[apple/mdnsresponder.git] / mDNSCore / DNSCommon.h

/* -*- 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_Subscribe   = 0x06,
    kDNSFlag0_OP_UnSubscribe = 0x07,
    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 *ptr, 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_
Commit	Line	Data
67c8f8a1 A	1	/* -- Mode: C; tab-width: 4 --
67c8f8a1 A	2	*
8e92c31c A	3	* Copyright (c) 2002-2003 Apple Computer, Inc. All rights reserved.
8e92c31c A	4	*
67c8f8a1 A	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
83fb1e36	8	*
67c8f8a1	9	* http://www.apache.org/licenses/LICENSE-2.0
83fb1e36	10	*
67c8f8a1 A	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
8e92c31c	15	* limitations under the License.
263eeeab	16	*/
8e92c31c A	17
	18	#ifndef __DNSCOMMON_H_
	19	#define __DNSCOMMON_H_
	20
7f0064bd	21	#include "mDNSEmbeddedAPI.h"
8e92c31c	22
83fb1e36 A	23	#ifdef __cplusplus
83fb1e36 A	24	extern "C" {
8e92c31c A	25	#endif
8e92c31c A	26
5e65c77f A	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
83fb1e36	33	#define STRINGIFY_ARGUMENT_WITHOUT_EXPANSION(s) # s
5e65c77f A	34	#define STRINGIFY(s) STRINGIFY_ARGUMENT_WITHOUT_EXPANSION(s)
5e65c77f A	35
8e92c31c A	36	// ***************************************************************************
	37	#if COMPILER_LIKES_PRAGMA_MARK
	38	#pragma mark - DNS Protocol Constants
	39	#endif
	40
	41	typedef enum
83fb1e36	42	{
9f221bca A	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_Subscribe = 0x06,
	50	kDNSFlag0_OP_UnSubscribe = 0x07,
	51	kDNSFlag0_OP_Iquery = 0x08,
	52	kDNSFlag0_OP_Status = 0x10,
	53	kDNSFlag0_OP_Unused3 = 0x18,
	54	kDNSFlag0_OP_Notify = 0x20,
	55	kDNSFlag0_OP_Update = 0x28,
83fb1e36 A	56
	57	kDNSFlag0_QROP_Mask = kDNSFlag0_QR_Mask \| kDNSFlag0_OP_Mask,
	58
	59	kDNSFlag0_AA = 0x04, // Authoritative Answer?
	60	kDNSFlag0_TC = 0x02, // Truncated?
	61	kDNSFlag0_RD = 0x01, // Recursion Desired?
	62	kDNSFlag1_RA = 0x80, // Recursion Available?
	63
	64	kDNSFlag1_Zero = 0x40, // Reserved; must be zero
	65	kDNSFlag1_AD = 0x20, // Authentic Data [RFC 2535]
	66	kDNSFlag1_CD = 0x10, // Checking Disabled [RFC 2535]
	67
	68	kDNSFlag1_RC_Mask = 0x0F, // Response code
	69	kDNSFlag1_RC_NoErr = 0x00,
	70	kDNSFlag1_RC_FormErr = 0x01,
	71	kDNSFlag1_RC_ServFail = 0x02,
	72	kDNSFlag1_RC_NXDomain = 0x03,
	73	kDNSFlag1_RC_NotImpl = 0x04,
	74	kDNSFlag1_RC_Refused = 0x05,
	75	kDNSFlag1_RC_YXDomain = 0x06,
	76	kDNSFlag1_RC_YXRRSet = 0x07,
	77	kDNSFlag1_RC_NXRRSet = 0x08,
	78	kDNSFlag1_RC_NotAuth = 0x09,
	79	kDNSFlag1_RC_NotZone = 0x0A
	80	} DNS_Flags;
8e92c31c	81
7f0064bd	82	typedef enum
83fb1e36 A	83	{
	84	TSIG_ErrBadSig = 16,
	85	TSIG_ErrBadKey = 17,
	86	TSIG_ErrBadTime = 18
	87	} TSIG_ErrorCode;
67c8f8a1	88
9f221bca	89
8e92c31c A	90	// ***************************************************************************
	91	#if COMPILER_LIKES_PRAGMA_MARK
	92	#pragma mark -
	93	#pragma mark - General Utility Functions
	94	#endif
	95
32bb7e43	96	extern NetworkInterfaceInfo GetFirstActiveInterface(NetworkInterfaceInfo intf);
8e92c31c A	97	extern mDNSInterfaceID GetNextActiveInterfaceID(const NetworkInterfaceInfo *intf);
