packethandler/implementation/src/main/java/org/opendaylight/l2switch/packethandler/decoders/EthernetDecoder.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.util.ArrayList;
  11 import org.opendaylight.l2switch.packethandler.decoders.utils.BitBufferHelper;
  12 import org.opendaylight.l2switch.packethandler.decoders.utils.BufferException;
  13 import org.opendaylight.l2switch.packethandler.decoders.utils.HexEncode;
  14 import org.opendaylight.l2switch.packethandler.decoders.utils.NetUtils;
  15 import org.opendaylight.mdsal.binding.api.NotificationPublishService;
  16 import org.opendaylight.mdsal.binding.api.NotificationService;
  17 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.yang.types.rev130715.MacAddress;
  18 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.basepacket.rev140528.packet.chain.grp.PacketChain;
  19 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.basepacket.rev140528.packet.chain.grp.PacketChainBuilder;
  20 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.basepacket.rev140528.packet.chain.grp.packet.chain.packet.RawPacketBuilder;
  21 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.basepacket.rev140528.packet.chain.grp.packet.chain.packet.raw.packet.RawPacketFieldsBuilder;
  22 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.basepacket.rev140528.packet.chain.grp.packet.chain.packet.raw.packet.raw.packet.fields.MatchBuilder;
  23 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.ethernet.rev140528.EthernetPacketReceived;
  24 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.ethernet.rev140528.EthernetPacketReceivedBuilder;
  25 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.ethernet.rev140528.Header8021qType;
  26 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.ethernet.rev140528.KnownEtherType;
  27 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.ethernet.rev140528.VlanId;
  28 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.ethernet.rev140528.ethernet.packet.fields.Header8021q;
  29 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.ethernet.rev140528.ethernet.packet.fields.Header8021qBuilder;
  30 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.ethernet.rev140528.ethernet.packet.received.packet.chain.packet.EthernetPacketBuilder;
  31 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.service.rev130709.PacketProcessingListener;
  32 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.service.rev130709.PacketReceived;
  33 import org.opendaylight.yangtools.yang.binding.NotificationListener;
  34 import org.slf4j.Logger;
  35 import org.slf4j.LoggerFactory;
  36
  37 /**
  38  * Ethernet Packet Decoder.
  39  */
  40 public class EthernetDecoder extends AbstractPacketDecoder<PacketReceived, EthernetPacketReceived>
  41         implements PacketProcessingListener {
  42     private static final Logger LOG = LoggerFactory.getLogger(EthernetDecoder.class);
  43     public static final Integer LENGTH_MAX = 1500;
  44     public static final Integer ETHERTYPE_MIN = 1536;
  45     public static final Integer ETHERTYPE_8021Q = 0x8100;
  46     public static final Integer ETHERTYPE_QINQ = 0x9100;
  47
  48     public EthernetDecoder(NotificationPublishService notificationProviderService,
  49                            NotificationService notificationService) {
  50         super(EthernetPacketReceived.class, notificationProviderService, notificationService);
  51     }
  52
  53     @Override
  54     public void onPacketReceived(PacketReceived packetReceived) {
  55         decodeAndPublish(packetReceived);
  56     }
  57
  58     /**
  59      * Decode a RawPacket into an EthernetPacket.
  60      *
  61      * @param packetReceived
  62      *            -- data from wire to deserialize
  63      * @return EthernetPacketReceived
  64      */
  65     @Override
  66     public EthernetPacketReceived decode(PacketReceived packetReceived) {
  67         byte[] data = packetReceived.getPayload();
  68         EthernetPacketReceivedBuilder builder = new EthernetPacketReceivedBuilder();
  69
  70         // Save original rawPacket & set the payloadOffset/payloadLength fields
  71         RawPacketFieldsBuilder rpfb = new RawPacketFieldsBuilder().setIngress(packetReceived.getIngress())
  72                 .setConnectionCookie(packetReceived.getConnectionCookie()).setFlowCookie(packetReceived.getFlowCookie())
  73                 .setTableId(packetReceived.getTableId()).setPacketInReason(packetReceived.getPacketInReason())
  74                 .setPayloadOffset(0).setPayloadLength(data.length);
  75         if (packetReceived.getMatch() != null) {
  76             rpfb.setMatch(new MatchBuilder(packetReceived.getMatch()).build());
  77         }
  78         ArrayList<PacketChain> packetChain = new ArrayList<>();
  79         packetChain.add(new PacketChainBuilder()
