/*
 * Copyright (c) 2011 Yufei Cheng
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 * Author: Yufei Cheng   <yfcheng@ittc.ku.edu>
 *
 * James P.G. Sterbenz <jpgs@ittc.ku.edu>, director
 * ResiliNets Research Group  https://resilinets.org/
 * Information and Telecommunication Technology Center (ITTC)
 * and Department of Electrical Engineering and Computer Science
 * The University of Kansas Lawrence, KS USA.
 *
 * Work supported in part by NSF FIND (Future Internet Design) Program
 * under grant CNS-0626918 (Postmodern Internet Architecture),
 * NSF grant CNS-1050226 (Multilayer Network Resilience Analysis and Experimentation on GENI),
 * US Department of Defense (DoD), and ITTC at The University of Kansas.
 */

#define NS_LOG_APPEND_CONTEXT                                                                      \
    if (GetObject<Node>())                                                                         \
    {                                                                                              \
        std::clog << "[node " << GetObject<Node>()->GetId() << "] ";                               \
    }

#include "dsr-routing.h"

#include "dsr-fs-header.h"
#include "dsr-options.h"
#include "dsr-rcache.h"
#include "dsr-rreq-table.h"

#include "ns3/adhoc-wifi-mac.h"
#include "ns3/arp-header.h"
#include "ns3/assert.h"
#include "ns3/boolean.h"
#include "ns3/config.h"
#include "ns3/double.h"
#include "ns3/enum.h"
#include "ns3/icmpv4-l4-protocol.h"
#include "ns3/inet-socket-address.h"
#include "ns3/ipv4-address.h"
#include "ns3/ipv4-header.h"
#include "ns3/ipv4-l3-protocol.h"
#include "ns3/ipv4-route.h"
#include "ns3/ipv6-interface.h"
#include "ns3/llc-snap-header.h"
#include "ns3/log.h"
#include "ns3/net-device.h"
#include "ns3/node-list.h"
#include "ns3/object-vector.h"
#include "ns3/packet.h"
#include "ns3/pointer.h"
#include "ns3/ptr.h"
#include "ns3/string.h"
#include "ns3/tcp-socket-factory.h"
#include "ns3/timer.h"
#include "ns3/trace-source-accessor.h"
#include "ns3/udp-l4-protocol.h"
#include "ns3/udp-socket-factory.h"
#include "ns3/uinteger.h"
#include "ns3/wifi-net-device.h"

#include <algorithm>
#include <ctime>
#include <iostream>
#include <limits>
#include <list>
#include <map>

namespace ns3
{

NS_LOG_COMPONENT_DEFINE("DsrRouting");

namespace dsr
{

NS_OBJECT_ENSURE_REGISTERED(DsrRouting);

/* see http://www.iana.org/assignments/protocol-numbers */
const uint8_t DsrRouting::PROT_NUMBER = 48;

/*
 * The extension header is the fixed size dsr header, it is response for recognizing DSR option
 types
 * and demux to right options to process the packet.
 *
 * The header format with neighboring layers is as follows:
 *
 +-+-+-+-+-+-+-+-+-+-+-
 |  Application Header |
 +-+-+-+-+-+-+-+-+-+-+-+
 |   Transport Header  |
 +-+-+-+-+-+-+-+-+-+-+-+
 |   Fixed DSR Header  |
 +---------------------+
 |     DSR Options     |
 +-+-+-+-+-+-+-+-+-+-+-+
 |      IP Header      |
 +-+-+-+-+-+-+-+-+-+-+-+
 */

TypeId
DsrRouting::GetTypeId()
{
    static TypeId tid =
        TypeId("ns3::dsr::DsrRouting")
            .SetParent<IpL4Protocol>()
            .SetGroupName("Dsr")
            .AddConstructor<DsrRouting>()
            .AddAttribute(
                "RouteCache",
                "The route cache for saving routes from "
                "route discovery process.",
                PointerValue(nullptr),
                MakePointerAccessor(&DsrRouting::SetRouteCache, &DsrRouting::GetRouteCache),
                MakePointerChecker<DsrRouteCache>())
            .AddAttribute(
                "RreqTable",
                "The request table to manage route requests.",
                PointerValue(nullptr),
                MakePointerAccessor(&DsrRouting::SetRequestTable, &DsrRouting::GetRequestTable),
                MakePointerChecker<DsrRreqTable>())
            .AddAttribute(
                "PassiveBuffer",
                "The passive buffer to manage "
                "promiscuously received passive ack.",
                PointerValue(nullptr),
                MakePointerAccessor(&DsrRouting::SetPassiveBuffer, &DsrRouting::GetPassiveBuffer),
                MakePointerChecker<DsrPassiveBuffer>())
            .AddAttribute("MaxSendBuffLen",
                          "Maximum number of packets that can be stored "
                          "in send buffer.",
                          UintegerValue(64),
                          MakeUintegerAccessor(&DsrRouting::m_maxSendBuffLen),
                          MakeUintegerChecker<uint32_t>())
            .AddAttribute("MaxSendBuffTime",
                          "Maximum time packets can be queued in the send buffer .",
                          TimeValue(Seconds(30)),
                          MakeTimeAccessor(&DsrRouting::m_sendBufferTimeout),
                          MakeTimeChecker())
            .AddAttribute("MaxMaintLen",
                          "Maximum number of packets that can be stored "
                          "in maintenance buffer.",
                          UintegerValue(50),
                          MakeUintegerAccessor(&DsrRouting::m_maxMaintainLen),
                          MakeUintegerChecker<uint32_t>())
            .AddAttribute("MaxMaintTime",
                          "Maximum time packets can be queued in maintenance buffer.",
                          TimeValue(Seconds(30)),
                          MakeTimeAccessor(&DsrRouting::m_maxMaintainTime),
                          MakeTimeChecker())
            .AddAttribute("MaxCacheLen",
                          "Maximum number of route entries that can be stored "
                          "in route cache.",
                          UintegerValue(64),
                          MakeUintegerAccessor(&DsrRouting::m_maxCacheLen),
                          MakeUintegerChecker<uint32_t>())
            .AddAttribute("RouteCacheTimeout",
                          "Maximum time the route cache can be queued in "
                          "route cache.",
                          TimeValue(Seconds(300)),
                          MakeTimeAccessor(&DsrRouting::m_maxCacheTime),
                          MakeTimeChecker())
            .AddAttribute("MaxEntriesEachDst",
                          "Maximum number of route entries for a "
                          "single destination to respond.",
                          UintegerValue(20),
                          MakeUintegerAccessor(&DsrRouting::m_maxEntriesEachDst),
                          MakeUintegerChecker<uint32_t>())
            .AddAttribute("SendBuffInterval",
                          "How often to check send buffer for packet with route.",
                          TimeValue(Seconds(500)),
                          MakeTimeAccessor(&DsrRouting::m_sendBuffInterval),
                          MakeTimeChecker())
            .AddAttribute("NodeTraversalTime",
                          "The time it takes to traverse two neighboring nodes.",
                          TimeValue(MilliSeconds(40)),
                          MakeTimeAccessor(&DsrRouting::m_nodeTraversalTime),
                          MakeTimeChecker())
            .AddAttribute("RreqRetries",
                          "Maximum number of retransmissions for "
                          "request discovery of a route.",
                          UintegerValue(16),
                          MakeUintegerAccessor(&DsrRouting::m_rreqRetries),
                          MakeUintegerChecker<uint32_t>())
            .AddAttribute("MaintenanceRetries",
                          "Maximum number of retransmissions for "
                          "data packets from maintenance buffer.",
                          UintegerValue(2),
                          MakeUintegerAccessor(&DsrRouting::m_maxMaintRexmt),
                          MakeUintegerChecker<uint32_t>())
            .AddAttribute("RequestTableSize",
                          "Maximum number of request entries in the request table, "
                          "set this as the number of nodes in the simulation.",
                          UintegerValue(64),
                          MakeUintegerAccessor(&DsrRouting::m_requestTableSize),
                          MakeUintegerChecker<uint32_t>())
            .AddAttribute("RequestIdSize",
                          "Maximum number of request source Ids in "
                          "the request table.",
                          UintegerValue(16),
                          MakeUintegerAccessor(&DsrRouting::m_requestTableIds),
                          MakeUintegerChecker<uint32_t>())
            .AddAttribute("UniqueRequestIdSize",
                          "Maximum number of request Ids in "
                          "the request table for a single destination.",
                          UintegerValue(256),
                          MakeUintegerAccessor(&DsrRouting::m_maxRreqId),
                          MakeUintegerChecker<uint32_t>())
            .AddAttribute("NonPropRequestTimeout",
                          "The timeout value for non-propagation request.",
                          TimeValue(MilliSeconds(30)),
                          MakeTimeAccessor(&DsrRouting::m_nonpropRequestTimeout),
                          MakeTimeChecker())
            .AddAttribute("DiscoveryHopLimit",
                          "The max discovery hop limit for route requests.",
                          UintegerValue(255),
                          MakeUintegerAccessor(&DsrRouting::m_discoveryHopLimit),
                          MakeUintegerChecker<uint32_t>())
            .AddAttribute("MaxSalvageCount",
                          "The max salvage count for a single data packet.",
                          UintegerValue(15),
                          MakeUintegerAccessor(&DsrRouting::m_maxSalvageCount),
                          MakeUintegerChecker<uint8_t>())
            .AddAttribute("BlacklistTimeout",
                          "The time for a neighbor to stay in blacklist.",
                          TimeValue(Seconds(3)),
                          MakeTimeAccessor(&DsrRouting::m_blacklistTimeout),
                          MakeTimeChecker())
            .AddAttribute("GratReplyHoldoff",
                          "The time for gratuitous reply entry to expire.",
                          TimeValue(Seconds(1)),
                          MakeTimeAccessor(&DsrRouting::m_gratReplyHoldoff),
                          MakeTimeChecker())
            .AddAttribute("BroadcastJitter",
                          "The jitter time to avoid collision for broadcast packets.",
                          UintegerValue(10),
                          MakeUintegerAccessor(&DsrRouting::m_broadcastJitter),
                          MakeUintegerChecker<uint32_t>())
            .AddAttribute("LinkAckTimeout",
                          "The time a packet in maintenance buffer wait for "
                          "link acknowledgment.",
                          TimeValue(MilliSeconds(100)),
                          MakeTimeAccessor(&DsrRouting::m_linkAckTimeout),
                          MakeTimeChecker())
            .AddAttribute("TryLinkAcks",
                          "The number of link acknowledgment to use.",
                          UintegerValue(1),
                          MakeUintegerAccessor(&DsrRouting::m_tryLinkAcks),
                          MakeUintegerChecker<uint32_t>())
            .AddAttribute("PassiveAckTimeout",
                          "The time a packet in maintenance buffer wait for "
                          "passive acknowledgment.",
                          TimeValue(MilliSeconds(100)),
                          MakeTimeAccessor(&DsrRouting::m_passiveAckTimeout),
                          MakeTimeChecker())
            .AddAttribute("TryPassiveAcks",
                          "The number of passive acknowledgment to use.",
                          UintegerValue(1),
                          MakeUintegerAccessor(&DsrRouting::m_tryPassiveAcks),
                          MakeUintegerChecker<uint32_t>())
            .AddAttribute("RequestPeriod",
                          "The base time interval between route requests.",
                          TimeValue(MilliSeconds(500)),
                          MakeTimeAccessor(&DsrRouting::m_requestPeriod),
                          MakeTimeChecker())
            .AddAttribute("MaxRequestPeriod",
                          "The max time interval between route requests.",
                          TimeValue(Seconds(10)),
                          MakeTimeAccessor(&DsrRouting::m_maxRequestPeriod),
                          MakeTimeChecker())
            .AddAttribute("GraReplyTableSize",
                          "The gratuitous reply table size.",
                          UintegerValue(64),
                          MakeUintegerAccessor(&DsrRouting::m_graReplyTableSize),
                          MakeUintegerChecker<uint32_t>())
            .AddAttribute("CacheType",
                          "Use Link Cache or use Path Cache",
                          StringValue("LinkCache"),
                          MakeStringAccessor(&DsrRouting::m_cacheType),
                          MakeStringChecker())
            .AddAttribute("StabilityDecrFactor",
                          "The stability decrease factor for link cache",
                          UintegerValue(2),
                          MakeUintegerAccessor(&DsrRouting::m_stabilityDecrFactor),
                          MakeUintegerChecker<uint32_t>())
            .AddAttribute("StabilityIncrFactor",
                          "The stability increase factor for link cache",
                          UintegerValue(4),
                          MakeUintegerAccessor(&DsrRouting::m_stabilityIncrFactor),
                          MakeUintegerChecker<uint32_t>())
            .AddAttribute("InitStability",
                          "The initial stability factor for link cache",
                          TimeValue(Seconds(25)),
                          MakeTimeAccessor(&DsrRouting::m_initStability),
                          MakeTimeChecker())
            .AddAttribute("MinLifeTime",
                          "The minimal life time for link cache",
                          TimeValue(Seconds(1)),
                          MakeTimeAccessor(&DsrRouting::m_minLifeTime),
                          MakeTimeChecker())
            .AddAttribute("UseExtends",
                          "The extension time for link cache",
                          TimeValue(Seconds(120)),
                          MakeTimeAccessor(&DsrRouting::m_useExtends),
                          MakeTimeChecker())
            .AddAttribute("EnableSubRoute",
                          "Enables saving of sub route when receiving "
                          "route error messages, only available when "
                          "using path route cache",
                          BooleanValue(true),
                          MakeBooleanAccessor(&DsrRouting::m_subRoute),
                          MakeBooleanChecker())
            .AddAttribute("RetransIncr",
                          "The increase time for retransmission timer "
                          "when facing network congestion",
                          TimeValue(MilliSeconds(20)),
                          MakeTimeAccessor(&DsrRouting::m_retransIncr),
                          MakeTimeChecker())
            .AddAttribute("MaxNetworkQueueSize",
                          "The max number of packet to save in the network queue.",
                          UintegerValue(400),
                          MakeUintegerAccessor(&DsrRouting::m_maxNetworkSize),
                          MakeUintegerChecker<uint32_t>())
            .AddAttribute("MaxNetworkQueueDelay",
                          "The max time for a packet to stay in the network queue.",
                          TimeValue(Seconds(30.0)),
                          MakeTimeAccessor(&DsrRouting::m_maxNetworkDelay),
                          MakeTimeChecker())
            .AddAttribute("NumPriorityQueues",
                          "The max number of packet to save in the network queue.",
                          UintegerValue(2),
                          MakeUintegerAccessor(&DsrRouting::m_numPriorityQueues),
                          MakeUintegerChecker<uint32_t>())
            .AddAttribute("LinkAcknowledgment",
                          "Enable Link layer acknowledgment mechanism",
                          BooleanValue(true),
                          MakeBooleanAccessor(&DsrRouting::m_linkAck),
                          MakeBooleanChecker())
            .AddTraceSource("Tx",
                            "Send DSR packet.",
                            MakeTraceSourceAccessor(&DsrRouting::m_txPacketTrace),
                            "ns3::dsr::DsrOptionSRHeader::TracedCallback")
            .AddTraceSource("Drop",
                            "Drop DSR packet",
                            MakeTraceSourceAccessor(&DsrRouting::m_dropTrace),
                            "ns3::Packet::TracedCallback");
    return tid;
}

DsrRouting::DsrRouting()
{
    NS_LOG_FUNCTION_NOARGS();

    m_uniformRandomVariable = CreateObject<UniformRandomVariable>();

    /*
     * The following Ptr statements created objects for all the options header for DSR, and each of
     * them have distinct option number assigned, when DSR Routing received a packet from higher
     * layer, it will find the following options based on the option number, and pass the packet to
     * the appropriate option to process it. After the option processing, it will pass the packet
     * back to DSR Routing to send down layer.
     */
    Ptr<dsr::DsrOptionPad1> pad1Option = CreateObject<dsr::DsrOptionPad1>();
    Ptr<dsr::DsrOptionPadn> padnOption = CreateObject<dsr::DsrOptionPadn>();
    Ptr<dsr::DsrOptionRreq> rreqOption = CreateObject<dsr::DsrOptionRreq>();
    Ptr<dsr::DsrOptionRrep> rrepOption = CreateObject<dsr::DsrOptionRrep>();
    Ptr<dsr::DsrOptionSR> srOption = CreateObject<dsr::DsrOptionSR>();
    Ptr<dsr::DsrOptionRerr> rerrOption = CreateObject<dsr::DsrOptionRerr>();
    Ptr<dsr::DsrOptionAckReq> ackReq = CreateObject<dsr::DsrOptionAckReq>();
    Ptr<dsr::DsrOptionAck> ack = CreateObject<dsr::DsrOptionAck>();

    Insert(pad1Option);
    Insert(padnOption);
    Insert(rreqOption);
    Insert(rrepOption);
    Insert(srOption);
    Insert(rerrOption);
    Insert(ackReq);
    Insert(ack);

    // Check the send buffer for sending packets
    m_sendBuffTimer.SetFunction(&DsrRouting::SendBuffTimerExpire, this);
    m_sendBuffTimer.Schedule(Seconds(100));
}

DsrRouting::~DsrRouting()
{
    NS_LOG_FUNCTION_NOARGS();
}

void
DsrRouting::NotifyNewAggregate()
{
    NS_LOG_FUNCTION(this << "NotifyNewAggregate");
    if (!m_node)
    {
        Ptr<Node> node = this->GetObject<Node>();
        if (node)
        {
            m_ipv4 = this->GetObject<Ipv4L3Protocol>();
            if (m_ipv4)
            {
                this->SetNode(node);
                m_ipv4->Insert(this);
                this->SetDownTarget(MakeCallback(&Ipv4L3Protocol::Send, m_ipv4));
            }

            m_ip = node->GetObject<Ipv4>();
            if (m_ip)
            {
                NS_LOG_DEBUG("Ipv4 started");
            }
        }
    }
    IpL4Protocol::NotifyNewAggregate();
    Simulator::ScheduleNow(&DsrRouting::Start, this);
}

void
DsrRouting::Start()
{
    NS_LOG_FUNCTION(this << "Start DSR Routing protocol");

