utils/misc/src/main/java/org/onlab/packet/ONLabLddp.java - onos - Gitiles

 /*
  * Copyright 2014 Open Networking Laboratory
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 package org.onlab.packet;

 import java.nio.ByteBuffer;
 import java.util.Arrays;
 import java.util.LinkedList;
 import java.util.List;

 import org.apache.commons.lang.ArrayUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;


 /**
  * LLDP packets OpenVirteX uses for discovery of physical network topology.
  * Refer to IEEE Std 802.1ABTM-2009 for more information.
  *
  */
 @Deprecated
 public class ONLabLddp extends LLDP {

     private static final Logger LOG = LoggerFactory.getLogger(ONLabLddp.class);
     // ON.Lab OUI and OVX name for organizationally specific TLVs
     public static final byte[] ONLAB_OUI = {(byte) 0xa4, 0x23, 0x05};
     public static final String OVX_NAME = "OpenVirteX";
     public static final byte[] LLDP_NICIRA = {0x01, 0x23, 0x20, 0x00, 0x00,
         0x01};
     public static final byte[] LLDP_MULTICAST = {0x01, (byte) 0x80,
         (byte) 0xc2, 0x00, 0x00, 0x0e};
     public static final byte[] BDDP_MULTICAST = {(byte) 0xff, (byte) 0xff,
         (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff};
     public static final short ETHERTYPE_VLAN = (short) 0x8100;

     // TLV constants: type, size and subtype
     // Organizationally specific TLV also have packet offset and contents of TLV
     // header
     private static final byte CHASSIS_TLV_TYPE = 1;
     private static final byte CHASSIS_TLV_SIZE = 7;
     private static final byte CHASSIS_TLV_SUBTYPE = 4;

     private static final byte PORT_TLV_TYPE = 2;
     private static final byte PORT_TLV_SIZE = 5;
     private static final byte PORT_TLV_SUBTYPE = 2;

     private static final byte TTL_TLV_TYPE = 3;
     private static final byte TTL_TLV_SIZE = 2;

     private static final byte NAME_TLV_TYPE = 127;
     // 4 = OUI (3) + subtype (1)
     private static final byte NAME_TLV_SIZE = (byte) (4 + ONLabLddp.OVX_NAME.length());
     private static final byte NAME_TLV_SUBTYPE = 1;
     private static final short NAME_TLV_OFFSET = 34;
     private static final short NAME_TLV_HEADER = (short) ((NAME_TLV_TYPE << 9) | NAME_TLV_SIZE);
     // Contents of full name TLV
     private static final byte[] NAME_TLV = ByteBuffer.allocate(NAME_TLV_SIZE + 2)
             .putShort(NAME_TLV_HEADER).put(ONLAB_OUI).put(NAME_TLV_SUBTYPE)
             .put(OVX_NAME.getBytes()).array();

     private static final byte DPID_TLV_TYPE = 127;
     private static final byte DPID_TLV_SIZE = (byte) (12); // 12 = OUI (3) + subtype
     // (1) + dpid (8)
     private static final byte DPID_TLV_SUBTYPE = 2;
     private static final short DPID_TLV_HEADER = (short) ((DPID_TLV_TYPE << 9) | DPID_TLV_SIZE);
     // Contents of dpid TLV
     // Note that this does *not* contain the actual dpid since we cannot match
     // on it
     private static final byte[] DPID_TLV = ByteBuffer.allocate(DPID_TLV_SIZE + 2 - 8)
             .putShort(DPID_TLV_HEADER).put(ONLAB_OUI).put(DPID_TLV_SUBTYPE)
             .array();

     // Pre-built contents of both organizationally specific TLVs
     private static final byte[] OUI_TLV = ArrayUtils.addAll(NAME_TLV, DPID_TLV);

     // Default switch, port number and TTL
     private static final byte[] DEFAULT_DPID = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
         0x00, 0x00 };
     private static final int DEFAULT_PORT = 0;
     private static final short DEFAULT_TTL = 120; // in seconds

