Currently beacon loss detection triggers after a scan. A probe request
is sent and a message like this is printed to the log:

wlan0: beacon loss from AP 00:12:17:e7:98:de - sending probe request

But in fact there is no beacon loss, the beacons are just not received
because of the ongoing scan. Fix it by updating last_beacon after
the scan has finished.
Reported-by: NJaswinder Singh Rajput <jaswinder@kernel.org>
Signed-off-by: NKalle Valo <kalle.valo@iki.fi>
Acked-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The TIM IE must not be shorter than 4 bytes, so verify that
when parsing it.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Using the scan_sdata variable here is terribly wrong,
if there has never been a scan then we fail. However,
we need a bandaid...
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Cc: stable@kernel.org [2.6.29]
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

On Sunday 05 April 2009 11:29:38 Michael Buesch wrote:
> On Sunday 05 April 2009 11:23:59 Jaswinder Singh Rajput wrote:
> > With latest linus tree I am getting, .config file attached:
> >
> > [   22.895051] r8169: eth0: link down
> > [   22.897564] ADDRCONF(NETDEV_UP): eth0: link is not ready
> > [   22.928047] ADDRCONF(NETDEV_UP): wlan0: link is not ready
> > [   22.982292] libvirtd used greatest stack depth: 4200 bytes left
> > [   63.709879] wlan0: authenticate with AP 00:11:95:9e:df:f6
> > [   63.712096] wlan0: authenticated
> > [   63.712127] wlan0: associate with AP 00:11:95:9e:df:f6
> > [   63.726831] wlan0: RX AssocResp from 00:11:95:9e:df:f6 (capab=0x471 status=0 aid=1)
> > [   63.726855] wlan0: associated
> > [   63.730093] ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
> > [   74.296087] wlan0: no IPv6 routers present
> > [   79.349044] wlan0: beacon loss from AP 00:11:95:9e:df:f6 - sending probe request
> > [  119.358200] wlan0: beacon loss from AP 00:11:95:9e:df:f6 - sending probe request
> > [  179.354292] wlan0: beacon loss from AP 00:11:95:9e:df:f6 - sending probe request
> > [  259.366044] wlan0: beacon loss from AP 00:11:95:9e:df:f6 - sending probe request
> > [  359.348292] wlan0: beacon loss from AP 00:11:95:9e:df:f6 - sending probe request
> > [  361.953459] packagekitd used greatest stack depth: 4160 bytes left
> > [  478.824258] wlan0: beacon loss from AP 00:11:95:9e:df:f6 - sending probe request
> > [  598.813343] wlan0: beacon loss from AP 00:11:95:9e:df:f6 - sending probe request
> > [  718.817292] wlan0: beacon loss from AP 00:11:95:9e:df:f6 - sending probe request
> > [  838.824567] wlan0: beacon loss from AP 00:11:95:9e:df:f6 - sending probe request
> > [  958.815402] wlan0: beacon loss from AP 00:11:95:9e:df:f6 - sending probe request
> > [ 1078.848434] wlan0: beacon loss from AP 00:11:95:9e:df:f6 - sending probe request
> > [ 1198.822913] wlan0: beacon loss from AP 00:11:95:9e:df:f6 - sending probe request
> > [ 1318.824931] wlan0: beacon loss from AP 00:11:95:9e:df:f6 - sending probe request
> > [ 1438.814157] wlan0: beacon loss from AP 00:11:95:9e:df:f6 - sending probe request
> > [ 1558.827336] wlan0: beacon loss from AP 00:11:95:9e:df:f6 - sending probe request
> > [ 1678.823011] wlan0: beacon loss from AP 00:11:95:9e:df:f6 - sending probe request
> > [ 1798.830589] wlan0: beacon loss from AP 00:11:95:9e:df:f6 - sending probe request
> > [ 1918.828044] wlan0: beacon loss from AP 00:11:95:9e:df:f6 - sending probe request
> > [ 2038.827224] wlan0: beacon loss from AP 00:11:95:9e:df:f6 - sending probe request
> > [ 2116.517152] wlan0: beacon loss from AP 00:11:95:9e:df:f6 - sending probe request
> > [ 2158.840243] wlan0: beacon loss from AP 00:11:95:9e:df:f6 - sending probe request
> > [ 2278.827427] wlan0: beacon loss from AP 00:11:95:9e:df:f6 - sending probe request
>
>
> I think this message should only show if CONFIG_MAC80211_VERBOSE_DEBUG is set.
> It's kind of expected that we lose a beacon once in a while, so we shouldn't print
> verbose messages to the kernel log (even if they are KERN_DEBUG).
>
> And besides that, I think one can easily remotely trigger this message and flood the logs.
> So it should probably _also_ be ratelimited.

