sunrpc/xdr.c

   1 /* @(#)xdr.c    2.1 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 #if !defined(lint) && defined(SCCSIDS)
  31 static char sccsid[] = "@(#)xdr.c 1.35 87/08/12";
  32 #endif
  33
  34 /*
  35  * xdr.c, Generic XDR routines implementation.
  36  *
  37  * Copyright (C) 1986, Sun Microsystems, Inc.
  38  *
  39  * These are the "generic" xdr routines used to serialize and de-serialize
  40  * most common data items.  See xdr.h for more info on the interface to
  41  * xdr.
  42  */
  43
  44 #include <stdio.h>
  45 #include <limits.h>
  46 #include <string.h>
  47
  48 #include <rpc/types.h>
  49 #include <rpc/xdr.h>
  50
  51 /*
  52  * constants specific to the xdr "protocol"
  53  */
  54 #define XDR_FALSE       ((long) 0)
  55 #define XDR_TRUE        ((long) 1)
  56 #define LASTUNSIGNED    ((u_int) 0-1)
  57
  58 /*
  59  * for unit alignment
  60  */
  61 static const char xdr_zero[BYTES_PER_XDR_UNIT] = {0, 0, 0, 0};
  62
  63 /*
  64  * Free a data structure using XDR
  65  * Not a filter, but a convenient utility nonetheless
  66  */
  67 void
  68 xdr_free (xdrproc_t proc, char *objp)
  69 {
  70   XDR x;
  71
  72   x.x_op = XDR_FREE;
  73   (*proc) (&x, objp);
  74 }
  75
  76 /*
  77  * XDR nothing
  78  */
  79 bool_t
  80 xdr_void (void)
  81 {
  82   return TRUE;
  83 }
  84
  85 /*
  86  * XDR integers
  87  */
  88 bool_t
  89 xdr_int (XDR *xdrs, int *ip)
  90 {
  91
  92 #if INT_MAX < LONG_MAX
  93   long l;
  94
  95   switch (xdrs->x_op)
  96     {
  97     case XDR_ENCODE:
  98       l = (long) *ip;
  99       return XDR_PUTLONG (xdrs, &l);
 100
 101     case XDR_DECODE:
 102       if (!XDR_GETLONG (xdrs, &l))
 103         {
 104           return FALSE;
 105         }
 106       *ip = (int) l;
 107     case XDR_FREE:
 108       return TRUE;
 109     }
 110   return FALSE;
 111 #elif INT_MAX == LONG_MAX
 112   return xdr_long (xdrs, (long *) ip);
 113 #elif INT_MAX == SHRT_MAX
 114   return xdr_short (xdrs, (short *) ip);
 115 #else
 116 #error unexpected integer sizes in_xdr_int()
 117 #endif
 118 }
 119
 120 /*
 121  * XDR unsigned integers
 122  */
 123 bool_t
 124 xdr_u_int (XDR *xdrs, u_int *up)
 125 {
 126 #if UINT_MAX < ULONG_MAX
 127   u_long l;
 128
 129   switch (xdrs->x_op)
 130     {
 131     case XDR_ENCODE:
 132       l = (u_long) * up;
 133       return XDR_PUTLONG (xdrs, &l);
 134
 135     case XDR_DECODE:
 136       if (!XDR_GETLONG (xdrs, &l))
 137         {
 138           return FALSE;
 139         }
 140       *up = (u_int) l;
 141     case XDR_FREE:
 142       return TRUE;
 143     }
 144   return FALSE;
 145 #elif UINT_MAX == ULONG_MAX
 146   return xdr_u_long (xdrs, (u_long *) up);
 147 #elif UINT_MAX == USHRT_MAX
 148   return xdr_short (xdrs, (short *) up);
 149 #else
 150 #error unexpected integer sizes in_xdr_u_int()
 151 #endif
 152 }
 153
 154 /*
 155  * XDR long integers
 156  * same as xdr_u_long - open coded to save a proc call!
 157  */
 158 bool_t
 159 xdr_long (XDR *xdrs, long *lp)
 160 {
 161
 162   if (xdrs->x_op == XDR_ENCODE)
 163     return XDR_PUTLONG (xdrs, lp);
 164
 165   if (xdrs->x_op == XDR_DECODE)
 166     return XDR_GETLONG (xdrs, lp);
 167
 168   if (xdrs->x_op == XDR_FREE)
 169     return TRUE;
 170
 171   return FALSE;
 172 }
 173
 174 /*
 175  * XDR unsigned long integers
 176  * same as xdr_long - open coded to save a proc call!
