Re: link-state change for virtual interfaces

On 2024/09/25 20:08, Valery Ushakov wrote:
> On Wed, Sep 25, 2024 at 10:32:18 +0900, Rin Okuyama wrote:
> 
>> Recently, link-state emulation has been added to shmif(4) and
>> vether(4). Unfortunately, different operations are required for
>> link-up/down for these interfaces:
>>
>> For shmif(4)
>> - link-up:   ifconfig shmif%d media auto
>> - link-down: ifconfig shmif%d media none
>>
>> https://mail-index.netbsd.org/source-changes/2024/08/20/msg152934.html
>> https://mail-index.netbsd.org/source-changes/2024/08/20/msg152935.html
>>
>> For vether(4)
>> - link-up:   ifconfig vether%d link1
>> - link-down: ifconfig vether%d -link1
>>
>> https://mail-index.netbsd.org/source-changes/2024/09/24/msg153517.html
>> https://mail-index.netbsd.org/source-changes/2024/09/24/msg153525.html
>>
>> Wouldn't it be better to unify as far as possible? If so,
>> which one is more preferable? (The 3rd candidate may be
>> to add dedicated flag bit, but it seems too much to me.)
> 
> "Pluggin" and "unplugging" the media, like shmif does, seems like an
> interesting metaphor.  How is it reflected in ifconfig output?
> I.e. what does
> 
>    $ ifconfig $shmif
> 
> show for "media: ..." in both states?

Yeah, interesting :) Here's ifconfig output:

````
# rump.ifconfig shmif0 media auto
# rump.ifconfig shmif0
shmif0: flags=0x8802<BROADCAST,SIMPLEX,MULTICAST> mtu 1500
   capabilities=0x7ff80<TSO4,IP4CSUM_Rx,IP4CSUM_Tx,TCP4CSUM_Rx>
   capabilities=0x7ff80<TCP4CSUM_Tx,UDP4CSUM_Rx,UDP4CSUM_Tx,TCP6CSUM_Rx>
   capabilities=0x7ff80<TCP6CSUM_Tx,UDP6CSUM_Rx,UDP6CSUM_Tx,TSO6>
   enabled=0
   address: b2:a0:01:9d:82:a5
   linkstr: bus1
   media: Ethernet autoselect
# rump.ifconfig shmif0 media none
# rump.ifconfig shmif0
shmif0: flags=0x8802<BROADCAST,SIMPLEX,MULTICAST> mtu 1500
   capabilities=0x7ff80<TSO4,IP4CSUM_Rx,IP4CSUM_Tx,TCP4CSUM_Rx>
   capabilities=0x7ff80<TCP4CSUM_Tx,UDP4CSUM_Rx,UDP4CSUM_Tx,TCP6CSUM_Rx>
   capabilities=0x7ff80<TCP6CSUM_Tx,UDP6CSUM_Rx,UDP6CSUM_Tx,TSO6>
   enabled=0
   address: b2:a0:6b:44:5b:bd
   linkstr: bus1
   media: Ethernet none
````

If `-v` option is specified to ifconfig,
   linkstate: up
and
   linkstate: down
appear b/w linkstr and media lines. This should happen also for vether:

https://mail-index.netbsd.org/source-changes/2024/08/20/msg152936.html

Thanks,
rin

> 
> -uwe
>