xref: /openbsd/include/rpc/xdr.h (revision 2811b70e)
1 /*	$OpenBSD: xdr.h,v 1.14 2022/12/27 07:44:56 jmc Exp $	*/
2 /*	$NetBSD: xdr.h,v 1.7 1995/04/29 05:28:06 cgd Exp $	*/
3 
4 /*
5  * Copyright (c) 2010, Oracle America, Inc.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions are
9  * met:
10  *
11  *     * Redistributions of source code must retain the above copyright
12  *       notice, this list of conditions and the following disclaimer.
13  *     * Redistributions in binary form must reproduce the above
14  *       copyright notice, this list of conditions and the following
15  *       disclaimer in the documentation and/or other materials
16  *       provided with the distribution.
17  *     * Neither the name of the "Oracle America, Inc." nor the names of its
18  *       contributors may be used to endorse or promote products derived
19  *       from this software without specific prior written permission.
20  *
21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25  *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
26  *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
28  *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29  *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
30  *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
31  *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
32  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  *
34  *	from: @(#)xdr.h 1.19 87/04/22 SMI
35  *	@(#)xdr.h	2.2 88/07/29 4.0 RPCSRC
36  */
37 
38 /*
39  * xdr.h, External Data Representation Serialization Routines.
40  */
41 
42 #ifndef _RPC_XDR_H
43 #define _RPC_XDR_H
44 #include <sys/cdefs.h>
45 
46 /*
47  * XDR provides a conventional way for converting between C data
48  * types and an external bit-string representation.  Library supplied
49  * routines provide for the conversion on built-in C data types.  These
50  * routines and utility routines defined here are used to help implement
51  * a type encode/decode routine for each user-defined type.
52  *
53  * Each data type provides a single procedure which takes two arguments:
54  *
55  *	bool_t
56  *	xdrproc(xdrs, argresp)
57  *		XDR *xdrs;
58  *		<type> *argresp;
59  *
60  * xdrs is an instance of a XDR handle, to which or from which the data
61  * type is to be converted.  argresp is a pointer to the structure to be
62  * converted.  The XDR handle contains an operation field which indicates
63  * which of the operations (ENCODE, DECODE * or FREE) is to be performed.
64  *
65  * XDR_DECODE may allocate space if the pointer argresp is null.  This
66  * data can be freed with the XDR_FREE operation.
67  *
68  * We write only one procedure per data type to make it easy
69  * to keep the encode and decode procedures for a data type consistent.
70  * In many cases the same code performs all operations on a user defined type,
71  * because all the hard work is done in the component type routines.
72  * decode as a series of calls on the nested data types.
73  */
74 
75 /*
76  * Xdr operations.  XDR_ENCODE causes the type to be encoded into the
77  * stream.  XDR_DECODE causes the type to be extracted from the stream.
78  * XDR_FREE can be used to release the space allocated by an XDR_DECODE
79  * request.
80  */
81 enum xdr_op {
82 	XDR_ENCODE=0,
83 	XDR_DECODE=1,
84 	XDR_FREE=2
85 };
86 
87 /*
88  * This is the number of bytes per unit of external data.
89  */
90 #define BYTES_PER_XDR_UNIT	(4)
91 #define RNDUP(x)  ((((x) + BYTES_PER_XDR_UNIT - 1) / BYTES_PER_XDR_UNIT) \
92 		    * BYTES_PER_XDR_UNIT)
93 
94 /*
95  * The XDR handle.
96  * Contains operation which is being applied to the stream,
97  * an operations vector for the particular implementation (e.g. see xdr_mem.c),
98  * and two private fields for the use of the particular implementation.
99  */
100 typedef struct __rpc_xdr {
101 	enum xdr_op	x_op;		/* operation; fast additional param */
102 	const struct xdr_ops {
103 		/* get a long from underlying stream */
104 		bool_t	(*x_getlong)(struct __rpc_xdr *, long *);
105 		/* put a long to " */
106 		bool_t	(*x_putlong)(struct __rpc_xdr *, long *);
107 		/* get some bytes from " */
108 		bool_t	(*x_getbytes)(struct __rpc_xdr *, caddr_t,
109 		    unsigned int);
110 		/* put some bytes to " */
111 		bool_t	(*x_putbytes)(struct __rpc_xdr *, caddr_t,
112 		    unsigned int);
113 		/* returns bytes off from beginning */
114 		unsigned int	(*x_getpostn)(struct __rpc_xdr *);
115 		/* lets you reposition the stream */
116 		bool_t  (*x_setpostn)(struct __rpc_xdr *, unsigned int);
117 		/* buf quick ptr to buffered data */
118 		int32_t	*(*x_inline)(struct __rpc_xdr *, unsigned int);
119 		/* free privates of this xdr_stream */
120 		void	(*x_destroy)(struct __rpc_xdr *);
121 		bool_t	(*x_control)(struct __rpc_xdr *, int, void *);
122 	} *x_ops;
123 	caddr_t 	x_public;	/* users' data */
124 	caddr_t		x_private;	/* pointer to private data */
125 	caddr_t 	x_base;		/* private used for position info */
126 	unsigned int	x_handy;	/* extra private word */
127 } XDR;
128 
129 /*
130  * A xdrproc_t exists for each data type which is to be encoded or decoded.
