xref: /freebsd/include/rpc/xdr.h (revision 5ebc7e6281887681c3a348a5a4c902e262ccd656)
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  *	from: @(#)xdr.h 1.19 87/04/22 SMI
30  *	from: @(#)xdr.h	2.2 88/07/29 4.0 RPCSRC
31  *	$Id: xdr.h,v 1.2 1994/08/07 18:41:02 wollman Exp $
32  */
33 
34 /*
35  * xdr.h, External Data Representation Serialization Routines.
36  *
37  * Copyright (C) 1984, Sun Microsystems, Inc.
38  */
39 
40 #ifndef _RPC_XDR_H
41 #define _RPC_XDR_H
42 #include <sys/cdefs.h>
43 
44 /*
45  * XDR provides a conventional way for converting between C data
46  * types and an external bit-string representation.  Library supplied
47  * routines provide for the conversion on built-in C data types.  These
48  * routines and utility routines defined here are used to help implement
49  * a type encode/decode routine for each user-defined type.
50  *
51  * Each data type provides a single procedure which takes two arguments:
52  *
53  *	bool_t
54  *	xdrproc(xdrs, argresp)
55  *		XDR *xdrs;
56  *		<type> *argresp;
57  *
58  * xdrs is an instance of a XDR handle, to which or from which the data
59  * type is to be converted.  argresp is a pointer to the structure to be
60  * converted.  The XDR handle contains an operation field which indicates
61  * which of the operations (ENCODE, DECODE * or FREE) is to be performed.
62  *
63  * XDR_DECODE may allocate space if the pointer argresp is null.  This
64  * data can be freed with the XDR_FREE operation.
65  *
66  * We write only one procedure per data type to make it easy
67  * to keep the encode and decode procedures for a data type consistent.
68  * In many cases the same code performs all operations on a user defined type,
69  * because all the hard work is done in the component type routines.
70  * decode as a series of calls on the nested data types.
71  */
72 
73 /*
74  * Xdr operations.  XDR_ENCODE causes the type to be encoded into the
75  * stream.  XDR_DECODE causes the type to be extracted from the stream.
76  * XDR_FREE can be used to release the space allocated by an XDR_DECODE
77  * request.
78  */
79 enum xdr_op {
80 	XDR_ENCODE=0,
81 	XDR_DECODE=1,
82 	XDR_FREE=2
83 };
84 
85 /*
86  * This is the number of bytes per unit of external data.
87  */
88 #define BYTES_PER_XDR_UNIT	(4)
89 #define RNDUP(x)  ((((x) + BYTES_PER_XDR_UNIT - 1) / BYTES_PER_XDR_UNIT) \
90 		    * BYTES_PER_XDR_UNIT)
91 
92 /*
93  * A xdrproc_t exists for each data type which is to be encoded or decoded.
94  *
95  * The second argument to the xdrproc_t is a pointer to an opaque pointer.
96  * The opaque pointer generally points to a structure of the data type
97  * to be decoded.  If this pointer is 0, then the type routines should
98  * allocate dynamic storage of the appropriate size and return it.
99  * bool_t	(*xdrproc_t)(XDR *, caddr_t *);
100  */
101 typedef	bool_t (*xdrproc_t)();
102 
103 /*
104  * The XDR handle.
105  * Contains operation which is being applied to the stream,
106  * an operations vector for the paticular implementation (e.g. see xdr_mem.c),
107  * and two private fields for the use of the particular impelementation.
