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
  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.rev200120.open.message.bgp.parameters.optional.capabilities.CParameters;
  25 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev200120.open.message.bgp.parameters.optional.capabilities.CParametersBuilder;
  26 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.CParameters1;
  27 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.CParameters1Builder;
  28 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.mp.capabilities.GracefulRestartCapability;
  29 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.mp.capabilities.GracefulRestartCapability.RestartFlags;
  30 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.mp.capabilities.GracefulRestartCapabilityBuilder;
  31 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.mp.capabilities.graceful.restart.capability.Tables;
  32 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.mp.capabilities.graceful.restart.capability.Tables.AfiFlags;
  33 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.mp.capabilities.graceful.restart.capability.TablesBuilder;
  34 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev200120.AddressFamily;
  35 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev200120.SubsequentAddressFamily;
  36 import org.opendaylight.yangtools.yang.common.Uint16;
  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,
  67             final SubsequentAddressFamilyRegistry safiReg) {
  68         this.afiReg = requireNonNull(afiReg);
  69         this.safiReg = requireNonNull(safiReg);
  70     }
  71
  72     private void serializeTables(final List<Tables> tables, final ByteBuf bytes) {
  73         if (tables == null) {
  74             return;
  75         }
  76         for (final Tables t : tables) {
  77             final Class<? extends AddressFamily> afi = t.getAfi();
  78             final Integer afival = this.afiReg.numberForClass(afi);
  79             Preconditions.checkArgument(afival != null, "Unhandled address family " + afi);
  80             bytes.writeShort(afival);
  81             final Class<? extends SubsequentAddressFamily> safi = t.getSafi();
  82             final Integer safival = this.safiReg.numberForClass(safi);
  83             Preconditions.checkArgument(safival != null, "Unhandled subsequent address family " + safi);
  84             bytes.writeByte(safival);
  85             if (t.getAfiFlags() != null && t.getAfiFlags().isForwardingState()) {
  86                 bytes.writeByte(AFI_FLAG_FORWARDING_STATE);
  87             } else {
  88                 bytes.writeByte(0);
  89             }
  90         }
  91     }
  92
  93     private ByteBuf serializeCapability(final GracefulRestartCapability grace) {
  94         final List<Tables> tables = grace.getTables();
  95         final int tablesSize = tables != null ? tables.size() : 0;
  96         final ByteBuf bytes = Unpooled.buffer(HEADER_SIZE + PER_AFI_SAFI_SIZE * tablesSize);
  97         Uint16 time = grace.getRestartTime();
  98         if (time == null) {
  99             time = Uint16.ZERO;
 100         }
 101         final int timeval = time.toJava();
 102         Preconditions.checkArgument(timeval >= 0 && timeval <= MAX_RESTART_TIME, "Restart time is " + time);
 103         final GracefulRestartCapability.RestartFlags flags = grace.getRestartFlags();
 104         if (flags != null && flags.isRestartState()) {
 105             bytes.writeShort(RESTART_FLAG_STATE | timeval);
 106         } else {
 107             bytes.writeShort(timeval);
 108         }
 109         serializeTables(tables, bytes);
 110         return bytes;
 111     }
 112
 113     @Override
 114     public void serializeCapability(final CParameters capability, final ByteBuf byteAggregator) {
 115         final CParameters1 aug = capability.augmentation(CParameters1.class);
 116         if (aug == null) {
 117             return;
 118         }
 119         final GracefulRestartCapability grace = aug.getGracefulRestartCapability();
 120         if (grace != null) {
 121             final ByteBuf bytes = serializeCapability(grace);
 122             CapabilityUtil.formatCapability(CODE, bytes, byteAggregator);
 123         }
 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)
 154                 .setAfiFlags(new AfiFlags((flags & AFI_FLAG_FORWARDING_STATE) != 0)).build());
 155         }
 156         cb.setTables(tables);
 157         return new CParametersBuilder().addAugmentation(CParameters1.class, new CParameters1Builder()
 158             .setGracefulRestartCapability(cb.build()).build()).build();
 159     }
 160 }