uDNS.c revision 4904:cd464a980538 
1/* -*- Mode: C; tab-width: 4 -*-
2 *
3 * Copyright (c) 2002-2006 Apple Computer, Inc. All rights reserved.
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 *     http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16
17    Change History (most recent first):
18
19$Log: uDNS.c,v $
20Revision 1.230.2.1  2006/08/29 06:24:23  cheshire
21Re-licensed mDNSResponder daemon source code under Apache License, Version 2.0
22
23Revision 1.230  2006/06/29 03:02:44  cheshire
24<rdar://problem/4607042> mDNSResponder NXDOMAIN and CNAME support
25
26Revision 1.229  2006/03/02 22:03:41  cheshire
27<rdar://problem/4395331> Spurious warning "GetLargeResourceRecord: m->rec appears to be already in use"
28Refinement: m->rec.r.resrec.RecordType needs to be cleared *every* time around for loop, not just once at the end
29
30Revision 1.228  2006/02/26 00:54:42  cheshire
31Fixes to avoid code generation warning/error on FreeBSD 7
32
33Revision 1.227  2006/01/09 20:47:05  cheshire
34<rdar://problem/4395331> Spurious warning "GetLargeResourceRecord: m->rec appears to be already in use"
35
36Revision 1.226  2005/12/20 02:46:33  cheshire
37<rdar://problem/4175520> mDNSPosix wide-area registration broken
38Check too strict -- we can still do wide-area registration (without NAT-PMP)
39without having to know our gateway address
40
41Revision 1.225  2005/10/21 22:51:17  cheshire
42<rdar://problem/4290265> Add check to avoid crashing NAT gateways that have buggy DNS relay code
43Refinement: Shorten "check-for-broken-dns-relay" to just "dnsbugtest"
44to avoid crashing NAT gateways that have a different DNS relay bug
45
46Revision 1.224  2005/10/20 00:10:33  cheshire
47<rdar://problem/4290265> Add check to avoid crashing NAT gateways that have buggy DNS relay code
48
49Revision 1.223  2005/10/17 18:52:42  cheshire
50<rdar://problem/4271183> mDNSResponder crashed in CheckRecordRegistrations
51Move code to unregister the service's extra records from uDNS_DeregisterService() to unlinkSRS().
52
53Revision 1.222  2005/10/05 23:04:10  cheshire
54Add more information to unlinkAR and startLLQHandshakeCallback error messages
55
56Revision 1.221  2005/10/05 17:27:48  herscher
57<rdar://problem/4272516> Change 200ms delay to 10ms
58
59Revision 1.220  2005/09/24 01:10:09  cheshire
60Fix comment typos
61
62Revision 1.219  2005/09/22 07:28:25  herscher
63Double the delay to 200000 usec after sending out a DNS query
64
65Revision 1.218  2005/09/13 01:06:14  herscher
66<rdar://problem/4248878> Add 100ms delay in sendQuery.
67
68Revision 1.217  2005/08/04 18:08:24  cheshire
69Update comments
70
71Revision 1.216  2005/07/29 23:05:22  ksekar
72<rdar://problem/4137930> Hostname registration should register IPv6 AAAA record with DNS Update
73Services should point to IPv6 address if IPv4 NAT mapping fails
74
75Revision 1.215  2005/07/29 21:01:51  ksekar
76<rdar://problem/4137930> Hostname registration should register IPv6 AAAA record with DNS Update
77correction to original checkin - misplaced return in HostnameCallback and logic error determining v6 changes
78
79Revision 1.214  2005/07/29 19:46:10  ksekar
80<rdar://problem/4191860> reduce polling period on failed LLQs to 15 minutes
81
82Revision 1.213  2005/07/29 18:04:22  ksekar
83<rdar://problem/4137930> Hostname registration should register IPv6 AAAA record with DNS Update
84
85Revision 1.212  2005/07/22 19:35:50  ksekar
86<rdar://problem/4188821> SUTiger: LLQ event acknowledgments are not formated correctly
87
88Revision 1.211  2005/07/21 18:51:04  ksekar
89<rdar://problem/4103136> mDNSResponder times out when mapping ports after sleep
90
91Revision 1.210  2005/07/21 18:47:31  ksekar
92<rdar://problem/4137283> NAT-PMP refresh Requested Public Port should contain actual mapped port
93
94Revision 1.209  2005/07/04 21:16:37  cheshire
95Minor code tidying -- initialize variables where they are declared
96
97Revision 1.208  2005/06/28 00:24:28  ksekar
98<rdar://problem/4157823> memory smasher in conQueryCallback
99
100Revision 1.207  2005/05/13 20:45:10  ksekar
101<rdar://problem/4074400> Rapid wide-area txt record updates don't work
102
103Revision 1.206  2005/03/31 02:19:55  cheshire
104<rdar://problem/4021486> Fix build warnings
105Reviewed by: Scott Herscher
106
107Revision 1.205  2005/03/21 00:33:51  shersche
108<rdar://problem/4021486> Fix build warnings on Win32 platform
109
110Revision 1.204  2005/03/16 00:42:32  ksekar
111<rdar://problem/4012279> Long-lived queries not working on Windows
112
113Revision 1.203  2005/03/04 03:00:03  ksekar
114<rdar://problem/4026546> Retransmissions happen too early, causing registrations to conflict with themselves
115
116Revision 1.202  2005/03/01 19:29:17  ksekar
117changed LogMsgs to debugfs
118
119Revision 1.201  2005/02/26 03:04:13  cheshire
120<rdar://problem/4017292> Should not indicate successful dynamic update if no network connection
121Don't try to do updates to root name server. This ensures status dot turns red if user
122enters a bad host name such as just "fred" instead of a properly fully-qualified name.
123
124Revision 1.200  2005/02/25 17:47:45  ksekar
125<rdar://problem/4021868> SendServiceRegistration fails on wake from sleep
126
127Revision 1.199  2005/02/25 04:21:00  cheshire
128<rdar://problem/4015377> mDNS -F returns the same domain multiple times with different casing
129
130Revision 1.198  2005/02/25 02:35:22  cheshire
131<rdar://problem/4017292> Should not indicate successful dynamic update if no network connection
132If we get NXDomain error looking for the _dns-update._udp record,
133update status from 1 (in progress) to mStatus_NoSuchNameErr (failed)
134
135Revision 1.197  2005/02/24 21:56:59  ksekar
136Change LogMsgs to debugfs
137
138Revision 1.196  2005/02/24 21:52:28  ksekar
139<rdar://problem/3922768> Remove "deferred deregistration" logic for hostnames
140
141Revision 1.195  2005/02/22 17:53:08  ksekar
142Changed successful NAT Traversals from LogMsg to LogOperation
143
144Revision 1.194  2005/02/15 18:38:03  ksekar
145<rdar://problem/3967876> change expected/redundant log messages to debugfs.
146
147Revision 1.193  2005/02/15 01:17:48  ksekar
148Fixed build failure.
149
150Revision 1.192  2005/02/14 23:01:28  ksekar
151Refinement to previous checkin - don't log bad LLQ opcode if we had to send the request more than once.
152
153Revision 1.191  2005/02/14 18:26:51  ksekar
154<rdar://problem/4005569> mDNSResponder complains about bad LLQ Opcode 2
155
156Revision 1.190  2005/02/11 19:44:06  shersche
157Remove extra semicolon at end of line
158
159Revision 1.189  2005/02/10 21:07:02  ksekar
160Don't goto error in ReceiveNATAddrResponse if we receive a malformatted response
161
162Revision 1.188  2005/02/10 02:02:44  ksekar
163Remove double semi-colon
164
165Revision 1.187  2005/02/09 23:28:01  ksekar
166<rdar://problem/3984374> NAT-PMP response callback should return a
167boolean indicating if the packet matched the request
168
169Revision 1.186  2005/02/04 21:56:29  ksekar
170<rdar://problem/3984374> Simultaneous port map requests sometimes fail
171- Refinement to previous checkin.
172
173Revision 1.185  2005/02/03 23:48:22  ksekar
174<rdar://problem/3984374> Simultaneous port map requests sometimes fail
175
176Revision 1.184  2005/02/01 19:33:29  ksekar
177<rdar://problem/3985239> Keychain format too restrictive
178
179Revision 1.183  2005/01/27 22:57:55  cheshire
180Fix compile errors on gcc4
181
182Revision 1.182  2005/01/25 18:55:05  ksekar
183Shortened log message
184
185Revision 1.181  2005/01/25 02:17:32  cheshire
186<rdar://problem/3971263> Don't use query ID zero in uDNS queries
187
188Revision 1.180  2005/01/19 21:01:54  ksekar
189<rdar://problem/3955355> uDNS needs to support subtype registration and browsing
190
191Revision 1.179  2005/01/19 19:15:35  ksekar
192Refinement to <rdar://problem/3954575> - Simplify mDNS_PurgeResultsForDomain logic and move into daemon layer
193
194Revision 1.178  2005/01/17 23:47:58  cheshire
195<rdar://problem/3904954> Wide-area services not found on little-endian
196
197Revision 1.177  2005/01/17 23:41:26  cheshire
198Fix compile errors
199
200Revision 1.176  2005/01/17 21:03:04  cheshire
201<rdar://problem/3904954> Wide-area services not found on little-endian
202
203Revision 1.175  2005/01/15 00:56:41  ksekar
204<rdar://problem/3954575> Unicast services don't disappear when logging
205out of VPN
206
207Revision 1.174  2005/01/14 18:44:28  ksekar
208<rdar://problem/3954609> mDNSResponder is crashing when changing domains
209
210Revision 1.173  2005/01/14 18:34:22  ksekar
211<rdar://problem/3954571> Services registered outside of firewall don't succeed after location change
212
213Revision 1.172  2005/01/11 22:50:52  ksekar
214Fixed constant naming (was using kLLQ_DefLease for update leases)
215
216Revision 1.171  2005/01/10 04:52:49  ksekar
217Changed LogMsg to debugf
218
219Revision 1.170  2005/01/08 00:50:05  ksekar
220Fixed spelling mistake in log msg
221
222Revision 1.169  2005/01/08 00:42:18  ksekar
223<rdar://problem/3922758> Clean up syslog messages
224
225Revision 1.168  2004/12/23 23:22:47  ksekar
226<rdar://problem/3933606> Unicast known answers "name" pointers point to garbage stack memory
227
228Revision 1.167  2004/12/22 22:25:47  ksekar
229<rdar://problem/3734265> NATPMP: handle location changes
230
231Revision 1.166  2004/12/22 00:04:12  ksekar
232<rdar://problem/3930324> mDNSResponder crashing in ReceivePortMapReply
233
234Revision 1.165  2004/12/18 03:14:22  cheshire
235DblNAT -> DoubleNAT
236
237Revision 1.164  2004/12/17 03:55:40  ksekar
238Don't use -1 as special meaning for expiration timer (it is a valid
239value, and is redundant with our state variables)
240
241Revision 1.163  2004/12/17 03:51:53  ksekar
242<rdar://problem/3920991> Don't update TXT record if service registration fails
243
244Revision 1.162  2004/12/17 01:29:11  ksekar
245<rdar://problem/3920598> Questions can go deaf on location changes
246
247Revision 1.161  2004/12/16 20:42:02  cheshire
248Fix compiler warnings
249
250Revision 1.160  2004/12/16 20:13:00  cheshire
251<rdar://problem/3324626> Cache memory management improvements
252
253Revision 1.159  2004/12/15 02:11:22  ksekar
254<rdar://problem/3917317> Don't check for Dynamic DNS hostname uniqueness
255
256Revision 1.158  2004/12/15 02:04:28  ksekar
257Refinement to previous checkin - we should still return NatTraversal error  when the port mapping fails
258
259Revision 1.157  2004/12/15 01:39:21  ksekar
260Refinement to previous checkin - we should still return NatTraversal error  when the port mapping fails
261
262Revision 1.156  2004/12/15 01:18:57  ksekar
263<rdar://problem/3825979> Call DeregisterService on nat port map failure
264
265Revision 1.155  2004/12/14 21:21:20  ksekar
266<rdar://problem/3825979> NAT-PMP: Update response format to contain "Seconds Since Boot"
267
268Revision 1.154  2004/12/14 20:52:27  cheshire
269Add question->qnamehash and cr->resrec.namehash to log message
270
271Revision 1.153  2004/12/14 20:45:02  cheshire
272Improved error logging in "unexpected answer" message
273
274Revision 1.152  2004/12/14 03:02:10  ksekar
275<rdar://problem/3919016> Rare race condition can cause crash
276
277Revision 1.151  2004/12/13 21:45:08  ksekar
278uDNS_DeregisterService should return NoError if called twice (to follow mDNS behavior expected by daemon layer)
279
280Revision 1.150  2004/12/13 20:42:41  ksekar
281Fixed LogMsg
282
283Revision 1.149  2004/12/13 18:10:03  ksekar
284Fixed LogMsg
285
286Revision 1.148  2004/12/13 01:18:04  ksekar
287Fixed unused variable warning for non-debug builds
288
289Revision 1.147  2004/12/12 23:51:42  ksekar
290<rdar://problem/3845683> Wide-area registrations should fallback to using DHCP hostname as target
291
292Revision 1.146  2004/12/12 23:30:40  ksekar
293<rdar://problem/3916987> Extra RRs not properly unlinked when parent service registration fails
294
295Revision 1.145  2004/12/12 22:56:29  ksekar
296<rdar://problem/3668508> Need to properly handle duplicate long-lived queries
297
298Revision 1.144  2004/12/11 20:55:29  ksekar
299<rdar://problem/3916479> Clean up registration state machines
300
301Revision 1.143  2004/12/10 01:21:27  cheshire
302<rdar://problem/3914089> Get rid of "LLQ Responses over TCP not currently supported" message
303
304Revision 1.142  2004/12/08 02:03:31  ksekar
305<rdar://problem/3865124> Looping on NAT Traversal error - check for
306NULL RR on error
307
308Revision 1.141  2004/12/07 01:39:28  cheshire
309Don't fail if the same server is responsible for more than one domain
310(e.g. the same DNS server may be responsible for both apple.com. and 17.in-addr.arpa.)
311
312Revision 1.140  2004/12/06 21:15:22  ksekar
313<rdar://problem/3884386> mDNSResponder crashed in CheckServiceRegistrations
314
315Revision 1.139  2004/12/06 19:08:03  cheshire
316Add clarifying comment -- CountLabels() excludes the final root label.
317
318Revision 1.138  2004/12/06 01:45:54  ksekar
319Correct wording in LogMsg
320
321Revision 1.137  2004/12/03 20:40:35  ksekar
322<rdar://problem/3865124> Looping on NAT Traversal error
323
324Revision 1.136  2004/12/03 07:20:50  ksekar
325<rdar://problem/3674208> Wide-Area: Registration of large TXT record fails
326
327Revision 1.135  2004/12/03 05:18:33  ksekar
328<rdar://problem/3810596> mDNSResponder needs to return more specific TSIG errors
329
330Revision 1.134  2004/12/02 20:03:49  ksekar
331<rdar://problem/3889647> Still publishes wide-area domains even after switching to a local subnet
332
333Revision 1.133  2004/12/02 18:37:52  ksekar
334<rdar://problem/3758233> Registering with port number zero should not create a port mapping
335
336Revision 1.132  2004/12/01 20:57:19  ksekar
337<rdar://problem/3873921> Wide Area Service Discovery must be split-DNS aware
338
339Revision 1.131  2004/12/01 19:59:27  cheshire
340<rdar://problem/3882643> Crash in mDNSPlatformTCPConnect
341If a TCP response has the TC bit set, don't respond by just trying another TCP connection
342
343Revision 1.130  2004/12/01 02:43:23  cheshire
344Don't call StatusCallback if function pointer is null
345
346Revision 1.129  2004/11/30 23:51:06  cheshire
347Remove double semicolons
348
349Revision 1.128  2004/11/25 01:48:30  ksekar
350<rdar://problem/3878991> Logging into VPN does not trigger registration of address record
351
352Revision 1.127  2004/11/25 01:41:36  ksekar
353Changed unnecessary LogMsgs to debugfs
354
355Revision 1.126  2004/11/23 23:54:17  ksekar
356<rdar://problem/3890318> Wide-Area DNSServiceRegisterRecord() failures
357can crash mDNSResponder
358
359Revision 1.125  2004/11/23 04:16:48  cheshire
360Removed receiveMsg() routine.
361
362Revision 1.124  2004/11/23 04:06:51  cheshire
363Get rid of floating point constant -- in a small embedded device, bringing in all
364the floating point libraries just to halve an integer value is a bit too heavyweight.
365
366Revision 1.123  2004/11/22 17:16:20  ksekar
367<rdar://problem/3854298> Unicast services don't disappear when you disable all networking
368
369Revision 1.122  2004/11/19 18:00:34  ksekar
370<rdar://problem/3682646> Security: use random ID for one-shot unicast queries
371
372Revision 1.121  2004/11/19 04:24:08  ksekar
373<rdar://problem/3682609> Security: Enforce a "window" on one-shot wide-area queries
374
375Revision 1.120  2004/11/19 02:32:43  ksekar
376<rdar://problem/3682608> Wide-Area Security: Add LLQ-ID to events
377
378Revision 1.119  2004/11/18 23:21:24  ksekar
379<rdar://problem/3764544> LLQ Security: Need to verify src port/address for LLQ handshake
380
381Revision 1.118  2004/11/18 22:58:37  ksekar
382Removed old comment.
383
384Revision 1.117  2004/11/18 18:04:21  ksekar
385Restore checkins lost due to repository disk failure: Update comments & <rdar://problem/3880688>
386
387Revision 1.xxx  2004/11/17 06:17:57  cheshire
388Update comments to show correct SRV names: _dns-update._udp.<zone>. and _dns-llq._udp.<zone>.
389
390Revision 1.xxx  2004/11/17 00:45:28  ksekar
391<rdar://problem/3880688> Result of putUpdateLease not error-checked
392
393Revision 1.116  2004/11/16 01:41:47  ksekar
394Fixed typo in debugf
395
396Revision 1.115  2004/11/15 20:09:24  ksekar
397<rdar://problem/3719050> Wide Area support for Add/Remove record
398
399Revision 1.114  2004/11/13 02:32:47  ksekar
400<rdar://problem/3868216> LLQ mobility fragile on non-primary interface
401- fixed incorrect state comparison in CheckQueries
402
403Revision 1.113  2004/11/13 02:29:52  ksekar
404<rdar://problem/3878386> LLQ refreshes not reliable
405
406Revision 1.112  2004/11/11 20:45:14  ksekar
407<rdar://problem/3876052> self-conflict test not compatible with some BIND servers
408
409Revision 1.111  2004/11/11 20:14:55  ksekar
410<rdar://problem/3719574> Wide-Area registrations not deregistered on sleep
411
412Revision 1.110  2004/11/10 23:53:53  ksekar
413Remove no longer relevant comment
414
415Revision 1.109  2004/11/10 20:40:53  ksekar
416<rdar://problem/3868216> LLQ mobility fragile on non-primary interface
417
418Revision 1.108  2004/11/01 20:36:16  ksekar
419<rdar://problem/3802395> mDNSResponder should not receive Keychain Notifications
420
421Revision 1.107  2004/10/26 06:11:41  cheshire
422Add improved logging to aid in diagnosis of <rdar://problem/3842714> mDNSResponder crashed
423
424Revision 1.106  2004/10/26 03:52:03  cheshire
425Update checkin comments
426
427Revision 1.105  2004/10/26 01:15:06  cheshire
428Use "#if 0" instead of commenting out code
429
430Revision 1.104  2004/10/25 21:41:38  ksekar
431<rdar://problem/3852958> wide-area name conflicts can cause crash
432
433Revision 1.103  2004/10/25 19:30:52  ksekar
434<rdar://problem/3827956> Simplify dynamic host name structures
435
436Revision 1.102  2004/10/23 01:16:00  cheshire
437<rdar://problem/3851677> uDNS operations not always reliable on multi-homed hosts
438
439Revision 1.101  2004/10/22 20:52:07  ksekar
440<rdar://problem/3799260> Create NAT port mappings for Long Lived Queries
441
442Revision 1.100  2004/10/20 02:16:41  cheshire
443Improve "could not confirm existence of NS record" error message
444Don't call newRR->RecordCallback if it is NULL
445
446Revision 1.99  2004/10/19 21:33:18  cheshire
447<rdar://problem/3844991> Cannot resolve non-local registrations using the mach API
448Added flag 'kDNSServiceFlagsForceMulticast'. Passing through an interface id for a unicast name
449doesn't force multicast unless you set this flag to indicate explicitly that this is what you want
450
451Revision 1.98  2004/10/16 00:16:59  cheshire
452<rdar://problem/3770558> Replace IP TTL 255 check with local subnet source address check
453
454Revision 1.97  2004/10/15 23:00:18  ksekar
455<rdar://problem/3799242> Need to update LLQs on location changes
456
457Revision 1.96  2004/10/12 23:30:44  ksekar
458<rdar://problem/3609944> mDNSResponder needs to follow CNAME referrals
459
460Revision 1.95  2004/10/12 03:15:09  ksekar
461<rdar://problem/3835612> mDNS_StartQuery shouldn't return transient no-server error
462
463Revision 1.94  2004/10/12 02:49:20  ksekar
464<rdar://problem/3831228> Clean up LLQ sleep/wake, error handling
465
466Revision 1.93  2004/10/08 04:17:25  ksekar
467<rdar://problem/3831819> Don't use DNS extensions if the server does not advertise required SRV record
468
469Revision 1.92  2004/10/08 03:54:35  ksekar
470<rdar://problem/3831802> Refine unicast polling intervals
471
472Revision 1.91  2004/09/30 17:45:34  ksekar
473<rdar://problem/3821119> lots of log messages: mDNS_SetPrimaryIP: IP address unchanged
474
475Revision 1.90  2004/09/25 00:22:13  ksekar
476<rdar://problem/3815534> Crash in uDNS_RegisterService
477
478Revision 1.89  2004/09/24 19:14:53  cheshire
479Remove unused "extern mDNS mDNSStorage"
480
481Revision 1.88  2004/09/23 20:48:15  ksekar
482Clarify retransmission debugf messages.
483
484Revision 1.87  2004/09/22 00:41:59  cheshire
485Move tcp connection status codes into the legal range allocated for mDNS use
486
487Revision 1.86  2004/09/21 23:40:11  ksekar
488<rdar://problem/3810349> mDNSResponder to return errors on NAT traversal failure
489
490Revision 1.85  2004/09/21 22:38:27  ksekar
491<rdar://problem/3810286> PrimaryIP type uninitialized
492
493Revision 1.84  2004/09/18 00:30:39  cheshire
494<rdar://problem/3806643> Infinite loop in CheckServiceRegistrations
495
496Revision 1.83  2004/09/17 00:31:51  cheshire
497For consistency with ipv6, renamed rdata field 'ip' to 'ipv4'
498
499Revision 1.82  2004/09/16 21:36:36  cheshire
500<rdar://problem/3803162> Fix unsafe use of mDNSPlatformTimeNow()
501Changes to add necessary locking calls around unicast DNS operations
502
503Revision 1.81  2004/09/16 02:29:39  cheshire
504Moved mDNS_Lock/mDNS_Unlock to DNSCommon.c; Added necessary locking around
505uDNS_ReceiveMsg, uDNS_StartQuery, uDNS_UpdateRecord, uDNS_RegisterService
506
507Revision 1.80  2004/09/16 01:58:21  cheshire
508Fix compiler warnings
509
510Revision 1.79  2004/09/16 00:24:48  cheshire
511<rdar://problem/3803162> Fix unsafe use of mDNSPlatformTimeNow()
512
513Revision 1.78  2004/09/15 01:16:57  ksekar
514<rdar://problem/3797598> mDNSResponder printing too many messages
515
516Revision 1.77  2004/09/14 23:27:47  cheshire
517Fix compile errors
518
519Revision 1.76  2004/09/14 22:22:00  ksekar
520<rdar://problem/3800920> Legacy browses broken against some BIND versions
521
522Revision 1.75  2004/09/03 19:23:05  ksekar
523<rdar://problem/3788460>: Need retransmission mechanism for wide-area service registrations
524
525Revision 1.74  2004/09/02 17:49:04  ksekar
526<rdar://problem/3785135>: 8A246: mDNSResponder crash while logging on restart
527Fixed incorrect conversions, changed %s to %##s for all domain names.
528
529Revision 1.73  2004/09/02 01:39:40  cheshire
530For better readability, follow consistent convention that QR bit comes first, followed by OP bits
531
532Revision 1.72  2004/09/01 03:59:29  ksekar
533<rdar://problem/3783453>: Conditionally compile out uDNS code on Windows
534
535Revision 1.71  2004/08/27 17:51:53  ksekar
536Replaced unnecessary LogMsg with debugf.
537
538Revision 1.70  2004/08/25 00:37:27  ksekar
539<rdar://problem/3774635>: Cleanup DynDNS hostname registration code
540
541Revision 1.69  2004/08/18 17:35:41  ksekar
542<rdar://problem/3651443>: Feature #9586: Need support for Legacy NAT gateways
543
544Revision 1.68  2004/08/14 03:22:41  cheshire
545<rdar://problem/3762579> Dynamic DNS UI <-> mDNSResponder glue
546Add GetUserSpecifiedDDNSName() routine
547Convert ServiceRegDomain to domainname instead of C string
548Replace mDNS_GenerateFQDN/mDNS_GenerateGlobalFQDN with mDNS_SetFQDNs
549
550Revision 1.67  2004/08/13 23:46:58  cheshire
551"asyncronous" -> "asynchronous"
552
553Revision 1.66  2004/08/13 23:37:02  cheshire
554Now that we do both uDNS and mDNS, global replace "uDNS_info.hostname" with
555"uDNS_info.UnicastHostname" for clarity
556
557Revision 1.65  2004/08/13 23:12:32  cheshire
558Don't use strcpy() and strlen() on "struct domainname" objects;
559use AssignDomainName() and DomainNameLength() instead
560(A "struct domainname" is a collection of packed pascal strings, not a C string.)
561
562Revision 1.64  2004/08/13 23:01:05  cheshire
563Use platform-independent mDNSNULL instead of NULL
564
565Revision 1.63  2004/08/12 00:32:36  ksekar
566<rdar://problem/3759567>: LLQ Refreshes never terminate if unanswered
567
568Revision 1.62  2004/08/10 23:19:14  ksekar
569<rdar://problem/3722542>: DNS Extension daemon for Wide Area Service Discovery
570Moved routines/constants to allow extern access for garbage collection daemon
571
572Revision 1.61  2004/07/30 17:40:06  ksekar
573<rdar://problem/3739115>: TXT Record updates not available for wide-area services
574
575Revision 1.60  2004/07/29 19:40:05  ksekar
576NATPMP Support - minor fixes and cleanup
577
578Revision 1.59  2004/07/29 19:27:15  ksekar
579NATPMP Support - minor fixes and cleanup
580
581Revision 1.58  2004/07/27 07:35:38  shersche
582fix syntax error, variables declared in the middle of a block
583
584Revision 1.57  2004/07/26 22:49:30  ksekar
585<rdar://problem/3651409>: Feature #9516: Need support for NATPMP in client
586
587Revision 1.56  2004/07/26 19:14:44  ksekar
588<rdar://problem/3737814>: 8A210: mDNSResponder crashed in startLLQHandshakeCallback
589
590Revision 1.55  2004/07/15 19:01:33  ksekar
591<rdar://problem/3681029>: Check for incorrect time comparisons
592
593Revision 1.54  2004/06/22 02:10:53  ksekar
594<rdar://problem/3705433>: Lighthouse failure causes packet flood to DNS
595
596Revision 1.53  2004/06/17 20:49:09  ksekar
597<rdar://problem/3690436>: mDNSResponder crash while location cycling
598
599Revision 1.52  2004/06/17 01:13:11  ksekar
600<rdar://problem/3696616>: polling interval too short
601
602Revision 1.51  2004/06/10 04:36:44  cheshire
603Fix compiler warning
604
605Revision 1.50  2004/06/10 00:55:13  ksekar
606<rdar://problem/3686213>: crash on network reconnect
607
608Revision 1.49  2004/06/10 00:10:50  ksekar
609<rdar://problem/3686174>: Infinite Loop in uDNS_Execute()
610
611Revision 1.48  2004/06/09 20:03:37  ksekar
612<rdar://problem/3686163>: Incorrect copying of resource record in deregistration
613
614Revision 1.47  2004/06/09 03:48:28  ksekar
615<rdar://problem/3685226>: nameserver address fails with prod. Lighthouse server
616
617Revision 1.46  2004/06/09 01:44:30  ksekar
618<rdar://problem/3681378> reworked Cache Record copy code
619
620Revision 1.45  2004/06/08 18:54:47  ksekar
621<rdar://problem/3681378>: mDNSResponder leaks after exploring in Printer Setup Utility
622
623Revision 1.44  2004/06/05 00:33:51  cheshire
624<rdar://problem/3681029>: Check for incorrect time comparisons
625
626Revision 1.43  2004/06/05 00:14:44  cheshire
627Fix signed/unsigned and other compiler warnings
628
629Revision 1.42  2004/06/04 22:36:16  ksekar
630Properly set u->nextevent in uDNS_Execute
631
632Revision 1.41  2004/06/04 08:58:29  ksekar
633<rdar://problem/3668624>: Keychain integration for secure dynamic update
634
635Revision 1.40  2004/06/03 03:09:58  ksekar
636<rdar://problem/3668626>: Garbage Collection for Dynamic Updates
637
638Revision 1.39  2004/06/01 23:46:50  ksekar
639<rdar://problem/3675149>: DynDNS: dynamically look up LLQ/Update ports
640
641Revision 1.38  2004/05/31 22:19:44  ksekar
642<rdar://problem/3258021>: Feature: DNS server->client notification on
643record changes (#7805) - revert to polling mode on setup errors
644
645Revision 1.37  2004/05/28 23:42:37  ksekar
646<rdar://problem/3258021>: Feature: DNS server->client notification on record changes (#7805)
647
648Revision 1.36  2004/05/18 23:51:25  cheshire
649Tidy up all checkin comments to use consistent "<rdar://problem/xxxxxxx>" format for bug numbers
650
651Revision 1.35  2004/05/07 23:01:04  ksekar
652Cleaned up list traversal in deriveGoodbyes - removed unnecessary
653conditional assignment.
654
655Revision 1.34  2004/05/05 18:26:12  ksekar
656Periodically re-transmit questions if the send() fails.  Include
657internal questions in retransmission.
658
659Revision 1.33  2004/05/05 17:40:06  ksekar
660Removed prerequisite from deregistration update - it does not work for
661shared records, and is unnecessary until we have more sophisticated
662name conflict management.
663
664Revision 1.32  2004/05/05 17:32:18  ksekar
665Prevent registration of loopback interface caused by removal of
666Multicast flag in interface structure.
667
668Revision 1.31  2004/05/05 17:05:02  ksekar
669Use LargeCacheRecord structs when pulling records off packets
670
671Revision 1.30  2004/04/16 21:33:27  ksekar
672Fixed bug in processing GetZoneData responses that do not use BIND formatting.
673
674Revision 1.29  2004/04/15 20:03:13  ksekar
675Clarified log message when pulling bad resource records off packet.
676
677Revision 1.28  2004/04/15 00:51:28  bradley
678Minor tweaks for Windows and C++ builds. Added casts for signed/unsigned integers and 64-bit pointers.
679Prefix some functions with mDNS to avoid conflicts. Disable benign warnings on Microsoft compilers.
680
681Revision 1.27  2004/04/14 23:09:28  ksekar
682Support for TSIG signed dynamic updates.
683
684Revision 1.26  2004/04/14 19:36:05  ksekar
685Fixed memory corruption error in deriveGoodbyes.
