Update the metric container correctly. Use only one ETX initializer.

core/net/rpl/rpl-dag.c

@@ -94,8 +94,6 @@ static rpl_of_t * const objective_functions[] = {&RPL_OF};
 #define RPL_DIO_INTERVAL_DOUBLINGS      RPL_CONF_DIO_INTERVAL_DOUBLINGS
 #endif /* !RPL_CONF_DIO_INTERVAL_DOUBLINGS */
 
-#define INITIAL_ETX  NEIGHBOR_INFO_ETX_DIVISOR * 5
-
 /************************************************************************/
 /* Allocate parents from the same static MEMB chunk to reduce memory waste. */
 MEMB(parent_memb, struct rpl_parent, RPL_MAX_PARENTS);
@@ -309,7 +307,7 @@ rpl_add_parent(rpl_dag_t *dag, rpl_dio_t *dio, uip_ipaddr_t *addr)
   memcpy(&p->addr, addr, sizeof(p->addr));
   p->dag = dag;
   p->rank = dio->rank;
-  p->etx = INITIAL_ETX;
+  p->link_metric = INITIAL_LINK_METRIC;
   p->dtsn = 0;
 
   memcpy(&p->mc, &dio->mc, sizeof(p->mc));
@@ -459,8 +457,6 @@ join_dag(uip_ipaddr_t *from, rpl_dio_t *dio)
   }
   PRINTF("succeeded\n");
 
-  p->etx = INITIAL_ETX; /* The lowest confidence for new parents. */
-
   /* Determine the objective function by using the
      objective code point of the DIO. */
   of = rpl_find_of(dio->ocp);
@@ -733,7 +729,7 @@ rpl_process_dio(uip_ipaddr_t *from, rpl_dio_t *dio)
       PRINTF(")\n");
       return;
     }
-    
+
     PRINTF("RPL: New candidate parent with rank %u: ", (unsigned)p->rank);
     PRINT6ADDR(from);
     PRINTF("\n");
@@ -743,7 +739,8 @@ rpl_process_dio(uip_ipaddr_t *from, rpl_dio_t *dio)
   }
   
   /* We have allocated a candidate parent; process the DIO further. */
-  
+
+  memcpy(&p->mc, &dio->mc, sizeof(p->mc));    
   p->rank = dio->rank;
   if(rpl_process_parent_event(dag, p) == 0) {
     /* The candidate parent no longer exists. */

core/net/rpl/rpl-of-etx.c

@@ -66,7 +66,7 @@ rpl_of_t rpl_of_etx = {
 
 #define NI_ETX_TO_RPL_ETX(etx)						\
 	((etx) * (RPL_DAG_MC_ETX_DIVISOR / NEIGHBOR_INFO_ETX_DIVISOR))
-#define rpl_path_metric_tO_NI_ETX(etx)						\
+#define RPL_ETX_TO_NI_ETX(etx)					\
 	((etx) / (RPL_DAG_MC_ETX_DIVISOR / NEIGHBOR_INFO_ETX_DIVISOR))
 
 /* Reject parents that have a higher link metric than the following. */
@@ -75,9 +75,6 @@ rpl_of_t rpl_of_etx = {
 /* Reject parents that have a higher path cost than the following. */
 #define MAX_PATH_COST			100
 
-/* An initial guess of the link metric. */
-#define INITIAL_LINK_METRIC		3
-
 /*
  * The rank must differ more than 1/PARENT_SWITCH_THRESHOLD_DIV in order
  * to switch preferred parent.
@@ -89,7 +86,10 @@ typedef uint16_t rpl_path_metric_t;
 static uint16_t
 calculate_path_metric(rpl_parent_t *p)
 {
-  return p->mc.obj.etx + NI_ETX_TO_RPL_ETX(p->etx);
+  if(p->mc.obj.etx == 0 && p->rank > ROOT_RANK(p->dag)) {
+    return MAX_PATH_COST * RPL_DAG_MC_ETX_DIVISOR;
+  }
+  return p->mc.obj.etx + NI_ETX_TO_RPL_ETX(p->link_metric);
 }
 
