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

/*

 * Copyright (c) 2008 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>

 * Author: Faker Moatamri <faker.moatamri@sophia.inria.fr>

 */

/**

 * \ingroup internetStack

 * \defgroup internetStackModel Internet Stack Model

 *

 * \section internetStackTracingModel Tracing in the Internet Stack

 *

 * The internet stack provides a number of trace sources in its various

 * protocol implementations.  These trace sources can be hooked using your own 

 * custom trace code, or you can use our helper functions in some cases to 

 * arrange for tracing to be enabled.

 *

 * \subsection internetStackArpTracingModel Tracing in ARP

 *

 * ARP provides two trace hooks, one in the cache, and one in the layer three

 * protocol.  The trace accessor in the cache is given the name "Drop."  When

 * a packet is transmitted over an interface that requires ARP, it is first

 * queued for transmission in the ARP cache until the required MAC address is

 * resolved.  There are a number of retries that may be done trying to get the 

 * address, and if the maximum retry count is exceeded the packet in question 

 * is dropped by ARP.  The single trace hook in the ARP cache is called,

 *

 * - If an outbound packet is placed in the ARP cache pending address resolution

 *   and no resolution can be made within the maximum retry count, the outbound 

 *   packet is dropped and this trace is fired;

 *

 * A second trace hook lives in the ARP L3 protocol (also named "Drop") and may 

 * be called for a  number of reasons.

 *

 * - If an ARP reply is received for an entry that is not waiting for a reply,

 *   the ARP reply packet is dropped and this trace is fired;

 * - If an ARP reply is received for a non-existant entry, the ARP reply packet 

 *   is dropped and this trace is fired;

 * - If an ARP cache entry is in the DEAD state (has timed out) and an ARP reply

 *   packet is received, the reply packet is dropped and this trace is fired.

 * - Each ARP cache entry has a queue of pending packets.  If the size of the

 *   queue is exceeded, the outbound packet is dropped and this trace is fired.

 *

 * \subsection internetStackIpv4TracingModel Tracing in IPv4

 *

 * The IPv4 layer three protocol provides three trace hooks.  These are the 

 * "Tx" (ns3::Ipv4L3Protocol::m_txTrace), "Rx" (ns3::Ipv4L3Protocol::m_rxTrace) 

 * and "Drop" (ns3::Ipv4L3Protocol::m_dropTrace) trace sources.

 *

 * The "Tx" trace is fired in a number of situations, all of which indicate that

 * a given packet is about to be sent down to a given ns3::Ipv4Interface.

 *

 * - In the case of a packet destined for the broadcast address, the 

 *   Ipv4InterfaceList is iterated and for every interface that is up and can

 *   fragment the packet or has a large enough MTU to transmit the packet,

 *   the trace is hit.  See ns3::Ipv4L3Protocol::Send.

 *

 * - In the case of a packet that needs routing, the "Tx" trace may be fired

 *   just before a packet is sent to the interface appropriate to the default 

 *   gateway.  See ns3::Ipv4L3Protocol::SendRealOut.

 *

 * - Also in the case of a packet that needs routing, the "Tx" trace may be 

 *   fired just before a packet is sent to the outgoing interface appropriate

 *   to the discovered route.  See ns3::Ipv4L3Protocol::SendRealOut.

 *

 * The "Rx" trace is fired when a packet is passed from the device up to the

 * ns3::Ipv4L3Protocol::Receive function.

 *

 * - In the receive function, the Ipv4InterfaceList is iterated, and if the

 *   Ipv4Interface corresponding to the receiving device is fount to be in the

 *   UP state, the trace is fired.

 *

 * The "Drop" trace is fired in any case where the packet is dropped (in both

 * the transmit and receive paths).

 *

 * - In the ns3::Ipv4Interface::Receive function, the packet is dropped and the

 *   drop trace is hit if the interface corresponding to the receiving device

 *   is in the DOWN state.

 *

 * - Also in the ns3::Ipv4Interface::Receive function, the packet is dropped and

 *   the drop trace is hit if the checksum is found to be bad.

 *

 * - In ns3::Ipv4L3Protocol::Send, an outgoing packet bound for the broadcast

 *   address is dropped and the "Drop" trace is fired if the "don't fragement"

 *   bit is set and fragmentation is available and required.

