mDNSCore/DNSCommon.h

   1 /* -*- Mode: C; tab-width: 4 -*-
   2  *
   3  * Copyright (c) 2002-2003 Apple Computer, Inc. All rights reserved.
   4  *
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at
   8  *
   9  *     http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16
  17     Change History (most recent first):
  18
  19 $Log: DNSCommon.h,v $
  20 svn merge: Revision 1.75  2009/07/21 23:35:01  cheshire
  21 <rdar://problem/6434656> Sleep Proxy: Put owner OPT records in multicast announcements to avoid conflicts
  22 Added PutRR_OS macros to put a ResourceRecord while taking into account the space needed to add an OWNER option at the end
  23
  24 Revision 1.73  2009/04/24 00:28:05  cheshire
  25 <rdar://problem/3476350> Return negative answers when host knows authoritatively that no answer exists
  26 Added definitions for RRTypeAnswersQuestionType/RRAssertsNonexistence/AnyTypeRecordAnswersQuestion
  27
  28 Revision 1.72  2009/04/01 21:12:56  herscher
  29 <rdar://problem/5925472> Current Bonjour code does not compile on Windows
  30
  31 Revision 1.71  2009/04/01 17:50:10  mcguire
  32 cleanup mDNSRandom
  33
  34 Revision 1.70  2009/03/04 00:40:12  cheshire
  35 Updated DNS server error codes to be more consistent with definitions at
  36 <http://www.iana.org/assignments/dns-parameters>
  37
  38 Revision 1.69  2008/11/26 20:57:37  cheshire
  39 For consistency with other similar macros, renamed mdnsIsDigit/mdnsIsLetter/mdnsValidHostChar
  40 to mDNSIsDigit/mDNSIsLetter/mDNSValidHostChar
  41
  42 Revision 1.68  2008/11/14 21:56:31  cheshire
  43 Moved debugging routine ShowTaskSchedulingError() from daemon.c into DNSCommon.c
  44
  45 Revision 1.67  2008/11/13 19:05:09  cheshire
  46 Added definition of LocateOptRR()
  47
  48 Revision 1.66  2008/10/22 19:56:54  cheshire
  49 Removed unused SameRData() macro -- it duplicates the functionality of IdenticalSameNameRecord()
  50
  51 Revision 1.65  2008/10/20 15:39:20  cheshire
  52 Group "#define PutResourceRecord ..." with related definitions
  53
  54 Revision 1.64  2008/10/08 01:03:33  cheshire
  55 Change GetFirstActiveInterface() so the NetworkInterfaceInfo it returns is not "const"
  56
  57 Revision 1.63  2008/09/23 02:30:07  cheshire
  58 Get rid of PutResourceRecordCappedTTL()
  59
  60 Revision 1.62  2008/09/23 02:26:09  cheshire
  61 Don't need to export putEmptyResourceRecord (it's only used from DNSCommon.c)
  62
  63 Revision 1.61  2008/08/13 00:47:53  mcguire
  64 Handle failures when packet logging
  65
  66 Revision 1.60  2008/07/24 20:23:03  cheshire
  67 <rdar://problem/3988320> Should use randomized source ports and transaction IDs to avoid DNS cache poisoning
  68
  69 Revision 1.59  2008/03/14 19:58:38  mcguire
  70 <rdar://problem/5500969> BTMM: Need ability to identify version of mDNSResponder client
  71 Make sure we add the record when sending LLQ refreshes
  72
  73 Revision 1.58  2008/03/06 21:26:10  cheshire
  74 Moved duplicated STRINGIFY macro from individual C files to DNSCommon.h
  75
  76 Revision 1.57  2007/12/13 20:20:17  cheshire
  77 Minor efficiency tweaks -- converted IdenticalResourceRecord, IdenticalSameNameRecord, and
  78 SameRData from functions to macros, which allows the code to be inlined (the compiler can't
  79 inline a function defined in a different compilation unit) and therefore optimized better.
