nl80211/mac80211: define and allow configuring mesh element TTL

The TTL in path selection information elements is different from
the mesh ttl used in mesh data frames.  Version 7.03 of the 11s
draft calls this ttl 'Element TTL'.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/mesh_hwmp.c

@@ -232,7 +232,7 @@ int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn,
 	*pos++ = WLAN_EID_PERR;
 	*pos++ = ie_len;
 	/* ttl */
-	*pos++ = MESH_TTL;
+	*pos++ = ttl;
 	/* number of destinations */
 	*pos++ = 1;
 	/*
@@ -522,7 +522,7 @@ static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata,
 
 	if (reply) {
 		lifetime = PREQ_IE_LIFETIME(preq_elem);
-		ttl = ifmsh->mshcfg.dot11MeshTTL;
+		ttl = ifmsh->mshcfg.element_ttl;
 		if (ttl != 0) {
 			mhwmp_dbg("replying to the PREQ\n");
 			mesh_path_sel_frame_tx(MPATH_PREP, 0, target_addr,
@@ -877,7 +877,7 @@ void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata)
 		sdata->u.mesh.last_sn_update = jiffies;
 	}
 	lifetime = default_lifetime(sdata);
-	ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;
+	ttl = sdata->u.mesh.mshcfg.element_ttl;
 	if (ttl == 0) {
 		sdata->u.mesh.mshstats.dropped_frames_ttl++;
 		spin_unlock_bh(&mpath->state_lock);
@@ -1013,5 +1013,6 @@ mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata)
 	mesh_path_sel_frame_tx(MPATH_RANN, 0, sdata->vif.addr,
 			       cpu_to_le32(++ifmsh->sn),
 			       0, NULL, 0, broadcast_addr,
-			       0, MESH_TTL, 0, 0, 0, sdata);
+			       0, sdata->u.mesh.mshcfg.element_ttl,
+			       0, 0, 0, sdata);
 }