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

/*

 * Copyright 2007 University of Washington

 * 

 * 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

 */

#include "ns3/log.h"

#include "ns3/ipv4-address.h"

#include "ns3/nstime.h"

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

#include "ns3/socket.h"

#include "ns3/simulator.h"

#include "ns3/socket-factory.h"

#include "ns3/packet.h"

#include "ns3/uinteger.h"

#include "ns3/trace-source-accessor.h"

#include "udp-echo-client.h"

namespace ns3 {

NS_LOG_COMPONENT_DEFINE ("UdpEchoClientApplication");

NS_OBJECT_ENSURE_REGISTERED (UdpEchoClient);

TypeId

UdpEchoClient::GetTypeId (void)

{

  static TypeId tid = TypeId ("ns3::UdpEchoClient")

    .SetParent<Application> ()

    .AddConstructor<UdpEchoClient> ()

    .AddAttribute ("MaxPackets", 

                   "The maximum number of packets the application will send",

                   UintegerValue (100),

                   MakeUintegerAccessor (&UdpEchoClient::m_count),

                   MakeUintegerChecker<uint32_t> ())

    .AddAttribute ("Interval", 

                   "The time to wait between packets",

                   TimeValue (Seconds (1.0)),

                   MakeTimeAccessor (&UdpEchoClient::m_interval),

                   MakeTimeChecker ())

    .AddAttribute ("RemoteAddress", 

                   "The destination Ipv4Address of the outbound packets",

                   Ipv4AddressValue (),

                   MakeIpv4AddressAccessor (&UdpEchoClient::m_peerAddress),

                   MakeIpv4AddressChecker ())

    .AddAttribute ("RemotePort", 

                   "The destination port of the outbound packets",

                   UintegerValue (0),

                   MakeUintegerAccessor (&UdpEchoClient::m_peerPort),

                   MakeUintegerChecker<uint16_t> ())

    .AddAttribute ("PacketSize", "Size of echo data in outbound packets",

                   UintegerValue (100),

                   MakeUintegerAccessor (&UdpEchoClient::SetDataSize,

                                         &UdpEchoClient::GetDataSize),

                   MakeUintegerChecker<uint32_t> ())

    .AddTraceSource ("Tx", "A new packet is created and is sent",

                     MakeTraceSourceAccessor (&UdpEchoClient::m_txTrace))

    ;

  return tid;

}

UdpEchoClient::UdpEchoClient ()

{

  NS_LOG_FUNCTION_NOARGS ();

  m_sent = 0;

  m_socket = 0;

  m_sendEvent = EventId ();

  m_data = 0;

  m_dataSize = 0;

}

UdpEchoClient::~UdpEchoClient()

{

  NS_LOG_FUNCTION_NOARGS ();

  m_socket = 0;

  delete [] m_data;

  m_data = 0;

  m_dataSize = 0;

}

void 

UdpEchoClient::SetRemote (Ipv4Address ip, uint16_t port)

{

  m_peerAddress = ip;

  m_peerPort = port;

}

void

UdpEchoClient::DoDispose (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  Application::DoDispose ();

}

void 

UdpEchoClient::StartApplication (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  if (m_socket == 0)

    {

      TypeId tid = TypeId::LookupByName ("ns3::UdpSocketFactory");

      m_socket = Socket::CreateSocket (GetNode(), tid);

      m_socket->Bind ();

      m_socket->Connect (InetSocketAddress (m_peerAddress, m_peerPort));

    }

  m_socket->SetRecvCallback(MakeCallback(&UdpEchoClient::HandleRead, this));

  ScheduleTransmit (Seconds(0.));

}

void 

UdpEchoClient::StopApplication ()

{

  NS_LOG_FUNCTION_NOARGS ();

  if (m_socket != 0) 

    {

      m_socket->Close ();

      m_socket->SetRecvCallback(MakeNullCallback<void, Ptr<Socket> > ());

    }

  Simulator::Cancel(m_sendEvent);

}

void 

UdpEchoClient::SetDataSize (uint32_t dataSize)

{

  NS_LOG_FUNCTION (dataSize);

  //

  // If the client is setting the echo packet data size this way, we infer

  // that she doesn't care about the contents of the packet at all, so 

  // neither will we.

