Re: Dual mode operation

[Dan Williams <dcbw@redhat.com>]

On Tue, 2015-06-30 at 16:57 -0700, Stark Pister wrote:
> I am trying to figure out how to use virtual interfaces to run my wifi
> module in both AP mode and station mode simultaneously. From the
> description on this page
> (https://wireless.wiki.kernel.org/en/users/documentation/iw/vif) it
> would seem this is possible on devices using the mac80211 subsystem,
> but from what I have read online it only works with madwifi drivers
> which is outdated and abandoned.

Most of the common mac80211-based devices allow this.  You can see what
modes your driver supports by doing:

$ iw phy phy0 info
...
  software interface modes (can always be added):
  	 * AP/VLAN
  	 * monitor
  valid interface combinations:
  	 * #{ managed } <= 1, #{ AP, P2P-client, P2P-GO } <= 1,
#{ P2P-device } <= 1,
  	   total <= 3, #channels <= 2
...

This is for an Intel 7265 card, and you can see that this device
supports simultaneous STA and AP modes, but only one interface of each.

> Are there other drivers that tap into this capability of mac80211 or
> is no one else interested in this? Is the generic nl80211 driver
> capable of using this functionality and if so, how do I go about using
> it (note that the "AP" and "Station" sections of the above
> documentation page are blank)? If not, what would I have to change to
> enable the use of this dual mode capability?

Whether your device has this capability highly depends on the hardware,
firmware, and driver.  The 'iw' command I posted above will show what
your combination supports.

Dan