If we have a lot of frames to transmit at once, for
instance with fragmentation, it can be an optimisation
to only tell the DMA engine about them on the last
fragment/frame to avoid banging the IO too much. This
patch allows implementation such an optimisation by
telling the driver when more frames can be expected.

Currently, this is used by mac80211 only on fragmented
frames, but could also be used in the future on other
frames when the queue was full and there are multiple
frames pending.

Note that drivers need to be careful when using this
flag, they need to kick their DMA engines not just
when this flag is clear, but also when the queue gets
full so that progress can be made.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The mac80211 workqueue exists to enable mac80211 and drivers
to queue their own work on a single threaded workqueue. mac80211
takes care to flush the workqueue during suspend but we never
really had requirements on drivers for how they should use
the workqueue in consideration for suspend.

We extend mac80211 to document how the mac80211 workqueue should
be used, how it should not be used and finally move raw access to
the workqueue to mac80211 only. Drivers and mac80211 use helpers
to queue work onto the mac80211 workqueue:

  * ieee80211_queue_work()
  * ieee80211_queue_delayed_work()

These helpers will now warn if mac80211 already completed its
suspend cycle and someone is trying to queue work. mac80211
flushes the mac80211 workqueue prior to suspend a few times,
but we haven't taken the care to ensure drivers won't add more
work after suspend. To help with this we add a warning when
someone tries to add work and mac80211 already completed the
suspend cycle.

Drivers should ensure they cancel any work or delayed work
in the mac80211 stop() callback.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When enqueuing packets on the internal packet queue, we
need to ensure that we have a valid vif pointer since
that is required since the net namespace work. Add some
assertions to verify this, but also don't crash is for
some reason we don't end up with a vif pointer -- warn
and drop the packet in all these cases.

Since this code touches a number of hotpaths, it is
intended to be temporary, or maybe configurable in the
future, at least the bit that is in the path that gets
hit for every packet, ieee80211_tx_pending().
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This was caused by patch:

"mac80211: cooperate more with network namespaces"

The version of the patch applied doesn't match Johannes' latest:

http://johannes.sipsolutions.net/patches/kernel/all/LATEST/NNN-mac80211-netns.patch

The skb->cb virtual interface data wasn't being reset for
reuse so ath9k pooped out when trying to dereference the
private rate control info from the skb.

BUG: unable to handle kernel NULL pointer dereference
RIP: 0010:[<ffffffffa0258173>] ath_tx_rc_status+0x33/0x150 [ath9k]
<-- snip etc -->
Reported-by: NDavide Pesavento <davidepesa@gmail.com>
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When a station queries us for a PS-poll response, we wrongly
queue the frame on the virtual interface's queue rather than
the pending queue.

Additionally, fix a race condition where we could potentially
send multiple frames to the sleeping station due to using a
station flag rather than a packet flag. When converting to a
packet flag, we can also convert p54 and remove the filter
clearing we added for it.

(Also remove a now dead function)
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Reported-by: NBob Copeland <me@bobcopeland.com>
Tested-by: NBob Copeland <me@bobcopeland.com>
Cc: Christian Lamparter <chunkeey@web.de>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Introduce a new scan flag "SCAN_OFF_CHANNEL" which basically tells us
that we are currently on a different channel for scanning and cannot
RX/TX. "SCAN_SW_SCANNING" tells us that we are currently running a
software scan but we might as well be on the operating channel to RX/TX.
While "SCAN_SW_SCANNING" is set during the whole scan "SCAN_OFF_CHANNEL"
is set when leaving the operating channel and unset when coming back.

Introduce two new scan states "SCAN_LEAVE_OPER_CHANNEL" and
"SCAN_ENTER_OPER_CHANNEL" which basically implement the functionality we
need to leave the operating channel (send a nullfunc to the AP and stop
the queues) and enter it again (send a nullfunc to the AP and start the
queues again).