    NS_LOG_INFO("The number of network queues " << m_numPriorityQueues);
    for (uint32_t i = 0; i < m_numPriorityQueues; i++)
    {
        // Set the network queue max size and the delay
        NS_LOG_INFO("The network queue size " << m_maxNetworkSize << " and the queue delay "
                                              << m_maxNetworkDelay.As(Time::S));
        Ptr<dsr::DsrNetworkQueue> queue_i =
            CreateObject<dsr::DsrNetworkQueue>(m_maxNetworkSize, m_maxNetworkDelay);
        auto result_i = m_priorityQueue.insert(std::make_pair(i, queue_i));
        NS_ASSERT_MSG(result_i.second, "Error in creating queues");
    }
    Ptr<dsr::DsrRreqTable> rreqTable = CreateObject<dsr::DsrRreqTable>();
    // Set the initial hop limit
    rreqTable->SetInitHopLimit(m_discoveryHopLimit);
    // Configure the request table parameters
    rreqTable->SetRreqTableSize(m_requestTableSize);
    rreqTable->SetRreqIdSize(m_requestTableIds);
    rreqTable->SetUniqueRreqIdSize(m_maxRreqId);
    SetRequestTable(rreqTable);
    // Set the passive buffer parameters using just the send buffer parameters
    Ptr<dsr::DsrPassiveBuffer> passiveBuffer = CreateObject<dsr::DsrPassiveBuffer>();
    passiveBuffer->SetMaxQueueLen(m_maxSendBuffLen);
    passiveBuffer->SetPassiveBufferTimeout(m_sendBufferTimeout);
    SetPassiveBuffer(passiveBuffer);

    // Set the send buffer parameters
    m_sendBuffer.SetMaxQueueLen(m_maxSendBuffLen);
    m_sendBuffer.SetSendBufferTimeout(m_sendBufferTimeout);
    // Set the error buffer parameters using just the send buffer parameters
    m_errorBuffer.SetMaxQueueLen(m_maxSendBuffLen);
    m_errorBuffer.SetErrorBufferTimeout(m_sendBufferTimeout);
    // Set the maintenance buffer parameters
    m_maintainBuffer.SetMaxQueueLen(m_maxMaintainLen);
    m_maintainBuffer.SetMaintainBufferTimeout(m_maxMaintainTime);
    // Set the gratuitous reply table size
    m_graReply.SetGraTableSize(m_graReplyTableSize);

    if (m_mainAddress == Ipv4Address())
    {
        Ipv4Address loopback("127.0.0.1");
        for (uint32_t i = 0; i < m_ipv4->GetNInterfaces(); i++)
        {
            // Use primary address, if multiple
            Ipv4Address addr = m_ipv4->GetAddress(i, 0).GetLocal();
            m_broadcast = m_ipv4->GetAddress(i, 0).GetBroadcast();
            if (addr != loopback)
            {
                /*
                 * Set dsr route cache
                 */
                Ptr<dsr::DsrRouteCache> routeCache = CreateObject<dsr::DsrRouteCache>();
                // Configure the path cache parameters
                routeCache->SetCacheType(m_cacheType);
                routeCache->SetSubRoute(m_subRoute);
                routeCache->SetMaxCacheLen(m_maxCacheLen);
                routeCache->SetCacheTimeout(m_maxCacheTime);
                routeCache->SetMaxEntriesEachDst(m_maxEntriesEachDst);
                // Parameters for link cache
                routeCache->SetStabilityDecrFactor(m_stabilityDecrFactor);
                routeCache->SetStabilityIncrFactor(m_stabilityIncrFactor);
                routeCache->SetInitStability(m_initStability);
                routeCache->SetMinLifeTime(m_minLifeTime);
                routeCache->SetUseExtends(m_useExtends);
                routeCache->ScheduleTimer();
                // The call back to handle link error and send error message to appropriate nodes
                /// TODO whether this SendRerrWhenBreaksLinkToNextHop is used or not
                // routeCache->SetCallback (MakeCallback
                // (&DsrRouting::SendRerrWhenBreaksLinkToNextHop, this));
                SetRouteCache(routeCache);
                // Set the main address as the current ip address
                m_mainAddress = addr;

                m_ipv4->GetNetDevice(1)->SetPromiscReceiveCallback(
                    MakeCallback(&DsrRouting::PromiscReceive, this));

                // Allow neighbor manager use this interface for layer 2 feedback if possible
                Ptr<NetDevice> dev = m_ipv4->GetNetDevice(m_ipv4->GetInterfaceForAddress(addr));
                Ptr<WifiNetDevice> wifi = dev->GetObject<WifiNetDevice>();
                if (!wifi)
                {
                    break;
                }
                Ptr<WifiMac> mac = wifi->GetMac();
                if (!mac)
                {
                    break;
                }

                routeCache->AddArpCache(m_ipv4->GetInterface(i)->GetArpCache());
                NS_LOG_LOGIC("Starting DSR on node " << m_mainAddress);
                break;
            }
        }
        NS_ASSERT(m_mainAddress != Ipv4Address() && m_broadcast != Ipv4Address());
    }
}

Ptr<NetDevice>
DsrRouting::GetNetDeviceFromContext(std::string context)
{
    // Use "NodeList/*/DeviceList/*/ as reference
    // where element [1] is the Node Id
    // element [2] is the NetDevice Id
    std::vector<std::string> elements = GetElementsFromContext(context);
    Ptr<Node> n = NodeList::GetNode(std::stoi(elements[1]));
    NS_ASSERT(n);
    return n->GetDevice(std::stoi(elements[3]));
}

std::vector<std::string>
DsrRouting::GetElementsFromContext(std::string context)
{
    std::vector<std::string> elements;
    size_t pos1 = 0;
    size_t pos2;
    while (pos1 != std::string::npos)
    {
        pos1 = context.find('/', pos1);
        pos2 = context.find('/', pos1 + 1);
        elements.push_back(context.substr(pos1 + 1, pos2 - (pos1 + 1)));
        pos1 = pos2;
    }
    return elements;
}

void
DsrRouting::DoDispose()
{
    NS_LOG_FUNCTION_NOARGS();
    m_node = nullptr;
    for (uint32_t i = 0; i < m_ipv4->GetNInterfaces(); i++)
    {
        // Disable layer 2 link state monitoring (if possible)
        Ptr<NetDevice> dev = m_ipv4->GetNetDevice(i);
        Ptr<WifiNetDevice> wifi = dev->GetObject<WifiNetDevice>();
        if (wifi)
        {
            Ptr<WifiMac> mac = wifi->GetMac();
            if (mac)
            {
                Ptr<AdhocWifiMac> adhoc = mac->GetObject<AdhocWifiMac>();
                if (adhoc)
                {
                    m_routeCache->DelArpCache(m_ipv4->GetInterface(i)->GetArpCache());
                }
            }
        }
    }
    IpL4Protocol::DoDispose();
}

void
DsrRouting::SetNode(Ptr<Node> node)
{
    m_node = node;
}

Ptr<Node>
DsrRouting::GetNode() const
{
    NS_LOG_FUNCTION_NOARGS();
    return m_node;
}

void
DsrRouting::SetRouteCache(Ptr<dsr::DsrRouteCache> r)
{
    // / Set the route cache to use
    m_routeCache = r;
}

Ptr<dsr::DsrRouteCache>
DsrRouting::GetRouteCache() const
{
    // / Get the route cache to use
    return m_routeCache;
}

void
DsrRouting::SetRequestTable(Ptr<dsr::DsrRreqTable> q)
{
    // / Set the request table to use
    m_rreqTable = q;
}

Ptr<dsr::DsrRreqTable>
DsrRouting::GetRequestTable() const
{
    // / Get the request table to use
    return m_rreqTable;
}

void
DsrRouting::SetPassiveBuffer(Ptr<dsr::DsrPassiveBuffer> p)
{
    // / Set the request table to use
    m_passiveBuffer = p;
}

Ptr<dsr::DsrPassiveBuffer>
DsrRouting::GetPassiveBuffer() const
{
    // / Get the request table to use
    return m_passiveBuffer;
}

Ptr<Node>
DsrRouting::GetNodeWithAddress(Ipv4Address ipv4Address)
{
    NS_LOG_FUNCTION(this << ipv4Address);
    int32_t nNodes = NodeList::GetNNodes();
    for (int32_t i = 0; i < nNodes; ++i)
    {
        Ptr<Node> node = NodeList::GetNode(i);
        Ptr<Ipv4> ipv4 = node->GetObject<Ipv4>();
        int32_t ifIndex = ipv4->GetInterfaceForAddress(ipv4Address);
        if (ifIndex != -1)
        {
            return node;
        }
    }
    return nullptr;
}

bool
DsrRouting::IsLinkCache()
{
    return m_routeCache->IsLinkCache();
}

void
DsrRouting::UseExtends(DsrRouteCacheEntry::IP_VECTOR rt)
{
    m_routeCache->UseExtends(rt);
}

bool
DsrRouting::LookupRoute(Ipv4Address id, DsrRouteCacheEntry& rt)
{
    return m_routeCache->LookupRoute(id, rt);
}

bool
DsrRouting::AddRoute_Link(DsrRouteCacheEntry::IP_VECTOR nodelist, Ipv4Address source)
{
    Ipv4Address nextHop = SearchNextHop(source, nodelist);
    m_errorBuffer.DropPacketForErrLink(source, nextHop);
    return m_routeCache->AddRoute_Link(nodelist, source);
}

bool
DsrRouting::AddRoute(DsrRouteCacheEntry& rt)
{
    std::vector<Ipv4Address> nodelist = rt.GetVector();
    Ipv4Address nextHop = SearchNextHop(m_mainAddress, nodelist);
    m_errorBuffer.DropPacketForErrLink(m_mainAddress, nextHop);
    return m_routeCache->AddRoute(rt);
}

void
DsrRouting::DeleteAllRoutesIncludeLink(Ipv4Address errorSrc,
                                       Ipv4Address unreachNode,
                                       Ipv4Address node)
{
    m_routeCache->DeleteAllRoutesIncludeLink(errorSrc, unreachNode, node);
}

bool
DsrRouting::UpdateRouteEntry(Ipv4Address dst)
{
    return m_routeCache->UpdateRouteEntry(dst);
}

bool
DsrRouting::FindSourceEntry(Ipv4Address src, Ipv4Address dst, uint16_t id)
{
    return m_rreqTable->FindSourceEntry(src, dst, id);
}

Ipv4Address
DsrRouting::GetIPfromMAC(Mac48Address address)
{
    NS_LOG_FUNCTION(this << address);
    int32_t nNodes = NodeList::GetNNodes();
    for (int32_t i = 0; i < nNodes; ++i)
    {
        Ptr<Node> node = NodeList::GetNode(i);
        Ptr<Ipv4> ipv4 = node->GetObject<Ipv4>();
        Ptr<NetDevice> netDevice = ipv4->GetNetDevice(1);

        if (netDevice->GetAddress() == address)
        {
            return ipv4->GetAddress(1, 0).GetLocal();
        }
    }
    return nullptr;
}

void
DsrRouting::PrintVector(std::vector<Ipv4Address>& vec)
{
    NS_LOG_FUNCTION(this);
    /*
     * Check elements in a route vector
     */
    if (vec.empty())
    {
        NS_LOG_DEBUG("The vector is empty");
    }
    else
    {
        NS_LOG_DEBUG("Print all the elements in a vector");
        for (auto i = vec.begin(); i != vec.end(); ++i)
        {
            NS_LOG_DEBUG("The ip address " << *i);
        }
    }
}

Ipv4Address
DsrRouting::SearchNextHop(Ipv4Address ipv4Address, std::vector<Ipv4Address>& vec)
{
    NS_LOG_FUNCTION(this << ipv4Address);
    Ipv4Address nextHop;
    NS_LOG_DEBUG("the vector size " << vec.size());
    if (vec.size() == 2)
    {
        NS_LOG_DEBUG("The two nodes are neighbors");
        nextHop = vec[1];
        return nextHop;
    }

    if (ipv4Address == vec.back())
    {
        NS_LOG_DEBUG("We have reached to the final destination " << ipv4Address << " "
                                                                 << vec.back());
        return ipv4Address;
    }
    for (auto i = vec.begin(); i != vec.end(); ++i)
    {
        if (ipv4Address == (*i))
        {
            nextHop = *(++i);
            return nextHop;
        }
    }

    NS_LOG_DEBUG("Next hop address not found");
    Ipv4Address none = "0.0.0.0";
    return none;
}

Ptr<Ipv4Route>
DsrRouting::SetRoute(Ipv4Address nextHop, Ipv4Address srcAddress)
{
    NS_LOG_FUNCTION(this << nextHop << srcAddress);
    m_ipv4Route = Create<Ipv4Route>();
    m_ipv4Route->SetDestination(nextHop);
    m_ipv4Route->SetGateway(nextHop);
    m_ipv4Route->SetSource(srcAddress);
    return m_ipv4Route;
}

int
DsrRouting::GetProtocolNumber() const
{
    // / This is the protocol number for DSR which is 48
    return PROT_NUMBER;
}

uint16_t
DsrRouting::GetIDfromIP(Ipv4Address address)
{
    int32_t nNodes = NodeList::GetNNodes();
    for (int32_t i = 0; i < nNodes; ++i)
    {
        Ptr<Node> node = NodeList::GetNode(i);
        Ptr<Ipv4> ipv4 = node->GetObject<Ipv4>();
        if (ipv4->GetAddress(1, 0).GetLocal() == address)
        {
            return uint16_t(i);
        }
    }
    return 256;
}

Ipv4Address
DsrRouting::GetIPfromID(uint16_t id)
{
    if (id >= 256)
    {
        NS_LOG_DEBUG("Exceed the node range");
        return "0.0.0.0";
    }

    Ptr<Node> node = NodeList::GetNode(uint32_t(id));
    Ptr<Ipv4> ipv4 = node->GetObject<Ipv4>();
    return ipv4->GetAddress(1, 0).GetLocal();
}

uint32_t
DsrRouting::GetPriority(DsrMessageType messageType)
{
    if (messageType == DSR_CONTROL_PACKET)
    {
        return 0;
    }
    else
    {
        return 1;
    }
}

void
DsrRouting::SendBuffTimerExpire()
{
    if (m_sendBuffTimer.IsRunning())
    {
        m_sendBuffTimer.Cancel();
    }
    m_sendBuffTimer.Schedule(m_sendBuffInterval);
    CheckSendBuffer();
}

void
DsrRouting::CheckSendBuffer()
{
    NS_LOG_INFO(Simulator::Now().As(Time::S) << " Checking send buffer at " << m_mainAddress
                                             << " with size " << m_sendBuffer.GetSize());

    for (auto i = m_sendBuffer.GetBuffer().begin(); i != m_sendBuffer.GetBuffer().end();)
    {
        NS_LOG_DEBUG("Here we try to find the data packet in the send buffer");
        Ipv4Address destination = i->GetDestination();
        DsrRouteCacheEntry toDst;
        bool findRoute = m_routeCache->LookupRoute(destination, toDst);
        if (findRoute)
        {
            NS_LOG_INFO("We have found a route for the packet");
            Ptr<const Packet> packet = i->GetPacket();
            Ptr<Packet> cleanP = packet->Copy();
            uint8_t protocol = i->GetProtocol();

            i = m_sendBuffer.GetBuffer().erase(i);

            DsrRoutingHeader dsrRoutingHeader;
            Ptr<Packet> copyP = packet->Copy();
            Ptr<Packet> dsrPacket = packet->Copy();
            dsrPacket->RemoveHeader(dsrRoutingHeader);
            uint32_t offset = dsrRoutingHeader.GetDsrOptionsOffset();
            copyP->RemoveAtStart(offset); // Here the processed size is 8 bytes, which is the fixed
                                          // sized extension header
            // The packet to get ipv4 header
            Ptr<Packet> ipv4P = copyP->Copy();
            /*
             * Peek data to get the option type as well as length and segmentsLeft field
             */
            uint32_t size = copyP->GetSize();
            auto data = new uint8_t[size];
            copyP->CopyData(data, size);

            uint8_t optionType = 0;
            optionType = *(data);

            if (optionType == 3)
            {
                Ptr<dsr::DsrOptions> dsrOption;
                DsrOptionHeader dsrOptionHeader;
                uint8_t errorType = *(data + 2);

                if (errorType == 1) // This is the Route Error Option
                {
                    DsrOptionRerrUnreachHeader rerr;
                    copyP->RemoveHeader(rerr);
                    NS_ASSERT(copyP->GetSize() == 0);

                    DsrOptionRerrUnreachHeader newUnreach;
                    newUnreach.SetErrorType(1);
                    newUnreach.SetErrorSrc(rerr.GetErrorSrc());
                    newUnreach.SetUnreachNode(rerr.GetUnreachNode());
                    newUnreach.SetErrorDst(rerr.GetErrorDst());
                    newUnreach.SetSalvage(rerr.GetSalvage()); // Set the value about whether to
                                                              // salvage a packet or not

                    DsrOptionSRHeader sourceRoute;
                    std::vector<Ipv4Address> errorRoute = toDst.GetVector();
                    sourceRoute.SetNodesAddress(errorRoute);
                    /// When found a route and use it, UseExtends to the link cache
                    if (m_routeCache->IsLinkCache())
                    {
                        m_routeCache->UseExtends(errorRoute);
                    }
                    sourceRoute.SetSegmentsLeft(errorRoute.size() - 2);
                    uint8_t salvage = 0;
                    sourceRoute.SetSalvage(salvage);
                    Ipv4Address nextHop =
                        SearchNextHop(m_mainAddress, errorRoute); // Get the next hop address

                    if (nextHop == "0.0.0.0")
                    {
                        PacketNewRoute(dsrPacket, m_mainAddress, destination, protocol);
                        return;
                    }

                    SetRoute(nextHop, m_mainAddress);
                    uint8_t length = (sourceRoute.GetLength() + newUnreach.GetLength());
                    dsrRoutingHeader.SetNextHeader(protocol);
                    dsrRoutingHeader.SetMessageType(1);
                    dsrRoutingHeader.SetSourceId(GetIDfromIP(m_mainAddress));
                    dsrRoutingHeader.SetDestId(255);
                    dsrRoutingHeader.SetPayloadLength(uint16_t(length) + 4);
                    dsrRoutingHeader.AddDsrOption(newUnreach);
                    dsrRoutingHeader.AddDsrOption(sourceRoute);

