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.opendaylight.yangtools.yang.common.Uint16;
  38 import org.slf4j.Logger;
  39 import org.slf4j.LoggerFactory;
  40
  41 public final class GracefulCapabilityHandler implements CapabilityParser, CapabilitySerializer {
  42     public static final int CODE = 64;
  43
  44     private static final Logger LOG = LoggerFactory.getLogger(GracefulCapabilityHandler.class);
  45
  46     // Restart flag size, in bits
  47     private static final int RESTART_FLAGS_SIZE = 4;
  48     private static final int RESTART_FLAG_STATE = 0x8000;
  49
  50     // Restart timer size, in bits
  51     private static final int TIMER_SIZE = 12;
  52     private static final int TIMER_TOPBITS_MASK = 0x0F;
  53
  54     // Size of the capability header
  55     private static final int HEADER_SIZE = (RESTART_FLAGS_SIZE + TIMER_SIZE) / Byte.SIZE;
  56
  57     // Length of each AFI/SAFI array member, in bytes
  58     private static final int PER_AFI_SAFI_SIZE = 4;
  59
  60     private static final short AFI_FLAG_FORWARDING_STATE = 0x80;
  61
  62     private static final int MAX_RESTART_TIME = 4095;
  63
  64     private final AddressFamilyRegistry afiReg;
  65     private final SubsequentAddressFamilyRegistry safiReg;
  66
  67     public GracefulCapabilityHandler(final AddressFamilyRegistry afiReg,
  68             final SubsequentAddressFamilyRegistry safiReg) {
  69         this.afiReg = requireNonNull(afiReg);
  70         this.safiReg = requireNonNull(safiReg);
  71     }
  72
  73     private void serializeTables(final List<Tables> tables, final ByteBuf bytes) {
  74         if (tables == null) {
  75             return;
  76         }
  77         for (final Tables t : tables) {
  78             final Class<? extends AddressFamily> afi = t.getAfi();
  79             final Integer afival = this.afiReg.numberForClass(afi);
  80             Preconditions.checkArgument(afival != null, "Unhandled address family " + afi);
  81             bytes.writeShort(afival);
  82             final Class<? extends SubsequentAddressFamily> safi = t.getSafi();
  83             final Integer safival = this.safiReg.numberForClass(safi);
  84             Preconditions.checkArgument(safival != null, "Unhandled subsequent address family " + safi);
  85             bytes.writeByte(safival);
  86             if (t.getAfiFlags() != null && t.getAfiFlags().isForwardingState()) {
  87                 bytes.writeByte(AFI_FLAG_FORWARDING_STATE);
  88             } else {
  89                 bytes.writeZero(1);
  90             }
  91         }
  92     }
  93
  94     private ByteBuf serializeCapability(final GracefulRestartCapability grace) {
  95         final List<Tables> tables = grace.getTables();
  96         final int tablesSize = tables != null ? tables.size() : 0;
  97         final ByteBuf bytes = Unpooled.buffer(HEADER_SIZE + PER_AFI_SAFI_SIZE * tablesSize);
  98         Uint16 time = grace.getRestartTime();
  99         if (time == null) {
 100             time = Uint16.ZERO;
 101         }
 102         final int timeval = time.toJava();
 103         Preconditions.checkArgument(timeval >= 0 && timeval <= MAX_RESTART_TIME, "Restart time is " + time);
 104         final GracefulRestartCapability.RestartFlags flags = grace.getRestartFlags();
 105         if (flags != null && flags.isRestartState()) {
 106             writeUnsignedShort(RESTART_FLAG_STATE | timeval, bytes);
 107         } else {
 108             writeUnsignedShort(timeval, bytes);
 109         }
 110         serializeTables(tables, bytes);
 111         return bytes;
 112     }
 113
 114     @Override
 115     public void serializeCapability(final CParameters capability, final ByteBuf byteAggregator) {
 116         final CParameters1 aug = capability.augmentation(CParameters1.class);
 117         if (aug == null) {
 118             return;
 119         }
 120         final GracefulRestartCapability grace = aug.getGracefulRestartCapability();
 121         if (grace != null) {
 122             final ByteBuf bytes = serializeCapability(grace);
 123             CapabilityUtil.formatCapability(CODE, bytes, byteAggregator);
 124         }
 125     }
 126
 127     @Override
 128     public CParameters parseCapability(final ByteBuf buffer) throws BGPDocumentedException, BGPParsingException {
 129         final GracefulRestartCapabilityBuilder cb = new GracefulRestartCapabilityBuilder();
 130
 131         final int flagBits = buffer.getByte(0) >> RESTART_FLAGS_SIZE;
 132         cb.setRestartFlags(new RestartFlags((flagBits & Byte.SIZE) != 0));
 133
 134         final int timer = ((buffer.readUnsignedByte() & TIMER_TOPBITS_MASK) << Byte.SIZE) + buffer.readUnsignedByte();
 135         cb.setRestartTime(timer);
 136
 137         final List<Tables> tables = new ArrayList<>();
 138         while (buffer.readableBytes() != 0) {
 139             final int afiVal = buffer.readShort();
 140             final Class<? extends AddressFamily> afi = this.afiReg.classForFamily(afiVal);
 141             if (afi == null) {
 142                 LOG.debug("Ignoring GR capability for unknown address family {}", afiVal);
 143                 buffer.skipBytes(PER_AFI_SAFI_SIZE - 2);
 144                 continue;
 145             }
 146             final int safiVal = buffer.readUnsignedByte();
 147             final Class<? extends SubsequentAddressFamily> safi = this.safiReg.classForFamily(safiVal);
 148             if (safi == null) {
 149                 LOG.debug("Ignoring GR capability for unknown subsequent address family {}", safiVal);
 150                 buffer.skipBytes(1);
 151                 continue;
 152             }
 153             final int flags = buffer.readUnsignedByte();
 154             tables.add(new TablesBuilder().setAfi(afi).setSafi(safi)
 155                 .setAfiFlags(new AfiFlags((flags & AFI_FLAG_FORWARDING_STATE) != 0)).build());
 156         }
 157         cb.setTables(tables);
 158         return new CParametersBuilder().addAugmentation(CParameters1.class, new CParameters1Builder()
 159             .setGracefulRestartCapability(cb.build()).build()).build();
 160     }
 161 }