Extend nl80211 to report an exponential weighted moving average (EWMA) of the
signal value. Since the signal value usually fluctuates between different
packets, an average can be more useful than the value of the last packet.

This uses the recently added generic EWMA library function.

--
v2:	fix ABI breakage and change factor to be a power of 2.
Signed-off-by: NBruno Randolf <br1@einfach.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This reverts commit 86107fd1.

This patch inadvertantly changed the userland ABI.
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Extend nl80211 to report an exponential weighted moving average (EWMA) of the
signal value. Since the signal value usually fluctuates between different
packets, an average can be more useful than the value of the last packet.

This uses the recently added generic EWMA library function.
Signed-off-by: NBruno Randolf <br1@einfach.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The code to handle powersaving stations has a race:
when the powersave flag is lifted from a station,
we could transmit a packet that is being processed
for TX at the same time right away, even if there
are other frames queued for it. This would cause
frame reordering. To fix this, lift the flag only
under the appropriate lock that blocks TX.

Additionally, the code to allow drivers to block a
station while frames for it are on the HW queue is
never re-enabled the station, so traffic would get
stuck indefinitely. Fix this by clearing the flag
for this appropriately.

Finally, as an optimisation, don't do anything if
the driver unblocks an already unblocked station.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This adds API to allow adding per-station GTKs,
updates mac80211 to support it, and also allows
drivers to remove a key from hwaccel again when
this may be necessary due to multiple GTKs.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When roaming while we have active BA session,
we can end up transmitting delBA frames to
the old AP while we're already on the new AP's
channel, which can cause warnings.

Simply avoid sending those frames, but still
tear down the internal session state, since
they are not really necessary anyway as we
will implicitly disassociate when sending the
association to the new AP.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Acked-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The old ieee80211_find_sta_by_hw method didn't properly
find VIFS when there was more than one per AP.  This caused
AMPDU logic in ath9k to get the wrong VIF when trying to
account for transmitted SKBs.

This patch changes ieee80211_find_sta_by_hw to take a
localaddr argument to distinguish between VIFs with the
same AP but different local addresses.  The method name
is changed to ieee80211_find_sta_by_ifaddr.
Signed-off-by: NBen Greear <greearb@candelatech.com>
Acked-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Instead of using a WARN_ON(!mutex_is_locked())
use lockdep_assert_held() which compiles away
completely when lockdep isn't enabled, and
also is a more accurate assertion since it
checks that the current thread is holding the
mutex.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

sta_info_get_bss() is used to match STA pointers
for VLAN/AP interfaces, but if the same station
is also added to multiple other interfaces it
will erroneously match because both pointers are
NULL, fix this by ignoring NULL pointers here.
Reported-by: NBen Greear <greearb@candelatech.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Standardize logging messages from
	printk(KERN_<level> "%s: " fmt , wiphy_name(foo), args);
to
	wiphy_<level>(foo, fmt, args);
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Key locking simplification removed key->sdata != NULL verification from
ieee80211_key_free(). While that is fine for most use cases, there is one
path where this function can be called with an unlinked key (i.e.,
key->sdata == NULL && key->local == NULL). This results in a NULL pointer
dereference with the current implementation. This is known to happen at
least with FT protocol when wpa_supplicant tries to configure the key
before association.

Avoid the issue by passing in the local pointer to
ieee80211_key_free(). In addition, do not clear the key from hw_accel
or debugfs if it has not yet been added. At least the hw_accel one could
trigger another NULL pointer dereference.
Signed-off-by: NJouni Malinen <j@w1.fi>
Reviewed-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

To prepare for allowing drivers to sleep in
ampdu_action, change the locking in the RX
aggregation code to use a mutex, so that it
would already allow drivers to sleep. But
explicitly disable BHs around the callback
for now since the TX part cannot yet sleep,
and drivers' locking might require it.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Move the block-ack session works into common
code, since it will be needed for RX agg too
in the next patches.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When the driver or rate control requests starting
or stopping an aggregation session, that currently
causes a direct callback into the driver, which
could potentially cause locking problems. Also,
the functions need to be callable from contexts
that cannot sleep, and thus will interfere with
making the ampdu_action callback sleeping.

To address these issues, add a new work item for
each station that will process any start or stop
requests out of line.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Currently we allocate some memory for each TX
aggregation session and additionally keep a
state bitmap indicating the state it is in.
By using RCU to protect the pointer, moving
the state into the structure and some locking
trickery we can avoid locking when the TX agg
session is fully operational.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Since I recently made station management able
to sleep, I can now rework key management as
well; since it will no longer need a spinlock
and can also use a mutex instead, a bunch of
code to allow drivers' set_key to sleep while
key management is protected by a spinlock can
now be removed.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

- C99 knows about USHRT_MAX/SHRT_MAX/SHRT_MIN, not
  USHORT_MAX/SHORT_MAX/SHORT_MIN.

