Add crc to packets send by coojamote

This commit is contained in:
Laurent Deru 2015-06-12 12:59:51 +02:00
parent e762d7eb50
commit 6891ca12b0
2 changed files with 101 additions and 3 deletions

View file

@ -48,7 +48,7 @@ import org.contikios.cooja.interfaces.Position;
import org.contikios.cooja.interfaces.Radio;
import org.contikios.cooja.mote.memory.VarMemory;
import org.contikios.cooja.radiomediums.UDGM;
import org.contikios.cooja.util.CCITT_CRC;
/**
* Packet radio transceiver mote interface.
*
@ -200,7 +200,7 @@ public class ContikiRadio extends Radio implements ContikiMoteInterface, PolledA
packetToMote = null;
myMoteMemory.setIntValueOf("simInSize", 0);
} else {
myMoteMemory.setIntValueOf("simInSize", packetToMote.getPacketData().length);
myMoteMemory.setIntValueOf("simInSize", packetToMote.getPacketData().length - 2);
myMoteMemory.setByteArray("simInDataBuffer", packetToMote.getPacketData());
}
@ -330,7 +330,7 @@ public class ContikiRadio extends Radio implements ContikiMoteInterface, PolledA
/* New transmission */
int size = myMoteMemory.getIntValueOf("simOutSize");
if (!isTransmitting && size > 0) {
packetFromMote = new COOJARadioPacket(myMoteMemory.getByteArray("simOutDataBuffer", size));
packetFromMote = new COOJARadioPacket(myMoteMemory.getByteArray("simOutDataBuffer", size + 2));
if (packetFromMote.getPacketData() == null || packetFromMote.getPacketData().length == 0) {
logger.warn("Skipping zero sized Contiki packet (no buffer)");
@ -339,6 +339,15 @@ public class ContikiRadio extends Radio implements ContikiMoteInterface, PolledA
return;
}
byte[] data = packetFromMote.getPacketData();
CCITT_CRC txCrc = new CCITT_CRC();
txCrc.setCRC(0);
for (int i = 0; i < size; i++) {
txCrc.addBitrev(data[i]);
}
data[size] = (byte)txCrc.getCRCHi();
data[size + 1] = (byte)txCrc.getCRCLow();
isTransmitting = true;
/* Calculate transmission duration (us) */

View file

@ -0,0 +1,89 @@
/**
* Copyright (c) 2008, 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 MSPSim.
*
* -----------------------------------------------------------------
*
* Author : Joakim Eriksson
*/
package org.contikios.cooja.util;
/* basic CRC-CCITT code */
public class CCITT_CRC {
int crc;
public int getCRC() {
return crc;
}
/* this will only work with zero... */
public void setCRC(int val) {
crc = val;
}
public void clr() {
crc = 0xffff;
}
public void addBitrev(int data) {
add(bitrev(data));
}
public int getCRCLow() {
return bitrev(crc & 0xff);
}
public int getCRCHi() {
return bitrev(crc >> 8);
}
public int add(int data) {
int newCrc = ((crc >> 8) & 0xff) | (crc << 8) & 0xffff;
newCrc ^= (data & 0xff);
newCrc ^= (newCrc & 0xff) >> 4;
newCrc ^= (newCrc << 12) & 0xffff;
newCrc ^= (newCrc & 0xff) << 5;
crc = newCrc & 0xffff;
return crc;
}
public int getCRCBitrev() {
return getCRCLow() + (getCRCHi() << 8);
}
public static final String hex = "0123456789abcdef";
private static int bitrev(int data) {
return ((data << 7) & 0x80) | ((data << 5) & 0x40) |
(data << 3) & 0x20 | (data << 1) & 0x10 |
(data >> 7) & 0x01 | (data >> 5) & 0x02 |
(data >> 3) & 0x04 | (data >> 1) & 0x08;
}
}