[v6ops] gai_wrap.py

Brian E Carpenter <brian.e.carpenter@gmail.com> Mon, 16 May 2022 04:39 UTC

To: IPv6 Operations <v6ops@ietf.org>
From: Brian E Carpenter <brian.e.carpenter@gmail.com>
Message-ID: <a00b74d1-a483-997d-1812-49ddeb58311a@gmail.com>
Date: Mon, 16 May 2022 16:39:37 +1200
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.10.0
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"; format="flowed"
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Archived-At: <https://mailarchive.ietf.org/arch/msg/v6ops/W1-I0RDb3F2F5B8CEx_bpYsXdRk>
Subject: [v6ops] gai_wrap.py
Precedence: list

Another toy for ULA users, but only for those coding in Python.

This module provides a wrapper for getaddrinfo(). It does
*exactly* what getaddrinfo() normally does, but it re-sorts
the answers to achieve the same result as indicated by
RFC 6724 section 10.6, *regardless* of the settings in
the host operating system.

To do this, it determines and caches any ULA /48 prefixes
in which the host has at least one address configured;
the cache will be refreshed if more than 60 seconds old.

(Yes, this assumes that if a host has a ULA address, the
corresponding /48 is alive and well.)

Tested on Windows 10 and Linux 5.4.0.

https://github.com/becarpenter/misc/blob/main/gai_wrap.py

Put it in your Python path and do "from gai_wrap import getaddrinfo"

Bugs and comments welcome.

Regards
    Brian Carpenter

[v6ops] gai_wrap.py Brian E Carpenter