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

/*

 * Copyright (c) 2009 University of Washington

 *

 * 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

 */

#ifndef PCAP_FILE_WRAPPER_H

#define PCAP_FILE_WRAPPER_H

#include <limits>

#include <fstream>

#include "ns3/ptr.h"

#include "ns3/packet.h"

#include "ns3/object.h"

#include "ns3/nstime.h"

#include "pcap-file.h"

namespace ns3 {

/*

 * A class that wraps a PcapFile as an ns3::Object and provides a higher-layer

 * ns-3 interface to the low-level public methods of PcapFile.  Users are

 * encouraged to use this object instead of class ns3::PcapFile in ns-3

 * public APIs.

 */

class PcapFileWrapper : public Object

{

public:

  static TypeId GetTypeId (void);

  PcapFileWrapper ();

  ~PcapFileWrapper ();

  /**

   * \return true if the 'fail' bit is set in the underlying iostream, false otherwise.

   */

  bool Fail (void) const;

  /**

   * \return true if the 'eof' bit is set in the underlying iostream, false otherwise.

   */

  bool Eof (void) const;

  /**

   * Clear all state bits of the underlying iostream.

   */

  void Clear (void);

  /**

   * Create a new pcap file or open an existing pcap file.  Semantics are

   * similar to the stdc++ io stream classes.

   *

   * Since a pcap file is always a binary file, the file type is automatically 

   * selected as a binary file (fstream::binary is automatically ored with the mode

   * field).

   *

   * \param filename String containing the name of the file.

   *

   * \param mode String containing the access mode for the file.

   *

   */

  void Open (std::string const &filename, std::ios::openmode mode);

  /**

   * Close the underlying pcap file.

   */

  void Close (void);

  /**

   * Initialize the pcap file associated with this wrapper.  This file must have

   * been previously opened with write permissions.

   *

   * \param dataLinkType A data link type as defined in the pcap library.  If

   * you want to make resulting pcap files visible in existing tools, the 

   * data link type must match existing definitions, such as PCAP_ETHERNET,

   * PCAP_PPP, PCAP_80211, etc.  If you are storing different kinds of packet

   * data, such as naked TCP headers, you are at liberty to locally define your

   * own data link types.  According to the pcap-linktype man page, "well-known"

   * pcap linktypes range from 0 to 177.  If you use a large random number for

   * your type, chances are small for a collision.

   *

   * \param snapLen An optional maximum size for packets written to the file.

   * Defaults to 65535.  If packets exceed this length they are truncated.

   *

   * \param tzCorrection An integer describing the offset of your local

   * time zone from UTC/GMT.  For example, Pacific Standard Time in the US is

   * GMT-8, so one would enter -8 for that correction.  Defaults to 0 (UTC).

   *

   * \warning Calling this method on an existing file will result in the loss

   * any existing data.

   */

  void Init (uint32_t dataLinkType, 

             uint32_t snapLen = std::numeric_limits<uint32_t>::max (), 

             int32_t tzCorrection = PcapFile::ZONE_DEFAULT);

  /**

   * \brief Write the next packet to file

   * 

   * \param t Packet timestamp as ns3::Time.

   * \param p Packet to write to the pcap file.

   * 

   */

  void Write (Time t, Ptr<const Packet> p);

  /**

   * \brief Write the provided header along with the packet to the pcap file.

   *

   * It is the case that adding a header to a packet prior to writing it to a

   * file must trigger a deep copy in the Packet.  By providing the header

   * separately, we can avoid that copy.

   * 

   * \param t Packet timestamp as ns3::Time.

   * \param header The Header to prepend to the packet.

   * \param p Packet to write to the pcap file.

   * 

   */

  void Write (Time t, Header &header, Ptr<const Packet> p);

  /**

   * \brief Write the provided data buffer to the pcap file.

   *

   * \param t Packet timestamp as ns3::Time.

   * \param buffer The buffer to write.

   * \param length The size of the buffer.

   * 

   */

  void Write (Time t, uint8_t const *buffer, uint32_t length);

  /*

   * \brief Returns the magic number of the pcap file as defined by the magic_number

   * field in the pcap global header.

   *

   * See http://wiki.wireshark.org/Development/LibpcapFileFormat

   */ 

  uint32_t GetMagic (void);

  /*

   * \brief Returns the major version of the pcap file as defined by the version_major

   * field in the pcap global header.

   *

   * See http://wiki.wireshark.org/Development/LibpcapFileFormat

   */ 

  uint16_t GetVersionMajor (void);

  /*

   * \brief Returns the minor version of the pcap file as defined by the version_minor

   * field in the pcap global header.

   *

   * See http://wiki.wireshark.org/Development/LibpcapFileFormat

   */ 

  uint16_t GetVersionMinor (void);

  /*

   * \brief Returns the time zone offset of the pcap file as defined by the thiszone

   * field in the pcap global header.

   *

   * See http://wiki.wireshark.org/Development/LibpcapFileFormat

   */ 

  int32_t GetTimeZoneOffset (void);

  /*

   * \brief Returns the accuracy of timestamps field of the pcap file as defined

   * by the sigfigs field in the pcap global header.

   *

   * See http://wiki.wireshark.org/Development/LibpcapFileFormat

   */ 

  uint32_t GetSigFigs (void);

  /*

   * \brief Returns the max length of saved packets field of the pcap file as 

   * defined by the snaplen field in the pcap global header.

   *

   * See http://wiki.wireshark.org/Development/LibpcapFileFormat

   */ 

  uint32_t GetSnapLen (void);

  /*

   * \brief Returns the data link type field of the pcap file as defined by the 

   * network field in the pcap global header.

   *

   * See http://wiki.wireshark.org/Development/LibpcapFileFormat

   */ 

  uint32_t GetDataLinkType (void);

private:

  PcapFile m_file;

  uint32_t m_snapLen;

};

} // namespace ns3

#endif /* PCAP_FILE_WRAPPER_H */