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