1 files changed, 171 insertions, 0 deletions
diff --git a/framework/src/onos/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/IcmpHandler.java b/framework/src/onos/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/IcmpHandler.java
new file mode 100644
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+++ b/framework/src/onos/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/IcmpHandler.java
@@ -0,0 +1,171 @@
+/*
+ * 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.segmentrouting;
+
+import org.onlab.packet.Ethernet;
+import org.onlab.packet.ICMP;
+import org.onlab.packet.IPv4;
+import org.onlab.packet.Ip4Address;
+import org.onlab.packet.IpPrefix;
+import org.onlab.packet.MPLS;
+import org.onosproject.net.ConnectPoint;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.flow.DefaultTrafficTreatment;
+import org.onosproject.net.flow.TrafficTreatment;
+import org.onosproject.net.packet.DefaultOutboundPacket;
+import org.onosproject.net.packet.InboundPacket;
+import org.onosproject.net.packet.OutboundPacket;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.nio.ByteBuffer;
+import java.util.List;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+public class IcmpHandler {
+
+    private static Logger log = LoggerFactory.getLogger(IcmpHandler.class);
+    private SegmentRoutingManager srManager;
+    private DeviceConfiguration config;
+
+    /**
+     * Creates an IcmpHandler object.
+     *
+     * @param srManager SegmentRoutingManager object
+     */
+    public IcmpHandler(SegmentRoutingManager srManager) {
+        this.srManager = srManager;
+        this.config = checkNotNull(srManager.deviceConfiguration);
+    }
+
+    /**
+     * Process incoming ICMP packet.
+     * If it is an ICMP request to router or known host, then sends an ICMP response.
+     * If it is an ICMP packet to known host and forward the packet to the host.
+     * If it is an ICMP packet to unknown host in a subnet, then sends an ARP request
+     * to the subnet.
+     *
+     * @param pkt inbound packet
+     */
+    public void processPacketIn(InboundPacket pkt) {
+
+        Ethernet ethernet = pkt.parsed();
+        IPv4 ipv4 = (IPv4) ethernet.getPayload();
+
+        ConnectPoint connectPoint = pkt.receivedFrom();
+        DeviceId deviceId = connectPoint.deviceId();
+        Ip4Address destinationAddress =
+                Ip4Address.valueOf(ipv4.getDestinationAddress());
+        List<Ip4Address> gatewayIpAddresses = config.getSubnetGatewayIps(deviceId);
+        Ip4Address routerIp = config.getRouterIp(deviceId);
+        IpPrefix routerIpPrefix = IpPrefix.valueOf(routerIp, IpPrefix.MAX_INET_MASK_LENGTH);
+        Ip4Address routerIpAddress = routerIpPrefix.getIp4Prefix().address();
+
+        // ICMP to the router IP or gateway IP
+        if (((ICMP) ipv4.getPayload()).getIcmpType() == ICMP.TYPE_ECHO_REQUEST &&
+                (destinationAddress.equals(routerIpAddress) ||
+                        gatewayIpAddresses.contains(destinationAddress))) {
+            sendICMPResponse(ethernet, connectPoint);
+            // TODO: do we need to set the flow rule again ??
+
+        // ICMP for any known host
+        } else if (!srManager.hostService.getHostsByIp(destinationAddress).isEmpty()) {
+            srManager.ipHandler.forwardPackets(deviceId, destinationAddress);
+
+        // ICMP for an unknown host in the subnet of the router
+        } else if (config.inSameSubnet(deviceId, destinationAddress)) {
+            srManager.arpHandler.sendArpRequest(deviceId, destinationAddress, connectPoint);
+
+        // ICMP for an unknown host
+        } else {
+            log.debug("ICMP request for unknown host {} ", destinationAddress);
+            // Do nothing
+        }
+    }
+
+    private void sendICMPResponse(Ethernet icmpRequest, ConnectPoint outport) {
+
+        Ethernet icmpReplyEth = new Ethernet();
+
+        IPv4 icmpRequestIpv4 = (IPv4) icmpRequest.getPayload();
+        IPv4 icmpReplyIpv4 = new IPv4();
+
+        int destAddress = icmpRequestIpv4.getDestinationAddress();
+        icmpReplyIpv4.setDestinationAddress(icmpRequestIpv4.getSourceAddress());
+        icmpReplyIpv4.setSourceAddress(destAddress);
+        icmpReplyIpv4.setTtl((byte) 64);
+        icmpReplyIpv4.setChecksum((short) 0);
+
+        ICMP icmpReply = new ICMP();
+        icmpReply.setIcmpType(ICMP.TYPE_ECHO_REPLY);
+        icmpReply.setIcmpCode(ICMP.SUBTYPE_ECHO_REPLY);
+        icmpReply.setChecksum((short) 0);
+
+        icmpReplyIpv4.setPayload(icmpReply);
+
+        icmpReplyEth.setPayload(icmpReplyIpv4);
+        icmpReplyEth.setEtherType(Ethernet.TYPE_IPV4);
+        icmpReplyEth.setDestinationMACAddress(icmpRequest.getSourceMACAddress());
+        icmpReplyEth.setSourceMACAddress(icmpRequest.getDestinationMACAddress());
+        icmpReplyEth.setVlanID(icmpRequest.getVlanID());
+
+        Ip4Address destIpAddress = Ip4Address.valueOf(icmpReplyIpv4.getDestinationAddress());
+        Ip4Address destRouterAddress = config.getRouterIpAddressForASubnetHost(destIpAddress);
+        int sid = config.getSegmentId(destRouterAddress);
+        if (sid < 0) {
+            log.warn("Cannot find the Segment ID for {}", destAddress);
+            return;
+        }
+
+        sendPacketOut(outport, icmpReplyEth, sid);
+
+    }
+
+    private void sendPacketOut(ConnectPoint outport, Ethernet payload, int sid) {
+
+        IPv4 ipPacket = (IPv4) payload.getPayload();
+        Ip4Address destIpAddress = Ip4Address.valueOf(ipPacket.getDestinationAddress());
+
+        if (sid == -1 || config.getSegmentId(payload.getDestinationMAC()) == sid ||
+                config.inSameSubnet(outport.deviceId(), destIpAddress)) {
+            TrafficTreatment treatment = DefaultTrafficTreatment.builder().
+                    setOutput(outport.port()).build();
+            OutboundPacket packet = new DefaultOutboundPacket(outport.deviceId(),
+                    treatment, ByteBuffer.wrap(payload.serialize()));
+            srManager.packetService.emit(packet);
+        } else {
+            log.warn("Send a MPLS packet as a ICMP response");
+            TrafficTreatment treatment = DefaultTrafficTreatment.builder()
+                    .setOutput(outport.port())
+                    .build();
+
+            payload.setEtherType(Ethernet.MPLS_UNICAST);
+            MPLS mplsPkt = new MPLS();
+            mplsPkt.setLabel(sid);
+            mplsPkt.setTtl(((IPv4) payload.getPayload()).getTtl());
+            mplsPkt.setPayload(payload.getPayload());
+            payload.setPayload(mplsPkt);
+
+            OutboundPacket packet = new DefaultOutboundPacket(outport.deviceId(),
+                    treatment, ByteBuffer.wrap(payload.serialize()));
+
+            srManager.packetService.emit(packet);
+        }
+    }
+
+
+}