/* -*- 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

//

//  n0

//     \ 5 Mb/s, 2ms

//      \          1.5Mb/s, 10ms

//       n2 ------------------------n3

//      /                          /

//     / 5 Mb/s, 2ms              /

//   n1--------------------------

//          1.5 Mb/s, 100ms

//

// this is a modification of simple-global-routing to allow for

// a single hop but higher-cost path between n1 and n3

// 

// - Tracing of queues and packet receptions to file "simple-rerouting.tr"

#include <iostream>

#include <fstream>

#include <string>

#include <cassert>

#include "ns3/log.h"

#include "ns3/command-line.h"

#include "ns3/default-value.h"

#include "ns3/ptr.h"

#include "ns3/random-variable.h"

#include "ns3/simulator.h"

#include "ns3/nstime.h"

#include "ns3/data-rate.h"

#include "ns3/ascii-trace.h"

#include "ns3/pcap-trace.h"

#include "ns3/internet-node.h"

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

#include "ns3/point-to-point-net-device.h"

#include "ns3/ipv4-address.h"

#include "ns3/ipv4.h"

#include "ns3/socket.h"

#include "ns3/inet-socket-address.h"

#include "ns3/ipv4-route.h"

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

#include "ns3/onoff-application.h"

#include "ns3/packet-sink.h"

#include "ns3/global-route-manager.h"

using namespace ns3;

NS_LOG_COMPONENT_DEFINE ("SimpleAlternateRoutingExample");

int 

main (int argc, char *argv[])

{

  // Users may find it convenient to turn on explicit debugging

  // for selected modules; the below lines suggest how to do this

#if 0 

  LogComponentEnable("GlobalRouteManager", LOG_LOGIC);

  LogComponentEnable("GlobalRouter", LOG_LOGIC);

  LogComponentEnable("Object", LOG_LEVEL_ALL);

  LogComponentEnable("Queue", LOG_LEVEL_ALL);

  LogComponentEnable("DropTailQueue", LOG_LEVEL_ALL);

  LogComponentEnable("Channel", LOG_LEVEL_ALL);

  LogComponentEnable("CsmaChannel", LOG_LEVEL_ALL);

  LogComponentEnable("NetDevice", LOG_LEVEL_ALL);

  LogComponentEnable("CsmaNetDevice", LOG_LEVEL_ALL);

  LogComponentEnable("Ipv4L3Protocol", LOG_LEVEL_ALL);

  LogComponentEnable("PacketSocket", LOG_LEVEL_ALL);

  LogComponentEnable("Socket", LOG_LEVEL_ALL);

  LogComponentEnable("UdpSocket", LOG_LEVEL_ALL);

  LogComponentEnable("UdpL4Protocol", LOG_LEVEL_ALL);

  LogComponentEnable("Ipv4L3Protocol", LOG_LEVEL_ALL);

  LogComponentEnable("Ipv4StaticRouting", LOG_LEVEL_ALL);

  LogComponentEnable("Ipv4Interface", LOG_LEVEL_ALL);

  LogComponentEnable("ArpIpv4Interface", LOG_LEVEL_ALL);

  LogComponentEnable("Ipv4LoopbackInterface", LOG_LEVEL_ALL);

  LogComponentEnable("OnOffApplication", LOG_LEVEL_ALL);

  LogComponentEnable("PacketSinkApplication", LOG_LEVEL_ALL);

  LogComponentEnable("UdpEchoClientApplication", LOG_LEVEL_ALL);

  LogComponentEnable("UdpEchoServerApplication", LOG_LEVEL_ALL);

#endif

  // Set up some default values for the simulation.  Use the 

  // DefaultValue::Bind () technique to tell the system what subclass of 

  // Queue to use, and what the queue limit is

  // The below Bind command tells the queue factory which class to

  // instantiate, when the queue factory is invoked in the topology code

  DefaultValue::Bind ("Queue", "DropTailQueue");

  DefaultValue::Bind ("OnOffApplicationPacketSize", "210");

  DefaultValue::Bind ("OnOffApplicationDataRate", "300b/s");

  // The below metric, if set to 3 or higher, will cause packets between

  // n1 and n3 to take the 2-hop route through n2

  // 

  // Additionally, we plumb this metric into the default value / command 

  // line argument system as well, for exemplary purposes.  This means 

  // that it can be resettable at the command-line to the program, 

  // rather than recompiling

  // e.g. waf --run "simple-alternate-routing --AlternateCost=5"

  uint16_t sampleMetric = 1;

  CommandLine::AddArgValue ("AlternateCost",

    "This metric is used in the example script between n3 and n1 ", 

    sampleMetric);

  // Allow the user to override any of the defaults and the above

  // DefaultValue::Bind ()s at run-time, via command-line arguments

  CommandLine::Parse (argc, argv);

  // Here, we will explicitly create four nodes.  In more sophisticated

  // topologies, we could configure a node factory.

