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