Commit c5a71688 authored by Arik Nemtsov's avatar Arik Nemtsov Committed by Johannes Berg
Browse files

mac80211: disconnect TDLS stations on STA CSA 



When a station does a channel switch, it's not well defined what its TDLS
peers would do. Avoid a situation when the local side marks a potentially
disconnected peer as a TDLS peer.
Keeping peers connected through CSA is doubly problematic with the upcoming
TDLS WIDER-BW feature which allows peers to widen the BSS channel. The
new channel transitioned-to might not be compatible and would require
a re-negotiation anyway.

Make sure to disallow new TDLS link during CSA.

Signed-off-by: default avatarArik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: default avatarEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 464daaf0

net/mac80211/mlme.c

+26 −0
Original line number Diff line number Diff line
@@ -1098,6 +1098,24 @@ static void ieee80211_chswitch_timer(unsigned long data) 
	ieee80211_queue_work(&sdata->local->hw, &sdata->u.mgd.chswitch_work);

}



static 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();

}



static void

ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,

				 u64 timestamp, u32 device_timestamp,
@@ -1161,6 +1179,14 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata, 
		return;

	}



	/*

	 * Drop all TDLS peers - either we disconnect or move to a different

	 * channel from this point on. There's no telling what our peer will do.

	 * The TDLS WIDER_BW scenario is also problematic, as peers might now

	 * have an incompatible wider chandef.

	 */

	ieee80211_teardown_tdls_peers(sdata);



	mutex_lock(&local->mtx);

	mutex_lock(&local->chanctx_mtx);

	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,

net/mac80211/tdls.c

+6 −0
Original line number Diff line number Diff line
@@ -1183,6 +1183,12 @@ int ieee80211_tdls_oper(struct wiphy *wiphy, struct net_device *dev, 


	switch (oper) {

	case NL80211_TDLS_ENABLE_LINK:

		if (sdata->vif.csa_active) {

			tdls_dbg(sdata, "TDLS: disallow link during CSA\n");

			ret = -EBUSY;

			break;

		}



		rcu_read_lock();

		sta = sta_info_get(sdata, peer);

		if (!sta) {

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