nl80211: add API to probe a client

When the AP SME in hostapd is used it wants to
probe the clients when they have been idle for
some time. Add explicit API to support this.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index ff39e4b..901a70d 100644
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -519,6 +519,14 @@
  *	If used as the command it must have an interface index and you can
  *	only unsubscribe from the event by closing the socket.
  *
+ * @NL80211_CMD_PROBE_CLIENT: Probe an associated station on an AP interface
+ *	by sending a null data frame to it and reporting when the frame is
+ *	acknowleged. This is used to allow timing out inactive clients. Uses
+ *	%NL80211_ATTR_IFINDEX and %NL80211_ATTR_MAC. The command returns a
+ *	direct reply with an %NL80211_ATTR_COOKIE that is later used to match
+ *	up the event with the request. The event includes the same data and
+ *	has %NL80211_ATTR_ACK set if the frame was ACKed.
+ *
  * @NL80211_CMD_MAX: highest used command number
  * @__NL80211_CMD_AFTER_LAST: internal use
  */
@@ -650,6 +658,8 @@
 
 	NL80211_CMD_UNEXPECTED_FRAME,
 
+	NL80211_CMD_PROBE_CLIENT,
+
 	/* add new commands above here */
 
 	/* used to define NL80211_CMD_MAX below */