CARP_NL_VERSION
snl_add_msg_attr_u8(&nw, CARP_NL_VERSION, carpr->carpr_version);
{ .type = CARP_NL_VERSION, .off = _OUT(carpr_version), .cb = snl_attr_get_uint8 },
{ .type = CARP_NL_VERSION, .off = _OUT(version), .cb = nlattr_get_uint8 },
nlattr_add_u8(nw, CARP_NL_VERSION, sc->sc_version);