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

/*

 * 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

//

//  +----------+                                                                  

//  | external |                                                                  

//  |  Linux   |                                                                  

//  |   Host   |                                                                  

//  |          |

//  | "mytap"  |                                                                  

//  +----------+                                                                  

//       |           n0                n3                n4

//       |       +--------+     +------------+     +------------+

//       +-------|  tap   |     |            |     |            |

//               | bridge | ... |            |     |            |

//               +--------+     +------------+     +------------+

//               |  Wifi  |     | Wifi | P2P |-----| P2P | CSMA |

//               +--------+     +------+-----+     +-----+------+

//                   |              |           ^           |

//                 ((*))          ((*))         |           |         

//                                          P2P 10.1.2      |         

//                 ((*))          ((*))                     |    n5  n6   n7

//                   |              |                       |     |   |    |

//                  n1             n2                       ================

//                     Wifi 10.1.1                           CSMA LAN 10.1.3

//

// The Wifi device on node zero is:  10.1.1.1

// The Wifi device on node one is:   10.1.1.2

// The Wifi device on node two is:   10.1.1.3

// The Wifi device on node three is: 10.1.1.4

// The P2P device on node three is:  10.1.2.1

// The P2P device on node four is:   10.1.2.2

// The CSMA device on node four is:  10.1.3.1

// The CSMA device on node five is:  10.1.3.2

// The CSMA device on node six is:   10.1.3.3

// The CSMA device on node seven is: 10.1.3.4

//

// Some simple things to do:

//

// 1) Ping one of the simulated nodes on the left side of the topology.

//

//    ./waf --run tap-wifi-dumbbell&

//    ping 10.1.1.3

//

// 2) Configure a route in the linux host and ping once of the nodes on the 

//    right, across the point-to-point link.  You will see relatively large

//    delays due to CBR background traffic on the point-to-point (see next

//    item).

//

//    ./waf --run tap-wifi-dumbbell&

//    sudo route add -net 10.1.3.0 netmask 255.255.255.0 dev thetap gw 10.1.1.2

//    ping 10.1.3.4

//

//    Take a look at the pcap traces and note that the timing reflects the 

//    addition of the significant delay and low bandwidth configured on the 

//    point-to-point link along with the high traffic.

//

// 3) Fiddle with the background CBR traffic across the point-to-point 

//    link and watch the ping timing change.  The OnOffApplication "DataRate"

//    attribute defaults to 500kb/s and the "PacketSize" Attribute defaults

//    to 512.  The point-to-point "DataRate" is set to 512kb/s in the script,

//    so in the default case, the link is pretty full.  This should be 

//    reflected in large delays seen by ping.  You can crank down the CBR 

//    traffic data rate and watch the ping timing change dramatically.

//

//    ./waf --run "tap-wifi-dumbbell --ns3::OnOffApplication::DataRate=100kb/s"&

//    sudo route add -net 10.1.3.0 netmask 255.255.255.0 dev thetap gw 10.1.1.2

//    ping 10.1.3.4

//

// 4) Try to run this in UseLocal mode.  This allows you to provide an existing

//    pre-configured tap device to the simulation.  The IP address and MAC 

//    address in this mode do not have to match those of the ns-3 device.

//

//    sudo tunctl -t mytap

//    sudo ifconfig mytap hw ether 08:00:2e:00:00:01

//    sudo ifconfig mytap 10.1.1.1 netmask 255.255.255.0 up

//    ./waf --run "tap-wifi-dumbbell --mode=UseLocal --tapName=mytap"&

//    ping 10.1.1.3

//

// 5) Try to run this in UseBridge mode.  This allows you to bridge an ns-3

//    simulation to an existing pre-configured bridge.  This uses tap devices

//    just for illustration, you can create your own bridge if you want.

//

//    sudo tunctl -t mytap1

//    sudo ifconfig mytap1 0.0.0.0 promisc up

//    sudo tunctl -t mytap2

//    sudo ifconfig mytap2 0.0.0.0 promisc up

//    sudo brctl addbr mybridge

//    sudo brctl addif mybridge mytap1

//    sudo brctl addif mybridge mytap2

//    sudo ifconfig mybridge 10.1.1.5 netmask 255.255.255.0 up

//    ./waf --run "tap-wifi-dumbbell --mode=UseBridge --tapName=mytap2"&

//    ping 10.1.1.3

#include <iostream>

#include <fstream>

#include "ns3/simulator-module.h"

#include "ns3/node-module.h"

#include "ns3/core-module.h"

#include "ns3/wifi-module.h"

#include "ns3/helper-module.h"

#include "ns3/global-routing-module.h"

using namespace ns3;