 177  */
 178 bool_t
 179 xdr_u_long (XDR *xdrs, u_long *ulp)
 180 {
 181   switch (xdrs->x_op)
 182     {
 183     case XDR_DECODE:
 184       return XDR_GETLONG (xdrs, (long *) ulp);
 185
 186     case XDR_ENCODE:
 187       return XDR_PUTLONG (xdrs, (long *) ulp);
 188
 189     case XDR_FREE:
 190       return TRUE;
 191     }
 192   return FALSE;
 193 }
 194
 195 /*
 196  * XDR short integers
 197  */
 198 bool_t
 199 xdr_short (xdrs, sp)
 200      XDR *xdrs;
 201      short *sp;
 202 {
 203   long l;
 204
 205   switch (xdrs->x_op)
 206     {
 207     case XDR_ENCODE:
 208       l = (long) *sp;
 209       return XDR_PUTLONG (xdrs, &l);
 210
 211     case XDR_DECODE:
 212       if (!XDR_GETLONG (xdrs, &l))
 213         {
 214           return FALSE;
 215         }
 216       *sp = (short) l;
 217       return TRUE;
 218
 219     case XDR_FREE:
 220       return TRUE;
 221     }
 222   return FALSE;
 223 }
 224
 225 /*
 226  * XDR unsigned short integers
 227  */
 228 bool_t
 229 xdr_u_short (xdrs, usp)
 230      XDR *xdrs;
 231      u_short *usp;
 232 {
 233   u_long l;
 234
 235   switch (xdrs->x_op)
 236     {
 237     case XDR_ENCODE:
 238       l = (u_long) * usp;
 239       return XDR_PUTLONG (xdrs, &l);
 240
 241     case XDR_DECODE:
 242       if (!XDR_GETLONG (xdrs, &l))
 243         {
 244           return FALSE;
 245         }
 246       *usp = (u_short) l;
 247       return TRUE;
 248
 249     case XDR_FREE:
 250       return TRUE;
 251     }
 252   return FALSE;
 253 }
 254
 255
 256 /*
 257  * XDR a char
 258  */
 259 bool_t
 260 xdr_char (xdrs, cp)
 261      XDR *xdrs;
 262      char *cp;
 263 {
 264   int i;
 265
 266   i = (*cp);
 267   if (!xdr_int (xdrs, &i))
 268     {
 269       return FALSE;
 270     }
 271   *cp = i;
 272   return TRUE;
 273 }
 274
 275 /*
 276  * XDR an unsigned char
 277  */
 278 bool_t
 279 xdr_u_char (xdrs, cp)
 280      XDR *xdrs;
 281      u_char *cp;
 282 {
 283   u_int u;
 284
 285   u = (*cp);
 286   if (!xdr_u_int (xdrs, &u))
 287     {
 288       return FALSE;
 289     }
 290   *cp = u;
 291   return TRUE;
 292 }
 293
 294 /*
 295  * XDR booleans
 296  */
 297 bool_t
 298 xdr_bool (xdrs, bp)
 299      XDR *xdrs;
 300      bool_t *bp;
 301 {
 302   long lb;
 303
 304   switch (xdrs->x_op)
 305     {
 306     case XDR_ENCODE:
 307       lb = *bp ? XDR_TRUE : XDR_FALSE;
 308       return XDR_PUTLONG (xdrs, &lb);
 309
 310     case XDR_DECODE:
 311       if (!XDR_GETLONG (xdrs, &lb))
 312         {
 313           return FALSE;
 314         }
 315       *bp = (lb == XDR_FALSE) ? FALSE : TRUE;
 316       return TRUE;
 317
 318     case XDR_FREE:
 319       return TRUE;
 320     }
 321   return FALSE;
 322 }
 323
 324 /*
 325  * XDR enumerations
 326  */
 327 bool_t
 328 xdr_enum (xdrs, ep)
 329      XDR *xdrs;
 330      enum_t *ep;
 331 {
 332   enum sizecheck
 333     {
 334       SIZEVAL
 335     };                          /* used to find the size of an enum */
 336
 337   /*
 338    * enums are treated as ints
 339    */
 340   if (sizeof (enum sizecheck) == 4)
 341     {
 342 #if INT_MAX < LONG_MAX
 343       long l;
 344
 345       switch (xdrs->x_op)
 346         {
 347         case XDR_ENCODE:
 348           l = *ep;
 349           return XDR_PUTLONG (xdrs, &l);
 350
 351         case XDR_DECODE:
 352           if (!XDR_GETLONG (xdrs, &l))
 353             {
 354               return FALSE;
 355             }
 356           *ep = l;
 357         case XDR_FREE:
 358           return TRUE;
 359
 360         }
 361       return FALSE;
 362 #else
 363       return xdr_long (xdrs, (long *) ep);
 364 #endif
 365     }
 366   else if (sizeof (enum sizecheck) == sizeof (short))
 367     {
 368       return xdr_short (xdrs, (short *) ep);
 369     }
 370   else
 371     {
 372       return FALSE;
 373     }
 374 }
 375
 376 /*
 377  * XDR opaque data
 378  * Allows the specification of a fixed size sequence of opaque bytes.
