The call to ieee80211_hw_config() is supposed to apply changes
synchronously, so once it returns the parameters are applied to
the hardware. Thus, there really is no need to delay the probing
by the channel switch time again since the channel switch has
already happened once we get to this code.
Additionally, there is no need to wait for a NAV update (probe
delay) when the channel is passively scanned. Remove that extra
time too.
This cuts scanning time from over 7 seconds to under 4 on ar9170,
which is due to the number of channels scanned and ar9170's switch
time being advertised as 135ms (my test now indicates it is about
77ms with the current driver, but the difference might also be due
to using a different machine with different USB controllers).
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When management frame protection (IEEE 802.11w) is used, unprotected
Robust Action frames are not allowed prior to key configuration.
However, unprotected Deauthentication and Disassociation frames are
allowed at that point, but not after key configuration.
Make ieee80211_drop_unencrypted() handle the special cases for MFP by
separating the basic Data frame case from Management frame processing
and handle the Management frames only if MFP has been negotiated. In
addition, do not use sdata->drop_unencrypted for Management frames
since the decision on whether to accept the frame depends on the key
being configured.
Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When using nl80211, we do not have a mechanism to set
sdata->drop_unencrypted. Currently, this breaks code that is supposed
to drop unencrypted frames when protection is expected since
ieee80211_rx_h_decrypt() is optimized to not set rx->key when the
frame is not protected.
This patch modifies ieee80211_rx_h_decrypt() to set rx->key for all
frames and only skip decryption if the frame is not protected. This
allows ieee80211_drop_unencrypted() to correctly drop frames even if
drop_unencrypted is not set.
The changes here are not enough to handle all cases, though. Additional
patches will be needed to implement proper IEEE 802.1X PAE for station
mode (currently, this is only used for AP mode) and some additional
rules are needed for MFP to drop unprotected Robust Action frames prior
to having PTK and IGTK configured.
In theory, the unprotected frames could and should be dropped in
ieee80211_rx_h_decrypt(). However, due to the special case with EAPOL
frames that have to be allowed to be received unprotected even when
keys are set, it is simpler to only set rx->key and allow the
ieee80211_frame_allowed() function to handle the actual dropping of
data frames after 802.11->802.3 header conversion. In addition,
unprotected robust management frames are dropped before they are
processed.
Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
We've never really cared about the default QoS (WMM) values, but
we really should if the AP doesn't send any. This patch makes
mac80211 use the default values according to 802.11-2007, and
additionally syncs the default values when we disassociate so
whatever the last AP said gets "unconfigured".
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When a software scan starts, it first sets sw_scanning, but
leaves the scan_channel "unset" (it currently actually gets
initialised to a default). Now, when something else tries
to (re)configure the hardware in the window between these two
events (after sw_scanning = true, but before scan_channel is
set), the current code switches to the (unset!) scan_channel.
This causes trouble, especially when switching bands and
sending frames on the wrong channel.
To work around this, leave scan_channel initialised to NULL
and use it to determine whether or not a switch to a different
channel should occur (and also use the same condition to check
whether to adjust power for scan or not).
Additionally, avoid reconfiguring the hardware completely when
recalculating idle resulted in no changes, this was the problem
that originally led us to discover the race condition in the
first place, which was helpfully bisected by Pavel. This part
of the patch should not be necessary with the other fixes, but
not calling the ieee80211_hw_config function when we know it to
be unnecessary is certainly a correct thing to do.
Unfortunately, this patch cannot and does not fix the race
condition completely, but due to the way the scan code is
structured it makes the particular problem Pavel discovered
(race while changing channel at the same time as transmitting
frames) go away. To fix it completely, more work especially
with locking configuration is needed.
Bisected-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
NL80211_CMD_ASSOCIATE request must be able to indicate whether
management frame protection (IEEE 802.11w) is being used. mac80211 was
able to use MFP in client mode only with WEXT, but the new
NL80211_ATTR_USE_MFP attribute will allow this to be done with
nl80211, too.
Since we are currently using nl80211 for MFP only with drivers that
use user space SME, only MFP disabled and required values are
used. However, the NL80211_ATTR_USE_MFP attribute is an enum that can
be extended with MFP optional in the future, if that is needed with
some drivers (e.g., if the RSN IE is generated by the driver).
Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
We are currently processing block ack reordering as a separate task
before all other RX handlers. In theory, this is wrong since this step
should be done only after duplicate removal (see Figure 6-1 in IEEE
802.11n). However, moving this needs some work and the current
situation is not too bad. Add a comment here so that this small detail
does not get forgotten and who knows, maybe someone has some extra
time to take a look at cleaning this up.
Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This patch allows skbs to be released from the RX reorder buffer in
case they have been there for an unexpectedly long time without us
having received the missing frames before them. Previously, these
frames were only released when the reorder window moved and that could
take very long time unless new frames were received constantly (e.g.,
TCP connections could be killed more or less indefinitely).
This situation should not happen very frequently, but it looks like
there are some scenarious that trigger it for some reason. As such,
this should be considered mostly a workaround to speed up recovery
from unexpected siutation that could result in connections hanging for
long periods of time.
The changes here will only check for timeout situation when adding new
RX frames to the reorder buffer. It does not handle all possible
cases, but seems to help for most cases that could result from common
network usage (e.g., TCP retrying at least couple of times). For more
completely coverage, a timer could be used to periodically check
whether there are any frames remaining in the reorder buffer if no new
frames are received.
Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
No need to duplicate the same code in two places (and that would be
three after the followup patch).
Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
net/mac80211/mlme.c:2079:28: warning: symbol 'ssid_len' shadows an earlier one
net/mac80211/mlme.c:2022:12: originally declared here
ssid_len is already being declared and checked above so there is
no need for it again.
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
It's not very helpful to see, in iwconfig, the current frequency
the card is tuned to if that frequency is currently somewhere
across the board because we're scanning. Since we keep track of
the frequency the user wants, display that instead.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When we aren't doing anything in mac80211, we can turn off
much of the hardware, depending on the driver/hw. Not doing
anything, aka being idle, means:
* no monitor interfaces
* no AP/mesh/wds interfaces
* any station interfaces are in DISABLED state
* any IBSS interfaces aren't trying to be in a network
* we aren't trying to scan
By creating a new function that verifies these conditions and calling
it at strategic points where the states of those conditions change,
we can easily make mac80211 tell the driver when we are idle to save
power.
Additionally, this fixes a small quirk where a recalculated powersave
state is passed to the driver even if the hardware is about to stopped
completely.
This patch intentionally doesn't touch radio_enabled because that is
currently implemented to be a soft rfkill which is inappropriate here
when we need to be able to wake up with low latency.
One thing I'm not entirely sure about is this:
phy0: device no longer idle - in use
wlan0: direct probe to AP 00:11:24:91:07:4d try 1
wlan0 direct probe responded
wlan0: authenticate with AP 00:11:24:91:07:4d
wlan0: authenticated
> phy0: device now idle
> phy0: device no longer idle - in use
wlan0: associate with AP 00:11:24:91:07:4d
wlan0: RX AssocResp from 00:11:24:91:07:4d (capab=0x401 status=0 aid=1)
wlan0: associated
Is it appropriate to go into idle state for a short time when we have
just authenticated, but not associated yet? This happens only with the
userspace SME, because we cannot really know how long it will wait
before asking us to associate. Would going idle after a short timeout
be more appropriate? We may need to revisit this, depending on what
happens.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John 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: Gábor Stefanik <netrolller.3d@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Make PID check for IEEE80211_TX_CTL_NO_ACK instead of
is_multicast_ether_addr when determining whether to use the lowest
rate, and set the retry count to 0 (total try count = 1) if
IEEE80211_TX_CTL_NO_ACK is set.
Signed-off-by: Gábor Stefanik <netrolller.3d@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Make the retry count zero (total try count = 1) for frames with
IEEE80211_TX_CTL_NO_ACK set.
Also remove the check for is_multicast_ether_addr in use_low_rate,
which is redundant because all multicasts have IEEE80211_TX_CTL_NO_ACK
set.
Signed-off-by: Gábor Stefanik <netrolller.3d@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Due to the use of a _REQ_DIRECT_PROBE bit, which is
unnecessary (and I wonder why it was done that way),
an interesting situation can arise:
1) we try to probe an access point
2) the AP doesn't response in time
3) we tell userspace that we gave up
4) the AP suddenly responds
5) we auth/assoc with the AP
I've seen 4) happen in testing with hostapd SIGSTOPped,
and when SIGCONTinued it processes the probe requests
that came in and send responses. But 5) is not supposed
to happen after we tell everybody we've given up on the
AP.
