Example #1
0
/*---------------------------------------------------------------------------*/
static int
send_packet(void)
{
  rtimer_clock_t t0;
  rtimer_clock_t t;
  rtimer_clock_t encounter_time = 0;
  int strobes;
  int ret;
#if 0
  struct xmac_hdr *hdr;
#endif
  uint8_t got_strobe_ack = 0;
  uint8_t got_ack = 0;
  uint8_t strobe[MAX_STROBE_SIZE];
  int strobe_len, len;
  int is_broadcast = 0;
/*int is_reliable; */
  struct encounter *e;
  struct queuebuf *packet;
  int is_already_streaming = 0;
  uint8_t collisions;

  /* 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("xmac: send broadcast\n");
  } else {
#if UIP_CONF_IPV6
    PRINTDEBUG("xmac: 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("xmac: 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); */

  packetbuf_set_attr(PACKETBUF_ATTR_MAC_ACK, 1);
  len = NETSTACK_FRAMER.create();
  strobe_len = len + sizeof(struct xmac_hdr);
  if(len < 0 || strobe_len > (int)sizeof(strobe)) {
    /* Failed to send */
   PRINTF("xmac: send failed, too large header\n");
    return MAC_TX_ERR_FATAL;
  }
  memcpy(strobe, packetbuf_hdrptr(), len);
  strobe[len] = DISPATCH; /* dispatch */
  strobe[len + 1] = TYPE_STROBE; /* type */

  packetbuf_compact();
  packet = queuebuf_new_from_packetbuf();
  if(packet == NULL) {
    /* No buffer available */
    PRINTF("xmac: send failed, no queue buffer available (of %u)\n",
           QUEUEBUF_CONF_NUM);
    return MAC_TX_ERR;
  }

#if WITH_STREAMING
  if(is_streaming == 1 &&
     (rimeaddr_cmp(packetbuf_addr(PACKETBUF_ADDR_RECEIVER),
		   &is_streaming_to) ||
      rimeaddr_cmp(packetbuf_addr(PACKETBUF_ADDR_RECEIVER),
		   &is_streaming_to_too))) {
    is_already_streaming = 1;
  }
  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 */

  off();

#if WITH_ENCOUNTER_OPTIMIZATION
  /* We go through the list of encounters to find if we have recorded
     an encounter with this particular neighbor. If so, we can compute
     the time for the next expected encounter and setup a ctimer to
     switch on the radio just before the encounter. */
  for(e = list_head(encounter_list); e != NULL; e = list_item_next(e)) {
    const rimeaddr_t *neighbor = packetbuf_addr(PACKETBUF_ADDR_RECEIVER);

    if(rimeaddr_cmp(neighbor, &e->neighbor)) {
      rtimer_clock_t wait, now, expected;

      /* We expect encounters to happen every DEFAULT_PERIOD time
	 units. The next expected encounter is at time e->time +
	 DEFAULT_PERIOD. To compute a relative offset, we subtract
	 with clock_time(). Because we are only interested in turning
	 on the radio within the DEFAULT_PERIOD period, we compute the
	 waiting time with modulo DEFAULT_PERIOD. */

      now = RTIMER_NOW();
      wait = ((rtimer_clock_t)(e->time - now)) % (DEFAULT_PERIOD);
      if(wait < 2 * DEFAULT_ON_TIME) {
        wait = DEFAULT_PERIOD;
      }
      expected = now + wait - 2 * DEFAULT_ON_TIME;

#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) {
	/* Do not wait if we are sending an ACK, because then the
	   receiver will already be awake. */
	while(RTIMER_CLOCK_LT(RTIMER_NOW(), expected));
      }
#else /* WITH_ACK_OPTIMIZATION */
      /* Wait until the receiver is expected to be awake */
      while(RTIMER_CLOCK_LT(RTIMER_NOW(), expected));
#endif /* WITH_ACK_OPTIMIZATION */
    }
  }
#endif /* WITH_ENCOUNTER_OPTIMIZATION */

  /* 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;
  
  t0 = RTIMER_NOW();
  strobes = 0;

  LEDS_ON(LEDS_BLUE);

