ID2T-toolkit/code_boost/src/cxx/statistics.cpp

#include <iostream>
#include <fstream>
#include <vector>
#include <math.h>
#include "statistics.h"
#include <sstream>
#include <SQLiteCpp/SQLiteCpp.h>
#include "statistics_db.h"
#include "statistics.h"
#include "utilities.h"

using namespace Tins;

/**
 * Checks if there is a payload and increments payloads counter.
 * @param pdu_l4 The packet that should be checked if it has a payload or not.
 */
void statistics::checkPayload(const PDU *pdu_l4) {
    if(this->getDoExtraTests()) {
        // pdu_l4: Tarnsport layer 4
        int pktSize = pdu_l4->size();
        int headerSize = pdu_l4->header_size(); // TCP/UDP header
        int payloadSize = pktSize - headerSize;
        if (payloadSize > 0)
            payloadCount++;
    }
}

/**
 * Checks the correctness of TCP checksum and increments counter if the checksum was incorrect.
 * @param ipAddressSender The source IP.
 * @param ipAddressReceiver The destination IP.
 * @param tcpPkt The packet to get checked.
 */
void statistics::checkTCPChecksum(const IPv4Address ipAddressSender, const IPv4Address ipAddressReceiver, TCP tcpPkt) {
    if(this->getDoExtraTests()) {
        if(check_tcpChecksum(ipAddressSender, ipAddressReceiver, tcpPkt))
            correctTCPChecksumCount++;
        else incorrectTCPChecksumCount++;
    }
}

/**
 * Calculates entropy of the source and destination IPs in a time interval.
 * @param intervalStartTimestamp The timstamp where the interval starts.
 * @return a vector: contains source IP entropy and destination IP entropy.
 */
std::vector<float> statistics::calculateLastIntervalIPsEntropy(std::chrono::microseconds intervalStartTimestamp){
    if(this->getDoExtraTests()) {
        std::vector<int> IPsSrcPktsCounts;
        std::vector<int> IPsDstPktsCounts;

        std::vector<float> IPsSrcProb;
        std::vector<float> IPsDstProb;

        int pktsSent = 0, pktsReceived = 0;

        for (auto i = ip_statistics.begin(); i != ip_statistics.end(); i++) {
            int IPsSrcPktsCount = 0;
            for (auto j = i->second.pkts_sent_timestamp.begin(); j != i->second.pkts_sent_timestamp.end(); j++) {
                if(*j >= intervalStartTimestamp)
                    IPsSrcPktsCount++;
            }
            if(IPsSrcPktsCount != 0) {
                IPsSrcPktsCounts.push_back(IPsSrcPktsCount);
                pktsSent += IPsSrcPktsCount;
            }

            int IPsDstPktsCount = 0;
            for (auto j = i->second.pkts_received_timestamp.begin(); j != i->second.pkts_received_timestamp.end(); j++) {
                if(*j >= intervalStartTimestamp)
                    IPsDstPktsCount++;
            }
            if(IPsDstPktsCount != 0) {
                IPsDstPktsCounts.push_back(IPsDstPktsCount);
                pktsReceived += IPsDstPktsCount;
            }
        }

        for (auto i = IPsSrcPktsCounts.begin(); i != IPsSrcPktsCounts.end(); i++) {
            IPsSrcProb.push_back((float) *i / pktsSent);
        }
        for (auto i = IPsDstPktsCounts.begin(); i != IPsDstPktsCounts.end(); i++) {
            IPsDstProb.push_back((float) *i / pktsReceived);
        }

        // Calculate IP source entropy
        float IPsSrcEntropy = 0;
        for (unsigned i = 0; i < IPsSrcProb.size(); i++) {
            if (IPsSrcProb[i] > 0)
                IPsSrcEntropy += -IPsSrcProb[i] * log2(IPsSrcProb[i]);
        }
        // Calculate IP destination entropy
        float IPsDstEntropy = 0;
        for (unsigned i = 0; i < IPsDstProb.size(); i++) {
            if (IPsDstProb[i] > 0)
                IPsDstEntropy += -IPsDstProb[i] * log2(IPsDstProb[i]);
        }

        std::vector<float> entropies = {IPsSrcEntropy, IPsDstEntropy};
        return entropies;
    }
    else {
        return {-1, -1};
    }
}


