contiki/core/net/mac/contikimac.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: contikimac.c,v 1.2 2010/02/18 21:48:39 adamdunkels Exp $
 */

/**
 * \file
 *         The Contiki power-saving MAC protocol (ContikiMAC)
 * \author
 *         Adam Dunkels <adam@sics.se>
 *         Niclas Finne <nfi@sics.se>
 *         Joakim Eriksson <joakime@sics.se>
 */

#include <io.h>

#include "net/netstack.h"
#include "dev/leds.h"
#include "dev/radio.h"
#include "dev/watchdog.h"
#include "lib/random.h"
#include "net/mac/framer.h"
#include "net/mac/contikimac.h"
#include "net/rime.h"
#include "sys/compower.h"
#include "sys/pt.h"
#include "sys/rtimer.h"

#include "contiki-conf.h"

#ifdef EXPERIMENT_SETUP
#include "experiment-setup.h"
#endif

#include <string.h>

#ifndef WITH_ACK_OPTIMIZATION
#define WITH_ACK_OPTIMIZATION        1
#endif
#ifndef WITH_PHASE_OPTIMIZATION
#define WITH_PHASE_OPTIMIZATION      1
#endif
#ifndef WITH_STREAMING
#define WITH_STREAMING               1
#endif

struct announcement_data {
  uint16_t id;
  uint16_t value;
};

/* The maximum number of announcements in a single announcement
   message - may need to be increased in the future. */
#define ANNOUNCEMENT_MAX 10

/* The structure of the announcement messages. */
struct announcement_msg {
  uint16_t num;
  struct announcement_data data[ANNOUNCEMENT_MAX];
};

/* The length of the header of the announcement message, i.e., the
   "num" field in the struct. */
#define ANNOUNCEMENT_MSG_HEADERLEN (sizeof (uint16_t))

#define DISPATCH          0
#define TYPE_ANNOUNCEMENT 0x12

struct contikimac_hdr {
  uint8_t dispatch;
  uint8_t type;
};

#ifdef CONTIKIMAC_CONF_CYCLE_TIME
#define CYCLE_TIME (CONTIKIMAC_CONF_CYCLE_TIME)
#else
#define CYCLE_TIME (RTIMER_ARCH_SECOND / MAC_CHANNEL_CHECK_RATE)
#endif

#define CCA_COUNT_MAX 2
#define CCA_CHECK_TIME (RTIMER_ARCH_SECOND / 8192)
#define CCA_SLEEP_TIME (RTIMER_ARCH_SECOND / 1500)
#define CHECK_TIME (CCA_COUNT_MAX * (CCA_CHECK_TIME + CCA_SLEEP_TIME))

#define LISTEN_TIME (RTIMER_ARCH_SECOND / 150)

#define WAIT_TIME_BEFORE_STROBE_ACK_CCA RTIMER_ARCH_SECOND / 3000
#define WAIT_TIME_AFTER_STROBE_ACK_CCA  RTIMER_ARCH_SECOND / 2000

/* The cycle time for announcements. */
#define ANNOUNCEMENT_PERIOD 4 * CLOCK_SECOND

/* The time before sending an announcement within one announcement
   cycle. */
#define ANNOUNCEMENT_TIME (random_rand() % (ANNOUNCEMENT_PERIOD))

#define STROBE_WAIT_TIME (RTIMER_ARCH_SECOND / 600)

#define STROBE_TIME (CYCLE_TIME + 8 * CHECK_TIME)

#define ACK_LEN 3

#include <stdio.h>
static struct rtimer rt;
static struct pt pt;

static volatile uint8_t contikimac_is_on = 0;

static volatile unsigned char we_are_sending = 0;
static volatile unsigned char radio_is_on = 0;

#undef LEDS_ON
#undef LEDS_OFF
#undef LEDS_TOGGLE

#define LEDS_ON(x) leds_on(x)
#define LEDS_OFF(x) leds_off(x)
#define LEDS_TOGGLE(x) leds_toggle(x)
#define DEBUG 0
#if DEBUG
#include <stdio.h>
#define PRINTF(...) printf(__VA_ARGS__)
#define PRINTDEBUG(...) printf(__VA_ARGS__)
#else
#undef LEDS_ON
#undef LEDS_OFF
#undef LEDS_TOGGLE
#define LEDS_ON(x)
#define LEDS_OFF(x)
#define LEDS_TOGGLE(x)
#define PRINTF(...)
#define PRINTDEBUG(...)
#endif

