A while ago, I made the mac80211 station code never change
the channel type after association. This solved a number of
issues but is ultimately wrong, we should react if the AP
changes the HT operation IE and switches bandwidth. One of
the issues is that we associate as HT40 capable, but if the
AP ever switches to 40 MHz we won't be able to receive such
frames because we never set our channel to 40 MHz.

This addresses this and VHT operation changes. If there's a
change that is incompatible with our setup, e.g. if the AP
decides to change the channel entirely (and for some reason
we still hear the beacon) we'll just disconnect.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The next patch will need it further up in the file, so
move it unchanged now.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The channel use is confusing, some uses the channel
context and some the bss_conf.chandef. The latter is
fine, so get rid of the channel context part.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Having HT/VHT operation IEs but not capability IEs
leads to a strange situation where we configure the
channel to an HT or VHT bandwidth and then can't
actually use it. Prevent this by checking that the
HT and VHT capability IEs are present as well as
the operation IEs; if not, disable HT and/or VHT.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

In beacons and association response frames an AP may include an
operating mode notification element to advertise changes in the
number of spatial streams it can receive. Handle this using the
existing function that handles the action frame, but only handle
NSS changes, not bandwidth changes which aren't allowed here.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The code to disable HT and VHT if VHT was advertised
without VHT is wrong -- it accidentally uses the wrong
flags. Fix that.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

In case of connection, the station data is initialised from
the beacon/probe response first and then updated from the
association response. If the latter is different we update
the rate control algorithm and driver. Instead of doing it
this way, set the station data properly with data from the
association response before initializing rate control.

Also simplify the code by passing the station pointer.
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>

Like with HT, make things a bit simpler in future patches by
passing the station to ieee80211_vht_cap_ie_to_sta_vht_cap()
instead of the vht_cap pointer. Also disable VHT here if HT
isn't supported.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

In some cases when disconnecting after (or during?) CSA
the queues might not recover, and then the only way to
recover is reloading the module.

Fix this by always unblocking the queue CSA reason when
disconnecting.

Cc: stable@vger.kernel.org
Reported-by: NJan-Michael Brummer <jan.brummer@tabos.org>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

In my commit 1672c0e3
("mac80211: start auth/assoc timeout on frame status")
I broke auth/assoc timeout handling: in case we wait
for the TX status, it now leaves the timeout field set
to 0, which is a valid time and can compare as being
before now ("jiffies"). Thus, if the work struct runs
for some other reason, the auth/assoc is treated as
having timed out.

Fix this by introducing a separate "timeout_started"
variable that tracks whether the timeout has started
and is checked before timing out.

Additionally, for proper TX status handling the change
requires that the skb->dev pointer is set up for all
the frames, so set it up for all frames in mac80211.
Reported-by: NWojciech Dubowik <Wojciech.Dubowik@neratec.com>
Tested-by: NWojciech Dubowik <Wojciech.Dubowik@neratec.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Function ieee80211_sta_reset_conn_monitor has been
resetting probe_send_count too early and nullfunc
check was never called after succesfull ack.
Reported-by: NMagnus Cederlöf <mcider@gmail.com>
Tested-by: NMagnus Cederlöf <mcider@gmail.com>
Signed-off-by: NWojciech Dubowik <Wojciech.Dubowik@neratec.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Add command to trigger radar detection in the driver/FW.
Once radar detection is started it should continuously
monitor for radars as long as the channel active.
If radar is detected usermode notified with 'radar
detected' event.

Scanning and remain on channel functionality must be disabled
while doing radar detection/scanning, and vice versa.

Based on original patch by Victor Goldenshtein <victorg@ti.com>
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Scans currently work by stopping the netdev tx queues but leaving the
mac80211 queues active. This stops the flow of incoming packets while
still allowing mac80211 to transmit nullfunc and probe request frames to
facilitate scanning. However, the driver may try to wake the mac80211
queues while in this state, which will also wake the netdev queues.

To prevent this, add a new queue stop reason,
IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL, to be used when stopping the tx
queues for off-channel operation. This prevents the netdev queues from
waking when a driver wakes the mac80211 queues.

