bgp/parser-impl/src/main/java/org/opendaylight/protocol/bgp/parser/impl/BGPMessageFactoryImpl.java

   1 /*
   2  * Copyright (c) 2013 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.protocol.bgp.parser.impl;
   9
  10 import java.util.Arrays;
  11 import java.util.List;
  12
  13 import org.opendaylight.protocol.bgp.parser.BGPDocumentedException;
  14 import org.opendaylight.protocol.bgp.parser.BGPError;
  15 import org.opendaylight.protocol.bgp.parser.BGPMessageFactory;
  16 import org.opendaylight.protocol.bgp.parser.impl.message.BGPNotificationMessageParser;
  17 import org.opendaylight.protocol.bgp.parser.impl.message.BGPOpenMessageParser;
  18 import org.opendaylight.protocol.bgp.parser.impl.message.BGPUpdateMessageParser;
  19 import org.opendaylight.protocol.bgp.parser.message.BGPNotificationMessage;
  20 import org.opendaylight.protocol.bgp.parser.message.BGPOpenMessage;
  21 import org.opendaylight.protocol.framework.DeserializerException;
  22 import org.opendaylight.protocol.framework.DocumentedException;
  23 import org.opendaylight.protocol.util.ByteArray;
  24 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130918.Keepalive;
  25 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130918.KeepaliveBuilder;
  26 import org.opendaylight.yangtools.yang.binding.Notification;
  27 import org.slf4j.Logger;
  28 import org.slf4j.LoggerFactory;
  29
  30 import com.google.common.collect.Lists;
  31 import com.google.common.primitives.UnsignedBytes;
  32
  33 /**
  34  * The byte array
  35  */
  36 public final class BGPMessageFactoryImpl implements BGPMessageFactory {
  37
  38         private final static Logger logger = LoggerFactory.getLogger(BGPMessageFactoryImpl.class);
  39
  40         final static int LENGTH_FIELD_LENGTH = 2; // bytes
  41
  42         private final static int TYPE_FIELD_LENGTH = 1; // bytes
  43
  44         final static int MARKER_LENGTH = 16; // bytes
  45
  46         public final static int COMMON_HEADER_LENGTH = LENGTH_FIELD_LENGTH + TYPE_FIELD_LENGTH + MARKER_LENGTH;
  47
  48         /*
  49          * (non-Javadoc)
  50          * @see org.opendaylight.protocol.bgp.parser.BGPMessageParser#parse(byte[])
  51          */
  52         @Override
  53         public List<Notification> parse(final byte[] bytes) throws DeserializerException, DocumentedException {
  54                 if (bytes == null) {
  55                         throw new IllegalArgumentException("Array of bytes is mandatory.");
  56                 }
  57                 if (bytes.length < COMMON_HEADER_LENGTH) {
  58                         throw new IllegalArgumentException("Too few bytes in passed array. Passed: " + bytes.length + ". Expected: >= "
  59                                         + COMMON_HEADER_LENGTH + ".");
  60                 }
  61                 /*
  62                  * byte array starts with message length
  63                  */
  64                 // final byte[] ones = new byte[MARKER_LENGTH];
  65                 // Arrays.fill(ones, (byte)0xff);
  66                 // if (Arrays.equals(bytes, ones))
  67                 // throw new BGPDocumentedException("Marker not set to ones.", BGPError.CONNECTION_NOT_SYNC);
  68                 final byte[] bs = ByteArray.cutBytes(bytes, MARKER_LENGTH);
  69                 final int messageLength = ByteArray.bytesToInt(ByteArray.subByte(bs, 0, LENGTH_FIELD_LENGTH));
  70                 final int messageType = UnsignedBytes.toInt(bs[LENGTH_FIELD_LENGTH]);
  71
  72                 final byte[] msgBody = ByteArray.cutBytes(bs, LENGTH_FIELD_LENGTH + TYPE_FIELD_LENGTH);
  73
  74                 if (messageLength < COMMON_HEADER_LENGTH) {
  75                         throw new BGPDocumentedException("Message length field not within valid range.", BGPError.BAD_MSG_LENGTH, ByteArray.subByte(bs,
  76                                         0, LENGTH_FIELD_LENGTH));
  77                 }
  78                 if (msgBody.length != messageLength - COMMON_HEADER_LENGTH) {
  79                         throw new DeserializerException("Size doesn't match size specified in header. Passed: " + msgBody.length + "; Expected: "
  80                                         + (messageLength - COMMON_HEADER_LENGTH) + ". ");
