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

/*

 * Copyright (c) 2007 Georgia Tech Research Corporation

 *

 * 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: Raj Bhattacharjea <raj.b@gatech.edu>

 */

#include "ns3/node.h"

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

#include "ns3/log.h"

#include "ns3/ipv4.h"

#include "tcp-socket.h"

#include "tcp-l4-protocol.h"

#include "ipv4-end-point.h"

#include "ipv4-l4-demux.h"

#include "ns3/simulation-singleton.h"

#include "tcp-typedefs.h"

#include "ns3/simulator.h"

#include "ns3/packet.h"

#include <algorithm>

NS_LOG_COMPONENT_DEFINE ("TcpSocket");

using namespace std;

namespace ns3 {

  TcpSocket::TcpSocket ()

  : m_skipRetxResched (false),

    m_dupAckCount (0),

    m_endPoint (0),

    m_node (0),

    m_tcp (0),

    m_errno (ERROR_NOTERROR),

    m_shutdownSend (false),

    m_shutdownRecv (false),

    m_connected (false),

    m_state (CLOSED),

    m_closeNotified (false),

    m_closeRequestNotified (false),

    m_closeOnEmpty (false),

    m_pendingClose (false),

    m_nextTxSequence (0),

    m_highTxMark (0),

    m_highestRxAck (0),

    m_lastRxAck (0),

    m_nextRxSequence (0),

    m_pendingData (0),

    m_rtt (0),

    m_lastMeasuredRtt (Seconds(0.0))

{

  NS_LOG_FUNCTION;

  NS_LOG_PARAMS (this);

}

TcpSocket::TcpSocket(const TcpSocket& sock)

  : Socket(sock), //copy the base class callbacks

    m_skipRetxResched (sock.m_skipRetxResched),

    m_dupAckCount (sock.m_dupAckCount),

    m_endPoint (0),

    m_node (sock.m_node),

    m_tcp (sock.m_tcp),

    m_remoteAddress (sock.m_remoteAddress),

    m_remotePort (sock.m_remotePort),

    m_localAddress (sock.m_localAddress),

    m_localPort (sock.m_localPort),

    m_errno (sock.m_errno),

    m_shutdownSend (sock.m_shutdownSend),

    m_shutdownRecv (sock.m_shutdownRecv),

    m_connected (sock.m_connected),

    m_state (sock.m_state),

    m_closeNotified (sock.m_closeNotified),

    m_closeRequestNotified (sock.m_closeRequestNotified),

    m_closeOnEmpty (sock.m_closeOnEmpty),

    m_pendingClose (sock.m_pendingClose),

    m_nextTxSequence (sock.m_nextTxSequence),

    m_highTxMark (sock.m_highTxMark),

    m_highestRxAck (sock.m_highestRxAck),

    m_lastRxAck (sock.m_lastRxAck),

    m_nextRxSequence (sock.m_nextRxSequence),

    m_pendingData (0),

    m_segmentSize (sock.m_segmentSize),

    m_rxWindowSize (sock.m_rxWindowSize),

    m_advertisedWindowSize (sock.m_advertisedWindowSize),

    m_cWnd (sock.m_cWnd),

    m_ssThresh (sock.m_ssThresh),

    m_initialCWnd (sock.m_initialCWnd),

    m_rtt (0),

    m_lastMeasuredRtt (Seconds(0.0)),

    m_cnTimeout (sock.m_cnTimeout),

    m_cnCount (sock.m_cnCount)

{

  NS_LOG_FUNCTION;

  NS_LOG_LOGIC("Invoked the copy constructor");

  //copy the pending data if necessary

  if(sock.m_pendingData)

    {

      m_pendingData = sock.m_pendingData->Copy();

    }

  //copy the rtt if necessary

  if (sock.m_rtt)

    {

      m_rtt = sock.m_rtt->Copy();

    }

  //can't "copy" the endpoint just yes, must do this when we know the peer info

  //too; this is in SYN_ACK_TX

}

TcpSocket::~TcpSocket ()

{

  NS_LOG_FUNCTION;

  NS_LOG_PARAMS(this);

  m_node = 0;

  if (m_endPoint != 0)

    {

      NS_ASSERT (m_tcp != 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_tcp->DeAllocate (m_endPoint);

      NS_ASSERT (m_endPoint == 0);

    }

  m_tcp = 0;

  delete m_pendingData; //prevents leak

  m_pendingData = 0;

}

void

TcpSocket::SetNode (Ptr<Node> node)

{

  m_node = node;

