/*
   * Copyright 2002-2005, Instant802 Networks, Inc.
   * Copyright 2005-2006, Devicescape Software, Inc.
   * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
   * Copyright 2007	Johannes Berg <johannes@sipsolutions.net>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   *
   * utilities for mac80211
   */
  
  #include <net/mac80211.h>
  #include <linux/netdevice.h>

  #include <linux/export.h>

  #include <linux/types.h>
  #include <linux/slab.h>
  #include <linux/skbuff.h>
  #include <linux/etherdevice.h>
  #include <linux/if_arp.h>

  #include <linux/bitmap.h>

  #include <linux/crc32.h>

  #include <net/net_namespace.h>

  #include <net/cfg80211.h>

  #include <net/rtnetlink.h>

  
  #include "ieee80211_i.h"

  #include "driver-ops.h"

  #include "rate.h"

  #include "mesh.h"

  #include "wme.h"

  #include "led.h"

  #include "wep.h"

  
  /* privid for wiphys to determine whether they belong to us or not */
  void *mac80211_wiphy_privid = &mac80211_wiphy_privid;

  struct ieee80211_hw *wiphy_to_ieee80211_hw(struct wiphy *wiphy)
  {
  	struct ieee80211_local *local;
  	BUG_ON(!wiphy);
  
  	local = wiphy_priv(wiphy);
  	return &local->hw;
  }
  EXPORT_SYMBOL(wiphy_to_ieee80211_hw);

  u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len,

  			enum nl80211_iftype type)

  {

  	__le16 fc = hdr->frame_control;

  	 /* drop ACK/CTS frames and incorrect hdr len (ctrl) */
  	if (len < 16)

  		return NULL;

  	if (ieee80211_is_data(fc)) {

  		if (len < 24) /* drop incorrect hdr len (data) */
  			return NULL;

  
  		if (ieee80211_has_a4(fc))

  			return NULL;

  		if (ieee80211_has_tods(fc))
  			return hdr->addr1;
  		if (ieee80211_has_fromds(fc))

  			return hdr->addr2;

  
  		return hdr->addr3;
  	}
  
  	if (ieee80211_is_mgmt(fc)) {

  		if (len < 24) /* drop incorrect hdr len (mgmt) */
  			return NULL;

  		return hdr->addr3;

  	}
  
  	if (ieee80211_is_ctl(fc)) {
  		if(ieee80211_is_pspoll(fc))

  			return hdr->addr1;

  
  		if (ieee80211_is_back_req(fc)) {

  			switch (type) {

  			case NL80211_IFTYPE_STATION:

  				return hdr->addr2;

  			case NL80211_IFTYPE_AP:
  			case NL80211_IFTYPE_AP_VLAN:

  				return hdr->addr1;
  			default:

  				break; /* fall through to the return */

  			}
  		}

  	}
  
  	return NULL;
  }

  void ieee80211_tx_set_protected(struct ieee80211_tx_data *tx)

  {

  	struct sk_buff *skb;

  	struct ieee80211_hdr *hdr;

  	skb_queue_walk(&tx->skbs, skb) {

  		hdr = (struct ieee80211_hdr *) skb->data;
  		hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);

  	}

  }
  
  int ieee80211_frame_duration(struct ieee80211_local *local, size_t len,
  			     int rate, int erp, int short_preamble)
  {
  	int dur;
  
  	/* calculate duration (in microseconds, rounded up to next higher
  	 * integer if it includes a fractional microsecond) to send frame of
  	 * len bytes (does not include FCS) at the given rate. Duration will
  	 * also include SIFS.
  	 *
  	 * rate is in 100 kbps, so divident is multiplied by 10 in the
  	 * DIV_ROUND_UP() operations.
  	 */

  	if (local->hw.conf.channel->band == IEEE80211_BAND_5GHZ || erp) {

  		/*
  		 * OFDM:
  		 *
  		 * N_DBPS = DATARATE x 4
  		 * N_SYM = Ceiling((16+8xLENGTH+6) / N_DBPS)
  		 *	(16 = SIGNAL time, 6 = tail bits)
  		 * TXTIME = T_PREAMBLE + T_SIGNAL + T_SYM x N_SYM + Signal Ext
  		 *
  		 * T_SYM = 4 usec
  		 * 802.11a - 17.5.2: aSIFSTime = 16 usec
  		 * 802.11g - 19.8.4: aSIFSTime = 10 usec +
  		 *	signal ext = 6 usec
  		 */

  		dur = 16; /* SIFS + signal ext */
  		dur += 16; /* 17.3.2.3: T_PREAMBLE = 16 usec */
  		dur += 4; /* 17.3.2.3: T_SIGNAL = 4 usec */
  		dur += 4 * DIV_ROUND_UP((16 + 8 * (len + 4) + 6) * 10,
  					4 * rate); /* T_SYM x N_SYM */
  	} else {
  		/*
  		 * 802.11b or 802.11g with 802.11b compatibility:
  		 * 18.3.4: TXTIME = PreambleLength + PLCPHeaderTime +
  		 * Ceiling(((LENGTH+PBCC)x8)/DATARATE). PBCC=0.
  		 *
  		 * 802.11 (DS): 15.3.3, 802.11b: 18.3.4
  		 * aSIFSTime = 10 usec
  		 * aPreambleLength = 144 usec or 72 usec with short preamble
  		 * aPLCPHeaderLength = 48 usec or 24 usec with short preamble
  		 */
  		dur = 10; /* aSIFSTime = 10 usec */
  		dur += short_preamble ? (72 + 24) : (144 + 48);
  
  		dur += DIV_ROUND_UP(8 * (len + 4) * 10, rate);
  	}
  
  	return dur;
  }
  
  /* Exported duration function for driver use */

  __le16 ieee80211_generic_frame_duration(struct ieee80211_hw *hw,
  					struct ieee80211_vif *vif,

  					size_t frame_len,
  					struct ieee80211_rate *rate)

  {
  	struct ieee80211_local *local = hw_to_local(hw);

  	struct ieee80211_sub_if_data *sdata;

  	u16 dur;
  	int erp;

  	bool short_preamble = false;

  	erp = 0;

  	if (vif) {
  		sdata = vif_to_sdata(vif);

  		short_preamble = sdata->vif.bss_conf.use_short_preamble;

  		if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
  			erp = rate->flags & IEEE80211_RATE_ERP_G;
  	}

  
  	dur = ieee80211_frame_duration(local, frame_len, rate->bitrate, erp,

  				       short_preamble);

  
  	return cpu_to_le16(dur);
  }
  EXPORT_SYMBOL(ieee80211_generic_frame_duration);

  __le16 ieee80211_rts_duration(struct ieee80211_hw *hw,
  			      struct ieee80211_vif *vif, size_t frame_len,

  			      const struct ieee80211_tx_info *frame_txctl)

  {
  	struct ieee80211_local *local = hw_to_local(hw);
  	struct ieee80211_rate *rate;

  	struct ieee80211_sub_if_data *sdata;

  	bool short_preamble;

  	int erp;
  	u16 dur;

  	struct ieee80211_supported_band *sband;
  
  	sband = local->hw.wiphy->bands[local->hw.conf.channel->band];

  	short_preamble = false;

  	rate = &sband->bitrates[frame_txctl->control.rts_cts_rate_idx];

  
  	erp = 0;

  	if (vif) {
  		sdata = vif_to_sdata(vif);

  		short_preamble = sdata->vif.bss_conf.use_short_preamble;

  		if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
  			erp = rate->flags & IEEE80211_RATE_ERP_G;
  	}

