packethandler/implementation/src/main/java/org/opendaylight/l2switch/packethandler/decoders/ArpDecoder.java

   1 package org.opendaylight.l2switch.packethandler.decoders;
   2
   3 import org.opendaylight.controller.sal.binding.api.NotificationProviderService;
   4 import org.opendaylight.controller.sal.packet.BitBufferHelper;
   5 import org.opendaylight.controller.sal.packet.BufferException;
   6 import org.opendaylight.controller.sal.utils.HexEncode;
   7 import org.opendaylight.controller.sal.utils.NetUtils;
   8 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.arp.rev140528.ArpPacketOverEthernetReceived;
   9 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.arp.rev140528.ArpPacketOverEthernetReceivedBuilder;
  10 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.arp.rev140528.KnownHardwareType;
  11 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.arp.rev140528.KnownOperation;
  12 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.arp.rev140528.arp.packet.over.ethernet.fields.ArpPacketBuilder;
  13 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.arp.rev140528.arp.packet.over.ethernet.fields.EthernetOverRawPacket;
  14 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.arp.rev140528.arp.packet.over.ethernet.fields.EthernetOverRawPacketBuilder;
  15 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.ethernet.rev140528.EthernetPacketListener;
  16 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.ethernet.rev140528.EthernetPacketOverRawReceived;
  17 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.ethernet.rev140528.KnownEtherType;
  18 import org.opendaylight.yangtools.yang.binding.NotificationListener;
  19 import org.slf4j.Logger;
  20 import org.slf4j.LoggerFactory;
  21
  22 import java.net.InetAddress;
  23 import java.net.UnknownHostException;
  24
  25 /**
  26  * ARP (Address Resolution Protocol) Packet Decoder
  27  */
  28 public class ArpDecoder extends AbstractPacketDecoder<EthernetPacketOverRawReceived, ArpPacketOverEthernetReceived>
  29     implements EthernetPacketListener {
  30
  31   private static final Logger _logger = LoggerFactory.getLogger(ArpDecoder.class);
  32
  33   public ArpDecoder(NotificationProviderService notificationProviderService) {
  34     super(ArpPacketOverEthernetReceived.class, notificationProviderService);
  35   }
  36
  37   /**
  38    * Decode an EthernetPacket into an ArpPacket
  39    */
  40   @Override
  41   public ArpPacketOverEthernetReceived decode(EthernetPacketOverRawReceived ethernetPacketOverRawReceived) {
  42     ArpPacketOverEthernetReceivedBuilder arpReceivedBuilder = new ArpPacketOverEthernetReceivedBuilder();
  43
  44     byte[] data = ethernetPacketOverRawReceived.getPayload();
  45     int bitOffset = ethernetPacketOverRawReceived.getEthernetPacket().getPayloadOffset() * NetUtils.NumBitsInAByte;
  46
  47     ArpPacketBuilder builder = new ArpPacketBuilder();
  48
  49     try {
  50       // Decode the hardware-type (HTYPE) and protocol-type (PTYPE) fields
  51       builder.setHardwareType(KnownHardwareType.forValue(BitBufferHelper.getInt(BitBufferHelper.getBits(data, bitOffset + 0, 16))));
  52       builder.setProtocolType(KnownEtherType.forValue(BitBufferHelper.getInt(BitBufferHelper.getBits(data, bitOffset+16, 16))));
  53
  54       // Decode the hardware-length and protocol-length fields
  55       builder.setHardwareLength(BitBufferHelper.getShort(BitBufferHelper.getBits(data, bitOffset+32, 8)));
  56       builder.setProtocolLength(BitBufferHelper.getShort(BitBufferHelper.getBits(data, bitOffset+40, 8)));
  57
  58       // Decode the operation field
  59       builder.setOperation(KnownOperation.forValue(BitBufferHelper.getInt(BitBufferHelper.getBits(data, bitOffset+48, 16))));
  60
  61       // Decode the address fields
  62       int indexSrcProtAdd = 64 + 8 * builder.getHardwareLength();
  63       int indexDstHardAdd = indexSrcProtAdd + 8 * builder.getProtocolLength();
  64       int indexDstProtAdd = indexDstHardAdd + 8 * builder.getHardwareLength();
  65       if(builder.getHardwareType().equals(KnownHardwareType.Ethernet)) {
  66         builder.setSourceHardwareAddress(HexEncode.bytesToHexStringFormat(BitBufferHelper.getBits(data, bitOffset + 64, 8 * builder.getHardwareLength())));
  67         builder.setDestinationHardwareAddress(HexEncode.bytesToHexStringFormat(BitBufferHelper.getBits(data, bitOffset + indexDstHardAdd, 8 * builder.getHardwareLength())));
  68       } else {
  69         _logger.debug("Unknown HardwareType -- sourceHardwareAddress and destinationHardwareAddress are not decoded");
  70       }
  71
  72       if(builder.getProtocolType().equals(KnownEtherType.Ipv4) || builder.getProtocolType().equals(KnownEtherType.Ipv6)) {
  73         builder.setSourceProtocolAddress(InetAddress.getByAddress(BitBufferHelper.getBits(data, bitOffset + indexSrcProtAdd, 8 * builder.getProtocolLength())).getHostAddress());
  74         builder.setDestinationProtocolAddress(InetAddress.getByAddress(BitBufferHelper.getBits(data, bitOffset + indexDstProtAdd, 8 * builder.getProtocolLength())).getHostAddress());
  75       } else {
  76         _logger.debug("Unknown ProtocolType -- sourceProtocolAddress and destinationProtocolAddress are not decoded");
  77       }
  78     } catch(BufferException | UnknownHostException e) {
  79       _logger.debug("Exception while decoding APR packet", e.getMessage());
  80     }
  81
  82     //build arp
  83     arpReceivedBuilder.setArpPacket(builder.build());
  84
  85     // extract ethernet over raw context from the consumed notification and set it and set it in Produced notification
  86     EthernetOverRawPacketBuilder ethernetOverRawPacketBuilder =  new EthernetOverRawPacketBuilder();
  87     ethernetOverRawPacketBuilder.setRawPacket(ethernetPacketOverRawReceived.getRawPacket());
  88     ethernetOverRawPacketBuilder.setEthernetPacket(ethernetPacketOverRawReceived.getEthernetPacket());
  89
  90     //set the context of previous decoded fields
  91     arpReceivedBuilder.setEthernetOverRawPacket(ethernetOverRawPacketBuilder.build());
  92
  93     // carry forward the original payload.
  94     arpReceivedBuilder.setPayload(ethernetPacketOverRawReceived.getPayload());
  95
  96     return arpReceivedBuilder.build();
  97   }
  98
  99   @Override
 100   public NotificationListener getConsumedNotificationListener() {
 101     return this;
 102   }
 103
 104   @Override
 105   public void onEthernetPacketOverRawReceived(EthernetPacketOverRawReceived notification) {
 106     decodeAndPublish(notification);
 107   }
 108
 109   @Override
 110   public boolean canDecode(EthernetPacketOverRawReceived ethernetPacketOverRawReceived) {
 111     if(ethernetPacketOverRawReceived==null || ethernetPacketOverRawReceived.getEthernetPacket()==null)
 112       return false;
 113     return KnownEtherType.Arp.equals(ethernetPacketOverRawReceived.getEthernetPacket().getEthertype());
 114   }
 115 }