nes-proj/os/net/mac/csma/csma.c
2018-11-10 15:20:35 +01:00

176 lines
5.4 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.
*
*/
/**
* \file
* The 802.15.4 standard CSMA protocol (nonbeacon-enabled)
* \author
* Adam Dunkels <adam@sics.se>
* Simon Duquennoy <simon.duquennoy@inria.fr>
*/
#include "net/mac/csma/csma.h"
#include "net/mac/csma/csma-output.h"
#include "net/mac/mac-sequence.h"
#include "net/packetbuf.h"
#include "net/netstack.h"
/* Log configuration */
#include "sys/log.h"
#define LOG_MODULE "CSMA"
#define LOG_LEVEL LOG_LEVEL_MAC
static void
init_sec(void)
{
#if LLSEC802154_USES_AUX_HEADER
if(packetbuf_attr(PACKETBUF_ATTR_SECURITY_LEVEL) ==
PACKETBUF_ATTR_SECURITY_LEVEL_DEFAULT) {
packetbuf_set_attr(PACKETBUF_ATTR_SECURITY_LEVEL,
CSMA_LLSEC_SECURITY_LEVEL);
}
#endif
}
/*---------------------------------------------------------------------------*/
static void
send_packet(mac_callback_t sent, void *ptr)
{
init_sec();
csma_output_packet(sent, ptr);
}
/*---------------------------------------------------------------------------*/
static void
input_packet(void)
{
#if CSMA_SEND_SOFT_ACK
uint8_t ackdata[CSMA_ACK_LEN];
#endif
if(packetbuf_datalen() == CSMA_ACK_LEN) {
/* Ignore ack packets */
LOG_DBG("ignored ack\n");
} else if(csma_security_parse_frame() < 0) {
LOG_ERR("failed to parse %u\n", packetbuf_datalen());
} else if(!linkaddr_cmp(packetbuf_addr(PACKETBUF_ADDR_RECEIVER),
&linkaddr_node_addr) &&
!packetbuf_holds_broadcast()) {
LOG_WARN("not for us\n");
} else if(linkaddr_cmp(packetbuf_addr(PACKETBUF_ADDR_SENDER), &linkaddr_node_addr)) {
LOG_WARN("frame from ourselves\n");
} else {
int duplicate = 0;
/* Check for duplicate packet. */
duplicate = mac_sequence_is_duplicate();
if(duplicate) {
/* Drop the packet. */
LOG_WARN("drop duplicate link layer packet from ");
LOG_WARN_LLADDR(packetbuf_addr(PACKETBUF_ADDR_SENDER));
LOG_WARN_(", seqno %u\n", packetbuf_attr(PACKETBUF_ATTR_MAC_SEQNO));
} else {
mac_sequence_register_seqno();
}
#if CSMA_SEND_SOFT_ACK
if(packetbuf_attr(PACKETBUF_ATTR_MAC_ACK)) {
ackdata[0] = FRAME802154_ACKFRAME;
ackdata[1] = 0;
ackdata[2] = ((uint8_t *)packetbuf_hdrptr())[2];
NETSTACK_RADIO.send(ackdata, CSMA_ACK_LEN);
}
#endif /* CSMA_SEND_SOFT_ACK */
if(!duplicate) {
LOG_INFO("received packet from ");
LOG_INFO_LLADDR(packetbuf_addr(PACKETBUF_ADDR_SENDER));
LOG_INFO_(", seqno %u, len %u\n", packetbuf_attr(PACKETBUF_ATTR_MAC_SEQNO), packetbuf_datalen());
NETSTACK_NETWORK.input();
}
}
}
/*---------------------------------------------------------------------------*/
static int
on(void)
{
return NETSTACK_RADIO.on();
}
/*---------------------------------------------------------------------------*/
static int
off(void)
{
return NETSTACK_RADIO.off();
}
/*---------------------------------------------------------------------------*/
static void
init(void)
{
#if LLSEC802154_USES_AUX_HEADER
#ifdef CSMA_LLSEC_DEFAULT_KEY0
uint8_t key[16] = CSMA_LLSEC_DEFAULT_KEY0;
csma_security_set_key(0, key);
#endif
#endif /* LLSEC802154_USES_AUX_HEADER */
csma_output_init();
on();
}
/*---------------------------------------------------------------------------*/
static int
max_payload(void)
{
int framer_hdrlen;
init_sec();
framer_hdrlen = NETSTACK_FRAMER.length();
if(framer_hdrlen < 0) {
/* Framing failed, we assume the maximum header length */
framer_hdrlen = CSMA_MAC_MAX_HEADER;
}
return CSMA_MAC_LEN - framer_hdrlen;
}
/*---------------------------------------------------------------------------*/
const struct mac_driver csma_driver = {
"CSMA",
init,
send_packet,
input_packet,
on,
off,
max_payload,
};
/*---------------------------------------------------------------------------*/