/* -*- 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>

 */

#include "tcp-option-ts.h"

#include "ns3/log.h"

namespace ns3 {

NS_LOG_COMPONENT_DEFINE ("TcpOptionTS");

NS_OBJECT_ENSURE_REGISTERED (TcpOptionTS);

TcpOptionTS::TcpOptionTS ()

  : TcpOption (),

    m_timestamp (0),

    m_echo (0)

{

}

TcpOptionTS::~TcpOptionTS ()

{

}

TypeId

TcpOptionTS::GetTypeId (void)

{

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

    .SetParent<TcpOption> ()

    .AddConstructor<TcpOptionTS> ()

  ;

  return tid;

}

TypeId

TcpOptionTS::GetInstanceTypeId (void) const

{

  return GetTypeId ();

}

void

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

{

  os << m_timestamp << ";" << m_echo;

}

uint32_t

TcpOptionTS::GetSerializedSize (void) const

{

  return 10;

}

void

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

{

  Buffer::Iterator i = start;

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

  i.WriteU8 (10); // Length

  i.WriteHtonU32 (m_timestamp); // Local timestamp

  i.WriteHtonU32 (m_echo); // Echo timestamp

}

uint32_t

TcpOptionTS::Deserialize (Buffer::Iterator start)

{

  Buffer::Iterator i = start;

  uint8_t readKind = i.ReadU8 ();

  if (readKind != GetKind ())

    {

      NS_LOG_WARN ("Malformed Timestamp option");

      return 0;

    }

  uint8_t size = i.ReadU8 ();

  if (size != 10)

    {

      NS_LOG_WARN ("Malformed Timestamp option");

      return 0;

    }

  m_timestamp = i.ReadNtohU32 ();

  m_echo = i.ReadNtohU32 ();

  return GetSerializedSize ();

}

uint8_t

TcpOptionTS::GetKind (void) const

{

  return TcpOption::TS;

}

uint32_t

TcpOptionTS::GetTimestamp (void) const

{

  return m_timestamp;

}

uint32_t

TcpOptionTS::GetEcho (void) const

{

  return m_echo;

}

void

TcpOptionTS::SetTimestamp (uint32_t ts)

{

  m_timestamp = ts;

}

void

TcpOptionTS::SetEcho (uint32_t ts)

{

  m_echo = ts;

}

uint32_t

TcpOptionTS::NowToTsValue ()

{

  uint64_t now = (uint64_t) Simulator::Now ().GetMilliSeconds ();

  // high: (now & 0xFFFFFFFF00000000ULL) >> 32;

  // low: now & 0xFFFFFFFF

  return (now & 0xFFFFFFFF);

}

Time

TcpOptionTS::ElapsedTimeFromTsValue (uint32_t echoTime)

{

  uint64_t now64 = (uint64_t) Simulator::Now ().GetMilliSeconds ();

  uint32_t now32 = now64 & 0xFFFFFFFF;

  Time ret = Seconds (0.0);

  if (now32 > echoTime)

    {

      ret = MilliSeconds (now32 - echoTime);

    }

  return ret;

}

} // namespace ns3