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unison/src/internet/model/tcp-header.h
2016-01-22 14:30:39 +01:00

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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
* Copyright (c) 2007 Georgia Tech Research Corporation
*
* 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: Raj Bhattacharjea <raj.b@gatech.edu>
*/
#ifndef TCP_HEADER_H
#define TCP_HEADER_H
#include <stdint.h>
#include "ns3/header.h"
#include "ns3/tcp-option.h"
#include "ns3/buffer.h"
#include "ns3/tcp-socket-factory.h"
#include "ns3/ipv4-address.h"
#include "ns3/ipv6-address.h"
#include "ns3/sequence-number.h"
namespace ns3 {
/**
* \ingroup tcp
* \brief Header for the Transmission Control Protocol
*
* This class has fields corresponding to those in a network TCP header
* (port numbers, sequence and acknowledgement numbers, flags, etc) as well
* as methods for serialization to and deserialization from a byte buffer.
*/
class TcpHeader : public Header
{
public:
TcpHeader ();
virtual ~TcpHeader ();
/**
* \brief Print a TCP header into an output stream
*
* \param os output stream
* \param tc TCP header to print
* \return The ostream passed as first argument
*/
friend std::ostream& operator<< (std::ostream& os, TcpHeader const & tc);
/**
* \brief Converts an integer into a human readable list of Tcp flags
*
* \param flags Bitfield of TCP flags to convert to a readable string
* \param delimiter String to insert between flags
*
* FIN=0x1, SYN=0x2, RST=0x4, PSH=0x8, ACK=0x10, URG=0x20, ECE=0x40, CWR=0x80
* TcpHeader::FlagsToString (0x1) should return the following string;
* "FIN"
*
* TcpHeader::FlagsToString (0xff) should return the following string;
* "FIN|SYN|RST|PSH|ACK|URG|ECE|CWR";
*
* \return the generated string
**/
static std::string FlagsToString (uint8_t flags, const std::string& delimiter = "|");
/**
* \brief Enable checksum calculation for TCP
*
* \todo currently has no effect
*/
void EnableChecksums (void);
//Setters
/**
* \brief Set the source port
* \param port The source port for this TcpHeader
*/
void SetSourcePort (uint16_t port);
/**
* \brief Set the destination port
* \param port the destination port for this TcpHeader
*/
void SetDestinationPort (uint16_t port);
/**
* \brief Set the sequence Number
* \param sequenceNumber the sequence number for this TcpHeader
*/
void SetSequenceNumber (SequenceNumber32 sequenceNumber);
/**
* \brief Set the ACK number
* \param ackNumber the ACK number for this TcpHeader
*/
void SetAckNumber (SequenceNumber32 ackNumber);
/**
* \brief Set flags of the header
* \param flags the flags for this TcpHeader
*/
void SetFlags (uint8_t flags);
/**
* \brief Set the window size
* \param windowSize the window size for this TcpHeader
*/
void SetWindowSize (uint16_t windowSize);
/**
* \brief Set the urgent pointer
* \param urgentPointer the urgent pointer for this TcpHeader
*/
void SetUrgentPointer (uint16_t urgentPointer);
//Getters
/**
* \brief Get the source port
* \return The source port for this TcpHeader
*/
uint16_t GetSourcePort () const;
/**
* \brief Get the destination port
* \return the destination port for this TcpHeader
*/
uint16_t GetDestinationPort () const;
/**
* \brief Get the sequence number
* \return the sequence number for this TcpHeader
*/
SequenceNumber32 GetSequenceNumber () const;
/**
* \brief Get the ACK number
* \return the ACK number for this TcpHeader
*/
SequenceNumber32 GetAckNumber () const;
/**
* \brief Get the length in words
*
* A word is 4 bytes; without Tcp Options, header is 5 words (20 bytes).
* With options, it can reach up to 15 words (60 bytes).
*
* \return the length of this TcpHeader
*/
uint8_t GetLength () const;
/**
* \brief Get the flags
* \return the flags for this TcpHeader
*/
uint8_t GetFlags () const;
/**
* \brief Get the window size
* \return the window size for this TcpHeader
*/
uint16_t GetWindowSize () const;
/**
* \brief Get the urgent pointer
* \return the urgent pointer for this TcpHeader
*/
uint16_t GetUrgentPointer () const;
/**
* \brief Get the option specified
* \param kind the option to retrieve
* \return Whether the header contains a specific kind of option, or 0
*/
Ptr<TcpOption> GetOption (uint8_t kind) const;
/**
* \brief Get the total length of appended options
* \return the total length of options appended to this TcpHeader
*/
uint8_t GetOptionLength () const;
/**
* \brief Get maximum option length
* \return the maximum option length
*/
uint8_t GetMaxOptionLength () const;
/**
* \brief Check if the header has the option specified
* \param kind Option to check for
* \return true if the header has the option, false otherwise
*/
bool HasOption (uint8_t kind) const;
/**
* \brief Append an option to the TCP header
* \param option The option to append
* \return true if option has been appended, false otherwise
*/
bool AppendOption (Ptr<TcpOption> option);
/**
* \brief Initialize the TCP checksum.
