mac80211: add beacon filtering support

Add IEEE80211_HW_BEACON_FILTERING flag so that driver inform that it supports
beacon filtering. Drivers need to call the new function
ieee80211_beacon_loss() to notify about beacon loss.

Signed-off-by: Kalle Valo <kalle.valo@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 53 insertions, 1 deletions

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 8a617a7fc09..acba78e1a5c 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -275,6 +275,7 @@ struct ieee80211_if_managed {
 	struct timer_list chswitch_timer;
 	struct work_struct work;
 	struct work_struct chswitch_work;
+	struct work_struct beacon_loss_work;
 
 	u8 bssid[ETH_ALEN], prev_bssid[ETH_ALEN];
 
@@ -1086,6 +1087,7 @@ void ieee80211_send_nullfunc(struct ieee80211_local *local,
 			     int powersave);
 void ieee80211_sta_rx_notify(struct ieee80211_sub_if_data *sdata,
 			     struct ieee80211_hdr *hdr);
+void ieee80211_beacon_loss_work(struct work_struct *work);
 
 void ieee80211_wake_queues_by_reason(struct ieee80211_hw *hw,
 				     enum queue_stop_reason reason);
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index dd2a276fa8c..91e8e1bacaa 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -477,6 +477,9 @@ static int ieee80211_stop(struct net_device *dev)
 		 */
 		cancel_work_sync(&sdata->u.mgd.work);
 		cancel_work_sync(&sdata->u.mgd.chswitch_work);
+
+		cancel_work_sync(&sdata->u.mgd.beacon_loss_work);
+
 		/*
 		 * When we get here, the interface is marked down.
 		 * Call synchronize_rcu() to wait for the RX path
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 8f30f4d19da..7ecda9d59d8 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -610,6 +610,8 @@ static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
 		bss_info_changed |= ieee80211_handle_bss_capability(sdata,
 			bss->cbss.capability, bss->has_erp_value, bss->erp_value);
 
+		cfg80211_hold_bss(&bss->cbss);
+
 		ieee80211_rx_bss_put(local, bss);
 	}
 
@@ -751,6 +753,8 @@ static void ieee80211_set_disassoc(struct ieee80211_sub_if_data *sdata,
 {
 	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
 	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_conf *conf = &local_to_hw(local)->conf;
+	struct ieee80211_bss *bss;
 	struct sta_info *sta;
 	u32 changed = 0, config_changed = 0;
 
@@ -774,6 +778,15 @@ static void ieee80211_set_disassoc(struct ieee80211_sub_if_data *sdata,
 
 	ieee80211_sta_tear_down_BA_sessions(sta);
 
+	bss = ieee80211_rx_bss_get(local, ifmgd->bssid,
+				   conf->channel->center_freq,
+				   ifmgd->ssid, ifmgd->ssid_len);
+
+	if (bss) {
+		cfg80211_unhold_bss(&bss->cbss);
+		ieee80211_rx_bss_put(local, bss);
+	}
+
 	if (self_disconnected) {
 		if (deauth)
 			ieee80211_send_deauth_disassoc(sdata,
@@ -925,6 +938,33 @@ void ieee80211_sta_rx_notify(struct ieee80211_sub_if_data *sdata,
 			  jiffies + IEEE80211_MONITORING_INTERVAL);
 }
 
+void ieee80211_beacon_loss_work(struct work_struct *work)
+{
+	struct ieee80211_sub_if_data *sdata =
+		container_of(work, struct ieee80211_sub_if_data,
+			     u.mgd.beacon_loss_work);
+	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
+
+	printk(KERN_DEBUG "%s: driver reports beacon loss from AP %pM "
+	       "- sending probe request\n", sdata->dev->name,
+	       sdata->u.mgd.bssid);
+
+	ifmgd->flags |= IEEE80211_STA_PROBEREQ_POLL;
+	ieee80211_send_probe_req(sdata, ifmgd->bssid, ifmgd->ssid,
+				 ifmgd->ssid_len, NULL, 0);
+
+	mod_timer(&ifmgd->timer, jiffies + IEEE80211_MONITORING_INTERVAL);
+}
+
+void ieee80211_beacon_loss(struct ieee80211_vif *vif)
+{
+	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+
+	queue_work(sdata->local->hw.workqueue,
+		   &sdata->u.mgd.beacon_loss_work);
+}
+EXPORT_SYMBOL(ieee80211_beacon_loss);
+
 static void ieee80211_associated(struct ieee80211_sub_if_data *sdata)
 {
 	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
@@ -959,7 +999,13 @@ static void ieee80211_associated(struct ieee80211_sub_if_data *sdata)
 		goto unlock;
 	}
 
-	if (time_after(jiffies,
+	/*
+	 * Beacon filtering is only enabled with power save and then the
+	 * stack should not check for beacon loss.
+	 */
+	if (!((local->hw.flags & IEEE80211_HW_BEACON_FILTER) &&
+	      (local->hw.conf.flags & IEEE80211_CONF_PS)) &&
+	    time_after(jiffies,
 		       ifmgd->last_beacon + IEEE80211_MONITORING_INTERVAL)) {
 		printk(KERN_DEBUG "%s: beacon loss from AP %pM "
 		       "- sending probe request\n",
@@ -1869,6 +1915,7 @@ void ieee80211_sta_setup_sdata(struct ieee80211_sub_if_data *sdata)
 	ifmgd = &sdata->u.mgd;
 	INIT_WORK(&ifmgd->work, ieee80211_sta_work);
 	INIT_WORK(&ifmgd->chswitch_work, ieee80211_chswitch_work);
+	INIT_WORK(&ifmgd->beacon_loss_work, ieee80211_beacon_loss_work);
 	setup_timer(&ifmgd->timer, ieee80211_sta_timer,
 		    (unsigned long) sdata);
 	setup_timer(&ifmgd->chswitch_timer, ieee80211_chswitch_timer,