xdr_reference.c revision 330897 
1/*	$NetBSD: xdr_reference.c,v 1.13 2000/01/22 22:19:18 mycroft Exp	$ */
2
3/*-
4 * SPDX-License-Identifier: BSD-3-Clause
5 *
6 * Copyright (c) 2010, Oracle America, Inc.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions are
10 * met:
11 *
12 *     * Redistributions of source code must retain the above copyright
13 *       notice, this list of conditions and the following disclaimer.
14 *     * Redistributions in binary form must reproduce the above
15 *       copyright notice, this list of conditions and the following
16 *       disclaimer in the documentation and/or other materials
17 *       provided with the distribution.
18 *     * Neither the name of the "Oracle America, Inc." nor the names of its
19 *       contributors may be used to endorse or promote products derived
20 *       from this software without specific prior written permission.
21 *
22 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25 *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
26 *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
27 *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
29 *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30 *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
31 *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32 *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
33 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35
36#if defined(LIBC_SCCS) && !defined(lint)
37static char *sccsid2 = "@(#)xdr_reference.c 1.11 87/08/11 SMI";
38static char *sccsid = "@(#)xdr_reference.c	2.1 88/07/29 4.0 RPCSRC";
39#endif
40#include <sys/cdefs.h>
41__FBSDID("$FreeBSD: stable/11/lib/libc/xdr/xdr_reference.c 330897 2018-03-14 03:19:51Z eadler $");
42
43/*
44 * xdr_reference.c, Generic XDR routines impelmentation.
45 *
46 * These are the "non-trivial" xdr primitives used to serialize and de-serialize
47 * "pointers".  See xdr.h for more info on the interface to xdr.
48 */
49
50#include "namespace.h"
51#include <err.h>
52#include <stdio.h>
53#include <stdlib.h>
54#include <string.h>
55
56#include <rpc/types.h>
57#include <rpc/xdr.h>
58#include "libc_private.h"
59
60/*
61 * XDR an indirect pointer
62 * xdr_reference is for recursively translating a structure that is
63 * referenced by a pointer inside the structure that is currently being
64 * translated.  pp references a pointer to storage. If *pp is null
65 * the  necessary storage is allocated.
66 * size is the sizeof the referneced structure.
67 * proc is the routine to handle the referenced structure.
68 */
69bool_t
70xdr_reference(XDR *xdrs, caddr_t *pp, u_int size, xdrproc_t proc)
71/*
72 *	XDR *xdrs;
73 *	caddr_t *pp;		// the pointer to work on
74 *	u_int size;		// size of the object pointed to
75 *	xdrproc_t proc;		// xdr routine to handle the object
76 */
77{
78	caddr_t loc = *pp;
79	bool_t stat;
80
81	if (loc == NULL)
82		switch (xdrs->x_op) {
83		case XDR_FREE:
84			return (TRUE);
85
86		case XDR_DECODE:
87			*pp = loc = (caddr_t) mem_alloc(size);
88			if (loc == NULL) {
89				warnx("xdr_reference: out of memory");
90				return (FALSE);
91			}
92			memset(loc, 0, size);
93			break;
94
95		case XDR_ENCODE:
96			break;
97		}
98
99	stat = (*proc)(xdrs, loc);
100
101	if (xdrs->x_op == XDR_FREE) {
102		mem_free(loc, size);
103		*pp = NULL;
104	}
105	return (stat);
106}
107
108
109/*
110 * xdr_pointer():
111 *
112 * XDR a pointer to a possibly recursive data structure. This
113 * differs with xdr_reference in that it can serialize/deserialiaze
114 * trees correctly.
115 *
116 *  What's sent is actually a union:
117 *
118 *  union object_pointer switch (boolean b) {
119 *  case TRUE: object_data data;
120 *  case FALSE: void nothing;
121 *  }
122 *
123 * > objpp: Pointer to the pointer to the object.
124 * > obj_size: size of the object.
125 * > xdr_obj: routine to XDR an object.
126 *
127 */
128bool_t
129xdr_pointer(XDR *xdrs, char **objpp, u_int obj_size, xdrproc_t xdr_obj)
130{
131
132	bool_t more_data;
133
134	more_data = (*objpp != NULL);
135	if (! xdr_bool(xdrs,&more_data)) {
136		return (FALSE);
137	}
138	if (! more_data) {
139		*objpp = NULL;
140		return (TRUE);
141	}
142	return (xdr_reference(xdrs,objpp,obj_size,xdr_obj));
143}
144