/* -*- 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/assert.h"

#include "ns3/log.h"

#include "ns3/nstime.h"

#include "ns3/boolean.h"

#include "ns3/object-vector.h"

#include "ns3/packet.h"

#include "ns3/node.h"

#include "ns3/simulator.h"

#include "ns3/ipv4-route.h"

#include "ns3/ipv6-route.h"

#include "tcp-l4-protocol.h"

#include "tcp-header.h"

#include "ipv4-end-point-demux.h"

#include "ipv6-end-point-demux.h"

#include "ipv4-end-point.h"

#include "ipv6-end-point.h"

#include "ipv4-l3-protocol.h"

#include "ipv6-l3-protocol.h"

#include "ipv6-routing-protocol.h"

#include "tcp-socket-factory-impl.h"

#include "tcp-newreno.h"

#include "rtt-estimator.h"

#include <vector>

#include <sstream>

#include <iomanip>

NS_LOG_COMPONENT_DEFINE ("TcpL4Protocol");

namespace ns3 {

NS_OBJECT_ENSURE_REGISTERED (TcpL4Protocol);

//TcpL4Protocol stuff----------------------------------------------------------

#undef NS_LOG_APPEND_CONTEXT

#define NS_LOG_APPEND_CONTEXT                                   \

  if (m_node) { std::clog << Simulator::Now ().GetSeconds () << " [node " << m_node->GetId () << "] "; } 

/* see http://www.iana.org/assignments/protocol-numbers */

const uint8_t TcpL4Protocol::PROT_NUMBER = 6;

TypeId 

TcpL4Protocol::GetTypeId (void)

{

  static TypeId tid = TypeId ("ns3::TcpL4Protocol")

    .SetParent<IpL4Protocol> ()

    .AddConstructor<TcpL4Protocol> ()

    .AddAttribute ("RttEstimatorType",

                   "Type of RttEstimator objects.",

                   TypeIdValue (RttMeanDeviation::GetTypeId ()),

                   MakeTypeIdAccessor (&TcpL4Protocol::m_rttTypeId),

                   MakeTypeIdChecker ())

    .AddAttribute ("SocketType",

                   "Socket type of TCP objects.",

                   TypeIdValue (TcpNewReno::GetTypeId ()),

                   MakeTypeIdAccessor (&TcpL4Protocol::m_socketTypeId),

                   MakeTypeIdChecker ())

    .AddAttribute ("SocketList", "The list of sockets associated to this protocol.",

                   ObjectVectorValue (),

                   MakeObjectVectorAccessor (&TcpL4Protocol::m_sockets),

                   MakeObjectVectorChecker<TcpSocketBase> ())

  ;

  return tid;

}

TcpL4Protocol::TcpL4Protocol ()

  : m_endPoints (new Ipv4EndPointDemux ()), m_endPoints6 (new Ipv6EndPointDemux ())

{

  NS_LOG_FUNCTION_NOARGS ();

  NS_LOG_LOGIC ("Made a TcpL4Protocol "<<this);

}

TcpL4Protocol::~TcpL4Protocol ()

{

  NS_LOG_FUNCTION_NOARGS ();

}

void 

TcpL4Protocol::SetNode (Ptr<Node> node)

{

  m_node = node;

}

/* 

 * This method is called by AddAgregate and completes the aggregation

 * by setting the node in the TCP stack, link it to the ipv4 stack and 

 * adding TCP socket factory to the node.

 */

void

TcpL4Protocol::NotifyNewAggregate ()

{

  Ptr<Node> node = this->GetObject<Node> ();

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

  Ptr<Ipv6L3Protocol> ipv6 = node->GetObject<Ipv6L3Protocol> ();

  if (m_node == 0)

    {

      if ((node != 0) && (ipv4 != 0 || ipv6 != 0))

        {

          this->SetNode (node);

          Ptr<TcpSocketFactoryImpl> tcpFactory = CreateObject<TcpSocketFactoryImpl> ();

          tcpFactory->SetTcp (this);

          node->AggregateObject (tcpFactory);

        }

    }

  // We set at least one of our 2 down targets to the IPv4/IPv6 send

  // functions.  Since these functions have different prototypes, we

  // need to keep track of whether we are connected to an IPv4 or

  // IPv6 lower layer and call the appropriate one.

  if (ipv4 != 0 && m_downTarget.IsNull ())

    {

      ipv4->Insert(this);

      this->SetDownTarget(MakeCallback(&Ipv4::Send, ipv4));

