mDNSResponder: Update to v567

The sources can be obtained via:

https://opensource.apple.com/tarballs/mDNSResponder/mDNSResponder-567.tar.gz

Update #3522.

4 files changed, 24 insertions, 6 deletions

diff --git a/mDNSResponder/mDNSCore/DNSCommon.c b/mDNSResponder/mDNSCore/DNSCommon.c
index 947607cf..3b2f2ceb 100644
--- a/mDNSResponder/mDNSCore/DNSCommon.c
+++ b/mDNSResponder/mDNSCore/DNSCommon.c
@@ -370,7 +370,7 @@ mDNSexport char *GetRRDisplayString_rdb(const ResourceRecord *const rr, const RD
     char *ptr = buffer;
     mDNSu32 length = mDNS_snprintf(buffer, MaxMsg-1, "%4d %##s %s ", rr->rdlength, rr->name->c, DNSTypeName(rr->rrtype));
     if (rr->RecordType == kDNSRecordTypePacketNegative) return(buffer);
-    if (!rr->rdlength) { mDNS_snprintf(buffer+length, RemSpc, "<< ZERO RDATA LENGTH >>"); return(buffer); }
+    if (!rr->rdlength && rr->rrtype != kDNSType_OPT) { mDNS_snprintf(buffer+length, RemSpc, "<< ZERO RDATA LENGTH >>"); return(buffer); }
 
     switch (rr->rrtype)
     {
@@ -408,6 +408,7 @@ mDNSexport char *GetRRDisplayString_rdb(const ResourceRecord *const rr, const RD
             switch(opt->opt)
             {
             case kDNSOpt_LLQ:
+                length += mDNS_snprintf(buffer+length, RemSpc, " LLQ");
                 length += mDNS_snprintf(buffer+length, RemSpc, " Vers %d",     opt->u.llq.vers);
                 length += mDNS_snprintf(buffer+length, RemSpc, " Op %d",       opt->u.llq.llqOp);
                 length += mDNS_snprintf(buffer+length, RemSpc, " Err/Port %d", opt->u.llq.err);
@@ -418,6 +419,7 @@ mDNSexport char *GetRRDisplayString_rdb(const ResourceRecord *const rr, const RD
                 length += mDNS_snprintf(buffer+length, RemSpc, " Lease %d",    opt->u.updatelease);
                 break;
             case kDNSOpt_Owner:
+                length += mDNS_snprintf(buffer+length, RemSpc, " Owner");
                 length += mDNS_snprintf(buffer+length, RemSpc, " Vers %d",     opt->u.owner.vers);
                 length += mDNS_snprintf(buffer+length, RemSpc, " Seq %3d", (mDNSu8)opt->u.owner.seq);                           // Display as unsigned
                 length += mDNS_snprintf(buffer+length, RemSpc, " MAC %.6a",    opt->u.owner.HMAC.b);
@@ -429,6 +431,7 @@ mDNSexport char *GetRRDisplayString_rdb(const ResourceRecord *const rr, const RD
                 }
                 break;
             case kDNSOpt_Trace:
+                length += mDNS_snprintf(buffer+length, RemSpc, " Trace");
                 length += mDNS_snprintf(buffer+length, RemSpc, " Platform %d",    opt->u.tracer.platf);
                 length += mDNS_snprintf(buffer+length, RemSpc, " mDNSVers %d",    opt->u.tracer.mDNSv);
                 break;
@@ -3201,6 +3204,12 @@ mDNSexport mDNSBool SetRData(const DNSMessage *const msg, const mDNSu8 *ptr, con
                     opt->u.tracer.mDNSv   = (mDNSu32) ((mDNSu32)ptr[1] << 24 | (mDNSu32)ptr[2] << 16 | (mDNSu32)ptr[3] << 8 | ptr[4]);
                     opt++;
                 }
+                else
+                {
+                    opt->u.tracer.platf   = 0xFF;
+                    opt->u.tracer.mDNSv   = 0xFFFFFFFF;
+                    opt++;
+                }
                 break;
             }
             ptr += currentopt->optlen;
diff --git a/mDNSResponder/mDNSCore/mDNS.c b/mDNSResponder/mDNSCore/mDNS.c
index 71c7a395..e15b7cf8 100755
--- a/mDNSResponder/mDNSCore/mDNS.c
+++ b/mDNSResponder/mDNSCore/mDNS.c
@@ -23,7 +23,7 @@
  * routines, or types (which may or may not be present on any given platform).
  */
 
