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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 | # Address cache. | |
51 | self.__addresses = {} | |
52 | ||
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 | ||
57 | @property | |
58 | def proxy(self): | |
59 | proxy = self.core.settings.get("proxy") | |
60 | ||
61 | # Strip http:// at the beginning. | |
62 | if proxy and proxy.startswith("http://"): | |
63 | proxy = proxy[7:] | |
64 | ||
65 | return proxy | |
66 | ||
67 | def get_local_ip_address(self, proto): | |
68 | # Legacy code for IPFire 2. | |
69 | if self.distro == "ipfire-2" and proto == "ipv4": | |
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 | ||
81 | # XXX TODO | |
82 | raise NotImplementedError | |
83 | ||
84 | def _guess_external_ip_address(self, url, timeout=10): | |
85 | """ | |
86 | Sends a request to an external web server | |
87 | to determine the current default IP address. | |
88 | """ | |
89 | try: | |
90 | response = self.send_request(url, timeout=timeout) | |
91 | ||
92 | # If the server could not be reached, we will return nothing. | |
93 | except DDNSNetworkError: | |
94 | return | |
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 | ||
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") | |
112 | ||
113 | return self._guess_external_ip_address(url, **kwargs) | |
114 | ||
115 | def send_request(self, url, method="GET", data=None, username=None, password=None, timeout=30): | |
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 | ||
123 | if "?" in url: | |
124 | url = "%s&%s" % (url, query_args) | |
125 | else: | |
126 | url = "%s?%s" % (url, query_args) | |
127 | ||
128 | logger.debug("Sending request (%s): %s" % (method, url)) | |
129 | if data: | |
130 | logger.debug(" data: %s" % data) | |
131 | ||
132 | req = urllib2.Request(url, data=data) | |
133 | ||
134 | if username and password: | |
135 | basic_auth_header = self._make_basic_auth_header(username, password) | |
136 | req.add_header("Authorization", "Basic %s" % basic_auth_header) | |
137 | ||
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 | ||
151 | assert req.get_method() == method | |
152 | ||
153 | logger.debug(_("Request header:")) | |
154 | for k, v in req.headers.items(): | |
155 | logger.debug(" %s: %s" % (k, v)) | |
156 | ||
157 | try: | |
158 | resp = urllib2.urlopen(req, timeout=timeout) | |
159 | ||
160 | # Log response header. | |
161 | logger.debug(_("Response header (Status Code %s):") % resp.code) | |
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 | ||
168 | except urllib2.HTTPError, e: | |
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 | ||
182 | # 503 - Service Unavailable | |
183 | elif e.code == 503: | |
184 | raise DDNSServiceUnavailableError(e.reason) | |
185 | ||
186 | # Raise all other unhandled exceptions. | |
187 | raise | |
188 | ||
189 | except urllib2.URLError, e: | |
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. | |
198 | raise | |
199 | ||
200 | except socket.timeout, e: | |
201 | logger.debug(_("Connection timeout")) | |
202 | ||
203 | raise DDNSConnectionTimeoutError | |
204 | ||
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 | ||
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 | ||
225 | def get_address(self, proto): | |
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): | |
241 | assert proto in ("ipv6", "ipv4") | |
242 | ||
243 | # IPFire 2 does not support IPv6. | |
244 | if self.distro == "ipfire-2" and proto == "ipv6": | |
245 | return | |
246 | ||
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"): | |
254 | return self.guess_external_ip_address(proto) | |
255 | ||
256 | # Get the local IP addresses. | |
257 | else: | |
258 | return self.get_local_ip_address(proto) | |
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. | |
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 | ||
280 | # No record for requested family available (e.g. no AAAA) | |
281 | elif e.errno == -5: | |
282 | return [] | |
283 | ||
284 | raise | |
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 | |
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) |