| /* -*- 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 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); |
| |
| #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 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 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_ |