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>

Unfortunately, commit b22cfcfc, intended to speed up roaming
by avoiding the synchronize_rcu() broke AP/mesh modes as it moved
some code into that work item that will still call into the driver
at a time where it's no longer expected to handle this: after the
AP or mesh has been stopped.

To fix this problem remove the per-station work struct, maintain a
station cleanup list instead and flush this list when stations are
flushed. To keep this patch smaller for stable, do this when the
stations are flushed (sta_info_flush()). This unfortunately brings
back the original roaming delay; I'll fix that again in a separate
patch.

Also, Ben reported that the original commit could sometimes (with
many interfaces) cause long delays when an interface is set down,
due to blocking on flush_workqueue(). Since we now maintain the
cleanup list, this particular change of the original patch can be
reverted.

Cc: stable@vger.kernel.org [3.7]
Reported-by: NBen Greear <greearb@candelatech.com>
Tested-by: NBen Greear <greearb@candelatech.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Currently the logic to fill a struct rate_info with
a STA's last RX rate is accessible only in the cfg.c.
As the RX rate calculation might be needed elsewhere,
split this out into a separate function.
Signed-off-by: NSaravana <saravanad@posedge.com>
[fix various whitespace issues, reword commit log]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Add a debugfs file showing the signal strength
of the ack frame that is received for the
currently sent tx packet
Signed-off-by: NSaravana <saravanad@posedge.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Add support to mac80211 for having drivers report
received VHT MCS information.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Convert mac80211 (and where necessary, some drivers a
little bit) to the new channel definition struct.

This will allow extending mac80211 for VHT, which is
currently restricted to channel contexts since there
are no drivers using that which makes it easier. As
I also don't care about VHT for drivers not using the
channel context API, I won't convert the previous API
to VHT support.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Introduce IEEE80211_NUM_TIDS in the generic 802.11
header file and use it in place of STA_TID_NUM and
NUM_RX_DATA_QUEUES which are both really the number
of TIDs.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

mac80211 calls synchronize_rcu() on sta deletion,
which increase the roaming time significantly.

Convert it into a call_rcu() mechanism, in order
to avoid blocking. Since some of the cleanup
functions might sleep, schedule from the call_rcu
callback a new work that will do the actual cleanup.

In order to make sure the cleanup occurs before
the interface went down, flush local->workqueue
on ieee80211_do_stop().
Signed-off-by: NYoni Divinsky <yoni.divinsky@ti.com>
Signed-off-by: NEliad Peller <eliad@wizery.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Add a few kernel-doc descriptions that were missed
during mesh development.
Reported-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAshok Nagarajan <ashok@cozybit.com>
Acked-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Add a few kernel-doc descriptions that were missed
during development.
Reported-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

spatch/coccinelle isn't perfect.  It doesn't understand
__aligned(x) and doesn't convert functions it can't parse.

Convert the remaining compare_ether_addr uses.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Section 9.23.3.5 of IEEE 80211s standard describes the protection rules for
HT mesh STA in a MBSS. Three HT protection modes are supported for now:

non-HT mixed mode - is selected if any non-HT peers are present in our MBSS.
20MHz-protection mode - is selected if all peers in our 20/40MHz MBSS support
			HT and atleast one HT20 peer is present.
no-protection mode - is selected otherwise.

This is a limited implementation of 9.23.3.5, which only considers mesh peers
when determining the HT protection mode. Station's channel_type needs to be
maintained.
Signed-off-by: NAshok Nagarajan <ashok@cozybit.com>
Reviewed-by: NThomas Pedersen <thomas@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch adds MBSS extensible synchronization framework (Sec.
13.13.2 of IEEE Std. 802.11-2012).

The framework is implemented via an ops table which defines the
following functions:

    rx_bcn_presp() - this is called every time a mesh beacon is
received.
    adjust_tbtt() - this is called immediately before a beacon is about
to be transmitted.

The default neighbor offset synchronization defined in the standard is
implemented.  We also provide template functions for vendor specific
methods.

When neighbor offset synchronization is active (which is the default)
mesh neighbors in the same MBSS will track timing offsets to each other
and compensate clock drift.

In our tests we observed that this mesh synchronization implementation
successfully corrected drifts between stations of ~2PPM while
introducing a jitter of ~20us.