Something like this:
Signed-off-by: NMichael Buesch <mb@bu3sch.de>

Add IEEE80211_HW_BEACON_FILTERING flag so that driver inform that it supports
beacon filtering. Drivers need to call the new function
ieee80211_beacon_loss() to notify about beacon loss.
Signed-off-by: NKalle Valo <kalle.valo@nokia.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Separate beacon and rx path tracking in preparation for the beacon filtering
support. At the same time change ieee80211_associated() to look a bit simpler.

Probe requests are now sent only after IEEE80211_PROBE_IDLE_TIME, which
is now set to 60 seconds.
Signed-off-by: NKalle Valo <kalle.valo@nokia.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Currently the timer is triggering every two seconds
(IEEE80211_MONITORING_INTERVAL). Decrease the timer to only trigger during
data idle periods to avoid waking up CPU unnecessary. The timer will
still trigger during idle periods, that needs to be fixed later.

There's also a functional change that probe requests are sent only when the
data path is idle, earlier they were sent also while there was activity
on the data path.

This is also preparation for the beacon filtering support. Thanks to
Johannes Berg for the idea.
Signed-off-by: NKalle Valo <kalle.valo@nokia.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Neither can currently be set from userspace, so there's no
regression potential, and neither will be supported from
userspace since the new userspace APIs allow the SME, which
is in userspace, to control all we need.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The functionality that NL80211_CMD_SET_MGMT_EXTRA_IE provided can now
be achieved with cleaner design by adding IE(s) into
NL80211_CMD_TRIGGER_SCAN, NL80211_CMD_AUTHENTICATE,
NL80211_CMD_ASSOCIATE, NL80211_CMD_DEAUTHENTICATE, and
NL80211_CMD_DISASSOCIATE.

Since this is a very recently added command and there are no known (or
known planned) applications using NL80211_CMD_SET_MGMT_EXTRA_IE and
taken into account how much extra complexity it adds to the IE
processing we have now (and need to add in the future to fix IE order
in couple of frames), it looks like the best option is to just remove
the implementation of this command for now. The enum values themselves
are left to avoid changing the nl80211 command or attribute numbers.
Signed-off-by: NJouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch adds new nl80211 commands to allow user space to request
authentication and association (and also deauthentication and
disassociation). The commands are structured to allow separate
authentication and association steps, i.e., the interface between
kernel and user space is similar to the MLME SAP interface in IEEE
802.11 standard and an user space application takes the role of the
SME.

The patch introduces MLME-AUTHENTICATE.request,
MLME-{,RE}ASSOCIATE.request, MLME-DEAUTHENTICATE.request, and
MLME-DISASSOCIATE.request primitives. The authentication and
association commands request the actual operations in two steps
(assuming the driver supports this; if not, separate authentication
step is skipped; this could end up being a separate "connect"
command).

The initial implementation for mac80211 uses the current
net/mac80211/mlme.c for actual sending and processing of management
frames and the new nl80211 commands will just stop the current state
machine from moving automatically from authentication to association.
Future cleanup may move more of the MLME operations into cfg80211.

