source: rtems-libbsd/mDNSResponder/mDNSCore/DNSCommon.h @ f761b29

55-freebsd-126-freebsd-12
Last change on this file since f761b29 was f761b29, checked in by Sebastian Huber <sebastian.huber@…>, on 09/19/18 at 06:52:21

mDNSResponder: Update to v625.41.2

The sources can be obtained via:

https://opensource.apple.com/tarballs/mDNSResponder/mDNSResponder-625.41.2.tar.gz

Update #3522.

  • Property mode set to 100644
File size: 16.6 KB
Line 
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
18#ifndef __DNSCOMMON_H_
19#define __DNSCOMMON_H_
20
21#include "mDNSEmbeddedAPI.h"
22
23#ifdef  __cplusplus
24extern "C" {
25#endif
26
27//*************************************************************************************************************
28// Macros
29
30// Note: The C preprocessor stringify operator ('#') makes a string from its argument, without macro expansion
31// e.g. If "version" is #define'd to be "4", then STRINGIFY_AWE(version) will return the string "version", not "4"
32// To expand "version" to its value before making the string, use STRINGIFY(version) instead
33#define STRINGIFY_ARGUMENT_WITHOUT_EXPANSION(s) # s
34#define STRINGIFY(s) STRINGIFY_ARGUMENT_WITHOUT_EXPANSION(s)
35
36// ***************************************************************************
37#if COMPILER_LIKES_PRAGMA_MARK
38#pragma mark - DNS Protocol Constants
39#endif
40
41typedef enum
42{
43    kDNSFlag0_QR_Mask     = 0x80,       // Query or response?
44    kDNSFlag0_QR_Query    = 0x00,
45    kDNSFlag0_QR_Response = 0x80,
46
47    kDNSFlag0_OP_Mask     = 0x78,       // Operation type
48    kDNSFlag0_OP_StdQuery = 0x00,
49    kDNSFlag0_OP_Iquery   = 0x08,
50    kDNSFlag0_OP_Status   = 0x10,
51    kDNSFlag0_OP_Unused3  = 0x18,
52    kDNSFlag0_OP_Notify   = 0x20,
53    kDNSFlag0_OP_Update   = 0x28,
54
55    kDNSFlag0_QROP_Mask   = kDNSFlag0_QR_Mask | kDNSFlag0_OP_Mask,
56
57    kDNSFlag0_AA          = 0x04,       // Authoritative Answer?
58    kDNSFlag0_TC          = 0x02,       // Truncated?
59    kDNSFlag0_RD          = 0x01,       // Recursion Desired?
60    kDNSFlag1_RA          = 0x80,       // Recursion Available?
61
62    kDNSFlag1_Zero        = 0x40,       // Reserved; must be zero
63    kDNSFlag1_AD          = 0x20,       // Authentic Data [RFC 2535]
64    kDNSFlag1_CD          = 0x10,       // Checking Disabled [RFC 2535]
65
66    kDNSFlag1_RC_Mask     = 0x0F,       // Response code
67    kDNSFlag1_RC_NoErr    = 0x00,
68    kDNSFlag1_RC_FormErr  = 0x01,
69    kDNSFlag1_RC_ServFail = 0x02,
70    kDNSFlag1_RC_NXDomain = 0x03,
71    kDNSFlag1_RC_NotImpl  = 0x04,
72    kDNSFlag1_RC_Refused  = 0x05,
73    kDNSFlag1_RC_YXDomain = 0x06,
74    kDNSFlag1_RC_YXRRSet  = 0x07,
75    kDNSFlag1_RC_NXRRSet  = 0x08,
76    kDNSFlag1_RC_NotAuth  = 0x09,
77    kDNSFlag1_RC_NotZone  = 0x0A
78} DNS_Flags;
79
80typedef enum
81{
82    TSIG_ErrBadSig  = 16,
83    TSIG_ErrBadKey  = 17,
84    TSIG_ErrBadTime = 18
85} TSIG_ErrorCode;
86
87// ***************************************************************************
