sunrpc/xdr.c

   1 /*
   2  * xdr.c, Generic XDR routines implementation.
   3  *
   4  * Copyright (c) 2010, Oracle America, Inc.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions are
   8  * met:
   9  *
  10  *     * Redistributions of source code must retain the above copyright
  11  *       notice, this list of conditions and the following disclaimer.
  12  *     * Redistributions in binary form must reproduce the above
  13  *       copyright notice, this list of conditions and the following
  14  *       disclaimer in the documentation and/or other materials
  15  *       provided with the distribution.
  16  *     * Neither the name of the "Oracle America, Inc." nor the names of its
  17  *       contributors may be used to endorse or promote products derived
  18  *       from this software without specific prior written permission.
  19  *
  20  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  21  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  22  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  23  *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  24  *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
  25  *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
  27  *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  28  *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  29  *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  30  *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  *
  33  * These are the "generic" xdr routines used to serialize and de-serialize
  34  * most common data items.  See xdr.h for more info on the interface to
  35  * xdr.
  36  */
  37
  38 #include <stdio.h>
  39 #include <limits.h>
  40 #include <string.h>
  41 #include <libintl.h>
  42 #include <wchar.h>
  43
  44 #include <rpc/types.h>
  45 #include <rpc/xdr.h>
  46
  47
  48 /*
  49  * constants specific to the xdr "protocol"
  50  */
  51 #define XDR_FALSE       ((long) 0)
  52 #define XDR_TRUE        ((long) 1)
  53 #define LASTUNSIGNED    ((u_int) 0-1)
  54
  55 /*
  56  * for unit alignment
  57  */
  58 static const char xdr_zero[BYTES_PER_XDR_UNIT] = {0, 0, 0, 0};
  59
  60 /*
  61  * Free a data structure using XDR
  62  * Not a filter, but a convenient utility nonetheless
  63  */
  64 void
  65 xdr_free (xdrproc_t proc, char *objp)
  66 {
  67   XDR x;
  68
  69   x.x_op = XDR_FREE;
  70   (*proc) (&x, objp);
  71 }
  72 #ifdef EXPORT_RPC_SYMBOLS
  73 libc_hidden_def (xdr_free)
  74 #else
  75 libc_hidden_nolink_sunrpc (xdr_free, GLIBC_2_0)
  76 #endif
  77
  78 /*
  79  * XDR nothing
  80  */
  81 bool_t
  82 xdr_void (void)
  83 {
  84   return TRUE;
  85 }
  86 #ifdef EXPORT_RPC_SYMBOLS
  87 libc_hidden_def (xdr_void)
  88 #else
  89 libc_hidden_nolink_sunrpc (xdr_void, GLIBC_2_0)
  90 #endif
  91
  92 /*
  93  * XDR integers
  94  */
  95 bool_t
  96 xdr_int (XDR *xdrs, int *ip)
  97 {
  98
  99 #if INT_MAX < LONG_MAX
 100   long l;
 101
 102   switch (xdrs->x_op)
 103     {
 104     case XDR_ENCODE:
 105       l = (long) *ip;
 106       return XDR_PUTLONG (xdrs, &l);
 107
 108     case XDR_DECODE:
 109       if (!XDR_GETLONG (xdrs, &l))
 110         {
 111           return FALSE;
 112         }
 113       *ip = (int) l;
 114     case XDR_FREE:
 115       return TRUE;
 116     }
 117   return FALSE;
 118 #elif INT_MAX == LONG_MAX
 119   return xdr_long (xdrs, (long *) ip);
 120 #elif INT_MAX == SHRT_MAX
 121   return xdr_short (xdrs, (short *) ip);
 122 #else
 123 #error unexpected integer sizes in_xdr_int()
 124 #endif
 125 }
 126 #ifdef EXPORT_RPC_SYMBOLS
 127 libc_hidden_def (xdr_int)
 128 #else
 129 libc_hidden_nolink_sunrpc (xdr_int, GLIBC_2_0)
 130 #endif
 131
 132 /*
 133  * XDR unsigned integers
 134  */
 135 bool_t
 136 xdr_u_int (XDR *xdrs, u_int *up)
 137 {
 138 #if UINT_MAX < ULONG_MAX
 139   long l;
 140
 141   switch (xdrs->x_op)
 142     {
 143     case XDR_ENCODE:
 144       l = (u_long) * up;
 145       return XDR_PUTLONG (xdrs, &l);
 146
 147     case XDR_DECODE:
 148       if (!XDR_GETLONG (xdrs, &l))
 149         {
 150           return FALSE;
 151         }
 152       *up = (u_int) (u_long) l;
 153     case XDR_FREE:
 154       return TRUE;
 155     }
 156   return FALSE;
 157 #elif UINT_MAX == ULONG_MAX
 158   return xdr_u_long (xdrs, (u_long *) up);
 159 #elif UINT_MAX == USHRT_MAX
 160   return xdr_short (xdrs, (short *) up);
 161 #else
 162 #error unexpected integer sizes in_xdr_u_int()
 163 #endif
 164 }
 165 #ifdef EXPORT_RPC_SYMBOLS
 166 libc_hidden_def (xdr_u_int)
 167 #else
 168 libc_hidden_nolink_sunrpc (xdr_u_int, GLIBC_2_0)
 169 #endif
 170
 171 /*
 172  * XDR long integers
 173  * The definition of xdr_long() is kept for backward
 174  * compatibility. Instead xdr_int() should be used.