  NS_LOG_INFO ("Create nodes.");

  Ptr<Node> n0 = Create<InternetNode> ();

  Ptr<Node> n1 = Create<InternetNode> (); 

  Ptr<Node> n2 = Create<InternetNode> (); 

  Ptr<Node> n3 = Create<InternetNode> ();

  // We create the channels first without any IP addressing information

  NS_LOG_INFO ("Create channels.");

  Ptr<PointToPointChannel> channel0 = 

    PointToPointTopology::AddPointToPointLink (

      n0, n2, DataRate (5000000), MilliSeconds (2));

  Ptr<PointToPointChannel> channel1 = 

    PointToPointTopology::AddPointToPointLink (

      n1, n2, DataRate (5000000), MilliSeconds (2));

  Ptr<PointToPointChannel> channel2 = 

    PointToPointTopology::AddPointToPointLink (

      n2, n3, DataRate (1500000), MilliSeconds (10));

  Ptr<PointToPointChannel> channel3 = 

    PointToPointTopology::AddPointToPointLink (

      n1, n3, DataRate (1500000), MilliSeconds (100));

  // Later, we add IP addresses.  The middle two octets correspond to 

 // the channel number.  

  NS_LOG_INFO ("Assign IP Addresses.");

  PointToPointTopology::AddIpv4Addresses (

      channel0, n0, Ipv4Address ("10.0.0.1"),

      n2, Ipv4Address ("10.0.0.2"));

  PointToPointTopology::AddIpv4Addresses (

      channel1, n1, Ipv4Address ("10.1.1.1"),

      n2, Ipv4Address ("10.1.1.2"));

  PointToPointTopology::AddIpv4Addresses (

      channel2, n2, Ipv4Address ("10.2.2.1"),

      n3, Ipv4Address ("10.2.2.2"));

  PointToPointTopology::AddIpv4Addresses (

      channel3, n1, Ipv4Address ("10.3.3.1"),

      n3, Ipv4Address ("10.3.3.2"));

  PointToPointTopology::SetIpv4Metric (

      channel3, n1, n3, sampleMetric);

  // Create router nodes, initialize routing database and set up the routing

  // tables in the nodes.

  GlobalRouteManager::PopulateRoutingTables ();

  // Create the OnOff application to send UDP datagrams 

  NS_LOG_INFO ("Create Application.");

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

  // Create a flow from n3 to n1, starting at time 1.1 seconds

  Ptr<OnOffApplication> ooff = Create<OnOffApplication> (

    n3, 

    InetSocketAddress ("10.1.1.1", port),

    "Udp",

    ConstantVariable (1), 

    ConstantVariable (0));

  // Start the application

  ooff->Start (Seconds (1.1));

  ooff->Stop (Seconds (10.0));

  // Create a packet sink to receive these packets

  Ptr<PacketSink> sink = Create<PacketSink> (

    n1, 

    InetSocketAddress (Ipv4Address::GetAny (), port), 

    "Udp");

  // Start the sink

  sink->Start (Seconds (1.1));

  sink->Stop (Seconds (10.0));

  // Configure tracing of all enqueue, dequeue, and NetDevice receive events

  // Trace output will be sent to the simple-alternate-routing.tr file

  NS_LOG_INFO ("Configure Tracing.");

  AsciiTrace asciitrace ("simple-alternate-routing.tr");

  asciitrace.TraceAllQueues ();

  asciitrace.TraceAllNetDeviceRx ();

  // Also configure some tcpdump traces; each interface will be traced

  // The output files will be named simple-p2p.pcap-<nodeId>-<interfaceId>

  // and can be read by the "tcpdump -r" command (use "-tt" option to

  // display timestamps correctly)

  PcapTrace pcaptrace ("simple-alternate-routing.pcap");

  pcaptrace.TraceAllIp ();

  NS_LOG_INFO ("Run Simulation.");

  Simulator::Run ();

  Simulator::Destroy ();

  NS_LOG_INFO ("Done.");

  return 0;

}