Programming Languages Research Group: Git - pingpong.git/blob

   1 package edu.uci.iotproject.analysis;
   2
   3 import org.pcap4j.core.*;
   4
   5 import java.time.Instant;
   6 import java.util.Collections;
   7 import java.util.List;
   8 import java.util.concurrent.TimeoutException;
   9
  10 /**
  11  * TODO add class documentation.
  12  *
  13  * @author Janus Varmarken
  14  */
  15 public class TriggerTrafficExtractor implements PcapPacketFilter {
  16
  17     private final String mPcapFilePath;
  18     private final List<Instant> mTriggerTimes;
  19     private final String mDeviceIp;
  20
  21     private int mTriggerIndex = 0;
  22
  23
  24     private static final int INCLUSION_WINDOW_MILLIS = 3_000;
  25
  26     public TriggerTrafficExtractor(String pcapFilePath, List<Instant> triggerTimes, String deviceIp) throws PcapNativeException, NotOpenException {
  27         mPcapFilePath = pcapFilePath;
  28         // Ensure that trigger times are sorted in ascending as we rely on this fact in the logic that works out if a
  29         // packet is related to a trigger.
  30         Collections.sort(triggerTimes, (i1, i2) -> {
  31             if (i1.isBefore(i2)) return -1;
  32             else if (i2.isBefore(i1)) return 1;
  33             else return 0;
  34         });
  35         mTriggerTimes = Collections.unmodifiableList(triggerTimes);
  36         mDeviceIp = deviceIp;
  37     }
  38
  39
  40     public void performExtraction(PacketListener... extractedPacketsConsumers) throws PcapNativeException, NotOpenException, TimeoutException {
  41         PcapHandle handle;
  42         try {
  43             handle = Pcaps.openOffline(mPcapFilePath, PcapHandle.TimestampPrecision.NANO);
  44         } catch (PcapNativeException pne) {
  45             handle = Pcaps.openOffline(mPcapFilePath);
  46         }
  47         // Use the native support for BPF to immediately filter irrelevant traffic.
  48         handle.setFilter("ip host " + mDeviceIp, BpfProgram.BpfCompileMode.OPTIMIZE);
  49         PcapHandleReader pcapReader = new PcapHandleReader(handle, this, extractedPacketsConsumers);
  50         pcapReader.readFromHandle();
  51         // Reset trigger index (in case client code chooses to rerun the extraction)
  52         mTriggerIndex = 0;
  53     }
  54
  55 //    public TriggerTrafficExtractor(String deviceIp, PcapHandle handle, List<Instant> triggerTimes) throws PcapNativeException, NotOpenException {
  56 //        mDeviceIp = deviceIp;
  57 //        mHandle = handle;
  58 //        mHandle.setFilter("ip host " + deviceIp, BpfProgram.BpfCompileMode.OPTIMIZE);
  59 //        // Sort in ascending order.
  60 //        Collections.sort(triggerTimes, (i1, i2) -> {
  61 //            if (i1.isBefore(i2)) return -1;
  62 //            else if (i2.isBefore(i1)) return 1;
  63 //            else return 0;
  64 //        });
  65 //        mTriggerTimes = Collections.unmodifiableList(triggerTimes);
  66 //    }
  67
  68
  69
  70     //    private void process() {
  71 //        try {
  72 //            PcapPacket prevPacket = null;
  73 //            PcapPacket packet;
  74 //            while ((packet = mHandle.getNextPacketEx()) != null) {
  75 //                if (prevPacket != null && packet.getTimestamp().isBefore(prevPacket.getTimestamp())) {
  76 //                    // Fail early if assumption doesn't hold.
