(root)/
glibc-2.38/
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