365 lines
11 KiB
C
365 lines
11 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: csma.c,v 1.27 2011/01/25 14:24:38 adamdunkels Exp $
|
|
*/
|
|
|
|
/**
|
|
* \file
|
|
* A Carrier Sense Multiple Access (CSMA) MAC layer
|
|
* \author
|
|
* Adam Dunkels <adam@sics.se>
|
|
*/
|
|
|
|
#include "net/mac/csma.h"
|
|
#include "net/packetbuf.h"
|
|
#include "net/queuebuf.h"
|
|
|
|
#include "sys/ctimer.h"
|
|
|
|
#include "lib/random.h"
|
|
|
|
#include "net/netstack.h"
|
|
|
|
#include "lib/list.h"
|
|
#include "lib/memb.h"
|
|
|
|
#include <string.h>
|
|
|
|
#include <stdio.h>
|
|
|
|
#define DEBUG 0
|
|
#if DEBUG
|
|
#include <stdio.h>
|
|
#define PRINTF(...) printf(__VA_ARGS__)
|
|
#else /* DEBUG */
|
|
#define PRINTF(...)
|
|
#endif /* DEBUG */
|
|
|
|
#ifndef CSMA_MAX_MAC_TRANSMISSIONS
|
|
#ifdef CSMA_CONF_MAX_MAC_TRANSMISSIONS
|
|
#define CSMA_MAX_MAC_TRANSMISSIONS CSMA_CONF_MAX_MAC_TRANSMISSIONS
|
|
#else
|
|
#define CSMA_MAX_MAC_TRANSMISSIONS 3
|
|
#endif /* CSMA_CONF_MAX_MAC_TRANSMISSIONS */
|
|
#endif /* CSMA_MAX_MAC_TRANSMISSIONS */
|
|
|
|
#if CSMA_MAX_MAC_TRANSMISSIONS < 1
|
|
#error CSMA_CONF_MAX_MAC_TRANSMISSIONS must be at least 1.
|
|
#error Change CSMA_CONF_MAX_MAC_TRANSMISSIONS in contiki-conf.h or in your Makefile.
|
|
#endif /* CSMA_CONF_MAX_MAC_TRANSMISSIONS < 1 */
|
|
|
|
struct queued_packet {
|
|
struct queued_packet *next;
|
|
struct queuebuf *buf;
|
|
/* struct ctimer retransmit_timer;*/
|
|
mac_callback_t sent;
|
|
void *cptr;
|
|
uint8_t transmissions, max_transmissions;
|
|
uint8_t collisions, deferrals;
|
|
};
|
|
|
|
#define MAX_QUEUED_PACKETS 6
|
|
MEMB(packet_memb, struct queued_packet, MAX_QUEUED_PACKETS);
|
|
LIST(queued_packet_list);
|
|
|
|
static struct ctimer transmit_timer;
|
|
|
|
static uint8_t rdc_is_transmitting;
|
|
|
|
static void packet_sent(void *ptr, int status, int num_transmissions);
|
|
|
|
/*---------------------------------------------------------------------------*/
|
|
static clock_time_t
|
|
default_timebase(void)
|
|
{
|
|
clock_time_t time;
|
|
/* The retransmission time must be proportional to the channel
|
|
check interval of the underlying radio duty cycling layer. */
|
|
time = NETSTACK_RDC.channel_check_interval();
|
|
|
|
/* If the radio duty cycle has no channel check interval (i.e., it
|
|
does not turn the radio off), we make the retransmission time
|
|
proportional to the configured MAC channel check rate. */
|
|
if(time == 0) {
|
|
time = CLOCK_SECOND / NETSTACK_RDC_CHANNEL_CHECK_RATE;
|
|
}
|
|
return time;
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
static void
|
|
transmit_queued_packet(void *ptr)
|
|
{
|
|
/* struct queued_packet *q = ptr;*/
|
|
struct queued_packet *q;
|
|
|
|
/* Don't transmit a packet if the RDC is still transmitting the
|
|
previous one. */
|
|
if(rdc_is_transmitting) {
|
|
return;
|
|
}
|
|
|
|
// printf("q %d\n", list_length(queued_packet_list));
|
|
|
|
q = list_head(queued_packet_list);
|
|
|
|
if(q != NULL) {
|
|
queuebuf_to_packetbuf(q->buf);
|
|
PRINTF("csma: sending number %d %p, queue len %d\n", q->transmissions, q,
|
|
list_length(queued_packet_list));
|
|
// printf("s %d\n", packetbuf_addr(PACKETBUF_ADDR_RECEIVER)->u8[0]);
|
|
rdc_is_transmitting = 1;
|
|
