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

/*

 * 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

 *

 * based on earlier integration work by Tom Henderson and Sam Jansen.

 * 2008 Florian Westphal <fw@strlen.de>

 */

#include "ns3/assert.h"

#include "ns3/log.h"

#include "ns3/nstime.h"

#include "ns3/packet.h"

#include "ns3/node.h"

#include "ns3/object-vector.h"

#include "tcp-header.h"

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

#include "ipv4-end-point.h"

#include "ipv4-l3-protocol.h"

#include "nsc-tcp-l4-protocol.h"

#include "nsc-sysctl.h"

#include "tcp-typedefs.h"

#include <vector>

#include <sstream>

#include <dlfcn.h>

#include <iomanip>

#include <netinet/in.h>

#include <arpa/inet.h>

NS_LOG_COMPONENT_DEFINE ("NscTcpL4Protocol");

namespace ns3 {

NS_OBJECT_ENSURE_REGISTERED (NscTcpL4Protocol);

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

const uint8_t NscTcpL4Protocol::PROT_NUMBER = 6;

ObjectFactory

NscTcpL4Protocol::GetDefaultRttEstimatorFactory (void)

{

  ObjectFactory factory;

  factory.SetTypeId (RttMeanDeviation::GetTypeId ());

  return factory;

}

TypeId 

NscTcpL4Protocol::GetTypeId (void)

{

  static TypeId tid = TypeId ("ns3::NscTcpL4Protocol")

    .SetParent<Ipv4L4Protocol> ()

    .AddAttribute ("RttEstimatorFactory",

                   "How RttEstimator objects are created.",

                   ObjectFactoryValue (GetDefaultRttEstimatorFactory ()),

                   MakeObjectFactoryAccessor (&NscTcpL4Protocol::m_rttFactory),

                   MakeObjectFactoryChecker ())

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

                   ObjectVectorValue (),

                   MakeObjectVectorAccessor (&NscTcpL4Protocol::m_sockets),

                   MakeObjectVectorChecker<NscTcpSocketImpl> ())

    ;

  return tid;

}

int external_rand()

{

    return 1; // TODO

}

NscTcpL4Protocol::NscTcpL4Protocol ()

  : m_endPoints (new Ipv4EndPointDemux ()),

    m_nscStack (0),

    m_softTimer (Timer::CANCEL_ON_DESTROY)

{

  m_dlopenHandle = NULL;

  NS_LOG_LOGIC("Made a NscTcpL4Protocol "<<this);

}

NscTcpL4Protocol::~NscTcpL4Protocol ()

{

  NS_LOG_FUNCTION (this);

  dlclose(m_dlopenHandle);

}

void

NscTcpL4Protocol::SetNscLibrary(const std::string &soname)

}

void 

NscTcpL4Protocol::SetNode (Ptr<Node> node)

{

  m_node = node;

  if (m_nscStack)

    { // stack has already been loaded...

      return;

    }

  NS_ASSERT(m_dlopenHandle);

  FCreateStack create = (FCreateStack)dlsym(m_dlopenHandle, "nsc_create_stack");

  NS_ASSERT(create);

  m_nscStack = create(this, this, external_rand);

  int hzval = m_nscStack->get_hz();

  NS_ASSERT(hzval > 0);

  m_softTimer.SetFunction (&NscTcpL4Protocol::SoftInterrupt, this);

  m_softTimer.SetDelay (MilliSeconds (1000/hzval));

  m_nscStack->init(hzval);

  // This enables stack and NSC debug messages

  // m_nscStack->set_diagnostic(1000);

  Ptr<Ns3NscStack> nscStack = Create<Ns3NscStack> ();

  nscStack->SetStack (m_nscStack);

  node->AggregateObject (nscStack);

  m_softTimer.Schedule ();

  // its likely no ns-3 interface exits at this point, so

  // we dealy adding the nsc interface until the start of the simulation.