/**
 * Calculates the cumulative entropy of the source and destination IPs, i.e., the entropy for packets from the beginning of the pcap file.
 * @return a vector: contains the cumulative entropies of source and destination IPs
 */
std::vector<float> statistics::calculateIPsCumEntropy(){
    if(this->getDoExtraTests()) {
        std::vector <IPv4Address> IPs;
        std::vector <float> IPsSrcProb;
        std::vector <float> IPsDstProb;

        for (auto i = ip_statistics.begin(); i != ip_statistics.end(); i++) {
            IPs.push_back(i->first);
            IPsSrcProb.push_back((float)i->second.pkts_sent/packetCount);
            IPsDstProb.push_back((float)i->second.pkts_received/packetCount);
        }

        // Calculate IP source entropy
        float IPsSrcEntropy = 0;
        for(unsigned i=0; i < IPsSrcProb.size();i++){
            if (IPsSrcProb[i] > 0)
                IPsSrcEntropy += - IPsSrcProb[i]*log2(IPsSrcProb[i]);
        }

        // Calculate IP destination entropy
        float IPsDstEntropy = 0;
        for(unsigned i=0; i < IPsDstProb.size();i++){
            if (IPsDstProb[i] > 0)
                IPsDstEntropy += - IPsDstProb[i]*log2(IPsDstProb[i]);
        }

        std::vector<float> entropies = {IPsSrcEntropy, IPsDstEntropy};
        return entropies;
    }
    else {
    return {-1, -1};
    }
}

/**
 * Calculates sending packet rate for each IP in a time interval. Finds min and max packet rate and adds them to ip_statistics map.
 * @param intervalStartTimestamp The timstamp where the interval starts.
 */
void statistics::calculateIPIntervalPacketRate(std::chrono::duration<int, std::micro> interval, std::chrono::microseconds intervalStartTimestamp){        
        for (auto i = ip_statistics.begin(); i != ip_statistics.end(); i++) {
            int IPsSrcPktsCount = 0;
            for (auto j = i->second.pkts_sent_timestamp.begin(); j != i->second.pkts_sent_timestamp.end(); j++) {
                if(*j >= intervalStartTimestamp)
                    IPsSrcPktsCount++;
            }
            float interval_pkt_rate = (float) IPsSrcPktsCount * 1000000 / interval.count(); // used 10^6 because interval in microseconds
                i->second.interval_pkt_rate.push_back(interval_pkt_rate);
                if(interval_pkt_rate > i->second.max_interval_pkt_rate || i->second.max_interval_pkt_rate == 0)
                    i->second.max_interval_pkt_rate = interval_pkt_rate;
                if(interval_pkt_rate < i->second.min_interval_pkt_rate || i->second.min_interval_pkt_rate == 0)
                    i->second.min_interval_pkt_rate = interval_pkt_rate;
        }
}

/**
 * Registers statistical data for a time interval.
 * @param intervalStartTimestamp The timstamp where the interval starts.
 * @param intervalEndTimestamp The timstamp where the interval ends.
 * @param previousPacketCount The total number of packets in last interval.
 */
void statistics::addIntervalStat(std::chrono::duration<int, std::micro> interval, std::chrono::microseconds intervalStartTimestamp, std::chrono::microseconds intervalEndTimestamp){
    // Add packet rate for each IP to ip_statistics map
    calculateIPIntervalPacketRate(interval, intervalStartTimestamp);
    
    std::vector<float> ipEntopies = calculateLastIntervalIPsEntropy(intervalStartTimestamp);
    std::vector<float> ipCumEntopies = calculateIPsCumEntropy();
    std::string lastPktTimestamp_s = std::to_string(intervalEndTimestamp.count());
    std::string  intervalStartTimestamp_s = std::to_string(intervalStartTimestamp.count());

    // The intervalStartTimestamp_s is the previous interval lastPktTimestamp_s
    interval_statistics[lastPktTimestamp_s].pkts_count = packetCount - intervalCumPktCount;
    interval_statistics[lastPktTimestamp_s].kbytes = (float(sumPacketSize - intervalCumSumPktSize) / 1024);

    interval_statistics[lastPktTimestamp_s].payload_count = payloadCount - intervalPayloadCount;
    interval_statistics[lastPktTimestamp_s].incorrect_tcp_checksum_count = incorrectTCPChecksumCount - intervalIncorrectTCPChecksumCount;
    interval_statistics[lastPktTimestamp_s].correct_tcp_checksum_count = correctTCPChecksumCount - intervalCorrectTCPChecksumCount;
    interval_statistics[lastPktTimestamp_s].novel_ip_count = ip_statistics.size() - intervalCumNovelIPCount;
    interval_statistics[lastPktTimestamp_s].novel_ttl_count = ttl_values.size() - intervalCumNovelTTLCount;
    interval_statistics[lastPktTimestamp_s].novel_win_size_count = win_values.size() - intervalCumNovelWinSizeCount;
    interval_statistics[lastPktTimestamp_s].novel_tos_count = tos_values.size() - intervalCumNovelToSCount;
    interval_statistics[lastPktTimestamp_s].novel_mss_count = mss_values.size() - intervalCumNovelMSSCount;
    interval_statistics[lastPktTimestamp_s].novel_port_count = port_values.size() - intervalCumNovelPortCount;


