added comments

blacklist.go

@@ -69,6 +69,7 @@ func getBlacklistFromURL(url string) (*string, error) {
 	return &bodyString, err
 }
 
+// parseRawBlacklist parse the raw string depending on the given format
 func parseRawBlacklist(blacklist configBlacklist, raw string) []string {
 	switch blacklist.Format {
 	case "host":
@@ -82,6 +83,7 @@ func parseRawBlacklist(blacklist configBlacklist, raw string) []string {
 	}
 }
 
+// parseHostFormat parse the string in the format of a hostfile
 func parseHostFormat(raw string) []string {
 	finalList := make([]string, 0)
 	reg := regexp.MustCompile(`(?mi)^\s*(#*)\s*(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})\s+([a-zA-Z0-9\.\- ]+)$`)
@@ -95,6 +97,7 @@ func parseHostFormat(raw string) []string {
 	return finalList
 }
 
+// parseLineFormat one domain per line, ignore comments
 func parseLineFormat(raw string) []string {
 	list := make([]string, 0)
 
@@ -113,6 +116,7 @@ func handleBlockedDomain(w dns.ResponseWriter, r *dns.Msg) {
 	m := new(dns.Msg)
 	m.SetReply(r)
 	if q.Qtype == dns.TypeA {
+		// Respond with 0.0.0.0
 		m.Answer = append(m.Answer, &dns.A{
 			Hdr: dns.RR_Header{
 				Name:   q.Name,
@@ -123,6 +127,7 @@ func handleBlockedDomain(w dns.ResponseWriter, r *dns.Msg) {
 			A: nullIPv4,
 		})
 	} else if q.Qtype == dns.TypeAAAA {
+		// Respond with ::/0
 		m.Answer = append(m.Answer, &dns.AAAA{
 			Hdr: dns.RR_Header{
 				Name:   q.Name,

coolDns.go

@@ -23,6 +23,7 @@ type zoneMap map[string][]zoneView
 
 type rrMap map[uint16]map[string][]dns.RR
 
+// config format of the config file
 type config struct {
 	Zones     []configZone      `yaml:"zones"`
 	ACL       []configACL       `yaml:"acl"`
@@ -60,6 +61,7 @@ type configTLS struct {
 	Key     string `yaml:"key"`
 }
 
+// All record types to send when a ANY request is send
 var anyRecordTypes = []uint16{
 	dns.TypeSOA,
 	dns.TypeA,
@@ -109,6 +111,7 @@ func loadZones(configZones []configZone) (zoneMap, error) {
 	return zones, nil
 }
 
+// createRRMap order the rr into a structure that is more easy to use
 func createRRMap(rrs []dns.RR) rrMap {
 	rrMap := make(rrMap)
 	for _, rr := range rrs {
@@ -147,6 +150,7 @@ func loadZonefile(filepath, origin string) ([]dns.RR, error) {
 	return rrs, nil
 }
 
+// createACLList create a map with the CIDR and the name of the rule
 func createACLList(config []configACL) (map[string]*net.IPNet, error) {
 	acls := make(map[string]*net.IPNet)
 
@@ -163,10 +167,12 @@ func createACLList(config []configACL) (map[string]*net.IPNet, error) {
 	return acls, nil
 }
 
+// createServer creates a new serve mux. Adds all the logic to handle the request
 func createServer(zones zoneMap, config config, aclList map[string]*net.IPNet, blacklist map[string]bool) *dns.ServeMux {
 	srv := dns.NewServeMux()
 	c := new(dns.Client)
 
+	// For all zones set from the config
 	for zoneName, zones := range zones {
 		srv.HandleFunc(zoneName, func(w dns.ResponseWriter, r *dns.Msg) {
 
@@ -187,6 +193,7 @@ func createServer(zones zoneMap, config config, aclList map[string]*net.IPNet, b
 				}
 			}
 
+			// No view found that can handle the request
 			if zoneIndex == -1 {
 				rcodeRequest(w, r, dns.RcodeRefused)
 				return
@@ -196,8 +203,10 @@ func createServer(zones zoneMap, config config, aclList map[string]*net.IPNet, b
 		})
 	}
 
-	// Handle any other request
+	// Handle any other request for forwarding
 	srv.HandleFunc(".", func(w dns.ResponseWriter, r *dns.Msg) {
+
+		// Parse IP
 		remoteIP, _, err := net.SplitHostPort(w.RemoteAddr().String())
 		ip := net.ParseIP(remoteIP)
 
@@ -212,6 +221,7 @@ func createServer(zones zoneMap, config config, aclList map[string]*net.IPNet, b
 			return
 		}
 
+		// Check if the domain is bocked
 		if _, ok := blacklist[r.Question[0].Name]; ok {
 			handleBlockedDomain(w, r)
 		} else {
@@ -222,21 +232,23 @@ func createServer(zones zoneMap, config config, aclList map[string]*net.IPNet, b
 				rcodeRequest(w, r, dns.RcodeServerFailure)
 				return
 			}
+
 			w.WriteMsg(in)
 		}
-
 	})
 
 	return srv
 }
 
 func listenAndServer(server *dns.ServeMux, address string) {
+	// Start UDP listner
 	go func() {
 		if err := dns.ListenAndServe(address, "udp", server); err != nil {
 			log.Fatalf("Failed to set udp listener %s\n", err.Error())
 		}
 	}()
 
+	// Start TCP listner
 	go func() {
 		if err := dns.ListenAndServe(address, "tcp", server); err != nil {
 			log.Fatalf("Failed to set tcp listener %s\n", err.Error())
@@ -245,6 +257,7 @@ func listenAndServer(server *dns.ServeMux, address string) {
 }
 
 func listenAndServerTLS(server *dns.ServeMux, address, cert, key string) {
+	// Start TLS listner
 	go func() {
 		if err := dns.ListenAndServeTLS(address, cert, key, server); err != nil {
 			log.Fatalf("Failed to set DoT listener %s", err.Error())
@@ -266,6 +279,7 @@ func checkACL(alcRules []string, aclList map[string]*net.IPNet, ip net.IP) bool
 	return true
 }
 
+// rcodeRequest respond to a request with a response code
 func rcodeRequest(w dns.ResponseWriter, r *dns.Msg, rcode int) {
 	m := new(dns.Msg)
 	m.SetReply(r)
@@ -273,6 +287,7 @@ func rcodeRequest(w dns.ResponseWriter, r *dns.Msg, rcode int) {
 	w.WriteMsg(m)
 }
 
+// handleRequest find the right RR(s) in the view and send them back
 func handleRequest(w dns.ResponseWriter, r *dns.Msg, zone zoneView) {
 	m := new(dns.Msg)
 	m.SetReply(r)