bgp/parser-impl/src/main/java/org/opendaylight/protocol/bgp/parser/impl/message/open/GracefulCapabilityHandler.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.message.open;
   9
  10 import static java.util.Objects.requireNonNull;
  11 import static org.opendaylight.protocol.util.ByteBufWriteUtil.writeUnsignedShort;
  12
  13 import com.google.common.base.Preconditions;
  14 import io.netty.buffer.ByteBuf;
  15 import io.netty.buffer.Unpooled;
  16 import java.util.ArrayList;
  17 import java.util.List;
  18 import org.opendaylight.protocol.bgp.parser.BGPDocumentedException;
  19 import org.opendaylight.protocol.bgp.parser.BGPParsingException;
  20 import org.opendaylight.protocol.bgp.parser.spi.AddressFamilyRegistry;
  21 import org.opendaylight.protocol.bgp.parser.spi.CapabilityParser;
  22 import org.opendaylight.protocol.bgp.parser.spi.CapabilitySerializer;
  23 import org.opendaylight.protocol.bgp.parser.spi.CapabilityUtil;
  24 import org.opendaylight.protocol.bgp.parser.spi.SubsequentAddressFamilyRegistry;
  25 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev180329.open.message.bgp.parameters.optional.capabilities.CParameters;
  26 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev180329.open.message.bgp.parameters.optional.capabilities.CParametersBuilder;
  27 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.CParameters1;
  28 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.CParameters1Builder;
  29 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.mp.capabilities.GracefulRestartCapability;
  30 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.mp.capabilities.GracefulRestartCapability.RestartFlags;
  31 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.mp.capabilities.GracefulRestartCapabilityBuilder;
  32 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.mp.capabilities.graceful.restart.capability.Tables;
  33 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.mp.capabilities.graceful.restart.capability.Tables.AfiFlags;
  34 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.mp.capabilities.graceful.restart.capability.TablesBuilder;
  35 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev180329.AddressFamily;
  36 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev180329.SubsequentAddressFamily;
  37 import org.slf4j.Logger;
  38 import org.slf4j.LoggerFactory;
  39
  40 public final class GracefulCapabilityHandler implements CapabilityParser, CapabilitySerializer {
  41     public static final int CODE = 64;
  42
  43     private static final Logger LOG = LoggerFactory.getLogger(GracefulCapabilityHandler.class);
  44
  45     // Restart flag size, in bits
  46     private static final int RESTART_FLAGS_SIZE = 4;
  47     private static final int RESTART_FLAG_STATE = 0x8000;
  48
  49     // Restart timer size, in bits
  50     private static final int TIMER_SIZE = 12;
  51     private static final int TIMER_TOPBITS_MASK = 0x0F;
  52
  53     // Size of the capability header
  54     private static final int HEADER_SIZE = (RESTART_FLAGS_SIZE + TIMER_SIZE) / Byte.SIZE;
  55
  56     // Length of each AFI/SAFI array member, in bytes
  57     private static final int PER_AFI_SAFI_SIZE = 4;
  58
  59     private static final short AFI_FLAG_FORWARDING_STATE = 0x80;
  60
  61     private static final int MAX_RESTART_TIME = 4095;
  62
  63     private final AddressFamilyRegistry afiReg;
  64     private final SubsequentAddressFamilyRegistry safiReg;
  65
  66     public GracefulCapabilityHandler(final AddressFamilyRegistry afiReg, final SubsequentAddressFamilyRegistry safiReg) {
  67         this.afiReg = requireNonNull(afiReg);
  68         this.safiReg = requireNonNull(safiReg);
  69     }
  70
  71     private void serializeTables(final List<Tables> tables, final ByteBuf bytes) {
  72         if (tables == null) {
  73             return;
  74         }
  75         for (final Tables t : tables) {
  76             final Class<? extends AddressFamily> afi = t.getAfi();
  77             final Integer afival = this.afiReg.numberForClass(afi);
  78             Preconditions.checkArgument(afival != null, "Unhandled address family " + afi);
  79             bytes.writeShort(afival);
