cvs commit: src/sys/net if_tap.c

[John Polstra]

On 11-Aug-2004 Brian Fundakowski Feldman wrote:
> On Wed, Aug 11, 2004 at 03:33:25AM +0200, Max Laier wrote:
>> On Wednesday 11 August 2004 02:12, Maksim Yevmenkin wrote:
>> > emax        2004-08-11 00:12:27 UTC
>> >
>> >   FreeBSD src repository
>> >
>> >   Modified files:
>> >     sys/net              if_tap.c
>> >   Log:
>> >   Set IFF_RUNNING flag on the interface as soon as the control device is
>> > opened.
>> 
>> Erm ...
>> 1) IFF_RUNNING has a different meaning (for all I know) - "resources 
>> allocated" i.e. address(es) assigned. See if_loop.c for instance.
>> 2) What are these spl's for? You are not going to MFC that anyway as it would 
>> be user visible.
>> 
>> I recon a thread with this topic, but I think the outcome was that this is not 
>> a good thing to do. Can't find the thread though.
> 
> Having written a driver recently, the best I could find is that IFF_RUNNING
> essentially means not dead...

That's pretty much correct.  IFF_UP is an administrative control
that expresses the desired state of the interface.  The driver never
changes IFF_UP.  IFF_RUNNING is the driver's idea of the _actual_
state.  The driver changes IFF_RUNNING in response to changes in
IFF_UP, or in response to error conditions that make the driver unable
to function.

Neither IFF_UP nor IFF_RUNNING have anything at all to do with whether
any addresses are assigned to the interface.

John