iconv/gconv_trans.c

   1 /* Transliteration using the locale's data.
   2    Copyright (C) 2000-2014 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 2000.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <assert.h>
  21 #include <dlfcn.h>
  22 #include <search.h>
  23 #include <stdint.h>
  24 #include <string.h>
  25 #include <stdlib.h>
  26
  27 #include <bits/libc-lock.h>
  28 #include "gconv_int.h"
  29 #include "../locale/localeinfo.h"
  30
  31
  32 int
  33 __gconv_transliterate (struct __gconv_step *step,
  34                        struct __gconv_step_data *step_data,
  35                        void *trans_data __attribute__ ((unused)),
  36                        const unsigned char *inbufstart,
  37                        const unsigned char **inbufp,
  38                        const unsigned char *inbufend,
  39                        unsigned char **outbufstart, size_t *irreversible)
  40 {
  41   /* Find out about the locale's transliteration.  */
  42   uint_fast32_t size;
  43   const uint32_t *from_idx;
  44   const uint32_t *from_tbl;
  45   const uint32_t *to_idx;
  46   const uint32_t *to_tbl;
  47   const uint32_t *winbuf;
  48   const uint32_t *winbufend;
  49   uint_fast32_t low;
  50   uint_fast32_t high;
  51
  52   /* The input buffer.  There are actually 4-byte values.  */
  53   winbuf = (const uint32_t *) *inbufp;
  54   winbufend = (const uint32_t *) inbufend;
  55
  56   __gconv_fct fct = step->__fct;
  57 #ifdef PTR_DEMANGLE
  58   if (step->__shlib_handle != NULL)
  59     PTR_DEMANGLE (fct);
  60 #endif
  61
  62   /* If there is no transliteration information in the locale don't do
  63      anything and return the error.  */
  64   size = _NL_CURRENT_WORD (LC_CTYPE, _NL_CTYPE_TRANSLIT_TAB_SIZE);
  65   if (size == 0)
  66     goto no_rules;
  67
  68   /* Get the rest of the values.  */
  69   from_idx =
  70     (const uint32_t *) _NL_CURRENT (LC_CTYPE, _NL_CTYPE_TRANSLIT_FROM_IDX);
  71   from_tbl =
  72     (const uint32_t *) _NL_CURRENT (LC_CTYPE, _NL_CTYPE_TRANSLIT_FROM_TBL);
  73   to_idx =
  74     (const uint32_t *) _NL_CURRENT (LC_CTYPE, _NL_CTYPE_TRANSLIT_TO_IDX);
  75   to_tbl =
  76     (const uint32_t *) _NL_CURRENT (LC_CTYPE, _NL_CTYPE_TRANSLIT_TO_TBL);
  77
  78   /* Test whether there is enough input.  */
  79   if (winbuf + 1 > winbufend)
  80     return (winbuf == winbufend
  81             ? __GCONV_EMPTY_INPUT : __GCONV_INCOMPLETE_INPUT);
  82
  83   /* The array starting at FROM_IDX contains indeces to the string table
  84      in FROM_TBL.  The indeces are sorted wrt to the strings.  I.e., we
  85      are doing binary search.  */
  86   low = 0;
  87   high = size;
  88   while (low < high)
  89     {
  90       uint_fast32_t med = (low + high) / 2;
  91       uint32_t idx;
  92       int cnt;
  93
  94       /* Compare the string at this index with the string at the current
  95          position in the input buffer.  */
  96       idx = from_idx[med];
  97       cnt = 0;
  98       do
  99         {
 100           if (from_tbl[idx + cnt] != winbuf[cnt])
 101             /* Does not match.  */
 102             break;
 103           ++cnt;
 104         }
 105       while (from_tbl[idx + cnt] != L'\0' && winbuf + cnt < winbufend);
 106
 107       if (cnt > 0 && from_tbl[idx + cnt] == L'\0')
 108         {
 109           /* Found a matching input sequence.  Now try to convert the
 110              possible replacements.  */
 111           uint32_t idx2 = to_idx[med];
 112
 113           do
 114             {
 115               /* Determine length of replacement.  */
 116               uint_fast32_t len = 0;
 117               int res;
 118               const unsigned char *toinptr;
 119               unsigned char *outptr;
 120
 121               while (to_tbl[idx2 + len] != L'\0')
 122                 ++len;
 123
 124               /* Try this input text.  */
 125               toinptr = (const unsigned char *) &to_tbl[idx2];
 126               outptr = *outbufstart;
 127               res = DL_CALL_FCT (fct,
 128                                  (step, step_data, &toinptr,
 129                                   (const unsigned char *) &to_tbl[idx2 + len],
 130                                   &outptr, NULL, 0, 0));
 131               if (res != __GCONV_ILLEGAL_INPUT)
 132                 {
 133                   /* If the conversion succeeds we have to increment the
