cfg80211: add channel tracking for AP and mesh

We need to know which channel is used by a running
AP and mesh for channel context accounting and
finding matching/active interface combination.

STA/IBSS have current_bss already which allows us
to check which channel a vif is tuned to.
Non-fixed channel IBSS can be handled with
additional changes.

Monitor mode is going to be handled differently.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/cfg80211.h

@@ -2408,6 +2408,9 @@ struct wireless_dev {
 	struct ieee80211_channel *preset_chan;
 	enum nl80211_channel_type preset_chantype;
 
+	/* for AP and mesh channel tracking */
+	struct ieee80211_channel *channel;
+
 	bool ps;
 	int ps_timeout;
 

net/wireless/ap.c

@@ -24,8 +24,10 @@ static int __cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
 		return -ENOENT;
 
 	err = rdev->ops->stop_ap(&rdev->wiphy, dev);
-	if (!err)
+	if (!err) {
 		wdev->beacon_interval = 0;
+		wdev->channel = NULL;
+	}
 
 	return err;
 }

net/wireless/mesh.c

@@ -159,6 +159,7 @@ int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
 	if (!err) {
 		memcpy(wdev->ssid, setup->mesh_id, setup->mesh_id_len);
 		wdev->mesh_id_len = setup->mesh_id_len;
+		wdev->channel = setup->channel;
 	}
 
 	return err;
@@ -184,6 +185,7 @@ int cfg80211_set_mesh_freq(struct cfg80211_registered_device *rdev,
 			   enum nl80211_channel_type channel_type)
 {
 	struct ieee80211_channel *channel;
+	int err;
 
 	channel = rdev_freq_to_chan(rdev, freq, channel_type);
 	if (!channel || !cfg80211_can_beacon_sec_chan(&rdev->wiphy,
@@ -205,9 +207,14 @@ int cfg80211_set_mesh_freq(struct cfg80211_registered_device *rdev,
 
 		if (!netif_running(wdev->netdev))
 			return -ENETDOWN;
-		return rdev->ops->libertas_set_mesh_channel(&rdev->wiphy,
+
+		err = rdev->ops->libertas_set_mesh_channel(&rdev->wiphy,
 							   wdev->netdev,
 							   channel);
+		if (!err)
+			wdev->channel = channel;
+
+		return err;
 	}
 
 	if (wdev->mesh_id_len)
@@ -249,8 +256,11 @@ static int __cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
 		return -ENOTCONN;
 
 	err = rdev->ops->leave_mesh(&rdev->wiphy, dev);
-	if (!err)
+	if (!err) {
 		wdev->mesh_id_len = 0;
+		wdev->channel = NULL;
+	}
+
 	return err;
 }
 

net/wireless/mlme.c

@@ -947,6 +947,7 @@ void cfg80211_ch_switch_notify(struct net_device *dev, int freq,
 	if (WARN_ON(!chan))
 		goto out;
 
+	wdev->channel = chan;
 	nl80211_ch_switch_notify(rdev, dev, freq, type, GFP_KERNEL);
 out:
 	wdev_unlock(wdev);

net/wireless/nl80211.c

@@ -2488,6 +2488,7 @@ static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
 		wdev->preset_chan = params.channel;
 		wdev->preset_chantype = params.channel_type;
 		wdev->beacon_interval = params.beacon_interval;
+		wdev->channel = params.channel;
 	}
 	return err;
 }