applications/topology-lldp-discovery/src/main/java/org/opendaylight/openflowplugin/applications/topology/lldp/utils/LLDPDiscoveryUtils.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.openflowplugin.applications.topology.lldp.utils;
   9
  10 import com.google.common.base.Preconditions;
  11 import com.google.common.hash.HashCode;
  12 import com.google.common.hash.HashFunction;
  13 import com.google.common.hash.Hasher;
  14 import com.google.common.hash.Hashing;
  15 import java.lang.management.ManagementFactory;
  16 import java.nio.ByteBuffer;
  17 import java.nio.charset.Charset;
  18 import java.nio.charset.StandardCharsets;
  19 import java.util.Arrays;
  20 import java.util.Optional;
  21 import org.apache.commons.lang3.ArrayUtils;
  22 import org.opendaylight.mdsal.eos.binding.api.Entity;
  23 import org.opendaylight.mdsal.eos.binding.api.EntityOwnershipService;
  24 import org.opendaylight.mdsal.eos.common.api.EntityOwnershipState;
  25 import org.opendaylight.openflowplugin.applications.topology.lldp.LLDPActivator;
  26 import org.opendaylight.openflowplugin.libraries.liblldp.Ethernet;
  27 import org.opendaylight.openflowplugin.libraries.liblldp.LLDP;
  28 import org.opendaylight.openflowplugin.libraries.liblldp.LLDPTLV;
  29 import org.opendaylight.openflowplugin.libraries.liblldp.NetUtils;
  30 import org.opendaylight.openflowplugin.libraries.liblldp.PacketException;
  31 import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.topology.discovery.rev130819.LinkDiscoveredBuilder;
  32 import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.NodeConnectorId;
  33 import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.NodeConnectorRef;
  34 import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.NodeId;
  35 import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.Nodes;
  36 import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.node.NodeConnector;
  37 import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.node.NodeConnectorKey;
  38 import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.nodes.Node;
  39 import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.nodes.NodeKey;
  40 import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.TpId;
  41 import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.network.topology.topology.Link;
  42 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
  43 import org.slf4j.Logger;
  44 import org.slf4j.LoggerFactory;
  45
  46 public final class LLDPDiscoveryUtils {
  47     private static final Logger LOG = LoggerFactory.getLogger(LLDPDiscoveryUtils.class);
  48
  49     private static final short MINIMUM_LLDP_SIZE = 61;
  50     public static final short ETHERNET_TYPE_VLAN = (short) 0x8100;
  51     public static final short ETHERNET_TYPE_LLDP = (short) 0x88cc;
  52     private static final short ETHERNET_TYPE_OFFSET = 12;
  53     private static final short ETHERNET_VLAN_OFFSET = ETHERNET_TYPE_OFFSET + 4;
  54     private static final String SERVICE_ENTITY_TYPE = "org.opendaylight.mdsal.ServiceEntityType";
  55
  56     private LLDPDiscoveryUtils() {
  57     }
  58
  59     public static String macToString(byte[] mac) {
  60         StringBuilder builder = new StringBuilder();
  61         for (int i = 0; i < mac.length; i++) {
  62             builder.append(String.format("%02X%s", mac[i], i < mac.length - 1 ? ":" : ""));
  63         }
  64
  65         return builder.toString();
  66     }
  67
  68     /**
  69      * Returns the encoded in custom TLV for the given lldp.
  70      *
  71      * @param payload lldp payload
  72      * @return nodeConnectorId - encoded in custom TLV of given lldp
  73      * @see LLDPDiscoveryUtils#lldpToNodeConnectorRef(byte[], boolean)
  74      */
  75     public static NodeConnectorRef lldpToNodeConnectorRef(byte[] payload)  {
  76         return lldpToNodeConnectorRef(payload, false);
  77     }
  78
  79     /**
  80      * Returns the encoded in custom TLV for the given lldp.