8e92c31c A	98
83fb1e36	99	extern mDNSu32 mDNSRandom(mDNSu32 max); // Returns pseudo-random result from zero to max inclusive
8e92c31c A	100
	101	// ***************************************************************************
	102	#if COMPILER_LIKES_PRAGMA_MARK
	103	#pragma mark -
	104	#pragma mark - Domain Name Utility Functions
	105	#endif
67c8f8a1	106
51601d48 A	107	#define mDNSSubTypeLabel "\x04_sub"
51601d48 A	108
32bb7e43	109	#define mDNSIsDigit(X) ((X) >= '0' && (X) <= '9')
8e92c31c A	110	#define mDNSIsUpperCase(X) ((X) >= 'A' && (X) <= 'Z')
8e92c31c A	111	#define mDNSIsLowerCase(X) ((X) >= 'a' && (X) <= 'z')
32bb7e43	112	#define mDNSIsLetter(X) (mDNSIsUpperCase(X) \|\| mDNSIsLowerCase(X))
67c8f8a1	113
32bb7e43	114	#define mDNSValidHostChar(X, notfirst, notlast) (mDNSIsLetter(X) \|\| mDNSIsDigit(X) \|\| ((notfirst) && (notlast) && (X) == '-') )
8e92c31c A	115
8e92c31c A	116	extern mDNSu16 CompressedDomainNameLength(const domainname const name, const domainname parent);
67c8f8a1 A	117	extern int CountLabels(const domainname *d);
67c8f8a1 A	118	extern const domainname SkipLeadingLabels(const domainname d, int skip);
8e92c31c	119
7cb34e5c	120	extern mDNSu32 TruncateUTF8ToLength(mDNSu8 *string, mDNSu32 length, mDNSu32 max);
8e92c31c A	121	extern mDNSBool LabelContainsSuffix(const domainlabel *const name, const mDNSBool RichText);
8e92c31c A	122	extern mDNSu32 RemoveLabelSuffix(domainlabel *name, mDNSBool RichText);
263eeeab	123	extern void AppendLabelSuffix(domainlabel *const name, mDNSu32 val, const mDNSBool RichText);
8e92c31c A	124	#define ValidateDomainName(N) (DomainNameLength(N) <= MAX_DOMAIN_NAME)
8e92c31c A	125
8e92c31c A	126	// ***************************************************************************
	127	#if COMPILER_LIKES_PRAGMA_MARK
	128	#pragma mark -
	129	#pragma mark - Resource Record Utility Functions
	130	#endif
	131
030b743d A	132	// IdenticalResourceRecord returns true if two resources records have
	133	// the same name, type, class, and identical rdata (InterfaceID and TTL may differ)
	134
	135	// IdenticalSameNameRecord is the same, except it skips the expensive SameDomainName() check,
	136	// which is at its most expensive and least useful in cases where we know in advance that the names match
	137
	138	// Note: The dominant use of IdenticalResourceRecord is from ProcessQuery(), handling known-answer lists. In this case
	139	// it's common to have a whole bunch or records with exactly the same name (e.g. "_http._tcp.local") but different RDATA.
	140	// The SameDomainName() check is expensive when the names match, and in this case all the names match, so we
	141	// used to waste a lot of CPU time verifying that the names match, only then to find that the RDATA is different.
	142	// We observed mDNSResponder spending 30% of its total CPU time on this single task alone.
	143	// By swapping the checks so that we check the RDATA first, we can quickly detect when it's different
	144	// (99% of the time) and then bail out before we waste time on the expensive SameDomainName() check.
