/*
   * mac80211 TDLS handling code
   *
   * Copyright 2006-2010	Johannes Berg <johannes@sipsolutions.net>
   * Copyright 2014, Intel Corporation

   * Copyright 2014  Intel Mobile Communications GmbH

   * Copyright 2015 - 2016 Intel Deutschland GmbH

   *
   * This file is GPLv2 as found in COPYING.
   */
  
  #include <linux/ieee80211.h>

  #include <linux/log2.h>

  #include <net/cfg80211.h>

  #include <linux/rtnetlink.h>

  #include "ieee80211_i.h"

  #include "driver-ops.h"

  #include "rate.h"

  #include "wme.h"

  /* give usermode some time for retries in setting up the TDLS session */
  #define TDLS_PEER_SETUP_TIMEOUT	(15 * HZ)
  
  void ieee80211_tdls_peer_del_work(struct work_struct *wk)
  {
  	struct ieee80211_sub_if_data *sdata;
  	struct ieee80211_local *local;
  
  	sdata = container_of(wk, struct ieee80211_sub_if_data,

  			     u.mgd.tdls_peer_del_work.work);

  	local = sdata->local;
  
  	mutex_lock(&local->mtx);

  	if (!is_zero_ether_addr(sdata->u.mgd.tdls_peer)) {
  		tdls_dbg(sdata, "TDLS del peer %pM
  ", sdata->u.mgd.tdls_peer);
  		sta_info_destroy_addr(sdata, sdata->u.mgd.tdls_peer);
  		eth_zero_addr(sdata->u.mgd.tdls_peer);

  	}
  	mutex_unlock(&local->mtx);
  }

  static void ieee80211_tdls_add_ext_capab(struct ieee80211_sub_if_data *sdata,

  					 struct sk_buff *skb)

  {

  	struct ieee80211_local *local = sdata->local;

  	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;

  	bool chan_switch = local->hw.wiphy->features &
  			   NL80211_FEATURE_TDLS_CHANNEL_SWITCH;

  	bool wider_band = ieee80211_hw_check(&local->hw, TDLS_WIDER_BW) &&
  			  !ifmgd->tdls_wider_bw_prohibited;

  	struct ieee80211_supported_band *sband = ieee80211_get_sband(sdata);

  	bool vht = sband && sband->vht_cap.vht_supported;

  	u8 *pos = skb_put(skb, 10);

  
  	*pos++ = WLAN_EID_EXT_CAPABILITY;

  	*pos++ = 8; /* len */

  	*pos++ = 0x0;
  	*pos++ = 0x0;
  	*pos++ = 0x0;

  	*pos++ = chan_switch ? WLAN_EXT_CAPA4_TDLS_CHAN_SWITCH : 0;

  	*pos++ = WLAN_EXT_CAPA5_TDLS_ENABLED;

  	*pos++ = 0;
  	*pos++ = 0;
  	*pos++ = (vht && wider_band) ? WLAN_EXT_CAPA8_TDLS_WIDE_BW_ENABLED : 0;

  }

  static u8
  ieee80211_tdls_add_subband(struct ieee80211_sub_if_data *sdata,
  			   struct sk_buff *skb, u16 start, u16 end,
  			   u16 spacing)
  {
  	u8 subband_cnt = 0, ch_cnt = 0;
  	struct ieee80211_channel *ch;
  	struct cfg80211_chan_def chandef;
  	int i, subband_start;

  	struct wiphy *wiphy = sdata->local->hw.wiphy;

  
  	for (i = start; i <= end; i += spacing) {
  		if (!ch_cnt)
  			subband_start = i;
  
  		ch = ieee80211_get_channel(sdata->local->hw.wiphy, i);
  		if (ch) {
  			/* we will be active on the channel */

  			cfg80211_chandef_create(&chandef, ch,

  						NL80211_CHAN_NO_HT);

  			if (cfg80211_reg_can_beacon_relax(wiphy, &chandef,
  							  sdata->wdev.iftype)) {

  				ch_cnt++;

  				/*
  				 * check if the next channel is also part of
  				 * this allowed range
  				 */

  				continue;
  			}
  		}

  		/*
  		 * we've reached the end of a range, with allowed channels
  		 * found
  		 */

  		if (ch_cnt) {
  			u8 *pos = skb_put(skb, 2);
  			*pos++ = ieee80211_frequency_to_channel(subband_start);
  			*pos++ = ch_cnt;
  
  			subband_cnt++;
  			ch_cnt = 0;
  		}
  	}

  	/* all channels in the requested range are allowed - add them here */
  	if (ch_cnt) {
  		u8 *pos = skb_put(skb, 2);
  		*pos++ = ieee80211_frequency_to_channel(subband_start);
  		*pos++ = ch_cnt;
  
  		subband_cnt++;
  	}

  	return subband_cnt;
  }
  
  static void
  ieee80211_tdls_add_supp_channels(struct ieee80211_sub_if_data *sdata,
  				 struct sk_buff *skb)
  {
  	/*
  	 * Add possible channels for TDLS. These are channels that are allowed
  	 * to be active.
  	 */
  	u8 subband_cnt;
  	u8 *pos = skb_put(skb, 2);
  
  	*pos++ = WLAN_EID_SUPPORTED_CHANNELS;
  
  	/*
  	 * 5GHz and 2GHz channels numbers can overlap. Ignore this for now, as
  	 * this doesn't happen in real world scenarios.
  	 */
  
  	/* 2GHz, with 5MHz spacing */
  	subband_cnt = ieee80211_tdls_add_subband(sdata, skb, 2412, 2472, 5);
  
  	/* 5GHz, with 20MHz spacing */
  	subband_cnt += ieee80211_tdls_add_subband(sdata, skb, 5000, 5825, 20);
  
  	/* length */
  	*pos = 2 * subband_cnt;
  }

  static void ieee80211_tdls_add_oper_classes(struct ieee80211_sub_if_data *sdata,
  					    struct sk_buff *skb)
  {
  	u8 *pos;
  	u8 op_class;
  
  	if (!ieee80211_chandef_to_operating_class(&sdata->vif.bss_conf.chandef,
  						  &op_class))
  		return;
  
  	pos = skb_put(skb, 4);
  	*pos++ = WLAN_EID_SUPPORTED_REGULATORY_CLASSES;
  	*pos++ = 2; /* len */
  
  	*pos++ = op_class;
  	*pos++ = op_class; /* give current operating class as alternate too */
  }

  static void ieee80211_tdls_add_bss_coex_ie(struct sk_buff *skb)
  {

  	u8 *pos = skb_put(skb, 3);

  
  	*pos++ = WLAN_EID_BSS_COEX_2040;
  	*pos++ = 1; /* len */
  
  	*pos++ = WLAN_BSS_COEX_INFORMATION_REQUEST;
  }

  static u16 ieee80211_get_tdls_sta_capab(struct ieee80211_sub_if_data *sdata,
  					u16 status_code)

  {

  	struct ieee80211_supported_band *sband;

  	/* The capability will be 0 when sending a failure code */
  	if (status_code != 0)
  		return 0;

  	sband = ieee80211_get_sband(sdata);
  	if (sband && sband->band == NL80211_BAND_2GHZ) {

  		return WLAN_CAPABILITY_SHORT_SLOT_TIME |
  		       WLAN_CAPABILITY_SHORT_PREAMBLE;
  	}

  	return 0;

  }

  static void ieee80211_tdls_add_link_ie(struct ieee80211_sub_if_data *sdata,
  				       struct sk_buff *skb, const u8 *peer,
  				       bool initiator)

  {
  	struct ieee80211_tdls_lnkie *lnkid;

  	const u8 *init_addr, *rsp_addr;
  
  	if (initiator) {
  		init_addr = sdata->vif.addr;
  		rsp_addr = peer;
  	} else {
  		init_addr = peer;
  		rsp_addr = sdata->vif.addr;
  	}

  	lnkid = skb_put(skb, sizeof(struct ieee80211_tdls_lnkie));

  
  	lnkid->ie_type = WLAN_EID_LINK_ID;
  	lnkid->ie_len = sizeof(struct ieee80211_tdls_lnkie) - 2;

  	memcpy(lnkid->bssid, sdata->u.mgd.bssid, ETH_ALEN);
  	memcpy(lnkid->init_sta, init_addr, ETH_ALEN);
  	memcpy(lnkid->resp_sta, rsp_addr, ETH_ALEN);

  }

  static void
  ieee80211_tdls_add_aid(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
  {
  	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;

  	u8 *pos = skb_put(skb, 4);

  
  	*pos++ = WLAN_EID_AID;
  	*pos++ = 2; /* len */
  	put_unaligned_le16(ifmgd->aid, pos);
  }

  /* translate numbering in the WMM parameter IE to the mac80211 notation */
  static enum ieee80211_ac_numbers ieee80211_ac_from_wmm(int ac)
  {
  	switch (ac) {
  	default:
  		WARN_ON_ONCE(1);
  	case 0:
  		return IEEE80211_AC_BE;
  	case 1:
  		return IEEE80211_AC_BK;
  	case 2:
  		return IEEE80211_AC_VI;
  	case 3:
  		return IEEE80211_AC_VO;
  	}
  }
  
  static u8 ieee80211_wmm_aci_aifsn(int aifsn, bool acm, int aci)
  {
  	u8 ret;
  
  	ret = aifsn & 0x0f;
  	if (acm)
  		ret |= 0x10;
  	ret |= (aci << 5) & 0x60;
  	return ret;
  }
  
  static u8 ieee80211_wmm_ecw(u16 cw_min, u16 cw_max)
  {
  	return ((ilog2(cw_min + 1) << 0x0) & 0x0f) |
  	       ((ilog2(cw_max + 1) << 0x4) & 0xf0);
  }
  
  static void ieee80211_tdls_add_wmm_param_ie(struct ieee80211_sub_if_data *sdata,
  					    struct sk_buff *skb)
  {
  	struct ieee80211_wmm_param_ie *wmm;
  	struct ieee80211_tx_queue_params *txq;
  	int i;

  	wmm = skb_put_zero(skb, sizeof(*wmm));

  
  	wmm->element_id = WLAN_EID_VENDOR_SPECIFIC;
  	wmm->len = sizeof(*wmm) - 2;
  
  	wmm->oui[0] = 0x00; /* Microsoft OUI 00:50:F2 */
  	wmm->oui[1] = 0x50;
  	wmm->oui[2] = 0xf2;
  	wmm->oui_type = 2; /* WME */
  	wmm->oui_subtype = 1; /* WME param */
  	wmm->version = 1; /* WME ver */
  	wmm->qos_info = 0; /* U-APSD not in use */
  
