Extract Conversation to separate file (i.e. it is no longer an inner class). Add...

diff --git a/Code/Projects/SmartPlugDetector/src/main/java/edu/uci/iotproject/Conversation.java b/Code/Projects/SmartPlugDetector/src/main/java/edu/uci/iotproject/Conversation.java
new file mode 100644 (file)
index 0000000..f8ee398
--- /dev/null
+++ b/Code/Projects/SmartPlugDetector/src/main/java/edu/uci/iotproject/Conversation.java
@@ -0,0 +1,107 @@
+package edu.uci.iotproject;
+
+import org.pcap4j.core.PcapPacket;
+import org.pcap4j.packet.IpV4Packet;
+import org.pcap4j.packet.TcpPacket;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
+
+/**
+ * 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.
+ */
+public class Conversation {
+
+    private final String mClientIp;
+    private final int mClientPort;
+    private final String mServerIp;
+    private final int mServerPort;
+    private final List<PcapPacket> mPackets;
+
+    /**
+     * 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<>();
+    }
+
+    /**
+     * 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.
+     */
+    public void addPacket(PcapPacket packet) {
+        // Apply precondition to preserve class invariant: all packets in mPackets must match the 4 tuple that
+        // defines the conversation.
+        // ==== Precondition: verify that packet does indeed pertain to 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()));
+        }
+        // ================================================================================
+        mPackets.add(packet);
+    }
+
+    // =========================================================================================================
+    // 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);
+    }
+}
\ No newline at end of file

diff --git a/Code/Projects/SmartPlugDetector/src/main/java/edu/uci/iotproject/FlowPatternFinder.java b/Code/Projects/SmartPlugDetector/src/main/java/edu/uci/iotproject/FlowPatternFinder.java
index aff4534865c2f4d3dc696d2efe624eff1709808d..9bbd99ce985a329270ab12cdef38d01b68350240 100644 (file)
--- a/Code/Projects/SmartPlugDetector/src/main/java/edu/uci/iotproject/FlowPatternFinder.java
+++ b/Code/Projects/SmartPlugDetector/src/main/java/edu/uci/iotproject/FlowPatternFinder.java
@@ -178,44 +178,4 @@ public class FlowPatternFinder {
         }
     }
 
-
-    /**
-     * Immutable class used for identifying a conversation/connection/session/flow (packet's belonging to the same
-     * session between a client and a server).
-     */
-    private static class Conversation {
-
-        private final String clientIp;
-        private final int clientPort;
-        private final String serverIp;
-        private final int serverPort;
-
-        public Conversation(String clientIp, int clientPort, String serverIp, int serverPort) {
-            this.clientIp = clientIp;
-            this.clientPort = clientPort;
-            this.serverIp = serverIp;
-            this.serverPort = serverPort;
-        }
-
-
-        // =========================================================================================================
-        // We simply reuse equals and hashCode methods of String.class to be able to use this immutable class as a key
-        // in a Map.
-        @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", clientIp, clientPort, serverIp, serverPort);
-        }
-    }
-
 }