Re: [PATCH] extensions: libip6t_frag: Add translation to nft

[Pablo Neira Ayuso <pablo@netfilter.org>]

On Thu, Jun 02, 2016 at 06:57:58PM +0200, Laura Garcia Liebana wrote:
> Add translation for frag to nftables. Not supported yet in nft: fraglen,
> fragfirst and fraglast.

You can provide translations for fragfirst and fraglast.

'--fragfirst' is actually frag-off 0.
and '--fraglast' is more-fragments 1.

Note that because there is no 1:1 mapping, it doesn't mean you can
translate things.

And regarding --fraglen, if you look at
iptables/extensions/libip6t_frag.c, you'll see:

        case O_FRAGLEN:
                /*
                 * As of Linux 3.0, the kernel does not check for
                 * fraglen at all.
                 */
                if (cb->invert)
                        fraginfo->invflags |= IP6T_FRAG_INV_LEN;
                fraginfo->flags |= IP6T_FRAG_LEN;
                break;

Then, browsing:

http://lxr.free-electrons.com/source/net/ipv6/netfilter/ip6t_frag.c

shows no references to IP6T_FRAG_LEN in the kernel, so this confirms
this option was already deprecated time ago and the comment in the
iptables source code is correct.

Please, respin and send a v2 including this useful information on the
commit message so we keep this in the record.