	145
	146	#define IdenticalResourceRecord(r1,r2) ( \
83fb1e36 A	147	(r1)->rrtype == (r2)->rrtype && \
	148	(r1)->rrclass == (r2)->rrclass && \
	149	(r1)->namehash == (r2)->namehash && \
	150	(r1)->rdlength == (r2)->rdlength && \
	151	(r1)->rdatahash == (r2)->rdatahash && \
	152	SameRDataBody((r1), &(r2)->rdata->u, SameDomainName) && \
	153	SameDomainName((r1)->name, (r2)->name))
030b743d A	154
030b743d A	155	#define IdenticalSameNameRecord(r1,r2) ( \
83fb1e36 A	156	(r1)->rrtype == (r2)->rrtype && \
	157	(r1)->rrclass == (r2)->rrclass && \
	158	(r1)->rdlength == (r2)->rdlength && \
	159	(r1)->rdatahash == (r2)->rdatahash && \
	160	SameRDataBody((r1), &(r2)->rdata->u, SameDomainName))
030b743d	161
32bb7e43 A	162	// A given RRType answers a QuestionType if RRType is CNAME, or types match, or QuestionType is ANY,
32bb7e43 A	163	// or the RRType is NSEC and positively asserts the nonexistence of the type being requested
263eeeab	164	#define RRTypeAnswersQuestionType(R,Q) ((R)->rrtype == kDNSType_CNAME \|\| (R)->rrtype == (Q) \|\| (Q) == kDNSQType_ANY \|\| RRAssertsNonexistence((R),(Q)))
83fb1e36 A	165	// Unicast NSEC records have the NSEC bit set whereas the multicast NSEC ones don't
83fb1e36 A	166	#define UNICAST_NSEC(rr) ((rr)->rrtype == kDNSType_NSEC && RRAssertsExistence((rr), kDNSType_NSEC))
32bb7e43	167
030b743d	168	extern mDNSu32 RDataHashValue(const ResourceRecord *const rr);
263eeeab	169	extern mDNSBool SameRDataBody(const ResourceRecord const r1, const RDataBody const r2, DomainNameComparisonFn *samename);
67c8f8a1	170	extern mDNSBool SameNameRecordAnswersQuestion(const ResourceRecord const rr, const DNSQuestion const q);
32bb7e43 A	171	extern mDNSBool ResourceRecordAnswersQuestion(const ResourceRecord const rr, const DNSQuestion const q);
32bb7e43 A	172	extern mDNSBool AnyTypeRecordAnswersQuestion (const ResourceRecord const rr, const DNSQuestion const q);
3c3ba2cc	173	extern mDNSBool ResourceRecordAnswersUnicastResponse(const ResourceRecord const rr, const DNSQuestion const q);
294beb6e	174	extern mDNSBool LocalOnlyRecordAnswersQuestion(AuthRecord const rr, const DNSQuestion const q);
8e92c31c	175	extern mDNSu16 GetRDLength(const ResourceRecord *const rr, mDNSBool estimate);
67c8f8a1	176	extern mDNSBool ValidateRData(const mDNSu16 rrtype, const mDNSu16 rdlength, const RData *const rd);
51601d48	177	extern mStatus DNSNameToLowerCase(domainname d, domainname result);
8e92c31c A	178
8e92c31c A	179	#define GetRRDomainNameTarget(RR) ( \
83fb1e36 A	180	((RR)->rrtype == kDNSType_NS \|\| (RR)->rrtype == kDNSType_CNAME \|\| (RR)->rrtype == kDNSType_PTR \|\| (RR)->rrtype == kDNSType_DNAME) ? &(RR)->rdata->u.name : \
	181	((RR)->rrtype == kDNSType_MX \|\| (RR)->rrtype == kDNSType_AFSDB \|\| (RR)->rrtype == kDNSType_RT \|\| (RR)->rrtype == kDNSType_KX ) ? &(RR)->rdata->u.mx.exchange : \
	182	((RR)->rrtype == kDNSType_SRV ) ? &(RR)->rdata->u.srv.target : mDNSNULL )
8e92c31c	183
263eeeab	184	#define LocalRecordReady(X) ((X)->resrec.RecordType != kDNSRecordTypeUnique)
8e92c31c	185
