moved handle of blacklist domains

blacklist.go

@@ -3,12 +3,18 @@ package main
 import (
 	"io/ioutil"
 	"log"
+	"net"
 	"net/http"
 	"regexp"
 
 	"github.com/miekg/dns"
 )
 
+const blockTTL uint32 = 300
+
+var nullIPv4 = net.IPv4(0, 0, 0, 0)
+var nullIPv6 = net.ParseIP("::/0")
+
 func loadBlacklist(config []configBlacklist) map[string]bool {
 	list := make([]string, 0)
 	for _, element := range config {
@@ -77,3 +83,33 @@ func parseRawBlacklist(blacklist configBlacklist, raw string) []string {
 
 	return finalList
 }
+
+func handleBlockedDomain(w dns.ResponseWriter, r *dns.Msg) {
+	q := r.Question[0]
+
+	m := new(dns.Msg)
+	m.SetReply(r)
+	if q.Qtype == dns.TypeA {
+		m.Answer = append(m.Answer, &dns.A{
+			Hdr: dns.RR_Header{
+				Name:   q.Name,
+				Rrtype: dns.TypeA,
+				Class:  dns.ClassINET,
+				Ttl:    blockTTL,
+			},
+			A: nullIPv4,
+		})
+	} else if q.Qtype == dns.TypeAAAA {
+		m.Answer = append(m.Answer, &dns.AAAA{
+			Hdr: dns.RR_Header{
+				Name:   q.Name,
+				Rrtype: dns.TypeAAAA,
+				Class:  dns.ClassINET,
+				Ttl:    blockTTL,
+			},
+			AAAA: nullIPv6,
+		})
+	}
+
+	w.WriteMsg(m)
+}

coolDns.go

@@ -205,33 +205,7 @@ func createServer(zones zoneMap, config config, aclList map[string]*net.IPNet, b
 		}
 
 		if _, ok := blacklist[r.Question[0].Name]; ok {
-			// Domain is blocked
-			m := new(dns.Msg)
-			m.SetReply(r)
-			if r.Question[0].Qtype == dns.TypeA {
-				m.Answer = append(m.Answer, &dns.A{
-					Hdr: dns.RR_Header{
-						Name:   r.Question[0].Name,
-						Rrtype: dns.TypeA,
-						Class:  dns.ClassINET,
-						Ttl:    1000,
-					},
-					A: net.IPv4(0, 0, 0, 0),
-				})
-			} else if r.Question[0].Qtype == dns.TypeAAAA {
-				m.Answer = append(m.Answer, &dns.AAAA{
-					Hdr: dns.RR_Header{
-						Name:   r.Question[0].Name,
-						Rrtype: dns.TypeA,
-						Class:  dns.ClassINET,
-						Ttl:    1000,
-					},
-					AAAA: net.ParseIP("::/0"),
-				})
-			}
-
-			w.WriteMsg(m)
-
+			handleBlockedDomain(w, r)
 		} else {
 			// Forward request
 			in, _, err := c.Exchange(r, config.Forward.Server)