Re: [nf-next] netfilter: extend SRH match to support matching previous, next and last SID

Ahmed Abdelsalam
2018-04-23T20:01:48Z

On Mon, 23 Apr 2018 19:30:47 +0200
Pablo Neira Ayuso <pablo@netfilter.org> wrote:

> On Mon, Apr 23, 2018 at 05:48:22AM -0500, Ahmed Abdelsalam wrote:
> > Signed-off-by: Ahmed Abdelsalam <amsalam20@gmail.com>
> > ---
> > include/uapi/linux/netfilter_ipv6/ip6t_srh.h | 22 +++++++++++++--
> > net/ipv6/netfilter/ip6t_srh.c | 41 +++++++++++++++++++++++++++-
> > 2 files changed, 60 insertions(+), 3 deletions(-)
> >
> > diff --git a/include/uapi/linux/netfilter_ipv6/ip6t_srh.h b/include/uapi/linux/netfilter_ipv6/ip6t_srh.h
> > index f3cc0ef..9808382 100644
> > --- a/include/uapi/linux/netfilter_ipv6/ip6t_srh.h
> > +++ b/include/uapi/linux/netfilter_ipv6/ip6t_srh.h
> > @@ -17,7 +17,10 @@
> > #define IP6T_SRH_LAST_GT 0x0100
> > #define IP6T_SRH_LAST_LT 0x0200
> > #define IP6T_SRH_TAG 0x0400
> > -#define IP6T_SRH_MASK 0x07FF
> > +#define IP6T_SRH_PSID 0x0800
> > +#define IP6T_SRH_NSID 0x1000
> > +#define IP6T_SRH_LSID 0x2000
> > +#define IP6T_SRH_MASK 0x3FFF
> >
> > /* Values for "mt_invflags" field in struct ip6t_srh */
> > #define IP6T_SRH_INV_NEXTHDR 0x0001
> > @@ -31,7 +34,10 @@
> > #define IP6T_SRH_INV_LAST_GT 0x0100
> > #define IP6T_SRH_INV_LAST_LT 0x0200
> > #define IP6T_SRH_INV_TAG 0x0400
> > -#define IP6T_SRH_INV_MASK 0x07FF
> > +#define IP6T_SRH_INV_PSID 0x0800
> > +#define IP6T_SRH_INV_NSID 0x1000
> > +#define IP6T_SRH_INV_LSID 0x2000
> > +#define IP6T_SRH_INV_MASK 0x3FFF
> >
> > /**
> > * struct ip6t_srh - SRH match options
> > @@ -40,6 +46,12 @@
> > * @ segs_left: Segments left field of SRH
> > * @ last_entry: Last entry field of SRH
> > * @ tag: Tag field of SRH
> > + * @ psid_addr: Address of previous SID in SRH SID list
> > + * @ nsid_addr: Address of NEXT SID in SRH SID list
> > + * @ lsid_addr: Address of LAST SID in SRH SID list
> > + * @ psid_msk: Mask of previous SID in SRH SID list
> > + * @ nsid_msk: Mask of next SID in SRH SID list
> > + * @ lsid_msk: MAsk of last SID in SRH SID list
> > * @ mt_flags: match options
> > * @ mt_invflags: Invert the sense of match options
> > */
> > @@ -50,6 +62,12 @@ struct ip6t_srh {
> > __u8 segs_left;
> > __u8 last_entry;
> > __u16 tag;
> > + struct in6_addr psid_addr;
> > + struct in6_addr nsid_addr;
> > + struct in6_addr lsid_addr;
> > + struct in6_addr psid_msk;
> > + struct in6_addr nsid_msk;
> > + struct in6_addr lsid_msk;
>
> This is changing something exposed through UAPI, so you will need a
> new revision for this.

Could you please advice what should be done in this case?

>
> > __u16 mt_flags;
> > __u16 mt_invflags;
> > };
> > diff --git a/net/ipv6/netfilter/ip6t_srh.c b/net/ipv6/netfilter/ip6t_srh.c
> > index 33719d5..2b5cc73 100644
> > --- a/net/ipv6/netfilter/ip6t_srh.c
> > +++ b/net/ipv6/netfilter/ip6t_srh.c
> > @@ -30,7 +30,9 @@ static bool srh_mt6(const struct sk_buff *skb, struct xt_action_param *par)
> > const struct ip6t_srh *srhinfo = par->matchinfo;
> > struct ipv6_sr_hdr *srh;
> > struct ipv6_sr_hdr _srh;
> > - int hdrlen, srhoff = 0;
> > + int hdrlen, psidoff, nsidoff, lsidoff, srhoff = 0;
> > + struct in6_addr *psid, *nsid, *lsid;
> > + struct in6_addr _psid, _nsid, _lsid;
>
> Could you rearrange variable definitions? ie. longest line first, eg.
>
> int hdrlen, psidoff, nsidoff, lsidoff, srhoff = 0;
> const struct ip6t_srh *srhinfo = par->matchinfo;
> struct in6_addr *psid, *nsid, *lsid;
> struct ipv6_sr_hdr *srh;
> struct ipv6_sr_hdr _srh;
>

Ok I will re-arrange them in reverse christmas tree form.

Ahmed

--
Ahmed Abdelsalam <amsalam20@gmail.com>