ipv4-end-point-demux.cc

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/* -*- 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 "ipv4-interface-address.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 (this);
}

Ipv4EndPointDemux::~Ipv4EndPointDemux ()
{
  NS_LOG_FUNCTION (this);
  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 (this << port);
  for (EndPointsI i = m_endPoints.begin (); i != m_endPoints.end (); i++) 
    {
      if ((*i)->GetLocalPort  () == port) 
        {
          return true;
        }
    }
  return false;
}

bool
Ipv4EndPointDemux::LookupLocal (Ptr<NetDevice> boundNetDevice, Ipv4Address addr, uint16_t port)
{
  NS_LOG_FUNCTION (this << addr << port);
  for (EndPointsI i = m_endPoints.begin (); i != m_endPoints.end (); i++) 
    {
      if ((*i)->GetLocalPort () == port &&
          (*i)->GetLocalAddress () == addr &&
          (*i)->GetBoundNetDevice () == boundNetDevice)
        {
          return true;
        }
    }
  return false;
}

Ipv4EndPoint *
Ipv4EndPointDemux::Allocate (void)
{
  NS_LOG_FUNCTION (this);
  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 (Ptr<NetDevice> boundNetDevice, uint16_t port)
{
  NS_LOG_FUNCTION (this <<  port << boundNetDevice);

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

Ipv4EndPoint *
Ipv4EndPointDemux::Allocate (Ptr<NetDevice> boundNetDevice, Ipv4Address address, uint16_t port)
{
  NS_LOG_FUNCTION (this << address << port << boundNetDevice);
  if (LookupLocal (boundNetDevice, address, port) || LookupLocal (0, address, port))
    {
      NS_LOG_WARN ("Duplicated endpoint.");
      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 (Ptr<NetDevice> boundNetDevice,
                             Ipv4Address localAddress, uint16_t localPort,
                             Ipv4Address peerAddress, uint16_t peerPort)
{
  NS_LOG_FUNCTION (this << localAddress << localPort << peerAddress << peerPort << boundNetDevice);
  for (EndPointsI i = m_endPoints.begin (); i != m_endPoints.end (); i++) 
    {
      if ((*i)->GetLocalPort () == localPort &&
          (*i)->GetLocalAddress () == localAddress &&
          (*i)->GetPeerPort () == peerPort &&
          (*i)->GetPeerAddress () == peerAddress &&
          ((*i)->GetBoundNetDevice () == boundNetDevice || (*i)->GetBoundNetDevice () == 0))
        {
          NS_LOG_WARN ("Duplicated endpoint.");
          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 (this << endPoint);
  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 (this);
  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 (this << daddr << dport << saddr << sport << incomingInterface);
  
  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_DEBUG ("Looking up endpoint for destination address " << daddr << ":" << dport);
  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->IsRxEnabled ())
        {
          NS_LOG_LOGIC ("Skipping endpoint " << &endP
                        << " because endpoint can not receive packets");
          continue;
        }

      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 localAddressMatchesExact = false;
      bool localAddressIsAny = false;
      bool localAddressIsSubnetAny = false;

      // We have 3 cases:
      // 1) Exact local / destination address match
      // 2) Local endpoint bound to Any -> matches anything
      // 3) Local endpoint bound to x.y.z.0 -> matches Subnet-directed broadcast packet (e.g., x.y.z.255 in a /24 net) and direct destination match.

      if (endP->GetLocalAddress () == daddr)
        {
          // Case 1:
          localAddressMatchesExact = true;
        }
      else if (endP->GetLocalAddress () == Ipv4Address::GetAny ())
        {
          // Case 2:
          localAddressIsAny = true;
        }
      else
        {
          // Case 3:
          for (uint32_t i = 0; i < incomingInterface->GetNAddresses (); i++)
            {
              Ipv4InterfaceAddress addr = incomingInterface->GetAddress (i);

              Ipv4Address addrNetpart = addr.GetLocal ().CombineMask (addr.GetMask ());
              if (endP->GetLocalAddress () == addrNetpart)
                {
                  NS_LOG_LOGIC ("Endpoint is SubnetDirectedAny " << endP->GetLocalAddress () << "/" << addr.GetMask ().GetPrefixLength ());

                  Ipv4Address daddrNetPart = daddr.CombineMask (addr.GetMask ());
                  if (addrNetpart == daddrNetPart)
                    {
                      localAddressIsSubnetAny = true;
                    }
                }
            }

          // if no match here, keep looking
          if (!localAddressIsSubnetAny)
            continue;
        }

      bool remotePortMatchesExact = endP->GetPeerPort () == sport;
      bool remotePortMatchesWildCard = 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 (!(remotePortMatchesExact || remotePortMatchesWildCard))
        continue;
      if (!(remoteAddressMatchesExact || remoteAddressMatchesWildCard))
        continue;

      bool localAddressMatchesWildCard = localAddressIsAny || localAddressIsSubnetAny;

      if (localAddressMatchesExact && remoteAddressMatchesExact && remotePortMatchesExact)
        { // All 4 match - this is the case of an open TCP connection, for example.
          NS_LOG_LOGIC ("Found an endpoint for case 4, adding " << endP->GetLocalAddress () << ":" << endP->GetLocalPort ());
          retval4.push_back (endP);
        }
      if (localAddressMatchesWildCard && remoteAddressMatchesExact && remotePortMatchesExact)
        { // All but local address - no idea what this case could be.
          NS_LOG_LOGIC ("Found an endpoint for case 3, adding " << endP->GetLocalAddress () << ":" << endP->GetLocalPort ());
          retval3.push_back (endP);
        }
      if (localAddressMatchesExact && remoteAddressMatchesWildCard && remotePortMatchesWildCard)
        { // Only local port and local address matches exactly - Not yet opened connection
          NS_LOG_LOGIC ("Found an endpoint for case 2, adding " << endP->GetLocalAddress () << ":" << endP->GetLocalPort ());
          retval2.push_back (endP);
        }
      if (localAddressMatchesWildCard && remoteAddressMatchesWildCard && remotePortMatchesWildCard)
        { // Only local port matches exactly - Endpoint open to "any" connection
          NS_LOG_LOGIC ("Found an endpoint for case 1, adding " << endP->GetLocalAddress () << ":" << endP->GetLocalPort ());
          retval1.push_back (endP);
        }
    }

  // Here we find the most exact match
  EndPoints retval;
  if (!retval4.empty ()) retval = retval4;
  else if (!retval3.empty ()) retval = retval3;
  else if (!retval2.empty ()) retval = retval2;
  else retval = retval1;

  NS_ABORT_MSG_IF (retval.size () > 1, "Too many endpoints - perhaps you created too many sockets without binding them to different NetDevices.");
  return retval;  // might be empty if no matches
}

Ipv4EndPoint *
Ipv4EndPointDemux::SimpleLookup (Ipv4Address daddr, 
                                 uint16_t dport, 
                                 Ipv4Address saddr, 
                                 uint16_t sport)
{
  NS_LOG_FUNCTION (this << daddr << dport << saddr << 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 (this);
  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