cfg80211: clean up mesh plink station change API

Make the ability to leave the plink_state unchanged not use a
magic -1 variable that isn't in the enum, but an explicit change
flag; reject invalid plink states or actions and move the needed
constants for plink actions to the right header file. Also
reject plink_state changes for non-mesh interfaces.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index d581c6d..9b54574 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -611,22 +611,10 @@
 };
 
 /**
- * enum plink_action - actions to perform in mesh peers
- *
- * @PLINK_ACTION_INVALID: action 0 is reserved
- * @PLINK_ACTION_OPEN: start mesh peer link establishment
- * @PLINK_ACTION_BLOCK: block traffic from this mesh peer
- */
-enum plink_actions {
-	PLINK_ACTION_INVALID,
-	PLINK_ACTION_OPEN,
-	PLINK_ACTION_BLOCK,
-};
-
-/**
  * enum station_parameters_apply_mask - station parameter values to apply
  * @STATION_PARAM_APPLY_UAPSD: apply new uAPSD parameters (uapsd_queues, max_sp)
  * @STATION_PARAM_APPLY_CAPABILITY: apply new capability
+ * @STATION_PARAM_APPLY_PLINK_STATE: apply new plink state
  *
  * Not all station parameters have in-band "no change" signalling,
  * for those that don't these flags will are used.
@@ -634,6 +622,7 @@
 enum station_parameters_apply_mask {
 	STATION_PARAM_APPLY_UAPSD = BIT(0),
 	STATION_PARAM_APPLY_CAPABILITY = BIT(1),
+	STATION_PARAM_APPLY_PLINK_STATE = BIT(2),
 };
 
 /**
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index c46bb01..7dcc69f 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -884,7 +884,8 @@
  *	consisting of a nested array.
  *
  * @NL80211_ATTR_MESH_ID: mesh id (1-32 bytes).
- * @NL80211_ATTR_STA_PLINK_ACTION: action to perform on the mesh peer link.
+ * @NL80211_ATTR_STA_PLINK_ACTION: action to perform on the mesh peer link
+ *	(see &enum nl80211_plink_action).
  * @NL80211_ATTR_MPATH_NEXT_HOP: MAC address of the next hop for a mesh path.
  * @NL80211_ATTR_MPATH_INFO: information about a mesh_path, part of mesh path
  * 	info given for %NL80211_CMD_GET_MPATH, nested attribute described at
@@ -3307,6 +3308,23 @@
 	MAX_NL80211_PLINK_STATES = NUM_NL80211_PLINK_STATES - 1
 };
 
+/**
+ * enum nl80211_plink_action - actions to perform in mesh peers
+ *
+ * @NL80211_PLINK_ACTION_NO_ACTION: perform no action
+ * @NL80211_PLINK_ACTION_OPEN: start mesh peer link establishment
+ * @NL80211_PLINK_ACTION_BLOCK: block traffic from this mesh peer
+ * @NUM_NL80211_PLINK_ACTIONS: number of possible actions
+ */
+enum plink_actions {
+	NL80211_PLINK_ACTION_NO_ACTION,
+	NL80211_PLINK_ACTION_OPEN,
+	NL80211_PLINK_ACTION_BLOCK,
+
+	NUM_NL80211_PLINK_ACTIONS,
+};
+
+
 #define NL80211_KCK_LEN			16
 #define NL80211_KEK_LEN			16
 #define NL80211_REPLAY_CTR_LEN		8