mDNSCore/DNSCommon.h

   1 /*
   2  * Copyright (c) 2002-2003 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: DNSCommon.h,v $
  26 Revision 1.33  2006/03/10 21:51:41  cheshire
  27 <rdar://problem/4111464> After record update, old record sometimes remains in cache
  28 Split out SameRDataBody() into a separate routine so it can be called from other code
  29
  30 Revision 1.32  2005/03/21 00:33:51  shersche
  31 <rdar://problem/4021486> Fix build warnings on Win32 platform
  32
  33 Revision 1.31  2005/02/18 00:43:11  cheshire
  34 <rdar://problem/4010245> mDNSResponder should auto-truncate service names that are too long
  35
  36 Revision 1.30  2005/01/19 03:12:44  cheshire
  37 Move LocalRecordReady() macro from mDNS.c to DNSCommon.h
  38
  39 Revision 1.29  2004/12/15 02:11:22  ksekar
  40 <rdar://problem/3917317> Don't check for Dynamic DNS hostname uniqueness
  41
  42 Revision 1.28  2004/12/06 21:15:22  ksekar
  43 <rdar://problem/3884386> mDNSResponder crashed in CheckServiceRegistrations
  44
  45 Revision 1.27  2004/12/03 07:20:50  ksekar
  46 <rdar://problem/3674208> Wide-Area: Registration of large TXT record fails
  47
  48 Revision 1.26  2004/12/03 05:18:33  ksekar
  49 <rdar://problem/3810596> mDNSResponder needs to return more specific TSIG errors
  50
  51 Revision 1.25  2004/10/26 03:52:02  cheshire
  52 Update checkin comments
  53
  54 Revision 1.24  2004/10/23 01:16:00  cheshire
  55 <rdar://problem/3851677> uDNS operations not always reliable on multi-homed hosts
  56
  57 Revision 1.23  2004/10/03 23:18:58  cheshire
  58 Move address comparison macros from DNSCommon.h to mDNSEmbeddedAPI.h
  59
  60 Revision 1.22  2004/09/30 00:24:56  ksekar
  61 <rdar://problem/3695802> Dynamically update default registration domains on config change
  62
  63 Revision 1.21  2004/09/17 01:08:48  cheshire
  64 Renamed mDNSClientAPI.h to mDNSEmbeddedAPI.h
  65   The name "mDNSClientAPI.h" is misleading to new developers looking at this code. The interfaces
  66   declared in that file are ONLY appropriate to single-address-space embedded applications.
  67   For clients on general-purpose computers, the interfaces defined in dns_sd.h should be used.
  68
  69 Revision 1.20  2004/09/17 00:49:51  cheshire
  70 Get rid of now-unused GetResourceRecord -- the correct (safe) routine to use
  71 is GetLargeResourceRecord
  72
  73 Revision 1.19  2004/09/16 21:59:15  cheshire
  74 For consistency with zerov6Addr, rename zeroIPAddr to zerov4Addr
  75
  76 Revision 1.18  2004/09/16 02:29:39  cheshire
  77 Moved mDNS_Lock/mDNS_Unlock to DNSCommon.c; Added necessary locking around
  78 uDNS_ReceiveMsg, uDNS_StartQuery, uDNS_UpdateRecord, uDNS_RegisterService
  79
  80 Revision 1.17  2004/09/14 23:27:46  cheshire
  81 Fix compile errors
  82
  83 Revision 1.16  2004/08/13 23:46:58  cheshire
  84 "asyncronous" -> "asynchronous"
  85
  86 Revision 1.15  2004/08/10 23:19:14  ksekar
  87 <rdar://problem/3722542>: DNS Extension daemon for Wide Area Service Discovery
  88 Moved routines/constants to allow extern access for garbage collection daemon
  89
  90 Revision 1.14  2004/05/28 23:42:36  ksekar
  91 <rdar://problem/3258021>: Feature: DNS server->client notification on record changes (#7805)
