mix AP and wireless client

[Dan Williams]

On Wed, 2015-01-21 at 11:05 +0100, Harm Verhagen wrote:
> Ignoring the lack  of "valid interface combinations:"    just trying a 2nd
> interface

Lack of "valid interface combinations" means that the driver is not
advertising the ability, and therefore we cannot assume that it actually
works.  The kernel support for this has been around 2011 (kernel version
3.0) so any driver that doesn't support it probably doesn't work well...

I see you said GWF-3M05 which appears to be a ralink device.  Which
kernel version and which ralink driver are you using?  Are you using
rt2800usb or are you using a vendor driver?

Dan

>     iw dev wlan0 interface add wlan0-STA type managed
> 
>     ip link set dev wlan0-STA address 7C:CD:EF:00:01:02    # prevent  "Name
> not unique on network" error
> 
> ifup wlan0-STA    works fine as STA, connects and gets ip.
> 
> But then upping wlan (just a static ip, no hostapd yet) fails
> 
>     $ ifup wlan0
> 
>     ifconfig: SIOCSIFFLAGS: No buffer space available
> 
>     ifconfig: SIOCSIFFLAGS: No buffer space available

This error usually appears to mean out-of-memory when constructing
netlink packets, which is the protocol that 'iw' and the kernel use to
communicate.  So clearly there are either driver or kernel stack bugs or
issues on this platform.

Dan

> 
> What could cause such a "No buffer space available" ?
> 
> Regards,
> Harm
> 
> 
> On Wed, Jan 21, 2015 at 9:45 AM, Harm Verhagen <harm.verhagen at gmail.com>
> wrote:
> 
> >
> >
> > On Thu, Jan 15, 2015 at 6:51 PM, Dan Williams <dcbw at redhat.com> wrote:
> >
> >>
> >> > This gave me the idea, that if hostapd can create 'new' wlan devices. I
> >> > (hopefully) can configure the 2nd  wlan0_0 device as a wifi client.
> >>
> >> It depends on your hardware and driver whether this is possible.  Look
> >> at the output of "iw phy phy0 info", where you should see stuff like:
> >>
> >>         valid interface combinations:
> >>                  * #{ managed } <= 1, #{ AP } <= 1,
> >>                    total <= 2, #channels <= 1, STA/AP BI must match
> >>                  * #{ managed } <= 2,
> >>                    total <= 2, #channels <= 1
> >>
> >> These lines indicate what your hardware and driver can do at the same
> >> time.  In this case (Intel 6250, iwldvm driver) I can do 1 AP + 1 STA,
> >> or 2 STA at the same time, but all must be on the same radio channel.
> >>
> >>
> > I got myself iw on the platform.
> >
> > "iw phy phy0 info"  however does not show any  "valid interface
> > combinations:" section.  Should it ?
> >
> > Does this mean my hardware does not support it ?  Or does it mean
> > something else. (wrong iw/driver/kernel version?)
> >
> > $ iw --version
> > iw version 3.11
> >
> > kernel: 3.1.10
> >
> > find attached the output  of   "iw phy phy info > iw_phy_phy0_info.output"
> >
> > Regards,
> > Harm Verhagen
> >
> >
> >
> >
> >