1/* -*- Mode: C; tab-width: 4 -*- 2 * 3 * Copyright (c) 2002-2003 Apple Computer, Inc. All rights reserved. 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 17 18 NOTE: 19 If you're building an application that uses DNS Service Discovery 20 this is probably NOT the header file you're looking for. 21 In most cases you will want to use /usr/include/dns_sd.h instead. 22 23 This header file defines the lowest level raw interface to mDNSCore, 24 which is appropriate *only* on tiny embedded systems where everything 25 runs in a single address space and memory is extremely constrained. 26 All the APIs here are malloc-free, which means that the caller is 27 responsible for passing in a pointer to the relevant storage that 28 will be used in the execution of that call, and (when called with 29 correct parameters) all the calls are guaranteed to succeed. There 30 is never a case where a call can suffer intermittent failures because 31 the implementation calls malloc() and sometimes malloc() returns NULL 32 because memory is so limited that no more is available. 33 This is primarily for devices that need to have precisely known fixed 34 memory requirements, with absolutely no uncertainty or run-time variation, 35 but that certainty comes at a cost of more difficult programming. 36 37 For applications running on general-purpose desktop operating systems 38 (Mac OS, Linux, Solaris, Windows, etc.) the API you should use is 39 /usr/include/dns_sd.h, which defines the API by which multiple 40 independent client processes communicate their DNS Service Discovery 41 requests to a single "mdnsd" daemon running in the background. 42 43 Even on platforms that don't run multiple independent processes in 44 multiple independent address spaces, you can still use the preferred 45 dns_sd.h APIs by linking in "dnssd_clientshim.c", which implements 46 the standard "dns_sd.h" API calls, allocates any required storage 47 using malloc(), and then calls through to the low-level malloc-free 48 mDNSCore routines defined here. This has the benefit that even though 49 you're running on a small embedded system with a single address space, 50 you can still use the exact same client C code as you'd use on a 51 general-purpose desktop system. 52 53 54 Change History (most recent first): 55 56$Log: mDNSEmbeddedAPI.h,v $ 57Revision 1.296.2.1 2006/08/29 06:24:22 cheshire 58Re-licensed mDNSResponder daemon source code under Apache License, Version 2.0 59 60Revision 1.296 2006/06/29 05:28:01 cheshire 61Added comment about mDNSlocal and mDNSexport 62 63Revision 1.295 2006/06/29 03:02:43 cheshire 64<rdar://problem/4607042> mDNSResponder NXDOMAIN and CNAME support 65 66Revision 1.294 2006/06/28 06:50:08 cheshire 67In future we may want to change definition of mDNSs32 from "signed long" to "signed int" 68I doubt anyone is building mDNSResponder on systems where int is 16-bits, 69but lets add a compile-time assertion to make sure. 70 71Revision 1.293 2006/06/12 18:00:43 cheshire 72To make code a little more defensive, check _ILP64 before _LP64, 73in case both are set by mistake on some platforms 74 75Revision 1.292 2006/03/19 17:00:57 cheshire 76Define symbol MaxMsg instead of using hard-coded constant value '80' 77 78Revision 1.291 2006/03/19 02:00:07 cheshire 79<rdar://problem/4073825> Improve logic for delaying packets after repeated interface transitions 80 81Revision 1.290 2006/03/08 22:42:23 cheshire 82Fix spelling mistake: LocalReverseMapomain -> LocalReverseMapDomain 83 84Revision 1.289 2006/02/26 00:54:41 cheshire 85Fixes to avoid code generation warning/error on FreeBSD 7 86 87Revision 1.288 2005/12/21 03:24:58 cheshire 88<rdar://problem/4388858> Code changes required to compile on EFI 89 90Revision 1.287 2005/10/20 00:10:33 cheshire 91<rdar://problem/4290265> Add check to avoid crashing NAT gateways that have buggy DNS relay code 92 93Revision 1.286 2005/09/24 01:09:40 cheshire 94Fix comment typos 95 96Revision 1.285 2005/09/16 20:57:47 cheshire 97Add macro mDNS_TimeNow_NoLock(m) to get properly adjusted time without also acquiring lock 98 99Revision 1.284 2005/07/29 18:04:22 ksekar 100<rdar://problem/4137930> Hostname registration should register IPv6 AAAA record with DNS Update 101 102Revision 1.283 2005/05/13 20:45:09 ksekar 103<rdar://problem/4074400> Rapid wide-area txt record updates don't work 104 105Revision 1.282 2005/03/16 00:42:32 ksekar 106<rdar://problem/4012279> Long-lived queries not working on Windows 107 108Revision 1.281 2005/02/25 17:47:44 ksekar 109<rdar://problem/4021868> SendServiceRegistration fails on wake from sleep 110 111Revision 1.280 2005/02/25 04:21:00 cheshire 112<rdar://problem/4015377> mDNS -F returns the same domain multiple times with different casing 113 114Revision 1.279 2005/02/17 01:56:14 cheshire 115Increase ifname field to 64 bytes 116 117Revision 1.278 2005/02/09 23:38:51 ksekar 118<rdar://problem/3993508> Reregister hostname when DNS server changes but IP address does not 119 120Revision 1.277 2005/02/09 23:31:12 ksekar 121<rdar://problem/3984374> NAT-PMP response callback should return a boolean indicating if the packet matched the request 122 123Revision 1.276 2005/02/01 19:33:29 ksekar 124<rdar://problem/3985239> Keychain format too restrictive 125 126Revision 1.275 2005/01/27 22:57:55 cheshire 127Fix compile errors on gcc4 128 129Revision 1.274 2005/01/19 21:01:54 ksekar 130<rdar://problem/3955355> uDNS needs to support subtype registration and browsing 131 132Revision 1.273 2005/01/19 19:15:31 ksekar 133Refinement to <rdar://problem/3954575> - Simplify mDNS_PurgeResultsForDomain logic and move into daemon layer 134 135Revision 1.272 2005/01/18 18:10:55 ksekar 136<rdar://problem/3954575> Use 10.4 resolver API to get search domains 137 138Revision 1.271 2005/01/15 00:56:41 ksekar 139<rdar://problem/3954575> Unicast services don't disappear when logging 140out of VPN 141 142Revision 1.270 2005/01/14 18:34:22 ksekar 143<rdar://problem/3954571> Services registered outside of firewall don't succeed after location change 144 145Revision 1.269 2005/01/11 22:50:52 ksekar 146Fixed constant naming (was using kLLQ_DefLease for update leases) 147 148Revision 1.268 2004/12/22 22:25:47 ksekar 149<rdar://problem/3734265> NATPMP: handle location changes 150 151Revision 1.267 2004/12/22 00:13:49 ksekar 152<rdar://problem/3873993> Change version, port, and polling interval for LLQ 153 154Revision 1.266 2004/12/18 03:13:45 cheshire 155<rdar://problem/3751638> kDNSServiceInterfaceIndexLocalOnly should return all local records 156 157Revision 1.265 2004/12/17 23:37:45 cheshire 158<rdar://problem/3485365> Guard against repeating wireless dissociation/re-association 159(and other repetitive configuration changes) 160 161Revision 1.264 2004/12/17 05:25:46 cheshire 162<rdar://problem/3925163> Shorten DNS-SD queries to avoid NAT bugs 163 164Revision 1.263 2004/12/16 20:40:25 cheshire 165Fix compile warnings 166 167Revision 1.262 2004/12/16 20:13:00 cheshire 168<rdar://problem/3324626> Cache memory management improvements 169 170Revision 1.261 2004/12/14 21:21:20 ksekar 171<rdar://problem/3825979> NAT-PMP: Update response format to contain "Seconds Since Boot" 172 173Revision 1.260 2004/12/12 23:51:42 ksekar 174<rdar://problem/3845683> Wide-area registrations should fallback to using DHCP hostname as target 175 176Revision 1.259 2004/12/11 20:55:29 ksekar 177<rdar://problem/3916479> Clean up registration state machines 178 179Revision 1.258 2004/12/10 20:48:32 cheshire 180<rdar://problem/3705229> Need to pick final EDNS numbers for LLQ and GC 181 182Revision 1.257 2004/12/10 02:09:23 cheshire 183<rdar://problem/3898376> Modify default TTLs 184 185Revision 1.256 2004/12/09 03:15:40 ksekar 186<rdar://problem/3806610> use _legacy instead of _default to find "empty string" browse domains 187 188Revision 1.255 2004/12/07 22:48:37 cheshire 189Tidying 190 191Revision 1.254 2004/12/07 21:26:04 ksekar 192<rdar://problem/3908336> DNSServiceRegisterRecord() can crash on deregistration 193 194Revision 1.253 2004/12/07 20:42:33 cheshire 195Add explicit context parameter to mDNS_RemoveRecordFromService() 196 197Revision 1.252 2004/12/07 03:02:12 ksekar 198Fixed comments, grouped unicast-specific routines together 199 200Revision 1.251 2004/12/06 21:15:22 ksekar 201<rdar://problem/3884386> mDNSResponder crashed in CheckServiceRegistrations 202 203Revision 1.250 2004/12/04 02:12:45 cheshire 204<rdar://problem/3517236> mDNSResponder puts LargeCacheRecord on the stack 205 206Revision 1.249 2004/12/03 05:18:33 ksekar 207<rdar://problem/3810596> mDNSResponder needs to return more specific TSIG errors 208 209Revision 1.248 2004/12/02 20:03:48 ksekar 210<rdar://problem/3889647> Still publishes wide-area domains even after switching to a local subnet 211 212Revision 1.247 2004/12/01 20:57:19 ksekar 213<rdar://problem/3873921> Wide Area Service Discovery must be split-DNS aware 214 215Revision 1.246 2004/11/29 23:26:32 cheshire 216Added NonZeroTime() function, which usually returns the value given, with the exception 217that if the value given is zero, it returns one instead. For timer values where zero is 218used to mean "not set", this can be used to ensure that setting them to the result of an 219interval computation (e.g. "now+interval") does not inadvertently result in a zero value. 220 221Revision 1.245 2004/11/25 01:28:09 cheshire 222<rdar://problem/3557050> Need to implement random delay for 'QU' unicast replies (and set cache flush bit too) 223 224Revision 1.244 2004/11/24 22:00:59 cheshire 225Move definition of mDNSAddressIsAllDNSLinkGroup() from mDNSMacOSX.c to mDNSEmbeddedAPI.h 226 227Revision 1.243 2004/11/23 22:43:53 cheshire 228Tidy up code alignment 229 230Revision 1.242 2004/11/23 03:39:46 cheshire 231Let interface name/index mapping capability live directly in JNISupport.c, 232instead of having to call through to the daemon via IPC to get this information. 233 234Revision 1.241 2004/11/22 17:16:19 ksekar 235<rdar://problem/3854298> Unicast services don't disappear when you disable all networking 236 237Revision 1.240 2004/11/19 02:32:43 ksekar 238Wide-Area Security: Add LLQ-ID to events 239 240Revision 1.239 2004/11/15 20:09:23 ksekar 241<rdar://problem/3719050> Wide Area support for Add/Remove record 242 243Revision 1.238 2004/11/12 03:16:48 rpantos 244rdar://problem/3809541 Add mDNSPlatformGetInterfaceByName, mDNSPlatformGetInterfaceName 245 246Revision 1.237 2004/11/10 20:40:53 ksekar 247<rdar://problem/3868216> LLQ mobility fragile on non-primary interface 248 249Revision 1.236 2004/11/01 20:36:11 ksekar 250<rdar://problem/3802395> mDNSResponder should not receive Keychain Notifications 251 252Revision 1.235 2004/11/01 17:48:14 cheshire 253Changed SOA serial number back to signed. RFC 1035 may describe it as "unsigned", but 254it's wrong. The SOA serial is a modular counter, as explained in "DNS & BIND", page 255137. Since C doesn't have a modular type, we used signed, C's closest approximation. 256 257Revision 1.234 2004/10/29 21:59:02 ksekar 258SOA serial should be a unsigned integer, as per RFC 1035 259 260Revision 1.233 2004/10/28 03:24:41 cheshire 261Rename m->CanReceiveUnicastOn as m->CanReceiveUnicastOn5353 262 263Revision 1.232 2004/10/26 06:20:23 cheshire 264Add mDNSAddressIsValidNonZero() macro 265 266Revision 1.231 2004/10/26 06:11:41 cheshire 267Add improved logging to aid in diagnosis of <rdar://problem/3842714> mDNSResponder crashed 268 269Revision 1.230 2004/10/26 03:52:02 cheshire 270Update checkin comments 271 272Revision 1.229 2004/10/25 19:30:52 ksekar 273<rdar://problem/3827956> Simplify dynamic host name structures 274 275Revision 1.228 2004/10/23 01:16:00 cheshire 276<rdar://problem/3851677> uDNS operations not always reliable on multi-homed hosts 277 278Revision 1.227 2004/10/22 20:52:07 ksekar 279<rdar://problem/3799260> Create NAT port mappings for Long Lived Queries 280 281Revision 1.226 2004/10/20 01:50:40 cheshire 282<rdar://problem/3844991> Cannot resolve non-local registrations using the mach API 283Implemented ForceMCast mode for AuthRecords as well as for Questions 284 285Revision 1.225 2004/10/19 21:33:17 cheshire 286<rdar://problem/3844991> Cannot resolve non-local registrations using the mach API 287Added flag 'kDNSServiceFlagsForceMulticast'. Passing through an interface id for a unicast name 288doesn't force multicast unless you set this flag to indicate explicitly that this is what you want 289 290Revision 1.224 2004/10/16 00:16:59 cheshire 291<rdar://problem/3770558> Replace IP TTL 255 check with local subnet source address check 292 293Revision 1.223 2004/10/15 23:00:17 ksekar 294<rdar://problem/3799242> Need to update LLQs on location changes 295 296Revision 1.222 2004/10/12 02:49:20 ksekar 297<rdar://problem/3831228> Clean up LLQ sleep/wake, error handling 298 299Revision 1.221 2004/10/10 06:57:15 cheshire 300Change definition of "localdomain" to make code compile a little smaller 301 302Revision 1.220 2004/10/06 01:44:19 cheshire 303<rdar://problem/3813936> Resolving too quickly sometimes returns stale TXT record 304 305Revision 1.219 2004/10/03 23:18:58 cheshire 306Move address comparison macros from DNSCommon.h to mDNSEmbeddedAPI.h 307 308Revision 1.218 2004/10/03 23:14:12 cheshire 309Add "mDNSEthAddr" type and "zeroEthAddr" constant 310 311Revision 1.217 2004/09/30 00:24:56 ksekar 312<rdar://problem/3695802> Dynamically update default registration domains on config change 313 314Revision 1.216 2004/09/27 23:24:32 cheshire 315Fix typo: SOA refresh interval is supposed to be unsigned 316 317Revision 1.215 2004/09/26 23:20:35 ksekar 318<rdar://problem/3813108> Allow default registrations in multiple wide-area domains 319 320Revision 1.214 2004/09/25 02:41:39 cheshire 321<rdar://problem/3637266> Deliver near-pending "remove" events before new "add" events 322 323Revision 1.213 2004/09/25 02:24:27 cheshire 324Removed unused rr->UseCount 325 326Revision 1.212 2004/09/24 20:57:39 cheshire 327<rdar://problem/3680902> Eliminate inappropriate casts that cause misaligned-address errors 328 329Revision 1.211 2004/09/24 20:33:22 cheshire 330Remove unused DNSDigest_MD5 declaration 331 332Revision 1.210 2004/09/23 20:21:07 cheshire 333<rdar://problem/3426876> Refine "immediate answer burst; restarting exponential backoff sequence" logic 334Associate a unique sequence number with each received packet, and only increment the count of recent answer 335packets if the packet sequence number for this answer record is not one we've already seen and counted. 336 337Revision 1.209 2004/09/23 20:14:39 cheshire 338Rename "question->RecentAnswers" to "question->RecentAnswerPkts" 339 340Revision 1.208 2004/09/23 00:50:53 cheshire 341<rdar://problem/3419452> Don't send a (DE) if a service is unregistered after wake from sleep 342 343Revision 1.207 2004/09/22 02:34:46 cheshire 344Move definitions of default TTL times from mDNS.c to mDNSEmbeddedAPI.h 345 346Revision 1.206 2004/09/22 00:41:59 cheshire 347Move tcp connection status codes into the legal range allocated for mDNS use 348 349Revision 1.205 2004/09/21 23:40:11 ksekar 350<rdar://problem/3810349> mDNSResponder to return errors on NAT traversal failure 351 352Revision 1.204 2004/09/21 23:29:50 cheshire 353<rdar://problem/3680045> DNSServiceResolve should delay sending packets 354 355Revision 1.203 2004/09/21 20:58:22 cheshire 356Add ifname field to NetworkInterfaceInfo_struct 357 358Revision 1.202 2004/09/17 00:46:34 cheshire 359mDNS_TimeNow should take const mDNS parameter 360 361Revision 1.201 2004/09/17 00:31:51 cheshire 362For consistency with ipv6, renamed rdata field 'ip' to 'ipv4' 363 364Revision 1.200 2004/09/17 00:19:10 cheshire 365For consistency with AllDNSLinkGroupv6, rename AllDNSLinkGroup to AllDNSLinkGroupv4 366 367Revision 1.199 2004/09/16 21:59:16 cheshire 368For consistency with zerov6Addr, rename zeroIPAddr to zerov4Addr 369 370Revision 1.198 2004/09/16 21:36:36 cheshire 371<rdar://problem/3803162> Fix unsafe use of mDNSPlatformTimeNow() 372Changes to add necessary locking calls around unicast DNS operations 373 374Revision 1.197 2004/09/16 00:24:48 cheshire 375<rdar://problem/3803162> Fix unsafe use of mDNSPlatformTimeNow() 376 377Revision 1.196 2004/09/14 23:42:35 cheshire 378<rdar://problem/3801296> Need to seed random number generator from platform-layer data 379 380Revision 1.195 2004/09/14 23:27:46 cheshire 381Fix compile errors 382 383Revision 1.194 2004/09/10 00:49:57 cheshire 384<rdar://problem/3787644> Add error code kDNSServiceErr_Firewall, for future use 385 386Revision 1.193 2004/09/03 19:23:05 ksekar 387<rdar://problem/3788460>: Need retransmission mechanism for wide-area service registrations 388 389Revision 1.192 2004/09/02 03:48:47 cheshire 390<rdar://problem/3709039> Disable targeted unicast query support by default 3911. New flag kDNSServiceFlagsAllowRemoteQuery to indicate we want to allow remote queries for this record 3922. New field AllowRemoteQuery in AuthRecord structure 3933. uds_daemon.c sets AllowRemoteQuery if kDNSServiceFlagsAllowRemoteQuery is set 3944. mDNS.c only answers remote queries if AllowRemoteQuery is set 395 396Revision 1.191 2004/08/25 00:37:27 ksekar 397<rdar://problem/3774635>: Cleanup DynDNS hostname registration code 398 399Revision 1.190 2004/08/18 17:35:41 ksekar 400<rdar://problem/3651443>: Feature #9586: Need support for Legacy NAT gateways 401 402Revision 1.189 2004/08/14 03:22:41 cheshire 403<rdar://problem/3762579> Dynamic DNS UI <-> mDNSResponder glue 404Add GetUserSpecifiedDDNSName() routine 405Convert ServiceRegDomain to domainname instead of C string 406Replace mDNS_GenerateFQDN/mDNS_GenerateGlobalFQDN with mDNS_SetFQDNs 407 408Revision 1.188 2004/08/13 23:46:58 cheshire 409"asyncronous" -> "asynchronous" 410 411Revision 1.187 2004/08/13 23:37:02 cheshire 412Now that we do both uDNS and mDNS, global replace "uDNS_info.hostname" with 413"uDNS_info.UnicastHostname" for clarity 414 415Revision 1.186 2004/08/13 23:25:00 cheshire 416Now that we do both uDNS and mDNS, global replace "m->hostname" with 417"m->MulticastHostname" for clarity 418 419Revision 1.185 2004/08/12 00:32:36 ksekar 420<rdar://problem/3759567>: LLQ Refreshes never terminate if unanswered 421 422Revision 1.184 2004/08/11 17:09:31 cheshire 423Add comment clarifying the applicability of these APIs 424 425Revision 1.183 2004/08/10 23:19:14 ksekar 426<rdar://problem/3722542>: DNS Extension daemon for Wide Area Service Discovery 427Moved routines/constants to allow extern access for garbage collection daemon 428 429Revision 1.182 2004/07/30 17:40:06 ksekar 430<rdar://problem/3739115>: TXT Record updates not available for wide-area services 431 432Revision 1.181 2004/07/29 19:27:15 ksekar 433NATPMP Support - minor fixes and cleanup 434 435Revision 1.180 2004/07/29 02:03:35 ksekar 436Delete unused #define and structure field 437 438Revision 1.179 2004/07/26 22:49:30 ksekar 439<rdar://problem/3651409>: Feature #9516: Need support for NATPMP in client 440 441Revision 1.178 2004/07/13 21:24:24 rpantos 442Fix for <rdar://problem/3701120>. 