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

/*

 * Copyright (c) 2007 INRIA

 *

 * 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

 *

 * Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>

 */

#include "ns3/log.h"

#include "ns3/node.h"

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

#include "ns3/ipv4-route.h"

#include "ns3/ipv4.h"

#include "udp-socket.h"

#include "udp-l4-protocol.h"

#include "ipv4-end-point.h"

#include "ipv4-l4-demux.h"

NS_LOG_COMPONENT_DEFINE ("UdpSocket");

namespace ns3 {

TypeId

UdpSocket::GetTypeId (void)

{

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

    .SetParent<Socket> ()

    .AddConstructor<UdpSocket> ()

    .AddTraceSource ("Drop", "Drop UDP packet due to receive buffer overflow",

                     MakeTraceSourceAccessor (&UdpSocket::m_dropTrace))

    ;

  return tid;

}

UdpSocket::UdpSocket ()

  : m_endPoint (0),

    m_node (0),

    m_udp (0),

    m_errno (ERROR_NOTERROR),

    m_shutdownSend (false),

    m_shutdownRecv (false),

    m_connected (false),

    m_rxAvailable (0),

    m_sndBufLimit (0),

    m_rcvBufLimit (0)

{

  NS_LOG_FUNCTION_NOARGS ();

}

UdpSocket::~UdpSocket ()

{

  NS_LOG_FUNCTION_NOARGS ();

  m_node = 0;

  if (m_endPoint != 0)

    {

      NS_ASSERT (m_udp != 0);

      /**

       * Note that this piece of code is a bit tricky:

       * when DeAllocate is called, it will call into

       * Ipv4EndPointDemux::Deallocate which triggers

       * a delete of the associated endPoint which triggers

       * in turn a call to the method ::Destroy below

       * will will zero the m_endPoint field.

       */

      NS_ASSERT (m_endPoint != 0);

      m_udp->DeAllocate (m_endPoint);

      NS_ASSERT (m_endPoint == 0);

    }

  m_udp = 0;

}

void 

UdpSocket::SetNode (Ptr<Node> node)

{

  NS_LOG_FUNCTION_NOARGS ();

  m_node = node;

}

void 

UdpSocket::SetUdp (Ptr<UdpL4Protocol> udp)

{

  NS_LOG_FUNCTION_NOARGS ();

  m_udp = udp;

}

enum Socket::SocketErrno

UdpSocket::GetErrno (void) const

{

  NS_LOG_FUNCTION_NOARGS ();

  return m_errno;

}

Ptr<Node>

UdpSocket::GetNode (void) const

{

  NS_LOG_FUNCTION_NOARGS ();

  return m_node;

}

void 

UdpSocket::Destroy (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  m_node = 0;

  m_endPoint = 0;

  m_udp = 0;

}

int

UdpSocket::FinishBind (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  if (m_endPoint == 0)

    {

      return -1;

    }

  m_endPoint->SetRxCallback (MakeCallback (&UdpSocket::ForwardUp, this));

  m_endPoint->SetDestroyCallback (MakeCallback (&UdpSocket::Destroy, this));

  return 0;

}

int

UdpSocket::Bind (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  m_endPoint = m_udp->Allocate ();

  return FinishBind ();

}

int 

UdpSocket::Bind (const Address &address)

{

  NS_LOG_FUNCTION (this << address);

  if (!InetSocketAddress::IsMatchingType (address))

    {

      NS_LOG_ERROR ("Not IsMatchingType");

      return ERROR_INVAL;

    }

  InetSocketAddress transport = InetSocketAddress::ConvertFrom (address);

  Ipv4Address ipv4 = transport.GetIpv4 ();

  uint16_t port = transport.GetPort ();

  if (ipv4 == Ipv4Address::GetAny () && port == 0)

    {

      m_endPoint = m_udp->Allocate ();

    }

  else if (ipv4 == Ipv4Address::GetAny () && port != 0)

    {

      m_endPoint = m_udp->Allocate (port);

    }

  else if (ipv4 != Ipv4Address::GetAny () && port == 0)

    {

      m_endPoint = m_udp->Allocate (ipv4);

    }

  else if (ipv4 != Ipv4Address::GetAny () && port != 0)

    {

      m_endPoint = m_udp->Allocate (ipv4, port);

    }

  return FinishBind ();

