tools lib bpf: Add bpf_map__pin()

Add a new API to pin a BPF map to the filesystem. The user can specify
the path full path within a BPF filesystem to pin the map.

Signed-off-by: Joe Stringer <joe@ovn.org>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/20170126212001.14103-3-joe@ovn.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index c4465b2fddf653da68dc4d632ecee753b075ae1f..6a8c8beeb291921dd79a4782a8c66c23d58c3efd 100644 (file)
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -1357,6 +1357,28 @@ int bpf_program__pin(struct bpf_program *prog, const char *path)
        return 0;
 }
 
+int bpf_map__pin(struct bpf_map *map, const char *path)
+{
+       int err;
+
+       err = check_path(path);
+       if (err)
+               return err;
+
+       if (map == NULL) {
+               pr_warning("invalid map pointer\n");
+               return -EINVAL;
+       }
+
+       if (bpf_obj_pin(map->fd, path)) {
+               pr_warning("failed to pin map: %s\n", strerror(errno));
+               return -errno;
+       }
+
+       pr_debug("pinned map '%s'\n", path);
+       return 0;
+}
+
 void bpf_object__close(struct bpf_object *obj)
 {
        size_t i;

diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 9f8aa63b95f4e25dad03fcdf3ccd3eecb9f26cc8..2addf9d5b13cdf6d039e2e3a7058a45a9d3a1a83 100644 (file)
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -236,6 +236,7 @@ typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *);
 int bpf_map__set_priv(struct bpf_map *map, void *priv,
                      bpf_map_clear_priv_t clear_priv);
 void *bpf_map__priv(struct bpf_map *map);
+int bpf_map__pin(struct bpf_map *map, const char *path);
 
 long libbpf_get_error(const void *ptr);