mac80211/cfg80211: report monitor channel in wireless extensions

Just add API to get the channel & report it. Trivial really.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

include/net/cfg80211.h

@@ -1342,6 +1342,9 @@ struct cfg80211_gtk_rekey_data {
  *	doesn't verify much. Note, however, that the passed netdev may be
  *	%NULL as well if the user requested changing the channel for the
  *	device itself, or for a monitor interface.
+ * @get_channel: Get the current operating channel, should return %NULL if
+ *	there's no single defined operating channel if for example the
+ *	device implements channel hopping for multi-channel virtual interfaces.
  *
  * @scan: Request to do a scan. If returning zero, the scan request is given
  *	the driver, and will be valid until passed to cfg80211_scan_done().
@@ -1627,6 +1630,8 @@ struct cfg80211_ops {
 
 	int	(*probe_client)(struct wiphy *wiphy, struct net_device *dev,
 				const u8 *peer, u64 *cookie);
+
+	struct ieee80211_channel *(*get_channel)(struct wiphy *wiphy);
 };
 
 /*

net/mac80211/cfg.c

@@ -2590,6 +2590,14 @@ static int ieee80211_probe_client(struct wiphy *wiphy, struct net_device *dev,
 	return 0;
 }
 
+static struct ieee80211_channel *
+ieee80211_wiphy_get_channel(struct wiphy *wiphy)
+{
+	struct ieee80211_local *local = wiphy_priv(wiphy);
+
+	return local->oper_channel;
+}
+
 struct cfg80211_ops mac80211_config_ops = {
 	.add_virtual_intf = ieee80211_add_iface,
 	.del_virtual_intf = ieee80211_del_iface,
@@ -2656,4 +2664,5 @@ struct cfg80211_ops mac80211_config_ops = {
 	.tdls_oper = ieee80211_tdls_oper,
 	.tdls_mgmt = ieee80211_tdls_mgmt,
 	.probe_client = ieee80211_probe_client,
+	.get_channel = ieee80211_wiphy_get_channel,
 };

net/wireless/wext-compat.c

@@ -818,12 +818,24 @@ static int cfg80211_wext_giwfreq(struct net_device *dev,
 				 struct iw_freq *freq, char *extra)
 {
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
+	struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
+	struct ieee80211_channel *chan;
 
 	switch (wdev->iftype) {
 	case NL80211_IFTYPE_STATION:
 		return cfg80211_mgd_wext_giwfreq(dev, info, freq, extra);
 	case NL80211_IFTYPE_ADHOC:
 		return cfg80211_ibss_wext_giwfreq(dev, info, freq, extra);
+	case NL80211_IFTYPE_MONITOR:
+		if (!rdev->ops->get_channel)
+			return -EINVAL;
+
+		chan = rdev->ops->get_channel(wdev->wiphy);
+		if (!chan)
+			return -EINVAL;
+		freq->m = chan->center_freq;
+		freq->e = 6;
+		return 0;
 	default:
 		if (!wdev->channel)
 			return -EINVAL;