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 java.util.ArrayList;
  11 import java.util.List;
  12
  13 import org.opendaylight.protocol.bgp.parser.BGPDocumentedException;
  14 import org.opendaylight.protocol.bgp.parser.BGPParsingException;
  15 import org.opendaylight.protocol.bgp.parser.spi.AddressFamilyRegistry;
  16 import org.opendaylight.protocol.bgp.parser.spi.CapabilityParser;
  17 import org.opendaylight.protocol.bgp.parser.spi.CapabilitySerializer;
  18 import org.opendaylight.protocol.bgp.parser.spi.CapabilityUtil;
  19 import org.opendaylight.protocol.bgp.parser.spi.SubsequentAddressFamilyRegistry;
  20 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.bgp.parameters.CParameters;
  21 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.open.bgp.parameters.c.parameters.GracefulRestartCase;
  22 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.open.bgp.parameters.c.parameters.GracefulRestartCaseBuilder;
  23 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.open.bgp.parameters.c.parameters.graceful.restart._case.GracefulRestartCapability;
  24 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.open.bgp.parameters.c.parameters.graceful.restart._case.GracefulRestartCapability.RestartFlags;
  25 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.open.bgp.parameters.c.parameters.graceful.restart._case.GracefulRestartCapabilityBuilder;
  26 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.open.bgp.parameters.c.parameters.graceful.restart._case.graceful.restart.capability.Tables;
  27 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.open.bgp.parameters.c.parameters.graceful.restart._case.graceful.restart.capability.Tables.AfiFlags;
  28 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.open.bgp.parameters.c.parameters.graceful.restart._case.graceful.restart.capability.TablesBuilder;
  29 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.AddressFamily;
  30 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.SubsequentAddressFamily;
  31 import org.slf4j.Logger;
  32 import org.slf4j.LoggerFactory;
  33
  34 import com.google.common.base.Preconditions;
  35 import com.google.common.primitives.UnsignedBytes;
  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 final AddressFamilyRegistry afiReg;
  59         private final SubsequentAddressFamilyRegistry safiReg;
  60
  61         public GracefulCapabilityHandler(final AddressFamilyRegistry afiReg, final SubsequentAddressFamilyRegistry safiReg) {
  62                 this.afiReg = Preconditions.checkNotNull(afiReg);
  63                 this.safiReg = Preconditions.checkNotNull(safiReg);
  64         }
  65
  66         @Override
  67         public byte[] serializeCapability(final CParameters capability) {
  68                 final GracefulRestartCapability grace = ((GracefulRestartCase) capability).getGracefulRestartCapability();
  69                 final List<Tables> tables = grace.getTables();
  70
  71                 final byte[] bytes = new byte[HEADER_SIZE + PER_AFI_SAFI_SIZE * tables.size()];
  72
  73                 int flagBits = 0;
  74                 final RestartFlags flags = grace.getRestartFlags();
  75                 if (flags != null) {
  76                         if (flags.isRestartState()) {
  77                                 flagBits |= RESTART_FLAG_STATE;
  78                         }
  79                 }
  80                 int timeval = 0;
  81                 final Integer time = grace.getRestartTime();
  82                 if (time != null) {
  83                         Preconditions.checkArgument(time >= 0 && time <= 4095);
  84                         timeval = time;
  85                 }
  86                 bytes[0] = UnsignedBytes.checkedCast(flagBits + timeval / 256);
  87                 bytes[1] = UnsignedBytes.checkedCast(timeval % 256);
  88
  89                 int index = HEADER_SIZE;
  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[index] = UnsignedBytes.checkedCast(afival / 256);
 100                         bytes[index + 1] = UnsignedBytes.checkedCast(afival % 256);
 101                         bytes[index + 2] = UnsignedBytes.checkedCast(safival);
 102                         if (t.getAfiFlags().isForwardingState()) {
 103                                 bytes[index + 3] = UnsignedBytes.checkedCast(AFI_FLAG_FORWARDING_STATE);
 104                         }
 105                         index += PER_AFI_SAFI_SIZE;
 106                 }
 107                 return CapabilityUtil.formatCapability(CODE, bytes);
 108         }
 109
 110         @Override
 111         public CParameters parseCapability(final byte[] bytes) throws BGPDocumentedException, BGPParsingException {
 112                 final GracefulRestartCapabilityBuilder cb = new GracefulRestartCapabilityBuilder();
 113
 114                 final int flagBits = (bytes[0] >> RESTART_FLAGS_SIZE);
 115                 cb.setRestartFlags(new RestartFlags((flagBits & 8) != 0));
 116
 117                 final int timer = ((bytes[0] & TIMER_TOPBITS_MASK) << RESTART_FLAGS_SIZE) + UnsignedBytes.toInt(bytes[1]);
 118                 cb.setRestartTime(timer);
 119
 120                 final List<Tables> tables = new ArrayList<>();
 121                 for (int offset = HEADER_SIZE; offset < bytes.length; offset += PER_AFI_SAFI_SIZE) {
 122                         final int afiVal = UnsignedBytes.toInt(bytes[offset]) * 256 + UnsignedBytes.toInt(bytes[offset + 1]);
 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                                 continue;
 127                         }
 128                         final int safiVal = UnsignedBytes.toInt(bytes[offset + 2]);
 129                         final Class<? extends SubsequentAddressFamily> safi = this.safiReg.classForFamily(safiVal);
 130                         if (safi == null) {
 131                                 LOG.debug("Ignoring GR capability for unknown subsequent address family {}", safiVal);
 132                                 continue;
 133                         }
 134                         final int flags = UnsignedBytes.toInt(bytes[offset + 3]);
 135                         tables.add(new TablesBuilder().setAfi(afi).setSafi(safi).setAfiFlags(new AfiFlags((flags & AFI_FLAG_FORWARDING_STATE) != 0)).build());
 136                 }
 137                 return new GracefulRestartCaseBuilder().setGracefulRestartCapability(cb.build()).build();
 138         }
 139 }