cfg80211: re-join IBSS when privacy changes

When going from/to a WEP protected IBSS, we need to
leave this one and join a new one to take care of
the changed capability.

Cc: Hong Zhang <henryzhang62@yahoo.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 44 insertions, 11 deletions

diff --git a/net/wireless/core.h b/net/wireless/core.h
index 5aeebb9085f8..a9db9e6255bb 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -273,6 +273,8 @@ int cfg80211_join_ibss(struct cfg80211_registered_device *rdev,
                        struct cfg80211_ibss_params *params,
                        struct cfg80211_cached_keys *connkeys);
 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);
 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);
diff --git a/net/wireless/ibss.c b/net/wireless/ibss.c
index 39b6d92e2828..34dfc93fa713 100644
--- a/net/wireless/ibss.c
+++ b/net/wireless/ibss.c
@@ -169,8 +169,8 @@ void cfg80211_clear_ibss(struct net_device *dev, bool nowext)
         wdev_unlock(wdev);
 }
 
-static int __cfg80211_leave_ibss(struct cfg80211_registered_device *rdev,
-                                 struct net_device *dev, bool nowext)
+int __cfg80211_leave_ibss(struct cfg80211_registered_device *rdev,
+                          struct net_device *dev, bool nowext)
 {
         struct wireless_dev *wdev = dev->ieee80211_ptr;
         int err;
diff --git a/net/wireless/wext-compat.c b/net/wireless/wext-compat.c
index 41abcbdc5fb9..29091ac9f989 100644
--- a/net/wireless/wext-compat.c
+++ b/net/wireless/wext-compat.c
@@ -437,6 +437,7 @@ static int __cfg80211_set_encryption(struct cfg80211_registered_device *rdev,
 {
         struct wireless_dev *wdev = dev->ieee80211_ptr;
         int err, i;
+        bool rejoin = false;
 
         if (!wdev->wext.keys) {
                 wdev->wext.keys = kzalloc(sizeof(*wdev->wext.keys),
@@ -466,8 +467,24 @@ static int __cfg80211_set_encryption(struct cfg80211_registered_device *rdev,
 
         if (remove) {
                 err = 0;
-                if (wdev->current_bss)
+                if (wdev->current_bss) {
+                        /*
+                         * If removing the current TX key, we will need to
+                         * join a new IBSS without the privacy bit clear.
+                         */
+                        if (idx == wdev->wext.default_key &&
+                            wdev->iftype == NL80211_IFTYPE_ADHOC) {
+                                __cfg80211_leave_ibss(rdev, wdev->netdev, true);
+                                rejoin = true;
+                        }
                         err = rdev->ops->del_key(&rdev->wiphy, dev, idx, addr);
+                }
+                /*
+                 * Applications using wireless extensions expect to be
+                 * able to delete keys that don't exist, so allow that.
+                 */
+                if (err == -ENOENT)
+                        err = 0;
                 if (!err) {
                         if (!addr) {
                                 wdev->wext.keys->params[idx].key_len = 0;
@@ -478,12 +495,9 @@ static int __cfg80211_set_encryption(struct cfg80211_registered_device *rdev,
                         else if (idx == wdev->wext.default_mgmt_key)
                                 wdev->wext.default_mgmt_key = -1;
                 }
-                /*
-                 * Applications using wireless extensions expect to be
-                 * able to delete keys that don't exist, so allow that.
-                 */
-                if (err == -ENOENT)
-                        return 0;
+
+                if (!err && rejoin)
+                        err = cfg80211_ibss_wext_join(rdev, wdev);
 
                 return err;
         }
@@ -511,11 +525,25 @@ static int __cfg80211_set_encryption(struct cfg80211_registered_device *rdev,
         if ((params->cipher == WLAN_CIPHER_SUITE_WEP40 ||
              params->cipher == WLAN_CIPHER_SUITE_WEP104) &&
             (tx_key || (!addr && wdev->wext.default_key == -1))) {
-                if (wdev->current_bss)
+                if (wdev->current_bss) {
+                        /*
+                         * If we are getting a new TX key from not having
+                         * had one before we need to join a new IBSS with
+                         * the privacy bit set.
+                         */
+                        if (wdev->iftype == NL80211_IFTYPE_ADHOC &&
+                            wdev->wext.default_key == -1) {
+                                __cfg80211_leave_ibss(rdev, wdev->netdev, true);
+                                rejoin = true;
+                        }
                         err = rdev->ops->set_default_key(&rdev->wiphy,
                                                          dev, idx);
-                if (!err)
+                }
+                if (!err) {
                         wdev->wext.default_key = idx;
+                        if (rejoin)
+                                err = cfg80211_ibss_wext_join(rdev, wdev);
+                }
                 return err;
         }
 
@@ -539,10 +567,13 @@ static int cfg80211_set_encryption(struct cfg80211_registered_device *rdev,
 {
         int err;
 
+        /* devlist mutex needed for possible IBSS re-join */
+        mutex_lock(&rdev->devlist_mtx);
         wdev_lock(dev->ieee80211_ptr);
         err = __cfg80211_set_encryption(rdev, dev, addr, remove,
                                         tx_key, idx, params);
         wdev_unlock(dev->ieee80211_ptr);
+        mutex_unlock(&rdev->devlist_mtx);
 
         return err;
 }