Vidyashree Rama | e59ada1 | 2015-09-28 17:08:31 +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 org.jboss.netty.buffer.ChannelBuffer; |
| 19 | import org.onosproject.bgpio.exceptions.BGPParseException; |
| 20 | import org.onosproject.bgpio.protocol.BGPKeepaliveMsg; |
| 21 | import org.onosproject.bgpio.protocol.BGPMessageReader; |
| 22 | import org.onosproject.bgpio.protocol.BGPMessageWriter; |
| 23 | import org.onosproject.bgpio.types.BGPHeader; |
| 24 | import org.onosproject.bgpio.protocol.BGPType; |
| 25 | import org.onosproject.bgpio.protocol.BGPVersion; |
| 26 | import org.slf4j.Logger; |
| 27 | import org.slf4j.LoggerFactory; |
| 28 | |
| 29 | import com.google.common.base.MoreObjects; |
| 30 | |
| 31 | /** |
| 32 | * Provides BGP keep alive message. |
| 33 | */ |
| 34 | class BGPKeepaliveMsgVer4 implements BGPKeepaliveMsg { |
| 35 | |
| 36 | /* |
| 37 | <Keepalive Message>::= <Common Header> |
| 38 | A KEEPALIVE message consists of only the message header and has a |
| 39 | length of 19 octets. |
| 40 | |
| 41 | 0 1 2 3 |
| 42 | 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 |
| 43 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 44 | | | |
| 45 | + + |
| 46 | | | |
| 47 | + + |
| 48 | | Marker | |
| 49 | + + |
| 50 | | | |
| 51 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 52 | | Length | Type | |
| 53 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 54 | |
| 55 | REFERENCE : RFC 4271 |
| 56 | */ |
| 57 | |
| 58 | protected static final Logger log = LoggerFactory |
| 59 | .getLogger(BGPKeepaliveMsgVer4.class); |
| 60 | |
| 61 | private BGPHeader bgpMsgHeader; |
| 62 | public static final byte PACKET_VERSION = 4; |
| 63 | public static final int PACKET_MINIMUM_LENGTH = 19; |
| 64 | public static final int MARKER_LENGTH = 16; |
| 65 | public static final BGPType MSG_TYPE = BGPType.KEEP_ALIVE; |
| 66 | public static byte[] marker = new byte[] {(byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, |
| 67 | (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, |
| 68 | (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, |
| 69 | (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff}; |
| 70 | |
| 71 | public static final BGPKeepaliveMsgVer4.Reader READER = new Reader(); |
| 72 | |
| 73 | /** |
| 74 | * Reader class for reading BGP keepalive message from channel buffer. |
| 75 | */ |
| 76 | static class Reader implements BGPMessageReader<BGPKeepaliveMsg> { |
| 77 | |
| 78 | @Override |
| 79 | public BGPKeepaliveMsg readFrom(ChannelBuffer cb, BGPHeader bgpHeader) |
| 80 | throws BGPParseException { |
| 81 | |
| 82 | /* bgpHeader is not required in case of keepalive message and |
| 83 | Header is already read and no other fields except header in keepalive message.*/ |
| 84 | return new BGPKeepaliveMsgVer4(); |
| 85 | } |
| 86 | } |
| 87 | |
| 88 | /** |
| 89 | * Default constructor. |
| 90 | */ |
| 91 | BGPKeepaliveMsgVer4() { |
| 92 | } |
| 93 | |
| 94 | /** |
| 95 | * Builder class for BGP keepalive message. |
| 96 | */ |
| 97 | static class Builder implements BGPKeepaliveMsg.Builder { |
| 98 | BGPHeader bgpMsgHeader; |
| 99 | |
| 100 | @Override |
| 101 | public BGPVersion getVersion() { |
| 102 | return BGPVersion.BGP_4; |
| 103 | } |
| 104 | |
| 105 | @Override |
| 106 | public BGPType getType() { |
| 107 | return BGPType.KEEP_ALIVE; |
| 108 | } |
| 109 | |
| 110 | @Override |
| 111 | public BGPHeader getHeader() { |
| 112 | return this.bgpMsgHeader; |
| 113 | } |
| 114 | |
| 115 | @Override |
| 116 | public Builder setHeader(BGPHeader bgpMsgHeader) { |
| 117 | this.bgpMsgHeader = bgpMsgHeader; |
| 118 | return this; |
| 119 | } |
| 120 | |
| 121 | @Override |
| 122 | public BGPKeepaliveMsg build() { |
| 123 | return new BGPKeepaliveMsgVer4(); |
| 124 | } |
| 125 | } |
| 126 | |
| 127 | @Override |
| 128 | public void writeTo(ChannelBuffer cb) { |
| 129 | WRITER.write(cb, this); |
| 130 | } |
| 131 | |
| 132 | static final Writer WRITER = new Writer(); |
| 133 | |
| 134 | /** |
| 135 | * Writer class for writing the BGP keepalive message to channel buffer. |
| 136 | */ |
| 137 | static class Writer implements BGPMessageWriter<BGPKeepaliveMsgVer4> { |
| 138 | |
| 139 | @Override |
| 140 | public void write(ChannelBuffer cb, BGPKeepaliveMsgVer4 message) { |
| 141 | |
| 142 | // write marker |
| 143 | cb.writeBytes(marker, 0, MARKER_LENGTH); |
| 144 | |
| 145 | // write length of header |
| 146 | cb.writeShort(PACKET_MINIMUM_LENGTH); |
| 147 | |
| 148 | // write the type of message |
| 149 | cb.writeByte(MSG_TYPE.getType()); |
| 150 | } |
| 151 | } |
| 152 | |
| 153 | @Override |
| 154 | public BGPVersion getVersion() { |
| 155 | return BGPVersion.BGP_4; |
| 156 | } |
| 157 | |
| 158 | @Override |
| 159 | public BGPType getType() { |
| 160 | return MSG_TYPE; |
| 161 | } |
| 162 | |
| 163 | @Override |
| 164 | public BGPHeader getHeader() { |
| 165 | return this.bgpMsgHeader; |
| 166 | } |
| 167 | |
| 168 | @Override |
| 169 | public String toString() { |
| 170 | return MoreObjects.toStringHelper(getClass()).toString(); |
| 171 | } |
| 172 | } |