/* -*- Mode: C; tab-width: 4 -*-
*
- * Copyright (c) 2002-2003 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2002-2006 Apple Computer, Inc. All rights reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
Change History (most recent first):
$Log: mDNS.c,v $
+Revision 1.535.2.3 2006/11/10 19:36:42 cheshire
+Further refinement: Only harmonize TTL if the value we're adjusting it to is at least 2 seconds
+
+Revision 1.535.2.2 2006/10/31 02:11:26 cheshire
+Compile error: Need to put back AllDNSLinkGroupv4 definition
+
+Revision 1.535.2.1 2006/10/31 01:28:06 cheshire
+<rdar://problem/4456945> After service restarts on different port, for a few seconds DNS-SD may return stale port number
+
+Revision 1.535 2006/03/02 20:41:17 cheshire
+<rdar://problem/4111464> After record update, old record sometimes remains in cache
+Minor code tidying and comments to reduce the risk of similar programming errors in future
+
+Revision 1.534 2006/03/02 03:25:46 cheshire
+<rdar://problem/4111464> After record update, old record sometimes remains in cache
+Code to harmonize RRSet TTLs was inadvertently rescuing expiring records
+
+Revision 1.533 2006/02/26 00:54:41 cheshire
+Fixes to avoid code generation warning/error on FreeBSD 7
+
+Revision 1.532 2005/12/02 20:24:36 cheshire
+<rdar://problem/4363209> Adjust cutoff time for KA list by one second
+
+Revision 1.531 2005/12/02 19:05:42 cheshire
+Tidy up constants
+
+Revision 1.530 2005/11/07 01:49:48 cheshire
+For consistency, use NonZeroTime() function instead of ?: expression
+
+Revision 1.529 2005/10/25 23:42:24 cheshire
+<rdar://problem/4316057> Error in ResolveSimultaneousProbe() when type or class don't match
+Changed switch statement to an "if"
+
+Revision 1.528 2005/10/25 23:34:22 cheshire
+<rdar://problem/4316048> RequireGoodbye state not set/respected sometimes when machine going to sleep
+
+Revision 1.527 2005/10/25 22:43:59 cheshire
+Add clarifying comments
+
Revision 1.526 2005/10/20 00:10:33 cheshire
<rdar://problem/4290265> Add check to avoid crashing NAT gateways that have buggy DNS relay code
<rdar://problem/3739115>: TXT Record updates not available for wide-area services
Revision 1.387 2004/07/26 22:49:30 ksekar
-<rdar://problem/3651409>: Feature #9516: Need support for NATPMP in client
+<rdar://problem/3651409>: Feature #9516: Need support for NAT-PMP in client
Revision 1.386 2004/07/13 21:24:24 rpantos
Fix for <rdar://problem/3701120>.
mDNSlocal const mDNSInterfaceID mDNSInterfaceMark = (mDNSInterfaceID)~0;
-#define UnicastDNSPortAsNumber 53
+#define UnicastDNSPortAsNumber 53
+#define NATPMPPortAsNumber 5351
+#define DNSEXTPortAsNumber 5352 // Port used for end-to-end DNS operations like LLQ, Updates with Leases, etc.
#define MulticastDNSPortAsNumber 5353
+#define LoopbackIPCPortAsNumber 5354
+
mDNSexport const mDNSIPPort UnicastDNSPort = { { UnicastDNSPortAsNumber >> 8, UnicastDNSPortAsNumber & 0xFF } };
+mDNSexport const mDNSIPPort NATPMPPort = { { NATPMPPortAsNumber >> 8, NATPMPPortAsNumber & 0xFF } };
+mDNSexport const mDNSIPPort DNSEXTPort = { { DNSEXTPortAsNumber >> 8, DNSEXTPortAsNumber & 0xFF } };
mDNSexport const mDNSIPPort MulticastDNSPort = { { MulticastDNSPortAsNumber >> 8, MulticastDNSPortAsNumber & 0xFF } };
+mDNSexport const mDNSIPPort LoopbackIPCPort = { { LoopbackIPCPortAsNumber >> 8, LoopbackIPCPortAsNumber & 0xFF } };
+
mDNSexport const mDNSv4Addr AllDNSAdminGroup = { { 239, 255, 255, 251 } };
mDNSexport const mDNSv4Addr AllDNSLinkGroupv4 = { { 224, 0, 0, 251 } };
mDNSexport const mDNSv6Addr AllDNSLinkGroupv6 = { { 0xFF,0x02,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0xFB } };
mDNSexport const mDNSAddr AllDNSLinkGroup_v4 = { mDNSAddrType_IPv4, { { { 224, 0, 0, 251 } } } };
mDNSexport const mDNSAddr AllDNSLinkGroup_v6 = { mDNSAddrType_IPv6, { { { 0xFF,0x02,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0xFB } } } };
-mDNSexport const mDNSOpaque16 zeroID = { { 0, 0 } };
-mDNSexport const mDNSOpaque16 QueryFlags = { { kDNSFlag0_QR_Query | kDNSFlag0_OP_StdQuery, 0 } };
