mac80211: disconnect if channel switch fails

Disconnect from the AP if channel switching in the
driver failed or if the new channel is unavailable.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

2 files changed, 38 insertions, 18 deletions

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 0a983fbd743d..e2ab03c773e3 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -411,6 +411,7 @@ struct ieee80211_if_managed {
         struct work_struct monitor_work;
         struct work_struct chswitch_work;
         struct work_struct beacon_connection_loss_work;
+        struct work_struct csa_connection_drop_work;
 
         unsigned long beacon_timeout;
         unsigned long probe_timeout;
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 5d77650d4363..6e374cb04af6 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -730,16 +730,13 @@ void ieee80211_chswitch_done(struct ieee80211_vif *vif, bool success)
 
         trace_api_chswitch_done(sdata, success);
         if (!success) {
-                /*
-                 * If the channel switch was not successful, stay
-                 * around on the old channel. We currently lack
-                 * good handling of this situation, possibly we
-                 * should just drop the association.
-                 */
-                sdata->local->csa_channel = sdata->local->oper_channel;
+                sdata_info(sdata,
+                           "driver channel switch failed, disconnecting\n");
+                ieee80211_queue_work(&sdata->local->hw,
+                                     &ifmgd->csa_connection_drop_work);
+        } else {
+                ieee80211_queue_work(&sdata->local->hw, &ifmgd->chswitch_work);
         }
-
-        ieee80211_queue_work(&sdata->local->hw, &ifmgd->chswitch_work);
 }
 EXPORT_SYMBOL(ieee80211_chswitch_done);
 
@@ -784,8 +781,14 @@ void ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
                 return;
 
         new_ch = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
-        if (!new_ch || new_ch->flags & IEEE80211_CHAN_DISABLED)
+        if (!new_ch || new_ch->flags & IEEE80211_CHAN_DISABLED) {
+                sdata_info(sdata,
+                           "AP %pM switches to unsupported channel (%d MHz), disconnecting\n",
+                           ifmgd->associated->bssid, new_freq);
+                ieee80211_queue_work(&sdata->local->hw,
+                                     &ifmgd->csa_connection_drop_work);
                 return;
+        }
 
         sdata->local->csa_channel = new_ch;
 
@@ -1692,7 +1695,8 @@ struct sk_buff *ieee80211_ap_probereq_get(struct ieee80211_hw *hw,
 }
 EXPORT_SYMBOL(ieee80211_ap_probereq_get);
 
-static void __ieee80211_connection_loss(struct ieee80211_sub_if_data *sdata)
+static void __ieee80211_disconnect(struct ieee80211_sub_if_data *sdata,
+                                   bool transmit_frame)
 {
         struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
         struct ieee80211_local *local = sdata->local;
@@ -1704,12 +1708,10 @@ static void __ieee80211_connection_loss(struct ieee80211_sub_if_data *sdata)
                 return;
         }
 
-        sdata_info(sdata, "Connection to AP %pM lost\n",
-                   ifmgd->associated->bssid);
-
         ieee80211_set_disassoc(sdata, IEEE80211_STYPE_DEAUTH,
                                WLAN_REASON_DISASSOC_DUE_TO_INACTIVITY,
-                               false, frame_buf);
+                               transmit_frame, frame_buf);
+        ifmgd->flags &= ~IEEE80211_STA_CSA_RECEIVED;
         mutex_unlock(&ifmgd->mtx);
 
         /*
@@ -1739,10 +1741,24 @@ static void ieee80211_beacon_connection_loss_work(struct work_struct *work)
                 rcu_read_unlock();
         }
 
-        if (sdata->local->hw.flags & IEEE80211_HW_CONNECTION_MONITOR)
-                __ieee80211_connection_loss(sdata);
-        else
+        if (sdata->local->hw.flags & IEEE80211_HW_CONNECTION_MONITOR) {
+                sdata_info(sdata, "Connection to AP %pM lost\n",
+                           ifmgd->bssid);
+                __ieee80211_disconnect(sdata, false);
+        } else {
                 ieee80211_mgd_probe_ap(sdata, true);
+        }
+}
+
+static void ieee80211_csa_connection_drop_work(struct work_struct *work)
+{
+        struct ieee80211_sub_if_data *sdata =
+                container_of(work, struct ieee80211_sub_if_data,
+                             u.mgd.csa_connection_drop_work);
+
+        ieee80211_wake_queues_by_reason(&sdata->local->hw,
+                                        IEEE80211_QUEUE_STOP_REASON_CSA);
+        __ieee80211_disconnect(sdata, true);
 }
 
 void ieee80211_beacon_loss(struct ieee80211_vif *vif)
@@ -2929,6 +2945,7 @@ void ieee80211_sta_quiesce(struct ieee80211_sub_if_data *sdata)
 
         cancel_work_sync(&ifmgd->monitor_work);
         cancel_work_sync(&ifmgd->beacon_connection_loss_work);
+        cancel_work_sync(&ifmgd->csa_connection_drop_work);
         if (del_timer_sync(&ifmgd->timer))
                 set_bit(TMR_RUNNING_TIMER, &ifmgd->timers_running);
 
@@ -2985,6 +3002,8 @@ void ieee80211_sta_setup_sdata(struct ieee80211_sub_if_data *sdata)
         INIT_WORK(&ifmgd->chswitch_work, ieee80211_chswitch_work);
         INIT_WORK(&ifmgd->beacon_connection_loss_work,
                   ieee80211_beacon_connection_loss_work);
+        INIT_WORK(&ifmgd->csa_connection_drop_work,
+                  ieee80211_csa_connection_drop_work);
         INIT_WORK(&ifmgd->request_smps_work, ieee80211_request_smps_work);
         setup_timer(&ifmgd->timer, ieee80211_sta_timer,
                     (unsigned long) sdata);