{nl,cfg}80211: make peer link expiration time configurable

If a STA has a peer that it hasn't seen any tx activity
from for a certain length of time, the peer link is
expired. This means the inactive STA is removed from the
list of peers and that STA is not considered a peer again
unless it re-peers.  Previously, this inactivity time was
always 30 minutes.  Now, add it to the mesh configuration
and allow it to be configured.  Retain 30 minutes as a
default value.

Signed-off-by: Colleen Twitty <colleen@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 1f0019d..ca6facf 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -2577,6 +2577,10 @@
  *
  * @NL80211_MESHCONF_AWAKE_WINDOW: awake window duration (in TUs)
  *
+ * @NL80211_MESHCONF_PLINK_TIMEOUT: If no tx activity is seen from a STA we've
+ *	established peering with for longer than this time (in seconds), then
+ *	remove it from the STA's list of peers.  Default is 30 minutes.
+ *
  * @__NL80211_MESHCONF_ATTR_AFTER_LAST: internal use
  */
 enum nl80211_meshconf_params {
@@ -2608,6 +2612,7 @@
 	NL80211_MESHCONF_HWMP_CONFIRMATION_INTERVAL,
 	NL80211_MESHCONF_POWER_MODE,
 	NL80211_MESHCONF_AWAKE_WINDOW,
+	NL80211_MESHCONF_PLINK_TIMEOUT,
 
 	/* keep last */
 	__NL80211_MESHCONF_ATTR_AFTER_LAST,