/*

* Copyright (c) 2006-2007 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:  Class for parsing Ethernet frames

*

*/

#include "core_frame_ethernet.h"

#include "core_tools.h"

#include "am_debug.h"

const u16_t CORE_ETHERNET_MIN_LENGTH = 14;

const u16_t CORE_ETHERNET_DESTINATION_INDEX = 0;

const u16_t CORE_ETHERNET_SOURCE_INDEX = 6;

const u16_t CORE_ETHERNET_TYPE_INDEX = 12;

// ---------------------------------------------------------------------------

// ---------------------------------------------------------------------------

//

core_frame_ethernet_c* core_frame_ethernet_c::instance(

    u16_t data_length,

    const u8_t* data,

    bool_t is_copied )

    {

    DEBUG( "core_frame_ethernet_c::instance()" );

    DEBUG1( "core_frame_ethernet_c::instance() - is_copied %u",

        is_copied );   

    if ( data_length < CORE_ETHERNET_MIN_LENGTH )

        {

        DEBUG( "core_frame_ethernet_c::instance() - not a valid Ethernet frame, frame is too short" );

        return NULL;

        }

    u8_t* buffer = const_cast<u8_t*>( data );

    u16_t buffer_length( 0 );

    if ( is_copied )

        {

        buffer_length = data_length;

        buffer = new u8_t[buffer_length];

        if ( !buffer )

            {

            DEBUG( "core_frame_ethernet_c::instance() - not able to allocate buffer for copying" );

            return NULL;            

            }

        core_tools_c::copy(

            buffer,

            data,

            buffer_length );

        }

    core_frame_ethernet_c* instance = new core_frame_ethernet_c(

        data_length,

        buffer,

        buffer_length );

    if ( !instance )

        {

        DEBUG( "core_frame_ethernet_c::instance() - unable to create an instance" );

        if ( is_copied )

            {

            delete[] buffer;

            }

        return NULL;

        }

    return instance;

    }

// ---------------------------------------------------------------------------

// ---------------------------------------------------------------------------

// 

core_frame_ethernet_c* core_frame_ethernet_c::instance(

    u16_t max_data_length,

    const core_mac_address_s& destination,

    const core_mac_address_s& source,

    u16_t type )

    {

    DEBUG( "core_frame_ethernet_c::instance()" );

    u8_t* buffer = new u8_t[max_data_length];

    if ( !buffer )

        {

        DEBUG( "core_frame_ethernet_c::instance() - unable create the internal buffer" );

        }

    core_frame_ethernet_c* instance =

        new core_frame_ethernet_c( 0, buffer, max_data_length );

    if ( !instance )

        {

        DEBUG( "core_frame_ethernet_c::instance() - unable to create an instance" );

        delete[] buffer;

        return NULL;

        }

    instance->generate(

        destination,

        source,

        type );

    return instance;

    }

// ---------------------------------------------------------------------------

// ---------------------------------------------------------------------------

//      

core_frame_ethernet_c::~core_frame_ethernet_c()

    {

    DEBUG( "core_frame_ethernet_c::~core_frame_ethernet_c" );

    /** 

     * If maximum frame length has been defined, we have allocated

     * the frame buffer ourselves.

     */    

    if ( max_data_length_m )

        {

        delete[] data_m;

        }    

    data_m = NULL;

    }

// ---------------------------------------------------------------------------

// ---------------------------------------------------------------------------

//

core_mac_address_s core_frame_ethernet_c::destination() const

    {

    return mac_address( CORE_ETHERNET_DESTINATION_INDEX );

    }

// ---------------------------------------------------------------------------

// ---------------------------------------------------------------------------

//

core_mac_address_s core_frame_ethernet_c::source() const

    {

    return mac_address( CORE_ETHERNET_SOURCE_INDEX );

    }

// ---------------------------------------------------------------------------

// ---------------------------------------------------------------------------

//

u16_t core_frame_ethernet_c::type() const

    {

    return core_tools_c::get_u16_big_endian( data_m, CORE_ETHERNET_TYPE_INDEX );

    }

// ---------------------------------------------------------------------------

// ---------------------------------------------------------------------------

//

core_mac_address_s core_frame_ethernet_c::mac_address(

    u16_t index ) const

    {

    core_mac_address_s mac( ZERO_MAC_ADDR );

    core_tools_c::copy(

        &mac.addr[0],

        &data_m[index],

        MAC_ADDR_LEN );

    return mac;

    }

// ---------------------------------------------------------------------------

// ---------------------------------------------------------------------------

//

u16_t core_frame_ethernet_c::data_length() const

    {

    return data_length_m;

    }

// ---------------------------------------------------------------------------

// ---------------------------------------------------------------------------

//   

const u8_t* core_frame_ethernet_c::data() const

    {

    return data_m;

    }

// ---------------------------------------------------------------------------

// ---------------------------------------------------------------------------

//

u16_t core_frame_ethernet_c::payload_data_length() const

    {

    return data_length_m - CORE_ETHERNET_MIN_LENGTH;

    }

// ---------------------------------------------------------------------------

// ---------------------------------------------------------------------------

//

const u8_t* core_frame_ethernet_c::payload_data() const

    {

    return data_m + CORE_ETHERNET_MIN_LENGTH;

    }

// ---------------------------------------------------------------------------

// ---------------------------------------------------------------------------

//

void core_frame_ethernet_c::core_frame_ethernet_c::generate(

    const core_mac_address_s& destination,

    const core_mac_address_s& source,

    u16_t type )

    {

    ASSERT( !data_length_m );

    ASSERT( max_data_length_m );   

    // Destination MAC

    core_tools_c::copy(

        &data_m[data_length_m],

        &destination.addr[0],

        MAC_ADDR_LEN );

    data_length_m += MAC_ADDR_LEN;        

    // Source MAC

    core_tools_c::copy(

        &data_m[data_length_m],

        &source.addr[0],

        MAC_ADDR_LEN );

    data_length_m += MAC_ADDR_LEN;    

    // Ethernet Type

    u16_t temp16 = core_tools_c::convert_host_to_big_endian(

        type  );

    core_tools_c::copy(

        &data_m[data_length_m],

        reinterpret_cast<u8_t*>( &temp16 ),

        sizeof( temp16 ) );

    data_length_m += sizeof( temp16 );

    }

// ---------------------------------------------------------------------------

// ---------------------------------------------------------------------------

//

core_frame_ethernet_c::core_frame_ethernet_c(

    u16_t data_length,

    const u8_t* data,

    u16_t max_data_length ) :

    data_length_m( data_length ),

    data_m( NULL ),

    max_data_length_m( max_data_length )

    {

    DEBUG( "core_frame_ethernet_c::core_frame_ethernet_c" );

    /**

     * The reason the const is discarded is that the same pointer

     * is used when we have allocated the frame buffer ourselves.

     */

    data_m = const_cast<u8_t*>( data );

    }