  
  	/* CTS duration */

  	dur = ieee80211_frame_duration(local, 10, rate->bitrate,

  				       erp, short_preamble);
  	/* Data frame duration */

  	dur += ieee80211_frame_duration(local, frame_len, rate->bitrate,

  					erp, short_preamble);
  	/* ACK duration */

  	dur += ieee80211_frame_duration(local, 10, rate->bitrate,

  					erp, short_preamble);
  
  	return cpu_to_le16(dur);
  }
  EXPORT_SYMBOL(ieee80211_rts_duration);

  __le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw,
  				    struct ieee80211_vif *vif,

  				    size_t frame_len,

  				    const struct ieee80211_tx_info *frame_txctl)

  {
  	struct ieee80211_local *local = hw_to_local(hw);
  	struct ieee80211_rate *rate;

  	struct ieee80211_sub_if_data *sdata;

  	bool short_preamble;

  	int erp;
  	u16 dur;

  	struct ieee80211_supported_band *sband;
  
  	sband = local->hw.wiphy->bands[local->hw.conf.channel->band];

  	short_preamble = false;

  	rate = &sband->bitrates[frame_txctl->control.rts_cts_rate_idx];

  	erp = 0;

  	if (vif) {
  		sdata = vif_to_sdata(vif);

  		short_preamble = sdata->vif.bss_conf.use_short_preamble;

  		if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
  			erp = rate->flags & IEEE80211_RATE_ERP_G;
  	}

  
  	/* Data frame duration */

  	dur = ieee80211_frame_duration(local, frame_len, rate->bitrate,

  				       erp, short_preamble);

  	if (!(frame_txctl->flags & IEEE80211_TX_CTL_NO_ACK)) {

  		/* ACK duration */

  		dur += ieee80211_frame_duration(local, 10, rate->bitrate,

  						erp, short_preamble);
  	}
  
  	return cpu_to_le16(dur);
  }
  EXPORT_SYMBOL(ieee80211_ctstoself_duration);

  static void __ieee80211_wake_queue(struct ieee80211_hw *hw, int queue,
  				   enum queue_stop_reason reason)

  {
  	struct ieee80211_local *local = hw_to_local(hw);

  	struct ieee80211_sub_if_data *sdata;

  	trace_wake_queue(local, queue, reason);

  	if (WARN_ON(queue >= hw->queues))
  		return;

  	__clear_bit(reason, &local->queue_stop_reasons[queue]);
  
  	if (local->queue_stop_reasons[queue] != 0)
  		/* someone still has this queue stopped */
  		return;

  	if (skb_queue_empty(&local->pending[queue])) {
  		rcu_read_lock();

  		list_for_each_entry_rcu(sdata, &local->interfaces, list) {
  			if (test_bit(SDATA_STATE_OFFCHANNEL, &sdata->state))
  				continue;

  			netif_wake_subqueue(sdata->dev, queue);

  		}

  		rcu_read_unlock();
  	} else

  		tasklet_schedule(&local->tx_pending_tasklet);

  }

  void ieee80211_wake_queue_by_reason(struct ieee80211_hw *hw, int queue,
  				    enum queue_stop_reason reason)

  {
  	struct ieee80211_local *local = hw_to_local(hw);
  	unsigned long flags;
  
  	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
  	__ieee80211_wake_queue(hw, queue, reason);
  	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
  }
  
  void ieee80211_wake_queue(struct ieee80211_hw *hw, int queue)
  {
  	ieee80211_wake_queue_by_reason(hw, queue,
  				       IEEE80211_QUEUE_STOP_REASON_DRIVER);
  }

  EXPORT_SYMBOL(ieee80211_wake_queue);

  static void __ieee80211_stop_queue(struct ieee80211_hw *hw, int queue,
  				   enum queue_stop_reason reason)

  {
  	struct ieee80211_local *local = hw_to_local(hw);

  	struct ieee80211_sub_if_data *sdata;

  	trace_stop_queue(local, queue, reason);

  	if (WARN_ON(queue >= hw->queues))
  		return;

  	__set_bit(reason, &local->queue_stop_reasons[queue]);

  
  	rcu_read_lock();
  	list_for_each_entry_rcu(sdata, &local->interfaces, list)

  		netif_stop_subqueue(sdata->dev, queue);

  	rcu_read_unlock();

  }

  void ieee80211_stop_queue_by_reason(struct ieee80211_hw *hw, int queue,
  				    enum queue_stop_reason reason)

  {
  	struct ieee80211_local *local = hw_to_local(hw);
  	unsigned long flags;
  
  	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
  	__ieee80211_stop_queue(hw, queue, reason);
  	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
  }
  
  void ieee80211_stop_queue(struct ieee80211_hw *hw, int queue)
  {
  	ieee80211_stop_queue_by_reason(hw, queue,
  				       IEEE80211_QUEUE_STOP_REASON_DRIVER);
  }

  EXPORT_SYMBOL(ieee80211_stop_queue);

  void ieee80211_add_pending_skb(struct ieee80211_local *local,
  			       struct sk_buff *skb)
  {
  	struct ieee80211_hw *hw = &local->hw;
  	unsigned long flags;
  	int queue = skb_get_queue_mapping(skb);

  	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
  
  	if (WARN_ON(!info->control.vif)) {

  		kfree_skb(skb);

  		return;
  	}

  
  	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
  	__ieee80211_stop_queue(hw, queue, IEEE80211_QUEUE_STOP_REASON_SKB_ADD);

  	__skb_queue_tail(&local->pending[queue], skb);

  	__ieee80211_wake_queue(hw, queue, IEEE80211_QUEUE_STOP_REASON_SKB_ADD);
  	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
  }

  void ieee80211_add_pending_skbs_fn(struct ieee80211_local *local,
  				   struct sk_buff_head *skbs,
  				   void (*fn)(void *data), void *data)

  {
  	struct ieee80211_hw *hw = &local->hw;
  	struct sk_buff *skb;
  	unsigned long flags;

  	int queue, i;

  
  	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
  	for (i = 0; i < hw->queues; i++)
  		__ieee80211_stop_queue(hw, i,
  			IEEE80211_QUEUE_STOP_REASON_SKB_ADD);
  
  	while ((skb = skb_dequeue(skbs))) {

  		struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
  
  		if (WARN_ON(!info->control.vif)) {

  			kfree_skb(skb);

  			continue;
  		}

  		queue = skb_get_queue_mapping(skb);

  		__skb_queue_tail(&local->pending[queue], skb);

  	}

  	if (fn)
  		fn(data);

  	for (i = 0; i < hw->queues; i++)

  		__ieee80211_wake_queue(hw, i,
  			IEEE80211_QUEUE_STOP_REASON_SKB_ADD);

  	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);

  }

  void ieee80211_add_pending_skbs(struct ieee80211_local *local,
  				struct sk_buff_head *skbs)

  {

  	ieee80211_add_pending_skbs_fn(local, skbs, NULL, NULL);

