added nbr policy for Contiki RPL that avoids thrashing the nbr table with new entries all the time

core/net/rpl/rpl-conf.h

@@ -245,6 +245,18 @@
 #define RPL_WITH_DAO_ACK 1
 #endif /* RPL_CONF_WITH_DAO_ACK */
 
+/*
+ * Setting the DIO_REFRESH_DAO_ROUTES will make RPL always increase
+ * the DTSN (Destination Advertisement Trigger Sequence Number) when
+ * sending broadcast DIO. This is to get all children to re-register
+ * their DAO route.
+ * */
+#ifdef RPL_CONF_DIO_REFRESH_DAO_ROUTES
+#define RPL_DIO_REFRESH_DAO_ROUTES RPL_CONF_DIO_REFRESH_DAO_ROUTES
+#else
+#define RPL_DIO_REFRESH_DAO_ROUTES 0
+#endif /* RPL_CONF_DIO_REFRESH_DAO_ROUTES */
+
 /*
  * RPL probing. When enabled, probes will be sent periodically to keep
  * parent link estimates up to date.

core/net/rpl/rpl-dag.c

@@ -1174,6 +1174,8 @@ rpl_local_repair(rpl_instance_t *instance)
   }
 
   rpl_reset_dio_timer(instance);
+  /* Request refresh of DAO registrations next DIO */
+  RPL_LOLLIPOP_INCREMENT(instance->dtsn_out);
 
   RPL_STAT(rpl_stats.local_repairs++);
 }
@@ -1250,6 +1252,23 @@ rpl_process_parent_event(rpl_instance_t *instance, rpl_parent_t *p)
   return return_value;
 }
 /*---------------------------------------------------------------------------*/
+static int
+add_nbr_from_dio(uip_ipaddr_t *from, rpl_dio_t *dio)
+{
+  /* check if it is ok to add this nbr based on this DIO */
+  if(RPL_NBR_POLICY.check_add_from_dio(from, dio)) {
+    /* add this to the neighbor cache if not already there */
+    if(rpl_icmp6_update_nbr_table(from) == NULL) {
+      PRINTF("RPL: Out of memory, dropping DIO from ");
+      PRINT6ADDR(from);
+      PRINTF("\n");
+      return 0;
+    }
+    return 1;
+  }
+  return 0;
+}
+/*---------------------------------------------------------------------------*/
 void
 rpl_process_dio(uip_ipaddr_t *from, rpl_dio_t *dio)
 {
@@ -1303,7 +1322,11 @@ rpl_process_dio(uip_ipaddr_t *from, rpl_dio_t *dio)
 
   if(instance == NULL) {
     PRINTF("RPL: New instance detected (ID=%u): Joining...\n", dio->instance_id);
+    if(add_nbr_from_dio(from, dio)) {
       rpl_join_instance(from, dio);
+    } else {
+      PRINTF("RPL: Not joining since could not add parent\n");
+    }
     return;
   }
 
@@ -1315,6 +1338,10 @@ rpl_process_dio(uip_ipaddr_t *from, rpl_dio_t *dio)
   if(dag == NULL) {
 #if RPL_MAX_DAG_PER_INSTANCE > 1
     PRINTF("RPL: Adding new DAG to known instance.\n");
+    if(!add_nbr_from_dio(from, dio)) {
+      PRINTF("RPL: Could not add new DAG, could not add parent\n");
+      return;
+    }
     dag = rpl_add_dag(from, dio);
     if(dag == NULL) {
       PRINTF("RPL: Failed to add DAG.\n");
@@ -1363,6 +1390,11 @@ rpl_process_dio(uip_ipaddr_t *from, rpl_dio_t *dio)
    * whether to keep it in the set.
    */
 
+  if(!add_nbr_from_dio(from, dio)) {
+    PRINTF("RPL: Could not add parent based on DIO\n");
+    return;
+  }
+
   p = rpl_find_parent(dag, from);
   if(p == NULL) {
     previous_dag = find_parent_dag(instance, from);

core/net/rpl/rpl-icmp6.c

@@ -88,7 +88,6 @@ void RPL_DEBUG_DIO_INPUT(uip_ipaddr_t *, rpl_dio_t *);
 void RPL_DEBUG_DAO_OUTPUT(rpl_parent_t *);
 #endif
 
