pybonjour.py 62.3 KB
Newer Older
Wim Haanstra's avatar
Wim Haanstra committed
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
################################################################################
#
# Copyright (c) 2007-2008 Christopher J. Stawarz
#
# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation files
# (the "Software"), to deal in the Software without restriction,
# including without limitation the rights to use, copy, modify, merge,
# publish, distribute, sublicense, and/or sell copies of the Software,
# and to permit persons to whom the Software is furnished to do so,
# subject to the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
#
################################################################################



"""

Pure-Python interface to Apple Bonjour and compatible DNS-SD libraries

pybonjour provides a pure-Python interface (via ctypes) to Apple
Bonjour and compatible DNS-SD libraries (such as Avahi).  It allows
Python scripts to take advantage of Zero Configuration Networking
(Zeroconf) to register, discover, and resolve services on both local
and wide-area networks.  Since pybonjour is implemented in pure
Python, scripts that use it can easily be ported to Mac OS X, Windows,
Linux, and other systems that run Bonjour.

Note on strings: Internally, all strings used in DNS-SD are UTF-8
strings.  String arguments passed to the DNS-SD functions provided by
pybonjour must be either unicode instances or str instances that can
be converted to unicode using the default encoding.  (Passing a
non-convertible str will result in an exception.)  Strings returned
from pybonjour (either directly from API functions or passed to
application callbacks) are always unicode instances.

"""


__author__   = 'Christopher Stawarz <cstawarz@csail.mit.edu>'
__version__  = '1.1.1'
__revision__ = int('$Revision: 6125 $'.split()[1])


import ctypes
import os
import re
import socket
import sys



################################################################################
#
# Global setup
#
################################################################################



class _DummyLock(object):

    @staticmethod
    def acquire():
        pass

    @staticmethod
    def release():
        pass

_global_lock = _DummyLock()


if sys.platform == 'win32':
    # Need to use the stdcall variants
    _libdnssd = ctypes.windll.dnssd
    _CFunc = ctypes.WINFUNCTYPE
else:
    if sys.platform == 'darwin':
        _libdnssd = 'libSystem.B.dylib'
    else:
        _libdnssd = 'libdns_sd.so.1'

        # If libdns_sd is actually Avahi's Bonjour compatibility
        # layer, silence its annoying warning messages, and use a real
        # RLock as the global lock, since the compatibility layer
        # isn't thread safe.
        try:
            ctypes.cdll.LoadLibrary('libavahi-client.so.3')
        except OSError:
            pass
        else:
            os.environ['AVAHI_COMPAT_NOWARN'] = '1'
            import threading
            _global_lock = threading.RLock()

    _libdnssd = ctypes.cdll.LoadLibrary(_libdnssd)
    _CFunc = ctypes.CFUNCTYPE



################################################################################
#
# Constants
#
################################################################################



#
# General flags
#

kDNSServiceFlagsMoreComing          = 0x1
kDNSServiceFlagsAdd                 = 0x2
kDNSServiceFlagsDefault             = 0x4
kDNSServiceFlagsNoAutoRename        = 0x8
kDNSServiceFlagsShared              = 0x10
kDNSServiceFlagsUnique              = 0x20
kDNSServiceFlagsBrowseDomains       = 0x40
kDNSServiceFlagsRegistrationDomains = 0x80
kDNSServiceFlagsLongLivedQuery      = 0x100
kDNSServiceFlagsAllowRemoteQuery    = 0x200
kDNSServiceFlagsForceMulticast      = 0x400
kDNSServiceFlagsReturnCNAME         = 0x800


#
# Service classes
#

kDNSServiceClass_IN                 = 1


#
# Service types
#

kDNSServiceType_A                   = 1
kDNSServiceType_NS                  = 2
kDNSServiceType_MD                  = 3
kDNSServiceType_MF                  = 4
kDNSServiceType_CNAME               = 5
kDNSServiceType_SOA                 = 6
kDNSServiceType_MB                  = 7
kDNSServiceType_MG                  = 8
kDNSServiceType_MR                  = 9
kDNSServiceType_NULL                = 10
kDNSServiceType_WKS                 = 11
kDNSServiceType_PTR                 = 12
kDNSServiceType_HINFO               = 13
kDNSServiceType_MINFO               = 14
kDNSServiceType_MX                  = 15
kDNSServiceType_TXT                 = 16
kDNSServiceType_RP                  = 17
kDNSServiceType_AFSDB               = 18
kDNSServiceType_X25                 = 19
kDNSServiceType_ISDN                = 20
kDNSServiceType_RT                  = 21
kDNSServiceType_NSAP                = 22
kDNSServiceType_NSAP_PTR            = 23
kDNSServiceType_SIG                 = 24
kDNSServiceType_KEY                 = 25
kDNSServiceType_PX                  = 26
kDNSServiceType_GPOS                = 27
kDNSServiceType_AAAA                = 28
kDNSServiceType_LOC                 = 29
kDNSServiceType_NXT                 = 30
kDNSServiceType_EID                 = 31
kDNSServiceType_NIMLOC              = 32
kDNSServiceType_SRV                 = 33
kDNSServiceType_ATMA                = 34
kDNSServiceType_NAPTR               = 35
kDNSServiceType_KX                  = 36
kDNSServiceType_CERT                = 37
kDNSServiceType_A6                  = 38
kDNSServiceType_DNAME               = 39
kDNSServiceType_SINK                = 40
kDNSServiceType_OPT                 = 41
kDNSServiceType_TKEY                = 249
kDNSServiceType_TSIG                = 250
kDNSServiceType_IXFR                = 251
kDNSServiceType_AXFR                = 252
kDNSServiceType_MAILB               = 253
kDNSServiceType_MAILA               = 254
kDNSServiceType_ANY                 = 255


#
# Error codes
#

kDNSServiceErr_NoError              = 0
kDNSServiceErr_Unknown              = -65537
kDNSServiceErr_NoSuchName           = -65538
kDNSServiceErr_NoMemory             = -65539
kDNSServiceErr_BadParam             = -65540
kDNSServiceErr_BadReference         = -65541
kDNSServiceErr_BadState             = -65542
kDNSServiceErr_BadFlags             = -65543
kDNSServiceErr_Unsupported          = -65544
kDNSServiceErr_NotInitialized       = -65545
kDNSServiceErr_AlreadyRegistered    = -65547
kDNSServiceErr_NameConflict         = -65548
kDNSServiceErr_Invalid              = -65549
kDNSServiceErr_Firewall             = -65550
kDNSServiceErr_Incompatible         = -65551
kDNSServiceErr_BadInterfaceIndex    = -65552
kDNSServiceErr_Refused              = -65553
kDNSServiceErr_NoSuchRecord         = -65554
kDNSServiceErr_NoAuth               = -65555
kDNSServiceErr_NoSuchKey            = -65556
kDNSServiceErr_NATTraversal         = -65557
kDNSServiceErr_DoubleNAT            = -65558
kDNSServiceErr_BadTime              = -65559
228
kDNSServiceErr_ServiceNotRunning    = -65563
Wim Haanstra's avatar
Wim Haanstra committed
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855


#
# Other constants
#

kDNSServiceMaxServiceName           = 64
kDNSServiceMaxDomainName            = 1005
kDNSServiceInterfaceIndexAny        = 0
kDNSServiceInterfaceIndexLocalOnly  = -1



################################################################################
#
# Error handling
#
################################################################################



class BonjourError(Exception):

    """

    Exception representing an error returned by the DNS-SD library.
    The errorCode attribute contains the actual integer error code
    returned.

