NLSE_ATTR_DATA
{ .type = NLSE_ATTR_DATA, .off = _OUT(data), .cb = snl_attr_get_string },
nlattr_add_string(&nw, NLSE_ATTR_DATA, data);
{ .type = NLSE_ATTR_DATA, .off = _OUT(data), .cb = snl_attr_get_string },
{ .type = NLSE_ATTR_DATA, .off = _OUT(data), .cb = snl_attr_get_string },