/* -*- 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/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 "internet-stack-helper.h"

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

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

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

#include <limits>

namespace ns3 {

std::vector<InternetStackHelper::Trace> InternetStackHelper::m_traces;

std::string InternetStackHelper::m_pcapBaseFilename;

bool InternetStackHelper::m_isInitialized = false;

InternetStackHelper::InternetStackHelper ()

{

  SetTcp ("ns3::TcpL4Protocol");

  static Ipv4StaticRoutingHelper staticRouting;

  static Ipv4GlobalRoutingHelper globalRouting;

  static Ipv4ListRoutingHelper listRouting;

  if (m_isInitialized == false)

    {

      // Only add these once

      listRouting.Add (staticRouting, 0);

      listRouting.Add (globalRouting, -10);

      m_isInitialized = true;

    }

  SetRoutingHelper (listRouting);

}

void 

InternetStackHelper::SetRoutingHelper (const Ipv4RoutingHelper &routing)

{

  m_routing = &routing;

}

void

InternetStackHelper::Cleanup (void)

{

  uint32_t illegal = std::numeric_limits<uint32_t>::max();

  for (std::vector<Trace>::iterator i = m_traces.begin ();

       i != m_traces.end (); i++)

  {

    i->nodeId = illegal;

    i->interfaceId = illegal;

    i->writer = 0;

  }

  m_traces.clear ();

}

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 (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);

}

void

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

{

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

  Install (node);

}

void

InternetStackHelper::EnableAscii (std::ostream &os, NodeContainer n)

{

  Packet::EnablePrinting ();

  std::ostringstream oss;

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

    {

      Ptr<Node> node = *i;

      oss << "/NodeList/" << node->GetId () << "/$ns3::Ipv4L3Protocol/Drop";

      Config::Connect (oss.str (), MakeBoundCallback (&InternetStackHelper::AsciiDropEvent, &os));

      oss.str ("");

      oss << "/NodeList/" << node->GetId () << "/$ns3::ArpL3Protocol/Drop";

      Config::Connect (oss.str (), MakeBoundCallback (&InternetStackHelper::AsciiDropEvent, &os));

      oss.str ("");

    }

}

void

InternetStackHelper::EnableAsciiAll (std::ostream &os)

{

  EnableAscii (os, NodeContainer::GetGlobal ());

}

void

InternetStackHelper::EnablePcapAll (std::string filename)

{

  Simulator::ScheduleDestroy (&InternetStackHelper::Cleanup);

  InternetStackHelper::m_pcapBaseFilename = filename;

  Config::Connect ("/NodeList/*/$ns3::Ipv4L3Protocol/Tx",

                   MakeCallback (&InternetStackHelper::LogTxIp));

  Config::Connect ("/NodeList/*/$ns3::Ipv4L3Protocol/Rx",

                   MakeCallback (&InternetStackHelper::LogRxIp));

}

uint32_t

InternetStackHelper::GetNodeIndex (std::string context)

{

  std::string::size_type pos;

  pos = context.find ("/NodeList/");

  NS_ASSERT (pos == 0);

  std::string::size_type afterNodeIndex = context.find ("/", 11);

  NS_ASSERT (afterNodeIndex != std::string::npos);

  std::string index = context.substr (10, afterNodeIndex - 10);

  std::istringstream iss;

  iss.str (index);

  uint32_t nodeIndex;

  iss >> nodeIndex;

  return nodeIndex;

}

void

InternetStackHelper::LogTxIp (std::string context, Ptr<const Packet> packet, uint32_t interfaceIndex)

{

  Ptr<PcapWriter> writer = InternetStackHelper::GetStream (GetNodeIndex (context), interfaceIndex);

  writer->WritePacket (packet);

}

void

InternetStackHelper::LogRxIp (std::string context, Ptr<const Packet> packet, uint32_t interfaceIndex)

{

  Ptr<PcapWriter> writer = InternetStackHelper::GetStream (GetNodeIndex (context), interfaceIndex);

  writer->WritePacket (packet);

}

Ptr<PcapWriter>

InternetStackHelper::GetStream (uint32_t nodeId, uint32_t interfaceId)

{

  for (std::vector<Trace>::iterator i = m_traces.begin ();

       i != m_traces.end (); i++)

  {

    if (i->nodeId == nodeId &&

        i->interfaceId == interfaceId)

    {

      return i->writer;

    }

  }

  InternetStackHelper::Trace trace;

  trace.nodeId = nodeId;

  trace.interfaceId = interfaceId;

  std::ostringstream oss;

  oss << m_pcapBaseFilename << "-" << nodeId << "-" << interfaceId << ".pcap";

  trace.writer->Open (oss.str ());

  trace.writer->WriteIpHeader ();

  m_traces.push_back (trace);

  return trace.writer;

}

void

InternetStackHelper::AsciiDropEvent (std::ostream *os, std::string path, Ptr<const Packet> packet)

{

  *os << "d " << Simulator::Now ().GetSeconds () << " ";

  *os << path << " " << *packet << std::endl;

}

} // namespace ns3