History log of /freebsd-current/sys/netinet/cc/cc_hd.c
Revision Date Author Comments
# 674956e1 10-Apr-2024 Henrich Hartzer <henrichhartzer@tuta.io>

sys/netinet/cc: Switch from deprecated random() to prng32()

Related: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=277655

Signed-off-by: henrichhartzer@tuta.io
Reviewed by: imp, mav
Pull Request: https://github.com/freebsd/freebsd-src/pull/1162


# f74352fb 24-Feb-2024 Richard Scheffenegger <rscheff@FreeBSD.org>

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


# fdafd315 24-Nov-2023 Warner Losh <imp@FreeBSD.org>

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


# 685dc743 16-Aug-2023 Warner Losh <imp@FreeBSD.org>

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

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


# 4d846d26 10-May-2023 Warner Losh <imp@FreeBSD.org>

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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


# e68b3792 07-Dec-2022 Gleb Smirnoff <glebius@FreeBSD.org>

tcp: embed inpcb into tcpcb

For the TCP protocol inpcb storage specify allocation size that would
provide space to most of the data a TCP connection needs, embedding
into struct tcpcb several structures, that previously were allocated
separately.

The most import one is the inpcb itself. With embedding we can provide
strong guarantee that with a valid TCP inpcb the tcpcb is always valid
and vice versa. Also we reduce number of allocs/frees per connection.
The embedded inpcb is placed in the beginning of the struct tcpcb,
since in_pcballoc() requires that. However, later we may want to move
it around for cache line efficiency, and this can be done with a little
effort. The new intotcpcb() macro is ready for such move.

The congestion algorithm data, the TCP timers and osd(9) data are
also embedded into tcpcb, and temprorary struct tcpcb_mem goes away.
There was no extra allocation here, but we went through extra pointer
every time we accessed this data.

One interesting side effect is that now TCP data is allocated from
SMR-protected zone. Potentially this allows the TCP stacks or other
TCP related modules to utilize that for their own synchronization.

Large part of the change was done with sed script:

s/tp->ccv->/tp->t_ccv./g
s/tp->ccv/\&tp->t_ccv/g
s/tp->cc_algo/tp->t_cc/g
s/tp->t_timers->tt_/tp->tt_/g
s/CCV\(ccv, osd\)/\&CCV(ccv, t_osd)/g

Dependency side effect is that code that needs to know struct tcpcb
should also know struct inpcb, that added several <netinet/in_pcb.h>.

Differential revision: https://reviews.freebsd.org/D37127


# b8d60729 11-Nov-2021 Randall Stewart <rrs@FreeBSD.org>

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


# 66ba9aaf 20-Jul-2020 Richard Scheffenegger <rscheff@FreeBSD.org>

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


# 7029da5c 26-Feb-2020 Pawel Biernacki <kaktus@FreeBSD.org>

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


# 855acb84 15-Dec-2018 Brooks Davis <brooks@FreeBSD.org>

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


# 5f901c92 24-Jul-2018 Andrew Turner <andrew@FreeBSD.org>

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


# fe267a55 27-Nov-2017 Pedro F. Giffuni <pfg@FreeBSD.org>

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.


# 4644fda3 27-Jan-2016 Gleb Smirnoff <glebius@FreeBSD.org>

Rename netinet/tcp_cc.h to netinet/cc/cc.h.

Discussed with: lstewart


# 2de3e790 21-Jan-2016 Gleb Smirnoff <glebius@FreeBSD.org>

- Rename cc.h to more meaningful tcp_cc.h.
- Declare it a kernel only include, which it already is.
- Don't include tcp.h implicitly from tcp_cc.h


# b66d74c1 21-Jan-2016 Gleb Smirnoff <glebius@FreeBSD.org>

Cleanup TCP files from unnecessary interface related includes.


# 6df8a710 07-Nov-2014 Gleb Smirnoff <glebius@FreeBSD.org>

Remove SYSCTL_VNET_* macros, and simply put CTLFLAG_VNET where needed.

Sponsored by: Nginx, Inc.


# 891b8ed4 12-Apr-2011 Lawrence Stewart <lstewart@FreeBSD.org>

Use the full and proper company name for Swinburne University of Technology
throughout the source tree.

Requested by: Grenville Armitage, Director of CAIA at Swinburne University of
Technology
MFC after: 3 days


# ac230a79 31-Jan-2011 Lawrence Stewart <lstewart@FreeBSD.org>

Import a clean-room implementation of the Hamilton-Delay (HD) congestion control
algorithm based on the paper "A strategy for fair coexistence of loss and
delay-based congestion control algorithms" by Budzisz, Stanojevic, Shorten and
Baker. It is implemented as a kernel module compatible with the recently
committed modular congestion control framework.

HD uses a probabilistic approach to reacting to delay-based congestion. The
probability of reducing cwnd is zero when the queuing delay is very small,
increasing to a maximum at a set threshold, then back down to zero again when
the queuing delay is high. Normal operation keeps the queuing delay below the
set threshold. However, since loss-based congestion control algorithms push the
queuing delay high when probing for bandwidth, having the probability of
reducing cwnd drop back to zero for high delays allows HD to compete with
loss-based algorithms.

In collaboration with: David Hayes <dahayes at swin edu au> and
Grenville Armitage <garmitage at swin edu au>
Sponsored by: FreeBSD Foundation
Reviewed by: bz and others along the way
MFC after: 3 months