Enhance the scan state "SCAN_DECISION" to switch back to the operating
channel after each scanned channel. In the future it sould be simple
to enhance the decision state to scan as much channels in a row as the
qos latency allows us.
Signed-off-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Use a bitfield to store the current scan mode instead of two boolean
variables {sw,hw}_scanning. This patch does not introduce functional
changes but allows us to enhance the scan flags later (for example
for background scanning).
Signed-off-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

There are still two places in mac80211 that hardcode
the initial net namespace (init_net). One of them is
mandated by cfg80211 and will be removed by a separate
patch, the other one is used for finding the network
device of a pending packet via its ifindex.

Remove the latter use by keeping track of the device
pointer itself, via the vif pointer, and avoid it
going stale by dropping pending frames for a given
interface when the interface is removed.

To keep track of the vif pointer for the correct
interface, change the info->control.vif pointer's
internal use to always be the correct vif, and only
move it to the vif the driver expects (or NULL for
monitor interfaces and injected packets) right before
giving the packet to the driver.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The removal of the master netdev broke the mesh forwarding path.  This patch
fixes it by using the new internal 'pending' queue.

As a result of this change, mesh forwarding no longer does the inefficient
802.11 -> 802.3 -> 802.11 conversion that was done before.

[Changes since v1]
Suggested by Johannes:
 - Select queue before adding to mpath queue
 - ieee80211_add_pending_skb -> ieee80211_add_pending_skbs
 - Remove unnecessary header wme.h
Signed-off-by: NJavier Cardona <javier@cozybit.com>
Signed-off-by: NAndrey Yurovsky <andrey@cozybit.com>
Reviewed-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

ieee80211_xmit() cannot be called with tasklets enabled
because it is normally called from within a tasklet.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

With the internal 'pending' queue system in place, we can simply
put packets there instead of pushing them off to the master dev,
getting rid of the master interface completely.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When we're associated we should be able to send data to
target sta. If we cannot we may be trying to use the incorrect
band to talk to the sta. Lets catch any such cases, warn, and
drop the frames to not invalidate assumptions being made on
rate control algorithms when they have a valid sta to
communicate with. Any such cases should be handled and fixed.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The location of the 802.11 header is calculated incorrectly due to a
wrong placement of parentheses.  Found by kmemcheck.
Signed-off-by: NPavel Roskin <proski@gnu.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch converts the remaining occurences of raw return values to their
symbolic counterparts in ndo_start_xmit() functions that were missed by the
previous automatic conversion.

Additionally code that assumed the symbolic value of NETDEV_TX_OK to be zero
is changed to explicitly use NETDEV_TX_OK.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Convert magic values 1 and -1 to NETDEV_TX_BUSY and NETDEV_TX_LOCKED respectively.

0 (NETDEV_TX_OK) is not changed to keep the noise down, except in very few cases
where its in direct proximity to one of the other values.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We don't want to trigger moving between PS mode during scan,
because then we will sometimes end up sending nullfunc frames
during scan. We're supposed to only send one prior to scan
and after scan.

This fixes an oops which occured due to an assert in ath9k:

http://marc.info/?l=linux-wireless&m=124277331319024

The assert was happening because the rate control algorithm
figures it should find at least one valid dual stream or
single stream rate. Since we allow mac80211 to send nullfunc
frames during scan and dynamic PS was enabled at times we ended
up trying to send nullfunc frames for the target sta on the
wrong band for which we have no valid rate to communicate with
it. This breaks the assumptions in rate control.

We determine we also need to disable moving between PS modes
when not associated so lets just add that now as well, and we
should not have a ps_sdata when that interface cannot actually
go into PS because it's not associated.
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>

The return type has more than two values, but it can validly
only ever return TX_DROP and TX_CONTINUE, so use a bool
instead of ieee80211_tx_result.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

In order to handle powersave frames properly we had needed
to pass these out to the device queues again, and introduce
the skb->requeue bit. This, however, also has unnecessary
overhead by needing to 'clean up' already tried frames, and
this clean-up code is also buggy when software encryption
is used.