    }

  if (ipv6 != 0 && m_downTarget6.IsNull ())

    {

      ipv6->Insert(this);

      this->SetDownTarget6(MakeCallback(&Ipv6L3Protocol::Send, ipv6));

    }

  Object::NotifyNewAggregate ();

}

int 

TcpL4Protocol::GetProtocolNumber (void) const

{

  return PROT_NUMBER;

}

void

TcpL4Protocol::DoDispose (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  m_sockets.clear ();

  if (m_endPoints != 0)

    {

      delete m_endPoints;

      m_endPoints = 0;

    }

  if (m_endPoints6 != 0)

    {

      delete m_endPoints6;

      m_endPoints6 = 0;

    }

  m_node = 0;

  m_downTarget.Nullify ();

  m_downTarget6.Nullify ();

  IpL4Protocol::DoDispose ();

}

Ptr<Socket>

TcpL4Protocol::CreateSocket (TypeId socketTypeId)

{

  NS_LOG_FUNCTION_NOARGS ();

  ObjectFactory rttFactory;

  ObjectFactory socketFactory;

  rttFactory.SetTypeId (m_rttTypeId);

  socketFactory.SetTypeId (socketTypeId);

  Ptr<RttEstimator> rtt = rttFactory.Create<RttEstimator> ();

  Ptr<TcpSocketBase> socket = socketFactory.Create<TcpSocketBase> ();

  socket->SetNode (m_node);

  socket->SetTcp (this);

  socket->SetRtt (rtt);

  m_sockets.push_back (socket);

  return socket;

}

Ptr<Socket>

TcpL4Protocol::CreateSocket (void)

{

  return CreateSocket (m_socketTypeId);

}

Ipv4EndPoint *

TcpL4Protocol::Allocate (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  return m_endPoints->Allocate ();

}

Ipv4EndPoint *

TcpL4Protocol::Allocate (Ipv4Address address)

{

  NS_LOG_FUNCTION (this << address);

  return m_endPoints->Allocate (address);

}

Ipv4EndPoint *

TcpL4Protocol::Allocate (uint16_t port)

{

  NS_LOG_FUNCTION (this << port);

  return m_endPoints->Allocate (port);

}

Ipv4EndPoint *

TcpL4Protocol::Allocate (Ipv4Address address, uint16_t port)

{

  NS_LOG_FUNCTION (this << address << port);

  return m_endPoints->Allocate (address, port);

}

Ipv4EndPoint *

TcpL4Protocol::Allocate (Ipv4Address localAddress, uint16_t localPort,

                         Ipv4Address peerAddress, uint16_t peerPort)

{

  NS_LOG_FUNCTION (this << localAddress << localPort << peerAddress << peerPort);

  return m_endPoints->Allocate (localAddress, localPort,

                                peerAddress, peerPort);

}

void 

TcpL4Protocol::DeAllocate (Ipv4EndPoint *endPoint)

{

  NS_LOG_FUNCTION (this << endPoint);

  m_endPoints->DeAllocate (endPoint);

}

Ipv6EndPoint *

TcpL4Protocol::Allocate6 (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  return m_endPoints6->Allocate ();

}

Ipv6EndPoint *

TcpL4Protocol::Allocate6 (Ipv6Address address)

{

  NS_LOG_FUNCTION (this << address);

  return m_endPoints6->Allocate (address);

}

Ipv6EndPoint *

TcpL4Protocol::Allocate6 (uint16_t port)

{

  NS_LOG_FUNCTION (this << port);

  return m_endPoints6->Allocate (port);

}

Ipv6EndPoint *

TcpL4Protocol::Allocate6 (Ipv6Address address, uint16_t port)

{

  NS_LOG_FUNCTION (this << address << port);

  return m_endPoints6->Allocate (address, port);

}

Ipv6EndPoint *

TcpL4Protocol::Allocate6 (Ipv6Address localAddress, uint16_t localPort,

                          Ipv6Address peerAddress, uint16_t peerPort)

{

  NS_LOG_FUNCTION (this << localAddress << localPort << peerAddress << peerPort);

  return m_endPoints6->Allocate (localAddress, localPort,

                                 peerAddress, peerPort);

}

void

TcpL4Protocol::DeAllocate (Ipv6EndPoint *endPoint)

{

  NS_LOG_FUNCTION (this << endPoint);

  m_endPoints6->DeAllocate (endPoint);