It is also possible to test this framework on mac80211_hwsim simulated
phys to see how it behaves under different topologies, over poor links,
etc.
Signed-off-by: NMarco Porsch <marco.porsch@s2005.tu-chemnitz.de>
Signed-off-by: NPavel Zubarev <pavel.zubarev@gmail.com>
Signed-off-by: NJavier Cardona <javier@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The channel type argument to the rate_update()
callback isn't really the correct way to give
the rate control algorithm about the desired
RX bandwidth of the peer.

Remove this argument, and instead update the
STA capabilities with 20/40 appropriately. The
SMPS update done by this callback works in the
same way, so this makes the callback cleaner.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Calling mod_timer from the rx/tx hotpath is somewhat expensive, and the
timeout doesn't need to be so precise.

Switch to a different strategy: Schedule the timer initially, store jiffies
of all last rx/tx activity which would previously modify the timer, and
let the timer re-arm itself after checking the last rx/tx timestamp.
Make the session timers deferrable to avoid causing extra wakeups on systems
running on battery.
This visibly reduces CPU load under high network load on small embedded
systems.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Airtime link metric estimation was broken in HT mesh, use
cfg80211_calculate_bitrate to get the right rate value.

Also factor out tx rate copying from sta_set_sinfo().
Signed-off-by: NThomas Pedersen <thomas@cozybit.com>
Reviewed-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Because of the constant size and guaranteed 16 bit alignment, the inline
compare_ether_addr function is much cheaper than calling memcmp.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Acked-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

There are situations where we don't have the
necessary rate control information yet for
station entries, e.g. when associating. This
currently doesn't really happen due to the
dummy station handling; explicitly disabling
rate control when it's not initialised will
allow us to remove dummy stations.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

There are situations where we don't have the
necessary rate control information yet for
station entries, e.g. when associating. This
currently doesn't really happen due to the
dummy station handling; explicitly disabling
rate control when it's not initialised will
allow us to remove dummy stations.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The dummy STA support was added because I didn't
want to change the driver API at the time. Now
that we have state transitions triggering station
add/remove in the driver, we only call add once a
station reaches ASSOCIATED, so we can remove the
dummy station stuff again.

While at it, tighten the RX check and accept only
port control (EAP) frames from the AP station if
it's not associated yet -- in other cases there's
no race.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

(based on Eliad's patch)

Add a callback to notify the low-level driver whenever
the state of a station changes. The driver is only
notified when the station is actually in the mac80211
hash table, not for pre-insert state transitions.

To allow the driver to replace sta_add/remove calls
with this, call extra transitions with the NOTEXIST
state.

This callback can fail, so we need to be careful in
handling it when a station is inserted, particularly
in the IBSS case where we still keep the station entry
around for mac80211 purposes.
Signed-off-by: NEliad Peller <eliad@wizery.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This will be used by drivers later if they
need to have stations inserted all the time,
in mac80211 has no purpose, is never used
and sta_state starts out in NONE.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

In the future, when we start notifying drivers,
state transitions could potentially fail. To make
it easier to distinguish between programming bugs
and driver failures:
 * rename sta_info_move_state() to
   sta_info_pre_move_state() which can only be
   called before the station is inserted (and
   check this with a new station flag).
 * rename sta_info_move_state_checked() to just
   plain sta_info_move_state(), as it will be
   the regular function that can fail for more
   than just one reason (bad transition or an
   error from the driver)

This makes the programming model easier -- one of
the functions can only be called before insertion
and can't fail, the other can fail.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

If station info contains a beacon loss count, return
it to userspace.
Signed-off-by: NPaul Stewart <pstew@chromium.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

  Currently code allows three (HT_AGG_MAX_RETRIES) unanswered addba
requests. When this limit is reached aggregation is turned off for
given TID permanently. This doesn't seem right: three requests is
not that much, some 'blackout' can happen, but effect of it affects
whole connection indefinitely.
  This patch increases number of retries to 15. Also, when there have
been 3 or more retries it splits further retries apart by 15 seconds
instead of sending them in very short period of time.
Signed-off-by: NNikolay Martynov <mar.kolya@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

No real changes, just note that they are const.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Station entries can have various states, the most
important ones being auth, assoc and authorized.
This patch prepares us for telling the driver about
these states, we don't want to confuse drivers with
strange transitions, so with this we enforce that
they move in the right order between them (back and
forth); some transitions might happen before the
driver even knows about the station, but at least
runtime transitions will be ordered correctly.

As a consequence, IBSS and MESH stations will now
have the ASSOC flag set (so they can transition to
AUTHORIZED), and we can get rid of a special case
in TX processing.

