]> git.ipfire.org Git - ddns.git/blob - src/ddns/system.py
Update automatic registration to work with Python 3
[ddns.git] / src / ddns / system.py
1 #!/usr/bin/python3
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 ssl
25 import socket
26 import urllib.request
27 import urllib.parse
28 import urllib.error
29
30 from .__version__ import CLIENT_VERSION
31 from .errors import *
32 from .i18n import _
33
34 # Initialize the logger.
35 import logging
36 logger = logging.getLogger("ddns.system")
37 logger.propagate = 1
38
39 class DDNSSystem(object):
40 """
41 The DDNSSystem class adds a layer of abstraction
42 between the ddns software and the system.
43 """
44
45 # The default useragent.
46 USER_AGENT = "IPFireDDNSUpdater/%s" % CLIENT_VERSION
47
48 def __init__(self, core):
49 # Connection to the core of the program.
50 self.core = core
51
52 # Address cache.
53 self.__addresses = {}
54
55 # Find out on which distribution we are running.
56 self.distro = self._get_distro_identifier()
57 logger.debug(_("Running on distribution: %s") % self.distro)
58
59 @property
60 def proxy(self):
61 proxy = self.core.settings.get("proxy")
62
63 # Strip http:// at the beginning.
64 if proxy and proxy.startswith("http://"):
65 proxy = proxy[7:]
66
67 return proxy
68
69 def get_local_ip_address(self, proto):
70 ip_address = self._get_local_ip_address(proto)
71
72 # Check if the IP address is usable and only return it then
73 if self._is_usable_ip_address(proto, ip_address):
74 return ip_address
75
76 def _get_local_ip_address(self, proto):
77 # Legacy code for IPFire 2.
78 if self.distro == "ipfire-2" and proto == "ipv4":
79 try:
80 with open("/var/ipfire/red/local-ipaddress") as f:
81 return f.readline()
82
83 except IOError as e:
84 # File not found
85 if e.errno == 2:
86 return
87
88 raise
89
90 # XXX TODO
91 raise NotImplementedError
92
93 def _guess_external_ip_address(self, url, timeout=10):
94 """
95 Sends a request to an external web server
96 to determine the current default IP address.
97 """
98 try:
99 response = self.send_request(url, timeout=timeout)
100
101 # If the server could not be reached, we will return nothing.
102 except DDNSNetworkError:
103 return
104
105 if not response.code == 200:
106 return
107
108 match = re.search(r"^Your IP address is: (.*)$", response.read())
109 if match is None:
110 return
111
112 return match.group(1)
113
114 def guess_external_ip_address(self, family, **kwargs):
115 if family == "ipv6":
116 url = "https://checkip6.dns.lightningwirelabs.com"
117 elif family == "ipv4":
118 url = "https://checkip4.dns.lightningwirelabs.com"
119 else:
120 raise ValueError("unknown address family")
121
122 return self._guess_external_ip_address(url, **kwargs)
123
124 def send_request(self, url, method="GET", data=None, username=None, password=None, timeout=30):
125 assert method in ("GET", "POST")
126
127 # Add all arguments in the data dict to the URL and escape them properly.
128 if method == "GET" and data:
129 query_args = self._format_query_args(data)
130 data = None
131
132 if "?" in url:
133 url = "%s&%s" % (url, query_args)
134 else:
135 url = "%s?%s" % (url, query_args)
136
137 logger.debug("Sending request (%s): %s" % (method, url))
138 if data:
139 logger.debug(" data: %s" % data)
140
141 req = urllib.request.Request(url, data=data)
142
143 if username and password:
144 basic_auth_header = self._make_basic_auth_header(username, password)
145 req.add_header("Authorization", "Basic %s" % basic_auth_header)
146
147 # Set the user agent.
148 req.add_header("User-Agent", self.USER_AGENT)
149
150 # All requests should not be cached anywhere.
151 req.add_header("Pragma", "no-cache")
152
153 # Set the upstream proxy if needed.
154 if self.proxy:
155 logger.debug("Using proxy: %s" % self.proxy)
156
157 # Configure the proxy for this request.
