wimax-mac-queue.cc

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/*
 * Copyright (c) 2007,2008 INRIA, UDcast
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 * Author: Jahanzeb Farooq <jahanzeb.farooq@sophia.inria.fr>
 *         Mohamed Amine Ismail <Amine.Ismail@sophia.inria.fr>
 *                              <Amine.Ismail@UDcast.com>
 */
 
#include "wimax-mac-queue.h"
 
#include "ns3/log.h"
#include "ns3/packet.h"
#include "ns3/simulator.h"
#include "ns3/trace-source-accessor.h"
#include "ns3/uinteger.h"
 
namespace ns3
{
 
NS_LOG_COMPONENT_DEFINE("WimaxMacQueue");
 
NS_OBJECT_ENSURE_REGISTERED(WimaxMacQueue);
 
WimaxMacQueue::QueueElement::QueueElement()
    : m_packet(Create<Packet>()),
      m_hdrType(MacHeaderType()),
      m_hdr(GenericMacHeader()),
      m_timeStamp(Seconds(0)),
      m_fragmentation(false),
      m_fragmentNumber(0),
      m_fragmentOffset(0)
{
}
 
WimaxMacQueue::QueueElement::QueueElement(Ptr<Packet> packet,
                                          const MacHeaderType& hdrType,
                                          const GenericMacHeader& hdr,
                                          Time timeStamp)
    : m_packet(packet),
      m_hdrType(hdrType),
      m_hdr(hdr),
      m_timeStamp(timeStamp),
      m_fragmentation(false),
      m_fragmentNumber(0),
      m_fragmentOffset(0)
{
}
 
uint32_t
WimaxMacQueue::QueueElement::GetSize() const
{
    uint32_t size = m_packet->GetSize() + m_hdrType.GetSerializedSize();
 
    /*check because may be it is a bandwidth request packet (in which case a Bandwidth Request
     Header has already been added to the packet) in which case Generic MAC Header will not be added
     to it. this will only happen in the case of SS as only SS sends the bandwidth request packet.
   */
    if (m_hdrType.GetType() == MacHeaderType::HEADER_TYPE_GENERIC)
    {
        size += m_hdr.GetSerializedSize();
    }
 
    return size;
}
 
TypeId
WimaxMacQueue::GetTypeId()
{
    static TypeId tid = TypeId("ns3::WimaxMacQueue")
                            .SetParent<Object>()
                            .SetGroupName("Wimax")
                            .AddAttribute("MaxSize",
                                          "Maximum size",
                                          UintegerValue(1024),
                                          MakeUintegerAccessor(&WimaxMacQueue::GetMaxSize,
                                                               &WimaxMacQueue::SetMaxSize),
                                          MakeUintegerChecker<uint32_t>())
                            .AddTraceSource("Enqueue",
                                            "Enqueue trace",
                                            MakeTraceSourceAccessor(&WimaxMacQueue::m_traceEnqueue),
                                            "ns3::Packet::TracedCallback")
                            .AddTraceSource("Dequeue",
                                            "Dequeue trace",
                                            MakeTraceSourceAccessor(&WimaxMacQueue::m_traceDequeue),
                                            "ns3::Packet::TracedCallback")
                            .AddTraceSource("Drop",
                                            "Drop trace",
                                            MakeTraceSourceAccessor(&WimaxMacQueue::m_traceDrop),
                                            "ns3::Packet::TracedCallback");
    return tid;
}
 
WimaxMacQueue::WimaxMacQueue()
    : m_maxSize(0),
      m_bytes(0),
      m_nrDataPackets(0),
      m_nrRequestPackets(0)
{
}
 
WimaxMacQueue::WimaxMacQueue(uint32_t maxSize)
    : m_maxSize(maxSize),
      m_bytes(0),
      m_nrDataPackets(0),
      m_nrRequestPackets(0)
{
}
 
