Modular TCP .. or the start..

[Randall Stewart]

All:

As promised I managed to get working this afternoon a modular transport much on the
lines of what we have talked about.

The review of it is here:

https://reviews.freebsd.org/D4055

There are still things left un-done .. but its a first step that covers quite a bit
and I also supply a KLM called fastpath that shows how it can be used and adds
two different fast-path approaches we have tried at Netflix (we may be moving completely
to the fastack version).

There is also a utility included in usr.sbin that allows you to list and manipulate whats
in the system (i.e. see the default, set the default, show all entries). An individual
socket can also set its own TCP function set at open (but not after it has moved to
some other state).

There are a few things missing that Jonathan wanted in particular I did *not* do
tcp_input()
or
pru_usrreq()

These would involve a lot more work in the in_pcb and I did not want to tackle that yet… it can
be something we add later.. there is enough here that I think a lot can be done to play with
new tcp stacks and alternate designs :-)

Please look and make comments, the usual suspects on the transport review are named as reviewers

Best wishes

R
--------
Randall Stewart
rrs at netflix.com
803-317-4952