From b782cda83760ab1a630b69b2aa3d5af521469cfe Mon Sep 17 00:00:00 2001
From: Laurent Deru <laurent.deru@cetic.be>
Date: Mon, 11 Dec 2017 17:19:51 +0100
Subject: [PATCH] Do RPL probing on all the known DAG

---
 os/net/rpl-classic/rpl-ns.h     |  1 +
 os/net/rpl-classic/rpl-timers.c | 20 +++++++++++++++++++-
 os/net/rpl-classic/rpl.h        |  1 +
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/os/net/rpl-classic/rpl-ns.h b/os/net/rpl-classic/rpl-ns.h
index f6ae4c2c6..dcc7e584a 100644
--- a/os/net/rpl-classic/rpl-ns.h
+++ b/os/net/rpl-classic/rpl-ns.h
@@ -56,6 +56,7 @@
 typedef struct rpl_ns_node {
   struct rpl_ns_node *next;
   uint32_t lifetime;
+  rpl_dag_t *dag;
   /* Store only IPv6 link identifiers as all nodes in the DAG share the same prefix */
   unsigned char link_identifier[8];
   struct rpl_ns_node *parent;
diff --git a/os/net/rpl-classic/rpl-timers.c b/os/net/rpl-classic/rpl-timers.c
index b89a1258d..9d3db3d22 100644
--- a/os/net/rpl-classic/rpl-timers.c
+++ b/os/net/rpl-classic/rpl-timers.c
@@ -457,11 +457,29 @@ get_probing_target(rpl_dag_t *dag)
   return probing_target;
 }
 /*---------------------------------------------------------------------------*/
+static rpl_dag_t *
+get_next_dag(rpl_instance_t *instance)
+{
+  rpl_dag_t *dag = NULL;
+  int new_dag = instance->last_dag;
+  do {
+    new_dag++;
+    if(new_dag >= RPL_MAX_DAG_PER_INSTANCE) {
+      new_dag = 0;
+    }
+    if(instance->dag_table[new_dag].used) {
+      dag = &instance->dag_table[new_dag];
+    }
+  } while(new_dag != instance->last_dag && dag == NULL);
+  instance->last_dag = new_dag;
+  return dag;
+}
+/*---------------------------------------------------------------------------*/
 static void
 handle_probing_timer(void *ptr)
 {
   rpl_instance_t *instance = (rpl_instance_t *)ptr;
-  rpl_parent_t *probing_target = RPL_PROBING_SELECT_FUNC(instance->current_dag);
+  rpl_parent_t *probing_target = RPL_PROBING_SELECT_FUNC(get_next_dag(instance));
   uip_ipaddr_t *target_ipaddr = rpl_parent_get_ipaddr(probing_target);
 
   /* Perform probing */
diff --git a/os/net/rpl-classic/rpl.h b/os/net/rpl-classic/rpl.h
index 185bcbef2..2fe9f1dbf 100644
--- a/os/net/rpl-classic/rpl.h
+++ b/os/net/rpl-classic/rpl.h
@@ -252,6 +252,7 @@ struct rpl_instance {
 #if RPL_WITH_PROBING
   struct ctimer probing_timer;
   rpl_parent_t *urgent_probing_target;
+  int last_dag;
 #endif /* RPL_WITH_PROBING */
   struct ctimer dio_timer;
   struct ctimer dao_timer;