int nl_sock_recv(struct nl_sock *, struct ofpbuf **, bool wait);
int nl_sock_transact(struct nl_sock *, const struct ofpbuf *request,
struct ofpbuf **reply);
int nl_sock_recv(struct nl_sock *, struct ofpbuf **, bool wait);
int nl_sock_transact(struct nl_sock *, const struct ofpbuf *request,
struct ofpbuf **reply);