1 /* -*- Mode: C; tab-width: 4 -*-
2 *
3 * Copyright (c) 2002-2003 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
18 NOTE:
19 If you're building an application that uses DNS Service Discovery
20 this is probably NOT the header file you're looking for.
21 In most cases you will want to use /usr/include/dns_sd.h instead.
22
23 This header file defines the lowest level raw interface to mDNSCore,
24 which is appropriate *only* on tiny embedded systems where everything
25 runs in a single address space and memory is extremely constrained.
26 All the APIs here are malloc-free, which means that the caller is
27 responsible for passing in a pointer to the relevant storage that
28 will be used in the execution of that call, and (when called with
29 correct parameters) all the calls are guaranteed to succeed. There
30 is never a case where a call can suffer intermittent failures because
31 the implementation calls malloc() and sometimes malloc() returns NULL
32 because memory is so limited that no more is available.
33 This is primarily for devices that need to have precisely known fixed
34 memory requirements, with absolutely no uncertainty or run-time variation,
35 but that certainty comes at a cost of more difficult programming.
36
37 For applications running on general-purpose desktop operating systems
38 (Mac OS, Linux, Solaris, Windows, etc.) the API you should use is
39 /usr/include/dns_sd.h, which defines the API by which multiple
40 independent client processes communicate their DNS Service Discovery
41 requests to a single "mdnsd" daemon running in the background.
42
43 Even on platforms that don't run multiple independent processes in
44 multiple independent address spaces, you can still use the preferred
45 dns_sd.h APIs by linking in "dnssd_clientshim.c", which implements
46 the standard "dns_sd.h" API calls, allocates any required storage
47 using malloc(), and then calls through to the low-level malloc-free
48 mDNSCore routines defined here. This has the benefit that even though
49 you're running on a small embedded system with a single address space,
50 you can still use the exact same client C code as you'd use on a
51 general-purpose desktop system.
52
53
54 Change History (most recent first):
55
56 $Log: mDNSEmbeddedAPI.h,v $
57 Revision 1.296.2.1 2006/08/29 06:24:22 cheshire
58 Re-licensed mDNSResponder daemon source code under Apache License, Version 2.0
59
60 Revision 1.296 2006/06/29 05:28:01 cheshire
61 Added comment about mDNSlocal and mDNSexport
62
63 Revision 1.295 2006/06/29 03:02:43 cheshire
64 <rdar://problem/4607042> mDNSResponder NXDOMAIN and CNAME support
65
66 Revision 1.294 2006/06/28 06:50:08 cheshire
67 In future we may want to change definition of mDNSs32 from "signed long" to "signed int"
68 I doubt anyone is building mDNSResponder on systems where int is 16-bits,
69 but lets add a compile-time assertion to make sure.
70
71 Revision 1.293 2006/06/12 18:00:43 cheshire
72 To make code a little more defensive, check _ILP64 before _LP64,
73 in case both are set by mistake on some platforms
74
75 Revision 1.292 2006/03/19 17:00:57 cheshire
76 Define symbol MaxMsg instead of using hard-coded constant value '80'
77
78 Revision 1.291 2006/03/19 02:00:07 cheshire
79 <rdar://problem/4073825> Improve logic for delaying packets after repeated interface transitions
80
81 Revision 1.290 2006/03/08 22:42:23 cheshire
82 Fix spelling mistake: LocalReverseMapomain -> LocalReverseMapDomain
83
84 Revision 1.289 2006/02/26 00:54:41 cheshire
85 Fixes to avoid code generation warning/error on FreeBSD 7
86
87 Revision 1.288 2005/12/21 03:24:58 cheshire
88 <rdar://problem/4388858> Code changes required to compile on EFI
89
90 Revision 1.287 2005/10/20 00:10:33 cheshire
91 <rdar://problem/4290265> Add check to avoid crashing NAT gateways that have buggy DNS relay code
92
93 Revision 1.286 2005/09/24 01:09:40 cheshire
94 Fix comment typos
95
96 Revision 1.285 2005/09/16 20:57:47 cheshire
97 Add macro mDNS_TimeNow_NoLock(m) to get properly adjusted time without also acquiring lock
98
99 Revision 1.284 2005/07/29 18:04:22 ksekar
100 <rdar://problem/4137930> Hostname registration should register IPv6 AAAA record with DNS Update
101
102 Revision 1.283 2005/05/13 20:45:09 ksekar
103 <rdar://problem/4074400> Rapid wide-area txt record updates don't work
104
105 Revision 1.282 2005/03/16 00:42:32 ksekar
106 <rdar://problem/4012279> Long-lived queries not working on Windows
107
108 Revision 1.281 2005/02/25 17:47:44 ksekar
109 <rdar://problem/4021868> SendServiceRegistration fails on wake from sleep
110
111 Revision 1.280 2005/02/25 04:21:00 cheshire
112 <rdar://problem/4015377> mDNS -F returns the same domain multiple times with different casing
113
114 Revision 1.279 2005/02/17 01:56:14 cheshire
115 Increase ifname field to 64 bytes
116
117 Revision 1.278 2005/02/09 23:38:51 ksekar
118 <rdar://problem/3993508> Reregister hostname when DNS server changes but IP address does not
119
120 Revision 1.277 2005/02/09 23:31:12 ksekar
121 <rdar://problem/3984374> NAT-PMP response callback should return a boolean indicating if the packet matched the request
122
123 Revision 1.276 2005/02/01 19:33:29 ksekar
124 <rdar://problem/3985239> Keychain format too restrictive
125
126 Revision 1.275 2005/01/27 22:57:55 cheshire
127 Fix compile errors on gcc4
128
129 Revision 1.274 2005/01/19 21:01:54 ksekar
130 <rdar://problem/3955355> uDNS needs to support subtype registration and browsing
131
132 Revision 1.273 2005/01/19 19:15:31 ksekar
133 Refinement to <rdar://problem/3954575> - Simplify mDNS_PurgeResultsForDomain logic and move into daemon layer
134
135 Revision 1.272 2005/01/18 18:10:55 ksekar
136 <rdar://problem/3954575> Use 10.4 resolver API to get search domains
137
138 Revision 1.271 2005/01/15 00:56:41 ksekar
139 <rdar://problem/3954575> Unicast services don't disappear when logging
140 out of VPN
141
142 Revision 1.270 2005/01/14 18:34:22 ksekar
143 <rdar://problem/3954571> Services registered outside of firewall don't succeed after location change
144
145 Revision 1.269 2005/01/11 22:50:52 ksekar
146 Fixed constant naming (was using kLLQ_DefLease for update leases)
147
148 Revision 1.268 2004/12/22 22:25:47 ksekar
149 <rdar://problem/3734265> NATPMP: handle location changes
150
151 Revision 1.267 2004/12/22 00:13:49 ksekar
152 <rdar://problem/3873993> Change version, port, and polling interval for LLQ
153
154 Revision 1.266 2004/12/18 03:13:45 cheshire
155 <rdar://problem/3751638> kDNSServiceInterfaceIndexLocalOnly should return all local records
156
157 Revision 1.265 2004/12/17 23:37:45 cheshire
158 <rdar://problem/3485365> Guard against repeating wireless dissociation/re-association
159 (and other repetitive configuration changes)
160
161 Revision 1.264 2004/12/17 05:25:46 cheshire
162 <rdar://problem/3925163> Shorten DNS-SD queries to avoid NAT bugs
163
164 Revision 1.263 2004/12/16 20:40:25 cheshire
165 Fix compile warnings
166
167 Revision 1.262 2004/12/16 20:13:00 cheshire
168 <rdar://problem/3324626> Cache memory management improvements
169
170 Revision 1.261 2004/12/14 21:21:20 ksekar
171 <rdar://problem/3825979> NAT-PMP: Update response format to contain "Seconds Since Boot"
172
173 Revision 1.260 2004/12/12 23:51:42 ksekar
174 <rdar://problem/3845683> Wide-area registrations should fallback to using DHCP hostname as target
175
176 Revision 1.259 2004/12/11 20:55:29 ksekar
177 <rdar://problem/3916479> Clean up registration state machines
178
179 Revision 1.258 2004/12/10 20:48:32 cheshire
180 <rdar://problem/3705229> Need to pick final EDNS numbers for LLQ and GC
181
182 Revision 1.257 2004/12/10 02:09:23 cheshire
183 <rdar://problem/3898376> Modify default TTLs
184
185 Revision 1.256 2004/12/09 03:15:40 ksekar
186 <rdar://problem/3806610> use _legacy instead of _default to find "empty string" browse domains
187
188 Revision 1.255 2004/12/07 22:48:37 cheshire
189 Tidying
190
191 Revision 1.254 2004/12/07 21:26:04 ksekar
192 <rdar://problem/3908336> DNSServiceRegisterRecord() can crash on deregistration
193
194 Revision 1.253 2004/12/07 20:42:33 cheshire
195 Add explicit context parameter to mDNS_RemoveRecordFromService()
196
197 Revision 1.252 2004/12/07 03:02:12 ksekar
198 Fixed comments, grouped unicast-specific routines together
199
200 Revision 1.251 2004/12/06 21:15:22 ksekar
201 <rdar://problem/3884386> mDNSResponder crashed in CheckServiceRegistrations
202
203 Revision 1.250 2004/12/04 02:12:45 cheshire
204 <rdar://problem/3517236> mDNSResponder puts LargeCacheRecord on the stack
205
206 Revision 1.249 2004/12/03 05:18:33 ksekar
207 <rdar://problem/3810596> mDNSResponder needs to return more specific TSIG errors
208
209 Revision 1.248 2004/12/02 20:03:48 ksekar
210 <rdar://problem/3889647> Still publishes wide-area domains even after switching to a local subnet
211
212 Revision 1.247 2004/12/01 20:57:19 ksekar
213 <rdar://problem/3873921> Wide Area Service Discovery must be split-DNS aware
214
215 Revision 1.246 2004/11/29 23:26:32 cheshire
216 Added NonZeroTime() function, which usually returns the value given, with the exception
217 that if the value given is zero, it returns one instead. For timer values where zero is
218 used to mean "not set", this can be used to ensure that setting them to the result of an
219 interval computation (e.g. "now+interval") does not inadvertently result in a zero value.
220
221 Revision 1.245 2004/11/25 01:28:09 cheshire
222 <rdar://problem/3557050> Need to implement random delay for 'QU' unicast replies (and set cache flush bit too)
223
224 Revision 1.244 2004/11/24 22:00:59 cheshire
225 Move definition of mDNSAddressIsAllDNSLinkGroup() from mDNSMacOSX.c to mDNSEmbeddedAPI.h
226
227 Revision 1.243 2004/11/23 22:43:53 cheshire
228 Tidy up code alignment
229
230 Revision 1.242 2004/11/23 03:39:46 cheshire
231 Let interface name/index mapping capability live directly in JNISupport.c,
232 instead of having to call through to the daemon via IPC to get this information.
233
234 Revision 1.241 2004/11/22 17:16:19 ksekar
235 <rdar://problem/3854298> Unicast services don't disappear when you disable all networking
236
237 Revision 1.240 2004/11/19 02:32:43 ksekar
238 Wide-Area Security: Add LLQ-ID to events
239
240 Revision 1.239 2004/11/15 20:09:23 ksekar
241 <rdar://problem/3719050> Wide Area support for Add/Remove record
242
243 Revision 1.238 2004/11/12 03:16:48 rpantos
244 rdar://problem/3809541 Add mDNSPlatformGetInterfaceByName, mDNSPlatformGetInterfaceName
245
246 Revision 1.237 2004/11/10 20:40:53 ksekar
247 <rdar://problem/3868216> LLQ mobility fragile on non-primary interface
248
249 Revision 1.236 2004/11/01 20:36:11 ksekar
250 <rdar://problem/3802395> mDNSResponder should not receive Keychain Notifications
251
252 Revision 1.235 2004/11/01 17:48:14 cheshire
253 Changed SOA serial number back to signed. RFC 1035 may describe it as "unsigned", but
254 it's wrong. The SOA serial is a modular counter, as explained in "DNS & BIND", page
255 137. Since C doesn't have a modular type, we used signed, C's closest approximation.
256
257 Revision 1.234 2004/10/29 21:59:02 ksekar
258 SOA serial should be a unsigned integer, as per RFC 1035
259
260 Revision 1.233 2004/10/28 03:24:41 cheshire
261 Rename m->CanReceiveUnicastOn as m->CanReceiveUnicastOn5353
262
263 Revision 1.232 2004/10/26 06:20:23 cheshire
264 Add mDNSAddressIsValidNonZero() macro
265
266 Revision 1.231 2004/10/26 06:11:41 cheshire
267 Add improved logging to aid in diagnosis of <rdar://problem/3842714> mDNSResponder crashed
268
269 Revision 1.230 2004/10/26 03:52:02 cheshire
270 Update checkin comments
271
272 Revision 1.229 2004/10/25 19:30:52 ksekar
273 <rdar://problem/3827956> Simplify dynamic host name structures
274
275 Revision 1.228 2004/10/23 01:16:00 cheshire
276 <rdar://problem/3851677> uDNS operations not always reliable on multi-homed hosts
277
278 Revision 1.227 2004/10/22 20:52:07 ksekar
279 <rdar://problem/3799260> Create NAT port mappings for Long Lived Queries
280
281 Revision 1.226 2004/10/20 01:50:40 cheshire
282 <rdar://problem/3844991> Cannot resolve non-local registrations using the mach API
283 Implemented ForceMCast mode for AuthRecords as well as for Questions
284
285 Revision 1.225 2004/10/19 21:33:17 cheshire
286 <rdar://problem/3844991> Cannot resolve non-local registrations using the mach API
287 Added flag 'kDNSServiceFlagsForceMulticast'. Passing through an interface id for a unicast name
288 doesn't force multicast unless you set this flag to indicate explicitly that this is what you want
289
290 Revision 1.224 2004/10/16 00:16:59 cheshire
291 <rdar://problem/3770558> Replace IP TTL 255 check with local subnet source address check
292
293 Revision 1.223 2004/10/15 23:00:17 ksekar
294 <rdar://problem/3799242> Need to update LLQs on location changes
295
296 Revision 1.222 2004/10/12 02:49:20 ksekar
297 <rdar://problem/3831228> Clean up LLQ sleep/wake, error handling
298
299 Revision 1.221 2004/10/10 06:57:15 cheshire
300 Change definition of "localdomain" to make code compile a little smaller
301
302 Revision 1.220 2004/10/06 01:44:19 cheshire
303 <rdar://problem/3813936> Resolving too quickly sometimes returns stale TXT record
304
305 Revision 1.219 2004/10/03 23:18:58 cheshire
306 Move address comparison macros from DNSCommon.h to mDNSEmbeddedAPI.h
307
308 Revision 1.218 2004/10/03 23:14:12 cheshire
309 Add "mDNSEthAddr" type and "zeroEthAddr" constant
310
311 Revision 1.217 2004/09/30 00:24:56 ksekar
312 <rdar://problem/3695802> Dynamically update default registration domains on config change
313
314 Revision 1.216 2004/09/27 23:24:32 cheshire
315 Fix typo: SOA refresh interval is supposed to be unsigned
316
317 Revision 1.215 2004/09/26 23:20:35 ksekar
318 <rdar://problem/3813108> Allow default registrations in multiple wide-area domains
319
320 Revision 1.214 2004/09/25 02:41:39 cheshire
321 <rdar://problem/3637266> Deliver near-pending "remove" events before new "add" events
322
323 Revision 1.213 2004/09/25 02:24:27 cheshire
324 Removed unused rr->UseCount
325
326 Revision 1.212 2004/09/24 20:57:39 cheshire
327 <rdar://problem/3680902> Eliminate inappropriate casts that cause misaligned-address errors
328
329 Revision 1.211 2004/09/24 20:33:22 cheshire
330 Remove unused DNSDigest_MD5 declaration
331
332 Revision 1.210 2004/09/23 20:21:07 cheshire
333 <rdar://problem/3426876> Refine "immediate answer burst; restarting exponential backoff sequence" logic
334 Associate a unique sequence number with each received packet, and only increment the count of recent answer
335 packets if the packet sequence number for this answer record is not one we've already seen and counted.
336
337 Revision 1.209 2004/09/23 20:14:39 cheshire
338 Rename "question->RecentAnswers" to "question->RecentAnswerPkts"
339
340 Revision 1.208 2004/09/23 00:50:53 cheshire
341 <rdar://problem/3419452> Don't send a (DE) if a service is unregistered after wake from sleep
342
343 Revision 1.207 2004/09/22 02:34:46 cheshire
344 Move definitions of default TTL times from mDNS.c to mDNSEmbeddedAPI.h
345
346 Revision 1.206 2004/09/22 00:41:59 cheshire
347 Move tcp connection status codes into the legal range allocated for mDNS use
348
349 Revision 1.205 2004/09/21 23:40:11 ksekar
350 <rdar://problem/3810349> mDNSResponder to return errors on NAT traversal failure
351
352 Revision 1.204 2004/09/21 23:29:50 cheshire
353 <rdar://problem/3680045> DNSServiceResolve should delay sending packets
354
355 Revision 1.203 2004/09/21 20:58:22 cheshire
356 Add ifname field to NetworkInterfaceInfo_struct
357
358 Revision 1.202 2004/09/17 00:46:34 cheshire
359 mDNS_TimeNow should take const mDNS parameter
360
361 Revision 1.201 2004/09/17 00:31:51 cheshire
362 For consistency with ipv6, renamed rdata field 'ip' to 'ipv4'
363
364 Revision 1.200 2004/09/17 00:19:10 cheshire
365 For consistency with AllDNSLinkGroupv6, rename AllDNSLinkGroup to AllDNSLinkGroupv4
366
367 Revision 1.199 2004/09/16 21:59:16 cheshire
368 For consistency with zerov6Addr, rename zeroIPAddr to zerov4Addr
369
370 Revision 1.198 2004/09/16 21:36:36 cheshire
371 <rdar://problem/3803162> Fix unsafe use of mDNSPlatformTimeNow()
372 Changes to add necessary locking calls around unicast DNS operations
373
374 Revision 1.197 2004/09/16 00:24:48 cheshire
375 <rdar://problem/3803162> Fix unsafe use of mDNSPlatformTimeNow()
376
377 Revision 1.196 2004/09/14 23:42:35 cheshire
378 <rdar://problem/3801296> Need to seed random number generator from platform-layer data
379
380 Revision 1.195 2004/09/14 23:27:46 cheshire
381 Fix compile errors
382
383 Revision 1.194 2004/09/10 00:49:57 cheshire
384 <rdar://problem/3787644> Add error code kDNSServiceErr_Firewall, for future use
385
386 Revision 1.193 2004/09/03 19:23:05 ksekar
387 <rdar://problem/3788460>: Need retransmission mechanism for wide-area service registrations
388
389 Revision 1.192 2004/09/02 03:48:47 cheshire
390 <rdar://problem/3709039> Disable targeted unicast query support by default
391 1. New flag kDNSServiceFlagsAllowRemoteQuery to indicate we want to allow remote queries for this record
392 2. New field AllowRemoteQuery in AuthRecord structure
393 3. uds_daemon.c sets AllowRemoteQuery if kDNSServiceFlagsAllowRemoteQuery is set
394 4. mDNS.c only answers remote queries if AllowRemoteQuery is set
395
396 Revision 1.191 2004/08/25 00:37:27 ksekar
397 <rdar://problem/3774635>: Cleanup DynDNS hostname registration code
398
399 Revision 1.190 2004/08/18 17:35:41 ksekar
400 <rdar://problem/3651443>: Feature #9586: Need support for Legacy NAT gateways
401
402 Revision 1.189 2004/08/14 03:22:41 cheshire
403 <rdar://problem/3762579> Dynamic DNS UI <-> mDNSResponder glue
404 Add GetUserSpecifiedDDNSName() routine
405 Convert ServiceRegDomain to domainname instead of C string
406 Replace mDNS_GenerateFQDN/mDNS_GenerateGlobalFQDN with mDNS_SetFQDNs
407
408 Revision 1.188 2004/08/13 23:46:58 cheshire
409 "asyncronous" -> "asynchronous"
410
411 Revision 1.187 2004/08/13 23:37:02 cheshire
412 Now that we do both uDNS and mDNS, global replace "uDNS_info.hostname" with
413 "uDNS_info.UnicastHostname" for clarity
414
415 Revision 1.186 2004/08/13 23:25:00 cheshire
416 Now that we do both uDNS and mDNS, global replace "m->hostname" with
417 "m->MulticastHostname" for clarity
418
419 Revision 1.185 2004/08/12 00:32:36 ksekar
420 <rdar://problem/3759567>: LLQ Refreshes never terminate if unanswered
421
422 Revision 1.184 2004/08/11 17:09:31 cheshire
423 Add comment clarifying the applicability of these APIs
424
425 Revision 1.183 2004/08/10 23:19:14 ksekar
426 <rdar://problem/3722542>: DNS Extension daemon for Wide Area Service Discovery
427 Moved routines/constants to allow extern access for garbage collection daemon
428
429 Revision 1.182 2004/07/30 17:40:06 ksekar
430 <rdar://problem/3739115>: TXT Record updates not available for wide-area services
431
432 Revision 1.181 2004/07/29 19:27:15 ksekar
433 NATPMP Support - minor fixes and cleanup
434
435 Revision 1.180 2004/07/29 02:03:35 ksekar
436 Delete unused #define and structure field
437
438 Revision 1.179 2004/07/26 22:49:30 ksekar
439 <rdar://problem/3651409>: Feature #9516: Need support for NATPMP in client
440
441 Revision 1.178 2004/07/13 21:24:24 rpantos
442 Fix for <rdar://problem/3701120>.
443
444 Revision 1.177 2004/06/05 00:04:26 cheshire
445 <rdar://problem/3668639>: wide-area domains should be returned in reg. domain enumeration
446
447 Revision 1.176 2004/06/04 08:58:29 ksekar
448 <rdar://problem/3668624>: Keychain integration for secure dynamic update
449
450 Revision 1.175 2004/06/04 00:15:06 cheshire
451 Move misplaced brackets
452
453 Revision 1.174 2004/06/03 23:30:16 cheshire
454 Remove extraneous blank lines and white space
455
456 Revision 1.173 2004/06/03 03:09:58 ksekar
457 <rdar://problem/3668626>: Garbage Collection for Dynamic Updates
458
459 Revision 1.172 2004/06/01 23:46:50 ksekar
460 <rdar://problem/3675149>: DynDNS: dynamically look up LLQ/Update ports
461
462 Revision 1.171 2004/05/28 23:42:37 ksekar
463 <rdar://problem/3258021>: Feature: DNS server->client notification on record changes (#7805)
464
465 Revision 1.170 2004/05/18 23:51:25 cheshire
466 Tidy up all checkin comments to use consistent "<rdar://problem/xxxxxxx>" format for bug numbers
467
468 Revision 1.169 2004/05/13 04:54:20 ksekar
469 Unified list copy/free code. Added symetric list for
470
471 Revision 1.168 2004/05/12 22:03:09 ksekar
472 Made GetSearchDomainList a true platform-layer call (declaration moved
473 from mDNSMacOSX.h to mDNSEmbeddedAPI.h), implemented to return "local"
474 only on non-OSX platforms. Changed call to return a copy of the list
475 to avoid shared memory issues. Added a routine to free the list.