443 444Revision 1.177 2004/06/05 00:04:26 cheshire 445<rdar://problem/3668639>: wide-area domains should be returned in reg. domain enumeration 446 447Revision 1.176 2004/06/04 08:58:29 ksekar 448<rdar://problem/3668624>: Keychain integration for secure dynamic update 449 450Revision 1.175 2004/06/04 00:15:06 cheshire 451Move misplaced brackets 452 453Revision 1.174 2004/06/03 23:30:16 cheshire 454Remove extraneous blank lines and white space 455 456Revision 1.173 2004/06/03 03:09:58 ksekar 457<rdar://problem/3668626>: Garbage Collection for Dynamic Updates 458 459Revision 1.172 2004/06/01 23:46:50 ksekar 460<rdar://problem/3675149>: DynDNS: dynamically look up LLQ/Update ports 461 462Revision 1.171 2004/05/28 23:42:37 ksekar 463<rdar://problem/3258021>: Feature: DNS server->client notification on record changes (#7805) 464 465Revision 1.170 2004/05/18 23:51:25 cheshire 466Tidy up all checkin comments to use consistent "<rdar://problem/xxxxxxx>" format for bug numbers 467 468Revision 1.169 2004/05/13 04:54:20 ksekar 469Unified list copy/free code. Added symetric list for 470 471Revision 1.168 2004/05/12 22:03:09 ksekar 472Made GetSearchDomainList a true platform-layer call (declaration moved 473from mDNSMacOSX.h to mDNSEmbeddedAPI.h), implemented to return "local" 474only on non-OSX platforms. Changed call to return a copy of the list 475to avoid shared memory issues. Added a routine to free the list. 476 477Revision 1.167 2004/04/22 04:07:01 cheshire 478Fix from Bob Bradley: Don't try to do inline functions on compilers that don't support it 479 480Revision 1.166 2004/04/22 03:15:56 cheshire 481Fix use of "struct __attribute__((__packed__))" so it only applies on GCC >= 2.9 482 483Revision 1.165 2004/04/22 03:05:28 cheshire 484kDNSClass_ANY should be kDNSQClass_ANY 485 486Revision 1.164 2004/04/21 02:55:03 cheshire 487Update comments describing 'InterfaceActive' field 488 489Revision 1.163 2004/04/21 02:49:11 cheshire 490To reduce future confusion, renamed 'TxAndRx' to 'McastTxRx' 491 492Revision 1.162 2004/04/15 00:51:28 bradley 493Minor tweaks for Windows and C++ builds. Added casts for signed/unsigned integers and 64-bit pointers. 494Prefix some functions with mDNS to avoid conflicts. Disable benign warnings on Microsoft compilers. 495 496Revision 1.161 2004/04/14 23:09:28 ksekar 497Support for TSIG signed dynamic updates. 498 499Revision 1.160 2004/04/09 17:40:26 cheshire 500Remove unnecessary "Multicast" field -- it duplicates the semantics of the existing McastTxRx field 501 502Revision 1.159 2004/04/09 16:37:15 cheshire 503Suggestion from Bob Bradley: 504Move NumCacheRecordsForInterfaceID() to DNSCommon.c so it's available to all platform layers 505 506Revision 1.158 2004/04/02 19:38:33 cheshire 507Update comment about typical RR TTLs 508 509Revision 1.157 2004/04/02 19:35:53 cheshire 510Add clarifying comments about legal mDNSInterfaceID values 511 512Revision 1.156 2004/04/02 19:19:48 cheshire 513Add code to do optional logging of multi-packet KA list time intervals 514 515Revision 1.155 2004/03/24 00:29:45 ksekar 516Make it safe to call StopQuery in a unicast question callback 517 518Revision 1.154 2004/03/20 01:05:49 cheshire 519Test __LP64__ and __ILP64__ to compile properly on a wider range of 64-bit architectures 520 521Revision 1.153 2004/03/13 01:57:33 ksekar 522<rdar://problem/3192546>: DynDNS: Dynamic update of service records 523 524Revision 1.152 2004/03/09 02:27:16 cheshire 525Remove erroneous underscore in 'packed_struct' (makes no difference now, but might in future) 526 527Revision 1.151 2004/03/02 03:21:56 cheshire 528<rdar://problem/3549576> Properly support "_services._dns-sd._udp" meta-queries 529 530Revision 1.150 2004/02/21 02:06:24 cheshire 531Can't use anonymous unions -- they're non-standard and don't work on all compilers 532 533Revision 1.149 2004/02/06 23:04:19 ksekar 534Basic Dynamic Update support via mDNS_Register (dissabled via 535UNICAST_REGISTRATION #define) 536 537Revision 1.148 2004/02/03 19:47:36 ksekar 538Added an asynchronous state machine mechanism to uDNS.c, including 539calls to find the parent zone for a domain name. Changes include code 540in repository previously dissabled via "#if 0 incomplete". Codepath 541is currently unused, and will be called to create update records, etc. 542 543Revision 1.147 2004/02/03 18:57:35 cheshire 544Update comment for "IsLocalDomain()" 545 546Revision 1.146 2004/01/30 02:20:24 bradley 547Map inline to __inline when building with Microsoft C compilers since they do not support C99 inline. 548 549Revision 1.145 2004/01/29 02:59:17 ksekar 550Unicast DNS: Changed from a resource record oriented question/response 551matching to packet based matching. New callback architecture allows 552collections of records in a response to be processed differently 553depending on the nature of the request, and allows the same structure 554to be used for internal and client-driven queries with different processing needs. 555 556Revision 1.144 2004/01/28 20:20:45 ksekar 557Unified ActiveQueries and ActiveInternalQueries lists, using a flag to 558demux them. Check-in includes work-in-progress code, #ifdef'd out. 559 560Revision 1.143 2004/01/28 03:41:00 cheshire 561<rdar://problem/3541946>: Need ability to do targeted queries as well as multicast queries 562 563Revision 1.142 2004/01/28 02:30:07 ksekar 564Added default Search Domains to unicast browsing, controlled via 565Networking sharing prefs pane. Stopped sending unicast messages on 566every interface. Fixed unicast resolving via mach-port API. 567 568Revision 1.141 2004/01/27 20:15:22 cheshire 569<rdar://problem/3541288>: Time to prune obsolete code for listening on port 53 570 571Revision 1.140 2004/01/24 23:37:08 cheshire 572At Kiren's suggestion, made functions to convert mDNSOpaque16s to/from integer values 573 574Revision 1.139 2004/01/24 08:46:26 bradley 575Added InterfaceID<->Index platform interfaces since they are now used by all platforms for the DNS-SD APIs. 576 577Revision 1.138 2004/01/24 04:59:15 cheshire 578Fixes so that Posix/Linux, OS9, Windows, and VxWorks targets build again 579 580Revision 1.137 2004/01/24 03:40:56 cheshire 581Move mDNSAddrIsDNSMulticast() from DNSCommon.h to mDNSEmbeddedAPI.h so clients can use it 582 583Revision 1.136 2004/01/24 03:38:27 cheshire 584Fix minor syntactic error: Headers should use "extern" declarations, not "mDNSexport" 585 586Revision 1.135 2004/01/23 23:23:15 ksekar 587Added TCP support for truncated unicast messages. 588 589Revision 1.134 2004/01/22 03:54:11 cheshire 590Create special meta-interface 'mDNSInterface_ForceMCast' (-2), 591which means "do this query via multicast, even if it's apparently a unicast domain" 592 593Revision 1.133 2004/01/22 03:48:41 cheshire 594Make sure uDNS client doesn't accidentally use query ID zero 595 596Revision 1.132 2004/01/22 03:43:08 cheshire 597Export constants like mDNSInterface_LocalOnly so that the client layers can use them 598 599Revision 1.131 2004/01/21 21:53:18 cheshire 600<rdar://problem/3448144>: Don't try to receive unicast responses if we're not the first to bind to the UDP port 601 602Revision 1.130 2003/12/14 05:05:29 cheshire 603Add comments explaining mDNS_Init_NoCache and mDNS_Init_ZeroCacheSize 604 605Revision 1.129 2003/12/13 03:05:27 ksekar 606<rdar://problem/3192548>: DynDNS: Unicast query of service records 607 608Revision 1.128 2003/12/01 21:44:23 cheshire 609Add mStatus_BadInterfaceErr = -65552 for consistency with dns_sd.h 610 611Revision 1.127 2003/12/01 18:26:37 cheshire 612Also pack the OpaqueXX union types. Otherwise, on some systems, mDNSOpaque16 is four bytes! 613 614Revision 1.126 2003/12/01 18:23:48 cheshire 615<rdar://problem/3464646>: Scalar size problem in mDNS code on some 64-bit architectures 616 617Revision 1.125 2003/11/22 00:18:27 cheshire 618Add compile-time asserts to verify correct sizes of mDNSu32, mDNSOpaque16, etc. 619 620Revision 1.124 2003/11/20 22:59:54 cheshire 621Changed runtime checks in mDNS.c to be compile-time checks in mDNSEmbeddedAPI.h 622Thanks to Bob Bradley for suggesting the ingenious compiler trick to make this work. 623 624Revision 1.123 2003/11/20 22:53:01 cheshire 625Add comment about MAX_ESCAPED_DOMAIN_LABEL 626 627Revision 1.122 2003/11/20 20:49:53 cheshire 628Another fix from HP: Use packedstruct macro to ensure proper packing for on-the-wire packet structures 629 630Revision 1.121 2003/11/20 05:01:38 cheshire 631Update comments; add explanation of Advertise/DontAdvertiseLocalAddresses 632 633Revision 1.120 2003/11/14 20:59:08 cheshire 634Clients can't use AssignDomainName macro because mDNSPlatformMemCopy is defined in mDNSPlatformFunctions.h. 635Best solution is just to combine mDNSEmbeddedAPI.h and mDNSPlatformFunctions.h into a single file. 636 637Revision 1.119 2003/11/14 19:47:52 cheshire 638Define symbol MAX_ESCAPED_DOMAIN_NAME to indicate recommended buffer size for ConvertDomainNameToCString 639 640Revision 1.118 2003/11/14 19:18:34 cheshire 641Move AssignDomainName macro to mDNSEmbeddedAPI.h to that client layers can use it too 642 643Revision 1.117 2003/11/08 23:32:24 cheshire 644Gave name to anonymous struct, to avoid errors on certain compilers. 645(Thanks to ramaprasad.kr@hp.com for reporting this.) 646 647Revision 1.116 2003/11/07 03:32:56 cheshire 648<rdar://problem/3472153> mDNSResponder delivers answers in inconsistent order 649This is the real fix. Checkin 1.312 was overly simplistic; Calling GetFreeCacheRR() can sometimes 650purge records from the cache, causing tail pointer *rp to be stale on return. The correct fix is 651to maintain a system-wide tail pointer for each cache slot, and then if neccesary GetFreeCacheRR() 652can update this pointer, so that mDNSCoreReceiveResponse() appends records in the right place. 653 654Revision 1.115 2003/09/23 00:53:54 cheshire 655NumFailedProbes should be unsigned 656 657Revision 1.114 2003/08/29 19:44:15 cheshire 658<rdar://problem/3400967> Traffic reduction: Eliminate synchronized QUs when a new service appears 6591. Use m->RandomQueryDelay to impose a random delay in the range 0-500ms on queries 660 that already have at least one unique answer in the cache 6612. For these queries, go straight to QM, skipping QU 662 663Revision 1.113 2003/08/21 19:31:58 cheshire 664Cosmetic: Swap order of fields 665 666Revision 1.112 2003/08/21 19:27:36 cheshire 667<rdar://problem/3387878> Traffic reduction: No need to announce record for longer than TTL 668 669Revision 1.111 2003/08/21 02:21:50 cheshire 670<rdar://problem/3386473> Efficiency: Reduce repeated queries 671 672Revision 1.110 2003/08/20 23:39:31 cheshire 673<rdar://problem/3344098> Review syslog messages, and remove as appropriate 674 675Revision 1.109 2003/08/19 22:24:10 cheshire 676Comment change 677 678Revision 1.108 2003/08/19 22:20:00 cheshire 679<rdar://problem/3376721> Don't use IPv6 on interfaces that have a routable IPv4 address configured 680More minor refinements 681 682Revision 1.107 2003/08/19 06:48:25 cheshire 683<rdar://problem/3376552> Guard against excessive record updates 684Each record starts with 10 UpdateCredits. 685Every update consumes one UpdateCredit. 686UpdateCredits are replenished at a rate of one one per minute, up to a maximum of 10. 687As the number of UpdateCredits declines, the number of announcements is similarly scaled back. 688When fewer than 5 UpdateCredits remain, the first announcement is also delayed by an increasing amount. 689 690Revision 1.106 2003/08/19 04:49:28 cheshire 691<rdar://problem/3368159> Interaction between v4, v6 and dual-stack hosts not working quite right 6921. A dual-stack host should only suppress its own query if it sees the same query from other hosts on BOTH IPv4 and IPv6. 6932. When we see the first v4 (or first v6) member of a group, we re-trigger questions and probes on that interface. 6943. When we see the last v4 (or v6) member of a group go away, we revalidate all the records received on that interface. 695 696Revision 1.105 2003/08/19 02:33:37 cheshire 697Update comments 698 699Revision 1.104 2003/08/19 02:31:11 cheshire 700<rdar://problem/3378386> mDNSResponder overenthusiastic with final expiration queries 701Final expiration queries now only mark the question for sending on the particular interface 702pertaining to the record that's expiring. 703 704Revision 1.103 2003/08/18 19:05:44 cheshire 705<rdar://problem/3382423> UpdateRecord not working right 706Added "newrdlength" field to hold new length of updated rdata 707 708Revision 1.102 2003/08/16 03:39:00 cheshire 709<rdar://problem/3338440> InterfaceID -1 indicates "local only" 710 711Revision 1.101 2003/08/15 20:16:02 cheshire 712<rdar://problem/3366590> mDNSResponder takes too much RPRVT 713We want to avoid touching the rdata pages, so we don't page them in. 7141. RDLength was stored with the rdata, which meant touching the page just to find the length. 715 Moved this from the RData to the ResourceRecord object. 7162. To avoid unnecessarily touching the rdata just to compare it, 717 compute a hash of the rdata and store the hash in the ResourceRecord object. 718 719Revision 1.100 2003/08/14 19:29:04 cheshire 720<rdar://problem/3378473> Include cache records in SIGINFO output 721Moved declarations of DNSTypeName() and GetRRDisplayString to mDNSEmbeddedAPI.h so daemon.c can use them 722 723Revision 1.99 2003/08/14 02:17:05 cheshire 724<rdar://problem/3375491> Split generic ResourceRecord type into two separate types: AuthRecord and CacheRecord 725 726Revision 1.98 2003/08/12 19:56:23 cheshire 727Update to APSL 2.0 728 729Revision 1.97 2003/08/12 14:59:27 cheshire 730<rdar://problem/3374490> Rate-limiting blocks some legitimate responses 731When setting LastMCTime also record LastMCInterface. When checking LastMCTime to determine 732whether to suppress the response, also check LastMCInterface to see if it matches. 733 734Revision 1.96 2003/08/12 13:57:04 cheshire 735<rdar://problem/3323817> Improve cache performance 736Changed the number of hash table slots from 37 to 499 737 738Revision 1.95 2003/08/09 00:55:02 cheshire 739<rdar://problem/3366553> mDNSResponder is taking 20-30% of the CPU 740Don't scan the whole cache after every packet. 741 742Revision 1.94 2003/08/09 00:35:29 cheshire 743 744Revision 1.93 2003/08/08 18:55:48 cheshire 745<rdar://problem/3370365> Guard against time going backwards 746 747Revision 1.92 2003/08/08 18:36:04 cheshire 748<rdar://problem/3344154> Only need to revalidate on interface removal on platforms that have the PhantomInterfaces bug 749 750Revision 1.91 2003/08/06 21:33:39 cheshire 751Fix compiler warnings on PocketPC 2003 (Windows CE) 752 753Revision 1.90 2003/08/06 20:30:17 cheshire 754Add structure definition for rdataMX (not currently used, but good to have it for completeness) 755 756Revision 1.89 2003/08/06 18:58:19 cheshire 757Update comments 758 759Revision 1.88 2003/07/24 23:45:44 cheshire 760To eliminate compiler warnings, changed definition of mDNSBool from 761"unsigned char" to "int", since "int" is in fact truly the type that C uses 762for the result of comparison operators (a<b) and logical operators (a||b) 763 764Revision 1.87 2003/07/22 23:57:20 cheshire 765Move platform-layer function prototypes from mDNSEmbeddedAPI.h to mDNSPlatformFunctions.h where they belong 766 767Revision 1.86 2003/07/20 03:52:02 ksekar 768<rdar://problem/3320722>: Feature: New DNS-SD APIs (#7875) (mDNSResponder component) 769Added error type for incompatibility between daemon and client versions 770 771Revision 1.85 2003/07/19 03:23:13 cheshire 772<rdar://problem/2986147> mDNSResponder needs to receive and cache larger records 773 774Revision 1.84 2003/07/18 23:52:12 cheshire 775To improve consistency of field naming, global search-and-replace: 776NextProbeTime -> NextScheduledProbe 777NextResponseTime -> NextScheduledResponse 778 779Revision 1.83 2003/07/18 00:29:59 cheshire 780<rdar://problem/3268878> Remove mDNSResponder version from packet header and use HINFO record instead 781 782Revision 1.82 2003/07/17 17:35:04 cheshire 783<rdar://problem/3325583> Rate-limit responses, to guard against packet flooding 784 785Revision 1.81 2003/07/16 05:01:36 cheshire 786Add fields 'LargeAnswers' and 'ExpectUnicastResponse' in preparation for 787<rdar://problem/3315761> Need to implement "unicast response" request, using top bit of qclass 788 789Revision 1.80 2003/07/15 01:55:12 cheshire 790<rdar://problem/3315777> Need to implement service registration with subtypes 791 792Revision 1.79 2003/07/13 02:28:00 cheshire 793<rdar://problem/3325166> SendResponses didn't all its responses 794Delete all references to RRInterfaceActive -- it's now superfluous 795 796Revision 1.78 2003/07/13 01:47:53 cheshire 797Fix one error and one warning in the Windows build 798 799Revision 1.77 2003/07/11 01:32:38 cheshire 800Syntactic cleanup (no change to funcationality): Now that we only have one host name, 801rename field "hostname1" to "hostname", and field "RR_A1" to "RR_A". 