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Date:   Thu, 15 Mar 2018 09:35:51 -0700 (PDT)
From:   Liran Alon <liran.alon@oracle.com>
To:     <shmulik.ladkani@gmail.com>
Cc:     <netdev@vger.kernel.org>, <daniel@iogearbox.net>,
        <mrv@mojatatu.com>, <davem@davemloft.net>,
        <linux-kernel@vger.kernel.org>, <yuval.shaia@oracle.com>,
        <idan.brown@oracle.com>
Subject: Re: [PATCH] net: dev_forward_skb(): Scrub packet's per-netns info
 only when crossing netns
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----- shmulik.ladkani@gmail.com wrote:

> On Thu, 15 Mar 2018 08:01:03 -0700 (PDT) Liran Alon
> <liran.alon@oracle.com> wrote:
> >=20
> > I still think that default behavior should be to zero skb->mark only
> when skb
> > cross netdevs in different netns.
>=20
> But the previous default was scrub the mark in *both* xnet and
> non-xnet
> situations.
>=20
> Therefore, there might be users which RELY on this (strange) default
> behavior in their same-netns-veth-pair setups.
> Meaning, changing the default behavior might break their apps relying
> on
> the former default behavior.
>=20
> This is why the "disable mark scrubbing in non-xnet case" should be
> opt-in.

We think the same.
The only difference is that I think this for now should be controllable
by a global /proc/sys/net/core file instead of giving a flexible per-netdev=
 control.
Because that is a larger change that could be done later.

>=20
> Regards,
> Shmulik