Re: [RFC] longer netdev names proposal

[Jiri Pirko <jiri@resnulli.us>]

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

then userspace would pass with a request (get/set/del):
IFLA_ALT_NAME eth0/somethingelse/somenamethatisreallylong
or
IFLA_NAME eth0 if it is talking with older kernel

Then following would do exactly the same:
ip link set eth0 addr 11:22:33:44:55:66
ip link set somethingelse addr 11:22:33:44:55:66
ip link set somenamethatisreallylong addr 11:22:33:44:55:66

We would have to figure out the iproute2 iface to add/del altnames:
ip link add eth0 altname somethingelse
ip link del eth0 altname somethingelse
  this might be also:
  ip link del somethingelse altname somethingelse

How does this sound?