  }

  void ieee80211_stop_queues_by_reason(struct ieee80211_hw *hw,
  				    enum queue_stop_reason reason)

  {

  	struct ieee80211_local *local = hw_to_local(hw);
  	unsigned long flags;

  	int i;

  	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);

  	for (i = 0; i < hw->queues; i++)

  		__ieee80211_stop_queue(hw, i, reason);
  
  	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
  }
  
  void ieee80211_stop_queues(struct ieee80211_hw *hw)
  {
  	ieee80211_stop_queues_by_reason(hw,
  					IEEE80211_QUEUE_STOP_REASON_DRIVER);

  }
  EXPORT_SYMBOL(ieee80211_stop_queues);

  int ieee80211_queue_stopped(struct ieee80211_hw *hw, int queue)
  {
  	struct ieee80211_local *local = hw_to_local(hw);

  	unsigned long flags;
  	int ret;

  	if (WARN_ON(queue >= hw->queues))
  		return true;

  	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
  	ret = !!local->queue_stop_reasons[queue];
  	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
  	return ret;

  }
  EXPORT_SYMBOL(ieee80211_queue_stopped);

  void ieee80211_wake_queues_by_reason(struct ieee80211_hw *hw,
  				     enum queue_stop_reason reason)

  {

  	struct ieee80211_local *local = hw_to_local(hw);
  	unsigned long flags;

  	int i;

  	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);

  	for (i = 0; i < hw->queues; i++)

  		__ieee80211_wake_queue(hw, i, reason);
  
  	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
  }
  
  void ieee80211_wake_queues(struct ieee80211_hw *hw)
  {
  	ieee80211_wake_queues_by_reason(hw, IEEE80211_QUEUE_STOP_REASON_DRIVER);

  }
  EXPORT_SYMBOL(ieee80211_wake_queues);

  void ieee80211_iterate_active_interfaces(
  	struct ieee80211_hw *hw,
  	void (*iterator)(void *data, u8 *mac,
  			 struct ieee80211_vif *vif),
  	void *data)

  {
  	struct ieee80211_local *local = hw_to_local(hw);
  	struct ieee80211_sub_if_data *sdata;

  	mutex_lock(&local->iflist_mtx);

  
  	list_for_each_entry(sdata, &local->interfaces, list) {
  		switch (sdata->vif.type) {

  		case NL80211_IFTYPE_MONITOR:
  		case NL80211_IFTYPE_AP_VLAN:

  			continue;

  		default:

  			break;
  		}

  		if (ieee80211_sdata_running(sdata))

  			iterator(data, sdata->vif.addr,

  				 &sdata->vif);
  	}

  	mutex_unlock(&local->iflist_mtx);

  }
  EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces);
  
  void ieee80211_iterate_active_interfaces_atomic(
  	struct ieee80211_hw *hw,
  	void (*iterator)(void *data, u8 *mac,
  			 struct ieee80211_vif *vif),
  	void *data)
  {
  	struct ieee80211_local *local = hw_to_local(hw);
  	struct ieee80211_sub_if_data *sdata;

  	rcu_read_lock();

  	list_for_each_entry_rcu(sdata, &local->interfaces, list) {

  		switch (sdata->vif.type) {

  		case NL80211_IFTYPE_MONITOR:
  		case NL80211_IFTYPE_AP_VLAN:

  			continue;

  		default:

  			break;
  		}

  		if (ieee80211_sdata_running(sdata))

  			iterator(data, sdata->vif.addr,

  				 &sdata->vif);

  	}

  
  	rcu_read_unlock();

  }

  EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces_atomic);

  /*
   * Nothing should have been stuffed into the workqueue during
   * the suspend->resume cycle. If this WARN is seen then there
   * is a bug with either the driver suspend or something in
   * mac80211 stuffing into the workqueue which we haven't yet
   * cleared during mac80211's suspend cycle.
   */
  static bool ieee80211_can_queue_work(struct ieee80211_local *local)
  {

  	if (WARN(local->suspended && !local->resuming,
  		 "queueing ieee80211 work while going to suspend
  "))
  		return false;

  
  	return true;
  }
  
  void ieee80211_queue_work(struct ieee80211_hw *hw, struct work_struct *work)
  {
  	struct ieee80211_local *local = hw_to_local(hw);
  
  	if (!ieee80211_can_queue_work(local))
  		return;
  
  	queue_work(local->workqueue, work);
  }
  EXPORT_SYMBOL(ieee80211_queue_work);
  
  void ieee80211_queue_delayed_work(struct ieee80211_hw *hw,
  				  struct delayed_work *dwork,
  				  unsigned long delay)
  {
  	struct ieee80211_local *local = hw_to_local(hw);
  
  	if (!ieee80211_can_queue_work(local))
  		return;
  
  	queue_delayed_work(local->workqueue, dwork, delay);
  }
  EXPORT_SYMBOL(ieee80211_queue_delayed_work);

  u32 ieee802_11_parse_elems_crc(u8 *start, size_t len,
  			       struct ieee802_11_elems *elems,
  			       u64 filter, u32 crc)
  {
  	size_t left = len;
  	u8 *pos = start;
  	bool calc_crc = filter != 0;
  
  	memset(elems, 0, sizeof(*elems));
  	elems->ie_start = start;
  	elems->total_len = len;
  
  	while (left >= 2) {
  		u8 id, elen;
  
  		id = *pos++;
  		elen = *pos++;
  		left -= 2;
  
  		if (elen > left)
  			break;
  
  		if (calc_crc && id < 64 && (filter & (1ULL << id)))
  			crc = crc32_be(crc, pos - 2, elen + 2);
  
  		switch (id) {
  		case WLAN_EID_SSID:
  			elems->ssid = pos;
  			elems->ssid_len = elen;
  			break;
  		case WLAN_EID_SUPP_RATES:
  			elems->supp_rates = pos;
  			elems->supp_rates_len = elen;
  			break;
  		case WLAN_EID_FH_PARAMS:
  			elems->fh_params = pos;
  			elems->fh_params_len = elen;
  			break;
  		case WLAN_EID_DS_PARAMS:
  			elems->ds_params = pos;
  			elems->ds_params_len = elen;
  			break;
  		case WLAN_EID_CF_PARAMS:
  			elems->cf_params = pos;
  			elems->cf_params_len = elen;
  			break;
  		case WLAN_EID_TIM:
  			if (elen >= sizeof(struct ieee80211_tim_ie)) {
  				elems->tim = (void *)pos;
  				elems->tim_len = elen;
  			}
  			break;
  		case WLAN_EID_IBSS_PARAMS:
  			elems->ibss_params = pos;
  			elems->ibss_params_len = elen;
  			break;
  		case WLAN_EID_CHALLENGE:
  			elems->challenge = pos;
  			elems->challenge_len = elen;
  			break;
  		case WLAN_EID_VENDOR_SPECIFIC:
  			if (elen >= 4 && pos[0] == 0x00 && pos[1] == 0x50 &&
  			    pos[2] == 0xf2) {
  				/* Microsoft OUI (00:50:F2) */
  
  				if (calc_crc)
  					crc = crc32_be(crc, pos - 2, elen + 2);
  
