/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2009 University of Washington
 *
 * 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
 *
 */

#include "ns3/log.h"
#include "ns3/ipv6.h"
#include "ns3/ipv6-route.h"
#include "ns3/node.h"
#include "ns3/ipv6-static-routing.h"
#include "ipv6-list-routing.h"
#include "ns3/simulator.h"

namespace ns3 {

NS_LOG_COMPONENT_DEFINE ("Ipv6ListRouting");

NS_OBJECT_ENSURE_REGISTERED (Ipv6ListRouting);

TypeId
Ipv6ListRouting::GetTypeId (void)
{
  static TypeId tid = TypeId ("ns3::Ipv6ListRouting")
    .SetParent<Ipv6RoutingProtocol> ()
    .AddConstructor<Ipv6ListRouting> ()
  ;
  return tid;
}


Ipv6ListRouting::Ipv6ListRouting ()
  : m_ipv6 (0)
{
  NS_LOG_FUNCTION_NOARGS ();
}

Ipv6ListRouting::~Ipv6ListRouting ()
{
  NS_LOG_FUNCTION_NOARGS ();
}

void
Ipv6ListRouting::DoDispose (void)
{
  NS_LOG_FUNCTION_NOARGS ();
  for (Ipv6RoutingProtocolList::iterator rprotoIter = m_routingProtocols.begin ();
       rprotoIter != m_routingProtocols.end (); rprotoIter++)
    {
      // Note:  Calling dispose on these protocols causes memory leak
      //        The routing protocols should not maintain a pointer to
      //        this object, so Dispose () shouldn't be necessary.
      (*rprotoIter).second = 0;
    }
  m_routingProtocols.clear ();
  m_ipv6 = 0;
}

Ptr<Ipv6Route>
Ipv6ListRouting::RouteOutput (Ptr<Packet> p, const Ipv6Header &header, Ptr<NetDevice> oif, enum Socket::SocketErrno &sockerr)
{
  NS_LOG_FUNCTION (this << header.GetDestinationAddress () << header.GetSourceAddress () << oif);
  Ptr<Ipv6Route> route;

  for (Ipv6RoutingProtocolList::const_iterator i = m_routingProtocols.begin ();
       i != m_routingProtocols.end (); i++)
    {
      NS_LOG_LOGIC ("Checking protocol " << (*i).second->GetInstanceTypeId () << " with priority " << (*i).first);
      NS_LOG_LOGIC ("Requesting source address for destination " << header.GetDestinationAddress ());
      route = (*i).second->RouteOutput (p, header, oif, sockerr);
      if (route)
        {
          NS_LOG_LOGIC ("Found route " << route);
          sockerr = Socket::ERROR_NOTERROR;
          return route;
        }
    }
  NS_LOG_LOGIC ("Done checking " << GetTypeId ());
  NS_LOG_LOGIC ("");
  sockerr = Socket::ERROR_NOROUTETOHOST;
  return 0;
}

// Patterned after Linux ip_route_input and ip_route_input_slow
bool
Ipv6ListRouting::RouteInput (Ptr<const Packet> p, const Ipv6Header &header, Ptr<const NetDevice> idev,
                             UnicastForwardCallback ucb, MulticastForwardCallback mcb,
                             LocalDeliverCallback lcb, ErrorCallback ecb)
{
  bool retVal = false;
  NS_LOG_FUNCTION (p << header << idev);
  NS_LOG_LOGIC ("RouteInput logic for node: " << m_ipv6->GetObject<Node> ()->GetId ());

  NS_ASSERT (m_ipv6 != 0);
  // Check if input device supports IP
  NS_ASSERT (m_ipv6->GetInterfaceForDevice (idev) >= 0);
  uint32_t iif = m_ipv6->GetInterfaceForDevice (idev);
  Ipv6Address dst = header.GetDestinationAddress ();

  // Multicast recognition; handle local delivery here
  //
  if (dst.IsMulticast ())
    {
#ifdef NOTYET
      if (m_ipv6->MulticastCheckGroup (iif, dst))
#endif
      if (true)
        {
          NS_LOG_LOGIC ("Multicast packet for me-- local deliver");
          Ptr<Packet> packetCopy = p->Copy ();
          // Here may want to disable lcb callback in recursive RouteInput
          // call below
          lcb (packetCopy, header, iif);
          // Fall through-- we may also need to forward this
          retVal = true;
        }

