The tcp_ratelimit code is a bit behind, we have found many issues in
working with Mellanox cards. Some of them are due to the fact
that TLS and Ratelimit uses tags, this makes it so we have to be able
to wind down to the right tag and thus the new methods in the if_var.
There were other issues with the epoch handling in the tcp_ratelimit.c code
that could cause us to have issues when we used it. The interface also needs
tweaking to clear the pathway for the widespread use of ratelimiting in rack (which
will be a follow on commit).
Note to Hans, I have all the commits here but if you would like me to pull out the
changes in the mlx driver and commit them separately that would be fine, just let