131  *
132  * The second argument to the xdrproc_t is a pointer to an opaque pointer.
133  * The opaque pointer generally points to a structure of the data type
134  * to be decoded.  If this pointer is 0, then the type routines should
135  * allocate dynamic storage of the appropriate size and return it.
136  *
137  * XXX can't actually prototype it, because some take three args!!!
138  */
139 typedef	bool_t (*xdrproc_t)(/* XDR *, void *, unsigned int */);
140 
141 /*
142  * Operations defined on a XDR handle
143  *
144  * XDR		*xdrs;
145  * long		*longp;
146  * caddr_t	 addr;
147  * unsigned int	 len;
148  * unsigned int	 pos;
149  */
150 #define XDR_GETLONG(xdrs, longp)			\
151 	(*(xdrs)->x_ops->x_getlong)(xdrs, longp)
152 #define xdr_getlong(xdrs, longp)			\
153 	(*(xdrs)->x_ops->x_getlong)(xdrs, longp)
154 
155 #define XDR_PUTLONG(xdrs, longp)			\
156 	(*(xdrs)->x_ops->x_putlong)(xdrs, longp)
157 #define xdr_putlong(xdrs, longp)			\
158 	(*(xdrs)->x_ops->x_putlong)(xdrs, longp)
159 
160 #define XDR_GETBYTES(xdrs, addr, len)			\
161 	(*(xdrs)->x_ops->x_getbytes)(xdrs, addr, len)
162 #define xdr_getbytes(xdrs, addr, len)			\
163 	(*(xdrs)->x_ops->x_getbytes)(xdrs, addr, len)
164 
165 #define XDR_PUTBYTES(xdrs, addr, len)			\
166 	(*(xdrs)->x_ops->x_putbytes)(xdrs, addr, len)
167 #define xdr_putbytes(xdrs, addr, len)			\
168 	(*(xdrs)->x_ops->x_putbytes)(xdrs, addr, len)
169 
170 #define XDR_GETPOS(xdrs)				\
171 	(*(xdrs)->x_ops->x_getpostn)(xdrs)
172 #define xdr_getpos(xdrs)				\
173 	(*(xdrs)->x_ops->x_getpostn)(xdrs)
174 
175 #define XDR_SETPOS(xdrs, pos)				\
176 	(*(xdrs)->x_ops->x_setpostn)(xdrs, pos)
177 #define xdr_setpos(xdrs, pos)				\
178 	(*(xdrs)->x_ops->x_setpostn)(xdrs, pos)
179 
180 #define	XDR_INLINE(xdrs, len)				\
181 	(*(xdrs)->x_ops->x_inline)(xdrs, len)
182 #define	xdr_inline(xdrs, len)				\
183 	(*(xdrs)->x_ops->x_inline)(xdrs, len)
184 
185 #define	XDR_DESTROY(xdrs)				\
186 	if ((xdrs)->x_ops->x_destroy) 			\
187 		(*(xdrs)->x_ops->x_destroy)(xdrs)
188 #define	xdr_destroy(xdrs)				\
189 	if ((xdrs)->x_ops->x_destroy) 			\
190 		(*(xdrs)->x_ops->x_destroy)(xdrs)
191 
192 /*
193  * Support struct for discriminated unions.
194  * You create an array of xdrdiscrim structures, terminated with
195  * a entry with a null procedure pointer.  The xdr_union routine gets
196  * the discriminant value and then searches the array of structures
197  * for a matching value.  If a match is found the associated xdr routine
198  * is called to handle that part of the union.  If there is
199  * no match, then a default routine may be called.
200  * If there is no match and no default routine it is an error.
201  */
202 #define NULL_xdrproc_t ((xdrproc_t)0)
203 struct xdr_discrim {
204 	int	value;
205 	xdrproc_t proc;
206 };
207 
208 /*
209  * In-line routines for fast encode/decode of primitive data types.
210  * Caveat emptor: these use single memory cycles to get the
211  * data from the underlying buffer, and will fail to operate
212  * properly if the data is not aligned.  The standard way to use these
213  * is to say:
214  *	if ((buf = XDR_INLINE(xdrs, count)) == NULL)
215  *		return (FALSE);
216  *	<<< macro calls >>>
217  * where ``count'' is the number of bytes of data occupied
218  * by the primitive data types.
219  *
220  * N.B. and frozen for all time: each data type here uses 4 bytes
221  * of external representation.
