FreeBSD if_wg POINTTOPOINT and MULTICAST behaviour

[Toke Høiland-Jørgensen]

Stefan Haller <stefan.haller at stha.de> writes:

> Hi Jason,
>
> On Thu, Apr 15, 2021 at 06:05:03PM -0600, Jason A. Donenfeld wrote:
>> I spent the day playing around with bird and babel and sorted out
>> FreeBSD's v6 situation. Basically, ff00::/8 addresses are treated
>> differently, and they're blocked unless the interface sets
>> IFF_MULTICAST. So I've committed
>> https://git.zx2c4.com/wireguard-freebsd/commit/?id=a7a84a17faf784857f076e37aa4818f6b6c12a95
>> to do this.
>
> That is also what I observed. Without IFF_MULTICAST I see the following
> error in bird's log:
>
> bird[8045]: babel1: Socket error: IPV6_MULTICAST_IF: Can't assign requested address
> bird[8045]: babel1: Cannot open socket for wg1
>
>> Stefan - please let me know if those work for you. In my testing thus
>> far, things seem to work for me.
>
> After applying Toke's patch for bird and your Wireguard patch in
> a7a84a17faf784 everything is working as before (with minor config
> changes).
>
> Just for the record, my previous configuration looked like this (using
> POINTTOPOINT interfaces, I use ifconfig to set the peer address):
>
>> [Interface]
>> ...
>> Address = fe80::5/64
>> PostUp = ifconfig %i inet 169.254.42.5/32 169.254.42.2
>
> My new configuration without POINTTOPOINT, but only a single peer
> directly attached to other side of the wg tunnel:
>
>> [Interface]
>> ...
>> Address = 169.254.42.5/32, fe80::5/64
>> PostUp = route add 169.254.42.2 -iface %i
>
> So for me everything works as expected again. A big thanks to all of you for
> figuring out what was going wrong and getting it fixed so quickly.

Great! You're welcome :)

-Toke