chore: code cleanup

dns/util.go

@@ -306,7 +306,7 @@ func batchExchange(ctx context.Context, clients []dnsClient, m *D.Msg) (msg *D.M
 	domain := msgToDomain(m)
 	for _, client := range clients {
 		if _, isRCodeClient := client.(rcodeClient); isRCodeClient {
-			msg, err = client.Exchange(m)
+			msg, err = client.ExchangeContext(ctx, m)
 			return msg, false, err
 		}
 		client := client // shadow define client to ensure the value captured by the closure will not be changed in the next loop