bgp/parser-impl/src/main/java/org/opendaylight/protocol/bgp/parser/impl/message/update/CommunitiesParser.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
   9 package org.opendaylight.protocol.bgp.parser.impl.message.update;
  10
  11 import java.util.Arrays;
  12
  13 import org.opendaylight.protocol.bgp.parser.BGPDocumentedException;
  14 import org.opendaylight.protocol.bgp.parser.BGPError;
  15 import org.opendaylight.protocol.bgp.parser.impl.CommunityUtil;
  16 import org.opendaylight.protocol.concepts.Ipv4Util;
  17 import org.opendaylight.protocol.util.ByteArray;
  18 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev100924.AsNumber;
  19 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.Community;
  20 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.extended.community.ExtendedCommunity;
  21 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.extended.community.extended.community.CAsSpecificExtendedCommunityBuilder;
  22 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.extended.community.extended.community.CInet4SpecificExtendedCommunityBuilder;
  23 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.extended.community.extended.community.COpaqueExtendedCommunityBuilder;
  24 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.extended.community.extended.community.CRouteOriginExtendedCommunityBuilder;
  25 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.extended.community.extended.community.CRouteTargetExtendedCommunityBuilder;
  26 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.extended.community.extended.community.c.as.specific.extended.community.AsSpecificExtendedCommunityBuilder;
  27 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.extended.community.extended.community.c.inet4.specific.extended.community.Inet4SpecificExtendedCommunityBuilder;
  28 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.extended.community.extended.community.c.opaque.extended.community.OpaqueExtendedCommunityBuilder;
  29 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.extended.community.extended.community.c.route.origin.extended.community.RouteOriginExtendedCommunityBuilder;
  30 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.extended.community.extended.community.c.route.target.extended.community.RouteTargetExtendedCommunityBuilder;
  31
  32 import com.google.common.annotations.VisibleForTesting;
  33 import com.google.common.primitives.UnsignedBytes;
  34
  35 /**
  36  * Parser for Extended Communities Path Attribute.
  37  */
  38 public class CommunitiesParser {
  39
  40         public static final int EXTENDED_COMMUNITY_LENGTH = 8; // bytes
  41
  42         public static final int COMMUNITY_LENGTH = 4; // bytes
  43
  44         private static final int TYPE_LENGTH = 2; // bytes
  45
  46         private static final int AS_NUMBER_LENGTH = 2; // bytes
  47
  48         private static final int AS_LOCAL_ADMIN_LENGTH = 4; // bytes
  49
  50         private CommunitiesParser() {
  51
  52         }
  53
  54         /**
  55          * Parse known Community, if unknown, a new one will be created.
  56          *
  57          * @param bytes byte array to be parsed
  58          * @return new Community
  59          * @throws BGPDocumentedException
  60          */
  61         static Community parseCommunity(final byte[] bytes) throws BGPDocumentedException {
  62                 if (bytes.length != COMMUNITY_LENGTH) {
  63                         throw new BGPDocumentedException("Community with wrong length: " + bytes.length, BGPError.OPT_ATTR_ERROR);
  64                 }
  65                 if (Arrays.equals(bytes, new byte[] { (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0x01 })) {
  66                         return CommunityUtil.NO_EXPORT;
  67                 } else if (Arrays.equals(bytes, new byte[] { (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0x02 })) {
  68                         return CommunityUtil.NO_ADVERTISE;
  69                 } else if (Arrays.equals(bytes, new byte[] { (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0x03 })) {
  70                         return CommunityUtil.NO_EXPORT_SUBCONFED;
  71                 }
  72                 return CommunityUtil.create((ByteArray.bytesToLong(Arrays.copyOfRange(bytes, 0, AS_NUMBER_LENGTH))),
  73                                 ByteArray.bytesToInt(Arrays.copyOfRange(bytes, AS_NUMBER_LENGTH, AS_NUMBER_LENGTH + AS_NUMBER_LENGTH)));
  74         }
  75
  76         /**
  77          * Parse Extended Community according to their type.
