Re: How to tell if a network interface was renamed (and from what)

From: Mina_Galić <freebsd_at_igalic.co>
Date: Sun, 19 Nov 2023 21:35:03 UTC
Hi Zhenlei,


> Since it is just for physical devices, may I propose to have the driver name in their groups ?
> 
> So an if_ure interface ue0 will look like:
> 
> ```
> ue0: flags=1008843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1500
> 
> options=60009b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,RXCSUM_IPV6,TXCSUM_IPV6>
> 
> ether 00:e0:4c:xx:xx:xx
> media: Ethernet autoselect (1000baseT <full-duplex>)
> 
> status: active
> +++ groups: ure
> nd6 options=23<PERFORMNUD,ACCEPT_RTADV,AUTO_LINKLOCAL>
> 
> ```
> 
> That does not include the unit number. But could be useful to quickly get the driver name of physical devices.
>

Given that currently on FreeBSD the easiest way to tell if something
is a physical device is by checking the *absence* of groups, this
would only really be acceptable if we add an "egress" group like
OpenBSD does, in addition to the driver name.

If we can't do that, then I think Mike's solution with having the
driver (and unit) as a separate category would be preferable.

Unrelatedly, I don't see anything in ure(4) mentioning that if_ure
devices will be named "ue".
Don't we usually  document such deviation from the norm?


Kind regards,

Mina