Patch vastly improve latency while scanning. Slight throughput
improvements were observed as well. Is intended for improve performance
of voice and video applications, when scan is periodically requested by
user space (i.e. default NetworkManager behaviour).

Patch remove latency requirement based on PM_QOS_NETWORK_LATENCY,
this value is 2000 seconds by default (i.e. approximately 0.5 hour !?!).

Also remove listen interval requirement, which based on beaconing and
depending on BSS parameters. It can make we stay off-channel for a
second or more.

Instead try to offer the best latency that we could, i.e. be off-channel
no longer than PASSIVE channel scan time: 125 ms. That mean we will
scan two ACTIVE channels and go back to on-channel, and one PASSIVE
channel, and go back to on-channel.

Patch also decrease PASSIVE channel scan time to about 110 ms.

As drawback patch increase overall scan time. On my tests, when scanning
both 2GHz and 5GHz bands, scanning time increase from 5 seconds up to 10
seconds. Since that increase happen only when we are associated, I think
it can be acceptable. If eventually better scan time is needed for
situations when we lose signal and quickly need to decide to which AP
roam, additional scan flag or parameter can be introduced.

I tested patch by doing:

while true; do iw dev wlan0 scan; sleep 3; done > /dev/null

and

ping -i0.2 -c 1000 HOST

on remote and local machine, results are as below:

* Ping from local periodically scanning machine to AP:
Unpatched: rtt min/avg/max/mdev = 0.928/24.946/182.135/36.873 ms
Patched:   rtt min/avg/max/mdev = 0.928/19.678/150.845/33.130 ms

* Ping from remote machine to periodically scanning machine:
Unpatched: rtt min/avg/max/mdev = 1.637/120.683/709.139/164.337 ms
Patched:   rtt min/avg/max/mdev = 1.807/26.893/201.435/40.284 ms

Throughput measured by scp show following results.

* Upload to periodically scanning machine:
Unpatched: 3.9MB/s   03:15
Patched:   4.3MB/s   02:58

* Download from periodically scanning machine:
Unpatched: 5.5MB/s   02:17
Patched:   6.2MB/s   02:02
Signed-off-by: NStanislaw Gruszka <sgruszka@redhat.com>
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>

These pointers/values are never used, remove them.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

We track this, but never use it, so we can
just remove it.
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>

When waking up from WoWLAN, it is useful to know
what triggered the wakeup. Support reporting the
wakeup reason(s) in cfg80211 (and a pass-through
in mac80211) to allow userspace to know.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The standard mandates mesh STAs to set the ERP Short Slot
Time capability info bit in beacons to 0. Even though this
is their way of disallowing short slot time for mesh STAs,
there should be no harm in enabling it if we determine all
STAs in the current MBSS support ERP rates.

Increases throughput about 20% for legacy rates when
enabled.
Signed-off-by: NThomas Pedersen <thomas@cozybit.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This is basically a revert of:

commit 5b632fe8
Author: Stanislaw Gruszka <sgruszka@redhat.com>
Date:   Mon Dec 3 12:56:33 2012 +0100

    mac80211: introduce IEEE80211_HW_TEARDOWN_AGGR_ON_BAR_FAIL

We do not need this flag any longer, rt2x00 BAR/BA problem was fixed
correctly by wireless-testing commit:

commit 84e9e8eb
Author: Helmut Schaa <helmut.schaa@googlemail.com>
Date:   Thu Jan 17 17:34:32 2013 +0100

    rt2x00: Improve TX status handling for BlockAckReq frames
Signed-off-by: NStanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Before "mac80211: clean up mesh sta allocation warning"
was applied, mesh_sta_info_get() was reshuffled to please
sparse. As a result we neglect to initialize newly created
STAs. Fix this.
Signed-off-by: NThomas Pedersen <thomas@cozybit.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

gcc cannot prove that the value of sdata->vif.type does not
change between the switch() statement and the second
comparison to NL80211_IFTYPE_AP, causing a harmless
warning.
Slightly reordering the code makes the warning go away
with no functional change.

