ID2T-toolkit-BotnetTraffic/code/ID2TLib/CommunicationProcessor.py

from lea import Lea
from Attack.MembersMgmtCommAttack import MessageType
from Attack.MembersMgmtCommAttack import Message

# needed because of machine inprecision. E.g A time difference of 0.1s is stored as >0.1s
EPS_TOLERANCE = 1e-13  # works for a difference of 0.1, no less

def greater_than(a: float, b: float):
    """
    A greater than operator desgined to handle slight machine inprecision up to EPS_TOLERANCE.
    :return: True if a > b, otherwise False
    """
    return b - a < -EPS_TOLERANCE

class CommunicationProcessor():
    """
    Class to process parsed input CSV/XML data and retrieve a mapping or other information.
    """

    def __init__(self, packets:list, mtypes:dict, nat:bool):
        """
        Creates an instance of CommunicationProcessor.
        :param packets: the list of abstract packets
        :param mtypes: a dict containing an int to EnumType mapping of MessageTypes
        :param nat: whether NAT is present in this network
        """
        self.packets = packets
        self.mtypes = mtypes
        self.nat = nat

    def set_mapping(self, packets: list, mapped_ids: dict):
        """
        Set the selected mapping for this communication processor.

        :param packets: all packets contained in the mapped time frame
        :param mapped_ids: the chosen IDs
        """
        self.packets = packets
        self.local_init_ids = set(mapped_ids)

    def find_interval_most_comm(self, number_ids: int, max_int_time: float):
        """
        Finds the time interval(s) of the given seconds with the most overall communication (i.e. requests and responses)
        that has at least number_ids communication initiators in it. 
        :param number_ids: The number of initiator IDs that have to exist in the interval(s)
        :param max_int_time: The maximum time period of the interval
        :return: A list of triples, where each triple contains the initiator IDs, the start index and end index
                 of the respective interval in that order. The indices are with respect to self.packets
        """

        # setup initial variables
        packets = self.packets
        mtypes = self.mtypes
        idx_low, idx_high = 0, 0  # the indices spanning the interval
        comm_sum = 0  # the communication sum of the current interval
        cur_highest_sum = 0  # the highest communication sum seen so far
        init_ids = []  # the initiator IDs seen in the current interval in order of appearance
        possible_intervals = []  # all intervals that have cur_highest_sum of communication and contain enough IDs

        # Iterate over all packets from start to finish and process the info of each packet.
        # Similar to a Sliding Window approach.
        while True:
            if idx_high < len(packets):
                cur_int_time = float(packets[idx_high]["Time"]) - float(packets[idx_low]["Time"])
     
            # if current interval time exceeds maximum time period, process information of the current interval
            if greater_than(cur_int_time, max_int_time) or idx_high >= len(packets):
                interval_ids = set(init_ids)
                # if the interval contains enough initiator IDs, add it to possible_intervals
                if len(interval_ids) >= number_ids:
                    interval = {"IDs": sorted(interval_ids), "Start": idx_low, "End": idx_high-1}
                    # reset possible intervals if new maximum of communication is found
                    if comm_sum > cur_highest_sum:
                        possible_intervals = [interval]
                        cur_highest_sum = comm_sum
                    # append otherwise
                    elif comm_sum == cur_highest_sum:
                        possible_intervals.append(interval)

                # stop if all packets have been processed
                if idx_high >= len(packets):
                    break

            # let idx_low "catch up" so that the current interval time fits into the maximum time period again
            while greater_than(cur_int_time, max_int_time):
                cur_packet = packets[idx_low]
                # if message was no timeout, delete the first appearance of the initiator ID 
                # of this packet from the initiator list and update comm_sum
                if mtypes[int(cur_packet["Type"])] != MessageType.TIMEOUT:
                    comm_sum -= 1
                    del init_ids[0]

                idx_low += 1
                cur_int_time = float(packets[idx_high]["Time"]) - float(packets[idx_low]["Time"])

            # consume the new packet at idx_high and process its information
            cur_packet = packets[idx_high]
            cur_mtype = mtypes[int(cur_packet["Type"])]
            # if message is request, add src to initiator list
            if MessageType.is_request(cur_mtype):
                init_ids.append(cur_packet["Src"])
                comm_sum += 1
            # if message is response, add dst to initiator list
            elif MessageType.is_response(cur_mtype):
                init_ids.append(cur_packet["Dst"])
                comm_sum += 1

            idx_high += 1

        return possible_intervals

    def det_id_roles_and_msgs(self):
        """
        Determine the role of every mapped ID. The role can be initiator, responder or both.
        On the side also connect corresponding messages together to quickly find out
        which reply belongs to which request and vice versa.

