diff options
Diffstat (limited to 'mDNSResponder/mDNSCore/mDNS.c')
| -rwxr-xr-x | mDNSResponder/mDNSCore/mDNS.c | 133 |
1 files changed, 56 insertions, 77 deletions
diff --git a/mDNSResponder/mDNSCore/mDNS.c b/mDNSResponder/mDNSCore/mDNS.c index 72375d94..0788ab67 100755 --- a/mDNSResponder/mDNSCore/mDNS.c +++ b/mDNSResponder/mDNSCore/mDNS.c @@ -83,7 +83,7 @@ mDNSlocal void BeginSleepProcessing(mDNS *const m); mDNSlocal void RetrySPSRegistrations(mDNS *const m); mDNSlocal void SendWakeup(mDNS *const m, mDNSInterfaceID InterfaceID, mDNSEthAddr *EthAddr, mDNSOpaque48 *password, mDNSBool unicastOnly); mDNSlocal mDNSBool LocalRecordRmvEventsForQuestion(mDNS *const m, DNSQuestion *q); -mDNSlocal void mDNS_PurgeForQuestion(mDNS *const m, DNSQuestion *q); +mDNSlocal void mDNS_PurgeBeforeResolve(mDNS *const m, DNSQuestion *q); mDNSlocal void CheckForDNSSECRecords(mDNS *const m, DNSQuestion *q); mDNSlocal void mDNS_SendKeepalives(mDNS *const m); mDNSlocal void mDNS_ExtractKeepaliveInfo(AuthRecord *ar, mDNSu32 *timeout, mDNSAddr *laddr, mDNSAddr *raddr, mDNSEthAddr *eth, @@ -4321,56 +4321,17 @@ mDNSlocal void CacheRecordDeferredAdd(mDNS *const m, CacheRecord *rr) m->CurrentQuestion = mDNSNULL; } -mDNSlocal mDNSs32 CheckForSoonToExpireRecords(mDNS *const m, const domainname *const name, const mDNSu32 namehash, mDNSBool *purge) +mDNSlocal mDNSs32 CheckForSoonToExpireRecords(mDNS *const m, const domainname *const name, const mDNSu32 namehash) { - const mDNSs32 threshhold = m->timenow + mDNSPlatformOneSecond; // See if there are any records expiring within one second + const mDNSs32 threshold = m->timenow + mDNSPlatformOneSecond; // See if there are any records expiring within one second const mDNSs32 start = m->timenow - 0x10000000; mDNSs32 delay = start; CacheGroup *cg = CacheGroupForName(m, namehash, name); const CacheRecord *rr; - if (purge) - *purge = mDNSfalse; for (rr = cg ? cg->members : mDNSNULL; rr; rr=rr->next) { - // If there are records that will expire soon, there are cases that need delayed - // delivery of events: - // - // 1) A new cache entry is about to be added as a replacement. The caller needs to - // deliver a RMV (for the current old entry) followed by ADD (for the new entry). - // It needs to schedule the timer for the next cache expiry (ScheduleNextCacheCheckTime), - // so that the cache entry can be purged (purging causes the RMV followed by ADD) - // - // 2) A new question is about to be answered and the caller needs to know whether it's - // scheduling should be delayed so that the question is not answered with this record. - // Instead of delivering an ADD (old entry) followed by RMV (old entry) and another ADD - // (new entry), a single ADD can be delivered by delaying the scheduling of the question - // immediately. - // - // When the unicast cache record is created, it's TTL has been extended beyond its value - // given in the resource record (See RRAdjustTTL). If it is in the "extended" time, the - // cache is already expired and we set "purge" to indicate that. When "purge" is set, the - // return value of the function should be ignored by the callers. - // - // Note: For case (1), "purge" argument is NULL and hence the following checks are skipped. - // It is okay to skip in that case because the cache records have been set to expire almost - // immediately and the extended time does not apply. - // - // Also, if there is already an active question we don't try to optimize as purging the cache - // would end up delivering RMV for the active question and hence we avoid that. - - if (purge && !rr->resrec.InterfaceID && !rr->CRActiveQuestion && rr->resrec.rroriginalttl) - { - mDNSu32 uTTL = RRUnadjustedTTL(rr->resrec.rroriginalttl); - if (m->timenow - (rr->TimeRcvd + ((mDNSs32)uTTL * mDNSPlatformOneSecond)) >= 