pcep/spi/src/main/java/org/opendaylight/protocol/pcep/spi/AbstractObjectWithTlvsParser.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.pcep.spi;
   9
  10 import org.opendaylight.protocol.util.ByteArray;
  11 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.Tlv;
  12 import org.slf4j.Logger;
  13 import org.slf4j.LoggerFactory;
  14
  15 import com.google.common.base.Preconditions;
  16
  17 public abstract class AbstractObjectWithTlvsParser<T> implements ObjectParser, ObjectSerializer {
  18
  19         private static final Logger LOG = LoggerFactory.getLogger(AbstractObjectWithTlvsParser.class);
  20
  21         private static final int TLV_TYPE_F_LENGTH = 2;
  22         private static final int TLV_LENGTH_F_LENGTH = 2;
  23         private static final int TLV_HEADER_LENGTH = TLV_LENGTH_F_LENGTH + TLV_TYPE_F_LENGTH;
  24
  25         protected static final int PADDED_TO = 4;
  26
  27         private final TlvHandlerRegistry tlvReg;
  28
  29         protected AbstractObjectWithTlvsParser(final TlvHandlerRegistry tlvReg) {
  30                 this.tlvReg = Preconditions.checkNotNull(tlvReg);
  31         }
  32
  33         protected final void parseTlvs(final T builder, final byte[] bytes) throws PCEPDeserializerException {
  34                 if (bytes == null) {
  35                         throw new IllegalArgumentException("Byte array is mandatory.");
  36                 }
  37                 if (bytes.length == 0) {
  38                         return;
  39                 }
  40
  41                 int length;
  42                 int byteOffset = 0;
  43                 int type = 0;
  44
  45                 while (byteOffset < bytes.length) {
  46                         type = ByteArray.bytesToInt(ByteArray.subByte(bytes, byteOffset, TLV_TYPE_F_LENGTH));
  47                         byteOffset += TLV_TYPE_F_LENGTH;
  48                         length = ByteArray.bytesToInt(ByteArray.subByte(bytes, byteOffset, TLV_LENGTH_F_LENGTH));
  49                         byteOffset += TLV_LENGTH_F_LENGTH;
  50
  51                         if (TLV_HEADER_LENGTH + length > bytes.length) {
  52                                 throw new PCEPDeserializerException("Wrong length specified. Passed: " + (TLV_HEADER_LENGTH + length) + "; Expected: <= "
  53                                                 + (bytes.length - byteOffset) + ".");
  54                         }
  55
  56                         final byte[] tlvBytes = ByteArray.subByte(bytes, byteOffset, length);
  57
  58                         LOG.trace("Attempt to parse tlv from bytes: {}", ByteArray.bytesToHexString(tlvBytes));
  59                         final TlvParser parser = this.tlvReg.getTlvParser(type);
  60                         if (parser != null) {
  61                                 final Tlv tlv = parser.parseTlv(tlvBytes);
  62                                 LOG.trace("Tlv was parsed. {}", tlv);
  63                                 addTlv(builder, tlv);
  64                         } else {
  65                                 LOG.warn("Unknown TLV received. Type {}. Ignoring it.", type);
  66                         }
  67                         byteOffset += length + getPadding(TLV_HEADER_LENGTH + length, PADDED_TO);
  68                 }
  69         }
  70
  71         protected final byte[] serializeTlv(final Tlv tlv) {
  72
  73                 final TlvSerializer serializer = this.tlvReg.getTlvSerializer(tlv);
  74
  75                 final byte[] typeBytes = ByteArray.intToBytes(serializer.getType(), TLV_TYPE_F_LENGTH);
  76
  77                 final byte[] valueBytes = serializer.serializeTlv(tlv);
  78
  79                 final byte[] lengthBytes = ByteArray.intToBytes(valueBytes.length, TLV_LENGTH_F_LENGTH);
  80
  81                 final byte[] bytes = new byte[TLV_HEADER_LENGTH + valueBytes.length + getPadding(TLV_HEADER_LENGTH + valueBytes.length, PADDED_TO)];
  82
  83                 int byteOffset = 0;
  84                 System.arraycopy(typeBytes, 0, bytes, byteOffset, TLV_TYPE_F_LENGTH);
  85                 byteOffset += TLV_TYPE_F_LENGTH;
  86                 System.arraycopy(lengthBytes, 0, bytes, byteOffset, TLV_LENGTH_F_LENGTH);
  87                 byteOffset += TLV_LENGTH_F_LENGTH;
  88                 System.arraycopy(valueBytes, 0, bytes, byteOffset, valueBytes.length);
  89                 return bytes;
  90         }
  91
  92         public abstract void addTlv(final T builder, final Tlv tlv);
  93
  94         protected static int getPadding(final int length, final int padding) {
  95                 return (padding - (length % padding)) % padding;
  96         }
  97 }