We currently have a hand-rolled table with 256 entries and are
using the last byte of the MAC address as the hash. This hash
is obviously very fast, but collisions are easily created and
we waste a lot of space in the common case of just connecting
as a client to an AP where we just have a single station. The
other common case of an AP is also suboptimal due to the size
of the hash table and the ease of causing collisions.

Convert all of this to use rhashtable with jhash, which gives
us the advantage of a far better hash function (with random
perturbation to avoid hash collision attacks) and of course
that the hash table grows and shrinks dynamically with chain
length, improving both cases above.

Use a specialised hash function (using jhash, but with fixed
length) to achieve better compiler optimisation as suggested
by Sergey Ryazanov.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Instead of looking up the destination station twice in the TX path
(first to build the header, and then for control processing), save
it when building the header and use it later in the TX path.

To avoid having to look up the station in the many callers, allow
those to pass %NULL which keeps the existing lookup.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Revert commit ad38bfc9 ("mac80211: Tx frame latency statistics")
(along with some follow-up fixes).

This code turned out not to be as useful in the current form as we
thought, and we've internally hacked it up more, but that's not
very suitable for upstream (for now), and we might just do that
with tracing instead.

Therefore, for now at least, remove this code. We might also need
to use the skb->tstamp field for the TCP performance issue, which
is more important than the debugging.
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>

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>

Use the new cfg80211_del_sta_sinfo() function to send the
statistics about the deleted station with the delete event.
This lets userspace see how much traffic etc. the deleted
station used.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Move IEEE80211_TX_CTL_PS_RESPONSE to info->control.flags since
this is used only in the TX path (by ath9k). This frees up
a bit which can be used for other purposes.
Signed-off-by: NSujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

In TDLS (e.g., TDLS off-channel) there is a requirement for
some drivers to supply an unused TID between the AP and the
device to the FW, to allow sending PTI requests and to allow
the FW to aggregate on a specific TID for better throughput.

To ensure that the allocated TID is indeed unused, this patch
introduces an API for blocking the driver from TXing on that
TID.
Signed-off-by: NLiad Kaufman <liad.kaufman@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Implement the cfg80211 TDLS channel switch ops and introduce new mac80211
ones for low-level drivers.
Verify low-level driver support for the new ops when using the relevant
wiphy feature bit. Also verify the peer supports channel switching before
passing the command down.

Add a new STA flag to track the off-channel state with the TDLS peer and
make sure to cancel the channel-switch if the peer STA is unexpectedly
removed.
Signed-off-by: NArik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: NArik Nemtsov <arik@wizery.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Instead of passing the band as a parameter to ieee80211_xmit()
and ieee80211_tx(), move it outside of the two functions while
making sure info->band is set up before calling them.

This removes the parameter and simplifies the follow commit.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NArik Nemtsov <arik@wizery.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Deliver up to 128 frames during service period instead of 8 if
unlimited is specified by the client during association.
8 was just an arbitrary value; so is 128 since unlimited can
be any number.

However for large traffic bursts, increasing this value looks
reasonable. Also, it seems that a few certification tests
expect more frames to be delivered during SP.
Signed-off-by: NAndrei Otcheretianski <andrei.otcheretianski@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

During reconfig the station list is traversed in order and station are
added back to the driver. Make sure the stations are added to the driver
in the same order they were added to mac80211.

This has a real side effect - some drivers (iwlwifi) require TDLS
stations to be added only after the AP station for the same network.
Signed-off-by: NArik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Our legal structure changed at some point (see wikipedia), but
we forgot to immediately switch over to the new copyright
notice.

For files that we have modified in the time since the change,
add the proper copyright notice now.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

sta_set_sinfo is obviously takes data for specific station.
This specific station is attached to a specific virtual
interface. Hence we should use the dtim_period from this
virtual interface rather than the system wide dtim_period.
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

In ieee80211_sta_ps_deliver_wakeup, sdata->smps_mode is checked. This is
initialized only for the base AP interface, not the individual VLANs.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

We currently track the QoS capability twice: for all peer stations
in the WLAN_STA_WME flag, and for any clients associated to an AP
interface separately for drivers in the sta->sta.wme field.

