Added support for extracting packet pairs of only TLS Application Data packets (see...

[pingpong.git] / Code / Projects / SmartPlugDetector / src / main / java / edu / uci / iotproject / TcpReassembler.java

diff --git a/Code/Projects/SmartPlugDetector/src/main/java/edu/uci/iotproject/TcpReassembler.java b/Code/Projects/SmartPlugDetector/src/main/java/edu/uci/iotproject/TcpReassembler.java
index 6cce343cc168deffb8b275fe169b29081458182b..c61223de295a8962efe74fc8a7c9a1769449e194 100644 (file)
--- a/Code/Projects/SmartPlugDetector/src/main/java/edu/uci/iotproject/TcpReassembler.java
+++ b/Code/Projects/SmartPlugDetector/src/main/java/edu/uci/iotproject/TcpReassembler.java
@@ -2,6 +2,7 @@ package edu.uci.iotproject;
 
 import org.pcap4j.core.PacketListener;
 import org.pcap4j.core.PcapPacket;
+import org.pcap4j.packet.IpV4Packet;
 import org.pcap4j.packet.TcpPacket;
 
 import java.util.*;
@@ -33,9 +34,8 @@ public class TcpReassembler implements PacketListener {
 
     /**
      * Holds <em>terminated</em> {@link Conversation}s.
-     * TODO: Should turn this into a list to avoid unintentional overwrite of a Conversation in case ephemeral port number is reused at a later stage...?
      */
-    private final Map<Conversation, Conversation> mTerminatedConversations = new HashMap<>();
+    private final List<Conversation> mTerminatedConversations = new ArrayList<>();
 
     @Override
     public void gotPacket(PcapPacket pcapPacket) {
@@ -54,7 +54,7 @@ public class TcpReassembler implements PacketListener {
      */
     public List<Conversation> getTcpConversations() {
         ArrayList<Conversation> combined = new ArrayList<>();
-        combined.addAll(mTerminatedConversations.values());
+        combined.addAll(mTerminatedConversations);
         combined.addAll(mOpenConversations.values());
         return combined;
     }
@@ -116,7 +116,7 @@ public class TcpReassembler implements PacketListener {
                 // 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.put(ongoingConv, ongoingConv);
+                mTerminatedConversations.add(ongoingConv);
                 mOpenConversations.remove(ongoingConv);
             }
         }
@@ -149,15 +149,17 @@ public class TcpReassembler implements PacketListener {
         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 IllegalStateException("Attempt to add SYN ACK packet that was NOT a retransmission failed." +
+            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.put(conv, conv);
+        mTerminatedConversations.add(conv);
         mOpenConversations.remove(conv, conv);
     }
 
@@ -176,7 +178,7 @@ public class TcpReassembler implements PacketListener {
             conv.attemptAcknowledgementOfFin(ackPacket);
             if (conv.isGracefullyShutdown()) {
                 // Move conversation to set of terminated conversations.
-                mTerminatedConversations.put(conv, conv);
+                mTerminatedConversations.add(conv);
                 mOpenConversations.remove(conv);
             }
         }
@@ -220,7 +222,11 @@ public class TcpReassembler implements PacketListener {
                 conv = Conversation.fromPcapPacket(pcapPacket, false);
             } else {
                 // TODO: can we do anything else but arbitrarily select who is designated as the server in this case?
-                conv = Conversation.fromPcapPacket(pcapPacket, false);
+                // 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();
+                boolean clientIsSrc = srcIp.startsWith("10.0.1.") || srcIp.startsWith("192.168.1.");
+                conv = Conversation.fromPcapPacket(pcapPacket, clientIsSrc);
             }
             mOpenConversations.put(conv, conv);
         }