 175  */
 176 bool_t
 177 xdr_long (XDR *xdrs, long *lp)
 178 {
 179
 180   if (xdrs->x_op == XDR_ENCODE
 181       && (sizeof (int32_t) == sizeof (long)
 182           || (int32_t) *lp == *lp))
 183     return XDR_PUTLONG (xdrs, lp);
 184
 185   if (xdrs->x_op == XDR_DECODE)
 186     return XDR_GETLONG (xdrs, lp);
 187
 188   if (xdrs->x_op == XDR_FREE)
 189     return TRUE;
 190
 191   return FALSE;
 192 }
 193 #ifdef EXPORT_RPC_SYMBOLS
 194 libc_hidden_def (xdr_long)
 195 #else
 196 libc_hidden_nolink_sunrpc (xdr_long, GLIBC_2_0)
 197 #endif
 198
 199 /*
 200  * XDR unsigned long integers
 201  * The definition of xdr_u_long() is kept for backward
 202  * compatibility. Instead xdr_u_int() should be used.
 203  */
 204 bool_t
 205 xdr_u_long (XDR *xdrs, u_long *ulp)
 206 {
 207   switch (xdrs->x_op)
 208     {
 209     case XDR_DECODE:
 210       {
 211         long int tmp;
 212
 213         if (XDR_GETLONG (xdrs, &tmp) == FALSE)
 214           return FALSE;
 215
 216         *ulp = (uint32_t) tmp;
 217         return TRUE;
 218       }
 219
 220     case XDR_ENCODE:
 221       if (sizeof (uint32_t) != sizeof (u_long)
 222           && (uint32_t) *ulp != *ulp)
 223         return FALSE;
 224
 225       return XDR_PUTLONG (xdrs, (long *) ulp);
 226
 227     case XDR_FREE:
 228       return TRUE;
 229     }
 230   return FALSE;
 231 }
 232 #ifdef EXPORT_RPC_SYMBOLS
 233 libc_hidden_def (xdr_u_long)
 234 #else
 235 libc_hidden_nolink_sunrpc (xdr_u_long, GLIBC_2_0)
 236 #endif
 237
 238 /*
 239  * XDR hyper integers
 240  * same as xdr_u_hyper - open coded to save a proc call!
 241  */
 242 bool_t
 243 xdr_hyper (XDR *xdrs, quad_t *llp)
 244 {
 245   long int t1, t2;
 246
 247   if (xdrs->x_op == XDR_ENCODE)
 248     {
 249       t1 = (long) ((*llp) >> 32);
 250       t2 = (long) (*llp);
 251       return (XDR_PUTLONG(xdrs, &t1) && XDR_PUTLONG(xdrs, &t2));
 252     }
 253
 254   if (xdrs->x_op == XDR_DECODE)
 255     {
 256       if (!XDR_GETLONG(xdrs, &t1) || !XDR_GETLONG(xdrs, &t2))
 257         return FALSE;
 258       *llp = ((quad_t) t1) << 32;
 259       *llp |= (uint32_t) t2;
 260       return TRUE;
 261     }
 262
 263   if (xdrs->x_op == XDR_FREE)
 264     return TRUE;
 265
 266   return FALSE;
 267 }
 268 #ifdef EXPORT_RPC_SYMBOLS
 269 libc_hidden_def (xdr_hyper)
 270 #else
 271 libc_hidden_nolink_sunrpc (xdr_hyper, GLIBC_2_1_1)
 272 #endif
 273
 274 /*
 275  * XDR hyper integers
 276  * same as xdr_hyper - open coded to save a proc call!
