Re: [PATCH nf-next] netfilter: add support for matching IPv4 options

Pablo Neira Ayuso
2019-06-01T08:40:32Z

On Sat, Jun 01, 2019 at 10:27:32AM +0200, Florian Westphal wrote:
> Pablo Neira Ayuso <pablo@netfilter.org> wrote:
> > > » iph = skb_header_pointer(skb, *offset, sizeof(_iph), &_iph);
> > > » if (!iph || skb->protocol != htons(ETH_P_IP))
> > > » » return -EBADMSG;
> >
> > I mean, you make this check upfront from the _eval() path, ie.
> >
> > static void nft_exthdr_ipv4_eval(const struct nft_expr *expr,
> > ...
> > {
> > ...
> >
> > if (skb->protocol != htons(ETH_P_IP))
> > goto err;
>
> Wouldn't it be preferable to just use nft_pf() != NFPROTO_IPV4?

Then IPv4 options extension won't work from bridge and netdev families
too, right?