802 803Revision 1.76 2003/07/11 01:28:00 cheshire 804<rdar://problem/3161289> No more local.arpa 805 806Revision 1.75 2003/07/02 21:19:45 cheshire 807<rdar://problem/3313413> Update copyright notices, etc., in source code comments 808 809Revision 1.74 2003/07/02 02:41:23 cheshire 810<rdar://problem/2986146> mDNSResponder needs to start with a smaller cache and then grow it as needed 811 812Revision 1.73 2003/06/10 04:24:39 cheshire 813<rdar://problem/3283637> React when we observe other people query unsuccessfully for a record that's in our cache 814Some additional refinements: 815Don't try to do this for unicast-response queries 816better tracking of Qs and KAs in multi-packet KA lists 817 818Revision 1.72 2003/06/10 01:46:27 cheshire 819Add better comments explaining how these data structures are intended to be used from the client layer 820 821Revision 1.71 2003/06/07 06:45:05 cheshire 822<rdar://problem/3283666> No need for multiple machines to all be sending the same queries 823 824Revision 1.70 2003/06/07 04:50:53 cheshire 825<rdar://problem/3283637> React when we observe other people query unsuccessfully for a record that's in our cache 826 827Revision 1.69 2003/06/07 04:22:17 cheshire 828Add MsgBuffer for error log and debug messages 829 830Revision 1.68 2003/06/07 01:46:38 cheshire 831<rdar://problem/3283540> When query produces zero results, call mDNS_Reconfirm() on any antecedent records 832 833Revision 1.67 2003/06/07 01:22:14 cheshire 834<rdar://problem/3283516> mDNSResponder needs an mDNS_Reconfirm() function 835 836Revision 1.66 2003/06/07 00:59:43 cheshire 837<rdar://problem/3283454> Need some randomness to spread queries on the network 838 839Revision 1.65 2003/06/06 21:41:11 cheshire 840For consistency, mDNS_StopQuery() should return an mStatus result, just like all the other mDNSCore routines 841 842Revision 1.64 2003/06/06 21:38:55 cheshire 843Renamed 'NewData' as 'FreshData' (The data may not be new data, just a refresh of data that we 844already had in our cache. This refreshes our TTL on the data, but the data itself stays the same.) 845 846Revision 1.63 2003/06/06 17:20:14 cheshire 847For clarity, rename question fields name/rrtype/rrclass as qname/qtype/qclass 848(Global search-and-replace; no functional change to code execution.) 849 850Revision 1.62 2003/06/04 01:25:33 cheshire 851<rdar://problem/3274950> Cannot perform multi-packet known-answer suppression messages 852Display time interval between first and subsequent queries 853 854Revision 1.61 2003/06/03 05:02:16 cheshire 855<rdar://problem/3277080> Duplicate registrations not handled as efficiently as they should be 856 857Revision 1.60 2003/05/31 00:09:49 cheshire 858<rdar://problem/3274862> Add ability to discover what services are on a network 859 860Revision 1.59 2003/05/29 06:11:35 cheshire 861<rdar://problem/3272214>: Report if there appear to be too many "Resolve" callbacks 862 863Revision 1.58 2003/05/29 05:48:06 cheshire 864Minor fix for when generating printf warnings: mDNS_snprintf arguments are now 3,4 865 866Revision 1.57 2003/05/26 03:21:27 cheshire 867Tidy up address structure naming: 868mDNSIPAddr => mDNSv4Addr (for consistency with mDNSv6Addr) 869mDNSAddr.addr.ipv4 => mDNSAddr.ip.v4 870mDNSAddr.addr.ipv6 => mDNSAddr.ip.v6 871 872Revision 1.56 2003/05/26 03:01:27 cheshire 873<rdar://problem/3268904> sprintf/vsprintf-style functions are unsafe; use snprintf/vsnprintf instead 874 875Revision 1.55 2003/05/26 00:47:30 cheshire 876Comment clarification 877 878Revision 1.54 2003/05/24 16:39:48 cheshire 879<rdar://problem/3268631> SendResponses also needs to handle multihoming better 880 881Revision 1.53 2003/05/23 02:15:37 cheshire 882Fixed misleading use of the term "duplicate suppression" where it should have 883said "known answer suppression". (Duplicate answer suppression is something 884different, and duplicate question suppression is yet another thing, so the use 885of the completely vague term "duplicate suppression" was particularly bad.) 886 887Revision 1.52 2003/05/22 02:29:22 cheshire 888<rdar://problem/2984918> SendQueries needs to handle multihoming better 889Complete rewrite of SendQueries. Works much better now :-) 890 891Revision 1.51 2003/05/21 20:14:55 cheshire 892Fix comments and warnings 893 894Revision 1.50 2003/05/14 07:08:36 cheshire 895<rdar://problem/3159272> mDNSResponder should be smarter about reconfigurations 896Previously, when there was any network configuration change, mDNSResponder 897would tear down the entire list of active interfaces and start again. 898That was very disruptive, and caused the entire cache to be flushed, 899and caused lots of extra network traffic. Now it only removes interfaces 900that have really gone, and only adds new ones that weren't there before. 901 902Revision 1.49 2003/05/07 01:49:36 cheshire 903Remove "const" in ConstructServiceName prototype 904 905Revision 1.48 2003/05/07 00:18:44 cheshire 906Fix typo: "kDNSQClass_Mask" should be "kDNSClass_Mask" 907 908Revision 1.47 2003/05/06 00:00:46 cheshire 909<rdar://problem/3248914> Rationalize naming of domainname manipulation functions 910 911Revision 1.46 2003/04/30 20:39:09 cheshire 912Add comment 913 914Revision 1.45 2003/04/29 00:40:50 cheshire 915Fix compiler warnings 916 917Revision 1.44 2003/04/26 02:41:56 cheshire 918<rdar://problem/3241281> Change timenow from a local variable to a structure member 919 920Revision 1.43 2003/04/25 01:45:56 cheshire 921<rdar://problem/3240002> mDNS_RegisterNoSuchService needs to include a host name 922 923Revision 1.42 2003/04/15 20:58:31 jgraessl 924 925<rdar://problem/3229014> Added a hash to lookup records in the cache. 926 927Revision 1.41 2003/04/15 18:09:13 jgraessl 928 929<rdar://problem/3228892> 930Reviewed by: Stuart Cheshire 931Added code to keep track of when the next cache item will expire so we can 932call TidyRRCache only when necessary. 933 934Revision 1.40 2003/03/29 01:55:19 cheshire 935<rdar://problem/3212360> mDNSResponder sometimes suffers false self-conflicts when it sees its own packets 936Solution: Major cleanup of packet timing and conflict handling rules 937 938Revision 1.39 2003/03/27 03:30:55 cheshire 939<rdar://problem/3210018> Name conflicts not handled properly, resulting in memory corruption, and eventual crash 940Problem was that HostNameCallback() was calling mDNS_DeregisterInterface(), which is not safe in a callback 941Fixes: 9421. Make mDNS_DeregisterInterface() safe to call from a callback 9432. Make HostNameCallback() use mDNS_DeadvertiseInterface() instead 944 (it never really needed to deregister the interface at all) 945 946Revision 1.38 2003/03/15 04:40:36 cheshire 947Change type called "mDNSOpaqueID" to the more descriptive name "mDNSInterfaceID" 948 949Revision 1.37 2003/03/14 21:34:11 cheshire 950<rdar://problem/3176950> Can't setup and print to Lexmark PS printers via Airport Extreme 951Increase size of cache rdata from 512 to 768 952 953Revision 1.36 2003/03/05 03:38:35 cheshire 954<rdar://problem/3185731> Bogus error message in console: died or deallocated, but no record of client can be found! 955Fixed by leaving client in list after conflict, until client explicitly deallocates 956 957Revision 1.35 2003/02/21 02:47:54 cheshire 958<rdar://problem/3099194> mDNSResponder needs performance improvements 959Several places in the code were calling CacheRRActive(), which searched the entire 960question list every time, to see if this cache resource record answers any question. 961Instead, we now have a field "CRActiveQuestion" in the resource record structure 962 963Revision 1.34 2003/02/21 01:54:08 cheshire 964<rdar://problem/3099194> mDNSResponder needs performance improvements 965Switched to using new "mDNS_Execute" model (see "Implementer Notes.txt") 966 967Revision 1.33 2003/02/20 06:48:32 cheshire 968<rdar://problem/3169535> Xserve RAID needs to do interface-specific registrations 969Reviewed by: Josh Graessley, Bob Bradley 970 971Revision 1.32 2003/01/31 03:35:59 cheshire 972<rdar://problem/3147097> mDNSResponder sometimes fails to find the correct results 973When there were *two* active questions in the list, they were incorrectly 974finding *each other* and *both* being marked as duplicates of another question 975 976Revision 1.31 2003/01/29 02:46:37 cheshire 977Fix for IPv6: 978A physical interface is identified solely by its InterfaceID (not by IP and type). 979On a given InterfaceID, mDNSCore may send both v4 and v6 multicasts. 980In cases where the requested outbound protocol (v4 or v6) is not supported on 981that InterfaceID, the platform support layer should simply discard that packet. 982 983Revision 1.30 2003/01/29 01:47:08 cheshire 984Rename 'Active' to 'CRActive' or 'InterfaceActive' for improved clarity 985 986Revision 1.29 2003/01/28 05:23:43 cheshire 987<rdar://problem/3147097> mDNSResponder sometimes fails to find the correct results 988Add 'Active' flag for interfaces 989 990Revision 1.28 2003/01/28 01:35:56 cheshire 991Revise comment about ThisQInterval to reflect new semantics 992 993Revision 1.27 2003/01/13 23:49:42 jgraessl 994Merged changes for the following fixes in to top of tree: 995<rdar://problem/3086540> computer name changes not handled properly 996<rdar://problem/3124348> service name changes are not properly handled 997<rdar://problem/3124352> announcements sent in pairs, failing chattiness test 998 999Revision 1.26 2002/12/23 22:13:28 jgraessl 1000 1001Reviewed by: Stuart Cheshire 1002Initial IPv6 support for mDNSResponder. 1003 1004Revision 1.25 2002/09/21 20:44:49 zarzycki 1005Added APSL info 1006 1007Revision 1.24 2002/09/19 23:47:35 cheshire 1008Added mDNS_RegisterNoSuchService() function for assertion of non-existence 1009of a particular named service 1010 1011Revision 1.23 2002/09/19 21:25:34 cheshire 1012mDNS_snprintf() doesn't need to be in a separate file 1013 1014Revision 1.22 2002/09/19 04:20:43 cheshire 1015Remove high-ascii characters that confuse some systems 1016 1017Revision 1.21 2002/09/17 01:06:35 cheshire 1018Change mDNS_AdvertiseLocalAddresses to be a parameter to mDNS_Init() 1019 1020Revision 1.20 2002/09/16 18:41:41 cheshire 1021Merge in license terms from Quinn's copy, in preparation for Darwin release 1022 1023*/ 1024 1025#pragma ident "%Z%%M% %I% %E% SMI" 1026 1027#ifndef __mDNSClientAPI_h 1028#define __mDNSClientAPI_h 1029 1030#if defined(EFI32) || defined(EFI64) 1031// EFI doesn't have stdarg.h 1032#include "Tiano.h" 1033#define va_list VA_LIST 1034#define va_start(a, b) VA_START(a, b) 1035#define va_end(a) VA_END(a) 1036#define va_arg(a, b) VA_ARG(a, b) 1037#else 1038#include <stdarg.h> // stdarg.h is required for for va_list support for the mDNS_vsnprintf declaration 1039#endif 1040 1041#include "mDNSDebug.h" 1042 1043#ifdef __cplusplus 1044 extern "C" { 1045#endif 1046 1047// *************************************************************************** 1048// Function scope indicators 1049 1050// If you see "mDNSlocal" before a function name in a C file, it means the function is not callable outside this file 1051#ifndef mDNSlocal 1052#define mDNSlocal static 1053#endif 1054// If you see "mDNSexport" before a symbol in a C file, it means the symbol is exported for use by clients 1055// For every "mDNSexport" in a C file, there needs to be a corresponding "extern" declaration in some header file 1056// (When a C file #includes a header file, the "extern" declarations tell the compiler: 1057// "This symbol exists -- but not necessarily in this C file.") 1058#ifndef mDNSexport 1059#define mDNSexport 1060#endif 1061 1062// Explanation: These local/export markers are a little habit of mine for signaling the programmers' intentions. 1063// When "mDNSlocal" is just a synonym for "static", and "mDNSexport" is a complete no-op, you could be 1064// forgiven for asking what purpose they serve. The idea is that if you see "mDNSexport" in front of a 1065// function definition it means the programmer intended it to be exported and callable from other files 1066// in the project. If you see "mDNSlocal" in front of a function definition it means the programmer 1067// intended it to be private to that file. If you see neither in front of a function definition it 1068// means the programmer forgot (so you should work out which it is supposed to be, and fix it). 1069// Using "mDNSlocal" instead of "static" makes it easier to do a textual searches for one or the other. 1070// For example you can do a search for "static" to find if any functions declare any local variables as "static" 1071// (generally a bad idea unless it's also "const", because static storage usually risks being non-thread-safe) 1072// without the results being cluttered with hundreds of matches for functions declared static. 1073// - Stuart Cheshire 1074 1075// *************************************************************************** 1076// Structure packing macro 1077 1078// If we're not using GNUC, it's not fatal. 1079// Most compilers naturally pack the on-the-wire structures correctly anyway, so a plain "struct" is usually fine. 1080// In the event that structures are not packed correctly, mDNS_Init() will detect this and report an error, so the 1081// developer will know what's wrong, and can investigate what needs to be done on that compiler to provide proper packing. 1082#ifndef packedstruct 1083 #if ((__GNUC__ > 2) || ((__GNUC__ == 2) && (__GNUC_MINOR__ >= 9))) 1084 #define packedstruct struct __attribute__((__packed__)) 1085 #define packedunion union __attribute__((__packed__)) 1086 #else 1087 #define packedstruct struct 1088 #define packedunion union 1089 #endif 1090#endif 1091 1092// *************************************************************************** 1093#if 0 1094#pragma mark - DNS Resource Record class and type constants 1095#endif 1096 1097typedef enum // From RFC 1035 1098 { 1099 kDNSClass_IN = 1, // Internet 1100 kDNSClass_CS = 2, // CSNET 1101 kDNSClass_CH = 3, // CHAOS 1102 kDNSClass_HS = 4, // Hesiod 1103 kDNSClass_NONE = 254, // Used in DNS UPDATE [RFC 2136] 1104 1105 kDNSClass_Mask = 0x7FFF,// Multicast DNS uses the bottom 15 bits to identify the record class... 1106 kDNSClass_UniqueRRSet = 0x8000,// ... and the top bit indicates that all other cached records are now invalid 1107 1108 kDNSQClass_ANY = 255, // Not a DNS class, but a DNS query class, meaning "all classes" 1109 kDNSQClass_UnicastResponse = 0x8000 // Top bit set in a question means "unicast response acceptable" 1110 } DNS_ClassValues; 1111 1112typedef enum // From RFC 1035 1113 { 1114 kDNSType_A = 1, // 1 Address 1115 kDNSType_NS, // 2 Name Server 1116 kDNSType_MD, // 3 Mail Destination 1117 kDNSType_MF, // 4 Mail Forwarder 1118 kDNSType_CNAME, // 5 Canonical Name 1119 kDNSType_SOA, // 6 Start of Authority 1120 kDNSType_MB, // 7 Mailbox 1121 kDNSType_MG, // 8 Mail Group 1122 kDNSType_MR, // 9 Mail Rename 1123 kDNSType_NULL, // 10 NULL RR 1124 kDNSType_WKS, // 11 Well-known-service 1125 kDNSType_PTR, // 12 Domain name pointer 1126 kDNSType_HINFO, // 13 Host information 1127 kDNSType_MINFO, // 14 Mailbox information 1128 kDNSType_MX, // 15 Mail Exchanger 1129 kDNSType_TXT, // 16 Arbitrary text string 1130 1131 kDNSType_AAAA = 28, // 28 IPv6 address 1132 kDNSType_SRV = 33, // 33 Service record 1133 kDNSType_OPT = 41, // EDNS0 OPT record 1134 kDNSType_TSIG = 250, // 250 Transaction Signature 1135 1136 kDNSQType_ANY = 255 // Not a DNS type, but a DNS query type, meaning "all types" 1137 } DNS_TypeValues; 1138 1139// *************************************************************************** 1140#if 0 1141#pragma mark - Simple types 1142#endif 1143 1144// mDNS defines its own names for these common types to simplify portability across 1145// multiple platforms that may each have their own (different) names for these types. 1146typedef int mDNSBool; 1147typedef signed char mDNSs8; 1148typedef unsigned char mDNSu8; 1149typedef signed short mDNSs16; 1150typedef unsigned short mDNSu16; 1151 1152// <http://gcc.gnu.org/onlinedocs/gcc-3.3.3/cpp/Common-Predefined-Macros.html> says 1153// __LP64__ _LP64 1154// These macros are defined, with value 1, if (and only if) the compilation is 1155// for a target where long int and pointer both use 64-bits and int uses 32-bit. 1156// <http://www.intel.com/software/products/compilers/clin/docs/ug/lin1077.htm> says 1157// Macro Name __LP64__ Value 1 1158// A quick Google search for "defined(__LP64__)" OR "#ifdef __LP64__" gives 2590 hits and 1159// a search for "#if __LP64__" gives only 12, so I think we'll go with the majority and use defined() 1160#if defined(_ILP64) || defined(__ILP64__) 1161typedef signed int32 mDNSs32; 1162typedef unsigned int32 mDNSu32; 1163#elif defined(_LP64) || defined(__LP64__) 1164typedef signed int mDNSs32; 1165typedef unsigned int mDNSu32; 1166#else 1167typedef signed long mDNSs32; 1168typedef unsigned long mDNSu32; 1169//typedef signed int mDNSs32; 1170//typedef unsigned int mDNSu32; 1171#endif 1172 1173// To enforce useful type checking, we make mDNSInterfaceID be a pointer to a dummy struct 1174// This way, mDNSInterfaceIDs can be assigned, and compared with each other, but not with other types 1175// Declaring the type to be the typical generic "void *" would lack this type checking 1176typedef struct mDNSInterfaceID_dummystruct { void *dummy; } *mDNSInterfaceID; 1177 1178// These types are for opaque two- and four-byte identifiers. 1179// The "NotAnInteger" fields of the unions allow the value to be conveniently passed around in a 1180// register for the sake of efficiency, and compared for equality or inequality, but don't forget -- 1181// just because it is in a register doesn't mean it is an integer. Operations like greater than, 1182// less than, add, multiply, increment, decrement, etc., are undefined for opaque identifiers, 1183// and if you make the mistake of trying to do those using the NotAnInteger field, then you'll 1184// find you get code that doesn't work consistently on big-endian and little-endian machines. 