Also add tracing to the API functions that drivers
(and mac80211) can call in cfg80211.
Signed-off-by: Beni Lev <beni.lev@intel.com>
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This will allow adding central tracing like in mac80211.
Signed-off-by: Hila Gonen <hila.gonen@intel.com>
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Add an NL80211_SCAN_FLAG_FLUSH flag that causes old bss cache
entries to be flushed on scan completion. This is useful for
collecting guaranteed fresh scan/survey result (e.g. on resume).
For normal scan, flushing only happens on successful completion
of a scan; i.e. it does not happen if the scan is aborted.
For scheduled scan, previous scan results are flushed everytime
when we get new scan results.
This feature is enabled by default. Drivers can disable it by
unsetting the NL80211_FEATURE_SCAN_FLUSH flag.
Signed-off-by: Sam Leffler <sleffler@chromium.org>
Tested-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
[invert polarity of feature flag to account for old kernels]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
bss_release() and __cfg80211_unlink_bss() function definitions
are moved at the begining of the file. They are used in next
patch in this series.
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The new P2P Device will have to be able to scan for
P2P search, so move scanning to use struct wireless_dev
instead of struct net_device.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Use the new bool function ether_addr_equal to add
some clarity and reduce the likelihood for misuse
of compare_ether_addr for sorting.
I removed a conversion from scan.c/cmp_bss_core
that appears to be a sorting function.
Done via cocci script:
$ cat compare_ether_addr.cocci
@@
expression a,b;
@@
- !compare_ether_addr(a, b)
+ ether_addr_equal(a, b)
@@
expression a,b;
@@
- compare_ether_addr(a, b)
+ !ether_addr_equal(a, b)
@@
expression a,b;
@@
- !ether_addr_equal(a, b) == 0
+ ether_addr_equal(a, b)
@@
expression a,b;
@@
- !ether_addr_equal(a, b) != 0
+ !ether_addr_equal(a, b)
@@
expression a,b;
@@
- ether_addr_equal(a, b) == 0
+ !ether_addr_equal(a, b)
@@
expression a,b;
@@
- ether_addr_equal(a, b) != 0
+ ether_addr_equal(a, b)
@@
expression a,b;
@@
- !!ether_addr_equal(a, b)
+ ether_addr_equal(a, b)
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since the BSS table is organized in a RB tree, the BSSs need to be
comparable. This means that we must define a < and > operator to
the BSS object.
compare_ethr_addr isn't enough since it returns only a binary value.
Since Felix's
cfg80211: use compare_ether_addr on MAC addresses instead of memcmp
Because of the constant size and guaranteed 16 bit alignment, the inline
compare_ether_addr function is much cheaper than calling memcmp.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The BSS table is corrupted: rb_find_bss can't find the bss.
As a result BSSes are duplicated in the BSS table, and we get stuck
while probing an AP before associating (in STA mode).
Change-Id: I85928756f4328028230832c1565ece7f412f3843
CC: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Acked-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The background scan completion takes more time when the station is
having heavy uplink traffic. The scan state machine decides to fall
back to home channel on every off-channel visit when there are pending
frames in tx queue. bgscan completion took ~30sec on dual band US
regulatory card.
scan period = (20 active channels * probe timeout) +
(12 passive channels * passive probe timeout) +
(32 * timeout on home channel) +
(32 * flush timeout)
Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Because of the constant size and guaranteed 16 bit alignment, the inline
compare_ether_addr function is much cheaper than calling memcmp.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This is intended to be the timestamp sent by the
peer in the beacon/probe response, not any form
of host timestamp. Clarify the documentation and
variable names.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This is needed by mac80211 to keep a reference
to a BSS alive for the auth process. Remove the
old version of cfg80211_ref_bss() since it's
not actually used.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The problem with PSM when a hidden SSID was used was originally
reported by Juuso Oikarinen.
- When generally scanning, the AP is getting a bss entry with
a zero SSID.
- When associating, a probe-req is sent to the AP with the SSID,
and as a result a probe-response is received with the hidden
SSID in place. As a consequence, a second bss entry is created
for the AP, now with the real SSID.