-mDNSexport const mDNSOpaque16 uQueryFlags = { { kDNSFlag0_QR_Query | kDNSFlag0_OP_StdQuery | kDNSFlag0_RD, 0 } };
-mDNSexport const mDNSOpaque16 ResponseFlags = { { kDNSFlag0_QR_Response | kDNSFlag0_OP_StdQuery | kDNSFlag0_AA, 0 } };
-mDNSexport const mDNSOpaque16 UpdateReqFlags= { { kDNSFlag0_QR_Query | kDNSFlag0_OP_Update, 0 } };
-mDNSexport const mDNSOpaque16 UpdateRespFlags={ { kDNSFlag0_QR_Response | kDNSFlag0_OP_Update, 0 } };
+mDNSexport const mDNSOpaque16 zeroID = { { 0, 0 } };
+mDNSexport const mDNSOpaque16 QueryFlags = { { kDNSFlag0_QR_Query | kDNSFlag0_OP_StdQuery, 0 } };
+mDNSexport const mDNSOpaque16 uQueryFlags = { { kDNSFlag0_QR_Query | kDNSFlag0_OP_StdQuery | kDNSFlag0_RD, 0 } };
+mDNSexport const mDNSOpaque16 ResponseFlags = { { kDNSFlag0_QR_Response | kDNSFlag0_OP_StdQuery | kDNSFlag0_AA, 0 } };
+mDNSexport const mDNSOpaque16 UpdateReqFlags = { { kDNSFlag0_QR_Query | kDNSFlag0_OP_Update, 0 } };
+mDNSexport const mDNSOpaque16 UpdateRespFlags = { { kDNSFlag0_QR_Response | kDNSFlag0_OP_Update, 0 } };
// Any records bigger than this are considered 'large' records
#define SmallRecordLimit 1024
numDereg++;
responseptr = newptr;
}
- else if (rr->NewRData) // If we have new data for this record
+ else if (rr->NewRData && !m->SleepState) // If we have new data for this record
{
RData *OldRData = rr->resrec.rdata;
mDNSu16 oldrdlength = rr->resrec.rdlength;
if (!newptr && m->omsg.h.numAnswers) break;
numDereg++;
responseptr = newptr;
+ rr->RequireGoodbye = mDNSfalse;
}
// Now try to see if we can fit the update in the same packet (not fatal if we can't)
SetNewRData(&rr->resrec, rr->NewRData, rr->newrdlength);
rr->resrec.rrclass |= kDNSClass_UniqueRRSet; // Temporarily set the cache flush bit so PutResourceRecord will set it
newptr = PutResourceRecord(&m->omsg, responseptr, &m->omsg.h.numAnswers, &rr->resrec);
rr->resrec.rrclass &= ~kDNSClass_UniqueRRSet; // Make sure to clear cache flush bit back to normal state
- if (newptr) responseptr = newptr;
+ if (newptr) { responseptr = newptr; rr->RequireGoodbye = mDNStrue; }
SetNewRData(&rr->resrec, OldRData, oldrdlength);
}
else
// Note: MUST call SetNextCacheCheckTime any time we change:
// rr->TimeRcvd
-// rr->DelayDelivery
// rr->resrec.rroriginalttl
// rr->UnansweredQueries
// rr->CRActiveQuestion
+// Also, any time we set rr->DelayDelivery we should call SetNextCacheCheckTime to ensure m->NextCacheCheck is set if necessary
+// Clearing rr->DelayDelivery does not require a call to SetNextCacheCheckTime
mDNSlocal void SetNextCacheCheckTime(mDNS *const m, CacheRecord *const rr)
{
rr->NextRequiredQuery = RRExpireTime(rr);
rr->NextInKAList == mDNSNULL && ka != &rr->NextInKAList && // which is not already in the known answer list
rr->resrec.rdlength <= SmallRecordLimit && // which is small enough to sensibly fit in the packet
ResourceRecordAnswersQuestion(&rr->resrec, q) && // which answers our question
- rr->TimeRcvd + TicksTTL(rr)/2 - m->timenow >= 0) // and it is less than half-way to expiry
+ rr->TimeRcvd + TicksTTL(rr)/2 - m->timenow > // and its half-way-to-expiry time is at least 1 second away
+ mDNSPlatformOneSecond) // (also ensures we never include goodbye records with TTL=1)
{
*ka = rr; // Link this record into our known answer chain
ka = &rr->NextInKAList;
mDNSlocal void CacheRecordDeferredAdd(mDNS *const m, CacheRecord *rr)
{
- rr->DelayDelivery = 0;
+ rr->DelayDelivery = 0; // Note, only need to call SetNextCacheCheckTime() when DelayDelivery is set, not when it's cleared
if (m->CurrentQuestion) LogMsg("CacheRecordDeferredAdd ERROR m->CurrentQuestion already set");
m->CurrentQuestion = m->Questions;
while (m->CurrentQuestion && m->CurrentQuestion != m->NewQuestions)
if (threshhold - 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);
- if (delay - start > 0) return(delay ? delay : 1); // Make sure we return non-zero if we want to delay
+ if (delay - start > 0) return(NonZeroTime(delay));
else return(0);
}
}
}
m->CurrentQuestion = mDNSNULL;
+ SetNextCacheCheckTime(m, rr);
}
// NoCacheAnswer is only called from mDNSCoreReceiveResponse, *never* directly as a result of a client API call.
