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