/*
 * SPDX-License-Identifier: GPL-2.0-only
 */

//
// Example of the sending of a datagram to a broadcast address
//
// Network topology
//     ==============
//       |          |
//       n0    n1   n2
//       |     |
//     ==========
//
//   n0 originates UDP broadcast to 255.255.255.255/discard port, which
//   is replicated and received on both n1 and n2

#include "ns3/applications-module.h"
#include "ns3/core-module.h"
#include "ns3/csma-module.h"
#include "ns3/internet-module.h"
#include "ns3/network-module.h"

#include <cassert>
#include <fstream>
#include <iostream>
#include <string>

using namespace ns3;

NS_LOG_COMPONENT_DEFINE("CsmaBroadcastExample");

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 ("CsmaBroadcastExample", LOG_LEVEL_INFO);
#endif
    LogComponentEnable("CsmaBroadcastExample", LOG_PREFIX_TIME);

    // Allow the user to override any of the defaults and the above
    // Bind()s at run-time, via command-line arguments
    CommandLine cmd(__FILE__);
    cmd.Parse(argc, argv);

    NS_LOG_INFO("Create nodes.");
    NodeContainer c;
    c.Create(3);
    NodeContainer c0 = NodeContainer(c.Get(0), c.Get(1));
    NodeContainer c1 = NodeContainer(c.Get(0), c.Get(2));

    NS_LOG_INFO("Build Topology.");
    CsmaHelper csma;
    csma.SetChannelAttribute("DataRate", DataRateValue(DataRate(5000000)));
    csma.SetChannelAttribute("Delay", TimeValue(MilliSeconds(2)));

    NetDeviceContainer n0 = csma.Install(c0);
    NetDeviceContainer n1 = csma.Install(c1);

    InternetStackHelper internet;
    internet.Install(c);

    NS_LOG_INFO("Assign IP Addresses.");
    Ipv4AddressHelper ipv4;
    ipv4.SetBase("10.1.0.0", "255.255.255.0");
    ipv4.Assign(n0);
    ipv4.SetBase("192.168.1.0", "255.255.255.0");
    ipv4.Assign(n1);

    // RFC 863 discard port ("9") indicates packet should be thrown away
    // by the system.  We allow this silent discard to be overridden
    // by the PacketSink application.
    uint16_t port = 9;

    // Create the OnOff application to send UDP datagrams of size
    // 512 bytes (default) at a rate of 500 Kb/s (default) from n0
    NS_LOG_INFO("Create Applications.");
    OnOffHelper onoff("ns3::UdpSocketFactory",
                      Address(InetSocketAddress(Ipv4Address("255.255.255.255"), port)));
    onoff.SetConstantRate(DataRate("500kb/s"));

    ApplicationContainer app = onoff.Install(c0.Get(0));
    // Start the application
    app.Start(Seconds(1));
    app.Stop(Seconds(10));

    // Create an optional packet sink to receive these packets
    PacketSinkHelper sink("ns3::UdpSocketFactory",
                          Address(InetSocketAddress(Ipv4Address::GetAny(), port)));
    app = sink.Install(c0.Get(1));
    app.Add(sink.Install(c1.Get(1)));
    app.Start(Seconds(1));
    app.Stop(Seconds(10));

    // Configure ascii tracing of all enqueue, dequeue, and NetDevice receive
    // events on all devices.  Trace output will be sent to the file
    // "csma-one-subnet.tr"
    AsciiTraceHelper ascii;
    csma.EnableAsciiAll(ascii.CreateFileStream("csma-broadcast.tr"));

    // Also configure some tcpdump traces; each interface will be traced
    // The output files will be named
    // csma-broadcast-<nodeId>-<interfaceId>.pcap
    // and can be read by the "tcpdump -tt -r" command
    csma.EnablePcapAll("csma-broadcast", false);

    NS_LOG_INFO("Run Simulation.");
    Simulator::Run();
    Simulator::Destroy();
    NS_LOG_INFO("Done.");

    return 0;
}