  Ptr<Tcp> t = node->GetObject<Tcp> ();

  m_segmentSize = t->GetDefaultSegSize ();

  m_rxWindowSize = t->GetDefaultAdvWin ();

  m_advertisedWindowSize = t->GetDefaultAdvWin ();

  m_cWnd = t->GetDefaultInitialCwnd () * m_segmentSize;

  m_ssThresh = t->GetDefaultSsThresh ();

  m_initialCWnd = t->GetDefaultInitialCwnd ();

  m_cnTimeout = Seconds (t->GetDefaultConnTimeout ());

  m_cnCount = t->GetDefaultConnCount ();

}

void 

TcpSocket::SetTcp (Ptr<TcpL4Protocol> tcp)

{

  m_tcp = tcp;

}

void 

TcpSocket::SetRtt (Ptr<RttEstimator> rtt)

{

  m_rtt = rtt;

}

enum Socket::SocketErrno

TcpSocket::GetErrno (void) const

{

  NS_LOG_FUNCTION;

  return m_errno;

}

Ptr<Node>

TcpSocket::GetNode (void) const

{

  NS_LOG_FUNCTION;

  return m_node;

}

void 

TcpSocket::Destroy (void)

{

  NS_LOG_FUNCTION;

  m_node = 0;

  m_endPoint = 0;

  m_tcp = 0;

  m_retxEvent.Cancel ();

}

int

TcpSocket::FinishBind (void)

{

  NS_LOG_FUNCTION;

  if (m_endPoint == 0)

    {

      return -1;

    }

  m_endPoint->SetRxCallback (MakeCallback (&TcpSocket::ForwardUp, Ptr<TcpSocket>(this)));

  m_endPoint->SetDestroyCallback (MakeCallback (&TcpSocket::Destroy, Ptr<TcpSocket>(this)));

  m_localAddress = m_endPoint->GetLocalAddress ();

  m_localPort = m_endPoint->GetLocalPort ();

  return 0;

}

int

TcpSocket::Bind (void)

{

  NS_LOG_FUNCTION;

  m_endPoint = m_tcp->Allocate ();

  return FinishBind ();

}

int 

TcpSocket::Bind (const Address &address)

{

  NS_LOG_FUNCTION;

  NS_LOG_PARAMS (this<<address);

  if (!InetSocketAddress::IsMatchingType (address))

    {

      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_tcp->Allocate ();

      NS_LOG_LOGIC ("TcpSocket "<<this<<" got an endpoint: "<<m_endPoint);

    }

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

    {

      m_endPoint = m_tcp->Allocate (port);

      NS_LOG_LOGIC ("TcpSocket "<<this<<" got an endpoint: "<<m_endPoint);

    }

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

    {

      m_endPoint = m_tcp->Allocate (ipv4);

      NS_LOG_LOGIC ("TcpSocket "<<this<<" got an endpoint: "<<m_endPoint);

    }

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

    {

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

      NS_LOG_LOGIC ("TcpSocket "<<this<<" got an endpoint: "<<m_endPoint);

    }

  return FinishBind ();

}

int 

TcpSocket::ShutdownSend (void)

{

  NS_LOG_FUNCTION;

  m_shutdownSend = true;

  return 0;

}

int 

TcpSocket::ShutdownRecv (void)

{

  NS_LOG_FUNCTION;

  m_shutdownRecv = false;

  return 0;

}

int

TcpSocket::Close (void)

{

  NS_LOG_FUNCTION;

  if (m_state == CLOSED) 

    {

      return -1;

    }

  if (m_pendingData && m_pendingData->Size() != 0)

    { // App close with pending data must wait until all data transmitted

      m_closeOnEmpty = true;

      NS_LOG_LOGIC("Socket " << this << 

                   " deferring close, state " << m_state);

      return 0;

    }

  Actions_t action  = ProcessEvent (APP_CLOSE);

  ProcessAction (action);

  ShutdownSend ();

  return 0;

}

int

TcpSocket::Connect (const Address & address)

{

  NS_LOG_FUNCTION;

  NS_LOG_PARAMS (this << address);

  if (m_endPoint == 0)

    {

      if (Bind () == -1)

        {

          NS_ASSERT (m_endPoint == 0);

          return -1;

        }

      NS_ASSERT (m_endPoint != 0);

    }

  InetSocketAddress transport = InetSocketAddress::ConvertFrom (address);

  m_remoteAddress = transport.GetIpv4 ();

  m_remotePort = transport.GetPort ();

  uint32_t localIfIndex;

