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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 1.284 2005/07/29 18:04:22 ksekar
64 <rdar://problem/4137930> Hostname registration should register IPv6 AAAA record with DNS Update
66 Revision 1.283 2005/05/13 20:45:09 ksekar
67 <rdar://problem/4074400> Rapid wide-area txt record updates don't work
69 Revision 1.282 2005/03/16 00:42:32 ksekar
70 <rdar://problem/4012279> Long-lived queries not working on Windows
72 Revision 1.281 2005/02/25 17:47:44 ksekar
73 <rdar://problem/4021868> SendServiceRegistration fails on wake from sleep
75 Revision 1.280 2005/02/25 04:21:00 cheshire
76 <rdar://problem/4015377> mDNS -F returns the same domain multiple times with different casing
78 Revision 1.279 2005/02/17 01:56:14 cheshire
79 Increase ifname field to 64 bytes
81 Revision 1.278 2005/02/09 23:38:51 ksekar
82 <rdar://problem/3993508> Reregister hostname when DNS server changes but IP address does not
84 Revision 1.277 2005/02/09 23:31:12 ksekar
85 <rdar://problem/3984374> NAT-PMP response callback should return a boolean indicating if the packet matched the request
87 Revision 1.276 2005/02/01 19:33:29 ksekar
88 <rdar://problem/3985239> Keychain format too restrictive
90 Revision 1.275 2005/01/27 22:57:55 cheshire
91 Fix compile errors on gcc4
93 Revision 1.274 2005/01/19 21:01:54 ksekar
94 <rdar://problem/3955355> uDNS needs to support subtype registration and browsing
96 Revision 1.273 2005/01/19 19:15:31 ksekar
97 Refinement to <rdar://problem/3954575> - Simplify mDNS_PurgeResultsForDomain logic and move into daemon layer
99 Revision 1.272 2005/01/18 18:10:55 ksekar
100 <rdar://problem/3954575> Use 10.4 resolver API to get search domains
102 Revision 1.271 2005/01/15 00:56:41 ksekar
103 <rdar://problem/3954575> Unicast services don't disappear when logging
106 Revision 1.270 2005/01/14 18:34:22 ksekar
107 <rdar://problem/3954571> Services registered outside of firewall don't succeed after location change
109 Revision 1.269 2005/01/11 22:50:52 ksekar
110 Fixed constant naming (was using kLLQ_DefLease for update leases)
112 Revision 1.268 2004/12/22 22:25:47 ksekar
113 <rdar://problem/3734265> NATPMP: handle location changes
115 Revision 1.267 2004/12/22 00:13:49 ksekar
116 <rdar://problem/3873993> Change version, port, and polling interval for LLQ
118 Revision 1.266 2004/12/18 03:13:45 cheshire
119 <rdar://problem/3751638> kDNSServiceInterfaceIndexLocalOnly should return all local records
121 Revision 1.265 2004/12/17 23:37:45 cheshire
122 <rdar://problem/3485365> Guard against repeating wireless dissociation/re-association
123 (and other repetitive configuration changes)
125 Revision 1.264 2004/12/17 05:25:46 cheshire
126 <rdar://problem/3925163> Shorten DNS-SD queries to avoid NAT bugs
128 Revision 1.263 2004/12/16 20:40:25 cheshire
131 Revision 1.262 2004/12/16 20:13:00 cheshire
132 <rdar://problem/3324626> Cache memory management improvements
134 Revision 1.261 2004/12/14 21:21:20 ksekar
135 <rdar://problem/3825979> NAT-PMP: Update response format to contain "Seconds Since Boot"
137 Revision 1.260 2004/12/12 23:51:42 ksekar
138 <rdar://problem/3845683> Wide-area registrations should fallback to using DHCP hostname as target
140 Revision 1.259 2004/12/11 20:55:29 ksekar
141 <rdar://problem/3916479> Clean up registration state machines
143 Revision 1.258 2004/12/10 20:48:32 cheshire
144 <rdar://problem/3705229> Need to pick final EDNS numbers for LLQ and GC
146 Revision 1.257 2004/12/10 02:09:23 cheshire
147 <rdar://problem/3898376> Modify default TTLs
149 Revision 1.256 2004/12/09 03:15:40 ksekar
150 <rdar://problem/3806610> use _legacy instead of _default to find "empty string" browse domains
152 Revision 1.255 2004/12/07 22:48:37 cheshire
155 Revision 1.254 2004/12/07 21:26:04 ksekar
156 <rdar://problem/3908336> DNSServiceRegisterRecord() can crash on deregistration
158 Revision 1.253 2004/12/07 20:42:33 cheshire
159 Add explicit context parameter to mDNS_RemoveRecordFromService()
161 Revision 1.252 2004/12/07 03:02:12 ksekar
162 Fixed comments, grouped unicast-specific routines together
164 Revision 1.251 2004/12/06 21:15:22 ksekar
165 <rdar://problem/3884386> mDNSResponder crashed in CheckServiceRegistrations
167 Revision 1.250 2004/12/04 02:12:45 cheshire
168 <rdar://problem/3517236> mDNSResponder puts LargeCacheRecord on the stack
170 Revision 1.249 2004/12/03 05:18:33 ksekar
171 <rdar://problem/3810596> mDNSResponder needs to return more specific TSIG errors
173 Revision 1.248 2004/12/02 20:03:48 ksekar
174 <rdar://problem/3889647> Still publishes wide-area domains even after switching to a local subnet
176 Revision 1.247 2004/12/01 20:57:19 ksekar
177 <rdar://problem/3873921> Wide Area Service Discovery must be split-DNS aware
179 Revision 1.246 2004/11/29 23:26:32 cheshire
180 Added NonZeroTime() function, which usually returns the value given, with the exception
181 that if the value given is zero, it returns one instead. For timer values where zero is
182 used to mean "not set", this can be used to ensure that setting them to the result of an
183 interval computation (e.g. "now+interval") does not inadvertently result in a zero value.
185 Revision 1.245 2004/11/25 01:28:09 cheshire
186 <rdar://problem/3557050> Need to implement random delay for 'QU' unicast replies (and set cache flush bit too)
188 Revision 1.244 2004/11/24 22:00:59 cheshire
189 Move definition of mDNSAddressIsAllDNSLinkGroup() from mDNSMacOSX.c to mDNSEmbeddedAPI.h
191 Revision 1.243 2004/11/23 22:43:53 cheshire
192 Tidy up code alignment
194 Revision 1.242 2004/11/23 03:39:46 cheshire
195 Let interface name/index mapping capability live directly in JNISupport.c,
196 instead of having to call through to the daemon via IPC to get this information.
198 Revision 1.241 2004/11/22 17:16:19 ksekar
199 <rdar://problem/3854298> Unicast services don't disappear when you disable all networking
201 Revision 1.240 2004/11/19 02:32:43 ksekar
202 Wide-Area Security: Add LLQ-ID to events
204 Revision 1.239 2004/11/15 20:09:23 ksekar
205 <rdar://problem/3719050> Wide Area support for Add/Remove record
207 Revision 1.238 2004/11/12 03:16:48 rpantos
208 rdar://problem/3809541 Add mDNSPlatformGetInterfaceByName, mDNSPlatformGetInterfaceName
210 Revision 1.237 2004/11/10 20:40:53 ksekar
211 <rdar://problem/3868216> LLQ mobility fragile on non-primary interface
213 Revision 1.236 2004/11/01 20:36:11 ksekar
214 <rdar://problem/3802395> mDNSResponder should not receive Keychain Notifications
216 Revision 1.235 2004/11/01 17:48:14 cheshire
217 Changed SOA serial number back to signed. RFC 1035 may describe it as "unsigned", but
218 it's wrong. The SOA serial is a modular counter, as explained in "DNS & BIND", page
219 137. Since C doesn't have a modular type, we used signed, C's closest approximation.
221 Revision 1.234 2004/10/29 21:59:02 ksekar
222 SOA serial should be a unsigned integer, as per RFC 1035
224 Revision 1.233 2004/10/28 03:24:41 cheshire
225 Rename m->CanReceiveUnicastOn as m->CanReceiveUnicastOn5353
227 Revision 1.232 2004/10/26 06:20:23 cheshire
228 Add mDNSAddressIsValidNonZero() macro
230 Revision 1.231 2004/10/26 06:11:41 cheshire
231 Add improved logging to aid in diagnosis of <rdar://problem/3842714> mDNSResponder crashed
233 Revision 1.230 2004/10/26 03:52:02 cheshire
234 Update checkin comments
236 Revision 1.229 2004/10/25 19:30:52 ksekar
237 <rdar://problem/3827956> Simplify dynamic host name structures
239 Revision 1.228 2004/10/23 01:16:00 cheshire
240 <rdar://problem/3851677> uDNS operations not always reliable on multi-homed hosts
242 Revision 1.227 2004/10/22 20:52:07 ksekar
243 <rdar://problem/3799260> Create NAT port mappings for Long Lived Queries
245 Revision 1.226 2004/10/20 01:50:40 cheshire
246 <rdar://problem/3844991> Cannot resolve non-local registrations using the mach API
247 Implemented ForceMCast mode for AuthRecords as well as for Questions
249 Revision 1.225 2004/10/19 21:33:17 cheshire
250 <rdar://problem/3844991> Cannot resolve non-local registrations using the mach API
251 Added flag 'kDNSServiceFlagsForceMulticast'. Passing through an interface id for a unicast name
252 doesn't force multicast unless you set this flag to indicate explicitly that this is what you want
254 Revision 1.224 2004/10/16 00:16:59 cheshire
255 <rdar://problem/3770558> Replace IP TTL 255 check with local subnet source address check
257 Revision 1.223 2004/10/15 23:00:17 ksekar
258 <rdar://problem/3799242> Need to update LLQs on location changes
260 Revision 1.222 2004/10/12 02:49:20 ksekar
261 <rdar://problem/3831228> Clean up LLQ sleep/wake, error handling
263 Revision 1.221 2004/10/10 06:57:15 cheshire
264 Change definition of "localdomain" to make code compile a little smaller
266 Revision 1.220 2004/10/06 01:44:19 cheshire
267 <rdar://problem/3813936> Resolving too quickly sometimes returns stale TXT record
269 Revision 1.219 2004/10/03 23:18:58 cheshire
270 Move address comparison macros from DNSCommon.h to mDNSEmbeddedAPI.h
272 Revision 1.218 2004/10/03 23:14:12 cheshire
273 Add "mDNSEthAddr" type and "zeroEthAddr" constant
275 Revision 1.217 2004/09/30 00:24:56 ksekar
276 <rdar://problem/3695802> Dynamically update default registration domains on config change
278 Revision 1.216 2004/09/27 23:24:32 cheshire
279 Fix typo: SOA refresh interval is supposed to be unsigned
281 Revision 1.215 2004/09/26 23:20:35 ksekar
282 <rdar://problem/3813108> Allow default registrations in multiple wide-area domains
284 Revision 1.214 2004/09/25 02:41:39 cheshire
285 <rdar://problem/3637266> Deliver near-pending "remove" events before new "add" events
287 Revision 1.213 2004/09/25 02:24:27 cheshire
288 Removed unused rr->UseCount
290 Revision 1.212 2004/09/24 20:57:39 cheshire
291 <rdar://problem/3680902> Eliminate inappropriate casts that cause misaligned-address errors
293 Revision 1.211 2004/09/24 20:33:22 cheshire
294 Remove unused DNSDigest_MD5 declaration
296 Revision 1.210 2004/09/23 20:21:07 cheshire
297 <rdar://problem/3426876> Refine "immediate answer burst; restarting exponential backoff sequence" logic
298 Associate a unique sequence number with each received packet, and only increment the count of recent answer
299 packets if the packet sequence number for this answer record is not one we've already seen and counted.
301 Revision 1.209 2004/09/23 20:14:39 cheshire
302 Rename "question->RecentAnswers" to "question->RecentAnswerPkts"
304 Revision 1.208 2004/09/23 00:50:53 cheshire
305 <rdar://problem/3419452> Don't send a (DE) if a service is unregistered after wake from sleep
307 Revision 1.207 2004/09/22 02:34:46 cheshire
308 Move definitions of default TTL times from mDNS.c to mDNSEmbeddedAPI.h
310 Revision 1.206 2004/09/22 00:41:59 cheshire
311 Move tcp connection status codes into the legal range allocated for mDNS use
313 Revision 1.205 2004/09/21 23:40:11 ksekar
314 <rdar://problem/3810349> mDNSResponder to return errors on NAT traversal failure
316 Revision 1.204 2004/09/21 23:29:50 cheshire
317 <rdar://problem/3680045> DNSServiceResolve should delay sending packets
319 Revision 1.203 2004/09/21 20:58:22 cheshire
320 Add ifname field to NetworkInterfaceInfo_struct
322 Revision 1.202 2004/09/17 00:46:34 cheshire
323 mDNS_TimeNow should take const mDNS parameter
325 Revision 1.201 2004/09/17 00:31:51 cheshire
326 For consistency with ipv6, renamed rdata field 'ip' to 'ipv4'
328 Revision 1.200 2004/09/17 00:19:10 cheshire
329 For consistency with AllDNSLinkGroupv6, rename AllDNSLinkGroup to AllDNSLinkGroupv4
331 Revision 1.199 2004/09/16 21:59:16 cheshire
332 For consistency with zerov6Addr, rename zeroIPAddr to zerov4Addr
334 Revision 1.198 2004/09/16 21:36:36 cheshire
335 <rdar://problem/3803162> Fix unsafe use of mDNSPlatformTimeNow()
336 Changes to add necessary locking calls around unicast DNS operations
338 Revision 1.197 2004/09/16 00:24:48 cheshire
339 <rdar://problem/3803162> Fix unsafe use of mDNSPlatformTimeNow()
341 Revision 1.196 2004/09/14 23:42:35 cheshire
342 <rdar://problem/3801296> Need to seed random number generator from platform-layer data
344 Revision 1.195 2004/09/14 23:27:46 cheshire
347 Revision 1.194 2004/09/10 00:49:57 cheshire
348 <rdar://problem/3787644> Add error code kDNSServiceErr_Firewall, for future use
350 Revision 1.193 2004/09/03 19:23:05 ksekar
351 <rdar://problem/3788460>: Need retransmission mechanism for wide-area service registrations
353 Revision 1.192 2004/09/02 03:48:47 cheshire
354 <rdar://problem/3709039> Disable targeted unicast query support by default
355 1. New flag kDNSServiceFlagsAllowRemoteQuery to indicate we want to allow remote queries for this record
356 2. New field AllowRemoteQuery in AuthRecord structure
357 3. uds_daemon.c sets AllowRemoteQuery if kDNSServiceFlagsAllowRemoteQuery is set
358 4. mDNS.c only answers remote queries if AllowRemoteQuery is set
360 Revision 1.191 2004/08/25 00:37:27 ksekar
361 <rdar://problem/3774635>: Cleanup DynDNS hostname registration code
363 Revision 1.190 2004/08/18 17:35:41 ksekar
364 <rdar://problem/3651443>: Feature #9586: Need support for Legacy NAT gateways
366 Revision 1.189 2004/08/14 03:22:41 cheshire
367 <rdar://problem/3762579> Dynamic DNS UI <-> mDNSResponder glue
368 Add GetUserSpecifiedDDNSName() routine
369 Convert ServiceRegDomain to domainname instead of C string
370 Replace mDNS_GenerateFQDN/mDNS_GenerateGlobalFQDN with mDNS_SetFQDNs
372 Revision 1.188 2004/08/13 23:46:58 cheshire
373 "asyncronous" -> "asynchronous"
375 Revision 1.187 2004/08/13 23:37:02 cheshire
376 Now that we do both uDNS and mDNS, global replace "uDNS_info.hostname" with
377 "uDNS_info.UnicastHostname" for clarity
379 Revision 1.186 2004/08/13 23:25:00 cheshire
380 Now that we do both uDNS and mDNS, global replace "m->hostname" with
381 "m->MulticastHostname" for clarity
383 Revision 1.185 2004/08/12 00:32:36 ksekar
384 <rdar://problem/3759567>: LLQ Refreshes never terminate if unanswered
386 Revision 1.184 2004/08/11 17:09:31 cheshire
387 Add comment clarifying the applicability of these APIs
389 Revision 1.183 2004/08/10 23:19:14 ksekar
390 <rdar://problem/3722542>: DNS Extension daemon for Wide Area Service Discovery
391 Moved routines/constants to allow extern access for garbage collection daemon
393 Revision 1.182 2004/07/30 17:40:06 ksekar
394 <rdar://problem/3739115>: TXT Record updates not available for wide-area services
396 Revision 1.181 2004/07/29 19:27:15 ksekar
397 NATPMP Support - minor fixes and cleanup
399 Revision 1.180 2004/07/29 02:03:35 ksekar
400 Delete unused #define and structure field
402 Revision 1.179 2004/07/26 22:49:30 ksekar
403 <rdar://problem/3651409>: Feature #9516: Need support for NATPMP in client
405 Revision 1.178 2004/07/13 21:24:24 rpantos
406 Fix for <rdar://problem/3701120>.
408 Revision 1.177 2004/06/05 00:04:26 cheshire
409 <rdar://problem/3668639>: wide-area domains should be returned in reg. domain enumeration
411 Revision 1.176 2004/06/04 08:58:29 ksekar
412 <rdar://problem/3668624>: Keychain integration for secure dynamic update
414 Revision 1.175 2004/06/04 00:15:06 cheshire
415 Move misplaced brackets
417 Revision 1.174 2004/06/03 23:30:16 cheshire
418 Remove extraneous blank lines and white space
420 Revision 1.173 2004/06/03 03:09:58 ksekar
421 <rdar://problem/3668626>: Garbage Collection for Dynamic Updates
423 Revision 1.172 2004/06/01 23:46:50 ksekar
424 <rdar://problem/3675149>: DynDNS: dynamically look up LLQ/Update ports
426 Revision 1.171 2004/05/28 23:42:37 ksekar
427 <rdar://problem/3258021>: Feature: DNS server->client notification on record changes (#7805)
429 Revision 1.170 2004/05/18 23:51:25 cheshire
430 Tidy up all checkin comments to use consistent "<rdar://problem/xxxxxxx>" format for bug numbers
432 Revision 1.169 2004/05/13 04:54:20 ksekar
433 Unified list copy/free code. Added symetric list for
435 Revision 1.168 2004/05/12 22:03:09 ksekar
436 Made GetSearchDomainList a true platform-layer call (declaration moved
437 from mDNSMacOSX.h to mDNSEmbeddedAPI.h), implemented to return "local"
438 only on non-OSX platforms. Changed call to return a copy of the list
439 to avoid shared memory issues. Added a routine to free the list.
