1 package edu.uci.iotproject.detection.layer2;
3 import edu.uci.iotproject.analysis.TriggerTrafficExtractor;
4 import edu.uci.iotproject.analysis.UserAction;
5 import edu.uci.iotproject.detection.AbstractClusterMatcher;
6 import edu.uci.iotproject.detection.ClusterMatcherObserver;
7 import edu.uci.iotproject.detection.SignatureDetectorObserver;
8 import edu.uci.iotproject.io.PcapHandleReader;
9 import edu.uci.iotproject.io.PrintWriterUtils;
10 import edu.uci.iotproject.trafficreassembly.layer2.Layer2FlowReassembler;
11 import edu.uci.iotproject.util.PrintUtils;
12 import org.jgrapht.GraphPath;
13 import org.jgrapht.alg.shortestpath.DijkstraShortestPath;
14 import org.jgrapht.graph.DefaultWeightedEdge;
15 import org.jgrapht.graph.SimpleDirectedWeightedGraph;
16 import org.pcap4j.core.*;
19 import java.io.FileWriter;
20 import java.io.IOException;
21 import java.io.PrintWriter;
22 import java.time.Duration;
26 * Performs layer 2 signature detection.
28 * @author Janus Varmarken {@literal <jvarmark@uci.edu>}
29 * @author Rahmadi Trimananda {@literal <rtrimana@uci.edu>}
31 public class Layer2SignatureDetector implements PacketListener, ClusterMatcherObserver {
34 * If set to {@code true}, output written to the results file is also dumped to standard out.
36 private static boolean DUPLICATE_OUTPUT_TO_STD_OUT = true;
38 public static void main(String[] args) throws PcapNativeException, NotOpenException, IOException {
39 if (args.length < 4) {
40 String errMsg = String.format("Usage: %s inputPcapFile onSignatureFile offSignatureFile resultsFile [stdOut]" +
41 "\n - inputPcapFile: the target of the detection" +
42 "\n - onSignatureFile: the file that contains the ON signature to search for" +
43 "\n - offSignatureFile: the file that contains the OFF signature to search for" +
44 "\n - resultsFile: where to write the results of the detection" +
45 "\n - stdOut: optional true/false literal indicating if output should also be printed to std out; default is true",
46 Layer2SignatureDetector.class.getSimpleName());
47 System.out.println(errMsg);
50 final String pcapFile = args[0];
51 final String onSignatureFile = args[1];
52 final String offSignatureFile = args[2];
53 final String resultsFile = args[3];
54 if (args.length == 5) {
55 DUPLICATE_OUTPUT_TO_STD_OUT = Boolean.parseBoolean(args[4]);
58 // Prepare file outputter.
59 File outputFile = new File(resultsFile);
60 outputFile.getParentFile().mkdirs();
61 final PrintWriter resultsWriter = new PrintWriter(new FileWriter(outputFile));
62 // Include metadata as comments at the top
63 PrintWriterUtils.println("# Detection results for:", resultsWriter, DUPLICATE_OUTPUT_TO_STD_OUT);
64 PrintWriterUtils.println("# - inputPcapFile: " + pcapFile, resultsWriter, DUPLICATE_OUTPUT_TO_STD_OUT);
65 PrintWriterUtils.println("# - onSignatureFile: " + onSignatureFile, resultsWriter, DUPLICATE_OUTPUT_TO_STD_OUT);
66 PrintWriterUtils.println("# - offSignatureFile: " + offSignatureFile, resultsWriter, DUPLICATE_OUTPUT_TO_STD_OUT);
67 resultsWriter.flush();
69 // Create signature detectors and add observers that output their detected events.
70 Layer2SignatureDetector onDetector = new Layer2SignatureDetector(PrintUtils.deserializeSignatureFromFile(onSignatureFile));
71 Layer2SignatureDetector offDetector = new Layer2SignatureDetector(PrintUtils.deserializeSignatureFromFile(offSignatureFile));
72 onDetector.addObserver((signature, match) -> {
73 UserAction event = new UserAction(UserAction.Type.TOGGLE_ON, match.get(0).get(0).getTimestamp());
74 PrintWriterUtils.println(event, resultsWriter, DUPLICATE_OUTPUT_TO_STD_OUT);
76 offDetector.addObserver((signature, match) -> {
77 UserAction event = new UserAction(UserAction.Type.TOGGLE_OFF, match.get(0).get(0).getTimestamp());
78 PrintWriterUtils.println(event, resultsWriter, DUPLICATE_OUTPUT_TO_STD_OUT);
84 handle = Pcaps.openOffline(pcapFile, PcapHandle.TimestampPrecision.NANO);
85 } catch (PcapNativeException pne) {
86 handle = Pcaps.openOffline(pcapFile);
88 PcapHandleReader reader = new PcapHandleReader(handle, p -> true, onDetector, offDetector);
90 reader.readFromHandle();
92 // Flush output to results file and close it.
