create ARP reply (OpenFlow version 1.3 )

[armandom]

Hi

I'm trying to create an ARP reply for OpenFlow 1.3 based on

http://h30499.www3.hp.com/t5/SDN-Development/replying-ARP-message/m-p/6404080#M199

but does not work

my code is

//------------------------------

cs.addPacketListener(pl2, DIRECTOR, ALTITUDE2, EnumSet.of(ARP));

//----------------------------------------------

privateclass PacketListener2 extends SequencedPacketAdapter {

@Override

publicboolean event(MessageContext context) {

Arp arpPkt = context.decodedPacket().get(ARP);

if (arpPkt.opCode().equals(OpCode.REQ)) {

if (is_a_rule(arpPkt.senderIpAddr(), arpPkt.senderMacAddr(), arpPkt.targetIpAddr(), context.getPacketIn()

.getInPort(), context.srcEvent().dpid())) {

return

true;

}

}

returnfalse;

}

privateboolean is_a_rule(IpAddress senderIpAddr,

MacAddress senderMacAddr, IpAddress targetIpAddr,

BigPortNumber inPort, DataPathId dpid) {

.

.

.

.

Arp arpgen = build_arp(key);

OfmMutablePacketOut packetout = (OfmMutablePacketOut) MessageFactory.create(ProtocolVersion.V_1_3, MessageType.PACKET_OUT);

packetout.inPort(inPort);

packetout.bufferId(BufferId.NO_BUFFER);

packetout.data(arpgen.toString().getBytes());

//packetout.addAction(act)  no ofv1.3

try {

cs.send(packetout.toImmutable(), dpid);

log.info("arp packet was sent"

+ dpid.toString() + "de "

+ arpgen.targetIpAddr().toString());

} catch (OpenflowException e) {

// TODO Auto-generated catch block

e.printStackTrace();

returntrue;

}

the code does not generate any errors and on the log info appears "" arp packet was sent "" ,

thanks for your help

[sepbot]

---

@armandom wrote:

packetout.data(arpgen.toString().getBytes());

---

The above line is calling the getBytes() method from the String class[1], which doesn't structure the packet in the format
specified by the protocol[2], so I guess the packet goes out but since the contents are not understood by other devices they discard them.

[1] http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#getBytes%28%29

[2] http://en.wikipedia.org/wiki/Address_Resolution_Protocol#Packet_structure

[armandom]

sepbot thank you for your help  

I made the changes you recommended me but did not work

another idea?

thanks

[RichieKotzen]

Hi guys,

Here is an ArpPacket class which I've created an ARP packet and how to create a PACKET_OUT message:

***** ARPPacket ******

package example;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;

public class ArpPacket {
private static final int ARP_RESPONSE = 2;
private static final int HW_TYPE = 1;// ethernet
private static final int PROTOCOL_TYPE = 0x0800;
private static final int HW_ADDRESS_LENGHT = 6; // mac
private static final int PROTOCOL_ADDRESS_LENGTH = 4; // ipv4

public static byte[] createArpPacket(String srcIp, String srcMac,
String dstIp, String dstMac) {
byte[] sIp = new byte[4];
byte[] sMac = new byte[6];
byte[] dIp = new byte[4];
byte[] dMac = new byte[6];

System.out.println("ArpMessage: srcIp" + srcIp);
for (int i = 0; i < 4; i++) {
sIp[i] = (byte) Integer.parseInt(srcIp.split("\\.")[i]);
}

System.out.println("ArpMessage: srcMac" + srcMac);
for (int i = 0; i < 6; i++) {
sMac[i] = (byte) Integer.parseInt(srcMac.split(":")[i], 16);
}

System.out.println("ArpMessage: dstIp" + dstIp);
for (int i = 0; i < 4; i++) {
dIp[i] = (byte) Integer.parseInt(dstIp.split("\\.")[i]);
}

System.out.println("ArpMessage: dstMac" + dstMac);
for (int i = 0; i < 6; i++) {
dMac[i] = (byte) Integer.parseInt(dstMac.split(":")[i], 16);
}

//TODO: calculate exact packet length
ByteBuffer buf = ByteBuffer.allocate(28+14);
buf.clear();
buf.order(ByteOrder.BIG_ENDIAN);

buf.put(dMac);
buf.put(sMac);
buf.putShort((short) 0x0806);
buf.putShort((short) HW_TYPE);
buf.putShort((short) PROTOCOL_TYPE);
buf.put((byte) HW_ADDRESS_LENGHT);
buf.put((byte) PROTOCOL_ADDRESS_LENGTH);
buf.putShort((short) ARP_RESPONSE);
buf.put(sMac);
buf.put(sIp);
buf.put(dMac);
buf.put(dIp);

return buf.array();
}
}

******** PACKET_OUT***********

OfmMutablePacketOut pOut = (OfmMutablePacketOut) MessageFactory.create(PV, MessageType.PACKET_OUT);

byte[] arpResponse = ArpPacket.createArpPacket(IP_SERVER_VIRTUAL, MAC_SERVER_VIRTUAL,senderIp.toString(), senderMac.toString());

System.out.println("SENDING TO SWITCH PORT: ["
+ senderIp.toString() + ":"
+ s.getPortToHost(senderIp.toString()) + "]");
System.out.println("#################################");

pOut.bufferId(BUFFER_ID)
.inPort(Port.CONTROLLER)
.data(arpResponse)
.addAction(
ActionFactory.createAction(PV,
ActionType.OUTPUT, messageContext
.getPacketIn().getInPort()));

[armandom]

HI   RichieKotzen

I tested your code in my application but it did not work

Can you use this code for OpenFlow version 1.3?

 because according to the api. addAction  is not used since 1.1

thank you

[sdnindia]

Hello armandom,

We are looking into the issue and we will come back.

Thanks,
HP SDN Team

[sdnindia]

Hello armandom,

Please find the attached file DeviceHealthManager.java for sample ARP-Proxy App to send Arp-Reply.

Currently ‘PROXY_MAC_ADDRESS’ and ‘ALTITUDE’ of the App are hardcoded.

SDN Controller used :  2.2.5.0016

SDN SDK used  : 2.2.5

Hybrid mode of the controller : false

Please let us know if you still face the problem.

Thanks,

HP SDN Team