MFH

Sponsored by: Rubicon Communications, LLC (netgate.com)

Add MODULE_VERSION to TCP loadable congestion control modules.

Without versioning information, using preexisting loader /
linker code is not easily possible when another module may
have dependencies

Add MODULE_VERSION to TCP loadable congestion control modules.

Without versioning information, using preexisting loader /
linker code is not easily possible when another module may
have dependencies on pre-loaded modules, and also doesn't
allow the automatic loading of dependent modules.

No functional change of the actual modules.

Reviewed by: tuexen (mentor), rgrimes (mentor)
Approved by: tuexen (mentor), rgrimes (mentor)
MFC after: 2 weeks
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D25744

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Merge ^/head r358269 through r358399.

Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many)

r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly mark

Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many)

r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly marked).
Use it in preparation for a general review of all nodes.

This is non-functional change that adds annotations to SYSCTL_NODE and
SYSCTL_PROC nodes using one of the soon-to-be-required flags.

Mark all obvious cases as MPSAFE. All entries that haven't been marked
as MPSAFE before are by default marked as NEEDGIANT

Approved by: kib (mentor, blanket)
Commented by: kib, gallatin, melifaro
Differential Revision: https://reviews.freebsd.org/D23718

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MFHead @347527

Sponsored by: The FreeBSD Foundation

Prevent cwnd to collapse down to 1 MSS after exiting recovery.

This is descrined in RFC 6582, which updates RFC 3782.

Submitted by: Richard Scheffenegger
Reviewed by: lstewart@
MFC after: 1 week

Prevent cwnd to collapse down to 1 MSS after exiting recovery.

This is descrined in RFC 6582, which updates RFC 3782.

Submitted by: Richard Scheffenegger
Reviewed by: lstewart@
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D17614

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Merge ^/head r343320 through r343570.

Fix a bug in the restart window computation of TCP New Reno

When implementing support for IW10, an update in the computation
of the restart window used after an idle phase was missed. To
minimize co

Fix a bug in the restart window computation of TCP New Reno

When implementing support for IW10, an update in the computation
of the restart window used after an idle phase was missed. To
minimize code duplication, implement the logic in tcp_compute_initwnd()
and call it. This fixes a bug in NewReno, which was not aware of
IW10.

Submitted by: Richard Scheffenegger
Reviewed by: tuexen@
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D18940

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Fix bugs in plugable CC algorithm and siftr sysctls.

Use the sysctl_handle_int() handler to write out the old value and read
the new value into a temporary variable. Use the temporary variable
for a

Fix bugs in plugable CC algorithm and siftr sysctls.

Use the sysctl_handle_int() handler to write out the old value and read
the new value into a temporary variable. Use the temporary variable
for any checks of values rather than using the CAST_PTR_INT() macro on
req->newptr. The prior usage read directly from userspace memory if the
sysctl() was called correctly. This is unsafe and doesn't work at all on
some architectures (at least i386.)

In some cases, the code could also be tricked into reading from kernel
memory and leaking limited information about the contents or crashing
the system. This was true for CDG, newreno, and siftr on all platforms
and true for i386 in all cases. The impact of this bug is largest in
VIMAGE jails which have been configured to allow writing to these
sysctls.

Per discussion with the security officer, we will not be issuing an
advisory for this issue as root access and a non-default config are
required to be impacted.

Reviewed by: markj, bz
Discussed with: gordon (security officer)
MFC after: 3 days
Security: kernel information leak, local DoS (both require root)
Differential Revision: https://reviews.freebsd.org/D18443

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MFH @ r337607, in preparation for boarding

Use the new VNET_DEFINE_STATIC macro when we are defining static VNET
variables.

Reviewed by: bz
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D16147

NULL out cc_data in pluggable TCP {cc}_cb_destroy

When ABE was added (rS331214) to NewReno and leak fixed (rS333699) , it now has
a destructor (newreno_cb_destroy) for per connection state. Other co

NULL out cc_data in pluggable TCP {cc}_cb_destroy

When ABE was added (rS331214) to NewReno and leak fixed (rS333699) , it now has
a destructor (newreno_cb_destroy) for per connection state. Other congestion
controls may allocate and free cc_data on entry and exit, but the field is
never explicitly NULLed if moving back to NewReno which only internally
allocates stateful data (no entry contstructor) resulting in a situation where
newreno_cb_destory might be called on a junk pointer.

- NULL out cc_data in the framework after calling {cc}_cb_destroy
- free(9) checks for NULL so there is no need to perform not NULL checks
before calling free.
- Improve a comment about NewReno in tcp_ccalgounload

This is the result of a debugging session from Jason Wolfe, Jason Eggleston,
and mmacy@ and very helpful insight from lstewart@.

Submitted by: Kevin Bowling
Reviewed by: lstewart
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D16282

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Plug a memory leak and potential NULL-pointer dereference introduced in r331214.

Each TCP connection that uses the system default cc_newreno(4) congestion
control algorithm module leaks a "struct ne

Plug a memory leak and potential NULL-pointer dereference introduced in r331214.

Each TCP connection that uses the system default cc_newreno(4) congestion
control algorithm module leaks a "struct newreno" (8 bytes of memory) at
connection initialisation time. The NULL-pointer dereference is only germane
when using the ABE feature, which is disabled by default.

