IFF_RUNNING and SIOCGMIIPHY support

Jean Tourrilhes jt at bougret.hpl.hp.com
Mon Mar 1 13:23:02 EST 2004


On Sun, Feb 29, 2004 at 01:01:57PM +0000, David Goodenough wrote:
> 
> Mii-tool does no appear to be supported by hostap, and I was wondering
> why.  Obviously the mode makes a difference, so saying that a node in 
> master mode is connected makes little sense, but for a managed or
> ad-hoc mode node the link speed and the presence or absence of an 
> active connection would be useful.

	Actually, ad-hoc mode is like master mode, you can't test the
presence/absence of an active connection (i.e. the connection is
always valid). This is why you would use iwspy and TXDROP in ad-hoc
mode.
	So, this would work only in managed mode.

> As traditionally used yes it is, but a single command line interface that
> means that in a mixed wired/wireless environment I can find out if all
> my links are up would be really useful.  I was thinking of this as a 
> simple human interface for diagnosing problems

	This is irrealistic, wireless does not behave like wired. Your
wireless link may be up, but if you are associate with the wrong
Access Point, it will do you no good. Or, the link may be up but
barely usable because there is too many retries.
	Most people setting up long-haul wireless links have their own
definition of goodness, especially when using ad-hoc mode.

Jouni wrote :
> Isn't mii-tool quite Ethernet-specific? What would be the purpose of
> using it with a wireless driver? I did not notice SIOCGMIIPHY support in
> any of the kernel tree driver for wireless devices.

	I even suspect that mii-tool is deprecated in favor of
ethtool. Some wireless drivers implement the "information" part for
"ethtool -i".

> IFF_RUNNING was always set when the interface was up. Anyway, I have
> been thinking of adding netif_carrier_{on,off}() calls to the driver
> based on the association state and ended up doing it now. The
> development snapshot from the CVS has now code for setting the carrier
> off when in station mode and not associated. This clears the IFF_RUNNING
> flag for user space programs and generates a linkwatch event in the
> kernel.

	As in ad-hoc mode the card is always successfully associated,
IFF_RUNNING would always be set, which is what we want. I believe the
same would apply to master mode. You may want to check what's
happening in monitor mode and WDS.

	Have fun...

	Jean



More information about the HostAP mailing list