On Tue, Jun 13, 2017 at 04:52:32PM -0700, Jakub Kicinski wrote:
> On Tue, 13 Jun 2017 14:08:40 -0700, Martin KaFai Lau wrote:
> > - case XDP_QUERY_PROG:
> > - xdp->prog_attached = !!nn->dp.xdp_prog;
> > + case XDP_QUERY_PROG: {
> > + const struct bpf_prog *xdp_prog;
> > +
> > + xdp_prog = nn->dp.xdp_prog;
> > + if (xdp_prog) {
> > + xdp->prog_id = xdp_prog->aux->id;
> > + xdp->prog_attached = true;
> > + } else {
> > + xdp->prog_id = 0;
> > + xdp->prog_attached = false;
> > + }
> > return 0;
> > + }
>
> I'm sorry to nit pick but it could be done on a single line:
>
> case XDP_QUERY_PROG:
> xdp->prog_attached = !!nn->dp.xdp_prog;
> + xdp->prog_id = nn->dp.xdp_prog ? nn->dp.xdp_prog->aux->id : 0;
> return 0;
> default:
> return -EINVAL;
OK...
>
>
> What would be even cooler is a helper like this:
>
> static inline u32 bpf_prog_id(struct bpf_prog *prog)
> {
> if (!prog)
> return 0;
> return prog->aux->id;
> }
>
> in linux/bpf.h.
Good idea.
I had been thinking I may not need to change all the
drivers now. I did that in v1 because I wanted to remove
prog_attached which is redundant. With prog_attached reserved,
prog_id is optional.
Considering I don't have all the hardwares to test it, I think
it may make more sense for me to only change the HW that I have?
>
> In patch 1 I would be tempted to add a new command for getting the prog
> id, instead of muxing through query to avoid the output parameter? But
> I'm OK with the code as is, its just a preference rather than an objection :)
Have one command to query a new field? I think it is overkilled.
