Re: [PATCH net-next v2] ppp: add IFLA_PPP_UNIT netlink attribute

[Qingfang Deng <dqfext@gmail.com>]

On Sat, 14 Mar 2026 02:14:29 +0100, Martin Olivier wrote:
> Currently, the PPP rtnetlink API allows creating a new network interface
> with a custom ifname, but it lacks the ability to specify a custom PPP
> unit id.
> 
> Setting a specific unit id is currently only possible with the
> PPPIOCNEWUNIT ioctl. If a user-space program also requires a custom
> interface name, it must create the interface first with PPPIOCNEWUNIT
> and then rename it.
> 
> Resolve this by introducing the IFLA_PPP_UNIT netlink attribute. This
> allows user-space programs to atomically request both a custom ifname
> and a specific PPP unit id during the RTM_NEWLINK creation process,
> eliminating the post-creation renaming for this use case.
> 
> Signed-off-by: Martin Olivier <martin.olivier@live.fr>
> ---
> Changes in v2:
> - use nl policy to set IFLA_PPP_UNIT min allowed value instead of a manual check in ppp_nl_validate()
> - use of nla_get_s32_default() to collect IFLA_PPP_UNIT value
> Link to v1: https://lore.kernel.org/netdev/PAWP192MB2411A5E7D3BE1B55E155A92F9747A@PAWP192MB2411.EURP192.PROD.OUTLOOK.COM/

The patch itself looks good to me, but I would like to check the
userspace changes too. Please create a pull request at
https://github.com/ppp-project/ppp/pulls

+Cc: Paul Mackerras, Guillaume Nault, Pali Rohár

Regards,
Qingfang