686
687Revision 1.25  2004/04/14 04:07:11  ksekar
688Fixed crash in IsActiveUnicastQuery().  Removed redundant checks in routine.
689
690Revision 1.24  2004/04/08 09:41:40  bradley
691Added const to AuthRecord in deadvertiseIfCallback to match callback typedef.
692
693Revision 1.23  2004/03/24 00:29:45  ksekar
694Make it safe to call StopQuery in a unicast question callback
695
696Revision 1.22  2004/03/19 10:11:09  bradley
697Added AuthRecord * cast from umalloc for C++ builds.
698
699Revision 1.21  2004/03/15 02:03:45  bradley
700Added const to params where needed to match prototypes. Changed SetNewRData calls to use 0 instead
701of -1 for unused size to fix warning. Disable assignment within conditional warnings with Visual C++.
702
703Revision 1.20  2004/03/13 02:07:26  ksekar
704<rdar://problem/3192546>: DynDNS: Dynamic update of service records
705
706Revision 1.19  2004/03/13 01:57:33  ksekar
707<rdar://problem/3192546>: DynDNS: Dynamic update of service records
708
709Revision 1.18  2004/02/21 08:34:15  bradley
710Added casts from void * to specific type for C++ builds. Changed void * l-value cast
711r-value cast to fix problems with VC++ builds. Removed empty switch to fix VC++ error.
712
713Revision 1.17  2004/02/21 02:06:24  cheshire
714Can't use anonymous unions -- they're non-standard and don't work on all compilers
715
716Revision 1.16  2004/02/12 01:51:45  cheshire
717Don't try to send uDNS queries unless we have at least one uDNS server available
718
719Revision 1.15  2004/02/10 03:02:46  cheshire
720Fix compiler warning
721
722Revision 1.14  2004/02/06 23:04:19  ksekar
723Basic Dynamic Update support via mDNS_Register (dissabled via
724UNICAST_REGISTRATION #define)
725
726Revision 1.13  2004/02/03 22:15:01  ksekar
727Fixed nameToAddr error check: don't abort state machine on nxdomain error.
728
729Revision 1.12  2004/02/03 19:47:36  ksekar
730Added an asynchronous state machine mechanism to uDNS.c, including
731calls to find the parent zone for a domain name.  Changes include code
732in repository previously dissabled via "#if 0 incomplete".  Codepath
733is currently unused, and will be called to create update records, etc.
734
735Revision 1.11  2004/01/30 02:12:30  ksekar
736Changed uDNS_ReceiveMsg() to correctly return void.
737
738Revision 1.10  2004/01/29 02:59:17  ksekar
739Unicast DNS: Changed from a resource record oriented question/response
740matching to packet based matching.  New callback architecture allows
741collections of records in a response to be processed differently
742depending on the nature of the request, and allows the same structure
743to be used for internal and client-driven queries with different processing needs.
744
745Revision 1.9  2004/01/28 20:20:45  ksekar
746Unified ActiveQueries and ActiveInternalQueries lists, using a flag to
747demux them.  Check-in includes work-in-progress code, #ifdef'd out.
748
749Revision 1.8  2004/01/28 02:30:07  ksekar
750Added default Search Domains to unicast browsing, controlled via
751Networking sharing prefs pane.  Stopped sending unicast messages on
752every interface.  Fixed unicast resolving via mach-port API.
753
754Revision 1.7  2004/01/27 20:15:22  cheshire
755<rdar://problem/3541288>: Time to prune obsolete code for listening on port 53
756
757Revision 1.6  2004/01/24 23:47:17  cheshire
758Use mDNSOpaque16fromIntVal() instead of shifting and masking
759
760Revision 1.5  2004/01/24 04:59:15  cheshire
761Fixes so that Posix/Linux, OS9, Windows, and VxWorks targets build again
762
763Revision 1.4  2004/01/24 04:19:26  cheshire
764Restore overwritten checkin 1.2
765
766Revision 1.3  2004/01/23 23:23:15  ksekar
767Added TCP support for truncated unicast messages.
768
769Revision 1.2  2004/01/22 03:48:41  cheshire
770Make sure uDNS client doesn't accidentally use query ID zero
771
772Revision 1.1  2003/12/13 03:05:27  ksekar
773<rdar://problem/3192548>: DynDNS: Unicast query of service records
774
775 */
776
777#pragma ident	"%Z%%M%	%I%	%E% SMI"
778
779#include "uDNS.h"
780
781#if(defined(_MSC_VER))
782	// Disable "assignment within conditional expression".
783	// Other compilers understand the convention that if you place the assignment expression within an extra pair
784	// of parentheses, this signals to the compiler that you really intended an assignment and no warning is necessary.
785	// The Microsoft compiler doesn't understand this convention, so in the absense of any other way to signal
786	// to the compiler that the assignment is intentional, we have to just turn this warning off completely.
787	#pragma warning(disable:4706)
788#endif
789
790#define umalloc(x)         mDNSPlatformMemAllocate(x)       // short hands for common routines
791#define ufree(x)           mDNSPlatformMemFree(x)
792#define ubzero(x,y)        mDNSPlatformMemZero(x,y)
793#define umemcpy(x, y, l)   mDNSPlatformMemCopy(y, x, l)  // uses memcpy(2) arg ordering
794
795// Asynchronous operation types
796
797typedef enum
798	{
799	zoneDataResult
800	// other async. operation names go here
801	} AsyncOpResultType;
802
803typedef struct
804	{
805    domainname zoneName;
806    mDNSAddr primaryAddr;
807    mDNSu16 zoneClass;
808    mDNSIPPort llqPort;
809    mDNSIPPort updatePort;
810	} zoneData_t;
811
812// other async. result struct defs go here
813
814typedef struct
815	{
816    AsyncOpResultType type;
817    zoneData_t zoneData;
818    // other async result structs go here
819	} AsyncOpResult;
820
821typedef void AsyncOpCallback(mStatus err, mDNS *const m, void *info, const AsyncOpResult *result);
822
823
824// Private Function Prototypes
825// Note:  In general, functions are ordered such that they do not require forward declarations.
826// However, prototypes are used where cyclic call graphs exist (e.g. foo calls bar, and bar calls
827// foo), or when they aid in the grouping or readability of code (e.g. state machine code that is easier
828// read top-to-bottom.)
829
830mDNSlocal mDNSBool FreeNATInfo(mDNS *m, NATTraversalInfo *n);
831mDNSlocal void hndlTruncatedAnswer(DNSQuestion *question,  const mDNSAddr *src, mDNS *m);
832mDNSlocal mStatus startGetZoneData(domainname *name, mDNS *m, mDNSBool findUpdatePort, mDNSBool findLLQPort, AsyncOpCallback callback, void *callbackInfo);
833mDNSlocal mDNSBool recvLLQResponse(mDNS *m, DNSMessage *msg, const mDNSu8 *end, const mDNSAddr *srcaddr, mDNSIPPort srcport, const mDNSInterfaceID InterfaceID);
834mDNSlocal void sendRecordRegistration(mDNS *const m, AuthRecord *rr);
835mDNSlocal void SendServiceRegistration(mDNS *m, ServiceRecordSet *srs);
836mDNSlocal void SendServiceDeregistration(mDNS *m, ServiceRecordSet *srs);
837mDNSlocal void serviceRegistrationCallback(mStatus err, mDNS *const m, void *srsPtr, const AsyncOpResult *result);
838mDNSlocal void SuspendLLQs(mDNS *m, mDNSBool DeregisterActive);
839mDNSlocal void RestartQueries(mDNS *m);
840mDNSlocal void startLLQHandshake(mDNS *m, LLQ_Info *info, mDNSBool defer);
841mDNSlocal void llqResponseHndlr(mDNS * const m, DNSMessage *msg, const  mDNSu8 *end, DNSQuestion *question, void *context);
842
843// ***************************************************************************
844#if COMPILER_LIKES_PRAGMA_MARK
845#pragma mark - Temporary workaround
846#endif
847
848// 17 Places in this file directly call mDNSPlatformTimeNow(), which is unsafe
849// The platform function is now called mDNSPlatformRawTime(), and
850// mDNSPlatformTimeNow() is defined here as a temporary workaround.
851// This is a gross hack, and after this change has been tested for a while,
852// all these calls should be replaced by simple references to m->timenow
853
854mDNSlocal mDNSs32 mDNSPlatformTimeNow(mDNS *m)
855	{
856	if (m->mDNS_busy && m->timenow) return(m->timenow);
857	LogMsg("ERROR: uDNS.c code executing without holding main mDNS lock");
858
859	// To get a quick and easy stack trace to find out *how* this routine
860	// is being called without holding main mDNS lock, uncomment the line below:
861	// *(long*)0=0;
862
863	return(mDNS_TimeNow(m));
864	}
865
866// ***************************************************************************
867#if COMPILER_LIKES_PRAGMA_MARK
868#pragma mark - General Utility Functions
869#endif
870
871// CountLabels() returns number of labels in name, excluding final root label
872// (e.g. for "apple.com." CountLabels returns 2.)
873mDNSlocal int CountLabels(const domainname *d)
874	{
875	int count = 0;
876	const mDNSu8 *ptr;
877
878	for (ptr = d->c; *ptr; ptr = ptr + ptr[0] + 1) count++;
879	return count;
880	}
881
882mDNSlocal mDNSOpaque16 newMessageID(uDNS_GlobalInfo *u)
883	{
884	static mDNSBool randomized = mDNSfalse;
885
886	if (!randomized) { u->NextMessageID = (mDNSu16)mDNSRandom(0xFFFF); randomized = mDNStrue; }
887	if (u->NextMessageID == 0) u->NextMessageID++;
888	return mDNSOpaque16fromIntVal(u->NextMessageID++);
889	}
890
891// unlink an AuthRecord from a linked list
892mDNSlocal mStatus unlinkAR(AuthRecord **list, AuthRecord *const rr)
893	{
894	while (*list && *list != rr) list = &(*list)->next;
895	if (*list) { *list = rr->next; rr->next = mDNSNULL; return(mStatus_NoError); }
896	LogMsg("ERROR: unlinkAR - no such active record %##s", rr->resrec.name->c);
897	return(mStatus_NoSuchRecord);
898	}
899
900mDNSlocal void unlinkSRS(mDNS *m, ServiceRecordSet *srs)
901	{
902	uDNS_GlobalInfo *u = &m->uDNS_info;
903	ServiceRecordSet **p;
904	NATTraversalInfo *n = u->NATTraversals;
905
906	// verify that no NAT objects reference this service
907	while (n)
908		{
909		if (n->reg.ServiceRegistration == srs)
910			{
911			NATTraversalInfo *tmp = n;
912			n = n->next;
913			LogMsg("ERROR: Unlinking service record set %##s still referenced by NAT traversal object!", srs->RR_SRV.resrec.name->c);
914			FreeNATInfo(m, tmp);
915			}
916		else n = n->next;
917		}
918
919	for (p = &u->ServiceRegistrations; *p; p = &(*p)->next)
920		if (*p == srs)
921			{
922			ExtraResourceRecord *e;
923			*p = srs->next;
924			srs->next = mDNSNULL;
925			for (e=srs->Extras; e; e=e->next)
926				if (unlinkAR(&u->RecordRegistrations, &e->r))
927					LogMsg("unlinkSRS: extra record %##s not found", e->r.resrec.name->c);
928			return;
929			}
930	LogMsg("ERROR: unlinkSRS - SRS not found in ServiceRegistrations list %##s", srs->RR_SRV.resrec.name->c);
931	}
932
933mDNSlocal void LinkActiveQuestion(uDNS_GlobalInfo *u, DNSQuestion *q)
934	{
935	if (uDNS_IsActiveQuery(q, u))
936		{ LogMsg("LinkActiveQuestion - %##s (%d) already in list!", q->qname.c, q->qtype); return; }
937
938	q->next = u->ActiveQueries;
939	u->ActiveQueries = q;
940	}
941
942// set retry timestamp for record with exponential backoff
943// (for service record sets, use RR_SRV as representative for time checks
944mDNSlocal void SetRecordRetry(mDNS *const m, AuthRecord *rr, mStatus SendErr)
945	{
946	rr->LastAPTime = mDNSPlatformTimeNow(m);
947	if (SendErr == mStatus_TransientErr || rr->ThisAPInterval < INIT_UCAST_POLL_INTERVAL)  rr->ThisAPInterval = INIT_UCAST_POLL_INTERVAL;
948	else if (rr->ThisAPInterval*2 <= MAX_UCAST_POLL_INTERVAL)                              rr->ThisAPInterval *= 2;
949	else if (rr->ThisAPInterval != MAX_UCAST_POLL_INTERVAL)                                rr->ThisAPInterval = MAX_UCAST_POLL_INTERVAL;
950	}
951
952
953// ***************************************************************************
954#if COMPILER_LIKES_PRAGMA_MARK
955#pragma mark - Name Server List Management
956#endif
957
958mDNSexport void mDNS_AddDNSServer(mDNS *const m, const mDNSAddr *addr, const domainname *d)
959    {
960    uDNS_GlobalInfo *u = &m->uDNS_info;
961	DNSServer *s, **p = &u->Servers;
962
963	mDNS_Lock(m);
964	if (!d) d = (domainname *)"";
965
966	while (*p)                 // Check if we already have this {server,domain} pair registered
967		{
968		if (mDNSSameAddress(&(*p)->addr, addr) && SameDomainName(&(*p)->domain, d))
969			LogMsg("Note: DNS Server %#a for domain %##s registered more than once", addr, d->c);
970		p=&(*p)->next;
971		}
972
973	// allocate, add to list
974	s = umalloc(sizeof(*s));
975	if (!s) { LogMsg("Error: mDNS_AddDNSServer - malloc"); goto end; }
976	s->addr      = *addr;
977	s->del       = mDNSfalse;
978	s->teststate = DNSServer_Untested;
979	AssignDomainName(&s->domain, d);
980	s->next = mDNSNULL;
981	*p = s;
982
983	end:
984	mDNS_Unlock(m);
985    }
986
987mDNSexport void mDNS_DeleteDNSServers(mDNS *const m)
988    {
989	DNSServer *s;
990	mDNS_Lock(m);
991
992	s = m->uDNS_info.Servers;
993	m->uDNS_info.Servers = mDNSNULL;
994	while (s)
995		{
996		DNSServer *tmp = s;
997		s = s->next;
998		ufree(tmp);
999		}
1000
1001	mDNS_Unlock(m);
1002    }
1003
1004 // ***************************************************************************
1005#if COMPILER_LIKES_PRAGMA_MARK
1006#pragma mark - authorization management
1007#endif
1008
1009mDNSlocal uDNS_AuthInfo *GetAuthInfoForName(const uDNS_GlobalInfo *u, const domainname *name)
1010	{
1011	uDNS_AuthInfo *ptr;
1012	while (name->c[0])
1013		{
1014		for (ptr = u->AuthInfoList; ptr; ptr = ptr->next)
1015			if (SameDomainName(&ptr->zone, name)) return(ptr);
1016		name = (const domainname *)(name->c + 1 + name->c[0]);
1017		}
1018	return mDNSNULL;
1019	}
1020
1021mDNSlocal void DeleteAuthInfoForZone(uDNS_GlobalInfo *u, const domainname *zone)
1022	{
1023	uDNS_AuthInfo *ptr, *prev = mDNSNULL;
1024
1025	for (ptr = u->AuthInfoList; ptr; ptr = ptr->next)
1026		{
1027		if (SameDomainName(&ptr->zone, zone))
1028			{
1029			if (prev) prev->next = ptr->next;
1030			else u->AuthInfoList = ptr->next;
1031			ufree(ptr);
1032			return;
1033			}
1034		prev = ptr;
1035		}
1036	}
1037
1038mDNSexport mStatus mDNS_SetSecretForZone(mDNS *m, const domainname *zone, const domainname *key, const char *sharedSecret)
1039	{
1040	uDNS_AuthInfo *info;
1041	mDNSu8 keybuf[1024];
1042	mDNSs32 keylen;
1043	uDNS_GlobalInfo *u = &m->uDNS_info;
1044	mStatus status = mStatus_NoError;
1045
1046	mDNS_Lock(m);
1047
1048	if (GetAuthInfoForName(u, zone)) DeleteAuthInfoForZone(u, zone);
1049	if (!key) goto exit;
1050
1051	info = (uDNS_AuthInfo*)umalloc(sizeof(*info));
1052	if (!info) { LogMsg("ERROR: umalloc"); status = mStatus_NoMemoryErr; goto exit; }
1053   	ubzero(info, sizeof(*info));
1054	AssignDomainName(&info->zone, zone);
1055	AssignDomainName(&info->keyname, key);
1056
1057	keylen = DNSDigest_Base64ToBin(sharedSecret, keybuf, 1024);
1058	if (keylen < 0)
1059		{
1060		LogMsg("ERROR: mDNS_SetSecretForZone - could not convert shared secret %s from base64", sharedSecret);
1061		ufree(info);
1062		status = mStatus_UnknownErr;
1063		goto exit;
1064		}
1065	DNSDigest_ConstructHMACKey(info, keybuf, (mDNSu32)keylen);
1066
1067    // link into list
1068	info->next = m->uDNS_info.AuthInfoList;
1069	m->uDNS_info.AuthInfoList = info;
1070exit:
1071	mDNS_Unlock(m);
1072	return status;
1073	}
1074
1075 // ***************************************************************************
1076#if COMPILER_LIKES_PRAGMA_MARK
1077#pragma mark - NAT Traversal
1078#endif
1079
1080mDNSlocal mDNSBool DomainContainsLabelString(const domainname *d, const char *str)
1081	{
1082	const domainlabel *l;
1083	domainlabel buf;
1084
1085	if (!MakeDomainLabelFromLiteralString(&buf, str)) return mDNSfalse;
1086
1087	for (l = (const domainlabel *)d; l->c[0]; l = (const domainlabel *)(l->c + l->c[0]+1))
1088		if (SameDomainLabel(l->c, buf.c)) return mDNStrue;
1089	return mDNSfalse;
1090	}
1091
1092// allocate struct, link into global list, initialize
1093mDNSlocal NATTraversalInfo *AllocNATInfo(mDNS *const m, NATOp_t op, NATResponseHndlr callback)
1094	{
1095	uDNS_GlobalInfo *u = &m->uDNS_info;
1096	NATTraversalInfo *info = umalloc(sizeof(NATTraversalInfo));
1097	if (!info) { LogMsg("ERROR: malloc"); return mDNSNULL; }
1098	ubzero(info, sizeof(NATTraversalInfo));
1099	info->next = u->NATTraversals;
1100	u->NATTraversals = info;
1101	info->retry = mDNSPlatformTimeNow(m) + NATMAP_INIT_RETRY;
1102	info->op = op;
1103	info->state = NATState_Init;
1104	info->ReceiveResponse = callback;
1105	info->PublicPort.NotAnInteger = 0;
1106	info->Router = u->Router;
1107	return info;
1108	}
1109
1110// unlink from list, deallocate
1111mDNSlocal mDNSBool FreeNATInfo(mDNS *m, NATTraversalInfo *n)
1112	{
1113	NATTraversalInfo *ptr, *prev = mDNSNULL;
1114	ServiceRecordSet *s = m->uDNS_info.ServiceRegistrations;
1115
1116	// Verify that object is not referenced by any services
1117	while (s)
1118		{
1119		if (s->uDNS_info.NATinfo == n)
1120			{
1121			LogMsg("Error: Freeing NAT info object still referenced by Service Record Set %##s!", s->RR_SRV.resrec.name->c);
1122			s->uDNS_info.NATinfo = mDNSNULL;
1123			}
1124		s = s->next;
1125		}
1126
1127	if (n == m->uDNS_info.LLQNatInfo) m->uDNS_info.LLQNatInfo = mDNSNULL;
1128	ptr = m->uDNS_info.NATTraversals;
1129	while (ptr)
1130		{
1131		if (ptr == n)
1132			{
1133			if (prev) prev->next = ptr->next;
1134			else m->uDNS_info.NATTraversals = ptr->next;
1135			ufree(n);
1136			return mDNStrue;
1137			}
1138		prev = ptr;
1139		ptr = ptr->next;
1140		}
1141	LogMsg("FreeNATInfo: NATTraversalInfo not found in list");
1142	return mDNSfalse;
1143	}
1144
1145mDNSlocal void SendNATMsg(NATTraversalInfo *info, mDNS *m)
1146	{
1147	mStatus err;
1148	uDNS_GlobalInfo *u = &m->uDNS_info;
1149
1150	if (info->state != NATState_Request && info->state != NATState_Refresh)
1151		{ LogMsg("SendNATMsg: Bad state %d", info->state); return; }
1152
1153	if (u->Router.ip.v4.NotAnInteger)
1154		{
1155		// send msg if we have a router
1156		const mDNSu8 *end = (mDNSu8 *)&info->request;
1157		if (info->op == NATOp_AddrRequest) end += sizeof(NATAddrRequest);
1158		else end += sizeof(NATPortMapRequest);
1159
1160		err = mDNSPlatformSendUDP(m, &info->request, end, 0, &u->Router, NATPMPPort);
1161		if (!err) (info->ntries++);  // don't increment attempt counter if the send failed
1162		}
1163
1164	// set retry
1165	if (info->RetryInterval < NATMAP_INIT_RETRY) info->RetryInterval = NATMAP_INIT_RETRY;
1166	else if (info->RetryInterval * 2 > NATMAP_MAX_RETRY) info->RetryInterval = NATMAP_MAX_RETRY;
1167	else info->RetryInterval *= 2;
1168	info->retry = mDNSPlatformTimeNow(m) + info->RetryInterval;
1169	}
1170
1171mDNSlocal mDNSBool ReceiveNATAddrResponse(NATTraversalInfo *n, mDNS *m, mDNSu8 *pkt, mDNSu16 len)
1172	{
1173	mStatus err = mStatus_NoError;
1174	AuthRecord *rr = mDNSNULL;
1175	NATAddrReply *response = (NATAddrReply *)pkt;
1176	mDNSAddr addr;
1177
1178	if (n->state != NATState_Request)
1179		{
1180		LogMsg("ReceiveNATAddrResponse: bad state %d", n->state);
1181		return mDNSfalse;
1182		}
1183
1184	rr = n->reg.RecordRegistration;
1185	if (!rr)
1186		{
1187		LogMsg("ReceiveNATAddrResponse: registration cancelled");
1188		return mDNSfalse;
1189		}
1190
1191	addr.type = mDNSAddrType_IPv4;
1192	addr.ip.v4 = rr->resrec.rdata->u.ipv4;
1193
1194	if (!pkt) // timeout
1195		{
1196#ifdef _LEGACY_NAT_TRAVERSAL_
1197		err = LNT_GetPublicIP(&addr.ip.v4);
1198		if (err) goto end;
1199		else n->state = NATState_Legacy;
1200#else
1201		debugf("ReceiveNATAddrResponse: timeout");
1202		err = mStatus_NATTraversal;
1203		goto end;
1204#endif // _LEGACY_NAT_TRAVERSAL_
1205		}
1206	else
1207		{
1208		if (len < sizeof(*response))
1209			{
1210			LogMsg("ReceiveNATAddrResponse: response too short (%d bytes)", len);
1211			return mDNSfalse;
1212			}
1213		if (response->vers != NATMAP_VERS)
1214			{
1215			LogMsg("ReceiveNATAddrResponse: received  version %d (expect version %d)", pkt[0], NATMAP_VERS);
1216			return mDNSfalse;
1217			}
1218		if (response->opcode != (NATOp_AddrRequest | NATMAP_RESPONSE_MASK))
1219			{
1220			LogMsg("ReceiveNATAddrResponse: bad response code %d", response->opcode);
1221			return mDNSfalse;
1222			}
1223		if (response->err.NotAnInteger)
1224			{ LogMsg("ReceiveAddrResponse: received error %d", mDNSVal16(response->err)); err = mStatus_NATTraversal; goto end; }
1225
1226		addr.ip.v4 = response->PubAddr;
1227		n->state = NATState_Established;
1228		}
1229
1230	if (IsPrivateV4Addr(&addr))
1231		{
1232		LogMsg("ReceiveNATAddrResponse: Double NAT");
1233		err = mStatus_DoubleNAT;
1234		goto end;
1235		}
1236
1237	end:
1238	if (err)
1239		{
1240		FreeNATInfo(m, n);
1241		if (rr)
1242			{
1243			rr->uDNS_info.NATinfo = mDNSNULL;
1244			rr->uDNS_info.state = regState_Unregistered;    // note that rr is not yet in global list
1245			rr->RecordCallback(m, rr, mStatus_NATTraversal);
1246			// note - unsafe to touch rr after callback
1247			}
1248		return mDNStrue;
1249		}
1250	else LogOperation("Received public IP address %d.%d.%d.%d from NAT.", addr.ip.v4.b[0], addr.ip.v4.b[1], addr.ip.v4.b[2], addr.ip.v4.b[3]);
1251	rr->resrec.rdata->u.ipv4 = addr.ip.v4;  // replace rdata w/ public address
1252	uDNS_RegisterRecord(m, rr);
1253	return mDNStrue;
1254	}
1255
1256
1257mDNSlocal void StartGetPublicAddr(mDNS *m, AuthRecord *AddressRec)
1258	{
1259	NATAddrRequest *req;
1260	uDNS_GlobalInfo *u = &m->uDNS_info;
1261
1262	NATTraversalInfo *info = AllocNATInfo(m, NATOp_AddrRequest, ReceiveNATAddrResponse);
1263	if (!info) { uDNS_RegisterRecord(m, AddressRec); return; }
1264	AddressRec->uDNS_info.NATinfo = info;
1265	info->reg.RecordRegistration = AddressRec;
1266	info->state = NATState_Request;
1267
1268    // format message
1269	req = &info->request.AddrReq;
1270	req->vers = NATMAP_VERS;
1271	req->opcode = NATOp_AddrRequest;
1272
1273	if (!u->Router.ip.v4.NotAnInteger)
1274		{
1275		debugf("No router.  Will retry NAT traversal in %ld ticks", NATMAP_INIT_RETRY);
1276		return;
1277		}
1278
1279	SendNATMsg(info, m);
1280	}
1281
1282
1283mDNSlocal void RefreshNATMapping(NATTraversalInfo *n, mDNS *m)
1284	{
1285	n->state = NATState_Refresh;
1286	n->RetryInterval = NATMAP_INIT_RETRY;
1287	n->ntries = 0;
1288	SendNATMsg(n, m);
1289	}
1290
1291mDNSlocal void LLQNatMapComplete(mDNS *m)
1292	{
1293	uDNS_GlobalInfo *u = &m->uDNS_info;
1294	LLQ_Info *llqInfo;
1295	NATTraversalInfo *n = u->LLQNatInfo;
1296
1297	if (!n) { LogMsg("Error: LLQNatMapComplete called with NULL LLQNatInfo"); return; }
1298	if (n->state != NATState_Established && n->state != NATState_Legacy && n->state != NATState_Error)
1299		{ LogMsg("LLQNatMapComplete - bad nat state %d", n->state); return; }
1300
1301	u->CurrentQuery = u->ActiveQueries;
1302	while (u->CurrentQuery)
1303		{
1304		DNSQuestion *q = u->CurrentQuery;
1305		u->CurrentQuery = u->CurrentQuery->next;
1306		llqInfo = q->uDNS_info.llq;
1307		if (q->LongLived && llqInfo->state == LLQ_NatMapWait)
1308			{
1309			if (n->state == NATState_Error)
1310				{
1311				llqInfo->NATMap = mDNSfalse;
1312				llqInfo->question->uDNS_info.responseCallback = llqResponseHndlr;
1313				llqInfo->state = LLQ_Poll;
1314				llqInfo->question->LastQTime = mDNSPlatformTimeNow(m) - (2 * INIT_UCAST_POLL_INTERVAL);  // trigger immediate poll
1315				llqInfo->question->ThisQInterval = INIT_UCAST_POLL_INTERVAL;
1316				}
1317			else { llqInfo->state = LLQ_GetZoneInfo; startLLQHandshake(m, llqInfo, mDNSfalse); }
1318			}
1319		}
1320	}
1321
1322mDNSlocal mDNSBool ReceivePortMapReply(NATTraversalInfo *n, mDNS *m, mDNSu8 *pkt, mDNSu16 len)
1323	{
1324	ServiceRecordSet *srs = n->reg.ServiceRegistration;
1325	mDNSIPPort priv = srs ? srs->RR_SRV.resrec.rdata->u.srv.port : m->UnicastPort4;
1326	mDNSu32 lease;
1327	mDNSBool deletion = !n->request.PortReq.lease.NotAnInteger;
1328	NATPortMapReply *reply = (NATPortMapReply *)pkt;
1329	mDNSu8 *service = srs ? srs->RR_SRV.resrec.name->c : (mDNSu8 *)"\016LLQ event port";
1330
1331	if (n->state != NATState_Request && n->state != NATState_Refresh)
1332		{ LogMsg("ReceivePortMapReply (%##s): bad state %d", service, n->state);  return mDNSfalse; }
1333
1334	if (!pkt && !deletion) // timeout
1335		{
1336#ifdef _LEGACY_NAT_TRAVERSAL_
1337		mDNSIPPort pub;
1338		int ntries = 0;
1339		mStatus err;
1340		mDNSBool tcp = (srs && DomainContainsLabelString(srs->RR_PTR.resrec.name, "_tcp"));
1341
1342		pub = priv; // initially request priv == pub
1343		while (1)
1344			{
1345			err = LNT_MapPort(priv, pub, tcp);
1346			if (!err)
1347				{
1348				n->PublicPort = pub;
1349				n->state = NATState_Legacy;
1350				goto end;
1351				}
1352			else if (err != mStatus_AlreadyRegistered || ++ntries > LEGACY_NATMAP_MAX_TRIES)
1353				{
1354				n->state = NATState_Error;
1355				goto end;
1356				}
1357			else
1358				{
1359				// the mapping we want is taken - try a random port
1360				mDNSu16 RandPort = mDNSRandom(DYN_PORT_MAX - DYN_PORT_MIN) + DYN_PORT_MIN;
1361				pub = mDNSOpaque16fromIntVal(RandPort);
1362				}
1363			}
1364#else
1365		goto end;
1366#endif // _LEGACY_NAT_TRAVERSAL_
1367		}
1368
1369	if (len < sizeof(*reply)) { LogMsg("ReceivePortMapReply: response too short (%d bytes)", len); return mDNSfalse; }
1370	if (reply->vers != NATMAP_VERS) { LogMsg("ReceivePortMapReply: received  version %d (expect version %d)", pkt[0], NATMAP_VERS);  return mDNSfalse; }
1371	if (reply->opcode != (n->op | NATMAP_RESPONSE_MASK)) { LogMsg("ReceivePortMapReply: bad response code %d", pkt[1]); return mDNSfalse; }
1372	if (reply->err.NotAnInteger) { LogMsg("ReceivePortMapReply: received error %d", mDNSVal16(reply->err));  return mDNSfalse; }
1373	if (priv.NotAnInteger != reply->priv.NotAnInteger) return mDNSfalse;  // packet does not match this request
1374
1375	if (!srs && n != m->uDNS_info.LLQNatInfo)
1376		{
1377		LogMsg("ReceivePortMapReply: registration cancelled");  //!!!KRS change to debugf before checkin
1378		FreeNATInfo(m, n);
1379		return mDNStrue;
1380		}
1381
1382	if (deletion) { n->state = NATState_Deleted; return mDNStrue; }
1383
1384	lease = (mDNSu32)mDNSVal32(reply->lease);
1385	if (lease > 0x70000000UL / mDNSPlatformOneSecond) lease = 0x70000000UL / mDNSPlatformOneSecond;
1386
1387	if (n->state == NATState_Refresh && reply->pub.NotAnInteger != n->PublicPort.NotAnInteger)
1388		LogMsg("ReceivePortMapReply: NAT refresh changed public port from %d to %d", mDNSVal16(n->PublicPort), mDNSVal16(reply->pub));
1389        // this should never happen
1390	    // !!!KRS to be defensive, use SRVChanged flag on service and deregister here
1391
1392	n->PublicPort = reply->pub;
1393	if (reply->pub.NotAnInteger != n->request.PortReq.pub.NotAnInteger) n->request.PortReq.pub = reply->pub; // set message buffer for refreshes
1394
1395	n->retry = mDNSPlatformTimeNow(m) + ((mDNSs32)lease * mDNSPlatformOneSecond / 2);  // retry half way to expiration
1396
1397	if (n->state == NATState_Refresh) { n->state = NATState_Established; return mDNStrue; }
1398	n->state = NATState_Established;
1399
1400	end:
1401	if (n->state != NATState_Established && n->state != NATState_Legacy)
1402		{
1403		LogMsg("NAT Port Mapping (%##s): timeout", service);
1404		if (pkt) LogMsg("!!! timeout with non-null packet");
1405		n->state = NATState_Error;
1406		if (srs)
1407			{
1408			uDNS_HostnameInfo *hi = m->uDNS_info.Hostnames;
1409			while (hi)
1410				{
1411				if (hi->arv6 && (hi->arv6->uDNS_info.state == regState_Registered || hi->arv6->uDNS_info.state == regState_Refresh)) break;
1412				else hi = hi->next;
