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, 99 insertions, 1 deletions

diff --git a/net/wireless/core.h b/net/wireless/core.h
index 92da612b3f9..5ccd642e183 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -57,12 +57,14 @@ struct cfg80211_registered_device {
 	u32 bss_generation;
 	struct cfg80211_scan_request *scan_req; /* protected by RTNL */
 	unsigned long suspend_at;
+	struct work_struct scan_done_wk;
 
 #ifdef CONFIG_NL80211_TESTMODE
 	struct genl_info *testmode_info;
 #endif
 
 	struct work_struct conn_work;
+	struct work_struct event_work;
 
 #ifdef CONFIG_CFG80211_DEBUGFS
 	/* Debugfs entries */
@@ -170,12 +172,73 @@ struct wiphy *wiphy_idx_to_wiphy(int wiphy_idx);
 extern struct cfg80211_registered_device *
 cfg80211_get_dev_from_ifindex(int ifindex);
 
+static inline void cfg80211_lock_rdev(struct cfg80211_registered_device *drv)
+{
+	mutex_lock(&drv->mtx);
+}
+
 static inline void cfg80211_unlock_rdev(struct cfg80211_registered_device *drv)
 {
 	BUG_ON(IS_ERR(drv) || !drv);
 	mutex_unlock(&drv->mtx);
 }
 
+static inline void wdev_lock(struct wireless_dev *wdev)
+	__acquires(wdev)
+{
+	mutex_lock(&wdev->mtx);
+	__acquire(wdev->mtx);
+}
+
+static inline void wdev_unlock(struct wireless_dev *wdev)
+	__releases(wdev)
+{
+	__release(wdev->mtx);
+	mutex_unlock(&wdev->mtx);
+}
+
+#define ASSERT_RDEV_LOCK(rdev) WARN_ON(!mutex_is_locked(&(rdev)->mtx));
+#define ASSERT_WDEV_LOCK(wdev) WARN_ON(!mutex_is_locked(&(wdev)->mtx));
+
+enum cfg80211_event_type {
+	EVENT_CONNECT_RESULT,
+	EVENT_ROAMED,
+	EVENT_DISCONNECTED,
+	EVENT_IBSS_JOINED,
+};
+
+struct cfg80211_event {
+	struct list_head list;
+	enum cfg80211_event_type type;
+
+	union {
+		struct {
+			u8 bssid[ETH_ALEN];
+			const u8 *req_ie;
+			const u8 *resp_ie;
+			size_t req_ie_len;
+			size_t resp_ie_len;
+			u16 status;
+		} cr;
+		struct {
+			u8 bssid[ETH_ALEN];
+			const u8 *req_ie;
+			const u8 *resp_ie;
+			size_t req_ie_len;
+			size_t resp_ie_len;
+		} rm;
+		struct {
+			const u8 *ie;
+			size_t ie_len;
+			u16 reason;
+		} dc;
+		struct {
+			u8 bssid[ETH_ALEN];
+		} ij;
+	};
+};
+
+
 /* free object */
 extern void cfg80211_dev_free(struct cfg80211_registered_device *drv);
 
@@ -191,25 +254,46 @@ void cfg80211_bss_age(struct cfg80211_registered_device *dev,
                       unsigned long age_secs);
 
 /* IBSS */
+int __cfg80211_join_ibss(struct cfg80211_registered_device *rdev,
+			 struct net_device *dev,
+			 struct cfg80211_ibss_params *params);
 int cfg80211_join_ibss(struct cfg80211_registered_device *rdev,
 		       struct net_device *dev,
 		       struct cfg80211_ibss_params *params);
 void cfg80211_clear_ibss(struct net_device *dev, bool nowext);
 int cfg80211_leave_ibss(struct cfg80211_registered_device *rdev,
 			struct net_device *dev, bool nowext);
+void __cfg80211_ibss_joined(struct net_device *dev, const u8 *bssid);
 
