2 files changed, 18 insertions, 2 deletions

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 0d5979924be3..4d5acb013636 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1468,6 +1468,9 @@ struct ieee80211_txrx_stypes {
  * @mgmt_stypes: bitmasks of frame subtypes that can be subscribed to or
  *      transmitted through nl80211, points to an array indexed by interface
  *      type
+ *
+ * @available_antennas: bitmap of antennas which are available to configure.
+ *      antenna configuration commands will be rejected unless this is set.
  */
 struct wiphy {
         /* assign these fields before you register the wiphy */
@@ -1507,6 +1510,8 @@ struct wiphy {
 
         u8 max_num_pmkids;
 
+        u32 available_antennas;
+
         /* If multiple wiphys are registered and you're handed e.g.
          * a regular netdev with assigned ieee80211_ptr, you won't
          * know whether it points to a wiphy your driver has registered
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index c3f80e565365..73a7f6d354c9 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -548,7 +548,7 @@ static int nl80211_send_wiphy(struct sk_buff *msg, u32 pid, u32 seq, int flags,
         if (dev->wiphy.flags & WIPHY_FLAG_CONTROL_PORT_PROTOCOL)
                 NLA_PUT_FLAG(msg, NL80211_ATTR_CONTROL_PORT_ETHERTYPE);
 
-        if (dev->ops->get_antenna) {
+        if (dev->wiphy.available_antennas && dev->ops->get_antenna) {
                 u32 tx_ant = 0, rx_ant = 0;
                 int res;
                 res = dev->ops->get_antenna(&dev->wiphy, &tx_ant, &rx_ant);
@@ -1046,7 +1046,7 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
         if (info->attrs[NL80211_ATTR_WIPHY_ANTENNA_TX] &&
             info->attrs[NL80211_ATTR_WIPHY_ANTENNA_RX]) {
                 u32 tx_ant, rx_ant;
-                if (!rdev->ops->set_antenna) {
+                if (!rdev->wiphy.available_antennas || !rdev->ops->set_antenna) {
                         result = -EOPNOTSUPP;
                         goto bad_res;
                 }
@@ -1054,6 +1054,17 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
                 tx_ant = nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_ANTENNA_TX]);
                 rx_ant = nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_ANTENNA_RX]);
 
+                /* reject antenna configurations which don't match the
+                 * available antenna mask, except for the "all" mask */
+                if ((~tx_ant && (tx_ant & ~rdev->wiphy.available_antennas)) ||
+                    (~rx_ant && (rx_ant & ~rdev->wiphy.available_antennas))) {
+                        result = -EINVAL;
+                        goto bad_res;
+                }
+
+                tx_ant = tx_ant & rdev->wiphy.available_antennas;
+                rx_ant = rx_ant & rdev->wiphy.available_antennas;
+
                 result = rdev->ops->set_antenna(&rdev->wiphy, tx_ant, rx_ant);
                 if (result)
                         goto bad_res;