+++ /dev/null
-package edu.uci.iotproject;
-
-import edu.uci.iotproject.analysis.TcpConversationUtils;
-import edu.uci.iotproject.util.PcapPacketUtils;
-import org.pcap4j.core.PcapPacket;
-import org.pcap4j.packet.IpV4Packet;
-import org.pcap4j.packet.Packet;
-import org.pcap4j.packet.TcpPacket;
-
-import java.util.*;
-
-/**
- * Models a (TCP) conversation/connection/session/flow (packet's belonging to the same session between a client and a
- * server).
- * Holds a list of {@link PcapPacket}s identified as pertaining to the flow. Note that this list is <em>not</em>
- * considered when determining equality of two {@code Conversation} instances in order to allow for a
- * {@code Conversation} to function as a key in data structures such as {@link java.util.Map} and {@link java.util.Set}.
- * See {@link #equals(Object)} for the definition of equality.
- *
- * @author Janus Varmarken {@literal <jvarmark@uci.edu>}
- * @author Rahmadi Trimananda {@literal <rtrimana@uci.edu>}
- */
-public class Conversation {
-
- /* Begin instance properties */
- /**
- * The IP of the host that is considered the client (i.e. the host that initiates the conversation)
- * in this conversation.
- */
- private final String mClientIp;
-
- /**
- * The port number used by the host that is considered the client in this conversation.
- */
- private final int mClientPort;
-
- /**
- * The IP of the host that is considered the server (i.e. is the responder) in this conversation.
- */
- private final String mServerIp;
-
- /**
- * The port number used by the server in this conversation.
- */
- private final int mServerPort;
-
- /**
- * The list of packets (with payload) pertaining to this conversation.
- */
- private final List<PcapPacket> mPackets;
-
- /**
- * If {@link #isTls()} is {@code true}, this list contains the subset of {@link #mPackets} which are TLS Application
- * Data packets.
- */
- private final List<PcapPacket> mTlsApplicationDataPackets;
-
- /**
- * Contains the sequence numbers used thus far by the host that is considered the <em>client</em> in this
- * {@code Conversation}.
- * Used for filtering out retransmissions.
- */
- private final Set<Integer> mSeqNumbersClient;
-
- /**
- * Contains the sequence numbers used thus far by the host that is considered the <em>server</em> in this
- * {@code Conversation}.
- * Used for filtering out retransmissions.
- */
- private final Set<Integer> mSeqNumbersSrv;
-
- /**
- * List of SYN packets pertaining to this conversation.
- */
- private final List<PcapPacket> mSynPackets;
-
- /**
- * List of pairs FINs and their corresponding ACKs associated with this conversation.
- */
- private final List<FinAckPair> mFinPackets;
-
- /**
- * List of RST packets associated with this conversation.
- */
- private final List<PcapPacket> mRstPackets;
-
- /**
- * Boolean to mark the packet as Application Data based on the previous packet that reaches MTU
- */
- private boolean mApplicationData;
- /* End instance properties */
-
- /**
- * Factory method for creating a {@code Conversation} from a {@link PcapPacket}.
- * @param pcapPacket The {@code PcapPacket} that wraps a TCP segment for which a {@code Conversation} is to be initiated.
- * @param clientIsSrc If {@code true}, the source address and source port found in the IP datagram and TCP segment
- * wrapped in the {@code PcapPacket} are regarded as pertaining to the client, and the destination
- * address and destination port are regarded as pertaining to the server---and vice versa if set
- * to {@code false}.
- * @return A {@code Conversation} initiated with ip:port for client and server according to the direction of the packet.
- */
- public static Conversation fromPcapPacket(PcapPacket pcapPacket, boolean clientIsSrc) {
- IpV4Packet ipPacket = pcapPacket.get(IpV4Packet.class);
- TcpPacket tcpPacket = pcapPacket.get(TcpPacket.class);
- String clientIp = clientIsSrc ? ipPacket.getHeader().getSrcAddr().getHostAddress() :
- ipPacket.getHeader().getDstAddr().getHostAddress();
- String srvIp = clientIsSrc ? ipPacket.getHeader().getDstAddr().getHostAddress() :
- ipPacket.getHeader().getSrcAddr().getHostAddress();
- int clientPort = clientIsSrc ? tcpPacket.getHeader().getSrcPort().valueAsInt() :
- tcpPacket.getHeader().getDstPort().valueAsInt();
- int srvPort = clientIsSrc ? tcpPacket.getHeader().getDstPort().valueAsInt() :
- tcpPacket.getHeader().getSrcPort().valueAsInt();
- return new Conversation(clientIp, clientPort, srvIp, srvPort);
- }
-
- /**
- * Constructs a new {@code Conversation}.
- * @param clientIp The IP of the host that is considered the client (i.e. the host that initiates the conversation)
- * in the conversation.
- * @param clientPort The port number used by the client for the conversation.
- * @param serverIp The IP of the host that is considered the server (i.e. is the responder) in the conversation.
- * @param serverPort The port number used by the server for the conversation.
- */
- public Conversation(String clientIp, int clientPort, String serverIp, int serverPort) {
- this.mClientIp = clientIp;
- this.mClientPort = clientPort;
- this.mServerIp = serverIp;
- this.mServerPort = serverPort;
- this.mPackets = new ArrayList<>();
- this.mTlsApplicationDataPackets = new ArrayList<>();
- this.mSeqNumbersClient = new HashSet<>();
- this.mSeqNumbersSrv = new HashSet<>();
- this.mSynPackets = new ArrayList<>();
- this.mFinPackets = new ArrayList<>();
- this.mRstPackets = new ArrayList<>();
- this.mApplicationData = false;
- }
-
- /**
- * Add a packet to the list of packets associated with this conversation.
- * @param packet The packet that is to be added to (associated with) this conversation.
- * @param ignoreRetransmissions Boolean value indicating if retransmissions should be ignored.
- * If set to {@code true}, {@code packet} will <em>not</em> be added to the
- * internal list of packets pertaining to this {@code Conversation}
- * <em>iff</em> the sequence number of {@code packet} was already
- * seen in a previous packet.
- */
- public void addPacket(PcapPacket packet, boolean ignoreRetransmissions) {
- // Precondition: verify that packet does indeed pertain to conversation.
- onAddPrecondition(packet);
- if (ignoreRetransmissions && isRetransmission(packet)) {
- // Packet is a retransmission. Ignore it.
- return;
- }
- // Select direction-dependent set of sequence numbers seen so far and update it with sequence number of new packet.
- addSeqNumber(packet);
- // Finally add packet to list of packets pertaining to this conversation.
- mPackets.add(packet);
- // Preserve order of packets in list: sort according to timestamp.
- if (mPackets.size() > 1 &&
- mPackets.get(mPackets.size()-1).getTimestamp().isBefore(mPackets.get(mPackets.size()-2).getTimestamp())) {
- Collections.sort(mPackets, (o1, o2) -> {
- if (o1.getTimestamp().isBefore(o2.getTimestamp())) { return -1; }
- else if (o2.getTimestamp().isBefore(o1.getTimestamp())) { return 1; }
- else { return 0; }
- });
- }
- // If TLS, inspect packet to see if it's a TLS Application Data packet, and if so add it to the list of TLS
- // Application Data packets.
- if (isTls()) {
- TcpPacket tcpPacket = packet.get(TcpPacket.class);
- Packet tcpPayload = tcpPacket.getPayload();
- if (tcpPayload == null) {
- return;
- }
- byte[] rawPayload = tcpPayload.getRawData();
- // The SSL record header is at the front of the payload and is 5 bytes long.
- // The SSL record header type field (the first byte) is set to 23 if it is an Application Data packet.
- if (rawPayload != null && rawPayload.length >= 5) {
- if (rawPayload[0] == 23) {
- mTlsApplicationDataPackets.add(packet);
- // Consider the following packet a data packet if this packet's size == MTU size 1448
- if (rawPayload.length >= 1448)
- mApplicationData = true;
- } else if (rawPayload[0] == 20) {
- // Do nothing for now - CHANGE_CIPHER_SPEC
- } else if (rawPayload[0] == 21) {
- // Do nothing for now - ALERT
- } else if (rawPayload[0] == 22) {
- // Do nothing for now - HANDSHAKE
- } else {
- // If it is TLS with payload, but rawPayload[0] != 23
- if (mApplicationData == true) {
- // It is a continuation of the previous packet if the previous packet reaches MTU size 1448 and
- // it is not either type 20, 21, or 22
- mTlsApplicationDataPackets.add(packet);
- if (rawPayload.length < 1448)
- mApplicationData = false;
- }
- }
- }
- }
- }
-
- /**
- * Get a list of packets pertaining to this {@code Conversation}.
- * The returned list is a read-only list.
- * @return the list of packets pertaining to this {@code Conversation}.
- */
- public List<PcapPacket> getPackets() {
- // Return read-only view to prevent external code from manipulating internal state (preserve invariant).
- return Collections.unmodifiableList(mPackets);
- }
-
- /**
- * Records a TCP SYN packet as pertaining to this conversation (adds it to the the internal list).
- * Attempts to add duplicate SYN packets will be ignored, and the caller is made aware of the attempt to add a
- * duplicate by the return value being {@code false}.
- *
- * @param synPacket A {@link PcapPacket} wrapping a TCP SYN packet.
- * @return {@code true} if the packet was successfully added to this {@code Conversation}, {@code false} otherwise.
- */
- public boolean addSynPacket(PcapPacket synPacket) {
- onAddPrecondition(synPacket);
- final IpV4Packet synPacketIpSection = synPacket.get(IpV4Packet.class);
- final TcpPacket synPacketTcpSection = synPacket.get(TcpPacket.class);
- if (synPacketTcpSection == null || !synPacketTcpSection.getHeader().getSyn()) {
- throw new IllegalArgumentException("Not a SYN packet.");
- }
- // We are only interested in recording one copy of the two SYN packets (one SYN packet in each direction), i.e.,
- // we want to discard retransmitted SYN packets.
- if (mSynPackets.size() >= 2) {
- return false;
- }
- // Check the set of recorded SYN packets to see if we have already recorded a SYN packet going in the same
- // direction as the packet given in the argument.
- boolean matchingPrevSyn = mSynPackets.stream().anyMatch(p -> {
- IpV4Packet pIp = p.get(IpV4Packet.class);
- TcpPacket pTcp = p.get(TcpPacket.class);
- boolean srcAddrMatch = synPacketIpSection.getHeader().getSrcAddr().getHostAddress().
- equals(pIp.getHeader().getSrcAddr().getHostAddress());
- boolean dstAddrMatch = synPacketIpSection.getHeader().getDstAddr().getHostAddress().
- equals(pIp.getHeader().getDstAddr().getHostAddress());
- boolean srcPortMatch = synPacketTcpSection.getHeader().getSrcPort().valueAsInt() ==
- pTcp.getHeader().getSrcPort().valueAsInt();
- boolean dstPortMatch = synPacketTcpSection.getHeader().getDstPort().valueAsInt() ==
- pTcp.getHeader().getDstPort().valueAsInt();
- return srcAddrMatch && dstAddrMatch && srcPortMatch && dstPortMatch;
- });
- if (matchingPrevSyn) {
- return false;
- }
- // Update direction-dependent set of sequence numbers and record/log packet.
- addSeqNumber(synPacket);
- return mSynPackets.add(synPacket);
-
- /*
- mSynPackets.stream().anyMatch(p -> {
- IpV4Packet pIp = p.get(IpV4Packet.class);
- TcpPacket pTcp = p.get(TcpPacket.class);
- boolean srcAddrMatch = synPacketIpSection.getHeader().getSrcAddr().getHostAddress().
- equals(pIp.getHeader().getSrcAddr().getHostAddress());
- boolean dstAddrMatch = synPacketIpSection.getHeader().getDstAddr().getHostAddress().
- equals(pIp.getHeader().getDstAddr().getHostAddress());
- boolean srcPortMatch = synPacketTcpSection.getHeader().getSrcPort().valueAsInt() ==
- pTcp.getHeader().getSrcPort().valueAsInt();
- boolean dstPortMatch = synPacketTcpSection.getHeader().getDstPort().value() ==
- pTcp.getHeader().getDstPort().value();
-
- boolean fourTupleMatch = srcAddrMatch && dstAddrMatch && srcPortMatch && dstPortMatch;
-
- boolean seqNoMatch = synPacketTcpSection.getHeader().getSequenceNumber() ==
- pTcp.getHeader().getSequenceNumber();
-
- if (fourTupleMatch && !seqNoMatch) {
- // If the four tuple that identifies the conversation matches, but the sequence number is different,
- // it means that this SYN packet is, in fact, an attempt to establish a **new** connection, and hence
- // the given packet is NOT part of this conversation, even though the ip:port combinations are (by
- // chance) selected such that they match this conversation.
- throw new IllegalArgumentException("Attempt to add SYN packet that belongs to a different conversation " +
- "(which is identified by the same four tuple as this conversation)");
- }
- return fourTupleMatch && seqNoMatch;
- });
- */
- }
-
- /**
- * Get a list of SYN packets pertaining to this {@code Conversation}.
- * The returned list is a read-only list.
- * @return the list of SYN packets pertaining to this {@code Conversation}.
- */
- public List<PcapPacket> getSynPackets() {
- return Collections.unmodifiableList(mSynPackets);
- }
-
- /**
- * Adds a TCP FIN packet to the list of TCP FIN packets associated with this conversation.
- * @param finPacket The TCP FIN packet that is to be added to (associated with) this conversation.
- */
- public void addFinPacket(PcapPacket finPacket) {
- // Precondition: verify that packet does indeed pertain to conversation.
- onAddPrecondition(finPacket);
- // TODO: should call addSeqNumber here?
- addSeqNumber(finPacket);
- mFinPackets.add(new FinAckPair(finPacket));
- }
-
- /**
- * Attempt to ACK any FIN packets held by this conversation.
- * @param ackPacket The ACK for a FIN previously added to this conversation.
- */
- public void attemptAcknowledgementOfFin(PcapPacket ackPacket) {
- // Precondition: verify that the packet pertains to this conversation.
- onAddPrecondition(ackPacket);
- // Mark unack'ed FIN(s) that this ACK matches as ACK'ed (there might be more than one in case of retransmissions..?)
- mFinPackets.replaceAll(finAckPair -> !finAckPair.isAcknowledged() && finAckPair.isCorrespondingAckPacket(ackPacket) ? new FinAckPair(finAckPair.getFinPacket(), ackPacket) : finAckPair);
- }
-
- /**
- * Retrieves an unmodifiable view of the list of {@link FinAckPair}s associated with this {@code Conversation}.
- * @return an unmodifiable view of the list of {@link FinAckPair}s associated with this {@code Conversation}.
- */
- public List<FinAckPair> getFinAckPairs() {
- return Collections.unmodifiableList(mFinPackets);
- }
-
- /**
- * Get if this {@code Conversation} is considered to have been gracefully shut down.
- * A {@code Conversation} has been gracefully shut down if it contains a FIN+ACK pair for both directions
- * (client to server, and server to client).
- * @return {@code true} if the connection has been gracefully shut down, false otherwise.
- */
- public boolean isGracefullyShutdown() {
- // The conversation has been gracefully shut down if we have recorded a FIN from both the client and the server which have both been ack'ed.
- return mFinPackets.stream().anyMatch(finAckPair -> finAckPair.isAcknowledged() && PcapPacketUtils.isSource(finAckPair.getFinPacket(), mClientIp, mClientPort)) &&
- mFinPackets.stream().anyMatch(finAckPair -> finAckPair.isAcknowledged() && PcapPacketUtils.isSource(finAckPair.getFinPacket(), mServerIp, mServerPort));
- }
-
- /**
- * Add a TCP segment for which the RST flag is set to this {@code Conversation}.
- * @param packet A {@link PcapPacket} wrapping a TCP segment pertaining to this {@code Conversation} for which the
- * RST flag is set.
