mDNSCore/uDNS.c

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