There's an issue with the way the RX A-MPDU reorder timer is
deleted that can cause a kernel crash like this:

 * tid_rx is removed - call_rcu(ieee80211_free_tid_rx)
 * station is destroyed
 * reorder timer fires before ieee80211_free_tid_rx() runs,
   accessing the station, thus potentially crashing due to
   the use-after-free

The station deletion is protected by synchronize_net(), but
that isn't enough -- ieee80211_free_tid_rx() need not have
run when that returns (it deletes the timer.) We could use
rcu_barrier() instead of synchronize_net(), but that's much
more expensive.

Instead, to fix this, add a field tracking that the session
is being deleted. In this case, the only re-arming of the
timer happens with the reorder spinlock held, so make that
code not rearm it if the session is being deleted and also
delete the timer after setting that field. This ensures the
timer cannot fire after ___ieee80211_stop_rx_ba_session()
returns, which fixes the problem.

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

If the AP is confused and starts doing a CSA to the same channel,
just ignore that request instead of trying to act it out since it
was likely sent in error anyway.

In the case of the bug I was investigating the GO was misbehaving
and sending out a beacon with CSA IEs still included after having
actually done the channel switch.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When a beacon from the AP contains only the ECSA IE, and not a CSA IE
as well, this ECSA IE is not considered for calculating the CRC and
the beacon might be dropped as not being interesting. This is clearly
wrong, it should be handled and the channel switch should be executed.

Fix this by including the ECSA IE ID in the bitmap of interesting IEs.
Reported-by: NGil Tribush <gil.tribush@intel.com>
Reviewed-by: NLuciano Coelho <luciano.coelho@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Since moving the interface combination checks to mac80211, it's
broken because it now only considers interfaces with an assigned
channel context, so for example any interface that isn't active
can still be up, which is clearly an issue; also, in particular
P2P-Device wdevs are an issue since they never have a chanctx.

Fix this by counting running interfaces instead the ones with a
channel context assigned.

Cc: stable@vger.kernel.org [3.16+]
Fixes: 73de86a3 ("cfg80211/mac80211: move interface counting for combination check to mac80211")
Signed-off-by: NAndrei Otcheretianski <andrei.otcheretianski@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
[rewrite commit message, dig out the commit it fixes]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Some APs experience problems when working with
U-APSD. Decreasing the probability of that
happening by using legacy mode for all ACs but VO
isn't enough.

Cisco 4410N originally forced us to enable VO by
default only because it treated non-VO ACs as
legacy.

However some APs (notably Netgear R7000) silently
reclassify packets to different ACs. Since u-APSD
ACs require trigger frames for frame retrieval
clients would never see some frames (e.g. ARP
responses) or would fetch them accidentally after
a long time.

It makes little sense to enable u-APSD queues by
default because it needs userspace applications to
be aware of it to actually take advantage of the
possible additional powersavings. Implicitly
depending on driver autotrigger frame support
doesn't make much sense.

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

The mesh forwarding path was not checking that data
frames were protected when running an encrypted network;
add the necessary check.

Cc: stable@vger.kernel.org
Reported-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NBob Copeland <me@bobcopeland.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The current minstrel_ht rate control behavior is somewhat optimistic in
trying to find optimum TX rate. While this is usually fine for normal
Data frames, there are cases where a more conservative set of retry
parameters would be beneficial to make the connection more robust.

EAPOL frames are critical to the authentication and especially the
EAPOL-Key message 4/4 (the last message in the 4-way handshake) is
important to get through to the AP. If that message is lost, the only
recovery mechanism in many cases is to reassociate with the AP and start
from scratch. This can often be avoided by trying to send the frame with
more conservative rate and/or with more link layer retries.

In most cases, minstrel_ht is currently using the initial EAPOL-Key
frames for probing higher rates and this results in only five link layer
transmission attempts (one at high(ish) MCS and four at MCS0). While
this works with most APs, it looks like there are some deployed APs that
may have issues with the EAPOL frames using HT MCS immediately after
association. Similarly, there may be issues in cases where the signal
strength or radio environment is not good enough to be able to get
frames through even at couple of MCS 0 tries.

The best approach for this would likely to be to reduce the TX rate for
the last rate (3rd rate parameter in the set) to a low basic rate (say,
6 Mbps on 5 GHz and 2 or 5.5 Mbps on 2.4 GHz), but doing that cleanly
requires some more effort. For now, we can start with a simple one-liner
that forces the minimum rate to be used for EAPOL frames similarly how
the TX rate is selected for the IEEE 802.11 Management frames. This does
result in a small extra latency added to the cases where the AP would be
able to receive the higher rate, but taken into account how small number
of EAPOL frames are used, this is likely to be insignificant. A future
optimization in the minstrel_ht design can also allow this patch to be
reverted to get back to the more optimized initial TX rate.