-/* TODO: should these variables be a part of the instance? */
 static uint8_t dao_sequence = RPL_LOLLIPOP_INIT;
 
 extern rpl_of_t RPL_OF;
@@ -182,6 +181,32 @@ set16(uint8_t *buffer, int pos, uint16_t value)
   buffer[pos++] = value & 0xff;
 }
 /*---------------------------------------------------------------------------*/
+uip_ds6_nbr_t *
+rpl_icmp6_update_nbr_table(uip_ipaddr_t *from)
+{
+  uip_ds6_nbr_t *nbr;
+
+  if((nbr = uip_ds6_nbr_lookup(from)) == NULL) {
+    if((nbr = uip_ds6_nbr_add(from, (uip_lladdr_t *)
+                              packetbuf_addr(PACKETBUF_ADDR_SENDER),
+                              0, NBR_REACHABLE)) != NULL) {
+      PRINTF("RPL: Neighbor added to neighbor cache ");
+      PRINT6ADDR(from);
+      PRINTF(", ");
+      PRINTLLADDR((uip_lladdr_t *)packetbuf_addr(PACKETBUF_ADDR_SENDER));
+      PRINTF("\n");
+    }
+  }
+
+  if(nbr != NULL) {
+#if UIP_ND6_SEND_NA
+    /* set reachable timer if we added or found the nbr entry */
+    stimer_set(&nbr->reachable, UIP_ND6_REACHABLE_TIME / 1000);
+#endif /* UIP_ND6_SEND_NA */
+  }
+  return nbr;
+ }
+/*---------------------------------------------------------------------------*/
 static void
 dis_input(void)
 {
@@ -205,11 +230,23 @@ dis_input(void)
         rpl_reset_dio_timer(instance);
       } else {
 #endif /* !RPL_LEAF_ONLY */
+	/* Check if this neighbor should be added according to the policy. */
+	if(RPL_NBR_POLICY.check_add_from_dis(&UIP_IP_BUF->srcipaddr)) {
+	  /* Add this to the neighbor cache if not already there */
+	  if(rpl_icmp6_update_nbr_table(&UIP_IP_BUF->srcipaddr) == NULL) {
+	    PRINTF("RPL: Out of Memory, not sending unicast DIO, DIS from ");
+	    PRINT6ADDR(&UIP_IP_BUF->srcipaddr);
+	    PRINTF(", ");
+	    PRINTLLADDR((uip_lladdr_t *)packetbuf_addr(PACKETBUF_ADDR_SENDER));
+	    PRINTF("\n");
+	    return;
+	  }
 	  PRINTF("RPL: Unicast DIS, reply to sender\n");
 	  dio_output(instance, &UIP_IP_BUF->srcipaddr);
 	}
       }
     }
+  }
   uip_clear_buf();
 }
 /*---------------------------------------------------------------------------*/
@@ -253,7 +290,6 @@ dio_input(void)
   int i;
   int len;
   uip_ipaddr_t from;
-  uip_ds6_nbr_t *nbr;
 
   memset(&dio, 0, sizeof(dio));
 
@@ -274,32 +310,6 @@ dio_input(void)
   PRINT6ADDR(&from);
   PRINTF("\n");
 
-  if((nbr = uip_ds6_nbr_lookup(&from)) == NULL) {
-    if((nbr = uip_ds6_nbr_add(&from, (uip_lladdr_t *)
-                              packetbuf_addr(PACKETBUF_ADDR_SENDER),
-                              0, NBR_REACHABLE)) != NULL) {
-#if UIP_ND6_SEND_NA
-      /* set reachable timer */
-      stimer_set(&nbr->reachable, UIP_ND6_REACHABLE_TIME / 1000);
-#endif /* UIP_ND6_SEND_NA */
-      PRINTF("RPL: Neighbor added to neighbor cache ");
-      PRINT6ADDR(&from);
-      PRINTF(", ");
-      PRINTLLADDR((uip_lladdr_t *)packetbuf_addr(PACKETBUF_ADDR_SENDER));
-      PRINTF("\n");
-    } else {
-      PRINTF("RPL: Out of memory, dropping DIO from ");
-      PRINT6ADDR(&from);
-      PRINTF(", ");
-      PRINTLLADDR((uip_lladdr_t *)packetbuf_addr(PACKETBUF_ADDR_SENDER));
-      PRINTF("\n");
-
-      goto discard;
-    }
-  } else {
-    PRINTF("RPL: Neighbor already in neighbor cache\n");
-  }
-
   buffer_length = uip_len - uip_l3_icmp_hdr_len;
 
