[9.20] fix: usr: Fix trying the next primary server when the preivous one was marked as unreachable

In some cases (there is evidence only when XoT was used) `named` failed
to try the next primary server in the list when the previous one was
marked as unreachable. This has been fixed.

Closes #5038

Backport of MR !9781

Merge branch 'backport-5038-xfr-primary-next-fix-9.20' into 'bind-9.20'

See merge request isc-projects/bind9!9788

bin/tests/system/xfer/ns1/named1.conf.in

@@ -63,6 +63,11 @@ zone "axfr-rndc-retransfer-force" {
 	file "axfr-rndc-retransfer-force.db";
 };
 
+zone "xot-primary-try-next" {
+	type primary;
+	file "xot-primary-try-next.db";
+};
+
 zone "axfr-too-big" {
 	type primary;
 	file "axfr-too-big.db";

bin/tests/system/xfer/ns1/xot-primary-try-next.db

@@ -0,0 +1,14 @@
+; Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+;
+; SPDX-License-Identifier: MPL-2.0
+;
+; This Source Code Form is subject to the terms of the Mozilla Public
+; License, v. 2.0.  If a copy of the MPL was not distributed with this
+; file, you can obtain one at https://mozilla.org/MPL/2.0/.
+;
+; See the COPYRIGHT file distributed with this work for additional
+; information regarding copyright ownership.
+
+$TTL	3600
+@	IN	SOA	. . 0 0 0 0 0
+@	IN	NS	.

bin/tests/system/xfer/ns6/named.conf.in

@@ -77,6 +77,12 @@ zone "axfr-rndc-retransfer-force" {
 	file "axfr-rndc-retransfer-force.bk";
 };
 
+zone "xot-primary-try-next" {
+	type secondary;
+	primaries { 10.53.0.99 port @EXTRAPORT1@ tls ephemeral; 10.53.0.1; };
+	file "xot-primary-try-next.bk";
+};
+
 zone "axfr-too-big" {
 	type secondary;
 	max-records 30;

bin/tests/system/xfer/tests.sh

@@ -646,6 +646,28 @@ wait_for_message() (
   grep -F "$1" wait_for_message.$n >/dev/null
 )
 
+nextpart ns6/named.run >/dev/null
+
+n=$((n + 1))
+echo_i "test that named tries the next primary in the list when the first one fails (XoT -> Do53) ($n)"
+tmp=0
+$RNDCCMD 10.53.0.6 retransfer xot-primary-try-next 2>&1 | sed 's/^/ns6 /' | cat_i
+msg="'xot-primary-try-next/IN' from 10.53.0.1#${PORT}: Transfer status: success"
+retry_quiet 60 wait_for_message "$msg" || tmp=1
+if test $tmp != 0; then echo_i "failed"; fi
+status=$((status + tmp))
+
+nextpart ns6/named.run >/dev/null
+
+n=$((n + 1))
+echo_i "test that named tries the next primary in the list when the first one is already marked as unreachable (XoT -> Do53) ($n)"
+tmp=0
+$RNDCCMD 10.53.0.6 retransfer xot-primary-try-next 2>&1 | sed 's/^/ns6 /' | cat_i
+msg="'xot-primary-try-next/IN' from 10.53.0.1#${PORT}: Transfer status: success"
+retry_quiet 60 wait_for_message "$msg" || tmp=1
+if test $tmp != 0; then echo_i "failed"; fi
+status=$((status + tmp))
+
 # Restart ns1 with -T transferslowly
 stop_server ns1
 copy_setports ns1/named2.conf.in ns1/named.conf
@@ -663,7 +685,7 @@ msg="'axfr-rndc-retransfer-force/IN' from 10.53.0.1#${PORT}: received"
 retry_quiet 5 wait_for_message "$msg" || tmp=1
 # Issue a retransfer-force command which should cancel the ongoing transfer and start a new one
 $RNDCCMD 10.53.0.6 retransfer -force axfr-rndc-retransfer-force 2>&1 | sed 's/^/ns6 /' | cat_i
-msg="'axfr-rndc-retransfer-force/IN' from 10.53.0.1#${PORT}: Transfer status: operation canceled"
+msg="'axfr-rndc-retransfer-force/IN' from 10.53.0.1#${PORT}: Transfer status: shutting down"
 retry_quiet 5 wait_for_message "$msg" || tmp=1
 # Wait for the new transfer to complete successfully
 msg="'axfr-rndc-retransfer-force/IN' from 10.53.0.1#${PORT}: Transfer status: success"