#if CONTIKIMAC_CONF_ANNOUNCEMENTS
/* Timers for keeping track of when to send announcements. */
static struct ctimer announcement_cycle_ctimer, announcement_ctimer;

static int announcement_radio_txpower;
#endif /* CONTIKIMAC_CONF_ANNOUNCEMENTS */

/* Flag that is used to keep track of whether or not we are listening
   for announcements from neighbors. */
static uint8_t is_listening;

#if CONTIKIMAC_CONF_COMPOWER
static struct compower_activity current_packet;
#endif /* CONTIKIMAC_CONF_COMPOWER */

#if WITH_PHASE_OPTIMIZATION

#include "net/mac/phase.h"

#define MAX_PHASE_NEIGHBORS 4

PHASE_LIST(phase_list, MAX_PHASE_NEIGHBORS);

#endif /* WITH_PHASE_OPTIMIZATION */

static uint8_t is_streaming;
static rimeaddr_t is_streaming_to, is_streaming_to_too;
static rtimer_clock_t stream_until;

#define DEFAULT_STREAM_TIME (RTIMER_ARCH_SECOND)

#ifndef MIN
#define MIN(a, b) ((a) < (b)? (a) : (b))
#endif /* MIN */

/*---------------------------------------------------------------------------*/
static void
on(void)
{
  if(contikimac_is_on && radio_is_on == 0) {
    radio_is_on = 1;
    NETSTACK_RADIO.on();
    LEDS_ON(LEDS_RED);
  }
}
/*---------------------------------------------------------------------------*/
static void
off(void)
{
  if(contikimac_is_on && radio_is_on != 0 && is_listening == 0 && is_streaming == 0) {
    radio_is_on = 0;
    NETSTACK_RADIO.off();
    LEDS_OFF(LEDS_RED);
  }
}
/*---------------------------------------------------------------------------*/
static char powercycle(struct rtimer *t, void *ptr);
static void
schedule_powercycle(struct rtimer *t, rtimer_clock_t time)
{
  int r;

  if(contikimac_is_on) {
#if NURTIMER
    r = rtimer_reschedule(t, time, 1);
#else
    r = rtimer_set(t, RTIMER_TIME(t) + time, 1,
                   (void (*)(struct rtimer *, void *))powercycle, NULL);
#endif
    if(r != RTIMER_OK) {
      printf("schedule_powercycle: could not set rtimer\n");
    }
  }
}
static void
powercycle_turn_radio_off(void)
{
  if(we_are_sending == 0) {
    off();
  }
#if CONTIKIMAC_CONF_COMPOWER
  compower_accumulate(&compower_idle_activity);
#endif /* CONTIKIMAC_CONF_COMPOWER */
}
static void
powercycle_turn_radio_on(void)
{
  if(we_are_sending == 0) {
    on();
  }
}
static char
powercycle(struct rtimer *t, void *ptr)
{
  rtimer_clock_t start;

  if(is_streaming) {
    start = RTIMER_NOW();
#if NURTIMER
    if(!RTIMER_CLOCK_LT(start, RTIMER_NOW(), stream_until))
#else
    if(!RTIMER_CLOCK_LT(RTIMER_NOW(), stream_until))
#endif
    {
      is_streaming = 0;
      rimeaddr_copy(&is_streaming_to, &rimeaddr_null);
      rimeaddr_copy(&is_streaming_to_too, &rimeaddr_null);
    }
  }
  
