fixed EAPOL parent selection

Parent selection now searches the best from below hysteresis signals.
if there is good signal quality signal then those override

updated border router RPL memory configuration

Author: Mika Tervonen

source/6LoWPAN/ws/ws_bbr_api.c

@@ -65,6 +65,10 @@ static void ws_bbr_rpl_root_activate(uint8_t *dodag_prefix, uint8_t *dodag_id)
     if (!protocol_6lowpan_rpl_root_dodag) {
         tr_err("RPL dodag init failed");
     }
+
+    // RPL memory limits set larger for Border router
+    rpl_control_set_memory_limits(64*1024, 0);
+
     uint8_t t_flags = PIO_A;
 
     rpl_control_update_dodag_prefix(protocol_6lowpan_rpl_root_dodag, dodag_prefix, 64, t_flags, 0xffffffff, 0xffffffff, false);

source/6LoWPAN/ws/ws_bootstrap.c

@@ -389,10 +389,18 @@ static void ws_bootstrap_pan_advertisement_analyse(struct protocol_interface_inf
 
     if(ws_bootstrap_state_discovery(cur)) {
         // Discovery state processing
+        tr_info("potential parent addr:%s panid:%x signal:%d", trace_array(data->SrcAddr, 8),data->SrcPANId, data->signal_dbm);
+
         // This parent is selected and used for authentication.
         if (memcmp(cur->ws_info->parent_info.addr, ADDR_UNSPECIFIED,8) != 0) {
 
-            // Drop if signal quality is not good enough If we hear only one advertise any quality is now ok
+            // if we dont have higher than threshold signal only signal level decides parent
+            if(ws_neighbor_class_rssi_from_dbm_calculate(cur->ws_info->parent_info.signal_dbm) < (CAND_PARENT_THRESHOLD + CAND_PARENT_HYSTERISIS) &&
+               ws_neighbor_class_rssi_from_dbm_calculate(data->signal_dbm) > ws_neighbor_class_rssi_from_dbm_calculate(cur->ws_info->parent_info.signal_dbm)) {
+                // automatically select the best quality link from the below threshold
+                goto parent_selected;
+            }
+            // Drop if signal quality is not good enough
             if(ws_neighbor_class_rssi_from_dbm_calculate(data->signal_dbm) < (CAND_PARENT_THRESHOLD + CAND_PARENT_HYSTERISIS)) {
                 tr_info("EAPOL target dropped Link quality too low");
                 return;
@@ -412,6 +420,7 @@ static void ws_bootstrap_pan_advertisement_analyse(struct protocol_interface_inf
                 tr_info("EAPOL target dropped Lower link quality");
                 return;
             }
+
         } else {
             // First advertise heard
 
@@ -420,6 +429,8 @@ static void ws_bootstrap_pan_advertisement_analyse(struct protocol_interface_inf
                 cur->bootsrap_state_machine_cnt += trickle_params_pan_configuration.Imin*10 + randLIB_get_8bit() % 50;
             }
         }
+
+parent_selected:
         // Parent valid store information
         cur->ws_info->parent_info.ws_utt = *ws_utt;
         // Saved from unicast IE
@@ -435,7 +446,7 @@ static void ws_bootstrap_pan_advertisement_analyse(struct protocol_interface_inf
         cur->ws_info->parent_info.signal_dbm = data->signal_dbm;
         memcpy(cur->ws_info->parent_info.addr, data->SrcAddr,8);
 
-        tr_info("New possible parent found addr:%s", trace_array(cur->ws_info->parent_info.addr, 8));
+        tr_info("New parent addr:%s panid:%x signal:%d", trace_array(cur->ws_info->parent_info.addr, 8),cur->ws_info->parent_info.pan_id, cur->ws_info->parent_info.signal_dbm);
         return;
     }
     // Active state processing