xdr_reference.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef lint
static	char	*sccsid = "@(#)xdr_reference.c	4.1	7/2/90";
#endif lint

/************************************************************************
 *									*
 *			Copyright (c) 1986 by				*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/

/*
 *	Portions of this software have been licensed to 
 *	Digital Equipment Company, Maynard, MA.
 *	Copyright (c) 1986 Sun Microsystems, Inc.  ALL RIGHTS RESERVED.
 */

/*
 * 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.
 *
 *	History:
 *
 * 12-11-87	Robin L. and Larry C. and Ricky P.
 *	Added new kmalloc memory allocation to system.
 *
 */

#ifdef KERNEL
#include "../h/types.h"
#include "../h/param.h"
#include "../rpc/types.h"
#include "../rpc/xdr.h"
#else
/*include "types.h"*/
/*include "xdr.h"*/
/*#include <stdio.h>*/
#endif

#define LASTUNSIGNED	((u_int)0-1)

/* The func mem_alloc is #defined to be one of these in types.h (ugh!). */
#ifdef KERNEL
char *km_alloc();
#else
char *malloc();
#endif

/*
 * 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:
			mem_alloc(loc, char *, size, KM_RPC);
			*pp = loc;
#ifndef KERNEL
			if (loc == NULL) {
				fprintf(stderr,
				    "xdr_reference: out of memory\n");
				return (FALSE);
			}
#endif
			bzero(loc, (int)size);
			break;
	}

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

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