Re: [PATCH bpf-next v3 00/16] bpfilter

[Alexei Starovoitov]

On Sat, Dec 24, 2022 at 01:03:46AM +0100, Quentin Deslandes wrote:
> 
> Due to poor hardware availability on my side, I've not been able to
> benchmark those changes. I plan to get some numbers for the next iteration.

Yeah. Performance numbers would be my main question :)

> FORWARD filter chain is now supported, however, it's attached to
> TC INGRESS along with INPUT filter chain. This is due to XDP not supporting
> multiple programs to be attached. I could generate a single program
> out of both INPUT and FORWARD chains, but that would prevent another
> BPF program to be attached to the interface anyway. If a solution
> exists to attach both those programs to XDP while allowing for other
> programs to be attached, it requires more investigation. In the meantime,
> INPUT and FORWARD filtering is supported using TC.

I think we can ignore XDP chaining for now assuming that Daniel's bpf_link-tc work
will be applicable to XDP as well, so we'll have a simple chaining
for XDP eventually.

As far as attaching to TC... I think it would be great to combine bpfilter
codegen and attach to Florian's bpf hooks exactly at netfilter.
See
https://git.breakpoint.cc/cgit/fw/nf-next.git/commit/?h=nf_hook_jit_bpf_29&id=0c1ec06503cb8a142d3ad9f760b72d94ea0091fa
With nf_hook_ingress() calling either into classic iptable or into bpf_prog_run_nf
which is either generated by Florian's optimizer of nf chains or into
bpfilter generated code would be ideal.