static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx,
				       struct sk_buff_head *frames)
{
	struct sk_buff *skb = rx->skb;
	struct ieee80211_local *local = rx->local;
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
	struct sta_info *sta = rx->sta;
	struct tid_ampdu_rx *tid_agg_rx;
	u16 sc;
	u8 tid, ack_policy;

	if (!ieee80211_is_data_qos(hdr->frame_control) ||
	    is_multicast_ether_addr(hdr->addr1))
		goto dont_reorder;

	/*
	 * filter the QoS data rx stream according to
	 * STA/TID and check if this STA/TID is on aggregation
	 */

	if (!sta)
		goto dont_reorder;

	ack_policy = *ieee80211_get_qos_ctl(hdr) &
		     IEEE80211_QOS_CTL_ACK_POLICY_MASK;
	tid = ieee80211_get_tid(hdr);

	tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
	if (!tid_agg_rx) {
		if (ack_policy == IEEE80211_QOS_CTL_ACK_POLICY_BLOCKACK &&
		    !test_bit(tid, rx->sta->ampdu_mlme.agg_session_valid) &&
		    !test_and_set_bit(tid, rx->sta->ampdu_mlme.unexpected_agg))
			ieee80211_send_delba(rx->sdata, rx->sta->sta.addr, tid,
					     WLAN_BACK_RECIPIENT,
					     WLAN_REASON_QSTA_REQUIRE_SETUP);
		goto dont_reorder;
	}

	/* qos null data frames are excluded */
	if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
		goto dont_reorder;

	/* not part of a BA session */
	if (ack_policy != IEEE80211_QOS_CTL_ACK_POLICY_BLOCKACK &&
	    ack_policy != IEEE80211_QOS_CTL_ACK_POLICY_NORMAL)
		goto dont_reorder;

	/* new, potentially un-ordered, ampdu frame - process it */

	/* reset session timer */
	if (tid_agg_rx->timeout)
		tid_agg_rx->last_rx = jiffies;

	/* if this mpdu is fragmented - terminate rx aggregation session */
	sc = le16_to_cpu(hdr->seq_ctrl);
	if (sc & IEEE80211_SCTL_FRAG) {
		skb_queue_tail(&rx->sdata->skb_queue, skb);
		ieee80211_queue_work(&local->hw, &rx->sdata->work);
		return;
	}

	/*
	 * No locking needed -- we will only ever process one
	 * RX packet at a time, and thus own tid_agg_rx. All
	 * other code manipulating it needs to (and does) make
	 * sure that we cannot get to it any more before doing
	 * anything with it.
	 */
	if (ieee80211_sta_manage_reorder_buf(rx->sdata, tid_agg_rx, skb,
					     frames))
		return;

 dont_reorder:
	__skb_queue_tail(frames, skb);
}
Unknown