  92
  93 Revision 1.13  2004/05/18 23:51:25  cheshire
  94 Tidy up all checkin comments to use consistent "<rdar://problem/xxxxxxx>" format for bug numbers
  95
  96 Revision 1.12  2004/04/22 04:03:59  cheshire
  97 Headers should use "extern" declarations, not "mDNSexport"
  98
  99 Revision 1.11  2004/04/14 23:09:28  ksekar
 100 Support for TSIG signed dynamic updates.
 101
 102 Revision 1.10  2004/03/13 01:57:33  ksekar
 103 <rdar://problem/3192546>: DynDNS: Dynamic update of service records
 104
 105 Revision 1.9  2004/02/21 08:56:58  bradley
 106 Wrap prototypes with extern "C" for C++ builds.
 107
 108 Revision 1.8  2004/02/06 23:04:18  ksekar
 109 Basic Dynamic Update support via mDNS_Register (dissabled via
 110 UNICAST_REGISTRATION #define)
 111
 112 Revision 1.7  2004/02/03 19:47:36  ksekar
 113 Added an asynchronous state machine mechanism to uDNS.c, including
 114 calls to find the parent zone for a domain name.  Changes include code
 115 in repository previously dissabled via "#if 0 incomplete".  Codepath
 116 is currently unused, and will be called to create update records, etc.
 117
 118 Revision 1.6  2004/01/27 20:15:22  cheshire
 119 <rdar://problem/3541288>: Time to prune obsolete code for listening on port 53
 120
 121 Revision 1.5  2004/01/24 03:40:56  cheshire
 122 Move mDNSAddrIsDNSMulticast() from DNSCommon.h to mDNSEmbeddedAPI.h so embedded clients can use it
 123
 124 Revision 1.4  2004/01/24 03:38:27  cheshire
 125 Fix minor syntactic error: Headers should use "extern" declarations, not "mDNSexport"
 126
 127 Revision 1.3  2004/01/23 23:23:14  ksekar
 128 Added TCP support for truncated unicast messages.
 129
 130 Revision 1.2  2004/01/21 21:12:23  cheshire
 131 Add missing newline at end of file to make Unix tools happier
 132
 133 Revision 1.1  2003/12/13 03:05:27  ksekar
 134 <rdar://problem/3192548>: DynDNS: Unicast query of service records
 135
 136
 137  */
 138
 139 #ifndef __DNSCOMMON_H_
 140 #define __DNSCOMMON_H_
 141
 142 #include "mDNSEmbeddedAPI.h"
 143
 144 #ifdef  __cplusplus
 145         extern "C" {
 146 #endif
 147
 148 // ***************************************************************************
 149 #if COMPILER_LIKES_PRAGMA_MARK
 150 #pragma mark - DNS Protocol Constants
 151 #endif
 152
 153 typedef enum
 154         {
 155         kDNSFlag0_QR_Mask     = 0x80,           // Query or response?
 156         kDNSFlag0_QR_Query    = 0x00,
 157         kDNSFlag0_QR_Response = 0x80,
 158
 159         kDNSFlag0_OP_Mask     = 0x78,           // Operation type
 160         kDNSFlag0_OP_StdQuery = 0x00,
 161         kDNSFlag0_OP_Iquery   = 0x08,
 162         kDNSFlag0_OP_Status   = 0x10,
 163         kDNSFlag0_OP_Unused3  = 0x18,
 164         kDNSFlag0_OP_Notify   = 0x20,
 165         kDNSFlag0_OP_Update   = 0x28,
 166
 167         kDNSFlag0_QROP_Mask   = kDNSFlag0_QR_Mask | kDNSFlag0_OP_Mask,
 168
 169         kDNSFlag0_AA          = 0x04,           // Authoritative Answer?
 170         kDNSFlag0_TC          = 0x02,           // Truncated?