476
477 Revision 1.167 2004/04/22 04:07:01 cheshire
478 Fix from Bob Bradley: Don't try to do inline functions on compilers that don't support it
479
480 Revision 1.166 2004/04/22 03:15:56 cheshire
481 Fix use of "struct __attribute__((__packed__))" so it only applies on GCC >= 2.9
482
483 Revision 1.165 2004/04/22 03:05:28 cheshire
484 kDNSClass_ANY should be kDNSQClass_ANY
485
486 Revision 1.164 2004/04/21 02:55:03 cheshire
487 Update comments describing 'InterfaceActive' field
488
489 Revision 1.163 2004/04/21 02:49:11 cheshire
490 To reduce future confusion, renamed 'TxAndRx' to 'McastTxRx'
491
492 Revision 1.162 2004/04/15 00:51:28 bradley
493 Minor tweaks for Windows and C++ builds. Added casts for signed/unsigned integers and 64-bit pointers.
494 Prefix some functions with mDNS to avoid conflicts. Disable benign warnings on Microsoft compilers.
495
496 Revision 1.161 2004/04/14 23:09:28 ksekar
497 Support for TSIG signed dynamic updates.
498
499 Revision 1.160 2004/04/09 17:40:26 cheshire
500 Remove unnecessary "Multicast" field -- it duplicates the semantics of the existing McastTxRx field
501
502 Revision 1.159 2004/04/09 16:37:15 cheshire
503 Suggestion from Bob Bradley:
504 Move NumCacheRecordsForInterfaceID() to DNSCommon.c so it's available to all platform layers
505
506 Revision 1.158 2004/04/02 19:38:33 cheshire
507 Update comment about typical RR TTLs
508
509 Revision 1.157 2004/04/02 19:35:53 cheshire
510 Add clarifying comments about legal mDNSInterfaceID values
511
512 Revision 1.156 2004/04/02 19:19:48 cheshire
513 Add code to do optional logging of multi-packet KA list time intervals
514
515 Revision 1.155 2004/03/24 00:29:45 ksekar
516 Make it safe to call StopQuery in a unicast question callback
517
518 Revision 1.154 2004/03/20 01:05:49 cheshire
519 Test __LP64__ and __ILP64__ to compile properly on a wider range of 64-bit architectures
520
521 Revision 1.153 2004/03/13 01:57:33 ksekar
522 <rdar://problem/3192546>: DynDNS: Dynamic update of service records
523
524 Revision 1.152 2004/03/09 02:27:16 cheshire
525 Remove erroneous underscore in 'packed_struct' (makes no difference now, but might in future)
526
527 Revision 1.151 2004/03/02 03:21:56 cheshire
528 <rdar://problem/3549576> Properly support "_services._dns-sd._udp" meta-queries
529
530 Revision 1.150 2004/02/21 02:06:24 cheshire
531 Can't use anonymous unions -- they're non-standard and don't work on all compilers
532
533 Revision 1.149 2004/02/06 23:04:19 ksekar
534 Basic Dynamic Update support via mDNS_Register (dissabled via
535 UNICAST_REGISTRATION #define)
536
537 Revision 1.148 2004/02/03 19:47:36 ksekar
538 Added an asynchronous state machine mechanism to uDNS.c, including
539 calls to find the parent zone for a domain name. Changes include code
540 in repository previously dissabled via "#if 0 incomplete". Codepath
541 is currently unused, and will be called to create update records, etc.
542
543 Revision 1.147 2004/02/03 18:57:35 cheshire
544 Update comment for "IsLocalDomain()"
545
546 Revision 1.146 2004/01/30 02:20:24 bradley
547 Map inline to __inline when building with Microsoft C compilers since they do not support C99 inline.
548
549 Revision 1.145 2004/01/29 02:59:17 ksekar
550 Unicast DNS: Changed from a resource record oriented question/response
551 matching to packet based matching. New callback architecture allows
552 collections of records in a response to be processed differently
553 depending on the nature of the request, and allows the same structure
554 to be used for internal and client-driven queries with different processing needs.
555
556 Revision 1.144 2004/01/28 20:20:45 ksekar
557 Unified ActiveQueries and ActiveInternalQueries lists, using a flag to
558 demux them. Check-in includes work-in-progress code, #ifdef'd out.
559
560 Revision 1.143 2004/01/28 03:41:00 cheshire
561 <rdar://problem/3541946>: Need ability to do targeted queries as well as multicast queries
562
563 Revision 1.142 2004/01/28 02:30:07 ksekar
564 Added default Search Domains to unicast browsing, controlled via
565 Networking sharing prefs pane. Stopped sending unicast messages on
566 every interface. Fixed unicast resolving via mach-port API.
567
568 Revision 1.141 2004/01/27 20:15:22 cheshire
569 <rdar://problem/3541288>: Time to prune obsolete code for listening on port 53
570
571 Revision 1.140 2004/01/24 23:37:08 cheshire
572 At Kiren's suggestion, made functions to convert mDNSOpaque16s to/from integer values
573
574 Revision 1.139 2004/01/24 08:46:26 bradley
575 Added InterfaceID<->Index platform interfaces since they are now used by all platforms for the DNS-SD APIs.
576
577 Revision 1.138 2004/01/24 04:59:15 cheshire
578 Fixes so that Posix/Linux, OS9, Windows, and VxWorks targets build again
579
580 Revision 1.137 2004/01/24 03:40:56 cheshire
581 Move mDNSAddrIsDNSMulticast() from DNSCommon.h to mDNSEmbeddedAPI.h so clients can use it
582
583 Revision 1.136 2004/01/24 03:38:27 cheshire
584 Fix minor syntactic error: Headers should use "extern" declarations, not "mDNSexport"
585
586 Revision 1.135 2004/01/23 23:23:15 ksekar
587 Added TCP support for truncated unicast messages.
588
589 Revision 1.134 2004/01/22 03:54:11 cheshire
590 Create special meta-interface 'mDNSInterface_ForceMCast' (-2),
591 which means "do this query via multicast, even if it's apparently a unicast domain"
592
593 Revision 1.133 2004/01/22 03:48:41 cheshire
594 Make sure uDNS client doesn't accidentally use query ID zero
595
596 Revision 1.132 2004/01/22 03:43:08 cheshire
597 Export constants like mDNSInterface_LocalOnly so that the client layers can use them
598
599 Revision 1.131 2004/01/21 21:53:18 cheshire
600 <rdar://problem/3448144>: Don't try to receive unicast responses if we're not the first to bind to the UDP port
601
602 Revision 1.130 2003/12/14 05:05:29 cheshire
603 Add comments explaining mDNS_Init_NoCache and mDNS_Init_ZeroCacheSize
604
605 Revision 1.129 2003/12/13 03:05:27 ksekar
606 <rdar://problem/3192548>: DynDNS: Unicast query of service records
607
608 Revision 1.128 2003/12/01 21:44:23 cheshire
609 Add mStatus_BadInterfaceErr = -65552 for consistency with dns_sd.h
610
611 Revision 1.127 2003/12/01 18:26:37 cheshire
612 Also pack the OpaqueXX union types. Otherwise, on some systems, mDNSOpaque16 is four bytes!
613
614 Revision 1.126 2003/12/01 18:23:48 cheshire
615 <rdar://problem/3464646>: Scalar size problem in mDNS code on some 64-bit architectures
616
617 Revision 1.125 2003/11/22 00:18:27 cheshire
618 Add compile-time asserts to verify correct sizes of mDNSu32, mDNSOpaque16, etc.
619
620 Revision 1.124 2003/11/20 22:59:54 cheshire
621 Changed runtime checks in mDNS.c to be compile-time checks in mDNSEmbeddedAPI.h
622 Thanks to Bob Bradley for suggesting the ingenious compiler trick to make this work.
623
624 Revision 1.123 2003/11/20 22:53:01 cheshire
625 Add comment about MAX_ESCAPED_DOMAIN_LABEL
626
627 Revision 1.122 2003/11/20 20:49:53 cheshire
628 Another fix from HP: Use packedstruct macro to ensure proper packing for on-the-wire packet structures
629
630 Revision 1.121 2003/11/20 05:01:38 cheshire
631 Update comments; add explanation of Advertise/DontAdvertiseLocalAddresses
632
633 Revision 1.120 2003/11/14 20:59:08 cheshire
634 Clients can't use AssignDomainName macro because mDNSPlatformMemCopy is defined in mDNSPlatformFunctions.h.
635 Best solution is just to combine mDNSEmbeddedAPI.h and mDNSPlatformFunctions.h into a single file.
636
637 Revision 1.119 2003/11/14 19:47:52 cheshire
638 Define symbol MAX_ESCAPED_DOMAIN_NAME to indicate recommended buffer size for ConvertDomainNameToCString
639
640 Revision 1.118 2003/11/14 19:18:34 cheshire
641 Move AssignDomainName macro to mDNSEmbeddedAPI.h to that client layers can use it too
642
643 Revision 1.117 2003/11/08 23:32:24 cheshire
644 Gave name to anonymous struct, to avoid errors on certain compilers.
645 (Thanks to ramaprasad.kr@hp.com for reporting this.)
646
647 Revision 1.116 2003/11/07 03:32:56 cheshire
648 <rdar://problem/3472153> mDNSResponder delivers answers in inconsistent order
649 This is the real fix. Checkin 1.312 was overly simplistic; Calling GetFreeCacheRR() can sometimes
650 purge records from the cache, causing tail pointer *rp to be stale on return. The correct fix is
651 to maintain a system-wide tail pointer for each cache slot, and then if neccesary GetFreeCacheRR()
652 can update this pointer, so that mDNSCoreReceiveResponse() appends records in the right place.
653
654 Revision 1.115 2003/09/23 00:53:54 cheshire
655 NumFailedProbes should be unsigned
656
657 Revision 1.114 2003/08/29 19:44:15 cheshire
658 <rdar://problem/3400967> Traffic reduction: Eliminate synchronized QUs when a new service appears
659 1. Use m->RandomQueryDelay to impose a random delay in the range 0-500ms on queries
660 that already have at least one unique answer in the cache
661 2. For these queries, go straight to QM, skipping QU
662
663 Revision 1.113 2003/08/21 19:31:58 cheshire
664 Cosmetic: Swap order of fields
665
666 Revision 1.112 2003/08/21 19:27:36 cheshire
667 <rdar://problem/3387878> Traffic reduction: No need to announce record for longer than TTL
668
669 Revision 1.111 2003/08/21 02:21:50 cheshire
670 <rdar://problem/3386473> Efficiency: Reduce repeated queries
671
672 Revision 1.110 2003/08/20 23:39:31 cheshire
673 <rdar://problem/3344098> Review syslog messages, and remove as appropriate
674
675 Revision 1.109 2003/08/19 22:24:10 cheshire
676 Comment change
677
678 Revision 1.108 2003/08/19 22:20:00 cheshire
679 <rdar://problem/3376721> Don't use IPv6 on interfaces that have a routable IPv4 address configured
680 More minor refinements
681
682 Revision 1.107 2003/08/19 06:48:25 cheshire
683 <rdar://problem/3376552> Guard against excessive record updates
684 Each record starts with 10 UpdateCredits.
685 Every update consumes one UpdateCredit.
686 UpdateCredits are replenished at a rate of one one per minute, up to a maximum of 10.
687 As the number of UpdateCredits declines, the number of announcements is similarly scaled back.
688 When fewer than 5 UpdateCredits remain, the first announcement is also delayed by an increasing amount.
689
690 Revision 1.106 2003/08/19 04:49:28 cheshire
691 <rdar://problem/3368159> Interaction between v4, v6 and dual-stack hosts not working quite right
692 1. A dual-stack host should only suppress its own query if it sees the same query from other hosts on BOTH IPv4 and IPv6.
693 2. When we see the first v4 (or first v6) member of a group, we re-trigger questions and probes on that interface.
694 3. When we see the last v4 (or v6) member of a group go away, we revalidate all the records received on that interface.
695
696 Revision 1.105 2003/08/19 02:33:37 cheshire
697 Update comments
698
699 Revision 1.104 2003/08/19 02:31:11 cheshire
700 <rdar://problem/3378386> mDNSResponder overenthusiastic with final expiration queries
701 Final expiration queries now only mark the question for sending on the particular interface
702 pertaining to the record that's expiring.
703
704 Revision 1.103 2003/08/18 19:05:44 cheshire
705 <rdar://problem/3382423> UpdateRecord not working right
706 Added "newrdlength" field to hold new length of updated rdata
707
708 Revision 1.102 2003/08/16 03:39:00 cheshire
709 <rdar://problem/3338440> InterfaceID -1 indicates "local only"
710
711 Revision 1.101 2003/08/15 20:16:02 cheshire
712 <rdar://problem/3366590> mDNSResponder takes too much RPRVT
713 We want to avoid touching the rdata pages, so we don't page them in.
714 1. RDLength was stored with the rdata, which meant touching the page just to find the length.
715 Moved this from the RData to the ResourceRecord object.
716 2. To avoid unnecessarily touching the rdata just to compare it,
717 compute a hash of the rdata and store the hash in the ResourceRecord object.
718
719 Revision 1.100 2003/08/14 19:29:04 cheshire
720 <rdar://problem/3378473> Include cache records in SIGINFO output
721 Moved declarations of DNSTypeName() and GetRRDisplayString to mDNSEmbeddedAPI.h so daemon.c can use them
722
723 Revision 1.99 2003/08/14 02:17:05 cheshire
724 <rdar://problem/3375491> Split generic ResourceRecord type into two separate types: AuthRecord and CacheRecord
725
726 Revision 1.98 2003/08/12 19:56:23 cheshire
727 Update to APSL 2.0
728
729 Revision 1.97 2003/08/12 14:59:27 cheshire
730 <rdar://problem/3374490> Rate-limiting blocks some legitimate responses
731 When setting LastMCTime also record LastMCInterface. When checking LastMCTime to determine
732 whether to suppress the response, also check LastMCInterface to see if it matches.
733
734 Revision 1.96 2003/08/12 13:57:04 cheshire
735 <rdar://problem/3323817> Improve cache performance
736 Changed the number of hash table slots from 37 to 499
737
738 Revision 1.95 2003/08/09 00:55:02 cheshire
739 <rdar://problem/3366553> mDNSResponder is taking 20-30% of the CPU
740 Don't scan the whole cache after every packet.
741
742 Revision 1.94 2003/08/09 00:35:29 cheshire
743
744 Revision 1.93 2003/08/08 18:55:48 cheshire
745 <rdar://problem/3370365> Guard against time going backwards
746
747 Revision 1.92 2003/08/08 18:36:04 cheshire
748 <rdar://problem/3344154> Only need to revalidate on interface removal on platforms that have the PhantomInterfaces bug
749
750 Revision 1.91 2003/08/06 21:33:39 cheshire
751 Fix compiler warnings on PocketPC 2003 (Windows CE)
752
753 Revision 1.90 2003/08/06 20:30:17 cheshire
754 Add structure definition for rdataMX (not currently used, but good to have it for completeness)
755
756 Revision 1.89 2003/08/06 18:58:19 cheshire
757 Update comments
758
759 Revision 1.88 2003/07/24 23:45:44 cheshire
760 To eliminate compiler warnings, changed definition of mDNSBool from
761 "unsigned char" to "int", since "int" is in fact truly the type that C uses
762 for the result of comparison operators (a<b) and logical operators (a||b)
763
764 Revision 1.87 2003/07/22 23:57:20 cheshire
765 Move platform-layer function prototypes from mDNSEmbeddedAPI.h to mDNSPlatformFunctions.h where they belong
766
767 Revision 1.86 2003/07/20 03:52:02 ksekar
768 <rdar://problem/3320722>: Feature: New DNS-SD APIs (#7875) (mDNSResponder component)
769 Added error type for incompatibility between daemon and client versions
770
771 Revision 1.85 2003/07/19 03:23:13 cheshire
772 <rdar://problem/2986147> mDNSResponder needs to receive and cache larger records
773
774 Revision 1.84 2003/07/18 23:52:12 cheshire
775 To improve consistency of field naming, global search-and-replace:
776 NextProbeTime -> NextScheduledProbe
777 NextResponseTime -> NextScheduledResponse
778
779 Revision 1.83 2003/07/18 00:29:59 cheshire
780 <rdar://problem/3268878> Remove mDNSResponder version from packet header and use HINFO record instead
781
782 Revision 1.82 2003/07/17 17:35:04 cheshire
783 <rdar://problem/3325583> Rate-limit responses, to guard against packet flooding
784
785 Revision 1.81 2003/07/16 05:01:36 cheshire
786 Add fields 'LargeAnswers' and 'ExpectUnicastResponse' in preparation for
787 <rdar://problem/3315761> Need to implement "unicast response" request, using top bit of qclass
788
789 Revision 1.80 2003/07/15 01:55:12 cheshire
790 <rdar://problem/3315777> Need to implement service registration with subtypes
791
792 Revision 1.79 2003/07/13 02:28:00 cheshire
793 <rdar://problem/3325166> SendResponses didn't all its responses
794 Delete all references to RRInterfaceActive -- it's now superfluous
795
796 Revision 1.78 2003/07/13 01:47:53 cheshire
797 Fix one error and one warning in the Windows build
798
799 Revision 1.77 2003/07/11 01:32:38 cheshire
800 Syntactic cleanup (no change to funcationality): Now that we only have one host name,
801 rename field "hostname1" to "hostname", and field "RR_A1" to "RR_A".