It should also be noted that many drivers that do not use minstrel as
the rate control algorithm are already doing similar workarounds by
forcing the lowest TX rate to be used for EAPOL frames.

Cc: stable@vger.kernel.org
Reported-by: NLinus Torvalds <torvalds@linux-foundation.org>
Tested-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NJouni Malinen <jouni@qca.qualcomm.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Commit 06d961a8 ("mac80211/minstrel: use the new rate control API")
inverted the condition 'if (msr->sample_limit != 0)' to
'if (!msr->sample_limit != 0)'. But it is confusing both to people and
compilers (gcc5):
net/mac80211/rc80211_minstrel.c: In function 'minstrel_get_rate':
net/mac80211/rc80211_minstrel.c:376:26: warning: logical not is only applied to the left hand side of comparison
   if (!msr->sample_limit != 0)
                          ^

Let there be only 'if (!msr->sample_limit)'.

Fixes: 06d961a8 ("mac80211/minstrel: use the new rate control API")
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

If ieee80211_vif_use_channel() fails, we have to clear
sdata->radar_required (which we might have just set).

Failing to do it results in stale radar_required field
which prevents starting new scan requests.
Reported-by: NJouni Malinen <j@w1.fi>
Signed-off-by: NEliad Peller <eliad@wizery.com>
[use false instead of 0]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This allows mac80211 to configure BIP-GMAC-128 and BIP-GMAC-256 to the
driver and also use software-implementation within mac80211 when the
driver does not support this with hardware accelaration.
Signed-off-by: NJouni Malinen <jouni@qca.qualcomm.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This allows mac80211 to configure BIP-CMAC-256 to the driver and also
use software-implementation within mac80211 when the driver does not
support this with hardware accelaration.
Signed-off-by: NJouni Malinen <jouni@qca.qualcomm.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This allows mac80211 to configure CCMP-256 to the driver and also use
software-implementation within mac80211 when the driver does not support
this with hardware accelaration.
Signed-off-by: NJouni Malinen <jouni@qca.qualcomm.com>
[squash ccmp256 -> mic_len argument change]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This allows mac80211 to configure GCMP and GCMP-256 to the driver and
also use software-implementation within mac80211 when the driver does
not support this with hardware accelaration.
Signed-off-by: NJouni Malinen <jouni@qca.qualcomm.com>
[remove a spurious newline]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

If suspend starts while ieee80211_scan_completed() is running, between
the point where SCAN_COMPLETED is set and the work is queued,
ieee80211_scan_cancel() will not catch the work and we may finish
suspending before the work is actually executed, leaving the scan
running while suspended.

To fix this race, queue the scan work during resume if the
SCAN_COMPLETED flag is set and flush it immediately.
Signed-off-by: NLuciano Coelho <luciano.coelho@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

For drivers without beacon filtering, support beacon statistics
entirely, i.e. report the number of beacons and average signal.

For drivers with beacon filtering, give them the number of beacons
received by mac80211 -- in case the device reports only the number
of filtered beacons then driver doesn't have to count all beacons
again as mac80211 already does.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

In the case of non-QoS association, the counter was actually
wrong. The right index isn't security_idx but seqno_idx, as
security_idx will be 0 for data frames, while 16 is needed.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

These conditions are rather difficult to follow, for example
because "!sta" only exists to not crash in the case that we
don't have a station pointer (WLAN_TDLS_SETUP_REQUEST) in
which the additional condition (peer supports HT) doesn't
actually matter anyway.

Cleaning this up only duplicates two lines of code but makes
the rest far easier to read, so do that.

As a side effect, smatch stops complaining about the lack of
a sta pointer test after the !sta (since the !sta goes away)
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

There's no need to use another local 'sta' variable as the
original (outer scope) one isn't needed any more and has
become invalid anyway when exiting the RCU read section.

Remove the inner scope one and along with it the useless NULL
initialization.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This reverts commit 2ae70efc.

The new peer events that are generated by the change are causing problems
with wpa_supplicant in userspace: wpa_s tries to restart SAE authentication
with the peer when receiving the event, even though authentication may be in
progress already, and it gets very confused.

Revert back to the original operating mode, which is to only get events when
there is no corresponding station entry.

Cc: Nishikawa, Kenzoh <Kenzoh.Nishikawa@jp.sony.com>
Cc: Masashi Honma <masashi.honma@gmail.com>
Signed-off-by: NBob Copeland <me@bobcopeland.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

It is possible that a deferred scan is queued after the queues are
flushed in __ieee80211_suspend().  The deferred scan work may be
scheduled by ROC or ieee80211_stop_poll().

