Auto-replace double question marks in request url.
[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_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                         print repr(basic_auth_header)
117                         req.add_header("Authorization", "Basic %s" % basic_auth_header)
118
119                 # Set the user agent.
120                 req.add_header("User-Agent", self.USER_AGENT)
121
122                 # All requests should not be cached anywhere.
123                 req.add_header("Pragma", "no-cache")
124
125                 # Set the upstream proxy if needed.
126                 if self.proxy:
127                         logger.debug("Using proxy: %s" % self.proxy)
128
129                         # Configure the proxy for this request.
130                         req.set_proxy(self.proxy, "http")
131
132                 assert req.get_method() == method
133
134                 logger.debug(_("Request header:"))
135                 for k, v in req.headers.items():
136                         logger.debug("  %s: %s" % (k, v))
137
138                 try:
139                         resp = urllib2.urlopen(req, timeout=timeout)
140
141                         # Log response header.
142                         logger.debug(_("Response header:"))
143                         for k, v in resp.info().items():
144                                 logger.debug("  %s: %s" % (k, v))
145
146                         # Return the entire response object.
147                         return resp
148
149                 except urllib2.HTTPError, e:
150                         # 503 - Service Unavailable
151                         if e.code == 503:
152                                 raise DDNSServiceUnavailableError
153
154                         # Raise all other unhandled exceptions.
155                         raise
156
157                 except urllib2.URLError, e:
158                         if e.reason:
159                                 # Network Unreachable (e.g. no IPv6 access)
160                                 if e.reason.errno == 101:
161                                         raise DDNSNetworkUnreachableError
162                                 elif e.reason.errno == 111:
163                                         raise DDNSConnectionRefusedError
164
165                         # Raise all other unhandled exceptions.
166                         raise
167
168                 except socket.timeout, e:
169                         logger.debug(_("Connection timeout"))
170
171                         raise DDNSConnectionTimeoutError
172
173         def _format_query_args(self, data):
174                 args = []
175
176                 for k, v in data.items():
177                         arg = "%s=%s" % (k, urllib.quote(v))
178                         args.append(arg)
179
180                 return "&".join(args)
181
182         def _make_basic_auth_header(self, username, password):
183                 authstring = "%s:%s" % (username, password)
184
185                 # Encode authorization data in base64.
186                 authstring = base64.encodestring(authstring)
187
188                 # Remove any newline characters.
189                 authstring = authstring.replace("\n", "")
190
191                 return authstring
192
193         def get_address(self, proto):
194                 assert proto in ("ipv6", "ipv4")
195
196                 # Check if the external IP address should be guessed from
197                 # a remote server.
198                 guess_ip = self.core.settings.get("guess_external_ip", "true")
199
200                 # If the external IP address should be used, we just do
201                 # that.
202                 if guess_ip in ("true", "yes", "1"):
203                         if proto == "ipv6":
204                                 return self.guess_external_ipv6_address()
205
206                         elif proto == "ipv4":
207                                 return self.guess_external_ipv4_address()
208
209                 # XXX TODO
210                 assert False
211
212         def resolve(self, hostname, proto=None):
213                 addresses = []
214
215                 if proto is None:
216                         family = 0
217                 elif proto == "ipv6":
218                         family = socket.AF_INET6
219                 elif proto == "ipv4":
220                         family = socket.AF_INET
221                 else:
222                         raise ValueError("Protocol not supported: %s" % proto)
223
224                 # Resolve the host address.
225                 try:
226                         response = socket.getaddrinfo(hostname, None, family)
227                 except socket.gaierror, e:
228                         # Name or service not known
229                         if e.errno == -2:
230                                 return []
231
232                         raise
233
234                 # Handle responses.
235                 for family, socktype, proto, canonname, sockaddr in response:
236                         # IPv6
237                         if family == socket.AF_INET6:
238                                 address, port, flow_info, scope_id = sockaddr
239
240                                 # Only use the global scope.
241                                 if not scope_id == 0:
242                                         continue
243
244                         # IPv4
245                         elif family == socket.AF_INET:
246                                 address, port = sockaddr
247
248                         # Ignore everything else...
249                         else:
250                                 continue
251
252                         # Add to repsonse list if not already in there.
253                         if not address in addresses:
254                                 addresses.append(address)
255
256                 return addresses