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

  if (ipv4->GetIfIndexForDestination (m_remoteAddress, localIfIndex))

    {

      m_endPoint->SetLocalAddress (ipv4->GetAddress (localIfIndex));

    }

  else

    {

      m_errno = ERROR_NOROUTETOHOST;

      return -1;

    }

  Actions_t action = ProcessEvent (APP_CONNECT);

  bool success = ProcessAction (action);

  if (success) 

    {

      return 0;

    }

  return -1;

}

int 

TcpSocket::Send (const Ptr<Packet> p) //p here is just data, no headers

{ // TCP Does not deal with packets from app, just data

  return Send(p->PeekData(), p->GetSize());

}

int TcpSocket::Send (const uint8_t* buf, uint32_t size)

{

  NS_LOG_FUNCTION;

  NS_LOG_PARAMS (this << buf << size);

  if (m_state == ESTABLISHED || m_state == SYN_SENT || m_state == CLOSE_WAIT)

    { // Ok to buffer some data to send

      if (!m_pendingData)

      {

        m_pendingData = new PendingData ();   // Create if non-existent

        m_firstPendingSequence = m_nextTxSequence; // Note seq of first

      }

      //PendingData::Add always copies the data buffer, never modifies

      m_pendingData->Add (size,buf);

      NS_LOG_DEBUG("TcpSock::Send, pdsize " << m_pendingData->Size() << 

                   " state " << m_state);

      Actions_t action = ProcessEvent (APP_SEND);

      NS_LOG_DEBUG(" action " << action);

      if (!ProcessAction (action)) 

        {

          return -1; // Failed, return zero

        }

      return size;

    }

  else

  {

    m_errno = ERROR_NOTCONN;

    return -1;

  }

}

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

{

  NS_LOG_FUNCTION;

  NS_LOG_PARAMS (this << p << address);

  InetSocketAddress transport = InetSocketAddress::ConvertFrom (address);

  Ipv4Address ipv4 = transport.GetIpv4 ();

  uint16_t port = transport.GetPort ();

  return DoSendTo (p, ipv4, port);

}

int TcpSocket::DoSendTo (Ptr<Packet> p, Ipv4Address ipv4, uint16_t port)

{

  NS_LOG_FUNCTION;

  NS_LOG_PARAMS (this << p << ipv4 << port);

  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;

    }

  m_tcp->Send (p, m_endPoint->GetLocalAddress (), ipv4,

                  m_endPoint->GetLocalPort (), port);

  NotifyDataSent (p->GetSize ());

  return 0;

}

int 

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

{

  NS_LOG_FUNCTION;

  NS_LOG_PARAMS (this << address << p);

  if (!m_connected)

    {

      m_errno = ERROR_NOTCONN;

      return -1;

    }

  else

    {

      return Send (p); //drop the address according to BSD manpages

    }

}

int

TcpSocket::Listen (uint32_t q)

{

  NS_LOG_FUNCTION;

  NS_LOG_PARAMS (this << q);

  Actions_t action = ProcessEvent (APP_LISTEN);

  ProcessAction (action);

  return 0;

}

void

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

{

  NS_LOG_DEBUG("Socket " << this << " got forward up" <<

               " dport " << m_endPoint->GetLocalPort() <<

               " daddr " << m_endPoint->GetLocalAddress() <<

               " sport " << m_endPoint->GetPeerPort() <<

               " saddr " << m_endPoint->GetPeerAddress());

  NS_LOG_FUNCTION;

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

  if (m_shutdownRecv)

    {

      return;

    }

  TcpHeader tcpHeader;

  packet->RemoveHeader (tcpHeader);

  if (tcpHeader.GetFlags () & TcpHeader::ACK)

    {

      Time m = m_rtt->AckSeq (tcpHeader.GetAckNumber () );

      if (m != Seconds (0.0))

        {

          m_lastMeasuredRtt = m;

        }

    }

  Events_t event = SimulationSingleton<TcpStateMachine>::Get ()->FlagsEvent (tcpHeader.GetFlags () );

  Actions_t action = ProcessEvent (event); //updates the state

  Address address = InetSocketAddress (ipv4, port);

  NS_LOG_DEBUG("Socket " << this << 

               " processing pkt action, " << action <<

               " current state " << m_state);

  ProcessPacketAction (action, packet, tcpHeader, address);

}

Actions_t TcpSocket::ProcessEvent (Events_t e)

{

  NS_LOG_FUNCTION;

  NS_LOG_PARAMS (this << e);

  States_t saveState = m_state;

  NS_LOG_LOGIC ("TcpSocket " << this << " processing event " << e);