The goal of this design is to provide more control of authentication and
association process to user space without having to move the full MLME
implementation. This should be enough to allow IEEE 802.11r FT protocol
and 802.11s SAE authentication to be implemented. Obviously, this will
also bring the extra benefit of not having to use WEXT for association
requests with mac80211. An example implementation of a user space SME
using the new nl80211 commands is available for wpa_supplicant.

This patch is enough to get IEEE 802.11r FT protocol working with
over-the-air mechanism (over-the-DS will need additional MLME
primitives for handling the FT Action frames).
Signed-off-by: NJouni Malinen <j@w1.fi>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Add new nl80211 event notifications (and a new multicast group, "mlme")
for informing user space about received and processed Authentication,
(Re)Association Response, Deauthentication, and Disassociation frames in
station and IBSS modes (i.e., MLME SAP interface primitives
MLME-AUTHENTICATE.confirm, MLME-ASSOCIATE.confirm,
MLME-REASSOCIATE.confirm, MLME-DEAUTHENTICATE.indicate, and
MLME-DISASSOCIATE.indication). The event data is encapsulated as the 802.11
management frame since we already have the frame in that format and it
includes all the needed information.

This is the initial step in providing MLME SAP interface for
authentication and association with nl80211. In other words, kernel code
will act as the MLME and a user space application can control it as the
SME.
Signed-off-by: NJouni Malinen <j@w1.fi>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We must not clear the previous BSSID when roaming to another AP within
the same ESS for reassociation to be used properly. It is fine to
clear this when the SSID changes, so let's move the code into
ieee80211_sta_set_ssid().
Signed-off-by: NJouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NJouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

If a scan is queued in STA mode while the interface is in state direct
probe, authenticate or associate the scan is delayed until the interface
enters disabled or associated state. But in case of direct probe-,
authentication- or association- timeout sta_work will not be scheduled
anymore (without external trigger) and thus the pending scan is not
executed and prevents a new scan from being triggered (-EBUSY).

Fix this by queueing the sta work again after direct probe-, authentication-
and association- timeout.
Signed-off-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This inline is useless and actually makes the code _longer_
rather than shorter.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

If cfg80211 requests a scan it awaits either a return code != 0 from
the scan function or the cfg80211_scan_done to be called. In case of
a STA mac80211's scan function ever returns 0 and queues the scan request.
If ieee80211_sta_work is executed and ieee80211_start_scan fails for
some reason cfg80211_scan_done will never be called but cfg80211 still
thinks the scan was triggered successfully and will refuse any future
scan requests due to drv->scan_req not being cleaned up.

If a scan is triggered from within the MLME a similar problem appears. If
ieee80211_start_scan returns an error, local->scan_req will not be reset
and mac80211 will refuse any future scan requests.

Hence, in both cases call ieee80211_scan_failed (which notifies cfg80211
and resets local->scan_req) if ieee80211_start_scan returns an error.
Signed-off-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Incorrect local->wmm_acm bits were set for AC_BK and AC_BE. Fix this
and add some comments to make it easier to understand the AC-to-UP(pair)
mapping. Set the wmm_acm bits (and show WMM debug) even if the driver
does not implement conf_tx() handler.

In addition, fix the ACM-based AC downgrade code to not use the
highest priority in error cases. We need to break the loop to get the
correct AC_BK value (3) instead of returning 0 (which would indicate
AC_VO). The comment here was not really very useful either, so let's
provide somewhat more helpful description of the situation.

Since it is very unlikely that the ACM flag would be set for AC_BK and
AC_BE, these bugs are not likely to be seen in real life networks.
Anyway, better do these things correctly should someone really use
silly AP configuration (and to pass some functionality tests, too).