WimaxMacQueue::~WimaxMacQueue()
{
}
 
void
WimaxMacQueue::SetMaxSize(uint32_t maxSize)
{
    m_maxSize = maxSize;
}
 
uint32_t
WimaxMacQueue::GetMaxSize() const
{
    return m_maxSize;
}
 
bool
WimaxMacQueue::Enqueue(Ptr<Packet> packet,
                       const MacHeaderType& hdrType,
                       const GenericMacHeader& hdr)
{
    if (m_queue.size() == m_maxSize)
    {
        m_traceDrop(packet);
        return false;
    }
 
    m_traceEnqueue(packet);
    QueueElement element(packet, hdrType, hdr, Simulator::Now());
    m_queue.push_back(element);
 
    if (hdrType.GetType() == MacHeaderType::HEADER_TYPE_GENERIC)
    {
        m_nrDataPackets++;
    }
    else
    {
        m_nrRequestPackets++;
    }
 
    m_bytes += element.GetSize();
    return true;
}
 
Ptr<Packet>
WimaxMacQueue::Dequeue(MacHeaderType::HeaderType packetType)
{
    if (!IsEmpty())
    {
        QueueElement element = Front(packetType);
        Pop(packetType);
 
        if (element.m_hdrType.GetType() == MacHeaderType::HEADER_TYPE_GENERIC)
        {
            NS_LOG_INFO("Enqueued Packet IS A data packet");
            NS_ASSERT_MSG(m_nrDataPackets >= 1,
                          "Can not enqueue more packets: no space left in the queue");
            m_nrDataPackets--;
        }
        else
        {
            NS_LOG_INFO("Enqueued Packet IS A Request BW packet");
            NS_ASSERT_MSG(m_nrRequestPackets >= 1,
                          "Can not enqueue more packets: no space left in the queue");
            m_nrRequestPackets--;
        }
 
        Ptr<Packet> packet = element.m_packet;
 
        if (!element.m_fragmentation)
        {
            NS_LOG_INFO("FRAG_DEBUG: Enqueued Packet IS NOT a fragment" << std::endl);
            /*check because may be it is a bandwidth request packet (in which case a Bandwidth
              Request Header has already been added to the packet) in which case Generic MAC Header
              will not be added to it. this will only happen in the case of SS as only SS sends the
              bandwidth request packet. */
            m_bytes -= element.GetSize();
            if (element.m_hdrType.GetType() == MacHeaderType::HEADER_TYPE_GENERIC)
            {
                packet->AddHeader(element.m_hdr);
            }
            packet->AddHeader(element.m_hdrType);
 
            m_traceDequeue(packet);
            return packet;
        }
        else
        {
            /*
             The enqueued packet is a fragment (the latest fragment)
             We must modify type field of the m_hdr and add a fragmentation Subhdr
             */
            NS_LOG_INFO("\t Enqueued Packet IS a fragment, add subhdr" << std::endl);
 
            // Create a fragment
            uint32_t fragmentOffset = element.m_fragmentOffset;
            uint32_t fragmentSize = element.m_packet->GetSize() - fragmentOffset;
 
            NS_LOG_INFO("\t Create a fragment"
                        "\n\t\t fragmentOffset="
                        << fragmentOffset << "\n\t\t packetSize=" << element.m_packet->GetSize()
                        << "\n\t\t fragmentSize=" << fragmentSize << std::endl);
 
            Ptr<Packet> fragment = packet->CreateFragment(fragmentOffset, fragmentSize);
 
            FragmentationSubheader fragmentSubhdr;
            NS_LOG_INFO("\t Latest Fragment" << std::endl);
            fragmentSubhdr.SetFc(2); // This is the latest fragment
            fragmentSubhdr.SetFsn(element.m_fragmentNumber);
 
            NS_LOG_INFO("\t FragmentSize=" << fragment->GetSize() << std::endl);
            fragment->AddHeader(fragmentSubhdr);
 
            /*check because may be it is a bandwidth request packet (in which case a Bandwidth
            Request Header has already been added to the packet) in which case Generic MAC Header
            will not be added to it. this will only happen in the case of SS as only SS sends the
            bandwidth request packet. */
            if (element.m_hdrType.GetType() == MacHeaderType::HEADER_TYPE_GENERIC)
            {
                uint8_t tmpType = element.m_hdr.GetType();
                tmpType |= 4;
                element.m_hdr.SetType(tmpType);
 
                uint32_t length = fragmentSize + element.m_hdr.GetSerializedSize() +
                                  fragmentSubhdr.GetSerializedSize();
                element.m_hdr.SetLen((uint16_t)length);
 
                fragment->AddHeader(element.m_hdr);
            }
            fragment->AddHeader(element.m_hdrType);
            m_bytes -= fragmentSize;
 
            m_traceDequeue(fragment);
            return fragment;
        }
    }
    return nullptr;
}
 