                    Ptr<Packet> newPacket = Create<Packet>();
                    newPacket->AddHeader(dsrRoutingHeader); // Add the routing header with rerr and
                                                            // sourceRoute attached to it
                    Ptr<NetDevice> dev =
                        m_ip->GetNetDevice(m_ip->GetInterfaceForAddress(m_mainAddress));
                    m_ipv4Route->SetOutputDevice(dev);

                    uint32_t priority = GetPriority(DSR_CONTROL_PACKET); /// This will be priority 0
                    auto i = m_priorityQueue.find(priority);
                    Ptr<dsr::DsrNetworkQueue> dsrNetworkQueue = i->second;
                    NS_LOG_LOGIC("Will be inserting into priority queue number: " << priority);

                    // m_downTarget (newPacket, m_mainAddress, nextHop, GetProtocolNumber (),
                    // m_ipv4Route);

                    /// \todo New DsrNetworkQueueEntry
                    DsrNetworkQueueEntry newEntry(newPacket,
                                                  m_mainAddress,
                                                  nextHop,
                                                  Simulator::Now(),
                                                  m_ipv4Route);

                    if (dsrNetworkQueue->Enqueue(newEntry))
                    {
                        Scheduler(priority);
                    }
                    else
                    {
                        NS_LOG_INFO("Packet dropped as dsr network queue is full");
                    }
                }
            }
            else
            {
                dsrRoutingHeader.SetNextHeader(protocol);
                dsrRoutingHeader.SetMessageType(2);
                dsrRoutingHeader.SetSourceId(GetIDfromIP(m_mainAddress));
                dsrRoutingHeader.SetDestId(GetIDfromIP(destination));

                DsrOptionSRHeader sourceRoute;
                std::vector<Ipv4Address> nodeList =
                    toDst.GetVector(); // Get the route from the route entry we found
                Ipv4Address nextHop =
                    SearchNextHop(m_mainAddress,
                                  nodeList); // Get the next hop address for the route
                if (nextHop == "0.0.0.0")
                {
                    PacketNewRoute(dsrPacket, m_mainAddress, destination, protocol);
                    return;
                }
                uint8_t salvage = 0;
                // Save the whole route in the source route header of the packet
                sourceRoute.SetNodesAddress(nodeList);
                // The segmentsLeft field will indicate the hops to go
                sourceRoute.SetSegmentsLeft(nodeList.size() - 2);
                sourceRoute.SetSalvage(salvage);
                // When found a route and use it, UseExtends to the link cache
                if (m_routeCache->IsLinkCache())
                {
                    m_routeCache->UseExtends(nodeList);
                }
                uint8_t length = sourceRoute.GetLength();
                dsrRoutingHeader.SetPayloadLength(uint16_t(length) + 2);
                dsrRoutingHeader.AddDsrOption(sourceRoute);
                cleanP->AddHeader(dsrRoutingHeader);
                Ptr<const Packet> mtP = cleanP->Copy();
                // Put the data packet in the maintenance queue for data packet retransmission
                DsrMaintainBuffEntry newEntry(/*packet=*/mtP,
                                              /*ourAddress=*/m_mainAddress,
                                              /*nextHop=*/nextHop,
                                              /*src=*/m_mainAddress,
                                              /*dst=*/destination,
                                              /*ackId=*/0,
                                              /*segsLeft=*/nodeList.size() - 2,
                                              /*expire=*/m_maxMaintainTime);
                bool result = m_maintainBuffer.Enqueue(
                    newEntry); // Enqueue the packet the the maintenance buffer
                if (result)
                {
                    NetworkKey networkKey;
                    networkKey.m_ackId = newEntry.GetAckId();
                    networkKey.m_ourAdd = newEntry.GetOurAdd();
                    networkKey.m_nextHop = newEntry.GetNextHop();
                    networkKey.m_source = newEntry.GetSrc();
                    networkKey.m_destination = newEntry.GetDst();

                    PassiveKey passiveKey;
                    passiveKey.m_ackId = 0;
                    passiveKey.m_source = newEntry.GetSrc();
                    passiveKey.m_destination = newEntry.GetDst();
                    passiveKey.m_segsLeft = newEntry.GetSegsLeft();

                    LinkKey linkKey;
                    linkKey.m_source = newEntry.GetSrc();
                    linkKey.m_destination = newEntry.GetDst();
                    linkKey.m_ourAdd = newEntry.GetOurAdd();
                    linkKey.m_nextHop = newEntry.GetNextHop();

                    m_addressForwardCnt[networkKey] = 0;
                    m_passiveCnt[passiveKey] = 0;
                    m_linkCnt[linkKey] = 0;

                    if (m_linkAck)
                    {
                        ScheduleLinkPacketRetry(newEntry, protocol);
                    }
                    else
                    {
                        NS_LOG_LOGIC("Not using link acknowledgment");
                        if (nextHop != destination)
                        {
                            SchedulePassivePacketRetry(newEntry, protocol);
                        }
                        else
                        {
                            // This is the first network retry
                            ScheduleNetworkPacketRetry(newEntry, true, protocol);
                        }
                    }
                }
                // we need to suspend the normal timer that checks the send buffer
                // until we are done sending packets
                if (!m_sendBuffTimer.IsSuspended())
                {
                    m_sendBuffTimer.Suspend();
                }
                Simulator::Schedule(m_sendBuffInterval, &DsrRouting::SendBuffTimerExpire, this);
                return;
            }
        }
        else
        {
            ++i;
        }
    }
    // after going through the entire send buffer and send all packets found route,
    // we need to resume the timer if it has been suspended
    if (m_sendBuffTimer.IsSuspended())
    {
        NS_LOG_DEBUG("Resume the send buffer timer");
        m_sendBuffTimer.Resume();
    }
}

bool
DsrRouting::PromiscReceive(Ptr<NetDevice> device,
                           Ptr<const Packet> packet,
                           uint16_t protocol,
                           const Address& from,
                           const Address& to,
                           NetDevice::PacketType packetType)
{
    if (protocol != Ipv4L3Protocol::PROT_NUMBER)
    {
        return false;
    }
    // Remove the ipv4 header here
    Ptr<Packet> pktMinusIpHdr = packet->Copy();
    Ipv4Header ipv4Header;
    pktMinusIpHdr->RemoveHeader(ipv4Header);

    if (ipv4Header.GetProtocol() != DsrRouting::PROT_NUMBER)
    {
        return false;
    }
    // Remove the dsr routing header here
    Ptr<Packet> pktMinusDsrHdr = pktMinusIpHdr->Copy();
    DsrRoutingHeader dsrRouting;
    pktMinusDsrHdr->RemoveHeader(dsrRouting);

    /*
     * Message type 2 means the data packet, we will further process the data
     * packet for delivery notification, safely ignore control packet
     * Another check here is our own address, if this is the data destined for us,
     * process it further, otherwise, just ignore it
     */
    Ipv4Address ourAddress = m_ipv4->GetAddress(1, 0).GetLocal();
    // check if the message type is 2 and if the ipv4 address matches
    if (dsrRouting.GetMessageType() == 2 && ourAddress == m_mainAddress)
    {
        NS_LOG_DEBUG("data packet receives " << packet->GetUid());
        Ipv4Address sourceIp = GetIPfromID(dsrRouting.GetSourceId());
        Ipv4Address destinationIp = GetIPfromID(dsrRouting.GetDestId());
        /// This is the ip address we just received data packet from
        Ipv4Address previousHop = GetIPfromMAC(Mac48Address::ConvertFrom(from));

        Ptr<Packet> p = Create<Packet>();
        // Here the segments left value need to plus one to check the earlier hop maintain buffer
        // entry
        DsrMaintainBuffEntry newEntry;
        newEntry.SetPacket(p);
        newEntry.SetSrc(sourceIp);
        newEntry.SetDst(destinationIp);
        /// Remember this is the entry for previous node
        newEntry.SetOurAdd(previousHop);
        newEntry.SetNextHop(ourAddress);
        /// Get the previous node's maintenance buffer and passive ack
        Ptr<Node> node = GetNodeWithAddress(previousHop);
        NS_LOG_DEBUG("The previous node " << previousHop);

        Ptr<dsr::DsrRouting> dsr = node->GetObject<dsr::DsrRouting>();
        dsr->CancelLinkPacketTimer(newEntry);
    }

    // Receive only IP packets and packets destined for other hosts
    if (packetType == NetDevice::PACKET_OTHERHOST)
    {
        // just to minimize debug output
        NS_LOG_INFO(this << from << to << packetType << *pktMinusIpHdr);

        uint8_t offset =
            dsrRouting
                .GetDsrOptionsOffset(); // Get the offset for option header, 4 bytes in this case
        uint8_t nextHeader = dsrRouting.GetNextHeader();
        uint32_t sourceId = dsrRouting.GetSourceId();
        Ipv4Address source = GetIPfromID(sourceId);

        // This packet is used to peek option type
        pktMinusIpHdr->RemoveAtStart(offset);
        /*
         * Peek data to get the option type as well as length and segmentsLeft field
         */
        uint32_t size = pktMinusIpHdr->GetSize();
        auto data = new uint8_t[size];
        pktMinusIpHdr->CopyData(data, size);
        uint8_t optionType = 0;
        optionType = *(data);

        Ptr<dsr::DsrOptions> dsrOption;

        if (optionType == 96) // This is the source route option
        {
            Ipv4Address promiscSource = GetIPfromMAC(Mac48Address::ConvertFrom(from));
            dsrOption = GetOption(
                optionType); // Get the relative DSR option and demux to the process function
            NS_LOG_DEBUG(Simulator::Now().As(Time::S)
                         << " DSR node " << m_mainAddress
                         << " overhearing packet PID: " << pktMinusIpHdr->GetUid() << " from "
                         << promiscSource << " to " << GetIPfromMAC(Mac48Address::ConvertFrom(to))
                         << " with source IP " << ipv4Header.GetSource() << " and destination IP "
                         << ipv4Header.GetDestination() << " and packet : " << *pktMinusDsrHdr);

            bool isPromisc = true; // Set the boolean value isPromisc as true
            dsrOption->Process(pktMinusIpHdr,
                               pktMinusDsrHdr,
                               m_mainAddress,
                               source,
                               ipv4Header,
                               nextHeader,
                               isPromisc,
                               promiscSource);
            return true;
        }
    }
    return false;
}

void
DsrRouting::PacketNewRoute(Ptr<Packet> packet,
                           Ipv4Address source,
                           Ipv4Address destination,
                           uint8_t protocol)
{
    NS_LOG_FUNCTION(this << packet << source << destination << (uint32_t)protocol);
    // Look up routes for the specific destination
    DsrRouteCacheEntry toDst;
    bool findRoute = m_routeCache->LookupRoute(destination, toDst);
    // Queue the packet if there is no route pre-existing
    if (!findRoute)
    {
        NS_LOG_INFO(Simulator::Now().As(Time::S)
                    << " " << m_mainAddress
                    << " there is no route for this packet, queue the packet");

        Ptr<Packet> p = packet->Copy();
        DsrSendBuffEntry newEntry(p,
                                  destination,
                                  m_sendBufferTimeout,
                                  protocol);          // Create a new entry for send buffer
        bool result = m_sendBuffer.Enqueue(newEntry); // Enqueue the packet in send buffer
        if (result)
        {
            NS_LOG_INFO(Simulator::Now().As(Time::S) << " Add packet PID: " << packet->GetUid()
                                                     << " to queue. Packet: " << *packet);

            NS_LOG_LOGIC("Send RREQ to" << destination);
            if ((m_addressReqTimer.find(destination) == m_addressReqTimer.end()) &&
                (m_nonPropReqTimer.find(destination) == m_nonPropReqTimer.end()))
            {
                /*
                 * Call the send request function, it will update the request table entry and ttl
                 * there
                 */
                SendInitialRequest(source, destination, protocol);
            }
        }
    }
    else
    {
        Ptr<Packet> cleanP = packet->Copy();
        DsrRoutingHeader dsrRoutingHeader;
        dsrRoutingHeader.SetNextHeader(protocol);
        dsrRoutingHeader.SetMessageType(2);
        dsrRoutingHeader.SetSourceId(GetIDfromIP(source));
        dsrRoutingHeader.SetDestId(GetIDfromIP(destination));

        DsrOptionSRHeader sourceRoute;
        std::vector<Ipv4Address> nodeList =
            toDst.GetVector(); // Get the route from the route entry we found
        Ipv4Address nextHop =
            SearchNextHop(m_mainAddress, nodeList); // Get the next hop address for the route
        if (nextHop == "0.0.0.0")
        {
            PacketNewRoute(cleanP, source, destination, protocol);
            return;
        }
        uint8_t salvage = 0;
        sourceRoute.SetNodesAddress(
            nodeList); // Save the whole route in the source route header of the packet
        /// When found a route and use it, UseExtends to the link cache
        if (m_routeCache->IsLinkCache())
        {
            m_routeCache->UseExtends(nodeList);
        }
        // The segmentsLeft field will indicate the hops to go
        sourceRoute.SetSegmentsLeft(nodeList.size() - 2);
        sourceRoute.SetSalvage(salvage);

        uint8_t length = sourceRoute.GetLength();
        dsrRoutingHeader.SetPayloadLength(uint16_t(length) + 2);
        dsrRoutingHeader.AddDsrOption(sourceRoute);
        cleanP->AddHeader(dsrRoutingHeader);
        Ptr<const Packet> mtP = cleanP->Copy();
        SetRoute(nextHop, m_mainAddress);
        // Put the data packet in the maintenance queue for data packet retransmission
        DsrMaintainBuffEntry newEntry(/*packet=*/mtP,
                                      /*ourAddress=*/m_mainAddress,
                                      /*nextHop=*/nextHop,
                                      /*src=*/source,
                                      /*dst=*/destination,
                                      /*ackId=*/0,
                                      /*segsLeft=*/nodeList.size() - 2,
                                      /*expire=*/m_maxMaintainTime);
        bool result =
            m_maintainBuffer.Enqueue(newEntry); // Enqueue the packet the the maintenance buffer

        if (result)
        {
            NetworkKey networkKey;
            networkKey.m_ackId = newEntry.GetAckId();
            networkKey.m_ourAdd = newEntry.GetOurAdd();
            networkKey.m_nextHop = newEntry.GetNextHop();
            networkKey.m_source = newEntry.GetSrc();
            networkKey.m_destination = newEntry.GetDst();

            PassiveKey passiveKey;
            passiveKey.m_ackId = 0;
            passiveKey.m_source = newEntry.GetSrc();
            passiveKey.m_destination = newEntry.GetDst();
            passiveKey.m_segsLeft = newEntry.GetSegsLeft();

            LinkKey linkKey;
            linkKey.m_source = newEntry.GetSrc();
            linkKey.m_destination = newEntry.GetDst();
            linkKey.m_ourAdd = newEntry.GetOurAdd();
            linkKey.m_nextHop = newEntry.GetNextHop();

            m_addressForwardCnt[networkKey] = 0;
            m_passiveCnt[passiveKey] = 0;
            m_linkCnt[linkKey] = 0;

            if (m_linkAck)
            {
                ScheduleLinkPacketRetry(newEntry, protocol);
            }
            else
            {
                NS_LOG_LOGIC("Not using link acknowledgment");
                if (nextHop != destination)
                {
                    SchedulePassivePacketRetry(newEntry, protocol);
                }
                else
                {
                    // This is the first network retry
                    ScheduleNetworkPacketRetry(newEntry, true, protocol);
                }
            }
        }
    }
}

void
DsrRouting::SendUnreachError(Ipv4Address unreachNode,
                             Ipv4Address destination,
                             Ipv4Address originalDst,
                             uint8_t salvage,
                             uint8_t protocol)
{
    NS_LOG_FUNCTION(this << unreachNode << destination << originalDst << (uint32_t)salvage
                         << (uint32_t)protocol);
    DsrRoutingHeader dsrRoutingHeader;
    dsrRoutingHeader.SetNextHeader(protocol);
    dsrRoutingHeader.SetMessageType(1);
    dsrRoutingHeader.SetSourceId(GetIDfromIP(m_mainAddress));
    dsrRoutingHeader.SetDestId(GetIDfromIP(destination));

    DsrOptionRerrUnreachHeader rerrUnreachHeader;
    rerrUnreachHeader.SetErrorType(1);
    rerrUnreachHeader.SetErrorSrc(m_mainAddress);
    rerrUnreachHeader.SetUnreachNode(unreachNode);
    rerrUnreachHeader.SetErrorDst(destination);
    rerrUnreachHeader.SetOriginalDst(originalDst);
    rerrUnreachHeader.SetSalvage(salvage); // Set the value about whether to salvage a packet or not
    uint8_t rerrLength = rerrUnreachHeader.GetLength();

    DsrRouteCacheEntry toDst;
    bool findRoute = m_routeCache->LookupRoute(destination, toDst);
    // Queue the packet if there is no route pre-existing
    Ptr<Packet> newPacket = Create<Packet>();
    if (!findRoute)
    {
        if (destination == m_mainAddress)
        {
            NS_LOG_INFO("We are the error source, send request to original dst " << originalDst);
            // Send error request message if we are the source node
            SendErrorRequest(rerrUnreachHeader, protocol);
        }
        else
        {
            NS_LOG_INFO(Simulator::Now().As(Time::S)
                        << " " << m_mainAddress
                        << " there is no route for this packet, queue the packet");

            dsrRoutingHeader.SetPayloadLength(rerrLength + 2);
            dsrRoutingHeader.AddDsrOption(rerrUnreachHeader);
            newPacket->AddHeader(dsrRoutingHeader);
            Ptr<Packet> p = newPacket->Copy();
            // Save the error packet in the error buffer
            DsrErrorBuffEntry newEntry(p,
                                       destination,
                                       m_mainAddress,
                                       unreachNode,
                                       m_sendBufferTimeout,
                                       protocol);
            bool result = m_errorBuffer.Enqueue(newEntry); // Enqueue the packet in send buffer
            if (result)
            {
                NS_LOG_INFO(Simulator::Now().As(Time::S)
                            << " Add packet PID: " << p->GetUid() << " to queue. Packet: " << *p);
                NS_LOG_LOGIC("Send RREQ to" << destination);
                if ((m_addressReqTimer.find(destination) == m_addressReqTimer.end()) &&
                    (m_nonPropReqTimer.find(destination) == m_nonPropReqTimer.end()))
                {
                    NS_LOG_DEBUG("When there is no existing route request for "
                                 << destination << ", initialize one");
                    /*
                     * Call the send request function, it will update the request table entry and
                     * ttl there
                     */
                    SendInitialRequest(m_mainAddress, destination, protocol);
                }
            }
        }
    }
    else
    {
        std::vector<Ipv4Address> nodeList = toDst.GetVector();
        Ipv4Address nextHop = SearchNextHop(m_mainAddress, nodeList);
        if (nextHop == "0.0.0.0")
        {
            NS_LOG_DEBUG("The route is not right");
            PacketNewRoute(newPacket, m_mainAddress, destination, protocol);
            return;
        }
        DsrOptionSRHeader sourceRoute;
        sourceRoute.SetNodesAddress(nodeList);
        /// When found a route and use it, UseExtends to the link cache
        if (m_routeCache->IsLinkCache())
        {
            m_routeCache->UseExtends(nodeList);
        }
        sourceRoute.SetSegmentsLeft(nodeList.size() - 2);
        uint8_t srLength = sourceRoute.GetLength();
        uint8_t length = (srLength + rerrLength);

        dsrRoutingHeader.SetPayloadLength(uint16_t(length) + 4);
        dsrRoutingHeader.AddDsrOption(rerrUnreachHeader);
        dsrRoutingHeader.AddDsrOption(sourceRoute);
        newPacket->AddHeader(dsrRoutingHeader);

