wifi-mpdu.cc

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/*
 * Copyright (c) 2005, 2009 INRIA
 * Copyright (c) 2009 MIRKO BANCHI
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation;
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Authors: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
 *          Mirko Banchi <mk.banchi@gmail.com>
 *          Stefano Avallone <stavallo@unina.it>
 */
 
#include "wifi-mpdu.h"
 
#include "msdu-aggregator.h"
#include "wifi-mac-trailer.h"
#include "wifi-utils.h"
 
#include "ns3/log.h"
#include "ns3/packet.h"
#include "ns3/simulator.h"
 
namespace ns3
{
 
NS_LOG_COMPONENT_DEFINE("WifiMpdu");
 
WifiMpdu::WifiMpdu(Ptr<const Packet> p, const WifiMacHeader& header)
    : m_packet(p),
      m_header(header)
{
    if (header.IsQosData() && header.IsQosAmsdu())
    {
        m_msduList = MsduAggregator::Deaggregate(p->Copy());
    }
    m_inFlight = false;
}
 
WifiMpdu::~WifiMpdu()
{
}
 
Ptr<const Packet>
WifiMpdu::GetPacket() const
{
    return m_packet;
}
 
const WifiMacHeader&
WifiMpdu::GetHeader() const
{
    return m_header;
}
 
WifiMacHeader&
WifiMpdu::GetHeader()
{
    return m_header;
}
 
Mac48Address
WifiMpdu::GetDestinationAddress() const
{
    return m_header.GetAddr1();
}
 
uint32_t
WifiMpdu::GetPacketSize() const
{
    return m_packet->GetSize();
}
 
uint32_t
WifiMpdu::GetSize() const
{
    return GetPacketSize() + m_header.GetSerializedSize() + WIFI_MAC_FCS_LENGTH;
}
 
bool
WifiMpdu::IsFragment() const
{
    return m_header.IsMoreFragments() || m_header.GetFragmentNumber() > 0;
}
 
Ptr<Packet>
WifiMpdu::GetProtocolDataUnit() const
{
    Ptr<Packet> mpdu = m_packet->Copy();
    mpdu->AddHeader(m_header);
    AddWifiMacTrailer(mpdu);
    return mpdu;
}
 
void
WifiMpdu::Aggregate(Ptr<const WifiMpdu> msdu)
{
    NS_ASSERT(msdu);
    NS_LOG_FUNCTION(this << *msdu);
    NS_ABORT_MSG_IF(!msdu->GetHeader().IsQosData() || msdu->GetHeader().IsQosAmsdu(),
                    "Only QoS data frames that do not contain an A-MSDU can be aggregated");
 
    if (m_msduList.empty())
    {
        // An MSDU is going to be aggregated to this MPDU, hence this has to be an A-MSDU now
        Ptr<const WifiMpdu> firstMsdu = Create<const WifiMpdu>(*this);
        m_packet = Create<Packet>();
        DoAggregate(firstMsdu);
 
        m_header.SetQosAmsdu();
        // Set Address3 according to Table 9-26 of 802.11-2016
        if (m_header.IsToDs() && !m_header.IsFromDs())
        {
            // from STA to AP: BSSID is in Address1
            m_header.SetAddr3(m_header.GetAddr1());
        }
        else if (!m_header.IsToDs() && m_header.IsFromDs())
        {
            // from AP to STA: BSSID is in Address2
            m_header.SetAddr3(m_header.GetAddr2());
        }
        // in the WDS case (ToDS = FromDS = 1), both Address 3 and Address 4 need
        // to be set to the BSSID, but neither Address 1 nor Address 2 contain the
        // BSSID. Hence, it is left up to the caller to set these Address fields.
    }
    DoAggregate(msdu);
}
 
void
WifiMpdu::DoAggregate(Ptr<const WifiMpdu> msdu)
{
    NS_LOG_FUNCTION(this << *msdu);
 
