--- /dev/null
+package edu.uci.iotproject.detection.layer3;
+
+import edu.uci.iotproject.detection.AbstractClusterMatcher;
+import edu.uci.iotproject.detection.ClusterMatcherObserver;
+import edu.uci.iotproject.trafficreassembly.layer3.Conversation;
+import edu.uci.iotproject.trafficreassembly.layer3.TcpReassembler;
+import edu.uci.iotproject.analysis.TcpConversationUtils;
+import edu.uci.iotproject.io.PcapHandleReader;
+import edu.uci.iotproject.util.PrintUtils;
+import org.pcap4j.core.*;
+
+import java.time.ZoneId;
+import java.util.*;
+import java.util.stream.Collectors;
+
+import static edu.uci.iotproject.util.PcapPacketUtils.*;
+
+/**
+ * Searches a traffic trace for sequences of packets "belong to" a given cluster (in other words, attempts to classify
+ * traffic as pertaining to a given cluster).
+ *
+ * @author Janus Varmarken {@literal <jvarmark@uci.edu>}
+ * @author Rahmadi Trimananda {@literal <rtrimana@uci.edu>}
+ */
+public class Layer3ClusterMatcher extends AbstractClusterMatcher implements PacketListener {
+
+ // Test client
+ public static void main(String[] args) throws PcapNativeException, NotOpenException {
+
+// String path = "/scratch/July-2018"; // Rahmadi
+ String path = "/Users/varmarken/temp/UCI IoT Project/experiments"; // Janus
+ final String inputPcapFile = path + "/2018-07/dlink/dlink.wlan1.local.pcap";
+ final String signatureFile = path + "/2018-07/dlink/offSignature1.sig";
+
+ List<List<PcapPacket>> signature = PrintUtils.deserializeClustersFromFile(signatureFile);
+ Layer3ClusterMatcher clusterMatcher = new Layer3ClusterMatcher(signature, null,
+ (sig, match) -> System.out.println(
+ String.format("[ !!! SIGNATURE DETECTED AT %s !!! ]",
+ match.get(0).getTimestamp().atZone(ZoneId.of("America/Los_Angeles")))
+ )
+ );
+
+ PcapHandle handle;
+ try {
+ handle = Pcaps.openOffline(inputPcapFile, PcapHandle.TimestampPrecision.NANO);
+ } catch (PcapNativeException pne) {
+ handle = Pcaps.openOffline(inputPcapFile);
+ }
+ PcapHandleReader reader = new PcapHandleReader(handle, p -> true, clusterMatcher);
+ reader.readFromHandle();
+ clusterMatcher.performDetection();
+ }
+
+ /**
+ * The ordered directions of packets in the sequences that make up {@link #mCluster}.
+ */
+ private final Conversation.Direction[] mClusterMemberDirections;
+
+ /**
+ * For reassembling the observed traffic into TCP connections.
+ */
+ private final TcpReassembler mTcpReassembler = new TcpReassembler();
+
+ /**
+ * IP of the router's WAN port (if analyzed traffic is captured at the ISP's point of view).
+ */
+ private final String mRouterWanIp;
+
+ /**
+ * Create a {@link Layer3ClusterMatcher}.
+ * @param cluster The cluster that traffic is matched against.
+ * @param routerWanIp The router's WAN IP if examining traffic captured at the ISP's point of view (used for
+ * determining the direction of packets).
+ * @param detectionObservers Client code that wants to get notified whenever the {@link Layer3ClusterMatcher} detects that
+ * (a subset of) the examined traffic is similar to the traffic that makes up
+ * {@code cluster}, i.e., when the examined traffic is classified as pertaining to
+ * {@code cluster}.
+ */
+ public Layer3ClusterMatcher(List<List<PcapPacket>> cluster, String routerWanIp,
+ ClusterMatcherObserver... detectionObservers) {
+ super(cluster);
+ Objects.requireNonNull(detectionObservers, "detectionObservers cannot be null");
+ for (ClusterMatcherObserver obs : detectionObservers) {
+ addObserver(obs);
+ }
+ // Build the cluster members' direction sequence.
+ // Note: assumes that the provided cluster was captured within the local network (routerWanIp is set to null).