8e92c31c A	186	// ***************************************************************************
	187	#if COMPILER_LIKES_PRAGMA_MARK
	188	#pragma mark -
8e92c31c A	189	#pragma mark - DNS Message Creation Functions
	190	#endif
	191
	192	extern void InitializeDNSMessage(DNSMessageHeader *h, mDNSOpaque16 id, mDNSOpaque16 flags);
	193	extern const mDNSu8 FindCompressionPointer(const mDNSu8 const base, const mDNSu8 const end, const mDNSu8 const domname);
8e92c31c	194	extern mDNSu8 putDomainNameAsLabels(const DNSMessage const msg, mDNSu8 ptr, const mDNSu8 const limit, const domainname *const name);
67c8f8a1	195	extern mDNSu8 putRData(const DNSMessage const msg, mDNSu8 ptr, const mDNSu8 const limit, const ResourceRecord *const rr);
8e92c31c	196
7f0064bd	197	// If we have a single large record to put in the packet, then we allow the packet to be up to 9K bytes,
67c8f8a1	198	// but in the normal case we try to keep the packets below 1500 to avoid IP fragmentation on standard Ethernet
ca3eca6b A	199
	200	#define AllowedRRSpace(msg) (((msg)->h.numAnswers \|\| (msg)->h.numAuthorities \|\| (msg)->h.numAdditionals) ? NormalMaxDNSMessageData : AbsoluteMaxDNSMessageData)
	201
7f0064bd	202	extern mDNSu8 PutResourceRecordTTLWithLimit(DNSMessage const msg, mDNSu8 ptr, mDNSu16 count, ResourceRecord rr, mDNSu32 ttl, const mDNSu8 limit);
32bb7e43 A	203
32bb7e43 A	204	#define PutResourceRecordTTL(msg, ptr, count, rr, ttl) \
83fb1e36	205	PutResourceRecordTTLWithLimit((msg), (ptr), (count), (rr), (ttl), (msg)->data + AllowedRRSpace(msg))
ca3eca6b	206
32bb7e43	207	#define PutResourceRecordTTLJumbo(msg, ptr, count, rr, ttl) \
83fb1e36	208	PutResourceRecordTTLWithLimit((msg), (ptr), (count), (rr), (ttl), (msg)->data + AbsoluteMaxDNSMessageData)
ca3eca6b	209
32bb7e43	210	#define PutResourceRecord(MSG, P, C, RR) PutResourceRecordTTL((MSG), (P), (C), (RR), (RR)->rroriginalttl)
8e92c31c	211
ca3eca6b	212	// The PutRR_OS variants assume a local variable 'm', put build the packet at m->omsg,
51601d48	213	// and assume local variables 'OwnerRecordSpace' & 'TraceRecordSpace' indicating how many bytes (if any) to reserve to add an OWNER/TRACER option at the end
ca3eca6b	214	#define PutRR_OS_TTL(ptr, count, rr, ttl) \
51601d48	215	PutResourceRecordTTLWithLimit(&m->omsg, (ptr), (count), (rr), (ttl), m->omsg.data + AllowedRRSpace(&m->omsg) - OwnerRecordSpace - TraceRecordSpace)
ca3eca6b A	216
	217	#define PutRR_OS(P, C, RR) PutRR_OS_TTL((P), (C), (RR), (RR)->rroriginalttl)
	218
8e92c31c	219	extern mDNSu8 putQuestion(DNSMessage const msg, mDNSu8 ptr, const mDNSu8 const limit, const domainname *const name, mDNSu16 rrtype, mDNSu16 rrclass);
7f0064bd	220	extern mDNSu8 putZone(DNSMessage const msg, mDNSu8 ptr, mDNSu8 limit, const domainname *zone, mDNSOpaque16 zoneClass);
263eeeab	221	extern mDNSu8 putPrereqNameNotInUse(const domainname const name, DNSMessage const msg, mDNSu8 const ptr, mDNSu8 *const end);
7f0064bd	222	extern mDNSu8 putDeletionRecord(DNSMessage msg, mDNSu8 ptr, ResourceRecord rr);
