[RFC 0/4] mac80211: proper channel switch support

[RFC 0/4] mac80211: proper channel switch support

[Johannes Berg]

The current channel switch support is rather lacking, HT channel switch
isn't even attempted to be handled correctly ... This makes it a bit more
complete, though still lacking VHT and channel context handling.

Does anyone have a test setup for this?

johannes

[RFC 1/4] mac80211: unify CSA action frame/beacon processing

[Johannes Berg]

From: Johannes Berg <johannes.berg@intel.com>

CSA action frame content should be processed as variable IEs
rather than fixed to make it extensible. Unify the code and
process them just like CSA in beacons to make it easier to
extend for HT/VHT.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 include/linux/ieee80211.h  |  4 +--
 net/mac80211/ieee80211_i.h |  4 ---
 net/mac80211/mlme.c        | 71 ++++++++++++++++++++++++++++------------------
 net/mac80211/rx.c          |  4 ---
 4 files changed, 44 insertions(+), 39 deletions(-)

diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index d10b5bb..ba8b10e 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -840,9 +840,7 @@ struct ieee80211_mgmt {
 				} __packed wme_action;
 				struct{
 					u8 action_code;
-					u8 element_id;
-					u8 length;
-					struct ieee80211_channel_sw_ie sw_elem;
+					u8 variable[0];
 				} __packed chan_switch;
 				struct{
 					u8 action_code;
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index f9782f0..bd6ab0e 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1264,10 +1264,6 @@ void ieee80211_recalc_ps_vif(struct ieee80211_sub_if_data *sdata);
 int ieee80211_max_network_latency(struct notifier_block *nb,
 				  unsigned long data, void *dummy);
 int ieee80211_set_arp_filter(struct ieee80211_sub_if_data *sdata);
-void
-ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
-				 const struct ieee80211_channel_sw_ie *sw_elem,
-				 struct ieee80211_bss *bss, u64 timestamp);
 void ieee80211_sta_work(struct ieee80211_sub_if_data *sdata);
 void ieee80211_sta_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 				  struct sk_buff *skb);
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 237e2ef..d266e52 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1054,33 +1054,37 @@ static void ieee80211_chswitch_timer(unsigned long data)
 	ieee80211_queue_work(&sdata->local->hw, &sdata->u.mgd.chswitch_work);
 }
 
-void
+static void
 ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
-				 const struct ieee80211_channel_sw_ie *sw_elem,
-				 struct ieee80211_bss *bss, u64 timestamp)
+				 u64 timestamp, struct ieee802_11_elems *elems)
 {
-	struct cfg80211_bss *cbss =
-		container_of((void *)bss, struct cfg80211_bss, priv);
-	struct ieee80211_channel *new_ch;
 	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
-	int new_freq = ieee80211_channel_to_frequency(sw_elem->new_ch_num,
-						      cbss->channel->band);
+	struct cfg80211_bss *cbss = ifmgd->associated;
+	struct ieee80211_bss *bss;
+	struct ieee80211_channel *new_ch;
+	int new_freq;
 	struct ieee80211_chanctx *chanctx;
 
 	ASSERT_MGD_MTX(ifmgd);
 
-	if (!ifmgd->associated)
+	if (!cbss)
 		return;
 
 	if (sdata->local->scanning)
 		return;
 
-	/* Disregard subsequent beacons if we are already running a timer
-	   processing a CSA */
-
+	/* disregard subsequent announcements if we are already processing */
 	if (ifmgd->flags & IEEE80211_STA_CSA_RECEIVED)
 		return;
 
+	if (!elems->ch_switch_ie)
+		return;
+
+	bss = (void *)cbss->priv;
+
+	new_freq = ieee80211_channel_to_frequency(
+			elems->ch_switch_ie->new_ch_num,
+			cbss->channel->band);
 	new_ch = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
 	if (!new_ch || new_ch->flags & IEEE80211_CHAN_DISABLED) {
 		sdata_info(sdata,
@@ -1120,7 +1124,7 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
 
 	sdata->local->csa_channel = new_ch;
 
-	if (sw_elem->mode)
+	if (elems->ch_switch_ie->mode)
 		ieee80211_stop_queues_by_reason(&sdata->local->hw,
 				IEEE80211_MAX_QUEUE_MAP,
 				IEEE80211_QUEUE_STOP_REASON_CSA);
@@ -1129,9 +1133,9 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
 		/* use driver's channel switch callback */
 		struct ieee80211_channel_switch ch_switch = {
 			.timestamp = timestamp,
-			.block_tx = sw_elem->mode,
+			.block_tx = elems->ch_switch_ie->mode,
 			.channel = new_ch,
-			.count = sw_elem->count,
+			.count = elems->ch_switch_ie->count,
 		};
 
 		drv_channel_switch(sdata->local, &ch_switch);
@@ -1139,11 +1143,11 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
 	}
 
 	/* channel switch handled in software */
-	if (sw_elem->count <= 1)
+	if (elems->ch_switch_ie->count <= 1)
 		ieee80211_queue_work(&sdata->local->hw, &ifmgd->chswitch_work);
 	else
 		mod_timer(&ifmgd->chswitch_timer,
-			  TU_TO_EXP_TIME(sw_elem->count *
+			  TU_TO_EXP_TIME(elems->ch_switch_ie->count *
 					 cbss->beacon_interval));
 }
 
@@ -2709,7 +2713,8 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 	if (bss)
 		ieee80211_rx_bss_put(local, bss);
 
-	if (!sdata->u.mgd.associated)
+	if (!sdata->u.mgd.associated ||
+	    !ether_addr_equal(mgmt->bssid, sdata->u.mgd.associated->bssid))
 		return;
 
 	if (need_ps) {
@@ -2718,10 +2723,7 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 		mutex_unlock(&local->iflist_mtx);
 	}
 
