cfg80211: fix locking

Over time, a lot of locking issues have crept into
the smarts of cfg80211, so e.g. scan completion can
race against a new scan, IBSS join can race against
leaving an IBSS, etc.

Introduce a new per-interface lock that protects
most of the per-interface data that we need to keep
track of, and sprinkle assertions about that lock
everywhere. Some things now need to be offloaded to
work structs so that we don't require being able to
sleep in functions the drivers call. The exception
to that are the MLME callbacks (rx_auth etc.) that
currently only mac80211 calls because it was easier
to do that there instead of in cfg80211, and future
drivers implementing those calls will, if they ever
exist, probably need to use a similar scheme like
mac80211 anyway...

In order to be able to handle _deauth and _disassoc
properly, introduce a cookie passed to it that will
determine locking requirements.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 8 insertions, 4 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 7cfc14e4ca07..36f8f245fa4c 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1182,15 +1182,19 @@ static int ieee80211_assoc(struct wiphy *wiphy, struct net_device *dev,
 }
 
 static int ieee80211_deauth(struct wiphy *wiphy, struct net_device *dev,
-                            struct cfg80211_deauth_request *req)
+                            struct cfg80211_deauth_request *req,
+                            void *cookie)
 {
-        return ieee80211_mgd_deauth(IEEE80211_DEV_TO_SUB_IF(dev), req);
+        return ieee80211_mgd_deauth(IEEE80211_DEV_TO_SUB_IF(dev),
+                                    req, cookie);
 }
 
 static int ieee80211_disassoc(struct wiphy *wiphy, struct net_device *dev,
-                              struct cfg80211_disassoc_request *req)
+                              struct cfg80211_disassoc_request *req,
+                              void *cookie)
 {
-        return ieee80211_mgd_disassoc(IEEE80211_DEV_TO_SUB_IF(dev), req);
+        return ieee80211_mgd_disassoc(IEEE80211_DEV_TO_SUB_IF(dev),
+                                      req, cookie);
 }
 
 static int ieee80211_join_ibss(struct wiphy *wiphy, struct net_device *dev,