sunrpc/rpc/xdr.h

   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
  40 #define __XDR_HEADER__
  41 #include <features.h>
  42 #include <sys/types.h>
  43 #include <rpc/types.h>
  44
  45 /* We need FILE.  */
  46 #include <stdio.h>
  47
  48 __BEGIN_DECLS
  49
  50 /*
  51  * XDR provides a conventional way for converting between C data
  52  * types and an external bit-string representation.  Library supplied
  53  * routines provide for the conversion on built-in C data types.  These
  54  * routines and utility routines defined here are used to help implement
  55  * a type encode/decode routine for each user-defined type.
  56  *
  57  * Each data type provides a single procedure which takes two arguments:
  58  *
  59  *      bool_t
  60  *      xdrproc(xdrs, argresp)
  61  *              XDR *xdrs;
  62  *              <type> *argresp;
  63  *
  64  * xdrs is an instance of a XDR handle, to which or from which the data
  65  * type is to be converted.  argresp is a pointer to the structure to be
  66  * converted.  The XDR handle contains an operation field which indicates
  67  * which of the operations (ENCODE, DECODE * or FREE) is to be performed.
  68  *
  69  * XDR_DECODE may allocate space if the pointer argresp is null.  This
  70  * data can be freed with the XDR_FREE operation.
  71  *
  72  * We write only one procedure per data type to make it easy
  73  * to keep the encode and decode procedures for a data type consistent.
  74  * In many cases the same code performs all operations on a user defined type,
  75  * because all the hard work is done in the component type routines.
  76  * decode as a series of calls on the nested data types.
  77  */
  78
  79 /*
  80  * Xdr operations.  XDR_ENCODE causes the type to be encoded into the
  81  * stream.  XDR_DECODE causes the type to be extracted from the stream.
  82  * XDR_FREE can be used to release the space allocated by an XDR_DECODE
  83  * request.
  84  */
  85 enum xdr_op {
  86         XDR_ENCODE=0,
  87         XDR_DECODE=1,
  88         XDR_FREE=2
  89 };
  90
  91 /*
  92  * This is the number of bytes per unit of external data.
  93  */
  94 #define BYTES_PER_XDR_UNIT      (4)
  95 #define RNDUP(x)  ((((x) + BYTES_PER_XDR_UNIT - 1) / BYTES_PER_XDR_UNIT) \
  96                     * BYTES_PER_XDR_UNIT)
  97
  98 /*
  99  * The XDR handle.
 100  * Contains operation which is being applied to the stream,
 101  * an operations vector for the particular implementation (e.g. see xdr_mem.c),
 102  * and two private fields for the use of the particular implementation.
 103  */
 104 typedef struct XDR XDR;
 105 struct XDR
 106   {
 107     enum xdr_op x_op;           /* operation; fast additional param */
 108     const struct xdr_ops
 109       {
 110         bool_t (*x_getlong) __P ((XDR * __xdrs, long *__lp));
 111         /* get a long from underlying stream */
 112         bool_t (*x_putlong) __P ((XDR * __xdrs, __const long *__lp));
 113         /* put a long to " */
 114         bool_t (*x_getbytes) __P ((XDR * __xdrs, caddr_t __addr, u_int __len));
 115         /* get some bytes from " */
 116         bool_t (*x_putbytes) __P ((XDR * __xdrs, __const char *__addr,
 117                                    u_int __len));
 118         /* put some bytes to " */
 119         u_int (*x_getpostn) __P ((__const XDR * __xdrs));
 120         /* returns bytes off from beginning */
 121         bool_t (*x_setpostn) __P ((XDR * __xdrs, u_int pos));
 122         /* lets you reposition the stream */
 123         long *(*x_inline) __P ((XDR * __xdrs, int len));
 124         /* buf quick ptr to buffered data */
 125         void (*x_destroy) __P ((XDR * __xdrs));
 126         /* free privates of this xdr_stream */
 127       }
 128      *x_ops;
 129     caddr_t x_public;           /* users' data */
 130     caddr_t x_private;          /* pointer to private data */
 131     caddr_t x_base;             /* private used for position info */
 132     int x_handy;                /* extra private word */
 133   };
 134
 135 /*
 136  * A xdrproc_t exists for each data type which is to be encoded or decoded.
 137  *
 138  * The second argument to the xdrproc_t is a pointer to an opaque pointer.
 139  * The opaque pointer generally points to a structure of the data type
 140  * to be decoded.  If this pointer is 0, then the type routines should
 141  * allocate dynamic storage of the appropriate size and return it.
