Re: [PATCH v3 net-next] net: introduce dev_set_forwarding()

Herbert Xu
2013-11-03T12:28:45Z

On Sat, Nov 02, 2013 at 07:01:37AM -0700, Eric Dumazet wrote:
> From: Eric Dumazet <edumazet@google.com>
>
> Christoph Paasch and Jerry Chu reported crashes in skb_segment() caused
> by commit 8a29111c7ca6 ("net: gro: allow to build full sized skb")
>
> skb_segment() only deals with a frag_list chain containing MSS sized
> fragments. Even if we fix this problem, its better if GRO layer
> doesn't build skb with a frag_list in the first place, to let TSO
> packets reaching output devices.
>
> David Miller and Ben Hutchings suggested we keep track of number of
> forwarding users to be able to :
>
> - Disable LRO
> - Make sure GRO layer do not use skb frag_list to extend skb capacity

Why are we still doing this instead of fixing skb_segment to
deal with skb frag_list properly?

LRO is legacy code and we should not be adding similar cruft
to GRO.

Cheers,
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
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