  /* Send a train of strobes until the receiver answers with an ACK. */

  /* Turn on the radio to listen for the strobe ACK. */
  //  on();
  collisions = 0;
  if(!is_already_streaming) {
    watchdog_stop();
    got_strobe_ack = 0;
    t = RTIMER_NOW();
    for(strobes = 0, collisions = 0;
	got_strobe_ack == 0 && collisions == 0 &&
	  RTIMER_CLOCK_LT(RTIMER_NOW(), t0 + xmac_config.strobe_time);
	strobes++) {

      while(got_strobe_ack == 0 &&
	    RTIMER_CLOCK_LT(RTIMER_NOW(), t + xmac_config.strobe_wait_time)) {
#if 0
	rtimer_clock_t now = RTIMER_NOW();

	/* See if we got an ACK */
	packetbuf_clear();
	len = NETSTACK_RADIO.read(packetbuf_dataptr(), PACKETBUF_SIZE);
	if(len > 0) {
	  packetbuf_set_datalen(len);
	  if(NETSTACK_FRAMER.parse() >= 0) {
	    hdr = packetbuf_dataptr();
	    if(hdr->dispatch == DISPATCH && hdr->type == TYPE_STROBE_ACK) {
	      if(rimeaddr_cmp(packetbuf_addr(PACKETBUF_ADDR_RECEIVER),
			      &rimeaddr_node_addr)) {
		/* We got an ACK from the receiver, so we can immediately send
		   the packet. */
		got_strobe_ack = 1;
		encounter_time = now;
	      } else {
		PRINTDEBUG("xmac: strobe ack for someone else\n");
	      }
	    } else /*if(hdr->dispatch == DISPATCH && hdr->type == TYPE_STROBE)*/ {
	      PRINTDEBUG("xmac: strobe from someone else\n");
	      collisions++;
	    }
	  } else {
	    PRINTF("xmac: send failed to parse %u\n", len);
	  }
	}
#endif /* 0 */
      }
      
      t = RTIMER_NOW();
            /* Send the strobe packet. */
      if(got_strobe_ack == 0 && collisions == 0) {

	if(is_broadcast) {
#if WITH_STROBE_BROADCAST
	  ret = NETSTACK_RADIO.send(strobe, strobe_len);
#else
	  /* restore the packet to send */
	  queuebuf_to_packetbuf(packet);
	  ret = NETSTACK_RADIO.send(packetbuf_hdrptr(), packetbuf_totlen());
#endif
          off();
	} else {
#if 0
	  rtimer_clock_t wt;
#endif
          on();
	  ret = NETSTACK_RADIO.send(strobe, strobe_len);
#if 0
	  /* 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. */
	  off();
	  wt = RTIMER_NOW();
	  while(RTIMER_CLOCK_LT(RTIMER_NOW(), wt + WAIT_TIME_BEFORE_STROBE_ACK));
#endif /* 0 */
#if RDC_CONF_HARDWARE_ACK
          if(ret == RADIO_TX_OK) {
            got_strobe_ack = 1;
          } else {
            off();
          }
#else
          if(detect_ack()) {
            got_strobe_ack = 1;
          } else {
            off();
          }
#endif /* RDC_CONF_HARDWARE_ACK */

        }
      }
    }
  }

#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 && (packetbuf_attr(PACKETBUF_ATTR_RELIABLE) ||
			packetbuf_attr(PACKETBUF_ATTR_ERELIABLE) ||
			packetbuf_attr(PACKETBUF_ATTR_PACKET_TYPE) ==
			PACKETBUF_ATTR_PACKET_TYPE_STREAM)) {
    on(); /* Wait for ACK packet */
    waiting_for_packet = 1;
  } else {
    off();
  }
#endif /* WITH_ACK_OPTIMIZATION */

  /* restore the packet to send */
  queuebuf_to_packetbuf(packet);
  queuebuf_free(packet);

  /* Send the data packet. */
  if((is_broadcast || got_strobe_ack || is_streaming) && collisions == 0) {
    ret = NETSTACK_RADIO.send(packetbuf_hdrptr(), packetbuf_totlen());

    if(!is_broadcast) {
#if RDC_CONF_HARDWARE_ACK
      if(ret == RADIO_TX_OK) {
        got_ack = 1;
      }
#else
      if(detect_ack()) {
        got_ack = 1;
      }
#endif /* RDC_CONF_HARDWARE_ACK */
    }
  }
  off();