  	/*
  	 * Use the EDCA parameters defined for the BSS, or default if the AP
  	 * doesn't support it, as mandated by 802.11-2012 section 10.22.4
  	 */
  	for (i = 0; i < IEEE80211_NUM_ACS; i++) {
  		txq = &sdata->tx_conf[ieee80211_ac_from_wmm(i)];
  		wmm->ac[i].aci_aifsn = ieee80211_wmm_aci_aifsn(txq->aifs,
  							       txq->acm, i);
  		wmm->ac[i].cw = ieee80211_wmm_ecw(txq->cw_min, txq->cw_max);
  		wmm->ac[i].txop_limit = cpu_to_le16(txq->txop);
  	}
  }

  static void

  ieee80211_tdls_chandef_vht_upgrade(struct ieee80211_sub_if_data *sdata,
  				   struct sta_info *sta)
  {
  	/* IEEE802.11ac-2013 Table E-4 */
  	u16 centers_80mhz[] = { 5210, 5290, 5530, 5610, 5690, 5775 };
  	struct cfg80211_chan_def uc = sta->tdls_chandef;

  	enum nl80211_chan_width max_width = ieee80211_sta_cap_chan_bw(sta);

  	int i;
  
  	/* only support upgrading non-narrow channels up to 80Mhz */
  	if (max_width == NL80211_CHAN_WIDTH_5 ||
  	    max_width == NL80211_CHAN_WIDTH_10)
  		return;
  
  	if (max_width > NL80211_CHAN_WIDTH_80)
  		max_width = NL80211_CHAN_WIDTH_80;

  	if (uc.width >= max_width)

  		return;
  	/*
  	 * Channel usage constrains in the IEEE802.11ac-2013 specification only
  	 * allow expanding a 20MHz channel to 80MHz in a single way. In
  	 * addition, there are no 40MHz allowed channels that are not part of
  	 * the allowed 80MHz range in the 5GHz spectrum (the relevant one here).
  	 */
  	for (i = 0; i < ARRAY_SIZE(centers_80mhz); i++)
  		if (abs(uc.chan->center_freq - centers_80mhz[i]) <= 30) {
  			uc.center_freq1 = centers_80mhz[i];

  			uc.center_freq2 = 0;

  			uc.width = NL80211_CHAN_WIDTH_80;
  			break;
  		}
  
  	if (!uc.center_freq1)
  		return;

  	/* proceed to downgrade the chandef until usable or the same as AP BW */

  	while (uc.width > max_width ||

  	       (uc.width > sta->tdls_chandef.width &&
  		!cfg80211_reg_can_beacon_relax(sdata->local->hw.wiphy, &uc,
  					       sdata->wdev.iftype)))

  		ieee80211_chandef_downgrade(&uc);
  
  	if (!cfg80211_chandef_identical(&uc, &sta->tdls_chandef)) {
  		tdls_dbg(sdata, "TDLS ch width upgraded %d -> %d
  ",
  			 sta->tdls_chandef.width, uc.width);
  
  		/*
  		 * the station is not yet authorized when BW upgrade is done,
  		 * locking is not required
  		 */
  		sta->tdls_chandef = uc;
  	}
  }
  
  static void

  ieee80211_tdls_add_setup_start_ies(struct ieee80211_sub_if_data *sdata,
  				   struct sk_buff *skb, const u8 *peer,

  				   u8 action_code, bool initiator,
  				   const u8 *extra_ies, size_t extra_ies_len)

  {

  	struct ieee80211_supported_band *sband;

  	struct ieee80211_local *local = sdata->local;

  	struct ieee80211_sta_ht_cap ht_cap;

  	struct ieee80211_sta_vht_cap vht_cap;

  	struct sta_info *sta = NULL;

  	size_t offset = 0, noffset;
  	u8 *pos;

  	sband = ieee80211_get_sband(sdata);
  	if (!sband)
  		return;
  
  	ieee80211_add_srates_ie(sdata, skb, false, sband->band);
  	ieee80211_add_ext_srates_ie(sdata, skb, false, sband->band);

  	ieee80211_tdls_add_supp_channels(sdata, skb);

  
  	/* add any custom IEs that go before Extended Capabilities */
  	if (extra_ies_len) {
  		static const u8 before_ext_cap[] = {
  			WLAN_EID_SUPP_RATES,
  			WLAN_EID_COUNTRY,
  			WLAN_EID_EXT_SUPP_RATES,
  			WLAN_EID_SUPPORTED_CHANNELS,
  			WLAN_EID_RSN,
  		};
  		noffset = ieee80211_ie_split(extra_ies, extra_ies_len,
  					     before_ext_cap,
  					     ARRAY_SIZE(before_ext_cap),
  					     offset);

  		skb_put_data(skb, extra_ies + offset, noffset - offset);

  		offset = noffset;
  	}

  	ieee80211_tdls_add_ext_capab(sdata, skb);

  	/* add the QoS element if we support it */
  	if (local->hw.queues >= IEEE80211_NUM_ACS &&
  	    action_code != WLAN_PUB_ACTION_TDLS_DISCOVER_RES)
  		ieee80211_add_wmm_info_ie(skb_put(skb, 9), 0); /* no U-APSD */

  	/* add any custom IEs that go before HT capabilities */
  	if (extra_ies_len) {
  		static const u8 before_ht_cap[] = {
  			WLAN_EID_SUPP_RATES,
  			WLAN_EID_COUNTRY,
  			WLAN_EID_EXT_SUPP_RATES,
  			WLAN_EID_SUPPORTED_CHANNELS,
  			WLAN_EID_RSN,
  			WLAN_EID_EXT_CAPABILITY,
  			WLAN_EID_QOS_CAPA,
  			WLAN_EID_FAST_BSS_TRANSITION,
  			WLAN_EID_TIMEOUT_INTERVAL,
  			WLAN_EID_SUPPORTED_REGULATORY_CLASSES,
  		};
  		noffset = ieee80211_ie_split(extra_ies, extra_ies_len,
  					     before_ht_cap,
  					     ARRAY_SIZE(before_ht_cap),
  					     offset);

  		skb_put_data(skb, extra_ies + offset, noffset - offset);

  		offset = noffset;
  	}

  	mutex_lock(&local->sta_mtx);

  
  	/* we should have the peer STA if we're already responding */
  	if (action_code == WLAN_TDLS_SETUP_RESPONSE) {
  		sta = sta_info_get(sdata, peer);
  		if (WARN_ON_ONCE(!sta)) {

  			mutex_unlock(&local->sta_mtx);

  			return;
  		}

  
  		sta->tdls_chandef = sdata->vif.bss_conf.chandef;

  	}

  	ieee80211_tdls_add_oper_classes(sdata, skb);

  	/*
  	 * with TDLS we can switch channels, and HT-caps are not necessarily
  	 * the same on all bands. The specification limits the setup to a
  	 * single HT-cap, so use the current band for now.
  	 */

  	memcpy(&ht_cap, &sband->ht_cap, sizeof(ht_cap));

  	if ((action_code == WLAN_TDLS_SETUP_REQUEST ||
  	     action_code == WLAN_PUB_ACTION_TDLS_DISCOVER_RES) &&
  	    ht_cap.ht_supported) {

  		ieee80211_apply_htcap_overrides(sdata, &ht_cap);
  
  		/* disable SMPS in TDLS initiator */
  		ht_cap.cap |= WLAN_HT_CAP_SM_PS_DISABLED
  				<< IEEE80211_HT_CAP_SM_PS_SHIFT;
  
  		pos = skb_put(skb, sizeof(struct ieee80211_ht_cap) + 2);
  		ieee80211_ie_build_ht_cap(pos, &ht_cap, ht_cap.cap);
  	} else if (action_code == WLAN_TDLS_SETUP_RESPONSE &&
  		   ht_cap.ht_supported && sta->sta.ht_cap.ht_supported) {

  		/* the peer caps are already intersected with our own */
  		memcpy(&ht_cap, &sta->sta.ht_cap, sizeof(ht_cap));

  
  		pos = skb_put(skb, sizeof(struct ieee80211_ht_cap) + 2);
  		ieee80211_ie_build_ht_cap(pos, &ht_cap, ht_cap.cap);
  	}

  	if (ht_cap.ht_supported &&
  	    (ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40))
  		ieee80211_tdls_add_bss_coex_ie(skb);

  	ieee80211_tdls_add_link_ie(sdata, skb, peer, initiator);
  
