locale/findlocale.c

   1 /* Copyright (C) 1996-2014 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <assert.h>
  20 #include <locale.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <unistd.h>
  24 #ifdef _POSIX_MAPPED_FILES
  25 # include <sys/mman.h>
  26 #endif
  27
  28 #include "localeinfo.h"
  29 #include "../iconv/gconv_charset.h"
  30 #include "../iconv/gconv_int.h"
  31
  32
  33 #ifdef NL_CURRENT_INDIRECT
  34 # define DEFINE_CATEGORY(category, category_name, items, a) \
  35 extern struct __locale_data _nl_C_##category; \
  36 weak_extern (_nl_C_##category)
  37 # include "categories.def"
  38 # undef DEFINE_CATEGORY
  39
  40 /* Array indexed by category of pointers to _nl_C_CATEGORY slots.
  41    Elements are zero for categories whose data is never used.  */
  42 struct __locale_data *const _nl_C[] attribute_hidden =
  43   {
  44 # define DEFINE_CATEGORY(category, category_name, items, a) \
  45     [category] = &_nl_C_##category,
  46 # include "categories.def"
  47 # undef DEFINE_CATEGORY
  48   };
  49 #else
  50 # define _nl_C          (_nl_C_locobj.__locales)
  51 #endif
  52
  53
  54 /* For each category we keep a list of records for the locale files
  55    which are somehow addressed.  */
  56 struct loaded_l10nfile *_nl_locale_file_list[__LC_LAST];
  57
  58 const char _nl_default_locale_path[] attribute_hidden = LOCALEDIR;
  59
  60
  61 struct __locale_data *
  62 internal_function
  63 _nl_find_locale (const char *locale_path, size_t locale_path_len,
  64                  int category, const char **name)
  65 {
  66   int mask;
  67   /* Name of the locale for this category.  */
  68   char *loc_name;
  69   const char *language;
  70   const char *modifier;
  71   const char *territory;
  72   const char *codeset;
  73   const char *normalized_codeset;
  74   struct loaded_l10nfile *locale_file;
  75
  76   if ((*name)[0] == '\0')
  77     {
  78       /* The user decides which locale to use by setting environment
  79          variables.  */
  80       *name = getenv ("LC_ALL");
  81       if (*name == NULL || (*name)[0] == '\0')
  82         *name = getenv (_nl_category_names.str
  83                         + _nl_category_name_idxs[category]);
  84       if (*name == NULL || (*name)[0] == '\0')
  85         *name = getenv ("LANG");
  86     }
  87
  88   if (*name == NULL || (*name)[0] == '\0'
  89       || (__builtin_expect (__libc_enable_secure, 0)
  90           && strchr (*name, '/') != NULL))
  91     *name = (char *) _nl_C_name;
  92
  93   if (__builtin_expect (strcmp (*name, _nl_C_name), 1) == 0
  94       || __builtin_expect (strcmp (*name, _nl_POSIX_name), 1) == 0)
  95     {
  96       /* We need not load anything.  The needed data is contained in
  97          the library itself.  */
  98       *name = (char *) _nl_C_name;
  99       return _nl_C[category];
 100     }
 101
 102   /* We really have to load some data.  First we try the archive,
 103      but only if there was no LOCPATH environment variable specified.  */
 104   if (__glibc_likely (locale_path == NULL))
 105     {
 106       struct __locale_data *data
 107         = _nl_load_locale_from_archive (category, name);
 108       if (__glibc_likely (data != NULL))
 109         return data;
 110
 111       /* Nothing in the archive.  Set the default path to search below.  */
 112       locale_path = _nl_default_locale_path;
 113       locale_path_len = sizeof _nl_default_locale_path;
 114     }
 115
 116   /* We really have to load some data.  First see whether the name is
 117      an alias.  Please note that this makes it impossible to have "C"
 118      or "POSIX" as aliases.  */
 119   loc_name = (char *) _nl_expand_alias (*name);
 120   if (loc_name == NULL)
 121     /* It is no alias.  */
 122     loc_name = (char *) *name;
 123
 124   /* Make a writable copy of the locale name.  */
