From: Stephen Suryaputra <ssuryaextr@gmail.com>
To: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: netfilter-devel@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH nf-next] netfilter: add support for matching IPv4 options
Date: Sat, 1 Jun 2019 22:27:06 -0400 [thread overview]
Message-ID: <20190602022706.GA24477@ubuntu> (raw)
In-Reply-To: <20190603123006.urztqvxyxcm7w3av@salvia>
On Mon, Jun 03, 2019 at 02:30:06PM +0200, Pablo Neira Ayuso wrote:
> > I developed this patchset to suit my employer needs and there is no plan
> > for a follow up patchset, however I think non-zero offset might be useful
> > in the future for tunneled packets.
>
> For tunneled traffic, we can store the network offset in the
> nft_pktinfo object. Then, add a new extension to update this network
> offset to point to the network offset inside the tunnel header, and
> use this pkt->network_offset everywhere.
OK. I'm changing so that offset isn't being used as input. But, it's
still being passed as reference for output. See further response
below...
> I think this new IPv4 options extension should use priv->offset to
> match fields inside the IPv4 option specifically, just like in the
> IPv6 extensions and TCP options do. If you look on how the
> priv->offset is used in the existing code, this offset points to
> values that the specific option field conveys.
I believe that's what I have coded:
err = ipv4_find_option(nft_net(pkt), skb, &offset, priv->type, NULL, NULL);
if (priv->flags & NFT_EXTHDR_F_PRESENT) {
*dest = (err >= 0);
return;
} else if (err < 0) {
goto err;
}
offset += priv->offset;
offset is returned as the offset where it matches the sought priv->type
then priv->offset is added to get to the right field between the offset.
If this is satisfactory, I can submit v2 of the kernel patch.
Thanks,
Stephen.
next prev parent reply other threads:[~2019-06-03 19:03 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-23 9:38 [PATCH nf-next] netfilter: add support for matching IPv4 options Stephen Suryaputra
2019-05-31 17:11 ` Pablo Neira Ayuso
2019-05-31 19:35 ` Stephen Suryaputra
2019-06-01 0:22 ` Pablo Neira Ayuso
2019-06-01 8:27 ` Florian Westphal
2019-06-01 8:40 ` Pablo Neira Ayuso
2019-06-01 8:53 ` Florian Westphal
2019-06-01 15:04 ` Stephen Suryaputra
2019-06-03 12:30 ` Pablo Neira Ayuso
2019-06-02 2:27 ` Stephen Suryaputra [this message]
2019-06-10 15:50 ` Pablo Neira Ayuso
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