Pavlin Radoslavov | a2626ef | 2015-02-18 18:33:25 -0800 | [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.onlab.packet.ndp; |
| 17 | |
| 18 | import java.nio.ByteBuffer; |
| 19 | import java.util.ArrayList; |
| 20 | import java.util.Arrays; |
| 21 | import java.util.List; |
| 22 | |
| 23 | import org.onlab.packet.BasePacket; |
| 24 | import org.onlab.packet.IPacket; |
| 25 | |
| 26 | /** |
| 27 | * Neighbor Discovery Protocol packet options. |
| 28 | */ |
| 29 | public class NeighborDiscoveryOptions extends BasePacket { |
| 30 | public static final byte TYPE_SOURCE_LL_ADDRESS = 1; |
| 31 | public static final byte TYPE_TARGET_LL_ADDRESS = 2; |
| 32 | public static final byte TYPE_PREFIX_INFORMATION = 3; |
| 33 | public static final byte TYPE_REDIRECTED_HEADER = 4; |
| 34 | public static final byte TYPE_MTU = 5; |
| 35 | |
| 36 | private final List<Option> options = new ArrayList<>(); |
| 37 | |
| 38 | /** |
| 39 | * Packet option. |
| 40 | */ |
| 41 | public final class Option { |
| 42 | private final byte type; |
| 43 | private final byte[] data; |
| 44 | |
| 45 | /** |
| 46 | * Constructor. |
| 47 | * |
| 48 | * @param type the option type |
| 49 | * @param data the option data |
| 50 | */ |
| 51 | private Option(byte type, byte[] data) { |
| 52 | this.type = type; |
| 53 | this.data = Arrays.copyOfRange(data, 0, data.length); |
| 54 | } |
| 55 | |
| 56 | /** |
| 57 | * Gets the option type. |
| 58 | * |
| 59 | * @return the option type |
| 60 | */ |
| 61 | public byte type() { |
| 62 | return this.type; |
| 63 | } |
| 64 | |
| 65 | /** |
| 66 | * Gets the option data. |
| 67 | * |
| 68 | * @return the option data |
| 69 | */ |
| 70 | public byte[] data() { |
| 71 | return this.data; |
| 72 | } |
| 73 | |
| 74 | /** |
| 75 | * Gets the option data length (in number of octets). |
| 76 | * |
| 77 | * @return the option data length (in number of octets) |
| 78 | */ |
| 79 | public int dataLength() { |
| 80 | return data.length; |
| 81 | } |
| 82 | |
| 83 | /** |
| 84 | * Gets the option length (in number of octets), including the type and |
| 85 | * length fields (one octet each). |
| 86 | * |
| 87 | * @return the option length (in number of octets), including the type |
| 88 | * and length fields |
| 89 | */ |
| 90 | private int optionLength() { |
| 91 | return 2 + dataLength(); |
| 92 | } |
| 93 | |
| 94 | /** |
| 95 | * Gets the option length field value (in units of 8 octets). |
| 96 | * |
| 97 | * @return the option length field value (in units of 8 octets) |
| 98 | */ |
| 99 | private byte optionLengthField() { |
| 100 | return (byte) ((optionLength() + 7) / 8); |
| 101 | } |
| 102 | |
| 103 | /** |
| 104 | * Gets the option length on the wire (in number of octets). |
| 105 | * |
| 106 | * @return the option length on the wire (in number of octets) |
| 107 | */ |
| 108 | private int optionWireLength() { |
| 109 | return 8 * optionLengthField(); |
| 110 | } |
| 111 | } |
| 112 | |
| 113 | /** |
| 114 | * Adds a Neighbor Discovery Protocol packet option. |
| 115 | * |
| 116 | * @param type the option type |
| 117 | * @param data the option data |
| 118 | * @return this |
| 119 | */ |
| 120 | public NeighborDiscoveryOptions addOption(byte type, byte[] data) { |
| 121 | options.add(new Option(type, data)); |
