Re: [PATCH 05/34] tools lib bpf: Add missing bpf map functions

[Wangnan (F)]

On 2016/11/15 12:05, Wang Nan wrote:
> Add more BPF map operations to libbpf.
>
> Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
> Cc: Alexei Starovoitov <ast@xxxxxx>
> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> Cc: Li Zefan <lizefan@xxxxxxxxxx>
> ---
>   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..e966248 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));
> +}
> +
> +int bpf_map_delete_elem(int fd, void *key)
> +{
> +	union bpf_attr attr;
> +
> +	bzero(&attr, sizeof(attr));
> +	attr.map_fd = fd;
> +	attr.key = ptr_to_u64(key);
> +
> +	return sys_bpf(BPF_MAP_DELETE_ELEM, &attr, sizeof(attr));
> +}
> +
> +int bpf_map_get_next_key(int fd, void *key, void *next_key)
> +{
> +	union bpf_attr attr;
> +
> +	bzero(&attr, sizeof(attr));
> +	attr.map_fd = fd;
> +	attr.key = ptr_to_u64(key);
> +	attr.next_key = ptr_to_u64(next_key);
> +
> +	return sys_bpf(BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr));
> +}
> +
> +int bpf_map_pin(int fd, const char *pathname)
> +{
> +	union bpf_attr attr;
> +
> +	bzero(&attr, sizeof(attr));
> +	attr.pathname = ptr_to_u64((void *)pathname);
> +	attr.bpf_fd = fd;
> +
> +	return sys_bpf(BPF_OBJ_PIN, &attr, sizeof(attr));
> +}
> +
> +int bpf_map_get(const char *pathname)
> +{
> +	union bpf_attr attr;
> +
> +	bzero(&attr, sizeof(attr));
> +	attr.pathname = ptr_to_u64((void *)pathname);
> +
> +	return sys_bpf(BPF_OBJ_GET, &attr, sizeof(attr));
> +}

bpf_map_{pin,get} should be rename to bpf_obj_{pin,get} since they can
be used on BPF program. Thanks to Joe Stringer.

> diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
> index e8ba540..5b3e52b 100644
> --- a/tools/lib/bpf/bpf.h
> +++ b/tools/lib/bpf/bpf.h
> @@ -35,4 +35,11 @@ int bpf_load_program(enum bpf_prog_type type, struct bpf_insn *insns,
>   
>   int bpf_map_update_elem(int fd, void *key, void *value,
>   			u64 flags);
> +
> +int bpf_map_lookup_elem(int fd, void *key, void *value);
> +int bpf_map_delete_elem(int fd, void *key);
> +int bpf_map_get_next_key(int fd, void *key, void *next_key);
> +int bpf_map_pin(int fd, const char *pathname);
> +int bpf_map_get(const char *pathname);
> +
>   #endif