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Re: [EXTERNAL] Re: Feature request: provide ability to set a global callback function telling libcurl if IPv6 works on the system

From: Dan Fandrich via curl-library <>
Date: Wed, 21 Sep 2022 13:52:56 -0700

On Wed, Sep 21, 2022 at 08:19:46PM +0000, Dmitry Karpov via curl-library wrote:
> Daniel's PR fixed the issue only for CURL_IPRESOLVE_V4, but not for CURL_IPRESOLVE_WHATEVER and CURL_IPRESOLVE_IPV6.
> Even with his PR, both CURL_IPRESOLVE_WHATEVER and CURL_IPRESOLVE_IPV6 will use Curl_ipv6works() and thus face regressions.

I find many of your messages too vague, and I can't tell any more what
exactly are the specific problems that you're still having. They're
using terms like "regressions" and "problem" but I can't tell any more
if you're referring to the 30 msec delay during Curl_ipv6works() or if
there are other issues you're seeing. Is that what you're referring to
in all cases?

> Before Daniel's PR, the problem was for all three resolve modes:
> After his PR, the problem remains for two modes:

If Curl_ipv6works() were not called in the CURL_IPRESOLVE_V6 case, would
that solve the issues that are remaining?

> My proposal, in addition to Daniel's PR allows to close the gap and avoid connection regressions for all three modes.

It might in your situation, but it wouldn't in everybody else's.

Received on 2022-09-21