/* -*-  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 " 

                       << i->first << " nextRxSeq " << m_nextRxSequence);

                 }

               s1 = p1->GetSize ();

             }

           NotifyDataReceived (p1, fromAddress);

           NS_LOG_LOGIC ("TcpSocket " << this << " adv rxseq1 by " << s1 );

           m_nextRxSequence += s1;           // Note data received

           m_bufferedData.erase (i);     // Remove from list

           if (flags & TcpHeader::FIN)

             NS_LOG_LOGIC("TcpSocket " << this 

                     << " found FIN in buffered");

         }

       if (m_pendingClose || (origState > ESTABLISHED))

         { // See if we can close now

           if (m_bufferedData.empty())

             {

               ProcessPacketAction (PEER_CLOSE, p, tcpHeader, fromAddress);

             }

         }

     }

   else if (SequenceNumber (tcpHeader.GetSequenceNumber ()) >= m_nextRxSequence)

     { // Need to buffer this one

       NS_LOG_LOGIC ("Case 2, buffering " << tcpHeader.GetSequenceNumber () );

       UnAckData_t::iterator i = 

         m_bufferedData.find (tcpHeader.GetSequenceNumber () );

       if (i != m_bufferedData.end () )

         {

           i->second = 0; // relase reference to already buffered

         }

       // Save for later delivery

       m_bufferedData[tcpHeader.GetSequenceNumber () ] = p;  

     }

   else

     { // debug

       NS_LOG_LOGIC("TCP " << this 

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

                << " expected " << m_nextRxSequence

                << "       flags " << tcpHeader.GetFlags ());

     }

   // Now send a new ack packet acknowledging all received and delivered data

   SendEmptyPacket (TcpHeader::ACK);

 }

 void TcpSocket::CommonNewAck (SequenceNumber ack, bool skipTimer)

 { // CommonNewAck is called only for "New" (non-duplicate) acks

   // and MUST be called by any subclass, from the NewAck function

   // Always cancel any pending re-tx timer on new acknowledgement

   NS_LOG_FUNCTION;

   NS_LOG_PARAMS (this << ack << skipTimer);

   //DEBUG(1,(cout << "TCP " << this << "Cancelling retx timer " << endl));

   if (!skipTimer)

     {

       m_retxEvent.Cancel ();

     }

   NS_LOG_LOGIC ("TCP " << this << " NewAck " << ack 

            << " numberAck " << (ack - m_highestRxAck)); // Number bytes ack'ed

   m_highestRxAck = ack;         // Note the highest recieved Ack

   if (ack > m_nextTxSequence) 

     {

       m_nextTxSequence = ack; // If advanced

     }

   // See if all pending ack'ed; if so we can delete the data

   if (m_pendingData)

     { // Data exists, see if can be deleted

       if (m_pendingData->SizeFromSeq (m_firstPendingSequence, m_highestRxAck) == 0)

         { // All pending acked, can be deleted

           m_pendingData->Clear ();

           delete m_pendingData;

           m_pendingData = 0;

           // Insure no re-tx timer

           m_retxEvent.Cancel ();

         }

     }

   // Try to send more data

   SendPendingData();

 }

 Ptr<TcpSocket> TcpSocket::Copy ()

 {

   return CopyObject<TcpSocket> (this);

 }

 void TcpSocket::NewAck (SequenceNumber seq)

 { // New acknowledgement up to sequence number "seq"

   // Adjust congestion window in response to new ack's received

   NS_LOG_FUNCTION;

   NS_LOG_PARAMS (this << seq);

   NS_LOG_LOGIC ("TcpSocket " << this << " NewAck "

            << " seq " << seq

            << " cWnd " << m_cWnd

            << " ssThresh " << m_ssThresh);

   if (m_cWnd < m_ssThresh)

     { // Slow start mode, add one segSize to cWnd

       m_cWnd += m_segmentSize;

       NS_LOG_LOGIC ("TcpSocket " << this << " NewCWnd SlowStart, cWnd " << m_cWnd 

           << " sst " << m_ssThresh);

     }

   else

     { // Congestion avoidance mode, adjust by (ackBytes*segSize) / cWnd

       double adder =  ((double) m_segmentSize * m_segmentSize) / m_cWnd;

       if (adder < 1.0) 

         {

           adder = 1.0;