0) - { - LogInfo("CheckForSoonToExpireRecords: %s: rroriginalttl %u, unadjustedTTL %u, currentTTL %u", - CRDisplayString(m, rr), rr->resrec.rroriginalttl, uTTL, (m->timenow - rr->TimeRcvd)/mDNSPlatformOneSecond); - *purge = mDNStrue; - continue; - } - } - if (threshhold - RRExpireTime(rr) >= 0) // If we have records about to expire within a second + if (threshold - RRExpireTime(rr) >= 0) // If we have records about to expire within a second { if (delay - RRExpireTime(rr) < 0) // then delay until after they've been deleted delay = RRExpireTime(rr); @@ -6827,7 +6788,13 @@ mDNSexport void mDNSCoreMachineSleep(mDNS *const m, mDNSBool sleep) #endif mDNS_ReclaimLockAfterCallback(); } - +#ifdef _LEGACY_NAT_TRAVERSAL_ + if (m->SSDPSocket) + { + mDNSPlatformUDPClose(m->SSDPSocket); + m->SSDPSocket = mDNSNULL; + } +#endif m->SleepState = SleepState_Transferring; if (m->SystemWakeOnLANEnabled && m->DelaySleep) { @@ -8963,18 +8930,25 @@ mDNSlocal void mDNSCoreReceiveResponse(mDNS *const m, // abort our TCP connection, and not complete the operation, and end up with an incomplete RRSet in our cache. // Next time there's a query for this RRSet we'll see answers in our cache, and assume we have the whole RRSet already, // and not even do the TCP query. - // Accordingly, if we get a uDNS reply with kDNSFlag0_TC set, we bail out and wait for the TCP response containing the entire RRSet. - if (!InterfaceID && (response->h.flags.b[0] & kDNSFlag0_TC)) return; + // Accordingly, if we get a uDNS reply with kDNSFlag0_TC set, we bail out and wait for the TCP response containing the + // entire RRSet, with the following exception. If the response contains an answer section and one or more records in + // either the authority section or additional section, then that implies that truncation occurred beyond the answer + // section, and the answer section is therefore assumed to be complete. + // + // From section 6.2 of RFC 1035 <https://tools.ietf.org/html/rfc1035>: + // When a response is so long that truncation is required, the truncation + // should start at the end of the response and work forward in the + // datagram. Thus if there is any data for the authority section, the + // answer section is guaranteed to be unique. + if (!InterfaceID && (response->h.flags.b[0] & kDNSFlag0_TC) && + ((response->h.numAnswers == 0) || ((response->h.numAuthorities == 0) && (response->h.numAdditionals == 0)))) return; if (LLQType == uDNS_LLQ_Ignore) return; // 1. We ignore questions (if any) in mDNS response packets // 2. If this is an LLQ response, we handle it much the same - // 3. If we get a uDNS UDP response with the TC (truncated) bit set, then we can't treat this - // answer as being the authoritative complete RRSet, and respond by deleting all other - // matching cache records that don't appear in this packet. // Otherwise, this is a authoritative uDNS answer, so arrange for any stale records to be purged - if (ResponseMCast || LLQType == uDNS_LLQ_Events || (response->h.flags.b[0] & kDNSFlag0_TC)) + if (ResponseMCast || LLQType == uDNS_LLQ_Events) ptr = LocateAnswers(response, end); // Otherwise, for one-shot queries, any answers in our cache that are not also contained // in this response packet are immediately deemed to be invalid. @@ -9420,7 +9394,7 @@ mDNSlocal void mDNSCoreReceiveResponse(mDNS *const m, if (AddToCFList) delay = NonZeroTime(m->timenow + mDNSPlatformOneSecond); else - delay = CheckForSoonToExpireRecords(m, m->rec.r.resrec.name, m->rec.r.resrec.namehash, mDNSNULL); + delay = CheckForSoonToExpireRecords(m, m->rec.r.resrec.name, m->rec.r.resrec.namehash); // If unique, assume we may have to delay delivery of this 'add' event. // Below, where we walk the CacheFlushRecords list, we either call CacheRecordDeferredAdd() @@ -9488,6 +9462,7 @@ exit: CacheRecord *r1 = CacheFlushRecords, *r2; const