PF_RAT_SRC_PORT
snl_add_msg_attr_u16(nw, PF_RAT_SRC_PORT, addr->port[0]);
{ .type = PF_RAT_SRC_PORT, .off = _OUT(port[0]), .cb = snl_attr_get_uint16 },
{ .type = PF_RAT_SRC_PORT, .off = _OUT(port[0]), .cb = nlattr_get_uint16 },
nlattr_add_u16(nw, PF_RAT_SRC_PORT, r->port[0]);