By default, the rhashtable logic will fail to insert
objects if the key-chains are too long and un-balanced.

In the degenerate case where mac80211 is creating many
virtual interfaces connected to the same peer(s), this
case can happen.

St insecure_elasticity to true to allow chains to grow
as long as needed.
Signed-off-by: Ben Greear <greearb@candelatech.com>
[remove message, change commit message slightly]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

The original hand-implemented hash-table in mac80211 couldn't result
in insertion errors, and while converting to rhashtable I evidently
forgot to check the errors.

This surfaced now only because Ben is adding many identical keys and
that resulted in hidden insertion errors.

Cc: stable@vger.kernel.org
Fixes: 7bedd0cf

 ("mac80211: use rhashtable for station table")
Reported-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

On error we jumped to the error label and returned the error code but we
missed releasing sinfo.

Fixes: 5fe74014172d ("mac80211: avoid excessive stack usage in sta_info")
Reviewed-by: Julian Calaby <julian.calaby@gmail.com>
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
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>

When CONFIG_OPTIMIZE_INLINING is set, the sta_info_insert_finish
function consumes more stack than normally, exceeding the
1024 byte limit on ARM:

net/mac80211/sta_info.c: In function 'sta_info_insert_finish':
net/mac80211/sta_info.c:561:1: error: the frame size of 1080 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]

It turns out that there are two functions that put a 'struct station_info'
on the stack: __sta_info_destroy_part2 and sta_info_insert_finish, and
this structure alone requires up to 792 bytes.

Hoping that both are called rarely enough, this replaces the
on-stack structure with a dynamic allocation, which unfortunately
requires some suboptimal error handling for out-of-memory.

The __sta_info_destroy_part2 function is actually affected by the
stack usage twice because it calls cfg80211_del_sta_sinfo(), which
has another instance of struct station_info on its stack.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 98b62183 ("mac80211/cfg80211: add station events")
Fixes: 6f7a8d26

 ("mac80211: send statistics with delete station event")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

The minimum chandef bandwidth calculation was done only in case
a new station was inserted (or when an existing station was removed).
However, it is possible that stations are inserted before they are
associated, e.g., when FULL_AP_CLIENT_STATE is supported and user
space adds stations unassociated.

Fix this by calling ieee80211_recalc_min_chandef() whenever
a station transitions in/out the associated state, and only
consider station marked as associated.
Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

My commit below broken PS-Poll handling. In case the driver
has no frames buffered, driver_release_tids will be 0, but
calling find_highest_prio_tid() with 0 as a parameter is
not a good idea:
fls(0) - 1 = -1.
This bug caused mac80211 to think that frames were buffered
in the driver which in turn was confused because mac80211
was asking to release frames that were not reported to
exist.
On iwlwifi, this led to the WARNING below:

WARNING: CPU: 0 PID: 11230 at drivers/net/wireless/intel/iwlwifi/mvm/sta.c:1733 iwl_mvm_sta_modify_sleep_tx_count+0x2af/0x320 [iwlmvm]()
ffffffffc0627c60 ffff8800069b7648 ffffffff81888913 0000000000000000
0000000000000000 ffff8800069b7688 ffffffff81089d6a ffff8800069b7678
0000000000000001 ffff88003b35abf0 ffff88000698b128 ffff8800069b76d4
Call Trace:
[<ffffffff81888913>] dump_stack+0x4c/0x65
[<ffffffff81089d6a>] warn_slowpath_common+0x8a/0xc0
[<ffffffff81089e5a>] warn_slowpath_null+0x1a/0x20
[<ffffffffc05f36bf>] iwl_mvm_sta_modify_sleep_tx_count+0x2af/0x320 [iwlmvm]
[<ffffffffc05dae41>] iwl_mvm_mac_release_buffered_frames+0x31/0x40 [iwlmvm]
[<ffffffffc045d8b6>] ieee80211_sta_ps_deliver_response+0x6e6/0xd80 [mac80211]
[<ffffffffc0461296>] ieee80211_sta_ps_deliver_poll_response+0x26/0x30 [mac80211]
[<ffffffffc048f743>] ieee80211_rx_handlers+0xa83/0x2900 [mac80211]
[<ffffffffc04917ad>] ieee80211_prepare_and_rx_handle+0x1ed/0xa70 [mac80211]
[<ffffffffc045e3d5>] ? sta_info_get_bss+0x5/0x4a0 [mac80211]
[<ffffffffc04925b6>] ieee80211_rx_napi+0x586/0xcd0 [mac80211]
[<ffffffffc05eaa3e>] iwl_mvm_rx_rx_mpdu+0x59e/0xc60 [iwlmvm]

Fixes: 0ead2510

 ("mac80211: allow the driver to send EOSP when needed")
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

add ieee80211_iter_keys_rcu() to iterate over uploaded
keys in atomic context (when rcu is locked)

The station removal code removes the keys only after
calling synchronize_net(), so it's not safe to iterate
the keys at this point (and postponing the actual key
deletion with call_rcu() might result in some
badly-ordered ops calls).

