src/ddns/system.py

   1 #!/usr/bin/python
   2 ###############################################################################
   3 #                                                                             #
   4 # ddns - A dynamic DNS client for IPFire                                      #
   5 # Copyright (C) 2012 IPFire development team                                  #
   6 #                                                                             #
   7 # This program is free software: you can redistribute it and/or modify        #
   8 # it under the terms of the GNU General Public License as published by        #
   9 # the Free Software Foundation, either version 3 of the License, or           #
  10 # (at your option) any later version.                                         #
  11 #                                                                             #
  12 # This program is distributed in the hope that it will be useful,             #
  13 # but WITHOUT ANY WARRANTY; without even the implied warranty of              #
  14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               #
  15 # GNU General Public License for more details.                                #
  16 #                                                                             #
  17 # You should have received a copy of the GNU General Public License           #
  18 # along with this program.  If not, see <http://www.gnu.org/licenses/>.       #
  19 #                                                                             #
  20 ###############################################################################
  21
  22 import base64
  23 import re
  24 import socket
  25 import urllib
  26 import urllib2
  27
  28 from __version__ import CLIENT_VERSION
  29 from .errors import *
  30 from i18n import _
  31
  32 # Initialize the logger.
  33 import logging
  34 logger = logging.getLogger("ddns.system")
  35 logger.propagate = 1
  36
  37 class DDNSSystem(object):
  38         """
  39                 The DDNSSystem class adds a layer of abstraction
  40                 between the ddns software and the system.
  41         """
  42
  43         # The default useragent.
  44         USER_AGENT = "IPFireDDNSUpdater/%s" % CLIENT_VERSION
  45
  46         def __init__(self, core):
  47                 # Connection to the core of the program.
  48                 self.core = core
  49
  50         @property
  51         def proxy(self):
  52                 proxy = self.core.settings.get("proxy")
  53
  54                 # Strip http:// at the beginning.
  55                 if proxy and proxy.startswith("http://"):
  56                         proxy = proxy[7:]
  57
  58                 return proxy
  59
  60         def _guess_external_ip_address(self, url, timeout=10):
  61                 """
  62                         Sends a request to an external web server
  63                         to determine the current default IP address.
  64                 """
  65                 try:
  66                         response = self.send_request(url, timeout=timeout)
  67
  68                 # If the server could not be reached, we will return nothing.
  69                 except DDNSNetworkError:
  70                         return
  71
  72                 if not response.code == 200:
  73                         return
  74
  75                 match = re.search(r"^Your IP address is: (.*)$", response.read())
  76                 if match is None:
  77                         return
  78
  79                 return match.group(1)
  80
  81         def guess_external_ipv6_address(self):
  82                 """
  83                         Sends a request to the internet to determine
  84                         the public IPv6 address.
  85                 """
  86                 return self._guess_external_ip_address("http://checkip6.dns.lightningwirelabs.com")
  87
  88         def guess_external_ipv4_address(self):
  89                 """
  90                         Sends a request to the internet to determine
  91                         the public IPv4 address.
  92                 """
  93                 return self._guess_external_ip_address("http://checkip4.dns.lightningwirelabs.com")
  94
  95         def send_request(self, url, method="GET", data=None, username=None, password=None, timeout=30):
  96                 assert method in ("GET", "POST")
  97
  98                 # Add all arguments in the data dict to the URL and escape them properly.
  99                 if method == "GET" and data:
 100                         query_args = self._format_query_args(data)
 101                         data = None
 102
 103                         if "?" in url:
 104                                 url = "%s&%s" % (url, query_args)
 105                         else:
 106                                 url = "%s?%s" % (url, query_args)
 107
 108                 logger.debug("Sending request (%s): %s" % (method, url))
 109                 if data:
 110                         logger.debug("  data: %s" % data)
 111
 112                 req = urllib2.Request(url, data=data)
 113
 114                 if username and password:
 115                         basic_auth_header = self._make_basic_auth_header(username, password)
 116                         req.add_header("Authorization", "Basic %s" % basic_auth_header)
 117
 118                 # Set the user agent.
 119                 req.add_header("User-Agent", self.USER_AGENT)
 120
 121                 # All requests should not be cached anywhere.
 122                 req.add_header("Pragma", "no-cache")
 123
 124                 # Set the upstream proxy if needed.
