From fabe20ff0d5e45add363e5d67407603ea03cb0ec Mon Sep 17 00:00:00 2001
From: Brad Spencer <spencer@jacknife.org>
Date: Wed, 20 Dec 2017 13:49:49 -0400
Subject: [PATCH] Fix computation of IPv6 blacklist mask for values of netmask
 > 8. (#164)

---
 ares_init.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/ares_init.c b/ares_init.c
index d7d3a365..8e4b527a 100644
--- a/ares_init.c
+++ b/ares_init.c
@@ -1009,8 +1009,8 @@ static int ares_ipv6_subnet_matches(const unsigned char netbase[16],
   memset(mask, 0xFF, netmask / 8);
 
   /* Set remaining bits */
-  for (i=(netmask / 8)*8; i<netmask; i++) {
-    mask[i / 8] |= (1 << ((7-i) % 8)) & 0xFF;
+  if(netmask % 8) {
+    mask[netmask / 8] = (unsigned char)(0xff << (8 - (netmask % 8)));
   }
 
   for (i=0; i<16; i++) {