Since we enqueued the frame that was supposed to be sent
during the SP, and that frame may very well cary the
IEEE80211_TX_STATUS_EOSP bit, we may never close the SP
(WLAN_STA_SP will never be cleared). If that happens, we
will not open any new SP and will never respond to any poll
frame from the client.
Clear WLAN_STA_SP manually if a frame that was polled during
the SP is queued because of a starting A-MPDU session. The
client may not see the EOSP bit, but it will at least be
able to poll new frames in another SP.
Reported-by: Alesya Shapira <alesya.shapira@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
[remove erroneous comment]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Frames that are sent between
ampdu_action(IEEE80211_AMPDU_TX_START) and the move to the
HT_AGG_STATE_OPERATIONAL state are buffered.
If we try to start an A-MPDU session while the peer is
sleeping and polling frames with U-APSD, we may have frames
that will be buffered by ieee80211_tx_prep_agg. These frames
have IEEE80211_TX_CTL_NO_PS_BUFFER set since they are sent to
a sleeping client and possibly IEEE80211_TX_STATUS_EOSP.
If the frame is buffered, we need clear these two flags
since they will be re-sent after the move to
HT_AGG_STATE_OPERATIONAL state which is very likely to
happen after the SP ends.
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Buffered multicast frames must be passed to the driver directly via
drv_tx instead of going through the txq, otherwise they cannot easily be
scheduled to be sent after DTIM.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Since offset is zero, it's not necessary to use set function. Reset
function is straightforward, and will remove the unnecessary add
operation in set function.
Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix wiphy supported_band access in tx radiotap parsing introduced
in commit 5ec3aed9ba4c ("mac80211: Parse legacy and HT rate in
injected frames"). In particular, info->band is always set to 0
(IEEE80211_BAND_2GHZ) since it has not assigned yet.
This cause a kernel crash on 5GHz only devices.
Move ieee80211_parse_tx_radiotap() after info->band assignment
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Remember the last time when a mpp table entry is used for
rx or tx and remove them after MESH_PATH_EXPIRE time.
Acked-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Henning Rogge <henning.rogge@fkie.fraunhofer.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

This will allow drivers to make more educated
decisions whether to defer transmission or not.

Relying on wake_tx_queue() call count implicitly
was not possible because it could be called
without queued frame count actually changing on
software tx aggregation start/stop code paths.

It was also not possible to know how long
byte-wise queue was without dequeueing.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Drivers/devices without their own rate control algorithm can get the
information what rates they should use from either the radiotap header of
injected frames or from the rate control algorithm. But the parsing of the
legacy rate information from the radiotap header was removed in commit
e6a9854b

 ("mac80211/drivers: rewrite the rate control API").

The removal of this feature heavily reduced the usefulness of frame
injection when wanting to simulate specific transmission behavior. Having
rate parsing together with MCS rates and retry support allows a fine
grained selection of the tx behavior of injected frames for these kind of
tests.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Cc: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

We need to free all skbs here, not just the one we peeked
from the list.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Group station statistics by where they're (mostly) updated
(TX, RX and TX-status) and group them into sub-structs of
the struct sta_info.

Also rename the variables since the grouping now makes it
obvious where they belong.

This makes it easier to identify where the statistics are
updated in the code, and thus easier to think about them.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

When using software queueing, tx sequence number assignment happens at
ieee80211_tx_dequeue time, so the fast-xmit codepath must not do that.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

When debugging wireless powersave issues on the AP side it's quite helpful
to see our own beacons that are transmitted by the hardware/driver. However,
this is not that easy since beacons don't pass through the regular TX queues.

Preferably drivers would call ieee80211_tx_status also for tx'ed beacons
but that's not always possible. Hence, just send a copy of each beacon
generated by ieee80211_beacon_get_tim to monitor devices when they are
getting fetched by the driver.

Also add a HW flag IEEE80211_HW_BEACON_TX_STATUS that can be used by
drivers to indicate that they report TX status for beacons.
Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
(with a fix from Christian Lamparted rolled in)
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Fixes dropped packets in the tx path in case a non-PS station triggers
the tx filter.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

To make mac80211 accept the multicast rate requested by the user the
rate control should be told that it is operating in BSS mode.
Without this, the default rate is selected in rate_control_send_low
(!pubsta and !txrc->bss)
Signed-off-by: Bertold Van den Bergh <bertold.vandenbergh@esat.kuleuven.be>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

If an SKB will be segmented by the driver, count it for multiple
MSDUs that are being transmitted rather than just a single.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

We already set a station to be associated when peering completes, both
in user space and in the kernel.  Thus we should always have an
associated sta before sending data frames to that station.

