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

/*

 * Copyright (c) 2011 Adrian Sai-wah Tam

 *

 * 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: Adrian Sai-wah Tam <adrian.sw.tam@gmail.com>

 * Documentation, test cases: Natale Patriciello <natale.patriciello@gmail.com>

 */

#include "tcp-option-winscale.h"

#include "ns3/log.h"

namespace ns3 {

NS_LOG_COMPONENT_DEFINE ("TcpOptionWinScale");

NS_OBJECT_ENSURE_REGISTERED (TcpOptionWinScale);

TcpOptionWinScale::TcpOptionWinScale ()

  : TcpOption (),

    m_scale (0)

{

}

TcpOptionWinScale::~TcpOptionWinScale ()

{

}

TypeId

TcpOptionWinScale::GetTypeId (void)

{

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

    .SetParent<TcpOption> ()

    .SetGroupName ("Internet")

    .AddConstructor<TcpOptionWinScale> ()

  ;

  return tid;

}

TypeId

TcpOptionWinScale::GetInstanceTypeId (void) const

{

  return GetTypeId ();

}

void

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

{

  os << static_cast<int> (m_scale);

}

uint32_t

TcpOptionWinScale::GetSerializedSize (void) const

{

  return 3;

}

void

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

{

  Buffer::Iterator i = start;

  i.WriteU8 (GetKind ()); // Kind

  i.WriteU8 (3); // Length

  i.WriteU8 (m_scale); // Max segment size

}

uint32_t

TcpOptionWinScale::Deserialize (Buffer::Iterator start)

{

  Buffer::Iterator i = start;

  uint8_t readKind = i.ReadU8 ();

  if (readKind != GetKind ())

    {

      NS_LOG_WARN ("Malformed Window Scale option");

      return 0;

    }

  uint8_t size = i.ReadU8 ();

  if (size != 3)

    {

      NS_LOG_WARN ("Malformed Window Scale option");

      return 0;

    }

  m_scale = i.ReadU8 ();

  return GetSerializedSize ();

}

uint8_t

TcpOptionWinScale::GetKind (void) const

{

  return TcpOption::WINSCALE;

}

uint8_t

TcpOptionWinScale::GetScale (void) const

{

  NS_ASSERT (m_scale <= 14);

  return m_scale;

}

void

TcpOptionWinScale::SetScale (uint8_t scale)

{

  NS_ASSERT (scale <= 14);

  m_scale = scale;

}

} // namespace ns3