441 Revision 1.167 2004/04/22 04:07:01 cheshire
442 Fix from Bob Bradley: Don't try to do inline functions on compilers that don't support it
444 Revision 1.166 2004/04/22 03:15:56 cheshire
445 Fix use of "struct __attribute__((__packed__))" so it only applies on GCC >= 2.9
447 Revision 1.165 2004/04/22 03:05:28 cheshire
448 kDNSClass_ANY should be kDNSQClass_ANY
450 Revision 1.164 2004/04/21 02:55:03 cheshire
451 Update comments describing 'InterfaceActive' field
453 Revision 1.163 2004/04/21 02:49:11 cheshire
454 To reduce future confusion, renamed 'TxAndRx' to 'McastTxRx'
456 Revision 1.162 2004/04/15 00:51:28 bradley
457 Minor tweaks for Windows and C++ builds. Added casts for signed/unsigned integers and 64-bit pointers.
458 Prefix some functions with mDNS to avoid conflicts. Disable benign warnings on Microsoft compilers.
460 Revision 1.161 2004/04/14 23:09:28 ksekar
461 Support for TSIG signed dynamic updates.
463 Revision 1.160 2004/04/09 17:40:26 cheshire
464 Remove unnecessary "Multicast" field -- it duplicates the semantics of the existing McastTxRx field
466 Revision 1.159 2004/04/09 16:37:15 cheshire
467 Suggestion from Bob Bradley:
468 Move NumCacheRecordsForInterfaceID() to DNSCommon.c so it's available to all platform layers
470 Revision 1.158 2004/04/02 19:38:33 cheshire
471 Update comment about typical RR TTLs
473 Revision 1.157 2004/04/02 19:35:53 cheshire
474 Add clarifying comments about legal mDNSInterfaceID values
476 Revision 1.156 2004/04/02 19:19:48 cheshire
477 Add code to do optional logging of multi-packet KA list time intervals
479 Revision 1.155 2004/03/24 00:29:45 ksekar
480 Make it safe to call StopQuery in a unicast question callback
482 Revision 1.154 2004/03/20 01:05:49 cheshire
483 Test __LP64__ and __ILP64__ to compile properly on a wider range of 64-bit architectures
485 Revision 1.153 2004/03/13 01:57:33 ksekar
486 <rdar://problem/3192546>: DynDNS: Dynamic update of service records
488 Revision 1.152 2004/03/09 02:27:16 cheshire
489 Remove erroneous underscore in 'packed_struct' (makes no difference now, but might in future)
491 Revision 1.151 2004/03/02 03:21:56 cheshire
492 <rdar://problem/3549576> Properly support "_services._dns-sd._udp" meta-queries
494 Revision 1.150 2004/02/21 02:06:24 cheshire
495 Can't use anonymous unions -- they're non-standard and don't work on all compilers
497 Revision 1.149 2004/02/06 23:04:19 ksekar
498 Basic Dynamic Update support via mDNS_Register (dissabled via
499 UNICAST_REGISTRATION #define)
501 Revision 1.148 2004/02/03 19:47:36 ksekar
502 Added an asynchronous state machine mechanism to uDNS.c, including
503 calls to find the parent zone for a domain name. Changes include code
504 in repository previously dissabled via "#if 0 incomplete". Codepath
505 is currently unused, and will be called to create update records, etc.
507 Revision 1.147 2004/02/03 18:57:35 cheshire
508 Update comment for "IsLocalDomain()"
510 Revision 1.146 2004/01/30 02:20:24 bradley
511 Map inline to __inline when building with Microsoft C compilers since they do not support C99 inline.
513 Revision 1.145 2004/01/29 02:59:17 ksekar
514 Unicast DNS: Changed from a resource record oriented question/response
515 matching to packet based matching. New callback architecture allows
516 collections of records in a response to be processed differently
517 depending on the nature of the request, and allows the same structure
518 to be used for internal and client-driven queries with different processing needs.
520 Revision 1.144 2004/01/28 20:20:45 ksekar
521 Unified ActiveQueries and ActiveInternalQueries lists, using a flag to
522 demux them. Check-in includes work-in-progress code, #ifdef'd out.
524 Revision 1.143 2004/01/28 03:41:00 cheshire
525 <rdar://problem/3541946>: Need ability to do targeted queries as well as multicast queries
527 Revision 1.142 2004/01/28 02:30:07 ksekar
528 Added default Search Domains to unicast browsing, controlled via
529 Networking sharing prefs pane. Stopped sending unicast messages on
530 every interface. Fixed unicast resolving via mach-port API.
532 Revision 1.141 2004/01/27 20:15:22 cheshire
533 <rdar://problem/3541288>: Time to prune obsolete code for listening on port 53
535 Revision 1.140 2004/01/24 23:37:08 cheshire
536 At Kiren's suggestion, made functions to convert mDNSOpaque16s to/from integer values
538 Revision 1.139 2004/01/24 08:46:26 bradley
539 Added InterfaceID<->Index platform interfaces since they are now used by all platforms for the DNS-SD APIs.
541 Revision 1.138 2004/01/24 04:59:15 cheshire
542 Fixes so that Posix/Linux, OS9, Windows, and VxWorks targets build again
544 Revision 1.137 2004/01/24 03:40:56 cheshire
545 Move mDNSAddrIsDNSMulticast() from DNSCommon.h to mDNSEmbeddedAPI.h so clients can use it
547 Revision 1.136 2004/01/24 03:38:27 cheshire
548 Fix minor syntactic error: Headers should use "extern" declarations, not "mDNSexport"
550 Revision 1.135 2004/01/23 23:23:15 ksekar
551 Added TCP support for truncated unicast messages.
553 Revision 1.134 2004/01/22 03:54:11 cheshire
554 Create special meta-interface 'mDNSInterface_ForceMCast' (-2),
555 which means "do this query via multicast, even if it's apparently a unicast domain"
557 Revision 1.133 2004/01/22 03:48:41 cheshire
558 Make sure uDNS client doesn't accidentally use query ID zero
560 Revision 1.132 2004/01/22 03:43:08 cheshire
561 Export constants like mDNSInterface_LocalOnly so that the client layers can use them
563 Revision 1.131 2004/01/21 21:53:18 cheshire
564 <rdar://problem/3448144>: Don't try to receive unicast responses if we're not the first to bind to the UDP port
566 Revision 1.130 2003/12/14 05:05:29 cheshire
567 Add comments explaining mDNS_Init_NoCache and mDNS_Init_ZeroCacheSize
569 Revision 1.129 2003/12/13 03:05:27 ksekar
570 <rdar://problem/3192548>: DynDNS: Unicast query of service records
572 Revision 1.128 2003/12/01 21:44:23 cheshire
573 Add mStatus_BadInterfaceErr = -65552 for consistency with dns_sd.h
575 Revision 1.127 2003/12/01 18:26:37 cheshire
576 Also pack the OpaqueXX union types. Otherwise, on some systems, mDNSOpaque16 is four bytes!
578 Revision 1.126 2003/12/01 18:23:48 cheshire
579 <rdar://problem/3464646>: Scalar size problem in mDNS code on some 64-bit architectures
581 Revision 1.125 2003/11/22 00:18:27 cheshire
582 Add compile-time asserts to verify correct sizes of mDNSu32, mDNSOpaque16, etc.
584 Revision 1.124 2003/11/20 22:59:54 cheshire
585 Changed runtime checks in mDNS.c to be compile-time checks in mDNSEmbeddedAPI.h
586 Thanks to Bob Bradley for suggesting the ingenious compiler trick to make this work.
588 Revision 1.123 2003/11/20 22:53:01 cheshire
589 Add comment about MAX_ESCAPED_DOMAIN_LABEL
591 Revision 1.122 2003/11/20 20:49:53 cheshire
592 Another fix from HP: Use packedstruct macro to ensure proper packing for on-the-wire packet structures
594 Revision 1.121 2003/11/20 05:01:38 cheshire
595 Update comments; add explanation of Advertise/DontAdvertiseLocalAddresses
597 Revision 1.120 2003/11/14 20:59:08 cheshire
598 Clients can't use AssignDomainName macro because mDNSPlatformMemCopy is defined in mDNSPlatformFunctions.h.
599 Best solution is just to combine mDNSEmbeddedAPI.h and mDNSPlatformFunctions.h into a single file.
601 Revision 1.119 2003/11/14 19:47:52 cheshire
602 Define symbol MAX_ESCAPED_DOMAIN_NAME to indicate recommended buffer size for ConvertDomainNameToCString
604 Revision 1.118 2003/11/14 19:18:34 cheshire
605 Move AssignDomainName macro to mDNSEmbeddedAPI.h to that client layers can use it too
607 Revision 1.117 2003/11/08 23:32:24 cheshire
608 Gave name to anonymous struct, to avoid errors on certain compilers.
609 (Thanks to ramaprasad.kr@hp.com for reporting this.)
611 Revision 1.116 2003/11/07 03:32:56 cheshire
612 <rdar://problem/3472153> mDNSResponder delivers answers in inconsistent order
613 This is the real fix. Checkin 1.312 was overly simplistic; Calling GetFreeCacheRR() can sometimes
614 purge records from the cache, causing tail pointer *rp to be stale on return. The correct fix is
615 to maintain a system-wide tail pointer for each cache slot, and then if neccesary GetFreeCacheRR()
616 can update this pointer, so that mDNSCoreReceiveResponse() appends records in the right place.
618 Revision 1.115 2003/09/23 00:53:54 cheshire
619 NumFailedProbes should be unsigned
621 Revision 1.114 2003/08/29 19:44:15 cheshire
622 <rdar://problem/3400967> Traffic reduction: Eliminate synchronized QUs when a new service appears
623 1. Use m->RandomQueryDelay to impose a random delay in the range 0-500ms on queries
624 that already have at least one unique answer in the cache
625 2. For these queries, go straight to QM, skipping QU
627 Revision 1.113 2003/08/21 19:31:58 cheshire
628 Cosmetic: Swap order of fields
630 Revision 1.112 2003/08/21 19:27:36 cheshire
631 <rdar://problem/3387878> Traffic reduction: No need to announce record for longer than TTL
633 Revision 1.111 2003/08/21 02:21:50 cheshire
634 <rdar://problem/3386473> Efficiency: Reduce repeated queries
636 Revision 1.110 2003/08/20 23:39:31 cheshire
637 <rdar://problem/3344098> Review syslog messages, and remove as appropriate
639 Revision 1.109 2003/08/19 22:24:10 cheshire
642 Revision 1.108 2003/08/19 22:20:00 cheshire
643 <rdar://problem/3376721> Don't use IPv6 on interfaces that have a routable IPv4 address configured
644 More minor refinements
646 Revision 1.107 2003/08/19 06:48:25 cheshire
647 <rdar://problem/3376552> Guard against excessive record updates
648 Each record starts with 10 UpdateCredits.
649 Every update consumes one UpdateCredit.
650 UpdateCredits are replenished at a rate of one one per minute, up to a maximum of 10.
651 As the number of UpdateCredits declines, the number of announcements is similarly scaled back.
652 When fewer than 5 UpdateCredits remain, the first announcement is also delayed by an increasing amount.
654 Revision 1.106 2003/08/19 04:49:28 cheshire
655 <rdar://problem/3368159> Interaction between v4, v6 and dual-stack hosts not working quite right
656 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.
657 2. When we see the first v4 (or first v6) member of a group, we re-trigger questions and probes on that interface.
658 3. When we see the last v4 (or v6) member of a group go away, we revalidate all the records received on that interface.
660 Revision 1.105 2003/08/19 02:33:37 cheshire
663 Revision 1.104 2003/08/19 02:31:11 cheshire
664 <rdar://problem/3378386> mDNSResponder overenthusiastic with final expiration queries
665 Final expiration queries now only mark the question for sending on the particular interface
666 pertaining to the record that's expiring.
668 Revision 1.103 2003/08/18 19:05:44 cheshire
669 <rdar://problem/3382423> UpdateRecord not working right
670 Added "newrdlength" field to hold new length of updated rdata
672 Revision 1.102 2003/08/16 03:39:00 cheshire
673 <rdar://problem/3338440> InterfaceID -1 indicates "local only"
675 Revision 1.101 2003/08/15 20:16:02 cheshire
676 <rdar://problem/3366590> mDNSResponder takes too much RPRVT
677 We want to avoid touching the rdata pages, so we don't page them in.
678 1. RDLength was stored with the rdata, which meant touching the page just to find the length.
679 Moved this from the RData to the ResourceRecord object.
680 2. To avoid unnecessarily touching the rdata just to compare it,
681 compute a hash of the rdata and store the hash in the ResourceRecord object.
683 Revision 1.100 2003/08/14 19:29:04 cheshire
684 <rdar://problem/3378473> Include cache records in SIGINFO output
685 Moved declarations of DNSTypeName() and GetRRDisplayString to mDNSEmbeddedAPI.h so daemon.c can use them
687 Revision 1.99 2003/08/14 02:17:05 cheshire
688 <rdar://problem/3375491> Split generic ResourceRecord type into two separate types: AuthRecord and CacheRecord
690 Revision 1.98 2003/08/12 19:56:23 cheshire
693 Revision 1.97 2003/08/12 14:59:27 cheshire
694 <rdar://problem/3374490> Rate-limiting blocks some legitimate responses
695 When setting LastMCTime also record LastMCInterface. When checking LastMCTime to determine
696 whether to suppress the response, also check LastMCInterface to see if it matches.
698 Revision 1.96 2003/08/12 13:57:04 cheshire
699 <rdar://problem/3323817> Improve cache performance
700 Changed the number of hash table slots from 37 to 499
702 Revision 1.95 2003/08/09 00:55:02 cheshire
703 <rdar://problem/3366553> mDNSResponder is taking 20-30% of the CPU
704 Don't scan the whole cache after every packet.
706 Revision 1.94 2003/08/09 00:35:29 cheshire
708 Revision 1.93 2003/08/08 18:55:48 cheshire
709 <rdar://problem/3370365> Guard against time going backwards
711 Revision 1.92 2003/08/08 18:36:04 cheshire
712 <rdar://problem/3344154> Only need to revalidate on interface removal on platforms that have the PhantomInterfaces bug
714 Revision 1.91 2003/08/06 21:33:39 cheshire
715 Fix compiler warnings on PocketPC 2003 (Windows CE)
717 Revision 1.90 2003/08/06 20:30:17 cheshire
718 Add structure definition for rdataMX (not currently used, but good to have it for completeness)
720 Revision 1.89 2003/08/06 18:58:19 cheshire
723 Revision 1.88 2003/07/24 23:45:44 cheshire
724 To eliminate compiler warnings, changed definition of mDNSBool from
725 "unsigned char" to "int", since "int" is in fact truly the type that C uses
726 for the result of comparison operators (a<b) and logical operators (a||b)
728 Revision 1.87 2003/07/22 23:57:20 cheshire
729 Move platform-layer function prototypes from mDNSEmbeddedAPI.h to mDNSPlatformFunctions.h where they belong
731 Revision 1.86 2003/07/20 03:52:02 ksekar
732 <rdar://problem/3320722>: Feature: New DNS-SD APIs (#7875) (mDNSResponder component)
733 Added error type for incompatibility between daemon and client versions
735 Revision 1.85 2003/07/19 03:23:13 cheshire
736 <rdar://problem/2986147> mDNSResponder needs to receive and cache larger records
738 Revision 1.84 2003/07/18 23:52:12 cheshire
739 To improve consistency of field naming, global search-and-replace:
740 NextProbeTime -> NextScheduledProbe
741 NextResponseTime -> NextScheduledResponse
743 Revision 1.83 2003/07/18 00:29:59 cheshire
744 <rdar://problem/3268878> Remove mDNSResponder version from packet header and use HINFO record instead
746 Revision 1.82 2003/07/17 17:35:04 cheshire
747 <rdar://problem/3325583> Rate-limit responses, to guard against packet flooding
749 Revision 1.81 2003/07/16 05:01:36 cheshire
750 Add fields 'LargeAnswers' and 'ExpectUnicastResponse' in preparation for
751 <rdar://problem/3315761> Need to implement "unicast response" request, using top bit of qclass
753 Revision 1.80 2003/07/15 01:55:12 cheshire
754 <rdar://problem/3315777> Need to implement service registration with subtypes
756 Revision 1.79 2003/07/13 02:28:00 cheshire
757 <rdar://problem/3325166> SendResponses didn't all its responses
758 Delete all references to RRInterfaceActive -- it's now superfluous
760 Revision 1.78 2003/07/13 01:47:53 cheshire
761 Fix one error and one warning in the Windows build
763 Revision 1.77 2003/07/11 01:32:38 cheshire
764 Syntactic cleanup (no change to funcationality): Now that we only have one host name,
765 rename field "hostname1" to "hostname", and field "RR_A1" to "RR_A".
767 Revision 1.76 2003/07/11 01:28:00 cheshire
768 <rdar://problem/3161289> No more local.arpa
770 Revision 1.75 2003/07/02 21:19:45 cheshire
771 <rdar://problem/3313413> Update copyright notices, etc., in source code comments
773 Revision 1.74 2003/07/02 02:41:23 cheshire
774 <rdar://problem/2986146> mDNSResponder needs to start with a smaller cache and then grow it as needed
776 Revision 1.73 2003/06/10 04:24:39 cheshire
777 <rdar://problem/3283637> React when we observe other people query unsuccessfully for a record that's in our cache
778 Some additional refinements:
779 Don't try to do this for unicast-response queries
780 better tracking of Qs and KAs in multi-packet KA lists
782 Revision 1.72 2003/06/10 01:46:27 cheshire
783 Add better comments explaining how these data structures are intended to be used from the client layer
785 Revision 1.71 2003/06/07 06:45:05 cheshire
786 <rdar://problem/3283666> No need for multiple machines to all be sending the same queries
788 Revision 1.70 2003/06/07 04:50:53 cheshire
789 <rdar://problem/3283637> React when we observe other people query unsuccessfully for a record that's in our cache
791 Revision 1.69 2003/06/07 04:22:17 cheshire
792 Add MsgBuffer for error log and debug messages
794 Revision 1.68 2003/06/07 01:46:38 cheshire
795 <rdar://problem/3283540> When query produces zero results, call mDNS_Reconfirm() on any antecedent records
797 Revision 1.67 2003/06/07 01:22:14 cheshire
798 <rdar://problem/3283516> mDNSResponder needs an mDNS_Reconfirm() function
800 Revision 1.66 2003/06/07 00:59:43 cheshire
801 <rdar://problem/3283454> Need some randomness to spread queries on the network
803 Revision 1.65 2003/06/06 21:41:11 cheshire
804 For consistency, mDNS_StopQuery() should return an mStatus result, just like all the other mDNSCore routines
806 Revision 1.64 2003/06/06 21:38:55 cheshire
807 Renamed 'NewData' as 'FreshData' (The data may not be new data, just a refresh of data that we
808 already had in our cache. This refreshes our TTL on the data, but the data itself stays the same.)