88#if COMPILER_LIKES_PRAGMA_MARK
89#pragma mark -
90#pragma mark - General Utility Functions
91#endif
92
93extern NetworkInterfaceInfo *GetFirstActiveInterface(NetworkInterfaceInfo *intf);
94extern mDNSInterfaceID GetNextActiveInterfaceID(const NetworkInterfaceInfo *intf);
95
96extern mDNSu32 mDNSRandom(mDNSu32 max);     // Returns pseudo-random result from zero to max inclusive
97
98// ***************************************************************************
99#if COMPILER_LIKES_PRAGMA_MARK
100#pragma mark -
101#pragma mark - Domain Name Utility Functions
102#endif
103
104#define mDNSSubTypeLabel   "\x04_sub"
105
106#define mDNSIsDigit(X)     ((X) >= '0' && (X) <= '9')
107#define mDNSIsUpperCase(X) ((X) >= 'A' && (X) <= 'Z')
108#define mDNSIsLowerCase(X) ((X) >= 'a' && (X) <= 'z')
109#define mDNSIsLetter(X)    (mDNSIsUpperCase(X) || mDNSIsLowerCase(X))
110
111#define mDNSValidHostChar(X, notfirst, notlast) (mDNSIsLetter(X) || mDNSIsDigit(X) || ((notfirst) && (notlast) && (X) == '-') )
112
113extern mDNSu16 CompressedDomainNameLength(const domainname *const name, const domainname *parent);
114extern int CountLabels(const domainname *d);
115extern const domainname *SkipLeadingLabels(const domainname *d, int skip);
116
117extern mDNSu32 TruncateUTF8ToLength(mDNSu8 *string, mDNSu32 length, mDNSu32 max);
118extern mDNSBool LabelContainsSuffix(const domainlabel *const name, const mDNSBool RichText);
119extern mDNSu32 RemoveLabelSuffix(domainlabel *name, mDNSBool RichText);
120extern void AppendLabelSuffix(domainlabel *const name, mDNSu32 val, const mDNSBool RichText);
121#define ValidateDomainName(N) (DomainNameLength(N) <= MAX_DOMAIN_NAME)
122
123// ***************************************************************************
124#if COMPILER_LIKES_PRAGMA_MARK
125#pragma mark -
126#pragma mark - Resource Record Utility Functions
127#endif
128
129// IdenticalResourceRecord returns true if two resources records have
130// the same name, type, class, and identical rdata (InterfaceID and TTL may differ)
131
132// IdenticalSameNameRecord is the same, except it skips the expensive SameDomainName() check,
133// which is at its most expensive and least useful in cases where we know in advance that the names match
134
135// Note: The dominant use of IdenticalResourceRecord is from ProcessQuery(), handling known-answer lists. In this case
136// it's common to have a whole bunch or records with exactly the same name (e.g. "_http._tcp.local") but different RDATA.
137// The SameDomainName() check is expensive when the names match, and in this case *all* the names match, so we
138// used to waste a lot of CPU time verifying that the names match, only then to find that the RDATA is different.
139// We observed mDNSResponder spending 30% of its total CPU time on this single task alone.
140// By swapping the checks so that we check the RDATA first, we can quickly detect when it's different
141// (99% of the time) and then bail out before we waste time on the expensive SameDomainName() check.
