Implementation of the NeighbourResolutionService.

Change-Id: I41fc48578df3027ec71ee7369171c8988ee7a85e

@@ -21,36 +21,54 @@ import org.onosproject.net.host.HostService;
 
 import java.util.Set;
 
+import static org.onlab.packet.VlanId.vlanId;
 import static org.onosproject.net.HostId.hostId;
 
 /**
- * Default neighbour message handler which implements basic proxying on a flat
+ * Default neighbour message handler which implements basic proxying on an
  * L2 network (i.e. ProxyArp behaviour).
  */
 public class DefaultNeighbourMessageHandler implements NeighbourMessageHandler {
     @Override
     public void handleMessage(NeighbourMessageContext context, HostService hostService) {
-        // See if we have the target host in the host store
-        Set<Host> hosts = hostService.getHostsByIp(context.target());
+        switch (context.type()) {
+        case REPLY:
+            Host h = hostService.getHost(hostId(context.packet().getDestinationMAC(),
+                    vlanId(context.packet().getVlanID())));
 
-        Host dst = null;
-        Host src = hostService.getHost(hostId(context.srcMac(), context.vlan()));
+            if (h == null) {
+                context.flood();
+            } else {
+                context.proxy(h.location());
+            }
+            break;
+        case REQUEST:
+            // See if we have the target host in the host store
+            Set<Host> hosts = hostService.getHostsByIp(context.target());
+
+            Host dst = null;
+            Host src = hostService.getHost(hostId(context.srcMac(), context.vlan()));
 
-        for (Host host : hosts) {
-            if (host.vlan().equals(context.vlan())) {
-                dst = host;
-                break;
+            for (Host host : hosts) {
+                if (host.vlan().equals(context.vlan())) {
+                    dst = host;
+                    break;
+                }
+            }
+
+            if (src != null && dst != null) {
+                // We know the target host so we can respond
+                context.reply(dst.mac());
+                return;
             }
-        }
 
-        if (src != null && dst != null) {
-            // We know the target host so we can respond
-            context.reply(dst.mac());
-            return;
+            // The request couldn't be resolved.
+            // Flood the request on all ports except the incoming port.
+            context.flood();
+            break;
+        default:
+            break;
         }
 
-        // The request couldn't be resolved.
-        // Flood the request on all ports except the incoming port.
-        context.flood();
     }
 }

@@ -24,8 +24,6 @@ import org.onlab.packet.VlanId;
 import org.onosproject.incubator.net.intf.Interface;
 import org.onosproject.net.ConnectPoint;
 
-import static com.google.common.base.Preconditions.checkState;
-
 /**
  * Context of an incoming neighbor message (e.g. ARP, NDP).
  *
@@ -34,156 +32,91 @@ import static com.google.common.base.Preconditions.checkState;
  * response to the incoming message.</p>
  */
 @Beta
-public class NeighbourMessageContext {
-
-    private final NeighbourProtocol protocol;
-    private final NeighbourMessageType type;
-
-    private final IpAddress target;
-    private final IpAddress sender;
-
-    private final Ethernet eth;
-    private final ConnectPoint inPort;
-
-    private final NeighbourMessageActions actions;
-
-    /**
-     * Creates a new neighbour message context.
-     *
-     * @param actions actions
-     * @param eth ethernet frame
-     * @param inPort incoming port
-     * @param protocol message protocol
-     * @param type message type
-     * @param target target IP address
-     * @param sender sender IP address
-     */
-    public NeighbourMessageContext(NeighbourMessageActions actions,
-                                   Ethernet eth, ConnectPoint inPort,
-                                   NeighbourProtocol protocol, NeighbourMessageType type,
-                                   IpAddress target, IpAddress sender) {
-        this.actions = actions;
-        this.eth = eth;
-        this.inPort = inPort;
-        this.protocol = protocol;
-        this.type = type;
-        this.target = target;
-        this.sender = sender;
-    }
-
+public interface NeighbourMessageContext {
     /**
      * Gets the port where the packet came in to the network.
      *
      * @return connect point
      */
-    public ConnectPoint inPort() {
-        return inPort;
-    }
+    ConnectPoint inPort();
 
     /**
      * Gets the full parsed representation of the packet.
      *
      * @return ethernet header
      */
-    public Ethernet packet() {
-        return eth;
-    }
+    Ethernet packet();
 
     /**
      * Gets the protocol of the packet.
      *
      * @return protocol
      */
-    public NeighbourProtocol protocol() {
-        return protocol;
-    }
+    NeighbourProtocol protocol();
 
     /**
      * Gets the message type of the packet.
      *
      * @return message type
      */
-    public NeighbourMessageType type() {
-        return type;
-    }
+    NeighbourMessageType type();
 
     /**
      * Gets the vlan of the packet, if any.
      *
      * @return vlan
      */
-    public VlanId vlan() {
-        return VlanId.vlanId(eth.getVlanID());
-    }
+    VlanId vlan();
 
