This contains private/internal helpers that depend on the public libnl-3 (core) and libnl-route-3.
Itself, it must only rely on C, include/base/ and public headers of libnl-3 (core) and libnl-route-3.
They can be used by all internal code that uses the public API of both libnl-3 (core) and libnl-route-3.
It can also be used by lib/route itself (that is, the implementation of libnl-route-3).
It must not be used in public headers, it's internal only.
Currently this is header-only, it does not require any additional linking.