| /* |
| * Copyright 2017-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.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); |
| } |
| } |