/*      $NetBSD: xdr_mem.c,v 1.15 2000/01/22 22:19:18 mycroft Exp $     */

/*
 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
 * unrestricted use provided that this legend is included on all tape
 * media and as a part of the software program in whole or part.  Users
 * may copy or modify Sun RPC without charge, but are not authorized
 * to license or distribute it to anyone else except as part of a product or
 * program developed by the user.
 *
 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
 *
 * Sun RPC is provided with no support and without any obligation on the
 * part of Sun Microsystems, Inc. to assist in its use, correction,
 * modification or enhancement.
 *
 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
 * OR ANY PART THEREOF.
 *
 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
 * or profits or other special, indirect and consequential damages, even if
 * Sun has been advised of the possibility of such damages.
 *
 * Sun Microsystems, Inc.
 * 2550 Garcia Avenue
 * Mountain View, California  94043
 */

#include <sys/cdefs.h>
/*
 * xdr_mem.h, XDR implementation using memory buffers.
 *
 * Copyright (C) 1984, Sun Microsystems, Inc.
 *
 * 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 <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>

#include <rpc/types.h>
#include <rpc/xdr.h>

static void xdrmem_destroy(XDR *);
static bool_t xdrmem_getlong_aligned(XDR *, long *);
static bool_t xdrmem_putlong_aligned(XDR *, const long *);
static bool_t xdrmem_getlong_unaligned(XDR *, long *);
static bool_t xdrmem_putlong_unaligned(XDR *, const long *);
static bool_t xdrmem_getbytes(XDR *, char *, u_int);
static bool_t xdrmem_putbytes(XDR *, const char *, u_int);
static bool_t xdrmem_putmbuf(XDR *, struct mbuf *);
/* XXX: w/64-bit pointers, u_int not enough! */
static u_int xdrmem_getpos(XDR *);
static bool_t xdrmem_setpos(XDR *, u_int);
static int32_t *xdrmem_inline_aligned(XDR *, u_int);
static int32_t *xdrmem_inline_unaligned(XDR *, u_int);
static bool_t xdrmem_control(XDR *xdrs, int request, void *info);

static const struct     xdr_ops xdrmem_ops_aligned = {
        .x_getlong =    xdrmem_getlong_aligned,
        .x_putlong =    xdrmem_putlong_aligned,
        .x_getbytes =   xdrmem_getbytes,
        .x_putbytes =   xdrmem_putbytes,
        .x_putmbuf =    xdrmem_putmbuf,
        .x_getpostn =   xdrmem_getpos,
        .x_setpostn =   xdrmem_setpos,
        .x_inline =     xdrmem_inline_aligned,
        .x_destroy =    xdrmem_destroy,
        .x_control =    xdrmem_control,
};

static const struct     xdr_ops xdrmem_ops_unaligned = {
        .x_getlong =    xdrmem_getlong_unaligned,
        .x_putlong =    xdrmem_putlong_unaligned,
        .x_getbytes =   xdrmem_getbytes,
        .x_putbytes =   xdrmem_putbytes,
        .x_putmbuf =    xdrmem_putmbuf,
        .x_getpostn =   xdrmem_getpos,
        .x_setpostn =   xdrmem_setpos,
        .x_inline =     xdrmem_inline_unaligned,
        .x_destroy =    xdrmem_destroy,
        .x_control =    xdrmem_control
};

/*
 * The procedure xdrmem_create initializes a stream descriptor for a
 * memory buffer.
 */
void
xdrmem_create(XDR *xdrs, char *addr, u_int size, enum xdr_op op)
{

        xdrs->x_op = op;
        xdrs->x_ops = ((unsigned long)addr & (sizeof(int32_t) - 1))
            ? &xdrmem_ops_unaligned : &xdrmem_ops_aligned;
        xdrs->x_private = xdrs->x_base = addr;
        xdrs->x_handy = size;
}