 125   loc_name = strdupa (loc_name);
 126
 127   /* LOCALE can consist of up to four recognized parts for the XPG syntax:
 128
 129                 language[_territory[.codeset]][@modifier]
 130
 131      Beside the first all of them are allowed to be missing.  If the
 132      full specified locale is not found, the less specific one are
 133      looked for.  The various part will be stripped off according to
 134      the following order:
 135                 (1) codeset
 136                 (2) normalized codeset
 137                 (3) territory
 138                 (4) modifier
 139    */
 140   mask = _nl_explode_name (loc_name, &language, &modifier, &territory,
 141                            &codeset, &normalized_codeset);
 142   if (mask == -1)
 143     /* Memory allocate problem.  */
 144     return NULL;
 145
 146   /* If exactly this locale was already asked for we have an entry with
 147      the complete name.  */
 148   locale_file = _nl_make_l10nflist (&_nl_locale_file_list[category],
 149                                     locale_path, locale_path_len, mask,
 150                                     language, territory, codeset,
 151                                     normalized_codeset, modifier,
 152                                     _nl_category_names.str
 153                                     + _nl_category_name_idxs[category], 0);
 154
 155   if (locale_file == NULL)
 156     {
 157       /* Find status record for addressed locale file.  We have to search
 158          through all directories in the locale path.  */
 159       locale_file = _nl_make_l10nflist (&_nl_locale_file_list[category],
 160                                         locale_path, locale_path_len, mask,
 161                                         language, territory, codeset,
 162                                         normalized_codeset, modifier,
 163                                         _nl_category_names.str
 164                                         + _nl_category_name_idxs[category], 1);
 165       if (locale_file == NULL)
 166         /* This means we are out of core.  */
 167         return NULL;
 168     }
 169
 170   /* The space for normalized_codeset is dynamically allocated.  Free it.  */
 171   if (mask & XPG_NORM_CODESET)
 172     free ((void *) normalized_codeset);
 173
 174   if (locale_file->decided == 0)
 175     _nl_load_locale (locale_file, category);
 176
 177   if (locale_file->data == NULL)
 178     {
 179       int cnt;
 180       for (cnt = 0; locale_file->successor[cnt] != NULL; ++cnt)
 181         {
 182           if (locale_file->successor[cnt]->decided == 0)
 183             _nl_load_locale (locale_file->successor[cnt], category);
 184           if (locale_file->successor[cnt]->data != NULL)
 185             break;
 186         }
 187       /* Move the entry we found (or NULL) to the first place of
 188          successors.  */
 189       locale_file->successor[0] = locale_file->successor[cnt];
 190       locale_file = locale_file->successor[cnt];
 191
 192       if (locale_file == NULL)
 193         return NULL;
 194     }
 195
 196   /* The LC_CTYPE category allows to check whether a locale is really
 197      usable.  If the locale name contains a charset name and the
 198      charset name used in the locale (present in the LC_CTYPE data) is
 199      not the same (after resolving aliases etc) we reject the locale
 200      since using it would irritate users expecting the charset named
 201      in the locale name.  */
 202   if (codeset != NULL)
 203     {
 204       /* Get the codeset information from the locale file.  */
 205       static const int codeset_idx[] =
 206         {
 207           [__LC_CTYPE] = _NL_ITEM_INDEX (CODESET),
 208           [__LC_NUMERIC] = _NL_ITEM_INDEX (_NL_NUMERIC_CODESET),
 209           [__LC_TIME] = _NL_ITEM_INDEX (_NL_TIME_CODESET),