- */
- public void addRstPacket(PcapPacket packet) {
- /*
- * TODO:
- * When now also keeping track of RST packets, should we also...?
- * 1) Prevent later packets from being added once a RST segment has been added?
- * 2) Extend 'isGracefullyShutdown()' to also consider RST segments, or add another method, 'isShutdown()' that
- * both considers FIN/ACK (graceful) as well as RST (abrupt/"ungraceful") shutdown?
- * 3) Should it be impossible to associate more than one RST segment with each Conversation?
- */
- onAddPrecondition(packet);
- TcpPacket tcpPacket = packet.get(TcpPacket.class);
- if (tcpPacket == null || !tcpPacket.getHeader().getRst()) {
- throw new IllegalArgumentException("not a RST packet");
- }
- mRstPackets.add(packet);
- }
-
- /**
- * Get the TCP segments pertaining to this {@code Conversation} for which it was detected that the RST flag is set.
- * @return the TCP segments pertaining to this {@code Conversation} for which it was detected that the RST flag is
- * set.
- */
- public List<PcapPacket> getRstPackets() {
- return Collections.unmodifiableList(mRstPackets);
- }
-
- // =========================================================================================================
- // We simply reuse equals and hashCode methods of String.class to be able to use this class as a key
- // in a Map.
-
- /**
- * <em>Note:</em> currently, equality is determined based on pairwise equality of the elements of the four tuple
- * ({@link #mClientIp}, {@link #mClientPort}, {@link #mServerIp}, {@link #mServerPort}) for {@code this} and
- * {@code obj}.
- * @param obj The object to test for equality with {@code this}.
- * @return {@code true} if {@code obj} is considered equal to {@code this} based on the definition of equality given above.
- */
- @Override
- public boolean equals(Object obj) {
- return obj instanceof Conversation && this.toString().equals(obj.toString());
- }
-
- @Override
- public int hashCode() {
- return toString().hashCode();
- }
- // =========================================================================================================
-
- @Override
- public String toString() {
- return String.format("%s:%d %s:%d", mClientIp, mClientPort, mServerIp, mServerPort);
- }
-
- /**
- * Invoke to verify that the precondition holds when a caller attempts to add a packet to this {@code Conversation}.
- * An {@link IllegalArgumentException} is thrown if the precondition is violated.
- * @param packet the packet to be added to this {@code Conversation}
- */
- private void onAddPrecondition(PcapPacket packet) {
- // Apply precondition to preserve class invariant: all packets in mPackets must match the 4 tuple that
- // defines the conversation.
- IpV4Packet ipPacket = Objects.requireNonNull(packet.get(IpV4Packet.class));
- // For now we only support TCP flows.
- TcpPacket tcpPacket = Objects.requireNonNull(packet.get(TcpPacket.class));
- String ipSrc = ipPacket.getHeader().getSrcAddr().getHostAddress();
- String ipDst = ipPacket.getHeader().getDstAddr().getHostAddress();
- int srcPort = tcpPacket.getHeader().getSrcPort().valueAsInt();
- int dstPort = tcpPacket.getHeader().getDstPort().valueAsInt();
- String clientIp, serverIp;
- int clientPort, serverPort;
- if (ipSrc.equals(mClientIp)) {
- clientIp = ipSrc;
- clientPort = srcPort;
- serverIp = ipDst;
- serverPort = dstPort;
- } else {
- clientIp = ipDst;
- clientPort = dstPort;
- serverIp = ipSrc;
- serverPort = srcPort;
- }
- if (!(clientIp.equals(mClientIp) && clientPort == mClientPort &&
- serverIp.equals(mServerIp) && serverPort == mServerPort)) {
- throw new IllegalArgumentException(
- String.format("Attempt to add packet that does not pertain to %s",
- Conversation.class.getSimpleName()));
- }
- }
-
- /**
- * <p>
- * Determines if the TCP packet contained in {@code packet} is a retransmission of a previously seen (logged)
- * packet.
- * </p>
- *
- * <b>
- * TODO:
- * the current implementation, which uses a set of previously seen sequence numbers, will consider a segment
- * with a reused sequence number---occurring as a result of sequence number wrap around for a very long-lived
- * connection---as a retransmission (and may therefore end up discarding it even though it is in fact NOT a
- * retransmission). Ideas?
- * </b>
- *
- * @param packet The packet.
- * @return {@code true} if {@code packet} was determined to be a retransmission, {@code false} otherwise.
- */
- public boolean isRetransmission(PcapPacket packet) {
- // Extract sequence number.
- int seqNo = packet.get(TcpPacket.class).getHeader().getSequenceNumber();
- switch (getDirection(packet)) {
- case CLIENT_TO_SERVER:
- return mSeqNumbersClient.contains(seqNo);
- case SERVER_TO_CLIENT:
- return mSeqNumbersSrv.contains(seqNo);
- default:
- throw new AssertionError(String.format("Unexpected value of enum '%s'",
- Direction.class.getSimpleName()));
- }
- }
-
- /**
- * <p>
- * Is this {@code Conversation} a TLS session?
- * </p>
- *
- * <em>Note: the current implementation simply examines the port number(s) for 443; it does <b>not</b> verify if the
- * application data is indeed encrypted.</em>
- *
- * @return {@code true} if this {@code Conversation} is interpreted as a TLS session, {@code false} otherwise.
- */
- public boolean isTls() {
- /*
- * TODO:
- * - may want to change this to be "return mServerPort == 443 || mClientPort == 443;" in order to also detect
- * TLS in those cases where it is not possible to correctly label who is the client and who is the server,
- * i.e., when the trace does not contain the SYN/SYNACK exchange.
- * - current implementation relies on the server using the conventional TLS port number; may instead want to
- * inspect the first 4 bytes of each potential TLS packet to see if they match the SSL record header.
- *
- * 08/31/18: Added unconvetional TLS ports used by WeMo plugs and LiFX bulb.
- * 09/20/18: Moved hardcoded ports to other class to allow other classes to query the set of TLS ports.
- */
- return TcpConversationUtils.isTlsPort(mServerPort);
- }
-
- /**
- * If this {@code Conversation} is backing a TLS session (i.e., if the value of {@link #isTls()} is {@code true}),
- * get the packets labeled as TLS Application Data packets. This is a subset of the full set of payload-carrying
- * packets (as returned by {@link #getPackets()}). An exception is thrown if this method is invoked on a
- * {@code Conversation} for which {@link #isTls()} returns {@code false}.
- *
- * @return A list containing exactly those packets that could be identified as TLS Application Data packets (through
- * inspecting of the SSL record header). The list may be empty, if no TLS application data packets have been
- * recorded for this {@code Conversation}.
- */
- public List<PcapPacket> getTlsApplicationDataPackets() {
- if (!isTls()) {
- throw new NoSuchElementException("cannot get TLS Application Data packets for non-TLS TCP conversation");
- }
- return Collections.unmodifiableList(mTlsApplicationDataPackets);
- }
-
- /**
- * Extracts the TCP sequence number from {@code packet} and adds it to the proper set of sequence numbers by
- * analyzing the direction of the packet.
- * @param packet A TCP packet (wrapped in a {@code PcapPacket}) that was added to this conversation and whose
- * sequence number is to be recorded as seen.
- */
- private void addSeqNumber(PcapPacket packet) {
- // Note: below check is redundant if client code is correct as the call to check the precondition should already
- // have been made by the addXPacket method that invokes this method. As such, the call below may be removed in
- // favor of speed, but the improvement will be minor, hence the added safety may be worth it.
- onAddPrecondition(packet);
- // Extract sequence number.
- int seqNo = packet.get(TcpPacket.class).getHeader().getSequenceNumber();
- // Determine direction of packet and add packet's sequence number to corresponding set of sequence numbers.
- switch (getDirection(packet)) {
- case CLIENT_TO_SERVER:
- // Client to server packet.
- mSeqNumbersClient.add(seqNo);
- break;
- case SERVER_TO_CLIENT:
- // Server to client packet.
- mSeqNumbersSrv.add(seqNo);
- break;
- default:
- throw new AssertionError(String.format("Unexpected value of enum '%s'",
- Direction.class.getSimpleName()));
- }
- }
-
- /**
- * Determine the direction of {@code packet}. An {@link IllegalArgumentException} is thrown if {@code packet} does
- * not pertain to this conversation.
- *
- * @param packet The packet whose direction is to be determined.
- * @return A {@link Direction} indicating the direction of the packet.
- */
- public Direction getDirection(PcapPacket packet) {
- IpV4Packet ipPacket = packet.get(IpV4Packet.class);
- String ipSrc = ipPacket.getHeader().getSrcAddr().getHostAddress();
- String ipDst = ipPacket.getHeader().getDstAddr().getHostAddress();
- // Determine direction of packet.
- if (ipSrc.equals(mClientIp) && ipDst.equals(mServerIp)) {
- // Client to server packet.
- return Direction.CLIENT_TO_SERVER;
- } else if (ipSrc.equals(mServerIp) && ipDst.equals(mClientIp)) {
- // Server to client packet.
- return Direction.SERVER_TO_CLIENT;
- } else {
- throw new IllegalArgumentException("getDirection: packet not related to " + getClass().getSimpleName());
- }
- }
-
- /**
- * Utility enum for expressing the direction of a packet pertaining to this {@code Conversation}.
- */
- public enum Direction {
-
- CLIENT_TO_SERVER {
- @Override
- public String toCompactString() {
- return "*";
- }
- },
- SERVER_TO_CLIENT {
- @Override
- public String toCompactString() {
- return "";
- }
- };
-
- /**
- * Get a compact string representation of this {@code Direction}.
- * @return a compact string representation of this {@code Direction}.
- */
- abstract public String toCompactString();
-
- }
-
-}
+++ /dev/null
-package edu.uci.iotproject;
-
-import org.pcap4j.core.PcapPacket;
-import org.pcap4j.packet.IpV4Packet;
-import org.pcap4j.packet.TcpPacket;
-
-/**
- * Groups a FIN packet and its corresponding ACK packet. <b>Immutable and thread safe</b>.
- *
- * @author Janus Varmarken {@literal <jvarmark@uci.edu>}
- * @author Rahmadi Trimananda {@literal <rtrimana@uci.edu>}
- */
-public class FinAckPair {
-
- private final PcapPacket mFinPacket;
- private final PcapPacket mCorrespondingAckPacket;
-
- /**
- * Constructs a {@code FinAckPair} given a FIN packet.
- * The corresponding ACK packet field is set to {@code null}.
- * @param finPacket A FIN packet.
- */
- public FinAckPair(PcapPacket finPacket) {
- if (!finPacket.get(TcpPacket.class).getHeader().getFin()) {
- throw new IllegalArgumentException("not a FIN packet");
- }
- mFinPacket = finPacket;
- mCorrespondingAckPacket = null;
- }
-
- /**
- * Constructs a {@code FinAckPair} given a FIN and an ACK packet.
- * @param finPacket A FIN packet.
- * @param correspondingAckPacket The ACK packet corresponding to {@code finPacket}.
- */
- public FinAckPair(PcapPacket finPacket, PcapPacket correspondingAckPacket) {
- // Enforce class invariant, i.e. that the FIN and ACK are related.
- // Note that it is indirectly checked whether finPacket is indeed a FIN packet
- // as isCorrespondingAckPacket calls the single parameter constructor.
- if (!FinAckPair.isCorrespondingAckPacket(finPacket, correspondingAckPacket)) {
- throw new IllegalArgumentException("FIN and ACK not related");
- }
- mFinPacket = finPacket;
- mCorrespondingAckPacket = correspondingAckPacket;
- }
-
- /**
- * Get the FIN packet of this pair.
- * @return the FIN packet of this pair.
- */
- public PcapPacket getFinPacket() {
- return mFinPacket;
- }
-
- /**
- * Get the corresponding ACK packet of this pair, if any.
- * @return the corresponding ACK packet of this pair, if any.
- */
- public PcapPacket getCorrespondingAckPacket() {
- return mCorrespondingAckPacket;
- }
-
- /**
- * Was the FIN in this {@code FinAckPair} acknowledged?
- *
- * @return {@code true} if the corresponding ACK has been set in this {@code FinAckPair}.
- */
- public boolean isAcknowledged() {
- return mFinPacket != null && mCorrespondingAckPacket != null;
- }
-
- /**
- * Checks if a given packet is an ACK corresponding to the FIN packet in this {@code FinAckPair}.
- * @return {@code true} if {@code packet} is an ACK that corresponds to the FIN in this pair, {@code false} otherwise.
- */
- public boolean isCorrespondingAckPacket(PcapPacket packet) {
- IpV4Packet inputIpPacket = packet.get(IpV4Packet.class);
- TcpPacket inputTcpPacket = packet.get(TcpPacket.class);
- if (inputIpPacket == null || inputTcpPacket == null || !inputTcpPacket.getHeader().getAck()) {
- return false;
- }
-
- IpV4Packet finIpPacket = mFinPacket.get(IpV4Packet.class);
- TcpPacket finTcpPacket = mFinPacket.get(TcpPacket.class);
-
- // Extract (srcIp:port,dstIp:port) for input and member (FIN) packets.
- String inputPacketIpSrc = inputIpPacket.getHeader().getSrcAddr().getHostAddress();
- String inputPacketIpDst = inputIpPacket.getHeader().getDstAddr().getHostAddress();
- int inputPacketPortSrc = inputTcpPacket.getHeader().getSrcPort().valueAsInt();
- int inputPacketPortDst = inputTcpPacket.getHeader().getDstPort().valueAsInt();
- String finPacketIpSrc = finIpPacket.getHeader().getSrcAddr().getHostAddress();
- String finPacketIpDst = finIpPacket.getHeader().getDstAddr().getHostAddress();
- int finPacketPortSrc = finTcpPacket.getHeader().getSrcPort().valueAsInt();
- int finPacketPortDst = finTcpPacket.getHeader().getDstPort().valueAsInt();
-
- // For the two packets to be related, the dst of one must be the src of the other.
- // Split into multiple if statements for readability. First check IP fields, then ports.
- if (!(inputPacketIpDst.equals(finPacketIpSrc) && finPacketIpDst.equals(inputPacketIpSrc))) {
- return false;
- }
- if (!(inputPacketPortDst == finPacketPortSrc && finPacketPortDst == inputPacketPortSrc)) {
- return false;
- }
-
- // Packets are (most likely) related (part of same conversation/stream).
- // Now all that is left for us to check is if the sequence numbers match.
- // Note: recall that the FIN packet advances the seq numbers by 1,
- // so the ACK number will be one larger than the seq. number in the FIN packet.
- return inputTcpPacket.getHeader().getAcknowledgmentNumber() == finTcpPacket.getHeader().getSequenceNumber() + 1;
- }
-
- /**
- * Static method to check if two given packets are a FIN and the corresponding ACK packet.
- * The purpose of this method is a workaround to enforce the class invariant in the two parameter constructor.
- * Specifically, the following should be avoided:
- * <pre>
- * public FinAckPair(PcapPacket finPacket, PcapPacket correspondingAckPacket) {
- * mFinPacket = finPacket;
- * // Below line is considered bad practice as the object has not been fully initialized at this stage.
- * if (!this.isCorrespondingAckPacket(correspondingAckPacket)) {
- * // ... throw exception
- * }
- * }
- * </pre>
- * @param finPacket The FIN packet.
- * @param ackPacket The ACK packet that is to be checked if it corresponds to the given FIN packet.
- * @return {@code true} if the ACK corresponds to the FIN, {@code false} otherwise.
