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

/*

 * Copyright (c) 2005 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>

 */

#include "ns3/assert.h"

#include "ns3/address-utils.h"

#include "arp-header.h"

#include "ns3/log.h"

NS_OBJECT_ENSURE_REGISTERED (ArpHeader);

void 

ArpHeader::SetRequest (Address sourceHardwareAddress,

                       Ipv4Address sourceProtocolAddress,

                       Address destinationHardwareAddress,

                       Ipv4Address destinationProtocolAddress)

{

  NS_LOG_FUNCTION (this << sourceHardwareAddress << sourceProtocolAddress << destinationHardwareAddress << destinationProtocolAddress);

  m_type = ARP_TYPE_REQUEST;

  m_macSource = sourceHardwareAddress;

  m_macDest = destinationHardwareAddress;

  m_ipv4Source = sourceProtocolAddress;

  m_ipv4Dest = destinationProtocolAddress;

}

void 

ArpHeader::SetReply (Address sourceHardwareAddress,

                     Ipv4Address sourceProtocolAddress,

                     Address destinationHardwareAddress,

                     Ipv4Address destinationProtocolAddress)

{

  NS_LOG_FUNCTION (this << sourceHardwareAddress << sourceProtocolAddress << destinationHardwareAddress << destinationProtocolAddress);

  m_type = ARP_TYPE_REPLY;

  m_macSource = sourceHardwareAddress;

  m_macDest = destinationHardwareAddress;

  m_ipv4Source = sourceProtocolAddress;

  m_ipv4Dest = destinationProtocolAddress;

}

bool 

ArpHeader::IsRequest (void) const

{

  NS_LOG_FUNCTION (this);

  return (m_type == ARP_TYPE_REQUEST) ? true : false;

}

bool 

ArpHeader::IsReply (void) const

{

  NS_LOG_FUNCTION (this);

  return (m_type == ARP_TYPE_REPLY) ? true : false;

}

Address 

ArpHeader::GetSourceHardwareAddress (void)

{

  NS_LOG_FUNCTION (this);

  return m_macSource;

}

Address 

ArpHeader::GetDestinationHardwareAddress (void)

{

  NS_LOG_FUNCTION (this);

  return m_macDest;

}

Ipv4Address 

ArpHeader::GetSourceIpv4Address (void)

{

  NS_LOG_FUNCTION (this);

  return m_ipv4Source;

}

Ipv4Address 

ArpHeader::GetDestinationIpv4Address (void)

{

  NS_LOG_FUNCTION (this);

  return m_ipv4Dest;

}

TypeId 

ArpHeader::GetTypeId (void)

{

  static TypeId tid = TypeId ("ns3::ArpHeader")

    .SetParent<Header> ()

    .AddConstructor<ArpHeader> ()

  ;

  return tid;

}

TypeId 

ArpHeader::GetInstanceTypeId (void) const

{

  NS_LOG_FUNCTION (this);

  return GetTypeId ();

}

void 

ArpHeader::Print (std::ostream &os) const

{

  NS_LOG_FUNCTION (this << &os);

  if (IsRequest ()) 

    {

      os << "request "

         << "source mac: " << m_macSource << " "

         << "source ipv4: " << m_ipv4Source << " "

         << "dest ipv4: " << m_ipv4Dest

      ;

    } 

  else 

    {

      NS_ASSERT (IsReply ());

      os << "reply " 

         << "source mac: " << m_macSource << " "

         << "source ipv4: " << m_ipv4Source << " "

         << "dest mac: " << m_macDest << " "

         << "dest ipv4: " <<m_ipv4Dest

      ;

    }

}

uint32_t 

ArpHeader::GetSerializedSize (void) const

{

  NS_LOG_FUNCTION (this);

  NS_ASSERT((m_macSource.GetLength () == 6) || (m_macSource.GetLength () == 8));

  NS_ASSERT (m_macSource.GetLength () == m_macDest.GetLength ());

  uint32_t length = 16;   // Length minus two hardware addresses

  length += m_macSource.GetLength () * 2;

  return length;

}

void

ArpHeader::Serialize (Buffer::Iterator start) const

{

  NS_LOG_FUNCTION (this << &start);

  Buffer::Iterator i = start;

  NS_ASSERT (m_macSource.GetLength () == m_macDest.GetLength ());

  /* ethernet */

  i.WriteHtonU16 (0x0001);

  /* ipv4 */

  i.WriteHtonU16 (0x0800);

  i.WriteU8 (m_macSource.GetLength ());

  i.WriteU8 (4);

  i.WriteHtonU16 (m_type);

  WriteTo (i, m_macSource);

  WriteTo (i, m_ipv4Source);

  WriteTo (i, m_macDest);

  WriteTo (i, m_ipv4Dest);

}

uint32_t

ArpHeader::Deserialize (Buffer::Iterator start)

{

  NS_LOG_FUNCTION (this << &start);

  Buffer::Iterator i = start;

  i.Next (2);                                    // Skip HRD

  uint32_t protocolType = i.ReadNtohU16 ();      // Read PRO

  uint32_t hardwareAddressLen = i.ReadU8 ();     // Read HLN

  uint32_t protocolAddressLen = i.ReadU8 ();     // Read PLN

  //

  // It is implicit here that we have a protocol type of 0x800 (IP).

  // It is also implicit here that we are using Ipv4 (PLN == 4).

  // If this isn't the case, we need to return an error since we don't want to 

  // be too fragile if we get connected to real networks.

  //

  if (protocolType != 0x800 || protocolAddressLen != 4)

    {

      return 0;

    }

  m_type = i.ReadNtohU16 ();                     // Read OP

  ReadFrom (i, m_macSource, hardwareAddressLen); // Read SHA (size HLN)

  ReadFrom (i, m_ipv4Source);                    // Read SPA (size PLN == 4)

  ReadFrom (i, m_macDest, hardwareAddressLen);   // Read THA (size HLN)

  ReadFrom (i, m_ipv4Dest);                      // Read TPA (size PLN == 4)

  return GetSerializedSize ();

}

} // namespace ns3