netdev - Re: [Cake] [PATCH net] gso_segment: Reset skb->mac

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Date:   Thu, 13 Sep 2018 07:14:30 -0700
From:   Dave Taht <dave.taht@...il.com>
To:     Eric Dumazet <eric.dumazet@...il.com>
Cc:     Toke Høiland-Jørgensen <toke@...e.dk>,
        Linux Kernel Network Developers <netdev@...r.kernel.org>,
        Cake List <cake@...ts.bufferbloat.net>,
        Eric Dumazet <edumazet@...gle.com>
Subject: Re: [Cake] [PATCH net] gso_segment: Reset skb->mac_len after
 modifying network header

On Thu, Sep 13, 2018 at 7:11 AM Eric Dumazet <eric.dumazet@...il.com> wrote:
>
>
>
> On 09/11/2018 03:19 PM, Toke Høiland-Jørgensen wrote:
> > When splitting a GSO segment that consists of encapsulated packets, the
> > skb->mac_len of the segments can end up being set wrong, causing packet
> > drops in particular when using act_mirred and ifb interfaces in
> > combination with a qdisc that splits GSO packets.
> >
> > This happens because at the time skb_segment() is called, network_header
> > will point to the inner header, throwing off the calculation in
> > skb_reset_mac_len(). The network_header is subsequently adjust by the
> > outer IP gso_segment handlers, but they don't set the mac_len.
> >
> > Fix this by adding skb_reset_mac_len() calls to both the IPv4 and IPv6
> > gso_segment handlers, after they modify the network_header.
> >
> > Signed-off-by: Toke Høiland-Jørgensen <toke@...e.dk>
>
> Looks good but I would have appreciated a thanks or something
> after the help I gave on this problem.
>
> Reviewed-by: Eric Dumazet <edumazet@...gle.com>

Thanks, eric! (post-hoc)

Acked-by: Dave Taht <dave.taht@...il.com>

> _______________________________________________
> Cake mailing list
> Cake@...ts.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/cake



-- 

Dave Täht
CEO, TekLibre, LLC
http://www.teklibre.com
Tel: 1-669-226-2619