   /* Process the DIO base option. */
@@ -796,20 +806,13 @@ dao_input(void)
 
   PRINTF("RPL: adding DAO route\n");
 
-  if((nbr = uip_ds6_nbr_lookup(&dao_sender_addr)) == NULL) {
+  /* Check if we should add another neighbor based on DAO. */
-    if((nbr = uip_ds6_nbr_add(&dao_sender_addr,
+  if(!RPL_NBR_POLICY.check_add_from_dao(&dao_sender_addr)) {
-                              (uip_lladdr_t *)packetbuf_addr(PACKETBUF_ADDR_SENDER),
+    /* Do not add the neighbor. */
-                              0, NBR_REACHABLE)) != NULL) {
+    return;
-#if UIP_ND6_SEND_NA
+  }
-      /* set reachable timer */
+  /* Update and add neighbor - if no room - fail. */
-      stimer_set(&nbr->reachable, UIP_ND6_REACHABLE_TIME / 1000);
+  if((nbr = rpl_icmp6_update_nbr_table(&dao_sender_addr)) == NULL) {
-#endif /* UIP_ND6_SEND_NA */
-      PRINTF("RPL: Neighbor added to neighbor cache ");
-      PRINT6ADDR(&dao_sender_addr);
-      PRINTF(", ");
-      PRINTLLADDR((uip_lladdr_t *)packetbuf_addr(PACKETBUF_ADDR_SENDER));
-      PRINTF("\n");
-    } else {
     PRINTF("RPL: Out of Memory, dropping DAO from ");
     PRINT6ADDR(&dao_sender_addr);
     PRINTF(", ");
@@ -817,9 +820,6 @@ dao_input(void)
     PRINTF("\n");
     goto discard;
   }
-  } else {
-    PRINTF("RPL: Neighbor already in neighbor cache\n");
-  }
 
   rep = rpl_add_route(dag, &prefix, prefixlen, &dao_sender_addr);
   if(rep == NULL) {
@@ -834,9 +834,8 @@ dao_input(void)
     goto discard;
   }
 
+  /* State is all zeroes, set lifetime but no need for other initialization. */
   rep->state.lifetime = RPL_LIFETIME(instance, lifetime);
-  /* rep->state.learned_from = learned_from; */
-  /* rep->state.nopath_received = 0; */
 
 #if RPL_CONF_MULTICAST
 fwd_dao:
@@ -877,8 +876,6 @@ fwd_dao:
                      ICMP6_RPL, RPL_CODE_DAO, buffer_length);
     }
 
-    /* Ack sent immediately after forwarding (otherwise the packets is
-       corrupted. */
     if(should_ack) {
       PRINTF("RPL: sending DAO ACK\n");
       dao_ack_output(instance, &dao_sender_addr, sequence,
@@ -897,30 +894,33 @@ handle_dao_retransmission(void *ptr)
   rpl_parent_t *parent;
   uip_ipaddr_t prefix;
   rpl_instance_t *instance;
-  parent = ptr;
 