93 resultsWriter.flush();
94 resultsWriter.close();
98 * The signature that this {@link Layer2SignatureDetector} is searching for.
100 private final List<List<List<PcapPacket>>> mSignature;
103 * The {@link Layer2ClusterMatcher}s in charge of detecting each individual sequence of packets that together make
104 * up the the signature.
106 private final List<Layer2ClusterMatcher> mClusterMatchers;
109 * For each {@code i} ({@code i >= 0 && i < mPendingMatches.length}), {@code mPendingMatches[i]} holds the matches
110 * found by the {@link Layer2ClusterMatcher} at {@code mClusterMatchers.get(i)} that have yet to be "consumed",
111 * i.e., have yet to be included in a signature detected by this {@link Layer2SignatureDetector} (a signature can
112 * be encompassed of multiple packet sequences occurring shortly after one another on multiple connections).
114 private final List<List<PcapPacket>>[] mPendingMatches;
117 * Maps a {@link Layer2ClusterMatcher} to its corresponding index in {@link #mPendingMatches}.
119 private final Map<Layer2ClusterMatcher, Integer> mClusterMatcherIds;
122 * In charge of reassembling layer 2 packet flows.
124 private final Layer2FlowReassembler mFlowReassembler = new Layer2FlowReassembler();
126 private final List<SignatureDetectorObserver> mObservers = new ArrayList<>();
128 public Layer2SignatureDetector(List<List<List<PcapPacket>>> searchedSignature) {
129 mSignature = Collections.unmodifiableList(searchedSignature);
130 List<Layer2ClusterMatcher> clusterMatchers = new ArrayList<>();
131 for (List<List<PcapPacket>> cluster : mSignature) {
132 Layer2ClusterMatcher clusterMatcher = new Layer2ClusterMatcher(cluster);
133 clusterMatcher.addObserver(this);
134 clusterMatchers.add(clusterMatcher);
136 mClusterMatchers = Collections.unmodifiableList(clusterMatchers);
137 mPendingMatches = new List[mClusterMatchers.size()];
138 for (int i = 0; i < mPendingMatches.length; i++) {
139 mPendingMatches[i] = new ArrayList<>();
141 Map<Layer2ClusterMatcher, Integer> clusterMatcherIds = new HashMap<>();
142 for (int i = 0; i < mClusterMatchers.size(); i++) {
143 clusterMatcherIds.put(mClusterMatchers.get(i), i);
145 mClusterMatcherIds = Collections.unmodifiableMap(clusterMatcherIds);
146 // Register all cluster matchers to receive a notification whenever a new flow is encountered.
147 mClusterMatchers.forEach(cm -> mFlowReassembler.addObserver(cm));
152 public void gotPacket(PcapPacket packet) {
153 // Forward packet processing to the flow reassembler that in turn notifies the cluster matchers as appropriate
154 mFlowReassembler.gotPacket(packet);
158 public void onMatch(AbstractClusterMatcher clusterMatcher, List<PcapPacket> match) {
159 // TODO: a cluster matcher found a match
160 if (clusterMatcher instanceof Layer2ClusterMatcher) {
161 // Add the match at the corresponding index
162 mPendingMatches[mClusterMatcherIds.get(clusterMatcher)].add(match);
163 checkSignatureMatch();
167 public void addObserver(SignatureDetectorObserver observer) {
168 mObservers.add(observer);
171 public boolean removeObserver(SignatureDetectorObserver observer) {
172 return mObservers.remove(observer);
176 @SuppressWarnings("Duplicates")
177 private void checkSignatureMatch() {
178 // << Graph-based approach using Balint's idea. >>
179 // This implementation assumes that the packets in the inner lists (the sequences) are ordered by asc timestamp.
181 // There cannot be a signature match until each Layer3ClusterMatcher has found a match of its respective sequence.
182 if (Arrays.stream(mPendingMatches).noneMatch(l -> l.isEmpty())) {
184 final SimpleDirectedWeightedGraph<Vertex, DefaultWeightedEdge> graph =
185 new SimpleDirectedWeightedGraph<>(DefaultWeightedEdge.class);
186 // Add a vertex for each match found by all cluster matchers.
187 // And maintain an array to keep track of what cluster matcher each vertex corresponds to
188 final List<Vertex>[] vertices = new List[mPendingMatches.length];
189 for (int i = 0; i < mPendingMatches.length; i++) {
190 vertices[i] = new ArrayList<>();
191 for (List<PcapPacket> sequence : mPendingMatches[i]) {
192 Vertex v = new Vertex(sequence);
193 vertices[i].add(v); // retain reference for later when we are to add edges
194 graph.addVertex(v); // add to vertex to graph
197 // Add dummy source and sink vertices to facilitate search.