108  */
109 typedef struct {
110 	enum xdr_op	x_op;		/* operation; fast additional param */
111 	struct xdr_ops {
112 		bool_t	(*x_getlong)();	/* get a long from underlying stream */
113 		bool_t	(*x_putlong)();	/* put a long to " */
114 		bool_t	(*x_getbytes)();/* get some bytes from " */
115 		bool_t	(*x_putbytes)();/* put some bytes to " */
116 		u_int	(*x_getpostn)();/* returns bytes off from beginning */
117 		bool_t  (*x_setpostn)();/* lets you reposition the stream */
118 		long *	(*x_inline)();	/* buf quick ptr to buffered data */
119 		void	(*x_destroy)();	/* free privates of this xdr_stream */
120 	} *x_ops;
121 	caddr_t 	x_public;	/* users' data */
122 	caddr_t		x_private;	/* pointer to private data */
123 	caddr_t 	x_base;		/* private used for position info */
124 	int		x_handy;	/* extra private word */
125 } XDR;
126 
127 /*
128  * Operations defined on a XDR handle
129  *
130  * XDR		*xdrs;
131  * long		*longp;
132  * caddr_t	 addr;
133  * u_int	 len;
134  * u_int	 pos;
135  */
136 #define XDR_GETLONG(xdrs, longp)			\
137 	(*(xdrs)->x_ops->x_getlong)(xdrs, longp)
138 #define xdr_getlong(xdrs, longp)			\
139 	(*(xdrs)->x_ops->x_getlong)(xdrs, longp)
140 
141 #define XDR_PUTLONG(xdrs, longp)			\
142 	(*(xdrs)->x_ops->x_putlong)(xdrs, longp)
143 #define xdr_putlong(xdrs, longp)			\
144 	(*(xdrs)->x_ops->x_putlong)(xdrs, longp)
145 
146 #define XDR_GETBYTES(xdrs, addr, len)			\
147 	(*(xdrs)->x_ops->x_getbytes)(xdrs, addr, len)
148 #define xdr_getbytes(xdrs, addr, len)			\
149 	(*(xdrs)->x_ops->x_getbytes)(xdrs, addr, len)
150 
151 #define XDR_PUTBYTES(xdrs, addr, len)			\
152 	(*(xdrs)->x_ops->x_putbytes)(xdrs, addr, len)
153 #define xdr_putbytes(xdrs, addr, len)			\
154 	(*(xdrs)->x_ops->x_putbytes)(xdrs, addr, len)
155 
156 #define XDR_GETPOS(xdrs)				\
157 	(*(xdrs)->x_ops->x_getpostn)(xdrs)
158 #define xdr_getpos(xdrs)				\
159 	(*(xdrs)->x_ops->x_getpostn)(xdrs)
160 
161 #define XDR_SETPOS(xdrs, pos)				\
162 	(*(xdrs)->x_ops->x_setpostn)(xdrs, pos)
163 #define xdr_setpos(xdrs, pos)				\
164 	(*(xdrs)->x_ops->x_setpostn)(xdrs, pos)
165 
166 #define	XDR_INLINE(xdrs, len)				\
167 	(*(xdrs)->x_ops->x_inline)(xdrs, len)
168 #define	xdr_inline(xdrs, len)				\
169 	(*(xdrs)->x_ops->x_inline)(xdrs, len)
170 
171 #define	XDR_DESTROY(xdrs)				\
172 	if ((xdrs)->x_ops->x_destroy) 			\
173 		(*(xdrs)->x_ops->x_destroy)(xdrs)
174 #define	xdr_destroy(xdrs)				\
175 	if ((xdrs)->x_ops->x_destroy) 			\
176 		(*(xdrs)->x_ops->x_destroy)(xdrs)
177 
178 /*
179  * Support struct for discriminated unions.
180  * You create an array of xdrdiscrim structures, terminated with
181  * a entry with a null procedure pointer.  The xdr_union routine gets
182  * the discriminant value and then searches the array of structures
183  * for a matching value.  If a match is found the associated xdr routine
184  * is called to handle that part of the union.  If there is
185  * no match, then a default routine may be called.
186  * If there is no match and no default routine it is an error.
187  */
188 #define NULL_xdrproc_t ((xdrproc_t)0)
189 struct xdr_discrim {
190 	int	value;
191 	xdrproc_t proc;
192 };
193 
194 /*
195  * In-line routines for fast encode/decode of primitve data types.
196  * Caveat emptor: these use single memory cycles to get the
197  * data from the underlying buffer, and will fail to operate
198  * properly if the data is not aligned.  The standard way to use these
199  * is to say:
200  *	if ((buf = XDR_INLINE(xdrs, count)) == NULL)
201  *		return (FALSE);
202  *	<<< macro calls >>>
203  * where ``count'' is the number of bytes of data occupied
204  * by the primitive data types.
205  *
206  * N.B. and frozen for all time: each data type here uses 4 bytes
207  * of external representation.