1413				}
1414
1415			if (hi)
1416				{
1417				debugf("Port map failed for service %##s - using IPv6 service target", service);
1418				srs->uDNS_info.NATinfo = mDNSNULL;
1419				FreeNATInfo(m, n);
1420				goto register_service;
1421				}
1422			else srs->uDNS_info.state = regState_NATError;
1423			}
1424		else LLQNatMapComplete(m);
1425		return mDNStrue;
1426		}
1427	else LogOperation("Mapped private port %d to public port %d", mDNSVal16(priv), mDNSVal16(n->PublicPort));
1428
1429	if (!srs) { LLQNatMapComplete(m); return mDNStrue; }
1430
1431	register_service:
1432	if (srs->uDNS_info.ns.ip.v4.NotAnInteger) SendServiceRegistration(m, srs);  // non-zero server address means we already have necessary zone data to send update
1433	else
1434		{
1435		srs->uDNS_info.state = regState_FetchingZoneData;
1436		startGetZoneData(srs->RR_SRV.resrec.name, m, mDNStrue, mDNSfalse, serviceRegistrationCallback, srs);
1437		}
1438	return mDNStrue;
1439	}
1440
1441mDNSlocal void FormatPortMaprequest(NATTraversalInfo *info, mDNSIPPort port)
1442	{
1443	NATPortMapRequest *req = &info->request.PortReq;
1444
1445	req->vers = NATMAP_VERS;
1446	req->opcode = info->op;
1447	req->unused.NotAnInteger = 0;
1448	req->priv = port;
1449	req->pub = port;
1450	req->lease = mDNSOpaque32fromIntVal(NATMAP_DEFAULT_LEASE);
1451	}
1452
1453mDNSlocal void SendInitialPMapReq(mDNS *m, NATTraversalInfo *info)
1454	{
1455	if (!m->uDNS_info.Router.ip.v4.NotAnInteger)
1456		{
1457		debugf("No router.  Will retry NAT traversal in %ld seconds", NATMAP_INIT_RETRY);
1458		info->retry = mDNSPlatformTimeNow(m) + NATMAP_INIT_RETRY;
1459		info->RetryInterval = NATMAP_INIT_RETRY;
1460		return;
1461		}
1462    SendNATMsg(info, m);
1463	return;
1464	}
1465
1466mDNSlocal void StartNATPortMap(mDNS *m, ServiceRecordSet *srs)
1467	{
1468	NATOp_t op;
1469	NATTraversalInfo *info;
1470
1471   	if (DomainContainsLabelString(srs->RR_PTR.resrec.name, "_tcp")) op = NATOp_MapTCP;
1472	else if (DomainContainsLabelString(srs->RR_PTR.resrec.name, "_udp")) op = NATOp_MapUDP;
1473	else { LogMsg("StartNATPortMap: could not determine transport protocol of service %##s", srs->RR_SRV.resrec.name->c); goto error; }
1474
1475	if (srs->uDNS_info.NATinfo) { LogMsg("Error: StartNATPortMap - NAT info already initialized!");  FreeNATInfo(m, srs->uDNS_info.NATinfo); }
1476	info = AllocNATInfo(m, op, ReceivePortMapReply);
1477	srs->uDNS_info.NATinfo = info;
1478	info->reg.ServiceRegistration = srs;
1479	info->state = NATState_Request;
1480
1481	FormatPortMaprequest(info, srs->RR_SRV.resrec.rdata->u.srv.port);
1482	SendInitialPMapReq(m, info);
1483	return;
1484
1485	error:
1486	startGetZoneData(srs->RR_SRV.resrec.name, m, mDNStrue, mDNSfalse, serviceRegistrationCallback, srs);
1487	}
1488
1489mDNSlocal void DeleteNATPortMapping(mDNS *m, NATTraversalInfo *nat, ServiceRecordSet *srs)
1490	{
1491	if (nat->state == NATState_Established)  // let other edge-case states expire for simplicity
1492		{
1493		// zero lease
1494		nat->request.PortReq.lease.NotAnInteger = 0;
1495		nat->state = NATState_Request;
1496		SendNATMsg(nat, m);
1497		}
1498#ifdef _LEGACY_NAT_TRAVERSAL_
1499	else if (nat->state == NATState_Legacy)
1500		{
1501		mStatus err = mStatus_NoError;
1502		mDNSBool tcp = srs ? DomainContainsLabelString(srs->RR_PTR.resrec.name, "_tcp") : mDNSfalse;
1503		err = LNT_UnmapPort(nat->PublicPort, tcp);
1504		if (err) LogMsg("Legacy NAT Traversal - unmap request failed with error %ld", err);
1505		}
1506#else
1507	(void)srs; // unused
1508#endif // _LEGACY_NAT_TRAVERSAL_
1509	}
1510
1511mDNSlocal void StartLLQNatMap(mDNS *m)
1512	{
1513	NATTraversalInfo *info = AllocNATInfo(m, NATOp_MapUDP, ReceivePortMapReply);
1514	uDNS_GlobalInfo *u = &m->uDNS_info;
1515
1516	u->LLQNatInfo = info;
1517
1518	info->reg.RecordRegistration = mDNSNULL;
1519	info->reg.ServiceRegistration = mDNSNULL;
1520    info->state = NATState_Request;
1521	FormatPortMaprequest(info, m->UnicastPort4);
1522    SendInitialPMapReq(m, info);
1523	return;
1524	}
1525
1526// if LLQ NAT context unreferenced, delete the mapping
1527mDNSlocal void CheckForUnreferencedLLQMapping(mDNS *m)
1528	{
1529	NATTraversalInfo *nat = m->uDNS_info.LLQNatInfo;
1530	DNSQuestion *q;
1531
1532	if (!nat) return;
1533
1534	for (q = m->uDNS_info.ActiveQueries; q; q = q->next)
1535		if (q->LongLived && q->uDNS_info.llq->NATMap) return;
1536
1537	//to avoid race condition if we need to recreate before this finishes, we do one-shot deregistration
1538	if (nat->state == NATState_Established || nat->state == NATState_Legacy)
1539		DeleteNATPortMapping(m, nat, mDNSNULL); // for simplicity we allow other states to expire
1540	FreeNATInfo(m, nat); // note: this clears the global LLQNatInfo pointer
1541	}
1542
1543 // ***************************************************************************
1544#if COMPILER_LIKES_PRAGMA_MARK
1545#pragma mark - host name and interface management
1546#endif
1547
1548// if we ever want to refine support for multiple hostnames, we can add logic matching service names to a particular hostname
1549// for now, we grab the first registered DynDNS name, if any, or a static name we learned via a reverse-map query
1550mDNSlocal mDNSBool GetServiceTarget(uDNS_GlobalInfo *u, AuthRecord *srv, domainname *dst)
1551	{
1552	uDNS_HostnameInfo *hi = u->Hostnames;
1553	(void)srv;  // unused
1554
1555	dst->c[0] = 0;
1556	while (hi)
1557		{
1558		if (hi->arv4 && (hi->arv4->uDNS_info.state == regState_Registered || hi->arv4->uDNS_info.state == regState_Refresh))
1559			{
1560			AssignDomainName(dst, hi->arv4->resrec.name);
1561			return mDNStrue;
1562			}
1563		if (hi->arv6 && (hi->arv6->uDNS_info.state == regState_Registered || hi->arv6->uDNS_info.state == regState_Refresh))
1564			{
1565			AssignDomainName(dst, hi->arv4->resrec.name);
1566			return mDNStrue;
1567			}
1568		hi = hi->next;
1569		}
1570
1571	if (u->StaticHostname.c[0]) { AssignDomainName(dst, &u->StaticHostname); return mDNStrue; }
1572	return mDNSfalse;
1573	}
1574
1575mDNSlocal void UpdateSRV(mDNS *m, ServiceRecordSet *srs)
1576	{
1577	uDNS_GlobalInfo *u = &m->uDNS_info;
1578	ExtraResourceRecord *e;
1579
1580	// Target change if:
1581	// We have a target and were previously waiting for one, or
1582	// We had a target and no longer do, or
1583	// The target has changed
1584
1585	domainname newtarget;
1586	domainname *curtarget = &srs->RR_SRV.resrec.rdata->u.srv.target;
1587	mDNSBool HaveTarget = GetServiceTarget(u, &srs->RR_SRV, &newtarget);
1588	mDNSBool TargetChanged = (HaveTarget && srs->uDNS_info.state == regState_NoTarget) || (curtarget->c[0] && !HaveTarget) || !SameDomainName(curtarget, &newtarget);
1589	mDNSBool HaveZoneData = srs->uDNS_info.ns.ip.v4.NotAnInteger ? mDNStrue : mDNSfalse;
1590
1591	// Nat state change if:
1592	// We were behind a NAT, and now we are behind a new NAT, or
1593	// We're not behind a NAT but our port was previously mapped to a different public port
1594	// We were not behind a NAT and now we are
1595
1596	NATTraversalInfo *nat = srs->uDNS_info.NATinfo;
1597	mDNSIPPort port = srs->RR_SRV.resrec.rdata->u.srv.port;
1598	mDNSBool NATChanged = mDNSfalse;
1599	mDNSBool NowBehindNAT = port.NotAnInteger && IsPrivateV4Addr(&u->AdvertisedV4);
1600	mDNSBool WereBehindNAT = nat != mDNSNULL;
1601	mDNSBool NATRouterChanged = nat && nat->Router.ip.v4.NotAnInteger != u->Router.ip.v4.NotAnInteger;
1602	mDNSBool PortWasMapped = nat && (nat->state == NATState_Established || nat->state == NATState_Legacy) && nat->PublicPort.NotAnInteger != port.NotAnInteger;
1603
1604	if (WereBehindNAT && NowBehindNAT && NATRouterChanged) NATChanged = mDNStrue;
1605	else if (!NowBehindNAT && PortWasMapped)               NATChanged = mDNStrue;
1606	else if (!WereBehindNAT && NowBehindNAT)               NATChanged = mDNStrue;
1607
1608	if (!TargetChanged && !NATChanged) return;
1609
1610	debugf("UpdateSRV (%##s) HadZoneData=%d, TargetChanged=%d, HaveTarget=%d, NowBehindNAT=%d, WereBehindNAT=%d, NATRouterChanged=%d, PortWasMapped=%d",
1611		   srs->RR_SRV.resrec.name->c,  HaveZoneData, TargetChanged, HaveTarget, NowBehindNAT, WereBehindNAT, NATRouterChanged, PortWasMapped);
1612
1613	switch(srs->uDNS_info.state)
1614		{
1615		case regState_FetchingZoneData:
1616		case regState_Cancelled:
1617		case regState_DeregPending:
1618		case regState_DeregDeferred:
1619		case regState_Unregistered:
1620		case regState_NATMap:
1621		case regState_ExtraQueued:
1622			// In these states, the SRV has either not yet been registered (it will get up-to-date information when it is)
1623			// or is in the process of, or has already been, deregistered
1624			return;
1625
1626		case regState_Pending:
1627		case regState_Refresh:
1628		case regState_UpdatePending:
1629			// let the in-flight operation complete before updating
1630			srs->uDNS_info.SRVUpdateDeferred = mDNStrue;
1631			return;
1632
1633		case regState_NATError:
1634			if (!NATChanged) return;
1635			// if nat changed, register if we have a target (below)
1636
1637		case regState_NoTarget:
1638			if (HaveTarget)
1639				{
1640				debugf("UpdateSRV: %s service %##s", HaveZoneData ? (NATChanged && NowBehindNAT ? "Starting Port Map for" : "Registering") : "Getting Zone Data for", srs->RR_SRV.resrec.name->c);
1641				if (!HaveZoneData)
1642					{
1643					srs->uDNS_info.state = regState_FetchingZoneData;
1644					startGetZoneData(srs->RR_SRV.resrec.name, m, mDNStrue, mDNSfalse, serviceRegistrationCallback, srs);
1645					}
1646				else
1647					{
1648					if (nat && (NATChanged || !NowBehindNAT)) { srs->uDNS_info.NATinfo = mDNSNULL; FreeNATInfo(m, nat); }
1649					if (NATChanged && NowBehindNAT) { srs->uDNS_info.state = regState_NATMap; StartNATPortMap(m, srs); }
1650					else SendServiceRegistration(m, srs);
1651					}
1652				}
1653			return;
1654
1655		case regState_Registered:
1656			// target or nat changed.  deregister service.  upon completion, we'll look for a new target
1657			debugf("UpdateSRV: SRV record changed for service %##s - deregistering (will re-register with new SRV)",  srs->RR_SRV.resrec.name->c);
1658			for (e = srs->Extras; e; e = e->next) e->r.uDNS_info.state = regState_ExtraQueued;  // extra will be re-registed if the service is re-registered
1659			srs->uDNS_info.SRVChanged = mDNStrue;
1660			SendServiceDeregistration(m, srs);
1661			return;
1662		}
1663	}
1664
1665mDNSlocal void UpdateSRVRecords(mDNS *m)
1666	{
1667	ServiceRecordSet *srs;
1668
1669	for (srs = m->uDNS_info.ServiceRegistrations; srs; srs = srs->next) UpdateSRV(m, srs);
1670	}
1671
1672mDNSlocal void HostnameCallback(mDNS *const m, AuthRecord *const rr, mStatus result)
1673	{
1674	uDNS_HostnameInfo *hi = (uDNS_HostnameInfo *)rr->RecordContext;
1675
1676	if (result == mStatus_MemFree)
1677		{
1678		if (hi)
1679			{
1680			if      (hi->arv4 == rr)                hi->arv4 = mDNSNULL;
1681			else if (hi->arv4 == rr)                hi->arv6 = mDNSNULL;
1682			rr->RecordContext = mDNSNULL;
1683			if (!hi->arv4 && !hi->arv6) ufree(hi);  // free hi when both v4 and v6 AuthRecs deallocated
1684			}
1685		ufree(rr);
1686		return;
1687		}
1688
1689	if (result)
1690		{
1691		// don't unlink or free - we can retry when we get a new address/router
1692		if (rr->resrec.rrtype == kDNSType_A)
1693			LogMsg("HostnameCallback: Error %ld for registration of %##s IP %.4a", result, rr->resrec.name->c, &rr->resrec.rdata->u.ipv4);
1694		else
1695			LogMsg("HostnameCallback: Error %ld for registration of %##s IP %.16a", result, rr->resrec.name->c, &rr->resrec.rdata->u.ipv6);
1696		if (!hi) { ufree(rr); return; }
1697		if (rr->uDNS_info.state != regState_Unregistered) LogMsg("Error: HostnameCallback invoked with error code for record not in regState_Unregistered!");
1698
1699		if ((!hi->arv4 || hi->arv4->uDNS_info.state == regState_Unregistered) &&
1700			(!hi->arv6 || hi->arv6->uDNS_info.state == regState_Unregistered))
1701			{
1702			// only deliver status if both v4 and v6 fail
1703			rr->RecordContext = (void *)hi->StatusContext;
1704			if (hi->StatusCallback)
1705				hi->StatusCallback(m, rr, result); // client may NOT make API calls here
1706			rr->RecordContext = (void *)hi;
1707			}
1708		return;
1709		}
1710	// register any pending services that require a target
1711	UpdateSRVRecords(m);
1712
1713	// Deliver success to client
1714	if (!hi) { LogMsg("HostnameCallback invoked with orphaned address record"); return; }
1715	if (rr->resrec.rrtype == kDNSType_A)
1716		LogMsg("Registered hostname %##s IP %.4a", rr->resrec.name->c, &rr->resrec.rdata->u.ipv4);
1717	else
1718		LogMsg("Registered hostname %##s IP %.16a", rr->resrec.name->c, &rr->resrec.rdata->u.ipv6);
1719
1720	rr->RecordContext = (void *)hi->StatusContext;
1721	if (hi->StatusCallback)
1722		hi->StatusCallback(m, rr, result); // client may NOT make API calls here
1723	rr->RecordContext = (void *)hi;
1724	}
1725
1726// register record or begin NAT traversal
1727mDNSlocal void AdvertiseHostname(mDNS *m, uDNS_HostnameInfo *h)
1728	{
1729	uDNS_GlobalInfo *u = &m->uDNS_info;
1730
1731	if (u->AdvertisedV4.ip.v4.NotAnInteger && h->arv4->uDNS_info.state == regState_Unregistered)
1732		{
1733		if (IsPrivateV4Addr(&u->AdvertisedV4))
1734			StartGetPublicAddr(m, h->arv4);
1735		else
1736			{
1737			LogMsg("Advertising %##s IP %.4a", h->arv4->resrec.name->c, &u->AdvertisedV4.ip.v4);
1738			uDNS_RegisterRecord(m, h->arv4);
1739			}
1740		}
1741	if (u->AdvertisedV6.ip.v6.b[0] && h->arv6->uDNS_info.state == regState_Unregistered)
1742		{
1743		LogMsg("Advertising %##s IP %.16a", h->arv4->resrec.name->c, &u->AdvertisedV6.ip.v6);
1744		uDNS_RegisterRecord(m, h->arv6);
1745		}
1746	}
1747
1748mDNSlocal void FoundStaticHostname(mDNS *const m, DNSQuestion *question, const ResourceRecord *const answer, mDNSBool AddRecord)
1749	{
1750	const domainname *pktname = &answer->rdata->u.name;
1751	domainname *storedname = &m->uDNS_info.StaticHostname;
1752	uDNS_HostnameInfo *h = m->uDNS_info.Hostnames;
1753
1754	(void)question;
1755
1756	debugf("FoundStaticHostname: %##s -> %##s (%s)", question->qname.c, answer->rdata->u.name.c, AddRecord ? "added" : "removed");
1757	if (AddRecord && !SameDomainName(pktname, storedname))
1758		{
1759		AssignDomainName(storedname, pktname);
1760		while (h)
1761			{
1762			if ((h->arv4 && (h->arv4->uDNS_info.state == regState_FetchingZoneData || h->arv4->uDNS_info.state == regState_Pending || h->arv4->uDNS_info.state == regState_NATMap)) ||
1763			    (h->arv6 && (h->arv6->uDNS_info.state == regState_FetchingZoneData || h->arv6->uDNS_info.state == regState_Pending)))
1764				{
1765				// if we're in the process of registering a dynamic hostname, delay SRV update so we don't have to reregister services if the dynamic name succeeds
1766				m->uDNS_info.DelaySRVUpdate = mDNStrue;
1767				m->uDNS_info.NextSRVUpdate = mDNSPlatformTimeNow(m) + (5 * mDNSPlatformOneSecond);
1768				return;
1769				}
1770			h = h->next;
1771			}
1772		UpdateSRVRecords(m);
1773		}
1774	else if (!AddRecord && SameDomainName(pktname, storedname))
1775		{
1776		storedname->c[0] = 0;
1777		UpdateSRVRecords(m);
1778		}
1779	}
1780
1781mDNSlocal void GetStaticHostname(mDNS *m)
1782	{
1783	char buf[MAX_ESCAPED_DOMAIN_NAME];
1784	DNSQuestion *q = &m->uDNS_info.ReverseMap;
1785	mDNSu8 *ip = m->uDNS_info.AdvertisedV4.ip.v4.b;
1786	mStatus err;
1787
1788	if (m->uDNS_info.ReverseMapActive)
1789		{
1790		uDNS_StopQuery(m, q);
1791		m->uDNS_info.ReverseMapActive = mDNSfalse;
1792		}
1793
1794	m->uDNS_info.StaticHostname.c[0] = 0;
1795	if (!m->uDNS_info.AdvertisedV4.ip.v4.NotAnInteger) return;
1796	ubzero(q, sizeof(*q));
1797	mDNS_snprintf(buf, MAX_ESCAPED_DOMAIN_NAME, "%d.%d.%d.%d.in-addr.arpa.", ip[3], ip[2], ip[1], ip[0]);
1798    if (!MakeDomainNameFromDNSNameString(&q->qname, buf)) { LogMsg("Error: GetStaticHostname - bad name %s", buf); return; }
1799
1800	q->InterfaceID      = mDNSInterface_Any;
1801    q->Target           = zeroAddr;
1802    q->qtype            = kDNSType_PTR;
1803    q->qclass           = kDNSClass_IN;
1804    q->LongLived        = mDNSfalse;
1805    q->ExpectUnique     = mDNSfalse;
1806    q->ForceMCast       = mDNSfalse;
1807    q->QuestionCallback = FoundStaticHostname;
1808    q->QuestionContext  = mDNSNULL;
1809
1810	err = uDNS_StartQuery(m, q);
1811	if (err) LogMsg("Error: GetStaticHostname - StartQuery returned error %d", err);
1812	else m->uDNS_info.ReverseMapActive = mDNStrue;
1813	}
1814
1815mDNSlocal void AssignHostnameInfoAuthRecord(mDNS *m, uDNS_HostnameInfo *hi, int type)
1816	{
1817	AuthRecord **dst = (type == mDNSAddrType_IPv4 ? &hi->arv4 : &hi->arv6);
1818	AuthRecord *ar =  umalloc(sizeof(*ar));
1819	uDNS_GlobalInfo *u = &m->uDNS_info;
1820
1821	if (type != mDNSAddrType_IPv4 && type != mDNSAddrType_IPv6) { LogMsg("ERROR: AssignHostnameInfoAuthRecord - bad type %d", type); return; }
1822	if (!ar) { LogMsg("ERROR: AssignHostnameInfoAuthRecord - malloc"); return; }
1823
1824	mDNS_SetupResourceRecord(ar, mDNSNULL, 0, type == mDNSAddrType_IPv4 ? kDNSType_A : kDNSType_AAAA,  1, kDNSRecordTypeKnownUnique, HostnameCallback, hi);
1825	AssignDomainName(ar->resrec.name, &hi->fqdn);
1826
1827	// only set RData if we have a valid IP
1828	if (type == mDNSAddrType_IPv4 && u->AdvertisedV4.ip.v4.NotAnInteger)
1829		{
1830		if (u->MappedV4.ip.v4.NotAnInteger) ar->resrec.rdata->u.ipv4 = u->MappedV4.ip.v4;
1831		else                                ar->resrec.rdata->u.ipv4 = u->AdvertisedV4.ip.v4;
1832		}
1833	else if (type == mDNSAddrType_IPv6 && u->AdvertisedV6.ip.v6.b[0])
1834		{
1835		ar->resrec.rdata->u.ipv6 = u->AdvertisedV6.ip.v6;
1836		}
1837
1838	ar->uDNS_info.state = regState_Unregistered;
1839
1840	if (*dst)
1841		{
1842		LogMsg("ERROR: AssignHostnameInfoAuthRecord - overwriting %s AuthRec", type == mDNSAddrType_IPv4 ? "IPv4" : "IPv6");
1843		unlinkAR(&u->RecordRegistrations, *dst);
1844		(*dst)->RecordContext = mDNSNULL;  // defensively clear backpointer to avoid doubly-referenced context
1845		}
1846
1847	*dst = ar;
1848	}
1849
1850
1851// Deregister hostnames and register new names for each host domain with the current global
1852// values for the hostlabel and primary IP address
1853mDNSlocal void UpdateHostnameRegistrations(mDNS *m)
1854	{
1855	uDNS_GlobalInfo *u = &m->uDNS_info;
1856	uDNS_HostnameInfo *i;
1857
1858	for (i = u->Hostnames; i; i = i->next)
1859		{
1860		if (i->arv4 && i->arv4->uDNS_info.state != regState_Unregistered &&
1861			i->arv4->resrec.rdata->u.ipv4.NotAnInteger != u->AdvertisedV4.ip.v4.NotAnInteger &&
1862			i->arv4->resrec.rdata->u.ipv4.NotAnInteger !=u->MappedV4.ip.v4.NotAnInteger)
1863			{
1864			uDNS_DeregisterRecord(m, i->arv4);
1865			i->arv4 = mDNSNULL;
1866			}
1867		if (i->arv6 && !mDNSPlatformMemSame(i->arv6->resrec.rdata->u.ipv6.b, u->AdvertisedV6.ip.v6.b, 16) && i->arv6->uDNS_info.state != regState_Unregistered)
1868			{
1869			uDNS_DeregisterRecord(m, i->arv6);
1870			i->arv6 = mDNSNULL;
1871			}
1872
1873		if (!i->arv4 && u->AdvertisedV4.ip.v4.NotAnInteger)                    AssignHostnameInfoAuthRecord(m, i, mDNSAddrType_IPv4);
1874		else if (i->arv4 && i->arv4->uDNS_info.state == regState_Unregistered) i->arv4->resrec.rdata->u.ipv4 = u->AdvertisedV4.ip.v4;  // simply overwrite unregistered
1875		if (!i->arv6 && u->AdvertisedV6.ip.v6.b[0])                            AssignHostnameInfoAuthRecord(m, i, mDNSAddrType_IPv6);
1876		else if (i->arv6 &&i->arv6->uDNS_info.state == regState_Unregistered)  i->arv6->resrec.rdata->u.ipv6 = u->AdvertisedV6.ip.v6;
1877
1878		AdvertiseHostname(m, i);
1879		}
1880	}
1881
1882mDNSexport void mDNS_AddDynDNSHostName(mDNS *m, const domainname *fqdn, mDNSRecordCallback *StatusCallback, const void *StatusContext)
1883   {
1884	uDNS_GlobalInfo *u = &m->uDNS_info;
1885	uDNS_HostnameInfo *ptr, *new;
1886
1887	mDNS_Lock(m);
1888
1889	// check if domain already registered
1890	for (ptr = u->Hostnames; ptr; ptr = ptr->next)
1891		{
1892		if (SameDomainName(fqdn, &ptr->fqdn))
1893			{ LogMsg("Host Domain %##s already in list", fqdn->c); goto exit; }
1894		}
1895
1896	// allocate and format new address record
1897	new = umalloc(sizeof(*new));
1898	if (!new) { LogMsg("ERROR: mDNS_AddDynDNSHostname - malloc"); goto exit; }
1899	ubzero(new, sizeof(*new));
1900    new->next = u->Hostnames;
1901	u->Hostnames = new;
1902
1903	AssignDomainName(&new->fqdn, fqdn);
1904	new->StatusCallback = StatusCallback;
1905	new->StatusContext = StatusContext;
1906
1907	if (u->AdvertisedV4.ip.v4.NotAnInteger) AssignHostnameInfoAuthRecord(m, new, mDNSAddrType_IPv4);
1908	else new->arv4 = mDNSNULL;
1909	if (u->AdvertisedV6.ip.v6.b[0])         AssignHostnameInfoAuthRecord(m, new, mDNSAddrType_IPv6);
1910	else new->arv6 = mDNSNULL;
1911
1912	 if (u->AdvertisedV6.ip.v6.b[0] || u->AdvertisedV4.ip.v4.NotAnInteger) AdvertiseHostname(m, new);
1913
1914exit:
1915	mDNS_Unlock(m);
1916	}
1917
1918mDNSexport void mDNS_RemoveDynDNSHostName(mDNS *m, const domainname *fqdn)
1919	{
1920	uDNS_GlobalInfo *u = &m->uDNS_info;
1921	uDNS_HostnameInfo **ptr = &u->Hostnames;
1922
1923	mDNS_Lock(m);
1924
1925	while (*ptr && !SameDomainName(fqdn, &(*ptr)->fqdn)) ptr = &(*ptr)->next;
1926	if (!*ptr) LogMsg("mDNS_RemoveDynDNSHostName: no such domainname %##s", fqdn->c);
1927	else
1928		{
1929		uDNS_HostnameInfo *hi = *ptr;
1930		*ptr = (*ptr)->next; // unlink
1931		if (hi->arv4)
1932			{
1933			hi->arv4->RecordContext = mDNSNULL; // about to free wrapper struct
1934			if (hi->arv4->uDNS_info.state != regState_Unregistered) uDNS_DeregisterRecord(m, hi->arv4);
1935			else { ufree(hi->arv4); hi->arv4 = mDNSNULL; }
1936			}
1937		if (hi->arv6)
1938			{
1939			hi->arv6->RecordContext = mDNSNULL; // about to free wrapper struct
1940			if (hi->arv6->uDNS_info.state != regState_Unregistered) uDNS_DeregisterRecord(m, hi->arv6);
1941			else { ufree(hi->arv6); hi->arv6 = mDNSNULL; }
1942			}
1943		ufree(hi);
1944		}
1945	UpdateSRVRecords(m);
1946	mDNS_Unlock(m);
1947	}
1948
1949mDNSexport void mDNS_SetPrimaryInterfaceInfo(mDNS *m, const mDNSAddr *v4addr, const mDNSAddr *v6addr, const mDNSAddr *router)
1950	{
1951	uDNS_GlobalInfo *u = &m->uDNS_info;
1952	mDNSBool v4Changed, v6Changed, RouterChanged;
1953
1954	if (v4addr && v4addr->type != mDNSAddrType_IPv4) { LogMsg("mDNS_SetPrimaryInterfaceInfo V4 address - incorrect type.  Discarding."); return; }
1955	if (v6addr && v6addr->type != mDNSAddrType_IPv6) { LogMsg("mDNS_SetPrimaryInterfaceInfo V6 address - incorrect type.  Discarding."); return; }
1956	if (router && router->type != mDNSAddrType_IPv4) { LogMsg("mDNS_SetPrimaryInterfaceInfo passed non-V4 router.  Discarding."); return; }
1957
1958	mDNS_Lock(m);
1959
1960	v4Changed   = (v4addr ? v4addr->ip.v4.NotAnInteger : 0) != u->AdvertisedV4.ip.v4.NotAnInteger;
1961	v6Changed   = v6addr ? !mDNSPlatformMemSame(v6addr, &u->AdvertisedV6, sizeof(*v6addr)) : (u->AdvertisedV6.ip.v6.b[0] != 0);
1962	RouterChanged = (router ? router->ip.v4.NotAnInteger : 0) != u->Router.ip.v4.NotAnInteger;
1963
1964#if MDNS_DEBUGMSGS
1965	if (v4addr && (v4Changed || RouterChanged))
1966		LogMsg("mDNS_SetPrimaryInterfaceInfo: address changed from %d.%d.%d.%d to %d.%d.%d.%d:%d",
1967			   u->AdvertisedV4.ip.v4.b[0], u->AdvertisedV4.ip.v4.b[1], u->AdvertisedV4.ip.v4.b[2], u->AdvertisedV4.ip.v4.b[3],
1968			   v4addr->ip.v4.b[0], v4addr->ip.v4.b[1], v4addr->ip.v4.b[2], v4addr->ip.v4.b[3]);
1969#endif // MDNS_DEBUGMSGS
1970
1971	if ((v4Changed || RouterChanged) && u->MappedV4.ip.v4.NotAnInteger) u->MappedV4.ip.v4.NotAnInteger = 0;
1972	if (v4addr) u->AdvertisedV4 = *v4addr;  else u->AdvertisedV4.ip.v4.NotAnInteger = 0;
1973	if (v6addr) u->AdvertisedV6 = *v6addr;  else ubzero(u->AdvertisedV6.ip.v6.b, 16);
1974	if (router) u->Router       = *router;  else u->Router.ip.v4.NotAnInteger = 0;
1975	// setting router to zero indicates that nat mappings must be reestablished when router is reset
1976
1977	if ((v4Changed || RouterChanged || v6Changed) && v4addr)
1978		{
1979		// don't update these unless we've got V4
1980		UpdateHostnameRegistrations(m);
1981		UpdateSRVRecords(m);
1982		GetStaticHostname(m);  // look up reverse map record to find any static hostnames for our IP address
1983		}
1984
1985	mDNS_Unlock(m);
1986	}
1987
1988// ***************************************************************************
1989#if COMPILER_LIKES_PRAGMA_MARK
1990#pragma mark - Incoming Message Processing
1991#endif
1992
1993mDNSlocal mDNSBool kaListContainsAnswer(DNSQuestion *question, CacheRecord *rr)
1994	{
1995	CacheRecord *ptr;
1996
1997	for (ptr = question->uDNS_info.knownAnswers; ptr; ptr = ptr->next)
1998		if (SameResourceRecord(&ptr->resrec, &rr->resrec)) return mDNStrue;
1999
2000	return mDNSfalse;
2001	}
2002
2003
2004mDNSlocal void removeKnownAnswer(DNSQuestion *question, CacheRecord *rr)
2005	{
2006	CacheRecord *ptr, *prev = mDNSNULL;
2007
2008	for (ptr = question->uDNS_info.knownAnswers; ptr; ptr = ptr->next)
2009		{
2010		if (SameResourceRecord(&ptr->resrec, &rr->resrec))
2011			{
2012			if (prev) prev->next = ptr->next;
2013			else question->uDNS_info.knownAnswers = ptr->next;
2014			ufree(ptr);
2015			return;
2016			}
2017		prev = ptr;
2018		}
2019	LogMsg("removeKnownAnswer() called for record not in KA list");
2020	}
2021
2022
2023mDNSlocal void addKnownAnswer(DNSQuestion *question, const CacheRecord *rr)
2024	{
2025	CacheRecord *newCR = mDNSNULL;
2026	mDNSu32 size;
2027
2028	size = sizeof(CacheRecord) + rr->resrec.rdlength - InlineCacheRDSize;
2029	newCR = (CacheRecord *)umalloc(size);
2030	if (!newCR) { LogMsg("ERROR: addKnownAnswer - malloc"); return; }
2031	umemcpy(newCR, rr, size);
2032	newCR->resrec.rdata = (RData*)&newCR->rdatastorage;
2033	newCR->resrec.rdata->MaxRDLength = rr->resrec.rdlength;
2034	newCR->resrec.name = &question->qname;
2035	newCR->next = question->uDNS_info.knownAnswers;
2036	question->uDNS_info.knownAnswers = newCR;
2037	}
2038
2039mDNSlocal void deriveGoodbyes(mDNS * const m, DNSMessage *msg, const  mDNSu8 *end, DNSQuestion *question)
2040	{
2041	const mDNSu8 *ptr;
2042	int i;
2043	CacheRecord *fptr, *ka, *cr, *answers = mDNSNULL, *prev = mDNSNULL;
2044	LargeCacheRecord *lcr;
2045
2046	if (question != m->uDNS_info.CurrentQuery) { LogMsg("ERROR: deriveGoodbyes called without CurrentQuery set!"); return; }
2047
2048	ptr = LocateAnswers(msg, end);
2049	if (!ptr) goto pkt_error;
2050
2051	if (!msg->h.numAnswers)
2052		{
2053		// delete the whole KA list
2054		ka = question->uDNS_info.knownAnswers;
2055		while (ka)
2056			{
2057			debugf("deriving goodbye for %##s", ka->resrec.name->c);
2058
2059			m->mDNS_reentrancy++; // Increment to allow client to legally make mDNS API calls from the callback
2060			question->QuestionCallback(m, question, &ka->resrec, mDNSfalse);
2061			m->mDNS_reentrancy--; // Decrement to block mDNS API calls again
2062			// CAUTION: Need to be careful after calling question->QuestionCallback(),
2063			// because the client's callback function is allowed to do anything,
2064			// including starting/stopping queries, registering/deregistering records, etc.
