bgp/parser-impl/src/main/java/org/opendaylight/protocol/bgp/parser/impl/BGPMessageFactory.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
  12 import org.opendaylight.protocol.bgp.parser.BGPDocumentedException;
  13 import org.opendaylight.protocol.bgp.parser.BGPError;
  14 import org.opendaylight.protocol.bgp.parser.BGPMessage;
  15 import org.opendaylight.protocol.bgp.parser.impl.message.BGPNotificationMessageParser;
  16 import org.opendaylight.protocol.bgp.parser.impl.message.BGPOpenMessageParser;
  17 import org.opendaylight.protocol.bgp.parser.impl.message.BGPUpdateMessageParser;
  18 import org.opendaylight.protocol.bgp.parser.message.BGPKeepAliveMessage;
  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.framework.ProtocolMessage;
  24 import org.opendaylight.protocol.framework.ProtocolMessageFactory;
  25 import org.opendaylight.protocol.util.ByteArray;
  26 import org.slf4j.Logger;
  27 import org.slf4j.LoggerFactory;
  28
  29 import com.google.common.primitives.UnsignedBytes;
  30
  31 /**
  32  * The byte array
  33  */
  34 public class BGPMessageFactory implements ProtocolMessageFactory {
  35
  36         private final static Logger logger = LoggerFactory.getLogger(BGPMessageFactory.class);
  37
  38         final static int LENGTH_FIELD_LENGTH = 2; // bytes
  39
  40         private final static int TYPE_FIELD_LENGTH = 1; // bytes
  41
  42         final static int MARKER_LENGTH = 16; // bytes
  43
  44         public final static int COMMON_HEADER_LENGTH = LENGTH_FIELD_LENGTH + TYPE_FIELD_LENGTH + MARKER_LENGTH;
  45
  46         public BGPMessageFactory() {
  47         }
  48
  49         /*
  50          * (non-Javadoc)
  51          * @see org.opendaylight.protocol.bgp.parser.BGPMessageParser#parse(byte[])
  52          */
  53         @Override
  54         public BGPMessage parse(final byte[] bytes) throws DeserializerException, DocumentedException {
  55                 if (bytes == null)
  56                         throw new IllegalArgumentException("Array of bytes is mandatory.");
  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                 if (msgBody.length != messageLength - COMMON_HEADER_LENGTH)
  78                         throw new DeserializerException("Size doesn't match size specified in header. Passed: " + msgBody.length + "; Expected: "
  79                                         + (messageLength - COMMON_HEADER_LENGTH) + ". ");
  80
  81                 logger.debug("Attempt to parse message from bytes: {}", ByteArray.bytesToHexString(msgBody));
  82
  83                 BGPMessage msg = null;
  84
  85                 switch (messageType) {
  86                 case 1:
  87                         msg = BGPOpenMessageParser.parse(msgBody);
  88                         logger.debug("Received and parsed Open Message: {}", msg);
  89                         break;
  90                 case 2:
  91                         msg = BGPUpdateMessageParser.parse(msgBody, messageLength);
  92                         logger.debug("Received and parsed Update Message: {}", msg);
  93                         break;
  94                 case 3:
  95                         msg = BGPNotificationMessageParser.parse(msgBody);
  96                         logger.debug("Received and parsed Notification Message: {}", msg);
  97                         break;
  98                 case 4:
  99                         msg = new BGPKeepAliveMessage();
 100                         if (messageLength != COMMON_HEADER_LENGTH)
 101                                 throw new BGPDocumentedException("Message length field not within valid range.", BGPError.BAD_MSG_LENGTH, ByteArray.subByte(
 102                                                 bs, 0, LENGTH_FIELD_LENGTH));
 103                         break;
 104                 default:
 105                         throw new BGPDocumentedException("Unhandled message type " + messageType, BGPError.BAD_MSG_TYPE, new byte[] { bs[LENGTH_FIELD_LENGTH] });
 106                 }
 107                 return msg;
 108         }
 109
 110         @Override
 111         public byte[] put(final ProtocolMessage msg) {
 112                 final BGPMessage bgpMsg = (BGPMessage) msg;
 113                 if (bgpMsg == null)
 114                         throw new IllegalArgumentException("BGPMessage is mandatory.");
 115
 116                 logger.trace("Serializing {}", bgpMsg);
 117
 118                 byte[] msgBody = null;
 119                 int msgType = 0;
 120
 121                 /*
 122                  * Update message is not supported
 123                  */
 124                 if (bgpMsg instanceof BGPOpenMessage) {
 125                         msgType = 1;
 126                         msgBody = BGPOpenMessageParser.put((BGPOpenMessage) bgpMsg);
 127                 } else if (bgpMsg instanceof BGPNotificationMessage) {
 128                         msgType = 3;
 129                         msgBody = BGPNotificationMessageParser.put((BGPNotificationMessage) bgpMsg);
 130                 } else if (bgpMsg instanceof BGPKeepAliveMessage) {
 131                         msgType = 4;
 132                         msgBody = new byte[0];
 133                 } else {
 134                         throw new IllegalArgumentException("Unknown instance of BGPMessage. Passed " + bgpMsg.getClass());
 135                 }
 136
 137                 final byte[] headerBytes = headerToBytes(msgBody.length + COMMON_HEADER_LENGTH, msgType);
 138                 final byte[] retBytes = new byte[headerBytes.length + msgBody.length];
 139
 140                 ByteArray.copyWhole(headerBytes, retBytes, 0);
 141                 ByteArray.copyWhole(msgBody, retBytes, COMMON_HEADER_LENGTH);
 142
 143                 logger.trace("Serialized BGP message {}.", Arrays.toString(retBytes));
 144                 return retBytes;
 145         }
 146
 147         /**
 148          * Serializes this BGP Message header to byte array.
 149          *
 150          * @return byte array representation of this header
 151          */
 152         public byte[] headerToBytes(final int msgLength, final int msgType) {
 153                 final byte[] retBytes = new byte[COMMON_HEADER_LENGTH];
 154
 155                 Arrays.fill(retBytes, 0, MARKER_LENGTH, (byte) 0xff);
 156
 157                 System.arraycopy(ByteArray.intToBytes(msgLength), Integer.SIZE / Byte.SIZE - LENGTH_FIELD_LENGTH, retBytes, MARKER_LENGTH,
 158                                 LENGTH_FIELD_LENGTH);
 159
 160                 retBytes[MARKER_LENGTH + LENGTH_FIELD_LENGTH] = (byte) msgType;
 161
 162                 return retBytes;
 163         }
 164 }