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 _RPC_XDR_H
  39 #define _RPC_XDR_H 1
  40
  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   {
  87     XDR_ENCODE = 0,
  88     XDR_DECODE = 1,
  89     XDR_FREE = 2
  90   };
  91
  92 /*
  93  * This is the number of bytes per unit of external data.
  94  */
  95 #define BYTES_PER_XDR_UNIT      (4)
  96 /*
  97  * This only works if the above is a power of 2.  But it's defined to be
  98  * 4 by the appropriate RFCs.  So it will work.  And it's normally quicker
  99  * than the old routine.
 100  */
 101 #if 1
 102 #define RNDUP(x)  (((x) + BYTES_PER_XDR_UNIT - 1) & ~(BYTES_PER_XDR_UNIT - 1))
 103 #else /* this is the old routine */
 104 #define RNDUP(x)  ((((x) + BYTES_PER_XDR_UNIT - 1) / BYTES_PER_XDR_UNIT) \
 105                     * BYTES_PER_XDR_UNIT)
 106 #endif
 107
 108 /*
 109  * The XDR handle.
 110  * Contains operation which is being applied to the stream,
 111  * an operations vector for the particular implementation (e.g. see xdr_mem.c),
 112  * and two private fields for the use of the particular implementation.
 113  */
 114 typedef struct XDR XDR;
 115 struct XDR
 116   {
 117     enum xdr_op x_op;           /* operation; fast additional param */
 118     struct xdr_ops
 119       {
 120         bool_t (*x_getlong) __PMT ((XDR * __xdrs, long *__lp));
 121         /* get a long from underlying stream */
 122         bool_t (*x_putlong) __PMT ((XDR * __xdrs, __const long *__lp));
 123         /* put a long to " */
 124         bool_t (*x_getbytes) __PMT ((XDR * __xdrs, caddr_t __addr,
 125                                      u_int __len));
 126         /* get some bytes from " */
 127         bool_t (*x_putbytes) __PMT ((XDR * __xdrs, __const char *__addr,
 128                                      u_int __len));
 129         /* put some bytes to " */
 130         u_int (*x_getpostn) __PMT ((__const XDR * __xdrs));
 131         /* returns bytes off from beginning */
 132         bool_t (*x_setpostn) __PMT ((XDR * __xdrs, u_int pos));
 133         /* lets you reposition the stream */
 134         long *(*x_inline) __PMT ((XDR * __xdrs, int len));
 135         /* buf quick ptr to buffered data */
 136         void (*x_destroy) __PMT ((XDR * __xdrs));
 137         /* free privates of this xdr_stream */
 138       }
 139      *x_ops;
 140     caddr_t x_public;           /* users' data */
 141     caddr_t x_private;          /* pointer to private data */
 142     caddr_t x_base;             /* private used for position info */
 143     int x_handy;                /* extra private word */
 144   };
 145
 146 /*
 147  * A xdrproc_t exists for each data type which is to be encoded or decoded.
 148  *
 149  * The second argument to the xdrproc_t is a pointer to an opaque pointer.
 150  * The opaque pointer generally points to a structure of the data type
 151  * to be decoded.  If this pointer is 0, then the type routines should
 152  * allocate dynamic storage of the appropriate size and return it.
 153  * bool_t       (*xdrproc_t)(XDR *, caddr_t *);
 154  */
 155 typedef bool_t (*xdrproc_t) __PMT ((XDR *, void *,...));
 156
 157 /*
 158  * Operations defined on a XDR handle
 159  *
 160  * XDR          *xdrs;
 161  * long         *longp;
 162  * caddr_t       addr;
 163  * u_int         len;
 164  * u_int         pos;
 165  */
 166 #define XDR_GETLONG(xdrs, longp)                        \
 167         (*(xdrs)->x_ops->x_getlong)(xdrs, longp)
 168 #define xdr_getlong(xdrs, longp)                        \
 169         (*(xdrs)->x_ops->x_getlong)(xdrs, longp)
 170
 171 #define XDR_PUTLONG(xdrs, longp)                        \
 172         (*(xdrs)->x_ops->x_putlong)(xdrs, longp)
 173 #define xdr_putlong(xdrs, longp)                        \
 174         (*(xdrs)->x_ops->x_putlong)(xdrs, longp)
 175
 176 #define XDR_GETBYTES(xdrs, addr, len)                   \
 177         (*(xdrs)->x_ops->x_getbytes)(xdrs, addr, len)
