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

/*

 * Copyright (c) 2004 Francisco J. Ros 

 * Copyright (c) 2007 INESC Porto

 *

 * 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

 *

 * Authors: Francisco J. Ros  <fjrm@dif.um.es>

 *          Gustavo J. A. M. Carneiro <gjc@inescporto.pt>

 */

///

/// \file	OLSR_rtable.cc

/// \brief	Implementation of our routing table.

///

#include "routing-table.h"

#include "ns3/packet.h"

#include "ns3/ipv4-header.h"

#include "ns3/log.h"

namespace ns3 { namespace olsr {

NS_LOG_COMPONENT_DEFINE ("OlsrRoutingTable");

///

/// \brief Clears the routing table and frees the memory assigned to each one of its entries.

///

void

RoutingTable::Clear ()

{

  m_table.clear ();

}

///

/// \brief Deletes the entry whose destination address is given.

/// \param dest	address of the destination node.

///

void

RoutingTable::RemoveEntry (Ipv4Address const &dest)

{

  m_table.erase (dest);

}

///

/// \brief Looks up an entry for the specified destination address.

/// \param dest	destination address.

/// \param outEntry output parameter to hold the routing entry result, if fuond

/// \return	true if found, false if not found

///

bool

RoutingTable::Lookup (Ipv4Address const &dest,

                      RoutingTableEntry &outEntry) const

{

  // Get the iterator at "dest" position

  std::map<Ipv4Address, RoutingTableEntry>::const_iterator it =

    m_table.find (dest);

  // If there is no route to "dest", return NULL

  if (it == m_table.end ())

    return false;

  outEntry = it->second;

  return true;

}

///

/// \brief	Finds the appropiate entry which must be used in order to forward

///		a data packet to a next hop (given a destination).

///

/// Imagine a routing table like this: [A,B] [B,C] [C,C]; being each pair of the

/// form [dest addr,next-hop addr]. In this case, if this function is invoked with

/// [A,B] then pair [C,C] is returned because C is the next hop that must be used

/// to forward a data packet destined to A. That is, C is a neighbor of this node,

/// but B isn't. This function finds the appropiate neighbor for forwarding a packet.

///

/// \param entry	the routing table entry which indicates the destination node

///			we are interested in.

/// \return		the appropiate routing table entry which indicates the next

///			hop which must be used for forwarding a data packet, or NULL

///			if there is no such entry.

///

bool

RoutingTable::FindSendEntry (RoutingTableEntry const &entry,

                             RoutingTableEntry &outEntry) const

{

  outEntry = entry;

  while (outEntry.destAddr != outEntry.nextAddr)

    {

      if (not Lookup(outEntry.nextAddr, outEntry))

        return false;

    }

  return true;

}

bool

RoutingTable::RequestRoute (uint32_t ifIndex,

                            const Ipv4Header &ipHeader,

                            Ptr<Packet> packet,

                            RouteReplyCallback routeReply)

{

  RoutingTableEntry entry1, entry2;

  if (Lookup (ipHeader.GetDestination (), entry1))

    {

      bool foundSendEntry = FindSendEntry (entry1, entry2);

      if (!foundSendEntry)

        NS_FATAL_ERROR ("FindSendEntry failure");

      Ipv4Route route = Ipv4Route::CreateHostRouteTo

        (ipHeader.GetDestination (), entry2.nextAddr, entry2.interface);

      NS_LOG_DEBUG ("Olsr node" << m_mainAddress

                    << ": RouteRequest for dest=" << ipHeader.GetDestination ()

                    << " --> destHop=" << entry2.nextAddr

                    << " interface=" << entry2.interface);

      routeReply (true, route, packet, ipHeader);

      return true;

    }

  else

    {

      NS_LOG_DEBUG ("Olsr node" << m_mainAddress

                    << ": RouteRequest for dest=" << ipHeader.GetDestination ()

                    << " --> NOT FOUND");

      return false;

    }

}

bool

RoutingTable::RequestIfIndex (Ipv4Address destination,

                              uint32_t& ifIndex)

{

  RoutingTableEntry entry1, entry2;

  if (Lookup (destination, entry1))

    {

      bool foundSendEntry = FindSendEntry (entry1, entry2);

      if (!foundSendEntry)

        NS_FATAL_ERROR ("FindSendEntry failure");

      ifIndex = entry2.interface;

      return true;

    }

  else

    {

      return false;

    }

}

///

/// \brief Adds a new entry into the routing table.