Without this patch, building ARM at91sam9g45_defconfig with
gcc-4.6 results in:

net/mac80211/tx.c: In function 'ieee80211_subif_start_xmit':
net/mac80211/tx.c:1797:22: warning: 'chanctx_conf' may be used uninitialized in this function [-Wuninitialized]
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
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>

An existing mesh station entry may change its rate
capabilities, so call rate_control_rate_update() to notify
the rate control.
Signed-off-by: NThomas Pedersen <thomas@cozybit.com>
[fix compilation]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This refactoring fixes a "scheduling while atomic" warning
when allocating a mesh station entry while holding the RCU
read lock. Fix this by creating a new function
mesh_sta_info_get(), which correctly handles the locking
and returns under RCU.

Also move some unnecessarily #ifdefed mesh station init
code from sta_info_alloc() to __mesh_sta_info_alloc().
Signed-off-by: NThomas Pedersen <thomas@cozybit.com>
[change code flow to make sparse happy]
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>

To be able to implement NS response offloading (in
regular operation or while in WoWLAN) drivers need
to know the IPv6 addresses assigned to interfaces.
Implement an IPv6 notifier in mac80211 to call the
driver when addresses change.

Unlike for IPv4, implement it as a callback rather
than as a list in the BSS configuration, that is
more flexible.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

A lot of the aggregation messages don't indicate the
station so they're hard to understand if there are
multiple sessions in progress. Make that easier by
adding the MAC address to most messages. Also add
the TID if it wasn't already there.
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>

There are hardwares which support offload of data packets
for example when auto ARP is enabled the hw will send
the ARP response. In such cases if WEP encryption is
configured the hw must know the default WEP key in order
to encrypt the packets correctly.

When hw_accel is enabled and encryption type is set to WEP,
the driver should get the default key index from mac80211.
Signed-off-by: NYoni Divinsky <yoni.divinsky@ti.com>
[cleanups, fixes, documentation]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Some new APIs will require tracing a chandef without
it being part of a channel context, so separate out
the tracing macros for that.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Mesh PERR action frames are robust and thus may be encrypted, so add
proper head/tailroom to allow this.  Fixes this warning when operating
a Mesh STA on ath5k:

WARNING: at net/mac80211/wpa.c:427 ccmp_encrypt_skb.isra.5+0x7b/0x1a0 [mac80211]()
Call Trace:
 [<c011c5e7>] warn_slowpath_common+0x63/0x78
 [<c011c60b>] warn_slowpath_null+0xf/0x13
 [<e090621d>] ccmp_encrypt_skb.isra.5+0x7b/0x1a0 [mac80211]
 [<e090685c>] ieee80211_crypto_ccmp_encrypt+0x1f/0x37 [mac80211]
 [<e0917113>] invoke_tx_handlers+0xcad/0x10bd [mac80211]
 [<e0917665>] ieee80211_tx+0x87/0xb3 [mac80211]
 [<e0918932>] ieee80211_tx_pending+0xcc/0x170 [mac80211]
 [<c0121c43>] tasklet_action+0x3e/0x65
Signed-off-by: NBob Copeland <me@bobcopeland.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

A user reported warnings in ath5k due to transmitting frames with no
rates set up.  The frames were Mesh PERR frames, and some debugging
showed an empty control block with just the vif pointer:

>  [  562.522682] XXX txinfo: 00000000: 00 00 00 00 00 00 00 00 00 00 00
>  00 00 00 00 00  ................
>  [  562.522688] XXX txinfo: 00000010: 00 00 00 00 00 00 00 00 54 b8 f2
>  db 00 00 00 00  ........T.......
>  [  562.522693] XXX txinfo: 00000020: 00 00 00 00 00 00 00 00 00 00 00
>  00 00 00 00 00  ................

Set the IEEE80211_TX_INTFL_NEED_TXPROCESSING flag to ensure that
rate control gets run before the frame is sent.
Signed-off-by: NBob Copeland <me@bobcopeland.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Move the default mesh beacon interval and DTIM period to cfg80211
and make them accessible to nl80211. This enables setting both
values when joining an MBSS.

