Refactoring for set upstream and bootstrap DNS

control.go

@@ -323,44 +323,94 @@ func sortByValue(m map[string]int) []string {
 // -----------------------
 
 func handleSetUpstreamDNS(w http.ResponseWriter, r *http.Request) {
+	setDNSServers(&w, r, true)
+}
+
+func handleSetBootstrapDNS(w http.ResponseWriter, r *http.Request) {
+	setDNSServers(&w, r, false)
+}
+
+// setDNSServers sets upstream and bootstrap DNS servers
+func setDNSServers(w *http.ResponseWriter, r *http.Request, upstreams bool) {
 	body, err := ioutil.ReadAll(r.Body)
 	if err != nil {
 		errorText := fmt.Sprintf("Failed to read request body: %s", err)
 		log.Println(errorText)
-		http.Error(w, errorText, http.StatusBadRequest)
+		http.Error(*w, errorText, http.StatusBadRequest)
 		return
 	}
 	// if empty body -- user is asking for default servers
 	hosts := strings.Fields(string(body))
 
-	if len(hosts) == 0 {
+	// bootstrap servers are plain DNS only. We should remove tls:// https:// and sdns:// hosts from slice
-		config.DNS.UpstreamDNS = defaultDNS
+	bootstraps := []string{}
+	if !upstreams && len(hosts) > 0 {
+		for _, host := range hosts {
+			err = checkBootstrapDNS(host)
+			if err != nil {
+				log.Tracef("%s can not be used as bootstrap DNS cause: %s", host, err)
+				continue
+			}
+			hosts = append(bootstraps, host)
+		}
+	}
+
+	// count of upstream or bootstrap servers
+	var count int
+	if upstreams {
+		count = len(hosts)
 	} else {
-		config.DNS.UpstreamDNS = hosts
+		count = len(bootstraps)
+	}
+
+	if upstreams {
+		if count == 0 {
+			config.DNS.UpstreamDNS = defaultDNS
+		} else {
+			config.DNS.UpstreamDNS = hosts
+		}
+	} else {
+		if count == 0 {
+			config.DNS.BootstrapDNS = defaultBootstrap
+		} else {
+			config.DNS.BootstrapDNS = bootstraps
+		}
 	}
 
 	err = writeAllConfigs()
 	if err != nil {
 		errorText := fmt.Sprintf("Couldn't write config file: %s", err)
 		log.Println(errorText)
-		http.Error(w, errorText, http.StatusInternalServerError)
+		http.Error(*w, errorText, http.StatusInternalServerError)
 		return
 	}
 	err = reconfigureDNSServer()
 	if err != nil {
 		errorText := fmt.Sprintf("Couldn't reconfigure the DNS server: %s", err)
 		log.Println(errorText)
-		http.Error(w, errorText, http.StatusInternalServerError)
+		http.Error(*w, errorText, http.StatusInternalServerError)
 		return
 	}
-	_, err = fmt.Fprintf(w, "OK %d servers\n", len(hosts))
+
+	_, err = fmt.Fprintf(*w, "OK %d servers\n", count)
 	if err != nil {
 		errorText := fmt.Sprintf("Couldn't write body: %s", err)
 		log.Println(errorText)
-		http.Error(w, errorText, http.StatusInternalServerError)
+		http.Error(*w, errorText, http.StatusInternalServerError)
 	}
 }
 
+func checkBootstrapDNS(host string) error {
+	// Check if host is ip without port
+	if net.ParseIP(host) != nil {
+		return nil
+	}
+
+	// Check if host is ip with port
+	_, _, err := net.SplitHostPort(host)
+	return err
+}
+
 func handleTestUpstreamDNS(w http.ResponseWriter, r *http.Request) {
 	body, err := ioutil.ReadAll(r.Body)
 	if err != nil {
@@ -437,45 +487,6 @@ func checkDNS(input string) error {
 	return nil
 }
 
-func handleSetBootstrapDNS(w http.ResponseWriter, r *http.Request) {
-	body, err := ioutil.ReadAll(r.Body)
-	if err != nil {
-		errorText := fmt.Sprintf("Failed to read request body: %s", err)
-		log.Println(errorText)
-		http.Error(w, errorText, http.StatusBadRequest)
-		return
-	}
-	// if empty body -- user is asking for default servers
-	hosts := strings.Fields(string(body))
-
-	if len(hosts) == 0 {
-		config.DNS.BootstrapDNS = defaultBootstrap
-	} else {
-		config.DNS.BootstrapDNS = hosts
-	}
-
-	err = writeAllConfigs()
-	if err != nil {
-		errorText := fmt.Sprintf("Couldn't write config file: %s", err)
-		log.Println(errorText)
-		http.Error(w, errorText, http.StatusInternalServerError)
-		return
-	}
-	err = reconfigureDNSServer()
-	if err != nil {
-		errorText := fmt.Sprintf("Couldn't reconfigure the DNS server: %s", err)
-		log.Println(errorText)
-		http.Error(w, errorText, http.StatusInternalServerError)
-		return
-	}
-	_, err = fmt.Fprintf(w, "OK %d bootsrap servers\n", len(hosts))
-	if err != nil {
-		errorText := fmt.Sprintf("Couldn't write body: %s", err)
-		log.Println(errorText)
-		http.Error(w, errorText, http.StatusInternalServerError)
-	}
-}
-
 func handleGetVersionJSON(w http.ResponseWriter, r *http.Request) {
 	now := time.Now()
 	if now.Sub(versionCheckLastTime) <= versionCheckPeriod && len(versionCheckJSON) != 0 {