-	if (elems->ch_switch_ie &&
-	    memcmp(mgmt->bssid, sdata->u.mgd.associated->bssid, ETH_ALEN) == 0)
-		ieee80211_sta_process_chanswitch(sdata, elems->ch_switch_ie,
-						 bss, rx_status->mactime);
+	ieee80211_sta_process_chanswitch(sdata, rx_status->mactime, elems);
 }
 
 
@@ -3115,14 +3117,27 @@ void ieee80211_sta_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 		rma = ieee80211_rx_mgmt_assoc_resp(sdata, mgmt, skb->len, &bss);
 		break;
 	case IEEE80211_STYPE_ACTION:
-		switch (mgmt->u.action.category) {
-		case WLAN_CATEGORY_SPECTRUM_MGMT:
+		if (mgmt->u.action.category == WLAN_CATEGORY_SPECTRUM_MGMT) {
+			struct ieee802_11_elems elems;
+			int ies_len = skb->len -
+				      offsetof(struct ieee80211_mgmt,
+					       u.action.u.chan_switch.variable);
+
+			if (ies_len < 0)
+				break;
+
+			ieee802_11_parse_elems(
+				mgmt->u.action.u.chan_switch.variable,
+				ies_len, &elems);
+
+			if (elems.parse_error)
+				break;
+
 			ieee80211_sta_process_chanswitch(sdata,
-					&mgmt->u.action.u.chan_switch.sw_elem,
-					(void *)ifmgd->associated->priv,
-					rx_status->mactime);
-			break;
+							 rx_status->mactime,
+							 &elems);
 		}
+		break;
 	}
 	mutex_unlock(&ifmgd->mtx);
 
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 9239bfa..ea91262 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2535,10 +2535,6 @@ ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
 			ieee80211_process_measurement_req(sdata, mgmt, len);
 			goto handled;
 		case WLAN_ACTION_SPCT_CHL_SWITCH:
-			if (len < (IEEE80211_MIN_ACTION_SIZE +
-				   sizeof(mgmt->u.action.u.chan_switch)))
-				break;
-
 			if (sdata->vif.type != NL80211_IFTYPE_STATION)
 				break;
 
-- 
1.8.0

[RFC 2/4] cfg80211: add ieee80211_operating_class_to_band

[Johannes Berg]

From: Johannes Berg <johannes.berg@intel.com>

This function converts a (global only!) operating
class to an internal band identifier. This will
be needed for extended channel switch support.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 include/net/cfg80211.h | 11 +++++++++++
 net/wireless/util.c    | 20 ++++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 172a693..ca7f6ed 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -4025,6 +4025,17 @@ bool cfg80211_reg_can_beacon(struct wiphy *wiphy,
 void cfg80211_ch_switch_notify(struct net_device *dev,
 			       struct cfg80211_chan_def *chandef);
 
+/**
+ * ieee80211_operating_class_to_band - convert operating class to band
+ *
+ * @operating_class: the operating class to convert
+ * @band: band pointer to fill
+ *
+ * Returns %true if the conversion was successful, %false otherwise.
+ */
+bool ieee80211_operating_class_to_band(u8 operating_class,
+				       enum ieee80211_band *band);
+
 /*
  * cfg80211_tdls_oper_request - request userspace to perform TDLS operation
  * @dev: the device on which the operation is requested
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 8b753b1..5871496 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -1160,6 +1160,26 @@ int cfg80211_get_p2p_attr(const u8 *ies, unsigned int len,
 }
 EXPORT_SYMBOL(cfg80211_get_p2p_attr);
 
+bool ieee80211_operating_class_to_band(u8 operating_class,
+				       enum ieee80211_band *band)
+{
+	switch (operating_class) {
+	case 112:
+	case 115 ... 127:
+		*band = IEEE80211_BAND_5GHZ;
+		return true;
+	case 81:
+	case 82:
+	case 83:
+	case 84:
+		*band = IEEE80211_BAND_2GHZ;
+		return true;
+	}
+
+	return false;
+}
+EXPORT_SYMBOL(ieee80211_operating_class_to_band);
+
 int cfg80211_validate_beacon_int(struct cfg80211_registered_device *rdev,
 				 u32 beacon_int)
 {
-- 
1.8.0

[RFC 3/4] mac80211: support extended channel switch

[Johannes Berg]

From: Johannes Berg <johannes.berg@intel.com>

Support extended channel switch when the operating
class is one of the global operating classes as
defined in Annex E of 802.11-2012. If it isn't,
disconnect from the AP instead.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 include/linux/ieee80211.h  | 12 ++++++++
 net/mac80211/ieee80211_i.h |  1 +
 net/mac80211/mlme.c        | 77 ++++++++++++++++++++++++++++++----------------
 net/mac80211/util.c        |  7 +++++
 4 files changed, 71 insertions(+), 26 deletions(-)

diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index ba8b10e..4305fc5 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -673,6 +673,18 @@ struct ieee80211_channel_sw_ie {
 } __packed;
 
