Re: [RFC] ipv6: use a random ifid for headerless devices

[Hannes Frederic Sowa <hannes@stressinduktion.org>]

Hello,

On Thu, Dec 3, 2015, at 20:29, Bjørn Mork wrote:
> Hannes Frederic Sowa <hannes@stressinduktion.org> writes:
> 
> > I see no problem with the patch as it eases operating those devices. I
> > would also suggest storing the ifid in the inet6_dev so it does only
> > change during device creation and destruction. Otherwise I would
> > recommend to use stable privacy addresses to generate the link local
> > addresses. EUI-48 based LL creation should hopefully not be used anymore
> > soon.
> 
> Thanks for commenting on this. Yes, the stable privacy addresses looks
> like they will solve this and other problems.  But enabling them require
> an adminstrator action.
> 
> After looking more at addrconf, I started wondering if we couldn't abuse
> ipv6_generate_stable_address() for this purpose?  We could add a new
> addr_gen_mode which would trigger automatic generation of a secret if
> stable_secret is uninitialized.  This would be good enough to ensure
> stability until the interface is destroyed.  And it would still allow
> the adminstrator to select IN6_ADDR_GEN_MODE_STABLE_PRIVACY by entering
> a new secret.

I am fine with your proposal but I would really like to see it only
happen on the per-interface stable_secret instance.

Thanks,
Hannes