packethandler/implementation/src/main/java/org/opendaylight/l2switch/packethandler/decoders/Ipv6Decoder.java

   1 /*
   2  * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.l2switch.packethandler.decoders;
   9
  10 import java.net.InetAddress;
  11 import java.net.UnknownHostException;
  12 import java.util.ArrayList;
  13 import java.util.Arrays;
  14 import java.util.List;
  15
  16 import org.opendaylight.controller.sal.binding.api.NotificationProviderService;
  17 import org.opendaylight.l2switch.packethandler.decoders.utils.BitBufferHelper;
  18 import org.opendaylight.l2switch.packethandler.decoders.utils.BufferException;
  19 import org.opendaylight.l2switch.packethandler.decoders.utils.NetUtils;
  20 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev100924.Dscp;
  21 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev100924.Ipv6Address;
  22 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.basepacket.rev140528.packet.chain.grp.PacketChain;
  23 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.basepacket.rev140528.packet.chain.grp.PacketChainBuilder;
  24 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.basepacket.rev140528.packet.chain.grp.packet.chain.Packet;
  25 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.ethernet.rev140528.EthernetPacketListener;
  26 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.ethernet.rev140528.EthernetPacketReceived;
  27 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.ethernet.rev140528.KnownEtherType;
  28 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.ethernet.rev140528.ethernet.packet.received.packet.chain.packet.EthernetPacket;
  29 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.ipv4.rev140528.KnownIpProtocols;
  30 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.ipv6.rev140528.Ipv6PacketReceived;
  31 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.ipv6.rev140528.Ipv6PacketReceivedBuilder;
  32 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.ipv6.rev140528.ipv6.packet.fields.ExtensionHeaders;
  33 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.ipv6.rev140528.ipv6.packet.fields.ExtensionHeadersBuilder;
  34 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.ipv6.rev140528.ipv6.packet.received.packet.chain.packet.Ipv6PacketBuilder;
  35 import org.opendaylight.yangtools.yang.binding.NotificationListener;
  36 import org.slf4j.Logger;
  37 import org.slf4j.LoggerFactory;
  38
  39 /**
  40  * IPv6 Packet Decoder
  41  */
  42 public class Ipv6Decoder extends AbstractPacketDecoder<EthernetPacketReceived, Ipv6PacketReceived>
  43         implements EthernetPacketListener {
  44
  45     private static final Logger LOG = LoggerFactory.getLogger(Ipv6Decoder.class);
  46
  47     public Ipv6Decoder(NotificationProviderService notificationProviderService) {
  48         super(Ipv6PacketReceived.class, notificationProviderService);
  49     }
  50
  51     /**
  52      * Decode an EthernetPacket into an Ipv4Packet
  53      */
  54     @Override
  55     public Ipv6PacketReceived decode(EthernetPacketReceived ethernetPacketReceived) {
  56         Ipv6PacketReceivedBuilder ipv6ReceivedBuilder = new Ipv6PacketReceivedBuilder();
  57
  58         // Find the latest packet in the packet-chain, which is an
  59         // EthernetPacket
  60         List<PacketChain> packetChainList = ethernetPacketReceived.getPacketChain();
  61         EthernetPacket ethernetPacket = (EthernetPacket) packetChainList.get(packetChainList.size() - 1).getPacket();
  62         int bitOffset = ethernetPacket.getPayloadOffset() * NetUtils.NumBitsInAByte;
  63         byte[] data = ethernetPacketReceived.getPayload();
  64
  65         Ipv6PacketBuilder builder = new Ipv6PacketBuilder();
  66         try {
  67             builder.setVersion(BitBufferHelper.getShort(BitBufferHelper.getBits(data, bitOffset, 4)));
  68             if (builder.getVersion().intValue() != 6) {
  69                 LOG.debug("Version should be 6, but is {}", builder.getVersion());
  70             }
  71
  72             builder.setDscp(new Dscp(BitBufferHelper.getShort(BitBufferHelper.getBits(data, bitOffset + 4, 6))));
  73             builder.setEcn(BitBufferHelper.getShort(BitBufferHelper.getBits(data, bitOffset + 10, 2)));