     // Minimum and OVX-generated LLDP packet sizes
     private static final short MINIMUM_LLDP_SIZE = 61;
     // Add 12 for 2-byte header of each TLV and a single EndOfLLDPTLV
     private static final short OVX_LLDP_SIZE = (short) (CHASSIS_TLV_SIZE
             + PORT_TLV_SIZE + TTL_TLV_SIZE + NAME_TLV_SIZE + DPID_TLV_SIZE + 12);

     // Field offsets in OVX-generated LLDP
     private static final short ETHERTYPE_OFFSET = 12;
     private static final short PORT_OFFSET = 26;
     private static final short DPID_OFFSET = 56;

     // Private member fields
     // Byte arrays for TLV information string
     private ByteBuffer bb;
     private final byte[] chassisId = new byte[CHASSIS_TLV_SIZE];
     private final byte[] portId = new byte[PORT_TLV_SIZE];
     private final byte[] ttl = new byte[TTL_TLV_SIZE];
     private final byte[] ouiName = new byte[NAME_TLV_SIZE];
     private final byte[] ouiDpid = new byte[DPID_TLV_SIZE];

     // TLVs
     private final LLDPTLV chassisTLV;
     private final LLDPTLV portTLV;
     private final LLDPTLV ttlTLV;
     private final LLDPTLV ouiNameTLV;
     private final LLDPTLV ouiDpidTLV;
     private final List<LLDPTLV> optionalTLVList;

     /**
      * Instantiates a new OVX LDDP message.
      */
     public ONLabLddp() {
         // Create TLVs
         this.chassisTLV = new LLDPTLV();
         this.portTLV = new LLDPTLV();
         this.ttlTLV = new LLDPTLV();
         this.ouiNameTLV = new LLDPTLV();
         this.ouiDpidTLV = new LLDPTLV();
         this.optionalTLVList = new LinkedList<LLDPTLV>();
         this.optionalTLVList.add(this.ouiNameTLV);
         this.optionalTLVList.add(this.ouiDpidTLV);

         // Add TLVs to LLDP packet
         this.setChassisId(this.chassisTLV);
         this.setPortId(this.portTLV);
         this.setTtl(this.ttlTLV);
         this.setOptionalTLVList(this.optionalTLVList);

         // Set TLVs to default values
         this.setChassisTLV(DEFAULT_DPID);
         this.setPortTLV(DEFAULT_PORT);
         this.setTTLTLV(DEFAULT_TTL);
         this.setOUIName(ONLabLddp.OVX_NAME);
         this.setOUIDpid(DEFAULT_DPID);
     }

     /**
      * Sets chassis TLV. Note that we can only put 6 bytes in the chassis ID, so
      * we use another organizationally specific TLV to put the full dpid (see
      * setOUIDpid()).
      *
      * @param dpid the switch DPID
      */
     private void setChassisTLV(final byte[] dpid) {
         this.bb = ByteBuffer.wrap(this.chassisId);
         this.bb.put(CHASSIS_TLV_SUBTYPE);
         for (int i = 2; i < 8; i++) {
             bb.put(dpid[i]);
         }
         this.chassisTLV.setLength(CHASSIS_TLV_SIZE);
         this.chassisTLV.setType(CHASSIS_TLV_TYPE);
         this.chassisTLV.setValue(this.chassisId);
     }

     /**
      * Sets port TLV.
      *
      * @param portNumber the port number
      */
     private void setPortTLV(final int portNumber) {
         this.bb = ByteBuffer.wrap(this.portId);
         this.bb.put(PORT_TLV_SUBTYPE);
         this.bb.putInt(portNumber);

         this.portTLV.setLength(PORT_TLV_SIZE);
         this.portTLV.setType(PORT_TLV_TYPE);
         this.portTLV.setValue(this.portId);
     }

