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 org.opendaylight.protocol.util.ByteBufWriteUtil.writeUnsignedShort;
  11
  12 import com.google.common.base.Preconditions;
  13 import io.netty.buffer.ByteBuf;
  14 import io.netty.buffer.Unpooled;
  15 import java.util.ArrayList;
  16 import java.util.List;
  17 import org.opendaylight.protocol.bgp.parser.BGPDocumentedException;
  18 import org.opendaylight.protocol.bgp.parser.BGPParsingException;
  19 import org.opendaylight.protocol.bgp.parser.spi.AddressFamilyRegistry;
  20 import org.opendaylight.protocol.bgp.parser.spi.CapabilityParser;
  21 import org.opendaylight.protocol.bgp.parser.spi.CapabilitySerializer;
  22 import org.opendaylight.protocol.bgp.parser.spi.CapabilityUtil;
  23 import org.opendaylight.protocol.bgp.parser.spi.SubsequentAddressFamilyRegistry;
  24 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.bgp.parameters.optional.capabilities.CParameters;
  25 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.open.bgp.parameters.optional.capabilities.c.parameters.GracefulRestartCase;
  26 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.open.bgp.parameters.optional.capabilities.c.parameters.GracefulRestartCaseBuilder;
  27 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.open.bgp.parameters.optional.capabilities.c.parameters.graceful.restart._case.GracefulRestartCapability;
  28 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.open.bgp.parameters.optional.capabilities.c.parameters.graceful.restart._case.GracefulRestartCapability.RestartFlags;
  29 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.open.bgp.parameters.optional.capabilities.c.parameters.graceful.restart._case.GracefulRestartCapabilityBuilder;
  30 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.open.bgp.parameters.optional.capabilities.c.parameters.graceful.restart._case.graceful.restart.capability.Tables;
  31 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.open.bgp.parameters.optional.capabilities.c.parameters.graceful.restart._case.graceful.restart.capability.Tables.AfiFlags;
  32 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.open.bgp.parameters.optional.capabilities.c.parameters.graceful.restart._case.graceful.restart.capability.TablesBuilder;
  33 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.AddressFamily;
  34 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.SubsequentAddressFamily;
  35 import org.slf4j.Logger;
  36 import org.slf4j.LoggerFactory;
  37
  38 public final class GracefulCapabilityHandler implements CapabilityParser, CapabilitySerializer {
  39     public static final int CODE = 64;
  40
  41     private static final Logger LOG = LoggerFactory.getLogger(GracefulCapabilityHandler.class);
  42
  43     // Restart flag size, in bits
  44     private static final int RESTART_FLAGS_SIZE = 4;
  45     private static final int RESTART_FLAG_STATE = 0x8000;
  46
  47     // Restart timer size, in bits
  48     private static final int TIMER_SIZE = 12;
  49     private static final int TIMER_TOPBITS_MASK = 0x0F;
  50
  51     // Size of the capability header
  52     private static final int HEADER_SIZE = (RESTART_FLAGS_SIZE + TIMER_SIZE) / Byte.SIZE;
  53
  54     // Length of each AFI/SAFI array member, in bytes
  55     private static final int PER_AFI_SAFI_SIZE = 4;
  56
  57     private static final short AFI_FLAG_FORWARDING_STATE = 0x80;
  58
  59     private static final int MAX_RESTART_TIME = 4095;
  60
  61     private final AddressFamilyRegistry afiReg;
  62     private final SubsequentAddressFamilyRegistry safiReg;
  63
  64     public GracefulCapabilityHandler(final AddressFamilyRegistry afiReg, final SubsequentAddressFamilyRegistry safiReg) {
  65         this.afiReg = Preconditions.checkNotNull(afiReg);
  66         this.safiReg = Preconditions.checkNotNull(safiReg);
  67     }
  68
  69     @Override
  70     public void serializeCapability(final CParameters capability, final ByteBuf byteAggregator) {
