Pull request: fix dns cache ttl check

Merge in DNS/adguard-home from 2459-dns-ttl to master

Updates #2459.

Squashed commit of the following:

commit 27e74e30b202ab5163ebdbc2c00622099b11a1ff
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Mon Dec 21 15:00:46 2020 +0300

    all: log changes

commit e476fa5c4b8fd3896fa401f4dc546a5d937746eb
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Mon Dec 21 14:55:30 2020 +0300

    dnsforward: fix dns cache ttl check

CHANGELOG.md

@@ -57,6 +57,7 @@ and this project adheres to
 
 ### Fixed
 
+- Inability to set DNS cache TTL limits ([#2459]).
 - Possible freezes on slower machines ([#2225]).
 - A mitigation against records being shown in the wrong order on the query log
   page ([#2293]).
@@ -68,6 +69,7 @@ and this project adheres to
 [#2293]: https://github.com/AdguardTeam/AdGuardHome/issues/2293
 [#2345]: https://github.com/AdguardTeam/AdGuardHome/issues/2345
 [#2355]: https://github.com/AdguardTeam/AdGuardHome/issues/2355
+[#2459]: https://github.com/AdguardTeam/AdGuardHome/issues/2459
 
 ### Removed
 

internal/dnsforward/http.go

@@ -167,11 +167,12 @@ func (req *dnsConfig) checkCacheTTL() bool {
 	if req.CacheMinTTL == nil && req.CacheMaxTTL == nil {
 		return true
 	}
+
 	var min, max uint32
 	if req.CacheMinTTL != nil {
 		min = *req.CacheMinTTL
 	}
-	if req.CacheMaxTTL == nil {
+	if req.CacheMaxTTL != nil {
 		max = *req.CacheMaxTTL
 	}
 

internal/dnsforward/msg.go

@@ -42,7 +42,6 @@ func (s *Server) genDNSFilterMessage(d *proxy.DNSContext, result *dnsfilter.Resu
 		if result.Reason == dnsfilter.FilteredSafeSearch &&
 			len(result.Rules) > 0 &&
 			result.Rules[0].IP != nil {
-
 			return s.genResponseWithIP(m, result.Rules[0].IP)
 		}