     /**
      * Sets Time To Live TLV.
      *
      * @param time the time to live
      */
     private void setTTLTLV(final short time) {
         this.bb = ByteBuffer.wrap(this.ttl);
         this.bb.putShort(time);

         this.ttlTLV.setLength(TTL_TLV_SIZE);
         this.ttlTLV.setType(TTL_TLV_TYPE);
         this.ttlTLV.setValue(this.ttl);
     }

     /**
      * Set. organizationally specific TLV for OVX name (subtype 1).
      *
      * @param name the name
      */
     private void setOUIName(final String name) {
         this.bb = ByteBuffer.wrap(ouiName);
         this.bb.put(ONLabLddp.ONLAB_OUI);
         this.bb.put(NAME_TLV_SUBTYPE);
         this.bb.put(name.getBytes());

         this.ouiNameTLV.setLength(NAME_TLV_SIZE);
         this.ouiNameTLV.setType(NAME_TLV_TYPE);
         this.ouiNameTLV.setValue(ouiName);
     }

     /**
      * Sets organizationally specific TLV for OVX full dpid (subtype 2).
      *
      * @param dpid the switch DPID
      */
     private void setOUIDpid(final byte[] dpid) {
         this.bb = ByteBuffer.wrap(ouiDpid);
         this.bb.put(ONLabLddp.ONLAB_OUI);
         this.bb.put(DPID_TLV_SUBTYPE);
         this.bb.put(dpid);

         this.ouiDpidTLV.setLength(DPID_TLV_SIZE);
         this.ouiDpidTLV.setType(DPID_TLV_TYPE);
         this.ouiDpidTLV.setValue(ouiDpid);
     }

     /**
      * Sets switch DPID in LLDP packet.
      *
      * @param dp the switch instance
      */
     public void setSwitch(long dp) {
         final byte[] dpid = ByteBuffer.allocate(8).putLong(dp)
                 .array();
         this.setChassisTLV(dpid);
         this.setOUIDpid(dpid);
     }

     /**
      * Sets port in LLDP packet.
      *
      * @param port the port instance
      */
     public void setPort(int port) {
         this.setPortTLV(port);
     }

     /**
      * Serializes full LLDP packet to byte array. Need to set both switch and
      * port before you can serialize.
      */
     @Override
     public byte[] serialize() {
         return super.serialize();
     }

     /**
      * Checks if LLDP packet has correct size, LLDP multicast address, and
      * ethertype. Packet assumed to have Ethernet header.
      *
      * @param packet packet data
      * @return true if packet is LLDP, false otherwise
      */
     public static boolean isLLDP(final byte[] packet) {
         // Does packet exist and does it have the mininum size?
         if (packet == null || packet.length < MINIMUM_LLDP_SIZE) {
             return false;
         }

         // Packet has LLDP multicast destination address?
         final ByteBuffer bb = ByteBuffer.wrap(packet);
         final byte[] dst = new byte[6];
         bb.get(dst);

         if (!(Arrays.equals(dst, ONLabLddp.LLDP_NICIRA)
                 || Arrays.equals(dst, ONLabLddp.LLDP_MULTICAST) || Arrays.equals(
                         dst, ONLabLddp.BDDP_MULTICAST))) {

             return false;
         }

         // Fetch ethertype, skip VLAN tag if it's there
         short etherType = bb.getShort(ETHERTYPE_OFFSET);
         if (etherType == ETHERTYPE_VLAN) {
             etherType = bb.getShort(ETHERTYPE_OFFSET + 4);
         }

         // Check ethertype
         if (etherType == Ethernet.TYPE_LLDP) {
             return true;
         }
         if (etherType == Ethernet.TYPE_BSN) {
             return true;
         }

         return false;

     }

     /**
      * Checks if packet has size of OVX-generated LLDP, and correctness of two
      * organizationally specific TLVs that use ON.Lab's OUI. Assumes packet is
      * valid LLDP packet
      *
      * @param packet packet data
      * @return eth type or -1
      */
     public static short isOVXLLDP(byte[] packet) {
         if (packet.length < OVX_LLDP_SIZE) {
             return -1;
         }

