Re: [PATCH v5 bpf-next 00/11] net: Add support for XDP in egress path

On 5/19/20 7:31 AM, Daniel Borkmann wrote:

I meant that the dev{map,hash} would get extended in a way where the
__dev_map_update_elem() receives an (ifindex, BPF prog fd) tuple from
user space and holds the program's ref as long as it is in the map slot.
Then, upon redirect to the given device in the devmap, we'd execute the
prog as well in order to also allow for XDP_DROP policy in there. Upon
map update when we drop the dev from the map slot, we also release the
reference to the associated BPF prog. What I mean to say wrt 'property
of the devmap' is that this program is _only_ used in combination with
redirection to devmap, so given we are not solving all the other egress
cases for reasons mentioned, it would make sense to tie it logically to
the devmap which would also make it clear from a user perspective _when_
the prog is expected to run.

Thanks. I will take a look at this.