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("$FreeBSD$");
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(XDR *xdrs, const long *longp)
51{
52	xdrs->x_handy += BYTES_PER_XDR_UNIT;
53	return (TRUE);
54}
55
56/* ARGSUSED */
57static bool_t
58x_putbytes(XDR *xdrs, const char *bp, u_int len)
59{
60	xdrs->x_handy += len;
61	return (TRUE);
62}
63
64static u_int
65x_getpostn(XDR *xdrs)
66{
67	return (xdrs->x_handy);
68}
69
70/* ARGSUSED */
71static bool_t
72x_setpostn(XDR *xdrs, u_int pos)
73{
74	/* This is not allowed */
75	return (FALSE);
76}
77
78static int32_t *
79x_inline(XDR *xdrs, u_int len)
80{
81	if (len == 0) {
82		return (NULL);
83	}
84	if (xdrs->x_op != XDR_ENCODE) {
85		return (NULL);
86	}
87	if (len < (u_int)(uintptr_t)xdrs->x_base) {
88		/* x_private was already allocated */
89		xdrs->x_handy += len;
90		return ((int32_t *) xdrs->x_private);
91	} else {
92		/* Free the earlier space and allocate new area */
93		if (xdrs->x_private)
94			free(xdrs->x_private);
95		if ((xdrs->x_private = (caddr_t) malloc(len)) == NULL) {
96			xdrs->x_base = 0;
97			return (NULL);
98		}
99		xdrs->x_base = (caddr_t)(uintptr_t)len;
100		xdrs->x_handy += len;
101		return ((int32_t *) xdrs->x_private);
102	}
103}
104
105static int
106harmless(void)
107{
108	/* Always return FALSE/NULL, as the case may be */
109	return (0);
110}
111
112static void
113x_destroy(XDR *xdrs)
114{
115	xdrs->x_handy = 0;
116	xdrs->x_base = 0;
117	if (xdrs->x_private) {
118		free(xdrs->x_private);
119		xdrs->x_private = NULL;
120	}
121	return;
122}
123
124unsigned long
125xdr_sizeof(xdrproc_t func, void *data)
126{
127	XDR x;
128	struct xdr_ops ops;
129	bool_t stat;
130	/* to stop ANSI-C compiler from complaining */
131	typedef  bool_t (* dummyfunc1)(XDR *, long *);
132	typedef  bool_t (* dummyfunc2)(XDR *, caddr_t, u_int);
133
134	ops.x_putlong = x_putlong;
135	ops.x_putbytes = x_putbytes;
136	ops.x_inline = x_inline;
137	ops.x_getpostn = x_getpostn;
138	ops.x_setpostn = x_setpostn;
139	ops.x_destroy = x_destroy;
140
141	/* the other harmless ones */
142	ops.x_getlong =  (dummyfunc1) harmless;
143	ops.x_getbytes = (dummyfunc2) harmless;
144
145	x.x_op = XDR_ENCODE;
146	x.x_ops = &ops;
147	x.x_handy = 0;
148	x.x_private = (caddr_t) NULL;
149	x.x_base = (caddr_t) 0;
150
151	stat = func(&x, data);
152	if (x.x_private)
153		free(x.x_private);
154	return (stat == TRUE ? (unsigned) x.x_handy: 0);
155}
156