From: Dominique Martinet <asmadeus@codewreck.org>
Date: Tue, 18 Sep 2018 04:45:36 +0200

David Miller wrote on Mon, Sep 17, 2018:

quoted

Remind me, is there actually any way for the bpf programs run in this
situation to even _see_ strp_msg(skb)->offset at all?

No, they can see it, so it's possible to make a KCM program that works
right now if you are careful (I'm not sure why the offset within bpf is
different from the offset in the kernel though, it looks like the bpf
program skips the qos part of the control buffer)

What helper is used in the BPF program to get this offset value?

(also good info to add to the commit message)