*/
public class TcpConversationUtils {
+ /**
+ * Identifies the adjacency type of the signature for merging.
+ */
+ public enum SignaturePosition {
+ NOT_ADJACENT,
+ LEFT_ADJACENT,
+ RIGHT_ADJACENT
+ }
+
/**
* <p>
* Given a {@link Conversation}, extract its set of "packet pairs", i.e., pairs of request-reply packets.
sb.append(" ");
}
}
+
+ /**
+ * Given a list of {@link Conversation} objects, sort them by timestamps.
+ * @param conversations The list of {@link Conversation} objects to be sorted.
+ * @return A sorted list of {@code Conversation} based on timestamps of the first
+ * packet in the {@code Conversation}.
+ */
+ public static List<Conversation> sortConversationList(List<Conversation> conversations) {
+ // Get rid of Conversation objects with no packets
+ conversations.removeIf(x -> x.getPackets().size() == 0);
+ // Sort the list based on the first packet's timestamp!
+ Collections.sort(conversations, (c1, c2) ->
+ c1.getPackets().get(0).getTimestamp().compareTo(c2.getPackets().get(0).getTimestamp()));
+ return conversations;
+ }
+
+ /**
+ * Given a {@code List} of {@link Conversation} objects, find one that has the given {@code List}
+ * of {@code PcapPacket}.
+ * @param conversations The {@code List} of {@link Conversation} objects as reference.
+ * @param ppList The {@code List} of {@code PcapPacket} objects to search in the {@code List} of {@link Conversation}.
+ * @return A {@code Conversation} that contains the given {@code List} of {@code PcapPacket}.
+ */
+ public static Conversation returnConversation(List<PcapPacket> ppList, List<Conversation> conversations) {
+ // TODO: This part of comparison takes into account that the list of conversations is not sorted
+ // TODO: We could optimize this to have a better performance by requiring a sorted-by-timestamp list
+ // TODO: as a parameter
+ // Find a Conversation that ppList is part of
+ for (Conversation c : conversations) {
+ // Figure out if c is the Conversation that ppList is in
+ if (isPartOfConversation(ppList, c)) {
+ return c;
+ }
+ }
+ // Return null if not found
+ return null;
+ }
+
+ /**
+ * Given a {@link Conversation} objects, check if {@code List} of {@code PcapPacket} is part of it and return the
+ * adjacency label based on {@code SignaturePosition}.
+ * @param conversation The {@link Conversation} object as reference.
+ * @param ppListFirst The first {@code List} of {@code PcapPacket} objects in the {@link Conversation}.
+ * @param ppListSecond The second {@code List} of {@code PcapPacket} objects in the {@link Conversation} whose
+ * position will be observed in the {@link Conversation} with respect to ppListFirst.
+ * @return A {@code SignaturePosition} that represents the position of the signature against another signature
+ * in a {@link Conversation}.
+ */
+ public static SignaturePosition isPartOfConversationAndAdjacent(List<PcapPacket> ppListFirst,
+ List<PcapPacket> ppListSecond,
+ Conversation conversation) {
+ for (PcapPacket pp : conversation.getPackets()) {
+ // Take the first element in ppList and compare it
+ // The following elements in ppList are guaranteed to be in the same Conversation
+ // TODO: This part of comparison takes into account that the list of conversations is not sorted
+ // TODO: We could optimize this to have a better performance by requiring a sorted-by-timestamp list
+ // TODO: as a parameter
+ if (isPartOfConversation(ppListSecond, conversation)) {
+ // Compare the first element of ppListSecond with the last element of ppListFirst to know
+ // whether ppListSecond is RIGHT_ADJACENT relative to ppListFirst
+ PcapPacket lastElOfFirstList = ppListFirst.get(ppListFirst.size() - 1);
+ PcapPacket firstElOfSecondList = ppListSecond.get(0);
+ // If the positions of the two are in order, then they are adjacent
+ int indexOfLastElOfFirstList = returnIndexInConversation(lastElOfFirstList, conversation);
+ int indexOfFirstElOfSecondList = returnIndexInConversation(firstElOfSecondList, conversation);
+ if(indexOfLastElOfFirstList + 1 == indexOfFirstElOfSecondList) {
+ return SignaturePosition.RIGHT_ADJACENT;
+ }
+ // NOT RIGHT_ADJACENT, so check for LEFT_ADJACENT
+ // Compare the first element of ppListRight with the last element of ppListSecond to know
+ // whether ppListSecond is LEFT_ADJACENT relative to ppListFirst
+ PcapPacket firstElOfFirstList = ppListFirst.get(0);
+ PcapPacket lastElOfSecondList = ppListSecond.get(ppListSecond.size() - 1);
+ // If the positions of the two are in order, then they are adjacent
+ int indexOfFirstElOfFirstList = returnIndexInConversation(firstElOfFirstList, conversation);
+ int indexOfLastElOfSecondList = returnIndexInConversation(lastElOfSecondList, conversation);
+ if(indexOfLastElOfSecondList + 1 == indexOfFirstElOfFirstList) {
+ return SignaturePosition.LEFT_ADJACENT;
+ }
+ }
+ }
+ // Return NOT_ADJACENT if not found
+ return SignaturePosition.NOT_ADJACENT;
+ }
+
+ /**
+ * Given a {@link Conversation} objects, check if {@code List} of {@code PcapPacket} is part of it.
+ * @param conversation The {@link Conversation} object as reference.
+ * @param ppList The {@code List} of {@code PcapPacket} objects to search in the {@link Conversation}.
+ * @return A {@code Boolean} value that represents the presence of the {@code List} of {@code PcapPacket} in
+ * the {@link Conversation}.
+ */
+ private static boolean isPartOfConversation(List<PcapPacket> ppList, Conversation conversation) {
+ // Find the first element of ppList in conversation
+ if (conversation.getPackets().contains(ppList.get(0)))
+ return true;
+ // Return false if not found
+ return false;
+ }
+
+ /**
+ * Given a {@link Conversation} objects, check the index of a {@code PcapPacket} in it.
+ * @param conversation The {@link Conversation} object as reference.
+ * @param pp The {@code PcapPacket} object to search in the {@link Conversation}.
+ * @return An {@code Integer} value that gives the index of the {@code PcapPacket} in the {@link Conversation}.
+ */
+ private static int returnIndexInConversation(PcapPacket pp, Conversation conversation) {
+ // Find pp in conversation
+ if (conversation.getPackets().contains(pp))
+ return conversation.getPackets().indexOf(pp);
+ // Return -1 if not found
+ return -1;
+ }
}