xref: /illumos-gate/usr/src/lib/libnsl/rpc/xdr_refer.c (revision 22cc57556161a28b2141976ff578db2558def3e1)

/*
 * 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 2006 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.
 */

/*
 * Generic XDR routines impelmentation.
 *
 * 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 "mt.h"
#include <sys/types.h>
#include <syslog.h>
#include <stdio.h>
#include <stdlib.h>
#include <rpc/types.h>
#include <rpc/xdr.h>
#include <memory.h>

#define	LASTUNSIGNED	((uint_t)0-1)
char mem_err_msg_ref[] = "xdr_reference: out of memory";

/*
 * 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(XDR *xdrs, caddr_t *pp, uint_t size, const xdrproc_t proc)
{
	caddr_t loc = *pp;
	bool_t stat;

	/* Make sure x_op contains a valid value */
	if (xdrs->x_op != XDR_ENCODE &&
	    xdrs->x_op != XDR_DECODE &&
	    xdrs->x_op != XDR_FREE)
		return (FALSE);

	if (loc == NULL)
		switch (xdrs->x_op) {
		case XDR_FREE:
			return (TRUE);
		case XDR_DECODE:
			*pp = loc = malloc(size);
			if (loc == NULL) {
				(void) syslog(LOG_ERR, mem_err_msg_ref);
				return (FALSE);
			}
			(void) memset(loc, 0, (int)size);
			break;
	}

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

	if (xdrs->x_op == XDR_FREE) {
		free(loc);
		*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(XDR *xdrs, char **objpp, uint_t obj_size, const 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));
}