Thomas Vachuska | 24c849c | 2014-10-27 09:53:05 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * Licensed to the Apache Software Foundation (ASF) under one |
| 3 | * or more contributor license agreements. See the NOTICE file |
| 4 | * distributed with this work for additional information |
| 5 | * regarding copyright ownership. The ASF licenses this file |
| 6 | * to you under the Apache License, Version 2.0 (the |
| 7 | * "License"); you may not use this file except in compliance |
| 8 | * with the License. You may obtain a copy of the License at |
alshabib | c4901cd | 2014-09-05 16:50:40 -0700 | [diff] [blame] | 9 | * |
| 10 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 11 | * |
Thomas Vachuska | 24c849c | 2014-10-27 09:53:05 -0700 | [diff] [blame^] | 12 | * Unless required by applicable law or agreed to in writing, |
| 13 | * software distributed under the License is distributed on an |
| 14 | * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| 15 | * KIND, either express or implied. See the License for the |
| 16 | * specific language governing permissions and limitations |
alshabib | c4901cd | 2014-09-05 16:50:40 -0700 | [diff] [blame] | 17 | * under the License. |
Thomas Vachuska | 24c849c | 2014-10-27 09:53:05 -0700 | [diff] [blame^] | 18 | */ |
| 19 | |
| 20 | |
alshabib | c4901cd | 2014-09-05 16:50:40 -0700 | [diff] [blame] | 21 | |
| 22 | package org.onlab.packet; |
| 23 | |
| 24 | import java.nio.ByteBuffer; |
| 25 | |
| 26 | /** |
| 27 | * Implements ICMP packet format. |
| 28 | * |
alshabib | c4901cd | 2014-09-05 16:50:40 -0700 | [diff] [blame] | 29 | */ |
| 30 | public class ICMP extends BasePacket { |
| 31 | protected byte icmpType; |
| 32 | protected byte icmpCode; |
| 33 | protected short checksum; |
| 34 | |
| 35 | /** |
| 36 | * @return the icmpType |
| 37 | */ |
| 38 | public byte getIcmpType() { |
| 39 | return this.icmpType; |
| 40 | } |
| 41 | |
| 42 | /** |
| 43 | * @param icmpType |
| 44 | * to set |
| 45 | */ |
| 46 | public ICMP setIcmpType(final byte icmpType) { |
| 47 | this.icmpType = icmpType; |
| 48 | return this; |
| 49 | } |
| 50 | |
| 51 | /** |
| 52 | * @return the icmp code |
| 53 | */ |
| 54 | public byte getIcmpCode() { |
| 55 | return this.icmpCode; |
| 56 | } |
| 57 | |
| 58 | /** |
| 59 | * @param icmpCode |
| 60 | * code to set |
| 61 | */ |
| 62 | public ICMP setIcmpCode(final byte icmpCode) { |
| 63 | this.icmpCode = icmpCode; |
| 64 | return this; |
| 65 | } |
| 66 | |
| 67 | /** |
| 68 | * @return the checksum |
| 69 | */ |
| 70 | public short getChecksum() { |
| 71 | return this.checksum; |
| 72 | } |
| 73 | |
| 74 | /** |
| 75 | * @param checksum |
| 76 | * the checksum to set |
| 77 | */ |
| 78 | public ICMP setChecksum(final short checksum) { |
| 79 | this.checksum = checksum; |
| 80 | return this; |
| 81 | } |
| 82 | |
| 83 | /** |
| 84 | * Serializes the packet. Will compute and set the following fields if they |
| 85 | * are set to specific values at the time serialize is called: -checksum : 0 |
| 86 | * -length : 0 |
| 87 | */ |
| 88 | @Override |
| 89 | public byte[] serialize() { |
| 90 | int length = 4; |
| 91 | byte[] payloadData = null; |
| 92 | if (this.payload != null) { |
| 93 | this.payload.setParent(this); |
| 94 | payloadData = this.payload.serialize(); |
| 95 | length += payloadData.length; |
| 96 | } |
| 97 | |
| 98 | final byte[] data = new byte[length]; |
| 99 | final ByteBuffer bb = ByteBuffer.wrap(data); |
| 100 | |
| 101 | bb.put(this.icmpType); |
| 102 | bb.put(this.icmpCode); |
| 103 | bb.putShort(this.checksum); |
| 104 | if (payloadData != null) { |
| 105 | bb.put(payloadData); |
| 106 | } |
| 107 | |
| 108 | if (this.parent != null && this.parent instanceof IPv4) { |
| 109 | ((IPv4) this.parent).setProtocol(IPv4.PROTOCOL_ICMP); |
| 110 | } |
| 111 | |
| 112 | // compute checksum if needed |
| 113 | if (this.checksum == 0) { |
| 114 | bb.rewind(); |
| 115 | int accumulation = 0; |
| 116 | |
| 117 | for (int i = 0; i < length / 2; ++i) { |
| 118 | accumulation += 0xffff & bb.getShort(); |
| 119 | } |
| 120 | // pad to an even number of shorts |
| 121 | if (length % 2 > 0) { |
| 122 | accumulation += (bb.get() & 0xff) << 8; |
| 123 | } |
| 124 | |
| 125 | accumulation = (accumulation >> 16 & 0xffff) |
| 126 | + (accumulation & 0xffff); |
| 127 | this.checksum = (short) (~accumulation & 0xffff); |
| 128 | bb.putShort(2, this.checksum); |
| 129 | } |
| 130 | return data; |
| 131 | } |
| 132 | |
| 133 | /* |
| 134 | * (non-Javadoc) |
| 135 | * |
| 136 | * @see java.lang.Object#hashCode() |
| 137 | */ |
| 138 | @Override |
| 139 | public int hashCode() { |
| 140 | final int prime = 5807; |
| 141 | int result = super.hashCode(); |
| 142 | result = prime * result + this.icmpType; |
| 143 | result = prime * result + this.icmpCode; |
| 144 | result = prime * result + this.checksum; |
| 145 | return result; |
| 146 | } |
| 147 | |
| 148 | /* |
| 149 | * (non-Javadoc) |
| 150 | * |
| 151 | * @see java.lang.Object#equals(java.lang.Object) |
| 152 | */ |
| 153 | @Override |
| 154 | public boolean equals(final Object obj) { |
| 155 | if (this == obj) { |
| 156 | return true; |
| 157 | } |
| 158 | if (!super.equals(obj)) { |
| 159 | return false; |
| 160 | } |
| 161 | if (!(obj instanceof ICMP)) { |
| 162 | return false; |
| 163 | } |
| 164 | final ICMP other = (ICMP) obj; |
| 165 | if (this.icmpType != other.icmpType) { |
| 166 | return false; |
| 167 | } |
| 168 | if (this.icmpCode != other.icmpCode) { |
| 169 | return false; |
| 170 | } |
| 171 | if (this.checksum != other.checksum) { |
| 172 | return false; |
| 173 | } |
| 174 | return true; |
| 175 | } |
| 176 | |
| 177 | @Override |
| 178 | public IPacket deserialize(final byte[] data, final int offset, |
| 179 | final int length) { |
| 180 | final ByteBuffer bb = ByteBuffer.wrap(data, offset, length); |
| 181 | this.icmpType = bb.get(); |
| 182 | this.icmpCode = bb.get(); |
| 183 | this.checksum = bb.getShort(); |
| 184 | |
| 185 | this.payload = new Data(); |
| 186 | this.payload = this.payload.deserialize(data, bb.position(), bb.limit() |
| 187 | - bb.position()); |
| 188 | this.payload.setParent(this); |
| 189 | return this; |
| 190 | } |
| 191 | } |