/*

 * xdr_mem.c, XDR implementation using memory buffers.

 *

 * Copyright (c) 2010, Oracle America, Inc.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are

 * met:

 *

 *     * Redistributions of source code must retain the above copyright

 *       notice, this list of conditions and the following disclaimer.

 *     * Redistributions in binary form must reproduce the above

 *       copyright notice, this list of conditions and the following

 *       disclaimer in the documentation and/or other materials

 *       provided with the distribution.

 *     * Neither the name of the "Oracle America, Inc." nor the names of its

 *       contributors may be used to endorse or promote products derived

 *       from this software without specific prior written permission.

 *

 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS

 *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE

 *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,

 *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE

 *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

 *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,

 *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING

 *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 *

 * 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 <string.h>

#include <limits.h>

#include <rpc/rpc.h>

#include <shlib-compat.h>

static bool_t xdrmem_getlong (XDR *, long *);

static bool_t xdrmem_putlong (XDR *, const long *);

static bool_t xdrmem_getbytes (XDR *, caddr_t, u_int);

static bool_t xdrmem_putbytes (XDR *, const char *, u_int);

static u_int xdrmem_getpos (const XDR *);

static bool_t xdrmem_setpos (XDR *, u_int);

static int32_t *xdrmem_inline (XDR *, u_int);

static void xdrmem_destroy (XDR *);

static bool_t xdrmem_getint32 (XDR *, int32_t *);

static bool_t xdrmem_putint32 (XDR *, const int32_t *);

static const struct xdr_ops xdrmem_ops =

{

  xdrmem_getlong,

  xdrmem_putlong,

  xdrmem_getbytes,

  xdrmem_putbytes,

  xdrmem_getpos,

  xdrmem_setpos,

  xdrmem_inline,

  xdrmem_destroy,

  xdrmem_getint32,

  xdrmem_putint32

};

/*

 * The procedure xdrmem_create initializes a stream descriptor for a

 * memory buffer.

 */

void

xdrmem_create (XDR *xdrs, const caddr_t addr, u_int size, enum xdr_op op)

{

  xdrs->x_op = op;

  /* We have to add the const since the `struct xdr_ops' in `struct XDR'

     is not `const'.  */

  xdrs->x_ops = (struct xdr_ops *) &xdrmem_ops;

  xdrs->x_private = xdrs->x_base = addr;

  xdrs->x_handy = size;

}

#ifdef EXPORT_RPC_SYMBOLS

libc_hidden_def (xdrmem_create)

#else

libc_hidden_nolink_sunrpc (xdrmem_create, GLIBC_2_0)

#endif

/*

 * Nothing needs to be done for the memory case.  The argument is clearly

 * const.

 */

static void

xdrmem_destroy (XDR *xdrs)

{

}

/*

 * Gets the next word from the memory referenced by xdrs and places it

 * in the long pointed to by lp.  It then increments the private word to

 * point at the next element.  Neither object pointed to is const

 */

static bool_t

xdrmem_getlong (XDR *xdrs, long *lp)

{

  if (xdrs->x_handy < 4)

    return FALSE;

  xdrs->x_handy -= 4;

  *lp = (int32_t) ntohl ((*((int32_t *) (xdrs->x_private))));

  xdrs->x_private += 4;

  return TRUE;

}

/*

 * Puts the long pointed to by lp in the memory referenced by xdrs.  It

 * then increments the private word to point at the next element.  The

 * long pointed at is const

 */

static bool_t

xdrmem_putlong (XDR *xdrs, const long *lp)

{

  if (xdrs->x_handy < 4)

    return FALSE;

  xdrs->x_handy -= 4;

  *(int32_t *) xdrs->x_private = htonl (*lp);

  xdrs->x_private += 4;

  return TRUE;

}

/*

 * Gets an unaligned number of bytes from the xdrs structure and writes them

 * to the address passed in addr.  Be very careful when calling this routine

 * as it could leave the xdrs pointing to an unaligned structure which is not

 * a good idea.  None of the things pointed to are const.

 */

static bool_t

xdrmem_getbytes (XDR *xdrs, caddr_t addr, u_int len)

{

  if (xdrs->x_handy < len)

    return FALSE;

  xdrs->x_handy -= len;

  memcpy (addr, xdrs->x_private, len);

  xdrs->x_private += len;

  return TRUE;

}

/*

 * The complementary function to the above.  The same warnings apply about

 * unaligned data.  The source address is const.

 */

static bool_t

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

{

  if (xdrs->x_handy < len)

    return FALSE;

  xdrs->x_handy -= len;

  memcpy (xdrs->x_private, addr, len);

  xdrs->x_private += len;

  return TRUE;

}

/*

 * Not sure what this one does.  But it clearly doesn't modify the contents

 * of xdrs.  **FIXME** does this not assume u_int == u_long?

 */

static u_int

xdrmem_getpos (const XDR *xdrs)

{

  return (u_long) xdrs->x_private - (u_long) xdrs->x_base;

}

/*

 * xdrs modified

 */

static bool_t

xdrmem_setpos (XDR *xdrs, u_int pos)

{

  caddr_t newaddr = xdrs->x_base + pos;

  caddr_t lastaddr = xdrs->x_private + xdrs->x_handy;

  size_t handy = lastaddr - newaddr;

  if (newaddr > lastaddr

      || newaddr < xdrs->x_base

      || handy != (u_int) handy)

    return FALSE;

  xdrs->x_private = newaddr;

  xdrs->x_handy = (u_int) handy;

  return TRUE;

}

/*

 * xdrs modified

 */

static int32_t *

xdrmem_inline (XDR *xdrs, u_int len)

{

  int32_t *buf = 0;

  if (xdrs->x_handy >= len)

    {

      xdrs->x_handy -= len;

      buf = (int32_t *) xdrs->x_private;

      xdrs->x_private += len;

    }

  return buf;

}

/*

 * Gets the next word from the memory referenced by xdrs and places it

 * in the int pointed to by ip.  It then increments the private word to

 * point at the next element.  Neither object pointed to is const

 */

static bool_t

xdrmem_getint32 (XDR *xdrs, int32_t *ip)

{

  if (xdrs->x_handy < 4)

    return FALSE;

  xdrs->x_handy -= 4;

  *ip = ntohl ((*((int32_t *) (xdrs->x_private))));

  xdrs->x_private += 4;

  return TRUE;

}

/*

 * Puts the long pointed to by lp in the memory referenced by xdrs.  It

 * then increments the private word to point at the next element.  The

 * long pointed at is const

 */

static bool_t

xdrmem_putint32 (XDR *xdrs, const int32_t *ip)

{

  if (xdrs->x_handy < 4)

    return FALSE;

  xdrs->x_handy -= 4;

  *(int32_t *) xdrs->x_private = htonl (*ip);

  xdrs->x_private += 4;

  return TRUE;

}