Re: [PATCH v3 01/30] tools lib bpf: Add missing BPF functions

[Alexei Starovoitov <alexei.starovoitov@gmail.com>]

On Sat, Nov 26, 2016 at 07:03:25AM +0000, Wang Nan wrote:
> Add more BPF map operations to libbpf. Also add bpf_obj_{pin,get}(). They
> can be used on not only BPF maps but also BPF programs.
> 
> Signed-off-by: Wang Nan <wangnan0@huawei.com>
> Cc: Alexei Starovoitov <ast@fb.com>
> Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
> Cc: Joe Stringer <joe@ovn.org>
> Cc: Li Zefan <lizefan@huawei.com>
> ---
>  tools/lib/bpf/bpf.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>  tools/lib/bpf/bpf.h |  7 +++++++
>  2 files changed, 63 insertions(+)
> 
> diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
> index 4212ed6..8143536 100644
> --- a/tools/lib/bpf/bpf.c
> +++ b/tools/lib/bpf/bpf.c
> @@ -110,3 +110,59 @@ int bpf_map_update_elem(int fd, void *key, void *value,
>  
>  	return sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));
>  }
> +
> +int bpf_map_lookup_elem(int fd, void *key, void *value)
> +{
> +	union bpf_attr attr;
> +
> +	bzero(&attr, sizeof(attr));
> +	attr.map_fd = fd;
> +	attr.key = ptr_to_u64(key);
> +	attr.value = ptr_to_u64(value);
> +
> +	return sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
> +}

Acked-by: Alexei Starovoitov <ast@kernel.org>