tcp-option-sack.cc

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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2011 Adrian Sai-wah Tam
 * Copyright (c) 2015 ResiliNets, ITTC, University of Kansas
 *
 * 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
 *
 * Original Author: Adrian Sai-wah Tam <adrian.sw.tam@gmail.com>
 * Documentation, test cases: Truc Anh N. Nguyen   <annguyen@ittc.ku.edu>
 *                            ResiliNets Research Group   http://wiki.ittc.ku.edu/resilinets
 *                            The University of Kansas
 *                            James P.G. Sterbenz <jpgs@ittc.ku.edu>, director
 */

#include "tcp-option-sack.h"
#include "ns3/log.h"

namespace ns3 {

NS_LOG_COMPONENT_DEFINE ("TcpOptionSack");

NS_OBJECT_ENSURE_REGISTERED (TcpOptionSack);

TcpOptionSack::TcpOptionSack ()
  : TcpOption ()
{
}

TcpOptionSack::~TcpOptionSack ()
{
}

TypeId
TcpOptionSack::GetTypeId (void)
{
  static TypeId tid = TypeId ("ns3::TcpOptionSack")
    .SetParent<TcpOption> ()
    .SetGroupName ("Internet")
    .AddConstructor<TcpOptionSack> ()
  ;
  return tid;
}

TypeId
TcpOptionSack::GetInstanceTypeId (void) const
{
  return GetTypeId ();
}

void
TcpOptionSack::Print (std::ostream &os) const
{
  os << "blocks: " << GetNumSackBlocks () << ",";
  for (SackList::const_iterator it = m_sackList.begin (); it != m_sackList.end (); ++it)
    {
      os << "[" << it->first << "," << it->second << "]";
    }
}

uint32_t
TcpOptionSack::GetSerializedSize (void) const
{
  NS_LOG_FUNCTION (this);
  NS_LOG_LOGIC ("Serialized size: " << 2 + GetNumSackBlocks () * 8);
  return 2 + GetNumSackBlocks () * 8;
}

void
TcpOptionSack::Serialize (Buffer::Iterator start) const
{
  NS_LOG_FUNCTION (this);
  Buffer::Iterator i = start;
  i.WriteU8 (GetKind ()); // Kind
  uint8_t length = static_cast<uint8_t> (GetNumSackBlocks () * 8 + 2);
  i.WriteU8 (length); // Length

  for (SackList::const_iterator it = m_sackList.begin (); it != m_sackList.end (); ++it)
    {
      SequenceNumber32 leftEdge = it->first;
      SequenceNumber32 rightEdge = it->second;
      i.WriteHtonU32 (leftEdge.GetValue ());   // Left edge of the block
      i.WriteHtonU32 (rightEdge.GetValue ());  // Right edge of the block
    }
}

uint32_t
TcpOptionSack::Deserialize (Buffer::Iterator start)
{
  NS_LOG_FUNCTION (this);
  Buffer::Iterator i = start;
  uint8_t readKind = i.ReadU8 ();
  if (readKind != GetKind ())
    {
      NS_LOG_WARN ("Malformed SACK option, wrong type");
      return 0;
    }

  uint8_t size = i.ReadU8 ();
  NS_LOG_LOGIC ("Size: " << static_cast<uint32_t> (size));
  m_sackList.empty ();
  uint8_t sackCount = (size - 2) / 8;
  while (sackCount)
    {
      SequenceNumber32 leftEdge = SequenceNumber32 (i.ReadNtohU32 ());
      SequenceNumber32 rightEdge = SequenceNumber32 (i.ReadNtohU32 ());
      SackBlock s (leftEdge, rightEdge);
      AddSackBlock (s);
      sackCount--;
    }

  return GetSerializedSize ();
}

uint8_t
TcpOptionSack::GetKind (void) const
{
  return TcpOption::SACK;
}

void
TcpOptionSack::AddSackBlock (SackBlock s)
{
  NS_LOG_FUNCTION (this);
  m_sackList.push_back (s);
}

uint32_t
TcpOptionSack::GetNumSackBlocks (void) const
{
  NS_LOG_FUNCTION (this);
  NS_LOG_LOGIC ("Number of SACK blocks appended: " << m_sackList.size ());
  return static_cast<uint32_t> (m_sackList.size ());
}

void
TcpOptionSack::ClearSackList (void)
{
  m_sackList.clear ();
}

TcpOptionSack::SackList
TcpOptionSack::GetSackList (void) const
{
  NS_LOG_FUNCTION (this);
  return m_sackList;
}

std::ostream &
operator<< (std::ostream & os, TcpOptionSack const & sackOption)
{
  std::stringstream ss;
  ss << "{";
  for (auto it = sackOption.m_sackList.begin (); it != sackOption.m_sackList.end (); ++it)
    {
      ss << *it;
    }
  ss << "}";
  os << ss.str ();
  return os;
}

std::ostream &
operator<< (std::ostream & os, TcpOptionSack::SackBlock const & sackBlock)
{
  std::stringstream ss;
  ss << "[" << sackBlock.first << ";" << sackBlock.second << "]";
  os << ss.str ();
  return os;
}

} // namespace ns3