xdr_sizeof.c revision 273188 
1/*-
2 * Copyright (c) 2010, Oracle America, Inc.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met:
7 *
8 *     * Redistributions of source code must retain the above copyright
9 *       notice, this list of conditions and the following disclaimer.
10 *     * Redistributions in binary form must reproduce the above
11 *       copyright notice, this list of conditions and the following
12 *       disclaimer in the documentation and/or other materials
13 *       provided with the distribution.
14 *     * Neither the name of the "Oracle America, Inc." nor the names of its
15 *       contributors may be used to endorse or promote products derived
16 *       from this software without specific prior written permission.
17 *
18 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
21 *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
22 *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
23 *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
25 *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
27 *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
28 *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31/*
32 * xdr_sizeof.c
33 *
34 * General purpose routine to see how much space something will use
35 * when serialized using XDR.
36 */
37
38#include <sys/cdefs.h>
39__FBSDID("$FreeBSD: releng/10.1/lib/libc/xdr/xdr_sizeof.c 273188 2014-10-16 22:00:24Z hrs $");
40
41#include "namespace.h"
42#include <rpc/types.h>
43#include <rpc/xdr.h>
44#include <sys/types.h>
45#include <stdlib.h>
46#include "un-namespace.h"
47
48/* ARGSUSED */
49static bool_t
50x_putlong(xdrs, longp)
51	XDR *xdrs;
52	long *longp;
53{
54	xdrs->x_handy += BYTES_PER_XDR_UNIT;
55	return (TRUE);
56}
57
58/* ARGSUSED */
59static bool_t
60x_putbytes(xdrs, bp, len)
61	XDR *xdrs;
62	char  *bp;
63	u_int len;
64{
65	xdrs->x_handy += len;
66	return (TRUE);
67}
68
69static u_int
70x_getpostn(xdrs)
71	XDR *xdrs;
72{
73	return (xdrs->x_handy);
74}
75
76/* ARGSUSED */
77static bool_t
78x_setpostn(xdrs, pos)
79	XDR *xdrs;
80	u_int pos;
81{
82	/* This is not allowed */
83	return (FALSE);
84}
85
86static int32_t *
87x_inline(xdrs, len)
88	XDR *xdrs;
89	u_int len;
90{
91	if (len == 0) {
92		return (NULL);
93	}
94	if (xdrs->x_op != XDR_ENCODE) {
95		return (NULL);
96	}
97	if (len < (u_int)(uintptr_t)xdrs->x_base) {
98		/* x_private was already allocated */
99		xdrs->x_handy += len;
100		return ((int32_t *) xdrs->x_private);
101	} else {
102		/* Free the earlier space and allocate new area */
103		if (xdrs->x_private)
104			free(xdrs->x_private);
105		if ((xdrs->x_private = (caddr_t) malloc(len)) == NULL) {
106			xdrs->x_base = 0;
107			return (NULL);
108		}
109		xdrs->x_base = (caddr_t)(uintptr_t)len;
110		xdrs->x_handy += len;
111		return ((int32_t *) xdrs->x_private);
112	}
113}
114
115static int
116harmless()
117{
118	/* Always return FALSE/NULL, as the case may be */
119	return (0);
120}
121
122static void
123x_destroy(xdrs)
124	XDR *xdrs;
125{
126	xdrs->x_handy = 0;
127	xdrs->x_base = 0;
128	if (xdrs->x_private) {
129		free(xdrs->x_private);
130		xdrs->x_private = NULL;
131	}
132	return;
133}
134
135unsigned long
136xdr_sizeof(func, data)
137	xdrproc_t func;
138	void *data;
139{
140	XDR x;
141	struct xdr_ops ops;
142	bool_t stat;
143	/* to stop ANSI-C compiler from complaining */
144	typedef  bool_t (* dummyfunc1)(XDR *, long *);
145	typedef  bool_t (* dummyfunc2)(XDR *, caddr_t, u_int);
146
147	ops.x_putlong = x_putlong;
148	ops.x_putbytes = x_putbytes;
149	ops.x_inline = x_inline;
150	ops.x_getpostn = x_getpostn;
151	ops.x_setpostn = x_setpostn;
152	ops.x_destroy = x_destroy;
153
154	/* the other harmless ones */
155	ops.x_getlong =  (dummyfunc1) harmless;
156	ops.x_getbytes = (dummyfunc2) harmless;
157
158	x.x_op = XDR_ENCODE;
159	x.x_ops = &ops;
160	x.x_handy = 0;
161	x.x_private = (caddr_t) NULL;
162	x.x_base = (caddr_t) 0;
163
164	stat = func(&x, data);
165	if (x.x_private)
166		free(x.x_private);
167	return (stat == TRUE ? (unsigned) x.x_handy: 0);
168}
169