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25 If you're building an application that uses DNS Service Discovery
26 this is probably NOT the header file you're looking for.
27 In most cases you will want to use /usr/include/dns_sd.h instead.
29 This header file defines the lowest level raw interface to mDNSCore,
30 which is appropriate *only* on tiny embedded systems where everything
31 runs in a single address space and memory is extremely constrained.
32 All the APIs here are malloc-free, which means that the caller is
33 responsible for passing in a pointer to the relevant storage that
34 will be used in the execution of that call, and (when called with
35 correct parameters) all the calls are guaranteed to succeed. There
36 is never a case where a call can suffer intermittent failures because
37 the implementation calls malloc() and sometimes malloc() returns NULL
38 because memory is so limited that no more is available.
39 This is primarily for devices that need to have precisely known fixed
40 memory requirements, with absolutely no uncertainty or run-time variation,
41 but that certainty comes at a cost of more difficult programming.
43 For applications running on general-purpose desktop operating systems
44 (Mac OS, Linux, Solaris, Windows, etc.) the API you should use is
45 /usr/include/dns_sd.h, which defines the API by which multiple
46 independent client processes communicate their DNS Service Discovery
47 requests to a single "mdnsd" daemon running in the background.
49 Even on platforms that don't run multiple independent processes in
50 multiple independent address spaces, you can still use the preferred
51 dns_sd.h APIs by linking in "dnssd_clientshim.c", which implements
52 the standard "dns_sd.h" API calls, allocates any required storage
53 using malloc(), and then calls through to the low-level malloc-free
54 mDNSCore routines defined here. This has the benefit that even though
55 you're running on a small embedded system with a single address space,
56 you can still use the exact same client C code as you'd use on a
57 general-purpose desktop system.
60 Change History (most recent first):
62 $Log: mDNSEmbeddedAPI.h,v $
63 Revision 1.287 2005/10/20 00:10:33 cheshire
64 <rdar://problem/4290265> Add check to avoid crashing NAT gateways that have buggy DNS relay code
66 Revision 1.286 2005/09/24 01:09:40 cheshire
69 Revision 1.285 2005/09/16 20:57:47 cheshire
70 Add macro mDNS_TimeNow_NoLock(m) to get properly adjusted time without also acquiring lock
72 Revision 1.284 2005/07/29 18:04:22 ksekar
73 <rdar://problem/4137930> Hostname registration should register IPv6 AAAA record with DNS Update
75 Revision 1.283 2005/05/13 20:45:09 ksekar
76 <rdar://problem/4074400> Rapid wide-area txt record updates don't work
78 Revision 1.282 2005/03/16 00:42:32 ksekar
79 <rdar://problem/4012279> Long-lived queries not working on Windows
81 Revision 1.281 2005/02/25 17:47:44 ksekar
82 <rdar://problem/4021868> SendServiceRegistration fails on wake from sleep
84 Revision 1.280 2005/02/25 04:21:00 cheshire
85 <rdar://problem/4015377> mDNS -F returns the same domain multiple times with different casing
87 Revision 1.279 2005/02/17 01:56:14 cheshire
88 Increase ifname field to 64 bytes
90 Revision 1.278 2005/02/09 23:38:51 ksekar
91 <rdar://problem/3993508> Reregister hostname when DNS server changes but IP address does not
93 Revision 1.277 2005/02/09 23:31:12 ksekar
94 <rdar://problem/3984374> NAT-PMP response callback should return a boolean indicating if the packet matched the request
96 Revision 1.276 2005/02/01 19:33:29 ksekar
97 <rdar://problem/3985239> Keychain format too restrictive
99 Revision 1.275 2005/01/27 22:57:55 cheshire
100 Fix compile errors on gcc4
102 Revision 1.274 2005/01/19 21:01:54 ksekar
103 <rdar://problem/3955355> uDNS needs to support subtype registration and browsing
105 Revision 1.273 2005/01/19 19:15:31 ksekar
106 Refinement to <rdar://problem/3954575> - Simplify mDNS_PurgeResultsForDomain logic and move into daemon layer
108 Revision 1.272 2005/01/18 18:10:55 ksekar
109 <rdar://problem/3954575> Use 10.4 resolver API to get search domains
111 Revision 1.271 2005/01/15 00:56:41 ksekar
112 <rdar://problem/3954575> Unicast services don't disappear when logging
115 Revision 1.270 2005/01/14 18:34:22 ksekar
116 <rdar://problem/3954571> Services registered outside of firewall don't succeed after location change
118 Revision 1.269 2005/01/11 22:50:52 ksekar
119 Fixed constant naming (was using kLLQ_DefLease for update leases)
121 Revision 1.268 2004/12/22 22:25:47 ksekar
122 <rdar://problem/3734265> NAT-PMP: handle location changes
124 Revision 1.267 2004/12/22 00:13:49 ksekar
125 <rdar://problem/3873993> Change version, port, and polling interval for LLQ
127 Revision 1.266 2004/12/18 03:13:45 cheshire
128 <rdar://problem/3751638> kDNSServiceInterfaceIndexLocalOnly should return all local records
130 Revision 1.265 2004/12/17 23:37:45 cheshire
131 <rdar://problem/3485365> Guard against repeating wireless dissociation/re-association
132 (and other repetitive configuration changes)
134 Revision 1.264 2004/12/17 05:25:46 cheshire
135 <rdar://problem/3925163> Shorten DNS-SD queries to avoid NAT bugs
137 Revision 1.263 2004/12/16 20:40:25 cheshire
140 Revision 1.262 2004/12/16 20:13:00 cheshire
141 <rdar://problem/3324626> Cache memory management improvements
143 Revision 1.261 2004/12/14 21:21:20 ksekar
144 <rdar://problem/3825979> NAT-PMP: Update response format to contain "Seconds Since Boot"
146 Revision 1.260 2004/12/12 23:51:42 ksekar
147 <rdar://problem/3845683> Wide-area registrations should fallback to using DHCP hostname as target
149 Revision 1.259 2004/12/11 20:55:29 ksekar
150 <rdar://problem/3916479> Clean up registration state machines
152 Revision 1.258 2004/12/10 20:48:32 cheshire
153 <rdar://problem/3705229> Need to pick final EDNS numbers for LLQ and GC
155 Revision 1.257 2004/12/10 02:09:23 cheshire
156 <rdar://problem/3898376> Modify default TTLs
158 Revision 1.256 2004/12/09 03:15:40 ksekar
159 <rdar://problem/3806610> use _legacy instead of _default to find "empty string" browse domains
161 Revision 1.255 2004/12/07 22:48:37 cheshire
164 Revision 1.254 2004/12/07 21:26:04 ksekar
165 <rdar://problem/3908336> DNSServiceRegisterRecord() can crash on deregistration
167 Revision 1.253 2004/12/07 20:42:33 cheshire
168 Add explicit context parameter to mDNS_RemoveRecordFromService()
170 Revision 1.252 2004/12/07 03:02:12 ksekar
171 Fixed comments, grouped unicast-specific routines together
173 Revision 1.251 2004/12/06 21:15:22 ksekar
174 <rdar://problem/3884386> mDNSResponder crashed in CheckServiceRegistrations
176 Revision 1.250 2004/12/04 02:12:45 cheshire
177 <rdar://problem/3517236> mDNSResponder puts LargeCacheRecord on the stack
179 Revision 1.249 2004/12/03 05:18:33 ksekar
180 <rdar://problem/3810596> mDNSResponder needs to return more specific TSIG errors
182 Revision 1.248 2004/12/02 20:03:48 ksekar
183 <rdar://problem/3889647> Still publishes wide-area domains even after switching to a local subnet
185 Revision 1.247 2004/12/01 20:57:19 ksekar
186 <rdar://problem/3873921> Wide Area Service Discovery must be split-DNS aware
188 Revision 1.246 2004/11/29 23:26:32 cheshire
189 Added NonZeroTime() function, which usually returns the value given, with the exception
190 that if the value given is zero, it returns one instead. For timer values where zero is
191 used to mean "not set", this can be used to ensure that setting them to the result of an
192 interval computation (e.g. "now+interval") does not inadvertently result in a zero value.
194 Revision 1.245 2004/11/25 01:28:09 cheshire
195 <rdar://problem/3557050> Need to implement random delay for 'QU' unicast replies (and set cache flush bit too)
197 Revision 1.244 2004/11/24 22:00:59 cheshire
198 Move definition of mDNSAddressIsAllDNSLinkGroup() from mDNSMacOSX.c to mDNSEmbeddedAPI.h
200 Revision 1.243 2004/11/23 22:43:53 cheshire
201 Tidy up code alignment
203 Revision 1.242 2004/11/23 03:39:46 cheshire
204 Let interface name/index mapping capability live directly in JNISupport.c,
205 instead of having to call through to the daemon via IPC to get this information.
207 Revision 1.241 2004/11/22 17:16:19 ksekar
208 <rdar://problem/3854298> Unicast services don't disappear when you disable all networking
210 Revision 1.240 2004/11/19 02:32:43 ksekar
211 Wide-Area Security: Add LLQ-ID to events
213 Revision 1.239 2004/11/15 20:09:23 ksekar
214 <rdar://problem/3719050> Wide Area support for Add/Remove record
216 Revision 1.238 2004/11/12 03:16:48 rpantos
217 rdar://problem/3809541 Add mDNSPlatformGetInterfaceByName, mDNSPlatformGetInterfaceName
219 Revision 1.237 2004/11/10 20:40:53 ksekar
220 <rdar://problem/3868216> LLQ mobility fragile on non-primary interface
222 Revision 1.236 2004/11/01 20:36:11 ksekar
223 <rdar://problem/3802395> mDNSResponder should not receive Keychain Notifications
225 Revision 1.235 2004/11/01 17:48:14 cheshire
226 Changed SOA serial number back to signed. RFC 1035 may describe it as "unsigned", but
227 it's wrong. The SOA serial is a modular counter, as explained in "DNS & BIND", page
228 137. Since C doesn't have a modular type, we used signed, C's closest approximation.
230 Revision 1.234 2004/10/29 21:59:02 ksekar
231 SOA serial should be a unsigned integer, as per RFC 1035
233 Revision 1.233 2004/10/28 03:24:41 cheshire
234 Rename m->CanReceiveUnicastOn as m->CanReceiveUnicastOn5353
236 Revision 1.232 2004/10/26 06:20:23 cheshire
237 Add mDNSAddressIsValidNonZero() macro
239 Revision 1.231 2004/10/26 06:11:41 cheshire
240 Add improved logging to aid in diagnosis of <rdar://problem/3842714> mDNSResponder crashed
242 Revision 1.230 2004/10/26 03:52:02 cheshire
243 Update checkin comments
245 Revision 1.229 2004/10/25 19:30:52 ksekar
246 <rdar://problem/3827956> Simplify dynamic host name structures
248 Revision 1.228 2004/10/23 01:16:00 cheshire
249 <rdar://problem/3851677> uDNS operations not always reliable on multi-homed hosts
251 Revision 1.227 2004/10/22 20:52:07 ksekar
252 <rdar://problem/3799260> Create NAT port mappings for Long Lived Queries
254 Revision 1.226 2004/10/20 01:50:40 cheshire
255 <rdar://problem/3844991> Cannot resolve non-local registrations using the mach API
256 Implemented ForceMCast mode for AuthRecords as well as for Questions
258 Revision 1.225 2004/10/19 21:33:17 cheshire
259 <rdar://problem/3844991> Cannot resolve non-local registrations using the mach API
260 Added flag 'kDNSServiceFlagsForceMulticast'. Passing through an interface id for a unicast name
261 doesn't force multicast unless you set this flag to indicate explicitly that this is what you want
263 Revision 1.224 2004/10/16 00:16:59 cheshire
264 <rdar://problem/3770558> Replace IP TTL 255 check with local subnet source address check
266 Revision 1.223 2004/10/15 23:00:17 ksekar
267 <rdar://problem/3799242> Need to update LLQs on location changes
269 Revision 1.222 2004/10/12 02:49:20 ksekar
270 <rdar://problem/3831228> Clean up LLQ sleep/wake, error handling
272 Revision 1.221 2004/10/10 06:57:15 cheshire
273 Change definition of "localdomain" to make code compile a little smaller
275 Revision 1.220 2004/10/06 01:44:19 cheshire
276 <rdar://problem/3813936> Resolving too quickly sometimes returns stale TXT record
278 Revision 1.219 2004/10/03 23:18:58 cheshire
279 Move address comparison macros from DNSCommon.h to mDNSEmbeddedAPI.h
281 Revision 1.218 2004/10/03 23:14:12 cheshire
282 Add "mDNSEthAddr" type and "zeroEthAddr" constant
284 Revision 1.217 2004/09/30 00:24:56 ksekar
285 <rdar://problem/3695802> Dynamically update default registration domains on config change
287 Revision 1.216 2004/09/27 23:24:32 cheshire
288 Fix typo: SOA refresh interval is supposed to be unsigned
290 Revision 1.215 2004/09/26 23:20:35 ksekar
291 <rdar://problem/3813108> Allow default registrations in multiple wide-area domains
293 Revision 1.214 2004/09/25 02:41:39 cheshire
294 <rdar://problem/3637266> Deliver near-pending "remove" events before new "add" events
296 Revision 1.213 2004/09/25 02:24:27 cheshire
297 Removed unused rr->UseCount
299 Revision 1.212 2004/09/24 20:57:39 cheshire
300 <rdar://problem/3680902> Eliminate inappropriate casts that cause misaligned-address errors
302 Revision 1.211 2004/09/24 20:33:22 cheshire
303 Remove unused DNSDigest_MD5 declaration
305 Revision 1.210 2004/09/23 20:21:07 cheshire
306 <rdar://problem/3426876> Refine "immediate answer burst; restarting exponential backoff sequence" logic
307 Associate a unique sequence number with each received packet, and only increment the count of recent answer
308 packets if the packet sequence number for this answer record is not one we've already seen and counted.
310 Revision 1.209 2004/09/23 20:14:39 cheshire
311 Rename "question->RecentAnswers" to "question->RecentAnswerPkts"
313 Revision 1.208 2004/09/23 00:50:53 cheshire
314 <rdar://problem/3419452> Don't send a (DE) if a service is unregistered after wake from sleep
316 Revision 1.207 2004/09/22 02:34:46 cheshire
317 Move definitions of default TTL times from mDNS.c to mDNSEmbeddedAPI.h
319 Revision 1.206 2004/09/22 00:41:59 cheshire
320 Move tcp connection status codes into the legal range allocated for mDNS use
322 Revision 1.205 2004/09/21 23:40:11 ksekar
323 <rdar://problem/3810349> mDNSResponder to return errors on NAT traversal failure
325 Revision 1.204 2004/09/21 23:29:50 cheshire
326 <rdar://problem/3680045> DNSServiceResolve should delay sending packets
328 Revision 1.203 2004/09/21 20:58:22 cheshire
329 Add ifname field to NetworkInterfaceInfo_struct
331 Revision 1.202 2004/09/17 00:46:34 cheshire
332 mDNS_TimeNow should take const mDNS parameter
334 Revision 1.201 2004/09/17 00:31:51 cheshire
335 For consistency with ipv6, renamed rdata field 'ip' to 'ipv4'
337 Revision 1.200 2004/09/17 00:19:10 cheshire
338 For consistency with AllDNSLinkGroupv6, rename AllDNSLinkGroup to AllDNSLinkGroupv4
340 Revision 1.199 2004/09/16 21:59:16 cheshire
341 For consistency with zerov6Addr, rename zeroIPAddr to zerov4Addr
343 Revision 1.198 2004/09/16 21:36:36 cheshire
344 <rdar://problem/3803162> Fix unsafe use of mDNSPlatformTimeNow()
345 Changes to add necessary locking calls around unicast DNS operations
347 Revision 1.197 2004/09/16 00:24:48 cheshire
348 <rdar://problem/3803162> Fix unsafe use of mDNSPlatformTimeNow()
350 Revision 1.196 2004/09/14 23:42:35 cheshire
351 <rdar://problem/3801296> Need to seed random number generator from platform-layer data
353 Revision 1.195 2004/09/14 23:27:46 cheshire
356 Revision 1.194 2004/09/10 00:49:57 cheshire
357 <rdar://problem/3787644> Add error code kDNSServiceErr_Firewall, for future use
359 Revision 1.193 2004/09/03 19:23:05 ksekar
360 <rdar://problem/3788460>: Need retransmission mechanism for wide-area service registrations
362 Revision 1.192 2004/09/02 03:48:47 cheshire
363 <rdar://problem/3709039> Disable targeted unicast query support by default
364 1. New flag kDNSServiceFlagsAllowRemoteQuery to indicate we want to allow remote queries for this record
365 2. New field AllowRemoteQuery in AuthRecord structure
366 3. uds_daemon.c sets AllowRemoteQuery if kDNSServiceFlagsAllowRemoteQuery is set
367 4. mDNS.c only answers remote queries if AllowRemoteQuery is set
369 Revision 1.191 2004/08/25 00:37:27 ksekar
370 <rdar://problem/3774635>: Cleanup DynDNS hostname registration code
372 Revision 1.190 2004/08/18 17:35:41 ksekar
373 <rdar://problem/3651443>: Feature #9586: Need support for Legacy NAT gateways
375 Revision 1.189 2004/08/14 03:22:41 cheshire
376 <rdar://problem/3762579> Dynamic DNS UI <-> mDNSResponder glue
377 Add GetUserSpecifiedDDNSName() routine
378 Convert ServiceRegDomain to domainname instead of C string
379 Replace mDNS_GenerateFQDN/mDNS_GenerateGlobalFQDN with mDNS_SetFQDNs
381 Revision 1.188 2004/08/13 23:46:58 cheshire
382 "asyncronous" -> "asynchronous"
384 Revision 1.187 2004/08/13 23:37:02 cheshire
385 Now that we do both uDNS and mDNS, global replace "uDNS_info.hostname" with
386 "uDNS_info.UnicastHostname" for clarity
388 Revision 1.186 2004/08/13 23:25:00 cheshire
389 Now that we do both uDNS and mDNS, global replace "m->hostname" with
390 "m->MulticastHostname" for clarity
392 Revision 1.185 2004/08/12 00:32:36 ksekar
393 <rdar://problem/3759567>: LLQ Refreshes never terminate if unanswered
395 Revision 1.184 2004/08/11 17:09:31 cheshire
396 Add comment clarifying the applicability of these APIs
398 Revision 1.183 2004/08/10 23:19:14 ksekar
399 <rdar://problem/3722542>: DNS Extension daemon for Wide Area Service Discovery
400 Moved routines/constants to allow extern access for garbage collection daemon
402 Revision 1.182 2004/07/30 17:40:06 ksekar
403 <rdar://problem/3739115>: TXT Record updates not available for wide-area services
405 Revision 1.181 2004/07/29 19:27:15 ksekar
406 NAT-PMP Support - minor fixes and cleanup
408 Revision 1.180 2004/07/29 02:03:35 ksekar
409 Delete unused #define and structure field
411 Revision 1.179 2004/07/26 22:49:30 ksekar
412 <rdar://problem/3651409>: Feature #9516: Need support for NAT-PMP in client
414 Revision 1.178 2004/07/13 21:24:24 rpantos
415 Fix for <rdar://problem/3701120>.
417 Revision 1.177 2004/06/05 00:04:26 cheshire
418 <rdar://problem/3668639>: wide-area domains should be returned in reg. domain enumeration
420 Revision 1.176 2004/06/04 08:58:29 ksekar
421 <rdar://problem/3668624>: Keychain integration for secure dynamic update
423 Revision 1.175 2004/06/04 00:15:06 cheshire
424 Move misplaced brackets
426 Revision 1.174 2004/06/03 23:30:16 cheshire
427 Remove extraneous blank lines and white space
429 Revision 1.173 2004/06/03 03:09:58 ksekar
430 <rdar://problem/3668626>: Garbage Collection for Dynamic Updates
432 Revision 1.172 2004/06/01 23:46:50 ksekar
433 <rdar://problem/3675149>: DynDNS: dynamically look up LLQ/Update ports
435 Revision 1.171 2004/05/28 23:42:37 ksekar
436 <rdar://problem/3258021>: Feature: DNS server->client notification on record changes (#7805)
438 Revision 1.170 2004/05/18 23:51:25 cheshire
439 Tidy up all checkin comments to use consistent "<rdar://problem/xxxxxxx>" format for bug numbers
441 Revision 1.169 2004/05/13 04:54:20 ksekar
442 Unified list copy/free code. Added symetric list for
444 Revision 1.168 2004/05/12 22:03:09 ksekar
445 Made GetSearchDomainList a true platform-layer call (declaration moved
446 from mDNSMacOSX.h to mDNSEmbeddedAPI.h), implemented to return "local"
447 only on non-OSX platforms. Changed call to return a copy of the list
448 to avoid shared memory issues. Added a routine to free the list.