 142  * bool_t       (*xdrproc_t)(XDR *, caddr_t *);
 143  */
 144 typedef bool_t (*xdrproc_t) __P ((XDR *, void *, ...));
 145
 146 /*
 147  * Operations defined on a XDR handle
 148  *
 149  * XDR          *xdrs;
 150  * long         *longp;
 151  * caddr_t       addr;
 152  * u_int         len;
 153  * u_int         pos;
 154  */
 155 #define XDR_GETLONG(xdrs, longp)                        \
 156         (*(xdrs)->x_ops->x_getlong)(xdrs, longp)
 157 #define xdr_getlong(xdrs, longp)                        \
 158         (*(xdrs)->x_ops->x_getlong)(xdrs, longp)
 159
 160 #define XDR_PUTLONG(xdrs, longp)                        \
 161         (*(xdrs)->x_ops->x_putlong)(xdrs, longp)
 162 #define xdr_putlong(xdrs, longp)                        \
 163         (*(xdrs)->x_ops->x_putlong)(xdrs, longp)
 164
 165 #define XDR_GETBYTES(xdrs, addr, len)                   \
 166         (*(xdrs)->x_ops->x_getbytes)(xdrs, addr, len)
 167 #define xdr_getbytes(xdrs, addr, len)                   \
 168         (*(xdrs)->x_ops->x_getbytes)(xdrs, addr, len)
 169
 170 #define XDR_PUTBYTES(xdrs, addr, len)                   \
 171         (*(xdrs)->x_ops->x_putbytes)(xdrs, addr, len)
 172 #define xdr_putbytes(xdrs, addr, len)                   \
 173         (*(xdrs)->x_ops->x_putbytes)(xdrs, addr, len)
 174
 175 #define XDR_GETPOS(xdrs)                                \
 176         (*(xdrs)->x_ops->x_getpostn)(xdrs)
 177 #define xdr_getpos(xdrs)                                \
 178         (*(xdrs)->x_ops->x_getpostn)(xdrs)
 179
 180 #define XDR_SETPOS(xdrs, pos)                           \
 181         (*(xdrs)->x_ops->x_setpostn)(xdrs, pos)
 182 #define xdr_setpos(xdrs, pos)                           \
 183         (*(xdrs)->x_ops->x_setpostn)(xdrs, pos)
 184
 185 #define XDR_INLINE(xdrs, len)                           \
 186         (*(xdrs)->x_ops->x_inline)(xdrs, len)
 187 #define xdr_inline(xdrs, len)                           \
 188         (*(xdrs)->x_ops->x_inline)(xdrs, len)
 189
 190 #define XDR_DESTROY(xdrs)                               \
 191         if ((xdrs)->x_ops->x_destroy)                   \
 192                 (*(xdrs)->x_ops->x_destroy)(xdrs)
 193 #define xdr_destroy(xdrs)                               \
 194         if ((xdrs)->x_ops->x_destroy)                   \
 195                 (*(xdrs)->x_ops->x_destroy)(xdrs)
 196
 197 /*
 198  * Support struct for discriminated unions.
 199  * You create an array of xdrdiscrim structures, terminated with
 200  * a entry with a null procedure pointer.  The xdr_union routine gets
 201  * the discriminant value and then searches the array of structures
 202  * for a matching value.  If a match is found the associated xdr routine
 203  * is called to handle that part of the union.  If there is
 204  * no match, then a default routine may be called.
 205  * If there is no match and no default routine it is an error.
 206  */
 207 #define NULL_xdrproc_t ((xdrproc_t)0)
 208 struct xdr_discrim {
 209         int     value;
 210         xdrproc_t proc;
 211 };
 212
 213 /*
 214  * Inline routines for fast encode/decode of primitive data types.
 215  * Caveat emptor: these use single memory cycles to get the
 216  * data from the underlying buffer, and will fail to operate
 217  * properly if the data is not aligned.  The standard way to use these
 218  * is to say:
 219  *      if ((buf = XDR_INLINE(xdrs, count)) == NULL)
 220  *              return (FALSE);
 221  *      <<< macro calls >>>
 222  * where ``count'' is the number of bytes of data occupied
 223  * by the primitive data types.
 224  *
 225  * N.B. and frozen for all time: each data type here uses 4 bytes
 226  * of external representation.
 227  */
 228 #define IXDR_GET_LONG(buf)              ((long)ntohl((u_long)*((u_int32_t*)buf)++))
 229 #define IXDR_PUT_LONG(buf, v)           (*((u_int32_t*)(buf))++ = (long)htonl((u_long)v))
 230
 231 #define IXDR_GET_BOOL(buf)              ((bool_t)IXDR_GET_LONG(buf))
 232 #define IXDR_GET_ENUM(buf, t)           ((t)IXDR_GET_LONG(buf))
 233 #define IXDR_GET_U_LONG(buf)            ((u_long)IXDR_GET_LONG(buf))
 234 #define IXDR_GET_SHORT(buf)             ((short)IXDR_GET_LONG(buf))
 235 #define IXDR_GET_U_SHORT(buf)           ((u_short)IXDR_GET_LONG(buf))
 236
 237 #define IXDR_PUT_BOOL(buf, v)           IXDR_PUT_LONG((buf), ((long)(v)))
 238 #define IXDR_PUT_ENUM(buf, v)           IXDR_PUT_LONG((buf), ((long)(v)))
 239 #define IXDR_PUT_U_LONG(buf, v)         IXDR_PUT_LONG((buf), ((long)(v)))
 240 #define IXDR_PUT_SHORT(buf, v)          IXDR_PUT_LONG((buf), ((long)(v)))
 241 #define IXDR_PUT_U_SHORT(buf, v)        IXDR_PUT_LONG((buf), ((long)(v)))
 242
 243 /*
 244  * These are the "generic" xdr routines.