810 Revision 1.63 2003/06/06 17:20:14 cheshire
811 For clarity, rename question fields name/rrtype/rrclass as qname/qtype/qclass
812 (Global search-and-replace; no functional change to code execution.)
814 Revision 1.62 2003/06/04 01:25:33 cheshire
815 <rdar://problem/3274950> Cannot perform multi-packet known-answer suppression messages
816 Display time interval between first and subsequent queries
818 Revision 1.61 2003/06/03 05:02:16 cheshire
819 <rdar://problem/3277080> Duplicate registrations not handled as efficiently as they should be
821 Revision 1.60 2003/05/31 00:09:49 cheshire
822 <rdar://problem/3274862> Add ability to discover what services are on a network
824 Revision 1.59 2003/05/29 06:11:35 cheshire
825 <rdar://problem/3272214>: Report if there appear to be too many "Resolve" callbacks
827 Revision 1.58 2003/05/29 05:48:06 cheshire
828 Minor fix for when generating printf warnings: mDNS_snprintf arguments are now 3,4
830 Revision 1.57 2003/05/26 03:21:27 cheshire
831 Tidy up address structure naming:
832 mDNSIPAddr => mDNSv4Addr (for consistency with mDNSv6Addr)
833 mDNSAddr.addr.ipv4 => mDNSAddr.ip.v4
834 mDNSAddr.addr.ipv6 => mDNSAddr.ip.v6
836 Revision 1.56 2003/05/26 03:01:27 cheshire
837 <rdar://problem/3268904> sprintf/vsprintf-style functions are unsafe; use snprintf/vsnprintf instead
839 Revision 1.55 2003/05/26 00:47:30 cheshire
840 Comment clarification
842 Revision 1.54 2003/05/24 16:39:48 cheshire
843 <rdar://problem/3268631> SendResponses also needs to handle multihoming better
845 Revision 1.53 2003/05/23 02:15:37 cheshire
846 Fixed misleading use of the term "duplicate suppression" where it should have
847 said "known answer suppression". (Duplicate answer suppression is something
848 different, and duplicate question suppression is yet another thing, so the use
849 of the completely vague term "duplicate suppression" was particularly bad.)
851 Revision 1.52 2003/05/22 02:29:22 cheshire
852 <rdar://problem/2984918> SendQueries needs to handle multihoming better
853 Complete rewrite of SendQueries. Works much better now :-)
855 Revision 1.51 2003/05/21 20:14:55 cheshire
856 Fix comments and warnings
858 Revision 1.50 2003/05/14 07:08:36 cheshire
859 <rdar://problem/3159272> mDNSResponder should be smarter about reconfigurations
860 Previously, when there was any network configuration change, mDNSResponder
861 would tear down the entire list of active interfaces and start again.
862 That was very disruptive, and caused the entire cache to be flushed,
863 and caused lots of extra network traffic. Now it only removes interfaces
864 that have really gone, and only adds new ones that weren't there before.
866 Revision 1.49 2003/05/07 01:49:36 cheshire
867 Remove "const" in ConstructServiceName prototype
869 Revision 1.48 2003/05/07 00:18:44 cheshire
870 Fix typo: "kDNSQClass_Mask" should be "kDNSClass_Mask"
872 Revision 1.47 2003/05/06 00:00:46 cheshire
873 <rdar://problem/3248914> Rationalize naming of domainname manipulation functions
875 Revision 1.46 2003/04/30 20:39:09 cheshire
878 Revision 1.45 2003/04/29 00:40:50 cheshire
879 Fix compiler warnings
881 Revision 1.44 2003/04/26 02:41:56 cheshire
882 <rdar://problem/3241281> Change timenow from a local variable to a structure member
884 Revision 1.43 2003/04/25 01:45:56 cheshire
885 <rdar://problem/3240002> mDNS_RegisterNoSuchService needs to include a host name
887 Revision 1.42 2003/04/15 20:58:31 jgraessl
889 <rdar://problem/3229014> Added a hash to lookup records in the cache.
891 Revision 1.41 2003/04/15 18:09:13 jgraessl
893 <rdar://problem/3228892>
894 Reviewed by: Stuart Cheshire
895 Added code to keep track of when the next cache item will expire so we can
896 call TidyRRCache only when necessary.
898 Revision 1.40 2003/03/29 01:55:19 cheshire
899 <rdar://problem/3212360> mDNSResponder sometimes suffers false self-conflicts when it sees its own packets
900 Solution: Major cleanup of packet timing and conflict handling rules
902 Revision 1.39 2003/03/27 03:30:55 cheshire
903 <rdar://problem/3210018> Name conflicts not handled properly, resulting in memory corruption, and eventual crash
904 Problem was that HostNameCallback() was calling mDNS_DeregisterInterface(), which is not safe in a callback
906 1. Make mDNS_DeregisterInterface() safe to call from a callback
907 2. Make HostNameCallback() use mDNS_DeadvertiseInterface() instead
908 (it never really needed to deregister the interface at all)
910 Revision 1.38 2003/03/15 04:40:36 cheshire
911 Change type called "mDNSOpaqueID" to the more descriptive name "mDNSInterfaceID"
913 Revision 1.37 2003/03/14 21:34:11 cheshire
914 <rdar://problem/3176950> Can't setup and print to Lexmark PS printers via Airport Extreme
915 Increase size of cache rdata from 512 to 768
917 Revision 1.36 2003/03/05 03:38:35 cheshire
918 <rdar://problem/3185731> Bogus error message in console: died or deallocated, but no record of client can be found!
919 Fixed by leaving client in list after conflict, until client explicitly deallocates
921 Revision 1.35 2003/02/21 02:47:54 cheshire
922 <rdar://problem/3099194> mDNSResponder needs performance improvements
923 Several places in the code were calling CacheRRActive(), which searched the entire
924 question list every time, to see if this cache resource record answers any question.
925 Instead, we now have a field "CRActiveQuestion" in the resource record structure
927 Revision 1.34 2003/02/21 01:54:08 cheshire
928 <rdar://problem/3099194> mDNSResponder needs performance improvements
929 Switched to using new "mDNS_Execute" model (see "Implementer Notes.txt")
931 Revision 1.33 2003/02/20 06:48:32 cheshire
932 <rdar://problem/3169535> Xserve RAID needs to do interface-specific registrations
933 Reviewed by: Josh Graessley, Bob Bradley
935 Revision 1.32 2003/01/31 03:35:59 cheshire
936 <rdar://problem/3147097> mDNSResponder sometimes fails to find the correct results
937 When there were *two* active questions in the list, they were incorrectly
938 finding *each other* and *both* being marked as duplicates of another question
940 Revision 1.31 2003/01/29 02:46:37 cheshire
942 A physical interface is identified solely by its InterfaceID (not by IP and type).
943 On a given InterfaceID, mDNSCore may send both v4 and v6 multicasts.
944 In cases where the requested outbound protocol (v4 or v6) is not supported on
945 that InterfaceID, the platform support layer should simply discard that packet.
947 Revision 1.30 2003/01/29 01:47:08 cheshire
948 Rename 'Active' to 'CRActive' or 'InterfaceActive' for improved clarity
950 Revision 1.29 2003/01/28 05:23:43 cheshire
951 <rdar://problem/3147097> mDNSResponder sometimes fails to find the correct results
952 Add 'Active' flag for interfaces
954 Revision 1.28 2003/01/28 01:35:56 cheshire
955 Revise comment about ThisQInterval to reflect new semantics
957 Revision 1.27 2003/01/13 23:49:42 jgraessl
958 Merged changes for the following fixes in to top of tree:
959 <rdar://problem/3086540> computer name changes not handled properly
960 <rdar://problem/3124348> service name changes are not properly handled
961 <rdar://problem/3124352> announcements sent in pairs, failing chattiness test
963 Revision 1.26 2002/12/23 22:13:28 jgraessl
965 Reviewed by: Stuart Cheshire
966 Initial IPv6 support for mDNSResponder.
968 Revision 1.25 2002/09/21 20:44:49 zarzycki
971 Revision 1.24 2002/09/19 23:47:35 cheshire
972 Added mDNS_RegisterNoSuchService() function for assertion of non-existence
973 of a particular named service
975 Revision 1.23 2002/09/19 21:25:34 cheshire
976 mDNS_snprintf() doesn't need to be in a separate file
978 Revision 1.22 2002/09/19 04:20:43 cheshire
979 Remove high-ascii characters that confuse some systems
981 Revision 1.21 2002/09/17 01:06:35 cheshire
982 Change mDNS_AdvertiseLocalAddresses to be a parameter to mDNS_Init()
984 Revision 1.20 2002/09/16 18:41:41 cheshire
985 Merge in license terms from Quinn's copy, in preparation for Darwin release
989 #ifndef __mDNSClientAPI_h
990 #define __mDNSClientAPI_h
992 #include <stdarg.h> // stdarg.h is required for for va_list support for the mDNS_vsnprintf declaration
993 #include "mDNSDebug.h"
999 // ***************************************************************************
1000 // Function scope indicators
1002 // If you see "mDNSlocal" before a function name in a C file, it means the function is not callable outside this file
1004 #define mDNSlocal static
1006 // If you see "mDNSexport" before a symbol in a C file, it means the symbol is exported for use by clients
1007 // For every "mDNSexport" in a C file, there needs to be a corresponding "extern" declaration in some header file
1008 // (When a C file #includes a header file, the "extern" declarations tell the compiler:
1009 // "This symbol exists -- but not necessarily in this C file.")
1014 // ***************************************************************************
1015 // Structure packing macro
1017 // If we're not using GNUC, it's not fatal.
1018 // Most compilers naturally pack the on-the-wire structures correctly anyway, so a plain "struct" is usually fine.
1019 // In the event that structures are not packed correctly, mDNS_Init() will detect this and report an error, so the
1020 // developer will know what's wrong, and can investigate what needs to be done on that compiler to provide proper packing.
1021 #ifndef packedstruct
1022 #if ((__GNUC__ > 2) || ((__GNUC__ == 2) && (__GNUC_MINOR__ >= 9)))
1023 #define packedstruct struct __attribute__((__packed__))
1024 #define packedunion union __attribute__((__packed__))
1026 #define packedstruct struct
1027 #define packedunion union
1031 // ***************************************************************************
1033 #pragma mark - DNS Resource Record class and type constants
1036 typedef enum // From RFC 1035
1038 kDNSClass_IN
= 1, // Internet
1039 kDNSClass_CS
= 2, // CSNET
1040 kDNSClass_CH
= 3, // CHAOS
1041 kDNSClass_HS
= 4, // Hesiod
1042 kDNSClass_NONE
= 254, // Used in DNS UPDATE [RFC 2136]
1044 kDNSClass_Mask
= 0x7FFF,// Multicast DNS uses the bottom 15 bits to identify the record class...
1045 kDNSClass_UniqueRRSet
= 0x8000,// ... and the top bit indicates that all other cached records are now invalid
1047 kDNSQClass_ANY
= 255, // Not a DNS class, but a DNS query class, meaning "all classes"
1048 kDNSQClass_UnicastResponse
= 0x8000 // Top bit set in a question means "unicast response acceptable"
1051 typedef enum // From RFC 1035
1053 kDNSType_A
= 1, // 1 Address
1054 kDNSType_NS
, // 2 Name Server
1055 kDNSType_MD
, // 3 Mail Destination
1056 kDNSType_MF
, // 4 Mail Forwarder
1057 kDNSType_CNAME
, // 5 Canonical Name
1058 kDNSType_SOA
, // 6 Start of Authority
1059 kDNSType_MB
, // 7 Mailbox
1060 kDNSType_MG
, // 8 Mail Group
1061 kDNSType_MR
, // 9 Mail Rename
1062 kDNSType_NULL
, // 10 NULL RR
1063 kDNSType_WKS
, // 11 Well-known-service
1064 kDNSType_PTR
, // 12 Domain name pointer
1065 kDNSType_HINFO
, // 13 Host information
1066 kDNSType_MINFO
, // 14 Mailbox information
1067 kDNSType_MX
, // 15 Mail Exchanger
1068 kDNSType_TXT
, // 16 Arbitrary text string
1070 kDNSType_AAAA
= 28, // 28 IPv6 address
1071 kDNSType_SRV
= 33, // 33 Service record
1072 kDNSType_OPT
= 41, // EDNS0 OPT record
1073 kDNSType_TSIG
= 250, // 250 Transaction Signature
1075 kDNSQType_ANY
= 255 // Not a DNS type, but a DNS query type, meaning "all types"
1078 // ***************************************************************************
1080 #pragma mark - Simple types
1083 // mDNS defines its own names for these common types to simplify portability across
1084 // multiple platforms that may each have their own (different) names for these types.
1085 typedef int mDNSBool
;
1086 typedef signed char mDNSs8
;
1087 typedef unsigned char mDNSu8
;
1088 typedef signed short mDNSs16
;
1089 typedef unsigned short mDNSu16
;
1091 // <http://gcc.gnu.org/onlinedocs/gcc-3.3.3/cpp/Common-Predefined-Macros.html> says
1093 // These macros are defined, with value 1, if (and only if) the compilation is
1094 // for a target where long int and pointer both use 64-bits and int uses 32-bit.
1095 // <http://www.intel.com/software/products/compilers/clin/docs/ug/lin1077.htm> says
1096 // Macro Name __LP64__ Value 1
1097 // A quick Google search for "defined(__LP64__)" OR "#ifdef __LP64__" gives 2590 hits and
1098 // a search for "#if __LP64__" gives only 12, so I think we'll go with the majority and use defined()
1099 #if defined(_LP64) || defined(__LP64__)
1100 typedef signed int mDNSs32
;
1101 typedef unsigned int mDNSu32
;
1102 #elif defined(_ILP64) || defined(__ILP64__)
1103 typedef signed int32 mDNSs32
;
1104 typedef unsigned int32 mDNSu32
;
1106 typedef signed long mDNSs32
;
1107 typedef unsigned long mDNSu32
;
1110 // To enforce useful type checking, we make mDNSInterfaceID be a pointer to a dummy struct
1111 // This way, mDNSInterfaceIDs can be assigned, and compared with each other, but not with other types
1112 // Declaring the type to be the typical generic "void *" would lack this type checking
1113 typedef struct mDNSInterfaceID_dummystruct
{ void *dummy
; } *mDNSInterfaceID
;
1115 // These types are for opaque two- and four-byte identifiers.
1116 // The "NotAnInteger" fields of the unions allow the value to be conveniently passed around in a
1117 // register for the sake of efficiency, and compared for equality or inequality, but don't forget --
1118 // just because it is in a register doesn't mean it is an integer. Operations like greater than,
1119 // less than, add, multiply, increment, decrement, etc., are undefined for opaque identifiers,
1120 // and if you make the mistake of trying to do those using the NotAnInteger field, then you'll
1121 // find you get code that doesn't work consistently on big-endian and little-endian machines.
