IP and port associated with a socket fd

[Zubin Mithra]

Hi Mike,

>
> i don't think we want to use that model.  the /proc net filesystem is known to
> have limitations.  instead i think we should do what iproute2's ss tool does
> -- use netlink sockets.

Looks interesting, I'll change the current implementation to use
netlink sockets. Thank you!

-- zm