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

//

// Copyright (c) 2006 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: George F. Riley<riley@ece.gatech.edu>

//

//

// Topology helper for ns3.

// George F. Riley, Georgia Tech, Spring 2007

#include "ns3/debug.h"

#include "ns3/assert.h"

#include "ns3/nstime.h"

#include "ns3/internet-node.h"

#include "ns3/ipv4-address.h"

#include "ns3/drop-tail.h"

#include "ns3/arp-ipv4-interface.h"

#include "ns3/ipv4.h"

#include "p2p-channel.h"

#include "p2p-net-device.h"

#include "p2p-topology.h"

#define nil 0

namespace ns3 {

PointToPointChannel *

PointToPointTopology::AddPointToPointLink(

  const DataRate& bps,

  const Time& delay)

{

  // Duplex link is assumed to be subnetted as a /30

  // May run this unnumbered in the future?

  Ipv4Mask netmask("255.255.255.252");

  return channel;

}

P2PChannel* Topology::AddDuplexLink(Node* n1, const IPAddr& ip1, 

                                    Node* n2, const IPAddr& ip2,

                                    const Rate& rate, const Time& delay)

{

  // First get the NetDeviceList capability from each node

  NetDeviceList* ndl1 = n1->GetNetDeviceList();

  NetDeviceList* ndl2 = n2->GetNetDeviceList();

  if (!ndl1 || !ndl2) return nil;  // Both ends must have NetDeviceList

  // Get the net devices

  P2PNetDevice* nd1 = ndl1->Add(P2PNetDevice(n1, rate, nil));

  P2PNetDevice* nd2 = ndl2->Add(P2PNetDevice(n1, rate, nd1->GetChannel()));

  // Not implemented yet.  Add appropriate layer 2 protocol for

  // the net devices.

  // Get the L3 proto for node 1 and configure it with this device

  L3Demux*    l3demux1 = n1->GetL3Demux();

  L3Protocol* l3proto1 = nil;

  // If the node 1 l3 demux exists, find the coresponding l3 protocol

  if (l3demux1) l3proto1 = l3demux1->Lookup(ip1.L3Proto());

  // If the l3 protocol exists, configure this net device.  Use a mask

  // of all ones, since there is only one device on the remote end

  // of this link

  if (l3proto1) l3proto1->AddNetDevice(nd1, ip1, ip1.GetMask(ip1.Size()*8));

  // Same for node 2

  L3Demux*    l3demux2 = n2->GetL3Demux();

  L3Protocol* l3proto2 = nil;

  // If the node 2 l3 demux exists, find the coresponding l3 protocol

  if (l3demux2) l3proto2 = l3demux2->Lookup(ip2.L3Proto());

  if (l3proto2) l3proto2->AddNetDevice(nd2, ip2, ip2.GetMask(ip2.Size()*8));

  return dynamic_cast<P2PChannel*>(nd1->GetChannel());  // Always succeeds

}

// Get the net device connecting node n1 to n2.  For topologies where

// there are possibly multiple devices connecting n1 and n2 (for example

// wireless with two devices on different channels) this will return

// the first one found.

NetDevice* Topology::GetNetDevice(Node* n1, Node* n2)

{

  // First get the NetDeviceList capability from node 1

  NetDeviceList* ndl1 = n1->GetNetDeviceList();

  if (!ndl1) return 0; // No devices, return nil

  // Get the list of devices

  const NetDeviceList::NetDevices_t& dlist = ndl1->GetAll();

  for (NetDeviceList::NetDevices_t::const_iterator i = dlist.Begin();

       i != dlist.End(); ++i)

    { // Check each device

      NetDevice* nd = *i; // next device

      Channel* c = nd->GetChannel();

      if (!c) continue; // No channel

      if (c->NodeIsPeer(n2)) return nd; // found it

    }

  return 0; // None found

}

// Get the channel connecting node n1 to node n2

Channel* Topology::GetChannel(Node* n1, Node* n2)

{

  NetDevice* nd = GetNetDevice(n1, n2);

  if (!nd) return 0; // No net device, so no channel

  return nd->GetChannel();

}

Queue* Topology::GetQueue(Node* n1, Node* n2)

{

  NetDevice* nd = GetNetDevice(n1, n2);

  if (!nd) return 0; // No net device, so in queue

  return nd->GetQueue();

}

Queue* Topology::SetQueue(Node* n1, Node* n2, const Queue& q)

{

  NetDevice* nd = GetNetDevice(n1, n2);

  if (!nd) return 0; // No net device, can't set queue

  // Add the specified queue to the netdevice

  return nd->SetQueue(q);

}

#endif

} // namespace ns3