 *

 * - Also in ns3::Ipv4L3Protocol::Send, an outgoing packet destined for the 

 *   broadcast address is dropped and the "Drop" trace is hit if fragmentation

 *   is not available and is required (MTU < packet size).

 *

 * - In the case of a broadcast address, an outgoing packet is cloned for each

 *   outgoing interface.  If any of the interfaces is in the DOWN state, the 

 *   "Drop" trace event fires with a reference to the copied packet.

 *

 * - In the case of a packet requiring a route, an outgoing packet is dropped

 *   and the "Drop" trace event fires if no route to the remote host is found.

 *

 * - In ns3::Ipv4L3Protocol::SendRealOut, an outgoing packet being routed

 *   is dropped and the "Drop" trace is fired if the "don't fragement" bit is 

 *   set and fragmentation is available and required.

 *

 * - Also in ns3::Ipv4L3Protocol::SendRealOut, an outgoing packet being routed

 *   is dropped and the "Drop" trace is hit if fragmentation is not available 

 *   and is required (MTU < packet size).

 *

 * - An outgoing packet being routed is dropped and the "Drop" trace event fires

 *   if the required Ipv4Interface is in the DOWN state.

 *

 * - If a packet is being forwarded, and the TTL is exceeded (see

 *   ns3::Ipv4L3Protocol::DoForward), the packet is dropped and the "Drop" trace 

 *   event is fired.

 *

 * \subsection internetStackNs3TCPTracingModel Tracing in ns-3 TCP

 *

 * There is currently one trace source in the ns-3 TCP implementation named

 * "CongestionWindow" (see ns3::TcpSocketImpl::m_cWnd).  This is set in a number

 * of places (see file tcp-socket-impl.cc) whenever the value of the congestion

 * window is changed.

 *

 * \subsection internetStackNscTCPTracingModel Tracing in NSC TCP

 *

 * There is currently one trace source in the Network Simulation Cradle TCP 

 * implementation named "CongestionWindow" (see ns3::NscTcpSocketImpl::m_cWnd).

 * This is set in a number of places (see file nsc-tcp-socket-impl.cc) when 

 * the value of the cogestion window is initially set.  Note that this is not

 * instrumented from the underlying TCP implementaion.

 *

 * \subsection internetStackNs3UdpTracingModel Tracing in ns-3 UDP

 *

 * There is currently one trace source in the ns-3 UDP implementation named

 * "Drop" (see ns3::UdpSocketImpl::m_dropTrace).  This is set when a packet

 * is received in ns3::UdpSocketImpl::ForwardUp and the receive buffer cannot

 * accomodate the encapsulated data.

 */

#include "ns3/assert.h"

#include "ns3/log.h"

#include "ns3/object.h"

#include "ns3/names.h"

#include "ns3/ipv4.h"

#include "ns3/ipv6.h"

#include "ns3/packet-socket-factory.h"

#include "ns3/config.h"

#include "ns3/simulator.h"

#include "ns3/string.h"

#include "ns3/net-device.h"

#include "ns3/callback.h"

#include "ns3/node.h"

#include "ns3/core-config.h"

#include "ns3/arp-l3-protocol.h"

#include "internet-stack-helper.h"

#include "ipv4-list-routing-helper.h"

#include "ipv4-static-routing-helper.h"

#include "ipv4-global-routing-helper.h"

#include "ipv6-list-routing-helper.h"

#include "ipv6-static-routing-helper.h"

#include "trace-helper.h"

#include <limits>

#include <map>

NS_LOG_COMPONENT_DEFINE ("InternetStackHelper");

namespace ns3 {

//

// Things are going to work differently here with respect to trace file handling

// than in most places because the Tx and Rx trace sources we are interested in

// are going to multiplex receive and transmit callbacks for all Ipv4 and 

// interface pairs through one callback.  We want packets to or from each 

// distinct pair to go to an individual file, so we have got to demultiplex the

// Ipv4 and interface pair into a corresponding Ptr<PcapFileObject> at the 

// callback.

