Pier | 1f87aca | 2018-03-14 16:47:32 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2018-present Open Networking Foundation |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package org.onosproject.segmentrouting; |
| 18 | |
| 19 | import org.onlab.graph.DefaultEdgeWeigher; |
| 20 | import org.onlab.graph.ScalarWeight; |
| 21 | import org.onlab.graph.Weight; |
| 22 | import org.onosproject.net.DeviceId; |
| 23 | import org.onosproject.net.Link; |
| 24 | import org.onosproject.net.PortNumber; |
| 25 | import org.onosproject.net.topology.LinkWeigher; |
| 26 | import org.onosproject.net.topology.TopologyEdge; |
| 27 | import org.onosproject.net.topology.TopologyVertex; |
| 28 | import org.onosproject.segmentrouting.config.DeviceConfigNotFoundException; |
| 29 | |
| 30 | import java.util.Set; |
| 31 | |
| 32 | /** |
| 33 | * Link weigher for multicast related path computations. |
| 34 | */ |
| 35 | public final class SRLinkWeigher |
| 36 | extends DefaultEdgeWeigher<TopologyVertex, TopologyEdge> |
| 37 | implements LinkWeigher { |
| 38 | |
| 39 | private final SegmentRoutingManager srManager; |
| 40 | private final DeviceId srcPath; |
| 41 | private final Set<Link> linksToEnforce; |
| 42 | |
| 43 | // Weight for the link to avoids. The high level idea is to build |
| 44 | // a constrained shortest path computation. 100 should provide a good |
| 45 | // threshold |
| 46 | public static final ScalarWeight LINK_TO_AVOID_WEIGHT = new ScalarWeight(HOP_WEIGHT_VALUE + 100); |
| 47 | |
| 48 | /** |
| 49 | * Creates a SRLinkWeigher object. |
| 50 | * |
| 51 | * @param srManager SegmentRoutingManager object |
| 52 | * @param srcPath the source of the paths |
| 53 | * @param linksToEnforce links to be enforced by the path computation |
| 54 | */ |
| 55 | public SRLinkWeigher(SegmentRoutingManager srManager, DeviceId srcPath, |
| 56 | Set<Link> linksToEnforce) { |
| 57 | this.srManager = srManager; |
| 58 | this.srcPath = srcPath; |
| 59 | this.linksToEnforce = linksToEnforce; |
| 60 | } |
| 61 | |
| 62 | @Override |
| 63 | public Weight weight(TopologyEdge edge) { |
| 64 | // 1) We need to avoid some particular paths like leaf-spine-leaf-* |
| 65 | // 2) Properly handle the pair links |
| 66 | |
| 67 | // If the link is a pair link just return infinite value |
| 68 | if (isPairLink(edge.link())) { |
| 69 | return ScalarWeight.NON_VIABLE_WEIGHT; |
| 70 | } |
| 71 | |
| 72 | // To avoid that the paths go through other leaves we need to influence |
| 73 | // the path computation to return infinite value for all other links having |
| 74 | // as a src a leaf different from the source we are passing to the weigher |
| 75 | DeviceId srcDeviceLink = edge.link().src().deviceId(); |
| 76 | // Identify the link as leaf-spine link |
| 77 | boolean isLeafSpine; |
| 78 | try { |
| 79 | isLeafSpine = srManager.deviceConfiguration().isEdgeDevice(srcDeviceLink); |
| 80 | } catch (DeviceConfigNotFoundException e) { |
| 81 | isLeafSpine = false; |
| 82 | } |
| 83 | // If it is not the source just return infinite value |
| 84 | if (isLeafSpine && !srcDeviceLink.equals(srcPath)) { |
| 85 | return ScalarWeight.NON_VIABLE_WEIGHT; |
| 86 | } |
| 87 | |
| 88 | // If the links are not in the list of the links to be enforce |
| 89 | if (!linksToEnforce.isEmpty() && !linksToEnforce.contains(edge.link())) { |
| 90 | // 100 should be a good confidence threshold |
| 91 | return LINK_TO_AVOID_WEIGHT; |
| 92 | } |
| 93 | |
| 94 | // All other cases we return |
| 95 | return new ScalarWeight(HOP_WEIGHT_VALUE); |
| 96 | } |
| 97 | |
| 98 | // Utility method to verify is a link is a pair-link |
| 99 | private boolean isPairLink(Link link) { |
| 100 | // Take src id, src port, dst id and dst port |
| 101 | final DeviceId srcId = link.src().deviceId(); |
| 102 | final PortNumber srcPort = link.src().port(); |
| 103 | final DeviceId dstId = link.dst().deviceId(); |
| 104 | final PortNumber dstPort = link.dst().port(); |
| 105 | // init as true |
| 106 | boolean isPairLink = true; |
| 107 | try { |
| 108 | // If one of this condition is not true; it is not a pair link |
| 109 | if (!(srManager.deviceConfiguration().isEdgeDevice(srcId) && |
| 110 | srManager.deviceConfiguration().isEdgeDevice(dstId) && |
| 111 | srManager.deviceConfiguration().getPairDeviceId(srcId).equals(dstId) && |
| 112 | srManager.deviceConfiguration().getPairLocalPort(srcId).equals(srcPort) && |
| 113 | srManager.deviceConfiguration().getPairLocalPort(dstId).equals(dstPort))) { |
| 114 | isPairLink = false; |
| 115 | } |
| 116 | } catch (DeviceConfigNotFoundException e) { |
| 117 | // Configuration not provided |
| 118 | isPairLink = false; |
| 119 | } |
| 120 | return isPairLink; |
| 121 | } |
| 122 | |
| 123 | } |