802
803 Revision 1.76 2003/07/11 01:28:00 cheshire
804 <rdar://problem/3161289> No more local.arpa
805
806 Revision 1.75 2003/07/02 21:19:45 cheshire
807 <rdar://problem/3313413> Update copyright notices, etc., in source code comments
808
809 Revision 1.74 2003/07/02 02:41:23 cheshire
810 <rdar://problem/2986146> mDNSResponder needs to start with a smaller cache and then grow it as needed
811
812 Revision 1.73 2003/06/10 04:24:39 cheshire
813 <rdar://problem/3283637> React when we observe other people query unsuccessfully for a record that's in our cache
814 Some additional refinements:
815 Don't try to do this for unicast-response queries
816 better tracking of Qs and KAs in multi-packet KA lists
817
818 Revision 1.72 2003/06/10 01:46:27 cheshire
819 Add better comments explaining how these data structures are intended to be used from the client layer
820
821 Revision 1.71 2003/06/07 06:45:05 cheshire
822 <rdar://problem/3283666> No need for multiple machines to all be sending the same queries
823
824 Revision 1.70 2003/06/07 04:50:53 cheshire
825 <rdar://problem/3283637> React when we observe other people query unsuccessfully for a record that's in our cache
826
827 Revision 1.69 2003/06/07 04:22:17 cheshire
828 Add MsgBuffer for error log and debug messages
829
830 Revision 1.68 2003/06/07 01:46:38 cheshire
831 <rdar://problem/3283540> When query produces zero results, call mDNS_Reconfirm() on any antecedent records
832
833 Revision 1.67 2003/06/07 01:22:14 cheshire
834 <rdar://problem/3283516> mDNSResponder needs an mDNS_Reconfirm() function
835
836 Revision 1.66 2003/06/07 00:59:43 cheshire
837 <rdar://problem/3283454> Need some randomness to spread queries on the network
838
839 Revision 1.65 2003/06/06 21:41:11 cheshire
840 For consistency, mDNS_StopQuery() should return an mStatus result, just like all the other mDNSCore routines
841
842 Revision 1.64 2003/06/06 21:38:55 cheshire
843 Renamed 'NewData' as 'FreshData' (The data may not be new data, just a refresh of data that we
844 already had in our cache. This refreshes our TTL on the data, but the data itself stays the same.)
845
846 Revision 1.63 2003/06/06 17:20:14 cheshire
847 For clarity, rename question fields name/rrtype/rrclass as qname/qtype/qclass
848 (Global search-and-replace; no functional change to code execution.)
849
850 Revision 1.62 2003/06/04 01:25:33 cheshire
851 <rdar://problem/3274950> Cannot perform multi-packet known-answer suppression messages
852 Display time interval between first and subsequent queries
853
854 Revision 1.61 2003/06/03 05:02:16 cheshire
855 <rdar://problem/3277080> Duplicate registrations not handled as efficiently as they should be
856
857 Revision 1.60 2003/05/31 00:09:49 cheshire
858 <rdar://problem/3274862> Add ability to discover what services are on a network
859
860 Revision 1.59 2003/05/29 06:11:35 cheshire
861 <rdar://problem/3272214>: Report if there appear to be too many "Resolve" callbacks
862
863 Revision 1.58 2003/05/29 05:48:06 cheshire
864 Minor fix for when generating printf warnings: mDNS_snprintf arguments are now 3,4
865
866 Revision 1.57 2003/05/26 03:21:27 cheshire
867 Tidy up address structure naming:
868 mDNSIPAddr => mDNSv4Addr (for consistency with mDNSv6Addr)
869 mDNSAddr.addr.ipv4 => mDNSAddr.ip.v4
870 mDNSAddr.addr.ipv6 => mDNSAddr.ip.v6
871
872 Revision 1.56 2003/05/26 03:01:27 cheshire
873 <rdar://problem/3268904> sprintf/vsprintf-style functions are unsafe; use snprintf/vsnprintf instead
874
875 Revision 1.55 2003/05/26 00:47:30 cheshire
876 Comment clarification
877
878 Revision 1.54 2003/05/24 16:39:48 cheshire
879 <rdar://problem/3268631> SendResponses also needs to handle multihoming better
880
881 Revision 1.53 2003/05/23 02:15:37 cheshire
882 Fixed misleading use of the term "duplicate suppression" where it should have
883 said "known answer suppression". (Duplicate answer suppression is something
884 different, and duplicate question suppression is yet another thing, so the use
885 of the completely vague term "duplicate suppression" was particularly bad.)
886
887 Revision 1.52 2003/05/22 02:29:22 cheshire
888 <rdar://problem/2984918> SendQueries needs to handle multihoming better
889 Complete rewrite of SendQueries. Works much better now :-)
890
891 Revision 1.51 2003/05/21 20:14:55 cheshire
892 Fix comments and warnings
893
894 Revision 1.50 2003/05/14 07:08:36 cheshire
895 <rdar://problem/3159272> mDNSResponder should be smarter about reconfigurations
896 Previously, when there was any network configuration change, mDNSResponder
897 would tear down the entire list of active interfaces and start again.
898 That was very disruptive, and caused the entire cache to be flushed,
899 and caused lots of extra network traffic. Now it only removes interfaces
900 that have really gone, and only adds new ones that weren't there before.
901
902 Revision 1.49 2003/05/07 01:49:36 cheshire
903 Remove "const" in ConstructServiceName prototype
904
905 Revision 1.48 2003/05/07 00:18:44 cheshire
906 Fix typo: "kDNSQClass_Mask" should be "kDNSClass_Mask"
907
908 Revision 1.47 2003/05/06 00:00:46 cheshire
909 <rdar://problem/3248914> Rationalize naming of domainname manipulation functions
910
911 Revision 1.46 2003/04/30 20:39:09 cheshire
912 Add comment
913
914 Revision 1.45 2003/04/29 00:40:50 cheshire
915 Fix compiler warnings
916
917 Revision 1.44 2003/04/26 02:41:56 cheshire
918 <rdar://problem/3241281> Change timenow from a local variable to a structure member
919
920 Revision 1.43 2003/04/25 01:45:56 cheshire
921 <rdar://problem/3240002> mDNS_RegisterNoSuchService needs to include a host name
922
923 Revision 1.42 2003/04/15 20:58:31 jgraessl
924
925 <rdar://problem/3229014> Added a hash to lookup records in the cache.
926
927 Revision 1.41 2003/04/15 18:09:13 jgraessl
928
929 <rdar://problem/3228892>
930 Reviewed by: Stuart Cheshire
931 Added code to keep track of when the next cache item will expire so we can
932 call TidyRRCache only when necessary.
933
934 Revision 1.40 2003/03/29 01:55:19 cheshire
935 <rdar://problem/3212360> mDNSResponder sometimes suffers false self-conflicts when it sees its own packets
936 Solution: Major cleanup of packet timing and conflict handling rules
937
938 Revision 1.39 2003/03/27 03:30:55 cheshire
939 <rdar://problem/3210018> Name conflicts not handled properly, resulting in memory corruption, and eventual crash
940 Problem was that HostNameCallback() was calling mDNS_DeregisterInterface(), which is not safe in a callback
941 Fixes:
942 1. Make mDNS_DeregisterInterface() safe to call from a callback
943 2. Make HostNameCallback() use mDNS_DeadvertiseInterface() instead
944 (it never really needed to deregister the interface at all)
945
946 Revision 1.38 2003/03/15 04:40:36 cheshire
947 Change type called "mDNSOpaqueID" to the more descriptive name "mDNSInterfaceID"
948
949 Revision 1.37 2003/03/14 21:34:11 cheshire
950 <rdar://problem/3176950> Can't setup and print to Lexmark PS printers via Airport Extreme
951 Increase size of cache rdata from 512 to 768
952
953 Revision 1.36 2003/03/05 03:38:35 cheshire
954 <rdar://problem/3185731> Bogus error message in console: died or deallocated, but no record of client can be found!
955 Fixed by leaving client in list after conflict, until client explicitly deallocates
956
957 Revision 1.35 2003/02/21 02:47:54 cheshire
958 <rdar://problem/3099194> mDNSResponder needs performance improvements
959 Several places in the code were calling CacheRRActive(), which searched the entire
960 question list every time, to see if this cache resource record answers any question.
961 Instead, we now have a field "CRActiveQuestion" in the resource record structure
962
963 Revision 1.34 2003/02/21 01:54:08 cheshire
964 <rdar://problem/3099194> mDNSResponder needs performance improvements
965 Switched to using new "mDNS_Execute" model (see "Implementer Notes.txt")
966
967 Revision 1.33 2003/02/20 06:48:32 cheshire
968 <rdar://problem/3169535> Xserve RAID needs to do interface-specific registrations
969 Reviewed by: Josh Graessley, Bob Bradley
970
971 Revision 1.32 2003/01/31 03:35:59 cheshire
972 <rdar://problem/3147097> mDNSResponder sometimes fails to find the correct results
973 When there were *two* active questions in the list, they were incorrectly
974 finding *each other* and *both* being marked as duplicates of another question
975
976 Revision 1.31 2003/01/29 02:46:37 cheshire
977 Fix for IPv6:
978 A physical interface is identified solely by its InterfaceID (not by IP and type).
979 On a given InterfaceID, mDNSCore may send both v4 and v6 multicasts.
980 In cases where the requested outbound protocol (v4 or v6) is not supported on
981 that InterfaceID, the platform support layer should simply discard that packet.
982
983 Revision 1.30 2003/01/29 01:47:08 cheshire
984 Rename 'Active' to 'CRActive' or 'InterfaceActive' for improved clarity
985
986 Revision 1.29 2003/01/28 05:23:43 cheshire
987 <rdar://problem/3147097> mDNSResponder sometimes fails to find the correct results
988 Add 'Active' flag for interfaces
989
990 Revision 1.28 2003/01/28 01:35:56 cheshire
991 Revise comment about ThisQInterval to reflect new semantics
992
993 Revision 1.27 2003/01/13 23:49:42 jgraessl
994 Merged changes for the following fixes in to top of tree:
995 <rdar://problem/3086540> computer name changes not handled properly
996 <rdar://problem/3124348> service name changes are not properly handled
997 <rdar://problem/3124352> announcements sent in pairs, failing chattiness test
998
999 Revision 1.26 2002/12/23 22:13:28 jgraessl
1000
1001 Reviewed by: Stuart Cheshire
1002 Initial IPv6 support for mDNSResponder.
1003
1004 Revision 1.25 2002/09/21 20:44:49 zarzycki
1005 Added APSL info
1006
1007 Revision 1.24 2002/09/19 23:47:35 cheshire
1008 Added mDNS_RegisterNoSuchService() function for assertion of non-existence
1009 of a particular named service
1010
1011 Revision 1.23 2002/09/19 21:25:34 cheshire
1012 mDNS_snprintf() doesn't need to be in a separate file
1013
1014 Revision 1.22 2002/09/19 04:20:43 cheshire
1015 Remove high-ascii characters that confuse some systems
1016
1017 Revision 1.21 2002/09/17 01:06:35 cheshire
1018 Change mDNS_AdvertiseLocalAddresses to be a parameter to mDNS_Init()
1019
1020 Revision 1.20 2002/09/16 18:41:41 cheshire
1021 Merge in license terms from Quinn's copy, in preparation for Darwin release
1022
1023 */
1024
1025 #pragma ident "%Z%%M% %I% %E% SMI"
1026
1027 #ifndef __mDNSClientAPI_h
1028 #define __mDNSClientAPI_h
1029
1030 #if defined(EFI32) || defined(EFI64)
1031 // EFI doesn't have stdarg.h
1032 #include "Tiano.h"
1033 #define va_list VA_LIST
1034 #define va_start(a, b) VA_START(a, b)
1035 #define va_end(a) VA_END(a)
1036 #define va_arg(a, b) VA_ARG(a, b)
1037 #else
1038 #include <stdarg.h> // stdarg.h is required for for va_list support for the mDNS_vsnprintf declaration
1039 #endif
1040
1041 #include "mDNSDebug.h"
1042
1043 #ifdef __cplusplus
1044 extern "C" {
1045 #endif
1046
1047 // ***************************************************************************
1048 // Function scope indicators
1049
1050 // If you see "mDNSlocal" before a function name in a C file, it means the function is not callable outside this file
1051 #ifndef mDNSlocal
1052 #define mDNSlocal static
1053 #endif
1054 // If you see "mDNSexport" before a symbol in a C file, it means the symbol is exported for use by clients
1055 // For every "mDNSexport" in a C file, there needs to be a corresponding "extern" declaration in some header file
1056 // (When a C file #includes a header file, the "extern" declarations tell the compiler:
1057 // "This symbol exists -- but not necessarily in this C file.")
1058 #ifndef mDNSexport
1059 #define mDNSexport
1060 #endif
1061
1062 // Explanation: These local/export markers are a little habit of mine for signaling the programmers' intentions.
1063 // When "mDNSlocal" is just a synonym for "static", and "mDNSexport" is a complete no-op, you could be
1064 // forgiven for asking what purpose they serve. The idea is that if you see "mDNSexport" in front of a
1065 // function definition it means the programmer intended it to be exported and callable from other files
1066 // in the project. If you see "mDNSlocal" in front of a function definition it means the programmer
1067 // intended it to be private to that file. If you see neither in front of a function definition it
1068 // means the programmer forgot (so you should work out which it is supposed to be, and fix it).
1069 // Using "mDNSlocal" instead of "static" makes it easier to do a textual searches for one or the other.
1070 // For example you can do a search for "static" to find if any functions declare any local variables as "static"
1071 // (generally a bad idea unless it's also "const", because static storage usually risks being non-thread-safe)
1072 // without the results being cluttered with hundreds of matches for functions declared static.
1073 // - Stuart Cheshire
1074
1075 // ***************************************************************************
1076 // Structure packing macro
1077
1078 // If we're not using GNUC, it's not fatal.
1079 // Most compilers naturally pack the on-the-wire structures correctly anyway, so a plain "struct" is usually fine.
1080 // In the event that structures are not packed correctly, mDNS_Init() will detect this and report an error, so the
1081 // developer will know what's wrong, and can investigate what needs to be done on that compiler to provide proper packing.
1082 #ifndef packedstruct
1083 #if ((__GNUC__ > 2) || ((__GNUC__ == 2) && (__GNUC_MINOR__ >= 9)))
1084 #define packedstruct struct __attribute__((__packed__))
1085 #define packedunion union __attribute__((__packed__))
1086 #else
1087 #define packedstruct struct
1088 #define packedunion union
1089 #endif
1090 #endif
1091
1092 // ***************************************************************************
1093 #if 0
1094 #pragma mark - DNS Resource Record class and type constants
1095 #endif
1096
1097 typedef enum // From RFC 1035
1098 {
1099 kDNSClass_IN = 1, // Internet
1100 kDNSClass_CS = 2, // CSNET
1101 kDNSClass_CH = 3, // CHAOS
1102 kDNSClass_HS = 4, // Hesiod
1103 kDNSClass_NONE = 254, // Used in DNS UPDATE [RFC 2136]
1104
1105 kDNSClass_Mask = 0x7FFF,// Multicast DNS uses the bottom 15 bits to identify the record class...
1106 kDNSClass_UniqueRRSet = 0x8000,// ... and the top bit indicates that all other cached records are now invalid
1107
1108 kDNSQClass_ANY = 255, // Not a DNS class, but a DNS query class, meaning "all classes"
1109 kDNSQClass_UnicastResponse = 0x8000 // Top bit set in a question means "unicast response acceptable"
1110 } DNS_ClassValues;
1111
1112 typedef enum // From RFC 1035
1113 {
1114 kDNSType_A = 1, // 1 Address
1115 kDNSType_NS, // 2 Name Server
1116 kDNSType_MD, // 3 Mail Destination
1117 kDNSType_MF, // 4 Mail Forwarder
1118 kDNSType_CNAME, // 5 Canonical Name
1119 kDNSType_SOA, // 6 Start of Authority
1120 kDNSType_MB, // 7 Mailbox
1121 kDNSType_MG, // 8 Mail Group
1122 kDNSType_MR, // 9 Mail Rename
1123 kDNSType_NULL, // 10 NULL RR
1124 kDNSType_WKS, // 11 Well-known-service
1125 kDNSType_PTR, // 12 Domain name pointer
1126 kDNSType_HINFO, // 13 Host information
1127 kDNSType_MINFO, // 14 Mailbox information
1128 kDNSType_MX, // 15 Mail Exchanger
1129 kDNSType_TXT, // 16 Arbitrary text string
1130
1131 kDNSType_AAAA = 28, // 28 IPv6 address
1132 kDNSType_SRV = 33, // 33 Service record
1133 kDNSType_OPT = 41, // EDNS0 OPT record
1134 kDNSType_TSIG = 250, // 250 Transaction Signature
1135
1136 kDNSQType_ANY = 255 // Not a DNS type, but a DNS query type, meaning "all types"
1137 } DNS_TypeValues;
1138
1139 // ***************************************************************************
1140 #if 0
1141 #pragma mark - Simple types
1142 #endif
1143
1144 // mDNS defines its own names for these common types to simplify portability across
1145 // multiple platforms that may each have their own (different) names for these types.
1146 typedef int mDNSBool;
1147 typedef signed char mDNSs8;
1148 typedef unsigned char mDNSu8;
1149 typedef signed short mDNSs16;
1150 typedef unsigned short mDNSu16;
1151
1152 // <http://gcc.gnu.org/onlinedocs/gcc-3.3.3/cpp/Common-Predefined-Macros.html> says
1153 // __LP64__ _LP64
1154 // These macros are defined, with value 1, if (and only if) the compilation is
1155 // for a target where long int and pointer both use 64-bits and int uses 32-bit.
1156 // <http://www.intel.com/software/products/compilers/clin/docs/ug/lin1077.htm> says
1157 // Macro Name __LP64__ Value 1
1158 // A quick Google search for "defined(__LP64__)" OR "#ifdef __LP64__" gives 2590 hits and
1159 // a search for "#if __LP64__" gives only 12, so I think we'll go with the majority and use defined()
1160 #if defined(_ILP64) || defined(__ILP64__)
1161 typedef signed int32 mDNSs32;
1162 typedef unsigned int32 mDNSu32;
1163 #elif defined(_LP64) || defined(__LP64__)
1164 typedef signed int mDNSs32;
1165 typedef unsigned int mDNSu32;
1166 #else
1167 typedef signed long mDNSs32;
1168 typedef unsigned long mDNSu32;
1169 //typedef signed int mDNSs32;
1170 //typedef unsigned int mDNSu32;
1171 #endif
1172
1173 // To enforce useful type checking, we make mDNSInterfaceID be a pointer to a dummy struct
1174 // This way, mDNSInterfaceIDs can be assigned, and compared with each other, but not with other types
1175 // Declaring the type to be the typical generic "void *" would lack this type checking
1176 typedef struct mDNSInterfaceID_dummystruct { void *dummy; } *mDNSInterfaceID;
1177
1178 // These types are for opaque two- and four-byte identifiers.
1179 // The "NotAnInteger" fields of the unions allow the value to be conveniently passed around in a
1180 // register for the sake of efficiency, and compared for equality or inequality, but don't forget --
1181 // just because it is in a register doesn't mean it is an integer. Operations like greater than,
1182 // less than, add, multiply, increment, decrement, etc., are undefined for opaque identifiers,
1183 // and if you make the mistake of trying to do those using the NotAnInteger field, then you'll
1184 // find you get code that doesn't work consistently on big-endian and little-endian machines.
