On Sun, Mar 28, 2021 at 10:12:40AM IST, Andrii Nakryiko wrote:
Is there some succinct but complete enough documentation/tutorial/etc that I can reasonably read to understand kernel APIs provided by TC (w.r.t. BPF, of course). I'm trying to wrap my head around this and whether API makes sense or not. Please share links, if you have some.
Hi Andrii,
Unfortunately for the kernel API part, I couldn't find any when I was working on this. So I had to read the iproute2 tc code (tc_filter.c, f_bpf.c, m_action.c, m_bpf.c) and the kernel side bits (cls_api.c, cls_bpf.c, act_api.c, act_bpf.c) to grok anything I didn't understand. There's also similar code in libnl (lib/route/{act,cls}.c).
Other than that, these resources were useful (perhaps you already went through some/all of them):
https://docs.cilium.io/en/latest/bpf/#tc-traffic-control https://qmonnet.github.io/whirl-offload/2020/04/11/tc-bpf-direct-action/ tc(8), and tc-bpf(8) man pages
I hope this is helpful!
-- Kartikeya