To make sure don't start a new scan while suspending, check whether
we're quiescing or suspended and complete the scan immediately if
that's the case.
Signed-off-by: NLuciano Coelho <luciano.coelho@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When we go to suspend, there is complex set of states that
avoids races. The quiescing variable is set whlie
__ieee80211_suspend is running. Then suspended is set.
The code makes sure there is no window without any of these
flags.

The problem is that workers can still be enqueued while we
are quiescing. This leads to situations where the driver is
already suspending and other flows like disassociation are
handled by a worker.

To fix this, we need to check quiescing and suspended flags
in the worker itself and not only before enqueueing it.
I also add here extensive documentation to ease the
understanding of these complex issues.
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When mac80211 disconnects, it drops all the packets on the
queues. This happens after the net stack has been notified
that we have no link anymore (netif_carrier_off).
netif_carrier_off ensures that no new packets are sent to
xmit() callback, but we might have older packets in the
middle of the Tx path. These packets will land in the
driver's queues after the latter have been flushed.
Synchronize_net() between netif_carrier_off and drv_flush()
will fix this.

Note that we can't call synchronize_net inside
ieee80211_flush_queues since there are flows that call
ieee80211_flush_queues and don't need synchronize_net()
which is an expensive operation.
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
[reword comment to be more accurate]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Fix a regression introduced by commit a5e70697 ("mac80211: add radiotap flag
and handling for 5/10 MHz") where the IEEE80211_CHAN_CCK channel type flag was
incorrectly replaced by the IEEE80211_CHAN_OFDM flag. This commit fixes that by
using the CCK flag again.

Cc: stable@vger.kernel.org
Fixes: a5e70697 ("mac80211: add radiotap flag and handling for 5/10 MHz")
Signed-off-by: NMathy Vanhoef <vanhoefm@gmail.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

In normal cases (i.e. when we are fully associated), cfg80211 takes
care of removing all the stations before calling suspend in mac80211.

But in the corner case when we suspend during authentication or
association, mac80211 needs to roll back the station states.  But we
shouldn't roll back the station states in the suspend function,
because this is taken care of in other parts of the code, except for
WDS interfaces.  For AP types of interfaces, cfg80211 takes care of
disconnecting all stations before calling the driver's suspend code.
For station interfaces, this is done in the quiesce code.

For WDS interfaces we still need to do it here, so move the code into
a new switch case for WDS.

Cc: stable@kernel.org [3.15+]
Signed-off-by: NLuciano Coelho <luciano.coelho@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Control per packet Transmit Power Control (TPC) in lower drivers
according to TX power settings configured by the user. In particular TPC is
enabled if value passed in enum nl80211_tx_power_setting is
NL80211_TX_POWER_LIMITED (allow using less than specified from userspace),
whereas TPC is disabled if nl80211_tx_power_setting is set to
NL80211_TX_POWER_FIXED (use value configured from userspace)
Signed-off-by: NLorenzo Bianconi <lorenzo.bianconi83@gmail.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Some drivers unfortunately cannot support software crypto, but
mac80211 currently assumes that they do.

This has the issue that if the hardware enabling fails for some
reason, the software fallback is used, which won't work. This
clearly isn't desirable, the error should be reported and the
key setting refused.

Support this in mac80211 by allowing drivers to set a new HW
flag IEEE80211_HW_SW_CRYPTO_CONTROL, in which case mac80211 will
only allow software fallback if the set_key() method returns 1.
The driver will also need to advertise supported cipher suites
so that mac80211 doesn't advertise any (future) software ciphers
that the driver can't actually do.

While at it, to make it easier to support this, refactor the
ieee80211_init_cipher_suites() code.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Station info state is started in allocation, so should be
destroyed on free (it's just a timer); rate control must
be freed if anything afterwards fails to initialize.

LED exit should be later, no need for locking there, but
it needs to be done also when rate init failed.

Also clean up the code by moving a label so the locking
doesn't have to be done separately.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

While suspending, we destroy the authentication /
association that might be taking place. While doing so, we
forgot to delete the timer which can be firing after
local->suspended is already set, producing the warning below.

Fix that by deleting the timer.

[66722.825487] WARNING: CPU: 2 PID: 5612 at net/mac80211/util.c:755 ieee80211_can_queue_work.isra.18+0x32/0x40 [mac80211]()
[66722.825487] queueing ieee80211 work while going to suspend
[66722.825529] CPU: 2 PID: 5612 Comm: kworker/u16:69 Tainted: G        W  O  3.16.1+ #24
[66722.825537] Workqueue: events_unbound async_run_entry_fn
[66722.825545] Call Trace:
[66722.825552]  <IRQ>  [<ffffffff817edbb2>] dump_stack+0x4d/0x66
[66722.825556]  [<ffffffff81075cad>] warn_slowpath_common+0x7d/0xa0
[66722.825572]  [<ffffffffa06b5b90>] ? ieee80211_sta_bcn_mon_timer+0x50/0x50 [mac80211]
[66722.825573]  [<ffffffff81075d1c>] warn_slowpath_fmt+0x4c/0x50
[66722.825586]  [<ffffffffa06977a2>] ieee80211_can_queue_work.isra.18+0x32/0x40 [mac80211]
[66722.825598]  [<ffffffffa06977d5>] ieee80211_queue_work+0x25/0x50 [mac80211]
[66722.825611]  [<ffffffffa06b5bac>] ieee80211_sta_timer+0x1c/0x20 [mac80211]
[66722.825614]  [<ffffffff8108655a>] call_timer_fn+0x8a/0x300
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

