Support for Contiki RPL metrics - RFC6551

core/net/rpl/rpl-icmp6.c

@@ -62,6 +62,46 @@
 #define DEBUG DEBUG_PRINT
 
 #include "net/ip/uip-debug.h"
+#include "net/nbr-table.h"
+
+
+	static void reset(rpl_dag_t *);
+	static void neighbor_link_callback(rpl_parent_t *, int, int);
+	static rpl_parent_t *best_parent(rpl_parent_t *, rpl_parent_t *);
+	static rpl_dag_t *best_dag(rpl_dag_t *, rpl_dag_t *);
+	static rpl_rank_t calculate_rank(rpl_parent_t *, rpl_rank_t);
+	static void update_metric_container(rpl_instance_t *);
+
+	rpl_of_t rpl_mrhof = {
+	  reset,
+	  neighbor_link_callback,
+	  best_parent,
+	  best_dag,
+	  calculate_rank,
+	  update_metric_container,
+	  1
+	};
+
+	/* Constants for the ETX moving average */
+	#define ETX_SCALE   100
+	#define ETX_ALPHA   90
+
+
+
+	/* Reject parents that have a higher link metric than the following. */
+	#define MAX_LINK_METRIC			10
+
+
+	/* Reject parents that have a higher path cost than the following. */
+	#define MAX_PATH_COST			100
+
+	/*
+	 * The rank must differ more than 1/PARENT_SWITCH_THRESHOLD_DIV in order
+	 * to switch preferred parent.
+	 */
+	#define PARENT_SWITCH_THRESHOLD_DIV	2
+
+
 
 /*---------------------------------------------------------------------------*/
 #define RPL_DIO_GROUNDED                 0x80
@@ -79,8 +119,191 @@ static void dao_input(void);
 static void dao_ack_input(void);
 static void dco_input(void);
 static void dco_ack_input(void);
+/*----------------------------------------------------------------------------*/
+typedef uint16_t rpl_path_metric_t;
+
+	static rpl_path_metric_t
+	calculate_path_metric(rpl_parent_t *p)
+		{
+  if(p == NULL) {
+    return MAX_PATH_COST * RPL_DAG_MC_ETX_DIVISOR;
+  }
+
+#if RPL_DAG_MC == RPL_DAG_MC_NONE
+  return p->rank + (uint16_t)p->link_metric;
+#elif RPL_DAG_MC == RPL_DAG_MC_ETX
+  return p->mc.obj.etx + (uint16_t)p->link_metric;
+#elif RPL_DAG_MC == RPL_DAG_MC_ENERGY
+  return p->mc.obj.energy.energy_est + (uint16_t)p->link_metric;
+#else
+#error "Unsupported RPL_DAG_MC configured. See rpl.h."
+#endif /* RPL_DAG_MC */
+}
 