  				if (pos[3] == 1) {
  					/* OUI Type 1 - WPA IE */
  					elems->wpa = pos;
  					elems->wpa_len = elen;
  				} else if (elen >= 5 && pos[3] == 2) {
  					/* OUI Type 2 - WMM IE */
  					if (pos[4] == 0) {
  						elems->wmm_info = pos;
  						elems->wmm_info_len = elen;
  					} else if (pos[4] == 1) {
  						elems->wmm_param = pos;
  						elems->wmm_param_len = elen;
  					}
  				}
  			}
  			break;
  		case WLAN_EID_RSN:
  			elems->rsn = pos;
  			elems->rsn_len = elen;
  			break;
  		case WLAN_EID_ERP_INFO:
  			elems->erp_info = pos;
  			elems->erp_info_len = elen;
  			break;
  		case WLAN_EID_EXT_SUPP_RATES:
  			elems->ext_supp_rates = pos;
  			elems->ext_supp_rates_len = elen;
  			break;
  		case WLAN_EID_HT_CAPABILITY:
  			if (elen >= sizeof(struct ieee80211_ht_cap))
  				elems->ht_cap_elem = (void *)pos;
  			break;
  		case WLAN_EID_HT_INFORMATION:
  			if (elen >= sizeof(struct ieee80211_ht_info))
  				elems->ht_info_elem = (void *)pos;
  			break;
  		case WLAN_EID_MESH_ID:
  			elems->mesh_id = pos;
  			elems->mesh_id_len = elen;
  			break;
  		case WLAN_EID_MESH_CONFIG:
  			if (elen >= sizeof(struct ieee80211_meshconf_ie))
  				elems->mesh_config = (void *)pos;
  			break;
  		case WLAN_EID_PEER_MGMT:
  			elems->peering = pos;
  			elems->peering_len = elen;
  			break;
  		case WLAN_EID_PREQ:
  			elems->preq = pos;
  			elems->preq_len = elen;
  			break;
  		case WLAN_EID_PREP:
  			elems->prep = pos;
  			elems->prep_len = elen;
  			break;
  		case WLAN_EID_PERR:
  			elems->perr = pos;
  			elems->perr_len = elen;
  			break;
  		case WLAN_EID_RANN:
  			if (elen >= sizeof(struct ieee80211_rann_ie))
  				elems->rann = (void *)pos;
  			break;
  		case WLAN_EID_CHANNEL_SWITCH:
  			elems->ch_switch_elem = pos;
  			elems->ch_switch_elem_len = elen;
  			break;
  		case WLAN_EID_QUIET:
  			if (!elems->quiet_elem) {
  				elems->quiet_elem = pos;
  				elems->quiet_elem_len = elen;
  			}
  			elems->num_of_quiet_elem++;
  			break;
  		case WLAN_EID_COUNTRY:
  			elems->country_elem = pos;
  			elems->country_elem_len = elen;
  			break;
  		case WLAN_EID_PWR_CONSTRAINT:
  			elems->pwr_constr_elem = pos;
  			elems->pwr_constr_elem_len = elen;
  			break;
  		case WLAN_EID_TIMEOUT_INTERVAL:
  			elems->timeout_int = pos;
  			elems->timeout_int_len = elen;
  			break;
  		default:
  			break;
  		}
  
  		left -= elen;
  		pos += elen;
  	}
  
  	return crc;
  }

  void ieee802_11_parse_elems(u8 *start, size_t len,
  			    struct ieee802_11_elems *elems)
  {

  	ieee802_11_parse_elems_crc(start, len, elems, 0, 0);
  }

  void ieee80211_set_wmm_default(struct ieee80211_sub_if_data *sdata)
  {
  	struct ieee80211_local *local = sdata->local;
  	struct ieee80211_tx_queue_params qparam;

  	int queue;
  	bool use_11b;
  	int aCWmin, aCWmax;

  
  	if (!local->ops->conf_tx)
  		return;
  
  	memset(&qparam, 0, sizeof(qparam));

  	use_11b = (local->hw.conf.channel->band == IEEE80211_BAND_2GHZ) &&
  		 !(sdata->flags & IEEE80211_SDATA_OPERATING_GMODE);

  	for (queue = 0; queue < local_to_hw(local)->queues; queue++) {
  		/* Set defaults according to 802.11-2007 Table 7-37 */
  		aCWmax = 1023;
  		if (use_11b)
  			aCWmin = 31;
  		else
  			aCWmin = 15;
  
  		switch (queue) {
  		case 3: /* AC_BK */

  			qparam.cw_max = aCWmax;
  			qparam.cw_min = aCWmin;

  			qparam.txop = 0;
  			qparam.aifs = 7;
  			break;
  		default: /* never happens but let's not leave undefined */
  		case 2: /* AC_BE */

  			qparam.cw_max = aCWmax;
  			qparam.cw_min = aCWmin;

  			qparam.txop = 0;
  			qparam.aifs = 3;
  			break;
  		case 1: /* AC_VI */
  			qparam.cw_max = aCWmin;
  			qparam.cw_min = (aCWmin + 1) / 2 - 1;
  			if (use_11b)
  				qparam.txop = 6016/32;
  			else
  				qparam.txop = 3008/32;
  			qparam.aifs = 2;
  			break;
  		case 0: /* AC_VO */
  			qparam.cw_max = (aCWmin + 1) / 2 - 1;
  			qparam.cw_min = (aCWmin + 1) / 4 - 1;
  			if (use_11b)
  				qparam.txop = 3264/32;
  			else
  				qparam.txop = 1504/32;
  			qparam.aifs = 2;
  			break;
  		}

  		qparam.uapsd = false;

  		sdata->tx_conf[queue] = qparam;
  		drv_conf_tx(local, sdata, queue, &qparam);

  	}

  
  	/* after reinitialize QoS TX queues setting to default,
  	 * disable QoS at all */

  
  	if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
  		sdata->vif.bss_conf.qos =
  			sdata->vif.type != NL80211_IFTYPE_STATION;
  		ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_QOS);
  	}

  }

  void ieee80211_sta_def_wmm_params(struct ieee80211_sub_if_data *sdata,
  				  const size_t supp_rates_len,
  				  const u8 *supp_rates)
  {
  	struct ieee80211_local *local = sdata->local;
  	int i, have_higher_than_11mbit = 0;
  
  	/* cf. IEEE 802.11 9.2.12 */
  	for (i = 0; i < supp_rates_len; i++)
  		if ((supp_rates[i] & 0x7f) * 5 > 110)
  			have_higher_than_11mbit = 1;
  
  	if (local->hw.conf.channel->band == IEEE80211_BAND_2GHZ &&
  	    have_higher_than_11mbit)
  		sdata->flags |= IEEE80211_SDATA_OPERATING_GMODE;
  	else
  		sdata->flags &= ~IEEE80211_SDATA_OPERATING_GMODE;
  
  	ieee80211_set_wmm_default(sdata);
  }

  u32 ieee80211_mandatory_rates(struct ieee80211_local *local,

  			      enum ieee80211_band band)
  {
  	struct ieee80211_supported_band *sband;
  	struct ieee80211_rate *bitrates;

  	u32 mandatory_rates;

  	enum ieee80211_rate_flags mandatory_flag;
  	int i;
  
  	sband = local->hw.wiphy->bands[band];
  	if (!sband) {
  		WARN_ON(1);
  		sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
  	}
  
  	if (band == IEEE80211_BAND_2GHZ)
  		mandatory_flag = IEEE80211_RATE_MANDATORY_B;
  	else
  		mandatory_flag = IEEE80211_RATE_MANDATORY_A;
  
  	bitrates = sband->bitrates;
  	mandatory_rates = 0;
  	for (i = 0; i < sband->n_bitrates; i++)
  		if (bitrates[i].flags & mandatory_flag)
  			mandatory_rates |= BIT(i);
  	return mandatory_rates;
  }

  
  void ieee80211_send_auth(struct ieee80211_sub_if_data *sdata,
  			 u16 transaction, u16 auth_alg,

  			 u8 *extra, size_t extra_len, const u8 *bssid,
  			 const u8 *key, u8 key_len, u8 key_idx)