  // simulation singleton is a way to get a single global static instance of a

  // class intended to be a singleton; see simulation-singleton.h

  SA stateAction = SimulationSingleton<TcpStateMachine>::Get ()->Lookup (m_state,e);

  // debug

  if (stateAction.action == RST_TX)

    {

      NS_LOG_LOGIC ("TcpSocket " << this << " sending RST from state "

              << saveState << " event " << e);

    }

  bool needCloseNotify = (stateAction.state == CLOSED && m_state != CLOSED 

    && e != TIMEOUT);

  m_state = stateAction.state;

  NS_LOG_LOGIC ("TcpSocket " << this << " moved from state " << saveState 

    << " to state " <<m_state);

  NS_LOG_LOGIC ("TcpSocket " << this << " pendingData " << m_pendingData);

  //extra event logic is here for RX events

  //e = SYN_ACK_RX

  if (saveState == SYN_SENT && m_state == ESTABLISHED)

    // this means the application side has completed its portion of 

    // the handshaking

    {

      Simulator::ScheduleNow(&TcpSocket::ConnectionSucceeded, this);

      //NotifyConnectionSucceeded ();

      m_connected = true;

      m_endPoint->SetPeer (m_remoteAddress, m_remotePort);

      NS_LOG_LOGIC ("TcpSocket " << this << " Connected!");

    }

  if (needCloseNotify && !m_closeNotified)

    {

      NS_LOG_LOGIC ("TcpSocket " << this << " transition to CLOSED from " 

               << m_state << " event " << e << " closeNot " << m_closeNotified

               << " action " << stateAction.action);

      NotifyCloseCompleted ();

      m_closeNotified = true;

      NS_LOG_LOGIC ("TcpSocket " << this << " calling Closed from PE"

              << " origState " << saveState

              << " event " << e);

      NS_LOG_LOGIC ("TcpSocket " << this << " transition to CLOSED from "

          << m_state << " event " << e

          << " set CloseNotif ");

    }

  return stateAction.action;

}

void TcpSocket::SendEmptyPacket (uint8_t flags)

{

  NS_LOG_FUNCTION;

  NS_LOG_PARAMS (this << flags);

  Ptr<Packet> p = Create<Packet> ();

  TcpHeader header;

  header.SetFlags (flags);

  header.SetSequenceNumber (m_nextTxSequence);

  header.SetAckNumber (m_nextRxSequence);

  header.SetSourcePort (m_endPoint->GetLocalPort ());

  header.SetDestinationPort (m_remotePort);

  header.SetWindowSize (m_advertisedWindowSize);

  m_tcp->SendPacket (p, header, m_endPoint->GetLocalAddress (), 

    m_remoteAddress);

  Time rto = m_rtt->RetransmitTimeout ();

  if (flags & TcpHeader::SYN)

    {

      rto = m_cnTimeout;

      m_cnTimeout = m_cnTimeout + m_cnTimeout;

      m_cnCount--;

    }

  if (m_retxEvent.IsExpired () ) //no outstanding timer

  {

    NS_LOG_LOGIC ("Schedule retransmission timeout at time " 

          << Simulator::Now ().GetSeconds () << " to expire at time " 

          << (Simulator::Now () + rto).GetSeconds ());

    m_retxEvent = Simulator::Schedule (rto, &TcpSocket::ReTxTimeout, this);

  }

}

bool TcpSocket::ProcessAction (Actions_t a)

{ // These actions do not require a packet or any TCP Headers

  NS_LOG_FUNCTION;

  NS_LOG_PARAMS (this << a);

  switch (a)

  {

    case NO_ACT:

      NS_LOG_LOGIC ("TcpSocket " << this <<" Action: NO_ACT");

      break;

    case ACK_TX:

      SendEmptyPacket (TcpHeader::ACK);

      break;

    case ACK_TX_1:

      NS_ASSERT (false); // This should be processed in ProcessPacketAction

      break;

    case RST_TX:

      NS_LOG_LOGIC ("TcpSocket " << this <<" Action RST_TX");

      SendEmptyPacket (TcpHeader::RST);

      break;

    case SYN_TX:

      NS_LOG_LOGIC ("TcpSocket " << this <<" Action SYN_TX");

      // TCP SYN Flag consumes one byte

      // is the above correct? we're SENDING a syn, not acking back -- Raj

      // commented out for now

      // m_nextTxSequence+= 1;

      SendEmptyPacket (TcpHeader::SYN);

      break;

    case SYN_ACK_TX:

      NS_LOG_LOGIC ("TcpSocket " << this <<" Action SYN_ACK_TX");

      // TCP SYN Flag consumes one byte

      ++m_nextRxSequence;

      SendEmptyPacket (TcpHeader::SYN | TcpHeader::ACK);

      break;

    case FIN_TX:

      NS_LOG_LOGIC ("TcpSocket " << this <<" Action FIN_TX");

      SendEmptyPacket (TcpHeader::FIN);

      break;

    case FIN_ACK_TX:

      NS_LOG_LOGIC ("TcpSocket " << this <<" Action FIN_ACK_TX");

      SendEmptyPacket (TcpHeader::FIN | TcpHeader::ACK);

      break;

    case NEW_ACK:

      NS_ASSERT (false); // This should be processed in ProcessPacketAction

      break;

    case NEW_SEQ_RX:

      NS_ASSERT (false); // This should be processed in ProcessPacketAction

      break;

    case RETX:

      NS_LOG_LOGIC ("TcpSocket " << this <<" Action RETX");

      break;

    case TX_DATA:

      NS_LOG_LOGIC ("TcpSocket " << this <<" Action TX_DATA");

      SendPendingData ();

      break;

    case PEER_CLOSE:

      NS_ASSERT (false); // This should be processed in ProcessPacketAction

      NS_LOG_LOGIC ("TcpSocket " << this <<" Action PEER_CLOSE");

      break;

    case APP_CLOSED:

      NS_LOG_LOGIC ("TcpSocket " << this <<" Action APP_CLOSED");

      break;

    case CANCEL_TM:

      NS_LOG_LOGIC ("TcpSocket " << this <<" Action CANCEL_TM");

      break;

    case APP_NOTIFY:

      NS_LOG_LOGIC ("TcpSocket " << this <<" Action APP_NOTIFY");

      break;

    case SERV_NOTIFY:

      NS_ASSERT (false); // This should be processed in ProcessPacketAction

      break;

    case LAST_ACTION:

      NS_LOG_LOGIC ("TcpSocket " << this <<" Action LAST_ACTION");

      break;

  }

  return true;

}

bool TcpSocket::ProcessPacketAction (Actions_t a, Ptr<Packet> p,

                                     const TcpHeader& tcpHeader,

                                     const Address& fromAddress)

{

  NS_LOG_FUNCTION;

  NS_LOG_PARAMS (this << a << p  << fromAddress);

  uint32_t localIfIndex;

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

  switch (a)

  {

    case SYN_ACK_TX:

      NS_LOG_LOGIC ("TcpSocket " << this <<" Action SYN_ACK_TX");

//      m_remotePort = InetSocketAddress::ConvertFrom (fromAddress).GetPort ();

//      m_remoteAddress = InetSocketAddress::ConvertFrom (fromAddress).GetIpv4 ();

//       if (ipv4->GetIfIndexForDestination (m_remoteAddress, localIfIndex))

//         {

//           m_localAddress = ipv4->GetAddress (localIfIndex);

//         }

      if (m_state == LISTEN) //this means we should fork a new TcpSocket

        {

          NS_LOG_DEBUG("In SYN_ACK_TX, m_state is LISTEN, this " << this);

          //notify the server that we got a SYN

          // If server refuses connection do nothing

          if (!NotifyConnectionRequest(fromAddress)) return true;

          // Clone the socket

          Ptr<TcpSocket> newSock = Copy ();

          NS_LOG_LOGIC ("Cloned a TcpSocket " << newSock);

          //this listening socket should do nothing more

          Simulator::ScheduleNow (&TcpSocket::CompleteFork, newSock,

                                  p, tcpHeader,fromAddress);

          return true;

        }

        // This is the cloned endpoint

        m_endPoint->SetPeer (m_remoteAddress, m_remotePort);

        if (ipv4->GetIfIndexForDestination (m_remoteAddress, localIfIndex))

          {

            m_localAddress = ipv4->GetAddress (localIfIndex);

            m_endPoint->SetLocalAddress (m_localAddress);

            // Leave local addr in the portmap to any, as the path from

            // remote can change and packets can arrive on different interfaces

            //m_endPoint->SetLocalAddress (Ipv4Address::GetAny());

          }

        // TCP SYN consumes one byte

        m_nextRxSequence = tcpHeader.GetSequenceNumber() + SequenceNumber(1);

        SendEmptyPacket (TcpHeader::SYN | TcpHeader::ACK);

      break;

    case ACK_TX_1:

      NS_LOG_LOGIC ("TcpSocket " << this <<" Action ACK_TX_1");