To fix this, remove the _REQ_DIRECT_PROBE request bit,
and process probe responses when we're in the relevant
MLME state, namely IEEE80211_STA_MLME_DIRECT_PROBE.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
If the direct probe times out, we need to send the authentication
timeout event to notify SME in the same way as we notify on timeout
with authentication frames since the direct probe is run as part of
the authentication attempt.
Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John 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: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The config_interface method is a little strange, it contains the
BSSID and beacon updates, while bss_info_changed contains most
other BSS information for each interface. This patch removes
config_interface and rolls all the information it previously
passed to drivers into bss_info_changed.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John 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: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
There are some places marked
/* XXX maybe racy? */
and they really are racy because there's no locking.
This patch reworks much of the scan code, and introduces proper
locking for the scan request as well as the internal scanning
(which is necessary for IBSS/managed modes). Helper functions
are added to call the scanning code whenever necessary. The
scan deferring is changed to simply queue the scanning work
instead of trying to start the scan in place, the scanning work
will then take care of the rest.
Also, currently when internal scans are requested for an interface
that is trying to associate, we reject such scans. This was not
intended, the mlme code has provisions to scan twice when it can't
find the BSS to associate with right away; this has never worked
properly. Fix this by not rejecting internal scan requests for an
interface that is associating.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When the IBSS code wants to scan, but that fails, we can
get stuck in a situation where you can never scan again.
Fix this by properly notifying ourselves when the scan
request has failed.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Kalle points out that max_sleep_interval is somewhat confusing
because the value is measured in beacon intervals, and not in
TU. Rename it to max_sleep_period to be consistent with things
like DTIM period that are also measured in beacon intervals.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When somebody changes the PS parameters while scanning
is in progress, we enable PS -- during the scan. This
is clearly not desirable, and we can just abort enabling
PS when scanning since when the scan finishes it will
be taken care of.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Reviewed-by: Kalle Valo <kalle.valo@iki.fi>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
There are a few problems in the IBSS code:
a) it tries to activate interfaces that are down after scanning
b) it crashes after scanning on an IBSS iface that isn't active
c) since the ssid_len is used as a flag, need to make it visible
only after all other settings are set, this helps protect
against b)
For b), we get a system crash:
wlan0: Creating new IBSS network, BSSID ce:f9:88:76:1e:4d
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<...>] ieee80211_sta_find_ibss+0x294/0x37d [mac80211]
Call Trace:
[<...>] ieee80211_ibss_notify_scan_completed+0x0/0x88 [mac80211]
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
pid doesn't count with some band having more bitrates than the one
associated the first time.
Fix that by counting the maximal available bitrate count and allocate
big enough space.
Secondly, fix touching uninitialized memory which causes panics.
Index sucked from this random memory points to the hell.
The fix is to sort the rates on each band change.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
minstrel doesn't count max rate count in fact, since it doesn't use
a loop variable `i' and hence allocs space only for bitrates found in
the first band.
Fix it by involving the `i' as an index so that it traverses all the
bands now and finds the real max bitrate count.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John 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: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
In "mac80211: correct wext transmit power handler"
I fixed the wext handler, but forgot to make the default of the
user_power_level -1 (aka "auto"), so that now the transmit power
is always set to 0, causing associations to time out and similar
problems since we're transmitting with very little power. Correct
this by correcting the default user_power_level to -1.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Bisected-by: Niel Lambrechts <niel.lambrechts@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
- ieee80211_wep_init(), which is called with rtnl_lock held, blocks in
request_module() [waiting for modprobe to load a crypto module].
- modprobe blocks in a call to flush_workqueue(), when it closes a TTY
[presumably when it exits].
- The workqueue item linkwatch_event() blocks on rtnl_lock.
There's no reason for wep_init() to be called with rtnl_lock held, so
just move it outside the critical section.
Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: John 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: John W. Linville <linville@tuxdriver.com>
SME needs to be notified when the authentication or association
attempt times out and MLME has stopped processing in order to allow
the SME to decide what to do next.
Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The maximum sleep interval, for powersave purposes, is
determined by the DTIM period (it may not be larger)
and the required networking latency (it must be small
enough to fulfil those constraints).
This makes mac80211 calculate the maximum sleep interval
based on those constraints, and pass it to the driver.
Then the driver should instruct the device to sleep at
most that long.