- After association, mac80211 executes ieee80211_recalc_ps(),
but does not switch to powersave because the beacon-ies are missing.
As result, the STA does not ever enter PSM.
The patch merges in beacon ies of hidden bss from beacon to the probe
response, creating a consistent set of ies in place.
Patch is depended on "cfg80211: fix cmp_ies" made by Johannes.
Signed-off-by: Dmitry Tarnyagin <dmitry.tarnyagin@stericsson.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When comparing two items by IE, the sort order
wasn't stable, which could lead to issues in the
rbtree. Make it stable by making a missing IE
sort before a present IE.
Also sort by length first if it differs and then
by contents.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Add function to find vendor-specific ie (along with
vendor-specific ie struct definition and P2P OUI values)
Signed-off-by: Eliad Peller <eliad@wizery.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
A lot of drivers erroneously use wext constants
and don't notice since cfg80211.h includes them.
Make this more split up so drivers needing wext
compatibility from cfg80211 need to explicitly
include that from cfg80211-wext.h.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
commit 58389c69150e6032504dfcd3edca6b1975c8b5bc
Author: Johannes Berg <johannes.berg@intel.com>
Date: Mon Jul 18 18:08:35 2011 +0200
cfg80211: allow userspace to control supported rates in scan
made single-band cards crash since it would always
access all wiphy->bands[]. Fix this and reject any
attempts in the new helper ieee80211_get_ratemask()
to do the same, rejecting rates configuration for
unsupported bands.
Reported-by: Pavel Roskin <proski@gnu.org>
Tested-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Some P2P scans are not allowed to advertise
11b rates, but that is a rather special case
so instead of having that, allow userspace
to request the rate sets (per band) that are
advertised in scan probe request frames.
Since it's needed in two places now, factor
out some common code parsing a rate array.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
If we try to stop a scheduled scan while it is not running, we should
return -ENOENT instead of simply ignoring the command and returning
success. This is more consistent with other parts of the code.
Reported-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Luciano Coelho <coelho@ti.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
If the 'driver_initiated' function argument to
__cfg80211_stop_sched_scan() is not 0 then we'll return an
uninitialized 'err' from the function.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
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: [<ffffffff8164c831>] cfg80211_netdev_notifier_call+0x131/0x5b0
kernel:
kernel: but task is already holding lock:
kernel: (&rdev->devlist_mtx){+.+.+.}, at: [<ffffffff8164dcef>] 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 <duaneg@dghda.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
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 <eliad@wizery.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
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 <johannes@sipsolutions.net>
Signed-off-by: Luciano Coelho <coelho@ti.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
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 <coelho@ti.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
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 <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This patch adds to the fix "fix BSS double-unlinking"
(commit 3207390a8b) 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 <juuso.oikarinen@nokia.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
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 <mk@lab.zgora.pl>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
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 <s.neumann@raumfeld.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
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 <greearb@candelatech.com>
Tested-by: Hun-Kyi Wynn <hkwynn@candelatech.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
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 <jiajia.zheng@intel.com>
Tested-by: Jiajia Zheng <jiajia.zheng@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
signal_type is enum cfg80211_signal_type.
This fixes the gcc warning:
scan.c: In function `cfg80211_inform_bss':
scan.c:518:6: warning: comparison between `enum cfg80211_signal_type' and `enum nl80211_bss'
scan.c: In function `cfg80211_inform_bss_frame':
scan.c:574:6: warning: comparison between `enum cfg80211_signal_type' and `enum nl80211_bss'
Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
This new function (previously a static function
called just "find_ie" can be used to find a
specific IE in a buffer of IEs.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Store information elements from Beacon and Probe Response frames in
separate buffers to allow both sets to be made available through
nl80211. This allows user space applications to get access to IEs from
Beacon frames even if we have received Probe Response frames from the
BSS. Previously, the IEs from Probe Response frames would have
overridden the IEs from Beacon frames.