    """

    _errmsg = {
        kDNSServiceErr_NoSuchName:		'no such name',
        kDNSServiceErr_NoMemory:		'no memory',
        kDNSServiceErr_BadParam:		'bad param',
        kDNSServiceErr_BadReference:		'bad reference',
        kDNSServiceErr_BadState:		'bad state',
        kDNSServiceErr_BadFlags:		'bad flags',
        kDNSServiceErr_Unsupported:		'unsupported',
        kDNSServiceErr_NotInitialized:		'not initialized',
        kDNSServiceErr_AlreadyRegistered:	'already registered',
        kDNSServiceErr_NameConflict:		'name conflict',
        kDNSServiceErr_Invalid:			'invalid',
        kDNSServiceErr_Firewall:		'firewall',
        kDNSServiceErr_Incompatible:		'incompatible',
        kDNSServiceErr_BadInterfaceIndex:	'bad interface index',
        kDNSServiceErr_Refused:			'refused',
        kDNSServiceErr_NoSuchRecord:		'no such record',
        kDNSServiceErr_NoAuth:			'no auth',
        kDNSServiceErr_NoSuchKey:		'no such key',
        kDNSServiceErr_NATTraversal:		'NAT traversal',
        kDNSServiceErr_DoubleNAT:		'double NAT',
        kDNSServiceErr_BadTime:			'bad time',
        }

    @classmethod
    def _errcheck(cls, result, func, args):
        if result != kDNSServiceErr_NoError:
            raise cls(result)
        return args

    def __init__(self, errorCode):
        self.errorCode = errorCode
        Exception.__init__(self,
                           (errorCode, self._errmsg.get(errorCode, 'unknown')))



################################################################################
#
# Data types
#
################################################################################



class _utf8_char_p(ctypes.c_char_p):

    @classmethod
    def from_param(cls, obj):
        if (obj is not None) and (not isinstance(obj, cls)):
            if not str(obj):
                raise TypeError('parameter must be a string type instance')

            obj = obj.encode('utf-8')
        return ctypes.c_char_p.from_param(obj)

    def decode(self):
        if self.value is None:
            return None
        return self.value.decode('utf-8')


class _utf8_char_p_non_null(_utf8_char_p):

    @classmethod
    def from_param(cls, obj):
        if obj is None:
            raise ValueError('parameter cannot be None')
        return _utf8_char_p.from_param(obj)


_DNSServiceFlags     = ctypes.c_uint32
_DNSServiceErrorType = ctypes.c_int32


class DNSRecordRef(ctypes.c_void_p):

    """

    A DNSRecordRef pointer.  DO NOT CREATE INSTANCES OF THIS CLASS!
    Only instances returned by the DNS-SD library are valid.  Using
    others will likely cause the Python interpreter to crash.

    Application code should not use any of the methods of this class.
    The only valid use of a DNSRecordRef instance is as an argument to
    a DNS-SD function.

    To compare two DNSRecordRef instances for equality, use '=='
    rather than 'is'.

    """

    @classmethod
    def from_param(cls, obj):
        if type(obj) is not cls:
            raise TypeError("expected '%s', got '%s'" %
                            (cls.__name__, type(obj).__name__))
        if obj.value is None:
            raise ValueError('invalid %s instance' % cls.__name__)
        return obj

    def __eq__(self, other):
        return ((type(other) is type(self)) and	(other.value == self.value))

    def __ne__(self, other):
        return not (other == self)

    def _invalidate(self):
        self.value = None

    def _valid(self):
        return (self.value is not None)


class _DNSRecordRef_or_null(DNSRecordRef):

    @classmethod
    def from_param(cls, obj):
        if obj is None:
            return obj
        return DNSRecordRef.from_param(obj)


class DNSServiceRef(DNSRecordRef):

    """

    A DNSServiceRef pointer.  DO NOT CREATE INSTANCES OF THIS CLASS!
    Only instances returned by the DNS-SD library are valid.  Using
    others will likely cause the Python interpreter to crash.

    An instance of this class represents an active connection to the
    mDNS daemon.  The connection remains open until the close() method
    is called (which also terminates the associated browse, resolve,
    etc.).  Note that this method is *not* called automatically when
    the instance is deallocated; therefore, application code must be
    certain to call close() when the connection is no longer needed.

    The primary use of a DNSServiceRef instance is in conjunction with
    select() or poll() to determine when a response from the daemon is
    available.  When the file descriptor returned by fileno() is ready
    for reading, a reply from the daemon is available and should be
    processed by passing the DNSServiceRef instance to
    DNSServiceProcessResult(), which will invoke the appropriate
    application callback function.  (Note that the file descriptor
    should never be read from or written to directly.)

    The DNSServiceRef class supports the context management protocol
    introduced in Python 2.5, meaning applications can use the 'with'
    statement to ensure that DNSServiceRef instances are closed
    regardless of whether an exception occurs, e.g.

      sdRef = DNSServiceBrowse(...)
      with sdRef:
          # sdRef will be closed regardless of how this block is
          # exited
          ...

    To compare two DNSServiceRef instances for equality, use '=='
    rather than 'is'.

    """

    def __init__(self, *args, **kwargs):
        DNSRecordRef.__init__(self, *args, **kwargs)

        # Since callback functions are called asynchronously, we need
        # to hold onto references to them for as long as they're in
        # use.  Otherwise, Python could deallocate them before we call
        # DNSServiceProcessResult(), meaning the Bonjour library would
        # dereference freed memory when it tried to invoke the
        # callback.
        self._callbacks = []

        # A DNSRecordRef is invalidated if DNSServiceRefDeallocate()
        # is called on the corresponding DNSServiceRef, so we need to
        # keep track of all our record refs and invalidate them when
        # we're closed.
        self._record_refs = []

    def __enter__(self):
        return self

    def __exit__(self, type, value, traceback):
        self.close()

    def _add_callback(self, cb):
        self._callbacks.append(cb)

    def _add_record_ref(self, ref):
        self._record_refs.append(ref)

    def close(self):
        """

        Close the connection to the mDNS daemon and terminate any
        associated browse, resolve, etc. operations.

        """

        if self._valid():
            for ref in self._record_refs:
                ref._invalidate()
            del self._record_refs

            _global_lock.acquire()
            try:
                _DNSServiceRefDeallocate(self)
            finally:
                _global_lock.release()

            self._invalidate()
            del self._callbacks

    def fileno(self):
        """

        Return the file descriptor associated with this connection.
        This descriptor should never be read from or written to
        directly.  It should only be passed to select() or poll() to
        determine when a response from the mDNS daemon is available.