Previously the DTIM parameter was not set by mac80211 so the
driver's default value was used.
Signed-off-by: NMarco Porsch <marco@cozybit.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This functions will be used for mesh beacons, too.
Signed-off-by: NMarco Porsch <marco@cozybit.com>
[some formatting fixes]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The established peer link count is indicated in mesh beacons and
used for other internal tasks. Previously it was not updated when
authenticated peering is performed in userspace.
Signed-off-by: NMarco Porsch <marco@cozybit.com>
Acked-by: NThomas Pedersen <thomas@cozybit.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Allow mesh interface to disable the power save which is by default
turn on in certain chipset. Testing with 2 units of ZCN-1523H-5-16
featuring AR9280 chipset which have power save enabled by default.
Constant reset if the average signal of the peer mesh STA is below
-80 dBm and power save is enabled.
Signed-off-by: NChun-Yeow Yeoh <yeohchunyeow@gmail.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When the driver's resume function can't completely
restore the configuration in the device, it returns
1 from the callback which will be treated like a HW
restart request, but done directly.

In this case, also call the driver's restart_complete()
function so it can finish the reconfiguration there.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

My commit 529ba6e9
("mac80211: clean up association better in suspend")
introduced a bug when resuming from WoWLAN when a
device reset is desired. This case must not use the
suspend_bss_conf as it hasn't been stored.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Channel contexts are not always used with monitor interfaces. If no channel
context is set, use the oper channel, otherwise tx fails.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
[check local->use_chanctx]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Since:

commit b23b025f
Author: Ben Greear <greearb@candelatech.com>
Date:   Fri Feb 4 11:54:17 2011 -0800

    mac80211: Optimize scans on current operating channel.

we do not disable PS while going back to operational channel (on
ieee80211_scan_state_suspend) and deffer that until scan finish.
But since we are allowed to send frames, we can send a frame to AP
without PM bit set, so disable PS on AP side. Then when we switch
to off-channel (in ieee80211_scan_state_resume) we do not enable PS.
Hence we are off-channel with PS disabled, frames are not buffered
by AP.

To fix remove offchannel_ps_disable argument and always enable PS when
going off-channel and disable it when going on-channel, like it was
before.

Cc: stable@vger.kernel.org # 2.6.39+
Signed-off-by: NStanislaw Gruszka <sgruszka@redhat.com>
Tested-by: NSeth Forshee <seth.forshee@canonical.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

During FT roaming, wpa_supplicant attempts to set the
key before association. This used to be rejected, but
as a side effect of my commit 66e67e41
("mac80211: redesign auth/assoc") the key was accepted
causing hardware crypto to not be used for it as the
station isn't added to the driver yet.

It would be possible to accept the key and then add it
to the driver when the station has been added. However,
this may run into issues with drivers using the state-
based station adding if they accept the key only after
association like it used to be.

For now, revert to the behaviour from before the auth
and assoc change.

Cc: stable@vger.kernel.org
Reported-by: NCédric Debarge <cedric.debarge@acksys.fr>
Tested-by: NCédric Debarge <cedric.debarge@acksys.fr>
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>

One of the function names was wrong and some parameters were
missing.
Signed-off-by: NBob Copeland <me@bobcopeland.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The following changes are invalid and should be
disallowed when a station already exists:
 * supported rates changes, except for TDLS peers
 * listen interval changes
 * HT capability changes

Disallow them and also update a mac80211 comment
explaining how they would be racy.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When an interface is configured to a 20 MHz channel
and the device as well as the peer are 40 MHz capable
the HT capabilities of the peer are not restricted to
20 MHz, even though they're supposed to be restricted
to the currently possible capabilities.

Unset the 40 MHz HT capability bits in this case.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Support the HT notify channel width action frame
to update the rate scaling about the bandwidth
the peer can receive in.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When TX aggregation is stopped, there are a few
different cases:
 - connection with the peer was dropped
 - session stop was requested locally
 - session stop was requested by the peer
 - connection was dropped while a session is stopping

The behaviour in these cases should be different, if
the connection is dropped then the driver should drop
all frames, otherwise the frames may continue to be
transmitted, aggregated in the case of a locally
requested session stop or unaggregated in the case of
the peer requesting session stop.

Split these different cases so that the driver can
act accordingly; however, treat local and remote stop
the same way and ask the driver to not send frames as
aggregated packets any more.

In the case of connection drop, the stop callback the
driver is otherwise supposed to call is no longer
required.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

To call it from ___ieee80211_stop_tx_ba_session,
move the function and dependencies up.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Create the function ieee80211_remove_tid_tx to call
it from ___ieee80211_stop_tx_ba_session later.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>