  80             final Class<? extends SubsequentAddressFamily> safi = t.getSafi();
  81             final Integer safival = this.safiReg.numberForClass(safi);
  82             Preconditions.checkArgument(safival != null, "Unhandled subsequent address family " + safi);
  83             bytes.writeByte(safival);
  84             if (t.getAfiFlags() != null && t.getAfiFlags().isForwardingState()) {
  85                 bytes.writeByte(AFI_FLAG_FORWARDING_STATE);
  86             } else {
  87                 bytes.writeZero(1);
  88             }
  89         }
  90     }
  91
  92     private ByteBuf serializeCapability(final GracefulRestartCapability grace) {
  93         final List<Tables> tables = grace.getTables();
  94         final int tablesSize = (tables != null) ? tables.size() : 0;
  95         final ByteBuf bytes = Unpooled.buffer(HEADER_SIZE + (PER_AFI_SAFI_SIZE * tablesSize));
  96         int timeval = 0;
  97         Integer time = grace.getRestartTime();
  98         if (time == null) {
  99             time = 0;
 100         }
 101         Preconditions.checkArgument(time >= 0 && time <= MAX_RESTART_TIME, "Restart time is " + time);
 102         timeval = time;
 103         final GracefulRestartCapability.RestartFlags flags = grace.getRestartFlags();
 104         if (flags != null && flags.isRestartState()) {
 105             writeUnsignedShort(RESTART_FLAG_STATE | timeval, bytes);
 106         } else {
 107             writeUnsignedShort(timeval, bytes);
 108         }
 109         serializeTables(tables, bytes);
 110         return bytes;
 111     }
 112
 113     @Override
 114     public void serializeCapability(final CParameters capability, final ByteBuf byteAggregator) {
 115         if (capability.getAugmentation(CParameters1.class) == null
 116             || capability.getAugmentation(CParameters1.class).getGracefulRestartCapability() == null) {
 117             return;
 118         }
 119         final GracefulRestartCapability grace = capability.getAugmentation(CParameters1.class).getGracefulRestartCapability();
 120
 121         final ByteBuf bytes = serializeCapability(grace);
 122
 123         CapabilityUtil.formatCapability(CODE, bytes, byteAggregator);
 124     }
 125
 126     @Override
 127     public CParameters parseCapability(final ByteBuf buffer) throws BGPDocumentedException, BGPParsingException {
 128         final GracefulRestartCapabilityBuilder cb = new GracefulRestartCapabilityBuilder();
 129
 130         final int flagBits = (buffer.getByte(0) >> RESTART_FLAGS_SIZE);
 131         cb.setRestartFlags(new RestartFlags((flagBits & Byte.SIZE) != 0));
 132
 133         final int timer = ((buffer.readUnsignedByte() & TIMER_TOPBITS_MASK) << Byte.SIZE) + buffer.readUnsignedByte();
 134         cb.setRestartTime(timer);
 135
 136         final List<Tables> tables = new ArrayList<>();
 137         while (buffer.readableBytes() != 0) {
 138             final int afiVal = buffer.readShort();
 139             final Class<? extends AddressFamily> afi = this.afiReg.classForFamily(afiVal);
 140             if (afi == null) {
 141                 LOG.debug("Ignoring GR capability for unknown address family {}", afiVal);
 142                 buffer.skipBytes(PER_AFI_SAFI_SIZE - 2);
 143                 continue;
 144             }
 145             final int safiVal = buffer.readUnsignedByte();
 146             final Class<? extends SubsequentAddressFamily> safi = this.safiReg.classForFamily(safiVal);
 147             if (safi == null) {
 148                 LOG.debug("Ignoring GR capability for unknown subsequent address family {}", safiVal);
 149                 buffer.skipBytes(1);
 150                 continue;
 151             }
 152             final int flags = buffer.readUnsignedByte();
 153             tables.add(new TablesBuilder().setAfi(afi).setSafi(safi).setAfiFlags(new AfiFlags((flags & AFI_FLAG_FORWARDING_STATE) != 0)).build());
 154         }
 155         cb.setTables(tables);
 156         return new CParametersBuilder().addAugmentation(CParameters1.class, new CParameters1Builder()
 157             .setGracefulRestartCapability(cb.build()).build()).build();
 158     }
 159 }