142
143#define IdenticalResourceRecord(r1,r2) ( \
144        (r1)->rrtype    == (r2)->rrtype      && \
145        (r1)->rrclass   == (r2)->rrclass     && \
146        (r1)->namehash  == (r2)->namehash    && \
147        (r1)->rdlength  == (r2)->rdlength    && \
148        (r1)->rdatahash == (r2)->rdatahash   && \
149        SameRDataBody((r1), &(r2)->rdata->u, SameDomainName) && \
150        SameDomainName((r1)->name, (r2)->name))
151
152#define IdenticalSameNameRecord(r1,r2) ( \
153        (r1)->rrtype    == (r2)->rrtype      && \
154        (r1)->rrclass   == (r2)->rrclass     && \
155        (r1)->rdlength  == (r2)->rdlength    && \
156        (r1)->rdatahash == (r2)->rdatahash   && \
157        SameRDataBody((r1), &(r2)->rdata->u, SameDomainName))
158
159// A given RRType answers a QuestionType if RRType is CNAME, or types match, or QuestionType is ANY,
160// or the RRType is NSEC and positively asserts the nonexistence of the type being requested
161#define RRTypeAnswersQuestionType(R,Q) ((R)->rrtype == kDNSType_CNAME || (R)->rrtype == (Q) || (Q) == kDNSQType_ANY || RRAssertsNonexistence((R),(Q)))
162// Unicast NSEC records have the NSEC bit set whereas the multicast NSEC ones don't
163#define UNICAST_NSEC(rr) ((rr)->rrtype == kDNSType_NSEC && RRAssertsExistence((rr), kDNSType_NSEC))
164
165extern mDNSu32 RDataHashValue(const ResourceRecord *const rr);
166extern mDNSBool SameRDataBody(const ResourceRecord *const r1, const RDataBody *const r2, DomainNameComparisonFn *samename);
167extern mDNSBool SameNameRecordAnswersQuestion(const ResourceRecord *const rr, const DNSQuestion *const q);
168extern mDNSBool ResourceRecordAnswersQuestion(const ResourceRecord *const rr, const DNSQuestion *const q);
169extern mDNSBool AnyTypeRecordAnswersQuestion (const ResourceRecord *const rr, const DNSQuestion *const q);
170extern mDNSBool ResourceRecordAnswersUnicastResponse(const ResourceRecord *const rr, const DNSQuestion *const q);
171extern mDNSBool LocalOnlyRecordAnswersQuestion(AuthRecord *const rr, const DNSQuestion *const q);
172extern mDNSu16 GetRDLength(const ResourceRecord *const rr, mDNSBool estimate);
173extern mDNSBool ValidateRData(const mDNSu16 rrtype, const mDNSu16 rdlength, const RData *const rd);
174extern mStatus DNSNameToLowerCase(domainname *d, domainname *result);
175
176#define GetRRDomainNameTarget(RR) (                                                                          \
177        ((RR)->rrtype == kDNSType_NS || (RR)->rrtype == kDNSType_CNAME || (RR)->rrtype == kDNSType_PTR || (RR)->rrtype == kDNSType_DNAME) ? &(RR)->rdata->u.name        : \
178        ((RR)->rrtype == kDNSType_MX || (RR)->rrtype == kDNSType_AFSDB || (RR)->rrtype == kDNSType_RT  || (RR)->rrtype == kDNSType_KX   ) ? &(RR)->rdata->u.mx.exchange : \
179        ((RR)->rrtype == kDNSType_SRV                                  ) ? &(RR)->rdata->u.srv.target : mDNSNULL )
180
181#define LocalRecordReady(X) ((X)->resrec.RecordType != kDNSRecordTypeUnique)
182
183// ***************************************************************************
184#if COMPILER_LIKES_PRAGMA_MARK
185#pragma mark -
186#pragma mark - DNS Message Creation Functions
187#endif
188
189extern void InitializeDNSMessage(DNSMessageHeader *h, mDNSOpaque16 id, mDNSOpaque16 flags);
190extern const mDNSu8 *FindCompressionPointer(const mDNSu8 *const base, const mDNSu8 *const end, const mDNSu8 *const domname);
191extern mDNSu8 *putDomainNameAsLabels(const DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, const domainname *const name);
192extern mDNSu8 *putRData(const DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, const ResourceRecord *const rr);
193
194// If we have a single large record to put in the packet, then we allow the packet to be up to 9K bytes,
195// but in the normal case we try to keep the packets below 1500 to avoid IP fragmentation on standard Ethernet
