Show More
@@ -1,1888 +1,1892 b'' | |||
|
1 | 1 | from __future__ import absolute_import, print_function |
|
2 | 2 | |
|
3 | 3 | """ Multicast DNS Service Discovery for Python, v0.12 |
|
4 | 4 | Copyright (C) 2003, Paul Scott-Murphy |
|
5 | 5 | |
|
6 | 6 | This module provides a framework for the use of DNS Service Discovery |
|
7 | 7 | using IP multicast. It has been tested against the JRendezvous |
|
8 | 8 | implementation from <a href="http://strangeberry.com">StrangeBerry</a>, |
|
9 | 9 | and against the mDNSResponder from Mac OS X 10.3.8. |
|
10 | 10 | |
|
11 | 11 | This library is free software; you can redistribute it and/or |
|
12 | 12 | modify it under the terms of the GNU Lesser General Public |
|
13 | 13 | License as published by the Free Software Foundation; either |
|
14 | 14 | version 2.1 of the License, or (at your option) any later version. |
|
15 | 15 | |
|
16 | 16 | This library is distributed in the hope that it will be useful, |
|
17 | 17 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
|
18 | 18 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
|
19 | 19 | Lesser General Public License for more details. |
|
20 | 20 | |
|
21 | 21 | You should have received a copy of the GNU Lesser General Public |
|
22 | 22 | License along with this library; if not, see |
|
23 | 23 | <http://www.gnu.org/licenses/>. |
|
24 | 24 | |
|
25 | 25 | """ |
|
26 | 26 | |
|
27 | 27 | """0.12 update - allow selection of binding interface |
|
28 | 28 | typo fix - Thanks A. M. Kuchlingi |
|
29 | 29 | removed all use of word 'Rendezvous' - this is an API change""" |
|
30 | 30 | |
|
31 | 31 | """0.11 update - correction to comments for addListener method |
|
32 | 32 | support for new record types seen from OS X |
|
33 | 33 | - IPv6 address |
|
34 | 34 | - hostinfo |
|
35 | 35 | ignore unknown DNS record types |
|
36 | 36 | fixes to name decoding |
|
37 | 37 | works alongside other processes using port 5353 (e.g. Mac OS X) |
|
38 | 38 | tested against Mac OS X 10.3.2's mDNSResponder |
|
39 | 39 | corrections to removal of list entries for service browser""" |
|
40 | 40 | |
|
41 | 41 | """0.10 update - Jonathon Paisley contributed these corrections: |
|
42 | 42 | always multicast replies, even when query is unicast |
|
43 | 43 | correct a pointer encoding problem |
|
44 | 44 | can now write records in any order |
|
45 | 45 | traceback shown on failure |
|
46 | 46 | better TXT record parsing |
|
47 | 47 | server is now separate from name |
|
48 | 48 | can cancel a service browser |
|
49 | 49 | |
|
50 | 50 | modified some unit tests to accommodate these changes""" |
|
51 | 51 | |
|
52 | 52 | """0.09 update - remove all records on service unregistration |
|
53 | 53 | fix DOS security problem with readName""" |
|
54 | 54 | |
|
55 | 55 | """0.08 update - changed licensing to LGPL""" |
|
56 | 56 | |
|
57 | 57 | """0.07 update - faster shutdown on engine |
|
58 | 58 | pointer encoding of outgoing names |
|
59 | 59 | ServiceBrowser now works |
|
60 | 60 | new unit tests""" |
|
61 | 61 | |
|
62 | 62 | """0.06 update - small improvements with unit tests |
|
63 | 63 | added defined exception types |
|
64 | 64 | new style objects |
|
65 | 65 | fixed hostname/interface problem |
|
66 | 66 | fixed socket timeout problem |
|
67 | 67 | fixed addServiceListener() typo bug |
|
68 | 68 | using select() for socket reads |
|
69 | 69 | tested on Debian unstable with Python 2.2.2""" |
|
70 | 70 | |
|
71 | 71 | """0.05 update - ensure case insensitivity on domain names |
|
72 | 72 | support for unicast DNS queries""" |
|
73 | 73 | |
|
74 | 74 | """0.04 update - added some unit tests |
|
75 | 75 | added __ne__ adjuncts where required |
|
76 | 76 | ensure names end in '.local.' |
|
77 | 77 | timeout on receiving socket for clean shutdown""" |
|
78 | 78 | |
|
79 | 79 | __author__ = b"Paul Scott-Murphy" |
|
80 | 80 | __email__ = b"paul at scott dash murphy dot com" |
|
81 | 81 | __version__ = b"0.12" |
|
82 | 82 | |
|
83 | 83 | import errno |
|
84 | 84 | import itertools |
|
85 | 85 | import select |
|
86 | 86 | import socket |
|
87 | 87 | import struct |
|
88 | 88 | import threading |
|
89 | 89 | import time |
|
90 | 90 | import traceback |
|
91 | 91 | |
|
92 | 92 | from mercurial import pycompat |
|
93 | 93 | |
|
94 | 94 | __all__ = [b"Zeroconf", b"ServiceInfo", b"ServiceBrowser"] |
|
95 | 95 | |
|
96 | 96 | # hook for threads |
|
97 | 97 | |
|
98 | 98 | globals()[b'_GLOBAL_DONE'] = 0 |
|
99 | 99 | |
|
100 | 100 | # Some timing constants |
|
101 | 101 | |
|
102 | 102 | _UNREGISTER_TIME = 125 |
|
103 | 103 | _CHECK_TIME = 175 |
|
104 | 104 | _REGISTER_TIME = 225 |
|
105 | 105 | _LISTENER_TIME = 200 |
|
106 | 106 | _BROWSER_TIME = 500 |
|
107 | 107 | |
|
108 | 108 | # Some DNS constants |
|
109 | 109 | |
|
110 | 110 | _MDNS_ADDR = r'224.0.0.251' |
|
111 | 111 | _MDNS_PORT = 5353 |
|
112 | 112 | _DNS_PORT = 53 |
|
113 | 113 | _DNS_TTL = 60 * 60 # one hour default TTL |
|
114 | 114 | |
|
115 | 115 | _MAX_MSG_TYPICAL = 1460 # unused |
|
116 | 116 | _MAX_MSG_ABSOLUTE = 8972 |
|
117 | 117 | |
|
118 | 118 | _FLAGS_QR_MASK = 0x8000 # query response mask |
|
119 | 119 | _FLAGS_QR_QUERY = 0x0000 # query |
|
120 | 120 | _FLAGS_QR_RESPONSE = 0x8000 # response |
|
121 | 121 | |
|
122 | 122 | _FLAGS_AA = 0x0400 # Authoritative answer |
|
123 | 123 | _FLAGS_TC = 0x0200 # Truncated |
|
124 | 124 | _FLAGS_RD = 0x0100 # Recursion desired |
|
125 | 125 | _FLAGS_RA = 0x8000 # Recursion available |
|
126 | 126 | |
|
127 | 127 | _FLAGS_Z = 0x0040 # Zero |
|
128 | 128 | _FLAGS_AD = 0x0020 # Authentic data |
|
129 | 129 | _FLAGS_CD = 0x0010 # Checking disabled |
|
130 | 130 | |
|
131 | 131 | _CLASS_IN = 1 |
|
132 | 132 | _CLASS_CS = 2 |
|
133 | 133 | _CLASS_CH = 3 |
|
134 | 134 | _CLASS_HS = 4 |
|
135 | 135 | _CLASS_NONE = 254 |
|
136 | 136 | _CLASS_ANY = 255 |
|
137 | 137 | _CLASS_MASK = 0x7FFF |
|
138 | 138 | _CLASS_UNIQUE = 0x8000 |
|
139 | 139 | |
|
140 | 140 | _TYPE_A = 1 |
|
141 | 141 | _TYPE_NS = 2 |
|
142 | 142 | _TYPE_MD = 3 |
|
143 | 143 | _TYPE_MF = 4 |
|
144 | 144 | _TYPE_CNAME = 5 |
|
145 | 145 | _TYPE_SOA = 6 |
|
146 | 146 | _TYPE_MB = 7 |
|
147 | 147 | _TYPE_MG = 8 |
|
148 | 148 | _TYPE_MR = 9 |
|
149 | 149 | _TYPE_NULL = 10 |
|
150 | 150 | _TYPE_WKS = 11 |
|
151 | 151 | _TYPE_PTR = 12 |
|
152 | 152 | _TYPE_HINFO = 13 |
|
153 | 153 | _TYPE_MINFO = 14 |
|
154 | 154 | _TYPE_MX = 15 |
|
155 | 155 | _TYPE_TXT = 16 |
|
156 | 156 | _TYPE_AAAA = 28 |
|
157 | 157 | _TYPE_SRV = 33 |
|
158 | 158 | _TYPE_ANY = 255 |
|
159 | 159 | |
|
160 | 160 | # Mapping constants to names |
|
161 | 161 | |
|
162 | 162 | _CLASSES = { |
|
163 | 163 | _CLASS_IN: b"in", |
|
164 | 164 | _CLASS_CS: b"cs", |
|
165 | 165 | _CLASS_CH: b"ch", |
|
166 | 166 | _CLASS_HS: b"hs", |
|
167 | 167 | _CLASS_NONE: b"none", |
|
168 | 168 | _CLASS_ANY: b"any", |
|
169 | 169 | } |
|
170 | 170 | |
|
171 | 171 | _TYPES = { |
|
172 | 172 | _TYPE_A: b"a", |
|
173 | 173 | _TYPE_NS: b"ns", |
|
174 | 174 | _TYPE_MD: b"md", |
|
175 | 175 | _TYPE_MF: b"mf", |
|
176 | 176 | _TYPE_CNAME: b"cname", |
|
177 | 177 | _TYPE_SOA: b"soa", |
|
178 | 178 | _TYPE_MB: b"mb", |
|
179 | 179 | _TYPE_MG: b"mg", |
|
180 | 180 | _TYPE_MR: b"mr", |
|
181 | 181 | _TYPE_NULL: b"null", |
|
182 | 182 | _TYPE_WKS: b"wks", |
|
183 | 183 | _TYPE_PTR: b"ptr", |
|
184 | 184 | _TYPE_HINFO: b"hinfo", |
|
185 | 185 | _TYPE_MINFO: b"minfo", |
|
186 | 186 | _TYPE_MX: b"mx", |
|
187 | 187 | _TYPE_TXT: b"txt", |
|
188 | 188 | _TYPE_AAAA: b"quada", |
|
189 | 189 | _TYPE_SRV: b"srv", |
|
190 | 190 | _TYPE_ANY: b"any", |
|
191 | 191 | } |
|
192 | 192 | |
|
193 | 193 | # utility functions |
|
194 | 194 | |
|
195 | 195 | |
|
196 | 196 | def currentTimeMillis(): |
|
197 | 197 | """Current system time in milliseconds""" |
|
198 | 198 | return time.time() * 1000 |
|
199 | 199 | |
|
200 | 200 | |
|
201 | 201 | # Exceptions |
|
202 | 202 | |
|
203 | 203 | |
|
204 | 204 | class NonLocalNameException(Exception): |
|
205 | 205 | pass |
|
206 | 206 | |
|
207 | 207 | |
|
208 | 208 | class NonUniqueNameException(Exception): |
|
209 | 209 | pass |
|
210 | 210 | |
|
211 | 211 | |
|
212 | 212 | class NamePartTooLongException(Exception): |
|
213 | 213 | pass |
|
214 | 214 | |
|
215 | 215 | |
|
216 | 216 | class AbstractMethodException(Exception): |
|
217 | 217 | pass |
|
218 | 218 | |
|
219 | 219 | |
|
220 | 220 | class BadTypeInNameException(Exception): |
|
221 | 221 | pass |
|
222 | 222 | |
|
223 | 223 | |
|
224 | 224 | class BadDomainName(Exception): |
|
225 | 225 | def __init__(self, pos): |
|
226 | 226 | Exception.__init__(self, b"at position %s" % pos) |
|
227 | 227 | |
|
228 | 228 | |
|
229 | 229 | class BadDomainNameCircular(BadDomainName): |
|
230 | 230 | pass |
|
231 | 231 | |
|
232 | 232 | |
|
233 | 233 | # implementation classes |
|
234 | 234 | |
|
235 | 235 | |
|
236 | 236 | class DNSEntry(object): |
|
237 | 237 | """A DNS entry""" |
|
238 | 238 | |
|
239 | 239 | def __init__(self, name, type, clazz): |
|
240 | 240 | self.key = name.lower() |
|
241 | 241 | self.name = name |
|
242 | 242 | self.type = type |
|
243 | 243 | self.clazz = clazz & _CLASS_MASK |
|
244 | 244 | self.unique = (clazz & _CLASS_UNIQUE) != 0 |
|
245 | 245 | |
|
246 | 246 | def __eq__(self, other): |
|
247 | 247 | """Equality test on name, type, and class""" |
|
248 | 248 | if isinstance(other, DNSEntry): |
|
249 | 249 | return ( |
|
250 | 250 | self.name == other.name |
|
