[onos-2603] - Implements Max link bandwidth

Change-Id: I3861931b62b60518962c528b3f47a464cf08c314
diff --git a/bgp/bgpio/src/main/java/org/onosproject/bgpio/types/attr/BgpLinkAttrMaxLinkBandwidth.java b/bgp/bgpio/src/main/java/org/onosproject/bgpio/types/attr/BgpLinkAttrMaxLinkBandwidth.java
new file mode 100644
index 0000000..a1f0198
--- /dev/null
+++ b/bgp/bgpio/src/main/java/org/onosproject/bgpio/types/attr/BgpLinkAttrMaxLinkBandwidth.java
@@ -0,0 +1,150 @@
+/*
+ * 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 attribute Max Link bandwidth.
+ */
+public final class BgpLinkAttrMaxLinkBandwidth implements BGPValueType {
+
+    protected static final Logger log = LoggerFactory
+            .getLogger(BgpLinkAttrMaxLinkBandwidth.class);
+
+    public static final int MAX_BANDWIDTH_LEN = 4;
+    public static final int NO_OF_BITS = 8;
+
+    public short type;
+
+    /* ISIS administrative group */
+    private final float maxBandwidth;
+
+    /**
+     * Constructor to initialize the values.
+     *
+     * @param maxBandwidth Maximum link bandwidth.
+     * @param type TLV type
+     */
+    private BgpLinkAttrMaxLinkBandwidth(float maxBandwidth, short type) {
+        this.maxBandwidth = maxBandwidth;
+        this.type = type;
+    }
+
+    /**
+     * Returns object of this class with specified values.
+     *
+     * @param maxBandwidth Maximum link bandwidth.
+     * @param type TLV type
+     * @return object of BgpLinkAttrMaxLinkBandwidth
+     */
+    public static BgpLinkAttrMaxLinkBandwidth of(final float maxBandwidth,
+                                                 final short type) {
+        return new BgpLinkAttrMaxLinkBandwidth(maxBandwidth, type);
+    }
+
+    /**
+     * Reads the BGP link attributes of Maximum link bandwidth.
+     *
+     * @param cb Channel buffer
+     * @param type type of this tlv
+     * @return object of type BgpLinkAttrMaxLinkBandwidth
+     * @throws BGPParseException while parsing BgpLinkAttrMaxLinkBandwidth
+     */
+    public static BgpLinkAttrMaxLinkBandwidth read(ChannelBuffer cb, short type)
+            throws BGPParseException {
+        float maxBandwidth;
+        short lsAttrLength = cb.readShort();
+
+        if ((lsAttrLength != MAX_BANDWIDTH_LEN)
+                || (cb.readableBytes() < lsAttrLength)) {
+            Validation.validateLen(BGPErrorType.UPDATE_MESSAGE_ERROR,
+                                   BGPErrorType.ATTRIBUTE_LENGTH_ERROR,
+                                   lsAttrLength);
+        }
+
+        maxBandwidth = ieeeToFloatRead(cb.readInt()) * NO_OF_BITS;
+
+        return BgpLinkAttrMaxLinkBandwidth.of(maxBandwidth, type);
+    }
+
+    /**
+     * Returns Maximum link bandwidth.
+     *
+     * @return Maximum link bandwidth
+     */
+    float linkAttrMaxLinkBandwidth() {
+        return maxBandwidth;
+    }
+
+    /**
+     * Parse the IEEE floating point notation and returns it in normal float.
+     *
+     * @param iVal IEEE floating point number
+     * @return normal float
+     */
+    static float ieeeToFloatRead(int iVal) {
+        iVal = (((iVal & 0xFF) << 24) | ((iVal & 0xFF00) << 8)
+                | ((iVal & 0xFF0000) >> 8) | ((iVal >> 24) & 0xFF));
+
+        return Float.intBitsToFloat(iVal);
+    }
+
+    @Override
+    public short getType() {
+        return this.type;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(maxBandwidth);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+
+        if (obj instanceof BgpLinkAttrMaxLinkBandwidth) {
+            BgpLinkAttrMaxLinkBandwidth other = (BgpLinkAttrMaxLinkBandwidth) obj;
+            return Objects.equals(maxBandwidth, other.maxBandwidth);
+        }
+        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("maxBandwidth", maxBandwidth).toString();
+    }
+}
diff --git a/bgp/bgpio/src/test/java/org/onosproject/bgp/BgpLinkAttrMaxLinkBandwidthTest.java b/bgp/bgpio/src/test/java/org/onosproject/bgp/BgpLinkAttrMaxLinkBandwidthTest.java
new file mode 100644
index 0000000..d4c3b61
--- /dev/null
+++ b/bgp/bgpio/src/test/java/org/onosproject/bgp/BgpLinkAttrMaxLinkBandwidthTest.java
@@ -0,0 +1,44 @@
+/*
+ * 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.bgp;
+
+import org.junit.Test;
+import org.onosproject.bgpio.types.attr.BgpLinkAttrMaxLinkBandwidth;
+
+import com.google.common.testing.EqualsTester;
+
+/**
+ * Test for BGP link max bandwidth attribute.
+ */
+public class BgpLinkAttrMaxLinkBandwidthTest {
+    private final float val = 0x010203;
+    private final short valLen = 3;
+    private final float val1 = 0x01020304;
+    private final short val1Len = 4;
+
+    private final BgpLinkAttrMaxLinkBandwidth data = BgpLinkAttrMaxLinkBandwidth
+            .of(val, valLen);
+    private final BgpLinkAttrMaxLinkBandwidth sameAsData = BgpLinkAttrMaxLinkBandwidth
+            .of(val, valLen);
+    private final BgpLinkAttrMaxLinkBandwidth diffData = BgpLinkAttrMaxLinkBandwidth
+            .of(val1, val1Len);
+
+    @Test
+    public void basics() {
+        new EqualsTester().addEqualityGroup(data, sameAsData)
+        .addEqualityGroup(diffData).testEquals();
+    }
+}
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