 277  */
 278 bool_t
 279 xdr_u_hyper (XDR *xdrs, u_quad_t *ullp)
 280 {
 281   long int t1, t2;
 282
 283   if (xdrs->x_op == XDR_ENCODE)
 284     {
 285       t1 = (unsigned long) ((*ullp) >> 32);
 286       t2 = (unsigned long) (*ullp);
 287       return (XDR_PUTLONG(xdrs, &t1) && XDR_PUTLONG(xdrs, &t2));
 288     }
 289
 290   if (xdrs->x_op == XDR_DECODE)
 291     {
 292       if (!XDR_GETLONG(xdrs, &t1) || !XDR_GETLONG(xdrs, &t2))
 293         return FALSE;
 294       *ullp = ((u_quad_t) t1) << 32;
 295       *ullp |= (uint32_t) t2;
 296       return TRUE;
 297     }
 298
 299   if (xdrs->x_op == XDR_FREE)
 300     return TRUE;
 301
 302   return FALSE;
 303 }
 304 #ifdef EXPORT_RPC_SYMBOLS
 305 libc_hidden_def (xdr_u_hyper)
 306 #else
 307 libc_hidden_nolink_sunrpc (xdr_u_hyper, GLIBC_2_1_1)
 308 #endif
 309
 310 bool_t
 311 xdr_longlong_t (XDR *xdrs, quad_t *llp)
 312 {
 313   return xdr_hyper (xdrs, llp);
 314 }
 315 #ifdef EXPORT_RPC_SYMBOLS
 316 libc_hidden_def (xdr_longlong_t)
 317 #else
 318 libc_hidden_nolink_sunrpc (xdr_longlong_t, GLIBC_2_1_1)
 319 #endif
 320
 321 bool_t
 322 xdr_u_longlong_t (XDR *xdrs, u_quad_t *ullp)
 323 {
 324   return xdr_u_hyper (xdrs, ullp);
 325 }
 326 #ifdef EXPORT_RPC_SYMBOLS
 327 libc_hidden_def (xdr_u_longlong_t)
 328 #else
 329 libc_hidden_nolink_sunrpc (xdr_u_longlong_t, GLIBC_2_1_1)
 330 #endif
 331
 332 /*
 333  * XDR short integers
 334  */
 335 bool_t
 336 xdr_short (XDR *xdrs, short *sp)
 337 {
 338   long l;
 339
 340   switch (xdrs->x_op)
 341     {
 342     case XDR_ENCODE:
 343       l = (long) *sp;
 344       return XDR_PUTLONG (xdrs, &l);
 345
 346     case XDR_DECODE:
 347       if (!XDR_GETLONG (xdrs, &l))
 348         {
 349           return FALSE;
 350         }
 351       *sp = (short) l;
 352       return TRUE;
 353
 354     case XDR_FREE:
 355       return TRUE;
 356     }
 357   return FALSE;
 358 }
 359 #ifdef EXPORT_RPC_SYMBOLS
 360 libc_hidden_def (xdr_short)
 361 #else
 362 libc_hidden_nolink_sunrpc (xdr_short, GLIBC_2_0)
 363 #endif
 364
 365 /*
 366  * XDR unsigned short integers
 367  */
 368 bool_t
 369 xdr_u_short (XDR *xdrs, u_short *usp)
 370 {
 371   long l;
 372
 373   switch (xdrs->x_op)
 374     {
 375     case XDR_ENCODE:
 376       l = (u_long) * usp;
 377       return XDR_PUTLONG (xdrs, &l);
 378
 379     case XDR_DECODE:
 380       if (!XDR_GETLONG (xdrs, &l))
 381         {
 382           return FALSE;
 383         }
 384       *usp = (u_short) (u_long) l;
 385       return TRUE;
 386
 387     case XDR_FREE:
 388       return TRUE;
 389     }
 390   return FALSE;
 391 }
 392 #ifdef EXPORT_RPC_SYMBOLS
 393 libc_hidden_def (xdr_u_short)
 394 #else
 395 libc_hidden_nolink_sunrpc (xdr_u_short, GLIBC_2_0)
 396 #endif
 397
 398
 399 /*
 400  * XDR a char
 401  */
 402 bool_t
 403 xdr_char (XDR *xdrs, char *cp)