    intervalPayloadCount = payloadCount;
    intervalIncorrectTCPChecksumCount = incorrectTCPChecksumCount;
    intervalCorrectTCPChecksumCount = correctTCPChecksumCount;
    intervalCumPktCount = packetCount;
    intervalCumSumPktSize = sumPacketSize;
    intervalCumNovelIPCount =  ip_statistics.size();
    intervalCumNovelTTLCount = ttl_values.size();
    intervalCumNovelWinSizeCount = win_values.size();
    intervalCumNovelToSCount = tos_values.size();
    intervalCumNovelMSSCount = mss_values.size();
    intervalCumNovelPortCount = port_values.size();

    if(ipEntopies.size()>1){
        interval_statistics[lastPktTimestamp_s].ip_src_entropy = ipEntopies[0];
        interval_statistics[lastPktTimestamp_s].ip_dst_entropy = ipEntopies[1];
    }
    if(ipCumEntopies.size()>1){
        interval_statistics[lastPktTimestamp_s].ip_src_cum_entropy = ipCumEntopies[0];
        interval_statistics[lastPktTimestamp_s].ip_dst_cum_entropy = ipCumEntopies[1];
    }
}        

/**
 * Registers statistical data for a sent packet in a given conversation (two IPs, two ports). 
 * Increments the counter packets_A_B or packets_B_A.
 * Adds the timestamp of the packet in pkts_A_B_timestamp or pkts_B_A_timestamp.
 * @param ipAddressSender The sender IP address.
 * @param sport The source port.
 * @param ipAddressReceiver The receiver IP address.
 * @param dport The destination port.
 * @param timestamp The timestamp of the packet.
 */
void statistics::addConvStat(const IPv4Address ipAddressSender, std::uint16_t sport,const IPv4Address ipAddressReceiver, std::uint16_t dport, std::chrono::microseconds timestamp){

    conv f1 = {ipAddressReceiver, ipAddressSender, dport, sport};
    conv f2 = {ipAddressSender, ipAddressReceiver, sport, dport};

    // if already exist A(ipAddressReceiver, dport), B(ipAddressSender, sport) conversation
    if (conv_statistics.count(f1)>0){
        conv_statistics[f1].pkts_count++;
        if(conv_statistics[f1].pkts_count<=3)
            conv_statistics[f1].interarrival_time.push_back(std::chrono::duration_cast<std::chrono::microseconds> (timestamp - conv_statistics[f1].pkts_timestamp.back()));
        conv_statistics[f1].pkts_timestamp.push_back(timestamp);
    }
    // Add new conversation A(ipAddressSender, sport), B(ipAddressReceiver, dport)
    else{
        conv_statistics[f2].pkts_count++;
        if(conv_statistics[f2].pkts_timestamp.size()>0 && conv_statistics[f2].pkts_count<=3 )
            conv_statistics[f2].interarrival_time.push_back(std::chrono::duration_cast<std::chrono::microseconds> (timestamp - conv_statistics[f2].pkts_timestamp.back()));
        conv_statistics[f2].pkts_timestamp.push_back(timestamp);
    }
}

/**
 * Registers statistical data for a sent packet in a given extended conversation (two IPs, two ports, protocol). 
 * Increments the counter packets_A_B or packets_B_A.
 * Adds the timestamp of the packet in pkts_A_B_timestamp or pkts_B_A_timestamp.
 * Updates all other statistics of conv_statistics_extended
 * @param ipAddressSender The sender IP address.
 * @param sport The source port.
 * @param ipAddressReceiver The receiver IP address.
 * @param dport The destination port.
 * @param protocol The used protocol.
 * @param timestamp The timestamp of the packet.
 */
void statistics::addConvStatExt(const IPv4Address ipAddressSender, std::uint16_t sport, const IPv4Address ipAddressReceiver, std::uint16_t dport, const char * const protocol, std::chrono::microseconds timestamp){
    if(this->getDoExtraTests()) {
        convWithProt f1 = {ipAddressReceiver, ipAddressSender, dport, sport, protocol};
        convWithProt f2 = {ipAddressSender, ipAddressReceiver, sport, dport, protocol};
        convWithProt f;

