* On success, if 'key' and 'key_len' are nonnull then '*key' and
* '*key_len' must be set to Netlink attributes with types ODP_KEY_ATTR_*
* representing the dumped flow's key. If 'actions' and 'actions_len' are
* On success, if 'key' and 'key_len' are nonnull then '*key' and
* '*key_len' must be set to Netlink attributes with types ODP_KEY_ATTR_*
* representing the dumped flow's key. If 'actions' and 'actions_len' are