tcp: Use segment size excluding tcp options for all cwnd calculations

Avoid sending small segments by making sure that cwnd is usually
calculated in full (data) segment sizes. Especially during loss

tcp: Use segment size excluding tcp options for all cwnd calculations

Avoid sending small segments by making sure that cwnd is usually
calculated in full (data) segment sizes. Especially during loss
recovery and retransmission scenarios.

Reviewed By: tuexen, #transport
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D47474

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cc_cubic: use newreno to emulate AIMD in TCP-friendly region

Reviewed by: rscheff, tuexen
Differential Revision: https://reviews.freebsd.org/D46546

tcp cc: remove non-working sctp support

As suggested by lstewart, remove the non-working SCTP support in the
TCP congestion control modules. SCTP has a similar functionality
(although not using kern

tcp cc: remove non-working sctp support

As suggested by lstewart, remove the non-working SCTP support in the
TCP congestion control modules. SCTP has a similar functionality
(although not using kernel loadable modules), on which the TCP stuff
was built on, but the integration was never done.
No functional change intended.

Reviewed by: Peter Lei, cc
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D46142

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cc_cubic: remove the redundant variable num_cong_events from struct cubic.

Summary:
This variable was added by commit eb5bfdd06565, but unnecessarily needed.
No functional change.

Reviewed by: tuex

cc_cubic: remove the redundant variable num_cong_events from struct cubic.

Summary:
This variable was added by commit eb5bfdd06565, but unnecessarily needed.
No functional change.

Reviewed by: tuexen

Differential Revision: https://reviews.freebsd.org/D46042

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tcp: cubic - restart epoch after RTO

This is a migitation to avoid sudden extreme jumps in
cwnd, as t_epoch can be very out of date after an RTO.
Per RFC9438, sec 4.8, t_epoch is to be reset wheneve

tcp: cubic - restart epoch after RTO

This is a migitation to avoid sudden extreme jumps in
cwnd, as t_epoch can be very out of date after an RTO.
Per RFC9438, sec 4.8, t_epoch is to be reset whenever
cwnd grows beyond ssthresh (CC phase transitions from
slow start to congestion avoidance), to be fixed with
the upcoming cc_cubic changes.

MFC after: 3 days
Reviewed By: cc, #transport
Sponsored by: NetApp, Inc
Differential Revision: https://reviews.freebsd.org/D44023

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tcp: use enum for all congestion control signals

Facilitate easier troubleshooting by enumerating
all congestion control signals. Typecast the
enum to int, when a congestion control module uses
priv

tcp: use enum for all congestion control signals

Facilitate easier troubleshooting by enumerating
all congestion control signals. Typecast the
enum to int, when a congestion control module uses
private signals.

No external change.

Reviewed By: glebius, tuexen, #transport
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D43838

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tcp: fix RTO ssthresh for non-6675 pipe calculation

Follow up on D43768 to properly deal with the non-default
pipe calculation. When CC_RTO is processed, the timeout
will have already pulled back sn

tcp: fix RTO ssthresh for non-6675 pipe calculation

Follow up on D43768 to properly deal with the non-default
pipe calculation. When CC_RTO is processed, the timeout
will have already pulled back snd_nxt. Further, snd_fack
is not pulled along with snd_una.

Reviewed By: tuexen, #transport
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D43876

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tcp: calculate ssthresh on RTO according to RFC5681

per RFC5681, only adjust ssthresh on the initital
retransmission timeout. Since RTO often happens
during loss recovery, while cwnd no longer track

tcp: calculate ssthresh on RTO according to RFC5681

per RFC5681, only adjust ssthresh on the initital
retransmission timeout. Since RTO often happens
during loss recovery, while cwnd no longer tracks
all data in flight, calculcate pipe properly.

Reviewed By: tuexen, #transport
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D43768

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tcp: use tcp_fixed_maxseg instead of tcp_maxseg in cc modules

tcp_fixed_maxseg() is the streamlined calculation of typical
tcp options and more suitable for heavy use in the congestion
control modul

tcp: use tcp_fixed_maxseg instead of tcp_maxseg in cc modules

tcp_fixed_maxseg() is the streamlined calculation of typical
tcp options and more suitable for heavy use in the congestion
control modules on every received packet.

