/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */

/*

 * Copyright (c) 2013 ResiliNets, ITTC, University of Kansas

 *

 * 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: Justin P. Rohrer, Truc Anh N. Nguyen <annguyen@ittc.ku.edu>, Siddharth Gangadhar <siddharth@ittc.ku.edu>

 *

 * James P.G. Sterbenz <jpgs@ittc.ku.edu>, director

 * ResiliNets Research Group  http://wiki.ittc.ku.edu/resilinets

 * 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.

 *

 * “TCP Westwood(+) Protocol Implementation in ns-3”

 * Siddharth Gangadhar, Trúc Anh Ngọc Nguyễn , Greeshma Umapathi, and James P.G. Sterbenz,

 * ICST SIMUTools Workshop on ns-3 (WNS3), Cannes, France, March 2013

 */

#include <iostream>

#include <fstream>

#include <string>

#include "ns3/core-module.h"

#include "ns3/network-module.h"

#include "ns3/internet-module.h"

#include "ns3/point-to-point-module.h"

#include "ns3/applications-module.h"

#include "ns3/error-model.h"

#include "ns3/tcp-header.h"

#include "ns3/udp-header.h"

#include "ns3/enum.h"

#include "ns3/event-id.h"

#include "ns3/flow-monitor-helper.h"

#include "ns3/ipv4-global-routing-helper.h"

using namespace ns3;

NS_LOG_COMPONENT_DEFINE ("TcpVariantsComparison");

bool firstCwnd = true;

bool firstSshThr = true;

Ptr<OutputStreamWrapper> cWndStream;

Ptr<OutputStreamWrapper> ssThreshStream;

uint32_t cWndValue;

uint32_t ssThreshValue;

static void

CwndTracer (uint32_t oldval, uint32_t newval)

{

  if (firstCwnd)

    {

      *cWndStream->GetStream () << "0.0 " << oldval << std::endl;

      firstCwnd = false;

    }

  *cWndStream->GetStream () << Simulator::Now ().GetSeconds () << " " << newval << std::endl;

  cWndValue = newval;

  if (!firstSshThr)

    {

      *ssThreshStream->GetStream () << Simulator::Now ().GetSeconds () << " " << ssThreshValue << std::endl;

    }

}

static void

SsThreshTracer (uint32_t oldval, uint32_t newval)

{

  if (firstSshThr)

    {

      *ssThreshStream->GetStream () << "0.0 " << oldval << std::endl;

      firstSshThr = false;

    }

  *ssThreshStream->GetStream () << Simulator::Now ().GetSeconds () << " " << newval << std::endl;

  ssThreshValue = newval;

  if (!firstCwnd)

    {

      *cWndStream->GetStream () << Simulator::Now ().GetSeconds () << " " << cWndValue << std::endl;

    }

}

static void

TraceCwnd (std::string cwnd_tr_file_name)

{

  AsciiTraceHelper ascii;

  cWndStream = ascii.CreateFileStream (cwnd_tr_file_name.c_str ());

  Config::ConnectWithoutContext ("/NodeList/1/$ns3::TcpL4Protocol/SocketList/0/CongestionWindow", MakeCallback (&CwndTracer));

}

static void

TraceSsThresh (std::string ssthresh_tr_file_name)

{

  AsciiTraceHelper ascii;

  ssThreshStream = ascii.CreateFileStream (ssthresh_tr_file_name.c_str ());

  Config::ConnectWithoutContext ("/NodeList/1/$ns3::TcpL4Protocol/SocketList/0/SlowStartThreshold",MakeCallback (&SsThreshTracer));

}

int main (int argc, char *argv[])

{

  std::string transport_prot = "TcpWestwood";

  double error_p = 0.0;

  std::string bandwidth = "2Mbps";

  std::string access_bandwidth = "10Mbps";

  std::string access_delay = "45ms";

  bool tracing = false;

  std::string tr_file_name = "";

  std::string cwnd_tr_file_name = "";

  std::string ssthresh_tr_file_name = "";

  double data_mbytes = 0;

  uint32_t mtu_bytes = 400;

  uint16_t num_flows = 1;

  float duration = 100;

  uint32_t run = 0;

  bool flow_monitor = true;