1122 typedef packedunion
{ mDNSu8 b
[ 2]; mDNSu16 NotAnInteger
; } mDNSOpaque16
;
1123 typedef packedunion
{ mDNSu8 b
[ 4]; mDNSu32 NotAnInteger
; } mDNSOpaque32
;
1124 typedef packedunion
{ mDNSu8 b
[ 6]; mDNSu16 w
[3]; mDNSu32 l
[1]; } mDNSOpaque48
;
1125 typedef packedunion
{ mDNSu8 b
[16]; mDNSu16 w
[8]; mDNSu32 l
[4]; } mDNSOpaque128
;
1127 typedef mDNSOpaque16 mDNSIPPort
; // An IP port is a two-byte opaque identifier (not an integer)
1128 typedef mDNSOpaque32 mDNSv4Addr
; // An IP address is a four-byte opaque identifier (not an integer)
1129 typedef mDNSOpaque128 mDNSv6Addr
; // An IPv6 address is a 16-byte opaque identifier (not an integer)
1130 typedef mDNSOpaque48 mDNSEthAddr
; // An Ethernet address is a six-byte opaque identifier (not an integer)
1134 mDNSAddrType_None
= 0,
1135 mDNSAddrType_IPv4
= 4,
1136 mDNSAddrType_IPv6
= 6,
1137 mDNSAddrType_Unknown
= ~0 // Special marker value used in known answer list recording
1143 union { mDNSv6Addr v6
; mDNSv4Addr v4
; } ip
;
1146 enum { mDNSfalse
= 0, mDNStrue
= 1 };
1152 mStatus_Waiting
= 1,
1153 mStatus_NoError
= 0,
1155 // mDNS return values are in the range FFFE FF00 (-65792) to FFFE FFFF (-65537)
1156 // The top end of the range (FFFE FFFF) is used for error codes;
1157 // the bottom end of the range (FFFE FF00) is used for non-error values;
1160 mStatus_UnknownErr
= -65537, // First value: 0xFFFE FFFF
1161 mStatus_NoSuchNameErr
= -65538,
1162 mStatus_NoMemoryErr
= -65539,
1163 mStatus_BadParamErr
= -65540,
1164 mStatus_BadReferenceErr
= -65541,
1165 mStatus_BadStateErr
= -65542,
1166 mStatus_BadFlagsErr
= -65543,
1167 mStatus_UnsupportedErr
= -65544,
1168 mStatus_NotInitializedErr
= -65545,
1169 mStatus_NoCache
= -65546,
1170 mStatus_AlreadyRegistered
= -65547,
1171 mStatus_NameConflict
= -65548,
1172 mStatus_Invalid
= -65549,
1173 mStatus_Firewall
= -65550,
1174 mStatus_Incompatible
= -65551,
1175 mStatus_BadInterfaceErr
= -65552,
1176 mStatus_Refused
= -65553,
1177 mStatus_NoSuchRecord
= -65554,
1178 mStatus_NoAuth
= -65555,
1179 mStatus_NoSuchKey
= -65556,
1180 mStatus_NATTraversal
= -65557,
1181 mStatus_DoubleNAT
= -65558,
1182 mStatus_BadTime
= -65559,
1183 mStatus_BadSig
= -65560, // while we define this per RFC 2845, BIND 9 returns Refused for bad/missing signatures
1184 mStatus_BadKey
= -65561,
1185 mStatus_TransientErr
= -65562, // transient failures, e.g. sending packets shortly after a network transition or wake from sleep
1186 // -65563 to -65786 currently unused; available for allocation
1188 // tcp connection status
1189 mStatus_ConnPending
= -65787,
1190 mStatus_ConnFailed
= -65788,
1191 mStatus_ConnEstablished
= -65789,
1193 // Non-error values:
1194 mStatus_GrowCache
= -65790,
1195 mStatus_ConfigChanged
= -65791,
1196 mStatus_MemFree
= -65792 // Last value: 0xFFFE FF00
1198 // mStatus_MemFree is the last legal mDNS error code, at the end of the range allocated for mDNS
1201 typedef mDNSs32 mStatus
;
1203 // RFC 1034/1035 specify that a domain label consists of a length byte plus up to 63 characters
1204 #define MAX_DOMAIN_LABEL 63
1205 typedef struct { mDNSu8 c
[ 64]; } domainlabel
; // One label: length byte and up to 63 characters
1207 // RFC 1034/1035 specify that a domain name, including length bytes, data bytes, and terminating zero, may be up to 255 bytes long
1208 #define MAX_DOMAIN_NAME 255
1209 typedef struct { mDNSu8 c
[256]; } domainname
; // Up to 255 bytes of length-prefixed domainlabels
1211 typedef struct { mDNSu8 c
[256]; } UTF8str255
; // Null-terminated C string
1213 // The longest legal textual form of a DNS name is 1005 bytes, including the C-string terminating NULL at the end.
1215 // When a native domainname object is converted to printable textual form using ConvertDomainNameToCString(),
1216 // non-printing characters are represented in the conventional DNS way, as '\ddd', where ddd is a three-digit decimal number.
1217 // The longest legal domain name is 255 bytes, in the form of four labels as shown below:
1218 // Length byte, 63 data bytes, length byte, 63 data bytes, length byte, 63 data bytes, length byte, 61 data bytes, zero byte.
1219 // Each label is encoded textually as characters followed by a trailing dot.
1220 // If every character has to be represented as a four-byte escape sequence, then this makes the maximum textual form four labels
1221 // plus the C-string terminating NULL as shown below:
1222 // 63*4+1 + 63*4+1 + 63*4+1 + 61*4+1 + 1 = 1005.
1223 // Note that MAX_ESCAPED_DOMAIN_LABEL is not normally used: If you're only decoding a single label, escaping is usually not required.
1224 // It is for domain names, where dots are used as label separators, that proper escaping is vital.
1225 #define MAX_ESCAPED_DOMAIN_LABEL 254
1226 #define MAX_ESCAPED_DOMAIN_NAME 1005
1228 // Most records have a TTL of 75 minutes, so that their 80% cache-renewal query occurs once per hour.
1229 // For records containing a hostname (in the name on the left, or in the rdata on the right),
1230 // like A, AAAA, reverse-mapping PTR, and SRV, we use a two-minute TTL by default, because we don't want
1231 // them to hang around for too long in the cache if the host in question crashes or otherwise goes away.
1232 // Wide-area service discovery records have a very short TTL to aviod poluting intermediate caches with
1233 // dynamic records. When discovered via Long Lived Queries (with change notifications), resource record
1234 // TTLs can be safely ignored.
1236 #define kStandardTTL (3600UL * 100 / 80)
1237 #define kHostNameTTL 120UL
1238 #define kWideAreaTTL 3
1240 #define DefaultTTLforRRType(X) (((X) == kDNSType_A || (X) == kDNSType_AAAA || (X) == kDNSType_SRV) ? kHostNameTTL : kStandardTTL)
1242 // ***************************************************************************
1244 #pragma mark - DNS Message structures
1247 #define mDNS_numZones numQuestions
1248 #define mDNS_numPrereqs numAnswers
1249 #define mDNS_numUpdates numAuthorities
1251 typedef packedstruct
1255 mDNSu16 numQuestions
;
1257 mDNSu16 numAuthorities
;
1258 mDNSu16 numAdditionals
;
1261 // We can send and receive packets up to 9000 bytes (Ethernet Jumbo Frame size, if that ever becomes widely used)
1262 // However, in the normal case we try to limit packets to 1500 bytes so that we don't get IP fragmentation on standard Ethernet
1263 // 40 (IPv6 header) + 8 (UDP header) + 12 (DNS message header) + 1440 (DNS message body) = 1500 total
1264 #define AbsoluteMaxDNSMessageData 8940
1265 #define NormalMaxDNSMessageData 1440
1266 typedef packedstruct
1268 DNSMessageHeader h
; // Note: Size 12 bytes
1269 mDNSu8 data
[AbsoluteMaxDNSMessageData
]; // 40 (IPv6) + 8 (UDP) + 12 (DNS header) + 8940 (data) = 9000
1272 // ***************************************************************************
1274 #pragma mark - Resource Record structures
1277 // Authoritative Resource Records:
1278 // There are four basic types: Shared, Advisory, Unique, Known Unique
1280 // * Shared Resource Records do not have to be unique
1281 // -- Shared Resource Records are used for DNS-SD service PTRs
1282 // -- It is okay for several hosts to have RRs with the same name but different RDATA
1283 // -- We use a random delay on responses to reduce collisions when all the hosts respond to the same query
1284 // -- These RRs typically have moderately high TTLs (e.g. one hour)
1285 // -- These records are announced on startup and topology changes for the benefit of passive listeners
1286 // -- These records send a goodbye packet when deregistering
1288 // * Advisory Resource Records are like Shared Resource Records, except they don't send a goodbye packet
1290 // * Unique Resource Records should be unique among hosts within any given mDNS scope
1291 // -- The majority of Resource Records are of this type
1292 // -- If two entities on the network have RRs with the same name but different RDATA, this is a conflict
1293 // -- Responses may be sent immediately, because only one host should be responding to any particular query
1294 // -- These RRs typically have low TTLs (e.g. a few minutes)
1295 // -- On startup and after topology changes, a host issues queries to verify uniqueness
1297 // * Known Unique Resource Records are treated like Unique Resource Records, except that mDNS does
1298 // not have to verify their uniqueness because this is already known by other means (e.g. the RR name
1299 // is derived from the host's IP or Ethernet address, which is already known to be a unique identifier).
1301 // Summary of properties of different record types:
1302 // Probe? Does this record type send probes before announcing?
1303 // Conflict? Does this record type react if we observe an apparent conflict?
1304 // Goodbye? Does this record type send a goodbye packet on departure?
1306 // Probe? Conflict? Goodbye? Notes
1307 // Unregistered Should not appear in any list (sanity check value)
1308 // Shared No No Yes e.g. Service PTR record
1309 // Deregistering No No Yes Shared record about to announce its departure and leave the list
1310 // Advisory No No No
1311 // Unique Yes Yes No Record intended to be unique -- will probe to verify
1312 // Verified Yes Yes No Record has completed probing, and is verified unique
1313 // KnownUnique No Yes No Record is assumed by other means to be unique
1315 // Valid lifecycle of a record:
1316 // Unregistered -> Shared -> Deregistering -(goodbye)-> Unregistered
1317 // Unregistered -> Advisory -> Unregistered
1318 // Unregistered -> Unique -(probe)-> Verified -> Unregistered
1319 // Unregistered -> KnownUnique -> Unregistered
1321 // Each Authoritative kDNSRecordType has only one bit set. This makes it easy to quickly see if a record
1322 // is one of a particular set of types simply by performing the appropriate bitwise masking operation.
1324 // Cache Resource Records (received from the network):
1325 // There are four basic types: Answer, Unique Answer, Additional, Unique Additional
1326 // Bit 7 (the top bit) of kDNSRecordType is always set for Cache Resource Records; always clear for Authoritative Resource Records
1327 // Bit 6 (value 0x40) is set for answer records; clear for additional records
1328 // Bit 5 (value 0x20) is set for records received with the kDNSClass_UniqueRRSet
1332 kDNSRecordTypeUnregistered
= 0x00, // Not currently in any list
1333 kDNSRecordTypeDeregistering
= 0x01, // Shared record about to announce its departure and leave the list
1335 kDNSRecordTypeUnique
= 0x02, // Will become a kDNSRecordTypeVerified when probing is complete
1337 kDNSRecordTypeAdvisory
= 0x04, // Like Shared, but no goodbye packet
1338 kDNSRecordTypeShared
= 0x08, // Shared means record name does not have to be unique -- use random delay on responses
1340 kDNSRecordTypeVerified
= 0x10, // Unique means mDNS should check that name is unique (and then send immediate responses)
1341 kDNSRecordTypeKnownUnique
= 0x20, // Known Unique means mDNS can assume name is unique without checking
1342 // For Dynamic Update records, Known Unique means the record must already exist on the server.
1343 kDNSRecordTypeUniqueMask
= (kDNSRecordTypeUnique
| kDNSRecordTypeVerified
| kDNSRecordTypeKnownUnique
),
1344 kDNSRecordTypeActiveMask
= (kDNSRecordTypeAdvisory
| kDNSRecordTypeShared
| kDNSRecordTypeVerified
| kDNSRecordTypeKnownUnique
),
1346 kDNSRecordTypePacketAdd
= 0x80, // Received in the Additional Section of a DNS Response
1347 kDNSRecordTypePacketAddUnique
= 0x90, // Received in the Additional Section of a DNS Response with kDNSClass_UniqueRRSet set
1348 kDNSRecordTypePacketAuth
= 0xA0, // Received in the Authorities Section of a DNS Response
1349 kDNSRecordTypePacketAuthUnique
= 0xB0, // Received in the Authorities Section of a DNS Response with kDNSClass_UniqueRRSet set
1350 kDNSRecordTypePacketAns
= 0xC0, // Received in the Answer Section of a DNS Response
1351 kDNSRecordTypePacketAnsUnique
= 0xD0, // Received in the Answer Section of a DNS Response with kDNSClass_UniqueRRSet set
1353 kDNSRecordTypePacketAnsMask
= 0x40, // True for PacketAns and PacketAnsUnique
1354 kDNSRecordTypePacketUniqueMask
= 0x10 // True for PacketAddUnique, PacketAnsUnique, PacketAuthUnique
1357 typedef packedstruct
{ mDNSu16 priority
; mDNSu16 weight
; mDNSIPPort port
; domainname target
; } rdataSRV
;
1358 typedef packedstruct
{ mDNSu16 preference
; domainname exchange
; } rdataMX
;
1359 typedef packedstruct
1363 mDNSs32 serial
; // Modular counter; increases when zone changes
1364 mDNSu32 refresh
; // Time in seconds that a slave waits after successful replication of the database before it attempts replication again
1365 mDNSu32 retry
; // Time in seconds that a slave waits after an unsuccessful replication attempt before it attempts replication again
1366 mDNSu32 expire
; // Time in seconds that a slave holds on to old data while replication attempts remain unsuccessful
1367 mDNSu32 min
; // Nominally the minimum record TTL for this zone, in seconds; also used for negative caching.
1370 typedef packedstruct
1379 #define LLQ_OPTLEN ((3 * sizeof(mDNSu16)) + 8 + sizeof(mDNSu32))
1380 // Windows adds pad bytes to sizeof(LLQOptData). Use this macro when setting length fields or validating option rdata from
1381 // off the wire. Use sizeof(LLQOptData) when dealing with structures (e.g. memcpy). Never memcpy between on-the-wire
1382 // representation and a structure
1384 // NOTE: rdataOpt format may be repeated an arbitrary number of times in a single resource record
1385 typedef packedstruct
1389 union { LLQOptData llq
; mDNSu32 lease
; } OptData
;
1392 // StandardAuthRDSize is 264 (256+8), which is large enough to hold a maximum-sized SRV record
1393 // MaximumRDSize is 8K the absolute maximum we support (at least for now)
1394 #define StandardAuthRDSize 264
1395 #define MaximumRDSize 8192
1397 // InlineCacheRDSize is 68
1398 // Records received from the network with rdata this size or less have their rdata stored right in the CacheRecord object
1399 // Records received from the network with rdata larger than this have additional storage allocated for the rdata
1400 // A quick unscientific sample from a busy network at Apple with lots of machines revealed this:
1401 // 1461 records in cache
1402 // 292 were one-byte TXT records
1403 // 136 were four-byte A records
1404 // 184 were sixteen-byte AAAA records
1405 // 780 were various PTR, TXT and SRV records from 12-64 bytes
1406 // Only 69 records had rdata bigger than 64 bytes
1407 // Note that since CacheRecord object and a CacheGroup object are allocated out of the same pool, it's sensible to
1408 // have them both be the same size. Making one smaller without making the other smaller won't actually save any memory.
1409 #define InlineCacheRDSize 68
1411 #define InlineCacheGroupNameSize 144
1415 mDNSu8 data
[StandardAuthRDSize
];
1416 mDNSv4Addr ipv4
; // For 'A' record
1417 mDNSv6Addr ipv6
; // For 'AAAA' record
1418 domainname name
; // For PTR, NS, and CNAME records
1419 UTF8str255 txt
; // For TXT record
1420 rdataSRV srv
; // For SRV record
1421 rdataMX mx
; // For MX record
1422 rdataSOA soa
; // For SOA record
1423 rdataOpt opt
; // For eDNS0 opt record
1428 mDNSu16 MaxRDLength
; // Amount of storage allocated for rdata (usually sizeof(RDataBody))
1431 #define sizeofRDataHeader (sizeof(RData) - sizeof(RDataBody))
1433 typedef struct AuthRecord_struct AuthRecord
;
1434 typedef struct CacheRecord_struct CacheRecord
;
1435 typedef struct CacheGroup_struct CacheGroup
;
1436 typedef struct DNSQuestion_struct DNSQuestion
;
1437 typedef struct mDNS_struct mDNS
;
1438 typedef struct mDNS_PlatformSupport_struct mDNS_PlatformSupport
;
1439 typedef struct NATTraversalInfo_struct NATTraversalInfo
;
1441 // Note: Within an mDNSRecordCallback mDNS all API calls are legal except mDNS_Init(), mDNS_Close(), mDNS_Execute()
1442 typedef void mDNSRecordCallback(mDNS
*const m
, AuthRecord
*const rr
, mStatus result
);
1445 // Restrictions: An mDNSRecordUpdateCallback may not make any mDNS API calls.
1446 // The intent of this callback is to allow the client to free memory, if necessary.
1447 // The internal data structures of the mDNS code may not be in a state where mDNS API calls may be made safely.
1448 typedef void mDNSRecordUpdateCallback(mDNS
*const m
, AuthRecord
*const rr
, RData
*OldRData
);
1452 mDNSu8 RecordType
; // See enum above
1453 mDNSInterfaceID InterfaceID
; // Set if this RR is specific to one interface
1454 // For records received off the wire, InterfaceID is *always* set to the receiving interface
1455 // For our authoritative records, InterfaceID is usually zero, except for those few records
1456 // that are interface-specific (e.g. address records, especially linklocal addresses)
1460 mDNSu32 rroriginalttl
; // In seconds
1461 mDNSu16 rdlength
; // Size of the raw rdata, in bytes
1462 mDNSu16 rdestimate
; // Upper bound on size of rdata after name compression
1463 mDNSu32 namehash
; // Name-based (i.e. case-insensitive) hash of name
1464 mDNSu32 rdatahash
; // For rdata containing domain name (e.g. PTR, SRV, CNAME etc.), case-insensitive name hash
1465 // else, for all other rdata, 32-bit hash of the raw rdata
1466 // Note: This requirement is important. Various routines like AddAdditionalsToResponseList(),
1467 // ReconfirmAntecedents(), etc., use rdatahash as a pre-flight check to see
1468 // whether it's worth doing a full SameDomainName() call. If the rdatahash
1469 // is not a correct case-insensitive name hash, they'll get false negatives.
1470 RData
*rdata
; // Pointer to storage for this rdata
1473 // Unless otherwise noted, states may apply to either independent record registrations or service registrations
1476 regState_FetchingZoneData
= 1, // getting info - update not sent
1477 regState_Pending
= 2, // update sent, reply not received
1478 regState_Registered
= 3, // update sent, reply received
1479 regState_DeregPending
= 4, // dereg sent, reply not received
1480 regState_DeregDeferred
= 5, // dereg requested while in Pending state - send dereg AFTER registration is confirmed
1481 regState_Cancelled
= 6, // update not sent, reg. cancelled by client
1482 regState_Unregistered
= 8, // not in any list
1483 regState_Refresh
= 9, // outstanding refresh (or target change) message
1484 regState_NATMap
= 10, // establishing NAT port mapping or learning public address
1485 regState_UpdatePending
= 11, // update in flight as result of mDNS_Update call
1486 regState_NoTarget
= 12, // service registration pending registration of hostname (ServiceRegistrations only)
1487 regState_ExtraQueued
= 13, // extra record to be registered upon completion of service registration (RecordRegistrations only)
1488 regState_NATError
= 14 // unable to complete NAT traversal
1491 // context for both ServiceRecordSet and individual AuthRec structs
1494 // registration/lease state
1496 mDNSBool lease
; // dynamic update contains (should contain) lease option
1497 mDNSs32 expire
; // expiration of lease (-1 for static)
1498 mDNSBool TestForSelfConflict
; // on name conflict, check if we're just seeing our own orphaned records
1500 // identifier to match update request and response
1504 domainname zone
; // the zone that is updated
1505 mDNSAddr ns
; // primary name server for the record's zone !!!KRS not technically correct to cache longer than TTL
1506 mDNSIPPort port
; // port on which server accepts dynamic updates
1508 // NAT traversal context
1509 NATTraversalInfo
*NATinfo
; // may be NULL
1511 // state for deferred operations
1512 mDNSBool ClientCallbackDeferred
; // invoke client callback on completion of pending operation(s)
1513 mStatus DeferredStatus
; // status to deliver when above flag is set
1514 mDNSBool SRVUpdateDeferred
; // do we need to change target or port once current operation completes?