 404 {
 405   int i;
 406
 407   i = (*cp);
 408   if (!xdr_int (xdrs, &i))
 409     {
 410       return FALSE;
 411     }
 412   *cp = i;
 413   return TRUE;
 414 }
 415 #ifdef EXPORT_RPC_SYMBOLS
 416 libc_hidden_def (xdr_char)
 417 #else
 418 libc_hidden_nolink_sunrpc (xdr_char, GLIBC_2_0)
 419 #endif
 420
 421 /*
 422  * XDR an unsigned char
 423  */
 424 bool_t
 425 xdr_u_char (XDR *xdrs, u_char *cp)
 426 {
 427   u_int u;
 428
 429   u = (*cp);
 430   if (!xdr_u_int (xdrs, &u))
 431     {
 432       return FALSE;
 433     }
 434   *cp = u;
 435   return TRUE;
 436 }
 437 #ifdef EXPORT_RPC_SYMBOLS
 438 libc_hidden_def (xdr_u_char)
 439 #else
 440 libc_hidden_nolink_sunrpc (xdr_u_char, GLIBC_2_0)
 441 #endif
 442
 443 /*
 444  * XDR booleans
 445  */
 446 bool_t
 447 xdr_bool (XDR *xdrs, bool_t *bp)
 448 {
 449   long lb;
 450
 451   switch (xdrs->x_op)
 452     {
 453     case XDR_ENCODE:
 454       lb = *bp ? XDR_TRUE : XDR_FALSE;
 455       return XDR_PUTLONG (xdrs, &lb);
 456
 457     case XDR_DECODE:
 458       if (!XDR_GETLONG (xdrs, &lb))
 459         {
 460           return FALSE;
 461         }
 462       *bp = (lb == XDR_FALSE) ? FALSE : TRUE;
 463       return TRUE;
 464
 465     case XDR_FREE:
 466       return TRUE;
 467     }
 468   return FALSE;
 469 }
 470 #ifdef EXPORT_RPC_SYMBOLS
 471 libc_hidden_def (xdr_bool)
 472 #else
 473 libc_hidden_nolink_sunrpc (xdr_bool, GLIBC_2_0)
 474 #endif
 475
 476 /*
 477  * XDR enumerations
 478  */
 479 bool_t
 480 xdr_enum (XDR *xdrs, enum_t *ep)
 481 {
 482   enum sizecheck
 483     {
 484       SIZEVAL
 485     };                          /* used to find the size of an enum */
 486
 487   /*
 488    * enums are treated as ints
 489    */
 490   if (sizeof (enum sizecheck) == 4)
 491     {
 492 #if INT_MAX < LONG_MAX
 493       long l;
 494
 495       switch (xdrs->x_op)
 496         {
 497         case XDR_ENCODE:
 498           l = *ep;
 499           return XDR_PUTLONG (xdrs, &l);
 500
 501         case XDR_DECODE:
 502           if (!XDR_GETLONG (xdrs, &l))
 503             {
 504               return FALSE;
 505             }
 506           *ep = l;
 507         case XDR_FREE:
 508           return TRUE;
 509
 510         }
 511       return FALSE;
 512 #else
 513       return xdr_long (xdrs, (long *) ep);
 514 #endif
 515     }
 516   else if (sizeof (enum sizecheck) == sizeof (short))
 517     {
 518       return xdr_short (xdrs, (short *) ep);
 519     }
 520   else
 521     {
 522       return FALSE;
 523     }
 524 }
 525 #ifdef EXPORT_RPC_SYMBOLS
 526 libc_hidden_def (xdr_enum)
 527 #else
 528 libc_hidden_nolink_sunrpc (xdr_enum, GLIBC_2_0)
 529 #endif
 530
 531 /*
 532  * XDR opaque data
 533  * Allows the specification of a fixed size sequence of opaque bytes.
 534  * cp points to the opaque object and cnt gives the byte length.