      // TCP SYN consumes one byte

      m_nextRxSequence = tcpHeader.GetSequenceNumber() + SequenceNumber(1);

      NS_LOG_DEBUG ("TcpSocket " << this << " ACK_TX_1" <<

                    " nextRxSeq " << m_nextRxSequence);

      SendEmptyPacket (TcpHeader::ACK);

      m_rxWindowSize = tcpHeader.GetWindowSize ();

      m_nextTxSequence = tcpHeader.GetAckNumber ();

      if (tcpHeader.GetAckNumber () > m_highestRxAck)

      {

        m_highestRxAck = tcpHeader.GetAckNumber ();

      }

      SendPendingData ();

      break;

    case NEW_ACK:

      NS_LOG_LOGIC ("TcpSocket " << this <<" Action NEW_ACK_TX");

      if (tcpHeader.GetAckNumber () < m_highestRxAck) //old ack, do nothing

      {

        break;

      }

      if (tcpHeader.GetAckNumber () == m_highestRxAck && 

         tcpHeader.GetAckNumber ()  < m_nextTxSequence)

      {

        DupAck (tcpHeader, ++m_dupAckCount);

        break;

      }

      if (tcpHeader.GetAckNumber () > m_highestRxAck)  

        {

          m_dupAckCount = 0;

        }

      NewAck (tcpHeader.GetAckNumber ());

      break;

    case NEW_SEQ_RX:

      NS_LOG_LOGIC ("TcpSocket " << this <<" Action NEW_SEQ_RX");

      NewRx (p, tcpHeader, fromAddress); // Process new data received

      break;

    case PEER_CLOSE:

    {

      // First we have to be sure the FIN packet was not received

      // out of sequence.  If so, note pending close and process

      // new sequence rx

      if (tcpHeader.GetSequenceNumber () != m_nextRxSequence)

        { // process close later

          m_pendingClose = true;

          NS_LOG_LOGIC ("TcpSocket " << this << " setting pendingClose" 

            << " rxseq " << tcpHeader.GetSequenceNumber () 

            << " nextRxSeq " << m_nextRxSequence);

          NewRx (p, tcpHeader, fromAddress);

          return true;

        }

      // Now we need to see if any data came with the FIN

      // if so, call NewRx

      if (p->GetSize () != 0)

        {

          NewRx (p, tcpHeader, fromAddress);

        }

      States_t saveState = m_state; // Used to see if app responds

      NS_LOG_LOGIC ("TcpSocket " << this 

          << " peer close, state " << m_state);

      if (!m_closeRequestNotified)

        {

          NS_LOG_LOGIC ("TCP " << this 

              << " calling AppCloseRequest");

          NotifyHalfClose ();

          m_closeRequestNotified = true;

        }

      NS_LOG_LOGIC ("TcpSocket " << this 

          << " peer close, state after " << m_state);

      if (m_state == saveState)

        { // Need to ack, the application will close later

          SendEmptyPacket (TcpHeader::ACK);

              // Also need to re-tx the ack if we

        }

      if (m_state == LAST_ACK)

        {

          NS_LOG_LOGIC ("TcpSocket " << this << " scheduling LATO1");

          m_lastAckEvent = Simulator::Schedule (m_rtt->RetransmitTimeout (),

                                                &TcpSocket::LastAckTimeout,this);

        }

      break;

    }

    case SERV_NOTIFY:

      NS_LOG_LOGIC ("TcpSocket " << this <<" Action SERV_NOTIFY");

      NS_LOG_LOGIC ("TcpSocket " << this << " Connected!");

      NotifyNewConnectionCreated (this, fromAddress);

      m_connected = true; // ! This is bogus; fix when we clone the tcp

      m_endPoint->SetPeer (m_remoteAddress, m_remotePort);

      //treat the connection orientation final ack as a newack

      CommonNewAck (tcpHeader.GetAckNumber (), true);

      break;

    default:

      break;

  }

  return true;

}

void TcpSocket::CompleteFork(Ptr<Packet> p, const TcpHeader& h, const Address& fromAddress)

{

  // Get port and address from peer (connecting host)

  m_remotePort = InetSocketAddress::ConvertFrom (fromAddress).GetPort ();

  m_remoteAddress = InetSocketAddress::ConvertFrom (fromAddress).GetIpv4 ();

  m_endPoint = m_tcp->Allocate (m_localAddress,

                                m_localPort,

                                m_remoteAddress,

                                m_remotePort);