        """

        _global_lock.acquire()
        try:
            fd = _DNSServiceRefSockFD(self)
        finally:
            _global_lock.release()

        return fd


_DNSServiceDomainEnumReply = _CFunc(
    None,
    DNSServiceRef,		# sdRef
    _DNSServiceFlags,		# flags
    ctypes.c_uint32,		# interfaceIndex
    _DNSServiceErrorType,	# errorCode
    _utf8_char_p,		# replyDomain
    ctypes.c_void_p,		# context
    )


_DNSServiceRegisterReply = _CFunc(
    None,
    DNSServiceRef,		# sdRef
    _DNSServiceFlags,		# flags
    _DNSServiceErrorType,	# errorCode
    _utf8_char_p,		# name
    _utf8_char_p,		# regtype
    _utf8_char_p,		# domain
    ctypes.c_void_p,		# context
    )


_DNSServiceBrowseReply = _CFunc(
    None,
    DNSServiceRef,		# sdRef
    _DNSServiceFlags,		# flags
    ctypes.c_uint32,		# interfaceIndex
    _DNSServiceErrorType,	# errorCode
    _utf8_char_p,		# serviceName
    _utf8_char_p,		# regtype
    _utf8_char_p,		# replyDomain
    ctypes.c_void_p,		# context
    )


_DNSServiceResolveReply = _CFunc(
    None,
    DNSServiceRef,		# sdRef
    _DNSServiceFlags,		# flags
    ctypes.c_uint32,		# interfaceIndex
    _DNSServiceErrorType,	# errorCode
    _utf8_char_p,		# fullname
    _utf8_char_p,		# hosttarget
    ctypes.c_uint16,		# port
    ctypes.c_uint16,		# txtLen
    ctypes.c_void_p,		# txtRecord (not null-terminated, so c_void_p)
    ctypes.c_void_p,		# context
    )


_DNSServiceRegisterRecordReply = _CFunc(
    None,
    DNSServiceRef,		# sdRef
    DNSRecordRef,		# RecordRef
    _DNSServiceFlags,		# flags
    _DNSServiceErrorType,	# errorCode
    ctypes.c_void_p,		# context
    )


_DNSServiceQueryRecordReply = _CFunc(
    None,
    DNSServiceRef,		# sdRef
    _DNSServiceFlags,		# flags
    ctypes.c_uint32,		# interfaceIndex
    _DNSServiceErrorType,	# errorCode
    _utf8_char_p,		# fullname
    ctypes.c_uint16,		# rrtype
    ctypes.c_uint16,		# rrclass
    ctypes.c_uint16,		# rdlen
    ctypes.c_void_p,		# rdata
    ctypes.c_uint32,		# ttl
    ctypes.c_void_p,		# context
    )



################################################################################
#
# Low-level function bindings
#
################################################################################



def _create_function_bindings():

    ERRCHECK    = True
    NO_ERRCHECK = False

    OUTPARAM    = (lambda index: index)
    NO_OUTPARAM = None

    specs = {

        #'funcname':
        #(
        #    return_type,
        #    errcheck,
        #    outparam,
        #    (
        #	param_1_type,
        #	param_2_type,
        #	...
        #	param_n_type,
        #	)),

        'DNSServiceRefSockFD':
        (
            ctypes.c_int,
            NO_ERRCHECK,
            NO_OUTPARAM,
            (
                DNSServiceRef,			# sdRef
                )),

        'DNSServiceProcessResult':
        (
            _DNSServiceErrorType,
            ERRCHECK,
            NO_OUTPARAM,
            (
                DNSServiceRef,			# sdRef
                )),

        'DNSServiceRefDeallocate':
        (
            None,
            NO_ERRCHECK,
            NO_OUTPARAM,
            (
                DNSServiceRef,			# sdRef
                )),

        'DNSServiceEnumerateDomains':
        (
            _DNSServiceErrorType,
            ERRCHECK,
            OUTPARAM(0),
            (
                ctypes.POINTER(DNSServiceRef),	# sdRef
                _DNSServiceFlags,		# flags
                ctypes.c_uint32,		# interfaceIndex
                _DNSServiceDomainEnumReply,	# callBack
                ctypes.c_void_p,		# context
                )),

        'DNSServiceRegister':
        (
            _DNSServiceErrorType,
            ERRCHECK,
            OUTPARAM(0),
            (
                ctypes.POINTER(DNSServiceRef),	# sdRef
                _DNSServiceFlags,		# flags
                ctypes.c_uint32,		# interfaceIndex
                _utf8_char_p,			# name
                _utf8_char_p_non_null,		# regtype
                _utf8_char_p,			# domain
                _utf8_char_p,			# host
                ctypes.c_uint16,		# port
                ctypes.c_uint16,		# txtLen
                ctypes.c_void_p,		# txtRecord
                _DNSServiceRegisterReply,	# callBack
                ctypes.c_void_p,		# context
                )),

        'DNSServiceAddRecord':
        (
            _DNSServiceErrorType,
            ERRCHECK,
            OUTPARAM(1),
            (
                DNSServiceRef,			# sdRef
                ctypes.POINTER(DNSRecordRef),	# RecordRef
                _DNSServiceFlags,		# flags
                ctypes.c_uint16,		# rrtype
                ctypes.c_uint16,		# rdlen
                ctypes.c_void_p,		# rdata
                ctypes.c_uint32,		# ttl
                )),

        'DNSServiceUpdateRecord':
        (
            _DNSServiceErrorType,
            ERRCHECK,
            NO_OUTPARAM,
            (
                DNSServiceRef,			# sdRef
                _DNSRecordRef_or_null,		# RecordRef
                _DNSServiceFlags,		# flags
                ctypes.c_uint16,		# rdlen
                ctypes.c_void_p,		# rdata
                ctypes.c_uint32,		# ttl
                )),

        'DNSServiceRemoveRecord':
        (
            _DNSServiceErrorType,
            ERRCHECK,
            NO_OUTPARAM,
            (
                DNSServiceRef,			# sdRef
                DNSRecordRef,			# RecordRef
                _DNSServiceFlags,		# flags
                )),

        'DNSServiceBrowse':
        (
            _DNSServiceErrorType,
            ERRCHECK,
            OUTPARAM(0),
            (
                ctypes.POINTER(DNSServiceRef),	# sdRef
                _DNSServiceFlags,		# flags
                ctypes.c_uint32,		# interfaceIndex
                _utf8_char_p_non_null,		# regtype
                _utf8_char_p,			# domain
                _DNSServiceBrowseReply,		# callBack
                ctypes.c_void_p,		# context
                )),

        'DNSServiceResolve':
        (
            _DNSServiceErrorType,
            ERRCHECK,
            OUTPARAM(0),
            (
                ctypes.POINTER(DNSServiceRef),	# sdRef
                _DNSServiceFlags,		# flags
                ctypes.c_uint32,		# interfaceIndex
                _utf8_char_p_non_null,		# name
                _utf8_char_p_non_null,		# regtype
                _utf8_char_p_non_null,		# domain
                _DNSServiceResolveReply,	# callBack
                ctypes.c_void_p,		# context
                )),

        'DNSServiceCreateConnection':
        (
            _DNSServiceErrorType,
            ERRCHECK,
            OUTPARAM(0),
            (
                ctypes.POINTER(DNSServiceRef),	# sdRef
                )),

        'DNSServiceRegisterRecord':
        (
            _DNSServiceErrorType,
            ERRCHECK,
            OUTPARAM(1),
            (
                DNSServiceRef,			# sdRef
                ctypes.POINTER(DNSRecordRef),	# RecordRef
                _DNSServiceFlags,		# flags
                ctypes.c_uint32,		# interfaceIndex
                _utf8_char_p_non_null,		# fullname
                ctypes.c_uint16,		# rrtype
                ctypes.c_uint16,		# rrclass
                ctypes.c_uint16,		# rdlen
                ctypes.c_void_p,		# rdata
                ctypes.c_uint32,		# ttl
                _DNSServiceRegisterRecordReply,	# callBack
                ctypes.c_void_p,		# context
                )),

