From: Mark Andrews <marka@isc.org>
Date: Thu, 29 Aug 2024 01:05:09 +0000 (+1000)
Subject: Add dns_zone_getzoneversion
X-Git-Tag: v9.21.7~34^2~8
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ebe751f88cd4a473b9b732367812aaadcb2b8643;p=thirdparty%2Fbind9.git

Add dns_zone_getzoneversion

Returns the EDNS ZONEVERSION for the zone.  Return the database
specific version otherwise return a type 0 version (serial).
---

diff --git a/lib/dns/include/dns/zone.h b/lib/dns/include/dns/zone.h
index b000f27e103..cec638fe64a 100644
--- a/lib/dns/include/dns/zone.h
+++ b/lib/dns/include/dns/zone.h
@@ -2785,6 +2785,24 @@ dns_zone_getrad(dns_zone_t *zone, dns_name_t *name);
  * \li	'name' is a valid name with a buffer.
  */
 
+isc_result_t
+dns_zone_getzoneversion(dns_zone_t *zone, isc_buffer_t *b);
+/**<
+ * Return the EDNS ZONEVERSION for this zone.
+ *
+ * Note: For type SERIAL a buffer of at least 6 octets is required.
+ *
+ * Requires:
+ * \li	'zone' to be a valid zone.
+ * \li	'b' to be a valid buffer.
+ *
+ * Returns
+ * \li	ISC_R_SUCCESS if the zone is loaded and supports ZONEVERSION.
+ * \li	ISC_R_NOSPACE if the buffer is too small.
+ * \li	DNS_R_NOTLOADED if the database is not loaded.
+ * \li	ISC_R_FAILURE other failure.
+ */
+
 #if DNS_ZONE_TRACE
 #define dns_zone_ref(ptr)   dns_zone__ref(ptr, __func__, __FILE__, __LINE__)
 #define dns_zone_unref(ptr) dns_zone__unref(ptr, __func__, __FILE__, __LINE__)
diff --git a/lib/dns/zone.c b/lib/dns/zone.c
index 1ec93ef51c7..8d4c101f32d 100644
--- a/lib/dns/zone.c
+++ b/lib/dns/zone.c
@@ -1497,6 +1497,46 @@ dns_zone_getserial(dns_zone_t *zone, uint32_t *serialp) {
 	return result;
 }
 
+isc_result_t
+dns_zone_getzoneversion(dns_zone_t *zone, isc_buffer_t *b) {
+	isc_result_t result = DNS_R_NOTLOADED;
+	unsigned int soacount;
+	uint32_t serial;
+
+	REQUIRE(DNS_ZONE_VALID(zone));
+	REQUIRE(b != NULL);
+
+	LOCK_ZONE(zone);
+	ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
+	if (zone->db != NULL) {
+		result = dns_db_getzoneversion(zone->db, b);
+		if (result == ISC_R_NOTIMPLEMENTED) {
+			result = zone_get_from_db(zone, zone->db, NULL,
+						  &soacount, NULL, &serial,
+						  NULL, NULL, NULL, NULL, NULL);
+			if (result == ISC_R_SUCCESS && soacount == 0) {
+				result = ISC_R_FAILURE;
+			}
+			if (result == ISC_R_SUCCESS) {
+				if (isc_buffer_availablelength(b) >= 6) {
+					isc_buffer_putuint8(
+						b, dns_name_countlabels(
+							   &zone->origin) -
+							   1);
+					isc_buffer_putuint8(b, 0);
+					isc_buffer_putuint32(b, serial);
+				} else {
+					result = ISC_R_NOSPACE;
+				}
+			}
+		}
+	}
+	ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
+	UNLOCK_ZONE(zone);
+
+	return result;
+}
+
 /*
  *	Single shot.
  */