1185typedef packedunion { mDNSu8 b[ 2]; mDNSu16 NotAnInteger; } mDNSOpaque16; 1186typedef packedunion { mDNSu8 b[ 4]; mDNSu32 NotAnInteger; } mDNSOpaque32; 1187typedef packedunion { mDNSu8 b[ 6]; mDNSu16 w[3]; mDNSu32 l[1]; } mDNSOpaque48; 1188typedef packedunion { mDNSu8 b[16]; mDNSu16 w[8]; mDNSu32 l[4]; } mDNSOpaque128; 1189 1190typedef mDNSOpaque16 mDNSIPPort; // An IP port is a two-byte opaque identifier (not an integer) 1191typedef mDNSOpaque32 mDNSv4Addr; // An IP address is a four-byte opaque identifier (not an integer) 1192typedef mDNSOpaque128 mDNSv6Addr; // An IPv6 address is a 16-byte opaque identifier (not an integer) 1193typedef mDNSOpaque48 mDNSEthAddr; // An Ethernet address is a six-byte opaque identifier (not an integer) 1194 1195enum 1196 { 1197 mDNSAddrType_None = 0, 1198 mDNSAddrType_IPv4 = 4, 1199 mDNSAddrType_IPv6 = 6, 1200 mDNSAddrType_Unknown = ~0 // Special marker value used in known answer list recording 1201 }; 1202 1203typedef struct 1204 { 1205 mDNSs32 type; 1206 union { mDNSv6Addr v6; mDNSv4Addr v4; } ip; 1207 } mDNSAddr; 1208 1209enum { mDNSfalse = 0, mDNStrue = 1 }; 1210 1211#define mDNSNULL 0L 1212 1213enum 1214 { 1215 mStatus_Waiting = 1, 1216 mStatus_NoError = 0, 1217 1218 // mDNS return values are in the range FFFE FF00 (-65792) to FFFE FFFF (-65537) 1219 // The top end of the range (FFFE FFFF) is used for error codes; 1220 // the bottom end of the range (FFFE FF00) is used for non-error values; 1221 1222 // Error codes: 1223 mStatus_UnknownErr = -65537, // First value: 0xFFFE FFFF 1224 mStatus_NoSuchNameErr = -65538, 1225 mStatus_NoMemoryErr = -65539, 1226 mStatus_BadParamErr = -65540, 1227 mStatus_BadReferenceErr = -65541, 1228 mStatus_BadStateErr = -65542, 1229 mStatus_BadFlagsErr = -65543, 1230 mStatus_UnsupportedErr = -65544, 1231 mStatus_NotInitializedErr = -65545, 1232 mStatus_NoCache = -65546, 1233 mStatus_AlreadyRegistered = -65547, 1234 mStatus_NameConflict = -65548, 1235 mStatus_Invalid = -65549, 1236 mStatus_Firewall = -65550, 1237 mStatus_Incompatible = -65551, 1238 mStatus_BadInterfaceErr = -65552, 1239 mStatus_Refused = -65553, 1240 mStatus_NoSuchRecord = -65554, 1241 mStatus_NoAuth = -65555, 1242 mStatus_NoSuchKey = -65556, 1243 mStatus_NATTraversal = -65557, 1244 mStatus_DoubleNAT = -65558, 1245 mStatus_BadTime = -65559, 1246 mStatus_BadSig = -65560, // while we define this per RFC 2845, BIND 9 returns Refused for bad/missing signatures 1247 mStatus_BadKey = -65561, 1248 mStatus_TransientErr = -65562, // transient failures, e.g. sending packets shortly after a network transition or wake from sleep 1249 // -65563 to -65786 currently unused; available for allocation 1250 1251 // tcp connection status 1252 mStatus_ConnPending = -65787, 1253 mStatus_ConnFailed = -65788, 1254 mStatus_ConnEstablished = -65789, 1255 1256 // Non-error values: 1257 mStatus_GrowCache = -65790, 1258 mStatus_ConfigChanged = -65791, 1259 mStatus_MemFree = -65792 // Last value: 0xFFFE FF00 1260 1261 // mStatus_MemFree is the last legal mDNS error code, at the end of the range allocated for mDNS 1262 }; 1263 1264typedef mDNSs32 mStatus; 1265 1266// RFC 1034/1035 specify that a domain label consists of a length byte plus up to 63 characters 1267#define MAX_DOMAIN_LABEL 63 1268typedef struct { mDNSu8 c[ 64]; } domainlabel; // One label: length byte and up to 63 characters 1269 1270// RFC 1034/1035 specify that a domain name, including length bytes, data bytes, and terminating zero, may be up to 255 bytes long 1271#define MAX_DOMAIN_NAME 255 1272typedef struct { mDNSu8 c[256]; } domainname; // Up to 255 bytes of length-prefixed domainlabels 1273 1274typedef struct { mDNSu8 c[256]; } UTF8str255; // Null-terminated C string 1275 1276// The longest legal textual form of a DNS name is 1005 bytes, including the C-string terminating NULL at the end. 1277// Explanation: 1278// When a native domainname object is converted to printable textual form using ConvertDomainNameToCString(), 1279// non-printing characters are represented in the conventional DNS way, as '\ddd', where ddd is a three-digit decimal number. 1280// The longest legal domain name is 255 bytes, in the form of four labels as shown below: 1281// Length byte, 63 data bytes, length byte, 63 data bytes, length byte, 63 data bytes, length byte, 61 data bytes, zero byte. 1282// Each label is encoded textually as characters followed by a trailing dot. 1283// If every character has to be represented as a four-byte escape sequence, then this makes the maximum textual form four labels 1284// plus the C-string terminating NULL as shown below: 1285// 63*4+1 + 63*4+1 + 63*4+1 + 61*4+1 + 1 = 1005. 1286// Note that MAX_ESCAPED_DOMAIN_LABEL is not normally used: If you're only decoding a single label, escaping is usually not required. 1287// It is for domain names, where dots are used as label separators, that proper escaping is vital. 1288#define MAX_ESCAPED_DOMAIN_LABEL 254 1289#define MAX_ESCAPED_DOMAIN_NAME 1005 1290 1291// Most records have a TTL of 75 minutes, so that their 80% cache-renewal query occurs once per hour. 1292// For records containing a hostname (in the name on the left, or in the rdata on the right), 1293// like A, AAAA, reverse-mapping PTR, and SRV, we use a two-minute TTL by default, because we don't want 1294// them to hang around for too long in the cache if the host in question crashes or otherwise goes away. 1295// Wide-area service discovery records have a very short TTL to avoid poluting intermediate caches with 1296// dynamic records. When discovered via Long Lived Queries (with change notifications), resource record 1297// TTLs can be safely ignored. 1298 1299#define kStandardTTL (3600UL * 100 / 80) 1300#define kHostNameTTL 120UL 1301#define kWideAreaTTL 3 1302 1303#define DefaultTTLforRRType(X) (((X) == kDNSType_A || (X) == kDNSType_AAAA || (X) == kDNSType_SRV) ? kHostNameTTL : kStandardTTL) 1304 1305// *************************************************************************** 1306#if 0 1307#pragma mark - DNS Message structures 1308#endif 1309 1310#define mDNS_numZones numQuestions 1311#define mDNS_numPrereqs numAnswers 1312#define mDNS_numUpdates numAuthorities 1313 1314typedef packedstruct 1315 { 1316 mDNSOpaque16 id; 1317 mDNSOpaque16 flags; 1318 mDNSu16 numQuestions; 1319 mDNSu16 numAnswers; 1320 mDNSu16 numAuthorities; 1321 mDNSu16 numAdditionals; 1322 } DNSMessageHeader; 1323 1324// We can send and receive packets up to 9000 bytes (Ethernet Jumbo Frame size, if that ever becomes widely used) 1325// However, in the normal case we try to limit packets to 1500 bytes so that we don't get IP fragmentation on standard Ethernet 1326// 40 (IPv6 header) + 8 (UDP header) + 12 (DNS message header) + 1440 (DNS message body) = 1500 total 1327#define AbsoluteMaxDNSMessageData 8940 1328#define NormalMaxDNSMessageData 1440 1329typedef packedstruct 1330 { 1331 DNSMessageHeader h; // Note: Size 12 bytes 1332 mDNSu8 data[AbsoluteMaxDNSMessageData]; // 40 (IPv6) + 8 (UDP) + 12 (DNS header) + 8940 (data) = 9000 1333 } DNSMessage; 1334 1335// *************************************************************************** 1336#if 0 1337#pragma mark - Resource Record structures 1338#endif 1339 1340// Authoritative Resource Records: 1341// There are four basic types: Shared, Advisory, Unique, Known Unique 1342 1343// * Shared Resource Records do not have to be unique 1344// -- Shared Resource Records are used for DNS-SD service PTRs 1345// -- It is okay for several hosts to have RRs with the same name but different RDATA 1346// -- We use a random delay on responses to reduce collisions when all the hosts respond to the same query 1347// -- These RRs typically have moderately high TTLs (e.g. one hour) 1348// -- These records are announced on startup and topology changes for the benefit of passive listeners 1349// -- These records send a goodbye packet when deregistering 1350// 1351// * Advisory Resource Records are like Shared Resource Records, except they don't send a goodbye packet 1352// 1353// * Unique Resource Records should be unique among hosts within any given mDNS scope 1354// -- The majority of Resource Records are of this type 1355// -- If two entities on the network have RRs with the same name but different RDATA, this is a conflict 1356// -- Responses may be sent immediately, because only one host should be responding to any particular query 1357// -- These RRs typically have low TTLs (e.g. a few minutes) 1358// -- On startup and after topology changes, a host issues queries to verify uniqueness 1359 1360// * Known Unique Resource Records are treated like Unique Resource Records, except that mDNS does 1361// not have to verify their uniqueness because this is already known by other means (e.g. the RR name 1362// is derived from the host's IP or Ethernet address, which is already known to be a unique identifier). 1363 1364// Summary of properties of different record types: 1365// Probe? Does this record type send probes before announcing? 1366// Conflict? Does this record type react if we observe an apparent conflict? 1367// Goodbye? Does this record type send a goodbye packet on departure? 1368// 1369// Probe? Conflict? Goodbye? Notes 1370// Unregistered Should not appear in any list (sanity check value) 1371// Shared No No Yes e.g. Service PTR record 1372// Deregistering No No Yes Shared record about to announce its departure and leave the list 1373// Advisory No No No 1374// Unique Yes Yes No Record intended to be unique -- will probe to verify 1375// Verified Yes Yes No Record has completed probing, and is verified unique 1376// KnownUnique No Yes No Record is assumed by other means to be unique 1377 1378// Valid lifecycle of a record: 1379// Unregistered -> Shared -> Deregistering -(goodbye)-> Unregistered 1380// Unregistered -> Advisory -> Unregistered 1381// Unregistered -> Unique -(probe)-> Verified -> Unregistered 1382// Unregistered -> KnownUnique -> Unregistered 1383 1384// Each Authoritative kDNSRecordType has only one bit set. This makes it easy to quickly see if a record 1385// is one of a particular set of types simply by performing the appropriate bitwise masking operation. 1386 1387// Cache Resource Records (received from the network): 1388// There are four basic types: Answer, Unique Answer, Additional, Unique Additional 1389// Bit 7 (the top bit) of kDNSRecordType is always set for Cache Resource Records; always clear for Authoritative Resource Records 1390// Bit 6 (value 0x40) is set for answer records; clear for additional records 1391// Bit 5 (value 0x20) is set for records received with the kDNSClass_UniqueRRSet 1392 1393enum 1394 { 1395 kDNSRecordTypeUnregistered = 0x00, // Not currently in any list 1396 kDNSRecordTypeDeregistering = 0x01, // Shared record about to announce its departure and leave the list 1397 1398 kDNSRecordTypeUnique = 0x02, // Will become a kDNSRecordTypeVerified when probing is complete 1399 1400 kDNSRecordTypeAdvisory = 0x04, // Like Shared, but no goodbye packet 1401 kDNSRecordTypeShared = 0x08, // Shared means record name does not have to be unique -- use random delay on responses 1402 1403 kDNSRecordTypeVerified = 0x10, // Unique means mDNS should check that name is unique (and then send immediate responses) 1404 kDNSRecordTypeKnownUnique = 0x20, // Known Unique means mDNS can assume name is unique without checking 1405 // For Dynamic Update records, Known Unique means the record must already exist on the server. 1406 kDNSRecordTypeUniqueMask = (kDNSRecordTypeUnique | kDNSRecordTypeVerified | kDNSRecordTypeKnownUnique), 1407 kDNSRecordTypeActiveMask = (kDNSRecordTypeAdvisory | kDNSRecordTypeShared | kDNSRecordTypeVerified | kDNSRecordTypeKnownUnique), 1408 1409 kDNSRecordTypePacketAdd = 0x80, // Received in the Additional Section of a DNS Response 1410 kDNSRecordTypePacketAddUnique = 0x90, // Received in the Additional Section of a DNS Response with kDNSClass_UniqueRRSet set 1411 kDNSRecordTypePacketAuth = 0xA0, // Received in the Authorities Section of a DNS Response 1412 kDNSRecordTypePacketAuthUnique = 0xB0, // Received in the Authorities Section of a DNS Response with kDNSClass_UniqueRRSet set 1413 kDNSRecordTypePacketAns = 0xC0, // Received in the Answer Section of a DNS Response 1414 kDNSRecordTypePacketAnsUnique = 0xD0, // Received in the Answer Section of a DNS Response with kDNSClass_UniqueRRSet set 1415 1416 kDNSRecordTypePacketAnsMask = 0x40, // True for PacketAns and PacketAnsUnique 1417 kDNSRecordTypePacketUniqueMask = 0x10 // True for PacketAddUnique, PacketAnsUnique, PacketAuthUnique 1418 }; 1419 1420typedef packedstruct { mDNSu16 priority; mDNSu16 weight; mDNSIPPort port; domainname target; } rdataSRV; 1421typedef packedstruct { mDNSu16 preference; domainname exchange; } rdataMX; 1422typedef packedstruct 1423 { 1424 domainname mname; 1425 domainname rname; 1426 mDNSs32 serial; // Modular counter; increases when zone changes 1427 mDNSu32 refresh; // Time in seconds that a slave waits after successful replication of the database before it attempts replication again 1428 mDNSu32 retry; // Time in seconds that a slave waits after an unsuccessful replication attempt before it attempts replication again 1429 mDNSu32 expire; // Time in seconds that a slave holds on to old data while replication attempts remain unsuccessful 1430 mDNSu32 min; // Nominally the minimum record TTL for this zone, in seconds; also used for negative caching. 1431 } rdataSOA; 1432 1433typedef packedstruct 1434 { 1435 mDNSu16 vers; 1436 mDNSu16 llqOp; 1437 mDNSu16 err; 1438 mDNSu8 id[8]; 1439 mDNSu32 lease; 1440 } LLQOptData; 1441 1442#define LLQ_OPTLEN ((3 * sizeof(mDNSu16)) + 8 + sizeof(mDNSu32)) 1443// Windows adds pad bytes to sizeof(LLQOptData). Use this macro when setting length fields or validating option rdata from 1444// off the wire. Use sizeof(LLQOptData) when dealing with structures (e.g. memcpy). Never memcpy between on-the-wire 1445// representation and a structure 1446 1447// NOTE: rdataOpt format may be repeated an arbitrary number of times in a single resource record 1448typedef packedstruct 1449 { 1450 mDNSu16 opt; 1451 mDNSu16 optlen; 1452 union { LLQOptData llq; mDNSu32 lease; } OptData; 1453 } rdataOpt; 1454 1455// StandardAuthRDSize is 264 (256+8), which is large enough to hold a maximum-sized SRV record 1456// MaximumRDSize is 8K the absolute maximum we support (at least for now) 1457#define StandardAuthRDSize 264 1458#define MaximumRDSize 8192 1459 1460// InlineCacheRDSize is 68 1461// Records received from the network with rdata this size or less have their rdata stored right in the CacheRecord object 1462// Records received from the network with rdata larger than this have additional storage allocated for the rdata 1463// A quick unscientific sample from a busy network at Apple with lots of machines revealed this: 1464// 1461 records in cache 1465// 292 were one-byte TXT records 1466// 136 were four-byte A records 1467// 184 were sixteen-byte AAAA records 1468// 780 were various PTR, TXT and SRV records from 12-64 bytes 1469// Only 69 records had rdata bigger than 64 bytes 1470// Note that since CacheRecord object and a CacheGroup object are allocated out of the same pool, it's sensible to 1471// have them both be the same size. Making one smaller without making the other smaller won't actually save any memory. 1472#define InlineCacheRDSize 68 1473 1474#define InlineCacheGroupNameSize 144 1475 1476typedef union 1477 { 1478 mDNSu8 data[StandardAuthRDSize]; 1479 mDNSv4Addr ipv4; // For 'A' record 1480 mDNSv6Addr ipv6; // For 'AAAA' record 1481 domainname name; // For PTR, NS, and CNAME records 1482 UTF8str255 txt; // For TXT record 1483 rdataSRV srv; // For SRV record 1484 rdataMX mx; // For MX record 1485 rdataSOA soa; // For SOA record 1486 rdataOpt opt; // For eDNS0 opt record 1487 } RDataBody; 1488 1489typedef struct 1490 { 1491 mDNSu16 MaxRDLength; // Amount of storage allocated for rdata (usually sizeof(RDataBody)) 1492 RDataBody u; 1493 } RData; 1494#define sizeofRDataHeader (sizeof(RData) - sizeof(RDataBody)) 1495 1496typedef struct AuthRecord_struct AuthRecord; 1497typedef struct CacheRecord_struct CacheRecord; 1498typedef struct CacheGroup_struct CacheGroup; 1499typedef struct DNSQuestion_struct DNSQuestion; 1500typedef struct mDNS_struct mDNS; 1501typedef struct mDNS_PlatformSupport_struct mDNS_PlatformSupport; 1502typedef struct NATTraversalInfo_struct NATTraversalInfo; 1503 1504// Note: Within an mDNSRecordCallback mDNS all API calls are legal except mDNS_Init(), mDNS_Close(), mDNS_Execute() 1505typedef void mDNSRecordCallback(mDNS *const m, AuthRecord *const rr, mStatus result); 1506 1507// Note: 1508// Restrictions: An mDNSRecordUpdateCallback may not make any mDNS API calls. 1509// The intent of this callback is to allow the client to free memory, if necessary. 1510// The internal data structures of the mDNS code may not be in a state where mDNS API calls may be made safely. 1511typedef void mDNSRecordUpdateCallback(mDNS *const m, AuthRecord *const rr, RData *OldRData); 1512 1513typedef struct 1514 { 1515 mDNSu8 RecordType; // See enum above 1516 mDNSInterfaceID InterfaceID; // Set if this RR is specific to one interface 1517 // For records received off the wire, InterfaceID is *always* set to the receiving interface 1518 // For our authoritative records, InterfaceID is usually zero, except for those few records 1519 // that are interface-specific (e.g. address records, especially linklocal addresses) 1520 domainname *name; 1521 mDNSu16 rrtype; 1522 mDNSu16 rrclass; 1523 mDNSu32 rroriginalttl; // In seconds 1524 mDNSu16 rdlength; // Size of the raw rdata, in bytes 1525 mDNSu16 rdestimate; // Upper bound on size of rdata after name compression 1526 mDNSu32 namehash; // Name-based (i.e. case-insensitive) hash of name 1527 mDNSu32 rdatahash; // For rdata containing domain name (e.g. PTR, SRV, CNAME etc.), case-insensitive name hash 1528 // else, for all other rdata, 32-bit hash of the raw rdata 1529 // Note: This requirement is important. Various routines like AddAdditionalsToResponseList(), 1530 // ReconfirmAntecedents(), etc., use rdatahash as a pre-flight check to see 1531 // whether it's worth doing a full SameDomainName() call. If the rdatahash 1532 // is not a correct case-insensitive name hash, they'll get false negatives. 