locale/findlocale.c

   1 /* Copyright (C) 1996, 1997, 1998, 1999 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 #include <sys/mman.h>
  25
  26 #include "localeinfo.h"
  27
  28
  29 /* Constant data defined in setlocale.c.  */
  30 extern struct locale_data *const _nl_C[];
  31
  32
  33 /* For each category we keep a list of records for the locale files
  34    which are somehow addressed.  */
  35 static struct loaded_l10nfile *locale_file_list[LC_ALL];
  36
  37
  38 struct locale_data *
  39 _nl_find_locale (const char *locale_path, size_t locale_path_len,
  40                  int category, const char **name)
  41 {
  42   int mask;
  43   /* Name of the locale for this category.  */
  44   char *loc_name;
  45   const char *language;
  46   const char *modifier;
  47   const char *territory;
  48   const char *codeset;
  49   const char *normalized_codeset;
  50   const char *special;
  51   const char *sponsor;
  52   const char *revision;
  53   struct loaded_l10nfile *locale_file;
  54
  55   if ((*name)[0] == '\0'
  56       /* In SUID binaries we must not allow people to access files
  57          outside the dedicated locale directories.  */
  58       || (__libc_enable_secure
  59           && memchr (*name, '/', _nl_find_language (*name) - *name) != NULL))
  60     {
  61       /* The user decides which locale to use by setting environment
  62          variables.  */
  63       *name = getenv ("LC_ALL");
  64       if (*name == NULL || (*name)[0] == '\0')
  65         *name = getenv (_nl_category_names[category]);
  66       if (*name == NULL || (*name)[0] == '\0')
  67         *name = getenv ("LANG");
  68       if (*name == NULL || (*name)[0] == '\0')
  69         *name = (char *) _nl_C_name;
  70     }
  71
  72   if (strcmp (*name, _nl_C_name) == 0 || strcmp (*name, _nl_POSIX_name) == 0)
  73     {
  74       /* We need not load anything.  The needed data is contained in
  75          the library itself.  */
  76       *name = (char *) _nl_C_name;
  77       return _nl_C[category];
  78     }
  79
  80   /* We really have to load some data.  First see whether the name is
  81      an alias.  Please note that this makes it impossible to have "C"
  82      or "POSIX" as aliases.  */
  83   loc_name = (char *) _nl_expand_alias (*name);
  84   if (loc_name == NULL)
  85     /* It is no alias.  */
  86     loc_name = (char *) *name;
  87
  88   /* Make a writable copy of the locale name.  */
  89   loc_name = __strdup (loc_name);
  90
  91   /* LOCALE can consist of up to four recognized parts for the XPG syntax:
  92
  93                 language[_territory[.codeset]][@modifier]
  94
  95      and six parts for the CEN syntax:
  96
  97         language[_territory][+audience][+special][,[sponsor][_revision]]
  98
  99      Beside the first all of them are allowed to be missing.  If the
 100      full specified locale is not found, the less specific one are
 101      looked for.  The various part will be stripped of according to
 102      the following order:
 103                 (1) revision
 104                 (2) sponsor
 105                 (3) special
 106                 (4) codeset
 107                 (5) normalized codeset
 108                 (6) territory
 109                 (7) audience/modifier
 110    */
 111   mask = _nl_explode_name (loc_name, &language, &modifier, &territory,
 112                            &codeset, &normalized_codeset, &special,
 113                            &sponsor, &revision);
 114
 115   /* If exactly this locale was already asked for we have an entry with
 116      the complete name.  */
 117   locale_file = _nl_make_l10nflist (&locale_file_list[category],
 118                                     locale_path, locale_path_len, mask,
 119                                     language, territory, codeset,
 120                                     normalized_codeset, modifier, special,
 121                                     sponsor, revision,
 122                                     _nl_category_names[category], 0);
 123
 124   if (locale_file == NULL)
 125     {
 126       /* Find status record for addressed locale file.  We have to search
 127          through all directories in the locale path.  */
 128       locale_file = _nl_make_l10nflist (&locale_file_list[category],
 129                                         locale_path, locale_path_len, mask,
 130                                         language, territory, codeset,
 131                                         normalized_codeset, modifier, special,
 132                                         sponsor, revision,