Remove the TODO comment about handling ACM. Downgrading AC is
perfectly valid mechanism for ACM. Eventually, we may add support for
WMM-AC and send a request for a TS, but anyway, that functionality
won't be here at the location of this TODO comment.
Signed-off-by: NJouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

If the AP thinks we are in power save state eventhough we are not truly
in that state, it sets the TIM bit and does not send a data frame unless
we send a null data frame to correct the state in the AP.
This might happen if the null data frame for wake up is lost in the air
after we disable power save.
Signed-off-by: NVivek Natarajan <vnatarajan@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

There is no need to parse the AP's HT capabilities if
the STA uses TKIP/WEP cipher. This allows the rate control
module to choose the correct(legacy) rate table.
Signed-off-by: NSujith <Sujith.Manoharan@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch introduces a generic commit() function which initiate a
new network joining process. It should be called after some interface
config changes, so that the changes get applied more cleanly. Currently
set_ssid() and set_bssid() call it. Others can be added in future
patches.

In version 1 the header files was forgotten, sorry.
Signed-off-by: NAlina Friedrichsen <x-alina@gmx.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This extends the NL80211_CMD_TRIGGER_SCAN command to allow applications
to specify a set of information element(s) to be added into Probe
Request frames with NL80211_ATTR_IE. This provides support for the
MLME-SCAN.request primitive parameter VendorSpecificInfo and can be
used, e.g., to implement WPS scanning.
Signed-off-by: NJouni Malinen <jouni.malinen@atheros.com>
Acked-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch splits out the ibss code and data from managed (station) mode.
The reason to do this is to better separate the state machines, and have
the code be contained better so it gets easier to determine what exactly
a given change will affect, that in turn makes it easier to understand.

This is quite some churn, especially because I split sdata->u.sta into
sdata->u.mgd and sdata->u.ibss, but I think it's easier to maintain that
way. I've also shuffled around some code -- null function sending is only
applicable to managed interfaces so put that into that file, some other
functions are needed from various places so put them into util, and also
rearranged the prototypes in ieee80211_i.h accordingly.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

It is possible that some broken AP might send HT IEs in it's
assoc response even though the STA has not sent them in assoc req
when WEP/TKIP is used as pairwise cipher suite. Also it is important
to check this bit before enabling ht mode in beacon receive path.
Signed-off-by: NVasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

It appears that you can completely mess up mac80211 in IBSS
mode by sending it a disassoc or deauth: it'll stop queues
and do a lot more but not ever do anything again. Fix this
by not handling all those frames in IBSS mode,
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The code beyond this point is supposed to be used for
non-IBSS (managed) mode only.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Cc: Jouni Malinen <j@w1.fi>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Remove all the code from mac80211 to keep track of BSSes
and use the cfg80211-provided code completely.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

There's no need to create a BSS struct only to pass it to
ieee80211_sta_join_ibss, so refactor this function into
__ieee80211_sta_join_ibss which takes all the relevant
paramters, and ieee80211_sta_join_ibss which takes a BSS
struct (used when joining an IBSS that already has other
members).
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch adds basic scan capability to cfg80211/nl80211 and
changes mac80211 to use it. The BSS list that cfg80211 maintains
is made driver-accessible with a private area in each BSS struct,
but mac80211 doesn't yet use it. That's another large project.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The sta_info pointer can very well be passed to
ieee80211_sta_tear_down_BA_sessions, this will
later allow us to pass it through even further.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When a directed tim bit is set, mac80211 currently disables power save
ands sends a null frame to the AP. But if dynamic power save is
disabled, mac80211 will not enable power save ever gain. Fix this by
adding ps-poll functionality to mac80211. When a directed tim bit is
set, mac80211 sends a ps-poll frame to the AP and checks for the more
data bit in the returned data frames.

