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