  80
  81 Revision 1.56  2007/12/13 00:13:03  cheshire
  82 Simplified RDataHashValue to take a single ResourceRecord pointer, instead of separate rdlength and RDataBody
  83
  84 Revision 1.55  2007/12/13 00:09:28  cheshire
  85 For completeness added MX, AFSDB, RT, KX to list of RRTYPES that are considered to have a target domainname in their rdata
  86
  87 Revision 1.54  2007/10/05 17:56:10  cheshire
  88 Move CountLabels and SkipLeadingLabels to DNSCommon.c so they're callable from other files
  89
  90 Revision 1.53  2007/09/27 17:42:49  cheshire
  91 Fix naming: for consistency, "kDNSFlag1_RC" should be "kDNSFlag1_RC_Mask"
  92
  93 Revision 1.52  2007/09/26 00:49:46  cheshire
  94 Improve packet logging to show sent and received packets,
  95 transport protocol (UDP/TCP/TLS) and source/destination address:port
  96
  97 Revision 1.51  2007/09/21 21:12:36  cheshire
  98 <rdar://problem/5498009> BTMM: Need to log updates and query packet contents
  99
 100 Revision 1.50  2007/09/20 01:12:06  cheshire
 101 Moved HashSlot(X) from mDNS.c to DNSCommon.h so it's usable in other files
 102
 103 Revision 1.49  2007/08/30 00:31:20  cheshire
 104 Improve "locking failure" debugging messages to show function name using __func__ macro
 105
 106 Revision 1.48  2007/05/25 00:25:44  cheshire
 107 <rdar://problem/5227737> Need to enhance putRData to output all current known types
 108
 109 Revision 1.47  2007/05/01 21:46:31  cheshire
 110 Move GetLLQOptData/GetPktLease from uDNS.c into DNSCommon.c so that dnsextd can use them
 111
 112 Revision 1.46  2007/04/22 20:18:10  cheshire
 113 Add comment about mDNSRandom()
 114
 115 Revision 1.45  2007/04/22 06:02:02  cheshire
 116 <rdar://problem/4615977> Query should immediately return failure when no server
 117
 118 Revision 1.44  2007/03/28 01:20:05  cheshire
 119 <rdar://problem/4883206> Improve/create logging for secure browse
 120
 121 Revision 1.43  2007/03/20 17:07:15  cheshire
 122 Rename "struct uDNS_TCPSocket_struct" to "TCPSocket", "struct uDNS_UDPSocket_struct" to "UDPSocket"
 123
 124 Revision 1.42  2007/03/10 03:26:44  cheshire
 125 <rdar://problem/4961667> uDNS: LLQ refresh response packet causes cached records to be removed from cache
 126
 127 Revision 1.41  2007/01/18 23:18:17  cheshire
 128 Source code tidying: Delete extraneous white space
 129
 130 Revision 1.40  2007/01/05 08:30:40  cheshire
 131 Trim excessive "$Log" checkin history from before 2006
 132 (checkin history still available via "cvs log ..." of course)
 133
 134 Revision 1.39  2007/01/04 21:45:20  cheshire
 135 Added mDNS_DropLockBeforeCallback/mDNS_ReclaimLockAfterCallback macros,
 136 to do additional lock sanity checking around callback invocations
 137
 138 Revision 1.38  2006/12/22 20:59:49  cheshire
 139 <rdar://problem/4742742> Read *all* DNS keys from keychain,
 140  not just key for the system-wide default registration domain
 141
 142 Revision 1.37  2006/08/14 23:24:22  cheshire
 143 Re-licensed mDNSResponder daemon source code under Apache License, Version 2.0
 144
 145 Revision 1.36  2006/07/05 22:56:07  cheshire
 146 <rdar://problem/4472014> Add Private DNS client functionality to mDNSResponder
 147 Update mDNSSendDNSMessage() to use uDNS_TCPSocket type instead of "int"
 148