        :return: a triple as (initiator IDs, responder IDs, messages)
        """

        mtypes = self.mtypes
        # setup initial variables and their values
        respnd_ids = set()
        # msgs --> the filtered messages, msg_id --> an increasing ID to give every message an artificial primary key
        msgs, msg_id = [], 0
        # keep track of previous request to find connections
        prev_reqs = {}
        # used to determine whether a request has been seen yet, so that replies before the first request are skipped and do not throw an error by
        # accessing the empty dict prev_reqs (this is not a perfect solution, but it works most of the time)
        req_seen = False
        local_init_ids = self.local_init_ids
        external_init_ids = set()

        # process every packet individually 
        for packet in self.packets:
            id_src, id_dst, msg_type, time = packet["Src"], packet["Dst"], int(packet["Type"]), float(packet["Time"])
            lineno = packet.get("LineNumber", -1)
            # if if either one of the IDs is not mapped, continue
            if (id_src not in local_init_ids) and (id_dst not in local_init_ids):
                continue

            # convert message type number to enum type
            msg_type = mtypes[msg_type]

            # process a request
            if msg_type in {MessageType.SALITY_HELLO, MessageType.SALITY_NL_REQUEST}:
                if not self.nat and id_dst in local_init_ids and id_src not in local_init_ids:
                    external_init_ids.add(id_src)
                elif id_src not in local_init_ids:
                    continue
                else:
                    # process ID's role
                    respnd_ids.add(id_dst)
                # convert the abstract message into a message object to handle it better
                msg_str = "{0}-{1}".format(id_src, id_dst)
                msg = Message(msg_id, id_src, id_dst, msg_type, time, line_no = lineno)
                msgs.append(msg)
                prev_reqs[msg_str] = msg_id
                msg_id += 1
                req_seen = True

            # process a reply
            elif msg_type in {MessageType.SALITY_HELLO_REPLY, MessageType.SALITY_NL_REPLY} and req_seen:
                if not self.nat and id_src in local_init_ids and id_dst not in local_init_ids:
                    # process ID's role
                    external_init_ids.add(id_dst)
                elif id_dst not in local_init_ids:
                    continue
                else: 
                    # process ID's role
                    respnd_ids.add(id_src)
                # convert the abstract message into a message object to handle it better
                msg_str = "{0}-{1}".format(id_dst, id_src)
                # find the request message ID for this response and set its reference index
                refer_idx = prev_reqs[msg_str]
                msgs[refer_idx].refer_msg_id = msg_id
                msg = Message(msg_id, id_src, id_dst, msg_type, time, refer_idx, lineno)
                msgs.append(msg)
                # remove the request to this response from storage
                del(prev_reqs[msg_str])
                msg_id += 1

            elif msg_type == MessageType.TIMEOUT and id_src in local_init_ids and not self.nat:
                # convert the abstract message into a message object to handle it better
                msg_str = "{0}-{1}".format(id_dst, id_src)
                # find the request message ID for this response and set its reference index
                refer_idx = prev_reqs.get(msg_str)
                if refer_idx is not None:
                    msgs[refer_idx].refer_msg_id = msg_id
                    if msgs[refer_idx].type == MessageType.SALITY_NL_REQUEST:
                        msg = Message(msg_id, id_src, id_dst, MessageType.SALITY_NL_REPLY, time, refer_idx, lineno)
                    else:
                        msg = Message(msg_id, id_src, id_dst, MessageType.SALITY_HELLO_REPLY, time, refer_idx, lineno)
                    msgs.append(msg)
                    # remove the request to this response from storage
                    del(prev_reqs[msg_str])
                    msg_id += 1

        # store the retrieved information in this object for later use
        self.respnd_ids = sorted(respnd_ids)
        self.external_init_ids = sorted(external_init_ids)
        self.messages = msgs

        # return the retrieved information
        return self.local_init_ids, self.external_init_ids, self.respnd_ids, self.messages

    def det_ext_and_local_ids(self, prob_rspnd_local: int=0):
        """
        Map the given IDs to a locality (i.e. local or external} considering the given probabilities.

        :param comm_type: the type of communication (i.e. local, external or mixed)
        :param prob_rspnd_local: the probabilty that a responder is local
        """
        external_ids = set()
        local_ids = self.local_init_ids.copy()
        
        # set up probabilistic chooser
        rspnd_locality = Lea.fromValFreqsDict({"local": prob_rspnd_local*100, "external": (1-prob_rspnd_local)*100})

        for id_ in self.external_init_ids:
            external_ids.add(id_)

        # determine responder localities
        for id_ in self.respnd_ids:
            if id_ in local_ids or id_ in external_ids:
                continue 
            
            pos = rspnd_locality.random() 
            if pos == "local":
                local_ids.add(id_)
            elif pos == "external":
                external_ids.add(id_)

        self.local_ids, self.external_ids = local_ids, external_ids
        return self.local_ids, self.external_ids