Improved objective function API so DAG metric containers can be generated cleanly. The packet generation now asks the OF to provide a fresh logical presentation of the metric container, which is then translated to raw packet format.

core/net/rpl/rpl-dag.c

@@ -189,6 +189,8 @@ rpl_set_root(uip_ipaddr_t *dag_id)
   dag->default_lifetime = DEFAULT_RPL_DEF_LIFETIME;
   dag->lifetime_unit = DEFAULT_RPL_LIFETIME_UNIT;
 
+  dag->of->update_metric_container(dag);
+
   PRINTF("RPL: Node set to be a DAG root with DAG ID ");
   PRINT6ADDR(&dag->dag_id);
   PRINTF("\n");
@@ -300,6 +302,8 @@ rpl_add_parent(rpl_dag_t *dag, rpl_dio_t *dio, uip_ipaddr_t *addr)
   p->etx = INITIAL_ETX;
   p->dtsn = 0;
 
+  memcpy(&p->mc, &dio->mc, sizeof(p->mc));
+
   list_add(dag->parents, p);
 
   return p;
@@ -337,6 +341,7 @@ rpl_select_parent(rpl_dag_t *dag)
 
   if(dag->preferred_parent != best) {
     dag->preferred_parent = best; /* Cache the value. */
+    dag->of->update_metric_container(dag);
     rpl_set_default_route(dag, &best->addr);
     /* The DAO parent set changed - schedule a DAO transmission. */
     rpl_schedule_dao(dag);
@@ -482,6 +487,7 @@ join_dag(uip_ipaddr_t *from, rpl_dio_t *dio)
 
   dag->version = dio->version;
   dag->preferred_parent = p;
+  dag->of->update_metric_container(dag);
 
   dag->dio_intdoubl = dio->dag_intdoubl;
   dag->dio_intmin = dio->dag_intmin;

core/net/rpl/rpl-icmp6.c

@@ -236,6 +236,8 @@ dio_input(void)
       return;
     }
 
+    PRINTF("RPL: DIO suboption %u, length: %u\n", subopt_type, len - 2);
+
     switch(subopt_type) {
     case RPL_DIO_SUBOPT_DAG_METRIC_CONTAINER:
       if(len < 6) {
@@ -243,13 +245,25 @@ dio_input(void)
 	RPL_STAT(rpl_stats.malformed_msgs++);
         return;
       }
-      dio.metric_container.type = buffer[i + 2];
+      dio.mc.type = buffer[i + 2];
-      dio.metric_container.flags = buffer[i + 3];
+      dio.mc.flags = buffer[i + 3];
-      dio.metric_container.aggr = buffer[i + 4] >> 4;
+      dio.mc.aggr = buffer[i + 4] >> 4;
-      dio.metric_container.prec = buffer[i + 4] & 0xf;
+      dio.mc.prec = buffer[i + 4] & 0xf;
-      dio.metric_container.length = buffer[i + 5];
+      dio.mc.length = buffer[i + 5];
-      if(dio.metric_container.type == RPL_DAG_MC_ETX) {
+      if(dio.mc.type == RPL_DAG_MC_ETX) {
-        dio.metric_container.etx.etx = buffer[i + 6];
+        dio.mc.etx.etx = buffer[i + 6] << 8;
+        dio.mc.etx.etx |= buffer[i + 7];
+
+        PRINTF("RPL: DAG MC: type %u, flags %u, aggr %u, prec %u, length %u, ETX %u\n",
+	       (unsigned)dio.mc.type,  
+	       (unsigned)dio.mc.flags, 
+	       (unsigned)dio.mc.aggr, 
+	       (unsigned)dio.mc.prec, 
+	       (unsigned)dio.mc.length, 
+	       (unsigned)dio.mc.etx.etx);
+      } else {
+       PRINTF("RPL: Unhandled DAG MC type: %u\n", (unsigned)dio.mc.type);
+       return;
       }
       break;
     case RPL_DIO_SUBOPT_ROUTE_INFO:
@@ -313,6 +327,9 @@ dio_input(void)
       PRINTF("RPL: Copying prefix information\n");
       memcpy(&dio.prefix_info.prefix, &buffer[i + 16], 16);
       break;
+    default:
+      PRINTF("RPL: Unsupported suboption type in DIO: %u\n",
+	(unsigned)subopt_type);
     }
   }
 
@@ -352,6 +369,26 @@ dio_output(rpl_dag_t *dag, uip_ipaddr_t *uc_addr)
   memcpy(buffer + pos, &dag->dag_id, sizeof(dag->dag_id));
   pos += 16;
 
