From mboxrd@z Thu Jan  1 00:00:00 1970
From: Vincent Bernat <vincent@bernat.ch>
Subject: Re: [next] bonding: pass link-local packets to bonding master also.
Date: Thu, 20 Dec 2018 06:55:45 +0100
Message-ID: <87ftuseo7y.fsf@bernat.ch>
References: <20180716011246.225647-1-mahesh@bandewar.net>
        <m3d0qmfe0d.fsf@bernat.ch>
        <120845b4-3828-4473-19bc-ec3ab0b49d4c@ziu.info>
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Cc: Mahesh Bandewar <mahesh@bandewar.net>,
        Jay Vosburgh <j.vosburgh@gmail.com>,
        Andy Gospodarek <andy@greyhouse.net>,
        Veaceslav Falico <vfalico@gmail.com>,
        David Miller <davem@davemloft.net>,
        Netdev <netdev@vger.kernel.org>,
        Mahesh Bandewar <maheshb@google.com>,
        Chonggang Li <chonggangli@google.com>
To: Michal Soltys <soltys@ziu.info>
Return-path: <netdev-owner@vger.kernel.org>
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In-Reply-To: <120845b4-3828-4473-19bc-ec3ab0b49d4c@ziu.info> (Michal Soltys's
        message of "Wed, 19 Dec 2018 23:57:13 +0100")
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 =E2=9D=A6 19 d=C3=A9cembre 2018 23:57 +01, Michal Soltys <soltys@ziu.info>:

>>> Commit b89f04c61efe ("bonding: deliver link-local packets with
>>> skb->dev set to link that packets arrived on") changed the behavior
>>> of how link-local-multicast packets are processed. The change in
>>> the behavior broke some legacy use cases where these packets are
>>> expected to arrive on bonding master device also.
>>=20
>> Unfortunately, this doesn't completely restore the previous
>> functionality as PACKET_ORIGDEV is broken for the copy: the original
>> interface is lost through the call to netif_rx(). A LLDP daemon
>> listening to the master interface won't get the original interface like
>> it was able to before 4.12.
>>=20
>> I am a bit lost of what the original patch was trying to achieve. I am
>> using the following test program:
>>=20
>
> Basing on what you wrote below, it seems that everything was already
> possible before the Chonggang Li's commit ?
>
> If I understand correctly:
>
> - if listening on master, you could get both slave interface
> (PACKET_ORIGDEV) as well as bonding master
> - if listening on slave, you would just get the slave interface
>
> Right ?

Yes. This has been this way since 2.6.27.
--=20
Test programs at their boundary values.
            - The Elements of Programming Style (Kernighan & Plauger)