1533 RData *rdata; // Pointer to storage for this rdata 1534 } ResourceRecord; 1535 1536// Unless otherwise noted, states may apply to either independent record registrations or service registrations 1537typedef enum 1538 { 1539 regState_FetchingZoneData = 1, // getting info - update not sent 1540 regState_Pending = 2, // update sent, reply not received 1541 regState_Registered = 3, // update sent, reply received 1542 regState_DeregPending = 4, // dereg sent, reply not received 1543 regState_DeregDeferred = 5, // dereg requested while in Pending state - send dereg AFTER registration is confirmed 1544 regState_Cancelled = 6, // update not sent, reg. cancelled by client 1545 regState_Unregistered = 8, // not in any list 1546 regState_Refresh = 9, // outstanding refresh (or target change) message 1547 regState_NATMap = 10, // establishing NAT port mapping or learning public address 1548 regState_UpdatePending = 11, // update in flight as result of mDNS_Update call 1549 regState_NoTarget = 12, // service registration pending registration of hostname (ServiceRegistrations only) 1550 regState_ExtraQueued = 13, // extra record to be registered upon completion of service registration (RecordRegistrations only) 1551 regState_NATError = 14 // unable to complete NAT traversal 1552 } regState_t; 1553 1554// context for both ServiceRecordSet and individual AuthRec structs 1555typedef struct 1556 { 1557 // registration/lease state 1558 regState_t state; 1559 mDNSBool lease; // dynamic update contains (should contain) lease option 1560 mDNSs32 expire; // expiration of lease (-1 for static) 1561 mDNSBool TestForSelfConflict; // on name conflict, check if we're just seeing our own orphaned records 1562 1563 // identifier to match update request and response 1564 mDNSOpaque16 id; 1565 1566 // server info 1567 domainname zone; // the zone that is updated 1568 mDNSAddr ns; // primary name server for the record's zone !!!KRS not technically correct to cache longer than TTL 1569 mDNSIPPort port; // port on which server accepts dynamic updates 1570 1571 // NAT traversal context 1572 NATTraversalInfo *NATinfo; // may be NULL 1573 1574 // state for deferred operations 1575 mDNSBool ClientCallbackDeferred; // invoke client callback on completion of pending operation(s) 1576 mStatus DeferredStatus; // status to deliver when above flag is set 1577 mDNSBool SRVUpdateDeferred; // do we need to change target or port once current operation completes? 1578 mDNSBool SRVChanged; // temporarily deregistered service because its SRV target or port changed 1579 1580 // uDNS_UpdateRecord support fields 1581 RData *OrigRData; mDNSu16 OrigRDLen; // previously registered, being deleted 1582 RData *InFlightRData; mDNSu16 InFlightRDLen; // currently being registered 1583 RData *QueuedRData; mDNSu16 QueuedRDLen; // if the client call Update while an update is in flight, we must finish the 1584 // pending operation (re-transmitting if necessary) THEN register the queued update 1585 mDNSRecordUpdateCallback *UpdateRDCallback; // client callback to free old rdata 1586 } uDNS_RegInfo; 1587 1588struct AuthRecord_struct 1589 { 1590 // For examples of how to set up this structure for use in mDNS_Register(), 1591 // see mDNS_AdvertiseInterface() or mDNS_RegisterService(). 1592 // Basically, resrec and persistent metadata need to be set up before calling mDNS_Register(). 1593 // mDNS_SetupResourceRecord() is avaliable as a helper routine to set up most fields to sensible default values for you 1594 1595 AuthRecord *next; // Next in list; first element of structure for efficiency reasons 1596 // Field Group 1: Common ResourceRecord fields 1597 ResourceRecord resrec; 1598 uDNS_RegInfo uDNS_info; 1599 1600 // Field Group 2: Persistent metadata for Authoritative Records 1601 AuthRecord *Additional1; // Recommended additional record to include in response 1602 AuthRecord *Additional2; // Another additional 1603 AuthRecord *DependentOn; // This record depends on another for its uniqueness checking 1604 AuthRecord *RRSet; // This unique record is part of an RRSet 1605 mDNSRecordCallback *RecordCallback; // Callback function to call for state changes, and to free memory asynchronously on deregistration 1606 void *RecordContext; // Context parameter for the callback function 1607 mDNSu8 HostTarget; // Set if the target of this record (PTR, CNAME, SRV, etc.) is our host name 1608 mDNSu8 AllowRemoteQuery; // Set if we allow hosts not on the local link to query this record 1609 mDNSu8 ForceMCast; // Set by client to advertise solely via multicast, even for apparently unicast names 1610 1611 // Field Group 3: Transient state for Authoritative Records 1612 mDNSu8 Acknowledged; // Set if we've given the success callback to the client 1613 mDNSu8 ProbeCount; // Number of probes remaining before this record is valid (kDNSRecordTypeUnique) 1614 mDNSu8 AnnounceCount; // Number of announcements remaining (kDNSRecordTypeShared) 1615 mDNSu8 RequireGoodbye; // Set if this RR has been announced on the wire and will require a goodbye packet 1616 mDNSu8 LocalAnswer; // Set if this RR has been delivered to LocalOnly questions 1617 mDNSu8 IncludeInProbe; // Set if this RR is being put into a probe right now 1618 mDNSInterfaceID ImmedAnswer; // Someone on this interface issued a query we need to answer (all-ones for all interfaces) 1619 mDNSu8 ImmedUnicast; // Set if we may send our response directly via unicast to the requester 1620#if MDNS_LOG_ANSWER_SUPPRESSION_TIMES 1621 mDNSs32 ImmedAnswerMarkTime; 1622#endif 1623 mDNSInterfaceID ImmedAdditional; // Hint that we might want to also send this record, just to be helpful 1624 mDNSInterfaceID SendRNow; // The interface this query is being sent on right now 1625 mDNSv4Addr v4Requester; // Recent v4 query for this record, or all-ones if more than one recent query 1626 mDNSv6Addr v6Requester; // Recent v6 query for this record, or all-ones if more than one recent query 1627 AuthRecord *NextResponse; // Link to the next element in the chain of responses to generate 1628 const mDNSu8 *NR_AnswerTo; // Set if this record was selected by virtue of being a direct answer to a question 1629 AuthRecord *NR_AdditionalTo; // Set if this record was selected by virtue of being additional to another 1630 mDNSs32 ThisAPInterval; // In platform time units: Current interval for announce/probe 1631 mDNSs32 AnnounceUntil; // In platform time units: Creation time + TTL 1632 mDNSs32 LastAPTime; // In platform time units: Last time we sent announcement/probe 1633 mDNSs32 LastMCTime; // Last time we multicast this record (used to guard against packet-storm attacks) 1634 mDNSInterfaceID LastMCInterface; // Interface this record was multicast on at the time LastMCTime was recorded 1635 RData *NewRData; // Set if we are updating this record with new rdata 1636 mDNSu16 newrdlength; // ... and the length of the new RData 1637 mDNSRecordUpdateCallback *UpdateCallback; 1638 mDNSu32 UpdateCredits; // Token-bucket rate limiting of excessive updates 1639 mDNSs32 NextUpdateCredit; // Time next token is added to bucket 1640 mDNSs32 UpdateBlocked; // Set if update delaying is in effect 1641 1642 domainname namestorage; 1643 RData rdatastorage; // Normally the storage is right here, except for oversized records 1644 // rdatastorage MUST be the last thing in the structure -- when using oversized AuthRecords, extra bytes 1645 // are appended after the end of the AuthRecord, logically augmenting the size of the rdatastorage 1646 // DO NOT ADD ANY MORE FIELDS HERE 1647 }; 1648 1649// Wrapper struct for Auth Records for higher-level code that cannot use the AuthRecord's ->next pointer field 1650typedef struct ARListElem 1651 { 1652 struct ARListElem *next; 1653 AuthRecord ar; // Note: Must be last struct in field to accomodate oversized AuthRecords 1654 } ARListElem; 1655 1656struct CacheGroup_struct // Header object for a list of CacheRecords with the same name 1657 { 1658 CacheGroup *next; // Next CacheGroup object in this hash table bucket 1659 mDNSu32 namehash; // Name-based (i.e. case insensitive) hash of name 1660 CacheRecord *members; // List of CacheRecords with this same name 1661 CacheRecord **rrcache_tail; // Tail end of that list 1662 domainname *name; // Common name for all CacheRecords in this list 1663 mDNSu8 namestorage[InlineCacheGroupNameSize]; 1664 }; 1665 1666struct CacheRecord_struct 1667 { 1668 CacheRecord *next; // Next in list; first element of structure for efficiency reasons 1669 ResourceRecord resrec; 1670 1671 // Transient state for Cache Records 1672 CacheRecord *NextInKAList; // Link to the next element in the chain of known answers to send 1673 mDNSs32 TimeRcvd; // In platform time units 1674 mDNSs32 DelayDelivery; // Set if we want to defer delivery of this answer to local clients 1675 mDNSs32 NextRequiredQuery; // In platform time units 1676 mDNSs32 LastUsed; // In platform time units 1677 DNSQuestion *CRActiveQuestion; // Points to an active question referencing this answer 1678 mDNSu32 UnansweredQueries; // Number of times we've issued a query for this record without getting an answer 1679 mDNSs32 LastUnansweredTime; // In platform time units; last time we incremented UnansweredQueries 1680 mDNSu32 MPUnansweredQ; // Multi-packet query handling: Number of times we've seen a query for this record 1681 mDNSs32 MPLastUnansweredQT; // Multi-packet query handling: Last time we incremented MPUnansweredQ 1682 mDNSu32 MPUnansweredKA; // Multi-packet query handling: Number of times we've seen this record in a KA list 1683 mDNSBool MPExpectingKA; // Multi-packet query handling: Set when we increment MPUnansweredQ; allows one KA 1684 CacheRecord *NextInCFList; // Set if this is in the list of records we just received with the cache flush bit set 1685 1686 struct { mDNSu16 MaxRDLength; mDNSu8 data[InlineCacheRDSize]; } rdatastorage; // Storage for small records is right here 1687 }; 1688 1689// Storage sufficient to hold either a CacheGroup header or a CacheRecord 1690typedef union CacheEntity_union CacheEntity; 1691union CacheEntity_union { CacheEntity *next; CacheGroup cg; CacheRecord cr; }; 1692 1693typedef struct 1694 { 1695 CacheRecord r; 1696 mDNSu8 _extradata[MaximumRDSize-InlineCacheRDSize]; // Glue on the necessary number of extra bytes 1697 domainname namestorage; // Needs to go *after* the extra rdata bytes 1698 } LargeCacheRecord; 1699 1700typedef struct uDNS_HostnameInfo 1701 { 1702 struct uDNS_HostnameInfo *next; 1703 domainname fqdn; 1704 AuthRecord *arv4; // registered IPv4 address record 1705 AuthRecord *arv6; // registered IPv6 address record 1706 mDNSRecordCallback *StatusCallback; // callback to deliver success or error code to client layer 1707 const void *StatusContext; // Client Context 1708 } uDNS_HostnameInfo; 1709 1710enum 1711 { 1712 DNSServer_Untested = 0, 1713 DNSServer_Failed = 1, 1714 DNSServer_Passed = 2 1715 }; 1716 1717typedef struct DNSServer 1718 { 1719 struct DNSServer *next; 1720 mDNSAddr addr; 1721 mDNSBool del; // Set when we're planning to delete this from the list 1722 mDNSu32 teststate; // Have we sent bug-detection query to this server? 1723 domainname domain; // name->server matching for "split dns" 1724 } DNSServer; 1725 1726typedef struct NetworkInterfaceInfo_struct NetworkInterfaceInfo; 1727 1728// A NetworkInterfaceInfo_struct serves two purposes: 1729// 1. It holds the address, PTR and HINFO records to advertise a given IP address on a given physical interface 1730// 2. It tells mDNSCore which physical interfaces are available; each physical interface has its own unique InterfaceID. 1731// Since there may be multiple IP addresses on a single physical interface, 1732// there may be multiple NetworkInterfaceInfo_structs with the same InterfaceID. 1733// In this case, to avoid sending the same packet n times, when there's more than one 1734// struct with the same InterfaceID, mDNSCore picks one member of the set to be the 1735// active representative of the set; all others have the 'InterfaceActive' flag unset. 1736 1737struct NetworkInterfaceInfo_struct 1738 { 1739 // Internal state fields. These are used internally by mDNSCore; the client layer needn't be concerned with them. 1740 NetworkInterfaceInfo *next; 1741 1742 mDNSBool InterfaceActive; // Set if interface is sending & receiving packets (see comment above) 1743 mDNSBool IPv4Available; // If InterfaceActive, set if v4 available on this InterfaceID 1744 mDNSBool IPv6Available; // If InterfaceActive, set if v6 available on this InterfaceID 1745 1746 // Standard AuthRecords that every Responder host should have (one per active IP address) 1747 AuthRecord RR_A; // 'A' or 'AAAA' (address) record for our ".local" name 1748 AuthRecord RR_PTR; // PTR (reverse lookup) record 1749 AuthRecord RR_HINFO; 1750 1751 // Client API fields: The client must set up these fields *before* calling mDNS_RegisterInterface() 1752 mDNSInterfaceID InterfaceID; // Identifies physical interface; MUST NOT be 0, -1, or -2 1753 mDNSAddr ip; // The IPv4 or IPv6 address to advertise 1754 mDNSAddr mask; 1755 char ifname[64]; // Windows uses a GUID string for the interface name, which doesn't fit in 16 bytes 1756 mDNSBool Advertise; // False if you are only searching on this interface 1757 mDNSBool McastTxRx; // Send/Receive multicast on this { InterfaceID, address family } ? 1758 }; 1759 1760typedef struct ExtraResourceRecord_struct ExtraResourceRecord; 1761struct ExtraResourceRecord_struct 1762 { 1763 ExtraResourceRecord *next; 1764 mDNSu32 ClientID; // Opaque ID field to be used by client to map an AddRecord call to a set of Extra records 1765 AuthRecord r; 1766 // Note: Add any additional fields *before* the AuthRecord in this structure, not at the end. 1767 // In some cases clients can allocate larger chunks of memory and set r->rdata->MaxRDLength to indicate 1768 // that this extra memory is available, which would result in any fields after the AuthRecord getting smashed 1769 }; 1770 1771// Note: Within an mDNSServiceCallback mDNS all API calls are legal except mDNS_Init(), mDNS_Close(), mDNS_Execute() 1772typedef struct ServiceRecordSet_struct ServiceRecordSet; 1773typedef void mDNSServiceCallback(mDNS *const m, ServiceRecordSet *const sr, mStatus result); 1774struct ServiceRecordSet_struct 1775 { 1776 // Internal state fields. These are used internally by mDNSCore; the client layer needn't be concerned with them. 1777 // No fields need to be set up by the client prior to calling mDNS_RegisterService(); 1778 // all required data is passed as parameters to that function. 1779 ServiceRecordSet *next; 1780 uDNS_RegInfo uDNS_info; 1781 mDNSServiceCallback *ServiceCallback; 1782 void *ServiceContext; 1783 ExtraResourceRecord *Extras; // Optional list of extra AuthRecords attached to this service registration 1784 mDNSu32 NumSubTypes; 1785 AuthRecord *SubTypes; 1786 mDNSBool Conflict; // Set if this record set was forcibly deregistered because of a conflict 1787 domainname Host; // Set if this service record does not use the standard target host name 1788 AuthRecord RR_ADV; // e.g. _services._dns-sd._udp.local. PTR _printer._tcp.local. 1789 AuthRecord RR_PTR; // e.g. _printer._tcp.local. PTR Name._printer._tcp.local. 1790 AuthRecord RR_SRV; // e.g. Name._printer._tcp.local. SRV 0 0 port target 1791 AuthRecord RR_TXT; // e.g. Name._printer._tcp.local. TXT PrintQueueName 1792 // Don't add any fields after AuthRecord RR_TXT. 1793 // This is where the implicit extra space goes if we allocate a ServiceRecordSet containing an oversized RR_TXT record 1794 }; 1795 1796// *************************************************************************** 1797#if 0 1798#pragma mark - Question structures 1799#endif 1800 1801// We record the last eight instances of each duplicate query 1802// This gives us v4/v6 on each of Ethernet/AirPort and Firewire, and two free slots "for future expansion" 1803// If the host has more active interfaces that this it is not fatal -- duplicate question suppression will degrade gracefully. 1804// Since we will still remember the last eight, the busiest interfaces will still get the effective duplicate question suppression. 1805#define DupSuppressInfoSize 8 1806 1807typedef struct 1808 { 1809 mDNSs32 Time; 1810 mDNSInterfaceID InterfaceID; 1811 mDNSs32 Type; // v4 or v6? 1812 } DupSuppressInfo; 1813 1814typedef enum 1815 { 1816 // Setup states 1817 LLQ_UnInit = 0, 1818 LLQ_GetZoneInfo = 1, 1819 LLQ_InitialRequest = 2, 1820 LLQ_SecondaryRequest = 3, 1821 LLQ_Refresh = 4, 1822 LLQ_Retry = 5, 1823 LLQ_Established = 6, 1824 LLQ_Suspended = 7, 1825 LLQ_SuspendDeferred = 8, // suspend once we get zone info 1826 LLQ_SuspendedPoll = 9, // suspended from polling state 1827 LLQ_NatMapWait = 10, 1828 1829 // Established/error states 1830 LLQ_Static = 16, 1831 LLQ_Poll = 17, 1832 LLQ_Error = 18, 1833 LLQ_Cancelled = 19 1834 } LLQ_State; 1835 1836typedef struct 1837 { 1838 LLQ_State state; 1839 mDNSAddr servAddr; 1840 mDNSIPPort servPort; 1841 DNSQuestion *question; 1842 mDNSu32 origLease; // seconds (relative) 1843 mDNSs32 retry; // ticks (absolute) 1844 mDNSs32 expire; // ticks (absolute) 1845 mDNSs16 ntries; 1846 mDNSu8 id[8]; 1847 mDNSBool deriveRemovesOnResume; 1848 mDNSBool NATMap; // does this LLQ use the global LLQ NAT mapping? 1849 } LLQ_Info; 1850 1851// LLQ constants 1852#define kDNSOpt_LLQ 1 1853#define kDNSOpt_Lease 2 1854#define kLLQ_Vers 1 1855#define kLLQ_DefLease 7200 // 2 hours 1856#define kLLQ_MAX_TRIES 3 // retry an operation 3 times max 1857#define kLLQ_INIT_RESEND 2 // resend an un-ack'd packet after 2 seconds, then double for each additional 1858#define kLLQ_DEF_RETRY 1800 // retry a failed operation after 30 minutes 1859// LLQ Operation Codes 1860#define kLLQOp_Setup 1 1861#define kLLQOp_Refresh 2 1862#define kLLQOp_Event 3 1863 1864#define LLQ_OPT_RDLEN ((2 * sizeof(mDNSu16)) + LLQ_OPTLEN) 1865#define LEASE_OPT_RDLEN (2 * sizeof(mDNSu16)) + sizeof(mDNSs32) 1866 1867// LLQ Errror Codes 1868enum 1869 { 1870 LLQErr_NoError = 0, 1871 LLQErr_ServFull = 1, 1872 LLQErr_Static = 2, 1873 LLQErr_FormErr = 3, 1874 LLQErr_NoSuchLLQ = 4, 1875 LLQErr_BadVers = 5, 1876 LLQErr_UnknownErr = 6 1877 }; 1878 1879typedef void (*InternalResponseHndlr)(mDNS *const m, DNSMessage *msg, const mDNSu8 *end, DNSQuestion *question, void *internalContext); 1880typedef struct 1881 { 1882 mDNSOpaque16 id; 1883 mDNSBool internal; 1884 InternalResponseHndlr responseCallback; // NULL if internal field is false 1885 LLQ_Info *llq; // NULL for 1-shot queries 1886 mDNSBool Answered; // have we received an answer (including NXDOMAIN) for this question? 