 210           [__LC_COLLATE] = _NL_ITEM_INDEX (_NL_COLLATE_CODESET),
 211           [__LC_MONETARY] = _NL_ITEM_INDEX (_NL_MONETARY_CODESET),
 212           [__LC_MESSAGES] = _NL_ITEM_INDEX (_NL_MESSAGES_CODESET),
 213           [__LC_PAPER] = _NL_ITEM_INDEX (_NL_PAPER_CODESET),
 214           [__LC_NAME] = _NL_ITEM_INDEX (_NL_NAME_CODESET),
 215           [__LC_ADDRESS] = _NL_ITEM_INDEX (_NL_ADDRESS_CODESET),
 216           [__LC_TELEPHONE] = _NL_ITEM_INDEX (_NL_TELEPHONE_CODESET),
 217           [__LC_MEASUREMENT] = _NL_ITEM_INDEX (_NL_MEASUREMENT_CODESET),
 218           [__LC_IDENTIFICATION] = _NL_ITEM_INDEX (_NL_IDENTIFICATION_CODESET)
 219         };
 220       const struct __locale_data *data;
 221       const char *locale_codeset;
 222       char *clocale_codeset;
 223       char *ccodeset;
 224
 225       data = (const struct __locale_data *) locale_file->data;
 226       locale_codeset =
 227         (const char *) data->values[codeset_idx[category]].string;
 228       assert (locale_codeset != NULL);
 229       /* Note the length of the allocated memory: +3 for up to two slashes
 230          and the NUL byte.  */
 231       clocale_codeset = (char *) alloca (strlen (locale_codeset) + 3);
 232       strip (clocale_codeset, locale_codeset);
 233
 234       ccodeset = (char *) alloca (strlen (codeset) + 3);
 235       strip (ccodeset, codeset);
 236
 237       if (__gconv_compare_alias (upstr (ccodeset, ccodeset),
 238                                  upstr (clocale_codeset,
 239                                         clocale_codeset)) != 0)
 240         /* The codesets are not identical, don't use the locale.  */
 241         return NULL;
 242     }
 243
 244   /* Determine the locale name for which loading succeeded.  This
 245      information comes from the file name.  The form is
 246      <path>/<locale>/LC_foo.  We must extract the <locale> part.  */
 247   if (((const struct __locale_data *) locale_file->data)->name == NULL)
 248     {
 249       char *cp, *endp;
 250
 251       endp = strrchr (locale_file->filename, '/');
 252       cp = endp - 1;
 253       while (cp[-1] != '/')
 254         --cp;
 255       ((struct __locale_data *) locale_file->data)->name
 256         = __strndup (cp, endp - cp);
 257     }
 258
 259   /* Determine whether the user wants transliteration or not.  */
 260   if (modifier != NULL
 261       && __strcasecmp_l (modifier, "TRANSLIT", _nl_C_locobj_ptr) == 0)
 262     ((struct __locale_data *) locale_file->data)->use_translit = 1;
 263
 264   /* Increment the usage count.  */
 265   if (((const struct __locale_data *) locale_file->data)->usage_count
 266       < MAX_USAGE_COUNT)
 267     ++((struct __locale_data *) locale_file->data)->usage_count;
 268
 269   return (struct __locale_data *) locale_file->data;
 270 }
 271
 272
 273 /* Calling this function assumes the lock for handling global locale data
 274    is acquired.  */
 275 void
 276 internal_function
 277 _nl_remove_locale (int locale, struct __locale_data *data)
 278 {
 279   if (--data->usage_count == 0)
 280     {
 281       if (data->alloc != ld_archive)
 282         {
 283           /* First search the entry in the list of loaded files.  */
 284           struct loaded_l10nfile *ptr = _nl_locale_file_list[locale];
 285
 286           /* Search for the entry.  It must be in the list.  Otherwise it
 287              is a bug and we crash badly.  */
 288           while ((struct __locale_data *) ptr->data != data)
 289             ptr = ptr->next;
 290
 291           /* Mark the data as not available anymore.  So when the data has
 292              to be used again it is reloaded.  */
 293           ptr->decided = 0;
 294           ptr->data = NULL;
 295         }
 296
 297       /* This does the real work.  */
 298       _nl_unload_locale (data);
 299     }
 300 }