RE: [PATCH] bpf: support BPF_PROG_QUERY for progs attached to sockmap

[John Fastabend]

Di Zhu wrote:
> Right now there is no way to query whether BPF programs are
> attached to a sockmap or not.
> 
> we can use the standard interface in libbpf to query, such as:
> bpf_prog_query(mapFd, BPF_SK_SKB_STREAM_PARSER, 0, NULL, ...);
> the mapFd is the fd of sockmap.
> 
> Signed-off-by: Di Zhu <zhudi2@xxxxxxxxxx>
> ---

LGTM, lets add a small test here as well

  ./tools/testing/selftests/bpf/prog_tests/sockmap_basic.c

Looks like we can just copy the sk_lookup.c test case which does
the query tests for BPF_SK_LOOKUP.

Also I don't think its required for this series, but a bpftool
patch to query it would be useful as well if its doesn't just
work with above.

Thanks!
John