Instead of sending the frames via the master netdev queue
again, simply put them into the pending queue. This also
fixes a problem where frames for that particular station
could be reordered when some were still on the software
queues and older ones are re-injected into the software
queue after them.
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>

When updating the duration field for TX frames, skip the update for
PS-Poll frames that use this field for other purposes (AID).
Signed-off-by: NJouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

There's this internal wifi_wme_noack_test variable that
we use to set the QoS control if set. For one, it is
unlikely that it is set. Secondly, if set it needs to
influence the IEEE80211_TX_CTL_NO_ACK TX control flag,
and finally we should also be able to set it at all, so
make it available in debugfs.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

To deter future rate scaling algorithm writers from requesting NO_ACK
packets to be retried, throw a WARN_ON_ONCE if the algorithm hands us
a try count over 1 for NO_ACK packet.
Signed-off-by: NGábor Stefanik <netrolller.3d@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

In order to later add tracing or verifications to the driver
calls mac80211 makes, this patch adds static inline wrappers
for all operations.

All calls are now written as

	drv_<op>(local, ...);

instead of

	local->ops-><op>(&local->hw, ...);

Where necessary, the wrappers also do existence checking and
return default values as appropriate.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We currently have two beacon interval configuration knobs:
hw.conf.beacon_int and vif.bss_info.beacon_int. This is
rather confusing, even though the former is used when we
beacon ourselves and the latter when we are associated to
an AP.

This just deprecates the hw.conf.beacon_int setting in favour
of always using vif.bss_info.beacon_int. Since it touches all
the beaconing IBSS code anyway, we can also add support for
the cfg80211 IBSS beacon interval configuration easily.

NOTE: The hw.conf.beacon_int setting is retained for now due
      to drivers still using it -- I couldn't untangle all
      drivers, some are updated in this patch.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The fragmentation threshold is defined to be including the
FCS, and the code that sets the TX_FRAGMENTED flag correctly
accounts for those four bytes. The code that verifies this
doesn't though, which could lead to spurious warnings and
frames being dropped although everything is ok. Correct the
code by accounting for the FCS.

(JWL -- The problem is described here:
 http://article.gmane.org/gmane.linux.kernel.wireless.general/32205 )
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

net/mac80211/tx.c: In function ‘ieee80211_tx_h_select_key’:
net/mac80211/tx.c:448: warning: ‘key’ may be used uninitialized in this function

drivers/net/wireless/ath/ath9k/rc.c: In function ‘ath_rc_rate_getidx’:
drivers/net/wireless/ath/ath9k/rc.c:815: warning: ‘nextindex’ may be used uninitialized in this function

drivers/net/wireless/hostap/hostap_plx.c: In function ‘prism2_plx_probe’:
drivers/net/wireless/hostap/hostap_plx.c:438: warning: ‘cor_index’ may be used uninitialized in this function
drivers/net/wireless/hostap/hostap_plx.c:438: warning: ‘cor_offset’ may be used uninitialized in this function
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Add new nl80211 attributes that can be used with NL80211_CMD_SET_WIPHY
and NL80211_CMD_GET_WIPHY to manage fragmentation/RTS threshold and
retry limits.

Since these values are stored in struct wiphy, remove the local copy
from mac80211 where feasible (frag & rts threshold). The retry limits
are currently needed in struct ieee80211_conf, but these could be
eventually removed since the driver should have access to the values
in struct wiphy.
Signed-off-by: NJouni Malinen <j@w1.fi>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This converts mac80211 to the new cfg80211 IBSS API, the
wext handling functions are called where appropriate.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch sets IEEE80211_TX_CTL_CLEAR_PS_FILT for outgoing
frames for a half-wake station.

this is necessary if one wants to get ps-poll working properly with a p54 ap.
Signed-off-by: NChristian Lamparter <chunkeey@web.de>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch removes all the virtual A-MPDU-queue bookkeeping from
mac80211. Curiously, iwlwifi already does its own bookkeeping, so
it doesn't require much changes except where it needs to handle
starting and stopping the queues in mac80211.