  81                 }
  82
  83                 logger.debug("Attempt to parse message from bytes: {}", ByteArray.bytesToHexString(msgBody));
  84
  85                 final Notification msg;
  86
  87                 switch (messageType) {
  88                 case 1:
  89                         msg = BGPOpenMessageParser.parse(msgBody);
  90                         logger.debug("Received and parsed Open Message: {}", msg);
  91                         break;
  92                 case 2:
  93                         msg = BGPUpdateMessageParser.parse(msgBody, messageLength);
  94                         logger.debug("Received and parsed Update Message: {}", msg);
  95                         break;
  96                 case 3:
  97                         msg = BGPNotificationMessageParser.parse(msgBody);
  98                         logger.debug("Received and parsed Notification Message: {}", msg);
  99                         break;
 100                 case 4:
 101                         msg = new KeepaliveBuilder().build();
 102                         if (messageLength != COMMON_HEADER_LENGTH) {
 103                                 throw new BGPDocumentedException("Message length field not within valid range.", BGPError.BAD_MSG_LENGTH, ByteArray.subByte(
 104                                                 bs, 0, LENGTH_FIELD_LENGTH));
 105                         }
 106                         break;
 107                 default:
 108                         throw new BGPDocumentedException("Unhandled message type " + messageType, BGPError.BAD_MSG_TYPE, new byte[] { bs[LENGTH_FIELD_LENGTH] });
 109                 }
 110
 111                 return Lists.newArrayList(msg);
 112         }
 113
 114         @Override
 115         public byte[] put(final Notification msg) {
 116                 if (msg == null) {
 117                         throw new IllegalArgumentException("BGPMessage is mandatory.");
 118                 }
 119
 120                 logger.trace("Serializing {}", msg);
 121
 122                 byte[] msgBody = null;
 123                 int msgType = 0;
 124
 125                 /*
 126                  * Update message is not supported
 127                  */
 128                 if (msg instanceof BGPOpenMessage) {
 129                         msgType = 1;
 130                         msgBody = BGPOpenMessageParser.put((BGPOpenMessage) msg);
 131                 } else if (msg instanceof BGPNotificationMessage) {
 132                         msgType = 3;
 133                         msgBody = BGPNotificationMessageParser.put((BGPNotificationMessage) msg);
 134                 } else if (msg instanceof Keepalive) {
 135                         msgType = 4;
 136                         msgBody = new byte[0];
 137                 } else {
 138                         throw new IllegalArgumentException("Unknown instance of BGPMessage. Passed " + msg.getClass());
 139                 }
 140
 141                 final byte[] headerBytes = headerToBytes(msgBody.length + COMMON_HEADER_LENGTH, msgType);
 142                 final byte[] retBytes = new byte[headerBytes.length + msgBody.length];
 143
 144                 ByteArray.copyWhole(headerBytes, retBytes, 0);
 145                 ByteArray.copyWhole(msgBody, retBytes, COMMON_HEADER_LENGTH);
 146
 147                 logger.trace("Serialized BGP message {}.", Arrays.toString(retBytes));
 148                 return retBytes;
 149         }
 150
 151         /**
 152          * Serializes this BGP Message header to byte array.
 153          *
 154          * @return byte array representation of this header
 155          */
 156         public byte[] headerToBytes(final int msgLength, final int msgType) {
 157                 final byte[] retBytes = new byte[COMMON_HEADER_LENGTH];
 158
 159                 Arrays.fill(retBytes, 0, MARKER_LENGTH, (byte) 0xff);
 160
 161                 System.arraycopy(ByteArray.intToBytes(msgLength), Integer.SIZE / Byte.SIZE - LENGTH_FIELD_LENGTH, retBytes, MARKER_LENGTH,
 162                                 LENGTH_FIELD_LENGTH);
 163
 164                 retBytes[MARKER_LENGTH + LENGTH_FIELD_LENGTH] = (byte) msgType;
 165
 166                 return retBytes;
 167         }
 168 }