From 832a4d3e01349458a48a585e2e1af72ec6be0411 Mon Sep 17 00:00:00 2001
From: Simon Duquennoy <simonduq@sics.se>
Date: Sun, 10 May 2015 13:19:56 +0200
Subject: [PATCH] Make probing expiration time configurable

---
 core/net/rpl/rpl-conf.h   |  9 +++++++++
 core/net/rpl/rpl-timers.c | 11 ++++++-----
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/core/net/rpl/rpl-conf.h b/core/net/rpl/rpl-conf.h
index 11d2cdbd0..a2c0e6dd2 100644
--- a/core/net/rpl/rpl-conf.h
+++ b/core/net/rpl/rpl-conf.h
@@ -226,6 +226,15 @@
 #define RPL_PROBING_INTERVAL (120 * CLOCK_SECOND)
 #endif
 
+/*
+ * RPL probing expiration time.
+ * */
+#ifdef RPL_CONF_PROBING_EXPIRATION_TIME
+#define RPL_PROBING_EXPIRATION_TIME RPL_CONF_PROBING_EXPIRATION_TIME
+#else
+#define RPL_PROBING_EXPIRATION_TIME (10 * 60 * CLOCK_SECOND)
+#endif
+
 /*
  * Function used to select the next parent to be probed.
  * */
diff --git a/core/net/rpl/rpl-timers.c b/core/net/rpl/rpl-timers.c
index fac19ee4f..def1ff404 100644
--- a/core/net/rpl/rpl-timers.c
+++ b/core/net/rpl/rpl-timers.c
@@ -332,18 +332,19 @@ static rpl_parent_t *
 get_probing_target(rpl_dag_t *dag)
 {
   /* Returns the next probing target. The current implementation probes the current
-   * preferred parent if we have not updated its link for 2 * RPL_PROBING_INTERVAL.
+   * preferred parent if we have not updated its link for RPL_PROBING_EXPIRATION_TIME.
    * Otherwise, it picks at random between:
-   * (1) selecting the best parent not updated for 2 * RPL_PROBING_INTERVAL
+   * (1) selecting the best parent not updated for RPL_PROBING_EXPIRATION_TIME
    * (2) selecting the least recently updated parent
    */
 
   rpl_parent_t *p;
   rpl_parent_t *probing_target = NULL;
   rpl_rank_t probing_target_rank = INFINITE_RANK;
-  /* min_last_tx is the clock time (2 * RPL_PROBING_INTERVAL) in the past */
+  /* min_last_tx is the clock time RPL_PROBING_EXPIRATION_TIME in the past */
   clock_time_t min_last_tx = clock_time();
-  min_last_tx = min_last_tx > 2 * RPL_PROBING_INTERVAL ? min_last_tx - 2 * RPL_PROBING_INTERVAL : 1;
+  min_last_tx = min_last_tx > 2 * RPL_PROBING_EXPIRATION_TIME
+      ? min_last_tx - RPL_PROBING_EXPIRATION_TIME : 1;
 
   if(dag == NULL ||
       dag->instance == NULL ||
@@ -357,7 +358,7 @@ get_probing_target(rpl_dag_t *dag)
   }
 
   if((random_rand() % 2) == 0) {
-    /* With 1/2 probability: probe best parent not updated for 2 * RPL_PROBING_INTERVAL */
+    /* With 1/2 probability: probe best parent not updated for RPL_PROBING_EXPIRATION_TIME */
     p = nbr_table_head(rpl_parents);
     while(p != NULL) {
       if(p->dag == dag && p->last_tx_time < min_last_tx) {