// Copyright (c) 2003-2010 Christopher M. Kohlhoff
// Modifications (c) 2011 by Guilherme Maciel Ferreira / Intra2net AG
//
// Distributed under the Boost Software License, Version 1.0.
//    (See accompanying file LICENSE_1_0.txt or copy at
//          http://www.boost.org/LICENSE_1_0.txt)
#ifndef IPV4_HEADER_H
#define IPV4_HEADER_H

#include <stdint.h>

#include <boost/asio/ip/address_v4.hpp>

#include "ip/ipheader.h"

//-----------------------------------------------------------------------------
// Ipv4Header
//-----------------------------------------------------------------------------

/**
 * @brief This class represents the IP version 4 Packet Header.
 *
 * The IPv4 header format is:
 *
 * @code
 * 0      3 4     7 8            15 16                           31
 * +-------+-------+---------------+------------------------------+      ---
 * |       |       |               |                              |       ^
 * |version|header | differentiated|    total length in bytes     |       |
 * |  (4)  | length|    services   |                              |       |
 * +-------+-------+---------------+-+-+-+------------------------+       |
 * |                               | | | |                        |       |
 * |        identification         |0|D|M|    fragment offset     |       |
 * |                               | |F|F|                        |       |
 * +---------------+---------------+-+-+-+------------------------+       |
 * |               |               |                              |       |
 * | time to live  |   protocol    |       header checksum        |   20 bytes
 * |               |               |                              |       |
 * +---------------+---------------+------------------------------+       |
 * |                                                              |       |
 * |                      source IPv4 address                     |       |
 * |                                                              |       |
 * +--------------------------------------------------------------+       |
 * |                                                              |       |
 * |                   destination IPv4 address                   |       |
 * |                                                              |       v
 * +--------------------------------------------------------------+      ---
 * |                                                              |       ^
 * |                                                              |       |
 * /                        options (if any)                      /    0 - 40
 * /                                                              /     bytes
 * |                                                              |       |
 * |                                                              |       v
 * +--------------------------------------------------------------+      ---
 * @endcode
 */
class Ipv4Header : public IpHeader
{
public:
    Ipv4Header();

    uint8_t get_version() const;
    uint16_t get_header_length() const;
    uint8_t get_differentiated_services() const;
    uint16_t get_total_length() const;

    uint16_t get_identification() const;
    bool dont_fragment() const;
    bool more_fragments() const;
    uint16_t get_fragment_offset() const;

    uint8_t get_time_to_live() const;
    uint8_t get_protocol() const;
    uint16_t get_header_checksum() const;

    boost::asio::ip::address get_source_address() const;
    boost::asio::ip::address get_destination_address() const;

    friend std::istream &operator>>(
            std::istream &is,
            Ipv4Header &header
    );

};

#endif // IPV4_HEADER_H