http/https modules should fallback to IPv4 when IPv6 connection fails

[cuihaoleo]

Version

v17.6.0

Platform

Linux cvhc-tomato 5.16.13-zen1-1-zen #1 ZEN SMP PREEMPT Tue, 08 Mar 2022 20:07:38 +0000 x86_64 GNU/Linux

Subsystem

No response

What steps will reproduce the bug?

We use a IPv4/v6 dual-stack network. For some reason, we blocked some IPv6 ranges, including Google's, on our gateway. It returns "Address unreachable" for any access to these IPv6 ranges.

Usually HTTP clients fallback to IPv4 when v6 fails so the blocking doesn't prevent them from accessing Google. At least this is true for browsers, curl/wget and Python HTTP libraries.

But nodejs's HTTP(s) modules don't behave the same way. The following code:

http = require('http');
http.get("http://www.google.com").on("error", (e) => {console.log(e)});

will ends up with an error.

How often does it reproduce? Is there a required condition?

No response

What is the expected behavior?

No response

What do you see instead?

> Error: connect EHOSTUNREACH 2607:f8b0:4007:80a::2004:80
    at TCPConnectWrap.afterConnect [as oncomplete] (node:net:1158:16)
    at TCPConnectWrap.callbackTrampoline (node:internal/async_hooks:130:17) {
  errno: -113,
  code: 'EHOSTUNREACH',
  syscall: 'connect',
  address: '2607:f8b0:4007:80a::2004',
  port: 80
}

Additional information

Is it possible to change the behavior so that nodejs's HTTP(s) modules fallback to IPv4 when IPv6 connect fails, like other HTTP clients?

[Trott]

Duplicate of #41625.