From: Aram Sargsyan <aram@isc.org>
Date: Thu, 27 Feb 2025 11:52:30 +0000 (+0000)
Subject: Fix a bug in dns_zone_getprimaryaddr()
X-Git-Tag: ondrej/lock-free-qpzone-reads-v1~12^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7293cb0612e9362ad78f5c318b767a4f8ce16451;p=thirdparty%2Fbind9.git

Fix a bug in dns_zone_getprimaryaddr()

When all the addresses were already iterated over, the
dns_remote_curraddr() function asserts. So before calling it,
dns_zone_getprimaryaddr() now checks the address list using the
dns_remote_done() function. This also means that instead of
returning 'isc_sockaddr_t' it now returns 'isc_result_t' and
writes the primary's address into the provided pointer only when
returning success.
---

diff --git a/bin/named/statschannel.c b/bin/named/statschannel.c
index 4df131de2f9..e872d492b35 100644
--- a/bin/named/statschannel.c
+++ b/bin/named/statschannel.c
@@ -1617,9 +1617,13 @@ xfrin_xmlrender(dns_zone_t *zone, void *arg) {
 		isc_sockaddr_format(addrp, addr_buf, sizeof(addr_buf));
 		TRY0(xmlTextWriterWriteString(writer, ISC_XMLCHAR addr_buf));
 	} else if (is_presoa) {
-		addr = dns_zone_getprimaryaddr(zone);
-		isc_sockaddr_format(&addr, addr_buf, sizeof(addr_buf));
-		TRY0(xmlTextWriterWriteString(writer, ISC_XMLCHAR addr_buf));
+		if (dns_zone_getprimaryaddr(zone, &addr) == ISC_R_SUCCESS) {
+			isc_sockaddr_format(&addr, addr_buf, sizeof(addr_buf));
+			TRY0(xmlTextWriterWriteString(writer,
+						      ISC_XMLCHAR addr_buf));
+		} else {
+			TRY0(xmlTextWriterWriteString(writer, ISC_XMLCHAR "-"));
+		}
 	} else {
 		TRY0(xmlTextWriterWriteString(writer, ISC_XMLCHAR "-"));
 	}
@@ -2671,10 +2675,15 @@ xfrin_jsonrender(dns_zone_t *zone, void *arg) {
 		json_object_object_add(xfrinobj, "remoteaddr",
 				       json_object_new_string(addr_buf));
 	} else if (is_presoa) {
-		addr = dns_zone_getprimaryaddr(zone);
-		isc_sockaddr_format(&addr, addr_buf, sizeof(addr_buf));
-		json_object_object_add(xfrinobj, "remoteaddr",
-				       json_object_new_string(addr_buf));
+		if (dns_zone_getprimaryaddr(zone, &addr) == ISC_R_SUCCESS) {
+			isc_sockaddr_format(&addr, addr_buf, sizeof(addr_buf));
+			json_object_object_add(
+				xfrinobj, "remoteaddr",
+				json_object_new_string(addr_buf));
+		} else {
+			json_object_object_add(xfrinobj, "remoteaddr",
+					       json_object_new_string("-"));
+		}
 	} else {
 		json_object_object_add(xfrinobj, "remoteaddr",
 				       json_object_new_string("-"));
diff --git a/lib/dns/include/dns/zone.h b/lib/dns/include/dns/zone.h
index 63b39eb1b87..02ae1e99d5e 100644
--- a/lib/dns/include/dns/zone.h
+++ b/lib/dns/include/dns/zone.h
@@ -1539,14 +1539,19 @@ dns_zone_getsourceaddr(dns_zone_t *zone);
  * \li	'zone' has a non-empty primaries list.
  */
 
-isc_sockaddr_t
-dns_zone_getprimaryaddr(dns_zone_t *zone);
+isc_result_t
+dns_zone_getprimaryaddr(dns_zone_t *zone, isc_sockaddr_t *dest);
 /*%<
- * Get the zone's current primary server.
+ * Get the zone's current primary server into '*dest'.
  *
  * Requires:
  * \li	'zone' to be a valid zone.
  * \li	'zone' has a non-empty primaries list.
+ * \li	'dest' != NULL.
+ *
+ * Returns:
+ *\li	#ISC_R_SUCCESS if the current primary server was found
+ *\li	#ISC_R_NOMORE if all the primaries were already iterated over
  */
 
 isc_time_t
diff --git a/lib/dns/zone.c b/lib/dns/zone.c
index ca1d48e1eec..536c8f3752a 100644
--- a/lib/dns/zone.c
+++ b/lib/dns/zone.c
@@ -18385,18 +18385,22 @@ dns_zone_getsourceaddr(dns_zone_t *zone) {
 	return sourceaddr;
 }
 
-isc_sockaddr_t
-dns_zone_getprimaryaddr(dns_zone_t *zone) {
-	isc_sockaddr_t curraddr;
+isc_result_t
+dns_zone_getprimaryaddr(dns_zone_t *zone, isc_sockaddr_t *dest) {
+	isc_result_t result = ISC_R_NOMORE;
 
 	REQUIRE(DNS_ZONE_VALID(zone));
+	REQUIRE(dest != NULL);
 
 	LOCK_ZONE(zone);
 	INSIST(dns_remote_count(&zone->primaries) > 0);
-	curraddr = dns_remote_curraddr(&zone->primaries);
+	if (!dns_remote_done(&zone->primaries)) {
+		*dest = dns_remote_curraddr(&zone->primaries);
+		result = ISC_R_SUCCESS;
+	}
 	UNLOCK_ZONE(zone);
 
-	return curraddr;
+	return result;
 }
 
 isc_time_t