YiFei Zhu <zhuyifei@xxxxxxxxxx> writes: > On Fri, Aug 21, 2020 at 3:58 AM Toke Høiland-Jørgensen <toke@xxxxxxxxxx> wrote: >> Yonghong Song <yhs@xxxxxx> writes: >> > Not sure whether we need formal libbpf API to access metadata or not. >> > This may help other applications too. But we can delay until it is >> > necessary. >> >> Yeah, please put in a libbpf accessor as well; I would like to use this >> from libxdp - without a skeleton :) >> >> -Toke > > I don't think I have an idea on a good API in libbpf that could be > used to get the metadata of an existing program in kernel, that could > be reused by bpftool without duplicating all the code. Maybe we can > discuss this in a follow up series? I think the most important part is getting a reference to the metadata map. So a function that basically does what the top half of what your show_prog_metadata() function does: given a prog fd, walk the map ids, check if any of them looks like a metadata map, and if so return the map fd. Should be pretty straight-forward to reuse between bpftool/libbpf, no? -Toke
