[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_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 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)))
#define RRAssertsNonexistence(R,T) ((R)->rrtype == kDNSType_NSEC && (T) < kDNSQType_ANY && !((R)->rdata->u.nsec.bitmap[(T)>>3] & (128 >> ((T)&7))))

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 UnicastResourceRecordAnswersQuestion(const ResourceRecord *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);

#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 a local variable 'OwnerRecordSpace' indicating how many bytes (if any) to reserve to add an OWNER 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)

#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);

// ***************************************************************************
#if COMPILER_LIKES_PRAGMA_MARK
#pragma mark -
#pragma mark - DNS Message Parsing Functions
#endif

#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 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);

// ***************************************************************************
#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);

// ***************************************************************************
#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_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
8e92c31c	8	*
67c8f8a1	9	* http://www.apache.org/licenses/LICENSE-2.0
8e92c31c	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 A	22
	23	#ifdef __cplusplus
	24	extern "C" {
	25	#endif
	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
	33	#define STRINGIFY_ARGUMENT_WITHOUT_EXPANSION(s) #s
	34	#define STRINGIFY(s) STRINGIFY_ARGUMENT_WITHOUT_EXPANSION(s)
	35
8e92c31c A	36	// ***************************************************************************
	37	#if COMPILER_LIKES_PRAGMA_MARK
	38	#pragma mark - DNS Protocol Constants
	39	#endif
	40
	41	typedef enum
	42	{
	43	kDNSFlag0_QR_Mask = 0x80, // Query or response?
	44	kDNSFlag0_QR_Query = 0x00,
	45	kDNSFlag0_QR_Response = 0x80,
67c8f8a1	46
8e92c31c A	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,
67c8f8a1	54
8e92c31c	55	kDNSFlag0_QROP_Mask = kDNSFlag0_QR_Mask \| kDNSFlag0_OP_Mask,
67c8f8a1	56
8e92c31c A	57	kDNSFlag0_AA = 0x04, // Authoritative Answer?
	58	kDNSFlag0_TC = 0x02, // Truncated?
	59	kDNSFlag0_RD = 0x01, // Recursion Desired?
	60	kDNSFlag1_RA = 0x80, // Recursion Available?
67c8f8a1	61
8e92c31c A	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
67c8f8a1	66	kDNSFlag1_RC_Mask = 0x0F, // Response code
8e92c31c	67	kDNSFlag1_RC_NoErr = 0x00,
32bb7e43 A	68	kDNSFlag1_RC_FormErr = 0x01,
32bb7e43 A	69	kDNSFlag1_RC_ServFail = 0x02,
8e92c31c A	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
7f0064bd A	80	typedef enum
	81	{
	82	TSIG_ErrBadSig = 16,
	83	TSIG_ErrBadKey = 17,
	84	TSIG_ErrBadTime = 18
	85	} TSIG_ErrorCode;
67c8f8a1	86
8e92c31c A	87	// ***************************************************************************
	88	#if COMPILER_LIKES_PRAGMA_MARK
	89	#pragma mark -
	90	#pragma mark - General Utility Functions
	91	#endif
	92
32bb7e43	93	extern NetworkInterfaceInfo GetFirstActiveInterface(NetworkInterfaceInfo intf);
8e92c31c A	94	extern mDNSInterfaceID GetNextActiveInterfaceID(const NetworkInterfaceInfo *intf);
8e92c31c A	95
