PF_RT_GID
snl_add_msg_attr_uid(nw, PF_RT_GID, (const struct pf_rule_uid *)&r->gid);
{ .type = PF_RT_GID, .off = _OUT(r.gid), .arg = &rule_uid_parser, .cb = snl_attr_get_nested },
{ .type = PF_RT_GID, .off = _OUT(gid), .arg = &rule_uid_parser, .cb = nlattr_get_nested },
nlattr_add_rule_uid(nw, PF_RT_GID, (const struct pf_rule_uid *)&rule->gid);