263eeeab A	223	extern mDNSu8 putDeletionRecordWithLimit(DNSMessage msg, mDNSu8 ptr, ResourceRecord rr, mDNSu8 *limit);
263eeeab A	224	extern mDNSu8 putDeleteRRSetWithLimit(DNSMessage msg, mDNSu8 ptr, const domainname name, mDNSu16 rrtype, mDNSu8 *limit);
7f0064bd	225	extern mDNSu8 putDeleteAllRRSets(DNSMessage msg, mDNSu8 ptr, const domainname name);
9f221bca	226	extern mDNSu8 putUpdateLease(DNSMessage msg, mDNSu8 *ptr, mDNSu32 lease);
263eeeab	227	extern mDNSu8 putUpdateLeaseWithLimit(DNSMessage msg, mDNSu8 ptr, mDNSu32 lease, mDNSu8 limit);
8e92c31c	228
263eeeab	229	extern mDNSu8 putHINFO(const mDNS const m, DNSMessage const msg, mDNSu8 ptr, DomainAuthInfo authInfo, mDNSu8 limit);
51601d48 A	230	extern mDNSu8 putDNSSECOption(DNSMessage msg, mDNSu8 end, mDNSu8 limit);
	231	extern int baseEncode(char buffer, int blen, const mDNSu8 data, int len, int encAlg);
	232	extern void NSEC3Parse(const ResourceRecord const rr, mDNSu8 salt, int hashLength, mDNSu8 *nxtName, int bitmaplen, mDNSu8 **bitmap);
	233
	234	extern const mDNSu8 NSEC3HashName(const domainname name, rdataNSEC3 nsec3, const mDNSu8 AnonData, int AnonDataLen,
	235	const mDNSu8 hash[NSEC3_MAX_HASH_LEN], int *dlen);
5e65c77f	236
8e92c31c A	237	// ***************************************************************************
	238	#if COMPILER_LIKES_PRAGMA_MARK
	239	#pragma mark -
	240	#pragma mark - DNS Message Parsing Functions
	241	#endif
	242
294beb6e	243	#define AuthHashSlot(X) (DomainNameHashValue(X) % AUTH_HASH_SLOTS)
67c8f8a1	244	#define HashSlot(X) (DomainNameHashValue(X) % CACHE_HASH_SLOTS)
8e92c31c	245	extern mDNSu32 DomainNameHashValue(const domainname *const name);
8e92c31c	246	extern void SetNewRData(ResourceRecord const rr, RData NewRData, mDNSu16 rdlength);
8e92c31c	247	extern const mDNSu8 skipDomainName(const DNSMessage const msg, const mDNSu8 ptr, const mDNSu8 const end);
8e92c31c	248	extern const mDNSu8 getDomainName(const DNSMessage const msg, const mDNSu8 ptr, const mDNSu8 const end,
83fb1e36	249	domainname *const name);
8e92c31c	250	extern const mDNSu8 skipResourceRecord(const DNSMessage msg, const mDNSu8 ptr, const mDNSu8 end);
67c8f8a1	251	extern const mDNSu8 GetLargeResourceRecord(mDNS const m, const DNSMessage * const msg, const mDNSu8 *ptr,
83fb1e36 A	252	const mDNSu8 * end, const mDNSInterfaceID InterfaceID, mDNSu8 RecordType, LargeCacheRecord *const largecr);
	253	extern mDNSBool SetRData(const DNSMessage const msg, const mDNSu8 ptr, const mDNSu8 *end,
	254	LargeCacheRecord *const largecr, mDNSu16 rdlength);
8e92c31c	255	extern const mDNSu8 skipQuestion(const DNSMessage msg, const mDNSu8 ptr, const mDNSu8 end);
8e92c31c	256	extern const mDNSu8 getQuestion(const DNSMessage msg, const mDNSu8 ptr, const mDNSu8 end, const mDNSInterfaceID InterfaceID,
83fb1e36	257	DNSQuestion *question);
8e92c31c	258	extern const mDNSu8 LocateAnswers(const DNSMessage const msg, const mDNSu8 *const end);
8e92c31c	259	extern const mDNSu8 LocateAuthorities(const DNSMessage const msg, const mDNSu8 *const end);
8e92c31c	260	extern const mDNSu8 LocateAdditionals(const DNSMessage const msg, const mDNSu8 *const end);