-#include "DNSCommon.h"                  // Defines general DNS untility routines
+#include "DNSCommon.h"                  // Defines general DNS utility routines
 #include "uDNS.h"                       // Defines entry points into unicast-specific routines
 #include "nsec.h"
 #include "dnssec.h"
@@ -11170,7 +11170,7 @@ mDNSlocal mDNSBool CacheRecordRmvEventsForQuestion(mDNS *const m, DNSQuestion *q
 mDNSlocal void SuppressStatusChanged(mDNS *const m, DNSQuestion *q, DNSQuestion **restart)
 {
     // NOTE: CacheRecordRmvEventsForQuestion will not generate RMV events for queries that have non-zero
-    // LOddressAnswers. Hence it is important that we call CacheRecordRmvEventsForQuestion before
+    // LOAddressAnswers. Hence it is important that we call CacheRecordRmvEventsForQuestion before
     // LocalRecordRmvEventsForQuestion (which decrements LOAddressAnswers)
     if (q->SuppressQuery)
     {
diff --git a/mDNSResponder/mDNSCore/mDNSEmbeddedAPI.h b/mDNSResponder/mDNSCore/mDNSEmbeddedAPI.h
index 785ed3fe..81b4192b 100755
--- a/mDNSResponder/mDNSCore/mDNSEmbeddedAPI.h
+++ b/mDNSResponder/mDNSCore/mDNSEmbeddedAPI.h
@@ -96,6 +96,9 @@ extern "C" {
 #ifdef LIMITED_RESOURCES_TARGET
 // Don't support jumbo frames
 #define AbsoluteMaxDNSMessageData 	1500
+// By the time you add IPv6 header (40 bytes) UDP header (8 bytes) and DNS message header (12 bytes)
+// this makes 1560 which is 60 bytes over the standard Ethernet MTU. D'oh!
+
 // StandardAuthRDSize is 264 (256+8), which is large enough to hold a maximum-sized SRV record (6 + 256 bytes)
 #define MaximumRDSize				264
 // Don't cache anything
diff --git a/mDNSResponder/mDNSCore/uDNS.c b/mDNSResponder/mDNSCore/uDNS.c
index be7a5a32..8c7c3300 100755
--- a/mDNSResponder/mDNSCore/uDNS.c
+++ b/mDNSResponder/mDNSCore/uDNS.c
@@ -1329,7 +1329,8 @@ mDNSlocal void tcpCallback(TCPSocket *sock, void *context, mDNSBool ConnectionEs
     else
     {
         long n;
-        if (tcpInfo->nread < 2)         // First read the two-byte length preceeding the DNS message
+        const mDNSBool Read_replylen = (tcpInfo->nread < 2);  // Do we need to read the replylen field first?
+        if (Read_replylen)         // First read the two-byte length preceeding the DNS message
         {
             mDNSu8 *lenptr = (mDNSu8 *)&tcpInfo->replylen;
             n = mDNSPlatformReadTCP(sock, lenptr + tcpInfo->nread, 2 - tcpInfo->nread, &closed);
@@ -1377,8 +1378,13 @@ mDNSlocal void tcpCallback(TCPSocket *sock, void *context, mDNSBool ConnectionEs
 
         if (n < 0)
         {
-            LogMsg("ERROR: tcpCallback - read returned %d", n);
-            err = mStatus_ConnFailed;
+            // If this is our only read for this invokation, and it fails, then that's bad.
+            // But if we did successfully read some or all of the replylen field this time through,
+            // and this is now our second read from the socket, then it's expected that sometimes
+            // there may be no more data present, and that's perfectly okay.
+            // Assuming failure of the second read is a problem is what caused this bug:
+            // <rdar://problem/15043194> mDNSResponder fails to read DNS over TCP packet correctly
+            if (!Read_replylen) { LogMsg("ERROR: tcpCallback - read returned %d", n); err = mStatus_ConnFailed; }
             goto exit;
         }
         else if (closed)