  PT_BEGIN(&pt);

  while(1) {
    static uint8_t packet_seen;
    static rtimer_clock_t t0, cycle_start;
    static uint8_t count;

    cycle_start = RTIMER_NOW();

    packet_seen = 0;
    if(we_are_sending == 0) {
      for(count = 0; count < CCA_COUNT_MAX; ++count) {
        t0 = RTIMER_NOW();
        powercycle_turn_radio_on();
#if NURTIMER
        while(RTIMER_CLOCK_LT(t0, RTIMER_NOW(), t0 + CCA_CHECK_TIME));
#else
        while(RTIMER_CLOCK_LT(RTIMER_NOW(), t0 + CCA_CHECK_TIME));
#endif
        if(NETSTACK_RADIO.channel_clear() == 0) {
          packet_seen = 1;
          break;
        }
        powercycle_turn_radio_off();
        schedule_powercycle(t, CCA_SLEEP_TIME + CCA_CHECK_TIME);
        PT_YIELD(&pt);
      }

      /* If there were a packet in the air, turn radio on */
      if(packet_seen) {
        schedule_powercycle(t, LISTEN_TIME);
        PT_YIELD(&pt);
        powercycle_turn_radio_off();
      }
    }
    if(RTIMER_NOW() - cycle_start < CYCLE_TIME) {
      schedule_powercycle(t, CYCLE_TIME - (RTIMER_NOW() - cycle_start));
      PT_YIELD(&pt);
    }
  }

  PT_END(&pt);
}
/*---------------------------------------------------------------------------*/
#if CONTIKIMAC_CONF_ANNOUNCEMENTS
static int
parse_announcements(const rimeaddr_t * from)
{
  /* Parse incoming announcements */
  struct announcement_msg adata;
  int i;

  memcpy(&adata, packetbuf_dataptr(),
         MIN(packetbuf_datalen(), sizeof(adata)));

  /*  printf("%d.%d: probe from %d.%d with %d announcements\n",
     rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1],
     from->u8[0], from->u8[1], adata->num); */
  /*  for(i = 0; i < packetbuf_datalen(); ++i) {
     printf("%02x ", ((uint8_t *)packetbuf_dataptr())[i]);
     }
     printf("\n"); */

  for(i = 0; i < adata.num; ++i) {
    /*   printf("%d.%d: announcement %d: %d\n",
       rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1],
       adata->data[i].id,
       adata->data[i].value); */

    announcement_heard(from, adata.data[i].id, adata.data[i].value);
  }
  return i;
}
/*---------------------------------------------------------------------------*/
static int
format_announcement(char *hdr)
{
  struct announcement_msg adata;
  struct announcement *a;

  /* Construct the announcements */
  /*  adata = (struct announcement_msg *)hdr; */

  adata.num = 0;
  for(a = announcement_list();
      a != NULL && adata.num < ANNOUNCEMENT_MAX; a = a->next) {
    adata.data[adata.num].id = a->id;
    adata.data[adata.num].value = a->value;
    adata.num++;
  }

  memcpy(hdr, &adata, sizeof(struct announcement_msg));

  if(adata.num > 0) {
    return ANNOUNCEMENT_MSG_HEADERLEN +
      sizeof(struct announcement_data) * adata.num;
  } else {
    return 0;
  }
}
#endif /* CONTIKIMAC_CONF_ANNOUNCEMENTS */
/*---------------------------------------------------------------------------*/
static int
send_packet(void)
{
  rtimer_clock_t t0;
  rtimer_clock_t t;
  rtimer_clock_t encounter_time = 0;
  int strobes;
  int got_strobe_ack = 0;
  int len;
  int is_broadcast = 0;
  int is_reliable = 0;
  uint8_t collisions;
  int transmit_len;
  int i;