      /* do not forward link-local multicast address */
      if (dst.IsLinkLocalMulticast ())
        {
          return retVal;
        }

      for (Ipv6RoutingProtocolList::const_iterator rprotoIter =
             m_routingProtocols.begin (); rprotoIter != m_routingProtocols.end ();
           rprotoIter++)
        {
          NS_LOG_LOGIC ("Multicast packet for me-- trying to forward");
          if ((*rprotoIter).second->RouteInput (p, header, idev, ucb, mcb, lcb, ecb))
            {
              retVal = true;
            }
        }
      return retVal;
    }

  /// \todo  Configurable option to enable \RFC{1222} Strong End System Model
  // Right now, we will be permissive and allow a source to send us
  // a packet to one of our other interface addresses; that is, the
  // destination unicast address does not match one of the iif addresses,
  // but we check our other interfaces.  This could be an option
  // (to remove the outer loop immediately below and just check iif).
  for (uint32_t j = 0; j < m_ipv6->GetNInterfaces (); j++)
    {
      for (uint32_t i = 0; i < m_ipv6->GetNAddresses (j); i++)
        {
          Ipv6InterfaceAddress iaddr = m_ipv6->GetAddress (j, i);
          Ipv6Address addr = iaddr.GetAddress ();
          if (addr.IsEqual (header.GetDestinationAddress ()))
            {
              if (j == iif)
                {
                  NS_LOG_LOGIC ("For me (destination " << addr << " match)");
                }
              else
                {
                  NS_LOG_LOGIC ("For me (destination " << addr << " match) on another interface " << header.GetDestinationAddress ());
                }
              lcb (p, header, iif);
              return true;
            }
          NS_LOG_LOGIC ("Address " << addr << " not a match");
        }
    }
  // Check if input device supports IP forwarding
  if (m_ipv6->IsForwarding (iif) == false)
    {
      NS_LOG_LOGIC ("Forwarding disabled for this interface");
      ecb (p, header, Socket::ERROR_NOROUTETOHOST);
      return false;
    }
  // Next, try to find a route
  for (Ipv6RoutingProtocolList::const_iterator rprotoIter =
         m_routingProtocols.begin ();
       rprotoIter != m_routingProtocols.end ();
       rprotoIter++)
    {
      if ((*rprotoIter).second->RouteInput (p, header, idev, ucb, mcb, lcb, ecb))
        {
          return true;
        }
    }
  // No routing protocol has found a route.
  return retVal;
}

void
Ipv6ListRouting::NotifyInterfaceUp (uint32_t interface)
{
  NS_LOG_FUNCTION (this << interface);
  for (Ipv6RoutingProtocolList::const_iterator rprotoIter =
         m_routingProtocols.begin ();
       rprotoIter != m_routingProtocols.end ();
       rprotoIter++)
    {
      (*rprotoIter).second->NotifyInterfaceUp (interface);
    }
}
void
Ipv6ListRouting::NotifyInterfaceDown (uint32_t interface)
{
  NS_LOG_FUNCTION (this << interface);
  for (Ipv6RoutingProtocolList::const_iterator rprotoIter =
         m_routingProtocols.begin ();
       rprotoIter != m_routingProtocols.end ();
       rprotoIter++)
    {
      (*rprotoIter).second->NotifyInterfaceDown (interface);
    }
}
void
Ipv6ListRouting::NotifyAddAddress (uint32_t interface, Ipv6InterfaceAddress address)
{
  NS_LOG_FUNCTION (this << interface << address);
  for (Ipv6RoutingProtocolList::const_iterator rprotoIter =
         m_routingProtocols.begin ();
       rprotoIter != m_routingProtocols.end ();
       rprotoIter++)
    {
      (*rprotoIter).second->NotifyAddAddress (interface, address);
    }
}
void
Ipv6ListRouting::NotifyRemoveAddress (uint32_t interface, Ipv6InterfaceAddress address)
{
  NS_LOG_FUNCTION (this << interface << address);
  for (Ipv6RoutingProtocolList::const_iterator rprotoIter =
         m_routingProtocols.begin ();
       rprotoIter != m_routingProtocols.end ();
       rprotoIter++)
    {
      (*rprotoIter).second->NotifyRemoveAddress (interface, address);
    }
}

