xref: /original-bsd/lib/librpc/rpc/xdr.h (revision c8f3e141)
1 /* @(#)xdr.h	2.2 88/07/29 4.0 RPCSRC */
2 /*
3  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
4  * unrestricted use provided that this legend is included on all tape
5  * media and as a part of the software program in whole or part.  Users
6  * may copy or modify Sun RPC without charge, but are not authorized
7  * to license or distribute it to anyone else except as part of a product or
8  * program developed by the user.
9  *
10  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
11  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
12  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
13  *
14  * Sun RPC is provided with no support and without any obligation on the
15  * part of Sun Microsystems, Inc. to assist in its use, correction,
16  * modification or enhancement.
17  *
18  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
19  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
20  * OR ANY PART THEREOF.
21  *
22  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
23  * or profits or other special, indirect and consequential damages, even if
24  * Sun has been advised of the possibility of such damages.
25  *
26  * Sun Microsystems, Inc.
27  * 2550 Garcia Avenue
28  * Mountain View, California  94043
29  */
30 /*      @(#)xdr.h 1.19 87/04/22 SMI      */
31 
32 /*
33  * xdr.h, External Data Representation Serialization Routines.
34  *
35  * Copyright (C) 1984, Sun Microsystems, Inc.
36  */
37 
38 #ifndef __XDR_HEADER__
39 #define __XDR_HEADER__
40 
41 /*
42  * XDR provides a conventional way for converting between C data
43  * types and an external bit-string representation.  Library supplied
44  * routines provide for the conversion on built-in C data types.  These
45  * routines and utility routines defined here are used to help implement
46  * a type encode/decode routine for each user-defined type.
47  *
48  * Each data type provides a single procedure which takes two arguments:
49  *
50  *	bool_t
51  *	xdrproc(xdrs, argresp)
52  *		XDR *xdrs;
53  *		<type> *argresp;
54  *
55  * xdrs is an instance of a XDR handle, to which or from which the data
56  * type is to be converted.  argresp is a pointer to the structure to be
57  * converted.  The XDR handle contains an operation field which indicates
58  * which of the operations (ENCODE, DECODE * or FREE) is to be performed.
59  *
60  * XDR_DECODE may allocate space if the pointer argresp is null.  This
61  * data can be freed with the XDR_FREE operation.
62  *
63  * We write only one procedure per data type to make it easy
64  * to keep the encode and decode procedures for a data type consistent.
65  * In many cases the same code performs all operations on a user defined type,
66  * because all the hard work is done in the component type routines.
67  * decode as a series of calls on the nested data types.
68  */
69 
70 /*
71  * Xdr operations.  XDR_ENCODE causes the type to be encoded into the
72  * stream.  XDR_DECODE causes the type to be extracted from the stream.
73  * XDR_FREE can be used to release the space allocated by an XDR_DECODE
74  * request.
75  */
76 enum xdr_op {
77 	XDR_ENCODE=0,
78 	XDR_DECODE=1,
79 	XDR_FREE=2
80 };
81 
82 /*
83  * This is the number of bytes per unit of external data.
84  */
85 #define BYTES_PER_XDR_UNIT	(4)
86 #define RNDUP(x)  ((((x) + BYTES_PER_XDR_UNIT - 1) / BYTES_PER_XDR_UNIT) \
87 		    * BYTES_PER_XDR_UNIT)
88 
89 /*
90  * A xdrproc_t exists for each data type which is to be encoded or decoded.
91  *
92  * The second argument to the xdrproc_t is a pointer to an opaque pointer.
93  * The opaque pointer generally points to a structure of the data type
94  * to be decoded.  If this pointer is 0, then the type routines should
95  * allocate dynamic storage of the appropriate size and return it.
96  * bool_t	(*xdrproc_t)(XDR *, caddr_t *);
97  */
98 typedef	bool_t (*xdrproc_t)();
99 
100 /*
101  * The XDR handle.
102  * Contains operation which is being applied to the stream,
103  * an operations vector for the paticular implementation (e.g. see xdr_mem.c),
104  * and two private fields for the use of the particular impelementation.
