[avahi] Code review request on PR #306
Philip Prindeville
philipp_subx at redfish-solutions.com
Sat Oct 31 19:20:08 UTC 2020
Still hoping for a review of this relatively trivial PR.
> On Sep 26, 2020, at 11:24 AM, Philip Prindeville <philipp_subx at redfish-solutions.com> wrote:
>
> Hi,
>
> I was reviewing the logic where avahi-daemon requires the multicast bit (IFF_MULTICAST) be set on the interface of point-to-point tunnels, where a point-to-point connection is by definition unicast (in that the packets can only ever go to a single recipient, i.e. the node at the other end of the tunnel).
>
> Seems it’s previously been an issue:
>
> https://lists.freedesktop.org/archives/avahi/2020-May/thread.html#2538
>
> Anyway, the change is trivial:
>
> https://github.com/lathiat/avahi/pull/306
>
> It’s a relatively simple change I was hoping to get reviewed. If the interface is:
>
> (1) loopback OR
> (2) multicast OR
> (3) point-to-point AND allow-point-to-point is enabled
>
> then the interface should be used.
>
> I’ve run both the previous and the current version of the PR in production with GRE-over-IPsec tunnels and both work in those cases.
>
> This patch is useful when you’re using an IPsec manager that doesn’t allow you to customize tunnel bring-up through scripts where you can simply flag the tunnel as “ip link set multicast on dev $IFNAME”… but that, as the original issue suggests, is the wrong mindset. Requiring the multicast flag (i.e. “group delivery” capable) on a point-to-point interface (which is inherently limited to a “group of one”, i.e. not a “group” at all) is thinking about this wrong.
>
> I have a few scenarios where I’m using mDNS in VPN scenarios (where the tunneling protocol of choice is ESP) and this should work transparently.
>
> Thanks,
>
> -Philip
>
> _______________________________________________
> avahi mailing list
> avahi at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/avahi
More information about the avahi
mailing list