67c8f8a1	96	extern mDNSu32 mDNSRandom(mDNSu32 max); // Returns pseudo-random result from zero to max inclusive
8e92c31c A	97
	98	// ***************************************************************************
	99	#if COMPILER_LIKES_PRAGMA_MARK
	100	#pragma mark -
	101	#pragma mark - Domain Name Utility Functions
	102	#endif
67c8f8a1	103
32bb7e43	104	#define mDNSIsDigit(X) ((X) >= '0' && (X) <= '9')
8e92c31c A	105	#define mDNSIsUpperCase(X) ((X) >= 'A' && (X) <= 'Z')
8e92c31c A	106	#define mDNSIsLowerCase(X) ((X) >= 'a' && (X) <= 'z')
32bb7e43	107	#define mDNSIsLetter(X) (mDNSIsUpperCase(X) \|\| mDNSIsLowerCase(X))
67c8f8a1	108
32bb7e43	109	#define mDNSValidHostChar(X, notfirst, notlast) (mDNSIsLetter(X) \|\| mDNSIsDigit(X) \|\| ((notfirst) && (notlast) && (X) == '-') )
8e92c31c A	110
8e92c31c A	111	extern mDNSu16 CompressedDomainNameLength(const domainname const name, const domainname parent);
67c8f8a1 A	112	extern int CountLabels(const domainname *d);
67c8f8a1 A	113	extern const domainname SkipLeadingLabels(const domainname d, int skip);
8e92c31c	114
7cb34e5c	115	extern mDNSu32 TruncateUTF8ToLength(mDNSu8 *string, mDNSu32 length, mDNSu32 max);
8e92c31c A	116	extern mDNSBool LabelContainsSuffix(const domainlabel *const name, const mDNSBool RichText);
8e92c31c A	117	extern mDNSu32 RemoveLabelSuffix(domainlabel *name, mDNSBool RichText);
263eeeab	118	extern void AppendLabelSuffix(domainlabel *const name, mDNSu32 val, const mDNSBool RichText);
8e92c31c A	119	#define ValidateDomainName(N) (DomainNameLength(N) <= MAX_DOMAIN_NAME)
8e92c31c A	120
8e92c31c A	121	// ***************************************************************************
	122	#if COMPILER_LIKES_PRAGMA_MARK
	123	#pragma mark -
	124	#pragma mark - Resource Record Utility Functions
	125	#endif
	126
030b743d A	127	// IdenticalResourceRecord returns true if two resources records have
	128	// the same name, type, class, and identical rdata (InterfaceID and TTL may differ)
	129
	130	// IdenticalSameNameRecord is the same, except it skips the expensive SameDomainName() check,
	131	// which is at its most expensive and least useful in cases where we know in advance that the names match
	132
	133	// Note: The dominant use of IdenticalResourceRecord is from ProcessQuery(), handling known-answer lists. In this case
	134	// it's common to have a whole bunch or records with exactly the same name (e.g. "_http._tcp.local") but different RDATA.
	135	// The SameDomainName() check is expensive when the names match, and in this case all the names match, so we
	136	// used to waste a lot of CPU time verifying that the names match, only then to find that the RDATA is different.
	137	// We observed mDNSResponder spending 30% of its total CPU time on this single task alone.
	138	// By swapping the checks so that we check the RDATA first, we can quickly detect when it's different
	139	// (99% of the time) and then bail out before we waste time on the expensive SameDomainName() check.
	140
	141	#define IdenticalResourceRecord(r1,r2) ( \
	142	(r1)->rrtype == (r2)->rrtype && \
	143	(r1)->rrclass == (r2)->rrclass && \
	144	(r1)->namehash == (r2)->namehash && \
	145	(r1)->rdlength == (r2)->rdlength && \
	146	(r1)->rdatahash == (r2)->rdatahash && \
263eeeab	147	SameRDataBody((r1), &(r2)->rdata->u, SameDomainName) && \
030b743d A	148	SameDomainName((r1)->name, (r2)->name))
	149
	150	#define IdenticalSameNameRecord(r1,r2) ( \