NETSTACK_RDC.send(packet_sent, q);
|
|
}
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
static void
|
|
start_transmission_timer(void)
|
|
{
|
|
PRINTF("csma: start_transmission_timer, queue len %d\n",
|
|
list_length(queued_packet_list));
|
|
if(list_length(queued_packet_list) > 0) {
|
|
if(ctimer_expired(&transmit_timer)) {
|
|
ctimer_set(&transmit_timer, 0,
|
|
transmit_queued_packet, NULL);
|
|
}
|
|
}
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
static void
|
|
free_queued_packet(void)
|
|
{
|
|
struct queued_packet *q;
|
|
|
|
// printf("q %d\n", list_length(queued_packet_list));
|
|
|
|
q = list_head(queued_packet_list);
|
|
|
|
if(q != NULL) {
|
|
queuebuf_free(q->buf);
|
|
list_remove(queued_packet_list, q);
|
|
memb_free(&packet_memb, q);
|
|
PRINTF("csma: free_queued_packet, queue length %d\n",
|
|
list_length(queued_packet_list));
|
|
if(list_length(queued_packet_list) > 0) {
|
|
ctimer_set(&transmit_timer, default_timebase(), transmit_queued_packet, NULL);
|
|
}
|
|
}
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
static void
|
|
packet_sent(void *ptr, int status, int num_transmissions)
|
|
{
|
|
struct queued_packet *q = ptr;
|
|
clock_time_t time = 0;
|
|
mac_callback_t sent;
|
|
void *cptr;
|
|
int num_tx;
|
|
int backoff_transmissions;
|
|
|
|
rdc_is_transmitting = 0;
|
|
|
|
switch(status) {
|
|
case MAC_TX_OK:
|
|
case MAC_TX_NOACK:
|
|
q->transmissions++;
|
|
break;
|
|
case MAC_TX_COLLISION:
|
|
q->collisions++;
|
|
break;
|
|
case MAC_TX_DEFERRED:
|
|
q->deferrals++;
|
|
break;
|
|
}
|
|
|
|
sent = q->sent;
|
|
cptr = q->cptr;
|
|
num_tx = q->transmissions;
|
|
|
|
if(status == MAC_TX_COLLISION ||
|
|
status == MAC_TX_NOACK) {
|
|
|
|
/* If the transmission was not performed because of a collision or
|
|
noack, we must retransmit the packet. */
|
|
|
|
switch(status) {
|
|
case MAC_TX_COLLISION:
|
|
PRINTF("csma: rexmit collision %d\n", q->transmissions);
|
|
break;
|
|
case MAC_TX_NOACK:
|
|
PRINTF("csma: rexmit noack %d\n", q->transmissions);
|
|
break;
|
|
default:
|
|
PRINTF("csma: rexmit err %d, %d\n", status, q->transmissions);
|
|
}
|
|
|
|
/* The retransmission time must be proportional to the channel
|
|
check interval of the underlying radio duty cycling layer. */
|
|
time = default_timebase();
|
|
|
|
/* The retransmission time uses a linear backoff so that the
|
|
interval between the transmissions increase with each
|
|
retransmit. */
|
|
backoff_transmissions = q->transmissions + 1;
|
|
|
|
/* Clamp the number of backoffs so that we don't get a too long
|
|
timeout here, since that will delay all packets in the
|
|
queue. */
|
|
if(backoff_transmissions > 3) {
|
|
backoff_transmissions = 3;
|
|
}
|
|
time = time + (random_rand() % (backoff_transmissions * time));
|
|
|
|
if(q->transmissions < q->max_transmissions) {
|
|
PRINTF("csma: retransmitting with time %lu %p\n", time, q);
|
|
ctimer_set(&transmit_timer, time,
|
|
transmit_queued_packet, NULL);
|
|
|
|
/* This is needed to correctly attribute energy that we spent
|
|
transmitting this packet. */
|
|
q = list_head(queued_packet_list);
|
|
queuebuf_free(q->buf);
|
|
q->buf = queuebuf_new_from_packetbuf();
|
|
|
|
} else {
|
|
PRINTF("csma: drop with status %d after %d transmissions, %d collisions\n",
