contiki/core/net/mac/nullmac.c
adamdunkels 7ad93e5d18 Added a field to the struct mac interface:
channel_check_interval(). This function returns the interval by which
the duty cycling mechanism checks the radio channel for activity. It
is used by higher layer mechanisms to determine suitable timeouts for
retransmissions.
2010-01-25 11:43:32 +00:00

122 lines
3.8 KiB
C

/*
* Copyright (c) 2007, 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: nullmac.c,v 1.13 2010/01/25 11:43:32 adamdunkels Exp $
*/
/**
* \file
* A MAC protocol that does not do anything.
* \author
* Adam Dunkels <adam@sics.se>
*/
#include "net/mac/nullmac.h"
#include "net/rime/packetbuf.h"
static const struct radio_driver *radio;
static void (* receiver_callback)(const struct mac_driver *);
/*---------------------------------------------------------------------------*/
static int
send_packet(void)
{
if(radio->send(packetbuf_hdrptr(), packetbuf_totlen()) == RADIO_TX_OK) {
return MAC_TX_OK;
}
return MAC_TX_ERR;
}
/*---------------------------------------------------------------------------*/
static void
input_packet(const struct radio_driver *d)
{
if(receiver_callback) {
receiver_callback(&nullmac_driver);
}
}
/*---------------------------------------------------------------------------*/
static int
read_packet(void)
{
int len;
packetbuf_clear();
len = radio->read(packetbuf_dataptr(), PACKETBUF_SIZE);
packetbuf_set_datalen(len);
return len;
}
/*---------------------------------------------------------------------------*/
static void
set_receive_function(void (* recv)(const struct mac_driver *))
{
receiver_callback = recv;
}
/*---------------------------------------------------------------------------*/
static int
on(void)
{
return radio->on();
}
/*---------------------------------------------------------------------------*/
static int
off(int keep_radio_on)
{
if(keep_radio_on) {
return radio->on();
} else {
return radio->off();
}
}
/*---------------------------------------------------------------------------*/
static unsigned short
channel_check_interval(void)
{
return 0;
}
/*---------------------------------------------------------------------------*/
const struct mac_driver nullmac_driver = {
"nullmac",
nullmac_init,
send_packet,
read_packet,
set_receive_function,
on,
off,
channel_check_interval,
};
/*---------------------------------------------------------------------------*/
const struct mac_driver *
nullmac_init(const struct radio_driver *d)
{
radio = d;
radio->set_receive_function(input_packet);
radio->on();
return &nullmac_driver;
}
/*---------------------------------------------------------------------------*/