nes-proj/os/net/rpl-lite/rpl-timers.c

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/*
* Copyright (c) 2010, Swedish Institute of Computer Science.
* 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 Institute 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 INSTITUTE 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 INSTITUTE OR CONTRIBUTORS 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.
*
* This file is part of the Contiki operating system.
*/
/**
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* \addtogroup rpl-lite
* @{
*
* \file
* RPL timer management.
*
* \author Joakim Eriksson <joakime@sics.se>, Nicolas Tsiftes <nvt@sics.se>,
* Simon Duquennoy <simon.duquennoy@inria.fr>
*/
#include "contiki.h"
#include "net/rpl-lite/rpl.h"
#include "net/link-stats.h"
#include "lib/random.h"
#include "sys/ctimer.h"
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/* Log configuration */
#include "sys/log.h"
#define LOG_MODULE "RPL"
#define LOG_LEVEL LOG_LEVEL_RPL
/* A configurable function called after update of the RPL DIO interval */
#ifdef RPL_CALLBACK_NEW_DIO_INTERVAL
void RPL_CALLBACK_NEW_DIO_INTERVAL(clock_time_t dio_interval);
#endif /* RPL_CALLBACK_NEW_DIO_INTERVAL */
#ifdef RPL_PROBING_SELECT_FUNC
rpl_nbr_t *RPL_PROBING_SELECT_FUNC(void);
#endif /* RPL_PROBING_SELECT_FUNC */
#ifdef RPL_PROBING_DELAY_FUNC
clock_time_t RPL_PROBING_DELAY_FUNC(void);
#endif /* RPL_PROBING_DELAY_FUNC */
#define PERIODIC_DELAY_SECONDS 60
#define PERIODIC_DELAY ((PERIODIC_DELAY_SECONDS) * CLOCK_SECOND)
static void handle_dis_timer(void *ptr);
static void handle_dio_timer(void *ptr);
static void handle_unicast_dio_timer(void *ptr);
static void handle_dao_timer(void *ptr);
#if RPL_WITH_DAO_ACK
static void handle_dao_ack_timer(void *ptr);
#endif /* RPL_WITH_DAO_ACK */
#if RPL_WITH_PROBING
static void handle_probing_timer(void *ptr);
#endif /* RPL_WITH_PROBING */
static void handle_periodic_timer(void *ptr);
static void handle_state_update(void *ptr);
/*---------------------------------------------------------------------------*/
static struct ctimer dis_timer; /* Not part of a DAG because when not joined */
static struct ctimer periodic_timer; /* Not part of a DAG because used for general state maintenance */
/*---------------------------------------------------------------------------*/
/*------------------------------- DIS -------------------------------------- */
/*---------------------------------------------------------------------------*/
void
rpl_timers_schedule_periodic_dis(void)
{
if(ctimer_expired(&dis_timer)) {
clock_time_t expiration_time = RPL_DIS_INTERVAL / 2 + (random_rand() % (RPL_DIS_INTERVAL));
ctimer_set(&dis_timer, expiration_time, handle_dis_timer, NULL);
}
}
/*---------------------------------------------------------------------------*/
static void
handle_dis_timer(void *ptr)
{
if(!rpl_dag_root_is_root() &&
(!curr_instance.used ||
curr_instance.dag.preferred_parent == NULL ||
curr_instance.dag.rank == RPL_INFINITE_RANK)) {
/* Send DIS and schedule next */
rpl_icmp6_dis_output(NULL);
rpl_timers_schedule_periodic_dis();
}
}
/*---------------------------------------------------------------------------*/
/*------------------------------- DIO -------------------------------------- */
/*---------------------------------------------------------------------------*/
static void
new_dio_interval(void)
{
uint32_t time;
clock_time_t ticks;
time = 1UL << curr_instance.dag.dio_intcurrent;
/* Convert from milliseconds to CLOCK_TICKS. */
ticks = (time * CLOCK_SECOND) / 1000;
curr_instance.dag.dio_next_delay = ticks;
/* random number between I/2 and I */
ticks = ticks / 2 + (ticks / 2 * (uint32_t)random_rand()) / RANDOM_RAND_MAX;
/*
* The intervals must be equally long among the nodes for Trickle to
* operate efficiently. Therefore we need to calculate the delay between
* the randomized time and the start time of the next interval.