Ptr<Packet>
WimaxMacQueue::Dequeue(MacHeaderType::HeaderType packetType, uint32_t availableByte)
{
    if (!IsEmpty())
    {
        NS_LOG_INFO("FRAG_DEBUG: Dequeue function" << std::endl);
        QueueElement element = Front(packetType);
 
        uint32_t headerSize =
            2 + element.m_hdr.GetSerializedSize() + element.m_hdrType.GetSerializedSize();
 
        // Create a fragment
        uint32_t maxFragmentSize = availableByte - headerSize;
        uint32_t fragmentOffset = element.m_fragmentOffset; // It is the latest byte sent.
 
        Ptr<Packet> packet = element.m_packet->Copy();
        NS_LOG_INFO("\t Create a fragment"
                    "\n\t\t availableByte="
                    << availableByte << "\n\t\t headerSize=" << headerSize
                    << "\n\t\t maxFragmentSize=" << maxFragmentSize
                    << ""
                       "\n\t\t fragmentOffset="
                    << fragmentOffset << "\n\t\t payloadSize=" << packet->GetSize() << std::endl);
        Ptr<Packet> fragment = packet->CreateFragment(fragmentOffset, maxFragmentSize);
        m_bytes -= maxFragmentSize;
 
        FragmentationSubheader fragmentSubhdr;
        if (!element.m_fragmentation)
        {
            NS_LOG_INFO("\t First Fragment" << std::endl);
            SetFragmentation(packetType);
            fragmentSubhdr.SetFc(1);
        }
        else
        {
            NS_LOG_INFO("\t Middle Fragment" << std::endl);
            fragmentSubhdr.SetFc(3);
        }
        fragmentSubhdr.SetFsn(element.m_fragmentNumber);
        NS_LOG_INFO("\t FragmentSize=" << fragment->GetSize() << std::endl);
        fragment->AddHeader(fragmentSubhdr);
 
        SetFragmentNumber(packetType);
        SetFragmentOffset(packetType, maxFragmentSize);
 
        /*check because may be it is a bandwidth request packet (in which case a Bandwidth Request
          Header has already been added to the packet) in which case Generic MAC Header will not be
          added to it. this will only happen in the case of SS as only SS sends the bandwidth
          request packet. */
        if (element.m_hdrType.GetType() == MacHeaderType::HEADER_TYPE_GENERIC)
        {
            uint8_t tmpType = element.m_hdr.GetType();
            tmpType |= 4;
            element.m_hdr.SetType(tmpType);
 
            uint32_t length = maxFragmentSize + element.m_hdr.GetSerializedSize() +
                              fragmentSubhdr.GetSerializedSize();
            element.m_hdr.SetLen((uint16_t)length);
 
            fragment->AddHeader(element.m_hdr);
        }
        fragment->AddHeader(element.m_hdrType);
 
        m_traceDequeue(fragment);
        return fragment;
    }
    return nullptr;
}
 
Ptr<Packet>
WimaxMacQueue::Peek(GenericMacHeader& hdr) const
{
    if (!IsEmpty())
    {
        QueueElement element = m_queue.front();
        hdr = element.m_hdr;
        Ptr<Packet> packet = element.m_packet->Copy();
 
        // this function must not be used by SS as it may be then a bandwidth request header
        packet->AddHeader(element.m_hdr);
        return packet;
    }
 
    return nullptr;
}
 
Ptr<Packet>
WimaxMacQueue::Peek(GenericMacHeader& hdr, Time& timeStamp) const
{
    if (!IsEmpty())
    {
        QueueElement element = m_queue.front();
        hdr = element.m_hdr;
        timeStamp = element.m_timeStamp;
        Ptr<Packet> packet = element.m_packet->Copy();
 