        SetRoute(nextHop, m_mainAddress);
        Ptr<NetDevice> dev = m_ip->GetNetDevice(m_ip->GetInterfaceForAddress(m_mainAddress));
        m_ipv4Route->SetOutputDevice(dev);
        NS_LOG_INFO("Send the packet to the next hop address " << nextHop << " from "
                                                               << m_mainAddress << " with the size "
                                                               << newPacket->GetSize());

        uint32_t priority = GetPriority(DSR_CONTROL_PACKET);
        auto i = m_priorityQueue.find(priority);
        Ptr<dsr::DsrNetworkQueue> dsrNetworkQueue = i->second;
        NS_LOG_DEBUG("Will be inserting into priority queue " << dsrNetworkQueue
                                                              << " number: " << priority);

        // m_downTarget (newPacket, m_mainAddress, nextHop, GetProtocolNumber (), m_ipv4Route);

        /// \todo New DsrNetworkQueueEntry
        DsrNetworkQueueEntry newEntry(newPacket,
                                      m_mainAddress,
                                      nextHop,
                                      Simulator::Now(),
                                      m_ipv4Route);

        if (dsrNetworkQueue->Enqueue(newEntry))
        {
            Scheduler(priority);
        }
        else
        {
            NS_LOG_INFO("Packet dropped as dsr network queue is full");
        }
    }
}

void
DsrRouting::ForwardErrPacket(DsrOptionRerrUnreachHeader& rerr,
                             DsrOptionSRHeader& sourceRoute,
                             Ipv4Address nextHop,
                             uint8_t protocol,
                             Ptr<Ipv4Route> route)
{
    NS_LOG_FUNCTION(this << rerr << sourceRoute << nextHop << (uint32_t)protocol << route);
    NS_ASSERT_MSG(!m_downTarget.IsNull(), "Error, DsrRouting cannot send downward");
    DsrRoutingHeader dsrRoutingHeader;
    dsrRoutingHeader.SetNextHeader(protocol);
    dsrRoutingHeader.SetMessageType(1);
    dsrRoutingHeader.SetSourceId(GetIDfromIP(rerr.GetErrorSrc()));
    dsrRoutingHeader.SetDestId(GetIDfromIP(rerr.GetErrorDst()));

    uint8_t length = (sourceRoute.GetLength() + rerr.GetLength());
    dsrRoutingHeader.SetPayloadLength(uint16_t(length) + 4);
    dsrRoutingHeader.AddDsrOption(rerr);
    dsrRoutingHeader.AddDsrOption(sourceRoute);
    Ptr<Packet> packet = Create<Packet>();
    packet->AddHeader(dsrRoutingHeader);
    Ptr<NetDevice> dev = m_ip->GetNetDevice(m_ip->GetInterfaceForAddress(m_mainAddress));
    route->SetOutputDevice(dev);

    uint32_t priority = GetPriority(DSR_CONTROL_PACKET);
    auto i = m_priorityQueue.find(priority);
    Ptr<dsr::DsrNetworkQueue> dsrNetworkQueue = i->second;
    NS_LOG_DEBUG("Will be inserting into priority queue " << dsrNetworkQueue
                                                          << " number: " << priority);

    // m_downTarget (packet, m_mainAddress, nextHop, GetProtocolNumber (), route);

    /// \todo New DsrNetworkQueueEntry
    DsrNetworkQueueEntry newEntry(packet, m_mainAddress, nextHop, Simulator::Now(), route);

    if (dsrNetworkQueue->Enqueue(newEntry))
    {
        Scheduler(priority);
    }
    else
    {
        NS_LOG_INFO("Packet dropped as dsr network queue is full");
    }
}

void
DsrRouting::Send(Ptr<Packet> packet,
                 Ipv4Address source,
                 Ipv4Address destination,
                 uint8_t protocol,
                 Ptr<Ipv4Route> route)
{
    NS_LOG_FUNCTION(this << packet << source << destination << (uint32_t)protocol << route);
    NS_ASSERT_MSG(!m_downTarget.IsNull(), "Error, DsrRouting cannot send downward");

    if (protocol == 1)
    {
        NS_LOG_INFO("Drop packet. Not handling ICMP packet for now");
    }
    else
    {
        // Look up routes for the specific destination
        DsrRouteCacheEntry toDst;
        bool findRoute = m_routeCache->LookupRoute(destination, toDst);
        // Queue the packet if there is no route pre-existing
        if (!findRoute)
        {
            NS_LOG_INFO(Simulator::Now().As(Time::S)
                        << " " << m_mainAddress
                        << " there is no route for this packet, queue the packet");

            Ptr<Packet> p = packet->Copy();
            DsrSendBuffEntry newEntry(p,
                                      destination,
                                      m_sendBufferTimeout,
                                      protocol);          // Create a new entry for send buffer
            bool result = m_sendBuffer.Enqueue(newEntry); // Enqueue the packet in send buffer
            if (result)
            {
                NS_LOG_INFO(Simulator::Now().As(Time::S) << " Add packet PID: " << packet->GetUid()
                                                         << " to send buffer. Packet: " << *packet);
                // Only when there is no existing route request timer when new route request is
                // scheduled
                if ((m_addressReqTimer.find(destination) == m_addressReqTimer.end()) &&
                    (m_nonPropReqTimer.find(destination) == m_nonPropReqTimer.end()))
                {
                    /*
                     * Call the send request function, it will update the request table entry and
                     * ttl value
                     */
                    NS_LOG_LOGIC("Send initial RREQ to " << destination);
                    SendInitialRequest(source, destination, protocol);
                }
                else
                {
                    NS_LOG_LOGIC("There is existing route request timer with request count "
                                 << m_rreqTable->GetRreqCnt(destination));
                }
            }
        }
        else
        {
            Ptr<Packet> cleanP = packet->Copy();
            DsrRoutingHeader dsrRoutingHeader;
            dsrRoutingHeader.SetNextHeader(protocol);
            dsrRoutingHeader.SetMessageType(2);
            dsrRoutingHeader.SetSourceId(GetIDfromIP(source));
            dsrRoutingHeader.SetDestId(GetIDfromIP(destination));

            DsrOptionSRHeader sourceRoute;
            std::vector<Ipv4Address> nodeList =
                toDst.GetVector(); // Get the route from the route entry we found
            Ipv4Address nextHop =
                SearchNextHop(m_mainAddress, nodeList); // Get the next hop address for the route
            if (nextHop == "0.0.0.0")
            {
                PacketNewRoute(cleanP, source, destination, protocol);
                return;
            }
            uint8_t salvage = 0;
            sourceRoute.SetNodesAddress(
                nodeList); // Save the whole route in the source route header of the packet
            /// When found a route and use it, UseExtends to the link cache
            if (m_routeCache->IsLinkCache())
            {
                m_routeCache->UseExtends(nodeList);
            }
            // The segmentsLeft field will indicate the hops to go
            sourceRoute.SetSegmentsLeft(nodeList.size() - 2);
            sourceRoute.SetSalvage(salvage);

            uint8_t length = sourceRoute.GetLength();

            dsrRoutingHeader.SetPayloadLength(uint16_t(length) + 2);
            dsrRoutingHeader.AddDsrOption(sourceRoute);
            cleanP->AddHeader(dsrRoutingHeader);

            Ptr<const Packet> mtP = cleanP->Copy();
            NS_LOG_DEBUG("maintain packet size " << cleanP->GetSize());
            // Put the data packet in the maintenance queue for data packet retransmission
            DsrMaintainBuffEntry newEntry(/*packet=*/mtP,
                                          /*ourAddress=*/m_mainAddress,
                                          /*nextHop=*/nextHop,
                                          /*src=*/source,
                                          /*dst=*/destination,
                                          /*ackId=*/0,
                                          /*segsLeft=*/nodeList.size() - 2,
                                          /*expire=*/m_maxMaintainTime);
            bool result =
                m_maintainBuffer.Enqueue(newEntry); // Enqueue the packet the the maintenance buffer
            if (result)
            {
                NetworkKey networkKey;
                networkKey.m_ackId = newEntry.GetAckId();
                networkKey.m_ourAdd = newEntry.GetOurAdd();
                networkKey.m_nextHop = newEntry.GetNextHop();
                networkKey.m_source = newEntry.GetSrc();
                networkKey.m_destination = newEntry.GetDst();

                PassiveKey passiveKey;
                passiveKey.m_ackId = 0;
                passiveKey.m_source = newEntry.GetSrc();
                passiveKey.m_destination = newEntry.GetDst();
                passiveKey.m_segsLeft = newEntry.GetSegsLeft();

                LinkKey linkKey;
                linkKey.m_source = newEntry.GetSrc();
                linkKey.m_destination = newEntry.GetDst();
                linkKey.m_ourAdd = newEntry.GetOurAdd();
                linkKey.m_nextHop = newEntry.GetNextHop();

                m_addressForwardCnt[networkKey] = 0;
                m_passiveCnt[passiveKey] = 0;
                m_linkCnt[linkKey] = 0;

                if (m_linkAck)
                {
                    ScheduleLinkPacketRetry(newEntry, protocol);
                }
                else
                {
                    NS_LOG_LOGIC("Not using link acknowledgment");
                    if (nextHop != destination)
                    {
                        SchedulePassivePacketRetry(newEntry, protocol);
                    }
                    else
                    {
                        // This is the first network retry
                        ScheduleNetworkPacketRetry(newEntry, true, protocol);
                    }
                }
            }

            if (m_sendBuffer.GetSize() != 0 && m_sendBuffer.Find(destination))
            {
                // Try to send packet from *previously* queued entries from send buffer if any
                Simulator::Schedule(MilliSeconds(m_uniformRandomVariable->GetInteger(0, 100)),
                                    &DsrRouting::SendPacketFromBuffer,
                                    this,
                                    sourceRoute,
                                    nextHop,
                                    protocol);
            }
        }
    }
}

uint16_t
DsrRouting::AddAckReqHeader(Ptr<Packet>& packet, Ipv4Address nextHop)
{
    NS_LOG_FUNCTION(this << packet << nextHop);
    // This packet is used to peek option type
    Ptr<Packet> dsrP = packet->Copy();
    Ptr<Packet> tmpP = packet->Copy();

    DsrRoutingHeader dsrRoutingHeader;
    dsrP->RemoveHeader(dsrRoutingHeader); // Remove the DSR header in whole
    uint8_t protocol = dsrRoutingHeader.GetNextHeader();
    uint32_t sourceId = dsrRoutingHeader.GetSourceId();
    uint32_t destinationId = dsrRoutingHeader.GetDestId();
    uint32_t offset = dsrRoutingHeader.GetDsrOptionsOffset();
    tmpP->RemoveAtStart(
        offset); // Here the processed size is 8 bytes, which is the fixed sized extension header

    // Get the number of routers' address field
    uint8_t buf[2];
    tmpP->CopyData(buf, sizeof(buf));
    uint8_t numberAddress = (buf[1] - 2) / 4;
    DsrOptionSRHeader sourceRoute;
    sourceRoute.SetNumberAddress(numberAddress);
    tmpP->RemoveHeader(sourceRoute); // this is a clean packet without any dsr involved headers

    DsrOptionAckReqHeader ackReq;
    m_ackId = m_routeCache->CheckUniqueAckId(nextHop);
    ackReq.SetAckId(m_ackId);
    uint8_t length = (sourceRoute.GetLength() + ackReq.GetLength());
    DsrRoutingHeader newDsrRoutingHeader;
    newDsrRoutingHeader.SetNextHeader(protocol);
    newDsrRoutingHeader.SetMessageType(2);
    newDsrRoutingHeader.SetSourceId(sourceId);
    newDsrRoutingHeader.SetDestId(destinationId);
    newDsrRoutingHeader.SetPayloadLength(length + 4);
    newDsrRoutingHeader.AddDsrOption(sourceRoute);
    newDsrRoutingHeader.AddDsrOption(ackReq);
    dsrP->AddHeader(newDsrRoutingHeader);
    // give the dsrP value to packet and then return
    packet = dsrP;
    return m_ackId;
}

void
DsrRouting::SendPacket(Ptr<Packet> packet,
                       Ipv4Address source,
                       Ipv4Address nextHop,
                       uint8_t protocol)
{
    NS_LOG_FUNCTION(this << packet << source << nextHop << (uint32_t)protocol);
    // Send out the data packet
    m_ipv4Route = SetRoute(nextHop, m_mainAddress);
    Ptr<NetDevice> dev = m_ip->GetNetDevice(m_ip->GetInterfaceForAddress(m_mainAddress));
    m_ipv4Route->SetOutputDevice(dev);

    uint32_t priority = GetPriority(DSR_DATA_PACKET);
    auto i = m_priorityQueue.find(priority);
    Ptr<dsr::DsrNetworkQueue> dsrNetworkQueue = i->second;
    NS_LOG_INFO("Will be inserting into priority queue number: " << priority);

    // m_downTarget (packet, source, nextHop, GetProtocolNumber (), m_ipv4Route);

    /// \todo New DsrNetworkQueueEntry
    DsrNetworkQueueEntry newEntry(packet, source, nextHop, Simulator::Now(), m_ipv4Route);

    if (dsrNetworkQueue->Enqueue(newEntry))
    {
        Scheduler(priority);
    }
    else
    {
        NS_LOG_INFO("Packet dropped as dsr network queue is full");
    }
}

void
DsrRouting::Scheduler(uint32_t priority)
{
    NS_LOG_FUNCTION(this);
    PriorityScheduler(priority, true);
}

void
DsrRouting::PriorityScheduler(uint32_t priority, bool continueWithFirst)
{
    NS_LOG_FUNCTION(this << priority << continueWithFirst);
    uint32_t numPriorities;
    if (continueWithFirst)
    {
        numPriorities = 0;
    }
    else
    {
        numPriorities = priority;
    }
    // priorities ranging from 0 to m_numPriorityQueues, with 0 as the highest priority
    for (uint32_t i = priority; numPriorities < m_numPriorityQueues; numPriorities++)
    {
        auto q = m_priorityQueue.find(i);
        Ptr<dsr::DsrNetworkQueue> dsrNetworkQueue = q->second;
        uint32_t queueSize = dsrNetworkQueue->GetSize();
        if (queueSize == 0)
        {
            if ((i == (m_numPriorityQueues - 1)) && continueWithFirst)
            {
                i = 0;
            }
            else
            {
                i++;
            }
        }
        else
        {
            uint32_t totalQueueSize = 0;
            for (auto j = m_priorityQueue.begin(); j != m_priorityQueue.end(); j++)
            {
                NS_LOG_INFO("The size of the network queue for " << j->first << " is "
                                                                 << j->second->GetSize());
                totalQueueSize += j->second->GetSize();
                NS_LOG_INFO("The total network queue size is " << totalQueueSize);
            }
            if (totalQueueSize > 5)
            {
                // Here the queue size is larger than 5, we need to increase the retransmission
                // timer for each packet in the network queue
                IncreaseRetransTimer();
            }
            DsrNetworkQueueEntry newEntry;
            dsrNetworkQueue->Dequeue(newEntry);
            if (SendRealDown(newEntry))
            {
                NS_LOG_LOGIC("Packet sent by Dsr. Calling PriorityScheduler after some time");
                // packet was successfully sent down. call scheduler after some time
                Simulator::Schedule(MicroSeconds(m_uniformRandomVariable->GetInteger(0, 1000)),
                                    &DsrRouting::PriorityScheduler,
                                    this,
                                    i,
                                    false);
            }
            else
            {
                // packet was dropped by Dsr. Call scheduler immediately so that we can
                // send another packet immediately.
                NS_LOG_LOGIC("Packet dropped by Dsr. Calling PriorityScheduler immediately");
                Simulator::Schedule(Seconds(0), &DsrRouting::PriorityScheduler, this, i, false);
            }

            if ((i == (m_numPriorityQueues - 1)) && continueWithFirst)
            {
                i = 0;
            }
            else
            {
                i++;
            }
        }
    }
}

void
DsrRouting::IncreaseRetransTimer()
{
    NS_LOG_FUNCTION(this);
    // We may want to get the queue first and then we need to save a vector of the entries here and
    // then find
    uint32_t priority = GetPriority(DSR_DATA_PACKET);
    auto i = m_priorityQueue.find(priority);
    Ptr<dsr::DsrNetworkQueue> dsrNetworkQueue = i->second;

    std::vector<DsrNetworkQueueEntry> newNetworkQueue = dsrNetworkQueue->GetQueue();
    for (auto i = newNetworkQueue.begin(); i != newNetworkQueue.end(); i++)
    {
        Ipv4Address nextHop = i->GetNextHopAddress();
        for (auto j = m_addressForwardTimer.begin(); j != m_addressForwardTimer.end(); j++)
        {
            if (nextHop == j->first.m_nextHop)
            {
                NS_LOG_DEBUG("The network delay left is " << j->second.GetDelayLeft());
                j->second.SetDelay(j->second.GetDelayLeft() + m_retransIncr);
            }
        }
    }
}

bool
DsrRouting::SendRealDown(DsrNetworkQueueEntry& newEntry)
{
    NS_LOG_FUNCTION(this);
    Ipv4Address source = newEntry.GetSourceAddress();
    Ipv4Address nextHop = newEntry.GetNextHopAddress();
    Ptr<Packet> packet = newEntry.GetPacket()->Copy();
    Ptr<Ipv4Route> route = newEntry.GetIpv4Route();
    m_downTarget(packet, source, nextHop, GetProtocolNumber(), route);
    return true;
}

void
DsrRouting::SendPacketFromBuffer(const DsrOptionSRHeader& sourceRoute,
                                 Ipv4Address nextHop,
                                 uint8_t protocol)
{
    NS_LOG_FUNCTION(this << nextHop << (uint32_t)protocol);
    NS_ASSERT_MSG(!m_downTarget.IsNull(), "Error, DsrRouting cannot send downward");

