Re: Interface description support

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Mon, Jun 24, 2019 at 04:20:59AM -0700, Jason Thorpe wrote:
> 
> > On Jun 24, 2019, at 12:15 AM, Manuel Bouyer <bouyer%antioche.eu.org@localhost> wrote:
> > 
> > I'd like to see this in NetBSD. I'd also like packet filters to be able
> > to use the description instead of the name for interfaces. This would make
> > my life much easier for e.g. ipfilter in Xen dom0, where the domU's virtual
> > interfaces have unpredicatble names.
> 
> I agree, we should be able to use the description as a means of looking up the interface.  However, because descriptions can be arbitrary, you need to have some rules around them:
> 
> 1- Duplicate descriptions are not allowed (should return EEXIST if an attempt is made to set a duplicate).

Sure

> 
> 2- In order to prevent unpredictable behavior in the presence of name-"wm0" and description-"wm0" being associated with different interfaces, the hardware name should always take priority when looking up an interface.

I'd say that we should explicitely mention if we're looking up a name or
a description, to avoid confusion. For example if wm0 has descrition
"external if" we should be able to write in ipf:

block in on wm0 from any to any
or
block in on intf_desc "external if" from any to any

Same with netstat:
netstat -I wm0
netstat -D "external if"

and so on ...

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--