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 Revision 1.34.2.1  2006/08/29 06:24:22  cheshire
  21 Re-licensed mDNSResponder daemon source code under Apache License, Version 2.0
  22
  23 Revision 1.34  2006/03/18 21:47:56  cheshire
  24 <rdar://problem/4073825> Improve logic for delaying packets after repeated interface transitions
  25
  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 // ***************************************************************************
 150 #if COMPILER_LIKES_PRAGMA_MARK
 151 #pragma mark - DNS Protocol Constants
 152 #endif
 153
 154 typedef enum
 155         {
 156         kDNSFlag0_QR_Mask     = 0x80,           // Query or response?
 157         kDNSFlag0_QR_Query    = 0x00,
 158         kDNSFlag0_QR_Response = 0x80,
 159
 160         kDNSFlag0_OP_Mask     = 0x78,           // Operation type
 161         kDNSFlag0_OP_StdQuery = 0x00,
 162         kDNSFlag0_OP_Iquery   = 0x08,
 163         kDNSFlag0_OP_Status   = 0x10,
 164         kDNSFlag0_OP_Unused3  = 0x18,
 165         kDNSFlag0_OP_Notify   = 0x20,
 166         kDNSFlag0_OP_Update   = 0x28,
 167
 168         kDNSFlag0_QROP_Mask   = kDNSFlag0_QR_Mask | kDNSFlag0_OP_Mask,
 169
 170         kDNSFlag0_AA          = 0x04,           // Authoritative Answer?
 171         kDNSFlag0_TC          = 0x02,           // Truncated?
 172         kDNSFlag0_RD          = 0x01,           // Recursion Desired?
 173         kDNSFlag1_RA          = 0x80,           // Recursion Available?
 174
 175         kDNSFlag1_Zero        = 0x40,           // Reserved; must be zero
 176         kDNSFlag1_AD          = 0x20,           // Authentic Data [RFC 2535]
 177         kDNSFlag1_CD          = 0x10,           // Checking Disabled [RFC 2535]
 178
 179         kDNSFlag1_RC          = 0x0F,           // Response code
 180         kDNSFlag1_RC_NoErr    = 0x00,
 181         kDNSFlag1_RC_FmtErr   = 0x01,
 182         kDNSFlag1_RC_SrvErr   = 0x02,
 183         kDNSFlag1_RC_NXDomain = 0x03,
 184         kDNSFlag1_RC_NotImpl  = 0x04,
 185         kDNSFlag1_RC_Refused  = 0x05,
 186         kDNSFlag1_RC_YXDomain = 0x06,
 187         kDNSFlag1_RC_YXRRSet  = 0x07,
 188         kDNSFlag1_RC_NXRRSet  = 0x08,
 189         kDNSFlag1_RC_NotAuth  = 0x09,
 190         kDNSFlag1_RC_NotZone  = 0x0A
 191         } DNS_Flags;
 192
 193 typedef enum
 194         {
 195         TSIG_ErrBadSig  = 16,
 196         TSIG_ErrBadKey  = 17,
 197         TSIG_ErrBadTime = 18
 198         } TSIG_ErrorCode;
 199
 200
 201 // ***************************************************************************
 202 #if COMPILER_LIKES_PRAGMA_MARK
 203 #pragma mark -
 204 #pragma mark - General Utility Functions
 205 #endif
 206
 207 extern const NetworkInterfaceInfo *GetFirstActiveInterface(const NetworkInterfaceInfo *intf);
 208 extern mDNSInterfaceID GetNextActiveInterfaceID(const NetworkInterfaceInfo *intf);
 209
 210 extern mDNSu32 mDNSRandom(mDNSu32 max);
 211 extern mDNSu32 mDNSRandomFromFixedSeed(mDNSu32 seed, mDNSu32 max);
 212
 213
 214 // ***************************************************************************
 215 #if COMPILER_LIKES_PRAGMA_MARK
 216 #pragma mark -
 217 #pragma mark - Domain Name Utility Functions
 218 #endif
 219
 220 #define mdnsIsDigit(X)     ((X) >= '0' && (X) <= '9')
 221 #define mDNSIsUpperCase(X) ((X) >= 'A' && (X) <= 'Z')
 222 #define mDNSIsLowerCase(X) ((X) >= 'a' && (X) <= 'z')
 223 #define mdnsIsLetter(X)    (mDNSIsUpperCase(X) || mDNSIsLowerCase(X))
 224
 225 #define mdnsValidHostChar(X, notfirst, notlast) (mdnsIsLetter(X) || mdnsIsDigit(X) || ((notfirst) && (notlast) && (X) == '-') )
 226