Add a flag to indicate a station is being removed,
and skip the configured keys if it's set.
Signed-off-by: Eliad Peller <eliadx.peller@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

This can happen when the driver needs to send less frames
than expected and then needs to close the SP.
Mac80211 still needs to set the more_data properly based
on its buffer state (ps_tx_buffer and buffered frames on
other TIDs).
To that end, refactor the code that delivers frames upon
uAPSD trigger frames to be able to get only the more_data
bit without actually delivering those frames in case the
driver is just asking to set a NDP with EOSP and MORE_DATA
bit properly set.
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Some devices or drivers cannot deal with having the same station
address for different virtual interfaces, say as a client to two
virtual AP interfaces. Rather than requiring each driver with a
limitation like that to enforce it, add a hardware flag for it.
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>

There's little point in keeping (and even sending to userspace)
the beacon_loss_count value per station, since it can only apply
to the AP on a managed-mode connection. Move the value to ifmgd,
advertise it only in managed mode, and remove it from ethtool as
it's available through better interfaces.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

There's only a single caller of this function, so it can
be moved to the same file and made static.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

The mac80211 code uses ktime_get_ts to measure the connected time.
As this uses monotonic time, it is y2038 safe on 32-bit systems,
but we still want to deprecate the use of 'timespec' because most
other users are broken.

This changes the code to use ktime_get_seconds() instead, which
avoids the timespec structure and is slightly more efficient.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: linux-wireless@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>

Instead of using the out-of-line average calculation, use the new
DECLARE_EWMA() macro to declare a signal EWMA, and use that.

This actually *reduces* the code size slightly (on x86-64) while
also reducing the station info size by 80 bytes.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

According to 802.11-2012 13.3.1, a mesh STA should assign an AID
upon receipt of a mesh peering open frame rather than using the link
id of the peer.  Using the peer link id has two potential issues:
it may not be unique among the peers, and by its nature it is random,
so the TIM may not compress well.

In preparation for allocating it properly, use sta->sta.aid, but keep
the existing behavior of using the plid in the aid we send.
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

There are now a fairly large number of mesh fields that really
aren't needed in any other modes; move those into their own
structure and allocate them separately.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Currently, the station hash table lookup (or iteration) must
access two cachelines for each station - the one with the hash
table node, and the one with the MAC address.

Duplicate the MAC address next to the hash node to get rid of
this. Since the MAC address is static there's no consistency
problem introduced by this.
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 hashtable behaviour change was merged into the tree
at about the same time as the mac80211 use of rhashtable,
but of course these don't really conflict in the normal
sense. Enable hash table shrinking now.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Allow debug builds to configure the station hash table maximum
size in order to run with hash collisions in limited scenarios
such as hwsim testing. The default remains 0 which effectively
means no limit.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

My conversion of the mac80211 station hash table to rhashtable
completely broke the lookup in sta_info_get() as it no longer
took into account the virtual interface. Fix that.

Fixes: 7bedd0cf

 ("mac80211: use rhashtable for station table")
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>

Both minstrel (reported by Sven Eckelmann) and the iwlwifi rate
control aren't properly taking concurrency into account. It's
likely that the same is true for other rate control algorithms.

In the case of minstrel this manifests itself in crashes when an
update and other data access are run concurrently, for example
when the stations change bandwidth or similar. In iwlwifi, this
can cause firmware crashes.

Since fixing all rate control algorithms will be very difficult,
just provide locking for invocations. This protects the internal
data structures the algorithms maintain.

I've manipulated hostapd to test this, by having it change its
advertised bandwidth roughly ever 150ms. At the same time, I'm
running a flood ping between the client and the AP, which causes
this race of update vs. get_rate/status to easily happen on the
client. With this change, the system survives this test.
Reported-by: Sven Eckelmann <sven@open-mesh.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

The mesh plink code uses sta->lock to serialize access to the
plink state fields between the peer link state machine and the
peer link timer.  Some paths (e.g. those involving
mps_qos_null_tx()) unfortunately hold this spinlock across
frame tx, which is soon to be disallowed.  Add a new spinlock
just for plink access.
Signed-off-by: Bob Copeland <me@bobcopeland.com>
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>

We currently have a hand-rolled table with 256 entries and are
using the last byte of the MAC address as the hash. This hash
is obviously very fast, but collisions are easily created and
we waste a lot of space in the common case of just connecting
as a client to an AP where we just have a single station. The
other common case of an AP is also suboptimal due to the size
of the hash table and the ease of causing collisions.