1515 mDNSBool SRVChanged
; // temporarily deregistered service because its SRV target or port changed
1517 // uDNS_UpdateRecord support fields
1518 RData
*OrigRData
; mDNSu16 OrigRDLen
; // previously registered, being deleted
1519 RData
*InFlightRData
; mDNSu16 InFlightRDLen
; // currently being registered
1520 RData
*QueuedRData
; mDNSu16 QueuedRDLen
; // if the client call Update while an update is in flight, we must finish the
1521 // pending operation (re-transmitting if necessary) THEN register the queued update
1522 mDNSRecordUpdateCallback
*UpdateRDCallback
; // client callback to free old rdata
1525 struct AuthRecord_struct
1527 // For examples of how to set up this structure for use in mDNS_Register(),
1528 // see mDNS_AdvertiseInterface() or mDNS_RegisterService().
1529 // Basically, resrec and persistent metadata need to be set up before calling mDNS_Register().
1530 // mDNS_SetupResourceRecord() is avaliable as a helper routine to set up most fields to sensible default values for you
1532 AuthRecord
*next
; // Next in list; first element of structure for efficiency reasons
1533 // Field Group 1: Common ResourceRecord fields
1534 ResourceRecord resrec
;
1535 uDNS_RegInfo uDNS_info
;
1537 // Field Group 2: Persistent metadata for Authoritative Records
1538 AuthRecord
*Additional1
; // Recommended additional record to include in response
1539 AuthRecord
*Additional2
; // Another additional
1540 AuthRecord
*DependentOn
; // This record depends on another for its uniqueness checking
1541 AuthRecord
*RRSet
; // This unique record is part of an RRSet
1542 mDNSRecordCallback
*RecordCallback
; // Callback function to call for state changes, and to free memory asynchronously on deregistration
1543 void *RecordContext
; // Context parameter for the callback function
1544 mDNSu8 HostTarget
; // Set if the target of this record (PTR, CNAME, SRV, etc.) is our host name
1545 mDNSu8 AllowRemoteQuery
; // Set if we allow hosts not on the local link to query this record
1546 mDNSu8 ForceMCast
; // Set by client to advertise solely via multicast, even for apparently unicast names
1548 // Field Group 3: Transient state for Authoritative Records
1549 mDNSu8 Acknowledged
; // Set if we've given the success callback to the client
1550 mDNSu8 ProbeCount
; // Number of probes remaining before this record is valid (kDNSRecordTypeUnique)
1551 mDNSu8 AnnounceCount
; // Number of announcements remaining (kDNSRecordTypeShared)
1552 mDNSu8 RequireGoodbye
; // Set if this RR has been announced on the wire and will require a goodbye packet
1553 mDNSu8 LocalAnswer
; // Set if this RR has been delivered to LocalOnly questions
1554 mDNSu8 IncludeInProbe
; // Set if this RR is being put into a probe right now
1555 mDNSInterfaceID ImmedAnswer
; // Someone on this interface issued a query we need to answer (all-ones for all interfaces)
1556 mDNSu8 ImmedUnicast
; // Set if we may send our response directly via unicast to the requester
1557 #if MDNS_LOG_ANSWER_SUPPRESSION_TIMES
1558 mDNSs32 ImmedAnswerMarkTime
;
1560 mDNSInterfaceID ImmedAdditional
; // Hint that we might want to also send this record, just to be helpful
1561 mDNSInterfaceID SendRNow
; // The interface this query is being sent on right now
1562 mDNSv4Addr v4Requester
; // Recent v4 query for this record, or all-ones if more than one recent query
1563 mDNSv6Addr v6Requester
; // Recent v6 query for this record, or all-ones if more than one recent query
1564 AuthRecord
*NextResponse
; // Link to the next element in the chain of responses to generate
1565 const mDNSu8
*NR_AnswerTo
; // Set if this record was selected by virtue of being a direct answer to a question
1566 AuthRecord
*NR_AdditionalTo
; // Set if this record was selected by virtue of being additional to another
1567 mDNSs32 ThisAPInterval
; // In platform time units: Current interval for announce/probe
1568 mDNSs32 AnnounceUntil
; // In platform time units: Creation time + TTL
1569 mDNSs32 LastAPTime
; // In platform time units: Last time we sent announcement/probe
1570 mDNSs32 LastMCTime
; // Last time we multicast this record (used to guard against packet-storm attacks)
1571 mDNSInterfaceID LastMCInterface
; // Interface this record was multicast on at the time LastMCTime was recorded
1572 RData
*NewRData
; // Set if we are updating this record with new rdata
1573 mDNSu16 newrdlength
; // ... and the length of the new RData
1574 mDNSRecordUpdateCallback
*UpdateCallback
;
1575 mDNSu32 UpdateCredits
; // Token-bucket rate limiting of excessive updates
1576 mDNSs32 NextUpdateCredit
; // Time next token is added to bucket
1577 mDNSs32 UpdateBlocked
; // Set if update delaying is in effect
1579 domainname namestorage
;
1580 RData rdatastorage
; // Normally the storage is right here, except for oversized records
1581 // rdatastorage MUST be the last thing in the structure -- when using oversized AuthRecords, extra bytes
1582 // are appended after the end of the AuthRecord, logically augmenting the size of the rdatastorage
1583 // DO NOT ADD ANY MORE FIELDS HERE
1586 // Wrapper struct for Auth Records for higher-level code that cannot use the AuthRecord's ->next pointer field
1587 typedef struct ARListElem
1589 struct ARListElem
*next
;
1590 AuthRecord ar
; // Note: Must be last struct in field to accomodate oversized AuthRecords
1593 struct CacheGroup_struct
// Header object for a list of CacheRecords with the same name
1595 CacheGroup
*next
; // Next CacheGroup object in this hash table bucket
1596 mDNSu32 namehash
; // Name-based (i.e. case insensitive) hash of name
1597 CacheRecord
*members
; // List of CacheRecords with this same name
1598 CacheRecord
**rrcache_tail
; // Tail end of that list
1599 domainname
*name
; // Common name for all CacheRecords in this list
1600 mDNSu8 namestorage
[InlineCacheGroupNameSize
];
1603 struct CacheRecord_struct
1605 CacheRecord
*next
; // Next in list; first element of structure for efficiency reasons
1606 ResourceRecord resrec
;
1608 // Transient state for Cache Records
1609 CacheRecord
*NextInKAList
; // Link to the next element in the chain of known answers to send
1610 mDNSs32 TimeRcvd
; // In platform time units
1611 mDNSs32 DelayDelivery
; // Set if we want to defer delivery of this answer to local clients
1612 mDNSs32 NextRequiredQuery
; // In platform time units
1613 mDNSs32 LastUsed
; // In platform time units
1614 DNSQuestion
*CRActiveQuestion
; // Points to an active question referencing this answer
1615 mDNSu32 UnansweredQueries
; // Number of times we've issued a query for this record without getting an answer
1616 mDNSs32 LastUnansweredTime
; // In platform time units; last time we incremented UnansweredQueries
1617 mDNSu32 MPUnansweredQ
; // Multi-packet query handling: Number of times we've seen a query for this record
1618 mDNSs32 MPLastUnansweredQT
; // Multi-packet query handling: Last time we incremented MPUnansweredQ
1619 mDNSu32 MPUnansweredKA
; // Multi-packet query handling: Number of times we've seen this record in a KA list
1620 mDNSBool MPExpectingKA
; // Multi-packet query handling: Set when we increment MPUnansweredQ; allows one KA
1621 CacheRecord
*NextInCFList
; // Set if this is in the list of records we just received with the cache flush bit set
1623 struct { mDNSu16 MaxRDLength
; mDNSu8 data
[InlineCacheRDSize
]; } rdatastorage
; // Storage for small records is right here
1626 // Storage sufficient to hold either a CacheGroup header or a CacheRecord
1627 typedef union CacheEntity_union CacheEntity
;
1628 union CacheEntity_union
{ CacheEntity
*next
; CacheGroup cg
; CacheRecord cr
; };
1633 mDNSu8 _extradata
[MaximumRDSize
-InlineCacheRDSize
]; // Glue on the necessary number of extra bytes
1634 domainname namestorage
; // Needs to go *after* the extra rdata bytes
1637 typedef struct uDNS_HostnameInfo
1639 struct uDNS_HostnameInfo
*next
;
1641 AuthRecord
*arv4
; // registered IPv4 address record
1642 AuthRecord
*arv6
; // registered IPv6 address record
1643 mDNSRecordCallback
*StatusCallback
; // callback to deliver success or error code to client layer
1644 const void *StatusContext
; // Client Context
1645 } uDNS_HostnameInfo
;
1647 typedef struct DNSServer
1649 struct DNSServer
*next
;
1651 domainname domain
; // name->server matching for "split dns"
1652 int flag
; // temporary marker for list intersection
1655 typedef struct NetworkInterfaceInfo_struct NetworkInterfaceInfo
;
1657 // A NetworkInterfaceInfo_struct serves two purposes:
1658 // 1. It holds the address, PTR and HINFO records to advertise a given IP address on a given physical interface
1659 // 2. It tells mDNSCore which physical interfaces are available; each physical interface has its own unique InterfaceID.
1660 // Since there may be multiple IP addresses on a single physical interface,
1661 // there may be multiple NetworkInterfaceInfo_structs with the same InterfaceID.
1662 // In this case, to avoid sending the same packet n times, when there's more than one
1663 // struct with the same InterfaceID, mDNSCore picks one member of the set to be the
1664 // active representative of the set; all others have the 'InterfaceActive' flag unset.
1666 struct NetworkInterfaceInfo_struct
1668 // Internal state fields. These are used internally by mDNSCore; the client layer needn't be concerned with them.
1669 NetworkInterfaceInfo
*next
;
1671 mDNSBool InterfaceActive
; // Set if interface is sending & receiving packets (see comment above)
1672 mDNSBool IPv4Available
; // If InterfaceActive, set if v4 available on this InterfaceID
1673 mDNSBool IPv6Available
; // If InterfaceActive, set if v6 available on this InterfaceID
1675 // Standard AuthRecords that every Responder host should have (one per active IP address)
1676 AuthRecord RR_A
; // 'A' or 'AAAA' (address) record for our ".local" name
1677 AuthRecord RR_PTR
; // PTR (reverse lookup) record
1678 AuthRecord RR_HINFO
;
1680 // Client API fields: The client must set up these fields *before* calling mDNS_RegisterInterface()
1681 mDNSInterfaceID InterfaceID
; // Identifies physical interface; MUST NOT be 0, -1, or -2
1682 mDNSAddr ip
; // The IPv4 or IPv6 address to advertise
1684 char ifname
[64]; // Windows uses a GUID string for the interface name, which doesn't fit in 16 bytes
1685 mDNSBool Advertise
; // False if you are only searching on this interface
1686 mDNSBool McastTxRx
; // Send/Receive multicast on this { InterfaceID, address family } ?
1689 typedef struct ExtraResourceRecord_struct ExtraResourceRecord
;
1690 struct ExtraResourceRecord_struct
1692 ExtraResourceRecord
*next
;
1693 mDNSu32 ClientID
; // Opaque ID field to be used by client to map an AddRecord call to a set of Extra records
1695 // Note: Add any additional fields *before* the AuthRecord in this structure, not at the end.
1696 // In some cases clients can allocate larger chunks of memory and set r->rdata->MaxRDLength to indicate
1697 // that this extra memory is available, which would result in any fields after the AuthRecord getting smashed
1700 // Note: Within an mDNSServiceCallback mDNS all API calls are legal except mDNS_Init(), mDNS_Close(), mDNS_Execute()
1701 typedef struct ServiceRecordSet_struct ServiceRecordSet
;
1702 typedef void mDNSServiceCallback(mDNS
*const m
, ServiceRecordSet
*const sr
, mStatus result
);
1703 struct ServiceRecordSet_struct
1705 // Internal state fields. These are used internally by mDNSCore; the client layer needn't be concerned with them.
1706 // No fields need to be set up by the client prior to calling mDNS_RegisterService();
1707 // all required data is passed as parameters to that function.
1708 ServiceRecordSet
*next
;
1709 uDNS_RegInfo uDNS_info
;
1710 mDNSServiceCallback
*ServiceCallback
;
1711 void *ServiceContext
;
1712 ExtraResourceRecord
*Extras
; // Optional list of extra AuthRecords attached to this service registration
1713 mDNSu32 NumSubTypes
;
1714 AuthRecord
*SubTypes
;
1715 mDNSBool Conflict
; // Set if this record set was forcibly deregistered because of a conflict
1716 domainname Host
; // Set if this service record does not use the standard target host name
1717 AuthRecord RR_ADV
; // e.g. _services._dns-sd._udp.local. PTR _printer._tcp.local.
1718 AuthRecord RR_PTR
; // e.g. _printer._tcp.local. PTR Name._printer._tcp.local.
1719 AuthRecord RR_SRV
; // e.g. Name._printer._tcp.local. SRV 0 0 port target
1720 AuthRecord RR_TXT
; // e.g. Name._printer._tcp.local. TXT PrintQueueName
1721 // Don't add any fields after AuthRecord RR_TXT.
1722 // This is where the implicit extra space goes if we allocate a ServiceRecordSet containing an oversized RR_TXT record
1725 // ***************************************************************************
1727 #pragma mark - Question structures
1730 // We record the last eight instances of each duplicate query
1731 // This gives us v4/v6 on each of Ethernet/AirPort and Firewire, and two free slots "for future expansion"
1732 // If the host has more active interfaces that this it is not fatal -- duplicate question suppression will degrade gracefully.
1733 // Since we will still remember the last eight, the busiest interfaces will still get the effective duplicate question suppression.
1734 #define DupSuppressInfoSize 8
1739 mDNSInterfaceID InterfaceID
;
1740 mDNSs32 Type
; // v4 or v6?
1747 LLQ_GetZoneInfo
= 1,
1748 LLQ_InitialRequest
= 2,
1749 LLQ_SecondaryRequest
= 3,
1752 LLQ_Established
= 6,
1754 LLQ_SuspendDeferred
= 8, // suspend once we get zone info
1755 LLQ_SuspendedPoll
= 9, // suspended from polling state
1756 LLQ_NatMapWait
= 10,
1758 // Established/error states
1769 mDNSIPPort servPort
;
1770 DNSQuestion
*question
;
1771 mDNSu32 origLease
; // seconds (relative)
1772 mDNSs32 retry
; // ticks (absolute)
1773 mDNSs32 expire
; // ticks (absolute)
1776 mDNSBool deriveRemovesOnResume
;
1777 mDNSBool NATMap
; // does this LLQ use the global LLQ NAT mapping?
1781 #define kDNSOpt_LLQ 1
1782 #define kDNSOpt_Lease 2
1784 #define kLLQ_DefLease 7200 // 2 hours
1785 #define kLLQ_MAX_TRIES 3 // retry an operation 3 times max
1786 #define kLLQ_INIT_RESEND 2 // resend an un-ack'd packet after 2 seconds, then double for each additional
1787 #define kLLQ_DEF_RETRY 1800 // retry a failed operation after 30 minutes
1788 // LLQ Operation Codes
1789 #define kLLQOp_Setup 1
1790 #define kLLQOp_Refresh 2
1791 #define kLLQOp_Event 3
1793 #define LLQ_OPT_RDLEN ((2 * sizeof(mDNSu16)) + LLQ_OPTLEN)
1794 #define LEASE_OPT_RDLEN (2 * sizeof(mDNSu16)) + sizeof(mDNSs32)
1800 LLQErr_ServFull
= 1,
1803 LLQErr_NoSuchLLQ
= 4,
1805 LLQErr_UnknownErr
= 6
1808 typedef void (*InternalResponseHndlr
)(mDNS
*const m
, DNSMessage
*msg
, const mDNSu8
*end
, DNSQuestion
*question
, void *internalContext
);
1813 InternalResponseHndlr responseCallback
; // NULL if internal field is false
1814 LLQ_Info
*llq
; // NULL for 1-shot queries
1815 mDNSBool Answered
; // have we received an answer (including NXDOMAIN) for this question?
1816 CacheRecord
*knownAnswers
;
1817 mDNSs32 RestartTime
; // Mark when we restart a suspended query
1819 } uDNS_QuestionInfo
;
1821 // Note: Within an mDNSQuestionCallback mDNS all API calls are legal except mDNS_Init(), mDNS_Close(), mDNS_Execute()
1822 typedef void mDNSQuestionCallback(mDNS
*const m
, DNSQuestion
*question
, const ResourceRecord
*const answer
, mDNSBool AddRecord
);
1823 struct DNSQuestion_struct
1825 // Internal state fields. These are used internally by mDNSCore; the client layer needn't be concerned with them.
1828 mDNSs32 DelayAnswering
; // Set if we want to defer answering this question until the cache settles
1829 mDNSs32 LastQTime
; // Last scheduled transmission of this Q on *all* applicable interfaces
1830 mDNSs32 ThisQInterval
; // LastQTime + ThisQInterval is the next scheduled transmission of this Q
1831 // ThisQInterval > 0 for an active question;
1832 // ThisQInterval = 0 for a suspended question that's still in the list
1833 // ThisQInterval = -1 for a cancelled question that's been removed from the list
1834 mDNSs32 LastAnswerPktNum
; // The sequence number of the last response packet containing an answer to this Q
1835 mDNSu32 RecentAnswerPkts
; // Number of answers since the last time we sent this query
1836 mDNSu32 CurrentAnswers
; // Number of records currently in the cache that answer this question
1837 mDNSu32 LargeAnswers
; // Number of answers with rdata > 1024 bytes
1838 mDNSu32 UniqueAnswers
; // Number of answers received with kDNSClass_UniqueRRSet bit set
1839 DNSQuestion
*DuplicateOf
;
1840 DNSQuestion
*NextInDQList
;
1841 DupSuppressInfo DupSuppress
[DupSuppressInfoSize
];
1842 mDNSInterfaceID SendQNow
; // The interface this query is being sent on right now
1843 mDNSBool SendOnAll
; // Set if we're sending this question on all active interfaces
1844 mDNSu32 RequestUnicast
; // Non-zero if we want to send query with kDNSQClass_UnicastResponse bit set
1845 mDNSs32 LastQTxTime
; // Last time this Q was sent on one (but not necessarily all) interfaces
1846 uDNS_QuestionInfo uDNS_info
;
1848 // Client API fields: The client must set up these fields *before* calling mDNS_StartQuery()
1849 mDNSInterfaceID InterfaceID
; // Non-zero if you want to issue queries only on a single specific IP interface
1850 mDNSAddr Target
; // Non-zero if you want to direct queries to a specific unicast target address
1851 mDNSIPPort TargetPort
; // Must be set if Target is set
1852 mDNSOpaque16 TargetQID
; // Must be set if Target is set
1856 mDNSBool LongLived
; // Set by client for calls to mDNS_StartQuery to indicate LLQs to unicast layer.