  81      *
  82      * @param payload lldp payload
  83      * @param useExtraAuthenticatorCheck make it more secure (CVE-2015-1611 CVE-2015-1612)
  84      * @return nodeConnectorId - encoded in custom TLV of given lldp
  85      */
  86     @SuppressWarnings("checkstyle:IllegalCatch")
  87     public static NodeConnectorRef lldpToNodeConnectorRef(byte[] payload, boolean useExtraAuthenticatorCheck)  {
  88         NodeConnectorRef nodeConnectorRef = null;
  89
  90         if (isLLDP(payload)) {
  91             Ethernet ethPkt = new Ethernet();
  92             try {
  93                 ethPkt.deserialize(payload, 0, payload.length * NetUtils.NUM_BITS_IN_A_BYTE);
  94             } catch (PacketException e) {
  95                 LOG.warn("Failed to decode LLDP packet", e);
  96                 return nodeConnectorRef;
  97             }
  98
  99             LLDP lldp = (LLDP) ethPkt.getPayload();
 100
 101             try {
 102                 NodeId srcNodeId = null;
 103                 NodeConnectorId srcNodeConnectorId = null;
 104
 105                 final LLDPTLV systemIdTLV = lldp.getSystemNameId();
 106                 if (systemIdTLV != null) {
 107                     String srcNodeIdString = new String(systemIdTLV.getValue(), Charset.defaultCharset());
 108                     srcNodeId = new NodeId(srcNodeIdString);
 109                 } else {
 110                     throw new Exception("Node id wasn't specified via systemNameId in LLDP packet.");
 111                 }
 112
 113                 final LLDPTLV nodeConnectorIdLldptlv = lldp.getCustomTLV(LLDPTLV.createPortSubTypeCustomTLVKey());
 114                 if (nodeConnectorIdLldptlv != null) {
 115                     srcNodeConnectorId = new NodeConnectorId(LLDPTLV.getCustomString(
 116                             nodeConnectorIdLldptlv.getValue(), nodeConnectorIdLldptlv.getLength()));
 117                 } else {
 118                     throw new Exception("Node connector wasn't specified via Custom TLV in LLDP packet.");
 119                 }
 120
 121                 if (useExtraAuthenticatorCheck) {
 122                     boolean secure = checkExtraAuthenticator(lldp, srcNodeConnectorId);
 123                     if (!secure) {
 124                         LOG.warn("SECURITY ALERT: there is probably a LLDP spoofing attack in progress.");
 125                         throw new Exception(
 126                                 "Attack. LLDP packet with inconsistent extra authenticator field was received.");
 127                     }
 128                 }
 129
 130                 InstanceIdentifier<NodeConnector> srcInstanceId = InstanceIdentifier.builder(Nodes.class)
 131                         .child(Node.class, new NodeKey(srcNodeId))
 132                         .child(NodeConnector.class, new NodeConnectorKey(srcNodeConnectorId))
 133                         .build();
 134                 nodeConnectorRef = new NodeConnectorRef(srcInstanceId);
 135             } catch (Exception e) {
 136                 LOG.debug("Caught exception while parsing out lldp optional and custom fields", e);
 137             }
 138         }
 139         return nodeConnectorRef;
 140     }
 141
 142     /**
 143      * Gets an extra authenticator for lldp security.