+ mClusterMemberDirections = getPacketDirections(cluster.get(0), null);
+ /*
+ * Enforce restriction on cluster members: all representatives must exhibit the same direction pattern and
+ * contain the same number of packets. Note that this is a somewhat heavy operation, so it may be disabled later
+ * on in favor of performance. However, it is only run once (at instantiation), so the overhead may be warranted
+ * in order to ensure correctness, especially during the development/debugging phase.
+ */
+ if (mCluster.stream().
+ anyMatch(inner -> !Arrays.equals(mClusterMemberDirections, getPacketDirections(inner, null)))) {
+ throw new IllegalArgumentException(
+ "cluster members must contain the same number of packets and exhibit the same packet direction " +
+ "pattern"
+ );
+ }
+ mRouterWanIp = routerWanIp;
+ }
+
+ @Override
+ public void gotPacket(PcapPacket packet) {
+ // Present packet to TCP reassembler so that it can be mapped to a connection (if it is a TCP packet).
+ mTcpReassembler.gotPacket(packet);
+ }
+
+ /**
+ * Get the cluster that describes the packet sequence that this {@link Layer3ClusterMatcher} is searching for.
+ * @return the cluster that describes the packet sequence that this {@link Layer3ClusterMatcher} is searching for.
+ */
+ public List<List<PcapPacket>> getCluster() {
+ return mCluster;
+ }
+
+ public void performDetection() {
+ /*
+ * Let's start out simple by building a version that only works for signatures that do not span across multiple
+ * TCP conversations...
+ */
+ for (Conversation c : mTcpReassembler.getTcpConversations()) {
+ if (c.isTls() && c.getTlsApplicationDataPackets().isEmpty() || !c.isTls() && c.getPackets().isEmpty()) {
+ // Skip empty conversations.
+ continue;
+ }
+ for (List<PcapPacket> signatureSequence : mCluster) {
+ if (isTlsSequence(signatureSequence) != c.isTls()) {
+ // We consider it a mismatch if one is a TLS application data sequence and the other is not.
+ continue;
+ }
+ // Fetch set of packets to examine based on TLS or not.
+ List<PcapPacket> cPkts = c.isTls() ? c.getTlsApplicationDataPackets() : c.getPackets();
+ /*
+ * Note: we embed the attempt to detect the signature sequence in a loop in order to capture those cases
+ * where the same signature sequence appears multiple times in one Conversation.
+ *
+ * Note: since we expect all sequences that together make up the signature to exhibit the same direction
+ * pattern, we can simply pass the precomputed direction array for the signature sequence so that it
+ * won't have to be recomputed internally in each call to findSubsequenceInSequence().
+ */
+ Optional<List<PcapPacket>> match;
+ while ((match = findSubsequenceInSequence(signatureSequence, cPkts, mClusterMemberDirections, null)).
+ isPresent()) {
+ List<PcapPacket> matchSeq = match.get();
+ // Notify observers about the match.
+ mObservers.forEach(o -> o.onMatch(Layer3ClusterMatcher.this, matchSeq));
+ /*
+ * Get the index in cPkts of the last packet in the sequence of packets that matches the searched
+ * signature sequence.
+ */
+ int matchSeqEndIdx = cPkts.indexOf(matchSeq.get(matchSeq.size()-1));
+ // We restart the search for the signature sequence immediately after that index, so truncate cPkts.
+ cPkts = cPkts.stream().skip(matchSeqEndIdx + 1).collect(Collectors.toList());
+ }
+ }
+ /*
+ * TODO:
+ * if no item in cluster matches, also perform a distance-based matching to cover those cases where we did
+ * not manage to capture every single mutation of the sequence during training.
+ *
+ * Need to compute average/centroid of cluster to do so...? Compute within-cluster variance, then check if
+ * distance between input conversation and cluster average/centroid is smaller than or equal to the computed
+ * variance?
+ */
+ }
+ }
+
+ /**
+ * Checks if {@code sequence} is a sequence of TLS packets. Note: the current implementation relies on inspection
+ * of the port numbers when deciding between TLS vs. non-TLS. Therefore, only the first packet of {@code sequence}
+ * is examined as it is assumed that all packets in {@code sequence} pertain to the same {@link Conversation} and
+ * hence share the same set of two src/dst port numbers (albeit possibly alternating between which one is the src
+ * and which one is the dst, as packets in {@code sequence} may be in alternating directions).