  71         Preconditions.checkArgument(capability instanceof GracefulRestartCase);
  72         final GracefulRestartCapability grace = ((GracefulRestartCase) capability).getGracefulRestartCapability();
  73         final List<Tables> tables = grace.getTables();
  74         final int tablesSize  = (tables != null) ? tables.size() : 0;
  75         final ByteBuf bytes = Unpooled.buffer(HEADER_SIZE + (PER_AFI_SAFI_SIZE * tablesSize));
  76
  77         int timeval = 0;
  78         Integer time = grace.getRestartTime();
  79         if (time == null) {
  80             time = 0;
  81         }
  82         Preconditions.checkArgument(time >= 0 && time <= MAX_RESTART_TIME, "Restart time is " + time);
  83         timeval = time;
  84         final RestartFlags flags = grace.getRestartFlags();
  85         if (flags != null && flags.isRestartState()) {
  86             writeUnsignedShort(RESTART_FLAG_STATE | timeval, bytes);
  87         } else {
  88             writeUnsignedShort(timeval, bytes);
  89         }
  90
  91         if (tables != null) {
  92             for (final Tables t : tables) {
  93                 final Class<? extends AddressFamily> afi = t.getAfi();
  94                 final Integer afival = this.afiReg.numberForClass(afi);
  95                 Preconditions.checkArgument(afival != null, "Unhandled address family " + afi);
  96                 bytes.writeShort(afival);
  97
  98                 final Class<? extends SubsequentAddressFamily> safi = t.getSafi();
  99                 final Integer safival = this.safiReg.numberForClass(safi);
 100                 Preconditions.checkArgument(safival != null, "Unhandled subsequent address family " + safi);
 101                 bytes.writeByte(safival);
 102
 103                 if (t.getAfiFlags() != null && t.getAfiFlags().isForwardingState()) {
 104                     bytes.writeByte(AFI_FLAG_FORWARDING_STATE);
 105                 } else {
 106                     bytes.writeZero(1);
 107                 }
 108             }
 109         }
 110         CapabilityUtil.formatCapability(CODE, bytes, byteAggregator);
 111     }
 112
 113     @Override
 114     public CParameters parseCapability(final ByteBuf buffer) throws BGPDocumentedException, BGPParsingException {
 115         final GracefulRestartCapabilityBuilder cb = new GracefulRestartCapabilityBuilder();
 116
 117         final int flagBits = (buffer.getByte(0) >> RESTART_FLAGS_SIZE);
 118         cb.setRestartFlags(new RestartFlags((flagBits & Byte.SIZE) != 0));
 119
 120         final int timer = ((buffer.readUnsignedByte() & TIMER_TOPBITS_MASK) << RESTART_FLAGS_SIZE) + buffer.readUnsignedByte();
 121         cb.setRestartTime(timer);
 122
 123         final List<Tables> tables = new ArrayList<>();
 124         while (buffer.readableBytes() != 0) {
 125             final int afiVal = buffer.readShort();
 126             final Class<? extends AddressFamily> afi = this.afiReg.classForFamily(afiVal);
 127             if (afi == null) {
 128                 LOG.debug("Ignoring GR capability for unknown address family {}", afiVal);
 129                 buffer.skipBytes(PER_AFI_SAFI_SIZE - 2);
 130                 continue;
 131             }
 132             final int safiVal = buffer.readUnsignedByte();
 133             final Class<? extends SubsequentAddressFamily> safi = this.safiReg.classForFamily(safiVal);
 134             if (safi == null) {
 135                 LOG.debug("Ignoring GR capability for unknown subsequent address family {}", safiVal);
 136                 buffer.skipBytes(1);
 137                 continue;
 138             }
 139             final int flags = buffer.readUnsignedByte();
 140             tables.add(new TablesBuilder().setAfi(afi).setSafi(safi).setAfiFlags(new AfiFlags((flags & AFI_FLAG_FORWARDING_STATE) != 0)).build());
 141         }
 142         cb.setTables(tables);
 143         return new GracefulRestartCaseBuilder().setGracefulRestartCapability(cb.build()).build();
 144     }
 145 }