Note that the device is responsible for aligning the
maximum sleep interval between DTIMs, we make sure it's
not longer but it needs to make sure it's between them.
Also, group some powersave documentation together and
make it more explicit that we support managed mode only,
and no IBSS powersaving (yet).
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Just setting IEEE80211_CONF_CHANGE_PS should be sufficient
for changes in the power saving things. The driver already
tells us whether it wants notification of dynps via the
"have dynps support" hw flag.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Reviewed-by: Kalle Valo <kalle.valo@iki.fi>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Stephen Rothwell reported these warnings from a 32-bit build:
net/mac80211/mlme.c:1771: warning: left shift count >= width of type
net/mac80211/mlme.c:1772: warning: left shift count >= width of type
net/mac80211/mlme.c:1773: warning: left shift count >= width of type
net/mac80211/mlme.c:1774: warning: left shift count >= width of type
net/mac80211/mlme.c:1775: warning: left shift count >= width of type
This shows a bug in my code -- BIT(X) uses just "1 << X" which means
a 32-bit integer on 32-bit platforms, but the code here needs a u64
on all platforms. Fix this by using "1ULL << X" instead of BIT(X).
Thanks Stephen!
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
With the RCU locking here we sleep while in an atomic context,
since we can sleep just use mutex locking for the interface
list instead of RCU. Sorry, seems I didn't get that in my UML
test.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The TIM IE must not be shorter than 4 bytes, so verify that
when parsing it and use the proper type. To ease that adjust
struct ieee80211_tim_ie to have a virtual bitmap of size
at least 1.
Also check that the TIM IE is actually present before trying
to parse it!
Because other people may need the function, make it a static
inline in ieee80211.h.
(The original "mac80211: validate TIM IE length" was a minimal fix for
2.6.30. This purports to be the full, correct fix. -- JWL)
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John 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: Jouni Malinen <j@w1.fi>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Trying to separate header files into net/wireless.h and
net/cfg80211.h has been a source of confusion. Remove
net/wireless.h (because there also is the linux/wireless.h)
and subsume everything into net/cfg80211.h -- except the
definitions for regulatory structures which get moved to
a new header net/regulatory.h.
The "new" net/cfg80211.h is now divided into sections.
There are no real changes in this patch but code shuffling
and some very minor documentation fixes.
I have also, to make things reflect reality, put in a
copyright line for Luis to net/regulatory.h since that
is probably exclusively written by him but was formerly
in a file that only had my copyright line.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John 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: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Since we have ->deauth and ->disassoc we can support the
wext SIWMLME call directly without driver wext handlers.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John 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: Christian Lamparter <chunkeey@web.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
We can allow scan requests in AP mode as long as the interface has not
yet been configured to send out Beacon frames (or if beaconing has
been disabled prior to the scan request). This makes it easier to scan
for neighboring BSSes during AP initialization and makes it possible
to run a scan without setting the interface down, if needed. Without
this change, the only available option would be to set the interface
down, move into station mode, and set the interface up, prior to
requesting the scan.
Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Enable PS by default (depending on Kconfig) -- rely on drivers
to control the level using pm_qos. Due to the previous patch
we turn off PS when necessary due to latency requirements.
This has a Kconfig symbol so people can, if they really want,
configure the default in their kernels. We may want to keep it
at "default y" only in wireless-testing for a while.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Regardless of whether the hardware implements beacon filtering,
there's no need to process all beacons in software all the time
throughout the stack (mac80211 does a lot, then cfg80211, then
in the future possibly userspace).
This patch implements the "best possible" beacon filtering in
mac80211. "Best possible" means that it can look for changes in
all requested information elements, and distinguish vendor IEs
by their OUI.
In the future, we will add nl80211 API for userspace to request
information elements and vendor IE OUIs to watch -- drivers can
then implement the best they can do while software implements
it fully.
It is unclear whether or not this actually saves CPU time, but
the data is all in the cache already so it should be fairly
cheap. The additional _testing_, however, has great benefit;
Without this, and on hardware that doesn't implement beacon
filtering, wrong assumptions about, for example, scan result
updates could quickly creep into code.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When an application asks for a latency lower than the beacon interval
there's nothing we can do -- we need to stay awake and not have the
AP buffer frames for us. Add code to automatically calculate this
constraint in mac80211 so drivers need not concern themselves with it.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
