On Wed, Mar 31, 2021 at 9:45 AM Yauheni Kaliuta
<yauheni.kaliuta@xxxxxxxxxx> wrote:
>
> From: Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx>
>
> The API gives access to inner map for map in map types (array or
> hash of map). It will be used to dynamically set max_entries in it.
>
> Signed-off-by: Yauheni Kaliuta <yauheni.kaliuta@xxxxxxxxxx>
> ---
> tools/lib/bpf/libbpf.c | 10 ++++++++++
> tools/lib/bpf/libbpf.h | 1 +
> tools/lib/bpf/libbpf.map | 1 +
> 3 files changed, 12 insertions(+)
>
> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index 7aad78dbb4b4..b48dc380059d 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -2194,6 +2194,7 @@ static int parse_btf_map_def(struct bpf_object *obj,
> map->inner_map = calloc(1, sizeof(*map->inner_map));
> if (!map->inner_map)
> return -ENOMEM;
> + map->inner_map->fd = -1;
> map->inner_map->sec_idx = obj->efile.btf_maps_shndx;
> map->inner_map->name = malloc(strlen(map->name) +
> sizeof(".inner") + 1);
> @@ -3845,6 +3846,14 @@ __u32 bpf_map__max_entries(const struct bpf_map *map)
> return map->def.max_entries;
> }
>
> +struct bpf_map *bpf_map__inner_map(struct bpf_map *map)
> +{
> + if (!bpf_map_type__is_map_in_map(map->def.type))
> + return NULL;
> +
> + return map->inner_map;
> +}
> +
> int bpf_map__set_max_entries(struct bpf_map *map, __u32 max_entries)
> {
> if (map->fd >= 0)
> @@ -9476,6 +9485,7 @@ int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd)
> pr_warn("error: inner_map_fd already specified\n");
> return -EINVAL;
> }
> + zfree(&map->inner_map);
> map->inner_map_fd = fd;
> return 0;
> }
> diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
> index f500621d28e5..bec4e6a6e31d 100644
> --- a/tools/lib/bpf/libbpf.h
> +++ b/tools/lib/bpf/libbpf.h
> @@ -480,6 +480,7 @@ LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path);
> LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path);
>
> LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd);
> +LIBBPF_API struct bpf_map *bpf_map__inner_map(struct bpf_map *map);
>
> LIBBPF_API long libbpf_get_error(const void *ptr);
>
> diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
> index f5990f7208ce..eeb6d5ebd1cc 100644
> --- a/tools/lib/bpf/libbpf.map
> +++ b/tools/lib/bpf/libbpf.map
> @@ -360,4 +360,5 @@ LIBBPF_0.4.0 {
> bpf_linker__free;
> bpf_linker__new;
> bpf_object__set_kversion;
> + bpf_map__inner_map;
please keep the list sorted alphabetically
> } LIBBPF_0.3.0;
> --
> 2.31.1
>
