Jakub Kicinski <jakub.kicin...@netronome.com> [Tue, 2018-07-10 14:43 -0700]:
> libbpf can guess program type based on ELF section names. As libbpf
> becomes more popular its association between section name strings and
> types becomes more of a standard. Allow libbpf users to use the same
> logic for matching strings to types, e.g. when the string originates
> from command line.
>
> Signed-off-by: Jakub Kicinski <jakub.kicin...@netronome.com>
> Reviewed-by: Quentin Monnet <quentin.mon...@netronome.com>
> ---
> v3 (Andrey):
> - use -EINVAL error code;
> - rename helper to libbpf_prog_type_by_name().
> ---
> tools/lib/bpf/libbpf.c | 43 ++++++++++++++++++++++++------------------
> tools/lib/bpf/libbpf.h | 3 +++
> 2 files changed, 28 insertions(+), 18 deletions(-)
>
> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index 38ed3e92e393..42f31eff5f3f 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -2081,23 +2081,31 @@ static const struct {
> #undef BPF_S_PROG_SEC
> #undef BPF_SA_PROG_SEC
>
> -static int bpf_program__identify_section(struct bpf_program *prog)
> +int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
> + enum bpf_attach_type *expected_attach_type)
> {
> int i;
>
> - if (!prog->section_name)
> - goto err;
> -
> - for (i = 0; i < ARRAY_SIZE(section_names); i++)
> - if (strncmp(prog->section_name, section_names[i].sec,
> - section_names[i].len) == 0)
> - return i;
> + if (!name)
> + return -EINVAL;
>
> -err:
> - pr_warning("failed to guess program type based on section name %s\n",
> - prog->section_name);
> + for (i = 0; i < ARRAY_SIZE(section_names); i++) {
> + if (strncmp(name, section_names[i].sec, section_names[i].len))
> + continue;
> + *prog_type = section_names[i].prog_type;
> + *expected_attach_type = section_names[i].expected_attach_type;
> + return 0;
> + }
> + return -EINVAL;
> +}
>
> - return -1;
> +static int
> +bpf_program__identify_section(struct bpf_program *prog,
> + enum bpf_prog_type *prog_type,
> + enum bpf_attach_type *expected_attach_type)
> +{
> + return libbpf_prog_type_by_name(prog->section_name, prog_type,
> + expected_attach_type);
> }
>
> int bpf_map__fd(struct bpf_map *map)
> @@ -2230,7 +2238,6 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr
> *attr,
> enum bpf_prog_type prog_type;
> struct bpf_object *obj;
> struct bpf_map *map;
> - int section_idx;
> int err;
>
> if (!attr)
> @@ -2252,14 +2259,14 @@ int bpf_prog_load_xattr(const struct
> bpf_prog_load_attr *attr,
> prog->prog_ifindex = attr->ifindex;
> expected_attach_type = attr->expected_attach_type;
> if (prog_type == BPF_PROG_TYPE_UNSPEC) {
> - section_idx = bpf_program__identify_section(prog);
> - if (section_idx < 0) {
> + err = bpf_program__identify_section(prog, &prog_type,
> +
> &expected_attach_type);
> + if (err < 0) {
> + pr_warning("failed to guess program type based
> on section name %s\n",
> + prog->section_name);
> bpf_object__close(obj);
> return -EINVAL;
> }
> - prog_type = section_names[section_idx].prog_type;
> - expected_attach_type =
> - section_names[section_idx].expected_attach_type;
> }
>
> bpf_program__set_type(prog, prog_type);
> diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
> index 564f4be9bae0..d1ce5c828e2e 100644
> --- a/tools/lib/bpf/libbpf.h
> +++ b/tools/lib/bpf/libbpf.h
> @@ -92,6 +92,9 @@ int bpf_object__set_priv(struct bpf_object *obj, void *priv,
> bpf_object_clear_priv_t clear_priv);
> void *bpf_object__priv(struct bpf_object *prog);
>
> +int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
> + enum bpf_attach_type *expected_attach_type);
> +
> /* Accessors of bpf_program */
> struct bpf_program;
> struct bpf_program *bpf_program__next(struct bpf_program *prog,
> --
> 2.17.1
>
Thanks for changes Jakub!
Acked-by: Andrey Ignatov <r...@fb.com>
--
Andrey Ignatov
