This post originated from an RSS feed registered with Java Buzz by Wilfred Springer. Original Post: Getting the Ethernet Frame Feed Title: Distributed Reflections of the Third Kind Feed URL: http://blog.flotsam.nl/feeds/posts/default/-/Java Feed Description: Anything coming to my mind having to do with Java Latest Java Buzz Posts Latest Java Buzz Posts by Wilfred Springer Latest Posts From Distributed Reflections of the Third Kind

@Slice(size="(packetRecordLength - 24) * 8")
@BoundList(size="includedLength")
private byte[] packetData;

@Slice(size = "(packetRecordLength - 24) * 8")
@BoundObject(selectFrom = @Choices(alternatives =
 @Choice(condition = "outer.header.datalinkType==DatalinkType.ETHERNET", type = EthernetFrame.class))
)
private Object packetData;

public static class EthernetFrame {

   @BoundList(size = "6")
   private byte[] destinationAddress;
  
   @BoundList(size = "6")
   private byte[] sourceAddress;

   @BoundNumber(size = "16")
   private int type;

   @BoundList(size="outer.includedLength - (6 + 6 + 2)")
   private byte[] data;

}

public class SnoopFile {

@Bound
private FileHeader header;

@BoundList(type = PacketRecord.class)
private List<PacketRecord> records;

public FileHeader getHeader() {
 return header;
}

public List<PacketRecord> getRecords() {
 return records;
}

public static class FileHeader {

 @BoundBuffer(match = { 0x73, 0x6e, 0x6f, 0x6f, 0x70, 0x00, 0x00, 0x00 })
 private byte[] identificationPattern;

 @BoundNumber(byteOrder = ByteOrder.BigEndian)
 private int versionNumber;

 @BoundNumber(size = "32", byteOrder = ByteOrder.BigEndian)
 private DatalinkType datalinkType;

 public int getVersionNumber() {
  return versionNumber;
 }

 public DatalinkType getDatalinkType() {
  return datalinkType;
 }

}

@ImportStatic(DatalinkType.class)
public static class PacketRecord {

 @BoundNumber(byteOrder = ByteOrder.BigEndian, size = "32")
 private long originalLength;

 @BoundNumber(byteOrder = ByteOrder.BigEndian, size = "32")
 private long includedLength;

 @BoundNumber(byteOrder = ByteOrder.BigEndian, size = "32")
 private long packetRecordLength;

 @BoundNumber(byteOrder = ByteOrder.BigEndian, size = "32")
 private long cumulativeDrops;

 @BoundNumber(byteOrder = ByteOrder.BigEndian, size = "32")
 private long timestampSeconds;

 @BoundNumber(byteOrder = ByteOrder.BigEndian, size = "32")
 private long timestampMicroseconds;

 @Slice(size = "(packetRecordLength - 24) * 8")
 @BoundObject(selectFrom = @Choices(alternatives = @Choice(condition = "outer.header.datalinkType==DatalinkType.ETHERNET", type = EthernetFrame.class)))
 private Object packetData;

 public long getOriginalLength() {
  return originalLength;
 }

 public long getIncludedLength() {
  return includedLength;
 }

 public long getPacketRecordLength() {
  return packetRecordLength;
 }

 public long getCumulativeDrops() {
  return cumulativeDrops;
 }

 public long getTimestampSeconds() {
  return timestampSeconds;
 }

 public long getTimestampMicroseconds() {
  return timestampMicroseconds;
 }

 public Object getPacketData() {
  return packetData;
 }

 public static class EthernetFrame {

  @BoundList(size = "6")
  private byte[] destinationAddress;

  @BoundList(size = "6")
  private byte[] sourceAddress;

  @BoundNumber(size = "16")
  private int type;

  @BoundList(size="outer.includedLength - (6 + 6 + 2)")
  private byte[] data;

  public String getDestinationAddress() {
   return render(destinationAddress);
  }
 
  public String getSourceAddress() {
   return render(sourceAddress);
  }
 
  private String render(byte[] address) {
   StringBuilder builder = new StringBuilder();
   for (int i = 0; i < address.length; i++) {
    if (i != 0) {
     builder.append(':');
    }
    builder.append(Integer.toHexString(0xff&address[i]));
   }
   return builder.toString();
  }

 }

}

public static enum DatalinkType {

 @BoundEnumOption(0)
 IEEE_802_3,

 @BoundEnumOption(1)
 IEEE_802_4_TOKEN_BUS,

 @BoundEnumOption(2)
 IEEE_802_5_TOKEN_RING,

 @BoundEnumOption(3)
 IEEE_802_6_METRO_NET,

 @BoundEnumOption(4)
 ETHERNET,

 @BoundEnumOption(5)
 HLDC,

 @BoundEnumOption(6)
 CHARACTER_SYNCHRONOUS,

 @BoundEnumOption(7)
 IBM_CHANNEL_TO_CHANNEL,

 @BoundEnumOption(8)
 FDDI,

 @BoundEnumOption(9)
 OTHER,

 UNASSIGNED
}

}