- */
- private static boolean isCorrespondingAckPacket(PcapPacket finPacket, PcapPacket ackPacket) {
- FinAckPair tmp = new FinAckPair(finPacket);
- return tmp.isCorrespondingAckPacket(ackPacket);
- }
-
-}
import edu.uci.iotproject.comparison.ComparisonFunctions;
import edu.uci.iotproject.comparison.CompleteMatchPatternComparisonResult;
import edu.uci.iotproject.comparison.PatternComparisonTask;
+import edu.uci.iotproject.trafficreassembly.layer3.Conversation;
import org.pcap4j.core.NotOpenException;
import org.pcap4j.core.PcapHandle;
import org.pcap4j.core.PcapNativeException;
import java.net.UnknownHostException;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
-import java.time.temporal.ChronoField;
import java.util.*;
import java.util.concurrent.*;
+++ /dev/null
-package edu.uci.iotproject;
-
-import org.pcap4j.core.PacketListener;
-import org.pcap4j.core.PcapPacket;
-import org.pcap4j.packet.EthernetPacket;
-import org.pcap4j.util.MacAddress;
-
-import java.util.*;
-
-/**
- * Reassembles traffic flows at layer 2, i.e., for each combination of hosts, creates a list of packets exchanged
- * between said hosts.
- *
- * @author Janus Varmarken {@literal <jvarmark@uci.edu>}
- * @author Rahmadi Trimananda {@literal <rtrimana@uci.edu>}
- */
-public class L2FlowReassembler implements PacketListener {
-
- /**
- * Maps a pair of MAC addresses to the packets exchanged between the two hosts.
- * The key is the concatenation of the two MAC addresses in hex string format, where the lexicographically smaller
- * MAC is at the front of the string.
- */
- private final Map<String, Layer2Flow> mFlows = new HashMap<>();
-
- private final List<Layer2FlowReassemblerObserver> mObservers = new ArrayList<>();
-
- @Override
- public void gotPacket(PcapPacket packet) {
- // TODO: update to 802.11 packet...?
- EthernetPacket ethPkt = packet.get(EthernetPacket.class);
-
- MacAddress srcAddr = ethPkt.getHeader().getSrcAddr();
- MacAddress dstAddr = ethPkt.getHeader().getDstAddr();
-
- String key = keyFromAddresses(srcAddr, dstAddr);
- // Create a new list if this pair of MAC addresses where not previously encountered and add packet to that list,
- // or simply add to an existing list if one is present.
- mFlows.computeIfAbsent(key, k -> {
- Layer2Flow newFlow = new Layer2Flow(srcAddr, dstAddr);
- // Inform observers of the new flow
- mObservers.forEach(o -> o.onNewFlow(this, newFlow));
- return newFlow;
- }).addPacket(packet);
- }
-
- public void addObserver(Layer2FlowReassemblerObserver observer) {
- mObservers.add(observer);
- }
-
- public void removeObserver(Layer2FlowReassemblerObserver observer) {
- mObservers.remove(observer);
- }
-
- /**
- * Get the traffic flow between two local endpoints ({@link MacAddress}es).
- * @param addr1 The first endpoint.
- * @param addr2 The second endpoint
- * @return The traffic exchanged between the two endpoints.
- */
- public Layer2Flow getFlowForAddresses(MacAddress addr1, MacAddress addr2) {
- return mFlows.get(keyFromAddresses(addr1, addr2));
- }
-
- /**
- * Get all traffic flows, i.e., a traffic flow for each unique pair of endpoints (MAC addresses).
- * @return All traffic flows.
- */
- public Collection<Layer2Flow> getFlows() {
- return mFlows.values();
- }
-
- /**
- * Given two {@link MacAddress}es, generates the corresponding key string used in {@link #mFlows}.
- * @param addr1 The first address.
- * @param addr2 The second address.
- * @return the key string used in {@link #mFlows} corresponding to the two addresses.
- */
- private String keyFromAddresses(MacAddress addr1, MacAddress addr2) {
- String addr1Str = addr1.toString();
- String addr2Str = addr2.toString();
- return addr1Str.compareTo(addr2Str) < 0 ? addr1Str + addr2Str : addr2Str + addr1Str;
- }
-}
+++ /dev/null
-package edu.uci.iotproject;
-
-import edu.uci.iotproject.detection.Layer2FlowObserver;
-import org.pcap4j.core.PcapPacket;
-import org.pcap4j.packet.EthernetPacket;
-import org.pcap4j.util.MacAddress;
-
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-
-/**
- * The packets exchanged between two endpoints (MAC addresses).
- *
- * @author Janus Varmarken
- */
-public class Layer2Flow {
-
- private final MacAddress mEndpoint1;
- private final MacAddress mEndpoint2;
-
- private final List<Layer2FlowObserver> mFlowObservers = new ArrayList<>();
-
- public Layer2Flow(MacAddress endpoint1, MacAddress endpoint2) {
- mEndpoint1 = endpoint1;
- mEndpoint2 = endpoint2;
- }
-
- public void addFlowObserver(Layer2FlowObserver observer) {
- mFlowObservers.add(observer);
- }
-
- public void removeFlowObserver(Layer2FlowObserver observer) {
- mFlowObservers.remove(observer);
- }
-
- /**
- * The packets in the flow.
- */
- private final List<PcapPacket> mPackets = new ArrayList<>();
-
- /**
- * Add a packet to this flow.
- * @param packet The packet that is to be added to the flow.
- */
- public void addPacket(PcapPacket packet) {
- verifyAddresses(packet);
- mPackets.add(packet);
- // Notify flow observers of the new packet
- mFlowObservers.forEach(o -> o.onNewPacket(this, packet));
- }
-
- public List<PcapPacket> getPackets() {
- return Collections.unmodifiableList(mPackets);
- }
-
- private void verifyAddresses(PcapPacket packet) {
- EthernetPacket ethPkt = packet.get(EthernetPacket.class);
- MacAddress srcAddr = ethPkt.getHeader().getSrcAddr();
- MacAddress dstAddr = ethPkt.getHeader().getDstAddr();
- if ((mEndpoint1.equals(srcAddr) && mEndpoint2.equals(dstAddr)) ||
- (mEndpoint1.equals(dstAddr) && mEndpoint2.equals(srcAddr))) {
- // All is good.
- return;
- }
- throw new IllegalArgumentException("Mismatch in MACs: packet does not pertain to this flow");
- }
-
-}
-
-
-
-/*
-
-
- Packet stream -> flow reassembler -> flow1, flow2, flow3... -> for each flow, keep a sequence matcher for each sequence of cluster
-
-
- */
\ No newline at end of file
+++ /dev/null
-package edu.uci.iotproject;
-
-/**
- * For observing a {@link L2FlowReassembler}.
- *
- * @author Janus Varmarken
- */
-public interface Layer2FlowReassemblerObserver {
-
- /**
- * Invoked when when a {@link L2FlowReassembler} detects a new flow (i.e., when it encounters traffic between two
- * MAC addresses that has not previously communicated in the traffic trace).
- *
- * @param reassembler The {@link L2FlowReassembler} that detected the new flow.
- * @param newFlow The new flow.
- */
- void onNewFlow(L2FlowReassembler reassembler, Layer2Flow newFlow);
-
-}
import static edu.uci.iotproject.analysis.UserAction.Type;
import edu.uci.iotproject.analysis.*;
-import edu.uci.iotproject.comparison.seqalignment.ExtractedSequence;
-import edu.uci.iotproject.comparison.seqalignment.SequenceAlignment;
-import edu.uci.iotproject.comparison.seqalignment.SequenceExtraction;
import edu.uci.iotproject.io.TriggerTimesFileReader;
+import edu.uci.iotproject.trafficreassembly.layer3.Conversation;
+import edu.uci.iotproject.trafficreassembly.layer3.TcpReassembler;
import edu.uci.iotproject.util.PcapPacketUtils;
import edu.uci.iotproject.util.PrintUtils;
import org.apache.commons.math3.stat.clustering.Cluster;
import org.pcap4j.packet.namednumber.DataLinkType;
import java.io.EOFException;
-import java.io.File;
-import java.io.PrintWriter;
import java.net.UnknownHostException;
import java.time.Instant;
import java.util.*;
+++ /dev/null
-package edu.uci.iotproject;
-
-import org.pcap4j.core.PacketListener;
-import org.pcap4j.core.PcapPacket;
-import org.pcap4j.packet.*;
-
-import java.util.*;
-
-/**
- * Reassembles TCP conversations (streams).
- * <b>Note: current version only supports TCP over IPv4.</b>
- *
- * @author Janus Varmarken {@literal <jvarmark@uci.edu>}
- * @author Rahmadi Trimananda {@literal <rtrimana@uci.edu>}
- */
-public class TcpReassembler implements PacketListener {
-
- /**
- * Holds <em>open</em> {@link Conversation}s, i.e., {@code Conversation}s that have <em>not</em> been detected as
- * (gracefully) terminated based on the set of packets observed thus far.
- * A {@link Conversation} is moved to {@link #mTerminatedConversations} if it can be determined that it is has
- * terminated. Termination can be detected by a) observing two {@link FinAckPair}s, one in each direction, (graceful
- * termination, see {@link Conversation#isGracefullyShutdown()}) or b) by observing a SYN packet that matches the
- * four tuple of an existing {@code Conversation}, but which holds a <em>different</em> sequence number than the
- * same-direction SYN packet recorded for the {@code Conversation}.
- * <p>
- * Note that due to limitations of the {@link Set} interface (specifically, there is no {@code get(T t)} method),
- * we have to resort to a {@link Map} (in which keys map to themselves) to "mimic" a set with {@code get(T t)}
- * functionality.
- *
- * @see <a href="https://stackoverflow.com/questions/7283338/getting-an-element-from-a-set">this question on StackOverflow.com</a>
- */
- private final Map<Conversation, Conversation> mOpenConversations = new HashMap<>();
-
- /**
- * Holds <em>terminated</em> {@link Conversation}s.
- */
- private final List<Conversation> mTerminatedConversations = new ArrayList<>();
-
- @Override
- public void gotPacket(PcapPacket pcapPacket) {
- IpV4Packet ipPacket = pcapPacket.get(IpV4Packet.class);
- TcpPacket tcpPacket = pcapPacket.get(TcpPacket.class);
-
- if (ipPacket == null || tcpPacket == null) {
- return;
- }
- // ... TODO?
- processPacket(pcapPacket);
-// Class clazz = pcapPacket.getClass();
-// RadiotapPacket radiotapPacket = pcapPacket.get(RadiotapPacket.class);
-// Dot11ManagementPacket dot11ManagementPacket = pcapPacket.get(Dot11ManagementPacket.class);
-// if (dot11ManagementPacket != null) {
-// return;
-// }
-// if (radiotapPacket != null) {
-// processRadiotapPacket(pcapPacket);
-// }
- }
-
- /**
- * Get the reassembled TCP connections. Note that if this is called while packets are still being processed (by
- * calls to {@link #gotPacket(PcapPacket)}), the behavior is undefined and the returned list may be inconsistent.
- * @return The reassembled TCP connections.
- */
- public List<Conversation> getTcpConversations() {
- ArrayList<Conversation> combined = new ArrayList<>();
- combined.addAll(mTerminatedConversations);
- combined.addAll(mOpenConversations.values());
- return combined;
- }
-
- private void processRadiotapPacket(PcapPacket pcapPacket) {
- RadiotapPacket radiotapPacket = pcapPacket.get(RadiotapPacket.class);
-
- RadiotapPacket.RadiotapHeader header = radiotapPacket.getHeader();
- short length = header.getLength();
- ArrayList<RadiotapPacket.RadiotapData> radiotapData = header.getDataFields();
- // TODO: We can handle this 802.11 QoS data by creating our own class
- // TODO: We only need to handle the first few bytes for source, destination, receiver, and transmitter
- // TODO: addresses
- Packet dataPacket = radiotapPacket.getPayload();
- int dataLength = dataPacket.length();
- }
-
- private void processPacket(PcapPacket pcapPacket) {
- TcpPacket tcpPacket = pcapPacket.get(TcpPacket.class);
- // Handle client connection initiation attempts.
- if (tcpPacket.getHeader().getSyn() && !tcpPacket.getHeader().getAck()) {
- // A segment with the SYN flag set, but no ACK flag indicates that a client is attempting to initiate a new
- // connection.
- processNewConnectionRequest(pcapPacket);
- return;
- }
- // Handle server connection initiation acknowledgement
- if (tcpPacket.getHeader().getSyn() && tcpPacket.getHeader().getAck()) {
- // A segment with both the SYN and ACK flags set indicates that the server has accepted the client's request
- // to initiate a new connection.
- processNewConnectionAck(pcapPacket);
- return;
- }
- // Handle resets
- if (tcpPacket.getHeader().getRst()) {
- processRstPacket(pcapPacket);
- return;
- }
- // Handle FINs
- if (tcpPacket.getHeader().getFin()) {
- // Handle FIN packet.
- processFinPacket(pcapPacket);
- }
- // Handle ACKs (currently only ACKs of FINS)
- if (tcpPacket.getHeader().getAck()) {
- processAck(pcapPacket);
- }
- // Handle packets that carry payload (application data).
- if (tcpPacket.getPayload() != null) {
- processPayloadPacket(pcapPacket);
- }
- }
-
- private void processNewConnectionRequest(PcapPacket clientSynPacket) {
- // A SYN w/o ACK always originates from the client.
- Conversation conv = Conversation.fromPcapPacket(clientSynPacket, true);
- conv.addSynPacket(clientSynPacket);
- // Is there an ongoing conversation for the same four tuple (clientIp, clientPort, serverIp, serverPort) as
- // found in the new SYN packet?
- Conversation ongoingConv = mOpenConversations.get(conv);
- if (ongoingConv != null) {
- if (ongoingConv.isRetransmission(clientSynPacket)) {
- // SYN retransmission detected, do nothing.
- return;
- // TODO: the way retransmission detection is implemented may cause a bug for connections where we have
- // not recorded the initial SYN, but only the SYN ACK, as retransmission is determined by comparing the
- // sequence numbers of initial SYNs -- and if no initial SYN is present for the Conversation, the new
- // SYN will be interpreted as a retransmission. Possible fix: let isRentransmission ALWAYS return false
- // when presented with a SYN packet when the Conversation already holds a SYN ACK packet?
- } else {
- // New SYN has different sequence number than SYN recorded for ongoingConv, so this must be an attempt
- // to establish a new conversation with the same four tuple as ongoingConv.
- // Mark existing connection as terminated.
- // TODO: is this 100% theoretically correct, e.g., if many connection attempts are made back to back? And RST packets?
- mTerminatedConversations.add(ongoingConv);
- mOpenConversations.remove(ongoingConv);
- }
- }
- // Finally, update the map of open connections with the new connection.
- mOpenConversations.put(conv, conv);
- }
-
-
- /*
- * TODO a problem across the board for all processXPacket methods below:
- * if we start the capture in the middle of a TCP connection, we will not have an entry for the conversation in the
- * map as we have not seen the initial SYN packet.
- * Two ways we can address this:
- * a) Perform null-checks and ignore packets for which we have not seen SYN
- * + easy to get correct
- * - we discard data (issue for long-lived connections!)
- * b) Add a corresponding conversation entry whenever we encounter a packet that does not map to a conversation
- * + we consider all data
- * - not immediately clear if this will introduce bugs (incorrectly mapping packets to wrong conversations?)
- *
- * [[[ I went with option b) for now; see getOngoingConversationOrCreateNew(PcapPacket pcapPacket). ]]]
- */
-
- private void processNewConnectionAck(PcapPacket srvSynPacket) {
- // Find the corresponding ongoing connection, if any (if we start the capture just *after* the initial SYN, no
- // ongoing conversation entry will exist, so it must be created in that case).
-// Conversation conv = mOpenConversations.get(Conversation.fromPcapPacket(srvSynPacket, false));
- Conversation conv = getOngoingConversationOrCreateNew(srvSynPacket);
- // Note: exploits &&'s short-circuit operation: only attempts to add non-retransmissions.
- if (!conv.isRetransmission(srvSynPacket) && !conv.addSynPacket(srvSynPacket)) {
- // For safety/debugging: if NOT a retransmission and add fails,
- // something has gone terribly wrong/invariant is broken.