251 | 251 | and self.type == other.type |
|
252 | 252 | and self.clazz == other.clazz |
|
253 | 253 | ) |
|
254 | 254 | return 0 |
|
255 | 255 | |
|
256 | 256 | def __ne__(self, other): |
|
257 | 257 | """Non-equality test""" |
|
258 | 258 | return not self.__eq__(other) |
|
259 | 259 | |
|
260 | 260 | def getClazz(self, clazz): |
|
261 | 261 | """Class accessor""" |
|
262 | 262 | try: |
|
263 | 263 | return _CLASSES[clazz] |
|
264 | 264 | except KeyError: |
|
265 | 265 | return b"?(%s)" % clazz |
|
266 | 266 | |
|
267 | 267 | def getType(self, type): |
|
268 | 268 | """Type accessor""" |
|
269 | 269 | try: |
|
270 | 270 | return _TYPES[type] |
|
271 | 271 | except KeyError: |
|
272 | 272 | return b"?(%s)" % type |
|
273 | 273 | |
|
274 | 274 | def toString(self, hdr, other): |
|
275 | 275 | """String representation with additional information""" |
|
276 | 276 | result = b"%s[%s,%s" % ( |
|
277 | 277 | hdr, |
|
278 | 278 | self.getType(self.type), |
|
279 | 279 | self.getClazz(self.clazz), |
|
280 | 280 | ) |
|
281 | 281 | if self.unique: |
|
282 | 282 | result += b"-unique," |
|
283 | 283 | else: |
|
284 | 284 | result += b"," |
|
285 | 285 | result += self.name |
|
286 | 286 | if other is not None: |
|
287 | 287 | result += b",%s]" % other |
|
288 | 288 | else: |
|
289 | 289 | result += b"]" |
|
290 | 290 | return result |
|
291 | 291 | |
|
292 | 292 | |
|
293 | 293 | class DNSQuestion(DNSEntry): |
|
294 | 294 | """A DNS question entry""" |
|
295 | 295 | |
|
296 | 296 | def __init__(self, name, type, clazz): |
|
297 | 297 | if pycompat.ispy3 and isinstance(name, str): |
|
298 | 298 | name = name.encode('ascii') |
|
299 | 299 | if not name.endswith(b".local."): |
|
300 | 300 | raise NonLocalNameException(name) |
|
301 | 301 | DNSEntry.__init__(self, name, type, clazz) |
|
302 | 302 | |
|
303 | 303 | def answeredBy(self, rec): |
|
304 | 304 | """Returns true if the question is answered by the record""" |
|
305 | 305 | return ( |
|
306 | 306 | self.clazz == rec.clazz |
|
307 | 307 | and (self.type == rec.type or self.type == _TYPE_ANY) |
|
308 | 308 | and self.name == rec.name |
|
309 | 309 | ) |
|
310 | 310 | |
|
311 | 311 | def __repr__(self): |
|
312 | 312 | """String representation""" |
|
313 | 313 | return DNSEntry.toString(self, b"question", None) |
|
314 | 314 | |
|
315 | 315 | |
|
316 | 316 | class DNSRecord(DNSEntry): |
|
317 | 317 | """A DNS record - like a DNS entry, but has a TTL""" |
|
318 | 318 | |
|
319 | 319 | def __init__(self, name, type, clazz, ttl): |
|
320 | 320 | DNSEntry.__init__(self, name, type, clazz) |
|
321 | 321 | self.ttl = ttl |
|
322 | 322 | self.created = currentTimeMillis() |
|
323 | 323 | |
|
324 | 324 | def __eq__(self, other): |
|
325 | 325 | """Tests equality as per DNSRecord""" |
|
326 | 326 | if isinstance(other, DNSRecord): |
|
327 | 327 | return DNSEntry.__eq__(self, other) |
|
328 | 328 | return 0 |
|
329 | 329 | |
|
330 | 330 | def suppressedBy(self, msg): |
|
331 | 331 | """Returns true if any answer in a message can suffice for the |
|
332 | 332 | information held in this record.""" |
|
333 | 333 | for record in msg.answers: |
|
334 | 334 | if self.suppressedByAnswer(record): |
|
335 | 335 | return 1 |
|
336 | 336 | return 0 |
|
337 | 337 | |
|
338 | 338 | def suppressedByAnswer(self, other): |
|
339 | 339 | """Returns true if another record has same name, type and class, |
|
340 | 340 | and if its TTL is at least half of this record's.""" |
|
341 | 341 | if self == other and other.ttl > (self.ttl / 2): |
|
342 | 342 | return 1 |
|
343 | 343 | return 0 |
|
344 | 344 | |
|
345 | 345 | def getExpirationTime(self, percent): |
|
346 | 346 | """Returns the time at which this record will have expired |
|
347 | 347 | by a certain percentage.""" |
|
348 | 348 | return self.created + (percent * self.ttl * 10) |
|
349 | 349 | |
|
350 | 350 | def getRemainingTTL(self, now): |
|
351 | 351 | """Returns the remaining TTL in seconds.""" |
|
352 | 352 | return max(0, (self.getExpirationTime(100) - now) / 1000) |
|
353 | 353 | |
|
354 | 354 | def isExpired(self, now): |
|
355 | 355 | """Returns true if this record has expired.""" |
|
356 | 356 | return self.getExpirationTime(100) <= now |
|
357 | 357 | |
|
358 | 358 | def isStale(self, now): |
|
359 | 359 | """Returns true if this record is at least half way expired.""" |
|
360 | 360 | return self.getExpirationTime(50) <= now |
|
361 | 361 | |
|
362 | 362 | def resetTTL(self, other): |
|
363 | 363 | """Sets this record's TTL and created time to that of |
|
364 | 364 | another record.""" |
|
365 | 365 | self.created = other.created |
|
366 | 366 | self.ttl = other.ttl |
|
367 | 367 | |
|
368 | 368 | def write(self, out): |
|
369 | 369 | """Abstract method""" |
|
370 | 370 | raise AbstractMethodException |
|
371 | 371 | |
|
372 | 372 | def toString(self, other): |
|
373 | 373 | """String representation with additional information""" |
|
374 | 374 | arg = b"%s/%s,%s" % ( |
|
375 | 375 | self.ttl, |
|
376 | 376 | self.getRemainingTTL(currentTimeMillis()), |
|
377 | 377 | other, |
|
378 | 378 | ) |
|
379 | 379 | return DNSEntry.toString(self, b"record", arg) |
|
380 | 380 | |
|
381 | 381 | |
|
382 | 382 | class DNSAddress(DNSRecord): |
|
383 | 383 | """A DNS address record""" |
|
384 | 384 | |
|
385 | 385 | def __init__(self, name, type, clazz, ttl, address): |
|
386 | 386 | DNSRecord.__init__(self, name, type, clazz, ttl) |
|
387 | 387 | self.address = address |
|
388 | 388 | |
|
389 | 389 | def write(self, out): |
|
390 | 390 | """Used in constructing an outgoing packet""" |
|
391 | 391 | out.writeString(self.address, len(self.address)) |
|
392 | 392 | |
|
393 | 393 | def __eq__(self, other): |
|
394 | 394 | """Tests equality on address""" |
|
395 | 395 | if isinstance(other, DNSAddress): |
|
396 | 396 | return self.address == other.address |
|
397 | 397 | return 0 |
|
398 | 398 | |
|
399 | 399 | def __repr__(self): |
|
400 | 400 | """String representation""" |
|
401 | 401 | try: |
|
402 | 402 | return socket.inet_ntoa(self.address) |
|
403 | 403 | except Exception: |
|
404 | 404 | return self.address |
|
405 | 405 | |
|
406 | 406 | |
|
407 | 407 | class DNSHinfo(DNSRecord): |
|
408 | 408 | """A DNS host information record""" |
|
409 | 409 | |
|
410 | 410 | def __init__(self, name, type, clazz, ttl, cpu, os): |
|
411 | 411 | DNSRecord.__init__(self, name, type, clazz, ttl) |
|
412 | 412 | self.cpu = cpu |
|
413 | 413 | self.os = os |
|
414 | 414 | |
|
415 | 415 | def write(self, out): |
|
416 | 416 | """Used in constructing an outgoing packet""" |
|
417 | 417 | out.writeString(self.cpu, len(self.cpu)) |
|
418 | 418 | out.writeString(self.os, len(self.os)) |
|
419 | 419 | |
|
420 | 420 | def __eq__(self, other): |
|
421 | 421 | """Tests equality on cpu and os""" |
|
422 | 422 | if isinstance(other, DNSHinfo): |
|
423 | 423 | return self.cpu == other.cpu and self.os == other.os |
|
424 | 424 | return 0 |
|
425 | 425 | |
|
426 | 426 | def __repr__(self): |
|
427 | 427 | """String representation""" |
|
428 | 428 | return self.cpu + b" " + self.os |
|
429 | 429 | |
|
430 | 430 | |
|
431 | 431 | class DNSPointer(DNSRecord): |
|
432 | 432 | """A DNS pointer record""" |
|
433 | 433 | |
|
434 | 434 | def __init__(self, name, type, clazz, ttl, alias): |
|
435 | 435 | DNSRecord.__init__(self, name, type, clazz, ttl) |
|
436 | 436 | self.alias = alias |
|
437 | 437 | |
|
438 | 438 | def write(self, out): |
|
439 | 439 | """Used in constructing an outgoing packet""" |
|
440 | 440 | out.writeName(self.alias) |
|
441 | 441 | |
|
442 | 442 | def __eq__(self, other): |
|
443 | 443 | """Tests equality on alias""" |
|
444 | 444 | if isinstance(other, DNSPointer): |
|
445 | 445 | return self.alias == other.alias |
|
446 | 446 | return 0 |
|
447 | 447 | |
|
448 | 448 | def __repr__(self): |
|
449 | 449 | """String representation""" |
|
450 | 450 | return self.toString(self.alias) |
|
451 | 451 | |
|
452 | 452 | |
|
453 | 453 | class DNSText(DNSRecord): |
|
454 | 454 | """A DNS text record""" |
|
455 | 455 | |
|
456 | 456 | def __init__(self, name, type, clazz, ttl, text): |
|
457 | 457 | DNSRecord.__init__(self, name, type, clazz, ttl) |
|
458 | 458 | self.text = text |
|
459 | 459 | |
|
460 | 460 | def write(self, out): |
|
461 | 461 | """Used in constructing an outgoing packet""" |
|
462 | 462 | out.writeString(self.text, len(self.text)) |
|
463 | 463 | |
|
464 | 464 | def __eq__(self, other): |
|
465 | 465 | """Tests equality on text""" |
|
466 | 466 | if isinstance(other, DNSText): |
|
467 | 467 | return self.text == other.text |
|
468 | 468 | return 0 |
|
469 | 469 | |
|
470 | 470 | def __repr__(self): |
|
471 | 471 | """String representation""" |
|
472 | 472 | if len(self.text) > 10: |
|
473 | 473 | return self.toString(self.text[:7] + b"...") |
|
474 | 474 | else: |
|
475 | 475 | return self.toString(self.text) |
|
476 | 476 | |
|
477 | 477 | |
|
478 | 478 | class DNSService(DNSRecord): |
|
479 | 479 | """A DNS service record""" |
|
480 | 480 | |
|
481 | 481 | def __init__(self, name, type, clazz, ttl, priority, weight, port, server): |
|
482 | 482 | DNSRecord.__init__(self, name, type, clazz, ttl) |
|
483 | 483 | self.priority = priority |
|
484 | 484 | self.weight = weight |
|
485 | 485 | self.port = port |
|
486 | 486 | self.server = server |
|
487 | 487 | |
|
488 | 488 | def write(self, out): |
|
489 | 489 | """Used in constructing an outgoing packet""" |