mDNSlocal void NoCacheAnswer(mDNS *const m, CacheRecord *rr)
{
LogMsg("No cache space: Delivering non-cached result for %##s", m->rec.r.resrec.name->c);
- if (m->CurrentQuestion) LogMsg("CacheRecordAdd ERROR m->CurrentQuestion already set");
+ if (m->CurrentQuestion) LogMsg("NoCacheAnswer ERROR m->CurrentQuestion already set");
m->CurrentQuestion = m->Questions;
while (m->CurrentQuestion)
{
m->CurrentQuestion = q->next;
if (ResourceRecordAnswersQuestion(&rr->resrec, q))
{
- verbosedebugf("CacheRecordRmv %p %##s (%s)", rr, rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype));
+ verbosedebugf("CacheRecordRmv %p %s", rr, CRDisplayString(m, rr));
if (q->CurrentAnswers == 0)
LogMsg("CacheRecordRmv ERROR: How can CurrentAnswers already be zero for %p %##s (%s)?", q, q->qname.c, DNSTypeName(q->qtype));
else
if (*pktptr > *ourptr) return(-1); // Our data is numerically lower; We lost
if (*pktptr < *ourptr) return(+1); // Packet data is numerically lower; We won
- debugf("CompareRData: How did we get here?");
+ LogMsg("CompareRData ERROR: Invalid state");
return(-1);
}
int result = (int)our->resrec.rrclass - (int)m->rec.r.resrec.rrclass;
if (!result) result = (int)our->resrec.rrtype - (int)m->rec.r.resrec.rrtype;
if (!result) result = CompareRData(our, &m->rec.r);
- switch (result)
+ if (result > 0)
+ debugf("ResolveSimultaneousProbe: %##s (%s): We won", our->resrec.name->c, DNSTypeName(our->resrec.rrtype));
+ else if (result < 0)
{
- case 1: debugf("ResolveSimultaneousProbe: %##s (%s): We won", our->resrec.name->c, DNSTypeName(our->resrec.rrtype));
- break;
- case 0: break;
- case -1: debugf("ResolveSimultaneousProbe: %##s (%s): We lost", our->resrec.name->c, DNSTypeName(our->resrec.rrtype));
- mDNS_Deregister_internal(m, our, mDNS_Dereg_conflict);
- goto exit;
+ debugf("ResolveSimultaneousProbe: %##s (%s): We lost", our->resrec.name->c, DNSTypeName(our->resrec.rrtype));
+ mDNS_Deregister_internal(m, our, mDNS_Dereg_conflict);
+ goto exit;
}
}
}
const mDNSInterfaceID InterfaceID)
{
int i;
- const mDNSu8 *ptr = LocateAnswers(response, end); // We ignore questions (if any) in a DNS response packet
- CacheRecord *CacheFlushRecords = (CacheRecord*)1; // "(CacheRecord*)1" is special (non-zero) end-of-list marker
+
+ // We ignore questions (if any) in a DNS response packet
+ const mDNSu8 *ptr = LocateAnswers(response, end);
+
+ // "(CacheRecord*)1" is a special (non-zero) end-of-list marker
+ // We use this non-zero marker so that records in our CacheFlushRecords list will always have NextInCFList
+ // set non-zero, and that tells GetCacheEntity() that they're not, at this moment, eligible for recycling.
