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 $ 20Revision 1.34.2.1 2006/08/29 06:24:22 cheshire 21Re-licensed mDNSResponder daemon source code under Apache License, Version 2.0 22 23Revision 1.34 2006/03/18 21:47:56 cheshire 24<rdar://problem/4073825> Improve logic for delaying packets after repeated interface transitions 25 26Revision 1.33 2006/03/10 21:51:41 cheshire 27<rdar://problem/4111464> After record update, old record sometimes remains in cache 28Split out SameRDataBody() into a separate routine so it can be called from other code 29 30Revision 1.32 2005/03/21 00:33:51 shersche 31<rdar://problem/4021486> Fix build warnings on Win32 platform 32 33Revision 1.31 2005/02/18 00:43:11 cheshire 34<rdar://problem/4010245> mDNSResponder should auto-truncate service names that are too long 35 36Revision 1.30 2005/01/19 03:12:44 cheshire 37Move LocalRecordReady() macro from mDNS.c to DNSCommon.h 38 39Revision 1.29 2004/12/15 02:11:22 ksekar 40<rdar://problem/3917317> Don't check for Dynamic DNS hostname uniqueness 41 42Revision 1.28 2004/12/06 21:15:22 ksekar 43<rdar://problem/3884386> mDNSResponder crashed in CheckServiceRegistrations 44 45Revision 1.27 2004/12/03 07:20:50 ksekar 46<rdar://problem/3674208> Wide-Area: Registration of large TXT record fails 47 48Revision 1.26 2004/12/03 05:18:33 ksekar 49<rdar://problem/3810596> mDNSResponder needs to return more specific TSIG errors 50 51Revision 1.25 2004/10/26 03:52:02 cheshire 52Update checkin comments 53 54Revision 1.24 2004/10/23 01:16:00 cheshire 55<rdar://problem/3851677> uDNS operations not always reliable on multi-homed hosts 56 57Revision 1.23 2004/10/03 23:18:58 cheshire 58Move address comparison macros from DNSCommon.h to mDNSEmbeddedAPI.h 59 60Revision 1.22 2004/09/30 00:24:56 ksekar 61<rdar://problem/3695802> Dynamically update default registration domains on config change 62 63Revision 1.21 2004/09/17 01:08:48 cheshire 64Renamed 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 69Revision 1.20 2004/09/17 00:49:51 cheshire 70Get rid of now-unused GetResourceRecord -- the correct (safe) routine to use 71is GetLargeResourceRecord 72 73Revision 1.19 2004/09/16 21:59:15 cheshire 74For consistency with zerov6Addr, rename zeroIPAddr to zerov4Addr 75 76Revision 1.18 2004/09/16 02:29:39 cheshire 77Moved mDNS_Lock/mDNS_Unlock to DNSCommon.c; Added necessary locking around 78uDNS_ReceiveMsg, uDNS_StartQuery, uDNS_UpdateRecord, uDNS_RegisterService 79 80Revision 1.17 2004/09/14 23:27:46 cheshire 81Fix compile errors 82 83Revision 1.16 2004/08/13 23:46:58 cheshire 84"asyncronous" -> "asynchronous" 85 86Revision 1.15 2004/08/10 23:19:14 ksekar 87<rdar://problem/3722542>: DNS Extension daemon for Wide Area Service Discovery 88Moved routines/constants to allow extern access for garbage collection daemon 89 90Revision 1.14 2004/05/28 23:42:36 ksekar 91<rdar://problem/3258021>: Feature: DNS server->client notification on record changes (#7805) 92 93Revision 1.13 2004/05/18 23:51:25 cheshire 94Tidy up all checkin comments to use consistent "<rdar://problem/xxxxxxx>" format for bug numbers 95 96Revision 1.12 2004/04/22 04:03:59 cheshire 97Headers should use "extern" declarations, not "mDNSexport" 98 99Revision 1.11 2004/04/14 23:09:28 ksekar 100Support for TSIG signed dynamic updates. 101 102Revision 1.10 2004/03/13 01:57:33 ksekar 103<rdar://problem/3192546>: DynDNS: Dynamic update of service records 104 105Revision 1.9 2004/02/21 08:56:58 bradley 106Wrap prototypes with extern "C" for C++ builds. 