bool blobmsg_add_object(struct blob_buf *b, json_object *obj);
bool blobmsg_add_json_element(struct blob_buf *b, const char *name, json_object *obj);
bool blobmsg_add_json_from_string(struct blob_buf *b, const char *str);
+bool blobmsg_add_json_from_file(struct blob_buf *b, const char *file);
typedef const char *(*blobmsg_json_format_t)(void *priv, struct blob_attr *attr);