  //

  delete [] m_data;

  m_data = 0;

  m_dataSize = 0;

  m_size = dataSize;

}

uint32_t 

UdpEchoClient::GetDataSize (void) const

{

  NS_LOG_FUNCTION_NOARGS ();

  return m_size;

}

void 

UdpEchoClient::SetFill (std::string fill)

{

  NS_LOG_FUNCTION (fill);

  uint32_t dataSize = fill.size () + 1;

  if (dataSize != m_dataSize)

    {

      delete [] m_data;

      m_data = new uint8_t [dataSize];

      m_dataSize = dataSize;

    }

  memcpy (m_data, fill.c_str (), dataSize);

  //

  // Overwrite packet size attribute.

  //

  m_size = dataSize;

}

void 

UdpEchoClient::SetFill (uint8_t fill, uint32_t dataSize)

{

  if (dataSize != m_dataSize)

    {

      delete [] m_data;

      m_data = new uint8_t [dataSize];

      m_dataSize = dataSize;

    }

  memset (m_data, fill, dataSize);

  //

  // Overwrite packet size attribute.

  //

  m_size = dataSize;

}

void 

UdpEchoClient::SetFill (uint8_t *fill, uint32_t fillSize, uint32_t dataSize)

{

  if (dataSize != m_dataSize)

    {

      delete [] m_data;

      m_data = new uint8_t [dataSize];

      m_dataSize = dataSize;

    }

  if (fillSize >= dataSize)

    {

      memcpy (m_data, fill, dataSize);

      return;

    }

  //

  // Do all but the final fill.

  //

  uint32_t filled = 0;

  while (filled + fillSize < dataSize)

    {

      memcpy (&m_data[filled], fill, fillSize);

      filled += fillSize;

    }

  //

  // Last fill may be partial

  //

  memcpy(&m_data[filled], fill, dataSize - filled);

  //

  // Overwrite packet size attribute.

  //

  m_size = dataSize;

}

void 

UdpEchoClient::ScheduleTransmit (Time dt)

{

  NS_LOG_FUNCTION_NOARGS ();

  m_sendEvent = Simulator::Schedule(dt, &UdpEchoClient::Send, this);

}

void 

UdpEchoClient::Send (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  NS_ASSERT (m_sendEvent.IsExpired ());

  Ptr<Packet> p;

  if (m_dataSize)

    {

      //

      // If m_dataSize is non-zero, we have a data buffer of the same size that we

      // are expected to copy and send.  This state of affairs is created if one of

      // the Fill functions is called.  In this case, m_size must have been set

      // to agree with m_dataSize

      //

      NS_ASSERT_MSG (m_dataSize == m_size, "UdpEchoClient::Send(): m_size and m_dataSize inconsistent");

      NS_ASSERT_MSG (m_data, "UdpEchoClient::Send(): m_dataSize but no m_data");

      p = Create<Packet> (m_data, m_dataSize);

    }

  else

    {

      //

      // If m_dataSize is zero, the client has indicated that she doesn't care 

      // about the data itself either by specifying the data size by setting

      // the corresponding atribute or by not calling a SetFill function.  In 

      // this case, we don't worry about it either.  But we do allow m_size

      // to have a value different from the (zero) m_dataSize.

      //

      p = Create<Packet> (m_size);

    }

  // call to the trace sinks before the packet is actually sent,

  // so that tags added to the packet can be sent as well

  m_txTrace (p);

  m_socket->Send (p);

  ++m_sent;

  NS_LOG_INFO ("Sent " << m_size << " bytes to " << m_peerAddress);

  if (m_sent < m_count) 

    {

      ScheduleTransmit (m_interval);

    }

}

void

UdpEchoClient::HandleRead (Ptr<Socket> socket)

{

  NS_LOG_FUNCTION (this << socket);

  Ptr<Packet> packet;

  Address from;

  while (packet = socket->RecvFrom (from))

    {

      if (InetSocketAddress::IsMatchingType (from))

        {

          InetSocketAddress address = InetSocketAddress::ConvertFrom (from);

          NS_LOG_INFO ("Received " << packet->GetSize() << " bytes from " <<

            address.GetIpv4());

        }

    }

}

} // Namespace ns3