        // this function must not be used for by SS as it may be then a bandwidth request header
        packet->AddHeader(element.m_hdr);
        return packet;
    }
 
    return nullptr;
}
 
Ptr<Packet>
WimaxMacQueue::Peek(MacHeaderType::HeaderType packetType) const
{
    if (!IsEmpty())
    {
        QueueElement element = Front(packetType);
        Ptr<Packet> packet = element.m_packet->Copy();
 
        /*check because may be it is a bandwidth request packet (in which case a Bandwidth Request
         Header has already been added to the packet) in which case Generic MAC Header will not be
         added to it. this will only happen in the case of SS as only SS sends the bandwidth request
         packet. */
        if (element.m_hdrType.GetType() == MacHeaderType::HEADER_TYPE_GENERIC)
        {
            packet->AddHeader(element.m_hdr);
        }
        return packet;
    }
 
    return nullptr;
}
 
Ptr<Packet>
WimaxMacQueue::Peek(MacHeaderType::HeaderType packetType, Time& timeStamp) const
{
    if (!IsEmpty())
    {
        QueueElement element = Front(packetType);
        timeStamp = element.m_timeStamp;
        Ptr<Packet> packet = element.m_packet->Copy();
 
        /*check because may be it is a bandwidth request packet (in which case a Bandwidth Request
         Header has already been added to the packet) in which case Generic MAC Header will not be
         added to it. this will only happen in the case of SS as only SS sends the bandwidth request
         packet. */
        if (element.m_hdrType.GetType() == MacHeaderType::HEADER_TYPE_GENERIC)
        {
            packet->AddHeader(element.m_hdr);
        }
        return packet;
    }
 
    return nullptr;
}
 
uint32_t
WimaxMacQueue::GetSize() const
{
    return m_queue.size();
}
 
uint32_t
WimaxMacQueue::GetNBytes() const
{
    return m_bytes;
}
 
uint32_t
WimaxMacQueue::GetQueueLengthWithMACOverhead()
{
    uint32_t queueSize = GetNBytes();
    // Add MAC Overhead
    queueSize += GetSize() * 6;
    MacHeaderType::HeaderType packetType = MacHeaderType::HEADER_TYPE_GENERIC;
    if (CheckForFragmentation(packetType))
    {
        queueSize += 2;
    }
    return queueSize;
}
 
WimaxMacQueue::QueueElement
WimaxMacQueue::Front(MacHeaderType::HeaderType packetType) const
{
    QueueElement element;
 
    for (auto iter = m_queue.begin(); iter != m_queue.end(); ++iter)
    {
        element = *iter;
        if (element.m_hdrType.GetType() == packetType)
        {
            break;
        }
    }
 
    return element;
}
 
void
WimaxMacQueue::Pop(MacHeaderType::HeaderType packetType)
{
    QueueElement element;
 
    for (auto iter = m_queue.begin(); iter != m_queue.end(); ++iter)
    {
        element = *iter;
        if (element.m_hdrType.GetType() == packetType)
        {
            m_queue.erase(iter);
            break;
        }
    }
}
 
bool
WimaxMacQueue::IsEmpty() const
{
    return m_queue.empty();
}
 
bool
WimaxMacQueue::IsEmpty(MacHeaderType::HeaderType packetType) const
{
    if (packetType == MacHeaderType::HEADER_TYPE_GENERIC)
    {
        return m_nrDataPackets == 0;
    }
    else
    {
        return m_nrRequestPackets == 0;
    }
 
    return true;
}
 
const WimaxMacQueue::PacketQueue&
WimaxMacQueue::GetPacketQueue() const
{
    return m_queue;
}
 
bool
WimaxMacQueue::CheckForFragmentation(MacHeaderType::HeaderType packetType)
{
    QueueElement element;
    for (auto iter = m_queue.begin(); iter != m_queue.end(); ++iter)
    {
        element = *iter;
        if (element.m_hdrType.GetType() == packetType)
        {
            break;
        }
    }
 
    if (element.m_fragmentation)
    {
        NS_LOG_INFO("FRAG_DEBUG: CheckForFragmentation"
                    "\n\t\t m_fragmentation is true "
                    << std::endl);
    }
 
    return element.m_fragmentation;
}
 
uint32_t
WimaxMacQueue::GetFirstPacketHdrSize(MacHeaderType::HeaderType packetType)
{
    QueueElement element;
    for (auto iter = m_queue.begin(); iter != m_queue.end(); ++iter)
    {
        element = *iter;
        if (element.m_hdrType.GetType() == packetType)
        {
            break;
        }
    }
 