 /**
+ * struct ieee80211_ext_chansw_ie
+ *
+ * This structure represents the "Extended Channel Switch Announcement element"
+ */
+struct ieee80211_ext_chansw_ie {
+	u8 mode;
+	u8 new_operating_class;
+	u8 new_ch_num;
+	u8 count;
+} __packed;
+
+/**
  * struct ieee80211_tim
  *
  * This structure refers to "Traffic Indication Map information element"
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index bd6ab0e..ca7df00 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1181,6 +1181,7 @@ struct ieee802_11_elems {
 	const u8 *perr;
 	const struct ieee80211_rann_ie *rann;
 	const struct ieee80211_channel_sw_ie *ch_switch_ie;
+	const struct ieee80211_ext_chansw_ie *ext_chansw_ie;
 	const u8 *country_elem;
 	const u8 *pwr_constr_elem;
 	const u8 *quiet_elem;	/* first quite element */
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index d266e52..538a417 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1058,56 +1058,79 @@ static void
 ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
 				 u64 timestamp, struct ieee802_11_elems *elems)
 {
+	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
 	struct cfg80211_bss *cbss = ifmgd->associated;
 	struct ieee80211_bss *bss;
 	struct ieee80211_channel *new_ch;
-	int new_freq;
 	struct ieee80211_chanctx *chanctx;
+	enum ieee80211_band new_band;
+	int new_freq;
+	u8 new_chan_no;
+	u8 count;
+	u8 mode;
 
 	ASSERT_MGD_MTX(ifmgd);
 
 	if (!cbss)
 		return;
 
-	if (sdata->local->scanning)
+	if (local->scanning)
 		return;
 
 	/* disregard subsequent announcements if we are already processing */
 	if (ifmgd->flags & IEEE80211_STA_CSA_RECEIVED)
 		return;
 
-	if (!elems->ch_switch_ie)
+	if (elems->ext_chansw_ie) {
+		if (!ieee80211_operating_class_to_band(
+				elems->ext_chansw_ie->new_operating_class,
+				&new_band)) {
+			sdata_info(sdata,
+				   "cannot understand ECSA IE operating class %d, disconnecting\n",
+				   elems->ext_chansw_ie->new_operating_class);
+			ieee80211_queue_work(&local->hw,
+					     &ifmgd->csa_connection_drop_work);
+		}
+		new_chan_no = elems->ext_chansw_ie->new_ch_num;
+		count = elems->ext_chansw_ie->count;
+		mode = elems->ext_chansw_ie->mode;
+	} else if (elems->ch_switch_ie) {
+		new_band = cbss->channel->band;
+		new_chan_no = elems->ch_switch_ie->new_ch_num;
+		count = elems->ch_switch_ie->count;
+		mode = elems->ch_switch_ie->mode;
+	} else {
+		/* nothing here we understand */
 		return;
+	}
 
 	bss = (void *)cbss->priv;
 
-	new_freq = ieee80211_channel_to_frequency(
-			elems->ch_switch_ie->new_ch_num,
-			cbss->channel->band);
-	new_ch = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
+	new_freq = ieee80211_channel_to_frequency(new_chan_no, new_band);
+	new_ch = ieee80211_get_channel(local->hw.wiphy, new_freq);
 	if (!new_ch || new_ch->flags & IEEE80211_CHAN_DISABLED) {
 		sdata_info(sdata,
 			   "AP %pM switches to unsupported channel (%d MHz), disconnecting\n",
 			   ifmgd->associated->bssid, new_freq);
-		ieee80211_queue_work(&sdata->local->hw,
+		ieee80211_queue_work(&local->hw,
 				     &ifmgd->csa_connection_drop_work);
 		return;
 	}
 
 	ifmgd->flags |= IEEE80211_STA_CSA_RECEIVED;
 
-	if (sdata->local->use_chanctx) {
+	if (local->use_chanctx) {
 		sdata_info(sdata,
 			   "not handling channel switch with channel contexts\n");
-		ieee80211_queue_work(&sdata->local->hw,
+		ieee80211_queue_work(&local->hw,
 				     &ifmgd->csa_connection_drop_work);
 		return;
 	}
 
-	mutex_lock(&sdata->local->chanctx_mtx);
+	mutex_lock(&local->chanctx_mtx);
 	if (WARN_ON(!rcu_access_pointer(sdata->vif.chanctx_conf))) {
-		mutex_unlock(&sdata->local->chanctx_mtx);
+		mutex_unlock(&local->chanctx_mtx);
 		return;
 	}
 	chanctx = container_of(rcu_access_pointer(sdata->vif.chanctx_conf),
@@ -1115,40 +1138,39 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
 	if (chanctx->refcount > 1) {
 		sdata_info(sdata,
 			   "channel switch with multiple interfaces on the same channel, disconnecting\n");
-		ieee80211_queue_work(&sdata->local->hw,
+		ieee80211_queue_work(&local->hw,
 				     &ifmgd->csa_connection_drop_work);
-		mutex_unlock(&sdata->local->chanctx_mtx);
+		mutex_unlock(&local->chanctx_mtx);
 		return;
 	}
-	mutex_unlock(&sdata->local->chanctx_mtx);
+	mutex_unlock(&local->chanctx_mtx);
 
-	sdata->local->csa_channel = new_ch;
+	local->csa_channel = new_ch;
 
-	if (elems->ch_switch_ie->mode)
-		ieee80211_stop_queues_by_reason(&sdata->local->hw,
+	if (mode)
+		ieee80211_stop_queues_by_reason(&local->hw,
 				IEEE80211_MAX_QUEUE_MAP,
 				IEEE80211_QUEUE_STOP_REASON_CSA);
 
-	if (sdata->local->ops->channel_switch) {
+	if (local->ops->channel_switch) {
 		/* use driver's channel switch callback */
 		struct ieee80211_channel_switch ch_switch = {
 			.timestamp = timestamp,
-			.block_tx = elems->ch_switch_ie->mode,
+			.block_tx = mode,
 			.channel = new_ch,
-			.count = elems->ch_switch_ie->count,
+			.count = count,
 		};
 
