Commit Graph

4 Commits

Author SHA1 Message Date
Michael Tuexen
12a43d0d5d RFC 7112 requires a host to put the complete IP header chain
including the TCP header in the first IP packet.
Enforce this in tcp_output(). In addition make sure that at least
one byte payload fits in the TCP segement to allow making progress.
Without this check, a kernel with INVARIANTS will panic.
This issue was found by running an instance of syzkaller.

Reviewed by:		jtl@
MFC after:		3 days
Sponsored by:		Netflix, Inc.
Differential Revision:	https://reviews.freebsd.org/D21665
2019-09-29 10:45:13 +00:00
Randall Stewart
ac7bd23a7a lets put (void) in a couple of functions to keep older platforms that
are stuck with gcc happy (ppc). The changes are needed in both bbr and
rack.

Obtained from:	Michael Tuexen (mtuexen@)
2019-09-24 20:36:43 +00:00
Randall Stewart
da99b33b17 don't call in_ratelmit detach when RATELIMIT is not
compiled in the kernel.
2019-09-24 20:11:55 +00:00
Randall Stewart
35c7bb3407 This commit adds BBR (Bottleneck Bandwidth and RTT) congestion control. This
is a completely separate TCP stack (tcp_bbr.ko) that will be built only if
you add the make options WITH_EXTRA_TCP_STACKS=1 and also include the option
TCPHPTS. You can also include the RATELIMIT option if you have a NIC interface that
supports hardware pacing, BBR understands how to use such a feature.

Note that this commit also adds in a general purpose time-filter which
allows you to have a min-filter or max-filter. A filter allows you to
have a low (or high) value for some period of time and degrade slowly
to another value has time passes. You can find out the details of
BBR by looking at the original paper at:

https://queue.acm.org/detail.cfm?id=3022184

or consult many other web resources you can find on the web
referenced by "BBR congestion control". It should be noted that
BBRv1 (which this is) does tend to unfairness in cases of small
buffered paths, and it will usually get less bandwidth in the case
of large BDP paths(when competing with new-reno or cubic flows). BBR
is still an active research area and we do plan on  implementing V2
of BBR to see if it is an improvement over V1.

Sponsored by:	Netflix Inc.
Differential Revision:	https://reviews.freebsd.org/D21582
2019-09-24 18:18:11 +00:00