[net] Search for net subsystem rust abstractions in-progress

Hi,

I am following up on some advice given from the Rust forums where I am
trying to move some of my LKM's from C to Rust. These LKM's,basically
create new address family protocols using (for starters) structs and
functions like the following:

    struct net_proto_family;
    struct proto_ops;

    // Add a socket protocol handler
    err = sock_register(&proto_family);

These do not appear in the kernel crate. Per the
submitting-new-abstractions-and-modules section for contributions in
rust-for-linux, the second bullet point says to "check the mailing
list archive" because "part of the work may be already done or in the
process of being upstreamed", so I was hoping to see where things
stand and get advice.

I know the goals are not to duplicate or rewrite existing drivers, but
my modules have not been opened up yet and still going through heavy
development. I guess I am looking to know if there are proper API's or
abstractions for the net subsystem, otherwise, I may want to start
looking into contributing. It is also my understanding that we would
not want to be directly using any C bindings, rather, using a Rust
abstractions layer.

Thank you for any advice.