158 req.set_proxy(self.proxy, "http")
159
160 assert req.get_method() == method
161
162 logger.debug(_("Request header:"))
163 for k, v in req.headers.items():
164 logger.debug(" %s: %s" % (k, v))
165
166 try:
167 resp = urllib.request.urlopen(req, timeout=timeout)
168
169 # Log response header.
170 logger.debug(_("Response header (Status Code %s):") % resp.code)
171 for k, v in resp.info().items():
172 logger.debug(" %s: %s" % (k, v))
173
174 # Return the entire response object.
175 return resp
176
177 except urllib.error.HTTPError as e:
178 # Log response header.
179 logger.debug(_("Response header (Status Code %s):") % e.code)
180 for k, v in e.hdrs.items():
181 logger.debug(" %s: %s" % (k, v))
182
183 # 400 - Bad request
184 if e.code == 400:
185 raise DDNSRequestError(e.reason)
186
187 # 401 - Authorization Required
188 # 403 - Forbidden
189 elif e.code in (401, 403):
190 raise DDNSAuthenticationError(e.reason)
191
192 # 404 - Not found
193 # Either the provider has changed the API, or
194 # there is an error on the server
195 elif e.code == 404:
196 raise DDNSNotFound(e.reason)
197
198 # 429 - Too Many Requests
199 elif e.code == 429:
200 raise DDNSTooManyRequests(e.reason)
201
202 # 500 - Internal Server Error
203 elif e.code == 500:
204 raise DDNSInternalServerError(e.reason)
205
206 # 503 - Service Unavailable
207 elif e.code == 503:
208 raise DDNSServiceUnavailableError(e.reason)
209
210 # Raise all other unhandled exceptions.
211 raise
212
213 except urllib.error.URLError as e:
214 if e.reason:
215 # Handle SSL errors
216 if isinstance(e.reason, ssl.SSLError):
217 e = e.reason
218
219 if e.reason == "CERTIFICATE_VERIFY_FAILED":
220 raise DDNSCertificateError
221
222 # Raise all other SSL errors
223 raise DDNSSSLError(e.reason)
224
225 # Name or service not known
226 if e.reason.errno == -2:
227 raise DDNSResolveError
228
229 # Network Unreachable (e.g. no IPv6 access)
230 if e.reason.errno == 101:
231 raise DDNSNetworkUnreachableError
232
233 # Connection Refused
234 elif e.reason.errno == 111:
235 raise DDNSConnectionRefusedError
236
237 # No route to host
238 elif e.reason.errno == 113:
239 raise DDNSNoRouteToHostError(req.host)
240
241 # Raise all other unhandled exceptions.
242 raise
243
244 except socket.timeout as e:
245 logger.debug(_("Connection timeout"))
246
247 raise DDNSConnectionTimeoutError
248
249 def _format_query_args(self, data):
250 args = []
251
252 for k, v in data.items():
253 arg = "%s=%s" % (k, urllib.parse.quote(v))
254 args.append(arg)
255
256 return "&".join(args)
257
258 def _make_basic_auth_header(self, username, password):
259 authstring = "%s:%s" % (username, password)
260
261 # Encode authorization data in base64.
262 authstring = base64.encodebytes(authstring)
263
264 # Remove any newline characters.
265 authstring = authstring.replace("\n", "")
266
267 return authstring
268
269 def get_address(self, proto):
270 """
271 Returns the current IP address for
272 the given IP protocol.
273 """
274 try:
275 return self.__addresses[proto]
276
277 # IP is currently unknown and needs to be retrieved.
278 except KeyError:
279 self.__addresses[proto] = address = \
280 self._get_address(proto)
281
282 return address
283
284 def _get_address(self, proto):
285 assert proto in ("ipv6", "ipv4")
286
287 # IPFire 2 does not support IPv6.
288 if self.distro == "ipfire-2" and proto == "ipv6":
289 return
290
291 # Check if the external IP address should be guessed from
292 # a remote server.
293 guess_ip = self.core.settings.get("guess_external_ip", "true")
294 guess_ip = guess_ip in ("true", "yes", "1")
295
296 # Get the local IP address.
297 local_ip_address = None
298
299 if not guess_ip:
300 try:
301 local_ip_address = self.get_local_ip_address(proto)
302 except NotImplementedError:
303 logger.warning(_("Falling back to check the IP address with help of a public server"))
304
305 # If no local IP address could be determined, we will fall back to the guess
306 # it with help of an external server...