450 Revision 1.167 2004/04/22 04:07:01 cheshire
451 Fix from Bob Bradley: Don't try to do inline functions on compilers that don't support it
453 Revision 1.166 2004/04/22 03:15:56 cheshire
454 Fix use of "struct __attribute__((__packed__))" so it only applies on GCC >= 2.9
456 Revision 1.165 2004/04/22 03:05:28 cheshire
457 kDNSClass_ANY should be kDNSQClass_ANY
459 Revision 1.164 2004/04/21 02:55:03 cheshire
460 Update comments describing 'InterfaceActive' field
462 Revision 1.163 2004/04/21 02:49:11 cheshire
463 To reduce future confusion, renamed 'TxAndRx' to 'McastTxRx'
465 Revision 1.162 2004/04/15 00:51:28 bradley
466 Minor tweaks for Windows and C++ builds. Added casts for signed/unsigned integers and 64-bit pointers.
467 Prefix some functions with mDNS to avoid conflicts. Disable benign warnings on Microsoft compilers.
469 Revision 1.161 2004/04/14 23:09:28 ksekar
470 Support for TSIG signed dynamic updates.
472 Revision 1.160 2004/04/09 17:40:26 cheshire
473 Remove unnecessary "Multicast" field -- it duplicates the semantics of the existing McastTxRx field
475 Revision 1.159 2004/04/09 16:37:15 cheshire
476 Suggestion from Bob Bradley:
477 Move NumCacheRecordsForInterfaceID() to DNSCommon.c so it's available to all platform layers
479 Revision 1.158 2004/04/02 19:38:33 cheshire
480 Update comment about typical RR TTLs
482 Revision 1.157 2004/04/02 19:35:53 cheshire
483 Add clarifying comments about legal mDNSInterfaceID values
485 Revision 1.156 2004/04/02 19:19:48 cheshire
486 Add code to do optional logging of multi-packet KA list time intervals
488 Revision 1.155 2004/03/24 00:29:45 ksekar
489 Make it safe to call StopQuery in a unicast question callback
491 Revision 1.154 2004/03/20 01:05:49 cheshire
492 Test __LP64__ and __ILP64__ to compile properly on a wider range of 64-bit architectures
494 Revision 1.153 2004/03/13 01:57:33 ksekar
495 <rdar://problem/3192546>: DynDNS: Dynamic update of service records
497 Revision 1.152 2004/03/09 02:27:16 cheshire
498 Remove erroneous underscore in 'packed_struct' (makes no difference now, but might in future)
500 Revision 1.151 2004/03/02 03:21:56 cheshire
501 <rdar://problem/3549576> Properly support "_services._dns-sd._udp" meta-queries
503 Revision 1.150 2004/02/21 02:06:24 cheshire
504 Can't use anonymous unions -- they're non-standard and don't work on all compilers
506 Revision 1.149 2004/02/06 23:04:19 ksekar
507 Basic Dynamic Update support via mDNS_Register (dissabled via
508 UNICAST_REGISTRATION #define)
510 Revision 1.148 2004/02/03 19:47:36 ksekar
511 Added an asynchronous state machine mechanism to uDNS.c, including
512 calls to find the parent zone for a domain name. Changes include code
513 in repository previously dissabled via "#if 0 incomplete". Codepath
514 is currently unused, and will be called to create update records, etc.
516 Revision 1.147 2004/02/03 18:57:35 cheshire
517 Update comment for "IsLocalDomain()"
519 Revision 1.146 2004/01/30 02:20:24 bradley
520 Map inline to __inline when building with Microsoft C compilers since they do not support C99 inline.
522 Revision 1.145 2004/01/29 02:59:17 ksekar
523 Unicast DNS: Changed from a resource record oriented question/response
524 matching to packet based matching. New callback architecture allows
525 collections of records in a response to be processed differently
526 depending on the nature of the request, and allows the same structure
527 to be used for internal and client-driven queries with different processing needs.
529 Revision 1.144 2004/01/28 20:20:45 ksekar
530 Unified ActiveQueries and ActiveInternalQueries lists, using a flag to
531 demux them. Check-in includes work-in-progress code, #ifdef'd out.
533 Revision 1.143 2004/01/28 03:41:00 cheshire
534 <rdar://problem/3541946>: Need ability to do targeted queries as well as multicast queries
536 Revision 1.142 2004/01/28 02:30:07 ksekar
537 Added default Search Domains to unicast browsing, controlled via
538 Networking sharing prefs pane. Stopped sending unicast messages on
539 every interface. Fixed unicast resolving via mach-port API.
541 Revision 1.141 2004/01/27 20:15:22 cheshire
542 <rdar://problem/3541288>: Time to prune obsolete code for listening on port 53
544 Revision 1.140 2004/01/24 23:37:08 cheshire
545 At Kiren's suggestion, made functions to convert mDNSOpaque16s to/from integer values
547 Revision 1.139 2004/01/24 08:46:26 bradley
548 Added InterfaceID<->Index platform interfaces since they are now used by all platforms for the DNS-SD APIs.
550 Revision 1.138 2004/01/24 04:59:15 cheshire
551 Fixes so that Posix/Linux, OS9, Windows, and VxWorks targets build again
553 Revision 1.137 2004/01/24 03:40:56 cheshire
554 Move mDNSAddrIsDNSMulticast() from DNSCommon.h to mDNSEmbeddedAPI.h so clients can use it
556 Revision 1.136 2004/01/24 03:38:27 cheshire
557 Fix minor syntactic error: Headers should use "extern" declarations, not "mDNSexport"
559 Revision 1.135 2004/01/23 23:23:15 ksekar
560 Added TCP support for truncated unicast messages.
562 Revision 1.134 2004/01/22 03:54:11 cheshire
563 Create special meta-interface 'mDNSInterface_ForceMCast' (-2),
564 which means "do this query via multicast, even if it's apparently a unicast domain"
566 Revision 1.133 2004/01/22 03:48:41 cheshire
567 Make sure uDNS client doesn't accidentally use query ID zero
569 Revision 1.132 2004/01/22 03:43:08 cheshire
570 Export constants like mDNSInterface_LocalOnly so that the client layers can use them
572 Revision 1.131 2004/01/21 21:53:18 cheshire
573 <rdar://problem/3448144>: Don't try to receive unicast responses if we're not the first to bind to the UDP port
575 Revision 1.130 2003/12/14 05:05:29 cheshire
576 Add comments explaining mDNS_Init_NoCache and mDNS_Init_ZeroCacheSize
578 Revision 1.129 2003/12/13 03:05:27 ksekar
579 <rdar://problem/3192548>: DynDNS: Unicast query of service records
581 Revision 1.128 2003/12/01 21:44:23 cheshire
582 Add mStatus_BadInterfaceErr = -65552 for consistency with dns_sd.h
584 Revision 1.127 2003/12/01 18:26:37 cheshire
585 Also pack the OpaqueXX union types. Otherwise, on some systems, mDNSOpaque16 is four bytes!
587 Revision 1.126 2003/12/01 18:23:48 cheshire
588 <rdar://problem/3464646>: Scalar size problem in mDNS code on some 64-bit architectures
590 Revision 1.125 2003/11/22 00:18:27 cheshire
591 Add compile-time asserts to verify correct sizes of mDNSu32, mDNSOpaque16, etc.
593 Revision 1.124 2003/11/20 22:59:54 cheshire
594 Changed runtime checks in mDNS.c to be compile-time checks in mDNSEmbeddedAPI.h
595 Thanks to Bob Bradley for suggesting the ingenious compiler trick to make this work.
597 Revision 1.123 2003/11/20 22:53:01 cheshire
598 Add comment about MAX_ESCAPED_DOMAIN_LABEL
600 Revision 1.122 2003/11/20 20:49:53 cheshire
601 Another fix from HP: Use packedstruct macro to ensure proper packing for on-the-wire packet structures
603 Revision 1.121 2003/11/20 05:01:38 cheshire
604 Update comments; add explanation of Advertise/DontAdvertiseLocalAddresses
606 Revision 1.120 2003/11/14 20:59:08 cheshire
607 Clients can't use AssignDomainName macro because mDNSPlatformMemCopy is defined in mDNSPlatformFunctions.h.
608 Best solution is just to combine mDNSEmbeddedAPI.h and mDNSPlatformFunctions.h into a single file.
610 Revision 1.119 2003/11/14 19:47:52 cheshire
611 Define symbol MAX_ESCAPED_DOMAIN_NAME to indicate recommended buffer size for ConvertDomainNameToCString
613 Revision 1.118 2003/11/14 19:18:34 cheshire
614 Move AssignDomainName macro to mDNSEmbeddedAPI.h to that client layers can use it too
616 Revision 1.117 2003/11/08 23:32:24 cheshire
617 Gave name to anonymous struct, to avoid errors on certain compilers.
618 (Thanks to ramaprasad.kr@hp.com for reporting this.)
620 Revision 1.116 2003/11/07 03:32:56 cheshire
621 <rdar://problem/3472153> mDNSResponder delivers answers in inconsistent order
622 This is the real fix. Checkin 1.312 was overly simplistic; Calling GetFreeCacheRR() can sometimes
623 purge records from the cache, causing tail pointer *rp to be stale on return. The correct fix is
624 to maintain a system-wide tail pointer for each cache slot, and then if neccesary GetFreeCacheRR()
625 can update this pointer, so that mDNSCoreReceiveResponse() appends records in the right place.
627 Revision 1.115 2003/09/23 00:53:54 cheshire
628 NumFailedProbes should be unsigned
630 Revision 1.114 2003/08/29 19:44:15 cheshire
631 <rdar://problem/3400967> Traffic reduction: Eliminate synchronized QUs when a new service appears
632 1. Use m->RandomQueryDelay to impose a random delay in the range 0-500ms on queries
633 that already have at least one unique answer in the cache
634 2. For these queries, go straight to QM, skipping QU
636 Revision 1.113 2003/08/21 19:31:58 cheshire
637 Cosmetic: Swap order of fields
639 Revision 1.112 2003/08/21 19:27:36 cheshire
640 <rdar://problem/3387878> Traffic reduction: No need to announce record for longer than TTL
642 Revision 1.111 2003/08/21 02:21:50 cheshire
643 <rdar://problem/3386473> Efficiency: Reduce repeated queries
645 Revision 1.110 2003/08/20 23:39:31 cheshire
646 <rdar://problem/3344098> Review syslog messages, and remove as appropriate
648 Revision 1.109 2003/08/19 22:24:10 cheshire
651 Revision 1.108 2003/08/19 22:20:00 cheshire
652 <rdar://problem/3376721> Don't use IPv6 on interfaces that have a routable IPv4 address configured
653 More minor refinements
655 Revision 1.107 2003/08/19 06:48:25 cheshire
656 <rdar://problem/3376552> Guard against excessive record updates
657 Each record starts with 10 UpdateCredits.
658 Every update consumes one UpdateCredit.
659 UpdateCredits are replenished at a rate of one one per minute, up to a maximum of 10.
660 As the number of UpdateCredits declines, the number of announcements is similarly scaled back.
661 When fewer than 5 UpdateCredits remain, the first announcement is also delayed by an increasing amount.
663 Revision 1.106 2003/08/19 04:49:28 cheshire
664 <rdar://problem/3368159> Interaction between v4, v6 and dual-stack hosts not working quite right
665 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.
666 2. When we see the first v4 (or first v6) member of a group, we re-trigger questions and probes on that interface.
667 3. When we see the last v4 (or v6) member of a group go away, we revalidate all the records received on that interface.
669 Revision 1.105 2003/08/19 02:33:37 cheshire
672 Revision 1.104 2003/08/19 02:31:11 cheshire
673 <rdar://problem/3378386> mDNSResponder overenthusiastic with final expiration queries
674 Final expiration queries now only mark the question for sending on the particular interface
675 pertaining to the record that's expiring.
677 Revision 1.103 2003/08/18 19:05:44 cheshire
678 <rdar://problem/3382423> UpdateRecord not working right
679 Added "newrdlength" field to hold new length of updated rdata
681 Revision 1.102 2003/08/16 03:39:00 cheshire
682 <rdar://problem/3338440> InterfaceID -1 indicates "local only"
684 Revision 1.101 2003/08/15 20:16:02 cheshire
685 <rdar://problem/3366590> mDNSResponder takes too much RPRVT
686 We want to avoid touching the rdata pages, so we don't page them in.
687 1. RDLength was stored with the rdata, which meant touching the page just to find the length.
688 Moved this from the RData to the ResourceRecord object.
689 2. To avoid unnecessarily touching the rdata just to compare it,
690 compute a hash of the rdata and store the hash in the ResourceRecord object.
692 Revision 1.100 2003/08/14 19:29:04 cheshire
693 <rdar://problem/3378473> Include cache records in SIGINFO output
694 Moved declarations of DNSTypeName() and GetRRDisplayString to mDNSEmbeddedAPI.h so daemon.c can use them
696 Revision 1.99 2003/08/14 02:17:05 cheshire
697 <rdar://problem/3375491> Split generic ResourceRecord type into two separate types: AuthRecord and CacheRecord
699 Revision 1.98 2003/08/12 19:56:23 cheshire
702 Revision 1.97 2003/08/12 14:59:27 cheshire
703 <rdar://problem/3374490> Rate-limiting blocks some legitimate responses
704 When setting LastMCTime also record LastMCInterface. When checking LastMCTime to determine
705 whether to suppress the response, also check LastMCInterface to see if it matches.
707 Revision 1.96 2003/08/12 13:57:04 cheshire
708 <rdar://problem/3323817> Improve cache performance
709 Changed the number of hash table slots from 37 to 499
711 Revision 1.95 2003/08/09 00:55:02 cheshire
712 <rdar://problem/3366553> mDNSResponder is taking 20-30% of the CPU
713 Don't scan the whole cache after every packet.
715 Revision 1.94 2003/08/09 00:35:29 cheshire
717 Revision 1.93 2003/08/08 18:55:48 cheshire
718 <rdar://problem/3370365> Guard against time going backwards
720 Revision 1.92 2003/08/08 18:36:04 cheshire
721 <rdar://problem/3344154> Only need to revalidate on interface removal on platforms that have the PhantomInterfaces bug
723 Revision 1.91 2003/08/06 21:33:39 cheshire
724 Fix compiler warnings on PocketPC 2003 (Windows CE)
726 Revision 1.90 2003/08/06 20:30:17 cheshire
727 Add structure definition for rdataMX (not currently used, but good to have it for completeness)
729 Revision 1.89 2003/08/06 18:58:19 cheshire
732 Revision 1.88 2003/07/24 23:45:44 cheshire
733 To eliminate compiler warnings, changed definition of mDNSBool from
734 "unsigned char" to "int", since "int" is in fact truly the type that C uses
735 for the result of comparison operators (a<b) and logical operators (a||b)
737 Revision 1.87 2003/07/22 23:57:20 cheshire
738 Move platform-layer function prototypes from mDNSEmbeddedAPI.h to mDNSPlatformFunctions.h where they belong
740 Revision 1.86 2003/07/20 03:52:02 ksekar
741 <rdar://problem/3320722>: Feature: New DNS-SD APIs (#7875) (mDNSResponder component)
742 Added error type for incompatibility between daemon and client versions
744 Revision 1.85 2003/07/19 03:23:13 cheshire
745 <rdar://problem/2986147> mDNSResponder needs to receive and cache larger records
747 Revision 1.84 2003/07/18 23:52:12 cheshire
748 To improve consistency of field naming, global search-and-replace:
749 NextProbeTime -> NextScheduledProbe
750 NextResponseTime -> NextScheduledResponse
752 Revision 1.83 2003/07/18 00:29:59 cheshire
753 <rdar://problem/3268878> Remove mDNSResponder version from packet header and use HINFO record instead
755 Revision 1.82 2003/07/17 17:35:04 cheshire
756 <rdar://problem/3325583> Rate-limit responses, to guard against packet flooding
758 Revision 1.81 2003/07/16 05:01:36 cheshire
759 Add fields 'LargeAnswers' and 'ExpectUnicastResponse' in preparation for
760 <rdar://problem/3315761> Need to implement "unicast response" request, using top bit of qclass
762 Revision 1.80 2003/07/15 01:55:12 cheshire
763 <rdar://problem/3315777> Need to implement service registration with subtypes
765 Revision 1.79 2003/07/13 02:28:00 cheshire
766 <rdar://problem/3325166> SendResponses didn't all its responses
767 Delete all references to RRInterfaceActive -- it's now superfluous
769 Revision 1.78 2003/07/13 01:47:53 cheshire
770 Fix one error and one warning in the Windows build
772 Revision 1.77 2003/07/11 01:32:38 cheshire
773 Syntactic cleanup (no change to funcationality): Now that we only have one host name,
774 rename field "hostname1" to "hostname", and field "RR_A1" to "RR_A".
