From 0794704f740db3c6ab73ee4d6287dc6f40ec4911 Mon Sep 17 00:00:00 2001
From: Aleksey Dmitrevskiy <ad@adguard.com>
Date: Tue, 23 Apr 2019 15:08:41 +0300
Subject: [PATCH] - dnsfilter: fix safesearch issue #268

---
 dnsfilter/dnsfilter.go | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/dnsfilter/dnsfilter.go b/dnsfilter/dnsfilter.go
index c487d7d2..20ca4222 100644
--- a/dnsfilter/dnsfilter.go
+++ b/dnsfilter/dnsfilter.go
@@ -649,15 +649,17 @@ func (d *Dnsfilter) checkSafeSearch(host string) (Result, error) {
 		return Result{}, err
 	}
 
-	res.IP = addrs[0]
-	// The next bug may occurs: LookupIP returns DNS64 mapped ipv4 address with zero-prefix
 	for _, i := range addrs {
-		if ipv4 := i.To4(); ipv4 != nil && len(i) == net.IPv6len {
+		if ipv4 := i.To4(); ipv4 != nil {
 			res.IP = ipv4
 			break
 		}
 	}
 
+	if len(res.IP) == 0 {
+		return Result{}, fmt.Errorf("no ipv4 addresses in safe search response for %s", safeHost)
+	}
+
 	// Cache result
 	err = safeSearchCache.Set(host, res)
 	if err != nil {