tcp-slow-start-test.cc

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/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
/*
 * 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 "ns3/log.h"
#include "ns3/test.h"
#include "ns3/simple-channel.h"
#include "ns3/node.h"
#include "ns3/config.h"
#include "ns3/tcp-westwood.h"
#include "ns3/tcp-header.h"
#include "tcp-general-test.h"

using namespace ns3;

NS_LOG_COMPONENT_DEFINE ("TcpSlowStartTest");

class
TcpSlowStartNormalTest : public TcpGeneralTest
{
public:
  TcpSlowStartNormalTest (uint32_t segmentSize, uint32_t packetSize,
                          uint32_t initSsTh, uint32_t packets, TypeId& congControl,
                          const std::string &desc);

protected:
  virtual void CWndTrace (uint32_t oldValue, uint32_t newValue);
  virtual void Tx (const Ptr<const Packet> p, const TcpHeader &h, SocketWho who);
  virtual void Rx (const Ptr<const Packet> p, const TcpHeader &h, SocketWho who);
  void QueueDrop (SocketWho who);
  void PhyDrop (SocketWho who);

  virtual void ConfigureEnvironment ();
  virtual void ConfigureProperties ();

  uint32_t m_ackedBytes;        
  uint32_t m_sentBytes;         
  uint32_t m_totalAckedBytes;   
  uint32_t m_allowedIncrease;   

  bool   m_initial; 

private:
  uint32_t m_segmentSize;   
  uint32_t m_packetSize;    
  uint32_t m_packets;       
};

TcpSlowStartNormalTest::TcpSlowStartNormalTest (uint32_t segmentSize,
                                                uint32_t packetSize,
                                                uint32_t initSsTh,
                                                uint32_t packets,
                                                TypeId &typeId,
                                                const std::string &desc)
  : TcpGeneralTest (desc),
    m_ackedBytes (0),
    m_sentBytes (0),
    m_totalAckedBytes (0),
    m_allowedIncrease (0),
    m_initial (true),
    m_segmentSize (segmentSize),
    m_packetSize (packetSize),
    m_packets (packets)
{
  m_congControlTypeId = typeId;
}

void
TcpSlowStartNormalTest::ConfigureEnvironment ()
{
  TcpGeneralTest::ConfigureEnvironment ();
  SetAppPktCount (m_packets);
  SetAppPktSize (m_packetSize);
}

void
TcpSlowStartNormalTest::ConfigureProperties ()
{
  TcpGeneralTest::ConfigureProperties ();
  SetInitialSsThresh (SENDER, 400000);
  SetSegmentSize (SENDER, m_segmentSize);
  SetSegmentSize (RECEIVER, m_segmentSize);
}

void
TcpSlowStartNormalTest::QueueDrop (SocketWho who)
{
  NS_FATAL_ERROR ("Drop on the queue; cannot validate slow start");
}

void
TcpSlowStartNormalTest::PhyDrop (SocketWho who)
{
  NS_FATAL_ERROR ("Drop on the phy: cannot validate slow start");
}

void
TcpSlowStartNormalTest::CWndTrace (uint32_t oldValue, uint32_t newValue)
{
  uint32_t segSize = GetSegSize (TcpGeneralTest::SENDER);
  uint32_t increase = newValue - oldValue;

  if (m_initial)
    {
      m_initial = false;
      NS_LOG_INFO ("Ignored update to " << newValue <<
                   " with a segsize of " << segSize);
      return;
    }

  // The increase in RFC should be <= of segSize. In ns-3 we force = segSize
  NS_TEST_ASSERT_MSG_EQ (increase, segSize, "Increase different than segsize");
  NS_TEST_ASSERT_MSG_LT_OR_EQ (newValue, GetInitialSsThresh (SENDER), "cWnd increased over ssth");

  NS_LOG_INFO ("Incremented cWnd by " << segSize << " bytes in Slow Start " <<
               "achieving a value of " << newValue);

