+static void ieee80211_send_4addr_nullfunc(struct ieee80211_local *local,
+ struct ieee80211_sub_if_data *sdata)
+{
+ struct sk_buff *skb;
+ struct ieee80211_hdr *nullfunc;
+ __le16 fc;
+
+ if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_STATION))
+ return;
+
+ skb = dev_alloc_skb(local->hw.extra_tx_headroom + 30);
+ if (!skb) {
+ printk(KERN_DEBUG "%s: failed to allocate buffer for 4addr "
+ "nullfunc frame\n", sdata->name);
+ return;
+ }
+ skb_reserve(skb, local->hw.extra_tx_headroom);
+
+ nullfunc = (struct ieee80211_hdr *) skb_put(skb, 30);
+ memset(nullfunc, 0, 30);
+ fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_NULLFUNC |
+ IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
+ nullfunc->frame_control = fc;
+ memcpy(nullfunc->addr1, sdata->u.mgd.bssid, ETH_ALEN);
+ memcpy(nullfunc->addr2, sdata->vif.addr, ETH_ALEN);
+ memcpy(nullfunc->addr3, sdata->u.mgd.bssid, ETH_ALEN);
+ memcpy(nullfunc->addr4, sdata->vif.addr, ETH_ALEN);
+
+ IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
+ ieee80211_tx_skb(sdata, skb);
+}
+