196
197#define AllowedRRSpace(msg) (((msg)->h.numAnswers || (msg)->h.numAuthorities || (msg)->h.numAdditionals) ? NormalMaxDNSMessageData : AbsoluteMaxDNSMessageData)
198
199extern mDNSu8 *PutResourceRecordTTLWithLimit(DNSMessage *const msg, mDNSu8 *ptr, mDNSu16 *count, ResourceRecord *rr, mDNSu32 ttl, const mDNSu8 *limit);
200
201#define PutResourceRecordTTL(msg, ptr, count, rr, ttl) \
202    PutResourceRecordTTLWithLimit((msg), (ptr), (count), (rr), (ttl), (msg)->data + AllowedRRSpace(msg))
203
204#define PutResourceRecordTTLJumbo(msg, ptr, count, rr, ttl) \
205    PutResourceRecordTTLWithLimit((msg), (ptr), (count), (rr), (ttl), (msg)->data + AbsoluteMaxDNSMessageData)
206
207#define PutResourceRecord(MSG, P, C, RR) PutResourceRecordTTL((MSG), (P), (C), (RR), (RR)->rroriginalttl)
208
209// The PutRR_OS variants assume a local variable 'm', put build the packet at m->omsg,
210// and assume local variables 'OwnerRecordSpace' & 'TraceRecordSpace' indicating how many bytes (if any) to reserve to add an OWNER/TRACER option at the end
211#define PutRR_OS_TTL(ptr, count, rr, ttl) \
212    PutResourceRecordTTLWithLimit(&m->omsg, (ptr), (count), (rr), (ttl), m->omsg.data + AllowedRRSpace(&m->omsg) - OwnerRecordSpace - TraceRecordSpace)
213
214#define PutRR_OS(P, C, RR) PutRR_OS_TTL((P), (C), (RR), (RR)->rroriginalttl)
215
216extern mDNSu8 *putQuestion(DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, const domainname *const name, mDNSu16 rrtype, mDNSu16 rrclass);
217extern mDNSu8 *putZone(DNSMessage *const msg, mDNSu8 *ptr, mDNSu8 *limit, const domainname *zone, mDNSOpaque16 zoneClass);
218extern mDNSu8 *putPrereqNameNotInUse(const domainname *const name, DNSMessage *const msg, mDNSu8 *const ptr, mDNSu8 *const end);
219extern mDNSu8 *putDeletionRecord(DNSMessage *msg, mDNSu8 *ptr, ResourceRecord *rr);
220extern mDNSu8 *putDeletionRecordWithLimit(DNSMessage *msg, mDNSu8 *ptr, ResourceRecord *rr, mDNSu8 *limit);
221extern mDNSu8 *putDeleteRRSetWithLimit(DNSMessage *msg, mDNSu8 *ptr, const domainname *name, mDNSu16 rrtype, mDNSu8 *limit);
222extern mDNSu8 *putDeleteAllRRSets(DNSMessage *msg, mDNSu8 *ptr, const domainname *name);
223extern mDNSu8 *putUpdateLease(DNSMessage *msg, mDNSu8 *ptr, mDNSu32 lease);
224extern mDNSu8 *putUpdateLeaseWithLimit(DNSMessage *msg, mDNSu8 *ptr, mDNSu32 lease, mDNSu8 *limit);
225
226extern mDNSu8 *putHINFO(const mDNS *const m, DNSMessage *const msg, mDNSu8 *ptr, DomainAuthInfo *authInfo, mDNSu8 *limit);
227extern mDNSu8 *putDNSSECOption(DNSMessage *msg, mDNSu8 *end, mDNSu8 *limit);
228extern int baseEncode(char *buffer, int blen, const mDNSu8 *data, int len, int encAlg);
229extern void NSEC3Parse(const ResourceRecord *const rr, mDNSu8 **salt, int *hashLength, mDNSu8 **nxtName, int *bitmaplen, mDNSu8 **bitmap);
230
231extern const mDNSu8 *NSEC3HashName(const domainname *name, rdataNSEC3 *nsec3, const mDNSu8 *AnonData, int AnonDataLen,
232    const mDNSu8 hash[NSEC3_MAX_HASH_LEN], int *dlen);
233
234// ***************************************************************************
235#if COMPILER_LIKES_PRAGMA_MARK
236#pragma mark -
237#pragma mark - DNS Message Parsing Functions
238#endif
239
240#define AuthHashSlot(X) (DomainNameHashValue(X) % AUTH_HASH_SLOTS)
241#define HashSlot(X) (DomainNameHashValue(X) % CACHE_HASH_SLOTS)
242extern mDNSu32 DomainNameHashValue(const domainname *const name);
243extern void SetNewRData(ResourceRecord *const rr, RData *NewRData, mDNSu16 rdlength);
244extern const mDNSu8 *skipDomainName(const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *const end);
245extern const mDNSu8 *getDomainName(const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *const end,
246                                   domainname *const name);
247extern const mDNSu8 *skipResourceRecord(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end);