- Make SHRT_MIN of type s16, not int, for consistency.

[akpm@linux-foundation.org: fix drivers/dma/timb_dma.c]
[akpm@linux-foundation.org: fix security/keys/keyring.c]
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Acked-by: NWANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Both of these functions can currently return
a station pointer that, to the driver, is
invalid (in IBSS mode only) because adding
the station failed. Check for that, and also
make ieee80211_find_sta() properly use the
per interface station search.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The sta_cleanup timer is used to periodically expire buffered frames from the
tx buf. The timer is executing periodically, regardless of the need for it.
This is wasting resources.

Fix this simply by not restarting the sta_cleanup timer if the tx buffer was
empty. Restart the timer when there is some more tx-traffic.

Cc: Janne Ylälehto <janne.ylalehto@nokia.com>
Signed-off-by: NJuuso Oikarinen <juuso.oikarinen@nokia.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Enhance tracing by adding tracing for a variety of
callbacks that the drivers call, and also for
internal calls (currently limited to queue status).
This can aid debugging what is going on in mac80211
in interaction with drivers, since we can now see
what drivers call and not just what mac80211 calls
in the driver.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The aggregation code has a number of quirks, like
inventing an unneeded WLAN_BACK_TIMER value and
leaking memory under certain circumstances during
station destruction. Fix these issues by using
the regular aggregation session teardown code and
blocking new aggregation sessions, all before the
station is really destructed.

As a side effect, this gets rid of the long code
block to destroy aggregation safely.

Additionally, rename tid_state_rx which can only
have the values IDLE and OPERATIONAL to
tid_active_rx to make it easier to understand
that there is no bitwise stuff going on on the
RX side -- the TX side remains because it needs
to keep track of the driver and peer states.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When a station w/o a key is destroyed, or when
a driver submits work for a station and thereby
references it again, it seems like potentially
we could reference the station structure while
it is being destroyed.

Wait for an RCU grace period to elapse before
finishing destroying the station after we have
removed the station from the driver and from
the hash table etc., even in the case where no
key is associated with the station.

Also, there's no point in deleting the plink
timer here since it'll be properly deleted just
a bit later.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The new RCU lockdep support warns about these
in some contexts -- make it aware of the locks
used to protect all this. Different locks are
used in different contexts which unfortunately
means we can't get perfect checking.

Also remove rcu_dereference() from two places
that don't actually dereference the pointers.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Commit 34e89507 introduced sta_mtx
locking into sta_info_insert() (now sta_info_insert_rcu), but forgot
to unlock this mutex on one of the error paths. Fix this by adding
the missing mutex_unlock() call for the case where STA insert fails
due to an entry existing already. This may happen at least in AP mode
when a STA roams between two BSSes (vifs).
Signed-off-by: NJouni Malinen <j@w1.fi>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Many drivers would like to sleep during station
addition and removal, and currently have a high
complexity there from not being able to.

This introduces two new callbacks sta_add() and
sta_remove() that drivers can implement instead
of using sta_notify() and that can sleep, and
the new sta_add() callback is also allowed to
fail.

The reason we didn't do this previously is that
the IBSS code wants to insert stations from the
RX path, which is a tasklet, so cannot sleep.
This patch will keep the station allocation in
that path, but moves adding the station to the
driver out of line. Since the addition can now
fail, we can have IBSS peer structs the driver
rejected -- in that case we still talk to the
station but never tell the driver about it in
the control.sta pointer. If there will ever be
a driver that has a low limit on the number of
stations and that cannot talk to any stations
that are not known to it, we need to do come up
with a new strategy of handling larger IBSSs,
maybe quicker expiry or rejecting peers.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Since the per-vif station changes, sta_info_get on the ap sdata no
longer returns entries for stations on ap vlans. This causes issues
with hostapd, which currently always passes the ap interface name to
nl80211 calls. This patch provides bug compatibility with the earlier
versions until hostapd is fixed.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When, for instance, a new IBSS peer is found, userspace
wants to be notified. Add events for all new stations
that mac80211 learns about.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Instead of always using netif_running(sdata->dev)
use ieee80211_sdata_running(sdata) now which is
just an inline containing netif_running() for now.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

It's not all that useful to have the vif/sdata pointer,
we'd rather refer to the interfaces by their name.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

For bluetooth 3, we will most likely not have
a netdev for a virtual interface (sdata), so
prepare for that by reducing the reliance on
having a netdev. This patch moves the name
and address fields into the sdata struct and
uses them from there all over. Some work is
needed to keep them sync'ed, but that's not
a lot of work and in slow paths anyway.