 149 Revision 1.35  2006/06/29 07:42:14  cheshire
 150 <rdar://problem/3922989> Performance: Remove unnecessary SameDomainName() checks
 151
 152 Revision 1.34  2006/03/18 21:47:56  cheshire
 153 <rdar://problem/4073825> Improve logic for delaying packets after repeated interface transitions
 154
 155 Revision 1.33  2006/03/10 21:51:41  cheshire
 156 <rdar://problem/4111464> After record update, old record sometimes remains in cache
 157 Split out SameRDataBody() into a separate routine so it can be called from other code
 158
 159 */
 160
 161 #ifndef __DNSCOMMON_H_
 162 #define __DNSCOMMON_H_
 163
 164 #include "mDNSEmbeddedAPI.h"
 165
 166 #ifdef  __cplusplus
 167         extern "C" {
 168 #endif
 169
 170 //*************************************************************************************************************
 171 // Macros
 172
 173 // Note: The C preprocessor stringify operator ('#') makes a string from its argument, without macro expansion
 174 // e.g. If "version" is #define'd to be "4", then STRINGIFY_AWE(version) will return the string "version", not "4"
 175 // To expand "version" to its value before making the string, use STRINGIFY(version) instead
 176 #define STRINGIFY_ARGUMENT_WITHOUT_EXPANSION(s) #s
 177 #define STRINGIFY(s) STRINGIFY_ARGUMENT_WITHOUT_EXPANSION(s)
 178
 179 // ***************************************************************************
 180 #if COMPILER_LIKES_PRAGMA_MARK
 181 #pragma mark - DNS Protocol Constants
 182 #endif
 183
 184 typedef enum
 185         {
 186         kDNSFlag0_QR_Mask     = 0x80,           // Query or response?
 187         kDNSFlag0_QR_Query    = 0x00,
 188         kDNSFlag0_QR_Response = 0x80,
 189
 190         kDNSFlag0_OP_Mask     = 0x78,           // Operation type
 191         kDNSFlag0_OP_StdQuery = 0x00,
 192         kDNSFlag0_OP_Iquery   = 0x08,
 193         kDNSFlag0_OP_Status   = 0x10,
 194         kDNSFlag0_OP_Unused3  = 0x18,
 195         kDNSFlag0_OP_Notify   = 0x20,
 196         kDNSFlag0_OP_Update   = 0x28,
 197
 198         kDNSFlag0_QROP_Mask   = kDNSFlag0_QR_Mask | kDNSFlag0_OP_Mask,
 199
 200         kDNSFlag0_AA          = 0x04,           // Authoritative Answer?
 201         kDNSFlag0_TC          = 0x02,           // Truncated?
 202         kDNSFlag0_RD          = 0x01,           // Recursion Desired?
 203         kDNSFlag1_RA          = 0x80,           // Recursion Available?
 204
 205         kDNSFlag1_Zero        = 0x40,           // Reserved; must be zero
 206         kDNSFlag1_AD          = 0x20,           // Authentic Data [RFC 2535]
 207         kDNSFlag1_CD          = 0x10,           // Checking Disabled [RFC 2535]
 208
 209         kDNSFlag1_RC_Mask     = 0x0F,           // Response code
 210         kDNSFlag1_RC_NoErr    = 0x00,
 211         kDNSFlag1_RC_FormErr  = 0x01,
 212         kDNSFlag1_RC_ServFail = 0x02,
 213         kDNSFlag1_RC_NXDomain = 0x03,
 214         kDNSFlag1_RC_NotImpl  = 0x04,
 215         kDNSFlag1_RC_Refused  = 0x05,
 216         kDNSFlag1_RC_YXDomain = 0x06,
 217         kDNSFlag1_RC_YXRRSet  = 0x07,
 218         kDNSFlag1_RC_NXRRSet  = 0x08,
 219         kDNSFlag1_RC_NotAuth  = 0x09,
 220         kDNSFlag1_RC_NotZone  = 0x0A
 221         } DNS_Flags;
 222
 223 typedef enum
 224         {
 225         TSIG_ErrBadSig  = 16,
