Priyanka B | 965d269 | 2015-10-14 15:25:31 +0530 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2015 Open Networking Laboratory |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | package org.onosproject.bgpio.protocol.ver4; |
| 17 | |
| 18 | import java.util.LinkedList; |
| 19 | import java.util.List; |
| 20 | |
| 21 | import org.jboss.netty.buffer.ChannelBuffer; |
| 22 | import org.onosproject.bgpio.exceptions.BGPParseException; |
| 23 | import org.onosproject.bgpio.types.As4Path; |
| 24 | import org.onosproject.bgpio.types.AsPath; |
| 25 | import org.onosproject.bgpio.types.BGPErrorType; |
| 26 | import org.onosproject.bgpio.types.BGPValueType; |
| 27 | import org.onosproject.bgpio.types.LocalPref; |
| 28 | import org.onosproject.bgpio.types.Med; |
| 29 | import org.onosproject.bgpio.types.NextHop; |
| 30 | import org.onosproject.bgpio.types.Origin; |
| 31 | import org.onosproject.bgpio.util.UnSupportedAttribute; |
| 32 | import org.onosproject.bgpio.util.Validation; |
| 33 | import org.slf4j.Logger; |
| 34 | import org.slf4j.LoggerFactory; |
| 35 | |
| 36 | import com.google.common.base.MoreObjects; |
| 37 | |
| 38 | /** |
| 39 | * Provides Implementation of BGP Path Attribute. |
| 40 | */ |
| 41 | public class BgpPathAttributes { |
| 42 | |
| 43 | /* Path attribute: |
| 44 | <attribute type, attribute length, attribute value> |
| 45 | |
| 46 | 0 1 |
| 47 | 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 |
| 48 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 49 | | Attr. Flags |Attr. Type Code| |
| 50 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 51 | REFERENCE : RFC 4271 |
| 52 | */ |
| 53 | protected static final Logger log = LoggerFactory.getLogger(BgpPathAttributes.class); |
| 54 | |
| 55 | public static final int LINK_STATE_ATTRIBUTE_TYPE = 50; |
| 56 | public static final int MPREACHNLRI_TYPE = 14; |
| 57 | public static final int MPUNREACHNLRI_TYPE = 15; |
| 58 | |
| 59 | private final List<BGPValueType> pathAttribute; |
| 60 | |
| 61 | /** |
| 62 | * Initialize parameter. |
| 63 | */ |
| 64 | public BgpPathAttributes() { |
| 65 | this.pathAttribute = null; |
| 66 | } |
| 67 | |
| 68 | /** |
| 69 | * Constructor to initialize parameters for BGP path attributes. |
| 70 | * |
| 71 | * @param pathAttribute list of path attributes |
| 72 | */ |
| 73 | public BgpPathAttributes(List<BGPValueType> pathAttribute) { |
| 74 | this.pathAttribute = pathAttribute; |
| 75 | } |
| 76 | |
| 77 | /** |
| 78 | * Returns list of path attributes. |
| 79 | * |
| 80 | * @return list of path attributes |
| 81 | */ |
| 82 | public List<BGPValueType> pathAttributes() { |
| 83 | return this.pathAttribute; |
| 84 | } |
| 85 | |
| 86 | /** |
| 87 | * Reads from channelBuffer and parses BGP path attributes. |
| 88 | * |
| 89 | * @param cb channelBuffer |
| 90 | * @return object of BgpPathAttributes |
| 91 | * @throws BGPParseException while parsing BGP path attributes |
| 92 | */ |
| 93 | public static BgpPathAttributes read(ChannelBuffer cb) |
| 94 | throws BGPParseException { |
| 95 | |
| 96 | BGPValueType pathAttribute = null; |
| 97 | List<BGPValueType> pathAttributeList = new LinkedList<>(); |
| 98 | boolean isOrigin = false; |
| 99 | boolean isAsPath = false; |
| 100 | boolean isNextHop = false; |
| 101 | boolean isMpReach = false; |
| 102 | boolean isMpUnReach = false; |
| 103 | while (cb.readableBytes() > 0) { |