-// throw new AssertionError("Attempt to add SYN ACK packet that was NOT a retransmission failed." +
-// Conversation.class.getSimpleName() + " invariant broken.");
- }
- }
-
- private void processRstPacket(PcapPacket rstPacket) {
- Conversation conv = getOngoingConversationOrCreateNew(rstPacket);
- // Add RST packet to conversation.
- conv.addRstPacket(rstPacket);
- // Move conversation to set of terminated conversations.
- mTerminatedConversations.add(conv);
- mOpenConversations.remove(conv, conv);
- }
-
- private void processFinPacket(PcapPacket finPacket) {
-// getOngoingConversationForPacket(finPacket).addFinPacket(finPacket);
- getOngoingConversationOrCreateNew(finPacket).addFinPacket(finPacket);
- }
-
- private void processAck(PcapPacket ackPacket) {
-// getOngoingConversationForPacket(ackPacket).attemptAcknowledgementOfFin(ackPacket);
- // Note that unlike the style for SYN, FIN, and payload packets, for "ACK only" packets, we want to avoid
- // creating a new conversation.
- Conversation conv = getOngoingConversationForPacket(ackPacket);
- if (conv != null) {
- // The ACK may be an ACK of a FIN, so attempt to mark the FIN as ack'ed.
- conv.attemptAcknowledgementOfFin(ackPacket);
- if (conv.isGracefullyShutdown()) {
- // Move conversation to set of terminated conversations.
- mTerminatedConversations.add(conv);
- mOpenConversations.remove(conv);
- }
- }
- // Note: add (additional) processing of ACKs (that are not ACKs of FINs) as necessary here...
- }
-
- private void processPayloadPacket(PcapPacket pcapPacket) {
-// getOngoingConversationForPacket(pcapPacket).addPacket(pcapPacket, true);
- getOngoingConversationOrCreateNew(pcapPacket).addPacket(pcapPacket, true);
- }
-
- /**
- * Locates an ongoing conversation (if any) that {@code pcapPacket} pertains to.
- * @param pcapPacket The packet that is to be mapped to an ongoing {@code Conversation}.
- * @return The {@code Conversation} matching {@code pcapPacket} or {@code null} if there is no match.
- */
- private Conversation getOngoingConversationForPacket(PcapPacket pcapPacket) {
- // We cannot know if this is a client-to-server or server-to-client packet without trying both options...
- Conversation conv = mOpenConversations.get(Conversation.fromPcapPacket(pcapPacket, true));
- if (conv == null) {
- conv = mOpenConversations.get(Conversation.fromPcapPacket(pcapPacket, false));
- }
- return conv;
- }
-
- /**
- * Like {@link #getOngoingConversationForPacket(PcapPacket)}, but creates and inserts a new {@code Conversation}
- * into {@link #mOpenConversations} if no open conversation is found (i.e., in the case that
- * {@link #getOngoingConversationForPacket(PcapPacket)} returns {@code null}).
- *
- * @param pcapPacket The packet that is to be mapped to an ongoing {@code Conversation}.
- * @return The existing, ongoing {@code Conversation} matching {@code pcapPacket} or the newly created one in case
- * no match was found.
- */
- private Conversation getOngoingConversationOrCreateNew(PcapPacket pcapPacket) {
- Conversation conv = getOngoingConversationForPacket(pcapPacket);
- if (conv == null) {
- TcpPacket tcpPacket = pcapPacket.get(TcpPacket.class);
- if (tcpPacket.getHeader().getSyn() && tcpPacket.getHeader().getAck()) {
- // A SYN ACK packet always originates from the server (it is a reply to the initial SYN packet from the client)
- conv = Conversation.fromPcapPacket(pcapPacket, false);
- } else {
- // TODO: can we do anything else but arbitrarily select who is designated as the server in this case?
- // We can check if the IP prefix matches a local IP when handling traffic observed inside the local
- // network, but that obviously won't be a useful strategy for an observer at the WAN port.
- String srcIp = pcapPacket.get(IpV4Packet.class).getHeader().getSrcAddr().getHostAddress();
- // TODO: REPLACE THE ROUTER'S IP WITH A PARAMETER!!!
- boolean clientIsSrc = srcIp.startsWith("10.") || srcIp.startsWith("192.168.") || srcIp.equals("128.195.205.105");
- conv = Conversation.fromPcapPacket(pcapPacket, clientIsSrc);
- }
- mOpenConversations.put(conv, conv);
- }
- return conv;
- }
-}
package edu.uci.iotproject.analysis;
-import edu.uci.iotproject.Conversation;
+import edu.uci.iotproject.trafficreassembly.layer3.Conversation;
import edu.uci.iotproject.DnsMap;
import edu.uci.iotproject.util.PcapPacketUtils;
import org.pcap4j.core.PcapPacket;
package edu.uci.iotproject.analysis;
-import edu.uci.iotproject.Conversation;
+import edu.uci.iotproject.trafficreassembly.layer3.Conversation;
import edu.uci.iotproject.DnsMap;
-import edu.uci.iotproject.TcpReassembler;
+import edu.uci.iotproject.trafficreassembly.layer3.TcpReassembler;
import org.pcap4j.core.PacketListener;
import org.pcap4j.core.PcapPacket;
package edu.uci.iotproject.comparison;
-import edu.uci.iotproject.Conversation;
+import edu.uci.iotproject.trafficreassembly.layer3.Conversation;
import edu.uci.iotproject.FlowPattern;
/**
package edu.uci.iotproject.comparison;
-import edu.uci.iotproject.Conversation;
+import edu.uci.iotproject.trafficreassembly.layer3.Conversation;
import edu.uci.iotproject.FlowPattern;
import org.pcap4j.core.PcapPacket;
import org.pcap4j.packet.TcpPacket;
package edu.uci.iotproject.comparison;
-import edu.uci.iotproject.Conversation;
+import edu.uci.iotproject.trafficreassembly.layer3.Conversation;
import edu.uci.iotproject.FlowPattern;
/**
package edu.uci.iotproject.comparison;
-import edu.uci.iotproject.Conversation;
+import edu.uci.iotproject.trafficreassembly.layer3.Conversation;
import edu.uci.iotproject.FlowPattern;
import java.util.concurrent.Callable;
package edu.uci.iotproject.comparison.seqalignment;
-import edu.uci.iotproject.Conversation;
+import edu.uci.iotproject.trafficreassembly.layer3.Conversation;
import org.pcap4j.core.PcapPacket;
import java.util.List;
package edu.uci.iotproject.comparison.seqalignment;
-import edu.uci.iotproject.Conversation;
+import edu.uci.iotproject.trafficreassembly.layer3.Conversation;
import edu.uci.iotproject.analysis.TcpConversationUtils;
-import java.util.Comparator;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
package edu.uci.iotproject.detection;
-import edu.uci.iotproject.Conversation;
import org.pcap4j.core.PcapPacket;
import java.util.List;
package edu.uci.iotproject.detection;
-import edu.uci.iotproject.Conversation;
-import edu.uci.iotproject.TcpReassembler;
+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;
+++ /dev/null
-package edu.uci.iotproject.detection;
-
-import edu.uci.iotproject.L2FlowReassembler;
-import edu.uci.iotproject.Layer2Flow;
-import edu.uci.iotproject.Layer2FlowReassemblerObserver;
-import edu.uci.iotproject.io.PcapHandleReader;
-import edu.uci.iotproject.util.PrintUtils;
-import org.pcap4j.core.*;
-
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-
-/**
- * TODO add class documentation.
- *
- * @author Janus Varmarken
- */
-public class Layer2ClusterMatcher extends AbstractClusterMatcher implements Layer2FlowReassemblerObserver, Layer2FlowObserver {
-
- public static void main(String[] args) throws PcapNativeException, NotOpenException {
- final String onSignatureFile = "/Users/varmarken/temp/UCI IoT Project/experiments/training/signatures/tplink-plug/tplink-plug-onSignature-device-side.sig";
- List<List<List<PcapPacket>>> onSignature = PrintUtils.deserializeSignatureFromFile(onSignatureFile);
-
-
- L2FlowReassembler flowReassembler = new L2FlowReassembler();
-
- Layer2ClusterMatcher l2ClusterMatcher = new Layer2ClusterMatcher(onSignature.get(0));
- flowReassembler.addObserver(l2ClusterMatcher);
-
- final String inputPcapFile = "/Users/varmarken/temp/UCI IoT Project/experiments/2018-07/tplink/tplink.wlan1.local.pcap";
-
- PcapHandle handle;
- try {
- handle = Pcaps.openOffline(inputPcapFile, PcapHandle.TimestampPrecision.NANO);
- } catch (PcapNativeException pne) {
- handle = Pcaps.openOffline(inputPcapFile);
- }
- PcapHandleReader reader = new PcapHandleReader(handle, p -> true, flowReassembler);
- reader.readFromHandle();
-
-
- }
-
-
- private final List<Layer2SequenceMatcher> mSeqMatchers;
-
- public Layer2ClusterMatcher(List<List<PcapPacket>> cluster) {
- super(cluster);
- // Setup a sequence matcher for each sequence of the pruned cluster
- mSeqMatchers = new ArrayList<>();
- mCluster.forEach(seq -> mSeqMatchers.add(new Layer2SequenceMatcher(seq)));
-
-// for (int i = 0; i < mCluster.size(); i++) {
-//
-//
-// mSeqMatchers[i] = new Layer2SequenceMatcher(mCluster.get(i));
-//
-//
-// }
- }
-
-// @Override
-// public void gotPacket(PcapPacket packet) {
-// // Forward the packet to all sequence matchers.
-// for (Layer2SequenceMatcher matcher : mSeqMatchers) {
-// matcher.gotPacket(packet);
-// }
-//
-//
-// }
-
-
- private final Map<Layer2Flow, List<Layer2SequenceMatcher>> mPerFlowSeqMatchers = new HashMap<>();
-
- @Override
- public void onNewPacket(Layer2Flow flow, PcapPacket newPacket) {
- if (mPerFlowSeqMatchers.get(flow) == null) {
- // If this is the first time we encounter this flow, we need to set up sequence matchers for it.
- List<Layer2SequenceMatcher> matchers = new ArrayList<>();
- mCluster.forEach(seq -> matchers.add(new Layer2SequenceMatcher(seq)));
- mPerFlowSeqMatchers.put(flow, matchers);
- }
- // Buffer for new sequence matchers that will take over the job of observing for the first packet when a
- // sequence matcher advances beyond the first packet.
- List<Layer2SequenceMatcher> newSeqMatchers = new ArrayList<>();
- // Buffer for sequence matchers that have terminated and are to be removed from mPerFlowSeqMatchers.
- List<Layer2SequenceMatcher> terminatedSeqMatchers = new ArrayList<>();
- // Present the new packet to all sequence matchers
- for (Layer2SequenceMatcher sm : mPerFlowSeqMatchers.get(flow)) {
- boolean matched = sm.matchPacket(newPacket);
- if (matched && sm.getMatchedPacketsCount() == 1) {
- // Setup a new sequence matcher that matches from the beginning of the sequence so as to keep
- // progressing in the sequence matcher that just matched the current packet, while still allowing
- // for matches of the full sequence in later traffic. This is to accommodate the case where the
- // first packet of a sequence is detected in an early packet, but where the remaining packets of
- // that sequence do not appear until way later in time (e.g., if the first packet of the sequence
- // by chance is generated from traffic unrelated to the trigger traffic).
- // Note that we must store the new sequence matcher in a buffer and add it outside the loop in order to
- // prevent concurrent modification exceptions.
- newSeqMatchers.add(new Layer2SequenceMatcher(sm.getTargetSequence()));
- }
- if (matched && sm.getMatchedPacketsCount() == sm.getTargetSequencePacketCount()) {
- // This sequence matcher has a match of the sequence it was searching for
- // TODO report it.... for now just do a dummy printout.
- System.out.println("SEQUENCE MATCHER HAS A MATCH AT " + sm.getMatchedPackets().get(0).getTimestamp());
- // Mark the sequence matcher for removal. No need to create a replacement one as we do that whenever the
- // first packet of the sequence is matched (see above).
- terminatedSeqMatchers.add(sm);
- }
- }
- // Add the new sequence matchers, if any.
- mPerFlowSeqMatchers.get(flow).addAll(newSeqMatchers);
- // Remove the terminated sequence matchers, if any.
- mPerFlowSeqMatchers.get(flow).removeAll(terminatedSeqMatchers);
- }
-
-
- @Override
- protected List<List<PcapPacket>> pruneCluster(List<List<PcapPacket>> cluster) {
- // Note: we assume that all sequences in the input cluster are of the same length and that their packet
- // directions are identical.
- List<List<PcapPacket>> prunedCluster = new ArrayList<>();
- for (List<PcapPacket> originalClusterSeq : cluster) {
- boolean alreadyPresent = prunedCluster.stream().anyMatch(pcPkts -> {
- for (int i = 0; i < pcPkts.size(); i++) {
- if (pcPkts.get(i).getOriginalLength() != originalClusterSeq.get(i).getOriginalLength()) {
- return false;
- }
- }
- return true;
- });
- if (!alreadyPresent) {
- // Add the sequence if not already present in the pruned cluster.
- prunedCluster.add(originalClusterSeq);
- }
- }
- return prunedCluster;
- }
-
-
- @Override
- public void onNewFlow(L2FlowReassembler reassembler, Layer2Flow newFlow) {
- // Subscribe to the new flow to get updates whenever a new packet pertaining to the flow is processed.
- newFlow.addFlowObserver(this);
- }
-}
package edu.uci.iotproject.detection;
-import edu.uci.iotproject.Layer2Flow;
+import edu.uci.iotproject.trafficreassembly.layer2.Layer2Flow;
import org.pcap4j.core.PcapPacket;
/**
+++ /dev/null
-package edu.uci.iotproject.detection;
-
-import edu.uci.iotproject.analysis.TriggerTrafficExtractor;
-import org.pcap4j.core.PcapPacket;
-
-import java.util.ArrayList;
-import java.util.List;
-
-/**
- * TODO add class documentation.
- *
- * @author Janus Varmarken
- */
-public class Layer2SequenceMatcher {
-
- /**
- * The sequence this {@link Layer2SequenceMatcher} is searching for.
- */
- private final List<PcapPacket> mSequence;
-
- /**
- * Buffer of actual packets seen so far that match the searched sequence (i.e., constitutes a subsequence of the
- * searched sequence).
- */
- private final List<PcapPacket> mMatchedPackets = new ArrayList<>();
-
- public Layer2SequenceMatcher(List<PcapPacket> sequence) {
- mSequence = sequence;
- }
-
- public boolean matchPacket(PcapPacket packet) {
- // The packet we want to match next.
- PcapPacket expected = mSequence.get(mMatchedPackets.size());
- // First verify if the received packet has the length we're looking for.
- if (packet.getOriginalLength() == expected.getOriginalLength()) {
- // Next apply timing constraints:
- // - to be a match, the packet must have a later timestamp than any other packet currently matched
- // - does adding the packet cause the max allowed time between first packet and last packet to be exceeded?
- if (mMatchedPackets.size() > 0 &&
- !packet.getTimestamp().isAfter(mMatchedPackets.get(mMatchedPackets.size()-1).getTimestamp())) {
- return false;
- }
- if (mMatchedPackets.size() > 0 &&
- packet.getTimestamp().
- isAfter(mMatchedPackets.get(0).getTimestamp().
- plusMillis(TriggerTrafficExtractor.INCLUSION_WINDOW_MILLIS))) {
- // Packet too
- return false;
- }
- // TODO (how to) check directions?
- // This packet has a length matching next packet of searched sequence, so we store it and advance.
- mMatchedPackets.add(packet);
- if (mMatchedPackets.size() == mSequence.size()) {
- // TODO report (to observers?) that we are done.
