[nf-next,4/4] netfilter: ipv6: avoid nf_iterate recursion

On 17 October 2015 at 13:14, Florian Westphal <fw@strlen.de> wrote:
> @@ -606,19 +599,22 @@ struct sk_buff *nf_ct_frag6_gather(struct net *net, struct sk_buff *skb, u32 use
>                 spin_unlock_bh(&fq->q.lock);
>                 pr_debug("Can't insert skb to queue\n");
>                 inet_frag_put(&fq->q, &nf_frags);
> -               return skb;
> +               return -EINVAL;
>         }
>
> +       /* after queue has assumed skb ownership, only 0 or -EINPROGRESS
> +        * must be returned.
> +        */
> +       ret = -EINPROGRESS;
>         if (fq->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
> -           fq->q.meat == fq->q.len) {
> -               ret_skb = nf_ct_frag6_reasm(fq, skb, dev);
> -               if (ret_skb == NULL)
> -                       pr_debug("Can't reassemble fragmented packets\n");
> -       }
> +           fq->q.meat == fq->q.len &&
> +           nf_ct_frag6_reasm(fq, skb, dev))
> +               ret = 0;
> +
>         spin_unlock_bh(&fq->q.lock);
>
>         inet_frag_put(&fq->q, &nf_frags);
> -       return ret_skb;
> +       return ret;
>  }
>  EXPORT_SYMBOL_GPL(nf_ct_frag6_gather);

Minor nit below, feel free to disregard if it misses some code style
guideline. The lock/unlock reads easier to me if the
unlocking/frag_put is grouped together, something like the following
incremental:

        /* after queue has assumed skb ownership, only 0 or -EINPROGRESS
@@ -611,9 +609,11 @@ int nf_ct_frag6_gather(struct net *net, struct
sk_buff *skb, u32 user)
            nf_ct_frag6_reasm(fq, skb, dev))
                ret = 0;

+unlock:
        spin_unlock_bh(&fq->q.lock);
-
        inet_frag_put(&fq->q, &nf_frags);
+       if (unlikely(ret == -EINVAL))
+               pr_debug("Can't insert skb to queue\n");
        return ret;
 }
 EXPORT_SYMBOL_GPL(nf_ct_frag6_gather);
--
To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Joe Stringer <joestringer@nicira.com> wrote:
> On 17 October 2015 at 13:14, Florian Westphal <fw@strlen.de> wrote:
> > @@ -606,19 +599,22 @@ struct sk_buff *nf_ct_frag6_gather(struct net *net, struct sk_buff *skb, u32 use
> >                 spin_unlock_bh(&fq->q.lock);
> >                 pr_debug("Can't insert skb to queue\n");
> >                 inet_frag_put(&fq->q, &nf_frags);
> > -               return skb;
> > +               return -EINVAL;
> >         }
> >
> > +       /* after queue has assumed skb ownership, only 0 or -EINPROGRESS
> > +        * must be returned.
> > +        */
> > +       ret = -EINPROGRESS;
> >         if (fq->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
> > -           fq->q.meat == fq->q.len) {
> > -               ret_skb = nf_ct_frag6_reasm(fq, skb, dev);
> > -               if (ret_skb == NULL)
> > -                       pr_debug("Can't reassemble fragmented packets\n");
> > -       }
> > +           fq->q.meat == fq->q.len &&
> > +           nf_ct_frag6_reasm(fq, skb, dev))
> > +               ret = 0;
> > +
> >         spin_unlock_bh(&fq->q.lock);
> >
> >         inet_frag_put(&fq->q, &nf_frags);
> > -       return ret_skb;
> > +       return ret;
> >  }
> >  EXPORT_SYMBOL_GPL(nf_ct_frag6_gather);
> 
> Minor nit below, feel free to disregard if it misses some code style
> guideline. The lock/unlock reads easier to me if the
> unlocking/frag_put is grouped together, something like the following
> incremental:

I like it, will change it for v2.

Thanks!
--
To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html