        // if there already exists a communication interval for the specified conversation
        if (conv_statistics_extended.count(f1) > 0 || conv_statistics_extended.count(f2) > 0){

            // find out which direction of conversation is contained in conv_statistics_extended
            if (conv_statistics_extended.count(f1) > 0)
                f = f1;
            else
                f = f2;

            // increase pkts count and check on delay
            conv_statistics_extended[f].pkts_count++;
            if (conv_statistics_extended[f].pkts_timestamp.size()>0 && conv_statistics_extended[f].pkts_count<=3)
                conv_statistics_extended[f].interarrival_time.push_back(std::chrono::duration_cast<std::chrono::microseconds> (timestamp - conv_statistics_extended[f].pkts_timestamp.back()));
            conv_statistics_extended[f].pkts_timestamp.push_back(timestamp);

            // if the time difference has exceeded the threshold, create a new interval with this message
            if (timestamp - conv_statistics_extended[f].comm_intervals.back().end > (std::chrono::microseconds) ((unsigned long) COMM_INTERVAL_THRESHOLD)) {  // > or >= ?
                commInterval new_interval = {timestamp, timestamp, 1};
                conv_statistics_extended[f].comm_intervals.push_back(new_interval);
            }
            // otherwise, set the time of the last interval message to the current timestamp and increase interval packet count by 1
            else{
                conv_statistics_extended[f].comm_intervals.back().end = timestamp;
                conv_statistics_extended[f].comm_intervals.back().pkts_count++;
            }
        }
        // if there does not exist a communication interval for the specified conversation
        else{
            // add initial interval entry for this conversation
            commInterval initial_interval = {timestamp, timestamp, 1};

            entry_convStatExt entry;
            entry.comm_intervals.push_back(initial_interval);
            entry.pkts_count = 1;
            entry.pkts_timestamp.push_back(timestamp);
            conv_statistics_extended[f2] = entry;
        }
    }
}

/**
 * Aggregate the collected information about all communication intervals within conv_statistics_extended of every conversation.
 * Do this by computing the average packet rate per interval and the average time between intervals.
 * Also compute average interval duration and total communication duration (i.e. last_msg.time - first_msg.time)
 */
void statistics::createCommIntervalStats(){    
    // iterate over all <convWithProt, entry_convStatExt> pairs
    for (auto &cur_elem : conv_statistics_extended) {
        entry_convStatExt &entry = cur_elem.second;
        std::vector<commInterval> &intervals = entry.comm_intervals;

        // if there is only one interval, the time between intervals cannot be computed and is therefore set to 0
        if (intervals.size() == 1){
            double interval_duration = (double) (intervals[0].end - intervals[0].start).count() / (double) 1e6;
            entry.avg_int_pkts_count = (double) intervals[0].pkts_count;
            entry.avg_time_between_ints = (double) 0;
            entry.avg_interval_time = interval_duration;
        }
        // If there is more than one interval, compute the specified averages
        else if (intervals.size() > 1){
            long summed_pkts_count = intervals[0].pkts_count;
            std::chrono::microseconds time_between_ints_sum = (std::chrono::microseconds) 0;
            std::chrono::microseconds summed_int_duration = intervals[0].end - intervals[0].start;

            for (std::size_t i = 1; i < intervals.size(); i++) {
                summed_pkts_count += intervals[i].pkts_count;
                summed_int_duration += intervals[i].end - intervals[i].start;
                time_between_ints_sum += intervals[i].start - intervals[i - 1].end;
            }

            entry.avg_int_pkts_count = summed_pkts_count / ((double) intervals.size());
            entry.avg_time_between_ints = (time_between_ints_sum.count() / (double) (intervals.size() - 1)) / (double) 1e6;
            entry.avg_interval_time = (summed_int_duration.count() / (double) intervals.size()) / (double) 1e6;

        }
        entry.total_comm_duration = (double) (entry.pkts_timestamp.back() - entry.pkts_timestamp.front()).count() / (double) 1e6;
    }
}

/**
 * Increments the packet counter for the given IP address and MSS value.
 * @param ipAddress The IP address whose MSS packet counter should be incremented.
 * @param mssValue The MSS value of the packet.
 */
void statistics::incrementMSScount(const IPv4Address ipAddress, int mssValue) {
    mss_values[mssValue]++;
    mss_distribution[{ipAddress, mssValue}]++;
}

/**
 * Increments the packet counter for the given IP address and window size.
 * @param ipAddress The IP address whose window size packet counter should be incremented.
 * @param winSize The window size of the packet.
 */
void statistics::incrementWinCount(const IPv4Address ipAddress, int winSize) {
    win_values[winSize]++;
    win_distribution[{ipAddress, winSize}]++;
}

