Re: sysctl, argument parsing, possible bug

From: Stephen Hemminger
Date: Tue Aug 08 2017 - 15:04:50 EST


On Tue, 8 Aug 2017 20:26:36 +0200
Massimo Sala <massimo.sala.71@xxxxxxxxx> wrote:

> I make another test with kernel 4.9.32-15.41
>
> sysctl procps version 3.2.8
>
> sysctl net.ipv4.conf.eth0.100.forwarding
> error: "net.ipv4.conf.eth0.100.forwarding" is an unknown key
>
>
> so I install busybox :
>
> BusyBox v1.19.3
>
> busybox sysctl net.ipv4.conf.eth0.100.forwarding
> net.ipv4.conf.eth0.100.forwarding = 0
>
> It is working, as I expect reading busybox source sysctl.c
>
>
>
> Stephen, I test
> sysctl net/ipv4/conf/eth0.100/forwarding
> I confirm it works.
>
>
> What is the problem ?
>
> As sysctl, also automation tools and scripts cannot be "netdev names
> aware", and so they fail using the usual dot notation.
>
>
> I don't pretend to change sysctl to read from the /proc/sys/
> directory, as busybox does.
>
> I suggest to add a remark to the man page of sysctl, reporting the
> difference between the two tools and an example of the alternate
> syntax :
> sysctl net/ipv4/conf/eth0.100/forwarding
>
>
> Thank you for your attention.
> Best regards, Massimo

Busybox has always been a restricted subset of the upstream standard tools.
If you have problems with busybox take it up with those developers directly;
this is not the right mailing list for that.