Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Tue, 12 Jul 2022 19:34:03 +0200
From:   Guillaume Nault <gnault@redhat.com>
To:     Pali =?iso-8859-1?Q?Roh=E1r?= <pali@kernel.org>
Cc:     James Carlson <carlsonj@workingcode.com>,
        Chris Fowler <cfowler@outpostsentinel.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paul Mackerras <paulus@samba.org>,
        "David S. Miller" <davem@davemloft.net>,
        "linux-ppp@vger.kernel.org" <linux-ppp@vger.kernel.org>,
        "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] ppp: Add rtnl attribute IFLA_PPP_UNIT_ID for specifying
 ppp unit id
Message-ID: <20220712173403.GC3794@localhost.localdomain>
References: <20210811180401.owgmie36ydx62iep@pali>
 <20210812092847.GB3525@pc-23.home>
 <20210812134845.npj3m3vzkrmhx6uy@pali>
 <20210812182645.GA10725@pc-23.home>
 <20210812190440.fknfthdk3mazm6px@pali>
 <20210816161114.GA3611@pc-32.home>
 <20210816162355.7ssd53lrpclfvuiz@pali>
 <20210817160525.GA20616@pc-32.home>
 <20210817162155.idyfy53qbxcsf2ga@pali>
 <20220709120906.ymkhn5diywadgrka@pali>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <20220709120906.ymkhn5diywadgrka@pali>
Precedence: bulk

On Sat, Jul 09, 2022 at 02:09:06PM +0200, Pali Roh?r wrote:
> On Tuesday 17 August 2021 18:21:55 Pali Roh?r wrote:
> > On Tuesday 17 August 2021 18:05:25 Guillaume Nault wrote:
> > > On Mon, Aug 16, 2021 at 06:23:55PM +0200, Pali Roh?r 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...
> 
> Sorry for a long delay (I forgot about it). Now I created pull request
> for pppd https://github.com/ppp-project/ppp/pull/354 which adds support
> for creating ppp interface via rtnetlink. rtnetlink is used only when
> ppp unit id was not provided and interface name was provided.

Interesting work. Thanks for working on it!

> > > > 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.
> > > 
>