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From:   Eric Dumazet <edumazet@google.com>
Date:   Tue, 15 Feb 2022 09:06:39 -0800
Message-ID: <CANn89iLtXW-MFJ74UhP4WyC3a60LrevAxddBjJ1nGu78eSG1DQ@mail.gmail.com>
Subject: Re: [PATCH] gso: do not skip outer ip header in case of ipip and net_failover
To:     Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Cc:     Tao Liu <thomas.liu@ucloud.cn>, David Miller <davem@davemloft.net>,
        Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
        David Ahern <dsahern@kernel.org>,
        Jakub Kicinski <kuba@kernel.org>,
        "Samudrala, Sridhar" <sridhar.samudrala@intel.com>,
        Network Development <netdev@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
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On Tue, Feb 15, 2022 at 7:46 AM Willem de Bruijn
<willemdebruijn.kernel@gmail.com> wrote:

> > Stuffing state in the skb has been a mistake I think.
>
> If we could unwind those skb inner_* fields (and reclaim the skbuff
> space!) that would be fantastic.

Not sure we can easily remove the space, many networking drivers need them,
we probably do not want to dissect packets in their ndo_start_xmit()

>
> Immediately for this bug: perhaps it can be fixed by resetting the
> network_header on the gso skb if segs == NULL. As the offset is stored
> on the stack.

It seems correct. Any other fields we need to take care of ?