ONOS-631 #Initial MPLS intent implementation

Change-Id: I6f906b953f06f395cc67e612648802e333c0e581
diff --git a/core/net/src/main/java/org/onosproject/net/intent/impl/MplsIntentCompiler.java b/core/net/src/main/java/org/onosproject/net/intent/impl/MplsIntentCompiler.java
new file mode 100644
index 0000000..b8796d97
--- /dev/null
+++ b/core/net/src/main/java/org/onosproject/net/intent/impl/MplsIntentCompiler.java
@@ -0,0 +1,85 @@
+package org.onosproject.net.intent.impl;
+
+import static java.util.Arrays.asList;
+import static org.onosproject.net.DefaultEdgeLink.createEdgeLink;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Set;
+
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.onosproject.net.ConnectPoint;
+import org.onosproject.net.DefaultPath;
+import org.onosproject.net.Link;
+import org.onosproject.net.Path;
+import org.onosproject.net.intent.Intent;
+import org.onosproject.net.intent.MplsIntent;
+import org.onosproject.net.intent.MplsPathIntent;
+import org.onosproject.net.provider.ProviderId;
+import org.onosproject.net.resource.LinkResourceAllocations;
+
+
+@Component(immediate = true)
+public class MplsIntentCompiler  extends ConnectivityIntentCompiler<MplsIntent> {
+
+    // TODO: use off-the-shell core provider ID
+    private static final ProviderId PID =
+            new ProviderId("core", "org.onosproject.core", true);
+    // TODO: consider whether the default cost is appropriate or not
+    public static final int DEFAULT_COST = 1;
+
+
+    @Activate
+    public void activate() {
+        intentManager.registerCompiler(MplsIntent.class, this);
+    }
+
+    @Deactivate
+    public void deactivate() {
+        intentManager.unregisterCompiler(MplsIntent.class);
+    }
+
+    @Override
+    public List<Intent> compile(MplsIntent intent, List<Intent> installable,
+                                Set<LinkResourceAllocations> resources) {
+        ConnectPoint ingressPoint = intent.ingressPoint();
+        ConnectPoint egressPoint = intent.egressPoint();
+
+        if (ingressPoint.deviceId().equals(egressPoint.deviceId())) {
+            List<Link> links = asList(createEdgeLink(ingressPoint, true), createEdgeLink(egressPoint, false));
+            return asList(createPathIntent(new DefaultPath(PID, links, DEFAULT_COST), intent));
+        }
+
+        List<Link> links = new ArrayList<>();
+        Path path = getPath(intent, ingressPoint.deviceId(),
+                egressPoint.deviceId());
+
+        links.add(createEdgeLink(ingressPoint, true));
+        links.addAll(path.links());
+
+        links.add(createEdgeLink(egressPoint, false));
+
+        return asList(createPathIntent(new DefaultPath(PID, links, path.cost(),
+                                                       path.annotations()), intent));
+    }
+
+    /**
+     * Creates a path intent from the specified path and original
+     * connectivity intent.
+     *
+     * @param path   path to create an intent for
+     * @param intent original intent
+     */
+    private Intent createPathIntent(Path path,
+                                    MplsIntent intent) {
+        return new MplsPathIntent(intent.appId(),
+                              intent.selector(), intent.treatment(), path,
+                              intent.ingressLabel(), intent.egressLabel(),
+                              intent.constraints());
+    }
+
+
+}
diff --git a/core/net/src/main/java/org/onosproject/net/intent/impl/MplsPathIntentInstaller.java b/core/net/src/main/java/org/onosproject/net/intent/impl/MplsPathIntentInstaller.java
new file mode 100644
index 0000000..09c6551
--- /dev/null
+++ b/core/net/src/main/java/org/onosproject/net/intent/impl/MplsPathIntentInstaller.java
@@ -0,0 +1,296 @@
+package org.onosproject.net.intent.impl;
+
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.util.Iterator;
+import java.util.List;
+import java.util.Set;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.onlab.packet.Ethernet;
+import org.onosproject.core.ApplicationId;
+import org.onosproject.core.CoreService;
+import org.onosproject.net.ConnectPoint;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.Link;
+import org.onosproject.net.PortNumber;
+import org.onosproject.net.flow.DefaultFlowRule;
+import org.onosproject.net.flow.DefaultTrafficSelector;
+import org.onosproject.net.flow.DefaultTrafficTreatment;
+import org.onosproject.net.flow.FlowRule;
+import org.onosproject.net.flow.FlowRuleBatchEntry;
+import org.onosproject.net.flow.FlowRuleBatchOperation;
+import org.onosproject.net.flow.TrafficSelector;
+import org.onosproject.net.flow.TrafficTreatment;
+import org.onosproject.net.flow.FlowRuleBatchEntry.FlowRuleOperation;
+import org.onosproject.net.flow.criteria.Criteria.EthTypeCriterion;
+import org.onosproject.net.flow.criteria.Criterion;
+import org.onosproject.net.flow.criteria.Criterion.Type;
+import org.onosproject.net.intent.IntentExtensionService;
+import org.onosproject.net.intent.IntentInstaller;
+import org.onosproject.net.intent.MplsPathIntent;
+import org.onosproject.net.link.LinkStore;
+import org.onosproject.net.resource.DefaultLinkResourceRequest;
+import org.onosproject.net.resource.LinkResourceAllocations;
+import org.onosproject.net.resource.LinkResourceRequest;
+import org.onosproject.net.resource.LinkResourceService;
+import org.onosproject.net.resource.MplsLabel;
+import org.onosproject.net.resource.MplsLabelResourceAllocation;
+import org.onosproject.net.resource.ResourceAllocation;
+import org.onosproject.net.resource.ResourceType;
+import org.slf4j.Logger;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import com.google.common.collect.Lists;
+import com.google.common.collect.Sets;
+
+/**
+ * Installer for {@link MplsPathIntent packet path connectivity intents}.
