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Date:   Mon, 2 Aug 2021 19:25:39 +0200
From:   Pali =?utf-8?B?Um9ow6Fy?= <pali@kernel.org>
To:     Andrew Lunn <andrew@lunn.ch>
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: How to find out name or id of newly created interface
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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