xref: /freebsd/sys/xdr/xdr_sizeof.c (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
1 /*
2  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
3  * unrestricted use provided that this legend is included on all tape
4  * media and as a part of the software program in whole or part.  Users
5  * may copy or modify Sun RPC without charge, but are not authorized
6  * to license or distribute it to anyone else except as part of a product or
7  * program developed by the user.
8  *
9  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
10  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
11  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
12  *
13  * Sun RPC is provided with no support and without any obligation on the
14  * part of Sun Microsystems, Inc. to assist in its use, correction,
15  * modification or enhancement.
16  *
17  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
18  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
19  * OR ANY PART THEREOF.
20  *
21  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
22  * or profits or other special, indirect and consequential damages, even if
23  * Sun has been advised of the possibility of such damages.
24  *
25  * Sun Microsystems, Inc.
26  * 2550 Garcia Avenue
27  * Mountain View, California  94043
28  */
29 /*
30  * xdr_sizeof.c
31  *
32  * Copyright 1990 Sun Microsystems, Inc.
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 <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/malloc.h>
44 
45 #include <rpc/types.h>
46 #include <rpc/xdr.h>
47 
48 /* ARGSUSED */
49 static bool_t
50 x_putlong(XDR *xdrs, const long *longp)
51 {
52 
53 	xdrs->x_handy += BYTES_PER_XDR_UNIT;
54 	return (TRUE);
55 }
56 
57 /* ARGSUSED */
58 static bool_t
59 x_putbytes(XDR *xdrs, const char *bp, u_int len)
60 {
61 
62 	xdrs->x_handy += len;
63 	return (TRUE);
64 }
65 
66 static u_int
67 x_getpostn(XDR *xdrs)
68 {
69 
70 	return (xdrs->x_handy);
71 }
72 
73 /* ARGSUSED */
74 static bool_t
75 x_setpostn(XDR *xdrs, u_int pos)
76 {
77 
78 	/* This is not allowed */
79 	return (FALSE);
80 }
81 
82 static int32_t *
83 x_inline(XDR *xdrs, u_int len)
84 {
85 
86 	if (len == 0) {
87 		return (NULL);
88 	}
89 	if (xdrs->x_op != XDR_ENCODE) {
90 		return (NULL);
91 	}
92 	if (len < (u_int)(uintptr_t)xdrs->x_base) {
93 		/* x_private was already allocated */
94 		xdrs->x_handy += len;
95 		return ((int32_t *) xdrs->x_private);
96 	} else {
97 		/* Free the earlier space and allocate new area */
98 		if (xdrs->x_private)
99 			free(xdrs->x_private, M_RPC);
100 		if ((xdrs->x_private = (caddr_t) malloc(len, M_RPC, M_WAITOK)) == NULL) {
101 			xdrs->x_base = 0;
102 			return (NULL);
103 		}
104 		xdrs->x_base = (caddr_t)(uintptr_t) len;
105 		xdrs->x_handy += len;
106 		return ((int32_t *) xdrs->x_private);
107 	}
108 }
109 
110 static int
111 harmless(void)
112 {
113 
114 	/* Always return FALSE/NULL, as the case may be */
115 	return (0);
116 }
117 
118 static void
119 x_destroy(XDR *xdrs)
120 {
121 
122 	xdrs->x_handy = 0;
123 	xdrs->x_base = 0;
124 	if (xdrs->x_private) {
125 		free(xdrs->x_private, M_RPC);
126 		xdrs->x_private = NULL;
127 	}
128 	return;
129 }
130 
131 unsigned long
132 xdr_sizeof(xdrproc_t func, void *data)
133 {
134 	XDR x;
135 	struct xdr_ops ops;
136 	bool_t stat;
137 	/* to stop ANSI-C compiler from complaining */
138 	typedef  bool_t (* dummyfunc1)(XDR *, long *);
139 	typedef  bool_t (* dummyfunc2)(XDR *, caddr_t, u_int);
140 
141 	ops.x_putlong = x_putlong;
142 	ops.x_putbytes = x_putbytes;
143 	ops.x_inline = x_inline;
144 	ops.x_getpostn = x_getpostn;
145 	ops.x_setpostn = x_setpostn;
146 	ops.x_destroy = x_destroy;
147 
148 	/* the other harmless ones */
149 	ops.x_getlong =  (dummyfunc1) harmless;
150 	ops.x_getbytes = (dummyfunc2) harmless;
151 
152 	x.x_op = XDR_ENCODE;
153 	x.x_ops = &ops;
154 	x.x_handy = 0;
155 	x.x_private = (caddr_t) NULL;
156 	x.x_base = (caddr_t) 0;
157 
158 	stat = func(&x, data);
159 	if (x.x_private)
160 		free(x.x_private, M_RPC);
161 	return (stat == TRUE ? (unsigned) x.x_handy: 0);
162 }
163