On Thu, Oct 27, 2022 at 1:00 PM Stanislav Fomichev <sdf@xxxxxxxxxx> wrote:
>
> Allow passing prog_ifindex to BPF_PROG_LOAD. This patch is
> not XDP metadata specific but it's here because we (ab)use
> prog_ifindex as "target metadata" device during loading.
> We can figure out proper UAPI story if we decide to go forward
> with the kfunc approach.
>
> Cc: Martin KaFai Lau <martin.lau@xxxxxxxxx>
> Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
> Cc: Willem de Bruijn <willemb@xxxxxxxxxx>
> Cc: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
> Cc: Anatoly Burakov <anatoly.burakov@xxxxxxxxx>
> Cc: Alexander Lobakin <alexandr.lobakin@xxxxxxxxx>
> Cc: Magnus Karlsson <magnus.karlsson@xxxxxxxxx>
> Cc: Maryam Tahhan <mtahhan@xxxxxxxxxx>
> Cc: xdp-hints@xxxxxxxxxxxxxxx
> Cc: netdev@xxxxxxxxxxxxxxx
> Signed-off-by: Stanislav Fomichev <sdf@xxxxxxxxxx>
> ---
> tools/lib/bpf/libbpf.c | 1 +
> tools/lib/bpf/libbpf.h | 6 +++++-
> 2 files changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index 5d7819edf074..61bc37006fe4 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -7190,6 +7190,7 @@ static int bpf_object_init_progs(struct bpf_object *obj, const struct bpf_object
>
> prog->type = prog->sec_def->prog_type;
> prog->expected_attach_type = prog->sec_def->expected_attach_type;
> + prog->prog_ifindex = opts->prog_ifindex;
>
> /* sec_def can have custom callback which should be called
> * after bpf_program is initialized to adjust its properties
> diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
> index eee883f007f9..4a40b7623099 100644
> --- a/tools/lib/bpf/libbpf.h
> +++ b/tools/lib/bpf/libbpf.h
> @@ -170,9 +170,13 @@ struct bpf_object_open_opts {
> */
> __u32 kernel_log_level;
>
> + /* Optional ifindex of netdev for offload purposes.
> + */
> + int prog_ifindex;
> +
nope, don't do that, open_opts are for entire object, while this is
per-program thing
So bpf_program__set_ifindex() setter would be more appropriate
> size_t :0;
> };
> -#define bpf_object_open_opts__last_field kernel_log_level
> +#define bpf_object_open_opts__last_field prog_ifindex
>
> LIBBPF_API struct bpf_object *bpf_object__open(const char *path);
>
> --
> 2.38.1.273.g43a17bfeac-goog
>