No external functional change.

Reviewed By: tuexen, #transport
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D43779

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sys: Automated cleanup of cdefs and other formatting

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remov

sys: Automated cleanup of cdefs and other formatting

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/

Sponsored by: Netflix

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sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

tcp: Add and update cubic module variable names

Prepare the cubic congestion control module to better align with
the specifications in RFC8312bis.

Rename a few cubic state variables to the variable

tcp: Add and update cubic module variable names

Prepare the cubic congestion control module to better align with
the specifications in RFC8312bis.

Rename a few cubic state variables to the variable names found in
the RFC8312bis specification. This makes the code more understandable
for someone reading the RFC and the code. It also makes the variable
naming convention more uniform. Add some variables needed subsequently.

No functional change.

Submitted By: Bhaskar Pardeshi, VMware Inc.
Reviewed By: tuexen, #transport
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D40436

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cc_cubic: Use units of micro seconds (usecs) instead of ticks in rtt.

This improves TCP friendly cwnd in cases of low latency high drop rate
networks. Tests show +42% and +37% better performance in

cc_cubic: Use units of micro seconds (usecs) instead of ticks in rtt.

This improves TCP friendly cwnd in cases of low latency high drop rate
networks. Tests show +42% and +37% better performance in 1Gpbs and 10Gbps
cases.

Reported by: Bhaskar Pardeshi from VMware.
Reviewed By: rscheff, tuexen
Approved by: rscheff (mentor), tuexen (mentor)

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There are congestion control algorithms will that pull in srtt, and this can cause issues with rack.

When using rack, cubic and htcp will grab the srtt, but they think it is in ticks. For rack
it is

There are congestion control algorithms will that pull in srtt, and this can cause issues with rack.

When using rack, cubic and htcp will grab the srtt, but they think it is in ticks. For rack
it is in micro-seconds (which we should probably move all stacks to actually). This causes
issues so instead lets make a new interface so that any CC module can pull the srtt in
whatever granularity they want.

Reviewed by: tuexen
Sponsored by: Netflix Inc
Differential Revision:https://reviews.freebsd.org/D40146

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spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

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Move access to tcp's t_logstate into inline functions and provide new tracepoint and bbpoint capabilities.

The TCP stacks have long accessed t_logstate directly, but in order to do tracepoints and t

Move access to tcp's t_logstate into inline functions and provide new tracepoint and bbpoint capabilities.

The TCP stacks have long accessed t_logstate directly, but in order to do tracepoints and the new bbpoints
we need to move to using the new inline functions. This adds them and moves rack to now use
the tcp_tracepoints.

Reviewed by: tuexen, gallatin
Sponsored by: Netflix Inc
Differential Revision: https://reviews.freebsd.org/D38831

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tcp: provide macros to access inpcb and socket from a tcpcb

There should be no functional changes with this commit.

Reviewed by: rscheff
Differential revision: https://reviews.freebsd.org/D37123

tcp: Make all references to CUBIC uppercase

Consistently refer to the CUBIC congestion control
mechanism in uppercase throughout all comments.

No functional change.

Reviewed By: #transport, tuexen

tcp: Make all references to CUBIC uppercase

Consistently refer to the CUBIC congestion control
mechanism in uppercase throughout all comments.

No functional change.

Reviewed By: #transport, tuexen, mav, guest-ccui, emaste
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D36547

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Opps sorry, typo in the cc_cubic fix when morphing it from nreno.

hystart++ may not properly exit CSS back to slowstart.

In the changes to get hystart++ into cubic an inadvertent line
was removed in the conditional to figure out if you need to exit
hystart++ back

hystart++ may not properly exit CSS back to slowstart.

In the changes to get hystart++ into cubic an inadvertent line
was removed in the conditional to figure out if you need to exit
hystart++ back to slowstart. The line of course is the most crucial
one (the others are valid but not critical) i.e. is the new rtt
less than the point where we entered hystart++. Without the line
we end up bouncing in and out of CSS.

Reported By: Reese Enghardt
Sponsored By: Netflix Inc.

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tcp: Add hystart++ to our cubic implementation.

As promised to the transport call on 11/4/22 here is an implementation
of hystart++ for cubic. It also cleans up the tcp_congestion function
to have a

tcp: Add hystart++ to our cubic implementation.

