ARP.java 13.8 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431
/*
 * Copyright 2014 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.onlab.packet;

import java.nio.ByteBuffer;
import java.util.Arrays;

import static com.google.common.base.MoreObjects.toStringHelper;
import static org.onlab.packet.PacketUtils.checkHeaderLength;
import static org.onlab.packet.PacketUtils.checkInput;

/**
 * Representation of an ARP Packet.
 */
public class ARP extends BasePacket {
    public static final short HW_TYPE_ETHERNET = 0x1;

    public static final short PROTO_TYPE_IP = 0x800;

    public static final short OP_REQUEST = 0x1;
    public static final short OP_REPLY = 0x2;
    public static final short OP_RARP_REQUEST = 0x3;
    public static final short OP_RARP_REPLY = 0x4;

    public static final short INITIAL_HEADER_LENGTH = 8;

    protected short hardwareType;
    protected short protocolType;
    protected byte hardwareAddressLength;
    protected byte protocolAddressLength;
    protected short opCode;
    protected byte[] senderHardwareAddress;
    protected byte[] senderProtocolAddress;
    protected byte[] targetHardwareAddress;
    protected byte[] targetProtocolAddress;

    /**
     * @return the hardwareType
     */
    public short getHardwareType() {
        return this.hardwareType;
    }

    /**
     * @param hwType
     *            the hardwareType to set
     * @return this
     */
    public ARP setHardwareType(final short hwType) {
        this.hardwareType = hwType;
        return this;
    }

    /**
     * @return the protocolType
     */
    public short getProtocolType() {
        return this.protocolType;
    }

    /**
     * @param protoType
     *            the protocolType to set
     * @return this
     */
    public ARP setProtocolType(final short protoType) {
        this.protocolType = protoType;
        return this;
    }

    /**
     * @return the hardwareAddressLength
     */
    public byte getHardwareAddressLength() {
        return this.hardwareAddressLength;
    }

    /**
     * @param hwAddressLength
     *            the hardwareAddressLength to set
     * @return this
     */
    public ARP setHardwareAddressLength(final byte hwAddressLength) {
        this.hardwareAddressLength = hwAddressLength;
        return this;
    }

    /**
     * @return the protocolAddressLength
     */
    public byte getProtocolAddressLength() {
        return this.protocolAddressLength;
    }

    /**
     * @param protoAddressLength
     *            the protocolAddressLength to set
     * @return this
     */
    public ARP setProtocolAddressLength(final byte protoAddressLength) {
        this.protocolAddressLength = protoAddressLength;
        return this;
    }

    /**
     * @return the opCode
     */
    public short getOpCode() {
        return this.opCode;
    }

    /**
     * @param op
     *            the opCode to set
     * @return this
     */
    public ARP setOpCode(final short op) {
        this.opCode = op;
        return this;
    }

    /**
     * @return the senderHardwareAddress
     */
    public byte[] getSenderHardwareAddress() {
        return this.senderHardwareAddress;
    }

    /**
     * @param senderHWAddress
     *            the senderHardwareAddress to set
     * @return this
     */
    public ARP setSenderHardwareAddress(final byte[] senderHWAddress) {
        this.senderHardwareAddress = senderHWAddress;
        return this;
    }

    /**
     * @return the senderProtocolAddress
     */
    public byte[] getSenderProtocolAddress() {
        return this.senderProtocolAddress;
    }

    /**
     * @param senderProtoAddress
     *            the senderProtocolAddress to set
     * @return this
     */
    public ARP setSenderProtocolAddress(final byte[] senderProtoAddress) {
        this.senderProtocolAddress = senderProtoAddress;
        return this;
    }

    public ARP setSenderProtocolAddress(final int address) {
        this.senderProtocolAddress = ByteBuffer.allocate(4).putInt(address)
                .array();
        return this;
    }

    /**
     * @return the targetHardwareAddress
     */
    public byte[] getTargetHardwareAddress() {
        return this.targetHardwareAddress;
    }

    /**
     * @param targetHWAddress
     *            the targetHardwareAddress to set
     * @return this
     */
    public ARP setTargetHardwareAddress(final byte[] targetHWAddress) {
        this.targetHardwareAddress = targetHWAddress;
        return this;
    }

    /**
     * @return the targetProtocolAddress
     */
    public byte[] getTargetProtocolAddress() {
        return this.targetProtocolAddress;
    }