 227 extern mDNSu16 CompressedDomainNameLength(const domainname *const name, const domainname *parent);
 228
 229 extern mDNSu32 TruncateUTF8ToLength(mDNSu8 *string, mDNSu32 length, mDNSu32 max);
 230 extern mDNSBool LabelContainsSuffix(const domainlabel *const name, const mDNSBool RichText);
 231 extern mDNSu32 RemoveLabelSuffix(domainlabel *name, mDNSBool RichText);
 232 extern void AppendLabelSuffix(domainlabel *name, mDNSu32 val, mDNSBool RichText);
 233 extern void mDNS_HostNameCallback(mDNS *const m, AuthRecord *const rr, mStatus result);
 234 #define ValidateDomainName(N) (DomainNameLength(N) <= MAX_DOMAIN_NAME)
 235
 236
 237 // ***************************************************************************
 238 #if COMPILER_LIKES_PRAGMA_MARK
 239 #pragma mark -
 240 #pragma mark - Resource Record Utility Functions
 241 #endif
 242
 243 extern mDNSu32 RDataHashValue(mDNSu16 const rdlength, const RDataBody *const rdb);
 244
 245 extern mDNSBool SameRDataBody(const ResourceRecord *const r1, const RDataBody *const r2);
 246 extern mDNSBool SameRData(const ResourceRecord *const r1, const ResourceRecord *const r2);
 247
 248 extern mDNSBool ResourceRecordAnswersQuestion(const ResourceRecord *const rr, const DNSQuestion *const q);
 249
 250 extern mDNSBool SameResourceRecord(ResourceRecord *r1, ResourceRecord *r2);
 251
 252 extern mDNSu16 GetRDLength(const ResourceRecord *const rr, mDNSBool estimate);
 253
 254 #define GetRRDomainNameTarget(RR) (                                                                          \
 255         ((RR)->rrtype == kDNSType_CNAME || (RR)->rrtype == kDNSType_PTR || (RR)->rrtype == kDNSType_NS)          \
 256                                                                          ? &(RR)->rdata->u.name       :          \
 257         ((RR)->rrtype == kDNSType_SRV                                  ) ? &(RR)->rdata->u.srv.target : mDNSNULL )
 258
 259 extern mDNSBool ValidateRData(const mDNSu16 rrtype, const mDNSu16 rdlength, const RData *const rd);
 260 #define LocalRecordReady(X) ((X)->resrec.RecordType != kDNSRecordTypeUnique && (X)->resrec.RecordType != kDNSRecordTypeDeregistering)
 261
 262
 263 // ***************************************************************************
 264 #if COMPILER_LIKES_PRAGMA_MARK
 265 #pragma mark -
 266 #pragma mark -
 267 #pragma mark - DNS Message Creation Functions
 268 #endif
 269
 270 extern void InitializeDNSMessage(DNSMessageHeader *h, mDNSOpaque16 id, mDNSOpaque16 flags);
 271 extern const mDNSu8 *FindCompressionPointer(const mDNSu8 *const base, const mDNSu8 *const end, const mDNSu8 *const domname);
 272
 273 extern mDNSu8 *putDomainNameAsLabels(const DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, const domainname *const name);
 274
 275 extern mDNSu8 *putRData(const DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, ResourceRecord *rr);
 276
 277 // If we have a single large record to put in the packet, then we allow the packet to be up to 9K bytes,
 278 // but in the normal case we try to keep the packets below 1500 to avoid IP fragmentation on standard Ethernet
 279
 280 extern mDNSu8 *PutResourceRecordTTLWithLimit(DNSMessage *const msg, mDNSu8 *ptr, mDNSu16 *count, ResourceRecord *rr, mDNSu32 ttl, const mDNSu8 *limit);
 281
 282 #define PutResourceRecordTTL(msg, ptr, count, rr, ttl) PutResourceRecordTTLWithLimit((msg), (ptr), (count), (rr), (ttl), \
 283         ((msg)->h.numAnswers || (msg)->h.numAuthorities || (msg)->h.numAdditionals) ? (msg)->data + NormalMaxDNSMessageData : (msg)->data + AbsoluteMaxDNSMessageData)
 284
 285 #define PutResourceRecordTTLJumbo(msg, ptr, count, rr, ttl) PutResourceRecordTTLWithLimit((msg), (ptr), (count), (rr), (ttl), \