1887 CacheRecord *knownAnswers; 1888 mDNSs32 RestartTime; // Mark when we restart a suspended query 1889 void *context; 1890 } uDNS_QuestionInfo; 1891 1892// Note: Within an mDNSQuestionCallback mDNS all API calls are legal except mDNS_Init(), mDNS_Close(), mDNS_Execute() 1893typedef void mDNSQuestionCallback(mDNS *const m, DNSQuestion *question, const ResourceRecord *const answer, mDNSBool AddRecord); 1894struct DNSQuestion_struct 1895 { 1896 // Internal state fields. These are used internally by mDNSCore; the client layer needn't be concerned with them. 1897 DNSQuestion *next; 1898 mDNSu32 qnamehash; 1899 mDNSs32 DelayAnswering; // Set if we want to defer answering this question until the cache settles 1900 mDNSs32 LastQTime; // Last scheduled transmission of this Q on *all* applicable interfaces 1901 mDNSs32 ThisQInterval; // LastQTime + ThisQInterval is the next scheduled transmission of this Q 1902 // ThisQInterval > 0 for an active question; 1903 // ThisQInterval = 0 for a suspended question that's still in the list 1904 // ThisQInterval = -1 for a cancelled question that's been removed from the list 1905 mDNSs32 LastAnswerPktNum; // The sequence number of the last response packet containing an answer to this Q 1906 mDNSu32 RecentAnswerPkts; // Number of answers since the last time we sent this query 1907 mDNSu32 CurrentAnswers; // Number of records currently in the cache that answer this question 1908 mDNSu32 LargeAnswers; // Number of answers with rdata > 1024 bytes 1909 mDNSu32 UniqueAnswers; // Number of answers received with kDNSClass_UniqueRRSet bit set 1910 mDNSInterfaceID FlappingInterface;// Set when an interface goes away, to flag if removes are delivered for this Q 1911 DNSQuestion *DuplicateOf; 1912 DNSQuestion *NextInDQList; 1913 DupSuppressInfo DupSuppress[DupSuppressInfoSize]; 1914 mDNSInterfaceID SendQNow; // The interface this query is being sent on right now 1915 mDNSBool SendOnAll; // Set if we're sending this question on all active interfaces 1916 mDNSu32 RequestUnicast; // Non-zero if we want to send query with kDNSQClass_UnicastResponse bit set 1917 mDNSs32 LastQTxTime; // Last time this Q was sent on one (but not necessarily all) interfaces 1918 uDNS_QuestionInfo uDNS_info; 1919 1920 // Client API fields: The client must set up these fields *before* calling mDNS_StartQuery() 1921 mDNSInterfaceID InterfaceID; // Non-zero if you want to issue queries only on a single specific IP interface 1922 mDNSAddr Target; // Non-zero if you want to direct queries to a specific unicast target address 1923 mDNSIPPort TargetPort; // Must be set if Target is set 1924 mDNSOpaque16 TargetQID; // Must be set if Target is set 1925 domainname qname; 1926 mDNSu16 qtype; 1927 mDNSu16 qclass; 1928 mDNSBool LongLived; // Set by client for calls to mDNS_StartQuery to indicate LLQs to unicast layer. 1929 mDNSBool ExpectUnique; // Set by client if it's expecting unique RR(s) for this question, not shared RRs 1930 mDNSBool ForceMCast; // Set by client to force mDNS query, even for apparently uDNS names 1931 mDNSBool ReturnCNAME; // Set by client to request callbacks for intermediate CNAME records 1932 mDNSQuestionCallback *QuestionCallback; 1933 void *QuestionContext; 1934 }; 1935 1936typedef struct 1937 { 1938 // Client API fields: The client must set up name and InterfaceID *before* calling mDNS_StartResolveService() 1939 // When the callback is invoked, ip, port, TXTlen and TXTinfo will have been filled in with the results learned from the network. 1940 domainname name; 1941 mDNSInterfaceID InterfaceID; // ID of the interface the response was received on 1942 mDNSAddr ip; // Remote (destination) IP address where this service can be accessed 1943 mDNSIPPort port; // Port where this service can be accessed 1944 mDNSu16 TXTlen; 1945 mDNSu8 TXTinfo[2048]; // Additional demultiplexing information (e.g. LPR queue name) 1946 } ServiceInfo; 1947 1948// Note: Within an mDNSServiceInfoQueryCallback mDNS all API calls are legal except mDNS_Init(), mDNS_Close(), mDNS_Execute() 1949typedef struct ServiceInfoQuery_struct ServiceInfoQuery; 1950typedef void mDNSServiceInfoQueryCallback(mDNS *const m, ServiceInfoQuery *query); 1951struct ServiceInfoQuery_struct 1952 { 1953 // Internal state fields. These are used internally by mDNSCore; the client layer needn't be concerned with them. 1954 // No fields need to be set up by the client prior to calling mDNS_StartResolveService(); 1955 // all required data is passed as parameters to that function. 1956 // The ServiceInfoQuery structure memory is working storage for mDNSCore to discover the requested information 1957 // and place it in the ServiceInfo structure. After the client has called mDNS_StopResolveService(), it may 1958 // dispose of the ServiceInfoQuery structure while retaining the results in the ServiceInfo structure. 1959 DNSQuestion qSRV; 1960 DNSQuestion qTXT; 1961 DNSQuestion qAv4; 1962 DNSQuestion qAv6; 1963 mDNSu8 GotSRV; 1964 mDNSu8 GotTXT; 1965 mDNSu8 GotADD; 1966 mDNSu32 Answers; 1967 ServiceInfo *info; 1968 mDNSServiceInfoQueryCallback *ServiceInfoQueryCallback; 1969 void *ServiceInfoQueryContext; 1970 }; 1971 1972// *************************************************************************** 1973#if 0 1974#pragma mark - NAT Traversal structures and constants 1975#endif 1976 1977#define NATMAP_INIT_RETRY (mDNSPlatformOneSecond / 4) // start at 250ms w/ exponential decay 1978#define NATMAP_MAX_RETRY mDNSPlatformOneSecond // back off to once per second 1979#define NATMAP_MAX_TRIES 3 // for max 3 tries 1980#define NATMAP_DEFAULT_LEASE (60 * 60) // lease life in seconds 1981#define NATMAP_VERS 0 1982#define NATMAP_RESPONSE_MASK 0x80 1983 1984typedef enum 1985 { 1986 NATOp_AddrRequest = 0, 1987 NATOp_MapUDP = 1, 1988 NATOp_MapTCP = 2 1989 } NATOp_t; 1990 1991enum 1992 { 1993 NATErr_None = 0, 1994 NATErr_Vers = 1, 1995 NATErr_Refused = 2, 1996 NATErr_NetFail = 3, 1997 NATErr_Res = 4, 1998 NATErr_Opcode = 5 1999 }; 2000 2001typedef mDNSu16 NATErr_t; 2002 2003typedef enum 2004 { 2005 NATState_Init = 0, 2006 NATState_Request = 1, 2007 NATState_Established = 2, 2008 NATState_Legacy = 3, 2009 NATState_Error = 4, 2010 NATState_Refresh = 5, 2011 NATState_Deleted = 6 2012 } NATState_t; 2013// Note: we have no explicit "cancelled" state, where a service/interface is deregistered while we 2014 // have an outstanding NAT request. This is conveyed by the "reg" pointer being set to NULL 2015 2016typedef packedstruct 2017 { 2018 mDNSu8 vers; 2019 mDNSu8 opcode; 2020 } NATAddrRequest; 2021 2022typedef packedstruct 2023 { 2024 mDNSu8 vers; 2025 mDNSu8 opcode; 2026 mDNSOpaque16 err; 2027 mDNSOpaque32 uptime; 2028 mDNSv4Addr PubAddr; 2029 } NATAddrReply; 2030 2031typedef packedstruct 2032 { 2033 mDNSu8 vers; 2034 mDNSu8 opcode; 2035 mDNSOpaque16 unused; 2036 mDNSIPPort priv; 2037 mDNSIPPort pub; 2038 mDNSOpaque32 lease; 2039 } NATPortMapRequest; 2040 2041typedef packedstruct 2042 { 2043 mDNSu8 vers; 2044 mDNSu8 opcode; 2045 mDNSOpaque16 err; 2046 mDNSOpaque32 uptime; 2047 mDNSIPPort priv; 2048 mDNSIPPort pub; 2049 mDNSOpaque32 lease; 2050 } NATPortMapReply; 2051 2052// Pass NULL for pkt on error (including timeout) 2053typedef mDNSBool (*NATResponseHndlr)(NATTraversalInfo *n, mDNS *m, mDNSu8 *pkt, mDNSu16 len); 2054 2055struct NATTraversalInfo_struct 2056 { 2057 NATOp_t op; 2058 NATResponseHndlr ReceiveResponse; 2059 union { AuthRecord *RecordRegistration; ServiceRecordSet *ServiceRegistration; } reg; 2060 mDNSAddr Router; 2061 mDNSIPPort PublicPort; 2062 union { NATAddrRequest AddrReq; NATPortMapRequest PortReq; } request; 2063 mDNSs32 retry; // absolute time when we retry 2064 mDNSs32 RetryInterval; // delta between time sent and retry 2065 int ntries; 2066 NATState_t state; 2067 NATTraversalInfo *next; 2068 }; 2069 2070// *************************************************************************** 2071#if 0 2072#pragma mark - Main mDNS object, used to hold all the mDNS state 2073#endif 2074 2075typedef void mDNSCallback(mDNS *const m, mStatus result); 2076 2077#define CACHE_HASH_SLOTS 499 2078 2079enum 2080 { 2081 mDNS_KnownBug_PhantomInterfaces = 1 2082 }; 2083 2084typedef struct 2085 { 2086 mDNSs32 nextevent; 2087 DNSQuestion *ActiveQueries; //!!!KRS this should be a hashtable (hash on messageID) 2088 DNSQuestion *CurrentQuery; // pointer to ActiveQueries list being examined in a loop. Functions that remove 2089 // elements from the ActiveQueries list must update this pointer (if non-NULL) as necessary. 2090 //!!!KRS do the same for registration lists 2091 ServiceRecordSet *ServiceRegistrations; 2092 AuthRecord *RecordRegistrations; 2093 NATTraversalInfo *NATTraversals; 2094 mDNSu16 NextMessageID; 2095 DNSServer *Servers; // list of DNS servers 2096 mDNSAddr Router; 2097 mDNSAddr AdvertisedV4; // IPv4 address pointed to by hostname 2098 mDNSAddr MappedV4; // Cache of public address if PrimaryIP is behind a NAT 2099 mDNSAddr AdvertisedV6; // IPv6 address pointed to by hostname 2100 NATTraversalInfo *LLQNatInfo; // Nat port mapping to receive LLQ events 2101 domainname ServiceRegDomain; // (going away w/ multi-user support) 2102 struct uDNS_AuthInfo *AuthInfoList; // list of domains requiring authentication for updates. 2103 uDNS_HostnameInfo *Hostnames; // List of registered hostnames + hostname metadata 2104 DNSQuestion ReverseMap; // Reverse-map query to find static hostname for service target 2105 mDNSBool ReverseMapActive; // Is above query active? 2106 domainname StaticHostname; // Current answer to reverse-map query (above) 2107 mDNSBool DelaySRVUpdate; // Delay SRV target/port update to avoid "flap" 2108 mDNSs32 NextSRVUpdate; // Time to perform delayed update 2109 } uDNS_GlobalInfo; 2110 2111struct mDNS_struct 2112 { 2113 // Internal state fields. These hold the main internal state of mDNSCore; 2114 // the client layer needn't be concerned with them. 2115 // No fields need to be set up by the client prior to calling mDNS_Init(); 2116 // all required data is passed as parameters to that function. 2117 2118 mDNS_PlatformSupport *p; // Pointer to platform-specific data of indeterminite size 2119 mDNSu32 KnownBugs; 2120 mDNSBool CanReceiveUnicastOn5353; 2121 mDNSBool AdvertiseLocalAddresses; 2122 mStatus mDNSPlatformStatus; 2123 mDNSIPPort UnicastPort4; 2124 mDNSIPPort UnicastPort6; 2125 mDNSCallback *MainCallback; 2126 void *MainContext; 2127 2128 // For debugging: To catch and report locking failures 2129 mDNSu32 mDNS_busy; // Incremented between mDNS_Lock/mDNS_Unlock section 2130 mDNSu32 mDNS_reentrancy; // Incremented when calling a client callback 2131 mDNSu8 mDNS_shutdown; // Set when we're shutting down, allows us to skip some unnecessary steps 2132 mDNSu8 lock_rrcache; // For debugging: Set at times when these lists may not be modified 2133 mDNSu8 lock_Questions; 2134 mDNSu8 lock_Records; 2135 #define MaxMsg 120 2136 char MsgBuffer[MaxMsg]; // Temp storage used while building error log messages 2137 2138 // Task Scheduling variables 2139 mDNSs32 timenow_adjust; // Correction applied if we ever discover time went backwards 2140 mDNSs32 timenow; // The time that this particular activation of the mDNS code started 2141 mDNSs32 timenow_last; // The time the last time we ran 2142 mDNSs32 NextScheduledEvent; // Derived from values below 2143 mDNSs32 SuppressSending; // Don't send *any* packets during this time 2144 mDNSs32 NextCacheCheck; // Next time to refresh cache record before it expires 2145 mDNSs32 NextScheduledQuery; // Next time to send query in its exponential backoff sequence 2146 mDNSs32 NextScheduledProbe; // Next time to probe for new authoritative record 2147 mDNSs32 NextScheduledResponse; // Next time to send authoritative record(s) in responses 2148 mDNSs32 ExpectUnicastResponse; // Set when we send a query with the kDNSQClass_UnicastResponse bit set 2149 mDNSs32 RandomQueryDelay; // For de-synchronization of query packets on the wire 2150 mDNSu32 RandomReconfirmDelay; // For de-synchronization of reconfirmation queries on the wire 2151 mDNSs32 PktNum; // Unique sequence number assigned to each received packet 2152 mDNSBool SendDeregistrations; // Set if we need to send deregistrations (immediately) 2153 mDNSBool SendImmediateAnswers; // Set if we need to send answers (immediately -- or as soon as SuppressSending clears) 2154 mDNSBool SleepState; // Set if we're sleeping (send no more packets) 2155 2156 // These fields only required for mDNS Searcher... 2157 DNSQuestion *Questions; // List of all registered questions, active and inactive 2158 DNSQuestion *NewQuestions; // Fresh questions not yet answered from cache 2159 DNSQuestion *CurrentQuestion; // Next question about to be examined in AnswerLocalQuestions() 2160 DNSQuestion *LocalOnlyQuestions; // Questions with InterfaceID set to mDNSInterface_LocalOnly 2161 DNSQuestion *NewLocalOnlyQuestions; // Fresh local-only questions not yet answered 2162 mDNSu32 rrcache_size; // Total number of available cache entries 2163 mDNSu32 rrcache_totalused; // Number of cache entries currently occupied 2164 mDNSu32 rrcache_active; // Number of cache entries currently occupied by records that answer active questions 2165 mDNSu32 rrcache_report; 2166 CacheEntity *rrcache_free; 2167 CacheGroup *rrcache_hash[CACHE_HASH_SLOTS]; 2168 2169 // Fields below only required for mDNS Responder... 2170 domainlabel nicelabel; // Rich text label encoded using canonically precomposed UTF-8 2171 domainlabel hostlabel; // Conforms to RFC 1034 "letter-digit-hyphen" ARPANET host name rules 2172 domainname MulticastHostname; // Fully Qualified "dot-local" Host Name, e.g. "Foo.local." 2173 UTF8str255 HIHardware; 2174 UTF8str255 HISoftware; 2175 AuthRecord *ResourceRecords; 2176 AuthRecord *DuplicateRecords; // Records currently 'on hold' because they are duplicates of existing records 2177 AuthRecord *NewLocalRecords; // Fresh local-only records not yet delivered to local-only questions 2178 AuthRecord *CurrentRecord; // Next AuthRecord about to be examined 2179 NetworkInterfaceInfo *HostInterfaces; 2180 mDNSs32 ProbeFailTime; 2181 mDNSu32 NumFailedProbes; 2182 mDNSs32 SuppressProbes; 2183 2184 // unicast-specific data 2185 uDNS_GlobalInfo uDNS_info; 2186 mDNSs32 SuppressStdPort53Queries; // Wait before allowing the next standard unicast query to the user's configured DNS server 2187 2188 // Fixed storage, to avoid creating large objects on the stack 2189 DNSMessage imsg; // Incoming message received from wire 2190 DNSMessage omsg; // Outgoing message we're building 2191 LargeCacheRecord rec; // Resource Record extracted from received message 2192 }; 2193 2194#define FORALL_CACHERECORDS(SLOT,CG,CR) \ 2195 for ((SLOT) = 0; (SLOT) < CACHE_HASH_SLOTS; (SLOT)++) \ 2196 for((CG)=m->rrcache_hash[(SLOT)]; (CG); (CG)=(CG)->next) \ 2197 for ((CR) = (CG)->members; (CR); (CR)=(CR)->next) 2198 2199// *************************************************************************** 2200#if 0 2201#pragma mark - Useful Static Constants 2202#endif 2203 2204extern const mDNSIPPort zeroIPPort; 2205extern const mDNSv4Addr zerov4Addr; 2206extern const mDNSv6Addr zerov6Addr; 2207extern const mDNSEthAddr zeroEthAddr; 2208extern const mDNSv4Addr onesIPv4Addr; 2209extern const mDNSv6Addr onesIPv6Addr; 2210extern const mDNSAddr zeroAddr; 2211 2212extern const mDNSInterfaceID mDNSInterface_Any; // Zero 2213extern const mDNSInterfaceID mDNSInterface_LocalOnly; // Special value 2214 2215extern const mDNSIPPort UnicastDNSPort; 2216extern const mDNSIPPort NATPMPPort; 2217extern const mDNSIPPort DNSEXTPort; 2218extern const mDNSIPPort MulticastDNSPort; 2219extern const mDNSIPPort LoopbackIPCPort; 2220 2221extern const mDNSv4Addr AllDNSAdminGroup; 2222#define AllDNSLinkGroupv4 (AllDNSLinkGroup_v4.ip.v4) 2223#define AllDNSLinkGroupv6 (AllDNSLinkGroup_v6.ip.v6) 2224extern const mDNSAddr AllDNSLinkGroup_v4; 2225extern const mDNSAddr AllDNSLinkGroup_v6; 2226 2227extern const mDNSOpaque16 zeroID; 2228extern const mDNSOpaque16 QueryFlags; 2229extern const mDNSOpaque16 uQueryFlags; 2230extern const mDNSOpaque16 ResponseFlags; 2231extern const mDNSOpaque16 UpdateReqFlags; 2232extern const mDNSOpaque16 UpdateRespFlags; 2233 2234#define localdomain (*(const domainname *)"\x5" "local") 2235#define LocalReverseMapDomain (*(const domainname *)"\x3" "254" "\x3" "169" "\x7" "in-addr" "\x4" "arpa") 2236 2237// *************************************************************************** 2238#if 0 2239#pragma mark - Inline functions 2240#endif 2241 2242#if (defined(_MSC_VER)) 2243 #define mDNSinline static __inline 2244#elif ((__GNUC__ > 2) || ((__GNUC__ == 2) && (__GNUC_MINOR__ >= 9))) 2245 #define mDNSinline static inline 2246#endif 2247 2248// If we're not doing inline functions, then this header needs to have the extern declarations 2249#if !defined(mDNSinline) 2250extern mDNSs32 NonZeroTime(mDNSs32 t); 2251extern mDNSu16 mDNSVal16(mDNSOpaque16 x); 2252extern mDNSu32 mDNSVal32(mDNSOpaque32 x); 2253extern mDNSOpaque16 mDNSOpaque16fromIntVal(mDNSu16 v); 2254extern mDNSOpaque32 mDNSOpaque32fromIntVal(mDNSu32 v); 2255#endif 2256 2257// If we're compiling the particular C file that instantiates our inlines, then we 2258// define "mDNSinline" (to empty string) so that we generate code in the following section 2259#if (!defined(mDNSinline) && mDNS_InstantiateInlines) 2260#define mDNSinline 2261#endif 2262 2263#ifdef mDNSinline 2264 2265mDNSinline mDNSs32 NonZeroTime(mDNSs32 t) { if (t) return(t); else return(1); } 2266 2267mDNSinline mDNSu16 mDNSVal16(mDNSOpaque16 x) { return((mDNSu16)((mDNSu16)x.b[0] << 8 | (mDNSu16)x.b[1])); } 2268mDNSinline mDNSu32 mDNSVal32(mDNSOpaque32 x) { return((mDNSu32)((mDNSu32)x.b[0] << 24 | (mDNSu32)x.b[1] << 16 | (mDNSu32)x.b[2] << 8 | (mDNSu32)x.b[3])); } 2269 2270mDNSinline mDNSOpaque16 mDNSOpaque16fromIntVal(mDNSu16 v) 2271 { 2272 mDNSOpaque16 x; 2273 x.b[0] = (mDNSu8)(v >> 8); 2274 x.b[1] = (mDNSu8)(v & 0xFF); 2275 return(x); 2276 } 2277 2278mDNSinline mDNSOpaque32 mDNSOpaque32fromIntVal(mDNSu32 v) 2279 { 2280 mDNSOpaque32 x; 2281 x.b[0] = (mDNSu8) (v >> 24) ; 2282 x.b[1] = (mDNSu8)((v >> 16) & 0xFF); 2283 x.b[2] = (mDNSu8)((v >> 8 ) & 0xFF); 2284 x.b[3] = (mDNSu8)((v ) & 0xFF); 2285 return x; 2286 } 2287 2288#endif 2289 2290// *************************************************************************** 2291#if 0 2292#pragma mark - Main Client Functions 2293#endif 2294 2295// Every client should call mDNS_Init, passing in storage for the mDNS object and the mDNS_PlatformSupport object. 2296// 2297// Clients that are only advertising services should use mDNS_Init_NoCache and mDNS_Init_ZeroCacheSize. 2298// Clients that plan to perform queries (mDNS_StartQuery, mDNS_StartBrowse, mDNS_StartResolveService, etc.) 2299// need to provide storage for the resource record cache, or the query calls will return 'mStatus_NoCache'. 