107 108Revision 1.8 2004/02/06 23:04:18 ksekar 109Basic Dynamic Update support via mDNS_Register (dissabled via 110UNICAST_REGISTRATION #define) 111 112Revision 1.7 2004/02/03 19:47:36 ksekar 113Added an asynchronous state machine mechanism to uDNS.c, including 114calls to find the parent zone for a domain name. Changes include code 115in repository previously dissabled via "#if 0 incomplete". Codepath 116is currently unused, and will be called to create update records, etc. 117 118Revision 1.6 2004/01/27 20:15:22 cheshire 119<rdar://problem/3541288>: Time to prune obsolete code for listening on port 53 120 121Revision 1.5 2004/01/24 03:40:56 cheshire 122Move mDNSAddrIsDNSMulticast() from DNSCommon.h to mDNSEmbeddedAPI.h so embedded clients can use it 123 124Revision 1.4 2004/01/24 03:38:27 cheshire 125Fix minor syntactic error: Headers should use "extern" declarations, not "mDNSexport" 126 127Revision 1.3 2004/01/23 23:23:14 ksekar 128Added TCP support for truncated unicast messages. 129 130Revision 1.2 2004/01/21 21:12:23 cheshire 131Add missing newline at end of file to make Unix tools happier 132 133Revision 1.1 2003/12/13 03:05:27 ksekar 134<rdar://problem/3192548>: DynDNS: Unicast query of service records 135 136 137 */ 138 139#pragma ident "%Z%%M% %I% %E% SMI" 140 141#ifndef __DNSCOMMON_H_ 142#define __DNSCOMMON_H_ 143 144#include "mDNSEmbeddedAPI.h" 145 146#ifdef __cplusplus 147 extern "C" { 148#endif 149 150 151// *************************************************************************** 152#if COMPILER_LIKES_PRAGMA_MARK 153#pragma mark - DNS Protocol Constants 154#endif 155 156typedef enum 157 { 158 kDNSFlag0_QR_Mask = 0x80, // Query or response? 159 kDNSFlag0_QR_Query = 0x00, 160 kDNSFlag0_QR_Response = 0x80, 161 162 kDNSFlag0_OP_Mask = 0x78, // Operation type 163 kDNSFlag0_OP_StdQuery = 0x00, 164 kDNSFlag0_OP_Iquery = 0x08, 165 kDNSFlag0_OP_Status = 0x10, 166 kDNSFlag0_OP_Unused3 = 0x18, 167 kDNSFlag0_OP_Notify = 0x20, 168 kDNSFlag0_OP_Update = 0x28, 169 170 kDNSFlag0_QROP_Mask = kDNSFlag0_QR_Mask | kDNSFlag0_OP_Mask, 171 172 kDNSFlag0_AA = 0x04, // Authoritative Answer? 173 kDNSFlag0_TC = 0x02, // Truncated? 174 kDNSFlag0_RD = 0x01, // Recursion Desired? 175 kDNSFlag1_RA = 0x80, // Recursion Available? 176 177 kDNSFlag1_Zero = 0x40, // Reserved; must be zero 178 kDNSFlag1_AD = 0x20, // Authentic Data [RFC 2535] 179 kDNSFlag1_CD = 0x10, // Checking Disabled [RFC 2535] 180 181 kDNSFlag1_RC = 0x0F, // Response code 182 kDNSFlag1_RC_NoErr = 0x00, 183 kDNSFlag1_RC_FmtErr = 0x01, 184 kDNSFlag1_RC_SrvErr = 0x02, 185 kDNSFlag1_RC_NXDomain = 0x03, 186 kDNSFlag1_RC_NotImpl = 0x04, 187 kDNSFlag1_RC_Refused = 0x05, 188 kDNSFlag1_RC_YXDomain = 0x06, 189 kDNSFlag1_RC_YXRRSet = 0x07, 190 kDNSFlag1_RC_NXRRSet = 0x08, 191 kDNSFlag1_RC_NotAuth = 0x09, 192 kDNSFlag1_RC_NotZone = 0x0A 193 } DNS_Flags; 194 195typedef enum 196 { 197 TSIG_ErrBadSig = 16, 198 TSIG_ErrBadKey = 17, 199 TSIG_ErrBadTime = 18 200 } TSIG_ErrorCode; 201 202 203// *************************************************************************** 204#if COMPILER_LIKES_PRAGMA_MARK 205#pragma mark - 206#pragma mark - General Utility Functions 207#endif 208 209extern const NetworkInterfaceInfo *GetFirstActiveInterface(const NetworkInterfaceInfo *intf); 210extern mDNSInterfaceID GetNextActiveInterfaceID(const NetworkInterfaceInfo *intf); 211 212extern mDNSu32 mDNSRandom(mDNSu32 max); 213extern mDNSu32 mDNSRandomFromFixedSeed(mDNSu32 seed, mDNSu32 max); 214 215 216// *************************************************************************** 217#if COMPILER_LIKES_PRAGMA_MARK 218#pragma mark - 219#pragma mark - Domain Name Utility Functions 220#endif 221 222#define mdnsIsDigit(X) ((X) >= '0' && (X) <= '9') 