| /* |
| * Copyright 2018-present Open Networking Foundation |
| * |
| * 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.segmentrouting; |
| |
| import org.onlab.graph.DefaultEdgeWeigher; |
| import org.onlab.graph.ScalarWeight; |
| import org.onlab.graph.Weight; |
| import org.onosproject.net.DeviceId; |
| import org.onosproject.net.Link; |
| import org.onosproject.net.PortNumber; |
| import org.onosproject.net.topology.LinkWeigher; |
| import org.onosproject.net.topology.TopologyEdge; |
| import org.onosproject.net.topology.TopologyVertex; |
| import org.onosproject.segmentrouting.config.DeviceConfigNotFoundException; |
| |
| import java.util.Set; |
| |
| /** |
| * Link weigher for multicast related path computations. |
| */ |
| public final class SRLinkWeigher |
| extends DefaultEdgeWeigher<TopologyVertex, TopologyEdge> |
| implements LinkWeigher { |
| |
| private final SegmentRoutingManager srManager; |
| private final DeviceId srcPath; |
| private final Set<Link> linksToEnforce; |
| |
| // Weight for the link to avoids. The high level idea is to build |
| // a constrained shortest path computation. 100 should provide a good |
| // threshold |
| public static final ScalarWeight LINK_TO_AVOID_WEIGHT = new ScalarWeight(HOP_WEIGHT_VALUE + 100); |
| |
| /** |
| * Creates a SRLinkWeigher object. |
| * |
| * @param srManager SegmentRoutingManager object |
| * @param srcPath the source of the paths |
| * @param linksToEnforce links to be enforced by the path computation |
| */ |
| public SRLinkWeigher(SegmentRoutingManager srManager, DeviceId srcPath, |
| Set<Link> linksToEnforce) { |
| this.srManager = srManager; |
| this.srcPath = srcPath; |
| this.linksToEnforce = linksToEnforce; |
| } |
| |
| @Override |
| public Weight weight(TopologyEdge edge) { |
| // 1) We need to avoid some particular paths like leaf-spine-leaf-* |
| // 2) Properly handle the pair links |
| |
| // If the link is a pair link just return infinite value |
| if (isPairLink(edge.link())) { |
| return ScalarWeight.NON_VIABLE_WEIGHT; |
| } |
| |
| // To avoid that the paths go through other leaves we need to influence |
| // the path computation to return infinite value for all other links having |
| // as a src a leaf different from the source we are passing to the weigher |
| DeviceId srcDeviceLink = edge.link().src().deviceId(); |
| // Identify the link as leaf-spine link |
| boolean isLeafSpine; |
| try { |
| isLeafSpine = srManager.deviceConfiguration().isEdgeDevice(srcDeviceLink); |
| } catch (DeviceConfigNotFoundException e) { |
| isLeafSpine = false; |
| } |
| // If it is not the source just return infinite value |
| if (isLeafSpine && !srcDeviceLink.equals(srcPath)) { |
| return ScalarWeight.NON_VIABLE_WEIGHT; |
| } |
| |
| // If the links are not in the list of the links to be enforce |
| if (!linksToEnforce.isEmpty() && !linksToEnforce.contains(edge.link())) { |
| // 100 should be a good confidence threshold |
| return LINK_TO_AVOID_WEIGHT; |
| } |
| |
| // All other cases we return |
| return new ScalarWeight(HOP_WEIGHT_VALUE); |
| } |
| |
| // Utility method to verify is a link is a pair-link |
| private boolean isPairLink(Link link) { |
| // Take src id, src port, dst id and dst port |
| final DeviceId srcId = link.src().deviceId(); |
| final PortNumber srcPort = link.src().port(); |
| final DeviceId dstId = link.dst().deviceId(); |
| final PortNumber dstPort = link.dst().port(); |
| // init as true |
| boolean isPairLink = true; |
| try { |
| // If one of this condition is not true; it is not a pair link |
| if (!(srManager.deviceConfiguration().isEdgeDevice(srcId) && |
| srManager.deviceConfiguration().isEdgeDevice(dstId) && |
| srManager.deviceConfiguration().getPairDeviceId(srcId).equals(dstId) && |
| srManager.deviceConfiguration().getPairLocalPort(srcId).equals(srcPort) && |
| srManager.deviceConfiguration().getPairLocalPort(dstId).equals(dstPort))) { |
| isPairLink = false; |
| } |
| } catch (DeviceConfigNotFoundException e) { |
| // Configuration not provided |
| isPairLink = false; |
| } |
| return isPairLink; |
| } |
| |
| } |