-		drv_channel_switch(sdata->local, &ch_switch);
+		drv_channel_switch(local, &ch_switch);
 		return;
 	}
 
 	/* channel switch handled in software */
-	if (elems->ch_switch_ie->count <= 1)
-		ieee80211_queue_work(&sdata->local->hw, &ifmgd->chswitch_work);
+	if (count <= 1)
+		ieee80211_queue_work(&local->hw, &ifmgd->chswitch_work);
 	else
 		mod_timer(&ifmgd->chswitch_timer,
-			  TU_TO_EXP_TIME(elems->ch_switch_ie->count *
-					 cbss->beacon_interval));
+			  TU_TO_EXP_TIME(count * cbss->beacon_interval));
 }
 
 static u32 ieee80211_handle_pwr_constr(struct ieee80211_sub_if_data *sdata,
@@ -2683,6 +2705,8 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 	struct ieee80211_channel *channel;
 	bool need_ps = false;
 
+	lockdep_assert_held(&sdata->u.mgd.mtx);
+
 	if ((sdata->u.mgd.associated &&
 	     ether_addr_equal(mgmt->bssid, sdata->u.mgd.associated->bssid)) ||
 	    (sdata->u.mgd.assoc_data &&
@@ -2724,6 +2748,7 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 	}
 
 	ieee80211_sta_process_chanswitch(sdata, rx_status->mactime, elems);
+
 }
 
 
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 1734cd2..543bb69 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -870,6 +870,13 @@ u32 ieee802_11_parse_elems_crc(u8 *start, size_t len,
 			}
 			elems->ch_switch_ie = (void *)pos;
 			break;
+		case WLAN_EID_EXT_CHANSWITCH_ANN:
+			if (elen != sizeof(struct ieee80211_ext_chansw_ie)) {
+				elem_parse_failed = true;
+				break;
+			}
+			elems->ext_chansw_ie = (void *)pos;
+			break;
 		case WLAN_EID_QUIET:
 			if (!elems->quiet_elem) {
 				elems->quiet_elem = pos;
-- 
1.8.0

[RFC 4/4] mac80211: support secondary channel offset in CSA

[Johannes Berg]

From: Johannes Berg <johannes.berg@intel.com>

Add support for the secondary channel offset IE in channel
switch announcements. This is necessary for proper handling
of CSA on HT access points.

For this to work it is also necessary to convert everything
here to use chandef structs instead of just channels. The
driver updates aren't really correct though. In particular,
the TI wl18xx driver update can't possibly be right since
it just ignores the new channel width for lack of firmware
API.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 drivers/net/wireless/iwlegacy/4965-mac.c    | 32 ++++++-------
 drivers/net/wireless/iwlegacy/4965.c        |  2 +-
 drivers/net/wireless/iwlwifi/dvm/devices.c  | 10 ++--
 drivers/net/wireless/iwlwifi/dvm/mac80211.c | 20 ++++++--
 drivers/net/wireless/iwlwifi/dvm/rxon.c     |  2 +-
 drivers/net/wireless/ti/wl12xx/cmd.c        |  2 +-
 drivers/net/wireless/ti/wl18xx/cmd.c        |  6 +--
 include/linux/ieee80211.h                   | 11 +++++
 include/net/mac80211.h                      |  4 +-
 net/mac80211/ieee80211_i.h                  |  3 +-
 net/mac80211/mlme.c                         | 71 +++++++++++++++++++++++------
 net/mac80211/trace.h                        |  8 ++--
 net/mac80211/util.c                         |  8 ++++
 13 files changed, 125 insertions(+), 54 deletions(-)

diff --git a/drivers/net/wireless/iwlegacy/4965-mac.c b/drivers/net/wireless/iwlegacy/4965-mac.c
index c092fcb..cb5882e 100644
--- a/drivers/net/wireless/iwlegacy/4965-mac.c
+++ b/drivers/net/wireless/iwlegacy/4965-mac.c
@@ -6057,7 +6057,7 @@ il4965_mac_channel_switch(struct ieee80211_hw *hw,
 	struct il_priv *il = hw->priv;
 	const struct il_channel_info *ch_info;
 	struct ieee80211_conf *conf = &hw->conf;
-	struct ieee80211_channel *channel = ch_switch->channel;
+	struct ieee80211_channel *channel = ch_switch->chandef.chan;
 	struct il_ht_config *ht_conf = &il->current_ht_config;
 	u16 ch;
 
@@ -6094,23 +6094,21 @@ il4965_mac_channel_switch(struct ieee80211_hw *hw,
 	il->current_ht_config.smps = conf->smps_mode;
 
 	/* Configure HT40 channels */
-	il->ht.enabled = conf_is_ht(conf);
-	if (il->ht.enabled) {
-		if (conf_is_ht40_minus(conf)) {
-			il->ht.extension_chan_offset =
-			    IEEE80211_HT_PARAM_CHA_SEC_BELOW;
-			il->ht.is_40mhz = true;
-		} else if (conf_is_ht40_plus(conf)) {
-			il->ht.extension_chan_offset =
-			    IEEE80211_HT_PARAM_CHA_SEC_ABOVE;
-			il->ht.is_40mhz = true;
-		} else {
-			il->ht.extension_chan_offset =
-			    IEEE80211_HT_PARAM_CHA_SEC_NONE;
-			il->ht.is_40mhz = false;
-		}
-	} else
+	switch (cfg80211_get_chandef_type(&ch_switch->chandef)) {
+	case NL80211_CHAN_NO_HT:
+	case NL80211_CHAN_HT20:
 		il->ht.is_40mhz = false;
+		il->ht.extension_chan_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE;
+		break;
+	case NL80211_CHAN_HT40MINUS:
+		il->ht.extension_chan_offset = IEEE80211_HT_PARAM_CHA_SEC_BELOW;
+		il->ht.is_40mhz = true;
+		break;
+	case NL80211_CHAN_HT40PLUS:
+		il->ht.extension_chan_offset = IEEE80211_HT_PARAM_CHA_SEC_ABOVE;
+		il->ht.is_40mhz = true;
+		break;
+	}
 
