xref: /freebsd/crypto/krb5/src/lib/rpc/xdr_reference.c (revision 7f2fe78b9dd5f51c821d771b63d2e096f6fd49e9)

/* @(#)xdr_reference.c	2.1 88/07/29 4.0 RPCSRC */
/*
 * Copyright (c) 2010, Oracle America, Inc.
 *
 * All rights reserved.
 *
 * 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 !defined(lint) && defined(SCCSIDS)
static char sccsid[] = "@(#)xdr_reference.c 1.11 87/08/11 SMI";
#endif

/*
 * xdr_reference.c, 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 <stdio.h>
#include <string.h>
#include <gssrpc/types.h>
#include <gssrpc/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 referenced structure.
 * proc is the routine to handle the referenced structure.
 */
bool_t
xdr_reference(
	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 */
	)
{
	caddr_t loc = *pp;
	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);
			}
			memset(loc, 0, size);
			break;

		case XDR_ENCODE:
			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(
	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));
}