Maybe we should only do Happy Eyeballs when IPv6 is preferred?

in v2rayNG, and for proxy-outbound, happy eyeballs only operates when Outbound domain pre-solve method is Resolve and add to DNS Hosts.

domainStrategy should always be UseIP regardless of Prefer IPv6.

if Prefer IPv6 is true, set prioritizeIPv6 to true, otherwise false.

set tryDelayMs to 250 and let interleave and maxConcurrentTry be the default values( 1 and 4)

in v2rayNG, and for proxy-outbound, happy eyeballs only operates when Outbound domain pre-solve method is Resolve and add to DNS Hosts.

domainStrategy should always be UseIP regardless of Prefer IPv6.

if Prefer IPv6 is true, set prioritizeIPv6 to true, otherwise false.

set tryDelayMs to 250 and let interleave and maxConcurrentTry be the default values( 1 and 4)

Thank you. I implemented prioritizeIPv6 so that when prefer IPv6 is enabled, it’s set to true and the interleave is set to 2, which makes it check two IPs of the selected version first (either IPv4 or IPv6).
As far as I’ve checked, this config seems to work properly.

domainStrategy should always be UseIP regardless of Prefer IPv6.

where is it?

without setting domainStrategy to UseIP, Resolve and add to DNS Hosts mode does not apply at all.

in AsIs mode, golang-happy-eyeballs is applied, This is because your test was successful, but this is for Do not resolve mode.

where is it?

You were right.
V2rayng also resolve and add to DNS hosts :

  "dns": {
    "hosts": {
      "currentConfig.com": [
        "3a2a:**",
        "1.2.3.4"
      ]
    },
}

@hossinasaadi

@DHR60 is right, you should replace item.ensureSockopt().domainStrategy = if (preferIpv6) "UseIPv6v4" else "UseIPv4v6" with item.ensureSockopt().domainStrategy = "UseIP" in the same line.

emm，我的意思是 resolvedIps.isNullOrEmpty() == true 时的 bug

要么

            if (newHosts.containsKey(domain)) {
                item.ensureSockopt().domainStrategy = "UseIP"
                item.ensureSockopt().happyEyeballs = StreamSettingsBean.happyEyeballsBean(
                    prioritizeIPv6 = preferIpv6,
                    interleave = 2
                )
                continue
            }

            val resolvedIps = HttpUtil.resolveHostToIP(domain, preferIpv6)
            if (resolvedIps.isNullOrEmpty()) continue

            item.ensureSockopt().domainStrategy = "UseIP"
            item.ensureSockopt().happyEyeballs = StreamSettingsBean.happyEyeballsBean(
                prioritizeIPv6 = preferIpv6,
                interleave = 2
            )

要么

if (resolvedIps.isNullOrEmpty()) {
    item.ensureSockopt().domainStrategy = null
    continue
}

不处理会导致 DNS 回环

当然，如果你认为这个错误不可能触发，删掉 if (resolvedIps.isNullOrEmpty()) continue 这个处理就行

@hossinasaadi

@DHR60 is right, you should replace item.ensureSockopt().domainStrategy = if (preferIpv6) "UseIPv6v4" else "UseIPv4v6" with item.ensureSockopt().domainStrategy = "UseIP" in the same line.

I see, you think we can handle it from core? XTLS/Xray-core#5022

emm, I mean the bug when resolvedIps.isNullOrEmpty() == true

or

            if (newHosts.containsKey(domain)) {
                item.ensureSockopt().domainStrategy = "UseIP"
                item.ensureSockopt().happyEyeballs = StreamSettingsBean.happyEyeballsBean(
                    prioritizeIPv6 = preferIpv6,
                    interleave = 2
                )
                continue
            }

            val resolvedIps = HttpUtil.resolveHostToIP(domain, preferIpv6)
            if (resolvedIps.isNullOrEmpty()) continue

            item.ensureSockopt().domainStrategy = "UseIP"
            item.ensureSockopt().happyEyeballs = StreamSettingsBean.happyEyeballsBean(
                prioritizeIPv6 = preferIpv6,
                interleave = 2
            )

or

if (resolvedIps.isNullOrEmpty()) {
    item.ensureSockopt().domainStrategy = null
    continue
}

Failure to handle this will result in a DNS loop.

?
both of these codes are correct, I said the same thing.

حسین ایرانی دیگه؟ مشکلت چیه؟

? both of these codes are correct, I said the same thing.

看成 replace A to B 了

I think some things are mixed up, we also have useSystem dns-queryStrategy.

حسین ایرانی دیگه؟ مشکلت چیه؟

اره.الان باید مشکل حل شده باشه

@DHR60

I think it is okay now.

没有使用过 happyEyeballs ，请问在真实环境下能有什么优势？

I have never used happyEyeballs. What advantages does it have in a real environment?

XTLS/Xray-core#4667

for example suppose our IP-list is [ip4-1, ip4-2, ip4-3, ip4-4, ip6-1, ip6-2, ip6-3, ip6-4]

when interleave is 1 and prioritizeIPv6 is false, the sorted-ip-list is:
[ip4-1, ip6-1, ip4-2, ip6-2, ip4-3, ip6-3, ip4-4, ip6-4]

and when for example interleave is 2 and prioritizeIPv6 is true:
[ip6-1, ip6-2, ip4-1, ip4-2, ip6-3, ip6-4, ip4-3, ip4-4]

then delay 250ms for each attempt until first connection is established.

the first-stablished-connection is winner connection and selected for sending/receiving data.

when we have multiple-IP, this causes a race between ips and it tries to find to the first IP that can be connected.

so it solve ipv4/ipv6 unreachable problem.

I wrote a full explanation when I implemented it on the core: XTLS/Xray-core#4667

///

also, it only applies when sockopt-domainStrategy is UseIP/ForceIP, and for AsIs mode golang-happy-eyeballs is applied.

you can read Xray-core doc for it : https://xtls.github.io/config/transport.html#sockoptobject

///

Anyway, this PR has used this feature correctly.