  /* Create the X-MAC header for the data packet. */
  packetbuf_set_addr(PACKETBUF_ADDR_SENDER, &rimeaddr_node_addr);
  if(rimeaddr_cmp(packetbuf_addr(PACKETBUF_ADDR_RECEIVER), &rimeaddr_null)) {
    is_broadcast = 1;
    PRINTDEBUG("contikimac: send broadcast\n");
  } else {
#if UIP_CONF_IPV6
    PRINTDEBUG("contikimac: send unicast to %02x%02x:%02x%02x:%02x%02x:%02x%02x\n",
               packetbuf_addr(PACKETBUF_ADDR_RECEIVER)->u8[0],
               packetbuf_addr(PACKETBUF_ADDR_RECEIVER)->u8[1],
               packetbuf_addr(PACKETBUF_ADDR_RECEIVER)->u8[2],
               packetbuf_addr(PACKETBUF_ADDR_RECEIVER)->u8[3],
               packetbuf_addr(PACKETBUF_ADDR_RECEIVER)->u8[4],
               packetbuf_addr(PACKETBUF_ADDR_RECEIVER)->u8[5],
               packetbuf_addr(PACKETBUF_ADDR_RECEIVER)->u8[6],
               packetbuf_addr(PACKETBUF_ADDR_RECEIVER)->u8[7]);
#else
    PRINTDEBUG("contikimac: send unicast to %u.%u\n",
               packetbuf_addr(PACKETBUF_ADDR_RECEIVER)->u8[0],
               packetbuf_addr(PACKETBUF_ADDR_RECEIVER)->u8[1]);
#endif /* UIP_CONF_IPV6 */
  }
  is_reliable = packetbuf_attr(PACKETBUF_ATTR_RELIABLE) ||
    packetbuf_attr(PACKETBUF_ATTR_ERELIABLE);
  len = framer_get()->create();
  if(len == 0) {
    /* Failed to send */
    PRINTF("contikimac: send failed, too large header\n");
    return MAC_TX_ERR_FATAL;
  }

  packetbuf_compact();

  NETSTACK_RADIO.prepare(packetbuf_hdrptr(), packetbuf_totlen());
  transmit_len = packetbuf_totlen();

  
#if WITH_STREAMING
  if(packetbuf_attr(PACKETBUF_ATTR_PACKET_TYPE) ==
     PACKETBUF_ATTR_PACKET_TYPE_STREAM) {
    is_streaming = 1;
    if(rimeaddr_cmp(&is_streaming_to, &rimeaddr_null)) {
      rimeaddr_copy(&is_streaming_to,
                    packetbuf_addr(PACKETBUF_ADDR_RECEIVER));
    } else
      if(!rimeaddr_cmp
         (&is_streaming_to, packetbuf_addr(PACKETBUF_ADDR_RECEIVER))) {
      rimeaddr_copy(&is_streaming_to_too,
                    packetbuf_addr(PACKETBUF_ADDR_RECEIVER));
    }
    stream_until = RTIMER_NOW() + DEFAULT_STREAM_TIME;
  }
#endif /* WITH_STREAMING */


#if WITH_PHASE_OPTIMIZATION
#if WITH_ACK_OPTIMIZATION
  /* Wait until the receiver is expected to be awake */
  if(packetbuf_attr(PACKETBUF_ATTR_PACKET_TYPE) !=
     PACKETBUF_ATTR_PACKET_TYPE_ACK && is_streaming == 0) {

    phase_wait(&phase_list, packetbuf_addr(PACKETBUF_ADDR_RECEIVER),
               CYCLE_TIME, 5 * CHECK_TIME);
  }
#else /* WITH_ACK_OPTIMIZATION */
  phase_wait(&phase_list, packetbuf_addr(PACKETBUF_ADDR_RECEIVER),
             CYCLE_TIME, 5 * CHECK_TIME);
#endif /* WITH_ACK_OPTIMIZATION */
#endif /* WITH_PHASE_OPTIMIZATION */

    leds_on(LEDS_GREEN);
  /* By setting we_are_sending to one, we ensure that the rtimer
     powercycle interrupt do not interfere with us sending the packet. */
  we_are_sending = 1;

  /* If we have a pending packet in the radio, we should not send now,
     because we will trash the received packet. Instead, we signal
     that we have a collision, which lets the packet be received. This
     packet will be retransmitted later by the MAC protocol
     instread. */
  if(NETSTACK_RADIO.receiving_packet() || NETSTACK_RADIO.pending_packet()) {
    leds_off(LEDS_GREEN);
    we_are_sending = 0;
    return MAC_TX_COLLISION;
  }
  
  /* Switch off the radio to ensure that we didn't start sending while
     the radio was doing a channel check. */
  off();


  strobes = 0;

  LEDS_ON(LEDS_BLUE);

