There is a race between the TX path and the STA wakeup: while
a station is sleeping, mac80211 buffers frames until it wakes
up, then the frames are transmitted. However, the RX and TX
path are concurrent, so the packet indicating wakeup can be
processed while a packet is being transmitted.
This can lead to a situation where the buffered frames list
is emptied on the one side, while a frame is being added on
the other side, as the station is still seen as sleeping in
the TX path.
As a result, the newly added frame will not be send anytime
soon. It might be sent much later (and out of order) when the
station goes to sleep and wakes up the next time.
Additionally, it can lead to the crash below.
Fix all this by synchronising both paths with a new lock.
Both path are not fastpath since they handle PS situations.
In a later patch we'll remove the extra skb queue locks to
reduce locking overhead.
BUG: unable to handle kernel
NULL pointer dereference at 000000b0
IP: [<ff6f1791>] ieee80211_report_used_skb+0x11/0x3e0 [mac80211]
*pde = 00000000
Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
EIP: 0060:[<ff6f1791>] EFLAGS: 00210282 CPU: 1
EIP is at ieee80211_report_used_skb+0x11/0x3e0 [mac80211]
EAX: e5900da0 EBX: 00000000 ECX: 00000001 EDX: 00000000
ESI: e41d00c0 EDI: e5900da0 EBP: ebe458e4 ESP: ebe458b0
DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
CR0: 8005003b CR2: 000000b0 CR3: 25a78000 CR4: 000407d0
DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
DR6: ffff0ff0 DR7: 00000400
Process iperf (pid: 3934, ti=ebe44000 task=e757c0b0 task.ti=ebe44000)
iwlwifi 0000:02:00.0: I iwl_pcie_enqueue_hcmd Sending command LQ_CMD (#4e), seq: 0x0903, 92 bytes at 3[3]:9
Stack:
e403b32c ebe458c4 00200002 00200286 e403b338 ebe458cc c10960bb e5900da0
ff76a6ec ebe458d8 00000000 e41d00c0 e5900da0 ebe458f0 ff6f1b75 e403b210
ebe4598c ff723dc1 00000000 ff76a6ec e597c978 e403b758 00000002 00000002
Call Trace:
[<ff6f1b75>] ieee80211_free_txskb+0x15/0x20 [mac80211]
[<ff723dc1>] invoke_tx_handlers+0x1661/0x1780 [mac80211]
[<ff7248a5>] ieee80211_tx+0x75/0x100 [mac80211]
[<ff7249bf>] ieee80211_xmit+0x8f/0xc0 [mac80211]
[<ff72550e>] ieee80211_subif_start_xmit+0x4fe/0xe20 [mac80211]
[<c149ef70>] dev_hard_start_xmit+0x450/0x950
[<c14b9aa9>] sch_direct_xmit+0xa9/0x250
[<c14b9c9b>] __qdisc_run+0x4b/0x150
[<c149f732>] dev_queue_xmit+0x2c2/0xca0
Cc: stable@vger.kernel.org
Reported-by: Yaara Rozenblum <yaara.rozenblum@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Reviewed-by: Stanislaw Gruszka <sgruszka@redhat.com>
[reword commit log, use a separate lock]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Teach sta_info_flush() to optionally also remove stations
from all VLANs associated with an AP interface to optimise
the station removal (in particular, synchronize_net().)
To not have to add the vlans argument throughout, do some
refactoring.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
There's no reason to have one synchronize_net() for each
removed station, refactor the code slightly to have just
a single synchronize_net() for all stations.
Note that this is currently useless as hostapd removes
stations one by one and this coalescing never happens.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
If we can assume that stations are never referenced by the
driver after sta_state returns (and this is true since the
previous iwlmvm patch and for all other drivers) then we
don't need to delay station destruction, and don't need to
play tricks with rcu_barrier() etc.
This should speed up some scenarios like hostapd shutdown.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Measure TX latency and jitter statistics per station per TID.
These Measurements are disabled by default and can be enabled
via debugfs.
