pcap-file.h

/* -*- 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
 * 
 * Author:  Craig Dowell (craigdo@ee.washington.edu)
 */

#ifndef PCAP_FILE_H
#define PCAP_FILE_H

#include <string>
#include <fstream>
#include <stdint.h>
#include "ns3/ptr.h"

namespace ns3 {

class Packet;
class Header;

/*
 * A class representing a pcap file.  This allows easy creation, writing and 
 * reading of files composed of stored packets; which may be viewed using
 * standard tools.
 */

class PcapFile
{
public:
  static const int32_t  ZONE_DEFAULT    = 0;           
  static const uint32_t SNAPLEN_DEFAULT = 65535;       
public:
  PcapFile ();
  ~PcapFile ();

  bool Fail (void) const;
  bool Eof (void) const;
  void Clear (void);

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

  void Close (void);

  void Init (uint32_t dataLinkType, 
             uint32_t snapLen = SNAPLEN_DEFAULT, 
             int32_t timeZoneCorrection = ZONE_DEFAULT,
             bool swapMode = false);

  void Write (uint32_t tsSec, uint32_t tsUsec, uint8_t const * const data, uint32_t totalLen);

  void Write (uint32_t tsSec, uint32_t tsUsec, Ptr<const Packet> p);
  void Write (uint32_t tsSec, uint32_t tsUsec, Header &header, Ptr<const Packet> p);


  void Read (uint8_t * const data, 
             uint32_t maxBytes,
             uint32_t &tsSec, 
             uint32_t &tsUsec, 
             uint32_t &inclLen, 
             uint32_t &origLen, 
             uint32_t &readLen);

  bool GetSwapMode (void);

  /*
   * \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);

  static bool Diff (std::string const & f1, std::string const & f2, 
                    uint32_t & sec, uint32_t & usec, 
                    uint32_t snapLen = SNAPLEN_DEFAULT);

private:
  typedef struct {
    uint32_t m_magicNumber;   
    uint16_t m_versionMajor;  
    uint16_t m_versionMinor;  
    int32_t  m_zone;          
    uint32_t m_sigFigs;       
    uint32_t m_snapLen;       
    uint32_t m_type;          
  } PcapFileHeader;

  typedef struct {
    uint32_t m_tsSec;         
    uint32_t m_tsUsec;        
    uint32_t m_inclLen;       
    uint32_t m_origLen;       
  } PcapRecordHeader;

  uint8_t Swap (uint8_t val);
  uint16_t Swap (uint16_t val);
  uint32_t Swap (uint32_t val);
  void Swap (PcapFileHeader *from, PcapFileHeader *to);
  void Swap (PcapRecordHeader *from, PcapRecordHeader *to);

  void WriteFileHeader (void);
  uint32_t WritePacketHeader (uint32_t tsSec, uint32_t tsUsec, uint32_t totalLen);
  void ReadAndVerifyFileHeader (void);

  std::string    m_filename;
  std::fstream   m_file;
  PcapFileHeader m_fileHeader;
  bool m_swapMode;
};

} // namespace ns3

#endif /* PCAP_FILE_H */