On 03.11.20 19:42, Willem de Bruijn wrote:
> Thanks. Yes, this is long overdue.
>
> The hard_header_len issue was also recently discussed in the context
> of GRE in commit fdafed459998 ("ip_gre: set dev->hard_header_len and
> dev->needed_headroom properly").
>
> Question is whether we should reserve room in needed_headroom instead.
> AFAIK this existing update logic in ip6_tnl_xmit is sufficient
>
> "
> /* Calculate max headroom for all the headers and adjust
> * needed_headroom if necessary.
> */
> max_headroom = LL_RESERVED_SPACE(dst->dev) + sizeof(struct ipv6hdr)
> + dst->header_len + t->hlen;
> if (max_headroom > dev->needed_headroom)
> dev->needed_headroom = max_headroom;
> "I think that's enough. At least it definitely works in my test and prod
> environment.
Would be good to get another opinion on this though.
>> Fixes: c54419321455 ("GRE: Refactor GRE tunneling code.")
>
> How did you arrive at this SHA1?
I think the legacy usage of hard_header_len in ipv6/sit.c was overseen in
c54419321455.
Please correct me if I'm wrong.