  NS_TEST_ASSERT_MSG_GT_OR_EQ (m_allowedIncrease, 1, "Increase not allowed");
  m_allowedIncrease--;
}

void
TcpSlowStartNormalTest::Tx (const Ptr<const Packet> p, const TcpHeader &h, SocketWho who)
{
  NS_LOG_FUNCTION (this << p << h << who);

  if (who == SENDER && Simulator::Now ().GetSeconds () > 5.0)
    {
      m_sentBytes += GetSegSize (TcpGeneralTest::SENDER);
    }
}

void
TcpSlowStartNormalTest::Rx (const Ptr<const Packet> p, const TcpHeader &h, SocketWho who)
{
  NS_LOG_FUNCTION (this << p << h << who);

  if (who == SENDER && Simulator::Now ().GetSeconds () > 5.0)
    {
      uint32_t acked = h.GetAckNumber ().GetValue () - m_totalAckedBytes - 1;
      m_totalAckedBytes += acked;
      m_ackedBytes += acked;

      NS_LOG_INFO ("Ack of " << acked << " bytes, acked this round=" << m_ackedBytes);

      if (m_ackedBytes >= GetSegSize (SENDER))
        {
          NS_LOG_INFO ("FULL ACK achieved, bytes=" << m_ackedBytes);
          m_allowedIncrease += 1;
          m_ackedBytes -= GetSegSize (SENDER);
        }

      while (m_ackedBytes >= GetSegSize (SENDER))
        {
          m_ackedBytes -= GetSegSize (SENDER);
        }
    }
}

class
TcpSlowStartAttackerTest : public TcpSlowStartNormalTest
{
public:
  TcpSlowStartAttackerTest (uint32_t segmentSize, uint32_t packetSize,
                            uint32_t initSsTh, uint32_t packets, TypeId& congControl,
                            const std::string &desc);

protected:
  virtual Ptr<TcpSocketMsgBase> CreateReceiverSocket (Ptr<Node> node);
};

TcpSlowStartAttackerTest::TcpSlowStartAttackerTest (uint32_t segmentSize,
                                                    uint32_t packetSize,
                                                    uint32_t initSsTh,
                                                    uint32_t packets,
                                                    TypeId &typeId, const std::string &msg)
  : TcpSlowStartNormalTest (segmentSize, packetSize, initSsTh, packets, typeId, msg)
{

}

Ptr<TcpSocketMsgBase>
TcpSlowStartAttackerTest::CreateReceiverSocket (Ptr<Node> node)
{
  Ptr<TcpSocketSmallAcks> socket = DynamicCast<TcpSocketSmallAcks> (
      CreateSocket (node,
                    TcpSocketSmallAcks::GetTypeId (),
                    m_congControlTypeId));
  socket->SetBytesToAck (125);

  return socket;
}


class TcpSlowStartTestSuite : public TestSuite
{
public:
  TcpSlowStartTestSuite () : TestSuite ("tcp-slow-start-test", UNIT)
  {
    // This test have less packets to transmit than SsTh
    std::list<TypeId> types;
    types.insert (types.begin (), TcpNewReno::GetTypeId ());
    types.insert (types.begin (), TcpWestwood::GetTypeId ());

    for (std::list<TypeId>::iterator it = types.begin (); it != types.end (); ++it)
      {
        AddTestCase (new TcpSlowStartNormalTest (500, 500, 10000, 10, (*it),
                                                 "slow start 500 byte, " + (*it).GetName ()),
                     TestCase::QUICK);
        AddTestCase (new TcpSlowStartNormalTest (1000, 1000, 10000, 9, (*it),
                                                 "slow start 1000 byte, " + (*it).GetName ()),
                     TestCase::QUICK);
        AddTestCase (new TcpSlowStartNormalTest (500, 250, 10000, 10, (*it),
                                                 "slow start small packets, " + (*it).GetName ()),
                     TestCase::QUICK);
        AddTestCase (new TcpSlowStartAttackerTest (500, 500, 10000, 10, (*it),
                                                   "slow start ack attacker, 500 byte, " + (*it).GetName ()),
                     TestCase::QUICK);
        AddTestCase (new TcpSlowStartAttackerTest (1000, 1000, 10000, 9, (*it),
                                                   "slow start ack attacker, 1000 byte, " + (*it).GetName ()),
                     TestCase::QUICK);
      }
  }
};

static TcpSlowStartTestSuite g_tcpSlowStartTestSuite;