         // Extra offset due to VLAN tag
         final ByteBuffer bb = ByteBuffer.wrap(packet);
         int offset = 0;
         short ethType = bb.getShort(ETHERTYPE_OFFSET);
         if (ethType != Ethernet.TYPE_LLDP
                 && ethType != Ethernet.TYPE_BSN) {
             offset = 4;
             ethType = bb.getShort(ETHERTYPE_OFFSET + offset);
             if (ethType != Ethernet.TYPE_LLDP
                     && ethType != Ethernet.TYPE_BSN) {
                 return -1;
             }
         }

         // Compare packet's organizationally specific TLVs to the expected
         // values
         for (int i = 0; i < OUI_TLV.length; i++) {
             if (packet[NAME_TLV_OFFSET + offset + i] != OUI_TLV[i]) {
                 return -1;
             }
         }

         return ethType;
     }

     /**
      * Extracts dpid and port from OVX-generated LLDP packet.
      *
      * @param packet packet data
      * @return Dpid and port
      */
     public static DPIDandPort parseLLDP(final byte[] packet) {
         final ByteBuffer bb = ByteBuffer.wrap(packet);

         // Extra offset due to VLAN tag
         int offset = 0;
         if (bb.getShort(ETHERTYPE_OFFSET) != Ethernet.TYPE_LLDP
                 && bb.getShort(ETHERTYPE_OFFSET) != Ethernet.TYPE_BSN) {
             offset = 4;
         }

         final int port = bb.getInt(PORT_OFFSET + offset);
         final long dpid = bb.getLong(DPID_OFFSET + offset);

         return new DPIDandPort(dpid, port);
     }

     public static class DPIDandPort {

         private final long dpid;
         private final int port;

         public DPIDandPort(long dpid, int port) {
             this.dpid = dpid;
             this.port = port;
         }

         public long getDpid() {
             return this.dpid;
         }

         public int getPort() {
             return this.port;
         }

     }

 }
	/*
	* Copyright 2014 Open Networking Laboratory
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/
	package org.onlab.packet;

	import java.nio.ByteBuffer;
	import java.util.Arrays;
	import java.util.LinkedList;
	import java.util.List;

	import org.apache.commons.lang.ArrayUtils;
	import org.slf4j.Logger;
	import org.slf4j.LoggerFactory;


	/**
	* LLDP packets OpenVirteX uses for discovery of physical network topology.
	* Refer to IEEE Std 802.1ABTM-2009 for more information.
	*
	*/
	@Deprecated
	public class ONLabLddp extends LLDP {

	private static final Logger LOG = LoggerFactory.getLogger(ONLabLddp.class);
	// ON.Lab OUI and OVX name for organizationally specific TLVs
	public static final byte[] ONLAB_OUI = {(byte) 0xa4, 0x23, 0x05};
	public static final String OVX_NAME = "OpenVirteX";
	public static final byte[] LLDP_NICIRA = {0x01, 0x23, 0x20, 0x00, 0x00,
	0x01};
	public static final byte[] LLDP_MULTICAST = {0x01, (byte) 0x80,
	(byte) 0xc2, 0x00, 0x00, 0x0e};
	public static final byte[] BDDP_MULTICAST = {(byte) 0xff, (byte) 0xff,
	(byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff};
	public static final short ETHERTYPE_VLAN = (short) 0x8100;