    /**
     * @return True if gratuitous ARP (SPA = TPA), false otherwise
     */
    public boolean isGratuitous() {
        assert this.senderProtocolAddress.length == this.targetProtocolAddress.length;

        int indx = 0;
        while (indx < this.senderProtocolAddress.length) {
            if (this.senderProtocolAddress[indx] != this.targetProtocolAddress[indx]) {
                return false;
            }
            indx++;
        }

        return true;
    }

    /**
     * @param targetProtoAddress
     *            the targetProtocolAddress to set
     * @return this
     */
    public ARP setTargetProtocolAddress(final byte[] targetProtoAddress) {
        this.targetProtocolAddress = targetProtoAddress;
        return this;
    }

    public ARP setTargetProtocolAddress(final int address) {
        this.targetProtocolAddress = ByteBuffer.allocate(4).putInt(address)
                .array();
        return this;
    }

    @Override
    public byte[] serialize() {
        final int length = 8 + 2 * (0xff & this.hardwareAddressLength) + 2
                * (0xff & this.protocolAddressLength);
        final byte[] data = new byte[length];
        final ByteBuffer bb = ByteBuffer.wrap(data);
        bb.putShort(this.hardwareType);
        bb.putShort(this.protocolType);
        bb.put(this.hardwareAddressLength);
        bb.put(this.protocolAddressLength);
        bb.putShort(this.opCode);
        bb.put(this.senderHardwareAddress, 0, 0xff & this.hardwareAddressLength);
        bb.put(this.senderProtocolAddress, 0, 0xff & this.protocolAddressLength);
        bb.put(this.targetHardwareAddress, 0, 0xff & this.hardwareAddressLength);
        bb.put(this.targetProtocolAddress, 0, 0xff & this.protocolAddressLength);
        return data;
    }

    @Override
    public IPacket deserialize(final byte[] data, final int offset,
                               final int length) {
        final ByteBuffer bb = ByteBuffer.wrap(data, offset, length);
        this.hardwareType = bb.getShort();
        this.protocolType = bb.getShort();
        this.hardwareAddressLength = bb.get();
        this.protocolAddressLength = bb.get();
        this.opCode = bb.getShort();
        this.senderHardwareAddress = new byte[0xff & this.hardwareAddressLength];
        bb.get(this.senderHardwareAddress, 0, this.senderHardwareAddress.length);
        this.senderProtocolAddress = new byte[0xff & this.protocolAddressLength];
        bb.get(this.senderProtocolAddress, 0, this.senderProtocolAddress.length);
        this.targetHardwareAddress = new byte[0xff & this.hardwareAddressLength];
        bb.get(this.targetHardwareAddress, 0, this.targetHardwareAddress.length);
        this.targetProtocolAddress = new byte[0xff & this.protocolAddressLength];
        bb.get(this.targetProtocolAddress, 0, this.targetProtocolAddress.length);
        return this;
    }

    /*
     * (non-Javadoc)
     *
     * @see java.lang.Object#hashCode()
     */
    @Override
    public int hashCode() {
        final int prime = 13121;
        int result = super.hashCode();
        result = prime * result + this.hardwareAddressLength;
        result = prime * result + this.hardwareType;
        result = prime * result + this.opCode;
        result = prime * result + this.protocolAddressLength;
        result = prime * result + this.protocolType;
        result = prime * result + Arrays.hashCode(this.senderHardwareAddress);
        result = prime * result + Arrays.hashCode(this.senderProtocolAddress);
        result = prime * result + Arrays.hashCode(this.targetHardwareAddress);
        result = prime * result + Arrays.hashCode(this.targetProtocolAddress);
        return result;
    }

    /*
     * (non-Javadoc)
     *
     * @see java.lang.Object#equals(java.lang.Object)
     */
    @Override
    public boolean equals(final Object obj) {
        if (this == obj) {
            return true;
        }
        if (!super.equals(obj)) {
            return false;
        }
        if (!(obj instanceof ARP)) {
            return false;
        }
        final ARP other = (ARP) obj;
        if (this.hardwareAddressLength != other.hardwareAddressLength) {
            return false;
        }
        if (this.hardwareType != other.hardwareType) {
            return false;
        }
        if (this.opCode != other.opCode) {
            return false;
        }
        if (this.protocolAddressLength != other.protocolAddressLength) {
            return false;
        }
        if (this.protocolType != other.protocolType) {
            return false;
        }
        if (!Arrays.equals(this.senderHardwareAddress,
                other.senderHardwareAddress)) {
            return false;
        }
        if (!Arrays.equals(this.senderProtocolAddress,
                other.senderProtocolAddress)) {
            return false;
        }
        if (!Arrays.equals(this.targetHardwareAddress,
                other.targetHardwareAddress)) {
            return false;
        }
        if (!Arrays.equals(this.targetProtocolAddress,
                other.targetProtocolAddress)) {
            return false;
        }
        return true;
    }

