Re: How to find out name or id of newly created interface

From: Pali Rohár
Date: Mon Aug 02 2021 - 13:25:44 EST


On Monday 02 August 2021 16:21:05 Andrew Lunn wrote:
> > Hello! This has additional issue that I have to choose some free ifindex
> > number and it introduce another race condition that other userspace
> > process may choose same ifindex number. So create request in this case
> > fails if other userspace process is faster... So it has same race
> > condition as specifying interface name.
>
> O.K. if you don't want to deal with retries, you are going to have to
> modify the return value. The nice thing is, its netlink. So you can
> add additional attributes, and not break backwards compatibility. User
> space should ignore all attributes it does not expect.

Guillaume already proposed to implement NLM_F_ECHO...

> But i suspect the architecture of the code is not going to make it
> easy.
>
> Andrew