  CommandLine cmd;

  cmd.AddValue ("transport_prot", "Transport protocol to use: TcpTahoe, TcpReno, TcpNewReno, TcpWestwood, TcpWestwoodPlus ", transport_prot);

  cmd.AddValue ("error_p", "Packet error rate", error_p);

  cmd.AddValue ("bandwidth", "Bottleneck bandwidth", bandwidth);

  cmd.AddValue ("access_bandwidth", "Access link bandwidth", access_bandwidth);

  cmd.AddValue ("delay", "Access link delay", access_delay);

  cmd.AddValue ("tracing", "Flag to enable/disable tracing", tracing);

  cmd.AddValue ("tr_name", "Name of output trace file", tr_file_name);

  cmd.AddValue ("cwnd_tr_name", "Name of output trace file", cwnd_tr_file_name);

  cmd.AddValue ("ssthresh_tr_name", "Name of output trace file", ssthresh_tr_file_name);

  cmd.AddValue ("data", "Number of Megabytes of data to transmit", data_mbytes);

  cmd.AddValue ("mtu", "Size of IP packets to send in bytes", mtu_bytes);

  cmd.AddValue ("num_flows", "Number of flows", num_flows);

  cmd.AddValue ("duration", "Time to allow flows to run in seconds", duration);

  cmd.AddValue ("run", "Run index (for setting repeatable seeds)", run);

  cmd.AddValue ("flow_monitor", "Enable flow monitor", flow_monitor);

  cmd.Parse (argc, argv);

  SeedManager::SetSeed (1);

  SeedManager::SetRun (run);

  // User may find it convenient to enable logging

  //LogComponentEnable("TcpVariantsComparison", LOG_LEVEL_ALL);

  //LogComponentEnable("BulkSendApplication", LOG_LEVEL_INFO);

  //LogComponentEnable("DropTailQueue", LOG_LEVEL_ALL);

  // Calculate the ADU size

  Header* temp_header = new Ipv4Header ();

  uint32_t ip_header = temp_header->GetSerializedSize ();

  NS_LOG_LOGIC ("IP Header size is: " << ip_header);

  delete temp_header;

  temp_header = new TcpHeader ();

  uint32_t tcp_header = temp_header->GetSerializedSize ();

  NS_LOG_LOGIC ("TCP Header size is: " << tcp_header);

  delete temp_header;

  uint32_t tcp_adu_size = mtu_bytes - (ip_header + tcp_header);

  NS_LOG_LOGIC ("TCP ADU size is: " << tcp_adu_size);

  // Set the simulation start and stop time

  float start_time = 0.1;

  float stop_time = start_time + duration;

  // Select TCP variant

  if (transport_prot.compare ("TcpTahoe") == 0)

    {

      Config::SetDefault ("ns3::TcpL4Protocol::SocketType", TypeIdValue (TcpTahoe::GetTypeId ()));

    }

  else if (transport_prot.compare ("TcpReno") == 0)

    {

      Config::SetDefault ("ns3::TcpL4Protocol::SocketType", TypeIdValue (TcpReno::GetTypeId ()));

    }

  else if (transport_prot.compare ("TcpNewReno") == 0)

    {

      Config::SetDefault ("ns3::TcpL4Protocol::SocketType", TypeIdValue (TcpNewReno::GetTypeId ()));

    }

  else if (transport_prot.compare ("TcpWestwood") == 0)

    { // the default protocol type in ns3::TcpWestwood is WESTWOOD

      Config::SetDefault ("ns3::TcpL4Protocol::SocketType", TypeIdValue (TcpWestwood::GetTypeId ()));

      Config::SetDefault ("ns3::TcpWestwood::FilterType", EnumValue (TcpWestwood::TUSTIN));

    }

  else if (transport_prot.compare ("TcpWestwoodPlus") == 0)

    {

      Config::SetDefault ("ns3::TcpL4Protocol::SocketType", TypeIdValue (TcpWestwood::GetTypeId ()));

      Config::SetDefault ("ns3::TcpWestwood::ProtocolType", EnumValue (TcpWestwood::WESTWOODPLUS));

      Config::SetDefault ("ns3::TcpWestwood::FilterType", EnumValue (TcpWestwood::TUSTIN));

    }

  else

    {

      NS_LOG_DEBUG ("Invalid TCP version");

      exit (1);

    }

  // Create gateways, sources, and sinks

  NodeContainer gateways;

  gateways.Create (1);

  NodeContainer sources;

  sources.Create (num_flows);

  NodeContainer sinks;

  sinks.Create (num_flows);

  // Configure the error model

  // Here we use RateErrorModel with packet error rate

  Ptr<UniformRandomVariable> uv = CreateObject<UniformRandomVariable> ();

  uv->SetStream (50);

  RateErrorModel error_model;

  error_model.SetRandomVariable (uv);

  error_model.SetUnit (RateErrorModel::ERROR_UNIT_PACKET);

  error_model.SetRate (error_p);

  PointToPointHelper UnReLink;

  UnReLink.SetDeviceAttribute ("DataRate", StringValue (bandwidth));