    // Reconstruct the route and Retransmit the data packet
    std::vector<Ipv4Address> nodeList = sourceRoute.GetNodesAddress();
    Ipv4Address destination = nodeList.back();
    Ipv4Address source = nodeList.front(); // Get the source address
    NS_LOG_INFO("The nexthop address " << nextHop << " the source " << source << " the destination "
                                       << destination);
    /*
     * Here we try to find data packet from send buffer, if packet with this destination found, send
     * it out
     */
    if (m_sendBuffer.Find(destination))
    {
        NS_LOG_DEBUG("destination over here " << destination);

        /// When found a route and use it, UseExtends to the link cache
        if (m_routeCache->IsLinkCache())
        {
            m_routeCache->UseExtends(nodeList);
        }
        DsrSendBuffEntry entry;
        if (m_sendBuffer.Dequeue(destination, entry))
        {
            Ptr<Packet> packet = entry.GetPacket()->Copy();
            Ptr<Packet> p = packet->Copy(); // get a copy of the packet
            // Set the source route option
            DsrRoutingHeader dsrRoutingHeader;
            dsrRoutingHeader.SetNextHeader(protocol);
            dsrRoutingHeader.SetMessageType(2);
            dsrRoutingHeader.SetSourceId(GetIDfromIP(source));
            dsrRoutingHeader.SetDestId(GetIDfromIP(destination));

            uint8_t length = sourceRoute.GetLength();
            dsrRoutingHeader.SetPayloadLength(uint16_t(length) + 2);
            dsrRoutingHeader.AddDsrOption(sourceRoute);

            p->AddHeader(dsrRoutingHeader);

            Ptr<const Packet> mtP = p->Copy();
            // Put the data packet in the maintenance queue for data packet retransmission
            DsrMaintainBuffEntry newEntry(/*packet=*/mtP,
                                          /*ourAddress=*/m_mainAddress,
                                          /*nextHop=*/nextHop,
                                          /*src=*/source,
                                          /*dst=*/destination,
                                          /*ackId=*/0,
                                          /*segsLeft=*/nodeList.size() - 2,
                                          /*expire=*/m_maxMaintainTime);
            bool result =
                m_maintainBuffer.Enqueue(newEntry); // Enqueue the packet the the maintenance buffer

            if (result)
            {
                NetworkKey networkKey;
                networkKey.m_ackId = newEntry.GetAckId();
                networkKey.m_ourAdd = newEntry.GetOurAdd();
                networkKey.m_nextHop = newEntry.GetNextHop();
                networkKey.m_source = newEntry.GetSrc();
                networkKey.m_destination = newEntry.GetDst();

                PassiveKey passiveKey;
                passiveKey.m_ackId = 0;
                passiveKey.m_source = newEntry.GetSrc();
                passiveKey.m_destination = newEntry.GetDst();
                passiveKey.m_segsLeft = newEntry.GetSegsLeft();

                LinkKey linkKey;
                linkKey.m_source = newEntry.GetSrc();
                linkKey.m_destination = newEntry.GetDst();
                linkKey.m_ourAdd = newEntry.GetOurAdd();
                linkKey.m_nextHop = newEntry.GetNextHop();

                m_addressForwardCnt[networkKey] = 0;
                m_passiveCnt[passiveKey] = 0;
                m_linkCnt[linkKey] = 0;

                if (m_linkAck)
                {
                    ScheduleLinkPacketRetry(newEntry, protocol);
                }
                else
                {
                    NS_LOG_LOGIC("Not using link acknowledgment");
                    if (nextHop != destination)
                    {
                        SchedulePassivePacketRetry(newEntry, protocol);
                    }
                    else
                    {
                        // This is the first network retry
                        ScheduleNetworkPacketRetry(newEntry, true, protocol);
                    }
                }
            }

            NS_LOG_DEBUG("send buffer size here and the destination " << m_sendBuffer.GetSize()
                                                                      << " " << destination);
            if (m_sendBuffer.GetSize() != 0 && m_sendBuffer.Find(destination))
            {
                NS_LOG_LOGIC("Schedule sending the next packet in send buffer");
                Simulator::Schedule(MilliSeconds(m_uniformRandomVariable->GetInteger(0, 100)),
                                    &DsrRouting::SendPacketFromBuffer,
                                    this,
                                    sourceRoute,
                                    nextHop,
                                    protocol);
            }
        }
        else
        {
            NS_LOG_LOGIC("All queued packets are out-dated for the destination in send buffer");
        }
    }
    /*
     * Here we try to find data packet from send buffer, if packet with this destination found, send
     * it out
     */
    else if (m_errorBuffer.Find(destination))
    {
        DsrErrorBuffEntry entry;
        if (m_errorBuffer.Dequeue(destination, entry))
        {
            Ptr<Packet> packet = entry.GetPacket()->Copy();
            NS_LOG_DEBUG("The queued packet size " << packet->GetSize());

            DsrRoutingHeader dsrRoutingHeader;
            Ptr<Packet> copyP = packet->Copy();
            Ptr<Packet> dsrPacket = packet->Copy();
            dsrPacket->RemoveHeader(dsrRoutingHeader);
            uint32_t offset = dsrRoutingHeader.GetDsrOptionsOffset();
            copyP->RemoveAtStart(offset); // Here the processed size is 8 bytes, which is the fixed
                                          // sized extension header
            /*
             * Peek data to get the option type as well as length and segmentsLeft field
             */
            uint32_t size = copyP->GetSize();
            auto data = new uint8_t[size];
            copyP->CopyData(data, size);

            uint8_t optionType = 0;
            optionType = *(data);
            NS_LOG_DEBUG("The option type value in send packet " << (uint32_t)optionType);
            if (optionType == 3)
            {
                NS_LOG_DEBUG("The packet is error packet");
                Ptr<dsr::DsrOptions> dsrOption;
                DsrOptionHeader dsrOptionHeader;

                uint8_t errorType = *(data + 2);
                NS_LOG_DEBUG("The error type");
                if (errorType == 1)
                {
                    NS_LOG_DEBUG("The packet is route error unreach packet");
                    DsrOptionRerrUnreachHeader rerr;
                    copyP->RemoveHeader(rerr);
                    NS_ASSERT(copyP->GetSize() == 0);
                    uint8_t length = (sourceRoute.GetLength() + rerr.GetLength());

                    DsrOptionRerrUnreachHeader newUnreach;
                    newUnreach.SetErrorType(1);
                    newUnreach.SetErrorSrc(rerr.GetErrorSrc());
                    newUnreach.SetUnreachNode(rerr.GetUnreachNode());
                    newUnreach.SetErrorDst(rerr.GetErrorDst());
                    newUnreach.SetOriginalDst(rerr.GetOriginalDst());
                    newUnreach.SetSalvage(rerr.GetSalvage()); // Set the value about whether to
                                                              // salvage a packet or not

                    std::vector<Ipv4Address> nodeList = sourceRoute.GetNodesAddress();
                    DsrRoutingHeader newRoutingHeader;
                    newRoutingHeader.SetNextHeader(protocol);
                    newRoutingHeader.SetMessageType(1);
                    newRoutingHeader.SetSourceId(GetIDfromIP(rerr.GetErrorSrc()));
                    newRoutingHeader.SetDestId(GetIDfromIP(rerr.GetErrorDst()));
                    newRoutingHeader.SetPayloadLength(uint16_t(length) + 4);
                    newRoutingHeader.AddDsrOption(newUnreach);
                    newRoutingHeader.AddDsrOption(sourceRoute);
                    /// When found a route and use it, UseExtends to the link cache
                    if (m_routeCache->IsLinkCache())
                    {
                        m_routeCache->UseExtends(nodeList);
                    }
                    SetRoute(nextHop, m_mainAddress);
                    Ptr<Packet> newPacket = Create<Packet>();
                    newPacket->AddHeader(newRoutingHeader); // Add the extension header with rerr
                                                            // and sourceRoute attached to it
                    Ptr<NetDevice> dev =
                        m_ip->GetNetDevice(m_ip->GetInterfaceForAddress(m_mainAddress));
                    m_ipv4Route->SetOutputDevice(dev);

                    uint32_t priority = GetPriority(DSR_CONTROL_PACKET);
                    auto i = m_priorityQueue.find(priority);
                    Ptr<dsr::DsrNetworkQueue> dsrNetworkQueue = i->second;
                    NS_LOG_DEBUG("Will be inserting into priority queue "
                                 << dsrNetworkQueue << " number: " << priority);

                    // m_downTarget (newPacket, m_mainAddress, nextHop, GetProtocolNumber (),
                    // m_ipv4Route);

                    /// \todo New DsrNetworkQueueEntry
                    DsrNetworkQueueEntry newEntry(newPacket,
                                                  m_mainAddress,
                                                  nextHop,
                                                  Simulator::Now(),
                                                  m_ipv4Route);

                    if (dsrNetworkQueue->Enqueue(newEntry))
                    {
                        Scheduler(priority);
                    }
                    else
                    {
                        NS_LOG_INFO("Packet dropped as dsr network queue is full");
                    }
                }
            }

            if (m_errorBuffer.GetSize() != 0 && m_errorBuffer.Find(destination))
            {
                NS_LOG_LOGIC("Schedule sending the next packet in error buffer");
                Simulator::Schedule(MilliSeconds(m_uniformRandomVariable->GetInteger(0, 100)),
                                    &DsrRouting::SendPacketFromBuffer,
                                    this,
                                    sourceRoute,
                                    nextHop,
                                    protocol);
            }
        }
    }
    else
    {
        NS_LOG_DEBUG("Packet not found in either the send or error buffer");
    }
}

bool
DsrRouting::PassiveEntryCheck(Ptr<Packet> packet,
                              Ipv4Address source,
                              Ipv4Address destination,
                              uint8_t segsLeft,
                              uint16_t fragmentOffset,
                              uint16_t identification,
                              bool saveEntry)
{
    NS_LOG_FUNCTION(this << packet << source << destination << (uint32_t)segsLeft);

    Ptr<Packet> p = packet->Copy();
    // Here the segments left value need to plus one to check the earlier hop maintain buffer entry
    DsrPassiveBuffEntry newEntry;
    newEntry.SetPacket(p);
    newEntry.SetSource(source);
    newEntry.SetDestination(destination);
    newEntry.SetIdentification(identification);
    newEntry.SetFragmentOffset(fragmentOffset);
    newEntry.SetSegsLeft(segsLeft); // We try to make sure the segments left is larger for 1

    NS_LOG_DEBUG("The passive buffer size " << m_passiveBuffer->GetSize());

    if (m_passiveBuffer->AllEqual(newEntry) && (!saveEntry))
    {
        // The PromiscEqual function will remove the maintain buffer entry if equal value found
        // It only compares the source and destination address, ackId, and the segments left value
        NS_LOG_DEBUG("We get the all equal for passive buffer here");

        DsrMaintainBuffEntry mbEntry;
        mbEntry.SetPacket(p);
        mbEntry.SetSrc(source);
        mbEntry.SetDst(destination);
        mbEntry.SetAckId(0);
        mbEntry.SetSegsLeft(segsLeft + 1);

        CancelPassivePacketTimer(mbEntry);
        return true;
    }
    if (saveEntry)
    {
        /// Save this passive buffer entry for later check
        m_passiveBuffer->Enqueue(newEntry);
    }
    return false;
}

bool
DsrRouting::CancelPassiveTimer(Ptr<Packet> packet,
                               Ipv4Address source,
                               Ipv4Address destination,
                               uint8_t segsLeft)
{
    NS_LOG_FUNCTION(this << packet << source << destination << (uint32_t)segsLeft);

    NS_LOG_DEBUG("Cancel the passive timer");

    Ptr<Packet> p = packet->Copy();
    // Here the segments left value need to plus one to check the earlier hop maintain buffer entry
    DsrMaintainBuffEntry newEntry;
    newEntry.SetPacket(p);
    newEntry.SetSrc(source);
    newEntry.SetDst(destination);
    newEntry.SetAckId(0);
    newEntry.SetSegsLeft(segsLeft + 1);

    if (m_maintainBuffer.PromiscEqual(newEntry))
    {
        // The PromiscEqual function will remove the maintain buffer entry if equal value found
        // It only compares the source and destination address, ackId, and the segments left value
        CancelPassivePacketTimer(newEntry);
        return true;
    }
    return false;
}

void
DsrRouting::CallCancelPacketTimer(uint16_t ackId,
                                  const Ipv4Header& ipv4Header,
                                  Ipv4Address realSrc,
                                  Ipv4Address realDst)
{
    NS_LOG_FUNCTION(this << (uint32_t)ackId << ipv4Header << realSrc << realDst);
    Ipv4Address sender = ipv4Header.GetDestination();
    Ipv4Address receiver = ipv4Header.GetSource();
    /*
     * Create a packet to fill maintenance buffer, not used to compare with maintenance entry
     * The reason is ack header doesn't have the original packet copy
     */
    Ptr<Packet> mainP = Create<Packet>();
    DsrMaintainBuffEntry newEntry(/*packet=*/mainP,
                                  /*ourAddress=*/sender,
                                  /*nextHop=*/receiver,
                                  /*src=*/realSrc,
                                  /*dst=*/realDst,
                                  /*ackId=*/ackId,
                                  /*segsLeft=*/0,
                                  /*expire=*/Simulator::Now());
    CancelNetworkPacketTimer(newEntry); // Only need to cancel network packet timer
}

void
DsrRouting::CancelPacketAllTimer(DsrMaintainBuffEntry& mb)
{
    NS_LOG_FUNCTION(this);
    CancelLinkPacketTimer(mb);
    CancelNetworkPacketTimer(mb);
    CancelPassivePacketTimer(mb);
}

void
DsrRouting::CancelLinkPacketTimer(DsrMaintainBuffEntry& mb)
{
    NS_LOG_FUNCTION(this);
    LinkKey linkKey;
    linkKey.m_ourAdd = mb.GetOurAdd();
    linkKey.m_nextHop = mb.GetNextHop();
    linkKey.m_source = mb.GetSrc();
    linkKey.m_destination = mb.GetDst();
    /*
     * Here we have found the entry for send retries, so we get the value and increase it by one
     */
    /// TODO need to think about this part
    m_linkCnt[linkKey] = 0;
    m_linkCnt.erase(linkKey);

    // TODO if find the linkkey, we need to remove it

    // Find the network acknowledgment timer
    auto i = m_linkAckTimer.find(linkKey);
    if (i == m_linkAckTimer.end())
    {
        NS_LOG_INFO("did not find the link timer");
    }
    else
    {
        NS_LOG_INFO("did find the link timer");
        /*
         * Schedule the packet retry
         * Push back the nextHop, source, destination address
         */
        m_linkAckTimer[linkKey].Cancel();
        if (m_linkAckTimer[linkKey].IsRunning())
        {
            NS_LOG_INFO("Timer not canceled");
        }
        m_linkAckTimer.erase(linkKey);
    }

    // Erase the maintenance entry
    // yet this does not check the segments left value here
    NS_LOG_DEBUG("The link buffer size " << m_maintainBuffer.GetSize());
    if (m_maintainBuffer.LinkEqual(mb))
    {
        NS_LOG_INFO("Link acknowledgment received, remove same maintenance buffer entry");
    }
}

void
DsrRouting::CancelNetworkPacketTimer(DsrMaintainBuffEntry& mb)
{
    NS_LOG_FUNCTION(this);
    NetworkKey networkKey;
    networkKey.m_ackId = mb.GetAckId();
    networkKey.m_ourAdd = mb.GetOurAdd();
    networkKey.m_nextHop = mb.GetNextHop();
    networkKey.m_source = mb.GetSrc();
    networkKey.m_destination = mb.GetDst();
    /*
     * Here we have found the entry for send retries, so we get the value and increase it by one
     */
    m_addressForwardCnt[networkKey] = 0;
    m_addressForwardCnt.erase(networkKey);

    NS_LOG_INFO("ackId " << mb.GetAckId() << " ourAdd " << mb.GetOurAdd() << " nextHop "
                         << mb.GetNextHop() << " source " << mb.GetSrc() << " destination "
                         << mb.GetDst() << " segsLeft " << (uint32_t)mb.GetSegsLeft());
    // Find the network acknowledgment timer
    auto i = m_addressForwardTimer.find(networkKey);
    if (i == m_addressForwardTimer.end())
    {
        NS_LOG_INFO("did not find the packet timer");
    }
    else
    {
        NS_LOG_INFO("did find the packet timer");
        /*
         * Schedule the packet retry
         * Push back the nextHop, source, destination address
         */
        m_addressForwardTimer[networkKey].Cancel();
        if (m_addressForwardTimer[networkKey].IsRunning())
        {
            NS_LOG_INFO("Timer not canceled");
        }
        m_addressForwardTimer.erase(networkKey);
    }
    // Erase the maintenance entry
    // yet this does not check the segments left value here
    if (m_maintainBuffer.NetworkEqual(mb))
    {
        NS_LOG_INFO("Remove same maintenance buffer entry based on network acknowledgment");
    }
}

void
DsrRouting::CancelPassivePacketTimer(DsrMaintainBuffEntry& mb)
{
    NS_LOG_FUNCTION(this);
    PassiveKey passiveKey;
    passiveKey.m_ackId = 0;
    passiveKey.m_source = mb.GetSrc();
    passiveKey.m_destination = mb.GetDst();
    passiveKey.m_segsLeft = mb.GetSegsLeft();

    m_passiveCnt[passiveKey] = 0;
    m_passiveCnt.erase(passiveKey);

    // Find the passive acknowledgment timer
    auto j = m_passiveAckTimer.find(passiveKey);
    if (j == m_passiveAckTimer.end())
    {
        NS_LOG_INFO("did not find the passive timer");
    }
    else
    {
        NS_LOG_INFO("find the passive timer");
        /*
         * Cancel passive acknowledgment timer
         */
        m_passiveAckTimer[passiveKey].Cancel();
        if (m_passiveAckTimer[passiveKey].IsRunning())
        {
            NS_LOG_INFO("Timer not canceled");
        }
        m_passiveAckTimer.erase(passiveKey);
    }
}

void
DsrRouting::CancelPacketTimerNextHop(Ipv4Address nextHop, uint8_t protocol)
{
    NS_LOG_FUNCTION(this << nextHop << (uint32_t)protocol);