222  */
223 #define IXDR_GET_LONG(buf)		((long)ntohl((unsigned long)*(buf)++))
224 #define IXDR_PUT_LONG(buf, v)		(*(buf)++ = (long)htonl((unsigned long)v))
225 
226 #define IXDR_GET_BOOL(buf)		((bool_t)IXDR_GET_LONG(buf))
227 #define IXDR_GET_ENUM(buf, t)		((t)IXDR_GET_LONG(buf))
228 #define IXDR_GET_U_LONG(buf)		((unsigned long)IXDR_GET_LONG(buf))
229 #define IXDR_GET_SHORT(buf)		((short)IXDR_GET_LONG(buf))
230 #define IXDR_GET_U_SHORT(buf)		((unsigned short)IXDR_GET_LONG(buf))
231 
232 #define IXDR_PUT_BOOL(buf, v)		IXDR_PUT_LONG((buf), ((long)(v)))
233 #define IXDR_PUT_ENUM(buf, v)		IXDR_PUT_LONG((buf), ((long)(v)))
234 #define IXDR_PUT_U_LONG(buf, v)		IXDR_PUT_LONG((buf), ((long)(v)))
235 #define IXDR_PUT_SHORT(buf, v)		IXDR_PUT_LONG((buf), ((long)(v)))
236 #define IXDR_PUT_U_SHORT(buf, v)	IXDR_PUT_LONG((buf), ((long)(v)))
237 
238 /*
239  * These are the "generic" xdr routines.
240  */
241 __BEGIN_DECLS
242 extern bool_t	xdr_void(void);
243 extern bool_t	xdr_int(XDR *, int *);
244 extern bool_t	xdr_u_int(XDR *, unsigned int *);
245 extern bool_t	xdr_long(XDR *, long *);
246 extern bool_t	xdr_u_long(XDR *, unsigned long *);
247 extern bool_t	xdr_short(XDR *, short *);
248 extern bool_t	xdr_u_short(XDR *, unsigned short *);
249 extern bool_t	xdr_int16_t(XDR *, int16_t *);
250 extern bool_t	xdr_u_int16_t(XDR *, u_int16_t *);
251 extern bool_t	xdr_int32_t(XDR *, int32_t *);
252 extern bool_t	xdr_u_int32_t(XDR *, u_int32_t *);
253 extern bool_t	xdr_int64_t(XDR *, int64_t *);
254 extern bool_t	xdr_u_int64_t(XDR *, u_int64_t *);
255 extern bool_t	xdr_bool(XDR *, bool_t *);
256 extern bool_t	xdr_enum(XDR *, enum_t *);
257 extern bool_t	xdr_array(XDR *, char **, unsigned int *, unsigned int,
258     unsigned int, xdrproc_t);
259 extern bool_t	xdr_bytes(XDR *, char **, unsigned int *, unsigned int);
260 extern bool_t	xdr_opaque(XDR *, caddr_t, unsigned int);
261 extern bool_t	xdr_string(XDR *, char **, unsigned int);
262 extern bool_t	xdr_union(XDR *, enum_t *, char *, struct xdr_discrim *,
263     xdrproc_t);
264 extern bool_t	xdr_char(XDR *, char *);
265 extern bool_t	xdr_u_char(XDR *, unsigned char *);
266 extern bool_t	xdr_vector(XDR *, char *, unsigned int, unsigned int,
267     xdrproc_t);
268 extern bool_t	xdr_float(XDR *, float *);
269 extern bool_t	xdr_double(XDR *, double *);
270 extern bool_t	xdr_reference(XDR *, caddr_t *, unsigned int, xdrproc_t);
271 extern bool_t	xdr_pointer(XDR *, caddr_t *, unsigned int, xdrproc_t);
272 extern bool_t	xdr_wrapstring(XDR *, char **);
273 extern void	xdr_free(xdrproc_t, char *);
274 __END_DECLS
275 
276 /*
277  * Common opaque bytes objects used by many rpc protocols;
278  * declared here due to commonality.
279  */
280 #define MAX_NETOBJ_SZ 1024
281 struct netobj {
282 	unsigned int	 n_len;
283 	char		*n_bytes;
284 };
285 typedef struct netobj netobj;
286 extern bool_t   xdr_netobj(XDR *, struct netobj *);
287 
288 /*
289  * These are the public routines for the various implementations of
290  * xdr streams.
291  */
292 __BEGIN_DECLS
293 /* XDR using memory buffers */
294 extern void   xdrmem_create(XDR *, char *, unsigned int, enum xdr_op);
295 
296 #ifdef _STDIO_H_
297 /* XDR using stdio library */
298 extern void   xdrstdio_create(XDR *, FILE *, enum xdr_op);
299 #endif
300 
301 /* XDR pseudo records for tcp */
302 extern void   xdrrec_create(XDR *, unsigned int, unsigned int, char *,
303 			    int (*)(caddr_t, caddr_t, int),
304 			    int (*)(caddr_t, caddr_t, int));
305 
306 /* make end of xdr record */
307 extern bool_t xdrrec_endofrecord(XDR *, int);
308 
309 /* move to beginning of next record */
310 extern bool_t xdrrec_skiprecord(XDR *);
311 
312 /* true if no more input */
313 extern bool_t xdrrec_eof(XDR *);
314 __END_DECLS
315 
316 #endif /* !_RPC_XDR_H */
317