*/
curr_instance.dag.dio_next_delay -= ticks;
curr_instance.dag.dio_send = 1;
/* reset the redundancy counter */
curr_instance.dag.dio_counter = 0;
/* schedule the timer */
ctimer_set(&curr_instance.dag.dio_timer, ticks, &handle_dio_timer, NULL);
#ifdef RPL_CALLBACK_NEW_DIO_INTERVAL
RPL_CALLBACK_NEW_DIO_INTERVAL((CLOCK_SECOND * 1UL << curr_instance.dag.dio_intcurrent) / 1000);
#endif /* RPL_CALLBACK_NEW_DIO_INTERVAL */
}
/*---------------------------------------------------------------------------*/
void
rpl_timers_dio_reset(const char *str)
{
if(rpl_dag_ready_to_advertise()) {
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LOG_INFO("reset DIO timer (%s)\n", str);
#if !RPL_LEAF_ONLY
curr_instance.dag.dio_counter = 0;
curr_instance.dag.dio_intcurrent = curr_instance.dio_intmin;
new_dio_interval();
#endif /* RPL_LEAF_ONLY */
}
}
/*---------------------------------------------------------------------------*/
static void
handle_dio_timer(void *ptr)
{
if(!rpl_dag_ready_to_advertise()) {
return; /* We will be scheduled again later */
}
if(curr_instance.dag.dio_send) {
/* send DIO if counter is less than desired redundancy, or if dio_redundancy
is set to 0, or if we are the root */
if(rpl_dag_root_is_root() || curr_instance.dio_redundancy == 0 ||
curr_instance.dag.dio_counter < curr_instance.dio_redundancy) {
#if RPL_TRICKLE_REFRESH_DAO_ROUTES
if(rpl_dag_root_is_root()) {
static int count = 0;
if((count++ % RPL_TRICKLE_REFRESH_DAO_ROUTES) == 0) {
/* Request new DAO to refresh route. */
RPL_LOLLIPOP_INCREMENT(curr_instance.dtsn_out);
LOG_INFO("trigger DAO updates with a DTSN increment (%u)\n", curr_instance.dtsn_out);
}
}
#endif /* RPL_TRICKLE_REFRESH_DAO_ROUTES */
curr_instance.dag.last_advertised_rank = curr_instance.dag.rank;
rpl_icmp6_dio_output(NULL);
}
curr_instance.dag.dio_send = 0;
ctimer_set(&curr_instance.dag.dio_timer, curr_instance.dag.dio_next_delay, handle_dio_timer, NULL);
} else {
/* check if we need to double interval */
if(curr_instance.dag.dio_intcurrent < curr_instance.dio_intmin + curr_instance.dio_intdoubl) {
curr_instance.dag.dio_intcurrent++;
}
new_dio_interval();
}
}
/*---------------------------------------------------------------------------*/
/*------------------------------- Unicast DIO ------------------------------ */
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
void
rpl_timers_schedule_unicast_dio(rpl_nbr_t *target)
{
if(curr_instance.used) {
curr_instance.dag.unicast_dio_target = target;
ctimer_set(&curr_instance.dag.unicast_dio_timer, 0,
handle_unicast_dio_timer, NULL);
}
}
/*---------------------------------------------------------------------------*/
static void
handle_unicast_dio_timer(void *ptr)
{
uip_ipaddr_t *target_ipaddr = rpl_neighbor_get_ipaddr(curr_instance.dag.unicast_dio_target);
if(target_ipaddr != NULL) {
rpl_icmp6_dio_output(target_ipaddr);
}
}
/*---------------------------------------------------------------------------*/
/*------------------------------- DAO -------------------------------------- */
/*---------------------------------------------------------------------------*/
#if RPL_WITH_DAO_ACK
/*---------------------------------------------------------------------------*/
static void
schedule_dao_retransmission(void)
{
clock_time_t expiration_time = RPL_DAO_RETRANSMISSION_TIMEOUT / 2 + (random_rand() % (RPL_DAO_RETRANSMISSION_TIMEOUT));
ctimer_set(&curr_instance.dag.dao_timer, expiration_time, handle_dao_timer, NULL);
}
#endif /* RPL_WITH_DAO_ACK */
/*---------------------------------------------------------------------------*/
static void
schedule_dao_refresh(void)
{
if(curr_instance.used && curr_instance.default_lifetime != RPL_INFINITE_LIFETIME) {