2065			if (question != m->uDNS_info.CurrentQuery)
2066				{
2067				debugf("deriveGoodbyes - question removed via callback.  returning.");
2068				return;
2069				}
2070			fptr = ka;
2071			ka = ka->next;
2072			ufree(fptr);
2073			}
2074		question->uDNS_info.knownAnswers = mDNSNULL;
2075		return;
2076		}
2077
2078	// make a list of all the new answers
2079	for (i = 0; i < msg->h.numAnswers; i++)
2080		{
2081		lcr = (LargeCacheRecord *)umalloc(sizeof(LargeCacheRecord));
2082		if (!lcr) goto malloc_error;
2083		ubzero(lcr, sizeof(LargeCacheRecord));
2084		ptr = GetLargeResourceRecord(m, msg, ptr, end, 0, kDNSRecordTypePacketAns, lcr);
2085		if (!ptr) goto pkt_error;
2086		cr = &lcr->r;
2087		if (ResourceRecordAnswersQuestion(&cr->resrec, question))
2088			{
2089			cr->next = answers;
2090			answers = cr;
2091			}
2092		else ufree(cr);
2093		}
2094
2095	// make sure every known answer is in the answer list
2096	ka = question->uDNS_info.knownAnswers;
2097	while (ka)
2098		{
2099		for (cr = answers; cr; cr = cr->next)
2100			{ if (SameResourceRecord(&ka->resrec, &cr->resrec)) break; }
2101		if (!cr)
2102			{
2103			// record is in KA list but not answer list - remove from KA list
2104			if (prev) prev->next = ka->next;
2105			else question->uDNS_info.knownAnswers = ka->next;
2106			debugf("deriving goodbye for %##s", ka->resrec.name->c);
2107			m->mDNS_reentrancy++; // Increment to allow client to legally make mDNS API calls from the callback
2108			question->QuestionCallback(m, question, &ka->resrec, mDNSfalse);
2109			m->mDNS_reentrancy--; // Decrement to block mDNS API calls again
2110			// CAUTION: Need to be careful after calling question->QuestionCallback(),
2111			// because the client's callback function is allowed to do anything,
2112			// including starting/stopping queries, registering/deregistering records, etc.
2113			if (question != m->uDNS_info.CurrentQuery)
2114				{
2115				debugf("deriveGoodbyes - question removed via callback.  returning.");
2116				return;
2117				}
2118			fptr = ka;
2119			ka = ka->next;
2120			ufree(fptr);
2121			}
2122		else
2123			{
2124			prev = ka;
2125			ka = ka->next;
2126			}
2127		}
2128
2129	// free temp answers list
2130	cr = answers;
2131	while (cr) { fptr = cr; cr = cr->next; ufree(fptr); }
2132
2133	return;
2134
2135	pkt_error:
2136	LogMsg("ERROR: deriveGoodbyes - received malformed response to query for %##s (%d)",
2137		   question->qname.c, question->qtype);
2138	return;
2139
2140	malloc_error:
2141	LogMsg("ERROR: Malloc");
2142	}
2143
2144mDNSlocal void pktResponseHndlr(mDNS * const m, DNSMessage *msg, const  mDNSu8 *end, DNSQuestion *question, mDNSBool llq)
2145	{
2146	const mDNSu8 *ptr;
2147	int i;
2148	CacheRecord *cr = &m->rec.r;
2149	mDNSBool goodbye, inKAList;
2150	int	followedCNames = 0;
2151	static const int maxCNames = 5;
2152	LLQ_Info *llqInfo = question->uDNS_info.llq;
2153	domainname origname;
2154	origname.c[0] = 0;
2155
2156	if (question != m->uDNS_info.CurrentQuery)
2157		{ LogMsg("ERROR: pktResponseHdnlr called without CurrentQuery ptr set!");  return; }
2158
2159	if (question->uDNS_info.Answered == 0 && msg->h.numAnswers == 0 && !llq)
2160		{
2161		/* NXDOMAIN error or empty RR set - notify client */
2162		question->uDNS_info.Answered = mDNStrue;
2163
2164		/* Create empty resource record */
2165		cr->resrec.RecordType = kDNSRecordTypeUnregistered;
2166		cr->resrec.InterfaceID = mDNSNULL;
2167		cr->resrec.name = &question->qname;
2168		cr->resrec.rrtype = question->qtype;
2169		cr->resrec.rrclass = question->qclass;
2170		cr->resrec.rroriginalttl = 1; /* What should we use for the TTL? TTL from SOA for domain? */
2171		cr->resrec.rdlength = 0;
2172		cr->resrec.rdestimate = 0;
2173		cr->resrec.namehash = 0;
2174		cr->resrec.namehash = 0;
2175		cr->resrec.rdata = (RData*)&cr->rdatastorage;
2176		cr->resrec.rdata->MaxRDLength = cr->resrec.rdlength;
2177
2178		/* Pass empty answer to callback */
2179		m->mDNS_reentrancy++; // Increment to allow client to legally make mDNS API calls from the callback
2180		question->QuestionCallback(m, question, &cr->resrec, 0);
2181		m->mDNS_reentrancy--; // Decrement to block mDNS API calls again
2182		// CAUTION: Need to be careful after calling question->QuestionCallback(),
2183		// because the client's callback function is allowed to do anything,
2184		// including starting/stopping queries, registering/deregistering records, etc.
2185		m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it
2186		if (question != m->uDNS_info.CurrentQuery)
2187			{
2188			debugf("pktResponseHndlr - CurrentQuery changed by QuestionCallback - returning.");
2189			return;
2190			}
2191		}
2192
2193	question->uDNS_info.Answered = mDNStrue;
2194
2195	ptr = LocateAnswers(msg, end);
2196	if (!ptr) goto pkt_error;
2197
2198	for (i = 0; i < msg->h.numAnswers; i++)
2199		{
2200		ptr = GetLargeResourceRecord(m, msg, ptr, end, 0, kDNSRecordTypePacketAns, &m->rec);
2201		if (!ptr) goto pkt_error;
2202		if (ResourceRecordAnswersQuestion(&cr->resrec, question))
2203			{
2204			goodbye = llq ? ((mDNSs32)cr->resrec.rroriginalttl == -1) : mDNSfalse;
2205			if (cr->resrec.rrtype == kDNSType_CNAME)
2206				{
2207				if (followedCNames > (maxCNames - 1)) LogMsg("Error: too many CNAME referals for question %##s", &origname);
2208				else
2209					{
2210					debugf("Following cname %##s -> %##s", question->qname.c, cr->resrec.rdata->u.name.c);
2211					if (question->ReturnCNAME)
2212						{
2213						m->mDNS_reentrancy++; // Increment to allow client to legally make mDNS API calls from the callback
2214						question->QuestionCallback(m, question, &cr->resrec, !goodbye);
2215						m->mDNS_reentrancy--; // Decrement to block mDNS API calls again
2216						// CAUTION: Need to be careful after calling question->QuestionCallback(),
2217						// because the client's callback function is allowed to do anything,
2218						// including starting/stopping queries, registering/deregistering records, etc.
2219						if (question != m->uDNS_info.CurrentQuery)
2220							{
2221							m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it
2222							debugf("pktResponseHndlr - CurrentQuery changed by QuestionCallback - returning.");
2223							return;
2224							}
2225						}
2226					AssignDomainName(&origname, &question->qname);
2227					AssignDomainName(&question->qname, &cr->resrec.rdata->u.name);
2228					question->qnamehash = DomainNameHashValue(&question->qname);
2229					followedCNames++;
2230					i = -1; // restart packet answer matching
2231					ptr = LocateAnswers(msg, end);
2232					m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it
2233					continue;
2234					}
2235				}
2236
2237			inKAList = kaListContainsAnswer(question, cr);
2238
2239			if ((goodbye && !inKAList) || (!goodbye && inKAList))
2240				{
2241				m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it
2242				continue;  // list up to date
2243				}
2244			if (!inKAList) addKnownAnswer(question, cr);
2245			if (goodbye) removeKnownAnswer(question, cr);
2246			m->mDNS_reentrancy++; // Increment to allow client to legally make mDNS API calls from the callback
2247			question->QuestionCallback(m, question, &cr->resrec, !goodbye);
2248			m->mDNS_reentrancy--; // Decrement to block mDNS API calls again
2249			if (question != m->uDNS_info.CurrentQuery)
2250				{
2251				m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it
2252				debugf("pktResponseHndlr - CurrentQuery changed by QuestionCallback - returning");
2253				return;
2254				}
2255			}
2256
2257		m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it
2258		}
2259
2260	if (!llq || llqInfo->state == LLQ_Poll || llqInfo->deriveRemovesOnResume)
2261		{
2262		deriveGoodbyes(m, msg, end,question);
2263		if (llq && llqInfo->deriveRemovesOnResume) llqInfo->deriveRemovesOnResume = mDNSfalse;
2264		}
2265
2266	// Our interval may be set lower to recover from failures -- now that we have an answer, fully back off retry.
2267	// If the server advertised an LLQ-specific port number then that implies that this zone
2268	// *wants* to support LLQs, so if the setup fails (e.g. because we are behind a NAT)
2269	// then we use a slightly faster polling rate to give slightly better user experience.
2270	if (llq && llqInfo->state == LLQ_Poll && llqInfo->servPort.NotAnInteger) question->ThisQInterval = LLQ_POLL_INTERVAL;
2271	else if (question->ThisQInterval < MAX_UCAST_POLL_INTERVAL) question->ThisQInterval = MAX_UCAST_POLL_INTERVAL;
2272	return;
2273
2274	pkt_error:
2275	LogMsg("ERROR: pktResponseHndlr - received malformed response to query for %##s (%d)",
2276		   question->qname.c, question->qtype);
2277	return;
2278	}
2279
2280mDNSlocal void simpleResponseHndlr(mDNS * const m, DNSMessage *msg, const  mDNSu8 *end, DNSQuestion *question, void *context)
2281	{
2282	(void)context; // unused
2283	pktResponseHndlr(m, msg, end, question, mDNSfalse);
2284	}
2285
2286mDNSlocal void llqResponseHndlr(mDNS * const m, DNSMessage *msg, const  mDNSu8 *end, DNSQuestion *question, void *context)
2287	{
2288	(void)context; // unused
2289	pktResponseHndlr(m, msg, end, question, mDNStrue);
2290	}
2291
2292mDNSlocal mStatus ParseTSIGError(mDNS *m, const DNSMessage *msg, const mDNSu8 *end, const domainname *displayname)
2293	{
2294	LargeCacheRecord lcr;
2295	const mDNSu8 *ptr;
2296	mStatus err = mStatus_NoError;
2297	int i;
2298
2299	ptr = LocateAdditionals(msg, end);
2300	if (!ptr) goto finish;
2301
2302	for (i = 0; i < msg->h.numAdditionals; i++)
2303		{
2304		ptr = GetLargeResourceRecord(m, msg, ptr, end, 0, kDNSRecordTypePacketAdd, &lcr);
2305		if (!ptr) goto finish;
2306		if (lcr.r.resrec.rrtype == kDNSType_TSIG)
2307			{
2308			mDNSu32 macsize;
2309		    mDNSu8 *rd = lcr.r.resrec.rdata->u.data;
2310			mDNSu8 *rdend = rd + MaximumRDSize;
2311			int alglen = DomainNameLength(&lcr.r.resrec.rdata->u.name);
2312
2313			if (rd +  alglen > rdend) goto finish;
2314			rd += alglen;                                       // algorithm name
2315			if (rd + 6 > rdend) goto finish;
2316			rd += 6;                                            // 48-bit timestamp
2317			if (rd + sizeof(mDNSOpaque16) > rdend) goto finish;
2318			rd += sizeof(mDNSOpaque16);                         // fudge
2319			if (rd + sizeof(mDNSOpaque16) > rdend) goto finish;
2320			macsize = mDNSVal16(*(mDNSOpaque16 *)rd);
2321			rd += sizeof(mDNSOpaque16);                         // MAC size
2322			if (rd + macsize > rdend) goto finish;
2323			rd += macsize;
2324			if (rd + sizeof(mDNSOpaque16) > rdend) goto finish;
2325			rd += sizeof(mDNSOpaque16);                         // orig id
2326			if (rd + sizeof(mDNSOpaque16) > rdend) goto finish;
2327			err = mDNSVal16(*(mDNSOpaque16 *)rd);               // error code
2328
2329			if (err ==  TSIG_ErrBadSig)      { LogMsg("%##s: bad signature", displayname->c);              err = mStatus_BadSig;     }
2330			else if (err == TSIG_ErrBadKey)  { LogMsg("%##s: bad key", displayname->c);                    err = mStatus_BadKey;     }
2331			else if (err == TSIG_ErrBadTime) { LogMsg("%##s: bad time", displayname->c);                   err = mStatus_BadTime;    }
2332			else if (err)                    { LogMsg("%##s: unknown tsig error %d", displayname->c, err); err = mStatus_UnknownErr; }
2333			goto finish;
2334			}
2335		}
2336
2337	finish:
2338	return err;
2339	}
2340
2341mDNSlocal mStatus checkUpdateResult(domainname *displayname, mDNSu8 rcode, mDNS *m, const DNSMessage *msg, const mDNSu8 *end)
2342	{
2343	(void)msg;  // currently unused, needed for TSIG errors
2344	if (!rcode) return mStatus_NoError;
2345	else if (rcode == kDNSFlag1_RC_YXDomain)
2346		{
2347		debugf("name in use: %##s", displayname->c);
2348		return mStatus_NameConflict;
2349		}
2350	else if (rcode == kDNSFlag1_RC_Refused)
2351		{
2352		LogMsg("Update %##s refused", displayname->c);
2353		return mStatus_Refused;
2354		}
2355	else if (rcode == kDNSFlag1_RC_NXRRSet)
2356		{
2357		LogMsg("Reregister refused (NXRRSET): %##s", displayname->c);
2358		return mStatus_NoSuchRecord;
2359		}
2360	else if (rcode == kDNSFlag1_RC_NotAuth)
2361		{
2362		// TSIG errors should come with FmtErr as per RFC 2845, but BIND 9 sends them with NotAuth so we look here too
2363		mStatus tsigerr = ParseTSIGError(m, msg, end, displayname);
2364		if (!tsigerr)
2365			{
2366			LogMsg("Permission denied (NOAUTH): %##s", displayname->c);
2367			return mStatus_UnknownErr;
2368			}
2369		else return tsigerr;
2370		}
2371	else if (rcode == kDNSFlag1_RC_FmtErr)
2372		{
2373		mStatus tsigerr = ParseTSIGError(m, msg, end, displayname);
2374		if (!tsigerr)
2375			{
2376			LogMsg("Format Error: %##s", displayname->c);
2377			return mStatus_UnknownErr;
2378			}
2379		else return tsigerr;
2380		}
2381	else
2382		{
2383		LogMsg("Update %##s failed with rcode %d", displayname->c, rcode);
2384		return mStatus_UnknownErr;
2385		}
2386	}
2387
2388mDNSlocal void hndlServiceUpdateReply(mDNS * const m, ServiceRecordSet *srs,  mStatus err)
2389	{
2390	mDNSBool InvokeCallback = mDNSfalse;
2391	uDNS_RegInfo *info = &srs->uDNS_info;
2392	NATTraversalInfo *nat = srs->uDNS_info.NATinfo;
2393	ExtraResourceRecord **e = &srs->Extras;
2394	AuthRecord *txt = &srs->RR_TXT;
2395	uDNS_RegInfo *txtInfo = &txt->uDNS_info;
2396	switch (info->state)
2397		{
2398		case regState_Pending:
2399			if (err == mStatus_NameConflict && !info->TestForSelfConflict)
2400				{
2401				info->TestForSelfConflict = mDNStrue;
2402				debugf("checking for self-conflict of service %##s", srs->RR_SRV.resrec.name->c);
2403				SendServiceRegistration(m, srs);
2404				return;
2405				}
2406			else if (info->TestForSelfConflict)
2407				{
2408				info->TestForSelfConflict = mDNSfalse;
2409				if (err == mStatus_NoSuchRecord) err = mStatus_NameConflict;  // NoSuchRecord implies that our prereq was not met, so we actually have a name conflict
2410				if (err) info->state = regState_Unregistered;
2411				else info->state = regState_Registered;
2412				InvokeCallback = mDNStrue;
2413				break;
2414				}
2415			else if (err == mStatus_UnknownErr && info->lease)
2416				{
2417				LogMsg("Re-trying update of service %##s without lease option", srs->RR_SRV.resrec.name->c);
2418				info->lease = mDNSfalse;
2419				SendServiceRegistration(m, srs);
2420				return;
2421				}
2422			else
2423				{
2424				if (err) { LogMsg("Error %ld for registration of service %##s", err, srs->RR_SRV.resrec.name->c); info->state = regState_Unregistered; } //!!!KRS make sure all structs will still get cleaned up when client calls DeregisterService with this state
2425				else info->state = regState_Registered;
2426				InvokeCallback = mDNStrue;
2427				break;
2428				}
2429		case regState_Refresh:
2430			if (err)
2431				{
2432				LogMsg("Error %ld for refresh of service %##s", err, srs->RR_SRV.resrec.name->c);
2433				InvokeCallback = mDNStrue;
2434				info->state = regState_Unregistered;
2435				}
2436			else info->state = regState_Registered;
2437			break;
2438		case regState_DeregPending:
2439			if (err) LogMsg("Error %ld for deregistration of service %##s", err, srs->RR_SRV.resrec.name->c);
2440			if (info->SRVChanged)
2441				{
2442				info->state = regState_NoTarget;  // NoTarget will allow us to pick up new target OR nat traversal state
2443				break;
2444				}
2445			err = mStatus_MemFree;
2446			InvokeCallback = mDNStrue;
2447			if (nat)
2448				{
2449				if (nat->state == NATState_Deleted) { info->NATinfo = mDNSNULL; FreeNATInfo(m, nat); } // deletion copmleted
2450				else nat->reg.ServiceRegistration = mDNSNULL;  // allow mapping deletion to continue
2451				}
2452			info->state = regState_Unregistered;
2453			break;
2454		case regState_DeregDeferred:
2455			if (err)
2456				{
2457				debugf("Error %ld received prior to deferred derigstration of %##s", err, srs->RR_SRV.resrec.name->c);
2458				err = mStatus_MemFree;
2459				InvokeCallback = mDNStrue;
2460				info->state = regState_Unregistered;
2461				break;
2462				}
2463			else
2464				{
2465				debugf("Performing deferred deregistration of %##s", srs->RR_SRV.resrec.name->c);
2466				info->state = regState_Registered;
2467				SendServiceDeregistration(m, srs);
2468				return;
2469				}
2470		case regState_UpdatePending:
2471			if (err)
2472				{
2473				LogMsg("hndlServiceUpdateReply: error updating TXT record for service %##s", srs->RR_SRV.resrec.name->c);
2474				info->state = regState_Unregistered;
2475				InvokeCallback = mDNStrue;
2476				}
2477			else
2478				{
2479				info->state = regState_Registered;
2480				// deallocate old RData
2481				if (txtInfo->UpdateRDCallback) txtInfo->UpdateRDCallback(m, txt, txtInfo->OrigRData);
2482				SetNewRData(&txt->resrec, txtInfo->InFlightRData, txtInfo->InFlightRDLen);
2483				txtInfo->OrigRData = mDNSNULL;
2484				txtInfo->InFlightRData = mDNSNULL;
2485				}
2486			break;
2487		case regState_FetchingZoneData:
2488		case regState_Registered:
2489		case regState_Cancelled:
2490		case regState_Unregistered:
2491		case regState_NATMap:
2492		case regState_NoTarget:
2493		case regState_ExtraQueued:
2494		case regState_NATError:
2495			LogMsg("hndlServiceUpdateReply called for service %##s in unexpected state %d with error %ld.  Unlinking.",
2496				   srs->RR_SRV.resrec.name->c, info->state, err);
2497			err = mStatus_UnknownErr;
2498		}
2499
2500	if ((info->SRVChanged || info->SRVUpdateDeferred) && (info->state == regState_NoTarget || info->state == regState_Registered))
2501		{
2502		if (InvokeCallback)
2503			{
2504			info->ClientCallbackDeferred = mDNStrue;
2505			info->DeferredStatus = err;
2506			}
2507		info->SRVChanged = mDNSfalse;
2508		UpdateSRV(m, srs);
2509		return;
2510		}
2511
2512	while (*e)
2513		{
2514		uDNS_RegInfo *einfo = &(*e)->r.uDNS_info;
2515		if (einfo->state == regState_ExtraQueued)
2516			{
2517			if (info->state == regState_Registered && !err)
2518				{
2519				// extra resource record queued for this service - copy zone info and register
2520				AssignDomainName(&einfo->zone, &info->zone);
2521				einfo->ns = info->ns;
2522				einfo->port = info->port;
2523				einfo->lease = info->lease;
2524				sendRecordRegistration(m, &(*e)->r);
2525				e = &(*e)->next;
2526				}
2527			else if (err && einfo->state != regState_Unregistered)
2528				{
2529				// unlink extra from list
2530				einfo->state = regState_Unregistered;
2531				*e = (*e)->next;
2532				}
2533			else e = &(*e)->next;
2534			}
2535		else e = &(*e)->next;
2536		}
2537
2538	srs->RR_SRV.ThisAPInterval = INIT_UCAST_POLL_INTERVAL - 1;  // reset retry delay for future refreshes, dereg, etc.
2539	if (info->state == regState_Unregistered) unlinkSRS(m, srs);
2540	else if (txtInfo->QueuedRData && info->state == regState_Registered)
2541		{
2542		if (InvokeCallback)
2543			{
2544			// if we were supposed to give a client callback, we'll do it after we update the primary txt record
2545			info->ClientCallbackDeferred = mDNStrue;
2546			info->DeferredStatus = err;
2547			}
2548		info->state = regState_UpdatePending;
2549		txtInfo->InFlightRData = txtInfo->QueuedRData;
2550		txtInfo->InFlightRDLen = txtInfo->QueuedRDLen;
2551		info->OrigRData = txt->resrec.rdata;
2552		info->OrigRDLen = txt->resrec.rdlength;
2553		txtInfo->QueuedRData = mDNSNULL;
2554		SendServiceRegistration(m, srs);
2555		return;
2556		}
2557
2558	m->mDNS_reentrancy++; // Increment to allow client to legally make mDNS API calls from the callback
2559	if (InvokeCallback) srs->ServiceCallback(m, srs, err);
2560	else if (info->ClientCallbackDeferred)
2561		{
2562		info->ClientCallbackDeferred = mDNSfalse;
2563		srs->ServiceCallback(m, srs, info->DeferredStatus);
2564		}
2565	m->mDNS_reentrancy--; // Decrement to block mDNS API calls again
2566	// NOTE: do not touch structures after calling ServiceCallback
2567	}
2568
2569mDNSlocal void hndlRecordUpdateReply(mDNS *m, AuthRecord *rr, mStatus err)
2570	{
2571	uDNS_RegInfo *info = &rr->uDNS_info;
2572	mDNSBool InvokeCallback = mDNStrue;
2573
2574	if (info->state == regState_UpdatePending)
2575		{
2576		if (err)
2577			{
2578			LogMsg("Update record failed for %##s (err %d)", rr->resrec.name->c, err);
2579			info->state = regState_Unregistered;
2580			}
2581		else
2582			{
2583			debugf("Update record %##s - success", rr->resrec.name->c);
2584			info->state = regState_Registered;
2585			// deallocate old RData
2586			if (info->UpdateRDCallback) info->UpdateRDCallback(m, rr, info->OrigRData);
2587			SetNewRData(&rr->resrec, info->InFlightRData, info->InFlightRDLen);
2588			info->OrigRData = mDNSNULL;
2589			info->InFlightRData = mDNSNULL;
2590			}
2591		}
2592
2593	if (info->state == regState_DeregPending)
2594		{
2595		debugf("Received reply for deregister record %##s type %d", rr->resrec.name->c, rr->resrec.rrtype);
2596		if (err) LogMsg("ERROR: Deregistration of record %##s type %d failed with error %ld",
2597						rr->resrec.name->c, rr->resrec.rrtype, err);
2598		err = mStatus_MemFree;
2599		info->state = regState_Unregistered;
2600		}
2601
2602	if (info->state == regState_DeregDeferred)
2603		{
2604		if (err)
2605			{
2606			LogMsg("Cancelling deferred deregistration record %##s type %d due to registration error %ld",
2607				   rr->resrec.name->c, rr->resrec.rrtype, err);
2608			info->state = regState_Unregistered;
2609			}
2610		debugf("Calling deferred deregistration of record %##s type %d",  rr->resrec.name->c, rr->resrec.rrtype);
2611		info->state = regState_Registered;
2612		uDNS_DeregisterRecord(m, rr);
2613		return;
2614		}
2615
2616	if (info->state == regState_Pending || info->state == regState_Refresh)
2617		{
2618		if (!err)
2619			{
2620			info->state = regState_Registered;
2621			if (info->state == regState_Refresh) InvokeCallback = mDNSfalse;
2622			}
2623		else
2624			{
2625			if (info->lease && err == mStatus_UnknownErr)
2626				{
2627				LogMsg("Re-trying update of record %##s without lease option", rr->resrec.name->c);
2628				info->lease = mDNSfalse;
2629				sendRecordRegistration(m, rr);
2630				return;
2631				}
2632			LogMsg("Registration of record %##s type %d failed with error %ld", rr->resrec.name->c, rr->resrec.rrtype, err);
2633			info->state = regState_Unregistered;
2634			}
2635		}
2636
2637	if (info->state == regState_Unregistered) unlinkAR(&m->uDNS_info.RecordRegistrations, rr);
2638	else rr->ThisAPInterval = INIT_UCAST_POLL_INTERVAL - 1;  // reset retry delay for future refreshes, dereg, etc.