  	/* add any custom IEs that go before VHT capabilities */
  	if (extra_ies_len) {
  		static const u8 before_vht_cap[] = {
  			WLAN_EID_SUPP_RATES,
  			WLAN_EID_COUNTRY,
  			WLAN_EID_EXT_SUPP_RATES,
  			WLAN_EID_SUPPORTED_CHANNELS,
  			WLAN_EID_RSN,
  			WLAN_EID_EXT_CAPABILITY,
  			WLAN_EID_QOS_CAPA,
  			WLAN_EID_FAST_BSS_TRANSITION,
  			WLAN_EID_TIMEOUT_INTERVAL,
  			WLAN_EID_SUPPORTED_REGULATORY_CLASSES,
  			WLAN_EID_MULTI_BAND,
  		};
  		noffset = ieee80211_ie_split(extra_ies, extra_ies_len,
  					     before_vht_cap,
  					     ARRAY_SIZE(before_vht_cap),
  					     offset);

  		skb_put_data(skb, extra_ies + offset, noffset - offset);

  		offset = noffset;
  	}
  
  	/* build the VHT-cap similarly to the HT-cap */
  	memcpy(&vht_cap, &sband->vht_cap, sizeof(vht_cap));

  	if ((action_code == WLAN_TDLS_SETUP_REQUEST ||
  	     action_code == WLAN_PUB_ACTION_TDLS_DISCOVER_RES) &&
  	    vht_cap.vht_supported) {

  		ieee80211_apply_vhtcap_overrides(sdata, &vht_cap);
  
  		/* the AID is present only when VHT is implemented */

  		if (action_code == WLAN_TDLS_SETUP_REQUEST)
  			ieee80211_tdls_add_aid(sdata, skb);

  
  		pos = skb_put(skb, sizeof(struct ieee80211_vht_cap) + 2);
  		ieee80211_ie_build_vht_cap(pos, &vht_cap, vht_cap.cap);
  	} else if (action_code == WLAN_TDLS_SETUP_RESPONSE &&
  		   vht_cap.vht_supported && sta->sta.vht_cap.vht_supported) {
  		/* the peer caps are already intersected with our own */
  		memcpy(&vht_cap, &sta->sta.vht_cap, sizeof(vht_cap));
  
  		/* the AID is present only when VHT is implemented */
  		ieee80211_tdls_add_aid(sdata, skb);
  
  		pos = skb_put(skb, sizeof(struct ieee80211_vht_cap) + 2);
  		ieee80211_ie_build_vht_cap(pos, &vht_cap, vht_cap.cap);

  
  		/*
  		 * if both peers support WIDER_BW, we can expand the chandef to
  		 * a wider compatible one, up to 80MHz
  		 */
  		if (test_sta_flag(sta, WLAN_STA_TDLS_WIDER_BW))
  			ieee80211_tdls_chandef_vht_upgrade(sdata, sta);

  	}

  	mutex_unlock(&local->sta_mtx);

  	/* add any remaining IEs */
  	if (extra_ies_len) {
  		noffset = extra_ies_len;

  		skb_put_data(skb, extra_ies + offset, noffset - offset);

  	}

  }

  static void
  ieee80211_tdls_add_setup_cfm_ies(struct ieee80211_sub_if_data *sdata,
  				 struct sk_buff *skb, const u8 *peer,
  				 bool initiator, const u8 *extra_ies,
  				 size_t extra_ies_len)
  {
  	struct ieee80211_local *local = sdata->local;

  	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;

  	size_t offset = 0, noffset;

  	struct sta_info *sta, *ap_sta;

  	struct ieee80211_supported_band *sband;

  	u8 *pos;

  	sband = ieee80211_get_sband(sdata);
  	if (!sband)
  		return;

  	mutex_lock(&local->sta_mtx);

  
  	sta = sta_info_get(sdata, peer);

  	ap_sta = sta_info_get(sdata, ifmgd->bssid);
  	if (WARN_ON_ONCE(!sta || !ap_sta)) {

  		mutex_unlock(&local->sta_mtx);

  		return;
  	}

  	sta->tdls_chandef = sdata->vif.bss_conf.chandef;

  	/* add any custom IEs that go before the QoS IE */
  	if (extra_ies_len) {
  		static const u8 before_qos[] = {
  			WLAN_EID_RSN,
  		};
  		noffset = ieee80211_ie_split(extra_ies, extra_ies_len,
  					     before_qos,
  					     ARRAY_SIZE(before_qos),
  					     offset);

  		skb_put_data(skb, extra_ies + offset, noffset - offset);

  		offset = noffset;
  	}
  
  	/* add the QoS param IE if both the peer and we support it */

  	if (local->hw.queues >= IEEE80211_NUM_ACS && sta->sta.wme)

  		ieee80211_tdls_add_wmm_param_ie(sdata, skb);

  	/* add any custom IEs that go before HT operation */
  	if (extra_ies_len) {
  		static const u8 before_ht_op[] = {
  			WLAN_EID_RSN,
  			WLAN_EID_QOS_CAPA,
  			WLAN_EID_FAST_BSS_TRANSITION,
  			WLAN_EID_TIMEOUT_INTERVAL,
  		};
  		noffset = ieee80211_ie_split(extra_ies, extra_ies_len,
  					     before_ht_op,
  					     ARRAY_SIZE(before_ht_op),
  					     offset);

  		skb_put_data(skb, extra_ies + offset, noffset - offset);

  		offset = noffset;
  	}

  	/*
  	 * if HT support is only added in TDLS, we need an HT-operation IE.
  	 * add the IE as required by IEEE802.11-2012 9.23.3.2.
  	 */

  	if (!ap_sta->sta.ht_cap.ht_supported && sta->sta.ht_cap.ht_supported) {

  		u16 prot = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED |
  			   IEEE80211_HT_OP_MODE_NON_GF_STA_PRSNT |
  			   IEEE80211_HT_OP_MODE_NON_HT_STA_PRSNT;

  		pos = skb_put(skb, 2 + sizeof(struct ieee80211_ht_operation));

  		ieee80211_ie_build_ht_oper(pos, &sta->sta.ht_cap,

  					   &sdata->vif.bss_conf.chandef, prot,
  					   true);

  	}

  	ieee80211_tdls_add_link_ie(sdata, skb, peer, initiator);
  
  	/* only include VHT-operation if not on the 2.4GHz band */

  	if (sband->band != NL80211_BAND_2GHZ &&
  	    sta->sta.vht_cap.vht_supported) {

  		/*
  		 * if both peers support WIDER_BW, we can expand the chandef to
  		 * a wider compatible one, up to 80MHz
  		 */
  		if (test_sta_flag(sta, WLAN_STA_TDLS_WIDER_BW))
  			ieee80211_tdls_chandef_vht_upgrade(sdata, sta);

  		pos = skb_put(skb, 2 + sizeof(struct ieee80211_vht_operation));
  		ieee80211_ie_build_vht_oper(pos, &sta->sta.vht_cap,

  					    &sta->tdls_chandef);

  	}

  	mutex_unlock(&local->sta_mtx);

  	/* add any remaining IEs */
  	if (extra_ies_len) {
  		noffset = extra_ies_len;

  		skb_put_data(skb, extra_ies + offset, noffset - offset);

  	}

  }

  static void
  ieee80211_tdls_add_chan_switch_req_ies(struct ieee80211_sub_if_data *sdata,
  				       struct sk_buff *skb, const u8 *peer,
  				       bool initiator, const u8 *extra_ies,
  				       size_t extra_ies_len, u8 oper_class,
  				       struct cfg80211_chan_def *chandef)
  {
  	struct ieee80211_tdls_data *tf;
  	size_t offset = 0, noffset;

  
  	if (WARN_ON_ONCE(!chandef))
  		return;
  
  	tf = (void *)skb->data;
  	tf->u.chan_switch_req.target_channel =
  		ieee80211_frequency_to_channel(chandef->chan->center_freq);
  	tf->u.chan_switch_req.oper_class = oper_class;
  
  	if (extra_ies_len) {
  		static const u8 before_lnkie[] = {
  			WLAN_EID_SECONDARY_CHANNEL_OFFSET,
  		};
  		noffset = ieee80211_ie_split(extra_ies, extra_ies_len,
  					     before_lnkie,
  					     ARRAY_SIZE(before_lnkie),
  					     offset);

  		skb_put_data(skb, extra_ies + offset, noffset - offset);

  		offset = noffset;
  	}
  
  	ieee80211_tdls_add_link_ie(sdata, skb, peer, initiator);
  
  	/* add any remaining IEs */
  	if (extra_ies_len) {
  		noffset = extra_ies_len;

  		skb_put_data(skb, extra_ies + offset, noffset - offset);

  	}
  }

  static void
  ieee80211_tdls_add_chan_switch_resp_ies(struct ieee80211_sub_if_data *sdata,
  					struct sk_buff *skb, const u8 *peer,
  					u16 status_code, bool initiator,
  					const u8 *extra_ies,
  					size_t extra_ies_len)
  {
  	if (status_code == 0)
  		ieee80211_tdls_add_link_ie(sdata, skb, peer, initiator);
  
  	if (extra_ies_len)

  		skb_put_data(skb, extra_ies, extra_ies_len);

  }

  static void ieee80211_tdls_add_ies(struct ieee80211_sub_if_data *sdata,
  				   struct sk_buff *skb, const u8 *peer,

  				   u8 action_code, u16 status_code,
  				   bool initiator, const u8 *extra_ies,

  				   size_t extra_ies_len, u8 oper_class,
  				   struct cfg80211_chan_def *chandef)

  {

  	switch (action_code) {
  	case WLAN_TDLS_SETUP_REQUEST:
  	case WLAN_TDLS_SETUP_RESPONSE:
  	case WLAN_PUB_ACTION_TDLS_DISCOVER_RES:

  		if (status_code == 0)
  			ieee80211_tdls_add_setup_start_ies(sdata, skb, peer,
  							   action_code,
  							   initiator,
  							   extra_ies,
  							   extra_ies_len);

  		break;
  	case WLAN_TDLS_SETUP_CONFIRM:

  		if (status_code == 0)
  			ieee80211_tdls_add_setup_cfm_ies(sdata, skb, peer,
  							 initiator, extra_ies,
  							 extra_ies_len);
  		break;

  	case WLAN_TDLS_TEARDOWN:
  	case WLAN_TDLS_DISCOVERY_REQUEST:

  		if (extra_ies_len)

  			skb_put_data(skb, extra_ies, extra_ies_len);

  		if (status_code == 0 || action_code == WLAN_TDLS_TEARDOWN)
  			ieee80211_tdls_add_link_ie(sdata, skb, peer, initiator);

  		break;

  	case WLAN_TDLS_CHANNEL_SWITCH_REQUEST:
  		ieee80211_tdls_add_chan_switch_req_ies(sdata, skb, peer,
  						       initiator, extra_ies,
  						       extra_ies_len,
  						       oper_class, chandef);
  		break;

  	case WLAN_TDLS_CHANNEL_SWITCH_RESPONSE:
  		ieee80211_tdls_add_chan_switch_resp_ies(sdata, skb, peer,
  							status_code,
  							initiator, extra_ies,
  							extra_ies_len);
  		break;

