Fix TCP Fast Open for the TCP RACK stack.

* Fix a bug where the SYN handling during established state was
applied to a front state.
* Move a check for retransmission after the timer handling.
Th

Fix TCP Fast Open for the TCP RACK stack.

* Fix a bug where the SYN handling during established state was
applied to a front state.
* Move a check for retransmission after the timer handling.
This was suppressing timer based retransmissions.
* Fix an off-by one byte in the sequence number of retransmissions.
* Apply fixes corresponding to
https://svnweb.freebsd.org/changeset/base/336934

Reviewed by: rrs@
Approved by: re (kib@)
MFC after: 1 month
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D16912

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Merge ^/head r338026 through r338297, and resolve conflicts.

This change represents a substantial restructure of the way we
reassembly inbound tcp segments. The old algorithm just blindly
dropped in segments without coalescing. This meant that every
segment co

This change represents a substantial restructure of the way we
reassembly inbound tcp segments. The old algorithm just blindly
dropped in segments without coalescing. This meant that every
segment could take up greater and greater room on the linked list
of segments. This of course is now subject to a tighter limit (100)
of segments which in a high BDP situation will cause us to be a
lot more in-efficent as we drop segments beyond 100 entries that
we receive. What this restructure does is cause the reassembly
buffer to coalesce segments putting an emphasis on the two
common cases (which avoid walking the list of segments) i.e.
where we add to the back of the queue of segments and where we
add to the front. We also have the reassembly buffer supporting
a couple of debug options (black box logging as well as counters
for code coverage). These are compiled out by default but can
be added by uncommenting the defines.

Sponsored by: Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D16626

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MFH @ r337607, in preparation for boarding

Merge ^/head r337286 through r337585.

Fix a small bug in rack where it will
end up sending the FIN twice.
Sponsored by: Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D16604

This fixes a bug in Rack where we were
not properly using the correct value for
Delayed Ack.

Sponsored by: Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D16579

Merge ^/head r336870 through r337285, and resolve conflicts.

This fixes a hole where rack could end up
sending an invalid segment into the reassembly
queue. This would happen if you enabled the
data after close option.

Sponsored by: Netflix
Differential Revis

This fixes a hole where rack could end up
sending an invalid segment into the reassembly
queue. This would happen if you enabled the
data after close option.

Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D16453

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Bump the ICMP echo limits to match the RFC

Reviewed by: tuexen
Sponsored by: Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D16333

Use appropriate MSS value when populating the TCP FO client cookie cache

When a client receives a SYN-ACK segment with a TFP fast open cookie,
but without an MSS option, an MSS value from uninitiali

Use appropriate MSS value when populating the TCP FO client cookie cache

When a client receives a SYN-ACK segment with a TFP fast open cookie,
but without an MSS option, an MSS value from uninitialised stack memory is used.
This patch ensures that in case no MSS option is included in the SYN-ACK,
the appropriate value as given in RFC 7413 is used.

Reviewed by: kbowling@
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D16175

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Allow alternate TCP stack to populate the TCP FO client cookie
cache.

Without this patch, TCP FO could be used when using alternate
TCP stack, but only existing entires in the TCP client cookie
cach

Allow alternate TCP stack to populate the TCP FO client cookie
cache.

Without this patch, TCP FO could be used when using alternate
TCP stack, but only existing entires in the TCP client cookie
cache could be used. This cache was not populated by connections
using alternate TCP stacks.

Sponsored by: Netflix, Inc.

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epoch(9): allow preemptible epochs to compose

- Add tracker argument to preemptible epochs
- Inline epoch read path in kernel and tied modules
- Change in_epoch to take an epoch as argument
- Simpli

epoch(9): allow preemptible epochs to compose

- Add tracker argument to preemptible epochs
- Inline epoch read path in kernel and tied modules
- Change in_epoch to take an epoch as argument
- Simplify tfb_tcp_do_segment to not take a ti_locked argument,
there's no longer any benefit to dropping the pcbinfo lock
and trying to do so just adds an error prone branchfest to
these functions
- Remove cases of same function recursion on the epoch as
recursing is no longer free.
- Remove the the TAILQ_ENTRY and epoch_section from struct
thread as the tracker field is now stack or heap allocated
as appropriate.