         }

       m_cWnd += (uint32_t) adder;

       NS_LOG_LOGIC ("NewCWnd CongAvoid, cWnd " << m_cWnd 

            << " sst " << m_ssThresh);

     }

   CommonNewAck (seq, false);           // Complete newAck processing

 }

 void TcpSocket::DupAck (const TcpHeader& t, uint32_t count)

 {

   NS_LOG_FUNCTION;

   NS_LOG_PARAMS (this << "t " << count);

   NS_LOG_LOGIC ("TcpSocket " << this << " DupAck " <<  t.GetAckNumber ()

       << ", count " << count

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

   if (count == 3)

   { // Count of three indicates triple duplicate ack

     m_ssThresh = Window () / 2; // Per RFC2581

     m_ssThresh = std::max (m_ssThresh, 2 * m_segmentSize);

     NS_LOG_LOGIC("TcpSocket " << this << "Tahoe TDA, time " << Simulator::Now ()

         << " seq " << t.GetAckNumber ()

         << " in flight " << BytesInFlight ()

         << " new ssthresh " << m_ssThresh);

     m_cWnd = m_segmentSize; // Collapse cwnd (re-enter slowstart)

     // For Tahoe, we also reset nextTxSeq

     m_nextTxSequence = m_highestRxAck;

     SendPendingData ();

   }

 }

 void TcpSocket::ReTxTimeout ()

 { // Retransmit timeout

   NS_LOG_FUNCTION;

   NS_LOG_PARAMS (this);

   m_ssThresh = Window () / 2; // Per RFC2581

   m_ssThresh = std::max (m_ssThresh, 2 * m_segmentSize);

   // Set cWnd to segSize on timeout,  per rfc2581

   // Collapse congestion window (re-enter slowstart)

   m_cWnd = m_segmentSize;           

   m_nextTxSequence = m_highestRxAck; // Start from highest Ack

   m_rtt->IncreaseMultiplier (); // Double timeout value for next retx timer

   Retransmit ();             // Retransmit the packet

 }

 void TcpSocket::LastAckTimeout ()

 {

   m_lastAckEvent.Cancel ();

   if (m_state == LAST_ACK)

     {

       Actions_t action = ProcessEvent (TIMEOUT);

       ProcessAction (action);

     }

   if (!m_closeNotified)

     {

       m_closeNotified = true;

     }

 }

 void TcpSocket::Retransmit ()

 {

   NS_LOG_FUNCTION;

   NS_LOG_PARAMS (this);

   uint8_t flags = TcpHeader::NONE;

   if (m_state == SYN_SENT) 

     {

       if (m_cnCount > 0) 

         {

           SendEmptyPacket (TcpHeader::SYN);

           return;

         }

       else

         {

           NotifyConnectionFailed ();

           return;

         }

     } 

   if (!m_pendingData)

     {

       if (m_state == FIN_WAIT_1 || m_state == FIN_WAIT_2)

         { // Must have lost FIN, re-send

           SendEmptyPacket (TcpHeader::FIN);

         }

       return;

     }

   Ptr<Packet> p = m_pendingData->CopyFromSeq (m_segmentSize,

                                             m_firstPendingSequence,

                                             m_highestRxAck);

   // Calculate remaining data for COE check

   uint32_t remainingData = m_pendingData->SizeFromSeq (

       m_firstPendingSequence,

       m_nextTxSequence + SequenceNumber(p->GetSize ()));

   if (m_closeOnEmpty && remainingData == 0)

     { // Add the FIN flag

       flags = flags | TcpHeader::FIN;

     }

   NS_LOG_LOGIC ("TcpSocket " << this << " retxing seq " << m_highestRxAck);

   if (m_retxEvent.IsExpired () )

     {

       Time rto = m_rtt->RetransmitTimeout ();

       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);

     }

   m_rtt->SentSeq (m_highestRxAck,p->GetSize ());

   // And send the packet

   TcpHeader tcpHeader;

   tcpHeader.SetSequenceNumber (m_nextTxSequence);

   tcpHeader.SetAckNumber (m_nextRxSequence);

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

   tcpHeader.SetDestinationPort (m_remotePort);

   tcpHeader.SetFlags (flags);

   tcpHeader.SetWindowSize (m_advertisedWindowSize);

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

     m_remoteAddress);

 }

 }//namespace ns3