223#define mDNSIsUpperCase(X) ((X) >= 'A' && (X) <= 'Z') 224#define mDNSIsLowerCase(X) ((X) >= 'a' && (X) <= 'z') 225#define mdnsIsLetter(X) (mDNSIsUpperCase(X) || mDNSIsLowerCase(X)) 226 227#define mdnsValidHostChar(X, notfirst, notlast) (mdnsIsLetter(X) || mdnsIsDigit(X) || ((notfirst) && (notlast) && (X) == '-') ) 228 229extern mDNSu16 CompressedDomainNameLength(const domainname *const name, const domainname *parent); 230 231extern mDNSu32 TruncateUTF8ToLength(mDNSu8 *string, mDNSu32 length, mDNSu32 max); 232extern mDNSBool LabelContainsSuffix(const domainlabel *const name, const mDNSBool RichText); 233extern mDNSu32 RemoveLabelSuffix(domainlabel *name, mDNSBool RichText); 234extern void AppendLabelSuffix(domainlabel *name, mDNSu32 val, mDNSBool RichText); 235extern void mDNS_HostNameCallback(mDNS *const m, AuthRecord *const rr, mStatus result); 236#define ValidateDomainName(N) (DomainNameLength(N) <= MAX_DOMAIN_NAME) 237 238 239// *************************************************************************** 240#if COMPILER_LIKES_PRAGMA_MARK 241#pragma mark - 242#pragma mark - Resource Record Utility Functions 243#endif 244 245extern mDNSu32 RDataHashValue(mDNSu16 const rdlength, const RDataBody *const rdb); 246 247extern mDNSBool SameRDataBody(const ResourceRecord *const r1, const RDataBody *const r2); 248extern mDNSBool SameRData(const ResourceRecord *const r1, const ResourceRecord *const r2); 249 250extern mDNSBool ResourceRecordAnswersQuestion(const ResourceRecord *const rr, const DNSQuestion *const q); 251 252extern mDNSBool SameResourceRecord(ResourceRecord *r1, ResourceRecord *r2); 253 254extern mDNSu16 GetRDLength(const ResourceRecord *const rr, mDNSBool estimate); 255 256#define GetRRDomainNameTarget(RR) ( \ 257 ((RR)->rrtype == kDNSType_CNAME || (RR)->rrtype == kDNSType_PTR || (RR)->rrtype == kDNSType_NS) \ 258 ? &(RR)->rdata->u.name : \ 259 ((RR)->rrtype == kDNSType_SRV ) ? &(RR)->rdata->u.srv.target : mDNSNULL ) 260 261extern mDNSBool ValidateRData(const mDNSu16 rrtype, const mDNSu16 rdlength, const RData *const rd); 262#define LocalRecordReady(X) ((X)->resrec.RecordType != kDNSRecordTypeUnique && (X)->resrec.RecordType != kDNSRecordTypeDeregistering) 263 264 265// *************************************************************************** 266#if COMPILER_LIKES_PRAGMA_MARK 267#pragma mark - 268#pragma mark - 269#pragma mark - DNS Message Creation Functions 270#endif 271 272extern void InitializeDNSMessage(DNSMessageHeader *h, mDNSOpaque16 id, mDNSOpaque16 flags); 273extern const mDNSu8 *FindCompressionPointer(const mDNSu8 *const base, const mDNSu8 *const end, const mDNSu8 *const domname); 274 275extern mDNSu8 *putDomainNameAsLabels(const DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, const domainname *const name); 276 277extern mDNSu8 *putRData(const DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, ResourceRecord *rr); 278 279// If we have a single large record to put in the packet, then we allow the packet to be up to 9K bytes, 280// but in the normal case we try to keep the packets below 1500 to avoid IP fragmentation on standard Ethernet 281 282extern mDNSu8 *PutResourceRecordTTLWithLimit(DNSMessage *const msg, mDNSu8 *ptr, mDNSu16 *count, ResourceRecord *rr, mDNSu32 ttl, const mDNSu8 *limit); 283 284#define PutResourceRecordTTL(msg, ptr, count, rr, ttl) PutResourceRecordTTLWithLimit((msg), (ptr), (count), (rr), (ttl), \ 285 ((msg)->h.numAnswers || (msg)->h.numAuthorities || (msg)->h.numAdditionals) ? (msg)->data + NormalMaxDNSMessageData : (msg)->data + AbsoluteMaxDNSMessageData) 286 287#define