Internet Settings")

     _, valueCount, _ = _winreg.QueryInfoKey(aKey)

     reg_entries = dict()

     for i in range(valueCount):                                           

         try:

             n,v,_ = _winreg.EnumValue(aKey,i)

             reg_entries[n] = v

         except EnvironmentError:                                               

             break

     _winreg.CloseKey(aKey)

     # return configured WPAD url

     if 'AutoConfigURL' in reg_entries.keys():

         return {'ProxyAutoConfigURL': reg_entries['AutoConfigURL']}

     # return manually configured proxy

     if 'ProxyEnable' in reg_entries.keys() and reg_entries['ProxyEnable'] == 1:

         proxy_search = re.search(r"(?<=http=)(?P<ProxyServer>.*?)(?=;)", reg_entries['ProxyServer'])

         if proxy_search:

             proxies = proxy_search.groupdict()

             if 'ProxyServer' in proxies.keys(): # found http proxy

                 return {'ProxyServer': proxies['ProxyServer']}  

         return {'ProxyServer': reg_entries['ProxyServer']}

     return None