Re: Re: [PATCH] Add NFPROTO_ARP for mark

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

On Thu, Apr 16, 2015 at 05:39:31AM +0000, Zhang, Chunyu wrote:
> 
> hi pablo
> 
> >From: Pablo Neira Ayuso
> >Date: 2015-04-09
> >To: Zhang, Chunyu/章 春宇
> >Subject: Re: Re: [PATCH] Add NFPROTO_ARP for mark
> >
> >On Thu, Apr 09, 2015 at 03:54:33AM +0000, Zhang, Chunyu wrote:
> >> >From: Pablo Neira Ayuso
> >> >Date: 2015-04-09
> >> >To: Zhang, Chunyu/章 春宇
> >> >Subject: Re: [PATCH] Add NFPROTO_ARP for mark
> >[...]
> >> >> @@ -41,13 +42,23 @@ mark_mt(const struct sk_buff *skb, struct xt_action_param *par)
> >> >>       return ((skb->mark & info->mask) == info->mark) ^ info->invert;
> >> >>  }
> >> >>
> >> >> -static struct xt_target mark_tg_reg __read_mostly = {
> >> >> -     .name           = "MARK",
> >> >> -     .revision       = 2,
> >> >> -     .family         = NFPROTO_UNSPEC,
> >> >> -     .target         = mark_tg,
> >> >> -     .targetsize     = sizeof(struct xt_mark_tginfo2),
> >> >> -     .me             = THIS_MODULE,
> >> >> +static struct xt_target mark_tg_reg[] __read_mostly = {
> >> >> +     {
> >> >> +             .name           = "MARK",
> >> >> +             .revision       = 2,
> >> >> +             .family         = NFPROTO_UNSPEC,
> >> >> +             .target         = mark_tg,
> >> >> +             .targetsize     = sizeof(struct xt_mark_tginfo2),
> >> >> +             .me             = THIS_MODULE,
> >> >> +     },
> >> >> +     {
> >> >> +             .name           = "MARK",
> >> >> +             .revision       = 2,
> >> >> +             .family         = NFPROTO_ARP,
> >> >> +             .target         = mark_tg,
> >> >> +             .targetsize     = sizeof(struct xt_mark_tginfo2),
> >> >> +             .me             = THIS_MODULE,
> >> >> +     }
> >> >>  };
> >> >
> >> >You don't need this.
> >> >
> >> >The problem is here that your patch:
> >> >
> >> >http://patchwork.ozlabs.org/patch/455966/
> >> >
> >> >is missing this chunk:
> >> >
> >> >diff --git a/libarptc/libarptc_incl.c b/libarptc/libarptc_incl.c
> >> >index a034930..87404ce 100644
> >> >--- a/libarptc/libarptc_incl.c
> >> >+++ b/libarptc/libarptc_incl.c
> >> >@@ -872,7 +872,7 @@ map_target(const TC_HANDLE_T handle,
> >> >        /* memset to all 0 for your memcmp convenience. */
> >> >        memset(t->u.user.name + strlen(t->u.user.name),
> >> >               0,
> >> >-              FUNCTION_MAXNAMELEN - strlen(t->u.user.name));
> >> >+              FUNCTION_MAXNAMELEN - 1 - strlen(t->u.user.name));
> >> >        return 1;
> >> > }
> 
> 1. 
> maybe should change like this？
> 
> diff --git a/libarptc/libarptc_incl.c b/libarptc/libarptc_incl.c
> index a034930..4049cbd 100644
> --- a/libarptc/libarptc_incl.c
> +++ b/libarptc/libarptc_incl.c
> @@ -872,7 +872,7 @@ map_target(const TC_HANDLE_T handle,
>         /* memset to all 0 for your memcmp convenience. */
>         memset(t->u.user.name + strlen(t->u.user.name),
>                0,
> -              FUNCTION_MAXNAMELEN - strlen(t->u.user.name));
> +              XT_EXTENSION_MAXNAMELEN - strlen(t->u.user.name));

No, you can't do this.

After getting arptables userspace in sync with kernel headers, you can
see that:

#define ARPT_FUNCTION_MAXNAMELEN XT_FUNCTION_MAXNAMELEN

and:

libarptc/libarptc.c:#define FUNCTION_MAXNAMELEN ARPT_FUNCTION_MAXNAMELEN

You have to do it the way I suggested.

Another motivation to make it the way I indicated is that this will be
in sync with iptables/ip6tables.

Anyway, I have just pushed this branch:

http://git.netfilter.org/arptables/log/?h=next

to try to close this discussion.
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