Commit 22f66895 authored by Avri Altman's avatar Avri Altman Committed by Johannes Berg
Browse files

mac80211: protect non-HT BSS when HT TDLS traffic exists 



HT TDLS traffic should be protected in a non-HT BSS to avoid
collisions. Therefore, when TDLS peers join/leave, check if
protection is (now) needed and set the ht_operation_mode of
the virtual interface according to the HT capabilities of the
TDLS peer(s).

This works because a non-HT BSS connection never sets (or
otherwise uses) the ht_operation_mode; it just means that
drivers must be aware that this field applies to all HT
traffic for this virtual interface, not just the traffic
within the BSS. Document that.

Signed-off-by: default avatarAvri Altman <avri.altman@intel.com>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 98a1f828

include/net/mac80211.h

+3 −1
Original line number Diff line number Diff line
@@ -477,7 +477,9 @@ struct ieee80211_event { 
 * @chandef: Channel definition for this BSS -- the hardware might be

 *	configured a higher bandwidth than this BSS uses, for example.

 * @ht_operation_mode: HT operation mode like in &struct ieee80211_ht_operation.

 *	This field is only valid when the channel type is one of the HT types.

 *	This field is only valid when the channel is a wide HT/VHT channel.

 *	Note that with TDLS this can be the case (channel is HT, protection must

 *	be used from this field) even when the BSS association isn't using HT.

 * @cqm_rssi_thold: Connection quality monitor RSSI threshold, a zero value

 *	implies disabled

 * @cqm_rssi_hyst: Connection quality monitor RSSI hysteresis

net/mac80211/tdls.c

+67 −3
Original line number Diff line number Diff line
@@ -1249,6 +1249,58 @@ static void iee80211_tdls_recalc_chanctx(struct ieee80211_sub_if_data *sdata) 
	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)

{
@@ -1274,6 +1326,10 @@ int ieee80211_tdls_oper(struct wiphy *wiphy, struct net_device *dev, 
		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\n", oper, peer);
@@ -1287,16 +1343,18 @@ int ieee80211_tdls_oper(struct wiphy *wiphy, struct net_device *dev, 


		iee80211_tdls_recalc_chanctx(sdata);



		rcu_read_lock();

		mutex_lock(&local->sta_mtx);

		sta = sta_info_get(sdata, peer);

		if (!sta) {

			rcu_read_unlock();

			mutex_unlock(&local->sta_mtx);

			ret = -ENOLINK;

			break;

		}



		iee80211_tdls_recalc_ht_protection(sdata, sta);



		set_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH);

		rcu_read_unlock();

		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));
@@ -1318,6 +1376,11 @@ int ieee80211_tdls_oper(struct wiphy *wiphy, struct net_device *dev, 
		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);

		break;

	default:
@@ -1335,6 +1398,7 @@ int ieee80211_tdls_oper(struct wiphy *wiphy, struct net_device *dev, 
				     &sdata->u.mgd.request_smps_work);



	mutex_unlock(&local->mtx);

	sdata_unlock(sdata);

	return ret;

}

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