 125                 if self.proxy:
 126                         logger.debug("Using proxy: %s" % self.proxy)
 127
 128                         # Configure the proxy for this request.
 129                         req.set_proxy(self.proxy, "http")
 130
 131                 assert req.get_method() == method
 132
 133                 logger.debug(_("Request header:"))
 134                 for k, v in req.headers.items():
 135                         logger.debug("  %s: %s" % (k, v))
 136
 137                 try:
 138                         resp = urllib2.urlopen(req, timeout=timeout)
 139
 140                         # Log response header.
 141                         logger.debug(_("Response header:"))
 142                         for k, v in resp.info().items():
 143                                 logger.debug("  %s: %s" % (k, v))
 144
 145                         # Return the entire response object.
 146                         return resp
 147
 148                 except urllib2.HTTPError, e:
 149                         # 503 - Service Unavailable
 150                         if e.code == 503:
 151                                 raise DDNSServiceUnavailableError
 152
 153                         # Raise all other unhandled exceptions.
 154                         raise
 155
 156                 except urllib2.URLError, e:
 157                         if e.reason:
 158                                 # Network Unreachable (e.g. no IPv6 access)
 159                                 if e.reason.errno == 101:
 160                                         raise DDNSNetworkUnreachableError
 161                                 elif e.reason.errno == 111:
 162                                         raise DDNSConnectionRefusedError
 163
 164                         # Raise all other unhandled exceptions.
 165                         raise
 166
 167                 except socket.timeout, e:
 168                         logger.debug(_("Connection timeout"))
 169
 170                         raise DDNSConnectionTimeoutError
 171
 172         def _format_query_args(self, data):
 173                 args = []
 174
 175                 for k, v in data.items():
 176                         arg = "%s=%s" % (k, urllib.quote(v))
 177                         args.append(arg)
 178
 179                 return "&".join(args)
 180
 181         def _make_basic_auth_header(self, username, password):
 182                 authstring = "%s:%s" % (username, password)
 183
 184                 # Encode authorization data in base64.
 185                 authstring = base64.encodestring(authstring)
 186
 187                 # Remove any newline characters.
 188                 authstring = authstring.replace("\n", "")
 189
 190                 return authstring
 191
 192         def get_address(self, proto):
 193                 assert proto in ("ipv6", "ipv4")
 194
 195                 # Check if the external IP address should be guessed from
 196                 # a remote server.
 197                 guess_ip = self.core.settings.get("guess_external_ip", "true")
 198
 199                 # If the external IP address should be used, we just do
 200                 # that.
 201                 if guess_ip in ("true", "yes", "1"):
 202                         if proto == "ipv6":
 203                                 return self.guess_external_ipv6_address()
 204
 205                         elif proto == "ipv4":
 206                                 return self.guess_external_ipv4_address()
 207
 208                 # XXX TODO
 209                 assert False
 210
 211         def resolve(self, hostname, proto=None):
 212                 addresses = []
 213
 214                 if proto is None:
 215                         family = 0
 216                 elif proto == "ipv6":
 217                         family = socket.AF_INET6
 218                 elif proto == "ipv4":
 219                         family = socket.AF_INET
 220                 else:
 221                         raise ValueError("Protocol not supported: %s" % proto)
 222
 223                 # Resolve the host address.
 224                 try:
 225                         response = socket.getaddrinfo(hostname, None, family)
 226                 except socket.gaierror, e:
 227                         # Name or service not known
 228                         if e.errno == -2:
 229                                 return []
 230
 231                         raise
 232
 233                 # Handle responses.
 234                 for family, socktype, proto, canonname, sockaddr in response:
 235                         # IPv6
 236                         if family == socket.AF_INET6:
 237                                 address, port, flow_info, scope_id = sockaddr
 238
 239                                 # Only use the global scope.
 240                                 if not scope_id == 0:
 241                                         continue
 242
 243                         # IPv4
 244                         elif family == socket.AF_INET:
 245                                 address, port = sockaddr
 246
 247                         # Ignore everything else...
 248                         else:
 249                                 continue
 250
 251                         # Add to repsonse list if not already in there.
 252                         if not address in addresses:
 253                                 addresses.append(address)
 254
 255                 return addresses