lib/librpc/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 #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__