307 if not local_ip_address:
308 local_ip_address = self.guess_external_ip_address(proto)
309
310 return local_ip_address
311
312 def _is_usable_ip_address(self, proto, address):
313 """
314 Returns True is the local IP address is usable
315 for dynamic DNS (i.e. is not a RFC1918 address or similar).
316 """
317 if proto == "ipv4":
318 # This is not the most perfect solution to match
319 # these addresses, but instead of pulling in an entire
320 # library to handle the IP addresses better, we match
321 # with regular expressions instead.
322 matches = (
323 # RFC1918 address space
324 r"^10\.\d+\.\d+\.\d+$",
325 r"^192\.168\.\d+\.\d+$",
326 r"^172\.(1[6-9]|2[0-9]|31)\.\d+\.\d+$",
327
328 # Dual Stack Lite address space
329 r"^100\.(6[4-9]|[7-9][0-9]|1[01][0-9]|12[0-7])\.\d+\.\d+$",
330 )
331
332 for match in matches:
333 m = re.match(match, address)
334 if m is None:
335 continue
336
337 # Found a match. IP address is not usable.
338 return False
339
340 # In all other cases, return OK.
341 return True
342
343 def resolve(self, hostname, proto=None):
344 addresses = []
345
346 if proto is None:
347 family = 0
348 elif proto == "ipv6":
349 family = socket.AF_INET6
350 elif proto == "ipv4":
351 family = socket.AF_INET
352 else:
353 raise ValueError("Protocol not supported: %s" % proto)
354
355 # Resolve the host address.
356 try:
357 response = socket.getaddrinfo(hostname, None, family)
358 except socket.gaierror as e:
359 # Name or service not known
360 if e.errno == -2:
361 return []
362
363 # Temporary failure in name resolution
364 elif e.errno == -3:
365 raise DDNSResolveError(hostname)
366
367 # No record for requested family available (e.g. no AAAA)
368 elif e.errno == -5:
369 return []
370
371 raise
372
373 # Handle responses.
374 for family, socktype, proto, canonname, sockaddr in response:
375 # IPv6
376 if family == socket.AF_INET6:
377 address, port, flow_info, scope_id = sockaddr
378
379 # Only use the global scope.
380 if not scope_id == 0:
381 continue
382
383 # IPv4
384 elif family == socket.AF_INET:
385 address, port = sockaddr
386
387 # Ignore everything else...
388 else:
389 continue
390
391 # Add to repsonse list if not already in there.
392 if address not in addresses:
393 addresses.append(address)
394
395 return addresses
396
397 def _get_distro_identifier(self):
398 """
399 Returns a unique identifier for the distribution
400 we are running on.
401 """
402 os_release = self.__parse_os_release()
403 if os_release:
404 return os_release
405
406 system_release = self.__parse_system_release()
407 if system_release:
408 return system_release
409
410 # If nothing else could be found, we return
411 # just "unknown".
412 return "unknown"
413
414 def __parse_os_release(self):
415 """
416 Tries to parse /etc/os-release and
417 returns a unique distribution identifier
418 if the file exists.
419 """
420 try:
421 f = open("/etc/os-release", "r")
422 except IOError as e:
423 # File not found
424 if e.errno == 2:
425 return
426
427 raise
428
429 os_release = {}
430 with f:
431 for line in f.readlines():
432 m = re.match(r"^([A-Z\_]+)=(.*)$", line)
433 if m is None:
434 continue
435
436 os_release[m.group(1)] = m.group(2)
437
438 try:
439 return "%(ID)s-%(VERSION_ID)s" % os_release
440 except KeyError:
441 return
442
443 def __parse_system_release(self):
444 """
445 Tries to parse /etc/system-release and
446 returns a unique distribution identifier
447 if the file exists.
448 """
449 try:
450 f = open("/etc/system-release", "r")
451 except IOError as e:
452 # File not found
453 if e.errno == 2:
454 return
455
456 raise
457
458 with f:
459 # Read first line
460 line = f.readline()
461
462 # Check for IPFire systems
463 m = re.match(r"^IPFire (\d).(\d+)", line)
464 if m:
465 return "ipfire-%s" % m.group(1)