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/*
* 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.onosproject.segmentrouting.config.DeviceConfigNotFoundException;
import org.onosproject.segmentrouting.config.DeviceConfiguration;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.nio.ByteBuffer;
import java.util.Set;
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());
Set<Ip4Address> gatewayIpAddresses = config.getPortIPs(deviceId);
Ip4Address routerIp;
try {
routerIp = config.getRouterIp(deviceId);
} catch (DeviceConfigNotFoundException e) {
log.warn(e.getMessage() + " Aborting processPacketIn.");
return;
}
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);
// ICMP for any known host
} else if (!srManager.hostService.getHostsByIp(destinationAddress).isEmpty()) {
// TODO: known host packet should not be coming to controller - resend flows?
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
}
}
/**
* Sends an ICMP reply message.
*
* Note: we assume that packets sending from the edge switches to the hosts
* have untagged VLAN.
* @param icmpRequest the original ICMP request
* @param outport the output port where the ICMP reply should be sent to
*/
private void sendICMPResponse(Ethernet icmpRequest, ConnectPoint outport) {
// Note: We assume that packets arrive at the edge switches have
// untagged VLAN.
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.setPayload(((ICMP) icmpRequestIpv4.getPayload()).getPayload());
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());
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);
}
}
}
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