  80             .setPacket(new RawPacketBuilder().setRawPacketFields(rpfb.build()).build())
  81             .build());
  82
  83         try {
  84             EthernetPacketBuilder epBuilder = new EthernetPacketBuilder();
  85
  86             // Deserialize the destination & source fields
  87             epBuilder.setDestinationMac(
  88                 new MacAddress(HexEncode.bytesToHexStringFormat(BitBufferHelper.getBits(data, 0, 48))));
  89             epBuilder.setSourceMac(
  90                 new MacAddress(HexEncode.bytesToHexStringFormat(BitBufferHelper.getBits(data, 48, 48))));
  91
  92             // Deserialize the optional field 802.1Q headers
  93             Integer nextField = BitBufferHelper.getInt(BitBufferHelper.getBits(data, 96, 16));
  94             int extraHeaderBits = 0;
  95             ArrayList<Header8021q> headerList = new ArrayList<>();
  96             while (nextField.equals(ETHERTYPE_8021Q) || nextField.equals(ETHERTYPE_QINQ)) {
  97                 Header8021qBuilder headerBuilder = new Header8021qBuilder();
  98                 headerBuilder.setTPID(Header8021qType.forValue(nextField));
  99
 100                 // Read 2 more bytes for priority (3bits), drop eligible (1bit),
 101                 // vlan-id (12bits)
 102                 byte[] vlanBytes = BitBufferHelper.getBits(data, 112 + extraHeaderBits, 16);
 103
 104                 // Remove the sign & right-shift to get the priority code
 105                 headerBuilder.setPriorityCode((short) ((vlanBytes[0] & 0xff) >> 5));
 106
 107                 // Remove the sign & remove priority code bits & right-shift to
 108                 // get drop-eligible bit
 109                 headerBuilder.setDropEligible(1 == (vlanBytes[0] & 0xff & 0x10) >> 4);
 110
 111                 // Remove priority code & drop-eligible bits, to get the VLAN-id
 112                 vlanBytes[0] = (byte) (vlanBytes[0] & 0x0F);
 113                 headerBuilder.setVlan(new VlanId(BitBufferHelper.getInt(vlanBytes)));
 114
 115                 // Add 802.1Q header to the growing collection
 116                 headerList.add(headerBuilder.build());
 117
 118                 // Reset value of "nextField" to correspond to following 2 bytes
 119                 // for next 802.1Q header or EtherType/Length
 120                 nextField = BitBufferHelper.getInt(BitBufferHelper.getBits(data, 128 + extraHeaderBits, 16));
 121
 122                 // 802.1Q header means payload starts at a later position
 123                 extraHeaderBits += 32;
 124             }
 125             // Set 802.1Q headers
 126             if (!headerList.isEmpty()) {
 127                 epBuilder.setHeader8021q(headerList);
 128             }
 129
 130             // Deserialize the EtherType or Length field
 131             if (nextField >= ETHERTYPE_MIN) {
 132                 epBuilder.setEthertype(KnownEtherType.forValue(nextField));
 133             } else if (nextField <= LENGTH_MAX) {
 134                 epBuilder.setEthernetLength(nextField);
 135             } else {
 136                 LOG.debug("Undefined header, value is not valid EtherType or length.  Value is {}", nextField);
 137             }
 138
 139             // Determine start & end of payload
 140             int payloadStart = (112 + extraHeaderBits) / NetUtils.NUM_BITS_IN_A_BYTE;
 141             int payloadEnd = data.length - 4;
 142             epBuilder.setPayloadOffset(payloadStart);
 143             epBuilder.setPayloadLength(payloadEnd - payloadStart);
 144
 145             // Deserialize the CRC
 146             epBuilder.setCrc(BitBufferHelper
 147                     .getLong(BitBufferHelper.getBits(data, (data.length - 4) * NetUtils.NUM_BITS_IN_A_BYTE, 32)));
 148
 149             // Set EthernetPacket field
 150             packetChain.add(new PacketChainBuilder().setPacket(epBuilder.build()).build());
 151
 152             // Set Payload field
 153             builder.setPayload(data);
 154         } catch (BufferException be) {
 155             LOG.info("Exception during decoding raw packet to ethernet.");
 156         }
 157
 158         // ToDo: Possibly log these values
 159         /*
 160          * if (_logger.isTraceEnabled()) {
 161          * _logger.trace("{}: {}: {} (offset {} bitsize {})", new Object[] {
 162          * this.getClass().getSimpleName(), hdrField,
 163          * HexEncode.bytesToHexString(hdrFieldBytes), startOffset, numBits }); }
 164          */
 165         builder.setPacketChain(packetChain);
 166         return builder.build();
 167     }
 168
 169     @Override
 170     public NotificationListener getConsumedNotificationListener() {
 171         return this;
 172     }
 173
 174     @Override
 175     public boolean canDecode(PacketReceived packetReceived) {
 176         return packetReceived != null && packetReceived.getPayload() != null;
 177     }
 178 }