The scan code creates an iflist_mtx -> mtx locking dependency,
and a few other places, notably radar detection, were creating
the opposite dependency, causing lockdep to complain. As scan
and radar detection are mutually exclusive, the deadlock can't
really happen in practice, but it's still bad form.

A similar issue exists in the monitor mode code, but this is
only used by channel-context drivers right now and those have
to have hardware scan, so that also can't happen.

Still, fix these issues by making some of the channel context
code require the mtx to be held rather than acquiring it, thus
allowing the monitor/radar callers to keep the iflist_mtx->mtx
lock ordering.

While at it, also fix access to the local->scanning variable
in the radar code, and document that radar_detect_enabled is
now properly protected by the mtx.

All this would now introduce an ABBA deadlock between the DFS
work cancelling and local->mtx, so change the locking there a
bit to not need to use cancel_delayed_work_sync() but be able
to just use cancel_delayed_work(). The work is also safely
stopped/removed when the interface is stopped, so no extra
changes are needed.
Reported-by: NKalle Valo <kvalo@qca.qualcomm.com>
Tested-by: NSimon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The return value of ieee80211_ibss_csa_beacon is not aligned with the
return value of ieee80211_assign_beacon().  For consistency and to be
able to use both functions with similar code, change
ieee80211_ibss_csa_beacon() not to send the bss changed notification
itself, but return what has changed so the caller can send the
notification instead.

Tested by: Simon Wunderlich <sw@simonwunderlich.de>
Acked by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: NLuciano Coelho <luciano.coelho@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Refactor ieee80211_ibss_process_chanswitch() to use
ieee80211_channel_switch() and avoid code duplication.

Tested by: Simon Wunderlich <sw@simonwunderlich.de>
Acked by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: NLuciano Coelho <luciano.coelho@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

We call ieee80211_ibss_disconnect(), which requires sdata to be
locked, so lock the sdata during ieee80211_csa_connection_drop_work().

Cc: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: NLuciano Coelho <luciano.coelho@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This fixes a regression introduced by my patch "mac80211: don't cancel
csa finalize work within stop_ap", which added sdata locks to
ieee80211_csa_finalize_work() without removing the locking for
ieee80211_ibss_finish_csa(), which is called by the former, resulting
in a deadlock due to nested locking.
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When external CSA IEs are received (beacons or action messages), a
channel switch is triggered as well. This should only be allowed on
devices which actually support channel switches, otherwise disconnect.
(For the corresponding userspace invocation, the wiphy flag is checked
in nl80211).
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

There is no reason why we should have only one channel switch
announcement at a time for a single phy.  When support for channel
switch with multiple contexts and multiple vifs per context is
implemented, we will need the chandef data for each vif.  Move the
csa_chandef structure to sdata to prepare for this.
Reviewed-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NLuciano Coelho <luciano.coelho@intel.com>
[Fixed compilation with mesh]
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Allow the triggering of CSA frame using mesh interface. The
rules are more or less same with IBSS, such as not allowed to
change between the band and channel width has to be same from
the previous mode. Also, move the ieee80211_send_action_csa
to a common space so that it can be re-used by mesh interface.
Signed-off-by: NChun-Yeow Yeoh <yeohchunyeow@cozybit.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Refactor the channel switch IE parsing to reduce the number
of function parameters.
Signed-off-by: NChun-Yeow Yeoh <yeohchunyeow@cozybit.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Allow changing to DFS channels if the channel is available for
beaconing and userspace controls DFS operation.

Channel switch announcement from other stations on DFS channels will
be interpreted as radar event. These channels will then be marked as
unvailable.
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NMathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This can be useful for drivers if they have any failure cases
when joining an IBSS. Also move setting the queue parameters
to before this new call, in case the new driver op needs them
already.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

IBSS members may not immediately be able to send out their beacon when
performing CSA, therefore also send a CSA action frame.
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NMathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This function adds the channel switch announcement implementation for the
IBSS code. It is triggered by userspace (mac80211/cfg) or by external
channel switch announcement, which have to be adopted. Both CSAs in
beacons and action frames are supported. As for AP mode, the channel
switch is applied after some time. However in IBSS mode, the channel
switch IEs are generated in the kernel.
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NMathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

IBSS CSA will require to disconnect if a channel switch fails, but
mac80211 should search and re-connect after this disconnect. To allow
such usage, split off the ibss disconnect process in a separate function
which only performs the disconnect without overwriting nl80211-supplied
parameters.
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NMathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

my earlier patch "mac80211: change IBSS channel state to chandef"
created a regression by ignoring the channel parameter in
__ieee80211_sta_join_ibss, which breaks IBSS channel selection. This
patch fixes this situation by using the right channel and adopting the
selected bandwidth mode.

Cc: stable@vger.kernel.org
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

IBSS needs to release the channel context when leaving
but I evidently missed that. Fix it.

Cc: stable@vger.kernel.org
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Channel Switch will later require to generate beacons without setting
them immediately. Therefore split the presp generation in an own
function. Splitting the original very long function might be a good idea
anyway.
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NMathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

In some cases mac80211 will scan before creating an IBSS
even if bssid and frequency have been forced by the user.
This is not needed and leads only to a delay in the IBSS
establishment phase.

Immediately create the cell if both bssid and frequency
(and fixed_freq is set) have been specified.
Signed-off-by: NAntonio Quartulli <antonio@open-mesh.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

A station which is not authorized has to be purged earlier
to give it a chance to re-try to establish an IBSS/RSN
session soon. Set the timeout to 10 seconds.

