RPL parent select update:

Added Unicast DIO trigger if not received configured time

RPL policy support to config fixed point for missing IMax period 1.0 fixed point is 0x0100

Change-Id: I15105ee82e72358ef981d2799e029ecd867ec337

Author: Juha Heiskanen

source/RPL/rpl_policy.c

@@ -37,6 +37,7 @@
 static bool rpl_policy_parent_confirmation_req = false;
 static int8_t rpl_policy_dao_retry_count_conf = 0;
 static int16_t rpl_policy_dao_initial_timeout_conf = 20; // Default is 2 seconds 100ms ticks
+static uint16_t rpl_policy_dio_validity_period_hysteresis = 0x0180; //Fixed Point 1.5
 
 /* TODO - application API to control when to join new instances / DODAGs
  *
@@ -210,6 +211,20 @@ uint16_t rpl_policy_etx_hysteresis(rpl_domain_t *domain)
     return 0x0080; /* 8.8 fixed-point, so 0.5 */
 }
 
+uint16_t rpl_policy_dio_validity_period(rpl_domain_t *domain)
+{
+    (void)domain;
+
+    return rpl_policy_dio_validity_period_hysteresis; /* Fixed Point */
+}
+
+void rpl_policy_set_dio_validity_period(rpl_domain_t *domain, uint16_t fixed_point)
+{
+    (void)domain;
+
+    rpl_policy_dio_validity_period_hysteresis = fixed_point; /* Fixed Point */
+}
+
 uint16_t rpl_policy_etx_change_parent_selection_delay(rpl_domain_t *domain)
 {
     (void)domain;

source/RPL/rpl_policy.h

@@ -37,6 +37,10 @@ uint16_t rpl_policy_modify_downward_cost_to_root_neighbour(rpl_domain_t *domain,
 
 uint16_t rpl_policy_parent_selection_period(rpl_domain_t *domain);
 uint16_t rpl_policy_etx_hysteresis(rpl_domain_t *domain);
+//Return Fixed point multiple which base 1.0 is 0x0100
+uint16_t rpl_policy_dio_validity_period(rpl_domain_t *domain);
+//Fixed point must 1.0 is 0x0100
+void rpl_policy_set_dio_validity_period(rpl_domain_t *domain, uint16_t fixed_point);
 uint16_t rpl_policy_etx_change_parent_selection_delay(rpl_domain_t *domain);
 uint16_t rpl_policy_dio_parent_selection_delay(rpl_domain_t *domain);
 

source/RPL/rpl_upward.c

@@ -1355,6 +1355,11 @@ static void trace_info_print(const char *fmt, ...)
     va_end(ap);
 }
 
+static uint32_t rpl_dio_imax_time_calculate(uint16_t Imax, uint16_t fixed_point)
+{
+    return (((uint32_t)Imax * fixed_point) / 0x0100);
+}
+
 
 void rpl_instance_run_parent_selection(rpl_instance_t *instance)
 {
@@ -1438,6 +1443,15 @@ void rpl_instance_run_parent_selection(rpl_instance_t *instance)
     if (preferred_parent) {
         // Always stop repair if we find a parent
         rpl_instance_set_local_repair(instance, false);
+        //Validate time from last DIO
+
+        uint32_t time_between_parent = protocol_core_monotonic_time - preferred_parent->dio_timestamp;
+        uint32_t accepted_time = rpl_dio_imax_time_calculate(instance->current_dodag_version->dodag->dio_timer_params.Imax, rpl_policy_dio_validity_period(instance->domain));
+
+        if (accepted_time < time_between_parent) {
+            rpl_control_transmit_dis(instance->domain, NULL, RPL_SOLINFO_PRED_INSTANCEID, instance->id, NULL, 0, preferred_parent->ll_address);
+        }
+
     } else if (original_preferred) {
         // Only start repair if we just lost a parent
         rpl_instance_set_local_repair(instance, true);
@@ -1921,7 +1935,7 @@ bool rpl_upward_accept_prefix_update(const rpl_dodag_t *dodag_info, const rpl_ne
         //Calculate Time between from last dio from parent and this neighbour
         //neighbour dio_timestamp >= pref_parent's, because it's a newly-received message
         uint32_t time_between_parent = neighbour->dio_timestamp - pref_parent->dio_timestamp;
-        uint32_t accepted_time = (uint32_t)dodag_info->dio_timer_params.Imax * 2;
+        uint32_t accepted_time = rpl_dio_imax_time_calculate(dodag_info->dio_timer_params.Imax, 0x0200);
         //Accept prefix Update If Time from last DIO is more than 2 x Max
         if (accepted_time < time_between_parent) {
             return true;

test/nanostack/unittest/stub/rpl_policy_stub.c

@@ -83,6 +83,16 @@ uint16_t rpl_policy_etx_hysteresis(rpl_domain_t *domain)
     return 0;
 }
 
+uint16_t rpl_policy_dio_validity_period(rpl_domain_t *domain)
+{
+    return 0x0180;
+}
+
+void rpl_policy_set_dio_validity_period(rpl_domain_t *domain, uint16_t fixed_point)
+{
+
+}
+
 uint16_t rpl_policy_etx_change_parent_selection_delay(rpl_domain_t *domain)
 {
     return 0;