 379  * cp points to the opaque object and cnt gives the byte length.
 380  */
 381 bool_t
 382 xdr_opaque (xdrs, cp, cnt)
 383      XDR *xdrs;
 384      caddr_t cp;
 385      u_int cnt;
 386 {
 387   u_int rndup;
 388   static char crud[BYTES_PER_XDR_UNIT];
 389
 390   /*
 391    * if no data we are done
 392    */
 393   if (cnt == 0)
 394     return TRUE;
 395
 396   /*
 397    * round byte count to full xdr units
 398    */
 399   rndup = cnt % BYTES_PER_XDR_UNIT;
 400   if (rndup > 0)
 401     rndup = BYTES_PER_XDR_UNIT - rndup;
 402
 403   switch (xdrs->x_op)
 404     {
 405     case XDR_DECODE:
 406       if (!XDR_GETBYTES (xdrs, cp, cnt))
 407         {
 408           return FALSE;
 409         }
 410       if (rndup == 0)
 411         return TRUE;
 412       return XDR_GETBYTES (xdrs, (caddr_t)crud, rndup);
 413
 414     case XDR_ENCODE:
 415       if (!XDR_PUTBYTES (xdrs, cp, cnt))
 416         {
 417           return FALSE;
 418         }
 419       if (rndup == 0)
 420         return TRUE;
 421       return XDR_PUTBYTES (xdrs, xdr_zero, rndup);
 422
 423     case XDR_FREE:
 424       return TRUE;
 425     }
 426   return FALSE;
 427 }
 428
 429 /*
 430  * XDR counted bytes
 431  * *cpp is a pointer to the bytes, *sizep is the count.
 432  * If *cpp is NULL maxsize bytes are allocated
 433  */
 434 bool_t
 435 xdr_bytes (xdrs, cpp, sizep, maxsize)
 436      XDR *xdrs;
 437      char **cpp;
 438      u_int *sizep;
 439      u_int maxsize;
 440 {
 441   char *sp = *cpp;      /* sp is the actual string pointer */
 442   u_int nodesize;
 443
 444   /*
 445    * first deal with the length since xdr bytes are counted
 446    */
 447   if (!xdr_u_int (xdrs, sizep))
 448     {
 449       return FALSE;
 450     }
 451   nodesize = *sizep;
 452   if ((nodesize > maxsize) && (xdrs->x_op != XDR_FREE))
 453     {
 454       return FALSE;
 455     }
 456
 457   /*
 458    * now deal with the actual bytes
 459    */
 460   switch (xdrs->x_op)
 461     {
 462     case XDR_DECODE:
 463       if (nodesize == 0)
 464         {
 465           return TRUE;
 466         }
 467       if (sp == NULL)
 468         {
 469           *cpp = sp = (char *) mem_alloc (nodesize);
 470         }
 471       if (sp == NULL)
 472         {
 473           (void) fprintf (stderr, "xdr_bytes: out of memory\n");
 474           return FALSE;
 475         }
 476       /* fall into ... */
 477
 478     case XDR_ENCODE:
 479       return xdr_opaque (xdrs, sp, nodesize);
 480
 481     case XDR_FREE:
 482       if (sp != NULL)
 483         {
 484           mem_free (sp, nodesize);
 485           *cpp = NULL;
 486         }
 487       return TRUE;
 488     }
 489   return FALSE;
 490 }
 491
 492 /*
 493  * Implemented here due to commonality of the object.
 494  */
 495 bool_t
 496 xdr_netobj (xdrs, np)
 497      XDR *xdrs;
 498      struct netobj *np;
 499 {
 500
 501   return xdr_bytes (xdrs, &np->n_bytes, &np->n_len, MAX_NETOBJ_SZ);
 502 }
 503
 504 /*
 505  * XDR a discriminated union
 506  * Support routine for discriminated unions.
