[CORD-2182] Implement packet serializer/deserializer for Routing Information Protocol (RIP)

Change-Id: If80af0b04a86972b91e6a9d9731864ff35c833e4
diff --git a/utils/misc/src/main/java/org/onlab/packet/RIPng.java b/utils/misc/src/main/java/org/onlab/packet/RIPng.java
new file mode 100644
index 0000000..144302f
--- /dev/null
+++ b/utils/misc/src/main/java/org/onlab/packet/RIPng.java
@@ -0,0 +1,238 @@
+/*
+ * Copyright 2017-present Open Networking Foundation
+ *
+ * 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.
+ */
+
+/**
+ * Implemented according to RFC 2080
+ */
+
+package org.onlab.packet;
+
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
+
+import static org.onlab.packet.PacketUtils.checkInput;
+import static com.google.common.base.MoreObjects.toStringHelper;
+import org.slf4j.Logger;
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Representation of an RIPng Packet.
+ */
+public class RIPng extends BasePacket {
+    /**
+     * Routing Information Protocol Next Generation packet.
+     * ------------------------------------------ |cmdType (1) | version(1) |
+     * ------------------------------------------ |reserved (2) |
+     * ------------------------------------------ | route entries (n*20) |
+     * ------------------------------------------
+     *
+     */
+    // the case of no route entry
+    public static final int MIN_HEADER_LENGTH = 4;
+
+
+    private final Logger log = getLogger(getClass());
+
+    public enum CmdType {
+        RIPngREQUEST(1),
+        RIPngRESPONSE(2);
+
+        protected int value;
+
+        CmdType(final int value) {
+            this.value = value;
+        }
+
+        public int getValue() {
+            return this.value;
+        }
+
+        public static CmdType getType(final int value) {
+            switch (value) {
+                case 1:
+                    return RIPngREQUEST;
+                case 2:
+                    return RIPngRESPONSE;
+                default:
+                    return null;
+            }
+        }
+    }
+
+    protected byte cmdType;
+    protected byte version;
+    protected short reserved;
+    protected List<RIPngEntry> rtEntries = new ArrayList<RIPngEntry>();
+
+    /**
+     * @return the cmdType
+     */
+    public byte getCmdType() {
+        return this.cmdType;
+    }
+
+    /**
+     * @param cmdType
+     *            the cmdType to set
+     * @return this
+     */
+    public RIPng setCmdType(final byte cmdType) {
+        this.cmdType = cmdType;
+        return this;
+    }
+
+    /**
+     * @return the version
+     */
+    public byte getVersion() {
+        return this.version;
+    }
+
+    /**
+     * @param version
+     *            the version to set
+     * @return this
+     */
+    public RIPng setVersion(final byte version) {
+        this.version = version;
+        return this;
+    }
+
+    /**
+     * @return the reserved short
+     */
+    public short getReserved() {
+        return this.reserved;
+    }
+
+    /**
+     * @param reserved
+     *            the reserved short to set
+     * @return this
+     */
+    public RIPng setReserved(final short reserved) {
+        this.reserved = reserved;
+        return this;
+    }
+
+    /**
+     * @return the route entries
+     */
+    public List<RIPngEntry> getRtEntries() {
+        return this.rtEntries;
+    }
+
+    /**
+     * @param entries
+     *            the route entries to set
+     * @return this
+     */
+    public RIPng setRtEntries(final List<RIPngEntry> entries) {
+        this.rtEntries = entries;
+        return this;
+    }
+
+    @Override
+    public byte[] serialize() {
+        // not guaranteed to retain length/exact format
+        this.resetChecksum();
+
+        final byte[] data = new byte[MIN_HEADER_LENGTH + RIPngEntry.ENTRY_LEN * rtEntries.size()];
+        final ByteBuffer bb = ByteBuffer.wrap(data);
+        bb.put(this.cmdType);
+        bb.put(this.version);
+        bb.putShort(this.reserved);
+        for (final RIPngEntry entry : this.rtEntries) {
+            bb.put(entry.serialize());
+        }
+        // assume the rest is padded out with zeroes
+        return data;
+    }
+
+    /**
+     * Deserializer function for RIPng packets.
+     *
+     * @return deserializer function
+     */
+    public static Deserializer<RIPng> deserializer() {
+        return (data, offset, length) -> {
+            RIPng ripng = new RIPng();
+
+            checkInput(data, offset, length, MIN_HEADER_LENGTH);
+
+            ByteBuffer bb = ByteBuffer.wrap(data, offset, length);
+
+            ripng.cmdType = bb.get();
+            ripng.version = bb.get();
+            ripng.reserved = bb.getShort();
+
+            // read route entries
+            while (bb.hasRemaining() && (bb.remaining() >= RIPngEntry.ENTRY_LEN)) {
+                RIPngEntry rtEntry;
+                byte[] rtData = new byte[RIPngEntry.ENTRY_LEN];
+                bb.get(rtData);
+
+                rtEntry = RIPngEntry.deserializer().deserialize(rtData, 0, rtData.length);
+                ripng.rtEntries.add(rtEntry);
+            }
+
+            return ripng;
+        };
+    }
+    /*
+     * (non-Javadoc)
+     *
+     * @see java.lang.Object#hashCode()
+     */
+    @Override
+    public int hashCode() {
+        return Objects.hash(super.hashCode(), cmdType, reserved, version, rtEntries);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see java.lang.Object#equals(java.lang.Object)
+     */
+    @Override
+    public boolean equals(final Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (!(obj instanceof RIPng)) {
+            return false;
+        }
+        final RIPng that = (RIPng) obj;
+
+        return super.equals(that) &&
+                Objects.equals(version, that.version) &&
+                Objects.equals(reserved, that.reserved) &&
+                Objects.equals(cmdType, that.cmdType) &&
+                Objects.equals(rtEntries, that.rtEntries);
+    }
+
+    @Override
+    public String toString() {
+        return toStringHelper(getClass())
+                .add("cmdType", Byte.toString(cmdType))
+                .add("version", Byte.toString(version))
+                .add("reserved", Short.toString(reserved))
+                .toString();
+        // TODO: need to handle route entries
+    }
+}