|
490 | 490 | out.writeShort(self.priority) |
|
491 | 491 | out.writeShort(self.weight) |
|
492 | 492 | out.writeShort(self.port) |
|
493 | 493 | out.writeName(self.server) |
|
494 | 494 | |
|
495 | 495 | def __eq__(self, other): |
|
496 | 496 | """Tests equality on priority, weight, port and server""" |
|
497 | 497 | if isinstance(other, DNSService): |
|
498 | 498 | return ( |
|
499 | 499 | self.priority == other.priority |
|
500 | 500 | and self.weight == other.weight |
|
501 | 501 | and self.port == other.port |
|
502 | 502 | and self.server == other.server |
|
503 | 503 | ) |
|
504 | 504 | return 0 |
|
505 | 505 | |
|
506 | 506 | def __repr__(self): |
|
507 | 507 | """String representation""" |
|
508 | 508 | return self.toString(b"%s:%s" % (self.server, self.port)) |
|
509 | 509 | |
|
510 | 510 | |
|
511 | 511 | class DNSIncoming(object): |
|
512 | 512 | """Object representation of an incoming DNS packet""" |
|
513 | 513 | |
|
514 | 514 | def __init__(self, data): |
|
515 | 515 | """Constructor from string holding bytes of packet""" |
|
516 | 516 | self.offset = 0 |
|
517 | 517 | self.data = data |
|
518 | 518 | self.questions = [] |
|
519 | 519 | self.answers = [] |
|
520 | 520 | self.numquestions = 0 |
|
521 | 521 | self.numanswers = 0 |
|
522 | 522 | self.numauthorities = 0 |
|
523 | 523 | self.numadditionals = 0 |
|
524 | 524 | |
|
525 | 525 | self.readHeader() |
|
526 | 526 | self.readQuestions() |
|
527 | 527 | self.readOthers() |
|
528 | 528 | |
|
529 | 529 | def readHeader(self): |
|
530 | 530 | """Reads header portion of packet""" |
|
531 | 531 | format = b'!HHHHHH' |
|
532 | 532 | length = struct.calcsize(format) |
|
533 | 533 | info = struct.unpack( |
|
534 | 534 | format, self.data[self.offset : self.offset + length] |
|
535 | 535 | ) |
|
536 | 536 | self.offset += length |
|
537 | 537 | |
|
538 | 538 | self.id = info[0] |
|
539 | 539 | self.flags = info[1] |
|
540 | 540 | self.numquestions = info[2] |
|
541 | 541 | self.numanswers = info[3] |
|
542 | 542 | self.numauthorities = info[4] |
|
543 | 543 | self.numadditionals = info[5] |
|
544 | 544 | |
|
545 | 545 | def readQuestions(self): |
|
546 | 546 | """Reads questions section of packet""" |
|
547 | 547 | format = b'!HH' |
|
548 | 548 | length = struct.calcsize(format) |
|
549 | 549 | for i in range(0, self.numquestions): |
|
550 | 550 | name = self.readName() |
|
551 | 551 | info = struct.unpack( |
|
552 | 552 | format, self.data[self.offset : self.offset + length] |
|
553 | 553 | ) |
|
554 | 554 | self.offset += length |
|
555 | 555 | |
|
556 | 556 | try: |
|
557 | 557 | question = DNSQuestion(name, info[0], info[1]) |
|
558 | 558 | self.questions.append(question) |
|
559 | 559 | except NonLocalNameException: |
|
560 | 560 | pass |
|
561 | 561 | |
|
562 | 562 | def readInt(self): |
|
563 | 563 | """Reads an integer from the packet""" |
|
564 | 564 | format = b'!I' |
|
565 | 565 | length = struct.calcsize(format) |
|
566 | 566 | info = struct.unpack( |
|
567 | 567 | format, self.data[self.offset : self.offset + length] |
|
568 | 568 | ) |
|
569 | 569 | self.offset += length |
|
570 | 570 | return info[0] |
|
571 | 571 | |
|
572 | 572 | def readCharacterString(self): |
|
573 | 573 | """Reads a character string from the packet""" |
|
574 | 574 | length = ord(self.data[self.offset]) |
|
575 | 575 | self.offset += 1 |
|
576 | 576 | return self.readString(length) |
|
577 | 577 | |
|
578 | 578 | def readString(self, len): |
|
579 | 579 | """Reads a string of a given length from the packet""" |
|
580 | 580 | format = b'!%ds' % len |
|
581 | 581 | length = struct.calcsize(format) |
|
582 | 582 | info = struct.unpack( |
|
583 | 583 | format, self.data[self.offset : self.offset + length] |
|
584 | 584 | ) |
|
585 | 585 | self.offset += length |
|
586 | 586 | return info[0] |
|
587 | 587 | |
|
588 | 588 | def readUnsignedShort(self): |
|
589 | 589 | """Reads an unsigned short from the packet""" |
|
590 | 590 | format = b'!H' |
|
591 | 591 | length = struct.calcsize(format) |
|
592 | 592 | info = struct.unpack( |
|
593 | 593 | format, self.data[self.offset : self.offset + length] |
|
594 | 594 | ) |
|
595 | 595 | self.offset += length |
|
596 | 596 | return info[0] |
|
597 | 597 | |
|
598 | 598 | def readOthers(self): |
|
599 | 599 | """Reads answers, authorities and additionals section of the packet""" |
|
600 | 600 | format = b'!HHiH' |
|
601 | 601 | length = struct.calcsize(format) |
|
602 | 602 | n = self.numanswers + self.numauthorities + self.numadditionals |
|
603 | 603 | for i in range(0, n): |
|
604 | 604 | domain = self.readName() |
|
605 | 605 | info = struct.unpack( |
|
606 | 606 | format, self.data[self.offset : self.offset + length] |
|
607 | 607 | ) |
|
608 | 608 | self.offset += length |
|
609 | 609 | |
|
610 | 610 | rec = None |
|
611 | 611 | if info[0] == _TYPE_A: |
|
612 | 612 | rec = DNSAddress( |
|
613 | 613 | domain, info[0], info[1], info[2], self.readString(4) |
|
614 | 614 | ) |
|
615 | 615 | elif info[0] == _TYPE_CNAME or info[0] == _TYPE_PTR: |
|
616 | 616 | rec = DNSPointer( |
|
617 | 617 | domain, info[0], info[1], info[2], self.readName() |
|
618 | 618 | ) |
|
619 | 619 | elif info[0] == _TYPE_TXT: |
|
620 | 620 | rec = DNSText( |
|
621 | 621 | domain, info[0], info[1], info[2], self.readString(info[3]) |
|
622 | 622 | ) |
|
623 | 623 | elif info[0] == _TYPE_SRV: |
|
624 | 624 | rec = DNSService( |
|
625 | 625 | domain, |
|
626 | 626 | info[0], |
|
627 | 627 | info[1], |
|
628 | 628 | info[2], |
|
629 | 629 | self.readUnsignedShort(), |
|
630 | 630 | self.readUnsignedShort(), |
|
631 | 631 | self.readUnsignedShort(), |
|
632 | 632 | self.readName(), |
|
633 | 633 | ) |
|
634 | 634 | elif info[0] == _TYPE_HINFO: |
|
635 | 635 | rec = DNSHinfo( |
|
636 | 636 | domain, |
|
637 | 637 | info[0], |
|
638 | 638 | info[1], |
|
639 | 639 | info[2], |
|
640 | 640 | self.readCharacterString(), |
|
641 | 641 | self.readCharacterString(), |
|
642 | 642 | ) |
|
643 | 643 | elif info[0] == _TYPE_AAAA: |
|
644 | 644 | rec = DNSAddress( |
|
645 | 645 | domain, info[0], info[1], info[2], self.readString(16) |
|
646 | 646 | ) |
|
647 | 647 | else: |
|
648 | 648 | # Try to ignore types we don't know about |
|
649 | 649 | # this may mean the rest of the name is |
|
650 | 650 | # unable to be parsed, and may show errors |
|
651 | 651 | # so this is left for debugging. New types |
|
652 | 652 | # encountered need to be parsed properly. |
|
653 | 653 | # |
|
654 | 654 | # print "UNKNOWN TYPE = " + str(info[0]) |
|
655 | 655 | # raise BadTypeInNameException |
|
656 | 656 | self.offset += info[3] |
|
657 | 657 | |
|
658 | 658 | if rec is not None: |
|
659 | 659 | self.answers.append(rec) |
|
660 | 660 | |
|
661 | 661 | def isQuery(self): |
|
662 | 662 | """Returns true if this is a query""" |
|
663 | 663 | return (self.flags & _FLAGS_QR_MASK) == _FLAGS_QR_QUERY |
|
664 | 664 | |
|
665 | 665 | def isResponse(self): |
|
666 | 666 | """Returns true if this is a response""" |
|
667 | 667 | return (self.flags & _FLAGS_QR_MASK) == _FLAGS_QR_RESPONSE |
|
668 | 668 | |
|
669 | 669 | def readUTF(self, offset, len): |
|
670 | 670 | """Reads a UTF-8 string of a given length from the packet""" |
|
671 | 671 | return self.data[offset : offset + len].decode('utf-8') |
|
672 | 672 | |
|
673 | 673 | def readName(self): |
|
674 | 674 | """Reads a domain name from the packet""" |
|
675 | 675 | result = r'' |
|
676 | 676 | off = self.offset |
|
677 | 677 | next = -1 |
|
678 | 678 | first = off |
|
679 | 679 | |
|
680 | 680 | while True: |
|
681 | 681 | len = ord(self.data[off : off + 1]) |
|
682 | 682 | off += 1 |
|
683 | 683 | if len == 0: |
|
684 | 684 | break |
|
685 | 685 | t = len & 0xC0 |
|
686 | 686 | if t == 0x00: |
|
687 | 687 | result = r''.join((result, self.readUTF(off, len) + r'.')) |
|
688 | 688 | off += len |
|
689 | 689 | elif t == 0xC0: |
|
690 | 690 | if next < 0: |
|
691 | 691 | next = off + 1 |
|
692 | 692 | off = ((len & 0x3F) << 8) | ord(self.data[off : off + 1]) |
|
693 | 693 | if off >= first: |
|
694 | 694 | raise BadDomainNameCircular(off) |
|
695 | 695 | first = off |
|
696 | 696 | else: |
|
697 | 697 | raise BadDomainName(off) |
|
698 | 698 | |
|
699 | 699 | if next >= 0: |
|
700 | 700 | self.offset = next |
|
701 | 701 | else: |
|
702 | 702 | self.offset = off |
|
703 | 703 | |
|
704 | 704 | return result |
|
705 | 705 | |
|
706 | 706 | |
|
707 | 707 | class DNSOutgoing(object): |
|
708 | 708 | """Object representation of an outgoing packet""" |
|
709 | 709 | |
|
710 | 710 | def __init__(self, flags, multicast=1): |
|
711 | 711 | self.finished = 0 |
|
712 | 712 | self.id = 0 |
|
713 | 713 | self.multicast = multicast |
|
714 | 714 | self.flags = flags |
|
715 | 715 | self.names = {} |
|
716 | 716 | self.data = [] |
|
717 | 717 | self.size = 12 |
|
718 | 718 | |
|
719 | 719 | self.questions = [] |
|
720 | 720 | self.answers = [] |
|
721 | 721 | self.authorities = [] |
|
722 | 722 | self.additionals = [] |
|
723 | 723 | |
|
724 | 724 | def addQuestion(self, record): |
|
725 | 725 | """Adds a question""" |
|
726 | 726 | self.questions.append(record) |
|
727 | 727 | |
|
728 | 728 | def addAnswer(self, inp, record): |
|
729 | 729 | """Adds an answer""" |
|
730 | 730 | if not record.suppressedBy(inp): |
|
731 | 731 | self.addAnswerAtTime(record, 0) |
|
732 | 732 | |
|
733 | 733 | def addAnswerAtTime(self, record, now): |
|