2639
2640	if (info->QueuedRData && info->state == regState_Registered)
2641		{
2642		info->state = regState_UpdatePending;
2643		info->InFlightRData = info->QueuedRData;
2644		info->InFlightRDLen = info->QueuedRDLen;
2645		info->OrigRData = rr->resrec.rdata;
2646		info->OrigRDLen = rr->resrec.rdlength;
2647		info->QueuedRData = mDNSNULL;
2648		sendRecordRegistration(m, rr);
2649		return;
2650		}
2651
2652	if (InvokeCallback)
2653		{
2654		m->mDNS_reentrancy++; // Increment to allow client to legally make mDNS API calls from the callback
2655		if (rr->RecordCallback) rr->RecordCallback(m, rr, err);
2656		m->mDNS_reentrancy--; // Decrement to block mDNS API calls again
2657		}
2658	}
2659
2660
2661mDNSlocal void SetUpdateExpiration(mDNS *m, DNSMessage *msg, const mDNSu8 *end, uDNS_RegInfo *info)
2662	{
2663	LargeCacheRecord lcr;
2664	const mDNSu8 *ptr;
2665	int i;
2666	mDNSu32 lease = 0;
2667	mDNSs32 expire;
2668
2669	ptr = LocateAdditionals(msg, end);
2670
2671	if (info->lease && (ptr = LocateAdditionals(msg, end)))
2672		{
2673		for (i = 0; i < msg->h.numAdditionals; i++)
2674			{
2675			ptr = GetLargeResourceRecord(m, msg, ptr, end, 0, kDNSRecordTypePacketAdd, &lcr);
2676			if (!ptr) break;
2677			if (lcr.r.resrec.rrtype == kDNSType_OPT)
2678				{
2679				if (lcr.r.resrec.rdlength < LEASE_OPT_RDLEN) continue;
2680				if (lcr.r.resrec.rdata->u.opt.opt != kDNSOpt_Lease) continue;
2681				lease = lcr.r.resrec.rdata->u.opt.OptData.lease;
2682				break;
2683				}
2684			}
2685		}
2686
2687	if (lease > 0)
2688		{
2689		expire = (mDNSPlatformTimeNow(m) + (((mDNSs32)lease * mDNSPlatformOneSecond)) * 3/4);
2690		if (info->state == regState_UpdatePending)
2691            // if updating individual record, the service record set may expire sooner
2692			{ if (expire - info->expire < 0) info->expire = expire; }
2693		else info->expire = expire;
2694		}
2695	else info->lease = mDNSfalse;
2696	}
2697
2698mDNSexport void uDNS_ReceiveNATMap(mDNS *m, mDNSu8 *pkt, mDNSu16 len)
2699	{
2700	uDNS_GlobalInfo *u = &m->uDNS_info;
2701	NATTraversalInfo *ptr = u->NATTraversals;
2702	NATOp_t op;
2703
2704	// check length, version, opcode
2705	if (len < sizeof(NATPortMapReply) && len < sizeof(NATAddrReply)) { LogMsg("NAT Traversal message too short (%d bytes)", len); return; }
2706	if (pkt[0] != NATMAP_VERS) { LogMsg("Received NAT Traversal response with version %d (expect version %d)", pkt[0], NATMAP_VERS); return; }
2707	op = pkt[1];
2708	if (!(op & NATMAP_RESPONSE_MASK)) { LogMsg("Received NAT Traversal message that is not a response (opcode %d)", op); return; }
2709
2710	while (ptr)
2711		{
2712		if ((ptr->state == NATState_Request || ptr->state == NATState_Refresh) && (ptr->op | NATMAP_RESPONSE_MASK) == op)
2713			if (ptr->ReceiveResponse(ptr, m, pkt, len)) break;  // note callback may invalidate ptr if it return value is non-zero
2714		ptr = ptr->next;
2715		}
2716	}
2717
2718mDNSlocal const domainname *DNSRelayTestQuestion = (domainname*)
2719	"\x1" "1" "\x1" "0" "\x1" "0" "\x3" "127" "\xa" "dnsbugtest"
2720	"\x1" "1" "\x1" "0" "\x1" "0" "\x3" "127" "\x7" "in-addr" "\x4" "arpa";
2721
2722// Returns mDNStrue if response was handled
2723mDNSlocal mDNSBool uDNS_ReceiveTestQuestionResponse(mDNS *const m, DNSMessage *const msg, const mDNSu8 *const end,
2724	const mDNSAddr *const srcaddr, const mDNSInterfaceID InterfaceID)
2725	{
2726	const mDNSu8 *ptr = msg->data;
2727	DNSQuestion q;
2728	DNSServer *s;
2729	mDNSu32 result = 0;
2730	mDNSBool found = mDNSfalse;
2731
2732	// 1. Find out if this is an answer to one of our test questions
2733	if (msg->h.numQuestions != 1) return(mDNSfalse);
2734	ptr = getQuestion(msg, ptr, end, InterfaceID, &q);
2735	if (!ptr) return(mDNSfalse);
2736	if (q.qtype != kDNSType_PTR || q.qclass != kDNSClass_IN) return(mDNSfalse);
2737	if (!SameDomainName(&q.qname, DNSRelayTestQuestion)) return(mDNSfalse);
2738
2739	// 2. If the DNS relay gave us a positive response, then it's got buggy firmware
2740	// else, if the DNS relay gave us an error or no-answer response, it passed our test
2741	if ((msg->h.flags.b[1] & kDNSFlag1_RC) == kDNSFlag1_RC_NoErr && msg->h.numAnswers > 0)
2742		result = DNSServer_Failed;
2743	else
2744		result = DNSServer_Passed;
2745
2746	// 3. Find occurrences of this server in our list, and mark them appropriately
2747	for (s = m->uDNS_info.Servers; s; s = s->next)
2748		if (mDNSSameAddress(srcaddr, &s->addr) && s->teststate != result)
2749			{ s->teststate = result; found = mDNStrue; }
2750
2751	// 4. Assuming we found the server in question in our list (don't want to risk being victim of a deliberate DOS attack here)
2752	// log a message to let the user know why Wide-Area Service Discovery isn't working
2753	if (found && result == DNSServer_Failed)
2754		LogMsg("NOTE: Wide-Area Service Discovery disabled to avoid crashing defective DNS relay %#a.", srcaddr);
2755
2756	return(mDNStrue); // Return mDNStrue to tell uDNS_ReceiveMsg it doens't need to process this packet further
2757	}
2758
2759mDNSexport void uDNS_ReceiveMsg(mDNS *const m, DNSMessage *const msg, const mDNSu8 *const end,
2760	const mDNSAddr *const srcaddr, const mDNSIPPort srcport, const mDNSAddr *const dstaddr,
2761	const mDNSIPPort dstport, const mDNSInterfaceID InterfaceID)
2762	{
2763	DNSQuestion *qptr;
2764	AuthRecord *rptr;
2765	ServiceRecordSet *sptr;
2766	mStatus err = mStatus_NoError;
2767	uDNS_GlobalInfo *u = &m->uDNS_info;
2768
2769	mDNSu8 StdR    = kDNSFlag0_QR_Response | kDNSFlag0_OP_StdQuery;
2770	mDNSu8 UpdateR = kDNSFlag0_QR_Response | kDNSFlag0_OP_Update;
2771	mDNSu8 QR_OP   = (mDNSu8)(msg->h.flags.b[0] & kDNSFlag0_QROP_Mask);
2772	mDNSu8 rcode   = (mDNSu8)(msg->h.flags.b[1] & kDNSFlag1_RC);
2773
2774	mDNSs32 timenow = mDNSPlatformTimeNow(m);
2775
2776    // unused
2777	(void)dstaddr;
2778	(void)dstport;
2779	(void)InterfaceID;
2780
2781	if (QR_OP == StdR)
2782		{
2783		// !!!KRS we should to a table lookup here to see if it answers an LLQ or a 1-shot
2784		// LLQ Responses over TCP not currently supported
2785		if (srcaddr && recvLLQResponse(m, msg, end, srcaddr, srcport, InterfaceID)) return;
2786
2787		if (uDNS_ReceiveTestQuestionResponse(m, msg, end, srcaddr, InterfaceID)) return;
2788
2789		for (qptr = u->ActiveQueries; qptr; qptr = qptr->next)
2790			{
2791			//!!!KRS we should have a hashtable, hashed on message id
2792			if (qptr->uDNS_info.id.NotAnInteger == msg->h.id.NotAnInteger)
2793				{
2794				if (timenow - (qptr->LastQTime + RESPONSE_WINDOW) > 0)
2795					{ debugf("uDNS_ReceiveMsg - response received after maximum allowed window.  Discarding"); return; }
2796				if (msg->h.flags.b[0] & kDNSFlag0_TC)
2797					{ hndlTruncatedAnswer(qptr, srcaddr, m); return; }
2798				else
2799					{
2800					u->CurrentQuery = qptr;
2801					qptr->uDNS_info.responseCallback(m, msg, end, qptr, qptr->uDNS_info.context);
2802					u->CurrentQuery = mDNSNULL;
2803					// Note: responseCallback can invalidate qptr
2804					return;
2805					}
2806				}
2807			}
2808		}
2809	if (QR_OP == UpdateR)
2810		{
2811		for (sptr = u->ServiceRegistrations; sptr; sptr = sptr->next)
2812			{
2813			if (sptr->uDNS_info.id.NotAnInteger == msg->h.id.NotAnInteger)
2814				{
2815				err = checkUpdateResult(sptr->RR_SRV.resrec.name, rcode, m, msg, end);
2816				if (!err) SetUpdateExpiration(m, msg, end, &sptr->uDNS_info);
2817				hndlServiceUpdateReply(m, sptr, err);
2818				return;
2819				}
2820			}
2821		for (rptr = u->RecordRegistrations; rptr; rptr = rptr->next)
2822			{
2823			if (rptr->uDNS_info.id.NotAnInteger == msg->h.id.NotAnInteger)
2824				{
2825				err = checkUpdateResult(rptr->resrec.name, rcode, m, msg, end);
2826				if (!err) SetUpdateExpiration(m, msg, end, &rptr->uDNS_info);
2827				hndlRecordUpdateReply(m, rptr, err);
2828				return;
2829				}
2830			}
2831		}
2832	debugf("Received unexpected response: ID %d matches no active records", mDNSVal16(msg->h.id));
2833	}
2834
2835// lookup a DNS Server, matching by name in split-dns configurations.  Result stored in addr parameter if successful
2836mDNSlocal DNSServer *GetServerForName(uDNS_GlobalInfo *u, const domainname *name)
2837    {
2838	DNSServer *curmatch = mDNSNULL, *p = u->Servers;
2839	int i, curmatchlen = -1;
2840	int ncount = name ? CountLabels(name) : 0;
2841
2842	while (p)
2843		{
2844		int scount = CountLabels(&p->domain);
2845		if (scount <= ncount && scount > curmatchlen)
2846			{
2847			// only inspect if server's domain is longer than current best match and shorter than the name itself
2848			const domainname *tail = name;
2849			for (i = 0; i < ncount - scount; i++)
2850				tail = (domainname *)(tail->c + 1 + tail->c[0]);  // find "tail" (scount labels) of name
2851			if (SameDomainName(tail, &p->domain)) { curmatch = p; curmatchlen = scount; }
2852			}
2853		p = p->next;
2854		}
2855	return(curmatch);
2856	}
2857
2858// ***************************************************************************
2859#if COMPILER_LIKES_PRAGMA_MARK
2860#pragma mark - Query Routines
2861#endif
2862
2863#define sameID(x,y) mDNSPlatformMemSame(x,y,8)
2864
2865mDNSlocal void initializeQuery(DNSMessage *msg, DNSQuestion *question)
2866	{
2867	ubzero(msg, sizeof(msg));
2868    InitializeDNSMessage(&msg->h, question->uDNS_info.id, uQueryFlags);
2869	}
2870
2871mDNSlocal mStatus constructQueryMsg(DNSMessage *msg, mDNSu8 **endPtr, DNSQuestion *const question)
2872	{
2873	initializeQuery(msg, question);
2874
2875	*endPtr = putQuestion(msg, msg->data, msg->data + AbsoluteMaxDNSMessageData, &question->qname, question->qtype, question->qclass);
2876    if (!*endPtr)
2877        {
2878        LogMsg("ERROR: Unicast query out of space in packet");
2879        return mStatus_UnknownErr;
2880        }
2881	return mStatus_NoError;
2882	}
2883
2884mDNSlocal mDNSu8 *putLLQ(DNSMessage *const msg, mDNSu8 *ptr, DNSQuestion *question, LLQOptData *data, mDNSBool includeQuestion)
2885	{
2886	AuthRecord rr;
2887	ResourceRecord *opt = &rr.resrec;
2888	rdataOpt *optRD;
2889
2890	//!!!KRS when we implement multiple llqs per message, we'll need to memmove anything past the question section
2891	if (includeQuestion)
2892		{
2893		ptr = putQuestion(msg, ptr, msg->data + AbsoluteMaxDNSMessageData, &question->qname, question->qtype, question->qclass);
2894		if (!ptr) { LogMsg("ERROR: putLLQ - putQuestion"); return mDNSNULL; }
2895		}
2896	// locate OptRR if it exists, set pointer to end
2897	// !!!KRS implement me
2898
2899
2900	// format opt rr (fields not specified are zero-valued)
2901	ubzero(&rr, sizeof(AuthRecord));
2902	mDNS_SetupResourceRecord(&rr, mDNSNULL, mDNSInterface_Any, kDNSType_OPT, kStandardTTL, kDNSRecordTypeKnownUnique, mDNSNULL, mDNSNULL);
2903	opt->rdlength = LLQ_OPT_RDLEN;
2904	opt->rdestimate = LLQ_OPT_RDLEN;
2905
2906	optRD = &rr.resrec.rdata->u.opt;
2907	optRD->opt = kDNSOpt_LLQ;
2908	optRD->optlen = LLQ_OPTLEN;
2909	umemcpy(&optRD->OptData.llq, data, sizeof(*data));
2910	ptr = PutResourceRecordTTLJumbo(msg, ptr, &msg->h.numAdditionals, opt, 0);
2911	if (!ptr) { LogMsg("ERROR: putLLQ - PutResourceRecordTTLJumbo"); return mDNSNULL; }
2912
2913	return ptr;
2914	}
2915
2916
2917mDNSlocal mDNSBool getLLQAtIndex(mDNS *m, DNSMessage *msg, const mDNSu8 *end, LLQOptData *llq, int index)
2918	{
2919	LargeCacheRecord lcr;
2920	int i;
2921	const mDNSu8 *ptr;
2922
2923	ubzero(&lcr, sizeof(lcr));
2924
2925	ptr = LocateAdditionals(msg, end);
2926	if (!ptr) return mDNSfalse;
2927
2928	// find the last additional
2929	for (i = 0; i < msg->h.numAdditionals; i++)
2930//		{ ptr = GetLargeResourceRecord(m, msg, ptr, end, 0, kDNSRecordTypePacketAdd, &lcr); if (!ptr) return mDNSfalse; }
2931//!!!KRS workaround for LH server bug, which puts OPT as first additional
2932		{ ptr = GetLargeResourceRecord(m, msg, ptr, end, 0, kDNSRecordTypePacketAdd, &lcr); if (!ptr) return mDNSfalse; if (lcr.r.resrec.rrtype == kDNSType_OPT) break; }
2933	if (lcr.r.resrec.rrtype != kDNSType_OPT) return mDNSfalse;
2934	if (lcr.r.resrec.rdlength < (index + 1) * LLQ_OPT_RDLEN) return mDNSfalse;  // rdata too small
2935	umemcpy(llq, (mDNSu8 *)&lcr.r.resrec.rdata->u.opt.OptData.llq + (index * sizeof(*llq)), sizeof(*llq));
2936	return mDNStrue;
2937	}
2938
2939mDNSlocal void recvRefreshReply(mDNS *m, DNSMessage *msg, const mDNSu8 *end, DNSQuestion *q)
2940	{
2941	LLQ_Info *qInfo;
2942	LLQOptData pktData;
2943
2944	qInfo = q->uDNS_info.llq;
2945	if (!getLLQAtIndex(m, msg, end, &pktData, 0)) { LogMsg("ERROR recvRefreshReply - getLLQAtIndex"); return; }
2946	if (pktData.llqOp != kLLQOp_Refresh) return;
2947	if (!sameID(pktData.id, qInfo->id)) { LogMsg("recvRefreshReply - ID mismatch.  Discarding");  return; }
2948	if (pktData.err != LLQErr_NoError) { LogMsg("recvRefreshReply: received error %d from server", pktData.err); return; }
2949
2950	qInfo->expire = mDNSPlatformTimeNow(m) + ((mDNSs32)pktData.lease * mDNSPlatformOneSecond);
2951	qInfo->retry = qInfo->expire - ((mDNSs32)pktData.lease * mDNSPlatformOneSecond/2);
2952
2953	qInfo->origLease = pktData.lease;
2954	qInfo->state = LLQ_Established;
2955	}
2956
2957mDNSlocal void sendLLQRefresh(mDNS *m, DNSQuestion *q, mDNSu32 lease)
2958	{
2959	DNSMessage msg;
2960	mDNSu8 *end;
2961	LLQOptData llq;
2962	LLQ_Info *info = q->uDNS_info.llq;
2963	mStatus err;
2964	mDNSs32 timenow;
2965
2966	timenow = mDNSPlatformTimeNow(m);
2967	if ((info->state == LLQ_Refresh && info->ntries >= kLLQ_MAX_TRIES) ||
2968		info->expire - timenow < 0)
2969		{
2970		LogMsg("Unable to refresh LLQ %##s - will retry in %d minutes", q->qname.c, kLLQ_DEF_RETRY/60);
2971		info->state = LLQ_Retry;
2972		info->retry = mDNSPlatformTimeNow(m) + kLLQ_DEF_RETRY * mDNSPlatformOneSecond;
2973		info->deriveRemovesOnResume = mDNStrue;
2974		return;
2975		//!!!KRS handle this - periodically try to re-establish
2976		}
2977
2978	llq.vers = kLLQ_Vers;
2979	llq.llqOp = kLLQOp_Refresh;
2980	llq.err = LLQErr_NoError;
2981	umemcpy(llq.id, info->id, 8);
2982	llq.lease = lease;
2983
2984	initializeQuery(&msg, q);
2985	end = putLLQ(&msg, msg.data, q, &llq, mDNStrue);
2986	if (!end) { LogMsg("ERROR: sendLLQRefresh - putLLQ"); return; }
2987
2988	err = mDNSSendDNSMessage(m, &msg, end, mDNSInterface_Any, &info->servAddr, info->servPort, -1, mDNSNULL);
2989	if (err) debugf("ERROR: sendLLQRefresh - mDNSSendDNSMessage returned %ld", err);
2990
2991	if (info->state == LLQ_Established) info->ntries = 1;
2992	else info->ntries++;
2993	info->state = LLQ_Refresh;
2994	q->LastQTime = timenow;
2995	info->retry = (info->expire - q->LastQTime) / 2;
2996	}
2997
2998mDNSlocal mDNSBool recvLLQEvent(mDNS *m, DNSQuestion *q, DNSMessage *msg, const mDNSu8 *end, const mDNSAddr *srcaddr, mDNSIPPort srcport, mDNSInterfaceID InterfaceID)
2999	{
3000	DNSMessage ack;
3001	mDNSu8 *ackEnd = ack.data;
3002	mStatus err;
3003	LLQOptData opt;
3004
3005	(void)InterfaceID;  // unused
3006
3007    // find Opt RR, verify correct ID
3008	if (!getLLQAtIndex(m, msg, end, &opt, 0))  { debugf("Pkt does not contain LLQ Opt");                                   return mDNSfalse; }
3009	if (!q->uDNS_info.llq) { LogMsg("Error: recvLLQEvent - question object does not contain LLQ metadata");                return mDNSfalse; }
3010	if (!sameID(opt.id, q->uDNS_info.llq->id)) {                                                                           return mDNSfalse; }
3011	if (opt.llqOp != kLLQOp_Event) { if (!q->uDNS_info.llq->ntries) LogMsg("recvLLQEvent - Bad LLQ Opcode %d", opt.llqOp); return mDNSfalse; }
3012
3013    // invoke response handler
3014	m->uDNS_info.CurrentQuery = q;
3015	q->uDNS_info.responseCallback(m, msg, end, q, q->uDNS_info.context);
3016	if (m->uDNS_info.CurrentQuery != q) return mDNStrue;
3017
3018    //  format and send ack
3019	InitializeDNSMessage(&ack.h, msg->h.id, ResponseFlags);
3020	ackEnd = putLLQ(&ack, ack.data, mDNSNULL, &opt, mDNSfalse);
3021	if (!ackEnd) { LogMsg("ERROR: recvLLQEvent - putLLQ");  return mDNSfalse; }
3022	err = mDNSSendDNSMessage(m, &ack, ackEnd, mDNSInterface_Any, srcaddr, srcport, -1, mDNSNULL);
3023	if (err) debugf("ERROR: recvLLQEvent - mDNSSendDNSMessage returned %ld", err);
3024	return mDNStrue;
3025	}
3026
3027
3028
3029mDNSlocal void hndlChallengeResponseAck(mDNS *m, DNSMessage *pktMsg, const mDNSu8 *end, LLQOptData *llq, DNSQuestion *q)
3030	{
3031	LLQ_Info *info = q->uDNS_info.llq;
3032
3033	if (llq->err) { LogMsg("hndlChallengeResponseAck - received error %d from server", llq->err); goto error; }
3034	if (!sameID(info->id, llq->id)) { LogMsg("hndlChallengeResponseAck - ID changed.  discarding"); return; } // this can happen rarely (on packet loss + reordering)
3035	info->expire = mDNSPlatformTimeNow(m) + ((mDNSs32)llq->lease * mDNSPlatformOneSecond);
3036	info->retry = info->expire - ((mDNSs32)llq->lease * mDNSPlatformOneSecond / 2);
3037
3038	info->origLease = llq->lease;
3039	info->state = LLQ_Established;
3040
3041	q->uDNS_info.responseCallback = llqResponseHndlr;
3042	llqResponseHndlr(m, pktMsg, end, q, mDNSNULL);
3043	return;
3044
3045	error:
3046	info->state = LLQ_Error;
3047	}
3048
3049mDNSlocal void sendChallengeResponse(mDNS *m, DNSQuestion *q, LLQOptData *llq)
3050	{
3051	LLQ_Info *info = q->uDNS_info.llq;
3052	DNSMessage response;
3053	mDNSu8 *responsePtr = response.data;
3054	mStatus err;
3055	LLQOptData llqBuf;
3056	mDNSs32 timenow = mDNSPlatformTimeNow(m);
3057
3058	if (info->ntries++ == kLLQ_MAX_TRIES)
3059		{
3060		LogMsg("sendChallengeResponse: %d failed attempts for LLQ %##s. Will re-try in %d minutes",
3061			   kLLQ_MAX_TRIES, q->qname.c, kLLQ_DEF_RETRY / 60);
3062		info->state = LLQ_Retry;
3063		info->retry = timenow + (kLLQ_DEF_RETRY * mDNSPlatformOneSecond);
3064		// !!!KRS give a callback error in these cases?
3065		return;
3066		}
3067
3068	if (!llq)
3069		{
3070		llq = &llqBuf;
3071		llq->vers    = kLLQ_Vers;
3072		llq->llqOp   = kLLQOp_Setup;
3073		llq->err     = LLQErr_NoError;
3074		umemcpy(llq->id, info->id, 8);
3075		llq->lease    = info->origLease;
3076		}
3077
3078	q->LastQTime = timenow;
3079	info->retry = timenow  + (kLLQ_INIT_RESEND * info->ntries * mDNSPlatformOneSecond);
3080
3081	if (constructQueryMsg(&response, &responsePtr, q)) goto error;
3082	responsePtr = putLLQ(&response, responsePtr, q, llq, mDNSfalse);
3083	if (!responsePtr) { LogMsg("ERROR: sendChallengeResponse - putLLQ"); goto error; }
3084
3085	err = mDNSSendDNSMessage(m, &response, responsePtr, mDNSInterface_Any, &info->servAddr, info->servPort, -1, mDNSNULL);
3086	if (err) debugf("ERROR: sendChallengeResponse - mDNSSendDNSMessage returned %ld", err);
3087	// on error, we procede as normal and retry after the appropriate interval
3088
3089	return;
3090
3091	error:
3092	info->state = LLQ_Error;
3093	}
3094
3095
3096
3097mDNSlocal void hndlRequestChallenge(mDNS *m, DNSMessage *pktMsg, const mDNSu8 *end, LLQOptData *llq, DNSQuestion *q)
3098	{
3099	LLQ_Info *info = q->uDNS_info.llq;
3100	mDNSs32 timenow = mDNSPlatformTimeNow(m);
3101	switch(llq->err)
3102		{
3103		case LLQErr_NoError: break;
3104		case LLQErr_ServFull:
3105			LogMsg("hndlRequestChallenge - received ServFull from server for LLQ %##s.  Retry in %lu sec", q->qname.c, llq->lease);
3106			info->retry = timenow + ((mDNSs32)llq->lease * mDNSPlatformOneSecond);
3107			info->state = LLQ_Retry;
3108			simpleResponseHndlr(m, pktMsg, end, q, mDNSNULL);  // get available answers
3109			info->deriveRemovesOnResume = mDNStrue;
3110		case LLQErr_Static:
3111			info->state = LLQ_Static;
3112			LogMsg("LLQ %##s: static", q->qname.c);
3113			simpleResponseHndlr(m, pktMsg, end, q, mDNSNULL);
3114			return;
3115		case LLQErr_FormErr:
3116			LogMsg("ERROR: hndlRequestChallenge - received FormErr from server for LLQ %##s", q->qname.c);
3117			goto error;
3118		case LLQErr_BadVers:
3119			LogMsg("ERROR: hndlRequestChallenge - received BadVers from server");
3120			goto error;
3121		case LLQErr_UnknownErr:
3122			LogMsg("ERROR: hndlRequestChallenge - received UnknownErr from server for LLQ %##s", q->qname.c);
3123			goto error;
3124		default:
3125			LogMsg("ERROR: hndlRequestChallenge - received invalid error %d for LLQ %##s", llq->err, q->qname.c);
3126			goto error;
3127		}
3128
3129	if (info->origLease != llq->lease)
3130		debugf("hndlRequestChallenge: requested lease %lu, granted lease %lu", info->origLease, llq->lease);
3131
3132	// cache expiration in case we go to sleep before finishing setup
3133	info->origLease = llq->lease;
3134	info->expire = timenow + ((mDNSs32)llq->lease * mDNSPlatformOneSecond);
3135
3136	// update state
3137	info->state = LLQ_SecondaryRequest;
3138	umemcpy(info->id, llq->id, 8);
3139	info->ntries = 0; // first attempt to send response
3140
3141	sendChallengeResponse(m, q, llq);
3142	return;
3143
3144
3145	error:
3146	info->state = LLQ_Error;
3147	}
3148
3149
3150// response handler for initial and secondary setup responses
3151mDNSlocal void recvSetupResponse(mDNS *m, DNSMessage *pktMsg, const mDNSu8 *end, DNSQuestion *q, void *clientContext)
3152	{
3153	DNSQuestion pktQuestion;
3154	LLQOptData llq;
3155	const mDNSu8 *ptr = pktMsg->data;
3156	LLQ_Info *info = q->uDNS_info.llq;
3157	mDNSu8 rcode = (mDNSu8)(pktMsg->h.flags.b[1] & kDNSFlag1_RC);
3158
3159	(void)clientContext;  // unused
3160
3161	if (rcode && rcode != kDNSFlag1_RC_NXDomain) goto poll;
3162
3163	ptr = getQuestion(pktMsg, ptr, end, 0, &pktQuestion);
3164	if (!ptr) { LogMsg("ERROR: recvSetupResponse - getQuestion"); goto poll; }
3165	if (!SameDomainName(&q->qname, &pktQuestion.qname))
3166		{ LogMsg("ERROR: recvSetupResponse - mismatched question in response for llq setup %##s", q->qname.c);   goto poll; }
3167
3168	if (!getLLQAtIndex(m, pktMsg, end, &llq, 0)) { debugf("recvSetupResponse - GetLLQAtIndex"); goto poll; }
3169	if (llq.llqOp != kLLQOp_Setup) { LogMsg("ERROR: recvSetupResponse - bad op %d", llq.llqOp); goto poll; }
3170	if (llq.vers != kLLQ_Vers) { LogMsg("ERROR: recvSetupResponse - bad vers %d", llq.vers);  goto poll; }
3171
3172	if (info->state == LLQ_InitialRequest) { hndlRequestChallenge(m, pktMsg, end, &llq, q); return; }
3173	if (info->state == LLQ_SecondaryRequest) { hndlChallengeResponseAck(m, pktMsg, end, &llq, q); return; }
3174	LogMsg("recvSetupResponse - bad state %d", info->state);
3175
3176	poll:
3177	info->state = LLQ_Poll;
3178	q->uDNS_info.responseCallback = llqResponseHndlr;
3179	info->question->LastQTime = mDNSPlatformTimeNow(m) - (2 * INIT_UCAST_POLL_INTERVAL);  // trigger immediate poll
3180	info->question->ThisQInterval = INIT_UCAST_POLL_INTERVAL;
3181	}
3182
3183mDNSlocal void startLLQHandshake(mDNS *m, LLQ_Info *info, mDNSBool defer)
3184	{
3185	DNSMessage msg;
3186	mDNSu8 *end;
3187	LLQOptData llqData;
3188	DNSQuestion *q = info->question;
3189	mStatus err = mStatus_NoError;
3190	mDNSs32 timenow = mDNSPlatformTimeNow(m);
3191	uDNS_GlobalInfo *u = &m->uDNS_info;
3192
3193	if (IsPrivateV4Addr(&u->AdvertisedV4))
3194		{
3195		if (!u->LLQNatInfo)
3196			{
3197			info->state = LLQ_NatMapWait;
3198			StartLLQNatMap(m);
3199			return;
3200			}
3201		if (u->LLQNatInfo->state == NATState_Error) goto poll;
3202		if (u->LLQNatInfo->state != NATState_Established && u->LLQNatInfo->state != NATState_Legacy)
3203			{ info->state = LLQ_NatMapWait; info->NATMap = mDNStrue; return; }
3204		info->NATMap = mDNStrue;  // this llq references the global llq nat mapping
3205		}
3206
3207	if (info->ntries++ >= kLLQ_MAX_TRIES)
3208		{
3209		debugf("startLLQHandshake: %d failed attempts for LLQ %##s.  Polling.", kLLQ_MAX_TRIES, q->qname.c, kLLQ_DEF_RETRY / 60);
3210		goto poll;
3211		}
3212
3213    // set llq rdata
3214	llqData.vers    = kLLQ_Vers;
3215	llqData.llqOp   = kLLQOp_Setup;
3216	llqData.err     = LLQErr_NoError;
3217	ubzero(llqData.id, 8);
3218	llqData.lease    = kLLQ_DefLease;
3219
3220	initializeQuery(&msg, q);
3221	end = putLLQ(&msg, msg.data, q, &llqData, mDNStrue);
3222	if (!end)
3223		{
3224		LogMsg("ERROR: startLLQHandshake - putLLQ");
3225		info->state = LLQ_Error;
3226		return;
3227		}
3228
3229	if (!defer) // if we are to defer, we simply set the retry timers so the request goes out in the future
3230		{
3231		err = mDNSSendDNSMessage(m, &msg, end, mDNSInterface_Any, &info->servAddr, info->servPort, -1, mDNSNULL);
3232		if (err) debugf("ERROR: startLLQHandshake - mDNSSendDNSMessage returned %ld", err);
3233		// on error, we procede as normal and retry after the appropriate interval
3234		}
3235
3236	// update question/info state
3237	info->state = LLQ_InitialRequest;
3238	info->origLease = kLLQ_DefLease;
3239    info->retry = timenow + (kLLQ_INIT_RESEND * mDNSPlatformOneSecond);
3240	q->LastQTime = timenow;
3241	q->uDNS_info.responseCallback = recvSetupResponse;
3242	q->uDNS_info.internal = mDNStrue;
3243	return;
3244
3245	poll:
3246	info->question->uDNS_info.responseCallback = llqResponseHndlr;
3247	info->state = LLQ_Poll;
3248	info->question->LastQTime = mDNSPlatformTimeNow(m) - (2 * INIT_UCAST_POLL_INTERVAL);  // trigger immediate poll
3249	info->question->ThisQInterval = INIT_UCAST_POLL_INTERVAL;
3250	}
3251
3252// wrapper for startLLQHandshake, invoked by async op callback
3253mDNSlocal void startLLQHandshakeCallback(mStatus err, mDNS *const m, void *llqInfo, const AsyncOpResult *result)
3254	{
3255	LLQ_Info *info = (LLQ_Info *)llqInfo;
3256	const zoneData_t *zoneInfo = mDNSNULL;
3257
3258    // check state first to make sure it is OK to touch question object
3259	if (info->state == LLQ_Cancelled)
3260		{
3261		// StopQuery was called while we were getting the zone info
3262		debugf("startLLQHandshake - LLQ Cancelled.");
3263		info->question = mDNSNULL;  // question may be deallocated
3264		ufree(info);
3265		return;
3266		}
3267
3268	if (!info->question)
3269		{ LogMsg("ERROR: startLLQHandshakeCallback invoked with NULL question"); goto error; }
3270
3271	if (info->state != LLQ_GetZoneInfo)
3272		{ LogMsg("ERROR: startLLQHandshake - bad state %d", info->state); goto error; }
3273
3274	if (err)
3275		{ LogMsg("ERROR: startLLQHandshakeCallback %##s invoked with error code %ld", info->question->qname.c, err); goto poll; }
3276
3277	if (!result)
3278		{ LogMsg("ERROR: startLLQHandshakeCallback invoked with NULL result and no error code"); goto error; }
3279
3280	zoneInfo = &result->zoneData;
3281
3282	if (!zoneInfo->llqPort.NotAnInteger)
3283		{ debugf("LLQ port lookup failed - reverting to polling"); info->servPort.NotAnInteger = 0; goto poll; }
3284
3285    // cache necessary zone data
3286	info->servAddr = zoneInfo->primaryAddr;
3287	info->servPort = zoneInfo->llqPort;
3288    info->ntries = 0;
3289
3290	if (info->state == LLQ_SuspendDeferred) info->state = LLQ_Suspended;
3291	else startLLQHandshake(m, info, mDNSfalse);
3292	return;
3293
3294	poll:
3295	info->question->uDNS_info.responseCallback = llqResponseHndlr;
3296	info->state = LLQ_Poll;
3297	info->question->LastQTime = mDNSPlatformTimeNow(m) - (2 * INIT_UCAST_POLL_INTERVAL);  // trigger immediate poll
3298	info->question->ThisQInterval = INIT_UCAST_POLL_INTERVAL;
3299	return;
3300
3301	error:
3302	info->state = LLQ_Error;
3303	}
3304
3305mDNSlocal mStatus startLLQ(mDNS *m, DNSQuestion *question)
3306    {
3307	LLQ_Info *info;
3308	mStatus err = mStatus_NoError;
3309
3310	// allocate / init info struct
3311    info = umalloc(sizeof(LLQ_Info));
3312    if (!info) { LogMsg("ERROR: startLLQ - malloc"); return mStatus_NoMemoryErr; }
3313	ubzero(info, sizeof(LLQ_Info));
3314    info->state = LLQ_GetZoneInfo;
3315
3316	// link info/question
3317	info->question = question;
3318	question->uDNS_info.llq = info;
3319
3320	question->uDNS_info.responseCallback = llqResponseHndlr;
3321
3322	err = startGetZoneData(&question->qname, m, mDNSfalse, mDNStrue, startLLQHandshakeCallback, info);
3323    if (err)
3324		{
3325		LogMsg("ERROR: startLLQ - startGetZoneData returned %ld", err);
3326		info->question = mDNSNULL;
3327		ufree(info);
3328		question->uDNS_info.llq = mDNSNULL;
3329		return err;
3330		}
3331
3332	LinkActiveQuestion(&m->uDNS_info, question);
3333	return err;
3334	}
3335
3336mDNSlocal mDNSBool recvLLQResponse(mDNS *m, DNSMessage *msg, const mDNSu8 *end, const mDNSAddr *srcaddr, mDNSIPPort srcport, const mDNSInterfaceID InterfaceID)
3337	{
3338	DNSQuestion pktQ, *q;
3339	uDNS_GlobalInfo *u = &m->uDNS_info;
3340	const mDNSu8 *ptr = msg->data;
3341	LLQ_Info *llqInfo;
3342
3343	if (!msg->h.numQuestions) return mDNSfalse;
3344
3345	ptr = getQuestion(msg, ptr, end, 0, &pktQ);
3346	if (!ptr) return mDNSfalse;
3347	pktQ.uDNS_info.id = msg->h.id;
3348
3349	q = u->ActiveQueries;
3350	while (q)
3351		{
3352		llqInfo = q->uDNS_info.llq;
3353		if (q->LongLived &&
3354			llqInfo &&
3355			q->qnamehash == pktQ.qnamehash &&
3356			q->qtype == pktQ.qtype &&
3357			SameDomainName(&q->qname, &pktQ.qname))
3358			{
3359			u->CurrentQuery = q;
3360			if (llqInfo->state == LLQ_Established || (llqInfo->state == LLQ_Refresh && msg->h.numAnswers))
3361				{ if (recvLLQEvent(m, q, msg, end, srcaddr, srcport, InterfaceID)) return mDNStrue; }
3362			else if (msg->h.id.NotAnInteger == q->uDNS_info.id.NotAnInteger)
3363				{
3364				if (llqInfo->state == LLQ_Refresh && msg->h.numAdditionals && !msg->h.numAnswers)
3365					{ recvRefreshReply(m, msg, end, q); return mDNStrue; }
3366				if (llqInfo->state < LLQ_Static)
3367					{
3368					if ((llqInfo->state != LLQ_InitialRequest && llqInfo->state != LLQ_SecondaryRequest) || mDNSSameAddress(srcaddr, &llqInfo->servAddr))
3369						{ q->uDNS_info.responseCallback(m, msg, end, q, q->uDNS_info.context); return mDNStrue; }
3370					}
3371				}
3372			}
3373		q = q->next;
3374		}
3375	return mDNSfalse;
3376	}
3377
3378mDNSexport mDNSBool uDNS_IsActiveQuery(DNSQuestion *const question, uDNS_GlobalInfo *u)
3379    {
3380	DNSQuestion *q;
3381
3382	for (q = u->ActiveQueries; q; q = q->next)
3383		{
3384		if (q == question)
3385			{
3386			if (!question->uDNS_info.id.NotAnInteger || question->InterfaceID == mDNSInterface_LocalOnly || IsLocalDomain(&question->qname))
3387				LogMsg("Warning: Question %##s in Active Unicast Query list with id %d, interfaceID %p",
3388					   question->qname.c, question->uDNS_info.id.NotAnInteger, question->InterfaceID);
3389			return mDNStrue;
3390			}
3391		}
3392	return mDNSfalse;
3393	}
3394
3395// stopLLQ happens IN ADDITION to stopQuery
3396mDNSlocal void stopLLQ(mDNS *m, DNSQuestion *question)
3397	{
3398	LLQ_Info *info = question->uDNS_info.llq;
3399	(void)m;  // unused
3400
3401	if (!question->LongLived) { LogMsg("ERROR: stopLLQ - LongLived flag not set"); return; }
3402	if (!info)                { LogMsg("ERROR: stopLLQ - llq info is NULL");       return; }
3403
3404	switch (info->state)
3405		{
3406		case LLQ_UnInit:
3407			LogMsg("ERROR: stopLLQ - state LLQ_UnInit");
3408			//!!!KRS should we unlink info<->question here?
