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Commit cd64f2a9 authored by Johannes Berg's avatar Johannes Berg
Browse files

mac80211: handle wide bandwidth channel switch 



Parse and react to the wide bandwidth channel switch element
in beacons/action frames. Finding the element was done in a
previous patch (it has different positions in beacons/action
frames), now handle it. If there's something wrong with it
simply disconnect.

Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent b2e506bf

net/mac80211/mlme.c

+79 −17
Original line number Diff line number Diff line
@@ -1027,7 +1027,11 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata, 
	u8 new_chan_no;

	u8 count;

	u8 mode;

	struct ieee80211_channel *new_chan;

	struct cfg80211_chan_def new_chandef = {};

	struct cfg80211_chan_def new_vht_chandef = {};

	const struct ieee80211_sec_chan_offs_ie *sec_chan_offs;

	const struct ieee80211_wide_bw_chansw_ie *wide_bw_chansw_ie;

	int secondary_channel_offset = -1;



	ASSERT_MGD_MTX(ifmgd);
@@ -1042,18 +1046,17 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata, 
	if (ifmgd->flags & IEEE80211_STA_CSA_RECEIVED)

		return;



	if (!(ifmgd->flags & IEEE80211_STA_DISABLE_HT)) {

		/* if HT is enabled and the IE not present, it's still HT */

		secondary_channel_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE;

		if (elems->sec_chan_offs)

			secondary_channel_offset =

				elems->sec_chan_offs->sec_chan_offs;

	sec_chan_offs = elems->sec_chan_offs;

	wide_bw_chansw_ie = elems->wide_bw_chansw_ie;



	if (ifmgd->flags & (IEEE80211_STA_DISABLE_HT |

			    IEEE80211_STA_DISABLE_40MHZ)) {

		sec_chan_offs = NULL;

		wide_bw_chansw_ie = NULL;

	}



	if (ifmgd->flags & IEEE80211_STA_DISABLE_40MHZ &&

	    (secondary_channel_offset == IEEE80211_HT_PARAM_CHA_SEC_ABOVE ||

	     secondary_channel_offset == IEEE80211_HT_PARAM_CHA_SEC_BELOW))

		secondary_channel_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE;

	if (ifmgd->flags & IEEE80211_STA_DISABLE_VHT)

		wide_bw_chansw_ie = NULL;



	if (elems->ext_chansw_ie) {

		if (!ieee80211_operating_class_to_band(
@@ -1081,9 +1084,8 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata, 
	bss = (void *)cbss->priv;



	new_freq = ieee80211_channel_to_frequency(new_chan_no, new_band);

	new_chandef.chan = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);

	if (!new_chandef.chan ||

	    new_chandef.chan->flags & IEEE80211_CHAN_DISABLED) {

	new_chan = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);

	if (!new_chan || new_chan->flags & IEEE80211_CHAN_DISABLED) {

		sdata_info(sdata,

			   "AP %pM switches to unsupported channel (%d MHz), disconnecting\n",

			   ifmgd->associated->bssid, new_freq);
@@ -1092,27 +1094,87 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata, 
		return;

	}



	if (sec_chan_offs) {

		secondary_channel_offset = sec_chan_offs->sec_chan_offs;

	} else if (!(ifmgd->flags & IEEE80211_STA_DISABLE_HT)) {

		/* if HT is enabled and the IE not present, it's still HT */

		secondary_channel_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE;

	}



	switch (secondary_channel_offset) {

	default:

		/* secondary_channel_offset was present but is invalid */

	case IEEE80211_HT_PARAM_CHA_SEC_NONE:

		cfg80211_chandef_create(&new_chandef, new_chandef.chan,

		cfg80211_chandef_create(&new_chandef, new_chan,

					NL80211_CHAN_HT20);

		break;

	case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:

		cfg80211_chandef_create(&new_chandef, new_chandef.chan,

		cfg80211_chandef_create(&new_chandef, new_chan,

					NL80211_CHAN_HT40PLUS);

		break;

	case IEEE80211_HT_PARAM_CHA_SEC_BELOW:

		cfg80211_chandef_create(&new_chandef, new_chandef.chan,

		cfg80211_chandef_create(&new_chandef, new_chan,

					NL80211_CHAN_HT40MINUS);

		break;

	case -1:

		cfg80211_chandef_create(&new_chandef, new_chandef.chan,

		cfg80211_chandef_create(&new_chandef, new_chan,

					NL80211_CHAN_NO_HT);

		break;

	}



	if (wide_bw_chansw_ie) {

		new_vht_chandef.chan = new_chan;

		new_vht_chandef.center_freq1 =

			ieee80211_channel_to_frequency(

				wide_bw_chansw_ie->new_center_freq_seg0,

				new_band);



		switch (wide_bw_chansw_ie->new_channel_width) {

		default:

			/* hmmm, ignore VHT and use HT if present */

		case IEEE80211_VHT_CHANWIDTH_USE_HT:

			new_vht_chandef.chan = NULL;

			break;

		case IEEE80211_VHT_CHANWIDTH_80MHZ:

			new_vht_chandef.width = NL80211_CHAN_WIDTH_80;

			break;

		case IEEE80211_VHT_CHANWIDTH_160MHZ:

			new_vht_chandef.width = NL80211_CHAN_WIDTH_160;

			break;

		case IEEE80211_VHT_CHANWIDTH_80P80MHZ:

			/* field is otherwise reserved */

			new_vht_chandef.center_freq2 =

				ieee80211_channel_to_frequency(

					wide_bw_chansw_ie->new_center_freq_seg1,

					new_band);

			new_vht_chandef.width = NL80211_CHAN_WIDTH_80P80;

			break;

		}

		if (ifmgd->flags & IEEE80211_STA_DISABLE_80P80MHZ &&

		    new_vht_chandef.width == NL80211_CHAN_WIDTH_80P80)

			chandef_downgrade(&new_vht_chandef);

		if (ifmgd->flags & IEEE80211_STA_DISABLE_160MHZ &&

		    new_vht_chandef.width == NL80211_CHAN_WIDTH_160)

			chandef_downgrade(&new_vht_chandef);

		if (ifmgd->flags & IEEE80211_STA_DISABLE_40MHZ &&

		    new_vht_chandef.width > NL80211_CHAN_WIDTH_20)

			chandef_downgrade(&new_vht_chandef);

	}



	/* if VHT data is there validate & use it */

	if (new_vht_chandef.chan) {

		if (!cfg80211_chandef_compatible(&new_vht_chandef,

						 &new_chandef)) {

			sdata_info(sdata,

				   "AP %pM CSA has inconsistent channel data, disconnecting\n",

				   ifmgd->associated->bssid);

			ieee80211_queue_work(&local->hw,

					     &ifmgd->csa_connection_drop_work);

			return;

		}

		new_chandef = new_vht_chandef;

	}



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

				     IEEE80211_CHAN_DISABLED)) {

		sdata_info(sdata,