Re: [patch net-next rfc 3/7] net: rtnetlink: add commands to add and delete alternative ifnames

[Jiri Pirko <jiri@resnulli.us>]

Fri, Aug 09, 2019 at 06:14:03PM CEST, dsahern@gmail.com wrote:
>On 8/9/19 9:40 AM, Roopa Prabhu wrote:
>>>>> diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h
>>>>> index ce2a623abb75..b36cfd83eb76 100644
>>>>> --- a/include/uapi/linux/rtnetlink.h
>>>>> +++ b/include/uapi/linux/rtnetlink.h
>>>>> @@ -164,6 +164,13 @@ enum {
>>>>>         RTM_GETNEXTHOP,
>>>>>  #define RTM_GETNEXTHOP RTM_GETNEXTHOP
>>>>>
>>>>> +       RTM_NEWALTIFNAME = 108,
>>>>> +#define RTM_NEWALTIFNAME       RTM_NEWALTIFNAME
>>>>> +       RTM_DELALTIFNAME,
>>>>> +#define RTM_DELALTIFNAME       RTM_DELALTIFNAME
>>>>> +       RTM_GETALTIFNAME,
>>>>> +#define RTM_GETALTIFNAME       RTM_GETALTIFNAME
>>>>> +
>>>>
>>>> I might have missed the prior discussion, why do we need new commands
>>>> ?. can't this simply be part of RTM_*LINK and we use RTM_SETLINK to
>>>> set alternate names ?
>>>
>>> How? This is to add/remove. How do you suggest to to add/remove by
>>> setlink?
>> 
>> to that point, I am also not sure why we have a new API For multiple
>> names. I mean why support more than two names  (existing old name and
>> a new name to remove the length limitation) ?
>> 
>> Your patch series addresses a very important problem (we run into this
>> limitation all  the time and its hard to explain it to network
>> operators) and
>>  its already unfortunate that we have to have more than one name
>> because we cannot resize the existing one.
>> 
>> The best we can do for simpler transition/management from user-space
>> is to keep the api simple..
>> ie keep it close to the management of existing link attributes. Hence
>> the question.
>> 
>> I assumed this would be like alias. A single new field that can be
>> referenced in lieu of the old one.
>> 
>> Your series is very useful to many of us...but when i think about
>> changing our network manager to accommodate this, I am worried about
>> how many apps will have to change.
>> I agree they have to change regardless but now they will have to
>> listen to yet another notification and msg format for names ?
>> 
>> (apologies for joining the thread late and if i missed prior discussion on this)
>
>I agree with Roopa. I do not understand why new RTM commands are needed.
>The existing IFLA + ifinfomsg struct give more than enough ways to id
>the device for adding / deleting an alternate name.
>

Could you please write me an example message of add/remove?