+ * @param sequence The sequence of packets for which it is to be determined if it is a sequence of TLS packets or
+ * non-TLS packets.
+ * @return {@code true} if {@code sequence} is a sequence of TLS packets, {@code false} otherwise.
+ */
+ private boolean isTlsSequence(List<PcapPacket> sequence) {
+ // NOTE: Assumes ALL packets in sequence pertain to the same TCP connection!
+ PcapPacket firstPkt = sequence.get(0);
+ int srcPort = getSourcePort(firstPkt);
+ int dstPort = getDestinationPort(firstPkt);
+ return TcpConversationUtils.isTlsPort(srcPort) || TcpConversationUtils.isTlsPort(dstPort);
+ }
+
+ /**
+ * Examine if a given sequence of packets ({@code sequence}) contains a given shorter sequence of packets
+ * ({@code subsequence}). Note: the current implementation actually searches for a substring as it does not allow
+ * for interleaving packets in {@code sequence} that are not in {@code subsequence}; for example, if
+ * {@code subsequence} consists of packet lengths [2, 3, 5] and {@code sequence} consists of packet lengths
+ * [2, 3, 4, 5], the result will be that there is no match (because of the interleaving 4). If we are to allow
+ * interleaving packets, we need a modified version of
+ * <a href="https://stackoverflow.com/a/20545604/1214974">this</a>.
+ *
+ * @param subsequence The sequence to search for.
+ * @param sequence The sequence to search.
+ * @param subsequenceDirections The directions of packets in {@code subsequence} such that for all {@code i},
+ * {@code subsequenceDirections[i]} is the direction of the packet returned by
+ * {@code subsequence.get(i)}. May be set to {@code null}, in which this call will
+ * internally compute the packet directions.
+ * @param sequenceDirections The directions of packets in {@code sequence} such that for all {@code i},
+ * {@code sequenceDirections[i]} is the direction of the packet returned by
+ * {@code sequence.get(i)}. May be set to {@code null}, in which this call will internally
+ * compute the packet directions.
+ *
+ * @return An {@link Optional} containing the part of {@code sequence} that matches {@code subsequence}, or an empty
+ * {@link Optional} if no part of {@code sequence} matches {@code subsequence}.
+ */
+ private Optional<List<PcapPacket>> findSubsequenceInSequence(List<PcapPacket> subsequence,
+ List<PcapPacket> sequence,
+ Conversation.Direction[] subsequenceDirections,
+ Conversation.Direction[] sequenceDirections) {
+ if (sequence.size() < subsequence.size()) {
+ // If subsequence is longer, it cannot be contained in sequence.
+ return Optional.empty();
+ }
+ if (isTlsSequence(subsequence) != isTlsSequence(sequence)) {
+ // We consider it a mismatch if one is a TLS application data sequence and the other is not.
+ return Optional.empty();
+ }
+ // If packet directions have not been precomputed by calling code, we need to construct them.
+ if (subsequenceDirections == null) {
+ subsequenceDirections = getPacketDirections(subsequence, mRouterWanIp);
+ }
+ if (sequenceDirections == null) {
+ sequenceDirections = getPacketDirections(sequence, mRouterWanIp);
+ }
+ int subseqIdx = 0;
+ int seqIdx = 0;
+ while (seqIdx < sequence.size()) {
+ PcapPacket subseqPkt = subsequence.get(subseqIdx);
+ PcapPacket seqPkt = sequence.get(seqIdx);
+ // We only have a match if packet lengths and directions match.
+ if (subseqPkt.getOriginalLength() == seqPkt.getOriginalLength() &&
+ subsequenceDirections[subseqIdx] == sequenceDirections[seqIdx]) {
+ // A match; advance both indices to consider next packet in subsequence vs. next packet in sequence.
+ subseqIdx++;
+ seqIdx++;
+ if (subseqIdx == subsequence.size()) {
+ // We managed to match the entire subsequence in sequence.
+ // Return the sublist of sequence that matches subsequence.
