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

/*

 * Copyright (c) 2005 INRIA

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation;

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 *

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

 */

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

#include "ipv4-end-point.h"

#include "ns3/log.h"

namespace ns3 {

NS_LOG_COMPONENT_DEFINE ("Ipv4EndPointDemux");

Ipv4EndPointDemux::Ipv4EndPointDemux ()

  : m_ephemeral (49152), m_portLast (65535), m_portFirst (49152)

{

  NS_LOG_FUNCTION_NOARGS ();

}

Ipv4EndPointDemux::~Ipv4EndPointDemux ()

{

  NS_LOG_FUNCTION_NOARGS ();

  for (EndPointsI i = m_endPoints.begin (); i != m_endPoints.end (); i++) 

    {

      Ipv4EndPoint *endPoint = *i;

      delete endPoint;

    }

  m_endPoints.clear ();

}

bool

Ipv4EndPointDemux::LookupPortLocal (uint16_t port)

{

  NS_LOG_FUNCTION_NOARGS ();

  for (EndPointsI i = m_endPoints.begin (); i != m_endPoints.end (); i++) 

    {

      if ((*i)->GetLocalPort  () == port) 

        {

          return true;

        }

    }

  return false;

}

bool

Ipv4EndPointDemux::LookupLocal (Ipv4Address addr, uint16_t port)

{

  NS_LOG_FUNCTION_NOARGS ();

  for (EndPointsI i = m_endPoints.begin (); i != m_endPoints.end (); i++) 

    {

      if ((*i)->GetLocalPort () == port &&

          (*i)->GetLocalAddress () == addr) 

        {

          return true;

        }

    }

  return false;

}

Ipv4EndPoint *

Ipv4EndPointDemux::Allocate (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  uint16_t port = AllocateEphemeralPort ();

  if (port == 0) 

    {

      NS_LOG_WARN ("Ephemeral port allocation failed.");

      return 0;

    }

  Ipv4EndPoint *endPoint = new Ipv4EndPoint (Ipv4Address::GetAny (), port);

  m_endPoints.push_back (endPoint);

  NS_LOG_DEBUG ("Now have >>" << m_endPoints.size () << "<< endpoints.");

  return endPoint;

}

Ipv4EndPoint *

Ipv4EndPointDemux::Allocate (Ipv4Address address)

{

  NS_LOG_FUNCTION (this << address);

  uint16_t port = AllocateEphemeralPort ();

  if (port == 0) 

    {

      NS_LOG_WARN ("Ephemeral port allocation failed.");

      return 0;

    }

  Ipv4EndPoint *endPoint = new Ipv4EndPoint (address, port);

  m_endPoints.push_back (endPoint);

  NS_LOG_DEBUG ("Now have >>" << m_endPoints.size () << "<< endpoints.");

  return endPoint;

}

Ipv4EndPoint *

Ipv4EndPointDemux::Allocate (uint16_t port)

{

  NS_LOG_FUNCTION (this <<  port);

  return Allocate (Ipv4Address::GetAny (), port);

}

Ipv4EndPoint *

Ipv4EndPointDemux::Allocate (Ipv4Address address, uint16_t port)

{

  NS_LOG_FUNCTION (this << address << port);

  if (LookupLocal (address, port)) 

    {

      NS_LOG_WARN ("Duplicate address/port; failing.");

      return 0;

    }

  Ipv4EndPoint *endPoint = new Ipv4EndPoint (address, port);

  m_endPoints.push_back (endPoint);

  NS_LOG_DEBUG ("Now have >>" << m_endPoints.size () << "<< endpoints.");

  return endPoint;

}

Ipv4EndPoint *

Ipv4EndPointDemux::Allocate (Ipv4Address localAddress, uint16_t localPort,

                             Ipv4Address peerAddress, uint16_t peerPort)

{

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

  for (EndPointsI i = m_endPoints.begin (); i != m_endPoints.end (); i++) 

    {

      if ((*i)->GetLocalPort () == localPort &&

          (*i)->GetLocalAddress () == localAddress &&

          (*i)->GetPeerPort () == peerPort &&

          (*i)->GetPeerAddress () == peerAddress) 