 245  */
 246 extern bool_t   xdr_void __P ((void));
 247 extern bool_t   xdr_int __P ((XDR *__xdrs, int *__ip));
 248 extern bool_t   xdr_u_int __P ((XDR *__xdrs, u_int *__up));
 249 extern bool_t   xdr_long __P ((XDR *__xdrs, long *__lp));
 250 extern bool_t   xdr_u_long __P ((XDR *__xdrs, u_long *__ulp));
 251 extern bool_t   xdr_short __P ((XDR *__xdrs, short *__sp));
 252 extern bool_t   xdr_u_short __P ((XDR *__xdrs, u_short *__usp));
 253 extern bool_t   xdr_bool __P ((XDR *__xdrs, bool_t *__bp));
 254 extern bool_t   xdr_enum __P ((XDR *__xdrs, enum_t *__ep));
 255 extern bool_t   xdr_array __P ((XDR *_xdrs, caddr_t *__addrp, u_int *__sizep,
 256                                 u_int __maxsize, u_int __elsize,
 257                                 xdrproc_t __elproc));
 258 extern bool_t   xdr_bytes __P ((XDR *__xdrs, char **__cpp, u_int *__sizep,
 259                                 u_int __maxsize));
 260 extern bool_t   xdr_opaque __P ((XDR *__xdrs, caddr_t __cp, u_int __cnt));
 261 extern bool_t   xdr_string __P ((XDR *__xdrs, char **__cpp, u_int __maxsize));
 262 extern bool_t   xdr_union __P ((XDR *__xdrs, enum_t *__dscmp, char *__unp,
 263                                 struct xdr_discrim *__choices,
 264                                 xdrproc_t dfault));
 265 extern bool_t   xdr_char __P ((XDR *__xdrs, char *__cp));
 266 extern bool_t   xdr_u_char __P ((XDR *__xdrs, u_char *__cp));
 267 extern bool_t   xdr_vector __P ((XDR *__xdrs, char *__basep, u_int __nelem,
 268                                  u_int __elemsize, xdrproc_t __xdr_elem));
 269 extern bool_t   xdr_float __P ((XDR *__xdrs, float *__fp));
 270 extern bool_t   xdr_double __P ((XDR *__xdrs, double *__dp));
 271 extern bool_t   xdr_reference __P ((XDR *__xdrs, caddr_t *__xpp, u_int __size,
 272                                     xdrproc_t __proc));
 273 extern bool_t   xdr_pointer __P ((XDR *__xdrs, char **__objpp,
 274                                   u_int __obj_size, xdrproc_t __xdr_obj));
 275 extern bool_t   xdr_wrapstring __P ((XDR *__xdrs, char **__cpp));
 276
 277 /*
 278  * Common opaque bytes objects used by many rpc protocols;
 279  * declared here due to commonality.
 280  */
 281 #define MAX_NETOBJ_SZ 1024
 282 struct netobj {
 283         u_int   n_len;
 284         char    *n_bytes;
 285 };
 286 typedef struct netobj netobj;
 287 extern bool_t   xdr_netobj __P ((XDR *__xdrs, struct netobj *__np));
 288
 289 /*
 290  * These are the public routines for the various implementations of
 291  * xdr streams.
 292  */
 293
 294 /* XDR using memory buffers */
 295 extern void   xdrmem_create __P ((XDR *__xdrs, caddr_t __addr, u_int __size,
 296                                   enum xdr_op __xop));
 297
 298 /* XDR using stdio library */
 299 extern void   xdrstdio_create __P ((XDR *__xdrs, FILE *__file,
 300                                     enum xdr_op __xop));
 301
 302 /* XDR pseudo records for tcp */
 303 extern void   xdrrec_create __P ((XDR *__xdrs, u_int __sendsize,
 304                                   u_int __recvsize, caddr_t __tcp_handle,
 305                                   int (*__readit) (char *, char *, int),
 306                                   int (*__writeit) (char *, char *, int)));
 307
 308 /* make end of xdr record */
 309 extern bool_t xdrrec_endofrecord __P ((XDR *__xdrs, bool_t __sendnow));
 310
 311 /* move to beginning of next record */
 312 extern bool_t xdrrec_skiprecord __P ((XDR *__xdrs));
 313
 314 /* true if no more input */
 315 extern bool_t xdrrec_eof __P ((XDR *__xdrs));
 316
 317 /* free memory buffers for xdr */
 318 extern void xdr_free __P ((xdrproc_t __proc, char *__objp));
 319
 320 __END_DECLS
 321
 322 #endif /* !__XDR_HEADER__ */