Re: [RFC net-next 08/18] tun: run offloaded XDP program in Tx path

[David Ahern]

On 11/26/19 4:07 AM, Prashant Bhole wrote:
> run offloaded XDP program as soon as packet is removed from the ptr
> ring. Since this is XDP in Tx path, the traditional handling of
> XDP actions XDP_TX/REDIRECT isn't valid. For this reason we call
> do_xdp_generic_core instead of do_xdp_generic. do_xdp_generic_core
> just runs the program and leaves the action handling to us.

What happens if an offloaded program returns XDP_REDIRECT?

Below you just drop the packet which is going to be a bad user
experience. A better user experience is to detect XDP return codes a
program uses, catch those that are not supported for this use case and
fail the install of the program.