Remove the WLAN_STA_WME flag and track the capability only in the
driver-visible field, getting rid of the limitation that the field
is only valid in AP mode.
Reviewed-by: NArik Nemtsov <arik@wizery.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

do_posix_clock_monotonic_gettime() is a leftover from the initial
posix timer implementation which maps to ktime_get_ts().
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Currently, cfg80211 tries to implement ethtool, but that doesn't
really scale well, with all the different operations. Make the
lower-level driver responsible for it, which currently only has
an effect on mac80211. It will similarly not scale well at that
level though, since mac80211 also has many drivers.

To cleanly implement this in mac80211, introduce a new file and
move some code to appropriate places.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

It is currently possible to have a race due to the station PS
unblock work like this:
 * station goes to sleep with frames buffered in the driver
 * driver blocks wakeup
 * station wakes up again
 * driver flushes/returns frames, and unblocks, which schedules
   the unblock work
 * unblock work starts to run, and checks that the station is
   awake (i.e. that the WLAN_STA_PS_STA flag isn't set)
 * we process a received frame with PM=1, setting the flag again
 * ieee80211_sta_ps_deliver_wakeup() runs, delivering all frames
   to the driver, and then clearing the WLAN_STA_PS_DRIVER and
   WLAN_STA_PS_STA flags

In this scenario, mac80211 will think that the station is awake,
while it really is asleep, and any TX'ed frames should be filtered
by the device (it will know that the station is sleeping) but then
passed to mac80211 again, which will not buffer it either as it
thinks the station is awake, and eventually the packets will be
dropped.

Fix this by moving the clearing of the flags to exactly where we
learn about the situation. This creates a problem of reordering,
so introduce another flag indicating that delivery is being done,
this new flag also queues frames and is cleared only while the
spinlock is held (which the queuing code also holds) so that any
concurrent delivery/TX is handled correctly.
Reported-by: NAndrei Otcheretianski <andrei.otcheretianski@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

If the rate control algorithm uses a selection table, it
is leaked when the station is destroyed - fix that.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Reported-by: NChristophe Prévotaux <cprevotaux@nltinc.com>
Fixes: 0d528d85 ("mac80211: improve the rate control API")
Cc: stable@vger.kernel.org # v3.10+
[add commit log entry, remove pointless NULL check]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The BUG_ON(!err) can't be triggered in the code path, so remove
it.
Signed-off-by: NZhao, Gang <gamerh2o@gmail.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The patch "mac80211: implement SMPS for AP" has caused kernel
oops at mesh STA if the peer mesh STA operates in sleep mode
and then becomes active mode. It can be easily reproduced by
setting the following commands at peer mesh STA:

iw mesh0 station set aa:bb:cc:dd:ee:ff mesh_power_mode deep
iw mesh0 station set aa:bb:cc:dd:ee:ff mesh_power_mode active

Kernel oops will happen at mesh STA aa:bb:cc:dd:ee:ff.

Fix this by avoiding SMPS for mesh mode.
Signed-off-by: NChun-Yeow Yeoh <yeohchunyeow@gmail.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Avoid leaking data by sending uninitialized memory and setting an
invalid (non-zero) fragment number (the sequence number is ignored
anyway) by setting the seq_ctrl field to zero.

Cc: stable@vger.kernel.org
Fixes: 3f52b7e3 ("mac80211: mesh power save basics")
Fixes: ce662b44 ("mac80211: send (QoS) Null if no buffered frames")
Reviewed-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Consider the following (relatively unlikely) scenario:
 1) station goes to sleep while frames are buffered in driver
 2) driver blocks wakeup (until no more frames are buffered)
 3) station wakes up again
 4) driver unblocks wakeup

In this case, the current mac80211 code will do the following:
 1) WLAN_STA_PS_STA set
 2) WLAN_STA_PS_DRIVER set
 3) - nothing -
 4) WLAN_STA_PS_DRIVER cleared

As a result, no frames will be delivered to the client, even
though it is awake, until it sends another frame to us that
triggers ieee80211_sta_ps_deliver_wakeup() in sta_ps_end().

Since we now take the PS spinlock, we can fix this while at
the same time removing the complexity with the pending skb
queue function. This was broken since my commit 50a9432d
("mac80211: fix powersaving clients races") due to removing
the clearing of WLAN_STA_PS_STA in the RX path.

