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

Florian Westphal
2019-06-01T08:27:37Z

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?