 171         kDNSFlag0_RD          = 0x01,           // Recursion Desired?
 172         kDNSFlag1_RA          = 0x80,           // Recursion Available?
 173
 174         kDNSFlag1_Zero        = 0x40,           // Reserved; must be zero
 175         kDNSFlag1_AD          = 0x20,           // Authentic Data [RFC 2535]
 176         kDNSFlag1_CD          = 0x10,           // Checking Disabled [RFC 2535]
 177
 178         kDNSFlag1_RC          = 0x0F,           // Response code
 179         kDNSFlag1_RC_NoErr    = 0x00,
 180         kDNSFlag1_RC_FmtErr   = 0x01,
 181         kDNSFlag1_RC_SrvErr   = 0x02,
 182         kDNSFlag1_RC_NXDomain = 0x03,
 183         kDNSFlag1_RC_NotImpl  = 0x04,
 184         kDNSFlag1_RC_Refused  = 0x05,
 185         kDNSFlag1_RC_YXDomain = 0x06,
 186         kDNSFlag1_RC_YXRRSet  = 0x07,
 187         kDNSFlag1_RC_NXRRSet  = 0x08,
 188         kDNSFlag1_RC_NotAuth  = 0x09,
 189         kDNSFlag1_RC_NotZone  = 0x0A
 190         } DNS_Flags;
 191
 192 typedef enum
 193         {
 194         TSIG_ErrBadSig  = 16,
 195         TSIG_ErrBadKey  = 17,
 196         TSIG_ErrBadTime = 18
 197         } TSIG_ErrorCode;
 198
 199 // ***************************************************************************
 200 #if COMPILER_LIKES_PRAGMA_MARK
 201 #pragma mark -
 202 #pragma mark - General Utility Functions
 203 #endif
 204
 205 extern const NetworkInterfaceInfo *GetFirstActiveInterface(const NetworkInterfaceInfo *intf);
 206 extern mDNSInterfaceID GetNextActiveInterfaceID(const NetworkInterfaceInfo *intf);
 207
 208 extern mDNSu32 mDNSRandom(mDNSu32 max);
 209
 210
 211 // ***************************************************************************
 212 #if COMPILER_LIKES_PRAGMA_MARK
 213 #pragma mark -
 214 #pragma mark - Domain Name Utility Functions
 215 #endif
 216
 217 #define mdnsIsDigit(X)     ((X) >= '0' && (X) <= '9')
 218 #define mDNSIsUpperCase(X) ((X) >= 'A' && (X) <= 'Z')
 219 #define mDNSIsLowerCase(X) ((X) >= 'a' && (X) <= 'z')
 220 #define mdnsIsLetter(X)    (mDNSIsUpperCase(X) || mDNSIsLowerCase(X))
 221
 222 #define mdnsValidHostChar(X, notfirst, notlast) (mdnsIsLetter(X) || mdnsIsDigit(X) || ((notfirst) && (notlast) && (X) == '-') )
 223
 224 extern mDNSu16 CompressedDomainNameLength(const domainname *const name, const domainname *parent);
 225
 226 extern mDNSu32 TruncateUTF8ToLength(mDNSu8 *string, mDNSu32 length, mDNSu32 max);
 227 extern mDNSBool LabelContainsSuffix(const domainlabel *const name, const mDNSBool RichText);
 228 extern mDNSu32 RemoveLabelSuffix(domainlabel *name, mDNSBool RichText);
 229 extern void AppendLabelSuffix(domainlabel *name, mDNSu32 val, mDNSBool RichText);
 230 extern void mDNS_HostNameCallback(mDNS *const m, AuthRecord *const rr, mStatus result);
 231 #define ValidateDomainName(N) (DomainNameLength(N) <= MAX_DOMAIN_NAME)
 232
 233
 234 // ***************************************************************************
 235 #if COMPILER_LIKES_PRAGMA_MARK
 236 #pragma mark -
 237 #pragma mark - Resource Record Utility Functions
 238 #endif
 239
 240 extern mDNSu32 RDataHashValue(mDNSu16 const rdlength, const RDataBody *const rdb);
 241
