/***************************************************************************
 * 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                                                        */
/**                                                                       */
/**   Transmission Control Protocol (TCP)                                 */
/**                                                                       */
/**************************************************************************/
/**************************************************************************/

#define NX_SOURCE_CODE


/* Include necessary system files.  */

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


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

NX_CALLER_CHECKING_EXTERNS


/**************************************************************************/
/*                                                                        */
/*  FUNCTION                                               RELEASE        */
/*                                                                        */
/*    _nxe_tcp_free_port_find                             PORTABLE C      */
/*                                                           6.1          */
/*  AUTHOR                                                                */
/*                                                                        */
/*    Yuxin Zhou, Microsoft Corporation                                   */
/*                                                                        */
/*  DESCRIPTION                                                           */
/*                                                                        */
/*    This function checks for errors in the TCP free port find           */
/*    function call.                                                      */
/*                                                                        */
/*  INPUT                                                                 */
/*                                                                        */
/*    ip_ptr                                IP instance pointer           */
/*    port                                  Starting port                 */
/*    free_port_ptr                         Pointer to return free port   */
/*                                                                        */
/*  OUTPUT                                                                */
/*                                                                        */
/*    status                                Completion status             */
/*                                                                        */
/*  CALLS                                                                 */
/*                                                                        */
/*    _nx_tcp_free_port_find                Actual TCP free port find     */
/*                                            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_tcp_free_port_find(NX_IP *ip_ptr, UINT port, UINT *free_port_ptr)
{

UINT status;


    /* Check for invalid input pointers.  */
    if ((ip_ptr == NX_NULL) || (ip_ptr -> nx_ip_id != NX_IP_ID) || (free_port_ptr == NX_NULL))
    {
        return(NX_PTR_ERROR);
    }

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

    /* Check for an invalid port.  */
    if (((ULONG)port) > (ULONG)NX_MAX_PORT)
    {
        return(NX_INVALID_PORT);
    }

    /* Check for appropriate caller.  */
    NX_THREADS_ONLY_CALLER_CHECKING

    /* Call actual TCP free port find function.  */
    status =  _nx_tcp_free_port_find(ip_ptr, port, free_port_ptr);

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