tcp-error-model.cc

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/*
 * Copyright (c) 2015 Natale Patriciello <natale.patriciello@gmail.com>
 *
 * 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
 *
 */
#include "tcp-error-model.h"
 
#include "ns3/ipv4-header.h"
#include "ns3/log.h"
#include "ns3/packet.h"
 
namespace ns3
{
 
NS_LOG_COMPONENT_DEFINE("TcpGeneralErrorModel");
 
NS_OBJECT_ENSURE_REGISTERED(TcpGeneralErrorModel);
 
TypeId
TcpGeneralErrorModel::GetTypeId()
{
    static TypeId tid = TypeId("ns3::TcpGeneralErrorModel").SetParent<ErrorModel>();
    return tid;
}
 
TcpGeneralErrorModel::TcpGeneralErrorModel()
{
    NS_LOG_FUNCTION(this);
}
 
bool
TcpGeneralErrorModel::DoCorrupt(Ptr<Packet> p)
{
    NS_LOG_FUNCTION(this << p);
 
    if (!IsEnabled())
    {
        return false;
    }
 
    Ipv4Header ipHeader;
    TcpHeader tcpHeader;
 
    p->RemoveHeader(ipHeader);
    p->RemoveHeader(tcpHeader);
 
    bool toDrop = ShouldDrop(ipHeader, tcpHeader, p->GetSize());
 
    if (toDrop && !m_dropCallback.IsNull())
    {
        m_dropCallback(ipHeader, tcpHeader, p);
    }
 
    p->AddHeader(tcpHeader);
    p->AddHeader(ipHeader);
 
    return toDrop;
}
 
NS_OBJECT_ENSURE_REGISTERED(TcpSeqErrorModel);
 
TypeId
TcpSeqErrorModel::GetTypeId()
{
    static TypeId tid = TypeId("ns3::TcpSeqErrorModel")
                            .SetParent<TcpGeneralErrorModel>()
                            .AddConstructor<TcpSeqErrorModel>();
    return tid;
}
 
bool
TcpSeqErrorModel::ShouldDrop(const Ipv4Header& ipHeader,
                             const TcpHeader& tcpHeader,
                             uint32_t packetSize)
{
    NS_LOG_FUNCTION(this << ipHeader << tcpHeader);
 
    bool toDrop = false;
 
    if (m_seqToKill.begin() != m_seqToKill.end() && packetSize != 0)
    {
        SequenceNumber32 toKill = m_seqToKill.front();
        NS_LOG_INFO("Analyzing seq=" << tcpHeader.GetSequenceNumber() << " killing=" << toKill);
        if (tcpHeader.GetSequenceNumber() == toKill)
        {
            NS_LOG_INFO("segment " << toKill << " dropped");
            toDrop = true;
            m_seqToKill.pop_front();
        }
    }
 
    return toDrop;
}
 
void
TcpSeqErrorModel::DoReset()
{
    m_seqToKill.erase(m_seqToKill.begin(), m_seqToKill.end());
}
 
NS_OBJECT_ENSURE_REGISTERED(TcpFlagErrorModel);
 
TypeId
TcpFlagErrorModel::GetTypeId()
{
    static TypeId tid = TypeId("ns3::TcpFlagErrorModel")
                            .SetParent<TcpGeneralErrorModel>()
                            .AddConstructor<TcpFlagErrorModel>();
    return tid;
}
 
TcpFlagErrorModel::TcpFlagErrorModel()
    : TcpGeneralErrorModel(),
      m_flagsToKill(TcpHeader::NONE),
      m_killNumber(0)
{
}
 
bool
TcpFlagErrorModel::ShouldDrop(const Ipv4Header& ipHeader,
                              const TcpHeader& tcpHeader,
                              uint32_t packetSize [[maybe_unused]])
{
    NS_LOG_FUNCTION(this << ipHeader << tcpHeader);
 
    bool toDrop = false;
 
    if ((tcpHeader.GetFlags() & m_flagsToKill) == m_flagsToKill)
    {
        if (m_killNumber > 0)
        {
            m_killNumber--;
            if (m_killNumber > 0)
            {
                toDrop = true;
            }
        }
        else if (m_killNumber < 0)
        {
            toDrop = true;
        }
    }
 
    return toDrop;
}
 
void
TcpFlagErrorModel::DoReset()
{
    m_flagsToKill = TcpHeader::NONE;
    m_killNumber = 0;
}
 
} // namespace ns3