1185 typedef packedunion { mDNSu8 b[ 2]; mDNSu16 NotAnInteger; } mDNSOpaque16;
1186 typedef packedunion { mDNSu8 b[ 4]; mDNSu32 NotAnInteger; } mDNSOpaque32;
1187 typedef packedunion { mDNSu8 b[ 6]; mDNSu16 w[3]; mDNSu32 l[1]; } mDNSOpaque48;
1188 typedef packedunion { mDNSu8 b[16]; mDNSu16 w[8]; mDNSu32 l[4]; } mDNSOpaque128;
1189
1190 typedef mDNSOpaque16 mDNSIPPort; // An IP port is a two-byte opaque identifier (not an integer)
1191 typedef mDNSOpaque32 mDNSv4Addr; // An IP address is a four-byte opaque identifier (not an integer)
1192 typedef mDNSOpaque128 mDNSv6Addr; // An IPv6 address is a 16-byte opaque identifier (not an integer)
1193 typedef mDNSOpaque48 mDNSEthAddr; // An Ethernet address is a six-byte opaque identifier (not an integer)
1194
1195 enum
1196 {
1197 mDNSAddrType_None = 0,
1198 mDNSAddrType_IPv4 = 4,
1199 mDNSAddrType_IPv6 = 6,
1200 mDNSAddrType_Unknown = ~0 // Special marker value used in known answer list recording
1201 };
1202
1203 typedef struct
1204 {
1205 mDNSs32 type;
1206 union { mDNSv6Addr v6; mDNSv4Addr v4; } ip;
1207 } mDNSAddr;
1208
1209 enum { mDNSfalse = 0, mDNStrue = 1 };
1210
1211 #define mDNSNULL 0L
1212
1213 enum
1214 {
1215 mStatus_Waiting = 1,
1216 mStatus_NoError = 0,
1217
1218 // mDNS return values are in the range FFFE FF00 (-65792) to FFFE FFFF (-65537)
1219 // The top end of the range (FFFE FFFF) is used for error codes;
1220 // the bottom end of the range (FFFE FF00) is used for non-error values;
1221
1222 // Error codes:
1223 mStatus_UnknownErr = -65537, // First value: 0xFFFE FFFF
1224 mStatus_NoSuchNameErr = -65538,
1225 mStatus_NoMemoryErr = -65539,
1226 mStatus_BadParamErr = -65540,
1227 mStatus_BadReferenceErr = -65541,
1228 mStatus_BadStateErr = -65542,
1229 mStatus_BadFlagsErr = -65543,
1230 mStatus_UnsupportedErr = -65544,
1231 mStatus_NotInitializedErr = -65545,
1232 mStatus_NoCache = -65546,
1233 mStatus_AlreadyRegistered = -65547,
1234 mStatus_NameConflict = -65548,
1235 mStatus_Invalid = -65549,
1236 mStatus_Firewall = -65550,
1237 mStatus_Incompatible = -65551,
1238 mStatus_BadInterfaceErr = -65552,
1239 mStatus_Refused = -65553,
1240 mStatus_NoSuchRecord = -65554,
1241 mStatus_NoAuth = -65555,
1242 mStatus_NoSuchKey = -65556,
1243 mStatus_NATTraversal = -65557,
1244 mStatus_DoubleNAT = -65558,
1245 mStatus_BadTime = -65559,
1246 mStatus_BadSig = -65560, // while we define this per RFC 2845, BIND 9 returns Refused for bad/missing signatures
1247 mStatus_BadKey = -65561,
1248 mStatus_TransientErr = -65562, // transient failures, e.g. sending packets shortly after a network transition or wake from sleep
1249 // -65563 to -65786 currently unused; available for allocation
1250
1251 // tcp connection status
1252 mStatus_ConnPending = -65787,
1253 mStatus_ConnFailed = -65788,
1254 mStatus_ConnEstablished = -65789,
1255
1256 // Non-error values:
1257 mStatus_GrowCache = -65790,
1258 mStatus_ConfigChanged = -65791,
1259 mStatus_MemFree = -65792 // Last value: 0xFFFE FF00
1260
1261 // mStatus_MemFree is the last legal mDNS error code, at the end of the range allocated for mDNS
1262 };
1263
1264 typedef mDNSs32 mStatus;
1265
1266 // RFC 1034/1035 specify that a domain label consists of a length byte plus up to 63 characters
1267 #define MAX_DOMAIN_LABEL 63
1268 typedef struct { mDNSu8 c[ 64]; } domainlabel; // One label: length byte and up to 63 characters
1269
1270 // RFC 1034/1035 specify that a domain name, including length bytes, data bytes, and terminating zero, may be up to 255 bytes long
1271 #define MAX_DOMAIN_NAME 255
1272 typedef struct { mDNSu8 c[256]; } domainname; // Up to 255 bytes of length-prefixed domainlabels
1273
1274 typedef struct { mDNSu8 c[256]; } UTF8str255; // Null-terminated C string
1275
1276 // The longest legal textual form of a DNS name is 1005 bytes, including the C-string terminating NULL at the end.
1277 // Explanation:
1278 // When a native domainname object is converted to printable textual form using ConvertDomainNameToCString(),
1279 // non-printing characters are represented in the conventional DNS way, as '\ddd', where ddd is a three-digit decimal number.
1280 // The longest legal domain name is 255 bytes, in the form of four labels as shown below:
1281 // Length byte, 63 data bytes, length byte, 63 data bytes, length byte, 63 data bytes, length byte, 61 data bytes, zero byte.
1282 // Each label is encoded textually as characters followed by a trailing dot.
1283 // If every character has to be represented as a four-byte escape sequence, then this makes the maximum textual form four labels
1284 // plus the C-string terminating NULL as shown below:
1285 // 63*4+1 + 63*4+1 + 63*4+1 + 61*4+1 + 1 = 1005.
1286 // Note that MAX_ESCAPED_DOMAIN_LABEL is not normally used: If you're only decoding a single label, escaping is usually not required.
1287 // It is for domain names, where dots are used as label separators, that proper escaping is vital.
1288 #define MAX_ESCAPED_DOMAIN_LABEL 254
1289 #define MAX_ESCAPED_DOMAIN_NAME 1005
1290
1291 // Most records have a TTL of 75 minutes, so that their 80% cache-renewal query occurs once per hour.
1292 // For records containing a hostname (in the name on the left, or in the rdata on the right),
1293 // like A, AAAA, reverse-mapping PTR, and SRV, we use a two-minute TTL by default, because we don't want
1294 // them to hang around for too long in the cache if the host in question crashes or otherwise goes away.
1295 // Wide-area service discovery records have a very short TTL to avoid poluting intermediate caches with
1296 // dynamic records. When discovered via Long Lived Queries (with change notifications), resource record
1297 // TTLs can be safely ignored.
1298
1299 #define kStandardTTL (3600UL * 100 / 80)
1300 #define kHostNameTTL 120UL
1301 #define kWideAreaTTL 3
1302
1303 #define DefaultTTLforRRType(X) (((X) == kDNSType_A || (X) == kDNSType_AAAA || (X) == kDNSType_SRV) ? kHostNameTTL : kStandardTTL)
1304
1305 // ***************************************************************************
1306 #if 0
1307 #pragma mark - DNS Message structures
1308 #endif
1309
1310 #define mDNS_numZones numQuestions
1311 #define mDNS_numPrereqs numAnswers
1312 #define mDNS_numUpdates numAuthorities
1313
1314 typedef packedstruct
1315 {
1316 mDNSOpaque16 id;
1317 mDNSOpaque16 flags;
1318 mDNSu16 numQuestions;
1319 mDNSu16 numAnswers;
1320 mDNSu16 numAuthorities;
1321 mDNSu16 numAdditionals;
1322 } DNSMessageHeader;
1323
1324 // We can send and receive packets up to 9000 bytes (Ethernet Jumbo Frame size, if that ever becomes widely used)
1325 // However, in the normal case we try to limit packets to 1500 bytes so that we don't get IP fragmentation on standard Ethernet
1326 // 40 (IPv6 header) + 8 (UDP header) + 12 (DNS message header) + 1440 (DNS message body) = 1500 total
1327 #define AbsoluteMaxDNSMessageData 8940
1328 #define NormalMaxDNSMessageData 1440
1329 typedef packedstruct
1330 {
1331 DNSMessageHeader h; // Note: Size 12 bytes
1332 mDNSu8 data[AbsoluteMaxDNSMessageData]; // 40 (IPv6) + 8 (UDP) + 12 (DNS header) + 8940 (data) = 9000
1333 } DNSMessage;
1334
1335 // ***************************************************************************
1336 #if 0
1337 #pragma mark - Resource Record structures
1338 #endif
1339
1340 // Authoritative Resource Records:
1341 // There are four basic types: Shared, Advisory, Unique, Known Unique
1342
1343 // * Shared Resource Records do not have to be unique
1344 // -- Shared Resource Records are used for DNS-SD service PTRs
1345 // -- It is okay for several hosts to have RRs with the same name but different RDATA
1346 // -- We use a random delay on responses to reduce collisions when all the hosts respond to the same query
1347 // -- These RRs typically have moderately high TTLs (e.g. one hour)
1348 // -- These records are announced on startup and topology changes for the benefit of passive listeners
1349 // -- These records send a goodbye packet when deregistering
1350 //
1351 // * Advisory Resource Records are like Shared Resource Records, except they don't send a goodbye packet
1352 //
1353 // * Unique Resource Records should be unique among hosts within any given mDNS scope
1354 // -- The majority of Resource Records are of this type
1355 // -- If two entities on the network have RRs with the same name but different RDATA, this is a conflict
1356 // -- Responses may be sent immediately, because only one host should be responding to any particular query
1357 // -- These RRs typically have low TTLs (e.g. a few minutes)
1358 // -- On startup and after topology changes, a host issues queries to verify uniqueness
1359
1360 // * Known Unique Resource Records are treated like Unique Resource Records, except that mDNS does
1361 // not have to verify their uniqueness because this is already known by other means (e.g. the RR name
1362 // is derived from the host's IP or Ethernet address, which is already known to be a unique identifier).
1363
1364 // Summary of properties of different record types:
1365 // Probe? Does this record type send probes before announcing?
1366 // Conflict? Does this record type react if we observe an apparent conflict?
1367 // Goodbye? Does this record type send a goodbye packet on departure?
1368 //
1369 // Probe? Conflict? Goodbye? Notes
1370 // Unregistered Should not appear in any list (sanity check value)
1371 // Shared No No Yes e.g. Service PTR record
1372 // Deregistering No No Yes Shared record about to announce its departure and leave the list
1373 // Advisory No No No
1374 // Unique Yes Yes No Record intended to be unique -- will probe to verify
1375 // Verified Yes Yes No Record has completed probing, and is verified unique
1376 // KnownUnique No Yes No Record is assumed by other means to be unique
1377
1378 // Valid lifecycle of a record:
1379 // Unregistered -> Shared -> Deregistering -(goodbye)-> Unregistered
1380 // Unregistered -> Advisory -> Unregistered
1381 // Unregistered -> Unique -(probe)-> Verified -> Unregistered
1382 // Unregistered -> KnownUnique -> Unregistered
1383
1384 // Each Authoritative kDNSRecordType has only one bit set. This makes it easy to quickly see if a record
1385 // is one of a particular set of types simply by performing the appropriate bitwise masking operation.
1386
1387 // Cache Resource Records (received from the network):
1388 // There are four basic types: Answer, Unique Answer, Additional, Unique Additional
1389 // Bit 7 (the top bit) of kDNSRecordType is always set for Cache Resource Records; always clear for Authoritative Resource Records
1390 // Bit 6 (value 0x40) is set for answer records; clear for additional records
1391 // Bit 5 (value 0x20) is set for records received with the kDNSClass_UniqueRRSet
1392
1393 enum
1394 {
1395 kDNSRecordTypeUnregistered = 0x00, // Not currently in any list
1396 kDNSRecordTypeDeregistering = 0x01, // Shared record about to announce its departure and leave the list
1397
1398 kDNSRecordTypeUnique = 0x02, // Will become a kDNSRecordTypeVerified when probing is complete
1399
1400 kDNSRecordTypeAdvisory = 0x04, // Like Shared, but no goodbye packet
1401 kDNSRecordTypeShared = 0x08, // Shared means record name does not have to be unique -- use random delay on responses
1402
1403 kDNSRecordTypeVerified = 0x10, // Unique means mDNS should check that name is unique (and then send immediate responses)
1404 kDNSRecordTypeKnownUnique = 0x20, // Known Unique means mDNS can assume name is unique without checking
1405 // For Dynamic Update records, Known Unique means the record must already exist on the server.
1406 kDNSRecordTypeUniqueMask = (kDNSRecordTypeUnique | kDNSRecordTypeVerified | kDNSRecordTypeKnownUnique),
1407 kDNSRecordTypeActiveMask = (kDNSRecordTypeAdvisory | kDNSRecordTypeShared | kDNSRecordTypeVerified | kDNSRecordTypeKnownUnique),
1408
1409 kDNSRecordTypePacketAdd = 0x80, // Received in the Additional Section of a DNS Response
1410 kDNSRecordTypePacketAddUnique = 0x90, // Received in the Additional Section of a DNS Response with kDNSClass_UniqueRRSet set
1411 kDNSRecordTypePacketAuth = 0xA0, // Received in the Authorities Section of a DNS Response
1412 kDNSRecordTypePacketAuthUnique = 0xB0, // Received in the Authorities Section of a DNS Response with kDNSClass_UniqueRRSet set
1413 kDNSRecordTypePacketAns = 0xC0, // Received in the Answer Section of a DNS Response
1414 kDNSRecordTypePacketAnsUnique = 0xD0, // Received in the Answer Section of a DNS Response with kDNSClass_UniqueRRSet set
1415
1416 kDNSRecordTypePacketAnsMask = 0x40, // True for PacketAns and PacketAnsUnique
1417 kDNSRecordTypePacketUniqueMask = 0x10 // True for PacketAddUnique, PacketAnsUnique, PacketAuthUnique
1418 };
1419
1420 typedef packedstruct { mDNSu16 priority; mDNSu16 weight; mDNSIPPort port; domainname target; } rdataSRV;
1421 typedef packedstruct { mDNSu16 preference; domainname exchange; } rdataMX;
1422 typedef packedstruct
1423 {
1424 domainname mname;
1425 domainname rname;
1426 mDNSs32 serial; // Modular counter; increases when zone changes
1427 mDNSu32 refresh; // Time in seconds that a slave waits after successful replication of the database before it attempts replication again
1428 mDNSu32 retry; // Time in seconds that a slave waits after an unsuccessful replication attempt before it attempts replication again
1429 mDNSu32 expire; // Time in seconds that a slave holds on to old data while replication attempts remain unsuccessful
1430 mDNSu32 min; // Nominally the minimum record TTL for this zone, in seconds; also used for negative caching.
1431 } rdataSOA;
1432
1433 typedef packedstruct
1434 {
1435 mDNSu16 vers;
1436 mDNSu16 llqOp;
1437 mDNSu16 err;
1438 mDNSu8 id[8];
1439 mDNSu32 lease;
1440 } LLQOptData;
1441
1442 #define LLQ_OPTLEN ((3 * sizeof(mDNSu16)) + 8 + sizeof(mDNSu32))
1443 // Windows adds pad bytes to sizeof(LLQOptData). Use this macro when setting length fields or validating option rdata from
1444 // off the wire. Use sizeof(LLQOptData) when dealing with structures (e.g. memcpy). Never memcpy between on-the-wire
1445 // representation and a structure
1446
1447 // NOTE: rdataOpt format may be repeated an arbitrary number of times in a single resource record
1448 typedef packedstruct
1449 {
1450 mDNSu16 opt;
1451 mDNSu16 optlen;
1452 union { LLQOptData llq; mDNSu32 lease; } OptData;
1453 } rdataOpt;
1454
1455 // StandardAuthRDSize is 264 (256+8), which is large enough to hold a maximum-sized SRV record
1456 // MaximumRDSize is 8K the absolute maximum we support (at least for now)
1457 #define StandardAuthRDSize 264
1458 #define MaximumRDSize 8192
1459
1460 // InlineCacheRDSize is 68
1461 // Records received from the network with rdata this size or less have their rdata stored right in the CacheRecord object
1462 // Records received from the network with rdata larger than this have additional storage allocated for the rdata
1463 // A quick unscientific sample from a busy network at Apple with lots of machines revealed this:
1464 // 1461 records in cache
1465 // 292 were one-byte TXT records
1466 // 136 were four-byte A records
1467 // 184 were sixteen-byte AAAA records
1468 // 780 were various PTR, TXT and SRV records from 12-64 bytes
1469 // Only 69 records had rdata bigger than 64 bytes
1470 // Note that since CacheRecord object and a CacheGroup object are allocated out of the same pool, it's sensible to
1471 // have them both be the same size. Making one smaller without making the other smaller won't actually save any memory.
1472 #define InlineCacheRDSize 68
1473
1474 #define InlineCacheGroupNameSize 144
1475
1476 typedef union
1477 {
1478 mDNSu8 data[StandardAuthRDSize];
1479 mDNSv4Addr ipv4; // For 'A' record
1480 mDNSv6Addr ipv6; // For 'AAAA' record
1481 domainname name; // For PTR, NS, and CNAME records
1482 UTF8str255 txt; // For TXT record
1483 rdataSRV srv; // For SRV record
1484 rdataMX mx; // For MX record
1485 rdataSOA soa; // For SOA record
1486 rdataOpt opt; // For eDNS0 opt record
1487 } RDataBody;
1488
1489 typedef struct
1490 {
1491 mDNSu16 MaxRDLength; // Amount of storage allocated for rdata (usually sizeof(RDataBody))
1492 RDataBody u;
1493 } RData;
1494 #define sizeofRDataHeader (sizeof(RData) - sizeof(RDataBody))
1495
1496 typedef struct AuthRecord_struct AuthRecord;
1497 typedef struct CacheRecord_struct CacheRecord;
1498 typedef struct CacheGroup_struct CacheGroup;
1499 typedef struct DNSQuestion_struct DNSQuestion;
1500 typedef struct mDNS_struct mDNS;
1501 typedef struct mDNS_PlatformSupport_struct mDNS_PlatformSupport;
1502 typedef struct NATTraversalInfo_struct NATTraversalInfo;
1503
1504 // Note: Within an mDNSRecordCallback mDNS all API calls are legal except mDNS_Init(), mDNS_Close(), mDNS_Execute()
1505 typedef void mDNSRecordCallback(mDNS *const m, AuthRecord *const rr, mStatus result);
1506
1507 // Note:
1508 // Restrictions: An mDNSRecordUpdateCallback may not make any mDNS API calls.
1509 // The intent of this callback is to allow the client to free memory, if necessary.
1510 // The internal data structures of the mDNS code may not be in a state where mDNS API calls may be made safely.
1511 typedef void mDNSRecordUpdateCallback(mDNS *const m, AuthRecord *const rr, RData *OldRData);
1512
1513 typedef struct
1514 {
1515 mDNSu8 RecordType; // See enum above
1516 mDNSInterfaceID InterfaceID; // Set if this RR is specific to one interface
1517 // For records received off the wire, InterfaceID is *always* set to the receiving interface
1518 // For our authoritative records, InterfaceID is usually zero, except for those few records
1519 // that are interface-specific (e.g. address records, especially linklocal addresses)
1520 domainname *name;
1521 mDNSu16 rrtype;
1522 mDNSu16 rrclass;
1523 mDNSu32 rroriginalttl; // In seconds
1524 mDNSu16 rdlength; // Size of the raw rdata, in bytes
1525 mDNSu16 rdestimate; // Upper bound on size of rdata after name compression
1526 mDNSu32 namehash; // Name-based (i.e. case-insensitive) hash of name
1527 mDNSu32 rdatahash; // For rdata containing domain name (e.g. PTR, SRV, CNAME etc.), case-insensitive name hash
1528 // else, for all other rdata, 32-bit hash of the raw rdata
1529 // Note: This requirement is important. Various routines like AddAdditionalsToResponseList(),
1530 // ReconfirmAntecedents(), etc., use rdatahash as a pre-flight check to see
1531 // whether it's worth doing a full SameDomainName() call. If the rdatahash
1532 // is not a correct case-insensitive name hash, they'll get false negatives.
