1  /* Copyright (C) 1996-2023 Free Software Foundation, Inc.
       2     This file is part of the GNU C Library.
       3  
       4     The GNU C Library is free software; you can redistribute it and/or
       5     modify it under the terms of the GNU Lesser General Public
       6     License as published by the Free Software Foundation; either
       7     version 2.1 of the License, or (at your option) any later version.
       8  
       9     The GNU C Library is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      12     Lesser General Public License for more details.
      13  
      14     You should have received a copy of the GNU Lesser General Public
      15     License along with the GNU C Library; if not, see
      16     <https://www.gnu.org/licenses/>.  */
      17  
      18  #include <assert.h>
      19  #include <dlfcn.h>
      20  #include <errno.h>
      21  #include <stdlib.h>
      22  #include <gconv.h>
      23  #include <wchar.h>
      24  #include <wcsmbsload.h>
      25  
      26  #include <pointer_guard.h>
      27  
      28  #ifndef EILSEQ
      29  # define EILSEQ EINVAL
      30  #endif
      31  
      32  
      33  /* This is the private state used if PS is NULL.  */
      34  static mbstate_t state;
      35  
      36  size_t
      37  __wcsrtombs (char *dst, const wchar_t **src, size_t len, mbstate_t *ps)
      38  {
      39    struct __gconv_step_data data;
      40    int status;
      41    size_t result;
      42    struct __gconv_step *tomb;
      43    const struct gconv_fcts *fcts;
      44  
      45    /* Tell where we want the result.  */
      46    data.__invocation_counter = 0;
      47    data.__internal_use = 1;
      48    data.__flags = __GCONV_IS_LAST;
      49    data.__statep = ps ?: &state;
      50  
      51    /* Get the conversion functions.  */
      52    fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
      53  
      54    /* Get the structure with the function pointers.  */
      55    tomb = fcts->tomb;
      56    __gconv_fct fct = tomb->__fct;
      57    if (tomb->__shlib_handle != NULL)
      58      PTR_DEMANGLE (fct);
      59  
      60    /* We have to handle DST == NULL special.  */
      61    if (dst == NULL)
      62      {
      63        mbstate_t temp_state;
      64        unsigned char buf[256];		/* Just an arbitrary value.  */
      65        const wchar_t *srcend = *src + __wcslen (*src) + 1;
      66        const unsigned char *inbuf = (const unsigned char *) *src;
      67        size_t dummy;
      68  
      69        temp_state = *data.__statep;
      70        data.__statep = &temp_state;
      71  
      72        result = 0;
      73        data.__outbufend = buf + sizeof (buf);
      74  
      75        do
      76  	{
      77  	  data.__outbuf = buf;
      78  
      79  	  status = DL_CALL_FCT (fct, (tomb, &data, &inbuf,
      80  				      (const unsigned char *) srcend, NULL,
      81  				      &dummy, 0, 1));
      82  
      83  	  /* Count the number of bytes.  */
      84  	  result += data.__outbuf - buf;
      85  	}
      86        while (status == __GCONV_FULL_OUTPUT);
      87  
      88        if (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
      89  	{
      90  	  /* There better should be a NUL byte at the end.  */
      91  	  assert (data.__outbuf[-1] == '\0');
      92  	  /* Don't count the NUL character in.  */
      93  	  --result;
      94  	}
      95      }
      96    else
      97      {
      98        /* This code is based on the safe assumption that all internal
      99  	 multi-byte encodings use the NUL byte only to mark the end
     100  	 of the string.  */
     101        const wchar_t *srcend = *src + __wcsnlen (*src, len) + 1;
     102        size_t dummy;
     103  
     104        data.__outbuf = (unsigned char *) dst;
     105        data.__outbufend = (unsigned char *) dst + len;
     106  
     107        status = DL_CALL_FCT (fct, (tomb, &data, (const unsigned char **) src,
     108  				  (const unsigned char *) srcend, NULL,
     109  				  &dummy, 0, 1));
     110  
     111        /* Count the number of bytes.  */
     112        result = data.__outbuf - (unsigned char *) dst;
     113  
     114        /* We have to determine whether the last character converted
     115  	 is the NUL character.  */
     116        if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
     117  	  && data.__outbuf[-1] == '\0')
     118  	{
     119  	  assert (data.__outbuf != (unsigned char *) dst);
     120  	  assert (__mbsinit (data.__statep));
     121  	  *src = NULL;
     122  	  --result;
     123  	}
     124      }
     125  
     126    /* There must not be any problems with the conversion but illegal input
     127       characters.  */
     128    assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
     129  	  || status == __GCONV_ILLEGAL_INPUT
     130  	  || status == __GCONV_INCOMPLETE_INPUT
     131  	  || status == __GCONV_FULL_OUTPUT);
     132  
     133    if (status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
     134        && status != __GCONV_EMPTY_INPUT)
     135      {
     136        result = (size_t) -1;
     137        __set_errno (EILSEQ);
     138      }
     139  
     140    return result;
     141  }
     142  weak_alias (__wcsrtombs, wcsrtombs)