/**
* Sends an ARP or Neighbor Discovery Protocol request for the given IP address.
*
* @param targetIp IP address to send the request for
*/
private void sendArpNdpRequest(IpAddress targetIp) {
Interface intf = interfaceService.getMatchingInterface(targetIp);
if (intf == null) {
return;
}
for (InterfaceIpAddress ia : intf.ipAddresses()) {
if (ia.subnetAddress().contains(targetIp)) {
sendArpNdpProbe(intf.connectPoint(), targetIp, ia.ipAddress(), intf.mac(), intf.vlan());
}
}
}
private void transformAndSend(IPv4 ipv4, Interface egressInterface, MacAddress macAddress) {
Ethernet eth = new Ethernet();
eth.setDestinationMACAddress(macAddress);
eth.setSourceMACAddress(egressInterface.mac());
eth.setEtherType(EthType.EtherType.IPV4.ethType().toShort());
eth.setPayload(ipv4);
if (!egressInterface.vlan().equals(VlanId.NONE)) {
eth.setVlanID(egressInterface.vlan().toShort());
}
ipv4.setTtl((byte) (ipv4.getTtl() - 1));
ipv4.setChecksum((short) 0);
send(eth, egressInterface.connectPoint());
}
private void handle(Ethernet eth) {
checkNotNull(eth);
if (!(eth.getEtherType() == EthType.EtherType.IPV4.ethType().toShort())) {
return;
}
IPv4 ipv4 = (IPv4) eth.getPayload().clone();
Ip4Address dstIp = Ip4Address.valueOf(ipv4.getDestinationAddress());
Interface egressInterface = interfaceService.getMatchingInterface(dstIp);
if (egressInterface == null) {
log.info("No egress interface found for {}", dstIp);
return;
}
Optional<Host> host =
hostService
.getHostsByIp(dstIp)
.stream()
.filter(h -> h.location().equals(egressInterface.connectPoint()))
.filter(h -> h.vlan().equals(egressInterface.vlan()))
.findAny();
if (host.isPresent()) {
transformAndSend(ipv4, egressInterface, host.get().mac());
} else {
hostService.startMonitoringIp(dstIp);
ipPacketCache
.asMap()
.compute(
dstIp,
(ip, queue) -> {
if (queue == null) {
queue = new ConcurrentLinkedQueue();
}
queue.add(ipv4);
return queue;
});
}
}
/**
* Generates a route intent for a prefix, the next hop IP address, and the next hop MAC address.
*
* <p>This method will find the egress interface for the intent. Intent will match dst IP prefix
* and rewrite dst MAC address at all other border switches, then forward packets according to dst
* MAC address.
*
* @param prefix IP prefix of the route to add
* @param nextHopIpAddress IP address of the next hop
* @param nextHopMacAddress MAC address of the next hop
* @return the generated intent, or null if no intent should be submitted
*/
private MultiPointToSinglePointIntent generateRouteIntent(
IpPrefix prefix, IpAddress nextHopIpAddress, MacAddress nextHopMacAddress) {
// Find the attachment point (egress interface) of the next hop
Interface egressInterface = interfaceService.getMatchingInterface(nextHopIpAddress);
if (egressInterface == null) {
log.warn("No outgoing interface found for {}", nextHopIpAddress);
return null;
}
// Generate the intent itself
Set<ConnectPoint> ingressPorts = new HashSet<>();
ConnectPoint egressPort = egressInterface.connectPoint();
log.debug("Generating intent for prefix {}, next hop mac {}", prefix, nextHopMacAddress);
for (Interface intf : interfaceService.getInterfaces()) {
// TODO this should be only peering interfaces
if (!intf.connectPoint().equals(egressInterface.connectPoint())) {
ConnectPoint srcPort = intf.connectPoint();
ingressPorts.add(srcPort);
}
}
// Match the destination IP prefix at the first hop
TrafficSelector.Builder selector = DefaultTrafficSelector.builder();
if (prefix.isIp4()) {
selector.matchEthType(Ethernet.TYPE_IPV4);
// if it is default route, then we do not need match destination
// IP address
if (prefix.prefixLength() != 0) {
selector.matchIPDst(prefix);
}
} else {
selector.matchEthType(Ethernet.TYPE_IPV6);
// if it is default route, then we do not need match destination
// IP address
if (prefix.prefixLength() != 0) {
selector.matchIPv6Dst(prefix);
}
}
// Rewrite the destination MAC address
TrafficTreatment.Builder treatment =
DefaultTrafficTreatment.builder().setEthDst(nextHopMacAddress);
if (!egressInterface.vlan().equals(VlanId.NONE)) {
treatment.setVlanId(egressInterface.vlan());
// If we set VLAN ID, we have to make sure a VLAN tag exists.
// TODO support no VLAN -> VLAN routing
selector.matchVlanId(VlanId.ANY);
}
int priority = prefix.prefixLength() * PRIORITY_MULTIPLIER + PRIORITY_OFFSET;
Key key = Key.of(prefix.toString(), appId);
return MultiPointToSinglePointIntent.builder()
.appId(appId)
.key(key)
.selector(selector.build())
.treatment(treatment.build())
.ingressPoints(ingressPorts)
.egressPoint(egressPort)
.priority(priority)
.constraints(CONSTRAINTS)
.build();
}