59dc218868ae86467b43afc4a51d8a1d2bc23f1d
[oddments/ddns.git] / 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_ipv6_address(self):
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("http://checkip6.dns.lightningwirelabs.com", timeout=10)
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_ipv4_address(self):
82                 """
83                         Sends a request to the internet to determine
84                         the public IP address.
85
86                         XXX does not work for IPv6.
87                 """
88                 try:
89                         response = self.send_request("http://checkip4.dns.lightningwirelabs.com", timeout=10)
90
91                 # If the server could not be reached, we will return nothing.
92                 except DDNSNetworkError:
93                         return
94
95                 if response.code == 200:
96                         match = re.search(r"Your IP address is: (\d+.\d+.\d+.\d+)", response.read())
97                         if match is None:
98                                 return
99
100                         return match.group(1)
101
102         def send_request(self, url, method="GET", data=None, username=None, password=None, timeout=30):
103                 assert method in ("GET", "POST")
104
105                 # Add all arguments in the data dict to the URL and escape them properly.
106                 if method == "GET" and data:
107                         query_args = self._format_query_args(data)
108                         data = None
109
110                         url = "%s?%s" % (url, query_args)
111
112                 logger.debug("Sending request (%s): %s" % (method, url))
113                 if data:
114                         logger.debug("  data: %s" % data)
115
116                 req = urllib2.Request(url, data=data)
117
118                 if username and password:
119                         basic_auth_header = self._make_basic_auth_header(username, password)
120                         print repr(basic_auth_header)
121                         req.add_header("Authorization", "Basic %s" % basic_auth_header)
122
123                 # Set the user agent.
124                 req.add_header("User-Agent", self.USER_AGENT)
125
126                 # All requests should not be cached anywhere.
127                 req.add_header("Pragma", "no-cache")
128
129                 # Set the upstream proxy if needed.
130                 if self.proxy:
131                         logger.debug("Using proxy: %s" % self.proxy)
132
133                         # Configure the proxy for this request.
134                         req.set_proxy(self.proxy, "http")
135
136                 assert req.get_method() == method
137
138                 logger.debug(_("Request header:"))
139                 for k, v in req.headers.items():
140                         logger.debug("  %s: %s" % (k, v))
141
142                 try:
143                         resp = urllib2.urlopen(req, timeout=timeout)
144
145                         # Log response header.
146                         logger.debug(_("Response header:"))
147                         for k, v in resp.info().items():
148                                 logger.debug("  %s: %s" % (k, v))
149
150                         # Return the entire response object.
151                         return resp
152
153                 except urllib2.HTTPError, e:
154                         # 503 - Service Unavailable
155                         if e.code == 503:
156                                 raise DDNSServiceUnavailableError
157
158                         # Raise all other unhandled exceptions.
159                         raise
160
161                 except urllib2.URLError, e:
162                         if e.reason:
163                                 # Network Unreachable (e.g. no IPv6 access)
164                                 if e.reason.errno == 101:
165                                         raise DDNSNetworkUnreachableError
166                                 elif e.reason.errno == 111:
167                                         raise DDNSConnectionRefusedError
168
169                         # Raise all other unhandled exceptions.
170                         raise
171
172                 except socket.timeout, e:
173                         logger.debug(_("Connection timeout"))
174
175                         raise DDNSConnectionTimeoutError
176
177         def _format_query_args(self, data):
178                 args = []
179
180                 for k, v in data.items():
181                         arg = "%s=%s" % (k, urllib.quote(v))
182                         args.append(arg)
183
184                 return "&".join(args)
185
186         def _make_basic_auth_header(self, username, password):
187                 authstring = "%s:%s" % (username, password)
188
189                 # Encode authorization data in base64.
190                 authstring = base64.encodestring(authstring)
191
192                 # Remove any newline characters.
193                 authstring = authstring.replace("\n", "")
194
195                 return authstring
196
197         def get_address(self, proto):
198                 assert proto in ("ipv6", "ipv4")
199
200                 # Check if the external IP address should be guessed from
201                 # a remote server.
202                 guess_ip = self.core.settings.get("guess_external_ip", "true")
203
204                 # If the external IP address should be used, we just do
205                 # that.
206                 if guess_ip in ("true", "yes", "1"):
207                         if proto == "ipv6":
208                                 return self.guess_external_ipv6_address()
209
210                         elif proto == "ipv4":
211                                 return self.guess_external_ipv4_address()
212
213                 # XXX TODO
214                 assert False
215
216         def resolve(self, hostname, proto=None):
217                 addresses = []
218
219                 if proto is None:
220                         family = 0
221                 elif proto == "ipv6":
222                         family = socket.AF_INET6
223                 elif proto == "ipv4":
224                         family = socket.AF_INET
225                 else:
226                         raise ValueError("Protocol not supported: %s" % proto)
227
228                 # Resolve the host address.
229                 try:
230                         response = socket.getaddrinfo(hostname, None, family)
231                 except socket.gaierror, e:
232                         # Name or service not known
233                         if e.errno == -2:
234                                 return []
235
236                         raise
237
238                 # Handle responses.
239                 for family, socktype, proto, canonname, sockaddr in response:
240                         # IPv6
241                         if family == socket.AF_INET6:
242                                 address, port, flow_info, scope_id = sockaddr
243
244                                 # Only use the global scope.
245                                 if not scope_id == 0:
246                                         continue
247
248                         # IPv4
249                         elif family == socket.AF_INET:
250                                 address, port = sockaddr
251
252                         # Ignore everything else...
253                         else:
254                                 continue
255
256                         # Add to repsonse list if not already in there.
257                         if not address in addresses:
258                                 addresses.append(address)
259
260                 return addresses