- }
- return true;
- }
- return false;
- }
-
- public int getMatchedPacketsCount() {
- return mMatchedPackets.size();
- }
-
- public int getTargetSequencePacketCount() {
- return mSequence.size();
- }
-
- public List<PcapPacket> getTargetSequence() {
- return mSequence;
- }
-
- public List<PcapPacket> getMatchedPackets() {
- return mMatchedPackets;
- }
-}
--- /dev/null
+package edu.uci.iotproject.detection.layer2;
+
+import edu.uci.iotproject.trafficreassembly.layer2.Layer2FlowReassembler;
+import edu.uci.iotproject.trafficreassembly.layer2.Layer2Flow;
+import edu.uci.iotproject.trafficreassembly.layer2.Layer2FlowReassemblerObserver;
+import edu.uci.iotproject.detection.AbstractClusterMatcher;
+import edu.uci.iotproject.detection.Layer2FlowObserver;
+import edu.uci.iotproject.io.PcapHandleReader;
+import edu.uci.iotproject.util.PrintUtils;
+import org.pcap4j.core.*;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * TODO add class documentation.
+ *
+ * @author Janus Varmarken
+ */
+public class Layer2ClusterMatcher extends AbstractClusterMatcher implements Layer2FlowReassemblerObserver, Layer2FlowObserver {
+
+ public static void main(String[] args) throws PcapNativeException, NotOpenException {
+ final String onSignatureFile = "/Users/varmarken/temp/UCI IoT Project/experiments/training/signatures/tplink-plug/tplink-plug-onSignature-device-side.sig";
+ List<List<List<PcapPacket>>> onSignature = PrintUtils.deserializeSignatureFromFile(onSignatureFile);
+
+
+ Layer2FlowReassembler flowReassembler = new Layer2FlowReassembler();
+
+ Layer2ClusterMatcher l2ClusterMatcher = new Layer2ClusterMatcher(onSignature.get(0));
+ flowReassembler.addObserver(l2ClusterMatcher);
+
+ final String inputPcapFile = "/Users/varmarken/temp/UCI IoT Project/experiments/2018-07/tplink/tplink.wlan1.local.pcap";
+
+ PcapHandle handle;
+ try {
+ handle = Pcaps.openOffline(inputPcapFile, PcapHandle.TimestampPrecision.NANO);
+ } catch (PcapNativeException pne) {
+ handle = Pcaps.openOffline(inputPcapFile);
+ }
+ PcapHandleReader reader = new PcapHandleReader(handle, p -> true, flowReassembler);
+ reader.readFromHandle();
+
+
+ }
+
+
+ private final List<Layer2SequenceMatcher> mSeqMatchers;
+
+ public Layer2ClusterMatcher(List<List<PcapPacket>> cluster) {
+ super(cluster);
+ // Setup a sequence matcher for each sequence of the pruned cluster
+ mSeqMatchers = new ArrayList<>();
+ mCluster.forEach(seq -> mSeqMatchers.add(new Layer2SequenceMatcher(seq)));
+
+// for (int i = 0; i < mCluster.size(); i++) {
+//
+//
+// mSeqMatchers[i] = new Layer2SequenceMatcher(mCluster.get(i));
+//
+//
+// }
+ }
+
+// @Override
+// public void gotPacket(PcapPacket packet) {
+// // Forward the packet to all sequence matchers.
+// for (Layer2SequenceMatcher matcher : mSeqMatchers) {
+// matcher.gotPacket(packet);
+// }
+//
+//
+// }
+
+
+ private final Map<Layer2Flow, List<Layer2SequenceMatcher>> mPerFlowSeqMatchers = new HashMap<>();
+
+ @Override
+ public void onNewPacket(Layer2Flow flow, PcapPacket newPacket) {
+ if (mPerFlowSeqMatchers.get(flow) == null) {
+ // If this is the first time we encounter this flow, we need to set up sequence matchers for it.
+ List<Layer2SequenceMatcher> matchers = new ArrayList<>();
+ mCluster.forEach(seq -> matchers.add(new Layer2SequenceMatcher(seq)));
+ mPerFlowSeqMatchers.put(flow, matchers);
+ }
+ // Buffer for new sequence matchers that will take over the job of observing for the first packet when a
+ // sequence matcher advances beyond the first packet.
+ List<Layer2SequenceMatcher> newSeqMatchers = new ArrayList<>();
+ // Buffer for sequence matchers that have terminated and are to be removed from mPerFlowSeqMatchers.
+ List<Layer2SequenceMatcher> terminatedSeqMatchers = new ArrayList<>();
+ // Present the new packet to all sequence matchers
+ for (Layer2SequenceMatcher sm : mPerFlowSeqMatchers.get(flow)) {
+ boolean matched = sm.matchPacket(newPacket);
+ if (matched && sm.getMatchedPacketsCount() == 1) {
+ // Setup a new sequence matcher that matches from the beginning of the sequence so as to keep
+ // progressing in the sequence matcher that just matched the current packet, while still allowing
+ // for matches of the full sequence in later traffic. This is to accommodate the case where the
+ // first packet of a sequence is detected in an early packet, but where the remaining packets of
+ // that sequence do not appear until way later in time (e.g., if the first packet of the sequence
+ // by chance is generated from traffic unrelated to the trigger traffic).
+ // Note that we must store the new sequence matcher in a buffer and add it outside the loop in order to
+ // prevent concurrent modification exceptions.
+ newSeqMatchers.add(new Layer2SequenceMatcher(sm.getTargetSequence()));
+ }
+ if (matched && sm.getMatchedPacketsCount() == sm.getTargetSequencePacketCount()) {
+ // This sequence matcher has a match of the sequence it was searching for
+ // TODO report it.... for now just do a dummy printout.
+ System.out.println("SEQUENCE MATCHER HAS A MATCH AT " + sm.getMatchedPackets().get(0).getTimestamp());
+ // Mark the sequence matcher for removal. No need to create a replacement one as we do that whenever the
+ // first packet of the sequence is matched (see above).
+ terminatedSeqMatchers.add(sm);
+ }
+ }
+ // Add the new sequence matchers, if any.
+ mPerFlowSeqMatchers.get(flow).addAll(newSeqMatchers);
+ // Remove the terminated sequence matchers, if any.
+ mPerFlowSeqMatchers.get(flow).removeAll(terminatedSeqMatchers);
+ }
+
+
+ @Override
+ protected List<List<PcapPacket>> pruneCluster(List<List<PcapPacket>> cluster) {
+ // Note: we assume that all sequences in the input cluster are of the same length and that their packet
+ // directions are identical.
+ List<List<PcapPacket>> prunedCluster = new ArrayList<>();
+ for (List<PcapPacket> originalClusterSeq : cluster) {
+ boolean alreadyPresent = prunedCluster.stream().anyMatch(pcPkts -> {
+ for (int i = 0; i < pcPkts.size(); i++) {
+ if (pcPkts.get(i).getOriginalLength() != originalClusterSeq.get(i).getOriginalLength()) {
+ return false;
+ }
+ }
+ return true;
+ });
+ if (!alreadyPresent) {
+ // Add the sequence if not already present in the pruned cluster.
+ prunedCluster.add(originalClusterSeq);
+ }
+ }
+ return prunedCluster;
+ }
+
+
+ @Override
+ public void onNewFlow(Layer2FlowReassembler reassembler, Layer2Flow newFlow) {
+ // Subscribe to the new flow to get updates whenever a new packet pertaining to the flow is processed.
+ newFlow.addFlowObserver(this);
+ }
+}
--- /dev/null
+package edu.uci.iotproject.detection.layer2;
+
+import edu.uci.iotproject.analysis.TriggerTrafficExtractor;
+import org.pcap4j.core.PcapPacket;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * TODO add class documentation.
+ *
+ * @author Janus Varmarken
+ */
+public class Layer2SequenceMatcher {
+
+ /**
+ * The sequence this {@link Layer2SequenceMatcher} is searching for.
+ */
+ private final List<PcapPacket> mSequence;
+
+ /**
+ * Buffer of actual packets seen so far that match the searched sequence (i.e., constitutes a subsequence of the
+ * searched sequence).
+ */
+ private final List<PcapPacket> mMatchedPackets = new ArrayList<>();
+
+ public Layer2SequenceMatcher(List<PcapPacket> sequence) {
+ mSequence = sequence;
+ }
+
+ public boolean matchPacket(PcapPacket packet) {
+ // The packet we want to match next.
+ PcapPacket expected = mSequence.get(mMatchedPackets.size());
+ // First verify if the received packet has the length we're looking for.
+ if (packet.getOriginalLength() == expected.getOriginalLength()) {
+ // Next apply timing constraints:
+ // - to be a match, the packet must have a later timestamp than any other packet currently matched
+ // - does adding the packet cause the max allowed time between first packet and last packet to be exceeded?
+ if (mMatchedPackets.size() > 0 &&
+ !packet.getTimestamp().isAfter(mMatchedPackets.get(mMatchedPackets.size()-1).getTimestamp())) {
+ return false;
+ }
+ if (mMatchedPackets.size() > 0 &&
+ packet.getTimestamp().
+ isAfter(mMatchedPackets.get(0).getTimestamp().
+ plusMillis(TriggerTrafficExtractor.INCLUSION_WINDOW_MILLIS))) {
+ // Packet too
+ return false;
+ }
+ // TODO (how to) check directions?
+ // This packet has a length matching next packet of searched sequence, so we store it and advance.
+ mMatchedPackets.add(packet);
+ if (mMatchedPackets.size() == mSequence.size()) {
+ // TODO report (to observers?) that we are done.
+ }
+ return true;
+ }
+ return false;
+ }
+
+ public int getMatchedPacketsCount() {
+ return mMatchedPackets.size();
+ }
+
+ public int getTargetSequencePacketCount() {
+ return mSequence.size();
+ }
+
+ public List<PcapPacket> getTargetSequence() {
+ return mSequence;
+ }
+
+ public List<PcapPacket> getMatchedPackets() {
+ return mMatchedPackets;
+ }
+}
package edu.uci.iotproject.evaluation;
-import edu.uci.iotproject.Conversation;
-import edu.uci.iotproject.TcpReassembler;
+import edu.uci.iotproject.trafficreassembly.layer3.Conversation;
+import edu.uci.iotproject.trafficreassembly.layer3.TcpReassembler;
import edu.uci.iotproject.io.PcapHandleReader;
import edu.uci.iotproject.util.PrintUtils;
import org.pcap4j.core.*;
--- /dev/null
+package edu.uci.iotproject.trafficreassembly.layer2;
+
+import edu.uci.iotproject.detection.Layer2FlowObserver;
+import org.pcap4j.core.PcapPacket;
+import org.pcap4j.packet.EthernetPacket;
+import org.pcap4j.util.MacAddress;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * The packets exchanged between two endpoints (MAC addresses).
+ *
+ * @author Janus Varmarken
+ */
+public class Layer2Flow {
+
+ private final MacAddress mEndpoint1;
+ private final MacAddress mEndpoint2;
+
+ private final List<Layer2FlowObserver> mFlowObservers = new ArrayList<>();
+
+ public Layer2Flow(MacAddress endpoint1, MacAddress endpoint2) {
+ mEndpoint1 = endpoint1;
+ mEndpoint2 = endpoint2;
+ }
+
+ public void addFlowObserver(Layer2FlowObserver observer) {
+ mFlowObservers.add(observer);
+ }
+
+ public void removeFlowObserver(Layer2FlowObserver observer) {
+ mFlowObservers.remove(observer);
+ }
+
+ /**
+ * The packets in the flow.
+ */
+ private final List<PcapPacket> mPackets = new ArrayList<>();
+
+ /**
+ * Add a packet to this flow.
+ * @param packet The packet that is to be added to the flow.
+ */
+ public void addPacket(PcapPacket packet) {
+ verifyAddresses(packet);
+ mPackets.add(packet);
+ // Notify flow observers of the new packet
+ mFlowObservers.forEach(o -> o.onNewPacket(this, packet));
+ }
+
+ public List<PcapPacket> getPackets() {
+ return Collections.unmodifiableList(mPackets);
+ }
+
+ private void verifyAddresses(PcapPacket packet) {
+ EthernetPacket ethPkt = packet.get(EthernetPacket.class);
+ MacAddress srcAddr = ethPkt.getHeader().getSrcAddr();
+ MacAddress dstAddr = ethPkt.getHeader().getDstAddr();
+ if ((mEndpoint1.equals(srcAddr) && mEndpoint2.equals(dstAddr)) ||
+ (mEndpoint1.equals(dstAddr) && mEndpoint2.equals(srcAddr))) {
+ // All is good.
+ return;
+ }
+ throw new IllegalArgumentException("Mismatch in MACs: packet does not pertain to this flow");
+ }
+
+}
+
+
+
+/*
+
+
+ Packet stream -> flow reassembler -> flow1, flow2, flow3... -> for each flow, keep a sequence matcher for each sequence of cluster
+
+
+ */
\ No newline at end of file
--- /dev/null
+package edu.uci.iotproject.trafficreassembly.layer2;
+
+import edu.uci.iotproject.trafficreassembly.layer2.Layer2Flow;
+import edu.uci.iotproject.trafficreassembly.layer2.Layer2FlowReassemblerObserver;
+import org.pcap4j.core.PacketListener;
+import org.pcap4j.core.PcapPacket;
+import org.pcap4j.packet.EthernetPacket;
+import org.pcap4j.util.MacAddress;
+
+import java.util.*;
+
+/**
+ * Reassembles traffic flows at layer 2, i.e., for each combination of hosts, creates a list of packets exchanged
+ * between said hosts.
+ *
+ * @author Janus Varmarken {@literal <jvarmark@uci.edu>}
+ * @author Rahmadi Trimananda {@literal <rtrimana@uci.edu>}
+ */
+public class Layer2FlowReassembler implements PacketListener {
+
+ /**
+ * Maps a pair of MAC addresses to the packets exchanged between the two hosts.
+ * The key is the concatenation of the two MAC addresses in hex string format, where the lexicographically smaller
+ * MAC is at the front of the string.
+ */
+ private final Map<String, Layer2Flow> mFlows = new HashMap<>();
+
+ private final List<Layer2FlowReassemblerObserver> mObservers = new ArrayList<>();
+
+ @Override
+ public void gotPacket(PcapPacket packet) {
+ // TODO: update to 802.11 packet...?
+ EthernetPacket ethPkt = packet.get(EthernetPacket.class);
+
+ MacAddress srcAddr = ethPkt.getHeader().getSrcAddr();
+ MacAddress dstAddr = ethPkt.getHeader().getDstAddr();
+
+ String key = keyFromAddresses(srcAddr, dstAddr);
+ // Create a new list if this pair of MAC addresses where not previously encountered and add packet to that list,
+ // or simply add to an existing list if one is present.
+ mFlows.computeIfAbsent(key, k -> {
+ Layer2Flow newFlow = new Layer2Flow(srcAddr, dstAddr);
+ // Inform observers of the new flow
+ mObservers.forEach(o -> o.onNewFlow(this, newFlow));
+ return newFlow;
+ }).addPacket(packet);
+ }
+
+ public void addObserver(Layer2FlowReassemblerObserver observer) {
+ mObservers.add(observer);
+ }
+
+ public void removeObserver(Layer2FlowReassemblerObserver observer) {
+ mObservers.remove(observer);
+ }
+
+ /**
+ * Get the traffic flow between two local endpoints ({@link MacAddress}es).
+ * @param addr1 The first endpoint.
+ * @param addr2 The second endpoint
+ * @return The traffic exchanged between the two endpoints.
+ */
+ public Layer2Flow getFlowForAddresses(MacAddress addr1, MacAddress addr2) {
+ return mFlows.get(keyFromAddresses(addr1, addr2));
+ }
+
+ /**
+ * Get all traffic flows, i.e., a traffic flow for each unique pair of endpoints (MAC addresses).
+ * @return All traffic flows.
+ */
+ public Collection<Layer2Flow> getFlows() {
+ return mFlows.values();
+ }
+
+ /**
+ * Given two {@link MacAddress}es, generates the corresponding key string used in {@link #mFlows}.
+ * @param addr1 The first address.
+ * @param addr2 The second address.
+ * @return the key string used in {@link #mFlows} corresponding to the two addresses.
