This patch fixes a double free corruption in __cfg80211_scan_done:

 ================================================
 BUG kmalloc-512: Object already free
 ------------------------------------------------

 INFO: Allocated in load_elf_binary+0x18b/0x19af age=6
 INFO: Freed in load_elf_binary+0x104e/0x19af age=5
 INFO: Slab 0xffffea0001bae4c0 objects=14 used=7
 INFO: Object 0xffff88007e8a9918 @offset=6424 fp=0xffff88007e8a9488

 Bytes b4 0xffff88007e8a9908:  00 00 00 00 00 00 00 00 5a 5a
 [...]
 Pid: 28705, comm: rmmod Tainted: P         C 2.6.31-rc2-wl #1
 Call Trace:
  [<ffffffff810da9f4>] print_trailer+0x14e/0x16e
  [<ffffffff810daa56>] object_err+0x42/0x61
  [<ffffffff810dbcd9>] __slab_free+0x2af/0x396
  [<ffffffffa0ec9694>] ? wiphy_unregister+0x92/0x142 [cfg80211]
  [<ffffffff810dd5e3>] kfree+0x13c/0x17a
  [<ffffffffa0ec9694>] ? wiphy_unregister+0x92/0x142 [cfg80211]
  [<ffffffffa0ec9694>] wiphy_unregister+0x92/0x142 [cfg80211]
  [<ffffffffa0eed163>] ieee80211_unregister_hw+0xc8/0xff [mac80211]
  [<ffffffffa0f3fbc8>] p54_unregister_common+0x31/0x66 [p54common]
  [...]
 FIX kmalloc-512: Object at 0xffff88007e8a9918 not freed

The code path which leads to the *funny* double free:

       request = rdev->scan_req;
       dev = dev_get_by_index(&init_net, request->ifidx);
	/*
	 * the driver was unloaded recently and
	 * therefore dev_get_by_index will return NULL!
	 */
        if (!dev)
                goto out;
	[...]
	rdev->scan_req = NULL; /* not executed... */
	[...]
 out:
        kfree(request);
Signed-off-by: NChristian Lamparter <chunkeey@web.de>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The code in cfg80211's cfg80211_bss_update erroneously
grabs a reference to the BSS, which means that it will
never be freed.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Cc: stable@kernel.org [2.6.29, 2.6.30]
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When a scan finishes only the program that asked for it
knows what kind of scan it was; let's tell everybody else
about the scan parameters as well so they can evaluate
the result of the scan better. Also helps with debugging.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

If the IE buffer was allocated, the pub.information_elements pointer
was also changed to the allocated space. So we must not assume anymore
that the pointer points at the "found" tail.

So if it was allocated previously, take the codebranch that grows the
buffer size (if necessary) and put the data into the allocated buffer.
Signed-off-by: NMichael Buesch <mb@bu3sch.de>
Acked-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This removes an unnecessary ksize() call. krealloc() will do this
test internally and won't perform any allocation if the space is
already sufficient to hold the data.
So remove the redundant check.
Signed-off-by: NMichael Buesch <mb@bu3sch.de>
Reviewed-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Another bug in the "cfg80211: do not replace BSS structs" patch,
a forgotten length update leads to bogus data being stored and
passed to userspace, often truncated.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The fact that these are exported is a technical detail
of the conversion period -- we don't want anybody to
start relying on these. Ultimately we want things to
use cfg80211 only, and once everything that is in wext
is converted to cfg80211 drivers will not need to touch
wext _at all_.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Added cfg80211_inform_bss() for full-mac devices to use.
Signed-off-by: NJussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Instead, allocate extra IE memory if necessary. Normally,
this isn't even necessary since there's enough space.

This is a better way of correcting the "held BSS can
disappear" issue, but also a lot more code. It is also
necessary for proper auth/assoc BSS handling in the
future.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When we receive a probe response frame we can replace the
BSS struct in our list -- but if that struct is held then
we need to hold the new one as well.

We really should fix this completely and not replace the
struct, but this is a bandaid for now.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

In beacon filtering there needs to be a way to not expire the BSS even
when no beacons are received. Add an interface to cfg80211 to hold
BSS and make sure that it's not expired.
Signed-off-by: NKalle Valo <kalle.valo@nokia.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When devices are world roaming they cannot beacon or do active scan
on 5 GHz or on channels 12, 13 and 14 on the 2 GHz band. Although
we have a good regulatory API some cards may _always_ world roam, this
is also true when a system does not have CRDA present. Devices doing world
roaming can still passive scan, if they find a beacon from an AP on
one of the world roaming frequencies we make the assumption we can do
the same and we also remove the passive scan requirement.

This adds support for providing beacon regulatory hints based on scans.
This works for devices that do either hardware or software scanning.
If a channel has not yet been marked as having had a beacon present
on it we queue the beacon hint processing into the workqueue.

All wireless devices will benefit from beacon regulatory hints from
any wireless device on a system including new devices connected to
the system at a later time.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

It wasn't a good idea to make the signal type a per-BSS option,
although then it is closer to the actual value. Move it to be
a per-wiphy setting, update mac80211 to match.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Due to various bugs in the software stack we end up having
to fill qual.qual; level should be used, but wpa_supplicant
doesn't properly ignore qual.qual, NM should use qual.level
regardless of that because qual.qual is 0 but doesn't handle
IW_QUAL_DBM right now.

So fill qual.qual with the qual.level value clamped to
-110..-40 dBm or just the regular 'unspecified' signal level.
This requires a mac80211 change to properly announce the
max_qual.qual and avg_qual.qual values.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Scanned BSS entries are timestamped with jiffies, which doesn't
increment across suspend and hibernate.  On resume, every BSS in the
scan list looks like it was scanned within the last 10 seconds,
irregardless of how long the machine was actually asleep.  Age scan
results on resume with the time spent during sleep so userspace has a
clue how old they really are.
Signed-off-by: NDan Williams <dcbw@redhat.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Add a more flexible BSS lookup function so that mac80211 or
other drivers can actually use this for getting the BSS to
connect to.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch introduces cfg80211_unlink_bss, a function to
allow a driver to remove a BSS from the internal list and
make it not show up in scan results any more -- this is
to be used when the driver detects that the BSS is no
longer available.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When cfg80211 users have their own allocated data in the per-BSS
private data, they will need to free this when the BSS struct is
destroyed. Add a free_priv method and fix one place where the BSS
was kfree'd rather than released properly.
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>