diff --git a/coredns_plugin/coredns_plugin.go b/coredns_plugin/coredns_plugin.go index 195a9218..4b00eca6 100644 --- a/coredns_plugin/coredns_plugin.go +++ b/coredns_plugin/coredns_plugin.go @@ -45,6 +45,16 @@ func init() { }) } +type cacheEntry struct { + answer []dns.RR + lastUpdated time.Time +} + +var ( + lookupCacheTime = time.Minute * 30 + lookupCache = map[string]cacheEntry{} +) + type plugSettings struct { SafeBrowsingBlockHost string ParentalBlockHost string @@ -324,20 +334,29 @@ func (p *plug) replaceHostWithValAndReply(ctx context.Context, w dns.ResponseWri records = append(records, result) } else { // this is a domain name, need to look it up - req := new(dns.Msg) - req.SetQuestion(dns.Fqdn(val), question.Qtype) - req.RecursionDesired = true - reqstate := request.Request{W: w, Req: req, Context: ctx} - result, err := p.upstream.Lookup(reqstate, dns.Fqdn(val), reqstate.QType()) - if err != nil { - log.Printf("Got error %s\n", err) - return dns.RcodeServerFailure, fmt.Errorf("plugin/dnsfilter: %s", err) - } - if result != nil { - for _, answer := range result.Answer { - answer.Header().Name = question.Name + cacheentry := lookupCache[val] + if time.Since(cacheentry.lastUpdated) > lookupCacheTime { + req := new(dns.Msg) + req.SetQuestion(dns.Fqdn(val), question.Qtype) + req.RecursionDesired = true + reqstate := request.Request{W: w, Req: req, Context: ctx} + result, err := p.upstream.Lookup(reqstate, dns.Fqdn(val), reqstate.QType()) + if err != nil { + log.Printf("Got error %s\n", err) + return dns.RcodeServerFailure, fmt.Errorf("plugin/dnsfilter: %s", err) } - records = result.Answer + if result != nil { + for _, answer := range result.Answer { + answer.Header().Name = question.Name + } + records = result.Answer + cacheentry.answer = result.Answer + cacheentry.lastUpdated = time.Now() + lookupCache[val] = cacheentry + } + } else { + // get from cache + records = cacheentry.answer } } m := new(dns.Msg) diff --git a/dnsfilter/dnsfilter.go b/dnsfilter/dnsfilter.go index 1344ea9f..ec2ad5f7 100644 --- a/dnsfilter/dnsfilter.go +++ b/dnsfilter/dnsfilter.go @@ -16,6 +16,7 @@ import ( "sync/atomic" "time" + _ "github.com/benburkert/dns/init" "github.com/bluele/gcache" "golang.org/x/net/publicsuffix" )