1857 mDNSBool ExpectUnique
; // Set by client if it's expecting unique RR(s) for this question, not shared RRs
1858 mDNSBool ForceMCast
; // Set by client to force mDNS query, even for apparently uDNS names
1859 mDNSQuestionCallback
*QuestionCallback
;
1860 void *QuestionContext
;
1865 // Client API fields: The client must set up name and InterfaceID *before* calling mDNS_StartResolveService()
1866 // When the callback is invoked, ip, port, TXTlen and TXTinfo will have been filled in with the results learned from the network.
1868 mDNSInterfaceID InterfaceID
; // ID of the interface the response was received on
1869 mDNSAddr ip
; // Remote (destination) IP address where this service can be accessed
1870 mDNSIPPort port
; // Port where this service can be accessed
1872 mDNSu8 TXTinfo
[2048]; // Additional demultiplexing information (e.g. LPR queue name)
1875 // Note: Within an mDNSServiceInfoQueryCallback mDNS all API calls are legal except mDNS_Init(), mDNS_Close(), mDNS_Execute()
1876 typedef struct ServiceInfoQuery_struct ServiceInfoQuery
;
1877 typedef void mDNSServiceInfoQueryCallback(mDNS
*const m
, ServiceInfoQuery
*query
);
1878 struct ServiceInfoQuery_struct
1880 // Internal state fields. These are used internally by mDNSCore; the client layer needn't be concerned with them.
1881 // No fields need to be set up by the client prior to calling mDNS_StartResolveService();
1882 // all required data is passed as parameters to that function.
1883 // The ServiceInfoQuery structure memory is working storage for mDNSCore to discover the requested information
1884 // and place it in the ServiceInfo structure. After the client has called mDNS_StopResolveService(), it may
1885 // dispose of the ServiceInfoQuery structure while retaining the results in the ServiceInfo structure.
1895 mDNSServiceInfoQueryCallback
*ServiceInfoQueryCallback
;
1896 void *ServiceInfoQueryContext
;
1899 // ***************************************************************************
1901 #pragma mark - NAT Traversal structures and constants
1904 #define NATMAP_INIT_RETRY (mDNSPlatformOneSecond / 4) // start at 250ms w/ exponential decay
1905 #define NATMAP_MAX_RETRY mDNSPlatformOneSecond // back off to once per second
1906 #define NATMAP_MAX_TRIES 3 // for max 3 tries
1907 #define NATMAP_DEFAULT_LEASE (60 * 60) // lease life in seconds
1908 #define NATMAP_VERS 0
1909 #define NATMAP_PORT 5351
1910 #define NATMAP_RESPONSE_MASK 0x80
1914 NATOp_AddrRequest
= 0,
1929 typedef mDNSu16 NATErr_t
;
1934 NATState_Request
= 1,
1935 NATState_Established
= 2,
1936 NATState_Legacy
= 3,
1938 NATState_Refresh
= 5,
1939 NATState_Deleted
= 6
1941 // Note: we have no explicit "cancelled" state, where a service/interface is deregistered while we
1942 // have an outstanding NAT request. This is conveyed by the "reg" pointer being set to NULL
1944 typedef packedstruct
1950 typedef packedstruct
1955 mDNSOpaque32 uptime
;
1959 typedef packedstruct
1963 mDNSOpaque16 unused
;
1967 } NATPortMapRequest
;
1969 typedef packedstruct
1974 mDNSOpaque32 uptime
;
1980 // Pass NULL for pkt on error (including timeout)
1981 typedef mDNSBool (*NATResponseHndlr
)(NATTraversalInfo
*n
, mDNS
*m
, mDNSu8
*pkt
, mDNSu16 len
);
1983 struct NATTraversalInfo_struct
1986 NATResponseHndlr ReceiveResponse
;
1987 union { AuthRecord
*RecordRegistration
; ServiceRecordSet
*ServiceRegistration
; } reg
;
1989 mDNSIPPort PublicPort
;
1990 union { NATAddrRequest AddrReq
; NATPortMapRequest PortReq
; } request
;
1991 mDNSs32 retry
; // absolute time when we retry
1992 mDNSs32 RetryInterval
; // delta between time sent and retry
1995 NATTraversalInfo
*next
;
1998 // ***************************************************************************
2000 #pragma mark - Main mDNS object, used to hold all the mDNS state
2003 typedef void mDNSCallback(mDNS
*const m
, mStatus result
);
2005 #define CACHE_HASH_SLOTS 499
2009 mDNS_KnownBug_PhantomInterfaces
= 1
2015 DNSQuestion
*ActiveQueries
; //!!!KRS this should be a hashtable (hash on messageID)
2016 DNSQuestion
*CurrentQuery
; // pointer to ActiveQueries list being examined in a loop. Functions that remove
2017 // elements from the ActiveQueries list must update this pointer (if non-NULL) as necessary.
2018 //!!!KRS do the same for registration lists
2019 ServiceRecordSet
*ServiceRegistrations
;
2020 AuthRecord
*RecordRegistrations
;
2021 NATTraversalInfo
*NATTraversals
;
2022 mDNSu16 NextMessageID
;
2023 DNSServer
*Servers
; // list of DNS servers
2025 mDNSAddr AdvertisedV4
; // IPv4 address pointed to by hostname
2026 mDNSAddr MappedV4
; // Cache of public address if PrimaryIP is behind a NAT
2027 mDNSAddr AdvertisedV6
; // IPv6 address pointed to by hostname
2028 NATTraversalInfo
*LLQNatInfo
; // Nat port mapping to receive LLQ events
2029 domainname ServiceRegDomain
; // (going away w/ multi-user support)
2030 struct uDNS_AuthInfo
*AuthInfoList
; // list of domains requiring authentication for updates.
2031 uDNS_HostnameInfo
*Hostnames
; // List of registered hostnames + hostname metadata
2032 DNSQuestion ReverseMap
; // Reverse-map query to find static hostname for service target
2033 mDNSBool ReverseMapActive
; // Is above query active?
2034 domainname StaticHostname
; // Current answer to reverse-map query (above)
2035 mDNSBool DelaySRVUpdate
; // Delay SRV target/port update to avoid "flap"
2036 mDNSs32 NextSRVUpdate
; // Time to perform delayed update
2041 // Internal state fields. These hold the main internal state of mDNSCore;
2042 // the client layer needn't be concerned with them.
2043 // No fields need to be set up by the client prior to calling mDNS_Init();
2044 // all required data is passed as parameters to that function.
2046 mDNS_PlatformSupport
*p
; // Pointer to platform-specific data of indeterminite size
2048 mDNSBool CanReceiveUnicastOn5353
;
2049 mDNSBool AdvertiseLocalAddresses
;
2050 mStatus mDNSPlatformStatus
;
2051 mDNSIPPort UnicastPort4
;
2052 mDNSIPPort UnicastPort6
;
2053 mDNSCallback
*MainCallback
;
2056 // For debugging: To catch and report locking failures
2057 mDNSu32 mDNS_busy
; // Incremented between mDNS_Lock/mDNS_Unlock section
2058 mDNSu32 mDNS_reentrancy
; // Incremented when calling a client callback
2059 mDNSu8 mDNS_shutdown
; // Set when we're shutting down, allows us to skip some unnecessary steps
2060 mDNSu8 lock_rrcache
; // For debugging: Set at times when these lists may not be modified
2061 mDNSu8 lock_Questions
;
2062 mDNSu8 lock_Records
;
2063 char MsgBuffer
[80]; // Temp storage used while building error log messages
2065 // Task Scheduling variables
2066 mDNSs32 timenow
; // The time that this particular activation of the mDNS code started
2067 mDNSs32 timenow_last
; // The time the last time we ran
2068 mDNSs32 timenow_adjust
; // Correction applied if we ever discover time went backwards
2069 mDNSs32 NextScheduledEvent
; // Derived from values below
2070 mDNSs32 SuppressSending
; // Don't send *any* packets during this time
2071 mDNSs32 NextCacheCheck
; // Next time to refresh cache record before it expires
2072 mDNSs32 NextScheduledQuery
; // Next time to send query in its exponential backoff sequence
2073 mDNSs32 NextScheduledProbe
; // Next time to probe for new authoritative record
2074 mDNSs32 NextScheduledResponse
; // Next time to send authoritative record(s) in responses
2075 mDNSs32 ExpectUnicastResponse
; // Set when we send a query with the kDNSQClass_UnicastResponse bit set
2076 mDNSs32 RandomQueryDelay
; // For de-synchronization of query packets on the wire
2077 mDNSs32 PktNum
; // Unique sequence number assigned to each received packet
2078 mDNSBool SendDeregistrations
; // Set if we need to send deregistrations (immediately)
2079 mDNSBool SendImmediateAnswers
; // Set if we need to send answers (immediately -- or as soon as SuppressSending clears)
2080 mDNSBool SleepState
; // Set if we're sleeping (send no more packets)
2082 // These fields only required for mDNS Searcher...
2083 DNSQuestion
*Questions
; // List of all registered questions, active and inactive
2084 DNSQuestion
*NewQuestions
; // Fresh questions not yet answered from cache
2085 DNSQuestion
*CurrentQuestion
; // Next question about to be examined in AnswerLocalQuestions()
2086 DNSQuestion
*LocalOnlyQuestions
; // Questions with InterfaceID set to mDNSInterface_LocalOnly
2087 DNSQuestion
*NewLocalOnlyQuestions
; // Fresh local-only questions not yet answered
2088 mDNSu32 rrcache_size
; // Total number of available cache entries
2089 mDNSu32 rrcache_totalused
; // Number of cache entries currently occupied
2090 mDNSu32 rrcache_active
; // Number of cache entries currently occupied by records that answer active questions
2091 mDNSu32 rrcache_report
;
2092 CacheEntity
*rrcache_free
;
2093 CacheGroup
*rrcache_hash
[CACHE_HASH_SLOTS
];
2095 // Fields below only required for mDNS Responder...
2096 domainlabel nicelabel
; // Rich text label encoded using canonically precomposed UTF-8
2097 domainlabel hostlabel
; // Conforms to RFC 1034 "letter-digit-hyphen" ARPANET host name rules
2098 domainname MulticastHostname
; // Fully Qualified "dot-local" Host Name, e.g. "Foo.local."
2099 UTF8str255 HIHardware
;
2100 UTF8str255 HISoftware
;
2101 AuthRecord
*ResourceRecords
;
2102 AuthRecord
*DuplicateRecords
; // Records currently 'on hold' because they are duplicates of existing records
2103 AuthRecord
*NewLocalRecords
; // Fresh local-only records not yet delivered to local-only questions
2104 AuthRecord
*CurrentRecord
; // Next AuthRecord about to be examined
2105 NetworkInterfaceInfo
*HostInterfaces
;
2106 mDNSs32 ProbeFailTime
;
2107 mDNSu32 NumFailedProbes
;
2108 mDNSs32 SuppressProbes
;
2110 // unicast-specific data
2111 uDNS_GlobalInfo uDNS_info
;
2113 // Fixed storage, to avoid creating large objects on the stack
2114 DNSMessage imsg
; // Incoming message received from wire
2115 DNSMessage omsg
; // Outgoing message we're building
2116 LargeCacheRecord rec
; // Resource Record extracted from received message
2119 #define FORALL_CACHERECORDS(SLOT,CG,CR) \
2120 for ((SLOT) = 0; (SLOT) < CACHE_HASH_SLOTS; (SLOT)++) \
2121 for((CG)=m->rrcache_hash[(SLOT)]; (CG); (CG)=(CG)->next) \
2122 for ((CR) = (CG)->members; (CR); (CR)=(CR)->next)
2124 // ***************************************************************************
2126 #pragma mark - Useful Static Constants
2129 extern const mDNSIPPort zeroIPPort
;
2130 extern const mDNSv4Addr zerov4Addr
;
2131 extern const mDNSv6Addr zerov6Addr
;
2132 extern const mDNSEthAddr zeroEthAddr
;
2133 extern const mDNSv4Addr onesIPv4Addr
;
2134 extern const mDNSv6Addr onesIPv6Addr
;
2135 extern const mDNSAddr zeroAddr
;
2137 extern const mDNSInterfaceID mDNSInterface_Any
; // Zero
2138 extern const mDNSInterfaceID mDNSInterface_LocalOnly
; // Special value
2140 extern const mDNSIPPort UnicastDNSPort
;
2141 extern const mDNSIPPort MulticastDNSPort
;
2142 extern const mDNSv4Addr AllDNSAdminGroup
;
2143 extern const mDNSv4Addr AllDNSLinkGroupv4
;
2144 extern const mDNSv6Addr AllDNSLinkGroupv6
;
2145 extern const mDNSAddr AllDNSLinkGroup_v4
;
2146 extern const mDNSAddr AllDNSLinkGroup_v6
;
2148 extern const mDNSOpaque16 zeroID
;
2149 extern const mDNSOpaque16 QueryFlags
;
2150 extern const mDNSOpaque16 ResponseFlags
;
2151 extern const mDNSOpaque16 UpdateReqFlags
;
2152 extern const mDNSOpaque16 UpdateRespFlags
;
2154 #define localdomain (*(const domainname *)"\x5local")
2155 #define LocalReverseMapomain (*(const domainname *)"\x3" "254" "\x3" "169" "\x7" "in-addr" "\x4" "arpa")
2157 // ***************************************************************************
2159 #pragma mark - Inline functions
2162 #if (defined(_MSC_VER))
2163 #define mDNSinline static __inline
2164 #elif ((__GNUC__ > 2) || ((__GNUC__ == 2) && (__GNUC_MINOR__ >= 9)))
2165 #define mDNSinline static inline
2168 // If we're not doing inline functions, then this header needs to have the extern declarations
2169 #if !defined(mDNSinline)
2170 extern mDNSs32
NonZeroTime(mDNSs32 t
);
2171 extern mDNSu16
mDNSVal16(mDNSOpaque16 x
);
2172 extern mDNSu32
mDNSVal32(mDNSOpaque32 x
);
2173 extern mDNSOpaque16
mDNSOpaque16fromIntVal(mDNSu16 v
);
2174 extern mDNSOpaque32
mDNSOpaque32fromIntVal(mDNSu32 v
);
2177 // If we're compiling the particular C file that instantiates our inlines, then we
2178 // define "mDNSinline" (to empty string) so that we generate code in the following section
2179 #if (!defined(mDNSinline) && mDNS_InstantiateInlines)
2185 mDNSinline mDNSs32
NonZeroTime(mDNSs32 t
) { if (t
) return(t
); else return(1); }
2187 mDNSinline mDNSu16
mDNSVal16(mDNSOpaque16 x
) { return((mDNSu16
)((mDNSu16
)x
.b
[0] << 8 | (mDNSu16
)x
.b
[1])); }
2188 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])); }
2190 mDNSinline mDNSOpaque16
mDNSOpaque16fromIntVal(mDNSu16 v
)
2193 x
.b
[0] = (mDNSu8
)(v
>> 8);
2194 x
.b
[1] = (mDNSu8
)(v
& 0xFF);
2198 mDNSinline mDNSOpaque32
mDNSOpaque32fromIntVal(mDNSu32 v
)
2201 x
.b
[0] = (mDNSu8
) (v
>> 24) ;
2202 x
.b
[1] = (mDNSu8
)((v
>> 16) & 0xFF);
2203 x
.b
[2] = (mDNSu8
)((v
>> 8 ) & 0xFF);
2204 x
.b
[3] = (mDNSu8
)((v
) & 0xFF);
2210 // ***************************************************************************
2212 #pragma mark - Main Client Functions
2215 // Every client should call mDNS_Init, passing in storage for the mDNS object and the mDNS_PlatformSupport object.
2217 // Clients that are only advertising services should use mDNS_Init_NoCache and mDNS_Init_ZeroCacheSize.
2218 // Clients that plan to perform queries (mDNS_StartQuery, mDNS_StartBrowse, mDNS_StartResolveService, etc.)
2219 // need to provide storage for the resource record cache, or the query calls will return 'mStatus_NoCache'.
2220 // The rrcachestorage parameter is the address of memory for the resource record cache, and
2221 // the rrcachesize parameter is the number of entries in the CacheRecord array passed in.
2222 // (i.e. the size of the cache memory needs to be sizeof(CacheRecord) * rrcachesize).
2223 // OS X 10.3 Panther uses an initial cache size of 64 entries, and then mDNSCore sends an
2224 // mStatus_GrowCache message if it needs more.
2226 // Most clients should use mDNS_Init_AdvertiseLocalAddresses. This causes mDNSCore to automatically
2227 // create the correct address records for all the hosts interfaces. If you plan to advertise
2228 // services being offered by the local machine, this is almost always what you want.
2229 // There are two cases where you might use mDNS_Init_DontAdvertiseLocalAddresses:
2230 // 1. A client-only device, that browses for services but doesn't advertise any of its own.
2231 // 2. A proxy-registration service, that advertises services being offered by other machines, and takes
2232 // the appropriate steps to manually create the correct address records for those other machines.
2233 // In principle, a proxy-like registration service could manually create address records for its own machine too,
2234 // but this would be pointless extra effort when using mDNS_Init_AdvertiseLocalAddresses does that for you.