 226         TSIG_ErrBadKey  = 17,
 227         TSIG_ErrBadTime = 18
 228         } TSIG_ErrorCode;
 229
 230 // ***************************************************************************
 231 #if COMPILER_LIKES_PRAGMA_MARK
 232 #pragma mark -
 233 #pragma mark - General Utility Functions
 234 #endif
 235
 236 extern NetworkInterfaceInfo *GetFirstActiveInterface(NetworkInterfaceInfo *intf);
 237 extern mDNSInterfaceID GetNextActiveInterfaceID(const NetworkInterfaceInfo *intf);
 238
 239 extern mDNSu32 mDNSRandom(mDNSu32 max);         // Returns pseudo-random result from zero to max inclusive
 240
 241 // ***************************************************************************
 242 #if COMPILER_LIKES_PRAGMA_MARK
 243 #pragma mark -
 244 #pragma mark - Domain Name Utility Functions
 245 #endif
 246
 247 #define mDNSIsDigit(X)     ((X) >= '0' && (X) <= '9')
 248 #define mDNSIsUpperCase(X) ((X) >= 'A' && (X) <= 'Z')
 249 #define mDNSIsLowerCase(X) ((X) >= 'a' && (X) <= 'z')
 250 #define mDNSIsLetter(X)    (mDNSIsUpperCase(X) || mDNSIsLowerCase(X))
 251
 252 #define mDNSValidHostChar(X, notfirst, notlast) (mDNSIsLetter(X) || mDNSIsDigit(X) || ((notfirst) && (notlast) && (X) == '-') )
 253
 254 extern mDNSu16 CompressedDomainNameLength(const domainname *const name, const domainname *parent);
 255 extern int CountLabels(const domainname *d);
 256 extern const domainname *SkipLeadingLabels(const domainname *d, int skip);
 257
 258 extern mDNSu32 TruncateUTF8ToLength(mDNSu8 *string, mDNSu32 length, mDNSu32 max);
 259 extern mDNSBool LabelContainsSuffix(const domainlabel *const name, const mDNSBool RichText);
 260 extern mDNSu32 RemoveLabelSuffix(domainlabel *name, mDNSBool RichText);
 261 extern void AppendLabelSuffix(domainlabel *name, mDNSu32 val, mDNSBool RichText);
 262 #define ValidateDomainName(N) (DomainNameLength(N) <= MAX_DOMAIN_NAME)
 263
 264 // ***************************************************************************
 265 #if COMPILER_LIKES_PRAGMA_MARK
 266 #pragma mark -
 267 #pragma mark - Resource Record Utility Functions
 268 #endif
 269
 270 // IdenticalResourceRecord returns true if two resources records have
 271 // the same name, type, class, and identical rdata (InterfaceID and TTL may differ)
 272
 273 // IdenticalSameNameRecord is the same, except it skips the expensive SameDomainName() check,
 274 // which is at its most expensive and least useful in cases where we know in advance that the names match
 275
 276 // Note: The dominant use of IdenticalResourceRecord is from ProcessQuery(), handling known-answer lists. In this case
 277 // it's common to have a whole bunch or records with exactly the same name (e.g. "_http._tcp.local") but different RDATA.
 278 // The SameDomainName() check is expensive when the names match, and in this case *all* the names match, so we
 279 // used to waste a lot of CPU time verifying that the names match, only then to find that the RDATA is different.
 280 // We observed mDNSResponder spending 30% of its total CPU time on this single task alone.
 281 // By swapping the checks so that we check the RDATA first, we can quickly detect when it's different
 282 // (99% of the time) and then bail out before we waste time on the expensive SameDomainName() check.