/**
 * Increments the packet counter for the given IP address and TTL value.
 * @param ipAddress The IP address whose TTL packet counter should be incremented.
 * @param ttlValue The TTL value of the packet.
 */
void statistics::incrementTTLcount(const IPv4Address ipAddress, int ttlValue) {
    ttl_values[ttlValue]++;
    ttl_distribution[{ipAddress, ttlValue}]++;
}

/**
 * Increments the packet counter for the given IP address and ToS value.
 * @param ipAddress The IP address whose ToS packet counter should be incremented.
 * @param tosValue The ToS value of the packet.
 */
void statistics::incrementToScount(const IPv4Address ipAddress, int tosValue) {
    tos_values[tosValue]++;
    tos_distribution[{ipAddress, tosValue}]++;
}

/**
 * Increments the protocol counter for the given IP address and protocol.
 * @param ipAddress The IP address whose protocol packet counter should be incremented.
 * @param protocol The protocol of the packet.
 */
void statistics::incrementProtocolCount(const IPv4Address ipAddress, const char * const protocol) {
    protocol_distribution[{ipAddress, protocol}].count++;
}

/**
 * Returns the number of packets seen for the given IP address and protocol.
 * @param ipAddress The IP address whose packet count is wanted.
 * @param protocol The protocol whose packet count is wanted.
 */
int statistics::getProtocolCount(const IPv4Address ipAddress, const char * const protocol) {
    return protocol_distribution[{ipAddress, protocol}].count;
}

/**
 * Increases the byte counter for the given IP address and protocol.
 * @param ipAddress The IP address whose protocol byte counter should be increased.
 * @param protocol The protocol of the packet.
 * @param byteSent The packet's size.
 */
void statistics::increaseProtocolByteCount(const IPv4Address ipAddress, const char * const protocol, long bytesSent) {
    protocol_distribution[{ipAddress, protocol}].byteCount += bytesSent;
}

/**
 * Returns the number of bytes seen for the given IP address and protocol.
 * @param ipAddress The IP address whose byte count is wanted.
 * @param protocol The protocol whose byte count is wanted.
 * @return a float: The number of bytes
 */
float statistics::getProtocolByteCount(const IPv4Address ipAddress, const char * const protocol) {
    return protocol_distribution[{ipAddress, protocol}].byteCount;
}

/**
 * Increments the packet counter for
 * - the given sender IP address with outgoing port and
 * - the given receiver IP address with incoming port.
 * @param ipAddressSender The IP address of the packet sender.
 * @param outgoingPort The port used by the sender.
 * @param ipAddressReceiver The IP address of the packet receiver.
 * @param incomingPort The port used by the receiver.
 */
void statistics::incrementPortCount(const IPv4Address ipAddressSender, std::uint16_t outgoingPort, const IPv4Address ipAddressReceiver,
                                    std::uint16_t incomingPort, const char * const protocol) {
    port_values[outgoingPort]++;
    port_values[incomingPort]++;
    ip_ports[{ipAddressSender, outgoingPort, DIR_OUT, protocol}].count++;
    ip_ports[{ipAddressReceiver, incomingPort, DIR_IN, protocol}].count++;
}

/**
 * Increases the packet byte counter for
 * - the given sender IP address with outgoing port and
 * - the given receiver IP address with incoming port.
 * @param ipAddressSender The IP address of the packet sender.
 * @param outgoingPort The port used by the sender.
 * @param ipAddressReceiver The IP address of the packet receiver.
 * @param incomingPort The port used by the receiver.
 * @param byteSent The packet's size.
 */
void statistics::increasePortByteCount(const IPv4Address ipAddressSender, std::uint16_t outgoingPort, const IPv4Address ipAddressReceiver,
                                       std::uint16_t incomingPort, long bytesSent, const char * const protocol) {
    ip_ports[{ipAddressSender, outgoingPort, DIR_OUT, protocol}].byteCount += bytesSent;
    ip_ports[{ipAddressReceiver, incomingPort, DIR_IN, protocol}].byteCount += bytesSent;
}

/**
 * Increments the packet counter for
 * - the given sender MAC address and
 * - the given receiver MAC address.
 * @param srcMac The MAC address of the packet sender.
 * @param dstMac The MAC address of the packet receiver.
 * @param typeNumber The payload type number of the packet.
 */
void statistics::incrementUnrecognizedPDUCount(const std::string &srcMac, const std::string &dstMac, uint32_t typeNumber,
                                               const std::string &timestamp) {
    unrecognized_PDUs[{srcMac, dstMac, typeNumber}].count++;
    unrecognized_PDUs[{srcMac, dstMac, typeNumber}].timestamp_last_occurrence = timestamp;
}

