Source IP for multihomed peer

[Chriztoffer Hansen]

On Fri, 15 Oct 2021 at 04:39, Benda Xu <heroxbd at gentoo.org> wrote:
> > From the documentation Listenport only seems like the portnumber and
> > there seems to be no way to set the source ip.
>
> It has been discussed on the list several times.  But Jason seems not
> convinced of the necessity of address binding.
>
>   https://lists.zx2c4.com/pipermail/wireguard/2017-May/001280.html
>   https://lists.zx2c4.com/pipermail/wireguard/2019-March/003938.html
>   https://lists.zx2c4.com/pipermail/wireguard/2018-June/003013.html
>   https://lists.zx2c4.com/pipermail/wireguard/2017-November/002017.html
>
> Rulin and I tried to implement an address binding feature at,
>
>   https://github.com/FireflyTang/linux-wireguard-bind
>
> It was verified to work with Linux-5.7.

In the prototyping patch you developed for WireGuard, did you consider
prototyping being able to bind to an interface, instead of explicitly
specifying an IP address? An example case for being able to bind to an
interface could be a multi-wan connected firewall/router with dynamic
public IP addresses offered by the upstream provider no at least one
connection. E.g. Primary fiber line, backup DSL line.

/Chriztoffer