 /* MLME */
+int __cfg80211_mlme_auth(struct cfg80211_registered_device *rdev,
+			 struct net_device *dev,
+			 struct ieee80211_channel *chan,
+			 enum nl80211_auth_type auth_type,
+			 const u8 *bssid,
+			 const u8 *ssid, int ssid_len,
+			 const u8 *ie, int ie_len);
 int cfg80211_mlme_auth(struct cfg80211_registered_device *rdev,
 		       struct net_device *dev, struct ieee80211_channel *chan,
 		       enum nl80211_auth_type auth_type, const u8 *bssid,
 		       const u8 *ssid, int ssid_len,
 		       const u8 *ie, int ie_len);
+int __cfg80211_mlme_assoc(struct cfg80211_registered_device *rdev,
+			  struct net_device *dev,
+			  struct ieee80211_channel *chan,
+			  const u8 *bssid, const u8 *prev_bssid,
+			  const u8 *ssid, int ssid_len,
+			  const u8 *ie, int ie_len, bool use_mfp,
+			  struct cfg80211_crypto_settings *crypt);
 int cfg80211_mlme_assoc(struct cfg80211_registered_device *rdev,
 			struct net_device *dev, struct ieee80211_channel *chan,
 			const u8 *bssid, const u8 *prev_bssid,
 			const u8 *ssid, int ssid_len,
 			const u8 *ie, int ie_len, bool use_mfp,
 			struct cfg80211_crypto_settings *crypt);
+int __cfg80211_mlme_deauth(struct cfg80211_registered_device *rdev,
+			   struct net_device *dev, const u8 *bssid,
+			   const u8 *ie, int ie_len, u16 reason);
 int cfg80211_mlme_deauth(struct cfg80211_registered_device *rdev,
 			 struct net_device *dev, const u8 *bssid,
 			 const u8 *ie, int ie_len, u16 reason);
@@ -218,24 +302,38 @@ int cfg80211_mlme_disassoc(struct cfg80211_registered_device *rdev,
 			   const u8 *ie, int ie_len, u16 reason);
 void cfg80211_mlme_down(struct cfg80211_registered_device *rdev,
 			struct net_device *dev);
+void __cfg80211_connect_result(struct net_device *dev, const u8 *bssid,
+			       const u8 *req_ie, size_t req_ie_len,
+			       const u8 *resp_ie, size_t resp_ie_len,
+			       u16 status, bool wextev);
 
 /* SME */
+int __cfg80211_connect(struct cfg80211_registered_device *rdev,
+		       struct net_device *dev,
+		       struct cfg80211_connect_params *connect);
 int cfg80211_connect(struct cfg80211_registered_device *rdev,
 		     struct net_device *dev,
 		     struct cfg80211_connect_params *connect);
+int __cfg80211_disconnect(struct cfg80211_registered_device *rdev,
+			  struct net_device *dev, u16 reason,
+			  bool wextev);
 int cfg80211_disconnect(struct cfg80211_registered_device *rdev,
 			struct net_device *dev, u16 reason,
 			bool wextev);
+void __cfg80211_roamed(struct wireless_dev *wdev, const u8 *bssid,
+		       const u8 *req_ie, size_t req_ie_len,
+		       const u8 *resp_ie, size_t resp_ie_len);
 
 void cfg80211_conn_work(struct work_struct *work);
 
 /* internal helpers */
 int cfg80211_validate_key_settings(struct key_params *params, int key_idx,
 				   const u8 *mac_addr);
-void __cfg80211_disconnected(struct net_device *dev, gfp_t gfp, u8 *ie,
+void __cfg80211_disconnected(struct net_device *dev, const u8 *ie,
 			     size_t ie_len, u16 reason, bool from_ap);
 void cfg80211_sme_scan_done(struct net_device *dev);
 void cfg80211_sme_rx_auth(struct net_device *dev, const u8 *buf, size_t len);
 void cfg80211_sme_disassoc(struct net_device *dev, int idx);
+void __cfg80211_scan_done(struct work_struct *wk);
 
 #endif /* __NET_WIRELESS_CORE_H */