        {

          NS_LOG_WARN ("No way we can allocate this end-point.");

          /* no way we can allocate this end-point. */

          return 0;

        }

    }

  Ipv4EndPoint *endPoint = new Ipv4EndPoint (localAddress, localPort);

  endPoint->SetPeer (peerAddress, peerPort);

  m_endPoints.push_back (endPoint);

  NS_LOG_DEBUG ("Now have >>" << m_endPoints.size () << "<< endpoints.");

  return endPoint;

}

void 

Ipv4EndPointDemux::DeAllocate (Ipv4EndPoint *endPoint)

{

  NS_LOG_FUNCTION_NOARGS ();

  for (EndPointsI i = m_endPoints.begin (); i != m_endPoints.end (); i++) 

    {

      if (*i == endPoint)

        {

          delete endPoint;

          m_endPoints.erase (i);

          break;

        }

    }

}

/*

 * return list of all available Endpoints

 */

Ipv4EndPointDemux::EndPoints

Ipv4EndPointDemux::GetAllEndPoints (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  EndPoints ret;

  for (EndPointsI i = m_endPoints.begin (); i != m_endPoints.end (); i++)

    {

      Ipv4EndPoint* endP = *i;

      ret.push_back (endP);

    }

  return ret;

}

/*

 * If we have an exact match, we return it.

 * Otherwise, if we find a generic match, we return it.

 * Otherwise, we return 0.

 */

Ipv4EndPointDemux::EndPoints

Ipv4EndPointDemux::Lookup (Ipv4Address daddr, uint16_t dport, 

                           Ipv4Address saddr, uint16_t sport,

                           Ptr<Ipv4Interface> incomingInterface)

{

  NS_LOG_FUNCTION_NOARGS ();

  EndPoints retval1; // Matches exact on local port, wildcards on others

  EndPoints retval2; // Matches exact on local port/adder, wildcards on others

  EndPoints retval3; // Matches all but local address

  EndPoints retval4; // Exact match on all 4

  NS_LOG_FUNCTION (this << daddr << dport << saddr << sport << incomingInterface);

  NS_LOG_DEBUG ("Looking up endpoint for destination address " << daddr);

  for (EndPointsI i = m_endPoints.begin (); i != m_endPoints.end (); i++) 

    {

      Ipv4EndPoint* endP = *i;

      NS_LOG_DEBUG ("Looking at endpoint dport=" << endP->GetLocalPort ()

                                                 << " daddr=" << endP->GetLocalAddress ()

                                                 << " sport=" << endP->GetPeerPort ()

                                                 << " saddr=" << endP->GetPeerAddress ());

      if (endP->GetLocalPort () != dport) 

        {

          NS_LOG_LOGIC ("Skipping endpoint " << &endP

                                             << " because endpoint dport "

                                             << endP->GetLocalPort ()

                                             << " does not match packet dport " << dport);

          continue;

        }

      if (endP->GetBoundNetDevice ())

        {

          if (endP->GetBoundNetDevice () != incomingInterface->GetDevice ())

            {

              NS_LOG_LOGIC ("Skipping endpoint " << &endP

                                                 << " because endpoint is bound to specific device and"

                                                 << endP->GetBoundNetDevice ()

                                                 << " does not match packet device " << incomingInterface->GetDevice ());

              continue;

            }

        }

      bool subnetDirected = false;

      Ipv4Address incomingInterfaceAddr = daddr;  // may be a broadcast

      for (uint32_t i = 0; i < incomingInterface->GetNAddresses (); i++)

        {

          Ipv4InterfaceAddress addr = incomingInterface->GetAddress (i);

          if (addr.GetLocal ().CombineMask (addr.GetMask ()) == daddr.CombineMask (addr.GetMask ()) &&

              daddr.IsSubnetDirectedBroadcast (addr.GetMask ()))

            {

              subnetDirected = true;

              incomingInterfaceAddr = addr.GetLocal ();

            }

        }

      bool isBroadcast = (daddr.IsBroadcast () || subnetDirected == true);