  77 //                    throw new RuntimeException("Packets not in ascending temporal order");
  78 //                }
  79 //                if (shouldIncludePacket(packet)) {
  80 //                    // TODO output packet
  81 //                }
  82 //                prevPacket = packet;
  83 //            }
  84 //        } catch (PcapNativeException | TimeoutException | NotOpenException e) {
  85 //            e.printStackTrace();
  86 //        } catch (EOFException e) {
  87 //            System.out.println("Reached end of pcap file");
  88 //        }
  89 //    }
  90
  91     @Override
  92     public boolean shouldIncludePacket(PcapPacket packet) {
  93         // TODO hmm, is this correct?
  94         Instant trigger = mTriggerTimes.get(mTriggerIndex);
  95         if (trigger.isBefore(packet.getTimestamp()) &&
  96                 packet.getTimestamp().isBefore(trigger.plusMillis(INCLUSION_WINDOW_MILLIS))) {
  97             // Packet lies within INCLUSION_WINDOW_MILLIS after currently considered trigger, include it.
  98             return true;
  99         } else {
 100             if (!trigger.isBefore(packet.getTimestamp())) {
 101                 // Packet is before currently considered trigger, so it shouldn't be included
 102                 return false;
 103             } else {
 104                 // Packet is >= INCLUSION_WINDOW_MILLIS after currently considered trigger.
 105                 // Proceed to next trigger to see if it lies in range of that.
 106                 // Note that there's an assumption here that no two trigger intervals don't overlap!
 107                 mTriggerIndex++;
 108                 return shouldIncludePacket(packet);
 109             }
 110         }
 111
 112
 113
 114
 115
 116
 117         /*
 118         if (mTriggerIndex >= mTriggerTimes.size()) {
 119             // Don't include packet if we've exhausted the list of trigger timestamps.
 120             return false;
 121         }
 122         Instant trigger = mTriggerTimes.get(mTriggerIndex);
 123         if (trigger.isBefore(packet.getTimestamp()) &&
 124                 packet.getTimestamp().isBefore(trigger.plusMillis(INCLUSION_WINDOW_MILLIS))) {
 125             // Packet lies within INCLUSION_WINDOW_MILLIS after currently considered trigger, include it.
 126             return true;
 127         }
 128         if (mTriggerIndex >= mTriggerTimes.size()-1) {
 129             // No additional triggers left to be considered.
 130             return false;
 131         }
 132         trigger = mTriggerTimes.get(mTriggerIndex + 1);
 133         if (packet.getTimestamp().isBefore(trigger)) {
 134             return false;
 135         } else {
 136             mTriggerIndex++;
 137             return includePacket(packet);
 138         }
 139         */
 140
 141
 142 //        else if (trigger.isBefore(packet.getTimestamp()) &&
 143 //                !packet.getTimestamp().isBefore(trigger.plusMillis(INCLUSION_WINDOW_MILLIS)) {
 144 //
 145 //        }
 146     }
 147
 148
 149     private Instant findTriggerTime(PcapPacket packet) {
 150         mTriggerTimes.stream().filter(i ->
 151                 i.isBefore(packet.getTimestamp()) && packet.getTimestamp().isBefore(i.plusMillis(3000)));
 152
 153         while (mTriggerIndex < mTriggerTimes.size() &&
 154                 !(mTriggerTimes.get(mTriggerIndex).isBefore(packet.getTimestamp()) &&
 155                         packet.getTimestamp().isBefore(mTriggerTimes.get(mTriggerIndex).plusMillis(3_000)))
 156                 ) {
 157             mTriggerIndex++;
 158         }
 159         return mTriggerIndex < mTriggerTimes.size() ? mTriggerTimes.get(mTriggerIndex) : null;
 160         /*
 161         // Trigger time must logically be BEFORE packet timestamp, so advance
 162         while (mTriggerIndex < mTriggerTimes.size() &&
 163                 mTriggerTimes.get(mTriggerIndex).isAfter(packet.getTimestamp())) {
 164             mTriggerIndex++;
 165         }
 166         return mTriggerIndex < mTriggerTimes.size() ? mTriggerTimes.get(mTriggerIndex) : null;
 167         */
 168     }
 169 }