[Emu][onos-2603] - Implement LinkState Link attributes-Link Name

Change-Id: I3bc3c59f8afef2f46148c061f454e8830628513a

+/*
+ * 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.onosproject.bgpio.types.attr;
+
+import java.util.Arrays;
+import java.util.Objects;
+
+import org.jboss.netty.buffer.ChannelBuffer;
+import org.onosproject.bgpio.exceptions.BGPParseException;
+import org.onosproject.bgpio.types.BGPErrorType;
+import org.onosproject.bgpio.types.BGPValueType;
+import org.onosproject.bgpio.util.Validation;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.base.MoreObjects;
+
+/**
+ * Implements BGP link name attribute.
+ */
+public class BgpLinkAttrName implements BGPValueType {
+
+    protected static final Logger log = LoggerFactory
+            .getLogger(BgpLinkAttrName.class);
+
+    public static final int ATTRLINK_NAME = 1098;
+
+    /* Link Name */
+    private byte[] linkName;
+
+    /**
+     * Constructor to initialize the values.
+     *
+     * @param linkName link name
+     */
+    BgpLinkAttrName(byte[] linkName) {
+        this.linkName = Arrays.copyOf(linkName, linkName.length);
+    }
+
+    /**
+     * Reads the BGP link attributes Name.
+     *
+     * @param cb Channel buffer
+     * @return object of type BgpLinkAttrName
+     * @throws BGPParseException while parsing BgpLinkAttrName
+     */
+    public static BgpLinkAttrName read(ChannelBuffer cb)
+            throws BGPParseException {
+        byte[] linkName;
+        short lsAttrLength = cb.readShort();
+
+        if (cb.readableBytes() < lsAttrLength) {
+            Validation.validateLen(BGPErrorType.UPDATE_MESSAGE_ERROR,
+                                   BGPErrorType.ATTRIBUTE_LENGTH_ERROR,
+                                   lsAttrLength);
+        }
+
+        linkName = new byte[lsAttrLength];
+        cb.readBytes(linkName);
+        return new BgpLinkAttrName(linkName);
+    }
+
+    /**
+     * Returns the link name.
+     *
+     * @return link name
+     */
+    byte[] getAttrLinkName() {
+        return linkName;
+    }
+
+    @Override
+    public short getType() {
+        return ATTRLINK_NAME;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(linkName);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+
+        if (obj instanceof BgpLinkAttrName) {
+            BgpLinkAttrName other = (BgpLinkAttrName) obj;
+            return Objects.equals(linkName, other.linkName);
+        }
+        return false;
+    }
+
+    @Override
+    public int write(ChannelBuffer cb) {
+        // TODO This will be implemented in the next version
+        return 0;
+    }
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper(getClass()).omitNullValues()
+                .add("linkName", linkName).toString();
+    }
+}