On 2.4Ghz band, the channels overlap since the delta
between different channels is 5Mhz while the width of the
receiver is 20Mhz (at least).
This means that we can hear beacons or probe responses from
adjacent channels. These frames will have a significant
lower RSSI which will feed all kinds of logic with inaccurate
data. An obvious example is the roaming algorithm that will
think our AP is getting weak and will try to move to another
AP.
In order to avoid this, update the signal only if the frame
has been heard on the same channel as the one advertised by
the AP in its DS / HT IEs.
We refrain from updating the values only if the AP is
already in the BSS list so that we will still have a valid
(but inaccurate) value if the AP was heard on an adjacent
channel only.
To achieve this, stop taking the channel from DS / HT IEs
in mac80211. The DS / HT IEs is taken into account to
discard the frame if it was received on a disabled channel.
This can happen due to the same phenomenon: the frame is
sent on channel 12, but heard on channel 11 while channel
12 can be disabled on certain devices. Since this check
is done in cfg80211, stop even checking this in mac80211.
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
[remove unused rx_freq variable]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Error codes returned by cfg80211_chandef_dfs_required() are ignored
when trying to join an IBSS. Fix this by printing an error and
returning.
Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Currently, when a station leaves an IBSS network, the
corresponding BSS is not dropped from cfg80211 if there are
other active stations in the network. But, the small
window that is present when trying to determine a station's
status based on IEEE80211_IBSS_MERGE_INTERVAL introduces
a race.
Instead of trying to keep the BSS, always remove it when
leaving an IBSS network. There is not much benefit to retain
the BSS entry since it will be added with a subsequent join
operation.
This fixes an issue where a dangling BSS entry causes ath9k
to wait for a beacon indefinitely.
Cc: <stable@vger.kernel.org>
Reported-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
When receiving an IBSS_JOINED event select the BSS object
based on the {bssid, channel} couple rather than the bssid
only.
With the current approach if another cell having the same
BSSID (but using a different channel) exists then cfg80211
picks up the wrong BSS object.
The result is a mismatching channel configuration between
cfg80211 and the driver, that can lead to any sort of
problem.
The issue can be triggered by having an IBSS sitting on
given channel and then asking the driver to create a new
cell using the same BSSID but with a different frequency.
By passing the channel to cfg80211_get_bss() we can solve
this ambiguity and retrieve/create the correct BSS object.
All the users of cfg80211_ibss_joined() have been changed
accordingly.
Moreover WARN when cfg80211_ibss_joined() gets a NULL
channel as argument and remove a bogus call of the same
function in ath6kl (it does not make sense to call
cfg80211_ibss_joined() with a zero BSSID on ibss-leave).
Cc: Kalle Valo <kvalo@qca.qualcomm.com>
Cc: Arend van Spriel <arend@broadcom.com>
Cc: Bing Zhao <bzhao@marvell.com>
Cc: Jussi Kivilinna <jussi.kivilinna@iki.fi>
Cc: libertas-dev@lists.infradead.org
Acked-by: Kalle Valo <kvalo@qca.qualcomm.com>
Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
[minor code cleanup in ath6kl]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Compiling with W=1 found a few variables that are set
but not used (-Wunused-but-set-variable), remove them.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Responding to probe requests for scanning clients will often create
excessive retries, as it happens quite often that the scanning client
already left the channel. Therefore do it like hostapd and send probe
responses for wildcard SSID only once by using the noack flag.
Signed-off-by: Simon Wunderlich <simon@open-mesh.com>
[fix typo & 'wildcard SSID' in commit log]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The ieee80211_vif_use_channel() function calls
ieee80211_vif_release_channel(), so there's no need to call it
explicitly in __ieee80211_sta_join_ibss().
Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The patch adds a missing sdata lock and adds a few
lockdeps for easier maintenance.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
radar_required setting wasn't protected by
local->mtx in some places. This should prevent
from scanning/radar detection/roc colliding.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Instead of having
ieee80211_bss_info_change_notify() scattered all
over the place just call it once when finalizing
CSA.
As a side effect this patch adds missing error
checking for IBSS CSA beacon update.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Reviewed-by: Luciano Coelho <luciano.coelho@intel.com>
[fix err vs. changed variable usage in ieee80211_csa_finalize()]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
A beacon should never have a Channel Switch Announcement information
element with a count of 0, because a count of 1 means switch just
before the next beacon. So, if a count of 0 was valid in a beacon, it
would have been transmitted in the next channel already, which is
useless. A CSA count equal to zero is only meaningful in action
frames or probe_responses.
Fix the ieee80211_csa_is_complete() and ieee80211_update_csa()
functions accordingly.
With a CSA count of 0, we won't transmit any CSA beacons, because the
switch will happen before the next TBTT. To avoid extra work and
potential confusion in the drivers, complete the CSA immediately,
instead of waiting for the driver to call ieee80211_csa_finish().
To keep things simpler, we also switch immediately when the CSA count
is 1, while in theory we should delay the switch until just before the
next TBTT.
Additionally, move the ieee80211_csa_finish() function to cfg.c,
where it makes more sense.
Tested-by: Simon Wunderlich <sw@simonwunderlich.de>
Acked-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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: Kalle Valo <kvalo@qca.qualcomm.com>
Tested-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Johannes 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: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes 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: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes 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: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes 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: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Johannes 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: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Johannes 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: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
[Fixed compilation with mesh]
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes 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: Chun-Yeow Yeoh <yeohchunyeow@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Refactor the channel switch IE parsing to reduce the number
of function parameters.
Signed-off-by: Chun-Yeow Yeoh <yeohchunyeow@cozybit.com>
Signed-off-by: Johannes 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: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: Johannes 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: Johannes 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: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: Johannes 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: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: Johannes 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: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: Johannes 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: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Johannes 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: Johannes 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: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: Johannes 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: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Johannes 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: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Johannes 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: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Johannes 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: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Johannes 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: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Johannes 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: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: Johannes 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: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: Johannes 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: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
[make rate unsigned in ieee80211_add_tx_radiotap_header(), squash fix]
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
This reverts commit 6d810f1032
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: Antonio Quartulli <antonio@open-mesh.com>
[remove unused variable]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This should make some parts cleaner and is also required for handling
5/10 MHz properly.
Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: Johannes 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: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: Johannes 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: Johannes 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: Johannes 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: Marek Puzyniak <marek.puzyniak@tieto.com>
Signed-off-by: Johannes 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: Johannes 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: Johannes Berg <johannes.berg@intel.com>
Emmanuel Grumbach