Re: [PATCH] netfilter: xtables: Add snapshot of hardidletimer target

[Arturo Borrero Gonzalez <arturo@netfilter.org>]

On 11/11/19 7:56 AM, Manoj Basapathi wrote:
> This is a snapshot of hardifletimer netfilter target as of msm-4.4
> commit 469a150b7426 ("netfilter: xtables: hardidletimer target implementation")
> 
> This patch implements a hardidletimer Xtables target that can be
> used to identify when interfaces have been idle for a certain period
> of time.
> 
> Timers are identified by labels and are created when a rule is set
> with a new label. The rules also take a timeout value (in seconds) as
> an option. If more than one rule uses the same timer label, the timer
> will be restarted whenever any of the rules get a hit.
> 
> One entry for each timer is created in sysfs. This attribute contains
> the timer remaining for the timer to expire. The attributes are
> located under the xt_idletimer class:
> 
> /sys/class/xt_hardidletimer/timers/<label>
> 
> When the timer expires, the target module sends a sysfs notification
> to the userspace, which can then decide what to do (eg. disconnect to
> save power)
> 
> Compared to xt_IDLETIMER, xt_HARDIDLETIMER can send notifications when
> CPU is in suspend too, to notify the timer expiry.
> 
> Change-Id: Ib2e05af7267f3c86d1967f149f7e7e782c59807e
> Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
> Signed-off-by: Manoj Basapathi <manojbm@codeaurora.org>
> ---
>  .../uapi/linux/netfilter/xt_HARDIDLETIMER.h   |  51 +++
>  net/netfilter/Kconfig                         |  14 +
>  net/netfilter/Makefile                        |   1 +
>  net/netfilter/xt_HARDIDLETIMER.c              | 381 ++++++++++++++++++
>  net/netfilter/xt_IDLETIMER.c                  |   2 +
>  5 files changed, 449 insertions(+)
>  create mode 100644 include/uapi/linux/netfilter/xt_HARDIDLETIMER.h
>  create mode 100644 net/netfilter/xt_HARDIDLETIMER.c

I have nothing to comment on the patch itself.

But I wonder what would it take to implement this in the nf_tables framework.