  Simulator::ScheduleNow (&NscTcpL4Protocol::AddInterface, this);

}

int 

NscTcpL4Protocol::GetProtocolNumber (void) const

{

  return PROT_NUMBER;

}

int 

NscTcpL4Protocol::GetVersion (void) const

{

  return 2;

}

void

NscTcpL4Protocol::DoDispose (void)

{

  NS_LOG_FUNCTION (this);

  for (std::vector<Ptr<NscTcpSocketImpl> >::iterator i = m_sockets.begin (); i != m_sockets.end (); i++)

    {

      *i = 0;

    }

  m_sockets.clear ();

  if (m_endPoints != 0)

    {

      delete m_endPoints;

      m_endPoints = 0;

    }

  m_node = 0;

  Ipv4L4Protocol::DoDispose ();

}

Ptr<Socket>

NscTcpL4Protocol::CreateSocket (void)

{

  NS_LOG_FUNCTION (this);

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

  Ptr<NscTcpSocketImpl> socket = CreateObject<NscTcpSocketImpl> ();

  socket->SetNode (m_node);

  socket->SetTcp (this);

  socket->SetRtt (rtt);

  m_sockets.push_back (socket);

  return socket;

}

Ipv4EndPoint *

NscTcpL4Protocol::Allocate (void)

{

  NS_LOG_FUNCTION (this);

  return m_endPoints->Allocate ();

}

Ipv4EndPoint *

NscTcpL4Protocol::Allocate (Ipv4Address address)

{

  NS_LOG_FUNCTION (this << address);

  return m_endPoints->Allocate (address);

}

Ipv4EndPoint *

NscTcpL4Protocol::Allocate (uint16_t port)

{

  NS_LOG_FUNCTION (this << port);

  return m_endPoints->Allocate (port);

}

Ipv4EndPoint *

NscTcpL4Protocol::Allocate (Ipv4Address address, uint16_t port)

{

  NS_LOG_FUNCTION (this << address << port);

  return m_endPoints->Allocate (address, port);

}

Ipv4EndPoint *

NscTcpL4Protocol::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 

NscTcpL4Protocol::DeAllocate (Ipv4EndPoint *endPoint)

{

  NS_LOG_FUNCTION (this << endPoint);

  // NSC m_endPoints->DeAllocate (endPoint);

}

Ipv4L4Protocol::RxStatus

NscTcpL4Protocol::Receive (Ptr<Packet> packet,

             Ipv4Address const &source,

             Ipv4Address const &destination,

             Ptr<Ipv4Interface> incomingInterface)

{

  NS_LOG_FUNCTION (this << packet << source << destination << incomingInterface);

  Ipv4Header ipHeader;

  uint32_t packetSize = packet->GetSize();

  // The way things work at the moment, the IP header has been removed

  // by the ns-3 IPv4 processing code. However, the NSC stack expects

  // a complete IP packet, so we add the IP header back.

  // Since the original header is already gone, we create a new one

  // based on the information we have.

  ipHeader.SetSource (source);

  ipHeader.SetDestination (destination);

  ipHeader.SetProtocol (PROT_NUMBER);

  ipHeader.SetPayloadSize (packetSize);

  ipHeader.SetTtl (1);

  // all NSC stacks check the IP checksum

  ipHeader.EnableChecksum ();

  packet->AddHeader(ipHeader);

  packetSize = packet->GetSize();

  const uint8_t *data = const_cast<uint8_t *>(packet->PeekData());

  // deliver complete packet to the NSC network stack

  m_nscStack->if_receive_packet(0, data, packetSize);

  wakeup ();

  return Ipv4L4Protocol::RX_OK;

}

void NscTcpL4Protocol::SoftInterrupt (void)

{

  m_nscStack->timer_interrupt ();

  m_nscStack->increment_ticks ();

  m_softTimer.Schedule ();

}

void NscTcpL4Protocol::send_callback(const void* data, int datalen)

{

  Ptr<Packet> p;

  uint32_t ipv4Saddr, ipv4Daddr;

  NS_ASSERT(datalen > 20);

  // create packet, without IP header. The TCP header is not touched.