     /**
      * Gets the source MAC address of the message.
      *
      * @return source MAC address
      */
-    public MacAddress srcMac() {
-        return MacAddress.valueOf(eth.getSourceMACAddress());
-    }
+    MacAddress srcMac();
 
     /**
      * Gets the target IP address of the message.
      *
      * @return target IP address
      */
-    public IpAddress target() {
-        return target;
-    }
+    IpAddress target();
 
     /**
      * Gets the source IP address of the message.
      *
      * @return source IP address
      */
-    public IpAddress sender() {
-        return sender;
-    }
+    IpAddress sender();
 
     /**
      * Proxies the message to a given output port.
      *
      * @param outPort output port
      */
-    public void proxy(ConnectPoint outPort) {
-        actions.proxy(this, outPort);
-    }
+    void proxy(ConnectPoint outPort);
 
     /**
      * Proxies the message to a given interface.
      *
      * @param outIntf output interface
      */
-    public void proxy(Interface outIntf) {
-        actions.proxy(this, outIntf);
-    }
+    void proxy(Interface outIntf);
 
     /**
      * Replies to the request message with a given MAC address.
      *
      * @param targetMac target MAC address
      */
-    public void reply(MacAddress targetMac) {
-        checkState(type == NeighbourMessageType.REQUEST, "can only reply to requests");
-
-        actions.reply(this, targetMac);
-    }
+    void reply(MacAddress targetMac);
 
     /**
      * Floods the incoming message out all ports except the input port.
      */
-    public void flood() {
-        actions.flood(this);
-    }
+    void flood();
 
     /**
      * Drops the incoming message.
      */
-    public void drop() {
-        actions.drop(this);
-    }
-
+    void drop();
 }

@@ -45,4 +45,20 @@ public interface NeighbourResolutionService {
      */
     void registerNeighbourHandler(Interface intf, NeighbourMessageHandler handler);
 
+    /**
+     * Unregisters a neighbour message handler that was assigned to a connect
+     * point.
+     *
+     * @param connectPoint connect point
+     * @param handler neighbour message handler
+     */
+    void unregisterNeighbourHandler(ConnectPoint connectPoint, NeighbourMessageHandler handler);
+
+    /**
+     * Unregisters a neighbour message handler that was assigned to an interface.
+     *
+     * @param intf interface
+     * @param handler neighbour message handler
+     */
+    void unregisterNeighbourHandler(Interface intf, NeighbourMessageHandler handler);
 }