 507  * You create an array of xdrdiscrim structures, terminated with
 508  * an entry with a null procedure pointer.  The routine gets
 509  * the discriminant value and then searches the array of xdrdiscrims
 510  * looking for that value.  It calls the procedure given in the xdrdiscrim
 511  * to handle the discriminant.  If there is no specific routine a default
 512  * routine may be called.
 513  * If there is no specific or default routine an error is returned.
 514  */
 515 bool_t
 516 xdr_union (xdrs, dscmp, unp, choices, dfault)
 517      XDR *xdrs;
 518      enum_t *dscmp;             /* enum to decide which arm to work on */
 519      char *unp;                 /* the union itself */
 520      const struct xdr_discrim *choices; /* [value, xdr proc] for each arm */
 521      xdrproc_t dfault;          /* default xdr routine */
 522 {
 523   enum_t dscm;
 524
 525   /*
 526    * we deal with the discriminator;  it's an enum
 527    */
 528   if (!xdr_enum (xdrs, dscmp))
 529     {
 530       return FALSE;
 531     }
 532   dscm = *dscmp;
 533
 534   /*
 535    * search choices for a value that matches the discriminator.
 536    * if we find one, execute the xdr routine for that value.
 537    */
 538   for (; choices->proc != NULL_xdrproc_t; choices++)
 539     {
 540       if (choices->value == dscm)
 541         return (*(choices->proc)) (xdrs, unp, LASTUNSIGNED);
 542     }
 543
 544   /*
 545    * no match - execute the default xdr routine if there is one
 546    */
 547   return ((dfault == NULL_xdrproc_t) ? FALSE :
 548           (*dfault) (xdrs, unp, LASTUNSIGNED));
 549 }
 550
 551
 552 /*
 553  * Non-portable xdr primitives.
 554  * Care should be taken when moving these routines to new architectures.
 555  */
 556
 557
 558 /*
 559  * XDR null terminated ASCII strings
 560  * xdr_string deals with "C strings" - arrays of bytes that are
 561  * terminated by a NULL character.  The parameter cpp references a
 562  * pointer to storage; If the pointer is null, then the necessary
 563  * storage is allocated.  The last parameter is the max allowed length
 564  * of the string as specified by a protocol.
 565  */
 566 bool_t
 567 xdr_string (xdrs, cpp, maxsize)
 568      XDR *xdrs;
 569      char **cpp;
 570      u_int maxsize;
 571 {
 572   char *sp = *cpp;      /* sp is the actual string pointer */
 573   u_int size;
 574   u_int nodesize;
 575
 576   /*
 577    * first deal with the length since xdr strings are counted-strings
 578    */
 579   switch (xdrs->x_op)
 580     {
 581     case XDR_FREE:
 582       if (sp == NULL)
 583         {
 584           return TRUE;          /* already free */
 585         }
 586       /* fall through... */
 587     case XDR_ENCODE:
 588       if (sp == NULL)
 589         return FALSE;
 590       size = strlen (sp);
 591       break;
 592     case XDR_DECODE:
 593       break;
 594     }
 595   if (!xdr_u_int (xdrs, &size))
 596     {
 597       return FALSE;
 598     }
 599   if (size > maxsize)
 600     {
 601       return FALSE;
 602     }
 603   nodesize = size + 1;
 604
 605   /*
 606    * now deal with the actual bytes
 607    */
 608   switch (xdrs->x_op)
 609     {
 610     case XDR_DECODE:
 611       if (nodesize == 0)
 612         {
 613           return TRUE;
 614         }
 615       if (sp == NULL)
 616         *cpp = sp = (char *) mem_alloc (nodesize);
 617       if (sp == NULL)
 618         {
 619           (void) fprintf (stderr, "xdr_string: out of memory\n");
 620           return FALSE;
 621         }
 622       sp[size] = 0;
 623       /* fall into ... */
 624
 625     case XDR_ENCODE:
 626       return xdr_opaque (xdrs, sp, size);
 627
 628     case XDR_FREE:
 629       mem_free (sp, nodesize);
 630       *cpp = NULL;
 631       return TRUE;
 632     }
 633   return FALSE;
 634 }
 635
 636 /*
 637  * Wrapper for xdr_string that can be called directly from
 638  * routines like clnt_call
 639  */
 640 bool_t
 641 xdr_wrapstring (xdrs, cpp)
 642      XDR *xdrs;
 643      char **cpp;
 644 {
 645   if (xdr_string (xdrs, cpp, LASTUNSIGNED))
 646     {
 647       return TRUE;
 648     }
 649   return FALSE;
 650 }