/*
The software in this package is distributed under the GNU General
Public License version 2 (with a special exception described below).

A copy of GNU General Public License (GPL) is included in this distribution,
in the file COPYING.GPL.

As a special exception, if other files instantiate templates or use macros
or inline functions from this file, or you compile this file and link it
with other works to produce a work based on this file, this file
does not by itself cause the resulting work to be covered
by the GNU General Public License.

However the source code for this file must still be made available
in accordance with section (3) of the GNU General Public License.

This exception does not invalidate any other reasons why a work based
on this file might be covered by the GNU General Public License.
*/

#define BOOST_TEST_MAIN
#define BOOST_TEST_DYN_LINK

#include <streambuf>

#include <boost/asio.hpp>
#include <boost/test/unit_test.hpp>

#include "tcp/tcpheader.h"

BOOST_AUTO_TEST_SUITE( TestTcpHeader )

BOOST_AUTO_TEST_CASE( ack_received )
{
    uint8_t raw_segment_stream[] = {
        0x9f, 0x70, 0x00, 0x50, 0x58, 0xb6, 0x52, 0x49, 0x00, 0x00, 0x00, 0x00,
        0xa0, 0x02, 0x39, 0x08, 0xf7, 0x27, 0x00, 0x00, 0x02, 0x04, 0x05, 0xb4,
        0x04, 0x02, 0x08, 0x0a, 0x00, 0x05, 0x59, 0x20, 0x00, 0x00, 0x00, 0x00,
        0x01, 0x03, 0x03, 0x06
    };

    std::basic_stringbuf<uint8_t> sb;
    sb.pubsetbuf( raw_segment_stream, sizeof(raw_segment_stream) );
    std::basic_istream<uint8_t> is( &sb );

    TcpHeader tcp_header;
    reinterpret_cast<std::istream&>(is) >> tcp_header;

    BOOST_CHECK_EQUAL( tcp_header.get_source_port(), 40816 );
    BOOST_CHECK_EQUAL( tcp_header.get_destination_port(), 80 );
    BOOST_CHECK_EQUAL( tcp_header.get_acknowledgment_number(), 0 );
    BOOST_CHECK_EQUAL( tcp_header.get_header_length(), 10 ); // 10 words = 40 bytes
    BOOST_CHECK_EQUAL( tcp_header.get_congestion_window_reduced(), false );
    BOOST_CHECK_EQUAL( tcp_header.get_ecn_echo(), false );
    BOOST_CHECK_EQUAL( tcp_header.get_urgent(), false );
    BOOST_CHECK_EQUAL( tcp_header.get_acknowledgment(), false );
    BOOST_CHECK_EQUAL( tcp_header.get_push(), false );
    BOOST_CHECK_EQUAL( tcp_header.get_reset(), false );
    BOOST_CHECK_EQUAL( tcp_header.get_synchronize(), true );
    BOOST_CHECK_EQUAL( tcp_header.get_finish(), false );
    BOOST_CHECK_EQUAL( tcp_header.get_window_size(), 14600 );
    BOOST_CHECK_EQUAL( tcp_header.get_checksum(), 0xF727 );
}

BOOST_AUTO_TEST_CASE( rst_received )
{
    uint8_t raw_segment_stream[] = {
            0x00, 0x50, 0xe2, 0xc9, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
            0x01, 0x50, 0x14, 0x00, 0x00, 0x1e, 0x34, 0x00, 0x00
    };

    std::basic_stringbuf<uint8_t> sb;
    sb.pubsetbuf( raw_segment_stream, sizeof(raw_segment_stream) );
    std::basic_istream<uint8_t> is( &sb );

    TcpHeader tcp_header;
    reinterpret_cast<std::istream&>(is) >> tcp_header;

    BOOST_CHECK_EQUAL( tcp_header.get_source_port(), 80 );
    BOOST_CHECK_EQUAL( tcp_header.get_destination_port(), 58057 );
    BOOST_CHECK_EQUAL( tcp_header.get_sequence_number(), 0 ); // relative
    BOOST_CHECK_EQUAL( tcp_header.get_acknowledgment_number(), 1 );
    BOOST_CHECK_EQUAL( tcp_header.get_header_length(), 5 ); // 5 words = 20 bytes
    BOOST_CHECK_EQUAL( tcp_header.get_congestion_window_reduced(), false );
    BOOST_CHECK_EQUAL( tcp_header.get_ecn_echo(), false );
    BOOST_CHECK_EQUAL( tcp_header.get_urgent(), false );
    BOOST_CHECK_EQUAL( tcp_header.get_acknowledgment(), true );
    BOOST_CHECK_EQUAL( tcp_header.get_push(), false );
    BOOST_CHECK_EQUAL( tcp_header.get_reset(), true );
    BOOST_CHECK_EQUAL( tcp_header.get_synchronize(), false );
    BOOST_CHECK_EQUAL( tcp_header.get_finish(), false );
    BOOST_CHECK_EQUAL( tcp_header.get_window_size(), 0 );
    BOOST_CHECK_EQUAL( tcp_header.get_checksum(), 0x1E34 );
}

BOOST_AUTO_TEST_CASE( calculate_tcp_checksum_ipv4 )
{
    TcpHeader tcp_header;
    tcp_header.set_source_port( 58057 );
    tcp_header.set_destination_port( 80 );
    tcp_header.set_sequence_number( 0x0001 ); // relative
    tcp_header.set_acknowledgment_number( 0 );
    tcp_header.set_header_length( 5 ); // 5 words = 20 bytes
    tcp_header.set_congestion_window_reduced( false );
    tcp_header.set_ecn_echo( false );
    tcp_header.set_urgent( false );
    tcp_header.set_acknowledgment( true );
    tcp_header.set_push( false );
    tcp_header.set_reset( false );
    tcp_header.set_synchronize( false );
    tcp_header.set_finish( false );
    tcp_header.set_window_size( 32768 );

    boost::asio::ip::address_v4 src_addr = boost::asio::ip::address_v4::from_string( "192.168.1.102" );
    boost::asio::ip::address_v4 dst_addr = boost::asio::ip::address_v4::from_string( "200.147.35.224" );

    uint16_t checksum = tcp_header.calculate_tcp_checksum(
            src_addr.to_bytes(),
            dst_addr.to_bytes(),
            NULL, 0
    );

    BOOST_CHECK_EQUAL( checksum, 0x9E37 );
}

BOOST_AUTO_TEST_SUITE_END()