#if RPL_WITH_DAO_ACK
/* DAO-ACK enabled: the last DAO was ACKed, wait until expiration before refresh */
clock_time_t target_refresh = CLOCK_SECOND * RPL_LIFETIME(curr_instance.default_lifetime);
#else /* RPL_WITH_DAO_ACK */
/* DAO-ACK disabled: use half the expiration time to get two chances to refresh per lifetime */
clock_time_t target_refresh = (CLOCK_SECOND * RPL_LIFETIME(curr_instance.default_lifetime) / 2);
#endif /* RPL_WITH_DAO_ACK */
/* Send between 60 and 120 seconds before target refresh */
clock_time_t safety_margin = (60 * CLOCK_SECOND) + (random_rand() % (60 * CLOCK_SECOND));
if(target_refresh > safety_margin) {
target_refresh -= safety_margin;
}
/* Increment next sequno */
RPL_LOLLIPOP_INCREMENT(curr_instance.dag.dao_curr_seqno);
ctimer_set(&curr_instance.dag.dao_timer, target_refresh, handle_dao_timer, NULL);
}
}
/*---------------------------------------------------------------------------*/
void
rpl_timers_schedule_dao(void)
{
if(curr_instance.used && curr_instance.mop != RPL_MOP_NO_DOWNWARD_ROUTES) {
/* No need for aggregation delay as per RFC 6550 section 9.5, as this only
* serves storing mode. Use simply delay instead, with the only PURPOSE
* to reduce congestion. */
clock_time_t expiration_time = RPL_DAO_DELAY / 2 + (random_rand() % (RPL_DAO_DELAY));
/* Increment next seqno */
RPL_LOLLIPOP_INCREMENT(curr_instance.dag.dao_curr_seqno);
ctimer_set(&curr_instance.dag.dao_timer, expiration_time, handle_dao_timer, NULL);
}
}
/*---------------------------------------------------------------------------*/
static void
handle_dao_timer(void *ptr)
{
#if RPL_WITH_DAO_ACK
if(rpl_lollipop_greater_than(curr_instance.dag.dao_curr_seqno,
curr_instance.dag.dao_last_seqno)) {
/* We are sending a new DAO here. Prepare retransmissions */
curr_instance.dag.dao_transmissions = 0;
} else {
/* We are called for the same DAO again */
if(curr_instance.dag.dao_last_acked_seqno == curr_instance.dag.dao_last_seqno) {
/* The last seqno sent is ACKed! Schedule refresh to avoid route expiration */
schedule_dao_refresh();
return;
}
/* We need to re-send the last DAO */
if(curr_instance.dag.dao_transmissions >= RPL_DAO_MAX_RETRANSMISSIONS) {
/* No more retransmissions. Perform local repair and hope to find another . */
rpl_local_repair("DAO max rtx");
return;
}
}
/* Increment transmission counter before sending */
curr_instance.dag.dao_transmissions++;
/* Schedule next retransmission */
schedule_dao_retransmission();
#else /* RPL_WITH_DAO_ACK */
/* No DAO-ACK: assume we are reachable as soon as we send a DAO */
if(curr_instance.dag.state == DAG_JOINED) {
curr_instance.dag.state = DAG_REACHABLE;
}
rpl_timers_dio_reset("Reachable");
#endif /* !RPL_WITH_DAO_ACK */
curr_instance.dag.dao_last_seqno = curr_instance.dag.dao_curr_seqno;
/* Send a DAO with own prefix as target and default lifetime */
rpl_icmp6_dao_output(curr_instance.default_lifetime);
#if !RPL_WITH_DAO_ACK
/* There is DAO-ACK, schedule a refresh. Must be done after rpl_icmp6_dao_output,
because we increment curr_instance.dag.dao_curr_seqno for the next DAO (refresh) */
schedule_dao_refresh();
#endif /* !RPL_WITH_DAO_ACK */
}
#if RPL_WITH_DAO_ACK
/*---------------------------------------------------------------------------*/
/*------------------------------- DAO-ACK ---------------------------------- */
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
void
rpl_timers_schedule_dao_ack(uip_ipaddr_t *target, uint16_t sequence)
{
if(curr_instance.used) {
uip_ipaddr_copy(&curr_instance.dag.dao_ack_target, target);
curr_instance.dag.dao_ack_sequence = sequence;
ctimer_set(&curr_instance.dag.dao_ack_timer, 0, handle_dao_ack_timer, NULL);
