/*
* 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 "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:   
*
*/




/*
    Destination Unreachable Message:

   0                   1                   2                   3
   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |     Type      |     Code      |          Checksum             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                             Unused                            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                    As much of invoking packet                 |
   +                as will fit without the ICMPv6 packet          +
   |                exceeding the minimum IPv6 MTU [IPv6]          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


    IPv6 Header Format:

     0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |Version| Traffic Class |           Flow Label                  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |         Payload Length        |  Next Header  |   Hop Limit   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   +                                                               +
   |                                                               |
   +                         Source Address                        +
   |                                                               |
   +                                                               +
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   +                                                               +
   |                                                               |
   +                      Destination Address                      +
   |                                                               |
   +                                                               +
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


Extension Header Format:

   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  Next Header  |  Hdr Ext Len  |                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                               +
   |                                                               |
   .                                                               .
   .             type-specific data (variable length)              .
   .                                                               .
   .                                                               .
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


User datagram:

                 0      7 8     15 16    23 24    31
                 +--------+--------+--------+--------+
                 |     Source      |   Destination   |
                 |      Port       |      Port       |
                 +--------+--------+--------+--------+
                 |                 |                 |
                 |     Length      |    Checksum     |
                 +--------+--------+--------+--------+
                 |
                 |          data octets ...
                 +---------------- ...


    In the code the data is located in 8-bit pieces.
*/

#include <ip6_hdr.h>
#include <icmp6_hdr.h>
#include <udp_hdr.h>
#include <ext_hdr.h>
#include <in_sock.h>
#include "natfwunsaflog.h"
#include "cnatfwunsaficmpv6receiver.h"
#include "mnatfwunsaficmperrorobserver.h"


// -----------------------------------------------------------------------------
// CIcmpV6Receiver::NewL
// -----------------------------------------------------------------------------
//
CIcmpV6Receiver* CIcmpV6Receiver::NewL( MIcmpErrorObserver& aObserver,
                                        RSocketServ& aServer )
    {
    CIcmpV6Receiver* self =
        new ( ELeave ) CIcmpV6Receiver( aObserver, aServer );
    CleanupStack::PushL( self );
    self->ConstructL();
    CleanupStack::Pop( self );
    return self;
    }

// -----------------------------------------------------------------------------
// CIcmpV6Receiver::CIcmpV6Receiver
// -----------------------------------------------------------------------------
//
CIcmpV6Receiver::CIcmpV6Receiver(MIcmpErrorObserver& aObserver,
                                 RSocketServ& aServer) :
    CActive( CActive::EPriorityStandard ),
    iServer( aServer ),
    iObserver( aObserver )
    {
    CActiveScheduler::Add( this );
    }

// -----------------------------------------------------------------------------
// CIcmpV6Receiver::ConstructL
// -----------------------------------------------------------------------------
//
void CIcmpV6Receiver::ConstructL()
    {
    User::LeaveIfError( iSocket.Open( iServer,
                                      KAfInet,
                                      KSockDatagram,
                                      KProtocolInet6Icmp ) );
    Receive();
    }

// -----------------------------------------------------------------------------
// CIcmpV6Receiver::~CIcmpV6Receiver
// -----------------------------------------------------------------------------
//
CIcmpV6Receiver::~CIcmpV6Receiver()
    {
    Cancel();
    iSocket.Close();
    }

// -----------------------------------------------------------------------------
// CIcmpV6Receiver::RunL
// -----------------------------------------------------------------------------
//
void CIcmpV6Receiver::RunL()
    {
    if ( iStatus == KErrNone )
        {
        CheckError();
        Receive();
        }
    }

// Disabled PC-Lint warning for "Suspicious pointer-to-pointer conversion
// (area too small))". It was caused by TUin8* to TInet6xxx typecasts and could
// not be avoided otherwise.
/*lint -e826 */

// -----------------------------------------------------------------------------
// CIcmpV6Receiver::CheckError
// -----------------------------------------------------------------------------
//
void CIcmpV6Receiver::CheckError()
    {
    const TUint KDestinationUnreachable = 1;

    // Pointer to ICMP header
    TInet6HeaderICMP* icmpPtr = ( TInet6HeaderICMP* ) iData.Ptr();

    // Pointer to IPv6 header
    const TInt KIPHeaderOffset = 8;
    TInet6HeaderIP* ipv6Ptr =
        ( TInet6HeaderIP* )( iData.Ptr() + KIPHeaderOffset );

    // Get the whole length of the header in bytes
    TUint32 payloadLength = ipv6Ptr->PayloadLength();
    TUint32 offset = 0;

    // Pointer to IPv6 extension header
    const TInt KExtHeaderOffset = 14;
    TInet6HeaderExtension* extPtr =
        ( TInet6HeaderExtension* )( iData.Ptr() + KExtHeaderOffset );
    // Get the extension header length in bytes
    TUint32 extHdrLength = extPtr->HeaderLength();

    // Pointer to UDP data
    TInet6HeaderUDP* udpPtr = ( TInet6HeaderUDP* )( ipv6Ptr->EndPtr() );

    // Error message type
    TUint32 error = icmpPtr->Type();
    if( error == KDestinationUnreachable )
        {
        TUint32 nextHeader = 0;
        do  // Search the correct header, if there are extension headers
            {
            nextHeader = extPtr->NextHeader();
            if( nextHeader == KProtocolInetUdp )
                {
                // Get the destination port number
                iAddress.SetPort( udpPtr->DstPort() );

                // Set the destination address
                iAddress.SetAddress( ipv6Ptr->DstAddr() );

                NATFWUNSAF_INTLOG( "CIcmpV6Receiver, ICMP error:", error )
                NATFWUNSAF_ADDRLOG( "DstAddr:", iAddress )

                iObserver.IcmpError( iAddress );
                }
            else
                {
                // Step to next header
                if( offset < payloadLength )
                    {
                    extPtr = extPtr + extHdrLength;
                    offset = offset + extHdrLength;
                    }
                }
            // Loop until UDP datagram is found. If it is not found,
            // get out of here and do nothing.
            } while ( ( nextHeader != KProtocolInetUdp ) &&
                      ( offset < payloadLength ) );
        }
    }

// -----------------------------------------------------------------------------
// CIcmpV6Receiver::DoCancel
// -----------------------------------------------------------------------------
//
void CIcmpV6Receiver::DoCancel()
    {
    iSocket.CancelRecv();
    }

// -----------------------------------------------------------------------------
// CIcmpV6Receiver::Receive
// -----------------------------------------------------------------------------
//
void CIcmpV6Receiver::Receive()
    {
    if ( !IsActive() )
        {
        iSocket.Recv( iData, 0, iStatus );
        SetActive();
        }
    }