Re: [RFC] longer netdev names proposal

[Jiri Pirko <jiri@resnulli.us>]

Fri, Jun 28, 2019 at 03:14:01PM CEST, andrew@lunn.ch wrote:
>On Fri, Jun 28, 2019 at 01:12:16PM +0200, Jiri Pirko wrote:
>> Thu, Jun 27, 2019 at 09:20:41PM CEST, stephen@networkplumber.org wrote:
>> >On Thu, 27 Jun 2019 20:39:48 +0200
>> >Michal Kubecek <mkubecek@suse.cz> wrote:
>> >
>> >> > 
>> >> > $ ip li set dev enp3s0 alias "Onboard Ethernet"
>> >> > # ip link show "Onboard Ethernet"
>> >> > Device "Onboard Ethernet" does not exist.
>> >> > 
>> >> > So it does not really appear to be an alias, it is a label. To be
>> >> > truly useful, it needs to be more than a label, it needs to be a real
>> >> > alias which you can use.  
>> >> 
>> >> That's exactly what I meant: to be really useful, one should be able to
>> >> use the alias(es) for setting device options, for adding routes, in
>> >> netfilter rules etc.
>> >> 
>> >> Michal
>> >
>> >The kernel doesn't enforce uniqueness of alias.
>> >Also current kernel RTM_GETLINK doesn't do filter by alias (easily fixed).
>> >
>> >If it did, then handling it in iproute would be something like:
>> 
>> I think that it is desired for kernel to work with "real alias" as a
>> handle. Userspace could either pass ifindex, IFLA_NAME or "real alias".
>> Userspace mapping like you did here might be perhaps okay for iproute2,
>> but I think that we need something and easy to use for all.
>> 
>> Let's call it "altname". Get would return:
>> 
>> IFLA_NAME  eth0
>> IFLA_ALT_NAME_LIST
>>    IFLA_ALT_NAME  eth0
>>    IFLA_ALT_NAME  somethingelse
>>    IFLA_ALT_NAME  somenamethatisreallylong
>
>Hi Jiri
>
>What is your user case for having multiple IFLA_ALT_NAME for the same
>IFLA_NAME?

I don't know about specific usecase for having more. Perhaps Michal
does.

From the implementation perspective it is handy to have the ifname as
the first alt name in kernel, so the userspace would just pass
IFLA_ALT_NAME always. Also for avoiding name collisions etc.



>
>	Thanks
>		Andrew
>