ONOS-631 #Initial MPLS intent implementation

Change-Id: I6f906b953f06f395cc67e612648802e333c0e581
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());
+
+    }
+}