	// TLV constants: type, size and subtype
	// Organizationally specific TLV also have packet offset and contents of TLV
	// header
	private static final byte CHASSIS_TLV_TYPE = 1;
	private static final byte CHASSIS_TLV_SIZE = 7;
	private static final byte CHASSIS_TLV_SUBTYPE = 4;

	private static final byte PORT_TLV_TYPE = 2;
	private static final byte PORT_TLV_SIZE = 5;
	private static final byte PORT_TLV_SUBTYPE = 2;

	private static final byte TTL_TLV_TYPE = 3;
	private static final byte TTL_TLV_SIZE = 2;

	private static final byte NAME_TLV_TYPE = 127;
	// 4 = OUI (3) + subtype (1)
	private static final byte NAME_TLV_SIZE = (byte) (4 + ONLabLddp.OVX_NAME.length());
	private static final byte NAME_TLV_SUBTYPE = 1;
	private static final short NAME_TLV_OFFSET = 34;
	private static final short NAME_TLV_HEADER = (short) ((NAME_TLV_TYPE << 9) \| NAME_TLV_SIZE);
	// Contents of full name TLV
	private static final byte[] NAME_TLV = ByteBuffer.allocate(NAME_TLV_SIZE + 2)
	.putShort(NAME_TLV_HEADER).put(ONLAB_OUI).put(NAME_TLV_SUBTYPE)
	.put(OVX_NAME.getBytes()).array();

	private static final byte DPID_TLV_TYPE = 127;
	private static final byte DPID_TLV_SIZE = (byte) (12); // 12 = OUI (3) + subtype
	// (1) + dpid (8)
	private static final byte DPID_TLV_SUBTYPE = 2;
	private static final short DPID_TLV_HEADER = (short) ((DPID_TLV_TYPE << 9) \| DPID_TLV_SIZE);
	// Contents of dpid TLV
	// Note that this does not contain the actual dpid since we cannot match
	// on it
	private static final byte[] DPID_TLV = ByteBuffer.allocate(DPID_TLV_SIZE + 2 - 8)
	.putShort(DPID_TLV_HEADER).put(ONLAB_OUI).put(DPID_TLV_SUBTYPE)
	.array();

	// Pre-built contents of both organizationally specific TLVs
	private static final byte[] OUI_TLV = ArrayUtils.addAll(NAME_TLV, DPID_TLV);

	// Default switch, port number and TTL
	private static final byte[] DEFAULT_DPID = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00 };
	private static final int DEFAULT_PORT = 0;
	private static final short DEFAULT_TTL = 120; // in seconds

	// Minimum and OVX-generated LLDP packet sizes
	private static final short MINIMUM_LLDP_SIZE = 61;
	// Add 12 for 2-byte header of each TLV and a single EndOfLLDPTLV
	private static final short OVX_LLDP_SIZE = (short) (CHASSIS_TLV_SIZE
	+ PORT_TLV_SIZE + TTL_TLV_SIZE + NAME_TLV_SIZE + DPID_TLV_SIZE + 12);

	// Field offsets in OVX-generated LLDP
	private static final short ETHERTYPE_OFFSET = 12;
	private static final short PORT_OFFSET = 26;
	private static final short DPID_OFFSET = 56;

	// Private member fields
	// Byte arrays for TLV information string
	private ByteBuffer bb;
	private final byte[] chassisId = new byte[CHASSIS_TLV_SIZE];
	private final byte[] portId = new byte[PORT_TLV_SIZE];
	private final byte[] ttl = new byte[TTL_TLV_SIZE];
	private final byte[] ouiName = new byte[NAME_TLV_SIZE];
	private final byte[] ouiDpid = new byte[DPID_TLV_SIZE];

	// TLVs
	private final LLDPTLV chassisTLV;
	private final LLDPTLV portTLV;
	private final LLDPTLV ttlTLV;
	private final LLDPTLV ouiNameTLV;
	private final LLDPTLV ouiDpidTLV;
	private final List<LLDPTLV> optionalTLVList;

	/**
	* Instantiates a new OVX LDDP message.
	*/
	public ONLabLddp() {
	// Create TLVs
	this.chassisTLV = new LLDPTLV();
	this.portTLV = new LLDPTLV();
	this.ttlTLV = new LLDPTLV();
	this.ouiNameTLV = new LLDPTLV();
	this.ouiDpidTLV = new LLDPTLV();
	this.optionalTLVList = new LinkedList<LLDPTLV>();
	this.optionalTLVList.add(this.ouiNameTLV);
	this.optionalTLVList.add(this.ouiDpidTLV);