1533 RData *rdata; // Pointer to storage for this rdata
1534 } ResourceRecord;
1535
1536 // Unless otherwise noted, states may apply to either independent record registrations or service registrations
1537 typedef enum
1538 {
1539 regState_FetchingZoneData = 1, // getting info - update not sent
1540 regState_Pending = 2, // update sent, reply not received
1541 regState_Registered = 3, // update sent, reply received
1542 regState_DeregPending = 4, // dereg sent, reply not received
1543 regState_DeregDeferred = 5, // dereg requested while in Pending state - send dereg AFTER registration is confirmed
1544 regState_Cancelled = 6, // update not sent, reg. cancelled by client
1545 regState_Unregistered = 8, // not in any list
1546 regState_Refresh = 9, // outstanding refresh (or target change) message
1547 regState_NATMap = 10, // establishing NAT port mapping or learning public address
1548 regState_UpdatePending = 11, // update in flight as result of mDNS_Update call
1549 regState_NoTarget = 12, // service registration pending registration of hostname (ServiceRegistrations only)
1550 regState_ExtraQueued = 13, // extra record to be registered upon completion of service registration (RecordRegistrations only)
1551 regState_NATError = 14 // unable to complete NAT traversal
1552 } regState_t;
1553
1554 // context for both ServiceRecordSet and individual AuthRec structs
1555 typedef struct
1556 {
1557 // registration/lease state
1558 regState_t state;
1559 mDNSBool lease; // dynamic update contains (should contain) lease option
1560 mDNSs32 expire; // expiration of lease (-1 for static)
1561 mDNSBool TestForSelfConflict; // on name conflict, check if we're just seeing our own orphaned records
1562
1563 // identifier to match update request and response
1564 mDNSOpaque16 id;
1565
1566 // server info
1567 domainname zone; // the zone that is updated
1568 mDNSAddr ns; // primary name server for the record's zone !!!KRS not technically correct to cache longer than TTL
1569 mDNSIPPort port; // port on which server accepts dynamic updates
1570
1571 // NAT traversal context
1572 NATTraversalInfo *NATinfo; // may be NULL
1573
1574 // state for deferred operations
1575 mDNSBool ClientCallbackDeferred; // invoke client callback on completion of pending operation(s)
1576 mStatus DeferredStatus; // status to deliver when above flag is set
1577 mDNSBool SRVUpdateDeferred; // do we need to change target or port once current operation completes?
1578 mDNSBool SRVChanged; // temporarily deregistered service because its SRV target or port changed
1579
1580 // uDNS_UpdateRecord support fields
1581 RData *OrigRData; mDNSu16 OrigRDLen; // previously registered, being deleted
1582 RData *InFlightRData; mDNSu16 InFlightRDLen; // currently being registered
1583 RData *QueuedRData; mDNSu16 QueuedRDLen; // if the client call Update while an update is in flight, we must finish the
1584 // pending operation (re-transmitting if necessary) THEN register the queued update
1585 mDNSRecordUpdateCallback *UpdateRDCallback; // client callback to free old rdata
1586 } uDNS_RegInfo;
1587
1588 struct AuthRecord_struct
1589 {
1590 // For examples of how to set up this structure for use in mDNS_Register(),
1591 // see mDNS_AdvertiseInterface() or mDNS_RegisterService().
1592 // Basically, resrec and persistent metadata need to be set up before calling mDNS_Register().
1593 // mDNS_SetupResourceRecord() is avaliable as a helper routine to set up most fields to sensible default values for you
1594
1595 AuthRecord *next; // Next in list; first element of structure for efficiency reasons
1596 // Field Group 1: Common ResourceRecord fields
1597 ResourceRecord resrec;
1598 uDNS_RegInfo uDNS_info;
1599
1600 // Field Group 2: Persistent metadata for Authoritative Records
1601 AuthRecord *Additional1; // Recommended additional record to include in response
1602 AuthRecord *Additional2; // Another additional
1603 AuthRecord *DependentOn; // This record depends on another for its uniqueness checking
1604 AuthRecord *RRSet; // This unique record is part of an RRSet
1605 mDNSRecordCallback *RecordCallback; // Callback function to call for state changes, and to free memory asynchronously on deregistration
1606 void *RecordContext; // Context parameter for the callback function
1607 mDNSu8 HostTarget; // Set if the target of this record (PTR, CNAME, SRV, etc.) is our host name
1608 mDNSu8 AllowRemoteQuery; // Set if we allow hosts not on the local link to query this record
1609 mDNSu8 ForceMCast; // Set by client to advertise solely via multicast, even for apparently unicast names
1610
1611 // Field Group 3: Transient state for Authoritative Records
1612 mDNSu8 Acknowledged; // Set if we've given the success callback to the client
1613 mDNSu8 ProbeCount; // Number of probes remaining before this record is valid (kDNSRecordTypeUnique)
1614 mDNSu8 AnnounceCount; // Number of announcements remaining (kDNSRecordTypeShared)
1615 mDNSu8 RequireGoodbye; // Set if this RR has been announced on the wire and will require a goodbye packet
1616 mDNSu8 LocalAnswer; // Set if this RR has been delivered to LocalOnly questions
1617 mDNSu8 IncludeInProbe; // Set if this RR is being put into a probe right now
1618 mDNSInterfaceID ImmedAnswer; // Someone on this interface issued a query we need to answer (all-ones for all interfaces)
1619 mDNSu8 ImmedUnicast; // Set if we may send our response directly via unicast to the requester
1620 #if MDNS_LOG_ANSWER_SUPPRESSION_TIMES
1621 mDNSs32 ImmedAnswerMarkTime;
1622 #endif
1623 mDNSInterfaceID ImmedAdditional; // Hint that we might want to also send this record, just to be helpful
1624 mDNSInterfaceID SendRNow; // The interface this query is being sent on right now
1625 mDNSv4Addr v4Requester; // Recent v4 query for this record, or all-ones if more than one recent query
1626 mDNSv6Addr v6Requester; // Recent v6 query for this record, or all-ones if more than one recent query
1627 AuthRecord *NextResponse; // Link to the next element in the chain of responses to generate
1628 const mDNSu8 *NR_AnswerTo; // Set if this record was selected by virtue of being a direct answer to a question
1629 AuthRecord *NR_AdditionalTo; // Set if this record was selected by virtue of being additional to another
1630 mDNSs32 ThisAPInterval; // In platform time units: Current interval for announce/probe
1631 mDNSs32 AnnounceUntil; // In platform time units: Creation time + TTL
1632 mDNSs32 LastAPTime; // In platform time units: Last time we sent announcement/probe
1633 mDNSs32 LastMCTime; // Last time we multicast this record (used to guard against packet-storm attacks)
1634 mDNSInterfaceID LastMCInterface; // Interface this record was multicast on at the time LastMCTime was recorded
1635 RData *NewRData; // Set if we are updating this record with new rdata
1636 mDNSu16 newrdlength; // ... and the length of the new RData
1637 mDNSRecordUpdateCallback *UpdateCallback;
1638 mDNSu32 UpdateCredits; // Token-bucket rate limiting of excessive updates
1639 mDNSs32 NextUpdateCredit; // Time next token is added to bucket
1640 mDNSs32 UpdateBlocked; // Set if update delaying is in effect
1641
1642 domainname namestorage;
1643 RData rdatastorage; // Normally the storage is right here, except for oversized records
1644 // rdatastorage MUST be the last thing in the structure -- when using oversized AuthRecords, extra bytes
1645 // are appended after the end of the AuthRecord, logically augmenting the size of the rdatastorage
1646 // DO NOT ADD ANY MORE FIELDS HERE
1647 };
1648
1649 // Wrapper struct for Auth Records for higher-level code that cannot use the AuthRecord's ->next pointer field
1650 typedef struct ARListElem
1651 {
1652 struct ARListElem *next;
1653 AuthRecord ar; // Note: Must be last struct in field to accomodate oversized AuthRecords
1654 } ARListElem;
1655
1656 struct CacheGroup_struct // Header object for a list of CacheRecords with the same name
1657 {
1658 CacheGroup *next; // Next CacheGroup object in this hash table bucket
1659 mDNSu32 namehash; // Name-based (i.e. case insensitive) hash of name
1660 CacheRecord *members; // List of CacheRecords with this same name
1661 CacheRecord **rrcache_tail; // Tail end of that list
1662 domainname *name; // Common name for all CacheRecords in this list
1663 mDNSu8 namestorage[InlineCacheGroupNameSize];
1664 };
1665
1666 struct CacheRecord_struct
1667 {
1668 CacheRecord *next; // Next in list; first element of structure for efficiency reasons
1669 ResourceRecord resrec;
1670
1671 // Transient state for Cache Records
1672 CacheRecord *NextInKAList; // Link to the next element in the chain of known answers to send
1673 mDNSs32 TimeRcvd; // In platform time units
1674 mDNSs32 DelayDelivery; // Set if we want to defer delivery of this answer to local clients
1675 mDNSs32 NextRequiredQuery; // In platform time units
1676 mDNSs32 LastUsed; // In platform time units
1677 DNSQuestion *CRActiveQuestion; // Points to an active question referencing this answer
1678 mDNSu32 UnansweredQueries; // Number of times we've issued a query for this record without getting an answer
1679 mDNSs32 LastUnansweredTime; // In platform time units; last time we incremented UnansweredQueries
1680 mDNSu32 MPUnansweredQ; // Multi-packet query handling: Number of times we've seen a query for this record
1681 mDNSs32 MPLastUnansweredQT; // Multi-packet query handling: Last time we incremented MPUnansweredQ
1682 mDNSu32 MPUnansweredKA; // Multi-packet query handling: Number of times we've seen this record in a KA list
1683 mDNSBool MPExpectingKA; // Multi-packet query handling: Set when we increment MPUnansweredQ; allows one KA
1684 CacheRecord *NextInCFList; // Set if this is in the list of records we just received with the cache flush bit set
1685
1686 struct { mDNSu16 MaxRDLength; mDNSu8 data[InlineCacheRDSize]; } rdatastorage; // Storage for small records is right here
1687 };
1688
1689 // Storage sufficient to hold either a CacheGroup header or a CacheRecord
1690 typedef union CacheEntity_union CacheEntity;
1691 union CacheEntity_union { CacheEntity *next; CacheGroup cg; CacheRecord cr; };
1692
1693 typedef struct
1694 {
1695 CacheRecord r;
1696 mDNSu8 _extradata[MaximumRDSize-InlineCacheRDSize]; // Glue on the necessary number of extra bytes
1697 domainname namestorage; // Needs to go *after* the extra rdata bytes
1698 } LargeCacheRecord;
1699
1700 typedef struct uDNS_HostnameInfo
1701 {
1702 struct uDNS_HostnameInfo *next;
1703 domainname fqdn;
1704 AuthRecord *arv4; // registered IPv4 address record
1705 AuthRecord *arv6; // registered IPv6 address record
1706 mDNSRecordCallback *StatusCallback; // callback to deliver success or error code to client layer
1707 const void *StatusContext; // Client Context
1708 } uDNS_HostnameInfo;
1709
1710 enum
1711 {
1712 DNSServer_Untested = 0,
1713 DNSServer_Failed = 1,
1714 DNSServer_Passed = 2
1715 };
1716
1717 typedef struct DNSServer
1718 {
1719 struct DNSServer *next;
1720 mDNSAddr addr;
1721 mDNSBool del; // Set when we're planning to delete this from the list
1722 mDNSu32 teststate; // Have we sent bug-detection query to this server?
1723 domainname domain; // name->server matching for "split dns"
1724 } DNSServer;
1725
1726 typedef struct NetworkInterfaceInfo_struct NetworkInterfaceInfo;
1727
1728 // A NetworkInterfaceInfo_struct serves two purposes:
1729 // 1. It holds the address, PTR and HINFO records to advertise a given IP address on a given physical interface
1730 // 2. It tells mDNSCore which physical interfaces are available; each physical interface has its own unique InterfaceID.
1731 // Since there may be multiple IP addresses on a single physical interface,
1732 // there may be multiple NetworkInterfaceInfo_structs with the same InterfaceID.
1733 // In this case, to avoid sending the same packet n times, when there's more than one
1734 // struct with the same InterfaceID, mDNSCore picks one member of the set to be the
1735 // active representative of the set; all others have the 'InterfaceActive' flag unset.
1736
1737 struct NetworkInterfaceInfo_struct
1738 {
1739 // Internal state fields. These are used internally by mDNSCore; the client layer needn't be concerned with them.
1740 NetworkInterfaceInfo *next;
1741
1742 mDNSBool InterfaceActive; // Set if interface is sending & receiving packets (see comment above)
1743 mDNSBool IPv4Available; // If InterfaceActive, set if v4 available on this InterfaceID
1744 mDNSBool IPv6Available; // If InterfaceActive, set if v6 available on this InterfaceID
1745
1746 // Standard AuthRecords that every Responder host should have (one per active IP address)
1747 AuthRecord RR_A; // 'A' or 'AAAA' (address) record for our ".local" name
1748 AuthRecord RR_PTR; // PTR (reverse lookup) record
1749 AuthRecord RR_HINFO;
1750
1751 // Client API fields: The client must set up these fields *before* calling mDNS_RegisterInterface()
1752 mDNSInterfaceID InterfaceID; // Identifies physical interface; MUST NOT be 0, -1, or -2
1753 mDNSAddr ip; // The IPv4 or IPv6 address to advertise
1754 mDNSAddr mask;
1755 char ifname[64]; // Windows uses a GUID string for the interface name, which doesn't fit in 16 bytes
1756 mDNSBool Advertise; // False if you are only searching on this interface
1757 mDNSBool McastTxRx; // Send/Receive multicast on this { InterfaceID, address family } ?
1758 };
1759
1760 typedef struct ExtraResourceRecord_struct ExtraResourceRecord;
1761 struct ExtraResourceRecord_struct
1762 {
1763 ExtraResourceRecord *next;
1764 mDNSu32 ClientID; // Opaque ID field to be used by client to map an AddRecord call to a set of Extra records
1765 AuthRecord r;
1766 // Note: Add any additional fields *before* the AuthRecord in this structure, not at the end.
1767 // In some cases clients can allocate larger chunks of memory and set r->rdata->MaxRDLength to indicate
1768 // that this extra memory is available, which would result in any fields after the AuthRecord getting smashed
1769 };
1770
1771 // Note: Within an mDNSServiceCallback mDNS all API calls are legal except mDNS_Init(), mDNS_Close(), mDNS_Execute()
1772 typedef struct ServiceRecordSet_struct ServiceRecordSet;
1773 typedef void mDNSServiceCallback(mDNS *const m, ServiceRecordSet *const sr, mStatus result);
1774 struct ServiceRecordSet_struct
1775 {
1776 // Internal state fields. These are used internally by mDNSCore; the client layer needn't be concerned with them.
1777 // No fields need to be set up by the client prior to calling mDNS_RegisterService();
1778 // all required data is passed as parameters to that function.
1779 ServiceRecordSet *next;
1780 uDNS_RegInfo uDNS_info;
1781 mDNSServiceCallback *ServiceCallback;
1782 void *ServiceContext;
1783 ExtraResourceRecord *Extras; // Optional list of extra AuthRecords attached to this service registration
1784 mDNSu32 NumSubTypes;
1785 AuthRecord *SubTypes;
1786 mDNSBool Conflict; // Set if this record set was forcibly deregistered because of a conflict
1787 domainname Host; // Set if this service record does not use the standard target host name
1788 AuthRecord RR_ADV; // e.g. _services._dns-sd._udp.local. PTR _printer._tcp.local.
1789 AuthRecord RR_PTR; // e.g. _printer._tcp.local. PTR Name._printer._tcp.local.
1790 AuthRecord RR_SRV; // e.g. Name._printer._tcp.local. SRV 0 0 port target
1791 AuthRecord RR_TXT; // e.g. Name._printer._tcp.local. TXT PrintQueueName
1792 // Don't add any fields after AuthRecord RR_TXT.
1793 // This is where the implicit extra space goes if we allocate a ServiceRecordSet containing an oversized RR_TXT record
1794 };
1795
1796 // ***************************************************************************
1797 #if 0
1798 #pragma mark - Question structures
1799 #endif
1800
1801 // We record the last eight instances of each duplicate query
1802 // This gives us v4/v6 on each of Ethernet/AirPort and Firewire, and two free slots "for future expansion"
1803 // If the host has more active interfaces that this it is not fatal -- duplicate question suppression will degrade gracefully.
1804 // Since we will still remember the last eight, the busiest interfaces will still get the effective duplicate question suppression.
1805 #define DupSuppressInfoSize 8
1806
1807 typedef struct
1808 {
1809 mDNSs32 Time;
1810 mDNSInterfaceID InterfaceID;
1811 mDNSs32 Type; // v4 or v6?
1812 } DupSuppressInfo;
1813
1814 typedef enum
1815 {
1816 // Setup states
1817 LLQ_UnInit = 0,
1818 LLQ_GetZoneInfo = 1,
1819 LLQ_InitialRequest = 2,
1820 LLQ_SecondaryRequest = 3,
1821 LLQ_Refresh = 4,
1822 LLQ_Retry = 5,
1823 LLQ_Established = 6,
1824 LLQ_Suspended = 7,
1825 LLQ_SuspendDeferred = 8, // suspend once we get zone info
1826 LLQ_SuspendedPoll = 9, // suspended from polling state
1827 LLQ_NatMapWait = 10,
1828
1829 // Established/error states
1830 LLQ_Static = 16,
1831 LLQ_Poll = 17,
1832 LLQ_Error = 18,
1833 LLQ_Cancelled = 19
1834 } LLQ_State;
1835
1836 typedef struct
1837 {
1838 LLQ_State state;
1839 mDNSAddr servAddr;
1840 mDNSIPPort servPort;
1841 DNSQuestion *question;
1842 mDNSu32 origLease; // seconds (relative)
1843 mDNSs32 retry; // ticks (absolute)
1844 mDNSs32 expire; // ticks (absolute)
1845 mDNSs16 ntries;
1846 mDNSu8 id[8];
1847 mDNSBool deriveRemovesOnResume;
1848 mDNSBool NATMap; // does this LLQ use the global LLQ NAT mapping?
1849 } LLQ_Info;
1850
1851 // LLQ constants
1852 #define kDNSOpt_LLQ 1
1853 #define kDNSOpt_Lease 2
1854 #define kLLQ_Vers 1
1855 #define kLLQ_DefLease 7200 // 2 hours
1856 #define kLLQ_MAX_TRIES 3 // retry an operation 3 times max
1857 #define kLLQ_INIT_RESEND 2 // resend an un-ack'd packet after 2 seconds, then double for each additional
1858 #define kLLQ_DEF_RETRY 1800 // retry a failed operation after 30 minutes
1859 // LLQ Operation Codes
1860 #define kLLQOp_Setup 1
1861 #define kLLQOp_Refresh 2
1862 #define kLLQOp_Event 3
1863
1864 #define LLQ_OPT_RDLEN ((2 * sizeof(mDNSu16)) + LLQ_OPTLEN)
1865 #define LEASE_OPT_RDLEN (2 * sizeof(mDNSu16)) + sizeof(mDNSs32)
1866
1867 // LLQ Errror Codes
1868 enum
1869 {
1870 LLQErr_NoError = 0,
1871 LLQErr_ServFull = 1,
1872 LLQErr_Static = 2,
1873 LLQErr_FormErr = 3,
1874 LLQErr_NoSuchLLQ = 4,
1875 LLQErr_BadVers = 5,
1876 LLQErr_UnknownErr = 6
1877 };
1878
1879 typedef void (*InternalResponseHndlr)(mDNS *const m, DNSMessage *msg, const mDNSu8 *end, DNSQuestion *question, void *internalContext);
1880 typedef struct
1881 {
1882 mDNSOpaque16 id;
1883 mDNSBool internal;
1884 InternalResponseHndlr responseCallback; // NULL if internal field is false
1885 LLQ_Info *llq; // NULL for 1-shot queries
1886 mDNSBool Answered; // have we received an answer (including NXDOMAIN) for this question?
1887 CacheRecord *knownAnswers;
1888 mDNSs32 RestartTime; // Mark when we restart a suspended query
1889 void *context;
1890 } uDNS_QuestionInfo;
1891
1892 // Note: Within an mDNSQuestionCallback mDNS all API calls are legal except mDNS_Init(), mDNS_Close(), mDNS_Execute()
1893 typedef void mDNSQuestionCallback(mDNS *const m, DNSQuestion *question, const ResourceRecord *const answer, mDNSBool AddRecord);
1894 struct DNSQuestion_struct
1895 {
1896 // Internal state fields. These are used internally by mDNSCore; the client layer needn't be concerned with them.
