/*
 ******************************************************************************
 *                     INTERPEAK SOURCE FILE
 *
 *   Document no: @(#) $Name: VXWORKS_ITER40_2019102207 $ $RCSfile: ipl2tp_v2_pw.c,v $ $Revision: 1.5.16.1 $
 *   $Source: /home/interpeak/CVSRoot/ipl2tp/src/ipl2tp_v2_pw.c,v $
 *   $Author: jren $
 *   $State: Exp $ $Locker:  $
 *
 *   INTERPEAK_COPYRIGHT_STRING
 *     Design and implementation by Joel Hortelius <joel.hortelis@interpeak.se>
 ******************************************************************************
 */


/*
 ****************************************************************************
 * 1                    DESCRIPTION
 ****************************************************************************
 */

/*
 ****************************************************************************
 * 2                    CONFIGURATION
 ****************************************************************************
 */

/*
 ****************************************************************************
 * 3                    INCLUDE FILES
 ****************************************************************************
 */
#include "ipl2tp_h.h"
#include "ipl2tp_api.h"
#include "ipl2tp_avp.h"
#include "ipl2tp_data.h"
#include "ipl2tp_message.h"
#include "ipl2tp_state.h"
#include "ipl2tp_pseudowire.h"
#include "ipl2tp_trpt.h"

#include "ipl2tp_v2.h"
#include "ipl2tp_v2_state.h"
#include "ipl2tp_v2_pw.h"

/*
 ****************************************************************************
 * 4                    DEFINES
 ****************************************************************************
 */

/*
 ****************************************************************************
 * 5                    TYPES
 ****************************************************************************
 */

/*
 ****************************************************************************
 * 6                    EXTERN PROTOTYPES
 ****************************************************************************
 */

/*
 ****************************************************************************
 * 7                    LOCAL PROTOTYPES
 ****************************************************************************
 */

/*
 ****************************************************************************
 * 8                    DATA
 ****************************************************************************
 */

/*
 ****************************************************************************
 * 9                    STATIC FUNCTIONS
 ****************************************************************************
 */

/*
 ****************************************************************************
 * 10                   GLOBAL FUNCTIONS
 ****************************************************************************
 */


/*
 *===========================================================================
 *                    ipl2tp_v2_pw_ppp_input
 *===========================================================================
 * Description: Feed an incoming PPP packet to the IPL2TP engine.
 * Parameters:  session - The session which the packet belongs to.
 *              buffer  - PPP packet.
 *              length  - Length of PPP packet.
 *              offset  - Number of bytes before 'buffer' that may be used.
 *              align   - Alignment requirement for output buffer.
 * Returns:     IPL2TP_STATUS_OK if success.
 *              IPL2TP_STATUS_BADID if invalid session ID.
 */
IP_GLOBAL Ipl2tp_status 
ipl2tp_v2_pw_ppp_input(Ipl2tp_session     *session,
                       void               *buffer,
                       int                length, 
                       int                offset, 
                       int                align)
{
    Ipl2tp_tunnel       *tunnel     = session->tunnel;
    Ipl2tp_v2_umessage  *message;
    int                 rhsize = 8;
    int                 hsize;
    Ip_u16              flv;
    struct Ip_iovec     iov[2];
    int                 iov_len = 0;
    char                hdr[32];


    /* Sequencing required? */
    if (session->v.v2.sequencing != 0)
    {
        rhsize += 4;
    }

    /* Remember min header size */
    hsize = rhsize;

    /* Check alignment */
#ifdef IPL2TP_V2_STRICT_HEADER_ALIGNMENT
    if ((((int)buffer - hsize) % align) != 0)
    {
        hsize += 2;
        hsize += (((int)buffer - hsize) % align);
    }
#endif

    /* Header fits in allocated offset? */
    if (hsize > offset)
    {
        iov[iov_len].iov_base = hdr;
        iov[iov_len].iov_len  = hsize;
        iov_len++;

        iov[iov_len].iov_base = buffer;
        iov[iov_len].iov_len  = length;
        iov_len++;

        message = (Ipl2tp_v2_umessage *) hdr;
    }
    else
    {
        Ip_u8   *frame  = buffer;

        message = (Ipl2tp_v2_umessage *)(frame - hsize);

        iov[iov_len].iov_base = message;
        iov[iov_len].iov_len  = length + hsize;
        iov_len++;
    }

    /* Enter header fields */
    flv = IPL2TP_HEADER_FLAG_LENGTH;
    flv |= IPL2TP_VERSION_L2TPV2;

    IP_SET_HTONS(&message->len_seq.length,      (hsize + length));
    IP_SET_HTONS(&message->len_seq.tunnel_id,   ((Ip_u16) (tunnel->remote.key.ident)));
    IP_SET_HTONS(&message->len_seq.session_id,  ((Ip_u16) (session->remote.key.ident)));

    /* Enter sequence number */
    if (session->v.v2.sequencing != 0)
    {
        Ip_u16 seq = session->v.v2.ns++;

        flv |= IPL2TP_HEADER_FLAG_SEQUENCE;
        IP_SET_HTONS(&message->len_seq.ns, seq);
        message->len_seq.nr = 0;
    }

#ifdef IPL2TP_V2_STRICT_HEADER_ALIGNMENT
    /* Enter offset */
    if (hsize != rhsize)
    {
        flv |= IPL2TP_HEADER_FLAG_OFFSET;

        if (session->v.v2.sequencing == 0)
        {
            IP_SET_HTONS(&message->len_off.offset,
                         hsize - sizeof(message->len_off));
        }
        else
        {
            IP_SET_HTONS(&message->len_seq_off.offset,
                         hsize - sizeof(message->len_seq_off));
        }
    }
#endif
    IP_SET_HTONS(&message->len_seq.flv, flv);

    ipl2tp_trpt_data_output(tunnel, 
                            iov,
                            iov_len);

    return IPL2TP_STATUS_OK;           
}

/*
 ****************************************************************************
 * 11                   PUBLIC FUNCTIONS
 ****************************************************************************
 */

/*
 ****************************************************************************
 *                      END OF FILE
 ****************************************************************************
 */