	// Add TLVs to LLDP packet
	this.setChassisId(this.chassisTLV);
	this.setPortId(this.portTLV);
	this.setTtl(this.ttlTLV);
	this.setOptionalTLVList(this.optionalTLVList);

	// Set TLVs to default values
	this.setChassisTLV(DEFAULT_DPID);
	this.setPortTLV(DEFAULT_PORT);
	this.setTTLTLV(DEFAULT_TTL);
	this.setOUIName(ONLabLddp.OVX_NAME);
	this.setOUIDpid(DEFAULT_DPID);
	}

	/**
	* Sets chassis TLV. Note that we can only put 6 bytes in the chassis ID, so
	* we use another organizationally specific TLV to put the full dpid (see
	* setOUIDpid()).
	*
	* @param dpid the switch DPID
	*/
	private void setChassisTLV(final byte[] dpid) {
	this.bb = ByteBuffer.wrap(this.chassisId);
	this.bb.put(CHASSIS_TLV_SUBTYPE);
	for (int i = 2; i < 8; i++) {
	bb.put(dpid[i]);
	}
	this.chassisTLV.setLength(CHASSIS_TLV_SIZE);
	this.chassisTLV.setType(CHASSIS_TLV_TYPE);
	this.chassisTLV.setValue(this.chassisId);
	}

	/**
	* Sets port TLV.
	*
	* @param portNumber the port number
	*/
	private void setPortTLV(final int portNumber) {
	this.bb = ByteBuffer.wrap(this.portId);
	this.bb.put(PORT_TLV_SUBTYPE);
	this.bb.putInt(portNumber);

	this.portTLV.setLength(PORT_TLV_SIZE);
	this.portTLV.setType(PORT_TLV_TYPE);
	this.portTLV.setValue(this.portId);
	}

	/**
	* Sets Time To Live TLV.
	*
	* @param time the time to live
	*/
	private void setTTLTLV(final short time) {
	this.bb = ByteBuffer.wrap(this.ttl);
	this.bb.putShort(time);

	this.ttlTLV.setLength(TTL_TLV_SIZE);
	this.ttlTLV.setType(TTL_TLV_TYPE);
	this.ttlTLV.setValue(this.ttl);
	}

	/**
	* Set. organizationally specific TLV for OVX name (subtype 1).
	*
	* @param name the name
	*/
	private void setOUIName(final String name) {
	this.bb = ByteBuffer.wrap(ouiName);
	this.bb.put(ONLabLddp.ONLAB_OUI);
	this.bb.put(NAME_TLV_SUBTYPE);
	this.bb.put(name.getBytes());

	this.ouiNameTLV.setLength(NAME_TLV_SIZE);
	this.ouiNameTLV.setType(NAME_TLV_TYPE);
	this.ouiNameTLV.setValue(ouiName);
	}

	/**
	* Sets organizationally specific TLV for OVX full dpid (subtype 2).
	*
	* @param dpid the switch DPID
	*/
	private void setOUIDpid(final byte[] dpid) {
	this.bb = ByteBuffer.wrap(ouiDpid);
	this.bb.put(ONLabLddp.ONLAB_OUI);
	this.bb.put(DPID_TLV_SUBTYPE);
	this.bb.put(dpid);

	this.ouiDpidTLV.setLength(DPID_TLV_SIZE);
	this.ouiDpidTLV.setType(DPID_TLV_TYPE);
	this.ouiDpidTLV.setValue(ouiDpid);
	}

	/**
	* Sets switch DPID in LLDP packet.
	*
	* @param dp the switch instance
	*/
	public void setSwitch(long dp) {
	final byte[] dpid = ByteBuffer.allocate(8).putLong(dp)
	.array();
	this.setChassisTLV(dpid);
	this.setOUIDpid(dpid);
	}

	/**
	* Sets port in LLDP packet.
	*
	* @param port the port instance
	*/
	public void setPort(int port) {
	this.setPortTLV(port);
	}