//

// This has got to continue to work properly after the helper has been 

//

typedef std::pair<Ptr<Ipv6>, uint32_t> InterfacePairIpv6;

typedef std::map<InterfacePairIpv6, Ptr<PcapFileObject> > InterfaceFileMapIpv6;

InternetStackHelper::InternetStackHelper ()

  : m_routing (0),

  m_routingv6 (0),

  m_ipv4Enabled (true),

  m_ipv6Enabled (true)

{

  Initialize ();

}

// private method called by both constructor and Reset ()

void

InternetStackHelper::Initialize ()

{

  SetTcp ("ns3::TcpL4Protocol");

  Ipv4StaticRoutingHelper staticRouting;

  Ipv4GlobalRoutingHelper globalRouting;

  Ipv4ListRoutingHelper listRouting;

  Ipv6ListRoutingHelper listRoutingv6;

  Ipv6StaticRoutingHelper staticRoutingv6;

  listRouting.Add (staticRouting, 0);

  listRouting.Add (globalRouting, -10);

  listRoutingv6.Add (staticRoutingv6, 0);

  SetRoutingHelper (listRouting);

  SetRoutingHelper (listRoutingv6);

}

InternetStackHelper::~InternetStackHelper ()

{

  delete m_routing;

  delete m_routingv6;

}

InternetStackHelper::InternetStackHelper (const InternetStackHelper &o)

{

  m_routing = o.m_routing->Copy ();

  m_routingv6 = o.m_routingv6->Copy ();

  m_ipv4Enabled = o.m_ipv4Enabled;

  m_ipv6Enabled = o.m_ipv6Enabled;

  m_tcpFactory = o.m_tcpFactory;

}

InternetStackHelper &

InternetStackHelper::operator = (const InternetStackHelper &o)

{

  if (this == &o)

    {

      return *this;

    }

  m_routing = o.m_routing->Copy ();

  m_routingv6 = o.m_routingv6->Copy ();

  return *this;

}

void

InternetStackHelper::Reset (void)

{

  delete m_routing;

  m_routing = 0;

  delete m_routingv6;

  m_routingv6 = 0;

  m_ipv4Enabled = true;

  m_ipv6Enabled = true;

  Initialize ();

}

void 

InternetStackHelper::SetRoutingHelper (const Ipv4RoutingHelper &routing)

{

  delete m_routing;

  m_routing = routing.Copy ();

}

void

InternetStackHelper::SetRoutingHelper (const Ipv6RoutingHelper &routing)

{

  delete m_routingv6;

  m_routingv6 = routing.Copy ();

}

void

InternetStackHelper::SetIpv4StackInstall (bool enable)

{

  m_ipv4Enabled = enable;

}

void InternetStackHelper::SetIpv6StackInstall (bool enable)

{

  m_ipv6Enabled = enable;

}

void

InternetStackHelper::SetTcp (const std::string tid)

{

  m_tcpFactory.SetTypeId (tid);

}

void 

InternetStackHelper::SetTcp (std::string tid, std::string n0, const AttributeValue &v0)

{

  m_tcpFactory.SetTypeId (tid);

  m_tcpFactory.Set (n0,v0);

}

void 

InternetStackHelper::Install (NodeContainer c) const

{

  for (NodeContainer::Iterator i = c.Begin (); i != c.End (); ++i)

    {

      Install (*i);

    }

}

void 

InternetStackHelper::InstallAll (void) const

{

  Install (NodeContainer::GetGlobal ());

}

void

InternetStackHelper::CreateAndAggregateObjectFromTypeId (Ptr<Node> node, const std::string typeId)

{

  ObjectFactory factory;

  factory.SetTypeId (typeId);

  Ptr<Object> protocol = factory.Create <Object> ();

  node->AggregateObject (protocol);

}

void

InternetStackHelper::Install (Ptr<Node> node) const

{

  if (m_ipv4Enabled)

    {

      if (node->GetObject<Ipv4> () != 0)

        {

          NS_FATAL_ERROR ("InternetStackHelper::Install (): Aggregating " 

                          "an InternetStack to a node with an existing Ipv4 object");

          return;

        }

      CreateAndAggregateObjectFromTypeId (node, "ns3::ArpL3Protocol");

      CreateAndAggregateObjectFromTypeId (node, "ns3::Ipv4L3Protocol");