///

/// If an entry for the given destination existed, it is deleted and freed.

///

/// \param dest		address of the destination node.

/// \param next		address of the next hop node.

/// \param iface	address of the local interface.

/// \param dist		distance to the destination node.

///

void

RoutingTable::AddEntry (Ipv4Address const &dest,

                        Ipv4Address const &next,

                        uint32_t interface,

                        uint32_t distance)

{

  // Creates a new rt entry with specified values

  RoutingTableEntry &entry = m_table[dest];

  entry.destAddr = dest;

  entry.nextAddr = next;

  entry.interface = interface;

  entry.distance = distance;

}

void

RoutingTable::AddEntry (Ipv4Address const &dest,

                        Ipv4Address const &next,

                        Ipv4Address const &interfaceAddress,

                        uint32_t distance)

{

  RoutingTableEntry entry;

  NS_ASSERT (m_ipv4);

  for (uint32_t i = 0; i < m_ipv4->GetNInterfaces (); i++)

    {

      if (m_ipv4->GetAddress (i) == interfaceAddress)

        {

          AddEntry (dest, next, i, distance);

          return;

        }

    }

  NS_ASSERT (false); // should not be reached

  AddEntry (dest, next, 0, distance);

}

///

/// \brief Returns the number of entries in the routing table.

/// \return the number of entries in the routing table.

///

// u_int32_t

// RoutingTable::size() {

// 	return rt_.size();

// }

}}; // namespace ns3, olsr

#ifdef RUN_SELF_TESTS

#include "ns3/test.h"

namespace ns3 { namespace olsr {

class OlsrRoutingTableTest : public ns3::Test {

private:

public:

  OlsrRoutingTableTest ();

  virtual bool RunTests (void);

};

OlsrRoutingTableTest::OlsrRoutingTableTest ()

  : ns3::Test ("OlsrRoutingTable")

{}

bool 

OlsrRoutingTableTest::RunTests (void)

{

  bool result = true;

  RoutingTable table;

  table.AddEntry (Ipv4Address ("1.2.3.5"),

                  Ipv4Address ("1.2.3.4"),

                  0,

                  1);

  table.AddEntry (Ipv4Address ("1.2.3.4"),

                  Ipv4Address ("1.2.3.4"),

                  0,

                  1);

  RoutingTableEntry entry1;

  NS_TEST_ASSERT (table.Lookup (Ipv4Address ("1.2.3.5"), entry1));

  NS_TEST_ASSERT_EQUAL (entry1.destAddr, Ipv4Address ("1.2.3.5"));

  NS_TEST_ASSERT_EQUAL (entry1.nextAddr, Ipv4Address ("1.2.3.4"));

  NS_TEST_ASSERT_EQUAL (entry1.interface, 0);

  NS_TEST_ASSERT_EQUAL (entry1.distance, 1);

  RoutingTableEntry entry2;

  NS_TEST_ASSERT (table.Lookup (Ipv4Address ("1.2.3.4"), entry2));

  NS_TEST_ASSERT_EQUAL (entry2.destAddr, Ipv4Address ("1.2.3.4"));

  NS_TEST_ASSERT_EQUAL (entry2.nextAddr, Ipv4Address ("1.2.3.4"));

  NS_TEST_ASSERT_EQUAL (entry2.interface, 0);

  NS_TEST_ASSERT_EQUAL (entry2.distance, 1);

  RoutingTableEntry sendEntry;

  NS_TEST_ASSERT (table.FindSendEntry (entry1, sendEntry));

  NS_TEST_ASSERT_EQUAL (sendEntry.destAddr, Ipv4Address ("1.2.3.4"));

  NS_TEST_ASSERT_EQUAL (sendEntry.nextAddr, Ipv4Address ("1.2.3.4"));

  NS_TEST_ASSERT_EQUAL (sendEntry.interface, 0);

  NS_TEST_ASSERT_EQUAL (sendEntry.distance, 1);

  table.RemoveEntry (Ipv4Address ("1.2.3.5"));

  RoutingTableEntry removedEntry;

  NS_TEST_ASSERT (not table.Lookup (Ipv4Address ("1.2.3.5"), removedEntry));

  return result;

}

static OlsrRoutingTableTest gOlsrRoutingTableTest;

}}; // namespace

#endif /* RUN_SELF_TESTS */