/**
 * Creates a new statistics object.
 */
statistics::statistics(void) {
}

/**
 * Stores the assignment IP address -> MAC address.
 * @param ipAddress The IP address belonging to the given MAC address.
 * @param macAddress The MAC address belonging to the given IP address.
 */
void statistics::assignMacAddress(const IPv4Address ipAddress, const std::string &macAddress) {
    ip_mac_mapping[ipAddress] = macAddress;
}

/**
 * Registers statistical data for a sent packet. Increments the counter packets_sent for the sender and
 * packets_received for the receiver. Adds the bytes as kbytes_sent (sender) and kybtes_received (receiver).
 * @param ipAddressSender The IP address of the packet sender.
 * @param ipAddressReceiver The IP address of the packet receiver.
 * @param bytesSent The packet's size.
 */
void statistics::addIpStat_packetSent(const IPv4Address ipAddressSender, const IPv4Address ipAddressReceiver, long bytesSent, std::chrono::microseconds timestamp) {

    // Adding IP as a sender for first time
    if(ip_statistics[ipAddressSender].pkts_sent==0){  
        // Add the IP class
        ip_statistics[ipAddressSender].ip_class = getIPv4Class(ipAddressSender);
    }
    
    // Adding IP as a receiver for first time
    if(ip_statistics[ipAddressReceiver].pkts_received==0){
        // Add the IP class
        ip_statistics[ipAddressReceiver].ip_class = getIPv4Class(ipAddressReceiver);
    }

    // Update stats for packet sender
    ip_statistics[ipAddressSender].kbytes_sent += (float(bytesSent) / 1024);
    ip_statistics[ipAddressSender].pkts_sent++;
    ip_statistics[ipAddressSender].pkts_sent_timestamp.push_back(timestamp);
                
    // Update stats for packet receiver
    ip_statistics[ipAddressReceiver].kbytes_received += (float(bytesSent) / 1024);
    ip_statistics[ipAddressReceiver].pkts_received++;
    ip_statistics[ipAddressReceiver].pkts_received_timestamp.push_back(timestamp);

    if(this->getDoExtraTests()) {
        // Increment Degrees for sender and receiver, if Sender sends its first packet to this receiver
        std::unordered_set<IPv4Address>::const_iterator found_receiver = contacted_ips[ipAddressSender].find(ipAddressReceiver);
        if(found_receiver == contacted_ips[ipAddressSender].end()){
            // Receiver is NOT contained in the List of IPs, that the Sender has contacted, therefore this is the first packet in this direction
            ip_statistics[ipAddressSender].out_degree++;
            ip_statistics[ipAddressReceiver].in_degree++;

            // Increment overall_degree only if this is the first packet for the connection (both directions)
            // Therefore check, whether Receiver has contacted Sender before
            std::unordered_set<IPv4Address>::const_iterator sender_contacted = contacted_ips[ipAddressReceiver].find(ipAddressSender);
            if(sender_contacted == contacted_ips[ipAddressReceiver].end()){
                ip_statistics[ipAddressSender].overall_degree++;
                ip_statistics[ipAddressReceiver].overall_degree++;
            }

            contacted_ips[ipAddressSender].insert(ipAddressReceiver);
        }
    }
}

/**
 * Setter for the timestamp_firstPacket field.
 * @param ts The timestamp of the first packet in the PCAP file.
 */
void statistics::setTimestampFirstPacket(Tins::Timestamp ts) {
    timestamp_firstPacket = ts;
}

/**
 * Setter for the timestamp_lastPacket field.
 * @param ts The timestamp of the last packet in the PCAP file.
 */
void statistics::setTimestampLastPacket(Tins::Timestamp ts) {
    timestamp_lastPacket = ts;
}

/**
 * Getter for the timestamp_firstPacket field.
 */
Tins::Timestamp statistics::getTimestampFirstPacket() {
    return timestamp_firstPacket;
}

/**
 * Getter for the timestamp_lastPacket field.
 */
Tins::Timestamp statistics::getTimestampLastPacket() {
    return timestamp_lastPacket;
}

/**
 * Getter for the packetCount field.
 */
int statistics::getPacketCount() {
    return packetCount;
}

/**
 * Getter for the sumPacketSize field.
 */
int statistics::getSumPacketSize() {
    return sumPacketSize;
}


/**
 * Returns the average packet size.
 * @return a float indicating the average packet size in kbytes.
 */
float statistics::getAvgPacketSize() const {
    // AvgPktSize = (Sum of all packet sizes / #Packets)
    return (sumPacketSize / packetCount) / 1024;
}