+static void
+reset(rpl_dag_t *sag)
+{
+  PRINTF("RPL: Reset MRHOF\n");
+}
 
+static void
+neighbor_link_callback(rpl_parent_t *p, int status, int numtx)
+{
+  uint16_t recorded_etx = p->link_metric;
+  uint16_t packet_etx = numtx * RPL_DAG_MC_ETX_DIVISOR;
+  uint16_t new_etx;
+
+  /* Do not penalize the ETX when collisions or transmission errors occur. */
+  if(status == MAC_TX_OK || status == MAC_TX_NOACK) {
+    if(status == MAC_TX_NOACK) {
+      packet_etx = MAX_LINK_METRIC * RPL_DAG_MC_ETX_DIVISOR;
+    }
+
+    new_etx = ((uint32_t)recorded_etx * ETX_ALPHA +
+               (uint32_t)packet_etx * (ETX_SCALE - ETX_ALPHA)) / ETX_SCALE;
+
+    PRINTF("RPL: ETX changed from %u to %u (packet ETX = %u)\n",
+        (unsigned)(recorded_etx / RPL_DAG_MC_ETX_DIVISOR),
+        (unsigned)(new_etx  / RPL_DAG_MC_ETX_DIVISOR),
+        (unsigned)(packet_etx / RPL_DAG_MC_ETX_DIVISOR));
+    p->link_metric = new_etx;
+  }
+}
+
+static rpl_rank_t
+calculate_rank(rpl_parent_t *p, rpl_rank_t base_rank)
+{
+  rpl_rank_t new_rank;
+  rpl_rank_t rank_increase;
+
+  if(p == NULL) {
+    if(base_rank == 0) {
+      return INFINITE_RANK;
+    }
+    rank_increase = RPL_INIT_LINK_METRIC * RPL_DAG_MC_ETX_DIVISOR;
+  } else {
+    rank_increase = p->link_metric;
+    if(base_rank == 0) {
+      base_rank = p->rank;
+    }
+  }
+
+  if(INFINITE_RANK - base_rank < rank_increase) {
+    /* Reached the maximum rank. */
+    new_rank = INFINITE_RANK;
+  } else {
+   /* Calculate the rank based on the new rank information from DIO or
+      stored otherwise. */
+    new_rank = base_rank + rank_increase;
+  }
+
+  return new_rank;
+}
+
+static rpl_dag_t *
+best_dag(rpl_dag_t *d1, rpl_dag_t *d2)
+{
+  if(d1->grounded != d2->grounded) {
+    return d1->grounded ? d1 : d2;
+  }
+
+  if(d1->preference != d2->preference) {
+    return d1->preference > d2->preference ? d1 : d2;
+  }
+
+  return d1->rank < d2->rank ? d1 : d2;
+}
+
+static rpl_parent_t *
+best_parent(rpl_parent_t *p1, rpl_parent_t *p2)
+{
+  rpl_dag_t *dag;
+  rpl_path_metric_t min_diff;
+  rpl_path_metric_t p1_metric;
+  rpl_path_metric_t p2_metric;
+
+  dag = p1->dag; /* Both parents are in the same DAG. */
+
+  min_diff = RPL_DAG_MC_ETX_DIVISOR /
+             PARENT_SWITCH_THRESHOLD_DIV;
+
+  p1_metric = calculate_path_metric(p1);
+  p2_metric = calculate_path_metric(p2);
+
+  /* Maintain stability of the preferred parent in case of similar ranks. */
+  if(p1 == dag->preferred_parent || p2 == dag->preferred_parent) {
+    if(p1_metric < p2_metric + min_diff &&
+       p1_metric > p2_metric - min_diff) {
+      PRINTF("RPL: MRHOF hysteresis: %u <= %u <= %u\n",
+             p2_metric - min_diff,
+             p1_metric,
+             p2_metric + min_diff);
+      return dag->preferred_parent;
+    }
+  }
+
+  return p1_metric < p2_metric ? p1 : p2;
+}
+
+#if RPL_DAG_MC == RPL_DAG_MC_NONE
+static void
+update_metric_container(rpl_instance_t *instance)
+{
+  instance->mc.type = RPL_DAG_MC;
+}
+#else
+static void
+update_metric_container(rpl_instance_t *instance)
+{
+  rpl_path_metric_t path_metric;
+  rpl_dag_t *dag;
+#if RPL_DAG_MC == RPL_DAG_MC_ENERGY
+  uint8_t type;
+#endif
+
+  instance->mc.type = RPL_DAG_MC;
+  instance->mc.flags = RPL_DAG_MC_FLAG_P;
+  instance->mc.aggr = RPL_DAG_MC_AGGR_ADDITIVE;
+  instance->mc.prec = 0;
+
+  dag = instance->current_dag;
+
+  if (!dag->joined) {
+    PRINTF("RPL: Cannot update the metric container when not joined\n");
+    return;
+  }
+
+  if(dag->rank == ROOT_RANK(instance)) {
+    path_metric = 0;
+  } else {
+    path_metric = calculate_path_metric(dag->preferred_parent);
+  }
+
+#if RPL_DAG_MC == RPL_DAG_MC_ETX
+  instance->mc.length = sizeof(instance->mc.obj.etx);
+  instance->mc.obj.etx = path_metric;
+
+  PRINTF("RPL: My path ETX to the root is %u.%u\n",
+	instance->mc.obj.etx / RPL_DAG_MC_ETX_DIVISOR,
+	(instance->mc.obj.etx % RPL_DAG_MC_ETX_DIVISOR * 100) /
+	 RPL_DAG_MC_ETX_DIVISOR);
+#elif RPL_DAG_MC == RPL_DAG_MC_ENERGY
+  instance->mc.length = sizeof(instance->mc.obj.energy);
+
+  if(dag->rank == ROOT_RANK(instance)) {
+    type = RPL_DAG_MC_ENERGY_TYPE_MAINS;
+  } else {
+    type = RPL_DAG_MC_ENERGY_TYPE_BATTERY;
+  }
+
+  instance->mc.obj.energy.flags = type << RPL_DAG_MC_ENERGY_TYPE;
+  instance->mc.obj.energy.energy_est = path_metric;
+#endif /* RPL_DAG_MC == RPL_DAG_MC_ETX */
+}
+#endif /* RPL_DAG_MC == RPL_DAG_MC_NONE */
+
+/*------------------------------------------------------------------*/
+
 static void dao_output_target_seq(rpl_parent_t *parent, uip_ipaddr_t *prefix,
                                   uint8_t lifetime, uint8_t seq_no);
 void dco_output
@@ -109,6 +332,11 @@ void RPL_DEBUG_DAO_OUTPUT(rpl_parent_t *);
 
 static uint8_t dao_sequence = RPL_LOLLIPOP_INIT;
 
+uint8_t rpl_leaf =  RPL_LEAF_ONLY;
+uint8_t leaf_dio = 0;
+
+extern rpl_of_t RPL_OF;
+
 #if RPL_WITH_DCO
 uint8_t path_sequence = RPL_LOLLIPOP_INIT;
 static uint8_t dco_sequence = RPL_LOLLIPOP_INIT;