bin/tests/system/xfer/tests_sh_xfer.py

@@ -49,6 +49,7 @@ pytestmark = pytest.mark.extra_artifacts(
         "ns6/primary.db",
         "ns6/primary.db.jnl",
         "ns6/sec.bk",
+        "ns6/xot-primary-try-next.bk",
         "ns7/edns-expire.bk",
         "ns7/primary2.db",
         "ns7/sec.bk",

lib/dns/xfrin.c

@@ -1080,7 +1080,7 @@ xfrin_shutdown(void *arg) {
 
 	REQUIRE(VALID_XFRIN(xfr));
 
-	xfrin_fail(xfr, ISC_R_CANCELED, "shut down");
+	xfrin_fail(xfr, ISC_R_SHUTTINGDOWN, "shut down");
 	dns_xfrin_detach(&xfr);
 }
 
@@ -1092,7 +1092,7 @@ dns_xfrin_shutdown(dns_xfrin_t *xfr) {
 		dns_xfrin_ref(xfr);
 		isc_async_run(xfr->loop, xfrin_shutdown, xfr);
 	} else {
-		xfrin_fail(xfr, ISC_R_CANCELED, "shut down");
+		xfrin_fail(xfr, ISC_R_SHUTTINGDOWN, "shut down");
 	}
 }
 

lib/dns/zone.c

@@ -11474,11 +11474,23 @@ zone_refresh(dns_zone_t *zone) {
 	queue_soa_query(zone);
 }
 
-void
-dns_zone_refresh(dns_zone_t *zone) {
+static void
+zone_refresh_async(void *arg) {
+	dns_zone_t *zone = arg;
+
 	LOCK_ZONE(zone);
 	zone_refresh(zone);
 	UNLOCK_ZONE(zone);
+
+	dns_zone_detach(&zone);
+}
+
+void
+dns_zone_refresh(dns_zone_t *zone) {
+	REQUIRE(DNS_ZONE_VALID(zone));
+
+	dns_zone_ref(zone);
+	isc_async_run(zone->loop, zone_refresh_async, zone);
 }
 
 static isc_result_t
@@ -17946,17 +17958,6 @@ again:
 		inc_stats(zone, dns_zonestatscounter_xfrfail);
 		break;
 
-	case ISC_R_CANCELED:
-		/*
-		 * A new "retransfer" command with a "-force" argument could
-		 * have canceled the current transfer in which case we should
-		 * make sure to try again from the beginning.
-		 */
-		if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_FORCEXFER)) {
-			DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_REFRESH);
-			again = true;
-		}
-		FALLTHROUGH;
 	case ISC_R_SHUTTINGDOWN:
 		dns_remote_reset(&zone->primaries, true);
 		break;
@@ -19559,11 +19560,6 @@ void
 dns_zonemgr_unreachabledel(dns_zonemgr_t *zmgr, isc_sockaddr_t *remote,
 			   isc_sockaddr_t *local) {
 	unsigned int i;
-	char primary[ISC_SOCKADDR_FORMATSIZE];
-	char source[ISC_SOCKADDR_FORMATSIZE];
-
-	isc_sockaddr_format(remote, primary, sizeof(primary));
-	isc_sockaddr_format(local, source, sizeof(source));
 
 	REQUIRE(DNS_ZONEMGR_VALID(zmgr));