203 lines
6.1 KiB
C
203 lines
6.1 KiB
C
/**
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* \addtogroup uip6
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* @{
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*/
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/*
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* Copyright (c) 2010, Swedish Institute of Computer Science.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the Institute nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* This file is part of the Contiki operating system.
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*
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*/
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/**
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* \file
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* The minrank-hysteresis objective function (OCP 1).
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*
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* This implementation uses the estimated number of
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* transmissions (ETX) as the additive routing metric.
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*
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* \author Joakim Eriksson <joakime@sics.se>, Nicolas Tsiftes <nvt@sics.se>
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*/
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#include "net/rpl/rpl-private.h"
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#include "net/neighbor-info.h"
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#define DEBUG DEBUG_NONE
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#include "net/uip-debug.h"
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static void reset(rpl_dag_t *);
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static void parent_state_callback(rpl_parent_t *, int, int);
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static rpl_parent_t *best_parent(rpl_parent_t *, rpl_parent_t *);
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static rpl_rank_t calculate_rank(rpl_parent_t *, rpl_rank_t);
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static void update_metric_container(rpl_dag_t *);
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rpl_of_t rpl_of_etx = {
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reset,
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parent_state_callback,
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best_parent,
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calculate_rank,
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update_metric_container,
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1
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};
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#define NI_ETX_TO_RPL_ETX(etx) \
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((etx) * (RPL_DAG_MC_ETX_DIVISOR / NEIGHBOR_INFO_ETX_DIVISOR))
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#define rpl_path_metric_tO_NI_ETX(etx) \
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((etx) / (RPL_DAG_MC_ETX_DIVISOR / NEIGHBOR_INFO_ETX_DIVISOR))
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/* Reject parents that have a higher link metric than the following. */
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#define MAX_LINK_METRIC 10
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/* Reject parents that have a higher path cost than the following. */
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#define MAX_PATH_COST 100
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/* An initial guess of the link metric. */
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#define INITIAL_LINK_METRIC 3
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/*
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* The rank must differ more than 1/PARENT_SWITCH_THRESHOLD_DIV in order
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* to switch preferred parent.
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*/
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#define PARENT_SWITCH_THRESHOLD_DIV 2
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typedef uint16_t rpl_path_metric_t;
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static uint16_t
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calculate_path_metric(rpl_parent_t *p)
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{
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return p->mc.obj.etx + NI_ETX_TO_RPL_ETX(p->etx);
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}
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static void
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reset(rpl_dag_t *dag)
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{
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}
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static void
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parent_state_callback(rpl_parent_t *parent, int known, int etx)
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{
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}
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static rpl_rank_t
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calculate_rank(rpl_parent_t *p, rpl_rank_t base_rank)
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{
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rpl_rank_t new_rank;
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rpl_rank_t rank_increase;
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if(p == NULL) {
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if(base_rank == 0) {
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return INFINITE_RANK;
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}
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rank_increase = INITIAL_LINK_METRIC * DEFAULT_MIN_HOPRANKINC;
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} else {
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if(p->etx == 0) {
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p->etx = INITIAL_LINK_METRIC * NEIGHBOR_INFO_ETX_DIVISOR;
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}
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rank_increase = (p->etx * p->dag->min_hoprankinc) / NEIGHBOR_INFO_ETX_DIVISOR;
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if(base_rank == 0) {
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base_rank = p->rank;
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}
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}
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if(INFINITE_RANK - base_rank < rank_increase) {
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/* Reached the maximum rank. */
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new_rank = INFINITE_RANK;
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} else {
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/* Calculate the rank based on the new rank information from DIO or
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stored otherwise. */
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new_rank = base_rank + rank_increase;
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}
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return new_rank;
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}
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static rpl_parent_t *
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best_parent(rpl_parent_t *p1, rpl_parent_t *p2)
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{
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rpl_dag_t *dag;
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rpl_path_metric_t min_diff;
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rpl_path_metric_t p1_metric;
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rpl_path_metric_t p2_metric;
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dag = p1->dag; /* Both parents must be in the same DAG. */
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min_diff = RPL_DAG_MC_ETX_DIVISOR /
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PARENT_SWITCH_THRESHOLD_DIV;
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p1_metric = calculate_path_metric(p1);
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p2_metric = calculate_path_metric(p2);
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/* Maintain stability of the preferred parent in case of similar ranks. */
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if(p1 == dag->preferred_parent || p2 == dag->preferred_parent) {
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if(p1_metric < p2_metric + min_diff &&
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p1_metric > p2_metric - min_diff) {
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PRINTF("RPL: MRHOF hysteresis: %u <= %u <= %u\n",
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p2_metric - min_diff,
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p1_metric,
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p2_metric + min_diff);
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return dag->preferred_parent;
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}
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}
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return p1_metric < p2_metric ? p1 : p2;
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}
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static void
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update_metric_container(rpl_dag_t *dag)
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{
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#if RPL_DAG_MC == RPL_DAG_MC_ETX
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dag->mc.type = RPL_DAG_MC_ETX;
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dag->mc.flags = RPL_DAG_MC_FLAG_P;
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dag->mc.aggr = RPL_DAG_MC_AGGR_ADDITIVE;
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dag->mc.prec = 0;
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dag->mc.length = sizeof(dag->mc.obj.etx);
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if(dag->rank == ROOT_RANK(dag)) {
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dag->mc.obj.etx = 0;
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} else {
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dag->mc.obj.etx = calculate_path_metric(dag->preferred_parent);
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}
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#elif RPL_DAG_MC == RPL_DAG_MC_ENERGY
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dag->mc.type = RPL_DAG_MC_ENERGY;
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dag->mc.flags = RPL_DAG_MC_FLAG_P;
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dag->mc.aggr = RPL_DAG_MC_AGGR_ADDITIVE;
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dag->mc.prec = 0;
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dag->mc.length = sizeof(dag->mc.obj.energy);
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if(dag->rank == ROOT_RANK(dag)) {
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dag->mc.obj.energy.flags = RPL_DAG_MC_ENERGY_TYPE_MAINS << RPL_DAG_MC_ENERGY_TYPE;
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} else {
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dag->mc.obj.energy.flags = RPL_DAG_MC_ENERGY_TYPE_BATTERY << RPL_DAG_MC_ENERGY_TYPE;
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}
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dag->mc.obj.energy.energy_est = calculate_path_metric(dag->preferred_parent);
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#else
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#error "Unsupported RPL_DAG_MC configured. See rpl.h."
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#endif /* RPL_DAG_MC */
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PRINTF("RPL: My path ETX to the root is %u.%u\n",
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dag->mc.obj.etx / RPL_DAG_MC_ETX_DIVISOR,
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(dag->mc.obj.etx % RPL_DAG_MC_ETX_DIVISOR * 100) / RPL_DAG_MC_ETX_DIVISOR);
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}
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