 	if ((le16_to_cpu(il->staging.channel) != ch))
 		il->staging.flags = 0;
diff --git a/drivers/net/wireless/iwlegacy/4965.c b/drivers/net/wireless/iwlegacy/4965.c
index 91eb2d0..777a578 100644
--- a/drivers/net/wireless/iwlegacy/4965.c
+++ b/drivers/net/wireless/iwlegacy/4965.c
@@ -1493,7 +1493,7 @@ il4965_hw_channel_switch(struct il_priv *il,
 
 	cmd.band = band;
 	cmd.expect_beacon = 0;
-	ch = ch_switch->channel->hw_value;
+	ch = ch_switch->chandef.chan->hw_value;
 	cmd.channel = cpu_to_le16(ch);
 	cmd.rxon_flags = il->staging.flags;
 	cmd.rxon_filter_flags = il->staging.filter_flags;
diff --git a/drivers/net/wireless/iwlwifi/dvm/devices.c b/drivers/net/wireless/iwlwifi/dvm/devices.c
index 15cca2e..c48907c 100644
--- a/drivers/net/wireless/iwlwifi/dvm/devices.c
+++ b/drivers/net/wireless/iwlwifi/dvm/devices.c
@@ -379,7 +379,7 @@ static int iwl5000_hw_channel_switch(struct iwl_priv *priv,
 	};
 
 	cmd.band = priv->band == IEEE80211_BAND_2GHZ;
-	ch = ch_switch->channel->hw_value;
+	ch = ch_switch->chandef.chan->hw_value;
 	IWL_DEBUG_11H(priv, "channel switch from %d to %d\n",
 		      ctx->active.channel, ch);
 	cmd.channel = cpu_to_le16(ch);
@@ -414,7 +414,8 @@ static int iwl5000_hw_channel_switch(struct iwl_priv *priv,
 	}
 	IWL_DEBUG_11H(priv, "uCode time for the switch is 0x%x\n",
 		      cmd.switch_time);
-	cmd.expect_beacon = ch_switch->channel->flags & IEEE80211_CHAN_RADAR;
+	cmd.expect_beacon =
+		ch_switch->chandef.chan->flags & IEEE80211_CHAN_RADAR;
 
 	return iwl_dvm_send_cmd(priv, &hcmd);
 }
@@ -540,7 +541,7 @@ static int iwl6000_hw_channel_switch(struct iwl_priv *priv,
 	hcmd.data[0] = cmd;
 
 	cmd->band = priv->band == IEEE80211_BAND_2GHZ;
-	ch = ch_switch->channel->hw_value;
+	ch = ch_switch->chandef.chan->hw_value;
 	IWL_DEBUG_11H(priv, "channel switch from %u to %u\n",
 		      ctx->active.channel, ch);
 	cmd->channel = cpu_to_le16(ch);
@@ -575,7 +576,8 @@ static int iwl6000_hw_channel_switch(struct iwl_priv *priv,
 	}
 	IWL_DEBUG_11H(priv, "uCode time for the switch is 0x%x\n",
 		      cmd->switch_time);
-	cmd->expect_beacon = ch_switch->channel->flags & IEEE80211_CHAN_RADAR;
+	cmd->expect_beacon =
+		ch_switch->chandef.chan->flags & IEEE80211_CHAN_RADAR;
 
 	err = iwl_dvm_send_cmd(priv, &hcmd);
 	kfree(cmd);
diff --git a/drivers/net/wireless/iwlwifi/dvm/mac80211.c b/drivers/net/wireless/iwlwifi/dvm/mac80211.c
index a7294fa..2dc101f 100644
--- a/drivers/net/wireless/iwlwifi/dvm/mac80211.c
+++ b/drivers/net/wireless/iwlwifi/dvm/mac80211.c
@@ -967,7 +967,7 @@ static void iwlagn_mac_channel_switch(struct ieee80211_hw *hw,
 {
 	struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);
 	struct ieee80211_conf *conf = &hw->conf;
-	struct ieee80211_channel *channel = ch_switch->channel;
+	struct ieee80211_channel *channel = ch_switch->chandef.chan;
 	struct iwl_ht_config *ht_conf = &priv->current_ht_config;
 	/*
 	 * MULTI-FIXME
@@ -1005,11 +1005,21 @@ static void iwlagn_mac_channel_switch(struct ieee80211_hw *hw,
 	priv->current_ht_config.smps = conf->smps_mode;
 
