Re: [PATCH 1/2] nl80211: Add LIVE_ADDR_CHANGE feature

[James Prestwood <prestwoj@gmail.com>]

On Fri, 2019-09-13 at 23:01 +0200, Johannes Berg wrote:
> On Fri, 2019-09-13 at 13:56 -0700, James Prestwood wrote:
> > Hi,
> > 
> > On Fri, 2019-09-13 at 22:48 +0200, Johannes Berg wrote:
> > > On Fri, 2019-09-13 at 12:59 -0700, James Prestwood wrote:
> > > > Add a new feature bit signifying that the wireless hardware
> > > > supports
> > > > changing the mac address while the underlying net_device is
> > > > UP.  Note
> > > > that this is slightly different from IFF_LIVE_ADDR_CHANGE as
> > > > additional
> > > > restrictions might be imposed by the hardware.  Typical
> > > > restrictions
> > > > are:
> > > > 	- No connection is active on this interface, e.g.
> > > > carrier is
> > > > off
> > > > 	- No scan is in progress
> > > > 	- No offchannel operation is in progress
> > > 
> > > Hmm, what do you need this patch for?
> > > 
> > > IFF_LIVE_ADDR_CHANGE should be sufficient to discover it?
> > 
> > Because userspace needs to know if this is supported?
> > IFF_LIVE_ADDR_CHANGE is a private flag... AFAIK userspace has no
> > way of
> > obtaining this.
> 
> Oh, annoying.
> 
> But that doesn't really mean that nl80211 is an appropriate place to
> advertise it, IMHO?

The intention of the flag was not soley related to
CMD_CONNECT/CMD_AUTHENTICATE. Its an indication that the
hardware/driver supports a live address change. If you don't want it
here could you suggest a better location for it?

> 
> And in nl80211 you'd need the flag for if you actually have the
> "change
> MAC address during connect" attribute.
> 
> johannes
>