+ CacheRecord *CacheFlushRecords = (CacheRecord*)1;
CacheRecord **cfp = &CacheFlushRecords;
// All records in a DNS response packet are treated as equally valid statements of truth. If we want
rr->DelayDelivery = m->timenow + mDNSPlatformOneSecond; // to delay delivery of this 'add' event
else
rr->DelayDelivery = CheckForSoonToExpireRecords(m, rr->resrec.name, rr->resrec.namehash, slot);
- CacheRecordAdd(m, rr);
- // MUST do this AFTER CacheRecordAdd(), because that's what sets CRActiveQuestion for us
- SetNextCacheCheckTime(m, rr);
+ CacheRecordAdd(m, rr); // CacheRecordAdd calls SetNextCacheCheckTime(m, rr); for us
}
}
}
r1->NextInCFList = mDNSNULL;
for (r2 = cg ? cg->members : mDNSNULL; r2; r2=r2->next)
if (SameResourceRecordSignature(&r1->resrec, &r2->resrec))
- {
- // If record is recent, just ensure the whole RRSet has the same TTL (as required by DNS semantics)
- // else, if record is old, mark it to be flushed
- if (m->timenow - r2->TimeRcvd < mDNSPlatformOneSecond)
- r2->resrec.rroriginalttl = r1->resrec.rroriginalttl;
- else
+ if (RRExpireTime(r2) - m->timenow > mDNSPlatformOneSecond)
{
- verbosedebugf("Cache flush %p X %p %##s (%s)", r1, r2, r2->resrec.name->c, DNSTypeName(r2->resrec.rrtype));
- // We set stale records to expire in one second.
- // This gives the owner a chance to rescue it if necessary.
- // This is important in the case of multi-homing and bridged networks:
- // Suppose host X is on Ethernet. X then connects to an AirPort base station, which happens to be
- // bridged onto the same Ethernet. When X announces its AirPort IP address with the cache-flush bit
- // set, the AirPort packet will be bridged onto the Ethernet, and all other hosts on the Ethernet
- // will promptly delete their cached copies of the (still valid) Ethernet IP address record.
- // By delaying the deletion by one second, we give X a change to notice that this bridging has
- // happened, and re-announce its Ethernet IP address to rescue it from deletion from all our caches.
- // We set UnansweredQueries to MaxUnansweredQueries to avoid expensive and unnecessary
- // final expiration queries for this record.
- r2->resrec.rroriginalttl = 1;
- r2->TimeRcvd = m->timenow;
- r2->UnansweredQueries = MaxUnansweredQueries;
+ // If record is recent, just ensure the whole RRSet has the same TTL (as required by DNS semantics)
+ // else, if record is old, mark it to be flushed
+ if (m->timenow - r2->TimeRcvd < mDNSPlatformOneSecond)
+ {
+ if (r2->resrec.rroriginalttl != r1->resrec.rroriginalttl && r1->resrec.rroriginalttl > 1)
+ r2->resrec.rroriginalttl = r1->resrec.rroriginalttl;
+ }
+ else // else, if record is old, mark it to be flushed
+ {
+ verbosedebugf("Cache flush %p X %p %s", r1, r2, CRDisplayString(m, r2));
+ // We set stale records to expire in one second.
+ // This gives the owner a chance to rescue it if necessary.
+ // This is important in the case of multi-homing and bridged networks:
+ // Suppose host X is on Ethernet. X then connects to an AirPort base station, which happens to be
+ // bridged onto the same Ethernet. When X announces its AirPort IP address with the cache-flush bit
+ // set, the AirPort packet will be bridged onto the Ethernet, and all other hosts on the Ethernet
+ // will promptly delete their cached copies of the (still valid) Ethernet IP address record.
+ // By delaying the deletion by one second, we give X a change to notice that this bridging has
+ // happened, and re-announce its Ethernet IP address to rescue it from deletion from all our caches.
+ // We set UnansweredQueries to MaxUnansweredQueries to avoid expensive and unnecessary
+ // final expiration queries for this record.
+ r2->resrec.rroriginalttl = 1;
+ r2->UnansweredQueries = MaxUnansweredQueries;
+ }
+ r2->TimeRcvd = m->timenow;
SetNextCacheCheckTime(m, r2);
}
- }
if (r1->DelayDelivery) // If we were planning to delay delivery of this record, see if we still need to
{
+ // Note, only need to call SetNextCacheCheckTime() when DelayDelivery is set, not when it's cleared
r1->DelayDelivery = CheckForSoonToExpireRecords(m, r1->resrec.name, r1->resrec.namehash, slot);
if (!r1->DelayDelivery) CacheRecordDeferredAdd(m, r1);
}
const mDNSu8 UpdateR = kDNSFlag0_QR_Response | kDNSFlag0_OP_Update;
#ifndef UNICAST_DISABLED
- mDNSIPPort NATPort = mDNSOpaque16fromIntVal(NATMAP_PORT);
-
- if (srcport.NotAnInteger == NATPort.NotAnInteger)
+ if (srcport.NotAnInteger == NATPMPPort.NotAnInteger)
{
mDNS_Lock(m);
uDNS_ReceiveNATMap(m, pkt, (mDNSu16)(end - (mDNSu8 *)pkt));
projects / apple / mdnsresponder.git / blobdiff