When freeing a station, unwind the state so that
other parts of the code (or drivers later) can rely
on the transitions.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NMohammed Shafi Shajakhan <mohammed@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

  Currently tx aggregation is not being timed out even if timeout is
specified when aggregation is opened. Tx tid stays active until delba
arrives from recipient (i.e. recipient times out tid when it is
inactive).
  The problem with this approach is that delba can get lost in the air
and tx tid will stay perpetually opened on the originator while closed
on recipient thus all data sent via this tid will be lost.
  This patch implements tx tid timeouting in way very similar to rx tid
timeouting.
Signed-off-by: NNikolay Martynov <mar.kolya@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

WLAN_STA_ASSOC_AP indicates that the station entry
is for an AP we're associated to but isn't used so
remove it.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Implement the cfg80211 notification but only send
one event per associated station to avoid having
tons of events if the station thinks it should be
allowed to use 4addr frames but it isn't.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The flaglock in struct sta_info has long been
something that I wanted to get rid of, this
finally does the conversion to atomic bitops.

The conversion itself is straight-forward in
most places, a few things needed to change a
bit since we can no longer use multiple bits
at the same time.

On x86-64, this is a fairly significant code
size reduction:
   text	   data	    bss	    dec	    hex
 427861	  23648	   1008	 452517	  6e7a5	before
 425383	  23648	    976	 450007	  6ddd7	after
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

If a PS-poll frame is retried (but was received)
there is no way to detect that since it has no
sequence number. As a consequence, the standard
asks us to not react to PS-poll frames until the
response to one made it out (was ACKed or lost).

Implement this by using the WLAN_STA_SP flags to
also indicate a PS-Poll "service period" and the
IEEE80211_TX_STATUS_EOSP flag for the response
packet to indicate the end of the "SP" as usual.

We could use separate flags, but that will most
likely completely confuse drivers, and while the
standard doesn't exclude simultaneously polling
using uAPSD and PS-Poll, doing that seems quite
problematic.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Add uAPSD support to mac80211. This is probably not
possible with all devices, so advertising it with
the cfg80211 flag will be left up to drivers that
want it.

Due to my previous patches it is now a fairly
straight-forward extension. Drivers need to have
accurate TX status reporting for the EOSP frame.
For drivers that buffer themselves, the provided
APIs allow releasing the right number of frames,
but then drivers need to set EOSP and more-data
themselves. This is documented in more detail in
the new code itself.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

For uAPSD support we'll need to have per-AC PS
buffers. As this is a major undertaking, split
the buffers before really adding support for
uAPSD. This already makes some reference to the
uapsd_queues variable, but for now that will
never be non-zero.

Since book-keeping is complicated, also change
the logic for keeping a maximum of frames only
and allow 64 frames per AC (up from 128 for a
station).
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Currently, the TIM bit for a given station is set
and cleared all over the place. Since the logic to
set/clear it will become much more complex when we
add uAPSD support, as a first step let's collect
the entire logic in one place. This requires a few
small adjustments to other places.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Mark the STA entries of enabled TDLS peers with a new "peer authorized"
flag.

During link setup, allow special TDLS setup frames through the AP, but
otherwise drop all packets destined to the peer. This is required by the
TDLS (802.11z) specification in order to prevent reordering of MSDUs
between the AP and direct paths.

When setup completes and the peer is authorized, send data directly,
bypassing the AP.

In the Rx path, allow data to be received directly from TDLS peers.
Signed-off-by: NArik Nemtsov <arik@wizery.com>
Cc: Kalyan C Gaddam <chakkal@iit.edu>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When adding a TDLS peer STA, mark it with a new flag in both nl80211 and
mac80211. Before adding a peer, make sure the wiphy supports TDLS and
our operating mode is appropriate (managed).

In addition, make sure all peers are removed on disassociation.

A TDLS peer is first added just before link setup is initiated. In later
setup stages we have more info about peer supported rates, capabilities,
etc. This info is reported via nl80211_set_station().
Signed-off-by: NArik Nemtsov <arik@wizery.com>
Cc: Kalyan C Gaddam <chakkal@iit.edu>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Unfortunately failed BAR tx attempts happen more frequently than I
expected, and the resulting aggregation teardowns cause performance
issues, as the aggregation session does not always get re-established
properly.
Instead of tearing down the entire aggr session, we can simply store the
SSN of the last failed BAR tx attempt, wait for the first successful
tx status event, and then send another BAR with the same SSN.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Cc: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>