From: Otto <otto.moerbeek@open-xchange.com>
Date: Tue, 11 May 2021 11:48:27 +0000 (+0200)
Subject: Check if we have room before adding zero ecs scope ENDS value
X-Git-Tag: rec-4.4.4^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=722f8d0736d6a10a230ed9de7ce39ed49f75341b;p=thirdparty%2Fpdns.git

Check if we have room before adding zero ecs scope ENDS value
---

diff --git a/pdns/pdns_recursor.cc b/pdns/pdns_recursor.cc
index 93d77b98fb..22519cac20 100644
--- a/pdns/pdns_recursor.cc
+++ b/pdns/pdns_recursor.cc
@@ -1782,8 +1782,11 @@ static void startDoResolve(void *p)
       sa.reset();
       sa.sin4.sin_family = eo.source.getNetwork().sin4.sin_family;
       eo.scope = Netmask(sa, 0);
+      auto ecsPayload = makeEDNSSubnetOptsString(eo);
 
-      returnedEdnsOptions.push_back(make_pair(EDNSOptionCode::ECS, makeEDNSSubnetOptsString(eo)));
+      if (pw.size() < maxanswersize && (maxanswersize - pw.size()) >= (2 + 2 + ecsPayload.size())) {
+        returnedEdnsOptions.push_back(make_pair(EDNSOptionCode::ECS, std::move(ecsPayload)));
+      }
     }
 
     if (haveEDNS) {