734 | 734 | """Adds an answer if if does not expire by a certain time""" |
|
735 | 735 | if record is not None: |
|
736 | 736 | if now == 0 or not record.isExpired(now): |
|
737 | 737 | self.answers.append((record, now)) |
|
738 | 738 | |
|
739 | 739 | def addAuthoritativeAnswer(self, record): |
|
740 | 740 | """Adds an authoritative answer""" |
|
741 | 741 | self.authorities.append(record) |
|
742 | 742 | |
|
743 | 743 | def addAdditionalAnswer(self, record): |
|
744 | 744 | """Adds an additional answer""" |
|
745 | 745 | self.additionals.append(record) |
|
746 | 746 | |
|
747 | 747 | def writeByte(self, value): |
|
748 | 748 | """Writes a single byte to the packet""" |
|
749 | 749 | format = b'!c' |
|
750 | 750 | self.data.append(struct.pack(format, chr(value))) |
|
751 | 751 | self.size += 1 |
|
752 | 752 | |
|
753 | 753 | def insertShort(self, index, value): |
|
754 | 754 | """Inserts an unsigned short in a certain position in the packet""" |
|
755 | 755 | format = b'!H' |
|
756 | 756 | self.data.insert(index, struct.pack(format, value)) |
|
757 | 757 | self.size += 2 |
|
758 | 758 | |
|
759 | 759 | def writeShort(self, value): |
|
760 | 760 | """Writes an unsigned short to the packet""" |
|
761 | 761 | format = b'!H' |
|
762 | 762 | self.data.append(struct.pack(format, value)) |
|
763 | 763 | self.size += 2 |
|
764 | 764 | |
|
765 | 765 | def writeInt(self, value): |
|
766 | 766 | """Writes an unsigned integer to the packet""" |
|
767 | 767 | format = b'!I' |
|
768 | 768 | self.data.append(struct.pack(format, int(value))) |
|
769 | 769 | self.size += 4 |
|
770 | 770 | |
|
771 | 771 | def writeString(self, value, length): |
|
772 | 772 | """Writes a string to the packet""" |
|
773 | 773 | format = b'!' + str(length) + b's' |
|
774 | 774 | self.data.append(struct.pack(format, value)) |
|
775 | 775 | self.size += length |
|
776 | 776 | |
|
777 | 777 | def writeUTF(self, s): |
|
778 | 778 | """Writes a UTF-8 string of a given length to the packet""" |
|
779 | 779 | utfstr = s.encode('utf-8') |
|
780 | 780 | length = len(utfstr) |
|
781 | 781 | if length > 64: |
|
782 | 782 | raise NamePartTooLongException |
|
783 | 783 | self.writeByte(length) |
|
784 | 784 | self.writeString(utfstr, length) |
|
785 | 785 | |
|
786 | 786 | def writeName(self, name): |
|
787 | 787 | """Writes a domain name to the packet""" |
|
788 | 788 | |
|
789 | 789 | try: |
|
790 | 790 | # Find existing instance of this name in packet |
|
791 | 791 | # |
|
792 | 792 | index = self.names[name] |
|
793 | 793 | except KeyError: |
|
794 | 794 | # No record of this name already, so write it |
|
795 | 795 | # out as normal, recording the location of the name |
|
796 | 796 | # for future pointers to it. |
|
797 | 797 | # |
|
798 | 798 | self.names[name] = self.size |
|
799 | 799 | parts = name.split(b'.') |
|
800 | 800 | if parts[-1] == b'': |
|
801 | 801 | parts = parts[:-1] |
|
802 | 802 | for part in parts: |
|
803 | 803 | self.writeUTF(part) |
|
804 | 804 | self.writeByte(0) |
|
805 | 805 | return |
|
806 | 806 | |
|
807 | 807 | # An index was found, so write a pointer to it |
|
808 | 808 | # |
|
809 | 809 | self.writeByte((index >> 8) | 0xC0) |
|
810 | 810 | self.writeByte(index) |
|
811 | 811 | |
|
812 | 812 | def writeQuestion(self, question): |
|
813 | 813 | """Writes a question to the packet""" |
|
814 | 814 | self.writeName(question.name) |
|
815 | 815 | self.writeShort(question.type) |
|
816 | 816 | self.writeShort(question.clazz) |
|
817 | 817 | |
|
818 | 818 | def writeRecord(self, record, now): |
|
819 | 819 | """Writes a record (answer, authoritative answer, additional) to |
|
820 | 820 | the packet""" |
|
821 | 821 | self.writeName(record.name) |
|
822 | 822 | self.writeShort(record.type) |
|
823 | 823 | if record.unique and self.multicast: |
|
824 | 824 | self.writeShort(record.clazz | _CLASS_UNIQUE) |
|
825 | 825 | else: |
|
826 | 826 | self.writeShort(record.clazz) |
|
827 | 827 | if now == 0: |
|
828 | 828 | self.writeInt(record.ttl) |
|
829 | 829 | else: |
|
830 | 830 | self.writeInt(record.getRemainingTTL(now)) |
|
831 | 831 | index = len(self.data) |
|
832 | 832 | # Adjust size for the short we will write before this record |
|
833 | 833 | # |
|
834 | 834 | self.size += 2 |
|
835 | 835 | record.write(self) |
|
836 | 836 | self.size -= 2 |
|
837 | 837 | |
|
838 | 838 | length = len(b''.join(self.data[index:])) |
|
839 | 839 | self.insertShort(index, length) # Here is the short we adjusted for |
|
840 | 840 | |
|
841 | 841 | def packet(self): |
|
842 | 842 | """Returns a string containing the packet's bytes |
|
843 | 843 | |
|
844 | 844 | No further parts should be added to the packet once this |
|
845 | 845 | is done.""" |
|
846 | 846 | if not self.finished: |
|
847 | 847 | self.finished = 1 |
|
848 | 848 | for question in self.questions: |
|
849 | 849 | self.writeQuestion(question) |
|
850 | 850 | for answer, time_ in self.answers: |
|
851 | 851 | self.writeRecord(answer, time_) |
|
852 | 852 | for authority in self.authorities: |
|
853 | 853 | self.writeRecord(authority, 0) |
|
854 | 854 | for additional in self.additionals: |
|
855 | 855 | self.writeRecord(additional, 0) |
|
856 | 856 | |
|
857 | 857 | self.insertShort(0, len(self.additionals)) |
|
858 | 858 | self.insertShort(0, len(self.authorities)) |
|
859 | 859 | self.insertShort(0, len(self.answers)) |
|
860 | 860 | self.insertShort(0, len(self.questions)) |
|
861 | 861 | self.insertShort(0, self.flags) |
|
862 | 862 | if self.multicast: |
|
863 | 863 | self.insertShort(0, 0) |
|
864 | 864 | else: |
|
865 | 865 | self.insertShort(0, self.id) |
|
866 | 866 | return b''.join(self.data) |
|
867 | 867 | |
|
868 | 868 | |
|
869 | 869 | class DNSCache(object): |
|
870 | 870 | """A cache of DNS entries""" |
|
871 | 871 | |
|
872 | 872 | def __init__(self): |
|
873 | 873 | self.cache = {} |
|
874 | 874 | |
|
875 | 875 | def add(self, entry): |
|
876 | 876 | """Adds an entry""" |
|
877 | 877 | try: |
|
878 | 878 | list = self.cache[entry.key] |
|
879 | 879 | except KeyError: |
|
880 | 880 | list = self.cache[entry.key] = [] |
|
881 | 881 | list.append(entry) |
|
882 | 882 | |
|
883 | 883 | def remove(self, entry): |
|
884 | 884 | """Removes an entry""" |
|
885 | 885 | try: |
|
886 | 886 | list = self.cache[entry.key] |
|
887 | 887 | list.remove(entry) |
|
888 | 888 | except KeyError: |
|
889 | 889 | pass |
|
890 | 890 | |
|
891 | 891 | def get(self, entry): |
|
892 | 892 | """Gets an entry by key. Will return None if there is no |
|
893 | 893 | matching entry.""" |
|
894 | 894 | try: |
|
895 | 895 | list = self.cache[entry.key] |
|
896 | 896 | return list[list.index(entry)] |
|
897 | 897 | except (KeyError, ValueError): |
|
898 | 898 | return None |
|
899 | 899 | |
|
900 | 900 | def getByDetails(self, name, type, clazz): |
|
901 | 901 | """Gets an entry by details. Will return None if there is |
|
902 | 902 | no matching entry.""" |
|
903 | 903 | entry = DNSEntry(name, type, clazz) |
|
904 | 904 | return self.get(entry) |
|
905 | 905 | |
|
906 | 906 | def entriesWithName(self, name): |
|
907 | 907 | """Returns a list of entries whose key matches the name.""" |
|
908 | 908 | try: |
|
909 | 909 | return self.cache[name] |
|
910 | 910 | except KeyError: |
|
911 | 911 | return [] |
|
912 | 912 | |
|
913 | 913 | def entries(self): |
|
914 | 914 | """Returns a list of all entries""" |
|
915 | 915 | try: |
|
916 | 916 | return list(itertools.chain.from_iterable(self.cache.values())) |
|
917 | 917 | except Exception: |
|
918 | 918 | return [] |
|
919 | 919 | |
|
920 | 920 | |
|
921 | 921 | class Engine(threading.Thread): |
|
922 | 922 | """An engine wraps read access to sockets, allowing objects that |
|
923 | 923 | need to receive data from sockets to be called back when the |
|
924 | 924 | sockets are ready. |
|
925 | 925 | |
|
926 | 926 | A reader needs a handle_read() method, which is called when the socket |
|
927 | 927 | it is interested in is ready for reading. |
|
928 | 928 | |
|
929 | 929 | Writers are not implemented here, because we only send short |
|
930 | 930 | packets. |
|
931 | 931 | """ |
|
932 | 932 | |
|
933 | 933 | def __init__(self, zeroconf): |
|
934 | 934 | threading.Thread.__init__(self) |
|
935 | 935 | self.zeroconf = zeroconf |
|
936 | 936 | self.readers = {} # maps socket to reader |
|
937 | 937 | self.timeout = 5 |
|
938 | 938 | self.condition = threading.Condition() |
|
939 | 939 | self.start() |
|
940 | 940 | |
|
941 | 941 | def run(self): |
|
942 | 942 | while not globals()[b'_GLOBAL_DONE']: |
|
943 | 943 | rs = self.getReaders() |
|
944 | 944 | if len(rs) == 0: |
|
945 | 945 | # No sockets to manage, but we wait for the timeout |
|
946 | 946 | # or addition of a socket |
|
947 | 947 | # |
|
948 | 948 | self.condition.acquire() |
|
949 | 949 | self.condition.wait(self.timeout) |
|
950 | 950 | self.condition.release() |
|
951 | 951 | else: |
|
952 | 952 | try: |
|
953 | 953 | rr, wr, er = select.select(rs, [], [], self.timeout) |
|
954 | 954 | for sock in rr: |
|
955 | 955 | try: |
|
956 | 956 | self.readers[sock].handle_read() |
|
957 | 957 | except Exception: |
|
958 | 958 | if not globals()[b'_GLOBAL_DONE']: |
|
959 | 959 | traceback.print_exc() |
|
960 | 960 | except Exception: |
|
961 | 961 | pass |
|
962 | 962 | |
|
963 | 963 | def getReaders(self): |
|
964 | 964 | self.condition.acquire() |
|
965 | 965 | result = self.readers.keys() |
|
966 | 966 | self.condition.release() |
