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

/*

 * Copyright (c) 2007 Emmanuelle Laprise, 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

 *

 * Authors: Emmanuelle Laprise <emmanuelle.laprise@bluekazoo.ca>

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

 */

#include "packet-socket.h"

#include "packet-socket-address.h"

#include "ns3/log.h"

#include "ns3/node.h"

#include "ns3/packet.h"

#include "ns3/uinteger.h"

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

#include <algorithm>

NS_LOG_COMPONENT_DEFINE ("PacketSocket");

namespace ns3 {

TypeId

PacketSocket::GetTypeId (void)

{

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

    .SetParent<Socket> ()

    .AddConstructor<PacketSocket> ()

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

                     MakeTraceSourceAccessor (&PacketSocket::m_dropTrace))

    .AddAttribute ("RcvBufSize",

                   "PacketSocket maximum receive buffer size (bytes)",

                   UintegerValue (0xffffffffl),

                   MakeUintegerAccessor (&PacketSocket::m_rcvBufSize),

                   MakeUintegerChecker<uint32_t> ())

    ;

  return tid;

}

PacketSocket::PacketSocket () : m_rxAvailable (0)

{

  NS_LOG_FUNCTION_NOARGS ();

  m_state = STATE_OPEN;

  m_shutdownSend = false;

  m_shutdownRecv = false;

  m_errno = ERROR_NOTERROR;

}

void 

PacketSocket::SetNode (Ptr<Node> node)

{

  NS_LOG_FUNCTION_NOARGS ();

  m_node = node;

}

PacketSocket::~PacketSocket ()

{

  NS_LOG_FUNCTION_NOARGS ();

}

void 

PacketSocket::DoDispose (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  m_device = 0;

}

enum Socket::SocketErrno

PacketSocket::GetErrno (void) const

{

  NS_LOG_FUNCTION_NOARGS ();

  return m_errno;

}

Ptr<Node>

PacketSocket::GetNode (void) const

{

  NS_LOG_FUNCTION_NOARGS ();

  return m_node;

}

int

PacketSocket::Bind (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  PacketSocketAddress address;

  address.SetProtocol (0);

  address.SetAllDevices ();

  return DoBind (address);

}

int

PacketSocket::Bind (const Address &address)

{ 

  NS_LOG_FUNCTION_NOARGS ();

  if (!PacketSocketAddress::IsMatchingType (address))

    {

      m_errno = ERROR_INVAL;

      return -1;

    }

  PacketSocketAddress ad = PacketSocketAddress::ConvertFrom (address);

  return DoBind (ad);

}

int

PacketSocket::DoBind (const PacketSocketAddress &address)

{

  NS_LOG_FUNCTION_NOARGS ();

  if (m_state == STATE_BOUND ||

      m_state == STATE_CONNECTED)

    {

      m_errno = ERROR_INVAL;

      return -1;

    }

  if (m_state == STATE_CLOSED)

    {

      m_errno = ERROR_BADF;

      return -1;

    }

  Ptr<NetDevice> dev ;

  if (address.IsSingleDevice ())

    {

      dev = m_node->GetDevice (address.GetSingleDevice ());

    }

  else

    {

      dev = 0;

    }

  m_node->RegisterProtocolHandler (MakeCallback (&PacketSocket::ForwardUp, this),

                                   address.GetProtocol (), dev);

  m_state = STATE_BOUND;

  m_protocol = address.GetProtocol ();

  m_isSingleDevice = address.IsSingleDevice ();

  m_device = address.GetSingleDevice ();

  return 0;

}

int

PacketSocket::ShutdownSend (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  if (m_state == STATE_CLOSED)

    {

      m_errno = ERROR_BADF;

      return -1;

    }

  m_shutdownSend = true;

  return 0;

}

int

PacketSocket::ShutdownRecv (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  if (m_state == STATE_CLOSED)

    {

      m_errno = ERROR_BADF;

      return -1;

    }

  m_shutdownRecv = false;

  return 0;

}

int

PacketSocket::Close(void)

{

  NS_LOG_FUNCTION_NOARGS ();

  if (m_state == STATE_CLOSED)

    {

      m_errno = ERROR_BADF;

      return -1;

    }

  m_state = STATE_CLOSED;

  return 0;

}

int

PacketSocket::Connect(const Address &ad)

{

  NS_LOG_FUNCTION_NOARGS ();

  PacketSocketAddress address;

  if (m_state == STATE_CLOSED)

    {

      m_errno = ERROR_BADF;

      goto error;

    }

  if (m_state == STATE_OPEN)

    {

      // connect should happen _after_ bind.

      m_errno = ERROR_INVAL; // generic error condition.

      goto error;

    }

  if (m_state == STATE_CONNECTED)

    {

      m_errno = ERROR_ISCONN;

      goto error;

    }

  if (!PacketSocketAddress::IsMatchingType (ad))

    {

      m_errno = ERROR_AFNOSUPPORT;

      goto error;

    }

  m_destAddr = ad;

  m_state = STATE_CONNECTED;

  NotifyConnectionSucceeded ();

  return 0;

 error:

  NotifyConnectionFailed ();

  return -1;

}

int 

PacketSocket::Listen(uint32_t queueLimit)

{

  m_errno = Socket::ERROR_OPNOTSUPP;

  return -1;

}

int

PacketSocket::Send (Ptr<Packet> p, uint32_t flags)

{

  NS_LOG_FUNCTION_NOARGS ();

  if (m_state == STATE_OPEN ||

      m_state == STATE_BOUND)

    {

      m_errno = ERROR_NOTCONN;

      return -1;

    }

  return SendTo (p, flags, m_destAddr);

}

uint32_t

PacketSocket::GetMinMtu (PacketSocketAddress ad) const

{

  if (ad.IsSingleDevice ())

    {

      Ptr<NetDevice> device = m_node->GetDevice (ad.GetSingleDevice ());

      return device->GetMtu ();

    }

  else

    {

      uint32_t minMtu = 0xffff;

      for (uint32_t i = 0; i < m_node->GetNDevices (); i++)

        {

          Ptr<NetDevice> device = m_node->GetDevice (i);

          minMtu = std::min (minMtu, (uint32_t)device->GetMtu ());

        }

      return minMtu;

    }

}

uint32_t 

PacketSocket::GetTxAvailable (void) const

{

  if (m_state == STATE_CONNECTED)

    {

      PacketSocketAddress ad = PacketSocketAddress::ConvertFrom (m_destAddr);      

      return GetMinMtu (ad);

    }

  // If we are not connected, we return a 'safe' value by default.

  return 0xffff;

}

int

PacketSocket::SendTo (Ptr<Packet> p, uint32_t flags, const Address &address)

{

  NS_LOG_FUNCTION_NOARGS ();

  PacketSocketAddress ad;

  if (m_state == STATE_CLOSED)

    {

      NS_LOG_LOGIC ("ERROR_BADF");

      m_errno = ERROR_BADF;

      return -1;

    }

  if (m_shutdownSend)

    {

      NS_LOG_LOGIC ("ERROR_SHUTDOWN");

      m_errno = ERROR_SHUTDOWN;

      return -1;

    }

  if (!PacketSocketAddress::IsMatchingType (address))

    {

      NS_LOG_LOGIC ("ERROR_AFNOSUPPORT");

      m_errno = ERROR_AFNOSUPPORT;

      return -1;

    }

  ad = PacketSocketAddress::ConvertFrom (address);

  if (p->GetSize () > GetMinMtu (ad))

    {

      m_errno = ERROR_MSGSIZE;

      return -1;

    }

  bool error = false;

  Address dest = ad.GetPhysicalAddress ();

  if (ad.IsSingleDevice ())

    {

      Ptr<NetDevice> device = m_node->GetDevice (ad.GetSingleDevice ());

      if (!device->Send (p, dest, ad.GetProtocol ()))

        {

          NS_LOG_LOGIC ("error: NetDevice::Send error");

          error = true;

        }

    }

  else

    {

      for (uint32_t i = 0; i < m_node->GetNDevices (); i++)

        {

          Ptr<NetDevice> device = m_node->GetDevice (i);

          if (!device->Send (p, dest, ad.GetProtocol ()))

            {

              NS_LOG_LOGIC ("error: NetDevice::Send error");

              error = true;

            }

        }

    }

  if (!error)

    {

      NotifyDataSent (p->GetSize ());

    }

  if (error)

    {

      NS_LOG_LOGIC ("ERROR_INVAL 2");

      m_errno = ERROR_INVAL;

      return -1;

    }

  else

    {

      return 0;

    }

}

void 

PacketSocket::ForwardUp (Ptr<NetDevice> device, Ptr<const Packet> packet, 

                         uint16_t protocol, const Address &from,

                         const Address &to, NetDevice::PacketType packetType)

{

  NS_LOG_FUNCTION_NOARGS ();

  if (m_shutdownRecv)

    {

      return;

    }

  if (packetType != NetDevice::PACKET_HOST)

    {

      return;

    }

  PacketSocketAddress address;

  address.SetPhysicalAddress (from);

  address.SetSingleDevice (device->GetIfIndex ());

  address.SetProtocol (protocol);

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

    {

      SocketAddressTag tag;

      tag.SetAddress (address);

      packet->AddTag (tag);

      m_deliveryQueue.push (packet->Copy ());

      m_rxAvailable += packet->GetSize ();

      NS_LOG_LOGIC ("UID is " << packet->GetUid() << " PacketSocket " << this);

      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);

    }

}

uint32_t

PacketSocket::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;

}

Ptr<Packet> 

PacketSocket::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;

}

Ptr<Packet>

PacketSocket::RecvFrom (uint32_t maxSize, uint32_t flags, Address &fromAddress)

{

  NS_LOG_FUNCTION_NOARGS ();

  Ptr<Packet> packet = Recv (maxSize, flags);

  if (packet != 0)

    {

      SocketAddressTag tag;

      bool found;

      found = packet->FindFirstMatchingTag (tag);

      NS_ASSERT (found);

      fromAddress = tag.GetAddress ();

    }

  return packet;

}

}//namespace ns3