From 6ba259b62639fa1fd6009e99bc541dfc42ef6fee Mon Sep 17 00:00:00 2001
From: Mukund Sivaraman <muks@isc.org>
Date: Mon, 8 Feb 2016 15:10:50 +0530
Subject: [PATCH] Remove nodechain from dns_rbt_addnode() (#41246)

(cherry picked from commit 9267cc8e83c4f3cf98cdebe6553143812250becc)
(cherry picked from commit 6f3e21cd9bacdacfe203f31d1eca4fe85c372138)
---
 lib/dns/rbt.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/lib/dns/rbt.c b/lib/dns/rbt.c
index 18aba8d3ef..989e5ff02b 100644
--- a/lib/dns/rbt.c
+++ b/lib/dns/rbt.c
@@ -397,7 +397,7 @@ dns_rbt_addnode(dns_rbt_t *rbt, dns_name_t *name, dns_rbtnode_t **nodep) {
 	dns_offsets_t current_offsets;
 	dns_namereln_t compared;
 	isc_result_t result = ISC_R_SUCCESS;
-	dns_rbtnodechain_t chain;
+	unsigned int level_count;
 	unsigned int common_labels;
 	unsigned int nlabels, hlabels;
 	int order;
@@ -460,7 +460,7 @@ dns_rbt_addnode(dns_rbt_t *rbt, dns_name_t *name, dns_rbtnode_t **nodep) {
 		return (result);
 	}
 
-	dns_rbtnodechain_init(&chain, rbt->mctx);
+	level_count = 0;
 
 	dns_fixedname_init(&fixedprefix);
 	dns_fixedname_init(&fixedsuffix);
@@ -539,8 +539,9 @@ dns_rbt_addnode(dns_rbt_t *rbt, dns_name_t *name, dns_rbtnode_t **nodep) {
 
 				parent = NULL;
 				child = DOWN(current);
-				ADD_LEVEL(&chain, current);
 
+				INSIST(level_count < DNS_RBT_LEVELBLOCK);
+				level_count++;
 			} else {
 				/*
 				 * The number of labels in common is fewer
@@ -567,9 +568,7 @@ dns_rbt_addnode(dns_rbt_t *rbt, dns_name_t *name, dns_rbtnode_t **nodep) {
 				 * a simple integer variable, but I am pressed
 				 * for time.
 				 */
-				if (chain.level_count ==
-				    (sizeof(chain.levels) /
-				     sizeof(*chain.levels))) {
+				if (level_count >= DNS_RBT_LEVELBLOCK) {
 					result = ISC_R_NOSPACE;
 					break;
 				}
@@ -636,7 +635,9 @@ dns_rbt_addnode(dns_rbt_t *rbt, dns_name_t *name, dns_rbtnode_t **nodep) {
 				UPPERNODE(new_current) = UPPERNODE(current);
 				UPPERNODE(current) = new_current;
 #endif /* DNS_RBT_USEHASH */
-				ADD_LEVEL(&chain, new_current);
+
+				INSIST(level_count < DNS_RBT_LEVELBLOCK);
+				level_count++;
 
 				LEFT(current) = NULL;
 				RIGHT(current) = NULL;