  /* Send a train of strobes until the receiver answers with an ACK. */
  collisions = 0;

  got_strobe_ack = 0;

  leds_off(LEDS_GREEN);

  if(packetbuf_attr(PACKETBUF_ATTR_PACKET_TYPE) !=
     PACKETBUF_ATTR_PACKET_TYPE_ACK && is_streaming == 0) {
    /* Check if there are any transmissions by others. */
    for(i = 0; i < CCA_COUNT_MAX; ++i) {
      t0 = RTIMER_NOW();
      on();
#if NURTIMER
      while(RTIMER_CLOCK_LT(t0, RTIMER_NOW(), t0 + CCA_CHECK_TIME));
#else
      while(RTIMER_CLOCK_LT(RTIMER_NOW(), t0 + CCA_CHECK_TIME)) { }
#endif
      if(NETSTACK_RADIO.channel_clear() == 0) {
        collisions++;
        off();
        break;
      }
      off();
#if NURTIMER
      while(RTIMER_CLOCK_LT(t0, RTIMER_NOW(), t0 + CCA_SLEEP_TIME + CCA_CHECK_TIME));
#else
      while(RTIMER_CLOCK_LT(RTIMER_NOW(), t0 + CCA_SLEEP_TIME + CCA_CHECK_TIME)) { }
#endif
    }
  }

  if(collisions > 0) {
    we_are_sending = 0;
    return MAC_TX_COLLISION;
  }

  t0 = RTIMER_NOW();
  t = RTIMER_NOW();
#if NURTIMER
  for(strobes = 0, collisions = 0;
      got_strobe_ack == 0 && collisions == 0 &&
      RTIMER_CLOCK_LT(t0, RTIMER_NOW(), t0 + STROBE_TIME); strobes++) {
#else
  for(strobes = 0, collisions = 0;
      got_strobe_ack == 0 && collisions == 0 &&
      RTIMER_CLOCK_LT(RTIMER_NOW(), t0 + STROBE_TIME); strobes++) {
#endif

    /* Let the watchdog know we are still alive. */
    watchdog_periodic();
    
    len = 0;

    t = RTIMER_NOW();
    
    
    /*if(is_broadcast) {
      NETSTACK_RADIO.transmit(transmit_len);
      off();b
      } else*/ {
      rtimer_clock_t wt;
      rtimer_clock_t now = RTIMER_NOW();
      
      NETSTACK_RADIO.transmit(transmit_len);
      if(!is_broadcast) {
        on();
      }
      /* Turn off the radio for a while to let the other side
         respond. We don't need to keep our radio on when we know
         that the other side needs some time to produce a reply. */
      wt = RTIMER_NOW();
#if NURTIMER
      while(RTIMER_CLOCK_LT
            (wt, RTIMER_NOW(), wt + WAIT_TIME_BEFORE_STROBE_ACK_CCA));
#else
      while(RTIMER_CLOCK_LT
            (RTIMER_NOW(), wt + WAIT_TIME_BEFORE_STROBE_ACK_CCA)) { }
#endif
      leds_on(LEDS_RED);
      if(!is_broadcast && !NETSTACK_RADIO.channel_clear()) {
        uint8_t ackbuf[ACK_LEN];
        leds_on(LEDS_BLUE);
        wt = RTIMER_NOW();
#if NURTIMER
        while(RTIMER_CLOCK_LT
              (wt, RTIMER_NOW(), wt + WAIT_TIME_AFTER_STROBE_ACK_CCA));
#else
        while(RTIMER_CLOCK_LT
              (RTIMER_NOW(), wt + WAIT_TIME_AFTER_STROBE_ACK_CCA)) { }
#endif
        leds_off(LEDS_BLUE);
        if(!is_broadcast) {
          len = NETSTACK_RADIO.read(ackbuf, ACK_LEN);
          if(len == ACK_LEN) {
            got_strobe_ack = 1;
            encounter_time = now;
          } else {
            collisions++;
          }
        } else {
        }
      }
      leds_off(LEDS_RED);
    }
  }

#if WITH_ACK_OPTIMIZATION
  /* If we have received the strobe ACK, and we are sending a packet
     that will need an upper layer ACK (as signified by the
     PACKETBUF_ATTR_RELIABLE packet attribute), we keep the radio on. */
  if(got_strobe_ack && is_reliable) {
    on();                       /* Wait for ACK packet */
  } else {
    off();
  }
#else /* WITH_ACK_OPTIMIZATION */
  off();
#endif /* WITH_ACK_OPTIMIZATION */