Features included for each station's TID:
1. Keep count of the maximum and average latency of Tx frames.
2. Keep track of many frames arrived in a specific time range
(need to enable through debugfs and configure the bins ranges)
Signed-off-by: Matti Gottlieb <matti.gottlieb@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Use put_unaligned_le16 in mesh_plink_frame_tx.
Signed-off-by: Chun-Yeow Yeoh <yeohchunyeow@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This adds generic cipher scheme support to mac80211, such schemes
are fully under control by the driver. On hw registration drivers
may specify additional HW ciphers with a scheme how these ciphers
have to be handled by mac80211 TX/RR. A cipher scheme specifies a
cipher suite value, a size of the security header to be added to
or stripped from frames and how the PN is to be verified on RX.
Signed-off-by: Max Stepanov <Max.Stepanov@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
When the driver requests to move to STATIC or DYNAMIC SMPS,
we send an action frame to each associated station and
reconfigure the channel context / driver.
Of course, non-MIMO stations are ignored.
The beacon isn't updated. The association response will
include the original capabilities. Stations that associate
while in non-OFF SMPS mode will get an action frame right
after association to inform them about our current state.
Note that we wait until the end of the EAPOL. Sending an
action frame before the EAPOL is finished can be an issue
for a few clients. Clients aren't likely to send EAPOL
frames in MIMO anyway.
When the SMPS configuration gets more permissive (e.g.
STATIC -> OFF), we don't wake up stations that are asleep
We remember that they don't know about the change and send
the action frame when they wake up.
When the SMPS configuration gets more restrictive (e.g.
OFF -> STATIC), we set the TIM bit for every sleeping STA.
uAPSD stations might send MIMO until they poll the action
frame, but this is for a short period of time.
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
[fix vht streams loop, initialisation]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
All accesses of the tid_start_tx lock should be protected
by sta->lock if there is any chance that another thread
could still be accessing the sta object.
Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Make the TX bytes/packets counters race-free by keeping
them per AC so concurrent TX on queues can't cause lost
or wrong updates. This works since each station belongs
to a single interface. While at it also make the bytes
counters 64-bit.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Remove not used any longer suspend/resume code.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
ieee80211_ht_cap_ie_to_sta_ht_cap() will clean up the
ht_supported flag and station bandwidth field for us
if the peer beacon doesn't have an HT capability element
(is operating as non-HT).
Also, we don't really need a special station ch_width
member to track the station operating mode any more so use
sta.bandwidth instead.
Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Handle the operating mode notification action frame.
When the supported streams or the bandwidth change
let the driver and rate control algorithm know.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
For VHT, many more bandwidth changes are possible. As a first
step, stop toggling the IEEE80211_HT_CAP_SUP_WIDTH_20_40 flag
in the HT capabilities and instead introduce a bandwidth field
indicating the currently usable bandwidth to transmit to the
station. Of course, make all drivers use it.
To achieve this, make ieee80211_ht_cap_ie_to_sta_ht_cap() get
the station as an argument, rather than the new capabilities,
so it can set up the new bandwidth field.
If the station is a VHT station and VHT bandwidth is in use,
also set the bandwidth accordingly.
Doing this allows us to get rid of the supports_40mhz flag as
the HT capabilities now reflect the true capability instead of
the current setting.
While at it, also fix ieee80211_ht_cap_ie_to_sta_ht_cap() to not
ignore HT cap overrides when MCS TX isn't supported (not that it
really happens...)
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Fix most kernel-doc warnings, for some reason it
seems to have issues with __aligned, don't remove
the documentation entries it considers to be in
excess due to that.
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Add routines to
- maintain a PS mode for each peer and a non-peer PS mode
- indicate own PS mode in transmitted frames
- track neighbor STAs power modes
- buffer frames when neighbors are in PS mode
- add TIM and Awake Window IE to beacons
- release frames in Mesh Peer Service Periods
Add local_pm to sta_info to represent the link-specific power
mode at this station towards the remote station. When a peer
link is established, use the default power mode stored in mesh
config. Update the PS status if the peering status of a neighbor
changes.
Maintain a mesh power mode for non-peer mesh STAs. Set the
non-peer power mode to active mode during peering. Authenticated
mesh peering is currently not working when either node is
configured to be in power save mode.