 	/* Configure HT40 channels */
-	ctx->ht.enabled = conf_is_ht(conf);
-	if (ctx->ht.enabled)
-		iwlagn_config_ht40(conf, ctx);
-	else
+	switch (cfg80211_get_chandef_type(&ch_switch->chandef)) {
+	case NL80211_CHAN_NO_HT:
+	case NL80211_CHAN_HT20:
 		ctx->ht.is_40mhz = false;
+		ctx->ht.extension_chan_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE;
+		break;
+	case NL80211_CHAN_HT40MINUS:
+		ctx->ht.extension_chan_offset = IEEE80211_HT_PARAM_CHA_SEC_BELOW;
+		ctx->ht.is_40mhz = true;
+		break;
+	case NL80211_CHAN_HT40PLUS:
+		ctx->ht.extension_chan_offset = IEEE80211_HT_PARAM_CHA_SEC_ABOVE;
+		ctx->ht.is_40mhz = true;
+		break;
+	}
 
 	if ((le16_to_cpu(ctx->staging.channel) != ch))
 		ctx->staging.flags = 0;
diff --git a/drivers/net/wireless/iwlwifi/dvm/rxon.c b/drivers/net/wireless/iwlwifi/dvm/rxon.c
index 085c589..acbb50b 100644
--- a/drivers/net/wireless/iwlwifi/dvm/rxon.c
+++ b/drivers/net/wireless/iwlwifi/dvm/rxon.c
@@ -1160,7 +1160,7 @@ int iwlagn_commit_rxon(struct iwl_priv *priv, struct iwl_rxon_context *ctx)
 }
 
 void iwlagn_config_ht40(struct ieee80211_conf *conf,
-	struct iwl_rxon_context *ctx)
+			struct iwl_rxon_context *ctx)
 {
 	if (conf_is_ht40_minus(conf)) {
 		ctx->ht.extension_chan_offset =
diff --git a/drivers/net/wireless/ti/wl12xx/cmd.c b/drivers/net/wireless/ti/wl12xx/cmd.c
index 7dc9f96..7485dba 100644
--- a/drivers/net/wireless/ti/wl12xx/cmd.c
+++ b/drivers/net/wireless/ti/wl12xx/cmd.c
@@ -301,7 +301,7 @@ int wl12xx_cmd_channel_switch(struct wl1271 *wl,
 	}
 
 	cmd->role_id = wlvif->role_id;
-	cmd->channel = ch_switch->channel->hw_value;
+	cmd->channel = ch_switch->chandef.chan->hw_value;
 	cmd->switch_time = ch_switch->count;
 	cmd->stop_tx = ch_switch->block_tx;
 
diff --git a/drivers/net/wireless/ti/wl18xx/cmd.c b/drivers/net/wireless/ti/wl18xx/cmd.c
index 1d1f6cc..7649c75 100644
--- a/drivers/net/wireless/ti/wl18xx/cmd.c
+++ b/drivers/net/wireless/ti/wl18xx/cmd.c
@@ -42,11 +42,11 @@ int wl18xx_cmd_channel_switch(struct wl1271 *wl,
 	}
 
 	cmd->role_id = wlvif->role_id;
-	cmd->channel = ch_switch->channel->hw_value;
+	cmd->channel = ch_switch->chandef.chan->hw_value;
 	cmd->switch_time = ch_switch->count;
 	cmd->stop_tx = ch_switch->block_tx;
 
-	switch (ch_switch->channel->band) {
+	switch (ch_switch->chandef.chan->band) {
 	case IEEE80211_BAND_2GHZ:
 		cmd->band = WLCORE_BAND_2_4GHZ;
 		break;
@@ -55,7 +55,7 @@ int wl18xx_cmd_channel_switch(struct wl1271 *wl,
 		break;
 	default:
 		wl1271_error("invalid channel switch band: %d",
-			     ch_switch->channel->band);
+			     ch_switch->chandef.chan->band);
 		ret = -EINVAL;
 		goto out_free;
 	}
diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index 4305fc5..902e5c0 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -685,6 +685,16 @@ struct ieee80211_ext_chansw_ie {
 } __packed;
 
 /**
+ * struct ieee80211_sec_chan_offs_ie - secondary channel offset IE
+ * @sec_chan_offs: secondary channel offset, uses IEEE80211_HT_PARAM_CHA_SEC_*
+ *	values here
+ * This structure represents the "Secondary Channel Offset element"
+ */
+struct ieee80211_sec_chan_offs_ie {
+	u8 sec_chan_offs;
+} __packed;
+
+/**
  * struct ieee80211_tim
  *
  * This structure refers to "Traffic Indication Map information element"
@@ -1648,6 +1658,7 @@ enum ieee80211_eid {
 
 	WLAN_EID_HT_CAPABILITY = 45,
 	WLAN_EID_HT_OPERATION = 61,
+	WLAN_EID_SECONDARY_CHANNEL_OFFSET = 62,
 
 	WLAN_EID_RSN = 48,
 	WLAN_EID_MMIE = 76,
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 64faf01..70b0e56 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1017,13 +1017,13 @@ struct ieee80211_conf {
  *	the driver passed into mac80211.
  * @block_tx: Indicates whether transmission must be blocked before the
  *	scheduled channel switch, as indicated by the AP.
- * @channel: the new channel to switch to
+ * @chandef: the new channel to switch to
  * @count: the number of TBTT's until the channel switch event
  */
 struct ieee80211_channel_switch {
 	u64 timestamp;
 	bool block_tx;
-	struct ieee80211_channel *channel;
+	struct cfg80211_chan_def chandef;
 	u8 count;
 };
 
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index ca7df00..0ea8b97 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1019,7 +1019,7 @@ struct ieee80211_local {
 	enum mac80211_scan_state next_scan_state;
 	struct delayed_work scan_work;
 	struct ieee80211_sub_if_data __rcu *scan_sdata;
-	struct ieee80211_channel *csa_channel;
+	struct cfg80211_chan_def csa_chandef;
 	/* For backward compatibility only -- do not use */
 	struct cfg80211_chan_def _oper_chandef;
 
@@ -1187,6 +1187,7 @@ struct ieee802_11_elems {
 	const u8 *quiet_elem;	/* first quite element */
 	const u8 *timeout_int;
 	const u8 *opmode_notif;
+	const struct ieee80211_sec_chan_offs_ie *sec_chan_offs;
 