2300// The rrcachestorage parameter is the address of memory for the resource record cache, and 2301// the rrcachesize parameter is the number of entries in the CacheRecord array passed in. 2302// (i.e. the size of the cache memory needs to be sizeof(CacheRecord) * rrcachesize). 2303// OS X 10.3 Panther uses an initial cache size of 64 entries, and then mDNSCore sends an 2304// mStatus_GrowCache message if it needs more. 2305// 2306// Most clients should use mDNS_Init_AdvertiseLocalAddresses. This causes mDNSCore to automatically 2307// create the correct address records for all the hosts interfaces. If you plan to advertise 2308// services being offered by the local machine, this is almost always what you want. 2309// There are two cases where you might use mDNS_Init_DontAdvertiseLocalAddresses: 2310// 1. A client-only device, that browses for services but doesn't advertise any of its own. 2311// 2. A proxy-registration service, that advertises services being offered by other machines, and takes 2312// the appropriate steps to manually create the correct address records for those other machines. 2313// In principle, a proxy-like registration service could manually create address records for its own machine too, 2314// but this would be pointless extra effort when using mDNS_Init_AdvertiseLocalAddresses does that for you. 2315// 2316// When mDNS has finished setting up the client's callback is called 2317// A client can also spin and poll the mDNSPlatformStatus field to see when it changes from mStatus_Waiting to mStatus_NoError 2318// 2319// Call mDNS_Close to tidy up before exiting 2320// 2321// Call mDNS_Register with a completed AuthRecord object to register a resource record 2322// If the resource record type is kDNSRecordTypeUnique (or kDNSknownunique) then if a conflicting resource record is discovered, 2323// the resource record's mDNSRecordCallback will be called with error code mStatus_NameConflict. The callback should deregister 2324// the record, and may then try registering the record again after picking a new name (e.g. by automatically appending a number). 2325// Following deregistration, the RecordCallback will be called with result mStatus_MemFree to signal that it is safe to deallocate 2326// the record's storage (memory must be freed asynchronously to allow for goodbye packets and dynamic update deregistration). 2327// 2328// Call mDNS_StartQuery to initiate a query. mDNS will proceed to issue Multicast DNS query packets, and any time a response 2329// is received containing a record which matches the question, the DNSQuestion's mDNSAnswerCallback function will be called 2330// Call mDNS_StopQuery when no more answers are required 2331// 2332// Care should be taken on multi-threaded or interrupt-driven environments. 2333// The main mDNS routines call mDNSPlatformLock() on entry and mDNSPlatformUnlock() on exit; 2334// each platform layer needs to implement these appropriately for its respective platform. 2335// For example, if the support code on a particular platform implements timer callbacks at interrupt time, then 2336// mDNSPlatformLock/Unlock need to disable interrupts or do similar concurrency control to ensure that the mDNS 2337// code is not entered by an interrupt-time timer callback while in the middle of processing a client call. 2338 2339extern mStatus mDNS_Init (mDNS *const m, mDNS_PlatformSupport *const p, 2340 CacheEntity *rrcachestorage, mDNSu32 rrcachesize, 2341 mDNSBool AdvertiseLocalAddresses, 2342 mDNSCallback *Callback, void *Context); 2343// See notes above on use of NoCache/ZeroCacheSize 2344#define mDNS_Init_NoCache mDNSNULL 2345#define mDNS_Init_ZeroCacheSize 0 2346// See notes above on use of Advertise/DontAdvertiseLocalAddresses 2347#define mDNS_Init_AdvertiseLocalAddresses mDNStrue 2348#define mDNS_Init_DontAdvertiseLocalAddresses mDNSfalse 2349#define mDNS_Init_NoInitCallback mDNSNULL 2350#define mDNS_Init_NoInitCallbackContext mDNSNULL 2351 2352extern void mDNS_GrowCache (mDNS *const m, CacheEntity *storage, mDNSu32 numrecords); 2353extern void mDNS_Close (mDNS *const m); 2354extern mDNSs32 mDNS_Execute (mDNS *const m); 2355 2356extern mStatus mDNS_Register (mDNS *const m, AuthRecord *const rr); 2357extern mStatus mDNS_Update (mDNS *const m, AuthRecord *const rr, mDNSu32 newttl, 2358 const mDNSu16 newrdlength, RData *const newrdata, mDNSRecordUpdateCallback *Callback); 2359extern mStatus mDNS_Deregister(mDNS *const m, AuthRecord *const rr); 2360 2361extern mStatus mDNS_StartQuery(mDNS *const m, DNSQuestion *const question); 2362extern mStatus mDNS_StopQuery (mDNS *const m, DNSQuestion *const question); 2363extern mStatus mDNS_Reconfirm (mDNS *const m, CacheRecord *const cacherr); 2364extern mStatus mDNS_ReconfirmByValue(mDNS *const m, ResourceRecord *const rr); 2365extern mDNSs32 mDNS_TimeNow(const mDNS *const m); 2366 2367// *************************************************************************** 2368#if 0 2369#pragma mark - Platform support functions that are accessible to the client layer too 2370#endif 2371 2372extern mDNSs32 mDNSPlatformOneSecond; 2373 2374// *************************************************************************** 2375#if 0 2376#pragma mark - General utility and helper functions 2377#endif 2378 2379// mDNS_RegisterService is a single call to register the set of resource records associated with a given named service. 2380// 2381// mDNS_StartResolveService is single call which is equivalent to multiple calls to mDNS_StartQuery, 2382// to find the IP address, port number, and demultiplexing information for a given named service. 2383// As with mDNS_StartQuery, it executes asynchronously, and calls the ServiceInfoQueryCallback when the answer is 2384// found. After the service is resolved, the client should call mDNS_StopResolveService to complete the transaction. 2385// The client can also call mDNS_StopResolveService at any time to abort the transaction. 2386// 2387// mDNS_AddRecordToService adds an additional record to a Service Record Set. This record may be deregistered 2388// via mDNS_RemoveRecordFromService, or by deregistering the service. mDNS_RemoveRecordFromService is passed a 2389// callback to free the memory associated with the extra RR when it is safe to do so. The ExtraResourceRecord 2390// object can be found in the record's context pointer. 2391 2392// mDNS_GetBrowseDomains is a special case of the mDNS_StartQuery call, where the resulting answers 2393// are a list of PTR records indicating (in the rdata) domains that are recommended for browsing. 2394// After getting the list of domains to browse, call mDNS_StopQuery to end the search. 2395// mDNS_GetDefaultBrowseDomain returns the name of the domain that should be highlighted by default. 2396// 2397// mDNS_GetRegistrationDomains and mDNS_GetDefaultRegistrationDomain are the equivalent calls to get the list 2398// of one or more domains that should be offered to the user as choices for where they may register their service, 2399// and the default domain in which to register in the case where the user has made no selection. 2400 2401extern void mDNS_SetupResourceRecord(AuthRecord *rr, RData *RDataStorage, mDNSInterfaceID InterfaceID, 2402 mDNSu16 rrtype, mDNSu32 ttl, mDNSu8 RecordType, mDNSRecordCallback Callback, void *Context); 2403 2404extern mStatus mDNS_RegisterService (mDNS *const m, ServiceRecordSet *sr, 2405 const domainlabel *const name, const domainname *const type, const domainname *const domain, 2406 const domainname *const host, mDNSIPPort port, const mDNSu8 txtinfo[], mDNSu16 txtlen, 2407 AuthRecord *SubTypes, mDNSu32 NumSubTypes, 2408 const mDNSInterfaceID InterfaceID, mDNSServiceCallback Callback, void *Context); 2409extern mStatus mDNS_AddRecordToService(mDNS *const m, ServiceRecordSet *sr, ExtraResourceRecord *extra, RData *rdata, mDNSu32 ttl); 2410extern mStatus mDNS_RemoveRecordFromService(mDNS *const m, ServiceRecordSet *sr, ExtraResourceRecord *extra, mDNSRecordCallback MemFreeCallback, void *Context); 2411extern mStatus mDNS_RenameAndReregisterService(mDNS *const m, ServiceRecordSet *const sr, const domainlabel *newname); 2412extern mStatus mDNS_DeregisterService(mDNS *const m, ServiceRecordSet *sr); 2413 2414extern mStatus mDNS_RegisterNoSuchService(mDNS *const m, AuthRecord *const rr, 2415 const domainlabel *const name, const domainname *const type, const domainname *const domain, 2416 const domainname *const host, 2417 const mDNSInterfaceID InterfaceID, mDNSRecordCallback Callback, void *Context); 2418#define mDNS_DeregisterNoSuchService mDNS_Deregister 2419 2420extern mStatus mDNS_StartBrowse(mDNS *const m, DNSQuestion *const question, 2421 const domainname *const srv, const domainname *const domain, 2422 const mDNSInterfaceID InterfaceID, mDNSBool ForceMCast, mDNSQuestionCallback *Callback, void *Context); 2423#define mDNS_StopBrowse mDNS_StopQuery 2424 2425extern mStatus mDNS_StartResolveService(mDNS *const m, ServiceInfoQuery *query, ServiceInfo *info, mDNSServiceInfoQueryCallback *Callback, void *Context); 2426extern void mDNS_StopResolveService (mDNS *const m, ServiceInfoQuery *query); 2427 2428typedef enum 2429 { 2430 mDNS_DomainTypeBrowse = 0, 2431 mDNS_DomainTypeBrowseDefault = 1, 2432 mDNS_DomainTypeBrowseLegacy = 2, 2433 mDNS_DomainTypeRegistration = 3, 2434 mDNS_DomainTypeRegistrationDefault = 4, 2435 2436 mDNS_DomainTypeMax = 4 2437 } mDNS_DomainType; 2438 2439extern const char *const mDNS_DomainTypeNames[]; 2440 2441extern mStatus mDNS_GetDomains(mDNS *const m, DNSQuestion *const question, mDNS_DomainType DomainType, const domainname *dom, 2442 const mDNSInterfaceID InterfaceID, mDNSQuestionCallback *Callback, void *Context); 2443#define mDNS_StopGetDomains mDNS_StopQuery 2444extern mStatus mDNS_AdvertiseDomains(mDNS *const m, AuthRecord *rr, mDNS_DomainType DomainType, const mDNSInterfaceID InterfaceID, char *domname); 2445#define mDNS_StopAdvertiseDomains mDNS_Deregister 2446 2447// *************************************************************************** 2448#if 0 2449#pragma mark - DNS name utility functions 2450#endif 2451 2452// In order to expose the full capabilities of the DNS protocol (which allows any arbitrary eight-bit values 2453// in domain name labels, including unlikely characters like ascii nulls and even dots) all the mDNS APIs 2454// work with DNS's native length-prefixed strings. For convenience in C, the following utility functions 2455// are provided for converting between C's null-terminated strings and DNS's length-prefixed strings. 2456 2457// Assignment 2458// A simple C structure assignment of a domainname can cause a protection fault by accessing unmapped memory, 2459// because that object is defined to be 256 bytes long, but not all domainname objects are truly the full size. 2460// This macro uses mDNSPlatformMemCopy() to make sure it only touches the actual bytes that are valid. 2461#define AssignDomainName(DST, SRC) mDNSPlatformMemCopy((SRC)->c, (DST)->c, DomainNameLength((SRC))) 2462 2463// Comparison functions 2464extern mDNSBool SameDomainLabel(const mDNSu8 *a, const mDNSu8 *b); 2465extern mDNSBool SameDomainName(const domainname *const d1, const domainname *const d2); 2466extern mDNSBool IsLocalDomain(const domainname *d); // returns true for domains that by default should be looked up using link-local multicast 2467 2468// Get total length of domain name, in native DNS format, including terminal root label 2469// (e.g. length of "com." is 5 (length byte, three data bytes, final zero) 2470extern mDNSu16 DomainNameLength(const domainname *const name); 2471 2472// Append functions to append one or more labels to an existing native format domain name: 2473// AppendLiteralLabelString adds a single label from a literal C string, with no escape character interpretation. 2474// AppendDNSNameString adds zero or more labels from a C string using conventional DNS dots-and-escaping interpretation 2475// AppendDomainLabel adds a single label from a native format domainlabel 2476// AppendDomainName adds zero or more labels from a native format domainname 2477extern mDNSu8 *AppendLiteralLabelString(domainname *const name, const char *cstr); 2478extern mDNSu8 *AppendDNSNameString (domainname *const name, const char *cstr); 2479extern mDNSu8 *AppendDomainLabel (domainname *const name, const domainlabel *const label); 2480extern mDNSu8 *AppendDomainName (domainname *const name, const domainname *const append); 2481 2482// Convert from null-terminated string to native DNS format: 2483// The DomainLabel form makes a single label from a literal C string, with no escape character interpretation. 2484// The DomainName form makes native format domain name from a C string using conventional DNS interpretation: 2485// dots separate labels, and within each label, '\.' represents a literal dot, '\\' represents a literal 2486// backslash and backslash with three decimal digits (e.g. \000) represents an arbitrary byte value. 2487extern mDNSBool MakeDomainLabelFromLiteralString(domainlabel *const label, const char *cstr); 2488extern mDNSu8 *MakeDomainNameFromDNSNameString (domainname *const name, const char *cstr); 2489 2490// Convert native format domainlabel or domainname back to C string format 2491// IMPORTANT: 2492// When using ConvertDomainLabelToCString, the target buffer must be MAX_ESCAPED_DOMAIN_LABEL (254) bytes long 2493// to guarantee there will be no buffer overrun. It is only safe to use a buffer shorter than this in rare cases 2494// where the label is known to be constrained somehow (for example, if the label is known to be either "_tcp" or "_udp"). 2495// Similarly, when using ConvertDomainNameToCString, the target buffer must be MAX_ESCAPED_DOMAIN_NAME (1005) bytes long. 2496// See definitions of MAX_ESCAPED_DOMAIN_LABEL and MAX_ESCAPED_DOMAIN_NAME for more detailed explanation. 2497extern char *ConvertDomainLabelToCString_withescape(const domainlabel *const name, char *cstr, char esc); 2498#define ConvertDomainLabelToCString_unescaped(D,C) ConvertDomainLabelToCString_withescape((D), (C), 0) 2499#define ConvertDomainLabelToCString(D,C) ConvertDomainLabelToCString_withescape((D), (C), '\\') 2500extern char *ConvertDomainNameToCString_withescape(const domainname *const name, char *cstr, char esc); 2501#define ConvertDomainNameToCString_unescaped(D,C) ConvertDomainNameToCString_withescape((D), (C), 0) 2502#define ConvertDomainNameToCString(D,C) ConvertDomainNameToCString_withescape((D), (C), '\\') 2503 2504extern void ConvertUTF8PstringToRFC1034HostLabel(const mDNSu8 UTF8Name[], domainlabel *const hostlabel); 2505 2506extern mDNSu8 *ConstructServiceName(domainname *const fqdn, const domainlabel *name, const domainname *type, const domainname *const domain); 2507extern mDNSBool DeconstructServiceName(const domainname *const fqdn, domainlabel *const name, domainname *const type, domainname *const domain); 2508 2509// Note: Some old functions have been replaced by more sensibly-named versions. 2510// You can uncomment the hash-defines below if you don't want to have to change your source code right away. 2511// When updating your code, note that (unlike the old versions) *all* the new routines take the target object 2512// as their first parameter. 2513//#define ConvertCStringToDomainName(SRC,DST) MakeDomainNameFromDNSNameString((DST),(SRC)) 2514//#define ConvertCStringToDomainLabel(SRC,DST) MakeDomainLabelFromLiteralString((DST),(SRC)) 2515//#define AppendStringLabelToName(DST,SRC) AppendLiteralLabelString((DST),(SRC)) 2516//#define AppendStringNameToName(DST,SRC) AppendDNSNameString((DST),(SRC)) 2517//#define AppendDomainLabelToName(DST,SRC) AppendDomainLabel((DST),(SRC)) 2518//#define AppendDomainNameToName(DST,SRC) AppendDomainName((DST),(SRC)) 2519 2520// *************************************************************************** 2521#if 0 2522#pragma mark - Other utility functions and macros 2523#endif 2524 2525// mDNS_vsnprintf/snprintf return the number of characters written, excluding the final terminating null. 2526// The output is always null-terminated: for example, if the output turns out to be exactly buflen long, 2527// then the output will be truncated by one character to allow space for the terminating null. 2528// Unlike standard C vsnprintf/snprintf, they return the number of characters *actually* written, 2529// not the number of characters that *would* have been printed were buflen unlimited. 2530extern mDNSu32 mDNS_vsnprintf(char *sbuffer, mDNSu32 buflen, const char *fmt, va_list arg); 2531extern mDNSu32 mDNS_snprintf(char *sbuffer, mDNSu32 buflen, const char *fmt, ...) IS_A_PRINTF_STYLE_FUNCTION(3,4); 2532extern mDNSu32 NumCacheRecordsForInterfaceID(const mDNS *const m, mDNSInterfaceID id); 2533extern char *DNSTypeName(mDNSu16 rrtype); 2534extern char *GetRRDisplayString_rdb(const ResourceRecord *rr, RDataBody *rd, char *buffer); 2535#define RRDisplayString(m, rr) GetRRDisplayString_rdb(rr, &(rr)->rdata->u, (m)->MsgBuffer) 2536#define ARDisplayString(m, rr) GetRRDisplayString_rdb(&(rr)->resrec, &(rr)->resrec.rdata->u, (m)->MsgBuffer) 2537#define CRDisplayString(m, rr) GetRRDisplayString_rdb(&(rr)->resrec, &(rr)->resrec.rdata->u, (m)->MsgBuffer) 2538extern mDNSBool mDNSSameAddress(const mDNSAddr *ip1, const mDNSAddr *ip2); 2539extern void IncrementLabelSuffix(domainlabel *name, mDNSBool RichText); 2540extern mDNSBool IsPrivateV4Addr(mDNSAddr *addr); // returns true for RFC1918 private addresses 2541 2542#define mDNSSameIPv4Address(A,B) ((A).NotAnInteger == (B).NotAnInteger) 2543#define mDNSSameIPv6Address(A,B) ((A).l[0] == (B).l[0] && (A).l[1] == (B).l[1] && (A).l[2] == (B).l[2] && (A).l[3] == (B).l[3]) 2544#define mDNSSameEthAddress(A,B) ((A)->w[0] == (B)->w[0] && (A)->w[1] == (B)->w[1] && (A)->w[2] == (B)->w[2]) 2545 2546#define mDNSIPv4AddressIsZero(A) mDNSSameIPv4Address((A), zerov4Addr) 2547#define mDNSIPv6AddressIsZero(A) mDNSSameIPv6Address((A), zerov6Addr) 2548 2549#define mDNSIPv4AddressIsOnes(A) mDNSSameIPv4Address((A), onesIPv4Addr) 2550#define mDNSIPv6AddressIsOnes(A) mDNSSameIPv6Address((A), onesIPv6Addr) 2551 2552#define mDNSAddressIsAllDNSLinkGroup(X) ( \ 2553 ((X)->type == mDNSAddrType_IPv4 && mDNSSameIPv4Address((X)->ip.v4, AllDNSLinkGroupv4)) || \ 2554 ((X)->type == mDNSAddrType_IPv6 && mDNSSameIPv6Address((X)->ip.v6, AllDNSLinkGroupv6)) ) 2555 2556#define mDNSAddressIsZero(X) ( \ 2557 ((X)->type == mDNSAddrType_IPv4 && mDNSIPv4AddressIsZero((X)->ip.v4)) || \ 2558 ((X)->type == mDNSAddrType_IPv6 && mDNSIPv6AddressIsZero((X)->ip.v6)) ) 2559 2560#define mDNSAddressIsValidNonZero(X) ( \ 2561 ((X)->type == mDNSAddrType_IPv4 && !mDNSIPv4AddressIsZero((X)->ip.v4)) || \ 2562 ((X)->type == mDNSAddrType_IPv6 && !mDNSIPv6AddressIsZero((X)->ip.v6)) ) 2563 2564#define mDNSAddressIsOnes(X) ( \ 2565 ((X)->type == mDNSAddrType_IPv4 && mDNSIPv4AddressIsOnes((X)->ip.v4)) || \ 2566 ((X)->type == mDNSAddrType_IPv6 && mDNSIPv6AddressIsOnes((X)->ip.v6)) ) 2567 2568#define mDNSAddressIsValid(X) ( \ 2569 ((X)->type == mDNSAddrType_IPv4) ? !