void Ipv6ListRouting::NotifyAddRoute (Ipv6Address dst, Ipv6Prefix mask, Ipv6Address nextHop, uint32_t interface, Ipv6Address prefixToUse)
{
  NS_LOG_FUNCTION (this << dst << mask << nextHop << interface);
  for (Ipv6RoutingProtocolList::const_iterator rprotoIter =
         m_routingProtocols.begin ();
       rprotoIter != m_routingProtocols.end ();
       rprotoIter++)
    {
      (*rprotoIter).second->NotifyAddRoute (dst, mask, nextHop, interface, prefixToUse);
    }
}

void Ipv6ListRouting::NotifyRemoveRoute (Ipv6Address dst, Ipv6Prefix mask, Ipv6Address nextHop, uint32_t interface, Ipv6Address prefixToUse)
{
  NS_LOG_FUNCTION (this << dst << mask << nextHop << interface);
  for (Ipv6RoutingProtocolList::const_iterator rprotoIter =
         m_routingProtocols.begin ();
       rprotoIter != m_routingProtocols.end ();
       rprotoIter++)
    {
      (*rprotoIter).second->NotifyRemoveRoute (dst, mask, nextHop, interface, prefixToUse);
    }
}

void
Ipv6ListRouting::PrintRoutingTable (Ptr<OutputStreamWrapper> stream) const
{
  NS_LOG_FUNCTION (this);

  *stream->GetStream () << "Node: " << m_ipv6->GetObject<Node> ()->GetId ()
                        << " Time: " << Simulator::Now ().GetSeconds () << "s "
                        << "Ipv6ListRouting table" << std::endl;
  for (Ipv6RoutingProtocolList::const_iterator i = m_routingProtocols.begin ();
       i != m_routingProtocols.end (); i++)
    {
      *stream->GetStream () << "  Priority: " << (*i).first << " Protocol: " << (*i).second->GetInstanceTypeId () << std::endl;
      (*i).second->PrintRoutingTable (stream);
    }
  *stream->GetStream () << std::endl;
}

void
Ipv6ListRouting::SetIpv6 (Ptr<Ipv6> ipv6)
{
  NS_LOG_FUNCTION (this << ipv6);
  NS_ASSERT (m_ipv6 == 0);
  for (Ipv6RoutingProtocolList::const_iterator rprotoIter =
         m_routingProtocols.begin ();
       rprotoIter != m_routingProtocols.end ();
       rprotoIter++)
    {
      (*rprotoIter).second->SetIpv6 (ipv6);
    }
  m_ipv6 = ipv6;
}

void
Ipv6ListRouting::AddRoutingProtocol (Ptr<Ipv6RoutingProtocol> routingProtocol, int16_t priority)
{
  NS_LOG_FUNCTION (this << routingProtocol->GetInstanceTypeId () << priority);
  m_routingProtocols.push_back (std::make_pair (priority, routingProtocol));
  m_routingProtocols.sort ( Compare );
  if (m_ipv6 != 0)
    {
      routingProtocol->SetIpv6 (m_ipv6);
    }
}

uint32_t
Ipv6ListRouting::GetNRoutingProtocols (void) const
{
  NS_LOG_FUNCTION (this);
  return m_routingProtocols.size ();
}

Ptr<Ipv6RoutingProtocol>
Ipv6ListRouting::GetRoutingProtocol (uint32_t index, int16_t& priority) const
{
  NS_LOG_FUNCTION (index);
  if (index > m_routingProtocols.size ())
    {
      NS_FATAL_ERROR ("Ipv6ListRouting::GetRoutingProtocol ():  index " << index << " out of range");
    }
  uint32_t i = 0;
  for (Ipv6RoutingProtocolList::const_iterator rprotoIter = m_routingProtocols.begin ();
       rprotoIter != m_routingProtocols.end (); rprotoIter++, i++)
    {
      if (i == index)
        {
          priority = (*rprotoIter).first;
          return (*rprotoIter).second;
        }
    }
  return 0;
}

bool
Ipv6ListRouting::Compare (const Ipv6RoutingProtocolEntry& a, const Ipv6RoutingProtocolEntry& b)
{
  return a.first > b.first;
}


} // namespace ns3