While at it, fix a cleanup path issue when a station is
removed while the driver is still blocking its wakeup.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

There's a race condition in mac80211 because we add stations
to the internal lists after adding them to the driver, which
means that (for example) the following can happen:
 1. a station connects and is added
 2. first, it is added to the driver
 3. then, it is added to the mac80211 lists

If the station goes to sleep between steps 2 and 3, and the
firmware/hardware records it as being asleep, mac80211 will
never instruct the driver to wake it up again as it never
realized it went to sleep since the RX path discarded the
frame as a "spurious class 3 frame", no station entry was
present yet.

Fix this by adding the station in software first, and only
then adding it to the driver. That way, any state that the
driver changes will be reflected properly in mac80211's
station state. The problematic part is the roll-back if the
driver fails to add the station, in that case a bit more is
needed. To not make that overly complex prevent starting BA
sessions in the meantime.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

There is a race between the TX path and the STA wakeup: while
a station is sleeping, mac80211 buffers frames until it wakes
up, then the frames are transmitted. However, the RX and TX
path are concurrent, so the packet indicating wakeup can be
processed while a packet is being transmitted.

This can lead to a situation where the buffered frames list
is emptied on the one side, while a frame is being added on
the other side, as the station is still seen as sleeping in
the TX path.

As a result, the newly added frame will not be send anytime
soon. It might be sent much later (and out of order) when the
station goes to sleep and wakes up the next time.

Additionally, it can lead to the crash below.

Fix all this by synchronising both paths with a new lock.
Both path are not fastpath since they handle PS situations.

In a later patch we'll remove the extra skb queue locks to
reduce locking overhead.

BUG: unable to handle kernel
NULL pointer dereference at 000000b0
IP: [<ff6f1791>] ieee80211_report_used_skb+0x11/0x3e0 [mac80211]
*pde = 00000000
Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
EIP: 0060:[<ff6f1791>] EFLAGS: 00210282 CPU: 1
EIP is at ieee80211_report_used_skb+0x11/0x3e0 [mac80211]
EAX: e5900da0 EBX: 00000000 ECX: 00000001 EDX: 00000000
ESI: e41d00c0 EDI: e5900da0 EBP: ebe458e4 ESP: ebe458b0
 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
CR0: 8005003b CR2: 000000b0 CR3: 25a78000 CR4: 000407d0
DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
DR6: ffff0ff0 DR7: 00000400
Process iperf (pid: 3934, ti=ebe44000 task=e757c0b0 task.ti=ebe44000)
iwlwifi 0000:02:00.0: I iwl_pcie_enqueue_hcmd Sending command LQ_CMD (#4e), seq: 0x0903, 92 bytes at 3[3]:9
Stack:
 e403b32c ebe458c4 00200002 00200286 e403b338 ebe458cc c10960bb e5900da0
 ff76a6ec ebe458d8 00000000 e41d00c0 e5900da0 ebe458f0 ff6f1b75 e403b210
 ebe4598c ff723dc1 00000000 ff76a6ec e597c978 e403b758 00000002 00000002
Call Trace:
 [<ff6f1b75>] ieee80211_free_txskb+0x15/0x20 [mac80211]
 [<ff723dc1>] invoke_tx_handlers+0x1661/0x1780 [mac80211]
 [<ff7248a5>] ieee80211_tx+0x75/0x100 [mac80211]
 [<ff7249bf>] ieee80211_xmit+0x8f/0xc0 [mac80211]
 [<ff72550e>] ieee80211_subif_start_xmit+0x4fe/0xe20 [mac80211]
 [<c149ef70>] dev_hard_start_xmit+0x450/0x950
 [<c14b9aa9>] sch_direct_xmit+0xa9/0x250
 [<c14b9c9b>] __qdisc_run+0x4b/0x150
 [<c149f732>] dev_queue_xmit+0x2c2/0xca0

Cc: stable@vger.kernel.org
Reported-by: NYaara Rozenblum <yaara.rozenblum@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Reviewed-by: NStanislaw Gruszka <sgruszka@redhat.com>
[reword commit log, use a separate lock]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

If a uAPSD service period ends with an MMPDU, we currently just
send that MMPDU, but it obviously won't get the EOSP bit set as
it doesn't have a QoS header. This contradicts the standard, so
add a QoS-nulldata frame after the MMPDU to properly terminate
the service period with a frame that has EOSP set.