+  if(dag->mc.type != RPL_DAG_MC_NONE) {
+    dag->of->update_metric_container(dag);
+
+    buffer[pos++] = RPL_DIO_SUBOPT_DAG_METRIC_CONTAINER;
+    buffer[pos++] = 6;
+    buffer[pos++] = dag->mc.type;
+    buffer[pos++] = dag->mc.flags;
+    buffer[pos] = dag->mc.aggr << 4;
+    buffer[pos++] |= dag->mc.prec;
+    if(dag->mc.type == RPL_DAG_MC_ETX) {
+      buffer[pos++] = 2;
+      buffer[pos++] = dag->mc.etx.etx >> 8;
+      buffer[pos++] = dag->mc.etx.etx & 0xff;
+    } else {
+      PRINTF("RPL: Unable to send DIO because of unhandled DAG MC type %u\n",
+	(unsigned)dag->mc.type);
+      return;
+    }
+  }
+
   /* always add a sub-option for DAG configuration */
   buffer[pos++] = RPL_DIO_SUBOPT_DAG_CONF;
   buffer[pos++] = 14;

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

@@ -53,15 +53,22 @@ static void reset(rpl_dag_t *);
 static void parent_state_callback(rpl_parent_t *, int, int);
 static rpl_parent_t *best_parent(rpl_parent_t *, rpl_parent_t *);
 static rpl_rank_t calculate_rank(rpl_parent_t *, rpl_rank_t);
+static void update_metric_container(rpl_dag_t *);
 
 rpl_of_t rpl_of_etx = {
   reset,
   parent_state_callback,
   best_parent,
   calculate_rank,
+  update_metric_container,
   1
 };
 
+#define NI_ETX_TO_RPL_ETX(etx)						\
+	((etx) * (RPL_DAG_MC_ETX_DIVISOR / NEIGHBOR_INFO_ETX_DIVISOR))
+#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. */
 #define MAX_LINK_METRIC			10
 
@@ -77,15 +84,21 @@ rpl_of_t rpl_of_etx = {
  */
 #define PARENT_SWITCH_THRESHOLD_DIV	2
 
-#define MAX_DIFFERENCE(dag)				\
+typedef uint16_t rpl_etx_t;
-	((dag)->min_hoprankinc / PARENT_SWITCH_THRESHOLD_DIV)
+#define MAX_ETX 65535
 
-static rpl_rank_t min_path_cost = INFINITE_RANK;
+static rpl_etx_t min_path_cost = MAX_ETX;
+
+static uint16_t
+calculate_etx(rpl_parent_t *p)
+{
+  return p->mc.etx.etx + NI_ETX_TO_RPL_ETX(p->etx);
+}
 
 static void
 reset(rpl_dag_t *dag)
 {
-  min_path_cost = INFINITE_RANK;
+  min_path_cost = MAX_ETX;
 }
 
 static void
@@ -120,14 +133,6 @@ calculate_rank(rpl_parent_t *p, rpl_rank_t base_rank)
     }
   }
 
-  PRINTF("RPL: MRHOF calculate rank, base rank = %u, rank_increase = %u\n",
-	 (unsigned)base_rank, rank_increase);
-
-  if(base_rank < min_path_cost) {
-    min_path_cost = base_rank;
-    PRINTF("RPL: min_path_cost updated to %u\n", min_path_cost);
-  }
-
   if(INFINITE_RANK - base_rank < rank_increase) {
     /* Reached the maximum rank. */
     new_rank = INFINITE_RANK;
@@ -137,8 +142,6 @@ calculate_rank(rpl_parent_t *p, rpl_rank_t base_rank)
     new_rank = base_rank + rank_increase;
   }
 
-  PRINTF("RPL: Path cost %u\n", (unsigned)new_rank);
-
   return new_rank;
 }
 
@@ -146,27 +149,50 @@ static rpl_parent_t *
 best_parent(rpl_parent_t *p1, rpl_parent_t *p2)
 {
   rpl_dag_t *dag;
-  rpl_rank_t p1_rank;
+  rpl_etx_t min_diff;
-  rpl_rank_t p2_rank;
+  rpl_etx_t p1_etx;
+  rpl_etx_t p2_etx;
 
-  dag = (rpl_dag_t *)p1->dag; /* Both parents must be in the same DAG. */
+  dag = p1->dag; /* Both parents must be in the same DAG. */
 
-  p1_rank = calculate_rank(p1, 0);
+  min_diff = RPL_DAG_MC_ETX_DIVISOR / 
-  p2_rank = calculate_rank(p2, 0);
+                           PARENT_SWITCH_THRESHOLD_DIV;
+
+  p1_etx = calculate_etx(p1);
+  p2_etx = calculate_etx(p2);
 