Tested by: pho and Limelight Networks
Reviewed by: kbowling at llnw dot com
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D16066

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Revert r334843, and partially revert r335180.

tcp_outflags[] were defined since 4BSD and are defined nowadays in
all its descendants. Removing them breaks third party application.

Make sure that the t_peakrate_thr is not compiled in
by default until NF can upstream it.

Reviewed by: and suggested lstewart
Sponsored by: Netflix Inc.

convert inpcbinfo hash and info rwlocks to epoch + mutex

- Convert inpcbinfo info & hash locks to epoch for read and mutex for write
- Garbage collect code that handled INP_INFO_TRY_RLOCK failures a

convert inpcbinfo hash and info rwlocks to epoch + mutex

- Convert inpcbinfo info & hash locks to epoch for read and mutex for write
- Garbage collect code that handled INP_INFO_TRY_RLOCK failures as
INP_INFO_RLOCK which can no longer fail

When running 64 netperfs sending minimal sized packets on a 2x8x2 reduces
unhalted core cycles samples in rwlock rlock/runlock in udp_send from 51% to
3%.

Overall packet throughput rate limited by CPU affinity and NIC driver design
choices.

On the receiver unhalted core cycles samples in in_pcblookup_hash went from
13% to to 1.6%

Tested by LLNW and pho@

Reviewed by: jtl
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D15686

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TCPOUTFLAGS no longer exists since r334843.

This fixes several bugs that Larry Rosenman helped me find in
Rack with respect to its handling of TCP Fast Open. Several
fixes all related to TFO are included in this commit:
1) Handling of non-TFO

This fixes several bugs that Larry Rosenman helped me find in
Rack with respect to its handling of TCP Fast Open. Several
fixes all related to TFO are included in this commit:
1) Handling of non-TFO retransmissions
2) Building the proper send-map when we are doing TFO
3) Dealing with the ack that comes back that includes the
SYN and data.

It appears that with this commit TFO now works :-)

Thanks Larry for all your help!!

Sponsored by: Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D15758

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Change RACK dependency on TCPHPTS from a build-time dependency to a load-
time dependency.

At present, RACK requires the TCPHPTS option to run. However, because
modules can be moved from machine to

Change RACK dependency on TCPHPTS from a build-time dependency to a load-
time dependency.

At present, RACK requires the TCPHPTS option to run. However, because
modules can be moved from machine to machine, this dependency is really
best assessed at load time rather than at build time.

Reviewed by: rrs
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D15756

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This commit brings in a new refactored TCP stack called Rack.
Rack includes the following features:
- A different SACK processing scheme (the old sack structures are not used).
- RACK (Recent ackno

This commit brings in a new refactored TCP stack called Rack.
Rack includes the following features:
- A different SACK processing scheme (the old sack structures are not used).
- RACK (Recent acknowledgment) where counting dup-acks is no longer done
instead time is used to knwo when to retransmit. (see the I-D)
- TLP (Tail Loss Probe) where we will probe for tail-losses to attempt
to try not to take a retransmit time-out. (see the I-D)
- Burst mitigation using TCPHTPS
- PRR (partial rate reduction) see the RFC.

Once built into your kernel, you can select this stack by either
socket option with the name of the stack is "rack" or by setting
the global sysctl so the default is rack.

Note that any connection that does not support SACK will be kicked
back to the "default" base FreeBSD stack (currently known as "default").

To build this into your kernel you will need to enable in your
kernel:
makeoptions WITH_EXTRA_TCP_STACKS=1
options TCPHPTS

Sponsored by: Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D15525

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