osd-contiki/core/net/neighbor-info.c
2010-03-25 19:30:44 +00:00

177 lines
5.3 KiB
C

/*
* 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.
*
* $Id: neighbor-info.c,v 1.5 2010/03/25 19:30:44 nifi Exp $
*/
/**
* \file
* A generic module for management of neighbor information.
*
* \author Nicolas Tsiftes <nvt@sics.se>
*/
#include "net/neighbor-info.h"
#include "net/neighbor-attr.h"
#define DEBUG 0
#if DEBUG
#include <stdio.h>
#define PRINTF(...) printf(__VA_ARGS__)
#else
#define PRINTF(...)
#endif /* DEBUG */
#ifndef ETX_CONF_LIMIT
#define ETX_LIMIT 10
#else
#define ETX_LIMIT ETX_CONF_LIMIT
#endif /* !ETX_CONF_LIMIT */
#define ETX_SCALE 100
#define ETX_ALPHA 60
#define ETX_FIRST_GUESS (ETX_LIMIT - 1)
#define ETX_COLLISION_PENALTY 5
#define ETX_NO_ACK_PENALTY (ETX_LIMIT + 1)
/*---------------------------------------------------------------------------*/
NEIGHBOR_ATTRIBUTE(uint8_t, etx, NULL);
static neighbor_info_subscriber_t subscriber_callback;
/*---------------------------------------------------------------------------*/
static void
update_etx(const rimeaddr_t *dest, int packet_etx)
{
uint8_t *etxp;
uint8_t recorded_etx, new_etx;
etxp = (uint8_t *)neighbor_attr_get_data(&etx, dest);
if(etxp == NULL || *etxp == 0) {
recorded_etx = ETX_FIRST_GUESS;
} else {
recorded_etx = *etxp;
}
/* Update the EWMA of the ETX for the neighbor. */
new_etx = (ETX_SCALE / 2 + ETX_ALPHA * recorded_etx +
(ETX_SCALE - ETX_ALPHA) * packet_etx) / ETX_SCALE;
PRINTF("neighbor-info: ETX changed from %d to %d (packet ETX = %d)\n",
recorded_etx, new_etx, packet_etx);
if(new_etx > ETX_LIMIT) {
neighbor_attr_remove_neighbor(dest);
if(subscriber_callback != NULL) {
subscriber_callback(dest, 0, new_etx);
}
} else if(neighbor_attr_has_neighbor(dest)) {
neighbor_attr_set_data(&etx, dest, &new_etx);
if(new_etx != recorded_etx && subscriber_callback != NULL) {
subscriber_callback(dest, 1, new_etx);
}
}
}
/*---------------------------------------------------------------------------*/
static void
add_neighbor(const rimeaddr_t *addr)
{
switch(neighbor_attr_add_neighbor(addr)) {
case -1:
PRINTF("neighbor-info: failed to add a node.\n");
break;
case 0:
PRINTF("neighbor-info: The neighbor is already known\n");
break;
default:
if(subscriber_callback != NULL) {
subscriber_callback(addr, 1, ETX_FIRST_GUESS);
}
break;
}
}
/*---------------------------------------------------------------------------*/
void
neighbor_info_packet_sent(int status, int numtx)
{
const rimeaddr_t *dest;
uint8_t packet_etx;
dest = packetbuf_addr(PACKETBUF_ADDR_RECEIVER);
if(rimeaddr_cmp(dest, &rimeaddr_null)) {
return;
}
PRINTF("neighbor-info: packet sent to %d.%d, status=%d, numtx=%d\n",
dest->u8[sizeof(*dest) - 2], dest->u8[sizeof(*dest) - 1],
status, numtx);
packet_etx = numtx;
switch(status) {
case MAC_TX_OK:
add_neighbor(dest);
break;
case MAC_TX_COLLISION:
packet_etx += ETX_COLLISION_PENALTY;
break;
case MAC_TX_NOACK:
packet_etx += ETX_NO_ACK_PENALTY;
break;
default:
break;
}
update_etx(dest, packet_etx);
}
/*---------------------------------------------------------------------------*/
void
neighbor_info_packet_received(void)
{
const rimeaddr_t *src;
src = packetbuf_addr(PACKETBUF_ADDR_SENDER);
if(rimeaddr_cmp(src, &rimeaddr_null)) {
return;
}
PRINTF("neighbor-info: packet received from %d.%d\n",
src->u8[sizeof(*src) - 2], src->u8[sizeof(*src) - 1]);
add_neighbor(src);
}
/*---------------------------------------------------------------------------*/
int
neighbor_info_subscribe(neighbor_info_subscriber_t s)
{
if(subscriber_callback == NULL) {
subscriber_callback = s;
return 1;
}
return 0;
}
/*---------------------------------------------------------------------------*/