*
* If you want to use tcp checksums, you should call this
* method prior to adding the header to a packet.
*
* \param source the IP source to use in the underlying
* IP packet.
* \param destination the IP destination to use in the
* underlying IP packet.
* \param protocol the protocol number to use in the underlying
* IP packet.
*
*/
void InitializeChecksum (const Ipv4Address &source,
const Ipv4Address &destination,
uint8_t protocol);
/**
* \brief Initialize the TCP checksum.
*
* If you want to use tcp checksums, you should call this
* method prior to adding the header to a packet.
*
* \param source the IP source to use in the underlying
* IP packet.
* \param destination the IP destination to use in the
* underlying IP packet.
* \param protocol the protocol number to use in the underlying
* IP packet.
*
*/
void InitializeChecksum (const Ipv6Address &source,
const Ipv6Address &destination,
uint8_t protocol);
/**
* \brief Initialize the TCP checksum.
*
* If you want to use tcp checksums, you should call this
* method prior to adding the header to a packet.
*
* \param source the IP source to use in the underlying
* IP packet.
* \param destination the IP destination to use in the
* underlying IP packet.
* \param protocol the protocol number to use in the underlying
* IP packet.
*
*/
void InitializeChecksum (const Address &source,
const Address &destination,
uint8_t protocol);
/**
* \brief TCP flag field values
*/
typedef enum
{
NONE = 0, //!< No flags
FIN = 1, //!< FIN
SYN = 2, //!< SYN
RST = 4, //!< Reset
PSH = 8, //!< Push
ACK = 16, //!< Ack
URG = 32, //!< Urgent
ECE = 64, //!< ECE
CWR = 128 //!< CWR
} Flags_t;
/**
* \brief Get the type ID.
* \return the object TypeId
*/
static TypeId GetTypeId (void);
virtual TypeId GetInstanceTypeId (void) const;
virtual void Print (std::ostream &os) const;
virtual uint32_t GetSerializedSize (void) const;
virtual void Serialize (Buffer::Iterator start) const;
virtual uint32_t Deserialize (Buffer::Iterator start);
/**
* \brief Is the TCP checksum correct ?
* \returns true if the checksum is correct, false otherwise.
*/
bool IsChecksumOk (void) const;
/**
* Comparison operator
* \param lhs left operand
* \param rhs right operand
* \return true if the operands are equal
*/
friend bool operator== (const TcpHeader &lhs, const TcpHeader &rhs);
private:
/**
* \brief Calculate the header checksum
* \param size packet size
* \returns the checksum
*/
uint16_t CalculateHeaderChecksum (uint16_t size) const;
/**
* \brief Calculates the header length (in words)
*
* Given the standard size of the header, the method checks for options
* and calculates the real length (in words).
*
* \return header length in 4-byte words
*/
uint8_t CalculateHeaderLength () const;
uint16_t m_sourcePort; //!< Source port
uint16_t m_destinationPort; //!< Destination port
SequenceNumber32 m_sequenceNumber; //!< Sequence number
SequenceNumber32 m_ackNumber; //!< ACK number
uint8_t m_length; //!< Length (really a uint4_t) in words.
uint8_t m_flags; //!< Flags (really a uint6_t)
uint16_t m_windowSize; //!< Window size
uint16_t m_urgentPointer; //!< Urgent pointer
Address m_source; //!< Source IP address
Address m_destination; //!< Destination IP address
uint8_t m_protocol; //!< Protocol number
bool m_calcChecksum; //!< Flag to calculate checksum
bool m_goodChecksum; //!< Flag to indicate that checksum is correct
static const uint8_t m_maxOptionsLen = 40; //!< Maximum options length
typedef std::list< Ptr<TcpOption> > TcpOptionList; //!< List of TcpOption
TcpOptionList m_options; //!< TcpOption present in the header
uint8_t m_optionsLen; //!< Tcp options length.
};
} // namespace ns3
#endif /* TCP_HEADER */