Code/Projects/SmartPlugDetector/src/main/java/edu/uci/iotproject/trafficreassembly/layer2/Layer2Flow.java

   1 package edu.uci.iotproject.trafficreassembly.layer2;
   2
   3 import edu.uci.iotproject.detection.Layer2FlowObserver;
   4 import org.pcap4j.core.PcapPacket;
   5 import org.pcap4j.packet.EthernetPacket;
   6 import org.pcap4j.util.MacAddress;
   7
   8 import java.util.ArrayList;
   9 import java.util.Collections;
  10 import java.util.List;
  11
  12 /**
  13  * The packets exchanged between two endpoints (MAC addresses).
  14  *
  15  * @author Janus Varmarken
  16  */
  17 public class Layer2Flow {
  18
  19     private final MacAddress mEndpoint1;
  20     private final MacAddress mEndpoint2;
  21
  22     private final List<Layer2FlowObserver> mFlowObservers = new ArrayList<>();
  23
  24     public Layer2Flow(MacAddress endpoint1, MacAddress endpoint2) {
  25         mEndpoint1 = endpoint1;
  26         mEndpoint2 = endpoint2;
  27     }
  28
  29     public void addFlowObserver(Layer2FlowObserver observer) {
  30         mFlowObservers.add(observer);
  31     }
  32
  33     public void removeFlowObserver(Layer2FlowObserver observer) {
  34         mFlowObservers.remove(observer);
  35     }
  36
  37     /**
  38      * The packets in the flow.
  39      */
  40     private final List<PcapPacket> mPackets = new ArrayList<>();
  41
  42     /**
  43      * Add a packet to this flow.
  44      * @param packet The packet that is to be added to the flow.
  45      */
  46     public void addPacket(PcapPacket packet) {
  47         verifyAddresses(packet);
  48         mPackets.add(packet);
  49         // Notify flow observers of the new packet
  50         mFlowObservers.forEach(o -> o.onNewPacket(this, packet));
  51     }
  52
  53     public List<PcapPacket> getPackets() {
  54         return Collections.unmodifiableList(mPackets);
  55     }
  56
  57     private void verifyAddresses(PcapPacket packet) {
  58         EthernetPacket ethPkt = packet.get(EthernetPacket.class);
  59         MacAddress srcAddr = ethPkt.getHeader().getSrcAddr();
  60         MacAddress dstAddr = ethPkt.getHeader().getDstAddr();
  61         if ((mEndpoint1.equals(srcAddr) && mEndpoint2.equals(dstAddr)) ||
  62                 (mEndpoint1.equals(dstAddr) && mEndpoint2.equals(srcAddr))) {
  63             // All is good.
  64             return;
  65         }
  66         throw new IllegalArgumentException("Mismatch in MACs: packet does not pertain to this flow");
  67     }
  68
  69 }
  70
  71
  72
  73 /*
  74
  75
  76  Packet stream -> flow reassembler -> flow1, flow2, flow3... -> for each flow, keep a sequence matcher for each sequence of cluster
  77
  78
  79  */