+ */
+@Component(immediate = true)
+public class MplsPathIntentInstaller implements IntentInstaller<MplsPathIntent> {
+
+    private final Logger log = getLogger(getClass());
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected IntentExtensionService intentManager;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected CoreService coreService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected LinkResourceService resourceService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected LinkStore linkStore;
+
+    protected ApplicationId appId;
+
+    @Activate
+    public void activate() {
+        appId = coreService.registerApplication("org.onosproject.net.intent");
+        intentManager.registerInstaller(MplsPathIntent.class, this);
+    }
+
+    @Deactivate
+    public void deactivate() {
+        intentManager.unregisterInstaller(MplsPathIntent.class);
+    }
+
+    @Override
+    public List<FlowRuleBatchOperation> install(MplsPathIntent intent) {
+        LinkResourceAllocations allocations = assignMplsLabel(intent);
+        return generateRules(intent, allocations, FlowRuleOperation.ADD);
+
+    }
+
+    @Override
+    public List<FlowRuleBatchOperation> uninstall(MplsPathIntent intent) {
+        LinkResourceAllocations allocations = resourceService
+                .getAllocations(intent.id());
+        resourceService.releaseResources(allocations);
+
+        List<FlowRuleBatchOperation> rules = generateRules(intent,
+                                                           allocations,
+                                                           FlowRuleOperation.REMOVE);
+        return rules;
+    }
+
+    @Override
+    public List<FlowRuleBatchOperation> replace(MplsPathIntent oldIntent,
+                                                MplsPathIntent newIntent) {
+
+        List<FlowRuleBatchOperation> batches = Lists.newArrayList();
+        batches.addAll(uninstall(oldIntent));
+        batches.addAll(install(newIntent));
+        return batches;
+    }
+
+    private LinkResourceAllocations assignMplsLabel(MplsPathIntent intent) {
+
+        // TODO: do it better... Suggestions?
+        Set<Link> linkRequest = Sets.newHashSetWithExpectedSize(intent.path()
+                .links().size() - 2);
+        for (int i = 1; i <= intent.path().links().size() - 2; i++) {
+            Link link = intent.path().links().get(i);
+            linkRequest.add(link);
+            // add the inverse link. I want that the label is reserved both for
+            // the direct and inverse link
+            linkRequest.add(linkStore.getLink(link.dst(), link.src()));
+        }
+
+        LinkResourceRequest.Builder request = DefaultLinkResourceRequest
+                .builder(intent.id(), linkRequest).addMplsRequest();
+        LinkResourceAllocations reqMpls = resourceService
+                .requestResources(request.build());
+        return reqMpls;
+    }
+
+    private MplsLabel getMplsLabel(LinkResourceAllocations allocations,
+                                   Link link) {
+
+        for (ResourceAllocation allocation : allocations
+                .getResourceAllocation(link)) {
+            if (allocation.type() == ResourceType.MPLS_LABEL) {
+                return ((MplsLabelResourceAllocation) allocation).mplsLabel();
+
+            }
+        }
+        log.warn("MPLS label was not assigned successfully");
+        return null;
+    }
+
+    private List<FlowRuleBatchOperation> generateRules(MplsPathIntent intent,
+                                                       LinkResourceAllocations allocations,
+                                                       FlowRuleOperation operation) {
+
+        Iterator<Link> links = intent.path().links().iterator();
+        Link srcLink = links.next();
+        ConnectPoint prev = srcLink.dst();
+
+        Link link = links.next();
+        // List of flow rules to be installed
+        List<FlowRuleBatchEntry> rules = Lists.newLinkedList();
+
+        // Ingress traffic
+        // Get the new MPLS label
+        MplsLabel mpls = getMplsLabel(allocations, link);
+        checkNotNull(mpls);
+        MplsLabel prevLabel = mpls;
+        rules.add(ingressFlow(prev.port(), link, intent, mpls, operation));
