From: Florian Westphal <fw@strlen.de>
To: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Florian Westphal <fw@strlen.de>,
nf-devel <netfilter-devel@vger.kernel.org>
Subject: Re: nfqueue: detect when packet has already been checksummed?
Date: Wed, 29 May 2013 14:03:29 +0200 [thread overview]
Message-ID: <20130529120329.GF6578@breakpoint.cc> (raw)
In-Reply-To: <20130529115705.GA5315@localhost>
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 think that this is overkill, and, it might not work
in all cases (e.g. if the layer4 protocol is unknown to us).
next prev parent reply other threads:[~2013-05-29 12:03 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 [this message]
2013-05-29 12:23 ` Pablo Neira Ayuso
2013-05-29 13:25 ` Florian Westphal
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