 	/* length of them, respectively */
 	u8 ssid_len;
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 538a417..7b99d50 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -289,6 +289,8 @@ ieee80211_determine_chantype(struct ieee80211_sub_if_data *sdata,
 	} else {
 		/* 40 MHz (and 80 MHz) must be supported for VHT */
 		ret = IEEE80211_STA_DISABLE_VHT;
+		/* also mark 40 MHz disabled */
+		ret |= IEEE80211_STA_DISABLE_40MHZ;
 		goto out;
 	}
 
@@ -998,16 +1000,7 @@ static void ieee80211_chswitch_work(struct work_struct *work)
 	if (!ifmgd->associated)
 		goto out;
 
-	/*
-	 * FIXME: Here we are downgrading to NL80211_CHAN_WIDTH_20_NOHT
-	 * and don't adjust our ht/vht settings
-	 * This is wrong - we should behave according to the CSA params
-	 */
-	local->_oper_chandef.chan = local->csa_channel;
-	local->_oper_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
-	local->_oper_chandef.center_freq1 =
-		local->_oper_chandef.chan->center_freq;
-	local->_oper_chandef.center_freq2 = 0;
+	local->_oper_chandef = local->csa_chandef;
 
 	if (!local->ops->channel_switch) {
 		/* call "hw_config" only if doing sw channel switch */
@@ -1062,13 +1055,14 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
 	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
 	struct cfg80211_bss *cbss = ifmgd->associated;
 	struct ieee80211_bss *bss;
-	struct ieee80211_channel *new_ch;
 	struct ieee80211_chanctx *chanctx;
 	enum ieee80211_band new_band;
 	int new_freq;
 	u8 new_chan_no;
 	u8 count;
 	u8 mode;
+	struct cfg80211_chan_def new_chandef = {};
+	int secondary_channel_offset = -1;
 
 	ASSERT_MGD_MTX(ifmgd);
 
@@ -1082,6 +1076,19 @@ 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;
+	}
+
+	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 (elems->ext_chansw_ie) {
 		if (!ieee80211_operating_class_to_band(
 				elems->ext_chansw_ie->new_operating_class,
@@ -1108,8 +1115,9 @@ 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_ch = ieee80211_get_channel(local->hw.wiphy, new_freq);
-	if (!new_ch || new_ch->flags & IEEE80211_CHAN_DISABLED) {
+	new_chandef.chan = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
+	if (!new_chandef.chan ||
+	    new_chandef.chan->flags & IEEE80211_CHAN_DISABLED) {
 		sdata_info(sdata,
 			   "AP %pM switches to unsupported channel (%d MHz), disconnecting\n",
 			   ifmgd->associated->bssid, new_freq);
@@ -1118,6 +1126,39 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
 		return;
 	}
 
+	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,
+					NL80211_CHAN_HT20);
+		break;
+	case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
+		cfg80211_chandef_create(&new_chandef, new_chandef.chan,
+					NL80211_CHAN_HT40PLUS);
+		break;
+	case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
+		cfg80211_chandef_create(&new_chandef, new_chandef.chan,
+					NL80211_CHAN_HT40MINUS);
+		break;
+	case -1:
+		cfg80211_chandef_create(&new_chandef, new_chandef.chan,
+					NL80211_CHAN_NO_HT);
+		break;
+	}
+
+	if (!cfg80211_chandef_usable(local->hw.wiphy, &new_chandef,
+				     IEEE80211_CHAN_DISABLED)) {
+		sdata_info(sdata,
+			   "AP %pM switches to unsupported channel (%d MHz, width:%d, CF1/2: %d/%d MHz), disconnecting\n",
+			   ifmgd->associated->bssid, new_freq,
+			   new_chandef.width, new_chandef.center_freq1,
+			   new_chandef.center_freq2);
+		ieee80211_queue_work(&local->hw,
+				     &ifmgd->csa_connection_drop_work);
+		return;
+	}
+
 	ifmgd->flags |= IEEE80211_STA_CSA_RECEIVED;
 
 	if (local->use_chanctx) {
@@ -1145,7 +1186,7 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
 	}
 	mutex_unlock(&local->chanctx_mtx);
 
-	local->csa_channel = new_ch;
+	local->csa_chandef = new_chandef;
 
 	if (mode)
 		ieee80211_stop_queues_by_reason(&local->hw,
@@ -1157,7 +1198,7 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
 		struct ieee80211_channel_switch ch_switch = {
 			.timestamp = timestamp,
 			.block_tx = mode,
-			.channel = new_ch,
+			.chandef = new_chandef,
 			.count = count,
 		};
 
diff --git a/net/mac80211/trace.h b/net/mac80211/trace.h
index 8286dce..c215fafd7 100644
--- a/net/mac80211/trace.h
+++ b/net/mac80211/trace.h
@@ -990,23 +990,23 @@ TRACE_EVENT(drv_channel_switch,
 
 	TP_STRUCT__entry(
 		LOCAL_ENTRY
+		CHANDEF_ENTRY
 		__field(u64, timestamp)
 		__field(bool, block_tx)
-		__field(u16, freq)
 		__field(u8, count)
 	),
 
 	TP_fast_assign(
 		LOCAL_ASSIGN;
+		CHANDEF_ASSIGN(&ch_switch->chandef)
 		__entry->timestamp = ch_switch->timestamp;
 		__entry->block_tx = ch_switch->block_tx;
-		__entry->freq = ch_switch->channel->center_freq;
 		__entry->count = ch_switch->count;
 	),
 