Some refactoring has also been done to allow the IBSS
submodule to have its own expiring function.
Reported-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NAntonio Quartulli <antonio@open-mesh.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

There is an off-by-one error in the beacon generation for the ibss mode,
falsely a rate the extended supported rates which was already added to
supported rates, messing up the beacon. This was introduced by commit
"mac80211: select and adjust bitrates according to channel mode".
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

There appear to be two regressions in ibss.c when calling
ieee80211_sta_def_wmm_params():
 * the second argument should be a rate length, not a rate array. This
   was introduced by my commit "mac80211: select and adjust bitrates
   according to channel mode"
 * the third argument is not initialized (anymore), making further
   checks within this function useless.

Since ieee80211_sta_def_wmm_params() is only used by ibss anyway,
remove the function entirely and handle the operating mode decision
immediately.
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This was originally designed to fail when a 40+/40- mode can not be
used, but basic modes (such as 5/10/20 MHz) must be handled
with an error.
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>

Use a chandef instead of just the channel for scanning, and enable
5/10 Mhz scanning for IBSS mode. Also reporting is changed to the new
inform_bss functions.
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NMathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>

Mandatory rates for 5 and 10 MHz are different from the rates used for
20 MHz in 2.4 GHz mode, as they use OFDM only.
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NMathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>

The various components accessing the bitrates table must use consider
the used channel bandwidth to select only available rates or calculate
the bitrate correctly.

There are some rates in reduced bandwidth modes which can't be
represented as multiples of 500kbps, like 2.25 MBit/s in 5 MHz mode. The
standard suggests to round up to the next multiple of 500kbps, just do
that in mac80211 as well.
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NMathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
[make rate unsigned in ieee80211_add_tx_radiotap_header(), squash fix]
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>

Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NMathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>

This reverts commit 6d810f10

In this way an IBSS station will not use the AUTH messages
to trigger a state reinitialisation anymore.

The behaviour was racy and was not working properly.
It has been introduced to help wpa_supplicant to support
IBSS/RSN, however all the logic is now getting moved into
wpa_s itself which will also be in charge of handling the
AUTH messages thanks to the mgmt frame registration.

If userspace does not register for receiving AUTH frames
then mac80211 will still reply by itself.

At the same time, the auth frame registration counter can be
removed since it is not needed anymore.
Signed-off-by: NAntonio Quartulli <antonio@open-mesh.com>
[remove unused variable]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This should make some parts cleaner and is also required for handling
5/10 MHz properly.
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NMathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This is a collection of minor fixes:
 * don't allow HT IEs in IBSS for 5/10 MHz
 * don't allow HT IEs in Mesh for 5/10 MHz
 * don't downgrade from/to 5 and 10 MHz channels
 * don't try HT rates for 5 and 10 MHz channels when selecting rates
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NMathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Using separate locks in cfg80211 and mac80211 has always
caused issues, for example having to unlock in places in
mac80211 to call cfg80211, which even needed a framework
to make cfg80211 calls after some functions returned etc.

Additionally, I suspect some issues people have reported
with the cfg80211 state getting confused could be due to
such issues, when cfg80211 is asking mac80211 to change
state but mac80211 is in the process of telling cfg80211
that the state changed (in another way.)
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Move mandatory rates calculation to cfg80211, shared with non mac80211 drivers.
Signed-off-by: NAshok Nagarajan <ashok@cozybit.com>
[extend documentation]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

VHT introduces multiple IEs that need to be parsed for a
wide bandwidth channel switch. Two are (currently) needed
in mac80211:
 * wide bandwidth channel switch element
 * channel switch wrapper element

The former is contained in the latter for beacons and probe
responses, but not for the spectrum management action frames
so the IE parser needs a new argument to differentiate them.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Some drivers need SSID in AP and IBSS mode. AP SSID is provided
through BSS_CHANGED_SSID notification. There was no easy way to
do the same for IBSS. In IBSS mode SSID is known but was not
stored in BSS configuration. Extend the AP-mode functionality
to also work in IBSS mode.
Signed-off-by: NMarek Puzyniak <marek.puzyniak@tieto.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

It's always just one byte, so check for that and
remove the length field from the parser struct.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Instead of having an SKB all the time, use a beacon_data struct
with just the information required. This also allows removing a
synchronize_rcu() and using kfree_rcu() instead.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

If we don't disable beaconing, the driver might attempt
to continue, but would fail to request a beacon. That's
strange, so disable beaconing first.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Remove not used any longer suspend/resume code.
Signed-off-by: NStanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

For VHT, many more bandwidth changes are possible. As a first
step, stop toggling the IEEE80211_HT_CAP_SUP_WIDTH_20_40 flag
in the HT capabilities and instead introduce a bandwidth field
indicating the currently usable bandwidth to transmit to the
station. Of course, make all drivers use it.

To achieve this, make ieee80211_ht_cap_ie_to_sta_ht_cap() get
the station as an argument, rather than the new capabilities,
so it can set up the new bandwidth field.

If the station is a VHT station and VHT bandwidth is in use,
also set the bandwidth accordingly.

Doing this allows us to get rid of the supports_40mhz flag as
the HT capabilities now reflect the true capability instead of
the current setting.

While at it, also fix ieee80211_ht_cap_ie_to_sta_ht_cap() to not
ignore HT cap overrides when MCS TX isn't supported (not that it
really happens...)
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Now that we have channel contexts, idle is (pretty
much) equivalent to not having a channel context.
Change the code to use this relation so that there
no longer is a need for a lot of idle recalculate
calls everywhere.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

While technically the TSF isn't an IE, it can be
necessary to distinguish between the TSF from a
beacon and a probe response, in particular in
order to know the next DTIM TBTT, as not all APs
are spec compliant wrt. TSF==0 being a DTIM TBTT
and thus the DTIM count needs to be taken into
account as well.

To allow this, move the TSF into the IE struct
so it can be known whence it came.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>