105  */
106 typedef struct {
107 	enum xdr_op	x_op;		/* operation; fast additional param */
108 	struct xdr_ops {
109 		bool_t	(*x_getlong)();	/* get a long from underlying stream */
110 		bool_t	(*x_putlong)();	/* put a long to " */
111 		bool_t	(*x_getbytes)();/* get some bytes from " */
112 		bool_t	(*x_putbytes)();/* put some bytes to " */
113 		u_int	(*x_getpostn)();/* returns bytes off from beginning */
114 		bool_t  (*x_setpostn)();/* lets you reposition the stream */
115 		long *	(*x_inline)();	/* buf quick ptr to buffered data */
116 		void	(*x_destroy)();	/* free privates of this xdr_stream */
117 	} *x_ops;
118 	caddr_t 	x_public;	/* users' data */
119 	caddr_t		x_private;	/* pointer to private data */
120 	caddr_t 	x_base;		/* private used for position info */
121 	int		x_handy;	/* extra private word */
122 } XDR;
123 
124 /*
125  * Operations defined on a XDR handle
126  *
127  * XDR		*xdrs;
128  * long		*longp;
129  * caddr_t	 addr;
130  * u_int	 len;
131  * u_int	 pos;
132  */
133 #define XDR_GETLONG(xdrs, longp)			\
134 	(*(xdrs)->x_ops->x_getlong)(xdrs, longp)
135 #define xdr_getlong(xdrs, longp)			\
136 	(*(xdrs)->x_ops->x_getlong)(xdrs, longp)
137 
138 #define XDR_PUTLONG(xdrs, longp)			\
139 	(*(xdrs)->x_ops->x_putlong)(xdrs, longp)
140 #define xdr_putlong(xdrs, longp)			\
141 	(*(xdrs)->x_ops->x_putlong)(xdrs, longp)
142 
143 #define XDR_GETBYTES(xdrs, addr, len)			\
144 	(*(xdrs)->x_ops->x_getbytes)(xdrs, addr, len)
145 #define xdr_getbytes(xdrs, addr, len)			\
146 	(*(xdrs)->x_ops->x_getbytes)(xdrs, addr, len)
147 
148 #define XDR_PUTBYTES(xdrs, addr, len)			\
149 	(*(xdrs)->x_ops->x_putbytes)(xdrs, addr, len)
150 #define xdr_putbytes(xdrs, addr, len)			\
151 	(*(xdrs)->x_ops->x_putbytes)(xdrs, addr, len)
152 
153 #define XDR_GETPOS(xdrs)				\
154 	(*(xdrs)->x_ops->x_getpostn)(xdrs)
155 #define xdr_getpos(xdrs)				\
156 	(*(xdrs)->x_ops->x_getpostn)(xdrs)
157 
158 #define XDR_SETPOS(xdrs, pos)				\
159 	(*(xdrs)->x_ops->x_setpostn)(xdrs, pos)
160 #define xdr_setpos(xdrs, pos)				\
161 	(*(xdrs)->x_ops->x_setpostn)(xdrs, pos)
162 
163 #define	XDR_INLINE(xdrs, len)				\
164 	(*(xdrs)->x_ops->x_inline)(xdrs, len)
165 #define	xdr_inline(xdrs, len)				\
166 	(*(xdrs)->x_ops->x_inline)(xdrs, len)
167 
168 #define	XDR_DESTROY(xdrs)				\
169 	if ((xdrs)->x_ops->x_destroy) 			\
170 		(*(xdrs)->x_ops->x_destroy)(xdrs)
171 #define	xdr_destroy(xdrs)				\
172 	if ((xdrs)->x_ops->x_destroy) 			\
173 		(*(xdrs)->x_ops->x_destroy)(xdrs)
174 
175 /*
176  * Support struct for discriminated unions.
177  * You create an array of xdrdiscrim structures, terminated with
178  * a entry with a null procedure pointer.  The xdr_union routine gets
179  * the discriminant value and then searches the array of structures
180  * for a matching value.  If a match is found the associated xdr routine
181  * is called to handle that part of the union.  If there is
182  * no match, then a default routine may be called.
183  * If there is no match and no default routine it is an error.
