cvs commit: src/sys/net if_tap.c

[Roman Kurakin]

John Polstra wrote:

>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_
>  
>
PPP state machine can remove IFF_UP. For example if connection is not 
persistent and link
was broken for any reason.

>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
>  
>
rik