#if WITH_ENCOUNTER_OPTIMIZATION
  if(got_strobe_ack && !is_streaming) {
    register_encounter(packetbuf_addr(PACKETBUF_ADDR_RECEIVER), encounter_time);
  }
#endif /* WITH_ENCOUNTER_OPTIMIZATION */
  watchdog_start();

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

#if XMAC_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 /* XMAC_CONF_COMPOWER */

  we_are_sending = 0;

  LEDS_OFF(LEDS_BLUE);
  if(collisions == 0) {
    if(is_broadcast == 0 && got_ack == 0) {
      return MAC_TX_NOACK;
    } else {
      return MAC_TX_OK;
    }
  } else {
    someone_is_sending++;
    return MAC_TX_COLLISION;
  }

}
Example #2
0
/**
 * Read a packet from the underlying radio driver. If the incoming
 * packet is a probe packet and the sender of the probe matches the
 * destination address of the queued packet (if any), the queued packet
 * is sent.
 */
static void
input_packet(void)
{
  struct lpp_hdr hdr;
  clock_time_t reception_time;

  reception_time = clock_time();

  if(!NETSTACK_FRAMER.parse()) {
    printf("lpp input_packet framer error\n");
  }

  memcpy(&hdr, packetbuf_dataptr(), sizeof(struct lpp_hdr));;
  packetbuf_hdrreduce(sizeof(struct lpp_hdr));
  /*    PRINTF("got packet type %d\n", hdr->type);*/

  if(hdr.type == TYPE_PROBE) {
    struct announcement_msg adata;
    
    /* Register the encounter with the sending node. We now know the
       neighbor's phase. */
    register_encounter(&hdr.sender, reception_time);

    /* Parse incoming announcements */
    memcpy(&adata, packetbuf_dataptr(),
           MIN(packetbuf_datalen(), sizeof(adata)));
#if 0
    PRINTF("%d.%d: probe from %d.%d with %d announcements\n",
           rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1],
           hdr.sender.u8[0], hdr.sender.u8[1], adata->num);
    
    if(adata.num / sizeof(struct announcement_data) > sizeof(struct announcement_msg)) {
      /* Sanity check. The number of announcements is too large -
         corrupt packet has been received. */
      return 0;
    }

    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(&hdr.sender,
                         adata.data[i].id,
                         adata.data[i].value);
    }
#endif  /* 0 */

    /* Go through the list of packets to be sent to see if any of
       them match the sender of the probe, or if they are a
       broadcast packet that should be sent. */
    if(list_length(queued_packets_list) > 0) {
      struct queue_list_item *i;
      for(i = list_head(queued_packets_list); i != NULL; i = list_item_next(i)) {
        const rimeaddr_t *receiver;
        uint8_t sent;

        sent = 0;
 
        receiver = queuebuf_addr(i->packet, PACKETBUF_ADDR_RECEIVER);
        if(rimeaddr_cmp(receiver, &hdr.sender) ||
           rimeaddr_cmp(receiver, &rimeaddr_null)) {
          queuebuf_to_packetbuf(i->packet);

#if WITH_PENDING_BROADCAST
          if(i->broadcast_flag == BROADCAST_FLAG_NONE ||
             i->broadcast_flag == BROADCAST_FLAG_SEND) {
            i->num_transmissions = 1;
            NETSTACK_RADIO.send(queuebuf_dataptr(i->packet),
                                queuebuf_datalen(i->packet));
            sent = 1;
            PRINTF("%d.%d: got a probe from %d.%d, sent packet to %d.%d\n",
		   rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1],
                   hdr.sender.u8[0], hdr.sender.u8[1],
                   receiver->u8[0], receiver->u8[1]);
	      
          } else {
            PRINTF("%d.%d: got a probe from %d.%d, did not send packet\n",
                   rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1],
                   hdr.sender.u8[0], hdr.sender.u8[1]);
          }
#else /* WITH_PENDING_BROADCAST */
          i->num_transmissions = 1;
          NETSTACK_RADIO.send(queuebuf_dataptr(i->packet),
                               queuebuf_datalen(i->packet));
          PRINTF("%d.%d: got a probe from %d.%d, sent packet to %d.%d\n",
                 rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1],
                 hdr.sender.u8[0], hdr.sender.u8[1],
                 receiver->u8[0], receiver->u8[1]);
#endif /* WITH_PENDING_BROADCAST */