 242 extern mDNSBool SameRDataBody(const ResourceRecord *const r1, const RDataBody *const r2);
 243 extern mDNSBool SameRData(const ResourceRecord *const r1, const ResourceRecord *const r2);
 244
 245 extern mDNSBool ResourceRecordAnswersQuestion(const ResourceRecord *const rr, const DNSQuestion *const q);
 246
 247 extern mDNSBool SameResourceRecord(ResourceRecord *r1, ResourceRecord *r2);
 248
 249 extern mDNSu16 GetRDLength(const ResourceRecord *const rr, mDNSBool estimate);
 250
 251 #define GetRRDomainNameTarget(RR) (                                                                          \
 252         ((RR)->rrtype == kDNSType_CNAME || (RR)->rrtype == kDNSType_PTR || (RR)->rrtype == kDNSType_NS)          \
 253                                                                          ? &(RR)->rdata->u.name       :          \
 254         ((RR)->rrtype == kDNSType_SRV                                  ) ? &(RR)->rdata->u.srv.target : mDNSNULL )
 255
 256 extern mDNSBool ValidateRData(const mDNSu16 rrtype, const mDNSu16 rdlength, const RData *const rd);
 257 #define LocalRecordReady(X) ((X)->resrec.RecordType != kDNSRecordTypeUnique && (X)->resrec.RecordType != kDNSRecordTypeDeregistering)
 258
 259
 260 // ***************************************************************************
 261 #if COMPILER_LIKES_PRAGMA_MARK
 262 #pragma mark -
 263 #pragma mark -
 264 #pragma mark - DNS Message Creation Functions
 265 #endif
 266
 267 extern void InitializeDNSMessage(DNSMessageHeader *h, mDNSOpaque16 id, mDNSOpaque16 flags);
 268 extern const mDNSu8 *FindCompressionPointer(const mDNSu8 *const base, const mDNSu8 *const end, const mDNSu8 *const domname);
 269
 270 extern mDNSu8 *putDomainNameAsLabels(const DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, const domainname *const name);
 271
 272 extern mDNSu8 *putRData(const DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, ResourceRecord *rr);
 273
 274 // If we have a single large record to put in the packet, then we allow the packet to be up to 9K bytes,
 275 // but in the normal case we try to keep the packets below 1500 to avoid IP fragmentation on standard Ethernet
 276
 277 extern mDNSu8 *PutResourceRecordTTLWithLimit(DNSMessage *const msg, mDNSu8 *ptr, mDNSu16 *count, ResourceRecord *rr, mDNSu32 ttl, const mDNSu8 *limit);
 278
 279 #define PutResourceRecordTTL(msg, ptr, count, rr, ttl) PutResourceRecordTTLWithLimit((msg), (ptr), (count), (rr), (ttl), \
 280         ((msg)->h.numAnswers || (msg)->h.numAuthorities || (msg)->h.numAdditionals) ? (msg)->data + NormalMaxDNSMessageData : (msg)->data + AbsoluteMaxDNSMessageData)
 281
 282 #define PutResourceRecordTTLJumbo(msg, ptr, count, rr, ttl) PutResourceRecordTTLWithLimit((msg), (ptr), (count), (rr), (ttl), \
 283         (msg)->data + AbsoluteMaxDNSMessageData)
 284
 285 extern mDNSu8 *PutResourceRecordCappedTTL(DNSMessage *const msg, mDNSu8 *ptr, mDNSu16 *count, ResourceRecord *rr, mDNSu32 maxttl);
 286
 287 extern mDNSu8 *putEmptyResourceRecord(DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, mDNSu16 *count, const AuthRecord *rr);
 288
 289 extern mDNSu8 *putQuestion(DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, const domainname *const name, mDNSu16 rrtype, mDNSu16 rrclass);
