Initial skeleton of BgpRouter app.

Added BGP tunnelling and received routes.
Added pushing groups and can now ping through the router.

Change-Id: I21a265bd72e40fc430bd392201fadccbdd67be94
diff --git a/apps/bgprouter/src/main/java/org/onosproject/bgprouter/BgpRouter.java b/apps/bgprouter/src/main/java/org/onosproject/bgprouter/BgpRouter.java
new file mode 100644
index 0000000..22389c3
--- /dev/null
+++ b/apps/bgprouter/src/main/java/org/onosproject/bgprouter/BgpRouter.java
@@ -0,0 +1,227 @@
+/*
+ * Copyright 2015 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.bgprouter;
+
+import com.google.common.collect.ConcurrentHashMultiset;
+import com.google.common.collect.Multiset;
+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.DeviceId;
+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.FlowRuleService;
+import org.onosproject.net.flow.TrafficSelector;
+import org.onosproject.net.flow.TrafficTreatment;
+import org.onosproject.net.group.DefaultGroupBucket;
+import org.onosproject.net.group.DefaultGroupDescription;
+import org.onosproject.net.group.Group;
+import org.onosproject.net.group.GroupBucket;
+import org.onosproject.net.group.GroupBuckets;
+import org.onosproject.net.group.GroupDescription;
+import org.onosproject.net.group.GroupKey;
+import org.onosproject.net.group.GroupService;
+import org.onosproject.net.packet.PacketService;
+import org.onosproject.routingapi.FibListener;
+import org.onosproject.routingapi.FibUpdate;
+import org.onosproject.routingapi.RoutingService;
+import org.onosproject.routingapi.config.Interface;
+import org.onosproject.routingapi.config.RoutingConfigurationService;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * BgpRouter component.
+ */
+@Component(immediate = true)
+public class BgpRouter {
+
+    private static final Logger log = LoggerFactory.getLogger(BgpRouter.class);
+
+    private static final String BGP_ROUTER_APP = "org.onosproject.bgprouter";
+
+    private static final int PRIORITY = 1;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected CoreService coreService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected FlowRuleService flowService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected GroupService groupService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected RoutingService routingService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected RoutingConfigurationService configService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected PacketService packetService;
+
+    private ApplicationId appId;
+
+    private final Multiset<NextHop> nextHops = ConcurrentHashMultiset.create();
+    private final Map<NextHop, NextHopGroupKey> groups = new HashMap<>();
+
+    private DeviceId deviceId = DeviceId.deviceId("of:00000000000000a1"); // TODO config
+
+    private TunnellingConnectivityManager connectivityManager;
+
+    @Activate
+    protected void activate() {
+        log.info("Bgp1Router started");
+        appId = coreService.registerApplication(BGP_ROUTER_APP);
+
+        connectivityManager = new TunnellingConnectivityManager(appId,
+                                                                configService,
+                                                                packetService);
+
+        routingService.start(new InternalFibListener());
+
+        connectivityManager.start();
+
+        log.info("BgpRouter started");
+    }
+
+    @Deactivate
+    protected void deactivate() {
+        routingService.stop();
+        connectivityManager.stop();
+
+        log.info("BgpRouter stopped");
+    }
+
+    private void updateFibEntry(Collection<FibUpdate> updates) {
+        for (FibUpdate update : updates) {
+            NextHop nextHop = new NextHop(update.entry().nextHopIp(),
+                                          update.entry().nextHopMac());
+
+            addNextHop(nextHop);
+
+            TrafficSelector selector = DefaultTrafficSelector.builder()
+                    .matchEthType(Ethernet.TYPE_IPV4)
+                    .matchIPDst(update.entry().prefix())
+                    .build();
+
+            // TODO ensure group exists
+            NextHopGroupKey groupKey = groups.get(nextHop);
+            Group group = groupService.getGroup(deviceId, groupKey);
+            if (group == null) {
+                // TODO handle this
+                log.warn("oops, group {} wasn't there");
+                continue;
+            }
+
+            TrafficTreatment treatment = DefaultTrafficTreatment.builder()
+                    .group(group.id())
+                    .build();
+
+            FlowRule flowRule = new DefaultFlowRule(deviceId, selector, treatment,
+                                                    PRIORITY, appId, 0, true,
+                                                    FlowRule.Type.IP);
+
+            flowService.applyFlowRules(flowRule);
+        }
+    }
+
+    private void deleteFibEntry(Collection<FibUpdate> withdraws) {
+        for (FibUpdate update : withdraws) {
+            NextHop nextHop = new NextHop(update.entry().nextHopIp(),
+                                          update.entry().nextHopMac());
+
+            deleteNextHop(nextHop);
+
+            TrafficSelector selector = DefaultTrafficSelector.builder()
+                    .matchIPDst(update.entry().prefix())
+                    .build();
+
+            FlowRule flowRule = new DefaultFlowRule(deviceId, selector, null,
+                                                    PRIORITY, appId, 0, true,
+                                                    FlowRule.Type.IP);
+
+            flowService.removeFlowRules(flowRule);
+        }
+    }
+
+    private void addNextHop(NextHop nextHop) {
+        if (nextHops.add(nextHop, 1) == 0) {
+            // There was no next hop in the multiset
+
+            Interface egressIntf = configService.getMatchingInterface(nextHop.ip());
+            if (egressIntf == null) {
+                log.warn("no egress interface found for {}", nextHop);
+                return;
+            }
+
+            NextHopGroupKey groupKey = new NextHopGroupKey(nextHop.ip());
+            groups.put(nextHop, groupKey);
+
+            TrafficTreatment treatment = DefaultTrafficTreatment.builder()
+                    .setEthSrc(egressIntf.mac())
+                    .setEthDst(nextHop.mac())
+                    .setVlanId(egressIntf.vlan())
+                    .setOutput(egressIntf.connectPoint().port())
+                    .build();
+
+            GroupBucket bucket = DefaultGroupBucket.createIndirectGroupBucket(treatment);
+
+            GroupDescription groupDescription
+                    = new DefaultGroupDescription(deviceId,
+                                                  GroupDescription.Type.INDIRECT,
+                                                  new GroupBuckets(Collections
+                                                                           .singletonList(bucket)),
+                                                  groupKey,
+                                                  appId);
+
+            groupService.addGroup(groupDescription);
+        }
+    }
+
+    private void deleteNextHop(NextHop nextHop) {
+        if (nextHops.remove(nextHop, 1) <= 1) {
+            // There was one or less next hops, so there are now none
+
+            log.debug("removing group");
+
+            GroupKey groupKey = groups.remove(nextHop);
+            groupService.removeGroup(deviceId, groupKey, appId);
+        }
+    }
+
+    private class InternalFibListener implements FibListener {
+
+        @Override
+        public void update(Collection<FibUpdate> updates,
+                           Collection<FibUpdate> withdraws) {
+            BgpRouter.this.deleteFibEntry(withdraws);
+            BgpRouter.this.updateFibEntry(updates);
+        }
+    }
+}