2236 // When mDNS has finished setting up the client's callback is called
2237 // A client can also spin and poll the mDNSPlatformStatus field to see when it changes from mStatus_Waiting to mStatus_NoError
2239 // Call mDNS_Close to tidy up before exiting
2241 // Call mDNS_Register with a completed AuthRecord object to register a resource record
2242 // If the resource record type is kDNSRecordTypeUnique (or kDNSknownunique) then if a conflicting resource record is discovered,
2243 // the resource record's mDNSRecordCallback will be called with error code mStatus_NameConflict. The callback should deregister
2244 // the record, and may then try registering the record again after picking a new name (e.g. by automatically appending a number).
2245 // Following deregistration, the RecordCallback will be called with result mStatus_MemFree to signal that it is safe to deallocate
2246 // the record's storage (memory must be freed asynchronously to allow for goodbye packets and dynamic update deregistration).
2248 // Call mDNS_StartQuery to initiate a query. mDNS will proceed to issue Multicast DNS query packets, and any time a response
2249 // is received containing a record which matches the question, the DNSQuestion's mDNSAnswerCallback function will be called
2250 // Call mDNS_StopQuery when no more answers are required
2252 // Care should be taken on multi-threaded or interrupt-driven environments.
2253 // The main mDNS routines call mDNSPlatformLock() on entry and mDNSPlatformUnlock() on exit;
2254 // each platform layer needs to implement these appropriately for its respective platform.
2255 // For example, if the support code on a particular platform implements timer callbacks at interrupt time, then
2256 // mDNSPlatformLock/Unlock need to disable interrupts or do similar concurrency control to ensure that the mDNS
2257 // code is not entered by an interrupt-time timer callback while in the middle of processing a client call.
2259 extern mStatus
mDNS_Init (mDNS
*const m
, mDNS_PlatformSupport
*const p
,
2260 CacheEntity
*rrcachestorage
, mDNSu32 rrcachesize
,
2261 mDNSBool AdvertiseLocalAddresses
,
2262 mDNSCallback
*Callback
, void *Context
);
2263 // See notes above on use of NoCache/ZeroCacheSize
2264 #define mDNS_Init_NoCache mDNSNULL
2265 #define mDNS_Init_ZeroCacheSize 0
2266 // See notes above on use of Advertise/DontAdvertiseLocalAddresses
2267 #define mDNS_Init_AdvertiseLocalAddresses mDNStrue
2268 #define mDNS_Init_DontAdvertiseLocalAddresses mDNSfalse
2269 #define mDNS_Init_NoInitCallback mDNSNULL
2270 #define mDNS_Init_NoInitCallbackContext mDNSNULL
2272 extern void mDNS_GrowCache (mDNS
*const m
, CacheEntity
*storage
, mDNSu32 numrecords
);
2273 extern void mDNS_Close (mDNS
*const m
);
2274 extern mDNSs32
mDNS_Execute (mDNS
*const m
);
2276 extern mStatus
mDNS_Register (mDNS
*const m
, AuthRecord
*const rr
);
2277 extern mStatus
mDNS_Update (mDNS
*const m
, AuthRecord
*const rr
, mDNSu32 newttl
,
2278 const mDNSu16 newrdlength
, RData
*const newrdata
, mDNSRecordUpdateCallback
*Callback
);
2279 extern mStatus
mDNS_Deregister(mDNS
*const m
, AuthRecord
*const rr
);
2281 extern mStatus
mDNS_StartQuery(mDNS
*const m
, DNSQuestion
*const question
);
2282 extern mStatus
mDNS_StopQuery (mDNS
*const m
, DNSQuestion
*const question
);
2283 extern mStatus
mDNS_Reconfirm (mDNS
*const m
, CacheRecord
*const cacherr
);
2284 extern mStatus
mDNS_ReconfirmByValue(mDNS
*const m
, ResourceRecord
*const rr
);
2285 extern mDNSs32
mDNS_TimeNow(const mDNS
*const m
);
2287 // ***************************************************************************
2289 #pragma mark - Platform support functions that are accessible to the client layer too
2292 extern mDNSs32 mDNSPlatformOneSecond
;
2294 // ***************************************************************************
2296 #pragma mark - General utility and helper functions
2299 // mDNS_RegisterService is a single call to register the set of resource records associated with a given named service.
2301 // mDNS_StartResolveService is single call which is equivalent to multiple calls to mDNS_StartQuery,
2302 // to find the IP address, port number, and demultiplexing information for a given named service.
2303 // As with mDNS_StartQuery, it executes asynchronously, and calls the ServiceInfoQueryCallback when the answer is
2304 // found. After the service is resolved, the client should call mDNS_StopResolveService to complete the transaction.
2305 // The client can also call mDNS_StopResolveService at any time to abort the transaction.
2307 // mDNS_AddRecordToService adds an additional record to a Service Record Set. This record may be deregistered
2308 // via mDNS_RemoveRecordFromService, or by deregistering the service. mDNS_RemoveRecordFromService is passed a
2309 // callback to free the memory associated with the extra RR when it is safe to do so. The ExtraResourceRecord
2310 // object can be found in the record's context pointer.
2312 // mDNS_GetBrowseDomains is a special case of the mDNS_StartQuery call, where the resulting answers
2313 // are a list of PTR records indicating (in the rdata) domains that are recommended for browsing.
2314 // After getting the list of domains to browse, call mDNS_StopQuery to end the search.
2315 // mDNS_GetDefaultBrowseDomain returns the name of the domain that should be highlighted by default.
2317 // mDNS_GetRegistrationDomains and mDNS_GetDefaultRegistrationDomain are the equivalent calls to get the list
2318 // of one or more domains that should be offered to the user as choices for where they may register their service,
2319 // and the default domain in which to register in the case where the user has made no selection.
2321 extern void mDNS_SetupResourceRecord(AuthRecord
*rr
, RData
*RDataStorage
, mDNSInterfaceID InterfaceID
,
2322 mDNSu16 rrtype
, mDNSu32 ttl
, mDNSu8 RecordType
, mDNSRecordCallback Callback
, void *Context
);
2324 extern mStatus
mDNS_RegisterService (mDNS
*const m
, ServiceRecordSet
*sr
,
2325 const domainlabel
*const name
, const domainname
*const type
, const domainname
*const domain
,
2326 const domainname
*const host
, mDNSIPPort port
, const mDNSu8 txtinfo
[], mDNSu16 txtlen
,
2327 AuthRecord
*SubTypes
, mDNSu32 NumSubTypes
,
2328 const mDNSInterfaceID InterfaceID
, mDNSServiceCallback Callback
, void *Context
);
2329 extern mStatus
mDNS_AddRecordToService(mDNS
*const m
, ServiceRecordSet
*sr
, ExtraResourceRecord
*extra
, RData
*rdata
, mDNSu32 ttl
);
2330 extern mStatus
mDNS_RemoveRecordFromService(mDNS
*const m
, ServiceRecordSet
*sr
, ExtraResourceRecord
*extra
, mDNSRecordCallback MemFreeCallback
, void *Context
);
2331 extern mStatus
mDNS_RenameAndReregisterService(mDNS
*const m
, ServiceRecordSet
*const sr
, const domainlabel
*newname
);
2332 extern mStatus
mDNS_DeregisterService(mDNS
*const m
, ServiceRecordSet
*sr
);
2334 extern mStatus
mDNS_RegisterNoSuchService(mDNS
*const m
, AuthRecord
*const rr
,
2335 const domainlabel
*const name
, const domainname
*const type
, const domainname
*const domain
,
2336 const domainname
*const host
,
2337 const mDNSInterfaceID InterfaceID
, mDNSRecordCallback Callback
, void *Context
);
2338 #define mDNS_DeregisterNoSuchService mDNS_Deregister
2340 extern mStatus
mDNS_StartBrowse(mDNS
*const m
, DNSQuestion
*const question
,
2341 const domainname
*const srv
, const domainname
*const domain
,
2342 const mDNSInterfaceID InterfaceID
, mDNSBool ForceMCast
, mDNSQuestionCallback
*Callback
, void *Context
);
2343 #define mDNS_StopBrowse mDNS_StopQuery
2345 extern mStatus
mDNS_StartResolveService(mDNS
*const m
, ServiceInfoQuery
*query
, ServiceInfo
*info
, mDNSServiceInfoQueryCallback
*Callback
, void *Context
);
2346 extern void mDNS_StopResolveService (mDNS
*const m
, ServiceInfoQuery
*query
);
2350 mDNS_DomainTypeBrowse
= 0,
2351 mDNS_DomainTypeBrowseDefault
= 1,
2352 mDNS_DomainTypeBrowseLegacy
= 2,
2353 mDNS_DomainTypeRegistration
= 3,
2354 mDNS_DomainTypeRegistrationDefault
= 4,
2356 mDNS_DomainTypeMax
= 4
2359 extern const char *const mDNS_DomainTypeNames
[];
2361 extern mStatus
mDNS_GetDomains(mDNS
*const m
, DNSQuestion
*const question
, mDNS_DomainType DomainType
, const domainname
*dom
,
2362 const mDNSInterfaceID InterfaceID
, mDNSQuestionCallback
*Callback
, void *Context
);
2363 #define mDNS_StopGetDomains mDNS_StopQuery
2364 extern mStatus
mDNS_AdvertiseDomains(mDNS
*const m
, AuthRecord
*rr
, mDNS_DomainType DomainType
, const mDNSInterfaceID InterfaceID
, char *domname
);
2365 #define mDNS_StopAdvertiseDomains mDNS_Deregister
2367 // ***************************************************************************
2369 #pragma mark - DNS name utility functions
2372 // In order to expose the full capabilities of the DNS protocol (which allows any arbitrary eight-bit values
2373 // in domain name labels, including unlikely characters like ascii nulls and even dots) all the mDNS APIs
2374 // work with DNS's native length-prefixed strings. For convenience in C, the following utility functions
2375 // are provided for converting between C's null-terminated strings and DNS's length-prefixed strings.
2378 // A simple C structure assignment of a domainname can cause a protection fault by accessing unmapped memory,
2379 // because that object is defined to be 256 bytes long, but not all domainname objects are truly the full size.
2380 // This macro uses mDNSPlatformMemCopy() to make sure it only touches the actual bytes that are valid.
2381 #define AssignDomainName(DST, SRC) mDNSPlatformMemCopy((SRC)->c, (DST)->c, DomainNameLength((SRC)))
2383 // Comparison functions
2384 extern mDNSBool
SameDomainLabel(const mDNSu8
*a
, const mDNSu8
*b
);
2385 extern mDNSBool
SameDomainName(const domainname
*const d1
, const domainname
*const d2
);
2386 extern mDNSBool
IsLocalDomain(const domainname
*d
); // returns true for domains that by default should be looked up using link-local multicast
2388 // Get total length of domain name, in native DNS format, including terminal root label
2389 // (e.g. length of "com." is 5 (length byte, three data bytes, final zero)
2390 extern mDNSu16
DomainNameLength(const domainname
*const name
);
2392 // Append functions to append one or more labels to an existing native format domain name:
2393 // AppendLiteralLabelString adds a single label from a literal C string, with no escape character interpretation.
2394 // AppendDNSNameString adds zero or more labels from a C string using conventional DNS dots-and-escaping interpretation
2395 // AppendDomainLabel adds a single label from a native format domainlabel
2396 // AppendDomainName adds zero or more labels from a native format domainname
2397 extern mDNSu8
*AppendLiteralLabelString(domainname
*const name
, const char *cstr
);
2398 extern mDNSu8
*AppendDNSNameString (domainname
*const name
, const char *cstr
);
2399 extern mDNSu8
*AppendDomainLabel (domainname
*const name
, const domainlabel
*const label
);
2400 extern mDNSu8
*AppendDomainName (domainname
*const name
, const domainname
*const append
);
2402 // Convert from null-terminated string to native DNS format:
2403 // The DomainLabel form makes a single label from a literal C string, with no escape character interpretation.
2404 // The DomainName form makes native format domain name from a C string using conventional DNS interpretation:
2405 // dots separate labels, and within each label, '\.' represents a literal dot, '\\' represents a literal
2406 // backslash and backslash with three decimal digits (e.g. \000) represents an arbitrary byte value.
2407 extern mDNSBool
MakeDomainLabelFromLiteralString(domainlabel
*const label
, const char *cstr
);
2408 extern mDNSu8
*MakeDomainNameFromDNSNameString (domainname
*const name
, const char *cstr
);
2410 // Convert native format domainlabel or domainname back to C string format
2412 // When using ConvertDomainLabelToCString, the target buffer must be MAX_ESCAPED_DOMAIN_LABEL (254) bytes long
2413 // to guarantee there will be no buffer overrun. It is only safe to use a buffer shorter than this in rare cases
2414 // where the label is known to be constrained somehow (for example, if the label is known to be either "_tcp" or "_udp").
2415 // Similarly, when using ConvertDomainNameToCString, the target buffer must be MAX_ESCAPED_DOMAIN_NAME (1005) bytes long.
2416 // See definitions of MAX_ESCAPED_DOMAIN_LABEL and MAX_ESCAPED_DOMAIN_NAME for more detailed explanation.
2417 extern char *ConvertDomainLabelToCString_withescape(const domainlabel
*const name
, char *cstr
, char esc
);
2418 #define ConvertDomainLabelToCString_unescaped(D,C) ConvertDomainLabelToCString_withescape((D), (C), 0)
2419 #define ConvertDomainLabelToCString(D,C) ConvertDomainLabelToCString_withescape((D), (C), '\\')
2420 extern char *ConvertDomainNameToCString_withescape(const domainname
*const name
, char *cstr
, char esc
);
2421 #define ConvertDomainNameToCString_unescaped(D,C) ConvertDomainNameToCString_withescape((D), (C), 0)
2422 #define ConvertDomainNameToCString(D,C) ConvertDomainNameToCString_withescape((D), (C), '\\')
2424 extern void ConvertUTF8PstringToRFC1034HostLabel(const mDNSu8 UTF8Name
[], domainlabel
*const hostlabel
);
2426 extern mDNSu8
*ConstructServiceName(domainname
*const fqdn
, const domainlabel
*name
, const domainname
*type
, const domainname
*const domain
);
2427 extern mDNSBool
DeconstructServiceName(const domainname
*const fqdn
, domainlabel
*const name
, domainname
*const type
, domainname
*const domain
);
2429 // Note: Some old functions have been replaced by more sensibly-named versions.
2430 // You can uncomment the hash-defines below if you don't want to have to change your source code right away.
2431 // When updating your code, note that (unlike the old versions) *all* the new routines take the target object
2432 // as their first parameter.
2433 //#define ConvertCStringToDomainName(SRC,DST) MakeDomainNameFromDNSNameString((DST),(SRC))
2434 //#define ConvertCStringToDomainLabel(SRC,DST) MakeDomainLabelFromLiteralString((DST),(SRC))
2435 //#define AppendStringLabelToName(DST,SRC) AppendLiteralLabelString((DST),(SRC))
2436 //#define AppendStringNameToName(DST,SRC) AppendDNSNameString((DST),(SRC))
2437 //#define AppendDomainLabelToName(DST,SRC) AppendDomainLabel((DST),(SRC))
2438 //#define AppendDomainNameToName(DST,SRC) AppendDomainName((DST),(SRC))
2440 // ***************************************************************************
2442 #pragma mark - Other utility functions and macros
2445 extern mDNSu32
mDNS_vsnprintf(char *sbuffer
, mDNSu32 buflen
, const char *fmt
, va_list arg
);
2446 extern mDNSu32
mDNS_snprintf(char *sbuffer
, mDNSu32 buflen
, const char *fmt
, ...) IS_A_PRINTF_STYLE_FUNCTION(3,4);
2447 extern mDNSu32
NumCacheRecordsForInterfaceID(const mDNS
*const m
, mDNSInterfaceID id
);
2448 extern char *DNSTypeName(mDNSu16 rrtype
);
2449 extern char *GetRRDisplayString_rdb(const ResourceRecord
*rr
, RDataBody
*rd
, char *buffer
);
2450 #define RRDisplayString(m, rr) GetRRDisplayString_rdb(rr, &(rr)->rdata->u, (m)->MsgBuffer)
2451 #define ARDisplayString(m, rr) GetRRDisplayString_rdb(&(rr)->resrec, &(rr)->resrec.rdata->u, (m)->MsgBuffer)
2452 #define CRDisplayString(m, rr) GetRRDisplayString_rdb(&(rr)->resrec, &(rr)->resrec.rdata->u, (m)->MsgBuffer)
2453 extern mDNSBool
mDNSSameAddress(const mDNSAddr
*ip1
, const mDNSAddr
*ip2
);
2454 extern void IncrementLabelSuffix(domainlabel
*name
, mDNSBool RichText
);
2455 extern mDNSBool
IsPrivateV4Addr(mDNSAddr
*addr
); // returns true for RFC1918 private addresses
2457 #define mDNSSameIPv4Address(A,B) ((A).NotAnInteger == (B).NotAnInteger)
2458 #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])
2459 #define mDNSSameEthAddress(A,B) ((A)->w[0] == (B)->w[0] && (A)->w[1] == (B)->w[1] && (A)->w[2] == (B)->w[2])
2461 #define mDNSIPv4AddressIsZero(A) mDNSSameIPv4Address((A), zerov4Addr)
2462 #define mDNSIPv6AddressIsZero(A) mDNSSameIPv6Address((A), zerov6Addr)
2464 #define mDNSIPv4AddressIsOnes(A) mDNSSameIPv4Address((A), onesIPv4Addr)
2465 #define mDNSIPv6AddressIsOnes(A) mDNSSameIPv6Address((A), onesIPv6Addr)
2467 #define mDNSAddressIsAllDNSLinkGroup(X) ( \
2468 ((X)->type == mDNSAddrType_IPv4 && mDNSSameIPv4Address((X)->ip.v4, AllDNSLinkGroupv4)) || \
2469 ((X)->type == mDNSAddrType_IPv6 && mDNSSameIPv6Address((X)->ip.v6, AllDNSLinkGroupv6)) )
2471 #define mDNSAddressIsZero(X) ( \
2472 ((X)->type == mDNSAddrType_IPv4 && mDNSIPv4AddressIsZero((X)->ip.v4)) || \
2473 ((X)->type == mDNSAddrType_IPv6 && mDNSIPv6AddressIsZero((X)->ip.v6)) )
2475 #define mDNSAddressIsValidNonZero(X) ( \
2476 ((X)->type == mDNSAddrType_IPv4 && !mDNSIPv4AddressIsZero((X)->ip.v4)) || \
2477 ((X)->type == mDNSAddrType_IPv6 && !mDNSIPv6AddressIsZero((X)->ip.v6)) )
2479 #define mDNSAddressIsOnes(X) ( \
2480 ((X)->type == mDNSAddrType_IPv4 && mDNSIPv4AddressIsOnes((X)->ip.v4)) || \
2481 ((X)->type == mDNSAddrType_IPv6 && mDNSIPv6AddressIsOnes((X)->ip.v6)) )
2483 #define mDNSAddressIsValid(X) ( \
2484 ((X)->type == mDNSAddrType_IPv4) ? !(mDNSIPv4AddressIsZero((X)->ip.v4) || mDNSIPv4AddressIsOnes((X)->ip.v4)) : \
2485 ((X)->type == mDNSAddrType_IPv6) ? !(mDNSIPv6AddressIsZero((X)->ip.v6) || mDNSIPv6AddressIsOnes((X)->ip.v6)) : mDNSfalse)
2488 // ***************************************************************************
2490 #pragma mark - Authentication Support
2494 #define HMAC_IPAD 0x36
2495 #define HMAC_OPAD 0x5c
2498 // padded keys for inned/outer hash rounds
2501 mDNSu8 ipad
[HMAC_LEN
];
2502 mDNSu8 opad
[HMAC_LEN
];
2505 // Internal data structure to maintain authentication information for an update domain
2506 typedef struct uDNS_AuthInfo
2511 struct uDNS_AuthInfo
*next
;
2514 // Unicast DNS and Dynamic Update specific Client Calls
2516 // mDNS_SetSecretForZone tells the core to authenticate (via TSIG with an HMAC_MD5 hash of the shared secret)
2517 // when dynamically updating a given zone (and its subdomains). The key used in authentication must be in
2518 // domain name format. The shared secret must be a null-terminated base64 encoded string. A minimum size of
2519 // 16 bytes (128 bits) is recommended for an MD5 hash as per RFC 2485.