Failure to check assoc state can cause crashes in the lower-level driver
due to transmitting unicast data frames before driver sta structures
(e.g. ampdu state in ath9k) are initialized.  This occurred when
forwarding in the presence of fixed mesh paths: frames were transmitted
to stations with whom we hadn't yet completed peering.

Cc: stable@vger.kernel.org
Reported-by: Alexis Green <agreen@cococorp.com>
Tested-by: Jesse Jones <jjones@cococorp.com>
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

The beacon struct is already available in many contexts that
are also already in an RCU read-locked section. Avoid that by
using the existing beacon struct pointer directly.
Signed-off-by: Wojciech Dubowik <Wojciech.Dubowik@neratec.com>
[rewrite subject/add commit message]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

This counter is inherently racy (since it can be incremented by RX
as well as by concurrent TX) and only available in debugfs. Instead
of fixing it to be per-CPU or similar, remove it for now. If needed
it should be added without races and with proper nl80211, perhaps
even addressing the threshold reporting TODO item that's been there
since the code was originally added.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

When acting as AP and a PS-Poll frame is received
associated station is marked as one in a Service
Period. This state is kept until Tx status for
released frame is reported. While a station is in
Service Period PS-Poll frames are ignored.

However if PS-Poll was received during A-MPDU
teardown it was possible to have the to-be
released frame re-queued back to pending queue.
In such case the frame was stripped of 2 important
flags:

 (a) IEEE80211_TX_CTL_NO_PS_BUFFER
 (b) IEEE80211_TX_STATUS_EOSP

Stripping of (a) led to the frame that was to be
released to be queued back to ps_tx_buf queue. If
station remained to use only PS-Poll frames the
re-queued frame (and new ones) was never actually
transmitted because mac80211 would ignore
subsequent PS-Poll frames due to station being in
Service Period. There was nothing left to clear
the Service Period bit (no xmit -> no tx status ->
no SP end), i.e. the AP would have the station
stuck in Service Period. Beacon TIM would
repeatedly prompt station to poll for frames but
it would get none.

Once (a) is not stripped (b) becomes important
because it's the main condition to clear the
Service Period bit of the station when Tx status
for the released frame is reported back.

This problem was observed with ath9k acting as P2P
GO in some testing scenarios but isn't limited to
it. AP operation with mac80211 based Tx A-MPDU
control combined with clients using PS-Poll frames
is subject to this race.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

As we're running out of hardware capability flags pretty quickly,
convert them to use the regular test_bit() style unsigned long
bitmaps.

This introduces a number of helper functions/macros to set and to
test the bits, along with new debugfs code.

The occurrences of an explicit __clear_bit() are intentional, the
drivers were never supposed to change their supported bits on the
fly. We should investigate changing this to be a per-frame flag.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

The conversion to the fast-xmit path lost proper aggregation session
timeout handling - the last_tx wasn't set on that path and the timer
would therefore incorrectly tear down the session periodically (with
those drivers/rate control algorithms that have a timeout.)

In case of iwlwifi, this was every 5 seconds and caused significant
throughput degradation.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

For drivers supporting TSO or similar features, but that still have
PN assignment in software, there's a need to have some memory to
store the current PN value. As mac80211 already stores this and it's
somewhat complicated to add a per-driver area to the key struct (due
to the dynamic sizing thereof) it makes sense to just move the TX PN
to the keyconf, i.e. the public part of the key struct.

As TKIP is more complicated and we won't able to offload it in this
way right now (fast-xmit is skipped for TKIP unless the HW does it
all, and our hardware needs MMIC calculation in software) I've not
moved that for now - it's possible but requires exposing a lot of
the internal TKIP state.

As an bonus side effect, we can remove a lot of code by assuming the
keyseq struct has a certain layout - with BUILD_BUG_ON to verify it.