3409			return;
3410		case LLQ_GetZoneInfo:
3411		case LLQ_SuspendDeferred:
3412			info->question = mDNSNULL; // remove ref to question, as it may be freed when we get called back from async op
3413			info->state = LLQ_Cancelled;
3414			return;
3415		case LLQ_Established:
3416		case LLQ_Refresh:
3417			// refresh w/ lease 0
3418			sendLLQRefresh(m, question, 0);
3419			goto end;
3420		default:
3421			debugf("stopLLQ - silently discarding LLQ in state %d", info->state);
3422			goto end;
3423		}
3424
3425	end:
3426	if (info->NATMap) info->NATMap = mDNSfalse;
3427	CheckForUnreferencedLLQMapping(m);
3428	info->question = mDNSNULL;
3429	ufree(info);
3430	question->uDNS_info.llq = mDNSNULL;
3431	question->LongLived = mDNSfalse;
3432	}
3433
3434mDNSexport mStatus uDNS_StopQuery(mDNS *const m, DNSQuestion *const question)
3435	{
3436	uDNS_GlobalInfo *u = &m->uDNS_info;
3437	DNSQuestion *qptr, *prev = mDNSNULL;
3438	CacheRecord *ka;
3439
3440	qptr = u->ActiveQueries;
3441	while (qptr)
3442        {
3443        if (qptr == question)
3444            {
3445			if (question->LongLived && question->uDNS_info.llq)
3446				stopLLQ(m, question);
3447			if (m->uDNS_info.CurrentQuery == question)
3448				m->uDNS_info.CurrentQuery = m->uDNS_info.CurrentQuery->next;
3449			while (question->uDNS_info.knownAnswers)
3450				{
3451				ka = question->uDNS_info.knownAnswers;
3452				question->uDNS_info.knownAnswers = question->uDNS_info.knownAnswers->next;
3453				ufree(ka);
3454				}
3455			if (prev) prev->next = question->next;
3456            else u->ActiveQueries = question->next;
3457			return mStatus_NoError;
3458            }
3459        prev = qptr;
3460		qptr = qptr->next;
3461        }
3462    LogMsg("uDNS_StopQuery: no such active query (%##s)", question->qname.c);
3463    return mStatus_UnknownErr;
3464    }
3465
3466mDNSlocal mStatus startQuery(mDNS *const m, DNSQuestion *const question, mDNSBool internal)
3467    {
3468    uDNS_GlobalInfo *u = &m->uDNS_info;
3469    //!!!KRS we should check if the question is already in our activequestion list
3470	if (!ValidateDomainName(&question->qname))
3471		{
3472		LogMsg("Attempt to start query with invalid qname %##s (%s)", question->qname.c, DNSTypeName(question->qtype));
3473		return mStatus_Invalid;
3474		}
3475
3476	question->next = mDNSNULL;
3477	question->qnamehash = DomainNameHashValue(&question->qname);    // to do quick domain name comparisons
3478    question->uDNS_info.id = newMessageID(u);
3479	question->uDNS_info.Answered = mDNSfalse;
3480
3481	// break here if its and LLQ
3482	if (question->LongLived) return startLLQ(m, question);
3483
3484	question->ThisQInterval = INIT_UCAST_POLL_INTERVAL / 2;
3485	question->LastQTime = mDNSPlatformTimeNow(m) - question->ThisQInterval;
3486    // store the question/id in active question list
3487	question->uDNS_info.internal = internal;
3488	LinkActiveQuestion(u, question);
3489	question->uDNS_info.knownAnswers = mDNSNULL;
3490	LogOperation("uDNS startQuery: %##s (%s)", question->qname.c, DNSTypeName(question->qtype));
3491
3492	return mStatus_NoError;
3493	}
3494
3495mDNSexport mStatus uDNS_StartQuery(mDNS *const m, DNSQuestion *const question)
3496    {
3497	ubzero(&question->uDNS_info, sizeof(uDNS_QuestionInfo));
3498	question->uDNS_info.responseCallback = simpleResponseHndlr;
3499	question->uDNS_info.context = mDNSNULL;
3500	//LogOperation("uDNS_StartQuery %##s (%s)", question->qname.c, DNSTypeName(question->qtype));
3501	return startQuery(m, question, 0);
3502    }
3503
3504// explicitly set response handler
3505mDNSlocal mStatus startInternalQuery(DNSQuestion *q, mDNS *m, InternalResponseHndlr callback, void *hndlrContext)
3506    {
3507	ubzero(&q->uDNS_info, sizeof(uDNS_QuestionInfo));
3508    q->QuestionContext = hndlrContext;
3509    q->uDNS_info.responseCallback = callback;
3510	q->uDNS_info.context = hndlrContext;
3511    return startQuery(m, q, 1);
3512    }
3513
3514
3515
3516// ***************************************************************************
3517#if COMPILER_LIKES_PRAGMA_MARK
3518#pragma mark - Domain -> Name Server Conversion
3519#endif
3520
3521
3522/* startGetZoneData
3523 *
3524 * Asynchronously find the address of the nameserver for the enclosing zone for a given domain name,
3525 * i.e. the server to which update and LLQ requests will be sent for a given name.  Once the address is
3526 * derived, it will be passed to the callback, along with a context pointer.  If the zone cannot
3527 * be determined or if an error occurs, an all-zeros address will be passed and a message will be
3528 * written to the syslog.
3529 *
3530 * If the FindUpdatePort arg is set, the port on which the server accepts dynamic updates is determined
3531 * by querying for the _dns-update._udp.<zone>. SRV record.  Likewise, if the FindLLQPort arg is set,
3532 * the port on which the server accepts long lived queries is determined by querying for
3533 * _dns-llq._udp.<zone>. record.  If either of these queries fail, or flags are not specified,
3534 * the llqPort and updatePort fields in the result structure are set to zero.
3535 *
3536 *  Steps for deriving the zone name are as follows:
3537 *
3538 * Query for an SOA record for the required domain.  If we don't get an answer (or an SOA in the Authority
3539 * section), we strip the leading label from the name and repeat, until we get an answer.
3540 *
3541 * The name of the SOA record is our enclosing zone.  The mname field in the SOA rdata is the domain
3542 * name of the primary NS.
3543 *
3544 * We verify that there is an NS record with this zone for a name and the mname for its rdata.
3545 * (!!!KRS this seems redundant, but BIND does this, and it should normally be zero-overhead since
3546 * the NS query will get us address records in the additionals section, which we'd otherwise have to
3547 * explicitly query for.)
3548 *
3549 * We then query for the address record for this nameserver (if it is not in the addionals section of
3550 * the NS record response.)
3551 */
3552
3553
3554// state machine types and structs
3555//
3556
3557// state machine states
3558typedef enum
3559    {
3560    init,
3561    lookupSOA,
3562	foundZone,
3563	lookupNS,
3564	foundNS,
3565	lookupA,
3566	foundA,
3567	lookupPort,
3568	foundPort,
3569	complete
3570    } ntaState;
3571
3572// state machine actions
3573typedef enum
3574    {
3575    smContinue,  // continue immediately to next state
3576    smBreak,     // break until next packet/timeout
3577	smError      // terminal error - cleanup and abort
3578    } smAction;
3579
3580typedef struct
3581    {
3582    domainname 	origName;            // name we originally try to convert
3583    domainname 	*curSOA;             // name we have an outstanding SOA query for
3584    ntaState  	state;               // determines what we do upon receiving a packet
3585    mDNS	    *m;
3586    domainname  zone;                // left-hand-side of SOA record
3587    mDNSu16     zoneClass;
3588    domainname  ns;                  // mname in SOA rdata, verified in confirmNS state
3589    mDNSv4Addr  addr;                // address of nameserver
3590    DNSQuestion question;            // storage for any active question
3591    DNSQuestion extraQuestion;       // additional storage
3592    mDNSBool    questionActive;      // if true, StopQuery() can be called on the question field
3593    mDNSBool    findUpdatePort;
3594    mDNSBool    findLLQPort;
3595    mDNSIPPort  updatePort;
3596    mDNSIPPort  llqPort;
3597    AsyncOpCallback *callback;       // caller specified function to be called upon completion
3598    void        *callbackInfo;
3599    } ntaContext;
3600
3601
3602// function prototypes (for routines that must be used as fn pointers prior to their definitions,
3603// and allows states to be read top-to-bottom in logical order)
3604mDNSlocal void getZoneData(mDNS *const m, DNSMessage *msg, const mDNSu8 *end, DNSQuestion *question, void *contextPtr);
3605mDNSlocal smAction hndlLookupSOA(DNSMessage *msg, const mDNSu8 *end, ntaContext *context);
3606mDNSlocal void processSOA(ntaContext *context, ResourceRecord *rr);
3607mDNSlocal smAction confirmNS(DNSMessage *msg, const mDNSu8 *end, ntaContext *context);
3608mDNSlocal smAction lookupNSAddr(DNSMessage *msg, const mDNSu8 *end, ntaContext *context);
3609mDNSlocal smAction hndlLookupPorts(DNSMessage *msg, const mDNSu8 *end, ntaContext *context);
3610
3611// initialization
3612mDNSlocal mStatus startGetZoneData(domainname *name, mDNS *m, mDNSBool findUpdatePort, mDNSBool findLLQPort,
3613								   AsyncOpCallback callback, void *callbackInfo)
3614    {
3615    ntaContext *context = (ntaContext*)umalloc(sizeof(ntaContext));
3616    if (!context) { LogMsg("ERROR: startGetZoneData - umalloc failed");  return mStatus_NoMemoryErr; }
3617	ubzero(context, sizeof(ntaContext));
3618    AssignDomainName(&context->origName, name);
3619    context->state = init;
3620    context->m = m;
3621	context->callback = callback;
3622	context->callbackInfo = callbackInfo;
3623	context->findUpdatePort = findUpdatePort;
3624	context->findLLQPort = findLLQPort;
3625    getZoneData(m, mDNSNULL, mDNSNULL, mDNSNULL, context);
3626    return mStatus_NoError;
3627    }
3628
3629// state machine entry routine
3630mDNSlocal void getZoneData(mDNS *const m, DNSMessage *msg, const mDNSu8 *end, DNSQuestion *question, void *contextPtr)
3631    {
3632	AsyncOpResult result;
3633	ntaContext *context = (ntaContext*)contextPtr;
3634	smAction action;
3635
3636    // unused
3637	(void)m;
3638	(void)question;
3639
3640	// stop any active question
3641	if (context->questionActive)
3642		{
3643		uDNS_StopQuery(context->m, &context->question);
3644		context->questionActive = mDNSfalse;
3645		}
3646
3647	if (msg && msg->h.flags.b[2] >> 4 && msg->h.flags.b[2] >> 4 != kDNSFlag1_RC_NXDomain)
3648		{
3649		// rcode non-zero, non-nxdomain
3650		LogMsg("ERROR: getZoneData - received response w/ rcode %d", msg->h.flags.b[2] >> 4);
3651		goto error;
3652		}
3653
3654	switch (context->state)
3655        {
3656        case init:
3657        case lookupSOA:
3658            action = hndlLookupSOA(msg, end, context);
3659			if (action == smError) goto error;
3660			if (action == smBreak) return;
3661		case foundZone:
3662		case lookupNS:
3663			action = confirmNS(msg, end, context);
3664			if (action == smError) goto error;
3665			if (action == smBreak) return;
3666		case foundNS:
3667		case lookupA:
3668			action = lookupNSAddr(msg, end, context);
3669			if (action == smError) goto error;
3670			if (action == smBreak) return;
3671		case foundA:
3672			if (!context->findUpdatePort && !context->findLLQPort)
3673				{
3674				context->state = complete;
3675				break;
3676				}
3677		case lookupPort:
3678			action = hndlLookupPorts(msg, end, context);
3679			if (action == smError) goto error;
3680			if (action == smBreak) return;
3681			if (action == smContinue) context->state = complete;
3682		case foundPort:
3683		case complete: break;
3684		}
3685
3686	if (context->state != complete)
3687		{
3688		LogMsg("ERROR: getZoneData - exited state machine with state %d", context->state);
3689		goto error;
3690		}
3691
3692	result.type = zoneDataResult;
3693	result.zoneData.primaryAddr.ip.v4 = context->addr;
3694	result.zoneData.primaryAddr.type = mDNSAddrType_IPv4;
3695	AssignDomainName(&result.zoneData.zoneName, &context->zone);
3696	result.zoneData.zoneClass = context->zoneClass;
3697
3698	if (context->findLLQPort)
3699		result.zoneData.llqPort = context->llqPort;
3700	else
3701		result.zoneData.llqPort = zeroIPPort;
3702
3703	if (context->findUpdatePort)
3704		result.zoneData.updatePort = context->updatePort;
3705        else
3706		result.zoneData.updatePort = zeroIPPort;
3707
3708	context->callback(mStatus_NoError, context->m, context->callbackInfo, &result);
3709	goto cleanup;
3710
3711error:
3712	if (context && context->callback)
3713		context->callback(mStatus_UnknownErr, context->m, context->callbackInfo, mDNSNULL);
3714cleanup:
3715	if (context && context->questionActive)
3716		{
3717		uDNS_StopQuery(context->m, &context->question);
3718		context->questionActive = mDNSfalse;
3719		}
3720    if (context) ufree(context);
3721	}
3722
3723mDNSlocal smAction hndlLookupSOA(DNSMessage *msg, const mDNSu8 *end, ntaContext *context)
3724    {
3725    mStatus err;
3726    LargeCacheRecord lcr;
3727	ResourceRecord *rr = &lcr.r.resrec;
3728	DNSQuestion *query = &context->question;
3729	const mDNSu8 *ptr;
3730
3731    if (msg)
3732        {
3733        // if msg contains SOA record in answer or authority sections, update context/state and return
3734		int i;
3735		ptr = LocateAnswers(msg, end);
3736		for (i = 0; i < msg->h.numAnswers; i++)
3737			{
3738			ptr = GetLargeResourceRecord(context->m, msg, ptr, end, 0, kDNSRecordTypePacketAns, &lcr);
3739			if (!ptr) { LogMsg("ERROR: hndlLookupSOA, Answers - GetLargeResourceRecord returned NULL");  return smError; }
3740			if (rr->rrtype == kDNSType_SOA && SameDomainName(context->curSOA, rr->name))
3741				{
3742				processSOA(context, rr);
3743				return smContinue;
3744				}
3745			}
3746		ptr = LocateAuthorities(msg, end);
3747		// SOA not in answers, check in authority
3748		for (i = 0; i < msg->h.numAuthorities; i++)
3749			{
3750			ptr = GetLargeResourceRecord(context->m, msg, ptr, end, 0, kDNSRecordTypePacketAns, &lcr); ///!!!KRS using type PacketAns for auth
3751			if (!ptr) { LogMsg("ERROR: hndlLookupSOA, Authority - GetLargeResourceRecord returned NULL");  return smError; }
3752			if (rr->rrtype == kDNSType_SOA)
3753				{
3754				processSOA(context, rr);
3755				return smContinue;
3756				}
3757			}
3758		}
3759
3760    if (context->state != init && !context->curSOA->c[0])
3761        {
3762        // we've gone down to the root and have not found an SOA
3763        LogMsg("ERROR: hndlLookupSOA - recursed to root label of %##s without finding SOA",
3764                context->origName.c);
3765		return smError;
3766        }
3767
3768    ubzero(query, sizeof(DNSQuestion));
3769    // chop off leading label unless this is our first try
3770    if (context->state == init)  context->curSOA = &context->origName;
3771    else                         context->curSOA = (domainname *)(context->curSOA->c + context->curSOA->c[0]+1);
3772
3773    context->state = lookupSOA;
3774    AssignDomainName(&query->qname, context->curSOA);
3775    query->qtype = kDNSType_SOA;
3776    query->qclass = kDNSClass_IN;
3777    err = startInternalQuery(query, context->m, getZoneData, context);
3778	context->questionActive = mDNStrue;
3779	if (err) LogMsg("hndlLookupSOA: startInternalQuery returned error %ld (breaking until next periodic retransmission)", err);
3780
3781    return smBreak;     // break from state machine until we receive another packet
3782    }
3783
3784mDNSlocal void processSOA(ntaContext *context, ResourceRecord *rr)
3785	{
3786	AssignDomainName(&context->zone, rr->name);
3787	context->zoneClass = rr->rrclass;
3788	AssignDomainName(&context->ns, &rr->rdata->u.soa.mname);
3789	context->state = foundZone;
3790	}
3791
3792
3793mDNSlocal smAction confirmNS(DNSMessage *msg, const mDNSu8 *end, ntaContext *context)
3794	{
3795	DNSQuestion *query = &context->question;
3796	mStatus err;
3797	LargeCacheRecord lcr;
3798	const ResourceRecord *const rr = &lcr.r.resrec;
3799	const mDNSu8 *ptr;
3800	int i;
3801
3802	if (context->state == foundZone)
3803		{
3804		// we've just learned the zone.  confirm that an NS record exists
3805		AssignDomainName(&query->qname, &context->zone);
3806		query->qtype = kDNSType_NS;
3807		query->qclass = kDNSClass_IN;
3808		err = startInternalQuery(query, context->m, getZoneData, context);
3809		context->questionActive = mDNStrue;
3810		if (err) LogMsg("confirmNS: startInternalQuery returned error %ld (breaking until next periodic retransmission", err);
3811		context->state = lookupNS;
3812		return smBreak;  // break from SM until we receive another packet
3813		}
3814	else if (context->state == lookupNS)
3815		{
3816		ptr = LocateAnswers(msg, end);
3817		for (i = 0; i < msg->h.numAnswers; i++)
3818			{
3819			ptr = GetLargeResourceRecord(context->m, msg, ptr, end, 0, kDNSRecordTypePacketAns, &lcr);
3820			if (!ptr) { LogMsg("ERROR: confirmNS, Answers - GetLargeResourceRecord returned NULL");  return smError; }
3821			if (rr->rrtype == kDNSType_NS &&
3822				SameDomainName(&context->zone, rr->name) && SameDomainName(&context->ns, &rr->rdata->u.name))
3823				{
3824				context->state = foundNS;
3825				return smContinue;  // next routine will examine additionals section of A record
3826				}
3827			}
3828		debugf("ERROR: could not confirm existence of record %##s NS %##s", context->zone.c, context->ns.c);
3829		return smError;
3830		}
3831	else { LogMsg("ERROR: confirmNS - bad state %d", context->state); return smError; }
3832	}
3833
3834mDNSlocal smAction queryNSAddr(ntaContext *context)
3835	{
3836	mStatus err;
3837	DNSQuestion *query = &context->question;
3838
3839	AssignDomainName(&query->qname, &context->ns);
3840	query->qtype = kDNSType_A;
3841	query->qclass = kDNSClass_IN;
3842	err = startInternalQuery(query, context->m, getZoneData, context);
3843	context->questionActive = mDNStrue;
3844	if (err) LogMsg("confirmNS: startInternalQuery returned error %ld (breaking until next periodic retransmission)", err);
3845	context->state = lookupA;
3846	return smBreak;
3847	}
3848
3849mDNSlocal smAction lookupNSAddr(DNSMessage *msg, const mDNSu8 *end, ntaContext *context)
3850	{
3851	const mDNSu8 *ptr;
3852	int i;
3853	LargeCacheRecord lcr;
3854	ResourceRecord *rr = &lcr.r.resrec;
3855
3856	if (context->state == foundNS)
3857		{
3858		// we just found the NS record - look for the corresponding A record in the Additionals section
3859		if (!msg->h.numAdditionals) return queryNSAddr(context);
3860		ptr = LocateAdditionals(msg, end);
3861		if (!ptr)
3862			{
3863			LogMsg("ERROR: lookupNSAddr - LocateAdditionals returned NULL, expected %d additionals", msg->h.numAdditionals);
3864			return queryNSAddr(context);
3865			}
3866		else
3867			{
3868			for (i = 0; i < msg->h.numAdditionals; i++)
3869				{
3870				ptr = GetLargeResourceRecord(context->m, msg, ptr, end, 0, kDNSRecordTypePacketAns, &lcr);
3871				if (!ptr)
3872					{
3873					LogMsg("ERROR: lookupNSAddr, Additionals - GetLargeResourceRecord returned NULL");
3874					return queryNSAddr(context);
3875					}
3876				if (rr->rrtype == kDNSType_A && SameDomainName(&context->ns, rr->name))
3877					{
3878					context->addr = rr->rdata->u.ipv4;
3879					context->state = foundA;
3880					return smContinue;
3881					}
3882				}
3883			}
3884		// no A record in Additionals - query the server
3885		return queryNSAddr(context);
3886		}
3887	else if (context->state == lookupA)
3888		{
3889		ptr = LocateAnswers(msg, end);
3890		if (!ptr) { LogMsg("ERROR: lookupNSAddr: LocateAnswers returned NULL");  return smError; }
3891		for (i = 0; i < msg->h.numAnswers; i++)
3892			{
3893			ptr = GetLargeResourceRecord(context->m, msg, ptr, end, 0, kDNSRecordTypePacketAns, &lcr);
3894			if (!ptr) { LogMsg("ERROR: lookupNSAddr, Answers - GetLargeResourceRecord returned NULL"); break; }
3895			if (rr->rrtype == kDNSType_A && SameDomainName(&context->ns, rr->name))
3896				{
3897				context->addr = rr->rdata->u.ipv4;
3898				context->state = foundA;
3899				return smContinue;
3900				}
3901			}
3902		LogMsg("ERROR: lookupNSAddr: Address record not found in answer section");
3903		return smError;
3904		}
3905	else { LogMsg("ERROR: lookupNSAddr - bad state %d", context->state); return smError; }
3906	}
3907
3908mDNSlocal smAction lookupDNSPort(DNSMessage *msg, const mDNSu8 *end, ntaContext *context, char *portName, mDNSIPPort *port)
3909	{
3910	int i;
3911	LargeCacheRecord lcr;
3912	const mDNSu8 *ptr;
3913	DNSQuestion *q;
3914	mStatus err;
3915
3916	if (context->state == lookupPort)  // we've already issued the query
3917		{
3918		if (!msg) { LogMsg("ERROR: hndlLookupUpdatePort - NULL message"); return smError; }
3919		ptr = LocateAnswers(msg, end);
3920		for (i = 0; i < msg->h.numAnswers; i++)
3921			{
3922			ptr = GetLargeResourceRecord(context->m, msg, ptr, end, 0, kDNSRecordTypePacketAns, &lcr);
3923			if (!ptr) { LogMsg("ERROR: hndlLookupUpdatePort - GetLargeResourceRecord returned NULL");  return smError; }
3924			if (ResourceRecordAnswersQuestion(&lcr.r.resrec, &context->question))
3925				{
3926				*port = lcr.r.resrec.rdata->u.srv.port;
3927				context->state = foundPort;
3928				return smContinue;
3929				}
3930			}
3931		debugf("hndlLookupUpdatePort - no answer for type %s", portName);
3932		port->NotAnInteger = 0;
3933		context->state = foundPort;
3934		return smContinue;
3935		}
3936
3937	// query the server for the update port for the zone
3938	context->state = lookupPort;
3939	q = &context->question;
3940	MakeDomainNameFromDNSNameString(&q->qname, portName);
3941	AppendDomainName(&q->qname, &context->zone);
3942    q->qtype = kDNSType_SRV;
3943    q->qclass = kDNSClass_IN;
3944    err = startInternalQuery(q, context->m, getZoneData, context);
3945	context->questionActive = mDNStrue;
3946    if (err) LogMsg("hndlLookupSOA: startInternalQuery returned error %ld (breaking until next periodic retransmission)", err);
3947    return smBreak;     // break from state machine until we receive another packet
3948	}
3949
3950mDNSlocal smAction hndlLookupPorts(DNSMessage *msg, const mDNSu8 *end, ntaContext *context)
3951	{
3952	smAction action;
3953
3954	if (context->findUpdatePort && !context->updatePort.NotAnInteger)
3955		{
3956		action = lookupDNSPort(msg, end, context, UPDATE_PORT_NAME, &context->updatePort);
3957		if (action != smContinue) return action;
3958		}
3959	if (context->findLLQPort && !context->llqPort.NotAnInteger)
3960		return lookupDNSPort(msg, end, context, LLQ_PORT_NAME, &context->llqPort);
3961
3962	return smContinue;
3963	}
3964
3965
3966// ***************************************************************************
3967#if COMPILER_LIKES_PRAGMA_MARK
3968#pragma mark - Truncation Handling
3969#endif
3970
3971typedef struct
3972	{
3973    DNSQuestion  *question;
3974    DNSMessage *reply;
3975    mDNSu16  replylen;
3976    int nread;
3977    mDNS *m;
3978	} tcpInfo_t;
3979
3980// issue queries over a conected socket
3981mDNSlocal void conQueryCallback(int sd, void *context, mDNSBool ConnectionEstablished)
3982	{
3983	mStatus err = 0;
3984	char msgbuf[356];  // 96 (hdr) + 256 (domain) + 4 (class/type)
3985	DNSMessage *msg;
3986	mDNSu8 *end;
3987	tcpInfo_t *info = (tcpInfo_t *)context;
3988	DNSQuestion *question = info->question;
3989	int n;
3990	mDNS *m = info->m;
3991
3992	mDNS_Lock(m);
3993
3994	if (ConnectionEstablished)
3995		{
3996		// connection is established - send the message
3997		msg = (DNSMessage *)&msgbuf;
3998		err = constructQueryMsg(msg, &end, question);
3999		if (err) { LogMsg("ERROR: conQueryCallback: constructQueryMsg - %ld", err);  goto error; }
4000		err = mDNSSendDNSMessage(m, msg, end, mDNSInterface_Any, &zeroAddr, zeroIPPort, sd, mDNSNULL);
4001		question->LastQTime = mDNSPlatformTimeNow(m);
4002		if (err) { debugf("ERROR: conQueryCallback: mDNSSendDNSMessage_tcp - %ld", err);  goto error; }
4003		}
4004	else
4005		{
4006		if (!info->nread)
4007			{
4008			// read msg len
4009			mDNSu8 lenbuf[2];
4010			n = mDNSPlatformReadTCP(sd, lenbuf, 2);
4011			if (n != 2)
4012				{
4013				LogMsg("ERROR:conQueryCallback - attempt to read message length failed (read returned %d)", n);
4014				goto error;
4015				}
4016			info->replylen = (mDNSu16)((mDNSu16)lenbuf[0] << 8 | lenbuf[1]);
4017			if (info->replylen < sizeof(DNSMessageHeader))
4018				{ LogMsg("ERROR: conQueryCallback - length too short (%d bytes)", info->replylen);  goto error; }
4019			info->reply = umalloc(info->replylen);
4020			if (!info->reply) { LogMsg("ERROR: conQueryCallback - malloc failed"); goto error; }
4021			}
4022		n = mDNSPlatformReadTCP(sd, ((char *)info->reply) + info->nread, info->replylen - info->nread);
4023		if (n < 0) { LogMsg("ERROR: conQueryCallback - read returned %d", n); goto error; }
4024		info->nread += n;
4025		if (info->nread == info->replylen)
4026			{
4027			// Finished reading message; convert the integer parts which are in IETF byte-order (MSB first, LSB second)
4028			DNSMessage *msg = info->reply;
4029			mDNSu8 *ptr = (mDNSu8 *)&msg->h.numQuestions;
4030			msg->h.numQuestions   = (mDNSu16)((mDNSu16)ptr[0] << 8 | ptr[1]);
4031			msg->h.numAnswers     = (mDNSu16)((mDNSu16)ptr[2] << 8 | ptr[3]);
4032			msg->h.numAuthorities = (mDNSu16)((mDNSu16)ptr[4] << 8 | ptr[5]);
4033			msg->h.numAdditionals = (mDNSu16)((mDNSu16)ptr[6] << 8 | ptr[7]);
4034			uDNS_ReceiveMsg(m, msg, (mDNSu8 *)msg + info->replylen, mDNSNULL, zeroIPPort, mDNSNULL, zeroIPPort, question->InterfaceID);
4035			mDNSPlatformTCPCloseConnection(sd);
4036			ufree(info->reply);
4037			ufree(info);
4038			}
4039		}
4040
4041	mDNS_Unlock(m);
4042	return;
4043
4044	error:
4045	mDNSPlatformTCPCloseConnection(sd);
4046	if (info->reply) ufree(info->reply);
4047	ufree(info);
4048	mDNS_Unlock(m);
4049	}
4050
4051mDNSlocal void hndlTruncatedAnswer(DNSQuestion *question, const  mDNSAddr *src, mDNS *m)
4052	{
4053	mStatus connectionStatus;
4054	uDNS_QuestionInfo *info = &question->uDNS_info;
4055	int sd;
4056	tcpInfo_t *context;
4057
4058	if (!src) { LogMsg("hndlTruncatedAnswer: TCP DNS response had TC bit set: ignoring"); return; }
4059
4060	context = (tcpInfo_t *)umalloc(sizeof(tcpInfo_t));
4061	if (!context) { LogMsg("ERROR: hndlTruncatedAnswer - memallocate failed"); return; }
4062	ubzero(context, sizeof(tcpInfo_t));
4063	context->question = question;
4064	context->m = m;
4065	info->id = newMessageID(&m->uDNS_info);
4066
4067	connectionStatus = mDNSPlatformTCPConnect(src, UnicastDNSPort, question->InterfaceID, conQueryCallback, context, &sd);
4068	if (connectionStatus == mStatus_ConnEstablished)  // manually invoke callback if connection completes
4069		{
4070		conQueryCallback(sd, context, mDNStrue);
4071		return;
4072		}
4073	if (connectionStatus == mStatus_ConnPending) return; // callback will be automatically invoked when connection completes
4074	LogMsg("hndlTruncatedAnswer: connection failed");
4075	uDNS_StopQuery(m, question);  //!!!KRS can we really call this here?
