Declaring the factor is counter-intuitive, and people are prone
to using small(-ish) values even when that makes no sense.

Change the DECLARE_EWMA() macro to take the fractional precision,
in bits, rather than a factor, and update all users.

While at it, add some more documentation.
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When RX aggregation starts, transmitter may continue send frames
with SN smaller than SSN until the AddBA response is received.
However, the reorder buffer is already initialized at this point,
which will cause the drop of such frames as duplicates since the
head SN of the reorder buffer is set to the SSN, which is bigger.

Cc: stable@vger.kernel.org
Signed-off-by: NSara Sharon <sara.sharon@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

On drivers setting the SUPPORTS_REORDERING_BUFFER hardware flag,
we crash when the peer sends an AddBA request while we already
have a session open on the seame TID; this is because on those
drivers, the tid_agg_rx is left NULL even though the session is
valid, and the agg_session_valid bit is set.

To fix this, store the dialog tokens outside the tid_agg_rx to
be able to compare them to the received AddBA request.

Fixes: f89e07d4 ("mac80211: agg-rx: refuse ADDBA Request with timeout update")
Reported-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

mac80211 currently uses rhashtable with insecure_elasticity set
to true.  The latter is because of duplicate objects.  What's
more, mac80211 walks the rhashtable chains by hand which is broken
as rhashtable may contain multiple tables due to resizing or
rehashing.

This patch fixes it by converting it to the newly added rhltable
interface which is designed for use with duplicate objects.

With rhltable a lookup returns a list of objects instead of a
single one.  This is then fed into the existing for_each_sta_info
macro.

This patch also deletes the sta_addr_hash function since rhashtable
defaults to jhash.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When we receive data frames with ACK policy BlockAck, send
delBA as requested by the 802.11 spec. Since this would be
happening for every frame inside an A-MPDU if it's really
received outside a session, limit it to a single attempt.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Mesh HWMP module will be able to rely on the HW
RC algorithm if it exists, for path metric calculations.

This allows the metric calculation mechanism to calculate
a correct metric, based on PER and last TX rate both via
HW RC algorithm if it exists or via parameters collected
by the SW.
Signed-off-by: NMaxim Altshul <maxim.altshul@ti.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The header field is defined as u8[] but also accessed as struct
ieee80211_hdr. Enforce an alignment of 2 to prevent unnecessary
unaligned accesses, which can be very harmful for performance on many
platforms.

Fixes: e495c247 ("mac80211: extend fast-xmit for more ciphers")
Cc: stable@vger.kernel.org
Signed-off-by: NFelix Fietkau <nbd@nbd.name>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

If the driver advertises the new HW flag USE_RSS, make the
station statistics on the fast-rx path per-CPU. This will
enable calling the RX in parallel, only hitting locking or
shared cachelines when the fast-RX path isn't available.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The regular RX path has a lot of code, but with a few
assumptions on the hardware it's possible to reduce the
amount of code significantly. Currently the assumptions
on the driver are the following:
 * hardware/driver reordering buffer (if supporting aggregation)
 * hardware/driver decryption & PN checking (if using encryption)
 * hardware/driver did de-duplication
 * hardware/driver did A-MSDU deaggregation
 * AP_LINK_PS is used (in AP mode)
 * no client powersave handling in mac80211 (in client mode)

of which some are actually checked per packet:
 * de-duplication
 * PN checking
 * decryption
and additionally packets must
 * not be A-MSDU (have been deaggregated by driver/device)
 * be data packets
 * not be fragmented
 * be unicast
 * have RFC 1042 header

Additionally dynamically we assume:
 * no encryption or CCMP/GCMP, TKIP/WEP/other not allowed
 * station must be authorized
 * 4-addr format not enabled

Some data needed for the RX path is cached in a new per-station
"fast_rx" structure, so that we only need to look at this and
the packet, no other memory when processing packets on the fast
RX path.

After doing the above per-packet checks, the data path collapses
down to a pretty simple conversion function taking advantage of
the data cached in the small fast_rx struct.

This should speed up the RX processing, and will make it easier
to reason about parallelizing RX (for which statistics will need
to be per-CPU still.)
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

On 32-bit platforms, the 64-bit counters we keep need to be protected
to be consistently read. Use the u64_stats_sync mechanism to do that.

In order to not end up with overly long lines, refactor the tidstats
assignments a bit.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When storing the last_rate_* values in the RX code, there's nothing
to guarantee consistency, so a concurrent reader could see, e.g.
last_rate_idx on the new value, but last_rate_flag still on the old,
getting completely bogus values in the end.

