lib/librpc/rpc/xdr_reference.c

/*
 * 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
 */

#if defined(LIBC_SCCS) && !defined(lint)
/*static char *sccsid = "from: @(#)xdr_reference.c 1.11 87/08/11 SMI";*/
/*static char *sccsid = "from: @(#)xdr_reference.c      2.1 88/07/29 4.0 RPCSRC";*/
static char *rcsid = "$Id: xdr_reference.c,v 1.3 1993/08/26 00:53:53 jtc Exp $";
#endif

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

#define LASTUNSIGNED    ((u_int)0-1)

/*
 * 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(xdrs, pp, size, proc)
        register XDR *xdrs;
        caddr_t *pp;            /* the pointer to work on */
        u_int size;             /* size of the object pointed to */
        xdrproc_t proc;         /* 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) {
                                (void) fprintf(stderr,
                                    "xdr_reference: out of memory\n");
                                return (FALSE);
                        }
                        bzero(loc, (int)size);
                        break;
        }

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

        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(xdrs,objpp,obj_size,xdr_obj)
        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));
}