+  parent = ptr;
   if(parent == NULL || parent->dag == NULL || parent->dag->instance == NULL) {
     return;
   }
   instance = parent->dag->instance;
 
   if(instance->my_dao_transmissions >= RPL_DAO_MAX_RETRANSMISSIONS) {
-    /* no more retransmissions - what now ??? */
+    /* No more retransmissions - give up. */
     if(instance->lifetime_unit == 0xffff && instance->default_lifetime == 0xff) {
-      /* RPL is using infinite lifetime for routes. This probably
+      /*
-	 means that the root is running an old version that does not
+       * ContikiRPL was previously using infinite lifetime for routes
-	 support DAO ack. Assume that everything is ok for now and
+       * and no DAO_ACK configured. This probably means that the root
-	 let the normal repair mechanisms detect any problems. */
+       * and possibly other nodes might be running an old version that
+       * does not support DAO ack. Assume that everything is ok for
+       * now and let the normal repair mechanisms detect any problems.
+       */
       return;
     }
 
     if(instance->of->dao_ack_callback) {
-      /* Inform about the timeout for taking decision on punishment */
+      /* Inform the objective function about the timeout. */
       instance->of->dao_ack_callback(parent, RPL_DAO_ACK_TIMEOUT);
     }
 
+    /* Perform local repair and hope to find another parent. */
     rpl_local_repair(instance);
-    /* give up this and hope to find another parent */
     return;
   }
 
@@ -1102,7 +1102,7 @@ dao_ack_input(void)
 #endif /* DEBUG */
 
   if(sequence == instance->my_dao_seqno) {
-    PRINTF("RPL: DAO ACK for me!\n");
+    PRINTF("RPL: DAO %s for me!\n", status < 128 ? "ACK" : "NACK");
 
     /* always stop the retransmit timer when the ACK arrived */
     ctimer_stop(&instance->dao_retransmit_timer);