1897 DNSQuestion *next;
1898 mDNSu32 qnamehash;
1899 mDNSs32 DelayAnswering; // Set if we want to defer answering this question until the cache settles
1900 mDNSs32 LastQTime; // Last scheduled transmission of this Q on *all* applicable interfaces
1901 mDNSs32 ThisQInterval; // LastQTime + ThisQInterval is the next scheduled transmission of this Q
1902 // ThisQInterval > 0 for an active question;
1903 // ThisQInterval = 0 for a suspended question that's still in the list
1904 // ThisQInterval = -1 for a cancelled question that's been removed from the list
1905 mDNSs32 LastAnswerPktNum; // The sequence number of the last response packet containing an answer to this Q
1906 mDNSu32 RecentAnswerPkts; // Number of answers since the last time we sent this query
1907 mDNSu32 CurrentAnswers; // Number of records currently in the cache that answer this question
1908 mDNSu32 LargeAnswers; // Number of answers with rdata > 1024 bytes
1909 mDNSu32 UniqueAnswers; // Number of answers received with kDNSClass_UniqueRRSet bit set
1910 mDNSInterfaceID FlappingInterface;// Set when an interface goes away, to flag if removes are delivered for this Q
1911 DNSQuestion *DuplicateOf;
1912 DNSQuestion *NextInDQList;
1913 DupSuppressInfo DupSuppress[DupSuppressInfoSize];
1914 mDNSInterfaceID SendQNow; // The interface this query is being sent on right now
1915 mDNSBool SendOnAll; // Set if we're sending this question on all active interfaces
1916 mDNSu32 RequestUnicast; // Non-zero if we want to send query with kDNSQClass_UnicastResponse bit set
1917 mDNSs32 LastQTxTime; // Last time this Q was sent on one (but not necessarily all) interfaces
1918 uDNS_QuestionInfo uDNS_info;
1919
1920 // Client API fields: The client must set up these fields *before* calling mDNS_StartQuery()
1921 mDNSInterfaceID InterfaceID; // Non-zero if you want to issue queries only on a single specific IP interface
1922 mDNSAddr Target; // Non-zero if you want to direct queries to a specific unicast target address
1923 mDNSIPPort TargetPort; // Must be set if Target is set
1924 mDNSOpaque16 TargetQID; // Must be set if Target is set
1925 domainname qname;
1926 mDNSu16 qtype;
1927 mDNSu16 qclass;
1928 mDNSBool LongLived; // Set by client for calls to mDNS_StartQuery to indicate LLQs to unicast layer.
1929 mDNSBool ExpectUnique; // Set by client if it's expecting unique RR(s) for this question, not shared RRs
1930 mDNSBool ForceMCast; // Set by client to force mDNS query, even for apparently uDNS names
1931 mDNSBool ReturnCNAME; // Set by client to request callbacks for intermediate CNAME records
1932 mDNSQuestionCallback *QuestionCallback;
1933 void *QuestionContext;
1934 };
1935
1936 typedef struct
1937 {
1938 // Client API fields: The client must set up name and InterfaceID *before* calling mDNS_StartResolveService()
1939 // When the callback is invoked, ip, port, TXTlen and TXTinfo will have been filled in with the results learned from the network.
1940 domainname name;
1941 mDNSInterfaceID InterfaceID; // ID of the interface the response was received on
1942 mDNSAddr ip; // Remote (destination) IP address where this service can be accessed
1943 mDNSIPPort port; // Port where this service can be accessed
1944 mDNSu16 TXTlen;
1945 mDNSu8 TXTinfo[2048]; // Additional demultiplexing information (e.g. LPR queue name)
1946 } ServiceInfo;
1947
1948 // Note: Within an mDNSServiceInfoQueryCallback mDNS all API calls are legal except mDNS_Init(), mDNS_Close(), mDNS_Execute()
1949 typedef struct ServiceInfoQuery_struct ServiceInfoQuery;
1950 typedef void mDNSServiceInfoQueryCallback(mDNS *const m, ServiceInfoQuery *query);
1951 struct ServiceInfoQuery_struct
1952 {
1953 // Internal state fields. These are used internally by mDNSCore; the client layer needn't be concerned with them.
1954 // No fields need to be set up by the client prior to calling mDNS_StartResolveService();
1955 // all required data is passed as parameters to that function.
1956 // The ServiceInfoQuery structure memory is working storage for mDNSCore to discover the requested information
1957 // and place it in the ServiceInfo structure. After the client has called mDNS_StopResolveService(), it may
1958 // dispose of the ServiceInfoQuery structure while retaining the results in the ServiceInfo structure.
1959 DNSQuestion qSRV;
1960 DNSQuestion qTXT;
1961 DNSQuestion qAv4;
1962 DNSQuestion qAv6;
1963 mDNSu8 GotSRV;
1964 mDNSu8 GotTXT;
1965 mDNSu8 GotADD;
1966 mDNSu32 Answers;
1967 ServiceInfo *info;
1968 mDNSServiceInfoQueryCallback *ServiceInfoQueryCallback;
1969 void *ServiceInfoQueryContext;
1970 };
1971
1972 // ***************************************************************************
1973 #if 0
1974 #pragma mark - NAT Traversal structures and constants
1975 #endif
1976
1977 #define NATMAP_INIT_RETRY (mDNSPlatformOneSecond / 4) // start at 250ms w/ exponential decay
1978 #define NATMAP_MAX_RETRY mDNSPlatformOneSecond // back off to once per second
1979 #define NATMAP_MAX_TRIES 3 // for max 3 tries
1980 #define NATMAP_DEFAULT_LEASE (60 * 60) // lease life in seconds
1981 #define NATMAP_VERS 0
1982 #define NATMAP_RESPONSE_MASK 0x80
1983
1984 typedef enum
1985 {
1986 NATOp_AddrRequest = 0,
1987 NATOp_MapUDP = 1,
1988 NATOp_MapTCP = 2
1989 } NATOp_t;
1990
1991 enum
1992 {
1993 NATErr_None = 0,
1994 NATErr_Vers = 1,
1995 NATErr_Refused = 2,
1996 NATErr_NetFail = 3,
1997 NATErr_Res = 4,
1998 NATErr_Opcode = 5
1999 };
2000
2001 typedef mDNSu16 NATErr_t;
2002
2003 typedef enum
2004 {
2005 NATState_Init = 0,
2006 NATState_Request = 1,
2007 NATState_Established = 2,
2008 NATState_Legacy = 3,
2009 NATState_Error = 4,
2010 NATState_Refresh = 5,
2011 NATState_Deleted = 6
2012 } NATState_t;
2013 // Note: we have no explicit "cancelled" state, where a service/interface is deregistered while we
2014 // have an outstanding NAT request. This is conveyed by the "reg" pointer being set to NULL
2015
2016 typedef packedstruct
2017 {
2018 mDNSu8 vers;
2019 mDNSu8 opcode;
2020 } NATAddrRequest;
2021
2022 typedef packedstruct
2023 {
2024 mDNSu8 vers;
2025 mDNSu8 opcode;
2026 mDNSOpaque16 err;
2027 mDNSOpaque32 uptime;
2028 mDNSv4Addr PubAddr;
2029 } NATAddrReply;
2030
2031 typedef packedstruct
2032 {
2033 mDNSu8 vers;
2034 mDNSu8 opcode;
2035 mDNSOpaque16 unused;
2036 mDNSIPPort priv;
2037 mDNSIPPort pub;
2038 mDNSOpaque32 lease;
2039 } NATPortMapRequest;
2040
2041 typedef packedstruct
2042 {
2043 mDNSu8 vers;
2044 mDNSu8 opcode;
2045 mDNSOpaque16 err;
2046 mDNSOpaque32 uptime;
2047 mDNSIPPort priv;
2048 mDNSIPPort pub;
2049 mDNSOpaque32 lease;
2050 } NATPortMapReply;
2051
2052 // Pass NULL for pkt on error (including timeout)
2053 typedef mDNSBool (*NATResponseHndlr)(NATTraversalInfo *n, mDNS *m, mDNSu8 *pkt, mDNSu16 len);
2054
2055 struct NATTraversalInfo_struct
2056 {
2057 NATOp_t op;
2058 NATResponseHndlr ReceiveResponse;
2059 union { AuthRecord *RecordRegistration; ServiceRecordSet *ServiceRegistration; } reg;
2060 mDNSAddr Router;
2061 mDNSIPPort PublicPort;
2062 union { NATAddrRequest AddrReq; NATPortMapRequest PortReq; } request;
2063 mDNSs32 retry; // absolute time when we retry
2064 mDNSs32 RetryInterval; // delta between time sent and retry
2065 int ntries;
2066 NATState_t state;
2067 NATTraversalInfo *next;
2068 };
2069
2070 // ***************************************************************************
2071 #if 0
2072 #pragma mark - Main mDNS object, used to hold all the mDNS state
2073 #endif
2074
2075 typedef void mDNSCallback(mDNS *const m, mStatus result);
2076
2077 #define CACHE_HASH_SLOTS 499
2078
2079 enum
2080 {
2081 mDNS_KnownBug_PhantomInterfaces = 1
2082 };
2083
2084 typedef struct
2085 {
2086 mDNSs32 nextevent;
2087 DNSQuestion *ActiveQueries; //!!!KRS this should be a hashtable (hash on messageID)
2088 DNSQuestion *CurrentQuery; // pointer to ActiveQueries list being examined in a loop. Functions that remove
2089 // elements from the ActiveQueries list must update this pointer (if non-NULL) as necessary.
2090 //!!!KRS do the same for registration lists
2091 ServiceRecordSet *ServiceRegistrations;
2092 AuthRecord *RecordRegistrations;
2093 NATTraversalInfo *NATTraversals;
2094 mDNSu16 NextMessageID;
2095 DNSServer *Servers; // list of DNS servers
2096 mDNSAddr Router;
2097 mDNSAddr AdvertisedV4; // IPv4 address pointed to by hostname
2098 mDNSAddr MappedV4; // Cache of public address if PrimaryIP is behind a NAT
2099 mDNSAddr AdvertisedV6; // IPv6 address pointed to by hostname
2100 NATTraversalInfo *LLQNatInfo; // Nat port mapping to receive LLQ events
2101 domainname ServiceRegDomain; // (going away w/ multi-user support)
2102 struct uDNS_AuthInfo *AuthInfoList; // list of domains requiring authentication for updates.
2103 uDNS_HostnameInfo *Hostnames; // List of registered hostnames + hostname metadata
2104 DNSQuestion ReverseMap; // Reverse-map query to find static hostname for service target
2105 mDNSBool ReverseMapActive; // Is above query active?
2106 domainname StaticHostname; // Current answer to reverse-map query (above)
2107 mDNSBool DelaySRVUpdate; // Delay SRV target/port update to avoid "flap"
2108 mDNSs32 NextSRVUpdate; // Time to perform delayed update
2109 } uDNS_GlobalInfo;
2110
2111 struct mDNS_struct
2112 {
2113 // Internal state fields. These hold the main internal state of mDNSCore;
2114 // the client layer needn't be concerned with them.
2115 // No fields need to be set up by the client prior to calling mDNS_Init();
2116 // all required data is passed as parameters to that function.
2117
2118 mDNS_PlatformSupport *p; // Pointer to platform-specific data of indeterminite size
2119 mDNSu32 KnownBugs;
2120 mDNSBool CanReceiveUnicastOn5353;
2121 mDNSBool AdvertiseLocalAddresses;
2122 mStatus mDNSPlatformStatus;
2123 mDNSIPPort UnicastPort4;
2124 mDNSIPPort UnicastPort6;
2125 mDNSCallback *MainCallback;
2126 void *MainContext;
2127
2128 // For debugging: To catch and report locking failures
2129 mDNSu32 mDNS_busy; // Incremented between mDNS_Lock/mDNS_Unlock section
2130 mDNSu32 mDNS_reentrancy; // Incremented when calling a client callback
2131 mDNSu8 mDNS_shutdown; // Set when we're shutting down, allows us to skip some unnecessary steps
2132 mDNSu8 lock_rrcache; // For debugging: Set at times when these lists may not be modified
2133 mDNSu8 lock_Questions;
2134 mDNSu8 lock_Records;
2135 #define MaxMsg 120
2136 char MsgBuffer[MaxMsg]; // Temp storage used while building error log messages
2137
2138 // Task Scheduling variables
2139 mDNSs32 timenow_adjust; // Correction applied if we ever discover time went backwards
2140 mDNSs32 timenow; // The time that this particular activation of the mDNS code started
2141 mDNSs32 timenow_last; // The time the last time we ran
2142 mDNSs32 NextScheduledEvent; // Derived from values below
2143 mDNSs32 SuppressSending; // Don't send *any* packets during this time
2144 mDNSs32 NextCacheCheck; // Next time to refresh cache record before it expires
2145 mDNSs32 NextScheduledQuery; // Next time to send query in its exponential backoff sequence
2146 mDNSs32 NextScheduledProbe; // Next time to probe for new authoritative record
2147 mDNSs32 NextScheduledResponse; // Next time to send authoritative record(s) in responses
2148 mDNSs32 ExpectUnicastResponse; // Set when we send a query with the kDNSQClass_UnicastResponse bit set
2149 mDNSs32 RandomQueryDelay; // For de-synchronization of query packets on the wire
2150 mDNSu32 RandomReconfirmDelay; // For de-synchronization of reconfirmation queries on the wire
2151 mDNSs32 PktNum; // Unique sequence number assigned to each received packet
2152 mDNSBool SendDeregistrations; // Set if we need to send deregistrations (immediately)
2153 mDNSBool SendImmediateAnswers; // Set if we need to send answers (immediately -- or as soon as SuppressSending clears)
2154 mDNSBool SleepState; // Set if we're sleeping (send no more packets)
2155
2156 // These fields only required for mDNS Searcher...
2157 DNSQuestion *Questions; // List of all registered questions, active and inactive
2158 DNSQuestion *NewQuestions; // Fresh questions not yet answered from cache
2159 DNSQuestion *CurrentQuestion; // Next question about to be examined in AnswerLocalQuestions()
2160 DNSQuestion *LocalOnlyQuestions; // Questions with InterfaceID set to mDNSInterface_LocalOnly
2161 DNSQuestion *NewLocalOnlyQuestions; // Fresh local-only questions not yet answered
2162 mDNSu32 rrcache_size; // Total number of available cache entries
2163 mDNSu32 rrcache_totalused; // Number of cache entries currently occupied
2164 mDNSu32 rrcache_active; // Number of cache entries currently occupied by records that answer active questions
2165 mDNSu32 rrcache_report;
2166 CacheEntity *rrcache_free;
2167 CacheGroup *rrcache_hash[CACHE_HASH_SLOTS];
2168
2169 // Fields below only required for mDNS Responder...
2170 domainlabel nicelabel; // Rich text label encoded using canonically precomposed UTF-8
2171 domainlabel hostlabel; // Conforms to RFC 1034 "letter-digit-hyphen" ARPANET host name rules
2172 domainname MulticastHostname; // Fully Qualified "dot-local" Host Name, e.g. "Foo.local."
2173 UTF8str255 HIHardware;
2174 UTF8str255 HISoftware;
2175 AuthRecord *ResourceRecords;
2176 AuthRecord *DuplicateRecords; // Records currently 'on hold' because they are duplicates of existing records
2177 AuthRecord *NewLocalRecords; // Fresh local-only records not yet delivered to local-only questions
2178 AuthRecord *CurrentRecord; // Next AuthRecord about to be examined
2179 NetworkInterfaceInfo *HostInterfaces;
2180 mDNSs32 ProbeFailTime;
2181 mDNSu32 NumFailedProbes;
2182 mDNSs32 SuppressProbes;
2183
2184 // unicast-specific data
2185 uDNS_GlobalInfo uDNS_info;
2186 mDNSs32 SuppressStdPort53Queries; // Wait before allowing the next standard unicast query to the user's configured DNS server
2187
2188 // Fixed storage, to avoid creating large objects on the stack
2189 DNSMessage imsg; // Incoming message received from wire
2190 DNSMessage omsg; // Outgoing message we're building
2191 LargeCacheRecord rec; // Resource Record extracted from received message
2192 };
2193
2194 #define FORALL_CACHERECORDS(SLOT,CG,CR) \
2195 for ((SLOT) = 0; (SLOT) < CACHE_HASH_SLOTS; (SLOT)++) \
2196 for((CG)=m->rrcache_hash[(SLOT)]; (CG); (CG)=(CG)->next) \
2197 for ((CR) = (CG)->members; (CR); (CR)=(CR)->next)
2198
2199 // ***************************************************************************
2200 #if 0
2201 #pragma mark - Useful Static Constants
2202 #endif
2203
2204 extern const mDNSIPPort zeroIPPort;
2205 extern const mDNSv4Addr zerov4Addr;
2206 extern const mDNSv6Addr zerov6Addr;
2207 extern const mDNSEthAddr zeroEthAddr;
2208 extern const mDNSv4Addr onesIPv4Addr;
2209 extern const mDNSv6Addr onesIPv6Addr;
2210 extern const mDNSAddr zeroAddr;
2211
2212 extern const mDNSInterfaceID mDNSInterface_Any; // Zero
2213 extern const mDNSInterfaceID mDNSInterface_LocalOnly; // Special value
2214
2215 extern const mDNSIPPort UnicastDNSPort;
2216 extern const mDNSIPPort NATPMPPort;
2217 extern const mDNSIPPort DNSEXTPort;
2218 extern const mDNSIPPort MulticastDNSPort;
2219 extern const mDNSIPPort LoopbackIPCPort;
2220
2221 extern const mDNSv4Addr AllDNSAdminGroup;
2222 #define AllDNSLinkGroupv4 (AllDNSLinkGroup_v4.ip.v4)
2223 #define AllDNSLinkGroupv6 (AllDNSLinkGroup_v6.ip.v6)
2224 extern const mDNSAddr AllDNSLinkGroup_v4;
2225 extern const mDNSAddr AllDNSLinkGroup_v6;
2226
2227 extern const mDNSOpaque16 zeroID;
2228 extern const mDNSOpaque16 QueryFlags;
2229 extern const mDNSOpaque16 uQueryFlags;
2230 extern const mDNSOpaque16 ResponseFlags;
2231 extern const mDNSOpaque16 UpdateReqFlags;
2232 extern const mDNSOpaque16 UpdateRespFlags;
2233
2234 #define localdomain (*(const domainname *)"\x5" "local")
2235 #define LocalReverseMapDomain (*(const domainname *)"\x3" "254" "\x3" "169" "\x7" "in-addr" "\x4" "arpa")
2236
2237 // ***************************************************************************
2238 #if 0
2239 #pragma mark - Inline functions
2240 #endif
2241
2242 #if (defined(_MSC_VER))
2243 #define mDNSinline static __inline
2244 #elif ((__GNUC__ > 2) || ((__GNUC__ == 2) && (__GNUC_MINOR__ >= 9)))
2245 #define mDNSinline static inline
2246 #endif
2247
2248 // If we're not doing inline functions, then this header needs to have the extern declarations
2249 #if !defined(mDNSinline)
2250 extern mDNSs32 NonZeroTime(mDNSs32 t);
2251 extern mDNSu16 mDNSVal16(mDNSOpaque16 x);
2252 extern mDNSu32 mDNSVal32(mDNSOpaque32 x);
2253 extern mDNSOpaque16 mDNSOpaque16fromIntVal(mDNSu16 v);
2254 extern mDNSOpaque32 mDNSOpaque32fromIntVal(mDNSu32 v);
2255 #endif
2256
2257 // If we're compiling the particular C file that instantiates our inlines, then we
2258 // define "mDNSinline" (to empty string) so that we generate code in the following section
2259 #if (!defined(mDNSinline) && mDNS_InstantiateInlines)
2260 #define mDNSinline
2261 #endif
2262
2263 #ifdef mDNSinline
2264
NonZeroTime(mDNSs32 t)2265 mDNSinline mDNSs32 NonZeroTime(mDNSs32 t) { if (t) return(t); else return(1); }
2266
mDNSVal16(mDNSOpaque16 x)2267 mDNSinline mDNSu16 mDNSVal16(mDNSOpaque16 x) { return((mDNSu16)((mDNSu16)x.b[0] << 8 | (mDNSu16)x.b[1])); }
mDNSVal32(mDNSOpaque32 x)2268 mDNSinline mDNSu32 mDNSVal32(mDNSOpaque32 x) { return((mDNSu32)((mDNSu32)x.b[0] << 24 | (mDNSu32)x.b[1] << 16 | (mDNSu32)x.b[2] << 8 | (mDNSu32)x.b[3])); }
2269
mDNSOpaque16fromIntVal(mDNSu16 v)2270 mDNSinline mDNSOpaque16 mDNSOpaque16fromIntVal(mDNSu16 v)
2271 {
2272 mDNSOpaque16 x;
2273 x.b[0] = (mDNSu8)(v >> 8);
2274 x.b[1] = (mDNSu8)(v & 0xFF);
2275 return(x);
2276 }
2277
mDNSOpaque32fromIntVal(mDNSu32 v)2278 mDNSinline mDNSOpaque32 mDNSOpaque32fromIntVal(mDNSu32 v)
2279 {
2280 mDNSOpaque32 x;
2281 x.b[0] = (mDNSu8) (v >> 24) ;
2282 x.b[1] = (mDNSu8)((v >> 16) & 0xFF);
2283 x.b[2] = (mDNSu8)((v >> 8 ) & 0xFF);
2284 x.b[3] = (mDNSu8)((v ) & 0xFF);
2285 return x;
2286 }
2287
2288 #endif
2289
2290 // ***************************************************************************
2291 #if 0
2292 #pragma mark - Main Client Functions
2293 #endif
2294
2295 // Every client should call mDNS_Init, passing in storage for the mDNS object and the mDNS_PlatformSupport object.