|
|
status, q->transmissions, q->collisions);
|
|
/* queuebuf_to_packetbuf(q->buf);*/
|
|
free_queued_packet();
|
|
mac_call_sent_callback(sent, cptr, status, num_tx);
|
|
}
|
|
} else {
|
|
if(status == MAC_TX_OK) {
|
|
PRINTF("csma: rexmit ok %d\n", q->transmissions);
|
|
} else {
|
|
PRINTF("csma: rexmit failed %d: %d\n", q->transmissions, status);
|
|
}
|
|
/* queuebuf_to_packetbuf(q->buf);*/
|
|
free_queued_packet();
|
|
mac_call_sent_callback(sent, cptr, status, num_tx);
|
|
}
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
static void
|
|
send_packet(mac_callback_t sent, void *ptr)
|
|
{
|
|
struct queued_packet *q;
|
|
static uint16_t seqno;
|
|
|
|
packetbuf_set_attr(PACKETBUF_ATTR_MAC_SEQNO, seqno++);
|
|
|
|
/* If the packet is a broadcast, do not allocate a queue
|
|
entry. Instead, just send it out. */
|
|
if(!rimeaddr_cmp(packetbuf_addr(PACKETBUF_ADDR_RECEIVER),
|
|
&rimeaddr_null)) {
|
|
|
|
/* Remember packet for later. */
|
|
q = memb_alloc(&packet_memb);
|
|
if(q != NULL) {
|
|
q->buf = queuebuf_new_from_packetbuf();
|
|
if(q->buf != NULL) {
|
|
if(packetbuf_attr(PACKETBUF_ATTR_MAX_MAC_TRANSMISSIONS) == 0) {
|
|
/* Use default configuration for max transmissions */
|
|
q->max_transmissions = CSMA_MAX_MAC_TRANSMISSIONS;
|
|
} else {
|
|
q->max_transmissions =
|
|
packetbuf_attr(PACKETBUF_ATTR_MAX_MAC_TRANSMISSIONS);
|
|
}
|
|
q->transmissions = 0;
|
|
q->collisions = 0;
|
|
q->deferrals = 0;
|
|
q->sent = sent;
|
|
q->cptr = ptr;
|
|
if(packetbuf_attr(PACKETBUF_ATTR_PACKET_TYPE) ==
|
|
PACKETBUF_ATTR_PACKET_TYPE_ACK) {
|
|
list_push(queued_packet_list, q);
|
|
} else {
|
|
list_add(queued_packet_list, q);
|
|
}
|
|
start_transmission_timer();
|
|
return;
|
|
}
|
|
memb_free(&packet_memb, q);
|
|
PRINTF("csma: could not allocate queuebuf, will drop if collision or noack\n");
|
|
}
|
|
PRINTF("csma: could not allocate memb, will drop if collision or noack\n");
|
|
} else {
|
|
PRINTF("csma: send broadcast (%d) or without retransmissions (%d)\n",
|
|
!rimeaddr_cmp(packetbuf_addr(PACKETBUF_ADDR_RECEIVER),
|
|
&rimeaddr_null),
|
|
packetbuf_attr(PACKETBUF_ATTR_MAX_MAC_TRANSMISSIONS));
|
|
}
|
|
NETSTACK_RDC.send(sent, ptr);
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
static void
|
|
input_packet(void)
|
|
{
|
|
NETSTACK_NETWORK.input();
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
static int
|
|
on(void)
|
|
{
|
|
return NETSTACK_RDC.on();
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
static int
|
|
off(int keep_radio_on)
|
|
{
|
|
return NETSTACK_RDC.off(keep_radio_on);
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
static unsigned short
|
|
channel_check_interval(void)
|
|
{
|
|
if(NETSTACK_RDC.channel_check_interval) {
|
|
return NETSTACK_RDC.channel_check_interval();
|
|
}
|
|
return 0;
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
static void
|
|
init(void)
|
|
{
|
|
memb_init(&packet_memb);
|
|
rdc_is_transmitting = 0;
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
const struct mac_driver csma_driver = {
|
|
"CSMA",
|
|
init,
|
|
send_packet,
|
|
input_packet,
|
|
on,
|
|
off,
|
|
channel_check_interval,
|
|
};
|
|
/*---------------------------------------------------------------------------*/
|