[onos-2603] - Implement LinkState Link attributes-MPLS protocol mask

Change-Id: Ib0d8d098a5ecb77f98df60a6f6d6cfd8bd121c75

+/*
+ * 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.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 MPLS protocol mask attribute.
+ */
+public class BgpLinkAttrMplsProtocolMask implements BGPValueType {
+
+    protected static final Logger log = LoggerFactory
+            .getLogger(BgpLinkAttrMplsProtocolMask.class);
+
+    public static final int ATTRLINK_MPLSPROTOMASK = 1094;
+    public static final int MASK_BYTE_LEN = 1;
+
+    private final boolean bLdp;
+    private final boolean bRsvpTe;
+
+    public static final byte FIRST_BIT = (byte) 0x80;
+    public static final byte SECOND_BIT = 0x40;
+
+    /**
+     * Constructor to initialize the values.
+     *
+     * @param bLdp boolean value true if LDP flag is available
+     * @param bRsvpTe boolean value true if RSVP TE information is available
+     */
+    public BgpLinkAttrMplsProtocolMask(boolean bLdp, boolean bRsvpTe) {
+        this.bLdp = bLdp;
+        this.bRsvpTe = bRsvpTe;
+    }
+
+    /**
+     * Returns object of this class with specified values.
+     *
+     * @param bLdp boolean value true if LDP flag is available
+     * @param bRsvpTe boolean value true if RSVP TE information is available
+     * @return object of BgpLinkAttrMplsProtocolMask
+     */
+    public static BgpLinkAttrMplsProtocolMask of(final boolean bLdp,
+                                                 final boolean bRsvpTe) {
+        return new BgpLinkAttrMplsProtocolMask(bLdp, bRsvpTe);
+    }
+
+    /**
+     * Reads the BGP link attributes MPLS protocol mask.
+     *
+     * @param cb Channel buffer
+     * @return object of type BgpLinkAttrMPLSProtocolMask
+     * @throws BGPParseException while parsing BgpLinkAttrMplsProtocolMask
+     */
+    public static BgpLinkAttrMplsProtocolMask read(ChannelBuffer cb)
+            throws BGPParseException {
+        boolean bLdp = false;
+        boolean bRsvpTe = false;
+
+        short lsAttrLength = cb.readShort();
+
+        if ((lsAttrLength != MASK_BYTE_LEN)
+                || (cb.readableBytes() < lsAttrLength)) {
+            Validation.validateLen(BGPErrorType.UPDATE_MESSAGE_ERROR,
+                                   BGPErrorType.ATTRIBUTE_LENGTH_ERROR,
+                                   lsAttrLength);
+        }
+
+        byte flags = cb.readByte();
+
+        bLdp = ((flags & (byte) FIRST_BIT) == FIRST_BIT);
+        bRsvpTe = ((flags & (byte) SECOND_BIT) == SECOND_BIT);
+
+        return BgpLinkAttrMplsProtocolMask.of(bLdp, bRsvpTe);
+    }
+
+    /**
+     * Returns true if LDP bit is set.
+     *
+     * @return True if LDP information is set else false.
+     */
+    public boolean ldpBit() {
+        return bLdp;
+    }
+
+    /**
+     * Returns RSVP TE information.
+     *
+     * @return True if RSVP TE information is set else false.
+     */
+    public boolean rsvpBit() {
+        return bRsvpTe;
+    }
+
+    @Override
+    public short getType() {
+        return ATTRLINK_MPLSPROTOMASK;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(bLdp, bRsvpTe);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+
+        if (obj instanceof BgpLinkAttrMplsProtocolMask) {
+            BgpLinkAttrMplsProtocolMask other = (BgpLinkAttrMplsProtocolMask) obj;
+            return Objects.equals(bLdp, other.bLdp)
+                    && Objects.equals(bRsvpTe, other.bRsvpTe);
+        }
+        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())
+                .add("bLdp", bLdp).add("bRsvpTe", bRsvpTe).toString();
+    }
+}