 144      *
 145      * @param nodeConnectorId the NodeConnectorId
 146      * @return extra authenticator for lldp security
 147      */
 148     public static byte[] getValueForLLDPPacketIntegrityEnsuring(final NodeConnectorId nodeConnectorId) {
 149         String finalKey;
 150         if (LLDPActivator.getLldpSecureKey() != null && !LLDPActivator.getLldpSecureKey().isEmpty()) {
 151             finalKey = LLDPActivator.getLldpSecureKey();
 152         } else {
 153             finalKey = ManagementFactory.getRuntimeMXBean().getName();
 154         }
 155         final String pureValue = nodeConnectorId + finalKey;
 156
 157         final byte[] pureBytes = pureValue.getBytes(StandardCharsets.UTF_8);
 158         HashFunction hashFunction = Hashing.md5();
 159         Hasher hasher = hashFunction.newHasher();
 160         HashCode hashedValue = hasher.putBytes(pureBytes).hash();
 161         return hashedValue.asBytes();
 162     }
 163
 164     public static boolean isEntityOwned(final EntityOwnershipService eos, final String nodeId) {
 165         Preconditions.checkNotNull(eos, "Entity ownership service must not be null");
 166
 167         EntityOwnershipState state = null;
 168         Optional<EntityOwnershipState> status = getCurrentOwnershipStatus(eos, nodeId);
 169         if (status.isPresent()) {
 170             state = status.get();
 171         } else {
 172             LOG.error("Fetching ownership status failed for node {}", nodeId);
 173         }
 174         return state != null && state.equals(EntityOwnershipState.IS_OWNER);
 175     }
 176
 177     public static org.opendaylight.yang.gen.v1.urn.opendaylight.flow.topology.discovery.rev130819
 178             .LinkDiscovered toLLDPLinkDiscovered(Link link) {
 179         return new LinkDiscoveredBuilder()
 180                 .setSource(getNodeConnectorRefFromLink(link.getSource().getSourceTp(),
 181                         link.getSource().getSourceNode()))
 182                 .setDestination(getNodeConnectorRefFromLink(link.getDestination().getDestTp(),
 183                         link.getDestination().getDestNode()))
 184                 .build();
 185     }
 186
 187     private static boolean isLLDP(final byte[] packet) {
 188         if (packet == null || packet.length < MINIMUM_LLDP_SIZE) {
 189             return false;
 190         }
 191
 192         final ByteBuffer bb = ByteBuffer.wrap(packet);
 193
 194         short ethernetType = bb.getShort(ETHERNET_TYPE_OFFSET);
 195
 196         if (ethernetType == ETHERNET_TYPE_VLAN) {
 197             ethernetType = bb.getShort(ETHERNET_VLAN_OFFSET);
 198         }
 199
 200         return ethernetType == ETHERNET_TYPE_LLDP;
 201     }
 202
 203     private static boolean checkExtraAuthenticator(LLDP lldp, NodeConnectorId srcNodeConnectorId) {
 204         final LLDPTLV hashLldptlv = lldp.getCustomTLV(LLDPTLV.createSecSubTypeCustomTLVKey());
 205         boolean secAuthenticatorOk = false;
 206         if (hashLldptlv != null) {
 207             byte[] rawTlvValue = hashLldptlv.getValue();
 208             byte[] lldpCustomSecurityHash = ArrayUtils.subarray(rawTlvValue, 4, rawTlvValue.length);
 209             byte[] calculatedHash = getValueForLLDPPacketIntegrityEnsuring(srcNodeConnectorId);
 210             secAuthenticatorOk = Arrays.equals(calculatedHash, lldpCustomSecurityHash);
 211         } else {
 212             LOG.debug("Custom security hint wasn't specified via Custom TLV in LLDP packet.");
 213         }
 214
 215         return secAuthenticatorOk;
 216     }
 217
 218     private static Optional<EntityOwnershipState> getCurrentOwnershipStatus(final EntityOwnershipService eos,
 219             final String nodeId) {
 220         Entity entity = createNodeEntity(nodeId);
 221         Optional<EntityOwnershipState> ownershipStatus = eos.getOwnershipState(entity);
 222
 223         if (ownershipStatus.isPresent()) {
 224             LOG.debug("Fetched ownership status for node {} is {}", nodeId, ownershipStatus.get());
 225         }
 226         return ownershipStatus;
 227     }
 228
 229     private static Entity createNodeEntity(final String nodeId) {
 230         return new Entity(SERVICE_ENTITY_TYPE, nodeId);
 231     }
 232
 233     private static NodeConnectorRef getNodeConnectorRefFromLink(final TpId tpId, final org.opendaylight.yang.gen.v1.urn
 234             .tbd.params.xml.ns.yang.network.topology.rev131021.NodeId nodeId) {
 235         String nodeConnectorId = tpId.getValue();
 236         InstanceIdentifier<NodeConnector> nciid
 237                 = InstanceIdentifier.builder(Nodes.class)
 238                 .child(
 239                         Node.class,
 240                         new NodeKey(new org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819
 241                                 .NodeId(nodeId)))
 242                 .child(
 243                         NodeConnector.class,
 244                         new NodeConnectorKey(new NodeConnectorId(nodeConnectorId)))
 245                 .build();
 246         return new NodeConnectorRef(nciid);
 247     }
 248 }