}
}
/*---------------------------------------------------------------------------*/
static void
handle_dao_ack_timer(void *ptr)
{
rpl_icmp6_dao_ack_output(&curr_instance.dag.dao_ack_target,
curr_instance.dag.dao_ack_sequence, RPL_DAO_ACK_UNCONDITIONAL_ACCEPT);
}
#endif /* RPL_WITH_DAO_ACK */
/*---------------------------------------------------------------------------*/
/*------------------------------- Probing----------------------------------- */
/*---------------------------------------------------------------------------*/
#if RPL_WITH_PROBING
clock_time_t
get_probing_delay(void)
{
if(curr_instance.used && curr_instance.dag.urgent_probing_target != NULL) {
/* Urgent probing needed (to find out if a neighbor may become preferred parent) */
return random_rand() % (CLOCK_SECOND * 4);
} else {
/* Else, use normal probing interval */
return ((RPL_PROBING_INTERVAL) / 2) + random_rand() % (RPL_PROBING_INTERVAL);
}
}
/*---------------------------------------------------------------------------*/
rpl_nbr_t *
get_probing_target(void)
{
/* Returns the next probing target. The current implementation probes the urgent
* probing target if any, or the preferred parent if its link statistics need refresh.
* Otherwise, it picks at random between:
* (1) selecting the best neighbor with non-fresh link statistics
* (2) selecting the least recently updated neighbor
*/
rpl_nbr_t *nbr;
rpl_nbr_t *probing_target = NULL;
rpl_rank_t probing_target_rank = RPL_INFINITE_RANK;
clock_time_t probing_target_age = 0;
clock_time_t clock_now = clock_time();
if(curr_instance.used == 0) {
return NULL;
}
/* There is an urgent probing target */
if(curr_instance.dag.urgent_probing_target != NULL) {
return curr_instance.dag.urgent_probing_target;
}
/* The preferred parent needs probing */
if(curr_instance.dag.preferred_parent != NULL && !rpl_neighbor_is_fresh(curr_instance.dag.preferred_parent)) {
return curr_instance.dag.preferred_parent;
}
/* Now consider probing other non-fresh neighbors. With 2/3 proabability,
pick the best non-fresh. Otherwise, pick the lest recently updated non-fresh. */
if(random_rand() % 3 != 0) {
/* Look for best non-fresh */
nbr = nbr_table_head(rpl_neighbors);
while(nbr != NULL) {
if(!rpl_neighbor_is_fresh(nbr)) {
/* nbr needs probing */
rpl_rank_t nbr_rank = rpl_neighbor_rank_via_nbr(nbr);
if(probing_target == NULL
|| nbr_rank < probing_target_rank) {
probing_target = nbr;
probing_target_rank = nbr_rank;
}
}
nbr = nbr_table_next(rpl_neighbors, nbr);
}
} else {
/* Look for least recently updated non-fresh */
nbr = nbr_table_head(rpl_neighbors);
while(nbr != NULL) {
if(!rpl_neighbor_is_fresh(nbr)) {
/* nbr needs probing */
const struct link_stats *stats = rpl_neighbor_get_link_stats(nbr);
if(stats != NULL) {
if(probing_target == NULL
|| clock_now - stats->last_tx_time > probing_target_age) {
probing_target = nbr;
probing_target_age = clock_now - stats->last_tx_time;
}
}
}
nbr = nbr_table_next(rpl_neighbors, nbr);
}
}
return probing_target;
}
/*---------------------------------------------------------------------------*/
static void
handle_probing_timer(void *ptr)
{
rpl_nbr_t *probing_target = RPL_PROBING_SELECT_FUNC();
uip_ipaddr_t *target_ipaddr = rpl_neighbor_get_ipaddr(probing_target);
/* Perform probing */
if(target_ipaddr != NULL) {
const struct link_stats *stats = rpl_neighbor_get_link_stats(probing_target);
(void)stats;
LOG_INFO("probing ");
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LOG_INFO_6ADDR(target_ipaddr);
LOG_INFO_(" %s last tx %u min ago\n",
curr_instance.dag.urgent_probing_target != NULL ? "(urgent)" : "",
probing_target != NULL ?
