/*
 * 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 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */
/* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/*
 * Portions of this source code were derived from Berkeley
 * 4.3 BSD under license from the Regents of the University of
 * California.
 */

/*
 * xdr_mem.h, XDR implementation using memory buffers.
 *
 * If you have some data to be interpreted as external data representation
 * or to be converted to external data representation in a memory buffer,
 * then this is the package for you.
 */

#include "mt.h"
#include "rpc_mt.h"
#include <sys/types.h>
#include <rpc/types.h>
#include <rpc/xdr.h>
#include <memory.h>
#include <inttypes.h>

static struct xdr_ops *xdrmem_ops(void);

/*
 * Meaning of the private areas of the xdr struct for xdr_mem
 *      x_base : Base from where the xdr stream starts
 *      x_private : The current position of the stream.
 *      x_handy : The size of the stream buffer.
 */

/*
 * The procedure xdrmem_create initializes a stream descriptor for a
 * memory buffer.
 */
void
xdrmem_create(XDR *xdrs, const caddr_t addr, const uint_t size,
                                                        const enum xdr_op op)
{
        caddr_t eaddr = addr;

        xdrs->x_op = op;
        xdrs->x_ops = xdrmem_ops();
        xdrs->x_private = xdrs->x_base = 0;
        /*
         * We check here that the size is with in the range of the
         * address space. If not we set x_handy to zero. This will cause
         * all xdrmem entry points to fail.
         */
        eaddr = addr + size;

        if (eaddr < addr)
                xdrs->x_handy = 0;
        else {
                xdrs->x_handy = size;
                xdrs->x_private = xdrs->x_base = addr;
        }
}

/* ARGSUSED */
static void
xdrmem_destroy(XDR *xdrs)
{
}

static bool_t
xdrmem_getlong(XDR *xdrs, long *lp)
{
        if (sizeof (int32_t) > (uint32_t)xdrs->x_handy) {
                xdrs->x_private += (uint_t)xdrs->x_handy;
                xdrs->x_handy = 0;
                return (FALSE);
        }
        xdrs->x_handy -= sizeof (int32_t);
        /* LINTED pointer cast */
        *lp = (int32_t)ntohl((uint32_t)(*((int32_t *)(xdrs->x_private))));
        xdrs->x_private += sizeof (int32_t);
        return (TRUE);
}

static bool_t
xdrmem_putlong(XDR *xdrs, long *lp)
{
#if defined(_LP64)
        if ((*lp > INT32_MAX) || (*lp < INT32_MIN))
                return (FALSE);
#endif

        if ((sizeof (int32_t) > (uint32_t)xdrs->x_handy)) {
                xdrs->x_private += (uint_t)xdrs->x_handy;
                xdrs->x_handy = 0;
                return (FALSE);
        }
        xdrs->x_handy -= sizeof (int32_t);
        /* LINTED pointer cast */
        *(int32_t *)xdrs->x_private = (int32_t)htonl((uint32_t)(*lp));
        xdrs->x_private += sizeof (int32_t);
        return (TRUE);
}

#if defined(_LP64)
static bool_t
xdrmem_getint32(XDR *xdrs, int32_t *ip)
{
        if (sizeof (int32_t) > (uint_t)xdrs->x_handy) {
                xdrs->x_private += (uint_t)xdrs->x_handy;
                xdrs->x_handy = 0;
                return (FALSE);
        }
        xdrs->x_handy -= sizeof (int32_t);
        /* LINTED pointer cast */
        *ip = (int32_t)ntohl((uint32_t)(*((int32_t *)(xdrs->x_private))));
        xdrs->x_private += sizeof (int32_t);
        return (TRUE);
}