    DsrMaintainBuffEntry entry;
    std::vector<Ipv4Address> previousErrorDst;
    if (m_maintainBuffer.Dequeue(nextHop, entry))
    {
        Ipv4Address source = entry.GetSrc();
        Ipv4Address destination = entry.GetDst();

        Ptr<Packet> dsrP = entry.GetPacket()->Copy();
        Ptr<Packet> p = dsrP->Copy();
        Ptr<Packet> packet = dsrP->Copy();
        DsrRoutingHeader dsrRoutingHeader;
        dsrP->RemoveHeader(dsrRoutingHeader); // Remove the dsr header in whole
        uint32_t offset = dsrRoutingHeader.GetDsrOptionsOffset();
        p->RemoveAtStart(offset);

        // Get the number of routers' address field
        uint8_t buf[2];
        p->CopyData(buf, sizeof(buf));
        uint8_t numberAddress = (buf[1] - 2) / 4;
        NS_LOG_DEBUG("The number of addresses " << (uint32_t)numberAddress);
        DsrOptionSRHeader sourceRoute;
        sourceRoute.SetNumberAddress(numberAddress);
        p->RemoveHeader(sourceRoute);
        std::vector<Ipv4Address> nodeList = sourceRoute.GetNodesAddress();
        uint8_t salvage = sourceRoute.GetSalvage();
        Ipv4Address address1 = nodeList[1];
        PrintVector(nodeList);

        /*
         * If the salvage is not 0, use the first address in the route as the error dst in error
         * header otherwise use the source of packet as the error destination
         */
        Ipv4Address errorDst;
        if (salvage)
        {
            errorDst = address1;
        }
        else
        {
            errorDst = source;
        }
        /// TODO if the errorDst is not seen before
        if (std::find(previousErrorDst.begin(), previousErrorDst.end(), destination) ==
            previousErrorDst.end())
        {
            NS_LOG_DEBUG("have not seen this dst before " << errorDst << " in "
                                                          << previousErrorDst.size());
            SendUnreachError(nextHop, errorDst, destination, salvage, protocol);
            previousErrorDst.push_back(errorDst);
        }

        /*
         * Cancel the packet timer and then salvage the data packet
         */

        CancelPacketAllTimer(entry);
        SalvagePacket(packet, source, destination, protocol);

        if (m_maintainBuffer.GetSize() && m_maintainBuffer.Find(nextHop))
        {
            NS_LOG_INFO("Cancel the packet timer for next maintenance entry");
            Simulator::Schedule(MilliSeconds(m_uniformRandomVariable->GetInteger(0, 100)),
                                &DsrRouting::CancelPacketTimerNextHop,
                                this,
                                nextHop,
                                protocol);
        }
    }
    else
    {
        NS_LOG_INFO("Maintenance buffer entry not found");
    }
    /// TODO need to think about whether we need the network queue entry or not
}

void
DsrRouting::SalvagePacket(Ptr<const Packet> packet,
                          Ipv4Address source,
                          Ipv4Address dst,
                          uint8_t protocol)
{
    NS_LOG_FUNCTION(this << packet << source << dst << (uint32_t)protocol);
    // Create two copies of packet
    Ptr<Packet> p = packet->Copy();
    Ptr<Packet> newPacket = packet->Copy();
    // Remove the routing header in a whole to get a clean packet
    DsrRoutingHeader dsrRoutingHeader;
    p->RemoveHeader(dsrRoutingHeader);
    // Remove offset of dsr routing header
    uint8_t offset = dsrRoutingHeader.GetDsrOptionsOffset();
    newPacket->RemoveAtStart(offset);

    // Get the number of routers' address field
    uint8_t buf[2];
    newPacket->CopyData(buf, sizeof(buf));
    uint8_t numberAddress = (buf[1] - 2) / 4;

    DsrOptionSRHeader sourceRoute;
    sourceRoute.SetNumberAddress(numberAddress);
    newPacket->RemoveHeader(sourceRoute);
    uint8_t salvage = sourceRoute.GetSalvage();
    /*
     * Look in the route cache for other routes for this destination
     */
    DsrRouteCacheEntry toDst;
    bool findRoute = m_routeCache->LookupRoute(dst, toDst);
    if (findRoute && (salvage < m_maxSalvageCount))
    {
        NS_LOG_DEBUG("We have found a route for the packet");
        DsrRoutingHeader newDsrRoutingHeader;
        newDsrRoutingHeader.SetNextHeader(protocol);
        newDsrRoutingHeader.SetMessageType(2);
        newDsrRoutingHeader.SetSourceId(GetIDfromIP(source));
        newDsrRoutingHeader.SetDestId(GetIDfromIP(dst));

        std::vector<Ipv4Address> nodeList =
            toDst.GetVector(); // Get the route from the route entry we found
        Ipv4Address nextHop =
            SearchNextHop(m_mainAddress, nodeList); // Get the next hop address for the route
        if (nextHop == "0.0.0.0")
        {
            PacketNewRoute(p, source, dst, protocol);
            return;
        }
        // Increase the salvage count by 1
        salvage++;
        DsrOptionSRHeader sourceRoute;
        sourceRoute.SetSalvage(salvage);
        // Save the whole route in the source route header of the packet
        sourceRoute.SetNodesAddress(nodeList);
        // The segmentsLeft field will indicate the hops to go
        sourceRoute.SetSegmentsLeft(nodeList.size() - 2);
        /// When found a route and use it, UseExtends to the link cache
        if (m_routeCache->IsLinkCache())
        {
            m_routeCache->UseExtends(nodeList);
        }
        uint8_t length = sourceRoute.GetLength();
        NS_LOG_INFO("length of source route header " << (uint32_t)(sourceRoute.GetLength()));
        newDsrRoutingHeader.SetPayloadLength(uint16_t(length) + 2);
        newDsrRoutingHeader.AddDsrOption(sourceRoute);
        p->AddHeader(newDsrRoutingHeader);

        SetRoute(nextHop, m_mainAddress);
        Ptr<NetDevice> dev = m_ip->GetNetDevice(m_ip->GetInterfaceForAddress(m_mainAddress));
        m_ipv4Route->SetOutputDevice(dev);

        // Send out the data packet
        uint32_t priority = GetPriority(DSR_DATA_PACKET);
        auto i = m_priorityQueue.find(priority);
        Ptr<dsr::DsrNetworkQueue> dsrNetworkQueue = i->second;
        NS_LOG_DEBUG("Will be inserting into priority queue " << dsrNetworkQueue
                                                              << " number: " << priority);

        // m_downTarget (p, m_mainAddress, nextHop, GetProtocolNumber (), m_ipv4Route);

        /// \todo New DsrNetworkQueueEntry
        DsrNetworkQueueEntry newEntry(p, m_mainAddress, nextHop, Simulator::Now(), m_ipv4Route);

        if (dsrNetworkQueue->Enqueue(newEntry))
        {
            Scheduler(priority);
        }
        else
        {
            NS_LOG_INFO("Packet dropped as dsr network queue is full");
        }

        /*
         * Mark the next hop address in blacklist
         */
        //      NS_LOG_DEBUG ("Save the next hop node in blacklist");
        //      m_rreqTable->MarkLinkAsUnidirectional (nextHop, m_blacklistTimeout);
    }
    else
    {
        NS_LOG_DEBUG("Will not salvage this packet, silently drop");
    }
}

void
DsrRouting::ScheduleLinkPacketRetry(DsrMaintainBuffEntry& mb, uint8_t protocol)
{
    NS_LOG_FUNCTION(this << (uint32_t)protocol);

    Ptr<Packet> p = mb.GetPacket()->Copy();
    Ipv4Address source = mb.GetSrc();
    Ipv4Address nextHop = mb.GetNextHop();

    // Send the data packet out before schedule the next packet transmission
    SendPacket(p, source, nextHop, protocol);

    LinkKey linkKey;
    linkKey.m_source = mb.GetSrc();
    linkKey.m_destination = mb.GetDst();
    linkKey.m_ourAdd = mb.GetOurAdd();
    linkKey.m_nextHop = mb.GetNextHop();

    if (m_linkAckTimer.find(linkKey) == m_linkAckTimer.end())
    {
        Timer timer(Timer::CANCEL_ON_DESTROY);
        m_linkAckTimer[linkKey] = timer;
    }
    m_linkAckTimer[linkKey].SetFunction(&DsrRouting::LinkScheduleTimerExpire, this);
    m_linkAckTimer[linkKey].Cancel();
    m_linkAckTimer[linkKey].SetArguments(mb, protocol);
    m_linkAckTimer[linkKey].Schedule(m_linkAckTimeout);
}

void
DsrRouting::SchedulePassivePacketRetry(DsrMaintainBuffEntry& mb, uint8_t protocol)
{
    NS_LOG_FUNCTION(this << (uint32_t)protocol);

    Ptr<Packet> p = mb.GetPacket()->Copy();
    Ipv4Address source = mb.GetSrc();
    Ipv4Address nextHop = mb.GetNextHop();

    // Send the data packet out before schedule the next packet transmission
    SendPacket(p, source, nextHop, protocol);

    PassiveKey passiveKey;
    passiveKey.m_ackId = 0;
    passiveKey.m_source = mb.GetSrc();
    passiveKey.m_destination = mb.GetDst();
    passiveKey.m_segsLeft = mb.GetSegsLeft();

    if (m_passiveAckTimer.find(passiveKey) == m_passiveAckTimer.end())
    {
        Timer timer(Timer::CANCEL_ON_DESTROY);
        m_passiveAckTimer[passiveKey] = timer;
    }
    NS_LOG_DEBUG("The passive acknowledgment option for data packet");
    m_passiveAckTimer[passiveKey].SetFunction(&DsrRouting::PassiveScheduleTimerExpire, this);
    m_passiveAckTimer[passiveKey].Cancel();
    m_passiveAckTimer[passiveKey].SetArguments(mb, protocol);
    m_passiveAckTimer[passiveKey].Schedule(m_passiveAckTimeout);
}

void
DsrRouting::ScheduleNetworkPacketRetry(DsrMaintainBuffEntry& mb, bool isFirst, uint8_t protocol)
{
    Ptr<Packet> p = Create<Packet>();
    Ptr<Packet> dsrP = Create<Packet>();
    // The new entry will be used for retransmission
    NetworkKey networkKey;
    Ipv4Address nextHop = mb.GetNextHop();
    NS_LOG_DEBUG("is the first retry or not " << isFirst);
    if (isFirst)
    {
        // This is the very first network packet retry
        p = mb.GetPacket()->Copy();
        // Here we add the ack request header to the data packet for network acknowledgement
        uint16_t ackId = AddAckReqHeader(p, nextHop);

        Ipv4Address source = mb.GetSrc();
        Ipv4Address nextHop = mb.GetNextHop();
        // Send the data packet out before schedule the next packet transmission
        SendPacket(p, source, nextHop, protocol);

        dsrP = p->Copy();
        DsrMaintainBuffEntry newEntry = mb;
        // The function AllEqual will find the exact entry and delete it if found
        m_maintainBuffer.AllEqual(mb);
        newEntry.SetPacket(dsrP);
        newEntry.SetAckId(ackId);
        newEntry.SetExpireTime(m_maxMaintainTime);

        networkKey.m_ackId = newEntry.GetAckId();
        networkKey.m_ourAdd = newEntry.GetOurAdd();
        networkKey.m_nextHop = newEntry.GetNextHop();
        networkKey.m_source = newEntry.GetSrc();
        networkKey.m_destination = newEntry.GetDst();

        m_addressForwardCnt[networkKey] = 0;
        if (!m_maintainBuffer.Enqueue(newEntry))
        {
            NS_LOG_ERROR("Failed to enqueue packet retry");
        }

        if (m_addressForwardTimer.find(networkKey) == m_addressForwardTimer.end())
        {
            Timer timer(Timer::CANCEL_ON_DESTROY);
            m_addressForwardTimer[networkKey] = timer;
        }

        // After m_tryPassiveAcks, schedule the packet retransmission using network acknowledgment
        // option
        m_addressForwardTimer[networkKey].SetFunction(&DsrRouting::NetworkScheduleTimerExpire,
                                                      this);
        m_addressForwardTimer[networkKey].Cancel();
        m_addressForwardTimer[networkKey].SetArguments(newEntry, protocol);
        NS_LOG_DEBUG("The packet retries time for " << newEntry.GetAckId() << " is "
                                                    << m_sendRetries << " and the delay time is "
                                                    << Time(2 * m_nodeTraversalTime).As(Time::S));
        // Back-off mechanism
        m_addressForwardTimer[networkKey].Schedule(Time(2 * m_nodeTraversalTime));
    }
    else
    {
        networkKey.m_ackId = mb.GetAckId();
        networkKey.m_ourAdd = mb.GetOurAdd();
        networkKey.m_nextHop = mb.GetNextHop();
        networkKey.m_source = mb.GetSrc();
        networkKey.m_destination = mb.GetDst();
        /*
         * Here we have found the entry for send retries, so we get the value and increase it by one
         */
        m_sendRetries = m_addressForwardCnt[networkKey];
        NS_LOG_DEBUG("The packet retry we have done " << m_sendRetries);

        p = mb.GetPacket()->Copy();
        dsrP = mb.GetPacket()->Copy();

        Ipv4Address source = mb.GetSrc();
        Ipv4Address nextHop = mb.GetNextHop();
        // Send the data packet out before schedule the next packet transmission
        SendPacket(p, source, nextHop, protocol);

        NS_LOG_DEBUG("The packet with dsr header " << dsrP->GetSize());
        networkKey.m_ackId = mb.GetAckId();
        networkKey.m_ourAdd = mb.GetOurAdd();
        networkKey.m_nextHop = mb.GetNextHop();
        networkKey.m_source = mb.GetSrc();
        networkKey.m_destination = mb.GetDst();
        /*
         *  If a data packet has been attempted SendRetries times at the maximum TTL without
         *  receiving any ACK, all data packets destined for the corresponding destination SHOULD be
         *  dropped from the send buffer
         *
         *  The maxMaintRexmt also needs to decrease one for the passive ack packet
         */
        /*
         * Check if the send retry time for a certain packet has already passed max maintenance
         * retransmission time or not
         */

        // After m_tryPassiveAcks, schedule the packet retransmission using network acknowledgment
        // option
        m_addressForwardTimer[networkKey].SetFunction(&DsrRouting::NetworkScheduleTimerExpire,
                                                      this);
        m_addressForwardTimer[networkKey].Cancel();
        m_addressForwardTimer[networkKey].SetArguments(mb, protocol);
        NS_LOG_DEBUG("The packet retries time for "
                     << mb.GetAckId() << " is " << m_sendRetries << " and the delay time is "
                     << Time(2 * m_sendRetries * m_nodeTraversalTime).As(Time::S));
        // Back-off mechanism
        m_addressForwardTimer[networkKey].Schedule(Time(2 * m_sendRetries * m_nodeTraversalTime));
    }
}

void
DsrRouting::LinkScheduleTimerExpire(DsrMaintainBuffEntry& mb, uint8_t protocol)
{
    NS_LOG_FUNCTION(this << (uint32_t)protocol);
    Ipv4Address nextHop = mb.GetNextHop();
    Ptr<const Packet> packet = mb.GetPacket();
    SetRoute(nextHop, m_mainAddress);
    Ptr<Packet> p = packet->Copy();

    LinkKey lk;
    lk.m_source = mb.GetSrc();
    lk.m_destination = mb.GetDst();
    lk.m_ourAdd = mb.GetOurAdd();
    lk.m_nextHop = mb.GetNextHop();

    // Cancel passive ack timer
    m_linkAckTimer[lk].Cancel();
    if (m_linkAckTimer[lk].IsRunning())
    {
        NS_LOG_DEBUG("Timer not canceled");
    }
    m_linkAckTimer.erase(lk);

    // Increase the send retry times
    m_linkRetries = m_linkCnt[lk];
    if (m_linkRetries < m_tryLinkAcks)
    {
        m_linkCnt[lk] = ++m_linkRetries;
        ScheduleLinkPacketRetry(mb, protocol);
    }
    else
    {
        NS_LOG_INFO("We need to send error messages now");

        // Delete all the routes including the links
        m_routeCache->DeleteAllRoutesIncludeLink(m_mainAddress, nextHop, m_mainAddress);
        /*
         * here we cancel the packet retransmission time for all the packets have next hop address
         * as nextHop Also salvage the packet for the all the packet destined for the nextHop
         * address this is also responsible for send unreachable error back to source
         */
        CancelPacketTimerNextHop(nextHop, protocol);
    }
}

void
DsrRouting::PassiveScheduleTimerExpire(DsrMaintainBuffEntry& mb, uint8_t protocol)
{
    NS_LOG_FUNCTION(this << (uint32_t)protocol);
    Ipv4Address nextHop = mb.GetNextHop();
    Ptr<const Packet> packet = mb.GetPacket();
    SetRoute(nextHop, m_mainAddress);
    Ptr<Packet> p = packet->Copy();

    PassiveKey pk;
    pk.m_ackId = 0;
    pk.m_source = mb.GetSrc();
    pk.m_destination = mb.GetDst();
    pk.m_segsLeft = mb.GetSegsLeft();

    // Cancel passive ack timer
    m_passiveAckTimer[pk].Cancel();
    if (m_passiveAckTimer[pk].IsRunning())
    {
        NS_LOG_DEBUG("Timer not canceled");
    }
    m_passiveAckTimer.erase(pk);

    // Increase the send retry times
    m_passiveRetries = m_passiveCnt[pk];
    if (m_passiveRetries < m_tryPassiveAcks)
    {
        m_passiveCnt[pk] = ++m_passiveRetries;
        SchedulePassivePacketRetry(mb, protocol);
    }
    else
    {
        // This is the first network acknowledgement retry
        // Cancel the passive packet timer now and remove maintenance buffer entry for it
        CancelPassivePacketTimer(mb);
        ScheduleNetworkPacketRetry(mb, true, protocol);
    }
}

int64_t
DsrRouting::AssignStreams(int64_t stream)
{
    NS_LOG_FUNCTION(this << stream);
    m_uniformRandomVariable->SetStream(stream);
    return 1;
}

void
DsrRouting::NetworkScheduleTimerExpire(DsrMaintainBuffEntry& mb, uint8_t protocol)
{
    Ptr<Packet> p = mb.GetPacket()->Copy();
    Ipv4Address source = mb.GetSrc();
    Ipv4Address nextHop = mb.GetNextHop();
    Ipv4Address dst = mb.GetDst();