        'DNSServiceQueryRecord':
        (
            _DNSServiceErrorType,
            ERRCHECK,
            OUTPARAM(0),
            (
                ctypes.POINTER(DNSServiceRef),	# sdRef
                _DNSServiceFlags,		# flags
                ctypes.c_uint32,		# interfaceIndex
                _utf8_char_p_non_null,		# fullname
                ctypes.c_uint16,		# rrtype
                ctypes.c_uint16,		# rrclass
                _DNSServiceQueryRecordReply,	# callBack
                ctypes.c_void_p,		# context
                )),

        'DNSServiceReconfirmRecord':
        (
            None,		# _DNSServiceErrorType in more recent versions
            NO_ERRCHECK,
            NO_OUTPARAM,
            (
                _DNSServiceFlags,		# flags
                ctypes.c_uint32,		# interfaceIndex
                _utf8_char_p_non_null,		# fullname
                ctypes.c_uint16,		# rrtype
                ctypes.c_uint16,		# rrclass
                ctypes.c_uint16,		# rdlen
                ctypes.c_void_p,		# rdata
                )),

        'DNSServiceConstructFullName':
        (
            ctypes.c_int,
            ERRCHECK,
            OUTPARAM(0),
            (
                ctypes.c_char * kDNSServiceMaxDomainName,	# fullName
                _utf8_char_p,					# service
                _utf8_char_p_non_null,				# regtype
                _utf8_char_p_non_null,				# domain
                )),

        }


    for name, (restype, errcheck, outparam, argtypes) in specs.items():
        prototype = _CFunc(restype, *argtypes)

        paramflags = [1] * len(argtypes)
        if outparam is not None:
            paramflags[outparam] = 2
        paramflags = tuple((val,) for val in paramflags)

        func = prototype((name, _libdnssd), paramflags)

        if errcheck:
            func.errcheck = BonjourError._errcheck

        globals()['_' + name] = func


# Only need to do this once
_create_function_bindings()
del _create_function_bindings



################################################################################
#
# Internal utility types and functions
#
################################################################################



class _NoDefault(object):

    def __repr__(self):
        return '<NO DEFAULT>'

    def check(self, obj):
        if obj is self:
            raise ValueError('required parameter value missing')

_NO_DEFAULT = _NoDefault()


def _string_to_length_and_void_p(string):
    if isinstance(string, TXTRecord):
        string = str(string)
    void_p = ctypes.cast(ctypes.c_char_p(string), ctypes.c_void_p)
    return len(string), void_p


856
def _length_and_void_p_to_byte(length, void_p):
Wim Haanstra's avatar
Wim Haanstra committed
857
    char_p = ctypes.cast(void_p, ctypes.POINTER(ctypes.c_char))
858
    return b''.join(char_p[i] for i in range(length))
Wim Haanstra's avatar
Wim Haanstra committed
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108



################################################################################
#
# High-level functions
#
################################################################################



def DNSServiceProcessResult(
    sdRef,
    ):

    """

    Read a reply from the daemon, calling the appropriate application
    callback.  This call will block until the daemon's response is
    received.  Use sdRef in conjunction with select() or poll() to
    determine the presence of a response from the server before
    calling this function to process the reply without blocking.  Call
    this function at any point if it is acceptable to block until the
    daemon's response arrives.  Note that the client is responsible
    for ensuring that DNSServiceProcessResult() is called whenever
    there is a reply from the daemon; the daemon may terminate its
    connection with a client that does not process the daemon's
    responses.

      sdRef:
        A DNSServiceRef returned by any of the DNSService calls that
        take a callback parameter.

    """

    _global_lock.acquire()
    try:
        _DNSServiceProcessResult(sdRef)
    finally:
        _global_lock.release()


def DNSServiceEnumerateDomains(
    flags,
    interfaceIndex = kDNSServiceInterfaceIndexAny,
    callBack = None,
    ):

    """

    Asynchronously enumerate domains available for browsing and
    registration.

    The enumeration MUST be cancelled by closing the returned
    DNSServiceRef when no more domains are to be found.

      flags:
        Possible values are:
          kDNSServiceFlagsBrowseDomains to enumerate domains
          recommended for browsing.
          kDNSServiceFlagsRegistrationDomains to enumerate domains
          recommended for registration.

      interfaceIndex:
        If non-zero, specifies the interface on which to look for
        domains.  Most applications will pass
        kDNSServiceInterfaceIndexAny (0) to enumerate domains on all
        interfaces.

      callBack:
        The function to be called when a domain is found or the call
        asynchronously fails.  Its signature should be
        callBack(sdRef,	flags, interfaceIndex, errorCode, replyDomain).

      return value:
        A DNSServiceRef instance.

    Callback Parameters:

      sdRef:
        The DNSServiceRef returned by DNSServiceEnumerateDomains().

      flags:
        Possible values are:
          kDNSServiceFlagsMoreComing
          kDNSServiceFlagsAdd
          kDNSServiceFlagsDefault

      interfaceIndex:
        Specifies the interface on which the domain exists.

      errorCode:
        Will be kDNSServiceErr_NoError (0) on success, otherwise
        indicates the failure that occurred (in which case other
        parameters are undefined).

      replyDomain:
        The name of the domain.

    """

    @_DNSServiceDomainEnumReply
    def _callback(sdRef, flags, interfaceIndex, errorCode, replyDomain,
                  context):
        if callBack is not None:
            callBack(sdRef, flags, interfaceIndex, errorCode,
                     replyDomain.decode())

    _global_lock.acquire()
    try:
        sdRef = _DNSServiceEnumerateDomains(flags,
                                            interfaceIndex,
                                            _callback,
                                            None)
    finally:
        _global_lock.release()

    sdRef._add_callback(_callback)

    return sdRef


def DNSServiceRegister(
    flags = 0,
    interfaceIndex = kDNSServiceInterfaceIndexAny,
    name = None,
    regtype = _NO_DEFAULT,
    domain = None,
    host = None,
    port = _NO_DEFAULT,
    txtRecord = '',
    callBack = None,
    ):

    """

    Register a service that is discovered via DNSServiceBrowse() and
    DNSServiceResolve() calls.

      flags:
        Indicates the renaming behavior on name conflict.  Most
        applications will pass 0.

      interfaceIndex:
        If non-zero, specifies the interface on which to register the
        service.  Most applications will pass
        kDNSServiceInterfaceIndexAny (0) to register on all available
        interfaces.

      name:
        If not None, specifies the service name to be registered.
        Most applications will not specify a name, in which case the
        computer name is used.  (This name is communicated to the
        client via the callback.)  If a name is specified, it must be
        1-63 bytes of UTF-8 text.  If the name is longer than 63
        bytes, it will be automatically truncated to a legal length,
        unless the flag kDNSServiceFlagsNoAutoRename is set, in which
        case a BonjourError exception will be thrown.