static bool_t
xdrmem_putint32(XDR *xdrs, int32_t *ip)
{
        if (sizeof (int32_t) > (uint32_t)xdrs->x_handy) {
                xdrs->x_private += (uint_t)xdrs->x_handy;
                xdrs->x_handy = 0;
                return (FALSE);
        }
        xdrs->x_handy -= sizeof (int32_t);
        /* LINTED pointer cast */
        *(int32_t *)xdrs->x_private = (int32_t)htonl((uint32_t)(*ip));
        xdrs->x_private += sizeof (int32_t);
        return (TRUE);
}
#endif /* _LP64 */

static bool_t
xdrmem_getbytes(XDR *xdrs, caddr_t addr, int len)
{
        if ((uint32_t)len > (uint32_t)xdrs->x_handy) {
                xdrs->x_private += (uint_t)xdrs->x_handy;
                xdrs->x_handy = 0;
                return (FALSE);
        }
        xdrs->x_handy -= len;
        (void) memcpy(addr, xdrs->x_private, (uint_t)len);
        xdrs->x_private += (uint_t)len;
        return (TRUE);
}

static bool_t
xdrmem_putbytes(XDR *xdrs, caddr_t addr, int len)
{
        if ((uint32_t)len > (uint32_t)xdrs->x_handy) {
                xdrs->x_private += (uint_t)xdrs->x_handy;
                xdrs->x_handy = 0;
                return (FALSE);
        }
        xdrs->x_handy -= len;
        (void) memcpy(xdrs->x_private, addr, (uint_t)len);
        xdrs->x_private += (uint_t)len;
        return (TRUE);
}

static uint_t
xdrmem_getpos(XDR *xdrs)
{
        return (uint_t)((uintptr_t)xdrs->x_private - (uintptr_t)xdrs->x_base);
}

static bool_t
xdrmem_setpos(XDR *xdrs, uint_t pos)
{
        caddr_t newaddr = xdrs->x_base + pos;
        caddr_t lastaddr = xdrs->x_private + (uint_t)xdrs->x_handy;

        if ((long)newaddr > (long)lastaddr)
                return (FALSE);
        xdrs->x_private = newaddr;
        xdrs->x_handy = (int)((uintptr_t)lastaddr - (uintptr_t)newaddr);
        return (TRUE);
}

static rpc_inline_t *
xdrmem_inline(XDR *xdrs, int len)
{
        rpc_inline_t *buf = 0;

        if ((uint32_t)xdrs->x_handy >= (uint32_t)len) {
                xdrs->x_handy -= len;
                /* LINTED pointer cast */
                buf = (rpc_inline_t *)xdrs->x_private;
                xdrs->x_private += (uint_t)len;
        }
        return (buf);
}

static bool_t
xdrmem_control(XDR *xdrs, int request, void *info)
{
        xdr_bytesrec *xptr;

        switch (request) {
        case XDR_GET_BYTES_AVAIL:
                xptr = (xdr_bytesrec *) info;
                xptr->xc_is_last_record = TRUE;
                xptr->xc_num_avail = xdrs->x_handy;
                return (TRUE);
        default:
                return (FALSE);

        }

}

static struct xdr_ops *
xdrmem_ops(void)
{
        static struct xdr_ops ops;
        extern mutex_t  ops_lock;

/* VARIABLES PROTECTED BY ops_lock: ops */
        (void) mutex_lock(&ops_lock);
        if (ops.x_getlong == NULL) {
                ops.x_getlong = xdrmem_getlong;
                ops.x_putlong = xdrmem_putlong;
                ops.x_getbytes = xdrmem_getbytes;
                ops.x_putbytes = xdrmem_putbytes;
                ops.x_getpostn = xdrmem_getpos;
                ops.x_setpostn = xdrmem_setpos;
                ops.x_inline = xdrmem_inline;
                ops.x_destroy = xdrmem_destroy;
                ops.x_control = xdrmem_control;
#if defined(_LP64)
                ops.x_getint32 = xdrmem_getint32;
                ops.x_putint32 = xdrmem_putint32;
#endif
        }
        (void) mutex_unlock(&ops_lock);
        return (&ops);
}