This might also improve performance, since now TX and RX no longer
share a cacheline.
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

No current (and planned, as far as I know) wifi devices support
encapsulation checksum offload, so remove the useless test here.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

This counter is unsafe with concurrent TX and is only exposed
through debugfs and ethtool. Instead of trying to fix it just
remove it for now, if it's really needed then it should be
exposed through nl80211 and in a way that drivers that do the
fragmentation in the device could support it as well.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

This isn't all that relevant for RX right now, but TX can be concurrent
due to multi-queue and the accounting is therefore broken.

Use the standard per-CPU statistics to avoid this.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

This isn't necessary any more as the stack will automatically
update the TXQ's trans_start after calling ndo_start_xmit().
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Implement the necessary software segmentation on the normal
TX path so that fast-xmit can use segmentation offload if
the hardware (or driver) supports it.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

If drivers want to support S/G (really just gather DMA on TX) then
we can now easily support this on the fast-xmit path since it just
needs to write to the ethernet header (and already has a check for
that being possible.)

However, disallow this on the regular TX path (which has to handle
fragmentation, software crypto, etc.) by calling skb_linearize().

Also allow the related HIGHDMA since that's not interesting to the
code in mac80211 at all anyway.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

When we go through the complete TX processing, there are a number
of things like fragmentation and software crypto that require the
checksum to be calculated already.

In favour of maintainability, instead of adding the necessary call
to skb_checksum_help() in all the places that need it, just do it
once before the regular TX processing.

Right now this only affects the TI wlcore and QCA ath10k drivers
since they're the only ones using checksum offload. The previous
commits enabled fast-xmit for them in almost all cases.

For wlcore this even fixes a corner case: when a key fails to be
programmed to hardware software encryption gets used, encrypting
frames with a bad checksum.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

IBSS can be supported very easily since it uses the standard station
authorization state etc. so it just needs to be covered by the header
building switch statement.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

When crypto is offloaded then in some cases it's all handled
by the device, and in others only some space for the IV must
be reserved in the frame. Handle both of these cases in the
fast-xmit path, up to a limit of 18 bytes of space for IVs.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

If the driver handles fragmentation then it wouldn't
be done in software so we can still use the fast-xmit
path in that case.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

In order to speed up mac80211's TX path, add the "fast-xmit" cache
that will cache the data frame 802.11 header and other data to be
able to build the frame more quickly. This cache is rebuilt when
external triggers imply changes, but a lot of the checks done per
packet today are simplified away to the check for the cache.

There's also a more detailed description in the code.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

This allows drivers to request per-vif and per-sta-tid queues from which
they can pull frames. This makes it easier to keep the hardware queues
short, and to improve fairness between clients and vifs.

The task of scheduling packet transmission is left up to the driver -
queueing is controlled by mac80211. Drivers can only dequeue packets by
calling ieee80211_tx_dequeue. This makes it possible to add active queue
management later without changing drivers using this code.

This can also be used as a starting point to implement A-MSDU
aggregation in a way that does not add artificially induced latency.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
[resolved minor context conflict, minor changes, endian annotations]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

In order to look up the RA station earlier to implement a TX
fastpath, factor out the lookup from ieee80211_build_hdr().
To always have a valid station pointer, also move some of the
checks into the new function.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Indicating just the peer's capability is fairly pointless
if the local device doesn't support it. Make the variable
track both combined, and remove the 'local support' check
in the TX path.
Signed-off-by: Johannes 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: Johannes Berg <johannes.berg@intel.com>

In ieee80211_build_hdr(), the station is looked up to build the
header correctly (QoS field) and to check for authorization. For
mesh, authorization isn't checked here, and QoS capability is
mandatory, so the station lookup can be avoided.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

If there's no station on the 4-addr VLAN interface, then frames
cannot be transmitted. Drop such frames earlier, before setting
up all the information for them.

We should keep the old check though since that code might be used
for other internally-generated frames.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

There's no need to look up the destination station twice while
building the 802.11 header for a given frame if the frame will
actually be transmitted to the station we initially looked up.

This happens for 4-addr VLAN interfaces and TDLS connections, which
both directly send the frame to the station they looked up, though
in the case of TDLS some station conditions need to be checked.

To avoid that, add a variable indicating that we've looked up the
station that the frame is going to be transmitted to, and avoid the
lookup/flag checking if it already has been done.

In the TDLS case, also move the authorized/wme_sta flag assignment
to the correct place, i.e. only when that station is really used.
Before this change, the new lookup should always have succeeded so
that the potentially erroneous data would be overwritten.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>