[FFmpeg-devel] [PATCH v2] avformat: enable UDP IPv6 multicast interface selection using zone index

Lynne dev at lynne.ee
Mon Apr 29 15:03:39 EEST 2024


Apr 29, 2024, 13:34 by remi at remlab.net:

>
>
> Le 29 avril 2024 13:32:41 GMT+03:00, Lynne <dev at lynne.ee> a écrit :
> >Apr 29, 2024, 11:56 by remi at remlab.net:
>
>>>
>>>
>>> Le 29 avril 2024 11:20:24 GMT+03:00, Lynne <dev at lynne.ee> a écrit :
>>>
>>>>> >They were they deprecated?
>>>>>
>>>>> They caused more bugs than they solved problems (because what we need is to add IPv6 to IPv4 apps, not IPv4 to IPv6 apps).
>>>>>
>>> >What bugs did they cause?
>>>
>>> Obviously anything that assumes IPv6 semantics is prone to breaking.
>>>
>>>> i know they're not very well used, because the
>>>>
>>> >documentation is very lacking,
>>>
>>> No, they're not used because they are officially deprecated for 15+ years (see RFC5156).
>>>
> >The RFC says that IPv4-Compatible addresses are deprecated,
> >but doesn't say that about IPv4-Mapped addresses.
>
> Ah, yeah, the case against mapped addresses did not make it to RFC status, likely because the main author tragically died, see draft-itojun-v6ops-v4mapped-harmful.
>

The draft recommends that their use on the wire is forbidden,
which is a niche use-case some vendors did.


> But anyway, I am not a vendor of IP stacks. I am just the messenger here: mapped addresses are not portable and so you should not rely on them in portable code.
>

Fair enough, thanks for looking into it, will keep it in mind that
OpenBSD doesn't implement this yet.
I'm sure IPv4 will be deprecated soon. The Czech government is
so optimistic it announced it'll stop hosting its website under it
in just 8 years from now.


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