Fix a zone refresh bug in zone.c:refresh_callback()

When the zone.c:refresh_callback() callback function is called during
a SOA request before a zone transfer, it can receive a
ISC_R_SHUTTINGDOWN result for the sent request when named is shutting
down, and in that case it just destroys the request and finishes the
ongoing transfer, without clearing the DNS_ZONEFLG_REFRESH flag of the
zone. This is alright when named is going to shutdown, but currently
the callback can get a ISC_R_SHUTTINGDOWN result also when named is
reconfigured during the ongoibg SOA request. In that case, leaving the
DNS_ZONEFLG_REFRESH flag set results in the zone never being able
to refresh again, because any new attempts will be caneled while
the flag is set. Clear the DNS_ZONEFLG_REFRESH flag on the 'exiting'
error path of the callback function.

(cherry picked from commit 228e441328af8f3a54c1ae3f0cd7b871dab83609)

diff --git a/lib/dns/zone.c b/lib/dns/zone.c
index d539d4695b5d48060427d8bf50ae28202fd1ccaf..bf0ba0ecadb3876416d09efdc2c0c2bb67583105 100644 (file)
--- a/lib/dns/zone.c
+++ b/lib/dns/zone.c
@@ -14308,6 +14308,17 @@ next_primary:
        goto detach;
 
 exiting:
+       /*
+        * We can get here not only during shutdown, but also when the refresh
+        * is canceled during reconfiguration. In that case, make sure to clear
+        * the DNS_ZONEFLG_REFRESH flag so that future zone refreshes don't get
+        * stuck, and make sure a new refresh attempt is made again soon after
+        * the reconfiguration is complete.
+        */
+       DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_REFRESH);
+       zone->refreshtime = now;
+       zone_settimer(zone, &now);
+
        dns_request_destroy(&zone->request);
        goto detach;