diff options
Diffstat (limited to 'framework/src/onos/protocols/bgp/bgpio/src/main/java/org/onosproject/bgpio/protocol/ver4/BgpUpdateMsgVer4.java')
| -rw-r--r-- | framework/src/onos/protocols/bgp/bgpio/src/main/java/org/onosproject/bgpio/protocol/ver4/BgpUpdateMsgVer4.java | 285 |
1 files changed, 285 insertions, 0 deletions
diff --git a/framework/src/onos/protocols/bgp/bgpio/src/main/java/org/onosproject/bgpio/protocol/ver4/BgpUpdateMsgVer4.java b/framework/src/onos/protocols/bgp/bgpio/src/main/java/org/onosproject/bgpio/protocol/ver4/BgpUpdateMsgVer4.java new file mode 100644 index 00000000..4d6af594 --- /dev/null +++ b/framework/src/onos/protocols/bgp/bgpio/src/main/java/org/onosproject/bgpio/protocol/ver4/BgpUpdateMsgVer4.java @@ -0,0 +1,285 @@ +/* + * 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.onlab.packet.IpPrefix; +import org.onosproject.bgpio.exceptions.BgpParseException; +import org.onosproject.bgpio.protocol.BgpMessageReader; +import org.onosproject.bgpio.protocol.BgpType; +import org.onosproject.bgpio.protocol.BgpUpdateMsg; +import org.onosproject.bgpio.types.BgpErrorType; +import org.onosproject.bgpio.types.BgpHeader; +import org.onosproject.bgpio.util.Validation; +import org.onosproject.bgpio.protocol.BgpVersion; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import com.google.common.base.MoreObjects; + +/** + * BGP Update Message: UPDATE messages are used to transfer routing information + * between BGP peers. The information in the UPDATE message is used by core to + * construct a graph + */ +public class BgpUpdateMsgVer4 implements BgpUpdateMsg { + + /* 0 1 2 3 + 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | + + + + | | + + + + | Marker | + + + + | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Length | Type | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Withdrawn Routes Length (2 octets) | + +-----------------------------------------------------+ + | Withdrawn Routes (variable) | + +-----------------------------------------------------+ + | Total Path Attribute Length (2 octets) | + +-----------------------------------------------------+ + | Path Attributes (variable) | + +-----------------------------------------------------+ + | Network Layer Reachability Information (variable) | + +-----------------------------------------------------+ + REFERENCE : RFC 4271 + */ + + protected static final Logger log = LoggerFactory + .getLogger(BgpUpdateMsgVer4.class); + + public static final byte PACKET_VERSION = 4; + //Withdrawn Routes Length(2) + Total Path Attribute Length(2) + public static final int PACKET_MINIMUM_LENGTH = 4; + public static final int BYTE_IN_BITS = 8; + public static final int MIN_LEN_AFTER_WITHDRW_ROUTES = 2; + public static final int MINIMUM_COMMON_HEADER_LENGTH = 19; + public static final BgpType MSG_TYPE = BgpType.UPDATE; + public static final BgpUpdateMsgVer4.Reader READER = new Reader(); + + private List<IpPrefix> withdrawnRoutes; + private BgpPathAttributes bgpPathAttributes; + private BgpHeader bgpHeader; + private List<IpPrefix> nlri; + + /** + * Constructor to initialize parameters for BGP Update message. + * + * @param bgpHeader in Update message + * @param withdrawnRoutes withdrawn routes + * @param bgpPathAttributes BGP Path attributes + * @param nlri Network Layer Reachability Information + */ + public BgpUpdateMsgVer4(BgpHeader bgpHeader, List<IpPrefix> withdrawnRoutes, + BgpPathAttributes bgpPathAttributes, List<IpPrefix> nlri) { + this.bgpHeader = bgpHeader; + this.withdrawnRoutes = withdrawnRoutes; + this.bgpPathAttributes = bgpPathAttributes; + this.nlri = nlri; + } + + /** + * Reader reads BGP Update Message from the channel buffer. + */ + static class Reader implements BgpMessageReader<BgpUpdateMsg> { + + @Override + public BgpUpdateMsg readFrom(ChannelBuffer cb, BgpHeader bgpHeader) + throws BgpParseException { + + if (cb.readableBytes() != (bgpHeader.getLength() - MINIMUM_COMMON_HEADER_LENGTH)) { + Validation.validateLen(BgpErrorType.UPDATE_MESSAGE_ERROR, + BgpErrorType.BAD_MESSAGE_LENGTH, bgpHeader.getLength()); + } + + LinkedList<IpPrefix> withDrwRoutes = new LinkedList<>(); + LinkedList<IpPrefix> nlri = new LinkedList<>(); + BgpPathAttributes bgpPathAttributes = new BgpPathAttributes(); + // Reading Withdrawn Routes Length + Short withDrwLen = cb.readShort(); + + if (cb.readableBytes() < withDrwLen) { + Validation.validateLen(BgpErrorType.UPDATE_MESSAGE_ERROR, + BgpErrorType.MALFORMED_ATTRIBUTE_LIST, + cb.readableBytes()); + } + ChannelBuffer tempCb = cb.readBytes(withDrwLen); + if (withDrwLen != 0) { + // Parsing WithdrawnRoutes + withDrwRoutes = parseWithdrawnRoutes(tempCb); + } + if (cb.readableBytes() < MIN_LEN_AFTER_WITHDRW_ROUTES) { + log.debug("Bgp Path Attribute len field not present"); + throw new BgpParseException(BgpErrorType.UPDATE_MESSAGE_ERROR, + BgpErrorType.MALFORMED_ATTRIBUTE_LIST, null); + } + + // Reading Total Path Attribute Length + short totPathAttrLen = cb.readShort(); + int len = withDrwLen + totPathAttrLen + PACKET_MINIMUM_LENGTH; + if (len > bgpHeader.getLength()) { + throw new BgpParseException(BgpErrorType.UPDATE_MESSAGE_ERROR, + BgpErrorType.MALFORMED_ATTRIBUTE_LIST, null); + } + if (totPathAttrLen != 0) { + // Parsing BGPPathAttributes + if (cb.readableBytes() < totPathAttrLen) { + Validation + .validateLen(BgpErrorType.UPDATE_MESSAGE_ERROR, + BgpErrorType.MALFORMED_ATTRIBUTE_LIST, + cb.readableBytes()); + } + tempCb = cb.readBytes(totPathAttrLen); + bgpPathAttributes = BgpPathAttributes.read(tempCb); + } + if (cb.readableBytes() > 0) { + // Parsing NLRI + nlri = parseNlri(cb); + } + return new BgpUpdateMsgVer4(bgpHeader, withDrwRoutes, + bgpPathAttributes, nlri); + } + } + + /** + * Parses NLRI from channel buffer. + * + * @param cb channelBuffer + * @return list of IP Prefix + * @throws BgpParseException while parsing NLRI + */ + public static LinkedList<IpPrefix> parseNlri(ChannelBuffer cb) + throws BgpParseException { + LinkedList<IpPrefix> nlri = new LinkedList<>(); + while (cb.readableBytes() > 0) { + int length = cb.readByte(); + IpPrefix ipPrefix; + if (length == 0) { + byte[] prefix = new byte[] {0}; + ipPrefix = Validation.bytesToPrefix(prefix, length); + nlri.add(ipPrefix); + } else { + int len = length / BYTE_IN_BITS; + int reminder = length % BYTE_IN_BITS; + if (reminder > 0) { + len = len + 1; + } + if (cb.readableBytes() < len) { + Validation.validateLen(BgpErrorType.UPDATE_MESSAGE_ERROR, + BgpErrorType.MALFORMED_ATTRIBUTE_LIST, + cb.readableBytes()); + } + byte[] prefix = new byte[len]; + cb.readBytes(prefix, 0, len); + ipPrefix = Validation.bytesToPrefix(prefix, length); + nlri.add(ipPrefix); + } + } + return nlri; + } + + /** + * Parsing withdrawn routes from channel buffer. + * + * @param cb channelBuffer + * @return list of IP prefix + * @throws BgpParseException while parsing withdrawn routes + */ + public static LinkedList<IpPrefix> parseWithdrawnRoutes(ChannelBuffer cb) + throws BgpParseException { + LinkedList<IpPrefix> withDrwRoutes = new LinkedList<>(); + while (cb.readableBytes() > 0) { + int length = cb.readByte(); + IpPrefix ipPrefix; + if (length == 0) { + byte[] prefix = new byte[] {0}; + ipPrefix = Validation.bytesToPrefix(prefix, length); + withDrwRoutes.add(ipPrefix); + } else { + int len = length / BYTE_IN_BITS; + int reminder = length % BYTE_IN_BITS; + if (reminder > 0) { + len = len + 1; + } + if (cb.readableBytes() < len) { + Validation + .validateLen(BgpErrorType.UPDATE_MESSAGE_ERROR, + BgpErrorType.MALFORMED_ATTRIBUTE_LIST, + cb.readableBytes()); + } + byte[] prefix = new byte[len]; + cb.readBytes(prefix, 0, len); + ipPrefix = Validation.bytesToPrefix(prefix, length); + withDrwRoutes.add(ipPrefix); + } + } + return withDrwRoutes; + } + + @Override + public BgpVersion getVersion() { + return BgpVersion.BGP_4; + } + + @Override + public BgpType getType() { + return BgpType.UPDATE; + } + + @Override + public void writeTo(ChannelBuffer channelBuffer) throws BgpParseException { + //Not to be implemented as of now + } + + @Override + public BgpPathAttributes bgpPathAttributes() { + return this.bgpPathAttributes; + } + + @Override + public List<IpPrefix> withdrawnRoutes() { + return withdrawnRoutes; + } + + @Override + public List<IpPrefix> nlri() { + return nlri; + } + + @Override + public BgpHeader getHeader() { + return this.bgpHeader; + } + + @Override + public String toString() { + return MoreObjects.toStringHelper(getClass()) + .omitNullValues() + .add("bgpHeader", bgpHeader) + .add("withDrawnRoutes", withdrawnRoutes) + .add("nlri", nlri) + .add("bgpPathAttributes", bgpPathAttributes) + .toString(); + } +} |