Code/Projects/SmartPlugDetector/src/main/java/edu/uci/iotproject/comparison/ComparisonFunctions.java

   1 package edu.uci.iotproject.comparison;
   2
   3 import edu.uci.iotproject.Conversation;
   4 import edu.uci.iotproject.FlowPattern;
   5 import org.pcap4j.core.PcapPacket;
   6 import org.pcap4j.packet.TcpPacket;
   7
   8 import java.util.List;
   9 import java.util.function.BiFunction;
  10
  11 /**
  12  * Contains concrete implementations of comparison functions that compare a {@link Conversation} and a {@link FlowPattern}.
  13  * These functions are supplied to {@link PatternComparisonTask} which in turn facilitates comparison on a background thread.
  14  * This design provides plugability: currently, we only support complete match comparison, but further down the road we
  15  * can simply introduce more sophisticated comparison functions here (e.g. Least Common Substring) simply replace the
  16  * argument passed to the {@link PatternComparisonTask} constructor to switch between the different implementations.
  17  *
  18  * @author Janus Varmarken {@literal <jvarmark@uci.edu>}
  19  * @author Rahmadi Trimananda {@literal <rtrimana@uci.edu>}
  20  */
  21 public class ComparisonFunctions {
  22
  23     /**
  24      * Comparison function that checks for a <em>complete</em> match, i.e. a match in which every packet in the
  25      * {@link Conversation} has the same length as the corresponding packet in the {@link FlowPattern}.
  26      */
  27     public static final BiFunction<Conversation, FlowPattern, CompleteMatchPatternComparisonResult> COMPLETE_MATCH = (conversation, flowPattern) -> {
  28         List<PcapPacket> convPackets = conversation.getPackets();
  29         if (convPackets.size() != flowPattern.getLength()) {
  30             return new CompleteMatchPatternComparisonResult(conversation, flowPattern, false);
  31         }
  32         for (int i = 0; i < convPackets.size(); i++) {
  33             TcpPacket tcpPacket = convPackets.get(i).get(TcpPacket.class);
  34             if (tcpPacket.getPayload().length() != flowPattern.getPacketOrder().get(i)) {
  35                 return new CompleteMatchPatternComparisonResult(conversation, flowPattern, false);
  36             }
  37         }
  38         return new CompleteMatchPatternComparisonResult(conversation, flowPattern, true);
  39     };
  40
  41 }