From 5ee80f1a7a07eac257e497833c9db58ee5d8ba3a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sa=C3=BAl=20Ibarra=20Corretg=C3=A9?= <saghul@gmail.com>
Date: Thu, 28 Jun 2012 08:48:54 +0200
Subject: [PATCH] c-ares: ignore rogue DNS servers reported by windows

---
 src/ares/ares_init.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/ares/ares_init.c b/src/ares/ares_init.c
index f9eb05450..4aef21ad4 100644
--- a/src/ares/ares_init.c
+++ b/src/ares/ares_init.c
@@ -1012,6 +1012,11 @@ static int get_DNS_AdaptersAddresses(char **outptr)
       }
       else if (namesrvr.sa->sa_family == AF_INET6)
       {
+        /* Windows apparently always reports some IPv6 DNS servers that
+         * prefixed with fec0:0:0:ffff. These ususally do not point to
+         * working DNS servers, so we ignore them. */
+        if (strncmp(txtaddr, "fec0:0:0:ffff:", 14) == 0)
+          continue;
         if (memcmp(&namesrvr.sa6->sin6_addr, &ares_in6addr_any,
                    sizeof(namesrvr.sa6->sin6_addr)) == 0)
           continue;