+ */
+ private String keyFromAddresses(MacAddress addr1, MacAddress addr2) {
+ String addr1Str = addr1.toString();
+ String addr2Str = addr2.toString();
+ return addr1Str.compareTo(addr2Str) < 0 ? addr1Str + addr2Str : addr2Str + addr1Str;
+ }
+}
--- /dev/null
+package edu.uci.iotproject.trafficreassembly.layer2;
+
+/**
+ * For observing a {@link Layer2FlowReassembler}.
+ *
+ * @author Janus Varmarken
+ */
+public interface Layer2FlowReassemblerObserver {
+
+ /**
+ * Invoked when when a {@link Layer2FlowReassembler} detects a new flow (i.e., when it encounters traffic between two
+ * MAC addresses that has not previously communicated in the traffic trace).
+ *
+ * @param reassembler The {@link Layer2FlowReassembler} that detected the new flow.
+ * @param newFlow The new flow.
+ */
+ void onNewFlow(Layer2FlowReassembler reassembler, Layer2Flow newFlow);
+
+}
--- /dev/null
+package edu.uci.iotproject.trafficreassembly.layer3;
+
+import edu.uci.iotproject.analysis.TcpConversationUtils;
+import edu.uci.iotproject.util.PcapPacketUtils;
+import org.pcap4j.core.PcapPacket;
+import org.pcap4j.packet.IpV4Packet;
+import org.pcap4j.packet.Packet;
+import org.pcap4j.packet.TcpPacket;
+
+import java.util.*;
+
+/**
+ * Models a (TCP) conversation/connection/session/flow (packet's belonging to the same session between a client and a
+ * server).
+ * Holds a list of {@link PcapPacket}s identified as pertaining to the flow. Note that this list is <em>not</em>
+ * considered when determining equality of two {@code Conversation} instances in order to allow for a
+ * {@code Conversation} to function as a key in data structures such as {@link java.util.Map} and {@link java.util.Set}.
+ * See {@link #equals(Object)} for the definition of equality.
+ *
+ * @author Janus Varmarken {@literal <jvarmark@uci.edu>}
+ * @author Rahmadi Trimananda {@literal <rtrimana@uci.edu>}
+ */
+public class Conversation {
+
+ /* Begin instance properties */
+ /**
+ * The IP of the host that is considered the client (i.e. the host that initiates the conversation)
+ * in this conversation.
+ */
+ private final String mClientIp;
+
+ /**
+ * The port number used by the host that is considered the client in this conversation.
+ */
+ private final int mClientPort;
+
+ /**
+ * The IP of the host that is considered the server (i.e. is the responder) in this conversation.
+ */
+ private final String mServerIp;
+
+ /**
+ * The port number used by the server in this conversation.
+ */
+ private final int mServerPort;
+
+ /**
+ * The list of packets (with payload) pertaining to this conversation.
+ */
+ private final List<PcapPacket> mPackets;
+
+ /**
+ * If {@link #isTls()} is {@code true}, this list contains the subset of {@link #mPackets} which are TLS Application
+ * Data packets.
+ */
+ private final List<PcapPacket> mTlsApplicationDataPackets;
+
+ /**
+ * Contains the sequence numbers used thus far by the host that is considered the <em>client</em> in this
+ * {@code Conversation}.
+ * Used for filtering out retransmissions.
+ */
+ private final Set<Integer> mSeqNumbersClient;
+
+ /**
+ * Contains the sequence numbers used thus far by the host that is considered the <em>server</em> in this
+ * {@code Conversation}.
+ * Used for filtering out retransmissions.
+ */
+ private final Set<Integer> mSeqNumbersSrv;
+
+ /**
+ * List of SYN packets pertaining to this conversation.
+ */
+ private final List<PcapPacket> mSynPackets;
+
+ /**
+ * List of pairs FINs and their corresponding ACKs associated with this conversation.
+ */
+ private final List<FinAckPair> mFinPackets;
+
+ /**
+ * List of RST packets associated with this conversation.
+ */
+ private final List<PcapPacket> mRstPackets;
+
+ /**
+ * Boolean to mark the packet as Application Data based on the previous packet that reaches MTU
+ */
+ private boolean mApplicationData;
+ /* End instance properties */
+
+ /**
+ * Factory method for creating a {@code Conversation} from a {@link PcapPacket}.
+ * @param pcapPacket The {@code PcapPacket} that wraps a TCP segment for which a {@code Conversation} is to be initiated.
+ * @param clientIsSrc If {@code true}, the source address and source port found in the IP datagram and TCP segment
+ * wrapped in the {@code PcapPacket} are regarded as pertaining to the client, and the destination
+ * address and destination port are regarded as pertaining to the server---and vice versa if set
+ * to {@code false}.
+ * @return A {@code Conversation} initiated with ip:port for client and server according to the direction of the packet.
+ */
+ public static Conversation fromPcapPacket(PcapPacket pcapPacket, boolean clientIsSrc) {
+ IpV4Packet ipPacket = pcapPacket.get(IpV4Packet.class);
+ TcpPacket tcpPacket = pcapPacket.get(TcpPacket.class);
+ String clientIp = clientIsSrc ? ipPacket.getHeader().getSrcAddr().getHostAddress() :
+ ipPacket.getHeader().getDstAddr().getHostAddress();
+ String srvIp = clientIsSrc ? ipPacket.getHeader().getDstAddr().getHostAddress() :
+ ipPacket.getHeader().getSrcAddr().getHostAddress();
+ int clientPort = clientIsSrc ? tcpPacket.getHeader().getSrcPort().valueAsInt() :
+ tcpPacket.getHeader().getDstPort().valueAsInt();
+ int srvPort = clientIsSrc ? tcpPacket.getHeader().getDstPort().valueAsInt() :
+ tcpPacket.getHeader().getSrcPort().valueAsInt();
+ return new Conversation(clientIp, clientPort, srvIp, srvPort);
+ }
+
+ /**
+ * Constructs a new {@code Conversation}.
+ * @param clientIp The IP of the host that is considered the client (i.e. the host that initiates the conversation)
+ * in the conversation.
+ * @param clientPort The port number used by the client for the conversation.
+ * @param serverIp The IP of the host that is considered the server (i.e. is the responder) in the conversation.
+ * @param serverPort The port number used by the server for the conversation.
+ */
+ public Conversation(String clientIp, int clientPort, String serverIp, int serverPort) {
+ this.mClientIp = clientIp;
+ this.mClientPort = clientPort;
+ this.mServerIp = serverIp;
+ this.mServerPort = serverPort;
+ this.mPackets = new ArrayList<>();
+ this.mTlsApplicationDataPackets = new ArrayList<>();
+ this.mSeqNumbersClient = new HashSet<>();
+ this.mSeqNumbersSrv = new HashSet<>();
+ this.mSynPackets = new ArrayList<>();
+ this.mFinPackets = new ArrayList<>();
+ this.mRstPackets = new ArrayList<>();
+ this.mApplicationData = false;
+ }
+
+ /**
+ * Add a packet to the list of packets associated with this conversation.
+ * @param packet The packet that is to be added to (associated with) this conversation.
+ * @param ignoreRetransmissions Boolean value indicating if retransmissions should be ignored.
+ * If set to {@code true}, {@code packet} will <em>not</em> be added to the
+ * internal list of packets pertaining to this {@code Conversation}
+ * <em>iff</em> the sequence number of {@code packet} was already
+ * seen in a previous packet.
+ */
+ public void addPacket(PcapPacket packet, boolean ignoreRetransmissions) {
+ // Precondition: verify that packet does indeed pertain to conversation.
+ onAddPrecondition(packet);
+ if (ignoreRetransmissions && isRetransmission(packet)) {
+ // Packet is a retransmission. Ignore it.
+ return;
+ }
+ // Select direction-dependent set of sequence numbers seen so far and update it with sequence number of new packet.
+ addSeqNumber(packet);
+ // Finally add packet to list of packets pertaining to this conversation.
+ mPackets.add(packet);
+ // Preserve order of packets in list: sort according to timestamp.
+ if (mPackets.size() > 1 &&
+ mPackets.get(mPackets.size()-1).getTimestamp().isBefore(mPackets.get(mPackets.size()-2).getTimestamp())) {
+ Collections.sort(mPackets, (o1, o2) -> {
+ if (o1.getTimestamp().isBefore(o2.getTimestamp())) { return -1; }
+ else if (o2.getTimestamp().isBefore(o1.getTimestamp())) { return 1; }
+ else { return 0; }
+ });
+ }
+ // If TLS, inspect packet to see if it's a TLS Application Data packet, and if so add it to the list of TLS
+ // Application Data packets.
+ if (isTls()) {
+ TcpPacket tcpPacket = packet.get(TcpPacket.class);
+ Packet tcpPayload = tcpPacket.getPayload();
+ if (tcpPayload == null) {
+ return;
+ }
+ byte[] rawPayload = tcpPayload.getRawData();
+ // The SSL record header is at the front of the payload and is 5 bytes long.
+ // The SSL record header type field (the first byte) is set to 23 if it is an Application Data packet.
+ if (rawPayload != null && rawPayload.length >= 5) {
+ if (rawPayload[0] == 23) {
+ mTlsApplicationDataPackets.add(packet);
+ // Consider the following packet a data packet if this packet's size == MTU size 1448
+ if (rawPayload.length >= 1448)
+ mApplicationData = true;
+ } else if (rawPayload[0] == 20) {
+ // Do nothing for now - CHANGE_CIPHER_SPEC
+ } else if (rawPayload[0] == 21) {
+ // Do nothing for now - ALERT
+ } else if (rawPayload[0] == 22) {
+ // Do nothing for now - HANDSHAKE
+ } else {
+ // If it is TLS with payload, but rawPayload[0] != 23
+ if (mApplicationData == true) {
+ // It is a continuation of the previous packet if the previous packet reaches MTU size 1448 and
+ // it is not either type 20, 21, or 22
+ mTlsApplicationDataPackets.add(packet);
+ if (rawPayload.length < 1448)
+ mApplicationData = false;
+ }
+ }
+ }
+ }
+ }
+
+ /**
+ * Get a list of packets pertaining to this {@code Conversation}.
+ * The returned list is a read-only list.
+ * @return the list of packets pertaining to this {@code Conversation}.
+ */
+ public List<PcapPacket> getPackets() {
+ // Return read-only view to prevent external code from manipulating internal state (preserve invariant).
+ return Collections.unmodifiableList(mPackets);
+ }
+
+ /**
+ * Records a TCP SYN packet as pertaining to this conversation (adds it to the the internal list).
+ * Attempts to add duplicate SYN packets will be ignored, and the caller is made aware of the attempt to add a
+ * duplicate by the return value being {@code false}.
+ *
+ * @param synPacket A {@link PcapPacket} wrapping a TCP SYN packet.
+ * @return {@code true} if the packet was successfully added to this {@code Conversation}, {@code false} otherwise.
+ */
+ public boolean addSynPacket(PcapPacket synPacket) {
+ onAddPrecondition(synPacket);
+ final IpV4Packet synPacketIpSection = synPacket.get(IpV4Packet.class);
+ final TcpPacket synPacketTcpSection = synPacket.get(TcpPacket.class);
+ if (synPacketTcpSection == null || !synPacketTcpSection.getHeader().getSyn()) {
+ throw new IllegalArgumentException("Not a SYN packet.");
+ }
+ // We are only interested in recording one copy of the two SYN packets (one SYN packet in each direction), i.e.,
+ // we want to discard retransmitted SYN packets.
+ if (mSynPackets.size() >= 2) {
+ return false;
+ }
+ // Check the set of recorded SYN packets to see if we have already recorded a SYN packet going in the same
+ // direction as the packet given in the argument.
+ boolean matchingPrevSyn = mSynPackets.stream().anyMatch(p -> {
+ IpV4Packet pIp = p.get(IpV4Packet.class);
+ TcpPacket pTcp = p.get(TcpPacket.class);
+ boolean srcAddrMatch = synPacketIpSection.getHeader().getSrcAddr().getHostAddress().
+ equals(pIp.getHeader().getSrcAddr().getHostAddress());
+ boolean dstAddrMatch = synPacketIpSection.getHeader().getDstAddr().getHostAddress().
+ equals(pIp.getHeader().getDstAddr().getHostAddress());
+ boolean srcPortMatch = synPacketTcpSection.getHeader().getSrcPort().valueAsInt() ==
+ pTcp.getHeader().getSrcPort().valueAsInt();
+ boolean dstPortMatch = synPacketTcpSection.getHeader().getDstPort().valueAsInt() ==
+ pTcp.getHeader().getDstPort().valueAsInt();
+ return srcAddrMatch && dstAddrMatch && srcPortMatch && dstPortMatch;
+ });
+ if (matchingPrevSyn) {
+ return false;
+ }
+ // Update direction-dependent set of sequence numbers and record/log packet.
+ addSeqNumber(synPacket);
+ return mSynPackets.add(synPacket);
+
+ /*
+ mSynPackets.stream().anyMatch(p -> {
+ IpV4Packet pIp = p.get(IpV4Packet.class);
+ TcpPacket pTcp = p.get(TcpPacket.class);
+ boolean srcAddrMatch = synPacketIpSection.getHeader().getSrcAddr().getHostAddress().
+ equals(pIp.getHeader().getSrcAddr().getHostAddress());
+ boolean dstAddrMatch = synPacketIpSection.getHeader().getDstAddr().getHostAddress().
+ equals(pIp.getHeader().getDstAddr().getHostAddress());
+ boolean srcPortMatch = synPacketTcpSection.getHeader().getSrcPort().valueAsInt() ==
+ pTcp.getHeader().getSrcPort().valueAsInt();
+ boolean dstPortMatch = synPacketTcpSection.getHeader().getDstPort().value() ==
+ pTcp.getHeader().getDstPort().value();
+
+ boolean fourTupleMatch = srcAddrMatch && dstAddrMatch && srcPortMatch && dstPortMatch;
+
+ boolean seqNoMatch = synPacketTcpSection.getHeader().getSequenceNumber() ==
+ pTcp.getHeader().getSequenceNumber();
+
+ if (fourTupleMatch && !seqNoMatch) {
+ // If the four tuple that identifies the conversation matches, but the sequence number is different,
+ // it means that this SYN packet is, in fact, an attempt to establish a **new** connection, and hence
+ // the given packet is NOT part of this conversation, even though the ip:port combinations are (by
+ // chance) selected such that they match this conversation.
+ throw new IllegalArgumentException("Attempt to add SYN packet that belongs to a different conversation " +
+ "(which is identified by the same four tuple as this conversation)");
+ }
+ return fourTupleMatch && seqNoMatch;
+ });
+ */
+ }
+
+ /**
+ * Get a list of SYN packets pertaining to this {@code Conversation}.
+ * The returned list is a read-only list.
+ * @return the list of SYN packets pertaining to this {@code Conversation}.
+ */
+ public List<PcapPacket> getSynPackets() {
+ return Collections.unmodifiableList(mSynPackets);
+ }
+
+ /**
+ * Adds a TCP FIN packet to the list of TCP FIN packets associated with this conversation.
+ * @param finPacket The TCP FIN packet that is to be added to (associated with) this conversation.
+ */
+ public void addFinPacket(PcapPacket finPacket) {
+ // Precondition: verify that packet does indeed pertain to conversation.
+ onAddPrecondition(finPacket);
+ // TODO: should call addSeqNumber here?
+ addSeqNumber(finPacket);
+ mFinPackets.add(new FinAckPair(finPacket));
+ }
+
+ /**
+ * Attempt to ACK any FIN packets held by this conversation.
+ * @param ackPacket The ACK for a FIN previously added to this conversation.
+ */
+ public void attemptAcknowledgementOfFin(PcapPacket ackPacket) {
+ // Precondition: verify that the packet pertains to this conversation.
+ onAddPrecondition(ackPacket);
+ // Mark unack'ed FIN(s) that this ACK matches as ACK'ed (there might be more than one in case of retransmissions..?)
