/***************************************************************************
 * Copyright (c) 2024 Microsoft Corporation 
 * 
 * This program and the accompanying materials are made available under the
 * terms of the MIT License which is available at
 * https://opensource.org/licenses/MIT.
 * 
 * SPDX-License-Identifier: MIT
 **************************************************************************/


/**************************************************************************/
/**************************************************************************/
/**                                                                       */
/** NetX Component                                                        */
/**                                                                       */
/**   Packet Pool Management (Packet)                                     */
/**                                                                       */
/**************************************************************************/
/**************************************************************************/

#define NX_SOURCE_CODE


/* Include necessary system files.  */

#include "nx_api.h"
#include "nx_packet.h"


/**************************************************************************/
/*                                                                        */
/*  FUNCTION                                               RELEASE        */
/*                                                                        */
/*    _nxe_packet_release                                 PORTABLE C      */
/*                                                           6.1          */
/*  AUTHOR                                                                */
/*                                                                        */
/*    Yuxin Zhou, Microsoft Corporation                                   */
/*                                                                        */
/*  DESCRIPTION                                                           */
/*                                                                        */
/*    This function checks for errors in the packet release               */
/*    function call.                                                      */
/*                                                                        */
/*  INPUT                                                                 */
/*                                                                        */
/*    packet_ptr                            Pointer of packet to release  */
/*                                                                        */
/*  OUTPUT                                                                */
/*                                                                        */
/*    status                                Completion status             */
/*                                                                        */
/*  CALLS                                                                 */
/*                                                                        */
/*    _nx_packet_release                    Actual packet release         */
/*                                            function                    */
/*                                                                        */
/*  CALLED BY                                                             */
/*                                                                        */
/*    Application Code                                                    */
/*                                                                        */
/*  RELEASE HISTORY                                                       */
/*                                                                        */
/*    DATE              NAME                      DESCRIPTION             */
/*                                                                        */
/*  05-19-2020     Yuxin Zhou               Initial Version 6.0           */
/*  09-30-2020     Yuxin Zhou               Modified comment(s),          */
/*                                            resulting in version 6.1    */
/*                                                                        */
/**************************************************************************/
UINT  _nxe_packet_release(NX_PACKET **packet_ptr_ptr)
{

UINT       status;
NX_PACKET *packet_ptr;


    /* Setup packet pointer.  */
    packet_ptr =  *packet_ptr_ptr;

    /* Simple integrity check on the packet.  */
    if ((packet_ptr == NX_NULL) || (packet_ptr -> nx_packet_pool_owner == NX_NULL) ||
        ((packet_ptr -> nx_packet_pool_owner) -> nx_packet_pool_id != NX_PACKET_POOL_ID))
    {

        return(NX_PTR_ERROR);
    }

    /* Check for an invalid packet prepend pointer.  */
    /*lint -e{946} suppress pointer subtraction, since it is necessary. */
    if (packet_ptr -> nx_packet_prepend_ptr < packet_ptr -> nx_packet_data_start)
    {
        return(NX_UNDERFLOW);
    }

    /* Check for an invalid packet append pointer.  */
    /*lint -e{946} suppress pointer subtraction, since it is necessary. */
    if (packet_ptr -> nx_packet_append_ptr > packet_ptr -> nx_packet_data_end)
    {
        return(NX_OVERFLOW);
    }

    /* Call actual packet release function.  */
    status =  _nx_packet_release(packet_ptr);

    /* Determine if the packet release was successful.  */
    if (status == NX_SUCCESS)
    {

        /* Yes, now clear the application's packet pointer so it can't be accidentally
           used again by the application.  This is only done when error checking is
           enabled.  */
        *packet_ptr_ptr =  NX_NULL;
    }

    /* Return completion status.  */
    return(status);
}