Save first matched DSYNC record

Only save the DSYNC target and port when a record matches CDS NOTIFY,
then after scanning the complete RRset require count == 1 before using
the stored values.

diff --git a/lib/dns/zone.c b/lib/dns/zone.c
index d04e01d4c76b252d0b739ff9239f227e4a05cfc7..e6ee06e21bee78baea5d65c05bb046b400fbded3 100644 (file)
--- a/lib/dns/zone.c
+++ b/lib/dns/zone.c
@@ -18167,6 +18167,9 @@ dsyncfetch_done(dns_zonefetch_t *fetch, isc_result_t eresult) {
        dns_name_t *dsyncname = NULL;
        char dsyncnamebuf[DNS_NAME_FORMATSIZE];
        dns_rdataset_t *rrset = NULL;
+       in_port_t port = 0;
+       dns_fixedname_t fixed;
+       dns_name_t *target = dns_fixedname_initname(&fixed);
 
        REQUIRE(fetch != NULL);
        REQUIRE(fetch->fetchtype == ZONEFETCHTYPE_DSYNC);
@@ -18227,6 +18230,12 @@ dsyncfetch_done(dns_zonefetch_t *fetch, isc_result_t eresult) {
                        continue;
                }
 
+               /* Save matched DSYNC record. */
+               if (count == 0) {
+                       port = dsync.port;
+                       dns_name_copy(&dsync.target, target);
+               }
+
                count++;
                if (count > 1) {
                        dns_zone_log(zone, ISC_LOG_WARNING,
@@ -18243,27 +18252,41 @@ dsyncfetch_done(dns_zonefetch_t *fetch, isc_result_t eresult) {
        if (result == ISC_R_NOMORE) {
                result = ISC_R_SUCCESS;
        } else {
+               /* We didn't scan the complete RRset. */
+               goto done;
+       }
+
+       /*
+        * Only one NOTIFY can be queued per type.
+        * Currently the only supported scheme/type is NOTIFY CDS.
+        * The port and target from the first matched DSYNC record are saved in
+        * 'port' and 'target'.
+        */
+       if (count != 1) {
+               /*
+                * Either count equals zero, and there is nothing to be queued.
+                * Or count > 1, then this is an invalid DSYNC RRset.
+                */
                goto done;
        }
 
        bool isqueued = dns_notify_isqueued(&zone->notifycds, dns_rdatatype_cds,
-                                           dsync.port, 0, &dsync.target, NULL,
-                                           NULL, NULL);
+                                           port, 0, target, NULL, NULL, NULL);
 
        UNLOCK_ZONE(zone);
 
        if (!isqueued) {
-               dns_notify_create(zone->mctx, dns_rdatatype_cds, dsync.port,
+               dns_notify_create(zone->mctx, dns_rdatatype_cds, port,
                                  DNS_NOTIFY_NOSOA, &notify);
                if (isc_log_wouldlog(ISC_LOG_DEBUG(3))) {
                        char tbuf[DNS_NAME_FORMATSIZE];
-                       dns_name_format(&dsync.target, tbuf, sizeof(tbuf));
+                       dns_name_format(target, tbuf, sizeof(tbuf));
                        dns_zone_log(zone, ISC_LOG_DEBUG(3),
                                     "dsyncfetch: send NOTIFY(CDS) query to %s",
                                     tbuf);
                }
                dns_zone_iattach(zone, &notify->zone);
-               dns_name_dup(&dsync.target, zone->mctx, &notify->ns);
+               dns_name_dup(target, zone->mctx, &notify->ns);
                LOCK_ZONE(zone);
                ISC_LIST_APPEND(zone->notifycds.notifies, notify, link);
                UNLOCK_ZONE(zone);