While at it:

- Defer the allocation of memory until it is actually needed given that ABE is
optional and disabled by default.

- Document the ENOMEM errno in getsockopt(2)/setsockopt(2).

- Document ENOMEM and ENOBUFS in tcp(4) as being synonymous given that they are
used interchangeably throughout the code.

- Fix a few other nits also accidentally omitted from the original patch.

Reported by: Harsh Jain on freebsd-net@
Tested by: tjh@
Differential Revision: https://reviews.freebsd.org/D15358

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Add support for the experimental Internet-Draft "TCP Alternative Backoff with
ECN (ABE)" proposal to the New Reno congestion control algorithm module.
ABE reduces the amount of congestion window redu

Add support for the experimental Internet-Draft "TCP Alternative Backoff with
ECN (ABE)" proposal to the New Reno congestion control algorithm module.
ABE reduces the amount of congestion window reduction in response to
ECN-signalled congestion relative to the loss-inferred congestion response.

More details about ABE can be found in the Internet-Draft:
https://tools.ietf.org/html/draft-ietf-tcpm-alternativebackoff-ecn

The implementation introduces four new sysctls:

- net.inet.tcp.cc.abe defaults to 0 (disabled) and can be set to non-zero to
enable ABE for ECN-enabled TCP connections.

- net.inet.tcp.cc.newreno.beta and net.inet.tcp.cc.newreno.beta_ecn set the
multiplicative window decrease factor, specified as a percentage, applied to
the congestion window in response to a loss-based or ECN-based congestion
signal respectively. They default to the values specified in the draft i.e.
beta=50 and beta_ecn=80.

- net.inet.tcp.cc.abe_frlossreduce defaults to 0 (disabled) and can be set to
non-zero to enable the use of standard beta (50% by default) when repairing
loss during an ECN-signalled congestion recovery episode. It enables a more
conservative congestion response and is provided for the purposes of
experimentation as a result of some discussion at IETF 100 in Singapore.

The values of beta and beta_ecn can also be set per-connection by way of the
TCP_CCALGOOPT TCP-level socket option and the new CC_NEWRENO_BETA or
CC_NEWRENO_BETA_ECN CC algo sub-options.

Submitted by: Tom Jones <tj@enoti.me>
Tested by: Tom Jones <tj@enoti.me>, Grenville Armitage <garmitage@swin.edu.au>
Relnotes: Yes
Differential Revision: https://reviews.freebsd.org/D11616

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sys: general adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
pro

sys: general adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

No functional change intended.

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Merge ^/head r321383 through r322397.

MFhead@r321829

MFhead@r321584

Revert r307901 - Inform CC modules about loss events.

This was discussed between various transport@ members and it was
requested to be reverted and discussed.

Submitted by: Kevin Bowling <kevin.bow

Revert r307901 - Inform CC modules about loss events.

This was discussed between various transport@ members and it was
requested to be reverted and discussed.

Submitted by: Kevin Bowling <kevin.bowling@kev009.com>
Reported by: lawrence
Reviewed by: hiren
Sponsored by: Limelight Networks

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Revert r308180 - Set slow start threshold more accurrately on loss ...

This was discussed between various transport@ members and it was
requested to be reverted and discussed.

Submitted by: kevin
R

Revert r308180 - Set slow start threshold more accurrately on loss ...

This was discussed between various transport@ members and it was
requested to be reverted and discussed.

Submitted by: kevin
Reported by: lawerence
Reviewed by: hiren

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Merge ^/head r303250 through r308226.

Set slow start threshold more accurately on loss to be flightsize/2 instead of
cwnd/2 as recommended by RFC5681. (spotted by mmacy at nextbsd dot org)

Restore pre-r307901 behavior of aligning ssthre

Set slow start threshold more accurately on loss to be flightsize/2 instead of
cwnd/2 as recommended by RFC5681. (spotted by mmacy at nextbsd dot org)

Restore pre-r307901 behavior of aligning ssthresh/cwnd on mss boundary. (spotted
by slawa at zxy dot spb dot ru)

Tested by: dim, Slawa <slawa at zxy dot spb dot ru>
MFC after: 1 month
X-MFC with: r307901
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D8349

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Merge ^/head r307736 through r308146.

FreeBSD tcp stack used to inform respective congestion control module about the
loss event but not use or obay the recommendations i.e. values set by it in some
cases.

Here is an attempt to solve th

FreeBSD tcp stack used to inform respective congestion control module about the
loss event but not use or obay the recommendations i.e. values set by it in some
cases.

Here is an attempt to solve that confusion by following relevant RFCs/drafts.
Stack only sets congestion window/slow start threshold values when there is no
CC module availalbe to take that action. All CC modules are inspected and
updated when needed to take appropriate action on loss.

tcp_stacks/fastpath module has been updated to adapt these changes.

Note: Probably, the most significant change would be to not bring congestion
window down to 1MSS on a loss signaled by 3-duplicate acks and letting
respective CC decide that value.

In collaboration with: Matt Macy <mmacy at nextbsd dot org>
Discussed on: transport@ mailing list
Reviewed by: jtl
MFC after: 1 month
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D8225

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Undo r307899. It needs a bit more work and proper commit log.