Re: [PATCH] net-gre-gro: Fix a bug that breaks the forwarding path

[Joseph Gasparakis <joseph.gasparakis@intel.com>]

On Wed, 5 Mar 2014, Or Gerlitz wrote:

> On Wed, Mar 5, 2014 at 2:50 AM, Tom Herbert <therbert@google.com> wrote:
> > I am concerned that we are overloading the skb->encpasulation
> 
> Guys, so to sum up yesterday's messages on this thread -- do folks
> think we can come up with better/proper definition for the
> skb->encapsulation bit, or we have to make this multiple bits, or we
> have (hopefully not too non linear) dependancy on proper
> definitions/usage of the skb->ip_summed field?
> 
> 
> Or.
>

>From my perspective I do not see a gap with the mentioned fields, but I am 
open if anyone has something to suggest.

Joseph
 
> > for instance if this is set in TX path meaning inner headers are valid,
> > this should also be true of RX. It might be better if this field
> > indicated characteristics of the packet independent of being in RX or
> > TX path. For checksum, maybe we should have a separate encap_checksum
> > field. Also, to be future proof may this should be two bits for the
> > devices that can verify checksums in multiple levels of encapsulations
> > (yes, I know this sounds absurd, but it's no more absurd than devices
> > vendors taking it upon themselves to parse to some restricted set of
> > encapsulations instead of just giving us the full packet checksum! :-)).
> 
> > I hope to have patches soon on fixing CHECKSUM_COMPLETE, I think it
> > entails some more state in skb indicating offset and extent of
> > checksum value in the packet. An like a said, we need to get out of
> > the habit of stashing pseudo csums there (unless CHECKSUM_PARTIAL is
> > set).
> >
> >> Also for Tx, skb->encapsulation should be the indication to the
> >> driver that it can use the inner headers (i.e. they are valid) in the skb
> >> in order to offload the inner csum.
>