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

}

static bool_t
xdrmem_getlong_aligned(XDR *xdrs, long *lp)
{

        if (xdrs->x_handy < sizeof(int32_t))
                return (FALSE);
        xdrs->x_handy -= sizeof(int32_t);
        *lp = ntohl(*(uint32_t *)xdrs->x_private);
        xdrs->x_private = (char *)xdrs->x_private + sizeof(int32_t);
        return (TRUE);
}

static bool_t
xdrmem_putlong_aligned(XDR *xdrs, const long *lp)
{

        if (xdrs->x_handy < sizeof(int32_t))
                return (FALSE);
        xdrs->x_handy -= sizeof(int32_t);
        *(uint32_t *)xdrs->x_private = htonl((uint32_t)*lp);
        xdrs->x_private = (char *)xdrs->x_private + sizeof(int32_t);
        return (TRUE);
}

static bool_t
xdrmem_getlong_unaligned(XDR *xdrs, long *lp)
{
        uint32_t l;

        if (xdrs->x_handy < sizeof(int32_t))
                return (FALSE);
        xdrs->x_handy -= sizeof(int32_t);
        memmove(&l, xdrs->x_private, sizeof(int32_t));
        *lp = ntohl(l);
        xdrs->x_private = (char *)xdrs->x_private + sizeof(int32_t);
        return (TRUE);
}

static bool_t
xdrmem_putlong_unaligned(XDR *xdrs, const long *lp)
{
        uint32_t l;

        if (xdrs->x_handy < sizeof(int32_t))
                return (FALSE);
        xdrs->x_handy -= sizeof(int32_t);
        l = htonl((uint32_t)*lp);
        memmove(xdrs->x_private, &l, sizeof(int32_t));
        xdrs->x_private = (char *)xdrs->x_private + sizeof(int32_t);
        return (TRUE);
}

static bool_t
xdrmem_getbytes(XDR *xdrs, char *addr, u_int len)
{

        if (xdrs->x_handy < len)
                return (FALSE);
        xdrs->x_handy -= len;
        memmove(addr, xdrs->x_private, len);
        xdrs->x_private = (char *)xdrs->x_private + len;
        return (TRUE);
}

static bool_t
xdrmem_putbytes(XDR *xdrs, const char *addr, u_int len)
{

        if (xdrs->x_handy < len)
                return (FALSE);
        xdrs->x_handy -= len;
        memmove(xdrs->x_private, addr, len);
        xdrs->x_private = (char *)xdrs->x_private + len;
        return (TRUE);
}

/*
 * Append mbuf.  May fail if not enough space.  Caller owns the mbuf.
 */
static bool_t
xdrmem_putmbuf(XDR *xdrs, struct mbuf *m)
{
        u_int len;

        if (__predict_false(m == NULL))
                return (TRUE);

        len = m_length(m, NULL);

        if (__predict_false(xdrs->x_handy < len))
                return (FALSE);
        xdrs->x_handy -= len;
        m_copydata(m, 0, len, xdrs->x_private);
        xdrs->x_private = (char *)xdrs->x_private + len;
        return (TRUE);
}

static u_int
xdrmem_getpos(XDR *xdrs)
{

        /* XXX w/64-bit pointers, u_int not enough! */
        return (u_int)((u_long)xdrs->x_private - (u_long)xdrs->x_base);
}

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

        if (newaddr > lastaddr)
                return (FALSE);
        xdrs->x_private = newaddr;
        xdrs->x_handy = (u_int)(lastaddr - newaddr); /* XXX sizeof(u_int) <? sizeof(ptrdiff_t) */
        return (TRUE);
}

static int32_t *
xdrmem_inline_aligned(XDR *xdrs, u_int len)
{
        int32_t *buf = NULL;

        if (xdrs->x_handy >= len) {
                xdrs->x_handy -= len;
                buf = (int32_t *)xdrs->x_private;
                xdrs->x_private = (char *)xdrs->x_private + len;
        }
        return (buf);
}

/* ARGSUSED */
static int32_t *
xdrmem_inline_unaligned(XDR *xdrs, u_int len)
{

        return (0);
}

static bool_t
xdrmem_control(XDR *xdrs, int request, void *info)
{
        xdr_bytesrec *xptr;
        int32_t *l;
        int len;

        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);

        case XDR_PEEK:
                /*
                 * Return the next 4 byte unit in the XDR stream.
                 */
                if (xdrs->x_handy < sizeof (int32_t))
                        return (FALSE);
                l = (int32_t *)info;
                *l = (int32_t)ntohl((uint32_t)
                    (*((int32_t *)(xdrs->x_private))));
                return (TRUE);

        case XDR_SKIPBYTES:
                /*
                 * Skip the next N bytes in the XDR stream.
                 */
                l = (int32_t *)info;
                len = RNDUP((int)(*l));
                if (xdrs->x_handy < len)
                        return (FALSE);
                xdrs->x_handy -= len;
                xdrs->x_private = (char *)xdrs->x_private + len;
                return (TRUE);
        }
        return (FALSE);
}