32bb7e43	261	extern const mDNSu8 LocateOptRR(const DNSMessage const msg, const mDNSu8 *const end, int minsize);
67c8f8a1	262	extern const rdataOPT GetLLQOptData(mDNS const m, const DNSMessage const msg, const mDNSu8 const end);
67c8f8a1	263	extern mDNSu32 GetPktLease(mDNS m, DNSMessage msg, const mDNSu8 *end);
32bb7e43	264	extern void DumpPacket(mDNS const m, mStatus status, mDNSBool sent, char transport,
83fb1e36 A	265	const mDNSAddr *srcaddr, mDNSIPPort srcport,
	266	const mDNSAddr dstaddr, mDNSIPPort dstport, const DNSMessage const msg, const mDNSu8 *const end);
	267	extern mDNSBool RRAssertsNonexistence(const ResourceRecord *const rr, mDNSu16 type);
	268	extern mDNSBool RRAssertsExistence(const ResourceRecord *const rr, mDNSu16 type);
51601d48	269	extern mDNSBool BitmapTypeCheck(mDNSu8 *bmap, int bitmaplen, mDNSu16 type);
83fb1e36 A	270
	271	extern mDNSu16 swap16(mDNSu16 x);
	272	extern mDNSu32 swap32(mDNSu32 x);
8e92c31c	273
8e92c31c A	274	// ***************************************************************************
	275	#if COMPILER_LIKES_PRAGMA_MARK
	276	#pragma mark -
8e92c31c A	277	#pragma mark - Packet Sending Functions
	278	#endif
	279
67c8f8a1	280	extern mStatus mDNSSendDNSMessage(mDNS const m, DNSMessage const msg, mDNSu8 *end,
83fb1e36 A	281	mDNSInterfaceID InterfaceID, UDPSocket src, const mDNSAddr dst,
	282	mDNSIPPort dstport, TCPSocket sock, DomainAuthInfo authInfo,
	283	mDNSBool useBackgroundTrafficClass);
7f0064bd A	284
	285	// ***************************************************************************
	286	#if COMPILER_LIKES_PRAGMA_MARK
	287	#pragma mark -
	288	#pragma mark - RR List Management & Task Management
	289	#endif
	290
32bb7e43	291	extern void ShowTaskSchedulingError(mDNS *const m);
263eeeab A	292	extern void mDNS_Lock_(mDNS const m, const char const functionname);
263eeeab A	293	extern void mDNS_Unlock_(mDNS const m, const char const functionname);
67c8f8a1	294
32bb7e43 A	295	#if defined(_WIN32)
	296	#define __func__ __FUNCTION__
	297	#endif
	298
263eeeab	299	#define mDNS_Lock(X) mDNS_Lock_((X), __func__)
67c8f8a1	300
263eeeab	301	#define mDNS_Unlock(X) mDNS_Unlock_((X), __func__)
67c8f8a1	302
9f221bca A	303	#define mDNS_CheckLock(X) \
9f221bca A	304	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)
83fb1e36	305
67c8f8a1	306	#define mDNS_DropLockBeforeCallback() do { m->mDNS_reentrancy++; \
9f221bca A	307	if (m->mDNS_busy != m->mDNS_reentrancy) LogMsg("%s: Locking Failure! mDNS_busy (%ld) != mDNS_reentrancy (%ld)", __func__, m->mDNS_busy, m->mDNS_reentrancy); \
9f221bca A	308	} while (0)
67c8f8a1 A	309
67c8f8a1 A	310	#define mDNS_ReclaimLockAfterCallback() do { \
9f221bca A	311	if (m->mDNS_busy != m->mDNS_reentrancy) LogMsg("%s: Unlocking Failure! mDNS_busy (%ld) != mDNS_reentrancy (%ld)", __func__, m->mDNS_busy, m->mDNS_reentrancy); \
9f221bca A	312	m->mDNS_reentrancy--; } while (0)
283ee3ff	313
83fb1e36 A	314	#ifdef __cplusplus
83fb1e36 A	315	}
8e92c31c A	316	#endif
	317
	318	#endif // __DNSCOMMON_H_