From e4c4b7dda6eb55a48de6f961afae80bf2447b578 Mon Sep 17 00:00:00 2001
From: Baptiste Assmann <bedis9@gmail.com>
Date: Wed, 28 Oct 2015 02:10:02 +0100
Subject: [PATCH] BUG/MINOR: dns: unable to parse CNAMEs response

A bug lied in the parsing of DNS CNAME response, leading HAProxy to
think the CNAME was improperly resolved in the response.

This should be backported into 1.6 branch
---
 src/dns.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/dns.c b/src/dns.c
index 53b65ab8d..1348be3d9 100644
--- a/src/dns.c
+++ b/src/dns.c
@@ -628,8 +628,11 @@ int dns_get_ip_from_response(unsigned char *resp, unsigned char *resp_end,
 		else
 			ptr = reader;
 
-		if (cname && memcmp(ptr, cname, cnamelen))
-			return DNS_UPD_NAME_ERROR;
+		if (cname) {
+			if (memcmp(ptr, cname, cnamelen)) {
+				return DNS_UPD_NAME_ERROR;
+			}
+		}
 		else if (memcmp(ptr, dn_name, dn_name_len))
 			return DNS_UPD_NAME_ERROR;