+ /*
+ * TODO:
+ * ASSUMES THE BACKING LIST (i.e., 'sequence') IS _NOT_ STRUCTURALLY MODIFIED, hence may not work
+ * for live traces!
+ */
+ return Optional.of(sequence.subList(seqIdx - subsequence.size(), seqIdx));
+ }
+ } else {
+ // Mismatch.
+ if (subseqIdx > 0) {
+ /*
+ * If we managed to match parts of subsequence, we restart the search for subsequence in sequence at
+ * the index of sequence where the current mismatch occurred. I.e., we must reset subseqIdx, but
+ * leave seqIdx untouched.
+ */
+ subseqIdx = 0;
+ } else {
+ /*
+ * First packet of subsequence didn't match packet at seqIdx of sequence, so we move forward in
+ * sequence, i.e., we continue the search for subsequence in sequence starting at index seqIdx+1 of
+ * sequence.
+ */
+ seqIdx++;
+ }
+ }
+ }
+ return Optional.empty();
+ }
+
+ /**
+ * Given a cluster, produces a pruned version of that cluster. In the pruned version, there are no duplicate cluster
+ * members. Two cluster members are considered identical if their packets lengths and packet directions are
+ * identical. The resulting pruned cluster is unmodifiable (this applies to both the outermost list as well as the
+ * nested lists) in order to preserve its integrity when exposed to external code (e.g., through
+ * {@link #getCluster()}).
+ *
+ * @param cluster A cluster to prune.
+ * @return The resulting pruned cluster.
+ */
+ @Override
+ protected List<List<PcapPacket>> pruneCluster(List<List<PcapPacket>> cluster) {
+ List<List<PcapPacket>> prunedCluster = new ArrayList<>();
+ for (List<PcapPacket> originalClusterSeq : cluster) {
+ boolean alreadyPresent = false;
+ for (List<PcapPacket> prunedClusterSeq : prunedCluster) {
+ Optional<List<PcapPacket>> duplicate = findSubsequenceInSequence(originalClusterSeq, prunedClusterSeq,
+ mClusterMemberDirections, mClusterMemberDirections);
+ if (duplicate.isPresent()) {
+ alreadyPresent = true;
+ break;
+ }
+ }
+ if (!alreadyPresent) {
+ prunedCluster.add(Collections.unmodifiableList(originalClusterSeq));
+ }
+ }
+ return Collections.unmodifiableList(prunedCluster);
+ }
+
+ /**
+ * Given a {@code List<PcapPacket>}, generate a {@code Conversation.Direction[]} such that each entry in the
+ * resulting {@code Conversation.Direction[]} specifies the direction of the {@link PcapPacket} at the corresponding
+ * index in the input list.
+ * @param packets The list of packets for which to construct a corresponding array of packet directions.
+ * @param routerWanIp The IP of the router's WAN port. This is used for determining the direction of packets when
+ * the traffic is captured just outside the local network (at the ISP side of the router). Set to
+ * {@code null} if {@code packets} stem from traffic captured within the local network.
+ * @return A {@code Conversation.Direction[]} specifying the direction of the {@link PcapPacket} at the
+ * corresponding index in {@code packets}.
+ */
+ private static Conversation.Direction[] getPacketDirections(List<PcapPacket> packets, String routerWanIp) {
+ Conversation.Direction[] directions = new Conversation.Direction[packets.size()];
+ for (int i = 0; i < packets.size(); i++) {
+ PcapPacket pkt = packets.get(i);
+ if (getSourceIp(pkt).equals(getDestinationIp(pkt))) {
+ // Sanity check: we shouldn't be processing loopback traffic
+ throw new AssertionError("loopback traffic detected");
+ }
+ if (isSrcIpLocal(pkt) || getSourceIp(pkt).equals(routerWanIp)) {
+ directions[i] = Conversation.Direction.CLIENT_TO_SERVER;
+ } else if (isDstIpLocal(pkt) || getDestinationIp(pkt).equals(routerWanIp)) {
+ directions[i] = Conversation.Direction.SERVER_TO_CLIENT;
+ } else {
+ //throw new IllegalArgumentException("no local IP or router WAN port IP found, can't detect direction");
+ }
+ }
+ return directions;
+ }
+
+}
projects / pingpong.git / blobdiff