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 com.google.common.base.Preconditions;
  11 import com.google.common.primitives.UnsignedBytes;
  12 import io.netty.buffer.ByteBuf;
  13 import io.netty.buffer.Unpooled;
  14 import java.util.ArrayList;
  15 import java.util.List;
  16 import org.opendaylight.protocol.bgp.parser.BGPDocumentedException;
  17 import org.opendaylight.protocol.bgp.parser.BGPParsingException;
  18 import org.opendaylight.protocol.bgp.parser.spi.AddressFamilyRegistry;
  19 import org.opendaylight.protocol.bgp.parser.spi.CapabilityParser;
  20 import org.opendaylight.protocol.bgp.parser.spi.CapabilitySerializer;
  21 import org.opendaylight.protocol.bgp.parser.spi.CapabilityUtil;
  22 import org.opendaylight.protocol.bgp.parser.spi.SubsequentAddressFamilyRegistry;
  23 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.bgp.parameters.optional.capabilities.CParameters;
  24 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.open.bgp.parameters.optional.capabilities.c.parameters.GracefulRestartCase;
  25 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.open.bgp.parameters.optional.capabilities.c.parameters.GracefulRestartCaseBuilder;
  26 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;
  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.RestartFlags;
  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.GracefulRestartCapabilityBuilder;
  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.graceful.restart.capability.Tables;
  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.AfiFlags;
  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.TablesBuilder;
  32 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.AddressFamily;
  33 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.SubsequentAddressFamily;
  34 import org.slf4j.Logger;
  35 import org.slf4j.LoggerFactory;
  36
  37 public final class GracefulCapabilityHandler implements CapabilityParser, CapabilitySerializer {
  38     public static final int CODE = 64;
  39
  40     private static final Logger LOG = LoggerFactory.getLogger(GracefulCapabilityHandler.class);
  41
  42     // Restart flag size, in bits
  43     private static final int RESTART_FLAGS_SIZE = 4;
  44     private static final int RESTART_FLAG_STATE = 0x80;
  45
  46     // Restart timer size, in bits
  47     private static final int TIMER_SIZE = 12;
  48     private static final int TIMER_TOPBITS_MASK = 0x0F;
  49
  50     // Size of the capability header
  51     private static final int HEADER_SIZE = (RESTART_FLAGS_SIZE + TIMER_SIZE) / Byte.SIZE;
  52
  53     // Length of each AFI/SAFI array member, in bytes
  54     private static final int PER_AFI_SAFI_SIZE = 4;
  55
  56     private static final int AFI_FLAG_FORWARDING_STATE = 0x80;
  57
  58     private static final int MAX_RESTART_TIME = 4095;
  59
  60     private final AddressFamilyRegistry afiReg;
  61     private final SubsequentAddressFamilyRegistry safiReg;
  62
  63     public GracefulCapabilityHandler(final AddressFamilyRegistry afiReg, final SubsequentAddressFamilyRegistry safiReg) {
  64         this.afiReg = Preconditions.checkNotNull(afiReg);
  65         this.safiReg = Preconditions.checkNotNull(safiReg);
  66     }
  67
  68     @Override
  69     public void serializeCapability(final CParameters capability, final ByteBuf byteAggregator) {
  70         Preconditions.checkArgument(capability instanceof GracefulRestartCase);
  71         final GracefulRestartCapability grace = ((GracefulRestartCase) capability).getGracefulRestartCapability();
  72         final List<Tables> tables = grace.getTables();
  73
  74         final ByteBuf bytes = Unpooled.buffer(HEADER_SIZE + PER_AFI_SAFI_SIZE * tables.size());
  75
  76         int flagBits = 0;
  77         final RestartFlags flags = grace.getRestartFlags();
  78         if (flags != null && flags.isRestartState()) {
  79             flagBits |= RESTART_FLAG_STATE;
  80         }
  81         int timeval = 0;
  82         final Integer time = grace.getRestartTime();
  83         if (time != null) {
  84             Preconditions.checkArgument(time >= 0 && time <= MAX_RESTART_TIME);
  85             timeval = time;
  86         }
  87         bytes.writeByte(flagBits + timeval / 256);
  88         bytes.writeByte(timeval % 256);
  89
  90         for (final Tables t : tables) {
  91             final Class<? extends AddressFamily> afi = t.getAfi();
  92             final Integer afival = this.afiReg.numberForClass(afi);
  93             Preconditions.checkArgument(afival != null, "Unhandled address family " + afi);
  94
  95             final Class<? extends SubsequentAddressFamily> safi = t.getSafi();
  96             final Integer safival = this.safiReg.numberForClass(safi);
  97             Preconditions.checkArgument(safival != null, "Unhandled subsequent address family " + safi);
  98
  99             bytes.writeShort(afival);
 100             bytes.writeByte(safival);
 101             if (t.getAfiFlags() != null && t.getAfiFlags().isForwardingState()) {
 102                 bytes.writeByte(AFI_FLAG_FORWARDING_STATE);
 103             } else {
 104                 bytes.writeZero(1);
 105             }
 106         }
 107         CapabilityUtil.formatCapability(CODE, bytes,byteAggregator);
 108     }
 109
 110     @Override
 111     public CParameters parseCapability(final ByteBuf buffer) throws BGPDocumentedException, BGPParsingException {
 112         final GracefulRestartCapabilityBuilder cb = new GracefulRestartCapabilityBuilder();
 113
 114         final int flagBits = (buffer.getByte(0) >> RESTART_FLAGS_SIZE);
 115         cb.setRestartFlags(new RestartFlags((flagBits & Byte.SIZE) != 0));
 116
 117         final int timer = ((buffer.readByte() & TIMER_TOPBITS_MASK) << RESTART_FLAGS_SIZE) + UnsignedBytes.toInt(buffer.readByte());
 118         cb.setRestartTime(timer);
 119
 120         final List<Tables> tables = new ArrayList<>();
 121         while (buffer.readableBytes() != 0) {
 122             final int afiVal = buffer.readShort();
 123             final Class<? extends AddressFamily> afi = this.afiReg.classForFamily(afiVal);
 124             if (afi == null) {
 125                 LOG.debug("Ignoring GR capability for unknown address family {}", afiVal);
 126                 buffer.skipBytes(PER_AFI_SAFI_SIZE - 2);
 127                 continue;
 128             }
 129             final int safiVal = UnsignedBytes.toInt(buffer.readByte());
 130             final Class<? extends SubsequentAddressFamily> safi = this.safiReg.classForFamily(safiVal);
 131             if (safi == null) {
 132                 LOG.debug("Ignoring GR capability for unknown subsequent address family {}", safiVal);
 133                 buffer.skipBytes(1);
 134                 continue;
 135             }
 136             final int flags = UnsignedBytes.toInt(buffer.readByte());
 137             tables.add(new TablesBuilder().setAfi(afi).setSafi(safi).setAfiFlags(new AfiFlags((flags & AFI_FLAG_FORWARDING_STATE) != 0)).build());
 138         }
 139         cb.setTables(tables);
 140         return new GracefulRestartCaseBuilder().setGracefulRestartCapability(cb.build()).build();
 141     }
 142 }