Modified Wi-SUN etx to wait for Probes

Return 0xffff ETX when no probing ready
if Child direction is not probed return 1.0 to allow downward
source routing. after enough measures are made actual ETX used

Author: Mika

source/6LoWPAN/ws/ws_bootstrap.c

@@ -834,6 +834,7 @@ static void ws_bootstrap_ll_address_validate(struct protocol_interface_info_entr
  */
 uint16_t ws_etx_read(protocol_interface_info_entry_t *interface, addrtype_t addr_type, const uint8_t *addr_ptr)
 {
+    uint16_t etx;
 
     if (!addr_ptr || !interface) {
         return 0;
@@ -853,7 +854,16 @@ uint16_t ws_etx_read(protocol_interface_info_entry_t *interface, addrtype_t addr
         return 0xffff;
     }
 
-    return etx_local_etx_read(interface->id, attribute_index);
+    etx = etx_local_etx_read(interface->id, attribute_index);
+
+    // If we dont have valid ETX for children we assume good ETX.
+    // After enough packets is sent to children real calculated ETX is given.
+    // This might result in ICMP source route errors returned to Border router causing secondary route uses
+    if (etx == 0xffff && ipv6_neighbour_has_registered_by_eui64(&interface->ipv6_neighbour_cache, mac_neighbor->mac64)) {
+        return 0x100;
+    }
+
+    return etx;
 }
 bool ws_bootstrap_nd_ns_transmit(protocol_interface_info_entry_t *cur, ipv6_neighbour_t *entry,  bool unicast, uint8_t seq)
 {

source/Service_Libs/etx/etx.c

@@ -445,7 +445,7 @@ uint16_t etx_local_etx_read(int8_t interface_id, uint8_t attribute_index)
             return etx_info.max_etx;
         }
         //Not ready yet
-        return 0;
+        return 0xffff;
     }
 
     return etx_current_calc(entry->etx, entry->accumulated_failures) >> 4;