  //the cloned socket with be in listen state, so manually change state

  m_state = SYN_RCVD;

  //equivalent to FinishBind

  m_endPoint->SetRxCallback (MakeCallback (&TcpSocket::ForwardUp, Ptr<TcpSocket>(this)));

  m_endPoint->SetDestroyCallback (MakeCallback (&TcpSocket::Destroy, Ptr<TcpSocket>(this)));

  ProcessPacketAction(SYN_ACK_TX, p, h, fromAddress);

 }

void TcpSocket::ConnectionSucceeded()

{ // We would preferred to have scheduled an event directly to

  // NotifyConnectionSucceeded, but (sigh) these are protected

  // and we can get the address of it :(

  NotifyConnectionSucceeded();

}

bool TcpSocket::SendPendingData (bool withAck)

{

  NS_LOG_FUNCTION;

  NS_LOG_PARAMS (this << withAck);

  NS_LOG_LOGIC ("ENTERING SendPendingData");

  if (!m_pendingData)

    {

      return false; // No data exists

    }

  uint32_t nPacketsSent = 0;

  while (m_pendingData->SizeFromSeq (m_firstPendingSequence, m_nextTxSequence))

    {

      uint32_t w = AvailableWindow ();// Get available window size

      NS_LOG_LOGIC ("TcpSocket " << this << " SendPendingData"

           << " w " << w 

           << " rxwin " << m_rxWindowSize

           << " cWnd " << m_cWnd

           << " segsize " << m_segmentSize

           << " nextTxSeq " << m_nextTxSequence

           << " highestRxAck " << m_highestRxAck 

           << " pd->Size " << m_pendingData->Size ()

           << " pd->SFS " << m_pendingData->SizeFromSeq (m_firstPendingSequence, m_nextTxSequence));

      if (w < m_segmentSize && m_pendingData->Size () > w)

        {

          break; // No more

        }

      uint32_t s = std::min (w, m_segmentSize);  // Send no more than window

      Ptr<Packet> p = m_pendingData->CopyFromSeq (s, m_firstPendingSequence, 

        m_nextTxSequence);

      NS_LOG_LOGIC("TcpSocket " << this << " sendPendingData"

                   << " txseq " << m_nextTxSequence

                   << " s " << s 

                   << " datasize " << p->GetSize() );

      uint8_t flags = 0;

      if (withAck)

        {

          flags |= TcpHeader::ACK;

        }

      uint32_t sz = p->GetSize (); // Size of packet

      uint32_t remainingData = m_pendingData->SizeFromSeq(

          m_firstPendingSequence,

          m_nextTxSequence + SequenceNumber (sz));

      if (m_closeOnEmpty && (remainingData == 0))

        {

          flags = TcpHeader::FIN;

          m_state = FIN_WAIT_1;

        }

      TcpHeader header;

      header.SetFlags (flags);

      header.SetSequenceNumber (m_nextTxSequence);

      header.SetAckNumber (m_nextRxSequence);

      header.SetSourcePort (m_endPoint->GetLocalPort());

      header.SetDestinationPort (m_remotePort);

      if (m_shutdownSend)

        {

          m_errno = ERROR_SHUTDOWN;

          return -1;

        }

      Time rto = m_rtt->RetransmitTimeout ();

      if (m_retxEvent.IsExpired () ) //go ahead and schedule the retransmit

        {

          NS_LOG_LOGIC ("Schedule retransmission timeout at time " << 

              Simulator::Now ().GetSeconds () << " to expire at time " <<

              (Simulator::Now () + rto).GetSeconds () );

          m_retxEvent = Simulator::Schedule (rto,&TcpSocket::ReTxTimeout,this);

        }

      NS_LOG_LOGIC ("About to send a packet with flags: " << flags);

      m_tcp->SendPacket (p, header,

                         m_endPoint->GetLocalAddress (),

                         m_remoteAddress);

      m_rtt->SentSeq(m_nextTxSequence, sz);       // notify the RTT

      // Notify the application

      Simulator::ScheduleNow(&TcpSocket::NotifyDataSent, this, p->GetSize ());

      nPacketsSent++;                             // Count sent this loop

      m_nextTxSequence += sz;                     // Advance next tx sequence

      // Note the high water mark

      m_highTxMark = std::max (m_nextTxSequence, m_highTxMark);

    }

  NS_LOG_LOGIC ("Sent "<<nPacketsSent<<" packets");

  NS_LOG_LOGIC("RETURN SendPendingData");

  return (nPacketsSent>0);

}

uint32_t  TcpSocket::UnAckDataCount ()

