Should help the next person that tries to understand
the bss refcounting logic.
Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Virtually all code paths in cfg80211 already (need to) hold
the RTNL. As such, there's little point in having another
four mutexes for various parts of the code, they just cause
lock ordering issues (and much of the time, the RTNL and a
few of the others need thus be held.)
Simplify all this by getting rid of the extra four mutexes
and just use the RTNL throughout. Only a few code changes
were needed to do this and we can get rid of a work struct
for bonus points.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
If a P2P device wdev is removed while it has a scan, then the
scan completion might crash later as it is already freed by
that time. To avoid the crash always check the scan completion
when the P2P device is being removed for some reason. If the
driver already canceled it, don't want and free it, otherwise
warn and leak it to avoid later crashes.
In order to do this, locking needs to be changed away from the
rdev mutex (which can't always be guaranteed). For now, use
the sched_scan_mtx instead, I'll rename it to just scan_mtx in
a later patch.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
In the odd case that while updating information from a beacon,
a BSS was found that is part of a hidden group, we drop the
new information. In this case, however, we leak the IE buffer
from the update, and erroneously update the entry's timestamp
so it will never time out. Fix both these issues.
Cc: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Add new NL80211_CMD_RADAR_DETECT, which starts the Channel
Availability Check (CAC). This command will also notify the
usermode about events (CAC finished, CAC aborted, radar
detected, NOP finished).
Once radar detection has started it should continuously
monitor for radars as long as the channel is active.
This patch enables DFS for AP mode in nl80211/cfg80211.
Based on original patch by Victor Goldenshtein <victorg@ti.com>
Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
[remove WIPHY_FLAG_HAS_RADAR_DETECT again -- my mistake]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
cfg80211_find_vendor_ie() was checking only that the vendor IE would
fit in the remaining IEs buffer. If a corrupt includes a vendor IE
that is too small, we could potentially overrun the IEs buffer.
Fix this by checking that the vendor IE fits in the reported IE length
field and skip it otherwise.
Reported-by: Jouni Malinen <j@w1.fi>
Signed-off-by: Luciano Coelho <coelho@ti.com>
[change BUILD_BUG_ON to != 1 (from >= 2)]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
While technically the TSF isn't an IE, it can be
necessary to distinguish between the TSF from a
beacon and a probe response, in particular in
order to know the next DTIM TBTT, as not all APs
are spec compliant wrt. TSF==0 being a DTIM TBTT
and thus the DTIM count needs to be taken into
account as well.
To allow this, move the TSF into the IE struct
so it can be known whence it came.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
There's no way scan BSS IEs can be NULL as even
if the allocation fails the frame is discarded.
Remove some code checking for this and document
that it is always non-NULL.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Currently, cfg80211 will copy beacon IEs from a previously
received hidden SSID beacon to a probe response entry, if
that entry is created after the beacon entry. However, if
it is the other way around, or if the beacon is updated,
such changes aren't propagated.
Fix this by tracking the relation between the probe
response and beacon BSS structs in this case.
In case drivers have private data stored in a BSS struct
and need access to such data from a beacon entry, cfg80211
now provides the hidden_beacon_bss pointer from the probe
response entry to the beacon entry.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This prepares for using the spinlock instead of krefs
which is needed in the next patch to track the refs
of combined BSSes correctly.
Acked-by: Bing Zhao <bzhao@marvell.com> [mwifiex]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Instead of annotating with a comment, add a lockdep
annotation which also serves as documentation.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The comment about allocating the IEs together with
the BSS struct is no longer true, remove it. Also
fix a typo in the same area.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
As Thomas pointed out, cfg80211_get_mesh() is
unused and can be removed.
Cc: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Instead of first checking if a BSS is an MBSS
and then doing the comparisons, inline it all
into the BSS comparison function. This avoids
doing the IE searches twice and is also a lot
less code.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
When trying to find a hidden SSID, the lookup function
is done wrong; the code is trying to combine the two
lookups into one, and as a consequence doesn't always
find the entry at all. To understand this, consider a
case where multiple BSS entries with the same channel
and BSSID exist but have different SSID length. Then
comparing against the probe response SSID length is
bound to cause problems since the hidden one might be
either zeroed out or zero-length.
To fix this we need to do two lookups for the two ways
to hide SSIDs.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Instead of duplicating the rbtree functions, pass
an argument to the compare function. This removes
the code duplication for the two searches.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Now that mac80211 no longer uses this API, remove
it completely. If anyone needs it again, we can
revert this patch of course, but mac80211 was the
only user right now.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
We do a:
sprintf(buf, " Last beacon: %ums ago",
elapsed_jiffies_msecs(bss->ts));
elapsed_jiffies_msecs() can return a 10 digit number so "buf" needs to
be 31 characters long.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
When a BSS struct is updated, the IEs are currently
overwritten or freed. This can lead to races if some
other CPU is accessing the BSS struct and using the
IEs concurrently.
Fix this by always allocating the IEs in a new struct
that holds the data and length and protecting access
to this new struct with RCU.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The cmp_bss() comparator function uses memcmp() to
compare the SSID. This means that cmp_hidden_bss()
needs to similarly return a number bigger than zero
(use 1) instead of -1 when ie1 is bigger than ie2,
which is the case if an ie2 byte is non-zero.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