	/**
	* Serializes full LLDP packet to byte array. Need to set both switch and
	* port before you can serialize.
	*/
	@Override
	public byte[] serialize() {
	return super.serialize();
	}

	/**
	* Checks if LLDP packet has correct size, LLDP multicast address, and
	* ethertype. Packet assumed to have Ethernet header.
	*
	* @param packet packet data
	* @return true if packet is LLDP, false otherwise
	*/
	public static boolean isLLDP(final byte[] packet) {
	// Does packet exist and does it have the mininum size?
	if (packet == null \|\| packet.length < MINIMUM_LLDP_SIZE) {
	return false;
	}

	// Packet has LLDP multicast destination address?
	final ByteBuffer bb = ByteBuffer.wrap(packet);
	final byte[] dst = new byte[6];
	bb.get(dst);

	if (!(Arrays.equals(dst, ONLabLddp.LLDP_NICIRA)
	\|\| Arrays.equals(dst, ONLabLddp.LLDP_MULTICAST) \|\| Arrays.equals(
	dst, ONLabLddp.BDDP_MULTICAST))) {

	return false;
	}

	// Fetch ethertype, skip VLAN tag if it's there
	short etherType = bb.getShort(ETHERTYPE_OFFSET);
	if (etherType == ETHERTYPE_VLAN) {
	etherType = bb.getShort(ETHERTYPE_OFFSET + 4);
	}

	// Check ethertype
	if (etherType == Ethernet.TYPE_LLDP) {
	return true;
	}
	if (etherType == Ethernet.TYPE_BSN) {
	return true;
	}

	return false;

	}

	/**
	* Checks if packet has size of OVX-generated LLDP, and correctness of two
	* organizationally specific TLVs that use ON.Lab's OUI. Assumes packet is
	* valid LLDP packet
	*
	* @param packet packet data
	* @return eth type or -1
	*/
	public static short isOVXLLDP(byte[] packet) {
	if (packet.length < OVX_LLDP_SIZE) {
	return -1;
	}

	// Extra offset due to VLAN tag
	final ByteBuffer bb = ByteBuffer.wrap(packet);
	int offset = 0;
	short ethType = bb.getShort(ETHERTYPE_OFFSET);
	if (ethType != Ethernet.TYPE_LLDP
	&& ethType != Ethernet.TYPE_BSN) {
	offset = 4;
	ethType = bb.getShort(ETHERTYPE_OFFSET + offset);
	if (ethType != Ethernet.TYPE_LLDP
	&& ethType != Ethernet.TYPE_BSN) {
	return -1;
	}
	}

	// Compare packet's organizationally specific TLVs to the expected
	// values
	for (int i = 0; i < OUI_TLV.length; i++) {
	if (packet[NAME_TLV_OFFSET + offset + i] != OUI_TLV[i]) {
	return -1;
	}
	}

	return ethType;
	}

	/**
	* Extracts dpid and port from OVX-generated LLDP packet.
	*
	* @param packet packet data
	* @return Dpid and port
	*/
	public static DPIDandPort parseLLDP(final byte[] packet) {
	final ByteBuffer bb = ByteBuffer.wrap(packet);

	// Extra offset due to VLAN tag
	int offset = 0;
	if (bb.getShort(ETHERTYPE_OFFSET) != Ethernet.TYPE_LLDP
	&& bb.getShort(ETHERTYPE_OFFSET) != Ethernet.TYPE_BSN) {
	offset = 4;
	}

	final int port = bb.getInt(PORT_OFFSET + offset);
	final long dpid = bb.getLong(DPID_OFFSET + offset);

	return new DPIDandPort(dpid, port);
	}

	public static class DPIDandPort {

	private final long dpid;
	private final int port;

	public DPIDandPort(long dpid, int port) {
	this.dpid = dpid;
	this.port = port;
	}

	public long getDpid() {
	return this.dpid;
	}

	public int getPort() {
	return this.port;
	}

	}

	}