#if WITH_PHASE_OPTIMIZATION
  if(got_strobe_ack && packetbuf_attr(PACKETBUF_ATTR_PACKET_TYPE) !=
     PACKETBUF_ATTR_PACKET_TYPE_ACK && is_streaming == 0) {
    phase_register(&phase_list, packetbuf_addr(PACKETBUF_ADDR_RECEIVER), encounter_time);
  }
#endif /* WITH_PHASE_OPTIMIZATION */

  PRINTF("contikimac: send (strobes=%u,len=%u,%s), done\n", strobes,
         packetbuf_totlen(), got_strobe_ack ? "ack" : "no ack");

#if CONTIKIMAC_CONF_COMPOWER
  /* Accumulate the power consumption for the packet transmission. */
  compower_accumulate(&current_packet);

  /* Convert the accumulated power consumption for the transmitted
     packet to packet attributes so that the higher levels can keep
     track of the amount of energy spent on transmitting the
     packet. */
  compower_attrconv(&current_packet);

  /* Clear the accumulated power consumption so that it is ready for
     the next packet. */
  compower_clear(&current_packet);
#endif /* CONTIKIMAC_CONF_COMPOWER */

  we_are_sending = 0;

  LEDS_OFF(LEDS_BLUE);
  if(collisions == 0) {
    if(!is_broadcast && !got_strobe_ack) {
      return MAC_TX_NOACK;
    } else {
      return MAC_TX_OK;
    }
  } else {
    return MAC_TX_COLLISION;
  }

}
/*---------------------------------------------------------------------------*/
static void
qsend_packet(mac_callback_t sent, void *ptr)
{
  int ret = send_packet();
  mac_call_sent_callback(sent, ptr, ret, 1);
}
/*---------------------------------------------------------------------------*/
static void
input_packet(void)
{
  struct contikimac_hdr *hdr;

  /* We have received the packet, so we can go back to being
     asleep. */
  off();

  if(framer_get()->parse()) {
    hdr = packetbuf_dataptr();

    if(hdr->dispatch != DISPATCH) {
      if(rimeaddr_cmp(packetbuf_addr(PACKETBUF_ADDR_RECEIVER),
                      &rimeaddr_node_addr) ||
         rimeaddr_cmp(packetbuf_addr(PACKETBUF_ADDR_RECEIVER),
                      &rimeaddr_null)) {
        /* This is a regular packet that is destined to us or to the
           broadcast address. */


#if CONTIKIMAC_CONF_COMPOWER
        /* Accumulate the power consumption for the packet reception. */
        compower_accumulate(&current_packet);
        /* Convert the accumulated power consumption for the received
           packet to packet attributes so that the higher levels can
           keep track of the amount of energy spent on receiving the
           packet. */
        compower_attrconv(&current_packet);

        /* Clear the accumulated power consumption so that it is ready
           for the next packet. */
        compower_clear(&current_packet);
#endif /* CONTIKIMAC_CONF_COMPOWER */

        PRINTDEBUG("contikimac: data(%u)\n", packetbuf_datalen());

        NETSTACK_MAC.input();
        return;
      } else {
        PRINTDEBUG("contikimac: data not for us\n");
      }
#if CONTIKIMAC_CONF_ANNOUNCEMENTS
    } else if(hdr->type == TYPE_ANNOUNCEMENT) {
      packetbuf_hdrreduce(sizeof(struct contikimac_hdr));
      parse_announcements(packetbuf_addr(PACKETBUF_ADDR_SENDER));
#endif /* CONTIKIMAC_CONF_ANNOUNCEMENTS */
    } else {
      PRINTF("contikimac: unknown type %u (%u/%u)\n", hdr->type,
             packetbuf_datalen(), len);
    }
  } else {
    PRINTF("contikimac: failed to parse (%u)\n", packetbuf_totlen());
  }
}
/*---------------------------------------------------------------------------*/
#if CONTIKIMAC_CONF_ANNOUNCEMENTS
static void
send_announcement(void *ptr)
{
  struct contikimac_hdr *hdr;
  int announcement_len;