{

  NS_LOG_FUNCTION;

  return m_nextTxSequence - m_highestRxAck;

}

uint32_t  TcpSocket::BytesInFlight ()

{

  NS_LOG_FUNCTION;

  return m_highTxMark - m_highestRxAck;

}

uint32_t  TcpSocket::Window ()

{

  NS_LOG_FUNCTION;

  NS_LOG_LOGIC ("TcpSocket::Window() "<<this);

  return std::min (m_rxWindowSize, m_cWnd);

}

uint32_t  TcpSocket::AvailableWindow ()

{

  NS_LOG_FUNCTION;

  uint32_t unack = UnAckDataCount (); // Number of outstanding bytes

  uint32_t win = Window ();

  if (win < unack) 

    {

      return 0;  // No space available

    }

  return (win - unack);       // Amount of window space available

}

void TcpSocket::NewRx (Ptr<Packet> p,

                        const TcpHeader& tcpHeader, 

                        const Address& fromAddress)

{

  NS_LOG_FUNCTION;

  NS_LOG_PARAMS (this << p << "tcpHeader " << fromAddress);

  NS_LOG_LOGIC ("TcpSocket " << this << " NewRx,"

                << " seq " << tcpHeader.GetSequenceNumber()

                << " ack " << tcpHeader.GetAckNumber()

                << " p.size is " << p->GetSize () );

  NS_LOG_DEBUG ("TcpSocket " << this <<

                " NewRx," <<

                " seq " << tcpHeader.GetSequenceNumber() <<

                " ack " << tcpHeader.GetAckNumber() <<

                " p.size is " << p->GetSize());

  States_t origState = m_state;

  uint32_t s = p->GetSize ();  // Size of associated data

  if (s == 0)

    {// Nothing to do if no associated data

      return;

    }

  // Log sequence received if enabled

  // NoteTimeSeq(LOG_SEQ_RX, h->sequenceNumber);

  // Three possibilities

  // 1) Received seq is expected, deliver this and any buffered data

  // 2) Received seq is < expected, just re-ack previous

  // 3) Received seq is > expected, just re-ack previous and buffer data

  if (tcpHeader.GetSequenceNumber () == m_nextRxSequence)

    { // If seq is expected seq

      // 1) Update nextRxSeq

      // 2) Deliver to application this packet

      // 3) See if any buffered can be delivered

      // 4) Send the ack

      m_nextRxSequence += s;           // Advance next expected sequence

      //bytesReceived += s;       // Statistics

      NS_LOG_LOGIC("Case 1, advanced nrxs to " << m_nextRxSequence );

      NotifyDataReceived (p, fromAddress);

      if (m_closeNotified)

        {

          NS_LOG_LOGIC ("Tcp " << this << " HuH?  Got data after closeNotif");

        }

      NS_LOG_LOGIC ("TcpSocket " << this << " adv rxseq by " << s);

      // Look for buffered data

      UnAckData_t::iterator i;

      // Note that the bufferedData list DOES contain the tcp header

      while (!m_bufferedData.empty ())

        { // Check the buffered data for delivery

          NS_LOG_LOGIC("TCP " << this << " bufferedData.size() " 

              << m_bufferedData.size () 

              << " time " << Simulator::Now ());

          i = m_bufferedData.begin ();

          Ptr<Packet> p1 = i->second;

          SequenceNumber s1 = 0;

          if (i->first > m_nextRxSequence) 

            {

              break;  // Not next expected

            }

          // already have the header as a param

          //TCPHeader* h = dynamic_cast<TCPHeader*>(p1->PopPDU());

          // Check non-null here...

          uint8_t flags = tcpHeader.GetFlags ();           // Flags (used below)

          if (i->first < m_nextRxSequence)

            { // remove already delivered data

              // Two cases here.

              // 1) seq + length <= nextRxSeq, just discard

              // 2) seq + length > nextRxSeq, can deliver partial

              s1 = p->GetSize ();

              if (i->first + s1 < m_nextRxSequence)

                { // Just remove from list

                  //bufferedData.erase(i);

                  p1 = 0; // Nothing to deliver

                }

              else

                { // Remove partial data to prepare for delivery

                  uint32_t dup = m_nextRxSequence - i->first;

                  i->second = p1->CreateFragment (0, p1->GetSize () - dup);

                  p1 = i->second;

                }

            }

          else

            { // At this point i->first must equal nextRxSeq

              if (i->first != m_nextRxSequence)

                {

                  NS_FATAL_ERROR ("HuH?  NexRx failure, first "