4076	}
4077
4078
4079// ***************************************************************************
4080#if COMPILER_LIKES_PRAGMA_MARK
4081#pragma mark - Dynamic Updates
4082#endif
4083
4084mDNSlocal void sendRecordRegistration(mDNS *const m, AuthRecord *rr)
4085	{
4086	DNSMessage msg;
4087	mDNSu8 *ptr = msg.data;
4088	mDNSu8 *end = (mDNSu8 *)&msg + sizeof(DNSMessage);
4089	uDNS_GlobalInfo *u = &m->uDNS_info;
4090	mDNSOpaque16 id;
4091	uDNS_RegInfo *regInfo = &rr->uDNS_info;
4092	mStatus err = mStatus_UnknownErr;
4093
4094	id = newMessageID(u);
4095	InitializeDNSMessage(&msg.h, id, UpdateReqFlags);
4096	rr->uDNS_info.id = id;
4097
4098    // set zone
4099	ptr = putZone(&msg, ptr, end, &regInfo->zone, mDNSOpaque16fromIntVal(rr->resrec.rrclass));
4100	if (!ptr) goto error;
4101
4102	if (regInfo->state == regState_UpdatePending)
4103		{
4104		// delete old RData
4105		SetNewRData(&rr->resrec, regInfo->OrigRData, regInfo->OrigRDLen);
4106		if (!(ptr = putDeletionRecord(&msg, ptr, &rr->resrec))) goto error;  // delete old rdata
4107
4108		// add new RData
4109		SetNewRData(&rr->resrec, regInfo->InFlightRData, regInfo->InFlightRDLen);
4110		if (!(ptr = PutResourceRecordTTLJumbo(&msg, ptr, &msg.h.mDNS_numUpdates, &rr->resrec, rr->resrec.rroriginalttl))) goto error;
4111		}
4112
4113	else
4114		{
4115		if (rr->resrec.RecordType == kDNSRecordTypeKnownUnique)
4116			{
4117			// KnownUnique: Delete any previous value
4118			ptr = putDeleteRRSet(&msg, ptr, rr->resrec.name, rr->resrec.rrtype);
4119			if (!ptr) goto error;
4120			}
4121
4122		else if (rr->resrec.RecordType != kDNSRecordTypeShared)
4123			{
4124			ptr = putPrereqNameNotInUse(rr->resrec.name, &msg, ptr, end);
4125			if (!ptr) goto error;
4126			}
4127
4128		ptr = PutResourceRecordTTLJumbo(&msg, ptr, &msg.h.mDNS_numUpdates, &rr->resrec, rr->resrec.rroriginalttl);
4129		if (!ptr) goto error;
4130		}
4131
4132	if (rr->uDNS_info.lease)
4133		{ ptr = putUpdateLease(&msg, ptr, DEFAULT_UPDATE_LEASE); if (!ptr) goto error; }
4134
4135	err = mDNSSendDNSMessage(m, &msg, ptr, mDNSInterface_Any, &regInfo->ns, regInfo->port, -1, GetAuthInfoForName(u, rr->resrec.name));
4136	if (err) debugf("ERROR: sendRecordRegistration - mDNSSendDNSMessage - %ld", err);
4137
4138	SetRecordRetry(m, rr, err);
4139
4140	if (regInfo->state != regState_Refresh && regInfo->state != regState_DeregDeferred && regInfo->state != regState_UpdatePending)
4141		regInfo->state = regState_Pending;
4142
4143	return;
4144
4145error:
4146	LogMsg("sendRecordRegistration: Error formatting message");
4147	if (rr->uDNS_info.state != regState_Unregistered)
4148		{
4149		unlinkAR(&u->RecordRegistrations, rr);
4150		rr->uDNS_info.state = regState_Unregistered;
4151		}
4152	m->mDNS_reentrancy++; // Increment to allow client to legally make mDNS API calls from the callback
4153	if (rr->RecordCallback) rr->RecordCallback(m, rr, err);
4154	m->mDNS_reentrancy--; // Decrement to block mDNS API calls again
4155	// NOTE: not safe to touch any client structures here
4156	}
4157
4158mDNSlocal void RecordRegistrationCallback(mStatus err, mDNS *const m, void *authPtr, const AsyncOpResult *result)
4159	{
4160	AuthRecord *newRR = (AuthRecord*)authPtr;
4161	const zoneData_t *zoneData = mDNSNULL;
4162	uDNS_GlobalInfo *u = &m->uDNS_info;
4163	AuthRecord *ptr;
4164
4165	// make sure record is still in list
4166	for (ptr = u->RecordRegistrations; ptr; ptr = ptr->next)
4167		if (ptr == newRR) break;
4168	if (!ptr) { LogMsg("RecordRegistrationCallback - RR no longer in list.  Discarding."); return; }
4169
4170	// check error/result
4171	if (err) { LogMsg("RecordRegistrationCallback: error %ld", err); goto error; }
4172	if (!result) { LogMsg("ERROR: RecordRegistrationCallback invoked with NULL result and no error"); goto error;  }
4173	else zoneData = &result->zoneData;
4174
4175	if (newRR->uDNS_info.state == regState_Cancelled)
4176		{
4177		//!!!KRS we should send a memfree callback here!
4178		debugf("Registration of %##s type %d cancelled prior to update",
4179			   newRR->resrec.name->c, newRR->resrec.rrtype);
4180		newRR->uDNS_info.state = regState_Unregistered;
4181		unlinkAR(&u->RecordRegistrations, newRR);
4182		return;
4183		}
4184
4185	if (result->type != zoneDataResult)
4186		{
4187		LogMsg("ERROR: buildUpdatePacket passed incorrect result type %d", result->type);
4188		goto error;
4189		}
4190
4191	if (newRR->resrec.rrclass != zoneData->zoneClass)
4192		{
4193		LogMsg("ERROR: New resource record's class (%d) does not match zone class (%d)",
4194			   newRR->resrec.rrclass, zoneData->zoneClass);
4195		goto error;
4196		}
4197
4198	// Don't try to do updates to the root name server.
4199	// We might be tempted also to block updates to any single-label name server (e.g. com, edu, net, etc.) but some
4200	// organizations use their own private pseudo-TLD, like ".home", etc, and we don't want to block that.
4201	if (zoneData->zoneName.c[0] == 0)
4202		{
4203		LogMsg("ERROR: Only name server claiming responsibility for \"%##s\" is \"%##s\"!",
4204			newRR->resrec.name->c, zoneData->zoneName.c);
4205		err = mStatus_NoSuchNameErr;
4206		goto error;
4207		}
4208
4209	// cache zone data
4210	AssignDomainName(&newRR->uDNS_info.zone, &zoneData->zoneName);
4211	newRR->uDNS_info.ns = zoneData->primaryAddr;
4212	if (zoneData->updatePort.NotAnInteger) newRR->uDNS_info.port = zoneData->updatePort;
4213	else
4214		{
4215		debugf("Update port not advertised via SRV - guessing port 53, no lease option");
4216		newRR->uDNS_info.port = UnicastDNSPort;
4217		newRR->uDNS_info.lease = mDNSfalse;
4218		}
4219
4220	sendRecordRegistration(m, newRR);
4221	return;
4222
4223error:
4224	if (newRR->uDNS_info.state != regState_Unregistered)
4225		{
4226		unlinkAR(&u->RecordRegistrations, newRR);
4227		newRR->uDNS_info.state = regState_Unregistered;
4228		}
4229	m->mDNS_reentrancy++; // Increment to allow client to legally make mDNS API calls from the callback
4230	if (newRR->RecordCallback)
4231		newRR->RecordCallback(m, newRR, err);
4232	m->mDNS_reentrancy--; // Decrement to block mDNS API calls again
4233	// NOTE: not safe to touch any client structures here
4234	}
4235
4236mDNSlocal void SendServiceRegistration(mDNS *m, ServiceRecordSet *srs)
4237	{
4238	DNSMessage msg;
4239	mDNSu8 *ptr = msg.data;
4240	mDNSu8 *end = (mDNSu8 *)&msg + sizeof(DNSMessage);
4241	uDNS_GlobalInfo *u = &m->uDNS_info;
4242	mDNSOpaque16 id;
4243	uDNS_RegInfo *rInfo = &srs->uDNS_info;
4244	mStatus err = mStatus_UnknownErr;
4245	mDNSIPPort privport;
4246	NATTraversalInfo *nat = srs->uDNS_info.NATinfo;
4247	mDNSBool mapped = mDNSfalse;
4248	domainname target;
4249	AuthRecord *srv = &srs->RR_SRV;
4250	mDNSu32 i;
4251
4252	privport = zeroIPPort;
4253
4254	if (!rInfo->ns.ip.v4.NotAnInteger) { LogMsg("SendServiceRegistration - NS not set!"); return; }
4255
4256	id = newMessageID(u);
4257	InitializeDNSMessage(&msg.h, id, UpdateReqFlags);
4258
4259	// setup resource records
4260	SetNewRData(&srs->RR_PTR.resrec, mDNSNULL, 0);
4261	SetNewRData(&srs->RR_TXT.resrec, mDNSNULL, 0);
4262
4263	// replace port w/ NAT mapping if necessary
4264 	if (nat && nat->PublicPort.NotAnInteger &&
4265		(nat->state == NATState_Established || nat->state == NATState_Refresh || nat->state == NATState_Legacy))
4266		{
4267		privport = srv->resrec.rdata->u.srv.port;
4268		srv->resrec.rdata->u.srv.port = nat->PublicPort;
4269		mapped = mDNStrue;
4270		}
4271
4272	// construct update packet
4273    // set zone
4274	ptr = putZone(&msg, ptr, end, &rInfo->zone, mDNSOpaque16fromIntVal(srv->resrec.rrclass));
4275	if (!ptr) goto error;
4276
4277	if (srs->uDNS_info.TestForSelfConflict)
4278		{
4279		// update w/ prereq that SRV already exist to make sure previous registration was ours, and delete any stale TXT records
4280		if (!(ptr = PutResourceRecordTTLJumbo(&msg, ptr, &msg.h.mDNS_numPrereqs, &srs->RR_SRV.resrec, 0))) goto error;
4281		if (!(ptr = putDeleteRRSet(&msg, ptr, srs->RR_TXT.resrec.name, srs->RR_TXT.resrec.rrtype)))       goto error;
4282		}
4283
4284	else if (srs->uDNS_info.state != regState_Refresh && srs->uDNS_info.state != regState_UpdatePending)
4285		{
4286		// use SRV name for prereq
4287		ptr = putPrereqNameNotInUse(srv->resrec.name, &msg, ptr, end);
4288		if (!ptr) goto error;
4289		}
4290
4291	//!!!KRS  Need to do bounds checking and use TCP if it won't fit!!!
4292	if (!(ptr = PutResourceRecordTTLJumbo(&msg, ptr, &msg.h.mDNS_numUpdates, &srs->RR_PTR.resrec, srs->RR_PTR.resrec.rroriginalttl))) goto error;
4293
4294	for (i = 0; i < srs->NumSubTypes; i++)
4295		if (!(ptr = PutResourceRecordTTLJumbo(&msg, ptr, &msg.h.mDNS_numUpdates, &srs->SubTypes[i].resrec, srs->SubTypes[i].resrec.rroriginalttl))) goto error;
4296
4297	if (rInfo->state == regState_UpdatePending) // we're updating the txt record
4298		{
4299		AuthRecord *txt = &srs->RR_TXT;
4300		uDNS_RegInfo *txtInfo = &txt->uDNS_info;
4301		// delete old RData
4302		SetNewRData(&txt->resrec, txtInfo->OrigRData, txtInfo->OrigRDLen);
4303		if (!(ptr = putDeletionRecord(&msg, ptr, &srs->RR_TXT.resrec))) goto error;  // delete old rdata
4304
4305		// add new RData
4306		SetNewRData(&txt->resrec, txtInfo->InFlightRData, txtInfo->InFlightRDLen);
4307		if (!(ptr = PutResourceRecordTTLJumbo(&msg, ptr, &msg.h.mDNS_numUpdates, &srs->RR_TXT.resrec, srs->RR_TXT.resrec.rroriginalttl))) goto error;
4308		}
4309	else
4310		if (!(ptr = PutResourceRecordTTLJumbo(&msg, ptr, &msg.h.mDNS_numUpdates, &srs->RR_TXT.resrec, srs->RR_TXT.resrec.rroriginalttl))) goto error;
4311
4312	 if (!GetServiceTarget(u, srv, &target))
4313		{
4314		debugf("Couldn't get target for service %##s", srv->resrec.name->c);
4315		rInfo->state = regState_NoTarget;
4316		return;
4317		}
4318
4319	 if (!SameDomainName(&target, &srv->resrec.rdata->u.srv.target))
4320		 {
4321		 AssignDomainName(&srv->resrec.rdata->u.srv.target, &target);
4322		 SetNewRData(&srv->resrec, mDNSNULL, 0);
4323		 }
4324
4325	ptr = PutResourceRecordTTLJumbo(&msg, ptr, &msg.h.mDNS_numUpdates, &srv->resrec, srv->resrec.rroriginalttl);
4326	if (!ptr) goto error;
4327
4328	if (srs->uDNS_info.lease)
4329		{ ptr = putUpdateLease(&msg, ptr, DEFAULT_UPDATE_LEASE); if (!ptr) goto error; }
4330
4331	err = mDNSSendDNSMessage(m, &msg, ptr, mDNSInterface_Any, &rInfo->ns, rInfo->port, -1, GetAuthInfoForName(u, srs->RR_SRV.resrec.name));
4332	if (err) debugf("ERROR: SendServiceRegistration - mDNSSendDNSMessage - %ld", err);
4333
4334	if (rInfo->state != regState_Refresh && rInfo->state != regState_DeregDeferred && srs->uDNS_info.state != regState_UpdatePending)
4335		rInfo->state = regState_Pending;
4336
4337	SetRecordRetry(m, &srs->RR_SRV, err);
4338	rInfo->id = id;
4339	if (mapped) srv->resrec.rdata->u.srv.port = privport;
4340	return;
4341
4342error:
4343	LogMsg("SendServiceRegistration - Error formatting message");
4344	if (mapped) srv->resrec.rdata->u.srv.port = privport;
4345	unlinkSRS(m, srs);
4346	rInfo->state = regState_Unregistered;
4347	m->mDNS_reentrancy++; // Increment to allow client to legally make mDNS API calls from the callback
4348	srs->ServiceCallback(m, srs, err);
4349	m->mDNS_reentrancy--; // Decrement to block mDNS API calls again
4350	//!!!KRS will mem still be free'd on error?
4351	// NOTE: not safe to touch any client structures here
4352	}
4353
4354mDNSlocal void serviceRegistrationCallback(mStatus err, mDNS *const m, void *srsPtr, const AsyncOpResult *result)
4355	{
4356	ServiceRecordSet *srs = (ServiceRecordSet *)srsPtr;
4357	const zoneData_t *zoneData = mDNSNULL;
4358
4359	if (err) goto error;
4360	if (!result) { LogMsg("ERROR: serviceRegistrationCallback invoked with NULL result and no error");  goto error; }
4361	else zoneData = &result->zoneData;
4362
4363	if (result->type != zoneDataResult)
4364		{
4365		LogMsg("ERROR: buildUpdatePacket passed incorrect result type %d", result->type);
4366		goto error;
4367		}
4368
4369	if (srs->uDNS_info.state == regState_Cancelled)
4370		{
4371		// client cancelled registration while fetching zone data
4372		srs->uDNS_info.state = regState_Unregistered;
4373		unlinkSRS(m, srs);
4374		m->mDNS_reentrancy++; // Increment to allow client to legally make mDNS API calls from the callback
4375		srs->ServiceCallback(m, srs, mStatus_MemFree);
4376		m->mDNS_reentrancy--; // Decrement to block mDNS API calls again
4377		return;
4378		}
4379
4380	if (srs->RR_SRV.resrec.rrclass != zoneData->zoneClass)
4381		{
4382		LogMsg("Service %##s - class does not match zone", srs->RR_SRV.resrec.name->c);
4383		goto error;
4384		}
4385
4386	// cache zone data
4387	AssignDomainName(&srs->uDNS_info.zone, &zoneData->zoneName);
4388    srs->uDNS_info.ns.type = mDNSAddrType_IPv4;
4389	srs->uDNS_info.ns = zoneData->primaryAddr;
4390	if (zoneData->updatePort.NotAnInteger) srs->uDNS_info.port = zoneData->updatePort;
4391	else
4392		{
4393		debugf("Update port not advertised via SRV - guessing port 53, no lease option");
4394		srs->uDNS_info.port = UnicastDNSPort;
4395		srs->uDNS_info.lease = mDNSfalse;
4396		}
4397
4398	if (srs->RR_SRV.resrec.rdata->u.srv.port.NotAnInteger && IsPrivateV4Addr(&m->uDNS_info.AdvertisedV4))
4399		{ srs->uDNS_info.state = regState_NATMap; StartNATPortMap(m, srs); }
4400	else SendServiceRegistration(m, srs);
4401	return;
4402
4403error:
4404	unlinkSRS(m, srs);
4405	srs->uDNS_info.state = regState_Unregistered;
4406	m->mDNS_reentrancy++; // Increment to allow client to legally make mDNS API calls from the callback
4407	srs->ServiceCallback(m, srs, err);
4408	m->mDNS_reentrancy--; // Decrement to block mDNS API calls again
4409	// NOTE: not safe to touch any client structures here
4410	}
4411
4412mDNSlocal mStatus SetupRecordRegistration(mDNS *m, AuthRecord *rr)
4413	{
4414	domainname *target = GetRRDomainNameTarget(&rr->resrec);
4415	AuthRecord *ptr = m->uDNS_info.RecordRegistrations;
4416
4417	while (ptr && ptr != rr) ptr = ptr->next;
4418	if (ptr) { LogMsg("Error: SetupRecordRegistration - record %##s already in list!", rr->resrec.name->c); return mStatus_AlreadyRegistered; }
4419
4420	if (rr->uDNS_info.state == regState_FetchingZoneData ||
4421		rr->uDNS_info.state == regState_Pending ||
4422		rr->uDNS_info.state ==  regState_Registered)
4423		{
4424		LogMsg("Requested double-registration of physical record %##s type %d",
4425			   rr->resrec.name->c, rr->resrec.rrtype);
4426		return mStatus_AlreadyRegistered;
4427		}
4428
4429	rr->resrec.rdlength   = GetRDLength(&rr->resrec, mDNSfalse);
4430	rr->resrec.rdestimate = GetRDLength(&rr->resrec, mDNStrue);
4431
4432	if (!ValidateDomainName(rr->resrec.name))
4433		{
4434		LogMsg("Attempt to register record with invalid name: %s", ARDisplayString(m, rr));
4435		return mStatus_Invalid;
4436		}
4437
4438	// Don't do this until *after* we've set rr->resrec.rdlength
4439	if (!ValidateRData(rr->resrec.rrtype, rr->resrec.rdlength, rr->resrec.rdata))
4440		{
4441		LogMsg("Attempt to register record with invalid rdata: %s", ARDisplayString(m, rr));
4442		return mStatus_Invalid;
4443		}
4444
4445	rr->resrec.namehash   = DomainNameHashValue(rr->resrec.name);
4446	rr->resrec.rdatahash  = target ? DomainNameHashValue(target) : RDataHashValue(rr->resrec.rdlength, &rr->resrec.rdata->u);
4447
4448	rr->uDNS_info.state = regState_FetchingZoneData;
4449	rr->next = m->uDNS_info.RecordRegistrations;
4450	m->uDNS_info.RecordRegistrations = rr;
4451	rr->uDNS_info.lease = mDNStrue;
4452
4453	return mStatus_NoError;
4454	}
4455
4456mDNSexport mStatus uDNS_RegisterRecord(mDNS *const m, AuthRecord *const rr)
4457	{
4458	mStatus err = SetupRecordRegistration(m, rr);
4459	if (err) return err;
4460	else return startGetZoneData(rr->resrec.name, m, mDNStrue, mDNSfalse, RecordRegistrationCallback, rr);
4461	}
4462
4463mDNSlocal void SendRecordDeregistration(mDNS *m, AuthRecord *rr)
4464	{
4465	uDNS_GlobalInfo *u = &m->uDNS_info;
4466	DNSMessage msg;
4467	mDNSu8 *ptr = msg.data;
4468	mDNSu8 *end = (mDNSu8 *)&msg + sizeof(DNSMessage);
4469	mStatus err;
4470
4471	InitializeDNSMessage(&msg.h, rr->uDNS_info.id, UpdateReqFlags);
4472
4473	ptr = putZone(&msg, ptr, end, &rr->uDNS_info.zone, mDNSOpaque16fromIntVal(rr->resrec.rrclass));
4474	if (!ptr) goto error;
4475	if (!(ptr = putDeletionRecord(&msg, ptr, &rr->resrec))) goto error;
4476
4477	err = mDNSSendDNSMessage(m, &msg, ptr, mDNSInterface_Any, &rr->uDNS_info.ns, rr->uDNS_info.port, -1, GetAuthInfoForName(u, rr->resrec.name));
4478	if (err) debugf("ERROR: SendRecordDeregistration - mDNSSendDNSMessage - %ld", err);
4479
4480	SetRecordRetry(m, rr, err);
4481	rr->uDNS_info.state = regState_DeregPending;
4482	return;
4483
4484	error:
4485	LogMsg("Error: SendRecordDeregistration - could not contruct deregistration packet");
4486	unlinkAR(&u->RecordRegistrations, rr);
4487	rr->uDNS_info.state = regState_Unregistered;
4488	}
4489
4490
4491
4492mDNSexport mStatus uDNS_DeregisterRecord(mDNS *const m, AuthRecord *const rr)
4493	{
4494	uDNS_GlobalInfo *u = &m->uDNS_info;
4495	NATTraversalInfo *n = rr->uDNS_info.NATinfo;
4496
4497	switch (rr->uDNS_info.state)
4498		{
4499		case regState_NATMap:
4500            // we're in the middle of a NAT traversal operation
4501            rr->uDNS_info.NATinfo = mDNSNULL;
4502			if (!n) LogMsg("uDNS_DeregisterRecord: no NAT info context");
4503			else FreeNATInfo(m, n); // cause response to outstanding request to be ignored.
4504			                        // Note: normally here we're trying to determine our public address,
4505			                        //in which case there is not state to be torn down.  For simplicity,
4506			                        //we allow other operations to expire.