/**
 * Adds the size of a packet (to be used to calculate the avg. packet size).
 * @param packetSize The size of the current packet in bytes.
 */
void statistics::addPacketSize(uint32_t packetSize) {
    sumPacketSize += ((float) packetSize);
}

/**
 * Setter for the doExtraTests field.
 */
void statistics::setDoExtraTests(bool var) {
    doExtraTests = var;
}

/**
 * Getter for the doExtraTests field.
 */
bool statistics::getDoExtraTests() {
    return doExtraTests;
}


/**
 * Calculates the capture duration.
 * @return a formatted string HH:MM:SS.mmmmmm with
 * HH: hour, MM: minute, SS: second, mmmmmm: microseconds
 */
std::string statistics::getCaptureDurationTimestamp() const {
    // Calculate duration
    timeval fp, lp, d;
    fp.tv_sec = timestamp_firstPacket.seconds();
    fp.tv_usec = timestamp_firstPacket.microseconds();
    lp.tv_sec = timestamp_lastPacket.seconds();
    lp.tv_usec = timestamp_lastPacket.microseconds();
    timersub(&lp, &fp, &d);
    long int hour = d.tv_sec / 3600;
    long int remainder = (d.tv_sec - hour * 3600);
    long int minute = remainder / 60;
    long int second = (remainder - minute * 60) % 60;
    long int microseconds = d.tv_usec;
    // Build desired output format: YYYY-mm-dd hh:mm:ss
    char out[64];
    sprintf(out, "%02ld:%02ld:%02ld.%06ld ", hour, minute, second, microseconds);
    return std::string(out);
}

/**
 * Calculates the capture duration.
 * @return a formatted string SS.mmmmmm with
 * S: seconds (UNIX time), mmmmmm: microseconds
 */
float statistics::getCaptureDurationSeconds() const {
    timeval fp, lp, d;
    fp.tv_sec = timestamp_firstPacket.seconds();
    fp.tv_usec = timestamp_firstPacket.microseconds();
    lp.tv_sec = timestamp_lastPacket.seconds();
    lp.tv_usec = timestamp_lastPacket.microseconds();
    timersub(&lp, &fp, &d);
    char buf[64];
    snprintf(buf, sizeof(buf), "%u.%06u", static_cast<uint>(d.tv_sec), static_cast<uint>(d.tv_usec));
    return std::stof(std::string(buf));
}

/**
 * Creates a timestamp based on a time_t seconds (UNIX time format) and microseconds.
 * @param seconds
 * @param microseconds
 * @return a formatted string Y-m-d H:M:S.m with
 * Y: year, m: month, d: day, H: hour, M: minute, S: second, m: microseconds
 */
std::string statistics::getFormattedTimestamp(time_t seconds, suseconds_t microseconds) const {
    timeval tv;
    tv.tv_sec = seconds;
    tv.tv_usec = microseconds;
    char tmbuf[64], buf[64];
    auto nowtm = localtime(&(tv.tv_sec));
    strftime(tmbuf, sizeof(tmbuf), "%Y-%m-%d %H:%M:%S", nowtm);
    snprintf(buf, sizeof(buf), "%s.%06u", tmbuf, static_cast<uint>(tv.tv_usec));
    return std::string(buf);
}

/**
 * Calculates the statistics for a given IP address.
 * @param ipAddress The IP address whose statistics should be calculated.
 * @return a ip_stats struct containing statistical data derived by the statistical data collected.
 */
ip_stats statistics::getStatsForIP(const IPv4Address ipAddress) {
    float duration = getCaptureDurationSeconds();
    entry_ipStat ipStatEntry = ip_statistics[ipAddress];

    ip_stats s;
    s.bandwidthKBitsIn = (ipStatEntry.kbytes_received / duration) * 8;
    s.bandwidthKBitsOut = (ipStatEntry.kbytes_sent / duration) * 8;
    s.packetPerSecondIn = (ipStatEntry.pkts_received / duration);
    s.packetPerSecondOut = (ipStatEntry.pkts_sent / duration);
    s.AvgPacketSizeSent = (ipStatEntry.kbytes_sent / ipStatEntry.pkts_sent);
    s.AvgPacketSizeRecv = (ipStatEntry.kbytes_received / ipStatEntry.pkts_received);
    return s;
}

/**
 * Increments the packet counter.
 */
void statistics::incrementPacketCount() {
    packetCount++;
}

