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