  78          *
  79          * @param bytes byte array to be parsed
  80          * @return new Specific Extended Community
  81          * @throws BGPDocumentedException if the type is not recognized
  82          */
  83         @VisibleForTesting
  84         public static ExtendedCommunity parseExtendedCommunity(final byte[] bytes) throws BGPDocumentedException {
  85                 final int type = UnsignedBytes.toInt(bytes[0]);
  86                 final int subType = UnsignedBytes.toInt(bytes[1]);
  87                 final byte[] value = ByteArray.subByte(bytes, TYPE_LENGTH, bytes.length - TYPE_LENGTH);
  88
  89                 switch (type) {
  90                 case 0:
  91                         if (subType == 2) {
  92                                 return new CRouteTargetExtendedCommunityBuilder().setRouteTargetExtendedCommunity(
  93                                                 new RouteTargetExtendedCommunityBuilder().setGlobalAdministrator(
  94                                                                 new AsNumber(ByteArray.bytesToLong(ByteArray.subByte(value, 0, AS_NUMBER_LENGTH)))).setLocalAdministrator(
  95                                                                                 ByteArray.subByte(value, AS_NUMBER_LENGTH, AS_LOCAL_ADMIN_LENGTH)).build()).build();
  96                         } else if (subType == 3) {
  97                                 return new CRouteOriginExtendedCommunityBuilder().setRouteOriginExtendedCommunity(
  98                                                 new RouteOriginExtendedCommunityBuilder().setGlobalAdministrator(
  99                                                                 new AsNumber(ByteArray.bytesToLong(ByteArray.subByte(value, 0, AS_NUMBER_LENGTH)))).setLocalAdministrator(
 100                                                                                 ByteArray.subByte(value, AS_NUMBER_LENGTH, AS_LOCAL_ADMIN_LENGTH)).build()).build();
 101                         } else {
 102                                 return new CAsSpecificExtendedCommunityBuilder().setAsSpecificExtendedCommunity(
 103                                                 new AsSpecificExtendedCommunityBuilder().setTransitive(false).setGlobalAdministrator(
 104                                                                 new AsNumber(ByteArray.bytesToLong(ByteArray.subByte(value, 0, AS_NUMBER_LENGTH)))).setLocalAdministrator(
 105                                                                                 ByteArray.subByte(value, AS_NUMBER_LENGTH, AS_LOCAL_ADMIN_LENGTH)).build()).build();
 106                         }
 107                 case 40: // 01000000
 108                         return new CAsSpecificExtendedCommunityBuilder().setAsSpecificExtendedCommunity(
 109                                         new AsSpecificExtendedCommunityBuilder().setTransitive(true).setGlobalAdministrator(
 110                                                         new AsNumber(ByteArray.bytesToLong(ByteArray.subByte(value, 0, AS_NUMBER_LENGTH)))).setLocalAdministrator(
 111                                                                         ByteArray.subByte(value, AS_NUMBER_LENGTH, AS_LOCAL_ADMIN_LENGTH)).build()).build();
 112                 case 2:
 113                         if (subType == 2) {
 114                                 return new CRouteTargetExtendedCommunityBuilder().setRouteTargetExtendedCommunity(
 115                                                 new RouteTargetExtendedCommunityBuilder().setGlobalAdministrator(
 116                                                                 new AsNumber(ByteArray.bytesToLong(ByteArray.subByte(value, 0, AS_NUMBER_LENGTH)))).setLocalAdministrator(
 117                                                                                 ByteArray.subByte(value, AS_NUMBER_LENGTH, AS_LOCAL_ADMIN_LENGTH)).build()).build();
 118                         } else if (subType == 3) {
 119                                 return new CRouteOriginExtendedCommunityBuilder().setRouteOriginExtendedCommunity(
 120                                                 new RouteOriginExtendedCommunityBuilder().setGlobalAdministrator(
 121                                                                 new AsNumber(ByteArray.bytesToLong(ByteArray.subByte(value, 0, AS_NUMBER_LENGTH)))).setLocalAdministrator(
 122                                                                                 ByteArray.subByte(value, AS_NUMBER_LENGTH, AS_LOCAL_ADMIN_LENGTH)).build()).build();
 123                         } else {
 124                                 throw new BGPDocumentedException("Could not parse Extended Community subtype: " + subType, BGPError.OPT_ATTR_ERROR);
 125                         }
 126                 case 1:
 127                         if (subType == 2) {
 128                                 return new CRouteTargetExtendedCommunityBuilder().setRouteTargetExtendedCommunity(
 129                                                 new RouteTargetExtendedCommunityBuilder().setGlobalAdministrator(
 130                                                                 new AsNumber(ByteArray.bytesToLong(ByteArray.subByte(value, 0, AS_NUMBER_LENGTH)))).setLocalAdministrator(
 131                                                                                 ByteArray.subByte(value, AS_NUMBER_LENGTH, AS_LOCAL_ADMIN_LENGTH)).build()).build();
 132                         } else if (subType == 3) {
 133                                 return new CRouteOriginExtendedCommunityBuilder().setRouteOriginExtendedCommunity(
 134                                                 new RouteOriginExtendedCommunityBuilder().setGlobalAdministrator(
 135                                                                 new AsNumber(ByteArray.bytesToLong(ByteArray.subByte(value, 0, AS_NUMBER_LENGTH)))).setLocalAdministrator(
 136                                                                                 ByteArray.subByte(value, AS_NUMBER_LENGTH, AS_LOCAL_ADMIN_LENGTH)).build()).build();
 137                         } else {
 138                                 return new CInet4SpecificExtendedCommunityBuilder().setInet4SpecificExtendedCommunity(
 139                                                 new Inet4SpecificExtendedCommunityBuilder().setTransitive(false).setGlobalAdministrator(
 140                                                                 Ipv4Util.addressForBytes(ByteArray.subByte(value, 0, 4))).setLocalAdministrator(
 141                                                                                 ByteArray.subByte(value, 4, 2)).build()).build();
 142                         }
 143                 case 41: // 01000001
 144                         return new CInet4SpecificExtendedCommunityBuilder().setInet4SpecificExtendedCommunity(
 145                                         new Inet4SpecificExtendedCommunityBuilder().setTransitive(true).setGlobalAdministrator(
 146                                                         Ipv4Util.addressForBytes(ByteArray.subByte(value, 0, 4))).setLocalAdministrator(ByteArray.subByte(value, 4, 2)).build()).build();
 147                 case 3:
 148                         return new COpaqueExtendedCommunityBuilder().setOpaqueExtendedCommunity(
 149                                         new OpaqueExtendedCommunityBuilder().setTransitive(false).setValue(value).build()).build();
 150                 case 43: // 01000011
 151                         return new COpaqueExtendedCommunityBuilder().setOpaqueExtendedCommunity(
 152                                         new OpaqueExtendedCommunityBuilder().setTransitive(true).setValue(value).build()).build();
 153                 default:
 154                         throw new BGPDocumentedException("Could not parse Extended Community type: " + type, BGPError.OPT_ATTR_ERROR);
 155                 }
 156         }
 157 }