[svn] commit: r2792 - in /branches/trac307/src/lib/datasrc: data_source.cc tests/datasrc_unittest.cc

[BIND 10 source code commits]

Author: jinmei
Date: Tue Aug 24 16:52:55 2010
New Revision: 2792

Log:
committed a proposed fix to trac #307

Modified:
    branches/trac307/src/lib/datasrc/data_source.cc
    branches/trac307/src/lib/datasrc/tests/datasrc_unittest.cc

Modified: branches/trac307/src/lib/datasrc/data_source.cc
==============================================================================
--- branches/trac307/src/lib/datasrc/data_source.cc (original)
+++ branches/trac307/src/lib/datasrc/data_source.cc Tue Aug 24 16:52:55 2010
@@ -206,6 +206,11 @@
         if (!hit || !rrset || (flags & DataSrc::CNAME_FOUND) != 0) {
             hit = cache.retrieve(task.qname, task.qclass, RRType::CNAME(),
                                  rrset, flags);
+            if (!rrset) {
+                // If we don't have a positive cache, forget it; otherwise the
+                // intermediate result may confuse the subsequent processing.
+                hit = false;
+            }
         }
 
         if (hit) {

Modified: branches/trac307/src/lib/datasrc/tests/datasrc_unittest.cc
==============================================================================
--- branches/trac307/src/lib/datasrc/tests/datasrc_unittest.cc (original)
+++ branches/trac307/src/lib/datasrc/tests/datasrc_unittest.cc Tue Aug 24 16:52:55 2010
@@ -915,6 +915,24 @@
     headerCheck(msg, Rcode::REFUSED(), true, false, true, 0, 0, 0);
 }
 
+TEST_F(DataSrcTest, DSQueryFromCache) {
+    // explicitly enable hot spot cache
+    cache.setEnabled(true);
+
+    // The first query will create a negative cache for example.org/CNAME
+    createAndProcessQuery(Name("example.org"), RRClass::IN(), RRType::SOA());
+
+    // the cached CNAME shouldn't confuse subsequent query.
+    // there may be several different possible cases that could trigger a bug,
+    // but DS query is the only known example.
+    msg.clear(Message::PARSE);
+    createAndProcessQuery(Name("example.org"), RRClass::IN(), RRType::DS());
+
+    // returning refused is probably a bad behavior, but it's a different
+    // issue.
+    headerCheck(msg, Rcode::REFUSED(), true, false, true, 0, 0, 0);
+}
+
 // Non-existent name in the "static" data source.  The purpose of this test
 // is to check a corner case behavior when atypical RRClass (CH in this case)
 // is specified.