	151	(r1)->rrtype == (r2)->rrtype && \
	152	(r1)->rrclass == (r2)->rrclass && \
	153	(r1)->rdlength == (r2)->rdlength && \
	154	(r1)->rdatahash == (r2)->rdatahash && \
263eeeab	155	SameRDataBody((r1), &(r2)->rdata->u, SameDomainName))
030b743d	156
32bb7e43 A	157	// A given RRType answers a QuestionType if RRType is CNAME, or types match, or QuestionType is ANY,
32bb7e43 A	158	// or the RRType is NSEC and positively asserts the nonexistence of the type being requested
263eeeab	159	#define RRTypeAnswersQuestionType(R,Q) ((R)->rrtype == kDNSType_CNAME \|\| (R)->rrtype == (Q) \|\| (Q) == kDNSQType_ANY \|\| RRAssertsNonexistence((R),(Q)))
32bb7e43 A	160	#define RRAssertsNonexistence(R,T) ((R)->rrtype == kDNSType_NSEC && (T) < kDNSQType_ANY && !((R)->rdata->u.nsec.bitmap[(T)>>3] & (128 >> ((T)&7))))
32bb7e43 A	161
030b743d	162	extern mDNSu32 RDataHashValue(const ResourceRecord *const rr);
263eeeab	163	extern mDNSBool SameRDataBody(const ResourceRecord const r1, const RDataBody const r2, DomainNameComparisonFn *samename);
67c8f8a1	164	extern mDNSBool SameNameRecordAnswersQuestion(const ResourceRecord const rr, const DNSQuestion const q);
32bb7e43 A	165	extern mDNSBool ResourceRecordAnswersQuestion(const ResourceRecord const rr, const DNSQuestion const q);
32bb7e43 A	166	extern mDNSBool AnyTypeRecordAnswersQuestion (const ResourceRecord const rr, const DNSQuestion const q);
263eeeab	167	extern mDNSBool UnicastResourceRecordAnswersQuestion(const ResourceRecord const rr, const DNSQuestion const q);
8e92c31c	168	extern mDNSu16 GetRDLength(const ResourceRecord *const rr, mDNSBool estimate);
67c8f8a1	169	extern mDNSBool ValidateRData(const mDNSu16 rrtype, const mDNSu16 rdlength, const RData *const rd);
8e92c31c A	170
8e92c31c A	171	#define GetRRDomainNameTarget(RR) ( \
030b743d A	172	((RR)->rrtype == kDNSType_NS \|\| (RR)->rrtype == kDNSType_CNAME \|\| (RR)->rrtype == kDNSType_PTR \|\| (RR)->rrtype == kDNSType_DNAME) ? &(RR)->rdata->u.name : \
030b743d A	173	((RR)->rrtype == kDNSType_MX \|\| (RR)->rrtype == kDNSType_AFSDB \|\| (RR)->rrtype == kDNSType_RT \|\| (RR)->rrtype == kDNSType_KX ) ? &(RR)->rdata->u.mx.exchange : \
8e92c31c A	174	((RR)->rrtype == kDNSType_SRV ) ? &(RR)->rdata->u.srv.target : mDNSNULL )
8e92c31c A	175
263eeeab	176	#define LocalRecordReady(X) ((X)->resrec.RecordType != kDNSRecordTypeUnique)
8e92c31c	177
8e92c31c A	178	// ***************************************************************************
	179	#if COMPILER_LIKES_PRAGMA_MARK
	180	#pragma mark -
8e92c31c A	181	#pragma mark - DNS Message Creation Functions
	182	#endif
	183
	184	extern void InitializeDNSMessage(DNSMessageHeader *h, mDNSOpaque16 id, mDNSOpaque16 flags);
	185	extern const mDNSu8 FindCompressionPointer(const mDNSu8 const base, const mDNSu8 const end, const mDNSu8 const domname);
8e92c31c	186	extern mDNSu8 putDomainNameAsLabels(const DNSMessage const msg, mDNSu8 ptr, const mDNSu8 const limit, const domainname *const name);
67c8f8a1	187	extern mDNSu8 putRData(const DNSMessage const msg, mDNSu8 ptr, const mDNSu8 const limit, const ResourceRecord *const rr);
8e92c31c	188
7f0064bd	189	// If we have a single large record to put in the packet, then we allow the packet to be up to 9K bytes,
67c8f8a1	190	// but in the normal case we try to keep the packets below 1500 to avoid IP fragmentation on standard Ethernet
ca3eca6b A	191