}

void 

TcpL4Protocol::ReceiveIcmp (Ipv4Address icmpSource, uint8_t icmpTtl,

                            uint8_t icmpType, uint8_t icmpCode, uint32_t icmpInfo,

                            Ipv4Address payloadSource,Ipv4Address payloadDestination,

                            const uint8_t payload[8])

{

  NS_LOG_FUNCTION (this << icmpSource << icmpTtl << icmpType << icmpCode << icmpInfo 

                        << payloadSource << payloadDestination);

  uint16_t src, dst;

  src = payload[0] << 8;

  src |= payload[1];

  dst = payload[2] << 8;

  dst |= payload[3];

  Ipv4EndPoint *endPoint = m_endPoints->SimpleLookup (payloadSource, src, payloadDestination, dst);

  if (endPoint != 0)

    {

      endPoint->ForwardIcmp (icmpSource, icmpTtl, icmpType, icmpCode, icmpInfo);

    }

  else

    {

      NS_LOG_DEBUG ("no endpoint found source=" << payloadSource <<

                    ", destination="<<payloadDestination<<

                    ", src=" << src << ", dst=" << dst);

    }

}

void 

TcpL4Protocol::ReceiveIcmp (Ipv6Address icmpSource, uint8_t icmpTtl,

                            uint8_t icmpType, uint8_t icmpCode, uint32_t icmpInfo,

                            Ipv6Address payloadSource,Ipv6Address payloadDestination,

                            const uint8_t payload[8])

{

  NS_LOG_FUNCTION (this << icmpSource << icmpTtl << icmpType << icmpCode << icmpInfo 

                        << payloadSource << payloadDestination);

  uint16_t src, dst;

  src = payload[0] << 8;

  src |= payload[1];

  dst = payload[2] << 8;

  dst |= payload[3];

  Ipv6EndPoint *endPoint = m_endPoints6->SimpleLookup (payloadSource, src, payloadDestination, dst);

  if (endPoint != 0)

    {

      endPoint->ForwardIcmp (icmpSource, icmpTtl, icmpType, icmpCode, icmpInfo);

    }

  else

    {

      NS_LOG_DEBUG ("no endpoint found source=" << payloadSource <<

                    ", destination="<<payloadDestination<<

                    ", src=" << src << ", dst=" << dst);

    }

}

enum IpL4Protocol::RxStatus

TcpL4Protocol::Receive (Ptr<Packet> packet,

                        Ipv4Header const &ipHeader,

                        Ptr<Ipv4Interface> incomingInterface)

{

  NS_LOG_FUNCTION (this << packet << ipHeader << incomingInterface);

  TcpHeader tcpHeader;

  if(Node::ChecksumEnabled ())

    {

      tcpHeader.EnableChecksums ();

      tcpHeader.InitializeChecksum (ipHeader.GetSource (), ipHeader.GetDestination (), PROT_NUMBER);

    }

  packet->PeekHeader (tcpHeader);

  NS_LOG_LOGIC ("TcpL4Protocol " << this

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

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

                                 << " flags "<< std::hex << (int)tcpHeader.GetFlags () << std::dec

                                 << " data size " << packet->GetSize ());

  if(!tcpHeader.IsChecksumOk ())

    {

      NS_LOG_INFO ("Bad checksum, dropping packet!");

      return IpL4Protocol::RX_CSUM_FAILED;

    }

  NS_LOG_LOGIC ("TcpL4Protocol "<<this<<" received a packet");

  Ipv4EndPointDemux::EndPoints endPoints =

    m_endPoints->Lookup (ipHeader.GetDestination (), tcpHeader.GetDestinationPort (),

                         ipHeader.GetSource (), tcpHeader.GetSourcePort (),incomingInterface);

  if (endPoints.empty ())

    {

      if (this->GetObject<Ipv6L3Protocol> () != 0)

        {

          NS_LOG_LOGIC ("  No Ipv4 endpoints matched on TcpL4Protocol, trying Ipv6 "<<this);

          Ptr<Ipv6Interface> fakeInterface;

          Ipv6Header ipv6Header;

          Ipv6Address src = Ipv6Address::MakeIpv4MappedAddress (ipHeader.GetSource ());

          Ipv6Address dst = Ipv6Address::MakeIpv4MappedAddress (ipHeader.GetDestination ());

          ipv6Header.SetSourceAddress (src);

          ipv6Header.SetDestinationAddress (dst);

          return (this->Receive (packet, ipv6Header, fakeInterface));