    NetworkKey networkKey;
    networkKey.m_ackId = mb.GetAckId();
    networkKey.m_ourAdd = mb.GetOurAdd();
    networkKey.m_nextHop = nextHop;
    networkKey.m_source = source;
    networkKey.m_destination = dst;

    // Increase the send retry times
    m_sendRetries = m_addressForwardCnt[networkKey];

    if (m_sendRetries >= m_maxMaintRexmt)
    {
        // Delete all the routes including the links
        m_routeCache->DeleteAllRoutesIncludeLink(m_mainAddress, nextHop, m_mainAddress);
        /*
         * here we cancel the packet retransmission time for all the packets have next hop address
         * as nextHop Also salvage the packet for the all the packet destined for the nextHop
         * address
         */
        CancelPacketTimerNextHop(nextHop, protocol);
    }
    else
    {
        m_addressForwardCnt[networkKey] = ++m_sendRetries;
        ScheduleNetworkPacketRetry(mb, false, protocol);
    }
}

void
DsrRouting::ForwardPacket(Ptr<const Packet> packet,
                          DsrOptionSRHeader& sourceRoute,
                          const Ipv4Header& ipv4Header,
                          Ipv4Address source,
                          Ipv4Address nextHop,
                          Ipv4Address targetAddress,
                          uint8_t protocol,
                          Ptr<Ipv4Route> route)
{
    NS_LOG_FUNCTION(this << packet << sourceRoute << source << nextHop << targetAddress
                         << (uint32_t)protocol << route);
    NS_ASSERT_MSG(!m_downTarget.IsNull(), "Error, DsrRouting cannot send downward");

    DsrRoutingHeader dsrRoutingHeader;
    dsrRoutingHeader.SetNextHeader(protocol);
    dsrRoutingHeader.SetMessageType(2);
    dsrRoutingHeader.SetSourceId(GetIDfromIP(source));
    dsrRoutingHeader.SetDestId(GetIDfromIP(targetAddress));

    // We get the salvage value in sourceRoute header and set it to route error header if triggered
    // error
    Ptr<Packet> p = packet->Copy();
    uint8_t length = sourceRoute.GetLength();
    dsrRoutingHeader.SetPayloadLength(uint16_t(length) + 2);
    dsrRoutingHeader.AddDsrOption(sourceRoute);
    p->AddHeader(dsrRoutingHeader);

    Ptr<const Packet> mtP = p->Copy();

    DsrMaintainBuffEntry newEntry(/*packet=*/mtP,
                                  /*ourAddress=*/m_mainAddress,
                                  /*nextHop=*/nextHop,
                                  /*src=*/source,
                                  /*dst=*/targetAddress,
                                  /*ackId=*/m_ackId,
                                  /*segsLeft=*/sourceRoute.GetSegmentsLeft(),
                                  /*expire=*/m_maxMaintainTime);
    bool result = m_maintainBuffer.Enqueue(newEntry);

    if (result)
    {
        NetworkKey networkKey;
        networkKey.m_ackId = newEntry.GetAckId();
        networkKey.m_ourAdd = newEntry.GetOurAdd();
        networkKey.m_nextHop = newEntry.GetNextHop();
        networkKey.m_source = newEntry.GetSrc();
        networkKey.m_destination = newEntry.GetDst();

        PassiveKey passiveKey;
        passiveKey.m_ackId = 0;
        passiveKey.m_source = newEntry.GetSrc();
        passiveKey.m_destination = newEntry.GetDst();
        passiveKey.m_segsLeft = newEntry.GetSegsLeft();

        LinkKey linkKey;
        linkKey.m_source = newEntry.GetSrc();
        linkKey.m_destination = newEntry.GetDst();
        linkKey.m_ourAdd = newEntry.GetOurAdd();
        linkKey.m_nextHop = newEntry.GetNextHop();

        m_addressForwardCnt[networkKey] = 0;
        m_passiveCnt[passiveKey] = 0;
        m_linkCnt[linkKey] = 0;

        if (m_linkAck)
        {
            ScheduleLinkPacketRetry(newEntry, protocol);
        }
        else
        {
            NS_LOG_LOGIC("Not using link acknowledgment");
            if (nextHop != targetAddress)
            {
                SchedulePassivePacketRetry(newEntry, protocol);
            }
            else
            {
                // This is the first network retry
                ScheduleNetworkPacketRetry(newEntry, true, protocol);
            }
        }
    }
}

void
DsrRouting::SendInitialRequest(Ipv4Address source, Ipv4Address destination, uint8_t protocol)
{
    NS_LOG_FUNCTION(this << source << destination << (uint32_t)protocol);
    NS_ASSERT_MSG(!m_downTarget.IsNull(), "Error, DsrRouting cannot send downward");
    Ptr<Packet> packet = Create<Packet>();
    // Create an empty Ipv4 route ptr
    Ptr<Ipv4Route> route;
    /*
     * Construct the route request option header
     */
    DsrRoutingHeader dsrRoutingHeader;
    dsrRoutingHeader.SetNextHeader(protocol);
    dsrRoutingHeader.SetMessageType(1);
    dsrRoutingHeader.SetSourceId(GetIDfromIP(source));
    dsrRoutingHeader.SetDestId(255);

    DsrOptionRreqHeader rreqHeader;           // has an alignment of 4n+0
    rreqHeader.AddNodeAddress(m_mainAddress); // Add our own address in the header
    rreqHeader.SetTarget(destination);
    m_requestId =
        m_rreqTable->CheckUniqueRreqId(destination); // Check the Id cache for duplicate ones
    rreqHeader.SetId(m_requestId);

    dsrRoutingHeader.AddDsrOption(rreqHeader); // Add the rreqHeader to the dsr extension header
    uint8_t length = rreqHeader.GetLength();
    dsrRoutingHeader.SetPayloadLength(uint16_t(length) + 2);
    packet->AddHeader(dsrRoutingHeader);

    // Schedule the route requests retry with non-propagation set true
    bool nonProp = true;
    std::vector<Ipv4Address> address;
    address.push_back(source);
    address.push_back(destination);
    /*
     * Add the socket ip ttl tag to the packet to limit the scope of route requests
     */
    SocketIpTtlTag tag;
    tag.SetTtl(0);
    Ptr<Packet> nonPropPacket = packet->Copy();
    nonPropPacket->AddPacketTag(tag);
    // Increase the request count
    m_rreqTable->FindAndUpdate(destination);
    SendRequest(nonPropPacket, source);
    // Schedule the next route request
    ScheduleRreqRetry(packet, address, nonProp, m_requestId, protocol);
}

void
DsrRouting::SendErrorRequest(DsrOptionRerrUnreachHeader& rerr, uint8_t protocol)
{
    NS_LOG_FUNCTION(this << (uint32_t)protocol);
    NS_ASSERT_MSG(!m_downTarget.IsNull(), "Error, DsrRouting cannot send downward");
    uint8_t salvage = rerr.GetSalvage();
    Ipv4Address dst = rerr.GetOriginalDst();
    NS_LOG_DEBUG("our own address here " << m_mainAddress << " error source " << rerr.GetErrorSrc()
                                         << " error destination " << rerr.GetErrorDst()
                                         << " error next hop " << rerr.GetUnreachNode()
                                         << " original dst " << rerr.GetOriginalDst());
    DsrRouteCacheEntry toDst;
    if (m_routeCache->LookupRoute(dst, toDst))
    {
        /*
         * Found a route the dst, construct the source route option header
         */
        DsrOptionSRHeader sourceRoute;
        std::vector<Ipv4Address> ip = toDst.GetVector();
        sourceRoute.SetNodesAddress(ip);
        /// When found a route and use it, UseExtends to the link cache
        if (m_routeCache->IsLinkCache())
        {
            m_routeCache->UseExtends(ip);
        }
        sourceRoute.SetSegmentsLeft(ip.size() - 2);
        sourceRoute.SetSalvage(salvage);
        Ipv4Address nextHop = SearchNextHop(m_mainAddress, ip); // Get the next hop address
        NS_LOG_DEBUG("The nextHop address " << nextHop);
        Ptr<Packet> packet = Create<Packet>();
        if (nextHop == "0.0.0.0")
        {
            NS_LOG_DEBUG("Error next hop address");
            PacketNewRoute(packet, m_mainAddress, dst, protocol);
            return;
        }
        SetRoute(nextHop, m_mainAddress);
        CancelRreqTimer(dst, true);
        /// Try to send out the packet from the buffer once we found one route
        if (m_sendBuffer.GetSize() != 0 && m_sendBuffer.Find(dst))
        {
            SendPacketFromBuffer(sourceRoute, nextHop, protocol);
        }
        NS_LOG_LOGIC("Route to " << dst << " found");
    }
    else
    {
        NS_LOG_INFO("No route found, initiate route error request");
        Ptr<Packet> packet = Create<Packet>();
        Ipv4Address originalDst = rerr.GetOriginalDst();
        // Create an empty route ptr
        Ptr<Ipv4Route> route = nullptr;
        /*
         * Construct the route request option header
         */
        DsrRoutingHeader dsrRoutingHeader;
        dsrRoutingHeader.SetNextHeader(protocol);
        dsrRoutingHeader.SetMessageType(1);
        dsrRoutingHeader.SetSourceId(GetIDfromIP(m_mainAddress));
        dsrRoutingHeader.SetDestId(255);

        Ptr<Packet> dstP = Create<Packet>();
        DsrOptionRreqHeader rreqHeader;           // has an alignment of 4n+0
        rreqHeader.AddNodeAddress(m_mainAddress); // Add our own address in the header
        rreqHeader.SetTarget(originalDst);
        m_requestId =
            m_rreqTable->CheckUniqueRreqId(originalDst); // Check the Id cache for duplicate ones
        rreqHeader.SetId(m_requestId);

        dsrRoutingHeader.AddDsrOption(rreqHeader); // Add the rreqHeader to the dsr extension header
        dsrRoutingHeader.AddDsrOption(rerr);
        uint8_t length = rreqHeader.GetLength() + rerr.GetLength();
        dsrRoutingHeader.SetPayloadLength(uint16_t(length) + 4);
        dstP->AddHeader(dsrRoutingHeader);
        // Schedule the route requests retry, propagate the route request message as it contains
        // error
        bool nonProp = false;
        std::vector<Ipv4Address> address;
        address.push_back(m_mainAddress);
        address.push_back(originalDst);
        /*
         * Add the socket ip ttl tag to the packet to limit the scope of route requests
         */
        SocketIpTtlTag tag;
        tag.SetTtl((uint8_t)m_discoveryHopLimit);
        Ptr<Packet> propPacket = dstP->Copy();
        propPacket->AddPacketTag(tag);

        if ((m_addressReqTimer.find(originalDst) == m_addressReqTimer.end()) &&
            (m_nonPropReqTimer.find(originalDst) == m_nonPropReqTimer.end()))
        {
            NS_LOG_INFO("Only when there is no existing route request time when the initial route "
                        "request is scheduled");
            SendRequest(propPacket, m_mainAddress);
            ScheduleRreqRetry(dstP, address, nonProp, m_requestId, protocol);
        }
        else
        {
            NS_LOG_INFO("There is existing route request, find the existing route request entry");
            /*
             * Cancel the route request timer first before scheduling the route request
             * in this case, we do not want to remove the route request entry, so the isRemove value
             * is false
             */
            CancelRreqTimer(originalDst, false);
            ScheduleRreqRetry(dstP, address, nonProp, m_requestId, protocol);
        }
    }
}

void
DsrRouting::CancelRreqTimer(Ipv4Address dst, bool isRemove)
{
    NS_LOG_FUNCTION(this << dst << isRemove);
    // Cancel the non propagation request timer if found
    if (m_nonPropReqTimer.find(dst) == m_nonPropReqTimer.end())
    {
        NS_LOG_DEBUG("Did not find the non-propagation timer");
    }
    else
    {
        NS_LOG_DEBUG("did find the non-propagation timer");
    }
    m_nonPropReqTimer[dst].Cancel();

    if (m_nonPropReqTimer[dst].IsRunning())
    {
        NS_LOG_DEBUG("Timer not canceled");
    }
    m_nonPropReqTimer.erase(dst);

    // Cancel the address request timer if found
    if (m_addressReqTimer.find(dst) == m_addressReqTimer.end())
    {
        NS_LOG_DEBUG("Did not find the propagation timer");
    }
    else
    {
        NS_LOG_DEBUG("did find the propagation timer");
    }
    m_addressReqTimer[dst].Cancel();
    if (m_addressReqTimer[dst].IsRunning())
    {
        NS_LOG_DEBUG("Timer not canceled");
    }
    m_addressReqTimer.erase(dst);
    /*
     * If the route request is scheduled to remove the route request entry
     * Remove the route request entry with the route retry times done for certain destination
     */
    if (isRemove)
    {
        // remove the route request entry from route request table
        m_rreqTable->RemoveRreqEntry(dst);
    }
}

void
DsrRouting::ScheduleRreqRetry(Ptr<Packet> packet,
                              std::vector<Ipv4Address> address,
                              bool nonProp,
                              uint32_t requestId,
                              uint8_t protocol)
{
    NS_LOG_FUNCTION(this << packet << nonProp << requestId << (uint32_t)protocol);
    Ipv4Address source = address[0];
    Ipv4Address dst = address[1];
    if (nonProp)
    {
        // The nonProp route request is only sent out only and is already used
        if (m_nonPropReqTimer.find(dst) == m_nonPropReqTimer.end())
        {
            Timer timer(Timer::CANCEL_ON_DESTROY);
            m_nonPropReqTimer[dst] = timer;
        }
        std::vector<Ipv4Address> address;
        address.push_back(source);
        address.push_back(dst);
        m_nonPropReqTimer[dst].SetFunction(&DsrRouting::RouteRequestTimerExpire, this);
        m_nonPropReqTimer[dst].Cancel();
        m_nonPropReqTimer[dst].SetArguments(packet, address, requestId, protocol);
        m_nonPropReqTimer[dst].Schedule(m_nonpropRequestTimeout);
    }
    else
    {
        // Cancel the non propagation request timer if found
        m_nonPropReqTimer[dst].Cancel();
        if (m_nonPropReqTimer[dst].IsRunning())
        {
            NS_LOG_DEBUG("Timer not canceled");
        }
        m_nonPropReqTimer.erase(dst);

        if (m_addressReqTimer.find(dst) == m_addressReqTimer.end())
        {
            Timer timer(Timer::CANCEL_ON_DESTROY);
            m_addressReqTimer[dst] = timer;
        }
        std::vector<Ipv4Address> address;
        address.push_back(source);
        address.push_back(dst);
        m_addressReqTimer[dst].SetFunction(&DsrRouting::RouteRequestTimerExpire, this);
        m_addressReqTimer[dst].Cancel();
        m_addressReqTimer[dst].SetArguments(packet, address, requestId, protocol);
        Time rreqDelay;
        // back off mechanism for sending route requests
        if (m_rreqTable->GetRreqCnt(dst))
        {
            // When the route request count is larger than 0
            // This is the exponential back-off mechanism for route request
            rreqDelay = Time(std::pow(static_cast<double>(m_rreqTable->GetRreqCnt(dst)), 2.0) *
                             m_requestPeriod);
        }
        else
        {
            // This is the first route request retry
            rreqDelay = m_requestPeriod;
        }
        NS_LOG_LOGIC("Request count for " << dst << " " << m_rreqTable->GetRreqCnt(dst)
                                          << " with delay time " << rreqDelay.As(Time::S));
        if (rreqDelay > m_maxRequestPeriod)
        {
            // use the max request period
            NS_LOG_LOGIC("The max request delay time " << m_maxRequestPeriod.As(Time::S));
            m_addressReqTimer[dst].Schedule(m_maxRequestPeriod);
        }
        else
        {
            NS_LOG_LOGIC("The request delay time " << rreqDelay.As(Time::S));
            m_addressReqTimer[dst].Schedule(rreqDelay);
        }
    }
}

void
DsrRouting::RouteRequestTimerExpire(Ptr<Packet> packet,
                                    std::vector<Ipv4Address> address,
                                    uint32_t requestId,
                                    uint8_t protocol)
{
    NS_LOG_FUNCTION(this << packet << requestId << (uint32_t)protocol);
    // Get a clean packet without dsr header
    Ptr<Packet> dsrP = packet->Copy();
    DsrRoutingHeader dsrRoutingHeader;
    dsrP->RemoveHeader(dsrRoutingHeader); // Remove the dsr header in whole

    Ipv4Address source = address[0];
    Ipv4Address dst = address[1];
    DsrRouteCacheEntry toDst;
    if (m_routeCache->LookupRoute(dst, toDst))
    {
        /*
         * Found a route the dst, construct the source route option header
         */
        DsrOptionSRHeader sourceRoute;
        std::vector<Ipv4Address> ip = toDst.GetVector();
        sourceRoute.SetNodesAddress(ip);
        // When we found the route and use it, UseExtends for the link cache
        if (m_routeCache->IsLinkCache())
        {
            m_routeCache->UseExtends(ip);
        }
        sourceRoute.SetSegmentsLeft(ip.size() - 2);
        /// Set the salvage value to 0
        sourceRoute.SetSalvage(0);
        Ipv4Address nextHop = SearchNextHop(m_mainAddress, ip); // Get the next hop address
        NS_LOG_INFO("The nextHop address is " << nextHop);
        if (nextHop == "0.0.0.0")
        {
            NS_LOG_DEBUG("Error next hop address");
            PacketNewRoute(dsrP, source, dst, protocol);
            return;
        }
        SetRoute(nextHop, m_mainAddress);
        CancelRreqTimer(dst, true);
        /// Try to send out data packet from the send buffer if found
        if (m_sendBuffer.GetSize() != 0 && m_sendBuffer.Find(dst))
        {
            SendPacketFromBuffer(sourceRoute, nextHop, protocol);
        }
        NS_LOG_LOGIC("Route to " << dst << " found");
        return;
    }
    /*
     *  If a route discovery has been attempted m_rreqRetries times at the maximum TTL without
     *  receiving any RREP, all data packets destined for the corresponding destination SHOULD be
     *  dropped from the buffer and a Destination Unreachable message SHOULD be delivered to the
     * application.
     */
    NS_LOG_LOGIC("The new request count for " << dst << " is " << m_rreqTable->GetRreqCnt(dst)
                                              << " the max " << m_rreqRetries);
    if (m_rreqTable->GetRreqCnt(dst) >= m_rreqRetries)
    {
        NS_LOG_LOGIC("Route discovery to " << dst << " has been attempted " << m_rreqRetries
                                           << " times");
        CancelRreqTimer(dst, true);
        NS_LOG_DEBUG("Route not found. Drop packet with dst " << dst);
        m_sendBuffer.DropPacketWithDst(dst);
    }
    else
    {
        SocketIpTtlTag tag;
        tag.SetTtl((uint8_t)m_discoveryHopLimit);
        Ptr<Packet> propPacket = packet->Copy();
        propPacket->AddPacketTag(tag);
        // Increase the request count
        m_rreqTable->FindAndUpdate(dst);
        SendRequest(propPacket, source);
        NS_LOG_DEBUG("Check the route request entry " << source << " " << dst);
        ScheduleRreqRetry(packet, address, false, requestId, protocol);
    }
}

void
DsrRouting::SendRequest(Ptr<Packet> packet, Ipv4Address source)
{
    NS_LOG_FUNCTION(this << packet << source);