core/net/rpl/rpl-nbr-policy.c

@@ -0,0 +1,244 @@
+/*
+ * Copyright (c) 2014-2015, Yanzi Networks AB.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *    1. Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *    2. Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *    3. Neither the name of the copyright holders nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ */
+/**
+ * \addtogroup uip6
+ * @{
+ */
+
+
+/**
+ * \file
+ *
+ * Default RPL NBR policy
+ * decides when to add a new discovered node to the nbr table from RPL.
+ *
+ * \author Joakim Eriksson <joakime@sics.se>
+ * Contributors: Niclas Finne <nfi@sics.se>, Oriol Piñol <oriol@yanzi.se>,
+ *
+ */
+
+#include "net/rpl/rpl-private.h"
+#include "net/nbr-table.h"
+#include "net/ipv6/uip-ds6-nbr.h"
+#include "net/ipv6/uip-ds6-route.h"
+
+#define DEBUG DEBUG_NONE
+#include "net/ip/uip-debug.h"
+
+/*
+ * Policy for neighbor adds
+ * - one node is locked (default route)
+ * - max X children (nexthops)
+ * - max Y "best parents"
+ * => at least MAX_NBRS - (Y + X + 1) free slots for other.
+ */
+
+#define MAX_CHILDREN (NBR_TABLE_MAX_NEIGHBORS - 3)
+
+static int num_parents; /* any node that are possible parents */
+static int num_children;  /* all children that we have as nexthop */
+static int num_free;
+static uip_ds6_nbr_t *worst_rank_nbr; /* the parent that has the worst rank */
+static rpl_rank_t worst_rank;
+/*---------------------------------------------------------------------------*/
+static void
+update_nbr(void)
+{
+  uip_ds6_nbr_t *nbr;
+  rpl_parent_t *parent;
+  int num_used;
+  int is_used;
+  rpl_rank_t rank;
+
+  worst_rank = 0;
+  worst_rank_nbr = NULL;
+  num_used = 0;
+  num_parents = 0;
+  num_children = 0;
+
+  nbr = nbr_table_head(ds6_neighbors);
+  while(nbr != NULL) {
+    linkaddr_t *lladdr = nbr_table_get_lladdr(ds6_neighbors, nbr);
+    is_used = 0;
+
+    parent = rpl_get_parent((uip_lladdr_t *)lladdr);
+    if(parent != NULL) {
+      num_parents++;
+      is_used++;
+
+      if(parent->dag != NULL && parent->dag->preferred_parent == parent) {
+        /* This is the preferred parent for the DAG and must not be removed */
+
+        /* Note: this assumes that only RPL adds default routes. */
+
+      } else if(worst_rank < INFINITE_RANK &&
+                parent->rank > 0 &&
+                parent->dag != NULL &&
+                parent->dag->instance != NULL &&
+                (rank = parent->dag->instance->of->calculate_rank(parent, 0)) > worst_rank) {
+        /* This is the worst-rank neighbor - this is a good candidate for removal */
+        worst_rank = rank;
+        worst_rank_nbr = nbr;
+      }
+    }
+
+    /* Check if this neighbor is used as nexthop and therefor being a
+       RPL child. */
+    if(uip_ds6_route_is_nexthop((uip_lladdr_t *)lladdr) != 0) {
+      is_used++;
+      num_children++;
+    }
+
+    if(is_used == 0) {
+      /* This neighbor is neither parent or child and can be safely removed */
+      worst_rank_nbr = nbr;
+      worst_rank = INFINITE_RANK;
+    } else if(is_used > 1) {
+      /* Both parent and child - this should never happen! */
+      PRINTF("NBR-POLICY: *** Neighbor is both child and candidate parent: ");
+      PRINTLLADDR((uip_lladdr_t *)lladdr);
+      PRINTF("\n");
+    }
+
+    nbr = nbr_table_next(ds6_neighbors, nbr);
+    num_used++;
+  }
+  /* how many more IP neighbors can be have? */
+  num_free = NBR_TABLE_MAX_NEIGHBORS - num_used;
+
+  PRINTF("NBR-POLICY: Free: %d, Children: %d, Parents: %d Routes: %d\n",
+	 num_free, num_children, num_parents, uip_ds6_route_num_routes());
+}
+/*---------------------------------------------------------------------------*/
+static int
+remove_worst_nbr(void)
+{
+  /* we assume that it is possible to remove the worst parent at the moment */
+  if(worst_rank_nbr != NULL) {
+    PRINTF("Removing worst ranked nbr ");
+    PRINTLLADDR((uip_lladdr_t*)nbr_table_get_lladdr(ds6_neighbors, worst_rank_nbr));
+    PRINTF(" with rank %d\n", worst_rank);
+    if(uip_ds6_nbr_rm(worst_rank_nbr)) {
+      worst_rank_nbr = NULL;
+      return 1;
+    }
+    PRINTF("FAILED to remove worst ranked nbr!\n");
+    return 0;
+  }
+  PRINTF("FAILED to remove worst rank nbr - no found\n");
+  return 0;
+}
+/*---------------------------------------------------------------------------*/
+/* Called whenever we get a unicast DIS - e.g. someone that already
+   have this node in its table - since it is a unicast */
+static int
+check_add_from_dis(uip_ipaddr_t *from)
+{
+
+  /* do a lookup to see if it is alread there - then allow add/update */
+  if(uip_ds6_nbr_lookup(from)) {
+    return 1;
+  }
+  update_nbr();
+  if(num_free > 0) {
+    return 1;
+  }
+  if(num_children < MAX_CHILDREN) {
+    return remove_worst_nbr();
+  }
+  return 0;
+}
+/*---------------------------------------------------------------------------*/
+static int
+check_add_from_dio(uip_ipaddr_t *from, rpl_dio_t *dio)
+{
+  rpl_instance_t *instance;
+  rpl_rank_t rank;
+
+  /* Do a lookup to see if it is already there - then allow add/update. */
+  if(uip_ds6_nbr_lookup(from)) {
+    return 1;
+  }
+
+  update_nbr();
+
+  /* If there is room for this neighbor just add it. */
+  if(num_free > 0) {
+    return 1;
+  }
+
+  instance = rpl_get_instance(dio->instance_id);
+  if(instance == NULL || instance->current_dag == NULL) {
+    PRINTF("Did not find instance id: %d\n", dio->instance_id);
+    return 0;
+  }
+
+  /* Add the new neighbor only if it is better than the preferred parent. */
+  rank = instance->of->calculate_rank(NULL, dio->rank);
+  if(rank < worst_rank - instance->min_hoprankinc / 2) {
+    /* Found *great* neighbor - add! */
+    PRINTF("Found better neighbor %d < %d - add to cache...\n",
+           rank, worst_rank);
+
+    return remove_worst_nbr();
+  }
+
+  PRINTF("Found worse neighbor with new %d and old %d - NOT add to cache.\n",
+         rank, worst_rank);
+  return 0;
+}
+/*---------------------------------------------------------------------------*/
+static int
+check_add_from_dao(uip_ipaddr_t *from)
+{
+  /* Do a lookup to see if it is alread there - then allow add/update. */
+  if(uip_ds6_nbr_lookup(from)) {
+    return 1;
+  }
+
+  update_nbr();
+
+  /* Check if this DAO sender is not yet neighbor and there is already too
+     many children. */
+  if(num_children >= MAX_CHILDREN) {
+    PRINTF("Can not add another child - already at max.\n");
+    return 0;
+  }
+
+  return 1;
+}
+/*---------------------------------------------------------------------------*/
+const struct nbr_policy rpl_nbr_policy = {
+  check_add_from_dis,
+  check_add_from_dio,
+  check_add_from_dao
+};
+/*---------------------------------------------------------------------------*/
+/** @}*/