  {
  	struct ieee80211_local *local = sdata->local;
  	struct sk_buff *skb;
  	struct ieee80211_mgmt *mgmt;

  	int err;

  
  	skb = dev_alloc_skb(local->hw.extra_tx_headroom +

  			    sizeof(*mgmt) + 6 + extra_len);

  	if (!skb)

  		return;

  	skb_reserve(skb, local->hw.extra_tx_headroom);
  
  	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24 + 6);
  	memset(mgmt, 0, 24 + 6);
  	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
  					  IEEE80211_STYPE_AUTH);

  	memcpy(mgmt->da, bssid, ETH_ALEN);

  	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);

  	memcpy(mgmt->bssid, bssid, ETH_ALEN);
  	mgmt->u.auth.auth_alg = cpu_to_le16(auth_alg);
  	mgmt->u.auth.auth_transaction = cpu_to_le16(transaction);
  	mgmt->u.auth.status_code = cpu_to_le16(0);
  	if (extra)
  		memcpy(skb_put(skb, extra_len), extra, extra_len);

  	if (auth_alg == WLAN_AUTH_SHARED_KEY && transaction == 3) {
  		mgmt->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
  		err = ieee80211_wep_encrypt(local, skb, key, key_len, key_idx);
  		WARN_ON(err);
  	}

  	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
  	ieee80211_tx_skb(sdata, skb);

  }

  int ieee80211_build_preq_ies(struct ieee80211_local *local, u8 *buffer,

  			     const u8 *ie, size_t ie_len,

  			     enum ieee80211_band band, u32 rate_mask,
  			     u8 channel)

  {
  	struct ieee80211_supported_band *sband;

  	u8 *pos;
  	size_t offset = 0, noffset;
  	int supp_rates_len, i;

  	u8 rates[32];
  	int num_rates;
  	int ext_rates_len;

  	sband = local->hw.wiphy->bands[band];

  
  	pos = buffer;

  	num_rates = 0;
  	for (i = 0; i < sband->n_bitrates; i++) {
  		if ((BIT(i) & rate_mask) == 0)
  			continue; /* skip rate */
  		rates[num_rates++] = (u8) (sband->bitrates[i].bitrate / 5);
  	}
  
  	supp_rates_len = min_t(int, num_rates, 8);

  	*pos++ = WLAN_EID_SUPP_RATES;

  	*pos++ = supp_rates_len;

  	memcpy(pos, rates, supp_rates_len);
  	pos += supp_rates_len;

  
  	/* insert "request information" if in custom IEs */
  	if (ie && ie_len) {
  		static const u8 before_extrates[] = {
  			WLAN_EID_SSID,
  			WLAN_EID_SUPP_RATES,
  			WLAN_EID_REQUEST,
  		};
  		noffset = ieee80211_ie_split(ie, ie_len,
  					     before_extrates,
  					     ARRAY_SIZE(before_extrates),
  					     offset);
  		memcpy(pos, ie + offset, noffset - offset);
  		pos += noffset - offset;
  		offset = noffset;
  	}

  	ext_rates_len = num_rates - supp_rates_len;
  	if (ext_rates_len > 0) {

  		*pos++ = WLAN_EID_EXT_SUPP_RATES;

  		*pos++ = ext_rates_len;
  		memcpy(pos, rates + supp_rates_len, ext_rates_len);
  		pos += ext_rates_len;

  	}

  	if (channel && sband->band == IEEE80211_BAND_2GHZ) {
  		*pos++ = WLAN_EID_DS_PARAMS;
  		*pos++ = 1;
  		*pos++ = channel;
  	}

  	/* insert custom IEs that go before HT */
  	if (ie && ie_len) {
  		static const u8 before_ht[] = {
  			WLAN_EID_SSID,
  			WLAN_EID_SUPP_RATES,
  			WLAN_EID_REQUEST,
  			WLAN_EID_EXT_SUPP_RATES,
  			WLAN_EID_DS_PARAMS,
  			WLAN_EID_SUPPORTED_REGULATORY_CLASSES,
  		};
  		noffset = ieee80211_ie_split(ie, ie_len,
  					     before_ht, ARRAY_SIZE(before_ht),
  					     offset);
  		memcpy(pos, ie + offset, noffset - offset);
  		pos += noffset - offset;
  		offset = noffset;

  	}

  	if (sband->ht_cap.ht_supported)

  		pos = ieee80211_ie_build_ht_cap(pos, &sband->ht_cap,
  						sband->ht_cap.cap);

  	/*
  	 * If adding more here, adjust code in main.c
  	 * that calculates local->scan_ies_len.
  	 */

  	/* add any remaining custom IEs */
  	if (ie && ie_len) {
  		noffset = ie_len;
  		memcpy(pos, ie + offset, noffset - offset);
  		pos += noffset - offset;

  	}
  
  	return pos - buffer;
  }

  struct sk_buff *ieee80211_build_probe_req(struct ieee80211_sub_if_data *sdata,

  					  u8 *dst, u32 ratemask,

  					  const u8 *ssid, size_t ssid_len,

  					  const u8 *ie, size_t ie_len,
  					  bool directed)

  {
  	struct ieee80211_local *local = sdata->local;

  	struct sk_buff *skb;
  	struct ieee80211_mgmt *mgmt;

  	size_t buf_len;
  	u8 *buf;

  	u8 chan;

  
  	/* FIXME: come up with a proper value */
  	buf = kmalloc(200 + ie_len, GFP_KERNEL);

  	if (!buf)

  		return NULL;

  	/*
  	 * Do not send DS Channel parameter for directed probe requests
  	 * in order to maximize the chance that we get a response.  Some
  	 * badly-behaved APs don't respond when this parameter is included.
  	 */
  	if (directed)
  		chan = 0;
  	else
  		chan = ieee80211_frequency_to_channel(
  			local->hw.conf.channel->center_freq);

  	buf_len = ieee80211_build_preq_ies(local, buf, ie, ie_len,

  					   local->hw.conf.channel->band,

  					   ratemask, chan);

  
  	skb = ieee80211_probereq_get(&local->hw, &sdata->vif,
  				     ssid, ssid_len,
  				     buf, buf_len);

  	if (!skb)
  		goto out;

  	if (dst) {

  		mgmt = (struct ieee80211_mgmt *) skb->data;

  		memcpy(mgmt->da, dst, ETH_ALEN);
  		memcpy(mgmt->bssid, dst, ETH_ALEN);