	192	#define AllowedRRSpace(msg) (((msg)->h.numAnswers \|\| (msg)->h.numAuthorities \|\| (msg)->h.numAdditionals) ? NormalMaxDNSMessageData : AbsoluteMaxDNSMessageData)
	193
7f0064bd	194	extern mDNSu8 PutResourceRecordTTLWithLimit(DNSMessage const msg, mDNSu8 ptr, mDNSu16 count, ResourceRecord rr, mDNSu32 ttl, const mDNSu8 limit);
32bb7e43 A	195
32bb7e43 A	196	#define PutResourceRecordTTL(msg, ptr, count, rr, ttl) \
ca3eca6b A	197	PutResourceRecordTTLWithLimit((msg), (ptr), (count), (rr), (ttl), (msg)->data + AllowedRRSpace(msg))
ca3eca6b A	198
32bb7e43 A	199	#define PutResourceRecordTTLJumbo(msg, ptr, count, rr, ttl) \
32bb7e43 A	200	PutResourceRecordTTLWithLimit((msg), (ptr), (count), (rr), (ttl), (msg)->data + AbsoluteMaxDNSMessageData)
ca3eca6b	201
32bb7e43	202	#define PutResourceRecord(MSG, P, C, RR) PutResourceRecordTTL((MSG), (P), (C), (RR), (RR)->rroriginalttl)
8e92c31c	203
ca3eca6b A	204	// The PutRR_OS variants assume a local variable 'm', put build the packet at m->omsg,
	205	// and assume a local variable 'OwnerRecordSpace' indicating how many bytes (if any) to reserve to add an OWNER option at the end
	206	#define PutRR_OS_TTL(ptr, count, rr, ttl) \
	207	PutResourceRecordTTLWithLimit(&m->omsg, (ptr), (count), (rr), (ttl), m->omsg.data + AllowedRRSpace(&m->omsg) - OwnerRecordSpace)
	208
	209	#define PutRR_OS(P, C, RR) PutRR_OS_TTL((P), (C), (RR), (RR)->rroriginalttl)
	210
8e92c31c	211	extern mDNSu8 putQuestion(DNSMessage const msg, mDNSu8 ptr, const mDNSu8 const limit, const domainname *const name, mDNSu16 rrtype, mDNSu16 rrclass);
7f0064bd	212	extern mDNSu8 putZone(DNSMessage const msg, mDNSu8 ptr, mDNSu8 limit, const domainname *zone, mDNSOpaque16 zoneClass);
263eeeab	213	extern mDNSu8 putPrereqNameNotInUse(const domainname const name, DNSMessage const msg, mDNSu8 const ptr, mDNSu8 *const end);
7f0064bd	214	extern mDNSu8 putDeletionRecord(DNSMessage msg, mDNSu8 ptr, ResourceRecord rr);
263eeeab A	215	extern mDNSu8 putDeletionRecordWithLimit(DNSMessage msg, mDNSu8 ptr, ResourceRecord rr, mDNSu8 *limit);
263eeeab A	216	extern mDNSu8 putDeleteRRSetWithLimit(DNSMessage msg, mDNSu8 ptr, const domainname name, mDNSu16 rrtype, mDNSu8 *limit);
7f0064bd	217	extern mDNSu8 putDeleteAllRRSets(DNSMessage msg, mDNSu8 ptr, const domainname name);
7f0064bd	218	extern mDNSu8 putUpdateLease(DNSMessage msg, mDNSu8 *end, mDNSu32 lease);
263eeeab	219	extern mDNSu8 putUpdateLeaseWithLimit(DNSMessage msg, mDNSu8 ptr, mDNSu32 lease, mDNSu8 limit);
8e92c31c	220
263eeeab	221	extern mDNSu8 putHINFO(const mDNS const m, DNSMessage const msg, mDNSu8 ptr, DomainAuthInfo authInfo, mDNSu8 limit);
5e65c77f	222
8e92c31c A	223	// ***************************************************************************
	224	#if COMPILER_LIKES_PRAGMA_MARK
	225	#pragma mark -
	226	#pragma mark - DNS Message Parsing Functions
	227	#endif
	228
67c8f8a1	229	#define HashSlot(X) (DomainNameHashValue(X) % CACHE_HASH_SLOTS)
8e92c31c	230	extern mDNSu32 DomainNameHashValue(const domainname *const name);
8e92c31c	231	extern void SetNewRData(ResourceRecord const rr, RData NewRData, mDNSu16 rdlength);
8e92c31c	232	extern const mDNSu8 skipDomainName(const DNSMessage const msg, const mDNSu8 ptr, const mDNSu8 const end);
8e92c31c A	233	extern const mDNSu8 getDomainName(const DNSMessage const msg, const mDNSu8 ptr, const mDNSu8 const end,