776 Revision 1.76 2003/07/11 01:28:00 cheshire
777 <rdar://problem/3161289> No more local.arpa
779 Revision 1.75 2003/07/02 21:19:45 cheshire
780 <rdar://problem/3313413> Update copyright notices, etc., in source code comments
782 Revision 1.74 2003/07/02 02:41:23 cheshire
783 <rdar://problem/2986146> mDNSResponder needs to start with a smaller cache and then grow it as needed
785 Revision 1.73 2003/06/10 04:24:39 cheshire
786 <rdar://problem/3283637> React when we observe other people query unsuccessfully for a record that's in our cache
787 Some additional refinements:
788 Don't try to do this for unicast-response queries
789 better tracking of Qs and KAs in multi-packet KA lists
791 Revision 1.72 2003/06/10 01:46:27 cheshire
792 Add better comments explaining how these data structures are intended to be used from the client layer
794 Revision 1.71 2003/06/07 06:45:05 cheshire
795 <rdar://problem/3283666> No need for multiple machines to all be sending the same queries
797 Revision 1.70 2003/06/07 04:50:53 cheshire
798 <rdar://problem/3283637> React when we observe other people query unsuccessfully for a record that's in our cache
800 Revision 1.69 2003/06/07 04:22:17 cheshire
801 Add MsgBuffer for error log and debug messages
803 Revision 1.68 2003/06/07 01:46:38 cheshire
804 <rdar://problem/3283540> When query produces zero results, call mDNS_Reconfirm() on any antecedent records
806 Revision 1.67 2003/06/07 01:22:14 cheshire
807 <rdar://problem/3283516> mDNSResponder needs an mDNS_Reconfirm() function
809 Revision 1.66 2003/06/07 00:59:43 cheshire
810 <rdar://problem/3283454> Need some randomness to spread queries on the network
812 Revision 1.65 2003/06/06 21:41:11 cheshire
813 For consistency, mDNS_StopQuery() should return an mStatus result, just like all the other mDNSCore routines
815 Revision 1.64 2003/06/06 21:38:55 cheshire
816 Renamed 'NewData' as 'FreshData' (The data may not be new data, just a refresh of data that we
817 already had in our cache. This refreshes our TTL on the data, but the data itself stays the same.)
819 Revision 1.63 2003/06/06 17:20:14 cheshire
820 For clarity, rename question fields name/rrtype/rrclass as qname/qtype/qclass
821 (Global search-and-replace; no functional change to code execution.)
823 Revision 1.62 2003/06/04 01:25:33 cheshire
824 <rdar://problem/3274950> Cannot perform multi-packet known-answer suppression messages
825 Display time interval between first and subsequent queries
827 Revision 1.61 2003/06/03 05:02:16 cheshire
828 <rdar://problem/3277080> Duplicate registrations not handled as efficiently as they should be
830 Revision 1.60 2003/05/31 00:09:49 cheshire
831 <rdar://problem/3274862> Add ability to discover what services are on a network
833 Revision 1.59 2003/05/29 06:11:35 cheshire
834 <rdar://problem/3272214>: Report if there appear to be too many "Resolve" callbacks
836 Revision 1.58 2003/05/29 05:48:06 cheshire
837 Minor fix for when generating printf warnings: mDNS_snprintf arguments are now 3,4
839 Revision 1.57 2003/05/26 03:21:27 cheshire
840 Tidy up address structure naming:
841 mDNSIPAddr => mDNSv4Addr (for consistency with mDNSv6Addr)
842 mDNSAddr.addr.ipv4 => mDNSAddr.ip.v4
843 mDNSAddr.addr.ipv6 => mDNSAddr.ip.v6
845 Revision 1.56 2003/05/26 03:01:27 cheshire
846 <rdar://problem/3268904> sprintf/vsprintf-style functions are unsafe; use snprintf/vsnprintf instead
848 Revision 1.55 2003/05/26 00:47:30 cheshire
849 Comment clarification
851 Revision 1.54 2003/05/24 16:39:48 cheshire
852 <rdar://problem/3268631> SendResponses also needs to handle multihoming better
854 Revision 1.53 2003/05/23 02:15:37 cheshire
855 Fixed misleading use of the term "duplicate suppression" where it should have
856 said "known answer suppression". (Duplicate answer suppression is something
857 different, and duplicate question suppression is yet another thing, so the use
858 of the completely vague term "duplicate suppression" was particularly bad.)
860 Revision 1.52 2003/05/22 02:29:22 cheshire
861 <rdar://problem/2984918> SendQueries needs to handle multihoming better
862 Complete rewrite of SendQueries. Works much better now :-)
864 Revision 1.51 2003/05/21 20:14:55 cheshire
865 Fix comments and warnings
867 Revision 1.50 2003/05/14 07:08:36 cheshire
868 <rdar://problem/3159272> mDNSResponder should be smarter about reconfigurations
869 Previously, when there was any network configuration change, mDNSResponder
870 would tear down the entire list of active interfaces and start again.
871 That was very disruptive, and caused the entire cache to be flushed,
872 and caused lots of extra network traffic. Now it only removes interfaces
873 that have really gone, and only adds new ones that weren't there before.
875 Revision 1.49 2003/05/07 01:49:36 cheshire
876 Remove "const" in ConstructServiceName prototype
878 Revision 1.48 2003/05/07 00:18:44 cheshire
879 Fix typo: "kDNSQClass_Mask" should be "kDNSClass_Mask"
881 Revision 1.47 2003/05/06 00:00:46 cheshire
882 <rdar://problem/3248914> Rationalize naming of domainname manipulation functions
884 Revision 1.46 2003/04/30 20:39:09 cheshire
887 Revision 1.45 2003/04/29 00:40:50 cheshire
888 Fix compiler warnings
890 Revision 1.44 2003/04/26 02:41:56 cheshire
891 <rdar://problem/3241281> Change timenow from a local variable to a structure member
893 Revision 1.43 2003/04/25 01:45:56 cheshire
894 <rdar://problem/3240002> mDNS_RegisterNoSuchService needs to include a host name
896 Revision 1.42 2003/04/15 20:58:31 jgraessl
898 <rdar://problem/3229014> Added a hash to lookup records in the cache.
900 Revision 1.41 2003/04/15 18:09:13 jgraessl
902 <rdar://problem/3228892>
903 Reviewed by: Stuart Cheshire
904 Added code to keep track of when the next cache item will expire so we can
905 call TidyRRCache only when necessary.
907 Revision 1.40 2003/03/29 01:55:19 cheshire
908 <rdar://problem/3212360> mDNSResponder sometimes suffers false self-conflicts when it sees its own packets
909 Solution: Major cleanup of packet timing and conflict handling rules
911 Revision 1.39 2003/03/27 03:30:55 cheshire
912 <rdar://problem/3210018> Name conflicts not handled properly, resulting in memory corruption, and eventual crash
913 Problem was that HostNameCallback() was calling mDNS_DeregisterInterface(), which is not safe in a callback
915 1. Make mDNS_DeregisterInterface() safe to call from a callback
916 2. Make HostNameCallback() use mDNS_DeadvertiseInterface() instead
917 (it never really needed to deregister the interface at all)
919 Revision 1.38 2003/03/15 04:40:36 cheshire
920 Change type called "mDNSOpaqueID" to the more descriptive name "mDNSInterfaceID"
922 Revision 1.37 2003/03/14 21:34:11 cheshire
923 <rdar://problem/3176950> Can't setup and print to Lexmark PS printers via Airport Extreme
924 Increase size of cache rdata from 512 to 768
926 Revision 1.36 2003/03/05 03:38:35 cheshire
927 <rdar://problem/3185731> Bogus error message in console: died or deallocated, but no record of client can be found!
928 Fixed by leaving client in list after conflict, until client explicitly deallocates
930 Revision 1.35 2003/02/21 02:47:54 cheshire
931 <rdar://problem/3099194> mDNSResponder needs performance improvements
932 Several places in the code were calling CacheRRActive(), which searched the entire
933 question list every time, to see if this cache resource record answers any question.
934 Instead, we now have a field "CRActiveQuestion" in the resource record structure
936 Revision 1.34 2003/02/21 01:54:08 cheshire
937 <rdar://problem/3099194> mDNSResponder needs performance improvements
938 Switched to using new "mDNS_Execute" model (see "Implementer Notes.txt")
940 Revision 1.33 2003/02/20 06:48:32 cheshire
941 <rdar://problem/3169535> Xserve RAID needs to do interface-specific registrations
942 Reviewed by: Josh Graessley, Bob Bradley
944 Revision 1.32 2003/01/31 03:35:59 cheshire
945 <rdar://problem/3147097> mDNSResponder sometimes fails to find the correct results
946 When there were *two* active questions in the list, they were incorrectly
947 finding *each other* and *both* being marked as duplicates of another question
949 Revision 1.31 2003/01/29 02:46:37 cheshire
951 A physical interface is identified solely by its InterfaceID (not by IP and type).
952 On a given InterfaceID, mDNSCore may send both v4 and v6 multicasts.
953 In cases where the requested outbound protocol (v4 or v6) is not supported on
954 that InterfaceID, the platform support layer should simply discard that packet.
956 Revision 1.30 2003/01/29 01:47:08 cheshire
957 Rename 'Active' to 'CRActive' or 'InterfaceActive' for improved clarity
959 Revision 1.29 2003/01/28 05:23:43 cheshire
960 <rdar://problem/3147097> mDNSResponder sometimes fails to find the correct results
961 Add 'Active' flag for interfaces
963 Revision 1.28 2003/01/28 01:35:56 cheshire
964 Revise comment about ThisQInterval to reflect new semantics
966 Revision 1.27 2003/01/13 23:49:42 jgraessl
967 Merged changes for the following fixes in to top of tree:
968 <rdar://problem/3086540> computer name changes not handled properly
969 <rdar://problem/3124348> service name changes are not properly handled
970 <rdar://problem/3124352> announcements sent in pairs, failing chattiness test
972 Revision 1.26 2002/12/23 22:13:28 jgraessl
974 Reviewed by: Stuart Cheshire
975 Initial IPv6 support for mDNSResponder.
977 Revision 1.25 2002/09/21 20:44:49 zarzycki
980 Revision 1.24 2002/09/19 23:47:35 cheshire
981 Added mDNS_RegisterNoSuchService() function for assertion of non-existence
982 of a particular named service
984 Revision 1.23 2002/09/19 21:25:34 cheshire
985 mDNS_snprintf() doesn't need to be in a separate file
987 Revision 1.22 2002/09/19 04:20:43 cheshire
988 Remove high-ascii characters that confuse some systems
990 Revision 1.21 2002/09/17 01:06:35 cheshire
991 Change mDNS_AdvertiseLocalAddresses to be a parameter to mDNS_Init()
993 Revision 1.20 2002/09/16 18:41:41 cheshire
994 Merge in license terms from Quinn's copy, in preparation for Darwin release
998 #ifndef __mDNSClientAPI_h
999 #define __mDNSClientAPI_h
1001 #include <stdarg.h> // stdarg.h is required for for va_list support for the mDNS_vsnprintf declaration
1002 #include "mDNSDebug.h"
1008 // ***************************************************************************
1009 // Function scope indicators
1011 // If you see "mDNSlocal" before a function name in a C file, it means the function is not callable outside this file
1013 #define mDNSlocal static
1015 // If you see "mDNSexport" before a symbol in a C file, it means the symbol is exported for use by clients
1016 // For every "mDNSexport" in a C file, there needs to be a corresponding "extern" declaration in some header file
1017 // (When a C file #includes a header file, the "extern" declarations tell the compiler:
1018 // "This symbol exists -- but not necessarily in this C file.")
1023 // ***************************************************************************
1024 // Structure packing macro
1026 // If we're not using GNUC, it's not fatal.
1027 // Most compilers naturally pack the on-the-wire structures correctly anyway, so a plain "struct" is usually fine.
1028 // In the event that structures are not packed correctly, mDNS_Init() will detect this and report an error, so the
1029 // developer will know what's wrong, and can investigate what needs to be done on that compiler to provide proper packing.
1030 #ifndef packedstruct
1031 #if ((__GNUC__ > 2) || ((__GNUC__ == 2) && (__GNUC_MINOR__ >= 9)))
1032 #define packedstruct struct __attribute__((__packed__))
1033 #define packedunion union __attribute__((__packed__))
1035 #define packedstruct struct
1036 #define packedunion union
1040 // ***************************************************************************
1042 #pragma mark - DNS Resource Record class and type constants
1045 typedef enum // From RFC 1035
1047 kDNSClass_IN
= 1, // Internet
1048 kDNSClass_CS
= 2, // CSNET
1049 kDNSClass_CH
= 3, // CHAOS
1050 kDNSClass_HS
= 4, // Hesiod
1051 kDNSClass_NONE
= 254, // Used in DNS UPDATE [RFC 2136]
1053 kDNSClass_Mask
= 0x7FFF,// Multicast DNS uses the bottom 15 bits to identify the record class...
1054 kDNSClass_UniqueRRSet
= 0x8000,// ... and the top bit indicates that all other cached records are now invalid
1056 kDNSQClass_ANY
= 255, // Not a DNS class, but a DNS query class, meaning "all classes"
1057 kDNSQClass_UnicastResponse
= 0x8000 // Top bit set in a question means "unicast response acceptable"
1060 typedef enum // From RFC 1035
1062 kDNSType_A
= 1, // 1 Address
1063 kDNSType_NS
, // 2 Name Server
1064 kDNSType_MD
, // 3 Mail Destination
1065 kDNSType_MF
, // 4 Mail Forwarder
1066 kDNSType_CNAME
, // 5 Canonical Name
1067 kDNSType_SOA
, // 6 Start of Authority
1068 kDNSType_MB
, // 7 Mailbox
1069 kDNSType_MG
, // 8 Mail Group
1070 kDNSType_MR
, // 9 Mail Rename
1071 kDNSType_NULL
, // 10 NULL RR
1072 kDNSType_WKS
, // 11 Well-known-service
1073 kDNSType_PTR
, // 12 Domain name pointer
1074 kDNSType_HINFO
, // 13 Host information
1075 kDNSType_MINFO
, // 14 Mailbox information
1076 kDNSType_MX
, // 15 Mail Exchanger
1077 kDNSType_TXT
, // 16 Arbitrary text string
1079 kDNSType_AAAA
= 28, // 28 IPv6 address
1080 kDNSType_SRV
= 33, // 33 Service record
1081 kDNSType_OPT
= 41, // EDNS0 OPT record
1082 kDNSType_TSIG
= 250, // 250 Transaction Signature
1084 kDNSQType_ANY
= 255 // Not a DNS type, but a DNS query type, meaning "all types"
1087 // ***************************************************************************
1089 #pragma mark - Simple types
1092 // mDNS defines its own names for these common types to simplify portability across
1093 // multiple platforms that may each have their own (different) names for these types.
1094 typedef int mDNSBool
;
1095 typedef signed char mDNSs8
;
1096 typedef unsigned char mDNSu8
;
1097 typedef signed short mDNSs16
;
1098 typedef unsigned short mDNSu16
;
1100 // <http://gcc.gnu.org/onlinedocs/gcc-3.3.3/cpp/Common-Predefined-Macros.html> says
1102 // These macros are defined, with value 1, if (and only if) the compilation is
1103 // for a target where long int and pointer both use 64-bits and int uses 32-bit.
1104 // <http://www.intel.com/software/products/compilers/clin/docs/ug/lin1077.htm> says
1105 // Macro Name __LP64__ Value 1
1106 // A quick Google search for "defined(__LP64__)" OR "#ifdef __LP64__" gives 2590 hits and
1107 // a search for "#if __LP64__" gives only 12, so I think we'll go with the majority and use defined()
1108 #if defined(_LP64) || defined(__LP64__)
1109 typedef signed int mDNSs32
;
1110 typedef unsigned int mDNSu32
;
1111 #elif defined(_ILP64) || defined(__ILP64__)
1112 typedef signed int32 mDNSs32
;
1113 typedef unsigned int32 mDNSu32
;
1115 typedef signed long mDNSs32
;
1116 typedef unsigned long mDNSu32
;
1119 // To enforce useful type checking, we make mDNSInterfaceID be a pointer to a dummy struct
1120 // This way, mDNSInterfaceIDs can be assigned, and compared with each other, but not with other types
1121 // Declaring the type to be the typical generic "void *" would lack this type checking
1122 typedef struct mDNSInterfaceID_dummystruct
{ void *dummy
; } *mDNSInterfaceID
;
1124 // These types are for opaque two- and four-byte identifiers.
1125 // The "NotAnInteger" fields of the unions allow the value to be conveniently passed around in a
1126 // register for the sake of efficiency, and compared for equality or inequality, but don't forget --
1127 // just because it is in a register doesn't mean it is an integer. Operations like greater than,
1128 // less than, add, multiply, increment, decrement, etc., are undefined for opaque identifiers,
1129 // and if you make the mistake of trying to do those using the NotAnInteger field, then you'll
1130 // find you get code that doesn't work consistently on big-endian and little-endian machines.
