PF_RT_NR
snl_add_msg_attr_u32(nw, PF_RT_NR, r->nr);
{ .type = PF_RT_NR, .off = _OUT(r.nr), .cb = snl_attr_get_uint32 },
{ .type = PF_RT_NR, .off = _OUT(nr), .cb = nlattr_get_uint32 },
nlattr_add_u32(nw, PF_RT_NR, rule->nr);