8e92c31c A	234	domainname *const name);
8e92c31c	235	extern const mDNSu8 skipResourceRecord(const DNSMessage msg, const mDNSu8 ptr, const mDNSu8 end);
67c8f8a1	236	extern const mDNSu8 GetLargeResourceRecord(mDNS const m, const DNSMessage * const msg, const mDNSu8 *ptr,
263eeeab	237	const mDNSu8 * end, const mDNSInterfaceID InterfaceID, mDNSu8 RecordType, LargeCacheRecord *const largecr);
8e92c31c	238	extern const mDNSu8 skipQuestion(const DNSMessage msg, const mDNSu8 ptr, const mDNSu8 end);
8e92c31c A	239	extern const mDNSu8 getQuestion(const DNSMessage msg, const mDNSu8 ptr, const mDNSu8 end, const mDNSInterfaceID InterfaceID,
8e92c31c A	240	DNSQuestion *question);
8e92c31c	241	extern const mDNSu8 LocateAnswers(const DNSMessage const msg, const mDNSu8 *const end);
8e92c31c	242	extern const mDNSu8 LocateAuthorities(const DNSMessage const msg, const mDNSu8 *const end);
8e92c31c	243	extern const mDNSu8 LocateAdditionals(const DNSMessage const msg, const mDNSu8 *const end);
32bb7e43	244	extern const mDNSu8 LocateOptRR(const DNSMessage const msg, const mDNSu8 *const end, int minsize);
67c8f8a1	245	extern const rdataOPT GetLLQOptData(mDNS const m, const DNSMessage const msg, const mDNSu8 const end);
67c8f8a1	246	extern mDNSu32 GetPktLease(mDNS m, DNSMessage msg, const mDNSu8 *end);
32bb7e43	247	extern void DumpPacket(mDNS const m, mStatus status, mDNSBool sent, char transport,
9f29194f A	248	const mDNSAddr *srcaddr, mDNSIPPort srcport,
9f29194f A	249	const mDNSAddr dstaddr, mDNSIPPort dstport, const DNSMessage const msg, const mDNSu8 *const end);
8e92c31c	250
8e92c31c A	251	// ***************************************************************************
	252	#if COMPILER_LIKES_PRAGMA_MARK
	253	#pragma mark -
8e92c31c A	254	#pragma mark - Packet Sending Functions
	255	#endif
	256
67c8f8a1	257	extern mStatus mDNSSendDNSMessage(mDNS const m, DNSMessage const msg, mDNSu8 *end,
9f29194f	258	mDNSInterfaceID InterfaceID, UDPSocket src, const mDNSAddr dst, mDNSIPPort dstport, TCPSocket sock, DomainAuthInfo authInfo);
7f0064bd A	259
	260	// ***************************************************************************
	261	#if COMPILER_LIKES_PRAGMA_MARK
	262	#pragma mark -
	263	#pragma mark - RR List Management & Task Management
	264	#endif
	265
32bb7e43	266	extern void ShowTaskSchedulingError(mDNS *const m);
263eeeab A	267	extern void mDNS_Lock_(mDNS const m, const char const functionname);
263eeeab A	268	extern void mDNS_Unlock_(mDNS const m, const char const functionname);
67c8f8a1	269
32bb7e43 A	270	#if defined(_WIN32)
	271	#define __func__ __FUNCTION__
	272	#endif
	273
263eeeab	274	#define mDNS_Lock(X) mDNS_Lock_((X), __func__)
67c8f8a1	275
263eeeab	276	#define mDNS_Unlock(X) mDNS_Unlock_((X), __func__)
67c8f8a1 A	277
	278	#define mDNS_DropLockBeforeCallback() do { m->mDNS_reentrancy++; \
	279	if (m->mDNS_busy != m->mDNS_reentrancy) LogMsg("%s: Locking Failure! mDNS_busy (%ld) != mDNS_reentrancy (%ld)", __func__, m->mDNS_busy, m->mDNS_reentrancy); \
	280	} while (0)
	281
	282	#define mDNS_ReclaimLockAfterCallback() do { \
	283	if (m->mDNS_busy != m->mDNS_reentrancy) LogMsg("%s: Unlocking Failure! mDNS_busy (%ld) != mDNS_reentrancy (%ld)", __func__, m->mDNS_busy, m->mDNS_reentrancy); \
	284	m->mDNS_reentrancy--; } while (0)
283ee3ff	285
8e92c31c A	286	#ifdef __cplusplus
	287	}
	288	#endif
	289
	290	#endif // __DNSCOMMON_H_