2017-12-07 18:39 UTC+0000 ~ Roman Gushchin <g...@fb.com>
> The bpf_prog_load() function will guess program type if it's not
> specified explicitly. This functionality will be used to implement
> loading of different programs without asking a user to specify
> the program type. In first order it will be used by bpftool.
>
> Signed-off-by: Roman Gushchin <g...@fb.com>
> Cc: Alexei Starovoitov <a...@kernel.org>
> Cc: Daniel Borkmann <dan...@iogearbox.net>
> Cc: Jakub Kicinski <jakub.kicin...@netronome.com>
> Cc: Martin KaFai Lau <ka...@fb.com>
> Cc: Quentin Monnet <quentin.mon...@netronome.com>
> Cc: David Ahern <dsah...@gmail.com>
> ---
> tools/lib/bpf/libbpf.c | 51
> ++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 51 insertions(+)
>
> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index 5aa45f89da93..205b7822fa0a 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -1721,6 +1721,45 @@ BPF_PROG_TYPE_FNS(tracepoint,
> BPF_PROG_TYPE_TRACEPOINT);
> BPF_PROG_TYPE_FNS(xdp, BPF_PROG_TYPE_XDP);
> BPF_PROG_TYPE_FNS(perf_event, BPF_PROG_TYPE_PERF_EVENT);
>
> +#define BPF_PROG_SEC(string, type) { string, sizeof(string), type }
> +static const struct {
> + const char *sec;
> + size_t len;
> + enum bpf_prog_type prog_type;
> +} section_names[] = {
> + BPF_PROG_SEC("socket", BPF_PROG_TYPE_SOCKET_FILTER),
> + BPF_PROG_SEC("kprobe/", BPF_PROG_TYPE_KPROBE),
> + BPF_PROG_SEC("kretprobe/", BPF_PROG_TYPE_KPROBE),
> + BPF_PROG_SEC("tracepoint/", BPF_PROG_TYPE_TRACEPOINT),
> + BPF_PROG_SEC("xdp", BPF_PROG_TYPE_XDP),
> + BPF_PROG_SEC("perf_event", BPF_PROG_TYPE_PERF_EVENT),
> + BPF_PROG_SEC("cgroup/skb", BPF_PROG_TYPE_CGROUP_SKB),
> + BPF_PROG_SEC("cgroup/sock", BPF_PROG_TYPE_CGROUP_SOCK),
> + BPF_PROG_SEC("cgroup/dev", BPF_PROG_TYPE_CGROUP_DEVICE),
> + BPF_PROG_SEC("sockops", BPF_PROG_TYPE_SOCK_OPS),
> + BPF_PROG_SEC("sk_skb", BPF_PROG_TYPE_SK_SKB),
> +};
> +#undef BPF_PROG_SEC
> +
> +static enum bpf_prog_type bpf_program__guess_type(struct bpf_program *prog)
> +{
> + 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 section_names[i].prog_type;
> +
> +err:
> + pr_warning("failed to guess program type based on section name %s\n",
> + prog->section_name);
> +
> + return BPF_PROG_TYPE_UNSPEC;
> +}
> +
> int bpf_map__fd(struct bpf_map *map)
> {
> return map ? map->fd : -EINVAL;
> @@ -1832,6 +1871,18 @@ int bpf_prog_load(const char *file, enum bpf_prog_type
> type,
> return -ENOENT;
> }
>
> + /*
> + * If type is not specified, try to guess it based on
> + * section name.
> + */
> + if (type == BPF_PROG_TYPE_UNSPEC) {
> + type = bpf_program__guess_type(prog);
> + if (type == BPF_PROG_TYPE_UNSPEC) {
> + bpf_object__close(obj);
> + return -EINVAL;
> + }
> + }
> +
> bpf_program__set_type(prog, type);
> err = bpf_object__load(obj);
> if (err) {
>
Looks good to me, nice to avoid the hard-coded string lengths :). Thanks
for the changes!
Quentin
