Commit 3660944a authored by Johannes Berg's avatar Johannes Berg
Browse files

mac80211: disallow band-switch during CSA 



If the AP advertises a band switch during CSA, we will not have
the right information to continue working with it, since it will
likely (have to) change its capabilities and we don't track any
capability changes at all. Additionally, we store e.g. supported
rates per band, and that information would become invalid.

Since this is a fringe scenario, just disconnect explicitly.

Signed-off-by: default avatarLuca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20201129172929.0e2327107c06.I461adb07704e056b054a4a7c29b80c95a9f56637@changeid


Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 98507424

net/mac80211/mlme.c

+15 −3
Original line number Diff line number Diff line
@@ -1417,6 +1417,17 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata, 
		return;

	}



	if (sdata->vif.bss_conf.chandef.chan->band !=

	    csa_ie.chandef.chan->band) {

		sdata_info(sdata,

			   "AP %pM switches to different band (%d MHz, width:%d, CF1/2: %d/%d MHz), disconnecting\n",

			   ifmgd->associated->bssid,

			   csa_ie.chandef.chan->center_freq,

			   csa_ie.chandef.width, csa_ie.chandef.center_freq1,

			   csa_ie.chandef.center_freq2);

		goto lock_and_drop_connection;

	}



	if (!cfg80211_chandef_usable(local->hw.wiphy, &csa_ie.chandef,

				     IEEE80211_CHAN_DISABLED)) {

		sdata_info(sdata,
@@ -1429,9 +1440,7 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata, 
			   csa_ie.chandef.width, csa_ie.chandef.center_freq1,

			   csa_ie.chandef.freq1_offset,

			   csa_ie.chandef.center_freq2);

		ieee80211_queue_work(&local->hw,

				     &ifmgd->csa_connection_drop_work);

		return;

		goto lock_and_drop_connection;

	}



	if (cfg80211_chandef_identical(&csa_ie.chandef,
@@ -1516,6 +1525,9 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata, 
			  TU_TO_EXP_TIME((csa_ie.count - 1) *

					 cbss->beacon_interval));

	return;

 lock_and_drop_connection:

	mutex_lock(&local->mtx);

	mutex_lock(&local->chanctx_mtx);

 drop_connection:

	/*

	 * This is just so that the disconnect flow will know that