Re: [PATCH net-next 1/3] selftests: drv-net: resolve remote interface name

[Jakub Kicinski <kuba@kernel.org>]

On Thu, 13 Feb 2025 15:31:57 +0100 Petr Machata wrote:
> > +    def resolve_remote_ifc(self):
> > +        v4 = v6 = None
> > +        if self.remote_v4:
> > +            v4 = ip("addr show to " + self.remote_v4, json=True, host=self.remote)
> > +        if self.remote_v6:
> > +            v6 = ip("addr show to " + self.remote_v6, json=True, host=self.remote)
> > +        if v4 and v6 and v4[0]["ifname"] != v6[0]["ifname"]:
> > +            raise Exception("Can't resolve remote interface name, v4 and v6 don't match")
> > +        return v6[0]["ifname"] if v6 else v4[0]["ifname"]  
> 
> Is existence of more than one interface with the same IP address a
> concern? I guess such configuration is broken and wouldn't come up in a
> selftest, but consider throwing in an "len(v4) == len(v6) == 1" for
> robustness sake. 

Will do!

> I guess it could in fact replace the "v4 and v6" bit.

Hm, I think that bit has to stay, we only record one interface.
So if v4 and v6 given to the test are on different interfaces
there could be some confusion. Not that we currently validate
the same thing for the local machine..