recursor: Check size when adding the OPT RR

diff --git a/pdns/pdns_recursor.cc b/pdns/pdns_recursor.cc
index 3b0829e0d400f2d59ad27fd54e392c39eb1fd893..5947c775a13dfd99c7335e16e766ca85f8089d1e 100644 (file)
--- a/pdns/pdns_recursor.cc
+++ b/pdns/pdns_recursor.cc
@@ -1304,6 +1304,10 @@ static void startDoResolve(void *p)
         }
       }
       pw.addOpt(g_udpTruncationThreshold, 0, DNSSECOK ? EDNSOpts::DNSSECOK : 0, opts);
+      if (pw.size() > maxanswersize) {
+        pw.rollback();
+        pw.addOpt(g_udpTruncationThreshold, 0, DNSSECOK ? EDNSOpts::DNSSECOK : 0, opts);
+      }
       pw.commit();
     }