To handle the queue stop/wake properly, we rewrite the software
queue number for aggregation frames and internally to iwlwifi keep
track of the queues that map into the same AC queue, and only talk
to mac80211 about the AC queue. The implementation requires calling
two new functions, iwl_stop_queue and iwl_wake_queue instead of the
mac80211 counterparts.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Cc: Reinette Chattre <reinette.chatre@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Instead of stopping the entire AC queue when enabling aggregation
(which was only done for hardware with aggregation queues) buffer
the packets for each station, and release them to the pending skb
queue once aggregation is turned on successfully.

We get a little more code, but it becomes conceptually simpler and
we can remove the entire virtual queue mechanism from mac80211 in
a follow-up patch.

This changes how mac80211 behaves towards drivers that support
aggregation but have no hardware queues -- those drivers will now
not be handed packets while the aggregation session is being
established, but only after it has been fully established.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We just found a bug in zd1211rw where it would reject
packets in the ->tx() method but leave them modified,
which would cause retransmit attempts with completely
bogus skbs, eventually leading to a panic due to not
having enough headroom in those.

This patch adds a sanity check to mac80211 to catch
such driver mistakes; in this case we warn and drop
the skb.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

__ieee80211_tx takes a struct ieee80211_tx_data argument, but only
uses a few of its members, namely 'skb' and 'sta'. Make that explicit,
so that less internal knowledge is required in ieee80211_tx_pending
and the possibility of introducing errors here is removed.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Reviewed-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The pending packets code is quite incomprehensible, uses memory barriers
nobody really understands, etc. This patch reworks it entirely, using
the queue spinlock, proper stop bits and the skb queues themselves to
indicate whether packets are pending or not (rather than a separate
variable like before).
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Reviewed-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Internally, mac80211 requires the skb's queue mapping to be set
to the AC queue, not the virtual A-MPDU queue. This is not done
correctly currently, this patch moves the code down to directly
before the driver is invoked and adds a comment that it will be
moved into the driver later.

Since this requires __ieee80211_tx() to have the sta pointer,
make sure to provide it in ieee80211_tx_pending().
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Reviewed-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Fragmentation currently uses an allocated array to store the
fragment skbs, and then keeps track of which have been sent
and which are still pending etc. This is rather complicated;
make it simpler by just chaining the fragments into skb->next
and removing from that list when sent. Also simplifies all
code that needs to touch fragments, since it now only needs
to walk the skb->next list.

This is a prerequisite for fixing the stored packet code,
which I need to do for proper aggregation packet storing.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Reviewed-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

ieee80211_tx_h_check_assoc() was dropping everything else than probe
requests during software scan. So the nullfunc frame with the power save
bit was dropped and AP never received it. This meant that AP never
buffered any frames for the station during software scan.

Fix this by allowing to transmit both probe request and nullfunc frames
during software scan. Tested with stlc45xx.
Signed-off-by: NKalle Valo <kalle.valo@nokia.com>
Acked-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This inline is useless and actually makes the code _longer_
rather than shorter.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

It was possible to hit a kernel panic on NULL pointer dereference in
dev_queue_xmit() when sending power save buffered frames to a STA that
woke up from sleep. This happened when the buffered frame was requeued
for transmission in ap_sta_ps_end(). In order to avoid the panic, copy
the skb->dev and skb->iif values from the first fragment to all other
fragments.
Signed-off-by: NJouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch splits out the ibss code and data from managed (station) mode.
The reason to do this is to better separate the state machines, and have
the code be contained better so it gets easier to determine what exactly
a given change will affect, that in turn makes it easier to understand.

This is quite some churn, especially because I split sdata->u.sta into
sdata->u.mgd and sdata->u.ibss, but I think it's easier to maintain that
way. I've also shuffled around some code -- null function sending is only
applicable to managed interfaces so put that into that file, some other
functions are needed from various places so put them into util, and also
rearranged the prototypes in ieee80211_i.h accordingly.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>