1131 typedef packedunion
{ mDNSu8 b
[ 2]; mDNSu16 NotAnInteger
; } mDNSOpaque16
;
1132 typedef packedunion
{ mDNSu8 b
[ 4]; mDNSu32 NotAnInteger
; } mDNSOpaque32
;
1133 typedef packedunion
{ mDNSu8 b
[ 6]; mDNSu16 w
[3]; mDNSu32 l
[1]; } mDNSOpaque48
;
1134 typedef packedunion
{ mDNSu8 b
[16]; mDNSu16 w
[8]; mDNSu32 l
[4]; } mDNSOpaque128
;
1136 typedef mDNSOpaque16 mDNSIPPort
; // An IP port is a two-byte opaque identifier (not an integer)
1137 typedef mDNSOpaque32 mDNSv4Addr
; // An IP address is a four-byte opaque identifier (not an integer)
1138 typedef mDNSOpaque128 mDNSv6Addr
; // An IPv6 address is a 16-byte opaque identifier (not an integer)
1139 typedef mDNSOpaque48 mDNSEthAddr
; // An Ethernet address is a six-byte opaque identifier (not an integer)
1143 mDNSAddrType_None
= 0,
1144 mDNSAddrType_IPv4
= 4,
1145 mDNSAddrType_IPv6
= 6,
1146 mDNSAddrType_Unknown
= ~0 // Special marker value used in known answer list recording
1152 union { mDNSv6Addr v6
; mDNSv4Addr v4
; } ip
;
1155 enum { mDNSfalse
= 0, mDNStrue
= 1 };
1161 mStatus_Waiting
= 1,
1162 mStatus_NoError
= 0,
1164 // mDNS return values are in the range FFFE FF00 (-65792) to FFFE FFFF (-65537)
1165 // The top end of the range (FFFE FFFF) is used for error codes;
1166 // the bottom end of the range (FFFE FF00) is used for non-error values;
1169 mStatus_UnknownErr
= -65537, // First value: 0xFFFE FFFF
1170 mStatus_NoSuchNameErr
= -65538,
1171 mStatus_NoMemoryErr
= -65539,
1172 mStatus_BadParamErr
= -65540,
1173 mStatus_BadReferenceErr
= -65541,
1174 mStatus_BadStateErr
= -65542,
1175 mStatus_BadFlagsErr
= -65543,
1176 mStatus_UnsupportedErr
= -65544,
1177 mStatus_NotInitializedErr
= -65545,
1178 mStatus_NoCache
= -65546,
1179 mStatus_AlreadyRegistered
= -65547,
1180 mStatus_NameConflict
= -65548,
1181 mStatus_Invalid
= -65549,
1182 mStatus_Firewall
= -65550,
1183 mStatus_Incompatible
= -65551,
1184 mStatus_BadInterfaceErr
= -65552,
1185 mStatus_Refused
= -65553,
1186 mStatus_NoSuchRecord
= -65554,
1187 mStatus_NoAuth
= -65555,
1188 mStatus_NoSuchKey
= -65556,
1189 mStatus_NATTraversal
= -65557,
1190 mStatus_DoubleNAT
= -65558,
1191 mStatus_BadTime
= -65559,
1192 mStatus_BadSig
= -65560, // while we define this per RFC 2845, BIND 9 returns Refused for bad/missing signatures
1193 mStatus_BadKey
= -65561,
1194 mStatus_TransientErr
= -65562, // transient failures, e.g. sending packets shortly after a network transition or wake from sleep
1195 // -65563 to -65786 currently unused; available for allocation
1197 // tcp connection status
1198 mStatus_ConnPending
= -65787,
1199 mStatus_ConnFailed
= -65788,
1200 mStatus_ConnEstablished
= -65789,
1202 // Non-error values:
1203 mStatus_GrowCache
= -65790,
1204 mStatus_ConfigChanged
= -65791,
1205 mStatus_MemFree
= -65792 // Last value: 0xFFFE FF00
1207 // mStatus_MemFree is the last legal mDNS error code, at the end of the range allocated for mDNS
1210 typedef mDNSs32 mStatus
;
1212 // RFC 1034/1035 specify that a domain label consists of a length byte plus up to 63 characters
1213 #define MAX_DOMAIN_LABEL 63
1214 typedef struct { mDNSu8 c
[ 64]; } domainlabel
; // One label: length byte and up to 63 characters
1216 // RFC 1034/1035 specify that a domain name, including length bytes, data bytes, and terminating zero, may be up to 255 bytes long
1217 #define MAX_DOMAIN_NAME 255
1218 typedef struct { mDNSu8 c
[256]; } domainname
; // Up to 255 bytes of length-prefixed domainlabels
1220 typedef struct { mDNSu8 c
[256]; } UTF8str255
; // Null-terminated C string
1222 // The longest legal textual form of a DNS name is 1005 bytes, including the C-string terminating NULL at the end.
1224 // When a native domainname object is converted to printable textual form using ConvertDomainNameToCString(),
1225 // non-printing characters are represented in the conventional DNS way, as '\ddd', where ddd is a three-digit decimal number.
1226 // The longest legal domain name is 255 bytes, in the form of four labels as shown below:
1227 // Length byte, 63 data bytes, length byte, 63 data bytes, length byte, 63 data bytes, length byte, 61 data bytes, zero byte.
1228 // Each label is encoded textually as characters followed by a trailing dot.
1229 // If every character has to be represented as a four-byte escape sequence, then this makes the maximum textual form four labels
1230 // plus the C-string terminating NULL as shown below:
1231 // 63*4+1 + 63*4+1 + 63*4+1 + 61*4+1 + 1 = 1005.
1232 // Note that MAX_ESCAPED_DOMAIN_LABEL is not normally used: If you're only decoding a single label, escaping is usually not required.
1233 // It is for domain names, where dots are used as label separators, that proper escaping is vital.
1234 #define MAX_ESCAPED_DOMAIN_LABEL 254
1235 #define MAX_ESCAPED_DOMAIN_NAME 1005
1237 // Most records have a TTL of 75 minutes, so that their 80% cache-renewal query occurs once per hour.
1238 // For records containing a hostname (in the name on the left, or in the rdata on the right),
1239 // like A, AAAA, reverse-mapping PTR, and SRV, we use a two-minute TTL by default, because we don't want
1240 // them to hang around for too long in the cache if the host in question crashes or otherwise goes away.
1241 // Wide-area service discovery records have a very short TTL to avoid poluting intermediate caches with
1242 // dynamic records. When discovered via Long Lived Queries (with change notifications), resource record
1243 // TTLs can be safely ignored.
1245 #define kStandardTTL (3600UL * 100 / 80)
1246 #define kHostNameTTL 120UL
1247 #define kWideAreaTTL 3
1249 #define DefaultTTLforRRType(X) (((X) == kDNSType_A || (X) == kDNSType_AAAA || (X) == kDNSType_SRV) ? kHostNameTTL : kStandardTTL)
1251 // ***************************************************************************
1253 #pragma mark - DNS Message structures
1256 #define mDNS_numZones numQuestions
1257 #define mDNS_numPrereqs numAnswers
1258 #define mDNS_numUpdates numAuthorities
1260 typedef packedstruct
1264 mDNSu16 numQuestions
;
1266 mDNSu16 numAuthorities
;
1267 mDNSu16 numAdditionals
;
1270 // We can send and receive packets up to 9000 bytes (Ethernet Jumbo Frame size, if that ever becomes widely used)
1271 // However, in the normal case we try to limit packets to 1500 bytes so that we don't get IP fragmentation on standard Ethernet
1272 // 40 (IPv6 header) + 8 (UDP header) + 12 (DNS message header) + 1440 (DNS message body) = 1500 total
1273 #define AbsoluteMaxDNSMessageData 8940
1274 #define NormalMaxDNSMessageData 1440
1275 typedef packedstruct
1277 DNSMessageHeader h
; // Note: Size 12 bytes
1278 mDNSu8 data
[AbsoluteMaxDNSMessageData
]; // 40 (IPv6) + 8 (UDP) + 12 (DNS header) + 8940 (data) = 9000
1281 // ***************************************************************************
1283 #pragma mark - Resource Record structures
1286 // Authoritative Resource Records:
1287 // There are four basic types: Shared, Advisory, Unique, Known Unique
1289 // * Shared Resource Records do not have to be unique
1290 // -- Shared Resource Records are used for DNS-SD service PTRs
1291 // -- It is okay for several hosts to have RRs with the same name but different RDATA
1292 // -- We use a random delay on responses to reduce collisions when all the hosts respond to the same query
1293 // -- These RRs typically have moderately high TTLs (e.g. one hour)
1294 // -- These records are announced on startup and topology changes for the benefit of passive listeners
1295 // -- These records send a goodbye packet when deregistering
1297 // * Advisory Resource Records are like Shared Resource Records, except they don't send a goodbye packet
1299 // * Unique Resource Records should be unique among hosts within any given mDNS scope
1300 // -- The majority of Resource Records are of this type
1301 // -- If two entities on the network have RRs with the same name but different RDATA, this is a conflict
1302 // -- Responses may be sent immediately, because only one host should be responding to any particular query
1303 // -- These RRs typically have low TTLs (e.g. a few minutes)
1304 // -- On startup and after topology changes, a host issues queries to verify uniqueness
1306 // * Known Unique Resource Records are treated like Unique Resource Records, except that mDNS does
1307 // not have to verify their uniqueness because this is already known by other means (e.g. the RR name
1308 // is derived from the host's IP or Ethernet address, which is already known to be a unique identifier).
1310 // Summary of properties of different record types:
1311 // Probe? Does this record type send probes before announcing?
1312 // Conflict? Does this record type react if we observe an apparent conflict?
1313 // Goodbye? Does this record type send a goodbye packet on departure?
1315 // Probe? Conflict? Goodbye? Notes
1316 // Unregistered Should not appear in any list (sanity check value)
1317 // Shared No No Yes e.g. Service PTR record
1318 // Deregistering No No Yes Shared record about to announce its departure and leave the list
1319 // Advisory No No No
1320 // Unique Yes Yes No Record intended to be unique -- will probe to verify
1321 // Verified Yes Yes No Record has completed probing, and is verified unique
1322 // KnownUnique No Yes No Record is assumed by other means to be unique
1324 // Valid lifecycle of a record:
1325 // Unregistered -> Shared -> Deregistering -(goodbye)-> Unregistered
1326 // Unregistered -> Advisory -> Unregistered
1327 // Unregistered -> Unique -(probe)-> Verified -> Unregistered
1328 // Unregistered -> KnownUnique -> Unregistered
1330 // Each Authoritative kDNSRecordType has only one bit set. This makes it easy to quickly see if a record
1331 // is one of a particular set of types simply by performing the appropriate bitwise masking operation.
1333 // Cache Resource Records (received from the network):
1334 // There are four basic types: Answer, Unique Answer, Additional, Unique Additional
1335 // Bit 7 (the top bit) of kDNSRecordType is always set for Cache Resource Records; always clear for Authoritative Resource Records
1336 // Bit 6 (value 0x40) is set for answer records; clear for additional records
1337 // Bit 5 (value 0x20) is set for records received with the kDNSClass_UniqueRRSet
1341 kDNSRecordTypeUnregistered
= 0x00, // Not currently in any list
1342 kDNSRecordTypeDeregistering
= 0x01, // Shared record about to announce its departure and leave the list
1344 kDNSRecordTypeUnique
= 0x02, // Will become a kDNSRecordTypeVerified when probing is complete
1346 kDNSRecordTypeAdvisory
= 0x04, // Like Shared, but no goodbye packet
1347 kDNSRecordTypeShared
= 0x08, // Shared means record name does not have to be unique -- use random delay on responses
1349 kDNSRecordTypeVerified
= 0x10, // Unique means mDNS should check that name is unique (and then send immediate responses)
1350 kDNSRecordTypeKnownUnique
= 0x20, // Known Unique means mDNS can assume name is unique without checking
1351 // For Dynamic Update records, Known Unique means the record must already exist on the server.
1352 kDNSRecordTypeUniqueMask
= (kDNSRecordTypeUnique
| kDNSRecordTypeVerified
| kDNSRecordTypeKnownUnique
),
1353 kDNSRecordTypeActiveMask
= (kDNSRecordTypeAdvisory
| kDNSRecordTypeShared
| kDNSRecordTypeVerified
| kDNSRecordTypeKnownUnique
),
1355 kDNSRecordTypePacketAdd
= 0x80, // Received in the Additional Section of a DNS Response
1356 kDNSRecordTypePacketAddUnique
= 0x90, // Received in the Additional Section of a DNS Response with kDNSClass_UniqueRRSet set
1357 kDNSRecordTypePacketAuth
= 0xA0, // Received in the Authorities Section of a DNS Response
1358 kDNSRecordTypePacketAuthUnique
= 0xB0, // Received in the Authorities Section of a DNS Response with kDNSClass_UniqueRRSet set
1359 kDNSRecordTypePacketAns
= 0xC0, // Received in the Answer Section of a DNS Response
1360 kDNSRecordTypePacketAnsUnique
= 0xD0, // Received in the Answer Section of a DNS Response with kDNSClass_UniqueRRSet set
1362 kDNSRecordTypePacketAnsMask
= 0x40, // True for PacketAns and PacketAnsUnique
1363 kDNSRecordTypePacketUniqueMask
= 0x10 // True for PacketAddUnique, PacketAnsUnique, PacketAuthUnique
1366 typedef packedstruct
{ mDNSu16 priority
; mDNSu16 weight
; mDNSIPPort port
; domainname target
; } rdataSRV
;
1367 typedef packedstruct
{ mDNSu16 preference
; domainname exchange
; } rdataMX
;
1368 typedef packedstruct
1372 mDNSs32 serial
; // Modular counter; increases when zone changes
1373 mDNSu32 refresh
; // Time in seconds that a slave waits after successful replication of the database before it attempts replication again
1374 mDNSu32 retry
; // Time in seconds that a slave waits after an unsuccessful replication attempt before it attempts replication again
1375 mDNSu32 expire
; // Time in seconds that a slave holds on to old data while replication attempts remain unsuccessful
1376 mDNSu32 min
; // Nominally the minimum record TTL for this zone, in seconds; also used for negative caching.
1379 typedef packedstruct
1388 #define LLQ_OPTLEN ((3 * sizeof(mDNSu16)) + 8 + sizeof(mDNSu32))
1389 // Windows adds pad bytes to sizeof(LLQOptData). Use this macro when setting length fields or validating option rdata from
1390 // off the wire. Use sizeof(LLQOptData) when dealing with structures (e.g. memcpy). Never memcpy between on-the-wire
1391 // representation and a structure
1393 // NOTE: rdataOpt format may be repeated an arbitrary number of times in a single resource record
1394 typedef packedstruct
1398 union { LLQOptData llq
; mDNSu32 lease
; } OptData
;
1401 // StandardAuthRDSize is 264 (256+8), which is large enough to hold a maximum-sized SRV record
1402 // MaximumRDSize is 8K the absolute maximum we support (at least for now)
1403 #define StandardAuthRDSize 264
1404 #define MaximumRDSize 8192
1406 // InlineCacheRDSize is 68
1407 // Records received from the network with rdata this size or less have their rdata stored right in the CacheRecord object
1408 // Records received from the network with rdata larger than this have additional storage allocated for the rdata
1409 // A quick unscientific sample from a busy network at Apple with lots of machines revealed this:
1410 // 1461 records in cache
1411 // 292 were one-byte TXT records
1412 // 136 were four-byte A records
1413 // 184 were sixteen-byte AAAA records
1414 // 780 were various PTR, TXT and SRV records from 12-64 bytes
1415 // Only 69 records had rdata bigger than 64 bytes
1416 // Note that since CacheRecord object and a CacheGroup object are allocated out of the same pool, it's sensible to
1417 // have them both be the same size. Making one smaller without making the other smaller won't actually save any memory.
1418 #define InlineCacheRDSize 68
1420 #define InlineCacheGroupNameSize 144
1424 mDNSu8 data
[StandardAuthRDSize
];
1425 mDNSv4Addr ipv4
; // For 'A' record
1426 mDNSv6Addr ipv6
; // For 'AAAA' record
1427 domainname name
; // For PTR, NS, and CNAME records
1428 UTF8str255 txt
; // For TXT record
1429 rdataSRV srv
; // For SRV record
1430 rdataMX mx
; // For MX record
1431 rdataSOA soa
; // For SOA record
1432 rdataOpt opt
; // For eDNS0 opt record
1437 mDNSu16 MaxRDLength
; // Amount of storage allocated for rdata (usually sizeof(RDataBody))
1440 #define sizeofRDataHeader (sizeof(RData) - sizeof(RDataBody))
1442 typedef struct AuthRecord_struct AuthRecord
;
1443 typedef struct CacheRecord_struct CacheRecord
;
1444 typedef struct CacheGroup_struct CacheGroup
;
1445 typedef struct DNSQuestion_struct DNSQuestion
;
1446 typedef struct mDNS_struct mDNS
;
1447 typedef struct mDNS_PlatformSupport_struct mDNS_PlatformSupport
;
1448 typedef struct NATTraversalInfo_struct NATTraversalInfo
;
1450 // Note: Within an mDNSRecordCallback mDNS all API calls are legal except mDNS_Init(), mDNS_Close(), mDNS_Execute()
1451 typedef void mDNSRecordCallback(mDNS
*const m
, AuthRecord
*const rr
, mStatus result
);
1454 // Restrictions: An mDNSRecordUpdateCallback may not make any mDNS API calls.
1455 // The intent of this callback is to allow the client to free memory, if necessary.
1456 // The internal data structures of the mDNS code may not be in a state where mDNS API calls may be made safely.
1457 typedef void mDNSRecordUpdateCallback(mDNS
*const m
, AuthRecord
*const rr
, RData
*OldRData
);
1461 mDNSu8 RecordType
; // See enum above
1462 mDNSInterfaceID InterfaceID
; // Set if this RR is specific to one interface
1463 // For records received off the wire, InterfaceID is *always* set to the receiving interface
1464 // For our authoritative records, InterfaceID is usually zero, except for those few records
1465 // that are interface-specific (e.g. address records, especially linklocal addresses)
1469 mDNSu32 rroriginalttl
; // In seconds
1470 mDNSu16 rdlength
; // Size of the raw rdata, in bytes
1471 mDNSu16 rdestimate
; // Upper bound on size of rdata after name compression
1472 mDNSu32 namehash
; // Name-based (i.e. case-insensitive) hash of name
1473 mDNSu32 rdatahash
; // For rdata containing domain name (e.g. PTR, SRV, CNAME etc.), case-insensitive name hash
1474 // else, for all other rdata, 32-bit hash of the raw rdata
1475 // Note: This requirement is important. Various routines like AddAdditionalsToResponseList(),
1476 // ReconfirmAntecedents(), etc., use rdatahash as a pre-flight check to see
1477 // whether it's worth doing a full SameDomainName() call. If the rdatahash
1478 // is not a correct case-insensitive name hash, they'll get false negatives.
1479 RData
*rdata
; // Pointer to storage for this rdata
1482 // Unless otherwise noted, states may apply to either independent record registrations or service registrations
1485 regState_FetchingZoneData
= 1, // getting info - update not sent
1486 regState_Pending
= 2, // update sent, reply not received
1487 regState_Registered
= 3, // update sent, reply received
1488 regState_DeregPending
= 4, // dereg sent, reply not received
1489 regState_DeregDeferred
= 5, // dereg requested while in Pending state - send dereg AFTER registration is confirmed
1490 regState_Cancelled
= 6, // update not sent, reg. cancelled by client
1491 regState_Unregistered
= 8, // not in any list
1492 regState_Refresh
= 9, // outstanding refresh (or target change) message
1493 regState_NATMap
= 10, // establishing NAT port mapping or learning public address
1494 regState_UpdatePending
= 11, // update in flight as result of mDNS_Update call
1495 regState_NoTarget
= 12, // service registration pending registration of hostname (ServiceRegistrations only)
1496 regState_ExtraQueued
= 13, // extra record to be registered upon completion of service registration (RecordRegistrations only)
1497 regState_NATError
= 14 // unable to complete NAT traversal
1500 // context for both ServiceRecordSet and individual AuthRec structs
1503 // registration/lease state
1505 mDNSBool lease
; // dynamic update contains (should contain) lease option
1506 mDNSs32 expire
; // expiration of lease (-1 for static)
1507 mDNSBool TestForSelfConflict
; // on name conflict, check if we're just seeing our own orphaned records
1509 // identifier to match update request and response
1513 domainname zone
; // the zone that is updated
1514 mDNSAddr ns
; // primary name server for the record's zone !!!KRS not technically correct to cache longer than TTL
1515 mDNSIPPort port
; // port on which server accepts dynamic updates
1517 // NAT traversal context
1518 NATTraversalInfo
*NATinfo
; // may be NULL
1520 // state for deferred operations
1521 mDNSBool ClientCallbackDeferred
; // invoke client callback on completion of pending operation(s)
1522 mStatus DeferredStatus
; // status to deliver when above flag is set
1523 mDNSBool SRVUpdateDeferred
; // do we need to change target or port once current operation completes?