      NS_LOG_DEBUG ("dest addr " << daddr << " broadcast? " << isBroadcast);

      bool localAddressMatchesWildCard = 

        endP->GetLocalAddress () == Ipv4Address::GetAny ();

      bool localAddressMatchesExact = endP->GetLocalAddress () == daddr;

      if (isBroadcast)

        {

          NS_LOG_DEBUG ("Found bcast, localaddr " << endP->GetLocalAddress ());

        }

      if (isBroadcast && (endP->GetLocalAddress () != Ipv4Address::GetAny ()))

        {

          localAddressMatchesExact = (endP->GetLocalAddress () ==

                                      incomingInterfaceAddr);

        }

      // if no match here, keep looking

      if (!(localAddressMatchesExact || localAddressMatchesWildCard))

        continue; 

      bool remotePeerMatchesExact = endP->GetPeerPort () == sport;

      bool remotePeerMatchesWildCard = endP->GetPeerPort () == 0;

      bool remoteAddressMatchesExact = endP->GetPeerAddress () == saddr;

      bool remoteAddressMatchesWildCard = endP->GetPeerAddress () ==

        Ipv4Address::GetAny ();

      // If remote does not match either with exact or wildcard,

      // skip this one

      if (!(remotePeerMatchesExact || remotePeerMatchesWildCard))

        continue;

      if (!(remoteAddressMatchesExact || remoteAddressMatchesWildCard))

        continue;

      // Now figure out which return list to add this one to

      if (localAddressMatchesWildCard &&

          remotePeerMatchesWildCard &&

          remoteAddressMatchesWildCard)

        { // Only local port matches exactly

          retval1.push_back (endP);

        }

      if ((localAddressMatchesExact || (isBroadcast && localAddressMatchesWildCard))&&

          remotePeerMatchesWildCard &&

          remoteAddressMatchesWildCard)

        { // Only local port and local address matches exactly

          retval2.push_back (endP);

        }

      if (localAddressMatchesWildCard &&

          remotePeerMatchesExact &&

          remoteAddressMatchesExact)

        { // All but local address

          retval3.push_back (endP);

        }

      if (localAddressMatchesExact &&

          remotePeerMatchesExact &&

          remoteAddressMatchesExact)

        { // All 4 match

          retval4.push_back (endP);

        }

    }

  // Here we find the most exact match

  if (!retval4.empty ()) return retval4;

  if (!retval3.empty ()) return retval3;

  if (!retval2.empty ()) return retval2;

  return retval1;  // might be empty if no matches

}

Ipv4EndPoint *

Ipv4EndPointDemux::SimpleLookup (Ipv4Address daddr, 

                                 uint16_t dport, 

                                 Ipv4Address saddr, 

                                 uint16_t sport)

{

  // this code is a copy/paste version of an old BSD ip stack lookup

  // function.

  uint32_t genericity = 3;

  Ipv4EndPoint *generic = 0;

  for (EndPointsI i = m_endPoints.begin (); i != m_endPoints.end (); i++) 

    {

      if ((*i)->GetLocalPort () != dport) 

        {

          continue;

        }

      if ((*i)->GetLocalAddress () == daddr &&

          (*i)->GetPeerPort () == sport &&

          (*i)->GetPeerAddress () == saddr) 

        {

          /* this is an exact match. */

          return *i;

        }

      uint32_t tmp = 0;

      if ((*i)->GetLocalAddress () == Ipv4Address::GetAny ()) 

        {

          tmp++;

        }

      if ((*i)->GetPeerAddress () == Ipv4Address::GetAny ()) 

        {

          tmp++;

        }

      if (tmp < genericity) 

        {

          generic = (*i);

          genericity = tmp;

        }

    }

  return generic;

}

uint16_t

Ipv4EndPointDemux::AllocateEphemeralPort (void)

{

  // Similar to counting up logic in netinet/in_pcb.c

  NS_LOG_FUNCTION_NOARGS ();

  uint16_t port = m_ephemeral;

  int count = m_portLast - m_portFirst;

  do 

    {

      if (count-- < 0)

        {

          return 0;

        }

      ++port;

      if (port < m_portFirst || port > m_portLast)

        {

          port = m_portFirst;

        }

    } while (LookupPortLocal (port));

  m_ephemeral = port;

  return port;

}

} // namespace ns3