 134                      input buffer.  */
 135                   if (res == __GCONV_EMPTY_INPUT)
 136                     {
 137                       *inbufp += cnt * sizeof (uint32_t);
 138                       ++*irreversible;
 139                       res = __GCONV_OK;
 140                     }
 141                   /* Do not increment the output pointer if we could not
 142                      store the entire output. */
 143                   if (res != __GCONV_FULL_OUTPUT)
 144                     *outbufstart = outptr;
 145
 146                   return res;
 147                 }
 148
 149               /* Next replacement.  */
 150               idx2 += len + 1;
 151             }
 152           while (to_tbl[idx2] != L'\0');
 153
 154           /* Nothing found, continue searching.  */
 155         }
 156       else if (cnt > 0)
 157         /* This means that the input buffer contents matches a prefix of
 158            an entry.  Since we cannot match it unless we get more input,
 159            we will tell the caller about it.  */
 160         return __GCONV_INCOMPLETE_INPUT;
 161
 162       if (winbuf + cnt >= winbufend || from_tbl[idx + cnt] < winbuf[cnt])
 163         low = med + 1;
 164       else
 165         high = med;
 166     }
 167
 168  no_rules:
 169   /* Maybe the character is supposed to be ignored.  */
 170   if (_NL_CURRENT_WORD (LC_CTYPE, _NL_CTYPE_TRANSLIT_IGNORE_LEN) != 0)
 171     {
 172       int n = _NL_CURRENT_WORD (LC_CTYPE, _NL_CTYPE_TRANSLIT_IGNORE_LEN);
 173       const uint32_t *ranges =
 174         (const uint32_t *) _NL_CURRENT (LC_CTYPE, _NL_CTYPE_TRANSLIT_IGNORE);
 175       const uint32_t wc = *(const uint32_t *) (*inbufp);
 176       int i;
 177
 178       /* Test whether there is enough input.  */
 179       if (winbuf + 1 > winbufend)
 180         return (winbuf == winbufend
 181                 ? __GCONV_EMPTY_INPUT : __GCONV_INCOMPLETE_INPUT);
 182
 183       for (i = 0; i < n; ranges += 3, ++i)
 184         if (ranges[0] <= wc && wc <= ranges[1]
 185             && (wc - ranges[0]) % ranges[2] == 0)
 186           {
 187             /* Matches the range.  Ignore it.  */
 188             *inbufp += 4;
 189             ++*irreversible;
 190             return __GCONV_OK;
 191           }
 192         else if (wc < ranges[0])
 193           /* There cannot be any other matching range since they are
 194              sorted.  */
 195           break;
 196     }
 197
 198   /* One last chance: use the default replacement.  */
 199   if (_NL_CURRENT_WORD (LC_CTYPE, _NL_CTYPE_TRANSLIT_DEFAULT_MISSING_LEN) != 0)
 200     {
 201       const uint32_t *default_missing = (const uint32_t *)
 202         _NL_CURRENT (LC_CTYPE, _NL_CTYPE_TRANSLIT_DEFAULT_MISSING);
 203       const unsigned char *toinptr = (const unsigned char *) default_missing;
 204       uint32_t len = _NL_CURRENT_WORD (LC_CTYPE,
 205                                        _NL_CTYPE_TRANSLIT_DEFAULT_MISSING_LEN);
 206       unsigned char *outptr;
 207       int res;
 208
 209       /* Test whether there is enough input.  */
 210       if (winbuf + 1 > winbufend)
 211         return (winbuf == winbufend
 212                 ? __GCONV_EMPTY_INPUT : __GCONV_INCOMPLETE_INPUT);
 213
 214       outptr = *outbufstart;
 215       res = DL_CALL_FCT (fct,
 216                          (step, step_data, &toinptr,
 217                           (const unsigned char *) (default_missing + len),
 218                           &outptr, NULL, 0, 0));
 219
 220       if (res != __GCONV_ILLEGAL_INPUT)
 221         {
 222           /* If the conversion succeeds we have to increment the
 223              input buffer.  */
 224           if (res == __GCONV_EMPTY_INPUT)
 225             {
 226               /* This worked but is not reversible.  */
 227               ++*irreversible;
 228               *inbufp += 4;
 229               res = __GCONV_OK;
 230             }
 231           *outbufstart = outptr;
 232
 233           return res;
 234         }
 235     }
 236
 237   /* Haven't found a match.  */
 238   return __GCONV_ILLEGAL_INPUT;
 239 }
 240
 241 int
 242 internal_function
 243 __gconv_translit_find (struct trans_struct *trans)
 244 {
 245   /* Transliteration module loading has been removed because it never
 246      worked as intended and suffered from a security vulnerability.
 247      Consequently, this function always fails.  */
 248   return 1;
 249 }