Re: [exim-dev] Bug 2369: single-key lookup type based on li…

On 24/02/2019 18:11, Ian Zimmerman via Exim-dev wrote:
>> I'd expect conversion to unabbreviated form to have been done too.
>
> Do you mean I can expect an IPv6 address (mapped or not) to have exactly
> 7 separators, whatever these might be? If yes, there is no ambiguity.

That is my hope. But hope is all it is. This is why I say you need to
test. And leave the testcases in the testsuite.

>
> I think I must keep in mind 2 cases:
>
> 1. Addresses coming from exim itself, for example $sender_host_address.
> Unfortunately the spec doesn't say what format this is in (if it is
> IPv6). Can you enlighten me about this?

That specific expansion returns whatever the library inet_ntop()
does. The Linux manpage says, for ipv6, "the most appropriate ...
format". I think that means "abbreviated". It does note that
ipv6-mapped ipv4 addresses are converted to ipv6, which I assume
means "no dotted tail section" (it lists that as a bug, so it could
change sometime).

> 2. Addresses explicitly written into the configuration by user. This
> one is about what I can require from users. I need to document that in
> the experimental documentation file.

I'm hoping it turns out that you can handle all reasonable input
representations with minimal effort, so placing few restrictions
on the user.
--
Cheers,
Jeremy