1524 mDNSBool SRVChanged
; // temporarily deregistered service because its SRV target or port changed
1526 // uDNS_UpdateRecord support fields
1527 RData
*OrigRData
; mDNSu16 OrigRDLen
; // previously registered, being deleted
1528 RData
*InFlightRData
; mDNSu16 InFlightRDLen
; // currently being registered
1529 RData
*QueuedRData
; mDNSu16 QueuedRDLen
; // if the client call Update while an update is in flight, we must finish the
1530 // pending operation (re-transmitting if necessary) THEN register the queued update
1531 mDNSRecordUpdateCallback
*UpdateRDCallback
; // client callback to free old rdata
1534 struct AuthRecord_struct
1536 // For examples of how to set up this structure for use in mDNS_Register(),
1537 // see mDNS_AdvertiseInterface() or mDNS_RegisterService().
1538 // Basically, resrec and persistent metadata need to be set up before calling mDNS_Register().
1539 // mDNS_SetupResourceRecord() is avaliable as a helper routine to set up most fields to sensible default values for you
1541 AuthRecord
*next
; // Next in list; first element of structure for efficiency reasons
1542 // Field Group 1: Common ResourceRecord fields
1543 ResourceRecord resrec
;
1544 uDNS_RegInfo uDNS_info
;
1546 // Field Group 2: Persistent metadata for Authoritative Records
1547 AuthRecord
*Additional1
; // Recommended additional record to include in response
1548 AuthRecord
*Additional2
; // Another additional
1549 AuthRecord
*DependentOn
; // This record depends on another for its uniqueness checking
1550 AuthRecord
*RRSet
; // This unique record is part of an RRSet
1551 mDNSRecordCallback
*RecordCallback
; // Callback function to call for state changes, and to free memory asynchronously on deregistration
1552 void *RecordContext
; // Context parameter for the callback function
1553 mDNSu8 HostTarget
; // Set if the target of this record (PTR, CNAME, SRV, etc.) is our host name
1554 mDNSu8 AllowRemoteQuery
; // Set if we allow hosts not on the local link to query this record
1555 mDNSu8 ForceMCast
; // Set by client to advertise solely via multicast, even for apparently unicast names
1557 // Field Group 3: Transient state for Authoritative Records
1558 mDNSu8 Acknowledged
; // Set if we've given the success callback to the client
1559 mDNSu8 ProbeCount
; // Number of probes remaining before this record is valid (kDNSRecordTypeUnique)
1560 mDNSu8 AnnounceCount
; // Number of announcements remaining (kDNSRecordTypeShared)
1561 mDNSu8 RequireGoodbye
; // Set if this RR has been announced on the wire and will require a goodbye packet
1562 mDNSu8 LocalAnswer
; // Set if this RR has been delivered to LocalOnly questions
1563 mDNSu8 IncludeInProbe
; // Set if this RR is being put into a probe right now
1564 mDNSInterfaceID ImmedAnswer
; // Someone on this interface issued a query we need to answer (all-ones for all interfaces)
1565 mDNSu8 ImmedUnicast
; // Set if we may send our response directly via unicast to the requester
1566 #if MDNS_LOG_ANSWER_SUPPRESSION_TIMES
1567 mDNSs32 ImmedAnswerMarkTime
;
1569 mDNSInterfaceID ImmedAdditional
; // Hint that we might want to also send this record, just to be helpful
1570 mDNSInterfaceID SendRNow
; // The interface this query is being sent on right now
1571 mDNSv4Addr v4Requester
; // Recent v4 query for this record, or all-ones if more than one recent query
1572 mDNSv6Addr v6Requester
; // Recent v6 query for this record, or all-ones if more than one recent query
1573 AuthRecord
*NextResponse
; // Link to the next element in the chain of responses to generate
1574 const mDNSu8
*NR_AnswerTo
; // Set if this record was selected by virtue of being a direct answer to a question
1575 AuthRecord
*NR_AdditionalTo
; // Set if this record was selected by virtue of being additional to another
1576 mDNSs32 ThisAPInterval
; // In platform time units: Current interval for announce/probe
1577 mDNSs32 AnnounceUntil
; // In platform time units: Creation time + TTL
1578 mDNSs32 LastAPTime
; // In platform time units: Last time we sent announcement/probe
1579 mDNSs32 LastMCTime
; // Last time we multicast this record (used to guard against packet-storm attacks)
1580 mDNSInterfaceID LastMCInterface
; // Interface this record was multicast on at the time LastMCTime was recorded
1581 RData
*NewRData
; // Set if we are updating this record with new rdata
1582 mDNSu16 newrdlength
; // ... and the length of the new RData
1583 mDNSRecordUpdateCallback
*UpdateCallback
;
1584 mDNSu32 UpdateCredits
; // Token-bucket rate limiting of excessive updates
1585 mDNSs32 NextUpdateCredit
; // Time next token is added to bucket
1586 mDNSs32 UpdateBlocked
; // Set if update delaying is in effect
1588 domainname namestorage
;
1589 RData rdatastorage
; // Normally the storage is right here, except for oversized records
1590 // rdatastorage MUST be the last thing in the structure -- when using oversized AuthRecords, extra bytes
1591 // are appended after the end of the AuthRecord, logically augmenting the size of the rdatastorage
1592 // DO NOT ADD ANY MORE FIELDS HERE
1595 // Wrapper struct for Auth Records for higher-level code that cannot use the AuthRecord's ->next pointer field
1596 typedef struct ARListElem
1598 struct ARListElem
*next
;
1599 AuthRecord ar
; // Note: Must be last struct in field to accomodate oversized AuthRecords
1602 struct CacheGroup_struct
// Header object for a list of CacheRecords with the same name
1604 CacheGroup
*next
; // Next CacheGroup object in this hash table bucket
1605 mDNSu32 namehash
; // Name-based (i.e. case insensitive) hash of name
1606 CacheRecord
*members
; // List of CacheRecords with this same name
1607 CacheRecord
**rrcache_tail
; // Tail end of that list
1608 domainname
*name
; // Common name for all CacheRecords in this list
1609 mDNSu8 namestorage
[InlineCacheGroupNameSize
];
1612 struct CacheRecord_struct
1614 CacheRecord
*next
; // Next in list; first element of structure for efficiency reasons
1615 ResourceRecord resrec
;
1617 // Transient state for Cache Records
1618 CacheRecord
*NextInKAList
; // Link to the next element in the chain of known answers to send
1619 mDNSs32 TimeRcvd
; // In platform time units
1620 mDNSs32 DelayDelivery
; // Set if we want to defer delivery of this answer to local clients
1621 mDNSs32 NextRequiredQuery
; // In platform time units
1622 mDNSs32 LastUsed
; // In platform time units
1623 DNSQuestion
*CRActiveQuestion
; // Points to an active question referencing this answer
1624 mDNSu32 UnansweredQueries
; // Number of times we've issued a query for this record without getting an answer
1625 mDNSs32 LastUnansweredTime
; // In platform time units; last time we incremented UnansweredQueries
1626 mDNSu32 MPUnansweredQ
; // Multi-packet query handling: Number of times we've seen a query for this record
1627 mDNSs32 MPLastUnansweredQT
; // Multi-packet query handling: Last time we incremented MPUnansweredQ
1628 mDNSu32 MPUnansweredKA
; // Multi-packet query handling: Number of times we've seen this record in a KA list
1629 mDNSBool MPExpectingKA
; // Multi-packet query handling: Set when we increment MPUnansweredQ; allows one KA
1630 CacheRecord
*NextInCFList
; // Set if this is in the list of records we just received with the cache flush bit set
1632 struct { mDNSu16 MaxRDLength
; mDNSu8 data
[InlineCacheRDSize
]; } rdatastorage
; // Storage for small records is right here
1635 // Storage sufficient to hold either a CacheGroup header or a CacheRecord
1636 typedef union CacheEntity_union CacheEntity
;
1637 union CacheEntity_union
{ CacheEntity
*next
; CacheGroup cg
; CacheRecord cr
; };
1642 mDNSu8 _extradata
[MaximumRDSize
-InlineCacheRDSize
]; // Glue on the necessary number of extra bytes
1643 domainname namestorage
; // Needs to go *after* the extra rdata bytes
1646 typedef struct uDNS_HostnameInfo
1648 struct uDNS_HostnameInfo
*next
;
1650 AuthRecord
*arv4
; // registered IPv4 address record
1651 AuthRecord
*arv6
; // registered IPv6 address record
1652 mDNSRecordCallback
*StatusCallback
; // callback to deliver success or error code to client layer
1653 const void *StatusContext
; // Client Context
1654 } uDNS_HostnameInfo
;
1658 DNSServer_Untested
= 0,
1659 DNSServer_Failed
= 1,
1660 DNSServer_Passed
= 2
1663 typedef struct DNSServer
1665 struct DNSServer
*next
;
1667 mDNSBool del
; // Set when we're planning to delete this from the list
1668 mDNSu32 teststate
; // Have we sent bug-detection query to this server?
1669 domainname domain
; // name->server matching for "split dns"
1672 typedef struct NetworkInterfaceInfo_struct NetworkInterfaceInfo
;
1674 // A NetworkInterfaceInfo_struct serves two purposes:
1675 // 1. It holds the address, PTR and HINFO records to advertise a given IP address on a given physical interface
1676 // 2. It tells mDNSCore which physical interfaces are available; each physical interface has its own unique InterfaceID.
1677 // Since there may be multiple IP addresses on a single physical interface,
1678 // there may be multiple NetworkInterfaceInfo_structs with the same InterfaceID.
1679 // In this case, to avoid sending the same packet n times, when there's more than one
1680 // struct with the same InterfaceID, mDNSCore picks one member of the set to be the
1681 // active representative of the set; all others have the 'InterfaceActive' flag unset.
1683 struct NetworkInterfaceInfo_struct
1685 // Internal state fields. These are used internally by mDNSCore; the client layer needn't be concerned with them.
1686 NetworkInterfaceInfo
*next
;
1688 mDNSBool InterfaceActive
; // Set if interface is sending & receiving packets (see comment above)
1689 mDNSBool IPv4Available
; // If InterfaceActive, set if v4 available on this InterfaceID
1690 mDNSBool IPv6Available
; // If InterfaceActive, set if v6 available on this InterfaceID
1692 // Standard AuthRecords that every Responder host should have (one per active IP address)
1693 AuthRecord RR_A
; // 'A' or 'AAAA' (address) record for our ".local" name
1694 AuthRecord RR_PTR
; // PTR (reverse lookup) record
1695 AuthRecord RR_HINFO
;
1697 // Client API fields: The client must set up these fields *before* calling mDNS_RegisterInterface()
1698 mDNSInterfaceID InterfaceID
; // Identifies physical interface; MUST NOT be 0, -1, or -2
1699 mDNSAddr ip
; // The IPv4 or IPv6 address to advertise
1701 char ifname
[64]; // Windows uses a GUID string for the interface name, which doesn't fit in 16 bytes
1702 mDNSBool Advertise
; // False if you are only searching on this interface
1703 mDNSBool McastTxRx
; // Send/Receive multicast on this { InterfaceID, address family } ?
1706 typedef struct ExtraResourceRecord_struct ExtraResourceRecord
;
1707 struct ExtraResourceRecord_struct
1709 ExtraResourceRecord
*next
;
1710 mDNSu32 ClientID
; // Opaque ID field to be used by client to map an AddRecord call to a set of Extra records
1712 // Note: Add any additional fields *before* the AuthRecord in this structure, not at the end.
1713 // In some cases clients can allocate larger chunks of memory and set r->rdata->MaxRDLength to indicate
1714 // that this extra memory is available, which would result in any fields after the AuthRecord getting smashed
1717 // Note: Within an mDNSServiceCallback mDNS all API calls are legal except mDNS_Init(), mDNS_Close(), mDNS_Execute()
1718 typedef struct ServiceRecordSet_struct ServiceRecordSet
;
1719 typedef void mDNSServiceCallback(mDNS
*const m
, ServiceRecordSet
*const sr
, mStatus result
);
1720 struct ServiceRecordSet_struct
1722 // Internal state fields. These are used internally by mDNSCore; the client layer needn't be concerned with them.
1723 // No fields need to be set up by the client prior to calling mDNS_RegisterService();
1724 // all required data is passed as parameters to that function.
1725 ServiceRecordSet
*next
;
1726 uDNS_RegInfo uDNS_info
;
1727 mDNSServiceCallback
*ServiceCallback
;
1728 void *ServiceContext
;
1729 ExtraResourceRecord
*Extras
; // Optional list of extra AuthRecords attached to this service registration
1730 mDNSu32 NumSubTypes
;
1731 AuthRecord
*SubTypes
;
1732 mDNSBool Conflict
; // Set if this record set was forcibly deregistered because of a conflict
1733 domainname Host
; // Set if this service record does not use the standard target host name
1734 AuthRecord RR_ADV
; // e.g. _services._dns-sd._udp.local. PTR _printer._tcp.local.
1735 AuthRecord RR_PTR
; // e.g. _printer._tcp.local. PTR Name._printer._tcp.local.
1736 AuthRecord RR_SRV
; // e.g. Name._printer._tcp.local. SRV 0 0 port target
1737 AuthRecord RR_TXT
; // e.g. Name._printer._tcp.local. TXT PrintQueueName
1738 // Don't add any fields after AuthRecord RR_TXT.
1739 // This is where the implicit extra space goes if we allocate a ServiceRecordSet containing an oversized RR_TXT record
1742 // ***************************************************************************
1744 #pragma mark - Question structures
1747 // We record the last eight instances of each duplicate query
1748 // This gives us v4/v6 on each of Ethernet/AirPort and Firewire, and two free slots "for future expansion"
1749 // If the host has more active interfaces that this it is not fatal -- duplicate question suppression will degrade gracefully.
1750 // Since we will still remember the last eight, the busiest interfaces will still get the effective duplicate question suppression.
1751 #define DupSuppressInfoSize 8
1756 mDNSInterfaceID InterfaceID
;
1757 mDNSs32 Type
; // v4 or v6?
1764 LLQ_GetZoneInfo
= 1,
1765 LLQ_InitialRequest
= 2,
1766 LLQ_SecondaryRequest
= 3,
1769 LLQ_Established
= 6,
1771 LLQ_SuspendDeferred
= 8, // suspend once we get zone info
1772 LLQ_SuspendedPoll
= 9, // suspended from polling state
1773 LLQ_NatMapWait
= 10,
1775 // Established/error states
1786 mDNSIPPort servPort
;
1787 DNSQuestion
*question
;
1788 mDNSu32 origLease
; // seconds (relative)
1789 mDNSs32 retry
; // ticks (absolute)
1790 mDNSs32 expire
; // ticks (absolute)
1793 mDNSBool deriveRemovesOnResume
;
1794 mDNSBool NATMap
; // does this LLQ use the global LLQ NAT mapping?
1798 #define kDNSOpt_LLQ 1
1799 #define kDNSOpt_Lease 2
1801 #define kLLQ_DefLease 7200 // 2 hours
1802 #define kLLQ_MAX_TRIES 3 // retry an operation 3 times max
1803 #define kLLQ_INIT_RESEND 2 // resend an un-ack'd packet after 2 seconds, then double for each additional
1804 #define kLLQ_DEF_RETRY 1800 // retry a failed operation after 30 minutes
1805 // LLQ Operation Codes
1806 #define kLLQOp_Setup 1
1807 #define kLLQOp_Refresh 2
1808 #define kLLQOp_Event 3
1810 #define LLQ_OPT_RDLEN ((2 * sizeof(mDNSu16)) + LLQ_OPTLEN)
1811 #define LEASE_OPT_RDLEN (2 * sizeof(mDNSu16)) + sizeof(mDNSs32)
1817 LLQErr_ServFull
= 1,
1820 LLQErr_NoSuchLLQ
= 4,
1822 LLQErr_UnknownErr
= 6
1825 typedef void (*InternalResponseHndlr
)(mDNS
*const m
, DNSMessage
*msg
, const mDNSu8
*end
, DNSQuestion
*question
, void *internalContext
);
1830 InternalResponseHndlr responseCallback
; // NULL if internal field is false
1831 LLQ_Info
*llq
; // NULL for 1-shot queries
1832 mDNSBool Answered
; // have we received an answer (including NXDOMAIN) for this question?
1833 CacheRecord
*knownAnswers
;
1834 mDNSs32 RestartTime
; // Mark when we restart a suspended query
1836 } uDNS_QuestionInfo
;
1838 // Note: Within an mDNSQuestionCallback mDNS all API calls are legal except mDNS_Init(), mDNS_Close(), mDNS_Execute()
1839 typedef void mDNSQuestionCallback(mDNS
*const m
, DNSQuestion
*question
, const ResourceRecord
*const answer
, mDNSBool AddRecord
);
1840 struct DNSQuestion_struct
1842 // Internal state fields. These are used internally by mDNSCore; the client layer needn't be concerned with them.
