Messages in this thread | | | From | Andrii Nakryiko <> | Date | Tue, 30 Mar 2021 13:39:27 -0700 | Subject | Re: [PATCH bpf-next 3/5] libbpf: add low level TC-BPF API |
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On Sun, Mar 28, 2021 at 1:11 AM Kumar Kartikeya Dwivedi <memxor@gmail.com> wrote: > > 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!
Thanks! I'll take a look. Sorry, I'm a bit behind with all the stuff, trying to catch up.
I was just wondering if it would be more natural instead of having _dev _block variants and having to specify __u32 ifindex, __u32 parent_id, __u32 protocol, to have some struct specifying TC "destination"? Maybe not, but I thought I'd bring this up early. So you'd have just bpf_tc_cls_attach(), and you'd so something like
bpf_tc_cls_attach(prog_fd, TC_DEV(ifindex, parent_id, protocol))
or
bpf_tc_cls_attach(prog_fd, TC_BLOCK(block_idx, protocol))
? Or it's taking it too far?
But even if not, I think detaching can be unified between _dev and _block, can't it?
> > -- > Kartikeya
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