  // Not using the IP header makes integration easier, but it destroys

  // eg. ECN.

  const uint8_t *rawdata = reinterpret_cast<const uint8_t *>(data);

  rawdata += 20; // skip IP header. IP options aren't supported at this time.

  datalen -= 20;

  p = Create<Packet> (rawdata, datalen);

  // we need the real source/destination ipv4 addresses for Send ().

  const uint32_t *ipheader = reinterpret_cast<const uint32_t *>(data);

  ipv4Saddr = *(ipheader+3);

  ipv4Daddr = *(ipheader+4);

  Ipv4Address saddr(ntohl(ipv4Saddr));

  Ipv4Address daddr(ntohl(ipv4Daddr));

  Ptr<Ipv4L3Protocol> ipv4 = m_node->GetObject<Ipv4L3Protocol> ();

  NS_ASSERT_MSG (ipv4, "nsc callback invoked, but node has no ipv4 object");

  m_nscStack->if_send_finish(0);

}

void NscTcpL4Protocol::wakeup()

{

  // TODO

  // this should schedule a timer to read from all tcp sockets now... this is

  // an indication that data might be waiting on the socket

  Ipv4EndPointDemux::EndPoints endPoints = m_endPoints->GetAllEndPoints ();

  for (Ipv4EndPointDemux::EndPointsI endPoint = endPoints.begin ();

       endPoint != endPoints.end (); endPoint++) {

          // NSC HACK: (ab)use TcpSocket::ForwardUp for signalling

          (*endPoint)->ForwardUp (NULL, Ipv4Address(), 0);

  }

}

void NscTcpL4Protocol::gettime(unsigned int* sec, unsigned int* usec)

{

  // Only used by the Linux network stack, e.g. during ISN generation

  // and in the kernel rng initialization routine. Also used in Linux

  // printk output.

  Time t = Simulator::Now ();

  int64_t us = t.GetMicroSeconds ();

  *sec = us / (1000*1000);

  *usec = us - *sec * (1000*1000);

}

void NscTcpL4Protocol::AddInterface(void)

{

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

  const uint32_t nInterfaces = ip->GetNInterfaces ();

  NS_ASSERT_MSG (nInterfaces <= 2, "nsc does not support multiple interfaces per node");

  // start from 1, ignore the loopback interface (HACK)

  // we really don't need the loop, but its here to illustrate

  // how things _should_ be (once nsc can deal with multiple interfaces...)

  for (uint32_t i = 1; i < nInterfaces; i++)

    {

      Ipv4InterfaceAddress ifAddr = ip->GetAddress (i, 0);

      Ipv4Address addr = ifAddr.GetLocal ();

      Ipv4Mask mask = ifAddr.GetMask ();

      uint16_t mtu = ip->GetMtu (i);

      std::ostringstream addrOss, maskOss;

      addr.Print(addrOss);

      mask.Print(maskOss);

      NS_LOG_LOGIC ("if_attach " << addrOss.str().c_str() << " " << maskOss.str().c_str() << " " << mtu);

      std::string addrStr = addrOss.str();

      std::string maskStr = maskOss.str();

      const char* addrCStr = addrStr.c_str();

      const char* maskCStr = maskStr.c_str();

      m_nscStack->if_attach(addrCStr, maskCStr, mtu);

      if (i == 1)

      {

        // We need to come up with a default gateway here. Can't guarantee this to be

        // correct really...

        uint8_t addrBytes[4];

        addr.Serialize(addrBytes);

        // XXX: this is all a bit of a horrible hack

        //

        // Just increment the last octet, this gives a decent chance of this being

        // 'enough'.

        //

        // All we need is another address on the same network as the interface. This

        // will force the stack to output the packet out of the network interface.

        addrBytes[3]++;

        addr.Deserialize(addrBytes);

        addrOss.str("");

        addr.Print(addrOss);

        m_nscStack->add_default_gateway(addrOss.str().c_str());

      }

  }

}

}; // namespace ns3