1845 mDNSs32 DelayAnswering
; // Set if we want to defer answering this question until the cache settles
1846 mDNSs32 LastQTime
; // Last scheduled transmission of this Q on *all* applicable interfaces
1847 mDNSs32 ThisQInterval
; // LastQTime + ThisQInterval is the next scheduled transmission of this Q
1848 // ThisQInterval > 0 for an active question;
1849 // ThisQInterval = 0 for a suspended question that's still in the list
1850 // ThisQInterval = -1 for a cancelled question that's been removed from the list
1851 mDNSs32 LastAnswerPktNum
; // The sequence number of the last response packet containing an answer to this Q
1852 mDNSu32 RecentAnswerPkts
; // Number of answers since the last time we sent this query
1853 mDNSu32 CurrentAnswers
; // Number of records currently in the cache that answer this question
1854 mDNSu32 LargeAnswers
; // Number of answers with rdata > 1024 bytes
1855 mDNSu32 UniqueAnswers
; // Number of answers received with kDNSClass_UniqueRRSet bit set
1856 DNSQuestion
*DuplicateOf
;
1857 DNSQuestion
*NextInDQList
;
1858 DupSuppressInfo DupSuppress
[DupSuppressInfoSize
];
1859 mDNSInterfaceID SendQNow
; // The interface this query is being sent on right now
1860 mDNSBool SendOnAll
; // Set if we're sending this question on all active interfaces
1861 mDNSu32 RequestUnicast
; // Non-zero if we want to send query with kDNSQClass_UnicastResponse bit set
1862 mDNSs32 LastQTxTime
; // Last time this Q was sent on one (but not necessarily all) interfaces
1863 uDNS_QuestionInfo uDNS_info
;
1865 // Client API fields: The client must set up these fields *before* calling mDNS_StartQuery()
1866 mDNSInterfaceID InterfaceID
; // Non-zero if you want to issue queries only on a single specific IP interface
1867 mDNSAddr Target
; // Non-zero if you want to direct queries to a specific unicast target address
1868 mDNSIPPort TargetPort
; // Must be set if Target is set
1869 mDNSOpaque16 TargetQID
; // Must be set if Target is set
1873 mDNSBool LongLived
; // Set by client for calls to mDNS_StartQuery to indicate LLQs to unicast layer.
1874 mDNSBool ExpectUnique
; // Set by client if it's expecting unique RR(s) for this question, not shared RRs
1875 mDNSBool ForceMCast
; // Set by client to force mDNS query, even for apparently uDNS names
1876 mDNSQuestionCallback
*QuestionCallback
;
1877 void *QuestionContext
;
1882 // Client API fields: The client must set up name and InterfaceID *before* calling mDNS_StartResolveService()
1883 // When the callback is invoked, ip, port, TXTlen and TXTinfo will have been filled in with the results learned from the network.
1885 mDNSInterfaceID InterfaceID
; // ID of the interface the response was received on
1886 mDNSAddr ip
; // Remote (destination) IP address where this service can be accessed
1887 mDNSIPPort port
; // Port where this service can be accessed
1889 mDNSu8 TXTinfo
[2048]; // Additional demultiplexing information (e.g. LPR queue name)
1892 // Note: Within an mDNSServiceInfoQueryCallback mDNS all API calls are legal except mDNS_Init(), mDNS_Close(), mDNS_Execute()
1893 typedef struct ServiceInfoQuery_struct ServiceInfoQuery
;
1894 typedef void mDNSServiceInfoQueryCallback(mDNS
*const m
, ServiceInfoQuery
*query
);
1895 struct ServiceInfoQuery_struct
1897 // Internal state fields. These are used internally by mDNSCore; the client layer needn't be concerned with them.
1898 // No fields need to be set up by the client prior to calling mDNS_StartResolveService();
1899 // all required data is passed as parameters to that function.
1900 // The ServiceInfoQuery structure memory is working storage for mDNSCore to discover the requested information
1901 // and place it in the ServiceInfo structure. After the client has called mDNS_StopResolveService(), it may
1902 // dispose of the ServiceInfoQuery structure while retaining the results in the ServiceInfo structure.
1912 mDNSServiceInfoQueryCallback
*ServiceInfoQueryCallback
;
1913 void *ServiceInfoQueryContext
;
1916 // ***************************************************************************
1918 #pragma mark - NAT Traversal structures and constants
1921 #define NATMAP_INIT_RETRY (mDNSPlatformOneSecond / 4) // start at 250ms w/ exponential decay
1922 #define NATMAP_MAX_RETRY mDNSPlatformOneSecond // back off to once per second
1923 #define NATMAP_MAX_TRIES 3 // for max 3 tries
1924 #define NATMAP_DEFAULT_LEASE (60 * 60) // lease life in seconds
1925 #define NATMAP_VERS 0
1926 #define NATMAP_PORT 5351
1927 #define NATMAP_RESPONSE_MASK 0x80
1931 NATOp_AddrRequest
= 0,
1946 typedef mDNSu16 NATErr_t
;
1951 NATState_Request
= 1,
1952 NATState_Established
= 2,
1953 NATState_Legacy
= 3,
1955 NATState_Refresh
= 5,
1956 NATState_Deleted
= 6
1958 // Note: we have no explicit "cancelled" state, where a service/interface is deregistered while we
1959 // have an outstanding NAT request. This is conveyed by the "reg" pointer being set to NULL
1961 typedef packedstruct
1967 typedef packedstruct
1972 mDNSOpaque32 uptime
;
1976 typedef packedstruct
1980 mDNSOpaque16 unused
;
1984 } NATPortMapRequest
;
1986 typedef packedstruct
1991 mDNSOpaque32 uptime
;
1997 // Pass NULL for pkt on error (including timeout)
1998 typedef mDNSBool (*NATResponseHndlr
)(NATTraversalInfo
*n
, mDNS
*m
, mDNSu8
*pkt
, mDNSu16 len
);
2000 struct NATTraversalInfo_struct
2003 NATResponseHndlr ReceiveResponse
;
2004 union { AuthRecord
*RecordRegistration
; ServiceRecordSet
*ServiceRegistration
; } reg
;
2006 mDNSIPPort PublicPort
;
2007 union { NATAddrRequest AddrReq
; NATPortMapRequest PortReq
; } request
;
2008 mDNSs32 retry
; // absolute time when we retry
2009 mDNSs32 RetryInterval
; // delta between time sent and retry
2012 NATTraversalInfo
*next
;
2015 // ***************************************************************************
2017 #pragma mark - Main mDNS object, used to hold all the mDNS state
2020 typedef void mDNSCallback(mDNS
*const m
, mStatus result
);
2022 #define CACHE_HASH_SLOTS 499
2026 mDNS_KnownBug_PhantomInterfaces
= 1
2032 DNSQuestion
*ActiveQueries
; //!!!KRS this should be a hashtable (hash on messageID)
2033 DNSQuestion
*CurrentQuery
; // pointer to ActiveQueries list being examined in a loop. Functions that remove
2034 // elements from the ActiveQueries list must update this pointer (if non-NULL) as necessary.
2035 //!!!KRS do the same for registration lists
2036 ServiceRecordSet
*ServiceRegistrations
;
2037 AuthRecord
*RecordRegistrations
;
2038 NATTraversalInfo
*NATTraversals
;
2039 mDNSu16 NextMessageID
;
2040 DNSServer
*Servers
; // list of DNS servers
2042 mDNSAddr AdvertisedV4
; // IPv4 address pointed to by hostname
2043 mDNSAddr MappedV4
; // Cache of public address if PrimaryIP is behind a NAT
2044 mDNSAddr AdvertisedV6
; // IPv6 address pointed to by hostname
2045 NATTraversalInfo
*LLQNatInfo
; // Nat port mapping to receive LLQ events
2046 domainname ServiceRegDomain
; // (going away w/ multi-user support)
2047 struct uDNS_AuthInfo
*AuthInfoList
; // list of domains requiring authentication for updates.
2048 uDNS_HostnameInfo
*Hostnames
; // List of registered hostnames + hostname metadata
2049 DNSQuestion ReverseMap
; // Reverse-map query to find static hostname for service target
2050 mDNSBool ReverseMapActive
; // Is above query active?
2051 domainname StaticHostname
; // Current answer to reverse-map query (above)
2052 mDNSBool DelaySRVUpdate
; // Delay SRV target/port update to avoid "flap"
2053 mDNSs32 NextSRVUpdate
; // Time to perform delayed update
2058 // Internal state fields. These hold the main internal state of mDNSCore;
2059 // the client layer needn't be concerned with them.
2060 // No fields need to be set up by the client prior to calling mDNS_Init();
2061 // all required data is passed as parameters to that function.
2063 mDNS_PlatformSupport
*p
; // Pointer to platform-specific data of indeterminite size
2065 mDNSBool CanReceiveUnicastOn5353
;
2066 mDNSBool AdvertiseLocalAddresses
;
2067 mStatus mDNSPlatformStatus
;
2068 mDNSIPPort UnicastPort4
;
2069 mDNSIPPort UnicastPort6
;
2070 mDNSCallback
*MainCallback
;
2073 // For debugging: To catch and report locking failures
2074 mDNSu32 mDNS_busy
; // Incremented between mDNS_Lock/mDNS_Unlock section
2075 mDNSu32 mDNS_reentrancy
; // Incremented when calling a client callback
2076 mDNSu8 mDNS_shutdown
; // Set when we're shutting down, allows us to skip some unnecessary steps
2077 mDNSu8 lock_rrcache
; // For debugging: Set at times when these lists may not be modified
2078 mDNSu8 lock_Questions
;
2079 mDNSu8 lock_Records
;
2080 char MsgBuffer
[80]; // Temp storage used while building error log messages
2082 // Task Scheduling variables
2083 mDNSs32 timenow_adjust
; // Correction applied if we ever discover time went backwards
2084 mDNSs32 timenow
; // The time that this particular activation of the mDNS code started
2085 mDNSs32 timenow_last
; // The time the last time we ran
2086 mDNSs32 NextScheduledEvent
; // Derived from values below
2087 mDNSs32 SuppressSending
; // Don't send *any* packets during this time
2088 mDNSs32 NextCacheCheck
; // Next time to refresh cache record before it expires
2089 mDNSs32 NextScheduledQuery
; // Next time to send query in its exponential backoff sequence
2090 mDNSs32 NextScheduledProbe
; // Next time to probe for new authoritative record
2091 mDNSs32 NextScheduledResponse
; // Next time to send authoritative record(s) in responses
2092 mDNSs32 ExpectUnicastResponse
; // Set when we send a query with the kDNSQClass_UnicastResponse bit set
2093 mDNSs32 RandomQueryDelay
; // For de-synchronization of query packets on the wire
2094 mDNSs32 PktNum
; // Unique sequence number assigned to each received packet
2095 mDNSBool SendDeregistrations
; // Set if we need to send deregistrations (immediately)
2096 mDNSBool SendImmediateAnswers
; // Set if we need to send answers (immediately -- or as soon as SuppressSending clears)
2097 mDNSBool SleepState
; // Set if we're sleeping (send no more packets)
2099 // These fields only required for mDNS Searcher...
2100 DNSQuestion
*Questions
; // List of all registered questions, active and inactive
2101 DNSQuestion
*NewQuestions
; // Fresh questions not yet answered from cache
2102 DNSQuestion
*CurrentQuestion
; // Next question about to be examined in AnswerLocalQuestions()
2103 DNSQuestion
*LocalOnlyQuestions
; // Questions with InterfaceID set to mDNSInterface_LocalOnly
2104 DNSQuestion
*NewLocalOnlyQuestions
; // Fresh local-only questions not yet answered
2105 mDNSu32 rrcache_size
; // Total number of available cache entries
2106 mDNSu32 rrcache_totalused
; // Number of cache entries currently occupied
2107 mDNSu32 rrcache_active
; // Number of cache entries currently occupied by records that answer active questions
2108 mDNSu32 rrcache_report
;
2109 CacheEntity
*rrcache_free
;
2110 CacheGroup
*rrcache_hash
[CACHE_HASH_SLOTS
];
2112 // Fields below only required for mDNS Responder...
2113 domainlabel nicelabel
; // Rich text label encoded using canonically precomposed UTF-8
2114 domainlabel hostlabel
; // Conforms to RFC 1034 "letter-digit-hyphen" ARPANET host name rules
2115 domainname MulticastHostname
; // Fully Qualified "dot-local" Host Name, e.g. "Foo.local."
2116 UTF8str255 HIHardware
;
2117 UTF8str255 HISoftware
;
2118 AuthRecord
*ResourceRecords
;
2119 AuthRecord
*DuplicateRecords
; // Records currently 'on hold' because they are duplicates of existing records
2120 AuthRecord
*NewLocalRecords
; // Fresh local-only records not yet delivered to local-only questions
2121 AuthRecord
*CurrentRecord
; // Next AuthRecord about to be examined
2122 NetworkInterfaceInfo
*HostInterfaces
;
2123 mDNSs32 ProbeFailTime
;
2124 mDNSu32 NumFailedProbes
;
2125 mDNSs32 SuppressProbes
;
2127 // unicast-specific data
2128 uDNS_GlobalInfo uDNS_info
;
2129 mDNSs32 SuppressStdPort53Queries
; // Wait before allowing the next standard unicast query to the user's configured DNS server
2131 // Fixed storage, to avoid creating large objects on the stack
2132 DNSMessage imsg
; // Incoming message received from wire
2133 DNSMessage omsg
; // Outgoing message we're building
2134 LargeCacheRecord rec
; // Resource Record extracted from received message
2137 #define FORALL_CACHERECORDS(SLOT,CG,CR) \
2138 for ((SLOT) = 0; (SLOT) < CACHE_HASH_SLOTS; (SLOT)++) \
2139 for((CG)=m->rrcache_hash[(SLOT)]; (CG); (CG)=(CG)->next) \
2140 for ((CR) = (CG)->members; (CR); (CR)=(CR)->next)
2142 // ***************************************************************************
2144 #pragma mark - Useful Static Constants
2147 extern const mDNSIPPort zeroIPPort
;
2148 extern const mDNSv4Addr zerov4Addr
;
2149 extern const mDNSv6Addr zerov6Addr
;
2150 extern const mDNSEthAddr zeroEthAddr
;
2151 extern const mDNSv4Addr onesIPv4Addr
;
2152 extern const mDNSv6Addr onesIPv6Addr
;
2153 extern const mDNSAddr zeroAddr
;
2155 extern const mDNSInterfaceID mDNSInterface_Any
; // Zero
2156 extern const mDNSInterfaceID mDNSInterface_LocalOnly
; // Special value
2158 extern const mDNSIPPort UnicastDNSPort
;
2159 extern const mDNSIPPort MulticastDNSPort
;
2160 extern const mDNSv4Addr AllDNSAdminGroup
;
2161 extern const mDNSv4Addr AllDNSLinkGroupv4
;
2162 extern const mDNSv6Addr AllDNSLinkGroupv6
;
2163 extern const mDNSAddr AllDNSLinkGroup_v4
;
2164 extern const mDNSAddr AllDNSLinkGroup_v6
;
2166 extern const mDNSOpaque16 zeroID
;
2167 extern const mDNSOpaque16 QueryFlags
;
2168 extern const mDNSOpaque16 uQueryFlags
;
2169 extern const mDNSOpaque16 ResponseFlags
;
2170 extern const mDNSOpaque16 UpdateReqFlags
;
2171 extern const mDNSOpaque16 UpdateRespFlags
;
2173 #define localdomain (*(const domainname *)"\x5local")
2174 #define LocalReverseMapomain (*(const domainname *)"\x3" "254" "\x3" "169" "\x7" "in-addr" "\x4" "arpa")
2176 // ***************************************************************************
2178 #pragma mark - Inline functions
2181 #if (defined(_MSC_VER))
2182 #define mDNSinline static __inline
2183 #elif ((__GNUC__ > 2) || ((__GNUC__ == 2) && (__GNUC_MINOR__ >= 9)))
2184 #define mDNSinline static inline
2187 // If we're not doing inline functions, then this header needs to have the extern declarations
2188 #if !defined(mDNSinline)
2189 extern mDNSs32
NonZeroTime(mDNSs32 t
);
2190 extern mDNSu16
mDNSVal16(mDNSOpaque16 x
);
2191 extern mDNSu32
mDNSVal32(mDNSOpaque32 x
);
2192 extern mDNSOpaque16
mDNSOpaque16fromIntVal(mDNSu16 v
);
2193 extern mDNSOpaque32
mDNSOpaque32fromIntVal(mDNSu32 v
);
2196 // If we're compiling the particular C file that instantiates our inlines, then we
2197 // define "mDNSinline" (to empty string) so that we generate code in the following section
2198 #if (!defined(mDNSinline) && mDNS_InstantiateInlines)
2204 mDNSinline mDNSs32
NonZeroTime(mDNSs32 t
) { if (t
) return(t
); else return(1); }
2206 mDNSinline mDNSu16
mDNSVal16(mDNSOpaque16 x
) { return((mDNSu16
)((mDNSu16
)x
.b
[0] << 8 | (mDNSu16
)x
.b
[1])); }
2207 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])); }
2209 mDNSinline mDNSOpaque16
mDNSOpaque16fromIntVal(mDNSu16 v
)
2212 x
.b
[0] = (mDNSu8
)(v
>> 8);
2213 x
.b
[1] = (mDNSu8
)(v
& 0xFF);
2217 mDNSinline mDNSOpaque32
mDNSOpaque32fromIntVal(mDNSu32 v
)
2220 x
.b
[0] = (mDNSu8
) (v
>> 24) ;
2221 x
.b
[1] = (mDNSu8
)((v
>> 16) & 0xFF);
2222 x
.b
[2] = (mDNSu8
)((v
>> 8 ) & 0xFF);
2223 x
.b
[3] = (mDNSu8
)((v
) & 0xFF);
2229 // ***************************************************************************
2231 #pragma mark - Main Client Functions
2234 // Every client should call mDNS_Init, passing in storage for the mDNS object and the mDNS_PlatformSupport object.
2236 // Clients that are only advertising services should use mDNS_Init_NoCache and mDNS_Init_ZeroCacheSize.
2237 // Clients that plan to perform queries (mDNS_StartQuery, mDNS_StartBrowse, mDNS_StartResolveService, etc.)
2238 // need to provide storage for the resource record cache, or the query calls will return 'mStatus_NoCache'.
2239 // The rrcachestorage parameter is the address of memory for the resource record cache, and
2240 // the rrcachesize parameter is the number of entries in the CacheRecord array passed in.
2241 // (i.e. the size of the cache memory needs to be sizeof(CacheRecord) * rrcachesize).
2242 // OS X 10.3 Panther uses an initial cache size of 64 entries, and then mDNSCore sends an
2243 // mStatus_GrowCache message if it needs more.
2245 // Most clients should use mDNS_Init_AdvertiseLocalAddresses. This causes mDNSCore to automatically
2246 // create the correct address records for all the hosts interfaces. If you plan to advertise
2247 // services being offered by the local machine, this is almost always what you want.
2248 // There are two cases where you might use mDNS_Init_DontAdvertiseLocalAddresses:
2249 // 1. A client-only device, that browses for services but doesn't advertise any of its own.
2250 // 2. A proxy-registration service, that advertises services being offered by other machines, and takes
2251 // the appropriate steps to manually create the correct address records for those other machines.
2252 // In principle, a proxy-like registration service could manually create address records for its own machine too,
2253 // but this would be pointless extra effort when using mDNS_Init_AdvertiseLocalAddresses does that for you.
