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Date:   Sun, 11 Apr 2021 10:04:11 -0700
From:   Stephen Hemminger <stephen@networkplumber.org>
To:     Ansuel Smith <ansuelsmth@gmail.com>
Cc:     netdev@vger.kernel.org,
        Marek =?UTF-8?B?QmVow7pu?= <marek.behun@nic.cz>,
        David Ahern <dsahern@gmail.com>,
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        Eric Dumazet <edumazet@google.com>,
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        Cong Wang <cong.wang@bytedance.com>,
        Taehee Yoo <ap420073@gmail.com>,
        =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= <bjorn@kernel.org>,
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        linux-kernel@vger.kernel.org
Subject: Re: [PATCH RFC iproute2-next] iplink: allow to change iplink value
Message-ID: <20210411100411.6d16e51d@hermes.local>
In-Reply-To: <20210410133454.4768-5-ansuelsmth@gmail.com>
References: <20210410133454.4768-1-ansuelsmth@gmail.com>
        <20210410133454.4768-5-ansuelsmth@gmail.com>
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On Sat, 10 Apr 2021 15:34:50 +0200
Ansuel Smith <ansuelsmth@gmail.com> wrote:

> Allow to change the interface to which a given interface is linked to.
> This is useful in the case of multi-CPU port DSA, for changing the CPU
> port of a given user port.
>=20
> Signed-off-by: Marek Beh=C3=BAn <marek.behun@nic.cz>
> Cc: David Ahern <dsahern@gmail.com>
> Cc: Stephen Hemminger <stephen@networkplumber.org>

This may work for DSA but it won't work for all the device types vlan/macse=
c/... that
now use the link attribute.  It looks like the change link handling for tho=
se
device types just ignores the link attribute (maybe ok). But before support=
ing this
as an API, it would be better if all the other drivers that use IFLA_LINK
had error checks in their change link handling.

Please add error checks in kernel first.