mac80211: make ieee80211_send_bar available for drivers

To properly maintain the peer's block ack window, the driver needs to be
able to control the new starting sequence number that is sent along with
the BlockAckReq frame.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

include/net/mac80211.h

@@ -3225,6 +3225,19 @@ void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw);
 void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap,
 				  const u8 *addr);
 
+/**
+ * ieee80211_send_bar - send a BlockAckReq frame
+ *
+ * can be used to flush pending frames from the peer's aggregation reorder
+ * buffer.
+ *
+ * @vif: &struct ieee80211_vif pointer from the add_interface callback.
+ * @ra: the peer's destination address
+ * @tid: the TID of the aggregation session
+ * @ssn: the new starting sequence number for the receiver
+ */
+void ieee80211_send_bar(struct ieee80211_vif *vif, u8 *ra, u16 tid, u16 ssn);
+
 /* Rate control API */
 
 /**

net/mac80211/agg-tx.c

@@ -104,8 +104,9 @@ static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata,
 	ieee80211_tx_skb(sdata, skb);
 }
 
-void ieee80211_send_bar(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid, u16 ssn)
+void ieee80211_send_bar(struct ieee80211_vif *vif, u8 *ra, u16 tid, u16 ssn)
 {
+	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 	struct ieee80211_local *local = sdata->local;
 	struct sk_buff *skb;
 	struct ieee80211_bar *bar;
@@ -131,6 +132,7 @@ void ieee80211_send_bar(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid, u1
 	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
 	ieee80211_tx_skb(sdata, skb);
 }
+EXPORT_SYMBOL(ieee80211_send_bar);
 
 void ieee80211_assign_tid_tx(struct sta_info *sta, int tid,
 			     struct tid_ampdu_tx *tid_tx)

net/mac80211/ieee80211_i.h

@@ -1186,7 +1186,6 @@ struct ieee80211_tx_status_rtap_hdr {
 void ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_supported_band *sband,
 				       struct ieee80211_ht_cap *ht_cap_ie,
 				       struct ieee80211_sta_ht_cap *ht_cap);
-void ieee80211_send_bar(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid, u16 ssn);
 void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
 			  const u8 *da, u16 tid,
 			  u16 initiator, u16 reason_code);

net/mac80211/status.c

@@ -136,7 +136,7 @@ static void ieee80211_check_pending_bar(struct sta_info *sta, u8 *addr, u8 tid)
 		return;
 
 	tid_tx->bar_pending = false;
-	ieee80211_send_bar(sta->sdata, addr, tid, tid_tx->failed_bar_ssn);
+	ieee80211_send_bar(&sta->sdata->vif, addr, tid, tid_tx->failed_bar_ssn);
 }
 
 static void ieee80211_frame_acked(struct sta_info *sta, struct sk_buff *skb)
@@ -273,7 +273,7 @@ void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
 			tid = qc[0] & 0xf;
 			ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10)
 						& IEEE80211_SCTL_SEQ);
-			ieee80211_send_bar(sta->sdata, hdr->addr1,
+			ieee80211_send_bar(&sta->sdata->vif, hdr->addr1,
 					   tid, ssn);
 		}