|
967 | 967 | return result |
|
968 | 968 | |
|
969 | 969 | def addReader(self, reader, socket): |
|
970 | 970 | self.condition.acquire() |
|
971 | 971 | self.readers[socket] = reader |
|
972 | 972 | self.condition.notify() |
|
973 | 973 | self.condition.release() |
|
974 | 974 | |
|
975 | 975 | def delReader(self, socket): |
|
976 | 976 | self.condition.acquire() |
|
977 | 977 | del self.readers[socket] |
|
978 | 978 | self.condition.notify() |
|
979 | 979 | self.condition.release() |
|
980 | 980 | |
|
981 | 981 | def notify(self): |
|
982 | 982 | self.condition.acquire() |
|
983 | 983 | self.condition.notify() |
|
984 | 984 | self.condition.release() |
|
985 | 985 | |
|
986 | 986 | |
|
987 | 987 | class Listener(object): |
|
988 | 988 | """A Listener is used by this module to listen on the multicast |
|
989 | 989 | group to which DNS messages are sent, allowing the implementation |
|
990 | 990 | to cache information as it arrives. |
|
991 | 991 | |
|
992 | 992 | It requires registration with an Engine object in order to have |
|
993 | 993 | the read() method called when a socket is available for reading.""" |
|
994 | 994 | |
|
995 | 995 | def __init__(self, zeroconf): |
|
996 | 996 | self.zeroconf = zeroconf |
|
997 | 997 | self.zeroconf.engine.addReader(self, self.zeroconf.socket) |
|
998 | 998 | |
|
999 | 999 | def handle_read(self): |
|
1000 | 1000 | sock = self.zeroconf.socket |
|
1001 | 1001 | try: |
|
1002 | 1002 | data, (addr, port) = sock.recvfrom(_MAX_MSG_ABSOLUTE) |
|
1003 | 1003 | except socket.error as e: |
|
1004 | 1004 | if e.errno == errno.EBADF: |
|
1005 | 1005 | # some other thread may close the socket |
|
1006 | 1006 | return |
|
1007 | 1007 | else: |
|
1008 | 1008 | raise |
|
1009 | 1009 | self.data = data |
|
1010 | 1010 | msg = DNSIncoming(data) |
|
1011 | 1011 | if msg.isQuery(): |
|
1012 | 1012 | # Always multicast responses |
|
1013 | 1013 | # |
|
1014 | 1014 | if port == _MDNS_PORT: |
|
1015 | 1015 | self.zeroconf.handleQuery(msg, _MDNS_ADDR, _MDNS_PORT) |
|
1016 | 1016 | # If it's not a multicast query, reply via unicast |
|
1017 | 1017 | # and multicast |
|
1018 | 1018 | # |
|
1019 | 1019 | elif port == _DNS_PORT: |
|
1020 | 1020 | self.zeroconf.handleQuery(msg, addr, port) |
|
1021 | 1021 | self.zeroconf.handleQuery(msg, _MDNS_ADDR, _MDNS_PORT) |
|
1022 | 1022 | else: |
|
1023 | 1023 | self.zeroconf.handleResponse(msg) |
|
1024 | 1024 | |
|
1025 | 1025 | |
|
1026 | 1026 | class Reaper(threading.Thread): |
|
1027 | 1027 | """A Reaper is used by this module to remove cache entries that |
|
1028 | 1028 | have expired.""" |
|
1029 | 1029 | |
|
1030 | 1030 | def __init__(self, zeroconf): |
|
1031 | 1031 | threading.Thread.__init__(self) |
|
1032 | 1032 | self.zeroconf = zeroconf |
|
1033 | 1033 | self.start() |
|
1034 | 1034 | |
|
1035 | 1035 | def run(self): |
|
1036 | 1036 | while True: |
|
1037 | 1037 | self.zeroconf.wait(10 * 1000) |
|
1038 | 1038 | if globals()[b'_GLOBAL_DONE']: |
|
1039 | 1039 | return |
|
1040 | 1040 | now = currentTimeMillis() |
|
1041 | 1041 | for record in self.zeroconf.cache.entries(): |
|
1042 | 1042 | if record.isExpired(now): |
|
1043 | 1043 | self.zeroconf.updateRecord(now, record) |
|
1044 | 1044 | self.zeroconf.cache.remove(record) |
|
1045 | 1045 | |
|
1046 | 1046 | |
|
1047 | 1047 | class ServiceBrowser(threading.Thread): |
|
1048 | 1048 | """Used to browse for a service of a specific type. |
|
1049 | 1049 | |
|
1050 | 1050 | The listener object will have its addService() and |
|
1051 | 1051 | removeService() methods called when this browser |
|
1052 | 1052 | discovers changes in the services availability.""" |
|
1053 | 1053 | |
|
1054 | 1054 | def __init__(self, zeroconf, type, listener): |
|
1055 | 1055 | """Creates a browser for a specific type""" |
|
1056 | 1056 | threading.Thread.__init__(self) |
|
1057 | 1057 | self.zeroconf = zeroconf |
|
1058 | 1058 | self.type = type |
|
1059 | 1059 | self.listener = listener |
|
1060 | 1060 | self.services = {} |
|
1061 | 1061 | self.nexttime = currentTimeMillis() |
|
1062 | 1062 | self.delay = _BROWSER_TIME |
|
1063 | 1063 | self.list = [] |
|
1064 | 1064 | |
|
1065 | 1065 | self.done = 0 |
|
1066 | 1066 | |
|
1067 | 1067 | self.zeroconf.addListener( |
|
1068 | 1068 | self, DNSQuestion(self.type, _TYPE_PTR, _CLASS_IN) |
|
1069 | 1069 | ) |
|
1070 | 1070 | self.start() |
|
1071 | 1071 | |
|
1072 | 1072 | def updateRecord(self, zeroconf, now, record): |
|
1073 | 1073 | """Callback invoked by Zeroconf when new information arrives. |
|
1074 | 1074 | |
|
1075 | 1075 | Updates information required by browser in the Zeroconf cache.""" |
|
1076 | 1076 | if record.type == _TYPE_PTR and record.name == self.type: |
|
1077 | 1077 | expired = record.isExpired(now) |
|
1078 | 1078 | try: |
|
1079 | 1079 | oldrecord = self.services[record.alias.lower()] |
|
1080 | 1080 | if not expired: |
|
1081 | 1081 | oldrecord.resetTTL(record) |
|
1082 | 1082 | else: |
|
1083 | 1083 | del self.services[record.alias.lower()] |
|
1084 | 1084 | callback = lambda x: self.listener.removeService( |
|
1085 | 1085 | x, self.type, record.alias |
|
1086 | 1086 | ) |
|
1087 | 1087 | self.list.append(callback) |
|
1088 | 1088 | return |
|
1089 | 1089 | except Exception: |
|
1090 | 1090 | if not expired: |
|
1091 | 1091 | self.services[record.alias.lower()] = record |
|
1092 | 1092 | callback = lambda x: self.listener.addService( |
|
1093 | 1093 | x, self.type, record.alias |
|
1094 | 1094 | ) |
|
1095 | 1095 | self.list.append(callback) |
|
1096 | 1096 | |
|
1097 | 1097 | expires = record.getExpirationTime(75) |
|
1098 | 1098 | if expires < self.nexttime: |
|
1099 | 1099 | self.nexttime = expires |
|
1100 | 1100 | |
|
1101 | 1101 | def cancel(self): |
|
1102 | 1102 | self.done = 1 |
|
1103 | 1103 | self.zeroconf.notifyAll() |
|
1104 | 1104 | |
|
1105 | 1105 | def run(self): |
|
1106 | 1106 | while True: |
|
1107 | 1107 | event = None |
|
1108 | 1108 | now = currentTimeMillis() |
|
1109 | 1109 | if len(self.list) == 0 and self.nexttime > now: |
|
1110 | 1110 | self.zeroconf.wait(self.nexttime - now) |
|
1111 | 1111 | if globals()[b'_GLOBAL_DONE'] or self.done: |
|
1112 | 1112 | return |
|
1113 | 1113 | now = currentTimeMillis() |
|
1114 | 1114 | |
|
1115 | 1115 | if self.nexttime <= now: |
|
1116 | 1116 | out = DNSOutgoing(_FLAGS_QR_QUERY) |
|
1117 | 1117 | out.addQuestion(DNSQuestion(self.type, _TYPE_PTR, _CLASS_IN)) |
|
1118 | 1118 | for record in self.services.values(): |
|
1119 | 1119 | if not record.isExpired(now): |
|
1120 | 1120 | out.addAnswerAtTime(record, now) |
|
1121 | 1121 | self.zeroconf.send(out) |
|
1122 | 1122 | self.nexttime = now + self.delay |
|
1123 | 1123 | self.delay = min(20 * 1000, self.delay * 2) |
|
1124 | 1124 | |
|
1125 | 1125 | if len(self.list) > 0: |
|
1126 | 1126 | event = self.list.pop(0) |
|
1127 | 1127 | |
|
1128 | 1128 | if event is not None: |
|
1129 | 1129 | event(self.zeroconf) |
|
1130 | 1130 | |
|
1131 | 1131 | |
|
1132 | 1132 | class ServiceInfo(object): |
|
1133 | 1133 | """Service information""" |
|
1134 | 1134 | |
|
1135 | 1135 | def __init__( |
|
1136 | 1136 | self, |
|
1137 | 1137 | type, |
|
1138 | 1138 | name, |
|
1139 | 1139 | address=None, |
|
1140 | 1140 | port=None, |
|
1141 | 1141 | weight=0, |
|
1142 | 1142 | priority=0, |
|
1143 | 1143 | properties=None, |
|
1144 | 1144 | server=None, |
|
1145 | 1145 | ): |
|
1146 | 1146 | """Create a service description. |
|
1147 | 1147 | |
|
1148 | 1148 | type: fully qualified service type name |
|
1149 | 1149 | name: fully qualified service name |
|
1150 | 1150 | address: IP address as unsigned short, network byte order |
|
1151 | 1151 | port: port that the service runs on |
|
1152 | 1152 | weight: weight of the service |
|
1153 | 1153 | priority: priority of the service |
|
1154 | 1154 | properties: dictionary of properties (or a string holding the bytes for |
|
1155 | 1155 | the text field) |
|
1156 | 1156 | server: fully qualified name for service host (defaults to name)""" |
|
1157 | 1157 | |
|
1158 | 1158 | if not name.endswith(type): |
|
1159 | 1159 | raise BadTypeInNameException |
|
1160 | 1160 | self.type = type |
|
1161 | 1161 | self.name = name |
|
1162 | 1162 | self.address = address |
|
1163 | 1163 | self.port = port |
|
1164 | 1164 | self.weight = weight |
|
1165 | 1165 | self.priority = priority |
|
1166 | 1166 | if server: |
|
1167 | 1167 | self.server = server |
|
1168 | 1168 | else: |
|
1169 | 1169 | self.server = name |
|
1170 | 1170 | self.setProperties(properties) |
|
1171 | 1171 | |
|
1172 | 1172 | def setProperties(self, properties): |
|
1173 | 1173 | """Sets properties and text of this info from a dictionary""" |
|
1174 | 1174 | if isinstance(properties, dict): |
|
1175 | 1175 | self.properties = properties |
|
1176 | 1176 | list = [] |
|
1177 | 1177 | result = b'' |
|
1178 | 1178 | for key in properties: |
|
1179 | 1179 | value = properties[key] |
|
1180 | 1180 | if value is None: |
|
1181 | 1181 | suffix = b'' |
|
1182 | 1182 | elif isinstance(value, str): |
|
1183 | 1183 | suffix = value |
|
1184 | 1184 | elif isinstance(value, int): |
|
1185 | 1185 | if value: |
|
1186 | 1186 | suffix = b'true' |
|
1187 | 1187 | else: |
|
1188 | 1188 | suffix = b'false' |
|
1189 | 1189 | else: |
|
1190 | 1190 | suffix = b'' |
|
1191 | 1191 | list.append(b'='.join((key, suffix))) |
|
1192 | 1192 | for item in list: |
|
1193 | 1193 | result = b''.join( |