/**
 * Prints the statistics of the PCAP and IP specific statistics for the given IP address.
 * @param ipAddress The IP address whose statistics should be printed. Can be empty "" to print only general file statistics.
 */
void statistics::printStats(const std::string &ipAddress) {
    std::stringstream ss;
    ss << std::endl;
    ss << "Capture duration: " << getCaptureDurationSeconds() << " seconds" << std::endl;
    ss << "Capture duration (HH:MM:SS.mmmmmm): " << getCaptureDurationTimestamp() << std::endl;
    ss << "#Packets: " << packetCount << std::endl;
    ss << std::endl;

    // Print IP address specific statistics only if IP address was given
    if (ipAddress != "") {
        entry_ipStat e = ip_statistics[ipAddress];
        ss << "\n----- STATS FOR IP ADDRESS [" << ipAddress << "] -------" << std::endl;
        ss << std::endl << "KBytes sent: " << e.kbytes_sent << std::endl;
        ss << "KBytes received: " << e.kbytes_received << std::endl;
        ss << "Packets sent: " << e.pkts_sent << std::endl;
        ss << "Packets received: " << e.pkts_received << "\n\n";

        ip_stats is = getStatsForIP(ipAddress);
        ss << "Bandwidth IN: " << is.bandwidthKBitsIn << " kbit/s" << std::endl;
        ss << "Bandwidth OUT: " << is.bandwidthKBitsOut << " kbit/s" << std::endl;
        ss << "Packets per second IN: " << is.packetPerSecondIn << std::endl;
        ss << "Packets per second OUT: " << is.packetPerSecondOut << std::endl;
        ss << "Avg Packet Size Sent: " << is.AvgPacketSizeSent << " kbytes" << std::endl;
        ss << "Avg Packet Size Received: " << is.AvgPacketSizeRecv << " kbytes" << std::endl;
    }
    std::cout << ss.str();
}

/**
 * Derives general PCAP file statistics from the collected statistical data and
 * writes all data into a SQLite database, located at database_path.
 * @param database_path The path of the SQLite database file ending with .sqlite3.
 */
void statistics::writeToDatabase(std::string database_path) {
    // Generate general file statistics
    float duration = getCaptureDurationSeconds();
    long sumPacketsSent = 0, senderCountIP = 0;
    float sumBandwidthIn = 0.0, sumBandwidthOut = 0.0;
    for (auto i = ip_statistics.begin(); i != ip_statistics.end(); i++) {
        sumPacketsSent += i->second.pkts_sent;
        // Consumed bandwith (bytes) for sending packets
        sumBandwidthIn += (i->second.kbytes_received / duration);
        sumBandwidthOut += (i->second.kbytes_sent / duration);
        senderCountIP++;
    }

    float avgPacketRate = (packetCount / duration);
    long avgPacketSize = getAvgPacketSize();
    if(senderCountIP>0) {
        long avgPacketsSentPerHost = (sumPacketsSent / senderCountIP);
        float avgBandwidthInKBits = (sumBandwidthIn / senderCountIP) * 8;
        float avgBandwidthOutInKBits = (sumBandwidthOut / senderCountIP) * 8;

        // Create database and write information
        statistics_db db(database_path);
        db.writeStatisticsFile(packetCount, getCaptureDurationSeconds(),
                               getFormattedTimestamp(timestamp_firstPacket.seconds(), timestamp_firstPacket.microseconds()),
                               getFormattedTimestamp(timestamp_lastPacket.seconds(), timestamp_lastPacket.microseconds()),
                               avgPacketRate, avgPacketSize, avgPacketsSentPerHost, avgBandwidthInKBits,
                               avgBandwidthOutInKBits, doExtraTests);
        db.writeStatisticsIP(ip_statistics);
        db.writeStatisticsTTL(ttl_distribution);
        db.writeStatisticsIpMac(ip_mac_mapping);
        db.writeStatisticsDegree(ip_statistics);
        db.writeStatisticsPorts(ip_ports);
        db.writeStatisticsProtocols(protocol_distribution);
        db.writeStatisticsMSS(mss_distribution);
        db.writeStatisticsToS(tos_distribution);
        db.writeStatisticsWin(win_distribution);
        db.writeStatisticsConv(conv_statistics);
        db.writeStatisticsConvExt(conv_statistics_extended);
        db.writeStatisticsInterval(interval_statistics);
        db.writeDbVersion();
        db.writeStatisticsUnrecognizedPDUs(unrecognized_PDUs);
    }
    else {
        // Tinslib failed to recognize the types of the packets in the input PCAP
        std::cout<<"ERROR: Statistics could not be collected from the input PCAP!"<<"\n";
        return;
    }
}