  UnReLink.SetChannelAttribute ("Delay", StringValue ("0.01ms"));

  UnReLink.SetDeviceAttribute ("ReceiveErrorModel", PointerValue (&error_model));

  InternetStackHelper stack;

  stack.InstallAll ();

  Ipv4AddressHelper address;

  address.SetBase ("10.0.0.0", "255.255.255.0");

  // Configure the sources and sinks net devices

  // and the channels between the sources/sinks and the gateways

  PointToPointHelper LocalLink;

  LocalLink.SetDeviceAttribute ("DataRate", StringValue (access_bandwidth));

  LocalLink.SetChannelAttribute ("Delay", StringValue (access_delay));

  Ipv4InterfaceContainer sink_interfaces;

  for (int i = 0; i < num_flows; i++)

    {

      NetDeviceContainer devices;

      devices = LocalLink.Install (sources.Get (i), gateways.Get (0));

      address.NewNetwork ();

      Ipv4InterfaceContainer interfaces = address.Assign (devices);

      devices = UnReLink.Install (gateways.Get (0), sinks.Get (i));

      address.NewNetwork ();

      interfaces = address.Assign (devices);

      sink_interfaces.Add (interfaces.Get (1));

    }

  NS_LOG_INFO ("Initialize Global Routing.");

  Ipv4GlobalRoutingHelper::PopulateRoutingTables ();

  uint16_t port = 50000;

  Address sinkLocalAddress (InetSocketAddress (Ipv4Address::GetAny (), port));

  PacketSinkHelper sinkHelper ("ns3::TcpSocketFactory", sinkLocalAddress);

  for (uint16_t i = 0; i < sources.GetN (); i++)

    {

      AddressValue remoteAddress (InetSocketAddress (sink_interfaces.GetAddress (i, 0), port));

      if (transport_prot.compare ("TcpTahoe") == 0

          || transport_prot.compare ("TcpReno") == 0

          || transport_prot.compare ("TcpNewReno") == 0

          || transport_prot.compare ("TcpWestwood") == 0

          || transport_prot.compare ("TcpWestwoodPlus") == 0)

        {

          Config::SetDefault ("ns3::TcpSocket::SegmentSize", UintegerValue (tcp_adu_size));

          BulkSendHelper ftp ("ns3::TcpSocketFactory", Address ());

          ftp.SetAttribute ("Remote", remoteAddress);

          ftp.SetAttribute ("SendSize", UintegerValue (tcp_adu_size));

          ftp.SetAttribute ("MaxBytes", UintegerValue (int(data_mbytes * 1000000)));

          ApplicationContainer sourceApp = ftp.Install (sources.Get (i));

          sourceApp.Start (Seconds (start_time * i));

          sourceApp.Stop (Seconds (stop_time - 3));

          sinkHelper.SetAttribute ("Protocol", TypeIdValue (TcpSocketFactory::GetTypeId ()));

          ApplicationContainer sinkApp = sinkHelper.Install (sinks);

          sinkApp.Start (Seconds (start_time * i));

          sinkApp.Stop (Seconds (stop_time));

        }

      else

        {

          NS_LOG_DEBUG ("Invalid transport protocol " << transport_prot << " specified");

          exit (1);

        }

    }

  // Set up tracing if enabled

  if (tracing)

    {

      if (tr_file_name.compare ("") != 0)

        {

          std::ofstream ascii;

          Ptr<OutputStreamWrapper> ascii_wrap;

          ascii.open (tr_file_name.c_str ());

          ascii_wrap = new OutputStreamWrapper (tr_file_name.c_str (), std::ios::out);

          stack.EnableAsciiIpv4All (ascii_wrap);

        }

      if (cwnd_tr_file_name.compare ("") != 0)

        {

          Simulator::Schedule (Seconds (0.00001), &TraceCwnd, cwnd_tr_file_name);

        }

      if (ssthresh_tr_file_name.compare ("") != 0)

        {

          Simulator::Schedule (Seconds (0.00001), &TraceSsThresh, ssthresh_tr_file_name);

        }

    }

  UnReLink.EnablePcapAll ("TcpVariantsComparison", true);

  LocalLink.EnablePcapAll ("TcpVariantsComparison", true);

  // Flow monitor

  FlowMonitorHelper flowHelper;

  if (flow_monitor)

    {

      flowHelper.InstallAll ();

    }

  Simulator::Stop (Seconds (stop_time));

  Simulator::Run ();

  if (flow_monitor)

    {

      flowHelper.SerializeToXmlFile ("TcpVariantsComparison.flowmonitor", true, true);

    }

  Simulator::Destroy ();

  return 0;

}