 286         (msg)->data + AbsoluteMaxDNSMessageData)
 287
 288 extern mDNSu8 *PutResourceRecordCappedTTL(DNSMessage *const msg, mDNSu8 *ptr, mDNSu16 *count, ResourceRecord *rr, mDNSu32 maxttl);
 289
 290 extern mDNSu8 *putEmptyResourceRecord(DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, mDNSu16 *count, const AuthRecord *rr);
 291
 292 extern mDNSu8 *putQuestion(DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, const domainname *const name, mDNSu16 rrtype, mDNSu16 rrclass);
 293
 294 extern mDNSu8 *putZone(DNSMessage *const msg, mDNSu8 *ptr, mDNSu8 *limit, const domainname *zone, mDNSOpaque16 zoneClass);
 295
 296 extern mDNSu8 *putPrereqNameNotInUse(domainname *name, DNSMessage *msg, mDNSu8 *ptr, mDNSu8 *end);
 297
 298 extern mDNSu8 *putDeletionRecord(DNSMessage *msg, mDNSu8 *ptr, ResourceRecord *rr);
 299
 300 extern  mDNSu8 *putDeleteRRSet(DNSMessage *msg, mDNSu8 *ptr, const domainname *name, mDNSu16 rrtype);
 301
 302 extern mDNSu8 *putDeleteAllRRSets(DNSMessage *msg, mDNSu8 *ptr, const domainname *name);
 303
 304 extern mDNSu8 *putUpdateLease(DNSMessage *msg, mDNSu8 *end, mDNSu32 lease);
 305
 306 #define PutResourceRecord(MSG, P, C, RR) PutResourceRecordTTL((MSG), (P), (C), (RR), (RR)->rroriginalttl)
 307
 308
 309 // ***************************************************************************
 310 #if COMPILER_LIKES_PRAGMA_MARK
 311 #pragma mark -
 312 #pragma mark - DNS Message Parsing Functions
 313 #endif
 314
 315 extern mDNSu32 DomainNameHashValue(const domainname *const name);
 316
 317 extern void SetNewRData(ResourceRecord *const rr, RData *NewRData, mDNSu16 rdlength);
 318
 319
 320 extern const mDNSu8 *skipDomainName(const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *const end);
 321
 322 extern const mDNSu8 *getDomainName(const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *const end,
 323         domainname *const name);
 324
 325 extern const mDNSu8 *skipResourceRecord(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end);
 326
 327 extern const mDNSu8 *GetLargeResourceRecord(mDNS *const m, const DNSMessage * const msg, const mDNSu8 *ptr,
 328     const mDNSu8 * end, const mDNSInterfaceID InterfaceID, mDNSu8 RecordType, LargeCacheRecord *largecr);
 329
 330 extern const mDNSu8 *skipQuestion(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end);
 331
 332 extern const mDNSu8 *getQuestion(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end, const mDNSInterfaceID InterfaceID,
 333         DNSQuestion *question);
 334
 335 extern const mDNSu8 *LocateAnswers(const DNSMessage *const msg, const mDNSu8 *const end);
 336
 337 extern const mDNSu8 *LocateAuthorities(const DNSMessage *const msg, const mDNSu8 *const end);
 338
 339 extern const mDNSu8 *LocateAdditionals(const DNSMessage *const msg, const mDNSu8 *const end);
 340
 341
 342 // ***************************************************************************
 343 #if COMPILER_LIKES_PRAGMA_MARK
 344 #pragma mark -
 345 #pragma mark -
 346 #pragma mark - Packet Sending Functions
 347 #endif
 348
 349 extern mStatus mDNSSendDNSMessage(const mDNS *const m, DNSMessage *const msg, mDNSu8 *end,
 350         mDNSInterfaceID InterfaceID, const mDNSAddr *dst, mDNSIPPort dstport, int sd, uDNS_AuthInfo *authInfo);
 351
 352
 353 // ***************************************************************************
 354 #if COMPILER_LIKES_PRAGMA_MARK
 355 #pragma mark -
 356 #pragma mark - RR List Management & Task Management
 357 #endif
 358
 359 extern void mDNS_Lock(mDNS *const m);
 360 extern void mDNS_Unlock(mDNS *const m);
 361
 362 #ifdef  __cplusplus
 363         }
 364 #endif
 365
 366 #endif // __DNSCOMMON_H_