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