vfs_fruit: Time Machine/FULLSYNC: add mDNS/DNS-SD advertisement

[Omri Mor]

> On Jul 19, 2017, at 20:46, Ralph Böhme <slow at samba.org> wrote:
> 
> I don't quite remember the details, but iirc we just added adVU support to
> Netatalk to behave exactly like a OS X (back then) server. If it does work without a adVU or
> a fake one that might be ok, but lacking clear documentation and spec I guess
> the safest approach is still to behave exactly like a macOS server.
> 
> Cheerio!
> -slow

> On Jul 19, 2017, at 21:01, Ralph Böhme <slow at samba.org> wrote:
> 
> Please document your findings. We could add it to our Wiki.
> 
> Cheerio!
> -slow

As per the Time Machine over SMB specification, 0x0002 in adVF (AirDiskVolumeFlags) means "SMB is supported on this volume”. The wiki currently lists that as “unknown”.
The wiki also has adVU attached to the sys key, while other sources (and Netatalk itself, if I recall correctly) use it in dkN.
I’ve seen sources with the adVU UUID using both uppercase and lowercase versions—I don’t think it matters, as it should be interpreted as hexadecimal in any case. I just used a randomly generated UUID.
I don’t have macOS Server, so I can’t verify what it uses—my understanding is that it’s primarily a GUI to the underlying system services, which can be used on their own, though they need to be manually set-up.
It seems that only macOS Server uses the 0x0020 flag, with some sources saying that Time Capsules don’t.
There’s also a 0x1000 flag that’s undocumented, but it’s been less commonly used in the wild. It has appeared in both the sys and the dkN keys.
The 0x0100 flag has only ever appeared (and has any effect) in the sys key. 0x0010 has appeared in both.

I don’t suppose Apple would give us some documentation if we asked them really nicely?

Omri