          /*          off();*/

          /* Attribute the energy spent on listening for the probe
             to this packet transmission. */
          compower_accumulate(&i->compower);
	    
          /* If the packet was not a broadcast packet, we dequeue it
             now. Broadcast packets should be transmitted to all
             neighbors, and are dequeued by the dutycycling function
             instead, after the appropriate time. */
          if(!rimeaddr_cmp(receiver, &rimeaddr_null)) {
            if(detect_ack()) {
              remove_queued_packet(i, 1);
            } else {
              remove_queued_packet(i, 0);
            }

#if WITH_PROBE_AFTER_TRANSMISSION
            /* Send a probe packet to catch any reply from the other node. */
            restart_dutycycle(PROBE_AFTER_TRANSMISSION_TIME);
#endif /* WITH_PROBE_AFTER_TRANSMISSION */

#if WITH_STREAMING
            if(is_streaming) {
              ctimer_set(&stream_probe_timer, STREAM_PROBE_TIME,
                         send_stream_probe, NULL);
            }
#endif /* WITH_STREAMING */
          }

          if(sent) {
            turn_radio_off();
          }

#if WITH_ACK_OPTIMIZATION
          if(packetbuf_attr(PACKETBUF_ATTR_RELIABLE) ||
             packetbuf_attr(PACKETBUF_ATTR_ERELIABLE)) {
            /* We're sending a packet that needs an ACK, so we keep
               the radio on in anticipation of the ACK. */
            turn_radio_on();
          }
#endif /* WITH_ACK_OPTIMIZATION */

        }
      }
    }

  } else if(hdr.type == TYPE_DATA) {
    turn_radio_off();
    if(!rimeaddr_cmp(&hdr.receiver, &rimeaddr_null)) {
      if(!rimeaddr_cmp(&hdr.receiver, &rimeaddr_node_addr)) {
        /* Not broadcast or for us */
        PRINTF("%d.%d: data not for us from %d.%d\n",
               rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1],
               hdr.sender.u8[0], hdr.sender.u8[1]);
        return;
      }
      packetbuf_set_addr(PACKETBUF_ADDR_RECEIVER, &hdr.receiver);
    }
    packetbuf_set_addr(PACKETBUF_ADDR_SENDER, &hdr.sender);

    PRINTF("%d.%d: got data from %d.%d\n",
           rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1],
           hdr.sender.u8[0], hdr.sender.u8[1]);

    /* 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);

#if WITH_PENDING_BROADCAST
    if(rimeaddr_cmp(&hdr.receiver, &rimeaddr_null)) {
      /* This is a broadcast packet. Check the list of pending
         packets to see if we are currently sending a broadcast. If
         so, we refrain from sending our broadcast until one sleep
         cycle period, so that the other broadcaster will have
         finished sending. */
	
      struct queue_list_item *i;
      for(i = list_head(queued_packets_list); i != NULL; i = list_item_next(i)) {
        /* If the packet is a broadcast packet that is not yet
           ready to be sent, we do not send it. */
        if(i->broadcast_flag == BROADCAST_FLAG_PENDING) {
          PRINTF("Someone else is sending, pending -> waiting\n");
          set_broadcast_flag(i, BROADCAST_FLAG_WAITING);
        }
      }
    }
#endif /* WITH_PENDING_BROADCAST */


#if WITH_PROBE_AFTER_RECEPTION
    /* XXX send probe after receiving a packet to facilitate data
       streaming. We must first copy the contents of the packetbuf into
       a queuebuf to avoid overwriting the data with the probe packet. */
    if(rimeaddr_cmp(&hdr.receiver, &rimeaddr_node_addr)) {
      struct queuebuf *q;
      q = queuebuf_new_from_packetbuf();
      if(q != NULL) {
        send_probe();
        queuebuf_to_packetbuf(q);
        queuebuf_free(q);
      }
    }
#endif /* WITH_PROBE_AFTER_RECEPTION */

#if WITH_ADAPTIVE_OFF_TIME
    off_time = LOWEST_OFF_TIME;
    restart_dutycycle(off_time);
#endif /* WITH_ADAPTIVE_OFF_TIME */

    NETSTACK_MAC.input();
  }
}