      regtype:
        The service type followed by the protocol, separated by a dot
        (e.g. "_ftp._tcp"). The service type must be an underscore,
        followed by 1-14 characters, which may be letters, digits, or
        hyphens.  The transport protocol must be "_tcp" or "_udp". New
        service types should be registered at
        <http://www.dns-sd.org/ServiceTypes.html>.

      domain:
        If not None, specifies the domain on which to advertise the
        service.  Most applications will not specify a domain, instead
        automatically registering in the default domain(s).

      host:
        If not None, specifies the SRV target host name.  Most
        applications will not specify a host, instead automatically
        using the machine's default host name(s).  Note that
        specifying a host name does NOT create an address record for
        that host; the application is responsible for ensuring that
        the appropriate address record exists, or creating it via
        DNSServiceRegisterRecord().

      port:
        The port, in host (not network) byte order, on which the
        service accepts connections.  Pass 0 for a "placeholder"
        service (i.e. a service that will not be discovered by
        browsing, but will cause a name conflict if another client
        tries to register that same name).  Most clients will not use
        placeholder services.

      txtRecord:
        The TXT record rdata.  If not None, txtRecord must be either a
        TXTRecord instance or a string containing a properly formatted
        DNS TXT record, i.e.
        <length byte> <data> <length byte> <data> ...

      callBack:
        The function to be called when the registration completes or
        asynchronously fails.  Its signature should be
        callBack(sdRef, flags, errorCode, name, regtype, domain).
        The client MAY pass None for the callback, in which case the
        client will NOT be notified of the default values picked on
        its behalf, and the client will NOT be notified of any
        asynchronous errors (e.g. out of memory errors, etc.) that may
        prevent the registration of the service.  The client may NOT
        pass the flag kDNSServiceFlagsNoAutoRename if the callback is
        None.  The client may still deregister the service at any time
        by closing the returned DNSServiceRef.

      return value:
        A DNSServiceRef instance.  The registration will remain active
        indefinitely until the client terminates it by closing the
        DNSServiceRef.

    Callback Parameters:

      sdRef:
        The DNSServiceRef returned by DNSServiceRegister().

      flags:
        Currently unused, reserved for future use.

      errorCode:
        Will be kDNSServiceErr_NoError on success, otherwise will
        indicate the failure that occurred (including name conflicts,
        if the kDNSServiceFlagsNoAutoRename flag was used when
        registering).  Other parameters are undefined if an error
        occurred.

      name:
        The service name registered.  (If the application did not
        specify a name in DNSServiceRegister(), this indicates what
        name was automatically chosen.)

      regtype:
        The type of service registered, as it was passed to the
        callout.

      domain:
        The domain on which the service was registered.  (If the
        application did not specify a domain in DNSServiceRegister(),
        this indicates the default domain on which the service was
        registered.)

    """

    _NO_DEFAULT.check(regtype)
    _NO_DEFAULT.check(port)

    port = socket.htons(port)

1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
    # From here on txtRecord has to be a bytes type, so convert what
    # we have:
    if type(txtRecord) == TXTRecord:
        txtRecord = str(txtRecord).encode('utf-8')
    elif type(txtRecord) == str:
        txtRecord = txtRecord.encode('utf-8')
    else:
        raise TypeError('txtRecord is unhandlable type: {type}'.format(
            type=type(txtRecord)))

Wim Haanstra's avatar
Wim Haanstra committed
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
    if not txtRecord:
        txtLen, txtRecord = 1, '\0'
    else:
        txtLen, txtRecord = _string_to_length_and_void_p(txtRecord)

    @_DNSServiceRegisterReply
    def _callback(sdRef, flags, errorCode, name, regtype, domain, context):
        if callBack is not None:
            callBack(sdRef, flags, errorCode, name.decode(), regtype.decode(),
                     domain.decode())

    _global_lock.acquire()
    try:
        sdRef = _DNSServiceRegister(flags,
                                    interfaceIndex,
                                    name,
                                    regtype,
                                    domain,
                                    host,
                                    port,
                                    txtLen,
                                    txtRecord,
                                    _callback,
                                    None)
    finally:
        _global_lock.release()

    sdRef._add_callback(_callback)

    return sdRef


def DNSServiceAddRecord(
    sdRef,
    flags = 0,
    rrtype = _NO_DEFAULT,
    rdata = _NO_DEFAULT,
    ttl = 0,
    ):

    """

    Add a record to a registered service.  The name of the record will
    be the same as the registered service's name.  The record can
    later be updated or deregistered by passing the DNSRecordRef
    returned by this function to DNSServiceUpdateRecord() or
    DNSServiceRemoveRecord().

    Note that DNSServiceAddRecord/UpdateRecord/RemoveRecord are NOT
    thread-safe with respect to a single DNSServiceRef.  If you plan
    to have multiple threads in your program simultaneously add,
    update, or remove records from the same DNSServiceRef, then it's
    the caller's responsibility to use a lock or take similar
    appropriate precautions to serialize those calls.

      sdRef:
        A DNSServiceRef returned by DNSServiceRegister().

      flags:
        Currently ignored, reserved for future use.

      rrtype:
        The type of the record (e.g. kDNSServiceType_TXT,
        kDNSServiceType_SRV, etc.).

      rdata:
        A string containing the raw rdata to be contained in the added
        resource record.

      ttl:
        The time to live of the resource record, in seconds.  Pass 0
        to use a default value.

      return value:
        A DNSRecordRef instance, which may be passed to
        DNSServiceUpdateRecord() or DNSServiceRemoveRecord().  If
        sdRef is closed, the DNSRecordRef is also invalidated and may
        not be used further.

    """

    _NO_DEFAULT.check(rrtype)
    _NO_DEFAULT.check(rdata)

    rdlen, rdata = _string_to_length_and_void_p(rdata)

    _global_lock.acquire()
    try:
        RecordRef = _DNSServiceAddRecord(sdRef,
                                         flags,
                                         rrtype,
                                         rdlen,
                                         rdata,
                                         ttl)
    finally:
        _global_lock.release()

    sdRef._add_record_ref(RecordRef)

    return RecordRef


def DNSServiceUpdateRecord(
    sdRef,
    RecordRef = None,
    flags = 0,
    rdata = _NO_DEFAULT,
    ttl = 0,
    ):

    """

    Update a registered resource record.  The record must either be:
      - The primary txt record of a service registered via
        DNSServiceRegister(), or
      - A record added to a registered service via
        DNSServiceAddRecord(), or
      - An individual record registered by DNSServiceRegisterRecord()

      sdRef:
        A DNSServiceRef returned by DNSServiceRegister() or
        DNSServiceCreateConnection().

      RecordRef:
        A DNSRecordRef returned by DNSServiceAddRecord(), or None to
        update the service's primary txt record.

      flags:
        Currently ignored, reserved for future use.

      rdata:
        A string containing the new rdata to be contained in the
        updated resource record.

      ttl:
        The time to live of the updated resource record, in seconds.

