Re: [bpf-next] bpf: Add CAP_NET_ADMIN for sk_lookup program type

[Alexei Starovoitov]

On Sun, Jan 30, 2022 at 4:25 AM Jakub Sitnicki <jakub@xxxxxxxxxxxxxx> wrote:
>
> On Sun, Jan 30, 2022 at 04:24 AM CET, Alexei Starovoitov wrote:
> > On Sat, Jan 29, 2022 at 6:16 PM He Fengqing <hefengqing@xxxxxxxxxx> wrote:
> >>
> >> SK_LOOKUP program type was introduced in commit e9ddbb7707ff
> >> ("bpf: Introduce SK_LOOKUP program type with a dedicated attach point"),
> >> but the commit did not add SK_LOOKUP program type in net admin prog type.
> >> I think SK_LOOKUP program type should need CAP_NET_ADMIN, so add SK_LOOKUP
> >> program type in net_admin_prog_type.
> >
> > I'm afraid it's too late to change.
> >
> > Jakub, Marek, wdyt?
>
> That's definitely an oversight on my side, considering that CAP_BPF came
> in 5.8, and sk_lookup program first appeared in 5.9.
>
> Today it's possible to build a usable sk_lookup program without
> CAP_NET_ADMIN if you go for REUSEPORT_SOCKARRAY map instead of
> SOCKMAP/HASH.
>
> Best I can come up is a "phase it out" approach. Put the CAP_NET_ADMIN
> load-time check behind a config option, defaulting to true?, and wait
> for it to become obsolete.

I would keep it as-is then. The trouble doesn't feel worth it.