Re: [PATCH] extensions: libip6t_hbh: Add translation to nft

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

On Wed, Mar 02, 2016 at 07:17:36PM +0530, Shivani Bhardwaj wrote:
> On Wed, Mar 2, 2016 at 5:19 PM, Pablo Neira Ayuso <pablo@netfilter.org> wrote:
> > On Wed, Mar 02, 2016 at 03:22:43AM +0530, Shivani Bhardwaj wrote:
> >> Add translation for module hop-by-hop to nftables.
> >> Full translation of this match awaits the support for --hbh-opts option.
> >>
> >> Examples:
> >>
> >> $ sudo ip6tables-translate -A INPUT -m hbh --hbh-len 33
> >> nft add rule ip6 filter INPUT hbh hdrlength 33 counter
> >>
> >> $ sudo ip6tables-translate -A INPUT -m hbh ! --hbh-len 33
> >> nft add rule ip6 filter INPUT hbh hdrlength != 33 counter
> >>
> >> Signed-off-by: Shivani Bhardwaj <shivanib134@gmail.com>
> >> ---
> >>  extensions/libip6t_hbh.c | 17 +++++++++++++++++
> >>  1 file changed, 17 insertions(+)
> >>
> >> diff --git a/extensions/libip6t_hbh.c b/extensions/libip6t_hbh.c
> >> index c0389ed..f968036 100644
> >> --- a/extensions/libip6t_hbh.c
> >> +++ b/extensions/libip6t_hbh.c
> >> @@ -164,6 +164,22 @@ static void hbh_save(const void *ip, const struct xt_entry_match *match)
> >>       print_options(optinfo->optsnr, (uint16_t *)optinfo->opts);
> >>  }
> >>
> >> +static int hbh_xlate(const struct xt_entry_match *match,
> >> +                  struct xt_xlate *xl, int numeric)
> >> +{
> >> +     const struct ip6t_opts *optinfo = (struct ip6t_opts *)match->data;
> >> +
> >> +     xt_xlate_add(xl, "hbh ");
> >> +
> >> +     if (optinfo->flags & IP6T_OPTS_LEN) {
> >
> > If no header length is passed, then this will print:
> >
> > nft add rule ip6 filter INPUT hbh counter
> >
> 
> What should be the rule generated in case none of the options is mentioned?
> 
> # iptables-translate -A INPUT -m hbh
> ?

Please, have a look at linux/net/ipv6/netfilter/ip6t_hbh.c and
evaluate what is the behaviour in case -m hbh is passed with not
options.