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Diffstat (limited to 'mDNSResponder/mDNSCore/DNSCommon.h')
| -rw-r--r-- | mDNSResponder/mDNSCore/DNSCommon.h | 315 |
1 files changed, 315 insertions, 0 deletions
diff --git a/mDNSResponder/mDNSCore/DNSCommon.h b/mDNSResponder/mDNSCore/DNSCommon.h new file mode 100644 index 00000000..b92f5a9a --- /dev/null +++ b/mDNSResponder/mDNSCore/DNSCommon.h @@ -0,0 +1,315 @@ +/* -*- Mode: C; tab-width: 4 -*- + * + * Copyright (c) 2002-2003 Apple Computer, Inc. All rights reserved. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#ifndef __DNSCOMMON_H_ +#define __DNSCOMMON_H_ + +#include "mDNSEmbeddedAPI.h" + +#ifdef __cplusplus +extern "C" { +#endif + +//************************************************************************************************************* +// Macros + +// Note: The C preprocessor stringify operator ('#') makes a string from its argument, without macro expansion +// e.g. If "version" is #define'd to be "4", then STRINGIFY_AWE(version) will return the string "version", not "4" +// To expand "version" to its value before making the string, use STRINGIFY(version) instead +#define STRINGIFY_ARGUMENT_WITHOUT_EXPANSION(s) # s +#define STRINGIFY(s) STRINGIFY_ARGUMENT_WITHOUT_EXPANSION(s) + +// *************************************************************************** +#if COMPILER_LIKES_PRAGMA_MARK +#pragma mark - DNS Protocol Constants +#endif + +typedef enum +{ + kDNSFlag0_QR_Mask = 0x80, // Query or response? + kDNSFlag0_QR_Query = 0x00, + kDNSFlag0_QR_Response = 0x80, + + kDNSFlag0_OP_Mask = 0x78, // Operation type + kDNSFlag0_OP_StdQuery = 0x00, + kDNSFlag0_OP_Iquery = 0x08, + kDNSFlag0_OP_Status = 0x10, + kDNSFlag0_OP_Unused3 = 0x18, + kDNSFlag0_OP_Notify = 0x20, + kDNSFlag0_OP_Update = 0x28, + + kDNSFlag0_QROP_Mask = kDNSFlag0_QR_Mask | kDNSFlag0_OP_Mask, + + kDNSFlag0_AA = 0x04, // Authoritative Answer? + kDNSFlag0_TC = 0x02, // Truncated? + kDNSFlag0_RD = 0x01, // Recursion Desired? + kDNSFlag1_RA = 0x80, // Recursion Available? + + kDNSFlag1_Zero = 0x40, // Reserved; must be zero + kDNSFlag1_AD = 0x20, // Authentic Data [RFC 2535] + kDNSFlag1_CD = 0x10, // Checking Disabled [RFC 2535] + + kDNSFlag1_RC_Mask = 0x0F, // Response code + kDNSFlag1_RC_NoErr = 0x00, + kDNSFlag1_RC_FormErr = 0x01, + kDNSFlag1_RC_ServFail = 0x02, + kDNSFlag1_RC_NXDomain = 0x03, + kDNSFlag1_RC_NotImpl = 0x04, + kDNSFlag1_RC_Refused = 0x05, + kDNSFlag1_RC_YXDomain = 0x06, + kDNSFlag1_RC_YXRRSet = 0x07, + kDNSFlag1_RC_NXRRSet = 0x08, + kDNSFlag1_RC_NotAuth = 0x09, + kDNSFlag1_RC_NotZone = 0x0A +} DNS_Flags; + +typedef enum +{ + TSIG_ErrBadSig = 16, + TSIG_ErrBadKey = 17, + TSIG_ErrBadTime = 18 +} TSIG_ErrorCode; + +// *************************************************************************** +#if COMPILER_LIKES_PRAGMA_MARK +#pragma mark - +#pragma mark - General Utility Functions +#endif + +extern NetworkInterfaceInfo *GetFirstActiveInterface(NetworkInterfaceInfo *intf); +extern mDNSInterfaceID GetNextActiveInterfaceID(const NetworkInterfaceInfo *intf); + +extern mDNSu32 mDNSRandom(mDNSu32 max); // Returns pseudo-random result from zero to max inclusive + +// *************************************************************************** +#if COMPILER_LIKES_PRAGMA_MARK +#pragma mark - +#pragma mark - Domain Name Utility Functions +#endif + +#define mDNSSubTypeLabel "\x04_sub" + +#define mDNSIsDigit(X) ((X) >= '0' && (X) <= '9') +#define mDNSIsUpperCase(X) ((X) >= 'A' && (X) <= 'Z') +#define mDNSIsLowerCase(X) ((X) >= 'a' && (X) <= 'z') +#define mDNSIsLetter(X) (mDNSIsUpperCase(X) || mDNSIsLowerCase(X)) + +#define mDNSValidHostChar(X, notfirst, notlast) (mDNSIsLetter(X) || mDNSIsDigit(X) || ((notfirst) && (notlast) && (X) == '-') ) + +extern mDNSu16 CompressedDomainNameLength(const domainname *const name, const domainname *parent); +extern int CountLabels(const domainname *d); +extern const domainname *SkipLeadingLabels(const domainname *d, int skip); + +extern mDNSu32 TruncateUTF8ToLength(mDNSu8 *string, mDNSu32 length, mDNSu32 max); +extern mDNSBool LabelContainsSuffix(const domainlabel *const name, const mDNSBool RichText); +extern mDNSu32 RemoveLabelSuffix(domainlabel *name, mDNSBool RichText); +extern void AppendLabelSuffix(domainlabel *const name, mDNSu32 val, const mDNSBool RichText); +#define ValidateDomainName(N) (DomainNameLength(N) <= MAX_DOMAIN_NAME) + +// *************************************************************************** +#if COMPILER_LIKES_PRAGMA_MARK +#pragma mark - +#pragma mark - Resource Record Utility Functions +#endif + +// IdenticalResourceRecord returns true if two resources records have +// the same name, type, class, and identical rdata (InterfaceID and TTL may differ) + +// IdenticalSameNameRecord is the same, except it skips the expensive SameDomainName() check, +// which is at its most expensive and least useful in cases where we know in advance that the names match + +// Note: The dominant use of IdenticalResourceRecord is from ProcessQuery(), handling known-answer lists. In this case +// it's common to have a whole bunch or records with exactly the same name (e.g. "_http._tcp.local") but different RDATA. +// The SameDomainName() check is expensive when the names match, and in this case *all* the names match, so we +// used to waste a lot of CPU time verifying that the names match, only then to find that the RDATA is different. +// We observed mDNSResponder spending 30% of its total CPU time on this single task alone. +// By swapping the checks so that we check the RDATA first, we can quickly detect when it's different +// (99% of the time) and then bail out before we waste time on the expensive SameDomainName() check. + +#define IdenticalResourceRecord(r1,r2) ( \ + (r1)->rrtype == (r2)->rrtype && \ + (r1)->rrclass == (r2)->rrclass && \ + (r1)->namehash == (r2)->namehash && \ + (r1)->rdlength == (r2)->rdlength && \ + (r1)->rdatahash == (r2)->rdatahash && \ + SameRDataBody((r1), &(r2)->rdata->u, SameDomainName) && \ + SameDomainName((r1)->name, (r2)->name)) + +#define IdenticalSameNameRecord(r1,r2) ( \ + (r1)->rrtype == (r2)->rrtype && \ + (r1)->rrclass == (r2)->rrclass && \ + (r1)->rdlength == (r2)->rdlength && \ + (r1)->rdatahash == (r2)->rdatahash && \ + SameRDataBody((r1), &(r2)->rdata->u, SameDomainName)) + +// A given RRType answers a QuestionType if RRType is CNAME, or types match, or QuestionType is ANY, +// or the RRType is NSEC and positively asserts the nonexistence of the type being requested +#define