mac80211: add support for CSA in IBSS mode

This function adds the channel switch announcement implementation for the
IBSS code. It is triggered by userspace (mac80211/cfg) or by external
channel switch announcement, which have to be adopted. Both CSAs in
beacons and action frames are supported. As for AP mode, the channel
switch is applied after some time. However in IBSS mode, the channel
switch IEs are generated in the kernel.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/cfg.c

@@ -2865,30 +2865,38 @@ void ieee80211_csa_finalize_work(struct work_struct *work)
 	if (!ieee80211_sdata_running(sdata))
 		return;
 
-	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
-		return;
-
 	sdata->radar_required = sdata->csa_radar_required;
 	err = ieee80211_vif_change_channel(sdata, &local->csa_chandef,
 					   &changed);
 	if (WARN_ON(err < 0))
 		return;
 
-	err = ieee80211_assign_beacon(sdata, sdata->u.ap.next_beacon);
-	if (err < 0)
-		return;
+	ieee80211_bss_info_change_notify(sdata, changed);
 
-	changed |= err;
-	kfree(sdata->u.ap.next_beacon);
-	sdata->u.ap.next_beacon = NULL;
+	switch (sdata->vif.type) {
+	case NL80211_IFTYPE_AP:
+		err = ieee80211_assign_beacon(sdata, sdata->u.ap.next_beacon);
+		if (err < 0)
+			return;
+		changed |= err;
+		kfree(sdata->u.ap.next_beacon);
+		sdata->u.ap.next_beacon = NULL;
+
+		ieee80211_bss_info_change_notify(sdata, err);
+		break;
+	case NL80211_IFTYPE_ADHOC:
+		ieee80211_ibss_finish_csa(sdata);
+		break;
+	default:
+		WARN_ON(1);
+		return;
+	}
 	sdata->vif.csa_active = false;
 
 	ieee80211_wake_queues_by_reason(&sdata->local->hw,
 					IEEE80211_MAX_QUEUE_MAP,
 					IEEE80211_QUEUE_STOP_REASON_CSA);
 
-	ieee80211_bss_info_change_notify(sdata, changed);
-
 	cfg80211_ch_switch_notify(sdata->dev, &local->csa_chandef);
 }
 
@@ -2936,31 +2944,63 @@ static int ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev,
 	if (sdata->vif.csa_active)
 		return -EBUSY;
 
-	/* only handle AP for now. */
 	switch (sdata->vif.type) {
 	case NL80211_IFTYPE_AP:
+		sdata->csa_counter_offset_beacon =
+			params->counter_offset_beacon;
+		sdata->csa_counter_offset_presp = params->counter_offset_presp;
+		sdata->u.ap.next_beacon =
+			cfg80211_beacon_dup(&params->beacon_after);
+		if (!sdata->u.ap.next_beacon)
+			return -ENOMEM;
+
+		err = ieee80211_assign_beacon(sdata, &params->beacon_csa);
+		if (err < 0) {
+			kfree(sdata->u.ap.next_beacon);
+			return err;
+		}
+		break;
+	case NL80211_IFTYPE_ADHOC:
+		if (!sdata->vif.bss_conf.ibss_joined)
+			return -EINVAL;
+
+		if (params->chandef.width != sdata->u.ibss.chandef.width)
+			return -EINVAL;
+
+		switch (params->chandef.width) {
+		case NL80211_CHAN_WIDTH_40:
+			if (cfg80211_get_chandef_type(&params->chandef) !=
+			    cfg80211_get_chandef_type(&sdata->u.ibss.chandef))
+				return -EINVAL;
+		case NL80211_CHAN_WIDTH_5:
+		case NL80211_CHAN_WIDTH_10:
+		case NL80211_CHAN_WIDTH_20_NOHT:
+		case NL80211_CHAN_WIDTH_20:
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		/* changes into another band are not supported */
+		if (sdata->u.ibss.chandef.chan->band !=
+		    params->chandef.chan->band)
+			return -EINVAL;
+
+		err = ieee80211_ibss_csa_beacon(sdata, params);
+		if (err < 0)
+			return err;
 		break;
 	default:
 		return -EOPNOTSUPP;
 	}
 
-	sdata->u.ap.next_beacon = cfg80211_beacon_dup(&params->beacon_after);
-	if (!sdata->u.ap.next_beacon)
-		return -ENOMEM;
-
-	sdata->csa_counter_offset_beacon = params->counter_offset_beacon;
-	sdata->csa_counter_offset_presp = params->counter_offset_presp;
 	sdata->csa_radar_required = params->radar_required;
 
 	if (params->block_tx)
 		ieee80211_stop_queues_by_reason(&local->hw,
 				IEEE80211_MAX_QUEUE_MAP,
 				IEEE80211_QUEUE_STOP_REASON_CSA);
 
-	err = ieee80211_assign_beacon(sdata, &params->beacon_csa);
-	if (err < 0)
-		return err;
-
 	local->csa_chandef = params->chandef;
 	sdata->vif.csa_active = true;
 
@@ -3014,7 +3054,8 @@ static int ieee80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
 			need_offchan = true;
 		if (!ieee80211_is_action(mgmt->frame_control) ||
 		    mgmt->u.action.category == WLAN_CATEGORY_PUBLIC ||
-		    mgmt->u.action.category == WLAN_CATEGORY_SELF_PROTECTED)
+		    mgmt->u.action.category == WLAN_CATEGORY_SELF_PROTECTED ||
+		    mgmt->u.action.category == WLAN_CATEGORY_SPECTRUM_MGMT)
 			break;
 		rcu_read_lock();
 		sta = sta_info_get(sdata, mgmt->da);