Add abstract IP header class to unify IPv4 and IPv6 header classes

Change-Id: Ia932dad67f64595b52b6fbc7dc43a13f64d53796

+/*
+ * Copyright 2016-present 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;
+
+/**
+ * Implements IP packet format.
+ */
+public abstract class IP extends BasePacket {
+
+    /**
+     * Gets IP version number.
+     *
+     * @return IP version number
+     */
+    public abstract byte getVersion();
+
+    /**
+     * Sets IP version number.
+     *
+     * @param version the version to set
+     * @return IP class
+     */
+    public abstract IP setVersion(final byte version);
+
+    /**
+     * Deserializer function for IP packets.
+     *
+     * @return deserializer function
+     */
+    public static Deserializer<? extends IP> deserializer() {
+        return (data, offset, length) -> {
+            final ByteBuffer bb = ByteBuffer.wrap(data, offset, length);
+            byte version = (byte) (bb.get() >> 4 & 0xf);
+
+            switch (version) {
+                case 4:
+                    return IPv4.deserializer().deserialize(data, offset, length);
+                case 6:
+                    return IPv6.deserializer().deserialize(data, offset, length);
+                default:
+                    throw new DeserializationException("Invalid IP version");
+            }
+        };
+    }
+}

@@ -14,9 +14,6 @@
  * limitations under the License.
  */
 
-/**
- *
- */
 package org.onlab.packet;
 
 import java.nio.ByteBuffer;
@@ -31,7 +28,7 @@ import static org.onlab.packet.PacketUtils.*;
 /**
  * Implements IPv4 packet format.
  */
-public class IPv4 extends BasePacket {
+public class IPv4 extends IP {
     public static final byte PROTOCOL_ICMP = 0x1;
     public static final byte PROTOCOL_IGMP = 0x2;
     public static final byte PROTOCOL_TCP = 0x6;
@@ -79,18 +76,12 @@ public class IPv4 extends BasePacket {
         this.isTruncated = false;
     }
 
-    /**
-     * @return the version
-     */
+    @Override
     public byte getVersion() {
         return this.version;
     }
 
-    /**
-     * @param version
-     *            the version to set
-     * @return this
-     */
+    @Override
     public IPv4 setVersion(final byte version) {
         this.version = version;
         return this;

@@ -14,8 +14,6 @@
  * limitations under the License.
  */
 
-
-
 package org.onlab.packet;
 
 import org.onlab.packet.ipv6.Authentication;
@@ -37,7 +35,7 @@ import static org.onlab.packet.PacketUtils.checkInput;
 /**
  * Implements IPv6 packet format. (RFC 2460)
  */
-public class IPv6 extends BasePacket implements IExtensionHeader {
+public class IPv6 extends IP implements IExtensionHeader {
     public static final byte FIXED_HEADER_LENGTH = 40; // bytes
 
     public static final byte PROTOCOL_TCP = 0x6;
@@ -83,21 +81,12 @@ public class IPv6 extends BasePacket implements IExtensionHeader {
         this.version = 6;
     }
 
-    /**
-     * Gets IP version.
-     *
-     * @return the IP version
-     */
+    @Override
     public byte getVersion() {
         return this.version;
     }
 
-    /**
-     * Sets IP version.
-     *
-     * @param version the IP version to set
-     * @return this
-     */
+    @Override
     public IPv6 setVersion(final byte version) {
         this.version = version;
         return this;

+/*
+ * Copyright 2016-present 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 org.junit.Before;
+import org.junit.Test;
+
+import java.nio.ByteBuffer;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.instanceOf;
+import static org.hamcrest.Matchers.is;
+
+/**
+ * Unit tests for IP class.
+ */
+public class IpTest {
+    private byte v4Version = 4;
+    private byte v4HeaderLength = 6;
+    private byte badVersion = 5;
+    private byte badHeaderLength = 6;
+    private static Data data;
+    private static UDP udp;
+    private byte[] v4HeaderBytes;
+    private byte[] v6HeaderBytes;
+    private byte[] badHeaderBytes;
+
+    @Before
+    public void setUp() throws Exception {
+
+        ByteBuffer v4bb = ByteBuffer.allocate(v4HeaderLength * 4);
+        v4bb.put((byte) ((v4Version & 0xf) << 4));
+        v4HeaderBytes = v4bb.array();
+
+        ByteBuffer badBb = ByteBuffer.allocate(badHeaderLength * 4);
+        badBb.put((byte) ((badVersion & 0xf) << 4));
+        badHeaderBytes = badBb.array();
+
+        data = new Data();
+        data.setData("testSerialize".getBytes());
+        udp = new UDP();
+        udp.setPayload(data);
+
+        byte[] bytePayload = udp.serialize();
+        byte[] byteHeader = {
+                (byte) 0x69, (byte) 0x31, (byte) 0x35, (byte) 0x79,
+                (byte) (bytePayload.length >> 8 & 0xff), (byte) (bytePayload.length & 0xff),
+                (byte) 0x11, (byte) 0x20,
+                (byte) 0x20, (byte) 0x01, (byte) 0x0f, (byte) 0x18, (byte) 0x01, (byte) 0x13, (byte) 0x02, (byte) 0x15,
+                (byte) 0xca, (byte) 0x2a, (byte) 0x14, (byte) 0xff, (byte) 0xfe, (byte) 0x35, (byte) 0x26, (byte) 0xce,
+                (byte) 0x20, (byte) 0x01, (byte) 0x0f, (byte) 0x18, (byte) 0x01, (byte) 0x13, (byte) 0x02, (byte) 0x15,
+                (byte) 0xe6, (byte) 0xce, (byte) 0x8f, (byte) 0xff, (byte) 0xfe, (byte) 0x54, (byte) 0x37, (byte) 0xc8,
+        };
+        v6HeaderBytes = new byte[byteHeader.length + bytePayload.length];
+        System.arraycopy(byteHeader, 0, v6HeaderBytes, 0, byteHeader.length);
+        System.arraycopy(bytePayload, 0, v6HeaderBytes, byteHeader.length, bytePayload.length);
+    }
+
+    @Test
+    public void testDeserialize() throws Exception {
+        Deserializer ipDeserializer = IP.deserializer();
+        IPacket v4Packet = ipDeserializer.deserialize(v4HeaderBytes, 0, v4HeaderLength * 4);
+        IPacket v6Packet = ipDeserializer.deserialize(v6HeaderBytes, 0, v6HeaderBytes.length);
+        assertThat(v4Packet, is(instanceOf(IPv4.class)));
+        assertThat(v6Packet, is(instanceOf(IPv6.class)));
+
+        IPv6 ipv6 = (IPv6) v6Packet;
+        assertThat(ipv6.getVersion(), is((byte) 6));
+        assertThat(ipv6.getTrafficClass(), is((byte) 0x93));
+        assertThat(ipv6.getFlowLabel(), is(0x13579));
+        assertThat(ipv6.getNextHeader(), is(IPv6.PROTOCOL_UDP));
+        assertThat(ipv6.getHopLimit(), is((byte) 32));
+    }
+
+    @Test(expected = DeserializationException.class)
+    public void testBadIpVersion() throws Exception {
+        Deserializer ipDeserializer = IP.deserializer();
+        ipDeserializer.deserialize(badHeaderBytes, 0, badHeaderLength * 4);
+    }
+}
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