}

int 

UdpSocket::ShutdownSend (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  m_shutdownSend = true;

  return 0;

}

int 

UdpSocket::ShutdownRecv (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  m_shutdownRecv = false;

  return 0;

}

int

UdpSocket::Close(void)

{

  NS_LOG_FUNCTION_NOARGS ();

  NotifyCloseCompleted ();

  return 0;

}

int

UdpSocket::Connect(const Address & address)

{

  NS_LOG_FUNCTION (this << address);

  Ipv4Route routeToDest;

  InetSocketAddress transport = InetSocketAddress::ConvertFrom (address);

  m_defaultAddress = transport.GetIpv4 ();

  m_defaultPort = transport.GetPort ();

  NotifyConnectionSucceeded ();

  m_connected = true;

  return 0;

}

int 

UdpSocket::Send (Ptr<Packet> p)

{

  NS_LOG_FUNCTION (this << p);

  if (!m_connected)

    {

      m_errno = ERROR_NOTCONN;

      return -1;

    }

  return DoSend (p);

}

int 

UdpSocket::DoSend (Ptr<Packet> p)

{

  NS_LOG_FUNCTION_NOARGS ();

  if (m_endPoint == 0)

    {

      if (Bind () == -1)

       {

          NS_ASSERT (m_endPoint == 0);

         return -1;

       }

      NS_ASSERT (m_endPoint != 0);

    }

  if (m_shutdownSend)

    {

      m_errno = ERROR_SHUTDOWN;

      return -1;

    } 

  return DoSendTo (p, m_defaultAddress, m_defaultPort);

}

int

UdpSocket::DoSendTo (Ptr<Packet> p, const Address &address)

{

  NS_LOG_FUNCTION (this << p << address);

  if (!m_connected)

    {

      NS_LOG_LOGIC ("Not connected");

      InetSocketAddress transport = InetSocketAddress::ConvertFrom (address);

      Ipv4Address ipv4 = transport.GetIpv4 ();

      uint16_t port = transport.GetPort ();

      return DoSendTo (p, ipv4, port);

    }

  else

    {

      // connected UDP socket must use default addresses

      NS_LOG_LOGIC ("Connected");

      return DoSendTo (p, m_defaultAddress, m_defaultPort);

    }

}

int

UdpSocket::DoSendTo (Ptr<Packet> p, Ipv4Address dest, uint16_t port)

{

  NS_LOG_FUNCTION (this << p << dest << port);

  Ipv4Route routeToDest;

  if (m_endPoint == 0)

    {

      if (Bind () == -1)

	{

          NS_ASSERT (m_endPoint == 0);

	  return -1;

	}

      NS_ASSERT (m_endPoint != 0);

    }

  if (m_shutdownSend)

    {

      m_errno = ERROR_SHUTDOWN;

      return -1;

    }

  uint32_t localIfIndex;

  Ptr<Ipv4> ipv4 = m_node->GetObject<Ipv4> ();

  //

  // If dest is sent to the limited broadcast address (all ones),

  // convert it to send a copy of the packet out of every interface

  //

  if (dest.IsBroadcast ())

    {

      NS_LOG_LOGIC ("Limited broadcast start.");

      for (uint32_t i = 0; i < ipv4->GetNInterfaces (); i++ )

        {

          Ipv4Address addri = ipv4->GetAddress (i);

          Ipv4Mask maski = ipv4->GetNetworkMask (i);

          Ipv4Address bcast = addri.GetSubnetDirectedBroadcast (maski);

          NS_LOG_LOGIC ("Sending one copy from " << addri << " to " << bcast

                        << " (mask is " << maski << ")");

          m_udp->Send (p->Copy (), addri, bcast,

                       m_endPoint->GetLocalPort (), port);

          NotifyDataSent (p->GetSize ());

        }

      NS_LOG_LOGIC ("Limited broadcast end.");

      return p->GetSize();

    }

  else if (ipv4->GetIfIndexForDestination(dest, localIfIndex))

    {

      NS_LOG_LOGIC ("Route exists");

      m_udp->Send (p->Copy (), ipv4->GetAddress (localIfIndex), dest,

		   m_endPoint->GetLocalPort (), port);

      NotifyDataSent (p->GetSize ());

      return p->GetSize();;