| 122 | return this; |
| 123 | } |
| 124 | |
| 125 | /** |
| 126 | * Gets the Neighbor Discovery Protocol packet options. |
| 127 | * |
| 128 | * @return the Neighbor Discovery Protocol packet options |
| 129 | */ |
| 130 | public List<NeighborDiscoveryOptions.Option> options() { |
| 131 | return this.options; |
| 132 | } |
| 133 | |
| 134 | /** |
| 135 | * Checks whether any options are included. |
| 136 | * |
| 137 | * @return true if options are included, otherwise false |
| 138 | */ |
| 139 | public boolean hasOptions() { |
| 140 | return !this.options.isEmpty(); |
| 141 | } |
| 142 | |
| 143 | @Override |
| 144 | public byte[] serialize() { |
| 145 | // Compute first the total length on the wire for all options |
| 146 | |
| 147 | int wireLength = 0; |
| 148 | |
| 149 | for (Option option : this.options) { |
| 150 | wireLength += option.optionWireLength(); |
| 151 | } |
| 152 | |
| 153 | final byte[] data = new byte[wireLength]; |
| 154 | final ByteBuffer bb = ByteBuffer.wrap(data); |
| 155 | |
| 156 | // |
| 157 | // Serialize all options |
| 158 | // |
| 159 | for (Option option : this.options) { |
| 160 | bb.put(option.type()); |
| 161 | bb.put(option.optionLengthField()); |
| 162 | bb.put(option.data()); |
| 163 | // Add the padding |
| 164 | int paddingLength = |
| 165 | option.optionWireLength() - option.optionLength(); |
| 166 | for (int i = 0; i < paddingLength; i++) { |
| 167 | bb.put((byte) 0); |
| 168 | } |
| 169 | } |
| 170 | |
| 171 | return data; |
| 172 | } |
| 173 | |
| 174 | @Override |
| 175 | public IPacket deserialize(byte[] data, int offset, int length) { |
| 176 | final ByteBuffer bb = ByteBuffer.wrap(data, offset, length); |
| 177 | |
| 178 | options.clear(); |
| 179 | |
| 180 | // |
| 181 | // Deserialize all options |
| 182 | // |
| 183 | while (bb.hasRemaining()) { |
| 184 | byte type = bb.get(); |
| 185 | if (!bb.hasRemaining()) { |
| 186 | break; |
| 187 | } |
| 188 | byte lengthField = bb.get(); |
| 189 | int dataLength = lengthField * 8; // The data length field is in |
| 190 | // unit of 8 octets |
| 191 | |
| 192 | // Exclude the type and length fields |
| 193 | if (dataLength < 2) { |
| 194 | break; |
| 195 | } |
| 196 | dataLength -= 2; |
| 197 | |
| 198 | if (bb.remaining() < dataLength) { |
| 199 | break; |
| 200 | } |
| 201 | byte[] optionData = new byte[dataLength]; |
| 202 | bb.get(optionData, 0, optionData.length); |
| 203 | addOption(type, optionData); |
| 204 | } |
| 205 | |
| 206 | return this; |
| 207 | } |
| 208 | |
| 209 | @Override |
| 210 | public int hashCode() { |
| 211 | final int prime = 31; |
| 212 | int result = 1; |
| 213 | |
| 214 | for (Option option : this.options) { |
| 215 | result = prime * result + option.type(); |
| 216 | result = prime * result + Arrays.hashCode(option.data()); |
| 217 | } |
| 218 | return result; |
| 219 | } |
| 220 | |
| 221 | @Override |
| 222 | public boolean equals(final Object obj) { |
| 223 | if (this == obj) { |
| 224 | return true; |
| 225 | } |
| 226 | if (obj instanceof NeighborDiscoveryOptions) { |
| 227 | NeighborDiscoveryOptions other = (NeighborDiscoveryOptions) obj; |
| 228 | return this.options.equals(other.options); |
| 229 | } |
| 230 | return false; |
| 231 | } |
| 232 | } |