[MAC80211]: Add SIOCGIWTXPOWER routine

The wireless extensions ioctl's implemented in mac80211 do not include
SIOCGIWTXPOWER. This patch adds the necessary code.
Acked-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/ieee80211_ioctl.c

@@ -798,6 +798,20 @@ static int ieee80211_ioctl_giwrate(struct net_device *dev,
 	return 0;
 }
 
+static int ieee80211_ioctl_giwtxpower(struct net_device *dev,
+				   struct iw_request_info *info,
+				   union iwreq_data *data, char *extra)
+{
+	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
+
+	data->txpower.fixed = 1;
+	data->txpower.disabled = !(local->hw.conf.radio_enabled);
+	data->txpower.value = local->hw.conf.power_level;
+	data->txpower.flags = IW_TXPOW_DBM;
+
+	return 0;
+}
+
 static int ieee80211_ioctl_siwrts(struct net_device *dev,
 				  struct iw_request_info *info,
 				  struct iw_param *rts, char *extra)
@@ -1587,7 +1601,7 @@ static const iw_handler ieee80211_handler[] =
 	(iw_handler) ieee80211_ioctl_siwfrag,		/* SIOCSIWFRAG */
 	(iw_handler) ieee80211_ioctl_giwfrag,		/* SIOCGIWFRAG */
 	(iw_handler) NULL,				/* SIOCSIWTXPOW */
-	(iw_handler) NULL,				/* SIOCGIWTXPOW */
+	(iw_handler) ieee80211_ioctl_giwtxpower,	/* SIOCGIWTXPOW */
 	(iw_handler) ieee80211_ioctl_siwretry,		/* SIOCSIWRETRY */
 	(iw_handler) ieee80211_ioctl_giwretry,		/* SIOCGIWRETRY */
 	(iw_handler) ieee80211_ioctl_siwencode,		/* SIOCSIWENCODE */