+/*
+ * Copyright 2016-present 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.incubator.net.neighbour.impl;
+
+import com.google.common.annotations.Beta;
+import org.onlab.packet.ARP;
+import org.onlab.packet.Ethernet;
+import org.onlab.packet.ICMP6;
+import org.onlab.packet.IPv6;
+import org.onlab.packet.Ip4Address;
+import org.onlab.packet.Ip6Address;
+import org.onlab.packet.IpAddress;
+import org.onlab.packet.MacAddress;
+import org.onlab.packet.VlanId;
+import org.onlab.packet.ndp.NeighborSolicitation;
+import org.onosproject.incubator.net.intf.Interface;
+import org.onosproject.incubator.net.neighbour.NeighbourMessageActions;
+import org.onosproject.incubator.net.neighbour.NeighbourMessageContext;
+import org.onosproject.incubator.net.neighbour.NeighbourMessageType;
+import org.onosproject.incubator.net.neighbour.NeighbourProtocol;
+import org.onosproject.net.ConnectPoint;
+
+import static com.google.common.base.Preconditions.checkState;
+
+/**
+ * Default implementation of a neighbour message context.
+ */
+@Beta
+public class DefaultNeighbourMessageContext implements NeighbourMessageContext {
+
+    private final NeighbourProtocol protocol;
+    private final NeighbourMessageType type;
+
+    private final IpAddress target;
+    private final IpAddress sender;
+
+    private final Ethernet eth;
+    private final ConnectPoint inPort;
+
+    private final NeighbourMessageActions actions;
+
+    /**
+     * Creates a new neighbour message context.
+     *
+     * @param actions actions
+     * @param eth ethernet frame
+     * @param inPort incoming port
+     * @param protocol message protocol
+     * @param type message type
+     * @param target target IP address
+     * @param sender sender IP address
+     */
+    DefaultNeighbourMessageContext(NeighbourMessageActions actions,
+                                   Ethernet eth, ConnectPoint inPort,
+                                   NeighbourProtocol protocol,
+                                   NeighbourMessageType type,
+                                   IpAddress target, IpAddress sender) {
+        this.actions = actions;
+        this.eth = eth;
+        this.inPort = inPort;
+        this.protocol = protocol;
+        this.type = type;
+        this.target = target;
+        this.sender = sender;
+    }
+
+    @Override
+    public ConnectPoint inPort() {
+        return inPort;
+    }
+
+    @Override
+    public Ethernet packet() {
+        return eth;
+    }
+
+    @Override
+    public NeighbourProtocol protocol() {
+        return protocol;
+    }
+
+    @Override
+    public NeighbourMessageType type() {
+        return type;
+    }
+
+    @Override
+    public VlanId vlan() {
+        return VlanId.vlanId(eth.getVlanID());
+    }
+
+    @Override
+    public MacAddress srcMac() {
+        return MacAddress.valueOf(eth.getSourceMACAddress());
+    }
+
+    @Override
+    public IpAddress target() {
+        return target;
+    }
+
+    @Override
+    public IpAddress sender() {
+        return sender;
+    }
+
+    @Override
+    public void proxy(ConnectPoint outPort) {
+        actions.proxy(this, outPort);
+    }
+
+    @Override
+    public void proxy(Interface outIntf) {
+        actions.proxy(this, outIntf);
+    }
+
+    @Override
+    public void reply(MacAddress targetMac) {
+        checkState(type == NeighbourMessageType.REQUEST, "can only reply to requests");
+
+        actions.reply(this, targetMac);
+    }
+
+    @Override
+    public void flood() {
+        actions.flood(this);
+    }
+
+    @Override
+    public void drop() {
+        actions.drop(this);
+    }
+
+    /**
+     * Attempts to create a MessageContext for the given Ethernet frame. If the
+     * frame is a valid ARP or NDP request or response, a context will be
+     * created.
+     *
+     * @param eth input Ethernet frame
+     * @param inPort in port
+     * @return MessageContext if the packet was ARP or NDP, otherwise null
+     */
+    public static NeighbourMessageContext createContext(Ethernet eth,
+                                                        ConnectPoint inPort,
+                                                        NeighbourMessageActions actions) {
+        if (eth.getEtherType() == Ethernet.TYPE_ARP) {
+            return createArpContext(eth, inPort, actions);
+        } else if (eth.getEtherType() == Ethernet.TYPE_IPV6) {
+            return createNdpContext(eth, inPort, actions);
+        }
+
+        return null;
+    }
+
+    /**
+     * Extracts context information from ARP packets.
+     *
+     * @param eth input Ethernet frame that is thought to be ARP
+     * @param inPort in port
+     * @return MessageContext object if the packet was a valid ARP packet,
+     * otherwise null
+     */
+    private static NeighbourMessageContext createArpContext(Ethernet eth,
+                                                            ConnectPoint inPort,
+                                                            NeighbourMessageActions actions) {
+        if (eth.getEtherType() != Ethernet.TYPE_ARP) {
+            return null;
+        }
+
+        ARP arp = (ARP) eth.getPayload();
+
+        IpAddress target = Ip4Address.valueOf(arp.getTargetProtocolAddress());
+        IpAddress sender = Ip4Address.valueOf(arp.getSenderProtocolAddress());
+
+        NeighbourMessageType type;
+        if (arp.getOpCode() == ARP.OP_REQUEST) {
+            type = NeighbourMessageType.REQUEST;
+        } else if (arp.getOpCode() == ARP.OP_REPLY) {
+            type = NeighbourMessageType.REPLY;
+        } else {
+            return null;
+        }
+
+        return new DefaultNeighbourMessageContext(actions, eth, inPort,
+                NeighbourProtocol.ARP, type, target, sender);
+    }
+
+    /**
+     * Extracts context information from NDP packets.
+     *
+     * @param eth input Ethernet frame that is thought to be NDP
+     * @param inPort in port
+     * @return MessageContext object if the packet was a valid NDP packet,
+     * otherwise null
+     */
+    private static NeighbourMessageContext createNdpContext(Ethernet eth,
+                                                            ConnectPoint inPort,
+                                                            NeighbourMessageActions actions) {
+        if (eth.getEtherType() != Ethernet.TYPE_IPV6) {
+            return null;
+        }
+        IPv6 ipv6 = (IPv6) eth.getPayload();
+
+        if (ipv6.getNextHeader() != IPv6.PROTOCOL_ICMP6) {
+            return null;
+        }
+        ICMP6 icmpv6 = (ICMP6) ipv6.getPayload();
+
+        IpAddress sender = Ip6Address.valueOf(ipv6.getSourceAddress());
+        IpAddress target = null;
+
+        NeighbourMessageType type;
+        if (icmpv6.getIcmpType() == ICMP6.NEIGHBOR_SOLICITATION) {
+            type = NeighbourMessageType.REQUEST;
+            NeighborSolicitation nsol = (NeighborSolicitation) icmpv6.getPayload();
+            target = Ip6Address.valueOf(nsol.getTargetAddress());
+        } else if (icmpv6.getIcmpType() == ICMP6.NEIGHBOR_ADVERTISEMENT) {
+            type = NeighbourMessageType.REPLY;
+        } else {
+            return null;
+        }
+
+        return new DefaultNeighbourMessageContext(actions, eth, inPort,
+                NeighbourProtocol.NDP, type, target, sender);
+    }
+
+}

+/*
+ * Copyright 2016-present 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.
+ */
+
+/**
+ * Implementation of neighbour resolution service.
+ */
+package org.onosproject.incubator.net.neighbour.impl;