(unsigned)((clock_time() - stats->last_tx_time) / (60 * CLOCK_SECOND)) : 0
);
/* Send probe, e.g. unicast DIO or DIS */
RPL_PROBING_SEND_FUNC(target_ipaddr);
curr_instance.dag.urgent_probing_target = NULL;
} else {
LOG_INFO("no neighbor needs probing\n");
}
/* Schedule next probing */
rpl_schedule_probing();
}
/*---------------------------------------------------------------------------*/
void
rpl_schedule_probing(void)
{
if(curr_instance.used) {
ctimer_set(&curr_instance.dag.probing_timer, RPL_PROBING_DELAY_FUNC(),
handle_probing_timer, NULL);
}
}
#endif /* RPL_WITH_PROBING */
/*---------------------------------------------------------------------------*/
/*------------------------------- Leaving-- -------------------------------- */
/*---------------------------------------------------------------------------*/
static void
handle_leaving_timer(void *ptr)
{
if(curr_instance.used) {
rpl_dag_leave();
}
}
/*---------------------------------------------------------------------------*/
void
rpl_timers_unschedule_leaving(void)
{
if(curr_instance.used) {
if(!ctimer_expired(&curr_instance.dag.leave)) {
ctimer_stop(&curr_instance.dag.leave);
}
}
}
/*---------------------------------------------------------------------------*/
void
rpl_timers_schedule_leaving(void)
{
if(curr_instance.used) {
if(ctimer_expired(&curr_instance.dag.leave)) {
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ctimer_set(&curr_instance.dag.leave, RPL_DELAY_BEFORE_LEAVING, handle_leaving_timer, NULL);
}
}
}
/*---------------------------------------------------------------------------*/
/*------------------------------- Periodic---------------------------------- */
/*---------------------------------------------------------------------------*/
void
rpl_timers_init(void)
{
ctimer_set(&periodic_timer, PERIODIC_DELAY, handle_periodic_timer, NULL);
rpl_timers_schedule_periodic_dis();
}
/*---------------------------------------------------------------------------*/
static void
handle_periodic_timer(void *ptr)
{
if(curr_instance.used) {
rpl_dag_periodic(PERIODIC_DELAY_SECONDS);
rpl_ns_periodic(PERIODIC_DELAY_SECONDS);
}
if(!curr_instance.used ||
curr_instance.dag.preferred_parent == NULL ||
curr_instance.dag.rank == RPL_INFINITE_RANK) {
rpl_timers_schedule_periodic_dis(); /* Schedule DIS if needed */
}
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/* Useful because part of the state update is time-dependent, e.g.,
the meaning of last_advertised_rank changes with time */
rpl_dag_update_state();
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#if LOG_INFO_ENABLED
rpl_neighbor_print_list("Periodic");
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#endif /* LOG_INFO_ENABLED */
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ctimer_reset(&periodic_timer);
}
/*---------------------------------------------------------------------------*/
void
rpl_timers_stop_dag_timers(void)
{
/* Stop all timers related to the DAG */
ctimer_stop(&curr_instance.dag.state_update);
ctimer_stop(&curr_instance.dag.leave);
ctimer_stop(&curr_instance.dag.dio_timer);
ctimer_stop(&curr_instance.dag.unicast_dio_timer);
ctimer_stop(&curr_instance.dag.dao_timer);
#if RPL_WITH_PROBING
ctimer_stop(&curr_instance.dag.probing_timer);
#endif /* RPL_WITH_PROBING */
#if RPL_WITH_DAO_ACK
ctimer_stop(&curr_instance.dag.dao_ack_timer);
#endif /* RPL_WITH_DAO_ACK */
}
/*---------------------------------------------------------------------------*/
void
rpl_timers_unschedule_state_update(void)
{
if(curr_instance.used) {
ctimer_stop(&curr_instance.dag.state_update);
}
}
/*---------------------------------------------------------------------------*/
void
rpl_timers_schedule_state_update(void)
{
if(curr_instance.used) {
ctimer_set(&curr_instance.dag.state_update, 0, handle_state_update, NULL);
}
}
/*---------------------------------------------------------------------------*/
static void
handle_state_update(void *ptr)
{
rpl_dag_update_state();
}
/** @}*/