      CreateAndAggregateObjectFromTypeId (node, "ns3::Icmpv4L4Protocol");

      CreateAndAggregateObjectFromTypeId (node, "ns3::UdpL4Protocol");

      node->AggregateObject (m_tcpFactory.Create<Object> ());

      Ptr<PacketSocketFactory> factory = CreateObject<PacketSocketFactory> ();

      node->AggregateObject (factory);

      // Set routing

      Ptr<Ipv4> ipv4 = node->GetObject<Ipv4> ();

      Ptr<Ipv4RoutingProtocol> ipv4Routing = m_routing->Create (node);

      ipv4->SetRoutingProtocol (ipv4Routing);

    }

  if (m_ipv6Enabled)

    {

      /* IPv6 stack */

      if (node->GetObject<Ipv6> () != 0)

        {

          NS_FATAL_ERROR ("InternetStackHelper::Install (): Aggregating " 

                          "an InternetStack to a node with an existing Ipv6 object");

          return;

        }

      CreateAndAggregateObjectFromTypeId (node, "ns3::Ipv6L3Protocol");

      CreateAndAggregateObjectFromTypeId (node, "ns3::Icmpv6L4Protocol");

      /* TODO add UdpL4Protocol/TcpL4Protocol for IPv6 */

      Ptr<Ipv6> ipv6 = node->GetObject<Ipv6> ();

      Ptr<Ipv6RoutingProtocol> ipv6Routing = m_routingv6->Create (node);

      ipv6->SetRoutingProtocol (ipv6Routing);

      /* register IPv6 extensions and options */

      ipv6->RegisterExtensions ();

      ipv6->RegisterOptions ();

    }

}

void

InternetStackHelper::Install (std::string nodeName) const

{

  Ptr<Node> node = Names::Find<Node> (nodeName);

  Install (node);

}

static void

Ipv4L3ProtocolRxTxSink (Ptr<const Packet> p, Ptr<Ipv4> ipv4, uint32_t interface)

{

  NS_LOG_FUNCTION (p << ipv4 << interface);

  InterfacePairIpv4 pair = std::make_pair (ipv4, interface);

  if (g_interfaceFileMapIpv4.find (pair) == g_interfaceFileMapIpv4.end ())

    {

      NS_LOG_INFO ("Ignoring packet to/from interface " << interface);

      return;

    }

  Ptr<PcapFileObject> file = g_interfaceFileMapIpv4[pair];

  file->Write(Simulator::Now(), p);

}

void 

InternetStackHelper::EnablePcapIpv4Internal (std::string prefix, Ptr<Ipv4> ipv4, uint32_t interface)

{

  NS_LOG_FUNCTION (prefix << ipv4 << interface);

  PcapHelper pcapHelper;

  std::string filename = pcapHelper.GetFilenameFromInterfacePair (prefix, ipv4, interface);

  Ptr<PcapFileObject> file = pcapHelper.CreateFile (filename, "w", PcapHelper::DLT_RAW);

    {

      //

      // Ptr<Ipv4> is aggregated to node and Ipv4L3Protocol is aggregated to 

      // node so we can get to Ipv4L3Protocol through Ipv4.

      //

      Ptr<Ipv4L3Protocol> ipv4L3Protocol = ipv4->GetObject<Ipv4L3Protocol> ();

      NS_ASSERT_MSG (ipv4L3Protocol, "InternetStackHelper::EnablePcapIpv4Internal(): "

                     "m_ipv4Enabled and ipv4L3Protocol inconsistent");

      bool result = ipv4L3Protocol->TraceConnectWithoutContext ("Tx", MakeCallback (&Ipv4L3ProtocolRxTxSink));

      NS_ASSERT_MSG (result == true, "InternetStackHelper::EnablePcapIpv4Internal():  "

                     "Unable to connect ipv4L3Protocol \"Tx\"");

      result = ipv4L3Protocol->TraceConnectWithoutContext ("Rx", MakeCallback (&Ipv4L3ProtocolRxTxSink));

      NS_ASSERT_MSG (result == true, "InternetStackHelper::EnablePcapIpv4Internal():  "

                     "Unable to connect ipv4L3Protocol \"Rx\"");

    }

}