  /* Set up the probe header. */
  packetbuf_clear();
  hdr = packetbuf_dataptr();

  announcement_len = format_announcement((char *)hdr +
                                         sizeof(struct contikimac_hdr));

  if(announcement_len > 0) {
    packetbuf_set_datalen(sizeof(struct contikimac_hdr) + announcement_len);
    hdr->dispatch = DISPATCH;
    hdr->type = TYPE_ANNOUNCEMENT;

    packetbuf_set_addr(PACKETBUF_ADDR_SENDER, &rimeaddr_node_addr);
    packetbuf_set_addr(PACKETBUF_ADDR_RECEIVER, &rimeaddr_null);
    packetbuf_set_attr(PACKETBUF_ATTR_RADIO_TXPOWER,
                       announcement_radio_txpower);
    if(framer_get()->create()) {
      we_are_sending = 1;
      NETSTACK_RADIO.send(packetbuf_hdrptr(), packetbuf_totlen());
      we_are_sending = 0;
    }
  }
}
/*---------------------------------------------------------------------------*/
static void
cycle_announcement(void *ptr)
{
  ctimer_set(&announcement_ctimer, ANNOUNCEMENT_TIME,
             send_announcement, NULL);
  ctimer_set(&announcement_cycle_ctimer, ANNOUNCEMENT_PERIOD,
             cycle_announcement, NULL);
  if(is_listening > 0) {
    is_listening--;
    /*    printf("is_listening %d\n", is_listening); */
  }
}
/*---------------------------------------------------------------------------*/
static void
listen_callback(int periods)
{
  is_listening = periods + 1;
}
#endif /* CONTIKIMAC_CONF_ANNOUNCEMENTS */
/*---------------------------------------------------------------------------*/
void
contikimac_set_announcement_radio_txpower(int txpower)
{
#if CONTIKIMAC_CONF_ANNOUNCEMENTS
  announcement_radio_txpower = txpower;
#endif /* CONTIKIMAC_CONF_ANNOUNCEMENTS */
}
/*---------------------------------------------------------------------------*/
static void
init(void)
{
  radio_is_on = 0;
  PT_INIT(&pt);
#if NURTIMER
  rtimer_setup(&rt, RTIMER_HARD,
               (void (*)(struct rtimer *, void *, int status))powercycle,
               NULL);
  rtimer_schedule(&rt, CYCLE_TIME, 1);
#else
  rtimer_set(&rt, RTIMER_NOW() + CYCLE_TIME, 1,
             (void (*)(struct rtimer *, void *))powercycle, NULL);
#endif

  contikimac_is_on = 1;

#if WITH_PHASE_OPTIMIZATION
  phase_init(&phase_list);
#endif /* WITH_PHASE_OPTIMIZATION */

#if CONTIKIMAC_CONF_ANNOUNCEMENTS
  announcement_register_listen_callback(listen_callback);
  ctimer_set(&announcement_cycle_ctimer, ANNOUNCEMENT_TIME,
             cycle_announcement, NULL);
#endif /* CONTIKIMAC_CONF_ANNOUNCEMENTS */
}
/*---------------------------------------------------------------------------*/
static int
turn_on(void)
{
  contikimac_is_on = 1;
#if NURTIMER
  rtimer_schedule(&rt, CYCLE_TIME, 1);
#else
  rtimer_set(&rt, RTIMER_NOW() + CYCLE_TIME, 1,
             (void (*)(struct rtimer *, void *))powercycle, NULL);
#endif

  return 1;
}
/*---------------------------------------------------------------------------*/
static int
turn_off(int keep_radio_on)
{
  contikimac_is_on = 0;
  if(keep_radio_on) {
    return NETSTACK_RADIO.on();
  } else {
    return NETSTACK_RADIO.off();
  }
}
/*---------------------------------------------------------------------------*/
static unsigned short
duty_cycle(void)
{
  return (1ul * CLOCK_SECOND * CYCLE_TIME) / RTIMER_ARCH_SECOND;
}
/*---------------------------------------------------------------------------*/
const struct mac_driver contikimac_driver = {
  "ContikiMAC",
  init,
  qsend_packet,
  input_packet,
  turn_on,
  turn_off,
  duty_cycle,
};