|
1194 | (result, struct.pack(b'!c', chr(len(item))), item) | |
|
1194 | ( | |
|
1195 | result, | |
|
1196 | struct.pack(b'!c', pycompat.bytechr(len(item))), | |
|
1197 | item, | |
|
1198 | ) | |
|
1195 | 1199 | ) |
|
1196 | 1200 | self.text = result |
|
1197 | 1201 | else: |
|
1198 | 1202 | self.text = properties |
|
1199 | 1203 | |
|
1200 | 1204 | def setText(self, text): |
|
1201 | 1205 | """Sets properties and text given a text field""" |
|
1202 | 1206 | self.text = text |
|
1203 | 1207 | try: |
|
1204 | 1208 | result = {} |
|
1205 | 1209 | end = len(text) |
|
1206 | 1210 | index = 0 |
|
1207 | 1211 | strs = [] |
|
1208 | 1212 | while index < end: |
|
1209 | 1213 | length = ord(text[index]) |
|
1210 | 1214 | index += 1 |
|
1211 | 1215 | strs.append(text[index : index + length]) |
|
1212 | 1216 | index += length |
|
1213 | 1217 | |
|
1214 | 1218 | for s in strs: |
|
1215 | 1219 | eindex = s.find(b'=') |
|
1216 | 1220 | if eindex == -1: |
|
1217 | 1221 | # No equals sign at all |
|
1218 | 1222 | key = s |
|
1219 | 1223 | value = 0 |
|
1220 | 1224 | else: |
|
1221 | 1225 | key = s[:eindex] |
|
1222 | 1226 | value = s[eindex + 1 :] |
|
1223 | 1227 | if value == b'true': |
|
1224 | 1228 | value = 1 |
|
1225 | 1229 | elif value == b'false' or not value: |
|
1226 | 1230 | value = 0 |
|
1227 | 1231 | |
|
1228 | 1232 | # Only update non-existent properties |
|
1229 | 1233 | if key and result.get(key) is None: |
|
1230 | 1234 | result[key] = value |
|
1231 | 1235 | |
|
1232 | 1236 | self.properties = result |
|
1233 | 1237 | except Exception: |
|
1234 | 1238 | traceback.print_exc() |
|
1235 | 1239 | self.properties = None |
|
1236 | 1240 | |
|
1237 | 1241 | def getType(self): |
|
1238 | 1242 | """Type accessor""" |
|
1239 | 1243 | return self.type |
|
1240 | 1244 | |
|
1241 | 1245 | def getName(self): |
|
1242 | 1246 | """Name accessor""" |
|
1243 | 1247 | if self.type is not None and self.name.endswith(b"." + self.type): |
|
1244 | 1248 | return self.name[: len(self.name) - len(self.type) - 1] |
|
1245 | 1249 | return self.name |
|
1246 | 1250 | |
|
1247 | 1251 | def getAddress(self): |
|
1248 | 1252 | """Address accessor""" |
|
1249 | 1253 | return self.address |
|
1250 | 1254 | |
|
1251 | 1255 | def getPort(self): |
|
1252 | 1256 | """Port accessor""" |
|
1253 | 1257 | return self.port |
|
1254 | 1258 | |
|
1255 | 1259 | def getPriority(self): |
|
1256 | 1260 | """Priority accessor""" |
|
1257 | 1261 | return self.priority |
|
1258 | 1262 | |
|
1259 | 1263 | def getWeight(self): |
|
1260 | 1264 | """Weight accessor""" |
|
1261 | 1265 | return self.weight |
|
1262 | 1266 | |
|
1263 | 1267 | def getProperties(self): |
|
1264 | 1268 | """Properties accessor""" |
|
1265 | 1269 | return self.properties |
|
1266 | 1270 | |
|
1267 | 1271 | def getText(self): |
|
1268 | 1272 | """Text accessor""" |
|
1269 | 1273 | return self.text |
|
1270 | 1274 | |
|
1271 | 1275 | def getServer(self): |
|
1272 | 1276 | """Server accessor""" |
|
1273 | 1277 | return self.server |
|
1274 | 1278 | |
|
1275 | 1279 | def updateRecord(self, zeroconf, now, record): |
|
1276 | 1280 | """Updates service information from a DNS record""" |
|
1277 | 1281 | if record is not None and not record.isExpired(now): |
|
1278 | 1282 | if record.type == _TYPE_A: |
|
1279 | 1283 | # if record.name == self.name: |
|
1280 | 1284 | if record.name == self.server: |
|
1281 | 1285 | self.address = record.address |
|
1282 | 1286 | elif record.type == _TYPE_SRV: |
|
1283 | 1287 | if record.name == self.name: |
|
1284 | 1288 | self.server = record.server |
|
1285 | 1289 | self.port = record.port |
|
1286 | 1290 | self.weight = record.weight |
|
1287 | 1291 | self.priority = record.priority |
|
1288 | 1292 | # self.address = None |
|
1289 | 1293 | self.updateRecord( |
|
1290 | 1294 | zeroconf, |
|
1291 | 1295 | now, |
|
1292 | 1296 | zeroconf.cache.getByDetails( |
|
1293 | 1297 | self.server, _TYPE_A, _CLASS_IN |
|
1294 | 1298 | ), |
|
1295 | 1299 | ) |
|
1296 | 1300 | elif record.type == _TYPE_TXT: |
|
1297 | 1301 | if record.name == self.name: |
|
1298 | 1302 | self.setText(record.text) |
|
1299 | 1303 | |
|
1300 | 1304 | def request(self, zeroconf, timeout): |
|
1301 | 1305 | """Returns true if the service could be discovered on the |
|
1302 | 1306 | network, and updates this object with details discovered. |
|
1303 | 1307 | """ |
|
1304 | 1308 | now = currentTimeMillis() |
|
1305 | 1309 | delay = _LISTENER_TIME |
|
1306 | 1310 | next = now + delay |
|
1307 | 1311 | last = now + timeout |
|
1308 | 1312 | try: |
|
1309 | 1313 | zeroconf.addListener( |
|
1310 | 1314 | self, DNSQuestion(self.name, _TYPE_ANY, _CLASS_IN) |
|
1311 | 1315 | ) |
|
1312 | 1316 | while ( |
|
1313 | 1317 | self.server is None or self.address is None or self.text is None |
|
1314 | 1318 | ): |
|
1315 | 1319 | if last <= now: |
|
1316 | 1320 | return 0 |
|
1317 | 1321 | if next <= now: |
|
1318 | 1322 | out = DNSOutgoing(_FLAGS_QR_QUERY) |
|
1319 | 1323 | out.addQuestion( |
|
1320 | 1324 | DNSQuestion(self.name, _TYPE_SRV, _CLASS_IN) |
|
1321 | 1325 | ) |
|
1322 | 1326 | out.addAnswerAtTime( |
|
1323 | 1327 | zeroconf.cache.getByDetails( |
|
1324 | 1328 | self.name, _TYPE_SRV, _CLASS_IN |
|
1325 | 1329 | ), |
|
1326 | 1330 | now, |
|
1327 | 1331 | ) |
|
1328 | 1332 | out.addQuestion( |
|
1329 | 1333 | DNSQuestion(self.name, _TYPE_TXT, _CLASS_IN) |
|
1330 | 1334 | ) |
|
1331 | 1335 | out.addAnswerAtTime( |
|
1332 | 1336 | zeroconf.cache.getByDetails( |
|
1333 | 1337 | self.name, _TYPE_TXT, _CLASS_IN |
|
1334 | 1338 | ), |
|
1335 | 1339 | now, |
|
1336 | 1340 | ) |
|
1337 | 1341 | if self.server is not None: |
|
1338 | 1342 | out.addQuestion( |
|
1339 | 1343 | DNSQuestion(self.server, _TYPE_A, _CLASS_IN) |
|
1340 | 1344 | ) |
|
1341 | 1345 | out.addAnswerAtTime( |
|
1342 | 1346 | zeroconf.cache.getByDetails( |
|
1343 | 1347 | self.server, _TYPE_A, _CLASS_IN |
|
1344 | 1348 | ), |
|
1345 | 1349 | now, |
|
1346 | 1350 | ) |
|
1347 | 1351 | zeroconf.send(out) |
|
1348 | 1352 | next = now + delay |
|
1349 | 1353 | delay = delay * 2 |
|
1350 | 1354 | |
|
1351 | 1355 | zeroconf.wait(min(next, last) - now) |
|
1352 | 1356 | now = currentTimeMillis() |
|
1353 | 1357 | result = 1 |
|
1354 | 1358 | finally: |
|
1355 | 1359 | zeroconf.removeListener(self) |
|
1356 | 1360 | |
|
1357 | 1361 | return result |
|
1358 | 1362 | |
|
1359 | 1363 | def __eq__(self, other): |
|
1360 | 1364 | """Tests equality of service name""" |
|
1361 | 1365 | if isinstance(other, ServiceInfo): |
|
1362 | 1366 | return other.name == self.name |
|
1363 | 1367 | return 0 |
|
1364 | 1368 | |
|
1365 | 1369 | def __ne__(self, other): |
|
1366 | 1370 | """Non-equality test""" |
|
1367 | 1371 | return not self.__eq__(other) |
|
1368 | 1372 | |
|
1369 | 1373 | def __repr__(self): |
|
1370 | 1374 | """String representation""" |
|
1371 | 1375 | result = b"service[%s,%s:%s," % ( |
|
1372 | 1376 | self.name, |
|
1373 | 1377 | socket.inet_ntoa(self.getAddress()), |
|
1374 | 1378 | self.port, |
|
1375 | 1379 | ) |
|
1376 | 1380 | if self.text is None: |
|
1377 | 1381 | result += b"None" |
|
1378 | 1382 | else: |
|
1379 | 1383 | if len(self.text) < 20: |
|
1380 | 1384 | result += self.text |
|
1381 | 1385 | else: |
|
1382 | 1386 | result += self.text[:17] + b"..." |
|
1383 | 1387 | result += b"]" |
|
1384 | 1388 | return result |
|
1385 | 1389 | |
|
1386 | 1390 | |
|
1387 | 1391 | class Zeroconf(object): |
|
1388 | 1392 | """Implementation of Zeroconf Multicast DNS Service Discovery |
|
1389 | 1393 | |
|
1390 | 1394 | Supports registration, unregistration, queries and browsing. |
|
1391 | 1395 | """ |
|
1392 | 1396 | |
|
1393 | 1397 | def __init__(self, bindaddress=None): |
|
1394 | 1398 | """Creates an instance of the Zeroconf class, establishing |
|
1395 | 1399 | multicast communications, listening and reaping threads.""" |
|
1396 | 1400 | globals()[b'_GLOBAL_DONE'] = 0 |
|
1397 | 1401 | if bindaddress is None: |
|
1398 | 1402 | self.intf = socket.gethostbyname(socket.gethostname()) |
|
1399 | 1403 | else: |
|
1400 | 1404 | self.intf = bindaddress |
|
1401 | 1405 | self.group = (b'', _MDNS_PORT) |
|
1402 | 1406 | self.socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) |
|
1403 | 1407 | try: |
|
1404 | 1408 | self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) |
|
1405 | 1409 | self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEPORT, 1) |
|
1406 | 1410 | except Exception: |
|
1407 | 1411 | # SO_REUSEADDR should be equivalent to SO_REUSEPORT for |
|
1408 | 1412 | # multicast UDP sockets (p 731, "TCP/IP Illustrated, |
|
1409 | 1413 | # Volume 2"), but some BSD-derived systems require |
|
1410 | 1414 | # SO_REUSEPORT to be specified explicitly. Also, not all |
|
1411 | 1415 | # versions of Python have SO_REUSEPORT available. So |
|
1412 | 1416 | # if you're on a BSD-based system, and haven't upgraded |
|
1413 | 1417 | # to Python 2.3 yet, you may find this library doesn't |
|
1414 | 1418 | # work as expected. |
|
1415 | 1419 | # |
|
1416 | 1420 | pass |
|
1417 | 1421 | self.socket.setsockopt(socket.SOL_IP, socket.IP_MULTICAST_TTL, b"\xff") |
|
1418 | 1422 | self.socket.setsockopt(socket.SOL_IP, socket.IP_MULTICAST_LOOP, b"\x01") |
|
1419 | 1423 | try: |
|
1420 | 1424 | self.socket.bind(self.group) |
|
1421 | 1425 | except Exception: |
|
1422 | 1426 | # Some versions of linux raise an exception even though |
|