  	}

  }

  static int
  ieee80211_prep_tdls_encap_data(struct wiphy *wiphy, struct net_device *dev,

  			       const u8 *peer, u8 action_code, u8 dialog_token,

  			       u16 status_code, struct sk_buff *skb)
  {
  	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);

  	struct ieee80211_tdls_data *tf;

  	tf = skb_put(skb, offsetof(struct ieee80211_tdls_data, u));

  
  	memcpy(tf->da, peer, ETH_ALEN);
  	memcpy(tf->sa, sdata->vif.addr, ETH_ALEN);
  	tf->ether_type = cpu_to_be16(ETH_P_TDLS);
  	tf->payload_type = WLAN_TDLS_SNAP_RFTYPE;

  	/* network header is after the ethernet header */
  	skb_set_network_header(skb, ETH_HLEN);

  	switch (action_code) {
  	case WLAN_TDLS_SETUP_REQUEST:
  		tf->category = WLAN_CATEGORY_TDLS;
  		tf->action_code = WLAN_TDLS_SETUP_REQUEST;
  
  		skb_put(skb, sizeof(tf->u.setup_req));
  		tf->u.setup_req.dialog_token = dialog_token;
  		tf->u.setup_req.capability =

  			cpu_to_le16(ieee80211_get_tdls_sta_capab(sdata,
  								 status_code));

  		break;
  	case WLAN_TDLS_SETUP_RESPONSE:
  		tf->category = WLAN_CATEGORY_TDLS;
  		tf->action_code = WLAN_TDLS_SETUP_RESPONSE;
  
  		skb_put(skb, sizeof(tf->u.setup_resp));
  		tf->u.setup_resp.status_code = cpu_to_le16(status_code);
  		tf->u.setup_resp.dialog_token = dialog_token;
  		tf->u.setup_resp.capability =

  			cpu_to_le16(ieee80211_get_tdls_sta_capab(sdata,
  								 status_code));

  		break;
  	case WLAN_TDLS_SETUP_CONFIRM:
  		tf->category = WLAN_CATEGORY_TDLS;
  		tf->action_code = WLAN_TDLS_SETUP_CONFIRM;
  
  		skb_put(skb, sizeof(tf->u.setup_cfm));
  		tf->u.setup_cfm.status_code = cpu_to_le16(status_code);
  		tf->u.setup_cfm.dialog_token = dialog_token;
  		break;
  	case WLAN_TDLS_TEARDOWN:
  		tf->category = WLAN_CATEGORY_TDLS;
  		tf->action_code = WLAN_TDLS_TEARDOWN;
  
  		skb_put(skb, sizeof(tf->u.teardown));
  		tf->u.teardown.reason_code = cpu_to_le16(status_code);
  		break;
  	case WLAN_TDLS_DISCOVERY_REQUEST:
  		tf->category = WLAN_CATEGORY_TDLS;
  		tf->action_code = WLAN_TDLS_DISCOVERY_REQUEST;
  
  		skb_put(skb, sizeof(tf->u.discover_req));
  		tf->u.discover_req.dialog_token = dialog_token;
  		break;

  	case WLAN_TDLS_CHANNEL_SWITCH_REQUEST:
  		tf->category = WLAN_CATEGORY_TDLS;
  		tf->action_code = WLAN_TDLS_CHANNEL_SWITCH_REQUEST;
  
  		skb_put(skb, sizeof(tf->u.chan_switch_req));
  		break;

  	case WLAN_TDLS_CHANNEL_SWITCH_RESPONSE:
  		tf->category = WLAN_CATEGORY_TDLS;
  		tf->action_code = WLAN_TDLS_CHANNEL_SWITCH_RESPONSE;
  
  		skb_put(skb, sizeof(tf->u.chan_switch_resp));
  		tf->u.chan_switch_resp.status_code = cpu_to_le16(status_code);
  		break;

  	default:
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  static int
  ieee80211_prep_tdls_direct(struct wiphy *wiphy, struct net_device *dev,

  			   const u8 *peer, u8 action_code, u8 dialog_token,

  			   u16 status_code, struct sk_buff *skb)
  {
  	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);

  	struct ieee80211_mgmt *mgmt;

  	mgmt = skb_put_zero(skb, 24);

  	memcpy(mgmt->da, peer, ETH_ALEN);
  	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
  	memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
  
  	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
  					  IEEE80211_STYPE_ACTION);
  
  	switch (action_code) {
  	case WLAN_PUB_ACTION_TDLS_DISCOVER_RES:
  		skb_put(skb, 1 + sizeof(mgmt->u.action.u.tdls_discover_resp));
  		mgmt->u.action.category = WLAN_CATEGORY_PUBLIC;
  		mgmt->u.action.u.tdls_discover_resp.action_code =
  			WLAN_PUB_ACTION_TDLS_DISCOVER_RES;
  		mgmt->u.action.u.tdls_discover_resp.dialog_token =
  			dialog_token;
  		mgmt->u.action.u.tdls_discover_resp.capability =

  			cpu_to_le16(ieee80211_get_tdls_sta_capab(sdata,
  								 status_code));

  		break;
  	default:
  		return -EINVAL;
  	}
  
  	return 0;
  }

  static struct sk_buff *
  ieee80211_tdls_build_mgmt_packet_data(struct ieee80211_sub_if_data *sdata,
  				      const u8 *peer, u8 action_code,
  				      u8 dialog_token, u16 status_code,
  				      bool initiator, const u8 *extra_ies,
  				      size_t extra_ies_len, u8 oper_class,
  				      struct cfg80211_chan_def *chandef)

  {

  	struct ieee80211_local *local = sdata->local;

  	struct sk_buff *skb;

  	int ret;

  	skb = netdev_alloc_skb(sdata->dev,

  			       local->hw.extra_tx_headroom +
  			       max(sizeof(struct ieee80211_mgmt),
  				   sizeof(struct ieee80211_tdls_data)) +
  			       50 + /* supported rates */

  			       10 + /* ext capab */

  			       26 + /* max(WMM-info, WMM-param) */
  			       2 + max(sizeof(struct ieee80211_ht_cap),
  				       sizeof(struct ieee80211_ht_operation)) +

  			       2 + max(sizeof(struct ieee80211_vht_cap),
  				       sizeof(struct ieee80211_vht_operation)) +

  			       50 + /* supported channels */

  			       3 + /* 40/20 BSS coex */

  			       4 + /* AID */

  			       4 + /* oper classes */

  			       extra_ies_len +
  			       sizeof(struct ieee80211_tdls_lnkie));

  	if (!skb)

  		return NULL;

  
  	skb_reserve(skb, local->hw.extra_tx_headroom);
  
  	switch (action_code) {
  	case WLAN_TDLS_SETUP_REQUEST:
  	case WLAN_TDLS_SETUP_RESPONSE:
  	case WLAN_TDLS_SETUP_CONFIRM:
  	case WLAN_TDLS_TEARDOWN:
  	case WLAN_TDLS_DISCOVERY_REQUEST:

  	case WLAN_TDLS_CHANNEL_SWITCH_REQUEST:

  	case WLAN_TDLS_CHANNEL_SWITCH_RESPONSE:

  		ret = ieee80211_prep_tdls_encap_data(local->hw.wiphy,
  						     sdata->dev, peer,

  						     action_code, dialog_token,
  						     status_code, skb);

  		break;
  	case WLAN_PUB_ACTION_TDLS_DISCOVER_RES:

  		ret = ieee80211_prep_tdls_direct(local->hw.wiphy, sdata->dev,
  						 peer, action_code,

  						 dialog_token, status_code,
  						 skb);

  		break;
  	default:
  		ret = -ENOTSUPP;
  		break;
  	}
  
  	if (ret < 0)
  		goto fail;

  	ieee80211_tdls_add_ies(sdata, skb, peer, action_code, status_code,
  			       initiator, extra_ies, extra_ies_len, oper_class,
  			       chandef);
  	return skb;
  
  fail:
  	dev_kfree_skb(skb);
  	return NULL;
  }
  
  static int
  ieee80211_tdls_prep_mgmt_packet(struct wiphy *wiphy, struct net_device *dev,
  				const u8 *peer, u8 action_code, u8 dialog_token,
  				u16 status_code, u32 peer_capability,
  				bool initiator, const u8 *extra_ies,
  				size_t extra_ies_len, u8 oper_class,
  				struct cfg80211_chan_def *chandef)
  {
  	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
  	struct sk_buff *skb = NULL;
  	struct sta_info *sta;
  	u32 flags = 0;
  	int ret = 0;

  	rcu_read_lock();
  	sta = sta_info_get(sdata, peer);
  
  	/* infer the initiator if we can, to support old userspace */

  	switch (action_code) {
  	case WLAN_TDLS_SETUP_REQUEST:

  		if (sta) {

  			set_sta_flag(sta, WLAN_STA_TDLS_INITIATOR);

  			sta->sta.tdls_initiator = false;
  		}

  		/* fall-through */

  	case WLAN_TDLS_SETUP_CONFIRM:

  	case WLAN_TDLS_DISCOVERY_REQUEST:

  		initiator = true;

  		break;
  	case WLAN_TDLS_SETUP_RESPONSE:

  		/*
  		 * In some testing scenarios, we send a request and response.
  		 * Make the last packet sent take effect for the initiator
  		 * value.
  		 */

  		if (sta) {

  			clear_sta_flag(sta, WLAN_STA_TDLS_INITIATOR);

  			sta->sta.tdls_initiator = true;
  		}

  		/* fall-through */

  	case WLAN_PUB_ACTION_TDLS_DISCOVER_RES:

  		initiator = false;

  		break;
  	case WLAN_TDLS_TEARDOWN:

  	case WLAN_TDLS_CHANNEL_SWITCH_REQUEST:

  	case WLAN_TDLS_CHANNEL_SWITCH_RESPONSE:

  		/* any value is ok */

  		break;
  	default:
  		ret = -ENOTSUPP;

  		break;

  	}

  	if (sta && test_sta_flag(sta, WLAN_STA_TDLS_INITIATOR))
  		initiator = true;

  	rcu_read_unlock();
  	if (ret < 0)
  		goto fail;

  	skb = ieee80211_tdls_build_mgmt_packet_data(sdata, peer, action_code,
  						    dialog_token, status_code,
  						    initiator, extra_ies,
  						    extra_ies_len, oper_class,
  						    chandef);
  	if (!skb) {
  		ret = -EINVAL;
  		goto fail;
  	}
  
  	if (action_code == WLAN_PUB_ACTION_TDLS_DISCOVER_RES) {

  		ieee80211_tx_skb(sdata, skb);
  		return 0;
  	}
  
  	/*
  	 * According to 802.11z: Setup req/resp are sent in AC_BK, otherwise
  	 * we should default to AC_VI.
  	 */
  	switch (action_code) {
  	case WLAN_TDLS_SETUP_REQUEST:
  	case WLAN_TDLS_SETUP_RESPONSE:

  		skb->priority = 256 + 2;

  		break;
  	default:

  		skb->priority = 256 + 5;

  		break;
  	}

  	skb_set_queue_mapping(skb, ieee80211_select_queue(sdata, skb));

  	/*
  	 * Set the WLAN_TDLS_TEARDOWN flag to indicate a teardown in progress.
  	 * Later, if no ACK is returned from peer, we will re-send the teardown
  	 * packet through the AP.
  	 */
  	if ((action_code == WLAN_TDLS_TEARDOWN) &&

  	    ieee80211_hw_check(&sdata->local->hw, REPORTS_TX_ACK_STATUS)) {

  		bool try_resend; /* Should we keep skb for possible resend */
  
  		/* If not sending directly to peer - no point in keeping skb */
  		rcu_read_lock();
  		sta = sta_info_get(sdata, peer);
  		try_resend = sta && test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH);
  		rcu_read_unlock();
  
  		spin_lock_bh(&sdata->u.mgd.teardown_lock);
  		if (try_resend && !sdata->u.mgd.teardown_skb) {
  			/* Mark it as requiring TX status callback  */
  			flags |= IEEE80211_TX_CTL_REQ_TX_STATUS |
  				 IEEE80211_TX_INTFL_MLME_CONN_TX;
  
  			/*
  			 * skb is copied since mac80211 will later set
  			 * properties that might not be the same as the AP,
  			 * such as encryption, QoS, addresses, etc.
  			 *
  			 * No problem if skb_copy() fails, so no need to check.
  			 */
  			sdata->u.mgd.teardown_skb = skb_copy(skb, GFP_ATOMIC);
  			sdata->u.mgd.orig_teardown_skb = skb;
  		}
  		spin_unlock_bh(&sdata->u.mgd.teardown_lock);
  	}

  	/* disable bottom halves when entering the Tx path */
  	local_bh_disable();

  	__ieee80211_subif_start_xmit(skb, dev, flags);

  	local_bh_enable();
  
  	return ret;
  
  fail:
  	dev_kfree_skb(skb);
  	return ret;
  }

  static int
  ieee80211_tdls_mgmt_setup(struct wiphy *wiphy, struct net_device *dev,
  			  const u8 *peer, u8 action_code, u8 dialog_token,
  			  u16 status_code, u32 peer_capability, bool initiator,
  			  const u8 *extra_ies, size_t extra_ies_len)

  {
  	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
  	struct ieee80211_local *local = sdata->local;

  	enum ieee80211_smps_mode smps_mode = sdata->u.mgd.driver_smps_mode;

  	int ret;

  	/* don't support setup with forced SMPS mode that's not off */
  	if (smps_mode != IEEE80211_SMPS_AUTOMATIC &&
  	    smps_mode != IEEE80211_SMPS_OFF) {
  		tdls_dbg(sdata, "Aborting TDLS setup due to SMPS mode %d
  ",
  			 smps_mode);
  		return -ENOTSUPP;
  	}

  	mutex_lock(&local->mtx);
  
  	/* we don't support concurrent TDLS peer setups */

  	if (!is_zero_ether_addr(sdata->u.mgd.tdls_peer) &&
  	    !ether_addr_equal(sdata->u.mgd.tdls_peer, peer)) {

  		ret = -EBUSY;

  		goto out_unlock;

  	}

  	/*
  	 * make sure we have a STA representing the peer so we drop or buffer
  	 * non-TDLS-setup frames to the peer. We can't send other packets

  	 * during setup through the AP path.
  	 * Allow error packets to be sent - sometimes we don't even add a STA
  	 * before failing the setup.

  	 */

  	if (status_code == 0) {
  		rcu_read_lock();
  		if (!sta_info_get(sdata, peer)) {
  			rcu_read_unlock();
  			ret = -ENOLINK;

  			goto out_unlock;

  		}

  		rcu_read_unlock();

  	}

  	ieee80211_flush_queues(local, sdata, false);

  	memcpy(sdata->u.mgd.tdls_peer, peer, ETH_ALEN);
  	mutex_unlock(&local->mtx);

  	/* we cannot take the mutex while preparing the setup packet */

  	ret = ieee80211_tdls_prep_mgmt_packet(wiphy, dev, peer, action_code,
  					      dialog_token, status_code,

  					      peer_capability, initiator,

  					      extra_ies, extra_ies_len, 0,
  					      NULL);

  	if (ret < 0) {
  		mutex_lock(&local->mtx);
  		eth_zero_addr(sdata->u.mgd.tdls_peer);
  		mutex_unlock(&local->mtx);
  		return ret;
  	}

  	ieee80211_queue_delayed_work(&sdata->local->hw,

  				     &sdata->u.mgd.tdls_peer_del_work,

  				     TDLS_PEER_SETUP_TIMEOUT);

  	return 0;

  out_unlock:

  	mutex_unlock(&local->mtx);

  	return ret;
  }

  static int
  ieee80211_tdls_mgmt_teardown(struct wiphy *wiphy, struct net_device *dev,
  			     const u8 *peer, u8 action_code, u8 dialog_token,
  			     u16 status_code, u32 peer_capability,
  			     bool initiator, const u8 *extra_ies,
  			     size_t extra_ies_len)
  {
  	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
  	struct ieee80211_local *local = sdata->local;
  	struct sta_info *sta;
  	int ret;
  
  	/*
  	 * No packets can be transmitted to the peer via the AP during setup -
  	 * the STA is set as a TDLS peer, but is not authorized.
  	 * During teardown, we prevent direct transmissions by stopping the
  	 * queues and flushing all direct packets.
  	 */
  	ieee80211_stop_vif_queues(local, sdata,
  				  IEEE80211_QUEUE_STOP_REASON_TDLS_TEARDOWN);

  	ieee80211_flush_queues(local, sdata, false);

  
  	ret = ieee80211_tdls_prep_mgmt_packet(wiphy, dev, peer, action_code,
  					      dialog_token, status_code,
  					      peer_capability, initiator,

  					      extra_ies, extra_ies_len, 0,
  					      NULL);

  	if (ret < 0)
  		sdata_err(sdata, "Failed sending TDLS teardown packet %d
  ",
  			  ret);
  
  	/*
  	 * Remove the STA AUTH flag to force further traffic through the AP. If
  	 * the STA was unreachable, it was already removed.
  	 */
  	rcu_read_lock();
  	sta = sta_info_get(sdata, peer);
  	if (sta)
  		clear_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH);
  	rcu_read_unlock();
  
  	ieee80211_wake_vif_queues(local, sdata,
  				  IEEE80211_QUEUE_STOP_REASON_TDLS_TEARDOWN);
  
  	return 0;
  }

  int ieee80211_tdls_mgmt(struct wiphy *wiphy, struct net_device *dev,
  			const u8 *peer, u8 action_code, u8 dialog_token,
  			u16 status_code, u32 peer_capability,
  			bool initiator, const u8 *extra_ies,
  			size_t extra_ies_len)
  {
  	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
  	int ret;
  
  	if (!(wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS))
  		return -ENOTSUPP;
  
  	/* make sure we are in managed mode, and associated */
  	if (sdata->vif.type != NL80211_IFTYPE_STATION ||
  	    !sdata->u.mgd.associated)
  		return -EINVAL;
  
  	switch (action_code) {
  	case WLAN_TDLS_SETUP_REQUEST:
  	case WLAN_TDLS_SETUP_RESPONSE:
  		ret = ieee80211_tdls_mgmt_setup(wiphy, dev, peer, action_code,
  						dialog_token, status_code,
  						peer_capability, initiator,
  						extra_ies, extra_ies_len);
  		break;
  	case WLAN_TDLS_TEARDOWN:

  		ret = ieee80211_tdls_mgmt_teardown(wiphy, dev, peer,
  						   action_code, dialog_token,
  						   status_code,
  						   peer_capability, initiator,
  						   extra_ies, extra_ies_len);
  		break;

  	case WLAN_TDLS_DISCOVERY_REQUEST:

  		/*
  		 * Protect the discovery so we can hear the TDLS discovery
  		 * response frame. It is transmitted directly and not buffered
  		 * by the AP.
  		 */
  		drv_mgd_protect_tdls_discover(sdata->local, sdata);
  		/* fall-through */
  	case WLAN_TDLS_SETUP_CONFIRM:

  	case WLAN_PUB_ACTION_TDLS_DISCOVER_RES:
  		/* no special handling */
  		ret = ieee80211_tdls_prep_mgmt_packet(wiphy, dev, peer,
  						      action_code,
  						      dialog_token,
  						      status_code,
  						      peer_capability,
  						      initiator, extra_ies,

  						      extra_ies_len, 0, NULL);

  		break;
  	default:
  		ret = -EOPNOTSUPP;
  		break;
  	}

  
  	tdls_dbg(sdata, "TDLS mgmt action %d peer %pM status %d
  ",
  		 action_code, peer, ret);
  	return ret;
  }

  static void iee80211_tdls_recalc_chanctx(struct ieee80211_sub_if_data *sdata,
  					 struct sta_info *sta)

  {
  	struct ieee80211_local *local = sdata->local;
  	struct ieee80211_chanctx_conf *conf;
  	struct ieee80211_chanctx *ctx;

  	enum nl80211_chan_width width;
  	struct ieee80211_supported_band *sband;

  
  	mutex_lock(&local->chanctx_mtx);
  	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
  					 lockdep_is_held(&local->chanctx_mtx));
  	if (conf) {

  		width = conf->def.width;
  		sband = local->hw.wiphy->bands[conf->def.chan->band];

  		ctx = container_of(conf, struct ieee80211_chanctx, conf);
  		ieee80211_recalc_chanctx_chantype(local, ctx);

  
  		/* if width changed and a peer is given, update its BW */
  		if (width != conf->def.width && sta &&
  		    test_sta_flag(sta, WLAN_STA_TDLS_WIDER_BW)) {
  			enum ieee80211_sta_rx_bandwidth bw;
  
  			bw = ieee80211_chan_width_to_rx_bw(conf->def.width);
  			bw = min(bw, ieee80211_sta_cap_rx_bw(sta));
  			if (bw != sta->sta.bandwidth) {
  				sta->sta.bandwidth = bw;
  				rate_control_rate_update(local, sband, sta,
  							 IEEE80211_RC_BW_CHANGED);
  				/*
  				 * if a TDLS peer BW was updated, we need to
  				 * recalc the chandef width again, to get the
  				 * correct chanctx min_def
  				 */
  				ieee80211_recalc_chanctx_chantype(local, ctx);
  			}
  		}

  	}
  	mutex_unlock(&local->chanctx_mtx);
  }

  static int iee80211_tdls_have_ht_peers(struct ieee80211_sub_if_data *sdata)
  {
  	struct sta_info *sta;
  	bool result = false;
  
  	rcu_read_lock();
  	list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) {
  		if (!sta->sta.tdls || sta->sdata != sdata || !sta->uploaded ||
  		    !test_sta_flag(sta, WLAN_STA_AUTHORIZED) ||
  		    !test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH) ||
  		    !sta->sta.ht_cap.ht_supported)
  			continue;
  		result = true;
  		break;
  	}
  	rcu_read_unlock();
  
  	return result;
  }
  
  static void
  iee80211_tdls_recalc_ht_protection(struct ieee80211_sub_if_data *sdata,
  				   struct sta_info *sta)
  {
  	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
  	bool tdls_ht;
  	u16 protection = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED |
  			 IEEE80211_HT_OP_MODE_NON_GF_STA_PRSNT |
  			 IEEE80211_HT_OP_MODE_NON_HT_STA_PRSNT;
  	u16 opmode;
  
  	/* Nothing to do if the BSS connection uses HT */
  	if (!(ifmgd->flags & IEEE80211_STA_DISABLE_HT))
  		return;
  
  	tdls_ht = (sta && sta->sta.ht_cap.ht_supported) ||
  		  iee80211_tdls_have_ht_peers(sdata);
  
  	opmode = sdata->vif.bss_conf.ht_operation_mode;
  
  	if (tdls_ht)
  		opmode |= protection;
  	else
  		opmode &= ~protection;
  
  	if (opmode == sdata->vif.bss_conf.ht_operation_mode)
  		return;
  
  	sdata->vif.bss_conf.ht_operation_mode = opmode;
  	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_HT);
  }

  int ieee80211_tdls_oper(struct wiphy *wiphy, struct net_device *dev,

  			const u8 *peer, enum nl80211_tdls_operation oper)

  {
  	struct sta_info *sta;
  	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);

  	struct ieee80211_local *local = sdata->local;
  	int ret;

  
  	if (!(wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS))
  		return -ENOTSUPP;
  
  	if (sdata->vif.type != NL80211_IFTYPE_STATION)
  		return -EINVAL;

  	switch (oper) {
  	case NL80211_TDLS_ENABLE_LINK:
  	case NL80211_TDLS_DISABLE_LINK:
  		break;
  	case NL80211_TDLS_TEARDOWN:
  	case NL80211_TDLS_SETUP:
  	case NL80211_TDLS_DISCOVERY_REQ:
  		/* We don't support in-driver setup/teardown/discovery */
  		return -ENOTSUPP;
  	}

  	/* protect possible bss_conf changes and avoid concurrency in
  	 * ieee80211_bss_info_change_notify()
  	 */
  	sdata_lock(sdata);

  	mutex_lock(&local->mtx);

  	tdls_dbg(sdata, "TDLS oper %d peer %pM
  ", oper, peer);
  
  	switch (oper) {
  	case NL80211_TDLS_ENABLE_LINK:

  		if (sdata->vif.csa_active) {
  			tdls_dbg(sdata, "TDLS: disallow link during CSA
  ");
  			ret = -EBUSY;
  			break;
  		}

  		mutex_lock(&local->sta_mtx);

  		sta = sta_info_get(sdata, peer);
  		if (!sta) {

  			mutex_unlock(&local->sta_mtx);

  			ret = -ENOLINK;
  			break;

  		}

  		iee80211_tdls_recalc_chanctx(sdata, sta);

  		iee80211_tdls_recalc_ht_protection(sdata, sta);

  		set_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH);

  		mutex_unlock(&local->sta_mtx);

  		WARN_ON_ONCE(is_zero_ether_addr(sdata->u.mgd.tdls_peer) ||
  			     !ether_addr_equal(sdata->u.mgd.tdls_peer, peer));

  		ret = 0;

  		break;
  	case NL80211_TDLS_DISABLE_LINK:

  		/*
  		 * The teardown message in ieee80211_tdls_mgmt_teardown() was
  		 * created while the queues were stopped, so it might still be
  		 * pending. Before flushing the queues we need to be sure the
  		 * message is handled by the tasklet handling pending messages,
  		 * otherwise we might start destroying the station before
  		 * sending the teardown packet.
  		 * Note that this only forces the tasklet to flush pendings -
  		 * not to stop the tasklet from rescheduling itself.
  		 */
  		tasklet_kill(&local->tx_pending_tasklet);

  		/* flush a potentially queued teardown packet */

  		ieee80211_flush_queues(local, sdata, false);

  		ret = sta_info_destroy_addr(sdata, peer);

  
  		mutex_lock(&local->sta_mtx);
  		iee80211_tdls_recalc_ht_protection(sdata, NULL);
  		mutex_unlock(&local->sta_mtx);

  		iee80211_tdls_recalc_chanctx(sdata, NULL);

  		break;

  	default:

  		ret = -ENOTSUPP;
  		break;

  	}

  	if (ret == 0 && ether_addr_equal(sdata->u.mgd.tdls_peer, peer)) {
  		cancel_delayed_work(&sdata->u.mgd.tdls_peer_del_work);
  		eth_zero_addr(sdata->u.mgd.tdls_peer);

  	}

  	if (ret == 0)
  		ieee80211_queue_work(&sdata->local->hw,
  				     &sdata->u.mgd.request_smps_work);

  	mutex_unlock(&local->mtx);

  	sdata_unlock(sdata);

  	return ret;

  }

  
  void ieee80211_tdls_oper_request(struct ieee80211_vif *vif, const u8 *peer,
  				 enum nl80211_tdls_operation oper,
  				 u16 reason_code, gfp_t gfp)
  {
  	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
  
  	if (vif->type != NL80211_IFTYPE_STATION || !vif->bss_conf.assoc) {
  		sdata_err(sdata, "Discarding TDLS oper %d - not STA or disconnected
  ",
  			  oper);
  		return;
  	}
  
  	cfg80211_tdls_oper_request(sdata->dev, peer, oper, reason_code, gfp);
  }
  EXPORT_SYMBOL(ieee80211_tdls_oper_request);

  
  static void
  iee80211_tdls_add_ch_switch_timing(u8 *buf, u16 switch_time, u16 switch_timeout)
  {
  	struct ieee80211_ch_switch_timing *ch_sw;
  
  	*buf++ = WLAN_EID_CHAN_SWITCH_TIMING;
  	*buf++ = sizeof(struct ieee80211_ch_switch_timing);
  
  	ch_sw = (void *)buf;
  	ch_sw->switch_time = cpu_to_le16(switch_time);
  	ch_sw->switch_timeout = cpu_to_le16(switch_timeout);
  }
  
  /* find switch timing IE in SKB ready for Tx */
  static const u8 *ieee80211_tdls_find_sw_timing_ie(struct sk_buff *skb)
  {
  	struct ieee80211_tdls_data *tf;
  	const u8 *ie_start;
  