2255 // When mDNS has finished setting up the client's callback is called
2256 // A client can also spin and poll the mDNSPlatformStatus field to see when it changes from mStatus_Waiting to mStatus_NoError
2258 // Call mDNS_Close to tidy up before exiting
2260 // Call mDNS_Register with a completed AuthRecord object to register a resource record
2261 // If the resource record type is kDNSRecordTypeUnique (or kDNSknownunique) then if a conflicting resource record is discovered,
2262 // the resource record's mDNSRecordCallback will be called with error code mStatus_NameConflict. The callback should deregister
2263 // the record, and may then try registering the record again after picking a new name (e.g. by automatically appending a number).
2264 // Following deregistration, the RecordCallback will be called with result mStatus_MemFree to signal that it is safe to deallocate
2265 // the record's storage (memory must be freed asynchronously to allow for goodbye packets and dynamic update deregistration).
2267 // Call mDNS_StartQuery to initiate a query. mDNS will proceed to issue Multicast DNS query packets, and any time a response
2268 // is received containing a record which matches the question, the DNSQuestion's mDNSAnswerCallback function will be called
2269 // Call mDNS_StopQuery when no more answers are required
2271 // Care should be taken on multi-threaded or interrupt-driven environments.
2272 // The main mDNS routines call mDNSPlatformLock() on entry and mDNSPlatformUnlock() on exit;
2273 // each platform layer needs to implement these appropriately for its respective platform.
2274 // For example, if the support code on a particular platform implements timer callbacks at interrupt time, then
2275 // mDNSPlatformLock/Unlock need to disable interrupts or do similar concurrency control to ensure that the mDNS
2276 // code is not entered by an interrupt-time timer callback while in the middle of processing a client call.
2278 extern mStatus
mDNS_Init (mDNS
*const m
, mDNS_PlatformSupport
*const p
,
2279 CacheEntity
*rrcachestorage
, mDNSu32 rrcachesize
,
2280 mDNSBool AdvertiseLocalAddresses
,
2281 mDNSCallback
*Callback
, void *Context
);
2282 // See notes above on use of NoCache/ZeroCacheSize
2283 #define mDNS_Init_NoCache mDNSNULL
2284 #define mDNS_Init_ZeroCacheSize 0
2285 // See notes above on use of Advertise/DontAdvertiseLocalAddresses
2286 #define mDNS_Init_AdvertiseLocalAddresses mDNStrue
2287 #define mDNS_Init_DontAdvertiseLocalAddresses mDNSfalse
2288 #define mDNS_Init_NoInitCallback mDNSNULL
2289 #define mDNS_Init_NoInitCallbackContext mDNSNULL
2291 extern void mDNS_GrowCache (mDNS
*const m
, CacheEntity
*storage
, mDNSu32 numrecords
);
2292 extern void mDNS_Close (mDNS
*const m
);
2293 extern mDNSs32
mDNS_Execute (mDNS
*const m
);
2295 extern mStatus
mDNS_Register (mDNS
*const m
, AuthRecord
*const rr
);
2296 extern mStatus
mDNS_Update (mDNS
*const m
, AuthRecord
*const rr
, mDNSu32 newttl
,
2297 const mDNSu16 newrdlength
, RData
*const newrdata
, mDNSRecordUpdateCallback
*Callback
);
2298 extern mStatus
mDNS_Deregister(mDNS
*const m
, AuthRecord
*const rr
);
2300 extern mStatus
mDNS_StartQuery(mDNS
*const m
, DNSQuestion
*const question
);
2301 extern mStatus
mDNS_StopQuery (mDNS
*const m
, DNSQuestion
*const question
);
2302 extern mStatus
mDNS_Reconfirm (mDNS
*const m
, CacheRecord
*const cacherr
);
2303 extern mStatus
mDNS_ReconfirmByValue(mDNS
*const m
, ResourceRecord
*const rr
);
2304 extern mDNSs32
mDNS_TimeNow(const mDNS
*const m
);
2306 // ***************************************************************************
2308 #pragma mark - Platform support functions that are accessible to the client layer too
2311 extern mDNSs32 mDNSPlatformOneSecond
;
2313 // ***************************************************************************
2315 #pragma mark - General utility and helper functions
2318 // mDNS_RegisterService is a single call to register the set of resource records associated with a given named service.
2320 // mDNS_StartResolveService is single call which is equivalent to multiple calls to mDNS_StartQuery,
2321 // to find the IP address, port number, and demultiplexing information for a given named service.
2322 // As with mDNS_StartQuery, it executes asynchronously, and calls the ServiceInfoQueryCallback when the answer is
2323 // found. After the service is resolved, the client should call mDNS_StopResolveService to complete the transaction.
2324 // The client can also call mDNS_StopResolveService at any time to abort the transaction.
2326 // mDNS_AddRecordToService adds an additional record to a Service Record Set. This record may be deregistered
2327 // via mDNS_RemoveRecordFromService, or by deregistering the service. mDNS_RemoveRecordFromService is passed a
2328 // callback to free the memory associated with the extra RR when it is safe to do so. The ExtraResourceRecord
2329 // object can be found in the record's context pointer.
2331 // mDNS_GetBrowseDomains is a special case of the mDNS_StartQuery call, where the resulting answers
2332 // are a list of PTR records indicating (in the rdata) domains that are recommended for browsing.
2333 // After getting the list of domains to browse, call mDNS_StopQuery to end the search.
2334 // mDNS_GetDefaultBrowseDomain returns the name of the domain that should be highlighted by default.
2336 // mDNS_GetRegistrationDomains and mDNS_GetDefaultRegistrationDomain are the equivalent calls to get the list
2337 // of one or more domains that should be offered to the user as choices for where they may register their service,
2338 // and the default domain in which to register in the case where the user has made no selection.
2340 extern void mDNS_SetupResourceRecord(AuthRecord
*rr
, RData
*RDataStorage
, mDNSInterfaceID InterfaceID
,
2341 mDNSu16 rrtype
, mDNSu32 ttl
, mDNSu8 RecordType
, mDNSRecordCallback Callback
, void *Context
);
2343 extern mStatus
mDNS_RegisterService (mDNS
*const m
, ServiceRecordSet
*sr
,
2344 const domainlabel
*const name
, const domainname
*const type
, const domainname
*const domain
,
2345 const domainname
*const host
, mDNSIPPort port
, const mDNSu8 txtinfo
[], mDNSu16 txtlen
,
2346 AuthRecord
*SubTypes
, mDNSu32 NumSubTypes
,
2347 const mDNSInterfaceID InterfaceID
, mDNSServiceCallback Callback
, void *Context
);
2348 extern mStatus
mDNS_AddRecordToService(mDNS
*const m
, ServiceRecordSet
*sr
, ExtraResourceRecord
*extra
, RData
*rdata
, mDNSu32 ttl
);
2349 extern mStatus
mDNS_RemoveRecordFromService(mDNS
*const m
, ServiceRecordSet
*sr
, ExtraResourceRecord
*extra
, mDNSRecordCallback MemFreeCallback
, void *Context
);
2350 extern mStatus
mDNS_RenameAndReregisterService(mDNS
*const m
, ServiceRecordSet
*const sr
, const domainlabel
*newname
);
2351 extern mStatus
mDNS_DeregisterService(mDNS
*const m
, ServiceRecordSet
*sr
);
2353 extern mStatus
mDNS_RegisterNoSuchService(mDNS
*const m
, AuthRecord
*const rr
,
2354 const domainlabel
*const name
, const domainname
*const type
, const domainname
*const domain
,
2355 const domainname
*const host
,
2356 const mDNSInterfaceID InterfaceID
, mDNSRecordCallback Callback
, void *Context
);
2357 #define mDNS_DeregisterNoSuchService mDNS_Deregister
2359 extern mStatus
mDNS_StartBrowse(mDNS
*const m
, DNSQuestion
*const question
,
2360 const domainname
*const srv
, const domainname
*const domain
,
2361 const mDNSInterfaceID InterfaceID
, mDNSBool ForceMCast
, mDNSQuestionCallback
*Callback
, void *Context
);
2362 #define mDNS_StopBrowse mDNS_StopQuery
2364 extern mStatus
mDNS_StartResolveService(mDNS
*const m
, ServiceInfoQuery
*query
, ServiceInfo
*info
, mDNSServiceInfoQueryCallback
*Callback
, void *Context
);
2365 extern void mDNS_StopResolveService (mDNS
*const m
, ServiceInfoQuery
*query
);
2369 mDNS_DomainTypeBrowse
= 0,
2370 mDNS_DomainTypeBrowseDefault
= 1,
2371 mDNS_DomainTypeBrowseLegacy
= 2,
2372 mDNS_DomainTypeRegistration
= 3,
2373 mDNS_DomainTypeRegistrationDefault
= 4,
2375 mDNS_DomainTypeMax
= 4
2378 extern const char *const mDNS_DomainTypeNames
[];
2380 extern mStatus
mDNS_GetDomains(mDNS
*const m
, DNSQuestion
*const question
, mDNS_DomainType DomainType
, const domainname
*dom
,
2381 const mDNSInterfaceID InterfaceID
, mDNSQuestionCallback
*Callback
, void *Context
);
2382 #define mDNS_StopGetDomains mDNS_StopQuery
2383 extern mStatus
mDNS_AdvertiseDomains(mDNS
*const m
, AuthRecord
*rr
, mDNS_DomainType DomainType
, const mDNSInterfaceID InterfaceID
, char *domname
);
2384 #define mDNS_StopAdvertiseDomains mDNS_Deregister
2386 // ***************************************************************************
2388 #pragma mark - DNS name utility functions
2391 // In order to expose the full capabilities of the DNS protocol (which allows any arbitrary eight-bit values
2392 // in domain name labels, including unlikely characters like ascii nulls and even dots) all the mDNS APIs
2393 // work with DNS's native length-prefixed strings. For convenience in C, the following utility functions
2394 // are provided for converting between C's null-terminated strings and DNS's length-prefixed strings.
2397 // A simple C structure assignment of a domainname can cause a protection fault by accessing unmapped memory,
2398 // because that object is defined to be 256 bytes long, but not all domainname objects are truly the full size.
2399 // This macro uses mDNSPlatformMemCopy() to make sure it only touches the actual bytes that are valid.
2400 #define AssignDomainName(DST, SRC) mDNSPlatformMemCopy((SRC)->c, (DST)->c, DomainNameLength((SRC)))
2402 // Comparison functions
2403 extern mDNSBool
SameDomainLabel(const mDNSu8
*a
, const mDNSu8
*b
);
2404 extern mDNSBool
SameDomainName(const domainname
*const d1
, const domainname
*const d2
);
2405 extern mDNSBool
IsLocalDomain(const domainname
*d
); // returns true for domains that by default should be looked up using link-local multicast
2407 // Get total length of domain name, in native DNS format, including terminal root label
2408 // (e.g. length of "com." is 5 (length byte, three data bytes, final zero)
2409 extern mDNSu16
DomainNameLength(const domainname
*const name
);
2411 // Append functions to append one or more labels to an existing native format domain name:
2412 // AppendLiteralLabelString adds a single label from a literal C string, with no escape character interpretation.
2413 // AppendDNSNameString adds zero or more labels from a C string using conventional DNS dots-and-escaping interpretation
2414 // AppendDomainLabel adds a single label from a native format domainlabel
2415 // AppendDomainName adds zero or more labels from a native format domainname
2416 extern mDNSu8
*AppendLiteralLabelString(domainname
*const name
, const char *cstr
);
2417 extern mDNSu8
*AppendDNSNameString (domainname
*const name
, const char *cstr
);
2418 extern mDNSu8
*AppendDomainLabel (domainname
*const name
, const domainlabel
*const label
);
2419 extern mDNSu8
*AppendDomainName (domainname
*const name
, const domainname
*const append
);
2421 // Convert from null-terminated string to native DNS format:
2422 // The DomainLabel form makes a single label from a literal C string, with no escape character interpretation.
2423 // The DomainName form makes native format domain name from a C string using conventional DNS interpretation:
2424 // dots separate labels, and within each label, '\.' represents a literal dot, '\\' represents a literal
2425 // backslash and backslash with three decimal digits (e.g. \000) represents an arbitrary byte value.
2426 extern mDNSBool
MakeDomainLabelFromLiteralString(domainlabel
*const label
, const char *cstr
);
2427 extern mDNSu8
*MakeDomainNameFromDNSNameString (domainname
*const name
, const char *cstr
);
2429 // Convert native format domainlabel or domainname back to C string format
2431 // When using ConvertDomainLabelToCString, the target buffer must be MAX_ESCAPED_DOMAIN_LABEL (254) bytes long
2432 // to guarantee there will be no buffer overrun. It is only safe to use a buffer shorter than this in rare cases
2433 // where the label is known to be constrained somehow (for example, if the label is known to be either "_tcp" or "_udp").
2434 // Similarly, when using ConvertDomainNameToCString, the target buffer must be MAX_ESCAPED_DOMAIN_NAME (1005) bytes long.
2435 // See definitions of MAX_ESCAPED_DOMAIN_LABEL and MAX_ESCAPED_DOMAIN_NAME for more detailed explanation.
2436 extern char *ConvertDomainLabelToCString_withescape(const domainlabel
*const name
, char *cstr
, char esc
);
2437 #define ConvertDomainLabelToCString_unescaped(D,C) ConvertDomainLabelToCString_withescape((D), (C), 0)
2438 #define ConvertDomainLabelToCString(D,C) ConvertDomainLabelToCString_withescape((D), (C), '\\')
2439 extern char *ConvertDomainNameToCString_withescape(const domainname
*const name
, char *cstr
, char esc
);
2440 #define ConvertDomainNameToCString_unescaped(D,C) ConvertDomainNameToCString_withescape((D), (C), 0)
2441 #define ConvertDomainNameToCString(D,C) ConvertDomainNameToCString_withescape((D), (C), '\\')
2443 extern void ConvertUTF8PstringToRFC1034HostLabel(const mDNSu8 UTF8Name
[], domainlabel
*const hostlabel
);
2445 extern mDNSu8
*ConstructServiceName(domainname
*const fqdn
, const domainlabel
*name
, const domainname
*type
, const domainname
*const domain
);
2446 extern mDNSBool
DeconstructServiceName(const domainname
*const fqdn
, domainlabel
*const name
, domainname
*const type
, domainname
*const domain
);
2448 // Note: Some old functions have been replaced by more sensibly-named versions.
2449 // You can uncomment the hash-defines below if you don't want to have to change your source code right away.
2450 // When updating your code, note that (unlike the old versions) *all* the new routines take the target object
2451 // as their first parameter.
2452 //#define ConvertCStringToDomainName(SRC,DST) MakeDomainNameFromDNSNameString((DST),(SRC))
2453 //#define ConvertCStringToDomainLabel(SRC,DST) MakeDomainLabelFromLiteralString((DST),(SRC))
2454 //#define AppendStringLabelToName(DST,SRC) AppendLiteralLabelString((DST),(SRC))
2455 //#define AppendStringNameToName(DST,SRC) AppendDNSNameString((DST),(SRC))
2456 //#define AppendDomainLabelToName(DST,SRC) AppendDomainLabel((DST),(SRC))
2457 //#define AppendDomainNameToName(DST,SRC) AppendDomainName((DST),(SRC))
2459 // ***************************************************************************
2461 #pragma mark - Other utility functions and macros
2464 // mDNS_vsnprintf/snprintf return the number of characters written, excluding the final terminating null.
2465 // The output is always null-terminated: for example, if the output turns out to be exactly buflen long,
2466 // then the output will be truncated by one character to allow space for the terminating null.
2467 // Unlike standard C vsnprintf/snprintf, they return the number of characters *actually* written,
2468 // not the number of characters that *would* have been printed were buflen unlimited.
2469 extern mDNSu32
mDNS_vsnprintf(char *sbuffer
, mDNSu32 buflen
, const char *fmt
, va_list arg
);
2470 extern mDNSu32
mDNS_snprintf(char *sbuffer
, mDNSu32 buflen
, const char *fmt
, ...) IS_A_PRINTF_STYLE_FUNCTION(3,4);
2471 extern mDNSu32
NumCacheRecordsForInterfaceID(const mDNS
*const m
, mDNSInterfaceID id
);
2472 extern char *DNSTypeName(mDNSu16 rrtype
);
2473 extern char *GetRRDisplayString_rdb(const ResourceRecord
*rr
, RDataBody
*rd
, char *buffer
);
2474 #define RRDisplayString(m, rr) GetRRDisplayString_rdb(rr, &(rr)->rdata->u, (m)->MsgBuffer)
2475 #define ARDisplayString(m, rr) GetRRDisplayString_rdb(&(rr)->resrec, &(rr)->resrec.rdata->u, (m)->MsgBuffer)
2476 #define CRDisplayString(m, rr) GetRRDisplayString_rdb(&(rr)->resrec, &(rr)->resrec.rdata->u, (m)->MsgBuffer)
2477 extern mDNSBool
mDNSSameAddress(const mDNSAddr
*ip1
, const mDNSAddr
*ip2
);
2478 extern void IncrementLabelSuffix(domainlabel
*name
, mDNSBool RichText
);
2479 extern mDNSBool
IsPrivateV4Addr(mDNSAddr
*addr
); // returns true for RFC1918 private addresses
2481 #define mDNSSameIPv4Address(A,B) ((A).NotAnInteger == (B).NotAnInteger)
2482 #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])
2483 #define mDNSSameEthAddress(A,B) ((A)->w[0] == (B)->w[0] && (A)->w[1] == (B)->w[1] && (A)->w[2] == (B)->w[2])
2485 #define mDNSIPv4AddressIsZero(A) mDNSSameIPv4Address((A), zerov4Addr)
2486 #define mDNSIPv6AddressIsZero(A) mDNSSameIPv6Address((A), zerov6Addr)
2488 #define mDNSIPv4AddressIsOnes(A) mDNSSameIPv4Address((A), onesIPv4Addr)
2489 #define mDNSIPv6AddressIsOnes(A) mDNSSameIPv6Address((A), onesIPv6Addr)
2491 #define mDNSAddressIsAllDNSLinkGroup(X) ( \
2492 ((X)->type == mDNSAddrType_IPv4 && mDNSSameIPv4Address((X)->ip.v4, AllDNSLinkGroupv4)) || \
2493 ((X)->type == mDNSAddrType_IPv6 && mDNSSameIPv6Address((X)->ip.v6, AllDNSLinkGroupv6)) )
2495 #define mDNSAddressIsZero(X) ( \
2496 ((X)->type == mDNSAddrType_IPv4 && mDNSIPv4AddressIsZero((X)->ip.v4)) || \
2497 ((X)->type == mDNSAddrType_IPv6 && mDNSIPv6AddressIsZero((X)->ip.v6)) )
2499 #define mDNSAddressIsValidNonZero(X) ( \
2500 ((X)->type == mDNSAddrType_IPv4 && !mDNSIPv4AddressIsZero((X)->ip.v4)) || \
2501 ((X)->type == mDNSAddrType_IPv6 && !mDNSIPv6AddressIsZero((X)->ip.v6)) )
2503 #define mDNSAddressIsOnes(X) ( \
2504 ((X)->type == mDNSAddrType_IPv4 && mDNSIPv4AddressIsOnes((X)->ip.v4)) || \
2505 ((X)->type == mDNSAddrType_IPv6 && mDNSIPv6AddressIsOnes((X)->ip.v6)) )
2507 #define mDNSAddressIsValid(X) ( \
2508 ((X)->type == mDNSAddrType_IPv4) ? !(mDNSIPv4AddressIsZero((X)->ip.v4) || mDNSIPv4AddressIsOnes((X)->ip.v4)) : \
2509 ((X)->type == mDNSAddrType_IPv6) ? !(mDNSIPv6AddressIsZero((X)->ip.v6) || mDNSIPv6AddressIsOnes((X)->ip.v6)) : mDNSfalse)
2512 // ***************************************************************************
2514 #pragma mark - Authentication Support
2518 #define HMAC_IPAD 0x36
2519 #define HMAC_OPAD 0x5c
2522 // padded keys for inned/outer hash rounds
2525 mDNSu8 ipad
[HMAC_LEN
];
2526 mDNSu8 opad
[HMAC_LEN
];
2529 // Internal data structure to maintain authentication information for an update domain
2530 typedef struct uDNS_AuthInfo
2535 struct uDNS_AuthInfo
*next
;
2538 // Unicast DNS and Dynamic Update specific Client Calls
2540 // mDNS_SetSecretForZone tells the core to authenticate (via TSIG with an HMAC_MD5 hash of the shared secret)
2541 // when dynamically updating a given zone (and its subdomains). The key used in authentication must be in
2542 // domain name format. The shared secret must be a null-terminated base64 encoded string. A minimum size of
2543 // 16 bytes (128 bits) is recommended for an MD5 hash as per RFC 2485.