    NS_LOG_INFO("\t\t GetFirstPacketHdrSize ()");
 
    uint32_t hdrSize = 0;
    if (element.m_hdrType.GetType() == MacHeaderType::HEADER_TYPE_GENERIC)
    {
        hdrSize += element.m_hdr.GetSerializedSize();
        NS_LOG_INFO("\t\t\t m_hdr.GetSerializedSize=" << element.m_hdr.GetSerializedSize());
    }
 
    hdrSize += element.m_hdrType.GetSerializedSize();
    NS_LOG_INFO("\t\t\t m_hdrType.GetSerializedSize=" << element.m_hdrType.GetSerializedSize());
 
    if (CheckForFragmentation(packetType))
    {
        NS_LOG_INFO("\t\t\t fragSubhdrSize=2");
        hdrSize += 2;
    }
 
    NS_LOG_INFO("\t\t hdrSize=" << hdrSize);
 
    return hdrSize;
}
 
uint32_t
WimaxMacQueue::GetFirstPacketPayloadSize(MacHeaderType::HeaderType packetType)
{
    QueueElement element;
    for (auto iter = m_queue.begin(); iter != m_queue.end(); ++iter)
    {
        element = *iter;
        if (element.m_hdrType.GetType() == packetType)
        {
            break;
        }
    }
 
    NS_LOG_INFO("\t\t GetFirstPacketPayloadSize ()");
 
    if (CheckForFragmentation(packetType))
    {
        NS_LOG_INFO("\t\t\t fullPayloadSize="
                    << element.m_packet->GetSize() << "\n\t\t\t fragmentOffset="
                    << element.m_fragmentOffset << "\n\t\t\t (fragment)payloadSize="
                    << element.m_packet->GetSize() - element.m_fragmentOffset);
 
        return element.m_packet->GetSize() - element.m_fragmentOffset;
    }
    NS_LOG_INFO("\t\t payloadSize=" << element.m_packet->GetSize());
 
    return element.m_packet->GetSize();
}
 
uint32_t
WimaxMacQueue::GetFirstPacketRequiredByte(MacHeaderType::HeaderType packetType)
{
    NS_LOG_INFO("\t GetFirstPacketRequiredByte ()");
 
    uint32_t requiredByte =
        GetFirstPacketPayloadSize(packetType) + GetFirstPacketHdrSize(packetType);
 
    NS_LOG_INFO("\t Required Bytes = " << requiredByte << std::endl);
 
    return requiredByte;
}
 
void
WimaxMacQueue::SetFragmentation(MacHeaderType::HeaderType packetType)
{
    for (auto iter = m_queue.begin(); iter != m_queue.end(); ++iter)
    {
        if (iter->m_hdrType.GetType() == packetType)
        {
            iter->SetFragmentation();
            break;
        }
    }
}
 
void
WimaxMacQueue::SetFragmentNumber(MacHeaderType::HeaderType packetType)
{
    for (auto iter = m_queue.begin(); iter != m_queue.end(); ++iter)
    {
        if (iter->m_hdrType.GetType() == packetType)
        {
            iter->SetFragmentNumber();
            break;
        }
    }
}
 
void
WimaxMacQueue::SetFragmentOffset(MacHeaderType::HeaderType packetType, uint32_t offset)
{
    for (auto iter = m_queue.begin(); iter != m_queue.end(); ++iter)
    {
        if (iter->m_hdrType.GetType() == packetType)
        {
            iter->SetFragmentOffset(offset);
            break;
        }
    }
}
 
void
WimaxMacQueue::QueueElement::SetFragmentation()
{
    m_fragmentation = true;
}
 
void
WimaxMacQueue::QueueElement::SetFragmentNumber()
{
    m_fragmentNumber++;
}
 
void
WimaxMacQueue::QueueElement::SetFragmentOffset(uint32_t offset)
{
    m_fragmentOffset += offset;
}
} // namespace ns3