2520 // Calling this routine multiple times for a zone replaces previously entered values. Call with a NULL key
2521 // to dissable authentication for the zone.
2523 extern mStatus
mDNS_SetSecretForZone(mDNS
*m
, const domainname
*zone
, const domainname
*key
, const char *sharedSecret
);
2525 // Hostname/Unicast Interface Configuration
2527 // All hostnames advertised point to one IPv4 address and/or one IPv6 address, set via SetPrimaryInterfaceInfo. Invoking this routine
2528 // updates all existing hostnames to point to the new address.
2530 // A hostname is added via AddDynDNSHostName, which points to the primary interface's v4 and/or v6 addresss
2532 // The status callback is invoked to convey success or failure codes - the callback should not modify the AuthRecord or free memory.
2533 // Added hostnames may be removed (deregistered) via mDNS_RemoveDynDNSHostName.
2535 // Host domains added prior to specification of the primary interface address and computer name will be deferred until
2536 // these values are initialized.
2538 // When routable V4 interfaces are added or removed, mDNS_UpdateLLQs should be called to re-estabish LLQs in case the
2539 // destination address for events (i.e. the route) has changed. For performance reasons, the caller is responsible for
2540 // batching changes, e.g. calling the routine only once if multiple interfaces are simultanously removed or added.
2542 // DNS servers used to resolve unicast queries are specified by mDNS_AddDNSServer, and may later be removed via mDNS_DeleteDNSServers.
2543 // For "split" DNS configurations, in which queries for different domains are sent to different servers (e.g. VPN and external),
2544 // a domain may be associated with a DNS server. For standard configurations, specify the root label (".") or NULL.
2546 extern void mDNS_AddDynDNSHostName(mDNS
*m
, const domainname
*fqdn
, mDNSRecordCallback
*StatusCallback
, const void *StatusContext
);
2547 extern void mDNS_RemoveDynDNSHostName(mDNS
*m
, const domainname
*fqdn
);
2548 extern void mDNS_SetPrimaryInterfaceInfo(mDNS
*m
, const mDNSAddr
*v4addr
, const mDNSAddr
*v6addr
, const mDNSAddr
*router
);
2549 extern void mDNS_UpdateLLQs(mDNS
*m
);
2550 extern void mDNS_AddDNSServer(mDNS
*const m
, const mDNSAddr
*dnsAddr
, const domainname
*domain
);
2551 extern void mDNS_DeleteDNSServers(mDNS
*const m
);
2553 // Routines called by the core, exported by DNSDigest.c
2555 // Convert a base64 encoded key into a binary byte stream
2556 extern mDNSs32
DNSDigest_Base64ToBin(const char *src
, mDNSu8
*target
, mDNSu32 targsize
);
2558 // Convert an arbitrary binary key (of any length) into an HMAC key (stored in AuthInfo struct)
2559 extern void DNSDigest_ConstructHMACKey(uDNS_AuthInfo
*info
, const mDNSu8
*key
, mDNSu32 len
);
2561 // sign a DNS message. The message must be compete, with all values in network byte order. end points to the end
2562 // of the message, and is modified by this routine. numAdditionals is a pointer to the number of additional
2563 // records in HOST byte order, which is incremented upon successful completion of this routine. The function returns
2564 // the new end pointer on success, and NULL on failure.
2565 extern mDNSu8
*DNSDigest_SignMessage(DNSMessage
*msg
, mDNSu8
**end
, mDNSu16
*numAdditionals
, uDNS_AuthInfo
*info
);
2567 // ***************************************************************************
2569 #pragma mark - PlatformSupport interface
2572 // This section defines the interface to the Platform Support layer.
2573 // Normal client code should not use any of types defined here, or directly call any of the functions defined here.
2574 // The definitions are placed here because sometimes clients do use these calls indirectly, via other supported client operations.
2575 // For example, AssignDomainName is a macro defined using mDNSPlatformMemCopy()
2577 // Every platform support module must provide the following functions.
2578 // mDNSPlatformInit() typically opens a communication endpoint, and starts listening for mDNS packets.
2579 // When Setup is complete, the platform support layer calls mDNSCoreInitComplete().
2580 // mDNSPlatformSendUDP() sends one UDP packet
2581 // When a packet is received, the PlatformSupport code calls mDNSCoreReceive()
2582 // mDNSPlatformClose() tidies up on exit
2584 // Note: mDNSPlatformMemAllocate/mDNSPlatformMemFree are only required for handling oversized resource records and unicast DNS.
2585 // If your target platform has a well-defined specialized application, and you know that all the records it uses
2586 // are InlineCacheRDSize or less, then you can just make a simple mDNSPlatformMemAllocate() stub that always returns
2587 // NULL. InlineCacheRDSize is a compile-time constant, which is set by default to 64. If you need to handle records
2588 // a little larger than this and you don't want to have to implement run-time allocation and freeing, then you
2589 // can raise the value of this constant to a suitable value (at the expense of increased memory usage).
2591 // USE CAUTION WHEN CALLING mDNSPlatformRawTime: The m->timenow_adjust correction factor needs to be added
2592 // Generally speaking:
2593 // Code that's protected by the main mDNS lock should just use the m->timenow value
2594 // Code outside the main mDNS lock should use mDNS_TimeNow(m) to get properly adjusted time
2596 // mDNSPlatformUTC returns the time, in seconds, since Jan 1st 1970 UTC and is required for generating TSIG records
2598 extern mStatus
mDNSPlatformInit (mDNS
*const m
);
2599 extern void mDNSPlatformClose (mDNS
*const m
);
2600 extern mStatus
mDNSPlatformSendUDP(const mDNS
*const m
, const void *const msg
, const mDNSu8
*const end
,
2601 mDNSInterfaceID InterfaceID
, const mDNSAddr
*dst
, mDNSIPPort dstport
);
2603 extern void mDNSPlatformLock (const mDNS
*const m
);
2604 extern void mDNSPlatformUnlock (const mDNS
*const m
);
2606 extern void mDNSPlatformStrCopy (const void *src
, void *dst
);
2607 extern mDNSu32
mDNSPlatformStrLen (const void *src
);
2608 extern void mDNSPlatformMemCopy (const void *src
, void *dst
, mDNSu32 len
);
2609 extern mDNSBool
mDNSPlatformMemSame (const void *src
, const void *dst
, mDNSu32 len
);
2610 extern void mDNSPlatformMemZero ( void *dst
, mDNSu32 len
);
2611 extern void * mDNSPlatformMemAllocate (mDNSu32 len
);
2612 extern void mDNSPlatformMemFree (void *mem
);
2613 extern mDNSu32
mDNSPlatformRandomSeed (void);
2614 extern mStatus
mDNSPlatformTimeInit (void);
2615 extern mDNSs32
mDNSPlatformRawTime (void);
2616 extern mDNSs32
mDNSPlatformUTC (void);
2618 // Platform support modules should provide the following functions to map between opaque interface IDs
2619 // and interface indexes in order to support the DNS-SD API. If your target platform does not support
2620 // multiple interfaces and/or does not support the DNS-SD API, these functions can be empty.
2621 extern mDNSInterfaceID
mDNSPlatformInterfaceIDfromInterfaceIndex(const mDNS
*const m
, mDNSu32 index
);
2622 extern mDNSu32
mDNSPlatformInterfaceIndexfromInterfaceID(const mDNS
*const m
, mDNSInterfaceID id
);
2624 // Every platform support module must provide the following functions if it is to support unicast DNS
2625 // and Dynamic Update.
2626 // All TCP socket operations implemented by the platform layer MUST NOT BLOCK.
2627 // mDNSPlatformTCPConnect initiates a TCP connection with a peer, adding the socket descriptor to the
2628 // main event loop. The return value indicates whether the connection succeeded, failed, or is pending
2629 // (i.e. the call would block.) On return, the descriptor parameter is set to point to the connected socket.
2630 // The TCPConnectionCallback is subsequently invoked when the connection
2631 // completes (in which case the ConnectionEstablished parameter is true), or data is available for
2632 // reading on the socket (indicated by the ConnectionEstablished parameter being false.) If the connection
2633 // asynchronously fails, the TCPConnectionCallback should be invoked as usual, with the error being
2634 // returned in subsequent calls to PlatformReadTCP or PlatformWriteTCP. (This allows for platforms
2635 // with limited asynchronous error detection capabilities.) PlatformReadTCP and PlatformWriteTCP must
2636 // return the number of bytes read/written, 0 if the call would block, and -1 if an error.
2637 // PlatformTCPCloseConnection must close the connection to the peer and remove the descriptor from the
2638 // event loop. CloseConnectin may be called at any time, including in a ConnectionCallback.
2640 typedef void (*TCPConnectionCallback
)(int sd
, void *context
, mDNSBool ConnectionEstablished
);
2641 extern mStatus
mDNSPlatformTCPConnect(const mDNSAddr
*dst
, mDNSOpaque16 dstport
, mDNSInterfaceID InterfaceID
,
2642 TCPConnectionCallback callback
, void *context
, int *descriptor
);
2643 extern void mDNSPlatformTCPCloseConnection(int sd
);
2644 extern int mDNSPlatformReadTCP(int sd
, void *buf
, int buflen
);
2645 extern int mDNSPlatformWriteTCP(int sd
, const char *msg
, int len
);
2647 // Platforms that support unicast browsing and dynamic update registration for clients who do not specify a domain
2648 // in browse/registration calls must implement these routines to get the "default" browse/registration list.
2649 // The Get() functions must return a linked list of DNameListElem structs, allocated via mDNSPlatformMemAllocate.
2650 // Platforms may implement the Get() calls via the mDNS_CopyDNameList() helper routine.
2651 // Callers should free lists obtained via the Get() calls with th mDNS_FreeDNameList routine, provided by the core.
2653 typedef struct DNameListElem
2656 struct DNameListElem
*next
;
2659 extern DNameListElem
*mDNSPlatformGetSearchDomainList(void);
2660 extern DNameListElem
*mDNSPlatformGetRegDomainList(void);
2662 // Helper functions provided by the core
2663 extern DNameListElem
*mDNS_CopyDNameList(const DNameListElem
*orig
);
2664 extern void mDNS_FreeDNameList(DNameListElem
*list
);
2666 #ifdef _LEGACY_NAT_TRAVERSAL_
2667 // Support for legacy NAT traversal protocols, implemented by the platform layer and callable by the core.
2669 #define DYN_PORT_MIN 49152 // ephemeral port range
2670 #define DYN_PORT_MAX 65535
2671 #define LEGACY_NATMAP_MAX_TRIES 4 // if our desired mapping is taken, how many times we try mapping to a random port
2673 extern mStatus
LNT_GetPublicIP(mDNSOpaque32
*ip
);
2674 extern mStatus
LNT_MapPort(mDNSIPPort priv
, mDNSIPPort pub
, mDNSBool tcp
);
2675 extern mStatus
LNT_UnmapPort(mDNSIPPort PubPort
, mDNSBool tcp
);
2676 #endif // _LEGACY_NAT_TRAVERSAL_
2678 // The core mDNS code provides these functions, for the platform support code to call at appropriate times
2680 // mDNS_SetFQDN() is called once on startup (typically from mDNSPlatformInit())
2681 // and then again on each subsequent change of the host name.
2683 // mDNS_RegisterInterface() is used by the platform support layer to inform mDNSCore of what
2684 // physical and/or logical interfaces are available for sending and receiving packets.
2685 // Typically it is called on startup for each available interface, but register/deregister may be
2686 // called again later, on multiple occasions, to inform the core of interface configuration changes.
2687 // If set->Advertise is set non-zero, then mDNS_RegisterInterface() also registers the standard
2688 // resource records that should be associated with every publicised IP address/interface:
2689 // -- Name-to-address records (A/AAAA)
2690 // -- Address-to-name records (PTR)
2691 // -- Host information (HINFO)
2692 // IMPORTANT: The specified mDNSInterfaceID MUST NOT be 0, -1, or -2; these values have special meaning
2693 // mDNS_RegisterInterface does not result in the registration of global hostnames via dynamic update -
2694 // see mDNS_SetPrimaryInterfaceInfo, mDNS_AddDynDNSHostName, etc. for this purpose.
2695 // Note that the set may be deallocated immediately after it is deregistered via mDNS_DeegisterInterface.
2697 // mDNS_RegisterDNS() is used by the platform support layer to provide the core with the addresses of
2698 // available domain name servers for unicast queries/updates. RegisterDNS() should be called once for
2699 // each name server, typically at startup, or when a new name server becomes available. DeregiterDNS()
2700 // must be called whenever a registered name server becomes unavailable. DeregisterDNSList deregisters
2701 // all registered servers. mDNS_DNSRegistered() returns true if one or more servers are registered in the core.
2703 // mDNSCoreInitComplete() is called when the platform support layer is finished.
2704 // Typically this is at the end of mDNSPlatformInit(), but may be later
2705 // (on platforms like OT that allow asynchronous initialization of the networking stack).
2707 // mDNSCoreReceive() is called when a UDP packet is received
2709 // mDNSCoreMachineSleep() is called when the machine sleeps or wakes
2710 // (This refers to heavyweight laptop-style sleep/wake that disables network access,
2711 // not lightweight second-by-second CPU power management modes.)
2713 extern void mDNS_SetFQDN(mDNS
*const m
);
2714 extern mStatus
mDNS_RegisterInterface (mDNS
*const m
, NetworkInterfaceInfo
*set
, mDNSs32 delay
);
2715 extern void mDNS_DeregisterInterface(mDNS
*const m
, NetworkInterfaceInfo
*set
);
2716 extern void mDNSCoreInitComplete(mDNS
*const m
, mStatus result
);
2717 extern void mDNSCoreReceive(mDNS
*const m
, void *const msg
, const mDNSu8
*const end
,
2718 const mDNSAddr
*const srcaddr
, const mDNSIPPort srcport
,
2719 const mDNSAddr
*const dstaddr
, const mDNSIPPort dstport
, const mDNSInterfaceID InterfaceID
);
2720 extern void mDNSCoreMachineSleep(mDNS
*const m
, mDNSBool wake
);
2722 extern mDNSBool
mDNSAddrIsDNSMulticast(const mDNSAddr
*ip
);
2724 // ***************************************************************************
2726 #pragma mark - Compile-Time assertion checks
2729 // Some C compiler cleverness. We can make the compiler check certain things for
2730 // us, and report compile-time errors if anything is wrong. The usual way to do
2731 // this would be to use a run-time "if" statement, but then you don't find out
2732 // what's wrong until you run the software. This way, if the assertion condition
2733 // is false, the array size is negative, and the complier complains immediately.
2735 struct mDNS_CompileTimeAssertionChecks
2737 // Check that the compiler generated our on-the-wire packet format structure definitions
2738 // properly packed, without adding padding bytes to align fields on 32-bit or 64-bit boundaries.
2739 char assert0
[(sizeof(rdataSRV
) == 262 ) ? 1 : -1];
2740 char assert1
[(sizeof(DNSMessageHeader
) == 12 ) ? 1 : -1];
2741 char assert2
[(sizeof(DNSMessage
) == 12+AbsoluteMaxDNSMessageData
) ? 1 : -1];
2742 char assert3
[(sizeof(mDNSs8
) == 1 ) ? 1 : -1];
2743 char assert4
[(sizeof(mDNSu8
) == 1 ) ? 1 : -1];
2744 char assert5
[(sizeof(mDNSs16
) == 2 ) ? 1 : -1];
2745 char assert6
[(sizeof(mDNSu16
) == 2 ) ? 1 : -1];
2746 char assert7
[(sizeof(mDNSs32
) == 4 ) ? 1 : -1];
2747 char assert8
[(sizeof(mDNSu32
) == 4 ) ? 1 : -1];
2748 char assert9
[(sizeof(mDNSOpaque16
) == 2 ) ? 1 : -1];
2749 char assertA
[(sizeof(mDNSOpaque32
) == 4 ) ? 1 : -1];
2750 char assertB
[(sizeof(mDNSOpaque128
) == 16 ) ? 1 : -1];
2751 char assertC
[(sizeof(CacheRecord
) >= sizeof(CacheGroup
) ) ? 1 : -1];
2754 // ***************************************************************************
projects / apple / mdnsresponder.git / blob