2544 // Calling this routine multiple times for a zone replaces previously entered values. Call with a NULL key
2545 // to dissable authentication for the zone.
2547 extern mStatus
mDNS_SetSecretForZone(mDNS
*m
, const domainname
*zone
, const domainname
*key
, const char *sharedSecret
);
2549 // Hostname/Unicast Interface Configuration
2551 // All hostnames advertised point to one IPv4 address and/or one IPv6 address, set via SetPrimaryInterfaceInfo. Invoking this routine
2552 // updates all existing hostnames to point to the new address.
2554 // A hostname is added via AddDynDNSHostName, which points to the primary interface's v4 and/or v6 addresss
2556 // The status callback is invoked to convey success or failure codes - the callback should not modify the AuthRecord or free memory.
2557 // Added hostnames may be removed (deregistered) via mDNS_RemoveDynDNSHostName.
2559 // Host domains added prior to specification of the primary interface address and computer name will be deferred until
2560 // these values are initialized.
2562 // When routable V4 interfaces are added or removed, mDNS_UpdateLLQs should be called to re-estabish LLQs in case the
2563 // destination address for events (i.e. the route) has changed. For performance reasons, the caller is responsible for
2564 // batching changes, e.g. calling the routine only once if multiple interfaces are simultanously removed or added.
2566 // DNS servers used to resolve unicast queries are specified by mDNS_AddDNSServer, and may later be removed via mDNS_DeleteDNSServers.
2567 // For "split" DNS configurations, in which queries for different domains are sent to different servers (e.g. VPN and external),
2568 // a domain may be associated with a DNS server. For standard configurations, specify the root label (".") or NULL.
2570 extern void mDNS_AddDynDNSHostName(mDNS
*m
, const domainname
*fqdn
, mDNSRecordCallback
*StatusCallback
, const void *StatusContext
);
2571 extern void mDNS_RemoveDynDNSHostName(mDNS
*m
, const domainname
*fqdn
);
2572 extern void mDNS_SetPrimaryInterfaceInfo(mDNS
*m
, const mDNSAddr
*v4addr
, const mDNSAddr
*v6addr
, const mDNSAddr
*router
);
2573 extern void mDNS_UpdateLLQs(mDNS
*m
);
2574 extern void mDNS_AddDNSServer(mDNS
*const m
, const mDNSAddr
*dnsAddr
, const domainname
*domain
);
2575 extern void mDNS_DeleteDNSServers(mDNS
*const m
);
2577 // Routines called by the core, exported by DNSDigest.c
2579 // Convert a base64 encoded key into a binary byte stream
2580 extern mDNSs32
DNSDigest_Base64ToBin(const char *src
, mDNSu8
*target
, mDNSu32 targsize
);
2582 // Convert an arbitrary binary key (of any length) into an HMAC key (stored in AuthInfo struct)
2583 extern void DNSDigest_ConstructHMACKey(uDNS_AuthInfo
*info
, const mDNSu8
*key
, mDNSu32 len
);
2585 // sign a DNS message. The message must be compete, with all values in network byte order. end points to the end
2586 // of the message, and is modified by this routine. numAdditionals is a pointer to the number of additional
2587 // records in HOST byte order, which is incremented upon successful completion of this routine. The function returns
2588 // the new end pointer on success, and NULL on failure.
2589 extern mDNSu8
*DNSDigest_SignMessage(DNSMessage
*msg
, mDNSu8
**end
, mDNSu16
*numAdditionals
, uDNS_AuthInfo
*info
);
2591 // ***************************************************************************
2593 #pragma mark - PlatformSupport interface
2596 // This section defines the interface to the Platform Support layer.
2597 // Normal client code should not use any of types defined here, or directly call any of the functions defined here.
2598 // The definitions are placed here because sometimes clients do use these calls indirectly, via other supported client operations.
2599 // For example, AssignDomainName is a macro defined using mDNSPlatformMemCopy()
2601 // Every platform support module must provide the following functions.
2602 // mDNSPlatformInit() typically opens a communication endpoint, and starts listening for mDNS packets.
2603 // When Setup is complete, the platform support layer calls mDNSCoreInitComplete().
2604 // mDNSPlatformSendUDP() sends one UDP packet
2605 // When a packet is received, the PlatformSupport code calls mDNSCoreReceive()
2606 // mDNSPlatformClose() tidies up on exit
2608 // Note: mDNSPlatformMemAllocate/mDNSPlatformMemFree are only required for handling oversized resource records and unicast DNS.
2609 // If your target platform has a well-defined specialized application, and you know that all the records it uses
2610 // are InlineCacheRDSize or less, then you can just make a simple mDNSPlatformMemAllocate() stub that always returns
2611 // NULL. InlineCacheRDSize is a compile-time constant, which is set by default to 64. If you need to handle records
2612 // a little larger than this and you don't want to have to implement run-time allocation and freeing, then you
2613 // can raise the value of this constant to a suitable value (at the expense of increased memory usage).
2615 // USE CAUTION WHEN CALLING mDNSPlatformRawTime: The m->timenow_adjust correction factor needs to be added
2616 // Generally speaking:
2617 // Code that's protected by the main mDNS lock should just use the m->timenow value
2618 // Code outside the main mDNS lock should use mDNS_TimeNow(m) to get properly adjusted time
2619 // In certain cases there may be reasons why it's necessary to get the time without taking the lock first
2620 // (e.g. inside the routines that are doing the locking and unlocking, where a call to get the lock would result in a
2621 // recursive loop); in these cases use mDNS_TimeNow_NoLock(m) to get mDNSPlatformRawTime with the proper correction factor added.
2623 // mDNSPlatformUTC returns the time, in seconds, since Jan 1st 1970 UTC and is required for generating TSIG records
2625 extern mStatus
mDNSPlatformInit (mDNS
*const m
);
2626 extern void mDNSPlatformClose (mDNS
*const m
);
2627 extern mStatus
mDNSPlatformSendUDP(const mDNS
*const m
, const void *const msg
, const mDNSu8
*const end
,
2628 mDNSInterfaceID InterfaceID
, const mDNSAddr
*dst
, mDNSIPPort dstport
);
2630 extern void mDNSPlatformLock (const mDNS
*const m
);
2631 extern void mDNSPlatformUnlock (const mDNS
*const m
);
2633 extern void mDNSPlatformStrCopy (const void *src
, void *dst
);
2634 extern mDNSu32
mDNSPlatformStrLen (const void *src
);
2635 extern void mDNSPlatformMemCopy (const void *src
, void *dst
, mDNSu32 len
);
2636 extern mDNSBool
mDNSPlatformMemSame (const void *src
, const void *dst
, mDNSu32 len
);
2637 extern void mDNSPlatformMemZero ( void *dst
, mDNSu32 len
);
2638 extern void * mDNSPlatformMemAllocate (mDNSu32 len
);
2639 extern void mDNSPlatformMemFree (void *mem
);
2640 extern mDNSu32
mDNSPlatformRandomSeed (void);
2641 extern mStatus
mDNSPlatformTimeInit (void);
2642 extern mDNSs32
mDNSPlatformRawTime (void);
2643 extern mDNSs32
mDNSPlatformUTC (void);
2644 #define mDNS_TimeNow_NoLock(m) (mDNSPlatformRawTime() + m->timenow_adjust)
2646 // Platform support modules should provide the following functions to map between opaque interface IDs
2647 // and interface indexes in order to support the DNS-SD API. If your target platform does not support
2648 // multiple interfaces and/or does not support the DNS-SD API, these functions can be empty.
2649 extern mDNSInterfaceID
mDNSPlatformInterfaceIDfromInterfaceIndex(const mDNS
*const m
, mDNSu32 index
);
2650 extern mDNSu32
mDNSPlatformInterfaceIndexfromInterfaceID(const mDNS
*const m
, mDNSInterfaceID id
);
2652 // Every platform support module must provide the following functions if it is to support unicast DNS
2653 // and Dynamic Update.
2654 // All TCP socket operations implemented by the platform layer MUST NOT BLOCK.
2655 // mDNSPlatformTCPConnect initiates a TCP connection with a peer, adding the socket descriptor to the
2656 // main event loop. The return value indicates whether the connection succeeded, failed, or is pending
2657 // (i.e. the call would block.) On return, the descriptor parameter is set to point to the connected socket.
2658 // The TCPConnectionCallback is subsequently invoked when the connection
2659 // completes (in which case the ConnectionEstablished parameter is true), or data is available for
2660 // reading on the socket (indicated by the ConnectionEstablished parameter being false.) If the connection
2661 // asynchronously fails, the TCPConnectionCallback should be invoked as usual, with the error being
2662 // returned in subsequent calls to PlatformReadTCP or PlatformWriteTCP. (This allows for platforms
2663 // with limited asynchronous error detection capabilities.) PlatformReadTCP and PlatformWriteTCP must
2664 // return the number of bytes read/written, 0 if the call would block, and -1 if an error.
2665 // PlatformTCPCloseConnection must close the connection to the peer and remove the descriptor from the
2666 // event loop. CloseConnectin may be called at any time, including in a ConnectionCallback.
2668 typedef void (*TCPConnectionCallback
)(int sd
, void *context
, mDNSBool ConnectionEstablished
);
2669 extern mStatus
mDNSPlatformTCPConnect(const mDNSAddr
*dst
, mDNSOpaque16 dstport
, mDNSInterfaceID InterfaceID
,
2670 TCPConnectionCallback callback
, void *context
, int *descriptor
);
2671 extern void mDNSPlatformTCPCloseConnection(int sd
);
2672 extern int mDNSPlatformReadTCP(int sd
, void *buf
, int buflen
);
2673 extern int mDNSPlatformWriteTCP(int sd
, const char *msg
, int len
);
2675 // Platforms that support unicast browsing and dynamic update registration for clients who do not specify a domain
2676 // in browse/registration calls must implement these routines to get the "default" browse/registration list.
2677 // The Get() functions must return a linked list of DNameListElem structs, allocated via mDNSPlatformMemAllocate.
2678 // Platforms may implement the Get() calls via the mDNS_CopyDNameList() helper routine.
2679 // Callers should free lists obtained via the Get() calls with th mDNS_FreeDNameList routine, provided by the core.
2681 typedef struct DNameListElem
2684 struct DNameListElem
*next
;
2687 extern DNameListElem
*mDNSPlatformGetSearchDomainList(void);
2688 extern DNameListElem
*mDNSPlatformGetRegDomainList(void);
2690 // Helper functions provided by the core
2691 extern DNameListElem
*mDNS_CopyDNameList(const DNameListElem
*orig
);
2692 extern void mDNS_FreeDNameList(DNameListElem
*list
);
2694 #ifdef _LEGACY_NAT_TRAVERSAL_
2695 // Support for legacy NAT traversal protocols, implemented by the platform layer and callable by the core.
2697 #define DYN_PORT_MIN 49152 // ephemeral port range
2698 #define DYN_PORT_MAX 65535
2699 #define LEGACY_NATMAP_MAX_TRIES 4 // if our desired mapping is taken, how many times we try mapping to a random port
2701 extern mStatus
LNT_GetPublicIP(mDNSOpaque32
*ip
);
2702 extern mStatus
LNT_MapPort(mDNSIPPort priv
, mDNSIPPort pub
, mDNSBool tcp
);
2703 extern mStatus
LNT_UnmapPort(mDNSIPPort PubPort
, mDNSBool tcp
);
2704 #endif // _LEGACY_NAT_TRAVERSAL_
2706 // The core mDNS code provides these functions, for the platform support code to call at appropriate times
2708 // mDNS_SetFQDN() is called once on startup (typically from mDNSPlatformInit())
2709 // and then again on each subsequent change of the host name.
2711 // mDNS_RegisterInterface() is used by the platform support layer to inform mDNSCore of what
2712 // physical and/or logical interfaces are available for sending and receiving packets.
2713 // Typically it is called on startup for each available interface, but register/deregister may be
2714 // called again later, on multiple occasions, to inform the core of interface configuration changes.
2715 // If set->Advertise is set non-zero, then mDNS_RegisterInterface() also registers the standard
2716 // resource records that should be associated with every publicised IP address/interface:
2717 // -- Name-to-address records (A/AAAA)
2718 // -- Address-to-name records (PTR)
2719 // -- Host information (HINFO)
2720 // IMPORTANT: The specified mDNSInterfaceID MUST NOT be 0, -1, or -2; these values have special meaning
2721 // mDNS_RegisterInterface does not result in the registration of global hostnames via dynamic update -
2722 // see mDNS_SetPrimaryInterfaceInfo, mDNS_AddDynDNSHostName, etc. for this purpose.
2723 // Note that the set may be deallocated immediately after it is deregistered via mDNS_DeegisterInterface.
2725 // mDNS_RegisterDNS() is used by the platform support layer to provide the core with the addresses of
2726 // available domain name servers for unicast queries/updates. RegisterDNS() should be called once for
2727 // each name server, typically at startup, or when a new name server becomes available. DeregiterDNS()
2728 // must be called whenever a registered name server becomes unavailable. DeregisterDNSList deregisters
2729 // all registered servers. mDNS_DNSRegistered() returns true if one or more servers are registered in the core.
2731 // mDNSCoreInitComplete() is called when the platform support layer is finished.
2732 // Typically this is at the end of mDNSPlatformInit(), but may be later
2733 // (on platforms like OT that allow asynchronous initialization of the networking stack).
2735 // mDNSCoreReceive() is called when a UDP packet is received
2737 // mDNSCoreMachineSleep() is called when the machine sleeps or wakes
2738 // (This refers to heavyweight laptop-style sleep/wake that disables network access,
2739 // not lightweight second-by-second CPU power management modes.)
2741 extern void mDNS_SetFQDN(mDNS
*const m
);
2742 extern mStatus
mDNS_RegisterInterface (mDNS
*const m
, NetworkInterfaceInfo
*set
, mDNSs32 delay
);
2743 extern void mDNS_DeregisterInterface(mDNS
*const m
, NetworkInterfaceInfo
*set
);
2744 extern void mDNSCoreInitComplete(mDNS
*const m
, mStatus result
);
2745 extern void mDNSCoreReceive(mDNS
*const m
, void *const msg
, const mDNSu8
*const end
,
2746 const mDNSAddr
*const srcaddr
, const mDNSIPPort srcport
,
2747 const mDNSAddr
*const dstaddr
, const mDNSIPPort dstport
, const mDNSInterfaceID InterfaceID
);
2748 extern void mDNSCoreMachineSleep(mDNS
*const m
, mDNSBool wake
);
2750 extern mDNSBool
mDNSAddrIsDNSMulticast(const mDNSAddr
*ip
);
2752 // ***************************************************************************
2754 #pragma mark - Compile-Time assertion checks
2757 // Some C compiler cleverness. We can make the compiler check certain things for
2758 // us, and report compile-time errors if anything is wrong. The usual way to do
2759 // this would be to use a run-time "if" statement, but then you don't find out
2760 // what's wrong until you run the software. This way, if the assertion condition
2761 // is false, the array size is negative, and the complier complains immediately.
2763 struct mDNS_CompileTimeAssertionChecks
2765 // Check that the compiler generated our on-the-wire packet format structure definitions
2766 // properly packed, without adding padding bytes to align fields on 32-bit or 64-bit boundaries.
2767 char assert0
[(sizeof(rdataSRV
) == 262 ) ? 1 : -1];
2768 char assert1
[(sizeof(DNSMessageHeader
) == 12 ) ? 1 : -1];
2769 char assert2
[(sizeof(DNSMessage
) == 12+AbsoluteMaxDNSMessageData
) ? 1 : -1];
2770 char assert3
[(sizeof(mDNSs8
) == 1 ) ? 1 : -1];
2771 char assert4
[(sizeof(mDNSu8
) == 1 ) ? 1 : -1];
2772 char assert5
[(sizeof(mDNSs16
) == 2 ) ? 1 : -1];
2773 char assert6
[(sizeof(mDNSu16
) == 2 ) ? 1 : -1];
2774 char assert7
[(sizeof(mDNSs32
) == 4 ) ? 1 : -1];
2775 char assert8
[(sizeof(mDNSu32
) == 4 ) ? 1 : -1];
2776 char assert9
[(sizeof(mDNSOpaque16
) == 2 ) ? 1 : -1];
2777 char assertA
[(sizeof(mDNSOpaque32
) == 4 ) ? 1 : -1];
2778 char assertB
[(sizeof(mDNSOpaque128
) == 16 ) ? 1 : -1];
2779 char assertC
[(sizeof(CacheRecord
) >= sizeof(CacheGroup
) ) ? 1 : -1];
2782 // ***************************************************************************
projects / apple / mdnsresponder.git / blob