xdr_sizeof.c revision 74462 
1/*
2 * $FreeBSD: head/lib/libc/xdr/xdr_sizeof.c 74462 2001-03-19 12:50:13Z alfred $
3 *
4 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
5 * unrestricted use provided that this legend is included on all tape
6 * media and as a part of the software program in whole or part.  Users
7 * may copy or modify Sun RPC without charge, but are not authorized
8 * to license or distribute it to anyone else except as part of a product or
9 * program developed by the user.
10 *
11 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
12 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
13 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
14 *
15 * Sun RPC is provided with no support and without any obligation on the
16 * part of Sun Microsystems, Inc. to assist in its use, correction,
17 * modification or enhancement.
18 *
19 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
20 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
21 * OR ANY PART THEREOF.
22 *
23 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
24 * or profits or other special, indirect and consequential damages, even if
25 * Sun has been advised of the possibility of such damages.
26 *
27 * Sun Microsystems, Inc.
28 * 2550 Garcia Avenue
29 * Mountain View, California  94043
30 */
31/*
32 * xdr_sizeof.c
33 *
34 * Copyright 1990 Sun Microsystems, Inc.
35 *
36 * General purpose routine to see how much space something will use
37 * when serialized using XDR.
38 */
39
40#include "namespace.h"
41#include <rpc/types.h>
42#include <rpc/xdr.h>
43#include <sys/types.h>
44#include <stdlib.h>
45#include "un-namespace.h"
46
47/* ARGSUSED */
48static bool_t
49x_putlong(xdrs, longp)
50	XDR *xdrs;
51	long *longp;
52{
53	xdrs->x_handy += BYTES_PER_XDR_UNIT;
54	return (TRUE);
55}
56
57/* ARGSUSED */
58static bool_t
59x_putbytes(xdrs, bp, len)
60	XDR *xdrs;
61	char  *bp;
62	int len;
63{
64	xdrs->x_handy += len;
65	return (TRUE);
66}
67
68static u_int
69x_getpostn(xdrs)
70	XDR *xdrs;
71{
72	return (xdrs->x_handy);
73}
74
75/* ARGSUSED */
76static bool_t
77x_setpostn(xdrs, pos)
78	XDR *xdrs;
79	u_int pos;
80{
81	/* This is not allowed */
82	return (FALSE);
83}
84
85static int32_t *
86x_inline(xdrs, len)
87	XDR *xdrs;
88	long len;
89{
90	if (len == 0) {
91		return (NULL);
92	}
93	if (xdrs->x_op != XDR_ENCODE) {
94		return (NULL);
95	}
96	if (len < (long) xdrs->x_base) {
97		/* x_private was already allocated */
98		xdrs->x_handy += len;
99		return ((int32_t *) xdrs->x_private);
100	} else {
101		/* Free the earlier space and allocate new area */
102		if (xdrs->x_private)
103			free(xdrs->x_private);
104		if ((xdrs->x_private = (caddr_t) malloc(len)) == NULL) {
105			xdrs->x_base = 0;
106			return (NULL);
107		}
108		xdrs->x_base = (caddr_t) len;
109		xdrs->x_handy += len;
110		return ((int32_t *) xdrs->x_private);
111	}
112}
113
114static int
115harmless()
116{
117	/* Always return FALSE/NULL, as the case may be */
118	return (0);
119}
120
121static void
122x_destroy(xdrs)
123	XDR *xdrs;
124{
125	xdrs->x_handy = 0;
126	xdrs->x_base = 0;
127	if (xdrs->x_private) {
128		free(xdrs->x_private);
129		xdrs->x_private = NULL;
130	}
131	return;
132}
133
134unsigned long
135xdr_sizeof(func, data)
136	xdrproc_t func;
137	void *data;
138{
139	XDR x;
140	struct xdr_ops ops;
141	bool_t stat;
142	/* to stop ANSI-C compiler from complaining */
143	typedef  bool_t (* dummyfunc1)(XDR *, long *);
144	typedef  bool_t (* dummyfunc2)(XDR *, caddr_t, u_int);
145
146	ops.x_putlong = x_putlong;
147	ops.x_putbytes = x_putbytes;
148	ops.x_inline = x_inline;
149	ops.x_getpostn = x_getpostn;
150	ops.x_setpostn = x_setpostn;
151	ops.x_destroy = x_destroy;
152
153	/* the other harmless ones */
154	ops.x_getlong =  (dummyfunc1) harmless;
155	ops.x_getbytes = (dummyfunc2) harmless;
156
157	x.x_op = XDR_ENCODE;
158	x.x_ops = &ops;
159	x.x_handy = 0;
160	x.x_private = (caddr_t) NULL;
161	x.x_base = (caddr_t) 0;
162
163	stat = func(&x, data);
164	if (x.x_private)
165		free(x.x_private);
166	return (stat == TRUE ? (unsigned) x.x_handy: 0);
167}
168