 178 #define xdr_getbytes(xdrs, addr, len)                   \
 179         (*(xdrs)->x_ops->x_getbytes)(xdrs, addr, len)
 180
 181 #define XDR_PUTBYTES(xdrs, addr, len)                   \
 182         (*(xdrs)->x_ops->x_putbytes)(xdrs, addr, len)
 183 #define xdr_putbytes(xdrs, addr, len)                   \
 184         (*(xdrs)->x_ops->x_putbytes)(xdrs, addr, len)
 185
 186 #define XDR_GETPOS(xdrs)                                \
 187         (*(xdrs)->x_ops->x_getpostn)(xdrs)
 188 #define xdr_getpos(xdrs)                                \
 189         (*(xdrs)->x_ops->x_getpostn)(xdrs)
 190
 191 #define XDR_SETPOS(xdrs, pos)                           \
 192         (*(xdrs)->x_ops->x_setpostn)(xdrs, pos)
 193 #define xdr_setpos(xdrs, pos)                           \
 194         (*(xdrs)->x_ops->x_setpostn)(xdrs, pos)
 195
 196 #define XDR_INLINE(xdrs, len)                           \
 197         (*(xdrs)->x_ops->x_inline)(xdrs, len)
 198 #define xdr_inline(xdrs, len)                           \
 199         (*(xdrs)->x_ops->x_inline)(xdrs, len)
 200
 201 #define XDR_DESTROY(xdrs)                               \
 202         if ((xdrs)->x_ops->x_destroy)                   \
 203                 (*(xdrs)->x_ops->x_destroy)(xdrs)
 204 #define xdr_destroy(xdrs)                               \
 205         if ((xdrs)->x_ops->x_destroy)                   \
 206                 (*(xdrs)->x_ops->x_destroy)(xdrs)
 207
 208 /*
 209  * Support struct for discriminated unions.
 210  * You create an array of xdrdiscrim structures, terminated with
 211  * a entry with a null procedure pointer.  The xdr_union routine gets
 212  * the discriminant value and then searches the array of structures
 213  * for a matching value.  If a match is found the associated xdr routine
 214  * is called to handle that part of the union.  If there is
 215  * no match, then a default routine may be called.
 216  * If there is no match and no default routine it is an error.
 217  */
 218 #define NULL_xdrproc_t ((xdrproc_t)0)
 219 struct xdr_discrim
 220 {
 221   int value;
 222   xdrproc_t proc;
 223 };
 224
 225 /*
 226  * Inline routines for fast encode/decode of primitive data types.
 227  * Caveat emptor: these use single memory cycles to get the
 228  * data from the underlying buffer, and will fail to operate
 229  * properly if the data is not aligned.  The standard way to use these
 230  * is to say:
 231  *      if ((buf = XDR_INLINE(xdrs, count)) == NULL)
 232  *              return (FALSE);
 233  *      <<< macro calls >>>
 234  * where ``count'' is the number of bytes of data occupied
 235  * by the primitive data types.
 236  *
 237  * N.B. and frozen for all time: each data type here uses 4 bytes
 238  * of external representation.
 239  */
 240 #define IXDR_GET_LONG(buf)              ((long)ntohl((u_long)*((u_int32_t*)buf)++))
 241 #define IXDR_PUT_LONG(buf, v)           (*((u_int32_t*)(buf))++ = (long)htonl((u_long)v))
 242
 243 #define IXDR_GET_BOOL(buf)              ((bool_t)IXDR_GET_LONG(buf))
 244 #define IXDR_GET_ENUM(buf, t)           ((t)IXDR_GET_LONG(buf))
 245 #define IXDR_GET_U_LONG(buf)            ((u_long)IXDR_GET_LONG(buf))
 246 #define IXDR_GET_SHORT(buf)             ((short)IXDR_GET_LONG(buf))
 247 #define IXDR_GET_U_SHORT(buf)           ((u_short)IXDR_GET_LONG(buf))
 248
 249 #define IXDR_PUT_BOOL(buf, v)           IXDR_PUT_LONG((buf), ((long)(v)))
 250 #define IXDR_PUT_ENUM(buf, v)           IXDR_PUT_LONG((buf), ((long)(v)))
 251 #define IXDR_PUT_U_LONG(buf, v)         IXDR_PUT_LONG((buf), ((long)(v)))
 252 #define IXDR_PUT_SHORT(buf, v)          IXDR_PUT_LONG((buf), ((long)(v)))
 253 #define IXDR_PUT_U_SHORT(buf, v)        IXDR_PUT_LONG((buf), ((long)(v)))
 254
 255 /*
 256  * These are the "generic" xdr routines.
 257  * None of these can have const applied because it's not possible to
 258  * know whether the call is a read or a write to the passed parameter
 259  * also, the XDR structure is always updated by some of these calls.