248extern const mDNSu8 *GetLargeResourceRecord(mDNS *const m, const DNSMessage * const msg, const mDNSu8 *ptr,
249                                            const mDNSu8 * end, const mDNSInterfaceID InterfaceID, mDNSu8 RecordType, LargeCacheRecord *const largecr);
250extern mDNSBool SetRData(const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *end,
251    LargeCacheRecord *const largecr, mDNSu16 rdlength);
252extern const mDNSu8 *skipQuestion(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end);
253extern const mDNSu8 *getQuestion(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end, const mDNSInterfaceID InterfaceID,
254                                 DNSQuestion *question);
255extern const mDNSu8 *LocateAnswers(const DNSMessage *const msg, const mDNSu8 *const end);
256extern const mDNSu8 *LocateAuthorities(const DNSMessage *const msg, const mDNSu8 *const end);
257extern const mDNSu8 *LocateAdditionals(const DNSMessage *const msg, const mDNSu8 *const end);
258extern const mDNSu8 *LocateOptRR(const DNSMessage *const msg, const mDNSu8 *const end, int minsize);
259extern const rdataOPT *GetLLQOptData(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end);
260extern mDNSu32 GetPktLease(mDNS *m, DNSMessage *msg, const mDNSu8 *end);
261extern void DumpPacket(mDNS *const m, mStatus status, mDNSBool sent, char *transport,
262                       const mDNSAddr *srcaddr, mDNSIPPort srcport,
263                       const mDNSAddr *dstaddr, mDNSIPPort dstport, const DNSMessage *const msg, const mDNSu8 *const end);
264extern mDNSBool RRAssertsNonexistence(const ResourceRecord *const rr, mDNSu16 type);
265extern mDNSBool RRAssertsExistence(const ResourceRecord *const rr, mDNSu16 type);
266extern mDNSBool BitmapTypeCheck(mDNSu8 *bmap, int bitmaplen, mDNSu16 type);
267
268extern mDNSu16 swap16(mDNSu16 x);
269extern mDNSu32 swap32(mDNSu32 x);
270
271// ***************************************************************************
272#if COMPILER_LIKES_PRAGMA_MARK
273#pragma mark -
274#pragma mark - Packet Sending Functions
275#endif
276
277extern mStatus mDNSSendDNSMessage(mDNS *const m, DNSMessage *const msg, mDNSu8 *end,
278                                  mDNSInterfaceID InterfaceID, UDPSocket *src, const mDNSAddr *dst,
279                                  mDNSIPPort dstport, TCPSocket *sock, DomainAuthInfo *authInfo,
280                                  mDNSBool useBackgroundTrafficClass);
281
282// ***************************************************************************
283#if COMPILER_LIKES_PRAGMA_MARK
284#pragma mark -
285#pragma mark - RR List Management & Task Management
286#endif
287
288extern void ShowTaskSchedulingError(mDNS *const m);
289extern void mDNS_Lock_(mDNS *const m, const char * const functionname);
290extern void mDNS_Unlock_(mDNS *const m, const char * const functionname);
291
292#if defined(_WIN32)
293 #define __func__ __FUNCTION__
294#endif
295
296#define mDNS_Lock(X) mDNS_Lock_((X), __func__)
297
298#define mDNS_Unlock(X) mDNS_Unlock_((X), __func__)
299
300#define mDNS_CheckLock(X) \
301    if ((X)->mDNS_busy != (X)->mDNS_reentrancy+1) LogMsg("%s: Lock not held! mDNS_busy (%ld) mDNS_reentrancy (%ld)", __func__, (X)->mDNS_busy, (X)->mDNS_reentrancy)
302
303#define mDNS_DropLockBeforeCallback() do { m->mDNS_reentrancy++; \
304    if (m->mDNS_busy != m->mDNS_reentrancy) LogMsg("%s: Locking Failure! mDNS_busy (%ld) != mDNS_reentrancy (%ld)", __func__, m->mDNS_busy, m->mDNS_reentrancy); \
305    } while (0)
306
307#define mDNS_ReclaimLockAfterCallback() do { \
308    if (m->mDNS_busy != m->mDNS_reentrancy) LogMsg("%s: Unlocking Failure! mDNS_busy (%ld) != mDNS_reentrancy (%ld)", __func__, m->mDNS_busy, m->mDNS_reentrancy); \
309    m->mDNS_reentrancy--; } while (0)
310
311#ifdef  __cplusplus
312}
313#endif
314
315#endif // __DNSCOMMON_H_
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