cfg80211: track monitor interfaces count

Implements .set_monitor_enabled(wiphy, enabled).

Notifies driver upon change of interface layout.

If only monitor interfaces become present it is
called with 2nd argument being true. If
non-monitor interface appears then 2nd argument
is false. Driver is notified only upon change.

This makes it more obvious about the fact that
cfg80211 supports single monitor channel. Once we
implement multi-channel we don't want to allow
setting monitor channel while other interface
types are running. Otherwise it would be ambiguous
once we start considering num_different_channels.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index e030c6af86dd..f0d213dd8fe7 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1499,6 +1499,8 @@ struct cfg80211_gtk_rekey_data {
  *      interfaces are active this callback should reject the configuration.
  *      If no interfaces are active or the device is down, the channel should
  *      be stored for when a monitor interface becomes active.
+ * @set_monitor_enabled: Notify driver that there are only monitor
+ *      interfaces running.
  * @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.
@@ -1817,6 +1819,8 @@ struct cfg80211_ops {
                                 struct ethtool_stats *stats, u64 *data);
         void    (*get_et_strings)(struct wiphy *wiphy, struct net_device *dev,
                                   u32 sset, u8 *data);
+
+        void (*set_monitor_enabled)(struct wiphy *wiphy, bool enabled);
 };
 
 /*