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.message.bgp.parameters.optional.capabilities.CParameters;
  25 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.message.bgp.parameters.optional.capabilities.CParametersBuilder;
  26 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.CParameters1;
  27 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.CParameters1Builder;
  28 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.mp.capabilities.GracefulRestartCapability;
  29 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.mp.capabilities.GracefulRestartCapability.RestartFlags;
  30 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.mp.capabilities.GracefulRestartCapabilityBuilder;
  31 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.mp.capabilities.graceful.restart.capability.Tables;
  32 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.mp.capabilities.graceful.restart.capability.Tables.AfiFlags;
  33 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.mp.capabilities.graceful.restart.capability.TablesBuilder;
  34 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.AddressFamily;
  35 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.SubsequentAddressFamily;
  36 import org.slf4j.Logger;
  37 import org.slf4j.LoggerFactory;
  38
  39 public final class GracefulCapabilityHandler implements CapabilityParser, CapabilitySerializer {
  40     public static final int CODE = 64;
  41
  42     private static final Logger LOG = LoggerFactory.getLogger(GracefulCapabilityHandler.class);
  43
  44     // Restart flag size, in bits
  45     private static final int RESTART_FLAGS_SIZE = 4;
  46     private static final int RESTART_FLAG_STATE = 0x8000;
  47
  48     // Restart timer size, in bits
  49     private static final int TIMER_SIZE = 12;
  50     private static final int TIMER_TOPBITS_MASK = 0x0F;
  51
  52     // Size of the capability header
  53     private static final int HEADER_SIZE = (RESTART_FLAGS_SIZE + TIMER_SIZE) / Byte.SIZE;
  54
  55     // Length of each AFI/SAFI array member, in bytes
  56     private static final int PER_AFI_SAFI_SIZE = 4;
  57
  58     private static final short AFI_FLAG_FORWARDING_STATE = 0x80;
  59
  60     private static final int MAX_RESTART_TIME = 4095;
  61
  62     private final AddressFamilyRegistry afiReg;
  63     private final SubsequentAddressFamilyRegistry safiReg;
  64
  65     public GracefulCapabilityHandler(final AddressFamilyRegistry afiReg, final SubsequentAddressFamilyRegistry safiReg) {
  66         this.afiReg = Preconditions.checkNotNull(afiReg);
  67         this.safiReg = Preconditions.checkNotNull(safiReg);
  68     }
  69
  70     private void serializeTables(final List<Tables> tables, final ByteBuf bytes) {
  71         if (tables == null) {
  72             return;
  73         }
  74         for (final Tables t : tables) {
  75             final Class<? extends AddressFamily> afi = t.getAfi();
  76             final Integer afival = this.afiReg.numberForClass(afi);
  77             Preconditions.checkArgument(afival != null, "Unhandled address family " + afi);
  78             bytes.writeShort(afival);
  79             final Class<? extends SubsequentAddressFamily> safi = t.getSafi();
  80             final Integer safival = this.safiReg.numberForClass(safi);
  81             Preconditions.checkArgument(safival != null, "Unhandled subsequent address family " + safi);
  82             bytes.writeByte(safival);
  83             if (t.getAfiFlags() != null && t.getAfiFlags().isForwardingState()) {
  84                 bytes.writeByte(AFI_FLAG_FORWARDING_STATE);
  85             } else {
  86                 bytes.writeZero(1);
  87             }
  88         }
  89     }
  90
  91     private ByteBuf serializeCapability(final GracefulRestartCapability grace) {
  92         final List<Tables> tables = grace.getTables();
  93         final int tablesSize = (tables != null) ? tables.size() : 0;
  94         final ByteBuf bytes = Unpooled.buffer(HEADER_SIZE + (PER_AFI_SAFI_SIZE * tablesSize));
  95         int timeval = 0;
  96         Integer time = grace.getRestartTime();
  97         if (time == null) {
  98             time = 0;
  99         }
 100         Preconditions.checkArgument(time >= 0 && time <= MAX_RESTART_TIME, "Restart time is " + time);
 101         timeval = time;
 102         final GracefulRestartCapability.RestartFlags flags = grace.getRestartFlags();
 103         if (flags != null && flags.isRestartState()) {
 104             writeUnsignedShort(RESTART_FLAG_STATE | timeval, bytes);
 105         } else {
 106             writeUnsignedShort(timeval, bytes);
 107         }
 108         serializeTables(tables, bytes);
 109         return bytes;
 110     }
 111
 112     @Override
 113     public void serializeCapability(final CParameters capability, final ByteBuf byteAggregator) {
 114         if (capability.getAugmentation(CParameters1.class) == null
 115             || capability.getAugmentation(CParameters1.class).getGracefulRestartCapability() == null) {
 116             return;
 117         }
 118         final GracefulRestartCapability grace = capability.getAugmentation(CParameters1.class).getGracefulRestartCapability();
 119
 120         final ByteBuf bytes = serializeCapability(grace);
 121
 122         CapabilityUtil.formatCapability(CODE, bytes, byteAggregator);
 123     }
 124
 125     @Override
 126     public CParameters parseCapability(final ByteBuf buffer) throws BGPDocumentedException, BGPParsingException {
 127         final GracefulRestartCapabilityBuilder cb = new GracefulRestartCapabilityBuilder();
 128
 129         final int flagBits = (buffer.getByte(0) >> RESTART_FLAGS_SIZE);
 130         cb.setRestartFlags(new RestartFlags((flagBits & Byte.SIZE) != 0));
 131
 132         final int timer = ((buffer.readUnsignedByte() & TIMER_TOPBITS_MASK) << RESTART_FLAGS_SIZE) + buffer.readUnsignedByte();
 133         cb.setRestartTime(timer);
 134
 135         final List<Tables> tables = new ArrayList<>();
 136         while (buffer.readableBytes() != 0) {
 137             final int afiVal = buffer.readShort();
 138             final Class<? extends AddressFamily> afi = this.afiReg.classForFamily(afiVal);
 139             if (afi == null) {
 140                 LOG.debug("Ignoring GR capability for unknown address family {}", afiVal);
 141                 buffer.skipBytes(PER_AFI_SAFI_SIZE - 2);
 142                 continue;
 143             }
 144             final int safiVal = buffer.readUnsignedByte();
 145             final Class<? extends SubsequentAddressFamily> safi = this.safiReg.classForFamily(safiVal);
 146             if (safi == null) {
 147                 LOG.debug("Ignoring GR capability for unknown subsequent address family {}", safiVal);
 148                 buffer.skipBytes(1);
 149                 continue;
 150             }
 151             final int flags = buffer.readUnsignedByte();
 152             tables.add(new TablesBuilder().setAfi(afi).setSafi(safi).setAfiFlags(new AfiFlags((flags & AFI_FLAG_FORWARDING_STATE) != 0)).build());
 153         }
 154         cb.setTables(tables);
 155         return new CParametersBuilder().addAugmentation(CParameters1.class, new CParameters1Builder()
 156             .setGracefulRestartCapability(cb.build()).build()).build();
 157     }
 158 }