/* * 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 org.jboss.netty.buffer.ChannelBuffer; import org.onosproject.bgpio.exceptions.BGPParseException; import org.onosproject.bgpio.protocol.BGPMessageReader; import org.onosproject.bgpio.protocol.BGPMessageWriter; import org.onosproject.bgpio.protocol.BGPNotificationMsg; import org.onosproject.bgpio.protocol.BGPType; import org.onosproject.bgpio.protocol.BGPVersion; import org.onosproject.bgpio.types.BGPErrorType; import org.onosproject.bgpio.types.BGPHeader; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.google.common.base.MoreObjects; /** * A NOTIFICATION message is sent when an error condition is detected. The BGP connection is closed immediately after it * is sent. */ class BGPNotificationMsgVer4 implements BGPNotificationMsg { /* 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Error code | Error subcode | Data (variable) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ REFERENCE : RFC 4271 */ private static final Logger log = LoggerFactory.getLogger(BGPNotificationMsgVer4.class); static final byte PACKET_VERSION = 4; //BGPHeader(19) + Error code(1) + Error subcode(1) static final int TOTAL_MESSAGE_MIN_LENGTH = 21; static final int PACKET_MINIMUM_LENGTH = 2; static final BGPType MSG_TYPE = BGPType.NOTIFICATION; static final byte DEFAULT_ERRORSUBCODE = 0; static final byte[] MARKER = {(byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff }; static final byte MESSAGE_TYPE = 3; static final BGPHeader DEFAULT_MESSAGE_HEADER = new BGPHeader(MARKER, BGPHeader.DEFAULT_HEADER_LENGTH, MESSAGE_TYPE); private byte errorCode; private byte errorSubCode; private byte[] data; private BGPHeader bgpHeader; public static final BGPNotificationMsgVer4.Reader READER = new Reader(); /** * Initialize fields. */ public BGPNotificationMsgVer4() { this.bgpHeader = null; this.data = null; this.errorCode = 0; this.errorSubCode = 0; } /** * Constructor to initialize parameters. * * @param bgpHeader BGP Header in notification message * @param errorCode error code * @param errorSubCode error subcode * @param data field */ public BGPNotificationMsgVer4(BGPHeader bgpHeader, byte errorCode, byte errorSubCode, byte[] data) { this.bgpHeader = bgpHeader; this.data = data; this.errorCode = errorCode; this.errorSubCode = errorSubCode; } /** * Reader reads BGP Notification Message from the channel buffer. */ static class Reader implements BGPMessageReader { @Override public BGPNotificationMsg readFrom(ChannelBuffer cb, BGPHeader bgpHeader) throws BGPParseException { byte errorCode; byte errorSubCode; if (cb.readableBytes() < PACKET_MINIMUM_LENGTH) { throw new BGPParseException("Not enough readable bytes"); } errorCode = cb.readByte(); errorSubCode = cb.readByte(); //Message Length = 21 + Data Length int dataLength = bgpHeader.getLength() - TOTAL_MESSAGE_MIN_LENGTH; byte[] data = new byte[dataLength]; cb.readBytes(data, 0, dataLength); return new BGPNotificationMsgVer4(bgpHeader, errorCode, errorSubCode, data); } } /** * Builder class for BGP notification message. */ static class Builder implements BGPNotificationMsg.Builder { private byte errorCode; private byte errorSubCode; private byte[] data; private BGPHeader bgpHeader; private boolean isErrorCodeSet = false; private boolean isErrorSubCodeSet = false; private boolean isBGPHeaderSet = false; @Override public BGPNotificationMsg build() throws BGPParseException { BGPHeader bgpHeader = this.isBGPHeaderSet ? this.bgpHeader : DEFAULT_MESSAGE_HEADER; if (!this.isErrorCodeSet) { throw new BGPParseException("Error code must be present"); } byte errorSubCode = this.isErrorSubCodeSet ? this.errorSubCode : DEFAULT_ERRORSUBCODE; return new BGPNotificationMsgVer4(bgpHeader, this.errorCode, errorSubCode, this.data); } @Override public Builder setErrorCode(byte errorCode) { this.errorCode = errorCode; this.isErrorCodeSet = true; return this; } @Override public Builder setErrorSubCode(byte errorSubCode) { this.errorSubCode = errorSubCode; this.isErrorSubCodeSet = true; return this; } @Override public Builder setData(byte[] data) { this.data = data; return this; } @Override public Builder setHeader(BGPHeader bgpMsgHeader) { this.bgpHeader = bgpMsgHeader; return this; } } @Override public BGPVersion getVersion() { return BGPVersion.BGP_4; } @Override public BGPType getType() { return BGPType.NOTIFICATION; } @Override public void writeTo(ChannelBuffer cb) throws BGPParseException { WRITER.write(cb, this); } static final Writer WRITER = new Writer(); /** * Writer writes BGP notification message to channel buffer. */ static class Writer implements BGPMessageWriter { @Override public void write(ChannelBuffer cb, BGPNotificationMsgVer4 message) throws BGPParseException { int msgStartIndex = cb.writerIndex(); int headerLenIndex = message.bgpHeader.write(cb); if (headerLenIndex <= 0) { throw new BGPParseException(BGPErrorType.MESSAGE_HEADER_ERROR, (byte) 0, null); } cb.writeByte(message.errorCode); cb.writeByte(message.errorSubCode); cb.writeBytes(message.data); //Update message length field in notification message int length = cb.writerIndex() - msgStartIndex; cb.setShort(headerLenIndex, (short) length); message.bgpHeader.setLength((short) length); } } @Override public byte getErrorCode() { return this.errorCode; } /** * Sets errorcode with specified errorcode. * * @param errorCode field */ public void setErrorCode(byte errorCode) { this.errorCode = errorCode; } @Override public byte getErrorSubCode() { return this.errorSubCode; } /** * Sets error subcode with specified errorSubCode. * * @param errorSubCode field */ public void setErrorSubCode(byte errorSubCode) { this.errorSubCode = errorSubCode; } @Override public byte[] getData() { return this.data; } /** * Sets error data with specified data. * * @param data field */ public void setData(byte[] data) { this.data = data; } @Override public BGPHeader getHeader() { return this.bgpHeader; } @Override public String toString() { return MoreObjects.toStringHelper(getClass()) .omitNullValues() .add("bgpHeader", bgpHeader) .add("data", data) .add("errorCode", errorCode) .add("errorSubCode", errorSubCode) .toString(); } }