xref: /freebsd/crypto/krb5/src/lib/rpc/xdr_sizeof.c (revision b670c9bafc0e31c7609969bf374b2e80bdc00211)
1 /*
2  * Copyright (c) 2010, Oracle America, Inc.
3  *
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions are met:
8  *
9  *     * Redistributions of source code must retain the above copyright
10  *       notice, this list of conditions and the following disclaimer.
11  *
12  *     * Redistributions in binary form must reproduce the above copyright
13  *       notice, this list of conditions and the following disclaimer in
14  *       the documentation and/or other materials provided with the
15  *       distribution.
16  *
17  *     * Neither the name of the "Oracle America, Inc." nor the names of
18  *       its contributors may be used to endorse or promote products
19  *       derived from this software without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
22  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
23  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
24  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25  * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
27  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
28  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
29  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
31  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 /*
34  * xdr_sizeof.c
35  *
36  * General purpose routine to see how much space something will use
37  * when serialized using XDR.
38  */
39 
40 #include <gssrpc/types.h>
41 #include <gssrpc/xdr.h>
42 #include <sys/types.h>
43 
44 /* ARGSUSED */
45 static bool_t
46 x_putlong(xdrs, longp)
47 	XDR *xdrs;
48 	long *longp;
49 {
50 	xdrs->x_handy += BYTES_PER_XDR_UNIT;
51 	return (TRUE);
52 }
53 
54 /* ARGSUSED */
55 static bool_t
56 x_putbytes(xdrs, bp, len)
57 	XDR *xdrs;
58 	char  *bp;
59 	int len;
60 {
61 	xdrs->x_handy += len;
62 
63 	return (TRUE);
64 }
65 
66 static u_int
67 x_getpostn(xdrs)
68 	XDR *xdrs;
69 {
70 	return (xdrs->x_handy);
71 }
72 
73 /* ARGSUSED */
74 static bool_t
75 x_setpostn(xdrs, pos)
76 	XDR *xdrs;
77 	u_int pos;
78 {
79 	/* This is not allowed */
80 	return (FALSE);
81 }
82 
83 static rpc_inline_t *
84 x_inline(xdrs, len)
85 	XDR *xdrs;
86 	int len;
87 {
88 	if (len == 0) {
89 		return (NULL);
90 	}
91 	if (xdrs->x_op != XDR_ENCODE) {
92 		return (NULL);
93 	}
94 	if (len < (int) ((caddr_t) xdrs->x_private - xdrs->x_base)) {
95 		/* x_private was already allocated */
96 		xdrs->x_handy += len;
97 		return ((rpc_inline_t *) xdrs->x_private);
98 	} else {
99 		/* Free the earlier space and allocate new area */
100 		if (xdrs->x_base)
101 			free(xdrs->x_base);
102 		if ((xdrs->x_base = (caddr_t) malloc(len)) == NULL) {
103 			xdrs->x_private = NULL;
104 			return (NULL);
105 		}
106 		xdrs->x_private = xdrs->x_base + len;
107 		xdrs->x_handy += len;
108 		return ((rpc_inline_t *) (void *) xdrs->x_base);
109 	}
110 }
111 
112 static int
113 harmless()
114 {
115 	/* Always return FALSE/NULL, as the case may be */
116 	return (0);
117 }
118 
119 static void
120 x_destroy(xdrs)
121 	XDR *xdrs;
122 {
123 	xdrs->x_handy = 0;
124 	xdrs->x_private = NULL;
125 	if (xdrs->x_base) {
126 		free(xdrs->x_base);
127 		xdrs->x_base = NULL;
128 	}
129 	return;
130 }
131 
132 unsigned long
133 xdr_sizeof(func, data)
134 	xdrproc_t func;
135 	void *data;
136 {
137 	XDR x;
138 	struct xdr_ops ops;
139 	bool_t stat;
140 	/* to stop ANSI-C compiler from complaining */
141 	typedef  bool_t (* dummyfunc1)(XDR *, long *);
142 	typedef  bool_t (* dummyfunc2)(XDR *, caddr_t, u_int);
143 
144 	ops.x_putlong = x_putlong;
145 	ops.x_putbytes = x_putbytes;
146 	ops.x_inline = x_inline;
147 	ops.x_getpostn = x_getpostn;
148 	ops.x_setpostn = x_setpostn;
149 	ops.x_destroy = x_destroy;
150 
151 	/* the other harmless ones */
152 	ops.x_getlong =  (dummyfunc1) harmless;
153 	ops.x_getbytes = (dummyfunc2) harmless;
154 
155 	x.x_op = XDR_ENCODE;
156 	x.x_ops = &ops;
157 	x.x_handy = 0;
158 	x.x_private = (caddr_t) NULL;
159 	x.x_base = (caddr_t) 0;
160 
161 	stat = func(&x, data);
162 	if (x.x_base)
163 		free(x.x_base);
164 	return (stat == TRUE ? (unsigned) x.x_handy: 0);
165 }
166