/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * General purpose routine to see how much space something will use
 * when serialized using XDR.
 */
#include "mt.h"
#include <rpc/types.h>
#include <rpc/xdr.h>
#include <sys/types.h>
#include <stdlib.h>

/* ARGSUSED1 */
static bool_t
x_putlong(XDR *xdrs, long *ip)
{
        xdrs->x_handy += BYTES_PER_XDR_UNIT;
        return (TRUE);
}

#if defined(_LP64)
/* ARGSUSED1 */
static bool_t
x_putint32_t(XDR *xdrs, int32_t *ip)
{
        xdrs->x_handy += BYTES_PER_XDR_UNIT;
        return (TRUE);
}
#endif

/* ARGSUSED */
static bool_t
x_putbytes(XDR *xdrs, char *bp, int len)
{
        xdrs->x_handy += len;
        return (TRUE);
}

static uint_t
x_getpostn(XDR *xdrs)
{
        return (xdrs->x_handy);
}

/* ARGSUSED */
static bool_t
x_setpostn(XDR *xdrs, uint_t pos)
{
        /* This is not allowed */
        return (FALSE);
}

static rpc_inline_t *
x_inline(XDR *xdrs, int len)
{
        if (len == 0)
                return (NULL);
        if (xdrs->x_op != XDR_ENCODE)
                return (NULL);
        if (len < (intptr_t)xdrs->x_base) {
                /* x_private was already allocated */
                xdrs->x_handy += len;
                /* LINTED pointer cast */
                return ((rpc_inline_t *)xdrs->x_private);
        }
        /* Free the earlier space and allocate new area */
        if (xdrs->x_private)
                free(xdrs->x_private);
        if ((xdrs->x_private = malloc(len)) == NULL) {
                xdrs->x_base = 0;
                return (NULL);
        }
        xdrs->x_base = (caddr_t)(intptr_t)len;
        xdrs->x_handy += len;
        /* LINTED pointer cast */
        return ((rpc_inline_t *)xdrs->x_private);
}

static bool_t
harmless_getlong(XDR *xdr __unused, long *l __unused)
{
        /* Always return FALSE/NULL, as the case may be */
        return (FALSE);
}

static bool_t
harmless_getbytes(XDR *xdr __unused, caddr_t p __unused, int i __unused)
{
        return (FALSE);
}

#if defined(_LP64)
static bool_t
harmless_getint32(XDR *xdr __unused, int32_t *p __unused)
{
        return (FALSE);
}
#endif

static void
x_destroy(XDR *xdrs)
{
        xdrs->x_handy = 0;
        xdrs->x_base = 0;
        if (xdrs->x_private) {
                free(xdrs->x_private);
                xdrs->x_private = NULL;
        }
}

uint_t
xdr_sizeof(xdrproc_t func, void *data)
{
        XDR x;
        struct xdr_ops ops;
        bool_t stat;
        /* to stop ANSI-C compiler from complaining */

        ops.x_putlong = x_putlong;
        ops.x_getlong =  harmless_getlong;
        ops.x_putbytes = x_putbytes;
        ops.x_inline = x_inline;
        ops.x_getpostn = x_getpostn;
        ops.x_setpostn = x_setpostn;
        ops.x_destroy = x_destroy;
#if defined(_LP64)
        ops.x_getint32 = harmless_getint32;
        ops.x_putint32 = x_putint32_t;
#endif

        /* the other harmless ones */
        ops.x_getbytes = harmless_getbytes;

        x.x_op = XDR_ENCODE;
        x.x_ops = &ops;
        x.x_handy = 0;
        x.x_private = NULL;
        x.x_base = NULL;

        stat = func(&x, data);
        if (x.x_private)
                free(x.x_private);
        return (stat == TRUE ? (uint_t)x.x_handy : 0);
}