/***************************************************************************
 * Copyright (c) 2024 Microsoft Corporation
 * Copyright (c) 2025-present Eclipse ThreadX Contributors
 *
 * 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                                                        */
/**                                                                       */
/**   Transmission Control Protocol (TCP)                                 */
/**                                                                       */
/**************************************************************************/
/**************************************************************************/

#define NX_SOURCE_CODE


/* Include necessary system files.  */

#include "nx_api.h"
#include "nx_tcp.h"


/* Bring in externs for caller checking code.  */

NX_CALLER_CHECKING_EXTERNS


/**************************************************************************/
/*                                                                        */
/*  FUNCTION                                               RELEASE        */
/*                                                                        */
/*    _nxe_tcp_socket_bytes_available                     PORTABLE C      */
/*                                                           6.4.3        */
/*  AUTHOR                                                                */
/*                                                                        */
/*    Yuxin Zhou, Microsoft Corporation                                   */
/*                                                                        */
/*  DESCRIPTION                                                           */
/*                                                                        */
/*    This function checks for errors in the TCP socket bytes             */
/*    available function call.                                            */
/*                                                                        */
/*  INPUT                                                                 */
/*                                                                        */
/*    socket_ptr                            Pointer to socket             */
/*    bytes_available                       Pointer to bytes available    */
/*                                                                        */
/*  OUTPUT                                                                */
/*                                                                        */
/*    status                                Completion status             */
/*                                                                        */
/*  CALLS                                                                 */
/*                                                                        */
/*    _nx_tcp_socket_bytes_available        Actual TCP socket bytes       */
/*                                            available function          */
/*                                                                        */
/*  CALLED BY                                                             */
/*                                                                        */
/*    Application                                                         */
/*                                                                        */
/**************************************************************************/
UINT  _nxe_tcp_socket_bytes_available(NX_TCP_SOCKET *socket_ptr, ULONG *bytes_available)
{

UINT status;


    /* Check for invalid input pointers.  */
    if ((socket_ptr == NX_NULL) ||
        (socket_ptr -> nx_tcp_socket_id != NX_TCP_ID) ||
        (bytes_available == NX_NULL))
    {
        return(NX_PTR_ERROR);
    }

    /* Check to see if TCP is enabled.  */
    if (!(socket_ptr -> nx_tcp_socket_ip_ptr) -> nx_ip_tcp_packet_receive)
    {
        return(NX_NOT_ENABLED);
    }

    /* Check for appropriate caller.  */
    NX_THREADS_ONLY_CALLER_CHECKING

    /* Call actual TCP socket receive function.  */
    status =  _nx_tcp_socket_bytes_available(socket_ptr, bytes_available);

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