+
+        prev = link.dst();
+
+        while (links.hasNext()) {
+
+            link = links.next();
+
+            if (links.hasNext()) {
+                // Transit traffic
+                // Get the new MPLS label
+                mpls = getMplsLabel(allocations, link);
+                checkNotNull(mpls);
+                rules.add(transitFlow(prev.port(), link, intent,
+                                      prevLabel, mpls, operation));
+                prevLabel = mpls;
+
+            } else {
+                // Egress traffic
+                rules.add(egressFlow(prev.port(), link, intent,
+                                     prevLabel, operation));
+            }
+
+            prev = link.dst();
+        }
+        return Lists.newArrayList(new FlowRuleBatchOperation(rules, null, 0));
+    }
+
+    private FlowRuleBatchEntry ingressFlow(PortNumber inPort, Link link,
+                                           MplsPathIntent intent,
+                                           MplsLabel label,
+                                           FlowRuleOperation operation) {
+
+        TrafficSelector.Builder ingressSelector = DefaultTrafficSelector
+                .builder(intent.selector());
+        TrafficTreatment.Builder treat = DefaultTrafficTreatment.builder();
+        ingressSelector.matchInPort(inPort);
+
+        if (intent.ingressLabel().isPresent()) {
+            ingressSelector.matchEthType(Ethernet.MPLS_UNICAST)
+                    .matchMplsLabel(intent.ingressLabel().get());
+
+            // Swap the MPLS label
+            treat.setMpls(label.label());
+        } else {
+            // Push and set the MPLS label
+            treat.pushMpls().setMpls(label.label());
+        }
+        // Add the output action
+        treat.setOutput(link.src().port());
+
+        return flowRuleBatchEntry(intent, link.src().deviceId(),
+                                  ingressSelector.build(), treat.build(),
+                                  operation);
+    }
+
+    private FlowRuleBatchEntry transitFlow(PortNumber inPort, Link link,
+                                           MplsPathIntent intent,
+                                           MplsLabel prevLabel,
+                                           MplsLabel outLabel,
+                                           FlowRuleOperation operation) {
+
+        // Ignore the ingress Traffic Selector and use only the MPLS label
+        // assigned in the previous link
+        TrafficSelector.Builder selector = DefaultTrafficSelector.builder();
+        selector.matchInPort(inPort).matchEthType(Ethernet.MPLS_UNICAST)
+                .matchMplsLabel(prevLabel.label());
+        TrafficTreatment.Builder treat = DefaultTrafficTreatment.builder();
+
+        // Set the new label only if the label on the packet is
+        // different
+        if (prevLabel.equals(outLabel)) {
+            treat.setMpls(outLabel.label());
+        }
+
+        treat.setOutput(link.src().port());
+        return flowRuleBatchEntry(intent, link.src().deviceId(),
+                                  selector.build(), treat.build(), operation);
+    }
+
+    private FlowRuleBatchEntry egressFlow(PortNumber inPort, Link link,
+                                          MplsPathIntent intent,
+                                          MplsLabel prevLabel,
+                                          FlowRuleOperation operation) {
+        // egress point: either set the egress MPLS label or pop the
+        // MPLS label based on the intent annotations
+
+        TrafficSelector.Builder selector = DefaultTrafficSelector.builder();
+        selector.matchInPort(inPort).matchEthType(Ethernet.MPLS_UNICAST)
+                .matchMplsLabel(prevLabel.label());
+
+        // apply the intent's treatments
+        TrafficTreatment.Builder treat = DefaultTrafficTreatment.builder(intent
+                .treatment());
+
+        if (intent.egressLabel().isPresent()) {
+            treat.setMpls(intent.egressLabel().get());
+        } else {
+            // if the ingress ethertype is defined, the egress traffic
+            // will be use that value, otherwise the IPv4 ethertype is used.
