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

/*

 * Copyright (c) 2010 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>

 */

#ifndef TCP_RENO_H

#define TCP_RENO_H

#include "tcp-socket-base.h"

namespace ns3 {

/**

 * \ingroup socket

 * \ingroup tcp

 *

 * \brief An implementation of a stream socket using TCP.

 *

 * This class contains the Reno implementation of TCP, according to \RFC{2581},

 * except sec.4.1 "re-starting idle connections", which we do not detect for

 * idleness and thus no slow start upon resumption.

 */

class TcpReno : public TcpSocketBase

{

public:

  /**

   * \brief Get the type ID.

   * \return the object TypeId

   */

  static TypeId GetTypeId (void);

  /**

   * Create an unbound tcp socket.

   */

  TcpReno (void);

  /**

   * \brief Copy constructor

   * \param sock the object to copy

   */

  TcpReno (const TcpReno& sock);

  virtual ~TcpReno (void);

  // From TcpSocketBase

  virtual int Connect (const Address &address);

  virtual int Listen (void);

protected:

  virtual uint32_t Window (void); // Return the max possible number of unacked bytes

  virtual Ptr<TcpSocketBase> Fork (void); // Call CopyObject<TcpReno> to clone me

  virtual void NewAck (const SequenceNumber32& seq); // Inc cwnd and call NewAck() of parent

  virtual void DupAck (const TcpHeader& t, uint32_t count);  // Fast retransmit

  virtual void Retransmit (void); // Retransmit timeout

  // Implementing ns3::TcpSocket -- Attribute get/set

  virtual void     SetSegSize (uint32_t size);

  virtual void     SetSSThresh (uint32_t threshold);

  virtual uint32_t GetSSThresh (void) const;

  virtual void     SetInitialCwnd (uint32_t cwnd);

  virtual uint32_t GetInitialCwnd (void) const;

private:

  /**

   * \brief Set the congestion window when connection starts

   */

  void InitializeCwnd (void);

protected:

  TracedValue<uint32_t>  m_cWnd;         //!< Congestion window

  uint32_t               m_ssThresh;     //!< Slow Start Threshold

  uint32_t               m_initialCWnd;  //!< Initial cWnd value

  uint32_t               m_retxThresh;   //!< Fast Retransmit threshold

  bool                   m_inFastRec;    //!< currently in fast recovery

};

} // namespace ns3

#endif /* TCP_RENO_H */