 133                                         _nl_category_names[category], 1);
 134       if (locale_file == NULL)
 135         /* This means we are out of core.  */
 136         return NULL;
 137     }
 138   else
 139     /* If the addressed locale is already available it should be
 140        freed.  If we would not do this switching back and force
 141        between two locales would slowly eat up all memory.  */
 142     free ((void *) loc_name);
 143
 144   /* The space for normalized_codeset is dynamically allocated.  Free it.  */
 145   if (mask & XPG_NORM_CODESET)
 146     free ((void *) normalized_codeset);
 147
 148   if (locale_file->decided == 0)
 149     _nl_load_locale (locale_file, category);
 150
 151   if (locale_file->data == NULL)
 152     {
 153       int cnt;
 154       for (cnt = 0; locale_file->successor[cnt] != NULL; ++cnt)
 155         {
 156           if (locale_file->successor[cnt]->decided == 0)
 157             _nl_load_locale (locale_file->successor[cnt], category);
 158           if (locale_file->successor[cnt]->data != NULL)
 159             break;
 160         }
 161       /* Move the entry we found (or NULL) to the first place of
 162          successors.  */
 163       locale_file->successor[0] = locale_file->successor[cnt];
 164       locale_file = locale_file->successor[cnt];
 165     }
 166
 167   if (locale_file == NULL)
 168     return NULL;
 169
 170   /* Determine the locale name for which loading succeeded.  This
 171      information comes from the file name.  The form is
 172      <path>/<locale>/LC_foo.  We must extract the <locale> part.  */
 173   if (((struct locale_data *) locale_file->data)->name == NULL)
 174     {
 175       char *cp, *endp;
 176
 177       endp = strrchr (locale_file->filename, '/');
 178       cp = endp - 1;
 179       while (cp[-1] != '/')
 180         --cp;
 181       ((struct locale_data *) locale_file->data)->name = __strndup (cp,
 182                                                                     endp - cp);
 183     }
 184   *name = (char *) ((struct locale_data *) locale_file->data)->name;
 185
 186   /* Increment the usage count.  */
 187   if (((struct locale_data *) locale_file->data)->usage_count
 188       < MAX_USAGE_COUNT)
 189     ++((struct locale_data *) locale_file->data)->usage_count;
 190
 191   return (struct locale_data *) locale_file->data;
 192 }
 193
 194
 195 /* Calling this function assumes the lock for handling global locale data
 196    is acquired.  */
 197 void
 198 _nl_remove_locale (int locale, struct locale_data *data)
 199 {
 200   if (--data->usage_count == 0)
 201     {
 202       /* First search the entry in the list of loaded files.  */
 203       struct loaded_l10nfile *ptr = locale_file_list[locale];
 204
 205       /* Search for the entry.  It must be in the list.  Otherwise it
 206          is a bug and we crash badly.  */
 207       while ((struct locale_data *) ptr->data != data)
 208         ptr = ptr->next;
 209
 210       /* Mark the data as not available anymore.  So when the data has
 211          to be used again it is reloaded.  */
 212       ptr->decided = 0;
 213       ptr->data = NULL;
 214
 215       /* Free the name.  */
 216       free ((char *) data->name);
 217
 218       /* Really delete the data.  First delete the real data.  */
 219       if (data->mmaped)
 220         {
 221           /* Try to unmap the area.  If this fails we mark the area as
 222              permanent.  */
 223           if (__munmap ((caddr_t) data->filedata, data->filesize) != 0)
 224             {
 225               data->usage_count = UNDELETABLE;
 226               return;
 227             }
 228         }
 229       else
 230         /* The memory was malloced.  */
 231         free ((void *) data->filedata);
 232
 233       /* Now free the structure itself.  */
 234       free (data);
 235     }
 236 }
 237
 238 static void __attribute__ ((unused))
 239 free_mem (void)
 240 {
 241   int category;
 242
 243   for (category = 0; category < __LC_LAST; ++category)
 244     if (category != LC_ALL)
 245       {
 246         struct loaded_l10nfile *runp = locale_file_list[category];
 247
 248         while (runp != NULL)
 249           {
 250             struct loaded_l10nfile *here = runp;
 251             struct locale_data *data = (struct locale_data *) runp->data;
 252
 253             if (data != NULL && data->usage_count != UNDELETABLE)
 254               _nl_unload_locale (data);
 255             runp = runp->next;
 256             free (here);
 257           }
 258       }
 259 }
 260 text_set_element (__libc_subfreeres, free_mem);