From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Wed, 19 Oct 2022 09:58:33 +0000 (+0200)
Subject: dnsdist: Also handle XFR responses with a lower serial than the query
X-Git-Tag: dnsdist-1.8.0-rc1~150^2~2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e09d3a8fcdf5077ee3449bd94d27d37b8ba218a1;p=thirdparty%2Fpdns.git

dnsdist: Also handle XFR responses with a lower serial than the query

As suggested by Håkan Lindqvist (thanks!).
---

diff --git a/pdns/dnsdistdist/dnsdist-tcp-downstream.cc b/pdns/dnsdistdist/dnsdist-tcp-downstream.cc
index ebe795529d..0242841f7f 100644
--- a/pdns/dnsdistdist/dnsdist-tcp-downstream.cc
+++ b/pdns/dnsdistdist/dnsdist-tcp-downstream.cc
@@ -803,7 +803,7 @@ bool TCPConnectionToBackend::isXFRFinished(const TCPResponse& response, TCPQuery
         if (query.d_xfrMasterSerial == 0) {
           // store the first SOA in our client's connection metadata
           query.d_xfrMasterSerial = serial;
-          if (query.d_xfrMasterSerial == query.d_xfrQuerySerial) {
+          if (query.d_xfrMasterSerial <= query.d_xfrQuerySerial) {
             /* This is the first message with a master SOA:
                RFC 1995 Section 2:
                  If an IXFR query with the same or newer version number