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From: Pablo Neira Ayuso <pablo@netfilter.org>
To: Florian Westphal <fw@strlen.de>
Cc: nf-devel <netfilter-devel@vger.kernel.org>
Subject: Re: nfqueue: detect when packet has already been checksummed?
Date: Wed, 29 May 2013 14:23:28 +0200	[thread overview]
Message-ID: <20130529122328.GA6286@localhost> (raw)
In-Reply-To: <20130529120329.GF6578@breakpoint.cc>

On Wed, May 29, 2013 at 02:03:29PM +0200, Florian Westphal wrote:
> Pablo Neira Ayuso <pablo@netfilter.org> wrote:
> > I agree that the current situation is inconsistent. We have no way to
> > know if the kernel validated the checksum or not from user-space, and
> > I think this needs a fix.
> 
> Good :-)
> 
> > We can add a new NFQA_CFG_F_CSUM flag so user-space explicitly ask for
> > assistance regarding checksumming from the kernel. If user-space tries
> > to set that flag and the kernel does not support it, it will hit
> > -EOPNOTSUPP. Thus, we can skip the feature retrieval thing.
> 
> Yes, but this looks like abuse of the flag semantics to me.
> Unless you mean that setting this feat flag should prompt the kernel
> to explicitly call a valiation function in case skb_csum_unnecessary()
> returns false?

I mean exactly the current behaviour but forcing user-space to ask for
it. So skb info flag regarding checksumming comes from kernel if
explicitly requested from user-space.

  reply	other threads:[~2013-05-29 12:23 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-05-26 20:48 nfqueue: detect when packet has already been checksummed? Florian Westphal
2013-05-26 20:48 ` [PATCH] netfilter: nf_queue: add NFQA_SKB_CSUM_NOTVERIFIED info flag Florian Westphal
2013-06-29 12:45   ` Pablo Neira Ayuso
2013-05-29 11:14 ` nfqueue: detect when packet has already been checksummed? Pablo Neira Ayuso
2013-05-29 11:25   ` Florian Westphal
2013-05-29 11:57     ` Pablo Neira Ayuso
2013-05-29 12:03       ` Florian Westphal
2013-05-29 12:23         ` Pablo Neira Ayuso [this message]
2013-05-29 13:25           ` Florian Westphal

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