+ mFinPackets.replaceAll(finAckPair -> !finAckPair.isAcknowledged() && finAckPair.isCorrespondingAckPacket(ackPacket) ? new FinAckPair(finAckPair.getFinPacket(), ackPacket) : finAckPair);
+ }
+
+ /**
+ * Retrieves an unmodifiable view of the list of {@link FinAckPair}s associated with this {@code Conversation}.
+ * @return an unmodifiable view of the list of {@link FinAckPair}s associated with this {@code Conversation}.
+ */
+ public List<FinAckPair> getFinAckPairs() {
+ return Collections.unmodifiableList(mFinPackets);
+ }
+
+ /**
+ * Get if this {@code Conversation} is considered to have been gracefully shut down.
+ * A {@code Conversation} has been gracefully shut down if it contains a FIN+ACK pair for both directions
+ * (client to server, and server to client).
+ * @return {@code true} if the connection has been gracefully shut down, false otherwise.
+ */
+ public boolean isGracefullyShutdown() {
+ // The conversation has been gracefully shut down if we have recorded a FIN from both the client and the server which have both been ack'ed.
+ return mFinPackets.stream().anyMatch(finAckPair -> finAckPair.isAcknowledged() && PcapPacketUtils.isSource(finAckPair.getFinPacket(), mClientIp, mClientPort)) &&
+ mFinPackets.stream().anyMatch(finAckPair -> finAckPair.isAcknowledged() && PcapPacketUtils.isSource(finAckPair.getFinPacket(), mServerIp, mServerPort));
+ }
+
+ /**
+ * Add a TCP segment for which the RST flag is set to this {@code Conversation}.
+ * @param packet A {@link PcapPacket} wrapping a TCP segment pertaining to this {@code Conversation} for which the
+ * RST flag is set.
+ */
+ public void addRstPacket(PcapPacket packet) {
+ /*
+ * TODO:
+ * When now also keeping track of RST packets, should we also...?
+ * 1) Prevent later packets from being added once a RST segment has been added?
+ * 2) Extend 'isGracefullyShutdown()' to also consider RST segments, or add another method, 'isShutdown()' that
+ * both considers FIN/ACK (graceful) as well as RST (abrupt/"ungraceful") shutdown?
+ * 3) Should it be impossible to associate more than one RST segment with each Conversation?
+ */
+ onAddPrecondition(packet);
+ TcpPacket tcpPacket = packet.get(TcpPacket.class);
+ if (tcpPacket == null || !tcpPacket.getHeader().getRst()) {
+ throw new IllegalArgumentException("not a RST packet");
+ }
+ mRstPackets.add(packet);
+ }
+
+ /**
+ * Get the TCP segments pertaining to this {@code Conversation} for which it was detected that the RST flag is set.
+ * @return the TCP segments pertaining to this {@code Conversation} for which it was detected that the RST flag is
+ * set.
+ */
+ public List<PcapPacket> getRstPackets() {
+ return Collections.unmodifiableList(mRstPackets);
+ }
+
+ // =========================================================================================================
+ // We simply reuse equals and hashCode methods of String.class to be able to use this class as a key
+ // in a Map.
+
+ /**
+ * <em>Note:</em> currently, equality is determined based on pairwise equality of the elements of the four tuple
+ * ({@link #mClientIp}, {@link #mClientPort}, {@link #mServerIp}, {@link #mServerPort}) for {@code this} and
+ * {@code obj}.
+ * @param obj The object to test for equality with {@code this}.
+ * @return {@code true} if {@code obj} is considered equal to {@code this} based on the definition of equality given above.
+ */
+ @Override
+ public boolean equals(Object obj) {
+ return obj instanceof Conversation && this.toString().equals(obj.toString());
+ }
+
+ @Override
+ public int hashCode() {
+ return toString().hashCode();
+ }
+ // =========================================================================================================
+
+ @Override
+ public String toString() {
+ return String.format("%s:%d %s:%d", mClientIp, mClientPort, mServerIp, mServerPort);
+ }
+
+ /**
+ * Invoke to verify that the precondition holds when a caller attempts to add a packet to this {@code Conversation}.
+ * An {@link IllegalArgumentException} is thrown if the precondition is violated.
+ * @param packet the packet to be added to this {@code Conversation}
+ */
+ private void onAddPrecondition(PcapPacket packet) {
+ // Apply precondition to preserve class invariant: all packets in mPackets must match the 4 tuple that
+ // defines the conversation.
+ IpV4Packet ipPacket = Objects.requireNonNull(packet.get(IpV4Packet.class));
+ // For now we only support TCP flows.
+ TcpPacket tcpPacket = Objects.requireNonNull(packet.get(TcpPacket.class));
+ String ipSrc = ipPacket.getHeader().getSrcAddr().getHostAddress();
+ String ipDst = ipPacket.getHeader().getDstAddr().getHostAddress();
+ int srcPort = tcpPacket.getHeader().getSrcPort().valueAsInt();
+ int dstPort = tcpPacket.getHeader().getDstPort().valueAsInt();
+ String clientIp, serverIp;
+ int clientPort, serverPort;
+ if (ipSrc.equals(mClientIp)) {
+ clientIp = ipSrc;
+ clientPort = srcPort;
+ serverIp = ipDst;
+ serverPort = dstPort;
+ } else {
+ clientIp = ipDst;
+ clientPort = dstPort;
+ serverIp = ipSrc;
+ serverPort = srcPort;
+ }
+ if (!(clientIp.equals(mClientIp) && clientPort == mClientPort &&
+ serverIp.equals(mServerIp) && serverPort == mServerPort)) {
+ throw new IllegalArgumentException(
+ String.format("Attempt to add packet that does not pertain to %s",
+ Conversation.class.getSimpleName()));
+ }
+ }
+
+ /**
+ * <p>
+ * Determines if the TCP packet contained in {@code packet} is a retransmission of a previously seen (logged)
+ * packet.
+ * </p>
+ *
+ * <b>
+ * TODO:
+ * the current implementation, which uses a set of previously seen sequence numbers, will consider a segment
+ * with a reused sequence number---occurring as a result of sequence number wrap around for a very long-lived
+ * connection---as a retransmission (and may therefore end up discarding it even though it is in fact NOT a
+ * retransmission). Ideas?
+ * </b>
+ *
+ * @param packet The packet.
+ * @return {@code true} if {@code packet} was determined to be a retransmission, {@code false} otherwise.
+ */
+ public boolean isRetransmission(PcapPacket packet) {
+ // Extract sequence number.
+ int seqNo = packet.get(TcpPacket.class).getHeader().getSequenceNumber();
+ switch (getDirection(packet)) {
+ case CLIENT_TO_SERVER:
+ return mSeqNumbersClient.contains(seqNo);
+ case SERVER_TO_CLIENT:
+ return mSeqNumbersSrv.contains(seqNo);
+ default:
+ throw new AssertionError(String.format("Unexpected value of enum '%s'",
+ Direction.class.getSimpleName()));
+ }
+ }
+
+ /**
+ * <p>
+ * Is this {@code Conversation} a TLS session?
+ * </p>
+ *
+ * <em>Note: the current implementation simply examines the port number(s) for 443; it does <b>not</b> verify if the
+ * application data is indeed encrypted.</em>
+ *
+ * @return {@code true} if this {@code Conversation} is interpreted as a TLS session, {@code false} otherwise.
+ */
+ public boolean isTls() {
+ /*
+ * TODO:
+ * - may want to change this to be "return mServerPort == 443 || mClientPort == 443;" in order to also detect
+ * TLS in those cases where it is not possible to correctly label who is the client and who is the server,
+ * i.e., when the trace does not contain the SYN/SYNACK exchange.
+ * - current implementation relies on the server using the conventional TLS port number; may instead want to
+ * inspect the first 4 bytes of each potential TLS packet to see if they match the SSL record header.
+ *
+ * 08/31/18: Added unconvetional TLS ports used by WeMo plugs and LiFX bulb.
+ * 09/20/18: Moved hardcoded ports to other class to allow other classes to query the set of TLS ports.
+ */
+ return TcpConversationUtils.isTlsPort(mServerPort);
+ }
+
+ /**
+ * If this {@code Conversation} is backing a TLS session (i.e., if the value of {@link #isTls()} is {@code true}),
+ * get the packets labeled as TLS Application Data packets. This is a subset of the full set of payload-carrying
+ * packets (as returned by {@link #getPackets()}). An exception is thrown if this method is invoked on a
+ * {@code Conversation} for which {@link #isTls()} returns {@code false}.
+ *
+ * @return A list containing exactly those packets that could be identified as TLS Application Data packets (through
+ * inspecting of the SSL record header). The list may be empty, if no TLS application data packets have been
+ * recorded for this {@code Conversation}.
+ */
+ public List<PcapPacket> getTlsApplicationDataPackets() {
+ if (!isTls()) {
+ throw new NoSuchElementException("cannot get TLS Application Data packets for non-TLS TCP conversation");
+ }
+ return Collections.unmodifiableList(mTlsApplicationDataPackets);
+ }
+
+ /**
+ * Extracts the TCP sequence number from {@code packet} and adds it to the proper set of sequence numbers by
+ * analyzing the direction of the packet.
+ * @param packet A TCP packet (wrapped in a {@code PcapPacket}) that was added to this conversation and whose
+ * sequence number is to be recorded as seen.
+ */
+ private void addSeqNumber(PcapPacket packet) {
+ // Note: below check is redundant if client code is correct as the call to check the precondition should already
+ // have been made by the addXPacket method that invokes this method. As such, the call below may be removed in
+ // favor of speed, but the improvement will be minor, hence the added safety may be worth it.
+ onAddPrecondition(packet);
+ // Extract sequence number.
+ int seqNo = packet.get(TcpPacket.class).getHeader().getSequenceNumber();
+ // Determine direction of packet and add packet's sequence number to corresponding set of sequence numbers.
+ switch (getDirection(packet)) {
+ case CLIENT_TO_SERVER:
+ // Client to server packet.
+ mSeqNumbersClient.add(seqNo);
+ break;
+ case SERVER_TO_CLIENT:
+ // Server to client packet.
+ mSeqNumbersSrv.add(seqNo);
+ break;
+ default:
+ throw new AssertionError(String.format("Unexpected value of enum '%s'",
+ Direction.class.getSimpleName()));
+ }
+ }
+
+ /**
+ * Determine the direction of {@code packet}. An {@link IllegalArgumentException} is thrown if {@code packet} does
+ * not pertain to this conversation.
+ *
+ * @param packet The packet whose direction is to be determined.
+ * @return A {@link Direction} indicating the direction of the packet.
+ */
+ public Direction getDirection(PcapPacket packet) {
+ IpV4Packet ipPacket = packet.get(IpV4Packet.class);
+ String ipSrc = ipPacket.getHeader().getSrcAddr().getHostAddress();
+ String ipDst = ipPacket.getHeader().getDstAddr().getHostAddress();
+ // Determine direction of packet.
+ if (ipSrc.equals(mClientIp) && ipDst.equals(mServerIp)) {
+ // Client to server packet.
+ return Direction.CLIENT_TO_SERVER;
+ } else if (ipSrc.equals(mServerIp) && ipDst.equals(mClientIp)) {
+ // Server to client packet.
+ return Direction.SERVER_TO_CLIENT;
+ } else {
+ throw new IllegalArgumentException("getDirection: packet not related to " + getClass().getSimpleName());
+ }
+ }
+
+ /**
+ * Utility enum for expressing the direction of a packet pertaining to this {@code Conversation}.
+ */
+ public enum Direction {
+
+ CLIENT_TO_SERVER {
+ @Override
+ public String toCompactString() {
+ return "*";
+ }
+ },
+ SERVER_TO_CLIENT {
+ @Override
+ public String toCompactString() {
+ return "";
+ }
+ };
+
+ /**
+ * Get a compact string representation of this {@code Direction}.
+ * @return a compact string representation of this {@code Direction}.
+ */
+ abstract public String toCompactString();
+
+ }
+
+}
--- /dev/null
+package edu.uci.iotproject.trafficreassembly.layer3;
+
+import org.pcap4j.core.PcapPacket;
+import org.pcap4j.packet.IpV4Packet;
+import org.pcap4j.packet.TcpPacket;
+
+/**
+ * Groups a FIN packet and its corresponding ACK packet. <b>Immutable and thread safe</b>.
+ *
+ * @author Janus Varmarken {@literal <jvarmark@uci.edu>}
+ * @author Rahmadi Trimananda {@literal <rtrimana@uci.edu>}
+ */
+public class FinAckPair {
+
+ private final PcapPacket mFinPacket;
+ private final PcapPacket mCorrespondingAckPacket;
+
+ /**
+ * Constructs a {@code FinAckPair} given a FIN packet.
+ * The corresponding ACK packet field is set to {@code null}.
+ * @param finPacket A FIN packet.
+ */
+ public FinAckPair(PcapPacket finPacket) {
+ if (!finPacket.get(TcpPacket.class).getHeader().getFin()) {
+ throw new IllegalArgumentException("not a FIN packet");
+ }
+ mFinPacket = finPacket;
+ mCorrespondingAckPacket = null;
+ }
+
+ /**
+ * Constructs a {@code FinAckPair} given a FIN and an ACK packet.
+ * @param finPacket A FIN packet.
+ * @param correspondingAckPacket The ACK packet corresponding to {@code finPacket}.
+ */
+ public FinAckPair(PcapPacket finPacket, PcapPacket correspondingAckPacket) {
+ // Enforce class invariant, i.e. that the FIN and ACK are related.
+ // Note that it is indirectly checked whether finPacket is indeed a FIN packet
+ // as isCorrespondingAckPacket calls the single parameter constructor.
+ if (!FinAckPair.isCorrespondingAckPacket(finPacket, correspondingAckPacket)) {
+ throw new IllegalArgumentException("FIN and ACK not related");
+ }
+ mFinPacket = finPacket;
+ mCorrespondingAckPacket = correspondingAckPacket;
+ }
+
+ /**
+ * Get the FIN packet of this pair.
+ * @return the FIN packet of this pair.
+ */
+ public PcapPacket getFinPacket() {
+ return mFinPacket;
+ }
+
+ /**
+ * Get the corresponding ACK packet of this pair, if any.
+ * @return the corresponding ACK packet of this pair, if any.
+ */
+ public PcapPacket getCorrespondingAckPacket() {
+ return mCorrespondingAckPacket;
+ }
+
+ /**
+ * Was the FIN in this {@code FinAckPair} acknowledged?
+ *
+ * @return {@code true} if the corresponding ACK has been set in this {@code FinAckPair}.
+ */
+ public boolean isAcknowledged() {
+ return mFinPacket != null && mCorrespondingAckPacket != null;
+ }
+
+ /**
+ * Checks if a given packet is an ACK corresponding to the FIN packet in this {@code FinAckPair}.
+ * @return {@code true} if {@code packet} is an ACK that corresponds to the FIN in this pair, {@code false} otherwise.
+ */
+ public boolean isCorrespondingAckPacket(PcapPacket packet) {
+ IpV4Packet inputIpPacket = packet.get(IpV4Packet.class);
+ TcpPacket inputTcpPacket = packet.get(TcpPacket.class);
+ if (inputIpPacket == null || inputTcpPacket == null || !inputTcpPacket.getHeader().getAck()) {
+ return false;
+ }
+
+ IpV4Packet finIpPacket = mFinPacket.get(IpV4Packet.class);
+ TcpPacket finTcpPacket = mFinPacket.get(TcpPacket.class);
+
+ // Extract (srcIp:port,dstIp:port) for input and member (FIN) packets.