Using ps-poll is slower than waking up with null frame, but it's saves more
power in cases where the traffic is low. Userspace can control if either
ps-poll or null wakeup method is used by enabling and disabling dynamic
power save.
Signed-off-by: NKalle Valo <kalle.valo@nokia.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Currently mac80211 checks for the multicast tim bit from beacons,
disables power save and sends a null frame if the bit is set. This was
added to support ath9k. But this is a bit controversial because the AP will
send multicast frames immediately after the beacon and the time constraints
are really high. Relying mac80211 to be fast enough here might not be
reliable in all situations. And there's no need to send a null frame, AP
will send the frames immediately after the dtim beacon no matter what.

Also if dynamic power save is disabled (iwconfig wlan0 power timeout 0)
currently mac80211 disables power save whenever the multicast bit is set
but it's never enabled again after receiving the first multicast/broadcast
frame.

The current implementation is not usable on p54/stlc45xx and the
easiest way to fix this is to remove the multicast tim bit check
altogether. Handling multicast tim bit in host is rare, most of the
designs do this in firmware/hardware, so it's better not to have it in
mac80211. It's a lot better to do this in firmware/hardware, or if
that's not possible it could be done in the driver.

Also renamed the function to ieee80211_check_tim() to follow the style
of the file.
Signed-off-by: NKalle Valo <kalle.valo@nokia.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NVasanthakumar Thiagarajan <vasanth@atheros.com>
Acked-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

There is no point having the bss information of currently associated AP
when the AP is detected to be out of range.
Signed-off-by: NVasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

I hold back this patch for around a week to avoid
confusion. This is the second step of
"mac80211: Fixed BSSID handling revisited".

With it, in the situation of a strange merge to the
same BSSID (e.g. caused by a TSF overflow) only
reset_tsf() is called.

And sta_info_flush_delayed() is only called if you
change the network manually, not on an automatic
BSSID merge.
Signed-off-by: NAlina Friedrichsen <x-alina@gmx.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This fixes a bug when creating a new IBSS network with a
fixed BSSID. The fixed BSSID situation is now with one of
my last patches handled in ieee80211_sta_find_ibss()
function.

It's more robust to test against
(ifsta->flags & IEEE80211_STA_PREV_BSSID_SET), because
ifsta->state is not seted right in every situation and so
the creating of the new IBSS network sometimes hangs after
the first try to scan for a network to merge.
Signed-off-by: NAlina Friedrichsen <x-alina@gmx.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Trying to associate with a non-existent SSID stops the
state machine after the first run. Subsequent association
requests fail to start the scan engine. Fix this by resetting
assoc_scan_tries to zero after completing a scan run.
Signed-off-by: NSujith <Sujith.Manoharan@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch cleanup the fixed BSSID handling, that
ieee80211_sta_set_bssid() works like ieee80211_sta_set_ssid(). So
that the BSSID is only a second selection criterion besides the
SSID. This allows us to create new IBSS networks with fixed BSSIDs,
which was broken before.

In the second version of this patch the handling of the stupid merges
to the same BSSID is moved out to get reworked into an other patch.

And this version hopefully solves the problems with some low-level
drivers and re-adds the config BSSID warning to help debugging the
low-level drivers.

Much thanks to all who have helped testing! :)
Signed-off-by: NAlina Friedrichsen <x-alina@gmx.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch adds a flag to notify drivers to start and stop
beaconing when needed, for example, during a scan run. Based
on Sujith's first patch to do the same, but now disables
beaconing for all virtual interfaces while scanning, has a
separate change flag and tracks user-space requests.
Signed-off-by: NSujith <Sujith.Manoharan@atheros.com>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Since the standards only define 12 legacy rates, 32 is certainly
a sane upper limit and we don't need to use u64 everywhere. Add
sanity checking that no more than 32 rates are registered and
change the variables to u32 throughout.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The separate Association Comeback Time IE was removed from IEEE 802.11w
and the Timeout Interval IE (from IEEE 802.11r) is used instead. The
editing on this is still somewhat incomplete in IEEE 802.11w/D7.0, but
still, the use of Timeout Interval IE is the expected mechanism.
Signed-off-by: NJouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>