2296 //
2297 // Clients that are only advertising services should use mDNS_Init_NoCache and mDNS_Init_ZeroCacheSize.
2298 // Clients that plan to perform queries (mDNS_StartQuery, mDNS_StartBrowse, mDNS_StartResolveService, etc.)
2299 // need to provide storage for the resource record cache, or the query calls will return 'mStatus_NoCache'.
2300 // The rrcachestorage parameter is the address of memory for the resource record cache, and
2301 // the rrcachesize parameter is the number of entries in the CacheRecord array passed in.
2302 // (i.e. the size of the cache memory needs to be sizeof(CacheRecord) * rrcachesize).
2303 // OS X 10.3 Panther uses an initial cache size of 64 entries, and then mDNSCore sends an
2304 // mStatus_GrowCache message if it needs more.
2305 //
2306 // Most clients should use mDNS_Init_AdvertiseLocalAddresses. This causes mDNSCore to automatically
2307 // create the correct address records for all the hosts interfaces. If you plan to advertise
2308 // services being offered by the local machine, this is almost always what you want.
2309 // There are two cases where you might use mDNS_Init_DontAdvertiseLocalAddresses:
2310 // 1. A client-only device, that browses for services but doesn't advertise any of its own.
2311 // 2. A proxy-registration service, that advertises services being offered by other machines, and takes
2312 // the appropriate steps to manually create the correct address records for those other machines.
2313 // In principle, a proxy-like registration service could manually create address records for its own machine too,
2314 // but this would be pointless extra effort when using mDNS_Init_AdvertiseLocalAddresses does that for you.
2315 //
2316 // When mDNS has finished setting up the client's callback is called
2317 // A client can also spin and poll the mDNSPlatformStatus field to see when it changes from mStatus_Waiting to mStatus_NoError
2318 //
2319 // Call mDNS_Close to tidy up before exiting
2320 //
2321 // Call mDNS_Register with a completed AuthRecord object to register a resource record
2322 // If the resource record type is kDNSRecordTypeUnique (or kDNSknownunique) then if a conflicting resource record is discovered,
2323 // the resource record's mDNSRecordCallback will be called with error code mStatus_NameConflict. The callback should deregister
2324 // the record, and may then try registering the record again after picking a new name (e.g. by automatically appending a number).
2325 // Following deregistration, the RecordCallback will be called with result mStatus_MemFree to signal that it is safe to deallocate
2326 // the record's storage (memory must be freed asynchronously to allow for goodbye packets and dynamic update deregistration).
2327 //
2328 // Call mDNS_StartQuery to initiate a query. mDNS will proceed to issue Multicast DNS query packets, and any time a response
2329 // is received containing a record which matches the question, the DNSQuestion's mDNSAnswerCallback function will be called
2330 // Call mDNS_StopQuery when no more answers are required
2331 //
2332 // Care should be taken on multi-threaded or interrupt-driven environments.
2333 // The main mDNS routines call mDNSPlatformLock() on entry and mDNSPlatformUnlock() on exit;
2334 // each platform layer needs to implement these appropriately for its respective platform.
2335 // For example, if the support code on a particular platform implements timer callbacks at interrupt time, then
2336 // mDNSPlatformLock/Unlock need to disable interrupts or do similar concurrency control to ensure that the mDNS
2337 // code is not entered by an interrupt-time timer callback while in the middle of processing a client call.
2338
2339 extern mStatus mDNS_Init (mDNS *const m, mDNS_PlatformSupport *const p,
2340 CacheEntity *rrcachestorage, mDNSu32 rrcachesize,
2341 mDNSBool AdvertiseLocalAddresses,
2342 mDNSCallback *Callback, void *Context);
2343 // See notes above on use of NoCache/ZeroCacheSize
2344 #define mDNS_Init_NoCache mDNSNULL
2345 #define mDNS_Init_ZeroCacheSize 0
2346 // See notes above on use of Advertise/DontAdvertiseLocalAddresses
2347 #define mDNS_Init_AdvertiseLocalAddresses mDNStrue
2348 #define mDNS_Init_DontAdvertiseLocalAddresses mDNSfalse
2349 #define mDNS_Init_NoInitCallback mDNSNULL
2350 #define mDNS_Init_NoInitCallbackContext mDNSNULL
2351
2352 extern void mDNS_GrowCache (mDNS *const m, CacheEntity *storage, mDNSu32 numrecords);
2353 extern void mDNS_Close (mDNS *const m);
2354 extern mDNSs32 mDNS_Execute (mDNS *const m);
2355
2356 extern mStatus mDNS_Register (mDNS *const m, AuthRecord *const rr);
2357 extern mStatus mDNS_Update (mDNS *const m, AuthRecord *const rr, mDNSu32 newttl,
2358 const mDNSu16 newrdlength, RData *const newrdata, mDNSRecordUpdateCallback *Callback);
2359 extern mStatus mDNS_Deregister(mDNS *const m, AuthRecord *const rr);
2360
2361 extern mStatus mDNS_StartQuery(mDNS *const m, DNSQuestion *const question);
2362 extern mStatus mDNS_StopQuery (mDNS *const m, DNSQuestion *const question);
2363 extern mStatus mDNS_Reconfirm (mDNS *const m, CacheRecord *const cacherr);
2364 extern mStatus mDNS_ReconfirmByValue(mDNS *const m, ResourceRecord *const rr);
2365 extern mDNSs32 mDNS_TimeNow(const mDNS *const m);
2366
2367 // ***************************************************************************
2368 #if 0
2369 #pragma mark - Platform support functions that are accessible to the client layer too
2370 #endif
2371
2372 extern mDNSs32 mDNSPlatformOneSecond;
2373
2374 // ***************************************************************************
2375 #if 0
2376 #pragma mark - General utility and helper functions
2377 #endif
2378
2379 // mDNS_RegisterService is a single call to register the set of resource records associated with a given named service.
2380 //
2381 // mDNS_StartResolveService is single call which is equivalent to multiple calls to mDNS_StartQuery,
2382 // to find the IP address, port number, and demultiplexing information for a given named service.
2383 // As with mDNS_StartQuery, it executes asynchronously, and calls the ServiceInfoQueryCallback when the answer is
2384 // found. After the service is resolved, the client should call mDNS_StopResolveService to complete the transaction.
2385 // The client can also call mDNS_StopResolveService at any time to abort the transaction.
2386 //
2387 // mDNS_AddRecordToService adds an additional record to a Service Record Set. This record may be deregistered
2388 // via mDNS_RemoveRecordFromService, or by deregistering the service. mDNS_RemoveRecordFromService is passed a
2389 // callback to free the memory associated with the extra RR when it is safe to do so. The ExtraResourceRecord
2390 // object can be found in the record's context pointer.
2391
2392 // mDNS_GetBrowseDomains is a special case of the mDNS_StartQuery call, where the resulting answers
2393 // are a list of PTR records indicating (in the rdata) domains that are recommended for browsing.
2394 // After getting the list of domains to browse, call mDNS_StopQuery to end the search.
2395 // mDNS_GetDefaultBrowseDomain returns the name of the domain that should be highlighted by default.
2396 //
2397 // mDNS_GetRegistrationDomains and mDNS_GetDefaultRegistrationDomain are the equivalent calls to get the list
2398 // of one or more domains that should be offered to the user as choices for where they may register their service,
2399 // and the default domain in which to register in the case where the user has made no selection.
2400
2401 extern void mDNS_SetupResourceRecord(AuthRecord *rr, RData *RDataStorage, mDNSInterfaceID InterfaceID,
2402 mDNSu16 rrtype, mDNSu32 ttl, mDNSu8 RecordType, mDNSRecordCallback Callback, void *Context);
2403
2404 extern mStatus mDNS_RegisterService (mDNS *const m, ServiceRecordSet *sr,
2405 const domainlabel *const name, const domainname *const type, const domainname *const domain,
2406 const domainname *const host, mDNSIPPort port, const mDNSu8 txtinfo[], mDNSu16 txtlen,
2407 AuthRecord *SubTypes, mDNSu32 NumSubTypes,
2408 const mDNSInterfaceID InterfaceID, mDNSServiceCallback Callback, void *Context);
2409 extern mStatus mDNS_AddRecordToService(mDNS *const m, ServiceRecordSet *sr, ExtraResourceRecord *extra, RData *rdata, mDNSu32 ttl);
2410 extern mStatus mDNS_RemoveRecordFromService(mDNS *const m, ServiceRecordSet *sr, ExtraResourceRecord *extra, mDNSRecordCallback MemFreeCallback, void *Context);
2411 extern mStatus mDNS_RenameAndReregisterService(mDNS *const m, ServiceRecordSet *const sr, const domainlabel *newname);
2412 extern mStatus mDNS_DeregisterService(mDNS *const m, ServiceRecordSet *sr);
2413
2414 extern mStatus mDNS_RegisterNoSuchService(mDNS *const m, AuthRecord *const rr,
2415 const domainlabel *const name, const domainname *const type, const domainname *const domain,
2416 const domainname *const host,
2417 const mDNSInterfaceID InterfaceID, mDNSRecordCallback Callback, void *Context);
2418 #define mDNS_DeregisterNoSuchService mDNS_Deregister
2419
2420 extern mStatus mDNS_StartBrowse(mDNS *const m, DNSQuestion *const question,
2421 const domainname *const srv, const domainname *const domain,
2422 const mDNSInterfaceID InterfaceID, mDNSBool ForceMCast, mDNSQuestionCallback *Callback, void *Context);
2423 #define mDNS_StopBrowse mDNS_StopQuery
2424
2425 extern mStatus mDNS_StartResolveService(mDNS *const m, ServiceInfoQuery *query, ServiceInfo *info, mDNSServiceInfoQueryCallback *Callback, void *Context);
2426 extern void mDNS_StopResolveService (mDNS *const m, ServiceInfoQuery *query);
2427
2428 typedef enum
2429 {
2430 mDNS_DomainTypeBrowse = 0,
2431 mDNS_DomainTypeBrowseDefault = 1,
2432 mDNS_DomainTypeBrowseLegacy = 2,
2433 mDNS_DomainTypeRegistration = 3,
2434 mDNS_DomainTypeRegistrationDefault = 4,
2435
2436 mDNS_DomainTypeMax = 4
2437 } mDNS_DomainType;
2438
2439 extern const char *const mDNS_DomainTypeNames[];
2440
2441 extern mStatus mDNS_GetDomains(mDNS *const m, DNSQuestion *const question, mDNS_DomainType DomainType, const domainname *dom,
2442 const mDNSInterfaceID InterfaceID, mDNSQuestionCallback *Callback, void *Context);
2443 #define mDNS_StopGetDomains mDNS_StopQuery
2444 extern mStatus mDNS_AdvertiseDomains(mDNS *const m, AuthRecord *rr, mDNS_DomainType DomainType, const mDNSInterfaceID InterfaceID, char *domname);
2445 #define mDNS_StopAdvertiseDomains mDNS_Deregister
2446
2447 // ***************************************************************************
2448 #if 0
2449 #pragma mark - DNS name utility functions
2450 #endif
2451
2452 // In order to expose the full capabilities of the DNS protocol (which allows any arbitrary eight-bit values
2453 // in domain name labels, including unlikely characters like ascii nulls and even dots) all the mDNS APIs
2454 // work with DNS's native length-prefixed strings. For convenience in C, the following utility functions
2455 // are provided for converting between C's null-terminated strings and DNS's length-prefixed strings.
2456
2457 // Assignment
2458 // A simple C structure assignment of a domainname can cause a protection fault by accessing unmapped memory,
2459 // because that object is defined to be 256 bytes long, but not all domainname objects are truly the full size.
2460 // This macro uses mDNSPlatformMemCopy() to make sure it only touches the actual bytes that are valid.
2461 #define AssignDomainName(DST, SRC) mDNSPlatformMemCopy((SRC)->c, (DST)->c, DomainNameLength((SRC)))
2462
2463 // Comparison functions
2464 extern mDNSBool SameDomainLabel(const mDNSu8 *a, const mDNSu8 *b);
2465 extern mDNSBool SameDomainName(const domainname *const d1, const domainname *const d2);
2466 extern mDNSBool IsLocalDomain(const domainname *d); // returns true for domains that by default should be looked up using link-local multicast
2467
2468 // Get total length of domain name, in native DNS format, including terminal root label
2469 // (e.g. length of "com." is 5 (length byte, three data bytes, final zero)
2470 extern mDNSu16 DomainNameLength(const domainname *const name);
2471
2472 // Append functions to append one or more labels to an existing native format domain name:
2473 // AppendLiteralLabelString adds a single label from a literal C string, with no escape character interpretation.
2474 // AppendDNSNameString adds zero or more labels from a C string using conventional DNS dots-and-escaping interpretation
2475 // AppendDomainLabel adds a single label from a native format domainlabel
2476 // AppendDomainName adds zero or more labels from a native format domainname
2477 extern mDNSu8 *AppendLiteralLabelString(domainname *const name, const char *cstr);
2478 extern mDNSu8 *AppendDNSNameString (domainname *const name, const char *cstr);
2479 extern mDNSu8 *AppendDomainLabel (domainname *const name, const domainlabel *const label);
2480 extern mDNSu8 *AppendDomainName (domainname *const name, const domainname *const append);
2481
2482 // Convert from null-terminated string to native DNS format:
2483 // The DomainLabel form makes a single label from a literal C string, with no escape character interpretation.
2484 // The DomainName form makes native format domain name from a C string using conventional DNS interpretation:
2485 // dots separate labels, and within each label, '\.' represents a literal dot, '\\' represents a literal
2486 // backslash and backslash with three decimal digits (e.g. \000) represents an arbitrary byte value.
2487 extern mDNSBool MakeDomainLabelFromLiteralString(domainlabel *const label, const char *cstr);
2488 extern mDNSu8 *MakeDomainNameFromDNSNameString (domainname *const name, const char *cstr);
2489
2490 // Convert native format domainlabel or domainname back to C string format
2491 // IMPORTANT:
2492 // When using ConvertDomainLabelToCString, the target buffer must be MAX_ESCAPED_DOMAIN_LABEL (254) bytes long
2493 // to guarantee there will be no buffer overrun. It is only safe to use a buffer shorter than this in rare cases
2494 // where the label is known to be constrained somehow (for example, if the label is known to be either "_tcp" or "_udp").
2495 // Similarly, when using ConvertDomainNameToCString, the target buffer must be MAX_ESCAPED_DOMAIN_NAME (1005) bytes long.
2496 // See definitions of MAX_ESCAPED_DOMAIN_LABEL and MAX_ESCAPED_DOMAIN_NAME for more detailed explanation.
2497 extern char *ConvertDomainLabelToCString_withescape(const domainlabel *const name, char *cstr, char esc);
2498 #define ConvertDomainLabelToCString_unescaped(D,C) ConvertDomainLabelToCString_withescape((D), (C), 0)
2499 #define ConvertDomainLabelToCString(D,C) ConvertDomainLabelToCString_withescape((D), (C), '\\')
2500 extern char *ConvertDomainNameToCString_withescape(const domainname *const name, char *cstr, char esc);
2501 #define ConvertDomainNameToCString_unescaped(D,C) ConvertDomainNameToCString_withescape((D), (C), 0)
2502 #define ConvertDomainNameToCString(D,C) ConvertDomainNameToCString_withescape((D), (C), '\\')
2503
2504 extern void ConvertUTF8PstringToRFC1034HostLabel(const mDNSu8 UTF8Name[], domainlabel *const hostlabel);
2505
2506 extern mDNSu8 *ConstructServiceName(domainname *const fqdn, const domainlabel *name, const domainname *type, const domainname *const domain);
2507 extern mDNSBool DeconstructServiceName(const domainname *const fqdn, domainlabel *const name, domainname *const type, domainname *const domain);
2508
2509 // Note: Some old functions have been replaced by more sensibly-named versions.
2510 // You can uncomment the hash-defines below if you don't want to have to change your source code right away.
2511 // When updating your code, note that (unlike the old versions) *all* the new routines take the target object
2512 // as their first parameter.
2513 //#define ConvertCStringToDomainName(SRC,DST) MakeDomainNameFromDNSNameString((DST),(SRC))
2514 //#define ConvertCStringToDomainLabel(SRC,DST) MakeDomainLabelFromLiteralString((DST),(SRC))
2515 //#define AppendStringLabelToName(DST,SRC) AppendLiteralLabelString((DST),(SRC))
2516 //#define AppendStringNameToName(DST,SRC) AppendDNSNameString((DST),(SRC))
2517 //#define AppendDomainLabelToName(DST,SRC) AppendDomainLabel((DST),(SRC))
2518 //#define AppendDomainNameToName(DST,SRC) AppendDomainName((DST),(SRC))
2519
2520 // ***************************************************************************
2521 #if 0
2522 #pragma mark - Other utility functions and macros
2523 #endif
2524
2525 // mDNS_vsnprintf/snprintf return the number of characters written, excluding the final terminating null.
2526 // The output is always null-terminated: for example, if the output turns out to be exactly buflen long,
2527 // then the output will be truncated by one character to allow space for the terminating null.
2528 // Unlike standard C vsnprintf/snprintf, they return the number of characters *actually* written,
2529 // not the number of characters that *would* have been printed were buflen unlimited.
