shadowsocks
Add local response to ICMP PING requests (IPv4 & IPv6)
@Mygod 比如 https://t.me/projectXray/424048
此外，实测 Netch 是本地响应 ping，@Dreamacro 说 Clash 也是本地响应 ping，我认为他们的做法具有参考意义，毕竟 ping 全丢是有些奇怪的事情，加个本地响应并不多余，可以减少一些非预期情况、解决一些潜在的问题
我使用的是 XTLS 的版本，这是一个礼貌性 PR，看你们是否需要了
@madeye
根据原有代码，添加了 #define IPV4_PROTOCOL_ICMP 1 和 #define IPV6_NEXT_ICMP 58；ping 和 ping6 那两段需要保持 hard code，因为它们与其 response 的差值决定了响应的 checksum 的快速算法，需要体现出来，且只有这里的代码在解析 ICMP，原有代码对这种情况也是 hard code
If I understand correctly, does this respond to every single ping packet to every IP address? This is very confusing behavior and possibly a fingerprint for the VPN.
It is common for firewalls to block all ping traffic so no modern apps should ever expect ping to work.
@Mygod
Well, my points are already clear above.
- And I don't see this behavior a fingerprint for the VPN, because it's not hard for an APP to find itself being proxied.
- It's definitely not common for firewalls to block all ping traffic. And you can't define what modern apps should do.
- But indeed we can make apps believe target's accessible whenever they want to ping, it's an access tool, after all.
It makes me feel better to see ping's available in Termux when I use v2rayNG, and it's beautiful, rather than no response. I believe Clash and Netch feel the same. So if you don't need this PR, you can just close it. At last, I respect @madeye's decision.
