On Mon, 12 Oct 2026 16:17:41 +0800
Hangbin Liu <[email protected]> wrote:
> [snip]
> > +static bool seg6_flv8986_enabled(__u32 fops)
> > +{
> > + return fops & SEG6_LOCAL_FLV8986_SUPP_OPS;
> > +}
> > +
> > +/* check whether the NEXT-C-SID processing has to be used for the packet,
> > + * instead of the RFC8986 flavors set for the given SRv6 End* behavior
> > + * instance.
> > + *
> > + * This function returns:
> > + * - true, when the packet has to go through the NEXT-C-SID processing;
> > + * - false, when NEXT-C-SID is not configured or the packet has to be
> > + * processed on the basis of the RFC8986 flavors.
> > + */
> > +static bool seg6_use_next_csid(struct sk_buff *skb,
> > + const struct seg6_flavors_info *finfo)
> > +{
> > + const struct in6_addr *addr;
> > + __u32 fops = finfo->flv_ops;
> > +
> > + if (!seg6_next_csid_enabled(fops))
> > + return false;
> > +
> > + addr = &ipv6_hdr(skb)->daddr;
> > +
> > + /* NEXT-C-SID and the RFC8986 flavors combine according to the
> > + * DA.Argument (see RFC9800, sections 4.1.1 and 4.1.7):
> > + *
> > + * DA.Argument RFC8986 flavors processing
> > + * (1) != 0 any NEXT-C-SID only, SL unchanged
> > + * (2) == 0 none the behavior, e.g. End
> > + * (3) == 0 one or more the behavior with its flavors,
> > + * e.g. End with PSP
> > + *
> > + * In (2), the packet still goes through the NEXT-C-SID processing,
> > + * which runs the behavior (e.g. End) when the DA.Argument is zero.
> > + */
> > + return !seg6_flv8986_enabled(fops) ||
> > + !seg6_next_csid_is_arg_zero(addr, finfo);
>
> nit: based on the comment, maybe we can change the order to
>
> return !seg6_next_csid_is_arg_zero(addr, finfo) ||
> !seg6_flv8986_enabled(fops);
>
> No need to change if there is no new version patch.
>
> > +}
>
> [snip]
Hi Hangbin,
thanks for the review and for the suggestion. I would prefer to keep
this order. The table in the comment is meant to describe the cases
rather than the order of the checks. Since testing the 32-bit flavor
mask can be cheaper than checking the DA.Argument, I just put the mask
test first.
Let me know if you see it differently.
Ciao,
Andrea
