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

/*

 * Copyright (c) 2009 Strasbourg University

 *

 * 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

 *

 */

// Network topology

//

//             STA2

//              |

//              |

//   R1         R2

//   |          |

//   |          |

//   ------------

//           |

//           |

//          STA 1

//

// - Initial configuration :

//         - STA1 default route : R1

//         - R1 static route to STA2 : R2

//         - STA2 default route : R2

// - STA1 send Echo Request to STA2 using its default route to R1

// - R1 receive Echo Request from STA1, and forward it to R2

// - R1 send an ICMPv6 Redirection to STA1 with Target STA2 and Destination R2

// - Next Echo Request from STA1 to STA2 are directly sent to R2

#include <fstream>

#include "ns3/core-module.h"

#include "ns3/simulator-module.h"

#include "ns3/helper-module.h"

#include "ns3/ipv6-routing-table-entry.h"

using namespace ns3;

NS_LOG_COMPONENT_DEFINE ("Icmpv6RedirectExample");

/**

 * \class StackHelper

 * \brief Helper to set or get some IPv6 information about nodes.

 */

class StackHelper

{

  public:

    /**

     * \brief Print the routing table.

     * \param n the node

     */

    inline void PrintRoutingTable (Ptr<Node>& n)

    {

      Ptr<Ipv6StaticRouting> routing = 0;

      Ipv6StaticRoutingHelper routingHelper;

      Ptr<Ipv6> ipv6 = n->GetObject<Ipv6> ();

      uint32_t nbRoutes = 0;

      Ipv6RoutingTableEntry route;

      routing = routingHelper.GetStaticRouting (ipv6);

      std::cout << "Routing table of " << n << " : " << std::endl;

      std::cout << "Destination\t\t\t\t" << "Gateway\t\t\t\t\t" << "Interface\t" << "Prefix to use" << std::endl;

      nbRoutes = routing->GetNRoutes ();

      for(uint32_t i = 0 ; i < nbRoutes ; i++)

      {

        route = routing->GetRoute (i);

        std::cout << route.GetDest () << "\t"

          << route.GetGateway () << "\t"

          << route.GetInterface () << "\t" 

          << route.GetPrefixToUse () << "\t"

          << std::endl;

      }

    }

    /**

     * \brief Add an host route.

     * \param n node 

     * \param dst destination address

     * \param nextHop next hop for destination

     * \param interface output interface

     */

    inline void AddHostRouteTo (Ptr<Node>& n, Ipv6Address dst, Ipv6Address nextHop, uint32_t interface)

    {

      Ptr<Ipv6StaticRouting> routing = 0;

      Ipv6StaticRoutingHelper routingHelper;

      Ptr<Ipv6> ipv6 = n->GetObject<Ipv6> ();

      routing = routingHelper.GetStaticRouting (ipv6);

      routing->AddHostRouteTo (dst, nextHop, interface);

    }

};

int main (int argc, char **argv)

{

#if 0 

  LogComponentEnable ("Icmpv6RedirectExample", LOG_LEVEL_INFO);

  LogComponentEnable ("Icmpv6L4Protocol", LOG_LEVEL_INFO);

  LogComponentEnable("Ipv6L3Protocol", LOG_LEVEL_ALL);

  LogComponentEnable("Ipv6StaticRouting", LOG_LEVEL_ALL);

  LogComponentEnable("Ipv6Interface", LOG_LEVEL_ALL);

  LogComponentEnable("Icmpv6L4Protocol", LOG_LEVEL_ALL);

  LogComponentEnable("NdiscCache", LOG_LEVEL_ALL);

#endif

  CommandLine cmd;

  cmd.Parse (argc, argv);

  NS_LOG_INFO ("Create nodes.");

  Ptr<Node> sta1 = CreateObject<Node> ();

  Ptr<Node> r1 = CreateObject<Node> ();

  Ptr<Node> r2 = CreateObject<Node> ();

  Ptr<Node> sta2 = CreateObject<Node> ();

  NodeContainer net1(sta1, r1, r2);

  NodeContainer net2(r2, sta2);

  NodeContainer all(sta1, r1, r2, sta2);

  StackHelper stackHelper;

  InternetStackHelper internetv6;

  internetv6.Install (all);

  NS_LOG_INFO ("Create channels.");

  CsmaHelper csma;

  csma.SetChannelAttribute ("DataRate", DataRateValue(5000000));

  csma.SetChannelAttribute ("Delay", TimeValue(MilliSeconds (2)));

  NetDeviceContainer ndc1 = csma.Install (net1); 

  NetDeviceContainer ndc2 = csma.Install (net2);

  NS_LOG_INFO ("Assign IPv6 Addresses.");

  Ipv6AddressHelper ipv6;

  ipv6.NewNetwork (Ipv6Address ("2001:1::"), 64);

  Ipv6InterfaceContainer iic1 = ipv6.Assign (ndc1);

  iic1.SetRouter (2, true);

  iic1.SetRouter (1, true);

  ipv6.NewNetwork (Ipv6Address ("2001:2::"), 64);

  Ipv6InterfaceContainer iic2 = ipv6.Assign (ndc2);

  iic2.SetRouter (0, true);

  stackHelper.AddHostRouteTo (r1, iic2.GetAddress (1, 1), iic1.GetAddress (2, 1), iic1.GetInterfaceIndex (1));

  Simulator::Schedule(Seconds(0.0), &StackHelper::PrintRoutingTable, &stackHelper, r1);

  Simulator::Schedule(Seconds(3.0), &StackHelper::PrintRoutingTable, &stackHelper, sta1);

  NS_LOG_INFO ("Create Applications.");

  uint32_t packetSize = 1024;

  uint32_t maxPacketCount = 5;

  Time interPacketInterval = Seconds (1.);

  Ping6Helper ping6;

  ping6.SetLocal (iic1.GetAddress(0, 1));

  ping6.SetRemote (iic2.GetAddress(1, 1));

  ping6.SetAttribute ("MaxPackets", UintegerValue (maxPacketCount));

  ping6.SetAttribute ("Interval", TimeValue(interPacketInterval));

  ping6.SetAttribute ("PacketSize", UintegerValue (packetSize));

  ApplicationContainer apps = ping6.Install (sta1);

  apps.Start (Seconds (2.0));

  apps.Stop (Seconds (10.0));

  std::ofstream ascii;

  ascii.open ("icmpv6-redirect.tr");

  CsmaHelper::EnablePcapAll ("icmpv6-redirect", true);

  CsmaHelper::EnableAsciiAll (ascii);

  /* Now, do the actual simulation. */

  NS_LOG_INFO ("Run Simulation.");

  Simulator::Run ();

  Simulator::Destroy ();

  NS_LOG_INFO ("Done.");

}