Re: [PATCH net-next v2 4/5] ipv6: sr: Add seg6local action End.BPF

[Alexei Starovoitov <alexei.starovoitov@gmail.com>]

On Fri, Apr 27, 2018 at 10:59:19AM -0400, David Miller wrote:
> From: Mathieu Xhonneux <m.xhonneux@gmail.com>
> Date: Tue, 24 Apr 2018 18:44:15 +0100
> 
> > This patch adds the End.BPF action to the LWT seg6local infrastructure.
> > This action works like any other seg6local End action, meaning that an IPv6
> > header with SRH is needed, whose DA has to be equal to the SID of the
> > action. It will also advance the SRH to the next segment, the BPF program
> > does not have to take care of this.
> 
> I'd like to see some BPF developers review this change.
> 
> But on my side I wonder if, instead of validating the whole thing afterwards,
> we should make the helpers accessible by the eBPF program validate the changes
> as they are made.

Looking at the code I don't think it's possible to keep it valid all the time
while building, so seg6_validate_srh() after the program run seems necessary.

I think the whole set should be targeting bpf-next tree.
Please fix kbuild errors, rebase and document new helper in man-page style.
Things like:
+	test_btf_haskv.o test_btf_nokv.o test_lwt_seg6local.o
+>>>>>>> selftests/bpf: test for seg6local End.BPF action
should be fixed properly.