    """

    _NO_DEFAULT.check(rdata)

    rdlen, rdata = _string_to_length_and_void_p(rdata)

    _global_lock.acquire()
    try:
        _DNSServiceUpdateRecord(sdRef,
                                RecordRef,
                                flags,
                                rdlen,
                                rdata,
                                ttl)
    finally:
        _global_lock.release()


def DNSServiceRemoveRecord(
    sdRef,
    RecordRef,
    flags = 0,
    ):

    """

    Remove a record previously added to a service record set via
    DNSServiceAddRecord(), or deregister a record registered
    individually via DNSServiceRegisterRecord().

      sdRef:
        A DNSServiceRef returned by DNSServiceRegister() (if the
        record being removed was registered via DNSServiceAddRecord())
        or by DNSServiceCreateConnection() (if the record being
        removed was registered via DNSServiceRegisterRecord()).

      recordRef:
        A DNSRecordRef returned by DNSServiceAddRecord() or
        DNSServiceRegisterRecord().

      flags:
        Currently ignored, reserved for future use.

    """

    _global_lock.acquire()
    try:
        _DNSServiceRemoveRecord(sdRef,
                                RecordRef,
                                flags)
    finally:
        _global_lock.release()

    RecordRef._invalidate()


def DNSServiceBrowse(
    flags = 0,
    interfaceIndex = kDNSServiceInterfaceIndexAny,
    regtype = _NO_DEFAULT,
    domain = None,
    callBack = None,
    ):

    """

    Browse for instances of a service.

      flags:
        Currently ignored, reserved for future use.

      interfaceIndex:
        If non-zero, specifies the interface on which to browse for
        services.  Most applications will pass
        kDNSServiceInterfaceIndexAny (0) to browse on all available
        interfaces.

      regtype:
        The service type being browsed for followed by the protocol,
        separated by a dot (e.g. "_ftp._tcp").  The transport protocol
        must be "_tcp" or "_udp".

      domain:
        If not None, specifies the domain on which to browse for
        services.  Most applications will not specify a domain,
        instead browsing on the default domain(s).

      callBack:
        The function to be called when an instance of the service
        being browsed for is found, or if the call asynchronously
        fails.  Its signature should be
        callBack(sdRef, flags, interfaceIndex, errorCode,
                 serviceName, regtype, replyDomain).

      return value:
        A DNSServiceRef instance.  The browse operation will run
        indefinitely until the client terminates it by closing the
        DNSServiceRef.

    Callback Parameters:

      sdRef:
        The DNSServiceRef returned by DNSServiceBrowse().

      flags:
        Possible values are kDNSServiceFlagsMoreComing and
        kDNSServiceFlagsAdd.

      interfaceIndex:
        The interface on which the service is advertised.  This index
        should be passed to DNSServiceResolve() when resolving the
        service.

      errorCode:
        Will be kDNSServiceErr_NoError (0) on success, otherwise will
        indicate the failure that occurred.  Other parameters are
        undefined if an error occurred.

      serviceName:
        The discovered service name.  This name should be displayed to
        the user and stored for subsequent use in the
        DNSServiceResolve() call.

      regtype:
        The service type, which is usually (but not always) the same
        as was passed to DNSServiceBrowse().  One case where the
        discovered service type may not be the same as the requested
        service type is when using subtypes: The client may want to
        browse for only those ftp servers that allow anonymous
        connections.  The client will pass the string
        "_ftp._tcp,_anon" to DNSServiceBrowse(), but the type of the
        service that's discovered is simply "_ftp._tcp".  The regtype
        for each discovered service instance should be stored along
        with the name, so that it can be passed to DNSServiceResolve()
        when the service is later resolved.

      replyDomain:
        The domain of the discovered service instance.  This may or
        may not be the same as the domain that was passed to
        DNSServiceBrowse().  The domain for each discovered service
        instance should be stored along with the name, so that it can
        be passed to DNSServiceResolve() when the service is later
        resolved.

    """

    _NO_DEFAULT.check(regtype)

    @_DNSServiceBrowseReply
    def _callback(sdRef, flags, interfaceIndex, errorCode, serviceName, regtype,
                  replyDomain, context):
        if callBack is not None:
            callBack(sdRef, flags, interfaceIndex, errorCode,
                     serviceName.decode(), regtype.decode(),
                     replyDomain.decode())

    _global_lock.acquire()
    try:
        sdRef = _DNSServiceBrowse(flags,
                                  interfaceIndex,
                                  regtype,
                                  domain,
                                  _callback,
                                  None)
    finally:
        _global_lock.release()

    sdRef._add_callback(_callback)

    return sdRef


def DNSServiceResolve(
    flags = 0,
    interfaceIndex = _NO_DEFAULT,
    name = _NO_DEFAULT,
    regtype = _NO_DEFAULT,
    domain = _NO_DEFAULT,
    callBack = None,
    ):

    """

    Resolve a service name discovered via DNSServiceBrowse() to a
    target host name, port number, and txt record.

    Note: Applications should NOT use DNSServiceResolve() solely for
    txt record monitoring; use DNSServiceQueryRecord() instead, as it
    is more efficient for this task.

    Note: When the desired results have been returned, the client MUST
    terminate the resolve by closing the returned DNSServiceRef.

    Note: DNSServiceResolve() behaves correctly for typical services
    that have a single SRV record and a single TXT record.  To resolve
    non-standard services with multiple SRV or TXT records,
    DNSServiceQueryRecord() should be used.

      flags:
        Currently ignored, reserved for future use.

      interfaceIndex:
        The interface on which to resolve the service.  If this
        resolve call is as a result of a currently active
        DNSServiceBrowse() operation, then the interfaceIndex should
        be the index reported in the browse callback.  If this resolve
        call is using information previously saved (e.g. in a
        preference file) for later use, then use
        kDNSServiceInterfaceIndexAny (0), because the desired service
        may now be reachable via a different physical interface.

      name:
        The name of the service instance to be resolved, as reported
        to the DNSServiceBrowse() callback.

      regtype:
        The type of the service instance to be resolved, as reported
        to the DNSServiceBrowse() callback.

      domain:
        The domain of the service instance to be resolved, as reported
        to the DNSServiceBrowse() callback.

      callBack:
        The function to be called when a result is found, or if the
        call asynchronously fails.  Its signature should be
        callBack(sdRef, flags, interfaceIndex, errorCode, fullname,
                 hosttarget, port, txtRecord).

      return value:
        A DNSServiceRef instance.  The resolve operation will run
        indefinitely until the client terminates it by closing the
        DNSServiceRef.

    Callback Parameters:

      sdRef:
        The DNSServiceRef returned by DNSServiceResolve().

      flags:
        Currently unused, reserved for future use.

      interfaceIndex:
        The interface on which the service was resolved.

      errorCode:
        Will be kDNSServiceErr_NoError (0) on success, otherwise will
        indicate the failure that occurred.  Other parameters are
        undefined if an error occurred.

      fullname:
        The full service domain name, in the form
        <servicename>.<protocol>.<domain>.

      hosttarget:
        The target hostname of the machine providing the service.

      port:
        The port, in host (not network) byte order, on which
        connections are accepted for this service.

      txtRecord:
        A string containing the service's primary txt record, in
        standard txt record format.

