mac80211: Send Layer 2 Update frame on reassociation

When a STA roams back to the same AP before the previous STA entry has
expired, a new STA entry is not added in mac80211. However, a Layer 2
Update frame still needs to be transmitted to update layer 2 devices
about the new location for the STA. Without this, switches may
continue to forward frames to the previous (now incorrect) port when
STA roams between APs.

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 11 insertions, 2 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 3ea0884c9432..9d4e4d846ec1 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -686,6 +686,7 @@ static int ieee80211_add_station(struct wiphy *wiphy, struct net_device *dev,
         struct sta_info *sta;
         struct ieee80211_sub_if_data *sdata;
         int err;
+        int layer2_update;
 
         /* Prevent a race with changing the rate control algorithm */
         if (!netif_running(dev))
@@ -716,17 +717,25 @@ static int ieee80211_add_station(struct wiphy *wiphy, struct net_device *dev,
 
         rate_control_rate_init(sta);
 
+        layer2_update = sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
+                sdata->vif.type == NL80211_IFTYPE_AP;
+
         rcu_read_lock();
 
         err = sta_info_insert(sta);
         if (err) {
                 /* STA has been freed */
+                if (err == -EEXIST && layer2_update) {
+                        /* Need to update layer 2 devices on reassociation */
+                        sta = sta_info_get(local, mac);
+                        if (sta)
+                                ieee80211_send_layer2_update(sta);
+                }
                 rcu_read_unlock();
                 return err;
         }
 
-        if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
-            sdata->vif.type == NL80211_IFTYPE_AP)
+        if (layer2_update)
                 ieee80211_send_layer2_update(sta);
 
         rcu_read_unlock();