1423 | 1427 | # SO_REUSEADDR and SO_REUSEPORT have been set, so ignore it |
|
1424 | 1428 | pass |
|
1425 | 1429 | self.socket.setsockopt( |
|
1426 | 1430 | socket.SOL_IP, |
|
1427 | 1431 | socket.IP_ADD_MEMBERSHIP, |
|
1428 | 1432 | socket.inet_aton(_MDNS_ADDR) + socket.inet_aton(r'0.0.0.0'), |
|
1429 | 1433 | ) |
|
1430 | 1434 | |
|
1431 | 1435 | self.listeners = [] |
|
1432 | 1436 | self.browsers = [] |
|
1433 | 1437 | self.services = {} |
|
1434 | 1438 | self.servicetypes = {} |
|
1435 | 1439 | |
|
1436 | 1440 | self.cache = DNSCache() |
|
1437 | 1441 | |
|
1438 | 1442 | self.condition = threading.Condition() |
|
1439 | 1443 | |
|
1440 | 1444 | self.engine = Engine(self) |
|
1441 | 1445 | self.listener = Listener(self) |
|
1442 | 1446 | self.reaper = Reaper(self) |
|
1443 | 1447 | |
|
1444 | 1448 | def isLoopback(self): |
|
1445 | 1449 | return self.intf.startswith(b"127.0.0.1") |
|
1446 | 1450 | |
|
1447 | 1451 | def isLinklocal(self): |
|
1448 | 1452 | return self.intf.startswith(b"169.254.") |
|
1449 | 1453 | |
|
1450 | 1454 | def wait(self, timeout): |
|
1451 | 1455 | """Calling thread waits for a given number of milliseconds or |
|
1452 | 1456 | until notified.""" |
|
1453 | 1457 | self.condition.acquire() |
|
1454 | 1458 | self.condition.wait(timeout / 1000) |
|
1455 | 1459 | self.condition.release() |
|
1456 | 1460 | |
|
1457 | 1461 | def notifyAll(self): |
|
1458 | 1462 | """Notifies all waiting threads""" |
|
1459 | 1463 | self.condition.acquire() |
|
1460 | 1464 | self.condition.notifyAll() |
|
1461 | 1465 | self.condition.release() |
|
1462 | 1466 | |
|
1463 | 1467 | def getServiceInfo(self, type, name, timeout=3000): |
|
1464 | 1468 | """Returns network's service information for a particular |
|
1465 | 1469 | name and type, or None if no service matches by the timeout, |
|
1466 | 1470 | which defaults to 3 seconds.""" |
|
1467 | 1471 | info = ServiceInfo(type, name) |
|
1468 | 1472 | if info.request(self, timeout): |
|
1469 | 1473 | return info |
|
1470 | 1474 | return None |
|
1471 | 1475 | |
|
1472 | 1476 | def addServiceListener(self, type, listener): |
|
1473 | 1477 | """Adds a listener for a particular service type. This object |
|
1474 | 1478 | will then have its updateRecord method called when information |
|
1475 | 1479 | arrives for that type.""" |
|
1476 | 1480 | self.removeServiceListener(listener) |
|
1477 | 1481 | self.browsers.append(ServiceBrowser(self, type, listener)) |
|
1478 | 1482 | |
|
1479 | 1483 | def removeServiceListener(self, listener): |
|
1480 | 1484 | """Removes a listener from the set that is currently listening.""" |
|
1481 | 1485 | for browser in self.browsers: |
|
1482 | 1486 | if browser.listener == listener: |
|
1483 | 1487 | browser.cancel() |
|
1484 | 1488 | del browser |
|
1485 | 1489 | |
|
1486 | 1490 | def registerService(self, info, ttl=_DNS_TTL): |
|
1487 | 1491 | """Registers service information to the network with a default TTL |
|
1488 | 1492 | of 60 seconds. Zeroconf will then respond to requests for |
|
1489 | 1493 | information for that service. The name of the service may be |
|
1490 | 1494 | changed if needed to make it unique on the network.""" |
|
1491 | 1495 | self.checkService(info) |
|
1492 | 1496 | self.services[info.name.lower()] = info |
|
1493 | 1497 | if info.type in self.servicetypes: |
|
1494 | 1498 | self.servicetypes[info.type] += 1 |
|
1495 | 1499 | else: |
|
1496 | 1500 | self.servicetypes[info.type] = 1 |
|
1497 | 1501 | now = currentTimeMillis() |
|
1498 | 1502 | nexttime = now |
|
1499 | 1503 | i = 0 |
|
1500 | 1504 | while i < 3: |
|
1501 | 1505 | if now < nexttime: |
|
1502 | 1506 | self.wait(nexttime - now) |
|
1503 | 1507 | now = currentTimeMillis() |
|
1504 | 1508 | continue |
|
1505 | 1509 | out = DNSOutgoing(_FLAGS_QR_RESPONSE | _FLAGS_AA) |
|
1506 | 1510 | out.addAnswerAtTime( |
|
1507 | 1511 | DNSPointer(info.type, _TYPE_PTR, _CLASS_IN, ttl, info.name), 0 |
|
1508 | 1512 | ) |
|
1509 | 1513 | out.addAnswerAtTime( |
|
1510 | 1514 | DNSService( |
|
1511 | 1515 | info.name, |
|
1512 | 1516 | _TYPE_SRV, |
|
1513 | 1517 | _CLASS_IN, |
|
1514 | 1518 | ttl, |
|
1515 | 1519 | info.priority, |
|
1516 | 1520 | info.weight, |
|
1517 | 1521 | info.port, |
|
1518 | 1522 | info.server, |
|
1519 | 1523 | ), |
|
1520 | 1524 | 0, |
|
1521 | 1525 | ) |
|
1522 | 1526 | out.addAnswerAtTime( |
|
1523 | 1527 | DNSText(info.name, _TYPE_TXT, _CLASS_IN, ttl, info.text), 0 |
|
1524 | 1528 | ) |
|
1525 | 1529 | if info.address: |
|
1526 | 1530 | out.addAnswerAtTime( |
|
1527 | 1531 | DNSAddress( |
|
1528 | 1532 | info.server, _TYPE_A, _CLASS_IN, ttl, info.address |
|
1529 | 1533 | ), |
|
1530 | 1534 | 0, |
|
1531 | 1535 | ) |
|
1532 | 1536 | self.send(out) |
|
1533 | 1537 | i += 1 |
|
1534 | 1538 | nexttime += _REGISTER_TIME |
|
1535 | 1539 | |
|
1536 | 1540 | def unregisterService(self, info): |
|
1537 | 1541 | """Unregister a service.""" |
|
1538 | 1542 | try: |
|
1539 | 1543 | del self.services[info.name.lower()] |
|
1540 | 1544 | if self.servicetypes[info.type] > 1: |
|
1541 | 1545 | self.servicetypes[info.type] -= 1 |
|
1542 | 1546 | else: |
|
1543 | 1547 | del self.servicetypes[info.type] |
|
1544 | 1548 | except KeyError: |
|
1545 | 1549 | pass |
|
1546 | 1550 | now = currentTimeMillis() |
|
1547 | 1551 | nexttime = now |
|
1548 | 1552 | i = 0 |
|
1549 | 1553 | while i < 3: |
|
1550 | 1554 | if now < nexttime: |
|
1551 | 1555 | self.wait(nexttime - now) |
|
1552 | 1556 | now = currentTimeMillis() |
|
1553 | 1557 | continue |
|
1554 | 1558 | out = DNSOutgoing(_FLAGS_QR_RESPONSE | _FLAGS_AA) |
|
1555 | 1559 | out.addAnswerAtTime( |
|
1556 | 1560 | DNSPointer(info.type, _TYPE_PTR, _CLASS_IN, 0, info.name), 0 |
|
1557 | 1561 | ) |
|
1558 | 1562 | out.addAnswerAtTime( |
|
1559 | 1563 | DNSService( |
|
1560 | 1564 | info.name, |
|
1561 | 1565 | _TYPE_SRV, |
|
1562 | 1566 | _CLASS_IN, |
|
1563 | 1567 | 0, |
|
1564 | 1568 | info.priority, |
|
1565 | 1569 | info.weight, |
|
1566 | 1570 | info.port, |
|
1567 | 1571 | info.name, |
|
1568 | 1572 | ), |
|
1569 | 1573 | 0, |
|
1570 | 1574 | ) |
|
1571 | 1575 | out.addAnswerAtTime( |
|
1572 | 1576 | DNSText(info.name, _TYPE_TXT, _CLASS_IN, 0, info.text), 0 |
|
1573 | 1577 | ) |
|
1574 | 1578 | if info.address: |
|
1575 | 1579 | out.addAnswerAtTime( |
|
1576 | 1580 | DNSAddress( |
|
1577 | 1581 | info.server, _TYPE_A, _CLASS_IN, 0, info.address |
|
1578 | 1582 | ), |
|
1579 | 1583 | 0, |
|
1580 | 1584 | ) |
|
1581 | 1585 | self.send(out) |
|
1582 | 1586 | i += 1 |
|
1583 | 1587 | nexttime += _UNREGISTER_TIME |
|
1584 | 1588 | |
|
1585 | 1589 | def unregisterAllServices(self): |
|
1586 | 1590 | """Unregister all registered services.""" |
|
1587 | 1591 | if len(self.services) > 0: |
|
1588 | 1592 | now = currentTimeMillis() |
|
1589 | 1593 | nexttime = now |
|
1590 | 1594 | i = 0 |
|
1591 | 1595 | while i < 3: |
|
1592 | 1596 | if now < nexttime: |
|
1593 | 1597 | self.wait(nexttime - now) |
|
1594 | 1598 | now = currentTimeMillis() |
|
1595 | 1599 | continue |
|
1596 | 1600 | out = DNSOutgoing(_FLAGS_QR_RESPONSE | _FLAGS_AA) |
|
1597 | 1601 | for info in self.services.values(): |
|
1598 | 1602 | out.addAnswerAtTime( |
|
1599 | 1603 | DNSPointer( |
|
1600 | 1604 | info.type, _TYPE_PTR, _CLASS_IN, 0, info.name |
|
1601 | 1605 | ), |
|
1602 | 1606 | 0, |
|
1603 | 1607 | ) |
|
1604 | 1608 | out.addAnswerAtTime( |
|
1605 | 1609 | DNSService( |
|
1606 | 1610 | info.name, |
|
1607 | 1611 | _TYPE_SRV, |
|
1608 | 1612 | _CLASS_IN, |
|
1609 | 1613 | 0, |
|
1610 | 1614 | info.priority, |
|
1611 | 1615 | info.weight, |
|
1612 | 1616 | info.port, |
|
1613 | 1617 | info.server, |
|
1614 | 1618 | ), |
|
1615 | 1619 | 0, |
|
1616 | 1620 | ) |
|
1617 | 1621 | out.addAnswerAtTime( |
|
1618 | 1622 | DNSText(info.name, _TYPE_TXT, _CLASS_IN, 0, info.text), |
|
1619 | 1623 | 0, |
|
1620 | 1624 | ) |
|
1621 | 1625 | if info.address: |
|
1622 | 1626 | out.addAnswerAtTime( |
|
1623 | 1627 | DNSAddress( |
|
1624 | 1628 | info.server, _TYPE_A, _CLASS_IN, 0, info.address |
|
1625 | 1629 | ), |
|
1626 | 1630 | 0, |
|
1627 | 1631 | ) |
|
1628 | 1632 | self.send(out) |
|
1629 | 1633 | i += 1 |
|
1630 | 1634 | nexttime += _UNREGISTER_TIME |
|
1631 | 1635 | |
|
1632 | 1636 | def checkService(self, info): |
|
1633 | 1637 | """Checks the network for a unique service name, modifying the |
|
1634 | 1638 | ServiceInfo passed in if it is not unique.""" |
|
1635 | 1639 | now = currentTimeMillis() |
|
1636 | 1640 | nexttime = now |
|
1637 | 1641 | i = 0 |
|
1638 | 1642 | while i < 3: |
|
1639 | 1643 | for record in self.cache.entriesWithName(info.type): |
|
1640 | 1644 | if ( |
|
1641 | 1645 | record.type == _TYPE_PTR |
|
1642 | 1646 | and not record.isExpired(now) |
|
1643 | 1647 | and record.alias == info.name |
|
1644 | 1648 | ): |
|
1645 | 1649 | if info.name.find(b'.') < 0: |
|
1646 | 1650 | info.name = b"%w.[%s:%d].%s" % ( |
|
1647 | 1651 | info.name, |
|
1648 | 1652 | info.address, |
|
1649 | 1653 | info.port, |
|
1650 | 1654 | info.type, |
|
1651 | 1655 | ) |
|
1652 | 1656 | self.checkService(info) |
|
1653 | 1657 | return |
|
1654 | 1658 | raise NonUniqueNameException |
|
1655 | 1659 | if now < nexttime: |
|
1656 | 1660 | self.wait(nexttime - now) |
|
1657 | 1661 | now = currentTimeMillis() |
|
1658 | 1662 | continue |
|
1659 | 1663 | out = DNSOutgoing(_FLAGS_QR_QUERY | _FLAGS_AA) |
|
1660 | 1664 | self.debug = out |
|
