Date:   Mon, 13 Mar 2023 14:39:17 -0700
From:   Jakub Kicinski <kuba@kernel.org>
To:     Jorge Merlino <jorge.merlino@canonical.com>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Paolo Abeni <pabeni@redhat.com>, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org
Subject: Re: [PATCH] Add symlink in /sys/class/net for interface altnames
Message-ID: <20230313143917.076da099@kernel.org>
In-Reply-To: <20230313164903.839-1-jorge.merlino@canonical.com>
References: <20230313164903.839-1-jorge.merlino@canonical.com>
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On Mon, 13 Mar 2023 13:49:03 -0300 Jorge Merlino wrote:
> Currently interface altnames behave almost the same as the interface
> principal name. One difference is that the not have a symlink in
> /sys/class/net as the principal has.
> This was mentioned as a TODO item in the original commit:
> https://lore.kernel.org/netdev/20190719110029.29466-1-jiri@resnulli.us
> This patch adds that symlink when an altname is created and removes it
> when the altname is deleted.

I think this is risky. Altnames are added by systemd on unsuspecting
systems, and I've seen configurations systems which assume that all
/sys/class/net entries are separate devices (basically counting how 
many NICs machine has).

I'm afraid it's too late.