    """

    _NO_DEFAULT.check(interfaceIndex)
    _NO_DEFAULT.check(name)
    _NO_DEFAULT.check(regtype)
    _NO_DEFAULT.check(domain)

    @_DNSServiceResolveReply
    def _callback(sdRef, flags, interfaceIndex, errorCode, fullname, hosttarget,
                  port, txtLen, txtRecord, context):
        if callBack is not None:
            port = socket.ntohs(port)
1533
            txtRecord = _length_and_void_p_to_byte(txtLen, txtRecord)
Wim Haanstra's avatar
Wim Haanstra committed
1534
            callBack(sdRef, flags, interfaceIndex, errorCode, fullname.decode(),
1535
                     hosttarget.decode(), port, txtRecord.decode())
Wim Haanstra's avatar
Wim Haanstra committed
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785

    _global_lock.acquire()
    try:
        sdRef = _DNSServiceResolve(flags,
                                   interfaceIndex,
                                   name,
                                   regtype,
                                   domain,
                                   _callback,
                                   None)
    finally:
        _global_lock.release()

    sdRef._add_callback(_callback)

    return sdRef


def DNSServiceCreateConnection():

    """

    Create a connection to the daemon allowing efficient registration
    of multiple individual records.

      return value:
        A DNSServiceRef instance.  Closing it severs the connection
        and deregisters all records registered on this connection.

    """

    _global_lock.acquire()
    try:
        sdRef = _DNSServiceCreateConnection()
    finally:
        _global_lock.release()

    return sdRef


def DNSServiceRegisterRecord(
    sdRef,
    flags,
    interfaceIndex = kDNSServiceInterfaceIndexAny,
    fullname = _NO_DEFAULT,
    rrtype = _NO_DEFAULT,
    rrclass = kDNSServiceClass_IN,
    rdata = _NO_DEFAULT,
    ttl = 0,
    callBack = None,
    ):

    """

    Register an individual resource record on a connected
    DNSServiceRef.

    Note that name conflicts occurring for records registered via this
    call must be handled by the client in the callback.

      sdRef:
        A DNSServiceRef returned by DNSServiceCreateConnection().

      flags:
        Possible values are kDNSServiceFlagsShared or
        kDNSServiceFlagsUnique.

      interfaceIndex:
        If non-zero, specifies the interface on which to register the
        record.  Passing kDNSServiceInterfaceIndexAny (0) causes the
        record to be registered on all interfaces.

      fullname:
        The full domain name of the resource record.

      rrtype:
        The numerical type of the resource record
        (e.g. kDNSServiceType_PTR, kDNSServiceType_SRV, etc.).

      rrclass:
        The class of the resource record (usually
        kDNSServiceClass_IN).

      rdata:
        A string containing the raw rdata, as it is to appear in the
        DNS record.

      ttl:
        The time to live of the resource record, in seconds.  Pass 0
        to use a default value.

      callBack:
        The function to be called when a result is found, or if the
        call asynchronously fails (e.g. because of a name conflict).
        Its signature should be
        callBack(sdRef, RecordRef, flags, errorCode).

      return value:
        A DNSRecordRef instance, which may be passed to
        DNSServiceUpdateRecord() or DNSServiceRemoveRecord().  (To
        deregister ALL records registered on a single connected
        DNSServiceRef and deallocate each of their corresponding
        DNSRecordRefs, close the DNSServiceRef.)

    Callback Parameters:

      sdRef:
        The connected DNSServiceRef returned by
        DNSServiceCreateConnection().

      RecordRef:
        The DNSRecordRef returned by DNSServiceRegisterRecord().

      flags:
        Currently unused, reserved for future use.

      errorCode:
        Will be kDNSServiceErr_NoError on success, otherwise will
        indicate the failure that occurred (including name conflicts).
        Other parameters are undefined if an error occurred.

    """

    _NO_DEFAULT.check(fullname)
    _NO_DEFAULT.check(rrtype)
    _NO_DEFAULT.check(rdata)

    rdlen, rdata = _string_to_length_and_void_p(rdata)

    @_DNSServiceRegisterRecordReply
    def _callback(sdRef, RecordRef, flags, errorCode, context):
        if callBack is not None:
            callBack(sdRef, RecordRef, flags, errorCode)

    _global_lock.acquire()
    try:
        RecordRef = _DNSServiceRegisterRecord(sdRef,
                                              flags,
                                              interfaceIndex,
                                              fullname,
                                              rrtype,
                                              rrclass,
                                              rdlen,
                                              rdata,
                                              ttl,
                                              _callback,
                                              None)
    finally:
        _global_lock.release()

    sdRef._add_callback(_callback)
    sdRef._add_record_ref(RecordRef)

    return RecordRef


def DNSServiceQueryRecord(
    flags = 0,
    interfaceIndex = kDNSServiceInterfaceIndexAny,
    fullname = _NO_DEFAULT,
    rrtype = _NO_DEFAULT,
    rrclass = kDNSServiceClass_IN,
    callBack = None,
    ):

    """

    Query for an arbitrary DNS record.

      flags:
        Pass kDNSServiceFlagsLongLivedQuery to create a "long-lived"
        unicast query in a non-local domain.  Without setting this
        flag, unicast queries will be one-shot; that is, only answers
        available at the time of the call will be returned.  By
        setting this flag, answers (including Add and Remove events)
        that become available after the initial call is made will
        generate callbacks.  This flag has no effect on link-local
        multicast queries.

      interfaceIndex:
        If non-zero, specifies the interface on which to issue the
        query.  Passing kDNSServiceInterfaceIndexAny (0) causes the
        name to be queried for on all interfaces.

      fullname:
        The full domain name of the resource record to be queried for.

      rrtype:
        The numerical type of the resource record to be queried for
        (e.g. kDNSServiceType_PTR, kDNSServiceType_SRV, etc.).

      rrclass:
        The class of the resource record (usually
        kDNSServiceClass_IN).

      callBack:
        The function to be called when a result is found, or if the
        call asynchronously fails.  Its signature should be
        callBack(sdRef, flags, interfaceIndex, errorCode, fullname,
                 rrtype, rrclass, rdata, ttl).

      return value:
        A DNSServiceRef instance.  The query operation will run
        indefinitely until the client terminates it by closing the
        DNSServiceRef.

    Callback Parameters:

      sdRef:
        The DNSServiceRef returned by DNSServiceQueryRecord().

      flags:
        Possible values are kDNSServiceFlagsMoreComing and
        kDNSServiceFlagsAdd.  The Add flag is NOT set for PTR records
        with a ttl of 0, i.e. "Remove" events.

      interfaceIndex:
        The interface on which the query was resolved.

      errorCode:
        Will be kDNSServiceErr_NoError on success, otherwise will
        indicate the failure that occurred.  Other parameters are
        undefined if an error occurred.

      fullname:
        The resource record's full domain name.

      rrtype:
        The resource record's type (e.g. kDNSServiceType_PTR,
        kDNSServiceType_SRV, etc.).

      rrclass:
        The class of the resource record (usually
        kDNSServiceClass_IN).

      rdata:
        A string containing the raw rdata of the resource record.

      ttl:
        The resource record's time to live, in seconds.