+            Criterion c = intent.selector().getCriterion(Type.ETH_TYPE);
+            if (c != null && c instanceof EthTypeCriterion) {
+                EthTypeCriterion ethertype = (EthTypeCriterion) c;
+                treat.popMpls((short) ethertype.ethType());
+            } else {
+                treat.popMpls(Ethernet.TYPE_IPV4);
+            }
+
+        }
+        treat.setOutput(link.src().port());
+        return flowRuleBatchEntry(intent, link.src().deviceId(),
+                                  selector.build(), treat.build(), operation);
+    }
+
+    protected FlowRuleBatchEntry flowRuleBatchEntry(MplsPathIntent intent,
+                                                    DeviceId deviceId,
+                                                    TrafficSelector selector,
+                                                    TrafficTreatment treat,
+                                                    FlowRuleOperation operation) {
+        FlowRule rule = new DefaultFlowRule(
+                                            deviceId,
+                                            selector,
+                                            treat,
+                                            123, // FIXME 123
+                                            appId,
+                                            0,
+                                            true);
+        return new FlowRuleBatchEntry(operation, rule, intent.id()
+                .fingerprint());
+
+    }
+}
diff --git a/core/net/src/main/java/org/onosproject/net/resource/impl/LinkResourceManager.java b/core/net/src/main/java/org/onosproject/net/resource/impl/LinkResourceManager.java
index f583ebd..fadb152 100644
--- a/core/net/src/main/java/org/onosproject/net/resource/impl/LinkResourceManager.java
+++ b/core/net/src/main/java/org/onosproject/net/resource/impl/LinkResourceManager.java
@@ -49,6 +49,9 @@
 import org.onosproject.net.resource.LinkResourceService;
 import org.onosproject.net.resource.LinkResourceStore;
 import org.onosproject.net.resource.LinkResourceStoreDelegate;
+import org.onosproject.net.resource.MplsLabel;
+import org.onosproject.net.resource.MplsLabelResourceAllocation;
+import org.onosproject.net.resource.MplsLabelResourceRequest;
 import org.onosproject.net.resource.ResourceAllocation;
 import org.onosproject.net.resource.ResourceRequest;
 import org.onosproject.net.resource.ResourceType;
@@ -104,6 +107,7 @@
         return lambdas;
     }
 
+
     /**
      * Returns available lambdas on specified links.
      *
@@ -121,13 +125,36 @@
         return lambdas;
     }
 
+
+    /**
+     * Returns available MPLS label on specified link.
+     *
+     * @param link the link
+     * @return available MPLS labels on specified link
+     */
+    private Iterable<MplsLabel> getAvailableMplsLabels(Link link) {
+        Set<ResourceAllocation> resAllocs = store.getFreeResources(link);
+        if (resAllocs == null) {
+            return Collections.emptySet();
+        }
+        Set<MplsLabel> mplsLabels = new HashSet<>();
+        for (ResourceAllocation res : resAllocs) {
+            if (res.type() == ResourceType.MPLS_LABEL) {
+
+                mplsLabels.add(((MplsLabelResourceAllocation) res).mplsLabel());
+            }
+        }
+
+        return mplsLabels;
+    }
+
     @Override
     public LinkResourceAllocations requestResources(LinkResourceRequest req) {
         // TODO Concatenate multiple bandwidth requests.
         // TODO Support multiple lambda resource requests.
         // TODO Throw appropriate exception.
-
         Set<ResourceAllocation> allocs = new HashSet<>();
+        Map<Link, Set<ResourceAllocation>> allocsPerLink = new HashMap<>();
         for (ResourceRequest r : req.resources()) {
             switch (r.type()) {
             case BANDWIDTH:
@@ -144,6 +171,24 @@
                     return null;
                 }
                 break;
+            case MPLS_LABEL:
+                for (Link link : req.links()) {
+                    if (allocsPerLink.get(link) == null) {
+                        allocsPerLink.put(link,
+                                          new HashSet<ResourceAllocation>());
+                    }
+                    Iterator<MplsLabel> mplsIter = getAvailableMplsLabels(link)
+                            .iterator();
+                    if (mplsIter.hasNext()) {
+                        allocsPerLink.get(link)
+                                .add(new MplsLabelResourceAllocation(mplsIter
+                                             .next()));
+                    } else {
+                        log.info("Failed to allocate MPLS resource.");
+                        break;
+                    }
+                }
+                break;
             default:
                 break;
             }
@@ -151,7 +196,8 @@
 
         Map<Link, Set<ResourceAllocation>> allocations = new HashMap<>();
         for (Link link : req.links()) {
-            allocations.put(link, allocs);
+            allocations.put(link, new HashSet<ResourceAllocation>(allocs));
+            allocations.get(link).addAll(allocsPerLink.get(link));
         }
         LinkResourceAllocations result =
                 new DefaultLinkResourceAllocations(req, allocations);
@@ -203,6 +249,8 @@
             case LAMBDA:
                 result.add(new LambdaResourceRequest());
                 break;
+            case MPLS_LABEL:
+                result.add(new MplsLabelResourceRequest());
             default:
                 break;
             }