Re: [PATCHv2 bpf-next 2/4] xdp: extend xdp_redirect_map with broadcast support

[Hangbin Liu <liuhangbin@gmail.com>]

On Thu, Mar 18, 2021 at 03:19:47PM +0100, Toke Høiland-Jørgensen wrote:
> Hangbin Liu <liuhangbin@gmail.com> writes:
> 
> > On Wed, Mar 17, 2021 at 01:03:02PM +0100, Toke Høiland-Jørgensen wrote:
> >> FYI, this no longer applies to bpf-next due to Björn's refactor in
> >> commit: ee75aef23afe ("bpf, xdp: Restructure redirect actions")
> >
> > Thanks Toke, I need to see how to get the map via map_id, does
> > bpf_map_get_curr_or_next() works? Should I call bpf_map_put() after
> > using?
> 
> I would expect that to be terrible for performance; I think it would be
> better to just add back the map pointer into struct bpf_redirect_info.
> If you only set the map pointer when the multicast flag is set, you can
> just check that pointer to disambiguate between when you need to call
> dev_map_enqueue() and dev_map_enqueue_multi(), in which case you don't
> need to add back the flags member...

There are 2 flags, BROADCAST and EXCLUDE_INGRESS. There is no way
to only check the map pointer and ignore flags..

Thanks
Hangbin