From 10e905959ec0285804310cc32e08dc6d09af6209 Mon Sep 17 00:00:00 2001
From: Bob Halley <source@isc.org>
Date: Fri, 2 Apr 1999 03:37:24 +0000
Subject: [PATCH] When searching a cache db, we did not look for an NS record
 at the node, so we sometimes did not find the deepest zone cut.  E.g. If you
 look for A records at "com." then you should get a delegation for "com." and
 not one for ".". In the various rdataset find routines, we sometimes
 attempted to bind the rdataset even if the rdataset pointer was NULL. Remove
 inline from a few functions.  Add inline to a few others.

---
 lib/dns/rbtdb.c | 41 +++++++++++++++++++++++++++++++++--------
 1 file changed, 33 insertions(+), 8 deletions(-)

diff --git a/lib/dns/rbtdb.c b/lib/dns/rbtdb.c
index 49d82b3bc6..c3c1955189 100644
--- a/lib/dns/rbtdb.c
+++ b/lib/dns/rbtdb.c
@@ -283,7 +283,7 @@ free_rbtdb(dns_rbtdb_t *rbtdb) {
 	isc_mem_put(rbtdb->common.mctx, rbtdb, sizeof *rbtdb);
 }
 
-static void
+static inline void
 maybe_free_rbtdb(dns_rbtdb_t *rbtdb) {
 	isc_boolean_t want_free = ISC_TRUE;
 	unsigned int i;
@@ -426,7 +426,7 @@ free_rdataset(isc_mem_t *mctx, rdatasetheader_t *rdataset) {
 	isc_mem_put(mctx, rdataset, size);
 }
 
-static void
+static inline void
 rollback_node(dns_rbtdb_t *rbtdb, dns_rbtnode_t *node, rbtdb_serial_t serial) {
 	rdatasetheader_t *header, *header_next;
 
@@ -573,7 +573,7 @@ new_reference(dns_rbtdb_t *rbtdb, dns_rbtnode_t *node) {
 	INSIST(node->references != 0);
 }
 
-static inline void
+static void
 no_references(dns_rbtdb_t *rbtdb, dns_rbtnode_t *node,
 	      rbtdb_serial_t least_serial)
 {
@@ -1261,7 +1261,7 @@ zone_find(dns_db_t *db, dns_name_t *name, dns_dbversion_t *version,
 		result = DNS_R_SUCCESS;
 	}
 
-	if (type != dns_rdatatype_any)
+	if (rdataset != NULL && type != dns_rdatatype_any)
 		bind_rdataset(search.rbtdb, node, header, rdataset);
 
  node_exit:
@@ -1428,7 +1428,7 @@ cache_find(dns_db_t *db, dns_name_t *name, dns_dbversion_t *version,
 	rbtdb_search_t search;
 	isc_boolean_t cname_ok = ISC_TRUE;
 	isc_boolean_t empty_node;
-	rdatasetheader_t *header, *nxtheader;
+	rdatasetheader_t *header, *nsheader, *nxtheader;
 
 	/*
 	 * XXXRTH Currently this code has no support for negative caching,
@@ -1496,6 +1496,7 @@ cache_find(dns_db_t *db, dns_name_t *name, dns_dbversion_t *version,
 
 	LOCK(&(search.rbtdb->node_locks[node->locknum].lock));
 	
+	nsheader = NULL;
 	nxtheader = NULL;
 	empty_node = ISC_TRUE;
 	for (header = node->data; header != NULL; header = header->next) {
@@ -1514,6 +1515,13 @@ cache_find(dns_db_t *db, dns_name_t *name, dns_dbversion_t *version,
 			    (cname_ok &&  header->type ==
 			     dns_rdatatype_cname)) {
 				break;
+			} else if (header->type == dns_rdatatype_ns) {
+				/*
+				 * Remember a NS rdataset even if we're
+				 * not specifically looking for it, because
+				 * we might need it later.
+				 */
+				nsheader = header;
 			} else if (header->type == dns_rdatatype_nxt) {
 				/*
 				 * Remember a NXT rdataset even if we're
@@ -1545,6 +1553,22 @@ cache_find(dns_db_t *db, dns_name_t *name, dns_dbversion_t *version,
 		 * yet try to use the NXT that way, but this is the place to
 		 * do it.
 		 */
+
+		/*
+		 * If there is an NS rdataset at this node, then this is the
+		 * deepest zone cut.
+		 */
+		if (nsheader != NULL) {
+			new_reference(search.rbtdb, node);
+			*nodep = node;
+			bind_rdataset(search.rbtdb, node, nsheader, rdataset);
+			result = DNS_R_DELEGATION;
+			goto node_exit;
+		}
+
+		/*
+		 * Go find the deepest zone cut.
+		 */
 		UNLOCK(&(search.rbtdb->node_locks[node->locknum].lock));
 		goto find_ns;
 	}
@@ -1574,9 +1598,10 @@ cache_find(dns_db_t *db, dns_name_t *name, dns_dbversion_t *version,
 		result = DNS_R_SUCCESS;
 	}
 
-	if (type != dns_rdatatype_any)
+	if (rdataset != NULL && type != dns_rdatatype_any)
 		bind_rdataset(search.rbtdb, node, header, rdataset);
 
+ node_exit:
 	UNLOCK(&(search.rbtdb->node_locks[node->locknum].lock));
 	
  tree_exit:
@@ -1787,7 +1812,7 @@ allrdatasets(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version,
 	return (DNS_R_SUCCESS);
 }
 
-static inline dns_result_t
+static dns_result_t
 add(dns_rbtdb_t *rbtdb, dns_rbtnode_t *rbtnode, rbtdb_version_t *rbtversion,
     rdatasetheader_t *newheader, isc_boolean_t merge, isc_boolean_t loading)
 {
@@ -2496,7 +2521,7 @@ rdatasetiter_current(dns_rdatasetiter_t *iterator, dns_rdataset_t *rdataset) {
  * Database Iterator Methods
  */
 
-static dns_result_t
+static inline dns_result_t
 resume_iteration(rbtdb_dbiterator_t *rbtiterator) {
 	return (DNS_R_NOTIMPLEMENTED);
 }