diff --git a/util.hpp b/util.hpp
index f9eb0e2..9c180ee 100644
--- a/util.hpp
+++ b/util.hpp
@@ -168,6 +168,15 @@
  */
 void executeCommandinChildProcess(const char* path, char** args);
 
+/** @brief Get ignored interfaces from environment */
+std::string getIgnoredInterfacesEnv();
+
+/** @brief Parse the comma separated interface names */
+std::set<std::string> parseInterfaces(const std::string& interfaces);
+
+/** @brief Get the ignored interfaces */
+const std::set<std::string>& getIgnoredInterfaces();
+
 } // namespace internal
 
 /* @brief runs the given command in child process.