PutResourceRecordTTLJumbo(msg, ptr, count, rr, ttl) PutResourceRecordTTLWithLimit((msg), (ptr), (count), (rr), (ttl), \ 288 (msg)->data + AbsoluteMaxDNSMessageData) 289 290extern mDNSu8 *PutResourceRecordCappedTTL(DNSMessage *const msg, mDNSu8 *ptr, mDNSu16 *count, ResourceRecord *rr, mDNSu32 maxttl); 291 292extern mDNSu8 *putEmptyResourceRecord(DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, mDNSu16 *count, const AuthRecord *rr); 293 294extern mDNSu8 *putQuestion(DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, const domainname *const name, mDNSu16 rrtype, mDNSu16 rrclass); 295 296extern mDNSu8 *putZone(DNSMessage *const msg, mDNSu8 *ptr, mDNSu8 *limit, const domainname *zone, mDNSOpaque16 zoneClass); 297 298extern mDNSu8 *putPrereqNameNotInUse(domainname *name, DNSMessage *msg, mDNSu8 *ptr, mDNSu8 *end); 299 300extern mDNSu8 *putDeletionRecord(DNSMessage *msg, mDNSu8 *ptr, ResourceRecord *rr); 301 302extern mDNSu8 *putDeleteRRSet(DNSMessage *msg, mDNSu8 *ptr, const domainname *name, mDNSu16 rrtype); 303 304extern mDNSu8 *putDeleteAllRRSets(DNSMessage *msg, mDNSu8 *ptr, const domainname *name); 305 306extern mDNSu8 *putUpdateLease(DNSMessage *msg, mDNSu8 *end, mDNSu32 lease); 307 308#define PutResourceRecord(MSG, P, C, RR) PutResourceRecordTTL((MSG), (P), (C), (RR), (RR)->rroriginalttl) 309 310 311// *************************************************************************** 312#if COMPILER_LIKES_PRAGMA_MARK 313#pragma mark - 314#pragma mark - DNS Message Parsing Functions 315#endif 316 317extern mDNSu32 DomainNameHashValue(const domainname *const name); 318 319extern void SetNewRData(ResourceRecord *const rr, RData *NewRData, mDNSu16 rdlength); 320 321 322extern const mDNSu8 *skipDomainName(const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *const end); 323 324extern const mDNSu8 *getDomainName(const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *const end, 325 domainname *const name); 326 327extern const mDNSu8 *skipResourceRecord(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end); 328 329extern const mDNSu8 *GetLargeResourceRecord(mDNS *const m, const DNSMessage * const msg, const mDNSu8 *ptr, 330 const mDNSu8 * end, const mDNSInterfaceID InterfaceID, mDNSu8 RecordType, LargeCacheRecord *largecr); 331 332extern const mDNSu8 *skipQuestion(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end); 333 334extern const mDNSu8 *getQuestion(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end, const mDNSInterfaceID InterfaceID, 335 DNSQuestion *question); 336 337extern const mDNSu8 *LocateAnswers(const DNSMessage *const msg, const mDNSu8 *const end); 338 339extern const mDNSu8 *LocateAuthorities(const DNSMessage *const msg, const mDNSu8 *const end); 340 341extern const mDNSu8 *LocateAdditionals(const DNSMessage *const msg, const mDNSu8 *const end); 342 343 344// *************************************************************************** 345#if COMPILER_LIKES_PRAGMA_MARK 346#pragma mark - 347#pragma mark - 348#pragma mark - Packet Sending Functions 349#endif 350 351extern mStatus mDNSSendDNSMessage(const mDNS *const m, DNSMessage *const msg, mDNSu8 *end, 352 mDNSInterfaceID InterfaceID, const mDNSAddr *dst, mDNSIPPort dstport, int sd, uDNS_AuthInfo *authInfo); 353 354 355// *************************************************************************** 356#if COMPILER_LIKES_PRAGMA_MARK 357#pragma mark - 358#pragma mark - RR List Management & Task Management 359#endif 360 361extern void mDNS_Lock(mDNS *const m); 362extern void mDNS_Unlock(mDNS *const m); 363 364#ifdef __cplusplus 365 } 366#endif 367 368#endif // __DNSCOMMON_H_ 369