 	TP_printk(
-		LOCAL_PR_FMT " new freq:%u count:%d",
-		LOCAL_PR_ARG, __entry->freq, __entry->count
+		LOCAL_PR_FMT " new " CHANDEF_PR_FMT " count:%d",
+		LOCAL_PR_ARG, CHANDEF_PR_ARG, __entry->count
 	)
 );
 
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 543bb69..c9bd742 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -715,6 +715,7 @@ u32 ieee802_11_parse_elems_crc(u8 *start, size_t len,
 		case WLAN_EID_COUNTRY:
 		case WLAN_EID_PWR_CONSTRAINT:
 		case WLAN_EID_TIMEOUT_INTERVAL:
+		case WLAN_EID_SECONDARY_CHANNEL_OFFSET:
 			if (test_bit(id, seen_elems)) {
 				elems->parse_error = true;
 				left -= elen;
@@ -877,6 +878,13 @@ u32 ieee802_11_parse_elems_crc(u8 *start, size_t len,
 			}
 			elems->ext_chansw_ie = (void *)pos;
 			break;
+		case WLAN_EID_SECONDARY_CHANNEL_OFFSET:
+			if (elen != sizeof(struct ieee80211_sec_chan_offs_ie)) {
+				elem_parse_failed = true;
+				break;
+			}
+			elems->sec_chan_offs = (void *)pos;
+			break;
 		case WLAN_EID_QUIET:
 			if (!elems->quiet_elem) {
 				elems->quiet_elem = pos;
-- 
1.8.0

[RFC] mac80211: handle extended channel switch announcement

[Johannes Berg]

From: Johannes Berg <johannes.berg@intel.com>

Handle the (public) extended channel switch announcement
action frames. Parts of the data in these frames isn't
really in IEs, but put it into the elems struct anyway
to simplify the handling.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 include/linux/ieee80211.h |  6 ++++++
 net/mac80211/mlme.c       | 31 +++++++++++++++++++++++++++----
 net/mac80211/rx.c         | 16 ++++++++++++++++
 3 files changed, 49 insertions(+), 4 deletions(-)

diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index a985e67..db1b3a6 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -874,6 +874,11 @@ struct ieee80211_mgmt {
 				} __packed chan_switch;
 				struct{
 					u8 action_code;
+					struct ieee80211_ext_chansw_ie data;
+					u8 variable[0];
+				} __packed ext_chan_switch;
+				struct{
+					u8 action_code;
 					u8 dialog_token;
 					u8 element_id;
 					u8 length;
@@ -1825,6 +1830,7 @@ enum ieee80211_key_len {
 
 /* Public action codes */
 enum ieee80211_pub_actioncode {
+	WLAN_PUB_ACTION_EXT_CHANSW_ANN = 4,
 	WLAN_PUB_ACTION_TDLS_DISCOVER_RES = 14,
 };
 
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 7b99d50..cb0c738 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -3154,6 +3154,8 @@ void ieee80211_sta_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 	enum rx_mgmt_action rma = RX_MGMT_NONE;
 	u8 deauth_buf[IEEE80211_DEAUTH_FRAME_LEN];
 	u16 fc;
+	struct ieee802_11_elems elems;
+	int ies_len;
 
 	rx_status = (struct ieee80211_rx_status *) skb->cb;
 	mgmt = (struct ieee80211_mgmt *) skb->data;
@@ -3184,10 +3186,9 @@ void ieee80211_sta_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 		break;
 	case IEEE80211_STYPE_ACTION:
 		if (mgmt->u.action.category == WLAN_CATEGORY_SPECTRUM_MGMT) {
-			struct ieee802_11_elems elems;
-			int ies_len = skb->len -
-				      offsetof(struct ieee80211_mgmt,
-					       u.action.u.chan_switch.variable);
+			ies_len = skb->len -
+				  offsetof(struct ieee80211_mgmt,
+					   u.action.u.chan_switch.variable);
 
 			if (ies_len < 0)
 				break;
@@ -3202,6 +3203,28 @@ void ieee80211_sta_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 			ieee80211_sta_process_chanswitch(sdata,
 							 rx_status->mactime,
 							 &elems);
+		} else if (mgmt->u.action.category == WLAN_CATEGORY_PUBLIC) {
+			ies_len = skb->len -
+				  offsetof(struct ieee80211_mgmt,
+					   u.action.u.ext_chan_switch.variable);
+
+			if (ies_len < 0)
+				break;
+
+			ieee802_11_parse_elems(
+				mgmt->u.action.u.ext_chan_switch.variable,
+				ies_len, &elems);
+
+			if (elems.parse_error)
+				break;
+
+			/* for the handling code pretend this was also an IE */
+			elems.ext_chansw_ie =
+				&mgmt->u.action.u.ext_chan_switch.data;
+
+			ieee80211_sta_process_chanswitch(sdata,
+							 rx_status->mactime,
+							 &elems);
 		}
 		break;
 	}
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index ea91262..562ae34 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2452,6 +2452,22 @@ ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
 		}
 
 		break;
+	case WLAN_CATEGORY_PUBLIC:
+		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
+			goto invalid;
+		if (sdata->vif.type != NL80211_IFTYPE_STATION)
+			break;
+		if (!rx->sta)
+			break;
+		if (!ether_addr_equal(mgmt->bssid, sdata->u.mgd.bssid))
+			break;
+		if (mgmt->u.action.u.ext_chan_switch.action_code !=
+				WLAN_PUB_ACTION_EXT_CHANSW_ANN)
+			break;
+		if (len < offsetof(struct ieee80211_mgmt,
+				   u.action.u.ext_chan_switch.variable))
+			goto invalid;
+		goto queue;
 	case WLAN_CATEGORY_VHT:
 		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
 		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
-- 
1.8.0