/* $Id: xdr_reference.c,v 1.1 1999/01/11 23:04:58 kaminsky 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
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 * 
 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
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 * Sun RPC is provided with no support and without any obligation on the
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 * 
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 * OR ANY PART THEREOF.
 * 
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 * or profits or other special, indirect and consequential damages, even if
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 * Sun Microsystems, Inc.
 * 2550 Garcia Avenue
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 */

/*
 * xdr_reference.c, Generic XDR routines impelmentation.
 *
 * Copyright (C) 1987, Sun Microsystems, Inc.
 *
 * These are the "non-trivial" xdr primitives used to serialize and de-serialize
 * "pointers".  See xdr.h for more info on the interface to xdr.
 */

#include "arpc.h"

/*
 * XDR an indirect pointer
 * xdr_reference is for recursively translating a structure that is
 * referenced by a pointer inside the structure that is currently being
 * translated.  pp references a pointer to storage. If *pp is null
 * the  necessary storage is allocated.
 * size is the sizeof the referneced structure.
 * proc is the routine to handle the referenced structure.
 */
bool_t
xdr_reference (register XDR * xdrs, caddr_t * pp, u_int size, xdrproc_t proc)
				/* the pointer to work on */
				/* size of the object pointed to */
				/* xdr routine to handle the object */
{
  register caddr_t loc = *pp;
  register bool_t stat;

  if (loc == NULL)
    switch (xdrs->x_op) {
    case XDR_FREE:
      return (TRUE);

    case XDR_DECODE:
      *pp = loc = (caddr_t) mem_alloc (size);
      if (loc == NULL) {
	warn ("xdr_reference: out of memory\n");
	return (FALSE);
      }
      memset (loc, 0, (int) size);
      break;

    case XDR_ENCODE:
      break;
    }

  stat = (*proc) (xdrs, loc);

  if (xdrs->x_op == XDR_FREE) {
    mem_free (loc, size);
    *pp = NULL;
  }
  return (stat);
}


/*
 * xdr_pointer():
 *
 * XDR a pointer to a possibly recursive data structure. This
 * differs with xdr_reference in that it can serialize/deserialiaze
 * trees correctly.
 *
 *  What's sent is actually a union:
 *
 *  union object_pointer switch (boolean b) {
 *  case TRUE: object_data data;
 *  case FALSE: void nothing;
 *  }
 *
 * > objpp: Pointer to the pointer to the object.
 * > obj_size: size of the object.
 * > xdr_obj: routine to XDR an object.
 *
 */
bool_t
xdr_pointer (register XDR * xdrs, char **objpp, u_int obj_size, xdrproc_t xdr_obj)
{

  bool_t more_data;

  more_data = (*objpp != NULL);
  if (!xdr_bool (xdrs, &more_data)) {
    return (FALSE);
  }
  if (!more_data) {
    *objpp = NULL;
    return (TRUE);
  }
  return (xdr_reference (xdrs, objpp, obj_size, xdr_obj));
}
