Implemented a mechanism to easily add and access Neighbor Discovery protocol
packet options.
Fixes ONOS-1011
Change-Id: I94daa3f3c1297fb9a7b44901927738a29aff030a
diff --git a/utils/misc/src/main/java/org/onlab/packet/ndp/NeighborDiscoveryOptions.java b/utils/misc/src/main/java/org/onlab/packet/ndp/NeighborDiscoveryOptions.java
new file mode 100644
index 0000000..b8561b1
--- /dev/null
+++ b/utils/misc/src/main/java/org/onlab/packet/ndp/NeighborDiscoveryOptions.java
@@ -0,0 +1,232 @@
+/*
+ * 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.onlab.packet.ndp;
+
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import org.onlab.packet.BasePacket;
+import org.onlab.packet.IPacket;
+
+/**
+ * Neighbor Discovery Protocol packet options.
+ */
+public class NeighborDiscoveryOptions extends BasePacket {
+ public static final byte TYPE_SOURCE_LL_ADDRESS = 1;
+ public static final byte TYPE_TARGET_LL_ADDRESS = 2;
+ public static final byte TYPE_PREFIX_INFORMATION = 3;
+ public static final byte TYPE_REDIRECTED_HEADER = 4;
+ public static final byte TYPE_MTU = 5;
+
+ private final List<Option> options = new ArrayList<>();
+
+ /**
+ * Packet option.
+ */
+ public final class Option {
+ private final byte type;
+ private final byte[] data;
+
+ /**
+ * Constructor.
+ *
+ * @param type the option type
+ * @param data the option data
+ */
+ private Option(byte type, byte[] data) {
+ this.type = type;
+ this.data = Arrays.copyOfRange(data, 0, data.length);
+ }
+
+ /**
+ * Gets the option type.
+ *
+ * @return the option type
+ */
+ public byte type() {
+ return this.type;
+ }
+
+ /**
+ * Gets the option data.
+ *
+ * @return the option data
+ */
+ public byte[] data() {
+ return this.data;
+ }
+
+ /**
+ * Gets the option data length (in number of octets).
+ *
+ * @return the option data length (in number of octets)
+ */
+ public int dataLength() {
+ return data.length;
+ }
+
+ /**
+ * Gets the option length (in number of octets), including the type and
+ * length fields (one octet each).
+ *
+ * @return the option length (in number of octets), including the type
+ * and length fields
+ */
+ private int optionLength() {
+ return 2 + dataLength();
+ }
+
+ /**
+ * Gets the option length field value (in units of 8 octets).
+ *
+ * @return the option length field value (in units of 8 octets)
+ */
+ private byte optionLengthField() {
+ return (byte) ((optionLength() + 7) / 8);
+ }
+
+ /**
+ * Gets the option length on the wire (in number of octets).
+ *
+ * @return the option length on the wire (in number of octets)
+ */
+ private int optionWireLength() {
+ return 8 * optionLengthField();
+ }
+ }
+
+ /**
+ * Adds a Neighbor Discovery Protocol packet option.
+ *
+ * @param type the option type
+ * @param data the option data
+ * @return this
+ */
+ public NeighborDiscoveryOptions addOption(byte type, byte[] data) {
+ options.add(new Option(type, data));
+ return this;
+ }
+
+ /**
+ * Gets the Neighbor Discovery Protocol packet options.
+ *
+ * @return the Neighbor Discovery Protocol packet options
+ */
+ public List<NeighborDiscoveryOptions.Option> options() {
+ return this.options;
+ }
+
+ /**
+ * Checks whether any options are included.
+ *
+ * @return true if options are included, otherwise false
+ */
+ public boolean hasOptions() {
+ return !this.options.isEmpty();
+ }
+
+ @Override
+ public byte[] serialize() {
+ // Compute first the total length on the wire for all options
+
+ int wireLength = 0;
+
+ for (Option option : this.options) {
+ wireLength += option.optionWireLength();
+ }
+
+ final byte[] data = new byte[wireLength];
+ final ByteBuffer bb = ByteBuffer.wrap(data);
+
+ //
+ // Serialize all options
+ //
+ for (Option option : this.options) {
+ bb.put(option.type());
+ bb.put(option.optionLengthField());
+ bb.put(option.data());
+ // Add the padding
+ int paddingLength =
+ option.optionWireLength() - option.optionLength();
+ for (int i = 0; i < paddingLength; i++) {
+ bb.put((byte) 0);
+ }
+ }
+
+ return data;
+ }
+
+ @Override
+ public IPacket deserialize(byte[] data, int offset, int length) {
+ final ByteBuffer bb = ByteBuffer.wrap(data, offset, length);
+
+ options.clear();
+
+ //
+ // Deserialize all options
+ //
+ while (bb.hasRemaining()) {
+ byte type = bb.get();
+ if (!bb.hasRemaining()) {
+ break;
+ }
+ byte lengthField = bb.get();
+ int dataLength = lengthField * 8; // The data length field is in
+ // unit of 8 octets
+
+ // Exclude the type and length fields
+ if (dataLength < 2) {
+ break;
+ }
+ dataLength -= 2;
+
+ if (bb.remaining() < dataLength) {
+ break;
+ }
+ byte[] optionData = new byte[dataLength];
+ bb.get(optionData, 0, optionData.length);
+ addOption(type, optionData);
+ }
+
+ return this;
+ }
+
+ @Override
+ public int hashCode() {
+ final int prime = 31;
+ int result = 1;
+
+ for (Option option : this.options) {
+ result = prime * result + option.type();
+ result = prime * result + Arrays.hashCode(option.data());
+ }
+ return result;
+ }
+
+ @Override
+ public boolean equals(final Object obj) {
+ if (this == obj) {
+ return true;
+ }
+ if (obj instanceof NeighborDiscoveryOptions) {
+ NeighborDiscoveryOptions other = (NeighborDiscoveryOptions) obj;
+ return this.options.equals(other.options);
+ }
+ return false;
+ }
+}