    """

    _NO_DEFAULT.check(fullname)
    _NO_DEFAULT.check(rrtype)

    @_DNSServiceQueryRecordReply
    def _callback(sdRef, flags, interfaceIndex, errorCode, fullname, rrtype,
                  rrclass, rdlen, rdata, ttl, context):
        if callBack is not None:
1786
            rdata = _length_and_void_p_to_byte(rdlen, rdata)
Wim Haanstra's avatar
Wim Haanstra committed
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
            callBack(sdRef, flags, interfaceIndex, errorCode, fullname.decode(),
                     rrtype, rrclass, rdata, ttl)

    _global_lock.acquire()
    try:
        sdRef = _DNSServiceQueryRecord(flags,
                                       interfaceIndex,
                                       fullname,
                                       rrtype,
                                       rrclass,
                                       _callback,
                                       None)
    finally:
        _global_lock.release()

    sdRef._add_callback(_callback)

    return sdRef


def DNSServiceReconfirmRecord(
    flags = 0,
    interfaceIndex = kDNSServiceInterfaceIndexAny,
    fullname = _NO_DEFAULT,
    rrtype = _NO_DEFAULT,
    rrclass = kDNSServiceClass_IN,
    rdata = _NO_DEFAULT,
    ):

    """

    Instruct the daemon to verify the validity of a resource record
    that appears to be out of date (e.g. because tcp connection to a
    service's target failed).  Causes the record to be flushed from
    the daemon's cache (as well as all other daemons' caches on the
    network) if the record is determined to be invalid.

      flags:
        Currently unused, reserved for future use.

      interfaceIndex: 
        If non-zero, specifies the interface of the record in
        question.  Passing kDNSServiceInterfaceIndexAny (0) causes all
        instances of this record to be reconfirmed.

      fullname:
        The resource record's full domain name.

      rrtype:
        The resource record's type (e.g. kDNSServiceType_PTR,
        kDNSServiceType_SRV, etc.).

      rrclass:
        The class of the resource record (usually
        kDNSServiceClass_IN).

      rdata:
        A string containing the raw rdata of the resource record.

    """

    _NO_DEFAULT.check(fullname)
    _NO_DEFAULT.check(rrtype)
    _NO_DEFAULT.check(rdata)

    rdlen, rdata = _string_to_length_and_void_p(rdata)

    _global_lock.acquire()
    try:
        _DNSServiceReconfirmRecord(flags,
                                   interfaceIndex,
                                   fullname,
                                   rrtype,
                                   rrclass,
                                   rdlen,
                                   rdata)
    finally:
        _global_lock.release()


def DNSServiceConstructFullName(
    service = None,
    regtype = _NO_DEFAULT, 
    domain = _NO_DEFAULT,
    ):

    """

    Concatenate a three-part domain name (as returned by a callback
    function) into a properly-escaped full domain name.  Note that
    callback functions already escape strings where necessary.

      service:
        The service name; any dots or backslashes must NOT be escaped.
        May be None (to construct a PTR record name, e.g.
        "_ftp._tcp.apple.com.").

      regtype:
        The service type followed by the protocol, separated by a dot
        (e.g. "_ftp._tcp").

      domain:
        The domain name, e.g. "apple.com.".  Literal dots or
        backslashes, if any, must be escaped,
        e.g. "1st\. Floor.apple.com."

      return value:
        The resulting full domain name.

    """

    _NO_DEFAULT.check(regtype)
    _NO_DEFAULT.check(domain)

    _global_lock.acquire()
    try:
        fullName = _DNSServiceConstructFullName(service, regtype, domain)
    finally:
        _global_lock.release()

    return fullName.value.decode('utf-8')



################################################################################
#
# TXTRecord class
#
################################################################################



class TXTRecord(object):

    """

    A mapping representing a DNS TXT record.  The TXT record's
    name=value entries are stored as key/value pairs in the mapping.
    Although keys can be accessed in a case-insensitive fashion
    (meaning txt['foo'] and txt['FoO'] refer to the same value), key
    case is preserved in the wire representation of the record (so
    txt['FoO'] = 'bar' will generate a FoO=bar entry in the TXT
    record).  Key order is also preserved, so keys appear in the wire
    format in the order in which they were created.

    Note that in addition to being valid as a txtRecord parameter to
    DNSServiceRegister(), a TXTRecord instance can be used in place of
    a resource record data string (i.e. rdata parameter) with any
    function that accepts one.

    """

    def __init__(self, items={}, strict=True):
        """

        Create a new TXTRecord instance, initializing it with the
        contents of items.  If strict is true, then strict conformance
        to the DNS TXT record format will be enforced, and attempts to
        add a name containing invalid characters or a name/value pair
        whose wire representation is longer than 255 bytes will raise
        a ValueError exception.

        """

        self.strict = strict
        self._names = []
        self._items = {}

1955
        for name, value in items.items():
Wim Haanstra's avatar
Wim Haanstra committed
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
            self[name] = value

    def __contains__(self, name):
        'Return True if name is a key in the record, False otherwise'
        return (name.lower() in self._items)

    def __iter__(self):
        'Return an iterator over name/value pairs'
        for name in self._names:
            yield self._items[name]

    def __len__(self):
        'Return the number of name/value pairs'
        return len(self._names)

    def __nonzero__(self):
        'Return False if the record is empty, True otherwise'
        return bool(self._items)

    def __str__(self):
        """

        Return the wire representation of the TXT record as a string.
        If self.strict is false, any name/value pair whose wire length
        if greater than 255 bytes will be truncated to 255 bytes.  If
        the record is empty, '\\0' is returned.

        """

        if not self:
            return '\0'

        parts = []
        for name, value in self:
            if value is None:
                item = name
            else:
                item = '%s=%s' % (name, value)
            if (not self.strict) and (len(item) > 255):
                item = item[:255]
            parts.append(chr(len(item)))
            parts.append(item)

        return ''.join(parts)

    def __getitem__(self, name):
        """

        Return the value associated with name.  The value is either
        None (meaning name has no associated value) or an str instance
        (which may be of length 0).  Raises KeyError if name is not a
        key.

        """
        return self._items[name.lower()][1]

    # Require one or more printable ASCII characters (0x20-0x7E),
    # excluding '=' (0x3D)
    _valid_name_re = re.compile(r'^[ -<>-~]+$')

    def __setitem__(self, name, value):
        """

        Add a name/value pair to the record.  If value is None, then
        name will have no associated value.  If value is a unicode
        instance, it will be encoded as a UTF-8 string.  Otherwise,
        value will be converted to an str instance.

        """

        stored_name = name
        name = name.lower()
        length = len(name)

        if value is not None:
            value = str(value)
            length += 1 + len(value)

        if self.strict and (length > 255):
            raise ValueError('name=value string must be 255 bytes or less')

        if name not in self._items:
            if self.strict and (self._valid_name_re.match(stored_name) is None):
                raise ValueError("invalid name: '%s'" % stored_name)
            self._names.append(name)

        self._items[name] = (stored_name, value)

    def __delitem__(self, name):
        """

        Remove name and its corresponding value from the record.
        Raises KeyError if name is not a key.

        """
        name = name.lower()
        del self._items[name]
        self._names.remove(name)

    @classmethod
    def parse(cls, data, strict=False):
        """

        Given a string data containing the wire representation of a
        DNS TXT record, parse it and return a TXTRecord instance.  The
        strict parameter is passed to the TXTRecord constructor.

        """

        txt = cls(strict=strict)

        while data:
            length = ord(data[0])
            item = data[1:length+1].split('=', 1)

            # Add the item only if the name is non-empty and there are
            # no existing items with the same name
            if item[0] and (item[0] not in txt):
                if len(item) == 1:
                    txt[item[0]] = None
                else:
                    txt[item[0]] = item[1]

            data = data[length+1:]

        return txt