 283
 284 #define IdenticalResourceRecord(r1,r2) ( \
 285         (r1)->rrtype    == (r2)->rrtype      && \
 286         (r1)->rrclass   == (r2)->rrclass     && \
 287         (r1)->namehash  == (r2)->namehash    && \
 288         (r1)->rdlength  == (r2)->rdlength    && \
 289         (r1)->rdatahash == (r2)->rdatahash   && \
 290         SameRDataBody((r1), &(r2)->rdata->u) && \
 291         SameDomainName((r1)->name, (r2)->name))
 292
 293 #define IdenticalSameNameRecord(r1,r2) ( \
 294         (r1)->rrtype    == (r2)->rrtype      && \
 295         (r1)->rrclass   == (r2)->rrclass     && \
 296         (r1)->rdlength  == (r2)->rdlength    && \
 297         (r1)->rdatahash == (r2)->rdatahash   && \
 298         SameRDataBody((r1), &(r2)->rdata->u))
 299
 300 // A given RRType answers a QuestionType if RRType is CNAME, or types match, or QuestionType is ANY,
 301 // or the RRType is NSEC and positively asserts the nonexistence of the type being requested
 302 #define RRTypeAnswersQuestionType(R,T) ((R)->rrtype == kDNSType_CNAME || (R)->rrtype == (T) || (T) == kDNSQType_ANY || RRAssertsNonexistence((R),(T)))
 303 #define RRAssertsNonexistence(R,T) ((R)->rrtype == kDNSType_NSEC && (T) < kDNSQType_ANY && !((R)->rdata->u.nsec.bitmap[(T)>>3] & (128 >> ((T)&7))))
 304
 305 extern mDNSu32 RDataHashValue(const ResourceRecord *const rr);
 306 extern mDNSBool SameRDataBody(const ResourceRecord *const r1, const RDataBody *const r2);
 307 extern mDNSBool SameNameRecordAnswersQuestion(const ResourceRecord *const rr, const DNSQuestion *const q);
 308 extern mDNSBool ResourceRecordAnswersQuestion(const ResourceRecord *const rr, const DNSQuestion *const q);
 309 extern mDNSBool AnyTypeRecordAnswersQuestion (const ResourceRecord *const rr, const DNSQuestion *const q);
 310 extern mDNSu16 GetRDLength(const ResourceRecord *const rr, mDNSBool estimate);
 311 extern mDNSBool ValidateRData(const mDNSu16 rrtype, const mDNSu16 rdlength, const RData *const rd);
 312
 313 #define GetRRDomainNameTarget(RR) (                                                                          \
 314         ((RR)->rrtype == kDNSType_NS || (RR)->rrtype == kDNSType_CNAME || (RR)->rrtype == kDNSType_PTR || (RR)->rrtype == kDNSType_DNAME) ? &(RR)->rdata->u.name        : \
 315         ((RR)->rrtype == kDNSType_MX || (RR)->rrtype == kDNSType_AFSDB || (RR)->rrtype == kDNSType_RT  || (RR)->rrtype == kDNSType_KX   ) ? &(RR)->rdata->u.mx.exchange : \
 316         ((RR)->rrtype == kDNSType_SRV                                  ) ? &(RR)->rdata->u.srv.target : mDNSNULL )
 317
 318 #define LocalRecordReady(X) ((X)->resrec.RecordType != kDNSRecordTypeUnique && (X)->resrec.RecordType != kDNSRecordTypeDeregistering)
 319
 320 // ***************************************************************************
 321 #if COMPILER_LIKES_PRAGMA_MARK
 322 #pragma mark -
 323 #pragma mark - DNS Message Creation Functions
 324 #endif
 325
 326 extern void InitializeDNSMessage(DNSMessageHeader *h, mDNSOpaque16 id, mDNSOpaque16 flags);
 327 extern const mDNSu8 *FindCompressionPointer(const mDNSu8 *const base, const mDNSu8 *const end, const mDNSu8 *const domname);
 328 extern mDNSu8 *putDomainNameAsLabels(const DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, const domainname *const name);
 329 extern mDNSu8 *putRData(const DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, const ResourceRecord *const rr);
