FPM component that can decode routes from Quagga's FIB push interface.
Change-Id: I57bfd9273b81c8d368a59a3acea53486cb4acfc1
diff --git a/apps/routing/src/main/java/org/onosproject/routing/fpm/protocol/RouteAttribute.java b/apps/routing/src/main/java/org/onosproject/routing/fpm/protocol/RouteAttribute.java
new file mode 100644
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+++ b/apps/routing/src/main/java/org/onosproject/routing/fpm/protocol/RouteAttribute.java
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+/*
+ * Copyright 2016 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.routing.fpm.protocol;
+
+import com.google.common.collect.ImmutableMap;
+import org.onlab.packet.DeserializationException;
+
+import java.nio.ByteBuffer;
+import java.util.Map;
+
+import static org.onlab.packet.PacketUtils.checkInput;
+
+/**
+ * Route attribute header.
+ */
+public abstract class RouteAttribute {
+
+ public static final int ROUTE_ATTRIBUTE_HEADER_LENGTH = 4;
+
+ public static final int RTA_DST = 1;
+ public static final int RTA_OIF = 4;
+ public static final int RTA_GATEWAY = 5;
+ public static final int RTA_PRIORITY = 6;
+
+ private final int length;
+ private final int type;
+
+ private static final Map<Integer, RouteAttributeDecoder<?>> TYPE_DECODER_MAP
+ = ImmutableMap.<Integer, RouteAttributeDecoder<?>>builder()
+ .put(RTA_DST, RouteAttributeDst.decoder())
+ .put(RTA_OIF, RouteAttributeOif.decoder())
+ .put(RTA_GATEWAY, RouteAttributeGateway.decoder())
+ .put(RTA_PRIORITY, RouteAttributePriority.decoder())
+ .build();
+
+ /**
+ * Class constructor.
+ *
+ * @param length attribute length
+ * @param type attribute type
+ */
+ protected RouteAttribute(int length, int type) {
+ this.length = length;
+ this.type = type;
+ }
+
+ /**
+ * Returns the attribute length.
+ *
+ * @return length
+ */
+ public int length() {
+ return length;
+ }
+
+ /**
+ * Returns the attribute type.
+ *
+ * @return type
+ */
+ public int type() {
+ return type;
+ }
+
+ @Override
+ public abstract String toString();
+
+ /**
+ * Decodes a route attribute from an input buffer.
+ *
+ * @param buffer input buffer
+ * @param start starting position the route attribute message
+ * @param length length of the message
+ * @return route attribute message
+ * @throws DeserializationException if a route attribute could not be
+ * decoded from the input buffer
+ */
+ public static RouteAttribute decode(byte[] buffer, int start, int length)
+ throws DeserializationException {
+ checkInput(buffer, start, length, ROUTE_ATTRIBUTE_HEADER_LENGTH);
+
+ ByteBuffer bb = ByteBuffer.wrap(buffer, start, length);
+
+ int tlvLength = Short.reverseBytes(bb.getShort());
+ int type = Short.reverseBytes(bb.getShort());
+
+ if (bb.remaining() < tlvLength - ROUTE_ATTRIBUTE_HEADER_LENGTH) {
+ throw new DeserializationException(
+ "Incorrect buffer size when decoding route attribute");
+ }
+
+ byte[] value = new byte[tlvLength - ROUTE_ATTRIBUTE_HEADER_LENGTH];
+ bb.get(value);
+
+ RouteAttributeDecoder<?> decoder = TYPE_DECODER_MAP.get(type);
+ if (decoder == null) {
+ throw new DeserializationException(
+ "No decoder found for route attribute type " + type);
+ }
+
+ return decoder.decodeAttribute(tlvLength, type, value);
+ }
+}