Re: Support for nv(9) in if_clone

On Wed, 15 Oct 2025 11:15:03 +0330
Seyed Pouria Mousavizadeh Tehrani <[email protected]> wrote:

> Currently our ifreq interface supports nv(9) lists via ifreq_nv_req. 
> This allows network interface drivers to implement their configuration 
> using nvlists (for example: if_ovpn, if_pf*).
> 
> There is a problem: an interface that is implemented entirely via nv(9) 
> cannot be configured during the cloning phase (via if_clone_create). 
> if_clone_create converts the ifreq struct to ifdrv and only copies 
> ifr_data to params, so the ifru_nv field is lost during cloning.
> 
> I am interested in implementing a solution to this issue and am 
> considering two possible approaches:
> 
>  1. Extend the ifdrv struct to include the ifreq_nv_req struct, and
>     verify/make sure that other implemented modules are not affected.
>  2. Introduce a new ioctl, SIOCIFCREATENV, to handle the nv part
>     separately, which would be more complicated but potentially less
>     disruptive to existing modules.
> 
> Which one do you think would be more suitable, or do you have any 
> alternative suggestions?

I'd vote for the latter, because it also will make task easier when/if/ever
the nvlist plague will be replaced by something more sane.

-- 
WBR, @nuclight