locale/findlocale.c

   1 /* Copyright (C) 1996, 1997, 1998, 1999, 2000 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 Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    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    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  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
  30
  31 /* Constant data defined in setlocale.c.  */
  32 extern struct locale_data *const _nl_C[];
  33
  34
  35 /* For each category we keep a list of records for the locale files
  36    which are somehow addressed.  */
  37 static struct loaded_l10nfile *locale_file_list[LC_ALL];
  38
  39
  40 struct locale_data *
  41 _nl_find_locale (const char *locale_path, size_t locale_path_len,
  42                  int category, const char **name)
  43 {
  44   int mask;
  45   /* Name of the locale for this category.  */
  46   char *loc_name;
  47   const char *language;
  48   const char *modifier;
  49   const char *territory;
  50   const char *codeset;
  51   const char *normalized_codeset;
  52   const char *special;
  53   const char *sponsor;
  54   const char *revision;
  55   struct loaded_l10nfile *locale_file;
  56
  57   if ((*name)[0] == '\0'
  58       /* In SUID binaries we must not allow people to access files
  59          outside the dedicated locale directories.  */
  60       || (__builtin_expect (__libc_enable_secure, 0)
  61           && memchr (*name, '/', _nl_find_language (*name) - *name) != NULL))
  62     {
  63       /* The user decides which locale to use by setting environment
  64          variables.  */
  65       *name = getenv ("LC_ALL");
  66       if (*name == NULL || (*name)[0] == '\0')
  67         *name = getenv (_nl_category_names[category]);
  68       if (*name == NULL || (*name)[0] == '\0')
  69         *name = getenv ("LANG");
  70       if (*name == NULL || (*name)[0] == '\0')
  71         *name = (char *) _nl_C_name;
  72     }
  73
  74   if (__builtin_expect (strcmp (*name, _nl_C_name), 1) == 0
  75       || __builtin_expect (strcmp (*name, _nl_POSIX_name), 1) == 0)
  76     {
  77       /* We need not load anything.  The needed data is contained in
  78          the library itself.  */
  79       *name = (char *) _nl_C_name;
  80       return _nl_C[category];
  81     }
  82
  83   /* We really have to load some data.  First see whether the name is
  84      an alias.  Please note that this makes it impossible to have "C"
  85      or "POSIX" as aliases.  */
  86   loc_name = (char *) _nl_expand_alias (*name);
  87   if (loc_name == NULL)
  88     /* It is no alias.  */
  89     loc_name = (char *) *name;
  90
  91   /* Make a writable copy of the locale name.  */
  92   loc_name = strdupa (loc_name);
  93
  94   /* LOCALE can consist of up to four recognized parts for the XPG syntax:
  95
  96                 language[_territory[.codeset]][@modifier]
  97
  98      and six parts for the CEN syntax:
  99
 100         language[_territory][+audience][+special][,[sponsor][_revision]]
 101
 102      Beside the first all of them are allowed to be missing.  If the
 103      full specified locale is not found, the less specific one are
 104      looked for.  The various part will be stripped of according to
 105      the following order:
 106                 (1) revision
 107                 (2) sponsor
 108                 (3) special
 109                 (4) codeset
 110                 (5) normalized codeset
 111                 (6) territory
 112                 (7) audience/modifier
 113    */
 114   mask = _nl_explode_name (loc_name, &language, &modifier, &territory,
 115                            &codeset, &normalized_codeset, &special,
 116                            &sponsor, &revision);
 117
 118   /* If exactly this locale was already asked for we have an entry with
 119      the complete name.  */
 120   locale_file = _nl_make_l10nflist (&locale_file_list[category],
 121                                     locale_path, locale_path_len, mask,
 122                                     language, territory, codeset,
 123                                     normalized_codeset, modifier, special,
 124                                     sponsor, revision,
 125                                     _nl_category_names[category], NULL, 0);
 126
 127   if (locale_file == NULL)
 128     {
 129       /* Find status record for addressed locale file.  We have to search
 130          through all directories in the locale path.  */
 131       locale_file = _nl_make_l10nflist (&locale_file_list[category],
 132                                         locale_path, locale_path_len, mask,
 133                                         language, territory, codeset,
 134                                         normalized_codeset, modifier, special,