(mDNSIPv4AddressIsZero((X)->ip.v4) || mDNSIPv4AddressIsOnes((X)->ip.v4)) : \ 2570 ((X)->type == mDNSAddrType_IPv6) ? !(mDNSIPv6AddressIsZero((X)->ip.v6) || mDNSIPv6AddressIsOnes((X)->ip.v6)) : mDNSfalse) 2571 2572 2573// *************************************************************************** 2574#if 0 2575#pragma mark - Authentication Support 2576#endif 2577 2578#define HMAC_LEN 64 2579#define HMAC_IPAD 0x36 2580#define HMAC_OPAD 0x5c 2581#define MD5_LEN 16 2582 2583// padded keys for inned/outer hash rounds 2584typedef struct 2585 { 2586 mDNSu8 ipad[HMAC_LEN]; 2587 mDNSu8 opad[HMAC_LEN]; 2588 } HMAC_Key; 2589 2590// Internal data structure to maintain authentication information for an update domain 2591typedef struct uDNS_AuthInfo 2592 { 2593 domainname zone; 2594 domainname keyname; 2595 HMAC_Key key; 2596 struct uDNS_AuthInfo *next; 2597 } uDNS_AuthInfo; 2598 2599// Unicast DNS and Dynamic Update specific Client Calls 2600// 2601// mDNS_SetSecretForZone tells the core to authenticate (via TSIG with an HMAC_MD5 hash of the shared secret) 2602// when dynamically updating a given zone (and its subdomains). The key used in authentication must be in 2603// domain name format. The shared secret must be a null-terminated base64 encoded string. A minimum size of 2604// 16 bytes (128 bits) is recommended for an MD5 hash as per RFC 2485. 2605// Calling this routine multiple times for a zone replaces previously entered values. Call with a NULL key 2606// to dissable authentication for the zone. 2607 2608extern mStatus mDNS_SetSecretForZone(mDNS *m, const domainname *zone, const domainname *key, const char *sharedSecret); 2609 2610// Hostname/Unicast Interface Configuration 2611 2612// All hostnames advertised point to one IPv4 address and/or one IPv6 address, set via SetPrimaryInterfaceInfo. Invoking this routine 2613// updates all existing hostnames to point to the new address. 2614 2615// A hostname is added via AddDynDNSHostName, which points to the primary interface's v4 and/or v6 addresss 2616 2617// The status callback is invoked to convey success or failure codes - the callback should not modify the AuthRecord or free memory. 2618// Added hostnames may be removed (deregistered) via mDNS_RemoveDynDNSHostName. 2619 2620// Host domains added prior to specification of the primary interface address and computer name will be deferred until 2621// these values are initialized. 2622 2623// When routable V4 interfaces are added or removed, mDNS_UpdateLLQs should be called to re-estabish LLQs in case the 2624// destination address for events (i.e. the route) has changed. For performance reasons, the caller is responsible for 2625// batching changes, e.g. calling the routine only once if multiple interfaces are simultanously removed or added. 2626 2627// DNS servers used to resolve unicast queries are specified by mDNS_AddDNSServer, and may later be removed via mDNS_DeleteDNSServers. 2628// For "split" DNS configurations, in which queries for different domains are sent to different servers (e.g. VPN and external), 2629// a domain may be associated with a DNS server. For standard configurations, specify the root label (".") or NULL. 2630 2631extern void mDNS_AddDynDNSHostName(mDNS *m, const domainname *fqdn, mDNSRecordCallback *StatusCallback, const void *StatusContext); 2632extern void mDNS_RemoveDynDNSHostName(mDNS *m, const domainname *fqdn); 2633extern void mDNS_SetPrimaryInterfaceInfo(mDNS *m, const mDNSAddr *v4addr, const mDNSAddr *v6addr, const mDNSAddr *router); 2634extern void mDNS_UpdateLLQs(mDNS *m); 2635extern void mDNS_AddDNSServer(mDNS *const m, const mDNSAddr *dnsAddr, const domainname *domain); 2636extern void mDNS_DeleteDNSServers(mDNS *const m); 2637 2638// Routines called by the core, exported by DNSDigest.c 2639 2640// Convert a base64 encoded key into a binary byte stream 2641extern mDNSs32 DNSDigest_Base64ToBin(const char *src, mDNSu8 *target, mDNSu32 targsize); 2642 2643// Convert an arbitrary binary key (of any length) into an HMAC key (stored in AuthInfo struct) 2644extern void DNSDigest_ConstructHMACKey(uDNS_AuthInfo *info, const mDNSu8 *key, mDNSu32 len); 2645 2646// sign a DNS message. The message must be compete, with all values in network byte order. end points to the end 2647// of the message, and is modified by this routine. numAdditionals is a pointer to the number of additional 2648// records in HOST byte order, which is incremented upon successful completion of this routine. The function returns 2649// the new end pointer on success, and NULL on failure. 2650extern mDNSu8 *DNSDigest_SignMessage(DNSMessage *msg, mDNSu8 **end, mDNSu16 *numAdditionals, uDNS_AuthInfo *info); 2651 2652// *************************************************************************** 2653#if 0 2654#pragma mark - PlatformSupport interface 2655#endif 2656 2657// This section defines the interface to the Platform Support layer. 2658// Normal client code should not use any of types defined here, or directly call any of the functions defined here. 2659// The definitions are placed here because sometimes clients do use these calls indirectly, via other supported client operations. 2660// For example, AssignDomainName is a macro defined using mDNSPlatformMemCopy() 2661 2662// Every platform support module must provide the following functions. 2663// mDNSPlatformInit() typically opens a communication endpoint, and starts listening for mDNS packets. 2664// When Setup is complete, the platform support layer calls mDNSCoreInitComplete(). 2665// mDNSPlatformSendUDP() sends one UDP packet 2666// When a packet is received, the PlatformSupport code calls mDNSCoreReceive() 2667// mDNSPlatformClose() tidies up on exit 2668// 2669// Note: mDNSPlatformMemAllocate/mDNSPlatformMemFree are only required for handling oversized resource records and unicast DNS. 2670// If your target platform has a well-defined specialized application, and you know that all the records it uses 2671// are InlineCacheRDSize or less, then you can just make a simple mDNSPlatformMemAllocate() stub that always returns 2672// NULL. InlineCacheRDSize is a compile-time constant, which is set by default to 64. If you need to handle records 2673// a little larger than this and you don't want to have to implement run-time allocation and freeing, then you 2674// can raise the value of this constant to a suitable value (at the expense of increased memory usage). 2675// 2676// USE CAUTION WHEN CALLING mDNSPlatformRawTime: The m->timenow_adjust correction factor needs to be added 2677// Generally speaking: 2678// Code that's protected by the main mDNS lock should just use the m->timenow value 2679// Code outside the main mDNS lock should use mDNS_TimeNow(m) to get properly adjusted time 2680// In certain cases there may be reasons why it's necessary to get the time without taking the lock first 2681// (e.g. inside the routines that are doing the locking and unlocking, where a call to get the lock would result in a 2682// recursive loop); in these cases use mDNS_TimeNow_NoLock(m) to get mDNSPlatformRawTime with the proper correction factor added. 2683// 2684// mDNSPlatformUTC returns the time, in seconds, since Jan 1st 1970 UTC and is required for generating TSIG records 2685 2686extern mStatus mDNSPlatformInit (mDNS *const m); 2687extern void mDNSPlatformClose (mDNS *const m); 2688extern mStatus mDNSPlatformSendUDP(const mDNS *const m, const void *const msg, const mDNSu8 *const end, 2689mDNSInterfaceID InterfaceID, const mDNSAddr *dst, mDNSIPPort dstport); 2690 2691extern void mDNSPlatformLock (const mDNS *const m); 2692extern void mDNSPlatformUnlock (const mDNS *const m); 2693 2694extern void mDNSPlatformStrCopy (const void *src, void *dst); 2695extern mDNSu32 mDNSPlatformStrLen (const void *src); 2696extern void mDNSPlatformMemCopy (const void *src, void *dst, mDNSu32 len); 2697extern mDNSBool mDNSPlatformMemSame (const void *src, const void *dst, mDNSu32 len); 2698extern void mDNSPlatformMemZero ( void *dst, mDNSu32 len); 2699extern void * mDNSPlatformMemAllocate (mDNSu32 len); 2700extern void mDNSPlatformMemFree (void *mem); 2701extern mDNSu32 mDNSPlatformRandomSeed (void); 2702extern mStatus mDNSPlatformTimeInit (void); 2703extern mDNSs32 mDNSPlatformRawTime (void); 2704extern mDNSs32 mDNSPlatformUTC (void); 2705#define mDNS_TimeNow_NoLock(m) (mDNSPlatformRawTime() + m->timenow_adjust) 2706 2707// Platform support modules should provide the following functions to map between opaque interface IDs 2708// and interface indexes in order to support the DNS-SD API. If your target platform does not support 2709// multiple interfaces and/or does not support the DNS-SD API, these functions can be empty. 2710extern mDNSInterfaceID mDNSPlatformInterfaceIDfromInterfaceIndex(mDNS *const m, mDNSu32 index); 2711extern mDNSu32 mDNSPlatformInterfaceIndexfromInterfaceID(mDNS *const m, mDNSInterfaceID id); 2712 2713// Every platform support module must provide the following functions if it is to support unicast DNS 2714// and Dynamic Update. 2715// All TCP socket operations implemented by the platform layer MUST NOT BLOCK. 2716// mDNSPlatformTCPConnect initiates a TCP connection with a peer, adding the socket descriptor to the 2717// main event loop. The return value indicates whether the connection succeeded, failed, or is pending 2718// (i.e. the call would block.) On return, the descriptor parameter is set to point to the connected socket. 2719// The TCPConnectionCallback is subsequently invoked when the connection 2720// completes (in which case the ConnectionEstablished parameter is true), or data is available for 2721// reading on the socket (indicated by the ConnectionEstablished parameter being false.) If the connection 2722// asynchronously fails, the TCPConnectionCallback should be invoked as usual, with the error being 2723// returned in subsequent calls to PlatformReadTCP or PlatformWriteTCP. (This allows for platforms 2724// with limited asynchronous error detection capabilities.) PlatformReadTCP and PlatformWriteTCP must 2725// return the number of bytes read/written, 0 if the call would block, and -1 if an error. 2726// PlatformTCPCloseConnection must close the connection to the peer and remove the descriptor from the 2727// event loop. CloseConnectin may be called at any time, including in a ConnectionCallback. 2728 2729typedef void (*TCPConnectionCallback)(int sd, void *context, mDNSBool ConnectionEstablished); 2730extern mStatus mDNSPlatformTCPConnect(const mDNSAddr *dst, mDNSOpaque16 dstport, mDNSInterfaceID InterfaceID, 2731 TCPConnectionCallback callback, void *context, int *descriptor); 2732extern void mDNSPlatformTCPCloseConnection(int sd); 2733extern int mDNSPlatformReadTCP(int sd, void *buf, int buflen); 2734extern int mDNSPlatformWriteTCP(int sd, const char *msg, int len); 2735 2736// Platforms that support unicast browsing and dynamic update registration for clients who do not specify a domain 2737// in browse/registration calls must implement these routines to get the "default" browse/registration list. 2738// The Get() functions must return a linked list of DNameListElem structs, allocated via mDNSPlatformMemAllocate. 2739// Platforms may implement the Get() calls via the mDNS_CopyDNameList() helper routine. 2740// Callers should free lists obtained via the Get() calls with th mDNS_FreeDNameList routine, provided by the core. 2741 2742typedef struct DNameListElem 2743 { 2744 domainname name; 2745 struct DNameListElem *next; 2746 } DNameListElem; 2747 2748extern DNameListElem *mDNSPlatformGetSearchDomainList(void); 2749extern DNameListElem *mDNSPlatformGetRegDomainList(void); 2750 2751// Helper functions provided by the core 2752extern DNameListElem *mDNS_CopyDNameList(const DNameListElem *orig); 2753extern void mDNS_FreeDNameList(DNameListElem *list); 2754 2755#ifdef _LEGACY_NAT_TRAVERSAL_ 2756// Support for legacy NAT traversal protocols, implemented by the platform layer and callable by the core. 2757 2758#define DYN_PORT_MIN 49152 // ephemeral port range 2759#define DYN_PORT_MAX 65535 2760#define LEGACY_NATMAP_MAX_TRIES 4 // if our desired mapping is taken, how many times we try mapping to a random port 2761 2762extern mStatus LNT_GetPublicIP(mDNSOpaque32 *ip); 2763extern mStatus LNT_MapPort(mDNSIPPort priv, mDNSIPPort pub, mDNSBool tcp); 2764extern mStatus LNT_UnmapPort(mDNSIPPort PubPort, mDNSBool tcp); 2765#endif // _LEGACY_NAT_TRAVERSAL_ 2766 2767// The core mDNS code provides these functions, for the platform support code to call at appropriate times 2768// 2769// mDNS_SetFQDN() is called once on startup (typically from mDNSPlatformInit()) 2770// and then again on each subsequent change of the host name. 2771// 2772// mDNS_RegisterInterface() is used by the platform support layer to inform mDNSCore of what 2773// physical and/or logical interfaces are available for sending and receiving packets. 2774// Typically it is called on startup for each available interface, but register/deregister may be 2775// called again later, on multiple occasions, to inform the core of interface configuration changes. 2776// If set->Advertise is set non-zero, then mDNS_RegisterInterface() also registers the standard 2777// resource records that should be associated with every publicised IP address/interface: 2778// -- Name-to-address records (A/AAAA) 2779// -- Address-to-name records (PTR) 2780// -- Host information (HINFO) 2781// IMPORTANT: The specified mDNSInterfaceID MUST NOT be 0, -1, or -2; these values have special meaning 2782// mDNS_RegisterInterface does not result in the registration of global hostnames via dynamic update - 2783// see mDNS_SetPrimaryInterfaceInfo, mDNS_AddDynDNSHostName, etc. for this purpose. 2784// Note that the set may be deallocated immediately after it is deregistered via mDNS_DeegisterInterface. 2785// 2786// mDNS_RegisterDNS() is used by the platform support layer to provide the core with the addresses of 2787// available domain name servers for unicast queries/updates. RegisterDNS() should be called once for 2788// each name server, typically at startup, or when a new name server becomes available. DeregiterDNS() 2789// must be called whenever a registered name server becomes unavailable. DeregisterDNSList deregisters 2790// all registered servers. mDNS_DNSRegistered() returns true if one or more servers are registered in the core. 2791// 2792// mDNSCoreInitComplete() is called when the platform support layer is finished. 2793// Typically this is at the end of mDNSPlatformInit(), but may be later 2794// (on platforms like OT that allow asynchronous initialization of the networking stack). 2795// 2796// mDNSCoreReceive() is called when a UDP packet is received 2797// 2798// mDNSCoreMachineSleep() is called when the machine sleeps or wakes 2799// (This refers to heavyweight laptop-style sleep/wake that disables network access, 2800// not lightweight second-by-second CPU power management modes.) 2801 2802extern void mDNS_SetFQDN(mDNS *const m); 2803extern mStatus mDNS_RegisterInterface (mDNS *const m, NetworkInterfaceInfo *set, mDNSBool flapping); 2804extern void mDNS_DeregisterInterface(mDNS *const m, NetworkInterfaceInfo *set, mDNSBool flapping); 2805extern void mDNSCoreInitComplete(mDNS *const m, mStatus result); 2806extern void mDNSCoreReceive(mDNS *const m, void *const msg, const mDNSu8 *const end, 2807 const mDNSAddr *const srcaddr, const mDNSIPPort srcport, 2808 const mDNSAddr *const dstaddr, const mDNSIPPort dstport, const mDNSInterfaceID InterfaceID); 2809extern void mDNSCoreMachineSleep(mDNS *const m, mDNSBool wake); 2810 2811extern mDNSBool mDNSAddrIsDNSMulticast(const mDNSAddr *ip); 2812 2813// *************************************************************************** 2814#if 0 2815#pragma mark - Compile-Time assertion checks 2816#endif 2817 2818// Some C compiler cleverness. We can make the compiler check certain things for 2819// us, and report compile-time errors if anything is wrong. The usual way to do 2820// this would be to use a run-time "if" statement, but then you don't find out 2821// what's wrong until you run the software. This way, if the assertion condition 2822// is false, the array size is negative, and the complier complains immediately. 2823 2824struct mDNS_CompileTimeAssertionChecks 2825 { 2826 // Check that the compiler generated our on-the-wire packet format structure definitions 2827 // properly packed, without adding padding bytes to align fields on 32-bit or 64-bit boundaries. 2828 char assert0[(sizeof(rdataSRV) == 262 ) ? 1 : -1]; 2829 char assert1[(sizeof(DNSMessageHeader) == 12 ) ? 1 : -1]; 2830 char assert2[(sizeof(DNSMessage) == 12+AbsoluteMaxDNSMessageData) ? 1 : -1]; 2831 char assert3[(sizeof(mDNSs8) == 1 ) ? 1 : -1]; 2832 char assert4[(sizeof(mDNSu8) == 1 ) ? 1 : -1]; 2833 char assert5[(sizeof(mDNSs16) == 2 ) ? 1 : -1]; 2834 char assert6[(sizeof(mDNSu16) == 2 ) ? 1 : -1]; 2835 char assert7[(sizeof(mDNSs32) == 4 ) ? 1 : -1]; 2836 char assert8[(sizeof(mDNSu32) == 4 ) ? 1 : -1]; 2837 char assert9[(sizeof(mDNSOpaque16) == 2 ) ? 1 : -1]; 2838 char assertA[(sizeof(mDNSOpaque32) == 4 ) ? 1 : -1]; 2839 char assertB[(sizeof(mDNSOpaque128) == 16 ) ? 1 : -1]; 2840 char assertC[(sizeof(CacheRecord ) >= sizeof(CacheGroup) ) ? 1 : -1]; 2841 char assertD[(sizeof(int) >= 4 ) ? 1 : -1]; 2842 }; 2843 2844// *************************************************************************** 2845 2846#ifdef __cplusplus 2847 } 2848#endif 2849 2850#endif 2851