    }

  else

   {

      NS_LOG_ERROR ("ERROR_NOROUTETOHOST");

      m_errno = ERROR_NOROUTETOHOST;

      return -1;

   }

  return 0;

}

uint32_t

UdpSocket::GetTxAvailable (void) const

{

  NS_LOG_FUNCTION_NOARGS ();

  // No finite send buffer is modelled

  return std::numeric_limits<uint32_t>::max ();

}

int 

UdpSocket::SendTo (const Address &address, Ptr<Packet> p)

{

  NS_LOG_FUNCTION (this << address << p);

  InetSocketAddress transport = InetSocketAddress::ConvertFrom (address);

  Ipv4Address ipv4 = transport.GetIpv4 ();

  uint16_t port = transport.GetPort ();

  return DoSendTo (p, ipv4, port);

}

Ptr<Packet>

UdpSocket::Recv (uint32_t maxSize, uint32_t flags)

{

  NS_LOG_FUNCTION_NOARGS ();

  if (m_deliveryQueue.empty() )

    {

      return 0;

    }

  Ptr<Packet> p = m_deliveryQueue.front ();

  if (p->GetSize () <= maxSize) 

    {

      m_deliveryQueue.pop ();

      m_rxAvailable -= p->GetSize ();

    }

  else

    {

      p = 0; 

    }

  return p;

}

uint32_t

UdpSocket::GetRxAvailable (void) const

{

  NS_LOG_FUNCTION_NOARGS ();

  // We separately maintain this state to avoid walking the queue 

  // every time this might be called

  return m_rxAvailable;

}

void 

UdpSocket::ForwardUp (Ptr<Packet> packet, Ipv4Address ipv4, uint16_t port)

{

  NS_LOG_FUNCTION (this << packet << ipv4 << port);

  if (m_shutdownRecv)

    {

      return;

    }

  if ((m_rxAvailable + packet->GetSize ()) <= m_rcvBufLimit)

    {

      Address address = InetSocketAddress (ipv4, port);

      SocketRxAddressTag tag;

      tag.SetAddress (address);

      packet->AddTag (tag);

      m_deliveryQueue.push (packet);

      m_rxAvailable += packet->GetSize ();

      NotifyDataRecv ();

    }

  else

    {

      // In general, this case should not occur unless the

      // receiving application reads data from this socket slowly

      // in comparison to the arrival rate

      //

      // drop and trace packet

      NS_LOG_WARN ("No receive buffer space available.  Drop.");

      m_dropTrace (packet);

    }

}

void 

UdpSocket::SetSndBuf (uint32_t size)

{

  NS_LOG_FUNCTION_NOARGS ();

  // return EINVAL since we are not modelling a finite send buffer

  // Enforcing buffer size should be added if we ever start to model

  // non-zero processing delay in the UDP/IP stack

  NS_LOG_WARN ("UdpSocket has infinite send buffer");

  m_sndBufLimit = size; 

}

uint32_t 

UdpSocket::GetSndBuf (void) const

{

  NS_LOG_FUNCTION_NOARGS ();

  return m_sndBufLimit;

}

void 

UdpSocket::SetRcvBuf (uint32_t size)

{

  NS_LOG_FUNCTION_NOARGS ();

  m_rcvBufLimit = size;

}

uint32_t 

UdpSocket::GetRcvBuf (void) const

{

  NS_LOG_FUNCTION_NOARGS ();

  return m_rcvBufLimit;

}

} //namespace ns3

#ifdef RUN_SELF_TESTS

#include "ns3/test.h"

#include "ns3/socket-factory.h"

#include "ns3/udp.h"

#include "ns3/simulator.h"

#include "ns3/simple-channel.h"

#include "ns3/simple-net-device.h"

#include "ns3/drop-tail-queue.h"

#include "internet-stack.h"

#include <string>

namespace ns3 {

class UdpSocketTest: public Test

{

  Ptr<Packet> m_receivedPacket;

  Ptr<Packet> m_receivedPacket2;

public:

  virtual bool RunTests (void);

  UdpSocketTest ();

  void ReceivePacket (Ptr<Socket> socket, Ptr<Packet> packet, const Address &from);

  void ReceivePacket2 (Ptr<Socket> socket, Ptr<Packet> packet, const Address &from);

  void ReceivePkt (Ptr<Socket> socket);