On Tue, May 30, 2017 at 06:35:37PM -0600, David Ahern wrote:

On 5/30/17 6:08 PM, Martin KaFai Lau wrote:

quoted

This patch series:
1) Introduce ID for both bpf_prog and bpf_map.
2) Add bpf commands to iterate the prog IDs and map
   IDs of the system.
3) Add bpf commands to get a prog/map fd from an ID
4) Add bpf command to get prog/map info from a fd.
   The prog/map info is a jump start in this patchset
   and it is not meant to be a complete list.  They can
   be extended in the future patches.

Interesting. This really simplifies the bpf retrieval I have been
working on:
    https://github.com/dsahern/linux/commits/bpf/retrieve-bpf-wip

Having the net device, filter, route, socket, cgroup, etc return the ids
for attached programs solves the problem of getting a reference to all
of the places BPF programs can be placed.

Right, it is the idea.

I am also baking some follow-up patches for returning xdp-prog's id
through netlink.

This patch set turns an id into a fd, and my patches allow the fd to be
used to get the bpf code.