[Emu][ONOS-2597] BGP Keepalive message encoding and decoding
Change-Id: I4dd39f1725aa426827d5c4f011f5a0e02557a5c3
diff --git a/bgp/bgpio/src/main/java/org/onosproject/bgpio/protocol/ver4/BGPKeepaliveMsgVer4.java b/bgp/bgpio/src/main/java/org/onosproject/bgpio/protocol/ver4/BGPKeepaliveMsgVer4.java
new file mode 100644
index 0000000..a6668b3
--- /dev/null
+++ b/bgp/bgpio/src/main/java/org/onosproject/bgpio/protocol/ver4/BGPKeepaliveMsgVer4.java
@@ -0,0 +1,172 @@
+/*
+ * 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.BGPKeepaliveMsg;
+import org.onosproject.bgpio.protocol.BGPMessageReader;
+import org.onosproject.bgpio.protocol.BGPMessageWriter;
+import org.onosproject.bgpio.types.BGPHeader;
+import org.onosproject.bgpio.protocol.BGPType;
+import org.onosproject.bgpio.protocol.BGPVersion;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.base.MoreObjects;
+
+/**
+ * Provides BGP keep alive message.
+ */
+class BGPKeepaliveMsgVer4 implements BGPKeepaliveMsg {
+
+ /*
+ <Keepalive Message>::= <Common Header>
+ A KEEPALIVE message consists of only the message header and has a
+ length of 19 octets.
+
+ 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 |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+ REFERENCE : RFC 4271
+ */
+
+ protected static final Logger log = LoggerFactory
+ .getLogger(BGPKeepaliveMsgVer4.class);
+
+ private BGPHeader bgpMsgHeader;
+ public static final byte PACKET_VERSION = 4;
+ public static final int PACKET_MINIMUM_LENGTH = 19;
+ public static final int MARKER_LENGTH = 16;
+ public static final BGPType MSG_TYPE = BGPType.KEEP_ALIVE;
+ public static byte[] marker = new byte[] {(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};
+
+ public static final BGPKeepaliveMsgVer4.Reader READER = new Reader();
+
+ /**
+ * Reader class for reading BGP keepalive message from channel buffer.
+ */
+ static class Reader implements BGPMessageReader<BGPKeepaliveMsg> {
+
+ @Override
+ public BGPKeepaliveMsg readFrom(ChannelBuffer cb, BGPHeader bgpHeader)
+ throws BGPParseException {
+
+ /* bgpHeader is not required in case of keepalive message and
+ Header is already read and no other fields except header in keepalive message.*/
+ return new BGPKeepaliveMsgVer4();
+ }
+ }
+
+ /**
+ * Default constructor.
+ */
+ BGPKeepaliveMsgVer4() {
+ }
+
+ /**
+ * Builder class for BGP keepalive message.
+ */
+ static class Builder implements BGPKeepaliveMsg.Builder {
+ BGPHeader bgpMsgHeader;
+
+ @Override
+ public BGPVersion getVersion() {
+ return BGPVersion.BGP_4;
+ }
+
+ @Override
+ public BGPType getType() {
+ return BGPType.KEEP_ALIVE;
+ }
+
+ @Override
+ public BGPHeader getHeader() {
+ return this.bgpMsgHeader;
+ }
+
+ @Override
+ public Builder setHeader(BGPHeader bgpMsgHeader) {
+ this.bgpMsgHeader = bgpMsgHeader;
+ return this;
+ }
+
+ @Override
+ public BGPKeepaliveMsg build() {
+ return new BGPKeepaliveMsgVer4();
+ }
+ }
+
+ @Override
+ public void writeTo(ChannelBuffer cb) {
+ WRITER.write(cb, this);
+ }
+
+ static final Writer WRITER = new Writer();
+
+ /**
+ * Writer class for writing the BGP keepalive message to channel buffer.
+ */
+ static class Writer implements BGPMessageWriter<BGPKeepaliveMsgVer4> {
+
+ @Override
+ public void write(ChannelBuffer cb, BGPKeepaliveMsgVer4 message) {
+
+ // write marker
+ cb.writeBytes(marker, 0, MARKER_LENGTH);
+
+ // write length of header
+ cb.writeShort(PACKET_MINIMUM_LENGTH);
+
+ // write the type of message
+ cb.writeByte(MSG_TYPE.getType());
+ }
+ }
+
+ @Override
+ public BGPVersion getVersion() {
+ return BGPVersion.BGP_4;
+ }
+
+ @Override
+ public BGPType getType() {
+ return MSG_TYPE;
+ }
+
+ @Override
+ public BGPHeader getHeader() {
+ return this.bgpMsgHeader;
+ }
+
+ @Override
+ public String toString() {
+ return MoreObjects.toStringHelper(getClass()).toString();
+ }
+}