RRTypeAnswersQuestionType(R,Q) ((R)->rrtype == kDNSType_CNAME || (R)->rrtype == (Q) || (Q) == kDNSQType_ANY || RRAssertsNonexistence((R),(Q))) +// Unicast NSEC records have the NSEC bit set whereas the multicast NSEC ones don't +#define UNICAST_NSEC(rr) ((rr)->rrtype == kDNSType_NSEC && RRAssertsExistence((rr), kDNSType_NSEC)) + +extern mDNSu32 RDataHashValue(const ResourceRecord *const rr); +extern mDNSBool SameRDataBody(const ResourceRecord *const r1, const RDataBody *const r2, DomainNameComparisonFn *samename); +extern mDNSBool SameNameRecordAnswersQuestion(const ResourceRecord *const rr, const DNSQuestion *const q); +extern mDNSBool ResourceRecordAnswersQuestion(const ResourceRecord *const rr, const DNSQuestion *const q); +extern mDNSBool AnyTypeRecordAnswersQuestion (const ResourceRecord *const rr, const DNSQuestion *const q); +extern mDNSBool ResourceRecordAnswersUnicastResponse(const ResourceRecord *const rr, const DNSQuestion *const q); +extern mDNSBool LocalOnlyRecordAnswersQuestion(AuthRecord *const rr, const DNSQuestion *const q); +extern mDNSu16 GetRDLength(const ResourceRecord *const rr, mDNSBool estimate); +extern mDNSBool ValidateRData(const mDNSu16 rrtype, const mDNSu16 rdlength, const RData *const rd); +extern mStatus DNSNameToLowerCase(domainname *d, domainname *result); + +#define GetRRDomainNameTarget(RR) ( \ + ((RR)->rrtype == kDNSType_NS || (RR)->rrtype == kDNSType_CNAME || (RR)->rrtype == kDNSType_PTR || (RR)->rrtype == kDNSType_DNAME) ? &(RR)->rdata->u.name : \ + ((RR)->rrtype == kDNSType_MX || (RR)->rrtype == kDNSType_AFSDB || (RR)->rrtype == kDNSType_RT || (RR)->rrtype == kDNSType_KX ) ? &(RR)->rdata->u.mx.exchange : \ + ((RR)->rrtype == kDNSType_SRV ) ? &(RR)->rdata->u.srv.target : mDNSNULL ) + +#define LocalRecordReady(X) ((X)->resrec.RecordType != kDNSRecordTypeUnique) + +// *************************************************************************** +#if COMPILER_LIKES_PRAGMA_MARK +#pragma mark - +#pragma mark - DNS Message Creation Functions +#endif + +extern void InitializeDNSMessage(DNSMessageHeader *h, mDNSOpaque16 id, mDNSOpaque16 flags); +extern const mDNSu8 *FindCompressionPointer(const mDNSu8 *const base, const mDNSu8 *const end, const mDNSu8 *const domname); +extern mDNSu8 *putDomainNameAsLabels(const DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, const domainname *const name); +extern mDNSu8 *putRData(const DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, const ResourceRecord *const rr); + +// If we have a single large record to put in the packet, then we allow the packet to be up to 9K bytes, +// but in the normal case we try to keep the packets below 1500 to avoid IP fragmentation on standard Ethernet + +#define AllowedRRSpace(msg) (((msg)->h.numAnswers || (msg)->h.numAuthorities || (msg)->h.numAdditionals) ? NormalMaxDNSMessageData : AbsoluteMaxDNSMessageData) + +extern mDNSu8 *PutResourceRecordTTLWithLimit(DNSMessage *const msg, mDNSu8 *ptr, mDNSu16 *count, ResourceRecord *rr, mDNSu32 ttl, const mDNSu8 *limit); + +#define PutResourceRecordTTL(msg, ptr, count, rr, ttl) \ + PutResourceRecordTTLWithLimit((msg), (ptr), (count), (rr), (ttl), (msg)->data + AllowedRRSpace(msg)) + +#define PutResourceRecordTTLJumbo(msg, ptr, count, rr, ttl) \ + PutResourceRecordTTLWithLimit((msg), (ptr), (count), (rr), (ttl), (msg)->data + AbsoluteMaxDNSMessageData) + +#define PutResourceRecord(MSG, P, C, RR) PutResourceRecordTTL((MSG), (P), (C), (RR), (RR)->rroriginalttl) + +// The PutRR_OS variants assume a local variable 'm', put build the packet at m->omsg, +// and assume local variables 'OwnerRecordSpace' & 'TraceRecordSpace' indicating how many bytes (if any) to reserve to add an OWNER/TRACER option at the end +#define PutRR_OS_TTL(ptr, count, rr, ttl) \ + PutResourceRecordTTLWithLimit(&m->omsg, (ptr), (count), (rr), (ttl), m->omsg.data + AllowedRRSpace(&m->omsg) - OwnerRecordSpace - TraceRecordSpace) + +#define PutRR_OS(P, C, RR) PutRR_OS_TTL((P), (C), (RR), (RR)->rroriginalttl) + +extern mDNSu8 *putQuestion(DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, const domainname *const name, mDNSu16 rrtype, mDNSu16 rrclass); +extern mDNSu8 *putZone(DNSMessage *const msg, mDNSu8 *ptr, mDNSu8 *limit, const domainname *zone, mDNSOpaque16 zoneClass); +extern mDNSu8 *putPrereqNameNotInUse(const domainname *const name, DNSMessage *const msg, mDNSu8 *const ptr, mDNSu8 *const end); +extern mDNSu8 *putDeletionRecord(DNSMessage *msg, mDNSu8 *ptr, ResourceRecord *rr); +extern mDNSu8 *putDeletionRecordWithLimit(DNSMessage *msg, mDNSu8 *ptr, ResourceRecord *rr, mDNSu8 *limit); +extern mDNSu8 *putDeleteRRSetWithLimit(DNSMessage *msg, mDNSu8 *ptr, const domainname *name, mDNSu16 rrtype, mDNSu8 *limit); +extern mDNSu8 *putDeleteAllRRSets(DNSMessage *msg, mDNSu8 *ptr, const domainname *name); +extern mDNSu8 *putUpdateLease(DNSMessage *msg, mDNSu8 *end, mDNSu32 lease); +extern mDNSu8 *putUpdateLeaseWithLimit(DNSMessage *msg, mDNSu8 *ptr, mDNSu32 lease, mDNSu8 *limit); + +extern mDNSu8 *putHINFO(const mDNS *const m, DNSMessage *const msg, mDNSu8 *ptr, DomainAuthInfo *authInfo, mDNSu8 *limit); +extern mDNSu8 *putDNSSECOption(DNSMessage *msg, mDNSu8 *end, mDNSu8 *limit); +extern int baseEncode(char *buffer, int blen, const mDNSu8 *data, int len, int encAlg); +extern void NSEC3Parse(const ResourceRecord *const rr, mDNSu8 **salt, int *hashLength, mDNSu8 **nxtName, int *bitmaplen, mDNSu8 **bitmap); + +extern const mDNSu8 *NSEC3HashName(const domainname *name, rdataNSEC3 *nsec3, const mDNSu8 *AnonData, int AnonDataLen, + const mDNSu8 hash[NSEC3_MAX_HASH_LEN], int *dlen); + +// *************************************************************************** +#if COMPILER_LIKES_PRAGMA_MARK +#pragma mark - +#pragma mark - DNS Message Parsing Functions +#endif + +#define AuthHashSlot(X) (DomainNameHashValue(X) % AUTH_HASH_SLOTS) +#define HashSlot(X) (DomainNameHashValue(X) % CACHE_HASH_SLOTS) +extern mDNSu32 DomainNameHashValue(const domainname *const name); +extern void SetNewRData(ResourceRecord *const rr, RData *NewRData, mDNSu16 rdlength); +extern const mDNSu8 *skipDomainName(const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *const end); +extern const mDNSu8 *getDomainName(const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *const end, + domainname *const name); +extern const mDNSu8 *skipResourceRecord(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end); +extern const mDNSu8 *GetLargeResourceRecord(mDNS *const m, const DNSMessage * const msg, const mDNSu8 *ptr, + const mDNSu8 * end, const mDNSInterfaceID InterfaceID, mDNSu8 RecordType, LargeCacheRecord *const largecr); +extern mDNSBool SetRData(const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *end, + LargeCacheRecord *const largecr, mDNSu16 rdlength); +extern const mDNSu8 *skipQuestion(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end); +extern const mDNSu8 *getQuestion(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end, const mDNSInterfaceID InterfaceID, + DNSQuestion *question); +extern const mDNSu8 *LocateAnswers(const DNSMessage *const msg, const mDNSu8 *const end); +extern const mDNSu8 *LocateAuthorities(const DNSMessage *const msg, const mDNSu8 *const end); +extern const mDNSu8 *LocateAdditionals(const DNSMessage *const msg, const mDNSu8 *const end); +extern const mDNSu8 *LocateOptRR(const DNSMessage *const msg, const mDNSu8 *const end, int minsize); +extern const rdataOPT *GetLLQOptData(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end); +extern mDNSu32 GetPktLease(mDNS *m, DNSMessage *msg, const mDNSu8 *end); +extern void DumpPacket(mDNS *const m, mStatus status, mDNSBool sent, char *transport, + const mDNSAddr *srcaddr, mDNSIPPort srcport, + const mDNSAddr *dstaddr, mDNSIPPort dstport, const DNSMessage *const msg, const mDNSu8 *const end); +extern mDNSBool RRAssertsNonexistence(const ResourceRecord *const rr, mDNSu16 type); +extern mDNSBool RRAssertsExistence(const ResourceRecord *const rr, mDNSu16 type); +extern mDNSBool BitmapTypeCheck(mDNSu8 *bmap, int bitmaplen, mDNSu16 type); + +extern mDNSu16 swap16(mDNSu16 x); +extern mDNSu32 swap32(mDNSu32 x); + +// *************************************************************************** +#if COMPILER_LIKES_PRAGMA_MARK +#pragma mark - +#pragma mark - Packet Sending Functions +#endif + +extern mStatus mDNSSendDNSMessage(mDNS *const m, DNSMessage *const msg, mDNSu8 *end, + mDNSInterfaceID InterfaceID, UDPSocket *src, const mDNSAddr *dst, + mDNSIPPort dstport, TCPSocket *sock, DomainAuthInfo *authInfo, + mDNSBool useBackgroundTrafficClass); + +// *************************************************************************** +#if COMPILER_LIKES_PRAGMA_MARK +#pragma mark - +#pragma mark - RR List Management & Task Management +#endif + +extern void ShowTaskSchedulingError(mDNS *const m); +extern void mDNS_Lock_(mDNS *const m, const char * const functionname); +extern void mDNS_Unlock_(mDNS *const m, const char * const functionname); + +#if defined(_WIN32) + #define __func__ __FUNCTION__ +#endif + +#define mDNS_Lock(X) mDNS_Lock_((X), __func__) + +#define mDNS_Unlock(X) mDNS_Unlock_((X), __func__) + +#define mDNS_CheckLock(X) { 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); } + +#define mDNS_DropLockBeforeCallback() do { m->mDNS_reentrancy++; \ + if (m->mDNS_busy != m->mDNS_reentrancy) LogMsg("%s: Locking Failure! mDNS_busy (%ld) != mDNS_reentrancy (%ld)", __func__, m->mDNS_busy, m->mDNS_reentrancy); \ +} while (0) + +#define mDNS_ReclaimLockAfterCallback() do { \ + if (m->mDNS_busy != m->mDNS_reentrancy) LogMsg("%s: Unlocking Failure! mDNS_busy (%ld) != mDNS_reentrancy (%ld)", __func__, m->mDNS_busy, m->mDNS_reentrancy); \ + m->mDNS_reentrancy--; } while (0) + +#ifdef __cplusplus +} +#endif + +#endif // __DNSCOMMON_H_ |