Convert all of this to use rhashtable with jhash, which gives
us the advantage of a far better hash function (with random
perturbation to avoid hash collision attacks) and of course
that the hash table grows and shrinks dynamically with chain
length, improving both cases above.

Use a specialised hash function (using jhash, but with fixed
length) to achieve better compiler optimisation as suggested
by Sergey Ryazanov.
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>

Revert commit ad38bfc9

 ("mac80211: Tx frame latency statistics")
(along with some follow-up fixes).

This code turned out not to be as useful in the current form as we
thought, and we've internally hacked it up more, but that's not
very suitable for upstream (for now), and we might just do that
with tracing instead.

Therefore, for now at least, remove this code. We might also need
to use the skb->tstamp field for the TCP performance issue, which
is more important than the debugging.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

For drivers without beacon filtering, support beacon statistics
entirely, i.e. report the number of beacons and average signal.

For drivers with beacon filtering, give them the number of beacons
received by mac80211 -- in case the device reports only the number
of filtered beacons then driver doesn't have to count all beacons
again as mac80211 already does.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

When a station disconnects with frames still pending, we clear
the TIM bit, but too late - it's only cleared when the station
is already removed from the driver, and thus the driver can get
confused (and hwsim will loudly complain.)

Fix this by clearing the TIM bit earlier, when the station has
been unlinked but not removed from the driver yet. To do this,
refactor the TIM recalculation to in that case ignore traffic
and simply assume no pending traffic - this is correct for the
disconnected station even though the frames haven't been freed
yet at that point.

This patch isn't needed for current drivers though as they don't
check the station argument to the set_tim() operation and thus
don't really run into the possible confusion.
Reported-by: Jouni Malinen <j@w1.fi>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Implement the new counters cfg80211 can now advertise to userspace.
The TX code is in the sequence number handler, which is a bit odd,
but that place already knows the TID and frame type, so it was
easiest and least impact there.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

This is really just duplicating the list of information that's
already available in the nl80211 attribute, so remove the list.
Two small changes are needed:
 * remove STATION_INFO_ASSOC_REQ_IES complete, but the length
   (assoc_req_ies_len) can be used instead
 * add NL80211_STA_INFO_RX_DROP_MISC which exists internally
   but not in nl80211 yet

This gets rid of the duplicate maintenance of the two lists.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

In many cases, drivers can filter things like beacons that will
skew statistics reported by mac80211. To get correct statistics
in these cases, call drivers to obtain statistics and let them
override all values, filling values from mac80211 if the driver
didn't provide them. Not all of them make sense for the driver
to fill, so some are still always done by mac80211.

Note that this doesn't currently allow a driver to say "I know
this value is wrong, don't report it at all", or to sum it up
with a mac80211 value (as could be useful for "dropped misc"),
that can be added if it turns out to be needed.

This also gets rid of the get_rssi() method as is can now be
implemented using sta_statistics().
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Use the new cfg80211_del_sta_sinfo() function to send the
statistics about the deleted station with the delete event.
This lets userspace see how much traffic etc. the deleted
station used.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Move IEEE80211_TX_CTL_PS_RESPONSE to info->control.flags since
this is used only in the TX path (by ath9k). This frees up
a bit which can be used for other purposes.
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

In TDLS (e.g., TDLS off-channel) there is a requirement for
some drivers to supply an unused TID between the AP and the
device to the FW, to allow sending PTI requests and to allow
the FW to aggregate on a specific TID for better throughput.

To ensure that the allocated TID is indeed unused, this patch
introduces an API for blocking the driver from TXing on that
TID.
Signed-off-by: Liad Kaufman <liad.kaufman@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Implement the cfg80211 TDLS channel switch ops and introduce new mac80211
ones for low-level drivers.
Verify low-level driver support for the new ops when using the relevant
wiphy feature bit. Also verify the peer supports channel switching before
passing the command down.

Add a new STA flag to track the off-channel state with the TDLS peer and
make sure to cancel the channel-switch if the peer STA is unexpectedly
removed.
Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Instead of passing the band as a parameter to ieee80211_xmit()
and ieee80211_tx(), move it outside of the two functions while
making sure info->band is set up before calling them.

This removes the parameter and simplifies the follow commit.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Deliver up to 128 frames during service period instead of 8 if
unlimited is specified by the client during association.
8 was just an arbitrary value; so is 128 since unlimited can
be any number.

However for large traffic bursts, increasing this value looks
reasonable. Also, it seems that a few certification tests
expect more frames to be delivered during SP.
Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>