Simplify getting local IP address code.
[oddments/ddns.git] / src / ddns / system.py
CommitLineData
f22ab085 1#!/usr/bin/python
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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###############################################################################
f22ab085 21
d4c5c0d5 22import base64
f22ab085 23import re
6cecd141 24import socket
adb124d0 25import urllib
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26import urllib2
27
28from __version__ import CLIENT_VERSION
7a909224 29from .errors import *
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30from i18n import _
31
32# Initialize the logger.
33import logging
34logger = logging.getLogger("ddns.system")
35logger.propagate = 1
36
37class 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
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50 # Address cache.
51 self.__addresses = {}
52
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53 # Find out on which distribution we are running.
54 self.distro = self._get_distro_identifier()
55 logger.debug(_("Running on distribution: %s") % self.distro)
56
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57 @property
58 def proxy(self):
59 proxy = self.core.settings.get("proxy")
60
61 # Strip http:// at the beginning.
fd898828 62 if proxy and proxy.startswith("http://"):
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63 proxy = proxy[7:]
64
65 return proxy
66
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67 def get_local_ip_address(self, proto):
68 # Legacy code for IPFire 2.
69 if self.distro == "ipfire-2" and proto == "ipv4":
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70 try:
71 with open("/var/ipfire/red/local-ipaddress") as f:
72 return f.readline()
73
74 except IOError, e:
75 # File not found
76 if e.errno == 2:
77 return
78
79 raise
80
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81 # XXX TODO
82 raise NotImplementedError
7f75b957 83
46c23a71 84 def _guess_external_ip_address(self, url, timeout=10):
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85 """
86 Sends a request to an external web server
87 to determine the current default IP address.
88 """
7a909224 89 try:
46c23a71 90 response = self.send_request(url, timeout=timeout)
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91
92 # If the server could not be reached, we will return nothing.
93 except DDNSNetworkError:
94 return
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95
96 if not response.code == 200:
97 return
98
99 match = re.search(r"^Your IP address is: (.*)$", response.read())
100 if match is None:
101 return
102
103 return match.group(1)
104
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105 def guess_external_ip_address(self, family, **kwargs):
106 if family == "ipv6":
107 url = "http://checkip6.dns.lightningwirelabs.com"
108 elif family == "ipv4":
109 url = "http://checkip4.dns.lightningwirelabs.com"
110 else:
111 raise ValueError("unknown address family")
f22ab085 112
022003bc 113 return self._guess_external_ip_address(url, **kwargs)
f22ab085 114
d4c5c0d5 115 def send_request(self, url, method="GET", data=None, username=None, password=None, timeout=30):
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116 assert method in ("GET", "POST")
117
118 # Add all arguments in the data dict to the URL and escape them properly.
119 if method == "GET" and data:
120 query_args = self._format_query_args(data)
121 data = None
122
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123 if "?" in url:
124 url = "%s&%s" % (url, query_args)
125 else:
126 url = "%s?%s" % (url, query_args)
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127
128 logger.debug("Sending request (%s): %s" % (method, url))
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129 if data:
130 logger.debug(" data: %s" % data)
131
132 req = urllib2.Request(url, data=data)
133
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134 if username and password:
135 basic_auth_header = self._make_basic_auth_header(username, password)
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136 req.add_header("Authorization", "Basic %s" % basic_auth_header)
137
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138 # Set the user agent.
139 req.add_header("User-Agent", self.USER_AGENT)
140
141 # All requests should not be cached anywhere.
142 req.add_header("Pragma", "no-cache")
143
144 # Set the upstream proxy if needed.
145 if self.proxy:
146 logger.debug("Using proxy: %s" % self.proxy)
147
148 # Configure the proxy for this request.
149 req.set_proxy(self.proxy, "http")
150
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151 assert req.get_method() == method
152
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153 logger.debug(_("Request header:"))
154 for k, v in req.headers.items():
155 logger.debug(" %s: %s" % (k, v))
156
157 try:
7a909224 158 resp = urllib2.urlopen(req, timeout=timeout)
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159
160 # Log response header.
09c496c5 161 logger.debug(_("Response header (Status Code %s):") % resp.code)
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162 for k, v in resp.info().items():
163 logger.debug(" %s: %s" % (k, v))
164
165 # Return the entire response object.
166 return resp
167
7a909224 168 except urllib2.HTTPError, e:
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169 # 400 - Bad request
170 if e.code == 400:
171 raise DDNSRequestError(e.reason)
172
173 # 401 - Authorization Required
174 # 403 - Forbidden
175 elif e.code in (401, 403):
176 raise DDNSAuthenticationError(e.reason)
177
178 # 500 - Internal Server Error
179 elif e.code == 500:
180 raise DDNSInternalServerError(e.reason)
181
7a909224 182 # 503 - Service Unavailable
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183 elif e.code == 503:
184 raise DDNSServiceUnavailableError(e.reason)
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185
186 # Raise all other unhandled exceptions.
