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>
diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c
index 250b9a5..3cef5a7 100644
--- a/net/mac80211/agg-tx.c
+++ b/net/mac80211/agg-tx.c
@@ -104,8 +104,9 @@
 	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 @@
 	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)