[Emu] [ONOS-2601] Implement BGP Update protocol message and parse all basic path attributes.
Change-Id: I5d4abb58e3484f56e629ab97cb0995ab03a5b235
diff --git a/bgp/bgpio/src/main/java/org/onosproject/bgpio/protocol/ver4/BgpPathAttributes.java b/bgp/bgpio/src/main/java/org/onosproject/bgpio/protocol/ver4/BgpPathAttributes.java
new file mode 100644
index 0000000..08fea4c
--- /dev/null
+++ b/bgp/bgpio/src/main/java/org/onosproject/bgpio/protocol/ver4/BgpPathAttributes.java
@@ -0,0 +1,190 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.bgpio.protocol.ver4;
+
+import java.util.LinkedList;
+import java.util.List;
+
+import org.jboss.netty.buffer.ChannelBuffer;
+import org.onosproject.bgpio.exceptions.BGPParseException;
+import org.onosproject.bgpio.types.As4Path;
+import org.onosproject.bgpio.types.AsPath;
+import org.onosproject.bgpio.types.BGPErrorType;
+import org.onosproject.bgpio.types.BGPValueType;
+import org.onosproject.bgpio.types.LocalPref;
+import org.onosproject.bgpio.types.Med;
+import org.onosproject.bgpio.types.NextHop;
+import org.onosproject.bgpio.types.Origin;
+import org.onosproject.bgpio.util.UnSupportedAttribute;
+import org.onosproject.bgpio.util.Validation;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.base.MoreObjects;
+
+/**
+ * Provides Implementation of BGP Path Attribute.
+ */
+public class BgpPathAttributes {
+
+ /* Path attribute:
+ <attribute type, attribute length, attribute value>
+
+ 0 1
+ 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ | Attr. Flags |Attr. Type Code|
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ REFERENCE : RFC 4271
+ */
+ protected static final Logger log = LoggerFactory.getLogger(BgpPathAttributes.class);
+
+ public static final int LINK_STATE_ATTRIBUTE_TYPE = 50;
+ public static final int MPREACHNLRI_TYPE = 14;
+ public static final int MPUNREACHNLRI_TYPE = 15;
+
+ private final List<BGPValueType> pathAttribute;
+
+ /**
+ * Initialize parameter.
+ */
+ public BgpPathAttributes() {
+ this.pathAttribute = null;
+ }
+
+ /**
+ * Constructor to initialize parameters for BGP path attributes.
+ *
+ * @param pathAttribute list of path attributes
+ */
+ public BgpPathAttributes(List<BGPValueType> pathAttribute) {
+ this.pathAttribute = pathAttribute;
+ }
+
+ /**
+ * Returns list of path attributes.
+ *
+ * @return list of path attributes
+ */
+ public List<BGPValueType> pathAttributes() {
+ return this.pathAttribute;
+ }
+
+ /**
+ * Reads from channelBuffer and parses BGP path attributes.
+ *
+ * @param cb channelBuffer
+ * @return object of BgpPathAttributes
+ * @throws BGPParseException while parsing BGP path attributes
+ */
+ public static BgpPathAttributes read(ChannelBuffer cb)
+ throws BGPParseException {
+
+ BGPValueType pathAttribute = null;
+ List<BGPValueType> pathAttributeList = new LinkedList<>();
+ boolean isOrigin = false;
+ boolean isAsPath = false;
+ boolean isNextHop = false;
+ boolean isMpReach = false;
+ boolean isMpUnReach = false;
+ while (cb.readableBytes() > 0) {
+ cb.markReaderIndex();
+ byte flags = cb.readByte();
+ byte typeCode = cb.readByte();
+ cb.resetReaderIndex();
+ switch (typeCode) {
+ case Origin.ORIGIN_TYPE:
+ pathAttribute = Origin.read(cb);
+ isOrigin = ((Origin) pathAttribute).isOriginSet();
+ break;
+ case AsPath.ASPATH_TYPE:
+ pathAttribute = AsPath.read(cb);
+ isAsPath = ((AsPath) pathAttribute).isaspathSet();
+ break;
+ case As4Path.AS4PATH_TYPE:
+ pathAttribute = As4Path.read(cb);
+ break;
+ case NextHop.NEXTHOP_TYPE:
+ pathAttribute = NextHop.read(cb);
+ isNextHop = ((NextHop) pathAttribute).isNextHopSet();
+ break;
+ case Med.MED_TYPE:
+ pathAttribute = Med.read(cb);
+ break;
+ case LocalPref.LOCAL_PREF_TYPE:
+ pathAttribute = LocalPref.read(cb);
+ break;
+ case MPREACHNLRI_TYPE:
+ //TODO: To be merged later
+ break;
+ case MPUNREACHNLRI_TYPE:
+ //TODO: To be merged later
+ break;
+ case LINK_STATE_ATTRIBUTE_TYPE:
+ //TODO: To be merged later
+ break;
+ default:
+ //skip bytes for unsupported attribute types
+ UnSupportedAttribute.read(cb);
+ }
+ pathAttributeList.add(pathAttribute);
+ }
+
+ checkMandatoryAttr(isOrigin, isAsPath, isNextHop, isMpReach, isMpUnReach);
+ //TODO:if mp_reach or mp_unreach not present ignore the packet
+ return new BgpPathAttributes(pathAttributeList);
+ }
+
+ /**
+ * Checks mandatory attributes are presents, if not present throws exception.
+ *
+ * @param isOrigin say whether origin attribute is present
+ * @param isAsPath say whether aspath attribute is present
+ * @param isNextHop say whether nexthop attribute is present
+ * @param isMpReach say whether mpreach attribute is present
+ * @param isMpUnReach say whether mpunreach attribute is present
+ * @throws BGPParseException if mandatory path attribute is not present
+ */
+ public static void checkMandatoryAttr(boolean isOrigin, boolean isAsPath,
+ boolean isNextHop, boolean isMpReach, boolean isMpUnReach)
+ throws BGPParseException {
+ if (!isOrigin) {
+ log.debug("Mandatory Attributes not Present");
+ Validation.validateType(BGPErrorType.UPDATE_MESSAGE_ERROR,
+ BGPErrorType.MISSING_WELLKNOWN_ATTRIBUTE,
+ Origin.ORIGIN_TYPE);
+ }
+ if (!isAsPath) {
+ log.debug("Mandatory Attributes not Present");
+ Validation.validateType(BGPErrorType.UPDATE_MESSAGE_ERROR,
+ BGPErrorType.MISSING_WELLKNOWN_ATTRIBUTE,
+ AsPath.ASPATH_TYPE);
+ }
+ if (!isMpUnReach && !isMpReach && !isNextHop) {
+ log.debug("Mandatory Attributes not Present");
+ Validation.validateType(BGPErrorType.UPDATE_MESSAGE_ERROR,
+ BGPErrorType.MISSING_WELLKNOWN_ATTRIBUTE,
+ NextHop.NEXTHOP_TYPE);
+ }
+ }
+
+ @Override
+ public String toString() {
+ return MoreObjects.toStringHelper(getClass())
+ .add("pathAttribute", pathAttribute)
+ .toString();
+ }
+}