To fix this, I lifted the sta_stats_encode_rate() function from my
old rate statistics code, which encodes the entire rate data into a
single 16-bit value, avoiding the consistency issue.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Instead of touching the rx_stats.last_rx from the status path, introduce
and use a status_stats.last_ack variable. This will make rx_stats.last_rx
indicate when the last frame was received, making it available for real
"last_rx" and statistics gathering; statistics, when done per-CPU, will
need to figure out which place was updated last for those items where the
"last" value is exposed.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Move the averaged values out of rx_stats and into rx_stats_avg,
to cleanly split them out. The averaged ones cannot be supported
for parallel RX in a per-CPU fashion, while the other values can
be collected per CPU and then combined/selected when needed.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Avoid the really strange %s%s%s expression, use an array
of flag names and check that all flags are present.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Since the previous patch, the struct only has a single member,
so remove the struct and leave just the single member.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Remove unused variable in per STA debugfs structure, 'commit 34e89507
("mac80211: allow station add/remove to sleep")' removed the only user of
'add_has_run'.
Signed-off-by: NMohammed Shafi Shajakhan <mohammed@qti.qualcomm.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Commit 976bd9ef ("mac80211: move beacon_loss_count into ifmgd")
removed the member from the sta_info struct but the description stayed
lingering. Remove it.
Signed-off-by: NLuis de Bethencourt <luisbg@osg.samsung.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

If any frames are dropped that are part of a BA session, the reorder
buffer will "indefinitely" (until the timeout) wait for them to come
in (or a BAR moving the window) and won't release frames after them.
This means it isn't possible to filter frames within a BA session in
firmware.

Introduce an API function that allows such filtering. Calling this
function will move the BA window forward to the new SSN, and allows
marking frames after the SSN as having been filtered, so any future
reordering activity will release frames while skipping the holes.
Signed-off-by: NSara Sharon <sara.sharon@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Enable driver to manage the reordering logic itself.
This is needed for example for the iwlwifi driver that
will support hardware assisted reordering.
Signed-off-by: NSara Sharon <sara.sharon@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes 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: NEliad Peller <eliadx.peller@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes 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: NJohannes 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: NJohannes Berg <johannes.berg@intel.com>

This file only feeds a debugfs file that isn't very useful, so remove
it. If necessary, we can add other ways to get this information, for
example in the NL80211_CMD_PROBE_CLIENT response.
Signed-off-by: NJohannes 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: NJohannes Berg <johannes.berg@intel.com>

Advertise the capability to send A-MSDU within A-MPDU
in the AddBA request sent by mac80211. Let the driver
know about the peer's capabilities.
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

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: NJohannes 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: NBob Copeland <me@bobcopeland.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This value is only used in mesh, so move it into the new mesh
sub-struct of the station info.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Define a station chandef, to be used for wider-bw TDLS peers. When both
peers support the feature, upgrade the channel bandwidth to the maximum
allowed by both peers and regulatory. Currently widths up to 80MHz are
supported in the 5GHz band.

When a TDLS peer connects/disconnects recalculate the channel type of the
current chanctx.
Make the chanctx width calculation consider wider-bw TDLS peers and
similarly fix the max_required_bw calculation for the chanctx min_def.
Since the sta->bandwidth is calculated only later on, take
bss_conf.chandef.width as the minimal width for station interface.

Set the upgraded channel width in the VHT-operation set during TDLS setup.
Signed-off-by: NArik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Allow a device to specify support for the TDLS wider-bandwidth feature.
Indicate this support during TDLS setup in the ext-capab IE and set an
appropriate station flag when our TDLS peer supports it.
This feature gives TDLS peers the ability to use a wider channel than
the base width of the BSS. For instance VHT capable TDLS peers connected
on a 20MHz channel can extend the channel to 80MHz, if regulatory
considerations allow it.

Do not cap the bandwidth of such stations by the current BSS channel width
in mac80211.
Signed-off-by: NArik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes 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: NJohannes 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: NJohannes Berg <johannes.berg@intel.com>

There are no RX queues in mac80211 (yet), the comment should refer
to the TID (including one slot for non-QoS) rather than 'RX queue'.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This struct member is only assigned, never used otherwise;
remove it.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

In mesh mode there is a race between establishing links and processing
rates and capabilities in beacons. This is very noticeable with slow
beacons (e.g. beacon intervals of 1s) and manifested for us as stations
using minstrel when minstrel_ht should be used. Fixed by changing
mesh_sta_info_init so that it always checks rates and such if it has not
already done so.
Signed-off-by: NAlexis Green <agreen@cococorp.com>
CC: Jesse Jones <jjones@cococorp.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This was missed in the previous patch, add some documentation
for rate_ctrl_lock to avoid docbook warnings.
Signed-off-by: NJohannes 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: NJohannes 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: NJohannes 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: NJohannes 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: NSven Eckelmann <sven@open-mesh.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>