   /* Maintain stability of the preferred parent in case of similar ranks. */
-  if(p1_rank < p2_rank + MAX_DIFFERENCE(dag) &&
+  if(p1_etx < p2_etx + min_diff &&
-     p1_rank > p2_rank - MAX_DIFFERENCE(dag)) {
+     p1_etx > p2_etx - min_diff) {
     PRINTF("RPL: MRHOF hysteresis: %u <= %u <= %u\n",
-           p2_rank - MAX_DIFFERENCE(dag),
+           p2_etx - min_diff,
-           p1_rank,
+           p1_etx,
-           p2_rank + MAX_DIFFERENCE(dag));
+           p2_etx + min_diff);
     return dag->preferred_parent;
   }
 
-  if(p1_rank < p2_rank) {
+  if(p1_etx < p2_etx) {
     return p1;
   }
 
   return p2;
 }
+
+static void
+update_metric_container(rpl_dag_t *dag)
+{
+  dag->mc.type = RPL_DAG_MC_ETX;
+  dag->mc.flags = RPL_DAG_MC_FLAG_P;
+  dag->mc.aggr = RPL_DAG_MC_AGGR_ADDITIVE;
+  dag->mc.prec = 0;
+  dag->mc.length = sizeof(dag->mc.etx.etx);
+  if(dag->rank == ROOT_RANK) {
+    dag->mc.etx.etx = 0;
+  } else {
+    dag->mc.etx.etx = calculate_etx(dag->preferred_parent);
+  }
+
+  PRINTF("RPL: My path ETX to the root is %u.%u\n",
+	dag->mc.etx.etx / RPL_DAG_MC_ETX_DIVISOR,
+	(dag->mc.etx.etx % RPL_DAG_MC_ETX_DIVISOR * 100) / RPL_DAG_MC_ETX_DIVISOR);
+}

core/net/rpl/rpl-of0.c

@@ -41,7 +41,7 @@
 
 #include "net/rpl/rpl-private.h"
 
-#define DEBUG DEBUG_ANNOTATE
+#define DEBUG DEBUG_NONE
 #include "net/uip-debug.h"
 
 #include "net/neighbor-info.h"
@@ -49,12 +49,14 @@
 static void reset(rpl_dag_t *);
 static rpl_parent_t *best_parent(rpl_parent_t *, rpl_parent_t *);
 static rpl_rank_t calculate_rank(rpl_parent_t *, rpl_rank_t);
+static void update_metric_container(rpl_dag_t *);
 
 rpl_of_t rpl_of0 = {
   reset,
   NULL,
   best_parent,
   calculate_rank,
+  update_metric_container,
   0
 };
 
@@ -123,3 +125,9 @@ best_parent(rpl_parent_t *p1, rpl_parent_t *p2)
     return p2;
   }
 }
+
+static void
+update_metric_container(rpl_dag_t *dag)
+{
+  dag->mc.type = RPL_DAG_MC_NONE;
+}

core/net/rpl/rpl-private.h

@@ -158,28 +158,6 @@
 #define RPL_MOP_STORING_MULTICAST       3
 #define RPL_MOP_DEFAULT                 RPL_MOP_STORING_NO_MULTICAST
 
-/* DAG Metric Container Object Types, to be confirmed by IANA. */
-#define RPL_DAG_MC_NSA                  1 /* Node State and Attributes */
-#define RPL_DAG_MC_NE                   2 /* Node Energy */
-#define RPL_DAG_MC_HC                   3 /* Hop Count */
-#define RPL_DAG_MC_THROUGHPUT           4 /* Throughput */
-#define RPL_DAG_MC_LATENCY              5 /* Latency */
-#define RPL_DAG_MC_LQL                  6 /* Link Quality Level */
-#define RPL_DAG_MC_ETX                  7 /* Expected Transmission Count */
-#define RPL_DAG_MC_LC                   8 /* Link Color */
-
-/* DAG Metric Container flags. */
-#define RPL_DAG_MC_FLAG_P		0x8
-#define RPL_DAG_MC_FLAG_C		0x4
-#define RPL_DAG_MC_FLAG_O		0x2
-#define RPL_DAG_MC_FLAG_R		0x1
-
-/* DAG Metric Container aggregation mode. */
-#define RPL_DAG_MC_AGGR_ADDITIVE	0
-#define RPL_DAG_MC_AGGR_MAXIMUM		1
-#define RPL_DAG_MC_AGGR_MINIMUM		2
-#define RPL_DAG_MC_AGGR_MULTIPLICATIVE	3
-
 /*
  * The ETX in the metric container is expressed as a fixed-point value 
  * whose integer part can be obtained by dividing the value by 
@@ -196,23 +174,6 @@
 #endif
 #define RPL_DIS_START_DELAY             5
 /*---------------------------------------------------------------------------*/
-/* Logical representation of an ETX object in a DAG Metric Container. */
-struct rpl_metric_object_etx {
-  uint16_t etx;
-};
-
-/* Logical representation of a DAG Metric Container. */
-struct rpl_metric_container {
-  uint8_t type;
-  uint8_t flags;
-  uint8_t aggr;
-  uint8_t prec;
-  uint8_t length;
-  /* Once we support more objects, the etx field will be replaced by a 
-     union of those. */
-  struct rpl_metric_object_etx etx;
-};
-
 /* Logical representation of a DAG Information Object (DIO.) */
 struct rpl_dio {
   uip_ipaddr_t dag_id;
@@ -233,7 +194,7 @@ struct rpl_dio {
   rpl_rank_t dag_min_hoprankinc;
   rpl_prefix_t destination_prefix;
   rpl_prefix_t prefix_info;
-  struct rpl_metric_container metric_container;
+  struct rpl_metric_container mc;
 };
 typedef struct rpl_dio rpl_dio_t;
 

