cfg80211: fix channel configuration in IBSS join

When receiving an IBSS_JOINED event select the BSS object
based on the {bssid, channel} couple rather than the bssid
only.
With the current approach if another cell having the same
BSSID (but using a different channel) exists then cfg80211
picks up the wrong BSS object.
The result is a mismatching channel configuration between
cfg80211 and the driver, that can lead to any sort of
problem.

The issue can be triggered by having an IBSS sitting on
given channel and then asking the driver to create a new
cell using the same BSSID but with a different frequency.
By passing the channel to cfg80211_get_bss() we can solve
this ambiguity and retrieve/create the correct BSS object.
All the users of cfg80211_ibss_joined() have been changed
accordingly.

Moreover WARN when cfg80211_ibss_joined() gets a NULL
channel as argument and remove a bogus call of the same
function in ath6kl (it does not make sense to call
cfg80211_ibss_joined() with a zero BSSID on ibss-leave).

Cc: Kalle Valo <kvalo@qca.qualcomm.com>
Cc: Arend van Spriel <arend@broadcom.com>
Cc: Bing Zhao <bzhao@marvell.com>
Cc: Jussi Kivilinna <jussi.kivilinna@iki.fi>
Cc: libertas-dev@lists.infradead.org
Acked-by: Kalle Valo <kvalo@qca.qualcomm.com>
Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
[minor code cleanup in ath6kl]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 009290e36d15..c68201d78b90 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -3895,6 +3895,7 @@ void cfg80211_michael_mic_failure(struct net_device *dev, const u8 *addr,
  *
  * @dev: network device
  * @bssid: the BSSID of the IBSS joined
+ * @channel: the channel of the IBSS joined
  * @gfp: allocation flags
  *
  * This function notifies cfg80211 that the device joined an IBSS or
@@ -3904,7 +3905,8 @@ void cfg80211_michael_mic_failure(struct net_device *dev, const u8 *addr,
  * with the locally generated beacon -- this guarantees that there is
  * always a scan result for this IBSS. cfg80211 will handle the rest.
  */
-void cfg80211_ibss_joined(struct net_device *dev, const u8 *bssid, gfp_t gfp);
+void cfg80211_ibss_joined(struct net_device *dev, const u8 *bssid,
+                          struct ieee80211_channel *channel, gfp_t gfp);
 
 /**
  * cfg80211_notify_new_candidate - notify cfg80211 of a new mesh peer candidate