 330
 331 // If we have a single large record to put in the packet, then we allow the packet to be up to 9K bytes,
 332 // but in the normal case we try to keep the packets below 1500 to avoid IP fragmentation on standard Ethernet
 333
 334 #define AllowedRRSpace(msg) (((msg)->h.numAnswers || (msg)->h.numAuthorities || (msg)->h.numAdditionals) ? NormalMaxDNSMessageData : AbsoluteMaxDNSMessageData)
 335
 336 extern mDNSu8 *PutResourceRecordTTLWithLimit(DNSMessage *const msg, mDNSu8 *ptr, mDNSu16 *count, ResourceRecord *rr, mDNSu32 ttl, const mDNSu8 *limit);
 337
 338 #define PutResourceRecordTTL(msg, ptr, count, rr, ttl) \
 339         PutResourceRecordTTLWithLimit((msg), (ptr), (count), (rr), (ttl), (msg)->data + AllowedRRSpace(msg))
 340
 341 #define PutResourceRecordTTLJumbo(msg, ptr, count, rr, ttl) \
 342         PutResourceRecordTTLWithLimit((msg), (ptr), (count), (rr), (ttl), (msg)->data + AbsoluteMaxDNSMessageData)
 343
 344 #define PutResourceRecord(MSG, P, C, RR) PutResourceRecordTTL((MSG), (P), (C), (RR), (RR)->rroriginalttl)
 345
 346 // The PutRR_OS variants assume a local variable 'm', put build the packet at m->omsg,
 347 // and assume a local variable 'OwnerRecordSpace' indicating how many bytes (if any) to reserve to add an OWNER option at the end
 348 #define PutRR_OS_TTL(ptr, count, rr, ttl) \
 349         PutResourceRecordTTLWithLimit(&m->omsg, (ptr), (count), (rr), (ttl), m->omsg.data + AllowedRRSpace(&m->omsg) - OwnerRecordSpace)
 350
 351 #define PutRR_OS(P, C, RR) PutRR_OS_TTL((P), (C), (RR), (RR)->rroriginalttl)
 352
 353 extern mDNSu8 *putQuestion(DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, const domainname *const name, mDNSu16 rrtype, mDNSu16 rrclass);
 354 extern mDNSu8 *putZone(DNSMessage *const msg, mDNSu8 *ptr, mDNSu8 *limit, const domainname *zone, mDNSOpaque16 zoneClass);
 355 extern mDNSu8 *putPrereqNameNotInUse(const domainname *const name, DNSMessage *msg, mDNSu8 *ptr, mDNSu8 *end);
 356 extern mDNSu8 *putDeletionRecord(DNSMessage *msg, mDNSu8 *ptr, ResourceRecord *rr);
 357 extern mDNSu8 *putDeleteRRSet(DNSMessage *msg, mDNSu8 *ptr, const domainname *name, mDNSu16 rrtype);
 358 extern mDNSu8 *putDeleteAllRRSets(DNSMessage *msg, mDNSu8 *ptr, const domainname *name);
 359 extern mDNSu8 *putUpdateLease(DNSMessage *msg, mDNSu8 *end, mDNSu32 lease);
 360
 361 extern mDNSu8 *putHINFO(const mDNS *const m, DNSMessage *const msg, mDNSu8 *end, DomainAuthInfo *authInfo);
 362
 363 // ***************************************************************************
 364 #if COMPILER_LIKES_PRAGMA_MARK
 365 #pragma mark -
 366 #pragma mark - DNS Message Parsing Functions
 367 #endif
 368
 369 #define HashSlot(X) (DomainNameHashValue(X) % CACHE_HASH_SLOTS)
 370 extern mDNSu32 DomainNameHashValue(const domainname *const name);
 371 extern void SetNewRData(ResourceRecord *const rr, RData *NewRData, mDNSu16 rdlength);
 372 extern const mDNSu8 *skipDomainName(const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *const end);
 373 extern const mDNSu8 *getDomainName(const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *const end,
 374         domainname *const name);
 375 extern const mDNSu8 *skipResourceRecord(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end);