187 raise
188
f22ab085 189 except urllib2.URLError, e:
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190 if e.reason:
191 # Network Unreachable (e.g. no IPv6 access)
192 if e.reason.errno == 101:
193 raise DDNSNetworkUnreachableError
194 elif e.reason.errno == 111:
195 raise DDNSConnectionRefusedError
196
197 # Raise all other unhandled exceptions.
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198 raise
199
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200 except socket.timeout, e:
201 logger.debug(_("Connection timeout"))
202
203 raise DDNSConnectionTimeoutError
204
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205 def _format_query_args(self, data):
206 args = []
207
208 for k, v in data.items():
209 arg = "%s=%s" % (k, urllib.quote(v))
210 args.append(arg)
211
212 return "&".join(args)
213
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214 def _make_basic_auth_header(self, username, password):
215 authstring = "%s:%s" % (username, password)
216
217 # Encode authorization data in base64.
218 authstring = base64.encodestring(authstring)
219
220 # Remove any newline characters.
221 authstring = authstring.replace("\n", "")
222
223 return authstring
224
f22ab085 225 def get_address(self, proto):
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226 """
227 Returns the current IP address for
228 the given IP protocol.
229 """
230 try:
231 return self.__addresses[proto]
232
233 # IP is currently unknown and needs to be retrieved.
234 except KeyError:
235 self.__addresses[proto] = address = \
236 self._get_address(proto)
237
238 return address
239
240 def _get_address(self, proto):
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241 assert proto in ("ipv6", "ipv4")
242
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243 # IPFire 2 does not support IPv6.
244 if self.distro == "ipfire-2" and proto == "ipv6":
245 return
246
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247 # Check if the external IP address should be guessed from
248 # a remote server.
249 guess_ip = self.core.settings.get("guess_external_ip", "true")
250
251 # If the external IP address should be used, we just do
252 # that.
253 if guess_ip in ("true", "yes", "1"):
022003bc 254 return self.guess_external_ip_address(proto)
f22ab085 255
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256 # Get the local IP addresses.
257 else:
eba7100b 258 return self.get_local_ip_address(proto)
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259
260 def resolve(self, hostname, proto=None):
261 addresses = []
262
263 if proto is None:
264 family = 0
265 elif proto == "ipv6":
266 family = socket.AF_INET6
267 elif proto == "ipv4":
268 family = socket.AF_INET
269 else:
270 raise ValueError("Protocol not supported: %s" % proto)
271
272 # Resolve the host address.
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273 try:
274 response = socket.getaddrinfo(hostname, None, family)
275 except socket.gaierror, e:
276 # Name or service not known
277 if e.errno == -2:
278 return []
279
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280 # No record for requested family available (e.g. no AAAA)
281 elif e.errno == -5:
282 return []
283
73f2bc0b 284 raise
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285
286 # Handle responses.
287 for family, socktype, proto, canonname, sockaddr in response:
288 # IPv6
289 if family == socket.AF_INET6:
290 address, port, flow_info, scope_id = sockaddr
291
292 # Only use the global scope.
293 if not scope_id == 0:
294 continue
295
296 # IPv4
297 elif family == socket.AF_INET:
298 address, port = sockaddr
299
300 # Ignore everything else...
301 else:
302 continue
303
304 # Add to repsonse list if not already in there.
305 if not address in addresses:
306 addresses.append(address)
307
308 return addresses
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309
310 def _get_distro_identifier(self):
311 """
312 Returns a unique identifier for the distribution
313 we are running on.
314 """
315 os_release = self.__parse_os_release()
316 if os_release:
317 return os_release
318
319 system_release = self.__parse_system_release()
320 if system_release:
321 return system_release
322
323 # If nothing else could be found, we return
324 # just "unknown".
325 return "unknown"
326
327 def __parse_os_release(self):
328 """
329 Tries to parse /etc/os-release and
330 returns a unique distribution identifier
331 if the file exists.
332 """
333 try:
334 f = open("/etc/os-release", "r")
335 except IOError, e:
336 # File not found
337 if e.errno == 2:
338 return
339
340 raise
341
342 os_release = {}
343 with f:
344 for line in f.readlines():
345 m = re.match(r"^([A-Z\_]+)=(.*)$", line)
346 if m is None:
347 continue
348
349 os_release[m.group(1)] = m.group(2)
350
351 try:
352 return "%(ID)s-%(VERSION_ID)s" % os_release
353 except KeyError:
354 return
355
356 def __parse_system_release(self):
357 """
358 Tries to parse /etc/system-release and
359 returns a unique distribution identifier
360 if the file exists.
361 """
362 try:
363 f = open("/etc/system-release", "r")
364 except IOError, e:
365 # File not found
366 if e.errno == 2:
367 return
368
369 raise
370
371 with f:
372 # Read first line
373 line = f.readline()
374
375 # Check for IPFire systems
376 m = re.match(r"^IPFire (\d).(\d+)", line)
377 if m:
378 return "ipfire-%s" % m.group(1)