For some reason, we made the bandwidth separate flags, which
is rather confusing - a single rate cannot have different
bandwidths at the same time.

Change this to no longer be flags but use a separate field
for the bandwidth ('bw') instead.

While at it, add support for 5 and 10 MHz rates - these are
reported as regular legacy rates with their real bitrate,
but tagged as 5/10 now to make it easier to distinguish them.

In the nl80211 API, the flags are preserved, but the code
now can also clearly only set a single one of the flags.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

These rates are treated the same as 160 MHz in the spec,
so it makes no sense to distinguish them. As no driver
uses them yet, this is also not a problem, just remove
them.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Radar detection can last indefinite time. There is no
point in deferring a scan request in this case - simply
return -EBUSY.
Signed-off-by: NEliad Peller <eliad@wizery.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

ctx->conf.radar_enabled should reflect whether radar
detection is enabled for the channel context.

When calculating it, make it consider only the vifs
that have this context assigned (instead of all the
vifs).
Signed-off-by: NEliad Peller <eliad@wizery.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

local->radar_detect_enabled should tell whether
radar_detect is enabled on any interface belonging
to local.

However, it's not getting updated correctly
in many cases (actually, when testing with hwsim
it's never been set, even when the dfs master
is beaconing).

Instead of handling all the corner cases
(e.g. channel switch), simply check whether
radar detection is enabled only when needed,
instead of caching the result.
Signed-off-by: NEliad Peller <eliad@wizery.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The function adding the supported channels IE during a TDLS connection had
several issues:
1. If the entire subband is usable, the function exitted the loop without
   adding it
2. The function only checked chandef_usable, ignoring flags like RADAR
   which would prevent TDLS off-channel communcation.
3. HT20 was explicitly required in the chandef, while not a requirement
   for TDLS off-channel.
Signed-off-by: NArik Nemtsov <arikx.nemtsov@intel.com>
Reviewed-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When roaming / suspending, it makes no sense to wait until
the transmit queues of the device are empty. In extreme
condition they can be starved (VO saturating the air), but
even in regular cases, it is pointless to delay the roaming
because the low level driver is trying to send packets to
an AP which is far away. We'd rather drop these packets and
let TCP retransmit if needed. This will allow to speed up
the roaming.

For suspend, the explanation is even more trivial.
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When a station disconnects with frames still pending, we clear
the TIM bit, but too late - it's only cleared when the station
is already removed from the driver, and thus the driver can get
confused (and hwsim will loudly complain.)

Fix this by clearing the TIM bit earlier, when the station has
been unlinked but not removed from the driver yet. To do this,
refactor the TIM recalculation to in that case ignore traffic
and simply assume no pending traffic - this is correct for the
disconnected station even though the frames haven't been freed
yet at that point.

This patch isn't needed for current drivers though as they don't
check the station argument to the set_tim() operation and thus
don't really run into the possible confusion.
Reported-by: NJouni Malinen <j@w1.fi>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Implement the new counters cfg80211 can now advertise to userspace.
The TX code is in the sequence number handler, which is a bit odd,
but that place already knows the TID and frame type, so it was
easiest and least impact there.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This is really just duplicating the list of information that's
already available in the nl80211 attribute, so remove the list.
Two small changes are needed:
 * remove STATION_INFO_ASSOC_REQ_IES complete, but the length
   (assoc_req_ies_len) can be used instead
 * add NL80211_STA_INFO_RX_DROP_MISC which exists internally
   but not in nl80211 yet

This gets rid of the duplicate maintenance of the two lists.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

In many cases, drivers can filter things like beacons that will
skew statistics reported by mac80211. To get correct statistics
in these cases, call drivers to obtain statistics and let them
override all values, filling values from mac80211 if the driver
didn't provide them. Not all of them make sense for the driver
to fill, so some are still always done by mac80211.

Note that this doesn't currently allow a driver to say "I know
this value is wrong, don't report it at all", or to sum it up
with a mac80211 value (as could be useful for "dropped misc"),
that can be added if it turns out to be needed.

This also gets rid of the get_rssi() method as is can now be
implemented using sta_statistics().
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>