+ String inputPacketIpSrc = inputIpPacket.getHeader().getSrcAddr().getHostAddress();
+ String inputPacketIpDst = inputIpPacket.getHeader().getDstAddr().getHostAddress();
+ int inputPacketPortSrc = inputTcpPacket.getHeader().getSrcPort().valueAsInt();
+ int inputPacketPortDst = inputTcpPacket.getHeader().getDstPort().valueAsInt();
+ String finPacketIpSrc = finIpPacket.getHeader().getSrcAddr().getHostAddress();
+ String finPacketIpDst = finIpPacket.getHeader().getDstAddr().getHostAddress();
+ int finPacketPortSrc = finTcpPacket.getHeader().getSrcPort().valueAsInt();
+ int finPacketPortDst = finTcpPacket.getHeader().getDstPort().valueAsInt();
+
+ // For the two packets to be related, the dst of one must be the src of the other.
+ // Split into multiple if statements for readability. First check IP fields, then ports.
+ if (!(inputPacketIpDst.equals(finPacketIpSrc) && finPacketIpDst.equals(inputPacketIpSrc))) {
+ return false;
+ }
+ if (!(inputPacketPortDst == finPacketPortSrc && finPacketPortDst == inputPacketPortSrc)) {
+ return false;
+ }
+
+ // Packets are (most likely) related (part of same conversation/stream).
+ // Now all that is left for us to check is if the sequence numbers match.
+ // Note: recall that the FIN packet advances the seq numbers by 1,
+ // so the ACK number will be one larger than the seq. number in the FIN packet.
+ return inputTcpPacket.getHeader().getAcknowledgmentNumber() == finTcpPacket.getHeader().getSequenceNumber() + 1;
+ }
+
+ /**
+ * Static method to check if two given packets are a FIN and the corresponding ACK packet.
+ * The purpose of this method is a workaround to enforce the class invariant in the two parameter constructor.
+ * Specifically, the following should be avoided:
+ * <pre>
+ * public FinAckPair(PcapPacket finPacket, PcapPacket correspondingAckPacket) {
+ * mFinPacket = finPacket;
+ * // Below line is considered bad practice as the object has not been fully initialized at this stage.
+ * if (!this.isCorrespondingAckPacket(correspondingAckPacket)) {
+ * // ... throw exception
+ * }
+ * }
+ * </pre>
+ * @param finPacket The FIN packet.
+ * @param ackPacket The ACK packet that is to be checked if it corresponds to the given FIN packet.
+ * @return {@code true} if the ACK corresponds to the FIN, {@code false} otherwise.
+ */
+ private static boolean isCorrespondingAckPacket(PcapPacket finPacket, PcapPacket ackPacket) {
+ FinAckPair tmp = new FinAckPair(finPacket);
+ return tmp.isCorrespondingAckPacket(ackPacket);
+ }
+
+}
--- /dev/null
+package edu.uci.iotproject.trafficreassembly.layer3;
+
+import org.pcap4j.core.PacketListener;
+import org.pcap4j.core.PcapPacket;
+import org.pcap4j.packet.*;
+
+import java.util.*;
+
+/**
+ * Reassembles TCP conversations (streams).
+ * <b>Note: current version only supports TCP over IPv4.</b>
+ *
+ * @author Janus Varmarken {@literal <jvarmark@uci.edu>}
+ * @author Rahmadi Trimananda {@literal <rtrimana@uci.edu>}
+ */
+public class TcpReassembler implements PacketListener {
+
+ /**
+ * Holds <em>open</em> {@link Conversation}s, i.e., {@code Conversation}s that have <em>not</em> been detected as
+ * (gracefully) terminated based on the set of packets observed thus far.
+ * A {@link Conversation} is moved to {@link #mTerminatedConversations} if it can be determined that it is has
+ * terminated. Termination can be detected by a) observing two {@link FinAckPair}s, one in each direction, (graceful
+ * termination, see {@link Conversation#isGracefullyShutdown()}) or b) by observing a SYN packet that matches the
+ * four tuple of an existing {@code Conversation}, but which holds a <em>different</em> sequence number than the
+ * same-direction SYN packet recorded for the {@code Conversation}.
+ * <p>
+ * Note that due to limitations of the {@link Set} interface (specifically, there is no {@code get(T t)} method),
+ * we have to resort to a {@link Map} (in which keys map to themselves) to "mimic" a set with {@code get(T t)}
+ * functionality.
+ *
+ * @see <a href="https://stackoverflow.com/questions/7283338/getting-an-element-from-a-set">this question on StackOverflow.com</a>
+ */
+ private final Map<Conversation, Conversation> mOpenConversations = new HashMap<>();
+
+ /**
+ * Holds <em>terminated</em> {@link Conversation}s.
+ */
+ private final List<Conversation> mTerminatedConversations = new ArrayList<>();
+
+ @Override
+ public void gotPacket(PcapPacket pcapPacket) {
+ IpV4Packet ipPacket = pcapPacket.get(IpV4Packet.class);
+ TcpPacket tcpPacket = pcapPacket.get(TcpPacket.class);
+
+ if (ipPacket == null || tcpPacket == null) {
+ return;
+ }
+ // ... TODO?
+ processPacket(pcapPacket);
+// Class clazz = pcapPacket.getClass();
+// RadiotapPacket radiotapPacket = pcapPacket.get(RadiotapPacket.class);
+// Dot11ManagementPacket dot11ManagementPacket = pcapPacket.get(Dot11ManagementPacket.class);
+// if (dot11ManagementPacket != null) {
+// return;
+// }
+// if (radiotapPacket != null) {
+// processRadiotapPacket(pcapPacket);
+// }
+ }
+
+ /**
+ * Get the reassembled TCP connections. Note that if this is called while packets are still being processed (by
+ * calls to {@link #gotPacket(PcapPacket)}), the behavior is undefined and the returned list may be inconsistent.
+ * @return The reassembled TCP connections.
+ */
+ public List<Conversation> getTcpConversations() {
+ ArrayList<Conversation> combined = new ArrayList<>();
+ combined.addAll(mTerminatedConversations);
+ combined.addAll(mOpenConversations.values());
+ return combined;
+ }
+
+ private void processRadiotapPacket(PcapPacket pcapPacket) {
+ RadiotapPacket radiotapPacket = pcapPacket.get(RadiotapPacket.class);
+
+ RadiotapPacket.RadiotapHeader header = radiotapPacket.getHeader();
+ short length = header.getLength();
+ ArrayList<RadiotapPacket.RadiotapData> radiotapData = header.getDataFields();
+ // TODO: We can handle this 802.11 QoS data by creating our own class
+ // TODO: We only need to handle the first few bytes for source, destination, receiver, and transmitter
+ // TODO: addresses
+ Packet dataPacket = radiotapPacket.getPayload();
+ int dataLength = dataPacket.length();
+ }
+
+ private void processPacket(PcapPacket pcapPacket) {
+ TcpPacket tcpPacket = pcapPacket.get(TcpPacket.class);
+ // Handle client connection initiation attempts.
+ if (tcpPacket.getHeader().getSyn() && !tcpPacket.getHeader().getAck()) {
+ // A segment with the SYN flag set, but no ACK flag indicates that a client is attempting to initiate a new
+ // connection.
+ processNewConnectionRequest(pcapPacket);
+ return;
+ }
+ // Handle server connection initiation acknowledgement
+ if (tcpPacket.getHeader().getSyn() && tcpPacket.getHeader().getAck()) {
+ // A segment with both the SYN and ACK flags set indicates that the server has accepted the client's request
+ // to initiate a new connection.
+ processNewConnectionAck(pcapPacket);
+ return;
+ }
+ // Handle resets
+ if (tcpPacket.getHeader().getRst()) {
+ processRstPacket(pcapPacket);
+ return;
+ }
+ // Handle FINs
+ if (tcpPacket.getHeader().getFin()) {
+ // Handle FIN packet.
+ processFinPacket(pcapPacket);
+ }
+ // Handle ACKs (currently only ACKs of FINS)
+ if (tcpPacket.getHeader().getAck()) {
+ processAck(pcapPacket);
+ }
+ // Handle packets that carry payload (application data).
+ if (tcpPacket.getPayload() != null) {
+ processPayloadPacket(pcapPacket);
+ }
+ }
+
+ private void processNewConnectionRequest(PcapPacket clientSynPacket) {
+ // A SYN w/o ACK always originates from the client.
+ Conversation conv = Conversation.fromPcapPacket(clientSynPacket, true);
+ conv.addSynPacket(clientSynPacket);
+ // Is there an ongoing conversation for the same four tuple (clientIp, clientPort, serverIp, serverPort) as
+ // found in the new SYN packet?
+ Conversation ongoingConv = mOpenConversations.get(conv);
+ if (ongoingConv != null) {
+ if (ongoingConv.isRetransmission(clientSynPacket)) {
+ // SYN retransmission detected, do nothing.
+ return;
+ // TODO: the way retransmission detection is implemented may cause a bug for connections where we have
+ // not recorded the initial SYN, but only the SYN ACK, as retransmission is determined by comparing the
+ // sequence numbers of initial SYNs -- and if no initial SYN is present for the Conversation, the new
+ // SYN will be interpreted as a retransmission. Possible fix: let isRentransmission ALWAYS return false
+ // when presented with a SYN packet when the Conversation already holds a SYN ACK packet?
+ } else {
+ // New SYN has different sequence number than SYN recorded for ongoingConv, so this must be an attempt
+ // to establish a new conversation with the same four tuple as ongoingConv.
+ // Mark existing connection as terminated.
+ // TODO: is this 100% theoretically correct, e.g., if many connection attempts are made back to back? And RST packets?
+ mTerminatedConversations.add(ongoingConv);
+ mOpenConversations.remove(ongoingConv);
+ }
+ }
+ // Finally, update the map of open connections with the new connection.
+ mOpenConversations.put(conv, conv);
+ }
+
+
+ /*
+ * TODO a problem across the board for all processXPacket methods below:
+ * if we start the capture in the middle of a TCP connection, we will not have an entry for the conversation in the
+ * map as we have not seen the initial SYN packet.
+ * Two ways we can address this:
+ * a) Perform null-checks and ignore packets for which we have not seen SYN
+ * + easy to get correct
+ * - we discard data (issue for long-lived connections!)
+ * b) Add a corresponding conversation entry whenever we encounter a packet that does not map to a conversation
+ * + we consider all data
+ * - not immediately clear if this will introduce bugs (incorrectly mapping packets to wrong conversations?)
+ *
+ * [[[ I went with option b) for now; see getOngoingConversationOrCreateNew(PcapPacket pcapPacket). ]]]
+ */
+
+ private void processNewConnectionAck(PcapPacket srvSynPacket) {
+ // Find the corresponding ongoing connection, if any (if we start the capture just *after* the initial SYN, no
+ // ongoing conversation entry will exist, so it must be created in that case).
+// Conversation conv = mOpenConversations.get(Conversation.fromPcapPacket(srvSynPacket, false));
+ Conversation conv = getOngoingConversationOrCreateNew(srvSynPacket);
+ // Note: exploits &&'s short-circuit operation: only attempts to add non-retransmissions.
+ if (!conv.isRetransmission(srvSynPacket) && !conv.addSynPacket(srvSynPacket)) {
+ // For safety/debugging: if NOT a retransmission and add fails,
+ // something has gone terribly wrong/invariant is broken.
+// throw new AssertionError("Attempt to add SYN ACK packet that was NOT a retransmission failed." +
+// Conversation.class.getSimpleName() + " invariant broken.");
+ }
+ }
+
+ private void processRstPacket(PcapPacket rstPacket) {
+ Conversation conv = getOngoingConversationOrCreateNew(rstPacket);
+ // Add RST packet to conversation.
+ conv.addRstPacket(rstPacket);
+ // Move conversation to set of terminated conversations.
+ mTerminatedConversations.add(conv);
+ mOpenConversations.remove(conv, conv);
+ }
+
+ private void processFinPacket(PcapPacket finPacket) {
+// getOngoingConversationForPacket(finPacket).addFinPacket(finPacket);
+ getOngoingConversationOrCreateNew(finPacket).addFinPacket(finPacket);
+ }
+
+ private void processAck(PcapPacket ackPacket) {
+// getOngoingConversationForPacket(ackPacket).attemptAcknowledgementOfFin(ackPacket);
+ // Note that unlike the style for SYN, FIN, and payload packets, for "ACK only" packets, we want to avoid
+ // creating a new conversation.
+ Conversation conv = getOngoingConversationForPacket(ackPacket);
+ if (conv != null) {
+ // The ACK may be an ACK of a FIN, so attempt to mark the FIN as ack'ed.
+ conv.attemptAcknowledgementOfFin(ackPacket);
+ if (conv.isGracefullyShutdown()) {
+ // Move conversation to set of terminated conversations.
+ mTerminatedConversations.add(conv);
+ mOpenConversations.remove(conv);
+ }
+ }
+ // Note: add (additional) processing of ACKs (that are not ACKs of FINs) as necessary here...
+ }
+
+ private void processPayloadPacket(PcapPacket pcapPacket) {
+// getOngoingConversationForPacket(pcapPacket).addPacket(pcapPacket, true);
+ getOngoingConversationOrCreateNew(pcapPacket).addPacket(pcapPacket, true);
+ }
+
+ /**
+ * Locates an ongoing conversation (if any) that {@code pcapPacket} pertains to.
+ * @param pcapPacket The packet that is to be mapped to an ongoing {@code Conversation}.
+ * @return The {@code Conversation} matching {@code pcapPacket} or {@code null} if there is no match.
+ */
+ private Conversation getOngoingConversationForPacket(PcapPacket pcapPacket) {
+ // We cannot know if this is a client-to-server or server-to-client packet without trying both options...
+ Conversation conv = mOpenConversations.get(Conversation.fromPcapPacket(pcapPacket, true));
+ if (conv == null) {
+ conv = mOpenConversations.get(Conversation.fromPcapPacket(pcapPacket, false));
+ }
+ return conv;
+ }
+
+ /**
+ * Like {@link #getOngoingConversationForPacket(PcapPacket)}, but creates and inserts a new {@code Conversation}
+ * into {@link #mOpenConversations} if no open conversation is found (i.e., in the case that
+ * {@link #getOngoingConversationForPacket(PcapPacket)} returns {@code null}).
+ *
+ * @param pcapPacket The packet that is to be mapped to an ongoing {@code Conversation}.
+ * @return The existing, ongoing {@code Conversation} matching {@code pcapPacket} or the newly created one in case
+ * no match was found.
+ */
+ private Conversation getOngoingConversationOrCreateNew(PcapPacket pcapPacket) {
+ Conversation conv = getOngoingConversationForPacket(pcapPacket);
+ if (conv == null) {
+ TcpPacket tcpPacket = pcapPacket.get(TcpPacket.class);
+ if (tcpPacket.getHeader().getSyn() && tcpPacket.getHeader().getAck()) {
+ // A SYN ACK packet always originates from the server (it is a reply to the initial SYN packet from the client)
+ conv = Conversation.fromPcapPacket(pcapPacket, false);
+ } else {
+ // TODO: can we do anything else but arbitrarily select who is designated as the server in this case?
+ // We can check if the IP prefix matches a local IP when handling traffic observed inside the local
+ // network, but that obviously won't be a useful strategy for an observer at the WAN port.
+ String srcIp = pcapPacket.get(IpV4Packet.class).getHeader().getSrcAddr().getHostAddress();
+ // TODO: REPLACE THE ROUTER'S IP WITH A PARAMETER!!!
+ boolean clientIsSrc = srcIp.startsWith("10.") || srcIp.startsWith("192.168.") || srcIp.equals("128.195.205.105");
+ conv = Conversation.fromPcapPacket(pcapPacket, clientIsSrc);
+ }
+ mOpenConversations.put(conv, conv);
+ }
+ return conv;
+ }
+}
package edu.uci.iotproject.util;
-import edu.uci.iotproject.Conversation;
+import edu.uci.iotproject.trafficreassembly.layer3.Conversation;
import edu.uci.iotproject.analysis.PcapPacketPair;
import edu.uci.iotproject.analysis.TcpConversationUtils;
import edu.uci.iotproject.analysis.TriggerTrafficExtractor;
projects / pingpong.git / commitdiff