Indicate the current power mode in transmitted frames. Use QoS
Nulls to indicate mesh power mode transitions.
For performance reasons, calls to the function setting the frame
flags are placed in HWMP routing routines, as there the STA
pointer is already available.
Add peer_pm to sta_info to represent the peer's link-specific
power mode towards the local station. Add nonpeer_pm to
represent the peer's power mode towards all non-peer stations.
Track power modes based on received frames.
Add the ps_data structure to ieee80211_if_mesh (for TIM map, PS
neighbor counter and group-addressed frame buffer).
Set WLAN_STA_PS flag for STA in PS mode to use the unicast frame
buffering routines in the tx path. Update num_sta_ps to buffer
and release group-addressed frames after DTIM beacons.
Announce the awake window duration in beacons if in light or
deep sleep mode towards any peer or non-peer. Create a TIM IE
similarly to AP mode and add it to mesh beacons. Parse received
Awake Window IEs and check TIM IEs for buffered frames.
Release frames towards peers in mesh Peer Service Periods. Use
the corresponding trigger frames and monitor the MPSP status.
Append a QoS Null as trigger frame if neccessary to properly end
the MPSP. Currently, in HT channels MPSPs behave imperfectly and
show large delay spikes and frame losses.
Signed-off-by: Marco Porsch <marco@cozybit.com>
Signed-off-by: Ivan Bezyazychnyy <ivan.bezyazychnyy@gmail.com>
Signed-off-by: Mike Krinkin <krinkin.m.u@gmail.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The initiator/tx doesn't really identify why an
aggregation session is stopped, give a reason
for stopping that more clearly identifies what's
going on. This will help tell the driver clearly
what is expected of it.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
If there are VLANs, stopping an AP is inefficient as it
calls rcu_barrier() once for each interface (the VLANs
and the AP itself). Optimise this by moving rcu_barrier()
out of the station cleanups and calling it only once for
all interfaces combined.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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: Ben Greear <greearb@candelatech.com>
Signed-off-by: Johannes 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: Ben Greear <greearb@candelatech.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Unfortunately, commit b22cfcfcae, 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: Ben Greear <greearb@candelatech.com>
Tested-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Johannes 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: Saravana <saravanad@posedge.com>
[fix various whitespace issues, reword commit log]
Signed-off-by: Johannes 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: Saravana <saravanad@posedge.com>
Signed-off-by: Johannes 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: Johannes 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: Johannes 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: Yoni Divinsky <yoni.divinsky@ti.com>
Signed-off-by: Eliad Peller <eliad@wizery.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Add a few kernel-doc descriptions that were missed
during mesh development.
Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Ashok Nagarajan <ashok@cozybit.com>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Add a few kernel-doc descriptions that were missed
during development.
Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Johannes 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: Joe Perches <joe@perches.com>
Signed-off-by: David 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: Ashok Nagarajan <ashok@cozybit.com>
Reviewed-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John 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: Marco Porsch <marco.porsch@s2005.tu-chemnitz.de>
Signed-off-by: Pavel Zubarev <pavel.zubarev@gmail.com>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John 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: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John 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: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John 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: Thomas Pedersen <thomas@cozybit.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John 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: Felix Fietkau <nbd@openwrt.org>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John 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: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John 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: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John 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: Eliad Peller <eliad@wizery.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John 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: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John 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: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
If station info contains a beacon loss count, return
it to userspace.
Signed-off-by: Paul Stewart <pstew@chromium.org>
Signed-off-by: John 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: Nikolay Martynov <mar.kolya@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
No real changes, just note that they are const.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John 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: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John 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: Nikolay Martynov <mar.kolya@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Emmanuel Grumbach
Johannes Berg
Matti Gottlieb
Chun-Yeow Yeoh
Max Stepanov
Ben Greear
Felix Fietkau
Stanislaw Gruszka
Thomas Pedersen
Marco Porsch
Saravana
Eliad Peller
Ashok Nagarajan
David S. Miller
Joe Perches
Javier Cardona
Paul Stewart
Nikolay Martynov
Mohammed Shafi Shajakhan