Re: [bpf-next PATCH 0/3] bpf: improvements to xdp_fwd sample

[Jesper Dangaard Brouer <brouer@redhat.com>]

Hi XDP-newbies,

I cross-posted this patchset to remind XDP-users that the kernel
since[2] v4.18 have a BPF helper (bpf_fib_lookup) to do forwarding
lookups in kernel FIB route table directly from XDP.

The XDP-tutorial now have an assignment[3] 'packet03-redirecting' that
also uses this FIB helper (special thanks to Anton Protopopov for
adding this).

Toke's devmap lookup improvement is first avail in kernel v5.3.
Thus, not part of XDP-tutorial yet.


[2] 87f5fc7e48dd ("bpf: Provide helper to do forwarding lookups in kernel FIB table")
 https://git.kernel.org/torvalds/c/87f5fc7e48dd

[3] https://github.com/xdp-project/xdp-tutorial/blob/master/packet03-redirecting/


On Wed, 07 Aug 2019 14:36:12 +0200
Jesper Dangaard Brouer <brouer@redhat.com> wrote:

> This patchset is focused on improvements for XDP forwarding sample
> named xdp_fwd, which leverage the existing FIB routing tables as
> described in LPC2018[1] talk by David Ahern.
> 
> The primary motivation is to illustrate how Toke's recent work
> improves usability of XDP_REDIRECT via lookups in devmap. The other
> patches are to help users understand the sample.
> 
> I have more improvements to xdp_fwd, but those might requires changes
> to libbpf.  Thus, sending these patches first as they are isolated.
> 
> [1] http://vger.kernel.org/lpc-networking2018.html#session-1


-- 
Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Principal Kernel Engineer at Red Hat
  LinkedIn: http://www.linkedin.com/in/brouer