184  */
185 #define NULL_xdrproc_t ((xdrproc_t)0)
186 struct xdr_discrim {
187 	int	value;
188 	xdrproc_t proc;
189 };
190 
191 /*
192  * In-line routines for fast encode/decode of primitve data types.
193  * Caveat emptor: these use single memory cycles to get the
194  * data from the underlying buffer, and will fail to operate
195  * properly if the data is not aligned.  The standard way to use these
196  * is to say:
197  *	if ((buf = XDR_INLINE(xdrs, count)) == NULL)
198  *		return (FALSE);
199  *	<<< macro calls >>>
200  * where ``count'' is the number of bytes of data occupied
201  * by the primitive data types.
202  *
203  * N.B. and frozen for all time: each data type here uses 4 bytes
204  * of external representation.
205  */
206 #define IXDR_GET_LONG(buf)		((long)ntohl((u_long)*(buf)++))
207 #define IXDR_PUT_LONG(buf, v)		(*(buf)++ = (long)htonl((u_long)v))
208 
209 #define IXDR_GET_BOOL(buf)		((bool_t)IXDR_GET_LONG(buf))
210 #define IXDR_GET_ENUM(buf, t)		((t)IXDR_GET_LONG(buf))
211 #define IXDR_GET_U_LONG(buf)		((u_long)IXDR_GET_LONG(buf))
212 #define IXDR_GET_SHORT(buf)		((short)IXDR_GET_LONG(buf))
213 #define IXDR_GET_U_SHORT(buf)		((u_short)IXDR_GET_LONG(buf))
214 
215 #define IXDR_PUT_BOOL(buf, v)		IXDR_PUT_LONG((buf), ((long)(v)))
216 #define IXDR_PUT_ENUM(buf, v)		IXDR_PUT_LONG((buf), ((long)(v)))
217 #define IXDR_PUT_U_LONG(buf, v)		IXDR_PUT_LONG((buf), ((long)(v)))
218 #define IXDR_PUT_SHORT(buf, v)		IXDR_PUT_LONG((buf), ((long)(v)))
219 #define IXDR_PUT_U_SHORT(buf, v)	IXDR_PUT_LONG((buf), ((long)(v)))
220 
221 /*
222  * These are the "generic" xdr routines.
223  */
224 extern bool_t	xdr_void();
225 extern bool_t	xdr_int();
226 extern bool_t	xdr_u_int();
227 extern bool_t	xdr_long();
228 extern bool_t	xdr_u_long();
229 extern bool_t	xdr_short();
230 extern bool_t	xdr_u_short();
231 extern bool_t	xdr_bool();
232 extern bool_t	xdr_enum();
233 extern bool_t	xdr_array();
234 extern bool_t	xdr_bytes();
235 extern bool_t	xdr_opaque();
236 extern bool_t	xdr_string();
237 extern bool_t	xdr_union();
238 extern bool_t	xdr_char();
239 extern bool_t	xdr_u_char();
240 extern bool_t	xdr_vector();
241 extern bool_t	xdr_float();
242 extern bool_t	xdr_double();
243 extern bool_t	xdr_reference();
244 extern bool_t	xdr_pointer();
245 extern bool_t	xdr_wrapstring();
246 
247 /*
248  * Common opaque bytes objects used by many rpc protocols;
249  * declared here due to commonality.
250  */
251 #define MAX_NETOBJ_SZ 1024
252 struct netobj {
253 	u_int	n_len;
254 	char	*n_bytes;
255 };
256 typedef struct netobj netobj;
257 extern bool_t   xdr_netobj();
258 
259 /*
260  * These are the public routines for the various implementations of
261  * xdr streams.
262  */
263 extern void   xdrmem_create();		/* XDR using memory buffers */
264 extern void   xdrstdio_create();	/* XDR using stdio library */
265 extern void   xdrrec_create();		/* XDR pseudo records for tcp */
266 extern bool_t xdrrec_endofrecord();	/* make end of xdr record */
267 extern bool_t xdrrec_skiprecord();	/* move to beginning of next record */
268 extern bool_t xdrrec_eof();		/* true if no more input */
269 
270 #endif !__XDR_HEADER__
271