| 104 | cb.markReaderIndex(); |
| 105 | byte flags = cb.readByte(); |
| 106 | byte typeCode = cb.readByte(); |
| 107 | cb.resetReaderIndex(); |
| 108 | switch (typeCode) { |
| 109 | case Origin.ORIGIN_TYPE: |
| 110 | pathAttribute = Origin.read(cb); |
| 111 | isOrigin = ((Origin) pathAttribute).isOriginSet(); |
| 112 | break; |
| 113 | case AsPath.ASPATH_TYPE: |
| 114 | pathAttribute = AsPath.read(cb); |
| 115 | isAsPath = ((AsPath) pathAttribute).isaspathSet(); |
| 116 | break; |
| 117 | case As4Path.AS4PATH_TYPE: |
| 118 | pathAttribute = As4Path.read(cb); |
| 119 | break; |
| 120 | case NextHop.NEXTHOP_TYPE: |
| 121 | pathAttribute = NextHop.read(cb); |
| 122 | isNextHop = ((NextHop) pathAttribute).isNextHopSet(); |
| 123 | break; |
| 124 | case Med.MED_TYPE: |
| 125 | pathAttribute = Med.read(cb); |
| 126 | break; |
| 127 | case LocalPref.LOCAL_PREF_TYPE: |
| 128 | pathAttribute = LocalPref.read(cb); |
| 129 | break; |
| 130 | case MPREACHNLRI_TYPE: |
| 131 | //TODO: To be merged later |
| 132 | break; |
| 133 | case MPUNREACHNLRI_TYPE: |
| 134 | //TODO: To be merged later |
| 135 | break; |
| 136 | case LINK_STATE_ATTRIBUTE_TYPE: |
| 137 | //TODO: To be merged later |
| 138 | break; |
| 139 | default: |
| 140 | //skip bytes for unsupported attribute types |
| 141 | UnSupportedAttribute.read(cb); |
| 142 | } |
| 143 | pathAttributeList.add(pathAttribute); |
| 144 | } |
| 145 | |
| 146 | checkMandatoryAttr(isOrigin, isAsPath, isNextHop, isMpReach, isMpUnReach); |
| 147 | //TODO:if mp_reach or mp_unreach not present ignore the packet |
| 148 | return new BgpPathAttributes(pathAttributeList); |
| 149 | } |
| 150 | |
| 151 | /** |
| 152 | * Checks mandatory attributes are presents, if not present throws exception. |
| 153 | * |
| 154 | * @param isOrigin say whether origin attribute is present |
| 155 | * @param isAsPath say whether aspath attribute is present |
| 156 | * @param isNextHop say whether nexthop attribute is present |
| 157 | * @param isMpReach say whether mpreach attribute is present |
| 158 | * @param isMpUnReach say whether mpunreach attribute is present |
| 159 | * @throws BGPParseException if mandatory path attribute is not present |
| 160 | */ |
| 161 | public static void checkMandatoryAttr(boolean isOrigin, boolean isAsPath, |
| 162 | boolean isNextHop, boolean isMpReach, boolean isMpUnReach) |
| 163 | throws BGPParseException { |
| 164 | if (!isOrigin) { |
| 165 | log.debug("Mandatory Attributes not Present"); |
| 166 | Validation.validateType(BGPErrorType.UPDATE_MESSAGE_ERROR, |
| 167 | BGPErrorType.MISSING_WELLKNOWN_ATTRIBUTE, |
| 168 | Origin.ORIGIN_TYPE); |
| 169 | } |
| 170 | if (!isAsPath) { |
| 171 | log.debug("Mandatory Attributes not Present"); |
| 172 | Validation.validateType(BGPErrorType.UPDATE_MESSAGE_ERROR, |
| 173 | BGPErrorType.MISSING_WELLKNOWN_ATTRIBUTE, |
| 174 | AsPath.ASPATH_TYPE); |
| 175 | } |
| 176 | if (!isMpUnReach && !isMpReach && !isNextHop) { |
| 177 | log.debug("Mandatory Attributes not Present"); |
| 178 | Validation.validateType(BGPErrorType.UPDATE_MESSAGE_ERROR, |
| 179 | BGPErrorType.MISSING_WELLKNOWN_ATTRIBUTE, |
| 180 | NextHop.NEXTHOP_TYPE); |
| 181 | } |
| 182 | } |
| 183 | |
| 184 | @Override |
| 185 | public String toString() { |
| 186 | return MoreObjects.toStringHelper(getClass()) |
| 187 | .add("pathAttribute", pathAttribute) |
| 188 | .toString(); |
| 189 | } |
| 190 | } |