New data types net_addr and variants (in lib/net.h) describing
network addresses (prefix/pxlen). Modifications of FIB structures
to handle these data types and changing everything to use these
data types instead of prefix/pxlen pairs where possible.
The commit is WiP, some protocols are not yet updated (BGP, Kernel),
and the code contains some temporary scaffolding.
Comments are welcome.
The new RIP implementation fixes plenty of old bugs and also adds support
for many new features: ECMP support, link state support, BFD support,
configurable split horizon and more. Most options are now per-interface.
This is implemented in a way similar to lib/slists.h, but it took some
more effort to make rehashing not disturb the readers. We do it by just
taking _highest_ k bits of ipa_hash as our hash value and sorting each
box by whole ipa_hash().
Consult FIB_ITERATE_* macros in nest/route.h.
Implemented fib_check() debugging function and also rewrote the rehashing
algorithm to use better thresholds and not to waste time by rehashing
forth and back.
