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Patrick Rohr aade10d51d net: change accept_ra_min_rtr_lft to affect all RA lifetimes
commit 5027d54a9c upstream.

accept_ra_min_rtr_lft only considered the lifetime of the default route
and discarded entire RAs accordingly.

This change renames accept_ra_min_rtr_lft to accept_ra_min_lft, and
applies the value to individual RA sections; in particular, router
lifetime, PIO preferred lifetime, and RIO lifetime. If any of those
lifetimes are lower than the configured value, the specific RA section
is ignored.

In order for the sysctl to be useful to Android, it should really apply
to all lifetimes in the RA, since that is what determines the minimum
frequency at which RAs must be processed by the kernel. Android uses
hardware offloads to drop RAs for a fraction of the minimum of all
lifetimes present in the RA (some networks have very frequent RAs (5s)
with high lifetimes (2h)). Despite this, we have encountered networks
that set the router lifetime to 30s which results in very frequent CPU
wakeups. Instead of disabling IPv6 (and dropping IPv6 ethertype in the
WiFi firmware) entirely on such networks, it seems better to ignore the
misconfigured routers while still processing RAs from other IPv6 routers
on the same network (i.e. to support IoT applications).

The previous implementation dropped the entire RA based on router
lifetime. This turned out to be hard to expand to the other lifetimes
present in the RA in a consistent manner; dropping the entire RA based
on RIO/PIO lifetimes would essentially require parsing the whole thing
twice.

Fixes: 1671bcfd76 ("net: add sysctl accept_ra_min_rtr_lft")
Cc: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Patrick Rohr <prohr@google.com>
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20230726230701.919212-1-prohr@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-10-19 23:05:35 +02:00
Documentation net: change accept_ra_min_rtr_lft to affect all RA lifetimes 2023-10-19 23:05:35 +02:00
LICENSES LICENSES/dual/CC-BY-4.0: Git rid of "smart quotes" 2021-07-15 06:31:24 -06:00
arch riscv, bpf: Sign-extend return values 2023-10-19 23:05:34 +02:00
block block: fix use-after-free of q->q_usage_counter 2023-10-10 21:59:05 +02:00
certs certs/blacklist_hashes.c: fix const confusion in certs blacklist 2022-06-22 14:22:01 +02:00
crypto crypto: lrw,xts - Replace strlcpy with strscpy 2023-09-23 11:09:55 +02:00
drivers pinctrl: renesas: rzn1: Enable missing PINMUX 2023-10-19 23:05:34 +02:00
fs quota: Fix slow quotaoff 2023-10-19 23:05:33 +02:00
include net: change accept_ra_min_rtr_lft to affect all RA lifetimes 2023-10-19 23:05:35 +02:00
init x86/mm: Initialize text poking earlier 2023-08-08 19:58:33 +02:00
io_uring io_uring/fs: remove sqe->rw_flags checking from LINKAT 2023-10-06 13:18:22 +02:00
ipc ipc/sem: Fix dangling sem_array access in semtimedop race 2022-12-08 11:28:45 +01:00
kernel workqueue: Override implicit ordered attribute in workqueue_apply_unbound_cpumask() 2023-10-19 23:05:35 +02:00
lib lib/test_meminit: fix off-by-one error in test_pages() 2023-10-19 23:05:33 +02:00
mm mm/vmalloc: add a safer version of find_vm_area() for debug 2023-09-19 12:22:50 +02:00
net net: change accept_ra_min_rtr_lft to affect all RA lifetimes 2023-10-19 23:05:35 +02:00
samples samples/hw_breakpoint: fix building without module unloading 2023-09-23 11:10:01 +02:00
scripts modpost: add missing else to the "of" check 2023-10-10 21:59:07 +02:00
security KEYS: trusted: Remove redundant static calls usage 2023-10-19 23:05:33 +02:00
sound ALSA: usb-audio: Fix microphone sound on Opencomm2 Headset 2023-10-19 23:05:33 +02:00
tools bpf: Fix BTF_ID symbol generation collision in tools/ 2023-10-06 13:18:23 +02:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2022-02-01 17:27:15 +01:00
virt KVM: Grab a reference to KVM for VM and vCPU stats file descriptors 2023-08-03 10:22:40 +02:00
.clang-format clang-format: Update with the latest for_each macro list 2021-05-12 23:32:39 +02:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap mailmap: add Andrej Shadura 2021-10-18 20:22:03 -10:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Daniel Drake to credits 2021-09-21 08:34:58 +03:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS iio: stx104: Move to addac subdirectory 2023-08-26 14:23:27 +02:00
Makefile Linux 5.15.135 2023-10-10 21:59:09 +02:00
README

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.