core/net/rpl/rpl.h

@@ -74,11 +74,55 @@
 typedef uint16_t rpl_rank_t;
 typedef uint16_t rpl_ocp_t;
 
+/*---------------------------------------------------------------------------*/
+/* DAG Metric Container Object Types, to be confirmed by IANA. */
+#define RPL_DAG_MC_NONE			0 /* Local identifier for empty MC */
+#define RPL_DAG_MC_NSA                  1 /* Node State and Attributes */
+#define RPL_DAG_MC_NE                   2 /* Node Energy */
+#define RPL_DAG_MC_HC                   3 /* Hop Count */
+#define RPL_DAG_MC_THROUGHPUT           4 /* Throughput */
+#define RPL_DAG_MC_LATENCY              5 /* Latency */
+#define RPL_DAG_MC_LQL                  6 /* Link Quality Level */
+#define RPL_DAG_MC_ETX                  7 /* Expected Transmission Count 
+*/
+#define RPL_DAG_MC_LC                   8 /* Link Color */
+
+/* DAG Metric Container flags. */
+#define RPL_DAG_MC_FLAG_P               0x8
+#define RPL_DAG_MC_FLAG_C               0x4
+#define RPL_DAG_MC_FLAG_O               0x2
+#define RPL_DAG_MC_FLAG_R               0x1
+
+/* DAG Metric Container aggregation mode. */
+#define RPL_DAG_MC_AGGR_ADDITIVE        0
+#define RPL_DAG_MC_AGGR_MAXIMUM         1
+#define RPL_DAG_MC_AGGR_MINIMUM         2
+#define RPL_DAG_MC_AGGR_MULTIPLICATIVE  3
+
+/* Logical representation of an ETX object in a DAG Metric Container. */
+struct rpl_metric_object_etx {
+  uint16_t etx;
+};
+
+/* Logical representation of a DAG Metric Container. */
+struct rpl_metric_container {
+  uint8_t type;
+  uint8_t flags;
+  uint8_t aggr;
+  uint8_t prec;
+  uint8_t length;
+  /* Once we support more objects, the etx field will be replaced by a
+     union of those. */
+  struct rpl_metric_object_etx etx;
+};
+typedef struct rpl_metric_container rpl_metric_container_t;
+/*---------------------------------------------------------------------------*/
 struct rpl_dag;
 /*---------------------------------------------------------------------------*/
 struct rpl_parent {
   struct rpl_parent *next;
   struct rpl_dag *dag;
+  rpl_metric_container_t mc;
   uip_ipaddr_t addr;
   rpl_rank_t rank;
   uint8_t etx;
@@ -111,12 +155,20 @@ typedef struct rpl_parent rpl_parent_t;
  *  If "parent" is NULL, the objective function selects a default increment
  *  that is adds to the "base_rank". Otherwise, the OF uses information known
  *  about "parent" to select an increment to the "base_rank".
+ *
+ * update_metric_container(dag)
+ *
+ *  Updates the metric container for outgoing DIOs in a certain DAG.
+ *  If the objective function of the DAG does not use metric containers, 
+ *  the function returns 0. If the metric container has been filled, the 
+ *  function returns 1.
  */
 struct rpl_of {
   void (*reset)(struct rpl_dag *);
   void (*parent_state_callback)(rpl_parent_t *, int, int);
   rpl_parent_t *(*best_parent)(rpl_parent_t *, rpl_parent_t *);
   rpl_rank_t (*calculate_rank)(rpl_parent_t *, rpl_rank_t);
+  void (*update_metric_container)(struct rpl_dag *);
   rpl_ocp_t ocp;
 };
 typedef struct rpl_of rpl_of_t;
@@ -133,6 +185,7 @@ typedef struct rpl_prefix rpl_prefix_t;
 /* Directed Acyclic Graph */
 struct rpl_dag {
   /* DAG configuration */
+  rpl_metric_container_t mc;
   rpl_of_t *of;
   uip_ipaddr_t dag_id;
   /* The current default router - used for routing "upwards" */