2015-06-30 23:57:37

by Stark Pister

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Subject: Dual mode operation

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which is outdated and abandoned.

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?

--
Stark Pister
Software Developer
Cirrent.co
(925) 818-1813


2015-07-01 14:53:46

by Dan Williams

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Subject: Re: Dual mode operation

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 which is outdated and abandoned.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