contiki/core/net/rime/neighbor.c

266 lines
7.3 KiB
C

/**
* \addtogroup rimeneighbor
* @{
*/
/*
* Copyright (c) 2006, 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.
*
* $Id: neighbor.c,v 1.10 2007/11/13 20:39:29 adamdunkels Exp $
*/
/**
* \file
* Radio neighborhood management
* \author
* Adam Dunkels <adam@sics.se>
*/
#include <limits.h>
#include <stdio.h>
#include "contiki.h"
#include "net/rime/neighbor.h"
#include "net/rime/ctimer.h"
#define MAX_NEIGHBORS 5
#define RTMETRIC_MAX 64
static struct neighbor neighbors[MAX_NEIGHBORS];
static struct ctimer t;
static int max_time = 30;
/*---------------------------------------------------------------------------*/
static void
periodic(void *ptr)
{
int i;
/* Go through all neighbors and remove old ones. */
for(i = 0; i < MAX_NEIGHBORS; ++i) {
if(!rimeaddr_cmp(&neighbors[i].addr, &rimeaddr_null) &&
neighbors[i].time < max_time) {
neighbors[i].time++;
if(neighbors[i].time == max_time) {
neighbors[i].rtmetric = RTMETRIC_MAX;
/* printf("%d: removing old neighbor %d\n", node_id, neighbors[i].nodeid);*/
rimeaddr_copy(&neighbors[i].addr, &rimeaddr_null);
}
}
}
/* printf("neighbor periodic\n");*/
ctimer_set(&t, CLOCK_SECOND, periodic, NULL);
}
/*---------------------------------------------------------------------------*/
void
neighbor_init(void)
{
int i;
for(i = 0; i < MAX_NEIGHBORS; ++i) {
rimeaddr_copy(&neighbors[i].addr, &rimeaddr_null);
}
ctimer_set(&t, CLOCK_SECOND, periodic, NULL);
}
/*---------------------------------------------------------------------------*/
struct neighbor *
neighbor_find(rimeaddr_t *addr)
{
int i;
for(i = 0; i < MAX_NEIGHBORS; ++i) {
if(rimeaddr_cmp(&neighbors[i].addr, addr)) {
return &neighbors[i];
}
}
return NULL;
}
/*---------------------------------------------------------------------------*/
void
neighbor_update(struct neighbor *n, u8_t rtmetric, u8_t etx)
{
if(n != NULL) {
n->rtmetric = rtmetric;
n->time = 0;
neighbor_update_etx(n, etx);
}
}
/*---------------------------------------------------------------------------*/
void
neighbor_timedout_etx(struct neighbor *n, u8_t etx)
{
if(n != NULL) {
n->etxs[n->etxptr] = etx;
n->etxptr = (n->etxptr + 1) % NEIGHBOR_NUM_ETXS;
}
}
/*---------------------------------------------------------------------------*/
void
neighbor_update_etx(struct neighbor *n, u8_t etx)
{
if(n != NULL) {
n->etxs[n->etxptr] = etx;
n->etxptr = (n->etxptr + 1) % NEIGHBOR_NUM_ETXS;
n->time = 0;
}
}
/*---------------------------------------------------------------------------*/
uint8_t
neighbor_etx(struct neighbor *n)
{
int i, etx;
etx = 0;
for(i = 0; i < NEIGHBOR_NUM_ETXS; ++i) {
etx += n->etxs[i];
}
return NEIGHBOR_ETX_SCALE * etx / NEIGHBOR_NUM_ETXS;
}
/*---------------------------------------------------------------------------*/
void
neighbor_add(rimeaddr_t *addr, u8_t nrtmetric, u8_t netx)
{
int i, n;
u8_t rtmetric;
u8_t etx;
/* Find the first unused entry or the used entry with the highest
rtmetric and highest etx. */
rtmetric = 0;
etx = 0;
n = 0;
for(i = 0; i < MAX_NEIGHBORS; ++i) {
if(rimeaddr_cmp(&neighbors[i].addr, &rimeaddr_null) ||
rimeaddr_cmp(&neighbors[i].addr, addr)) {
n = i;
break;
}
if(!rimeaddr_cmp(&neighbors[i].addr, &rimeaddr_null)) {
if(neighbors[i].rtmetric > rtmetric) {
rtmetric = neighbors[i].rtmetric;
etx = neighbor_etx(&neighbors[i]);
n = i;
} else if(neighbors[i].rtmetric == rtmetric) {
if(neighbor_etx(&neighbors[i]) > etx) {
rtmetric = neighbors[i].rtmetric;
etx = neighbor_etx(&neighbors[i]);
n = i;
/* printf("%d: found worst neighbor %d with rtmetric %d, signal %d\n",
node_id, neighbors[n].nodeid, rtmetric, signal);*/
}
}
}
}
/* printf("%d: adding neighbor %d with rtmetric %d, signal %d at %d\n",
node_id, neighbors[n].nodeid, rtmetric, signal, n);*/
neighbors[n].time = 0;
rimeaddr_copy(&neighbors[i].addr, addr);
neighbors[n].rtmetric = nrtmetric;
for(i = 0; i < NEIGHBOR_NUM_ETXS; ++i) {
neighbors[n].etxs[i] = netx;
}
neighbors[n].etxptr = 0;
}
/*---------------------------------------------------------------------------*/
void
neighbor_remove(rimeaddr_t *addr)
{
int i;
for(i = 0; i < MAX_NEIGHBORS; ++i) {
if(rimeaddr_cmp(&neighbors[i].addr, addr)) {
printf("%d: removing %d @ %d\n", rimeaddr_node_addr.u16[0], addr->u16[0], i);
rimeaddr_copy(&neighbors[i].addr, &rimeaddr_null);
neighbors[i].rtmetric = RTMETRIC_MAX;
return;
}
}
}
/*---------------------------------------------------------------------------*/
struct neighbor *
neighbor_best(void)
{
int i, found;
int lowest, best;
u8_t rtmetric;
u8_t etx;
rtmetric = RTMETRIC_MAX;
lowest = 0;
found = 0;
/* printf("%d: ", node_id);*/
/* Find the lowest rtmetric. */
for(i = 0; i < MAX_NEIGHBORS; ++i) {
/* printf("%d:%d ", neighbors[i].nodeid, neighbors[i].rtmetric);*/
if(!rimeaddr_cmp(&neighbors[i].addr, &rimeaddr_null) &&
rtmetric > neighbors[i].rtmetric) {
rtmetric = neighbors[i].rtmetric;
lowest = i;
found = 1;
}
}
/* printf("\n");*/
/* Find the neighbor with lowest etx of the ones that
have the lowest rtmetric. */
if(found) {
etx = 0;
best = lowest;
for(i = 0; i < MAX_NEIGHBORS; ++i) {
if(!rimeaddr_cmp(&neighbors[i].addr, &rimeaddr_null) &&
rtmetric == neighbors[i].rtmetric &&
neighbor_etx(&neighbors[i]) < etx) {
etx = neighbor_etx(&neighbors[i]);
best = i;
}
}
return &neighbors[best];
}
return NULL;
}
/*---------------------------------------------------------------------------*/
void
neighbor_set_lifetime(int seconds)
{
max_time = seconds;
}
/*---------------------------------------------------------------------------*/
/** @} */