bgp/parser-impl/src/main/java/org/opendaylight/protocol/bgp/parser/impl/SimpleNlriRegistry.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.concurrent.ConcurrentHashMap;
  11 import java.util.concurrent.ConcurrentMap;
  12
  13 import org.opendaylight.protocol.bgp.parser.BGPParsingException;
  14 import org.opendaylight.protocol.bgp.parser.BgpTableTypeImpl;
  15 import org.opendaylight.protocol.bgp.parser.spi.AddressFamilyRegistry;
  16 import org.opendaylight.protocol.bgp.parser.spi.NlriParser;
  17 import org.opendaylight.protocol.bgp.parser.spi.NlriRegistry;
  18 import org.opendaylight.protocol.bgp.parser.spi.SubsequentAddressFamilyRegistry;
  19 import org.opendaylight.protocol.concepts.AbstractRegistration;
  20 import org.opendaylight.protocol.util.ByteArray;
  21 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130918.BgpTableType;
  22 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130918.update.path.attributes.MpReachNlri;
  23 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130918.update.path.attributes.MpReachNlriBuilder;
  24 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130918.update.path.attributes.MpUnreachNlri;
  25 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130918.update.path.attributes.MpUnreachNlriBuilder;
  26 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.AddressFamily;
  27 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.SubsequentAddressFamily;
  28
  29 import com.google.common.base.Preconditions;
  30 import com.google.common.primitives.UnsignedBytes;
  31
  32 public final class SimpleNlriRegistry implements NlriRegistry {
  33         private final ConcurrentMap<BgpTableType, NlriParser> handlers = new ConcurrentHashMap<>();
  34         private final SubsequentAddressFamilyRegistry safiReg;
  35         private final AddressFamilyRegistry afiReg;
  36
  37         public SimpleNlriRegistry(final AddressFamilyRegistry afiReg, final SubsequentAddressFamilyRegistry safiReg) {
  38                 this.afiReg = Preconditions.checkNotNull(afiReg);
  39                 this.safiReg = Preconditions.checkNotNull(safiReg);
  40         }
  41
  42         private static BgpTableType createKey(final Class<? extends AddressFamily> afi,
  43                         final Class<? extends SubsequentAddressFamily> safi) {
  44                 Preconditions.checkNotNull(afi);
  45                 Preconditions.checkNotNull(safi);
  46                 return new BgpTableTypeImpl(afi, safi);
  47         }
  48
  49         @Override
  50         public synchronized AutoCloseable registerNlriParser(final Class<? extends AddressFamily> afi,
  51                         final Class<? extends SubsequentAddressFamily> safi, final NlriParser parser) {
  52                 final BgpTableType key = createKey(afi, safi);
  53                 final NlriParser prev = handlers.get(key);
  54                 Preconditions.checkState(prev == null, "AFI/SAFI is already bound to parser " + prev);
  55
  56                 handlers.put(key, parser);
  57                 final Object lock = this;
  58                 return new AbstractRegistration() {
  59                         @Override
  60                         protected void removeRegistration() {
  61                                 synchronized (lock) {
  62                                         handlers.remove(key);
  63                                 }
  64                         }
  65                 };
  66         }
  67
  68         private Class<? extends AddressFamily> getAfi(final byte[] header) throws BGPParsingException {
  69                 final int afiVal = UnsignedBytes.toInt(header[0]) * 256 + UnsignedBytes.toInt(header[1]);
  70                 final Class<? extends AddressFamily> afi = afiReg.classForFamily(afiVal);
  71                 if (afi == null) {
  72                         throw new BGPParsingException("Address Family Identifier: '" + afiVal + "' not supported.");
  73                 }
  74
  75                 return afi;
  76         }
  77
  78         private Class<? extends SubsequentAddressFamily> getSafi(final byte[] header) throws BGPParsingException {
  79                 final int safiVal = UnsignedBytes.toInt(header[2]);
  80                 final Class<? extends SubsequentAddressFamily> safi = safiReg.classForFamily(safiVal);
  81                 if (safi == null) {
  82                         throw new BGPParsingException("Subsequent Address Family Identifier: '" + safiVal + "' not supported.");
  83                 }
  84
  85                 return safi;
  86         }
  87
  88         @Override
  89         public MpUnreachNlri parseMpUnreach(final byte[] bytes) throws BGPParsingException {
  90                 final MpUnreachNlriBuilder builder = new MpUnreachNlriBuilder();
  91                 builder.setAfi(getAfi(bytes));
  92                 builder.setSafi(getSafi(bytes));
  93
  94                 final NlriParser parser = handlers.get(createKey(builder.getAfi(), builder.getSafi()));
  95                 parser.parseNlri(ByteArray.subByte(bytes, 3, bytes.length - 3), builder);
  96
  97                 return builder.build();
  98         }
  99
 100         @Override
 101         public MpReachNlri parseMpReach(final byte[] bytes) throws BGPParsingException {
 102                 final MpReachNlriBuilder builder = new MpReachNlriBuilder();
 103                 builder.setAfi(getAfi(bytes));
 104                 builder.setSafi(getSafi(bytes));
 105
 106                 final NlriParser parser = handlers.get(createKey(builder.getAfi(), builder.getSafi()));
 107
 108                 final int nextHopLength = UnsignedBytes.toInt(bytes[3]);
 109                 int byteOffset = 4;
 110
 111                 final byte[] nextHop = ByteArray.subByte(bytes, byteOffset, nextHopLength);
 112                 byteOffset += nextHopLength + 1;
 113
 114                 final byte[] nlri = ByteArray.subByte(bytes, byteOffset, bytes.length - byteOffset);
 115                 parser.parseNlri(nlri, nextHop, builder);
 116
 117                 return builder.build();
 118         }
 119 }