208  */
209 #define IXDR_GET_LONG(buf)		((long)ntohl((u_long)*(buf)++))
210 #define IXDR_PUT_LONG(buf, v)		(*(buf)++ = (long)htonl((u_long)v))
211 
212 #define IXDR_GET_BOOL(buf)		((bool_t)IXDR_GET_LONG(buf))
213 #define IXDR_GET_ENUM(buf, t)		((t)IXDR_GET_LONG(buf))
214 #define IXDR_GET_U_LONG(buf)		((u_long)IXDR_GET_LONG(buf))
215 #define IXDR_GET_SHORT(buf)		((short)IXDR_GET_LONG(buf))
216 #define IXDR_GET_U_SHORT(buf)		((u_short)IXDR_GET_LONG(buf))
217 
218 #define IXDR_PUT_BOOL(buf, v)		IXDR_PUT_LONG((buf), ((long)(v)))
219 #define IXDR_PUT_ENUM(buf, v)		IXDR_PUT_LONG((buf), ((long)(v)))
220 #define IXDR_PUT_U_LONG(buf, v)		IXDR_PUT_LONG((buf), ((long)(v)))
221 #define IXDR_PUT_SHORT(buf, v)		IXDR_PUT_LONG((buf), ((long)(v)))
222 #define IXDR_PUT_U_SHORT(buf, v)	IXDR_PUT_LONG((buf), ((long)(v)))
223 
224 /*
225  * These are the "generic" xdr routines.
226  */
227 __BEGIN_DECLS
228 extern bool_t	xdr_void	__P((void));
229 extern bool_t	xdr_int		__P((XDR *, int *));
230 extern bool_t	xdr_u_int	__P((XDR *, u_int *));
231 extern bool_t	xdr_long	__P((XDR *, long *));
232 extern bool_t	xdr_u_long	__P((XDR *, u_long *));
233 extern bool_t	xdr_short	__P((XDR *, short *));
234 extern bool_t	xdr_u_short	__P((XDR *, u_short *));
235 extern bool_t	xdr_bool	__P((XDR *, bool_t *));
236 extern bool_t	xdr_enum	__P((XDR *, enum_t *));
237 extern bool_t	xdr_array	__P((XDR *, char **, u_int *, u_int, u_int, xdrproc_t));
238 extern bool_t	xdr_bytes	__P((XDR *, char **, u_int *, u_int));
239 extern bool_t	xdr_opaque	__P((XDR *, caddr_t, u_int));
240 extern bool_t	xdr_string	__P((XDR *, char **, u_int));
241 extern bool_t	xdr_union	__P((XDR *, enum_t *, char *, struct xdr_discrim *, xdrproc_t));
242 extern bool_t	xdr_char	__P((XDR *, char *));
243 extern bool_t	xdr_u_char	__P((XDR *, char *));
244 extern bool_t	xdr_vector	__P((XDR *, char *, u_int, u_int, xdrproc_t));
245 extern bool_t	xdr_float	__P((XDR *, float *));
246 extern bool_t	xdr_double	__P((XDR *, double *));
247 extern bool_t	xdr_reference	__P((XDR *, caddr_t *, u_int, xdrproc_t));
248 extern bool_t	xdr_pointer	__P((XDR *, caddr_t *, u_int, xdrproc_t));
249 extern bool_t	xdr_wrapstring	__P((XDR *, char **));
250 extern void	xdr_free 	__P((xdrproc_t, char *));
251 __END_DECLS
252 
253 /*
254  * Common opaque bytes objects used by many rpc protocols;
255  * declared here due to commonality.
256  */
257 #define MAX_NETOBJ_SZ 1024
258 struct netobj {
259 	u_int	n_len;
260 	char	*n_bytes;
261 };
262 typedef struct netobj netobj;
263 extern bool_t   xdr_netobj();
264 
265 /*
266  * These are the public routines for the various implementations of
267  * xdr streams.
268  */
269 __BEGIN_DECLS
270 /* XDR using memory buffers */
271 extern void   xdrmem_create	__P((XDR *, char *, u_int, enum xdr_op));
272 
273 #ifdef _STDIO_H_
274 /* XDR using stdio library */
275 extern void   xdrstdio_create	__P((XDR *, FILE *, enum xdr_op));
276 #endif
277 
278 /* XDR pseudo records for tcp */
279 extern void   xdrrec_create	__P((XDR *, u_int, u_int, char *, int (*)(), int (*)()));
280 
281 /* make end of xdr record */
282 extern bool_t xdrrec_endofrecord __P((XDR *, int));
283 
284 /* move to beginning of next record */
285 extern bool_t xdrrec_skiprecord	__P((XDR *));
286 
287 /* true if no more input */
288 extern bool_t xdrrec_eof	__P((XDR *));
289 __END_DECLS
290 
291 #endif /* !_RPC_XDR_H */
292