  	/*
  	 * Get the offset for the new location of the switch timing IE.
  	 * The SKB network header will now point to the "payload_type"
  	 * element of the TDLS data frame struct.
  	 */
  	tf = container_of(skb->data + skb_network_offset(skb),
  			  struct ieee80211_tdls_data, payload_type);
  	ie_start = tf->u.chan_switch_req.variable;
  	return cfg80211_find_ie(WLAN_EID_CHAN_SWITCH_TIMING, ie_start,
  				skb->len - (ie_start - skb->data));
  }
  
  static struct sk_buff *
  ieee80211_tdls_ch_sw_tmpl_get(struct sta_info *sta, u8 oper_class,
  			      struct cfg80211_chan_def *chandef,
  			      u32 *ch_sw_tm_ie_offset)
  {
  	struct ieee80211_sub_if_data *sdata = sta->sdata;
  	u8 extra_ies[2 + sizeof(struct ieee80211_sec_chan_offs_ie) +
  		     2 + sizeof(struct ieee80211_ch_switch_timing)];
  	int extra_ies_len = 2 + sizeof(struct ieee80211_ch_switch_timing);
  	u8 *pos = extra_ies;
  	struct sk_buff *skb;
  
  	/*
  	 * if chandef points to a wide channel add a Secondary-Channel
  	 * Offset information element
  	 */
  	if (chandef->width == NL80211_CHAN_WIDTH_40) {
  		struct ieee80211_sec_chan_offs_ie *sec_chan_ie;
  		bool ht40plus;
  
  		*pos++ = WLAN_EID_SECONDARY_CHANNEL_OFFSET;
  		*pos++ = sizeof(*sec_chan_ie);
  		sec_chan_ie = (void *)pos;
  
  		ht40plus = cfg80211_get_chandef_type(chandef) ==
  							NL80211_CHAN_HT40PLUS;
  		sec_chan_ie->sec_chan_offs = ht40plus ?
  					     IEEE80211_HT_PARAM_CHA_SEC_ABOVE :
  					     IEEE80211_HT_PARAM_CHA_SEC_BELOW;
  		pos += sizeof(*sec_chan_ie);
  
  		extra_ies_len += 2 + sizeof(struct ieee80211_sec_chan_offs_ie);
  	}
  
  	/* just set the values to 0, this is a template */
  	iee80211_tdls_add_ch_switch_timing(pos, 0, 0);
  
  	skb = ieee80211_tdls_build_mgmt_packet_data(sdata, sta->sta.addr,
  					      WLAN_TDLS_CHANNEL_SWITCH_REQUEST,
  					      0, 0, !sta->sta.tdls_initiator,
  					      extra_ies, extra_ies_len,
  					      oper_class, chandef);
  	if (!skb)
  		return NULL;
  
  	skb = ieee80211_build_data_template(sdata, skb, 0);
  	if (IS_ERR(skb)) {
  		tdls_dbg(sdata, "Failed building TDLS channel switch frame
  ");
  		return NULL;
  	}
  
  	if (ch_sw_tm_ie_offset) {
  		const u8 *tm_ie = ieee80211_tdls_find_sw_timing_ie(skb);
  
  		if (!tm_ie) {
  			tdls_dbg(sdata, "No switch timing IE in TDLS switch
  ");
  			dev_kfree_skb_any(skb);
  			return NULL;
  		}
  
  		*ch_sw_tm_ie_offset = tm_ie - skb->data;
  	}
  
  	tdls_dbg(sdata,
  		 "TDLS channel switch request template for %pM ch %d width %d
  ",
  		 sta->sta.addr, chandef->chan->center_freq, chandef->width);
  	return skb;
  }
  
  int
  ieee80211_tdls_channel_switch(struct wiphy *wiphy, struct net_device *dev,
  			      const u8 *addr, u8 oper_class,
  			      struct cfg80211_chan_def *chandef)
  {
  	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
  	struct ieee80211_local *local = sdata->local;
  	struct sta_info *sta;
  	struct sk_buff *skb = NULL;
  	u32 ch_sw_tm_ie;
  	int ret;
  
  	mutex_lock(&local->sta_mtx);
  	sta = sta_info_get(sdata, addr);
  	if (!sta) {
  		tdls_dbg(sdata,
  			 "Invalid TDLS peer %pM for channel switch request
  ",
  			 addr);
  		ret = -ENOENT;
  		goto out;
  	}
  
  	if (!test_sta_flag(sta, WLAN_STA_TDLS_CHAN_SWITCH)) {
  		tdls_dbg(sdata, "TDLS channel switch unsupported by %pM
  ",
  			 addr);
  		ret = -ENOTSUPP;
  		goto out;
  	}
  
  	skb = ieee80211_tdls_ch_sw_tmpl_get(sta, oper_class, chandef,
  					    &ch_sw_tm_ie);
  	if (!skb) {
  		ret = -ENOENT;
  		goto out;
  	}
  
  	ret = drv_tdls_channel_switch(local, sdata, &sta->sta, oper_class,
  				      chandef, skb, ch_sw_tm_ie);
  	if (!ret)
  		set_sta_flag(sta, WLAN_STA_TDLS_OFF_CHANNEL);
  
  out:
  	mutex_unlock(&local->sta_mtx);
  	dev_kfree_skb_any(skb);
  	return ret;
  }
  
  void
  ieee80211_tdls_cancel_channel_switch(struct wiphy *wiphy,
  				     struct net_device *dev,
  				     const u8 *addr)
  {
  	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
  	struct ieee80211_local *local = sdata->local;
  	struct sta_info *sta;
  
  	mutex_lock(&local->sta_mtx);
  	sta = sta_info_get(sdata, addr);
  	if (!sta) {
  		tdls_dbg(sdata,
  			 "Invalid TDLS peer %pM for channel switch cancel
  ",
  			 addr);
  		goto out;
  	}
  
  	if (!test_sta_flag(sta, WLAN_STA_TDLS_OFF_CHANNEL)) {
  		tdls_dbg(sdata, "TDLS channel switch not initiated by %pM
  ",
  			 addr);
  		goto out;
  	}
  
  	drv_tdls_cancel_channel_switch(local, sdata, &sta->sta);
  	clear_sta_flag(sta, WLAN_STA_TDLS_OFF_CHANNEL);
  
  out:
  	mutex_unlock(&local->sta_mtx);
  }

  
  static struct sk_buff *
  ieee80211_tdls_ch_sw_resp_tmpl_get(struct sta_info *sta,
  				   u32 *ch_sw_tm_ie_offset)
  {
  	struct ieee80211_sub_if_data *sdata = sta->sdata;
  	struct sk_buff *skb;
  	u8 extra_ies[2 + sizeof(struct ieee80211_ch_switch_timing)];
  
  	/* initial timing are always zero in the template */
  	iee80211_tdls_add_ch_switch_timing(extra_ies, 0, 0);
  
  	skb = ieee80211_tdls_build_mgmt_packet_data(sdata, sta->sta.addr,
  					WLAN_TDLS_CHANNEL_SWITCH_RESPONSE,
  					0, 0, !sta->sta.tdls_initiator,
  					extra_ies, sizeof(extra_ies), 0, NULL);
  	if (!skb)
  		return NULL;
  
  	skb = ieee80211_build_data_template(sdata, skb, 0);
  	if (IS_ERR(skb)) {
  		tdls_dbg(sdata,
  			 "Failed building TDLS channel switch resp frame
  ");
  		return NULL;
  	}
  
  	if (ch_sw_tm_ie_offset) {
  		const u8 *tm_ie = ieee80211_tdls_find_sw_timing_ie(skb);
  
  		if (!tm_ie) {
  			tdls_dbg(sdata,
  				 "No switch timing IE in TDLS switch resp
  ");
  			dev_kfree_skb_any(skb);
  			return NULL;
  		}
  
  		*ch_sw_tm_ie_offset = tm_ie - skb->data;
  	}
  
  	tdls_dbg(sdata, "TDLS get channel switch response template for %pM
  ",
  		 sta->sta.addr);
  	return skb;
  }
  
  static int
  ieee80211_process_tdls_channel_switch_resp(struct ieee80211_sub_if_data *sdata,
  					   struct sk_buff *skb)
  {
  	struct ieee80211_local *local = sdata->local;
  	struct ieee802_11_elems elems;
  	struct sta_info *sta;
  	struct ieee80211_tdls_data *tf = (void *)skb->data;
  	bool local_initiator;
  	struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
  	int baselen = offsetof(typeof(*tf), u.chan_switch_resp.variable);
  	struct ieee80211_tdls_ch_sw_params params = {};
  	int ret;
  
  	params.action_code = WLAN_TDLS_CHANNEL_SWITCH_RESPONSE;
  	params.timestamp = rx_status->device_timestamp;
  
  	if (skb->len < baselen) {
  		tdls_dbg(sdata, "TDLS channel switch resp too short: %d
  ",
  			 skb->len);
  		return -EINVAL;
  	}
  
  	mutex_lock(&local->sta_mtx);
  	sta = sta_info_get(sdata, tf->sa);
  	if (!sta || !test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH)) {
  		tdls_dbg(sdata, "TDLS chan switch from non-peer sta %pM
  ",
  			 tf->sa);
  		ret = -EINVAL;
  		goto out;
  	}
  
  	params.sta = &sta->sta;
  	params.status = le16_to_cpu(tf->u.chan_switch_resp.status_code);
  	if (params.status != 0) {
  		ret = 0;
  		goto call_drv;
  	}
  
  	ieee802_11_parse_elems(tf->u.chan_switch_resp.variable,
  			       skb->len - baselen, false, &elems);
  	if (elems.parse_error) {
  		tdls_dbg(sdata, "Invalid IEs in TDLS channel switch resp
  ");
  		ret = -EINVAL;
  		goto out;
  	}
  
  	if (!elems.ch_sw_timing || !elems.lnk_id) {
  		tdls_dbg(sdata, "TDLS channel switch resp - missing IEs
  ");
  		ret = -EINVAL;
  		goto out;
  	}
  