    NS_ASSERT_MSG(!m_downTarget.IsNull(), "Error, DsrRouting cannot send downward");
    /*
     * The destination address here is directed broadcast address
     */
    uint32_t priority = GetPriority(DSR_CONTROL_PACKET);
    auto i = m_priorityQueue.find(priority);
    Ptr<dsr::DsrNetworkQueue> dsrNetworkQueue = i->second;
    NS_LOG_LOGIC("Inserting into priority queue number: " << priority);

    // m_downTarget (packet, source, m_broadcast, GetProtocolNumber (), 0);

    /// \todo New DsrNetworkQueueEntry
    DsrNetworkQueueEntry newEntry(packet, source, m_broadcast, Simulator::Now(), nullptr);
    if (dsrNetworkQueue->Enqueue(newEntry))
    {
        Scheduler(priority);
    }
    else
    {
        NS_LOG_INFO("Packet dropped as dsr network queue is full");
    }
}

void
DsrRouting::ScheduleInterRequest(Ptr<Packet> packet)
{
    NS_LOG_FUNCTION(this << packet);
    /*
     * This is a forwarding case when sending route requests, a random delay time [0,
     * m_broadcastJitter] used before forwarding as link-layer broadcast
     */
    Simulator::Schedule(MilliSeconds(m_uniformRandomVariable->GetInteger(0, m_broadcastJitter)),
                        &DsrRouting::SendRequest,
                        this,
                        packet,
                        m_mainAddress);
}

void
DsrRouting::SendGratuitousReply(Ipv4Address source,
                                Ipv4Address srcAddress,
                                std::vector<Ipv4Address>& nodeList,
                                uint8_t protocol)
{
    NS_LOG_FUNCTION(this << source << srcAddress << (uint32_t)protocol);
    if (!(m_graReply.FindAndUpdate(source,
                                   srcAddress,
                                   m_gratReplyHoldoff))) // Find the gratuitous reply entry
    {
        NS_LOG_LOGIC("Update gratuitous reply " << source);
        GraReplyEntry graReplyEntry(source, srcAddress, m_gratReplyHoldoff + Simulator::Now());
        m_graReply.AddEntry(graReplyEntry);
        /*
         * Automatic route shortening
         */
        m_finalRoute.clear(); // Clear the final route vector
        /**
         * Push back the node addresses other than those between srcAddress and our own ip address
         */
        auto before = find(nodeList.begin(), nodeList.end(), srcAddress);
        for (auto i = nodeList.begin(); i != before; ++i)
        {
            m_finalRoute.push_back(*i);
        }
        m_finalRoute.push_back(srcAddress);
        auto after = find(nodeList.begin(), nodeList.end(), m_mainAddress);
        for (auto j = after; j != nodeList.end(); ++j)
        {
            m_finalRoute.push_back(*j);
        }
        DsrOptionRrepHeader rrep;
        rrep.SetNodesAddress(m_finalRoute); // Set the node addresses in the route reply header
        // Get the real reply source and destination
        Ipv4Address replySrc = m_finalRoute.back();
        Ipv4Address replyDst = m_finalRoute.front();
        /*
         * Set the route and use it in send back route reply
         */
        m_ipv4Route = SetRoute(srcAddress, m_mainAddress);
        /*
         * This part adds DSR header to the packet and send reply
         */
        DsrRoutingHeader dsrRoutingHeader;
        dsrRoutingHeader.SetNextHeader(protocol);
        dsrRoutingHeader.SetMessageType(1);
        dsrRoutingHeader.SetSourceId(GetIDfromIP(replySrc));
        dsrRoutingHeader.SetDestId(GetIDfromIP(replyDst));

        uint8_t length =
            rrep.GetLength(); // Get the length of the rrep header excluding the type header
        dsrRoutingHeader.SetPayloadLength(uint16_t(length) + 2);
        dsrRoutingHeader.AddDsrOption(rrep);
        Ptr<Packet> newPacket = Create<Packet>();
        newPacket->AddHeader(dsrRoutingHeader);
        /*
         * Send gratuitous reply
         */
        NS_LOG_INFO("Send back gratuitous route reply");
        SendReply(newPacket, m_mainAddress, srcAddress, m_ipv4Route);
    }
    else
    {
        NS_LOG_INFO("The same gratuitous route reply has already sent");
    }
}

void
DsrRouting::SendReply(Ptr<Packet> packet,
                      Ipv4Address source,
                      Ipv4Address nextHop,
                      Ptr<Ipv4Route> route)
{
    NS_LOG_FUNCTION(this << packet << source << nextHop);
    NS_ASSERT_MSG(!m_downTarget.IsNull(), "Error, DsrRouting cannot send downward");

    Ptr<NetDevice> dev = m_ipv4->GetNetDevice(m_ipv4->GetInterfaceForAddress(m_mainAddress));
    route->SetOutputDevice(dev);
    NS_LOG_INFO("The output device " << dev << " packet is: " << *packet);

    uint32_t priority = GetPriority(DSR_CONTROL_PACKET);
    auto i = m_priorityQueue.find(priority);
    Ptr<dsr::DsrNetworkQueue> dsrNetworkQueue = i->second;
    NS_LOG_INFO("Inserting into priority queue number: " << priority);

    // m_downTarget (packet, source, nextHop, GetProtocolNumber (), route);

    /// \todo New DsrNetworkQueueEntry
    DsrNetworkQueueEntry newEntry(packet, source, nextHop, Simulator::Now(), route);
    if (dsrNetworkQueue->Enqueue(newEntry))
    {
        Scheduler(priority);
    }
    else
    {
        NS_LOG_INFO("Packet dropped as dsr network queue is full");
    }
}

void
DsrRouting::ScheduleInitialReply(Ptr<Packet> packet,
                                 Ipv4Address source,
                                 Ipv4Address nextHop,
                                 Ptr<Ipv4Route> route)
{
    NS_LOG_FUNCTION(this << packet << source << nextHop);
    Simulator::ScheduleNow(&DsrRouting::SendReply, this, packet, source, nextHop, route);
}

void
DsrRouting::ScheduleCachedReply(Ptr<Packet> packet,
                                Ipv4Address source,
                                Ipv4Address destination,
                                Ptr<Ipv4Route> route,
                                double hops)
{
    NS_LOG_FUNCTION(this << packet << source << destination);
    Simulator::Schedule(
        Time(2 * m_nodeTraversalTime * (hops - 1 + m_uniformRandomVariable->GetValue(0, 1))),
        &DsrRouting::SendReply,
        this,
        packet,
        source,
        destination,
        route);
}

void
DsrRouting::SendAck(uint16_t ackId,
                    Ipv4Address destination,
                    Ipv4Address realSrc,
                    Ipv4Address realDst,
                    uint8_t protocol,
                    Ptr<Ipv4Route> route)
{
    NS_LOG_FUNCTION(this << ackId << destination << realSrc << realDst << (uint32_t)protocol
                         << route);
    NS_ASSERT_MSG(!m_downTarget.IsNull(), "Error, DsrRouting cannot send downward");

    // This is a route reply option header
    DsrRoutingHeader dsrRoutingHeader;
    dsrRoutingHeader.SetNextHeader(protocol);
    dsrRoutingHeader.SetMessageType(1);
    dsrRoutingHeader.SetSourceId(GetIDfromIP(m_mainAddress));
    dsrRoutingHeader.SetDestId(GetIDfromIP(destination));

    DsrOptionAckHeader ack;
    /*
     * Set the ack Id and set the ack source address and destination address
     */
    ack.SetAckId(ackId);
    ack.SetRealSrc(realSrc);
    ack.SetRealDst(realDst);

    uint8_t length = ack.GetLength();
    dsrRoutingHeader.SetPayloadLength(uint16_t(length) + 2);
    dsrRoutingHeader.AddDsrOption(ack);

    Ptr<Packet> packet = Create<Packet>();
    packet->AddHeader(dsrRoutingHeader);
    Ptr<NetDevice> dev = m_ip->GetNetDevice(m_ip->GetInterfaceForAddress(m_mainAddress));
    route->SetOutputDevice(dev);

    uint32_t priority = GetPriority(DSR_CONTROL_PACKET);
    auto i = m_priorityQueue.find(priority);
    Ptr<dsr::DsrNetworkQueue> dsrNetworkQueue = i->second;

    NS_LOG_LOGIC("Will be inserting into priority queue " << dsrNetworkQueue
                                                          << " number: " << priority);

    // m_downTarget (packet, m_mainAddress, destination, GetProtocolNumber (), route);

    /// \todo New DsrNetworkQueueEntry
    DsrNetworkQueueEntry newEntry(packet, m_mainAddress, destination, Simulator::Now(), route);
    if (dsrNetworkQueue->Enqueue(newEntry))
    {
        Scheduler(priority);
    }
    else
    {
        NS_LOG_INFO("Packet dropped as dsr network queue is full");
    }
}

IpL4Protocol::RxStatus
DsrRouting::Receive(Ptr<Packet> p, const Ipv4Header& ip, Ptr<Ipv4Interface> incomingInterface)
{
    NS_LOG_FUNCTION(this << p << ip << incomingInterface);

    NS_LOG_INFO("Our own IP address " << m_mainAddress << " The incoming interface address "
                                      << incomingInterface);
    m_node = GetNode();             // Get the node
    Ptr<Packet> packet = p->Copy(); // Save a copy of the received packet
    /*
     * When forwarding or local deliver packets, this one should be used always!!
     */
    DsrRoutingHeader dsrRoutingHeader;
    packet->RemoveHeader(dsrRoutingHeader); // Remove the DSR header in whole
    Ptr<Packet> copy = packet->Copy();

    uint8_t protocol = dsrRoutingHeader.GetNextHeader();
    uint32_t sourceId = dsrRoutingHeader.GetSourceId();
    Ipv4Address source = GetIPfromID(sourceId);
    NS_LOG_INFO("The source address " << source << " with source id " << sourceId);
    /*
     * Get the IP source and destination address
     */
    Ipv4Address src = ip.GetSource();

    bool isPromisc = false;
    uint32_t offset =
        dsrRoutingHeader
            .GetDsrOptionsOffset(); // Get the offset for option header, 8 bytes in this case

    // This packet is used to peek option type
    p->RemoveAtStart(offset);

    Ptr<dsr::DsrOptions> dsrOption;
    DsrOptionHeader dsrOptionHeader;
    /*
     * Peek data to get the option type as well as length and segmentsLeft field
     */
    uint32_t size = p->GetSize();
    auto data = new uint8_t[size];
    p->CopyData(data, size);

    uint8_t optionType = 0;
    uint8_t optionLength = 0;
    uint8_t segmentsLeft = 0;

    optionType = *(data);
    NS_LOG_LOGIC("The option type value " << (uint32_t)optionType << " with packet id "
                                          << p->GetUid());
    dsrOption =
        GetOption(optionType); // Get the relative dsr option and demux to the process function
    Ipv4Address promiscSource; /// this is just here for the sake of passing in the promisc source
    if (optionType == 1)       // This is the request option
    {
        BlackList* blackList = m_rreqTable->FindUnidirectional(src);
        if (blackList)
        {
            NS_LOG_INFO("Discard this packet due to unidirectional link");
            m_dropTrace(p);
        }

        dsrOption = GetOption(optionType);
        optionLength =
            dsrOption
                ->Process(p, packet, m_mainAddress, source, ip, protocol, isPromisc, promiscSource);

        if (optionLength == 0)
        {
            NS_LOG_INFO("Discard this packet");
            m_dropTrace(p);
        }
    }
    else if (optionType == 2)
    {
        dsrOption = GetOption(optionType);
        optionLength =
            dsrOption
                ->Process(p, packet, m_mainAddress, source, ip, protocol, isPromisc, promiscSource);

        if (optionLength == 0)
        {
            NS_LOG_INFO("Discard this packet");
            m_dropTrace(p);
        }
    }

    else if (optionType == 32) // This is the ACK option
    {
        NS_LOG_INFO("This is the ack option");
        dsrOption = GetOption(optionType);
        optionLength =
            dsrOption
                ->Process(p, packet, m_mainAddress, source, ip, protocol, isPromisc, promiscSource);

        if (optionLength == 0)
        {
            NS_LOG_INFO("Discard this packet");
            m_dropTrace(p);
        }
    }

    else if (optionType == 3) // This is a route error header
    {
        // populate this route error
        NS_LOG_INFO("The option type value " << (uint32_t)optionType);

        dsrOption = GetOption(optionType);
        optionLength =
            dsrOption
                ->Process(p, packet, m_mainAddress, source, ip, protocol, isPromisc, promiscSource);

        if (optionLength == 0)
        {
            NS_LOG_INFO("Discard this packet");
            m_dropTrace(p);
        }
        NS_LOG_INFO("The option Length " << (uint32_t)optionLength);
    }

    else if (optionType == 96) // This is the source route option
    {
        dsrOption = GetOption(optionType);
        optionLength =
            dsrOption
                ->Process(p, packet, m_mainAddress, source, ip, protocol, isPromisc, promiscSource);
        segmentsLeft = data[3];
        if (optionLength == 0)
        {
            NS_LOG_INFO("Discard this packet");
            m_dropTrace(p);
        }
        else
        {
            if (segmentsLeft == 0)
            {
                // / Get the next header
                uint8_t nextHeader = dsrRoutingHeader.GetNextHeader();
                Ptr<Ipv4L3Protocol> l3proto = m_node->GetObject<Ipv4L3Protocol>();
                Ptr<IpL4Protocol> nextProto = l3proto->GetProtocol(nextHeader);
                if (!nextProto)
                {
                    NS_FATAL_ERROR("Should not have 0 next protocol value");
                }

                // we need to make a copy in the unlikely event we hit the
                // RX_ENDPOINT_UNREACH code path
                // Here we can use the packet that has been get off whole DSR header
                IpL4Protocol::RxStatus status = nextProto->Receive(copy, ip, incomingInterface);
                NS_LOG_DEBUG("The receive status " << status);
                switch (status)
                {
                case IpL4Protocol::RX_OK:
                // fall through
                case IpL4Protocol::RX_ENDPOINT_CLOSED:
                // fall through
                case IpL4Protocol::RX_CSUM_FAILED:
                    break;
                case IpL4Protocol::RX_ENDPOINT_UNREACH:
                    if (ip.GetDestination().IsBroadcast() || ip.GetDestination().IsMulticast())
                    {
                        break; // Do not reply to broadcast or multicast
                    }
                    // Another case to suppress ICMP is a subnet-directed broadcast
                }
                return status;
            }
            else
            {
                NS_LOG_INFO("This is not the final destination, the packet has already been "
                            "forward to next hop");
            }
        }
    }
    else
    {
        NS_LOG_LOGIC("Unknown Option. Drop!");
        /*
         * Initialize the salvage value to 0
         */
        uint8_t salvage = 0;

        DsrOptionRerrUnsupportedHeader rerrUnsupportedHeader;
        rerrUnsupportedHeader.SetErrorType(3); // The error type 3 means Option not supported
        rerrUnsupportedHeader.SetErrorSrc(
            m_mainAddress); // The error source address is our own address
        rerrUnsupportedHeader.SetUnsupported(optionType); // The unsupported option type number
        rerrUnsupportedHeader.SetErrorDst(
            src); // Error destination address is the destination of the data packet
        rerrUnsupportedHeader.SetSalvage(
            salvage); // Set the value about whether to salvage a packet or not

        /*
         * The unknown option error is not supported currently in this implementation, and it's also
         * not likely to happen in simulations
         */
        //            SendError (rerrUnsupportedHeader, 0, protocol); // Send the error packet
    }
    return IpL4Protocol::RX_OK;
}

IpL4Protocol::RxStatus
DsrRouting::Receive(Ptr<Packet> p, const Ipv6Header& ip, Ptr<Ipv6Interface> incomingInterface)
{
    NS_LOG_FUNCTION(this << p << ip.GetSource() << ip.GetDestination() << incomingInterface);
    return IpL4Protocol::RX_ENDPOINT_UNREACH;
}

void
DsrRouting::SetDownTarget(DownTargetCallback callback)
{
    m_downTarget = callback;
}

void
DsrRouting::SetDownTarget6(DownTargetCallback6 callback)
{
    NS_FATAL_ERROR("Unimplemented");
}

IpL4Protocol::DownTargetCallback
DsrRouting::GetDownTarget() const
{
    return m_downTarget;
}

IpL4Protocol::DownTargetCallback6
DsrRouting::GetDownTarget6() const
{
    NS_FATAL_ERROR("Unimplemented");
    return MakeNullCallback<void, Ptr<Packet>, Ipv6Address, Ipv6Address, uint8_t, Ptr<Ipv6Route>>();
}

void
DsrRouting::Insert(Ptr<dsr::DsrOptions> option)
{
    m_options.push_back(option);
}

Ptr<dsr::DsrOptions>
DsrRouting::GetOption(int optionNumber)
{
    for (auto i = m_options.begin(); i != m_options.end(); ++i)
    {
        if ((*i)->GetOptionNumber() == optionNumber)
        {
            return *i;
        }
    }
    return nullptr;
}
} /* namespace dsr */
} /* namespace ns3 */