4507			rr->uDNS_info.state = regState_Unregistered;
4508			break;
4509		case regState_ExtraQueued:
4510			rr->uDNS_info.state = regState_Unregistered;
4511			break;
4512		case regState_FetchingZoneData:
4513			rr->uDNS_info.state = regState_Cancelled;
4514			return mStatus_NoError;
4515		case regState_Refresh:
4516		case regState_Pending:
4517		case regState_UpdatePending:
4518			rr->uDNS_info.state = regState_DeregDeferred;
4519			LogMsg("Deferring deregistration of record %##s until registration completes", rr->resrec.name->c);
4520			return mStatus_NoError;
4521		case regState_Registered:
4522		case regState_DeregPending:
4523			break;
4524		case regState_DeregDeferred:
4525		case regState_Cancelled:
4526			LogMsg("Double deregistration of record %##s type %d",
4527				   rr->resrec.name->c, rr->resrec.rrtype);
4528			return mStatus_UnknownErr;
4529		case regState_Unregistered:
4530			LogMsg("Requested deregistration of unregistered record %##s type %d",
4531				   rr->resrec.name->c, rr->resrec.rrtype);
4532			return mStatus_UnknownErr;
4533		case regState_NATError:
4534		case  regState_NoTarget:
4535			LogMsg("ERROR: uDNS_DeregisterRecord called for record %##s with bad state %s", rr->resrec.name->c, rr->uDNS_info.state == regState_NoTarget ? "regState_NoTarget" : "regState_NATError");
4536			return mStatus_UnknownErr;
4537		}
4538
4539	if (rr->uDNS_info.state == regState_Unregistered)
4540		{
4541		// unlink and deliver memfree
4542
4543		unlinkAR(&u->RecordRegistrations, rr);
4544		m->mDNS_reentrancy++; // Increment to allow client to legally make mDNS API calls from the callback
4545		if (rr->RecordCallback) rr->RecordCallback(m, rr, mStatus_MemFree);
4546		m->mDNS_reentrancy--; // Decrement to block mDNS API calls again
4547		return mStatus_NoError;
4548		}
4549
4550	rr->uDNS_info.NATinfo = mDNSNULL;
4551	if (n) FreeNATInfo(m, n);
4552
4553	SendRecordDeregistration(m, rr);
4554	return mStatus_NoError;
4555	}
4556
4557mDNSexport mStatus uDNS_RegisterService(mDNS *const m, ServiceRecordSet *srs)
4558	{
4559	mDNSu32 i;
4560	domainname target;
4561	uDNS_RegInfo *info = &srs->uDNS_info;
4562	ServiceRecordSet **p = &m->uDNS_info.ServiceRegistrations;
4563	while (*p && *p != srs) p=&(*p)->next;
4564	if (*p) { LogMsg("uDNS_RegisterService: %p %##s already in list", srs, srs->RR_SRV.resrec.name->c); return(mStatus_AlreadyRegistered); }
4565	ubzero(info, sizeof(*info));
4566	*p = srs;
4567	srs->next = mDNSNULL;
4568
4569	srs->RR_SRV.resrec.rroriginalttl = kWideAreaTTL;
4570	srs->RR_TXT.resrec.rroriginalttl = kWideAreaTTL;
4571	srs->RR_PTR.resrec.rroriginalttl = kWideAreaTTL;
4572	for (i = 0; i < srs->NumSubTypes;i++) srs->SubTypes[i].resrec.rroriginalttl = kWideAreaTTL;
4573
4574	info->lease = mDNStrue;
4575
4576	srs->RR_SRV.resrec.rdata->u.srv.target.c[0] = 0;
4577	if (!GetServiceTarget(&m->uDNS_info, &srs->RR_SRV, &target))
4578		{
4579		// defer registration until we've got a target
4580		debugf("uDNS_RegisterService - no target for %##s", srs->RR_SRV.resrec.name->c);
4581		info->state = regState_NoTarget;
4582		return mStatus_NoError;
4583		}
4584
4585	info->state = regState_FetchingZoneData;
4586	return startGetZoneData(srs->RR_SRV.resrec.name, m, mDNStrue, mDNSfalse, serviceRegistrationCallback, srs);
4587	}
4588
4589mDNSlocal void SendServiceDeregistration(mDNS *m, ServiceRecordSet *srs)
4590	{
4591	uDNS_RegInfo *info = &srs->uDNS_info;
4592	uDNS_GlobalInfo *u = &m->uDNS_info;
4593	DNSMessage msg;
4594	mDNSOpaque16 id;
4595	mDNSu8 *ptr = msg.data;
4596	mDNSu8 *end = (mDNSu8 *)&msg + sizeof(DNSMessage);
4597	mStatus err = mStatus_UnknownErr;
4598	mDNSu32 i;
4599
4600	id = newMessageID(u);
4601	InitializeDNSMessage(&msg.h, id, UpdateReqFlags);
4602
4603    // put zone
4604	ptr = putZone(&msg, ptr, end, &info->zone, mDNSOpaque16fromIntVal(srs->RR_SRV.resrec.rrclass));
4605	if (!ptr) { LogMsg("ERROR: SendServiceDeregistration - putZone"); goto error; }
4606
4607	if (!(ptr = putDeleteAllRRSets(&msg, ptr, srs->RR_SRV.resrec.name))) goto error;  // this deletes SRV, TXT, and Extras
4608	if (!(ptr = putDeletionRecord(&msg, ptr, &srs->RR_PTR.resrec))) goto error;
4609	for (i = 0; i < srs->NumSubTypes; i++)
4610		if (!(ptr = putDeletionRecord(&msg, ptr, &srs->SubTypes[i].resrec))) goto error;
4611
4612
4613	err = mDNSSendDNSMessage(m, &msg, ptr, mDNSInterface_Any, &info->ns, info->port, -1, GetAuthInfoForName(u, srs->RR_SRV.resrec.name));
4614	if (err && err != mStatus_TransientErr) { debugf("ERROR: SendServiceDeregistration - mDNSSendDNSMessage - %ld", err); goto error; }
4615
4616	SetRecordRetry(m, &srs->RR_SRV, err);
4617    info->id = id;
4618	info->state = regState_DeregPending;
4619
4620	return;
4621
4622	error:
4623	unlinkSRS(m, srs);
4624	info->state = regState_Unregistered;
4625	}
4626
4627mDNSexport mStatus uDNS_DeregisterService(mDNS *const m, ServiceRecordSet *srs)
4628	{
4629	NATTraversalInfo *nat = srs->uDNS_info.NATinfo;
4630	char *errmsg = "Unknown State";
4631
4632	// don't re-register with a new target following deregistration
4633	srs->uDNS_info.SRVChanged = srs->uDNS_info.SRVUpdateDeferred = mDNSfalse;
4634
4635	if (nat)
4636		{
4637		if (nat->state == NATState_Established || nat->state == NATState_Refresh || nat->state == NATState_Legacy)
4638			DeleteNATPortMapping(m, nat, srs);
4639		nat->reg.ServiceRegistration = mDNSNULL;
4640		srs->uDNS_info.NATinfo = mDNSNULL;
4641		FreeNATInfo(m, nat);
4642		}
4643
4644	switch (srs->uDNS_info.state)
4645		{
4646		case regState_Unregistered:
4647			debugf("uDNS_DeregisterService - service %##s not registered", srs->RR_SRV.resrec.name->c);
4648			return mStatus_BadReferenceErr;
4649		case regState_FetchingZoneData:
4650			// let the async op complete, then terminate
4651			srs->uDNS_info.state = regState_Cancelled;
4652			return mStatus_NoError;  // deliver memfree upon completion of async op
4653		case regState_Pending:
4654		case regState_Refresh:
4655		case regState_UpdatePending:
4656			// deregister following completion of in-flight operation
4657			srs->uDNS_info.state = regState_DeregDeferred;
4658			return mStatus_NoError;
4659		case regState_DeregPending:
4660		case regState_DeregDeferred:
4661		case regState_Cancelled:
4662			debugf("Double deregistration of service %##s", srs->RR_SRV.resrec.name->c);
4663			return mStatus_NoError;
4664		case regState_NATError:  // not registered
4665		case regState_NATMap:    // not registered
4666		case regState_NoTarget:  // not registered
4667			unlinkSRS(m, srs);
4668			srs->uDNS_info.state = regState_Unregistered;
4669			m->mDNS_reentrancy++; // Increment to allow client to legally make mDNS API calls from the callback
4670			srs->ServiceCallback(m, srs, mStatus_MemFree);
4671			m->mDNS_reentrancy--; // Decrement to block mDNS API calls again
4672			return mStatus_NoError;
4673		case regState_Registered:
4674			srs->uDNS_info.state = regState_DeregPending;
4675			SendServiceDeregistration(m, srs);
4676			return mStatus_NoError;
4677		case regState_ExtraQueued: // only for record registrations
4678			errmsg = "bad state (regState_ExtraQueued)";
4679			goto error;
4680		}
4681
4682	error:
4683	LogMsg("Error, uDNS_DeregisterService: %s", errmsg);
4684	return mStatus_BadReferenceErr;
4685	}
4686
4687mDNSexport mStatus uDNS_AddRecordToService(mDNS *const m, ServiceRecordSet *sr, ExtraResourceRecord *extra)
4688	{
4689	mStatus err = mStatus_UnknownErr;
4690
4691	extra->r.resrec.RecordType = kDNSRecordTypeShared;  // don't want it to conflict with the service name
4692	extra->r.RecordCallback = mDNSNULL;  // don't generate callbacks for extra RRs
4693
4694	if (sr->uDNS_info.state == regState_Registered || sr->uDNS_info.state == regState_Refresh)
4695		err = uDNS_RegisterRecord(m, &extra->r);
4696	else
4697		{
4698		err = SetupRecordRegistration(m, &extra->r);
4699		extra->r.uDNS_info.state = regState_ExtraQueued; // %%% Is it okay to overwrite the previous uDNS_info.state?
4700		}
4701
4702	if (!err)
4703		{
4704		extra->next = sr->Extras;
4705		sr->Extras = extra;
4706		}
4707	return err;
4708	}
4709
4710mDNSexport mStatus uDNS_UpdateRecord(mDNS *m, AuthRecord *rr)
4711	{
4712	uDNS_GlobalInfo *u = &m->uDNS_info;
4713	ServiceRecordSet *parent = mDNSNULL;
4714	AuthRecord *rptr;
4715	uDNS_RegInfo *info = &rr->uDNS_info;
4716	regState_t *stateptr = mDNSNULL;
4717
4718	// find the record in registered service list
4719	for (parent = u->ServiceRegistrations; parent; parent = parent->next)
4720		if (&parent->RR_TXT == rr) { stateptr = &parent->uDNS_info.state; break; }
4721
4722	if (!parent)
4723		{
4724		// record not part of a service - check individual record registrations
4725		for (rptr = u->RecordRegistrations; rptr; rptr = rptr->next)
4726			if (rptr == rr) { stateptr = &rr->uDNS_info.state; break; }
4727		if (!rptr) goto unreg_error;
4728		}
4729
4730	switch(*stateptr)
4731		{
4732		case regState_DeregPending:
4733		case regState_DeregDeferred:
4734		case regState_Cancelled:
4735		case regState_Unregistered:
4736			// not actively registered
4737			goto unreg_error;
4738
4739		case regState_FetchingZoneData:
4740		case regState_NATMap:
4741		case regState_ExtraQueued:
4742		case regState_NoTarget:
4743			// change rdata directly since it hasn't been sent yet
4744			if (info->UpdateRDCallback) info->UpdateRDCallback(m, rr, rr->resrec.rdata);
4745			SetNewRData(&rr->resrec, rr->NewRData, rr->newrdlength);
4746			rr->NewRData = mDNSNULL;
4747			return mStatus_NoError;
4748
4749		case regState_Pending:
4750		case regState_Refresh:
4751		case regState_UpdatePending:
4752			// registration in-flight.  queue rdata and return
4753			if (info->QueuedRData && info->UpdateRDCallback)
4754				// if unsent rdata is already queued, free it before we replace it
4755				info->UpdateRDCallback(m, rr, info->QueuedRData);
4756			info->QueuedRData = rr->NewRData;
4757			info->QueuedRDLen = rr->newrdlength;
4758			rr->NewRData = mDNSNULL;
4759			return mStatus_NoError;
4760
4761		case regState_Registered:
4762			info->OrigRData = rr->resrec.rdata;
4763			info->OrigRDLen = rr->resrec.rdlength;
4764			info->InFlightRData = rr->NewRData;
4765			info->InFlightRDLen = rr->newrdlength;
4766			rr->NewRData = mDNSNULL;
4767			*stateptr = regState_UpdatePending;
4768			if (parent)  SendServiceRegistration(m, parent);
4769			else sendRecordRegistration(m, rr);
4770			return mStatus_NoError;
4771
4772		case regState_NATError:
4773			LogMsg("ERROR: uDNS_UpdateRecord called for record %##s with bad state regState_NATError", rr->resrec.name->c);
4774			return mStatus_UnknownErr;  // states for service records only
4775		}
4776
4777	unreg_error:
4778	LogMsg("Requested update of record %##s type %d, part of service not currently registered",
4779		   rr->resrec.name->c, rr->resrec.rrtype);
4780	return mStatus_Invalid;
4781	}
4782
4783
4784// ***************************************************************************
4785#if COMPILER_LIKES_PRAGMA_MARK
4786#pragma mark - Periodic Execution Routines
4787#endif
4788
4789
4790mDNSlocal mDNSs32 CheckNATMappings(mDNS *m, mDNSs32 timenow)
4791	{
4792	NATTraversalInfo *ptr = m->uDNS_info.NATTraversals;
4793	mDNSs32 nextevent = timenow + MIN_UCAST_PERIODIC_EXEC;
4794
4795	while (ptr)
4796		{
4797		NATTraversalInfo *cur = ptr;
4798		ptr = ptr->next;
4799		if (cur->op != NATOp_AddrRequest || cur->state != NATState_Established)  // no refresh necessary for established Add requests
4800			{
4801			if (cur->retry - timenow < 0)
4802				{
4803				if (cur->state == NATState_Established) RefreshNATMapping(cur, m);
4804				else if (cur->state == NATState_Request || cur->state == NATState_Refresh)
4805					{
4806					if (cur->ntries >= NATMAP_MAX_TRIES) cur->ReceiveResponse(cur, m, mDNSNULL, 0); // may invalidate "cur"
4807					else SendNATMsg(cur, m);
4808					}
4809				}
4810			else if (cur->retry - nextevent < 0) nextevent = cur->retry;
4811			}
4812		}
4813	return nextevent;
4814	}
4815
4816mDNSlocal mDNSs32 CheckQueries(mDNS *m, mDNSs32 timenow)
4817	{
4818	DNSQuestion *q;
4819	uDNS_GlobalInfo *u = &m->uDNS_info;
4820	LLQ_Info *llq;
4821	mDNSs32 sendtime;
4822	mDNSs32 nextevent = timenow + MIN_UCAST_PERIODIC_EXEC;
4823	DNSMessage msg;
4824	mStatus err = mStatus_NoError;
4825	mDNSu8 *end;
4826	uDNS_QuestionInfo *info;
4827
4828	u->CurrentQuery = u->ActiveQueries;
4829	while (u->CurrentQuery)
4830		{
4831		q = u->CurrentQuery;
4832		info = &q->uDNS_info;
4833		llq = info->llq;
4834
4835		if (!info->internal && ((!q->LongLived && !info->Answered) || (llq && llq->state < LLQ_Established)) &&
4836			info->RestartTime + RESTART_GOODBYE_DELAY - timenow < 0)
4837			{
4838			// if we've been spinning on restart setup, and we have known answers, give goodbyes (they may be re-added later)
4839			while (info->knownAnswers)
4840				{
4841				CacheRecord *cr = info->knownAnswers;
4842				info->knownAnswers = info->knownAnswers->next;
4843
4844				m->mDNS_reentrancy++; // Increment to allow client to legally make mDNS API calls from the callback
4845				q->QuestionCallback(m, q, &cr->resrec, mDNSfalse);
4846				m->mDNS_reentrancy--; // Decrement to block mDNS API calls again
4847				ufree(cr);
4848				if (q != u->CurrentQuery) { debugf("CheckQueries - question removed via callback."); break; }
4849				}
4850			}
4851		if (q != u->CurrentQuery) continue;
4852
4853		if (q->LongLived && llq->state != LLQ_Poll)
4854			{
4855			if (llq->state >= LLQ_InitialRequest && llq->state <= LLQ_Established)
4856				{
4857				if (llq->retry - timenow < 0)
4858					{
4859					// sanity check to avoid packet flood bugs
4860					if (!llq->retry)
4861						LogMsg("ERROR: retry timer not set for LLQ %##s in state %d", q->qname.c, llq->state);
4862					else if (llq->state == LLQ_Established || llq->state == LLQ_Refresh)
4863						sendLLQRefresh(m, q, llq->origLease);
4864					else if (llq->state == LLQ_InitialRequest)
4865						startLLQHandshake(m, llq, mDNSfalse);
4866					else if (llq->state == LLQ_SecondaryRequest)
4867						sendChallengeResponse(m, q, mDNSNULL);
4868					else if (llq->state == LLQ_Retry)
4869						{ llq->ntries = 0; startLLQHandshake(m, llq, mDNSfalse); }
4870					}
4871				else if (llq->retry - nextevent < 0) nextevent = llq->retry;
4872				}
4873			}
4874		else
4875			{
4876			sendtime = q->LastQTime + q->ThisQInterval;
4877			if (m->SuppressStdPort53Queries &&
4878				sendtime - m->SuppressStdPort53Queries < 0) // Don't allow sendtime to be earlier than SuppressStdPort53Queries
4879				sendtime = m->SuppressStdPort53Queries;
4880			if (sendtime - timenow < 0)
4881				{
4882				DNSServer *server = GetServerForName(&m->uDNS_info, &q->qname);
4883				if (server)
4884					{
4885					if (server->teststate == DNSServer_Untested)
4886						{
4887						InitializeDNSMessage(&msg.h, newMessageID(&m->uDNS_info), uQueryFlags);
4888						end = putQuestion(&msg, msg.data, msg.data + AbsoluteMaxDNSMessageData, DNSRelayTestQuestion, kDNSType_PTR, kDNSClass_IN);
4889						}
4890					else
4891						err = constructQueryMsg(&msg, &end, q);
4892					if (err)  LogMsg("Error: uDNS_Idle - constructQueryMsg.  Skipping question %##s", q->qname.c);
4893					else
4894						{
4895						if (server->teststate != DNSServer_Failed)
4896							err = mDNSSendDNSMessage(m, &msg, end, mDNSInterface_Any, &server->addr, UnicastDNSPort, -1, mDNSNULL);
4897						m->SuppressStdPort53Queries = NonZeroTime(m->timenow + (mDNSPlatformOneSecond+99)/100);
4898						q->LastQTime = timenow;
4899						if (err) debugf("ERROR: uDNS_idle - mDNSSendDNSMessage - %ld", err); // surpress syslog messages if we have no network
4900						else if (q->ThisQInterval < MAX_UCAST_POLL_INTERVAL) q->ThisQInterval = q->ThisQInterval * 2;  // don't increase interval if send failed
4901						}
4902					}
4903				}
4904			else if (sendtime - nextevent < 0) nextevent = sendtime;
4905			}
4906		u->CurrentQuery = u->CurrentQuery->next;
4907		}
4908	return nextevent;
4909	}
4910
4911mDNSlocal mDNSs32 CheckRecordRegistrations(mDNS *m, mDNSs32 timenow)
4912	{
4913	AuthRecord *rr;
4914	uDNS_RegInfo *rInfo;
4915	uDNS_GlobalInfo *u = &m->uDNS_info;
4916 	mDNSs32 nextevent = timenow + MIN_UCAST_PERIODIC_EXEC;
4917
4918	//!!!KRS list should be pre-sorted by expiration
4919	for (rr = u->RecordRegistrations; rr; rr = rr->next)
4920		{
4921		rInfo = &rr->uDNS_info;
4922		if (rInfo->state == regState_Pending || rInfo->state == regState_DeregPending || rInfo->state == regState_UpdatePending || rInfo->state == regState_DeregDeferred || rInfo->state == regState_Refresh)
4923			{
4924			if (rr->LastAPTime + rr->ThisAPInterval - timenow < 0)
4925				{
4926#if MDNS_DEBUGMSGS
4927				char *op = "(unknown operation)";
4928				if (rInfo->state == regState_Pending) op = "registration";
4929				else if (rInfo->state == regState_DeregPending) op = "deregistration";
4930				else if (rInfo->state == regState_Refresh) op = "refresh";
4931				debugf("Retransmit record %s %##s", op, rr->resrec.name->c);
4932#endif
4933				//LogMsg("Retransmit record %##s", rr->resrec.name->c);
4934				if      (rInfo->state == regState_DeregPending)   SendRecordDeregistration(m, rr);
4935				else                                              sendRecordRegistration(m, rr);
4936				}
4937			if (rr->LastAPTime + rr->ThisAPInterval - nextevent < 0) nextevent = rr->LastAPTime + rr->ThisAPInterval;
4938			}
4939		if (rInfo->lease && rInfo->state == regState_Registered)
4940		    {
4941		    if (rInfo->expire - timenow < 0)
4942		        {
4943		        debugf("refreshing record %##s", rr->resrec.name->c);
4944		        rInfo->state = regState_Refresh;
4945		        sendRecordRegistration(m, rr);
4946		        }
4947		    if (rInfo->expire - nextevent < 0) nextevent = rInfo->expire;
4948		    }
4949		}
4950	return nextevent;
4951	}
4952
4953mDNSlocal mDNSs32 CheckServiceRegistrations(mDNS *m, mDNSs32 timenow)
4954	{
4955	ServiceRecordSet *s = m->uDNS_info.ServiceRegistrations;
4956	uDNS_RegInfo *rInfo;
4957	mDNSs32 nextevent = timenow + MIN_UCAST_PERIODIC_EXEC;
4958
4959	// Note: ServiceRegistrations list is in the order they were created; important for in-order event delivery
4960	while (s)
4961		{
4962		ServiceRecordSet *srs = s;
4963		// NOTE: Must advance s here -- SendServiceDeregistration may delete the object we're looking at,
4964		// and then if we tried to do srs = srs->next at the end we'd be referencing a dead object
4965		s = s->next;
4966
4967		rInfo = &srs->uDNS_info;
4968		if (rInfo->state == regState_Pending || rInfo->state == regState_DeregPending || rInfo->state == regState_DeregDeferred || rInfo->state == regState_Refresh  || rInfo->state == regState_UpdatePending)
4969			{
4970			if (srs->RR_SRV.LastAPTime + srs->RR_SRV.ThisAPInterval - timenow < 0)
4971				{
4972#if MDNS_DEBUGMSGS
4973				char *op = "unknown";
4974				if (rInfo->state == regState_Pending) op = "registration";
4975				else if (rInfo->state == regState_DeregPending) op = "deregistration";
4976				else if (rInfo->state == regState_Refresh) op = "refresh";
4977				else if (rInfo->state == regState_UpdatePending) op = "txt record update";
4978				debugf("Retransmit service %s %##s", op, srs->RR_SRV.resrec.name->c);
4979#endif
4980				if (rInfo->state == regState_DeregPending) { SendServiceDeregistration(m, srs); continue; }
4981				else                                         SendServiceRegistration  (m, srs);
4982				}
4983			if (nextevent - srs->RR_SRV.LastAPTime + srs->RR_SRV.ThisAPInterval > 0)
4984				nextevent = srs->RR_SRV.LastAPTime + srs->RR_SRV.ThisAPInterval;
4985			}
4986
4987		if (rInfo->lease && rInfo->state == regState_Registered)
4988		    {
4989		    if (rInfo->expire - timenow < 0)
4990		        {
4991			    debugf("refreshing service %##s", srs->RR_SRV.resrec.name->c);
4992			    rInfo->state = regState_Refresh;
4993			    SendServiceRegistration(m, srs);
4994		        }
4995		    if (rInfo->expire - nextevent < 0) nextevent = rInfo->expire;
4996		    }
4997		}
4998	return nextevent;
4999	}
5000
5001mDNSexport void uDNS_Execute(mDNS *const m)
5002	{
5003	uDNS_GlobalInfo *u = &m->uDNS_info;
5004	mDNSs32 nexte, timenow = mDNSPlatformTimeNow(m);
5005
5006	u->nextevent = timenow + MIN_UCAST_PERIODIC_EXEC;
5007
5008	if (u->DelaySRVUpdate && u->NextSRVUpdate - timenow < 0)
5009		{
5010		u->DelaySRVUpdate = mDNSfalse;
5011		UpdateSRVRecords(m);
5012		}
5013
5014	nexte = CheckNATMappings(m, timenow);
5015	if (nexte - u->nextevent < 0) u->nextevent = nexte;
5016
5017	if (m->SuppressStdPort53Queries && m->timenow - m->SuppressStdPort53Queries >= 0)
5018		m->SuppressStdPort53Queries = 0; // If suppression time has passed, clear it
5019
5020	nexte = CheckQueries(m, timenow);
5021	if (nexte - u->nextevent < 0) u->nextevent = nexte;
5022
5023	nexte = CheckRecordRegistrations(m, timenow);
5024	if (nexte - u->nextevent < 0) u->nextevent = nexte;
5025
5026	nexte = CheckServiceRegistrations(m, timenow);
5027	if (nexte - u->nextevent < 0) u->nextevent = nexte;
5028
5029	}
5030
5031// ***************************************************************************
5032#if COMPILER_LIKES_PRAGMA_MARK
5033#pragma mark - Startup, Shutdown, and Sleep
5034#endif
5035
5036// DeregisterActive causes active LLQs to be removed from the server, e.g. before sleep.  Pass false
5037// following a location change, as the server will reject deletions from a source address different
5038// from the address on which the LLQ was created.
5039
5040mDNSlocal void SuspendLLQs(mDNS *m, mDNSBool DeregisterActive)
5041	{
5042	DNSQuestion *q;
5043	LLQ_Info *llq;
5044	for (q = m->uDNS_info.ActiveQueries; q; q = q->next)
5045		{
5046		llq = q->uDNS_info.llq;
5047		if (q->LongLived && llq)
5048			{
5049			if (llq->state == LLQ_GetZoneInfo)
5050				{
5051				debugf("Marking %##s suspend-deferred", q->qname.c);
5052				llq->state = LLQ_SuspendDeferred;  // suspend once we're done getting zone info
5053				}
5054			else if (llq->state < LLQ_Suspended)
5055				{
5056				if (DeregisterActive && (llq->state == LLQ_Established || llq->state == LLQ_Refresh))
5057					{ debugf("Deleting LLQ %##s", q->qname.c); sendLLQRefresh(m, q, 0); }
5058				debugf("Marking %##s suspended", q->qname.c);
5059				llq->state = LLQ_Suspended;
5060				ubzero(llq->id, 8);
5061				}
5062			else if (llq->state == LLQ_Poll) { debugf("Marking %##s suspended-poll", q->qname.c); llq->state = LLQ_SuspendedPoll; }
5063			if (llq->NATMap) llq->NATMap = mDNSfalse;  // may not need nat mapping if we restart with new route
5064			}
5065		}
5066	CheckForUnreferencedLLQMapping(m);
5067	}
5068
5069mDNSlocal void RestartQueries(mDNS *m)
5070	{
5071	uDNS_GlobalInfo *u = &m->uDNS_info;
5072	DNSQuestion *q;
5073	LLQ_Info *llqInfo;
5074	mDNSs32 timenow = mDNSPlatformTimeNow(m);
5075
5076	u->CurrentQuery = u->ActiveQueries;
5077	while (u->CurrentQuery)
5078		{
5079		q = u->CurrentQuery;
5080		u->CurrentQuery = u->CurrentQuery->next;
5081		llqInfo = q->uDNS_info.llq;
5082		q->uDNS_info.RestartTime = timenow;
5083		q->uDNS_info.Answered = mDNSfalse;
5084		if (q->LongLived)
5085			{
5086			if (!llqInfo) { LogMsg("Error: RestartQueries - %##s long-lived with NULL info", q->qname.c); continue; }
5087			if (llqInfo->state == LLQ_Suspended || llqInfo->state == LLQ_NatMapWait)
5088				{
5089				llqInfo->ntries = -1;
5090				llqInfo->deriveRemovesOnResume = mDNStrue;
5091				startLLQHandshake(m, llqInfo, mDNStrue);  // we set defer to true since several events that may generate restarts often arrive in rapid succession, and this cuts unnecessary packets
5092				}
5093			else if (llqInfo->state == LLQ_SuspendDeferred)
5094				llqInfo->state = LLQ_GetZoneInfo; // we never finished getting zone data - proceed as usual
5095			else if (llqInfo->state == LLQ_SuspendedPoll)
5096				{
5097				// if we were polling, we may have had bad zone data due to firewall, etc. - refetch
5098				llqInfo->ntries = 0;
5099				llqInfo->deriveRemovesOnResume = mDNStrue;
5100				llqInfo->state = LLQ_GetZoneInfo;
5101				startGetZoneData(&q->qname, m, mDNSfalse, mDNStrue, startLLQHandshakeCallback, llqInfo);
5102				}
5103			}
5104		else { q->LastQTime = timenow; q->ThisQInterval = INIT_UCAST_POLL_INTERVAL; } // trigger poll in 1 second (to reduce packet rate when restarts come in rapid succession)
5105		}
5106	}
5107
5108mDNSexport void mDNS_UpdateLLQs(mDNS *m)
5109	{
5110	uDNS_GlobalInfo *u = &m->uDNS_info;
5111
5112	mDNS_Lock(m);
5113	if (u->LLQNatInfo)
5114		{
5115		DeleteNATPortMapping(m, u->LLQNatInfo, mDNSNULL);
5116		FreeNATInfo(m, u->LLQNatInfo);  // routine clears u->LLQNatInfo ptr
5117		}
5118	SuspendLLQs(m, mDNStrue);
5119	RestartQueries(m);
5120	mDNS_Unlock(m);
5121	}
5122
5123// simplest sleep logic - rather than having sleep states that must be dealt with explicitly in all parts of
5124// the code, we simply send a deregistration, and put the service in Refresh state, with a timeout far enough
5125// in the future that we'll sleep (or the sleep will be cancelled) before it is retransmitted.  Then to wake,
5126// we just move up the timers.
5127
5128
5129
5130mDNSlocal void SleepRecordRegistrations(mDNS *m)
5131	{
5132	DNSMessage msg;
5133	AuthRecord *rr = m->uDNS_info.RecordRegistrations;
5134	mDNSs32 timenow = mDNSPlatformTimeNow(m);
5135
5136	while (rr)
5137		{
5138		if (rr->uDNS_info.state == regState_Registered ||
5139			rr->uDNS_info.state == regState_Refresh)
5140			{
5141			mDNSu8 *ptr = msg.data, *end = (mDNSu8 *)&msg + sizeof(DNSMessage);
5142			InitializeDNSMessage(&msg.h, newMessageID(&m->uDNS_info), UpdateReqFlags);
5143
5144			// construct deletion update
5145			ptr = putZone(&msg, ptr, end, &rr->uDNS_info.zone, mDNSOpaque16fromIntVal(rr->resrec.rrclass));
5146			if (!ptr) { LogMsg("Error: SleepRecordRegistrations - could not put zone"); return; }
5147			ptr = putDeletionRecord(&msg, ptr, &rr->resrec);
5148			if (!ptr) {  LogMsg("Error: SleepRecordRegistrations - could not put deletion record"); return; }
5149
5150			mDNSSendDNSMessage(m, &msg, ptr, mDNSInterface_Any, &rr->uDNS_info.ns, rr->uDNS_info.port, -1, GetAuthInfoForName(&m->uDNS_info, rr->resrec.name));
5151			rr->uDNS_info.state = regState_Refresh;
5152			rr->LastAPTime = timenow;
5153			rr->ThisAPInterval = 300 * mDNSPlatformOneSecond;
5154			}
5155		rr = rr->next;
5156		}
5157	}
5158
5159mDNSlocal void WakeRecordRegistrations(mDNS *m)
5160	{
5161	mDNSs32 timenow = mDNSPlatformTimeNow(m);
5162	AuthRecord *rr = m->uDNS_info.RecordRegistrations;
5163
5164	while (rr)
5165		{
5166		if (rr->uDNS_info.state == regState_Refresh)
5167			{
5168			// trigger slightly delayed refresh (we usually get this message before kernel is ready to send packets)
5169			rr->LastAPTime = timenow;
5170			rr->ThisAPInterval = INIT_UCAST_POLL_INTERVAL;
5171			}
5172		rr = rr->next;
5173		}
5174	}
5175
5176mDNSlocal void SleepServiceRegistrations(mDNS *m)
5177	{
5178	ServiceRecordSet *srs = m->uDNS_info.ServiceRegistrations;
5179	while(srs)
5180		{
5181		uDNS_RegInfo *info = &srs->uDNS_info;
5182		NATTraversalInfo *nat = info->NATinfo;
5183
5184		if (nat)
5185			{
5186			if (nat->state == NATState_Established || nat->state == NATState_Refresh || nat->state == NATState_Legacy)
5187				DeleteNATPortMapping(m, nat, srs);
5188			nat->reg.ServiceRegistration = mDNSNULL;
5189			srs->uDNS_info.NATinfo = mDNSNULL;
5190			FreeNATInfo(m, nat);
5191			}
5192
5193		if (info->state == regState_UpdatePending)
5194			{
5195			// act as if the update succeeded, since we're about to delete the name anyway
5196			AuthRecord *txt = &srs->RR_TXT;
5197			uDNS_RegInfo *txtInfo = &txt->uDNS_info;
5198			info->state = regState_Registered;
5199			// deallocate old RData
5200			if (txtInfo->UpdateRDCallback) txtInfo->UpdateRDCallback(m, txt, txtInfo->OrigRData);
5201			SetNewRData(&txt->resrec, txtInfo->InFlightRData, txtInfo->InFlightRDLen);
5202			txtInfo->OrigRData = mDNSNULL;
5203			txtInfo->InFlightRData = mDNSNULL;
5204			}
5205
5206		if (info->state == regState_Registered || info->state == regState_Refresh)
5207			{
5208			mDNSOpaque16 origid  = srs->uDNS_info.id;
5209			info->state = regState_DeregPending;  // state expected by SendDereg()
5210			SendServiceDeregistration(m, srs);
5211			info->id = origid;
5212			info->state = regState_NoTarget;  // when we wake, we'll re-register (and optionally nat-map) once our address record completes
5213			srs->RR_SRV.resrec.rdata->u.srv.target.c[0] = 0;
5214			}
5215		srs = srs->next;
5216		}
5217	}
5218
5219mDNSlocal void WakeServiceRegistrations(mDNS *m)
5220	{
5221	mDNSs32 timenow = mDNSPlatformTimeNow(m);
5222	ServiceRecordSet *srs = m->uDNS_info.ServiceRegistrations;
5223	while(srs)
5224		{
5225		if (srs->uDNS_info.state == regState_Refresh)
5226			{
5227			// trigger slightly delayed refresh (we usually get this message before kernel is ready to send packets)
5228			srs->RR_SRV.LastAPTime = timenow;
5229			srs->RR_SRV.ThisAPInterval = INIT_UCAST_POLL_INTERVAL;
5230			}
5231		srs = srs->next;
5232		}
5233	}
5234
5235mDNSexport void uDNS_Init(mDNS *const m)
5236	{
5237	mDNSPlatformMemZero(&m->uDNS_info, sizeof(uDNS_GlobalInfo));
5238	m->uDNS_info.nextevent = m->timenow_last + 0x78000000;
5239	}
5240
5241mDNSexport void uDNS_Sleep(mDNS *const m)
5242	{
5243	SuspendLLQs(m, mDNStrue);
5244	SleepServiceRegistrations(m);
5245	SleepRecordRegistrations(m);
5246	}
5247
5248mDNSexport void uDNS_Wake(mDNS *const m)
5249	{
5250	RestartQueries(m);
5251	WakeServiceRegistrations(m);
5252	WakeRecordRegistrations(m);
5253	}
5254