 static void
@@ -112,12 +112,9 @@ calculate_rank(rpl_parent_t *p, rpl_rank_t base_rank)
     if(base_rank == 0) {
       return INFINITE_RANK;
     }
-    rank_increase = INITIAL_LINK_METRIC * DEFAULT_MIN_HOPRANKINC;
+    rank_increase = NEIGHBOR_INFO_FIX2ETX(INITIAL_LINK_METRIC) * DEFAULT_MIN_HOPRANKINC;
   } else {
-    if(p->etx == 0) {
+    rank_increase = NEIGHBOR_INFO_FIX2ETX(p->link_metric) * p->dag->min_hoprankinc;
-      p->etx = INITIAL_LINK_METRIC * NEIGHBOR_INFO_ETX_DIVISOR;
-    }
-    rank_increase = (p->etx * p->dag->min_hoprankinc) / NEIGHBOR_INFO_ETX_DIVISOR;
     if(base_rank == 0) {
       base_rank = p->rank;
     }
@@ -180,6 +177,10 @@ update_metric_container(rpl_dag_t *dag)
   } else {
     dag->mc.obj.etx = calculate_path_metric(dag->preferred_parent);
   }
+
+  PRINTF("RPL: My path ETX to the root is %u.%u\n",
+	dag->mc.obj.etx / RPL_DAG_MC_ETX_DIVISOR,
+	(dag->mc.obj.etx % RPL_DAG_MC_ETX_DIVISOR * 100) / RPL_DAG_MC_ETX_DIVISOR);
 #elif RPL_DAG_MC == RPL_DAG_MC_ENERGY
   dag->mc.type = RPL_DAG_MC_ENERGY;
   dag->mc.flags = RPL_DAG_MC_FLAG_P;
@@ -195,8 +196,4 @@ update_metric_container(rpl_dag_t *dag)
 #else
 #error "Unsupported RPL_DAG_MC configured. See rpl.h."
 #endif /* RPL_DAG_MC */
-
-  PRINTF("RPL: My path ETX to the root is %u.%u\n",
-	dag->mc.obj.etx / RPL_DAG_MC_ETX_DIVISOR,
-	(dag->mc.obj.etx % RPL_DAG_MC_ETX_DIVISOR * 100) / RPL_DAG_MC_ETX_DIVISOR);
 }

core/net/rpl/rpl-private.h

@@ -127,6 +127,8 @@
 
 #define INFINITE_RANK                   0xffff
 
+#define INITIAL_LINK_METRIC		NEIGHBOR_INFO_ETX2FIX(5)
+
 /* Represents 2^n ms. */
 /* Default value according to the specification is 3 which
    means 8 milliseconds, but that is an unreasonable value if

core/net/rpl/rpl.c

@@ -148,11 +148,10 @@ rpl_link_neighbor_callback(const rimeaddr_t *addr, int known, int etx)
     return;
   }
 
-  if(etx != parent->etx) {
+  /* Trigger DAG rank recalculation. */
-    /* Trigger DAG rank recalculation. */
+  parent->updated = 1;
-    parent->updated = 1;
+
-  }
+  parent->link_metric = etx;
-  parent->etx = etx;
 
   if(dag->of->parent_state_callback != NULL) {
     dag->of->parent_state_callback(parent, known, etx);
@@ -163,7 +162,6 @@ rpl_link_neighbor_callback(const rimeaddr_t *addr, int known, int etx)
     PRINT6ADDR(&parent->addr);
     PRINTF(" because of bad connectivity (ETX %d)\n", etx);
     parent->rank = INFINITE_RANK;
-    parent->updated = 1;
   }
 }
 /************************************************************************/

core/net/rpl/rpl.h

@@ -147,7 +147,7 @@ struct rpl_parent {
   rpl_metric_container_t mc;
   uip_ipaddr_t addr;
   rpl_rank_t rank;
-  uint8_t etx;
+  uint8_t link_metric;
   uint8_t dtsn;
   uint8_t updated;
 };