core/net/rpl/rpl-private.h

@@ -124,8 +124,17 @@
 #define RPL_NOPATH_REMOVAL_DELAY          60
 #endif /* RPL_CONF_NOPATH_REMOVAL_DELAY */
 
+#ifdef RPL_CONF_DAO_MAX_RETRANSMISSIONS
+#define RPL_DAO_MAX_RETRANSMISSIONS RPL_CONF_DAO_MAX_RETRANSMISSIONS
+#else
 #define RPL_DAO_MAX_RETRANSMISSIONS     5
+#endif /* RPL_CONF_DAO_MAX_RETRANSMISSIONS */
+
+#ifdef RPL_CONF_DAO_RETRANSMISSION_TIMEOUT
+#define RPL_DAO_RETRANSMISSION_TIMEOUT RPL_CONF_DAO_RETRANSMISSION_TIMEOUT
+#else
 #define RPL_DAO_RETRANSMISSION_TIMEOUT  (5 * CLOCK_SECOND)
+#endif /* RPL_CONF_DAO_RETRANSMISSION_TIMEOUT */
 
 /* Special value indicating immediate removal. */
 #define RPL_ZERO_LIFETIME               0
@@ -260,6 +269,24 @@ typedef struct rpl_stats rpl_stats_t;
 
 extern rpl_stats_t rpl_stats;
 #endif
+
+struct nbr_policy {
+  /** check if it is ok to add a nbr via UC DIS - positive => ok */
+  int (* check_add_from_dis)(uip_ipaddr_t *from);
+  int (* check_add_from_dio)(uip_ipaddr_t *from, rpl_dio_t *dio);
+  int (* check_add_from_dao)(uip_ipaddr_t *from);
+};
+
+
+#ifdef RPL_CONF_NBR_POLICY
+#define RPL_NBR_POLICY RPL_CONF_NBR_POLICY
+#else /* RPL_CONF_NBR_POLICY */
+#define RPL_NBR_POLICY rpl_nbr_policy
+#endif /* RPL_CONF_NBR_POLICY */
+
+extern const struct nbr_policy RPL_NBR_POLICY;
+
+
 /*---------------------------------------------------------------------------*/
 /* RPL macros. */
 
@@ -280,6 +307,7 @@ void dao_output(rpl_parent_t *, uint8_t lifetime);
 void dao_output_target(rpl_parent_t *, uip_ipaddr_t *, uint8_t lifetime);
 void dao_ack_output(rpl_instance_t *, uip_ipaddr_t *, uint8_t, uint8_t);
 void rpl_icmp6_register_handlers(void);
+uip_ds6_nbr_t *rpl_icmp6_update_nbr_table(uip_ipaddr_t *from);
 
 /* RPL logic functions. */
 void rpl_join_dag(uip_ipaddr_t *from, rpl_dio_t *dio);

core/net/rpl/rpl.c

@@ -238,7 +238,6 @@ rpl_add_route(rpl_dag_t *dag, uip_ipaddr_t *prefix, int prefix_len,
 
   rep->state.dag = dag;
   rep->state.lifetime = RPL_LIFETIME(dag->instance, dag->instance->default_lifetime);
-  /* rep->state.learned_from = RPL_ROUTE_FROM_INTERNAL; */
 
   PRINTF("RPL: Added a route to ");
   PRINT6ADDR(prefix);