NS_LOG_COMPONENT_DEFINE ("TapDumbbellExample");

int 

main (int argc, char *argv[])

{

  std::string mode = "ConfigureLocal";

  std::string tapName = "thetap";

  CommandLine cmd;

  cmd.AddValue("mode", "Mode setting of TapBridge", mode);

  cmd.AddValue("tapName", "Name of the OS tap device", tapName);

  cmd.Parse (argc, argv);

  GlobalValue::Bind ("SimulatorImplementationType", StringValue ("ns3::RealtimeSimulatorImpl"));

  Config::SetDefault ("ns3::Ipv4L3Protocol::CalcChecksum", BooleanValue (true)); 

  Config::SetDefault ("ns3::Icmpv4L4Protocol::CalcChecksum", BooleanValue (true)); 

  Config::SetDefault ("ns3::TcpL4Protocol::CalcChecksum", BooleanValue (true)); 

  Config::SetDefault ("ns3::UdpL4Protocol::CalcChecksum", BooleanValue (true)); 

  //

  // The topology has a Wifi network of four nodes on the left side.  We'll make

  // node zero the AP and have the other three will be the STAs.

  //

  NodeContainer nodesLeft;

  nodesLeft.Create (4);

  YansWifiPhyHelper wifiPhy = YansWifiPhyHelper::Default ();

  YansWifiChannelHelper wifiChannel = YansWifiChannelHelper::Default ();

  wifiPhy.SetChannel (wifiChannel.Create ());

  Ssid ssid = Ssid ("left");

  WifiHelper wifi = WifiHelper::Default ();

  wifi.SetRemoteStationManager ("ns3::ArfWifiManager");

  MobilityHelper mobility;

  mobility.Install (nodesLeft);

  InternetStackHelper internetLeft;

  internetLeft.Install (nodesLeft);

  Ipv4AddressHelper ipv4Left;

  ipv4Left.SetBase ("10.1.1.0", "255.255.255.0");

  Ipv4InterfaceContainer interfacesLeft = ipv4Left.Assign (devicesLeft);

  TapBridgeHelper tapBridge (interfacesLeft.GetAddress (1));

  tapBridge.SetAttribute ("Mode", StringValue (mode));

  tapBridge.SetAttribute ("DeviceName", StringValue (tapName));

  tapBridge.Install (nodesLeft.Get (0), devicesLeft.Get (0));

  //

  // Now, create the right side.

  //

  NodeContainer nodesRight;

  nodesRight.Create (4);

  CsmaHelper csmaRight;

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

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

  NetDeviceContainer devicesRight = csmaRight.Install (nodesRight);

  InternetStackHelper internetRight;

  internetRight.Install (nodesRight);

  Ipv4AddressHelper ipv4Right;

  ipv4Right.SetBase ("10.1.3.0", "255.255.255.0");

  Ipv4InterfaceContainer interfacesRight = ipv4Right.Assign (devicesRight);

  //

  // Stick in the point-to-point line between the sides.

  //

  PointToPointHelper p2p;

  p2p.SetDeviceAttribute ("DataRate", StringValue ("512kbps"));

  p2p.SetChannelAttribute ("Delay", StringValue ("10ms"));

  NodeContainer nodes = NodeContainer (nodesLeft.Get(3), nodesRight.Get (0));

  NetDeviceContainer devices = p2p.Install (nodes);

  Ipv4AddressHelper ipv4;

  ipv4.SetBase ("10.1.2.0", "255.255.255.192");

  Ipv4InterfaceContainer interfaces = ipv4.Assign (devices);

  //

  // Simulate some CBR traffic over the point-to-point link

  //

  uint16_t port = 9;   // Discard port (RFC 863)

  OnOffHelper onoff ("ns3::UdpSocketFactory", InetSocketAddress (interfaces.GetAddress (1), port));

  onoff.SetAttribute ("OnTime", RandomVariableValue (ConstantVariable (1)));

  onoff.SetAttribute ("OffTime", RandomVariableValue (ConstantVariable (0)));

  ApplicationContainer apps = onoff.Install (nodesLeft.Get (3));

  apps.Start (Seconds (1.0));

  // Create a packet sink to receive these packets

  PacketSinkHelper sink ("ns3::UdpSocketFactory", InetSocketAddress (Ipv4Address::GetAny (), port));

  apps = sink.Install (nodesRight.Get (0));

  apps.Start (Seconds (1.0));

  CsmaHelper::EnablePcapAll ("tap-dumbbell", false);

  GlobalRouteManager::PopulateRoutingTables ();

  Simulator::Stop (Seconds (60.));

  Simulator::Run ();

  Simulator::Destroy ();

}