    // build the A-MSDU Subframe header
    AmsduSubframeHeader hdr;
    /*
     * (See Table 9-26 of 802.11-2016)
     *
     * ToDS | FromDS |  DA   |  SA
     *   0  |   0    | Addr1 | Addr2
     *   0  |   1    | Addr1 | Addr3
     *   1  |   0    | Addr3 | Addr2
     *   1  |   1    | Addr3 | Addr4
     */
    hdr.SetDestinationAddr(msdu->GetHeader().IsToDs() ? msdu->GetHeader().GetAddr3()
                                                      : msdu->GetHeader().GetAddr1());
    hdr.SetSourceAddr(!msdu->GetHeader().IsFromDs()
                          ? msdu->GetHeader().GetAddr2()
                          : (!msdu->GetHeader().IsToDs() ? msdu->GetHeader().GetAddr3()
                                                         : msdu->GetHeader().GetAddr4()));
    hdr.SetLength(static_cast<uint16_t>(msdu->GetPacket()->GetSize()));
 
    m_msduList.emplace_back(msdu->GetPacket(), hdr);
 
    // build the A-MSDU
    NS_ASSERT(m_packet);
    Ptr<Packet> amsdu = m_packet->Copy();
 
    // pad the previous A-MSDU subframe if the A-MSDU is not empty
    if (m_packet->GetSize() > 0)
    {
        uint8_t padding = MsduAggregator::CalculatePadding(m_packet->GetSize());
 
        if (padding)
        {
            amsdu->AddAtEnd(Create<Packet>(padding));
        }
    }
 
    // add A-MSDU subframe header and MSDU
    Ptr<Packet> amsduSubframe = msdu->GetPacket()->Copy();
    amsduSubframe->AddHeader(hdr);
    amsdu->AddAtEnd(amsduSubframe);
    m_packet = amsdu;
}
 
bool
WifiMpdu::IsQueued() const
{
    return m_queueIt.has_value();
}
 
void
WifiMpdu::SetQueueIt(std::optional<Iterator> queueIt, WmqIteratorTag tag)
{
    m_queueIt = queueIt;
}
 
WifiMpdu::Iterator
WifiMpdu::GetQueueIt(WmqIteratorTag tag) const
{
    NS_ASSERT(IsQueued());
    return m_queueIt.value();
}
 
AcIndex
WifiMpdu::GetQueueAc() const
{
    NS_ASSERT(IsQueued());
    return (*m_queueIt)->ac;
}
 
Time
WifiMpdu::GetExpiryTime() const
{
    NS_ASSERT(IsQueued());
    return (*m_queueIt)->expiryTime;
}
 
void
WifiMpdu::SetInFlight()
{
    m_inFlight = true;
}
 
void
WifiMpdu::ResetInFlight()
{
    m_inFlight = false;
}
 
bool
WifiMpdu::IsInFlight() const
{
    return m_inFlight;
}
 
WifiMpdu::DeaggregatedMsdusCI
WifiMpdu::begin() const
{
    return m_msduList.cbegin();
}
 
WifiMpdu::DeaggregatedMsdusCI
WifiMpdu::end() const
{
    return m_msduList.cend();
}
 
void
WifiMpdu::Print(std::ostream& os) const
{
    os << m_header.GetTypeString() << ", payloadSize=" << GetPacketSize()
       << ", to=" << m_header.GetAddr1() << ", seqN=" << m_header.GetSequenceNumber()
       << ", duration/ID=" << m_header.GetDuration();
    if (m_header.IsQosData())
    {
        os << ", tid=" << +m_header.GetQosTid();
        if (m_header.IsQosNoAck())
        {
            os << ", ack=NoAck";
        }
        else if (m_header.IsQosAck())
        {
            os << ", ack=NormalAck";
        }
        else if (m_header.IsQosBlockAck())
        {
            os << ", ack=BlockAck";
        }
    }
    os << ", queued=" << IsQueued();
    if (IsQueued())
    {
        os << ", residualLifetime=" << (GetExpiryTime() - Simulator::Now()).As(Time::US)
           << ", inflight=" << IsInFlight();
    }
    os << ", packet=" << m_packet;
}
 
std::ostream&
operator<<(std::ostream& os, const WifiMpdu& item)
{
    item.Print(os);
    return os;
}
 
} // namespace ns3