linux-toradex.git/net/wireless/scan.c, branch v3.0.3

cfg80211: fix deadlock with rfkill/sched_scan by adding new mutex

2011-07-05T18:42:36+00:00

There was a deadlock when rfkill-blocking a wireless interface,
because we were locking the rdev mutex on NETDEV_GOING_DOWN to stop
sched_scans that were eventually running.  The rfkill block code was
already holding a mutex under rdev:

kernel: =======================================================
kernel: [ INFO: possible circular locking dependency detected ]
kernel: 3.0.0-rc1-00049-g1fa7b6a #57
kernel: -------------------------------------------------------
kernel: kworker/0:1/4525 is trying to acquire lock:
kernel: (&rdev->mtx){+.+.+.}, at: [] cfg80211_netdev_notifier_call+0x131/0x5b0
kernel:
kernel: but task is already holding lock:
kernel: (&rdev->devlist_mtx){+.+.+.}, at: [] cfg80211_rfkill_set_block+0x4f/0xa0
kernel:
kernel: which lock already depends on the new lock.

To fix this, add a new mutex specifically for sched_scan, to protect
the sched_scan_req element in the rdev struct, instead of using the
global rdev mutex.

Reported-by: Duane Griffin 
Signed-off-by: Luciano Coelho 
Signed-off-by: John W. Linville

cfg80211: don't drop p2p probe responses

2011-06-01T18:34:01+00:00

Commit 0a35d36 ("cfg80211: Use capability info to detect mesh beacons")
assumed that probe response with both ESS and IBSS bits cleared
means that the frame was sent by a mesh sta.

However, these capabilities are also being used in the p2p_find phase,
and the mesh-validation broke it.

Rename the WLAN_CAPABILITY_IS_MBSS macro, and verify that mesh ies
exist before assuming this frame was sent by a mesh sta.

Signed-off-by: Eliad Peller 
Signed-off-by: John W. Linville

cfg80211/mac80211: avoid bounce back mac->cfg->mac on sched_scan_stopped

2011-05-12T18:10:55+00:00

When sched_scan_stopped was called by the driver, mac80211 calls
cfg80211, which in turn was calling mac80211 back with a flag
"driver_initiated".  This flag was used so that mac80211 would do the
necessary cleanup but would not call the driver.  This was enough to
prevent the bounce back between the driver and mac80211, but not
between mac80211 and cfg80211.

To fix this, we now do the cleanup in mac80211 before calling
cfg80211.  To help with locking issues, the workqueue was moved from
cfg80211 to mac80211.

Reported-by: Johannes Berg 
Signed-off-by: Luciano Coelho 
Signed-off-by: John W. Linville

cfg80211/nl80211: add support for scheduled scans

2011-05-11T19:12:26+00:00

Implement new functionality for scheduled scan offload.  With this feature we
can scan automatically at certain intervals.

The idea is that the hardware can perform scan automatically and filter on
desired results without waking up the host unnecessarily.

Add NL80211_CMD_START_SCHED_SCAN and NL80211_CMD_STOP_SCHED_SCAN
commands to the nl80211 interface.  When results are available they are
reported by NL80211_CMD_SCHED_SCAN_RESULTS events.  The userspace is
informed when the scheduled scan has stopped with a
NL80211_CMD_SCHED_SCAN_STOPPED event, which can be triggered either by
the driver or by a call to NL80211_CMD_STOP_SCHED_SCAN.

Signed-off-by: Luciano Coelho 
Signed-off-by: John W. Linville

cfg80211: Use capability info to detect mesh beacons.

2011-05-11T18:37:48+00:00

Mesh beacons no longer use all-zeroes BSSID.  Beacon frames for MBSS,
infrastructure BSS, or IBSS are differentiated by the Capability
Information field in the Beacon frame.  A mesh STA sets the ESS and IBSS
subfields to 0 in transmitted Beacon or Probe Response management
frames.

Signed-off-by: Javier Cardona 
Signed-off-by: John W. Linville

cfg80211: fix BSS double-unlinking (continued)

2011-03-28T19:42:02+00:00

This patch adds to the fix "fix BSS double-unlinking"
(commit 3207390a8b58bfc1335750f91cf6783c48ca19ca) by Johannes Berg.

It turns out, that the double-unlinking scenario can also occur if expired
BSS elements are removed whilst an interface is performing association.

To work around that, replace list_del with list_del_init also in the
"cfg80211_bss_expire" function, so that the check for whether the BSS still is
in the list works correctly in cfg80211_unlink_bss.

Signed-off-by: Juuso Oikarinen 
Reviewed-by: Johannes Berg 
Signed-off-by: John W. Linville

cfg80211:: fix possible NULL pointer dereference

2011-03-28T19:42:02+00:00

In cfg80211_inform_bss_frame() wiphy is first dereferenced on privsz
initialisation and then it is checked for NULL. This patch fixes that.

Signed-off-by: Mariusz Kozlowski 
Acked-by: Johannes Berg 
Signed-off-by: John W. Linville

cfg80211: update information elements in cached BSS struct

2010-12-13T20:23:28+00:00

When a cached BSS struct is updated because a new beacon was received,
the code replaces the cached information elements by the IEs from the
new beacon. However it did not update the pub.information_elements
and pub.len_information_elements fields leaving them either pointing
to the old beacon IEs or in an inconsistent state where the data is
replaced by the new beacon IEs but len_information_elements still has
its value from the first beacon.

Fix this by updating the information elements fields if they are
pointing to beacon IEs.

Signed-off-by: Sven Neumann 
Reviewed-by: Johannes Berg 
Signed-off-by: John W. Linville

cfg80211: fix BSS double-unlinking

2010-10-06T20:30:43+00:00

When multiple interfaces are actively trying
to associate with the same BSS, they may both
find that the BSS isn't there and then try to
unlink it. This can cause errors since the
unlinking code can't currently deal with items
that have already been unlinked.

Normally this doesn't happen as most people
don't try to use multiple station interfaces
that associate at the same time too.

Fix this by using the list entry as a flag to
see if the item is still on a list.

Cc: stable@kernel.org
Reported-by: Ben Greear 
Tested-by: Hun-Kyi Wynn 
Signed-off-by: Johannes Berg 
Signed-off-by: John W. Linville

cfg80211: don't get expired BSSes

2010-07-14T17:52:45+00:00

When kernel-internal users use cfg80211_get_bss()
to get a reference to a BSS struct, they may end
up getting one that would have been removed from
the list if there had been any userspace access
to the list. This leads to inconsistencies and
problems.

Fix it by making cfg80211_get_bss() ignore BSSes
that cfg80211_bss_expire() would remove.

Fixes http://bugzilla.intellinuxwireless.org/show_bug.cgi?id=2180

Cc: stable@kernel.org
Reported-by: Jiajia Zheng 
Tested-by: Jiajia Zheng 
Signed-off-by: Johannes Berg 
Signed-off-by: John W. Linville