198 final Vertex source = new Vertex(null);
199 final Vertex sink = new Vertex(null);
200 graph.addVertex(source);
201 graph.addVertex(sink);
202 // The source is connected to all vertices that wrap the sequences detected by cluster matcher at index 0.
203 // Note: zero cost edges as this is just a dummy link to facilitate search from a common start node.
204 for (Vertex v : vertices[0]) {
205 DefaultWeightedEdge edge = graph.addEdge(source, v);
206 graph.setEdgeWeight(edge, 0.0);
208 // Similarly, all vertices that wrap the sequences detected by the last cluster matcher of the signature
209 // are connected to the sink node.
210 for (Vertex v : vertices[vertices.length-1]) {
211 DefaultWeightedEdge edge = graph.addEdge(v, sink);
212 graph.setEdgeWeight(edge, 0.0);
214 // Now link sequences detected by the cluster matcher at index i to sequences detected by the cluster
215 // matcher at index i+1 if they obey the timestamp constraint (i.e., that the latter is later in time than
217 for (int i = 0; i < vertices.length; i++) {
219 if (j < vertices.length) {
220 for (Vertex iv : vertices[i]) {
221 PcapPacket ivLast = iv.sequence.get(iv.sequence.size()-1);
222 for (Vertex jv : vertices[j]) {
223 PcapPacket jvFirst = jv.sequence.get(jv.sequence.size()-1);
224 if (ivLast.getTimestamp().isBefore(jvFirst.getTimestamp())) {
225 DefaultWeightedEdge edge = graph.addEdge(iv, jv);
226 // The weight is the duration of the i'th sequence plus the duration between the i'th
227 // and i+1'th sequence.
228 Duration d = Duration.
229 between(iv.sequence.get(0).getTimestamp(), jvFirst.getTimestamp());
230 // Unfortunately weights are double values, so must convert from long to double.
231 // TODO: need nano second precision? If so, use d.toNanos().
232 // TODO: risk of overflow when converting from long to double..?
233 graph.setEdgeWeight(edge, Long.valueOf(d.toMillis()).doubleValue());
235 // Alternative version if we cannot assume that sequences are ordered by timestamp:
236 // if (iv.sequence.stream().max(Comparator.comparing(PcapPacket::getTimestamp)).get()
237 // .getTimestamp().isBefore(jv.sequence.stream().min(
238 // Comparator.comparing(PcapPacket::getTimestamp)).get().getTimestamp())) {
245 // Graph construction complete, run shortest-path to find a (potential) signature match.
246 DijkstraShortestPath<Vertex, DefaultWeightedEdge> dijkstra = new DijkstraShortestPath<>(graph);
247 GraphPath<Vertex, DefaultWeightedEdge> shortestPath = dijkstra.getPath(source, sink);
248 if (shortestPath != null) {
249 // The total weight is the duration between the first packet of the first sequence and the last packet
250 // of the last sequence, so we simply have to compare the weight against the timeframe that we allow
251 // the signature to span. For now we just use the inclusion window we defined for training purposes.
252 // Note however, that we must convert back from double to long as the weight is stored as a double in
254 if (((long)shortestPath.getWeight()) < TriggerTrafficExtractor.INCLUSION_WINDOW_MILLIS) {
255 // There's a signature match!
256 // Extract the match from the vertices
257 List<List<PcapPacket>> signatureMatch = new ArrayList<>();
258 for(Vertex v : shortestPath.getVertexList()) {
259 if (v == source || v == sink) {
260 // Skip the dummy source and sink nodes.
263 signatureMatch.add(v.sequence);
264 // As there is a one-to-one correspondence between vertices[] and pendingMatches[], we know that
265 // the sequence we've "consumed" for index i of the matched signature is also at index i in
266 // pendingMatches. We must remove it from pendingMatches so that we don't use it to construct
267 // another signature match in a later call.
268 mPendingMatches[signatureMatch.size()-1].remove(v.sequence);
270 // Declare success: notify observers
271 mObservers.forEach(obs -> obs.onSignatureDetected(mSignature,
272 Collections.unmodifiableList(signatureMatch)));
279 * Encapsulates a {@code List<PcapPacket>} so as to allow the list to be used as a vertex in a graph while avoiding
280 * the expensive {@link AbstractList#equals(Object)} calls when adding vertices to the graph.
281 * Using this wrapper makes the incurred {@code equals(Object)} calls delegate to {@link Object#equals(Object)}
282 * instead of {@link AbstractList#equals(Object)}. The net effect is a faster implementation, but the graph will not
283 * recognize two lists that contain the same items--from a value and not reference point of view--as the same
284 * vertex. However, this is fine for our purposes -- in fact restricting it to reference equality seems more
287 private static class Vertex {
288 private final List<PcapPacket> sequence;
289 private Vertex(List<PcapPacket> wrappedSequence) {
290 sequence = wrappedSequence;