[BUG] 配置 mosdns 对指定范围的双栈域名立即屏蔽 AAAA 解析请求，但并未得到期待的结果 about mosdns

[IceCodeNew]

光是这个问题的话我还能通过升级到 v0.23.0 版本解决，但是就像上面配置文件展示的那样，sequence 路由插件里存在下面这样两个匹配条件：
其中前一个可以改写成 if,if_and,exec,goto 的形式。但是第二个因为需要先尝试解析一次，才能匹配第二个匹配条件（if(response_has_bogus_ip)），因此只能写成 if,exec,if,exec,go 的形式。
这是我为什么要提出这个 issue 的主要原因，因为从结果来看我目前的这个写法根本不起效果。

        - if:
            - query_is_non_local_domain
          exec:
            - forward_nextdns
            - if:
                - match_aaaa
              exec:
                - _drop_response
          goto: _end

和

        - if:
            - query_is_local_domain
          exec:
            - with_fallback_cn_dns_serv
            - if:
                - response_has_bogus_ip
              exec:
                - _drop_response
          goto: _end

[IrineSistiana]

看 debug log。match_aaaa 返回了什么 ？

[IrineSistiana]

没理解你的问题。是 match_aaaa 没生效，还是什么?

[IceCodeNew]

看 debug log。match_aaaa 返回了什么 ？

日志完全没有有用的信息，不然我一开始就会提供了。
下面是日志级别设置到 debug 级别的输出，我把整个目录复制了一份，调整了一下监听的端口复现问题。所以日志显示第一次启动失败了，但是除此以外就没有任何可以指示问题的输出。

time="2021-01-03T16:31:51+08:00" level=info msg="loading plugin my_server"
time="2021-01-03T16:31:51+08:00" level=info msg="loading plugin main_pipeline"
time="2021-01-03T16:31:51+08:00" level=info msg="loading plugin main_sequence"
time="2021-01-03T16:31:51+08:00" level=info msg="loading plugin cloak_hosts"
time="2021-01-03T16:31:51+08:00" level=info msg="loading plugin set_ecs"
time="2021-01-03T16:31:51+08:00" level=info msg="loading plugin with_fallback_cn_dns_serv"
time="2021-01-03T16:31:51+08:00" level=info msg="loading plugin plain_req_pku_and_tuna"
time="2021-01-03T16:31:51+08:00" level=info msg="loading plugin forward_ali_and_tx"
time="2021-01-03T16:31:51+08:00" level=info msg="loading plugin forward_nextdns"
time="2021-01-03T16:31:51+08:00" level=info msg="loading plugin query_is_local_domain"
time="2021-01-03T16:31:51+08:00" level=fatal msg="plugin my_server reported a fatal err: server exited with err: listen tcp 127.0.0.1:3000: bind: Only one usage of each socket address (protocol/network address/port) is normally permitted."
time="2021-01-03T16:32:09+08:00" level=info msg="loading plugin my_server"
time="2021-01-03T16:32:09+08:00" level=info msg="loading plugin main_pipeline"
time="2021-01-03T16:32:09+08:00" level=info msg="loading plugin main_sequence"
time="2021-01-03T16:32:09+08:00" level=info msg="loading plugin cloak_hosts"
time="2021-01-03T16:32:09+08:00" level=info msg="loading plugin set_ecs"
time="2021-01-03T16:32:09+08:00" level=info msg="loading plugin with_fallback_cn_dns_serv"
time="2021-01-03T16:32:09+08:00" level=info msg="loading plugin plain_req_pku_and_tuna"
time="2021-01-03T16:32:09+08:00" level=info msg="loading plugin forward_ali_and_tx"
time="2021-01-03T16:32:09+08:00" level=info msg="loading plugin forward_nextdns"
time="2021-01-03T16:32:09+08:00" level=info msg="loading plugin query_is_local_domain"
time="2021-01-03T16:32:09+08:00" level=info msg="loading plugin query_is_non_local_domain"
time="2021-01-03T16:32:09+08:00" level=info msg="loading plugin query_is_ad_domain"
time="2021-01-03T16:32:09+08:00" level=info msg="loading plugin match_aaaa"
time="2021-01-03T16:32:09+08:00" level=info msg="loading plugin response_has_bogus_ip"
time="2021-01-03T16:32:09+08:00" level=info msg="all plugins are successfully loaded"
time="2021-01-03T16:32:09+08:00" level=debug msg="loaded plugins: [_block_with_servfail _query_is_common my_server _default_cache _drop_response _block_with_nxdomain _end with_fallback_cn_dns_serv plain_req_pku_and_tuna query_is_non_local_domain match_aaaa _no_ecs _qtype_A_AAAA _response_rcode_success main_pipeline main_sequence query_is_local_domain response_has_bogus_ip my_logger cloak_hosts set_ecs forward_ali_and_tx forward_nextdns query_is_ad_domain]"
time="2021-01-03T16:32:24+08:00" level=debug msg="HeapObjects: 446609 NumGC: 6 PauseTotalNs: 1016900, NumGoroutine: 9"
time="2021-01-03T16:32:39+08:00" level=debug msg="HeapObjects: 446628 NumGC: 6 PauseTotalNs: 1016900, NumGoroutine: 9"
time="2021-01-03T16:32:54+08:00" level=debug msg="HeapObjects: 446648 NumGC: 6 PauseTotalNs: 1016900, NumGoroutine: 9"
time="2021-01-03T16:33:09+08:00" level=debug msg="HeapObjects: 446674 NumGC: 6 PauseTotalNs: 1016900, NumGoroutine: 9"

---

没理解你的问题。是 match_aaaa 没生效，还是什么?

是的，感觉 match_aaaa 没生效，因为我几乎可以肯定域名解析过程中进入了 non_local_domain 的分支，但是对 www.facebook.com 解析返回了 IPv6 地址。

[IrineSistiana]

你确定你的请求是 mosdns 处理的么.....

不管怎么样，只要收到请求，mosdns 就有 log 的，不可能漏。

[IceCodeNew]

你确定你的请求是 mosdns 处理的么.....

不管怎么样，只要收到请求，mosdns 就有 log 的，不可能漏。

那确实很奇怪……我吸取上次的教训，这次是开了 ps 以后打开 nslookup 测试的。

nslookup

> set port=5454
> set server=127.0.0.2
> set type=a+aaaa
> www.facebook.com

[IceCodeNew]

重启解决问题了……感觉大概是缓存的锅。