  	/* validate the initiator is set correctly */
  	local_initiator =
  		!memcmp(elems.lnk_id->init_sta, sdata->vif.addr, ETH_ALEN);
  	if (local_initiator == sta->sta.tdls_initiator) {
  		tdls_dbg(sdata, "TDLS chan switch invalid lnk-id initiator
  ");
  		ret = -EINVAL;
  		goto out;
  	}
  
  	params.switch_time = le16_to_cpu(elems.ch_sw_timing->switch_time);
  	params.switch_timeout = le16_to_cpu(elems.ch_sw_timing->switch_timeout);
  
  	params.tmpl_skb =
  		ieee80211_tdls_ch_sw_resp_tmpl_get(sta, &params.ch_sw_tm_ie);
  	if (!params.tmpl_skb) {
  		ret = -ENOENT;
  		goto out;
  	}

  	ret = 0;

  call_drv:
  	drv_tdls_recv_channel_switch(sdata->local, sdata, &params);
  
  	tdls_dbg(sdata,
  		 "TDLS channel switch response received from %pM status %d
  ",
  		 tf->sa, params.status);
  
  out:
  	mutex_unlock(&local->sta_mtx);
  	dev_kfree_skb_any(params.tmpl_skb);
  	return ret;
  }
  
  static int
  ieee80211_process_tdls_channel_switch_req(struct ieee80211_sub_if_data *sdata,
  					  struct sk_buff *skb)
  {
  	struct ieee80211_local *local = sdata->local;
  	struct ieee802_11_elems elems;
  	struct cfg80211_chan_def chandef;
  	struct ieee80211_channel *chan;
  	enum nl80211_channel_type chan_type;
  	int freq;
  	u8 target_channel, oper_class;
  	bool local_initiator;
  	struct sta_info *sta;

  	enum nl80211_band band;

  	struct ieee80211_tdls_data *tf = (void *)skb->data;
  	struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
  	int baselen = offsetof(typeof(*tf), u.chan_switch_req.variable);
  	struct ieee80211_tdls_ch_sw_params params = {};
  	int ret = 0;
  
  	params.action_code = WLAN_TDLS_CHANNEL_SWITCH_REQUEST;
  	params.timestamp = rx_status->device_timestamp;
  
  	if (skb->len < baselen) {
  		tdls_dbg(sdata, "TDLS channel switch req too short: %d
  ",
  			 skb->len);
  		return -EINVAL;
  	}
  
  	target_channel = tf->u.chan_switch_req.target_channel;
  	oper_class = tf->u.chan_switch_req.oper_class;
  
  	/*
  	 * We can't easily infer the channel band. The operating class is
  	 * ambiguous - there are multiple tables (US/Europe/JP/Global). The
  	 * solution here is to treat channels with number >14 as 5GHz ones,
  	 * and specifically check for the (oper_class, channel) combinations
  	 * where this doesn't hold. These are thankfully unique according to
  	 * IEEE802.11-2012.
  	 * We consider only the 2GHz and 5GHz bands and 20MHz+ channels as
  	 * valid here.
  	 */
  	if ((oper_class == 112 || oper_class == 2 || oper_class == 3 ||
  	     oper_class == 4 || oper_class == 5 || oper_class == 6) &&
  	     target_channel < 14)

  		band = NL80211_BAND_5GHZ;

  	else

  		band = target_channel < 14 ? NL80211_BAND_2GHZ :
  					     NL80211_BAND_5GHZ;

  
  	freq = ieee80211_channel_to_frequency(target_channel, band);
  	if (freq == 0) {
  		tdls_dbg(sdata, "Invalid channel in TDLS chan switch: %d
  ",
  			 target_channel);
  		return -EINVAL;
  	}
  
  	chan = ieee80211_get_channel(sdata->local->hw.wiphy, freq);
  	if (!chan) {
  		tdls_dbg(sdata,
  			 "Unsupported channel for TDLS chan switch: %d
  ",
  			 target_channel);
  		return -EINVAL;
  	}
  
  	ieee802_11_parse_elems(tf->u.chan_switch_req.variable,
  			       skb->len - baselen, false, &elems);
  	if (elems.parse_error) {
  		tdls_dbg(sdata, "Invalid IEs in TDLS channel switch req
  ");
  		return -EINVAL;
  	}
  
  	if (!elems.ch_sw_timing || !elems.lnk_id) {
  		tdls_dbg(sdata, "TDLS channel switch req - missing IEs
  ");
  		return -EINVAL;
  	}

  	if (!elems.sec_chan_offs) {
  		chan_type = NL80211_CHAN_HT20;
  	} else {
  		switch (elems.sec_chan_offs->sec_chan_offs) {
  		case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
  			chan_type = NL80211_CHAN_HT40PLUS;
  			break;
  		case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
  			chan_type = NL80211_CHAN_HT40MINUS;
  			break;
  		default:
  			chan_type = NL80211_CHAN_HT20;
  			break;
  		}
  	}
  
  	cfg80211_chandef_create(&chandef, chan, chan_type);
  
  	/* we will be active on the TDLS link */
  	if (!cfg80211_reg_can_beacon_relax(sdata->local->hw.wiphy, &chandef,
  					   sdata->wdev.iftype)) {
  		tdls_dbg(sdata, "TDLS chan switch to forbidden channel
  ");
  		return -EINVAL;
  	}

  	mutex_lock(&local->sta_mtx);
  	sta = sta_info_get(sdata, tf->sa);
  	if (!sta || !test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH)) {
  		tdls_dbg(sdata, "TDLS chan switch from non-peer sta %pM
  ",
  			 tf->sa);
  		ret = -EINVAL;
  		goto out;
  	}
  
  	params.sta = &sta->sta;
  
  	/* validate the initiator is set correctly */
  	local_initiator =
  		!memcmp(elems.lnk_id->init_sta, sdata->vif.addr, ETH_ALEN);
  	if (local_initiator == sta->sta.tdls_initiator) {
  		tdls_dbg(sdata, "TDLS chan switch invalid lnk-id initiator
  ");
  		ret = -EINVAL;
  		goto out;
  	}

  	/* peer should have known better */
  	if (!sta->sta.ht_cap.ht_supported && elems.sec_chan_offs &&
  	    elems.sec_chan_offs->sec_chan_offs) {
  		tdls_dbg(sdata, "TDLS chan switch - wide chan unsupported
  ");
  		ret = -ENOTSUPP;
  		goto out;

  	}

  	params.chandef = &chandef;

  	params.switch_time = le16_to_cpu(elems.ch_sw_timing->switch_time);
  	params.switch_timeout = le16_to_cpu(elems.ch_sw_timing->switch_timeout);
  
  	params.tmpl_skb =
  		ieee80211_tdls_ch_sw_resp_tmpl_get(sta,
  						   &params.ch_sw_tm_ie);
  	if (!params.tmpl_skb) {
  		ret = -ENOENT;
  		goto out;
  	}
  
  	drv_tdls_recv_channel_switch(sdata->local, sdata, &params);
  
  	tdls_dbg(sdata,
  		 "TDLS ch switch request received from %pM ch %d width %d
  ",
  		 tf->sa, params.chandef->chan->center_freq,
  		 params.chandef->width);
  out:
  	mutex_unlock(&local->sta_mtx);
  	dev_kfree_skb_any(params.tmpl_skb);
  	return ret;
  }

  static void
  ieee80211_process_tdls_channel_switch(struct ieee80211_sub_if_data *sdata,
  				      struct sk_buff *skb)

  {
  	struct ieee80211_tdls_data *tf = (void *)skb->data;
  	struct wiphy *wiphy = sdata->local->hw.wiphy;

  	ASSERT_RTNL();

  	/* make sure the driver supports it */
  	if (!(wiphy->features & NL80211_FEATURE_TDLS_CHANNEL_SWITCH))
  		return;
  
  	/* we want to access the entire packet */
  	if (skb_linearize(skb))
  		return;
  	/*
  	 * The packet/size was already validated by mac80211 Rx path, only look
  	 * at the action type.
  	 */
  	switch (tf->action_code) {
  	case WLAN_TDLS_CHANNEL_SWITCH_REQUEST:
  		ieee80211_process_tdls_channel_switch_req(sdata, skb);
  		break;
  	case WLAN_TDLS_CHANNEL_SWITCH_RESPONSE:
  		ieee80211_process_tdls_channel_switch_resp(sdata, skb);
  		break;
  	default:
  		WARN_ON_ONCE(1);
  		return;
  	}
  }

  
  void ieee80211_teardown_tdls_peers(struct ieee80211_sub_if_data *sdata)
  {
  	struct sta_info *sta;
  	u16 reason = WLAN_REASON_TDLS_TEARDOWN_UNSPECIFIED;
  
  	rcu_read_lock();
  	list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) {
  		if (!sta->sta.tdls || sta->sdata != sdata || !sta->uploaded ||
  		    !test_sta_flag(sta, WLAN_STA_AUTHORIZED))
  			continue;
  
  		ieee80211_tdls_oper_request(&sdata->vif, sta->sta.addr,
  					    NL80211_TDLS_TEARDOWN, reason,
  					    GFP_ATOMIC);
  	}
  	rcu_read_unlock();
  }

  
  void ieee80211_tdls_chsw_work(struct work_struct *wk)
  {
  	struct ieee80211_local *local =
  		container_of(wk, struct ieee80211_local, tdls_chsw_work);
  	struct ieee80211_sub_if_data *sdata;
  	struct sk_buff *skb;
  	struct ieee80211_tdls_data *tf;
  
  	rtnl_lock();
  	while ((skb = skb_dequeue(&local->skb_queue_tdls_chsw))) {
  		tf = (struct ieee80211_tdls_data *)skb->data;
  		list_for_each_entry(sdata, &local->interfaces, list) {
  			if (!ieee80211_sdata_running(sdata) ||
  			    sdata->vif.type != NL80211_IFTYPE_STATION ||
  			    !ether_addr_equal(tf->da, sdata->vif.addr))
  				continue;
  
  			ieee80211_process_tdls_channel_switch(sdata, skb);
  			break;
  		}
  
  		kfree_skb(skb);
  	}
  	rtnl_unlock();
  }