2530 extern mDNSu32 mDNS_vsnprintf(char *sbuffer, mDNSu32 buflen, const char *fmt, va_list arg);
2531 extern mDNSu32 mDNS_snprintf(char *sbuffer, mDNSu32 buflen, const char *fmt, ...) IS_A_PRINTF_STYLE_FUNCTION(3,4);
2532 extern mDNSu32 NumCacheRecordsForInterfaceID(const mDNS *const m, mDNSInterfaceID id);
2533 extern char *DNSTypeName(mDNSu16 rrtype);
2534 extern char *GetRRDisplayString_rdb(const ResourceRecord *rr, RDataBody *rd, char *buffer);
2535 #define RRDisplayString(m, rr) GetRRDisplayString_rdb(rr, &(rr)->rdata->u, (m)->MsgBuffer)
2536 #define ARDisplayString(m, rr) GetRRDisplayString_rdb(&(rr)->resrec, &(rr)->resrec.rdata->u, (m)->MsgBuffer)
2537 #define CRDisplayString(m, rr) GetRRDisplayString_rdb(&(rr)->resrec, &(rr)->resrec.rdata->u, (m)->MsgBuffer)
2538 extern mDNSBool mDNSSameAddress(const mDNSAddr *ip1, const mDNSAddr *ip2);
2539 extern void IncrementLabelSuffix(domainlabel *name, mDNSBool RichText);
2540 extern mDNSBool IsPrivateV4Addr(mDNSAddr *addr); // returns true for RFC1918 private addresses
2541
2542 #define mDNSSameIPv4Address(A,B) ((A).NotAnInteger == (B).NotAnInteger)
2543 #define mDNSSameIPv6Address(A,B) ((A).l[0] == (B).l[0] && (A).l[1] == (B).l[1] && (A).l[2] == (B).l[2] && (A).l[3] == (B).l[3])
2544 #define mDNSSameEthAddress(A,B) ((A)->w[0] == (B)->w[0] && (A)->w[1] == (B)->w[1] && (A)->w[2] == (B)->w[2])
2545
2546 #define mDNSIPv4AddressIsZero(A) mDNSSameIPv4Address((A), zerov4Addr)
2547 #define mDNSIPv6AddressIsZero(A) mDNSSameIPv6Address((A), zerov6Addr)
2548
2549 #define mDNSIPv4AddressIsOnes(A) mDNSSameIPv4Address((A), onesIPv4Addr)
2550 #define mDNSIPv6AddressIsOnes(A) mDNSSameIPv6Address((A), onesIPv6Addr)
2551
2552 #define mDNSAddressIsAllDNSLinkGroup(X) ( \
2553 ((X)->type == mDNSAddrType_IPv4 && mDNSSameIPv4Address((X)->ip.v4, AllDNSLinkGroupv4)) || \
2554 ((X)->type == mDNSAddrType_IPv6 && mDNSSameIPv6Address((X)->ip.v6, AllDNSLinkGroupv6)) )
2555
2556 #define mDNSAddressIsZero(X) ( \
2557 ((X)->type == mDNSAddrType_IPv4 && mDNSIPv4AddressIsZero((X)->ip.v4)) || \
2558 ((X)->type == mDNSAddrType_IPv6 && mDNSIPv6AddressIsZero((X)->ip.v6)) )
2559
2560 #define mDNSAddressIsValidNonZero(X) ( \
2561 ((X)->type == mDNSAddrType_IPv4 && !mDNSIPv4AddressIsZero((X)->ip.v4)) || \
2562 ((X)->type == mDNSAddrType_IPv6 && !mDNSIPv6AddressIsZero((X)->ip.v6)) )
2563
2564 #define mDNSAddressIsOnes(X) ( \
2565 ((X)->type == mDNSAddrType_IPv4 && mDNSIPv4AddressIsOnes((X)->ip.v4)) || \
2566 ((X)->type == mDNSAddrType_IPv6 && mDNSIPv6AddressIsOnes((X)->ip.v6)) )
2567
2568 #define mDNSAddressIsValid(X) ( \
2569 ((X)->type == mDNSAddrType_IPv4) ? !(mDNSIPv4AddressIsZero((X)->ip.v4) || mDNSIPv4AddressIsOnes((X)->ip.v4)) : \
2570 ((X)->type == mDNSAddrType_IPv6) ? !(mDNSIPv6AddressIsZero((X)->ip.v6) || mDNSIPv6AddressIsOnes((X)->ip.v6)) : mDNSfalse)
2571
2572
2573 // ***************************************************************************
2574 #if 0
2575 #pragma mark - Authentication Support
2576 #endif
2577
2578 #define HMAC_LEN 64
2579 #define HMAC_IPAD 0x36
2580 #define HMAC_OPAD 0x5c
2581 #define MD5_LEN 16
2582
2583 // padded keys for inned/outer hash rounds
2584 typedef struct
2585 {
2586 mDNSu8 ipad[HMAC_LEN];
2587 mDNSu8 opad[HMAC_LEN];
2588 } HMAC_Key;
2589
2590 // Internal data structure to maintain authentication information for an update domain
2591 typedef struct uDNS_AuthInfo
2592 {
2593 domainname zone;
2594 domainname keyname;
2595 HMAC_Key key;
2596 struct uDNS_AuthInfo *next;
2597 } uDNS_AuthInfo;
2598
2599 // Unicast DNS and Dynamic Update specific Client Calls
2600 //
2601 // mDNS_SetSecretForZone tells the core to authenticate (via TSIG with an HMAC_MD5 hash of the shared secret)
2602 // when dynamically updating a given zone (and its subdomains). The key used in authentication must be in
2603 // domain name format. The shared secret must be a null-terminated base64 encoded string. A minimum size of
2604 // 16 bytes (128 bits) is recommended for an MD5 hash as per RFC 2485.
2605 // Calling this routine multiple times for a zone replaces previously entered values. Call with a NULL key
2606 // to dissable authentication for the zone.
2607
2608 extern mStatus mDNS_SetSecretForZone(mDNS *m, const domainname *zone, const domainname *key, const char *sharedSecret);
2609
2610 // Hostname/Unicast Interface Configuration
2611
2612 // All hostnames advertised point to one IPv4 address and/or one IPv6 address, set via SetPrimaryInterfaceInfo. Invoking this routine
2613 // updates all existing hostnames to point to the new address.
2614
2615 // A hostname is added via AddDynDNSHostName, which points to the primary interface's v4 and/or v6 addresss
2616
2617 // The status callback is invoked to convey success or failure codes - the callback should not modify the AuthRecord or free memory.
2618 // Added hostnames may be removed (deregistered) via mDNS_RemoveDynDNSHostName.
2619
2620 // Host domains added prior to specification of the primary interface address and computer name will be deferred until
2621 // these values are initialized.
2622
2623 // When routable V4 interfaces are added or removed, mDNS_UpdateLLQs should be called to re-estabish LLQs in case the
2624 // destination address for events (i.e. the route) has changed. For performance reasons, the caller is responsible for
2625 // batching changes, e.g. calling the routine only once if multiple interfaces are simultanously removed or added.
2626
2627 // DNS servers used to resolve unicast queries are specified by mDNS_AddDNSServer, and may later be removed via mDNS_DeleteDNSServers.
2628 // For "split" DNS configurations, in which queries for different domains are sent to different servers (e.g. VPN and external),
2629 // a domain may be associated with a DNS server. For standard configurations, specify the root label (".") or NULL.
2630
2631 extern void mDNS_AddDynDNSHostName(mDNS *m, const domainname *fqdn, mDNSRecordCallback *StatusCallback, const void *StatusContext);
2632 extern void mDNS_RemoveDynDNSHostName(mDNS *m, const domainname *fqdn);
2633 extern void mDNS_SetPrimaryInterfaceInfo(mDNS *m, const mDNSAddr *v4addr, const mDNSAddr *v6addr, const mDNSAddr *router);
2634 extern void mDNS_UpdateLLQs(mDNS *m);
2635 extern void mDNS_AddDNSServer(mDNS *const m, const mDNSAddr *dnsAddr, const domainname *domain);
2636 extern void mDNS_DeleteDNSServers(mDNS *const m);
2637
2638 // Routines called by the core, exported by DNSDigest.c
2639
2640 // Convert a base64 encoded key into a binary byte stream
2641 extern mDNSs32 DNSDigest_Base64ToBin(const char *src, mDNSu8 *target, mDNSu32 targsize);
2642
2643 // Convert an arbitrary binary key (of any length) into an HMAC key (stored in AuthInfo struct)
2644 extern void DNSDigest_ConstructHMACKey(uDNS_AuthInfo *info, const mDNSu8 *key, mDNSu32 len);
2645
2646 // sign a DNS message. The message must be compete, with all values in network byte order. end points to the end
2647 // of the message, and is modified by this routine. numAdditionals is a pointer to the number of additional
2648 // records in HOST byte order, which is incremented upon successful completion of this routine. The function returns
2649 // the new end pointer on success, and NULL on failure.
2650 extern mDNSu8 *DNSDigest_SignMessage(DNSMessage *msg, mDNSu8 **end, mDNSu16 *numAdditionals, uDNS_AuthInfo *info);
2651
2652 // ***************************************************************************
2653 #if 0
2654 #pragma mark - PlatformSupport interface
2655 #endif
2656
2657 // This section defines the interface to the Platform Support layer.
2658 // Normal client code should not use any of types defined here, or directly call any of the functions defined here.
2659 // The definitions are placed here because sometimes clients do use these calls indirectly, via other supported client operations.
2660 // For example, AssignDomainName is a macro defined using mDNSPlatformMemCopy()
2661
2662 // Every platform support module must provide the following functions.
2663 // mDNSPlatformInit() typically opens a communication endpoint, and starts listening for mDNS packets.
2664 // When Setup is complete, the platform support layer calls mDNSCoreInitComplete().
2665 // mDNSPlatformSendUDP() sends one UDP packet
2666 // When a packet is received, the PlatformSupport code calls mDNSCoreReceive()
2667 // mDNSPlatformClose() tidies up on exit
2668 //
2669 // Note: mDNSPlatformMemAllocate/mDNSPlatformMemFree are only required for handling oversized resource records and unicast DNS.
2670 // If your target platform has a well-defined specialized application, and you know that all the records it uses
2671 // are InlineCacheRDSize or less, then you can just make a simple mDNSPlatformMemAllocate() stub that always returns
2672 // NULL. InlineCacheRDSize is a compile-time constant, which is set by default to 64. If you need to handle records
2673 // a little larger than this and you don't want to have to implement run-time allocation and freeing, then you
2674 // can raise the value of this constant to a suitable value (at the expense of increased memory usage).
2675 //
2676 // USE CAUTION WHEN CALLING mDNSPlatformRawTime: The m->timenow_adjust correction factor needs to be added
2677 // Generally speaking:
2678 // Code that's protected by the main mDNS lock should just use the m->timenow value
2679 // Code outside the main mDNS lock should use mDNS_TimeNow(m) to get properly adjusted time
2680 // In certain cases there may be reasons why it's necessary to get the time without taking the lock first
2681 // (e.g. inside the routines that are doing the locking and unlocking, where a call to get the lock would result in a
2682 // recursive loop); in these cases use mDNS_TimeNow_NoLock(m) to get mDNSPlatformRawTime with the proper correction factor added.
2683 //
2684 // mDNSPlatformUTC returns the time, in seconds, since Jan 1st 1970 UTC and is required for generating TSIG records
2685
2686 extern mStatus mDNSPlatformInit (mDNS *const m);
2687 extern void mDNSPlatformClose (mDNS *const m);
2688 extern mStatus mDNSPlatformSendUDP(const mDNS *const m, const void *const msg, const mDNSu8 *const end,
2689 mDNSInterfaceID InterfaceID, const mDNSAddr *dst, mDNSIPPort dstport);
2690
2691 extern void mDNSPlatformLock (const mDNS *const m);
2692 extern void mDNSPlatformUnlock (const mDNS *const m);
2693
2694 extern void mDNSPlatformStrCopy (const void *src, void *dst);
2695 extern mDNSu32 mDNSPlatformStrLen (const void *src);
2696 extern void mDNSPlatformMemCopy (const void *src, void *dst, mDNSu32 len);
2697 extern mDNSBool mDNSPlatformMemSame (const void *src, const void *dst, mDNSu32 len);
2698 extern void mDNSPlatformMemZero ( void *dst, mDNSu32 len);
2699 extern void * mDNSPlatformMemAllocate (mDNSu32 len);
2700 extern void mDNSPlatformMemFree (void *mem);
2701 extern mDNSu32 mDNSPlatformRandomSeed (void);
2702 extern mStatus mDNSPlatformTimeInit (void);
2703 extern mDNSs32 mDNSPlatformRawTime (void);
2704 extern mDNSs32 mDNSPlatformUTC (void);
2705 #define mDNS_TimeNow_NoLock(m) (mDNSPlatformRawTime() + m->timenow_adjust)
2706
2707 // Platform support modules should provide the following functions to map between opaque interface IDs
2708 // and interface indexes in order to support the DNS-SD API. If your target platform does not support
2709 // multiple interfaces and/or does not support the DNS-SD API, these functions can be empty.
2710 extern mDNSInterfaceID mDNSPlatformInterfaceIDfromInterfaceIndex(mDNS *const m, mDNSu32 index);
2711 extern mDNSu32 mDNSPlatformInterfaceIndexfromInterfaceID(mDNS *const m, mDNSInterfaceID id);
2712
2713 // Every platform support module must provide the following functions if it is to support unicast DNS
2714 // and Dynamic Update.
2715 // All TCP socket operations implemented by the platform layer MUST NOT BLOCK.
2716 // mDNSPlatformTCPConnect initiates a TCP connection with a peer, adding the socket descriptor to the
2717 // main event loop. The return value indicates whether the connection succeeded, failed, or is pending
2718 // (i.e. the call would block.) On return, the descriptor parameter is set to point to the connected socket.
2719 // The TCPConnectionCallback is subsequently invoked when the connection
2720 // completes (in which case the ConnectionEstablished parameter is true), or data is available for
2721 // reading on the socket (indicated by the ConnectionEstablished parameter being false.) If the connection
2722 // asynchronously fails, the TCPConnectionCallback should be invoked as usual, with the error being
2723 // returned in subsequent calls to PlatformReadTCP or PlatformWriteTCP. (This allows for platforms
2724 // with limited asynchronous error detection capabilities.) PlatformReadTCP and PlatformWriteTCP must
2725 // return the number of bytes read/written, 0 if the call would block, and -1 if an error.
2726 // PlatformTCPCloseConnection must close the connection to the peer and remove the descriptor from the
2727 // event loop. CloseConnectin may be called at any time, including in a ConnectionCallback.
2728
2729 typedef void (*TCPConnectionCallback)(int sd, void *context, mDNSBool ConnectionEstablished);
2730 extern mStatus mDNSPlatformTCPConnect(const mDNSAddr *dst, mDNSOpaque16 dstport, mDNSInterfaceID InterfaceID,
2731 TCPConnectionCallback callback, void *context, int *descriptor);
2732 extern void mDNSPlatformTCPCloseConnection(int sd);
2733 extern int mDNSPlatformReadTCP(int sd, void *buf, int buflen);
2734 extern int mDNSPlatformWriteTCP(int sd, const char *msg, int len);
2735
2736 // Platforms that support unicast browsing and dynamic update registration for clients who do not specify a domain
2737 // in browse/registration calls must implement these routines to get the "default" browse/registration list.
2738 // The Get() functions must return a linked list of DNameListElem structs, allocated via mDNSPlatformMemAllocate.
2739 // Platforms may implement the Get() calls via the mDNS_CopyDNameList() helper routine.
2740 // Callers should free lists obtained via the Get() calls with th mDNS_FreeDNameList routine, provided by the core.
2741
2742 typedef struct DNameListElem
2743 {
2744 domainname name;
2745 struct DNameListElem *next;
2746 } DNameListElem;
2747
2748 extern DNameListElem *mDNSPlatformGetSearchDomainList(void);
2749 extern DNameListElem *mDNSPlatformGetRegDomainList(void);
2750
2751 // Helper functions provided by the core
2752 extern DNameListElem *mDNS_CopyDNameList(const DNameListElem *orig);
2753 extern void mDNS_FreeDNameList(DNameListElem *list);
2754
2755 #ifdef _LEGACY_NAT_TRAVERSAL_
2756 // Support for legacy NAT traversal protocols, implemented by the platform layer and callable by the core.
2757
2758 #define DYN_PORT_MIN 49152 // ephemeral port range
2759 #define DYN_PORT_MAX 65535
2760 #define LEGACY_NATMAP_MAX_TRIES 4 // if our desired mapping is taken, how many times we try mapping to a random port
2761
2762 extern mStatus LNT_GetPublicIP(mDNSOpaque32 *ip);
2763 extern mStatus LNT_MapPort(mDNSIPPort priv, mDNSIPPort pub, mDNSBool tcp);
2764 extern mStatus LNT_UnmapPort(mDNSIPPort PubPort, mDNSBool tcp);
2765 #endif // _LEGACY_NAT_TRAVERSAL_
2766
2767 // The core mDNS code provides these functions, for the platform support code to call at appropriate times
2768 //
2769 // mDNS_SetFQDN() is called once on startup (typically from mDNSPlatformInit())
2770 // and then again on each subsequent change of the host name.
2771 //
2772 // mDNS_RegisterInterface() is used by the platform support layer to inform mDNSCore of what
2773 // physical and/or logical interfaces are available for sending and receiving packets.
2774 // Typically it is called on startup for each available interface, but register/deregister may be
2775 // called again later, on multiple occasions, to inform the core of interface configuration changes.
2776 // If set->Advertise is set non-zero, then mDNS_RegisterInterface() also registers the standard
2777 // resource records that should be associated with every publicised IP address/interface:
2778 // -- Name-to-address records (A/AAAA)
2779 // -- Address-to-name records (PTR)
2780 // -- Host information (HINFO)
2781 // IMPORTANT: The specified mDNSInterfaceID MUST NOT be 0, -1, or -2; these values have special meaning
2782 // mDNS_RegisterInterface does not result in the registration of global hostnames via dynamic update -
2783 // see mDNS_SetPrimaryInterfaceInfo, mDNS_AddDynDNSHostName, etc. for this purpose.
2784 // Note that the set may be deallocated immediately after it is deregistered via mDNS_DeegisterInterface.
2785 //
2786 // mDNS_RegisterDNS() is used by the platform support layer to provide the core with the addresses of
2787 // available domain name servers for unicast queries/updates. RegisterDNS() should be called once for
2788 // each name server, typically at startup, or when a new name server becomes available. DeregiterDNS()
2789 // must be called whenever a registered name server becomes unavailable. DeregisterDNSList deregisters
2790 // all registered servers. mDNS_DNSRegistered() returns true if one or more servers are registered in the core.
2791 //
2792 // mDNSCoreInitComplete() is called when the platform support layer is finished.
2793 // Typically this is at the end of mDNSPlatformInit(), but may be later
2794 // (on platforms like OT that allow asynchronous initialization of the networking stack).
2795 //
2796 // mDNSCoreReceive() is called when a UDP packet is received
2797 //
2798 // mDNSCoreMachineSleep() is called when the machine sleeps or wakes
2799 // (This refers to heavyweight laptop-style sleep/wake that disables network access,
2800 // not lightweight second-by-second CPU power management modes.)
2801
2802 extern void mDNS_SetFQDN(mDNS *const m);
2803 extern mStatus mDNS_RegisterInterface (mDNS *const m, NetworkInterfaceInfo *set, mDNSBool flapping);
2804 extern void mDNS_DeregisterInterface(mDNS *const m, NetworkInterfaceInfo *set, mDNSBool flapping);
2805 extern void mDNSCoreInitComplete(mDNS *const m, mStatus result);
2806 extern void mDNSCoreReceive(mDNS *const m, void *const msg, const mDNSu8 *const end,
2807 const mDNSAddr *const srcaddr, const mDNSIPPort srcport,
2808 const mDNSAddr *const dstaddr, const mDNSIPPort dstport, const mDNSInterfaceID InterfaceID);
2809 extern void mDNSCoreMachineSleep(mDNS *const m, mDNSBool wake);
2810
2811 extern mDNSBool mDNSAddrIsDNSMulticast(const mDNSAddr *ip);
2812
2813 // ***************************************************************************
2814 #if 0
2815 #pragma mark - Compile-Time assertion checks
2816 #endif
2817
2818 // Some C compiler cleverness. We can make the compiler check certain things for
2819 // us, and report compile-time errors if anything is wrong. The usual way to do
2820 // this would be to use a run-time "if" statement, but then you don't find out
2821 // what's wrong until you run the software. This way, if the assertion condition
2822 // is false, the array size is negative, and the complier complains immediately.
2823
2824 struct mDNS_CompileTimeAssertionChecks
2825 {
2826 // Check that the compiler generated our on-the-wire packet format structure definitions
2827 // properly packed, without adding padding bytes to align fields on 32-bit or 64-bit boundaries.
2828 char assert0[(sizeof(rdataSRV) == 262 ) ? 1 : -1];
2829 char assert1[(sizeof(DNSMessageHeader) == 12 ) ? 1 : -1];
2830 char assert2[(sizeof(DNSMessage) == 12+AbsoluteMaxDNSMessageData) ? 1 : -1];
2831 char assert3[(sizeof(mDNSs8) == 1 ) ? 1 : -1];
2832 char assert4[(sizeof(mDNSu8) == 1 ) ? 1 : -1];
2833 char assert5[(sizeof(mDNSs16) == 2 ) ? 1 : -1];
2834 char assert6[(sizeof(mDNSu16) == 2 ) ? 1 : -1];
2835 char assert7[(sizeof(mDNSs32) == 4 ) ? 1 : -1];
2836 char assert8[(sizeof(mDNSu32) == 4 ) ? 1 : -1];
2837 char assert9[(sizeof(mDNSOpaque16) == 2 ) ? 1 : -1];
2838 char assertA[(sizeof(mDNSOpaque32) == 4 ) ? 1 : -1];
2839 char assertB[(sizeof(mDNSOpaque128) == 16 ) ? 1 : -1];
2840 char assertC[(sizeof(CacheRecord ) >= sizeof(CacheGroup) ) ? 1 : -1];
2841 char assertD[(sizeof(int) >= 4 ) ? 1 : -1];
2842 };
2843
2844 // ***************************************************************************
2845
2846 #ifdef __cplusplus
2847 }
2848 #endif
2849
2850 #endif
2851