 260  */
 261 extern bool_t xdr_void __P ((void));
 262 extern bool_t xdr_int __P ((XDR * __xdrs, int *__ip));
 263 extern bool_t xdr_u_int __P ((XDR * __xdrs, u_int * __up));
 264 extern bool_t xdr_long __P ((XDR * __xdrs, long *__lp));
 265 extern bool_t xdr_u_long __P ((XDR * __xdrs, u_long * __ulp));
 266 extern bool_t xdr_short __P ((XDR * __xdrs, short *__sp));
 267 extern bool_t xdr_u_short __P ((XDR * __xdrs, u_short * __usp));
 268 extern bool_t xdr_bool __P ((XDR * __xdrs, bool_t * __bp));
 269 extern bool_t xdr_enum __P ((XDR * __xdrs, enum_t * __ep));
 270 extern bool_t xdr_array __P ((XDR * _xdrs, caddr_t * __addrp, u_int * __sizep,
 271                               u_int __maxsize, u_int __elsize,
 272                               xdrproc_t __elproc));
 273 extern bool_t xdr_bytes __P ((XDR * __xdrs, char **__cpp, u_int * __sizep,
 274                               u_int __maxsize));
 275 extern bool_t xdr_opaque __P ((XDR * __xdrs, caddr_t __cp, u_int __cnt));
 276 extern bool_t xdr_string __P ((XDR * __xdrs, char **__cpp, u_int __maxsize));
 277 extern bool_t xdr_union __P ((XDR * __xdrs, enum_t * __dscmp, char *__unp,
 278                               __const struct xdr_discrim * __choices,
 279                               xdrproc_t dfault));
 280 extern bool_t xdr_char __P ((XDR * __xdrs, char *__cp));
 281 extern bool_t xdr_u_char __P ((XDR * __xdrs, u_char * __cp));
 282 extern bool_t xdr_vector __P ((XDR * __xdrs, char *__basep, u_int __nelem,
 283                                u_int __elemsize, xdrproc_t __xdr_elem));
 284 extern bool_t xdr_float __P ((XDR * __xdrs, float *__fp));
 285 extern bool_t xdr_double __P ((XDR * __xdrs, double *__dp));
 286 extern bool_t xdr_reference __P ((XDR * __xdrs, caddr_t * __xpp, u_int __size,
 287                                   xdrproc_t __proc));
 288 extern bool_t xdr_pointer __P ((XDR * __xdrs, char **__objpp,
 289                                 u_int __obj_size, xdrproc_t __xdr_obj));
 290 extern bool_t xdr_wrapstring __P ((XDR * __xdrs, char **__cpp));
 291 extern u_long xdr_sizeof __P ((xdrproc_t, void *));
 292
 293 /*
 294  * Common opaque bytes objects used by many rpc protocols;
 295  * declared here due to commonality.
 296  */
 297 #define MAX_NETOBJ_SZ 1024
 298 struct netobj
 299 {
 300   u_int n_len;
 301   char *n_bytes;
 302 };
 303 typedef struct netobj netobj;
 304 extern bool_t xdr_netobj __P ((XDR * __xdrs, struct netobj * __np));
 305
 306 /*
 307  * These are the public routines for the various implementations of
 308  * xdr streams.
 309  */
 310
 311 /* XDR using memory buffers */
 312 extern void xdrmem_create __P ((XDR * __xdrs, __const caddr_t __addr,
 313                                 u_int __size, enum xdr_op __xop));
 314
 315 /* XDR using stdio library */
 316 extern void xdrstdio_create __P ((XDR * __xdrs, FILE * __file,
 317                                   enum xdr_op __xop));
 318
 319 /* XDR pseudo records for tcp */
 320 extern void xdrrec_create __P ((XDR * __xdrs, u_int __sendsize,
 321                                 u_int __recvsize, caddr_t __tcp_handle,
 322                                 int (*__readit) (char *, char *, int),
 323                                 int (*__writeit) (char *, char *, int)));
 324
 325 /* make end of xdr record */
 326 extern bool_t xdrrec_endofrecord __P ((XDR * __xdrs, bool_t __sendnow));
 327
 328 /* move to beginning of next record */
 329 extern bool_t xdrrec_skiprecord __P ((XDR * __xdrs));
 330
 331 /* true if no more input */
 332 extern bool_t xdrrec_eof __P ((XDR * __xdrs));
 333
 334 /* free memory buffers for xdr */
 335 extern void xdr_free __P ((xdrproc_t __proc, char *__objp));
 336
 337 __END_DECLS
 338
 339 #endif /* rpc/xdr.h */