From ac4e389b128b95ce4edb97a086c86020066b982b Mon Sep 17 00:00:00 2001
From: Pieter Lexis <pieter.lexis@powerdns.com>
Date: Tue, 20 Feb 2018 18:06:46 +0100
Subject: [PATCH] recursor: Check size when adding the OPT RR

---
 pdns/pdns_recursor.cc | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/pdns/pdns_recursor.cc b/pdns/pdns_recursor.cc
index 3b0829e0d4..5947c775a1 100644
--- 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();
     }
 
-- 
2.47.3