  	}

  	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;

  
   out:

  	kfree(buf);

  
  	return skb;
  }
  
  void ieee80211_send_probe_req(struct ieee80211_sub_if_data *sdata, u8 *dst,
  			      const u8 *ssid, size_t ssid_len,

  			      const u8 *ie, size_t ie_len,

  			      u32 ratemask, bool directed, bool no_cck)

  {
  	struct sk_buff *skb;

  	skb = ieee80211_build_probe_req(sdata, dst, ratemask, ssid, ssid_len,
  					ie, ie_len, directed);

  	if (skb) {
  		if (no_cck)
  			IEEE80211_SKB_CB(skb)->flags |=
  				IEEE80211_TX_CTL_NO_CCK_RATE;

  		ieee80211_tx_skb(sdata, skb);

  	}

  }
  
  u32 ieee80211_sta_get_rates(struct ieee80211_local *local,
  			    struct ieee802_11_elems *elems,
  			    enum ieee80211_band band)
  {
  	struct ieee80211_supported_band *sband;
  	struct ieee80211_rate *bitrates;
  	size_t num_rates;
  	u32 supp_rates;
  	int i, j;
  	sband = local->hw.wiphy->bands[band];
  
  	if (!sband) {
  		WARN_ON(1);
  		sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
  	}
  
  	bitrates = sband->bitrates;
  	num_rates = sband->n_bitrates;
  	supp_rates = 0;
  	for (i = 0; i < elems->supp_rates_len +
  		     elems->ext_supp_rates_len; i++) {
  		u8 rate = 0;
  		int own_rate;
  		if (i < elems->supp_rates_len)
  			rate = elems->supp_rates[i];
  		else if (elems->ext_supp_rates)
  			rate = elems->ext_supp_rates
  				[i - elems->supp_rates_len];
  		own_rate = 5 * (rate & 0x7f);
  		for (j = 0; j < num_rates; j++)
  			if (bitrates[j].bitrate == own_rate)
  				supp_rates |= BIT(j);
  	}
  	return supp_rates;
  }

  void ieee80211_stop_device(struct ieee80211_local *local)
  {
  	ieee80211_led_radio(local, false);

  	ieee80211_mod_tpt_led_trig(local, 0, IEEE80211_TPT_LEDTRIG_FL_RADIO);

  
  	cancel_work_sync(&local->reconfig_filter);

  
  	flush_workqueue(local->workqueue);

  	drv_stop(local);

  }

  int ieee80211_reconfig(struct ieee80211_local *local)
  {
  	struct ieee80211_hw *hw = &local->hw;
  	struct ieee80211_sub_if_data *sdata;

  	struct sta_info *sta;

  	int res, i;

  #ifdef CONFIG_PM

  	if (local->suspended)
  		local->resuming = true;

  	if (local->wowlan) {
  		local->wowlan = false;
  		res = drv_resume(local);
  		if (res < 0) {
  			local->resuming = false;
  			return res;
  		}
  		if (res == 0)
  			goto wake_up;
  		WARN_ON(res > 1);
  		/*
  		 * res is 1, which means the driver requested
  		 * to go through a regular reset on wakeup.
  		 */
  	}
  #endif

  	/* everything else happens only if HW was up & running */
  	if (!local->open_count)
  		goto wake_up;

  	/*
  	 * Upon resume hardware can sometimes be goofy due to
  	 * various platform / driver / bus issues, so restarting
  	 * the device may at times not work immediately. Propagate
  	 * the error.
  	 */
  	res = drv_start(local);
  	if (res) {
  		WARN(local->suspended, "Hardware became unavailable "
  		     "upon resume. This could be a software issue "
  		     "prior to suspend or a hardware issue.
  ");
  		return res;

  	}

  	/* setup fragmentation threshold */
  	drv_set_frag_threshold(local, hw->wiphy->frag_threshold);
  
  	/* setup RTS threshold */
  	drv_set_rts_threshold(local, hw->wiphy->rts_threshold);
  
  	/* reset coverage class */
  	drv_set_coverage_class(local, hw->wiphy->coverage_class);

  	ieee80211_led_radio(local, true);
  	ieee80211_mod_tpt_led_trig(local,
  				   IEEE80211_TPT_LEDTRIG_FL_RADIO, 0);

  	/* add interfaces */
  	list_for_each_entry(sdata, &local->interfaces, list) {
  		if (sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
  		    sdata->vif.type != NL80211_IFTYPE_MONITOR &&

  		    ieee80211_sdata_running(sdata))

  			res = drv_add_interface(local, sdata);

  	}
  
  	/* add STAs back */

  	mutex_lock(&local->sta_mtx);
  	list_for_each_entry(sta, &local->sta_list, list) {
  		if (sta->uploaded) {

  			sdata = sta->sdata;

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

  			WARN_ON(drv_sta_add(local, sdata, &sta->sta));

  		}

  	}

  	mutex_unlock(&local->sta_mtx);

  	/* reconfigure tx conf */

  	list_for_each_entry(sdata, &local->interfaces, list) {
  		if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
  		    sdata->vif.type == NL80211_IFTYPE_MONITOR ||
  		    !ieee80211_sdata_running(sdata))
  			continue;
  
  		for (i = 0; i < hw->queues; i++)
  			drv_conf_tx(local, sdata, i, &sdata->tx_conf[i]);
  	}

  	/* reconfigure hardware */
  	ieee80211_hw_config(local, ~0);

  	ieee80211_configure_filter(local);

  
  	/* Finally also reconfigure all the BSS information */
  	list_for_each_entry(sdata, &local->interfaces, list) {

  		u32 changed;

  		if (!ieee80211_sdata_running(sdata))

  			continue;

  
  		/* common change flags for all interface types */
  		changed = BSS_CHANGED_ERP_CTS_PROT |
  			  BSS_CHANGED_ERP_PREAMBLE |
  			  BSS_CHANGED_ERP_SLOT |
  			  BSS_CHANGED_HT |
  			  BSS_CHANGED_BASIC_RATES |
  			  BSS_CHANGED_BEACON_INT |
  			  BSS_CHANGED_BSSID |

  			  BSS_CHANGED_CQM |

  			  BSS_CHANGED_QOS |
  			  BSS_CHANGED_IDLE;

  		switch (sdata->vif.type) {
  		case NL80211_IFTYPE_STATION:

  			changed |= BSS_CHANGED_ASSOC |
  				   BSS_CHANGED_ARP_FILTER;

  			mutex_lock(&sdata->u.mgd.mtx);

  			ieee80211_bss_info_change_notify(sdata, changed);

  			mutex_unlock(&sdata->u.mgd.mtx);

  			break;

  		case NL80211_IFTYPE_ADHOC:

  			changed |= BSS_CHANGED_IBSS;
  			/* fall through */

  		case NL80211_IFTYPE_AP:

  			changed |= BSS_CHANGED_SSID;
  
  			if (sdata->vif.type == NL80211_IFTYPE_AP)
  				changed |= BSS_CHANGED_AP_PROBE_RESP;

  			/* fall through */

  		case NL80211_IFTYPE_MESH_POINT:

  			changed |= BSS_CHANGED_BEACON |
  				   BSS_CHANGED_BEACON_ENABLED;

  			ieee80211_bss_info_change_notify(sdata, changed);

  			break;
  		case NL80211_IFTYPE_WDS:
  			break;
  		case NL80211_IFTYPE_AP_VLAN:
  		case NL80211_IFTYPE_MONITOR:
  			/* ignore virtual */
  			break;
  		case NL80211_IFTYPE_UNSPECIFIED:

  		case NUM_NL80211_IFTYPES:

  		case NL80211_IFTYPE_P2P_CLIENT:
  		case NL80211_IFTYPE_P2P_GO:

  			WARN_ON(1);
  			break;
  		}
  	}

  	ieee80211_recalc_ps(local, -1);

  	/*
  	 * Clear the WLAN_STA_BLOCK_BA flag so new aggregation
  	 * sessions can be established after a resume.
  	 *
  	 * Also tear down aggregation sessions since reconfiguring
  	 * them in a hardware restart scenario is not easily done
  	 * right now, and the hardware will have lost information
  	 * about the sessions, but we and the AP still think they
  	 * are active. This is really a workaround though.
  	 */

  	if (hw->flags & IEEE80211_HW_AMPDU_AGGREGATION) {

  		mutex_lock(&local->sta_mtx);
  
  		list_for_each_entry(sta, &local->sta_list, list) {

  			ieee80211_sta_tear_down_BA_sessions(sta, true);

  			clear_sta_flag(sta, WLAN_STA_BLOCK_BA);

  		}

  
  		mutex_unlock(&local->sta_mtx);

  	}

  	/* add back keys */
  	list_for_each_entry(sdata, &local->interfaces, list)

  		if (ieee80211_sdata_running(sdata))

  			ieee80211_enable_keys(sdata);

   wake_up:

  	ieee80211_wake_queues_by_reason(hw,
  			IEEE80211_QUEUE_STOP_REASON_SUSPEND);

  	/*
  	 * If this is for hw restart things are still running.
  	 * We may want to change that later, however.
  	 */

  	if (!local->suspended)

  		return 0;
  
  #ifdef CONFIG_PM

  	/* first set suspended false, then resuming */

  	local->suspended = false;

  	mb();
  	local->resuming = false;

  
  	list_for_each_entry(sdata, &local->interfaces, list) {
  		switch(sdata->vif.type) {
  		case NL80211_IFTYPE_STATION:
  			ieee80211_sta_restart(sdata);
  			break;
  		case NL80211_IFTYPE_ADHOC:
  			ieee80211_ibss_restart(sdata);
  			break;
  		case NL80211_IFTYPE_MESH_POINT:
  			ieee80211_mesh_restart(sdata);
  			break;
  		default:
  			break;
  		}
  	}

  	mod_timer(&local->sta_cleanup, jiffies + 1);

  	mutex_lock(&local->sta_mtx);

  	list_for_each_entry(sta, &local->sta_list, list)
  		mesh_plink_restart(sta);

  	mutex_unlock(&local->sta_mtx);

  #else
  	WARN_ON(1);
  #endif

  	return 0;
  }

  void ieee80211_resume_disconnect(struct ieee80211_vif *vif)
  {
  	struct ieee80211_sub_if_data *sdata;
  	struct ieee80211_local *local;
  	struct ieee80211_key *key;
  
  	if (WARN_ON(!vif))
  		return;
  
  	sdata = vif_to_sdata(vif);
  	local = sdata->local;
  
  	if (WARN_ON(!local->resuming))
  		return;
  
  	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
  		return;
  
  	sdata->flags |= IEEE80211_SDATA_DISCONNECT_RESUME;
  
  	mutex_lock(&local->key_mtx);
  	list_for_each_entry(key, &sdata->key_list, list)
  		key->flags |= KEY_FLAG_TAINTED;
  	mutex_unlock(&local->key_mtx);
  }
  EXPORT_SYMBOL_GPL(ieee80211_resume_disconnect);

  static int check_mgd_smps(struct ieee80211_if_managed *ifmgd,
  			  enum ieee80211_smps_mode *smps_mode)
  {
  	if (ifmgd->associated) {
  		*smps_mode = ifmgd->ap_smps;
  
  		if (*smps_mode == IEEE80211_SMPS_AUTOMATIC) {
  			if (ifmgd->powersave)
  				*smps_mode = IEEE80211_SMPS_DYNAMIC;
  			else
  				*smps_mode = IEEE80211_SMPS_OFF;
  		}
  
  		return 1;
  	}
  
  	return 0;
  }
  
  /* must hold iflist_mtx */

  void ieee80211_recalc_smps(struct ieee80211_local *local)

  {
  	struct ieee80211_sub_if_data *sdata;
  	enum ieee80211_smps_mode smps_mode = IEEE80211_SMPS_OFF;
  	int count = 0;

  	lockdep_assert_held(&local->iflist_mtx);

  
  	/*
  	 * This function could be improved to handle multiple
  	 * interfaces better, but right now it makes any
  	 * non-station interfaces force SM PS to be turned
  	 * off. If there are multiple station interfaces it
  	 * could also use the best possible mode, e.g. if
  	 * one is in static and the other in dynamic then
  	 * dynamic is ok.
  	 */
  
  	list_for_each_entry(sdata, &local->interfaces, list) {

  		if (!ieee80211_sdata_running(sdata))

  			continue;
  		if (sdata->vif.type != NL80211_IFTYPE_STATION)
  			goto set;

  
  		count += check_mgd_smps(&sdata->u.mgd, &smps_mode);

  
  		if (count > 1) {
  			smps_mode = IEEE80211_SMPS_OFF;
  			break;
  		}
  	}
  
  	if (smps_mode == local->smps_mode)
  		return;
  
   set:
  	local->smps_mode = smps_mode;
  	/* changed flag is auto-detected for this */
  	ieee80211_hw_config(local, 0);
  }

  
  static bool ieee80211_id_in_list(const u8 *ids, int n_ids, u8 id)
  {
  	int i;
  
  	for (i = 0; i < n_ids; i++)
  		if (ids[i] == id)
  			return true;
  	return false;
  }
  
  /**
   * ieee80211_ie_split - split an IE buffer according to ordering
   *
   * @ies: the IE buffer
   * @ielen: the length of the IE buffer
   * @ids: an array with element IDs that are allowed before
   *	the split
   * @n_ids: the size of the element ID array
   * @offset: offset where to start splitting in the buffer
   *
   * This function splits an IE buffer by updating the @offset
   * variable to point to the location where the buffer should be
   * split.
   *
   * It assumes that the given IE buffer is well-formed, this
   * has to be guaranteed by the caller!
   *
   * It also assumes that the IEs in the buffer are ordered
   * correctly, if not the result of using this function will not
   * be ordered correctly either, i.e. it does no reordering.
   *
   * The function returns the offset where the next part of the
   * buffer starts, which may be @ielen if the entire (remainder)
   * of the buffer should be used.
   */
  size_t ieee80211_ie_split(const u8 *ies, size_t ielen,
  			  const u8 *ids, int n_ids, size_t offset)
  {
  	size_t pos = offset;
  
  	while (pos < ielen && ieee80211_id_in_list(ids, n_ids, ies[pos]))
  		pos += 2 + ies[pos + 1];
  
  	return pos;
  }
  
  size_t ieee80211_ie_split_vendor(const u8 *ies, size_t ielen, size_t offset)
  {
  	size_t pos = offset;
  
  	while (pos < ielen && ies[pos] != WLAN_EID_VENDOR_SPECIFIC)
  		pos += 2 + ies[pos + 1];
  
  	return pos;
  }

  
  static void _ieee80211_enable_rssi_reports(struct ieee80211_sub_if_data *sdata,
  					    int rssi_min_thold,
  					    int rssi_max_thold)
  {
  	trace_api_enable_rssi_reports(sdata, rssi_min_thold, rssi_max_thold);
  