In doing so, this also reduces the number of
pointer dereferences in many places, because
of things like sdata->dev->dev_addr becoming
sdata->vif.addr.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The station management currently uses the virtual
interface, but you cannot add the same station to
multiple virtual interfaces if you're communicating
with it in multiple ways.

This restriction should be lifted so that in the
future we can, for instance, support bluetooth 3
with an access point that mac80211 is already
associated to.

We can do that by requiring all sta_info_get users
to provide the virtual interface and making the RX
code aware that an address may match more than one
station struct. Thanks to the previous patches this
one isn't all that large and except for the RX and
TX status paths changes has low complexity.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Some devices implement the entire rate control in
firmware in some way, like wl1271 or like iwlwifi
which does some things in software but not a lot.
Therefore generic software rate control is rather
useless for them and just adds avoidable overhead
to the transmit path.

It's fairly simple to let drivers indicate that
they do not need rate control, but they need to
fulfil a number of conditions that we encode in
WARN_ONs.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Instead of filtering by device, directly look up by sdata.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

In some situations it might be useful to run a network with an
Access Point and multiple clients, but with each client bridged
to a network behind it. For this to work, both the client and the
AP need to transmit 4-address frames, containing both source and
destination MAC addresses.
With this patch, you can configure a client to communicate using
only 4-address frames for data traffic.
On the AP side you can enable 4-address frames for individual
clients by isolating them in separate AP VLANs which are configured
in 4-address mode.
Such an AP VLAN will be limited to one client only, and this client
will be used as the destination for all traffic on its interface,
regardless of the destination MAC address in the packet headers.
The advantage of this mode compared to regular WDS mode is that it's
easier to configure and does not require a static list of peer MAC
addresses on any side.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Some devices require that all frames to a station
are flushed when that station goes into powersave
mode before being able to send frames to that
station again when it wakes up or polls -- all in
order to avoid reordering and too many or too few
frames being sent to the station when it polls.

Normally, this is the case unless the station
goes to sleep and wakes up very quickly again.
But in that case, frames for it may be pending
on the hardware queues, and thus races could
happen in the case of multiple hardware queues
used for QoS/WMM. Normally this isn't a problem,
but with the iwlwifi mechanism we need to make
sure the race doesn't happen.

This makes mac80211 able to cope with the race
with driver help by a new WLAN_STA_PS_DRIVER
per-station flag that can be controlled by the
driver and tells mac80211 whether it can transmit
frames or not. This flag must be set according to
very specific rules outlined in the documentation
for the function that controls it.

When we buffer new frames for the station, we
normally set the TIM bit right away, but while
the driver has blocked transmission to that sta
we need to avoid that as well since we cannot
respond to the station if it wakes up due to the
TIM bit. Once the driver unblocks, we can set
the TIM bit.

Similarly, when the station just wakes up, we
need to wait until all other frames are flushed
before we can transmit frames to that station,
so the same applies here, we need to wait for
the driver to give the OK.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Since we have a TODO item to make all station
management dependent on virtual interfaces, I
figured I'd start with pushing such a change
to drivers before more drivers start using the
ieee80211_find_sta() API with a hw pointer and
cause us grief later on.

For now continue exporting the old API in form
of ieee80211_find_sta_by_hw(), but discourage
its use strongly.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When receiving data frames, we can send them only to
the interface they belong to based on transmitting
station (this doesn't work for probe requests). Also,
don't try to handle other frames for AP_VLAN at all
since those interface should only receive data.

Additionally, the transmit side must check that the
station we're sending a frame to is actually on the
interface we're transmitting on, and not transmit
packets to functions that live on other interfaces,
so validate that as well.

Another bug fix is needed in sta_info.c where in the
VLAN case when adding/removing stations we overwrite
the sdata variable we still need.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Cc: stable@kernel.org
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

In order for userspace to be able to figure out whether
it obtained a consistent snapshot of data or not when
using netlink dumps, we need to have a generation number
in each dump message that indicates whether the list has
changed or not -- its value is arbitrary.

This patch adds such a number to all dumps, this needs
some mac80211 involvement to keep track of a generation
number to start with when adding/removing mesh paths or
stations.

The wiphy and netdev lists can be fully handled within
cfg80211, of course, but generation numbers need to be
stored there as well.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We forgot to cancel all timers in mac80211 when suspending.
In particular we forgot to deal with some things that can
cause hardware reconfiguration -- while it is down.

While at it we go ahead and add a warning in ieee80211_sta_work()
if its run while the suspend->resume cycle is in effect. This
should not happen and if it does it would indicate there is
a bug lurking in either mac80211 or mac80211 drivers.

With this now wpa_supplicant doesn't blink when I go to suspend
and resume where as before there where issues with some timers
running during the suspend->resume cycle. This caused a lot of
incorrect assumptions and would at times bring back the device
in an incoherent, but mostly recoverable, state.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>