 135                                         sponsor, revision,
 136                                         _nl_category_names[category], NULL, 1);
 137       if (locale_file == NULL)
 138         /* This means we are out of core.  */
 139         return NULL;
 140     }
 141
 142   /* The space for normalized_codeset is dynamically allocated.  Free it.  */
 143   if (mask & XPG_NORM_CODESET)
 144     free ((void *) normalized_codeset);
 145
 146   if (locale_file->decided == 0)
 147     _nl_load_locale (locale_file, category);
 148
 149   if (locale_file->data == NULL)
 150     {
 151       int cnt;
 152       for (cnt = 0; locale_file->successor[cnt] != NULL; ++cnt)
 153         {
 154           if (locale_file->successor[cnt]->decided == 0)
 155             _nl_load_locale (locale_file->successor[cnt], category);
 156           if (locale_file->successor[cnt]->data != NULL)
 157             break;
 158         }
 159       /* Move the entry we found (or NULL) to the first place of
 160          successors.  */
 161       locale_file->successor[0] = locale_file->successor[cnt];
 162       locale_file = locale_file->successor[cnt];
 163
 164       if (locale_file == NULL)
 165         return NULL;
 166     }
 167
 168   /* Determine the locale name for which loading succeeded.  This
 169      information comes from the file name.  The form is
 170      <path>/<locale>/LC_foo.  We must extract the <locale> part.  */
 171   if (((struct locale_data *) locale_file->data)->name == NULL)
 172     {
 173       char *cp, *endp;
 174
 175       endp = strrchr (locale_file->filename, '/');
 176       cp = endp - 1;
 177       while (cp[-1] != '/')
 178         --cp;
 179       ((struct locale_data *) locale_file->data)->name = __strndup (cp,
 180                                                                     endp - cp);
 181     }
 182   *name = (char *) ((struct locale_data *) locale_file->data)->name;
 183
 184   /* Determine whether the user wants transliteration or not.  */
 185   if ((modifier != NULL && __strcasecmp (modifier, "TRANSLIT") == 0)
 186       || (special != NULL && __strcasecmp (special, "TRANSLIT") == 0))
 187     ((struct locale_data *) locale_file->data)->use_translit = 1;
 188
 189   /* Increment the usage count.  */
 190   if (((struct locale_data *) locale_file->data)->usage_count
 191       < MAX_USAGE_COUNT)
 192     ++((struct locale_data *) locale_file->data)->usage_count;
 193
 194   return (struct locale_data *) locale_file->data;
 195 }
 196
 197
 198 /* Calling this function assumes the lock for handling global locale data
 199    is acquired.  */
 200 void
 201 _nl_remove_locale (int locale, struct locale_data *data)
 202 {
 203   if (--data->usage_count == 0)
 204     {
 205       /* First search the entry in the list of loaded files.  */
 206       struct loaded_l10nfile *ptr = locale_file_list[locale];
 207
 208       /* Search for the entry.  It must be in the list.  Otherwise it
 209          is a bug and we crash badly.  */
 210       while ((struct locale_data *) ptr->data != data)
 211         ptr = ptr->next;
 212
 213       /* Mark the data as not available anymore.  So when the data has
 214          to be used again it is reloaded.  */
 215       ptr->decided = 0;
 216       ptr->data = NULL;
 217
 218       /* Free the name.  */
 219       free ((char *) data->name);
 220
 221 #ifdef _POSIX_MAPPED_FILES
 222       /* Really delete the data.  First delete the real data.  */
 223       if (__builtin_expect (data->mmaped, 1))
 224         {
 225           /* Try to unmap the area.  If this fails we mark the area as
 226              permanent.  */
 227           if (__munmap ((caddr_t) data->filedata, data->filesize) != 0)
 228             {
 229               data->usage_count = UNDELETABLE;
 230               return;
 231             }
 232         }
 233       else
 234 #endif  /* _POSIX_MAPPED_FILES */
 235         /* The memory was malloced.  */
 236         free ((void *) data->filedata);
 237
 238       /* Now free the structure itself.  */
 239       free (data);
 240     }
 241 }
 242
 243 static void __attribute__ ((unused))
 244 free_mem (void)
 245 {
 246   int category;
 247
 248   for (category = 0; category < __LC_LAST; ++category)
 249     if (category != LC_ALL)
 250       {
 251         struct loaded_l10nfile *runp = locale_file_list[category];
 252
 253         while (runp != NULL)
 254           {
 255             struct loaded_l10nfile *here = runp;
 256             struct locale_data *data = (struct locale_data *) runp->data;
 257
 258             if (data != NULL && data->usage_count != UNDELETABLE)
 259               _nl_unload_locale (data);
 260             runp = runp->next;
 261             free (here);
 262           }
 263       }
 264 }
 265 text_set_element (__libc_subfreeres, free_mem);