As promised to the transport call on 11/4/22 here is an implementation
of hystart++ for cubic. It also cleans up the tcp_congestion function
to have a better name. Common variables are moved into the general
cc.h structure so that both cubic and newreno can use them for
hystart++

Reviewed by: Michael Tuexen, Richard Scheffenegger
Sponsored by: Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D33035

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tcp: Congestion control cleanup.

NOTE: HEADS UP read the note below if your kernel config is not including GENERIC!!

This patch does a bit of cleanup on TCP congestion control modules. There were s

tcp: Congestion control cleanup.

NOTE: HEADS UP read the note below if your kernel config is not including GENERIC!!

This patch does a bit of cleanup on TCP congestion control modules. There were some rather
interesting surprises that one could get i.e. where you use a socket option to change
from one CC (say cc_cubic) to another CC (say cc_vegas) and you could in theory get
a memory failure and end up on cc_newreno. This is not what one would expect. The
new code fixes this by requiring a cc_data_sz() function so we can malloc with M_WAITOK
and pass in to the init function preallocated memory. The CC init is expected in this
case *not* to fail but if it does and a module does break the
"no fail with memory given" contract we do fall back to the CC that was in place at the time.

This also fixes up a set of common newreno utilities that can be shared amongst other
CC modules instead of the other CC modules reaching into newreno and executing
what they think is a "common and understood" function. Lets put these functions in
cc.c and that way we have a common place that is easily findable by future developers or
bug fixers. This also allows newreno to evolve and grow support for its features i.e. ABE
and HYSTART++ without having to dance through hoops for other CC modules, instead
both newreno and the other modules just call into the common functions if they desire
that behavior or roll there own if that makes more sense.

Note: This commit changes the kernel configuration!! If you are not using GENERIC in
some form you must add a CC module option (one of CC_NEWRENO, CC_VEGAS, CC_CUBIC,
CC_CDG, CC_CHD, CC_DCTCP, CC_HTCP, CC_HD). You can have more than one defined
as well if you desire. Note that if you create a kernel configuration that does not
define a congestion control module and includes INET or INET6 the kernel compile will
break. Also you need to define a default, generic adds 'options CC_DEFAULT=\"newreno\"
but you can specify any string that represents the name of the CC module (same names
that show up in the CC module list under net.inet.tcp.cc). If you fail to add the
options CC_DEFAULT in your kernel configuration the kernel build will also break.

Reviewed by: Michael Tuexen
Sponsored by: Netflix Inc.
RELNOTES:YES
Differential Revision: https://reviews.freebsd.org/D32693

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tcp: Rename rfc6675_pipe to sack.revised, and enable by default

As full support of RFC6675 is in place, deprecating
net.inet.tcp.rfc6675_pipe and enabling by default
net.inet.tcp.sack.revised.

Revi

tcp: Rename rfc6675_pipe to sack.revised, and enable by default

As full support of RFC6675 is in place, deprecating
net.inet.tcp.rfc6675_pipe and enabling by default
net.inet.tcp.sack.revised.

Reviewed By: #transport, kbowling, rrs
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D28702

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TCP Cubic: improve reaction to (and rollback from) RTO

1. fix compliancy issue of CUBIC RTO handling according to RFC8312 section 4.7
2. add CUBIC CC_RTO_ERR handling

Submitted by: chengc_netapp.co

TCP Cubic: improve reaction to (and rollback from) RTO

1. fix compliancy issue of CUBIC RTO handling according to RFC8312 section 4.7
2. add CUBIC CC_RTO_ERR handling

Submitted by: chengc_netapp.com
Reviewed by: rrs, tuexen, rscheff
MFC after: 2 weeks
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D26808

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tcp: move cwnd and ssthresh updates into cc modules

This will pave the way of setting ssthresh differently in TCP CUBIC, according
to RFC8312 section 4.7.

No functional change, only code movement.

tcp: move cwnd and ssthresh updates into cc modules

This will pave the way of setting ssthresh differently in TCP CUBIC, according
to RFC8312 section 4.7.

No functional change, only code movement.

Submitted by: chengc_netapp.com
Reviewed by: rrs, tuexen, rscheff
MFC after: 2 weeks
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D26807

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