This also stops all frames from being transmitted, even those meant to
be sent off-channel. Add a new tx control flag,
IEEE80211_TX_CTL_OFFCHAN_TX_OK, which allows frames to be transmitted
when the queues are stopped only for the off-channel stop reason. Update
all locations transmitting off-channel frames to use this flag.
Signed-off-by: NSeth Forshee <seth.forshee@canonical.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When we get to association, the AP station already exists and
is marked authenticated, so moving it into IEEE80211_STA_AUTH
again is a NOP, remove it.
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>

The functions were added for some sort of Bluetooth
coexistence, but aren't used, so remove them again.
Reviewed-by: NLuciano Coelho <coelho@ti.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

In order to be able to predict the next DTIM TBTT
in the driver, add the ability to use timing data
from beacons only with the new hardware flag
IEEE80211_HW_TIMING_BEACON_ONLY and the BSS info
value sync_dtim_count which is only valid if the
timing data came from a beacon. The data can only
come from a beacon, and if no beacon was received
before association it is updated later together
with the DTIM count notification.
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>

The messages currently refer to probe request probes,
but on some devices null data packets will be used
instead. Make the messages more generic.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This prepares for using the spinlock instead of krefs
which is needed in the next patch to track the refs
of combined BSSes correctly.

Acked-by: Bing Zhao <bzhao@marvell.com> [mwifiex]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When trying to connect to an AP that advertises HT but not
VHT, the mac80211 code erroneously uses the configuration
from the AP as is instead of checking it against regulatory
and local capabilities. This can lead to using an invalid
or even inexistent channel (like 11/HT40+).

Additionally, the return flags from downgrading must be
ORed together, to collect them from all of the downgrades.
Also clarify the message.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

My commit f2d9d270
("mac80211: support VHT association") introduced a
very stupid bug: the loop to downgrade the channel
width never attempted to actually use it again so
it would downgrade all the way to 20_NOHT. Fix it.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

If the driver determined the connection was lost or that
it couldn't securely maintain the connection when coming
out of WoWLAN, send a deauth frame to the AP to also let
it know.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

With multi-channel, there's a corner case where a driver
doesn't receive a beacon soon enough to be able to sync
its timers with the AP. In this case, the only recovery
(after trying again) is to disconnect from the AP. Allow
calling ieee80211_connection_loss() for such cases. To
make that possible, modify the work function to not rely
on the IEEE80211_HW_CONNECTION_MONITOR flag but use new
state kept in the interface instead.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

If the driver determines the connection is lost,
send a deauth frame to the AP anyway just in case
it still considers the connection alive. The frame
might not go through, but at least we've tried.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When sending authentication/association frames they
might take a bit of time to go out because we may
have to synchronise with the AP, in particular in
the case where it's really a P2P GO. In this case
the 200ms fixed timeout could potentially be too
short if the beacon interval is relatively large.

For drivers that report TX status we can do better.
Instead of starting the timeout directly, start it
only when the frame status arrives. Since then the
frame was out on the air, we can wait shorter (the
typical response time is supposed to be 30ms, wait
100ms.) Also, if the frame failed to be transmitted
try again right away instead of waiting.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Currently, when the driver requires the DTIM period,
mac80211 will wait to hear a beacon before association.
This behavior is suboptimal since some drivers may be
able to deal with knowing the DTIM period after the
association, if they get it at all.

To address this, notify the drivers with bss_info_changed
with the new BSS_CHANGED_DTIM_PERIOD flag when the DTIM
becomes known. This might be when changing to associated,
or later when the entire association was done with only
probe response information.

Rename the hardware flag for the current behaviour to
IEEE80211_HW_NEED_DTIM_BEFORE_ASSOC to more accurately
reflect its behaviour. IEEE80211_HW_NEED_DTIM_PERIOD is
no longer accurate as all drivers get the DTIM period
now, just not before association.
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The field is never used, so remove it.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

There's no need to have two checks for "associated"
in ieee80211_sta_restart(), make the first one locked
to not race (unlikely at this point during resume)
and remove the second check.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

For drivers that don't actually flush their queues when
aggregation stop with the IEEE80211_AMPDU_TX_STOP_FLUSH
or IEEE80211_AMPDU_TX_STOP_FLUSH_CONT reasons is done,
like iwlwifi or iwlegacy, mac80211 can then transmit on
a TID that the driver still considers busy. This happens
in the following way:

 - IEEE80211_AMPDU_TX_STOP_FLUSH requested
 - driver marks TID as emptying
 - mac80211 removes tid_tx data, this can copy packets
   to the TX pending queues and also let new packets
   through to the driver
 - driver gets unexpected TX as it wasn't completely
   converted to the new API

In iwlwifi, this lead to the following warning:

WARNING: at drivers/net/wireless/iwlwifi/dvm/tx.c:442 iwlagn_tx_skb+0xc47/0xce0
Tx while agg.state = 4
Modules linked in: [...]
Pid: 0, comm: kworker/0:0 Tainted: G        W   3.1.0 #1
Call Trace:
 [<c1046e42>] warn_slowpath_common+0x72/0xa0
 [<c1046f13>] warn_slowpath_fmt+0x33/0x40
 [<fddffa17>] iwlagn_tx_skb+0xc47/0xce0 [iwldvm]
 [<fddfcaa3>] iwlagn_mac_tx+0x23/0x40 [iwldvm]
 [<fd8c98b6>] __ieee80211_tx+0xf6/0x3c0 [mac80211]
 [<fd8cbe00>] ieee80211_tx+0xd0/0x100 [mac80211]
 [<fd8cc176>] ieee80211_xmit+0x96/0xe0 [mac80211]
 [<fd8cc578>] ieee80211_subif_start_xmit+0x348/0xc80 [mac80211]
 [<c1445207>] dev_hard_start_xmit+0x337/0x6d0
 [<c145eee9>] sch_direct_xmit+0xa9/0x210
 [<c14462c0>] dev_queue_xmit+0x1b0/0x8e0

Fortunately, solving this problem is easy as the station
is being destroyed, so such transmit packets can only
happen due to races. Instead of trying to close the race
just let the race not reach the drivers by making two
changes:
 1) remove the explicit aggregation session teardown in
    the managed mode code, the same thing will be done
    when the station is removed, in __sta_info_destroy.
 2) When aggregation stop with AGG_STOP_DESTROY_STA is
    requested, leave the tid_tx data around as stopped.
    It will be cleared and freed in cleanup_single_sta
    later, but until then any racy packets will be put
    onto the tid_tx pending queue instead of transmitted
    which is fine since the station is being removed.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Since drivers can support several BSS / P2P Client
interfaces, the rssi callback needs to inform the driver
about the interface teh rssi event relates to.
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Depending on the driver, having ARP filtering for
some addresses may be possible. Remove the logic
that tracks whether ARP filter is enabled or not
and give the driver the total number of addresses
instead of the length of the list so it can make
its own decision.
Reviewed-by: NLuciano Coelho <coelho@ti.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

My commit 4bf88530
("mac80211: convert to channel definition struct")
accidentally broke HT40 connections due to swapped
channel flag checks -- fix that.
Reported-by: NSujith Manoharan <sujith@msujith.org>
Tested-by: NSujith Manoharan <sujith@msujith.org>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The initiator/tx doesn't really identify why an
aggregation session is stopped, give a reason
for stopping that more clearly identifies what's
going on. This will help tell the driver clearly
what is expected of it.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

In interoperability testing some APs showed bad behaviour
if some of the VHT capabilities of the station are better
than their own. Restrict the assoc request parameters
 - beamformee capabable,
 - RX STBC and
 - RX MCS set
to the subset that the AP can support.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The probe response/beacon management frame RX code passes a
bool parameter to differentiate beacons and probe responses.
This is useless since we have the frame and can thus use its
frame control field. Moreover it is buggy since there is one
call to ieee80211_rx_bss_info with a beacon frame that is
indicated as a probe response, which is also fixed by using
the frame control field, so do that.
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The last fixes re-added the RCU synchronize penalty
on roaming to fix the races. Split up sta_info_flush()
now to get rid of that again, and let managed mode
(and only it) delay the actual destruction.
Tested-by: NBen Greear <greearb@candelatech.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When all interfaces have been removed, there can't
be any stations left over, so there's no need to
flush again. Remove this, and all code associated
with it, which also simplifies the function.
Tested-by: NBen Greear <greearb@candelatech.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When AP's SSID is hidden the BSS can appear several times in
cfg80211's BSS list: once with a zero-length SSID that comes
from the beacon, and once for each SSID from probe reponses.

Since the mac80211 stores its data in ieee80211_bss which
is embedded into cfg80211_bss, mac80211's data will be
duplicated too.

This becomes a problem when a driver needs the dtim_period
since this data exists only in the beacon's instance in
cfg80211 bss table which isn't the instance that is used
when associating.

Remove the DTIM period from the BSS table and track it
explicitly to avoid this problem.

Cc: stable@vger.kernel.org
Tested-by: NEfi Tubul <efi.tubul@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>