 535  */
 536 bool_t
 537 xdr_opaque (XDR *xdrs, caddr_t cp, u_int cnt)
 538 {
 539   u_int rndup;
 540   static char crud[BYTES_PER_XDR_UNIT];
 541
 542   /*
 543    * if no data we are done
 544    */
 545   if (cnt == 0)
 546     return TRUE;
 547
 548   /*
 549    * round byte count to full xdr units
 550    */
 551   rndup = cnt % BYTES_PER_XDR_UNIT;
 552   if (rndup > 0)
 553     rndup = BYTES_PER_XDR_UNIT - rndup;
 554
 555   switch (xdrs->x_op)
 556     {
 557     case XDR_DECODE:
 558       if (!XDR_GETBYTES (xdrs, cp, cnt))
 559         {
 560           return FALSE;
 561         }
 562       if (rndup == 0)
 563         return TRUE;
 564       return XDR_GETBYTES (xdrs, (caddr_t)crud, rndup);
 565
 566     case XDR_ENCODE:
 567       if (!XDR_PUTBYTES (xdrs, cp, cnt))
 568         {
 569           return FALSE;
 570         }
 571       if (rndup == 0)
 572         return TRUE;
 573       return XDR_PUTBYTES (xdrs, xdr_zero, rndup);
 574
 575     case XDR_FREE:
 576       return TRUE;
 577     }
 578   return FALSE;
 579 }
 580 #ifdef EXPORT_RPC_SYMBOLS
 581 libc_hidden_def (xdr_opaque)
 582 #else
 583 libc_hidden_nolink_sunrpc (xdr_opaque, GLIBC_2_0)
 584 #endif
 585
 586 /*
 587  * XDR counted bytes
 588  * *cpp is a pointer to the bytes, *sizep is the count.
 589  * If *cpp is NULL maxsize bytes are allocated
 590  */
 591 bool_t
 592 xdr_bytes (xdrs, cpp, sizep, maxsize)
 593      XDR *xdrs;
 594      char **cpp;
 595      u_int *sizep;
 596      u_int maxsize;
 597 {
 598   char *sp = *cpp;      /* sp is the actual string pointer */
 599   u_int nodesize;
 600
 601   /*
 602    * first deal with the length since xdr bytes are counted
 603    */
 604   if (!xdr_u_int (xdrs, sizep))
 605     {
 606       return FALSE;
 607     }
 608   nodesize = *sizep;
 609   if ((nodesize > maxsize) && (xdrs->x_op != XDR_FREE))
 610     {
 611       return FALSE;
 612     }
 613
 614   /*
 615    * now deal with the actual bytes
 616    */
 617   switch (xdrs->x_op)
 618     {
 619     case XDR_DECODE:
 620       if (nodesize == 0)
 621         {
 622           return TRUE;
 623         }
 624       if (sp == NULL)
 625         {
 626           *cpp = sp = (char *) mem_alloc (nodesize);
 627         }
 628       if (sp == NULL)
 629         {
 630           (void) __fxprintf (NULL, "%s: %s", __func__, _("out of memory\n"));
 631           return FALSE;
 632         }
 633       /* fall into ... */
 634
 635     case XDR_ENCODE:
 636       return xdr_opaque (xdrs, sp, nodesize);
 637
 638     case XDR_FREE:
 639       if (sp != NULL)
 640         {
 641           mem_free (sp, nodesize);
 642           *cpp = NULL;
 643         }
 644       return TRUE;
 645     }
 646   return FALSE;
 647 }
 648 #ifdef EXPORT_RPC_SYMBOLS
 649 libc_hidden_def (xdr_bytes)
 650 #else
 651 libc_hidden_nolink_sunrpc (xdr_bytes, GLIBC_2_0)
 652 #endif
 653
 654 /*
 655  * Implemented here due to commonality of the object.
 656  */
 657 bool_t
 658 xdr_netobj (xdrs, np)
 659      XDR *xdrs;
 660      struct netobj *np;
 661 {
 662
 663   return xdr_bytes (xdrs, &np->n_bytes, &np->n_len, MAX_NETOBJ_SZ);
 664 }
 665 #ifdef EXPORT_RPC_SYMBOLS
 666 libc_hidden_def (xdr_netobj)
 667 #else
 668 libc_hidden_nolink_sunrpc (xdr_netobj, GLIBC_2_0)
 669 #endif
 670
 671 /*
 672  * XDR a discriminated union
 673  * Support routine for discriminated unions.
 674  * You create an array of xdrdiscrim structures, terminated with
 675  * an entry with a null procedure pointer.  The routine gets
 676  * the discriminant value and then searches the array of xdrdiscrims
 677  * looking for that value.  It calls the procedure given in the xdrdiscrim
 678  * to handle the discriminant.  If there is no specific routine a default
 679  * routine may be called.
 680  * If there is no specific or default routine an error is returned.
 681  */
 682 bool_t
 683 xdr_union (xdrs, dscmp, unp, choices, dfault)
 684      XDR *xdrs;
 685      enum_t *dscmp;             /* enum to decide which arm to work on */
 686      char *unp;                 /* the union itself */
 687      const struct xdr_discrim *choices; /* [value, xdr proc] for each arm */
 688      xdrproc_t dfault;          /* default xdr routine */
 689 {
 690   enum_t dscm;
 691
 692   /*
 693    * we deal with the discriminator;  it's an enum
 694    */
 695   if (!xdr_enum (xdrs, dscmp))
 696     {
 697       return FALSE;
 698     }
 699   dscm = *dscmp;
 700
 701   /*
 702    * search choices for a value that matches the discriminator.
