Merge pull request #202 in DNS/adguard-dns from fix/647 to master

* commit '528c1a72cac331f08de5fdee4538529c70dff1bb':
  - use 127.0.0.1 as a resolver address when DNS binding address is 0.0.0.0
  - app: don't print filter update error messages on first launch before  DNS server is set up

dns.go

@@ -50,7 +50,11 @@ func generateServerConfig() dnsforward.ServerConfig {
 		FilteringConfig: config.DNS.FilteringConfig,
 		Filters:         filters,
 	}
-	newconfig.ResolverAddress = fmt.Sprintf("%s:%d", config.DNS.BindHost, config.DNS.Port)
+	bindhost := config.DNS.BindHost
+	if config.DNS.BindHost == "0.0.0.0" {
+		bindhost = "127.0.0.1"
+	}
+	newconfig.ResolverAddress = fmt.Sprintf("%s:%d", bindhost, config.DNS.Port)
 
 	if config.TLS.Enabled {
 		newconfig.TLSConfig = config.TLS.TLSConfig

filter.go

@@ -178,6 +178,10 @@ func periodicallyRefreshFilters() {
 func refreshFiltersIfNecessary(force bool) int {
 	var updateFilters []filter
 
+	if config.firstRun {
+		return 0
+	}
+
 	config.RLock()
 	for i := range config.Filters {
 		f := &config.Filters[i] // otherwise we will be operating on a copy

helpers.go

@@ -323,7 +323,11 @@ func customDialContext(ctx context.Context, network, addr string) (net.Conn, err
 		return con, err
 	}
 
-	resolverAddr := fmt.Sprintf("%s:%d", config.DNS.BindHost, config.DNS.Port)
+	bindhost := config.DNS.BindHost
+	if config.DNS.BindHost == "0.0.0.0" {
+		bindhost = "127.0.0.1"
+	}
+	resolverAddr := fmt.Sprintf("%s:%d", bindhost, config.DNS.Port)
 	r := upstream.NewResolver(resolverAddr, 30*time.Second)
 	addrs, e := r.LookupIPAddr(ctx, host)
 	log.Tracef("LookupIPAddr: %s: %v", host, addrs)