  	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_STATION))
  		return;
  
  	/*
  	 * Scale up threshold values before storing it, as the RSSI averaging
  	 * algorithm uses a scaled up value as well. Change this scaling
  	 * factor if the RSSI averaging algorithm changes.
  	 */
  	sdata->u.mgd.rssi_min_thold = rssi_min_thold*16;
  	sdata->u.mgd.rssi_max_thold = rssi_max_thold*16;
  }
  
  void ieee80211_enable_rssi_reports(struct ieee80211_vif *vif,
  				    int rssi_min_thold,
  				    int rssi_max_thold)
  {
  	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
  
  	WARN_ON(rssi_min_thold == rssi_max_thold ||
  		rssi_min_thold > rssi_max_thold);
  
  	_ieee80211_enable_rssi_reports(sdata, rssi_min_thold,
  				       rssi_max_thold);
  }
  EXPORT_SYMBOL(ieee80211_enable_rssi_reports);
  
  void ieee80211_disable_rssi_reports(struct ieee80211_vif *vif)
  {
  	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
  
  	_ieee80211_enable_rssi_reports(sdata, 0, 0);
  }
  EXPORT_SYMBOL(ieee80211_disable_rssi_reports);

  u8 *ieee80211_ie_build_ht_cap(u8 *pos, struct ieee80211_sta_ht_cap *ht_cap,

  			      u16 cap)
  {
  	__le16 tmp;
  
  	*pos++ = WLAN_EID_HT_CAPABILITY;
  	*pos++ = sizeof(struct ieee80211_ht_cap);
  	memset(pos, 0, sizeof(struct ieee80211_ht_cap));
  
  	/* capability flags */
  	tmp = cpu_to_le16(cap);
  	memcpy(pos, &tmp, sizeof(u16));
  	pos += sizeof(u16);
  
  	/* AMPDU parameters */

  	*pos++ = ht_cap->ampdu_factor |
  		 (ht_cap->ampdu_density <<

  			IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT);
  
  	/* MCS set */

  	memcpy(pos, &ht_cap->mcs, sizeof(ht_cap->mcs));
  	pos += sizeof(ht_cap->mcs);

  
  	/* extended capabilities */
  	pos += sizeof(__le16);
  
  	/* BF capabilities */
  	pos += sizeof(__le32);
  
  	/* antenna selection */
  	pos += sizeof(u8);
  
  	return pos;
  }
  
  u8 *ieee80211_ie_build_ht_info(u8 *pos,
  			       struct ieee80211_sta_ht_cap *ht_cap,
  			       struct ieee80211_channel *channel,
  			       enum nl80211_channel_type channel_type)
  {
  	struct ieee80211_ht_info *ht_info;
  	/* Build HT Information */
  	*pos++ = WLAN_EID_HT_INFORMATION;
  	*pos++ = sizeof(struct ieee80211_ht_info);
  	ht_info = (struct ieee80211_ht_info *)pos;
  	ht_info->control_chan =
  			ieee80211_frequency_to_channel(channel->center_freq);
  	switch (channel_type) {
  	case NL80211_CHAN_HT40MINUS:
  		ht_info->ht_param = IEEE80211_HT_PARAM_CHA_SEC_BELOW;
  		break;
  	case NL80211_CHAN_HT40PLUS:
  		ht_info->ht_param = IEEE80211_HT_PARAM_CHA_SEC_ABOVE;
  		break;
  	case NL80211_CHAN_HT20:
  	default:
  		ht_info->ht_param = IEEE80211_HT_PARAM_CHA_SEC_NONE;
  		break;
  	}
  	if (ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40)
  		ht_info->ht_param |= IEEE80211_HT_PARAM_CHAN_WIDTH_ANY;

  
  	/*
  	 * Note: According to 802.11n-2009 9.13.3.1, HT Protection field and
  	 * RIFS Mode are reserved in IBSS mode, therefore keep them at 0
  	 */

  	ht_info->operation_mode = 0x0000;
  	ht_info->stbc_param = 0x0000;
  
  	/* It seems that Basic MCS set and Supported MCS set
  	   are identical for the first 10 bytes */
  	memset(&ht_info->basic_set, 0, 16);
  	memcpy(&ht_info->basic_set, &ht_cap->mcs, 10);
  
  	return pos + sizeof(struct ieee80211_ht_info);
  }
  
  enum nl80211_channel_type
  ieee80211_ht_info_to_channel_type(struct ieee80211_ht_info *ht_info)
  {
  	enum nl80211_channel_type channel_type;
  
  	if (!ht_info)
  		return NL80211_CHAN_NO_HT;
  
  	switch (ht_info->ht_param & IEEE80211_HT_PARAM_CHA_SEC_OFFSET) {
  	case IEEE80211_HT_PARAM_CHA_SEC_NONE:
  		channel_type = NL80211_CHAN_HT20;
  		break;
  	case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
  		channel_type = NL80211_CHAN_HT40PLUS;
  		break;
  	case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
  		channel_type = NL80211_CHAN_HT40MINUS;
  		break;
  	default:
  		channel_type = NL80211_CHAN_NO_HT;
  	}
  
  	return channel_type;
  }

  int ieee80211_add_srates_ie(struct ieee80211_vif *vif, struct sk_buff *skb)
  {
  	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
  	struct ieee80211_local *local = sdata->local;
  	struct ieee80211_supported_band *sband;
  	int rate;
  	u8 i, rates, *pos;
  
  	sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
  	rates = sband->n_bitrates;
  	if (rates > 8)
  		rates = 8;
  
  	if (skb_tailroom(skb) < rates + 2)
  		return -ENOMEM;
  
  	pos = skb_put(skb, rates + 2);
  	*pos++ = WLAN_EID_SUPP_RATES;
  	*pos++ = rates;
  	for (i = 0; i < rates; i++) {
  		rate = sband->bitrates[i].bitrate;
  		*pos++ = (u8) (rate / 5);
  	}
  
  	return 0;
  }
  
  int ieee80211_add_ext_srates_ie(struct ieee80211_vif *vif, struct sk_buff *skb)
  {
  	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
  	struct ieee80211_local *local = sdata->local;
  	struct ieee80211_supported_band *sband;
  	int rate;
  	u8 i, exrates, *pos;
  
  	sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
  	exrates = sband->n_bitrates;
  	if (exrates > 8)
  		exrates -= 8;
  	else
  		exrates = 0;
  
  	if (skb_tailroom(skb) < exrates + 2)
  		return -ENOMEM;
  
  	if (exrates) {
  		pos = skb_put(skb, exrates + 2);
  		*pos++ = WLAN_EID_EXT_SUPP_RATES;
  		*pos++ = exrates;
  		for (i = 8; i < sband->n_bitrates; i++) {
  			rate = sband->bitrates[i].bitrate;
  			*pos++ = (u8) (rate / 5);
  		}
  	}
  	return 0;
  }