static bool ieee80211_xmit_fast(struct ieee80211_sub_if_data *sdata,
				struct sta_info *sta,
				struct ieee80211_fast_tx *fast_tx,
				struct sk_buff *skb)
{
	struct ieee80211_local *local = sdata->local;
	u16 ethertype = (skb->data[12] << 8) | skb->data[13];
	int extra_head = fast_tx->hdr_len - (ETH_HLEN - 2);
	int hw_headroom = sdata->local->hw.extra_tx_headroom;
	struct ethhdr eth;
	struct ieee80211_tx_info *info;
	struct ieee80211_hdr *hdr = (void *)fast_tx->hdr;
	struct ieee80211_tx_data tx;
	ieee80211_tx_result r;
	struct tid_ampdu_tx *tid_tx = NULL;
	u8 tid = IEEE80211_NUM_TIDS;

	/* control port protocol needs a lot of special handling */
	if (cpu_to_be16(ethertype) == sdata->control_port_protocol)
		return false;

	/* only RFC 1042 SNAP */
	if (ethertype < ETH_P_802_3_MIN)
		return false;

	/* don't handle TX status request here either */
	if (skb->sk && skb_shinfo(skb)->tx_flags & SKBTX_WIFI_STATUS)
		return false;

	if (hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_QOS_DATA)) {
		tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
		tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
		if (tid_tx) {
			if (!test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state))
				return false;
			if (tid_tx->timeout)
				tid_tx->last_tx = jiffies;
		}
	}

	/* after this point (skb is modified) we cannot return false */

	if (skb_shared(skb)) {
		struct sk_buff *tmp_skb = skb;

		skb = skb_clone(skb, GFP_ATOMIC);
		kfree_skb(tmp_skb);

		if (!skb)
			return true;
	}

	if ((hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_QOS_DATA)) &&
	    ieee80211_amsdu_aggregate(sdata, sta, fast_tx, skb))
		return true;

	/* will not be crypto-handled beyond what we do here, so use false
	 * as the may-encrypt argument for the resize to not account for
	 * more room than we already have in 'extra_head'
	 */
	if (unlikely(ieee80211_skb_resize(sdata, skb,
					  max_t(int, extra_head + hw_headroom -
						     skb_headroom(skb), 0),
					  ENCRYPT_NO))) {
		kfree_skb(skb);
		return true;
	}

	memcpy(&eth, skb->data, ETH_HLEN - 2);
	hdr = skb_push(skb, extra_head);
	memcpy(skb->data, fast_tx->hdr, fast_tx->hdr_len);
	memcpy(skb->data + fast_tx->da_offs, eth.h_dest, ETH_ALEN);
	memcpy(skb->data + fast_tx->sa_offs, eth.h_source, ETH_ALEN);

	info = IEEE80211_SKB_CB(skb);
	memset(info, 0, sizeof(*info));
	info->band = fast_tx->band;
	info->control.vif = &sdata->vif;
	info->flags = IEEE80211_TX_CTL_FIRST_FRAGMENT |
		      IEEE80211_TX_CTL_DONTFRAG |
		      (tid_tx ? IEEE80211_TX_CTL_AMPDU : 0);
	info->control.flags = IEEE80211_TX_CTRL_FAST_XMIT;

#ifdef CONFIG_MAC80211_DEBUGFS
	if (local->force_tx_status)
		info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
#endif

	if (hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_QOS_DATA)) {
		tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
		*ieee80211_get_qos_ctl(hdr) = tid;
	}

	__skb_queue_head_init(&tx.skbs);

	tx.flags = IEEE80211_TX_UNICAST;
	tx.local = local;
	tx.sdata = sdata;
	tx.sta = sta;
	tx.key = fast_tx->key;

	if (!ieee80211_hw_check(&local->hw, HAS_RATE_CONTROL)) {
		tx.skb = skb;
		r = ieee80211_tx_h_rate_ctrl(&tx);
		skb = tx.skb;
		tx.skb = NULL;

		if (r != TX_CONTINUE) {
			if (r != TX_QUEUED)
				kfree_skb(skb);
			return true;
		}
	}

	if (ieee80211_queue_skb(local, sdata, sta, skb))
		return true;

	ieee80211_xmit_fast_finish(sdata, sta, fast_tx->pn_offs,
				   fast_tx->key, skb);

	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
		sdata = container_of(sdata->bss,
				     struct ieee80211_sub_if_data, u.ap);

	__skb_queue_tail(&tx.skbs, skb);
	ieee80211_tx_frags(local, &sdata->vif, sta, &tx.skbs, false);
	return true;
}