Re: [PATCH] ppp: Add rtnl attribute IFLA_PPP_UNIT_ID for specifying ppp unit id

[Pali Rohár]

On Tuesday 17 August 2021 18:05:25 Guillaume Nault wrote:
> On Mon, Aug 16, 2021 at 06:23:55PM +0200, Pali Rohár wrote:
> > On Monday 16 August 2021 18:11:14 Guillaume Nault wrote:
> > > Do you have plans for adding netlink support to pppd? If so, is the
> > > project ready to accept such code?
> > 
> > Yes, I have already some WIP code and I'm planning to send a pull
> > request to pppd on github for it. I guess that it could be accepted,
> 
> I guess you can easily use the netlink api for cases where the "unit"
> option isn't specified and fall back to the ioctl api when it is. If
> all goes well, then we can extend the netlink api to accept a unit id.
> 
> But what about the lack of netlink feedback about the created
> interface? Are you restricted to use netlink only when the "ifname"
> option is provided?

Exactly, this is how I wrote my WIP code...

> > specially if there still would be backward compatibility via ioctl for
> > kernels which do not support rtnl API.
> 
> Indeed, I'd expect keeping compatiblitity with old kernels that only
> have the ioctl api to be a must (but I have no experience contributing
> to the pppd project).
> 
> > One of the argument which can be
> > used why rtnl API is better, is fixing issue: atomic creating of
> > interface with specific name.
> 
> Yes, that looks useful.
>