mac80211: add api to start ba session timer expired flow

Some drivers handle rx buffer reordering internally (and by extension
handle also the rx ba session timer internally), but do not ofload the
addba/delba negotiation.
Add an api for these drivers to properly tear-down the ba session,
including sending a delba.

Signed-off-by: Naftali Goldstein <naftali.goldstein@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

include/net/mac80211.h

@@ -5499,6 +5499,21 @@ static inline void ieee80211_stop_rx_ba_session_offl(struct ieee80211_vif *vif,
 	ieee80211_manage_rx_ba_offl(vif, addr, tid + IEEE80211_NUM_TIDS);
 }
 
+/**
+ * ieee80211_rx_ba_timer_expired - stop a Rx BA session due to timeout
+ *
+ * Some device drivers do not offload AddBa/DelBa negotiation, but handle rx
+ * buffer reording internally, and therefore also handle the session timer.
+ *
+ * Trigger the timeout flow, which sends a DelBa.
+ *
+ * @vif: &struct ieee80211_vif pointer from the add_interface callback
+ * @addr: station mac address
+ * @tid: the rx tid
+ */
+void ieee80211_rx_ba_timer_expired(struct ieee80211_vif *vif,
+				   const u8 *addr, unsigned int tid);
+
 /* Rate control API */
 
 /**

net/mac80211/agg-rx.c

@@ -7,7 +7,7 @@
  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
  * Copyright 2007-2010, Intel Corporation
- * Copyright(c) 2015 Intel Deutschland GmbH
+ * Copyright(c) 2015-2017 Intel Deutschland GmbH
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
@@ -466,3 +466,23 @@ void ieee80211_manage_rx_ba_offl(struct ieee80211_vif *vif,
 	rcu_read_unlock();
 }
 EXPORT_SYMBOL(ieee80211_manage_rx_ba_offl);
+
+void ieee80211_rx_ba_timer_expired(struct ieee80211_vif *vif,
+				   const u8 *addr, unsigned int tid)
+{
+	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+	struct ieee80211_local *local = sdata->local;
+	struct sta_info *sta;
+
+	rcu_read_lock();
+	sta = sta_info_get_bss(sdata, addr);
+	if (!sta)
+		goto unlock;
+
+	set_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired);
+	ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
+
+ unlock:
+	rcu_read_unlock();
+}
+EXPORT_SYMBOL(ieee80211_rx_ba_timer_expired);