Files
unison/src/network/utils/pcap-file.h
2014-03-13 09:29:47 +01:00

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/* -*- 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;
/**
* \brief A class representing a pcap file
*
* 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; /**< Time zone offset for current location */
static const uint32_t SNAPLEN_DEFAULT = 65535; /**< Default value for maximum octets to save per packet */
public:
PcapFile ();
~PcapFile ();
/**
* \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, but differ in that
* positions in the file are based on packets not characters. For example
* if the file is opened for reading, the file position indicator (seek
* position) points to the beginning of the first packet in the file, not
* zero (which would point to the start of the pcap header).
*
* 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 the access mode for the file.
*/
void Open (std::string const &filename, std::ios::openmode mode);
/**
* Close the underlying file.
*/
void Close (void);
/**
* Initialize the pcap file associated with this object. 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 timeZoneCorrection 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).
*
* \param swapMode Flag indicating a difference in endianness of the
* writing system. Defaults to false.
*
* \return false if the open succeeds, true otherwise.
*
* \warning Calling this method on an existing file will result in the loss
* any existing data.
*/
void Init (uint32_t dataLinkType,
uint32_t snapLen = SNAPLEN_DEFAULT,
int32_t timeZoneCorrection = ZONE_DEFAULT,
bool swapMode = false);
/**
* \brief Write next packet to file
*
* \param tsSec Packet timestamp, seconds
* \param tsUsec Packet timestamp, microseconds
* \param data Data buffer
* \param totalLen Total packet length
*
*/
void Write (uint32_t tsSec, uint32_t tsUsec, uint8_t const * const data, uint32_t totalLen);
/**
* \brief Write next packet to file
*
* \param tsSec Packet timestamp, seconds
* \param tsUsec Packet timestamp, microseconds
* \param p Packet to write
*
*/
void Write (uint32_t tsSec, uint32_t tsUsec, Ptr<const Packet> p);
/**
* \brief Write next packet to file
*
* \param tsSec Packet timestamp, seconds
* \param tsUsec Packet timestamp, microseconds
* \param header Header to write, in front of packet
* \param p Packet to write
*
*/
void Write (uint32_t tsSec, uint32_t tsUsec, Header &header, Ptr<const Packet> p);
/**
* \brief Read next packet from file
*
* \param data [out] Data buffer
* \param maxBytes Allocated data buffer size
* \param tsSec [out] Packet timestamp, seconds
* \param tsUsec [out] Packet timestamp, microseconds
* \param inclLen [out] Included length
* \param origLen [out] Original length
* \param readLen [out] Number of bytes read
*
*/
void Read (uint8_t * const data,
uint32_t maxBytes,
uint32_t &tsSec,
uint32_t &tsUsec,
uint32_t &inclLen,
uint32_t &origLen,
uint32_t &readLen);
/**
* \brief Get the swap mode of the file.
*
* Pcap files use a magic number that is overloaded to identify both the
* format of the file itself and the byte ordering of the file. The magic
* number (and all data) is written into the file according to the native
* byte ordering of the writing system. If a reading application reads
* the magic number identically (for example 0xa1b2c3d4) then no byte
* swapping is required to correctly interpret the file data. If the reading
* application sees the magic number is byte swapped (for example 0xd4c3b2a1)
* then it knows that it needs to byteswap appropriate fields in the format.
*
* GetSWapMode returns a value indicating whether or not the fields are being
* byteswapped. Used primarily for testing the class itself, but may be
* useful as a flag indicating a difference in endianness of the writing
* system.
*
* \returns swap mode of the file
*/
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
*
* \returns magic number
*/
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
*
* \returns major version
*/
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
*
* \returns minor version
*/
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
*
* \returns time zone offset
*/
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
*
* \returns accuracy of timestamps
*/
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
*
* \returns max length of saved packets field
*/
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
*
* \returns data link type field
*/
uint32_t GetDataLinkType (void);
/**
* \brief Compare two PCAP files packet-by-packet
*
* \return true if files are different, false otherwise
*
* \param f1 First PCAP file name
* \param f2 Second PCAP file name
* \param sec [out] Time stamp of first different packet, seconds. Undefined if files doesn't differ.
* \param usec [out] Time stamp of first different packet, microseconds. Undefined if files doesn't differ.
* \param snapLen Snap length (if used)
*/
static bool Diff (std::string const & f1, std::string const & f2,
uint32_t & sec, uint32_t & usec,
uint32_t snapLen = SNAPLEN_DEFAULT);
private:
/**
* \brief Pcap file header
*/
typedef struct {
uint32_t m_magicNumber; /**< Magic number identifying this as a pcap file */
uint16_t m_versionMajor; /**< Major version identifying the version of pcap used in this file */
uint16_t m_versionMinor; /**< Minor version identifying the version of pcap used in this file */
int32_t m_zone; /**< Time zone correction to be applied to timestamps of packets */
uint32_t m_sigFigs; /**< Unused by pretty much everybody */
uint32_t m_snapLen; /**< Maximum length of packet data stored in records */
uint32_t m_type; /**< Data link type of packet data */
} PcapFileHeader;
/**
* \brief Pcap record header
*/
typedef struct {
uint32_t m_tsSec; /**< seconds part of timestamp */
uint32_t m_tsUsec; /**< microseconds part of timestamp (nsecs for PCAP_NSEC_MAGIC) */
uint32_t m_inclLen; /**< number of octets of packet saved in file */
uint32_t m_origLen; /**< actual length of original packet */
} PcapRecordHeader;
/**
* \brief Swap a value byte order
* \param val the value
* \returns the value with byte order swapped
*/
uint8_t Swap (uint8_t val);
/**
* \brief Swap a value byte order
* \param val the value
* \returns the value with byte order swapped
*/
uint16_t Swap (uint16_t val);
/**
* \brief Swap a value byte order
* \param val the value
* \returns the value with byte order swapped
*/
uint32_t Swap (uint32_t val);
/**
* \brief Swap the byte order of a Pcap file header
* \param from original file header
* \param to swapped file header
*/
void Swap (PcapFileHeader *from, PcapFileHeader *to);
/**
* \brief Swap the byte order of a Pcap record header
* \param from original record header
* \param to swapped record header
*/
void Swap (PcapRecordHeader *from, PcapRecordHeader *to);
/**
* \brief Write a Pcap file header
*/
void WriteFileHeader (void);
/**
* \brief Write a Pcap packet header
* \param tsSec Time stamp (seconds part)
* \param tsUsec Time stamp (microseconds part)
* \param totalLen total packet length
* \returns the length of the packet to write in the Pcap file
*/
uint32_t WritePacketHeader (uint32_t tsSec, uint32_t tsUsec, uint32_t totalLen);
/**
* \brief Read and verify a Pcap file header
*/
void ReadAndVerifyFileHeader (void);
std::string m_filename; //!< file name
std::fstream m_file; //!< file stream
PcapFileHeader m_fileHeader; //!< file header
bool m_swapMode; //!< swap mode
};
} // namespace ns3
#endif /* PCAP_FILE_H */