    /**
     * Builds an ARP reply based on a request.
     *
     * @param srcIp the IP address to use as the reply source
     * @param srcMac the MAC address to use as the reply source
     * @param request the ARP request we got
     * @return an Ethernet frame containing the ARP reply
     */
    public static Ethernet buildArpReply(Ip4Address srcIp, MacAddress srcMac,
            Ethernet request) {

        Ethernet eth = new Ethernet();
        eth.setDestinationMACAddress(request.getSourceMAC());
        eth.setSourceMACAddress(srcMac);
        eth.setEtherType(Ethernet.TYPE_ARP);
        eth.setVlanID(request.getVlanID());

        ARP arp = new ARP();
        arp.setOpCode(ARP.OP_REPLY);
        arp.setProtocolType(ARP.PROTO_TYPE_IP);
        arp.setHardwareType(ARP.HW_TYPE_ETHERNET);

        arp.setProtocolAddressLength((byte) Ip4Address.BYTE_LENGTH);
        arp.setHardwareAddressLength((byte) Ethernet.DATALAYER_ADDRESS_LENGTH);
        arp.setSenderHardwareAddress(srcMac.toBytes());
        arp.setTargetHardwareAddress(request.getSourceMACAddress());

        arp.setTargetProtocolAddress(((ARP) request.getPayload())
                                             .getSenderProtocolAddress());
        arp.setSenderProtocolAddress(srcIp.toInt());

        eth.setPayload(arp);
        return eth;
    }

    /**
     * Deserializer function for ARP packets.
     *
     * @return deserializer function
     */
    public static Deserializer<ARP> deserializer() {
        return (data, offset, length) -> {
            checkInput(data, offset, length, INITIAL_HEADER_LENGTH);

            ARP arp = new ARP();
            final ByteBuffer bb = ByteBuffer.wrap(data, offset, length);
            arp.setHardwareType(bb.getShort());
            arp.setProtocolType(bb.getShort());

            byte hwAddressLength = bb.get();
            arp.setHardwareAddressLength(hwAddressLength);

            byte protocolAddressLength = bb.get();
            arp.setProtocolAddressLength(protocolAddressLength);
            arp.setOpCode(bb.getShort());

            // Check we have enough space for the addresses
            checkHeaderLength(length, INITIAL_HEADER_LENGTH +
                    2 * hwAddressLength +
                    2 * protocolAddressLength);

            arp.senderHardwareAddress = new byte[0xff & hwAddressLength];
            bb.get(arp.senderHardwareAddress, 0, arp.senderHardwareAddress.length);
            arp.senderProtocolAddress = new byte[0xff & protocolAddressLength];
            bb.get(arp.senderProtocolAddress, 0, arp.senderProtocolAddress.length);
            arp.targetHardwareAddress = new byte[0xff & hwAddressLength];
            bb.get(arp.targetHardwareAddress, 0, arp.targetHardwareAddress.length);
            arp.targetProtocolAddress = new byte[0xff & protocolAddressLength];
            bb.get(arp.targetProtocolAddress, 0, arp.targetProtocolAddress.length);

            return arp;
        };
    }

    @Override
    public String toString() {
        return toStringHelper(getClass())
                .add("hardwareType", Short.toString(hardwareType))
                .add("protocolType", Short.toString(protocolType))
                .add("hardwareAddressLength", Byte.toString(hardwareAddressLength))
                .add("protocolAddressLength", Byte.toString(protocolAddressLength))
                .add("opCode", Short.toString(opCode))
                .add("senderHardwareAddress", Arrays.toString(senderHardwareAddress))
                .add("senderProtocolAddress", Arrays.toString(senderProtocolAddress))
                .add("targetHardwareAddress", Arrays.toString(targetHardwareAddress))
                .add("targetProtocolAddress", Arrays.toString(targetProtocolAddress))
                .toString();
    }
}