in windows if my wifi only support ipv4 "localhost" dns only return ipv4 !

[patterniha]

Integrity requirements

• I confirm that I have read the documentation, understand the meaning of all the configuration items I wrote, and did not pile up seemingly useful options or default values.
• I provided the complete config and logs, rather than just providing the truncated parts based on my own judgment.
• I searched issues and did not find any similar issues.
• The problem can be successfully reproduced in the latest Release

Description

#4302 fixed by #4303
but still another problem for windows:

in windows if my wifi only support ipv4, "localhost" dns, only return "ipv4" even if queryStrategy is UseIP!

but in linux it doesn't matter your wifi support ipv6 or not and correctly return ip version base on queryStrategy.
so in linux even if your wifi only support ipv4, "localhost" dns return both ipv4 and ipv6 if queryStrategy is UseIP.

this problem does not exist for other types of dns (udp,tcp,doh,...)

[Fangliding]

report to go

[patterniha]

report to go

i submit this to go.
golang/go#71340

"localhost" dns use net.LookupIP(in features/dns/localdns/client.go) and net.LookupIP incorrectly only return IPv4.

the problem is because windows-release is builded by go with "cgo resolver" instead of "go resolver".

the problem with cgo resolver is that on windows with IPv4 only network, it returns only ipv4
but we may need returned IPs for proxy that support IPv6, so we need IPv6 too.

according to https://pkg.go.dev/net#hdr-Name_Resolution another problem with cgo resolver is that it consumes an operating system thread while go resolver consumes only a goroutine.

why cgo resolver preferred over go resolver in windows-release?

update: I submit this as a new issue.