  74             builder.setFlowLabel(BitBufferHelper.getLong(BitBufferHelper.getBits(data, bitOffset + 12, 20)));
  75             builder.setIpv6Length(BitBufferHelper.getInt(BitBufferHelper.getBits(data, bitOffset + 32, 16)));
  76             builder.setNextHeader(KnownIpProtocols
  77                     .forValue(BitBufferHelper.getInt(BitBufferHelper.getBits(data, bitOffset + 48, 8))));
  78             builder.setHopLimit(BitBufferHelper.getShort(BitBufferHelper.getBits(data, bitOffset + 56, 8)));
  79             builder.setSourceIpv6(Ipv6Address.getDefaultInstance(
  80                     InetAddress.getByAddress(BitBufferHelper.getBits(data, bitOffset + 64, 128)).getHostAddress()));
  81             builder.setDestinationIpv6(Ipv6Address.getDefaultInstance(
  82                     InetAddress.getByAddress(BitBufferHelper.getBits(data, bitOffset + 192, 128)).getHostAddress()));
  83             builder.setPayloadOffset((320 + bitOffset) / NetUtils.NumBitsInAByte);
  84             builder.setPayloadLength(builder.getIpv6Length());
  85
  86             // Decode the optional "extension headers"
  87             List<ExtensionHeaders> extensionHeaders = new ArrayList<ExtensionHeaders>();
  88             KnownIpProtocols nextHeader = builder.getNextHeader();
  89             int extHeaderOffset = 0;
  90             while (nextHeader != null && !nextHeader.equals(KnownIpProtocols.Tcp)
  91                     && !nextHeader.equals(KnownIpProtocols.Udp)) {
  92                 // Set the extension header's type & length & data
  93                 short nextHeaderType = BitBufferHelper
  94                         .getShort(BitBufferHelper.getBits(data, 320 + extHeaderOffset + bitOffset, 8));
  95                 nextHeader = KnownIpProtocols.forValue(nextHeaderType);
  96                 int octetLength = BitBufferHelper
  97                         .getInt(BitBufferHelper.getBits(data, 328 + extHeaderOffset + bitOffset, 8));
  98                 int start = (336 + extHeaderOffset + bitOffset) / NetUtils.NumBitsInAByte;
  99                 int end = start + 6 + octetLength;
 100
 101                 extensionHeaders.add(new ExtensionHeadersBuilder().setNextHeader(nextHeader).setLength(octetLength)
 102                         .setData(Arrays.copyOfRange(data, start, end)).build());
 103
 104                 // Update the NextHeader field
 105                 extHeaderOffset += 64 + octetLength * NetUtils.NumBitsInAByte;
 106             }
 107             if (!extensionHeaders.isEmpty()) {
 108                 builder.setExtensionHeaders(extensionHeaders);
 109             }
 110         } catch (BufferException | UnknownHostException e) {
 111             LOG.debug("Exception while decoding IPv4 packet", e.getMessage());
 112         }
 113
 114         // build ipv6
 115         packetChainList.add(new PacketChainBuilder().setPacket(builder.build()).build());
 116         ipv6ReceivedBuilder.setPacketChain(packetChainList);
 117
 118         // carry forward the original payload.
 119         ipv6ReceivedBuilder.setPayload(ethernetPacketReceived.getPayload());
 120
 121         return ipv6ReceivedBuilder.build();
 122     }
 123
 124     @Override
 125     public NotificationListener getConsumedNotificationListener() {
 126         return this;
 127     }
 128
 129     @Override
 130     public void onEthernetPacketReceived(EthernetPacketReceived notification) {
 131         decodeAndPublish(notification);
 132     }
 133
 134     @Override
 135     public boolean canDecode(EthernetPacketReceived ethernetPacketReceived) {
 136         if (ethernetPacketReceived == null || ethernetPacketReceived.getPacketChain() == null)
 137             return false;
 138
 139         // Only decode the latest packet in the chain
 140         EthernetPacket ethernetPacket = null;
 141         if (!ethernetPacketReceived.getPacketChain().isEmpty()) {
 142             Packet packet = ethernetPacketReceived.getPacketChain()
 143                     .get(ethernetPacketReceived.getPacketChain().size() - 1).getPacket();
 144             if (packet instanceof EthernetPacket) {
 145                 ethernetPacket = (EthernetPacket) packet;
 146             }
 147         }
 148
 149         return ethernetPacket != null && KnownEtherType.Ipv6.equals(ethernetPacket.getEthertype());
 150     }
 151 }