This feature is of somewhat limited use since most protocols include
the same (or extended) information in Probe Response frames. However,
there are couple of exceptions where the IEs from Beacon frames could
be of some use: TIM IE is only included in Beacon frames (and it would
be needed to figure out the DTIM period used in the BSS) and at least
some implementations of Wireless Provisioning Services seem to include
the full IE only in Beacon frames).
The new BSS attribute for scan results is added to allow both the IE
sets to be delivered. This is done in a way that maintains the
previously used behavior for applications that are not aware of the
new NL80211_BSS_BEACON_IES attribute.
Signed-off-by: Jouni Malinen <j@w1.fi>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
If there's an invalid channel or SSID, the code leaks
the scan request. Always free the scan request, unless
it was successfully given to the driver.
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Not including net/atm/
Compiled tested x86 allyesconfig only
Added a > 80 column line or two, which I ignored.
Existing checkpatch plaints willfully, cheerfully ignored.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch moves the works cleanup, scan and events to a cfg80211
dedicated workqueue.
Platform driver like eeepc-laptop ought to use works to rfkill (as
new rfkill does lock in rfkill_unregister and the platform driver is
called from rfkill_switch_all which also lock the same mutex).
This raise a new issue in itself that the work scheduled by the platform
driver to the global worqueue calls wiphy_unregister which flush_work
scan and event works (which thus flush works on the global workqueue inside
a work on the global workqueue) and also put on hold the wdev_cleanup_work
(which prevents the dev_put on netdev thus indefinite Usage count error on
wifi device).
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Alban Browaeys <prahal@yahoo.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Currently it is possible to request a scan on only
disabled channels, which could be problematic for
some drivers. Reject such scans, and also ignore
disabled channels that are given. This resuls in
the scan begin/end event only including channels
that are actually used.
This makes the mac80211 check for disabled channels
superfluous. At the same time, remove the no-IBSS
check from mac80211 -- nothing says that we should
not find any networks on channels that cannot be
used for an IBSS, even when operating in IBSS mode.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Refactor wext to
* split out iwpriv handling
* split out iwspy handling
* split out procfs support
* allow cfg80211 to have wireless extensions compat code
w/o CONFIG_WIRELESS_EXT
After this, drivers need to
- select WIRELESS_EXT - for wext support
- select WEXT_PRIV - for iwpriv support
- select WEXT_SPY - for iwspy support
except cfg80211 -- which gets new hooks in wext-core.c
and can then get wext handlers without CONFIG_WIRELESS_EXT.
Wireless extensions procfs support is auto-selected
based on PROC_FS and anything that requires the wext core
(i.e. WIRELESS_EXT or CFG80211_WEXT).
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
WEXT's "struct iw_freq" can also be used to handle a channel. This patch now
uses cfg80211_wext_freq() instead of hand-converting the frequency. That
allows user-space to specify channels as well, like with SIOCSIWFREQ.
Signed-off-by: Holger Schurig <hs4233@mail.mn-solutions.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Handles the case when SIOCSIWSCAN specified iw_scan_req.num_channels and
iw_scan_req.channels[].
Signed-off-by: Holger Schurig <hs4233@mail.mn-solutions.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When we lose a scan, cfg80211 tries to clean up after
the driver. However, it currently does this too early,
it does this in GOING_DOWN already instead of DOWN, so
it may happen with mac80211. Besides fixing this, also
make it more robust by leaking the scan request so if
the driver later actually finishes the scan, it won't
crash. Also check in ___cfg80211_scan_done whether a
scan request is still pending and exit if not.
Reported-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Tested-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
If you trigger a scan request on an interface and then
take it down, or rmmod the module or unplug the device
the driver might "forget" to cancel the scan request.
That is a bug in the driver, but the current behaviour
is that we just hang endlessly waiting for the netdev
refcount to become 0 which it never will. To improve
robustness, check for this situation in cfg80211, warn
about it and clean up behind the driver. I don't just
clean up silently because it's likely that the driver
also has some internal state it has now leaked.
Additionally, this fixes a locking bug, clearing the
scan_req pointer should be done under the rdev lock.
Finally, we also need to _wait_ for the scan work and
not just abort it since it might be pending and wanting
to do a cleanup.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