Also fix a bug wrt. the TID for the MMPDU, it shouldn't be set
to 0 unconditionally but use the actual TID that was assigned.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When a response for PS-Poll or a uAPSD trigger frame is sent, the
more-data bit should be set according to 802.11-2012 11.2.1.5 h),
meaning that it should indicate more data on the relevant ACs
(delivery-enabled or nondelivery-enabled for uAPSD or PS-Poll.)

In, for example, the following scenario:
 * 1 frame on VO queue (either in driver or in mac80211)
 * at least 1 frame on VI queue (in the driver)
 * both VO/VI are delivery-enabled
 * uAPSD trigger frame received

The more-data flag to the driver would not be set, even though
it should be.

While fixing this, I noticed that we should really release frames
from multiple ACs where there's data buffered in the driver for
the corresponding TIDs.

To address all this, restructure the code a bit to consider all
ACs if we only release driver frames or only buffered frames.
This also addresses the more-data bug described above as now the
TIDs will all be marked as released, so the driver will have to
check the number of frames.

While at it, clarify some code and comments and remove the found
variable, replacing it with the appropriate sw/hw release check.
Reported-by: NEliad Peller <eliad@wizery.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Using ffs() for the PS-Poll release TID is wrong, it will cause
frames to be released in order 0 1 2 3 4 5 6 7 instead of the
correct 7 6 5 4 3 0 2 1. Fix this by adding a new function that
implements "highest priority TID" properly.
Reported-by: NEliad Peller <eliad@wizery.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When the station's TX latency data structures need to be
allocated, handle failures properly and also free all the
structures if there are any other problems.

Move the allocation code up so that allocation failures
don't trigger rate control algorithm calls.
Reported-by: NZHAO Gang <gamerh2o@gmail.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This is useful for debugging issues with drivers using this
function (erroneously), so add tracing for the API call.

Change-Id: Ice9d7eabb8fecbac188f0a741920d3488de700ec
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Teach sta_info_flush() to optionally also remove stations
from all VLANs associated with an AP interface to optimise
the station removal (in particular, synchronize_net().)

To not have to add the vlans argument throughout, do some
refactoring.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

There's no reason to have one synchronize_net() for each
removed station, refactor the code slightly to have just
a single synchronize_net() for all stations.

Note that this is currently useless as hostapd removes
stations one by one and this coalescing never happens.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

There's no reason to do this inside the sta key removal
since the keys can only be reached through the sta (and
not by the driver at all) so once the sta can no longer
be reached, the keys are safe.

This will allow further optimisation opportunities with
multiple stations.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

If we can assume that stations are never referenced by the
driver after sta_state returns (and this is true since the
previous iwlmvm patch and for all other drivers) then we
don't need to delay station destruction, and don't need to
play tricks with rcu_barrier() etc.

This should speed up some scenarios like hostapd shutdown.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The pointer should be cleared before synchronize_rcu() so that the
consequently dead station won't be found by any lookups in the TX
or RX paths.

Also check that the station is actually the one being removed, the
check is not needed because each 4-addr VLAN can only have a single
station and non-4-addr VLANs always have a NULL pointer there, but
the code is clearer this way (and we avoid the memory write.)
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Currently, mac80211 allows drivers to keep RCU-protected station
references that are cleared when the station is removed from the
driver and consequently needs to synchronize twice, once before
removing the station from the driver (so it can guarantee that
the station is no longer used in TX towards the driver) and once
after the station is removed from the driver.

Add a new pre-RCU-synchronisation station removal operation to
the API to allow drivers to clear/invalidate their RCU-protected
station pointers before the RCU synchronisation.

This will allow removing the second synchronisation by changing
the driver API so that the driver may no longer assume a valid
RCU-protected pointer after sta_remove/sta_state returns.

The alternative to this would be to synchronize_rcu() in all the
drivers that currently rely on this behaviour (only iwlmvm) but
that would defeat the purpose.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>