mDNSu32 slot = HashSlotFromNameHash(r1->resrec.namehash); const CacheGroup *cg = CacheGroupForRecord(m, &r1->resrec); + mDNSBool purgedRecords = mDNSfalse; CacheFlushRecords = CacheFlushRecords->NextInCFList; r1->NextInCFList = mDNSNULL; @@ -9569,8 +9544,9 @@ exit: r2->resrec.rroriginalttl = r1->resrec.rroriginalttl; } r2->TimeRcvd = m->timenow; + SetNextCacheCheckTimeForRecord(m, r2); } - else // else, if record is old, mark it to be flushed + else if (r2->resrec.InterfaceID) // else, if record is old, mark it to be flushed { verbosedebugf("Cache flush new %p age %d expire in %d %s", r1, m->timenow - r1->TimeRcvd, RRExpireTime(r1) - m->timenow, CRDisplayString(m, r1)); verbosedebugf("Cache flush old %p age %d expire in %d %s", r2, m->timenow - r2->TimeRcvd, RRExpireTime(r2) - m->timenow, CRDisplayString(m, r2)); @@ -9608,8 +9584,14 @@ exit: // We use (m->timenow - 1) instead of m->timenow, because we use that to identify records // that we marked for deletion via an explicit DE record } + SetNextCacheCheckTimeForRecord(m, r2); + } + else + { + // Old uDNS records are scheduled to be purged instead of given at most one second to live. + mDNS_PurgeCacheResourceRecord(m, r2); + purgedRecords = mDNStrue; } - SetNextCacheCheckTimeForRecord(m, r2); } } @@ -9637,7 +9619,16 @@ exit: NSECRecords = mDNSNULL; NSECCachePtr = mDNSNULL; } - r1->DelayDelivery = CheckForSoonToExpireRecords(m, r1->resrec.name, r1->resrec.namehash, mDNSNULL); + if (r1->resrec.InterfaceID) + { + r1->DelayDelivery = CheckForSoonToExpireRecords(m, r1->resrec.name, r1->resrec.namehash); + } + else + { + // If uDNS records from an older RRset were scheduled to be purged, then delay delivery slightly to allow + // them to be deleted before any ADD events for this record. + r1->DelayDelivery = purgedRecords ? NonZeroTime(m->timenow) : 0; + } // If no longer delaying, deliver answer now, else schedule delivery for the appropriate time if (!r1->DelayDelivery) CacheRecordDeferredAdd(m, r1); else ScheduleNextCacheCheckTime(m, slot, r1->DelayDelivery); @@ -11650,7 +11641,7 @@ mDNSlocal mStatus ValidateParameters(mDNS *const m, DNSQuestion *const question) } // InitDNSConfig() is called by InitCommonState() to initialize the DNS configuration of the Question. -// These are a subset of the internal uDNS fields. Must be done before ShouldSuppressQuery() & mDNS_PurgeForQuestion() +// These are a subset of the internal uDNS fields. Must be done before ShouldSuppressQuery() & mDNS_PurgeBeforeResolve() mDNSlocal void InitDNSConfig(mDNS *const m, DNSQuestion *const question) { // First reset all DNS Configuration @@ -11706,9 +11697,8 @@ mDNSlocal void InitDNSConfig(mDNS *const m, DNSQuestion *const question) // InitCommonState() is called by mDNS_StartQuery_internal() to initialize the common(uDNS/mDNS) internal // state fields of the DNS Question. These are independent of the Client layer. -mDNSlocal mDNSBool InitCommonState(mDNS *const m, DNSQuestion *const question) +mDNSlocal void InitCommonState(mDNS *const m, DNSQuestion *const question) { - mDNSBool purge; int i; mDNSBool isBlocked = mDNSfalse; @@ -11727,7 +11717,7 @@ mDNSlocal mDNSBool InitCommonState(mDNS *const m, DNSQuestion *const question) // turned ON which can allocate memory e.g., base64 encoding, in the case of DNSSEC. question->ThisQInterval = InitialQuestionInterval; // MUST be > zero for an active question question->qnamehash = DomainNameHashValue(&question->qname); - question->DelayAnswering = CheckForSoonToExpireRecords(m, &question->qname, question->qnamehash, &purge); + question->DelayAnswering = mDNSOpaque16IsZero(question->TargetQID) ? CheckForSoonToExpireRecords(m, &question->qname, question->qnamehash) : 0; question->LastQTime = m->timenow; question->ExpectUnicastResp = 0; question->LastAnswerPktNum = m->PktNum; @@ -11809,7 +11799,6 @@ mDNSlocal mDNSBool InitCommonState(mDNS *const m, DNSQuestion *const question) if (question->WakeOnResolve) { question->WakeOnResolveCount = InitialWakeOnResolveCount; - purge = mDNStrue; } for (i=0; i<DupSuppressInfoSize; i++) @@ -11826,8 +11815,6 @@ mDNSlocal mDNSBool InitCommonState(mDNS *const m, DNSQuestion *const question) if (question->DelayAnswering) LogInfo("InitCommonState: Delaying answering for %d ticks while cache stabilizes for %##s (%s)", question->DelayAnswering - m->timenow, question->qname.c, DNSTypeName(question->qtype)); - - return(purge); } // Excludes the DNS Config fields which are already handled by InitDNSConfig() @@ -11909,7 +11896,7 @@ mDNSlocal void InitDNSSECProxyState(mDNS *const m, DNSQuestion *const question) // Once the question is completely initialized including the duplicate logic, this function // is called to finalize the unicast question which requires flushing the cache if needed, // activating the query etc. -mDNSlocal void FinalizeUnicastQuestion(mDNS *const m, DNSQuestion *question, mDNSBool purge) +mDNSlocal void FinalizeUnicastQuestion(mDNS *const m, DNSQuestion *question) { // Ensure DNS related info of duplicate question is same as the orig question if (question->DuplicateOf) @@ -11934,14 +11921,7 @@ mDNSlocal void FinalizeUnicastQuestion(mDNS *const m, DNSQuestion *question, mDN ActivateUnicastQuery(m, question, mDNSfalse); - // If purge was set above, flush the cache. Need to do this after we set the - // DNS server on the question - if (purge) - { - question->DelayAnswering = 0; - mDNS_PurgeForQuestion(m, question); - } - else if (!question->DuplicateOf && DNSSECQuestion(question)) + if (!question->DuplicateOf && DNSSECQuestion(question)) { // For DNSSEC questions, we need to have the RRSIGs also for verification. CheckForDNSSECRecords(m, question); @@ -11964,7 +11944,6 @@ mDNSexport mStatus mDNS_StartQuery_internal(mDNS *const m, DNSQuestion *const qu { DNSQuestion **q; mStatus vStatus; - mDNSBool purge; // First check for cache space (can't do queries if there is no cache space allocated) if (m->rrcache_size == 0) @@ -12012,7 +11991,7 @@ mDNSexport mStatus mDNS_StartQuery_internal(mDNS *const m, DNSQuestion *const qu // InitCommonState -> InitDNSConfig) as DNS server selection affects DNSSEC // validation. - purge = InitCommonState(m, question); + InitCommonState(m, question); InitWABState(question); InitLLQState(question); #ifdef DNS_PUSH_ENABLED @@ -12045,7 +12024,7 @@ mDNSexport mStatus mDNS_StartQuery_internal(mDNS *const m, DNSQuestion *const qu // this routine with the question list data structures in an inconsistent state. if (!mDNSOpaque16IsZero(question->TargetQID)) { - FinalizeUnicastQuestion(m, question, purge); + FinalizeUnicastQuestion(m, question); } else { @@ -12065,10 +12044,10 @@ mDNSexport mStatus mDNS_StartQuery_internal(mDNS *const m, DNSQuestion *const qu } } #endif // BONJOUR_ON_DEMAND - if (purge) + if (question->WakeOnResolve) { LogInfo("mDNS_StartQuery_internal: Purging for %##s", question->qname.c); - mDNS_PurgeForQuestion(m, question); + mDNS_PurgeBeforeResolve(m, question); } } } @@ -14618,7 +14597,7 @@ mDNSlocal void PurgeOrReconfirmCacheRecord(mDNS *const m, CacheRecord *cr, const } } -mDNSlocal void mDNS_PurgeForQuestion(mDNS *const m, DNSQuestion *q) +mDNSlocal void mDNS_PurgeBeforeResolve(mDNS *const m, DNSQuestion *q) { CacheGroup *const cg = CacheGroupForName(m, q->qnamehash, &q->qname); CacheRecord *rp; @@ -14634,7 +14613,7 @@ mDNSlocal void mDNS_PurgeForQuestion(mDNS *const m, DNSQuestion *q) { if (SameNameRecordAnswersQuestion(&rp->resrec, q)) { - LogInfo("mDNS_PurgeForQuestion: Flushing %s", CRDisplayString(m, rp)); + LogInfo("mDNS_PurgeBeforeResolve: Flushing %s", CRDisplayString(m, rp)); mDNS_PurgeCacheResourceRecord(m, rp); } } |