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.opendaylight.yangtools.yang.common.Uint16;
  35 import org.opendaylight.yangtools.yang.common.Uint8;
  36 import org.slf4j.Logger;
  37 import org.slf4j.LoggerFactory;
  38
  39 /**
  40  * Ethernet Packet Decoder.
  41  */
  42 public class EthernetDecoder extends AbstractPacketDecoder<PacketReceived, EthernetPacketReceived>
  43         implements PacketProcessingListener {
  44     private static final Logger LOG = LoggerFactory.getLogger(EthernetDecoder.class);
  45     public static final Integer LENGTH_MAX = 1500;
  46     public static final Integer ETHERTYPE_MIN = 1536;
  47     public static final Integer ETHERTYPE_8021Q = 0x8100;
  48     public static final Integer ETHERTYPE_QINQ = 0x9100;
  49
  50     public EthernetDecoder(NotificationPublishService notificationProviderService,
  51                            NotificationService notificationService) {
  52         super(EthernetPacketReceived.class, notificationProviderService, notificationService);
  53     }
  54
  55     @Override
  56     public void onPacketReceived(PacketReceived packetReceived) {
  57         decodeAndPublish(packetReceived);
  58     }
  59
  60     /**
  61      * Decode a RawPacket into an EthernetPacket.
  62      *
  63      * @param packetReceived
  64      *            -- data from wire to deserialize
  65      * @return EthernetPacketReceived
  66      */
  67     @Override
  68     public EthernetPacketReceived decode(PacketReceived packetReceived) {
  69         byte[] data = packetReceived.getPayload();
  70         EthernetPacketReceivedBuilder builder = new EthernetPacketReceivedBuilder();
  71
  72         // Save original rawPacket & set the payloadOffset/payloadLength fields
  73         RawPacketFieldsBuilder rpfb = new RawPacketFieldsBuilder().setIngress(packetReceived.getIngress())
  74                 .setConnectionCookie(packetReceived.getConnectionCookie()).setFlowCookie(packetReceived.getFlowCookie())
  75                 .setTableId(packetReceived.getTableId()).setPacketInReason(packetReceived.getPacketInReason())
  76                 .setPayloadOffset(0).setPayloadLength(data.length);
  77         if (packetReceived.getMatch() != null) {
  78             rpfb.setMatch(new MatchBuilder(packetReceived.getMatch()).build());
  79         }
  80         ArrayList<PacketChain> packetChain = new ArrayList<>();
  81         packetChain.add(new PacketChainBuilder()
  82             .setPacket(new RawPacketBuilder().setRawPacketFields(rpfb.build()).build())
  83             .build());
  84
  85         try {
  86             EthernetPacketBuilder epBuilder = new EthernetPacketBuilder();
  87
  88             // Deserialize the destination & source fields
  89             epBuilder.setDestinationMac(
  90                 new MacAddress(HexEncode.bytesToHexStringFormat(BitBufferHelper.getBits(data, 0, 48))));
  91             epBuilder.setSourceMac(
  92                 new MacAddress(HexEncode.bytesToHexStringFormat(BitBufferHelper.getBits(data, 48, 48))));
  93
  94             // Deserialize the optional field 802.1Q headers
  95             Integer nextField = BitBufferHelper.getInt(BitBufferHelper.getBits(data, 96, 16));
  96             int extraHeaderBits = 0;
  97             ArrayList<Header8021q> headerList = new ArrayList<>();
  98             while (nextField.equals(ETHERTYPE_8021Q) || nextField.equals(ETHERTYPE_QINQ)) {
  99                 Header8021qBuilder headerBuilder = new Header8021qBuilder();
 100                 headerBuilder.setTPID(Header8021qType.forValue(nextField));
 101
 102                 // Read 2 more bytes for priority (3bits), drop eligible (1bit),
 103                 // vlan-id (12bits)
 104                 byte[] vlanBytes = BitBufferHelper.getBits(data, 112 + extraHeaderBits, 16);
 105
 106                 // Remove the sign & right-shift to get the priority code
 107                 headerBuilder.setPriorityCode(Uint8.valueOf((short) ((vlanBytes[0] & 0xff) >> 5)));
 108
 109                 // Remove the sign & remove priority code bits & right-shift to
 110                 // get drop-eligible bit
 111                 headerBuilder.setDropEligible(1 == (vlanBytes[0] & 0xff & 0x10) >> 4);
 112
 113                 // Remove priority code & drop-eligible bits, to get the VLAN-id
 114                 vlanBytes[0] = (byte) (vlanBytes[0] & 0x0F);
 115                 headerBuilder.setVlan(new VlanId(BitBufferHelper.getUint16(vlanBytes)));
 116
 117                 // Add 802.1Q header to the growing collection
 118                 headerList.add(headerBuilder.build());
 119
 120                 // Reset value of "nextField" to correspond to following 2 bytes
 121                 // for next 802.1Q header or EtherType/Length
 122                 nextField = BitBufferHelper.getInt(BitBufferHelper.getBits(data, 128 + extraHeaderBits, 16));
 123
 124                 // 802.1Q header means payload starts at a later position
 125                 extraHeaderBits += 32;
 126             }
 127             // Set 802.1Q headers
 128             if (!headerList.isEmpty()) {
 129                 epBuilder.setHeader8021q(headerList);
 130             }
 131
 132             // Deserialize the EtherType or Length field
 133             if (nextField >= ETHERTYPE_MIN) {
 134                 epBuilder.setEthertype(KnownEtherType.forValue(nextField));
 135             } else if (nextField <= LENGTH_MAX) {
 136                 epBuilder.setEthernetLength(Uint16.valueOf(nextField));
 137             } else {
 138                 LOG.debug("Undefined header, value is not valid EtherType or length.  Value is {}", nextField);
 139             }
 140
 141             // Determine start & end of payload
 142             int payloadStart = (112 + extraHeaderBits) / NetUtils.NUM_BITS_IN_A_BYTE;
 143             int payloadEnd = data.length - 4;
 144             epBuilder.setPayloadOffset(payloadStart);
 145             epBuilder.setPayloadLength(payloadEnd - payloadStart);
 146
 147             // Deserialize the CRC
 148             epBuilder.setCrc(BitBufferHelper
 149                     .getUint32(BitBufferHelper.getBits(data, (data.length - 4) * NetUtils.NUM_BITS_IN_A_BYTE, 32)));
 150
 151             // Set EthernetPacket field
 152             packetChain.add(new PacketChainBuilder().setPacket(epBuilder.build()).build());
 153
 154             // Set Payload field
 155             builder.setPayload(data);
 156         } catch (BufferException be) {
 157             LOG.info("Exception during decoding raw packet to ethernet.");
 158         }
 159
 160         // ToDo: Possibly log these values
 161         /*
 162          * if (_logger.isTraceEnabled()) {
 163          * _logger.trace("{}: {}: {} (offset {} bitsize {})", new Object[] {
 164          * this.getClass().getSimpleName(), hdrField,
 165          * HexEncode.bytesToHexString(hdrFieldBytes), startOffset, numBits }); }
 166          */
 167         builder.setPacketChain(packetChain);
 168         return builder.build();
 169     }
 170
 171     @Override
 172     public NotificationListener getConsumedNotificationListener() {
 173         return this;
 174     }
 175
 176     @Override
 177     public boolean canDecode(PacketReceived packetReceived) {
 178         return packetReceived != null && packetReceived.getPayload() != null;
 179     }
 180 }