 290
 291 extern mDNSu8 *putZone(DNSMessage *const msg, mDNSu8 *ptr, mDNSu8 *limit, const domainname *zone, mDNSOpaque16 zoneClass);
 292
 293 extern mDNSu8 *putPrereqNameNotInUse(domainname *name, DNSMessage *msg, mDNSu8 *ptr, mDNSu8 *end);
 294
 295 extern mDNSu8 *putDeletionRecord(DNSMessage *msg, mDNSu8 *ptr, ResourceRecord *rr);
 296
 297 extern  mDNSu8 *putDeleteRRSet(DNSMessage *msg, mDNSu8 *ptr, const domainname *name, mDNSu16 rrtype);
 298
 299 extern mDNSu8 *putDeleteAllRRSets(DNSMessage *msg, mDNSu8 *ptr, const domainname *name);
 300
 301 extern mDNSu8 *putUpdateLease(DNSMessage *msg, mDNSu8 *end, mDNSu32 lease);
 302
 303 #define PutResourceRecord(MSG, P, C, RR) PutResourceRecordTTL((MSG), (P), (C), (RR), (RR)->rroriginalttl)
 304
 305
 306 // ***************************************************************************
 307 #if COMPILER_LIKES_PRAGMA_MARK
 308 #pragma mark -
 309 #pragma mark - DNS Message Parsing Functions
 310 #endif
 311
 312 extern mDNSu32 DomainNameHashValue(const domainname *const name);
 313
 314 extern void SetNewRData(ResourceRecord *const rr, RData *NewRData, mDNSu16 rdlength);
 315
 316
 317 extern const mDNSu8 *skipDomainName(const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *const end);
 318
 319 extern const mDNSu8 *getDomainName(const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *const end,
 320         domainname *const name);
 321
 322 extern const mDNSu8 *skipResourceRecord(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end);
 323
 324 extern const mDNSu8 *GetLargeResourceRecord(mDNS *const m, const DNSMessage * const msg, const mDNSu8 *ptr,
 325     const mDNSu8 * end, const mDNSInterfaceID InterfaceID, mDNSu8 RecordType, LargeCacheRecord *largecr);
 326
 327 extern const mDNSu8 *skipQuestion(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end);
 328
 329 extern const mDNSu8 *getQuestion(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end, const mDNSInterfaceID InterfaceID,
 330         DNSQuestion *question);
 331
 332 extern const mDNSu8 *LocateAnswers(const DNSMessage *const msg, const mDNSu8 *const end);
 333
 334 extern const mDNSu8 *LocateAuthorities(const DNSMessage *const msg, const mDNSu8 *const end);
 335
 336 extern const mDNSu8 *LocateAdditionals(const DNSMessage *const msg, const mDNSu8 *const end);
 337
 338 // ***************************************************************************
 339 #if COMPILER_LIKES_PRAGMA_MARK
 340 #pragma mark -
 341 #pragma mark -
 342 #pragma mark - Packet Sending Functions
 343 #endif
 344
 345 extern mStatus mDNSSendDNSMessage(const mDNS *const m, DNSMessage *const msg, mDNSu8 *end,
 346         mDNSInterfaceID InterfaceID, const mDNSAddr *dst, mDNSIPPort dstport, int sd, uDNS_AuthInfo *authInfo);
 347
 348 // ***************************************************************************
 349 #if COMPILER_LIKES_PRAGMA_MARK
 350 #pragma mark -
 351 #pragma mark - RR List Management & Task Management
 352 #endif
 353
 354 extern void mDNS_Lock(mDNS *const m);
 355 extern void mDNS_Unlock(mDNS *const m);
 356
 357 #ifdef  __cplusplus
 358         }
 359 #endif
 360
 361 #endif // __DNSCOMMON_H_