        }

      NS_LOG_LOGIC ("  No endpoints matched on TcpL4Protocol "<<this);

      std::ostringstream oss;

      oss<<"  destination IP: ";

      ipHeader.GetDestination ().Print (oss);

      oss<<" destination port: "<< tcpHeader.GetDestinationPort ()<<" source IP: ";

      ipHeader.GetSource ().Print (oss);

      oss<<" source port: "<<tcpHeader.GetSourcePort ();

      NS_LOG_LOGIC (oss.str ());

      if (!(tcpHeader.GetFlags () & TcpHeader::RST))

        {

          // build a RST packet and send

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

          TcpHeader header;

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

            {

              // ACK bit was set

              header.SetFlags (TcpHeader::RST);

              header.SetSequenceNumber (header.GetAckNumber ());

            }

          else

            {

              header.SetFlags (TcpHeader::RST | TcpHeader::ACK);

              header.SetSequenceNumber (SequenceNumber32 (0));

              header.SetAckNumber (header.GetSequenceNumber () + SequenceNumber32 (1));

            }

          header.SetSourcePort (tcpHeader.GetDestinationPort ());

          header.SetDestinationPort (tcpHeader.GetSourcePort ());

          SendPacket (rstPacket, header, ipHeader.GetDestination (), ipHeader.GetSource ());

          return IpL4Protocol::RX_ENDPOINT_CLOSED;

        }

      else

        {

          return IpL4Protocol::RX_ENDPOINT_CLOSED;

        }

    }

  NS_ASSERT_MSG (endPoints.size () == 1, "Demux returned more than one endpoint");

  NS_LOG_LOGIC ("TcpL4Protocol "<<this<<" forwarding up to endpoint/socket");

  (*endPoints.begin ())->ForwardUp (packet, ipHeader, tcpHeader.GetSourcePort (), 

                                    incomingInterface);

  return IpL4Protocol::RX_OK;

}

enum IpL4Protocol::RxStatus

TcpL4Protocol::Receive (Ptr<Packet> packet,

                        Ipv6Header const &ipHeader,

                        Ptr<Ipv6Interface> interface)

{

  NS_LOG_FUNCTION (this << packet << ipHeader.GetSourceAddress () << ipHeader.GetDestinationAddress ());

  TcpHeader tcpHeader;

  // If we are receving a v4-mapped packet, we will re-calculate the TCP checksum

  // Is it worth checking every received "v6" packet to see if it is v4-mapped in

  // order to avoid re-calculating TCP checksums for v4-mapped packets?

  if(Node::ChecksumEnabled ())

    {

      tcpHeader.EnableChecksums ();

      tcpHeader.InitializeChecksum (ipHeader.GetSourceAddress (), ipHeader.GetDestinationAddress (), PROT_NUMBER);

    }

  packet->PeekHeader (tcpHeader);

  NS_LOG_LOGIC ("TcpL4Protocol " << this

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

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

                                 << " flags "<< std::hex << (int)tcpHeader.GetFlags () << std::dec

                                 << " data size " << packet->GetSize ());

  if(!tcpHeader.IsChecksumOk ())

    {

      NS_LOG_INFO ("Bad checksum, dropping packet!");

      return IpL4Protocol::RX_CSUM_FAILED;

    }

  NS_LOG_LOGIC ("TcpL4Protocol "<<this<<" received a packet");

  Ipv6EndPointDemux::EndPoints endPoints =

    m_endPoints6->Lookup (ipHeader.GetDestinationAddress (), tcpHeader.GetDestinationPort (),

                          ipHeader.GetSourceAddress (), tcpHeader.GetSourcePort (),interface);

  if (endPoints.empty ())

    {

      NS_LOG_LOGIC ("  No IPv6 endpoints matched on TcpL4Protocol "<<this);

      std::ostringstream oss;

      oss<<"  destination IP: ";

      (ipHeader.GetDestinationAddress ()).Print (oss);

      oss<<" destination port: "<< tcpHeader.GetDestinationPort ()<<" source IP: ";

      (ipHeader.GetSourceAddress ()).Print (oss);

      oss<<" source port: "<<tcpHeader.GetSourcePort ();

      NS_LOG_LOGIC (oss.str ());

      if (!(tcpHeader.GetFlags () & TcpHeader::RST))

        {

          // build a RST packet and send

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

          TcpHeader header;

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

            {

              // ACK bit was set

              header.SetFlags (TcpHeader::RST);

              header.SetSequenceNumber (header.GetAckNumber ());

            }

          else

            {