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Re: Specifying names for tap interfaces

Christos Zoulas wrote:
On Jul 5,  3:05pm, (Roger Pau Monne) wrote:
-- Subject: Re: Specifying names for tap interfaces

|>  Yes, that's nice, but purely cosmetic.
| It allows users to have persistent interfaces, even after Dom0/DomU
| reboot, so you can for example graph the traffic a single guest is
| using, which is not possible now.

You could do the same if you assign a numeric range for them that is
high enough that will not be re-used. I would also like to mention,
that the patch is not as simple as presented. Although I have not read
it carefully, it does not seem to prevent name re-use, so one could
potentially rename an interface to an existing name, lo0 for example
and cause all kinds of lossage.

It is not possible to change the name of an interface to an existing one, because of this check, this prevents collusion:

if (ifunit(new_name) != NULL)
        return EEXIST;

But a user could do:

ifconfig bnx0 name tmp
ifconfig bnx1 name bnx0
ifconfig tmp name bnx1

Effectively swapping the name of both interfaces.

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