From 8f76c824336b8b1c635e53234a071ebf124d2c03 Mon Sep 17 00:00:00 2001
From: nvt-se <nvt-se>
Date: Fri, 17 Dec 2010 15:24:25 +0000
Subject: [PATCH] Improved DAO management.

---
 core/net/rpl/rpl-dag.c    |  8 +++++---
 core/net/rpl/rpl-icmp6.c  |  5 +++--
 core/net/rpl/rpl-timers.c | 11 ++++++-----
 core/net/rpl/rpl.h        |  5 +++--
 4 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/core/net/rpl/rpl-dag.c b/core/net/rpl/rpl-dag.c
index 25bf8273a..84c1dabee 100644
--- a/core/net/rpl/rpl-dag.c
+++ b/core/net/rpl/rpl-dag.c
@@ -32,7 +32,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * $Id: rpl-dag.c,v 1.41 2010/12/13 10:59:37 joxe Exp $
+ * $Id: rpl-dag.c,v 1.42 2010/12/17 15:24:25 nvt-se Exp $
  */
 /**
  * \file
@@ -117,8 +117,7 @@ remove_parents(rpl_dag_t *dag, rpl_rank_t minimum_rank)
 static int
 should_send_dao(rpl_dag_t *dag, rpl_dio_t *dio, rpl_parent_t *p)
 {
-  return 1;
-/*  return dio->dtsn > p->dtsn && p == dag->preferred_parent;*/
+  return dio->dtsn > p->dtsn && p == dag->preferred_parent;
 }
 /************************************************************************/
 static int
@@ -237,6 +236,8 @@ rpl_alloc_dag(uint8_t instance_id)
       return dag;
     }
   }
+
+  RPL_STAT(rpl_stats.mem_overflows++);
   return NULL;
 }
 /************************************************************************/
@@ -372,6 +373,7 @@ rpl_dag_t *
 rpl_get_dag(int instance_id)
 {
   int i;
+
   for(i = 0; i < RPL_MAX_DAG_ENTRIES; i++) {
     if(dag_table[i].joined && (instance_id == RPL_ANY_INSTANCE ||
                                dag_table[i].instance_id == instance_id)) {
diff --git a/core/net/rpl/rpl-icmp6.c b/core/net/rpl/rpl-icmp6.c
index 801441173..ea3ea5db4 100644
--- a/core/net/rpl/rpl-icmp6.c
+++ b/core/net/rpl/rpl-icmp6.c
@@ -32,7 +32,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * $Id: rpl-icmp6.c,v 1.33 2010/12/15 19:57:40 nvt-se Exp $
+ * $Id: rpl-icmp6.c,v 1.34 2010/12/17 15:24:25 nvt-se Exp $
  */
 /**
  * \file
@@ -484,7 +484,7 @@ dao_input(void)
   PRINTF("\n");
 
   if(lifetime == ZERO_LIFETIME) {
-    /* No-DAO received; invoke the route purging routine. */
+    /* No-Path DAO received; invoke the route purging routine. */
     rep = uip_ds6_route_lookup(&prefix);
     if(rep != NULL && rep->state.saved_lifetime == 0) {
       PRINTF("RPL: Setting expiration timer for prefix ");
@@ -515,6 +515,7 @@ dao_input(void)
 
   rep = rpl_add_route(dag, &prefix, prefixlen, &dao_sender_addr);
   if(rep == NULL) {
+    RPL_STAT(rpl_stats.memory_overflows++);
     PRINTF("RPL: Could not add a route after receiving a DAO\n");
     return;
   } else {
diff --git a/core/net/rpl/rpl-timers.c b/core/net/rpl/rpl-timers.c
index b2303ad48..9bf2cb330 100644
--- a/core/net/rpl/rpl-timers.c
+++ b/core/net/rpl/rpl-timers.c
@@ -32,7 +32,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * $Id: rpl-timers.c,v 1.15 2010/12/15 12:12:27 nvt-se Exp $
+ * $Id: rpl-timers.c,v 1.16 2010/12/17 15:24:25 nvt-se Exp $
  */
 /**
  * \file
@@ -224,10 +224,11 @@ rpl_schedule_dao(rpl_dag_t *dag)
   if(!etimer_expired(&dag->dao_timer.etimer)) {
     PRINTF("RPL: DAO timer already scheduled\n");
   } else {
-    PRINTF("RPL: Scheduling DAO timer %u ticks in the future (%u %u)\n",
-           (unsigned)DEFAULT_DAO_LATENCY / dag->rank,
-           (unsigned)DEFAULT_DAO_LATENCY, (unsigned)dag->rank);
-    ctimer_set(&dag->dao_timer, DEFAULT_DAO_LATENCY,
+    expiration_time = DEFAULT_DAO_LATENCY / 2 +
+      (random_rand() % (DEFAULT_DAO_LATENCY));
+    PRINTF("RPL: Scheduling DAO timer %u ticks in the future\n",
+           (unsigned)expiration_time);
+    ctimer_set(&dag->dao_timer, expiration_time,
                handle_dao_timer, dag);
   }
 }
diff --git a/core/net/rpl/rpl.h b/core/net/rpl/rpl.h
index b857fd910..a1e190cda 100644
--- a/core/net/rpl/rpl.h
+++ b/core/net/rpl/rpl.h
@@ -30,7 +30,7 @@
  *
  * Author: Joakim Eriksson, Nicolas Tsiftes
  *
- * $Id: rpl.h,v 1.27 2010/12/15 13:37:34 nvt-se Exp $
+ * $Id: rpl.h,v 1.28 2010/12/17 15:24:25 nvt-se Exp $
  */
 
 #ifndef RPL_H
@@ -85,7 +85,8 @@
 /*---------------------------------------------------------------------------*/
 /* Default values for RPL constants and variables. */
 
-#define DEFAULT_DAO_LATENCY             (CLOCK_SECOND * (1 + (random_rand() & 0xf)))
+/* The default value for the DAO timer. */
+#define DEFAULT_DAO_LATENCY             (CLOCK_SECOND * 8)
 
 /* Special value indicating immediate removal. */
 #define ZERO_LIFETIME                   0