From 6ae7fc99a199e94142ff481c0707a3bb4d9cbd1d Mon Sep 17 00:00:00 2001 From: fros4943 Date: Wed, 29 Oct 2008 18:28:16 +0000 Subject: [PATCH] packet converter with x-mac and crc support --- .../CC2420RadioPacketConverter.java | 163 +++++++++++++++--- 1 file changed, 135 insertions(+), 28 deletions(-) diff --git a/tools/cooja/apps/mspsim/src/se/sics/cooja/mspmote/interfaces/CC2420RadioPacketConverter.java b/tools/cooja/apps/mspsim/src/se/sics/cooja/mspmote/interfaces/CC2420RadioPacketConverter.java index b99e900b6..5ae8e6c8b 100644 --- a/tools/cooja/apps/mspsim/src/se/sics/cooja/mspmote/interfaces/CC2420RadioPacketConverter.java +++ b/tools/cooja/apps/mspsim/src/se/sics/cooja/mspmote/interfaces/CC2420RadioPacketConverter.java @@ -26,7 +26,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * - * $Id: CC2420RadioPacketConverter.java,v 1.3 2008/06/27 14:11:52 nifi Exp $ + * $Id: CC2420RadioPacketConverter.java,v 1.4 2008/10/29 18:28:16 fros4943 Exp $ */ package se.sics.cooja.mspmote.interfaces; @@ -34,44 +34,151 @@ package se.sics.cooja.mspmote.interfaces; import org.apache.log4j.Logger; import se.sics.cooja.COOJARadioPacket; -import se.sics.cooja.RadioPacket; /** - * Converts radio packets between CC24240/Sky and COOJA. + * Converts radio packets between X-MAC/CC24240/Sky and COOJA. * Handles radio driver specifics such as length header and CRC footer. * - * @author Fredrik Osterlind + * @author Fredrik Österlind */ public class CC2420RadioPacketConverter { private static Logger logger = Logger.getLogger(CC2420RadioPacketConverter.class); - /* CC2420/802.15.4 packet: PREAMBLE(4) _ SYNCH(2) _ LENGTH(1) _ PAYLOAD(<27) _ CRCFOOTER(2) */ + public static final boolean WITH_PREAMBLE = true; + public static final boolean WITH_SYNCH = true; + public static final boolean WITH_XMAC = true; + public static final boolean WITH_CHECKSUM = true; + public static final boolean WITH_TIMESTAMP = true; + public static final boolean WITH_FOOTER = true; - /** - * Converts a COOJA radio packet to a CC2420 radio packet. - * - * @param coojaPacket COOJA radio packet - * @return CC2420 radio packet - */ - public static CC2420RadioPacket fromCoojaToCC24240(RadioPacket coojaPacket) { - byte[] data = coojaPacket.getPacketData(); - byte[] cc2420Data = new byte[data.length + 3]; - cc2420Data[0] = (byte) ((data.length + 2) & 0xff); - System.arraycopy(data, 0, cc2420Data, 1, data.length); - return new CC2420RadioPacket(cc2420Data); + public static byte[] fromCoojaToCC24240(COOJARadioPacket packet) { + byte cc2420Data[] = new byte[6+127]; + int pos = 0; + byte packetData[] = packet.getPacketData(); + byte len; /* total packet minus preamble(4), synch(1) and length(1) */ + short accumulatedCRC = 0; + + /* 4 bytes preamble */ + if (WITH_PREAMBLE) { + cc2420Data[pos++] = 0; + cc2420Data[pos++] = 0; + cc2420Data[pos++] = 0; + cc2420Data[pos++] = 0; + } + + /* 1 byte synch */ + if (WITH_SYNCH) { + cc2420Data[pos++] = 0x7A; + } + + /* 1 byte length */ + len = (byte) packetData.length; + if (WITH_XMAC) { + len += 4; + } + if (WITH_CHECKSUM) { + len += 2; + } + if (WITH_TIMESTAMP) { + len += 3; + } + if (WITH_FOOTER) { + len += 2; + } + cc2420Data[pos++] = len; + + /* (TODO) 4 byte X-MAC */ + if (WITH_XMAC) { + cc2420Data[pos++] = 0; + accumulatedCRC = CRCCoder.crc16Add((byte)0, accumulatedCRC); + cc2420Data[pos++] = 0; + accumulatedCRC = CRCCoder.crc16Add((byte)0, accumulatedCRC); + cc2420Data[pos++] = 0; + accumulatedCRC = CRCCoder.crc16Add((byte)0, accumulatedCRC); + cc2420Data[pos++] = 0; + accumulatedCRC = CRCCoder.crc16Add((byte)0, accumulatedCRC); + } + + /* Payload */ + for (byte b : packetData) { + accumulatedCRC = CRCCoder.crc16Add(b, accumulatedCRC); + } + System.arraycopy(packetData, 0, cc2420Data, pos, packetData.length); + pos += packetData.length; + + /* 2 bytes checksum */ + if (WITH_CHECKSUM) { + cc2420Data[pos++] = (byte) (accumulatedCRC & 0xff); + cc2420Data[pos++] = (byte) ((accumulatedCRC >> 8) & 0xff); + } + + /* (TODO) 3 bytes timestamp */ + if (WITH_TIMESTAMP) { + cc2420Data[pos++] = 0; + cc2420Data[pos++] = 0; + cc2420Data[pos++] = 0; + } + + /* (TODO) 2 bytes footer */ + if (WITH_FOOTER) { + cc2420Data[pos++] = 0; /* RSSI */ + cc2420Data[pos++] = (byte) 0x80; /* CRC and CORRELATION */ + } + + byte cc2420DataStripped[] = new byte[pos]; + System.arraycopy(cc2420Data, 0, cc2420DataStripped, 0, pos); + + /*logger.info("Data length: " + cc2420DataStripped.length);*/ + return cc2420DataStripped; } - /** - * Converts a CC2420 radio packet to a COOJA radio packet. - * - * @param cc2420RadioPacket CC24240 radio packet - * @return COOJA radio packet - */ - public static COOJARadioPacket fromCC2420ToCooja(CC2420RadioPacket cc2420RadioPacket) { - byte[] cc2420Data = cc2420RadioPacket.getPacketData(); - byte[] data = new byte[cc2420Data.length - 3]; - System.arraycopy(cc2420Data, 1, data, 0, data.length); - return new COOJARadioPacket(data); + public static COOJARadioPacket fromCC2420ToCooja(byte[] data) { + int pos = 0; + int len; /* Payload */ + + /* Use some CC2420/MAC specific field such as X-MAC response */ + + /* (IGNORED) 4 bytes preamble */ + if (WITH_PREAMBLE) { + pos += 4; + } + + /* (IGNORED) 1 byte synch */ + if (WITH_SYNCH) { + pos += 1; + } + + /* 1 byte length */ + len = data[pos]; + pos += 1; + + /* (IGNORED) 4 byte X-MAC */ + if (WITH_XMAC) { + pos += 4; + len -= 4; + } + + /* (IGNORED) 2 bytes checksum */ + if (WITH_CHECKSUM) { + len -= 2; + } + + /* (IGNORED) 3 bytes timestamp */ + if (WITH_TIMESTAMP) { + len -= 3; + } + + /* (IGNORED) 2 bytes footer */ + if (WITH_FOOTER) { + len -= 2; + } + + /*logger.info("Payload pos: " + pos); + logger.info("Payload length: " + len);*/ + + byte coojaData[] = new byte[len]; + System.arraycopy(data, pos, coojaData, 0, len); + return new COOJARadioPacket(coojaData); } }