 703    * if we find one, execute the xdr routine for that value.
 704    */
 705   for (; choices->proc != NULL_xdrproc_t; choices++)
 706     {
 707       if (choices->value == dscm)
 708         return (*(choices->proc)) (xdrs, unp, LASTUNSIGNED);
 709     }
 710
 711   /*
 712    * no match - execute the default xdr routine if there is one
 713    */
 714   return ((dfault == NULL_xdrproc_t) ? FALSE :
 715           (*dfault) (xdrs, unp, LASTUNSIGNED));
 716 }
 717 libc_hidden_nolink_sunrpc (xdr_union, GLIBC_2_0)
 718
 719
 720 /*
 721  * Non-portable xdr primitives.
 722  * Care should be taken when moving these routines to new architectures.
 723  */
 724
 725
 726 /*
 727  * XDR null terminated ASCII strings
 728  * xdr_string deals with "C strings" - arrays of bytes that are
 729  * terminated by a NULL character.  The parameter cpp references a
 730  * pointer to storage; If the pointer is null, then the necessary
 731  * storage is allocated.  The last parameter is the max allowed length
 732  * of the string as specified by a protocol.
 733  */
 734 bool_t
 735 xdr_string (xdrs, cpp, maxsize)
 736      XDR *xdrs;
 737      char **cpp;
 738      u_int maxsize;
 739 {
 740   char *sp = *cpp;      /* sp is the actual string pointer */
 741   u_int size;
 742   u_int nodesize;
 743
 744   /*
 745    * first deal with the length since xdr strings are counted-strings
 746    */
 747   switch (xdrs->x_op)
 748     {
 749     case XDR_FREE:
 750       if (sp == NULL)
 751         {
 752           return TRUE;          /* already free */
 753         }
 754       /* fall through... */
 755     case XDR_ENCODE:
 756       if (sp == NULL)
 757         return FALSE;
 758       size = strlen (sp);
 759       break;
 760     case XDR_DECODE:
 761       break;
 762     }
 763   if (!xdr_u_int (xdrs, &size))
 764     {
 765       return FALSE;
 766     }
 767   if (size > maxsize)
 768     {
 769       return FALSE;
 770     }
 771   nodesize = size + 1;
 772   if (nodesize == 0)
 773     {
 774       /* This means an overflow.  It a bug in the caller which
 775          provided a too large maxsize but nevertheless catch it
 776          here.  */
 777       return FALSE;
 778     }
 779
 780   /*
 781    * now deal with the actual bytes
 782    */
 783   switch (xdrs->x_op)
 784     {
 785     case XDR_DECODE:
 786       if (sp == NULL)
 787         *cpp = sp = (char *) mem_alloc (nodesize);
 788       if (sp == NULL)
 789         {
 790           (void) __fxprintf (NULL, "%s: %s", __func__, _("out of memory\n"));
 791           return FALSE;
 792         }
 793       sp[size] = 0;
 794       /* fall into ... */
 795
 796     case XDR_ENCODE:
 797       return xdr_opaque (xdrs, sp, size);
 798
 799     case XDR_FREE:
 800       mem_free (sp, nodesize);
 801       *cpp = NULL;
 802       return TRUE;
 803     }
 804   return FALSE;
 805 }
 806 #ifdef EXPORT_RPC_SYMBOLS
 807 libc_hidden_def (xdr_string)
 808 #else
 809 libc_hidden_nolink_sunrpc (xdr_string, GLIBC_2_0)
 810 #endif
 811
 812 /*
 813  * Wrapper for xdr_string that can be called directly from
 814  * routines like clnt_call
 815  */
 816 bool_t
 817 xdr_wrapstring (xdrs, cpp)
 818      XDR *xdrs;
 819      char **cpp;
 820 {
 821   if (xdr_string (xdrs, cpp, LASTUNSIGNED))
 822     {
 823       return TRUE;
 824     }
 825   return FALSE;
 826 }
 827 #ifdef EXPORT_RPC_SYMBOLS
 828 libc_hidden_def (xdr_wrapstring)
 829 #else
 830 libc_hidden_nolink_sunrpc (xdr_wrapstring, GLIBC_2_0)
 831 #endif