1661 | 1665 | out.addQuestion(DNSQuestion(info.type, _TYPE_PTR, _CLASS_IN)) |
|
1662 | 1666 | out.addAuthoritativeAnswer( |
|
1663 | 1667 | DNSPointer(info.type, _TYPE_PTR, _CLASS_IN, _DNS_TTL, info.name) |
|
1664 | 1668 | ) |
|
1665 | 1669 | self.send(out) |
|
1666 | 1670 | i += 1 |
|
1667 | 1671 | nexttime += _CHECK_TIME |
|
1668 | 1672 | |
|
1669 | 1673 | def addListener(self, listener, question): |
|
1670 | 1674 | """Adds a listener for a given question. The listener will have |
|
1671 | 1675 | its updateRecord method called when information is available to |
|
1672 | 1676 | answer the question.""" |
|
1673 | 1677 | now = currentTimeMillis() |
|
1674 | 1678 | self.listeners.append(listener) |
|
1675 | 1679 | if question is not None: |
|
1676 | 1680 | for record in self.cache.entriesWithName(question.name): |
|
1677 | 1681 | if question.answeredBy(record) and not record.isExpired(now): |
|
1678 | 1682 | listener.updateRecord(self, now, record) |
|
1679 | 1683 | self.notifyAll() |
|
1680 | 1684 | |
|
1681 | 1685 | def removeListener(self, listener): |
|
1682 | 1686 | """Removes a listener.""" |
|
1683 | 1687 | try: |
|
1684 | 1688 | self.listeners.remove(listener) |
|
1685 | 1689 | self.notifyAll() |
|
1686 | 1690 | except Exception: |
|
1687 | 1691 | pass |
|
1688 | 1692 | |
|
1689 | 1693 | def updateRecord(self, now, rec): |
|
1690 | 1694 | """Used to notify listeners of new information that has updated |
|
1691 | 1695 | a record.""" |
|
1692 | 1696 | for listener in self.listeners: |
|
1693 | 1697 | listener.updateRecord(self, now, rec) |
|
1694 | 1698 | self.notifyAll() |
|
1695 | 1699 | |
|
1696 | 1700 | def handleResponse(self, msg): |
|
1697 | 1701 | """Deal with incoming response packets. All answers |
|
1698 | 1702 | are held in the cache, and listeners are notified.""" |
|
1699 | 1703 | now = currentTimeMillis() |
|
1700 | 1704 | for record in msg.answers: |
|
1701 | 1705 | expired = record.isExpired(now) |
|
1702 | 1706 | if record in self.cache.entries(): |
|
1703 | 1707 | if expired: |
|
1704 | 1708 | self.cache.remove(record) |
|
1705 | 1709 | else: |
|
1706 | 1710 | entry = self.cache.get(record) |
|
1707 | 1711 | if entry is not None: |
|
1708 | 1712 | entry.resetTTL(record) |
|
1709 | 1713 | record = entry |
|
1710 | 1714 | else: |
|
1711 | 1715 | self.cache.add(record) |
|
1712 | 1716 | |
|
1713 | 1717 | self.updateRecord(now, record) |
|
1714 | 1718 | |
|
1715 | 1719 | def handleQuery(self, msg, addr, port): |
|
1716 | 1720 | """Deal with incoming query packets. Provides a response if |
|
1717 | 1721 | possible.""" |
|
1718 | 1722 | out = None |
|
1719 | 1723 | |
|
1720 | 1724 | # Support unicast client responses |
|
1721 | 1725 | # |
|
1722 | 1726 | if port != _MDNS_PORT: |
|
1723 | 1727 | out = DNSOutgoing(_FLAGS_QR_RESPONSE | _FLAGS_AA, 0) |
|
1724 | 1728 | for question in msg.questions: |
|
1725 | 1729 | out.addQuestion(question) |
|
1726 | 1730 | |
|
1727 | 1731 | for question in msg.questions: |
|
1728 | 1732 | if question.type == _TYPE_PTR: |
|
1729 | 1733 | if question.name == b"_services._dns-sd._udp.local.": |
|
1730 | 1734 | for stype in self.servicetypes.keys(): |
|
1731 | 1735 | if out is None: |
|
1732 | 1736 | out = DNSOutgoing(_FLAGS_QR_RESPONSE | _FLAGS_AA) |
|
1733 | 1737 | out.addAnswer( |
|
1734 | 1738 | msg, |
|
1735 | 1739 | DNSPointer( |
|
1736 | 1740 | b"_services._dns-sd._udp.local.", |
|
1737 | 1741 | _TYPE_PTR, |
|
1738 | 1742 | _CLASS_IN, |
|
1739 | 1743 | _DNS_TTL, |
|
1740 | 1744 | stype, |
|
1741 | 1745 | ), |
|
1742 | 1746 | ) |
|
1743 | 1747 | for service in self.services.values(): |
|
1744 | 1748 | if question.name == service.type: |
|
1745 | 1749 | if out is None: |
|
1746 | 1750 | out = DNSOutgoing(_FLAGS_QR_RESPONSE | _FLAGS_AA) |
|
1747 | 1751 | out.addAnswer( |
|
1748 | 1752 | msg, |
|
1749 | 1753 | DNSPointer( |
|
1750 | 1754 | service.type, |
|
1751 | 1755 | _TYPE_PTR, |
|
1752 | 1756 | _CLASS_IN, |
|
1753 | 1757 | _DNS_TTL, |
|
1754 | 1758 | service.name, |
|
1755 | 1759 | ), |
|
1756 | 1760 | ) |
|
1757 | 1761 | else: |
|
1758 | 1762 | try: |
|
1759 | 1763 | if out is None: |
|
1760 | 1764 | out = DNSOutgoing(_FLAGS_QR_RESPONSE | _FLAGS_AA) |
|
1761 | 1765 | |
|
1762 | 1766 | # Answer A record queries for any service addresses we know |
|
1763 | 1767 | if question.type == _TYPE_A or question.type == _TYPE_ANY: |
|
1764 | 1768 | for service in self.services.values(): |
|
1765 | 1769 | if service.server == question.name.lower(): |
|
1766 | 1770 | out.addAnswer( |
|
1767 | 1771 | msg, |
|
1768 | 1772 | DNSAddress( |
|
1769 | 1773 | question.name, |
|
1770 | 1774 | _TYPE_A, |
|
1771 | 1775 | _CLASS_IN | _CLASS_UNIQUE, |
|
1772 | 1776 | _DNS_TTL, |
|
1773 | 1777 | service.address, |
|
1774 | 1778 | ), |
|
1775 | 1779 | ) |
|
1776 | 1780 | |
|
1777 | 1781 | service = self.services.get(question.name.lower(), None) |
|
1778 | 1782 | if not service: |
|
1779 | 1783 | continue |
|
1780 | 1784 | |
|
1781 | 1785 | if question.type == _TYPE_SRV or question.type == _TYPE_ANY: |
|
1782 | 1786 | out.addAnswer( |
|
1783 | 1787 | msg, |
|
1784 | 1788 | DNSService( |
|
1785 | 1789 | question.name, |
|
1786 | 1790 | _TYPE_SRV, |
|
1787 | 1791 | _CLASS_IN | _CLASS_UNIQUE, |
|
1788 | 1792 | _DNS_TTL, |
|
1789 | 1793 | service.priority, |
|
1790 | 1794 | service.weight, |
|
1791 | 1795 | service.port, |
|
1792 | 1796 | service.server, |
|
1793 | 1797 | ), |
|
1794 | 1798 | ) |
|
1795 | 1799 | if question.type == _TYPE_TXT or question.type == _TYPE_ANY: |
|
1796 | 1800 | out.addAnswer( |
|
1797 | 1801 | msg, |
|
1798 | 1802 | DNSText( |
|
1799 | 1803 | question.name, |
|
1800 | 1804 | _TYPE_TXT, |
|
1801 | 1805 | _CLASS_IN | _CLASS_UNIQUE, |
|
1802 | 1806 | _DNS_TTL, |
|
1803 | 1807 | service.text, |
|
1804 | 1808 | ), |
|
1805 | 1809 | ) |
|
1806 | 1810 | if question.type == _TYPE_SRV: |
|
1807 | 1811 | out.addAdditionalAnswer( |
|
1808 | 1812 | DNSAddress( |
|
1809 | 1813 | service.server, |
|
1810 | 1814 | _TYPE_A, |
|
1811 | 1815 | _CLASS_IN | _CLASS_UNIQUE, |
|
1812 | 1816 | _DNS_TTL, |
|
1813 | 1817 | service.address, |
|
1814 | 1818 | ) |
|
1815 | 1819 | ) |
|
1816 | 1820 | except Exception: |
|
1817 | 1821 | traceback.print_exc() |
|
1818 | 1822 | |
|
1819 | 1823 | if out is not None and out.answers: |
|
1820 | 1824 | out.id = msg.id |
|
1821 | 1825 | self.send(out, addr, port) |
|
1822 | 1826 | |
|
1823 | 1827 | def send(self, out, addr=_MDNS_ADDR, port=_MDNS_PORT): |
|
1824 | 1828 | """Sends an outgoing packet.""" |
|
1825 | 1829 | # This is a quick test to see if we can parse the packets we generate |
|
1826 | 1830 | # temp = DNSIncoming(out.packet()) |
|
1827 | 1831 | try: |
|
1828 | 1832 | self.socket.sendto(out.packet(), 0, (addr, port)) |
|
1829 | 1833 | except Exception: |
|
1830 | 1834 | # Ignore this, it may be a temporary loss of network connection |
|
1831 | 1835 | pass |
|
1832 | 1836 | |
|
1833 | 1837 | def close(self): |
|
1834 | 1838 | """Ends the background threads, and prevent this instance from |
|
1835 | 1839 | servicing further queries.""" |
|
1836 | 1840 | if globals()[b'_GLOBAL_DONE'] == 0: |
|
1837 | 1841 | globals()[b'_GLOBAL_DONE'] = 1 |
|
1838 | 1842 | self.notifyAll() |
|
1839 | 1843 | self.engine.notify() |
|
1840 | 1844 | self.unregisterAllServices() |
|
1841 | 1845 | self.socket.setsockopt( |
|
1842 | 1846 | socket.SOL_IP, |
|
1843 | 1847 | socket.IP_DROP_MEMBERSHIP, |
|
1844 | 1848 | socket.inet_aton(_MDNS_ADDR) + socket.inet_aton(r'0.0.0.0'), |
|
1845 | 1849 | ) |
|
1846 | 1850 | self.socket.close() |
|
1847 | 1851 | |
|
1848 | 1852 | |
|
1849 | 1853 | # Test a few module features, including service registration, service |
|
1850 | 1854 | # query (for Zoe), and service unregistration. |
|
1851 | 1855 | |
|
1852 | 1856 | if __name__ == '__main__': |
|
1853 | 1857 | print(b"Multicast DNS Service Discovery for Python, version", __version__) |
|
1854 | 1858 | r = Zeroconf() |
|
1855 | 1859 | print(b"1. Testing registration of a service...") |
|
1856 | 1860 | desc = {b'version': b'0.10', b'a': b'test value', b'b': b'another value'} |
|
1857 | 1861 | info = ServiceInfo( |
|
1858 | 1862 | b"_http._tcp.local.", |
|
1859 | 1863 | b"My Service Name._http._tcp.local.", |
|
1860 | 1864 | socket.inet_aton(b"127.0.0.1"), |
|
1861 | 1865 | 1234, |
|
1862 | 1866 | 0, |
|
1863 | 1867 | 0, |
|
1864 | 1868 | desc, |
|
1865 | 1869 | ) |
|
1866 | 1870 | print(b" Registering service...") |
|
1867 | 1871 | r.registerService(info) |
|
1868 | 1872 | print(b" Registration done.") |
|
1869 | 1873 | print(b"2. Testing query of service information...") |
|
1870 | 1874 | print( |
|
1871 | 1875 | b" Getting ZOE service:", |
|
1872 | 1876 | str(r.getServiceInfo(b"_http._tcp.local.", b"ZOE._http._tcp.local.")), |
|
1873 | 1877 | ) |
|
1874 | 1878 | print(b" Query done.") |
|
1875 | 1879 | print(b"3. Testing query of own service...") |
|
1876 | 1880 | print( |
|
1877 | 1881 | b" Getting self:", |
|
1878 | 1882 | str( |
|
1879 | 1883 | r.getServiceInfo( |
|
1880 | 1884 | b"_http._tcp.local.", b"My Service Name._http._tcp.local." |
|
1881 | 1885 | ) |
|
1882 | 1886 | ), |
|
1883 | 1887 | ) |
|
1884 | 1888 | print(b" Query done.") |
|
1885 | 1889 | print(b"4. Testing unregister of service information...") |
|
1886 | 1890 | r.unregisterService(info) |
|
1887 | 1891 | print(b" Unregister done.") |
|
1888 | 1892 | r.close() |
General Comments 0
You need to be logged in to leave comments.
Login now