 376 extern const mDNSu8 *GetLargeResourceRecord(mDNS *const m, const DNSMessage * const msg, const mDNSu8 *ptr,
 377     const mDNSu8 * end, const mDNSInterfaceID InterfaceID, mDNSu8 RecordType, LargeCacheRecord *largecr);
 378 extern const mDNSu8 *skipQuestion(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end);
 379 extern const mDNSu8 *getQuestion(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end, const mDNSInterfaceID InterfaceID,
 380         DNSQuestion *question);
 381 extern const mDNSu8 *LocateAnswers(const DNSMessage *const msg, const mDNSu8 *const end);
 382 extern const mDNSu8 *LocateAuthorities(const DNSMessage *const msg, const mDNSu8 *const end);
 383 extern const mDNSu8 *LocateAdditionals(const DNSMessage *const msg, const mDNSu8 *const end);
 384 extern const mDNSu8 *LocateOptRR(const DNSMessage *const msg, const mDNSu8 *const end, int minsize);
 385 extern const rdataOPT *GetLLQOptData(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end);
 386 extern mDNSu32 GetPktLease(mDNS *m, DNSMessage *msg, const mDNSu8 *end);
 387 extern void DumpPacket(mDNS *const m, mStatus status, mDNSBool sent, char *transport,
 388         const mDNSAddr *srcaddr, mDNSIPPort srcport,
 389         const mDNSAddr *dstaddr, mDNSIPPort dstport, const DNSMessage *const msg, const mDNSu8 *const end);
 390
 391 // ***************************************************************************
 392 #if COMPILER_LIKES_PRAGMA_MARK
 393 #pragma mark -
 394 #pragma mark - Packet Sending Functions
 395 #endif
 396
 397 extern mStatus mDNSSendDNSMessage(mDNS *const m, DNSMessage *const msg, mDNSu8 *end,
 398         mDNSInterfaceID InterfaceID, UDPSocket *src, const mDNSAddr *dst, mDNSIPPort dstport, TCPSocket *sock, DomainAuthInfo *authInfo);
 399
 400 // ***************************************************************************
 401 #if COMPILER_LIKES_PRAGMA_MARK
 402 #pragma mark -
 403 #pragma mark - RR List Management & Task Management
 404 #endif
 405
 406 extern void ShowTaskSchedulingError(mDNS *const m);
 407 extern void mDNS_Lock_(mDNS *const m);
 408 extern void mDNS_Unlock_(mDNS *const m);
 409
 410 #if defined(_WIN32)
 411  #define __func__ __FUNCTION__
 412 #endif
 413
 414 #define mDNS_Lock(X) do { \
 415         if ((X)->mDNS_busy != (X)->mDNS_reentrancy) LogMsg("%s: mDNS_Lock locking failure! mDNS_busy (%ld) != mDNS_reentrancy (%ld)", __func__, (X)->mDNS_busy, (X)->mDNS_reentrancy); \
 416         mDNS_Lock_(X); } while (0)
 417
 418 #define mDNS_Unlock(X) do { mDNS_Unlock_(X); \
 419         if ((X)->mDNS_busy != (X)->mDNS_reentrancy) LogMsg("%s: mDNS_Unlock locking failure! mDNS_busy (%ld) != mDNS_reentrancy (%ld)", __func__, (X)->mDNS_busy, (X)->mDNS_reentrancy); \
 420         } while (0)
 421
 422 #define mDNS_DropLockBeforeCallback() do { m->mDNS_reentrancy++; \
 423         if (m->mDNS_busy != m->mDNS_reentrancy) LogMsg("%s: Locking Failure! mDNS_busy (%ld) != mDNS_reentrancy (%ld)", __func__, m->mDNS_busy, m->mDNS_reentrancy); \
 424         } while (0)
 425
 426 #define mDNS_ReclaimLockAfterCallback() do { \
 427         if (m->mDNS_busy != m->mDNS_reentrancy) LogMsg("%s: Unlocking Failure! mDNS_busy (%ld) != mDNS_reentrancy (%ld)", __func__, m->mDNS_busy, m->mDNS_reentrancy); \
 428         m->mDNS_reentrancy--; } while (0)
 429
 430 #ifdef  __cplusplus
 431         }
 432 #endif
 433
 434 #endif // __DNSCOMMON_H_